GB2211197A - Detergent composition - Google Patents

Abstract

A non-bleach-containing aqueous liquid built detergent contains defined, amounts of protease, amylase, non-ionic surfactant, alkyl benzene sulphonate, silicate, sodium tripolyphosphate, sodium carboxymethyl cellulose, polyacrylate, borax, and a threshold sequestering agent.

Description

DETERGENT COMPOSITION The present invention relates to built liquid laundry detergents.

Built liquid laundry detergents have been disclosed previously. Thus GB 1 350 370, and GB 1 365 464 disclose such detergents. Although the detergents are known there is a need to provide liquid detergents having a high performance, particularly for those which do not contain bleach, which is commonly present in granular detergents.

According to the present invention a non-bleach-containing aqueous liquid built detergent comprises (a) a first water stable protease wash enzyme in an amount in the range 0.05 to 0.5Z by wt, (b) a second water-stable amylase wash enzyme in an amount in the range 0.6 to 1.2Z by wt, and wherein the weight ratio of the said enzymes is in the range 6:1 to 2::1, (c) a non-ionic surfactant which is an alkoxy derivative of a long chain alkanol in an amount in the range 0.6-1.2Z wt of active material, (d) a soluble salt of an alkyl benzene sulphonate, wherein the alkyl group has from 9 to 15 carbon atoms, in an amount in the range corresponding to 11% to 17Z by wt of active material, (e) an alkali metal soluble silicate corrosion inhibitor in an amount in the range 2.5% to 4.0% by wt, (f) sodium tripolyphosphate in an amount in the range 8.0 to 12% by wt, (g) sodium carboxymethyl cellulose in an amount corresponding to 0.3Z to 0.7Z by wt of active material, (h) an ammonium and/or alkali metal salt of a polyacrylic acid in an amount corresponding to 3Z to 5Z by wt of active material, (i) borax in an amount corresponding to 3Z by wt of the decahydrate material, and (j) a threshold sequestering agent in an amount corresponding to 0.1 to 1Z by wt of 33Z active material.

The aqueous liquid detergent preferably also contains up to 0.5Z of sodium xylene sulphonate eg 0.1 to 0.5Z and up to 0.6Z of a clay eg 0.1 to 0.6Z, preferably a smectite clay, more preferably a bentonite clay.

The detergent may also contain other components which do not contribute to washing performance but which may be required for other reasons such as perfumes and dyes.

The water-stable protease and amylase enzymes are commercially available materials. Stability in the presence of water may be obtained by encapsulating the enzymes.

The non-ionic surfac'tant is preferably a derivative of an alkanol which alkanol has from 10 to 18, preferably 12 to 18, carbon atoms in the molecule. The non-ionic surfactant may be derived from mixtures of alkanols having the preferred number of carbon atoms in the molecule. The alkanol may for example be a primary unbranched alkanol having an alkyl group only on the carbon atom linked to the hydroxy group.

The alkanol is preferably condensed with 4 to 15 molar proportions of ethylene oxide. Such non-ionic surfactants are commercially available under the trade names wDobanol (Shell), Lutensol (BASF), "Synperonics" (ICI).

The preferred alkyl benzene sulphonate is sodium dodecyl benzene sulphonate (sodium DBS). The concentration of active material in any commercially available product available to a detergent formulator may vary. Amounts of alkyl benzene sulphonate in the formulation have been calculated on the basis of the amount of active material present.

The preferred sodium silicate corrosion inhibitor is a silicate having the formula SiO2:M20 wherein M is either sodium or potassium or mixtures thereof and the molar ratio of SiO2:M20 is from 1.6:1 to 4:1.

As the sodium tripolyphosphate (STPP) is present in an aqueous solution, the form of the tripolyphosphate used is one having a good solubility in the liquid composition.

The polyacrylate is preferably derived from a polyacrylic acid hgaving a MW in the range 40,000-1,000,000, more preferably 50,000-70,0000.

Any of the commercially available optical brighteners which are stable in the aqueous composition can be used.

The sequestering agent is a threshold sequestering agent.

Examples of suitable sequestering agents are EDTMP (ethylene diamine tetramethylene phosphonic acid), ETPMPD (diethylene triamine pentamethylene phosphonic acid), NTA (nitrilotriacetic acid, EDTA (ethylene diamine tetra acetic acid), as their ammonium or alkali metal salts.

The clay is preferably a bentonite clay. The clay preferably has a low iron content so as to give a light-coloured clay.

The remainder of the composition preferably consists of water.

The invention will now be described with reference to the following Examples.

In all the following Examples the detergent formulation was tested as follows. Samples were selected from six commercially available pre-stained cloths, these were: EMPA cotton 101 EMPA polyester/cotton 104 Krefeld cotton lOc Krefeld polyester/cotton 20c EMPA Red wine 114 EMPA Blood/milk/ink 116 The samples were washed in a four pot Terg-o-tometer (Trademark) testing apparatus (only 3 pots used). The cloths were distributed between the pots as follows: Pot 1 101, 104, 10c, 20c Pot 2 101, 104, 114, 116 Pot 3 lOc, 20c, 114, 116 The water used in the washing tests was 35 degree French hardeness (i.e. on the scale used to measure water hardness in France) and contained calcium and magnesium ions in the weight ratio of 85:15.

Each detergent formulation used was tested at two temperatures namely 400C and 60-C. The quantity of liquid detergent used was 5g/l of washing water. The wash time- was 15 minutes. Percentage stain removal was determined from measurements of reflectance values obtained before and after washing. The reflectance values were measured using a standard light reflectance meter (an Elrepho Datacolor 2000 reflectance meter). The measurements after washing were carried out on cloths which had been ironed flat.

The percentage stain removal (ZR) was calculated from XR - A - B x 100 C-B where A - reflectance after washing B - reflectance before washing C - reflectance of the unwashed cloth not treated with stain.

A rating for overall detergency at 40- and 60iC(OD40/6o) was calculated as follows: OD40/60 - 0.33 x 0D40 + 0.67 x OD60. The overall detergencies at 40iC (OD40) and 60-C (OD60) were determined from mean values of stain removals for cotton (M1) (obtained for cloths 101 and 10c), copolyester/cotton (M2) (obtained from cloths 104 and 20c), protein (M3) (obtained from cloths 116 and bleachable stains (M4) (obtained from cloth 116.The mean percentage stain temovals for various stain types were multiplied by weighting factors to give overall detergencies at the two individual temperatures according to the following formulae: OD40 - 0.16 M1 + 0.48 M2 + 0.18 M3 + 0.18 M4 OD60 - 0.26 M1 + 0.43 M2 + 0.17 M3 + 0.14 M4 ExamPles 1-4 and Comparative Test A The detergent formulations used in the above Examples and in the Comparative Test are set out in Table 1.

Table 1

Examples Component 1234A 1 2 3 4 A Protease 0.16 0.14 0.12 0.11 0.17 Amylase 0.08 0.04 0.02 0.02 0.08 Non-ionic surfactant 0.88 1.09 1.01 0.84 1.59 Sodium DBS 13.60 14.46 15.70 15.29 11.34 Sodium disilicate 2.82 2.88 3.02 2.50 2.54 STPP 9.81 9.90 10.00 9.97 6.91 CMC 0.53 0.57 0.58 0.88 0.88 Sodium polyacrylate 4.31 4.51 5.53 4.89 5.28 Borax 2.81 2.77 2.67 2.74 3.73 DETPMP, sodium salt 0.38 0.37 0.35 0.35 0.53 Bentonite clay 0.21 0.36 0.45 0.50 - Minors e.g. perfume to balance Water 0 to balance NB. (i) enzymes are quoted on an "as supplied" basis.

(ii) all other materials quoted on a 100% active basis.

Minors include perfume, OBA, hydrotrope (SXS), and any sodium sulphate or other salts produced by neutralisation of components.

The protease was "Esperase" 16 SL, Type W.

The amylase was "Termamyl" 400 SL, Type W. Both enzymes are encapsulated so as to be stable in water.

The non-ionic surfactant was an ethylene oxide derivative having an average 9 ethylene oxide groups in the molecule and derived from a mixture of C12-C15 alkanols.

"Sodium SUBS" was sodium dodecyl benzene sulphonate.

STPP is sodium tripolyphosphate.

"Sodium CMC" was sodium carboxymethyl cellulose.

The sodium polyacrylate is a salt of an acid having an average molecular weight of 60,000.

The OD40/60 values for Examples 1-4 were respectively 53.20, 54.40, 55.50, and 53.50. The value for the formulation (not according to the invention) of Comparative Test A was 48.8.

Claims (12)

1. A non-bleach-containing aqueous liquid built detergent which comprises (a) a first water stable protease wash enzyme in an amount in the range 0.05 to 0.5Z by wt, (b) a second water-stable amylase wash enzyme in an amount in the range 0.6 to 1.2X by wt, and wherein the weight ratio of the said enzymes is in the range 6:1 to 2::1, (c) a non-ionic surfactant which is an alkoxy derivative of a long chain alkanol in an amount in the range 0.6-1.2X wt of active material, (d) a soluble salt of an alkyl benzene sulphonate, wherein the alkyl group has from 9 to 15 carbon atoms, in an amount in the range corresponding to 11% to 17Z by wt of active material, (e) an alkali metal soluble silicate corrosion inhibitor in an amount in the range 2.5Z to 4.0Z by wt, (f) sodium tripolyphosphate in an amount in the range 8.0 to 12Z by wt, (g) sodium carboxymethyl cellulose in an amount corresponding to 0.3Z to 0.7Z by wt of active material, (h) an ammonium and/or alkali metal salt of a polyacrylic acid in an amount corresponding to 3Z to 5Z by wt of active material, (i) borax in an amount corresponding to 3X by wt of the decahydrate material, and (j) a threshold sequestering agent in an amount corresponding to 0.1 to 1Z by wt of 33Z active material.

2. A detergent according to claim 1 which contains 0.1 to 0.5Z of sodium xylene sulphonate.

3. A detergent according to either one of the claims 1 or 2 which contains 0.1 to 0.6Z by weight of a clay.

4. A detergent according to claim 3 wherein the clay is a smectit clay.

5. A detergent according to claim 4 wherein the clay is a bentonite clay.

6. The process according to any one of the proceeding claims wherein the non-ionic surfactant is a derivative of an alkanol, which alkanol has from 10-18 carbon atoms in a molecule.

7. A detergent according to claim 6 wherein the alkanol has 12-18 carbon atoms in a molecule.

8. A detergent according to any one of the proceeding claims wherein the alkanol is a primary unbranched alkanol having an alkyl group only on the carbon link to the hydroxy group.

9. The detergent according to any one of the proceeding claims wherein the alkanol is condensed with 4-15 molar proportions of ethylene oxide.

10. The detergent according to any one of the proceeding claims wherein the alkyl benzine sulphonate is sodium dodecyl benzene sulphanate.

11. The detergent according to any one of the proceeding claims wherein the sodium silicate corrosion inhibiter is a silicate having the formula Si2:M20 where M is either sodium or potassium or mixtures thereof and the molar ratio of Si02:H20 is from 1.6:1 to 4:1.

12. The detergent according to any one of the proceeding claims wherein the remainder of the composition, apart from any components which do not contribute to washing performance, is water.