GB2161173A

GB2161173A - Detergent bars

Info

Publication number: GB2161173A
Application number: GB08516602A
Authority: GB
Inventors: Peter James Powers
Original assignee: Unilever PLC
Current assignee: Unilever PLC
Priority date: 1984-07-03
Filing date: 1985-07-01
Publication date: 1986-01-08
Also published as: GB8516602D0; IN163033B; MY102538A; PH20219A; OA08054A; BR8503109A; GB2161173B; GB8416878D0

Abstract

The lather properties of built detergent bars containing primary alcohol sulphate surfactants are increased by the presence of an alkanolamine component.

Description

SPECIFICATION Detergent compositions Field of Invention This invention relates to improved detergent bar compositions. These products, used for fabric washing and cleaning surfaces, should have certain properties to provide efficient performance of the required functions.

The invention is directed to improving the lather characteristics of such compositions, containing primary alcohol sulphate as the major detergent active.

Commercial built detergent bar compositions contain detergent active and detergent builder materials together with optional components, for example abrasives, fillers, perfumes, aikaline salts, for example silicates, and bleaching agents.

General Description of the Invention The invention provides an improvement in built detergent bar compositions comprising from about 5% to about 45% by weight of non-soap detergent active material and from about 5% to about 60% by weight of detergency builder. The invention is specifically directed to detergent bar compositions containing at least about 10% by weight of primary alcohol sulphates; these detergent actives have the general formula R-OSO3M where R is branched, i.e. derived from petroleum, or straight-chain alkyl group containing from 8 to 22 carbon-atoms. M is a cation providing water-soluble properties for the detergent active and will usually be selected from ammonium, potassium and sodium with the latter being the cation used generally. The sulphate group will be attached at a primary position in the alkyl group.The invention is specifically beneficial when the level of primary alcohol sulphate is above about 15% by weight of the composition and, more particularly, above about 20% by weight. Preferably the level of primary alcohol sulphate in the composition is not more than about 35% by weight.

The applicants have found the lather obtained with primary alcohol sulphate-containing bar compositions is labile, particularly when notably hard water is used to prepare the detergent liquor and when the composition is used at relatively low concentrations. It has been found that incorporation of an alkanolamine component in bar compositions containing primary alcohol sulphate improves the lather characteristics of the composition and the alkanolamine component will be present at a level above about 0.5% by weight of the composition provided the amount of alkanolamine component is equivalent to not less than 15% molar relative to the amount of primary alcohol sulphate anion present.

The alkanolamine component may be introduced into the bar composition as a separate additive during processing or it may be utilised as a neutralisation component for the primary alcohol sulphuric acid after formation. This latter route introduces the alkanolamine component as the cation species of the detergent active.

Preferably the amount of alkanolamine component is not less than about 25% molar, more preferably not less than about 50% molar, relative to the amount of primary alcohol sulphate anion. The amount of alkanolamine component is preferably not more than about 60% molar relative to the amount of primary alcohol sulphate anion. Above this molar ratio the bar composition may be physically soft with a high rate of wear. Thus although the applicants associate certain product benefits with the use of alkanolamine components, this component should be used in association with other usual cationic species, e.g. potassium, sodium and ammonium, to obtain the desired physical product properties.

The alkanolamine, may be of the mono, di or tri form but is preferably a mono-alkanolamine; the alkanol radical used may contain up to four atoms. Monoethanolamine is a preferred component, diethanolamine and triethanolamine are preferred components in their classes.

The presence of the alkanolamine component above a level of about 4% by weight is not excluded by the present invention, but use of levels above this may provide, depending on the other bar components, a physically soft bar with a relatively high rate of wear. Preferably the level of alkanolamine is not more than about 2.5% by weight of the composition.

With normal home use built laundry bars generate a low product concentration on the fabric surface when the laundry bar is first used in contact with it. Althoug the active concentration increases during the use cycle, in the initial stages the product provides a poor lather generation. It will be understood that while the low product concentration is an inherent result of the product form and its manner of use, this feature is not present with a powder composition because the latter is added to a water supply to form the wash liquor in one step. The invention is applicable to built laundry bars containing primary alcohol sulphates which could be used in areas of relatively hard water and/or at low active concentrations.

Components Detergents active and builder components are well characterised in detergent bar technology.

These components are described in "Surface Active Agents" by Schwartz and Perry (Interscience 1949) and volume ll by Schwartz, Perry and Berch (Interscience 1958). The detergent actives usable in the present invention in admixture with primary alcohol sulphates may be found in the general classes of anionic, nonionic, amphoteric, betaine and zwitterionic actives.

Specific examples of detergent actives are linear alkyl benzene sulphonates, alkane sulphonates, secondary alcohol sulphates, branched alkyl benzene sulphonates, alkyl sulphates, olefin sulphonates, monocarboxylic acid salts, ethoxylated alcohols and fatty acid ester sulphonates.

Examples of builder components are: water soluble phosphate salts, e.g. sodium tripolyphosphate, pyrophosphate and orthophosphate; water soluble carbonates, e.g. sodium carbonate, organic builders, e.g. sodium nitrilo triacetate, sodium tartarate, trisodium carboxymethyl oxysuccinate, sodium oxydisuccinate and sodium sulphonated long-chain monocarboxylic acids; ion exchange materials, for example alumino-silicates.

Other ingredients, for example silicates, e.g. sodium alkaline silicate, starch, sodium carboxymethyl cellulose, colouring materials, fluoroescers, opacifiers, germicides, perfumes, bleaching agents and fillers, for example sodium sulphate, talc, calcite and bentonite, are optionally present.

Prior Literature US 3738935 (Chevron) describes the addition of a trialkanolamine to reduce surface blemishes of bars containing soap and olefin sulphonates.

UK 2106929 (Kao) describes detergent bars containing alkyl sulphate and fatty acid ethanolamide.

In UK 583028 Novag uses the reaction product of sulphuric acid and a long chain alcohol in a wax containing washing bar; tri-ethanolamine is quoted as an ingredient.

Specific Description of the Invention The compositions of the present invention will preferably be formulated to provide a pH in aqueous solution, when dissolved at a level of 2 grammes per litre, sufficient to ensure at least 50% of the alkanolamine component is in cationic form. A number of examples were performed on the basis that the use of monoethanolamine at a level of 5% by weight of a detergent bar composition is approximately the stoichiometric cationic concentration equivalent to a level of 25% primary alcohol sulphate anion in the composition.

The improvement in lather efficiency was demonstrated using a standard detergent composition in both unsoiled and soiled detergent liquors. The soiled liquor contained sebum at a level of 0.5 grammes per litre. The control formulation contained sodium primary (coco) alcohol sulphate 25%, sodium pyrophosphate 22%, sodium carbonate 10%, calcite filler 33%, water 10%. Two levels of monoethanolamine, 1% and 3.5% by weight, were dosed onto this base formulation with corresponding reduction of the calcite filler level.

The foam height (centimetres) at times from zero to 5 minutes was measured after generation using both 20 and 40 French hard water.

The foam generated by manually shaking (fifty times) 25 ml aliquots of detergent solution in stoppered graduated cylinders. The results are given in the following table: System/Product Foam Height (cm) at Time (mins) 0 1 2 3 4 5 200FH/clean: Product dosage 1.5/lit A Control 30.0 30.0 26.5 25.0 23.5 22.0 B Control +18 35.0 35.0 35.0 35.0 35.0 35.0 C Control +3.5% 35.0 35.0 35.0 35.0 35.0 35.0 20 FH/soiled (sebum): Product dosage 2.Og/lit A 17.0 15.5 9.5 5.0 4.0 4.0 B 23.0 20.0 13.5 11.5 9.0 8.5 C 23.0 21.0 14.0 12.0 11.0 9.5 40 FH/clean: Product dosage 2.0g/lit A 17.0 12.0 9.5 7.0 6.0 6.0 B 24.0 15.0 14.0 11.0 10.0 8.5 C 26.0 23.0 18.0 16.5 15.0 8.5 400FH/soiled (sebum): : Product dosage 2.0grit A 13.0 1.0 0 C O 0 B 20.0 8.5 2.5 1.5 0 0 C 20.0 9. 5 2.5 1. 5 0 0 These results demonstrate the presence of an alkanolamine component provides increase in lather initially and reduces the rate of decay after formation.

Claims

1. A built detergent bar composition intended for direct application containing from about 10% to about 45% by weight of non-soap detergent active material and from about 5% to about 60% by weight of detergency builder wherein the composition contains at least about 10% by weight of primary alcohol (C8 to C22) sulphate active, characterised in that the composition includes from about 0.5% by weight of alkanolamine component containing 2 to 4 carbon atoms in each alkyl group, provided the amount of alkanolamine component is equivalent to not less than 15% molar relative to the amount of primary alcohol sulphate anion present.

2. A composition according to claim 1 containing at least about 15% by weight of primary alcohol sulphate.

3. A composition according to claim 2 containing at least about 20% by weight of primary alcohol sulphate.

4. A composition according to any preceding claim wherein the level of primary alcohol sulphate is not more than about 35% by weight of the composition.

5. A composition according to any preceding claim wherein the level of alkanolamine component is not more than about 4% by weight of the composition.

6. A composition according to any one of claims 1 to 4 wherein the level of alkanolamine component is not more than about 2.5% by weight of the composition.

7. A composition according to any preceding clam wherein the amount of alkanolamine component is not less than about 25% molar relative to the amount of primary alcohol sulphate anion.

8. A composition according to claim 7 wherein the amount of alkanolamine component is not less than about 50% molar relative to the amount of primary alcohol sulphate anion.

9. A composition according to any preceding claim wherein the amount of alkanolamine component is not more than about 60% molar relative to the amount of primary alcohol sulphate anion.

10. A composition according to any preceding claim wherein the alkanolamine is a monoalkanolamine.

11. A composition according to any preceding claim wherein the alkanolamine is an ethanolamine.

12. A composition according to any preceding claim which provides a pH in aqueous solution, when dissolved at a level of 2 grammes per litre, sufficient to ensure at least 50% of the alkanolamine component is in cationic form.