GB2287948A

GB2287948A - Laundry detergent composition

Info

Publication number: GB2287948A
Application number: GB9406542A
Authority: GB
Inventors: Michael Alan John Moss; Gerard Marcel Baillely; Alfred Busch; Christiaan Arthur Jacque Thoen
Original assignee: Procter and Gamble Co
Current assignee: Procter and Gamble Co
Priority date: 1994-03-31
Filing date: 1994-03-31
Publication date: 1995-10-04
Anticipated expiration: 2014-03-31
Also published as: GB9406542D0; GB2287948B

Abstract

A detergent composition is disclosed which comprises a hydrophobic alkoxylated nonionic surfactant, a detergency builder comprising zeolite P having a silicon to aluminium ratio not greater than 1.33 (zeolite MAP) and a lipase enzyme. Granular and liquid detergent compositions are preferred.

Description

TITLE: DETERGENT COMPOSITION The present invention relates to a detergent composition and, in particular, to improvements in the detergency performance of laundry detergent compositions comprising zeolites as a sequestering agent for water hardness.

Detergent compositions for heavy-duty fabric washing conventionally contain detergency builders which lower the concentration of calcium and magnesium water hardness ions in the wash liquor and thereby provide good detergency effect in both hard and soft water.

Conventionally, inorganic phosphates, such as sodium tripolyphosphate, have been used as builders for laundry detergents. More recently, alkali metal aluminosilicate ion-exchangers, particularly crystalline sodium aluminosilicate zeolite A, have been proposed as replacements for the inorganic phosphates.

For example, EP 21 491A (Procter & Gamble) discloses detergent compositions containing a building system which includes zeolite A, X or P (B) or a mixture thereof. EP 384070A (Unilever) discloses specific zeolite P materials having an especially low silicon to aluminium ratio not greater than 1.33 (hereinafter referred to as zeolite MAP) and describes its use as a detergency builder. To date, however, zeolite A is the preferred aluminosilicate detergency builder in commercially available products.

However, it is known that there are certain problems in the use of zeolites as detergency builders, as compared with phosphates. For example, zeolites work relatively slowly to sequester the calcium ions which reduces the detergency effect. One proposal which has been made to overcome this problem is to introduce certain co-builders to provide better and quicker hardness control. For example, GB 1429143 (Procter & BR< Gamble) and GB 1470250 (Procter & Gamble) describe a detergency building system comprising an alkali metal aluminosilicate and citrates.

It is well known that detergent compositions can include enzymes for a wide variety of fabric laundering purposes, including removal of protein-based, carbohydrate-based, or triglyceride-based stains, for example, and for the prevention of fugitive dye transfer and for fabric restoration. One class of enzyme which is conventionally included is the lipases normally accompanied by a source of calcium ions for stabilisation purposes. It has been found, however, that high levels of soluble builders, for example, phosphates and citrates, can have a negative effect on the performance of certain lipases.

The problem associated with the use of high levels of water soluble builders such as citrate or phosphates is that they prevent calcium from inhibiting the well known deactivation of lipase by the free fatty acids formed upon the hydrolysis of triglycerides by lipase.

These high levels of water soluble builders are therefore detrimental to the performance contribution of the lipase.

On the other hand, when zeolite A is used with only low levels of water soluble cobuilders or when no soluble cobuilders are used at all, calcium fatty acid complexes accumulate at the interface of the grease stain with water. This leads to a poorly dispersible outer layer of calcium fatty acid complex which acts as a crust and inhibits or prevents the subsequent removal of the stain.

A similar problem has been encountered in the use of lipases in liquid detergents, particulary heavy duty liquid detergents. It has been found that lipase has only a limited benefit as a detergent component, incorporating a detergency builder such as zeolite A, due to the formation of the calcium fatty acid crust which hardens the stain and prevents its removal by the other detergent ingredients. Consequently, the benefits of incorporating a lipase in a liquid detergent composition comprising an aluminosilicate detergency builder such as zeolite A are mainly observable under multiple cycle conditions and pretreatments, not in single wash conditions.

Surprisingly, the Applicant has found that the combination of lipase, hydrophobic nonionic surfactant and zeolite MAP improves the removal of grease stains.

Without wishing to be bound by theory, it is believed that the hydrophobic nonionic dissolves in, then emulsifies the calcium fatty acid complex formed at the grease stain/water interface whilst the zeolite MAP provides a better control of the rate of accumulation of calcium fatty acid complex at the water/stain interface than zeolite A. If Zeolite MAP is replaced by Zeolite A, the positive effect of the hydrophobic nonionic is lost. Importantly, zeolite MAP only requires low levels of water soluble cobuilders which do not deactivate the lipase.

Detergent compositions having improved overall detergency comprising certain lipases in combination with alkoxylated nonionics of low alkoxylation degree are described in EPA 0341999. This discloses a detergent composition incorporating a nonionic surfactant such as an ethoxylated alcohol having a chain length of at least 10 carbon atoms with less than five moles of ethylene oxide per mole of alcohol However, an alcohol alkoxylate is not an entirely satisfactory component in that it is inclined to leak or bleed from a solid detergent composition particularly when the product is stored at high temperatures, for example, above 40"C.

However, another benefit of the invention is that, the zeolite MAP provides better control of the leakage of the hydrophobic nonionic when a granular product in accordance with the invention is stored at elevated temperatures. In the absence of zeolite MAP the bleeding of this nonionic can lead to internal and external staining of a package containing the granular product.

Thus, according to one aspect, the invention provides a detergent composition comprising hydrophobic alkoxylated nonionic surfactant, a lipase enzyme and, as a detergency builder, zeolite MAP.

The detergent composition according to the invention may be of any physical type, for example powders, liquids and gels. However, granular and liquid compositions are preferred.

An essential component of the detergent composition according to the present invention is a hydrophobic alkoxylated nonionic surfactant. In the context of the present invention an HLB value of < 9.5 represents a hydrophobic i.e. water insoluble material.

Examples of suitable hydrophobic alkoxylated nonionic surfactants include alkoxylated adducts of fatty alcohols containing an average of less than 5 alkylene oxide groups per molecule, for example less than 4 alkylene oxide groups per molecule, e.g. 3.5 and usefully 3 alkylene oxide groups per molecule or less, and usefully also greater than 0.5, or 1, or 2, alkylene oxide groups per molecule.

The alkylene oxide residues may, for example, be ethylene oxide residues or mixtures thereof with propylene oxide residues.

Thus alkylene oxide adducts of fatty alcohols useful in the present invention can suitably be chosen from those of the general formula: R-O- (CnH2nO)yH wherein R is an alkyl or alkenyl group having at least 10 carbon atoms, most preferably from 10 to 22 carbon atoms, y is preferably from about 0.5 to about 3.5 and n is 2 or 3.

Preferred nonionic surfactants include primary C11 C15 aliphatic alcohols condensed with an average of no more than five ethylene oxide groups per mole of alcohol, having an ethylene oxide content of less than 50% by weight.

In a preferred embodiment of the invention, a granular detergent composition is provided comprising a lipase enzyme and, as the detergency builder, zeolite MAP and wherein the composition comprises a detersive surfactant which is a non-ionic surfactant of which no less than 25 wt.% is an ethoxylated alcohol (AEn) with less than 5 mols of ethylene oxide per mol of alcohol (n < 5).

A particularly preferred aliphatic alcohol ethoxylated is a primary alcohol having an average of 12 to 15 carbon atoms in the alkyl chain condensed with an average of three ethoxy groups per mole of alcohol.

Specific examples of suitable alkoxylated adducts of fatty alcohols are Synperonic A3 (ex ICI), which is a C13-C15 alcohol with about three ethylene oxide groups per molecule and Empilan KB3 (ex Marchon), which is lauric alcohol 3EO.

Another class of nonionic sufactants comprises alkyl polyglucoside compounds of general formula RO(CnH2nO)tzx wherein Z is a moiety derived from glucose; R is a saturated hydrophobic alkyl group that contains from 12 to 18 carbon atoms; t is from 0 to 10 and n is 2 or 3; x is from 1.1 to 4, the compounds including less than 10% unreacted fatty alcohol and less than 50% short chain alkyl polyglucosides. Compounds of this type and their use in detergent compositions are disclosed in EP-B 0070074, 0070077, 0075996 and 0094118.

Where the composition comprises an aliphatic alcohol ethoxylate as the hydrophobic nonionic surfactant it is present in an amount of at least 1 wt.%, preferably from 1 wt.% to 10 wt.% and more preferably 1 wit.8 to 6 wt.% of the composition.

In addition to the hydrophobic alkoxylated nonionic surfactant, which is an essential component, the detergent composition according to the invention can include one or more other surfactants selected from anionics, zwitterionics, ampholytics and cationics.

Many suitable detergent-active compounds are available and fully described in the literature (for example "Surface Active Agents and Detergents" Volumes I and II by Schwartz, Perry and Berch).

Examples of suitable anionic surfactants include alkyl benzene sulphonates, particularly linear alkyl benzene sulphonates having an alkyl chain length of C8- C15; primary and secondary alkyl sulphates, particularly C12 - C15 primary alkyl sulphates; alkyl ether sulphates; olefin sulphonates; alkyl xylene sulphonates; dialkylsulphosuccinates; and fatty acid ester sulphonates. Sodium salts are generally preferred.

The detergent composition of the invention generally contains a detergent surfactant in a range of from 5 to 60 wt.%, preferably 5 to 40 wt.% and most preferably from 10 to 25 wt.% of the composition.

According to the present invention the detergency builder system is based on zeolite MAP, optionally in conjunction with one or more supplementary builders. The amount of zeolite MAP employed may range, for example, from 5 to 60 wit.%, more preferably from 15 to 40 wt.%.

Zeolite MAP is described in EP 384070A (Unilever).

It is defined as an alkali metal alumino-silicate of the zeolite P type having a silicon to aluminium ratio not greater than 1.33, preferably within the range from 0.9 to 1.33 and more preferably within the range of from 0.9 to 1.2.

Of particular interest is zeolite MAP having a silicon to aluminium ratio not greater than 1.15 and, more particularly, not greater than 1.07.

Zeolite P having a Si:Al ratio of 1.33 or less may be prepared by the following steps: (i) mixing together a sodium aluminate having a mole ratio Na20:A1203 within the range of from 1.4 to 2.0 and a sodium silicate having a mole ratio Si02:Na20 within the range of from 0.8 to 3.4 with vigorous stirring at a temperature within the range of from 25"C to boiling point usually 95"C, to give a gel having the following composition; A1203: (1.75-3.5) Si02 : (2.3-7.5) Na20 :P (80-450)H20; (ii) ageing the gel composition for 0.5 to 10 hours, preferably 2 to 5 hours, at a temperature within the range of from 70"C to boiling point, usually to 95"C, with sufficient stirring to maintain any solids present in suspension; (iii) separating the crystalline sodium aluminosilicate thus formed, washing to a pH within the range of from 10 to 12.5, and drying, preferably at a temperature not exceeding 1500C, to a moisture content of not less than 5 wit.%.

Preferred drying methods are spray-drying and flash drying. It appears that oven drying at too high a temperature may adversely affect the calcium binding capacity of the product under certain circumstances.

Commercial sodium metasilicate pentahydrate dissolved in water and commercial sodium silicate solution (waterglass) are both suitable silica sources for the production of zeolite P in accordance with the invention. The reactants may be added together in any order either rapidly or slowly. Rapid addition at ambient temperature, and slow addition at elevated temperature (90-95 C) both give the desired product.

Vigorous stirring of the gel during the addition of the reactants, and at least moderate stirring during the subsequent ageing step, however, appear to be essential for the formation of pure zeolite P. In the absence of stirring, various mixtures of crystalline and amorphous materials may be obtained.

Zeolite MAP generally has a calcium binding capacity of at least 150 mg CaO per g of anhydrous aluminosilcate, as measured by the standard method described in GB 1473201 (Henkel). The calcium binding capacity is normally 160 mg CaO/g and may be as high 170 mg CaO/g.

Although zeolite MAP like other zeolites contains water of hydration, for the purposes of the present invention amounts and percentages of zeolite are expressed in terms of the notional anhydrous material.

The amount of water present in hydrated zeolite MAP at ambient temperature and humidity is generally about 20 wt.%.

Preferred zeolite MAP for use in the present invention is finely divided and has a d50 (as defined hereinafter) within the range of from 0.1 to 5.0 micrometres. The quantity "d50,, indicates that 50 wt.t of the particles have a diameter smaller than that figure.

A preferred zeolite MAP for use according to the present invention has a d50 of from 1.0 to 5.0 micrometres, for example 2.25 to 5 micrometres, more particularly 2.75 to 5 micrometres.

According to one embodiment of the invention the zeolite MAP detergent builder is in powder form.

For convenience in handling, however, the material may be granulated by conventional techniques such as spray drying or by a non-tower method to form larger particles.

The detergent composition according to present invention essentially comprises a lipase enzyme.

Suitable lipase enzymes for detergent usage include those procured by microorganisms of the Pseudomonas group, such as Pseudomonas stutzeri ATCC 19.154, as disclosed in British Patent 1,372,034. See also lipases in Japanese Patent Application 53-20487, laid open to public inspection on February 24, 1978.

This lipase is available from Amano Pharmaceutical Co.

Ltd., Nagoya, Japan, under the trade name Lipase P "Amano," hereinafter referred to as "Amano-P". Other commercial lipases include Amano-CES, lipases ex Chromobacter viscosum, e.g. Chromobacter viscosum var.

lipolyticum NRRLB 3673, commercially available from Toyo Jozo Co., Tagata, Japan; and further Chromobacter viscosum lipases from U.S. Biochemical Corp., U.S.A. and Disoynth Co. The Netherlands, and lipases ex Pseudomonas gladioli. The LIPOLASE enzyme derived from Humicola lanuginosa and commercially available from Novo (see also EPO 341,947) is a preferred lipase for use herein.

The lipase is normally incorporated in the detergent composition in an amount sufficient to provide up to about 4000 Lipase units, preferably 10 to 3000 Lipase units per gram of the composition. Typically, the composition will generally comprise from 0.001% to about 5%, preferably 0.01 to 1% by weight of a commercial enzyme preparation.

In the granular detergent compositions according to the invention, the detergency builder can be zeolite MAP alone or a combination of zeolite MAP with an organic or inorganic cobuilder.

Suitable organic cobuilders can be monomeric or polymeric carboxylates such as citrates or polymers of acrylic, methacrylic and/or maleic acids in neutralised form. Suitable inorganic cobuilders include carbonates and amorphous and crystalline lamellar sodium silicates.

Suitable lamellar silicates have the composition: NaMSix02x+l , yH20 where M is sodium or hydrogen, preferably sodium; x is a number from 1.9 to 4; and y is a number from 0 to 20.

Such materials are described in US Patents No. 4664839; No. 4728443 and No. 4820439 (Hoechst AG). Especially preferred are compounds in which x = 2 and y = O. The synthetic material is commercially available from Hoechst synthetic material is commercially available from Hoechst AG as S-Na2 Si205 (SKS6) and is described in US Patent No. 4664830.

The total amount of detergency builder in the granular composition ranges from 10 to 80 wt.%, more preferably from 15 to 60 wtG and most preferably from 10 to 45 wt.%.

Detergent compositions according to the invention may also suitably contain a bleach system. This preferably comprises one or more peroxy bleach compounds, for example, inorganic persalts or organic peroxyacids, which may be employed in conjunction with bleach precursors to improve bleaching action at low temperatures.

The bleach system preferably comprises a peroxy bleach compound, preferably an inorganic persalt, optionally in conjunction with a precursor. Suitable persalts include sodium perborate monohydrolate and tetrahydrolate and sodium percarbonate, with sodium percarbonate being most preferred.

Preferred bleach precursors are peracetic acid precursors, such as tetraacetylethylene diamine (TAED) peroxybenzoic acid precursors.

Other materials which may be present in the detergent compositions of the invention include, for example, fluorescers, antiredeposition agents, inorganic salts such as sodium sulphate, other enzymes, lather control agents, fabric softening agents, pigments, coloured speckles and perfumes.

The detergent compositions of the invention may be prepared by any suitable method. The particulate detergent compositions are suitably prepared by any tower (spray-drying) or non-tower process.

In processes based around a spray-drying tower, a base powder is first prepared by spray-drying a slurry and then other components unsuitable for processing via the slurry can be sprayed on or admixed (postdosed). The lipase enzyme will generally be post-dosed.

The zeolite MAP is suitable for inclusion in the slurry, although it may be advantageous for processing reasons for part of the zeolite MAP to be incorporated post-tower. The lamellar silicate, where this is employed, is also incorporated via a non-tower process and is preferably postdosed.

Alternatively, particulate detergent compositions in accordance with the invention may be prepared by wholly non-tower processes such as granulation.

The granular detergent compositions of the invention may be prepared to any suitable bulk density. The compositions preferably have a bulk density of at least 400 g/l preferably at least 550 g/l, most preferably at least 700 g/l and, with particular preference at least 800 g/l.

The benefits of the present invention are particularly evident in powders of high bulk density, for example, of 700 g/l or above. Such powders may be prepared either by post-tower densification of spraydried powder, or by wholly non-tower methods such as dry mixing and granulation; in both cases a high-speed mixer/granulator may advantageously be used. Processes using high-speed mixer/granulators are disclosed, for example, in EP340 013A, EP 367 339A, EP 390 251A and EP 420 317A (Unilever).

According to a further aspect of the invention there is provided a liquid detergent, composition, preferably a heavy duty liquid detergent composition, comprising a hydrophobic alkoxylated nonionic surfactant, zeolite MAP, optionally in combination with other detergency builders, and a lipase enzyme.

According to this embodiment the liquid detergent composition may be of any convenient physical form which may be aqueous or anhydrous. The term "liquid" used herein includes pasty viscous formulations such as gels.

The liquid detergent system comprises, as the detergency builder zeolite MAP optionally in combination with other detergency builders such as fatty acids, citric acid or zeolite A.

A preferred co-builder is a lamellar sodium silicate such as SKS-6 which is particularly useful in pasty viscous formulations such as gels or in non-aqueous liquid detergents such as those described in W092/16608 (Henkel).

The liquid detergent composition generally has a pH of from 6.5 to 10.5.

The total amount of detergency builder in the liquid composition is preferably from 5 to 70% of the total liquid composition.

According to a further aspect, the invention provides use of a composition comprising zeolite MAP and a lipase enzyme as an additive for a detergent composition.

Illustrative compositions according to the present invention are presented in the following Examples.

The following abbreviations have been used in the Tables: AS : Sodium alkyl sulphate E07 : C14-C15 primary aliphatic ethoxylated alcohol having an average of 7 ethoxy groups per mole of alcohol.

E03 : C12-C15 primary aliphatic ethoxylated alcohol having an average of 3 ethoxy groups per mole of alcohol.

LAS : linear C8 1l alkyl benzene sulphonate.

Soap : tallow soap.

TAED : Tetraacetyl ethylene diamine.

DETPMP : Diethylene triamine penta (methylene phosphonic acid), marketed by Monsanto under the Trade Name Dequest 2060.

MA/AA : Copolymer of 1:4 maleic/acrylic acid (Mw 80,000).

Citrate : Trisodium citrate dihydrate.

Enzyme granules : mixed proteolytic and amylolytic enzyme granule sold by Novo Industries A/S.

Antifoam granules : Mixture of silanated silica: silicone in ratio of 1:1.5(M Wt 100,000).

Examples Particulate components and compositions were prepared as follows: Component Example No.

1 2 3 4 5 AS(C12-15) 9 AS(C12-14) - 9 11 11 9 E07 (C14-C15) 3 7 0 - 6 E03 (C12-C15) 4 2 7 5 4 Soap - - 2 - Alkyl polyglycoside - - - 4 (C12 14. D614).

Zeolite MAP (anhydrous). 20 25 30 30 24 Dodecanediol - - - - 3 Sodium carbonate 13 6 18 18 15 Sodium bicarbonate - - 5 5 5 Amorphous sodium silicate. 3 5 3 3 3 Layered crystalline sodium silicate (#-Na2Si2O5). 0 0 0 0 0 Citrate O 0 0 9 0 Sodium percarbonate. 18 24 - - TAED granules 10 4 0 - DETPMP 0.5 0.3 0.4 0.4 0.4 MA/AA 3 4 5 5 5 Antifoam granules. 2 2 2 2 2 Enzyme granules. 2 2 2 2 2 Lipase (100 ALU/g). 0.3 0.2 0.1 0.1 0.1 Moisture & Balance Balance Balance Balance Balance miscellaneous. to 100% to 100% to 100% to 1002 to 1002 EXAMPLE 6: A liquid detergent composition was prepared as follows: COMPONENT PARTS.

Surfactant LAS (present as potassium salt). 19.38 E07 3.7 E03 5.0 Builders Citric acid (present as potassium salt) 13.06 Fatty acid cococut 4.3 Zeolite MAP 16.4 Chelant DETPMP 0.2 Enzvmes Protease (Alcalase) 1.8 Lipase 0.12 Amylase (Termamyl) 0.13 Water 30.81 Sodium metaborate 2.75 Fluorescer (Brightener 49) 0.08 Suds suppressor (silica silicone mixture) 0.12 Glycerine 1.15 Structurant Polymer Polyacrylic acid salt of MWt 6000 1.0 TOTAL 100 DOSAGE: lOOg/l

Claims

CLAIMS 1. A detergent composition comprising (a) a hydrophobic alkoxylated nonionic surfactant (b) one or more detergency builder comprising zeolite P having a silicon to aluminium ratio not greater than 1.33 (zeolite MAP); and (c) a lipase enzyme.
2. A detergent composition according to claim 1, wherein component (b) comprises an inorganic or organic cobuilder in a weight ratio of zeolite MAP to cobuilders of from 100:0 to 70:30.
3. A detergent composition according to either claim 1 or 2, wherein component (b) comprises citrate as a cobuilder.
4. A detergent composition according to any one of claims 1 to 3, wherein component (b) comprises a layered crystalline sodium silicate as a cobuilder.
5. A detergent composition according to any one of claims 1 to 4, wherein component (a) includes a cosurfactant selected from anionic, water-soluble nonionic , zwitterionic, amphoteric and cationic surfactants and mixtures thereof.
6. A detergent composition according to claim 5, wherein component (a) comprises a mixture of anionic and nonionic surfactants.
7. A detergent composition according to any of claims 1 to 6, which is granular.
8. A detergent composition according to claim 7, which comprises: (a) from 5 to 60 wt.% of a mixture of hydrophobic alkoxylated nonionic, water soluble nonionic and anionic superfactants.

(b) from 10 to 80 wt.% of one or more detergency builders comprising zeolite MAP; and (c) a lipase enzyme in an amount to provide a lipase activity of up 4000 Lipase units per gram of the composition.
9. A detergent composition according to claim 8 which comprises from 5 to 40 wt.% of component (a); from 20% to 60 wt.% of component (b); and component (c) in an amount to provide from 10 to 3000 Lipase units per gram of the composition.
10. A detergent composition according to any of claims 1 to 9, which comprises an aliphatic alcohol ethoxylate in an amount of from 1 wt% to 10 wt% of the composition.
11. A detergent composition according to claim 10, which comprises the aliphatic alcohol ethoxylate in an amount of from 1 wt% to 6 wt% of the composition.
12. A detergent composition according to any of claims 1 to 11 wherein the component (a) comprises a non-ionic surfactant of which no less than 25% wt.% is an ethoxylated alcohol (AEn) with less than 5 mols of ethoxy per mol of alcohol (n < 5).
13. A detergent composition according to any one of claims 1 to 3, which is a liquid formulation.
14. A liquid detergent composition according to claim 11 which is non-aqueous.
15. A liquid detergent composition according to either one of claims 13 and 14 which comprises: (a) from 5 to 60 wt.% of one or more detergent active compounds; (b) from 5 to 40 wt.% of one or more detergency builders comprising zeolite MAP; (c) a lipase enzyme in an amount to provide up to 5000 Lipase units per gram of the composition
16. A detergent composition according to any of claims 1 to 15 wherein the zeolite MAP has a particle size d50 of from 1 to 5 micrometres.
17. Use of a composition comprising zeolite MAP and a lipase enzyme as an additive for a detergent composition comprising a hydrophobic nonionic surfactant.