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Description  |
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TECHNICAL FIELD AND BACKGROUND ART
The invention relates to aqueous high sudsing liquid detergent compositions
containing specified amounts and types of ingredients especially useful in
the washing of tableware and kitchenware.
The compositions of this invention provide cleaning benefits not heretofore
obtained with liquid detergent compositions suitable for a hand
dishwashing process involving soaking tableware and kitchenware in dilute
solutions of the compositions followed by rinsing and draining.
A number of different types of soils are encountered in dishwashing. In
general, the detergent compositions developed for use in a hand
dishwashing process have a surfactant content that provides for removal of
natural fats and oils from tableware and kitchenware. Mildness to skin and
a level of suds to indicate cleaning potential are other factors usually
considered. Less attention has been given to removal of soils encountered
in hand dishwashing other than fats and oils. In particular, there is a
continuing need for detergent compositions that provide for faster and
more complete removal of protein and carbohydrate soils during a hand
dishwashing process. Ideally, such compositions will involve a compatible
combination of materials which will simultaneously provide the sudsing,
mildness and aesthetic attributes of an acceptable dishwashing detergent
composition as well as an improved ability to remove protein and
carbohydrate-based soils.
It is an object of the present invention to provide liquid detergent
compositions suitable for hand dishwashing and a process for hand
dishwashing that have an improved ability to remove protein and
carbohydrate-based soils.
The compositions of the present invention contain a reducing agent and a
nitrogen-containing protein denaturant as hereinafter specified. Detergent
compositions containing reducing agents and the operative protein
denaturants have been disclosed, but it has not been recognized that their
combination in specific liquid detergent compositions suitable for hand
dishwashing would provide a substantial advantage of protein and
carbohydrate soil removal in a hand dishwashing process.
U.S. Pat. No. 4,001,132 discloses granular automatic dishwasher detergent
compositions containing 15-60% of a mixture of water-soluble sulfites and
sulfates in a 1:4 to 2:1 weight ratio.
U.S. Pat. No. 3,149,042 discloses liquid hair care preparations containing
a reducing agent and a diamine compound such as urea, thiourea or biuret.
U.S. Pat. No. 3,700,601 discloses liquid detergent compositions containing
5-40% of anionic or nonionic surfactants, 0.1-5% of a chlorinated diphenyl
ether disinfectant and 0.01-5% by weight of the surfactant and
disinfectant of a water-soluble reducing agent.
Soviet Union Pat. No. 479,804 (Volskaya SA) discloses a detergent
composition containing surfactants, sodium silicate, sodium
tripolyphosphate, urea, capronamide and 3-6% ammonium bisulfate. The
composition is said to be a homogeneous mass providing a pH of 7-9 (1%
solution at 20.degree. C.).
SUMMARY OF THE INVENTION
The present invention encompasses liquid detergent compositions comprising:
(a) from about 15% to about 50% by weight of an anionic surfactant
(b) from about 2.5% to about 10% of an amide having the general formula
R.sub.1 --CO--N(H).sub.m (R.sub.2 OH).sub.2-m
wherein R.sub.1 is an aliphatic hydrocarbon radical having from about 7 to
about 21 carbon atoms, R.sub.2 is an aliphatic hydrocarbon radical having
from 1 to 3 carbon atoms and m is zero, 1 or 2,
(c) from about 2% to about 25% of a reducing agent selected from the group
consisting of water-soluble salts of reductive sulfur oxygen acids, salts
of reductive acids of phosphorus, inorganic reductive nitrogen compounds,
stannites and mixtures thereof,
(d) from about 2% to about 20% of a protein denaturant selected from the
group consisting of urea, guanidine and its salts, thiourea, biuret,
thiobiuret and the water soluble alkyl, alkylol and acyl derivatives of
these compounds, ammonia, alkanolamines, and mixtures thereof, and
(e) from about 20% to about 88.5% water,
said detergent composition providing a pH of at least 9.5 in a 0.4%
solution in water at 20.degree. C.
In the process or method aspect of the invention, dishware, glassware, and
other tableware and kitchenware are washed in water solutions of the
detergent composition, generally at a weight concentration of about 0.05%
to about 0.5% of the composition in water at a temperature of about
80.degree. F. to about 120.degree. F. The tableware and kitchenware is
then rinsed and drained.
DETAILED DESCRIPTION OF THE INVENTION
This invention relates to the liquid detergent compositions that provide
superior removal of protein and carbohydrate-based soils in a hand
dishwashing process.
While not intending to be limited by theory, it is believed that the
combination of the reducing agent, the protein denaturant as hereinafter
described and a solution pH above about 9.5 provide, in combination, the
conditions necessary to denaturize or otherwise degrade water-insoluble
protein into single chain water soluble protein derivatives, peptides or
other simpler structures. In particular, it is believed that the
combination of ingredients begins the denaturation of protein by the
breaking of disulfide cross-linkages in the protein polymer. This allows
subsequent and additional degradation via breakage of other structural
stabilizing bonds such as hydrogen or hydrophobic bonds.
The compositions of the present invention comprise five essential
components: an anionic surfactant, an amide, a reducing agent, a
nucleophilic protein denaturant and water, all as hereinafter defined.
Optional ingredients can be added to provide various performance,
aesthetic and product stability characteristics.
Anionic Surfactant
The compositions of this invention contain from about 15% to about 50% by
weight of an anionic surfactant or mixtures thereof. Preferred
compositions contain from about 20% to about 35% of anionic surfactant by
weight.
Most anionic detergents can be broadly described as the water-soluble
salts, particularly the alkali metal, alkaline earth metal, ammonium and
amine salts, of organic sulfuric reaction products having in their
molecular structure an alkyl radical containing from about 8 to about 22
carbon atoms and a radical selected from the group consisting of sulfonic
acid and sulfuric acid ester radicals. Included in the term alkyl is the
alkyl portion of acyl radicals. Examples of the anionic synthetic
detergents which can form the surfactant component of the compositions of
the present invention are the sodium, ammonium, potassium or magnesium
alkyl sulfates, especially those obtained by sulfating the higher alcohols
(C.sub.8 -C.sub.18 carbon atoms); sodium or magnesium alkyl benzene or
alkyl toluene sulfonates, in which the alkyl group contains from about 9
to about 15 carbon atoms, the alkyl radical being either a straight or
branched aliphatic chain; sodium or magnesium paraffin sulfonates and
olefin sulfonates in which the alkyl or alkenyl group contains from about
10 to about 20 carbon atoms; sodium C.sub.10-20 alkyl glyceryl ether
sulfonates, especially those ethers of alcohols derived from tallow and
coconut oil; sodium coconut oil fatty acid monoglyceride sulfates and
sulfonates; sodium, ammonium or magnesium salts of alkyl phenol ethylene
oxide ether sulfates with about 1 to about 30 units of ethylene oxide per
molecule and in which the alkyl radicals contain from 8 to about 12 carbon
atoms; the reaction products of fatty acids esterified with isethionic
acid and neutralized with sodium hydroxide where, for example, the fatty
acids are derived from coconut oil; sodium or potassium salts of fatty
acid amides of a methyl tauride in which the fatty acids, for example, are
derived from coconut oil and sodium or potassium beta-acetoxy- or
beta-acetamido-alkanesulfonates where the alkane has from 8 to 22 carbon
atoms.
Specific examples of alkyl sulfate salts which can be employed in the
instant detergent compositions include sodium lauryl alkyl sulfate, sodium
palmityl alkyl sulfate, sodium decyl sulfate, sodium myristyl alkyl
sulfate, potassium lauryl alkyl sulfate, potassium decyl sulfate,
potassium palmityl alkyl sulfate, potassium myristyl alkyl sulfate, sodium
dodecyl sulfate, magnesium dodecyl sulfate, sodium coconut alkyl sulfate,
potassium coconut alkyl sulfate, magnesium C.sub.12-15 alkyl sulfate and
mixtures of these surfactants. Preferred alkyl sulfates include sodium
C.sub.12-15 alkyl sulfate and magnesium C.sub.12-15 alkyl sulfate.
Suitable alkylbenzene or alkyltoluene sulfonates include the alkali metal
(lithium, sodium, potassium), alkaline earth (calcium, magnesium) ammonium
and alkanolamine salts of straight- or branched-chain alkylbenzene or
alkyltoluene sulfonic acids. Alkylbenzene sulfonic acids useful as
precursors for these surfactants include decyl benzene sulfonic acid,
undecyl benzene sulfonic acid, dodecyl benzene sulfonic acid, tridecyl
benzene sulfonic acid, tetrapropylene benzene sulfonic acid and mixtures
thereof. Preferred sulfonic acids as precursors of the alkyl-benzene
sulfonates useful for compositions herein are those in which the alkyl
chain is linear and averages about 11 to 13 carbon atoms in length.
Examples of commercially available alkyl benzene sulfonic acids useful in
the present invention include Conoco SA 515 and SA 597 marketed by the
Continental Oil Company and Calsoft LAS 99 marketed by the Pilot Chemical
Company.
Particularly preferred anionic surfactants useful herein are alkyl ether
sulfates having the formula RO(C.sub.2 H.sub.4 O).sub.x SO.sub.3 M wherein
R is alkyl or alkenyl of about 10 to about 20 carbon atoms, x is 1 to 30,
and M is a water-soluble cation. The alkyl ether sulfates useful in the
present invention are condensation products of ethylene oxide and
monohydric alcohols having from about 10 to about 20 carbon atoms.
Preferably, R has 10 to 16 carbon atoms. The alcohols can be derived from
natural fats, e.g., coconut oil or tallow, or can be synthetic. Such
alcohols are reacted with 1 to 30, and especially 1 to 12, molar
proportions of ethylene oxide and the resulting mixture of molecular
species is sulfated and neutralized.
Specific examples of alkyl ether sulfates of the present invention are
sodium coconut alkyl triethylene glycol ether sulfate, magnesium
C.sub.12-15 alkyl triethylene glycol ether sulfate, and sodium tallow
alkyl hexaoxy ethylene sulfate. Preferred alkyl ether sulfates are those
comprising a mixture of individual compounds, said mixture having an
average alkyl chain length of from about 12 to 16 carbon atoms and an
average degree of ethoxylation of from about 1 to 12 moles of ethylene
oxide.
Additional examples of anionic surfactants useful herein are the compounds
which contain two anionic functional groups. These are referred to as
di-anionic surfactants. Suitable dianionic surfactants are the
disulfonates, disulfates, or mixtures thereof which may be represented by
the following formula:
R(SO.sub.3).sub.2 M.sub.2,R(SO.sub.4).sub.2
M.sub.2,R(SO.sub.3)(SO.sub.4)M.sub.2
where R is an aliphatic hydrocarbyl group having 15 to 20 carbon atoms and
M is a water-solubilizing cation, for example, the C.sub.15 to C.sub.20
disodium 1,2-alkyldisulfates, C.sub.15 to C.sub.20 dipotassium
1,2-alkyldisulfonates or disulfates, disodium, 1,9-hexadecyl disulfates,
C.sub.15 to C.sub.20 disodium 1,2-alkyldisulfonates, disodium,
1,9-stearyldisulfates and 6,10-octadecyldisulfates.
Amide
The compositions of this invention contain from about 2.5% to about 10% of
an amide of a fatty acid. Preferred compositions contain from about 3.5%
to about 7% amide.
The amides suitable for use in the compositions of the invention provide a
stabilization of suds necessary to performance and acceptability of a hand
dishwashing product. The amide also assists in the cleaning function. The
amides of the invention have the general formula: R.sub.1 --CO--N(H).sub.m
(R.sub.2 OH).sub.2-m wherein R.sub.1 is an aliphatic hydrocarbon radical
having from about 7 to about 21 carbon atoms, R.sub.2 is an aliphatic
hydrocarbon radical having 1 to 3 carbon atoms and m is zero, 1 or 2.
Preferred amides are the monoethanol amides of C.sub.10-16 fatty acids.
Diethanol amides are less suitable and the semi-polar amine oxide nonionic
surfactants used as suds stabilizers in conventional liquid dishwashing
detergent compositions have not proven adequately stable in the
compositions of the present invention.
Reducing Agent
The compositions of this invention contain from about 2% to about 25%,
preferably from about 4% to about 20%, and most preferably from about 5%
to about 15% of a reducing agent selected from the group consisting of
water soluble salts of reductive sulfur oxygen acids, salts of reductive
acids of phosphorus, inorganic reductive nitrogen compounds and mixtures
thereof. Preferred reducing agents are the alkali metal, alkaline earth
metal, ammonium or substituted ammonium salts of sulfites, bisulfites,
thiosulfates and metabisulfites.
Examples of phosphorus-containing reducing agents are the salts of
phosphorus acid and sodium hypophosphite. Inorganic reductive nitrogen
compounds include salts of hydrazine or hydroxylamine. An example of a
stannite is sodium stannite.
The reducing agents of the invention have at least limited water
solubility, but are not necessarily completely in solution in the
compositions of the invention.
Surprisingly, the compositions of the invention do not have odor problems
typical of many compositions containing reducing agents.
Protein Denaturant
The compositions of this invention comprise from about 2% to about 20%,
preferably from about 3% to about 10%, by weight of a nitrogen-containing
protein denaturant. A characteristic feature of many of the operable
protein denaturants is an unshared pair of electrons and a resultant
designation as a nucleophilic reagent. Operative protein denaturants
include urea, guanidine and its salts, thiourea, biuret, thiobiuret and
the water-soluble alkyl, alkylol and acyl derivatives of these compounds,
ammonia (or ammonium ion to the extent it exists in the alkaline
compositions of the present invention), and the alkanolamines,
particularly monoethanolamine and triethanolamine, in free form or in
combined or ionic form, for example, as the cations of anionic
surfactants.
Particularly preferred protein denaturants are urea, ammonia,
monoethanolamine and mixtures thereof.
Water
The compositions of the invention contain from about 20% to about 88.5%
water. Preferred compositions contain from about 25% to about 60% water.
The compositions of the invention contain sufficient water-soluble alkaline
materials to provide a pH in a 0.4% water solution of at least about 9.5,
preferably from about 9.7 to about 10.5, measured at 20.degree. C.
In preferred compositions there is a reverse alkalinity equivalent to at
least about 1 gram of sodium hydroxide per 100 milliliters of the
detergent composition. Reserve alkalinity is measured by titration of a
10% solution of the composition in water with dilute hydrochloric to a pH
of 9.5. The weight equivalent of sodium hydroxide to the acid used to
reach pH 9.5 is defined as reserve alkalinity.
Optional Surfactants
The compositions of the invention can contain other optional surfactants
such as nonionic, ampholytic, zwitterionic and cationic surfactants.
Suitable nonionic surfactants include:
1. The polyethylene oxide condensates of alkyl phenols. These compounds
include the condensation products of alkyl phenols having an alkyl group
containing from about 8 to about 15 carbon atoms, in either a straight
chain or branched chain configuration, with ethylene oxide, the ethylene
oxide being present in amounts equal to from about 3 to about 9 moles of
ethylene oxide per mole of alkyl phenol. The alkyl substituent in such
compounds may be derived, for example, from polymerized propylene or
isobutylene, or from octene or nonene. Examples of compounds of this type
include nonyl phenol condensed with about 9 moles of ethylene oxide per
mole of nonyl phenol and dodecyl phenol condensed with about 8 moles of
ethylene oxide per mole of dodecyl phenol. Commercially available nonionic
surfactants of this type include Igepal CO-610, CA-420, CA-520 and CA-620,
marketed by the GAF Corporation, and Triton X-45, X-114, X-100 and X-102,
marketed by the Rohm and Haas Company.
2. The condensation products of aliphatic alcohols with ethylene oxide. The
alkyl chain of the aliphatic alcohol may either be straight or branched
and contains from about 8 to about 18 carbon atoms. Examples of such
ethoxylated alcohols include the condensation product of about 5 moles of
ethylene oxide with 1 mole of tridecanol, myristyl alcohol condensed with
about 8 moles of ethylene oxide per mole of myristyl alcohol, the
condensation product of ethylene oxide with coconut fatty alcohol wherein
the coconut alcohol is a mixture of fatty alcohols with alkyl chains
varying from 10 to 14 carbon atoms and wherein the condensate contains
about 6 moles of ethylene oxide per mole of alcohol, and the condensation
product of about 9 moles of ethylene oxide with coconut alcohol. Examples
of commercially available nonionic surfactants of this type include
Tergitol 15-S-7 marketed by the Union Carbide Corporation and Neodol
23-6.5 marketed by the Shell Chemical Company. Whether the alcohol is
derived from natural fats or produced by one of several petrochemical
processes, a mixture of carbon chain lengths is typical. The stated degree
of ethoxylation is an average, the spread being dependent on process
conditions, including choice of catalyst.
Ethoxylated alcohols are preferred because of their superior
biodegradability relative to ethoxylated alkyl phenols. Particularly
preferred are ethoxylated alcohols having an average of from about 10 to
about 14 carbon atoms in the alcohol and an average degree of ethoxylation
of from about 4 to about 6 moles of ethylene oxide per mole of alcohol.
Ampholytic surfactants can be broadly described as derivatives of aliphatic
amines which contain a long chain of from about 8 to about 18 carbon atoms
and an anionic water-solubilizing group, e.g. carboxy, sulfonate or
sulfate. Examples of compounds falling within this definition are
sodium-3-dodecylamino propane sulfonate, and dodecyl dimethylammonium
hexanoate.
Zwitterionic surface active agents operate in the instant composition are
broadly described as internally-neutralized derivatives of aliphatic
quanternary ammonium and phosphonium and tertiary sulfonium compounds in
which the aliphatic radical can be straight chain or branched, and wherein
one of the aliphatic substituents contains from about 8 to 18 carbon atoms
and one contains an anionic water solubilizing group, e.g., carboxy,
sulfo, sulfato, phosphato, or phosphono.
Cationic surfactants such as quaternary ammonium compounds can find
optional use in the practice of the invention to the extent they are
compatible with the other surfactants in the particular composition.
Other Optional Components
The detergent compositions herein optionally, but preferably, also contain
detergent builder materials. A preferred range of detergency builder
materials is from about 5% to about 25% by weight. Detergency builders are
generally characterized by an ability to sequester or precipitate water
hardness ions, particularly calcium and magnesium. They may also be used
to maintain or assist in maintaining the necessary alkaline pH of the
washing solution.
All manner of detergency builders commonly taught for use in detergent
compositions are suitable for use herein. Useful binders include any of
the conventional inorganic and organic water-soluble builder salts.
Such detergency builders can be, for example, water-soluble salts of
phosphates, pyrophosphates, orthophosphates, polyphosphates, phosphonates,
carbonates, polyhydroxysulfonates, silicates, polyacetates, carboxylates,
polycarboxylates and succinates. Specific examples of inorganic phosphate
builders include sodium and potassium pyrophosphates, tripolyphosphates,
orthophosphates, and metaphosphates. The polyphosphonates specifically
include, for example, the salts of ethylene diphosphonic acid, the salts
of ethane 1-hydroxy-1,1-diphosphonic acid and the salts of
ethane-1,1,2-triphosphonic acid. Examples of these and other phosphorus
builder compounds are disclosed in U.S. Pat. Nos. 3,159,581; 3,213,030;
3,422,021; 3,422,137; 3,400,176 and 3,400,148, incorporated herein by
reference.
Non-phosphorus containing sequestrants can also be selected for use herein
as detergency builder.
Specific examples of non-phosphorus, inorganic builder ingredients include
water-soluble inorganic carbonate, bicarbonate, and silicate salts. The
alkali metal, e.g., sodium and potassium, carbonates and silicates are
particularly useful herein.
Water-soluble, organic builders are also useful herein. For example, the
alkali metal, ammonium and substituted ammonium polyacetates,
carboxylates, polycarboxylates and polyhydroxysulfonates are useful
builders in the present compositions and processes. Specific examples of
the polyacetate and polycarboxylate builder salts include sodium,
potassium, lithium, ammonium and substituted ammonium salts of ethylene
diamine tetraacetic acid, nitrilotriacetic acid, oxydisuccinic acid,
mellitic acid, benzene polycarboxylic acids, and citric acid.
Other suitable polycarboxylates for use herein are the polyacetal
carboxylates fully described in U.S. Pat. No. 4,144,226, issued Mar. 13,
1979 to Crutchfield, et al., and U.S. Pat. No. 4,146,495, issued Mar. 27,
1979 to Crutchfield, et al., the disclosures of which are incorporated
herein by reference. These polyacetal carboxylates can be prepared by
bringing together under polymerization conditions an ester of glyoxylic
acid and a polymerization initiator. The resulting polyacetal carboxylate
ester is then attached to chemically stable end groups to stabilize the
polyacetal carboxylate against rapid depolymerization in alkaline
solution, converted to the corresponding salt, and added to a surfactant.
Preferred non-phosphorus builder materials herein include sodium carbonate,
sodium bicarbonate, sodium silicate, sodium citrate, sodium
oxydisuccinate, sodium mellitate, sodium nitrilotriacetate, and sodium
ethylenediaminetetraacetate, and mixtures thereof.
Other preferred builders herein are the polycarboxylate builders set forth
in U.S. Pat. No. 3,308,067, Diehl, incorporated herein by reference.
Examples of such materials include the water-soluble salts of homo- and
co-polymers of aliphatic carboxylic acids such as maleic acid, itaconic
acid, mesaconic acid, fumaric acid, aconitic acid, citraconic acid and
methylenemalonic acid.
Additional, preferred builders herein include the water-soluble salts of
carboxymethyloxymalonate, carboxymethyloxysuccinate,
cis-cyclohexanehexacarboxylate, cis-cyclopentanetetracarboxylate
phloroglucinol trisulfonate, and the copolymer of maleic anhydride with
vinyl methyl ether or ethylene.
A further class of detergency builder materials useful in the present
invention are insoluble sodium aluminosilicates, particularly those
disclosed in Belgian Pat. No. 814,874 issued Nov. 12, 1974 and
incorporated herein by reference. This patent discloses detergent
compositions containing sodium aluminosilicates of the formula
Na.sub.z (AlO.sub.2).sub.z (SiO.sub.2).sub.y xH.sub.2 O
wherein z and y are integers of at least 6, the molar ratio of z to y is in
the range from 1.0:1 to about 0.5:1 and x is an integer from about 15 to
about 264, said aluminosilicates having a calcium ion exchange capacity of
at least 200 mg. eq./gm. and a calcium ion exchange rate of at least about
2 grains/gallon/minute/gram. A preferred material is Na.sub.12
(SiO.sub.2.AlO.sub.2).sub.12.27H.sub.2 O. Aluminosilicates for use herein
include the amorphous and crystalline aluminosilicates disclosed in the
pending U.S. patent application of Rodriguez, et al., Ser. No. 049,704,
filed June 18, 1979, incorporated herein by reference. Particularly useful
aluminosilicates are those commonly known as Zeolites A, X, and P(B).
Alcohols, such as ethyl alcohol, and hydrotropes, such as sodium and
potassium toluene sulfonate, sodium and potassium xylene sulfonate,
trisodium sulfosuccinate and related compounds (as disclosed in U.S. Pat.
No. 3,915,903, incorporated herein by reference) can be utilized in the
interests of achieving a desired product phase stability and viscosity.
Ethyl alcohol at a level of from about 3% to about 15% and potassium or
sodium toluene, xylene or cumene sulfonate at a level of from about 1% to
about 6% are particularly useful in the compositions of the invention.
The detergent compositions of this invention can contain, if desired, any
of the usual adjuvants, diluents and additives, for example, perfumes,
enzymes, dyes, antitarnishing agents, antimicrobial agents, and the like,
without detracting from the advantageous properties of the compositions.
Alkalinity sources and pH buffering agents such as alkali metal hydroxides
can also be utilized.
As noted hereinbefore, the compositions of the invention can contain
materials which are insoluble or not completely soluble at the levels
employed in a particular composition.
Particularly useful in such compositions are suspending or thickening
agents such as those disclosed in U.S. Pat. No. 3,393,153 incorporated
herein by reference including colloidal silica having a mean particle
diameter ranging from about 0.01 micron to about 0.05 micron, colloidal
clays such as bentonites or chemically treated bentonites, isomorphous
silicates, especially those with a high magnesium content, particulate
polymers such as polystyrene, oxidized polystyrene having an acid number
of from 20 to about 40, sulfonated polystyrene having an acid number of
from about 10 to about 30, polyethylene, oxidized polyethylene having an
acid number of from about 10 to about 30; sulfonated polyethylene having
an acid number of from about 5 to about 25; polypropylene, oxidized
polypropylene having an acid number of from about 10 to about 30 and
sulfonated polypropylene having an acid number of from about 5 to about
25, all of said particulate polymers having mean particle diameters
ranging from about 0.01 micron to about 30 microns. Other examples of
suspending and thickening agents include copolymers of styrene with
monomers such as maleic anhydride, nitrilonitrile, methacrylic acid and
lower alkyl esters of methacrylic acid, copolymers of styrene with methyl
or ethyl acrylate, methyl or ethyl maleate, vinyl acetate, acrylic maleic
or fumaric acids and mixtures thereof. The mole ratio of ester and/or acid
to styrene is preferably in the range from about 4 to about 40 styrene
units per ester and/or acid unit. Such materials preferably have a mean
particle diameter range of from about 0.05 micron to about 1 micron and
molecular weights ranging from about 500,000 to about 2,000,000.
Cellulosic polymers such as carboxymethyl cellulose and hydroxypropyl
cellulose and gums such as guar gum and gum tragacanth are also suitable
suspending and thickening agents.
The following non-limiting examples illustrate the detergent compositions
of the present invention. All percentages, parts or ratios used herein are
by weight unless otherwise specified.
EXAMPLE I
The following liquid detergent composition was prepared by mixing the
listed ingredients:
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Sodium coconut alkyl sulfate
11.5%
Sodium coconut alkyl ethoxyethersulfate
14.0
(3 moles ethylene oxide/mole alkyl sulfate)
Coconut monoethanol amide 5.0
Monoethanolamine 3.0
Na.sub.2 SO.sub.3 12.5
Sodium nitrilotriacetate 5.0
Potassium sulfosuccinate 2.6
Bentonite L Clay 2.5
Ethanol 9.5
K.sub.4 P.sub.2 O.sub.7 1.0
Na.sub.2 CO.sub.3 0.1
Water & Miscellaneous 33.3
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The resultant composition was a stable suspension and provided a pH of 9.7
in a 0.4% water solution. Glass test strips carrying baked-on (400.degree.
F., 30 minutes) egg and macaroni and cheese soils, were soaked in 0.4%
water solutions of the detergent composition at 115.degree. F. for 15
minutes. The effort required to remove the soils after the soaking step
was measured using a "Gardner Straight Line Washability and Abrasion
Machine". The first ten strokes of the machine were made with a one-pound
weight mounted over a holder with a sponge saturated with a 0.4% water
solution of the composition. The next ten strokes were made with a
three-pound weight over the sponge and the final ten strokes were made
with a six-pound weight. The percentage of soil removed after each ten
stroke cycle was recorded.
The detergent composition of Example I provided a 40-50% soil removal after
10 strokes, 60-70% soil removal after 20 strokes and 70-80% soil removal
after 30 strokes. A comparable composition containing no monoethanolamine
or sodium sulfite and having a pH of about 7 in a 0.4% water solution
provided less than 10% soil removal after 30 strokes.
A composition is prepared in which the 3.0% monoethanolamine and 7% of the
water is replaced by 10.0% urea and sufficient NaOH replaces water to
provide a pH above 9.5 in 0.4% water solution. Comparable cleaning results
are obtained. Comparable cleaning results are also obtained when sodium
thiosulfate or sodium metabisulfite replace sodium sulfite.
EXAMPLE II
The following liquid detergent compositions within the scope of the present
invention are prepared:
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A B C D E F
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Sodium C.sub.12-15 alkyl sulfate
12 10 -- 2 -- 14 (Mg)*
Ammonium.sub.12-15 alkyl ethoxy-
ethersulfate (3 moles ethylene
oxide/mole alkyl sulfate)
15 15 15 15 -- 12 (Mg)*
Sodium C.sub.14-16 parrafin
sulfonate -- -- 15 -- -- --
Sodium C.sub.11-13 alkylbenzene
sulfonate -- -- -- -- 20 --
Coconut monoethanol amide
-- 5 7 3 5 7
Coconut ammonia amide
6 -- -- 3 -- --
Na.sub.2 SO.sub.3
-- 6 12 6 -- 12
Na.sub.2 S.sub.2 O.sub.3
12 -- -- -- 6 --
Na.sub.2 S.sub.2 O.sub.5
-- 6 -- 6 -- --
K.sub.4 P.sub.2 O.sub.7
10 -- -- 5 -- --
Sodium nitrilotriacetate
-- -- 6 4 -- --
Monoethanolamine -- -- 3 -- 4 5
Triethanolamine 4 -- -- -- -- --
Urea -- 10 -- -- 4 --
Water and miscellaneous
Remainder
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*Magnesium alkyl sulfate and magnesium alkyl ethoxyether sulfate
Compositions A, B, C, D, E and F all provide improved protein and
carbohydrate soil cleaning relative to compositions not containing both a
reducing agent and a nitrogen-containing protein denaturant. The
compositions all contain from 20% to 88.5% water and provide a pH of at
least 9.5 in a 0.4% solution in water at 20.degree. C.
* * * * *
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