Enzymatic liquid detergent compositions

Abstract

 The invention pertains to enzymatic liquid detergent compositions in which the enzymes comprise a mixture of lipolytic enzymes and proteolytic enzymes. The storage stability of lipolytic enzymes in these proteolytic enzymes containing liquid detergent compositions is enhanced therein by the inclusion of a lower aliphatic alcohol such as ethanol and a salt of a lower carboxylic acid such as sodium formate and by providing for a detergent-surfactant system therein which predominantly consists of a nonionic detergent.
The lipases are fungal lipases ex Humicola lanuginosa or Thermomyces lanuginosus. The proteolytic enzymes are preferably of the subtilisin type.

Description

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

[0001] The present invention relates to enzymatic liquid detergent compositions comprising lipolytic enzymes ex Humicola lanuginosa or Thermomyces lanuginosus and proteolytic enzymes

DESCRIPTION OF THE RELATED ART

[0002] Enzymatic liquid detergent compositions are well-known in the art. Most of the prior proposals are however concerned with enzymatic liquid detergent compositions which contain a proteolytic enzyme ingredient, or a mixture thereof with amylolytic enzymes.

[0003] One of the problems, inherent to the use of enzymes in liquid detergent compositions is their stability in such liquid detergent compositions. The art is crowded with a variety of proposals to improve the stability of enzymes, particularly proteolytic and/or amylolytic enzymes in liquid detergent compositions. Thus, for example, in European Patent Specifications 28,865 and 28,866 it has been proposed to stabilize enzymes in liquid detergent compositions by the inclusion therein of a certain amount of enzyme-accessible calcium and a certain amount of a short chain carboxylic acid or a salt thereof, such as sodium formate. The enzymes are preferably proteolytic enzymes.

[0004] The art is far less concerned with lipolytic enzymes in liquid detergent compositions. Although lipases have recently been proposed for inclusion in detergent compositions, see e.g. U.S. Patent 4,707,291 (Thom et al.), they have been mainly considered for inclusion in particulate detergent compositions. In European Patent Application 0258,068 a particular lipase ex Humicola lanuginosa is proposed as a detergent additive, also for inclusion in liquid detergent compositions. According to this reference, 1, 2 - propanediol and calcium salts improve the stability of this lipase in liquid systems. Sorbitol has only a slight stabilizing effect.

[0005] The present invention is particularly concerned with the above lipases ex Humicola lanuginosa or Thermomyces lanuginosus, hereinafter collectively referred to as ex Humicola lanuginosa.

[0006] Since these lipases, like all enzymes, are proteins, they are susceptible to proteolytic attack by proteolytic enzymes, which further reduces the stability of these lipases in compositions also comprising proteolytic enzymes.

[0007] It is therefore an object of the present invention to improve the storage stability of these lipolytic enzymes ex Humicola lanuginosa or Thermomyces lanuginosus in liquid detergent compositions which also comprise proteolytic enzymes.

SUMMARY OF THE INVENTION

[0008] It has now been found, that the inclusion of a lower aliphatic alcohol and a salt of a lower carboxylic acid in a proteolytic enzyme containing liquid detergent composition which comprises a detergent-active system which consists predominantly of a nonionic detergent significantly improves the storage stability of lipolytic enzymes ex Humicola lanuginosa in such liquid detergent compositions in the presence of proteolytic enzymes.

[0009] Consequently, in its broadest aspect the present invention relates to a proteolytic enzymes containing liquid detergent composition comprising a detergent-active system which consists predominantly of a nonionic detergent, and furthermore comprising a lipolytic enzyme ex Humicola lanuginosa, a lower aliphatic alcohol and a salt of a lower carboxylic acid as the essential components.

DETAILED DESCRIPTION OF THE INVENTION

[0010] The first essential component of the liquid detergent composition is the nonionic detergent. Nonionic detergents are well-known in the art. They are normally reaction products of compounds having a hydrophobic group and a reactive hydrogen atom, for example aliphatic alcohols, acids, amides or alkylphenols with alkylene oxides, especially ethylene oxide either alone or with propylene oxide. Typical examples of suitable nonionic detergents are alkyl (C₆-C₂₂) phenol-ethylene oxide condensation products, with generally 5-25 moles of ethylene oxide per mole of alkylphenol, the condensation products of aliphatic C₈-C₁₈ primary or secondary, linear or branched chain alcohols with generally 5-40 moles of ethylene oxide, and products made by condensation of ethylene oxide and propylene oxide with ethylenediamine. Other nonionic detergents include the block copolymers of ethylene oxide and propylene oxide, alkylpolyglycosides, tertiary amine-oxides and dialkylsulphoxides. The condensation products of the alcohols with ethylene oxide are the preferred nonionic detergents.

[0011] In the present invention, one of the above nonionic detergents may be used as well as mixtures thereof. The nonionic detergent or detergents may form the sole detergent-active system in the liquid detergent composition, or they may be in admixture with other detergent-active compounds such as anionic, cationic, zwitterionic or ampholytic detergent-active compounds, as long as the nonionic detergent constitutes the major part of the detergent-active system. The nonionic detergent should form at least 50%, usually at least 60%, preferably at least 70% by weight of the detergent-active system. The total amount of detergent-active compound in the composition ranges from 10-90, usually from 15-70% by weight.

[0012] The second essential ingredient of the present invention is the lipolytic enzyme. This lipolytic enzyme is a fungal lipase producible by Humicola lanuginosa and Thermomyces lanuginosus.

[0013] Examples of fungal lipases as defined above are the lipases ex Humicola lanuginosa, as described in the aforesaid European Patent Application 0258,068 (NOVO), as well as the lipase obtained by cloning the gene from Humicola lanuginosa and expressing this gene in Aspergillus oryzae, commercially available from NOVO Industri A/S under the trade name "Lipolase"®. This Lipolase is a preferred lipase for use in the present invention.

[0014] The lipases of the present invention are included in the liquid detergent composition in such an amount that the final composition has a lipolytic enzyme activity of from 100 to 0.005 LU/mg, preferably 25 to 0.05 LU/mg of the composition.

[0015] A Lipase Unit (LU) is that amount of lipase which produces 1 µmol of titratable fatty acid per minute in a pH stat. under the following conditions: temperature 30^oC; pH = 9.0; substrate is an emulsion of 3.3 wt.% of olive oil and 3.3% gum arabic, in the presence of 13 mmol/ Ca²⁺ and 20 mmol/l NaCl in 5 mmol/l Tris-buffer.

[0016] Naturally, mixtures of the above lipases can be used. The lipases can be used in their non-purified form or in a purified form, e.g. purified with the aid of well-known adsorption methods, such as phenyl sepharose adsorption techniques.

[0017] The third essential ingredient of the present invention is the lower aliphatic alcohol. This alcolhol can be methanol, ethanol, propanol and isopropanol or mixtures thereof. A preferred alcohol is ethanol.

[0018] The amount of lower aliphatic alcohol to be used in the present invention depends to some extent on the composition of the liquid detergent, but in general it varies from 1 - 10% by weight, preferably from 2 - 8% by weight of the final composition.

[0019] The fourth essential ingredient of the present invention is the salt of the lower aliphatic carboxylic acid. This acid contains from 1 - 3 carbon lower aliphatic carboxylic acid. This acid contains from 1 - 3 carbon atoms, such as formic acid, acetic acid and propionic acid. It may be included in the liquid detergent composition as an acid, the salt being formed in situ therein by methathesis, or the salt of the acid may be included in the liquid detergent composition. Suitable salts are the water-soluble alkalimetal and mono-, di- and triethanolamine salts. Particularly preferred is sodium formate. In general, the amount of the salt of the lower aliphatic carboxylic acid used in the present invention ranges from 0.1 - 5% by weight, preferably from 0.5 - 3.5% by weight of the final composition. Naturally, mixtures of salts of these lower aliphatic carboxylic acids can be used.

[0020] The fifth essential ingredient of the present invention is the proteolytic enzyme. This enzyme can be of vegetable, animal or microorganism origin. Preferably it is of the latter origin, which includes yeasts, fungi, molds and bacteria. Particularly preferred are bacterial subtilisin type proteases, obtained from e.g. particular strains of B. subtilis and B. licheniformis. Examples of suitable commercially available proteases are Alcalase®, Savinase®, Esperase®, all of NOVO Industri A/S; Maxatase® and Maxacal® of Gist-Brocades; Kazusase® of Showa Denko; BPN and BPN′ proteases and so on. The amount of proteolytic enzyme, included in the composition, ranges from 0.1- 50 GU/mg, based on the final composition. Naturally, mixtures of different proteolytic enzymes may be used.

[0021] A GU is a glycine unit, which is the amount of proteolytic enzyme which under standard incubation conditions produces an amount of terminal NH2-groups equivalent to 1 microgramme/ml of glycine.

[0022] The liquid detergent compositions of the present invention can furthermore contain one or more other, optional ingredients. Such optional ingredients are e.g. perfumes, including deoperfumes, colouring materials, opacifiers, soil-suspending agents, soil-release agents, solvents such as propylene glycol, hydrotropes such as sodium cumene-, toluene- and xylenesulphonate as well as urea, alkaline materials such as mono-, di- or triethanol-amine, clays, fabric-softening agents and so on. The liquid detergent composition may be unbuilt or built, and may be aqueous or non-aqueous. If a built liquid detergent composition is required, the composition may contain from 1 - 60%, preferably 5 - 30% by weight of one or more organic and/or inorganic builder. Typical examples of such builders are the alkalimetal ortho-, pyro- and tri- polyphosphates, alkalimetal carbonates, either alone or in admixture with calcite, alkalimetal citrates, alkalimetal nitrilotriacetates, carboxymethyloxy succinates, zeolites, polyacetal carboxylates and so on.

[0023] It may also be advantageous to include a certain amount of a calcium salt to further improve the enzyme stability. A typical example of a suitable calcium salt is calcium chloride; the calcium salt should be added in such an amount, that from 0.1 - 2 millimoles of enzyme-accessible free calcium (i.e. calcium, not sequestrated by any of the ingredients of the composition, e.g. a builder) is available per kilogramme of the final composition.

[0024] The compositions may furthermore comprise lather boosters, foam depressors, anti-corrosion agents, chelating agents, anti-soil redeposition agents, bleaching agents, other stabilizing agents for the enzymes, activators for the bleaching agents and so on. They may also comprise enzymes other than the proteases and lipases, such as amylases, oxidases and cellulases. In general, the compositions may comprise such other enzymes in an amount of 0.01-10% by weight.

[0025] When the liquid detergent composition is an aqueous composition, the balance of the formulation consists of an aqueous medium. When it is in the form of a non-aqueous composition, the above ingredients together with the essential ingredients make up for the whole formulation.

[0026] The invention will further be illustrated by way of Example.

Example I

[0027] The stability of Lipolase® in various aqueous systems was assessed at 37^oC over 27 days of storage. The aqueous systems all contained also a proteolytic enzyme Savinase 16.0 L ex NOVO, in an amount equivalent to 30 GU/ml of the system. The aqueous systems contained either 4.9% ethanol, or 2.7% sodium formate, or 16.5% of a nonionic detergent which was a C₁₂ - C₁₅ linear primary alcohol, condensed with 9 moles of ethylene oxide, or a mixture of 4.9% ethanol, 2.7% sodium formate and 16.5% of the nonionic detergent.

[0028] Figure I shows the results of these stability tests. It can be clearly seen, that the ternary mixture ethanol/sodium formate/nonionic detergent produced an unexpectedly improved lipolytic enzyme storage stability, in comparison with the single components.

Example II

[0029] With the same systems as above, as well as various combinations of the ingredients, the half-life time of the Lipolase was assessed. The following table gives the results.

System	Initial pH	Half-life time in days at 37°C
water	7.1	1.5
nonionic detergent	5.4	1
ethanol	5.8	less than 1 day
sodium formate	7.9	7 days
ethanol plus nonionic detergent	5.8	less than 1 day
ethanol plus sodium formate	7.9	11
nonionic detergent plus sodium formate	6.4	8
nonionic detergent plus sodium formate plus ethanol	6.5	17

Example III

[0030] The following liquid detergent composition was tested as to the stability of Lipolase therein.

	% by weight
C₁₂-C₁₃ primary linear alcohol, condensed with 9 moles of ethylene oxide	22.6
Sodium coconut alcohol diethyleneglycolethersulphate	5.3
Sodium coconut alcoholsulphate	3.5
Sodium formate	1.9
Ethanol	6.2
Water	q.s.

[0031] The composition also contained Lipolase and Savinase in amounts, yielding an activity of 15LU/ml resp. 30 GU/ml at a dosage of the composition of 2 g/l. to a wash liquor.

[0032] The half-life time at 37^oC of the Lipolase was 7 days. Increasing the amount of sodium formate to 2.7% yielded a half-life time of the Lipolase of more than 1.5 months.

Example IV

[0033] The same amounts of Lipolase and Savinase of Example 3 were used in the following liquid detergent composition

	% by weight
C12-C15 linear primary alcohol, condensed with 10 moles of ethylene oxide	16.5
Sodium dodecylbenzenesulphonate	3.5
Polyethyleneglycol ester	0.6
Sodium Formate	2.7
Ethanol	4.9
Water	q.s.

[0034] The half-life at 37^oC time of the Lipolase was more than 1.5 months.

Claims

1. An enzymatic liquid detergent composition comprising

a) from 10-90% of a detergent-active system which consists for at least 50% of one or more nonionic detergent-active compounds.

b) one or more lipases selected from the group consisting of fungal lipases obtainable from Humicola lanuginosa or Thermomyces lanuginosus , in an amount, such that the final composition has a lipolytic activity of 0.005-100 LU/mg,

c) from 1-10% by weight of a lower aliphatic alcohol having 1-4 carbon atoms,

d) from 0.1-5% by weight of a water-soluble salt of a lower aliphatic carboxylic acid having 1-3 carbon atoms.
and

e) proteolytic enzymes in an amount such that the final composition has a proteolytic activity of 0.1-50 GU/mg.

2. The composition of claim 1, comprising 15-70% by weight of a), 0.05-25 LU/mg of b), 2-8% by weight of c) and 0.5-3.5% by weight of d).

3. The composition of claim 1, wherein the lower aliphatic alcohol is ethanol, the water-soluble salt of the lower aliphatic carboxylic acid is sodium formate, and the nonionic detergent-active compound is an ethoxylated C8-C18 primary, linear alcohol.

4. The composition of claim 1, wherein the lipase is a lipase, obtained by cloning the gene from Humicola lanuginosa and expressing this gene in Aspergillus oryzae.

5. The composition of claim 1, wherein the proteolytic enzyme is a bacterial subtilisin.

6. The composition of claim 1, further comprising a calcium salt in such an amount that the composition contains from 0.1-2 millimoles of enzyme-accessible free calcium per kilogramme of the final product.

Drawing