Note: Descriptions are shown in the official language in which they were submitted.
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Process for producing laundry detergent and cleaning
product tablets
Field of the Invention
The present invention relates to a new process for
producing single-phase and multiphase laundry detergent
and cleaning product tablets.
Background of the Invention
Laundry detergent and cleaning product tablets have
been widely described in the prior art and are enjoying
increasing popularity among users owing to the ease of
dosing. Tableted cleaning products have a number of
advantages over their powder-form counterparts: They
are easier to dose and to handle, and have storage and
transport advantages owing to their compact structure.
Consequently, there exists an extremely broad prior art
relating to laundry detergent and cleaning product
tablets, which is also reflected in an extensive patent
literature. At an early stage, the developers of
products in tablet form hit upon the idea of using
tablet regions of different composition to release
certain ingredients only under defined conditions in
the course of washing or cleaning in order to improve
the end result. Tablets which have become established
in this context are not only the core/sheath tablets
and ring/core tablets, which are sufficiently well
known from pharmacy, but also, in particular,
multilayer tablets, which are nowadays available for
many areas of washing and cleaning or of hygiene.
Visual differentiation of the products is also becoming
increasingly important, so that single-phase and
single-color tablets in the field of washing and
cleaning have been largely displaced by multiphase
tablets. Common current market forms include two-layer
tablets having a white and a colored phase or having
two differently colored layers. In addition, there
exist inlay tablets, ring-core tablets, laminated
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tablets, etc., whose importance at present is fairly
minor.
The preparation of said tablets always comprises at
least one tableting step, in which a particulate premix
is converted under pressure into a compact tablet. In
the case of the abovementioned two-layer tablets,
sheath/core tablets, etc., different premixes are
pressed onto and/or into one another. In addition,
there exist proposals to produce tablets by means of
conventional compression technology and to fill
cavities in these tablets with melts or the like in
order to obtain composition tablets comprising com-
pressed and noncompressed fractions.
A further process utilized to produce compact laundry
detergent and cleaning product pieces is that of
extrusion. Here, a premix is plasticated under high
pressures and discharged through perforated molds, fol-
lowed by shaping by means of cutting, and by optional
aftertreatment. In contrast to tableting, where the
particle bed is, so to speak, "sintered", and where the
tablets still possess a hollow volume, the high
pressures of 100 bar or more during extrusion lead to
very compact particles or pieces whose internal hollow
volume is greatly reduced.
Multilayer cleaning product tablets for machine dish-
washing are described, for example, in European Patent
Application EP 224 128 (Henkel KGaA). The two layers
have solubility differences, which leads to advan-
tageous performance properties.
Multiphase cleaning tablets for the WC are described,
for example, in EP 055 100 (Jeyes Group). This document
discloses toilet cleaning blocks comprising a shaped
body, consisting of a slow-dissolving cleaning product
composition, into which a bleach tablet has been
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embedded. At the same time, this document discloses the
very wide variety of design forms of multiphase
tablets. In accordance with the teaching of this
document, the tablets are produced either by inserting
a compressed bleach tablet into a mold and casting the
cleaning product composition around this tablet, or by
casting part of the cleaning product composition into
the mold, followed by the insertion of the compressed
bleach tablet and, possibly, subsequent overcasting
with further cleaning product composition.
In addition, EP 481 547 (Unilever) describes multiphase
cleaning product tablets which are intended for use for
machine dishwashing. These tablets have the form of
core/sheath tablets and are produced by stepwise com-
pression of the constituents: first of all, a bleach
composition is compressed to form a tablet, which is
placed in a die which is half-filled with a polymer
composition, this die then being filled up with further
polymer composition and compressed to form a bleach
tablet provided with a polymer sheath. The process is
subsequently repeated with an alkaline cleaning product
composition, so as to give a three-phase tablet.
Another route to producing visually differentiated
laundry detergent and cleaning product tablets is
described in International Patent Applications W099/-
06522, W099/27063 and W099/27067 (Procter & Gamble).
According to the teaching of these documents, a tablet
is prepared which has a cavity that is filled with a
solidifying melt. Alternatively, a powder is introduced
and is fixed in the cavity by means of a coating layer.
A common feature of all three applications is that the
region filling out the cavity should not be compressed,
since the intention is in this way to protect
"pressure-sensitive" ingredients.
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Both tableting and extrusion lead to a high pressure
load on the premixes for processing, which makes it
difficult or impossible to incorporate pressure-sensi-
tive ingredients. Also, the production of tablets with
three or more phases is no longer possible without
problems using either process, since the technical
expense increases greatly as the number of phases goes
up.
The extrusion or coextrusion of two or more premixes is
virtually impossible when there are large differences
in the proportion of the individual phases. The
conventional tableting of multilayer tablets likewise
reaches its limits in the field of laundry detergent
and cleaning product tablets if one layer is intended
to comprise only a small fraction of the total tablet.
Below a certain layer thickness, compression of a layer
adhering to the remainder of the tablet becomes
increasingly difficult.
Summary of the Invention
It is an object of the present invention, then, to
provide a production process for single-phase and
multiphase tablets in which even pressure-sensitive
ingredients may be accommodated in delimited regions,
without any restrictions on the size of the delimited
region in relation to the total tablet. At the same
time, moreover, firstly there ought to be visual
differentiation from conventional two-layer tablets and
secondly the production of the tablets ought to
function reliably without great technical effort even
in mass production without the tablets suffering from
stability drawbacks and without the fear of dosing
inaccuracies.
In particular, it is an object of the present invention
to provide a new production process for laundry
detergent and cleaning product tablets which is
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superior to the existing tableting and extrusion
technology in respect of the protection of the ingredi-
ents against thermal loads, pressure and shearing,
which is less complex in terms of the apparatus and
5 more favorable in terms of process economics, and which
permits higher throughputs. In addition, the process
should be able to be used without great effort for the
production of tablets with three or more phases as
well.
It has now been found that the low-pressure strand
processing of deformable, curable masses is suitable
for producing laundry detergent and cleaning product
tablets, and does so while meeting the abovementioned
profiles of requirements.
The invention provides a process for producing laundry
detergent and cleaning product tablets, which involves
preparing (a) deformable mass(es), supplying said
masses) with a pressure below 40 bar to emergence
apertures, cutting the emerging material strands to
tablet dimensions, and hardening them.
Preferably, the deformable masses which harden after
deformation are supplied to the emergence apertures at
even lower pressures, in order to protect pressure-
sensitive ingredients. Preferred processes are those
wherein the deformable masses) is (are) supplied to
the emergence apertures with a pressure below 35 bar,
preferably below 30 bar, with particular preference
below 20 bar, and in particular below 10 bar.
Depending on the final processing of the deformable
masses (see below) and on the configuration of the pro-
cessing machines, it is also possible to realize even
lower pressures, or a procedure without pressure is
possible. Processes wherein the deformable masses) is
(are) supplied to the emergence apertures with a
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pressure below 8.5 bar, preferably below 7.5 bar, with
particular preference below 6.5 bar, and in particular
below 5 bar, are a further important embodiment of the
present invention.
Detailed Description of the Invention
Below, technical apparatus parameters and technical
features of the process of the invention will be
described, before the ingredients and physical para-
meters of the masses for processing are dealt with.
The process of the invention provides for the
processing of deformable masses which harden or
solidify after shaping to give compact tablets. In
contrast to the extrusion of laundry detergents and
cleaning products, where solid, free-flowing premixes
are plasticated and shaped by high pressures, the
process of the invention is operated at low pressures
and starts from deformable masses. These deformable
masses are not particulate, but are paste-like or
plastic and harden after shaping.
A procedure preferred in the context of the present
invention for supplying the deformable masses to the
emergence apertures comprises drawing them in between
two rolls which have opposite directions of rotation.
By this means, the mass between the rolls is conveyed
under low pressure, depending on the width of the nip
between the rolls and on the roll speed, in the direc-
tion of the emergence apertures. Depending on the
number of roll pairs and emergence apertures, and on
the design of these apertures, this results in single-
phase or multiphase material strands which may have
different shapes and/or colors. These material strands
are cut into sections of predetermined length, and the
individual strand sections are hardened to give the
finished laundry detergent and cleaning product tablet.
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Single-phase tablets are advantageously produced by
supplying a deformable mass with one roll pair to an
emergence aperture. Preferred processes are those
wherein a deformable mass is drawn in between two
rolls, discharged as a material strand from emergence
apertures, cut to the desired tablet dimension, and
hardened.
Apparatus suitable for the preferred process is obtain-
able, for example, from the company Hosokawa Bepex GmbH
under the name "Drehstab-Walzenpresse DP" [rotary-rod
roll press DP]. The emergence apertures of such
apparatus may, for example, be circular, triangular,
square, rectangular, heart-shaped, crescent-shaped,
etc., in design. The first-mentioned apertures then
give rise to cylindrical, prismatic, cuboid, tetragonal
or orthorhombic tablets. The drawings, in Figures 27
and also 29 to 42, show by way of example some possible
designs for emergence apertures.
It is likewise possible to rotate the material strands
following emergence from the apertures in the shapable
state before they are cut to the desired tablet
dimensions. This produces tablets having irregular,
spiral side faces, which offer particular visual
attractiveness.
Two-phase tablets may be produced correspondingly using
two roll pairs. Preferred processes for this purpose
are those wherein two deformable masses of different
composition are drawn in between two roll pairs and
discharged as filled, hollow or multi-ply material
strands from emergence apertures, cut to the desired
tablet dimension, and hardened. It is of course also
possible to process two masses of identical composition
in a similar way. In this case this is done not for
separation of active substances or to achieve specific
washing and cleaning effects, but instead for visual
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attractiveness. Apparatus suitable for such processes
of the invention is again available from the company
Hosokawa Bepex GmbH under the name "Doppel-Drehstab-
Walzenpresse DDP" [double rotary-rod roll press DDP].
The emergence apertures of such apparatus may be
arranged alongside or inside one another, producing
multi-ply or multiphase tablets. Figures 15 to 26 and
28 show by way of example some cross sections of
emergence apertures for different masses. In Figures
15, 16, 17, 19, 21, 23, and 25, there result strands
and tablets in which one part, apart from the cut
faces, is completely enclosed by the other part. The
other figures mentioned show strands or tablets,
respectively, in which one part is embedded on or only
partly in the other part. Here again, rotation of the
material strands prior to cutting to length is possible
in order to achieve particular visual effects.
The process of the invention may also be utilized with-
out problems to produce three-phase tablets. Completely
in analogy to the remarks made so far, such processes
of the invention are implemented by drawing in three
plastically deformable masses of different composition
between three roll pairs and discharging them as
singly, doubly or triply filled, hollow, two- or three-
ply material strands from emergence apertures, cutting
them to the desired tablet dimension, and hardening
them.
Here again, it is of course possible to process two or
even three masses of identical composition in a similar
manner. This is then used in turn not (only) to
separate active substances or to achieve particular
washing and cleaning effects, but instead for visual
attractiveness. Apparatus suitable for the production
of three-phase tablets, as well, is available from the
company Hosokawa Bepex GmbH under the name "Dreifach-
Drehstab-Walzenpresse DP/3" [triple rotary-rod roll
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press DP/3]. The emergence apertures of such apparatus
may be arranged alongside or inside one another,
producing multi-ply or multiphase tablets. Figures 1 to
14 show by way of example some cross sections of
emergence apertures for different masses. Here again,
in turn, the material strands may be rotated prior to
cutting to length in order to obtain particular visual
effects.
The possibilities for discharging a plurality of mater-
ial strands onto, alongside, over, under or into one
another from the apparatus are unlimited, so that even
tablets with four or more phases may be produced in a
simple manner. Since the apparatus and the associated
die systems are of simple and robust construction, a
changeover of product shape, and adaptation to differ-
ent market requirements, are possible rapidly and
without complication. Changes in shape on the resultant
tablets may also be brought about without problems by
means of the appropriate treatment of the material
strands prior to cutting. If, for example, in accord-
ance with Figure 1, three material strands are
discharged onto one another from three emergence aper-
tures having a circular cross section, then, after
cutting to length, tablets are produced which have the
form of three stacked cylinders. By simple rotation of
the three material strands about their longitudinal
axis prior to cutting to length, laundry detergent and
cleaning product tablets are obtained which have the
form of segments turned in toward one another and
suggest rigging or braids. The flexibility of the
process of the invention in terms of the changeover of
shapes and esthetic design is therefore far greater
than that of the processes known to date.
In the production of multiphase tablets, the ratio of
these phases to one another may be chosen freely; from
esthetic standpoints, it may be advantageous if one
CA 02313356 2000-07-04
phase accounts for at least 1/100, preferably at least
1/20 and in particular at least 1/10 of the volume or
the weight of the other phase (s) . In preferred process
end products, the weight ratio of the masses to one
5 another is in the range from 1:1 to 1:100, preferably
from 1:2 to 1:75, and in particular from 1:2.5 to 1:30
(two-phase tablets) or, respectively, in the range from
1:1:1 to 1:100:100, preferably from 1:1:2 to 1:75:75,
and in particular from 1:1:2.5 to 1:30:30 (three-phase
10 tablets). The ratio of the surface areas of the
individual tablet phases is preferably within similar
ranges.
Depending on the final processing of the deformable
masses (see below), i.e., depending on the ingredients
and the physical parameters of the masses for process-
ing, it is possible to achieve throughputs of differing
levels, which further depend on the size of the
emergence apertures. It is preferred in this context to
keep within certain emergence rates for the material
strands. In preferred processes the material strands
are discharged from the emergence apertures at a rate
of from 0.2 m/min to 30 m/min, preferably from
0.25 m/min to 20 m/min, with particular preference from
0.5 m/min to 15 m/min, and in particular from 1 m/min
to 10 m/min.
In principle, the process of the invention is not
limited as regards the shape and size of the emergence
apertures. In view of the products to be manufactured
and their size and mass, which in the case of such
products is usually in the range from 5 to 500 g,
preferably from 10 to 250 g, with particular preference
from 15 to 100 g, and in particular between 20 and
50 g, preference is given to processes wherein the
emergence apertures have aperture areas of from 50 mm2
to 2500 mm2, preferably from 100 mm2 to 2000 mm2, with
particular preference from 200 mm2 to 1500 mmz, and in
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particular from 300 mm2 to 1000 mm2, with especial
preference from 350 mm2 to 750 mm2.
However, it is possible to drop below these values for
individual emergence apertures, for example, if the
purpose of one emergence aperture is to place a thin
"tube" over another strand, thereby, so to speak,
coating the latter. Strand cross sections of this kind
are sketched, for example, in Figures 15, 17, 21 and
23, it being entirely possible in each case for the
external part to be thinner. In that case, the finished
tablet contains strands which apart from the end faces
(cut faces) are coated, from which effects may be
achieved in terms of delayed or accelerated release.
With the exception of such coated strands, however,
preference is given to processes wherein the thickness
of at least one of the material strands emerging from
the emergence apertures is at least 5 mm, preferably at
least 7.5 mm, and in particular at least 10 mm.
The cutting to length of the material strands emerging
from the emergence apertures may take place in accord-
ance with the known processes of the prior art, for
example, by means of rotating blades, lowerable cutters
or wires, etc. The mass of the finished tablets is
guided on the one hand by the size of the emergence
apertures and on the other hand by the length of the
cuts. Where conventional laundry detergent and cleaning
product tablets are to be provided for customary
utilities such as, for example, laundry detergent
tablets or machine dishwashing detergent tablets,
preference is given to processes wherein the material
strands emerging from the emergence apertures are cut
to a length of from 10 to 100 mm, preferably from 12.5
to 75 mm, with particular preference from 15 to 60 mm,
and in particular from 20 to 50 mm.
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Depending on the composition or on the desired end use,
however, it is also possible to go above or below the
abovementioned limits. Thus it is possible, for
example, to process masses which are relatively poorly
soluble after hardening and to cut them to lengths of
from 100 to 1000 mm, preferably from 120 to 750 mm, and
in particular from 150 to 500 mm. The hardened "rods"
obtained in this way may then be accommodated in wash-
ing machines or dishwashers as depot blocks, where in
each washing cycle a defined portion of the block is
dissolved while the remainder remains in the machine or
its dosing system for the next cleaning cycle.
After cutting to the desired tablet dimensions, the
strand sections are hardened. Hardening is carried out
differently (see below) depending on the composition of
the masses, so that hardening may if desired be
assisted or accelerated by means of appropriate
measures. It is possible, for example, to initiate or
accelerate reactive hardening by spraying activators
onto the surface. In the case of radiation-hardening
masses, exposure to radioactive rays may also be
utilized, as can W radiation for UV-active masses. In
preferred processes, hardening takes place by means of
internal and external drying and/or cooling, so that
preferred processes are those wherein the hardening of
the material strands, cut to tablet dimensions, is
assisted by superficial drying and/or cooling, in
particular by blowing with cold air.
Following the description of the preferred embodiments
in terms of apparatus, there now follows a description
of the deformable and hardening masses for processing.
In this context, there is both a treatment of the
composition and physical parameters and a description
of possible hardening mechanisms.
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The hardening of the deformable masses) may take place
by different mechanisms, among which mention may be
made of time-delayed water binding, cooling below the
melting point, solvent evaporation, crystallization,
chemical reaction(s), especially polymerization, and
changes in the rheological properties as a result, for
example, of altered shearing of the mass(es), as the
most important hardening mechanisms, in addition to the
already mentioned radiation hardening by means of W,
alpha, beta or gamma rays.
In all cases, a deformable, preferably plastic, mass is
prepared which may be shaped without great pressures.
After shaping, hardening then takes place by means of
suitable initiation or elapse of a certain period of
time. If the masses processed have self-hardening
properties without further initiation, then this must
be taken into account in the course of processing in
order to avoid instances of hardening during shaping
and, consequently, blockages and disruptions to the
process sequences.
In processes which are preferred in the context of the
present invention, hardening of the deformable mass (es)
takes place by means of time-delayed water binding.
Time-delayed water binding in the masses processed in
accordance with the invention may in turn be realized
in different ways. Appropriate in this context, for
example, are masses which comprise hydratable, anhyd-
rous raw materials, or raw materials in low states of
hydration, which are able to undergo transition to
stable, higher hydrates, and which further comprise
water. The formation of the hydrates, which does not
take place spontaneously, then leads to the binding of
free water, which in turn leads to hardening of the
masses. Subsequently, low-pressure shaping is no longer
possible, and tablets stable to handling are produced
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which may, if desired, be treated further and/or
packaged.
Time-offset water binding may also take place, for
example, by incorporating salts containing water of
hydration, which when the temperature is increased
dissolve in their own water of crystallization, into
the masses. If there is a subsequent fall in tempera-
ture, the water of crystallization is bound again,
leading to a loss of shapeability by simple means and
to a solidification of the masses.
The swelling of natural or synthetic polymers is
another time-delayed water binding mechanism which may
be utilized in the context of the process of the
invention. In this case, mixtures of unswollen polymer
and suitable swelling agent, e.g., water, diols,
glycerol, etc., may be incorporated into the masses,
with swelling and hardening taking place after shaping.
The most important mechanism of hardening by time-
delayed water binding is the use of a combination of
water with raw materials that are anhydrous or of low
water content, which slowly hydrate. Particularly
appropriate for this purpose are substances which
contribute to the cleaning performance in the washing
or cleaning process. In the context of the process of
the invention, preferred ingredients of the deformable
masses in this context are, for example, phosphates,
carbonates, silicates, and zeolites.
It is particularly preferred if the resultant hydrate
forms have low melting points, since in this way a
combination of the hardening mechanisms by internal
drying and cooling is achieved. Preferred processes are
those wherein the deformable masses) comprises) from
10 to 95% by weight, preferably from 15 to 90% by
weight, with particular preference from 20 to 85% by
CA 02313356 2000-07-04
weight, and in particular from 25 to 80~ by weight, of
anhydrous substances which pass by hydration into a
hydrate form having a melting point below 120°C,
preferably below 100°C, and in particular below 80°C.
5
The deformable properties of the masses may be
influenced by adding plasticizers such as polyethylene
glycols, polypropylene glycols, waxes, paraffins, non-
ionic surfactants, and so on. Further details of the
10 classes of substance mentioned are given later on.
Raw materials for preferred incorporation into the
deformable masses originate from the group of the
phosphates, alkali metal phosphates being particularly
15 preferred. For the preparation of the masses, these
substances are used in anhydrous or low-water-content
form, and the desired plastic properties of the masses
are established using water and also optional plastici-
zers. After shaping, shaped and cut-to-length strands
are then hardened by hydration of the phosphates.
Alkali metal phosphates is the collective term for the
alkali metal (especially sodium and potassium) salts of
the various phosphoric acids, among which meta-
phosphoric acids (HP03)n and orthophosphoric acid H3P04,
in addition to higher-molecular-mass representatives,
may be distinguished. The phosphates combine a number
of advantages: they act as alkali carriers, prevent
limescale deposits on machine components, and lime
incrustations on fabrics, and additionally contribute
to cleaning performance.
Sodium dihydrogen phosphate, NaH2P04, exists as the
dihydrate (density 1.91 g cm-3, melting point 60°) and
as the monohydrate (density 2.04 g cm-3). Both salts are
white powders of very ready solubility in water which
lose the water of crystallization on heating and
undergo transition at 200°C to the weakly acidic
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16
diphosphate (disodium dihydrogen diphosphate, NazH2P20~)
and at the higher temperature into sodium trimeta-
phosphate (Na3P309) and Maddrell's salt (see below) .
NaH2P04 reacts acidically; it is formed if phosphoric
acid is adjusted to a pH of 4.5 using sodium hydroxide
solution and the slurry is sprayed. Potassium
dihydrogen phosphate (primary or monobasic potassium
phosphate, potassium biphosphate, PDP), KH2PO4, is a
white salt with a density of 2.33 g cm-3, has a melting
point of 253° [decomposition with formation of
potassium polyphosphate (KP03)X], and is readily soluble
in water.
Disodium hydrogen phosphate (secondary sodium
phosphate), Na2HP04, is a colorless, crystalline salt
which is very readily soluble in water. It exists in
anhydrous form and with 2 mol (density 2.066 g cm-3,
water loss at 95°) , 7 mol (density 1.68 g cm-3, melting
point 48° with loss of 5 H20), and 12 mol of water
(density 1.52 g cm-3, melting point 35° with loss of
5 H20), becomes anhydrous at 100°, and if heated more
severely undergoes transition to the diphosphate
Na4P20~. Disodium hydrogen phosphate is prepared by
neutralizing phosphoric acid with sodium carbonate
solution using phenolphthalein as indicator.
Dipotassium hydrogen phosphate (secondary or dibasic
potassium phosphate), K2HP04, is an amorphous white salt
which is readily soluble in water.
Trisodium phosphate, tertiary sodium phosphate, Na3P04,
exists as colorless crystals which as the dodecahydrate
have a density of 1.62 g cm-3 and a melting point of
73-76°C (decomposition), as the decahydrate (corres-
ponding to 19-20% P205) have a melting point of 100°C,
and in anhydrous form (corresponding to 39-40% P205)
have a density of 2.536 g cm-3. Trisodium phosphate is
readily soluble in water, with an alkaline reaction,
and is prepared by evaporative concentration of a
CA 02313356 2000-07-04
17
solution of precisely 1 mol of disodium phosphate and
1 mol of NaOH. Tripotassium phosphate (tertiary or
tribasic potassium phosphate), K3P04, is a white,
deliquescent, granular powder of density 2.56 g cm-3,
has a melting point of 1340°, and is readily soluble in
water with an alkaline reaction. It is produced, for
example, when Thomas slag is heated with charcoal and
potassium sulfate. Despite the relatively high price,
the more readily soluble and therefore highly active
potassium phosphates are frequently preferred in the
cleaning products industry over the corresponding
sodium compounds.
Tetrasodium diphosphate (sodium pyrophosphate), Na4P20~,
exists in anhydrous form (density 2.534 g cm-3, melting
point 988°, 880° also reported) and as the decahydrate
(density 1.815-1.836 g cm-3, melting point 94° with loss
of water). Both substances are colorless crystals which
dissolve in water with an alkaline reaction. Na4Pz0~ is
formed when disodium phosphate is heated at > 200° or
by reacting phosphoric acid with sodium carbonate in
stoichiometric ratio and dewatering the solution by
spraying. The decahydrate complexes heavy metal salts
and water hardeners and therefore reduces the hardness
of the water. Potassium diphosphate (potassium pyro-
phosphate), K4P20~, exists in the form of the trihydrate
and is a colorless, hygroscopic powder of density
2.33 g cm-3 which is soluble in water, the pH of the l~s
strength solution at 25° being 10.4.
Condensation of NaH2P04 or of KHzP04 gives rise to
higher-molecular-mass sodium and potassium phosphates,
among which it is possible to distinguish cyclic
representatives, the sodium and potassium metaphos-
phates, and catenated types, the sodium and potassium
polyphosphates. For the latter in particular a large
number of names are in use: fused or calcined
phosphates, Graham's salt, Kurrol's and Maddrell's
CA 02313356 2000-07-04
18
salt. All higher sodium and potassium phosphates are
referred to collectively as condensed phosphates.
The industrially important pentasodium triphosphate,
Na5P301o (sodium tripolyphosphate), is a nonhygroscopic,
white, water-soluble salt which is anhydrous or
crystallizes with 6 H20 and has the general formula
NaO- [P (O) (ONa) -O] n-Na where n - 3 . About 17 g of the
anhydrous salt dissolve in 100 g of water at room
temperature, at 60° about 20 g, at 100° around 32 g;
after heating the solution at 100°C for two hours,
about 8% orthophosphate and 15% diphosphate are
produced by hydrolysis. For the preparation of penta-
sodium triphosphate, phosphoric acid is reacted with
sodium carbonate solution or sodium hydroxide solution
in stoichiometric ratio and the solution is dewatered
by spraying. In a similar way to Graham's salt and
sodium diphosphate, pentasodium triphosphate dissolves
numerous insoluble metal compounds (including lime
soaps, etc) . Pentapotassium triphosphate, KSP3Olo
(potassium tripolyphosphate), is commercialized, for
example, in the form of a 50% strength by weight solu-
tion (> 23% P205, 25% K20) . The potassium polyphosphates
find broad application in the laundry detergents and
cleaning products industry. There also exist sodium
potassium tripolyphosphates, which may likewise be used
for the purposes of the present invention. These are
formed, for example, when sodium trimetaphosphate is
hydrolyzed with KOH:
(NaP03 ) 3 + 2 KOH -~ Na3KZP301o + H20
These phosphates can be used in accordance with the
invention in precisely the same way as sodium
tripolyphospate, potassium tripolyphosphate, or
mixtures of these two; mixtures of sodium
tripolyphosphate and sodium potassium tripolyphosphate,
or mixtures of potassium tripolyphosphate and sodium
CA 02313356 2000-07-04
19
potassium tripolyphosphate, or mixtures of sodium
tripolyphosphate and potassium tripolyphosphate and
sodium potassium tripolyphospate, may also be used in
accordance with the invention.
In preferred processes the deformable masses) com-
prise s) phosphate(s), preferably alkali metal
phosphate(s), with particular preference pentasodium or
pentapotassium triphosphate (sodium or potassium
tripolyphosphate), in amounts of from 20 to 80% by
weight, preferably from 25 to 75% by weight, and in
particular from 30 to 70% by weight, based in each case
on the mass.
Where phosphates are used as sole hydratable substances
in the masses, the amount of added water should not
exceed the water binding capacity thereof, in order to
keep the free water content of the tablets low.
Overall, processes which have been found to be
preferred for observing the abovementioned limits are
those wherein the weight ratio of phosphates) to water
in the deformable mass is less than 1:0.3, preferably
less than 1:0.25, and in particular less than 1:0.2.
Further ingredients, which may be present instead of or
in addition to phosphates in the deformable masses, are
carbonates and/or hydrogen carbonates, preference being
given to the alkali metal salts and, of these, particu-
lar preference to the potassium salts and/or sodium
salts. In preferred processes, the deformable masses)
comprises) carbonates) and/or hydrogen carbonate(s),
preferably alkali metal carbonate(s), with particular
preference sodium carbonate, in amounts of from 5 to
50% by weight, preferably from 7.5 to 40% by weight,
and in particular from 10 to 30% by weight, based in
each case on the mass.
CA 02313356 2000-07-04
Here again, the comments made above regarding the water
content of the masses are applicable. Processes which
have been found to be preferred, in particular, are
those wherein the weight ratio of carbonates) and/or
5 hydrogen carbonates) to water in the deformable mass
is less than 1:0.2, preferably less than 1:0.15, and in
particular less than 1:0.1.
Further ingredients which may be present instead of or
10 in addition to the abovementioned phosphates and/or
carbonates and/or hydrogen carbonates in the deformable
masses are silicates, preference being given to the
alkali metal silicates and, of these, particular
preference to the amorphous and/or crystalline sodium
15 and/or potassium disilicates.
Suitable crystalline, layered sodium silicates possess
the general formula NaMSiX02X+lyH2~, where M is sodium or
hydrogen, x is a number from 1.9 to 4, y is a number
20 from 0 to 20, and preferred values for x are 2, 3 or 4.
Crystalline phyllosilicates of this kind are described,
for example, in European Patent Application EP-A-0 164
514. Preferred crystalline phyllosilicates of the
formula indicated are those in which M is sodium and x
adopts the value 2 or 3. In particular, both (3- and
8-sodium disilicates NazSizO5~yH20 are preferred,
~i-sodium disilicate, for example, being obtainable by
the process described in International Patent
Application WO-A-91/08171.
It is also possible to use amorphous sodium silicates
having an Na20:Si0z modulus of from 1:2 to 1:3.3,
preferably from 1:2 to 1:2.8, and in particular from
1:2 to 1:2.6, which are dissolution-retarded and have
secondary washing properties. The retardation of
dissolution relative to conventional amorphous sodium
silicates may have been brought about in a variety of
ways - for example, by surface treatment, compounding,
CA 02313356 2000-07-04
21
compacting, or overdrying. In the context of this
invention, the term "amorphous" also embraces "X-ray-
amorphous". This means that in X-ray diffraction
experiments the silicates do not yield the sharp X-ray
reflections typical of crystalline substances but
instead yield at best one or more maxima of the
scattered X-radiation, having a width of several degree
units of the diffraction angle. However, good builder
properties may result, even particularly good builder
properties, if the silicate particles in electron
diffraction experiments yield vague or even sharp
diffraction maxima. The interpretation of this is that
the products have microcrystalline regions with a size
of from 10 to several hundred nm, values up to max.
50 nm and in particular up to max. 20 nm being
preferred. So-called X-ray-amorphous silicates of this
kind, which likewise possess retarded dissolution
relative to the conventional waterglasses, are
described, for example, in German Patent Application
DE-A-44 00 024. Particular preference is given to
compacted amorphous silicates, compounded amorphous
silicates, and overdried X-ray-amorphous silicates.
In processes which are preferred in the context of the
present invention the deformable masses) comprises)
silicate(s), preferably alkali metal silicates, with
particular preference crystalline or amorphous alkali
metal disilicates, in amounts of from 10 to 60% by
weight, preferably from 15 to 50% by weight, and in
particular from 20 to 40% by weight, based in each case
on the mass.
Here again, the comments made above regarding the water
content of the masses are applicable. Processes which
have been found to be preferred are, in particular,
those wherein the weight ratio of silicates) to water
in the deformable mass is less than 1:0.25, preferably
less than 1:0.2, and in particular less than 1:0.15.
CA 02313356 2000-07-04
22
Likewise suitable as an important component in the
masses for processing in accordance with the invention
are substances from the group of the zeolites. These
substances constitute preferred builders especially in
connection with the production of laundry detergent
tablets. Zeolites have the general formula
M2~n0 ' A1203 ' X 5102 ' y Hz0
in which M is a cation of valence n, x is greater than
or equal to 2, and y may adopt values between 0 and 20.
The zeolite structures are formed by linking of A104
tetrahedra with Si04 tetrahedra, this network being
occupied by cations and water molecules. The cations in
these structures are relatively mobile and may be
replaced to different degrees by other cations. The
intercrystalline "zeolitic" water may be released,
continuously and reversibly depending on zeolite type,
while with certain types of zeolite structural changes
are also associated with the release and/or uptake of
water.
Within the structural subunits, the "primary binding
units" (A104 tetrahedra and Si04 tetrahedra) form so-
called "secondary binding units", which possess the
form of single or multiple rings. For example, in
various zeolites there are 4-, 6- and 8-membered rings
(referred to as S4R, S6R and S8R), while other types
are joined by way of four- and six-membered double-ring
prisms (commonest types: D4R as a tetragonal and D6R as
a hexagonal prism). These "secondary subunits" join
different polyhedra, which are referred to using Greek
letters. The most widespread in this context is a poly-
hedron composed of six squares and eight equilateral
hexagons, which is referred to as "~i". Using these
building units, it is possible to produce many
different zeolites. Known to date are 34 natural
CA 02313356 2000-07-04
23
zeolite minerals and approximately 100 synthetic
zeolites.
The best-known zeolite, zeolite 4 A, is a cubic
assembly of (3 cages linked by D4R subunits. It belongs
to the zeolite structural group 3 and its three-
dimensional network has pores of 2.2 A and 4.2 A in
size; the formula unit in the unit cell may be
described by Nalz [ (AlOz) iz (SiOz) lz] ' 27 H20.
In the process of the invention it is preferred to use
zeolites of the faujasite type. Together with the
zeolites X and Y, the mineral faujasite belongs to the
faujasite types within the zeolite structural group 4,
which is characterized by the double-hexagon subunit
D6R (compare Donald W. Breck: "Zeolite Molecular
Sieves", John Wiley & Sons, New York, London, Sydney,
Toronto, 1974, page 92). In addition to the above-
mentioned faujasite types, the zeolite structural group
4 also includes the minerals chabazite and gmelinite
and also the synthetic zeolite R (chabazite type), S
(gmelinite type), L, and ZK-5. The two last-mentioned
synthetic zeolites have no mineral analogs.
Zeolites of the faujasite type are composed of ~3 cages
linked tetrahedrally by way of D6R subunits, the (3
cages being arranged in a manner similar to the carbon
atoms in diamond. The three-dimensional network of the
faujasite-type zeolites used in the process of the
invention has pores of 2.2 and 7.4 A; the unit cell
includes, moreover, 8 cavities having a diameter of
approximately 13 A and may be described by the formula
Naes [ (AlOz) es (SiOz) lost ~ 264 HzO. The network of zeolite X
includes a cavity volume of approximately 50~, based on
the dehydrated crystal, which constitutes the largest
empty space of all known zeolites (zeolite Y: approxim-
ately 48~ cavity volume, faujasite: approximately 47~
cavity volume). (All data from: Donald W. Breck:
CA 02313356 2000-07-04
24
"Zeolite Molecular Sieves", John Wiley & Sons, New
York, London, Sydney, Toronto, 1974, pages 145, 176,
177 . )
In the context of the present invention, the term
"faujasite-type zeolite" denotes all three zeolites
which form the faujasite subgroup of the zeolite
structural group 4. In addition to zeolite X, there-
fore, zeolite Y and faujasite, and mixtures of these
compounds, may be used in accordance with the
invention, preference being given to straight zeolite
X.
Mixtures or cocrystallizates of zeolites of the
faujasite type with other zeolites, which need not
necessarily belong to the zeolite structural group 4,
may also be used in accordance with the invention, the
advantages of the process of the invention being mani-
fested particularly if at least 50% by weight of the
powdering agent comprises a faujasite-type zeolite. It
is also conceivable, for example, to use the minimum
amount of a faujasite-type zeolite (0.5% by weight,
based on the weight of the tablet being produced) and
to use conventional zeolite A as the remaining powder-
ing agent. In any case, however, it is preferred for
the powdering agent to consist exclusively of one or
more faujasite-type zeolites, with zeolite X again
being preferred.
The aluminum silicates which are used with preference
in the process of the invention are commercially
available, and the methods of their preparation are
described in standard monographs.
Examples of commercially available zeolites of the X
type may be described by the following formulae:
Naas [ (A102) as (SiOz) los] 'x H20,
CA 02313356 2000-07-04
K86 [ (Al Oz) 86 (SlOz) 106 'X HzO,
Ca4oNas [ (AlOz) ss (SiOz) 106 'x H20,
5
SrzlBazz [ (AlOz ) as ( SiOz ) los ~ ' x HzO,
in which x may adopt values of between 0 and 276, and
which have pore sizes of from 8.0 to 8.4 A.
A product available commercially and able to be used
with preference in the context of the present inven-
tion, for example, is a cocrystallizate of zeolite X
and zeolite A (approximately 80a by weight zeolite X),
which is sold by CONDEA Augusta S.p.A. under the brand
name VEGOBOND AX~ and may be described by the formula
nNazO~ (1-n) K2O~AlzO3~ (2-2 . 5) SiOz~ (3 . 5-5. 5) H20.
Zeolites of the Y type are also commercially available
and may be described, for example, by the formulae
Nass [ (AlO2) s6 (SlO2) 136 'X HzO,
Kss [ (AlOz) ss (SiOz) 13s~ 'X HzO,
in which x stands for numbers between 0 and 276, and
which have pore sizes of 8.0 A.
Preferred processes are those wherein the deformable
masses) comprises) zeolite(s), preferably zeolite A,
zeolite P, zeolite X and mixtures thereof, in amounts
of from 10 to 60~ by weight, preferably from 15 to 50~
by weight, and in particular from 20 to 40~ by weight,
based in each case on the mass.
The particle sizes of the faujasite-type zeolites used
with preference in the process of the invention is
CA 02313356 2000-07-04
26
preferably within the range from 0.1 up to 100 Vim, more
preferably between 0.5 and 50 Vim, and in particular
between 1 and 30 Vim, in each case measured with
standard particle size determination methods.
It is generally preferred in this context to use finely
divided solids in the masses for processing in accord-
ance with the invention, irrespective of whether said
solids comprise the abovementioned zeolites or other
builders or bleaches, bleach activators or other
solids. Very generally, preference is given to process
variants wherein the average particle size of the
solids used in the deformable masses) is below 400 Vim,
preferably below 300 Vim, and in particular below
200 Vim.
The average particle size in this case is the
arithmetic mean of the individual particle sizes, which
may vary. Particularly preferred processes are those
wherein less than 10% by weight, preferably less than
5% by weight, and in particular less than 1% by weight,
of the solids used in the deformable masses) have
particle sizes above 1000 Vim. The upper particle size
range may be narrowed even further, so that particu-
larly preferred processes are those wherein less than
15% by weight, preferably less than 10% by weight, and
in particular less than 5% by weight, of the solids
used in the deformable masses) have particle sizes
above 800 Vim.
In general, however, even narrower particle size dis-
tributions are preferred, where the breadth of fluc-
tuation about the average particle size is not more
than 50%, preferably not more than 40%, and in particu-
lar not more than 30%, of the average particle size;
i.e., the particle sizes make up at least 0.7 times and
at most 1.3 times the average particle size.
CA 02313356 2000-07-04
27
Above, the weight ratio of water to certain ingredients
in masses preferred in accordance with the invention
for processing has been specified. After processing,
this water is preferably bound in the form of hydrate
water, so that the process end products preferably have
a significantly lower free water content. Preferred end
products of the process of the invention are essen-
tially water-free; i.e., in a state in which the amount
of liquid water, i.e., water not present in the form of
hydrate water and/or constitution water, is less than
2% by weight, preferably less than 1% by weight, and in
particular even below 0.5% by weight, based in each
case on the tablets: Accordingly, preferred processes
of the invention are those wherein the tablets comprise
less than 10% by weight, preferably less than 5% by
weight, with particular preference less than 1% by
weight, and in particular less than 0.5% by weight, of
free water. Water may accordingly be present essen-
tially only in chemically and/or physically bound form
or as a constituent of the solid raw materials or
compounds, but not as a liquid, solvent or dispersion,
in the end products of the process of the invention.
Advantageously, the tablets at the end of the produc-
tion process of the invention have an overall water
content of not more than 15% by weight, with this
water, therefore, being present not in liquid, free
form but instead in chemically and/or physically bound
form, and it is particularly preferred for the amount
of water that is not bound to zeolite and/or to
silicates in the solid premix to amount to not more
than 10% by weight and in particular not more than 7%
by weight.
Process end products which are particularly preferred
in the context of the present invention not only
possess an extremely small proportion of free water but
are preferably themselves still able to bind further
free water. In preferred processes, the water content
CA 02313356 2000-07-04
28
of the tablets is from 50 to 100% of the calculated
water binding capacity.
The water binding capacity is the ability of a sub-
s stance (in this case, of the process end product) to
absorb water in chemically stable form, and ultimately
indicates the amount of water which can be bound in the
form of stable hydrates by a substance or by a tablet .
The dimensionless value of the water binding capacity
(WBC) is calculated from:
~C,_n~18
M
where n is the number of water molecules in the
corresponding hydrate of the substance and M is the
molar mass of the unhydrated substance. For the water
binding capacity of anhydrous sodium carbonate
(formation of sodium carbonate monohydrate), for
example, this gives a value of
1.18
WBC = = 0.17.
223+12+316
The value WBC may be calculated for all hydrate-forming
substances that are used in the masses for processing
in accordance with the invention. The percentage
proportions of these substances then produce the over-
all water binding capacity of the formulation. In
preferred process end products, then, the water content
is between 50 and 100% of this calculated value.
In addition to the water content of the process end
products and the ratio of water to certain raw mater-
ials, it is also to make statements about the absolute
water content of the masses for processing in accord-
ance with the invention. In particularly preferred
processes, the deformable masses) in the course of
CA 02313356 2000-07-04
29
processing has (have) a water content of from 2.5 to
30% by weight, preferably from 5 to 25% by weight, and
in particular from 7.5 to 20% by weight, based in each
case on the mass.
A further mechanism for the hardening of the masses
processed in the process of the invention consists in
the cooling of the masses during processing above their
softening point. Processes wherein the hardening of the
deformable masses) takes place by cooling below the
melting point, accordingly, are preferred.
Masses which may be softened under the action of
temperature may easily be formulated by mixing the
desired further ingredients with a meltable or soften-
able substance, and heating the mixture to temperatures
within the softening range of this substance and
shaping the mixture at these temperatures. It is
particularly preferred in this case to use waxes,
paraffins, polyalkylene glycols, etc., as meltable or
softenable substances. These substances are described
below.
The meltable or softenable substances should have a
melting range (solidification range) situated within a
temperature range in which the other ingredients of the
masses to be processed are not exposed to any excessive
thermal load. On the other hand, however, the melting
range must be sufficiently high still to provide a
handleable tablet at at least slightly elevated
temperature. In masses preferred in accordance with the
invention, the meltable or softenable substances have a
melting point above 30°C.
It has proven advantageous for the meltable or
softenable substances not to exhibit a sharply defined
melting point, as encountered commonly with pure,
crystalline substances, but instead to have a melting
CA 02313356 2000-07-04
range which covers, in some cases, several degrees
Celsius. The meltable or softenable substances
preferably have a melting range which lies between
about 45°C and above 75°C. In the present case that
5 means that the melting range occurs within the stated
temperature interval, and does not denote the width of
the melting range. The width of the melting range is
preferably at least 1°C, more preferably from about 2
to about 3°C.
The abovementioned properties are in general possessed
by what are called waxes. The term "waxes" is applied
to a range of natural or synthetic substances which
melt without decomposition, generally at above 40°C,
and are of comparatively low viscosity, without
stringing, at just a little above the melting point.
They have a highly temperature-dependent consistency
and solubility.
According to their origin, the waxes are divided into
three groups: the natural waxes, chemically modified
waxes, and the synthetic waxes.
The natural waxes include, for example, plant waxes
such as candelilla wax, carnauba wax, Japan wax,
esparto grass wax, cork wax, guaruma wax, rice germ oil
wax, sugarcane wax, ouricury wax, or montan wax, animal
waxes such as beeswax, shellac wax, spermaceti, lanolin
(wool wax), uropygial grease, mineral waxes such as
ceresin or ozokerite (earth wax), or petrochemical
waxes such as petrolatum, paraffin waxes or
microcrystalline waxes.
The chemically modified waxes include, for example,
hard waxes such as montan ester waxes, sassol waxes, or
hydrogenated jojoba waxes.
CA 02313356 2000-07-04
31
By synthetic waxes are meant, in general, polyalkylene
waxes or polyalkylene glycol waxes. As meltable or
softenable substances for the masses which harden by
cooling it is also possible to use compounds from other
classes of substance which meet the stated requirements
in terms of softening point. Examples of synthetic
compounds which have proven suitable are higher esters
of phthalic acid, especially dicyclohexyl phthalate,
which is available commercially under the name Unimoll~
66 (Bayer AG). Also suitable are synthetically prepared
waxes from lower carboxylic acids and fatty alcohols,
an example being dimyristyl tartrate, which is
available under the name Cosmacol~ ETLP (Condea).
Conversely, synthetic or partially synthetic esters of
lower alcohols with fatty acids from natural sources
may also be used. This class of substance includes, for
example, Tegiri 90 (Goldschmidt), a glyceryl mono-
stearate palmitate. Shellac as well, for example,
Schellack-KPS-Dreiring-SP (Kalkhoff GmbH), may be used
according to the invention as meltable or softenable
substances.
Likewise counted among the waxes in the context of the
present invention are, for example, the so-called wax
alcohols. Wax alcohols are relatively high molecular
mass, water-insoluble fatty alcohols having in general
from about 22 to 40 carbon atoms. The wax alcohols
occur, for example, in the form of wax esters of
relatively high molecular mass fatty acids (wax acids)
as a principal constituent of many natural waxes.
Examples of wax alcohols are lignoceryl alcohol (1-
tetracosanol), cetyl alcohol, myristyl alcohol, and
melissyl alcohol. The coating of the particulate solids
coated in accordance with the invention may, if
desired, also include wool wax alcohols, by which are
meant triterpenoid and steroid alcohols, an example
being lanolin, which is available under the commercial
designation Argowax~ (Pamentier & Co.), for example.
CA 02313356 2000-07-04
32
Likewise possible for use, at least proportionally, as
a constituent of the coating are, in the context of the
present invention, fatty acid glycerol esters or fatty
acid alkanolamides, and also, if desired, water-
s insoluble or only sparingly water-soluble polyalkylene
glycol compounds.
Particularly preferred meltable or softenable
substances in the masses for processing are those from
the group consisting of polyethylene glycols (PEG)
and/or polypropylene glycols (PPG), preference being
given to polyethylene glycols having molecular masses
of between 1500 and 36,000, particular preference to
those having molecular masses of from 2000 to 6000, and
special preference to those having molecular masses of
from 3000 to 5000. Corresponding processes wherein the
plastically deformable masses) comprises) at least
one substance from the group of polyethylene glycols
(PEG) and/or polypropylene glycols (PPG) are also
preferred.
In this context, particularly preferred masses for
processing in accordance with the invention are those
comprising polypropylene glycols (PPG) and/or
polyethylene glycols (PEG) as sole meltable or
softenable substances. Polypropylene glycols
(abbreviation PPG) which may be used in accordance with
the invention are polymers of propylene glycol which
satisfy the general formula I
H-~o-cH-cH2y-off ( I )
I
CH3
where n can adopt values between 10 and 2000. Preferred
PPGs have molecular masses of between 1000 and 10,000
CA 02313356 2000-07-04
33
and, correspondingly, values of n of between 17 and
approximately 170.
Polyethylene glycols (abbreviation PEG) which may be
used with preference in accordance with the invention
are polymers of ethylene glycol which satisfy the
general formula II
H- (O-CHZ-CH2) n-OH ( I I )
where n can adopt values between 20 and approximately
1000. The abovementioned preferred molecular weight
ranges correspond in this case to preferred ranges for
the value n in formula II of from about 30 to about 820
(to be exact: from 34 to 818), with particular
preference from about 40 to about 150 (to be exact:
from 45 to 136), and in particular from about 70 to
about 120 (to be exact: from 68 to 113).
In another preferred embodiment, the masses for
processing in accordance with the invention comprise
paraffin wax in the predominant fraction. That means
that at least 50% by weight of the total meltable or
softenable substances present, preferably more, consist
of paraffin wax. Particularly suitable are paraffin wax
contents (based on total meltable or softenable
substances) of approximately 60% by weight,
approximately 70% by weight or approximately 80% by
weight, with special preference being given to even
higher proportions, of, for example, more than 90% by
weight. In one particular embodiment of the invention,
the total amount of the meltable or softenable
substances used consists exclusively of paraffin wax.
Relative to the other, natural waxes mentioned,
paraffin waxes have the advantage in the context of the
present invention that in an alkaline cleaning product
environment there is no hydrolysis of the waxes (as is
CA 02313356 2000-07-04
34
to be expected, for example, with the wax esters),
since paraffin wax contains no hydrolyzable groups.
Paraffin waxes consist primarily of alkanes, plus low
fractions of isoalkanes and cycloalkanes. The paraffin
for use in accordance with the invention preferably
contains essentially no constituents having a melting
point of more than 70°C, with particular preference of
more than 60°C. Below this melting temperature in the
cleaning product liquor, fractions of high-melting
alkanes in the paraffin may leave unwanted wax residues
on the surfaces to be cleaned or on the ware to be
cleaned. 4dax residues of this kind lead in general to
an unattractive appearance of the cleaned surface and
should therefore be avoided.
Masses for processing with preference comprise as
meltable or softenable substances at least one paraffin
wax having a melting range from 50°C to 60°C, preferred
processes being those wherein deformable masses)
comprises) a paraffin wax having a melting range of
from 50°C to 55°C.
Preferably, the amount of alkanes, isoalkanes and
cycloalkanes which are solid at ambient temperature
(generally from about 10 to about 30°C) in the paraffin
wax used is as high as possible. The larger the amount
of solid wax constituents in a wax at room temperature,
the more useful that wax is in the context of the
present invention. As the proportion of solid wax
constituents increases, there is an increase in the
resistance of the process end products to impacts or
friction on other surfaces, resulting in a longer-
lasting protection. High proportions of oils or liquid
wax constituents may weaken the tablets or tablet
regions, as a result of which pores are opened and the
active substances are exposed to the ambient influences
mentioned at the outset.
CA 02313356 2000-07-04
In addition to paraffin as main constituent, the
meltable or softenable substances may further comprise
one or more of the abovementioned waxes or waxlike
5 substances. In a further preferred embodiment of the
present invention, the mixture forming the meltable or
softenable substances should be such that the mass and
the tablets or tablet constituent formed from it are at
least substantially water-insoluble. At a temperature
10 of about 30°C, the solubility in water should not
exceed about 10 mg/1 and preferably should be below
5 mg/1.
In such cases, however, the meltable or softenable
15 substances should have as low a solubility in water as
possible, even in water at elevated temperature, in
order as far as possible to avoid temperature-
independent release of the active substances.
20 The principle described above is used for the delayed
release of ingredients at a particular point in time in
the cleaning operation and can be employed with
particular advantage if rinsing is carried out in the
main rinse cycle at a relatively low temperature (for
25 example, 55°C), so that the active substance is not
released from the rinse aid particles until the rinse
cycle at higher temperatures (approximately 70°C). .
Preferred masses to be processed in accordance with the
30 invention comprise as meltable or softenable substances
one or more substances having a melting range of from
40°C to 75°C in amounts of from 6 to 30% by weight,
preferably from 7.5 to 25% by weight, and in particular
from 10 to 20% by weight, based in each case on the
35 weight of the mass.
A further mechanism by which the masses may harden is
the evaporation of solvents. To this end it is possible
CA 02313356 2000-07-04
36
to prepare solutions or dispersions of the desired
ingredients in one or more suitable, volatile solvents,
said solutions or dispersions emitting this (these)
solvents) after the shaping step and, in so doing,
hardening. Examples of appropriate solvents are lower
alkanols, aldehydes, ethers, esters, etc., which are
selected in accordance with the further composition of
the masses for processing. Particularly suitable sol-
vents for such processes wherein the deformable
masses) hardens) by evaporation of solvents are
ethanol, propanol, isopropanol, 1-butanol, 2-butanol,
2-methyl-1-propanol, 2-methyl-2-propanol, 1-pentanol,
2-pentanol, 3-pentanol, 2,2-dimethyl-1-propanol,
3-methyl-1-butanol, 3-methyl-2-butanol, 2-methyl-2-
butanol, 2-methyl-1-butanol, 1-hexanol, and the
acetates of the abovementioned alcohols, especially
ethyl acetate.
The evaporation of the abovementioned solvents may be
accelerated by heating after shaping and cutting to
length, or by air movement. Combinations of the
measures specified are also suitable for this purpose,
for example, the blowing of the cut-to-length tablets
with warm or hot air.
A further mechanism which may form the basis for the
hardening of the shaped and cut-to-length masses is
that of crystallization. Processes wherein the deform
able masses) hardens) by crystallization are likewise
preferred.
Crystallization, as a mechanism on which the hardening
is based, may be utilized by using, for example, melts
of crystalline substances as the basis of one or more
shapable masses. Following processing, systems of this
kind undergo transition to a higher state of order,
which in turn leads to hardening of the overall tablet
formed. Alternatively, crystallization may take place
CA 02313356 2000-07-04
37
by crystallization from supersaturated solution. In the
context of the present invention, supersaturation
refers to a metastable state in which, in a closed
system, more of one substance is present than is
required for saturation. A supersaturated solution
obtained, for example, by undercooling accordingly com-
prises more dissolved substance than it should contain
in thermal equilibrium. The excess of dissolved sub-
stance may be brought to instantaneous crystallization
by seeding with seed crystal or dust particles or by
agitating the system. In the context of the present
invention, the term "supersaturated" always refers to a
temperature of 20°C. If x grams of a substance per
liter dissolve in a defined solvent at a temperature of
20°C, then the solution, in the context of the present
invention, may be referred to as "supersaturated" if it
contains (x + y) grams of the substance per liter, y
being > 0. Consequently, in the context of the present
invention, solutions referred to as "supersaturated"
include those which at an elevated temperature are used
as the basis of a mass for processing and are processed
at this temperature, in which more dissolved substance
is present in the solution than would dissolve in the
same amount of solvent at 20°C.
The term "solubility" is understood by the present
invention to mean the maximum amount of a substance
which the solvent is able to accommodate at a certain
temperature, i.e., the fraction of the dissolved
substance in a solution saturated at the temperature in
question. Where a solution contains more dissolved sub-
stance than it should contain in thermodynamic equili-
brium at a given temperature (for example, in the case
of undercooling), it is referred to as supersaturated.
By seeding with seed crystals it is possible to cause
the excess to precipitate as a sediment in the
solution, which is now just saturated. A solution
saturated in respect of a substance may, however, also
CA 02313356 2000-07-04
38
dissolve other substances (for example, it is still
possible to dissolve sugar in a saturated solution of
common salt).
The state of supersaturation can be achieved, as
described above, by slow cooling or by undercooling of
a solution, provided the dissolved substance is more
soluble in the solvent at higher temperatures. Other
possibilities to obtain supersaturated solutions are,
for example, the combination of two solutions whose
ingredients react to form another substance which does
not immediately precipitate (hindered or retarded
precipitation reactions). The latter mechanism is
particularly suitable as a basis for the formation of
masses for processing in accordance with the invention.
In principle, the state of supersaturation is achiev-
able in any kind of solution, although the principle
described in the present specification finds its
application, as already mentioned, in the production of
laundry detergents and cleaning products. Accordingly,
some systems, which in principle tend to form super-
saturated solutions, are less suitable for use in
accordance with the invention, since the systems of
substance on which they are based cannot be used, on
Pnvirnnmr~ntal. toxiCOlOQI.Cal, or economic crrounds. In
addition to nonionic surfactants or common nonaqueous
solvents, therefore, particular preference is given to
processes of the invention with the last-mentioned
hardening mechanism wherein a supersaturated aqueous
solution is used as the basis of at least one mass for
processing.
As already mentioned above, the state of supersatura-
tion in the context of the present invention refers to
the saturated solution at 20°C. By using solutions
which have a temperature above 20°C it is easy to
attain the state of supersaturation. Process of the
CA 02313356 2000-07-04
39
invention wherein the crystallization-hardening mass
during processing has a temperature of between 35 and
120°C, preferably between 40 and 110°C, with particular
preference between 45 and 90°C, and in particular
between 50 and 80°C, are preferred in the context of
the present invention.
Since the laundry detergent and cleaning product
tablets produced are generally neither stored at
elevated temperatures nor later used at these elevated
temperatures, the cooling of the mixture leads to the
precipitation from the supersaturated solution of the
fraction of dissolved substance which was present in
the solution above the saturation limit at 20°C. Thus,
on cooling, the supersaturated solution may divided
into a saturated solution and a sediment. An alter-
native possibility is that, owing to recrystallization
and hydration phenomena, the supersaturated solution
solidifies on cooling to form a solid. This is the
case, for example, if certain salts containing
hydration water dissolve in their water of
crystallization on heating. In this case,
supersaturated solutions are often formed on cooling
which by mechanical action or addition of seed crystal
to a solid - the salt, containing water of
crystallization, as the state which is
thermodynamically stable at room temperature -
solidify. This phenomenon is known, for example, for
sodium thiosulfate pentahydrate and sodium acetate
trihydrate, the latter salt in particular, containing
hydration water, being suitable for use with advantage
in the form of the supersaturated solution in the
process of the invention. Specific laundry detergent
and cleaning product ingredients as well, such as
phosphonates, for example, display this phenomenon and
are outstandingly suitable in the form of the solutions
as granulation aids. For this purpose the corresponding
phosphonic acids (see below) are neutralized with
CA 02313356 2000-07-04
concentrated alkali, the solution becoming heated as a
result of the heat of neutralization. On cooling, these
solutions form solids of the corresponding alkali metal
phosphonates. By incorporating further laundry deter-
s gent and cleaning product ingredients into the
solutions while still hot, it is possible in accordance
with the invention to prepare processable masses of
different composition. Particularly preferred processes
of the invention are those wherein the supersaturated
10 solution used as a basis of the hardening mass
solidifies at room temperature to form a solid. It is
preferred in this case that the formerly supersaturated
solution, following solidification to form a solid,
cannot be converted back into a supersaturated solution
15 by heating to the temperature at which the super-
saturated solution was formed. This is the case, for
example, with the phosphonates mentioned.
As mentioned above, the supersaturated solution used as
20 a basis of the hardening mass may be obtained in a
number of ways and then processed in accordance with
the invention following optional admixing of further
ingredients. One simple way, for example, is to prepare
the supersaturated solution which is used as the basis
25 of the hardening mass by dissolving the dissolved sub-
stance in heated solvent. If the amounts of the
dissolved substance that are dissolved in this way in
the heated solvent are higher than those which would
dissolve at 20°C, then a solution is present which is
30 supersaturated within the meaning of the present
invention and which either hot (see above) or after
cooling, and in the metastable state, may be introduced
into the mixer.
35 A further possibility is to remove the water from salts
containing hydration water by "dry" heating and to
dissolve them in their own water of crystallization
(see above). This too is a method of preparing super-
CA 02313356 2000-07-04
41
saturated solutions that may be used in the context of
the present invention.
Another way is to add a gas or other fluid or solution
to a non-supersaturated solution, so that the dissolved
substance reacts in the solution to form a less soluble
substance or dissolved to a lesser extent in the
mixture of the solvents. The combination of two
solutions each containing two substances which react
with one another to form a less soluble substance is
likewise a method of preparing supersaturated solu-
tions, provided the less-soluble substance does not
precipitate instantaneously. Processes which are like-
wise preferred in the context of the present invention
are those wherein the supersaturated solution used as
the basis of the hardening mass is prepared by combin-
ing two or more solutions. Examples of such ways of
preparing supersaturated solutions are dealt with
below.
Preferred processes of the invention are those wherein
the supersaturated aqueous solution is obtained by
combining an aqueous solution of one or more acidic
ingredients of laundry detergents and cleaning pro-
ducts, preferably from the group of the surfactant
acids, the builder acids, and the complexing agent
acids, and an aqueous alkali solution, preferably an
aqueous alkali metal hydroxide solution, in particular
an aqueous sodium hydroxide solution.
Among the representatives of said classes of compound
that have already been mentioned earlier on above, the
phosphonates in particular occupy an outstanding
position in the context of the present invention. In
preferred processes of the invention, therefore, the
supersaturated aqueous solution is obtained by combin-
ing an aqueous phosphonic acid solution with concentra-
tions above 45% by weight, preferably above 50% by
CA 02313356 2000-07-04
42
weight, and in particular above 55% by weight, based in
each case on the phosphonic acid solution, and an
aqueous sodium hydroxide solution with concentrations
above 35% by weight, preferably above 40% by weight,
and in particular above 45% by weight, based in each
case on the sodium hydroxide solution.
The hardening of the deformable masses) may, in
accordance with the invention, also take place by means
of chemical reaction(s), especially addition polymeri-
zation. Suitable in this context, in principle, are all
chemical reactions which, starting from one or more
liquid to paste-like substances, lead, by reaction with
(an)other substance(s), to solids. Especially suitable
in this context are chemical reactions which do not
lead suddenly to said change of state. From the multi-
tude of chemical reactions which lead to solidification
phenomena, suitable reactions are in particular those
in which larger molecules are built up from smaller
molecules. These reactions include, in turn, preferably
reactions in which many small molecules react to form
(one) larger molecule(s). These are what are known as
polymerization reactions (polyaddition, addition
polymerization, polycondensation) and polymer-analogous
reactions. The corresponding addition polymers,
polyadducts (poly-addition products) or polycondensates
(polycondensation products) then give the finished,
cut-to-length tablet its strength.
In view of the intended use of the products produced in
accordance with the invention it is preferred to
utilize as hardening mechanism the formation of those
solid substances from liquid or paste-like starting
materials which are in any case to be used in the
laundry detergent and cleaning product as ingredients,
examples being cobuilders, soil repellents, and soil
release polymers. Such cobuilders may originate, for
example, from the groups of the polycarboxylates/poly-
CA 02313356 2000-07-04
43
carboxylic acids, polymeric polycarboxylates, aspartic
acid, polyacetals, dextrins, etc. These classes of
substance are described later on.
A further mechanism by which the deformable masses)
may harden in the context of the present invention is
that of hardening as a result of a change in rheo-
logical properties.
In this case, use is made of the property possessed by
certain substances of changing - in some instances,
drastically - their rheological properties under the
action of shear forces. Examples of such systems, which
are familiar to the skilled worker, are phyllosili-
Gates, for example, which under shearing have a highly
thickening action in appropriate matrices and may lead
to masses of firm consistency.
It is of course possible for two or more hardening
mechanisms to be combined with one another and/or used
simultaneously in one mass. Appropriate in this case,
for example, are crystallization with simultaneous
solvent evaporation, cooling with simultaneous
crystallization, water binding ("internal drying") with
simultaneous external drying, etc.
The general description of mechanisms which may form
the basis for hardening in the process of the invention
is followed by a detailed description of the other
ingredients to be used in the masses for processing.
Preferred end products of the process of the invention,
i.e. preferred laundry detergent and cleaning product
tablets, further comprise one or more surfactants.
Accordingly, it is preferred for at least one of the
masses for processing to comprise surfactant(s). In the
laundry detergent and cleaning product tablets of the
invention it is possible to use anionic, nonionic,
CA 02313356 2000-07-04
44
cationic and/or amphoteric surfactants, and/or mixtures
thereof. From a performance standpoint, preference is
given to mixtures of anionic and nonionic surfactants.
The total surfactant content of the tablets is for
laundry detergent tablets from 5 to 60~ by weight,
based on the tablet weight, preference being given to
surfactant contents of more than 15% by weight, while
cleaning product tablets for machine dishwashing
contain preferably less than 5% by weight of
surfactant (s) .
Anionic surfactants used are, for example, those of the
sulfonate and sulfate type. Preferred surfactants of
the sulfonate type are C9_13 alkylbenzenesulfonates,
olefinsulfonates, i.e., mixtures of alkenesulfonates
and hydroxyalkanesulfonates, and also disulfonates, as
are obtained, for example, from Clz-ie monoolefins having
a terminal or internal double bond by sulfonating with
gaseous sulfur trioxide followed by alkaline or acidic
hydrolysis of the sulfonation products. Also suitable
are alkanesulfonates, which are obtained from C12-18
alkanes, for example, by sulfochlorination or
sulfoxidation with subsequent hydrolysis or
neutralization, respectively. Likewise suitable, in
addition, are the esters of a-sulfo fatty acids (ester
sulfonates), e.g., the a-sulfonated methyl esters of
hydrogenated coconut, palm kernel or tallow fatty
acids.
Further suitable anionic surfactants are sulfated fatty
acid glycerol esters. Fatty acid glycerol esters are
the monoesters, diesters and triesters, and mixtures
thereof, as obtained in the preparation by
esterification of a monoglycerol with from 1 to 3 mol
of fatty acid or in the transesterification of
triglycerides with from 0.3 to 2 mol of glycerol.
Preferred sulfated fatty acid glycerol esters are the
sulfation products of saturated fatty acids having 6 to
CA 02313356 2000-07-04
22 carbon atoms, examples being those of caproic acid,
caprylic acid, capric acid, myristic acid, lauric acid,
palmitic acid, stearic acid, or behenic acid.
5 Preferred alk(en)yl sulfates are the alkali metal
salts, and especially the sodium salts, of the sulfuric
monoesters of Clz-Cla fatty alcohols, examples being
those of coconut fatty alcohol, tallow fatty alcohol,
lauryl, myristyl, cetyl or stearyl alcohol, or of Clo_Czo
10 oxo alcohols, and those monoesters of secondary
alcohols of these chain lengths. Preference is also
given to alk(en)yl sulfates of said chain length which
contain a synthetic straight-chain alkyl radical
prepared on a petrochemical basis, these sulfates
15 possessing degradation properties similar to those of
the corresponding compounds based on fatty-chemical raw
materials. From a detergents standpoint, the Clz-Cls
alkyl sulfates and Clz-Cls alkyl sulfates, and also
C14-Cls alkyl sulfates, are preferred. In addition, 2, 3-
20 alkyl sulfates, which may for example be prepared in
accordance with US Patents 3,234,258 or 5,075,041 and
obtained as commercial products from Shell Oil Company
under the name DAN~, are suitable anionic surfactants.
25 Also suitable are the sulfuric monoesters of the
straight-chain or branched C7_zl alcohols ethoxylated
with from 1 to 6 mol of ethylene oxide, such as
2-methyl-branched C9_11 alcohols containing on average
3.5 mol of ethylene oxide (EO) or Clz-la fatty alcohols
30 containing from 1 to 4 EO. Because of their high
foaming behavior they are used in cleaning products
only in relatively small amounts, for example, in
amounts of from 1 to 5% by weight.
35 Further suitable anionic surfactants include the salts
of alkylsulfosuccinic acid, which are also referred to
as sulfosuccinates or as sulfosuccinic esters and which
constitute monoesters and/or diesters of sulfosuccinic
CA 02313356 2000-07-04
' 46
acid with alcohols, preferably fatty alcohols and
especially ethoxylated fatty alcohols. Preferred
sulfosuccinates comprise C8_18 fatty alcohol radicals or
mixtures thereof. Especially preferred sulfosuccinates
contain a fatty alcohol radical derived from
ethoxylated fatty alcohols which themselves represent
nonionic surfactants (for description, see below).
Particular preference is given in turn to
sulfosuccinates whose fatty alcohol radicals are
derived from ethoxylated fatty alcohols having a
narrowed homolog distribution. Similarly, it is also
possible to use alk(en)ylsuccinic acid containing
preferably 8 to 18 carbon atoms in the alk(en)yl chain,
or salts thereof.
Further suitable anionic surfactants are, in
particular, soaps. Suitable soaps include saturated
fatty acid soaps, such as the salts of lauric acid,
myristic acid, palmitic acid, stearic acid,
hydrogenated erucic acid and behenic acid, and, in
particular, mixtures of soaps derived from natural
fatty acids, e.g., coconut, palm kernel, or tallow
fatty acids.
The anionic surfactants, including the soaps, may be
present in the form of their sodium, potassium or
ammonium salts and also as soluble salts of organic
bases, such as mono-, di- or triethanolamine.
Preferably, the anionic surfactants are in the form of
their sodium or potassium salts, in particular in the
form of the sodium salts.
Nonionic surfactants used are preferably alkoxylated,
advantageously ethoxylated, especially primary,
alcohols having preferably 8 to 18 carbon atoms and on
average from 1 to 12 mol of ethylene oxide (EO) per
mole of alcohol, in which the alcohol radical may be
linear or, preferably, methyl-branched in position 2
CA 02313356 2000-07-04
' 47
.and/or may comprise linear and methyl-branched radicals
in a mixture, as are commonly present in oxo alcohol
radicals. In particular, however, preference is given
to alcohol ethoxylates containing linear radicals from
alcohols of natural origin having 12 to 18 carbon
atoms, e.g., from coconut, palm, tallow fatty or oleyl
alcohol, and on average from 2 to 8 EO per mole of
alcohol. Preferred ethoxylated alcohols include, for
example, Clz-14 alcohols containing 3 EO or 4 EO, C9_11
alcohol containing 7 EO, Cla-is alcohols containing 3 EO,
5 EO, 7 EO or 8 EO, Clz-la alcohols containing 3 EO, 5 EO
or 7 EO, and mixtures thereof, such as mixtures of Clz-14
alcohol containing 3 EO and Clz-la alcohol containing
5 EO. The stated degrees of ethoxylation represent
statistical mean values, which for a specific product
may be an integer or a fraction. Preferred alcohol
ethoxylates have a narrowed homolog distribution
(narrow range ethoxylates, NREs). In addition to these
nonionic surfactants it is also possible to use fatty
alcohols containing more than 12 EO. Examples thereof
are tallow fatty alcohol containing 14 EO, 25 EO, 30 EO
or 40 EO.
As further nonionic surfactants, furthermore, use may
also be made of alkyl glycosides of the general formula
RO(G)X, where R is a primary straight-chain or methyl-
branched aliphatic radical, especially an aliphatic
radical methyl-branched in position 2, containing 8 to
22, preferably 12 to 18, carbon atoms, and G is the
symbol representing a glycose unit having 5 or 6 carbon
atoms, preferably glucose. The degree of
oligomerization, x, which indicates the distribution of
monoglycosides and oligoglycosides, is any desired
number between 1 and 10; preferably, x is from 1.2 to
1.4.
A further class of nonionic surfactants used with
preference, which are used either as sole nonionic
CA 02313356 2000-07-04
48
surfactant or in combination with other nonionic
surfactants, are alkoxylated, preferably ethoxylated,
or ethoxylated and propoxylated, fatty acid alkyl
esters, preferably having 1 to 4 carbon atoms in the
alkyl chain, especially fatty acid methyl esters, as
are described, for example, in Japanese Patent
Application JP 58/217598, or those prepared preferably
by the process described in International Patent
Application WO-A-90/13533.
Nonionic surfactants of the amine oxide type, examples
being N-cocoalkyl-N,N-dimethylamine oxide and
N-tallowalkyl-N,N-dihydroxyethylamine oxide, and of the
fatty acid alkanolamide type, may also be suitable. The
amount of these nonionic surfactants is preferably not
more than that of the ethoxylated fatty alcohols, in
particular not more than half thereof.
Further suitable surfactants are polyhydroxy fatty acid
amides of the formula (III),
R1
R-CO-N- [Z] (III)
where RCO is an aliphatic acyl radical having 6 to 22
carbon atoms, R1 is hydrogen or an alkyl or
hydroxyalkyl radical having 1 to 4 carbon atoms, and
[Z] is a linear or branched polyhydroxyalkyl radical
having 3 to 10 carbon atoms and from 3 to 10 hydroxyl
groups. The polyhydroxy fatty acid amides are known
substances which are customarily obtainable by
reductive amination of a reducing sugar with ammonia,
an alkylamine or an alkanolamine, and subsequent
acylation with a fatty acid, a fatty acid alkyl ester
or a fatty acid chloride.
CA 02313356 2000-07-04
49
The group of the polyhydroxy fatty acid amides also
includes compounds of the formula (IV)
R1-O-R2
R-CO-N- [Z] (IV)
where R is a linear or branched alkyl or alkenyl
radical having 7 to 12 carbon atoms, Rl is a linear,
branched or cyclic alkyl radical or an aryl radical
having 2 to 8 carbon atoms and RZ is a linear, branched
or cyclic alkyl radical or an aryl radical or an
oxyalkyl radical having 1 to 8 carbon atoms, preference
being given to C1_4 alkyl radicals or phenyl radicals,
and [Z] is a linear polyhydroxyalkyl radical whose
alkyl chain is substituted by at least two hydroxyl
groups, or alkoxylated, preferably ethoxylated or
propoxylated, derivatives of said radical.
[Z] is preferably obtained by reductive amination of a
reduced sugar, e.g., glucose, fructose, maltose,
lactose, galactose, mannose, or xylose. The N-alkoxy-
or N-aryloxy-substituted compounds may then be
converted to the desired polyhydroxy fatty acid amides,
for example, in accordance with the teaching of
International Patent Application WO-A-95/07331 by
reaction with fatty acid methyl esters in the presence
of an alkoxide as catalyst.
In the context of the present invention, preference is
given to producing laundry detergent and cleaning
product tablets comprising anionic and nonionic
surfactant(s); performance advantages may result from
certain proportions in which the individual classes of
surfactant are used.
CA 02313356 2000-07-04
For example, particular preference is given to laundry
detergent and cleaning product tablets in which the
ratio of anionic surfactants) to nonionic
surfactants) is between 10:1 and 1:10, preferably
5 between 7.5:1 and 1:5, and in particular between 5:1
and 1:2. Also preferred are laundry detergent and
cleaning product tablets comprising surfactant(s),
preferably anionic and/or nonionic surfactant(s), in
amounts of from 5 to 40% by weight, preferably from 7.5
10 to 35% by weight, with particular preference from 10 to
30% by weight, and in particular from 12.5 to 25% by
weight, based in each case on the tablet weight.
From a performance standpoint it may be advantageous if
15 certain classes of surfactant are absent from some
phases of the laundry detergent and cleaning product
tablets or from the tablet as a whole, i.e., from all
phases. A further important embodiment of the present
invention therefore envisages that at least one phase
20 of the tablets is free from nonionic surfactants.
Conversely, however, the presence of certain
surfactants in individual phases or in the whole
tablet, i.e., in all phases, may produce a positive
25 effect. The incorporation of the above-described alkyl
polyglycosides has been found advantageous, and so
preference is given to laundry detergent and cleaning
product tablets in which at least one phase of the
tablets comprises alkyl polyglycosides.
Similarly to the case with the nonionic surfactants,
the omission of anionic surfactants from certain phases
or all phases may also result in laundry detergent and
cleaning product tablets better suited to certain
fields of application. In the context of the present
invention, therefore, it is also possible to conceive
of laundry detergent and cleaning product tablets in
CA 02313356 2000-07-04
51
which at least one phase of the tablet is free from
anionic surfactants.
As already mentioned, the use of surfactants in the
case of cleaning product tablets for machine
dishwashing is preferably limited to the use of
nonionic surfactants in small amounts. Laundry
detergent and cleaning product tablets preferred for
use as cleaning product tablets in the context of the
present invention are those which have total surfactant
contents of less than 5% by weight, preferably less
than 4% by weight, with particular preference less than
3% by weight, and in particular less than 2% by weight,
based in each case on their total weight. Surfactants
used in machine dishwashing compositions are usually
only low-foaming nonionic surfactants. Representatives
from the groups of the anionic, cationic and amphoteric
surfactants, in contrast, are of relatively little
importance. V~lith particular preference, the cleaning
product tablets produced according to the invention for
machine dishwashing comprise nonionic surfactants,
especially nonionic surfactants from the group of the
alkoxylated alcohols. Preferred nonionic surfactants
used are alkoxylated, advantageously ethoxylated,
especially primary, alcohols having preferably 8 to 18
carbon atoms and on average from 1 to 12 mol of
ethylene oxide (EO) per mole of alcohol, in which the
alcohol radical may be linear or, preferably, methyl-
branched in position 2 and/or may contain a mixture of
linear and methyl-branched radicals, as are customarily
present in oxo alcohol radicals. Particular preference
is given, however, to alcohol ethoxylates having linear
radicals from alcohols of natural origin having 12 to
18 carbon atoms, e.g., from coconut, palm, tallow fatty
3 5 or oleyl alcohol , and having on average f rom 2 to 8 EO
per mole of alcohol. The preferred ethoxylated alcohols
include, for example, C12-14 alcohols having 3 EO or
4 EO, C9_11 alcohol having 7 EO, Cla-is alcohols having
CA 02313356 2000-07-04
52
3 EO, 5 EO, 7 EO or 8 EO, Clz-le alcohols having 3 EO,
EO or 7 EO, and mixtures of these, such as mixtures
Of C12-14 alcohol having 3 EO and Clz-la alcohol having
5 EO. The stated degrees of ethoxylation are
5 statistical means; which for a specific product may be
an integer or a fraction. Preferred alcohol ethoxylates
have a narrowed homolog distribution (narrow range
ethoxylates, NREs). In addition to these nonionic
surfactants, fatty alcohols having more than 12 EO may
also be used. Examples thereof are tallow fatty alcohol
having 14 EO, 25 EO, 30 EO, or 40 EO.
Especially in connection with the production, in
accordance with the invention, of laundry detergent
tablets or cleaning product tablets for machine
dishwashing, it is preferred for the laundry detergent
and cleaning product tablets to comprise a nonionic
surfactant having a melting point above room
temperature. Accordingly, at least one of the
deformable masses in the process of the invention
preferably comprises a nonionic surfactant having a
melting point above 20°C. Nonionic surfactants whose
use is preferred have melting points above 25°C,
nonionic surfactants whose use is particularly
preferred have melting points of between 25 and 60°C,
in particular between 26.6 and 43.3°C.
Suitable nonionic surfactants having melting or
softening points within the stated temperature range
are, for example, low-foaming nonionic surfactants
which may be solid or highly viscous at room
temperature. If nonionic surfactants which are highly
viscous at room temperature are used, then it is
preferred that they have a viscosity above 20 Pas,
preferably above 35 Pas, and in particular above
Pas. Also preferred are nonionic surfactants which
possess a waxlike consistency at room temperature.
CA 02313356 2000-07-04
53
Preferred nonionic surfactants for use that are solid
at room temperature originate from the groups of
alkoxylated nonionic surfactants, especially the
ethoxylated primary alcohols, and mixtures of these
surfactants with surfactants of more complex
construction such as polyoxypropylene/polyoxyethylene/
polyoxypropylene (PO/EO/PO) surfactants. Such
(PO/EO/PO) nonionic surfactants are notable,
furthermore, for good foam control.
In one preferred embodiment of the present invention,
the nonionic surfactant having a melting point above
room temperature is an ethoxylated nonionic surfactant
originating from the reaction of a monohydroxy alkanol
or alkylphenol having 6 to 20 carbon atoms with
preferably at least 12 mol, with particular preference
at least 15 mol, in particular at least 20 mol, of
ethylene oxide per mole of alcohol or alkylphenol,
respectively.
A particularly preferred nonionic surfactant for use
that is solid at room temperature is obtained from a
straight-chain fatty alcohol having 16 to 20 carbon
atoms (Cls-zo alcohol) , preferably a C18 alcohol, and at
least 12 mol, preferably at least 15 mol, and in
particular at least 20 mol of ethylene oxide. Of these,
the so-called "narrow range ethoxylates" (see above)
are particularly preferred.
The nonionic surfactant which is solid at room
temperature preferably further possesses propylene
oxide units in the molecule. Preferably, such PO units
account for up to 25% by weight, with particular
preference up to 20% by weight, and in particular up to
15% by weight, of the overall molar mass of the
nonionic surfactant. Particularly preferred nonionic
surfactants are ethoxylated monohydroxy alkanols or
alkylphenols, which additionally comprise
CA 02313356 2000-07-04
54
polyoxyethylene-polyoxypropylene block copolymer units.
The alcohol or alkylphenol moiety of such nonionic
surfactant molecules in this case makes up preferably
more than 30% by weight, with particular preference
more than 50% by weight, and in particular more than
70% by weight, of the overall molar mass of such
nonionic surfactants.
Further nonionic surfactants whose use is particularly
preferred, have melting points above room temperature,
contain from 40 to 70% of a polyoxypropylene/
polyoxyethylene/polyoxypropylene block polymer blend
which comprises 75% by weight of an inverted block
copolymer of polyoxyethylene and polyoxypropylene
containing 17 mol of ethylene oxide and 44 mol of
propylene oxide and 25% by weight of a block copolymer
of polyoxyethylene and polyoxypropylene, initiated with
trimethylolpropane and containing 24 mol of ethylene
oxide and 99 mol of propylene oxide per mole of
trimethylolpropane.
30
Nonionic surfactants which may be used with particular
preference are, for example, obtainable under the name
Poly Tergent~ SLF-18 from the company Olin Chemicals.
A further preferred surfactant may be described by the
formula
R10 [CHzCH (CH3) O] X [CHZCH20] y [CHZCH (OH) RZ]
in which R1 is a linear or branched aliphatic
hydrocarbon radical having 4 to 18 carbon atoms, or
mixtures thereof, RZ is a linear or branched
hydrocarbon radical having 2 to 26 carbon atoms, or
mixtures thereof, and x is between 0.5 and 1.5, and y
is at least 15.
CA 02313356 2000-07-04
Further nonionic surfactants which may be used with
preference are the endgroup-capped poly(oxyalkylated)
nonionic surfactants of the formula
5 R10 [CHZCH (R3) O] X [CHz] kCH (OH) [CHZ] ~OR2
in which R1 and R2 are linear or branched, saturated or
unsaturated, aliphatic or aromatic hydrocarbon radicals
having 1 to 30 carbon atoms, R3 is H or a methyl,
10 ethyl, n-propyl, isopropyl, n-butyl, 2-butyl or 2-
methyl -2 -butyl radical , x i s between 1 and 3 0 , k and j
are between 1 and 12, preferably between 1 and 5. Where
x >_ 2, each R3 in the above formula may be different. R1
and R2 are preferably linear or branched, saturated or
15 unsaturated, aliphatic or aromatic hydrocarbon radicals
having 6 to 22 carbon atoms, radicals having 8 to 18
carbon atoms being particularly preferred. For the
radical R3, H, -CH3 or -CHzCH3 are particularly
preferred. Particularly preferred values for x lie
20 within the range from 1 to 20, in particular from 6 to
15.
As described above, each R3 in the above formula may be
different if x >_ 2. By this means it is possible to
25 vary the alkylene oxide unit in the square brackets. If
x, for example, is 3, the radical R3 may be selected in
order to form ethylene oxide (R3 - H), or propylene
oxide (R3 - CH3) units, which may be added on to one
another in any sequence, examples being (EO)(PO)(EO),
30 (EO) (EO) (PO) , (EO) (EO) (EO) , (PO) (EO) (PO) , (PO) (PO) (EO)
and (PO) (PO) (PO) . The value of 3 for x has been chosen
by way of example in this case and it is entirely
possible for it to be larger, the scope for variation
increasing as the values of x go up and embracing, for
35 example, a large number of (EO) groups, combined with a
small number of (PO) groups, or vice versa.
CA 02313356 2000-07-04
56
Particularly preferred endgroup-capped poly(oxy-
alkylated) alcohols of the above formula have values of
k = 1 and j - 1, thereby simplifying the above formula
to
R10 [CHzCH (R3) O] XCHZCH (OH) CH20R2 .
In the last-mentioned formula, Rl, RZ and R3 are as
defined above and x stands for numbers from 1 to 30,
preferably from 1 to 20, and in particular from 6 to
18. Particular preference is given to surfactants
wherein the radicals R1 and R2 have 9 to 14 carbon
atoms, R3 is H, and x adopts values from 6 to 15.
The remarks above refer in part to the process end
products, which - as mentioned earlier on - may also be
in the form of two-, three- or four-phase
configurations. Based on the individual mass for
processing, which comprises surfactant(s), preference
in connection with the production of cleaning product
tablets for machine dishwashing is given to processes
wherein the deformable masses) has (have) total
surfactant contents of less than 5~ by weight,
preferably less than 4~ by weight, with particular
preference less than 3~ by weight, and in particular
less than 2% by weight, based in each case on the mass.
In addition to the abovementioned constituents, builder
and surfactant, the laundry detergent and cleaning
product tablets of the invention may comprise further
customary laundry detergent and cleaning product
ingredients from the group consisting of bleaches,
bleach activators, disintegration aids, dyes,
fragrances, optical brighteners, enzymes, foam
inhibitors, silicone oils, antiredeposition agents,
graying inhibitors, color transfer inhibitors, and
corrosion inhibitors. These substances may be used in
all of the masses for processing, although it is also
CA 02313356 2000-07-04
57
possible to make use of advantageous properties by
virtue of the separation of certain ingredients.
In order to facilitate the disintegration of highly
compacted tablets, it is possible to incorporate
disintegration aids, known as tablet disintegrants,
into the tablets in order to reduce the disintegration
times. These substances are suitable, for example, for
accelerating the release of individual tablet regions
relative to other regions. In the process of the
invention, this may be realized in that only one of the
masses for processing comprises such substances, or in
that two or more masses comprise such substances in
different amounts. Tablet disintegrants, or
disintegration accelerators, are understood in
accordance with Rompp (9th Edition, Vol. 6, p. 4440)
and Voigt "Lehrbuch der pharmazeutischen Technologie"
[Textbook of pharmaceutical technology] (6th Edition,
1987, pp. 182-184) to be auxiliaries which ensure the
rapid disintegration of tablets in water or gastric
fluid and the release of the drugs in absorbable form.
These substances increase in volume on ingress of
water, with on the one hand an increase in the
intrinsic volume (swelling) and on the other hand, by
way of the release of gases as well, the possiblity of
generating a pressure which causes the tablets to
disintegrate into smaller particles. Examples of
established disintegration aids are carbonate/citric
acid systems, with the use of other organic acids also
being possible. Examples of swelling disintegration
aids are synthetic polymers such as
polyvinylpyrrolidone (PVP) or natural polymers and/or
modified natural substances such as cellulose and
starch and their derivatives, alginates, or casein
derivatives.
CA 02313356 2000-07-04
58
Preferred laundry detergent and cleaning product
tablets contain from 0.5 to 10% by weight, preferably
from 3 to 7% by weight, and in particular from 4 to 6%
by weight, of one or more disintegration aids, based in
each case on the tablet weight. If only one mass
comprises disintegration aids, then these figures are
based only on the weight of that mass.
Preferred disintegrants used in the context of the
present invention are cellulose-based disintegrants and
so preferred laundry detergent and cleaning product
tablets comprise a cellulose-based disintegrant of this
kind in amounts from 0.5 to 10% by weight, preferably
from 3 to 7% by weight, and in particular from 4 to 6%
by weight. Pure cellulose has the formal empirical
composition (C6HloOs) n and, considered formally, is a
~i-1,4-polyacetal of cellobiose, which itself is
constructed of two molecules of glucose. Suitable
celluloses consist of from about 500 to 5000 glucose
units and, accordingly, have average molecular masses
of from 50,000 to 500,000. Cellulose-based
disintegrants which can be used also include, in the
context of the present invention, cellulose derivatives
obtainable by polymer-analogous reactions from
cellulose. Such chemically modified celluloses include,
for example, products of esterifications and
etherifications in which hydroxy hydrogen atoms have
been substituted. However, celluloses in which the
hydroxy groups have been replaced by functional groups
not attached by an oxygen atom may also be used as
cellulose derivatives. The group of the cellulose
derivatives embraces, for example, alkali metal
celluloses, carboxymethylcellulose (CMC), cellulose
esters and cellulose ethers and aminocelluloses. Said
cellulose derivatives are preferably not used alone as
cellulose-based disintegrants but instead are used in a
mixture with cellulose. The cellulose derivative
content of these mixtures is preferably less than 50%
CA 02313356 2000-07-04
59
by weight, with particular preference less than 20% by
weight, based on the cellulose-based disintegrant. The
particularly preferred cellulose-based disintegrant
used is pure cellulose, free from cellulose
derivatives.
The cellulose used as disintegration aid is preferably
not used in finely divided form but instead is
converted into a coarser form, for example, by
granulation or compaction, before being admixed to the
premixes intended for compression. Laundry detergent
and cleaning product tablets comprising disintegrants
in granular or optionally cogranulated form are
described in German Patent Applications
DE 197 09 991 (Stefan Herzog) and DE 197 10 254
(Henkel) and in International Patent Application
W098/40463 (Henkel). These documents also provide
further details on the production of granulated,
compacted or cogranulated cellulose disintegrants. The
particle sizes of such disintegrants are usually above
200 Vim, preferably between 300 and 1600 ~m to the
extent of at least 90~, and in particular between 400
and 1200 ~m to the extent of at least 90~. The
abovementioned, relatively coarse disintegration aids,
and those described in more detail in the cited
documents, are preferred for use as disintegration aids
in the context of the present invention and are
available commercially, for example, under the
designation Arbocel~ TF-30-HG from the company
Rettenmaier.
As a further cellulose-based disintegrant or as a
constituent of this component it is possible to use
microcrystalline cellulose. This microcrystalline
cellulose is obtained by partial hydrolysis of
celluloses under conditions which attack only the
amorphous regions (approximately 30% of the total
cellulose mass) of the celluloses and break them up
CA 02313356 2000-07-04
completely but leave the crystalline regions
(approximately 70%) intact. Subsequent deaggregation of
the microfine celluloses resulting from the hydrolysis
yields the microcrystalline celluloses, which have
5 primary particle sizes of approximately 5 ~m and can be
compacted, for example, to granules having an average
particle size of 200 Vim.
Laundry detergent and cleaning product tablets which
10 are preferred in the context of the present invention
further comprise a disintegration aid, preferably a
cellulose-based disintegration aid, preferably in
granular, cogranulated or compacted form, in amounts of
from 0.5 to 10% by weight, preferably from 3 to 7% by
15 weight, and in particular from 4 to 6% by weight, based
in each case on the tablet weight.
The laundry detergent and cleaning product tablets of
the invention may further comprise, incorporated into
20 one or more of the masses for processing; a gas-
evolving effervescent system. Said gas-evolving
effervescent system may consist of a single substance
which on contact with water releases a gas. Among these
compounds mention may be made, in particular, of
25 magnesium peroxide, which on contact with water
releases oxygen. Normally, however, the gas-releasing
effervescent system consists in its turn of at least
two constituents which react with one another and, in
so doing, form gas. Although a multitude of systems
30 which release, for example, nitrogen, oxygen or
hydrogen are conceivable and implementable here, the
effervescent system used in the laundry detergent and
cleaning product tablets of the invention will be
selectable on the basis of both economic and
35 environmental considerations. Preferred effervescent
systems consist of alkali metal carbonate and/or alkali
metal hydrogen carbonate and of an acidifier apt to
CA 02313356 2000-07-04
61
release carbon dioxide from the alkali metal salts in
aqueous solution.
Among the alkali metal carbonates and/or alkali metal
hydrogen carbonates, the sodium and potassium salts are
much preferred over the other salts on grounds of cost.
It is of course not mandatory to use the single alkali
metal carbonates or alkali metal hydrogen carbonates in
question; rather, mixtures of different carbonates and
hydrogen carbonates may be preferred from the
standpoint of wash technology.
In preferred laundry detergent and cleaning product
tablets, the effervescent system used comprises from 2
to 20% by weight, preferably from 3 to 15% by weight,
and in particular from 5 to 10% by weight, of an alkali
metal carbonate or alkali metal hydrogen carbonate, and
from 1 to 15, preferably from 2 to 12, and in
particular from 3 to 10, % by weight of an acidifier,
based in each case on the total tablet. The amount of
said substances in individual masses may very well be
higher.
As examples of acidifiers which release carbon dioxide
from the alkali metal salts in aqueous solution it is
possible to use boric acid and also alkali metal
hydrogen sulfates, alkali metal hydrogen phosphates,
and other inorganic salts. Preference is given,
however, to the use of organic acidifiers, with citric
acid being a particularly preferred acidifier. However,
it is also possible, in particular, to use the other
solid mono-, oligo- and polycarboxylic acids. Preferred
among this group, in turn, are tartaric acid, succinic
acid, malonic acid, adipic acid, malefic acid, fumaric
acid, oxalic acid, and polyacrylic acid. Organic
sulfonic acids such as amidosulfonic acid may likewise
be used. A commercially available acidifier which is
likewise preferred for use in the context of the
CA 02313356 2000-07-04
62
present invention is Sokalan~ DCS (trademark of BASF),
a mixture of succinic acid (max. 31~ by weight),
glutaric acid (max. 50~ by weight), and adipic acid
(max. 33~ by weight).
In the context of the present invention, preference is
given to laundry detergent and cleaning product tablets
where the acidifier used in the effervescent system
comprises a substance from the group of the organic
di-, tri- and oligocarboxylic acids, and mixtures
thereof .
In processes which are preferred in the context of the
present invention, at least one of the deformable
masses comprises bleaches from the group of the oxygen
or halogen bleaches, especially the chlorine bleaches,
with particular preference to sodium perborate and
sodium percarbonate, in amounts of from 2 to 25~ by
weight, preferably from 5 to 20~ by weight, and in
particular from 10 to 15~ by weight, based in each case
on the mass. These substances are described below.
Among the compounds used as bleaches which yield H202 in
water, particular importance is possessed by sodium
percarbonate. This "sodium percarbonate" is a term used
unspecifically for sodium carbonate peroxohydrates,
which strictly speaking are not "percarbonates" (i.e.,
salts of percarbonic acid) but rather hydrogen peroxide
adducts onto sodium carbonate. The commercial product
has the average composition 2 Na2C03 ~ 3 H202 and is thus
not a peroxycarbonate. Sodium percarbonate forms a
white, water soluble powder of density 2.14 g cm-3 which
breaks down readily into sodium carbonate and oxygen
having a bleaching or oxidizing action.
Sodium carbonate peroxohydrate was first obtained in
1899 by precipitation with ethanol from a solution of
sodium carbonate in hydrogen peroxide, but was
CA 02313356 2000-07-04
63
mistakenly regarded as a peroxycarbonate. Only in 1909
was the compound recognized as the hydrogen peroxide
addition compound; nevertheless, the historical name
(sodium percarbonate) has persisted in the art.
Industrially, sodium percarbonate is produced
predominantly by precipitation from aqueous solution
(known as the wet process). In this process, aqueous
solutions of sodium carbonate and hydrogen peroxide are
combined and the sodium percarbonate is precipitated by
means of salting agents (predominantly sodium
chloride), crystallizing aids (for example poly-
phosphates, polyacrylates), and stabilizers (for
example, Mg2+ ions). The precipitated salt, which still
contains from 5 to 12% by weight of the mother liquor,
is subsequently centrifuged and dried in fluidized-bed
driers at 90°C. The bulk density of the finished
product may vary between 800 and 1200 g/1 according to
the production process. Generally, the percarbonate is
stabilized by an additional coating. Coating processes,
and substances used for the coating, are amply
described in the patent literature. Fundamentally, it
is possible in accordance with the invention to use all
commercially customary percarbonate types, as supplied,
for example, by the companies Solway Interox, Degussa,
Kemira or Akzo.
Further bleaches which may be used are, for example,
sodium perborate tetrahydrate and sodium perborate
monohydrate, peroxypyrophosphates, citrate perhydrates,
and Hz02-donating peracidic salts or peracids, such as
perbenzoates, peroxophthalates, diperazelaic acid,
phthaloimino peracid or diperdodecanedioic acid. With
the use of the bleaches, as well, it is possible to
refrain from the use of surfactants and/or builders,
thereby making it possible to produce straight bleach
tablets. If such tablets are to be used for bleaching
textile laundry, preference is given to a combination
CA 02313356 2000-07-04
64
of sodium percarbonate with sodium sesquicarbonate,
irrespective of what other ingredients are present in
the tablets. If cleaning product tablets or bleach
tablets for machine dishwashing are being produced,
then the bleaches used may also comprise bleaches from
the group of organic bleaches. Typical organic bleaches
are the diacyl peroxides, such as dibenzoyl peroxide,
for example. Further typical organic bleaches are the
peroxy acids, particular examples being the alkyl
peroxy acids and the aryl peroxy acids. Preferred
representatives are (a) peroxybenzoic acid and its
ring-substituted derivatives, such as alkylperoxy-
benzoic acids, and also peroxy-a-naphthoic acid and
magnesium monoperphthalate, (b) aliphatic or
substituted aliphatic peroxy acids, such as
peroxylauric acid, peroxystearic acid, E-phthalimido-
peroxy caproic acid [phthaloiminoperoxyhexanoic acid
(PAP)], o-carboxybenzamidoperoxycaproic acid, N-
nonenylamidoperadipic acid and N-nonenylamido-
persuccinates, and (c) aliphatic and araliphatic peroxy
dicarboxylic acids, such as 1,12-diperoxydecane-
dicarboxylic acid, 1,9-diperoxyazelaic acid, diperoxy-
sebacic acid, diperoxybrassylic acid, the diperoxy-
phthalic acids, 2-decyldiperoxybutane-1,4-dioic acid
and N,N-terephthaloyldi(6-aminopercaproic acid) may be
used.
Bleaches in tablets for machine dishwashing may also be
substances which release chlorine or bromine. Among
suitable chlorine- or bromine-releasing materials,
examples include heterocyclic N-bromoamides and N-
chloroamides, examples being trichloroisocyanuric acid,
tribromoisocyanuric acid, dibromoisocyanuric acid
and/or dichloroisocyanuric acid (DICA) and/or salts
thereof with cations such as potassium and sodium.
Hydantoin compounds, such as 1,3-dichloro-5,5-
dimethylhydantoin, are likewise suitable.
CA 02313356 2000-07-04
In processes which are further preferred in accordance
with the invention, at least one of the deformable
masses comprises bleach activators from the groups of
polyacylated alkylenediamines, especially tetraacetyl-
5 ethylenediamine (TAED), N-acyl imides, especially N-
nonanoylsuccinimide (NOSI), acylated phenolsulfonates,
especially n-nonanoyl- or
isononanoyloxybenzenesulfonate (n- or iso-NOBS) and N-
methylmorpholiniumacetonitrile methyl sulfate (MMA), in
10 amounts of from 0.25 to 15% by weight, preferably from
0.5 to 10% by weight, and in particular from 1 to 5% by
weight, based in each case on the mass. These
substances too are described below.
15 In order to achieve an improved bleaching effect when
washing or cleaning at temperatures of 60°C and below,
it is possible to incorporate bleach activators. Bleach
activators, which boost the action of the bleaches, are
for example, compounds containing one or more N-acyl
20 and/or O-acyl groups, such as substances from the class
of the anhydrides, esters, imides and acylated
imidazoles or oximes. Examples are tetraacetyl-
ethylenediamine (TAED), tetraacetylmethylene-diamine
(TAMD), and tetraacetylhexylenediamine (TAHD), and also
25 pentaacetylglucose (PAG), 1,5-diacetyl-2,2-
dioxohexahydro-1,3,5-triazine (DADHT), and isatoic
anhydride ( ISA) .
Bleach activators which may be used are compounds which
30 under perhydrolysis conditions give rise to aliphatic
peroxo carboxylic acids having preferably 1 to 10
carbon atoms, in particular 2 to 4 carbon atoms, and/or
substituted or unsubstituted perbenzoic acid. Suitable
substances are those which carry O-acyl and/or N-acyl
35 groups of the stated number of carbon atoms, and/or
substituted or unsubstituted benzoyl groups. Preference
is given to polyacylated alkylenediamines, especially
tetraacetylethylenediamine (TAED), acylated triazine
CA 02313356 2000-07-04
66
derivatives, especially 1,5-diacetyl-2,4-dioxohexa-
hydro-1,3,5-triazine (DADHT), acylated glycolurils,
especially tetraacetylglycoluril (TAGU), N-acyl imides,
especially N-nonanoylsuccinimide (NOSI), acylated
phenolsulfonates, especially n-nonanoyl- or iso-
nonanoyloxybenzenesulfonate (n- or iso-NOBS),
carboxylic anhydrides, especially phthalic anhydride,
acylated polyhydric alcohols, especially triacetin,
ethylene glycol diacetate, 2,5-diacetoxy-2,5-dihydro-
furan, N-methylmorpholiniumacetonitrile methyl sulfate
(MMA), and the enol esters known from German Patent
Applications DE 196 16 693 and DE 196 16 767, and also
acetylated sorbitol and mannitol and/or mixtures
thereof (SORMAN), acylated sugar derivatives,
especially pentaacetylglucose (PAG), pentaacetyl-
fructose, tetraacetylxylose and octaacetyllactose, and
acetylated, optionally N-alkylated glucamine and
gluconolactone, and/or N-acylated lactams, for example,
N-benzoylcaprolactam. Hydrophilically substituted
acylacetals and acyllactams are likewise used with
preference. Combinations of conventional bleach
activators may also be used.
In addition to the conventional bleach activators, or
instead of them, it is also possible to incorporate
what are known as bleaching catalysts into the rinse
aid particles. These substances are bleach-boosting
transition metal salts or transition metal complexes
such as, for example, Mn-, Fe-, Co-, Ru- or Mo-salen
complexes or -carbonyl complexes. Other bleaching
catalysts which can be used include Mn, Fe, Co, Ru, Mo,
Ti, V and Cu complexes with N-containing tripod
ligands, and also Co-, Fe-, Cu- and Ru-ammine
complexes.
Preference is given to the use of bleach activators
from the group of polyacylated alkylenediamines,
especially tetraacetylethylenediamine (TAED), N-acyl
CA 02313356 2000-07-04
67
imides, especially N-nonanoylsuccinimide (NOSI),
acylated phenolsulfonates, especially n-nonanoyl- or
isononanoyloxybenzenesulfonate (n- or iso-NOBS), N-
methylmorpholiniumacetonitrile methyl sulfate (MMA),
preferably in amounts of up to 10% by weight, in
particular from 0.1% by weight to 8% by weight, more
particularly from 2 to 8% by weight, and with
particular preference from 2 to 6% by weight, based on
the overall composition.
Bleach-boosting transition metal complexes, especially
those with the central atoms Mn, Fe, Co, Cu, Mo, V, Ti
and/or Ru, preferably selected from the group of
manganese and/or cobalt salts and/or complexes, with
particular preference from cobalt ammine complexes,
cobalt acetato complexes, cobalt carbonyl complexes,
the chlorides of cobalt or manganese, and manganese
sulfate, are used in customary amounts, preferably in
an amount of up to 5% by weight, in particular from
0.0025% by weight to 1% by weight, and with particular
preference from 0.01% by weight to 0.25% by weight,
based in each case on the overall composition. In
specific cases, however, it is also possible to use a
greater amount of bleach activator.
Owing to their oxidizing action it is advantageous to
separate the bleaches from other ingredients, this
purpose being suitably met in particular by processes
of the invention for producing multiphase tablets.
Processes wherein one of the deformable masses
comprises bleaches while another deformable mass
comprises bleach activators are preferred.
A further preferred process is one wherein at least one
of the deformable masses comprises silver protectants
from the group of the triazoles, benzotriazoles,
bisbenzotriazoles, aminotriazoles, alkylaminotriazoles
and the transition metal salts or transition metal
CA 02313356 2000-07-04
68
complexes, with particular preference benzotriazole
and/or alkylaminotriazole, in amounts of from 0.01 to
5~ by weight, preferably from 0.05 to 4~ by weight, and
in particular from 0.5 to 3~ by weight, based in each
case on the mass.
Said corrosion inhibitors may likewise be incorporated
into the masses for processing in order to protect the
ware or the machine, with special importance in the
field of machine dishwashing being possessed, in
particular, by silver protectants. The known substances
of the prior art may be used. In general it is possible
to use, in particular, silver protectants selected from
the group consisting of triazoles, benzotriazoles,
bisbenzotriazoles, aminotriazoles, alkylaminotriazoles,
and transition metal salts or transition metal
complexes. Particular preference is given to the use of
benzotriazole and/or alkylaminotriazole. Frequently
encountered in cleaning formulations, furthermore, are
agent's containing active chlorine, which may
significantly reduce corrosion of the silver surface.
In chlorine-free cleaners, use is made in particular of
oxygen-containing and nitrogen-containing organic
redox-active compounds, such as divalent and trivalent
phenols, e.g. hydroquinone, pyrocatechol,
hydroxyhydroquinone, gallic acid, phloroglucinol,
pyrogallol, and derivatives of these classes of
compound. Inorganic compounds in the form of salts and
complexes, such as salts of the metals Mn, Ti, Zr, Hf,
V, Co and Ce, also find frequent application.
Preference is given in this context to the transition
metal salts selected from the group consisting of
manganese and/or cobalt salts and/or complexes, with
particular preference cobalt ammine complexes, cobalt
acetato complexes, cobalt carbonyl complexes, the
chlorides of cobalt or of manganese and manganese
sulfate. Similarly, zinc compounds may be used to
prevent corrosion on the ware.
CA 02313356 2000-07-04
69
If corrosion inhibitors are used in multiphase tablets,
it is preferred to separate them from the bleaches.
Accordingly, processes wherein one of the deformable
masses comprises bleaches while another deformable mass
comprises corrosion inhibitors are preferred.
The separation of the bleaches from other ingredients
may also be advantageous. Process of the invention
wherein one of the deformable masses comprises bleaches
while another deformable mass comprises enzymes are
likewise preferred. Suitable enzymes include in
particular those from the classes of the hydrolases
such as the proteases, esterases, lipases or lipolytic
enzymes, amylases, cellulases or other glycosyl
hydrolases, and mixtures of said enzymes. In the
laundry, all of these hydrolases contribute to removing
stains, such as proteinaceous, fatty or starchy marks
and graying. Cellulases and other glycosyl hydrolases
may, furthermore, contribute, by removing pilling and
microfibrils, to the retention of color and to an
increase in the softness of the textile. For bleaching,
and/or for inhibiting color transfer it is also
possible to use oxidoreductases. Especially suitable
enzymatic active substances are those obtained from
bacterial strains or fungi such as Bacillus subtilis,
Bacillus licheniformis, Streptomyces griseus, Coprinus
cinereus and Humicola insolens, and also from
genetically modified variants thereof. Preference is
given to the use of proteases of the subtilisin type,
and especially to proteases obtained from Bacillus
lentus. Of particular interest in this context are
enzyme mixtures, examples being those of protease and
amylase or protease and lipase or lipolytic enzymes, or
protease and cellulase or of cellulase and lipase or
lipolytic enzymes of protease, amylase and lipase or
lipolytic enzymes, or protease, lipase or lipolytic
enzymes and cellulase, but especially protease and/or
CA 02313356 2000-07-04
lipase-containing mixtures or mixtures with lipolytic
enzymes. Examples of such lipolytic enzymes are the
known cutinases. Peroxidases or oxidases have also
proven suitable in some cases. The suitable amylases
5 include, in particular, alpha-amylases, iso-amylases,
pullulanases, and pectinases. Cellulases used are
preferably cellobiohydrolases, endoglucanases and
endoglucosidases, which are also called cellobiases,
and mixtures thereof. Because different types of
10 cellulase differ in their CMCase and Avicelase
activities, specific mixtures of the cellulases may be
used to establish the desired activities.
In cleaning product tablets for machine dishwashing,
15 naturally, different enzymes are used in order to take
account of the different substrates treated and
different types of soiling. Suitable enzymes here
include in particular those from the classes of the
hydrolases such as the proteases, esterases, lipases or
20 lipolytic enzymes, amylases, glycosyl hydrolases, and
mixtures of said enzymes. All of these hydrolases
contribute to removing stains, such as proteinaceous,
fatty or starchy marks. For bleaching, it is also
possible to use oxidoreductases. Especially suitable
25 enzymatic active substances are those obtained from
bacterial strains or fungi such as Bacillus subtilis,
Bacillus licheniformis, Streptomyces griseus, Coprinus
cinereus and Humicola insolens, and also from
genetically modified variants thereof. Preference is
30 given to the use of proteases of the subtilisin type,
and especially to proteases obtained from Bacillus
lentus. Of particular interest in this context are
enzyme mixtures, examples being those of protease and
amylase or protease and lipase or lipolytic enzymes, or
35 of protease, amylase and lipase or lipolytic enzymes,
or protease, lipase or lipolytic enzymes, but
especially protease and/or lipase-containing mixtures
or mixtures with lipolytic enzymes. Examples of such
CA 02313356 2000-07-04
71
lipolytic enzymes are the known cutinases. Peroxidases
or oxidases have also proven suitable in some cases.
The suitable amylases include, in particular, alpha-
amylases, iso-amylases, pullulanases, and pectinases.
The enzymes may be adsorbed on carrier substances or
embedded in sheathing substances in order to protect
them against premature decomposition. The proportion of
the enzymes, enzyme mixtures or enzyme granules may be,
for example, from about 0.1 to 5~ by weight, preferably
from 0.5 to about 4.5~s by weight, based in each case on
the mass (es) .
Irrespective of the intended application of the tablets
produced in accordance with the invention (for example,
laundry detergent tablets or cleaning product tablets),
preference is given to processes wherein one of the
material strands emerging from the emergence apertures
comprises enzymes.
Enzyme-containing masses of this kind are preferably
processed in multistrand processes; i.e., in addition
to a material strand comprising enzymes, there exists
at least one further strand which is preferably free
from enzymes. Here, particular preference is given to
processes wherein the enzyme-containing material strand
is enveloped by an enzyme-free material.
Separation of the bleaches from the surfactants
described earlier on above may also be advantageous, so
that preferred processes are those wherein one of the
deformable masses comprises bleaches while another
deformable mass comprises surfactants, preferably
nonionic surfactants, with particular preference
alkoxylated alcohols having 10 to 24 carbon atoms and
from 1 to 5 alkylene oxide units.
CA 02313356 2000-07-04
72
Further ingredients which may, in the context of the
process of the invention, be part of one or more masses
are, for example, cobuilders (see above), dyes, optical
brighteners, fragrances, soil release compounds, soil
repellents, antioxidants, fluorescence agents, foam
inhibitors, silicone fluids and/or liquid paraffins,
color transfer inhibitors, graying inhibitors,
detergency boosters, etc. These substances are
described below.
Organic builder substances which may be used are, for
example, the polycarboxylic acids, usable in the form
of their sodium salts, the term polycarboxylic acids
meaning those carboxylic acids which carry more than
one acid function. Examples of these are citric acid,
adipic acid, succinic acid, glutaric acid, malic acid,
tartaric acid, malefic acid, fumaric acid, sugar acids,
amino carboxylic acids, nitrilotriacetic acid (NTA),
provided such use is not objectionable on ecological
grounds, and also mixtures thereof. Preferred salts are
the salts of the polycarboxylic acids such as citric
acid, adipic acid, succinic acid, glutaric acid,
tartaric acid, sugar acids, and mixtures thereof.
The acids per se may also be used. In addition to their
builder effect, the acids typically also possess the
property of an acidifying component and thus also serve
to establish a lower and milder pH of laundry
detergents or cleaning products. In this context,
mention may be made in particular of citric acid,
succinic acid, glutaric acid, adipic acid, gluconic
acid, and any desired mixtures thereof.
Also suitable as builders are polymeric poly-
carboxylates; these are, for example, the alkali metal
salts of polyacrylic acid or of polymethacrylic acid,
examples being those having a relative molecular mass
of from 500 to 70,000 g/mol.
CA 02313356 2000-07-04
73
The molecular masses reported for polymeric poly-
carboxylates, for the purposes of this document, are
weight-average molecular masses, MW, of the respective
acid form, determined basically by means of gel
permeation chromatography (GPC) using a W detector.
The measurement was made against an external
polyacrylic acid standard, which owing to its
structural similarity to the polymers under
investigation provides realistic molecular weight
values. These figures differ markedly from the
molecular weight values obtained using poly-
styrenesulfonic acids as the standard. The molecular
masses measured against polystyrenesulfonic acids are
generally much higher than the molecular masses
reported in this document.
Suitable polymers are, in particular, polyacrylates,
which preferably have a molecular mass of from 2000 to
20,000 g/mol. Owing to their superior solubility,
preference in this group may be given in turn to the
short-chain polyacrylates, which have molecular masses
of from 2000 to 10,000 g/mol, and with particular
preference from 3000 to 5000 g/mol.
Also suitable are copolymeric polycarboxylates,
especially those of acrylic acid with methacrylic acid
and of acrylic acid or methacrylic acid with malefic
acid. Copolymers which have been found particularly
suitable are those of acrylic acid with malefic acid
which contain from 50 to 90~ by weight acrylic acid and
from 50 to 10~ by weight malefic acid. Their relative
molecular mass, based on free acids, is generally from
2000 to 70,000 g/mol, preferably from 20,000 to
50,000 g/mol, and in particular from 30,000 to
40,000 g/mol.
CA 02313356 2000-07-04
74
The (co)polymeric polycarboxylates can be used either
as powders or as aqueous solutions. The (co)polymeric
polycarboxylate content of the compositions is
preferably from 0.5 to 20~ by weight, in particular
from 3 to 10~ by weight.
In order to improve the solubility in water, the
polymers may also contain allylsulfonic acids, such as
allyloxybenzenesulfonic acid and methallylsulfonic
acid, for example, as monomers.
Particular preference is also given to biodegradable
polymers comprising more than two different monomer
units, examples being those comprising, as monomers,
salts of acrylic acid and of malefic acid, and also
vinyl alcohol or vinyl alcohol derivatives, or those
comprising, as monomers, salts of acrylic acid and of
2-alkylallylsulfonic acid, and also sugar derivatives.
Further preferred copolymers are those described in
German Patent Applications DE-A-43 03 320 and DE-A-44
17 734, whose monomers are preferably acrolein and
acrylic acid/acrylic acid salts, and, respectively,
acrolein and vinyl acetate.
Similarly, further preferred builder substances that
may be mentioned include polymeric amino dicarboxylic
acids, their salts or their precursor substances.
Particular preference is given to polyaspartic acids
and their salts and derivatives, which are disclosed in
German Patent Application DE-A-195 40 086 to have not
only cobuilder properties but also a bleach-stabilizing
action.
Further suitable builder substances are polyacetals,
which may be obtained by reacting dialdehydes with
polyol carboxylic acids having 5 to 7 carbon atoms and
at least 3 hydroxyl groups. Preferred polyacetals are
CA 02313356 2000-07-04
obtained from dialdehydes such as glyoxal,
glutaraldehyde, terephthalaldehyde and mixtures thereof
and from polyol carboxylic acids such as gluconic acid
and/or glucoheptonic acid.
5
Further suitable organic builder substances are
dextrins, examples being oligomers and polymers of
carbohydrates, which may be obtained by partial
hydrolysis of starches. The hydrolysis can be conducted
10 by customary processes; for example, acid-catalyzed or
enzyme-catalyzed processes. The hydrolysis products
preferably have average molecular masses in the range
from 400 to 500,000 g/mol. Preference is given here to
a polysaccharide having a dextrose equivalent (DE) in
15 the range from 0.5 to 40, in particular from 2 to 30,
DE being a common measure of the reducing effect of a
polysaccharide in comparison to dextrose, which
possesses a DE of 100. It is possible to use both
maltodextrins having a DE of between 3 and 20 and dried
20 glucose syrups having a DE of between 20 and 37, and
also so-called yellow dextrins and white dextrins
having higher molecular masses, in the range from 2000
to 30,000 g/mol.
25 The oxidized derivatives of such dextrins comprise
their products of reaction with oxidizing agents which
are able to oxidize at least one alcohol function of
the saccharide ring to the carboxylic acid function.
Oxidized dextrins of this kind, and processes for
30 preparing them, are known, for example, from European
Patent Applications EP-A-0 232 202, EP-A-0 427 349,
EP-A-0 472 042 and EP-A-0 542 496 and from
International Patent Applications ~n10 92/18542, WO
93/08251, H10 93/16110, WO 94/28030, WO 95/07303, WO
35 95/12619 and WO 95/20608. Likewise suitable is an
oxidized oligosaccharide in accordance with German
Patent Application DE-A-196 00 018. A product oxidized
CA 02313356 2000-07-04
76
at C6 of the saccharide ring may be particularly
advantageous.
Oxydisuccinates and other derivatives of disuccinates,
preferably ethylenediamine disuccinate, are further
suitable cobuilders. Ethylenediamine N,N'-disuccinate
(EDDS) is used preferably in the form of its sodium or
magnesium salts. Further preference in this context is
given to glycerol disuccinates and glycerol
trisuccinates as well. Suitable use amounts in
formulations containing zeolite and/or silicate are
from 3 to 15~ by weight.
Examples of further useful organic cobuilders are
acetylated hydroxy carboxylic acids and their salts,
which may also be present in lactone form and which
contain at least 4 carbon atoms, at least one hydroxyl
group, and not more than two acid groups. Such
cobuilders are described, for example, in International
Patent Application WO 95/20029.
A further class of substance having cobuilder
properties is represented by the phosphonates. The
phosphonates in question are, in particular,
hydroxyalkane- and aminoalkanephosphonates. Among the
hydroxyalkanephosphonates, 1-hydroxyethane-1,1-diphos-
phonate (HEDP) is of particular importance as a
cobuilder. It is used preferably as the sodium salt,
the disodium salt being neutral and the tetrasodium
salt giving an alkaline (pH 9) reaction. Suitable
aminoalkanephosphonates are preferably ethylenediamine-
tetramethylenephosphonate (EDTMP), diethylenetriamine-
pentamethylenephosphonate (DTPMP), and their higher
homologs. They are used preferably in the form of the
neutrally reacting sodium salts, e.g., as the
hexasodium salt of EDTMP or as the hepta- and octa-
sodium salt of DTPMP. As a builder in this case,
preference is given to using HEDP from the class of the
CA 02313356 2000-07-04
77
phosphonates. Furthermore, the aminoalkanephosphonates
possess a pronounced heavy metal binding capacity.
Accordingly, and especially if the compositions also
contain bleach, it may be preferred to use
aminoalkanephosphonates, especially DTPMP, or to use
mixtures of said phosphonates.
Furthermore, all compounds capable of forming complexes
with alkaline earth metal ions may be used as
cobuilders.
In order to enhance the esthetic appeal of the
detergent tablets of the invention, they may in whole
or in part be colored with appropriate dyes. Particular
optical effects may be achieved if, where tablets are
produced from two or more masses, the masses for
processing are differently colored. Preferred dyes,
whose selection presents no difficulty whatsoever to
the skilled worker, possess a high level of storage
stability and insensitivity to the other ingredients of
the compositions and to light and possess no pronounced
affinity for the substrates treated, such as textile
fibers or parts of kitchen- or tableware, so as not to
stain them.
Preference for use in the laundry detergent tablets of
the invention is given to all colorants which can be
oxidatively destroyed in the wash process, and to
mixtures thereof with suitable blue dyes, known as
bluing agents. It has proven advantageous to use
colorants which are soluble in water or at room
temperature in liquid organic substances. Examples of
suitable colorants are anionic colorants, e.g., anionic
nitroso dyes. One possible colorant is, for example,
naphthol green (Colour Index (CI) Part 1: Acid Green 1;
Part 2: 10020) which as a commercial product is
obtainable, for example, as Basacid° Green 970 from
BASF, Ludwigshafen, and also mixtures thereof with
CA 02313356 2000-07-04
78
suitable blue dyes. Further suitable colorants include
Pigmosol~ Blue 6900 (CI 74160), Pigmosol~ Green 8730
(CI 74260), Basonyl~ Red 545 FL (CI 45170), Sandolan°
Rhodamin EB400 (CI 45100), Basacid~ Yellow 094 (CI
47005), Sicovit~ Patent Blue 85 E 131 (CI 42051), Acid
Blue 183 (CAS 12217-22-0, CI Acid Blue 183), Pigment
Blue 15 (CI 74160), Supranol~ Blue GLW (CAS 12219-32-8,
CI Acid Blue 221), Nylosan~ Yellow N-7GL SGR (CAS
61814-57-1, CI Acid Yellow 218) and/or Sandolan° Blue
(CI Acid Blue 182, CAS 12219-26-0).
In the context of the choice of colorant it must be
ensured that the colorants do not have too great an
affinity for the textile surfaces, and especially for
synthetic fibers. At the same time, it should also be
borne in mind in choosing appropriate colorants that
colorants possess different stabilities with respect to
oxidation. The general rule is that water-insoluble
colorants are more stable to oxidation than water-
soluble colorants. Depending on the solubility and
hence also on the oxidation sensitivity, the
concentration of the colorant in the laundry detergents
and cleaning products varies. With readily water-
soluble colorants, e.g., the abovementioned Basacid°
Green, or the likewise abovementioned Sandolan° Blue,
color concentrations chosen are typically in the range
from a few 10-z to 10-3~s by weight. In the case of the
pigment dyes, which are particularly preferred for
reason of their brightness but are less readily soluble
in water, examples being the abovementioned Pigmosol°
dyes, the appropriate concentration of the colorant in
laundry detergents or cleaning products, in contrast,
is typically from a few 10-3 to 10-4~ by weight .
The laundry detergent and cleaning product tablets
produced by the process of the invention may comprise
one or more optical brighteners. These substances,
which are also called "whiteners", are used in modern
CA 02313356 2000-07-04
79
laundry detergents because even freshly washed and
bleached white laundry has a slight yellow cast.
Optical brighteners are organic dyes which convert a
part of the invisible W radiation of sunlight into
longer-wave blue light. The emission of this blue light
fills the "gap" in the light reflected by the textile,
so that a textile treated with optical brightener
appears whiter and lighter to the eye. Since the
mechanism of action of brighteners necessitates that
they go onto the fibers, a distinction is made in
accordance with the fibers to be "dyed" between, for
example, brighteners for cotton, nylon, or polyester
fibers. The commercially customary brighteners suitable
for incorporation into laundry detergents belong
primarily to five structural groups: the stilbene
group, the diphenylstilbene group, the coumarin-
quinoline group, the diphenylpyrazoline group, and the
group involving combination of benzoxazole or
benzimidazole with conjugated systems. An overview of
current brighteners can be found, for example, in G.
Jakobi, A. Ldhr, "Detergents and Textile Washing", VCH-
Verlag, Weinheim, 1987, pages 94 to 100. Examples of
suitable brighteners are salts of 4,4'-bis[(4-anilino-
6-morpholino-s-triazin-2-yl)amino]stilbene-2,2'-disul-
fonic acid or compounds of similar structure which
instead of the morphilino group carry a diethanolamino
group, a methylamino group, an anilino group, or a
2-methoxyethylamino group. Furthermore, brighteners of
the substituted diphenylstyryl type may be present,
examples being the alkali metal salts of 4,4'-bis(2-
sulfostyryl)biphenyl, 4,4'-bis(4-chloro-3-sulfostyryl)-
biphenyl, or 4-(4-chlorostyryl)-4'-(2-sulfostyryl)-
biphenyl. Mixtures of the abovementioned brighteners
may also be used.
Fragrances are added to the compositions of the
invention in order to enhance the esthetic appeal of
the products which are formed and to provide the
CA 02313356 2000-07-04
consumer with not only the performance but also a
visually and sensorially "typical and unmistakeable"
product. As perfume oils and/or fragrances it is
possible to use individual odorant compounds, examples
5 being the synthetic products of the ester, ether,
aldehyde, ketone, alcohol, and hydrocarbon types.
Odorant compounds of the ester type are, for example,
benzyl acetate, phenoxyethyl isobutyrate, p-tert-butyl-
cyclohexyl acetate, linalyl acetate, dimethyl-
10 benzylcarbinyl acetate, phenylethyl acetate, linalyl
benzoate, benzyl formate, ethyl methylphenylglycinate,
allyl cyclo-hexylpropionate, styrallyl propionate, and
benzyl salicylate. The ethers include, for example,
benzyl ethyl ether; the aldehydes include, for example,
15 the linear alkanals having 8-18 carbon atoms, citral,
citronellal, citronellyloxyacetaldehyde, cyclamen
aldehyde, hydroxycitronellal, lilial and bourgeonal;
the ketones include, for example, the ionones,
a-isomethylionone and methyl cedryl ketone; the
20 alcohols include anethole, citronellol, eugenol,
geraniol, linalool, phenylethyl alcohol, and terpineol;
the hydrocarbons include primarily the terpenes such as
limonene and pinene. Preference, however, is given to
the use of mixtures of different odorants, which
25 together produce an appealing fragrance note. Such
perfume oils may also contain natural odorant mixtures,
as obtainable from plant sources, examples being pine
oil, citrus oil, jasmine oil, patchouli oil, rose oil
or ylang-ylang oil. Likewise suitable are clary sage
30 oil, camomile oil, clove oil, balm oil, mint oil,
cinnamon leaf oil, lime blossom oil, juniperberry oil,
vetiver oil, olibanum oil, galbanum oil and labdanum
oil, and also orange blossom oil, neroliol, orange peel
oil, and sandalwood oil.
The fragrance content of the laundry detergent and
cleaning product tablets prepared in accordance with
the invention is usually up to 2~ by weight of the
CA 02313356 2000-07-04
81
overall formulation. The fragrances may be incorporated
directly into the compositions of the invention;
alternatively, it may be advantageous to apply the
fragrances to carriers which intensify the adhesion of
the perfume on the laundry and, by means of slower
fragrance release, ensure long-lasting fragrance of the
textiles. Materials which have become established as
such carriers are, for example, cyclodextrins, it being
possible in addition for the cyclodextrin-perfume
complexes to be additionally coated with further
auxiliaries.
In addition, the laundry detergent and cleaning product
tablets may also comprise components which have a
positive influence on the ease with which oil and
grease are washed off from textiles (these components
being known as soil repellents). This effect becomes
particularly marked when a textile is soiled that has
already been laundered previously a number of times
with a detergent of the invention comprising this oil-
and fat-dissolving component. The preferred oil- and
fat-dissolving components include, for example,
nonionic cellulose ethers such as methylcellulose and
methylhydroxypropylcellulose having a methoxy group
content of from 15 to 30% by weight and a hydroxypropyl
group content of from 1 to 15% by weight, based in each
case on the nonionic cellulose ether, and also the
prior art polymers of phthalic acid and/or terephthalic
acid, and/or derivatives thereof, especially polymers
of ethylene terephthalates and/or polyethylene glycol
terephthalates or anionically and/or nonionically
modified derivatives thereof. Of these, particular
preference is given to the sulfonated derivatives of
phthalic acid polymers and of terephthalic acid
polymers.
Foam inhibitors which may be used in the compositions
produced in accordance with the invention are suitably,
CA 02313356 2000-07-04
82
for example, soaps, paraffins or silicone oils, which
may if desired have been applied to carrier materials.
Graying inhibitors have the function of keeping the
dirt detached from the fiber in suspension in the
liquor and so preventing the redeposition of the dirt.
Suitable for this purpose are water-soluble colloids,
usually organic in nature, examples being the water-
soluble salts of polymeric carboxylic acids, glue,
gelatin, salts of ethersulfonic acids of starch or of
cellulose, or salts of acidic sulfuric esters of
cellulose or of starch. Water-soluble polyamides
containing acidic groups are also suitable for this
purpose. Furthermore, soluble starch preparations and
starch products other than those mentioned above may be
used, examples being degraded starch, aldehyde
starches, etc. Polyvinylpyrrolidone may also be used.
Preference, however, is given to the use of cellulose
ethers such as carboxymethylcellulose (Na salt),
methylcellulose, hydroxyalkylcellulose, and mixed
ethers such as methylhydroxyethylcellulose, methyl-
hydroxypropylcellulose, methylcarboxymethylcellulose
and mixtures thereof in amounts of from 0.1 to 5% by
weight, based on the compositions.
Since sheetlike textile structures, especially those of
filament rayon, viscose rayon, cotton and blends
thereof, may tend to crease, because the individual
fibers are susceptible to bending, buckling,
compressing and pinching transverse to the fiber
direction, the compositions produced in accordance with
the invention may comprise synthetic crease control
agents. These include, for example, synthetic products
based on fatty acids, fatty acid esters, fatty acid
amides, fatty acid alkylol esters, fatty acid
alkylolamides, or fatty alcohols, which are usually
reacted with ethylene oxide, or else products based on
lecithin or on modified phosphoric esters.
CA 02313356 2000-07-04
83
In order to combat microorganisms, the compositions
produced in accordance with the invention may comprise
antimicrobial active substances. In this context a
distinction is made, depending on antimicrobial
spectrum and mechanism of action, between bacteriostats
and bactericides, fungiostats and fungicides, etc.
Examples of important substances from these groups are
benzalkonium chlorides, alkylarylsulfonates, halo-
phenols, and phenylmercuric acetate, it also being
possible to do without these compounds entirely.
In order to prevent unwanted changes to the
compositions and/or the treated textiles as a result of
oxygen exposure and other oxidative processes, the
compositions may comprise antioxidants. This class of
compound includes, for example, substituted phenols,
hydroquinones, pyrocatechols and aromatic amines, and
also organic sulfides, polysulfides, dithiocarbamates,
phosphates, and phosphonates.
Increased wear comfort may result from the additional
use of antistats which are further added to the
compositions produced in accordance with the invention.
Antistats increase the surface conductivity and thus
enable better dissipation of charges that are formed.
External antistats are generally substances having at
least one hydrophilic molecule ligand, and provide a
more or less hygroscopic film on the surfaces. These
antistats, which are usually surface-active, may be
subdivided into nitrogen-containing (amines, amides,
quaternary ammonium compounds), phosphorus-containing
(phosphoric esters), and sulfur-containing (alkyl-
sulfonates, alkyl sulfates) antistats. External
antistats are described, for example, in Patent
Applications FR 1,156,513, GB 873 214 and GB 839 407.
The lauryl- (or stearyl-)dimethylbenzylammonium
chlorides disclosed here are suitable as antistats for
CA 02313356 2000-07-04
84
textiles and as additives to laundry detergents, in
which case, additionally, a hand effect is obtained.
In order to improve the water absorption capacity, the
rewettability of the treated textiles, and to
facilitate ironing of the treated textiles, silicone
derivatives, for example, may be used in the
compositions produced in accordance with the invention.
These derivatives additionally improve the rinse-out
behavior of the compositions, by virtue of their foam
inhibiting properties. Examples of preferred silicone
derivatives are polydialkylsiloxanes or alkylaryl-
siloxanes where the alkyl groups have one to five
carbon atoms and are totally or partially fluorinated.
Preferred silicones are polydimethylsiloxanes, which
may if desired have been derivatized and in that case
are amino-functional or quaternized, or have Si-OH,
Si-H and/or Si-Cl bonds. The viscosities of the
preferred silicones at 25°C are in the range between
100 and 100,000 centistokes, it being possible to use
the silicones in amounts of between 0.2 and 5~ by
weight, based on the overall composition.
Finally, the compositions produced in accordance with
the invention may also comprise W absorbers, which
attach to the treated textiles and improve the light
stability of the fibers. Compounds which have these
desired properties are, for example, the compounds
which are active via radiationless deactivation, and
derivatives of benzophenone having substituents in
positions) 2 and/or 4. Also suitable are substituted
benzotriazoles, acrylates which are phenyl-substituted
in position 3 (cinnamic acid derivatives), with or
without cyano groups in position 2, salicylates,
organic Ni complexes, and also natural substances such
as umbelliferone and the endogenous urocanic acid.
CA 02313356 2000-07-04
In the course of the above remarks, mention has
occasionally been made of the amount of the individual
substances in the end products of the process of the
invention. Based on the masses to be processed,
5 preference is generally given to processes wherein at
least one of the deformable masses further comprises
one or more substances from the groups of enzymes,
corrosion inhibitors, scale inhibitors, cobuilders,
dyes and/or fragrances in total amounts of from 6 to
10 30~ by weight, preferably from 7.5 to 25~ by weight,
and in particular from 10 to 20~ by weight, based in
each case on the mass.
With all of the abovementioned ingredients,
15 advantageous properties may result from separating them
from other ingredients and/or from formulating them
together with certain other ingredients. In the case of
multiphase tablets, the individual phases may also
differ in the amount they contain of the same
20 ingredient, as a result of which advantages may be
achieved. Processes wherein at least two of the
deformable masses comprise the same active subtonic in
different amounts are preferred. The term "different
amount" relates in this case, as already explained, not
25 to the absolute amount of the ingredient in the mass
but to the relative amount based on the phase weight;
in other words, it is a % by weight based on the
individual mass.
30 The end products of the process of the invention may be
provided in a very wide variety of geometric forms,
this flexibility being one of the many advantages of
the process of the invention. It is also possible,
however, in accordance with the invention to produce
35 tablets which are similar in their appearance to
conventional tablets. For example, they may be
manufactured in predetermined three-dimensional forms
and predetermined sizes, suitable three-dimensional
CA 02313356 2000-07-04
86
forms being virtually any practicable designs - i.e.,
for example, bar, rod or ingot form, cubes, blocks, and
corresponding three-dimensional elements having planar
side faces, and in particular cylindrical designs with
a circular or oval cross section. This last design
covers forms ranging from tablets through to compact
cylinders having a height-to-diameter ratio of more
than 1.
The end products of the process of the invention may in
each case be formed as separate, individual elements
corresponding to the predetermined dosage of the
laundry detergents and/or cleaning products. It is
equally possible, however, to design the cut-to-length
material strands in such a way as to combine a
plurality of such mass units in one compact, with the
ease of separation of smaller, portioned units being
provided for in particular by means of predetermined
breakage points. For the use of textile laundry
detergents in machines of the type customary in Europe,
with a horizontally arranged mechanism, it may be
judicious to design the compacts as tablets, in
cylindrical or block form, preference being given to a
diameter/height ratio in the range from about 0.5:2 to
2:0.5.
The three-dimensional form of another embodiment of the
tablets is adapted in its dimensions to the dispensing
cup of commercially customary washing machines, so that
the tablets can be metered without a dosing aid
directly into the dispensing cup, where they dissolve
during the initial rinse cycle. Alternatively, it is of
course readily possible, and preferred in the context
of the present invention, to use the laundry detergent
tablets by way of a dosing aid.
A further preferred tablet which may be produced as a
platelike or barlike structure with, in alternation,
CA 02313356 2000-07-04
87
long, thick and short, thin segments, so that
individual segments can be broken off from this "slab"
at the predetermined breakage points, represented by
the short, thin segments, and inserted into the
machine. This principle of the "slablike" laundry
detergent tablet may also be realized in other
geometric forms, for example, vertical triangles
connected to one another lengthwise at only one of
their sides.
"Slablike" strand sections of this kind may be
produced, after cutting to length, by means of an
aftertreatment step which comprises pressing a second
blade or a second set of blades into the cut-to-length
strand sections without dividing them. Superficial
shaping or the production of positive or negative
indicia may also take place in accordance with the
invention. Preferred processes, accordingly, are those
wherein the cut-to-length tablets are subjected to an
aftertreatment step.
In addition to the impression of indicia, the
aftertreatment step may also comprise the impression of
patterns, shapes, etc. In this way it is possible, for
example, to label universal laundry detergents produced
in accordance with the invention by a t-shirt symbol,
color laundry detergents produced in accordance with
the invention by a wool symbol, cleaning product
tablets for machine dishwashing produced in accordance
with the invention by symbols such as glasses, plates,
pots, pans, etc. No limits are imposed in this case on
the creativity of product managers. Preferred processes
of the invention therefore comprise as aftertreatment
step an additional shaping step, especially one of
impression.
Subsequent coating of the cut-to-length tablets is also
possible, provided the application of an additional
CA 02313356 2000-07-04
88
coating is desirable. In this case, then, processes are
preferred wherein the aftertreatment step comprises the
coating of the tablets with a pourable material,
preferably a pourable material having a viscosity
< 5000 mPas.
Independently of the number of the phases and the
nature of the aftertreatment, preference is generally
given to processes wherein the tablets have a density
of more than 800 kg dm-3, preferably more than 900 kg
dm-3, with particular preference more than 1000 kg dm-3,
and in particular more than 1100 kg dm-3. In such
tablets, the advantages of the commercial form of a
compact laundry detergent or cleaning product are
manifested particularly clearly.
The present invention provides a process which makes it
possible to produce laundry detergent and cleaning
product tablets simply and under changing framework
conditions. A preferred hardening mechanism in this
context, as described above, consists in time-delayed
water binding, corresponding laundry detergent and
cleaning product tablets having not been described in
the prior art. The present invention therefore
additionally provides a laundry detergent or cleaning
product tablet comprising at least 30°s by weight of
phosphate(s), wherein the water content of the tablet
is from 50 to 100 of the calculated water binding
capacity.
With regard to the definition of the water binding
capacity and its calculation, reference may be made to
the above remarks, in order to avoid redundancy. The
phosphate content of preferred tablets produced in
accordance with the invention is higher, so that
preferred laundry detergent and cleaning product
tablets are those which comprise at least 40% by
weight, preferably at least 45~ by weight, and in
CA 02313356 2000-07-04
89
particular at least 50% by weight, of phosphate(s),
based in each case on the tablet weight.
As already mentioned in connection with the remarks
relating to the process of the invention, phosphates
whose use is particularly preferred are alkali metal
phosphates. Therefore, completely analogously,
preference is given to laundry detergent and cleaning
product tablets which comprise alkali metal
phosphate(s), with particular preference pentasodium
and/or pentapotassium triphosphate (sodium and/or
potassium tripolyphosphate), in amounts of from 30 to
80% by weight, preferably from 35 to 75% by weight, and
in particular from 50 to 70% by weight, based in each
case on the tablet weight.
In the description of the process of the invention it
was explained that process end products which are
particularly preferred in the context of the present
invention not only possess an extremely low proportion
of free water but are preferably themselves still able
to bind further free water. In preferred laundry
detergent and cleaning product tablets, therefore, the
water content of the tablets is from 55 to 95%,
preferably from 60 to 90%, and in particular from 65 to
85%, of the calculated water binding capacity.
With regard to further ingredients, their amounts and
physical properties, it is possible to refer to the
above remarks, as it is with regard to the multiphase
nature of tablets of the invention, the division of
ingredients between the individual phases, and the
proportions of the phases with respect to one another.
While the invention has been described with particular
reference to certain embodiments thereof, it will be
understood that changes and modifications may be made
CA 02313356 2000-07-04
by those of ordinary skill in the art within the scope
and spirit of the following claims.
In the claims, the word "comprising" means "including
5 the following elements (in the body), but not excluding
others"; the phrase "consisting of" means "excluding
more than traces of other than the recited
ingredients"; and the phrase "consisting essentially
of" means "excluding unspecified ingredients which
10 materially affect the basic characteristics of the
composition".
