Note: Descriptions are shown in the official language in which they were submitted.
CA 02318000 2000-09-11
DETERGENT COMPONENT WITH FINELY DIVIDED SOLIDS
Field of the Invention
The present invention is situated in the field of machine
dishwashing compositions for customary domestic
dishwashing machines. It relates to detergent components
for use in machine dishwashing compositions (MDWCs) and
also to detergent compositions and detergent tablets
which comprise such components.
Background of the Invention
The machine cleaning of kitchen- and tableware in
domestic dishwashing machines normally involves a prewash
cycle, a main wash cycle and a rinse cycle, interrupted
by intermediate wash cycles. With the majority of
machines, the prewash cycle may be selected for highly
soiled ware, but is selected by the user only in
exceptional cases, so that in the majority of machines a
main wash cycle, an intermediate wash cycle with clean
water, and a rinse cycle are conducted. The temperature
of the main wash cycle varies, according to machine type
and program step choice, between 40 and 65°C. In the
rinse cycle, rinse aids are added from a dosing tank
within the machine, these rinse aids normally comprising
nonionic surfactants as their principal constituent.
Rinse aids of this kind are in liquid form and have been
widely described in the prior art. Their primary object
is to prevent lime spots and deposits on the cleaned
ware. Besides water and low-foaming nonionic surfactants,
these rinse aids often also include hydrotropes, pH
modifiers such as citric acid, or scale-inhibiting
polymers.
The reservoir tank within the dishwashing machine has to
be filled up at regular intervals with rinse aid, one
fill being sufficient for from 10 to 50 cycles, depending
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on machine type. If the user forgets to fill up the tank,
then glasses, in particular, acquire unsightly lime spots
and deposits. In the prior art, therefore, there exist a
number of proposals for integrating a rinse aid into the
machine dishwashing detergent.
For instance, European Patent Application EP-A-0 851 024
(Unilever) describes two-layer detergent tablets whose
first layer comprises peroxy bleach, builder and enzyme
while the second layer comprises acidifiers, a continuous
medium having a melting point of between 55 and 70°C and
scale inhibitors. It is intended that the high-melting
continuous medium will effect retarded release of the
acids) and scale inhibitors) to produce a rinse aid
effect. This document makes no mention of powder-form
machine dishwashing compositions or rinse aid systems
comprising surfactant.
The prior German Patent Application DE 198 51 426.3
(Henkel KGaA) describes a process for producing
multiphase detergent tablets which comprises compressing
a particulate premix into tablets which have a
depression, which is subsequently filled with a
separately prepared melt comprising a meltable substance
and one or more active substances suspended or dispersed
therein. The teaching of this document is also tied to
the tablet commercial form.
The melt suspensions or melt emulsions disclosed in the
last-mentioned document, however, especially when
surfactants are incorporated as an active substance, have
a long-term stability which is in need of improvement.
After the emulsion has cooled, the meltable substances
are supposed to enclose the active substance and protect
it against premature release. If the emulsion is not
sufficiently stable, it undergoes partial separation in
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the melted state prior to dosing, leading to dosing
inaccuracies. Slightly more stable emulsions can be dosed
but undergo partial separation prior to solidification,
so that the active substance is released early on in the
cleaning operation. Proposing a solution, this document
discloses the use of diverse auxiliaries/stabilizers.
where solids are mentioned, however, nothing is said
about their physical properties.
Sux~nary of the Invention
It is an object of the present invention to further
develop the teaching of prior German Patent Application
DE 198 51 426.3 and to provide mixtures which possess
long-term stability, which have no propensity to separate
in the course of dosing and cooling and which,
accordingly, give effective and stable detergent
components. These long-term-stable mixtures and the
detergent components prepared from them ought to make it
possible to utilize all known advantages of the
controlled release of ingredients, especially a clear-
rinse effect, both for powder-form detergents and for
detergent tablets.
It has now been found that separation-stable melts may be
prepared from meltable hydrophobic substances having
melting points above 30°C, surfactants) and, optionally,
further ingredients such as dyes and fragrances, etc., if
these mixtures contain at least 0.1% by weight of finely
divided solid (s) .
The melting point of such mixtures may be tailored to the
desired value by the nature and amount of the individual
ingredients, in particular by way of the melting points
and amounts of meltable substances) and surfactant(s).
Above the melting point, the mixtures are stable toward
separation; below the melting point there exist
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solidified mixtures in any desired shape, which in the
context of the present specification are referred to as
detergent components.
The present invention provides a detergent component
comprising
a) from 10 to 89.9% by weight of surfactant(s),
b) from 10 to 89.9% by weight of meltable
substances) having a melting point above 30°C
and a water solubility of less than 20 g/1 at
20°C,
c) from 0.1 to 15% by weight of one or more solids,
d) from 0 to 15% by weight of further active
substances and/or auxiliaries,
with the proviso that at least 90% by weight of the
particles c) have sizes below 300 ~,m.
Detailed Description of the Invention
In the context of the present application, the term
"detergent component" denotes solidified mixtures of the
ingredients a) to d), irrespective of their shape.
"Detergent components" in the sense of the present
application therefore include, for example, flakes,
prills, pellets, tablet regions, tablets per se, etc. In
order to obtain an extremely fine distribution of the
ingredient a) in a matrix of the ingredient b) , both the
ingredients are melted, separately or mixed with one
another, combined if appropriate, and stirred together
with the addition of c) and the optional addition of d) .
The melt suspension. or melt emulsion prepared in this
way, sometimes referred to below simply as "mixture", may
then be converted to the desired form.
Preferred detergent components comprise as ingredient a)
from 15 to 80, preferably from 20 to 70, with particular
preference from 25 to 60, and in particular from 30 to
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50% by weight of surfactant(s). All surfactants from the
groups of the anionic, nonionic, cationic, and amphoteric
surfactants may be used, preferred detergent components
comprising as ingredient a) anionic and/or nonionic
surfactant(s), preferably nonionic surfactant(s).
Anionic surfactants used are, for example, those of the
sulfonate and sulfate type. Preferred surfactants of the
sulfonate type are C9_13 alkylbenzenesulfonates,
olefinsulfonates, i.e., mixtures of alkenesulfonates and
hydroxyalkanesulfonates, and also disulfonates, as are
obtained, for example, from Cla-is monoolefins having a
terminal or internal double bond by sulfonating with
gaseous sulfur trioxide followed by alkaline or acidic
hydrolysis of the sulfonation products. Also suitable are
alkanesulfonates, which are obtained from Clz-is 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.
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Preferred alk(en)yl sulfates are the alkali metal salts,
and especially the sodium salts, of the sulfuric
monoesters of Clz-Cls 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 monoesters of secondary alcohols of
these chain lengths. Preference is also given to
alk(en)yl sulfates of said chain length which contain a
synthetic straight-chain alkyl radical prepared on a
petrochemical basis, these sulfates possessing
degradation properties similar to those of the
corresponding compounds based on fatty-chemical raw
materials. From a detergents standpoint, the Clz-Cls alkyl
sulfates and Clz-Cls alkyl sulfates, and also C14-Cls alkyl
sulfates, are preferred. In addition, 2,3-alkyl sulfates,
which may be 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-le fatty alcohols containing
from 1 to 4 EO. Because of their high foaming behavior
they are used in detergents 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 Cs_lg fatty alcohol radicals or
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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 having preferably 8 to 18 carbon atoms in the
alk(en)yl chain, or salts thereof.
Further suitable anionic surfactants are, in particular,
soaps. Suitable soaps include saturated fatty acid soaps,
such as the salts of lauric acid, myristic acid, palmitic
acid, stearic acid, hydrogenated erucic acid and behenic
acid, and, in particular, mixtures of soaps derived from
natural fatty acids, e.g., coconut, palm kernel or tallow
fatty acids.
The anionic surfactants, including the soaps, may be
present in the form of their sodium, potassium or
ammonium salts and also as soluble salts of organic
bases, such as mono-, di- or triethanolamine. Preferably,
the anionic surfactants are in the form of their sodium
or potassium salts, in particular in the form of the
sodium salts.
Nonionic surfactants used are preferably alkoxylated,
advantageously ethoxylated, especially primary, alcohols
having preferably 8 to 18 carbon atoms and on average
from 1 to 12 mol of ethylene oxide (EO) per mole of
alcohol, in which the alcohol radical may be linear or,
preferably, methyl-branched in position 2 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
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ethoxylates containing linear radicals from alcohols of
natural origin having 12 to 18 carbon atoms, e.g., from
coconut, palm, tallow fatty or oleyl alcohol and on
average from 2 to 8 EO per mole of alcohol. Preferred
ethoxylated alcohols include, for example, Clz-14 alcohols
containing 3 EO or 4 EO, C9_11 alcohol containing 7 EO,
C13-is alcohols containing 3 EO, 5 EO, 7 EO or 8 EO, Clz-is
alcohols containing 3 EO, 5 EO or 7 EO, and mixtures
thereof, such as mixtures of Clz-i4 alcohol containing 3 EO
and Clz-la alcohol containing 5 EO. The stated degrees of
ethoxylation represent statistical mean values, which for
a specific product may be an integer or a fraction.
Preferred alcohol ethoxylates have a narrowed homolog
distribution (narrow range ethoxylates, NREs). In
addition to these nonionic surfactants it is also
possible to use fatty alcohols containing more than 12
EO. Examples thereof are tallow fatty alcohol containing
14 EO, 25 EO, 30 EO or 40 EO.
As further nonionic surfactants, furthermore, use may
also be made of alkyl glycosides of the general formula
RO(G)X, where R is a primary straight-chain or methyl-
branched aliphatic radical, especially an aliphatic
radical methyl-branched in position 2, containing 8 to
22, preferably 12 to 18, carbon atoms, and G is the
symbol representing a glycose unit having 5 or 6 carbon
atoms, preferably glucose. The degree of oligomerization,
x, which indicates the distribution of monoglycosides and
oligoglycosides, is any desired number between 1 and 10;
preferably, x is from 1.2 to 1.4.
A further class of nonionic surfactants used with
preference, which are used either as sole nonionic
surfactant or in combination with other nonionic
surfactants, are alkoxylated, preferably ethoxylated, or
ethoxylated and propoxylated, fatty acid alkyl esters,
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preferably having 1 to 4 carbon atoms in the alkyl chain,
especially fatty acid methyl esters.
Nonionic surfactants of the amine oxide type, examples
being N-cocoalkyl-N,N-dimethylamine oxide and
N-tallowalkyl-N,N-dihydroxyethylamine oxide, and of the
fatty acid alkanolamide type, may also be suitable. The
amount of these nonionic surfactants is preferably not
more than that of the ethaxylated fatty alcohols, in
particular not more than half thereof.
Further suitable surfactants are polyhydroxy fatty acid
amides of the formula (I)
Rl
R-CO-N-[Z] (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)
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R 1-Q _R?
R-CO-N-[Z] (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 RZ is a linear, branched or cyclic alkyl
radical or an aryl radical or an oxyalkyl radical having
1 to 8 carbon atoms, preference being given to C1_4 alkyl
radicals or phenyl radicals, and [Z] is a linear
polyhydroxyalkyl radical whose alkyl chain is substituted
by at least two hydroxyl groups, or alkoxylated,
preferably ethoxylated or propoxylated, derivatives of
said radical.
[Z] is preferably obtained by reductive amination of a
reduced sugar, e.g., glucose, fructose, maltose, lactose,
galactose, mannose or xylose. The N-alkoxy- or N-aryloxy-
substituted compounds may be converted to the desired
polyhydroxy fatty acid amides by reaction with fatty acid
methyl esters in the presence of an alkoxide as catalyst.
Preferred surfactants used are low-foaming nonionic
surfactants. With particular preference, the detergent
components of the invention for machine dishwashing
comprise nonionic surfactants, especially nonionic
surfactants from the group of the alkoxylated alcohols.
Nonionic surfactants used are preferably alkoxylated,
advantageously ethpxylated, 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
CA 02318000 2000-09-11
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, Cia-i4 alcohols
containing 3 EO or 4 EO, C9_11 alcohol containing 7 EO,
Ci3-is alcohols containing 3 EO, 5 EO, 7 EO or 8 EO, C12_le
alcohols containing 3 EO, 5 EO or 7 EO, and mixtures
thereof, such as mixtures of Clz-14 alcohol containing 3 EO
and Clz-is alcohol containing 5 EO. The stated degrees of
ethoxylation represent statistical mean values, which for
a specific product may be an integer or a fraction.
Preferred alcohol ethoxylates have a narrowed homolog
distribution (narrow range ethoxylates, NREs). In
addition to these nonionic surfactants it is also
possible to use fatty alcohols containing more than 12
EO. Examples thereof are tallow fatty alcohol containing
14 EO, 25 EO, 30 EO or 40 EO.
Especially preferred detergent components of the
invention are those that comprise a nonionic surfactant
having a melting point above room temperature.
Accordingly, preferred detergent components comprise as
ingredient a) nonionic surfactants) having a melting
point above 20°C, preferably above 25°C, with particular
preference between 25 and 60°C, and in particular between
26.6 and 43.3°C.
Suitable nonionic surfactants having melting or softening
points within the stated temperature range are, for
example, low-foaming nonionic surfactants which may be
solid or highly viscous at room temperature. If nonionic
surfactants which are highly viscous at room temperature
are used, then it is preferred that they have a viscosity
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above 20 Pas, preferably above 35 Pas, and in particular
above 40 Pas. Also preferred are nonionic surfactants
which possess a waxlike consistency at room temperature.
Preferred nonionic surfactants for use that are solid at
room temperature originate from the groups of alkoxylated
nonionic surfactants, especially the ethoxylated primary
alcohols, and mixtures of these surfactants with
surfactants of more complex construction such as
polyoxypropylene/polyoxyethylene/ polyoxypropylene
(PO/EO/PO) surfactants. Such (PO/EO/PO) nonionic
surfactants are notable, furthermore, for good foam
control.
In one preferred embodiment of the present invention, the
nonionic surfactant having a melting point above room
temperature is an ethoxylated nonionic surfactant
originating from the reaction of a monohydroxy alkanol or
alkylphenol having 6 to 20 carbon atoms with preferably
at least 12 mol, with particular preference at least 15
mol, in particular at least 20 mol, of ethylene oxide per
mole of alcohol or alkylphenol, respectively.
A particularly preferred nonionic surfactant for use that
is solid at room temperature is obtained from a straight-
chain fatty alcohol having 16 to 20 carbon atoms (Cls-ao
alcohol), preferably a C18 alcohol, and at least 12 mol,
preferably at least 15 mol, and in particular at least 20
mol of ethylene oxide. Of these, the so-called "narrow
range ethoxylates" (see above) are particularly
preferred.
Accordingly, particularly preferred detergent components
of the invention comprise as ingredient a) ethoxylated
nonionic surfactant (s) obtained from Cs-20
monohydroxyalkanols or C6_2o alkylphenols or Cls-ao fatty
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alcohols and more than 12 mol, preferably more than
15 mol, and in particular more than 20 mol, of ethylene
oxide per mole of alcohol.
The nonionic surfactant which is solid at room
temperature preferably further possesses propylene oxide
units in the molecule. Preferably, such PO units account
for up to 25% by weight, with particular preference up to
20% by weight, and in particular up to 15% by weight, of
the overall molecular mass of the nonionic surfactant.
Particularly preferred nonionic surfactants are
ethoxylated monohydroxy alkanols or alkylphenols, which
additionally comprise polyoxyethylene-polyoxypropylene
block copolymer units. The alcohol or alkylphenol moiety
of such nonionic surfactant molecules in this case makes
up preferably more than 30% by weight, with particular
preference more than 50% by weight, and in particular
more than 70% by weight, of the overall molar mass of
such nonionic surfactants. Preferred detergent components
comprise as ingredient a) ethoxylated and propoxylated
nonionic surfactants wherein the propylene oxide units in
the molecule account for up to 25% by weight, preferably
up to 20% by weight, and in particular up to 15% by
weight, of the overall molecular mass of the nonionic
surfactant.
Further nonionic surfactants whose use is particularly
preferred, with melting points above room temperature,
contain from 40 to 70% of a polyoxypropylene/
polyoxyethylene/polyoxypropylene block polymer blend
which comprises 75% by weight of an inverted block
copolymer of polyoxyethylene and polyoxypropylene
containing 17 mol of ethylene oxide and 44 mol of
propylene oxide and 25% by weight of a block copolymer of
polyoxyethylene and polyoxypropylene, initiated with
trimethylolpropane and containing 24 mol of ethylene
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oxide and 99 mol of propylene oxide per mole of
trimethylolpropane.
Nonionic surfactants which may be used with particular
preference are, for example, obtainable under the name
Poly Tergent~ SLF-18 from the company Olin Chemicals.
Further preferred detergent components of the invention
comprise as ingredient a) nonionic surfactants of the
formula
R10 [CH2CH (CH3) O] x [CHzCH20] Y [CHzCH (OH) R2]
in which R1 is a linear or branched aliphatic hydrocarbon
radical having 4 to 18 carbon atoms, or mixtures thereof,
RZ is a linear or branched hydrocarbon radical having 2
to 26 carbon atoms, or mixtures thereof, and x is between
0.5 and 1.5, and y is at least 15.
Further nonionic surfactants which may be used with
preference are the endgroup-capped poly(oxyalkylated)
nonionic surfactants of the formula
R10 [CHZCH (R3) O] X [CH2] kCH (OH) [CH2] ~ORz
in which R1 and RZ are linear or branched, saturated or
unsaturated, aliphatic or aromatic hydrocarbon radicals
having 1 to 3 0 carbon atoms , R3 is H or a methyl , ethyl ,
n-propyl, isopropyl, n-butyl, 2-butyl or 2-methyl-2-butyl
radical, x is between 1 and 30, k and j are between 1 and
12, preferably between 1 and 5. Where x >_ 2, each R3 in
the above formula may be different. R1 and RZ are
preferably linear or branched, saturated or unsaturated,
aliphatic or aromatic hydrocarbon radicals having 6 to 22
carbon atoms, radicals having 8 to 18 carbon atoms being
particularly preferred. For the radical R3, H, -CH3 or -
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CHzCH3 are particularly preferred. Particularly preferred
values for x lie within the range from 1 to 20, in
particular from 6 to 15.
As described above, each R3 in the above formula may be
different if x >_ 2. By this means it is possible to vary
the alkylene oxide unit in the square brackets. If x, for
example, is 3, the radical R3 may be selected in order to
form ethylene oxide (R3 - H), or propylene oxide (R3 -
CH3) units, which may be added on to one another in any
sequence, examples being (EO)(PO)(EO), (EO)(EO)(PO),
(EO) (EO) (EO) , (PO) (EO) (PO) , (PO) (PO) (EO) and
(PO)(PO)(PO). The value of 3 for x has been chosen by way
of example in this case and it is entirely possible for
it to be larger, the scope for variation increasing as
the values of x go up and embracing, for example, a large
number of (EO) groups, combined with a small number of
(PO) groups, or vice versa.
Particularly preferred endgroup-capped poly(oxyalkylated)
alcohols of the above formula have values of k = 1 and j
- 1, thereby simplifying the above formula to
R10 [ CHZCH ( R3 ) O ] XCHZCH ( OH ) CHzOR2 .
In the last-mentioned formula, R1, RZ and R3 are as
defined above and x stands for numbers from 1 to 30,
preferably from 1 to 20, and in particular from 6 to 18.
Particular preference is given to surfactants wherein the
radicals R1 and R2 have 9 to 14 carbon atoms, R3 is H, and
x adopts values from 6 to 15.
Summarizing the last-mentioned statements, preference is
given to detergent components of the invention comprising
as ingredient a) endgroup-capped poly(oxyalkylated)
nonionic surfactants of the formula
CA 02318000 2000-09-11
R10 [CHZCH (R3) O] X [CHZ] kCH (OH) [CHZ] ~ORz
in which R1 and Rz are linear or branched, saturated or
unsaturated, aliphatic or aromatic hydrocarbon radicals
having 1 to 3 0 carbon atoms, R3 is H or a methyl , ethyl ,
n-propyl, isopropyl, n-butyl, 2-butyl or 2-methyl-2-butyl
radical, x is between 1 and 30, k and j are between 1 and
12, preferably between 1 and 5, particular preference
being given to surfactants of the type
R10 [ CHZCH ( R3 ) O ] XCHZCH ( OH ) CH20R2
where x is from 1 to 30, preferably from 1 to 20, and in
particular from 6 to 18.
As ingredient b), the detergent components of the
invention comprise one or more meltable substances which
have a melting point above 30°C, and possess little or no
solubility in water. These substances form the "matrix"
in which the ingredient a) of the detergent components of
the invention is present in fine distribution, this
distribution being stabilized by means of the special
ingredient c). In the context of the present invention,
preferred detergent components are those comprising as
ingredient b) from 15 to 85, preferably from 20 to 80,
with particular preference from 25 to 75, and in
particular from 30 to 70% by weight of meltable
substance ( s ) .
The temperature at which the detergent components of the
invention release the ingredients a) and, optionally, d)
may be varied within wide limits through the choice of
the melting point of the ingredient b). Below this
temperature, the other ingredients are protected against
ambient influences.
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The meltable substances used in the detergent components
of the invention are subject to a variety of
requirements, relating on the one hand to the melting
behavior or, respectively, solidification behavior but on
the other hand also to the material properties of the
melt in the solidified state, i.e., in the detergent
components of the invention. Since the detergent
component is to be durably protected against ambient
influences in transit or storage, the meltable substance
must possess a high stability with respect, for example,
to impacts occurring in the course of packaging or
transport. The meltable substance should, therefore, have
either at least partially elastic or at least plastic
properties, in order to react by elastic or plastic
deformation to any impact that does occur, and not to
become crushed. The meltable substance should have a
melting range (solidification range) situated within a
temperature range in which other ingredients of the
detergent components of the invention are not exposed to
any excessive thermal load. On the other hand, however,
the melting range must be sufficiently high still to
offer effective protection for the active substances at
least at slightly elevated temperature. In accordance
with the invention, the meltable substances have a
melting point above 30°C, preference being given to
detergent components comprising only meltable substances
having melting points above 40°C, preferably above 45°C,
and in particular above 50°C. Particularly preferred
detergent components comprise as ingredient b) one or
more substances having a melting range between 30 and
100°C, preferably between 40 and 80°C, and in particular
between 50 and 75°C.
It has proven advantageous for the meltable substance not
to exhibit a sharply defined melting point, as
encountered commonly with pure, crystalline substances,
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but instead to have a melting range which covers, in some
cases, several degrees Celsius.
The meltable substance preferably has a melting range
which lies between about 52.5°C and about 80°C. In the
present case that means that the melting range occurs
within the stated temperature interval, and does not
denote the width of the melting range. The width of the
melting range is preferably at least 1°C, more preferably
from about 2 to about 3°C.
The abovementioned properties are in general possessed by
what are called waxes. The term "waxes" is applied to a
range of natural or synthetic substances which melt
without decomposition, generally at above 50°C, and are
of comparatively low viscosity, without stringing, at
just a little above the melting point. They have a highly
temperature-dependent consistency and solubility.
According to their origin, the waxes are divided into
three groups: the natural waxes, chemically modified
waxes, and the synthetic waxes.
The natural waxes include, for example, plant waxes such
as candelilla wax, carnauba wax, Japan wax, esparto grass
wax, cork wax, guaruma wax, rice germ oil wax, sugar cane
wax, ouricury wax, or montan wax, animal waxes such as
beeswax, shellac wax, spermaceti, lanolin (wool wax), or
uropygial grease, mineral waxes such as ceresin or
ozokerite (earth wax), or petrochemical waxes such as
petrolatum, paraffin waxes or microcrystalline waxes.
The chemically modified waxes include, for example, hard
waxes such as montan ester waxes, sassol waxes, or
hydrogenated jojoba waxes.
18
CA 02318000 2000-09-11
By synthetic waxes are meant, in general, polyalkylene
waxes or polyalkylene glycol waxes. As coating materials
it is also possible to use compounds from other classes
of substance which meet the stated requirements in terms
of softening point. Examples of synthetic compounds which
have proven suitable are higher esters of phthalic acid,
especially dicyclohexyl phthalate, which is available
commercially under the name Unimoll~ 66 (Bayer AG). Also
suitable are synthetically prepared waxes from lower
carboxylic acids and fatty alcohols, an example being
dimyristyl tartrate, which is available under the name
Cosmacol~ ETLP (Condea).
Preferably, the coating substance present in the
detergent components of the invention includes a paraffin
wax fraction. That means that at least 10% by weight of
the total meltable substances present, preferably more,
consist of paraffin wax. Particularly suitable are
paraffin wax contents (based on the total amount of
meltable substance) of approximately 12.5% by weight,
approximately 15% by weight or approximately 20% by
weight; even higher proportions, of, for example, more
than 30% by weight may be particularly preferred. In one
particular embodiment of the invention, the total amount
of the meltable substance used consists exclusively of
paraffin wax.
Relative to the other, natural waxes mentioned, paraffin
waxes have the advantage in the context of the present
invention that in an alkaline detergent environment there
is no hydrolysis of the waxes (as is to be expected, for
example, with the wax esters), since paraffin wax
contains no hydrolyzable groups.
Paraffin waxes consist primarily of alkanes, with small
fractions of isoalkanes and cycloalkanes. The paraffin
19
CA 02318000 2000-09-11
for use in accordance with the invention preferably
contains essentially no constituents having a melting
point above 70°C, with particular preference above 60°C.
Below this melting temperature, in the detergent liquor,
fractions of high-melting alkanes in the paraffin may
leave unwanted wax residues on the surfaces to be cleaned
or on the ware to be cleaned. Wax residues of this kind
lead in general to an unattractive appearance of the
cleaned surface and should therefore be avoided.
Preferred detergent components comprise as ingredient b)
at least one paraffin wax having a melting range of from
30°C to 65°C.
Preferably, the amount of alkanes, isoalkanes and
cycloalkanes which are solid at ambient temperature
(generally from about 10 to about 30°C) in the paraffin
wax used is as high as possible. The larger the amount of
solid wax constituents in a wax at room temperature, the
more useful that wax is in the context of the present
invention. As the proportion of solid wax constituents
increases, there is an increase in the resistance of the
detergent component to impacts or friction against other
surfaces, resulting in a longer-lasting protection of the
active substances. High proportions of oils or liquid wax
constituents may cause weakening as a result of which
pores are opened and the active substances are exposed to
the ambient influences mentioned at the outset.
In addition to paraffin, the meltable substance may
further comprise one or more of the abovementioned waxes
or waxlike substances. Preferably, the mixture forming
the meltable substance should be such that the detergent
component is at least substantially water-insoluble. At a
temperature of about 30°C, the solubility in water should
CA 02318000 2000-09-11
not exceed about 10 mg/1 and preferably should be below
mg/l.
In any case, however, the coating should preferably have
5 as low a solubility in water as possible, even in water
at elevated temperature, in order as far as possible to
avoid temperature-independent release of the active
substances. Preferred detergent components are,
therefore, those wherein the water solubility of
ingredient b) at 20°C is less than 15 g/1, preferably
less than 10 g/l, with particular preference less than
5 g/1, and in particular less than 2 g/l. It is
particularly preferred if the water solubility of
ingredient b) at 20°C is below the measurement limit,
i.e., if substance b) is to all intents and purposes
"insoluble" in water.
As ingredient c), the detergent components of the
invention contain from 0.1 to 15% by weight of one or
more solids, at least 90% by weight of the particles of
c) having sizes below 300 Vim. In preferred detergent
components, the amounts of c) lie within a narrower
range, and the particle sizes as well are also,
preferably, even finer. Thus, firstly, preference is
given to detergent components comprising ingredient c) in
amounts of from 0.15 to 12.5, preferably from 0.2 to 10,
with particular preference from 0.25 to 7.5, and in
particular from 0.3 to 5% by weight; secondly, at least
90% by weight of the particles of c) in further-preferred
detergent components have sizes below 200 ~,m, preferably
below 190 Vim, with particular preference below 175 ~,m, in
particular below 150 Vim, and with very particular
preference below 100 Vim.
It is particularly preferred if the ingredient c)
possesses no particles at all having a size above 200 Vim;
21
CA 02318000 2000-09-11
preferably, the particle size is even further below this
limit. In particularly preferred detergent components,
ingredient c) consists entirely of particles having sizes
below 200 Vim, preferably below 175 Vim, with particular
preference below 150 Vim, and in particular below 100 Vim.
Appropriate ingredients c) are all substances which are
solid and which satisfy the aforementioned particle size
criterion. The term "solid" in this context denotes that
the ingredient c) remains solid even at the processing
temperatures of ingredients a) to d) and does not, for
instance, melt during the preparation of melts or become
dissolved in other ingredients. Preference is given to
the use as ingredient c) of substances whose melting
point lies well above the melting point of the detergent
component, for example, at least 10°C above, preferably
at least 25°C above, and in particular at least 50°C
above. It may also be preferable to use substances which
are unmeltable at conventional temperatures as ingredient
c) .
Compounds which have proven particularly suitable as
ingredient c), in addition to inorganic solvents, mineral
substances such as silicates, silicas, alumino-silicates,
organic solids, etc., are the alkali metal salts of
organic acids, preference being given to the sodium and
potassium salts. Examples of suitable organic acids whose
salts are preferred ingredients c) are formic acid,
acetic acid, propionic acid, succinic acid, citric acid,
fumaric acid, oxalic acid, malonic acid, tartaric acid,
etc. Particularly preferred detergent components comprise
as ingredient c) alkali metal salts of organic acids,
preferably alkali metal acetates, and in particular
potassium acetate.
22
CA 02318000 2000-09-11
A further preferred group of substances which may be used
as ingredient c) are clay minerals. In this context, the
natural, or chemically modified, clay minerals may be
used. Particularly preferred clay minerals are the
bentonites, which in the context of the present invention
are highly suitable ingredients c).
Bentonites are impure clays formed through the weathering
of volcanic tuffs. The properties of the bentonites may
be modified to accord with the intended use. Bentonites
occur frequently as a clay constituent in tropical soils
and are extracted as sodium bentonite, for example, in
V,lyoming. Sodium bentonite has the most favorable
performance properties, and so its use is preferred in
the context of the present invention. Naturally occurring
calcium bentonites come, for example, from Mississippi or
Texas, or from Landshut, Germany. The Ca bentonites
obtained from nature are converted artificially, by
exchanging Ca for Na, into the more swellable Na
bentonites.
The principal constituents of the bentonites are formed
by what are known as montmorillonites, which may also be
used in pure form in the context of the present
invention. Montmorillonites are clay minerals which
belong to the phyllosilicates and, among these, to the
dioctahedral smectites, and crystallize in monoclinic
pseudohexagonal forms. Montmorillonites form
predominantly white, grayish white to yellowish
compositions which appear completely amorphous, are
readily friable, swell in water but do not become
plastic, and may be prescribed by the general formulae
A12 [ (OH) 2/Si401o1 ~ nHzO or
A1203 ~ 4Si02 ~ Hz0 ~ nHzO or
A12 [ (OH) 2/Si401o1 (dried at 150°) .
23
CA 02318000 2000-09-11
Montmorillonites possess a three-layer structure
consisting of two tetrahedron layers which are
electrostatically crosslinked via the cations of an
intermediate octahedron layer. The layers are not
connected rigidly but instead are able to swell by
reversible intercalation of water (from 2-7 times the
amount) and other substances such as, for example,
alcohols, glycols, pyridine, a-picoline, ammonium
compounds, hydroxy-aluminosilicate ions, etc. Th.e
formulae indicated above represent only approximate
formulae, since montmorillonites possess a high ion
exchange capacity. Thus A1 may be exchanged for Mg, Fez+,
Fe3+, Zn, Cr, Cu and other ions . As a consequence of such
substitution, there is a resulting negative charge in the
layers, which is compensated by other cations, especially
Na+ and Caz+ .
The structure of the phyllosilicates, in which a central
layer of octahedrally coordinated cations is surrounded
by 2 layers of [(Si,Al)04] tetrahedra, like a sandwich,
may be varied widely by means of numerous substitutions
in the octahedron layer. Thus the octahedron layer may
include, in addition to the usually predominant A13+
(montmorillonite - dioctahedral phyllosilicate), for
example, also Mgz+ (saponite -trioctahedral
phyllosilicate) or Fe3+ (nontronite - dioctahedral
phyllosilicate). Also present, in addition, are cations
such as Znz+ (in the case of sauconite - trioctahedral
phyllosilicate), Niz+ (nickel sauconite - trioctahedral
phyllosilicate), and Li+ (hectorite - trioctahedral
phyllosilicate). Substitutions in the tetrahedron layer
as well may be observed; for instance, Si4+ may be
replaced in part by A13+ (in the case of beidellite -
dioctahedral phyllosiliate) and also by Fe3+ (in the case
of nontronite - dioctahedral phyllosilicate). These
24
CA 02318000 2000-09-11
substitutions result in a charge imbalance, which is
compensated by exchangeable cations, commonly sodium,
calcium and potassium, and also magnesium, between the
layer assemblies.
General formulae which may be given are, therefore, for
dioctahedral phyllosilicates
(K, Ca, Na, Mg) i+ [Si4_X (A1, Fe3+) XOlo] [ (A1, Fe3+) z_Y (Mg, Fez') y+Z
(OH) zl
where i - approximately 0.6 to 0.2 per Olo(OH)2 and also
i - x + y - 2z, and for trioctahedral phyllosilicates
(K, Ca, Na, Mg) 1+ [Si4_XAlXOlol [Mg, Fe2+) 3_y (Al, Fe3+) y_Z (OH) 2l
where i - x - y + 3 z and 0 . 6 < i < 0 . 2 .
Preference is given in the context of the present
invention to the use of bentonites in the classic sense,
i.e., clays having a high montmorillonite content.
Preferred ingredients c) are phyllosilicates having a
montmorillonite content of more than 60% by weight,
preferably more than 75% by weight, and in particular
more than 90% by weight, based in each case on the weight
of the phyllosilicate.
Where this is undesirable for reasons of cost, it is also
possible with preference to use pure montmorillonites.
Detergent components comprising, as bentonite, pure
montmorillonites are likewise preferred in accordance
with the invention.
The layer spacing of phyllosilicates may be modified by
the incorporation of certain compounds, since they are
able - depending on the charge of the elementary layers
and on the intermediate-layer canons - to swell, i.e.,
to increase the basic spacing of their three-layer
assemblies to more than 15 A through intercalation of
CA 02318000 2000-09-11
water molecules or long-chain organic molecules. Thus it
is also possible, in accordance with the invention, to
use chemically modified bentonites as ingredient c),
preference being given to detergent components comprising
bentonites modified by quaternary ammonium compounds.
Detergent components which are preferred in the context
of the present invention comprise as ingredient c)
substances from the group of the clay minerals,
preferably of the chemically modified clay minerals, and
in particular of the hydrophobicized bentonites.
Further solids preferred for use as ingredient c) in the
context of the present invention are ionic surfactants,
provided they have a sufficiently high melting point and
may be brought to the stated particle size range. These
surfactants were described in detail earlier on above.
Fatty alcohol sulfates, in particular, are preferred
ingredients c) , so that preference is given to detergent
components comprising as ingredient c) anionic
surfactant(s), preferably fatty alcohol sulfates, and in
particular Cla-is fatty alcohol sulfates.
The detergent components of the invention may preferably
comprise, as ingredient d), further active substances
and/or auxiliaries from the groups of the dyes,
fragrances, soil release polymers, corrosion inhibitors,
enzymes, bleaches, bleach activators, and complexing
agents, in amounts of from 0 to 10% by weight, preferably
from 0.25 to 7.5% by weight, with particular preference
from 0.5 to 5% by weight, and in particular from 0.75 to
2.5% by weight. Dyes and fragrances, and the other
substances mentioned, are customary ingredients of
detergents and are described in detail later on below.
26
CA 02318000 2000-09-11
As already mentioned earlier on above, the physical and
chemical properties of the detergent components of the
invention may be varied through a suitable choice of the
ingredients a) to d). If, for example, only ingredients
that are liquid at the melting temperature of the mixture
are used, then it is easy to prepare single-phase
mixtures, which are notable for particular storage
stability even in the molten state. The addition of
solids, such as color pigments or substances having
higher melting points, for example, leads automatically
to two-phase mixtures, which, however, likewise exhibit
excellent storage stability and an extremely low
propensity to separate.
Independently of the composition of the detergent
components of the invention, preference is given to
detergent components having a melting point of between 50
and 80°C, preferably between 52.5 and 75°C, and in
particular between 55 and 65°C.
At room temperature, the detergent components of the
invention are solidified mixtures of the abovementioned
ingredients, which may take on any external form
whatsoever. It is also possible to apply the mixtures in
melt form to support materials and so provide support-
based detergent components which consist at room
temperature of support materials) and a melt solidified
on said support materials. Suitable support materials are
all solids which do not soften at the temperature of the
melt and which, furthermore, have a sufficiently great
absorption capacity for the melt. Particularly preferred
support materials are builders, which are described in
detail later on below.
27
CA 02318000 2000-09-11
The present invention additionally provides a process for
preparing particulate detergent components, which
comprises applying a melt comprising
a) from 10 to 89.9% by weight of surfactant(s),
b) from 10 to 89.9% by weight of meltable
substances) having a melting point above 30°C
and a water solubility of less than 20 g/1 at
20°C,
c) from 0.1 to 15% by weight of one or more solids,
d) from 0 to 15% by weight of further active
substances and/or auxiliaries
to one or more support materials and shaping the mixture.
In this process variant, first of all a melt is prepared,
which may include further active substances and
auxiliaries. This melt is applied to a support material
and shaped as a mixture with said support material.
With the abovementioned preparation process for the rinse
aid particles of the invention, preferred process
variants are those wherein the meltable substance
accounts for from 25 to 85% by weight, preferably from 30
to 70% by weight, and in particular from 40 to 50% by
weight of the melt.
The application of the melt to the support material may
be conducted in all customary mixing equipment. The
shaping step for the mixture of melt and support material
is likewise not subject to any technical restriction, so
that here as well the skilled worker is able to select
from the processes customary to him or her. In the course
of experiments conducted by the applicant, processes
which have proven preferable are those wherein the
shaping takes place by granulating, compacting,
pelletizing, extruding, or tableting.
28
CA 02318000 2000-09-11
The process of the invention embraces the application of
melts comprising the ingredients a) to d) to support
materials. In principle, melt and support materials) may
be present in varying amounts in the resultant rinse aid
particles. In preferred processes, the mixture shaped
comprises from 5 to 50% by weight, preferably from 10 to
45% by weight, with particular preference from 15 to 40%
by weight, and in particular from 20 to 35% by weight of
a melt comprising the ingredients a) to d), and from 50
to 95% by weight, preferably from 55 to 90% by weight,
with particular preference from 60 to 85% by weight, and
in particular from 65 to 80% by weight, of support
material ( s ) .
Regarding the ingredients which are used in the process
of the invention and are processed to the support-based
detergent components of the invention, the comments made
earlier on above apply analogously.
The detergent components of the invention may also be
formulated without support material, so that they consist
solely of the ingredients a) to d). In this case, for the
preparation of particulate detergent components of the
invention, grilling, pelletizing and flaking by means of
cooling rolls have proven particularly suitable.
The present invention therefore additionally provides, in
a first embodiment, a process for preparing grilled
detergent components, which comprises spraying a melt
comprising
a) from 10 to 89.9% by weight of surfactant(s),
b) from 10 to 89.9% by weight of meltable
substances) having a melting point above 30°C
and a water solubility of less than 20 g/1 at
20°C,
c) from 0.1 to 15% by weight of one or more solids,
29
CA 02318000 2000-09-11
d) from 0 to 15% by weight of further active
substances and/or auxiliaries
into a cold gas stream.
The process of the invention, which is referred to for
short as prilling, comprises the production of granular
elements from meltable substances, the melt comprising
the ingredients a) to d) being sprayed in defined droplet
size at the top of a tower, solidifying in free fall, and
being obtained as prill granules at the base of the
tower.
As the cold gas stream it is possible in very general
terms to use all gases, the temperature of the gas being
below the melting temperature of the melt. In order to
avoid long falling sections, use is frequently made of
cooled gases, for example, supercooled air or even liquid
nitrogen, which is injected through a nozzle into the
spray towers.
The particle size of the resulting prills may be varied
by way of the choice of droplet size, with particle sizes
which are easy to realize technically lying within the
range from 0.5 to 2 mm, preferably around 1 mm.
An alternative process to prilling is pelletizing. A
further embodiment of the present invention therefore
envisages a process for preparing pelletized detergent
components, which comprises metering a melt comprising
a) from 10 to 89.9% by weight of surfactant(s),
b) from 10 to 89.9% by weight of meltable
substances) having a melting point above 30°C
and a water solubility of less than 20 g/1 at
20°C,
c) from 0.1 to 15% by weight of one or more solids,
CA 02318000 2000-09-11
d) from 0 to 15% by weight of further active
substances and/or auxiliaries
onto cooled pelletizing plates.
Pelletizing comprises the metering of the melt comprising
the respective ingredients onto a (cooled) belt or onto
rotating, inclined plates which have a temperature below
the melting temperature of the melt and are preferably
cooled to below room temperature. Here again, process
variants may be practiced in which the pelletizing plates
are supercooled. In this case, however, measures must be
taken to counter the condensation of atmospheric
moisture.
Pelletizing produces relatively large particles, which in
standard industrial processes have sizes of between 2 and
10 mm, preferably between 3 and 6 mm.
As an even more cost-effective variant for producing
particulate detergent components of the stated
composition from melts, the use of cooling rolls is
appropriate. A further subject of the present invention
is therefore a process for preparing particulate
detergent components, which comprises applying a melt
comprising
a) from 10 to 89.9% by weight of surfactant(s),
b) from 10 to 89.9% by weight of meltable
substances) having a melting point above 30°C
and a water solubility of less than 20 g/1 at
20°C,
c) from 0.1 to 15% by weight of one or more solids,
d) from 0 to 15% by weight of further active
substances and/or auxiliaries
by spraying or otherwise to a cooling roll, scraping off
the solidified melt, and comminuting the scrapings if
necessary.
31
CA 02318000 2000-09-11
The use of cooling rolls permits ready establishment of
the desired particle size range, which in this process of
the invention may also be below 1 mm, for example from
200 to 700 ~,m.
Of course, it is also possible in accordance with the
invention to compress the particulate compositions to a
tablet or a region thereof. This tablet may then be dosed
by the user, for example; alternatively, it may be added
to compositions which are in powder form. Another
possibility is to use the particulate compositions,
especially the prills, pellets or products from the
cooling roll, as a tabletable premix and to use this in
the preparation of multiphase tablets. Here, compressing
then gives, for example, multilayer tablets of which one
layer has the composition of a conventional detergent
tablet, the other layer the composition of the detergent
component of the invention, which displays its
advantageous nature in this commercial form as well.
Multiphase tablets may also be prepared by producing
tablets having cavities, for example, depressions or
continuous holes, and then filling these cavities with
other tablets. In the present case, it has been found
appropriate for the "base tablet", i.e., the tablet
having a cavity, to possess the composition of a
detergent tablet while the tablet present in the cavity
is a tablet which has been pressed from prills, pellets
or flakes. The adhesion of the two tablets to one another
may be achieved by adhesive bonding of the two tablets;
alternatively, it is possible to press the tablets onto
or into one another. Also possible is plugging, where
adhesion is brought about by the geometric design of
cavity and filling.
32
CA 02318000 2000-09-11
A preferred preparation process is, for example, the
preparation of the tablets by separate preparation
(compressing) of a base tablet a) and a core tablet b),
which is preferably pressed from prills of the detergent
components of the invention, followed by the joining and
the final compression of both parts.
The preparation of tablets from particulate detergent
components of the invention may take place in accordance
with common tableting procedures. These are described in
detail later on below.
The tablets may be produced in predetermined three-
dimensional forms and predetermined sizes. Suitable
three-dimensional forms are virtually any practicable
designs, i.e., for example, bar, rod or ingot form,
cubes, blocks and corresponding three-dimensional
elements having planar side faces, and in particular
cylindrical designs with a circular or oval cross
section. This latter design covers forms ranging from
tablets through to compact cylinders having a height-to-
diameter ratio of more than 1.
The produced tablet may take on any geometric form
whatsoever, with particular preference being given to
concave, convex, biconcave, biconvex, cubic, tetragonal,
orthorhombic, cylindrical, spherical, cylinder-
segmentlike, discoid, tetrahedral, dodecahedral,
octahedral, conical, pyramidal, ellipsoid, pentagonal-,
heptagonal- and octagonal-prismatic, and rhombohedral
forms. It is also possible to realize completely
irregular outlines such as arrow or animal forms, trees,
clouds, etc. If the produced tablet has corners and
edges, these are preferably rounded off. As an additional
visual differentiation, an embodiment having rounded
corners and beveled (chamfered) edges is preferred.
33
CA 02318000 2000-09-11
The detergent components of the invention may be given
directly to the consumer, who then doses them into the
detergent additionally as required. On the basis of this
additional dosing step, however, apart from the solid
supply form and the addition in the same dosing draw, the
advantages relative to liquid rinse aids would be
minimized. It is therefore preferred to admix the
detergent components of the invention to particulate
machine dishwashing compositions or to incorporate them
into tablets.
The present invention therefore additionally provides for
the use of particulate detergent components comprising
a) from 10 to 89.9% by weight of surfactant(s),
b) from 10 to 89.9% by weight of meltable
substances) having a melting point above 30°C
and a water solubility of less than 20 g/1 at
20°C,
c) from 0.1 to 15% by weight of one or more solids,
d) from 0 to 15% by weight of further active
substances and/or auxiliaries
in detergents for machine dishwashing.
The present invention further provides a particulate
machine dishwashing composition, comprising builders and
also, optionally, further detergent ingredients, said
composition comprising particulate detergent components
comprising, based on their weight,
a) from 10 to 89.9% by weight of surfactant(s),
b) from 10 to 89.9% by weight of meltable
substances) having a melting point above 30°C
and a water solubility of less than 20 g/1 at
20°C,
c) from 0.1 to 15% by weight of one or more solids,
34
CA 02318000 2000-09-11
d) from 0 to 15% by weight of further active
substances and/or auxiliaries.
The ingredients of the machine dishwashing compositions
are described hereinbelow. In some cases, they may also
be present as ingredient d) or support materials in the
detergent components of the invention.
The most important ingredients of machine dishwashing
compositions are builders. The machine dishwashing
detergents of the invention may comprise all of the
builders commonly used in detergents, i.e., in
particular, zeolites, silicates, carbonates, organic
cobuilders, and - where there are no ecological
prejudices against their use - the phosphates as well.
The builders mentioned below are all suitable as support
materials for the detergent components of the invention,
as set out earlier on above.
Suitable crystalline, layered sodium silicates possess
the general formula NaMSIXO2x+1'yF'~2~~ 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,
2.5 for example, in European Patent Application
EP-A-0 164 514. Preferred crystalline phyllosilicates of
the formula indicated are those in which M is sodium and
x adopts the value 2 or 3. In particular, both (3- and
8-sodium disilicates Na2Si205~yHz0 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:Si02 modulus of from 1:2 to 1:3.3,
preferably from 1:2 to 1:2.8, and in particular from 1:2
CA 02318000 2000-09-11
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 X-
radiation, having a width of several degree units of the
diffraction angle. However, good builder properties may
result, even particularly good builder properties, if the
silicate particles in electron diffraction experiments
yield vague or even sharp diffraction maxima. The
interpretation of this is that the products have
microcrystalline regions with a size of from 10 to
several hundred nm, values up to max. 50 nm and in
particular up to max. 20 nm being preferred. So-called X-
ray-amorphous silicates of this kind, which likewise
possess retarded dissolution relative to the conventional
waterglasses, are described, for example, in German
Patent Application DE-A-44 00 024. Particular preference
is given to compacted amorphous silicates, compounded
amorphous silicates, and overdried X-ray-amorphous
silicates.
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. Another 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
36
CA 02318000 2000-09-11
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.
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 detergents industry.
Alkali metal phosphates is the collective term for the
alkali metal (especially sodium and potassium) salts of
the various phosphoric acids, among which metaphosphoric
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
encrustations 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
37
CA 02318000 2000-09-11
lose the water of crystallization on heating and undergo
conversion at 200°C into the weakly acidic diphosphate
(disodium dihydrogen diphosphate, Na2H2P20~) and at a
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
biphosphate, PDP) , KHZP04, 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
Hz0), and 12 mol (density 1.52 g cm-3, melting point 35°
with loss of 5 H20) of water, becomes anhydrous at 100°,
and if heated more intensely undergoes transition to the
diphosphate Na4P20~. Disodium hydrogen phosphate is
prepared by neutralizing phosphoric acid with sodium
carbonate solution using phenolphthalein as indicator.
Dipotassium hydrogen phosphate (secondary or dibasic
potassium phosphate) , KZHP04, 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%
Pz05) have a density of 2.536 g cm-3. Trisodium phosphate
38
CA 02318000 2000-09-11
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 detergents
industry over the corresponding sodium compounds.
Tetrasodium diphosphate (sodium pyrophosphate), Na4P20~,
exists in anhydrous form (density 2.534 g cm-3, melting
point 988°, 880° also reported) and as the decahydrate
(density 1.815-1.836 g cm-3, melting point 94° with loss
of water). Both substances are colorless crystals which
dissolve in water with an alkaline reaction. Na4P20-, is
formed when disodium phosphate is heated to > 200° or by
reacting phosphoric acid with sodium carbonate in
stoichiometric ratio and dewatering the solution by
spraying. The decahydrate complexes heavy metal salts and
water hardeners and therefore reduces the hardness of the
water. Potassium diphosphate (potassium pyrophosphate),
K4P20~, exists in the form of the trihydrate and is a
colorless, hygroscopic powder of density 2.33 g cm-3 which
is soluble in water, the pH of the 1% strength solution
at 25° being 10.4.
Condensation of NaH2P04 or of KHZPO4 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
39
CA 02318000 2000-09-11
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 H20 and has the general formula Na0-
[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, about 20 g at 60°, around 32 g at 100°;
after heating the solution at 100°C 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, KSP301o (potassium
tripolyphosphate), is commercialized, for example, in the
form of a 50% strength by weight solution (> 23% Pz05, 25%
K20). The potassium polyphosphates find broad application
in the detergents 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 tripolyphosphate,
CA 02318000 2000-09-11
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 machine
dishwashing compositions 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
.L5 below.
Organic builder substances which may be used are, for
example, the polycarboxylic acids usable in the form of
their sodium salts, the term polycarboxylic acids meaning
those carboxylic acids which carry more than one acid
function. Examples of these are citric acid, adipic acid,
succinic acid, glutaric acid, malic acid, tartaric acid,
malefic acid, fumaric acid, sugar acids, amino carboxylic
acids, nitrilotriacetic acid (NTA), provided such use is
not objectionable on ecological grounds, and also
mixtures thereof. Preferred salts are the salts of the
polycarboxylic acids such as citric acid, adipic acid,
succinic acid, glutaric acid, tartaric acid, sugar acids,
and mixtures thereof.
The acids per se may also be used. In addition to their
builder effect, the acids typically also possess the
property of an acidifying component and thus also serve
to establish a lower and milder pH of detergents. In this
context, mention may be made in particular of citric
41
CA 02318000 2000-09-11
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.
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
42
CA 02318000 2000-09-11
are those of acrylic acid with malefic acid which contain
from 50 to 90% by weight of acrylic acid and from 50 to
10% by weight of 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 allylsulfonic acids, such as
allyloxybenzenesulfonic acid and methallylsulfonic acid,
for example, as monomers.
Particular preference is also given to biodegradable
polymers comprising more than two different monomer
units, examples being those comprising, as monomers,
salts of acrylic acid and of malefic acid, and also vinyl
alcohol or vinyl alcohol derivatives, or those
comprising, as monomers, salts of acrylic acid and of
2-alkylallylsulfonic acid, and also sugar derivatives.
Further preferred copolymers have as their monomers
preferably acrolein and acrylic asid/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 have not only cobuilder properties
bLlt also a bleach-stabilizing action.
43
CA 02318000 2000-09-11
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, 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. A
product oxidized at C6 of the saccharide ring may be
particularly advantageous.
44
CA 02318000 2000-09-11
Oxydisuccinates and other derivatives of disuccinates,
preferably ethylenediamine disuccinate, are further
suitable cobuilders. Ethylenediamine N,N'-disuccinate
(EDDS) is used preferably in the form of its sodium or
magnesium salts. Further preference in this context is
given to glycerol disuccinates and glycerol trisuccinates
as well. Suitable use amounts in formulations containing
zeolite and/or silicate are from 3 to 15% by weight.
Examples of further useful organic cobuilders are
acetylated hydroxy carboxylic acids and their salts,
which may also, if desired, 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.
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,
CA 02318000 2000-09-11
exper_ially 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.
Preferred particulate machine dishwashing compositions of
the invention comprise builders in amounts of from 20 to
80% by weight, preferably from 25 to 75% by weight, and
in particular from 30 to 70% by weight, based in each
case on the weight of the composition.
Important ingredients of detergents in addition to the
builders are, in particular, substances from the groups
of the surfactants, bleaches, bleach activators, enzymes,
polymers, fragrances, and dyes. Important representatives
from the aforementioned classes of substance are
described below, reference being made to the remarks
earlier on above in respect of the description of the
surfactants.
Preferred particulate machine dishwashing compositions
further comprise one or more substances from the groups
of the bleaches, bleach activators, bleaching catalysts,
surfactants, corrosion inhibitors, polymers, dyes,
fragrances, pH modifiers, complexing agents, and enzymes.
Among the compounds used as bleaches which yield H202 in
water, particular importance is possessed by sodium
percarbonate. Examples of further bleaches which may be
used are sodium perborate tetrahydrate and sodium
perborate monohydrate, peroxy pyrophosphates, citrate
perhydrates, and also Hz02-donating peracidic salts or
peracids, such as perbenzoates, peroxophthalates,
diperazelaic acid, phthaloimino peracid, or
diperdodecanedioic acid.
46
CA 02318000 2000-09-11
"Sodium percarbonate" is a term used unspecifically for
sodium carbonate peroxohydrates, which strictly speaking
are not "percarbonates" (i.e., salts of percarbonic acid)
but rather hydrogen peroxide adducts onto sodium
carbonate. The commercial product has the average
composition 2 Na2C03 ~ 3 H202 and is thus not a
peroxycarbonate. Sodium percarbonate forms a white,
water-soluble powder of density 2.14 g cm-3 which breaks
down readily into sodium carbonate and oxygen having a
bleaching or oxidizing action.
Sodium carbonate peroxohydrate was first obtained in 1899
by precipitation with ethanol from a solution of sodium
carbonate in hydrogen peroxide, but was mistakenly
regarded as a peroxycarbonate. Only in 1909 was the
compound recognized as the hydrogen peroxide addition
compound; nevertheless, the historical name "sodium
percarbonate" has persisted in the art.
Industrially, sodium percarbonate is produced
predominantly by precipitation from aqueous solution
(known as the wet process). In this process, aqueous
solutions of sodium carbonate and hydrogen peroxide are
combined and the sodium percarbonate is precipitated by
means of salting agents (predominantly sodium chloride),
crystallizing aids (for example polyphosphates,
polyacrylates), and stabilizers (for example, Mg2+ ions).
The precipitated salt, which still contains from 5 to 12%
by weight of the mother liquor, is subsequently
centrifuged and dried in fluidized-bed driers at 90°C.
The bulk density of the finished product may vary between
800 and 1200 g/1 according to the production process.
Generally, the percarbonate is stabilized by an
additional coating. Coating processes, and substances
used for the coating, are amply described in the patent
47
CA 02318000 2000-09-11
literature. Fundamentally, it is possible in accordance
with the invention to use all commercially customary
percarbonate types, as supplied, for example, by the
companies Solvay Interox, Degussa, Kemira or Akzo.
Detergents of the invention may also comprise bleaches
from the group of organic bleaches. Typical organic
bleaches are the diacyl peroxides, such as dibenzoyl
peroxide, for example. Further typical organic bleaches
are the peroxy acids, particular examples being the alkyl
peroxy acids and the aryl peroxy acids. Preferred
representatives are (a) peroxybenzoic acid and its ring-
substituted derivatives, such as alkylperoxybenzoic
acids, but peroxy-a-naphthoic acid and magnesium
monoperphthalate, (b) aliphatic or substituted aliphatic
peroxy acids, such as peroxylauric acid, peroxystearic
acid, s-phthalimidoperoxy caproic acid
[phthaloiminoperoxyhexanoic acid (PAP)], o-
carboxybenzamidoperoxycaproic acid, N-nonenyl-
amidoperadipic acid and N-nonenylamidopersuccinates, and
(c) aliphatic and araliphatic peroxy dicarboxylic acids,
such as 1,12-diperoxydecanedicarboxylic acid, 1,9-
diperoxyazelaic acid, diperoxysebacic acid,
diperoxybrassylic acid, the diperoxyphthalic acids, 2-
decyldiperoxybutane-1,4-dioic acid and N,N-
terephthaloyldi(6-aminopercaproic acid) may also be used.
Bleaches in the detergents of the invention for machine
dishwashing may also be substances which release chlorine
or bromine. Among the suitable chlorine- or bromine-
releasing materials, examples include heterocyclic N-
bromoamides and N-chloroamides, examples being
trichloroisocyanuric acid, tribromoisocyanuric acid,
dibromoisocyanuric acid and/or dichloroisocyanuric acid
(DICA) and/or salts thereof with cations such as
48
CA 02318000 2000-09-11
potassium and sodium. Hydantoin compounds, such as 1,3-
dichloro-5,5-dimethylhydantoin, are likewise suitable.
In order to achieve a "post-bleaching" effect, the
abovementioned bleaches may also be introduced into the
machine dishwashing compositions of the invention in part
by way of the detergent components of the invention,
where they represent the ingredient d).
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
tetraacetylethylenediamine TAED, tetraacetylmethylene-
diamine TAMD, and tetraacetylhexylenediamine TAHD, and
also pentaacetylglucose PAG, 1,5-diacetyl-2,2-
dioxohexahydro-1,3,5-triazine DADHT, and isatoic
anhydride ISA.
Bleach activators which may be used are compounds which
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-dioxohexahydro-
1,3,5-triazine (DADHT), acylated glycolurils, especially
tetraacetylglycoluril (TAGU), N-acylimides, especially N-
nonanoylsuccinimide (NOSI), acylated phenolsulfonates,
especially n-nonanoyl- or isononanoyloxybenzenesulfonate
(n- or iso-NOBS), carboxylic anhydrides, especially
49
- CA 02318000 2000-09-11
phthalic anhydride, acylated polyhydric alcohols,
especially triacetin, ethylene glycol diacetate, 2,5-
diacetoxy-2,5-dihydrofuran, 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), pentaacetylfructose, tetraacetylxylose and
octaacetyllactose, and acetylated, optionally N-alkylated
glucamine and gluconolactone, and/or N-acylated lactams,
for example, N-benzoylcaprolactam. Hydrophilically
substituted acylacetals and acyllactams are likewise used
with preference. Combinations of conventional bleach
activators may also be used.
In addition to the conventional bleach activators, or
instead of them, it is also possible to incorporate what
are known as bleaching catalysts into the machine
dishwashing detergents. 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
CA 02318000 2000-09-11
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 acetate complexes, cobalt carbonyl complexes, the
chlorides of cobalt or manganese, and manganese sulfate,
are used in customary amounts, preferably in an amount of
up to 5% by weight, in particular from 0.0025% by weight
to 1% by weight, and with particular preference from
0.01% by weight to 0.25% by weight, based in each case on
the overall composition. In specific cases, however, it
is also possible to use a greater amount of bleach
activator.
Suitable enzymes in the detergents of the invention
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 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
51
CA 02318000 2000-09-11
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.
Dyes and fragrances may be added to the machine
dishwashing compositions of the invention in order to
enhance the esthetic appeal of the products which are
formed and to provide the consumer with not only the
performance but also a visually and sensorially "typical
and unmistakable" 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-butylcyclohexyl acetate, linalyl acetate, dimethyl-
benzylcarbinyl acetate, phenylethyl acetate, linalyl
benzoate, benzyl formate, ethyl methylphenylglycinate,
allyl cyclo-hexylpropionate, styrallyl propionate, and
benzyl salicylate. The ethers include, for example,
benzyl ethyl ether; the aldehydes include, for example,
the linear alkanals having 8-18 carbon atoms, citral,
citronellal, citronellyloxyacetaldehyde, cyclamen
52
CA 02318000 2000-09-11
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, neroli oil, orange peel oil, and sandalwood oil.
The fragrances may be incorporated directly into the
detergent of the invention; alternatively, it may be
advantageous to apply the fragrances to carriers.
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.
Incorporating the fragrances as ingredient d) into the
detergent components of the invention is also possible,
and results in a fragrance sensation when the machine is
opened.
In order to enhance the esthetic appeal of the
compositions of the invention, they (or parts thereof)
may be colored 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
53
CA 02318000 2000-09-11
compositions or to light and possess no pronounced
affinity for the substrates to be treated with the
compositions, such as glass, ceramic, or plasticware, so
as not to stain them.
The detergents of the invention may include 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
chlorine, which may significantly reduce corrosion of the
silver surface. In chlorine-free cleaners, use is made in
particular of oxygen-containing and nitrogen-containing
organic redox-active compounds, such as divalent and
trivalent phenols, e.g. hydroquinone, pyrocatechol,
hydroxyhydroquinone, gallic acid, phloroglucinol,
pyrogallol, and derivatives of these classes of compound.
Inorganic compounds in the form of salts and complexes,
such as salts of the metals Mn, Ti, Zr, Hf, V, Co and Ce,
also find frequent application. Preference is given in
this context to the transition metal salts selected from
the group consisting of manganese and/or cobalt salts
and/or complexes, with particular preference cobalt
ammine complexes, cobalt acetato complexes, cobalt
carbonyl complexes, the chlorides of cobalt or of
manganese and manganese sulfate. Similarly, zinc
compounds may be used to prevent corrosion on the ware.
54
CA 02318000 2000-09-11
The particulate machine dishwashing compositions of the
invention may comprise the detergent components of the
invention in varying amounts, the amount being higher or
lower depending on the composition of the detergent
components and on the desired success. Preferred
particulate machine dishwashing compositions comprise the
particulate detergent component in amounts of from 0.5 to
30% by weight, preferably from 1 to 25% by weight, and in
particular from 3 to 15% by weight, based in each case on
overall composition.
In terms of their composition, the detergent components
of the invention may be designed so that they dissolve to
a minor extent, if at all, in the main wash cycle (and
also in optional prewash. cycles). This ensures that the
surfactants are not released until the rinse cycle, where
they develop their action. In addition to this chemical
formulation, a physical formulation may be necessary
depending on the type of dishwasher, so that the rinse
aid particles are not pumped off in the machine when the
water is changed and hence are no longer available for
the rinse cycle. Standard domestic dishwashers, upstream
of the detergent-liquor pump, which pumps the water or
cleaning solution from the machine after the individual
cleaning cycles, comprise a sieve insert, intended to
prevent clogging of the pump by food residues. If the
user cleans heavily soiled kitchen- and tableware, then
this sieve insert requires regular cleaning, which is a
simple operation owing to the ease of access and
removability. The detergent components of the invention,
then, are preferably designed in terms of their size and
shape such that they do not pass through the sieve insert
of the dishwasher even after the cleaning cycle, i.e.,
after exposure to agitation in the machine and to the
detergent solution. This ensures that detergent
components are present in the dishwasher in the rinse
CA 02318000 2000-09-11
cycle, these detergent components releasing the active
substance (s) under the action of the warmer water and so
bringing the desired rinse effect. Particulate machine
dishwashing compositions that are preferred in the
context of the present invention are those wherein the
particulate detergent component has particle sizes of
between 1 and 40 mm, preferably between 1.5 and 30 mm,
and in particular between 2 and 20 mm.
In the dishwashing compositions of the invention, the
detergent components, having the sizes stated above, may
project from the matrix of the other particulate
ingredients; alternatively, the other particles may
likewise have sizes within the stated range, so that,
overall, a detergent is formulated that comprises large
detergent particles and detergent-component particles.
Especially if the detergent components of the invention
are colored, i.e., have red, blue, green, or yellow
color, for example, it is advantageous for the appearance
of the product, i.e., of the overall detergent, if the
detergent components are visibly larger than the matrix
comprising the particles of the other ingredients of the
detergent. Here, preference is given to inventive
particulate machine dishwashing compositions which
(without taking into account the particulate detergent
component) have particle sizes of between 100 and
3000 ~,m, preferably between 300 and 2500 ~,m, and in
particular between 400 and 2000 ~.m.
If the detergents of the invention are formulated as a
powder mixture, then - especially if there are large
differences between the size of detergent component and
detergent matrix - on the one hand partial separation may
occur when the pack is shaken, and on the other hand
dosing may be different in two successive washing
operations, since the user does not always automatically
56
CA 02318000 2000-09-11
dose equal quantities of the detergent and detergent
component. If it is desired technically to use an
identical quantity for each washing operation, this can
be realized by the packaging - familiar to the skilled
worker - of the compositions of the invention in water-
soluble film bags. The present invention also provides a
particulate machine dishwashing composition wherein one
dose unit is welded in a water-soluble film bag.
By this means, the user need only insert a bag,
containing for example a detergent powder and a plurality
of visually distinctive detergent-component particles,
into the dosing drawer of his or her dishwasher. This
embodiment of the present invention is therefore a
visually attractive alternative to conventional detergent
tablets.
Since the user does not use only particulate detergents
for machine dishwashing, but would also like to have
recourse to tablets, these are further provided by the
present invention. For this purpose, the melt comprising
the ingredients a) to d) may be formulated as a phase of
a tablet, said phase possessing, for example, the form of
layer, corelike insert, etc.
The present invention thus further provides a multiphase
detergent tablet for machine dishwashing, comprising
builders and also, optionally, further detergent
ingredients, wherein at least one phase comprises
a) from 10 to 89.9% by weight of surfactant(s),
b) from 10 to 89.9% by weight of meltable
substances) having a melting point above 30°C
and a water solubility of less than 20 g/1 at
20°C,
c) from 0.1 to 15% by weight of one or more solids,
57
CA 02318000 2000-09-11
d) from 0 to 15% by weight of further active
substances and/or auxiliaries.
In the context of the present invention, the individual
phases of the tablet may have different three-dimensional
forms. The simplest embodiment is that of two-layer or
multilayer tablets, each layer of the tablet constituting
one phase. In accordance with the invention, however, it
is also possible to prepare multiphase tablets in which
individual phases have the form of inclusions into
(an)other phase(s). In addition to so-called "ring-core"
tablets, possible examples include laminated tablets or
combinations of the stated embodiments. Examples of
multiphase tablets can be found in the figures of
EP-A-055 100 (Jeyes), which describes toilet cleaning
blocks. The most widespread three-dimensional form in the
art at present for multiphase tablets is the two-layer or
multilayer tablet. In the context of the present
invention, therefore, it is preferred for the phases of
the tablet to have the form of layers and for the tablet
to have 2, 3 or 4 phases.
The tablets of the invention may take on any geometric
form whatsoever, with particular preference being given
to concave, convex, biconcave, biconvex, cubic,
tetragonal, orthorhombic, cylindrical, spherical,
cylinder-segmentlike, discoid, tetrahedral, dodecahedral,
octahedral, conical, pyramidal, ellipsoid, pentagonal-,
heptagonal- and octagonal-prismatic, and rhombohedral
forms. It is also possible to realize completely
irregular outlines such as arrow or animal forms, trees,
clouds, etc. If the tablets of the invention have corners
and edges, these are preferably rounded off. As an
additional visual differentiation, an embodiment having
rounded corners and beveled (chamfered) edges is
preferred.
58
_ CA 02318000 2000-09-11
Instead of the layer structure, it is also possible to
prepare tablets which comprise the detergent component of
the invention in the form of other phases. Here, it has
been found suitable to prepare base tablets which have
one or more cavities, and to insert the melt comprising
ingredients a) to d) of the detergent component of the
invention into the cavity and allow it to solidify
therein. This preparation process produces preferred
multiphase detergent tablets comprising a base tablet,
which has a cavity, and a part present at least partially
in the cavity.
The cavity in the compressed part of such tablets of the
invention may have any form whatsoever. It may go right
through the tablet, i.e., have an opening on different
sides, for example, at the top and bottom side, of the
tablet; alternatively, it may be a cavity which does not
go through the entire tablet, and whose opening is
visible only on one tablet side. The form of the cavity
may also be chosen freely within wide limits. For reasons
of process economy, continuous holes whose openings are
located on opposite faces of the tablets, and depressions
having an opening at one tablet side, have become
established. In preferred detergent tablets, the cavity
has the form of a continuous hole whose openings are
located on two opposite tablet surfaces. The form of a
continuous hole of this kind may be chosen freely,
preference being given to tablets wherein the continuous
hole has circular, ellipsoid, triangular, rectangular,
square, pentagonal, hexagonal, heptagonal or octagonal
horizontal sections. It is also possible to realize
completely irregular hole shapes, such as arrow or animal
forms, trees, clouds, etc. As with the tablets,
preference is given, in the case of angular holes, to
those having rounded corners and edges or having rounded
corners and chamfered edges.
59
CA 02318000 2000-09-11
The abovementioned geometric embodiments may be combined
with one another as desired. For instance, it is just as
possible to prepare tablets having a rectangular or
square outline and circular holes as it is to prepare
circular tablets having octagonal holes, there being no
limits on the diversity of possible combinations. For
reasons of process economy and the esthetic perception of
the user, particular preference is given to tablets with
a hole, where the tablet outline and the hole cross
section have the same geometric form, examples being
tablets having a square outline and a square hole made
centrally therein. Particular preference is given in this
context to annular tablets, i.e., circular tablets with a
circular hole.
If the aforementioned principle of the hole open at twc
opposite tablet sides is reduced to an opening,
depression tablets are obtained. Detergent tablets of the
invention wherein the cavity has the form of a depression
are likewise preferred. With this embodiment, as with the
"hole tablets", the tablets of the invention may take on
any geometric form whatsoever, with particular preference
being given to concave, convex, biconcave, biconvex,
cubic, tetragonal, orthorhombic, cylindrical, spherical,
cylinder-segmentlike, discoid, tetrahedral, dodecahedral,
octahedral, conical, pyramidal, ellipsoid, pentagonal-,
heptagonal- and octagonal-prismatic, and rhombohedral
forms. It is also possible to realize completely
irregular outlines such as arrow or animal forms, trees,
clouds, etc. If the tablet has corners and edges, these
are preferably rounded off. As additional visual
differentiation, an embodiment having rounded corners and
beveled (chamfered) edges is preferred.
60
CA 02318000 2000-09-11
The form of the depression may also be chosen freely,
preference being given to tablets in which at least one
depression may take on a concave, convex, cubic,
tetragonal, orthorhombic, cylindrical, spherical,
cylinder-segmentlike, discoid, tetrahedral, dodecahedral,
octahedral, conical, pyramidal, ellipsoid, pentagonal-,
heptagonal- and octagonal-prismatic, or rhombohedral
form. It is also possible to realize completely irregular
depression forms, such as arrow or animal forms, trees,
clouds, etc. As with the tablets, depressions having
rounded corners and edges or having rounded corners and
chamfered edges are preferred.
In the case set out above, the part present at least
partially in the cavity consists solely of ingredients a)
to d) of the detergent components. It is, however, also
possible to introduce support material-based detergent
components into the cavity (cavities). For reasons of
process economy, however, preference is given to
multiphase detergent tablets wherein the part present in
the cavity comprises
a) from 10 to 89.9% by weight of surfactant(s),
b) from 10 to 89.9% by weight of meltable
substances) having a melting point above 30°C
and a water solubility of less than 20 g/1 at
20°C,
c) from 0.1 to 15% by weight of one or more solids,
d) from 0 to 15% by weight of further active
substances and/or auxiliaries.
The size of the depression or continuous hole in
comparison to the total tablet is guided by the desired
end use of the tablets. Depending on with how much
further active substance the remaining void volume is to
be filled, and on whether a smaller or larger amount of
detergent component is to be present, the size of the
61
CA 02318000 2000-09-11
cavity may vary. Irrespective of the end use, in
preferred detergent tablets the volume ratio of
compressed part ("base tablet") to detergent component is
from 2:1 to 100:1, preferably from 3:1 to 80:1, with
particular preference from 4:1 to 50:1, and in particular
from 5:1 to 30:1.
Besides the stated volume ratio, it is also possible tc
state a mass ratio of the two parts, the two values
correlating to one another by way of the densities of the
base tablet and, respectively, of the detergent
component. Irrespective of the density of the individual
parts, preference is given to detergent tablets of the
invention wherein the weight ratio of base tablet to
detergent component is from 1:1 to 100:1, preferably from
2:1 to 80:1, with particular preference from 3:1 to 50:1,
and in particular from 4:1 to 30:1.
Analogous details may also be given for the surfaces
visible in each case of the base tablet and,
respectively, of the detergent component. Here,
preference is given to detergent tablets wherein the
outwardly visible surface area of the detergent component
accounts for from 1 to 25%, preferably from 2 to 20%,
with particular preference from 3 to 15%, and in
particular from 4 to 10%, of the total surface area of
the tablet.
The detergent component and the base tablet are
preferably colored so as to be visually distinguishable.
In addition to visual differentiation, performance
advantages may be obtained by virtue of different
solubilities of the different regions of the tablet.
Detergent tablets in which the detergent component
dissolves more rapidly than the base tablet are preferred
in accordance with the invention. By incorporating
62
- CA 02318000 2000-09-11
certain constituents, on the one hand, it is possible to
accelerate specifically the solubility of the detergent
component; secondly, the release of certain ingredients
from the detergent component may lead to advantages in
the washing or cleaning process.
Preference is also given, of course, to detergent tablets
of the invention wherein the detergent component
dissolves later in the wash program than the base tablet.
Performance advantages from this retarded release may be
achieved, for example, by using a slower-dissolving
detergent component to release active substances) only
in later cycles. Thus in the case of machine dishwashing,
for example, it can be ensured by means of slower-
dissolving detergent components that further active
substances) is(are) available in the rinse cycle. By
means of additional substances such as nonionic
surfactants, acidifiers, soil release polymers, etc., it
is possible in this way to enhance the rinse results. The
incorporation of perfume is also readily possible; by
means of its retarded release it is possible in the case
of dishwashers to eliminate the "alkali odor" when the
machine is opened, which is a frequent occurrence. In
relation to the detergent components of the invention,
the acidifier, soil release polymer, etc. ingredients are
in this case ingredients d).
In preferred embodiments of the present invention the
base tablet possesses a high specific weight. The
invention prefers detergent tablets wherein the base
tablet has a density of more than 1000 g dm-3, preferably
more than 1025 g dm-3, with particular preference more
than 1050 g dm-3, and in particular more than 1100 g dm-3.
In order to facilitate the disintegration of highly
compacted tablets, it is possible to incorporate
63
- CA 02318000 2000-09-11
disintegration aids, known as tablet disintegrants, intc
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 on the one hand an increase in the intrinsic volume
(swelling) and on the other hand, by way of the release
of gases, 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 aids
20. 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 detergent tablets contain from 0.5 to 10% by
weight, preferably from 3 to 7% by weight, and in
particular from 4 to 6% by weight, of one or more
disintegration aids, based in each case on the tablet
weight. If only the base tablet comprises disintegration
aids, then these figures are based only on the weight of
the base tablet. If disintegration aids are incorporated
into the detergent components of the invention, they
count as ingredient d).
Preferred disintegrants used in the context of the
present invention are cellulose-based disintegrants and
64
- CA 02318000 2000-09-11
so preferred detergent tablets comprise a cellulose-based
disintegrant of this kind in amounts from 0.5 to 10°s by
weight, preferably from 3 to 7°s 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 units and, accordingly, have average molecular
masses of from 50,000 to 500,000. Cellulose-based
disintegrants which can be used also include, in the
context of the present invention, cellulose derivatives
obtainable by polymer-analogous reactions from cellulose.
Such chemically modified celluloses include, for example,
products of esterifications and etherifications in which
hydroxy hydrogen atoms have been substituted. However,
celluloses in which the hydroxy groups have been replaced
by functional groups not attached by an oxygen atom may
also be used as cellulose derivatives. The group of the
cellulose derivatives embraces, for example, alkali metal
celluloses, carboxymethyl-cellulose (CMC), cellulose
esters and cellulose ethers and aminocelluloses. Said
cellulose derivatives are preferably not used alone as
cellulose-based disintegrants but instead are used in a
mixture with cellulose. The cellulose derivative content
of these mixtures is preferably less than 50°s 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. Detergent tablets comprising
. CA 02318000 2000-09-11
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 cellulose-based disintegration aids,
and those described in more detail in the cited
documents, are preferred for use as disintegration aids
in the context of the present invention and are available
commercially, for example, under the designation Arbocel~
TF-30-HG from the company Rettenmaier.
As a further cellulose-based disintegrant or as a
constituent of this component it is possible to use
microcrystalline cellulose. This microcrystalline
cellulose is obtained by partial hydrolysis of celluloses
under conditions which attack only the amorphous regions
(approximately 30% of the total cellulose mass) of the
celluloses and break them up 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.
Detergent tablets which are preferred in the context of
the present invention further comprise a disintegration
aid, preferably a cellulose-based disintegration aid,
preferably in granular, cogranulated or compacted form,
66
CA 02318000 2000-09-11
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 tablet weight.
The detergent tablets of the invention may further
comprise, both in the base tablet and in the detergent
component, a gas-evolving effervescent system. Said gas-
evolving effervescent system may consist of a single
substance which on contact with water releases a gas.
Among these compounds mention may be made, in particular,
of magnesium peroxide, which on contact with water
releases oxygen. Normally, however, the gas-releasing
effervescent system consists in its turn of at least two
constituents which react with one another and, in so
doing, form gas. Although a multitude of systems which
release, for example, nitrogen, oxygen or hydrogen are
conceivable and practicable here, the effervescent system
used in the detergent tablets of the invention will be
selectable on the basis of both economic and
environmental considerations. Preferred effervescent
systems consist of alkali metal carbonate and/or alkali
metal hydrogen carbonate and of an acidifier apt to
release carbon dioxide from the alkali metal salts in
aqueous solution.
Among the alkali metal carbonates and/or alkali metal
hydrogen carbonates, the sodium and potassium salts are
much preferred over the other salts on grounds of cost.
It is of course not mandatory to use the pure alkali
metal carbonates or alkali metal hydrogen carbonates in
question; rather, mixtures of different carbonates and
hydrogen carbonates may be preferred from the standpoint
of wash technology.
In preferred detergent tablets, the effervescent system
used comprises from 2 to 20% by weight, preferably from 3
67
- CA 02318000 2000-09-11
to 15% by weight, and in particular from 5 to 10% by
weight, of an alkali metal carbonate or alkali metal
hydrogen carbonate, and from 1 to 15, preferably from 2
to 12, and in particular from 3 to 10% by weight of an
acidifier, based in each case on the total tablet.
As examples of acidifiers which release carbon dioxide
from the alkali metal salts in aqueous solution it is
possible to use boric acid and also alkali metal hydrogen
sulfates, alkali metal dihydrogen phosphates, and other
inorganic salts. Preference is given, however, to the use
of organic acidifiers, with citric acid being a
particularly preferred acidifier. However, it is also
possible, in particular, to use the other solid mono-,
oligo- and polycarboxylic acids. Preferred among this
group, in turn, are tartaric acid, succinic acid, malonic
acid, adipic acid, malefic acid, fumaric acid, oxalic
acid, and polyacrylic acid. Organic sulfonic acids such
as amidosulfonic acid may likewise be used. A
commercially available acidifier which is likewise
preferred for use in the context of the present invention
is Sokalan°' DCS (trademark of BASF), a mixture of
succinic acid (max. 31% by weight), glutaric acid (max.
50% by weight), and adipic acid (max. 33% by weight).
In the context of the present invention, preference is
given to detergent tablets where the acidifier used in
the effervescent system comprises a substance from the
group of the organic di-, tri- and oligocarboxylic acids,
or mixtures thereof.
Following production, the particulate detergents and/or
detergent tablets of the invention, and the novel
detergent components per se, may be packed, the use of
certain packaging systems having proven particularly
useful. The present invention additionally provides a
68
CA 02318000 2000-09-11
combination comprising (a) particulate detergents)
and/or (a) detergent tablets) of the invention and a
packaging system containing said detergent and/or said
detergent tablet(s), said packaging system having a
moisture vapor transmission rate of from 0.1 g/m2/day to
less than 20 g/mz/day if said packaging system is stored
at 23°C and a relative equilibrium humidity of 850.
The packaging system of the combination of detergent
component and/or detergent and/or detergent 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 ~ 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 ("4~later
vapor permeability of sheet materials at high temperature
and humidity"). The measurement 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:
MVTR = 24 ~ 10,000 , x
A -[g/mz /24 h)
Y
69
CA 02318000 2000-09-11
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 reached with just 10 g
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 (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 humidities are formed in
closed systems at a given temperature over saturated
solutions of certain salts, these humidities deriving
from the phase equilibrium between water partial
pressure, saturated solution, and sediment.
- CA 02318000 2000-09-11
The combinations of the invention may of course in turn
be packaged in secondary packaging, examples being
cardboard packaging 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/m2/day.
Depending on the embodiment of the invention, the
packaging system of the combination of the invention
contains a defined amount of novel detergent component, a
defined amount of a particulate detergent composition, or
one or more detergent tablets. In accordance with the
invention it is preferred either to design a tablet such
that it comprises one application unit of the detergent,
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 detergent, therefore, it is possible in accordance
with the invention to produce and package individually
one detergent tablet weighing 80 g, but in accordance
with the invention it is also possible to package two
detergent 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 detergent
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.
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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 detergent 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 detergent tablets individually, or
sorted into groups of two or more, into bags or pouches .
For individual application units of the detergent tablets
which 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 - again,
preferably sorted - be packaged into outer packaging,
which underscores the compact commercial 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 (heat
sealing), 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
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CA 02318000 2000-09-11
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 ~,m,
preferably from 20 to 100 ~,m, and in particular from 25
to 50 ~,m.
Although it is possible in addition to the abovementioned
films and papers also to use wax-coated papers in the
form of cardboard packaging as a packaging system for the
detergent 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. In
the context of the present invention, the term "packaging
system" always relates to the primary packaging of the
detergent component, composition or tablets, i.e., to the
packaging whose inner face is in direct contact with the
detergent component, composition or 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 detergent
components, detergent compositions, or detergent tablets
of the combination in accordance with the invention
comprise further ingredients of detergents, in varying
amounts, depending on their intended use. Independently
of the intended use of the compositions or tablets, it is
preferred in accordance with the invention for the
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detergent compositions) or tablets) to have a relative
equilibrium humidity of less than 30% at 35°C.
The relative equilibrium humidity of the detergent
compositions or 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 detergent 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, England). The water vapor pressure is
then measured every 10 minutes until two successive
values show no deviation (equilibrium humidity). The
abovementioned hygrometer permits direct display of the
recorded values in % relative humidity.
Likewise preferred are embodiments of the combination in
accordance with the invention wherein the packaging
system is of resealable configuration. Combinations
wherein the packaging system has a microperforation may
also be realized with preference in accordance with the
invention.
As mentioned earlier on above, detergent components,
detergent compositions or detergent tablets for machine
dishwashing may be prepared by the processes of the
invention. Accordingly, the present invention
additionally provides a method of cleaning kitchen- and
tableware in a dishwasher, which comprises placing one or
more particulate detergents and/or one or more detergent
tablets of the invention in the dispensing compartment of
the dishwasher and running a wash program in the course
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CA 02318000 2000-09-11
of which the dispensing compartment opens and the
detergents) and/or tablets) is or are dissolved.
With the cleaning method of the invention as well it is
possible to forego the dispensing compartment and to
place the detergent components and/or detergent
compositions or the tablets) of the invention, for
example, in 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 kitchen- and
tableware in a dishwasher, which comprises placing one or
more particulate detergents of the invention and/or 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 detergents) and/or the tablets) is or are
dissolved.
Examples:
Melt dispersions and melt emulsions of the following
composition [% by weight] were prepared:
V1 V2 El E2 E3
Paraffin 57-60C 50.0 45.0 50.0 45.0 45.0
Nonionic surfactant* 45.0 45.0 42.5 45.0 49.7
Potassium acetate** - - 2.5 - -
Mod. bentonite*** - - - - 0.3
FAS dust **** 5.0 5.0
Auxiliary***** 5.0 5.0 5.0 5.0 5.0
L~~~y-~dYpeu polyoxyalkylated alcohol
softening point 25-45°C
** 100% < 100 ~.m
CA 02318000 2000-09-11
*** Thixogel~ MP250, Sudchemie
**** E2: Clz-la fatty alcohol sulfate, 90% < 200 ~m
V2: Clz-is fatty alcohol sulfate, 90% > 200 ~,m,
average particle size 300 ~,m
***** Polyglycerol poly-12-hydroxystearate
This was done by heating the nonionic surfactant to 85°C,
adding the paraffin with stirring, and finally adding the
remaining ingredients. The stability of the
suspension/emulsion was evaluated at 85°C by switching
off the stirrer and examining it visually.
The evaluation was based on the following scheme:
++ visible separation after > 60 s
+ visible separation after > 30 s
- visible separation after < 30 s
-- visible separation after switching off the
stirrer < 10 s
The following table shows the resu7rs
V1 v2 E1 E1 E3
-_ -- ++
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