GB2203751A - Bleach substitute for detergent compositions - Google Patents

Abstract

A bleach-free detergent composition contains from 0.1 to 5% by weight of a water-soluble salt of a polymeric alpha -hydroxyacrylic acid as a bleach substitute. In particular, such a composition also contains an anionic optical brightener as well as a cationic softener. The composition can be liquid or in powder form.

Description

1505166 9 91 P1t BLEACH SUBSTITUTE FOR DETERGENT COMPOSITIONS The Present

invention relates-to detergent compositions, particu- larly in liquid form.

It is a weak point of all presently available liquid laundry detergents that they cannot incorporate peroxidic bleaching agents such as sodium perborate. Most liquid detergents give a neutral or alkaline wash liquor, and at those pH values peroxy compounds are ineffective as bleaching agents. There is therefore a need for a water-stable, pH-insensitive additive for liquid detergent compositions to enable removal of certain bleachable stains.

It has now been found that water-soluble salts of polymeric a-hydroxyacrylic acids are suitable for use as bleach substitutes in detergent compositions.

It has previously been proposed to incorporate polymeric a-hydroxyacrylic acids, their lactones or salts, as builders in detergent compositions. For this purpose quantities of at least 5 % by weight based on the total weight of dry ingredients were always used, and, at least in detergent powders, the conventional peroxy- or active chlorine-containing bleaching agents were always present.

Accordingly, the present invention provides a bleach-free detergent composition containing from 0.1 to 5 % by weight, based on the total dry weight of the composition, of a water-soluble salt of a polymeric a.-hydroxyacrylic acid. By "bleach-free" is meant that the 2 - 150-5166 composition contains neither peroxy compounds nor compounds containing active chlorine. Preferably the detergent compositions of the invention are also substantially phosphate-free. By "substantially phosphate-free" is meant that they contain less than 1 % of inorganic phosphates.

Preferred polymeric a-hydroxyacrylic acids are those containing repeating units of formula I - R, OH 1 1 -- C - G 1 1 R2 Uvull L_ 1 in which R, and R2 are independently hydrogen or Cl-3alkyl, unsubstituted or substituted by one hydroxy group or halogen atom and M is hydrogen, alkali metal or ammonium.

Preferably R, and R2 are independently hydrogen or methyl; more preferably both are hydrogen. Preferably M is Na, K or NH4.

The average molecular weight of the polymer is suitably above 300, preferably from 1,000 to 1,000,000, more preferably from 2,000 to 200,000, as measured by gel permeation chromatography (GPC). The polymers used according to the invention may be homopolymers or copolymers. Copolymers may contain only two or more different types of unit of formula I, or may contain one or more such units together with other polymerisable comonomers. Preferably however, the polymers contain only units of formula I.

The polymeric a-hydroxyacrylic acid may also be added in the form of the free acid, which may be at least partially in the form of an intramolecular or intermolecular lactone. In this case, however, it is essential to add a basic compound in sufficient quantity to convert the free acid or lactone into a water-soluble salt. Suitable basic compounds include ammonium or alkali metal hydroxides and carbonates.

3 - 150-5166 Prefered compositions contain:

a) 1-80 %, preferably 5-40 % of one or more anionic, non-ionic or zwitterionic surfactants b) 0-99 preferably 2-70 % of one or more builders C) 0-1-5 Xt preferably 0.1-2 % of a water-soluble salt of a polymeric ot-hydroxyacrylic acid containing repeating units of formula I, and d) 0.0-30 X, preferably 1-25 % of other conventional detergent components, for example hydrotropes, foam stabilizers, non-suifactant anti-foaming agents, carriers, softeners, brighteners, antimicrobial agents, enzymes, colouring and perfuming agents and basic compounds to adjust pH.

All percentages are by weight based on the total dry weight of the composition.

Detergent compositions in powder form preferably contain 10-20 % surfactants and 20-50 % builders.

Liquid detergent compositions, which are preferred, contain 3040% surfactants and 2-20 % builders dissolved in water. The solids content of the liquid formulation is preferably from 20 to 60 % by weight.

Surfactants suitable for use as component a) contain at least one hydrophobic group of 8-26, preferably 10-22, more preferably 12-18 carbon atoms, and at least one anionic, non-ionic or zwitterionic water-solubilizing group. Preferably at least 50 % wt. of component a) consists of one or more anionic surfactants, more preferably selected from sulphonate surfactants, sulphate surfactants and soaps.

4 - 150-5166 Examples of suitable sulphonates are the alkylbenzene sulphonates having preferably straight-chain C9_15 alkyl groups; alkane sulphonates obtainable from saturated C8_18 aliphatic hydrocarbons by sulphochlorination or sulphoxidation; and the so-called "olefin sulphonates" consisting of mixtures of alkene sulphonates, hydroxy alkane sulphonates and disulphonates which are produced by acid or alkaline hydrolysis of the sulphonation products of Ce-18 olefins with S03. Further suitable sulphonate surfactants are salts of CC-sulphonic acid derivatives of fatty acids and their alkyl esters.

Suitable sulphate-type surfactants include fatty alcohol sulphates, particularly those derived from coco and tallow fatty alcohols and oleyl alcohol; sulphated fatty acid alkylolamides or fatty acid monoglycerides; and the sulphated alkoxylation products of (C8_15 alkyl)phenols, fatty alcohols, fatty acid amides or fatty acid alkylolamides containing from 0.5-20, preferably 1-8 ethylene and/or propylene oxide units in the molecule.

The anionic surfactants are normally present in the form of their alkali metal (especially sodium) salts, or their salts with. ammonia, lower aliphatic amines or alkylolamines. Preferably mixtures of 2U sulphonates and soaps are used.

Suitable nonionic surfactants for component a) include the polyethyleneglycol ethers obtained by addition of from 4-100, preferably 6-40, more preferably 8-20 moles of ethylene oxide to one mole of a fatty alcohol, alkylphenol, fatty acid, fatty amine, fatty acid or sulphonic acid amide; together with the addition product of propylene or butylene oxide to these, so long as these addition products are still water-soluble. Further suitable nonionic surfactants include N-oxides of higher tertiary amines having one hydrophobic alkyl group and two shorter, e.g. C1-4 alkyl or alkylol groups.

Zwitterionic surfactants are those containing in the same molecule both acid groups e.g. carboxy-, sulphonic acid, sulphuric I 150-5166 acid half ester, phosphonic acid and phosphoric acid partial ester groups; and basic groups e.g. primary, secondary, tertiary and quaternary ammonium groups. Zwitterionic compounds containing quaternary ammonium groups include for example the betaines. Carboxy-, sulphate- and sulpho-betaines are of particular interest because of their high degree of compatibility with other surfactants.

Suitable builders as component b) are weakly acid, neutral and alkaline inorganic and organic salts, especially inorganic or organic complex formers. These include for example alkali metal bicarbonates, carbonates, citrates and tartrates. Phosphates, for example sodium tripolyphosphate, have been used as builders for many years, but their use is no longer desirable for environmental reasons, and hence those compositions which are substantially phosphate-free are preferred.

A further category of builders consist of water-soluble salts of high molecular weight polymers of unsaturated carboxylic acids selected from maleic, itaconic, mesaconic, fumaric, aconitic, acrylic, methylenemalonic and citraconic acids; and copolymers of these acids with each other or with other comonomers for example ethylene, propylene, methacrylic acid, crotonic acid, but-3-ene carboxylic acid, 3-methylbut-3-ene carboxlic acid, methyl vinyl ether, vinyl acetate, isobutylene, acrylamide and styrene. Preferred builders of this type are the salts of polyaerylic acid.

A yet further category of builders consists of phosporus- and/or nitrogen-containing organic complex formers. Examples of such compounds are alkali salts of amino- and polyamino-polycarboxylic acids, e.g. nitrilotriacetic acid and of di-, tri- and tetra phosphonic acids e.g. methylene diphosphonic acid, 1-hydroxy ethane-1,1-diphosphonic acid, methylamino or ethylamino-dimethylene phosphonic acid, ethylene diamine tetramethylenephosphonic acid and diethylene triamine pentamethylenephosphonic acid.

As hydrotropes in component d) may be employed for example salts of benzene, toluene, xylend or cumene sulphonic acids, or isopropanol.

Preferably the liquid composition contains at least one hydrotrope.

Conventional ingredients of many detergent formulations are optical brighteners and softening agents. However, because most optical brighteners are anionic in nature whereas most softening agents are cationic, it is found that interaction of the two types of additive leads to an undesirable quenching of the optical brightening effect. It has now been found that the presence of a polymeric a-hydroxyacrylic acid according to the present invention both increases the brightening efficiency of the optical brightener itself and also reduces the quenching effect of cationic softeners upon the brightener.

According to a preferred aspect of the invention, therefore, the detergent composition contains at least one optical brightener, preferably in an amount of 0.05 to 2 parts, more preferably 0.1 to 1 part, particularly 0.3 parts, to 1 part of the poly-a-hydroxyacrylic acid, all parts being by weight.

Preferably the optical brightener is anionic, and may be any anionic brightener conventionally used in detergent formulations for the brightening of cellulosic fabrics, and is preferably of the pyrazoline or stilbene type. Preferred optical brighteners are selected from the derivatives of bis(triazinylamino)stilbene disulphonic acid described e.g. in US Patents 3,018,287 and 3,970,647; and British Patents 1,243,276 and 1,313,469; of triazolyl stilbene sulphonic acid as described e.g. in German Patents 911,368; 942,395 and 1,008,248; and of bis(styryl)biphenyl sulphonic acid as described e.g. in French Patent 1,583,595.

Further preferred optical brighteners for use in the composition of the invention are the compounds of the following formulae II to V M10 5 R 3 H.3 H -/ \. R 5 -- YN" H NR SO m$ 4 3 6 7 150-5166 in which R3 to R6 are independently selected from M90 H H MS -N /--\ 1 0 3 \. 9 - N-QO 3 me CH 1 3 -NH(CH2)2-30CH3Y -N(CH2CH2OH)2t -NCH2CH2OHY -NH2, NHR, N(R)2, -OCH3P -C19 -NH-CH2CH2SO3M1 and -NHCH2CH2OH; 0 R MI; '3 R N 9 CN N - =C_ NI" 1 " N R R 8 so 3 m 10 in which R7 to R10 are independently selected from hydrogen, alkyl, -0 and SO 3 m 1 -CY R 12 IN xC-P-N I v R'HI -'N:& :W, A0 11 Mao.

3 S' 1 in which R,, is selected from hydrogen, S03M1 and -N(CH3)2 and R12 is selected from hydrogen, S03M1 and -OCH3; 8 150-5166 R H H R C 15 H -c v R 14 H R16 in which R13 to R16 are independently selected from -S03W, -S02N(R)2t -OCH39 -CN, -Cl, -COOCH3; and -CON(R)2.

R in the above formulae is C1-4 alkyl.

M, in the above formulae is hydrogen or a non-chromophoric cation, the preferred non-chromophoric cations being alkali metal cations and optionally substituted ammonium cations, e.g. mono-, di or tri-(Cl-Jalkyl ammonium and mono-, di- and tri-(C2-Jalkanol ammonium cations, as well as the ammonium cation itself; the most preferred cation being the sodium cation.

Most preferred optical brighteners are those of the bis(triazinylamino)stilbene disulphonic acid series.

Cationic softeners are known products and are in commercial use.

They include both non-quaternized and quaternized compounds.

Non-quaternized cationic softeners are, for example, the reaction products of fatty acids or fatty acid chlorides with amino alcohols or the reaction products of fatty acids with short-chain polyamines.

Quaternized cationic softeners include tetra- or tri-alkyl ammonium halides, sulphates, formates, lactates or alkylpyridinum halides or derivatives thereof, containing at least one fatty alkyl group; e.g. trimethylalkyl ammonium chlorides, dialkyl dimethyl ammonium chlorides, hydroxyalkyl bis-acylamino alkyl ammonium sulphates, dimethyl alkoxymethyl ammonium chlorides, N-alkylpyridinium chlorides or tris(hydroxyalkyl) ammonium formates esterified with a fatty acid. Particularly preferred is distearyl dimethyl ammonium chloride.

The preparation of the detergent compositions according to the 9 150-5166 invention may be carried out by conventional mixing processes.

The components are preferably chosen so that the composition has' a pH in the neutral to strongly alkaline range. Thus laundry detergents for household use may have a pH from 7.5 to 10, and those for industrial use from pH 7.5 to 14. The pH may be adjusted by addition of a suitable basic compound.

Detergent compositions according to the invention are used in conventional ways for washing textile materials, in particular textiles consisting wholly or in part of cotton. The amounts used are in the range of 5-10 g1I.

The following Examples, in which all parts and percentages are by weight, illustrate the invention.

150-5166 Example 1

A liquid detergent of the following composition is prepared by mixing the individual components:

sodium xylene sulphonate 8.0 % (20 % of 40 % aqueous sol.) sodium polyacrylate (MY 100,000) 8.0 % (20 % of 40 % aqueous sol.) dodecylbenzenesulphonic acid 8.0 % coco fatty acid 8.0 % potassium hydroxide 7.25% (14.5% of 50% aqueous sol.) sodium bicarbonate 2.5 sodium salt of poly cc-hydroxy- acrylic acid (MW 5,000) 0.8 demineralized water to 100 The resulting detergent has a pH value of 9.6.

Washing tests are carried out on various soiled cotton test fabrics, using 8 g/1 of the composition of Example 1 in water of 181 dH hardness to give a wash liquor of pH 9.4. Washing is carried out at 601C for 23 minutes at a liquor to goods ratio of 5:1 in a.Schultless domestic washing machine. The whiteness of the test samples is evaluated before and after washing. The detergent of Example 1 gives 2U superior whiteness compared with an identical detergent formulation in which the poly cc-hydroxyacrylic acid is omitted.

Example 2

A liquid detergent of the following composition is prepared by mixing the ingredients:

coco fatty acid 15.0 % oleic acid 5.0 % lauryl poly(7)glycol ether 12.0 % triethanolamine 5.0 sodium hydroxide 3.45% (11.5% of 30% aqueous sol.) isopropanol 2.0 150-5166 optical brightener (Leucophor BSB liquid, Sandoz Ltd.) 0.5 % sodium poly &-hydroxyacrylate 0.8 % (MW 65,000) ethylene glycol 15.0 % sodium cumene sulphonate 2.0 % water to 100 % and has a pH value of 7.5. When wash tested as described in Example 1 the wash liquor has a pH value of 7.3. A good bleaching effect is obtained.

Examples 3 and 4 Aqueous detergent slurries are prepared according to the following formulation:

sodium dodecyl benzene sulphonate 8.0 % ethoxylated tallow alcohol (14 EO) 2.9 % sodium soap chain length mixtures: C12-16: 13-26 % C18-22: 74-87 % 3.5 % nitrilo triacetic acid sodium salt 5.0 % 2U zeolite 20.0 % sodium silicate Si02/Na20: 3/1 7.5 % magnesium silicate 1.9 % carboxy methyl cellulose 1.2 % sodium sulphate 21.0 % polylactone of poly-a-hydroxyacrylic acid 0.5 % (MW 5, 000) 4,41-bis(4-anilino, 6-morpholino triazinyl-2-amino)-stilbene-2,21- disulphonic acid sodium salt 0.15% 12 - 150-5166 Softener:

Ex. 3: disteary1dimethylammonium chloride 6.0 % Ex. 4: alkyl hydroxyalkyl bis(P-C16-20 acylamino- ethyl) ammonium methanesulphonate 6.3 % water to 100 %.

The-compositions of Examples 3 and 4 are tested on cotton samples bleached without optical brightener. The washing tests are carried out with 2 kg polyester as ballast in a Schulthess Super 45 (Trade Mark) washing machine on programme 4. Comparative tests are also carried out using identical compositions in which the lactone of poly (x-hydroxyacrylic acid is omitted.

The washing conditions are as follows:

cylinder volume 43 1 amount of water 17 1 amount of detergent 8 g1l temperature 6011C heating time about 11 min washing time about 15 min water hardness 18"dH pH of the wash liquor 9.7 After washing the whitening effect of the detergent composition on the cotton samples is measured by means of a spectrophotometer (Datacolor Type 70-80) and expressed as the CIE whiteness degree (CIE publication No. 15.2).

Better results in the whitening effect are obtained in the presence of polylactone derived from poly-a-hydroxyacrylic acid than with compositions free of polylactone.

13 - 150-5166

Claims (14)

CLAIMS:

1. A bleach-free detergent composition containing from 0.1 to 5% by weight, based on the total dry weight of the composition, of a water-soluble salt of a polymer (x-hydroxyacrylic acid.

2. A composition according to Claim 1 which is substantially phosphate-free.

3. A composition according to Claims 1 or 2 in which the polymeric a-hydroxyacrylic acid contains repeating units of formula I R, OH 1 1 c c R2 &OM L_ ___j in which R, and R2 are independently hydrogen or C1-3 alkyl, unsubstituted or substituted by one hydroxy group or halogen atom and M is hydrogen, alkali metal or ammonium.

4. A composition according to Claim 3 in which the polymeric (x-hydroxyacrylic acid has an average molecular weight from 2,000 to 200,000.

5. A detergent composition according to anyone of the preceding claims containing a) 1-80% of one or more anionic, non-ionic or zwitterionic surfactants, b) 0-99 %, of one or more builders, c) 0.1-5 %, a water-soluble salt of a polymeric a-hydroxyacrylic acid containing repeating units of formula I, as defined in Claim 3, and 14 150-5166 d) 0.0-30 %, of other conventional components of detergent compositions, all percentages being by weight based on the total dry weight of the composition.

6. A detergent composition according to Claim 5 containing 5-40 % of component a) 2-70 % of component b) 0.1-2% of component c) 1-25 % of component d) and the balance being made up with water.

7. A detergent composition according to Claim 6 in powder form containing 10-20 % of component a) 20-50 % of component h).

8. A liquid composition according to Claim 6 containing 30-40 % of component a) 2-20 % of component b) and a solids content of 20 to 60 % by weight.

9. A detergent composition according to any one of the preceding claims containing at least one optical brightener in an amount of 0.05 to 2 parts to 1 part of the polymeric a-hydrocyacrylic acid, all parts being by weight.

10. A composition according to Claim 9 containing at least one anionic brightener.

11. A composition according to Claims 9 and 10 containing also a cationic softener.

12. A composition according to Claim 11 in which the cationic softener is distearyldimethylammonium chloride.

- 150-5166

13. A bleach-free detergent composition as described in any one of Examples 1-4.

14. A process for washing of textile materials comprising the addition of 5-10 g/1 of a composition according to any one of the preceding claims.

3700/PG/DH/FZ Publiblied 1988 at The Patent Office, State House, 68171 High Holborn, London WC1R 4TP. Firther copies may be obtained from The Patent Office.

Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray, Kent. Con. 1187.