GB2151252A

GB2151252A - Detergent composition

Info

Publication number: GB2151252A
Application number: GB08430988A
Authority: GB
Inventors: Jean-Pierre Chavannes
Original assignee: Sandoz AG
Current assignee: Sandoz AG
Priority date: 1983-12-10
Filing date: 1984-12-07
Publication date: 1985-07-17
Also published as: IT8449249A1; JPS60141798A; FR2556364A1; CH661743A5; GB8430988D0; IT1199232B; IT8449249A0; GB2151252B; FR2556364B1; BE901196A

Abstract

An aqueous liquid detergent composition comprises (a) a salt of a polycarboxylic acid (b) an anionic surfactant and (c) a hydrotropic agent the weight ratio of (a) : (b): (c) being 10:2-40:5-20, the concentration of (a) + (b) + (c) being 10-50% by weight of the total weight of the composition, and the pH of the composition being adjusted to 7-14, has stability at temperatures up to 50 DEG C and is suitable for domestic and industrial laundering.

Description

SPECIFICATION Improvements in or relating to organic compounds This invention relates to stable liquid detergents, which are phosphate- free and which are complete and ready for use.

It is known that the use of phosphates in detergents adversely affects the oxygen balance of rivers into which waste water is discharged. However, phosphate-free detergents generally have lower cleaning power than those containing phosphates, and may often lead to damage to washing machines and to the washed textiles having an undesirably harsh handle. It has now been found that detergent compositions according to the present invention have excellent cleaning properties and are complete and ready for use in industrial and hospital laundry as well as for domestic laundry, at temperatures from room temperature to boiling point.

It is known from USP 4388205 to use a composition containing a polycarboxylic acid together with an alkylbenzenesulphonate detergent. However, if such a composition is added directly to the detergent the system is unstable and within a few minutes becomes cloudy and eventually separates into two phases. By contrast, the liquid compositions of the present invention remain stable for long periods of time at temperatures up to 500C.

Accordingly, the present invention provides an aqueous liquid detergent composition comprising (a) one or more polycarboxylic acids in salt form (b) one or more anionic surfactants and (c) one or more hydrotropic agents, the weight ratio of (a) (b): (c) being in the range 10:2-40:5-20, the weight of (a) being calculated as free acid, the concentration of (a) (as salt form) + (b) + (c) being 10-50% by weight of the total weight of the composition, and the pH of the composition being adjusted to 7-14.The detergent composition may contain as further optional components (d) one or more non-ionic surfactants (0-5 parts by weight based on 10 parts by weight of (a) (e) one or more optical brighteners (0-0.5 parts) (f) sodium or potassium metasilicate (0-15 parts) (g) one or more softening agents (0-5 parts) (h) one or more enzymes (0-2 parts) (i) one or more perfumes (up to 1 part) (j) one or more anionic dyes (up to 0.05 parts) and (k) one or more opalescent agents (up to 5 parts).

If sodium or potassium metasilicate (f) is present, the pH must be adjusted to > 10.5 to prevent precipitation of silicic acid. The total concentration of components (a) - (k) together with any alkali used to adjust the pH is preferably from 10-50% by weight of the total composition, the balance being made up by water.

Preferred quantities of components (b), (c) and (when present) (d) - (i), based always on 10 parts by weight of component (a), are: (b): 4-20 parts by weight (f): 6-12 parts by weight (c): 8-20 parts by weight (g): 0.5-3 parts by weight (d): 0.5-2 parts byweight (h): 0.5-1 partbyweight (e): 0.2-0.4 parts by weight (i): 0.2-0.5 part byweight.

The polycarboxylic acids of component (a) are preferably polymeric carboxylic acids, for example homopolymers of acrylic acid, methacrylic acid, crotonic acid, hydroxyacrylic acid, maleic acid, itaconic acid, mesaconic acid, aconitic acid, methylene-malonic acid and citraconic acid. Copolymers of the above acids with each other or with ethylenically unsaturated compounds for example ethylene, propylene, vinyl alcohol, vinyl ether, vinyl acetate, furan, acrolein, acrylamide and acrylonitrile are also suitable polycarboxylic acids. More preferred acids are the commercially available polyacrylic and polyhydroxyacrylic acids, having average molecular weights from 500-1,000,000, more preferably 1000-500,000 particularly 10,00080,000.

The nature of the salt form of the acid will depend upon the alkali used to adjust the pH to the required alkaline range, and will usually be the sodium or potassium salt form.

Suitable anionic surfactants as component (b) include - fatty acids and their alkali metal, ammonium and organic base salts, - carboxylated products, particularly carboxymethylated products of ethoxylated fatty alcohols, preferably C5-18 fatty alcohols, - sulphates and sulphonates of fatty acids, fatty acid esters and fatty acid amides, - linear or branched C5,8 alkyl sulphates and sulphonates - sulphates of ethoxylated products, particularly sulphates of compounds listed under (d) below - sulphonates of polycarboxylic acid esters - (C5.18alkyl)benzenesulphonates and (C1.4alkyl)- or di(C1.4alkyl)naphthalene sulphonates.

The term "fatty acids" includes saturated and unsaturated C5.22carboxylic acids, preferably C12 18 carboxylic acids.

Preferred anionic surfactants are those having an HLB-value from 9-14, and particularly mixtures of such anionic surfactants. Preferred mixtures are those of alkylbenzenesulphonates with fatty acids, e.g. a mixture of dodecylbenzene-sulphonic acids with soya fatty acids, in the weight ratio of from 20:1 to 1 :5, preferably approximately 2:1.

Compounds listed above as anionic surfactants which are described as acids, or which contain sulphonic acid groups, will of course be converted to their salt forms by the alkali used to adjust the pH to alkaline values.

The hydrotropic compound of component (c) may be for example urea, dicyandiamide and its derivatives, alcohols, glycols, glycol ethers, glycol esters and (C1.4alkyl)-substituted benzenesulphonates provided that these compounds show no cloud point in distilled water at temperatures up to the boiling point, that is, remain water-miscible. Preferred compounds are (C1.4)alkyl-substituted benzene sulphonates and their salts, e.g. cumene sulphonate and xylene sulphonate; urea and hexylene glycol.

The non-ionic surfactants of component (d) are suitably selected from: - propylene oxide/ethylene oxide (PO/EO) block co-polymers commercially available under the trademark Pluronic; - addition products of 1-100 moles of EO and/or PO, preferably EO, to fatty alcohols, preferably C52 aliphatic alcohols, more preferably C12-18 alcohols e.g. lauryl alcohol and oleyl alcohol; - addition products of EO and/or PO (preferably 5-200 mols) to fatty amines. Preferred products are the addition products of EO to aliphatic amines or polyamines containing a C,2,8alkyl or alkenyl group, e.g.

dodecylamine, stearylamine or tallow fatty amine; - polyglycol esters of fatty acids, preferably of saturated or unsaturated C5 carboxylic acids, more preferably Cl2.18 carboxylic acids, e.g. oleic, stearic, palmitic and myristic acids and their mixtures; - ethoxylated fatty acid alkanolamides, particularly of the above-named fatty acids; and - addition products of EO and/or PO (preferably 1-30 moles) to alkylphenols. Preferred products are addition products of EO to linear or branched mono- or di- (C518alkyl)phenols e.g. isooctyl phenol, di-t-butylphenol, nonylphenol or dodecylphenol.

Components (e) to (k) are known additives, and are used in known manner. The detergent composition may optionally also contain small amounts (e.g. 1-2% of the dry weight of active substance) of a cationic surfactant.

If the detergent contains an alkali metal metasilicate, then the pH must be > 10.5. Such detergents are primarily suitable for industrial laundries.

The pH of the detergent according to the invention is preferably 7.0-10.5, more preferably 7.5-9, for household laundering: for industrial laundering it is preferably 10.5-14. The pH can be controlled in these alkaline ranges by addition of alkali metal hydroxides, akali metal carbonates, alkylamines or hydroxyalkylamines, e.g. triethanolamine.

The detergent according to the invention is complete and ready for use, and can be used for all wash temperatures from 20-100"C. It is preferably added to the wash water in the form of a liquid having a concentation of 15-40% by weight, based on dry weight of active substances in the entire solution, which has unexpectedly good storage stability and ease of dilution due to the selected proportions of components a), b) and c).

The amount of detergent used will depend upon the degree of soiling, but normally 0.1-60 glkg, preferably 1-40 g/kg (active substance/dry weight of substrate) will be sufficient.

The detergent according to the invention has an exceptionally good cleaning effect against stubborn stains, e.g. blood, albumin, soot, graphite, grease, oils and fats, particularly on dyed or undyedfabrics of cellulose, polyamide, polyester or mixtures of these. They are suitable both for industrial and domestic use and can be used in continuous or batch processes. They are biodegradable, low-foaming and unaffected by hard water.

The preparation of the detergent composition may be carried out by taking a aqueous solution of the polycarboxylic acid, preferably in salt form, stirring the remaining components into this, in the order given in the Examples, then finally adding demineralised water until the desired concentration is reached, and continuing to stir until a homogeneous solution results.

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

Examples The compositions of Examples 1-14 as shown in the Table may be prepared by adding the components in the stated order and stirring at room temperature until a homogeneous solution is obtained.

The components are identified as follows: la potassium polyacrylate (MW 120,000) as 26% aqueous solution 1 b sodium polyacrylate (MW 53,000) as 40% aqueous solution 1 c polyacrylic acid (MW 5000) as 50% aqueous solution 2a sodium xylene sulphonate (40% aqueous solution) 2b sodium cumene sulphonate (40% aqueous solution) 3a dodecylbenzene sulphonic acid 3b lauryl ether sulphate (66% paste) 4a soya fatty acid 4b oleic acid 4c lauric acid 5a potassium hydroxide (50% aqueous solution) 5b sodium hydroxide (30% aqueous solution) 6 optical brightener (30% aqueous solution) 7 softener (25% aqueous solution) 8 tetramethylnonanol + 6.5 moles ethylene oxide, 50% carboxymethylated (67% aqueous solution) 9 potassium metasilicate (40% aqueous solution) 10 demineralised water.

For each Example, the first column gives the number of parts by weight of each component added as solution or as pure substance as indicated above, and the second column gives the percent by weight of each active component expressed as dry weight, together with the total percentage by weight of water, including that added in the form of solutions.

The products are all mobile light yellow liquids, stable from 0 -50 and have good washing efficacy from 20" to the boil.

The composition of Example 2 is suitable for use in industrial laundries, those of the other Examples for domestic use.

For components la and 1 b, the dry weight given in the second column of the examples is the dry weight of the salt form. In order to convert this to dry weight of free acid for comparison with the stated weight ratios of (a):(b):(c) it is necessary to multiply by a factor of 0.65 for the potassium salt 1 a and by a factor of 0.77 for the solium salt ib.

TABLE Example 1 2 3 4 5 6 7 8 Component 1a 40 10,4 40 10,4 40 10,4 - - - - 40 10,4 40 10,4 40 10,4 1b - - - - - - - - 22 8,8 - - - - - 1c - - - - - - 14,7 7,35 - - - - - - - 2a 35 14 21,6 8,6 35 14 - - 35 14 30 12 35 14 35 14 2b - - - - - - 35 14 - - - - - - - 3b 7 7 3,6 3,6 7 7 7 7 7 7 5,6 5,6 7 7 7 7 3b - - - - - - - - - - 1,4 0.9 - - - 4a 3,5 3,5 1,8 1,8 3,5 3,5 3,5 3,5 3,5 3,5 3,5 3,5 - - - 4b - - - - - - - - - - - - 3,5 3,5 - 4c - - - - - - - - - - - - - - 3,5 3,5 5a 5 2,5 - - 5 2,5 28 14 - - 4,3 2,15 5 2,5 5 2,5 5b - - - - - - - - 6 1,8 - - - - - 6 1 0,3 1 0,3 1 0,3 1 0,3 1 0,3 1 0,3 1 0,3 1 0,3 7 - - - - - - - - - - - - - - - 8 - - - - 0,2 0.13 - - - - - - - - - 9 - - 32 12,8 - - - - - - - - - - - 10 8,5 62,3 - 62,5 9,3 62.17 10,8 53,85 25,5 64,6 14,2 65,15 8,5 62,3 8,5 62,3 Total 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 TABLE (continued) Example No. 9 10 11 12 13 14 Component 1a 40 10,4 30 7,8 54,5 14.2 27,3 7,1 11.4 3 21,8 5,7 ib - - - - - - - - - - - - 1c -- -- -- -- -- - 2a 35 14 35 14 12,5 5 25 10 2.6 1 20 8 2b - - - - - - - - - - - - 3a 7 7 6,3 6,3 1,3 1,3 0,7 0,7 5.6 5.6 10,7 10,7 3b - - - - - - - - - - - - 4a 3,5 3,5 - - 0,7 0,7 0,3 0,3 2.8 2.8 5,3 5,3 4b - - 7 7 - - - - - - - - 4c - - - - - - - - - - - 5a 5 2,5 6,3 3,15 2 1 1 0,5 4 2 10 5 5b - - - - - - - - - - - - 6 1 0,3 1 0,3 1 0,3 1 0,3 1 0,3 1 0,3 7 5 1,25 - - - - - - - - - - 8 - - - - - - - - - - - 9 - - - - - - - - - - - - 10 3,5 61,05 20,7 61,45 28 77,5 44,7 81,1 72.6 85.3 31.2 65 Total 100 100 100 100 100 100 100 100 100 100 100 100

Claims

1. An aqueous liquid detergent composition comprising (a) one or more polycarboxylic acids in salt form (b) one or more anionic surfactants and (c) one or more hydrotropic agents, the weight ratio of (a):(b):(c) being in the range 10:2-40:5-20, the weight of (a) being calculated as free acid, the concentration of (a) (as salt form) + (b) + (c) being 10-50% by weight of the total weight of the composition, and the pH of the composition being adjusted to 7-14.

2. A composition as claimed in Claim 1 in which the weight ratio of (a):(b):(c) is in the range 10:4-20:8-20.

3. A composition as claimed in Claim 1 or Claim 2 containing one or more of the following further components (d) one or more non-ionic surfactants (0-5 parts by weight based on 10 parts by weight of (a) (e) one or more optical brighteners (0-0.5 parts) (f) sodium or potassium metasilicate (0-15 parts) (g) one or more softening agents (0-5 parts) (h) one or more enzymes (0-2 parts) (i) one or more perfumes (up to 1 part) (j) one or more anionic dyes (up to 0.05 parts) and (k) one or more opalescent agents (up to 5 parts), provided that if sodium or potassium metasilicate is present, the pH of the composition is adjusted to # 10.5.

4. A composition as claimed in any one of the preceding claims in which component (a) is a polyacrylic or polyhydroxyacrylic acid of average molecular weight from 500-1,000,000.

5. A composition as claimed in any one of the preceding claims in which component (b) is a mixture of a (C518alkyl)-benzenesulphonate with a fatty acid.

6. A composition as claimed in any one of the preceding claims in which component (c) is selected from (C14alkyl)-benzenesulphonates, urea and hexylene glycol.

7. A composition as claimed in Claim 6 containing (a) 10 parts by weight of polyacrylic acid of average M.W. 1000-500,000 in the form of its sodium or potassium salt (b) 4-20 parts by weight of a mixture of dodecylbenzene sulphonic acid with soya fatty acids in the weight ratio offrom 20:1 to 1:5 (c) 8-20 parts by weight of cumene sulphonate or xylene sulphonate.

8. A composition as claimed in Claim 7 containing in addition (d) 0.5-2 parts by weight of a non-ionic surfactant.

9. A composition as claimed in Claim 7 or Claim 8 containing in addition (f) 6-12 parts by weight of sodium or potassium metasilicate, and having a pH > 10.5.

10. An aqueous liquid detergent composition as described in any one of the Examples.

11. A method of washing dyed or undyed fabrics of cellulose, polyamide, polyester or mixtures of these comprising the step of treating the substrate with from 0.1-60 g of a composition as claimed in any one of the preceding claims per Kg dry weight of substrate in an aqueous bath at from 20-100"C.