EP0123423A2

EP0123423A2 - Detergent compositions, detergent liquors and method for their preparation

Info

Publication number: EP0123423A2
Application number: EP84301902A
Authority: EP
Inventors: John Pickles
Original assignee: Procter and Gamble Ltd; Procter and Gamble Co
Current assignee: Procter and Gamble Ltd; Procter and Gamble Co
Priority date: 1983-03-26
Filing date: 1984-03-21
Publication date: 1984-10-31
Anticipated expiration: 2004-03-21
Also published as: IE840721L; DE3485378D1; GR81844B; EP0123423A3; EP0123423B1; IE57882B1; JPS601297A; JPH064871B2

Abstract

Detergent compositions are provided comprising a ternary surfactant system composed of anionic, ethoxylated nonionic and glyceryl monoesters of C₈-C₁₄aliphatic acids together with a sequestering agent, the glyceryl monoester being present in an amount of at least 0.75% of the compositions. Wash liquors containing the compositions and methods of their preparation including the addition of additive products containing one or more of the components to a wash liquor containing the remainder are also disclosed.

Description

Field of the Invention

This invention relates to detergent compositions and wash liquors incorporating mixtures of surfactants intended to provide enhanced grease and oily soil removal from fabrics and is especially concerned with compositions incorporating surfactant mixtures comprising anionics, ethoxylated rnnionics and glyceryl monoesters of aliphatic monocarboxylic acids.

Background of the Invention

The formulation of cleaning compositions with mixtures of surfactants in order to obtain improved detergency or controlled suds formation is well known in the detergent art. More especially the blending of different surfactant types for this purpose is well understood and numerous mixtures e.g. of nonionic and anionic or zwitterionic surfactants or of anionic, nonionic and cationic surfactants have been disclosed. Typical examples of mixtures of the binary type are described in British Patent Nos. 1,399,966 and 1,453,043 and examples of ternary mixtures are provided by British Patent Nos. 2040986, 1,418,719, 873,214 and 641,297.
Combinations of anionic and nonionic, particularly ethoxylated nonionic surfactants place relatively few constraints on formulation i.e. they do not give rise to compatibility problems with other components of conventional detergent compositions. Furthermore, unless ethoxylated nonionic surfactants are present at levels in excess of 10% by weight of particulate compositions their processing does not call for unconventional measures in order to provide free flowing products.
However, surfactant combinations, including cationic materials, do give rise to difficulties both in formulation and in processing. The tendency of quaternary ammonium salts to react with anionic components of the formulation is well known and cationic salts containing one or more detergent length hydrocarbyl groups produce water insoluble complexes with anionic surfactants and anionic optical brighteners. Depending on the formulation, these complexes may or may not be kept in suspension in the wash solution and the effectiveness of the reactants is likely to be reduced.
The processing of compositions containing cationic materials is also less straightforward than for compositions in which these materials are not present. Aqueous liquid compositions are less phase stable, particularly when exposed to cyclical temperatures near to 0°C, and the incorporation of cationic materials in spray dried particulate compositions requires care in order to avoid degradation resulting from exposure to highly alkaline conditions during the drying step. Control of the impregnation of non woven sheet substrates with a substantially anhydrous molten dispersion of surfactants and other components, to provide laundry detergent additive products, is also affected by the viscosity increase resulting from the addition of cationic surfactants.
Some cationic surfactants are hygroscopic and products containing them tend to develop stickiness on storage because of the moisture pick up, causing flow problems with granular products and a tendency for sheet substrate products to adhere together.
Accordingly, whilst cationic surfactants confer a number of specific performance benefits on detergent compositions containing them, their high cost relative to other surfactant types and the formulation and processing constraints which their inclusion imposes, make it desirable that alternative means be found of providing such benefits.
It has now been found that glyceryl monoesters of CS-C14 aliphatic carboxylic acids, when used in combination with certain anionic and ethoxylated nonionic surfactants, can provide the same range of grease and oily soil removal benefits as were hitherto believed only to be attainable by compositions incorporating cationic surfactants.
Glyceryl monoesters of fatty acids are surfactants employed primarily as emulsifiers in the foods industry but their low solubility in water has limited their use in detergent compositions designed for use in aqueous media. British Patent No. 1,564,507 claims aqueous bath foam compositions comprising from 1 to 50% by weight of glycerol monoesters of C₈-C₁₄ fatty acids with from 5 to 50% by weight of anionic surfactants and discloses the use of 2-3% ethoxylated coconut monoethanolamide as an optional component in such compositions.
Japanese Patent Application No. 73500/73 discloses a liquid detergent composition comprising an N-longchain acylated amino acid salt and a fatty acid nonionic surfactant, which can be glyceryl monostearate, optionally in the presence of a sequestering agent such as EDTA, NTA or citrate. British Patent Application No. 2040983 teaches the use of glyceryl fatty esters as components of suds suppressing systems for detergent compositions, including anionic and nononic surfactants. The glyceryl esters are present at levels of from 0.2% to 0.4% by weight of the composition.
Glycerol monoesters of C₁₂-C₁₈ fatty acids have also been disclosed as components of dryer-added sheet substrate fabric softening compositions, examples of such disclosures being those in Murphy et al USP 4,000,340, Perez Zamora USP 3,632,396 and British Patent No. 1,571,527.
In spite of these disclosures, there does not appear to have been an appreciation in the prior art of the ability of glycerol monoesters of C₈-C₁₄ aliphatic carboxylic acids to provide, in combination with certain anionic and ethoxylated nonionic surfactants, superior grease and oily soil removal from fabrics.
Therefore, according to one aspect of the present invention there is provided a detergent composition adapted to provide greasy, oily stain removal from fabrics comprising

A) a surfactant system comprising from 5 to 40% by weight of the composition and composed of
- 1) an unethoxylated anionic surfactant;
- 2) an ethoxylated nonionic surfactant having an HLB in the range 9-15;
- 3) a glyceryl monoester of a C₈-C₁₄aliphatic carboxylic acid, the glyceryl ester being present in an amount of at least 0.50% by weight of the composition;
B) a sequestering agent in an amount of from 1 to 60% by weight of the composition ;
C) from 0% to 94% of other detergent ingredients.

Preferably the anionic surfactant is of the sulfonate or sulfate type and, in more preferred compositions, the ethoxylated nonionic is an ethoxylated primary C₁₀-C₁₅ alcohol or an ethoxylated C₆-C₁₂ alkyl phenol.
According to another aspect of the invention there is provided a laundry liquor comprising from 100 to 25,000 ppm more preferably from about 1,000 to about 5,000 ppm of a composition as above defined.
In accordance with a further aspect of the invention a method of forming a laundry liquor as above defined comprises adding an additive product comprising the glyceryl ester component of the surfactant mixture to a wash liquor comprising an aqueous solution of at least the anionic surfactant.

Detailed Description of the Invention

Detergent compositions in accordance with the present invention comprise a three component surfactant system and a sequestering agent.

The Surfactant System

This comprises from 5% to 40%, preferably from 7 to 20%, most preferably from 10 to 15% of'the composition and is composed of a mixture of unethoxylated anionic, ethoxylated nonionic and glyceryl ester nonionic surfactants.

The Anionic Surfactant

The anionic surfactant can subject to certain conditions, be any one or more of the materials used conventionally in laundry detergents. Suitable synthetic anionic surfactants are water-soluble salts of alkyl benzene sulfonates, alkyl sulfates, paraffin sulfonates, alpha-olefin sulfonates, alpha-sulpho-carboxylates and their esters, alkyl glyceryl ether sulfonates, fatty acid monoglyceride sulfates and sulfonates, 2-acyloxy alkane-l-sulfonates, and beta-alkyloxy alkane sulfonates. Alkyl polyethoxy ether sulfates and alkyl phenol poly ethoxy ether sulfates are not suitable as the sole anionic surfactant for the purposes of the present invention but may be included as part of a mixture of anionic surfactants in which the non-ethoxylated species form the major proportion i.e. >-50% by weight of the mixture.
A particularly suitable class of anionic surfactants includes water-soluble salts, particularly the alkali metal, ammonium and alkanolammonium salts or organic sulphuric reaction products having in their molecular structure an alkyl or alkaryl group containing from 8 to 22, especially from 10 to 20 carbon atoms and a sulphonic acid or sulphuric acid ester group. (Included in the term "alkyl" is the alkyl portion of acyl groups). Examples of this group of synthetic detergents which form part of the detergent compositions of the present invention are the sodium and potassium alkyl sulfates, especially those obtained by sulphating the higher alcohols (C_8-18) carbon atoms produced by reducing the glycerides of tallow or coconut oil and sodium and potassium alkyl benzene sulfonates, in which the alkyl group contains from 9 to 15, especially 11 to 13, carbon atoms, in straight chain or branched chain configuration, e.g. those of the type described in U.S.P. 2,220,099 and 2,477,383 and those prepared from alkylbenzenes obtained by alkylation with straight chain chloroparaffins (using aluminium trichloride catalysis) or straight chain olefins (using hydrogen fluoride catalysis). Especially valuable are linear straight chain alkyl benzene sulfonates in which the average of the alkyl group is 11.8 carbon atoms, abbreviated as C_11.8LAS, and C₁₂-C₁₅ methyl branched alkyl sulfates.
Other anionic detergent compounds herein include the sodium C_10-18 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; the water-soluble salts or esters of alpha-sulfonated fatty acids containing from 6 to 20 carbon atoms in the fatty acid group and from 1 to 10 carbon atoms in the ester group; water-soluble salts of 2-acyloxy-alkane-l-sulphonic acids containing from 2 to 9 carbon atoms in the acyl group and from 9 to 23 carbon atoms in the alkane moiety; water-soluble salts of olefin sulfonates containing from 12 to 24, preferably 14 to 16, carbon atoms, especially those made by reaction with sulphur trioxide followed by neutralization under conditions such that any sultones present are hydrolysed to the corresponding hydroxy alkane sulfonates; water-soluble salts of paraffin sulfonates containing from 8 to 24, especially 14 to 18 carbon atoms, and beta-alkyloxy alkane sulfonates containing from 1 to 3 carbon atoms in the alkyl group and from 8 to 20 carbon atoms in the alkane moiety.
Ethoxylated anionic surfactants, that can be used in admixture with the foregoing compounds so as to form a minoir proportion of the mixture, include alkyl ether sulfates containing from 10 to 18, especially from 12 to 16, carbon atoms in the alkyl group and from 1 to 12, especially from 1 to 6, more especially from 1 to 4 moles of ethylene oxide; and sodium or potassium salts of alkyl phenol ethylene oxide ether sulfates containing 1 to 10 units of ethylene oxide per molecule and Wherein the alkyl groups contain 8 to 12 carbon atoms.
The alkane chains of the foregoing non-soap anionic surfactants can be derived from natural sources such as coconut oil or tallow, or can be made synthetically as for example using the Ziegler or Oxo processes. Water solubility can be achieved by using alkali metal, ammonium or alkanolammonium cations; sodium is preferred. Suitable fatty acid soaps can be selected from the ordinary alkali metal (sodium, potassium), ammonium, and alkylolammonium salts of higher fatty acids containing from 8 to 24, preferably from 10 to 22 and especially from 16 to 22 carbon atoms in the alkyl chain. Suitable fatty acids can be obtained from natural sources such as, for instance, from 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 tallow and hydrogenated fish oil.
In preferred surfactant systems the anionic surfactants should contain no ethoxylated species as unethoxylated surfactants show superior grease and oily soil removal capability. Preferably also the surfactants are of the sulfonate or sulfate type and mixtures of anionic surfactants are particularly suitable herein, especially mixtures of sulfonate and sulfate surfactants in a weight ratio of from 10:1 to 1:5, preferably from 5:1 to 1:1.5, more preferably from 5:1 to 1:1. Especially preferred is a mixture of an alkyl benzene sulfonate having from 9 to 15, especially from 11 to 13 carbon atoms in the alkyl radical, the cation being an alkali metal, preferably sodium; and an alkyl sulfate having from 10 to 20, preferably from 12 to 18 carbon atoms in the alkyl radical.

The Ethoxylated Nonionic Surfactant

The ncnionic surfactants useful in the present invention are condensates of ethylene oxide with a hydrophobic moiety to provide a surfactant having an average hydrcphilic-lipophilic balance (HLB) in the range from 9 to 15, preferably from 9.5 to 13.5, more preferably from 10 to 12.5. The hydrophobic moiety may be aliphatic or aromatic in nature and the length of the polyoxyethylene group 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.
Examples of suitable ncnionic surfactants include:

1. The polyethylene oxide condensates of alkyl phenol, e.g. the condensation products of alkyl phenols having an alkyl group containing from 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 3 to 20, preferably 5 to 14 moles of ethylene oxide per mole of alkyl phenol. The alkyl substituent in such compounds may be derived, for example, from polymerised propylene, di-isobutylene, octene and nonene. Other examples include dodecylphenol condensed with 9 moles of ethylene oxide per mole of phenol; dinonylphenol condensed with 11 moles of ethylene oxide per mole of phenol; nonylphenol and di-isooctylphenol condensed with 13 moles of ethylene oxide.
2. The condensation product of primary or secondary aliphatic alcohols having from 8 to 24 carbon atoms, in either straight chain or branched chain configuration, with from 2 to 15 moles, preferably from 2 to 9 moles of ethylene oxide per mole of alcohol. Preferably, the aliphatic alcohol comprises between 9 and 18 carbon atoms and is ethoxylated with between 2 and 9, desirably between 3 and 8 moles of ethylene oxide per mole of aliphatic alcohol. The preferred surfactants are prepared from primary alcohols which are either linear (such as those derived from natural fats or prepared by the Ziegler process fran ethylene, e.g. myristyl, cetyl, stearyl alcohols), or partly branched such as the Lutensols, Dobanols and Neodols which have 25% 2-methyl branching (Lutensol being a Trade Name of BASF, Ebbanol and Neodol being Trade Names of Shell), or Synperonics, which are understood to have 50% 2-methyl branching (Synperonic is a Trade Name of I.C.I.) or the primary alcohols having more than 50% branched chain structure sold under the Trade Name Lial by Liquichimica. Specific examples of nonionic surfactants falling within the scope of the invention include Dobanol 45-4, Dobanol 45-7, Dobanol 45-9, Dobanol 91-2.5, Dobanol 91-3, Dobanol 91-4, Dobanol 91-6, D_Obanol 91-8, Dobanol 23-6.5, Synperonic 6, Synperonic 14, the condensation products of coconut alcohol with an average of between 5 and 12 moles of ethylene oxide per mole of alcohol, the coconut alkyl portion having from 10 to 14 carbon atoms, and the condensation products of tallow alcohol with an average of between 7 and 12 moles of ethylene oxide per mole of alcohol, the tallow portion comprising essentially between 16 and 22 carbon atoms. Secondary linear alkyl ethoxylates are also suitable in the present compositions, especially those ethoxylates of the Tergitol series having from 9 to 15 carbon atoms in the alkyl group and up to 11, especially from 3 to 9, ethoxy residues per molecule.
3. The compounds formed by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with prcpylene glycol. The molecular weight of the hydrophobic portion generally falls in the range of 1500 to 1800. Such synthetic nonionic detergents are available on the market under the Trade Name of "Pluronic" supplied by Wyandotte Chemicals Corporation.

Especially preferred nonionic surfactants for use herein are the C₉-C₁₅ primary and secondary alcohol ethoxylates containing 3-8 moles of ethylene oxide per mole of alcohol, particularly the C₁₂-C₁₅ primary alcohols containing 6-8 moles of ethylene oxide per mole of alcohol.

The Glyceryl Ester Surfactant

The glyceryl esters useful in the present invention are the monoesters of C₈-C₁₄ aliphatic carboxylic acids, particularly the monoesters of C₁₀-C₁₄ aliphatic carboxylic acids. The carboxylic acids may be derived from natural sources i.e. vegetable oils or animal fats, or may be synthetic in origin i.e. from olefin build up or OXO synthesis. Accordingly, the aliphatic group may be saturated or unsaturated in type and linear or branched in structure. Preferably the aliphatic carboxylic acids are linear or predominantly linear in structure and are fully saturated.
Preferred materials are glyceryl monocaprate, glyceryl monolaurate and glyceryl monomyristate although glyceryl mono esters of blends of C₁₀, C₁₂ and C₁₄ carboxylic acids are also suitable for the purposes of the invention. Commercial grades of glyceryl monolaurate and glyceryl monomyristate are particularly preferred as their waxy physical characteristics and melting point range (50-70°C) make them useful binder materials for the prilled form of chemically labile detergent components such as bleach activators. It will be understand that the glyceryl esters will also contain low levels of C₈ and C₁₆₊ esters arising from the particular source of the aliphatic carboxylic acid.
The preparation of glyceryl monoesters is well known in the art, and is conventionally carried out by means of a two stage process involving partial glycerolysis of fats or oils followed by nolecular distillation. Although it is preferred that the monoester comprises at least 90%, most preferably at least 95% by weight of the glyceryl ester component, esters of monoester content ≥ 70% can be used in which the major portion of the remainder is usually the diester together with minor proportions of glycerol and fatty acid. The level of tri ester (i.e. the starting fat or oil) should be minimised and should not exceed 1% by weight of the ester component as it constitutes a cleaning load. Separation of the desired monoester or monoester fraction from the saponification reaction mixture is normally carried out by means of vacuum distillation.
In the case of the shorter chain length (C₈-C₁₀) fatty monoester materials it may be more convenient to esterify the glycerol with the appropriate acid. This technique also has to be used where synthetically derived fatty acids are employed in the monoester synthesis.
In order to provide the grease and oily soil removal benefits obtainable with detergent compositions in accordance with the invention, the glyceryl ester surfactant must be present in an amount of at least 0.5%, preferably at least 0.7% and normally at least 1.0% by weight. Most preferably the glyceryl ester is present in an amount of at least 2% by weight of the composition.
Preferred surfactant systems, in accordance with the invention, employ a ratio of anionic surfactant to glyceryl ester of ≤ 15:1 by weight, more normally ≤ 10:1 and most commonly ≤ 6:1.
The surfactant system will normally comprise, by weight of the system, from 30 to 80% more preferably from 50 to 70% anionic, from 12 to 60% ethoxylated more preferably from 20 to 40% nonionic and from 2.5 to 30% more preferably from 10 to 25% glyceryl ester, with the proviso that the amount of glyceryl ester will always be at least 0.50% by weight of the composition.
The other essential component of detergent compositions in accordance with the invention is a sequestering agent, present in an amount of from 1 to 60%, more usually from 5 to 50% by weight of the composition. The sequestering agents can be either organic or inorganic in form and may be water soluble or water insoluble in character.
Suitable inorganic builder salts include orthophosphates, pyrophosphates, tripolyphophates and the higher polymeric glassy phosphates, silicates, carbonates, and the water insoluble crystalline aluminosilicates such as hydrated Zeolite A, X or P.
Organic sequestering agents that can be incorporated include the aminocarboxylates such as the salts of nitrilotriacetic acid (NTA), ethylenediaminetetra acetic acid (EDTA) and diethylenetriaminepenta acetic acid (DETPA) and the methylene phosphonate analogues of these materials NTMP, EDTMP and DETPMP, as well as the salts of polycarboxylic acids such as lactic acid, glycollic acid and ether derivatives thereof as disclosed in Belgian Patents 821,368, 821,369 and 821,370; succinic acid, malonic acid, (ethylenedioxy) diacetic acid, maleic acid, diglycollic acid, tartaric acid, tartronic acid and fumaric acid; citric acid, aconitic acid, citraconic acid, carboxymethyloxysuccinic acid, lactoxysuccinic acid, and 2-oxy-1,1,3-propane tri-carboxylic acid; oxydisuccinic acid, 1,1,2,2-ethane tetracarboxylic acid, 1,1,3,3-propene tetracarboxylic acid and 1,1,2,3-propane tetracarboxylic acid; cyclo-pentane-cis, cis, cis-tetracarboxylic acid; cyclopentadienide pentacarboxylic acid, 2,3,4,5-tetrahydrofuran-cis, cis, cis-tetracarboxylic acid, 2,5-tetrahydrofuran-cis- dicarboxylic acid, 1,2,3,4,5,6-hexane-hexacarboxylic acid, mellitic acid, pyromellitic acid and the phthalic acid derivatives disclosed in British Patent 1,425,343.
Polymeric organic sequestering agents can also be used, such as copolymeric polycarboxylic acids which comprise at least two carboxyl radicals separated from each other by not more than two carbon atoms and which has an average molecular weight in the range from 500 to 2,000,000, more preferably from 12,000 to 1,500,000 comprises:

(a) polycarboxylic acid units having the general formula
wherein X, Y, and Z are each selected from the group consisting of hydrogen, methyl, aryl, alkaryl, carboxyl, hydroxy and carboxymethyl; at least one of X, Y, and Z being selected from the group consisting of carboxyl and carboxymethyl, provided that X and Y can be carboxymethyl only when Z is selected from carboxyl and carboxymethyl and wherein only one of X, Y, and Z can be methyl, aryl, hydroxyl and alkaryl, and
(b) monomer units selected from
wherein R₁ is a C₁ to C₁₂ alkyl group or a ^C ₁ to ^C ₁₂ acyl group, R₁ optionally being hydroxy substituted,
wherein R₂ is H or CH₃ and R₃ is H, or a C₁ to C₁₀ alkyl group, R₂, R₃ optionally being hydroxy substituted,
wherein each of R₄ to R₇ is H or an alkyl groups such that R₄ to R₇ together have from 1 to 20 carbon atoms, R₄-R₇ each optionally being hydroxy substituted, and
in which R₈ is benzyl or pyrrolidone.

Highly preferred examples of such carboxylates are 1:1 styrene/maleic acid copolymer, di-isobutylene/maleic acid copolymers, methyl vinyl ether/maleic acid copolymers and maleic acid; acrylic acid copolymers having a molar ratio between 1:1 and 1:4. Other suitable polycarboxylates are poly-alpha-hydroxy acrylates and lactones thereof as described in Belgian Patent 817,678 and B.P. 1,425,307.
The above described inorganic and organic sequestering agents can be used in combination in order to ensure sequestration of each metal ion that influences detergency. An example of such a combination would be the use of an insoluble zeolite primarily for calcium, a polycarboxylate primarily for magnesium, and an amino polyphosphonate primarily for heavy metal ions.

Optional Components

The compositions of the present invention can be supplemented by a wide range of optional components.
The principal optional component which is a highly preferred ingredient of the compositions is an inorganic peroxygen bleach of the perhydrate type, defined for the purposes of this invention as having hydrogen peroxide associated with the molecule. Alkali metal perborates, percarbonates, persilicates and perpyrophosphates are examples of such bleaches. They are normally included at levels of from 5% to 35% by weight, preferably from 15% to 25% by weight of the composition, so as to provide from 50 to 7000 ppm, preferably from 300 to 2000 ppm of bleach in the laundry liquor.
Preferred perhydrates are sodium perborate mono- and tetrahydrate and sodium percarbonate. Sodium perborate is the most preferred perhydrate as the addition of this material to compositions according to the invention provides an enhancement of their grease and oily soil removal capability.
A highly preferred optional component of compositions in accordance with the invention is an organic peroxyacid bleach precursor, a so-called bleach activator. Compounds of this type are well known in the detergent art, exemplary disclosures being provided in British Patent Nos. 836,988, 864,798, 1,586,769, 2040893 and European Patent Application Publication No. 0062523. Highly preferred precursors include tetraacetyl ethylene diamine, tetra acetyl methylene diamine, tetraacetylglycouril, sodium p-acetoxybenzene sulfonate, sodium p-C₇-C₉ acyloxybenzene sulfonate, penta acetyl glucose and octa acetyl lactose. The precursors are incorporated so as to provide from 2 to 50 ppm of available oxygen from the peroxy acid in the wash liquor and normally are present in an amount such that the inorganic perhydrate to precursor molar ratio is at least 1.5:1, preferably at least 2:1 and normally in the range from 3:1 to 12:1.
Soil suspending and antiredeposition agents are also preferred components of the compositions of the invention at levels of from 0.1% to 10% by weight. Methyl cellulose and its derivatives such as water-soluble salts of carboxymethylcellulose, carboxyhydroxymethyl cellulose and polyethylene glycols having a molecular weight of from 400 to 10,000 are common components of the present invention. Certain organic polymeric materials such as maleic anhydride-methyl vinyl ether and maleic anhydride-ethylene copolymers of Mwt 25,000 are also useful in this function.
Enzymes in minor amounts are conventional ingredients of the compositions, those suitable for use including the materials discussed in U.S. patents 3,519,570 and 3,533,139 to McCarty and McCarty et al.
Anionic fluorescent brightening agents are well-known ingredients, examples of which are disodium 4,4'-bis-(2-di- ethanolamino-4-anilino-s-triazin-6-ylamino)stilbene-2:2'- disulfonate, disodium 4,4'-bis-(2--morpholino-4-anilino-s-triazin-6-ylaminostilbene-2:2'-disulfonate, disodium 4'4-bis-(2,4-dianilino-s-triazin-6-ylamino)stilbene-2:2'- disulfonate, disodium 4,4'-bis-(2-anilino-4-(N-methyl N-2-hydroxyethylamino)-S-triazin-6-ylamino)stilbene-2,2' - disulfonate, disodium 4,4'-bis-(4-phenyl-2,l,3-triazol-2yl) -stilbene-2,2'-disulfonate, disodium 4,4¹;-bis-(2-anilino-4-(1-methyl-2-hydroxyethylamino)-S-triazin-6-ylamino) stilbene -2,2'-disulfonate and sodium 2(stilbyl-4''-(naphtho-1',2':4, 5)-1,2,3-triazole-2"-sulfonate.
The present compositions also preferably contain suds regulating components in an amount of from 0.05% to 3%. Preferred are silicone fluids and also microcrystalline waxes having a melting point in the range from 35°C to 115°C and saponification value of less than 100. The microcrystalline waxes are substantially water-insoluble, but are water-dispersible in the presence of organic surfactants. Preferred microcrystalline waxes having a melting point from 65°C to 100°C, a molecular weight in the range from 400-1000; and a penetration value of at least 6, measured at 77°C by ASTM-D1321. Suitable examples of the above waxes include microcrystalline and oxidized micro-crystalline petrolatum waxes; Fischer-Tropsch and oxidized Fischer-Tropsch waxes; ozokerite; ceresin; montan wax; beeswax, candelilla; and carnauba wax.
U.S. Patent 3,933,672 issued January 20 1976, to Bartollota et al. discloses silicone suds controlling agents suitable herein. The silicone material can be represented by alkylated polysiloxane materials such as silica aerogels and xerogels and hydrophobic silicas of various types. The silicone material can be described as siloxane having the formula:
wherein x is from 20 to 2,000 and R and R' are each alkyl or aryl groups, especially methyl, ethyl, propyl, butyl and phenyl. The polydimethylsiloxanes (R and R' are methyl) having a molecular weight within the range of from 200 to 2,000,000, and higher, are all useful as suds controlling agents. Additional suitable silicone materials wherein the side chain groups R and R' are alkyl, aryl, or mixed alkyl or aryl hydrocarbyl groups exhibit useful suds controlling properties. Examples of the like ingredients include diethyl-, dipropyl-, dibutyl-, methyl-, ethyl-, phenyl-, methylpolysiloxanes and the like. Additional useful silicone suds controlling agents can be represented by a mixture of an alkylated siloxane, as referred to hereinbefore, and solid silica. Such mixtures are prepared by affixing the silicone to the surface of the solid silica. A preferred silicone suds controlling agent is represented by a hydrophobic silanated (most preferably trimethylsilanated) silica having a particle size in the range from 10 millimicrons to 20 millimicrons and a specific surface area above 50 m²/g. intimately admixed with dimethyl silicone fluid having a molecular weight in the range from 500 to 200,000 at a weight ratio of silicone to silanated silica of from 1:1 to 1:10. The silicone suds suppressing agent is advantageously releasably incorparated in a water-soluble or water-dispersible, substantially non-surface-active detergent-impermeable carrier.
Particularly useful suds suppressors are the self-emulsifying silicone suds suppressors, described in German Patent Application DTOS 2,646,126 published April 28, 1977. An example of such a compound is DB-544, commercially available from Dow Corning, which is a siloxane/glycol copolymer.
Where not included as a sequestering agent, a highly preferred ingredient of the detergent liquors and of compositions for their production, is a polyphosphonic acid or salt thereof in an amount from 0.01 to 4%, especially from 0.1 to 1.0% by weight. At this level of incorporation, which is below the range of levels normally employed for detergent builders, the polyphosphonic acid or salt thereof is found to provide bleachable stain detergency benefits.
Especially preferred polyphosphonates have the formula:-
wherein each R is CH₂PO₃H₂ or a water-soluble salt thereof and n is from 0 to 2. Examples of compounds within this class are aminotri-(methylenephosphonic acid), ethylene diamine tetra(methylenephosphonic acid) and diethylene triamine penta(methylene phosphonic acid). Of these, ethylenediamine tetra(methylene phosphonic acid) is particularly preferred.
Another suitable component of detergent compositions in accordance with the invention is a water-soluble magnesium salt which is added at levels in the range from 0.015% to 0.2%, preferably from 0.03% to 0.15% and more preferably from 0.05% to 0.12% by weight of the compositions (based on weight of magnesium). Suitable magnesium salts include magnesium sulfate, magnesium sulfate heptahydrate, magnesium chloride, magnesium chloride hexahydrate, magnesium fluoride and magnesium acetate.
Where the formulations are particulate in nature anticaking agents such as sodium sulfosuccinate or sodium benzoate can be included in varying amounts as desired. Aesthetic ingredients such as dyes, pigments, photo activated bleaches such as tri- and tetra-sulfonated zinc phthalo cyanine, and perfumes are also normal components of the compositions.
Detergent compositions, in accordance with the invention, can be solid or liquid and where they are solid can take any of the conventional forms, e.g. spray dried or agglomerated particles, bars or tablets. The glyceryl esters can be incorporated into spray dried granular compositions either as one of the components of the slurry which is spray dried to form the base powder or as a sprayed or prilled additive to the base granules. In general, addition to the spray dried base powder, together with the ethoxylated nonionic surfactant, is utilised in order to avoid saponification of the esters under the hot alkaline conditions encountered in the aqueous slurries from which the spray dried powders are formed.
In a preferred form of the invention in which an organic peroxy acid bleach precursor is included in the composition, ^- the glyceryl ester is employed as a binder medium for the formation of prills incorporating the bleach precursor.
These prills are typically of 1-1.5mm diameter and 4-10mm length and are formed by radial or axial extrusion e.g. by means of the technique disclosed in European Patent Publication No. 0062523. The prills are normally added as a dry mix component to the spray dried base powder.
Glyceryl monoesters such as glyceryl monolaurate and glyceryl mono-myristate are particularly useful in forming prills of branched chain C₇-C₉ peroxy acid precursors. Binder levels of from 10% to 25% by weight of the prills, i.e. precursor levels of from 75 to 90%, can be employed at prilling temperatures of 50° to 80°C in batch operation and 55° to 60°C under continuous operating conditions. In contrast, prills of branched chain C₇-C₉ peroxy acid precursors with conventional binders, such as tallow alcohol ethoxylates or polyethylene glycols, require binder levels of from 40 to 50% by weight and tend to discolour under the temperatures necessary to carry out the prilling process. Accordingly a particularly preferred embodiment of the detergent composition aspect of the invention incorporates a C₁₀-C₁₄ glyceryl ester, such as glyceryl monolaurate, as the binder for a prill containing a C₇-C₉ peroxy acid precursor such as an alkali metal linear or branched chain C₇-Cg acyl oxybenzene sulphonate or acyl oxybenzoate.
According to another aspect of the invention, aqueous laundry liquors are provided comprising from 100 to 25,000, preferably from 1,000 to 15,000 ppm of the compositions as hereinbefore described and such liquors can be formed in the conventional manner by direct dissolution of the compositions into water to form the wash solution. However, in accordance with a further aspect of the invention, the liquors can also be formed by the addition of a laundry additive product incorporating some of the components of the present invention to a previously formed wash liquor containing the remainder.
Such laundry additive products can take a variety of physical forms, viz. liquids, particulate solids, tablets, pouches or sachets or impregnated sheet substrates.
Additive products in particulate substrate form can comprise powders, flakes, chips, tablets or noodles which may be used as-is or may themselves be enclosed in containers for addition to an aqueous liquor.
Typically, but not invariably, the aqueous wash liquor will already contain an anionic surfactant together with a sequestering agent and possibly some ethoxylated nonionic surfactant and the additive product will comprise the additional glyceryl ester component together with ethoxylated nonionic surfactant. In certain preferred executions, additive products may themselves constitute compositions in accordance with the invention although designed to be added to detergent liquors to provide a boost in detergency performance.
Additive products in accordance with this aspect of the present invention may comprise one or more of the components of the composition in combination with a carrier such as a compatible particulate substrate, a flexible non particulate substrate or a container. Examples of compatible particulate substrates include inert materials such as clays and other aluminosilicates including zeolites both natural and synthetic in origin. Other compatible particular carrier materials include hydratable inorganic salts such as phosphates, carbonates and sulfates.
Additive products enclosed in bags or containers are manufactured such that the containers prevent egress of their cmtents when dry but are adapted to release their contents on immersion in an aqueous solution.
A convenient execution of this form of the additive product comprises a particulate solid composition enclosed in a container. Usually the container will be flexible, such as a bag or pouch. The bag may be of fibrous construction coated with a water impermeable protective material so as to retain the contents, such as is disclosed in European published Patent Application No. 0018678. Alternatively it may be formed of a water insoluble synthetic polymeric material provided with an edge seal or closure designed to rupture in aqueous media as disclosed in European published Patent Application Nos. 0011500, 0011501, 0011502, and 0011968. A convenient form of water frangible closure comprises a water soluble adhesive disposed along and sealing one edge of a pouch formed of a water impermeable polymeric film such as polyethylene or polypropylene.
An alternative form of the additive product comprises a composition in water releasable combination with a non particulate flexible substrate in a weight ratio of 1:10 to 30:1. Additive products of this type incorporating a peroxy acid bleach precursor are disclosed in British Patent Specification Nos. 1,586,769 and 2040983B and also in European Patent Application No. 0098129 and in European Patent Application No. 84301070.3.
The following discussion of the non particulate substrate additive product embodiment of this aspect of the invention embraces formulations from which one or more of the components of the present invention may be absent e.g. anionic and/or sequestering agent. In such cases, however, it is assumed that the missing components will be present in the wash liquor to which the product is added.
The substrate may itself be water soluble or water insoluble and in the latter case it should possess sufficient structural integrity under the conditions of the wash to be recovered from the machine at the end of the laundry cycle. Structures which are water disintegratable i.e. that break down in aqueous media to insoluble individual fibres or particles are not considered satisfactory for the purposes of the present invention.
Water soluble materials include certain cellulose ethers, alginates, polyvinyl alcohol and water soluble polyvinyl pyrrolidone polymers, which can be formed into non-woven and woven fibrous structures. Suitable water insoluble materials include, but are not restricted to, natural and synthetic fibres, foams, sponges and films.
The substrate may have any one of a number of physical forms such as sheets, blocks, rings, balls, rods or tubes. Such forms should be amenable to unit usage by the consumer, i.e. they should be capable of addition to the washing liquor in measured amounts, such as individual sheets, blocks or balls and unit lengths of rods or tubes. Certain of these substrate types can also be adapted for single or multiple uses, and can be provided with composition loadings up to a composition:substrate ratio of 30:1 by weight.
One such article comprises a sponge material releasably enclosing enough additives to permit its effective use during several washing cycles. This multi-use article can be made by impregnating a sponge ball or block with 20 grams of the additive composition. In use, the composition leaches out through the pores of the sponge into the wash liquor and can be used to treat several loads of fabrics in conventional washing machines, and has the advantage that it can remain in the washer after use.
A highly preferred execution of this type of additive product utilises a flexible sheet so as to make it compatible with the movement of the fabrics in the washing machine and to facilitate its handling during manufacture of the product. Preferably the sheet is water pervious i.e. water can pass from one surface of the sheet to the opposite surface and, for film type substrates, perforation of the sheet is desirable. The most preferred form of the substrate is a sheet of woven or non-woven fabric or a thin sheet of cellular plastics material. Woven fabric sheets can take the form of a plain weave natural or synthetic fibre of low fibre count/unit length, such as is used for surgical dressings, or of the type known as cheese cloth. Loading limitations on sheet type substrates limit the amount of composition that can be applied to the sheet and, in practice, the weight ratio of composition:sheet substrate normally lies within the range from 1:2 to 15:1.
As stated above, suitable materials which can be used as a substrate in the invention herein include, among others, sponges, paper, and woven and non-woven fabrics.
A suitable sponge like material that can be used in the present invention comprises an absorbent foam like material in the form of a sheet. The term 'absorbent foam-like material' is intended to encompass three dimensional absorptive materials such as 'gas blown foams', natural sponges and composite fibrous based structures such as are disclosed in US Patent Nos. 3311115 and 3430630. A particularly suitable material of this type is a hydrophilic polyurethane foam in which the internal cellular walls of the foam have been broken by reticulation. Foams of this type are described in detail in Dulle US Patent No. 3794029. A preferred example of this foam type comprises a hydrophilic polyurethane foam of density 0.596 grs per cubic inch with a cell count of between 8 and 40 cells per cm, preferably from 24 to 32 per cm available from the Scott Paper Company, Eddystone, Pennsylvania USA., under the Registered Trade Mark "Hydrofoam". Preferred sheets of this type of material have thicknesses in the range from 3 to 5 mm.
Preferred sheet substrates for use in this type of additive product are apertured and non apertured non woven fabrics which can generally be defined as adhesively bonded fibrous or filamentous products, having a web or carded fibre structure (where the fibre strength is suitable to allow carding) or comprising fibrous mats, in which the fibres or filaments are distributed haphazardly or in random array (i.e. an array of fibres in a carded web wherein partial orientation of the fibres is frequently present as well as a completely haphazard distributional orientation) or substantially aligned. The fibres or filaments can be natural (e.g. wool, silk, wood pulp, jute, hemp, cotton, linen, sisal, or ramie), synthetic (e.g. rayon, cellulose, ester, polyvinyl derivatives, polyolefins, polyamides, or polyesters) or mixtures of any of the above.
The choice of binder-resins used in the manufacture of non-woven cloths can provide substrates possessing a variety of desirable traits. For example, the absorbent capacity of the cloth can be increased, decreased, or regulated by respectively using a hydrophilic binder-resin, a hydrophobic binder-resin or a mixture thereof in the fibre bonding step. Moreover, the hydrophobic binder-resin, when used singly or as the predominant compound of a hydrophobic hydrophilic mixture, provides non-woven cloths which are especially useful as substrates when the additive products are used in an automatic washer.
When the substrate herein is a bonded non-woven cloth made from fibres, deposited haphazardly or in random array on the screen, the compositions exhibit excellent strength in all directions and are not prone to tear or separate when used in the washer.
Preferably, the non-woven cloth is water-laid or air-laid and is made from cellulosic fibres, particularly from regenerated cellulose or rayon, which are lubricated with standard textile lubricant. Preferably the fibres are from 4 to 50 mm in length and are from 1.5 to 5 denier (Denier is an internationally recognised unit in yarn measure, corresponding to the weight in grams of a 9,000 meter length of yarn). Preferably the fibres are at least partially orientated haphazardly, particularly substantially haphazardly, and are adhesively bonded together with hydrophobic or substantially hydrophobic binder-resin, particularly with a nonionic self-crosslinking acrylic polymer or polymers. Conveniently, the cloth comprises 70% fibre and 30% binder-resin polymer by weight and has a basis weight of from 10 to 100, preferably from 24 to 72 g/m .
Apertured non-woven substrates are also useful for the purposes of the present invention. The apertures, which extend between opposite surfaces of the substrate are normally in a pattern and are formed during lay-down of the fibres to produce the substrate. Exemplary apertured non-woven substrates are disclosed in US Patent Nos. 3,741,724, 3,930,086 and 3,750,237.
A suitable diamond patterned apertured substrate is obtainable from Chicopee Manufacturing C_b., Milltown, New Jersey, USA under the Code No. SK 650 WFX 577 and comprising a polyester-wood pulp mixture having a basis weight of 50 g/m and approximately 13 apertures per square cm.
Another preferred example of an apertured non-woven substrate, also available from Chicopee Manufacturing Co., under the Code No. AK 30 ML 1379 comprises a regenerated cellulose sheet of 3.0 denier fibres bonded with Rhoplex RA 8 binder (fibre:binder ratio 70:30) having a basis weight of 40 g/m² and ₁7 apertures/cm². A highly preferred square patterned apertured substrate of similar composition but fibre:binder ratio of 80:20 and basis weight 35 g/m² is also available from Chicopee BV Holland.
In general, apertured fabrics for the purposes of the invention have from 10 to 20 apertures/cm², preferably 12 to 18 apertures/cm².
The size and shape of the substrate sheet is a matter of choice and is determined principally by factors associated with the convenience of its use. Thus the sheet should not be so small as to become trapped in the crevices of the machine or the clothes being washed or so large as to be awkward to package and dispense from the container in which it is sold. For the purposes of the present invention sheets ranging in plan area from 130 cm 2 to 1300 cm² are acceptable, the preferred area lying in the range of from 520 _cm ² to 780 cm².
More usually, additive products in accordance with this aspect of the invention contain other detergent ingredients in addition to one or more of the essential components of the composition.
The type and level of such optional materials is constrained only by the requirements of mutual unreactivity, and, where a substrate is utilised as a carrier, by the loading limitations of the substrate. As described in more detail hereinafter, materials that are capable of reaction with any peroxy acid precursor present can be incorporated in additive products useful in the present invention but it is essential that the precursor is spatially separate therefrom, i.e. is disposed at a substrate location that is free or substantially free of the other reactant materials.
One factor determining the acceptable level of incorporation of an optional ingredient in an additive product is its physical characteristics i.e. whether it is liquid or solid, and if solid, whether it is crystalline or waxy and of high or low melting or softening point.
Highly desirable optional components for additive products in sheet substrate form are solid, water soluble or water dispersible organic processing aids of a waxy nature having a Mpt in the range 30-80°C. The most preferred processing aids have a softening point greater than 40°C and a melting point less than 80°C to permit their easy processing.
The preferred processing aids in such sheet substrate products serve as plasticisers or thickeners in the incorporation of compositions into or onto the substrate and ideally are non-hygroscopic solids that are melted to form molten fluids to which the compositions are added to provide mixtures having a viscosity of up to 30,000 centipoises at 50°C.
Typical solids are C₁₄-C₁₈ primary and secondary alcohols and C₁₂-C₂₀ fatty acids and ethoxylates thereof containing from 15 to 80 ethylene oxide groups per mole of alcohol, sorbitan esters of C₁₂-C₂₀ fatty acids and polyethylene glycols of Mwt 4000-10,000. Minor proportions of lower MWt glycols of MWt 1000-4000 can also be used to control mix fluidity but they should not form the major component of the processing aid. As stated hereinbefore, preferred materials are those of low hygroscopicity particularly the C₁₄-C₁₈ saturated fatty acids.
The C₁₆-C₁₈ fatty acids and polyethylene glycols of MWt 4,000-8,000, are particularly effective when used in amounts such that the weight ratio of compounds:processing aid lies in the range from 20:1 to 1:2 particularly from 4:1 to 1:1.
In addition to the foregoing optional components that are of primary value in incorporating the composition, onto, and releasing it from, the substrate, other optional conventional detergent ingredients as previously described can be incorporated into the composition provided that they are not reactive towards other composition components. Thus, surfactants, suds modifiers, chelating agents, anti-redeposition and soil suspending agents, optical brighteners, bactericides, anti-tarnish agents, enzymatic materials, fabric softeners, antistatic agents, perfumes and bleach catalysts can all be introduced into a wash liquor by means of the additive products of the present invention, subject to the contraints imposed by the loading limitations of the substrate.
In detergent additive products in which the compositions comprise a peroxy bleach precursor compound disposed on a substrate of either particulate or non particulate form, the substrate is preferably absorbent and the composition is impregnated therein.
Application of the precursor can be carried out in any convenient manner, and many methods are known in the art.
Where the substrate comprises a non-woven material or a foam article of sheet-like form, it is preferred to mix the composition with a compatible non-hygroscopic material of melting point ≤ 80°C, such as the processing aids hereinbefore described to provide a waxy solid in which the surfactant is present in the form of a solid solution and/or as a dispersed phase. The melting point range and waxy nature of polyethylene glycols of molecular weight ≤4000 make them useful for this purpose.
Where nonionic surfactants form components of the composition, their physical properties may permit their use as, or as part of, a liquid medium in which other solid components are incorporated.
As previously indicated, materials reactive towards any peroxy bleach precursor compounds present in the composition can be incorporated in detergent additive products containing them provided that the precursor and the reactive material are spatially separated from one another. Inorganic peroxygen bleaches such as sodium perborate monohydrate or tetrahydrate, sodium percarbonate, sodium persilicate or sodium perpyrophosphate, and also urea-hydrogen peroxide addition products, are materials which are sufficiently reactive to require this spatial segaration.
Where a precursor and an inorganic peroxygen bleach are incorporated in physically separate locations on the same non particulate sheet substrate, a convenient method of application is the deposition of the respective melts, suspensions or solutions as discrete bands of material on the substrate. This can be achieved using a divided extrusion head or by applying the melt or suspension to separate webs of substrate which are subsequently joined longitudinally. Preferably the bleach is applied as a dispersion of solid particles in a molten processing aid (as hereinbefore described) at a temperature in the range from 40° to 90°C. Using this technique, dispersion:substrate weight ratios of up to 15:1 can be obtained although for aesthetic reasons, dispersion loadings on substrates of fibrous character are limited in practice to weight ratios of 10:1. Furthermore, loading limitations imposed by the substrate surface area required for the incorporation of the precursor may limit the amount of bleach to less than 5:1. Provision must also be made for the separation of the bands or areas of bleach and the corresponding bands or areas of precursor during transport and/or storage. This is achieved by interposing layers of material between the layers of substrate or by producing patterns of deposited material that are not coincident on stacking of the substrate.
A preferred method of making the particulate substrate forms of detergent additive product is by applying a spray of the composition as a solution, dispersion or molten suspension on to a moving bed of particulate substrate in a rotating drum or pan fluidised bed, or a rotating blade mixer of the Schugi or Patterson-Kelly type.
In a preferred method of making sheet substrate additive products in accordance with the invention, the composition dissolved or dispersed in a molten processing aid is held in a trough formed by the nip of two horizontal rolls arranged side by side and rotating in opposite directions such that the nip is formed by surfaces having approximately the same velocity in a downward direction. Molten material is spread on one of the rolls and transferred to a continuous web of substrate whose speed is the same as that of the roll and which contacts the roll over a limited length of its periphery. The impregnated substrate is then contacted by a smoothing and spreading roll having a direction of rotation such that its contact surface is moving in the opposite direction to that of the substrate. The rolls employed in this technique are fabricated in metal and are heated to maintain the impregnating mixture in the liquid phase.
In sheet substrate additive products incorporating the non-linear acyl oxybenzene sulphonate and carboxylate bleach precursors of European Patent Application N3. 843010703, it has been found that the glyceryl monoester component of the present invention provides important processing advantages. The dispersion of such bleach precursors in a molten impregnating medium gives rise to very high viscosities at the conventional levels of incorporation of such materials and leads to problems in obtaining satifactory coating and impregnation of the sheet substrate. However, the use of the monoester as part of the molten medium in which the non meltable or high melting point components are dispersed maintains the viscosity of the mixture at a level which is satisfactory for the impregnation process and also facilitates the use of higher levels of precursor if required. Non-linear bleach precursor levels of from 2 to 10 g. per sheet of 1265 cm 2 area and 2.80 g. weight, can be achieved using glyceryl nonolaurate levels of from 2 to 4 g. in combination with a polyethylene glycol-ethoxylated nonionic mixture of from 8 to 10 g.
It has been found that non-linear acyl oxybenzene sulphonate bleach precursors, such as linear or branched C₇-C₁₀ acyl oxybenzene sulfonate, should preferably be present in an amount to provide a level of at least 2 ppm and preferably at least 5 ppm available oxygen in the wash liquor, in order that the benefit of the C₇-C₁₀ ^perox^y acid can be realised. Generally the weight ratio of the C₇-C₁₀ acyl oxybenzene sulfonate precursor to the other peroxy acid (e.g. peracetic acid) precursor should be such as to provide a C₇-C₁₀ alkyl peroxy acid:peracetic acid molar ratio in the range from 1:1 to 1:10. Under European washing conditions, blends in which the C₇-C₁₀ acyl oxybenzene sulfonate delivers from 5 to 50 ppm available oxygen in the wash liquor are preferred.
It is conventional with inorganic peroxy bleaches to provide a level of available oxygen in solution of from 50 ppm to 350 ppm by weight for heavy duty laundry purposes. However, when using organic peroxy bleaches a level of available oxygen provided by the organic peroxy compound may lie in the range from 2 ppm to 100 ppm, levels of from 3 ppm to 30 ppm being appropriate under conventional US washing conditions while levels of from 20 ppm to 50 ppm are more commonly used under European washing conditions. This level of available oxygen should be attained within the normal wash cycle time i.e. within 5-25 minutes depending on the particular wash cycle being employed.
For a machine having a liquid capacity in use of 20 to 30 litres, such a level of available oxygen requires the delivery of from 1 gr to 20 gr of organic peroxy compound percursor assuming quantitative conversion.
Various aspects of the invention are illustrated in the following Examples in which all parts and percentages are by weight unless otherwise specified.

EXAMPLES 1 - 6

The following compositions are prepared:
The compositions are prepared by spray drying the anionic and sequestering agent components together with the silicate, magnesium sulfate and brightener to form a base powder, onto which the ethoxylated nonionic components are sprayed as a liquid. To this base powder is added the perborate, suds suppressor and enzyme ingredients, the latter two in the form of prills in a carrier medium. Finally the perfume is sprayed onto the mixture to form the finished product. Where TAED or ISONOBS is a component of the product the precursor is formed into a prill using a carrier medium, by means of the technique disclosed in published European Application No. 0062523, and dry mixed with the base powder, prior to perfume addition.
TAE₈₀ forms a suitable prilling medium for TAED, the ratio of TAED:TAE₈₀ being 4:1 by weight. For ISONOBS the preferred prilling medium is the, or part of the, glycerol monoester component which can be used to form prills having satisfactory solution and physical stability characteristics at an _ISONOBS:glyceryl monoester ratio of 7:1 by weight.

EXAMPLES 8-13

Detergent additive products are prepared having the following composition in parts by weight (g).
The products were made in each case by forming a melt of the PEG GML and A 45E7 at approximately 80°C, dispersing the other components (except the perfume) therein and applying the resultant slurry to the substrate from an applicator roll with which the substrate was brought into contact.
Additional rolls were used to spread the slurry before it was cooled to ambient temperature to solidify the composition. Perfume was then sprayed on to the impregnated substrate to produce the final product.
Each of these additive products is added with a load of fabrics to an automatic washing machine to the product dispenser of which is added 135g of a detergent having the following formulation:
When the machine is filled (20 litres) so as to form a wash liquor, the dissolved compositions comprise

EXAMPLES 14-17

Laundry additive products having the following formulations are prepared in accordance with the method of Examples 7-9.
In the case of the formulation of Example 15, two separate impregnating mixes are prepared and are used to impregnate two substrate sheets, one mix comprising 6.3g of perborate, 2.Og of A45E7, 6.0g of PEG 6000 and 2.0g PEG 1500 and the other comprising the remaining ingredients. Each additive product is then added to a washing machine with 135g of the detergent formulation set out in Example 8 to form a laundry liquor in accordance with the invention.

Claims

1. A detergent composition adapted to provide greasy, oily stain removal from fabrics comprising

A) a surfactant system comprising from 5-40% by weight of the composition and composed of

1) an unethoxylated anionic surfactant;

2) an ethoxylated nonionic surfactant having an HLB in the range 9-15;

3) a glyceryl monoester of a C₈-C₁₄ aliphatic carboxylic acid, the glyceryl ester being present in an amount of at least 0.50% by weight of the composition;

B) a sequestering agent in an amount of from 1-60% by weight of the composition;

C) from 0% to 94% of other detergent ingredients.

2. A composition according to Claim 1 wherein the surfactant system (A) comprises:

(1) from 30% to 80% anionic surfactant

(2) from 12% to 60% ethoxylated nonionic surfactant

(3) from 2.5% to 30% glyceryl monoester

3. A composition according to either one of Claims 1 and 2 wherein the anionic surfactant is of the sulfate or sulfonate type.

4. A composition according to any one of Claims 1-3 wherein the ethoxylated nonionic surfactant is a C₉-C₁₅ primary alcohol ethoxylate or a C₆-C₁₂ alkyl phenol ethoxylate.

5. A composition according to any one of Claims 1-4 wherein the glyceryl monoester is present in an amount of at least 0.7% by weight of the composition.

6. A composition according to any one of Claims 1-5 wherein the C₈-C₁₄ aliphatic acyl moiety of the glyceryl monoester is a C₈-C₁₄ fatty acyl moiety.

7. A composition according to Claim 6 wherein the glyceryl ester is a mixture of glyceryl mono C₁₀-C₁₄ fatty esters.

8. A composition according to either one of Claims 6 and 7 wherein the glyceryl ester component comprises a mixture of mono-, di- and triesters in which the monoesters constitute at least 90% by weight of the mixture, there being not more than 1% of the mixture of triesters.

9. A composition according to any one of the preceding claims wherein the sequestering agent is present in an amount of from 5 to 50% by weight of the composition.

10. A composition according to any one of the preceding claims further including from 5-35% of an inorganic oxygen bleach of the perhydrate type.

11. A composition according to Claim 10 wherein the oxygen bleach is sodium perborate monohydrate or tetrahydrate.

12. A composition according to either one of Claims 10 and 11 further including an organic peroxyacid bleach precursor.

13. A composition according to Claim 12 wherein the bleach precursor is in the form of a dry mixed aggregate of fine particulate material bound together by means of the glyceryl monoester.

14. A composition according to Claim 13 wherein the aggregate comprises a prill formed by radial or axial extrusion.

15. An aqueous wash liquor comprising from 100 to 25,000 ppm of a composition in accordance with any one of Claims 1-14.

16. A method of forming a laundry liquor in accordance with claim 15 the step of adding an additive product containing the glyceryl ester component to a wash liquor incorporating at least the anionic surfactant.

17. A method of forming a laundry liquor in accordance with Claim 15 comprising dissolving a composition comprising the anionic surfactant and sequestering agent components and adding thereto an additive product comprising the ethoxylated nonionic and glyceryl ester components.

18. A method according to either one of claims 16 and 17 wherein the additive product is in the form of an impregnated flexible sheet.

19. A method according to either one of claims 17 and 18 wherein the dissolved composition also incorporates an inorganic oxygen bleach of the perhydrate type and the additive product incorporates a peroxyacid bleach precursor.