GB2099013A - Built detergent bars - Google Patents

Abstract

Built detergent bars for cleaning fabrics and surfaces have improved bar hardness, rate of wear (in use) and mushing characteristics by generating alumino-silicate in situ.

Description

SPECIFICATION Manufacture of detergent bars Field of the invention This invention relates to improved built detergent bars. These products, used for fabric washing and cleaning surfaces, should have certain properties to allow efficient manufacture and performance of the required functions.

The bars must have acceptable physical strength to ensure their structural integrity is retained during handling, transport and use.

Commercial built detergent bars contain detergent active and detergent builder materials together with optional components, for example abrasives, fillers, perfumes, alkaline salts and bleaching agents.

General description of the invention The invention provides an improvement in built detergent bars 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 bar processing and properties can be improved by mixing precursors for alumino-silicate with the bar components during the mixing stage or stages so that alumino-silicate is formed in situ. The formation will begin when the precursors are in the mixture but a substantial proportion of the reaction will occur after the product has been made in bar form.

The amount of alumino-silicate which is effective in improving the bar properties is about 1% to about 20% and will preferably be above about 2% and preferably up to about 10% by weight of the bar.

In general the incorporation of the alumino-silicate improves the bar structure as demonstrated by improved hardness, rate of wear and mush characteristics. The benefit provided by the invention will be dependant on the formulation to which it is applied.

The alumino-silicate precursor systems used are not critical but it will be necessary to select the system which provides the desired in situ reaction in the conditions of manufacture. It is necessary to mix the alumino-silicates components in the presence of excess alkali to ensure the desired reaction occurs without aluminium ions remaining in the product.

A preferred system is a soluble aluminium salt, for example aluminium sulphate, and sodium silicate, the latter is usable in the neutral or alkaline form. Other aluminium salts which can be used are the chloride and nitrate. Alumino-silicate can also be prepared by reaction of sodium aluminate and alkaline or neutral silicate. In general the precursors will be used in stoichiometric amounts but some variation is allowable provided the aluminium precursor is not in excess.

The use of alumino-silicates formed in situ as described is of particular value for certain non-soap detergent actives, whether alone or in mixture with other actives. The present invention is of particular value when mixtures of non-soap detergent actives are present in the formulation because such mixture will often have properties adversely different to the individual materials.

Bars containing a proportion, usually at least 5%, of primary alcohol (C8 to C22) sulphates are friable and can be improved by forming alumino-silicate in situ. When primary alcohol sulphonates are mixed with other actives, for example branched or linear alkyl-benzene sulphonates, the bars are not of sufficient hardness and suffer from a degree of friability.

Bars containing linear alkyl benzene sulphonates in an amount above about 30% of total active can be hardened, the presence of this active generally results in physically soft bars, and the rate of wear reduced.

Branched alkyl benzene sulphonates usually provide bars with suitable properties, but the bars can be soft if a proportion of non-detergent organic material, for example above about 1.5%, remains due to incomplete formation of the active, or if a proportion of soap, i.e. up to about 30%, is present.

The use of the process of the present invention improves these bars.

The presence of in situ generated alumino-silicate in all of the above bar types results in reduction of rate of wear and improvements in mush characteristics.

The primary alcohol sulphates to which this invention relates have the formula: R-OSO3M wherein B is a branched i.e. derived from petroluem or straight chain alkyl group containing from 8 to 22 carbon atoms and M is a cation providing water soluble properties for the salt. M will usually be selected from ammonium and sodium, the latter being that used generally. The OSO3 group will be attached at a primary position in the alkyl group.

The linear alkyl benzene sulphonates have the formula: R'-C6H4SO3M wherein R' is a linear alkyl group containing 7 to 1 5 carbon atoms, C8 H4 is a benzene nucleus and M is potassium ammonium or sodium, the latter being that used generally.

Components for the formulation: Detergent 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 II by Schwartz, Perry and Berch (Interscience 1958). The detergent actives usable in the present invention may be found in the general classes of anionic, nonionic, amphotetic, betaine and zwitterionic actives. Specific examples of detergent active are primary alcohol sulphates, linear alkyl benzene sulphonates, alkane sulphonates, secondary alcohol sulphates, branched alkyl benzene sulphonates, alkyl sulphonates, 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 carboxy-methyl 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, flurescors, opacifiers, germicides, perfumes, bleaching agents and fillers, for example sodium sulphate, talc, calcite and bentonite, are optionally present.

Prior literature UK 6,884,466 (Unilever) describes the rapid chilling of a liquid filled soap containing an alumino silicate gel. The present application is directed to built detergent non-soap detergent bars which are manufactured by usual commercial techniques without the use of a rapid chilling step.

Specific description of the invention Bars were prepared and subjected to tests to determine the penetration and rate of wear properties. The former is a measure of the bar hardness.

Penetration test: The penetrometer used was a SUR type PNR 8 (Sommer und Runge of Berlin DBR). The needle had a point angle of 90 10' and was forced into a plane bar surface under a total load of 200 g for 10 seconds. The penetration depth was recorded in millimetres.

Rate of wear test: A cloth was placed on a smooth surface which was inclined to extend below the surface of water in a trough. A detergent bar was placed on the cloth, contacting it at a face having an area of 5 cm by 3 cm the long dimension positioned across the slope. The bar was moved up and down the plane under a force of about 1 90 g tracing a depth of 6.5 cm of which about half extended below the water level.

The bar was subjected (for products 1 to 10) to 125 or 1 75 cycles (a cycle being two strokes, one in each direction) with a new cloth being used for each period of 25 cycles. Products 11 et seq were tested at 1000 cycles.

The loss in weight after the bar had been dried at ambient overnight is the rate of wear (R) in grms.

Mush test: An identified area on a bar was immersed in water at 200C or 300C for 6 hours. The mush formed was scraped off and the bar dried at 400C overnight and weighed. The weight loss due to the mush removed is expressed as weight lost per 50 sq cm. (grms).

Examples: Examples of the process and product of the invention will now be given to illustrate but not limit the invention. The general process used will first be described.

Aluminium sulphate hexadecahydrate (0.74 Kg) and water (0.2 Kg) were added to sodium neutral silicate solution (1.1 Kg32%) in a mixer and stirred for 10 minutes. Then anhydrous sodium carbonate (1 Kg) was added and the whole stirred for another 10 minutes. Sodium primary alcohol sulphate containing 94% of active material and obtained by sulphating coconut alcohol, (2.98 Kg) was added and the whole mixed for 5 minutes. Calcite (2.0 Kg) and sodium carboxymethyl cellulose (degree of substitution 0.65) (150 g) were added followed by another mixing period of 5 minutes.

Finally, sodium pyrophosphate (1.6 Kg) was added and the whole mixed for 10 minutes before milling and plodding to form extruded bars. These products were then subjected to tests to determine the appropriate properties.

This manufacturing procedure can also be utilised for products containing other actives, for example linear alkyl benzene sulphonates but substituting the appropriate weight. However, if the product is manufactured from the acid form of the active the alumino-silicate precursors must be added when neutralisation is substantially complete and in the presence of excess alkali.

A number of formulations were prepared and examined for penetration, rate of wear and mush.

Each product contained (calculated as anhydrous material) sodium carbonate 10%, sodium pyrophosphate 16%, sodium carboxy methyl cellulose 1.5% and calcite was added to provide a balance to 100%. For product 9 and 10 the balance was provided by adding sodium sulphate not calcite at the appropriate stage. The linear alkyl benzene sulphonic acid was obtained from Nissan Conoco a Japanese company under the trade name Nalken N600.

The formulations are shown in the Tables as % by weight of the anhydrous components.

These results demonstrate the properties of built detergent bars are improved by forming an alumino-silicate in situ.

The products, whose composition and properties, are provided on the Tables were prepared by methods comparable to that quoted for Table I. In Tables II to V the detergent actives used are abbreviated as follows: PAS - primary alcohol sulphate ABS - alkyl benzene sulphonate FAES - fatty acid ester sulphonate.

The hardness measurements are quoted as penetration (mm) at the times: A - immediately after extrusion B - after 1 day C - after 1 week.

Table II (products 11 to 17) provides information on PAS containing formulations, one in admixture with branched ABS. Products 11 to 1 6 utilised the sulphate detergent active as the feedstock while product 1 7 used the acid. For this product the sulphonic acid was neutralised with caustic soda before addition of the carbonate. Products 11 and 1 5 are included as controls. The results demonstrate that some or all of the properties of the bars are improved by the generation of alumino-silicate in situ. The precursors were added separately or together and reacted in the alkaline environment of the mixture.

Table Ill (products 18 to 23) discloses paired comparisons of PAS containing formulations.

Control formulations 1 8, 20 and 22 in general do not have properties better than the formulations of the invention. The controls will have commercially acceptable hardness after 1 day or 1 week but the firmer product obtained from the plodder with the presence of alumino-silicate assists handling immediately after extrusion.

Table IV provides information on FAES containing bars with products 24 and 26 as control. The FAES bars are relatively soft at extrusion but harden to a satisfactory level after 1 day. The use of alumino-silicate formation in situ provides a firmer bar more satisfactory for handling immediately after extrusion.

The ABS (branched) used in products 28 and 29 contained 2.5% non-detergent organic material.

Table V relates to ABS (linear) formulations and compares four products (33 to 36) with control product 32. The improvement in the properties of wear, hardness and mush can be appreciated.

Table I Component Product 1 2 3 4 5 6 7 8 9 10 Branched alkyl(C12) benzene sulphonate 28 Nil Nil Nil Nil Nil 8 8 30 30 Primary alcohol (coconut) sulphate Nil 28 28 28 Nil Nil 20 20 Nil Nil Linear alkyl (C12) benzene sulphonate Nil Nil Nil Nil 28 28 Nil Nil Nil Nil Water 6.5 12.3 15.3 12.0 6.5 7.9 6.5 8.1 6 6 Aluminium sulphate Nil Nil 4.0 Nil Nil 4.0 Nil 2.1 Nil 2.1 Sodium aluminate (65% solution) Nil Nil Nil 2.9 Nil Nil Nil Nil Nil Nii Neutral sodium silicate Nil Nil- 4.2 13.00 Nil 4.2 Nil 2.1 Nil 2.0 Rate of wear 175 cycles 3.00 6.3 4.7 3.5 5.1 3.7 3.0 Rate of wear 125 cycles 2.00 4.5 3.4 Penetration at extrusion 12.00 15.0 8.3 14.0 6.8 12.0 5.8 after 1 day 2.8 13.5 4.1 4.0 3.5 2.8 2.1 after 2 weeks 2.5 10.4 3.3 2.72 2.03 2.5 1.6 Weight loss (mush) 10.0 9,0 Table II Components Product 11 12 13 14 15 16 17 PAS 28 28 28 31 29.5 31 28 Branched ABS - - - - 1.5 - Pyro phosphate 16 16 16 6 10.0 6 16 Triphosphate - - - 2 - 2 Carbonate 10 10 10 18 18.0 18.0 10 Aluminium sulphate - - 4.0 - 4.0 2.2 4.0 Sodium aluminate - 2.9 - - - - - Alkaline silicate - - - - 2.9 2.9 Neutral silicate - 15.5 4.1 - - - 4.9 Calcite 32 12.0 23.0 18 5.2 20.7 26 Kaolin - - - 9 9 - Bentonite - - - 2 2 - Urea 2 - 2 2 - 4 Water 10.3 15.0 10.3 10.3 15.3 8.9 10.3

Rate of wear : 200C 40.4 31 22.8 37.3 28.8 28.4 24.2 @30 C 26.8 18.44 23.0 27.9 21.5 23.8 - A 11.0 6.2 7.18 10.5 11.7 9.5 8.7 Hardness # B 1.1 0.9 0.9 1.3 1.9 1.0 1.0 @C 0.7 0.7 0.5 1.0 0.7 0.9 0.8 20 C 30.5 16.3 16.9 19.7 17.7 16.3 16.4 Mush # 30 C 32.3 17.4 16.5 25.5 16.2 16.5 15.8 Table III Components Product 18 19 20 21 22 23 PAS 15.5 15.5 14.0 14.0 7.0 7.0 Branched ABS 15.5 15.5 - - - - ABS (linear) - - 14.0 14.0 21.0 21.0 Pyrophosphate 10 10 16 16.0 16.0 16.0 Triphosphate - - - - - - Carbonate 18 18 10 10 10.0 10.0 Aluminium sulphate - 4.0 - 2.0 - 3.0 Alkaline silicate - 2.9 - 1.55 - 2.2 Calcite 31.0 13.0 38 34 37.1 32.1 Kaolin - 9.0 - - - - Bentonite - - - - - - Urea - - - - - Water 7 10.3 6.5 7 7.5 7.5 Rate of wear 200C 13.4 8.1 29.8 26.4 27.2 24.7 300C 32.5 23.2 26.4 22.4 27.3 17.8

A A 16.0 8.8 11.1 8.6 16.0 7.3 Hardness CB 1.0 1.0 3.5 2.4 4.5 3.2 C 0.4 0.8 1.2 1.2 3.4 2.4 Mush @20 C 39.4 15.9 18.4 12.0 18.3 10.5 1300C 45.3 14.9 24.0 14.9 25.3 13.6 Table IV Component Product 24 25 26 27 28 29 30 31 ABS (linear) - - - - - - 15.5 15.5 FAES (coconut) 31 31 15.5 15.5 - - - - Branched ABS - - 15.5 15.5 31 31 15.5 15.5 Pyro phosphate 6 6 6 6 6 6 6.0 6.0 Triphosphate 2 2 2 2 2 2 2.0 2.0 Carbonate 18.0 18.0 18.0 18.0 18 18 18.0 18.0 Aluminium sulphate - 4.0 - 4.0 - 4 - 3.5 Alkaline silicate - 2.9 - 2.9 - 2.9 - 2.6 Calcite 22.0 13.3 22.3 9.9 23.7 12.8 23.8 14.1 Kaolin 9 9 9 9 9 9.0 9.0 9.0 Bentonite 2 2 2 2 2.0 2.0 2.0 2.0 Water 6 1.5 6 11.5 6.0 9.7 6.0 8.6

Rate of wear @20 C 44.0 29.2 42.8 32.4 17.5 7.0 35.4 21.5 @30 C 44.3 35.4 43.1 32.8 21.8 19.5 34.5 17.8 A 17.7 5.6 16.4 3.9 14.0 5.9 19.7 5.0 Hardness B 0.05 0.05 3.8 1.5 1.3 0.5 5.6 1.5 C 0.05 0.05 3.0 1.2 1.3 0.5 5.4 1.4 20 C 41.5 19.4 38.5 15.7 10.5 7.3 14.6 7.4 Mush # 30 C 43.0 15.5 39.5 16.5 12.8 8.4 13.5 8.4 Table V Component Product 32 33 34 35 36 Linear ABS 31.0 28.0 31 28.0 31.0 Pyro phosphate 6.0 - 6 - 6 Triphosphate 2.0 16.0 2 16.0 2.0 Carbonate 18.0 10.0 18 10.0 18.0 Aluminium sulphate - 3.3 3.3 - 4.0 Sodium aluminate - - - 2.9 Alkaline silicate - 2.5 - 5.00 2.9 Neutral silicate - - 3.8 - Calcite 24.6 20.0 15.3 27.1 14.9 Kaolin 9.0 9.0 9.0 - 9.0 Bentonite 2.0 - 2.0 - 2.0 Water 6.0 9.5 7.6 7.9 8.4

Rate of wear 200C 39.0 24.2 31.2 31.4 28.4 300C 35.3 26.9 24.2 21.2 23.8 A 19.2 4.4 5.9 9.4 5.3 Hardness @ B 8.7 2.4 4.1 4.5 3.3 8A 8.4 1.5 2.9 2.8 2.8 Mush 200C 15.1 8.3 8.0 11.3 10.13 300C 14.3 12.8 9.2 12.0 11.3

Claims (22)

Claims

1. A method of manufacturing a built detergent bar comprising from about 5% to about 45% by weight of non-soap detergent active material and from about to about 60% by weight of detergent builder material wherein the bar components are mixed and formed into bars characterised in that precursors for alumino-silicate are mixed with the bar components during the mixing stage or stages in an alkaline environment so that alumino-silicate is formed in situ.

2. A method according to claim 1 wherein the precursors are added in amounts sufficient to provide from about 1% to about 20% of alumino-silicate in the bar.

3. A method according to claim 2 wherein the amount of alumino-silicate formed is at least about 2%.

4. A method according to any preceding claim wherein the precursors are a water soluble salt of aluminium and an alkali metal silicate.

5. A method according to any preceding claim wherein the detergent active is present in an amount from about 10% by weight.

6. A method according to any preceding claim wherein the detergent active is selected from primary alcohol (C8 to C22) sulphates and mixtures of this active with other actives.

7. A method according to any of claims 1 to 5 wherein the detergent active is selected from linear alkyl (C7 to C15) benzene sulphonates and mixtures of this active with other actives.

8. A method according to any one of claims 1 to 5 wherein the detergent active is selected from fatty acid (C8 to C22) ester (C, to C4) sulphonates and mixtures of this active with other actives.

9. A method according to any of claims 1 to 5 wherein the detergent active is a branched alkyl (C7 to C15) benzene sulphonate containing at least about 1.5% non-detergent organic material or a proportion of soap.

10. A method according to claim 4 wherein the precursors are aluminium sulphate and a sodium silicate.

11. A method according to any preceding claim wherein the components are, after mixing, milled and plodded to form bars.

12. A built detergent bar 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 detergent builder material characterised in that the bar includes alumino-silicate formed in situ in an amount effective to improve the bar properties.

13. A built detergent bar according to claim 1 2 wherein the alumino-silicate is present in an amount of from about 1 % to about 20% by weight.

14. A build detergent bar according to claim 12 wherein the alumino-silicate is present in an amount of at least about 2% by weight.

1 5. A built detergent bar according to any preceding claim wherein the detergent active is present in an amount of from about 10% by weight.

1 6. A built detergent bar according to any preceding claim wherein the detergent active is selected from primary alcohol (C8 to C22) sulphates and mixtures of this active with other actives.

17. A built detergent bar according to any preceding claim wherein the detergent active is selected from linear alkyl (C7 to Ca5) benzene sulphonates and mixtures of this active with other actives.

1 8. A built detergent bar according to any preceding claim wherein the detergent active is selected from fatty acid (C8 to C22) ester (C, to C4) sulphonates and mixtures of this active with other actives.

1 9. A built detergent bar according to any preceding claim wherein the detergent active is a branched alkyl (C7 to Ca5) benzene sulphonate containing at least about 1.5% organic material or a proportion of soap.

20. A method of manufacturing a built detergent bar according to claim 1, substantially as herein described.

21. A built detergent bar according to claim 12, substantially as herein described.

22. A built detergent bar manufactured by the method of claims 1 to 11.