CA1098409A

CA1098409A - Liquid detergent composition

Info

Publication number: CA1098409A
Application number: CA275,237A
Authority: CA
Inventors: Foscarina Pasztor-Rozzo; Arnold A. Keller
Original assignee: Unilever PLC
Current assignee: Unilever PLC
Priority date: 1976-04-01
Filing date: 1977-03-31
Publication date: 1981-03-31
Also published as: DE2713704C3; NL7703179A; DE2713704A1; GB1572606A; DE2713704B2; JPS5366909A

Abstract

C 543 (R) Abstract of the Disclosure An aqueous built liquid detergent composition with a high pH and increased solids content is obtained, using a potassium soap as the main detergent-active compound, as well as a potassium builder salt, sodium carboxymethyl-cellulose and free potassium hydroxide. The composition is suitable for laundering cotton in hard and soft water.

Description

1~ Q ~ ~9 The present invention relates to an aqueous built l:iquid detergent composition and more particularly to an aqueous built, highly alkaline liquid detergent composition w:ith 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 gen-erally of the type containing one or more synthetic surface-active agents, one or more water-soluble builder salts, and 10 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 15 to prepare more concentrated liquids without taking special steps and/or using special ingredients.
This is particularly true for liquid detergent compo-sitions 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 25 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 g ..

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`` lQ6a8~9 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 like 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 15 composition. Other detergent-active materials may also be present, such as nonionics, carboxylated nonionics, and anionics. Examples of the former are ethylene oxide conden-sation products of primary C8-C18 alcohols, such as Cg-Cll alcohol condensed with 6 moles of ethylene oxide; examples 20 o~ the second are alkyl(poly-l-oxapropene)oxaethane carboxylic acids such as lauryl(poly-l-oxapropene)oxaethane carboxylic acid. Examples of the latter are: alkylaryl sulphonates, alkane sulphonates, alkyl sulphates, alkylether sulphates, olefin sulphonates, etc. These additional detergent-active 25 materials are used in amounts less than half the amount of soap, preferably less than one third of the amount of soap.

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~0984~9 The potassium builder salts used according to the present invention are potassium salts, such as pentapotassium tripolyphosphate, tetrapotassium pyrophosphate and tripotassium orthophosphates. Other potassium salts may also be used, such as potassium carbonate r -borate and the like r but these are less preferred. Of the above builder salts, pentapotassium tripolyphosphate is the preferred one. This can be incorpor-ated 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. Alkaline silicates may also be present in the composition of the invention, e.g. sodium or potassium sili-cate, in an amount of 1-15%, 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 (Hoppler at 20C 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 , .
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obtained by the addition of potassium hydroxide. Sufficient potassium hydroxide should be added to neutralize acid c:omponents if present in the composition, and to provide for free potassium hydroxider 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, phosphate esters, a solvent such as hexylene ~lycol, 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 carboxy-lated 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, co-solvents and the like.
The compositions of the invention have a total solids content of 32-40~ by weight, are stable liquid laundry products, 25 and are suitable, e.g. for laundering cotton. They work both in soft and 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 ~a , , ;, : , , - . ~:
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the builder, and as the case may be part or all of the KOH, should be added to an aqeuous 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:
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- ~098~9 % by weight distilled coconut fatty acids 4 4 lauryl(poly-l-oxapropene)oxaethane-carboxylic acid0.5 0.5 sodium xylene sulphonate (90~)5.0 5.0 alkaline sodium silicate (40%)5.0 5.0 KOH (50%) 20.5 16.9 pentapotassium tripolyphosphate (50%) 28.0 28.0 Na CMC (DS 0.7 DP 150 visc. 25-32 cP)0.7 0.7 hexylene glycol 1.5 triethanol amine - 2.5 fluorescer (Blankophor ~ BBH 766, a diethanolamine-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%
aqeous solution) was: 12.1 12.1 and the solids content (in % 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 ccmpletely 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 sulphon-ate and the coconut fatty acids were added, and the mixture stirred until it was homogeneous. Then the KOH was - , ,:

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~'a8~9 stirred in until the neutralization was complete, and finally the pre-dissolved potassium tripoly phosphate, and the alkaline sodium silicate were added.
The products were clear, stable liquids.

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An aqueous built liquid detergent composition, comprising 1-15% by weight of a potassium soap of a fatty acid with 10-18 carbon atoms in the fatty acid radical, 5-25% by weight of a potassium builder salt, selected from the group consisting of potassium orthophosphate, tetrapotassium pyrophosphate, pentapotassium tripolyphosphate, potassium carbonate and potassium borate, 0.2-1.5% by weight of sodium carboxymethylcellulose having a degree of substitution of at least 0.7 and a viscosity of 20-100 cP at 20°C, and 2-10% by weight of free potassium hydroxide, said composition having a pH of above 11 (1% aqueous solution) and a solids content of 32-40% by weight.

2. The composition of claim 1, further comprising lauryl (poly-1-oxapropene)oxaethane carboxylic acid in an amount less than half the amount of the potassium soap.

3. The composition of claim 2, further comprising a fluorescer and hexylene glycol or triethanol amine.

4. The composition of claim 1, further comprising 1-15%
by weight of sodium or potassium silicate.

5. The composition of claim 1, wherein the potassium builder salt is pentapotassium tripolyphosphate.

6. A process for the preparing a composition as claimed in claim 1, wherein 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.