Background of the Invention
[0001] This invention is directed to clear or transluscent liquid detergents that are unbuilt
or built with water-soluble builders. Such detergents generally comprise l to 60%
surfactants; up to 5% foam control agents; up to l0% water-soluble detergent builders;
0.l to 3% of an active agent which can provide anti-redeposition, viscosity-modifying,
and improved cleaning performance functions; and remainder to l00% of water and other
ingredients. In a preferred embodiment, the active agent is a water-soluble or water-dispersible
polymer, an alpha-beta ethylenically unsaturated lightly crosslinked lower aliphatic
carboxylic acid having molecular weight in the range of about one-half million to
5 million, measured at room temperature. Such detergents are particularly effective
on cotton and cotton/polyester fabrics.
[0002] As already noted, the active agent that is used in liquid laundry detergent compositions
disclosed herein can provide the functions of soil anti-redeposition, viscosity modification,
and improved cleaning performance. This agent has been used in detergent compositions
in the past and is identified in the prior art as neutralized crosslinked polyacrylate
polymer, as modified polyacrylic thickening agent, and as sodium polyacrylate. The
prior art discloses the use of the active agent at a level of about 0.l to 2% by weight
of total composition.
[0003] British patent 2,079,305 describes built liquid enzymatic detergents containing,
inter alia, an enzyme, a polyol, boric acid, and a neutralized crosslinked polyacrylate
polymer. The polyacrylate polymer is described as being water-soluble polymer of acrylic
acid crosslinked with not more than l0% of a cross-linking agent containing a vinyl
group. Specific examples of the polyacrylate polymer noted in this patent include
Carbopol ® 934, 940 and 94l, products of The B.F.Goodrich Company, assignee of the
invention claimed herein. Amount of the polyacrylate polymer is disclosed as 0.l to
2% by weight of the total detergent composition. The use of a polyol, boric acid,
and a polyacrylate polymer in liquid enzymatic detergents results in stable aqueous,
built enzymatic liquid detergents which have satisfactory enzyme stability, especially
at higher pH, as well as storage stability.
[0004] The unbuilt liquid laundry detergents disclosed herein are patentable over the British
patent since the patent does not teach nor suggest the use of a polyacrylate polymer
in conjunction with unbuilt liquid enzymatic detergents. This is based on disclosure
in lines 2l-26 of the patent where it is stated that the use of a polyol and boric
acid in certain ratio has been suggested in the prior art. Although this patent does
teach the use of a polyacrylate polymer in built liquid detergents in conjunction
with a polyol and boric acid, this patent discloses at middle of column 2, on page
2 that all kinds of builders can also be used. Although any builder appears suitable
for use in the liquid enzyme detergents disclosed by the British patents, only water-soluble
builders are suitable in the liquid laundry detergents described herein. It is also
important to note that this patent discloses at bottom of column 2, on page 2 that
other conventional materials can also be present in the liquid enzymatic detergents.
Many different conventional materials are listed, including soil suspending agents.
Polyacrylate polymers were not known as soil-suspending agents at time of the filing
of the patent application which matured into the British patent. The prior art, at
that time, recognized the use of carboxymethyl cellulose and other materials disclosed
at top of column l0 of U.S. patent 4,092,273, as known soil suspending agents. Carboxymethyl
cellulose is effective on cotton but ineffective on cotton/polyester blends. It is
believed that the use of polyacrylate polymers, and other suitable polymers disclosed
herein, as soil suspending agents was discovered by applicants and is disclosed for
the first time. Therefore, the use of polyacrylate polymers, and other cognate materials
disclosed herein, as suspending agents, would eliminate the use of the conventional
soil suspending agents. Furthermore, the invention disclosed herein does not rely
on the interaction of a polyol, boric acid and a polyacrylate to obtain a liquid detergent
having satisfactory enzyme stability as well as satisfactory physical storage stability.
[0005] U.S. patent 4,l47,650 describes slurry detergents comprising alkali metal hydroxides
and/or silicates, condensed phsophates, sodium hypochlorite, and sodium polyacrylate.
This patent asserts that slurry detergents are more advantageous than granular or
liquid detergents since the granular detergents are subject to caking and the liquid
detergents are limited in their strength by the solubility of its ingredients. This
patent also asserts that the disclosed slurry detergent makes it possible to use more
complex phosphates and alkaline ingredients since a slurry does not require a true
solution. A slurry, as described by this patent, is a mass of semi-fluid ingredients
of relatively homogenous nature. Sodium polyacrylate acts synergistically with sodium
tripolyphosphate to form a homogeneous suspension in slurry form, thus facilitating
uniform and complete dispersion. As long as no more than 30% of sodium tripolyphosphate
and 5% of sodium tripolyphosphate is used, a satisfactory slurry is formed. If more
is used, the mass becomes too viscous or may solidify. Minimum amount of tripolyphosphate
is 5% and that for polyacrylate is l%, on dry weight basis. Generally, amount of the
polyacrylate in the detergent composition can be in the range of l to l0% by weight,
on anhydrous basis.
[0006] The liquid detergent compositions disclosed herein are patentable over U.S.Patent
4,l47,650 because the ingredients thereof are wholly soluble therein and the liquid
detergent compositions are, for that reason, clear or transluscent, in absence of
pigment. As is apparent from the above discussion, the ingredients in the slurry detergent
compositions are not wholly soluble therein by definition, and thereby, are not clear
or transluscent. Furthermore, although sodium tripolyphosphate can be present in liquid
detergents described herein, it can be present up to its solubility limit of about
l0% in water. Therefore, since sodium tripolyphosphate can be absent from the liquid
detergents disclosed herein, the synergism between it and sodium polyacrylate, relied
on by USP 4,l47,650, would also be absent, indicating a different kind of detergent.
[0007] U.S. Patent 4,2l5,004 is also directed to slurry detergent compositions. These detergents
are heavy duty, built detergents containing an alkali metal hydroxide, detergents,
sodium polyacrylate, a modified polyacrylic acid, and water insoluble aluminosilicate
ion exchange material and/or complex phosphates, as well as other conventional additives.
[0008] The liquid detergent compositions disclosed herein are patentable over U.S. Patent
4,2l5,004 for the same reasons presented in connection with U.S. Patent 4,l47,650.
Principally, the basic distinction is that inherent in a liquid detergent as compared
to a slurry detergent.
[0009] U.S. Patents 4,092,273 and 4,368,l47 relate to liquid detergents and both emanate
from the same parent application. The detergents disclosed in these patents have viscosity
of 40 to l20 cps at 24°C, contain nonionic surfactants, an alkanol, a viscosity prevention
agent, and water. In one patent, the viscosity control agent is a water soluble salt
of a dicarboxylic acid whereas in the other patent, the viscosity control agent is
sodium or potassium formate in conjunction with the alkanol. These two patents are
noted only as being illustrative of liquid detergent compositions.
Summary of the Invention
[0010] Liquid detergents are disclosed herein which are clear or transluscent and are characterized
by the presence of water-soluble sequester builders and an active ingredient which
provides anti-redeposition, viscosity-modifying, and improved cleaning performance
functions. The active ingredient is preferably a polymer of acrylic acid having molecular
weight of about one-half million to five million, which is used at a level of 0.05
to 5%, based on the weight of the liquid detergent composition.
Detailed Description of the Invention
[0011] This invention is directed to clear or transluscent liquid detergents. This property
of these detergents is due to the fact that all of the ingredients are water-soluble
and are completely solubilized. Their pH is generally in the range of about 6 to l2,
preferably 8-l0. Most preferably, detergents have a nearly neutral pH. Such detergents
have viscosity of 40 to 200 cps at 24°C and are readily pourable at room temperature.
This class of detergents includes unbuilt and built liquid detergents containing water-soluble
sequester builders such as citrates, soap, linear polyacrylates, and the like. Sodium
carbonate, for instance, is not a sequestrant builder. Amount of surfactants in these
detergents can vary from l to 60%, preferably l0 to 40%; up to 20% and preferably
up to l0% of water-soluble sequester builders; 0.05 to 5%, preferably 0.l to 2%, of
an active agent which can provide anti-redeposition, viscosity-modifying, and improved
cleaning performance functions; and water and other conventional additives to make
up l00% by weight of a liquid detergent composition.
[0012] The liquid detergents described herein differ in character from the slurry detergents
known in the prior art. A slurry detergent is a mass of semi-fluid ingredients of
relatively homogeneous nature that is not a true solution. Since a slurry is not a
true solution, slurry detergents allow the use of more complex phosphates and alkaline
ingredients since these ingredients need not be completely solubilized. Where used,
a polyacrylate acts synergistically with tripolyphosphate to suspend the other ingredients
in a slurry detergent which are not completely solubilized.
[0013] The active agent noted herein when used in a liquid detergent provides significant
advantages over prior art liquid detergents which are devoid of such active agents.
When used at recommended level in liquid detergents, the active agents provide soil
anti-redeposition function and improved cleaning performance, as verified on cotton
and cotton/polyester blend fabrics. This is surprising since carboxymethyl cellulose,
a known anti-redeposition agent for cotton, is ineffective on cotton/polyester blended
fabrics although it is known to be effective on cotton. Additionally, such active
agents impart viscosity control character in that liquid detergents formulated therewith
have a nearly constant viscosity within an acceptable pourable range of about 40-200
cps irrespective of widely differing levels of anionic and/or nonionic surfactants.
Viscosity of such liquid detergents can be maintained in the pourable range when varying
amounts and relative ratios of anionic and nonionic surfactants between about l0 and
35%, based on the weight of the total liquid detergent. When mixtures of surfactants
are used, such as anionic and nonionic surfactants, relative ratio thereof can vary
from l0/l to l/l0, preferably 6/l to l/6.
[0014] The water-soluble sequestrant builders suitable herein can be used in amounts varying
up to 20%, preferably up to l0% by weight of the total liquid detergent composition.
The amounts of the builders given herein are subject to the condition that they be
completely soluble in the composition. The water-soluble sequestrant builders are
those which reduce the free calcium magnesium ion concentration in the wash system
down to the desired levels (usually less than about 5 ppm as calcium carbonate) via
formation of soluble complexes with calcium and magnesium ions. Examples of such builders
include alkali metal and particularly sodium citrate, alkali metal and particularly
sodium laurate, alkali metal silicates, linear polyacrylates, tetrapotassium, pyrophosphate,
etc. Other builders that are not soluble to the extent used or which are not also
sequestrants can be used but only to the limit of their solubility in the liquid detergent
composition. For instance, sodium tripolyphosphate is soluble in water up to about
l0% whereas tetrapotassium pyrophosphate is soluble in water up to about 25%. Therefore,
in conformity with the spirit of this invention, such builders can be used but only
to the extent of their solubility in the liquid detergent composition. In a preferred
embodiment, however, suitable builders are selected from water-soluble sequestrant
builders described above.
[0015] Suitable surfactants are selected from anionic, nonionic, cationic, zwitterionic
or amphoteric materials. Surfactants are used at a level of 5 to 50%, preferably l0
to 40%, based on the weight of the liquid detergent composition. Mixtures of surfactants
can be used, particularly mixtures of anionic and nonionic surfactants.
[0016] Examples of suitable anionic synthetic surfactants are salts of C₈ to C₂₀ alkylbenzene
sulfonates, C₈ to C₂₂ primary or secondary alkane sulfonates, C₈ to C₂₄ olefin sulfonates,
sulfonated polycarboxylic acids prepared by sulfonation of pyrolyzed product of alkaline
earth metal citrates, C₈ to C₂₂ alkyl sulfonates, C₈ to C₂₄ alkylpolyglycolether sulfonates
containing up to l0 mols of ethylene oxide, and the like. Suitable salts herein refer
particularly to sodium, potassium, ammonium, and substituted ammonium salts such as
mono-, di-, and triethanolamine salts. Other examples of suitable anionic surfactants
are described in "Surface Active Agents and Detergents" (vol. I and II) by Schwatz,
Perry and Berch.
[0017] Examples of nonionic synthetic detergents are condensation products of ethylene oxide,
propylene oxide and/or butyleneoxide with C₈-C₁₈ alkylphenols, C₈-C₁₈ primary or secondary
aliphatic alcohols, C₈-C₁₈ fatty acid amides. Other examples of nonionics include
tertiary amine oxides with one C₈-Cl8 alkyl chain and two C
l-3 alkyl chains. The above reference also describes further examples of nonionics.
[0018] The average number of moles of ethylene oxide and/or propylene oxide present in the
above nonionics varies from l-30; mixtures of various nonionics, including mixtures
of nonionics with a lower and a higher degree of alkoxylation, may also be used.
[0019] Examples of cationic detergents are the quaternary ammonium compounds such as alkyldimethylammonium
halogenides, but such cationics are less preferred for inclusion in enzymatic detergent
compositions since their use may lead to incompatibility.
[0020] Examples of amphoteric of zwitterionic detergents are N-alkylamino acids, sulphobetaines,
condensation products of fatty acids with protein hydrolysates, but owing to their
relatively high costs, they are usually used in combination with anionic of a nonionic
detergent.
[0021] Mixtures of the various types of active detergents may also be used, and preference
is given to mixtures of an anionic and a nonionic surfactants. Soaps, in the form
of their sodium, potassium, and substituted ammonium salts such as of polymerized
fatty acids, may also be used, preferably in conjunction with an anionic and/or a
nonionic synthetic detergent.
[0022] The active ingredient, referred to above, has shown to be particularly effective
on cotton and cotton/polyester blended fabrics in terms of soil anti-redeposition
and improved cleaning performance. Additionally, the active ingredient is effective
as a viscosity control agent in maintaining viscosity of the liquid detergent compositions
essentially constant in the pourable range of 40 to 200 cps, measured at 24°C. For
clear liquid detergents based on nonionic surfactants alone, 0.l% of the active ingredient
yields both viscosity control and antiredeposition as well as improved cleaning performance.
However, for liquid detergents based on anionic surfactants alone, 0.5% of the active
ingredient is needed to achieve both viscosity control and antiredeposition as well
as improved cleaning performance.
[0023] The active agents suitable herein are selected from synthetic agents. The synthetic
agents contemplated herein include commercially available polymeric agents, such as
Carbopol® agents, available from The BFGoodrich Company, and other polymeric agents
sold under tradenames such as Acrisint® , Junlon® , Rheogic® , Acrysol® , Alcoprint®
, EMA® , Gaftex® , and Polycarbophil® polymeric materials. Particular agents in this
group found suitable herein include Carbopol 6l5, 676, 940, 94l and l342 resins, which
are available from The BFGoodrich Company; Acrisint 3l0 agent, available from Sigma
Chemical Company; Junlon PW-l50 and remainder of this series, available from Showa
Tsusho Company of Japan; Rheogic series, available from Showa Tsusho Company of Japan;
Hiviswako l03 and the rest of that series, available from Wako Pure Chemical Industries
of Japan; Acrysol ICS-l and related agents, available from Rohm & Haas; Alcoprint
PTF and the related agents, available from Allied Colloids of Great Britain; EMA-9l
and related agents, available from Monsanto Company; and Gaftex PT and similar agents,
available from GAF Corporation.
[0024] Synthetic agents are generally selected from carboxyl containing polymers and polyamides.
Preferred agents are selected from homopolymers of an acrylic acid, homopolymers of
alkyl acrylates, and copolymers of an acrylic acid or an acrylic ester with suitable
comonomers or with each other. Such agents can be non-crosslinked or lightly crosslinked
and can be functionally identified as water-soluble or water-swellable. The lightly
crosslinked materials herein are crosslinked with up to about l0% by weight of a suitable
crosslinking agent, preferably up to 5%, and especially 0.0l to 2%. The non-crosslinked
synthetic agents are generally soluble in water whereas the lightly crosslinked agents
are generally swellable in water although there are some exceptions to these generalizations.
In one instance, one such agent is water-swellable although it is not crosslinked.
At times, it is difficult to differentiate between water-soluble and water-swellable
agents since some are water-soluble and water dispersible.
[0025] More particularly, the principal class of synthetic agents suitable herein are the
polyacrylic acids which can be homopolymers of an alpha, beta-olefinically unsaturated
monocarboxylic acid of 3 to 5 carbon atoms and copolymers thereof with one or more
suitable comonomers. The acrylic acid copolymers are selected from copolymers of one
or more monounsaturated monocarboxylic acid of 3 to 5 carbon atoms copolymerized with
up to about 20% by weight, preferably up to about l0% by weight, of one or more other
copolymerizable monomers. Preferred acrylic acids for use in this invention have the
following general structure:
CH₂=
-COOH
wherein R is a substituent selected from the class consisting of hydrogen, halogen,
and the cyano (-C=N) groups, monovalent alkyl radicals, monovalent aryl radicals,
monovalent aralkyl radicals, monovalent alkaryl radicals, and monovalent cycloaliphatic
radicals. Of this class, acrylic and methacrylic acids are most preferred because
of generally lower cost, ready availability and ability to form superior polymers.
[0026] Suitable comonomers are selected from alkyl acrylates represented by the following
formula
CH₂=
-O-R
where R' is hydrogen, methyl, or ethyl group; and R is an alkyl group of l0 to 30,
preferably l0 to 20 carbon atoms; R can also be selected from alkyl, alkoxy, haloalkyl,
cyanoalkyl, and the like groups, containing l to 9 carbon atoms. Representative acrylates
include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate,
methyl ethacrylate, octyl acrylate, octyl methacrylate, 2-ethylhexyl acrylate, n-hexyl
methacrylate, isodecyl methacrylate, lauryl acrylate, stearyl acrylate, behenyl acrylate,
melissyl acrylate and the corresponding methacrylates. Mixtures of two or three or
more of the acrylic esters may be successfully polymerized with one of the carboxylic
acid monomers. One useful class of copolymers are those methacrylates where the alkyl
group contains l0 to 20 carbon atoms. Typical polymers have been made with about l5
weight percent isodecyl methacrylate, about l0 weight percent lauryl methacrylate,
and about 7 weight percent stearyl methacrylate, with acrylic acid.
[0027] Other vinylidene comonomers may also be used, particularly in conjunction with acrylic
esters, including the acrylic nitriles, -olefinically unsaturated nitriles useful
in the interpolymers embodied herein, preferably the monoolefinically unsaturated
nitriles having from 3 to l0 carbon atoms such as acrylonitrile, methacrylonitrile,
and the like. Most preferred are acrylonitrile and methacrylonitrile. The amounts
used, for example, for some polymers are from about 5 to 30 weight percent of the
total monomers copolymerized.
[0028] Acrylic amides include monoolefinically unsaturated amides that may be incorporated
in the interpolymers of this invention having at least one hydrogen on the amide nitrogen
and the olefinic unsaturation is alpha-beta to the carbonyl group. Very much preferred
are acrylamide and methacrylamide used in amounts, for example, from about l to 30
weight percent of the total monomers copolymerized. Other acrylic amides include N-alkylol
amides of alpha, beta-olefinically unsaturated carboxylic acids including those having
from 4 to l0 carbon atoms. The preferred monomers of the N-alkylol amide type are
the N-alkylol amides of alpha,
beta-monoolefinically unsaturated monocarboxylic acids and the most preferred are
N-methylol acrylamide and N-methylol methacrylamide used in amounts, for example,
of about l to 20 weight percent. N-alkoxymethyl acrylamides also may be used. The
preferred alkoxymethyl acrylamides are those wherein the alkyl group contains from
2 to 5 carbon atoms and useful is N-butoxymethyl acrylamide.
[0029] Other vinylidene comonomers generally include, in addition to those described above,
at least one other olefinically unsaturated monomer, more preferably at least one
other vinylidene monomer (i.e., a monomer containing at least one terminal CH₂=C <
group per molecule) copolymerized therewith, for example up to about 30% or more by
weight of the total monomers. Suitable monomers include α-olefins containing from
2 to l2 carbon atoms, such as ethylene and propylene; dienes containing from 4 to
l0 carbon atoms, including butadiene; vinyl esters and allyl esters such as vinyl
acetate; vinyl aromatics such as styrene; vinyl and allyl ethers and ketones such
as vinyl methyl ether and methyl vinyl ketone; cyanoalkyl acrylates such as α-cyanoalkyl
acrylates, the α-, β- and -cyanopropyl acrylates, vinyl halides and vinyl chloride,
vinylidene chloride and the like; esters of maleic and fumaric acid and the like.
[0030] The polyacrylic acids described herein can be crosslinked with a suitable polyfunctional
vinylidene monomer containing at least two terminal CH₂=C< groups, including for example,
butadiene, isoprene, divinyl benzene, divinyl naphthalene, allyl acrylates and the
like. Particularly useful cross-linking monomers for use in preparing the copolymers,
if one is employed, are polyalkenyl polyethers having more than one alkenyl ether
grouping per molecule. The most useful possess alkenyl groups in which an olefinic
double bond is present attached to a terminal methylene groups, CH₂=C< . They are
made by the etherification of a polyhydric alcohol containing at least 4 carbon atoms
and at least 3 hydroxyl groups. The product is a complex mixture of polyethers with
varying numbers of ether groups. Analysis reveals the average number of ether groupings
on each molecule. Efficiency of the polyether cross-linking agent increases with the
number of potentially polymerizable groups on the molecule. It is preferred to utilize
polyethers containing an average of two or more alkenyl ether groupings per molecule.
Other cross-linking monomers include, for example, diallyl esters, dimethallyl ethers,
allyl or methallyl acrylates and acrylamides, tetraallyl tin, tetravinyl silane, polyalkenyl
methanes, diacrylates, and dimethacrylates, divinyl compounds as divinyl benzene,
polyallyl phosphate, diallyloxy compounds and phosphite esters and the like. Typical
agents are allyl pentaerythritol, allyl sucrose, trimethylolpropane triacrylate, l,6-hexanediol
diacrylate, trimethylolpropane diallyl ether, pentaerythritol triacrylate, tetramethylene
dimethacrylate, tetramethylene diacrylate, ethylene diacrylate, ethylene dimethacrylate,
triethylene glycol dimethacrylate, and the like. Allyl pentaerythritol, allyl sucrose
and trimethylolpropane diallyl ether provide excellent polymers in amounts less than
5, as less than 3 weight percent, and particularly about 0.l to 2.0% by weight of
all monomers.
[0031] For purposes of clarification, it is pointed out that, generally speaking, the lightly
crosslinked synthetic thickeners described herein swell in water whereas the non-crosslinked
thickeners are soluble in water. Both types, however, are suitable in the invention
herein.
[0032] The preferred polyacrylic acid homopolymers and copolymers useful herein, as described,
include crosslinked and non-crosslinked polymers prepared in an organic solvent, especially
benzene, with molecular weights in the range of about l00,000 to l0,000,000. Especially
preferred are lightly crosslinked polyacrylic acid homopolymers of acrylic acid itself
in the molecular weight range of about 200,000 to 5,000,000. The polyacrylic agents
are in acid form which are neutralized to a salt form for use in the invention described
herein.
[0033] Other suitable polycarboxylic resins are lightly crosslinked, swellable resin polymers
containing a carboxylic acid as a major component. These materials are polymerized
in an aqueous solution of a soluble nonredox divalent inorganic ion, such as magnesium
sulfate. The salt is normally used at a level of above about one-half molar. The major
component can be homopolymerized or copolymerized with a suitable comonomer. Suitable
carboxylic acids include monounsaturated monocarboxylic and dicarboxylic acids containing
3 to 5 carbon atoms, salts thereof and anhydrides thereof. Specific examples thereof
include acrylic acid and salts thereof, methacrylic acid and salts thereof, fumaric
acid, maleic acid and its anhydride, itaconic acid, and the like. Acrylic acid is
preferred. Polyunsaturated copolymerizable crosslinking agents, which form a minor
component of these resins, have two or more double bonds subject to crosslinking with
the monomers and can be aromatic or aliphatic. As disclosed in Example l of U.S. Patent
2,8l0,7l6, such resins can be obtained by preparing a mixture of l00 grams of acrylic
acid, l.2g of divinyl benzene, and l.0g of benzoylperoxide. This mixture is added
to an aqueous saturated magnesium sulfate solution and heated to 95°C. After l6 minutes,
l00.5g of the resin is obtained, which is highly swelling. Such resins are well known
in the art.
[0034] Other conventional materials may also be present in the liquid detergent compositions
of the invention, for example hydrotropes, corrosion inhibitors, dyes, perfumes, silicates,
optical brighteners, suds boosters, suds depressants such as silicones, germicides,
anti-tarnishing agents, pacifiers, fabric softening agents, oxygen-liberating bleaches
such as hydrogen peroxide, sodium perborate or percarbonate, diperisophthalic anhydride
with or without bleach precursors, reducing bleaches such as sodium sulphite, buffers
and the like.
[0035] The liquid laundry detergents are presently known. The labels of the major U.S. and
West European liquid laundry detergents indicate that such detergents are either unbuilt
or built with water-soluble, weak detergent builders such as sodium citrate, sodium
laurate, and the like. These detergents are also clear or translucent, have approximately
a neutral pH, and have a pourable viscosity of 40 to 200 cps. Their formulations are
generally as follows:
[0036] The above formulations cover built and unbuilt detergents since the level of builders
varies from 0 to l0%. An unbuilt detergent, of course, contains no detergent builder
whereas a built detergent contains an amount of up to l0% by weight of a water-soluble
detergent builder.
[0037] The above formulations are devoid of the active agent described herein. When liquid
detergents are prepared pursuant to the invention disclosed herein, amount of a viscosity
control agent will vary from about 0.05 to 5%, and preferably 0.l to 2%, by weight.
It should be apparent that the liquid laundry detergent prepared as described herein
will not only contain less than one-half of a different viscosity control agent, but
the detergents will be more versatile and more effective not only on cotton but also
on blends of cotton and polyester. The effectiveness referred to herein pertains to
anti-redeposition, improved cleaning performance, and to viscosity control.
[0038] The examples that follow demonstrate the invention described herein in terms of liquid
laundry detergents and their effectiveness to maintain viscosity control and in anti-redeposition
and improved cleaning.
[0039] For the examples that follow, a number of different active agents were used to demonstrate
the asserted advantages. The active agents that were tested were Carbopol® materials
94l and l342, both of which are available from The BFGoodrich Company. Molecular weight
and aqueous solutions of these active agents are defined as follows:
Example l
[0040] This example demonstrates the function of certain active agents in anionic and nonionic
surfactants. Two typical anionic and three typical nonionic surfactants were tested.
The following anionic surfactants were tested:
(a) straight chain dodecylbenzene sodium sulfate, commercially available as Conoco
C-550 from Conoco Chemicals, a division of Conoco, Inc.; and
(b) sodium alpha olefin sulfonate, commercially available as Conco AOS-40 from Continental
Chemical Company.
[0041] The following nonionic surfactants were tested:
(l) modified oxyethylated straight chain alcohol with an HLB value of l0.0, commercially
available as Plurafac RA-20 from BASF Wyandotte Corporation;
(2) Cl2-l5 linear primary alcohol ethoxylated with an HLB value of l2.0, commercially available
as Neodol 25-7 from Shell Chemical Company; and
(3) nonylphenoxy polyethoxy ethanol with an HLB value of l2.2, commercially available
as Surfonic N-95 from Jefferson Chemical Company.
[0042] Although Plurafac RA-20 and Neodol 25-7 nonionic surfactants are structurally similar,
they vary widely in their viscosity behavior, due probably to a slight variation in
alkyl chain distribution and/or number of ethylene oxide units.
[0043] Experimental liquid detergent samples were prepared by following procedure:
Step l: prepare l.0% of the Carbopol resin stock mucilages and adjust them to pH of 8.0;
Step 2: mix appropriate quantities of the stock mucilages and specified surfactants (adjusted
to pH of 8.0) to give the desired product compositions;
Step 3: readjust pH of the resulting liquid detergent product to pH of 8.0 + 0.5, employing
l0% sodium hydroxide. Apparent viscosities of such samples were determined employing
a Brabender Rheotron Bob and Cup rotational viscometer at 30°C and at a shear rate
of l44/sec. The active agent was preneutralized to pH of 8.0 before it was mixed with
a surfactant. The surfactant was also preneutralized to pH of 8.0. Results in terms
of viscosity (cps) for the five surfactants and the two active agents are given in
Table I, below:
[0044] The above data demonstrates several important factors. The active agents at levels
of 0.l to 0.5% in the experimental liquid detergents exhibited a very striking viscosity
moderating effect by maintaining viscosity of the detergents very nearly constant
and within the pourable range, even when the surfactant level was varied widely between
l0 and 35%. This is self-evident for the data for nonionic surfactant Plurafac RA-20,
anionic surfactant Conoco C-550, and anionic surfactant Conco AOS-40.
[0045] This viscosity moderating role of the active agent is expected to provide formulating
cost benefit and flexibility in the compounding of commercial liquid detergent compositions.
[0046] The viscosity moderating effect of the active agents described herein is unexpected
in view of the corresponding agents used presently, such as ethanol, propanol, sodium
formate, potassium formate, sodium adipate, and the like, which specifically uniformly
decrease viscosity at every surfactant concentration. Other viscosity moderating agents
presently used have the opposite effect, i.e., increase viscosity uniformly at every
surfactant concentration and act as plain thickeners. Examples of agents in this group
include glycerin, propylene glycol, or any polyol. Therefore, neither of these groups
of agents provides a near constant viscosity irrespective of surfactant concentration
over a wide latitude.
[0047] With certain commercial active agents, the viscosity control was not achieved. This
applies to the nonionic surfactants Neodol 25-7 and Surfonic N-95 materials. With
these surfactants, the active agents behaved more like conventional thickening agents
rather than as viscosity moderators. In these instances, the addition of 0.l% of an
active agent, increased viscosity uniformly at each surfactant concentration.
[0048] This experiment demonstrates another feature of the invention. Whereas conventional
viscosity moderating agents are used at levels of 2 to l0%, the herein-disclosed active
agents are used at only about 0.l% level. The difference is very substantial, even
if only considered on the weight basis. Furthermore, whereas the herein-disclosed
active agents also provide anti-redeposition and improved cleaning performance, the
conventional viscosity moderating agents do not.
Example 2
[0049] This example demonstrates cleaning performance or detergency and anti soil redeposition
function of certain active agents in liquid detergent compositions. The detergency
test used was ASTMD 3050-75, which is a standard method for measuring soil removal
from artificially soiled fabrics. The anti soil redeposition test used was ASTM D4008-8l,
which is a standard method for measuring anti soil deposition properties of laundry
detergents. Standard cotton and cotton/polyester fabrics were used. Whereas the tests
prescribe 0.l5% of a detergent composition, 0.3% was used in each test. Otherwise,
conditions and materials prescribed by the tests were used. Results obtained with
various compositions and on the particular fabrics are given in Table II, below:
[0050] The detergency tests were carried out to measure cleaning performance of the various
liquid detergents. These tests were very similar to the whiteness retention tests
which gave a measure of soil redeposition function. Whereas one wash cycle was used
in the detergency test, ten wash cycles were used in the whiteness retention test.
[0051] In the discussion of the test results that follows, significant variation for the
detergency tests is ±0.5% whereas significant variation for the whiteness retention
tests is ±0.2%.
[0052] Series l samples of Table II consisted of the nonionic surfactant Neodol 25-7 in
water at different concentrations. At 20% of the surfactant in water, detergency on
cotton was 46.3% with no active agent and increased to 49.l% when 0.l% of Carbopol
94l active agent was added. It should be apparent to one skilled in the art that there
is a difference of 2.8%, which s a very large and significant difference. At 25% of
the surfactant, the corresponding difference was even greater at 3.6%. Another test
was conducted at 20% surfactant with similar results.
[0053] The whiteness retention tests also yielded superior results. At 20% surfactant on
cotton, whiteness retention was 9l.5% with no active agent which increased to 92.3%
when 0.l% of Carbopol 94l active agent was added. A difference here of 0.8% is very
important and represents an important improvement. The whiteness retention, in this
particular example, remained the same for the cotton/polyester blend.
[0054] At 25% surfactant, the whiteness retention was even more pronounced than at 20% surfactant
concentration. On cotton, an improvement of l.l% was measured whereas on cotton/polyester
blend, an improvement of 2.7% was obtained. These results are incredible, especially
when considered in the context that only 0.l% of the active agent was used.
[0055] In Series 2 samples, active agent Carbopol 94l was added to detergent "Wisk" at various
levels and whiteness retention on cotton was measured. A very significant difference
of 0.5% improvement in whiteness retention was measured when 0.5% of the active agent
was added to the "Wisk" detergent. This difference improved further when more active
agent was added.
[0056] In Series 3 and 4 samples, two other anionic active agents were tested on cotton
fabric and cotton/polyester blends and showed very advantageous results when active
agents described herein were incorporated.
1. A liquid detergent composition that is clear or transluscent, pourable at room
temperature, and provides soil anti-redeposition function and improved cleaning performance
comprising l to 60% by weight of total composition of at least one surfactant, up
to 20% by weight of total composition of at least one water-soluble sequester builder,
and a sufficient amount of an active agent to impart soil anti-redeposition function
and improved cleaning performance to said composition, said active agent is selected
from the group consisting of homopolymers of monounsaturated monocarboxylic and dicarboxylic
acids of 3 to 5 carbon atoms and salts thereof, copolymers thereof with up to 20%
by weight of one or more copolymerizable monomers, and mixtures of such homopolymers
and copolymers.
2. Composition of claim l wherein said active agent is present in amount of 0.05 to
5% and it is water-soluble.
3. Composition of claim 2 wherein amount of said surfactant is l0 to 40% and amount
of said builder is 0 to l0%, said composition being pourable at room temperature.
4. Composition of claim 3 wherein said builder is selected from the group consisting
of sequestrant builders.
5. Composition of claim 3 wherein said builder is selected from citrates, soap, linear
polyacrylates, and mixtures thereof.
6. Composition of claim 3 wherein said builder is selected from the group consisting
of sodium laurate, sodium citrate, sodium nitrilotriacetate, tetrapotassium pyrophosphate,
sodium tripolyphosphate and mixtures thereof.
7. Composition of claim 3 wherein said active agent is selected from homopolymers
of an acrylic acid defined as follows:
CH₂=
-COOH
where R is selected from hydrogen, halogen, cyano, alkyl, aryl, aralkyl, alkaryl,
and cycloaliphatic groups, and salts of said acids; copolymers of said acid or its
salt with up to l0% by weight of one or more suitable comonomers; and mixtures of
said homopolymers and copolymers.
8. Composition of claim 3 wherein said active agent is selected from homopolymers
of acrylic acid itself or a salt thereof, copolymers thereof with up to l0% by weight
of one or more suitable comonomers, and mixtures thereof; and wherein said surfactant
is selected from anionic surfactants, nonionic surfactants, and mixtures thereof.
9. Composition of claim 8 wherein said comonomers are selected from acrylates of the
following formula:
CH₂=
-O-R
where R′ is selected from hydrogen, methyl, and ethyl groups; and R is selected from
alkyl groups of l0 to 30 carbon atoms and from alkyl, alkoxy, haloalkyl, and cyanoalkyl
groups containing l to 9 carbon atoms.
l0. Composition of claim 4 wherein said acid is selected from acrylic acid, methacrylic
acid, and mixtures of such acids; and amount of said comonomers is up to l0% selected
from alkyl acrylates and methacrylates containing l to 20 carbon atoms in the alkyl
group; said homopolymers and copolymers, in acid or salt form, have molecular weight
in the range of l00,000 to l0,000,000.
11. Composition of claim 4 wherein said active agent is selected from polymers of
acrylic acid, methacrylic acid, and mixtures of such acids; and amount of said comonomers
is up to l0% by weight which are selected from alkyl acrylates and methacrylates containing
l to 20 carbon atoms in the alkyl group; said homopolymers and copolymers, in acid
or salt form, have molecular weights in the range of about 200,000 to 5,000,000.
12. Composition of claim 4 wherein amount of said active agent is 0.l to 2% and wherein
said surfactant is selected from anionic surfactants, nonionic surfactants, and mixtures
thereof.
13. Composition of claim l2 containing water and other additives to l00% of total
composition.
14. Composition of claim l3 wherein said active agent is crosslinked with a small
amount of a crosslinking agent.
15. Composition of claim l3 wherein said active agent is crosslinked with 0.0l to
2% of a crosslinking agent selected from allyl sucrose, allyl pentaerythrytol, trimethylolpropane
diallyl ether and mixtures thereof.
16. Composition of claim l4 that is pourable at 40-200 cps range at 24°C wherein said
builder is selected from the group consisting of sodium laurate, sodium citrate, sodium
nitrilotriacetate, tetrapotassium pyrophosphate, sodium tripolyphosphate and mixtures
thereof.
17. A liquid detergent composition that is clear or transluscent, is pourable at room
temperature, and provides soil anti-redeposition function, improved cleaning performance,
and viscosity control comprising l to 60% by weight of total composition of at least
one surfactant, up to 20% by weight of total composition of at least one water-soluble
sequester builder, and a sufficient amount of an active agent to impart soil anti-redeposition
function and improved cleaning performance to said composition, said active agent
is selected from the group consisting of homopolymers of monounsaturated noncarboxylic
and dicarboxylic acids of 3 to 5 carbon atoms and salts thereof, copolymers thereof
with up to 20% by weight of one or more copolymerizable monomers, and mixtures of
such homopolymers and copolymers.
18. Composition of claim l7 wherein amount of said active agent is 0.05 to 5%, amount
of said surfactant is l0 to 40%, and amount of said builder is 0 to l0%, said builder
is selected from sequestrant builders and said active agent having molecular weight
in the range of l00,000 to l0,000,000.
19. Composition of claim l8 wherein said acid is selected from acrylic acid, methacrylic
acid, and mixtures of such acids; and amount of said comonomers is up to l0% selected
from alkyl acrylates and methacrylates containing l to 20 carbon atoms in the alkyl
group; said homopolymers and copolymers, in acid or salt form, have molecular weights
in the range of 200,000 to 5,000,000.
20. Composition of claim l9 containing water and other additives to l00%; and said
active agent is crosslinked with 0.0l to 2% of a crosslinking agent selected from
allyl sucrose, allyl pentaerylkrytol, trimethylol propane diallyl ether, and mixtures
thereof.