Note: Descriptions are shown in the official language in which they were submitted.
CA 02273325 1999-OS-20
WO 98/24875 PCT/US97/21044
1
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 unix 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.
CA 02273325 2002-02-27
2
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, PVPV A, and sugar.
WO 9S/18215, published on 6th July 1995, 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 hydrophobic or substantially water-
insoluble
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, but 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 objective 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
The objective is achieved by providing a coating which consists of a material,
or
mixture of materials, which is substantially water-insoluble in water at
25°C. The
coating is hydrophobic which acts as a barrier to moisture and gives better
stability to
ingredients such as bleach and enzymes.
Preferred coating materials include fatty acids, fatty alcohols, diols, esters
and ethers.
Most preferred are C,2-C22 fatty acids, adipic acid, C8-Ci3 dicarboxylic acids
and
mixtures thereof
In a preferred aspect of the invention there is provided a tablet comprising a
core and a
coating, the core being formed by compressing a particulate material, the
particulate
material comprising surfactant and detergent builder, characterised in that
the coating
CA 02273325 2002-02-27
3
comprises a material, or mixture of materials having a melting point of from
40°C to
180°C, wherein the materials, or mixture of materials are substantially
insoluble in
water at 25°C, wherein said tablet further comprises: (i) a water-
swellable distintegrant
present in said coating; and (ii) an effervescent present in said core.
In a further aspect of the invention there is provided a process for making a
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 t~:> 180°C; (c) allowing the molten
coating material to
solidify; characterised in that tine coating material comprises a material, or
mixture of
materials, which is substantially insoluble in water at 25°C, and the
tablet further
comprises: (i) a water-swellable distintegrant present in said coating; and
(ii) an
effervescent present in said core.
In an alternative to this embodiment of the invention there is provided a
process for
making a 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 180°C and being dissolved in a solvent; (c)
allowing the solvent to
evaporate; characterised in that the coating material comprises a material, or
mixture of
materials, which is substantially insoluble in water at 25°C, and the
tablet further
comprises: (i) a water-swellal>le distintegrant present in said coating; and
(ii) an
effervescent present in said core.
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 pharnnaceutical industn~. Any liquid ingredients,
for example
the surfactant or suds suppresser, can be incorporated in a conventional
manner into the
solid particulate ingredients. Preferably the principal ingredients, are used
in particulate
form.
CA 02273325 2002-02-27
3a
In particular for laundry tablets, the ingredients such as builder and
surfactant can be
spray-dried in a conventional manner and then compacted at a suitable
pressure.
The detergent tablets can be made in any size or shape and can, 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. 'fhe term "builder" is intended to mean all
materials
CA 02273325 1999-OS-20
WO 98/24875 ' PCT/US97/21044
4
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
and/or
Lodige~ KM mixers). Other suitable processes include fluid bed processes,
compaction processes (e.g. roil compaction), extrusion, as well as any
particulate
material made by any chemical process like flocculation, crystallisation
sentering, 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 beat, 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/m2, 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 a coating
that is
substantially insoluble so that the tablet does not absorb moisture, or
absorbs
CA 02273325 2002-02-27
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 flan 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 Lumps of coating material on the
laundry load.
This may be important when the coating material is completely insoluble (for
example
less than 1 g/1) in water.
As defined herein "substantially insoluble" means having a very low solubility
in
water. This should be understood to mean having a solubility in water at
25°C of less
than 20 g/L, preferably less than 5 g/1, and more preferably less than 1 g/1.
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 fatty acids, adipic acid and Cg-y3 dicarboxylic
acids,
fatty alcohols, diols, esters and ethers. Preferred fatty acids are those
having a carbon
chain length of from C~2 to Czz and most preferably from Cis to C22. Preferred
dicarboxylic acids are adipic acid (C6), suberic acid (C8), azelaic acid (C9),
sebacic
acid (C,o)~ undecanedioic acid (C,~), dodecanedioic acid (C,2) and tr-
idecanedioic
acid (C~3). Preferred fatty alcohols are those having a carbon chain length of
from
C,2 to C22 and most preferably from C,4 to C~g. Preferred diols are 1,2-
octadecanediol and 1,2-hexadecanediol. Preferred esters are tristearin,
tripalmitin,
methylbehenate, ethylstearate. Preferred ethers are diethyleneglycol mono
hexadecylether, diethyleneglycol mono octadecylether, diethyleneglycol mono
tetradecylether, phenylether, ethyl naphtyl ether, 2 methoxynaphtalene, beta
naphtyl
methyl ether and glycerol monooctadecylether. Otter preferred coating
materials
include dimethyl 2,2 propanol, 2 hexadecanol, 2 octadecanone, 2 hexadecanone,
2,
1 S hexadecanedione and 2 hydroxybenzyl alcohol.
However the detergent tablets are prepared and in whatever from they are, they
are
then coated according to the present invention with a hydrophobic material
having a
melting point preferably of from 40 °C to 180 °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.
CA 02273325 1999-OS-20
WO 98/24875 PCT/US97121044
6
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 substantially insoluble material can be
applied
to the tablet by, for 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 are dipped into the molten material and then removed, the rapid
cooling again
causes rapid solidification of the coating material. Clearly substantially
insoluble
materials having a melting point below 40 °C are not sufficiently solid
at ambient
temperatures and it has been found that materials having a melting point above
about
180 °C are not practicable to use. Preferably, the materials melt in
the range from 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% 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.
In a preferred embodiment of the present invention the fracture of the coating
in the
wash is improved by adding a disintegrant in the coating. This disintegrant
will swell
once in contact with water and break the coating in small pieces. This will
improve
the dissolution of 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 gum, tragacanth gum; croscarmylose Sodium,
crospovidone, cellulose, carboxymethyl cellulose, algenic acid and its salts
including
sodium alginate, silicone dioxide, clay, polyvinylpyrrolidone, soy
polysacharides, ion
exchange resins and mixtures thereof.
CA 02273325 2002-02-27
7
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
_ 2F
p Dt
Where F is the maximum 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
TM
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.
- Collect all product and remaining tablet pieces from the Friabilator drum,
and
screen it on 5 mm, and through 1.7 mm
- Express as % residue on 5 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 5 min and check the wash load for undissolved tablet
pieces,
collect and weigh them, and record the percent residue left.
CA 02273325 1999-OS-20
WO 98/24875 PCT/US97/21044
8
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 T + 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.
When the D.F.S. of the tablet with effervescency is kept the same as a tablet
without,
the disintegration of the tablet with effervescency will be faster.
Detersive surfactants
Nonlimiting examples of surfactants useful herein typically at levels from
about 1% to
about 55%, by weight, include the conventional C11_Clg alkyl benzene
sulfonates
("LAS") and primary, branched-chain and random C10_C2p alkyl sulfates ("AS"),
the
C10_Clg secondary (2,3) alkyl sulfates of the formula CH3(CH2~(CHOS03..M+)
CH3 and CH3 (CH2h,(CHOS03~vI+) CH2CH3 where x and (y + 1) are integers of
at least about 7, preferably at least about 9, and M is a water-solubilizing
cation,
especially sodium, unsaturated sulfates such as oieyl sulfate, the C 10_C 1 g
alkyl
alkoxy sulfates ("AEXS"; especially EO 1-7 ethoxy sulfates), C 1 p_C 1 g alkyl
alkoxy
carboxylates (especially the EO 1-5 ethoxycarboxylates), the C10-18 glycerol
ethers,
the C 10_C 1 g alkyl polyglycosides and their corresponding sulfated
polyglycosides,
and C 12_C 1 g alpha-sulfonated fatty acid esters. If desired, the
conventional nonionic
and amphoteric surfactants such as the C 12_C 1 g alkyl ethoxylates ("AE")
including
CA 02273325 2002-02-27
9
the so-called narrow peaked alkyl ethoxylates and C6-C12 alkyl phenol
alkoxylates
(especially ethoxylates and mixed ethoxy/propoxy), C 12-C 1 g betaines and
sulfobetaines ("sultaines"), C 1 p-C 1 g amine oxides, and the like, can also
be included
in the overall compositions. The C I p-C 1 g N-alkyl polyhydroxy fatty acid
amides can
also be used. Typical examples include the C 12-C 1 g N-methylglucamides. See
WO
92/a6I54. Other sugar-derived surfactants include the N-alkoxy polyhydroxy
fatty
acid amides, such as C I O-(:~ l g N-(3-methoxypropyl) glucamide. The N-propyl
through N-hexyl C 12-C 1 g glucamides can be used for low sudsing. C10-C20
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
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 mete-phosphates),
phosphonates, physic acid, silicates, carbcmates (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:I 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
CA 02273325 1999-OS-20
WO 98/24875 PCT/L1S97/21044
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 ~'~'herein 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. 2,321,001 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:
Mz(zA102h,1.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 aiuminosilicates or synthetically derived. A method for producing
aluminosilicate ion exchange materials is disclosed in U.S. Patent 3,985,669,
Klvmmel, 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:
Nal2~~~02) l2~Si02)12)'~20
CA 02273325 1999-OS-20
WO 98/24875 PCT/US97/21044
11
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 "TMSfTDS" builders ofU.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.
Other useful detergency builders include the ether hydroxypolycarboxylates,
copoly-
mers of malefic anhydride with ethylene or vinyl methyl ether, 1, 3, 5-
trihydroxy
benzene-2, 4, 6-trisulphonic acid, and carboxymethyloxysuccinic acid, the
various
alkali metal, ammonium and substituted ammonium salts of polyacetic acids such
as
ethylenediamine tetraacetic acid and nitrilotriacetic acid, as well as
polycarboxylates
such as mellitic acid, succiruc acid, oxydisuccinic acid, polymaleic acid,
benzene
1,3,5-tricarboxylic acid, carboxymethyloxysuccinic acid, and soluble salts
thereof.
Citrate builders, e.g., citric acid and soluble salts thereof (particularly
sodium salt),
are polycarboxylate builders of particular 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.
CA 02273325 2002-02-27
12
Also suitable in the detergent compositions of the present invention are the
3,3-dicar-
boxy-4-oxa-1,6-hexanedioates and the related compounds disclosed in U.S.
Patent
4,Sfi6,984, Bush, issued January 28, x986. Useful succinic acid builders
include the
CS-C20 alkyl and alkenyl succinic acids and salts thereof. A particularly
preferred
compound of this type is dc:>decenylsuccinic acid. Specific examples of
succinate
builders include: laurylsuccinate, myrisri~lsuccinate, palmitylsuccinate, 2-
dodecenylsuccinate (preferred), 2-pentadecenylsuccinate, arid the like.
Laurylsuccinates are the preferred builders of this group, and are described
in
European Patent Application 0,200,2f3, published November 5, 1986.
Other suitable polycarboxylates are disclosed in U. 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,"123,322.
Fatty acid, e.g., C12-Clg rnonocarboxylic 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 additianal 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 as ethane-1-
hydroxy-l,l-diphosphonate and other known phosphonates (see, for example, U.S.
Patents 3,159,581; 3,213,030; 3,422,021; 3,400,148 and 3,422,137) can also be
used.
Bleach
The detergent compositions herein may 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 from about 5% to about 20%, of the detergent
composition, especially for fabric laundering. If present, the amount of
bleach
activators will typically be from about 0.1 % to about 60%, more typically
from about
CA 02273325 2002-02-27
13
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 bleachng agent that can be used without restriction
encompasses percarboxylic acid bleaching agents 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 and diperoxydodecanedioic acid. Such bleaching agents
are
disclosed in U.S. Patent 4,483,781, Hartman, issued November 20, 1984, U.S.
Patent
No. 4,806,632, issued February 21, 19239, European Patent Application
0,133,354, Banks et al, published February 20, 1985, and U.S. Patent
4,412,934,
Chung et al, issued November 1, 1983. Highly preferred bleaching agents also
include 6-nonylamino-6-oxoperoxycaproic acid as described in U.S. Patent
4,634,SSl,~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 "percarbonate"
bleaches, sodium pyrophosphate peraxyh Td~rate, urea peroxyhydrate, and sodium
peroxide. Persulfate bleach (e.g., OXONE, manufactured commercially by DuPont)
can also be used.
A preferred percarbonate bleach comprises dry particles having an average
particle
size in the range from about 500 micrometers to about 1,000 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. Optionally, the percarbonate can be coated with silicate,
borate
or water-soluble surfactants. Percarbonate is available from various
commercial
sources such as FMC, Solvay and Tokai Denka.
Mixtures of bleaching agents can also be used.
CA 02273325 2002-02-27
14
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 April 10, 1990 to Mao et al, and U.S. Patent
4,412,934.
The nonanoyloxybenxene sulfonate (HOBS) 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:
R1N(RS)C(O)R2C(O)L or R1C(O)N(RS)RZC(O)L
wherein R1 is an alkyl group containing from about 6 to about 12 carbon atoms,
R2
is an alkylene containing from 1 to about 6 carbon atoms, RS is H or alkyl,
aryl, or
alkaryl containing from about 1 to about i0 carbon atoms, and L. is any
suitable
leaving group. A leaving group is any group that is displaced from the bleach
activator as a consequence of the nucleophilic attack on the bleach activator
by the
perhydrolysis anion. A preferred leaving group is phenyl sulfonate.
Preferred examples of bleach activators of the above formulae include (6-
octanamido-caproyl)oxybenzenesulfonate, (6-nonanamidocaproyl)oxybenzenesul-
fonate, (6-decanamido-caproyl)oxybenzenesulfonate, and mixtures thereof as
described in U.S. Patent 4,634,551.
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 benroxazin-type is:
O
II
C'O
of
~~C o
N
Still another class of preferred bleach activators includes the acyl lactam
activators,
especially acyl caprolactams and acyl valerolactams of the formulae:
0 O
O C-CH2--CH2 0 C-CH2-CHZ
R6 C NBC H --C H iC H2 R6-C-N.~C H - ( H
2 2 2 2
CA 02273325 2002-02-27
wherein R6 is I3 or an alkyl, aryl, alkoxyaryl, or alkaryl group containing
from 1 to
about 12 carbon atoms. I-Iighly 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 valerolactam,
nonanoyl
valerolactam, 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.
Bleaching agents other than oxygen bleaching agents are also known in the art
and
can 1>e utilized herein. One type of non-oxygen bleaching agent of particular
interest
includes photoactivated bleaching agents 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 corr~positions 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 ari and include, for example,
the
manganese-based catalysts disclosed in U.S. Pat. 5,246,621, U.S. Pat.
5,244,594;
U.S. Pat. 5,194,416; U.S. I'at. 5,114,606; and European Pat. App. Pub. Nos.
549,271A1, 549,272A1, 544,440A2, and 544,490A1; Preferred examples of these
catalysts include NinIV2(u-O)3(1,4,7-trimethyl-1,4,7-
triazacyclononane)2(PF6)2,
Mnr-02(u-O) 1 (u-OAc)2( 1,4,7-trimethyl-1,4,7-triazacyclononane)2-(C104)2,
~TV4(u-0)6(1,4,7-triazacyclononane)4{C104)4, Mn~MnIV4(u-O)1(u-OAc)2-
(1,4,7-trimethyl-1,4,7-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 ligands to enhance bleaching is also
reported in the following United States Patents: 4,728,455; 5,284,944;
5,246,612;
5,256,779; 5,280,117; 5,274,147; 5,153,161; 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 1 ppm
to
about 500 ppm, of the catalyst species in the laundry liquor.
CA 02273325 2002-02-27
16
Enrymes
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 Qrigin. However, their choice
is
govf;rned by several fac.tars such as pH-activity and/or stability optima,
thennostability, 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 sufficient to provide from 0.005 to 0.1 Anson units
(ALn 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
a strain of Bacillus, having maximum activity throughout the pH range of 8-12,
developed and sold by Nova Industries A/S under the registered trade mark
ESPERASE. The preparation of this enzyme and analogous enzymes is described in
British Patent Specification No. 1,243,784 of Novo. Proteolytic enzymes
suitable for
removing protein-based stains that are commercially available include those
sold
under the trademarks ALGALASE 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 9, 1985) and Protease B (see European Patent
Application 251,446, published January 7, 1988, and >r?uropean Patent
Application 130,756, Bott et al, published January 9, 1985).
CA 02273325 2002-02-27
17
Amylases include, for example, a-amylases described in British Patent
Specification
TM
No. 1,296,839 (Novo), RAPIDASE, International Bio-Synthetics, Inc. and
TM
TERMAMYL, 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 cellulase 212-producing fungus belonging to the genus
Aeromonas, and cellulase extracted from the hepatopancreas of a marine mollusk
(Dolabella Auricula Solander). suitable cellulases are also disclosedMin GB-A-
2.075.028; GB-A-2.095.275 and DE-OS-2.247.832. CAREZYIVjE (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 name Lipase P "Amano," hereinafter referred to as "Amano-P." Other
commercial lipases include Amano-CES, lipases ex Chromobacter viscosum, e.g.
Chromobacter viscosum var. lipolyticum NRRLB 3673, commercially available from
Toyo Jozo Co., Tagata, Japan; and further Chromobacter viscosum lipases from
U.S.
Biochemical Corp., U.S.A. and Disoynth Co., The Netherlands, and lipases ex
TM
Pseudomonas gladioli. The LIPOLASE enzyme derived from Humicola 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 sources, e.g.,
percarbonate,
perborate, persulfate, hydrogen peroxide, etc. They are used for "solution
bleaching," i.e. to prevent transfer of dyes or pigments removed fiom
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
CA 02273325 2002-02-27
18
WO 89/099813, published October 19, 1989, by O. Kirk, assigned to Novo
Industries A/S.
A wide range of enzynne materials and means for their incorporatian into
synthetic
detergent compositions are also disclosed in U.S. Patent 3,553,139, issued
January S,
19?1 to McCarty et al. Enzymes are further disclosed in U.S. Patent 4,101,457,
Place et al, issued July 18, 1978, and in U.S. Patent 4,507,219, Hughes,
issued March
26, 1985, both. Enryme 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. Enzymes 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 August 17, 1971 to Gedge, 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 antiredeposition agents, dispersing agents,
brighteners, suds suppressors, fabric safleners, dye transfer inhibition
agents and
perfumes.
CA 02273325 1999-OS-20
WO 98/24875 PCT/US97/21044
19
EXAMPLES
Ex. 1 Ex. 2
Anionic Agglomerates 26.69 20.91
Nonionic Agglomerate 5.72 4.61
Bleach Activator Agglomerates5.89 4.75
Zinc Phthalocyanine sulphonate0.03 0.02
encapsulate
Suds Supressor 3.34 2.69
Dried Zeolite 6.52 5.26
Layered Silicate 14.17 11.43
Dye transfer Inhibitor Agglomerate0.13 0.10
Perfume Encapsulates 0.23 0.19
Nonionic Paste Spray-on 5.62 4.53
Fluorescer 0.27 0.22
Sodium carbonate 4.84 3.94
Sodium percarbonate 20.52 16.54
Sodium HEDP 0.82 0.66
Soil Release polymer 0.18 0.15
Perfume 0.34 0.27
Protease 0.89 0.72
Cellulase 0.26 0.21
Lipase 0.22 0.18
Amylase 0.72 0.58
Lauric Acid 2.6 2.60
Effervescency Compact - 19.48
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.
CA 02273325 2002-02-27
Z0
Bleach activator agglomerates comprise 81% TAED, 17% acrylic/maleic copolymer
(acid form) and 2% water.
Zinc Phthalocyanine 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.
Dye transfer inhibitor agglomerates comprise 21°~o PVNO/PVPVI, 61%
zeolite and
18% carbonate.
Perfume encapsulates comprise 50% perfume and 50% starch.
Nonionic paste spray-on comprises 67% C,z-C,s AES (alcohol with an average of
S
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 em, and
compressed with a force of 0.5 lcN. or about 30 Newton/cm2, to give tablets of
about
2.2 cm height and a density of about 1.1 g./cc. 'Che tensile strength of the
tablet was
3.5 kPa.
Lauric acid was heated in a thermostatic bath to 60 °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 38.5 g, and a tensile strength of 10.1 kPa.
CA 02273325 1999-OS-20
WO 98/24875 PCT/US97/21044
21
A second series of tablets was made with a compaction force of lkN, 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 Lauric Acid the tablets had a weight of 38.5 g, and the
tensile
strength was 21 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 kPa.
After coating with Lauric Acid the tablets had a weight of 38.5 g, and the
tensile
strength was 23.4 kPa.
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
g./cc, and
a tensile strength of 4. 5 kPa.
After coating with Lauric acid the tablets had a weight of 38.5 g, and the
tensile
strength was 13.1 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 Lauric Acid the tablets had a weight of 38.5 g, and a
tensile
strength was 15.8 kPa.
CA 02273325 1999-OS-20
WO 98/24875 PCT/I1S97/21044
22
A 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 Lauric Acid the tablets had a weight of 38.5 g, and the
tensile
strength increased to 24.1 kPa.
Example 1 was repeated replacing the Lauric acid by hexadecanol. The
hexadecanol
was heated in a thermostatic bath to 80°C with gentle stirring until
molten. The final
tensile strength of the three series of tablets was 14.1 kPa, 21 lcPa and 23.4
lcPa
respectively.
Example 2 was repeated replacing the Lauric acid by hexadecanol. The
hexadecanol
was heated in a thermostatic bath to 80°C with gentle stirring until
molten. The final
tensile strength of the three series of tablets was 12.1 kPa, 13.6 kPa and
22.1 kPa
respectively.
