Note: Descriptions are shown in the official language in which they were submitted.
CA 02272642 1999-OS-20
WO 98/24874 ~ PCT/US97/21042
COATED DETERGENT TABLET
The present invention relates to coated detergent tablets, especially those
adapted for
use in washing machines, and to processes for making the coated detergent
tablets.
Although cleaning compositions in tablet form have often been proposed, these
have
not (with the exception of soap bars for personal washing) gained any
substantial
success, despite the several advantages of products in a unit dispensing form.
One
of the reasons for this may be that detergent tablets require a relatively
complex
manufacturing process. In particular, it is often desirable to provide the
tablet with a
coating and this adds to the difficulties of manufacture.
While tablets without a coating are entirely effective in use, they usually
lack the
necessary surface hardness to withstand the abrasion that is a part of normal
manufacture, packaging and handling. The result is that uncoated tablets
suffer from
abrasion during these processes, resulting in chipped tablets and loss of
active
material.
Finally, coating of tablets is often desired for aesthetic reasons, to improve
the outer
appearance of the tablet or to achieve some particular aesthetic effect.
Numerous methods of tablet coating have been proposed, and many of these have
been suggested for detergent tablets. However, all of these methods have
certain
disadvantages, as will be explained below.
GB-A-0 989 683, published on 22nd April 1965, discloses a process for
preparing a
particulate detergent from surfactants and inorganic salts; spraying on water-
soluble
silicate: and pressing the detergent particles into a solid form-retaining
tablet. Finally
a readily water-soluble organic film-forming polymer (for example, polyvinyl
alcohol) provides a coating to make the detergent tablet resistant to abrasion
and
accidental breakage.
EP-A-0 002 293, published on 13th June 1979, discloses a tablet coating
comprising
hydrated salt such as acetate, metaborate, orthophosphate, tartrate, and
sulphate.
EP-A-0 716 144, published on 12th June 1996, also discloses laundry detergent
tablets with water-soluble coatings which may be organic polymers including
acrylic/maleic co-polymer, polyethylene glycol, PVPVA, and sugar.
CA 02272642 2002-02-27
2
WO 95/18215, ;?ublished on 6th July 199. provides water-insoluble coatings for
solid cast tablets. The tablets are provided with hydrophobic coatings
including wax,
fatty acid, fatty acid amides. and polyethylene glycol.
None of the prior art discloses the use of dicarboxylic acid coating materials
for
tablets that have a soft core prepared by compression of particulate
materials.
The present invention provides a means by which tablets with a core which is
formed by compressing a particulate material, the particulate material
comprising
surfactant and detergent builder. can be provided with a hard, thin, coating
so that
they can be stored, shipped and handled, bnt the coating is broken when the
tablet is
in the washing machine exposing the soft core which breaks up easily and
rapidly,
releasing the active ingredients into the wash solution.
The object of the present invention is to provide a tablet which completely
disintegrates and disperses in alkaline or surfactant-rich solutions such as
the wash
liquor.
Summary of the Invention
T'he object of the invention is acheived by providing a coating comprising a
dicarboxylic acid, preferably wherein the length of the carbon chain of the
dicarboxylic acid 15 from C'z to C,3.
In one embodiment of the invention there is provided a detergent tablet
comprising a
core and a coating, the core being formed by compressing a particulate
material, the
particulate material comprising surfactant and dcaergent builder,
characterised in that
the coating has a melting point of from 40"C to 200°C and comprises
dicarboxylic
acid, said tablet further comprising: (t) a water-swellable disintegrant
present in said
coating; or (ii) an effervescent present in said core; or (iii) a combination
of (t) and
(ii).
1n a further aspect of the invention there is provided a process for making a
coated
detergent tablet comprising the steps of: (a) forming a core by compressing a
particulate material, the particulate material comprising surfactant and
detergent
builder; (b) applying a coating material to the core, the coating material
being in the
form of a melt and having a melting point of from 40°C to 200°C;
(c) allowing the
molten coating material to solidify; characterised in that the coating
material
comprises dicarboxylic acid, wherein said tablet further comprises: (t) a
water-
swellable disintegrant present in said coating; or (ii) an effervescent
present in said
core; or (iii) a combination of (t) or (ii).
CA 02272642 2002-02-27
3
In an alternative to this embodiment of the invention there is provided a
process for
making a coated detergent tablet comprising the steps of: (a) forming a core
by
compressing a particulate material, the particulate material comprising
surfactant
and detergent builder; (b) applying a coating material to the core, the
coating
material having a melting point of from 40°C' to 200°C and being
dissolved in a
solvent or water; (c) allowing the solvent or water to evaporate;
characterised in that
the coating material comprises dicarboxylic; acid, wherein the tablet further
comprises: (l) a water-swellable clisintegrant present in said coating; or
(ii) an
effervescent present in said core; or (iii) a combination of (l) or (ii).
Detailed Description of the Invention
Tablets to be coated in the present invention can be prepared simply by mixing
the
solid ingredients together and compressing the mixture in a conventional
tablet press
as used, for example, in the pharmaceutical industry. Any liquid ingredients,
for
example the surfactant or suds suppressor, can be incorporated in a
conventional
manner into the solid particulate ingredients. Preferably the principal
ingredients,
are used in particulate form.
In particular for laundry tablets. the ingredients such as builder and
surfactant can be
spray-dried in a conventional manner acrd then compacted at a suitable
pressure.
The detergent tablets can be made in any size or shape and carr, if desired.
be surface
treated before coating, according to the present invention. In the core of the
tablet is
included a surfactant and a builder which normally provides a substantial part
of the
cleaning power of the tablet. The term "builder'' is intended to mean all
materials
which tend to remove calcium ion from solution, either by ion exchange,
complexation, sequestration or precipitation.
The particulate material used for making the tablet of this invention can be
made by
any particulation or granulation process. An example of such a process is
spray
drying (in a co-current or counter current spray drying tower) which typically
gives
low bulk densities 600g/1 or lower. Particulate materials of higher density
can be
prepared by granulation and densification in a high shear batch
mixer/granulator or
by a continuous granulation and densification process (e.g. using Lodige~ CB
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WO 98/24874 PCT/US97/21042
4
and/or Lodige~ KM mixers). Other suitable processes include fluid bed
processes,
compaction processes (e.g. roll compaction), extrusion. as well as any
particulate
material made by any chemical process like flocculation, crystallisation
centering,
etc. Individual particles can also be any other particle, granule, sphere or
grain.
The particulate materials may be mixed together by any conventional means.
Batch
is suitable in, for example, a concrete mixer, Nauta mixer, ribbon mixer or
any other.
Alternatively the mixing process may be carried out continuously by metering
each
component by weight on to a moving belt, and blending them in one or more
drums) or mixer(s). A liquid spray-on to the mix of particulate materials
(e.g. non-
ionic surfactants) may be carried out. Other liquid ingredients may also be
sprayed
on to the mix of particulate materials either separately or premixed. For
example
perfume and slurries of optical brighteners may be sprayed. A finely divided
flow
aid (dusting agent such as zeolites, carbonates, silicas) can be added to the
particulate materials after spraying the non-ionic, preferably towards the end
of the
process, to make the mix less sticky.
The tablets may be manufactured by using any compacting process, such as
tabletting, briquetting, or extrusion, preferably tabletting. Suitable
equipment
includes a standard single stroke or a rotary press (such as Courtoy~, Korch~,
Manesty~, or Bonals~). The tablets prepared according to this invention
preferably
have a diameter of between 40mm and SOmm, and a weight between 25 and 60 g.
The compaction pressure used for preparing these tablets need not exceed 5000
kN/mz, preferably not exceed 3000 kN/m2, and most preferably not exceed 1000
kN/m2.
According to the present invention, the tablets are then coated with
dicarboxylic acid
so that the tablet does not absorb moisture, or absorbs moisture at only a
very slow
rate. The coating is also strong so that moderate mechanical shocks to which
the
tablets are subjected during handling, packing and shipping result in no more
than
very low levels of breakage or attrition. Finally the coating is preferably
brittle so
that the tablet breaks up when subjected to stronger mechanical shock.
Furthermore
it is advantageous if the coating material is dissolved under alkaline
conditions, or is
readily emulsified by surfactants. This avoids the deposition of undissolved
particles
or Iumps of coating material on the laundry Load. This may be important when
the
more water-insoluble dicarboxylic acids are used.
CA 02272642 2002-02-27
Water solubility is measured following the test protocol of ASTM E1148-87
entitled, "Standard Test Method for Measurements of Aqueous Solubility".
Suitable coating materials are C~-C" dicarboxylic acids. Particularly suitable
dicarboxvlic acids are selected from the group consisting of oxalic acid,
malonic
acid. succinic acid, glutaric acid. adipic acid, pimelic acid, suberic acid,
azelaic acid,
sebacic acid, undecanedioie acid, dodecanedioic acid, tridecanedioic acid and
mixtures thereof.
However the detergent tablets are prepared and in whatever from they are, they
are
then coated according to t1e present invention with a coating materyal having
a
melting point preferably of from 40 °C to 2()0 ''C.
The coating can be applied in a number of ways. Two preferred coating methods
are
a) coating with a molten material and b) coating with a solution of the
material.
In a), the coating material is applied at a temperature above its melting
point, and
solidifies on the tablet. In b), the coating is applied as a solution, the
solvent being
dried to leave a coherent coating. The substamiallv insoluble material can be
applied
to the tablet by, far example, spraying or dipping. Normally when the molten
material is sprayed on to the tablet, it will rapidly solidify to form a
coherent
coating. When tablets arc dipped into the molten material and then removed,
the
rapid cooling again cause: rapid solidification of the coating material.
Clearly
substantially insoluble materials having a melting point below 40 °C
are not
sufsciently solid at ambient ternperatures and it has been found that
materials having
a melting point above about 200 °C are nc~t practicable to use.
Preferably, the
materials melt in the range f~rcm 60 °C to 160 °C, more
preferably from 70 °C to 120
°C.
By "melting point" is meant the temperature at which the material when heated
slowly in, for example, a capillary tube becomes a clear liquid.
A. coating of any desired thickness can be applied according to the present
invention.
For most purposes, the coating forms from 1 ".~o to 10%, preferably from 1.5%
to 5%,
of the tablet weight.
The tablet coatings of the present invention are very hard and provide extra
strength
to the tablet.
CA 02272642 2002-02-27
6
In .a preferred embodiment of the present invention the fracture of the
coating in the
wash is improved by adding a disintegrant irr the coating. This disintegrant
will
swell once in contact with water and break the coating in small pieces. This
will
improve the dissolution c>f the coating in the wash solution. The disintegrant
is
suspended in the coating melt at a level of up to 30%. preferably between 5
and
20%, and most preferably between 5 and 10% by weight.
Possible disintegrants are described in Handbook of Pharmaceutical Excipients
( 1986). Examples of suitable disintegrants include starch: natural, modified
or
pregelatinized starch, sodium starch gluconate; gum: agar gum, guar gum.
locust
bean gum, karaya gum, pectin ~:um, tragacanth gtun; croscarmylose Sodium,
crospovidone, cellulose, carboxymethyl cellulose, algenic acid and :its salts
including
sodium alginate, silicone dioxide, clay, polyvinyipyrrolidone, soy
polysacharides,
ion exchange resins and mixtures thereof.
Depending on the composition of the starting material, and the shape of the
tablets,
the used compaction force will be adjusted to not affect the strength
(Diametral -
Fracture Stress), and the disintegration time in the washing machine. This
process
may be used to prepare homogenous or layered tablets of any size or shape.
Diametrical Fracture Stress (DFS) is a way to express the strength of a
tablet, it is
determined by the following equation
__ _2 F
p Dt
VVlrere F is the ma~timum force (Newton) to cause tensile failure (fracture)
measured
by a VK 200 tablet hardness tester supplied by Van Kell industries, Inc. D is
the
diameter of the tablet, and t the thickness of the tablet.
(Method Pharmaceutical Dosage Forms : Tablets Volume 2 Page 213 to 217)
The rate of disintegration of a detergent tablet can be determined in two ways
rn-t
a) In a "VAN KEL" Friabilator with "Vankel Type" drums.
- Put 2 tablets with a known weight and D.F.S in the Friabilator drum.
Rotate the drum for 20 rotations.
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WO 98/24874 PCT/US97/21042
7
- Collect all product and remaining tablet pieces from the Friabilator drum,
and
screen it on ~ mm, and through 1.7 mm
- Express as % residue on ~ mm and through 1.7 mm.
- The higher the % of material through 1.7 mm the better the disintegration.
b) In a washing machine according to the following method
- Take two tablets with a known weight and fracture stress, and put them at
the
bottom of a washing machine (i.e. a Bauknecht WA 950).
- Put a 3 kg mixed load on top of the tablets.
- Run a 30 °C short cycle (program 4) with city water.
- Stop the cycle after ~ min and check the wash load for undissolved tablet
pieces,
collect and weigh them, and record the percent residue left.
In another preferred embodiment of the present invention the tablets further
comprises an effervescent.
Effervescency as defined herein means the evolution of bubbles of gas from a
liquid,
as the result of a chemical reaction between a soluble acid source and an
alkali metal
carbonate, to produce carbon dioxide gas,
i.e. C6Hg07 + 3NaHC03 ~ Na3C6H507 + 3C02 ~ + 3H20
Further examples of acid and carbonate sources and other effervescent systems
may
be found in : (Pharmaceutical Dosage Forms : Tablets Volume 1 Page 287 to 291
)
An effervescent may be added to the tablet mix in addition to the detergent
ingredients. The addition of this effervescent to the detergent tablet
improves the
disintegration time of the tablet. The amount will preferably be between 5 and
20
and most preferably between 10 and 20% by weight of the tablet. Preferably the
effervescent should be added as an agglomerate of the different particles or
as a
compact, and not as separated particles.
Due to the gas created by the effervescency in the tablet, the tablet can have
a higher
D.F.S. and still have the same disintegration time as a tablet without
effervescency.
CA 02272642 2002-02-27
8
When the D.F.S. of the tablet with effervescence is kept the same as a tablet
without,
the disintegration of the tablet with effervescency will be faster.
Detersive surfactants
No:nlimiting examples of surfactants useful herein typically at levels from
about I%
to about 55%, by weight, include the conventional C 11 _C 1 g alkyl benzene
sulfonates ("LAS") and primary, branched-chain and random C 1 p-Cep alkyl
sulfates
("AS"), the C 10_C 18 secondary (2,a ) alkyl sulfates of the formula
CH3(CH2)x{CHOS03-M+) CH3 and CH3 (CH2)v(CHOS03-M+) CH2CH3 where
x and (y + 1 ) are integers of at least about 7, preferably at least about 9,
and M is a
water-solubilizing carton, especially sodium. unsaturated sulfates such as
oleyl
sulfate, the C 10-C 1 g alkyl alkox~~ sulfates ( "AEXS"; especially EO 1-7
ethoxy
sulfates), C 10_C 1 g alkyl alkoxy carboxylates (especially the EO I-5
ethoxycarboxylates), the C 10_ 1 g glycerol ethers, the C 10-C 1 g alkyl
polyglycosides
and their corresponding sulfated polyglycosides, and C 1 ~_C 1 g alpha-
sulfonated fatty
acid esters. If desired, the conventional nonionic and amphoteric slufactants
such as
the C 12_C 18 alkyl ethoxylates ("AE") including the so-called narc~ow peaked
alkyl
ethoxylates and C6-C 1 ~ alkyl phenol alkoxylates (especially ethoxylates and
mixed
ethoxy/propoxy), C 1 ~_C 1 g betaines and sulfobetaines ("sultaines"), C 10-C
1 g amine
oxides, and the like, can alsu be included in the overall compositions. The
C10-C18
N-alkyl polyhydroxy fatty acid amides can also be used. Typical examples
include
the C 12-C 1 g N-methylglucamides. See WO 92/06154. Other sugar-derived
surfactants include the N-alkoxy polyhydroxy fatty acid amides, such as C 10-C
18
N-(3-methoxypropyl j glucamide. The N-propyl through N-hexyl C 12-C 18
glucamides can be used for low sudsing. C 10-Cep conventional soaps may also
be
used. If high sudsing is desired, the branched-chain C 10-C 16 soaps may be
used.
Mixtures of anionic and nonionic surfactants are especially useful. Other
conventional useful surfactants are listed in standard texts.
Builders
Detergent builders can optionally be included in the compositions herein to
assist in
controlling mineral hardness. Inorganic as well as organic builders can be
used.
Builders are typically used in fabric laundering compositions to assist in the
removal
of particulate soils.
The level of builder can vary widely depending upon the end use of the
composition.
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WO 98/24874 PCT/US97/21042
9
Inorganic or P-containing detergent builders include, but are not limited to,
the alkali
metal, ammonium and alkanolammonium salts of polyphosphates (exemplified by
the tripolyphosphates, pyrophosphates, and glassy polymeric meta-phosphates),
phosphonates, phytic acid, silicates, carbonates (including bicarbonates and
sesquicarbonates), sulphates, and aluminosilicates. However, non-phosphate
builders are required in some locales. Importantly, the compositions herein
function
surprisingly well even in the presence of the so-called "weak" builders (as
compared
with phosphates) such as citrate, or in the so-called "underbuilt" situation
that may
occur with zeolite or layered silicate builders.
Examples of silicate builders are the alkali metal silicates, particularly
those having
a Si02:Na20 ratio in the range 1.6:1 to 3.2:1 and layered silicates, such as
the
layered sodium silicates described in U.S. Patent 4,664,839, issued May 12,
1987 to
H. P. Rieck. NaSKS-6 is the trademark for a crystalline layered silicate
marketed by
Hoechst (commonly abbreviated herein as "SKS-6"). Unlike zeolite builders, the
Na
SKS-6 silicate builder does not contain aluminum. NaSKS-6 has the delta-
Na2Si05
morphology form of layered silicate. It can be prepared by methods such as
those
described in German DE-A-3,417,649 and DE-A-3,742,043. SKS-6 is a highly
preferred layered silicate for use herein, but other such layered silicates,
such as
those having the general formula NaMSix02x+1'YH20 wherein M is sodium or
hydrogen, x is a number from 1.9 to 4, preferably 2, and y is a number from 0
to 20,
preferably 0 can be used herein. Various other layered silicates from Hoechst
include NaSKS-5, NaSKS-7 and NaSKS-11, as the alpha, beta and gamma forms.
As noted above, the delta-Na2Si05 (NaSKS-6 form) is most preferred for use
herein. Other silicates may also be useful such as for example magnesium
silicate,
which can serve as a crispening agent in granular formulations, as a
stabilizing agent
for oxygen bleaches, and as a component of suds control systems.
Examples of carbonate builders are the alkaline earth and alkali metal
carbonates as
disclosed in German Patent Application No. 2,321,00i published on November 15,
1973.
Aluminosilicate builders are useful in the present invention. Aluminosilicate
builders are of great importance in most currently marketed heavy duty
granular
detergent compositions, and can also be a significant builder ingredient in
liquid
detergent formulations. Aluminosilicate builders include those having the
empirical
formula:
CA 02272642 1999-OS-20
WO 98/Z4874 PCT/US97/Z1042
Mz(zA102)y]~xH20
wherein z and y are integers of at least 6, the molar ratio of z to y is in
the range
from 1.0 to about 0.5, and x is an integer from about 15 to about 264.
Useful aluminosilicate ion exchange materials are commercially available.
These
aluminosilicates can be crystalline or amorphous in structure and can be
naturally-
occurring aluminosilicates or synthetically derived. A method for producing
aluminosiIicate ion exchange materials is disclosed in U.S. Patent 3,985,669,
Krummel, et al, issued October 12, 1976. Preferred synthetic crystalline
aluminosilicate ion exchange materials useful herein are available under the
designations Zeolite A, Zeolite P (B), Zeolite MAP and Zeolite X. In an
especially
preferred embodiment, the crystalline aluminosilicate ion exchange material
has the
formula:
Na 12 ~(A102) 12(Si02) 12~'~20
wherein x is from about 20 to about 30, especially about 27. This material is
known
as Zeolite A. Dehydrated zeolites (x = 0 - 10) may also be used herein.
Preferably,
the aluminosilicate has a particle size of about 0.1-10 microns in diameter.
Organic detergent builders suitable for the purposes of the present invention
include,
but are not restricted to, a wide variety of polycarboxylate compounds. As
used
herein, "polycarboxylate" refers to compounds having a plurality of
carboxylate
groups, preferably at least 3 carboxylates. Polycarboxylate builder can
generally be
added to the composition in acid form, but can also be added in the form of a
neutralized salt. When utilized in salt form, alkali metals, such as sodium,
potassium, and lithium, or alkanolammonium salts are preferred.
Included among the polycarboxylate builders are a variety of categories of
useful
materials. One important category of polycarboxylate builders encompasses the
ether polycarboxylates, including oxydisuccinate, as disclosed in Berg, U.S.
Patent
3,128,287, issued April 7, 1964, and Lamberti et al, U.S. Patent 3,635,830,
issued
January 18, 1972. See also "TMS/TDS" builders of U.S. Patent 4,663,071, issued
to
Bush et al, on May 5, 1987. Suitable ether polycarboxylates also include
cyclic
compounds, particularly alicyclic compounds, such as those described in U.S.
Patents 3,923,679; 3,835,163; 4,158,635; 4,120,874 and 4,102,903.
CA 02272642 2002-02-27
t1
Other useful detergency builders include the ether hydroxypolycarboxylates,
copoly-
mers of malefic anhydride with ethylene or vinyl methyl ether. l, 3, ~-
trihydroxy
benzene-2, 4, 6-trisulphonic acid, and carboxymethyloxysuccinic acid, the
various
alkali metal, ammonium and substituted ammonium salts of polyacetic acids such
as
ethvlenediamine tetraacetic acid and nitrilotriacetic acid, as well as
polycarboxylates
such as mellitic acid, succinic acid, oxydisuccinic acid, polymaleic acid,
benzene
1.3..5-tricarboxylic acid. canboxymethyloxvsuccinic acid, and soluble salts
thereof.
Citrate builders, e.g., citric acid and soluble salts thereof (particularly
sodium salt),
are polycarboxyiate builders of panicular importance for heavy duty liquid
detergent
formulations due to their availability from renewable resources and their
biodegradability. Citrates can also be used in granular compositions,
especially in
combination with zeolite and/or layered silicate builders. Oxydisuccinates are
also
especially useful in such compositions and combinations.
Also suitable in the detergent compositions of the present invention are the
3,3-
dicarboxv-4-oxa-1.6-hexanedioates and the related compounds disclosed in U.S.
Patent 4.566,984, Bush, issued January 28, 1986. Useful succinic acid builders
include the CS-C2p alkyl and alkenyl succinic acids and salts thereof. A
particularly
preferred compound of this type is dodecenyfsuccinic acid. Specific examples
of
succinate builders include: laurvlsuccinate, myristylsuccinate,
palmitylsuccinate, 2-
dodecenylsuccinate (preferred), 2-pentadecenylsuccinate, and the like.
Laurylsuccinates are the preferred builders of this group, and .are described
in
European Patent Application 0,200.263, published November 5, 1986.
Other suitable polycarboxylates are disclosed in IJ.S. Patent 4.144.226,
Crutchfield
et al, issued March 13, 1979 and in U.S. Patent 3,308,067, Diehl, issued March
7,
1967. See also Diehl U.S. Patent 3,723.322.
Fatay acids, e.g., C 12-C 18 monocarboxylic acids, can also be incorporated
into the
compositions alone, or in combination with the aforesaid builders, especially
citrate
and/or the succinate builders, to provide additional builder activity. Such
use of
fatty acids will generally result in a diminution of sudsing, which should be
taken
into account by the formulator.
In situations where phosphorus-based builders can be used, and especially in
the for-
mulation of bars used for hand-laundering operations, the various alkali metal
phosphates such as the well-known sodium tripolyphosphates, sodium
pyrophosphate and sodium orthophosphate can be used. Phosphonate builders such
CA 02272642 2002-02-27
12
as ethane-1-hydroxy-1.1-diphosphonate and other known phosphonates (see, for
example. U.5. Patents 3.19.581; 3,213.030; 3.422.021; 3,400,148 and 3,422.137)
can also be used.
Bleach
l~he detergent compositions herein nuay optionally contain bleaching agents or
bleaching compositions containing a bleaching agent and one or more bleach
activators. When present. bleaching agents will typically be at levels of from
about
1'% to about 30%, more typically liom aibout s% to about 20%, of the detergent
composition, especially for fabric laundering. If present, the amount of
bleach
activators will typically be from about 13.1°-~ to about 60%, more
typically from
about 0.5% to about 40% of the bleaching composition comprising the bleaching
agent-plus-bleach activator.
The bleaching agents used herein can be any of the bleaching agents useful for
detergent compositions in textile cleaning, hard surface cleaning, or other
cleaning .
purposes that are now known or become known. These include oxygen bleaches as
well as other bleaching agents. Perborate bleaches, e.g., sodium perborate
(e.g.,
mono- or tetra-hydrate) can be used herein.
Another category of bleaching agent that can be used without restriction
encompasses percarboxylic acid bleaching, aLents and salts thereof. Suitable
examples of this class of agents include magnesium monoperoxyphthalate
hexahydrate, the magnesium salt of metachloro perbenzoic acid, 4-nonylamino-4-
oxoperoxybutyric acid a:nd diperoxydodecanedioic acid. Such bleaching agents
are
disclosed in U.S. Patent 4,483,781. 1-Iartman, issued November 20, 1984, U.S.
Patent
I'Jo. 4,806,632, issued February 21, 1~~89, European Patent Application
0,133,354, Banks et al, published February 20, 1985, and U.S. Patent
4,412,934,
C:hung et al, issued November i, 1983. 1-lighly preferred bleaching agents
also
include 6-nonylamino-ti-oxoperoxycaproic acid as described in U.S. Patent
4,634,551, issued January 6, 1987 to Burns et al.
Peroxygen bleaching agents can also be used. Suitable peroxygen bleaching
compounds include sodium carbonate peroxyhydrate and equivalent "perearbonate"
bleaches, sodium pyrophosphate peroxyhvdrate, urea peroxyhydrate, and sodium
Tn~
peroxide. Persulfate bleach (e.g., OXONL., manufactured commercially by
DuPont)
can also be used.
CA 02272642 2002-02-27
13
A preferred percarbonate bleach comprises dn~ panicles having an average
particle
size in the range from about 500 micrometers to about 1,0U0 micrometers, not
more
than about 10% by weight of said particles being smaller than about 200
micrometers and not more than about 10% by weight of said particles being
larger
than about 1.250 micrometers. C>ptionallv, the percarbonate can be coated with
silicate. borate or water-soluble surfactants. Percarbonate is available from
various
commercial sources such as FMC. Solvay and °hokai Denka.
Mixtures of bleaching agents can also be used.
Peroxygen bleaching agents, the perborates. the percarbonates, etc:., are
preferably
combined with bleach activators, which lead to the in situ production in
aqueous
solution (i.e., during the washing process) of the peroxy acid corresponding
to the
bleach activator. Various nonlimiting examples of activators are disclosed in
U.S.
Patent 4,915,854, issued At~ril 10. 1990 to lvlao et al, and U.S. Patent
4,412,934.
The nonanoyloxvbenzene sulfonate (NOBS) and tetraacetyl ethylene diamine
(TAED) activators are typical. and mixtures thereof can also be used. See also
U.S.
4.634,551 for other typical bleaches and activators useful herein.
Highly preferred amido-derived bleach activators are those of the formulae:
RIN(R5)C(O)R2C(O)L or RIC(O)N(R5)R2C(O)L
wherein RI is an alkyl group containing from about 6 to about 12 carbon atoms,
R2
is an alkylene containing from 1 to about fi carbon atoms, R5 is H or alkyl,
aryl, or
alkaryl containing from abc:~ut 1 to about 10 carbon atoms, and L is any
suitable
leaving group. A leaving croup is any group that is displaced from the bleach
activator as a consequence of the nucleophilic attack on the bleach activator
by the
pexhydrolysis anion. A preferred leaving group is phenyl sulfonate.
Preferred examples of bleach activators csf the above formulae include (6-
octanarnido-caproyl)oxybenzenesuifonate, (6-nonanamidocaproyl)oxybenzenesul-
fonate, (6-decanamido-caproyl)oxybenzenesulfonate, and mixtures thereof as
described in U.S. Patent 4.,6:34,551.
Another class of bleach activators comprises the benzoxazin-type activators
disclosed by Hodge et al in U.S. Patent 4,966,723, issued October 30, 1990.
A highly preferred activator of the benzoxazin-type is:
CA 02272642 2002-02-27
14
O
~i
Cw
O
,,C
~J
N
Still another class of preferred bleach activators includes the acyl lactam
activators,
especially acyl caprolactams and aryl valerolactams of the formulae:
O O
II II
0 C ~-C HZ--C H2 O C-C H2- ~ H2
.,
R6-C-N.~ , CHI R~-C-Nw
C H~-C H2 C H2--C H2
wherein R6 is H or an alkyl, aryl, alkoxyaryl, or alkaryl group containing
from 1 to
about 12 carbon atoms. highly preferred lactam activators include benzoyl
caprolactam, octanoyl caprolactam, 3,5,5-trimethylhexanoyl caprolactam,
nonanoyl
caprolactam, decanoyl caprolactam, undecenoyl caprolactam, benzoyl
valerolactam,
octanoyl valerolactam, decanoyl valerolactam, undecenoyl valerelactam,
nonanoyl
va,lerolactam, 3,5,5-trimethylhexanoyl valerolactam and mixtures thereof. See
also
U.S. Patent 4,545,784, issued to Sanderson, October 8, 1985, which discloses
acyl
caprolactams, including benzoyl caprolactam, adsorbed into sodium perborate.
F3 leaching agents other than oxygen bleac;~ing agents are also known in the
art and
ca.n be utilized herein. One type of non-oxygen bleaching agent of particular
interest
includes photoactivated bleaching af7ents such as the sulfonated zinc and/or
aluminum phthalocyanines. See U.S. Patent 4,033,718, issued July 5, 1977 to
Holcombe et al. If used, detergent compositions will typically contain from
about
0.025% to about 1.25%, by weight, of such bleaches, especially sulfonate zinc
phthalocyanine.
If desired, the bleaching compounds can be catalyzed by means of a manganese
compound. Such compounds are well known in the art and include, for example,
the
manganese-based catalysts disclosed in L1.S. Pat. 5,246,621, U.S. Pat.
5,244,594;
U.S. Pat. 5,194,416; U..S. Pat. 5,114,606; and European Pat. App. Pub. Nos.
549,271A1, 549,272A1, 544,440A2, and 544,490A1; Preferred examples of these
catalysts include MnIV~(u-O)3(1,4,7-trimethyl-1,4,7-triazacyclononane)2(PF6)2,
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WO 98/24874 PCT/US97/21042
MnI112(u-O)1(u-OAc)~(1,4,7-trimethyl-1,4,7-triazacyclononane)2_(CI04)2,
MnIV4(u-O)6(1,4,7-triazacyclononane)4(CI04)4, MnIIIMnIV4(u-O)1(u-OAc)2_
(I,4,7-trimethyl-i,4,7-triazacyclononane)2(C104)3, MnIV(1,4,7-trimethyl-1,4,7-
triazacyclononane)- (OCH3)3(PF6), and mixtures thereof. Other metal-based
bleach
catalysts include those disclosed in U.S. Pat. 4,430,243 and U.S. Pat.
5,114,611.
The use of manganese with various complex Iigands to enhance bleaching is also
reported in the following United States Patents: 4,728,455; 5,284,944;
5,246,612;
5,256,779; 5,280,1 I 7; 5,274,147; 5,153, I 61; and 5,227,084.
As a practical matter, and not by way of limitation, the compositions and
processes
herein can be adjusted to provide on the order of at least one part per ten
million of
the active bleach catalyst species in the aqueous washing liquor, and will
preferably
provide from about 0.1 ppm to about 700 ppm, more preferably from about I ppm
to
about 500 ppm, of the catalyst species in the laundry liquor.
Enzymes
Enzymes can be included in the formulations herein for a wide variety of
fabric
laundering purposes, including removal of protein-based, carbohydrate-based,
or
triglyceride-based stains, for example, and for the prevention of refugee dye
transfer,
and for fabric restoration. The enzymes to be incorporated include proteases,
amylases, lipases, cellulases, and peroxidases, as well as mixtures thereof.
Other
types of enzymes may also be included. They may be of any suitable origin,
such as
vegetable, animal, bacterial, fungal and yeast origin. However, their choice
is
governed by several factors such as pH-activity and/or stability optima,
thermostability, stability versus active detergents, builders and so on. In
this respect
bacterial or fungal enzymes are preferred, such as bacterial amylases and
proteases,
and fungal cellulases.
Enzymes are normally incorporated at levels sufficient to provide up to about
5 mg
by weight, more typically about 0.01 mg to about 3 mg, of active enzyme per
gram
of the composition. Stated otherwise, the compositions herein will typically
comprise from about 0.001 % to about 5%, preferably 0.01 %-1 % by weight of a
commercial enzyme preparation. Protease enzymes are usually present in such
commercial preparations at levels su~cient to provide from 0.005 to 0.1 Anson
units (AU) of activity per gram of composition.
Suitable examples of proteases are the subtilisins which are obtained from
particular
strains of B. subtilis and B. licheniforms. Another suitable protease is
obtained from
CA 02272642 2002-02-27
16
a strain of Bacillus, having maximum activity throughout the pH range of 8-12,
developed and sold by Novo Industries A,'S under the registered trade mark
ESPERASE. The preparatic>n of this enz~~me and analogous enzymes is described
in
British Patent Speciiicatian No. 1,243,784 of Novo. Proteolvtic enzymes
suitable
for removing protein-based ~a<iins that are commercially available include
those sold
under the trademarks Al.<=ALASE and SAVINASE by Novo Industries A/S
(Denmark) and MAXATASE by International Bio-Synthetics, Inc. (The
Netherlands). Other proteases include Protease A (see European Patent
Application
130,756, published January O, 1985) and Protease B (see European Patent
Application 251,446, published January 7, 1988, and European Patent
Application 130,756, Bott et al, published January 9, 1985).
Amylases include, for example, a-amv_ lases described in British Patent
Specification
'rM
No. 1.296.839 (Novo), iR.~PIDASE, International Bio-Synthetics, Inc. and
'1' M
TF;RMAMYL, Novo Industries.
The cellulase usable in the present invention include both bacterial or fungal
cellulase. Preferably, they will have a pH optimum of between 5 and 9.5.
Suitable
cellulases are disclosed in U.S. Patent 4,435,307, Barbesgoard et al, issued
March 6,
1984, which discloses fungal cellulase produced from Humicola insolens and
Humicola strain DSM1800 or a ccllulase 212-producing fungus belonging to the
genus Aeromonas. <ind cellulase extracted from the hepatopanereas of a marine
mollusk (Dolabella Auricula Solander). suitable cellulases are also disclosed
in GB
TM
A-2.075.028; GB-A-2.095.?75 and DE-OS-'?.247.832. CAREZYME (Novo) is
especially useful.
Suitable lipase enzymes for detergent usage include those produced by
microorganisms of the Pseudomonas group, such as Pseudomonas stutzeri ATCC
19.154, as disclosed in British Patent 1.372 ,034. See also lipases in
Japanese Patent
Application 53,20487, laid open to public inspection on February 24, 1978.
This
lipase is available from Amano Pharmaceutical Co. Ltd., Nagoya, Japan, under
the
trade mark Lipase P "Arrtano," hereinafter referred to as "Amano-P." Other
commercial lipases include Arnano-CES, lipases ex Chromobacter viscosttm, e.g.
Clromobacter viscosum vac, lipolyticum NRRLB 3673, commercially available
from Toyo Jozo Co., Tagata, Japan; and further Chromobacter viscosturt lipases
from U.S. Biochemical Ccnp., U.S.A. and Disov_ nth Co., The Netherlands, and
'1' M
lipases ex Pseudomonas gladioli. The LII'OI~ASE. enzyme derived from Humicola
CA 02272642 2002-02-27
17
lanuginosa and commercially available from Novo (see also EPO 341,947) is a
preferred lipase for use herein.
Peroxidase enzymes are used in combination with oxygen sowces, e.g.,
percarbonate, perborate, persulfate, hydrogen peroxide, etc. They are used for
"soiution bleaching," i.e. to prevent transfer of dyes or pigments removed
from
substrates during wash operations to other substrates in the wash solution.
Peroxidase enzymes are known in the art, and include, for example, horseradish
peroxidase, ligninase, and haloperoxidase such as chloro- and bromo-
peroxidase.
Peroxidase-containing detergent compositions are disclosed, for example, in
PCT
International Application W() 89/099813, published October 19, 1989, by O.
Kirk,
assigned to Novo Industries A/S.
A vY~ide range of enzyme materials ar d means for their incorporation into
synthetic
detevrgent compositions are also disciosed in U.S. Patent 3,553,139, issued
January 5,
1971 to McCarty et al. 1=;nzymes are further disclosed in U.S. Patent
4,101,457,
Place et al, issued July 18, 1978, and in IJ.S. Patent 4,507,219, Hughes,
issued
March 26, 1985. both. Enzyme materials useful for liquid detergent
formulations,
and their incorporation into such formulations, are disclosed in U.S. Patent
4,261,868, Hora et al, issued April 14, 1981. F;nzymes for use in detergents
can be
stabilized by various techniques. Enzyme stabilization techniques are
disclosed and
exemplified in U.S. Patent 3,600,319, issued ~'~ugust 17, 1971 to Ciedge, et
al, and
European Patent Application Publication No. 0 199 405, published October 29,
1986, Venegas. Enzyme stabilization systems are also described, for example,
in
U.S. Patent 3,519,570.
Other components which are comonly used in detergent compositions and which
may be incorpoated into the detergent tablets of the present invention include
chelating agents, soil release agents, soil antircdeposition agents,
dispersing agents,
brighteners, suds suppressors, fabric softeners, dye transfer inhibition
agents and
periiunes.
CA 02272642 1999-OS-20
WO 98/24874 PCT/US97/21042
18
EXAMPLES
Ex. 1 Ex. 2
Anionic Agglomerates 25.00 20.00
Nonionic Agglomerate S.S3 4.42
Bleach Activator Agglomerates5.69 4.55
Zinc Phthalocyanine sulphonate0.03 0.02
encapsulate
Suds Supressor 3.23 2.58
Dried Zeolite 6.30 5.04
Layered Silicate 13.69 10.95
Dye transfer Inhibitor 0.13 0.10
Agglomerate
Perfume Encapsulates 0.23 0.18
Nonionic Paste Spray-on 5.43 4.34
Fluorescer 0.26 0.21
Sodium carbonate 4.68 3.74
Sodium percarbonate 19.78 15.86
Sodium HEDP 0.79 0.63
Soil Release polymer 0.18 0.14
Perfume 0.33 0.26
Protease 0.86 0.69
Cellulase 0.25 0.20
Lipase 0.21 0.17
Amylase 0.70 0.56
Adipic Acid 6.70 6.70
Effervescency Compact - 18.66
TOTAL 100.00 100.00
Anionic agglomerates comprise 38% anionic surfactant, 22% zeolite and 40%
carbonate.
Nonionic agglomerates comprise 26% nonionic surfactant, 48% zeolite and 26%
carbonate.
Bleach activator agglomerates comprise 81 % TAED, 17% acryiic/maleic copolymer
(acid form) and 2% water.
Zinc PhthaIocyanine sulphonate encapsulates are 10% active.
Suds suppressor comprises 11.5% silicone oil (ex Dow Corning), and 88.5%
starch.
Layered silicate comprises 78% SKS-6, ex Hoechst, 22% citric acid.
CA 02272642 1999-OS-20
WO 98/24874 ~ PCT/US97/21042
19
Dye transfer inhibitor agglomerates comprise 21% PVNO/PVPVI, 61% zeolite and
18% carbonate.
Perfume encapsulates comprise 50% perfume and 50% starch.
Nonionic paste spray-on comprises 67% C 12-C 15 AES (alcohol with an average
of
ethoxy groups per molecule), 24% N-methyl glucose amide and 9% water.
Effervescent compact comprises 54.5% sodium bicarbonate and 45.5% citric acid.
All the particulate materials of Example 1, except for the dried zeolite, were
mixed
together in a mixing drum to form a homogeneous particulate mixture, during
this
mixing the spray-ons were carried out. After the spray-ons the dusting was
carried
out with the dried zeolite.
A first series of tablets were made the following way, about 37.5 g. of the
mixture
was introduced into a mould of circular shape with a diameter of 4.5 cm, and
compressed with a force of 0.5 kN. or about 30 Newton/cm2, to give tablets of
about
2.2 cm height and a density of about 1.1 g./cc. The tensile strength of the
tablet was
3.5 kPa.
Adipic acid was heated in a thermostatic bath till 170 °C with gentle
stirring until
molten. The molten product was clear liquid. The tablets prepared as above
were
then dipped into the liquid to give the final coated tablet, this tablet had a
total
weight of 40.2 g, and a tensile strength of 6.5 kPa.
An second series of tablets was made with a compaction force of 1 kN. or about
63
N/cm2 to give tablets of about 2.0 cm height, a density of about 1.2 g./cc,
and a
tensile strength of 9.0 kPa.
After coating with Adipic Acid the tablets had a weight of 40.2 g, and the
tensile
strength was 15.5 kPa.
A third series of tablets was made with a compaction force of 1.5 kN. or about
95N/cm2 to give tablets of about 1.9 cm height, a density of about 1.3 g./cc,
and a
tensile strength of 12.9 icPa.
After coating with Adipic Acid the tablets had a weight of 40.2 g, and the
tensile
strength was 19.5 kPa.
CA 02272642 1999-OS-20
WO 98/24874 PCT/US97/21042
Example 2
Mixing according to the method described in Example 1, after the dusting the
effervescency granules were added to the mix drum, and a final mix was made.
Tabletting and coating was carried out according to the method described in
Example 1
A first series of tablets was made with a Compaction Force of 1 kN. or about
63
Newton/cm2, to give tablets of about 2.2 cm height, a density of about 1.1
gr./cc,
and a tensile strength of 4.5 kPa.
After coating with Adipic acid the tablets had a weight of 40.2 g, and the
tensile
strength was 10.4 kPa.
A second series of tablets was made with a compaction force of 1.5 kN. or
about 95
N/cm2 to give tablets of about 2.1 cm height, a density of about 1.2 gr./cc,
and a
tensile strength of 8.5 kPa.
After coating with Adipic Acid the tablets had a weight of 40.2 g, and a
tensile
strength was 14.5 kPa.
An third series of tablets was made with a compaction force of 2.5 kN. or
about 160
N/cm2 to give tablets of about 2.0 cm height, a density of about 1.2 g./cc,
and a
tensile strength of 15.7 kPa.
After coating with Adipic Acid the tablets had a weight of 40.2 g, and the
tensile
strength increased to 21.3 kPa.
Example 1 was repeated replacing the adipic acid by glutaric acid. The
glutaric acid
was heated in a thermostatic bath to 120°C with gentle stirring until
molten. The
final tensile strength of the three series of tablets was 10.4 kPa, 17.3 kPa
and 22.5
kPa respectively.
Example 2 was repeated replacing the adipic acid by glutaric acid. The
glutaric acid
was heated in a thermostatic bath to 120°C with gentle stirring until
molten. The
final tensile strength of the three series of tablets was 11.3 kPa, 16.9 kPa
and 23.0
kPa respectively.
Similar results were obtained by replacing the adipic acid of examples 1 or 2
with
any one of : azelaic acid, suberic acid or sebacic acid.
