GB1572606A

GB1572606A - Liquid detergent composition

Info

Publication number: GB1572606A
Application number: GB1333476A
Authority: GB
Original assignee: Unilever PLC
Current assignee: Unilever PLC
Priority date: 1976-04-01
Filing date: 1976-04-01
Publication date: 1980-07-30
Also published as: DE2713704A1; CA1098409A; DE2713704B2; NL7703179A; DE2713704C3; JPS5366909A

Description

(54) LIQUID DETERGENT COMPOSITION (71) We, UNILEVER LIMITED, a company organised under the laws of Great Britain, of Unilever House, Blackfriars, London EC4, England, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to an aqueous built liquid detergent composition and more particularly to an aqueous built, highly alkaline liquid detergent composition with an increased solids content.

Aqueous built liquid detergent compositions are well-known in the art, and many types and formulations have already been described in the prior art. Such formulations are generally of the type containing one or more synthetic surface-active agents, one or more water-soluble builder salts, and water-soluble detergent adjuvants. A governing factor in formulating such liquids is the solubility of the various ingredients, to arrive at a homogeneous, stable, clear liquid. This often sets limits to the amounts of the ingredients that can be incorporated, so that it is not always possible to prepare more concentrated liquids without taking special steps and/or using special ingredients.

This is particularly true for liquid detergent compositions with a relatively high pH, normally used in e.g. industrial laundering.

It has now been found that an aqueous built liquid detergent composition with a high pH and an increased solids content can be prepared, using a fatty acid soap as the main detergent-active compound, as well as a certain amount of free potassium hydroxide, in formulations containing alkaline builder salts, as well as sodium carboxymethylcellulose.

The present invention therefore relates to an aqueous built liquid detergent composition comprising, as essential ingredients, a potassium fatty acid soap, a potassium builder salt, sodium carboxymethylcellulose and free potassium hydroxide, said composition having a solids content of 32-40% by weight and a pH of > 11 ( 1% aqueous solution). Further details of the invention, as well as particular features thereof, will now be discussed below.

The fatty acid soap is a potassium salt of fatty acids having from 10-18 carbon atoms in the fatty acid radical. Typical examples thereof are lauric, myristic, oleic, stearic and palmitic acid, as well as mixtures thereof, and mixtures of fatty acids derived from natural sources such as coconut- and palmkernel oil.

Fatty acids obtained from coconut oil are especially preferred. Depending upon the KOH-content, the amount of the soap component used in the composition of the invention varies from 1-15%, and preferably from 2-8% by weight, based on the free fatty acids incorporated in the composition. Other detergent-active materials may also be present, such as nonionics, carboxylated nonionics, and anionics.Examples of the former are ethylene oxide condensation products of primary C8 - C18 alcohols, such as C9-Cll alcohol condensed with 6 moles of ethylene oxide; examples of the second are alkyl(poly- 1 - oxapropene)oxaethane carboxylic acids such as lauryl(poly-1-oxapropene)oxaethane carboxylic acid. Examples of the latter are: alkylaryl sulphonates, alkane sulphonates, alkyl sulphates, alkylether sulphates and olefin sulphonates. These additional detergent-active materials are used in amounts less than half the amount of soap, preferably less than one third of the amount of soap.

The potassium builder salts used according to the present invention are potassium salts, such as potassium ortho-, pyro- and polyphosphates, eg. pentapotassium tripolyphosphate, tetrapotassium pyrophosphate and tripotassium orthophosphate. Other potassium salts may also be used, such as potassium carbonate and borate, but these are less preferred. Of the above builder salts, pentopotassium tripolyphosphate is the preferred one. This can be incorporated in the composition of the invention either as such, e.g. in powdered form, or in pre-dissolved form. The amount of potassium builder salt incorporated in the composition varies from 5-25% by weight, preferably from 10-20% by weight of the composition. Alkali metal silicates may also be present in the composition of the invention, e.g.

sodium or potassium silicate, in an amount of 1-15ro, but preferably 1-5% by weight.

This compound functions as a builder, as well as alkaline material to aid in obtaining and maintaining the desired pH of the composition.

The composition further contains sodium carboxymethyl cellulose. It has been found that not every type of carboxy methylcellulose (CMC) is suitable in the present invention.

The CMC to be incorporated according to the present invention should have a degree of substitution of at least 0.7, and should have a viscosity (Höppler at 20 OC in cP) of between 20 and 100. A typical example of such a CMC has a DS of 0.7, a DP of 150 and a viscosity of 25-32 cP for a 2% aqueous solution. The amount of CMC that is incorporated varies from 0.2-1.5, preferably 0.5-1% by weight.

The alkalinity of the compositions of the invention is obtained by the addition of potassium hydroxide. Sufficient potassium hydroxide should be added to neutralize acid components if present in the composition, and to provide for free potassium hydroxide, necessary to adjust the pH of the composition to a value of > 11. The amount of free KOH present in the composition varies from 2 to 10%, preferably from 4 to 8% by weight.

The composition of the invention may furthermore advantageously contain a hydrotrope, such as sodium xylene sulphonate, sodium toluene sulphonate, sodium toluene sulphonate, phosphate esters, a solvent such as hexylene glycol, and fluorescers. As to the latter, it has been found that fluorescers that do not readily dissolve in the system as such, e.g. fluorescers in acid form, are preferably used together with a small amount of a carboxylated nonionic as herebefore described and hexylene glycol, whereby they are completely dissolved. The hexylene glycol can be replaced by triethanol amine, resulting in an end product with a better stability.

The compositions of the invention may furthermore comprise other ingredients in minor amounts, such as perfumes, various anti-redeposition agents, opacifiers, thinning agents and co-solvents.

The compositions of the invention have a total solids content of 3240% by weight, are stable liquid laundry products, and are suitable e.g. for laundering cotton. They work both in soft arid in hard water.

It has furthermore been found that the compositions of the invention should be prepared by a particular process. This process comprises the essential step that the soap and the builder, and as the case may be part or all of the KOH, should be added to an aqueous medium that contains the CMC and as the case may be, the fluorescer and the carboxylated nonionic and hexylene glycol or triethanol amine.A preferred process comprises the following steps: 1) prepare an aqueous solution of triethanol amine or hexylene glycol and the carboxylated nonionic; 2) add the fluorescer under agitation to obtain a clear solution; 3) add balance of water; 4) add CMC under agitation until no lumps remain; 5) add hydrotrope; 6) add the fatty acids under agitation to obtain a homogeneous dispersion; 7) add potassium hydroxide under agitation to completely neutralize the fatty acids; 8) add predissolved pentapotassium tripolyphosphate and the alkaline silicate.

Naturally, variations are possible, as long as the addition of the soap, the builder and KOH takes place after the CMC and fluorescer have been dissolved first.

The invention will now be further illustrated by way of example.

EXAMPLE The following formulations were prepared: % by weight distilled coconut fatty acids 4 4 lauryl(poly-l -oxapropene)oxae thane carboxylic acid 0.5 0.5 sodium xylene sulphonate (90So) 5.0 5.0 alkaline sodium silicate (40it) 5.0 5.0 Ooh(50%) 20.5 16.9 pentapotassium tripoly phosphate (507O) 28.0 28.0 NaCMC(DS0.7DPl50 visc. 25-32 cP) 0.7 0.7 hexylene glycol 1.5 triethanol amine - 2.5 fluorescer (Blankophor() BBH 766, a diethanol- amine- and anilyl-substituted N, N'-bis-l, 3, 5 triazinyl-4,4'- diaminostilbene-2 ,2'-disulphonic acid type fluorescer) 0.15 0.15 water to 100 to 100 the pH of these compositions (1% aqueous solution) was: 12.1 12.1 % by weight and the solids content (in 1% by weight) 37.5 36.7 These products were prepared as follows: The hexylene glycol or triethanol amine and the lauryl (poly-l-oxapropene)oxaethane carboxylic acid were added to 18% by weight of softened water. Subsequently the fluorescer was added, and the mixture stirred until the fluorescer was completely dissolved. Then the balance of the water was added, and subsequently the CMC was stirred in until all lumps had disappeared. Thereafter the sodium xylene sulphonate and the coconut fatty acids were added, and the mixture stirred until it was homogeneous. Then the KOH was stirred in until the neutralization was complete, and finally the pre-dissolved potassium tripolyphosphate, and the alkaline sodium silicate were added.

The products were clear, stable liquids.

WHAT WE CLAIM IS: 1. An aqueous built liquid detergent composition, comprising 1-15% by weight of a potassium soap of a fatty acid having from 10-18 carbon atoms in the fatty acid radical, the weight percentage being based on the free fatty acids from which the soap is derived, 5-25% by weight of a potassium builder salt, 0.2-1.5% by weight of sodiuni carboxymethylcellulose having a degree of substitution of at least 0.7 and a viscosity of between 20 and 100 cP at 20"C, 2-10% by weight of free potassium hydroxide, and 0-less than 50% by weight, based on the free fatty acids from which the soap is derived, of an anionic or nonionic synthetic detergent, said composition having a pH of above 11 (1% aqueous solution based on the composition on a dry basis) and a solids content of 32-40% by weight.

2. A composition according to claim 1, comprising 2-8% by weight of the potassium soap, the weight percentage being based on the free fatty acids from which the soap is derived, 10-20% by weight of the potassium builder salt, 0.5-1.0% by weight of the sodium carboxymethylcellulose, and 4-8% by weight of free potassium hydroxide.

3. A composition according to claim 1 or claim 2 wherein the synthetic detergent is a carboxylated nonionic.

4. A composition according to claim 3, further comprising a fluorescer and hexylene glycol or triethanol amine.

5. A composition according to any one of claims 1-5, further comprising 115% by weight of an alkali metal silicate.

6. A composition according to claim 6, comprising 1-5% by weight of an alkali metal silicate.

7. A composition according to any one of claims 1-7, wherein the potassium builder salt is a potassium ortho, pyro- or polyphosphate, carbonate or borate.

8. A composition according to claim 7 wherein the potassium builder salt is pentapotassium tripolyphosphate.

9. A process for the preparation of a composition according to claims 1-8, in which the potassium soap, the potassium builder salt and all or part of the potassium hydroxide are added last to an aqueous mixture of the other ingredients.

10. A composition or process as claimed in any one of claims 1-9, substantially as described before with particular reference to the Example.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. % by weight and the solids content (in 1% by weight) 37.5 36.7 These products were prepared as follows: The hexylene glycol or triethanol amine and the lauryl (poly-l-oxapropene)oxaethane carboxylic acid were added to 18% by weight of softened water. Subsequently the fluorescer was added, and the mixture stirred until the fluorescer was completely dissolved. Then the balance of the water was added, and subsequently the CMC was stirred in until all lumps had disappeared. Thereafter the sodium xylene sulphonate and the coconut fatty acids were added, and the mixture stirred until it was homogeneous. Then the KOH was stirred in until the neutralization was complete, and finally the pre-dissolved potassium tripolyphosphate, and the alkaline sodium silicate were added. The products were clear, stable liquids. WHAT WE CLAIM IS:

1. An aqueous built liquid detergent composition, comprising 1-15% by weight of a potassium soap of a fatty acid having from 10-18 carbon atoms in the fatty acid radical, the weight percentage being based on the free fatty acids from which the soap is derived, 5-25% by weight of a potassium builder salt, 0.2-1.5% by weight of sodiuni carboxymethylcellulose having a degree of substitution of at least 0.7 and a viscosity of between 20 and 100 cP at 20"C, 2-10% by weight of free potassium hydroxide, and 0-less than 50% by weight, based on the free fatty acids from which the soap is derived, of an anionic or nonionic synthetic detergent, said composition having a pH of above 11 (1% aqueous solution based on the composition on a dry basis) and a solids content of 32-40% by weight.