Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02311989 2000-06-19
COMPRESSION PROCESS FOR LAUNDRY DETERGENT AND CLEANING
PRODUCT TABLETS
Field of the Invention
The present invention relates to a process for
producing laundry detergent and cleaning product
tablets and to tablets produced by this process, and to
the use thereof. The invention relates in particular to
tablets and production processes such as laundry
detergent tablets, cleaning product tablets, bleach
tablets or water softener tablets and their respective
production.
Background of the Invention
Laundry detergent and cleaning product tablets have
become firmly established alongside liquid and
particulate products as commercial forms for
compositions of the abovementioned type, since they
possess a range of advantages, such as ease of
metering, safe handling, high compaction and, as a
result, reduced packaging, transport and storage cost,
as well as esthetic appeal.
But there are disadvantages as well as these
advantages. In many cases, compression to sufficiently
stable tablets results in reduced solubility or
disintegration rate, which is particularly undesirable
in laundry detergent and cleaning product tablets. If,
on the other hand, better solubility is sought by only
gently compressing the tablets, then problems such as
breakage, edge fracture and abrasion occur, which are
perceived by the consumer as undesirable.
One solution proposed in response to this in the prior
art is to use coated tablets in which a "shell"
envelops the internally situated laundry detergent and
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cleaning product tablet ("core") and gives it
stability.
Coated laundry detergent tablets are described, for
example, in European Patent Application EP 716 144
(Unilever). According to the teaching of that document,
a coating of water-soluble material is said to reduce
tablet friability and abrasion without affecting the
solubility. Coating materials specified in that ,
document are, in particular, film-forming materials
such as water-soluble polymers or sugars. The coating
is applied in a process downstream of the tableting
operation and accounts in terms of weight for a few
percent of the finished tablet.
Coated laundry detergent tablets are also described in
European Patent Applications EP 846 754, EP 846 755 and
EP 846 756 (all Procter & Gamble). According to the
teaching of these documents, coatings containing
dicarboxylic acids are applied in the form of melts or
solutions to precompressed tablets. Here again, the
coating, in terms of weight, accounts for a few percent
of the finished tablet and requires a separate
processing step for its application.
In the cited cases of the prior art, the coating
fulfils the function of a protective coat around the
tablets produced beforehand, and fulfills no functions
in the subsequent washing or cleaning process. Based on
the overall weight of the tablets, therefore, the
consumer is sold a certain percentage of material free
of active substance. Furthermore, the above-described
technology necessitates the use of two different
process stages: tableting, on the one hand, and
coating, on the other. This places an unfavorable
burden on the process economics.
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Suximnary of the Invention
It is an object of the present invention to provide
laundry detergent and cleaning product tablets which
achieve the advantages of coating tablets without the
use of materials that are of no benefit in the washing
or cleaning operation. High mechanical stability to
impact, jolting and friction, i.e., high fracture
resistance and low friability and abrasion tendency,
are to be achieved together with high active substance
contents even in the coating.
In addition, the intention is to avoid further process
steps, in order to reduce the costs of producing the
tablets. A further object is to provide a tablet
coating which brings the abovementioned advantages
without the need for a special coating step following
compression.
It has now been found that by means of a special
compression process it is possible to produce surface-
enhanced laundry detergent and cleaning product tablets
whose outer layers have the quality of a conventional
coating and exhibit the abovementioned advantages.
The present invention provides a process for producing
laundry detergent and cleaning product tablets by
compressing one or more particulate laundry detergent
and cleaning product compositions in a tableting press.
in which at least one punch of a press-punch pair is
rotated about its vertical axis during the tableting
operation.
Without wishing to be bound by the theory, the
applicant assumes that by virtue of the rotation of at
least one punch of a press-punch pair during the
tableting operation the tablet surface becomes harder,
as a result of friction, than the rest of the tablet.
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In this way, even with low pressing forces, a thin,
relatively hard layer is produced in the form of a
shell on the surface of the tablet, significantly
increasing the stability of the tablet and its
resistance to abrasion. A particular advantage here is
that the relatively hard "shell" consists of the same
premix as the rest of the tablet, i.e., it has the same
composition. This avoids the use of coating layers free
from active substance. At the same time, the coating is
produced actually in the course of the pressing
operation, obviating the need for downstream coating
process steps.
Overall, through the process of the invention, the
compressive pressure, which is in any case much lower
with laundry detergent and cleaning product tablets
than for other tableting mixtures, may be reduced
further without the fear of disadvantages in respect of
stability during handling or transport. The overall
further reduction in compressive pressure leads,
advantageously, to even faster-dissolving tablets.
Detailed Description of the Invention
In order to achieve a "shell" structure that is as
homogeneous as possible around the entire tablet, it is
of advantage if not only one press punch of a punch
pair rotates but rather upper punch and lower punch
each rotate around their vertical axis during the
tableting operation. Processes in which both punches of
a press-punch pair are case rotated about their
vertical axis during the tableting operation are,
accordingly, preferred.
The rotation of two punches whose pressing faces are
opposite one another may be codirectional or
counterdirectional. In addition, the angle of rotation,
and with it the rotary speed, of the punches may
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differ. Although, in accordance with the invention, all
six conceivable embodiments (same direction of
rotation, upper punch rotates faster/further; same
direction of rotation, lower punch rotates
faster/further; different direction of rotation, upper
punch rotates faster/further; different direction of
rotation, lower punch rotates faster/further; same
direction of rotation, both punches rotate equally
fast/far; opposite direction of rotation, both punches
move equally fast/far) lead to success and may be used,
process variants in which the punches are rotated in
opposite directions have been found to be preferred.
The rotary speed, and the angular amount by which the
punches are rotated, may be the same or different. It
has been found advantageous to select identical punch
speeds for the production of single-phase tablets
whereas for the production of multilayer tablets the
speed of one punch may be coordinated with the
composition of the premix which comes into contact with
it. Through variation of the parameters of mixture
composition, rotational speed and surface quality of
the press punch, the physical properties of the coating
layer may be varied in a controlled manner.
The rotation of the tableting punches) may in
principle take place at any point in the tableting
operation. An appropriate point in time is, for
example, a punch rotation when the compressed laundry
detergent and cleaning product tablet is ejected from
the die and is surface-treated by the punches) in the
course of its ejection. Accordingly, processes wherein
the rotation of the punches) takes place following
compression, in the ejection region of the tableting
press, are preferred embodiments.
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Particularly suitable points in time at which to form
stable coating layers are those in which the punches
are pressure-loaded, i.e., for example, during the
precompaction of the introduced premix and/or during
the final compression leading to the finished laundry
detergent and cleaning product tablet. After the
particulate premix (the particulate laundry detergent
and cleaning product composition) has been introduced,
the lower punch may be raised, the upper punch lowered,
and uniform distribution of the premix in the die
enabled by rotating the punch(es). In this case, the
bed of particles is deaerated at the same time,
improving the homogeneity of the tablet and its uniform
stability in all areas of the tablet. The deaeration of
the particle bed permits reduced tablet friability and
greater tableting press output. Accordingly, processes
wherein the rotation of the press punches) takes place
in the filling and/or pressure region of the tableting
press, preferably in the filling and pressure region,
are preferred.
The abovementioned points in time for rotation of the
punches) may be combined with one another as desired.
In this context it is particularly advantageous if the
punch (es) is (are) rotated not only at the
precompression stage (in the filling region) but also
in the main compression stage (in the pressure region)
and after the compression stage (in the ejection
region). Preferred processes are, therefore, those
wherein rotation of the press punches) is carried out
at the precompression stage and at the main compression
stage and, optionally, after the compression stage.
The disintegration of the tablets may be sharply
reduced as a result of an incorrect choice of the point
in time for rotation. It has been observed that there
is a marked deterioration in the disintegration times
CA 02311989 2000-06-19
if the punches) is (are) rotated at the point in time
at which the compressive force is between 40 and 100
of the maximum compressive force. Accordingly,
preferred points in time for rotation are those at
which the compressive forces at the punch (es) are from
0 to 405 of the maximum compressive force, preferably
from 0 to 20~ of the maximum compressive force.
The rotation of the punches can be effected
constructionally by means of cams on the punch, the
rotation being carried out by way of stop rails on the
press. Furthermore, the rotation may also be effected
by means of driven plastic rollers which bear on the
punches at certain times. It is also possible to
provide the punches with a toothed wheel. The rotation
is effected by way of toothed rails mounted on the
press. The combination of materials for the toothed
wheel/toothed rail pairing should preferably be chosen
such that in operation the toothed rail is subject to
greater wear. It is appropriate, for example, to give
the toothed rail a spring mounting in order to build up
slowly the acting forces on the tooth faces.
The details above relate, verbally, closely to the
production of single-phase tablets from a particulate
premix which is a laundry detergent and cleaning
product composition. However, the process of the
invention is by no means restricted thereto; rather,
multiphase tablets as well may be produced with the
advantages of the process of the invention. The present
invention therefore further provides a process for
producing multiphase laundry detergent and cleaning
product tablets by compressing a plurality of
particulate laundry detergent and cleaning product
compositions in a tableting press in which at least one
punch of a press-punch pair is rotated about its
vertical axis during the tableting operation.
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In complete analogy to the remarks above, preferred
processes for the production of multiphase tablets as
well are those wherein both punches of a press-punch
pair are each rotated about their vertical axis during
the tableting operation. Also, processes wherein the
punches are rotated in opposite directions are
preferred embodiments of the process of the invention
for producing multiphase tablets.
In this process of the invention, the rotation of the
punches may likewise take place at a wide variety of
positions and at a wide variety of points in time in
the tableting process. In analogy to the above remarks,
preference in the production of multiphase tablets is
also given to processes wherein the rotation of the
press punches) takes place following compression, in
the ejection region of the tableting press.
With the production of multiphase tablets as well, of
course, the rotation of the press punches) in the
filling and/or pressure region of the tableting press,
preferably in the filling and pressure region, which
was emphasized above as being advantageous, is
advantageous.
In preferred processes, therefore, rotation of the
press punches) is carried out at the precompression
stage of the first premix and at each further
precompression stage of further premixes and at the
main compression stage of the multiphase tablet, and,
optionally, after the compression stage.
In the context of the production of multiphase tablets,
the adhesion of the individual phases to one another
may be improved by abandoning precompression between
the metering steps for the individual premixes. At the
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same time this avoids the multiple exertion of
compressive pressure on the first premix, which is
disadvantageous for the solubility of the first phase.
A further embodiment therefore envisages processes of
the invention wherein no intermediate compression takes
place between the metering steps for the individual
premixes.
The press punches used in the process of the invention
may possess surface structures of any desired form,
although rotation of the punches requires that the
punches be circular. To produce simple or multilayer
circular (biplanar) tablets it is possible to use
punches having planar surfaces, as are known for the
conventional tableting processes. In order to produce
specially shaped tablets, which may likewise be
composed of two or more layers, it is also possible to
use punches having elevations or indentations, which
may in turn be rotationally symmetric along the
longitudinal axis of the punch. For example, it is
possible to use a punch in which a cylinder having a
relatively small diameter has been applied to a base
area of greater diameter. In production, punches of
this kind produce tablets having a circular depression
which protrudes into the circular tablet. A
corresponding cylindrical depression in the press punch
leads to a tablet having the form of two cylinders
stacked one atop the other. Normally, the diameter-to-
height ratio of such cylinders is more than 1,
preferably more than 1.5, and in particular more
than 2.
Said modifications may of course be carried out on
upper and lower punches, thereby producing either,
again, annular tablets (the mounted cylinders meet in
the middle of the tablet during the pressing operation
and form the continuous hole) or double-depression
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tablets or tablets having the form of three cylinders
stacked atop each other.
The principle depicted above may also be extended to
two, three or more successive elevations or
indentations on the punch surface. It is also possible
to mount rings on the punch surface or mill rings into
it, with the resulting tablets having annular
indentations or elevations.
One particularly preferred embodiment of the present
invention provides for the use of domed punch surfaces.
In this case, one punch can be chosen to be planar
while the other punch is convexly or concavely curved.
This results in tablets having a concave indentation or
convex elevation on one side while the other side is
planar. The last-mentioned tablets, having an upwardly
domed "lens-shaped" elevation, may be transported on
conventional conveyor belts owing to their smooth
undersides and make it possible, for example, to raise
the tablets where this is desired. The combination of
two convexly or concavely curved punches is likewise
possible and leads to biconcave or biconvex tablets,
the latter again being able to have a greater overall
height. Depending on the filling volume of the die it
is possible to realize a more or less thick cylindrical
"rim" between the domed faces. Also possible, not
least, is the combination of a convexly curved lower
punch with a concavely curved upper punch (or vice
versa), resulting in a tablet having the shape of a
watchglass. For a given mass and given diameter, such
tablets have a greater height than biplanar tablets.
Of course, fluid transitions between the individual
forms mentioned are possible. Another preferred
embodiment of tableting punches envisages an annular
elevation on the edge of the punch, preferably with a
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triangular cross section. By means of such punches it
is possible to produce tablets having a faceted edge
(beveled edges). Here again, there are virtually no
limits on the design diversity, so that the faceted
edge may also be quadrant-shaped, stepped, multiply
curved, etc. in design.
The production of multiphase tablets may result in
different design forms. Thus it is possible, depending
on the shaping of the press tools, to produce
core/jacket or ring-core tablets. Bulleye tablets may
also be produced by the pressing technology of the
invention. In all embodiments of the press tools it is
necessary to ensure that the rotating punches are
rotationally symmetric so that when the punch/punches
rotate no shifts occur in the structure of the mixture
in the die. Since the production of the abovementioned
multiphase tablets entails a high level of technical
expenditure, it may be advantageous on grounds of
process economics to use planar, circular press tools
and to produce tablets having a layer construction.
Accordingly, processes wherein the phases have the form
of layers are preferred.
The details given below apply independently of whether
single-phase, double-layer or multiphase tablets with
different structures are being produced. They relate in
particular to the operation of rotation in accordance
with the invention.
Regarding the direction of rotation of the rotating
punch(es), reference may be made to the details given
above. The amount by which the punch rotates may
likewise be varied within wide limits, all embodiments
being possible from the small rotation by a few tenths
of a degree through to complete rotation. In view of
the time spent by the press punches in the rotational
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positions, which is short at high throughputs,
preference is given to processes wherein the press
punches) is (are) rotated by from 0.1 to 90°,
preferably by from 0.25 to 45°, and in particular by
from 0.5 to 20°, at each rotation.
The amount of rotation of one punch, as already
remarked above, is thus not tied to the amount of
rotation of the other punch in the punch pair. Entirely
analogously, depending on the rotational position, the
punch may be rotated by different amounts. For example,
it is possible to rotate a punch by five degrees of
angle in the filling region, whereas the same punch is
rotated by 0.5° in the compression region and by 45° in
the ejection region. Of course, the figures mentioned
are merely exemplary in nature, and at each rotational
position a punch rnay be rotated by any conceivable
amount. Rotation may be characterized not only by the
angle traveled but also by the intensity of the
rotation. This depends, in turn, on the time within
which the rotation is completed. In the light of the
throughputs of the tableting press, which should
advantageously be high, the punch has only a limited
time available for the rotation. Processes wherein the
rotation of the press punches) is carried out over a
period of from 1 to 1000 ms, preferably from 2 to
500 ms, and in particular from 5 to 100 ms, are
preferred. In this way, depending on the size of the
angle to be traveled, high angular velocities are
achieved which lead to the desired friction on the
surface of the tablet and to the formation of the
coating layer.
In addition to the abovementioned factors of time
(travel) and intensity of rotation, the thickness of
the coating layer may also be influenced by way of the
nature of the press punches, the compressive pressure,
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and the pressing temperature. Long paths of rotation,
rapid rotations, rough punch surfaces, and increased
pressing temperatures result in a thicker and thus more
stable layer. The roughness of the punch surfaces may
be indicated by the extent of the peak-to-valley
height, which describes the difference in height
between the lowest and the highest point of the punch
surface. In accordance with the invention, processes
wherein the pressing faces of the press punches have a
peak-to-valley height of from 5 to 500 ~,m, preferably
from 10 to 250 ~.m, and in particular from 20 to 150 Vim,
are preferred.
Preference is likewise given in accordance with the
invention to processes wherein compression is conducted
at temperatures between 10 and 60°C, preferably between
15 and 50°C, and in particular between 20 and 40°C.
The compressive forces for the process of the invention
are preferably within the range from 1 to 50 kN, in
particular from 5 to 20 kN, these being the maximum
forces (main compressive forces) obtaining at the
punches. In accordance with the above-described
preferred point in time of rotation of the punches,
therefore, the punches) is (are) preferably rotated
with compressive forces of from 0.2 to 20 kN, in
particular from 1 to 8 kN, obtaining. Such forces lead
to different pressures depending on the size of the
area over which the force is distributed. In preferred
process variants, these pressures are between 50 and
2500 N cm-2, in particular between 100 and 1500 N cm-2,
the figure in turn representing the main compressive
pressure. In preferred processes of the invention,
rotation of the punches takes place with compressive
pressures of between 10 and 1000 N cm-z, in particular
between 20 and 600 N cm-2.
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The process of the invention is used to produce laundry
detergent and cleaning product tablets and consists in
the compression of one or more particulate laundry
detergent and cleaning product compositions.
Advantageous effects of the process end products may be
achieved by means of suitable compositions and/or
physical parameters of this (these) laundry detergent
and cleaning product composition(s). The text below
contains details of physical parameters and ingredients
of the laundry detergent and cleaning product
compositions, which are also referred to in the context
of the present invention as "premixes".
For a high density of the resulting tablets it is
advantageous if the premix for compression has a
relatively high bulk denisity. In particular, processes
wherein the particulate laundry detergent and cleaning
product compositions) has (have) a bulk density of at
least 500 g/l, preferably at least 600 g/1, and in
particular at least 700 g/1, are preferred embodiments
of the present invention.
It is also possible to give details of the particle
size and the particle size distribution of the laundry
detergent and cleaning product compositions) for
compression. For example, preferred processes are those
wherein the particulate laundry detergent and cleaning
product compositions) has (have) particle sizes of
between 100 and 2000 ~.m, preferably between 200 and
1800 Vim, with particular preference between 400 and
1600 ~,m, and in particular between 600 and 1400 ~,m.
Within the stated particle size ranges as well it is
possible to perceive tendencies as to which premixes
are particularly suitable. Processes wherein the
particulate laundry detergent and cleaning product
compositions) comprises/comprise less than 20~ by
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weight, preferably less than 10~ by weight, and in
particular less than 5~ by weight, of particles having
a size below 200 ~.m are further preferred in accordance
with the invention. Similar details may also be given
regarding the upper limit of the particle size
distribution. Here, preferred processes are those
wherein the particulate laundry detergent. and cleaning
product compositions) comprises/comprise less than 20~
by weight, preferably less than 10% by weight, and in
particular less than 5~ by weight, of particles having
a size above 1600 Vim.
In accordance with the process of the invention, it is
possible to produce, for example, laundry detergent
tablets with particular preference. Whereas in
detergent tablets for machine dishwashing, for example,
the fraction of surfactants is small and this
surfactant fraction may be entirely absent from bleach
tablets or water softener tablets, surfactants are an
essential constituent of textile laundry detergents,
irrespective of their commercial form. Laundry
detergent tablets are normally produced by blending
surfactant granules with preparation components and
subsequently compressing this particulate premix. In
preferred variants of the process of the invention,
therefore, the premix, or at least one of the premixes,
for compression further comprises one or more types of
surfactant-containing granules.
Processes which are preferred in the context of the
present invention therefore comprise compressing a
particulate premix comprising at least one type of
surfactant-containing granules and at least one admixed
pulverulent component. The surfactant-containing
granules may be produced by customary industrial
granulation processes such as compacting, extrusion,
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mixer granulation, pelletizing, or fluidized bed
granulation.
In preferred process variants, the surfactant-
s containing granules likewise satisfy defined particle
size criteria. For instance, preference is given to
processes of the invention wherein the surfactant-
containing granules have particle sizes of between 100
and 2000 Vim, preferably between 200 and 1800 Vim, with
particular preference between 400 and 1600 ~,m, and in
particular between 600 and 1400 Vim.
In addition to the active substances (anionic and/or
nonionic and/or cationic and/or amphoteric
surfactants), the surfactant granules preferably
further comprise carrier materials, which with
particular preference come from the group of the
builders. Particularly advantageous processes are those
wherein the surfactant-containing granules comprise
anionic and/or nonionic surfactants and also builders
and have total surfactant contents of at least 10~ by
weight, preferably at least 15~ by weight, and in
particular at least 20~ by weight, based on the
granules.
These surface-active substances come from the group of
the anionic, nonionic, zwitterionic or cationic
surfactants, anionic surfactants being distinctly
preferred for economic reasons and on account of their
performance spectrum.
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 Cla-la monoolefins having
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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 Clz-le
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
22 carbon atoms, examples being those of caproic acid,
caprylic acid, capric acid, myristic acid, lauric acid,
palmitic acid, stearic acid, or behenic acid.
Preferred alk(en)yl sulfates are the alkali metal
salts, and especially the sodium salts, of the sulfuric
monoesters of Clz-C18 fatty alcohols, examples being
those of coconut fatty alcohol, tallow fatty alcohol,
lauryl, myristyl, cetyl or stearyl alcohol, or of Clo-
Czo oxo alcohols, and those rnonoesters 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
possessing degradation properties similar to those of
the corresponding compounds based on fatty-chemical raw
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materials. From a detergents standpoint, the Clz-Cls
alkyl sulfates and Clz-C,,s alkyl sulfates, and also
C14-Cls alkyl sulfates, are preferred. In addition, 2, 3-
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.
Also suitable are the sulfuric monoesters of the
straight-chain or branched C,_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-is fatty alcohols
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.
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
acid with alcohols, preferably fatty alcohols and
especially ethoxylated fatty alcohols. Preferred
sulfosuccinates comprise C8_1$ 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.
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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.
In the context of the present invention, preference is
given to surfactant granules which contain from 5 to
50% by weight, preferably from 7.5 yo 40% by weight,
and in particular from 10 to 30% by weight, of anionic
surfactant(s), based in each case on the granules.
In the selection of the anionic surfactants there are
no boundary conditions to be observed which stand in
the way of freedom to formulate. Preferred surfactant
granules, however, have a soap content which exceeds
0.2% by weight, based on the overall weight of the
laundry detergent and cleaning product tablet produced.
Anionic surfactants for use with preference are the
alkylbenzenesulfonates and fatty alcohol sulfates, with
preferred laundry detergent and cleaning product
tablets containing from 2 to 20% by weight, preferably
from 2.5 to 15% by weight, and in particular from 5 to
10% by weight, of fatty alcohol sulfate(s), based in
each case on the weight of the laundry detergent and
cleaning product tablets.
CA 02311989 2000-06-19
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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
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 E0, C13-15 alcohols containing 3 EO,
5 EO, 7 EO or 8 EO, Clz-1$ alcohols containing 3 EO, 5 EO
or 7 EO, and mixtures thereof , such as mixtures of Clz-14
alcohol containing 3 EO and Clz-18 alcohol containing
5 E0. 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.
A further class of nonionic surfactants used with
preference, which are used either as sole nonionic
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
CA 02311989 2000-06-19
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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.
Another class of nonionic surfactants which may be used
with advantage are the alkyl polyglycosides (APGs).
Alkyl polyglycosides suitable for use satisfy the
general formula RO(G)Z, where R is a linear or branched
aliphatic radical, especially an aliphatic radical
which is methyl-branched in position 2, which is
saturated or unsaturated and has 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 glycosidation, z, is between 1.0
and 4.0, preferably between 1.0 and 2.0, and in
particular between 1.1 and 1.4.
Preference is given to the use of linear alkyl
polyglucosides, i.e. alkyl polyglycosides in which the
polyglycosyl radical is a glucose radical and the alkyl
radical is an n-alkyl radical.
The process end products of the process of the
invention may preferably include alkyl polyglycosides,
preference being given to APG contents of more than
0.2% by weight, based on the overall tablet.
Particularly preferred laundry detergent and cleaning
product tablets contain APGs in amounts of from 0.2 to
10% by weight, preferably from 0.2 to 5% by weight, and
in particular from 0.5 to 3% by weight.
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 be also be suitable.
The amount of these nonionic surfactants is preferably
CA 02311989 2000-06-19
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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 (I),
R1
R-CO-N-[ZJ (I)
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.
The group of the polyhydroxy fatty acid amides also
includes compounds of the formula (II)
R j -O-RZ
R-CO-N-[ZJ (II)
where R is a linear or branched alkyl or alkenyl
radical having 7 to 12 carbon atoms, R1 is a linear,
branched or cyclic alkyl radical or an aryl radical
having 2 to 8 carbon atoms and R2 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,
CA 02311989 2000-06-19
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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 TAO-A-95/07331 by
reaction with fatty acid methyl esters in the presence
of an alkoxide as catalyst.
Irrespective of whether anionic or nonionic surfactants
or mixtures of these classes of surfactant, and also,
if desired, amphoteric or cationic surfactants, are
used in the surfactant granules, preferred processes of
the invention are those wherein the surfactant content
of the surfactant-containing granules is from 5 to 60
by weight, preferably from 10 to 50~ by weight, and in
particular from 15 to 40~ by weight, based in each case
on the surfactant granules.
The surfactant granules may be used in varying amounts
in the laundry detergent and cleaning product tablets
or in individual phases of multiphase tablets.
Processes of the invention wherein the proportion of
the surfactant-containing granules in the laundry
detergent and cleaning product tablets, or in an
individual phase of the laundry detergent and cleaning
product tablet, is from 40 to 95~ by weight, preferably
from 45 to 85~ by weight, and in particular from 55 to
75~ by weight, based in each case on the weight of the
laundry detergent and cleaning product tablets, are
preferred.
CA 02311989 2000-06-19
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From a performance standpoint it may be advantageous if
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
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
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 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
which at least one phase of the tablet is free from
anionic surfactants.
It has been found.that the surfactant content of the
premixes for compression influences the quality of the
coating layer produced by the process of the invention.
As the surfactant content increases there is an
improvement in the stability of the coating layer. Thus
it is preferred for the surfactant content of the
tableting premix to be more than 10~ by weight and with
particular preference more than 15~ by weight.
CA 02311989 2000-06-19
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The nature of the surfactants used also has an
influence on the coating layer. With relatively high
proportions of nonionic surfactants, there is an
increasing deterioration in the disintegration time of
the tablets produced. Thus preference is given to a
premix in which the ratio of nonionic surfactants to
anionic surfactants is greater than 2:1, preferably
greater than 3:1.
On the other hand it was found, especially in
connection with the tableting of formulas containing
zeolite, that a certain nonionic surfactant content is
useful for the formation of the coating layer. The
nonionic surfactant content of a zeolite-containing
tablet of this kind is therefore preferably at least 2%
by weight, more preferably at least 3% by weight.
In addition to the wash-active substances, builders are
the most important ingredients of laundry detergent and
cleaning products. In the surfactant granules, but also
as a constituent of the premix, it is possible for all
of the builders commonly used in laundry detergents and
cleaning products to be present, i.e. in particular
zeolites, silicates, carbonates, organic cobuilders,
and - where there are no ecological prejudices against
their use - phosphates as well. The latter are builders
preferred for use in particular in detergent tablets
for machine dishwashing.
Suitable crystalline, layered sodium silicates possess
the general formula NaMSiX02X+1yH20, where M is sodium or
hydrogen, x is a number from 1.9 to 4, y is a number
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
CA 02311989 2000-06-19
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and x adopts the value 2 or 3. In particular, both (S
and 8-sodium disilicates Na2SizO5~yH20 are preferred,
(3-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,
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 -radiation, having a width of several degree
X
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 product s 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.
CA 02311989 2000-06-19
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The finely crystalline, synthetic zeolite used,
containing bound water, is preferably zeolite A
and/or P. A particularly preferred zeolite P is Zeolite
MAP~ (commercial product from Crosfield). Also
suitable, however, are zeolite X and also mixtures of
A, X and/or P. A product available commercially and
able to be used with preference in the context of the
present invention, for example, is a cocrystallizate of
zeolite X and zeolite A (approximately 80~ 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
nNa20~ (1-n) KZO~A12O3~ (2-2 . 5) Si02~ (3 .5-5.5) H20.
The zeolite may be used either as a builder in a
granular compound or as a kind of "powdering" for the
entire mixture intended for compression, it being
common to utilize both methods for incorporating the
zeolite into the premix. Suitable zeolites have an
average particle size of less than 10 ~m (volume
distribution; measurement method: Coulter counter) and
contain preferably from 18 to 22~ by weight, in
particular from 20 to 22~ by weight, of bound water.
Of course, the widely known phosphates may also be used
as builder substances provided such a use is not to be
avoided on ecological grounds. Among the large number
of commercially available phosphates, the alkali metal
phosphates, with particular preference being given to
pentasodium and pentapotassium triphosphate (sodium and
potassium tripolyphosphate, respectively), possess the
greatest importance in the laundry detergent and
cleaning product industry.
Alkali metal phosphates is the collective term for the
alkali metal (especially sodium and potassium) salts of
CA 02311989 2000-06-19
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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
dehydrate (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 conversion at 200°C into the weakly acidic
diphosphate (disodium dihydrogen diphosphate, Na2H2P20~)
and at the higher temperature into sodium
trimetaphosphate (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 diphosphate, 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
CA 02311989 2000-06-19
- 29 -
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
(corresponding 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 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 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. Na4P20~ is
formed when disodium phosphate is heated at > 200° or
by reacting phosphoric acid with sodium carbonate in
CA 02311989 2000-06-19
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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
pyrophosphate) , ICøP20~, 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 1% strength solution at 25° being 10.4.
Condensation of NaH2P04 or of KH2P04 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
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 Hz0 and has the general formula
Na4- [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° for two hours, about
8% orthophosphate and 15% diphosphate are produced by
hydrolysis. For the preparation of pentasodium
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, K5P301o
CA 02311989 2000-06-19
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(potassium tripolyphosphate), is commercialized, for
example, in the form of a 50~ strength by weight
solution (> 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 ~ Na3K2P301o + H20
They 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 potassium tripolyphosphate,
or mixtures of sodium tripolyphosphate and potassium
tripolyphosphate and sodium potassium tripolyphospate,
may also be used in accordance with the invention.
Organic cobuilders which may be used in the laundry
detergent and cleaning product tablets of the invention
are, in particular, polycarboxylates/polycarboxylic
acids, polymeric polycarboxylates, aspartic acid,
polyacetals, dextrins, further organic cobuilders (see
below), and phosphonates. These classes of substance
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,
CA 02311989 2000-06-19
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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.
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.
CA 02311989 2000-06-19
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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.
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 allyl sulfonic 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
CA 02311989 2000-06-19
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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
obtained from dialdehydes such as glyoxal,
glutaraldehyde, terephthalaldehyde and mixtures thereof
and from polyol carboxylic acids such as gluconic acid
and/or glucoheptonic acid.
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
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
the range from 0.5 to 40, in particular from 2 to 30,
CA 02311989 2000-06-19
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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
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.
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
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 WO 92/18542,
WO 93/08251, WO 93/16110, WO 94/28030, WO 95/07303,
WO 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
at C6 of the saccharide ring may be particularly
advantageous.
Oxydisuccinates and other derivatives of disuccinates,
preferably ethylenediamine disuccinate, are also
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,
CA 02311989 2000-06-19
- 36 -
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
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, expecially 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.
The amount of builder is usually between 10 and 70~ by
weight, preferably between 15 and 60~ by weight, and in
particular between 20 and 50~ by weight. In turn, the
CA 02311989 2000-06-19
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amount of builders used is dependent on the intended
use, so that bleach tablets may contain higher amounts
of builders (for example, between 20 and 70% by weight,
preferably between 25 and 65% by weight, and in
particular between 30 and 55% by weight) than, say,
laundry detergent tablets (usually from 10 to 50% by
weight, preferably from 12.5 to 45% by weight, and in
particular between 17.5 and 37.5% by weight). In
detergent tablets for machine dishwashing, even higher
builder contents may be present, for example, from 40
to 95% by weight, preferably from 50 to 90% by weight,
and in particular from 60 to 85% by weight. Water
softener tablets may even consist of builders to the
extent of 100% by weight.
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. 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 the possibility on the one hand of an
increase in the intrinsic volume (swelling) and on the
other hand, by way of the release of gases, of the
generation of 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
CA 02311989 2000-06-19
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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.
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.
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 (C6H1o05) n and, considered formally, is a (3-
1,4-polyacetal of cellobiose, which itself is
constructed of two molecules of glucose. Suitable
celluloses consist of from about 500 to 5000 glucose
unit s 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
CA 02311989 2000-06-19
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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~
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~ by weight, and in particular
between 400 and 1200 ~m to the extent of at least 90~
by weight. The abovementioned, relatively coarse
disintegration aids based on cellulose, 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.
CA 02311989 2000-06-19
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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
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
primary particle sizes of approximately 5 ~m and can be
compacted, for example, to granules having an average
particle size of 200 Vim.
Processes which are preferred in the context of the
present invention are those wherein the premix or at
least one of the premixes for compression comprises 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 weight,
and in particular from 4 to 6% by weight, based in each
case on the premix.
With the disintegration aids) as well, particular
effects may result from the complete or partial absence
of such substances from individual phases of multiphase
tablets. Thus it is preferred, for example, to produce
multiphase tablets, especially multilayer tablets,
whose individual phases contain a disintegrant in
different amounts. In this way, active substances may
be released from one phase in a controlled - for
example, accelerated or retarded - manner, giving rise
to performance advantages.
CA 02311989 2000-06-19
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In addition to the abovementioned constituents,
surfactant, builder and disintegration aid, the laundry
detergent and cleaning product tablets of the invention
may further comprise further customary laundry
detergent and cleaning product ingredients from the
group consisting of bleaches, bleach activators,
disintegration aids, enzymes, pH standardizers,
fragrances, perfume carriers, fluorescers, dyes, foam
inhibitors, silicone oils, antiredeposition agents,
optical brighteners, graying inhibitors, color transfer
inhibitors, and corrosion inhibitors.
Among the compounds used as bleaches which yield HzOz in
water, particular importance is possessed by sodium
percarbonate. This "sodium percarbonate" is an
unspecifically used designation for sodium carbonate
peroxohydrates, which strictly speaking are not
"percarbonates" (i.e., salts of percarbonic acid) but
are instead hydrogen peroxide adducts onto sodium
carbonate. The commercial product has the average
composition 2 Na2C03~3 H202 and thus is not a peroxy-
carbonate. Sodium percarbonate forms a white, water-
soluble powder of density 2.14 g cm-3 which readily
breaks down into sodium carbonate and into oxygen which
has a bleaching and 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
erroneously regarded as a peroxycarbonate. Only in 1909
was the compound recognized to be a hydrogen peroxide
addition compound; nevertheless, the historical
designation "sodium percarbonate" has become
established in the art.
Industrially, sodium percarbonate is produced pre-
dominantly by precipitation from aqueous solution
CA 02311989 2000-06-19
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(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 auxiliaries (for example,
polyphosphates, polyacrylates), and stabilizers (for
example, Mg2+ ions). The precipitated salt, which still
contains from 5 to 12~ by weight of mother liquor, is
subsequently centrifuged aff and dried in fluid bed
driers at 90°C. Depending on production process, the
bulk density of the finished product may vary between
800 and 1200 g/1. In general, the percarbonate is
stabilized by means of an additional coating. Coating
processes and substances used for coating have been
described widely in the patent literature. In
principle, it is possible in accordance with the
invention to use all commercially customary types of
percarbonate, as offered, for example, by Solvay
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 H2O2-donating peracidic salts or peracids, such as
perbenzoates, peroxophthalates, diperazelaic acid,
phthaloiminoper acid or diperdodecanedioic acid. With
the use of bleaches, as well, it is possible to
dispense with the use of surfactants and/or builders:
straight bleach tablets may be prepared. If such bleach
tablets are for laundry use, a combination of sodium
percarbonate with sodium sesquicarbonate is preferred,
regardless of the other ingredients of the tablet. If
preparing detergent or bleach tablets for machine
dishwashing, bleaches from the group of organic
bleaches may also be used. Typical organic bleaches are
the diacyl peroxides, such as dibenzoyl peroxide, for
example. Further typical organic bleaches are the
CA 02311989 2000-06-19
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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, but it is also possible to use peroxy-a-
naphthoic acid and magnesium monoperphthalate, (b)
aliphatic or substituted aliphatic peroxy acids, such
as peroxylauric acid, peroxystearic acid, s-
phthalimidoperoxy caproic acid [phthaloiminoperoxy-
hexanoic 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).
Bleaches used in tablets for machine dishwashing may
also be substances which release chlorine or bromine.
Suitable chlorine- or bromine-releasing materials
include, for example, 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.
In order to achieve an improved bleaching action 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
and/or O-acyl groups, such as substances from the class
of the anhydrides, esters, imides and acylated
imidazoles or oximes. Examples are tetraacetylethylene-
CA 02311989 2000-06-19
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diamine (TAED), tetraacetylmethylene-diamine (TAMD),
and tetraacetylhexylenediamine (TAHD), and also
pentaacetylglucose (PAG), 1,5-diacetyl-2,2-dioxo
hexahydro-1,3,5-triazine (DADHT), and isatoic anhydride
(ISA) .
Bleach activators which may be used are compounds which
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 0-acyl and/or N-acyl
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
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
isononanoyloxybenzenesulfonate (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
CA 02311989 2000-06-19
- 45 -
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. 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
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
CA 02311989 2000-06-19
- 46 -
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.
On account of their oxidizing action, it is
advantageous to separate the bleaches from other
ingredients, for which purpose processes of the
invention for producing multiphase tablets are
particularly suitable. Processes where one of the
premixes for compression comprises bleaches while
another premix comprises bleach activators are
preferred.
It may also be advantageous to separate the bleaches
from other ingredients. Processes for producing
multiphase tablets where one of the premixes for
compression comprises bleaches while another premix
comprises enzymes are likewise preferred. Suitable
enzymes in this context 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 instances of
graying. Cellulases and other glycosyl hydrolases may
additionally contribute, by removing pilling and
microfibrils, to color retention and to enhancing the
softness of the textile. For bleaching and/or to
inhibit 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
CA 02311989 2000-06-19
_ 4~ _
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 of
protease and cellulase or of cellulase and lipase or
lipolytic enzymes, or of protease, amylase and lipase
or lipolytic enzymes, or protease, lipase or lipolytic
enzymes and cellulase, but especially protease and/or
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
include, in particular, alpha-amylases, iso-amylases,
pullulanases, and pectinases. Cellulases used are
preferably cellobiohydrolases, endoglucanases and
endoglucosidases, also known as cellobiases, and/or
mixtures thereof. Since different cellulase types
differ in their CMCase and Avicelase activities, the
desired activities may be established by means of
tailored mixtures of the cellulases.
In detergent tablets for machine dishwashing, of
course, different enzymes are used in order to take
account of the different substrates treated and the
different types of stain. Suitable enzymes in this case
include in particular those from the classes of the
hydrolases such as the proteases, esterases, lipases or
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
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
CA 02311989 2000-06-19
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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
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
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 coating 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~ by weight, based in each case on
the premix (es) .
The premixes for compression may likewise have
incorporated into them corrosion inhibitors for
protecting 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, amino-
triazoles, 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 agents containing active
CA 02311989 2000-06-19
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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 being given to
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.
Where corrosion inhibitors are used in multiphase
tablets, it is preferred to separate them from the
bleaches. Processes where one of the premixes for
compression comprises bleaches while another premix
comprises corrosion inhibitors are, accordingly,
preferred.
Further ingredients which may be a constituent of one
or more premixes in the context of the process of the
invention are, for example, dyes, optical brighteners,
fragrances, soil release compounds, soil repellants,
antioxidants, fluorescers, foam inhibitors, silicone
oils, liquid paraffins, color transfer inhibitors,
graying inhibitors, detergency boosters, etc.
In order to enhance the esthetic appeal of the laundry
detergent and cleaning product tablets of the
invention, they may be colored, in whole or in part,
CA 02311989 2000-06-19
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with appropriate dyes. 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 tableware pieces, for example, so as not to
stain them.
Preference for use in laundry detergent tablets
of the
invention is given to all colorants which may be
oxidatively destroyed in the washing process, and also
mixtures thereof with appropriate 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. Suitable
examples include anionic colorants, e.g., anionic
nitroso dyes. One possible colorant is, for example,
naphthol green (Colour Index (CI) Part l: Acid Green
1;
Part 2: 10020), which is obtainable as a c ommercial
product, for example, as Basacid~ Green 970 from
BASF,
Ludwigshafen, and also mixtures thereof with suitable
blue dyes. Further colorants employed are Pigmasol~
Blue 6900 (CI 74160), Pigmasol~ Green 8730 (CI
74260),
Basonyl~ Red 545 FL (CI 45170), Sandolan~ Rhodamine
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 61 814-57-1,
CI Acid Yellow 218) and/or Sandolari 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 in particular
for synthetic fibers. At the same time, it must also be
CA 02311989 2000-06-19
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borne in mind when choosing suitable colorants that
colorants have differing stabilities to oxidation. The
general rule is that water-insoluble colorants are more
stable to oxidation than water-soluble colorants.
Depending on the solubility and thus on the oxidation
sensitivity too, the concentration of the colorant in
the laundry detergent or cleaning products varies. In
the case of readily water-soluble colorants, e.g., the
abovementioned Basacid~ Green or the likewise above-
mentioned Sandolari Blue, colorant concentrations
typically chosen are in the range of several 10-Z to
10-3% by weight. In the case of the pigment dyes, which
are particularly preferred on account of their
brightness but are less readily soluble in water - for
example, the abovementioned Pigmasol~ dyes - the
appropriate concentration of the colorant in the
laundry detergent or cleaning products, in contrast, is
typically from several 10-3 to 10-q% 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
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 UV 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
CA 02311989 2000-06-19
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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. Lohr, ~Detergenta and Textile Washings, 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-sulfo-
styryl)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 and to provide the consumer with not only
the performance of the product 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 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-
benzylcarbinyl acetate, phenylethyl acetate, linalyl
benzoate, benzyl formate, ethyl methylphenylglycinate,
allyl cyclohexylpropionate, styrallyl propionate, and
benzyl salicylate. The ethers include, for example,
CA 02311989 2000-06-19
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benzyl ethyl ether; the aldehydes include, for example,
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
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
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
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
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.
CA 02311989 2000-06-19
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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 repellants). 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,
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
CA 02311989 2000-06-19
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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,
methylhydroxypropylcellulose, methylcarboxymethyl-
cellulose 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.
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-
CA 02311989 2000-06-19
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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
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.
CA 02311989 2000-06-19
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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-C1 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.
In the case of all of the abovementioned ingredients,
advantageous properties may result from separating them
from other ingredients and/or compounding them together
with certain other ingredients. In the case of
multiphase tablets, the individual phases may also
differ in the amount at which they contain the same
ingredient, as a result of which advantages may be
obtained. Processes wherein at least two of the
CA 02311989 2000-06-19
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premixes for compression comprise the same active
substance in different amounts are preferred. The term
"different amount" relates in this case, as already
explained, not to the absolute amount of the ingredient
in the phase but rather to the relative amount, based
on the phase weight; in other words, it is a percentage
by weight, based on the individual phase.
The present invention further provides for the use of
tableting presses where at least one punch of a press-
punch pair is rotated about its vertical axis during
the tableting operation to produce laundry detergent
and cleaning product tablets. In the case of use in
accordance with the invention, all advantageous
embodiments described earlier on above for the process
of the invention are, mutatis mutandis, likewise
preferred. In order to avoid redundancy, reference is
made here to the details given above.
As process end products, the process of the invention
provides laundry detergent and cleaning product tablets
which possess a new and advantageous structure. These
are laundry detergent and cleaning product tablets
which, with a uniform composition, consist of a core
and of a shell surrounding said core. Laundry detergent
and cleaning product tablets of this kind have not been
previously described in the prior art. The invention
therefore further provides laundry detergent and
cleaning product tablets comprising compacted,
particulate laundry detergent and cleaning product,
which comprise a core and a shell surrounding said core
which have the same composition, the shell being harder
than the core.
As a result of the formation of the shell in the
process of the invention, the shell has a hardness
greater than that possessed by the core it protects. At
CA 02311989 2000-06-19
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the same time the shell also has a greater density;
accordingly, the present invention likewise provides
laundry detergent and cleaning product tablets
comprising compacted, particulate laundry detergents
and cleaning products, which comprise a core and a
shell surrounding said core which have the same
composition, the shell having a greater density than
the core.
The principle in accordance with the invention of the
enveloped tablet in which shell and core have the same
composition but characteristically have different
physical parameters may be applied not only to single-
phase laundry detergent and cleaning product tablets.
If, for example, two-layer tablets are produced from
two premixes differing in composition, the process of
the invention produces two-layer laundry detergent and
cleaning product tablets which have two different
layers, pressed onto one another, and a shell
surrounding them, the shell surrounding the first layer
having the same composition as the first layer, and the
shell surrounding the second layer having the same
composition as the second layer. Together, these two
shells produce the harder and/or denser shell which
encases the tablet and gives it its advantageous
properties.
The present invention therefore additionally provides
multiphase laundry detergent and cleaning product
tablets comprising compacted, particulate laundry
detergent and cleaning product compositions, which
comprise a multiphase core and a multiphase shell
surrounding said multiphase core, the individual phases
of which have the same composition as the phases whose
surface they cover, the shell being harder than the
core.
CA 02311989 2000-06-19
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Entirely in analogy to the above remarks, the present
invention additionally provides multiphase laundry
detergent and cleaning product tablets comprising
compacted, particulate laundry detergent and cleaning
product compositions, which comprise a multiphase core
and a multiphase shell surrounding said multiphase
core, the individual phases of which have the same
composition as the phases whose surface they cover, the
shell having a greater density than the core.
With the laundry detergent and cleaning product tablets
of the invention, as well, all of the advantageous
embodiments described earlier on above for the process
of the invention are, mutatis mutandis, likewise
preferred. In order to avoid redundancy, reference is
made here to the details above. Especially in respect
of the ingredients, their proportions in the tablet as
a whole, their distribution between individual phases,
their proportions in the individual phases, etc., the
comments made above apply analogously.
Since the impact and frictional stressing of laundry
detergent and cleaning product tablets is particularly
high on the bases, it is of advantage to protect these
areas in particular against abrasion or fracture.
Laundry detergent and cleaning product tablets where
the shell on the round sides of the tablet has a
thickness of from 5 to 2000 ~.m, preferably from 10 to
1500 Vim, and in particular from 25 to 1000 Vim, are
preferred in accordance with the invention. In
particularly preferred laundry detergent and cleaning
product tablets, the sizes specified also apply to the
annular side face of the tablets.
Since the shell contributes to the stability of the
tablet, the compression forces may be reduced further,
which on the one hand improves the process economics
CA 02311989 2000-06-19
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(see above) and on the other hand also has a positive
influence on the solubilities and disintegration times
of the laundry detergent and cleaning product tablets.
Thus lower strengths may be accepted for the core
enclosed in the shell, which would otherwise be too
fragile and unacceptable. In the case of preferred
laundry detergent and cleaning product tablets, the
core has a diametral fracture strength of less than
30 kPa, preferably of less than 25 kPa, with particular
preference of less than 20 kPa, and in particular of
less than 15 kPa.
At the same time, the shell preferably has a high
hardness which in accordance with the invention is
always greater than the hardness of the core. In
particularly preferred laundry detergent and cleaning
product tablets the shell has a diametral fracture
strength of more than 20 kPa, preferably of more than
kPa, with particular preference of more than 30 kPa,
20 and in particular of more than 35 kPa.
It is. also possible to give details of preferred
densities of shell and core, respectively. Laundry
detergent and cleaning product tablets where the core
25 has a density of more than 600 g/1, preferably more
than 750 g/1, and in particular more than 900 g/l, and
laundry detergent and cleaning product tablets where
the shell has a density of more than 1000 g/1,
preferably of more than 1050 g/1, with particular
preference of more than 1100 g/1 and in particular of
more than 1150 g/1, are preferred in accordance with
the invention.
Through an appropriate choice of the process parameters
such as compressive force, compressing time, direction
of rotation, speed of rotation, intensity of rotation,
premix composition, compressing temperature, etc., the
CA 02311989 2000-06-19
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process of the invention is able to produce thicker or
thinner sheaths as desired. In particularly preferred
laundry detergent and cleaning product tablets, core
and shell are in a weight ratio of from 250:1 to 1:1,
preferably from 100:1 to 5:1, and in particular from
50:1 to 10:1.
Following production, the laundry detergent and
cleaning product tablets of the invention may be
packed, the use of certain packaging systems having
proven particularly useful. A further aspect of the
present invention is a combination of (a) laundry
detergent and/or cleaning product tablets) of the
invention and a packaging system containing the laundry
detergent and/or cleaning product tablet(s), said
packaging system having a moisture vapor transmission
rate of from 0.1 g/mz/day to less than 20 g/m2/day if
said packaging system is stored at 23°C and a relative
equilibrium humidity of 85~.
The packaging system of the combination of laundry
detergent and cleaning product tablets) and packaging
system has, in accordance with the invention, a
moisture vapor transmission rate of from 0.1 g/m2/day
to less than 20 g/m2/day when said packaging system is
stored at 23°C and a relative equilibrium humidity of
85~. These temperature and humidity conditions are the
test conditions specified in DIN Standard 53122, which
allows minimal deviations (23 t 1°C, 85 ~ 2~ relative
humidity). The moisture vapor transmission rate of a
given packaging system or material may be determined in
accordance with further standard methods and is also
described, for example, in ASTM Standard E-96-53T
("Test for measuring water vapor transmission of
materials in sheet form") and in TAPPI Standard T464
m-45 ("Water vapor permeability of sheet materials at
high temperature and humidity"). The measurement
CA 02311989 2000-06-19
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principle of common techniques is based on the water
uptake of anhydrous calcium chloride which is stored in
a container in the appropriate atmosphere, the
container being closed at the top face with the
material to be tested. From the surface area of the
container closed with the material to be tested
(permeation area), the weight gain of the calcium
chloride, and the exposure time, the moisture vapor
transmission rate may be calculated as follows:
~,R~ 24~I0000 _ x ~g~m~ ~24jr~
A ly
where A is the area of the material to be tested in
cm2, x is the weight gain of the calcium chloride in g,
and y is the exposure time in h.
The relative equilibrium humidity, often referred to as
"relative atmospheric humidity", is 85~ at 23°C when
the moisture vapor transmission rate is measured in the
context of the present invention. The ability of air to
accommodate water vapor increases with temperature up
to a particular maximum content, the so-called
saturation content, and is specified in g/m3. For
example, 1 m3 of air at 17° is saturated with 14.4 g of
water vapor; at a temperature of 11°, saturation is
rcarhar~ W;rr ;»~t 1o a of water vapor. The relative
atmospheric humidity is the ratio, expressed as a
percentage, of the actual water vapor content to the
saturation content at the prevailing temperature. If,
for example, air at 17° contains 12 g/m3 water vapor,
then the relative atmospheric humidity (RH) -
(12/14.4)~100 = 83~. If this air is cooled, then
saturation (100 RH) is reached at what is known as the
dew point (in the example: 14°), i.e., on further
cooling a precipitate is formed in the form of mist
CA 02311989 2000-06-19
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(dew). The humidity is determined quantitatively using
hygrometers and psychrometers.
The relative equilibrium humidity of 85% at 23°C can be
established precisely, for example, in laboratory
chambers with humidity control, to +/-2% RH depending
on the type of apparatus. In addition, constant and
well-defined relative atmospheric humidifies are formed
in closed systems at a given temperature over saturated
solutions of certain salts, these humidifies deriving
from the phase equilibrium between water partial
pressure, saturated solution, and sediment.
The combinations of the invention, comprising laundry
detergent and cleaning product tablets and packaging
system, may of course in turn be packaged in secondary
packaging, examples being cardboard packaging systems
or trays, there being no need to impose further
requirements on the secondary packaging. The secondary
packaging, accordingly, is possible but not necessary.
Packaging systems which are preferred in the context of
the present invention have a moisture vapor
transmission rate of from 0.5 g/m2/day to less than
15 g/mz/day.
Depending on the embodiment of the invention, the
packaging system of the combination of the invention
contains one or more laundry detergent and cleaning
product tablets. In accordance with the invention it is
preferred either to design a tablet such that it
comprises one application unit of the laundry detergent
and cleaning product, and to package this tablet
individually, or to pack into one packaging unit the
number of tablets which totals one application unit. In
the case of an intended dose of 80 g of laundry
detergent and cleaning product, therefore, it is
CA 02311989 2000-06-19
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possible in accordance with the invention to produce
and package individually one laundry detergent and
cleaning product tablet weighing 80 g, but in
accordance with the invention it is also possible to
package two laundry detergent and cleaning product
tablets each weighing 40 g into one pack in order to
arrive at a combination in accordance with the
invention. This principle can of course be extended, so
that, in accordance with the invention, combinations
may also comprise three, four, five or even more
laundry detergent and cleaning product tablets in one
packaging unit. Of course, two or more tablets in a
pack may have different compositions. In this way it is
possible to separate certain components spatially from
one another in order, for example, to avoid stability
problems.
The packaging system of the combination of the
invention may consist of a very wide variety of
materials and may adopt any desired external forms. For
reasons of economy and of greater ease of processing,
however, preference is given to packaging systems in
which the packaging material has a low weight, is easy
to process, and is inexpensive. In combinations which
are preferred in accordance with the invention, the
packaging system consists of a bag or pouch of single-
layer or laminated paper and/or polymer film.
The laundry detergent and cleaning product tablets may
be filled unsorted, i.e., as a loose heap, into a pouch
made of said materials. On esthetic grounds and for the
purpose of sorting the combinations into secondary
packaging, however, it is preferred to fill the laundry
detergent and cleaning product tablets individually, or
sorted into groups of two or more, into bags or
pouches. For individual application units of the
laundry detergent and cleaning product tablets which
CA 02311989 2000-06-19
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are located in a bag or pouch, a term which has become
established in the art is that of the "flow pack". Flow
packs of this kind may optionally then be packaged -
preferably sorted in turn - into outer packaging, which
underscores the compact form of the tablet.
The single-layer or laminated paper or polymer film
bags or pouches preferred for use as packaging systems
may be designed in a very wide variety of ways: for
example, as inflated pouches without a center seam or
as pouches with a center seam which are sealed by means
of heat, adhesives, or adhesive tapes. Single-layer
pouch and bag materials include the known papers, which
may if appropriate be impregnated, and also polymer
films, which may if appropriate be coextruded. Polymer
films that can be used as a packaging system in the
context of the present invention are specified, for
example, in Hans Domininghaus, "Die Kunststoffe and
ihre Eigenschaften", 3rd edition, VDI Verlag,
Diisseldorf, 1988, page 193. Figure 111 shown therein
also gives indications of the water vapor permeability
of the materials mentioned.
Combinations which are particularly preferred in the
context of the present invention comprise as packaging
system a bag or pouch of single-layer or laminated
polymer film having a thickness of from 10 to 200 Vim,
preferably from 20 to 100 Vim, and in particular from 25
to 50 ~tm.
Although it is possible in addition to the
abovementioned films and papers to use wax-coated
papers in the form of cardboard packaging as a
packaging system for the laundry detergent and cleaning
product tablets, it is preferred in the context of the
present invention for the packaging system not to
comprise any cardboard boxes made of wax-coated paper.
CA 02311989 2000-06-19
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In the context of the present invention, the term
"packaging system" always relates to the primary
packaging of the tablets, i.e., to the packaging whose
inner face is in direct contact with the tablet
surface. No requirements whatsoever are imposed on any
optional secondary packaging, so that all customary
materials and systems can be used in this case.
As already mentioned earlier on above, the laundry
detergent and cleaning product tablets of the
combination of the invention comprise further
ingredients of laundry detergents and cleaning
products, in varying amounts, depending on their
intended use. Independently of the intended use of the
tablets, it is preferred in accordance with the
invention for the laundry detergent and cleaning
product tablets) to have a relative equilibrium
humidity of less than 30~ at 35°C.
The relative equilibrium humidity of the laundry
detergent and cleaning product tablets may be
determined in accordance with common methods, the
following procedure having been chosen in the context
of the present investigations: a water-impermeable
1 liter vessel with a lid which has a closable opening
for the introduction of samples was filled with a total
of 300 g of laundry detergent and cleaning product
tablets and held at a constant 23°C for 24 h in order
to ensure a uniform temperature of vessel and
substance. The water vapor pressure in the space above
the tablets can then be determined using a hygrometer
(Hygrotest 6100, Testoterm Limited, UK). The water
vapor pressure is then measured every 10 minutes until
two succeeding values show no deviation (equilibrium
humidity). The abovementioned hygrometer permits direct
display of the recorded values in ~ relative humidity.
CA 02311989 2000-06-19
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Likewise preferred are embodiments of the combination
of the invention wherein the packaging system is of
resealable configuration. Combinations wherein the
packaging system has a microperforation may also be
realized advantageously in accordance with the
invention.
The present invention additionally provides a method of
washing textiles in a domestic washing machine, which
comprises placing one or more tablets of the invention
in the dispenser drawer of the washing machine and
running a wash program in the course of which the
tablet or tablets is or are rinsed in.
The tablet or tablets need not, however, be metered via
the dispenser drawer but instead may also be placed
directly in the wash drum. In this case, firstly, a
dosing aid - for example, a dosing net - may be used;
alternatively, the tablets may be placed directly on
20, the laundry in the drum without a dosing aid. The
present invention therefore likewise provides a method
of washing textiles in a domestic washing machine,
which comprises placing one or more detergent tablets
of the invention, with or without a dosing aid, in the
wash drum of the washing machine and running a wash
program in the course of which the tablet or tablets is
or are dissolved.
As mentioned earlier on above, detergent tablets for
machine dishwashing may also be produced by the process
of the invention. Accordingly, the present invention
additionally provides a method of cleaning tableware
and kitchenware in a dishwashing machine, which
comprises placing one or more detergent tablets of the
invention in the dispensing cup of the dishwasher and
running a wash program in the course of which the
CA 02311989 2000-06-19
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dispensing cup opens and the tablet or tablets is or
are dissolved.
With the dishwashing method of the invention as well it
is possible to do without the dosing cup and to place
the tablet or tablets of the invention in, for example,
the cutlery basket. Here again, of course, the use of a
dosing aid, for example, a basket insert which is
placed in the washing compartment, is possible without
problems. Accordingly, the present invention further
provides a method of cleaning tableware and kitchenware
in a dishwashing machine, which comprises placing one
or more detergent tablets of the invention, with or
without a dosing aid, in the washing compartment of the
dishwasher and running a wash program in the course of
which the tablet or tablets is or are dissolved.
The invention may be varied in any number of ways as
would be apparent to a person skilled in the art and
all obvious equivalents and the like are meant to fall
within the scope of this description and claims. The
description is meant to serve as a guide to interpret
the claims and not to limit them unnecessarily.
