US3794605A - Built detergent composition containing whiteness maintenance additive - Google Patents

Abstract

A BUILT DETERFENT COMPOSITION IS FORMULATED HAVING EXCELLENT WHITENESS MAINTENANCE PROPERTIES. THE BUILT DETERGENT COMPOSITION HAS INCLUDED THEREWITH FROM 0.1% TO 20% OF A MIXTURE OF THE WATER-SOLUBLE SALTS OF A CELLULOSE SULFATE ESTER AND A COPOLYMER OF A VINYL COMPOUMD AND MALEIC ANHYDRIDE, THE MIXTURE OF THE SULFATE ESTER AND COPOLYMER WHEN ADDED TO A BUILT DETERGENT COMPOSITION IMPROVES THE WHITENESS MAINTENANCE OF FABRICS WASHED THEREWITH OVER A BUILT DETERGENT COMPOSITION CONTAINING EITHER COMPONENT ALONE.

Description

United States Patent O 3,794,605 BUILT DETERGENT COMPOSITION CONTAINING WHITENESS MAINTENANCE ADDITIVE Francis L. Diehl, Wyoming, Ohio, assignor to The Procter & Gamble Company, Cincinnati, Ohio N Drawing. Filed July 19, 1971, Ser. No. 164,067

Int. Cl. Clld 3/34 U.S. Cl. 252-89 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION This invention relates to built detergent compositions containing an additive which effectively prevents the deposition of removed soil and hardness ion-builder salts or complexes formed during the laundering of textile fabrics. More particularly, the whiteness maintenance of fabrics washed with the composition of this invention is improved.

The washing of soiled fabrics with a laundry detergent is essentially a two-step process. In the first stage the detergent removes the soil particles from the fabrics and suspends them in the wash solution. In the second stage the detergent must prevent the soil particles and other insolubles from redepositing on the cloth before the fabric is removed from the dirty soil solution or during the rinse cycles. The exact mechanism by which the second stage operates is not known. It is theorized that a charge is formed on the fabric being washed and that this charge repels the soil particles which carry a similar charge. If soil particles once removed from the fabrics are allowed to redeposit thereon the resultant fabrics once dried will have an unclean appearance. This appearance can be traced directly to the redeposited soil particles and can be measured quantitatively in terms of a whiteness value, as hereinafter explained. The amount of redeposited soil particles as measured by the whiteness value is an indication of the whiteness maintenance property of a detergent composition.

Another factor that has an effect on the whiteness maintenance is the deposition of water-insoluble hardness ion-builder salts or complexes on the fabrics. This factor can be as important as the prevention of soil redeposition with regard to whiteness maintenance. The formation of hardness ion-insoluble salts is most noticeable with detergent compositions containing builders such as polymaleate, polyacrylate of high molecular weight, tripolyphosphates, pyrophosphates, and carbonates when such compositions are used at low ratios of builder to hardness The inclusion of whiteness maintenance additives in detergent compositions is a common practice and a number of such additives are known that do a relatively effective job. Among the whiteness maintenance additives suggested for inclusion in a detergent composition are carbbxymethylcellulose salts, sodium cellulose acetate sulfate, salts of cellulose and starch sulfate, carboxyalkylcellulose, and hydroxyalkylcellulose. Various combinations of the noted compounds have also been suggested as having utility in a detergent composition.

3,794,605 Patented Feb. 26, 1974 "Ice While the above known additives perform satisfactorily, a whiteness maintenance additive mixture has now been discovered that performs eminently Well when used in a built detergent composition. The novel mixture of this invention is especially useful in detergent compositions built with polymaleate salts.

Accordingly, it is an object of this invention to improve the whiteness maintenance values of detergent compositions.

It is another object of this invention to provide a new and improved detergent whiteness maintenance additive which when included in a built detergent composition provides satisfactory whiteness maintenance.

It is still another object of this invention to provide a built detergent composition that is effective in maintaining the original appearance of fabrics or like materials.

A still further object of this invention is to provide a built detergent composition that cleans satisfactorily and possesses satisfactory whiteness maintenance values.

Another object of this invention is to formulate a polymaleate-built detergent composition possessing excellent whiteness maintenance properties.

These and other objects will become apparent from the description that follows.

SUMMARY OF THE INVENTION An effective detergent additive composition is provided for preventing the redeposition of soil particles and deposition of hardness ion-builder salts and hence improving the whiteness maintenance value of laundered fabrics. The detergent additive composition consists essentially of a mixture of the water-soluble salts of (a) a cellulose sulfate ester and (b) a copolymer of a vinyl compound and maleic anhydride in a proportion of from 1:300 to 9:1, by weight respectively. More particularly a built detergent composition embodying the present invention comprises a builder salt and a detergent selected from the group consisting of anionic, nonionic, zwitterionic, and ampholytic detergents in a builder to detergent weight ratio of from 1:10 to 10:1 and from 0.1% to 20% of a mixture of cellulose sulfate ester and a copolymer of a vinyl compound and maleic anhydride in a weight ratio of from 1:300 to 9:1, respectively.

DESCRIPTION OF THE INVENTION The present invention relates to a novel whiteness maintenance additive and to built detergent compositions containing same.

The whiteness maintenance property of a built detergent composition as used herein refers to the ability of the detergent composition to prevent the redeposition of soil and the deposition of hardness ion builder salts onto laundered fabric-s, Both the aforementioned soil and hardness ion salts have an adverse effect on the appearance of washed fabrics. That is, fabrics washed with a built detergent composition possessing poor whiteness maintenance properties will after relatively few washes take on a greyish color. This change in color is attributed to a combination of redeposited soil and deposited hardness ion salts.

The whiteness maintenance additive of this invention consists of a mixture of the water-soluble salts of a cellulose sulfate ester and a copolymer of a vinyl compound and maleic anhydride. Cellulose sulfate esters have been used as soil-suspending additives in detergent formulations previously. The water-soluble salt of a copolymer of a vinyl compound and maleic anhydride has also been used in detergent compositions previously. However, it was surprisingly discovered that a mixture of the two compounds when used in a built detergent composition improves whiteness maintenance in a synergistic manner. That is, the mixture of this invention in the ratio herein specified significantly provides a whiteness maintenance improvement in a built detergent composition over such a composition containing either component alone at the same usage level.

The cellulose sulfate ester salts of this invention are known compounds. The cellulose sulfate ester salts used herein have a molecular weight of from 15,000 to 1,000,000, preferably from 36,000 to 350,000 and a degree of sulfate substitution of from 0.2 to 1.

A degree of sulfate substitution above 1 should be avoided since decreased soil antiredeposition is obtained. Similarly a degree of sulfate substitution below 0.2 should be avoided because decreased soil antiredeposi-tion is obtained with such compounds. Preferably the degree of sulfate substitution is from 0.3 to 0.8.

Examples of suitable cellulose sulfate esters are the water-soluble salts of cellulose acetate sulfate, cellulose sulfate, hydroxyethylcellulose sulfate, methylcellulose sulfate, and hydroxypropylcellulose sulfate. The degree of,

substitution of the nonionic substituent of the above com pounds, i.e. the acetate, hydroxymethyl, methyl, and hydroxypropyl substituents as well as of other cellulose sulfate ester compounds ranges up to 2.5 and preferably is from 0.5 to 2.2. The above list is a compilation of suitable cellulose sulfate esters that are used in this invention. It should not be taken as being all inclusive since others will be apparent to those skilled in the detergency art.

Examples of water-soluble cations that form the salts of the sulfate esters of this invention are the alkali metals, e.g. sodium and potassium. Sodium is especially preferred. Other cations that are suitable are ammonium and sub stitutcd ammonium compounds, such as mono-, di-, and trialkylammonium, mono-, di-, and triethylammonium, mono-, di-, and trimethylammonium and mono-, di-, and triethanolammonium.

Of the cellulose sulfate esters that are used in this invention, sodium cellulose acetate sulfate and sodium cellulose sulfate are most preferred.

The other necessary component of the mixture of this invention is a water-soluble salt of a copolymer of a vinyl compound and maleic anhydride. The vinyl compound is of the formula CH =CHY wherein Y represents a C alkyl ether radical. The cation that forms the water-soluble salt for this copolymer is selected from the group of cations listed above for the cellulose sulfate esters. These copolymer compounds have a molecular weight between 5,000 and 1,000,000, preferably between 10,000 and 350,000.

It has been found that a mixture of the Water-soluble salts of cellulose sulfate ester and a copolymer of the vinyl compound and maleic anhydride when employed in a built detergent composition in a minor amount, i.e. in an amount ranging from 0.1% to 20% of the total composition by weight provides a very effective whiteness maintenance additive. Useage levels below 0.1% are not noticeably effective. A useage level above 20% can be used but it provides no noticeable increase in whiteness maintenance. Preferably from 1% to 12% by weight of the total built detergent composition is the mixture of this invention.

Useful proportions for preparing the mixtures of the additives of this invention on a weight basis of cellulose sulfate ester to copolymer of the vinyl compound and maleic anhydride are from 1:300 to 9:1, preferably from 1:90 to 3:1. An ester to copolymer ratio of less than 1:300 give unsatisfactory white maintenance results in that excess soil particles are redeposited onto the textiles. An ester to copolymer ratio greater than 9:1 also gives poorer whiteness maintenance results in that excessive hardness ion builder salts are free to deposit onto the textiles.

The whiteness maintenance additive of this invention is embodied in a built detergent composition containing a water-soluble salt and a deter-gent in a builder salt to detergent weight ratio of from 1:10 to 10:1. The built detergent composition has the following formulation:

(a) from 5% to of a water-soluble builder salt;

(b) from 5% to 60% of a detergent selected from the group consisting of nonionic, anionic, zwitterionic, and ampholytic detergents; and

(c) from 0.1% to 20% of a mixture of the water-soluble salts of (a) a cellulose sulfate ester and (b) a copolymer of a vinyl compound and maleic anhydride as hereinbefore defined in a weight ratio of from 1:300 to 9:1, respectively,

all by percent by weight of the total composition.

In a very preferred built detergent composition the Weight ratio of builder salt to detergent is from 1:2 to 5:1.

Examples of builders and detergents useful in the present invention are set out below.

(A) Anionic soap and non-soap synthetic detergents This class of detergents includes ordinary alkali metal soaps such as the sodium, potassium, ammonium and alkylolammonium salts higher fatty acids containing from about 8 to about 24 carbon atoms and preferably from about 10 to about 20 carbon atoms. Suitable fatty acids can be obtained from natural sources such as, for instance, from plant and animal esters (e.g., palm oil, coconut oil, babassu oil, soybean oil, castor oil, tallow, whale and fish oils, grease, lard, and mixtures thereof). The fatty acids also can be synthetically prepared (e.g., by the oxidation of petroleum, or by hydrogenation of carbon monoxide by the Fischer-Tropsch process). Resin acids are suitable such as rosin and those resin acids in tall oil. Naphthenic acids are also suitable. Sodium and potassium soaps can be made by direct saponification of the fats and oils or by the neutralization of the free fatty acids which are prepared in a separate manufacturing process. Particularly useful are the sodium and potassium salts of the mixtures of fatty acids derived from coconut oil and tallow, i.e., sodium or potassium tallow and coconut soap.

This class of detergents also includes water-soluble salts, particularly the alkali metal 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 sulfonic acid or sulfuric acid ester radical. (Included in the term alkyl is the alkyl portion of higher acyl radicals.) Examples of this group of synthetic detergents which form a part of the preferred built detergent compositions of the present invention are the sodium or potassium alkyl sulfates, especially those obtained by sulfating the higher alcohols (C -C carbon atoms) produced by reducing the glycerides of tallow or coconut oil; sodium or potassium alkyl benzene sulfonates, in Which the alkyl group contains from about 9 to 15 carbon atoms, in straight chain or branched chain configuration, e.g. those of the type described in United States Letters Patents Numbers 2,220,099 and 2,477,383 (especially valuable are linear straight chain alkyl benzene sulfonates in which the average of the alkyl groups is about 13 carbon atoms abbreviated hereinafter as C LAS); sodium alkyl glyceryl ether sulfonates, especially those ethers of higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulfonates and sulfates; sodium or potassium salts of sulfuric acid esters of the reaction product of one mole of a higher fatty alcohol (e.g. tallow or coconut oil alcohols) and about 1 to 6 moles of ethylene oxide; sodium or potassium salts of alkyl phenol ethylene oxide ether sulfate with about 1 to about 10 units of ethylene oxide per molecule and in which the alkyl radicals contain about 8 to about 12 carbon atoms.

Anionic phosphate surfactants are also useful in the present invention. These are surface active materials having substantial detergent capability in which the anionic solubilizing group connecting hydrophobic moieties is an oxy acid of phosphorus. The more common solubilizing groups, of course, are -SO H, -SO H, and -CO H. Alkyl phosphate esters such as (RO') PO H and in which R represents an alkyl chain containing from about 20 carbon atoms are useful.

These esters can be modified by including in the molecule from one to about 40 alkylene oxide units, e.g., ethylene oxide units. Formulae for these modified phosphate anionic detergents are in which R represents an alkyl group containing from about 8 to 20 carbon atoms, or an alkylphenyl group in which the alkyl group contains from about 8 to 20 carbon atoms, and M represents a soluble cation such as hydrogen, sodium, potassium, ammonium or substituted ammonium; and in which n is an integer from 1 to about 40.

Another class of suitable anionic organic detergents particularly useful in this invention includes salts of 2- acyloxy-alkane-l-sulfonic acids. These salts have the formula where R is alkyl of about 9 to about 23 carbon atoms (forming with the two carbon atoms an alkane group);

R is alkyl of 1 to about 8 carbon atoms; and M is a salt-forming radical.

The salt-forming radical M in the hereinbefore described structural formula is a water-solubilizing cation and can be for example, an alkali metal cation (e.g. so dium, potassium, lithium), ammonium or substitutedammonium cation. Specific examples of substituted ammonium cations include methyl-, dimethyl-, and trimethylammonium cations and quaternary ammonium cations such as tetramethyl-ammonium and dimethyl piperidinium cations and those derived from alkylamines such as ethylamine, diethylamine, triethylamine, mixtures thereof, and the like.

Specific examples of B-acyloxy-alkane-l-sulfonates, or alternatively 2-acyloxyalkane-l-sulfonates, utilizable herein to provide superior cleaning levels under substantially neutral washing conditions include the sodium salt of 2-acetoxy-tridecane-l-sulfonic acid; the potassium salt of 2-propi0nyloxy tetradecane-l-sulfonic acid; the lithium salt of 2-butanoyloxy-tetradecane-l-sulfonic acid; the sodium salt of 2-pentanoyloxy-pentadecane-l-sulfonic acid; the sodium salt of 2-acetoxy-hexadecane-l-sulfonic acid; the potassium salt of 2-octanoyloxy-tetradecane-1- sulfonic acid; the sodium salt of 2-acetoxy-heptadecane-lsulfonic acid; the lithium salt of 2-acetoxy-octadecane-1- sulfonic acid; the potassium salt of 2-acetoxy-nonadecanel-sulfonic acid; the sodium salt of 2-acetoxy-uncosane-1- sulfonic acid; the sodium salt of 2-propionyloxy-docosanel-sulfonic acid; the isomers thereof.

Preferred fi-acyloxy-alkane-l-sulfonate salts therein are the alkali metal salts of fl-acetoxy-alkane-l-sulfonic acids corresponding to the above formula wherein R is an alkyl of about 12 to about 16 carbon atoms, these salts being preferred from the standpoints of their excellent cleaning properties and ready availability.

Typical examples of the above described fi-acetoxy alkanesulfonates are described in the literature: Belgium Pat. 650,323 issued July 9, 1963, discloses the preparation of certain 2-acyloxy alkanesulfonic acids. Similarly, US.

Pat. 2,094,451 issued Sept. 28, 1937, to Guenther et al. and 2,086,215 issued July 6, 1937 to De Groote disclose certain salts of ,B-acetoxy alkanesulfonic acids. These references are hereby incorporated by reference.

A preferred class of anionic organic detergents are the B-alkyloxy alkane sulfonates. These compounds have the following formula:

where R is a straight chain alkyl group having from 6 to 20 carbon atoms, R is a lower alkyl group having from 1 to 3 carbon atoms, and M is a salt-forming radical hereinbefore described.

Specific examples of fl-alkyloxy alkane sulfonates or alternatively 2-alkyloxy alkane 1 sulfonates, utilizable herein to provide superior cleaning and whitening levels under household washing conditions include potassium B-methoxydecanesulfonate, sodium fi-methoxy-tridecanesulfonate, potassium fi-ethoxytetradecylsulfonate, sodium p-isopropoxyhexadecylsulfonate, lithium fi-t-butoxytetradecylsulfonate, sodium ,8-methoxyoctadecylsulfonate, and ammonium B-n-propoxydodecylsulfonate.

Other synthetic anionic detergents useful herein are alkyl ether sulfates. These materials have the formula RO(C H O) SO' M wherein R is alkyl or alkenyl of about 10 to about 20 carbon atoms, x is 1 to 30, and Mis a salt-forming cation defined hereinbefore.

The alkyl ether sulfates of the present invention are condensation products of ethylene oxide and monohydric alcohols having about 10 to about 20 carbon atoms. Preferably, R has 14 to 18 carbon atoms. The alcohols can be derived from fats, e.g., coconut oil or tallow, or can be synthetic. Lauryl alcohol and straight chain alcohols derived from tallow are preferred herein. Such alcohols are reacted with 1 to 30, and especially 6, molar proportions of ethylene oxide and the resulting mixture of molecular species, having, for example, an average of 6 moles of ethylene oxide per mole of alcohol, is sulfated and neutralized.

Specific examples of alkyl ether sulfates of the present invention are sodium coconut alkyl ethylene glycol ether sulfate; lithium tallow alkyl triethylene glycol ether sulfate; and sodium tallow alkyl hexaoxyethylene sulfate.

Preferred herein for reasons of excellent cleaning properties and ready availability are the alkali metal coconutand tallow-alkyl oxyethylene ether sulfates having an average of about 1 to about 10 oxyethylene moieties. The alkyl ether sulfates of the present invention are known compounds and are described in US. Pat. 3,332,- 876 to Walker (July 25, 1967) incorporated herein by reference.

Additional examples of anionic non-soap synthetic detergents which come within the terms of the present invention are 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 amide of methyl tauride in which the fatty acids, for example, are derived from coconut oil. Other an ionic synthetic detergents of this variety are set forth in United States Letters Pats. 2,486,921; 2,486,922; and 2,396,278.

Additional examples of anionic, non-soap, synthetic detergents, which come within the terms of the present invention, are the compounds which contain two anionic functional groups. These are referred to as di-anionic detergents. Suitable di-anionic detergents are the disulfonates, disulfates, or mixtures thereof which may be represented by the following formulae:

where R is an acyclic aliphatic hydrocarbyl group having 15 to 20 carbon atoms and M is a water-solubilizing cation, for example, the C to C disodium 1,2-alkyldisulfates, C to C dipotassium-1,2-alkyldisulfonates or disulfates, disodium 1,9-hexadecy1 disulfates, C to C disodium-1,2-alkyldisulfonates, disodium 1,9-stearydisulfates and 6,10-octaecyldisulfates.

The aliphatic portion of the disulfates or disulfonates is generally substantially linear, desirable, among other reasons, because it imparts desirable biodegradable properties to the detergent compound.

The water-solubilizing cations include the customary cations known in the detergent art, i.e., the alkali metals, and the alkaline earth metals, as well as other metals in group H-A, II-B, IIIA, IV-A and IV-B of the Periodic Table except for boron. The preferred water-solubilizing cations are sodium or potassium. These dianionic detergents are more fully described in British Letters Pat. 1,151,392 which claims priority on an application made in the United States of America (No. 564,556) on July 12, 1966.

Additional examples of anionic non-soap synthetic detergents which come within the terms of the present invention are the reaction product 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 amide of methyl tauride in which the fatty acids, for example, are derived from coconut oil. Other anionic synthetic detergents of this variety are set forth in United States Letters Pats. 2,486,921, 2,486,922; and 2,396,278.

Still other anionic synthetic detergents include the class designated as succinamates. This class includes such surface active agents as disodium N-octadecylsulfo succinamate; tetrasodium N-(l,2-dicarboxyethyl) N octadecyl-sulfo-succinamate; diamyl ester of sodium sulfosuccinic acid; dihexyl ester of sodium sulfosuceinic acid; dioctyl ester of sodium sulfosuccinic acid.

Other suitable anionic detergents utilizable herein are olefin sulfonates having about 12 to about 24 carbon atoms. The term olefin sulfonates is used herein to mean compounds which can be produced by the sulfonation of u-olefin by means of uncomplexed sulfur trioxide, followed by neutralization of the acid reaction mixture in conditions such that any sultones which have been formed in the reaction are hydrolyzed to give the corresponding hydroxy-alkanesulfonates. The sulfur trioxide may be liquid or gaseous, and is usually, but not necessarily, diluted by inert diluents, for example by liquid S chlorinated hydrocarbon, etc., when used in the liquid form, or by air, nitrogen, gaseous S0 etc., when used in the gaseous form.

The a-Olefins from which the olefin sulfonates are derived are mono-olefins having 12 to 24 carbon atoms, preferably 14 to 16 carbon atoms. Preferably, they are straight chain olefins. Examples of suitable l-olefins include l-dodecene; l-tetradecene; l-hexadecene; l-octadecene; l-eicosene and l-tetracosene.

In addition to the true alkene sulfonates and a proportion of hydroxy-alkanesulfonates, the olefin sulfonates can contain minor amounts of other materials, such as alkene disulfonates depending upon the reaction conditions, proportions of reactants, the nature of the starting olefins and impurities in the olefin stock and side reactions during the sulfonation process.

A specific anionic detergent which has also been found excellent for use in the present invention is described more fully in the US. Pat. 3,332,880 of Phillip F. Pfiaumer and Adriaan Kessler, issued July 25, 1967, titled Detergent Composition, the disclosure of which is herein incorporated by reference.

(B) Nonionic synthetic detergents Nonionic synthetic detergents may be broadly defined as compounds produced by the condensation of alkylene 8 oxide groups (hydrophilic in nature) with an organic hydrophobic compound, which may be aliphatic or alkyl aromatic in nature. The length of the hydrophilic or polyoxyalkylene radical which is condensed with any particular hydrophobic group can be readily adjusted to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements.

For example, a well known class of nonionic synthetic detergents is made available on the market under the trade name of Pluronic. These compounds are formed by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol. The hydrophobic portion of the molecule which, of course, exhibits water insolubility, has a molecular weight of from about 1500 to 1800. The addition of polyoxyethylene radicals to this hydrophobic portion tends to increase the water solubility of the molecule as a whole and the liquid character of the product is retained up to the point where polyoxyethylene content is about of the total weight of the condensation product.

Other suitable nonionic synthetic detergents include:

(1) The polyethylene oxide condensates of alkyl phenols, e.g., the condensation products of alkyl phenols having an alkyl group containing from about 6 to 12 carbon atoms in either a straight chain or branched chain configuration, with ethylene oxide, the said ethylene oxide being present in amounts equal to 5 to 25 moles of ethylene oxide per mole of alkyl phenol. The alkyl substituent in such compounds may be derived from polymerized propylene, diisobutylene, octene, or nonene, for example.

(2) Those derived from the condensation of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylene diamine. For example, compounds containing from about 40% to about polyoxyethylene by weight and having a molecular weight of from about 5,000 to about 11,000 resulting from the reaction of ethylene oxide groups with a hydrophobic base constituted of the reaction product of ethylene diamine and excess propylene oxide, said base having a molecular weight of the order of 2,500 and 3,000, are satisfactory.

(3) The condensation product of aliphatic alcohols having from 8 to 22 carbon atoms, in either straight chain or branched chain configuration, with ethylene oxide, e.g., a coconut alcohol-ethylene oxide condensate having from 5 to 30 moles of ethylene oxide per mole of coconut alcohol, the coconut alcohol fraction having from 10 to 14 carbon atoms.

(4) Nonionic detergents include nonyl phenol condensed with either about 10 or about 30 moles of ethylene oxide per mole of phenol and the condensation products of coconut alcohol with an average of either about 5.5 or about 15 moles of ethylene oxide per mole of alcohol and the condensation product of about 15 moles of ethylene oxide with one mole of tridecanol.

Other examples include dodecylphenol condensed with 12 moles of ethylene oxide per mole of phenol; dinonylphenol condensed with 15 moles of ethylene oxide per mole of phenol; dodecyl mercaptan condensed with 10 moles of ethylene oxide per mole of mercaptan; bis-(N-2- hydroxyethyl) lauramid; nonyl phenol condensed with 20 moles of ethylene oxide per mole of nonyl phenol; myristyl alcohol condensed with 10 moles of ethylene oxide per mole of myristyl alcohol; lauramide condensed with 15 moles of ethylene oxide per mole of lauramide; and di-isooctylphenol condensed with 15 moles of ethylene oxide.

(5) A detergent having the formula R R R N- O (amine oxide detergent) wherein R is an alkyl group containing from about 10 to about 28 carbon atoms, from 0 to about 2 hydroxy groups and from 0 to about 5 ether linkages, there being at least one moiety of R which is an alkyl group containing from about 10 to about 18 carbon atoms and 0 other linkages, and each R and R are selected from the group consisting of alkyl radicals and hydroxyalkyl radicals containing from 1 to about 3 carbon atoms;

Specific examples, of amine oxide detergents include: dimethyldodecylamine oxide, dimethyltetradecylamine oxide, ethylmethyltetradecylamine oxide, cetyldimethylamine oxide, dimethylstearylamine oxide, cetylethylpropylamine oxide, diethyldodecylamine oxide, diethyltetradecylamine oxide, dipropyldodecylamine oxide, bis-(2-hydroxyethyl) dodecylamine oxide, bis-(2-hydroxyethyl)-3-dodecoxyl-lhydroxypropylamine oxide, (2 hydroxypropyl)methyltetradecylamine oxide, dirnethyloleyamine oxide, dimethyl-(2-hydroxydodecyl)amine oxide, and the corresponding decyl, hexadecyl and octadecyl homologs of the above compounds.

(6) A detergent having the formula R R R P O (phosphine oxide detergent) wherein R is an alkyl group containing from about 10 to about 28 carbon atoms, from to about 2 hydroxy groups and from 0 to about 5 ether linkages, there being at least one moiety of R which is an alkyl group containing from about to about 18 carbon atoms and O ether linkages, and each of R and R are selected from the group consisting of alkyl radicals and hydroxyalkyl radicals containing from 1 to about 3 carbon atoms.

Specific examples of the phosphine oxide detergents include: dimethyldodecylphosphine oxide, dimethyltetradecylphosphine oxide, ethylmethyltetradecylphosphine oxide, cetyldirnethylphosphine oxide, dimethylstearylphosphine oxide, cetylethylpropylphosphine oxide, diethyldodecylphosphine oxide, diethyltetradecylphosphine oxide, dipropyldodecylphosphine oxide, bis (hydroxymethyl)dodecylphosphine oxide, bis-(2-hydroxyethyl)dodecylphosphine oxide, (2 hydroxypropyl)methyltetradecylphosphine oxide, dimethyloleylphosphine oxide, and dimethyl-(2-hydroxydodecyl)phosphine oxide and the corresponding decyl, hexadecyl, and octadecyl homologsof the above compounds.

(7) A detergent having the formula 0 E i-R (sulfoxide detergent) wherein R is an alkyl radical containing from about 10 to about 28 carbon atoms, from 0 to about 5 ether linkages and from 0 to about 2 hydoxy substituents at least one moiety of R being an alkyl radical containing 0 ether linkages and containing from about 10 to about 18 can-bon atoms, and wherein R is an alkyl radical containing from 1 to 3 carbon atoms and from one to two hydroxyl groups: octadecyl methyl sulfoxide, dodecyl methyl sulfoxide, tetradecyl methyl sulfoxide, 3-hydroxytridecyl methyl sulfoxide, 3-methoxytridecyl methyl sulfoxide, 3-hydroxy-4-dodecoxybutyl methyl sulfoxide, octadecyl 2-hydroxyethyl sulfoxide, dodecylethyl sulfoxide.

(C) Ampholytic synthetic detergents Ampholytic synthetic detergents can be broadly described as derivatives of aliphatic or aliphatic derivatives of heterocyclic secondary and tertiary amines, in which the aliphatic radical may be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to 18 carbon atoms and at least One contains an anionic water-solubilizing group, e.g., carboxy, sulfo, sulfato.

Examples of compounds falling within this definition are:

sodium-3- (dodecylamino -propionate,

sodium 3-(dodecylamino)propane-l-sulfonate,

sodium 2-(dodecylamino)ethyl sulfate,

sodium 2-(dimethylamino)octadecanoate,

disodium 3-(N-carboxymethyldodecylamino)-propanel-sulfonate, I

disodium octadecyl-iminodiacetate,

sodium 1-carboxymethyl-2-undecylimidazole, and

sodium N,N-bis(2-hydroxyethyl-2-sulfato-3-dodecoxypropylamine.

(D) Zwitterionic synthetic detergents Zwitterionic synthetic detergents can be broadly described as derivatives of alphatic quaternary ammonium and phosphonium or tertiary sulfonium compounds, in which the cationic atom may be part of a heterocyclic ring, and in which the aliphatic radical may be straight chain or branched, and wherein one of the aliphatic substituents contains from about 3 to 18 carbon atoms, and at least one aliphatic substituent contains an anionic water-solubilizing group, e.g., carboxy, sulfo, sulfato, phosphato, or phosphono. Examples of compounds falling within this definition are:

3- (N,N-dimethyl-N-hexadecyl-ammonio) 2-hydroxypropanel-sulfonate,

3-(N,N-dimethyl-N-hexadecylammonio)propane-1- sulfonate,

2- (N,N-dimethylN-dodecylammonio) acetate,

3- (N,N-dimethyl N-dodecylammonio propionate,

2- N,N-dimethyl-N-octadecylammonio ethyl sulfate,

2- (trimethylammonio ethyl dedecylphosphonate,

ethyl 3- N,N-dimethyl-N- do decylammonio propylphosphonate,

3- (P,P-dimethyl-P-dodecylphosphonio)propane-1- sulfonate,

2- (S-methyl-S-tert-hcxadecyl-sulfonio ethanel-sulfonate,

3- S-methyl-Sdodecylsulfonio) propionate,

sodium 2- N,N-dimethyl-N-dodecylammonio) ethyl phosphonate, I

4- S-methyl-S-tetradecylsulfonio butyrate,

1- 2-hydroxyethyl -2-undecylimidazoliuml-acetate,

2- (trimethylammonio octadecanoate, and

3-(N,N-bis- (2-hydroxyethy1)-N-octadecylammonio)- 2-hydroxypropane-1-sulfonate.

Some of these detergents are described in the following U.S. patents: 2,129,264; 2,178,353; 2,774,786; 2,813,898; and 2,828,332.

Examples of suitable water-soluble, inorganic alkaline detergency builder salts are alkali metal carbonates, b0- rates, phosphates, polyphosphates, bicarbonates, silicates and sulfates. Specific examples of such salts are sodium and potassium tetraborates, perborates, bicarbonates, carbonates, tripolyphosphates, pyrophosphates, orthophosphates and hexametaphosphates.

Examples of suitable organic alkaline detergency builder salts are: (l) Water-soluble salts of phytic acid, e.g., sodium and potassium phytatessee U.S. Pat. 2,739,942; (2) water-soluble, polyphosplronates, including specifically, sodium, potassium and lithium salts of ethane-1- hydroxy-l, l-diphosphonic acid, sodium, potassium and lithium salts of methylene diphosphonic acid, sodium, potassium and lithium salts of ethylene diphosphonic acid, and sodium, potassium and lithium salts of ethane-1,1,2-

triphosphonic acid. Other examples include the alkali metal salts of ethane-Z-carboxy-l,l-diphosphonic acid, hydroxymethanediphosphonic acid, carbonyldiphosphonic acid, ethane-l-hydroxy-1,1,2-triphosphonic acid, ethane-2- hydroxy-l,1,2-triphosphonic acid, propane-l,l,3,3-tetraphosphonic acid, propane-1,l,2,3-tetraphosphonic acid, and propane-1,2,2,3-tetraphosphonic acid; (3) water-soluble salts of polycarboxylate polymers and copolymers as described in U.S. Pat. No. 3,308,067. Specifically, a detergent builder material comprising a water-soluble salt of a polymeric aliphatic polycarboxylic acid having the following structural relationships as to the position of the carboxylate groups and possessing the following prescribed physical characteristics: (a) a minimum molecular weight of about 350 calculated as to the acid form; (b) an equivalent Weight of about 50 to about calculated as to acid form; (c) at least 45 mole percent of the monomeric species having at least two carboxyl radicals separated from each other by not more than two carbon atoms; (d) the site of attachment of the polymer chain of any car boxyl-containing radical being separated by not more than three carbon atoms along the polymer chain from the site of attachment of the next carboxyl-containing radical. Specific examples are polymers of itaconic acid, aconitic acid, maleic acid, mesaconic acid, fumaric acid, methylene malonic acid, and citraconic acid and copolymers with themselves and other compatible monomers such as ethylene; (4) Water-soluble salts of polycarboxylate polymers not included in (3) such as polyacrylates, polyisobutylene/ maleates, and polyacrylamide/acrylates; (5) water-soluble salts of polycarboxylates as described in US. Pats. 2,264,103 and 2,311,008; and (6) mixtures thereof.

Mixtures of organic and/or inorganic builders can be used and are generally desirable. One such mixture of builder-s is disclosed in US. Pat. 3,392,121, e.g., ternary mixtures of sodium tripolyphosphate, sodium nitrilotriacetate and trisodium ethane-l-hydroxy-l, l-diphosphomate. The above described builders can also be utilized singly in this invention.

In addition, other builders can be used satisfactorily such as water-soluble salts of mellitic acid, citric acid, pyromellitic acid, benzene pentacarboxylic acid, oxydiacetic acid, oxydissuccinic acid.

The builders preferably employed with the whiteness maintenance additive of this invention are the polymaleates having a molecular weight of from 350 to 600,000 preferably from 450 to 60,000, tripolyphosphates, pyrophosphates and carbonates. The water-soluble salts of the above polymaleates are most preferred.

The finished detergent formulation of this invention can also have included therein minor amounts of materials often included in detergent composition. Examples of such additives are tarnish inhibitors such as benzotriazole or ethylene thiourea, fluorescers, perfumes, coloring matter, enzymes, brightening agents, and bleaching agents.

The examples to follow are given to illustrate the invention. Unless otherwise indicated all percentages are by weight on a dry basis.

The detergent additive compositions of this invention were tested for whiteness maintenance by the following test procedures. A standard Tergotometer tub, Model 7243, was filled with 1 liter 140 F. water having a calcium hardness content of 7 grain/ gal. A built detergent composition was then added to the Tergotometer. The pH of this solution was next adjusted to 10.5. Thereafter a simulated soil component was added. This simulated soil comprised olive oil, oleic acid, mineral oil and air-borne soil components removed from the filter of an air-conditioning unit. The resulting mixture was then agitated for two minutes at a speed of 80 cycles per minute. After the above two minutes of agitation five 6" x 6" cotton terry cloths were added and washed for about 10 minutes. The washed cloths were then rinsed in 1 liter of 7 grain water for two minutes, run through a clothes wringer, rinsed a second time in 1 liter of 7 grain water for two minutes and again run through a clothes wringer. They were then tumble-dried. This procedure was repeated three times to give a total of four washings after which the terry cloths were graded.

The grading of the terry cloths for whiteness maintenance was done by way of two testsa test that recorded a whiteness value and a test that measured calcium salt deposition. The test that measured the amount of calcium salt deposited on the terry cloths was done by means of x-ray spectroscopy. The results obtained were in terms of parts per million (p.p.m.) of calcium deposited. The

greater the amount of calcium salt deposited, the greater was the adverse effect on the loss in whiteness maintenance of the washed cloths.

The other test used to measure the whiteness maintenance property of the compositions of this invention employed a Hunter color and color difference meter (Model D25, manufactured by Hunter Associates Labs, Inc.). This instrument numerically measures the degree of lightness and red-green and yellow-blue tints in the cloths on three different scales, namely the L, a, and b scale, respectively. The readings so obtained were converted into a whiteness value by means of the formula The greater the value of W, the greater the degree of whiteness maintenance. As use herein the values were obtained using five thicknesses of cloths and a ceramic tile (Suntile #54, whiteness=86.2) as backing for the terry cloths. The cloths being measured were placed on the top of the aforementioned five thicknesses prior to obtaining any readings. This was done to prevent the Suntile backing from affecting the readings.

The above two tests are necessary to fully evaluate the whiteness maintenance effect exhibited by the compositions of this invention. The whiteness value obtained from the Hunter color and color difference meter above is not a sufiicient measure of the total deposited material on the cloth. In part, this is because the values obtained from it do not fully reflect the effect of the calcium deposition on the cloths since the calcium salts themselves in most cases are of a white shade. Thus, increased deposition of calcium on the cloths can counteract the greying effect of soil and materially aflect the values obtained from the Hunter color and color diflierence meter. Similarly, the measure of the amount of calcium deposited on the cloths alone is not a good measure of the whiteness maintenance property of the compositions of this invention since it does not reflect the amount of other components that is deposited along with water-insoluble calcium salts. These other components, i.e. redeposited soil affect the whiteness maintenance of the total detergent composition. However, results obtained from both of the aforementioned two tests when interpreted together accurately reflect the superior whiteness maintenance property of the compositions of this invention.

EXAMPLE I The tables labelled Calcium Deposition and Whiteness list values obtained from the respective tests. Wash solutions containing the builder sodium polymaleate (NaPMA) at concentrations of 0.012%, 0.020%, 0.024%, 0.028%, 0.032%, 0.036% and 0.060% were used for purposes of these tests. The NaPMA had an average molecular weight of 5000. Also included in each wash solution was 0.03% of the detergent sodium linear alkyl benzene sulfonate (LAS) with an average chain length of 11.4 carbon atoms. The second through fifth columns list the amount of sodium cellulose acetate sulfate (SCAS) of average molecular weight of about 100,000, degree of acetyl substitution of 2.0 and degree of sulfate substitution of 0.56 and/or the amount of the sodium salt of hydrolyzed poly(vinyl methylether/maleic anhydride) (PVMEM) of average molecular weight: 138,500 in parts per million (p.p.m.) of wash solution.

The above listed values for the whiteness readings obtained from the Hunter color and color difference meter indicate that over a wide percentage range of builder/detergent/SCAS compositions, the whiteness values were greater than the same values obtained from a builder/ detergent, i.e. SCAS-free composition. For example, at a NaPMA concentration of 0.020% the builder/detergent/ SCAS composition had a whiteness value of 92.9, while the builder/detergent composition had a significantly lower whiteness value of 92.2. This indicates that the SCAS does improve the appearance of the cloths washed with a detergent composition containing it. However, the calcium deposition test indicates that the same builder/ detergent/SCAS composition generally causes a greater amount of calcium salt to be deposited on the cloths than the SCAS-free compositions. Thus, at the same NaPMA concentration of 0.020%, the builder/detergent/ SCAS composition had a calcium deposition value of 690, significantly higher than the calcium deposition value of 620 obtained for the builder/detergent composition. As a result of this calcium salt deposition, the washed cloths began to take on a greyish appearance due to the deposited calcium salts and soil. The greyish appearance becomes more noticeable as the number of washings increases. Interpretation of the above test results indicate that while the addition of SCAS to a built detergent composition improves the whiteness value obtained from cloths washed therewith, it does not decrease or prevent the deposition of calcium salts. Consequently the overall effect is that the whiteness maintenance of a builder/detergent/SCAS composition is not fully satisfactory.

Comparison of the builder/detergent/PVMEM composition and builder/detergent compositions also indicate that the addition of PVMEM to a builder and detergent does not fully satisfactorily improve the composition with respect to whiteness maintenance. As can be seen from the above tables the PVMEM-containing compositions found in the fourth column of the Calcium Deposition Table did have less deposition of calcium salts on the terry cloths than did the builder/ detergent compositions. However, the whiteness values showed that the PVMEM-containing compositions of the fourth column exhibited lesser values than the builder and detergent only compositions. Thus, overall, the addition of the PVMEM only to the builder and detergent compositions did not satisfactorily improve fully the built detergent composition.

The compositions of this invention, however, i.e. the compositions represented in the last column perform better with respect to having less calcium salts deposited on the cloths and improved or, in some cases, maintained the whiteness values, over compositions containing no SCAS and PVMEM. Accordingly, based on the favorable results of both the calcium deposition and whiteness tests, the overall whiteness maintenance of a built detergent composition is significantly improved by the addi- 'tion thereto of the SCAS and PVMEM.

EXAMPLE II The following tests were run to show the synergetic results obtained from built detergent compositions containing a wide range of mixtures of cellulose sulfate ester and copolymers of a vinyl compound and maleic anhydride. The sodium cellulose sulfate had an average molecular weight of about 92,400 a degree of sulfate substitution of 0.35. The copolymer used in this example was the same copolymer as used in Example I.

The same test procedures and wash procedures described in Example I were used in this example. The table below lists the ratio of poly(vinylmethylether/maleic anhydride) (PVMEM) to sodium cellulose sulfate (SCS) in the first column and the percentage of built detergent composition that is made up of the PVMEM-SCS mixture is in the second column. The remaining part of the compositions consists of the PMA and LAS described in Example I at a PMA to LAS who of 4.5.

(PVMEM Calcium PVMEM: plus SOS) deposition SCS ratio percent; (p.p.m.) whiteness The above results show that the compositions of this invention, i.e. B, C, D, E and F all had relatively low calcium deposition values and high whiteness values. The net effect of these tests showed that the whiteness maintenance of the compositions of this invention were satisfactory.

While Composition G of the above tests exhibited results that are not substantially different from Composition B, it should be realized that the above values were based on samples washed only four times. Significantly more dramatic results are obtained as the number of washes is increased. The example immediately below illustrates the increasingly greater advantages of the present invention as the number of Washes increases.

EXAMPLE III This example shows the effect the number of washings has on the performance of a detergent composition. Two compositions were tested. Composition A falling within the ranges of this invention and Composition B falling outside the ranges. From the calcium depositon and whiteness values listed in the tables, it is apparent that the greater the number of washes, the greater was the amount of calcium salt deposited and the greater was the decrease in whiteness value. Thus, it can be seen in regard to Examples I and II that what at first may appear to be a small performance difference actually is very significant and becomes increasingly more important at the end of each successive set of washes. It also can be seen that the composition of this invention, i.e. Composition A exceeded the performance of Composition B after each Washing.

The washing and grading procedures used in this example were the same as used in Example I. The following composition were used Composition A Percent Sodium polymaleate (average molecular weight 15 Composition B Percent Sodium polymaleate (average molecular weight Sodium linear alkyl benzene sulfonate (average alkyl chain length=11.4) 50.8 Poly(vinylrnethylether/maleic anhydride (average molecular weight=138,500)

The ratio of the polymaleate and alkyl benzene sulfonate of the above compositions were included in each formulation at the same relative proportion. The same polymaleate/alkyl benzene sulfonate concentration in the wash solutions were used in this example as in Example I, i.e. 0.024%.

examples are illustrative of the present The following invention.

EXAMPLE V Parts Poly(vinylmethylether/maleic anhydride) (average molecular wt. 1,000,000) 200 Sodium cellulose sulfate (average molecular. wt.

=350,000 and degree of sulfate substitution: 1) 1 Sodium hydroxyethyl cellulose sulfate (average molecular Wt.=l,000,000 and degrees of sulfate and hydroxyethyl substitution=0.8 and 2.5, respectively) 1 EXAMPLE VIII Parts Poly(vinylmethylether/maleic anhydride) (average molecular weight=700,000) 1 Sodium cellulose sulfate (average molecular wt.

=600,000 and sulfate degree of substitution=0.5) 9

The detergent additive compositions of Examples IV through VIII can be usefully included in detergent compositions of any form, including solid, powder, granular, and liquid fmmlllations.

16 EXAMPLE IX Percent Poly(vinylethylether/maleic anhydride) (average molecular wt. ==5,000) Sodium methyl cellulose sulfate (average degree of sulfate and methyl substitution:0.2 and 2.5, respectively and molecular Wt.=l,000,000) 0.01 Sodium tripolyphosphate 60.0 Condensation product of 1 mole of tallow alcohol and 3 moles of ethylene oxide 6.0 Sodium sulfate 23.0 Sodium silicate 5.0 Water 2.99

EXAMPLE X Percent Poly(vinylbutylether/maleic anhydride) (average molecular wt.= 1,000,000) Sodium cellulose acetate sulfate (avg. sulfate and acetyl degree of substitution=0.4 and 0.5 respectively. Molecular wt.-=15,000) 10.8

Hexasodium salt of benzene hexacarboxylic acid 50.0

Sodium tallow soap 11.0 Sodium sulfate 17.0 Sodium silicate 7.0 Water 3.0

EXAMPLE XI Percent Poly (vinylrnethylether/maleic anhydride) (average molecular wt.=10,000) 0.080

Sodium hydroxyethyl cellulose sulfate (average degree of sulfate and hydroxethyl substitution :10, and 1.2, respectively and molecular wt.

=350,000) 0.020 Sodium polymaleate (average molecular wt.

:350) 5.0 Sodium beta-methoxy hexadecane sulfonate 50.0 Sodium sulfate 35.0 Water 9.9

What is claimed is:

1. A granular built detergent composition, consisting essentially of:

(a) from 5% to by weight of a water-soluble detergency builder salt;

(b) from 5% to 60% by Weight of a detergent selected from the group consisting of non-ionic, anionic, zwitterionic and ampholytic detergent; and

(c) from 0.1% to 20% by Weight of a mixture of the water-soluble salts of (i) a cellulose sulfate ester selected from the group consisting of cellulose acetate sulfate, cellulose sulfate, hydroxyethylcellulose sulfate, methylcellulose sulfate and hydroxypropylcellulose sulfate; and (ii) a copolymer of a vinyl compound of the formula CH =CHY, wherein Y represents a C alkyl ether radical, and maleic anhydride, in a weight ratio of cellulose ester to copolymer of from 1:300 to 9:1.

2. The built detergent composition of claim 1 wherein the weight ratio of cellulose ester to copolymer is from 1:90 to 3:1.

3. The built detergent composition of claim 1 wherein the mixture of the water-soluble salt of the cellulose ester and the copolymer of the vinyl compound and maleic anhydride is present in the composition in an amount of from 1% to 12% by weight of the total composition.

4. The built detergent composition of claim 1 wherein the copolymer has an average molecular weight of from 5,000 to 1,000,000.

5. The built detergent composition of claim 1 wherein the cellulose ester has a degree of sulfate substitution of from 0.2 to 1 and has an average molecular weight of from 15,000 to 1,000,000.

6. The built detergent composition of claim 1 wherein the cellulose ester has a nonionic substituent and. wherein 17 the degree of substitution of the nonionic substituent ranges up to 2.5.

7. The built detergent composition of claim 1 wherein the cellulose ester is sodium cellulose sulfate and wherein the copolymer is poly(vinylmethylether/maleic anhydride).

8. The built detergent composition of claim 1 wherein the cellulose ester is sodium cellulose acetate sulfate and wherein the copolymer is poly(vinylmethylether/maleic anhydride).

9. The built detergent composition of claim 1 wherein the water-soluble detergency builder salt and detergent are co-present in a builder salt-to-detergent weight ratio of from 1:10 to 10:1.

10. The built detergent composition of claim 1 wherein the water-soluble salt is a salt of polymaleic acid having an average molecular weight of from 350 to 600,000.

18 References Cited UNITED STATES PATENTS 3,254,028 5/1966 Wixon 252Dig. 15 3,144,412 8/1964 Inamorato 252Dig. 15 3,211,660 10/1965 Marion et al. 252Dig. 15 3,308,067 3/1969 Diehl 252Dig. 15 3,485,762 12/1969 Gower et al 252Dig. 15 3,235,505 2/1966 Turell 25289 FOREIGN PATENTS 545,126 8/1957 Canada 252Dig. 15

WILLIAM E. SCI-I'ULZ, Primary Examiner U.S. C1. X.R. 252Digest 15