JPS5811196B2 - Stable aqueous enzyme composition - Google Patents

Description

TECHNICAL FIELD Field of the Invention The present invention relates to stable aqueous enzyme compositions that preferably include detergent compounds.

Description of the Technology Preparing aqueous liquid detergent compositions containing enzymes is extremely difficult because the enzyme activity rapidly decreases in the aqueous medium during storage.

U.S. Pat. No. 4,1 for liquid cleaning compositions containing enzymes
No. 11,855 discloses one solution for stabilizing enzymes in aqueous media.

The patent utilizes a combination of polyacids, free calcium ions, and lower aliphatic alcohols for enzyme stabilization.

DISCLOSURE OF THE INVENTION The stable aqueous enzyme compositions of the present invention contain (a) from 0% to about 75% detersive surfactant, (b) from about 0% to about 1% detersive surfactant, (bJ enzyme, preferably from about 0% to about 1% protease), (C ) low molecular weight
or secondary alcohols from 0 to about 20%, preferably from about 5% to about 15%, (for dJ low pH products from about 0.1% to
about 10%, preferably about 0.3% to about 3% formate, (e) calcium ions per e for high pH products and about 0 for low pH products. .1 to about 10 mmol, preferably about 0.5 to about 1.5 mmol, for high pH products, about 4 to about 8 mmol; The pH is about 6.5 to about 10 for enzyme stability, preferably about 7 to about 8.5, and about 8.5 to about 10 for detergency.

DETAILED DESCRIPTION OF THE INVENTION Detergent surfactants Detergent surfactants include nonionic, anionic, cationic,
It can be selected from zwitterionic, zwitterionic and semipolar nonionic surfactants and mixtures thereof.

Preferably, the surfactant comprises significant amounts of nonionic surfactants along with anionic surfactants, semipolar nonionic surfactants or cationic surfactants or mixtures thereof.

The surfactant is preferably about 10% to about 75%, more preferably about 20% to about 50%.

Nonionic surfactantsNonionic surfactants are typically prepared by combining ethylene oxide with a hydrocarbon having a reactive hydrogen atom, such as a hydrocarbon containing a hydroxyl, carboxyl, amino or amide group, and the presence of an acidic or basic catalyst. Manufactured by condensation.

The nonionic surfactant has the formula: RA(CH2CH20).

H (in the formula, R represents a hydrophobic group, A represents a group having a reactive hydrogen atom, and n represents the average number of ethylene oxide groups).

R typically contains from about 8 to about 22 carbon atoms, but may also be formed by the condensation of propylene oxide and a low molecular weight compound.

n is usually about 2 to about 24.

The hydrophobic group of the nonionic compound has about 8 to about 24 carbon atoms.
, preferably about 12 to about 20 primary or secondary straight chain or slightly branched aliphatic alcohols.

Suitable nonionic surfactants are more fully disclosed in the aforementioned US Pat. No. 4,111,855, which is incorporated herein by reference.

Anionic surfactant synthesis Anionic surfactants can be synthesized by the general formula R1S03M, where R1 is a straight or branched chain alkyl group having about 8 to about 24 carbon atoms, and the alkyl group has about 9 to about 15 carbon atoms. represents a hydrocarbon group selected from the group consisting of alkylphenyl groups, including M is a salt-forming cation, typically sodium, potassium, ammonium, monoalkanolammonium, dialkanolammonium, trialkanolammonium and magnesium selected from the group consisting of cations and mixtures thereof.

Preferred synthetic anionic surfactants have an alkyl group of about 9
A water-soluble salt of an alkylbenzene sulfonic acid containing ~15 carbon atoms.

Another preferred synthetic anionic surfactant has an alkyl group containing about 8 to about 24 carbon atoms, preferably about 10 to about 18 carbon atoms, and about 1 to about 20 carbon atoms, preferably about 1 to about 12 carbon atoms. It is a water-soluble salt of alkyl polyethoxylate ether sulfate in which ethoxy groups are present.

Other suitable anionic surfactants include U.S. Pat.
No. 0,565 (incorporated herein by reference)
Other suitable anionic surfactants include soaps and fatty acids having from about 8 to about 24 carbon atoms, which tend to bind calcium ions and are therefore preferred. It is limited to about 1 to about 15%, most preferably about zo% to about 20%.

Cationic Surfactants Suitable cationic surfactants have the general formula: Rm R3XYL Z where each R2 is optionally substituted with up to 3 phenyl or hydroxyl groups, optionally selected from the group consisting of an organic group containing a straight or branched alkyl or alkenyl group interrupted by up to 4 groups, each R2 being about 8 to 2
2 carbon atoms and may further contain up to about 12 ethylene oxide groups, m represents a number from 1 to 3, and R
3 each represents an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group, or a benzyl group, one or less of R3 in the molecule is a benzyl group, X is a number from 0 to 11, and the remaining optional carbon atom positions are filled with hydrogen and Y is selected from the group consisting of (9) mixtures thereof).

A more complete disclosure is found in U.S. Pat. No. 4,228,044, which relates to laundry detergent compositions with enhanced particulate soil removal and anti-redeposition performance, which is incorporated herein by reference. include.

Care should be taken when including cationic substances, including surfactants, as some cationic substances have been found to reduce the effectiveness of enzymes.

Zwitterionic Surfactants Zwitterionic surfactants are aliphatic quaternary ammonium,
including derivatives of phosphonium and sulfonium compounds;
The aliphatic radicals may be straight-chain or branched, one of the aliphatic substituents containing about 8 to 24 carbon atoms and one containing an anionic water-solubilizing group.

Particularly preferred zwitterionic materials are U.S. Pat.
No. 262 and No. 3,929,678, both of which are incorporated herein by reference.

Amphoteric surfactants Amphoteric surfactants include derivatives of aliphatic heterocyclic secondary and tertiary amines, where the aliphatic groups may be straight-chain or branched and where the aliphatic substituents one contains about 8 to about 24 carbon atoms, and at least one aliphatic substituent includes an anionic water-solubilizing group.

Semi-polar nonionic surfactants Semi-polar nonionic surfactants contain from about 8 to about 28 carbon atoms.
one alkyl group or hydroxyalkyl group and two groups selected from alkyl groups and hydroxyalkyl groups having from 1 to about 3 carbon atoms optionally bonded to a ring structure. Amine oxide; a water-soluble compound containing one alkyl or hydroxyalkyl group having from about 8 to about 28 carbon atoms and two groups selected from the group consisting of alkyl and hydroxyalkyl groups having from about 1 to about 3 carbon atoms; and about 8 to about 2 carbon atoms;
A water-soluble sulfoxide containing one 8 alkyl group or a hydroxyalkyl group and a group selected from the group consisting of an alkyl group of 1 to 3 carbon atoms and a hydroxyalkyl group.

For a more complete disclosure of compounds suitable for inclusion in cleaning compositions, see U.S. Pat.
No. 4,035,257, No. 4,033,718, No. 4,019,999, No. 4,019,998
No. 3,985,669, all of which are hereby incorporated by reference.

Enzyme In the present invention, the enzyme component is blended in an amount of about 0.025 to about 1%, preferably about 0.05% to about 0.2%.

Preferred protease components are at least about 4 per 11
The composition should provide a proteolytic activity of about 15 to about 70 Anson units per 11, most preferably about 20 to about 40 Anson units per 11.

A proteolytic activity of about 3 to about 5 ansons per gram of product is desirable.

Other enzymes, including starch-degrading enzymes, may also be included.

The enzyme component has a molecular weight of about 8.5 to about 10, preferably about 9 to about 9.
It is preferably characterized by having an isoelectric point of 5.

Examples of suitable proteolytic enzymes include the many types that are known to be suitable for use in cleaning compositions, and have in fact been used in cleaning compositions.

Enzyme sources include commercially available enzyme preparations, such as "Alcalase", marketed by Novo Industries, and Gist-Bloc, Delft, The Netherlands, containing about 10% to about 20% enzyme. Brocades
Maxatase (Maxat
Including ase etc.

Other preferred enzyme compositions include trademark 5P-72 (“Esp
Erase )”] and Gist in Delft, Netherlands.
Including those marketed under the trademark "AZ-Protease" manufactured and sold by Brocades.

A more complete disclosure of suitable enzymes is found in U.S. Patent No. 4.101
, 457, which is incorporated herein by reference.

Alcohols Low molecular weight primary or secondary alcohols are, for example, methanol, ethanol, propatool and impropatol.

Although monohydric alcohols are preferred for solubilizing the surfactant, polyols containing from 2 to about 6 carbon atoms and from 2 to about 6 hydroxyl groups may be useful, which provide improved enzyme stability. can provide sex.

Polyols are, for example, propylene glycol, ethylene glycol and glycerin.

Ethanol is a particularly preferred alcohol.

The composition is from O to about 20%, preferably from about 5% to about 15%,
Most preferably it contains about 9% to about 11.41% alcohol.

formate Formate salts are, for example, sodium formate.

Formate is surprisingly much more effective than other short chain carboxylic formates such as acetate and propionate.

Formate is about 0.1% to about 10%, preferably about 0.3% to about 3% when the pH of the product is less than about 8.5.
, more preferably at a concentration of about 0.5% to about 1.5%, and when the pH of the product is about 8.5 to about 10, about 3% to about 10%, preferably about 4%. % to about 8%.

Calcium Ions Any water-soluble calcium salt can be used as a source of calcium ions, including calcium acetate, calcium formate, and calcium propionate.

The concentration of calcium ions in the composition is from about 0.1 to about 10 mmol, preferably from about 0.5 to about 1.5 mmol, per gram when the pH of the product is less than about 8.5. and the pH of the product is about 8.5 to about 10.
When the amount is about 4 to about 8 mmol.

If soap or fatty acids are present, the preferred concentration is about 2 to about 6 mmol calcium ions per 11.

Calcium ions may be replaced in whole or in part by zinc and magnesium ions.

Product pH To achieve a combination of enzyme stability and detergency, the product pH should be between about 6.5 and about 10, preferably between about 7 and about 8.5.
It is.

For cleanability, a pH of about 8.5 to about 10, especially 9 to 10, is best.

Both high and low (1) pH impair the stability of the enzyme, and low pH does not produce a high cleaning effect.

Suitable pH buffering agents include mono-, di- and triethanolamines.

Triethanolamine is the best buffering agent when the pH of the product is between 8.5 and about 10.

When soap or fatty acids are present, the preferred pH is from about 7 to about 7.5.

The balance of the composition is usually water, but the composition also contains fragrances, dyes,
Other ingredients may be included, including opacifiers, optical brighteners, suds suppressants, pH adjusters, and the like.

Disclosures of suitable components can be found in the patent specifications, which are incorporated herein by reference.

Advantageously, the product is essentially free of substances such as detergent builders that bind calcium ions, and sufficient free calcium ions are present, but with formic acid very low concentrations, especially in the low pH range, can be achieved. Excellent stability is achieved with calcium ions of

More specifically, by introducing into the composition a low concentration of calcium ions as in the present invention together with formate and alcohol, it is possible to stabilize the enzyme in the composition to an extent that was previously unimaginable. This has the advantage that precipitation, which has been a problem in the preparation of conventional aqueous detergents, is less likely to occur.

Preferred compositions comprising soap (low pH range only) In a preferred embodiment, the homogeneous aqueous detergent composition of the present invention comprises:
(a) from about 20% to about 50% by weight of organic synthetic surfactants; (b) from 3% to about 15% by weight of saturated fatty acids having 10 to 16 carbon atoms in the alkyl chain; (C ),
Enzyme from about 0.025% to about 1% by weight, (d), 0 formic acid
．． 1% to about 3% by weight; and (e) less than 2 mmoles of enzyme reach TL per kg of cleaning composition.
-accessible) Contains calcium, 20°C
The pH of the composition, measured at , is about 6.5 to 8.5.

In these preferred embodiments of the invention, the saturated fatty acids preferably have 12 to 14 carbon atoms in the alkyl chain, and the detersive enzyme is typically a protease or a mixture of protease and amylase; Accessible calcium is approximately 0.5 to 1.5 per kg of cleaning composition
present in millimolar amounts and the pH of the composition remains approximately 7.
~7.5.

These preferred compositions of the invention are substantially builder-free.

Although fatty acids and/or soaps are not considered detergent builders/sequestrants for the purposes of this invention, the compositions of the present invention do not contain more than a small amount of sequestrant.

Saturated Fatty Acids In this preferred embodiment, the saturated fatty acids range from about 3% to about 15%
%, preferably from about 5% to about 11%.

The alkyl chain contains 10 to 16 saturated fatty acids, preferably 1
It has 2 to 14 carbon atoms.

The most preferred fatty acid is lauric acid or a 5:1 to 1:1 mixture of lauric acid and myristic acid.

In addition to saturated fatty acids, the compositions of the invention may also contain certain amounts of unsaturated fatty acids having, for example, 16 to 18 carbon atoms in the alkyl chain.

Known examples of similar unsaturated fatty acids are oleic fatty acids and palmitoleic fatty acids.

Enzyme In this preferred embodiment, the enzyme component is about 0.025% to
It is incorporated in an amount of about 1%, preferably about 0.5% to about 0.2%.

Preferred proteolytic enzyme components provide the composition with a proteolytic activity of at least about 4 Anson units, preferably from about 8 to about 30 Anson units, and most preferably from about 10 to about 20 Anson units per kilogram of liquid cleaning composition. Should.

In another preferred embodiment, the enzyme component is represented by a mixture of protease and amylase.

The proteolytic activity of this mixture is as described above.

The enzyme component is about 8.0 to about 10. It is preferably characterized by having an isoelectric point of about 8.5 to about 9.5.

Formic Acid In this preferred embodiment, this component is used in an amount of from 0.1% to about 3% by weight, preferably from 0.5% to 1.5% by weight.

Water-soluble salts are preferred. Most preferred are formic acid or formate salts, such as sodium, potassium salts, lithium salts, amines and substituted amines, including mono-, di- and triethanolamines.

Enzyme-Accessible Calcium These preferred compositions of the present invention contain less than about 2 mmol, preferably 0.5 to 1.5 mmol, of enzyme-accessible calcium per kilogram of enzyme-containing homogeneous detergent product.

The compositions of the present invention are substantially free of sequestering agents, such as polyacids that can form soluble calcium complexes in the composition.

However, it is possible to use small amounts of sequestering agents, for example polyacids or mixtures of polyacids.

Enzyme-accessible calcium is defined as the amount of calcium ions that are effectively available to enzyme components.

As exemplified below, calcium sequestration resulting from, for example, a mixture of 0.5% polyphosphonate and polyacid represents from about 1 to about 1.5 mmol calcium per kilogram of product.

The total calcium incorporated into the composition consists of enzyme-accessible calcium and calcium sequestered with low concentrations of polyacids.

Therefore, from a practical point of view, enzyme-accessible calcium is calcium that is soluble in the composition in the absence of any strong sequestrants, which has a complex equilibrium constant with calcium of 1.5 or higher, for example at 20°C. be.

Product pH The pH of these preferred products is from about 6.5 to about 8.5, preferably from about 7 to about 7.5 to achieve a combination of enzyme stability and detergency.

Both high and low pH can adversely affect enzyme stability.

Optional Ingredients Preferred compositions of the present invention, in addition to the essential ingredients described above, often include a series of optional ingredients used for known functionalities in conventional concentrations.

The composition of the present invention presupposes an aqueous enzyme-containing detergent composition comprising a critical ternary system as detailed above;
It is often preferred to use phase modifiers.

This component together with water constitutes the solvent matrix for the liquid compositions of this invention.

Suitable phase modifiers are well known in liquid detergent technology;
Examples include lower aliphatic alcohols having 2 to 6 carbon atoms and 1 to 3 hydroxyl groups, diethylene glycol ethers, and lower aliphatic monoalcohols having 1 to 4 carbon atoms.

Examples of phase modifiers include ethanol, n-propanol, isopropanol, butanol, 1,2-propanediol, 1,3-propanediol, n-hexanol, monomethyl-, monoethyl-, monopropyl- and monobutyl ether and di-ethylene glycol.

Additional phase modifiers with relatively high boiling points and low vapor pressures can be used so long as they do not react with other components of the composition.

Known detergent hydrotropes are another class of phase modifiers suitable for use in the present invention.

These hydrotropes are, for example, salts of alkylarylsulfonates having up to 3 carbon atoms in the alkyl group, such as xylene, toluene, ethylbenzene, etc.
, photothorium, potassium, ammonium and ethanolamine salts of cumene and isopropylbenzenesulfonic acids.

Phase modifiers are often used in amounts of about 5% to about 20%.

The sum of phase modifier and water is usually in the range of 65% to 35%.

Preferred compositions of the invention may further include a series of optional ingredients, often used in additional concentrations, usually up to about 5%.

Similar additives include, for example, polyacids, foam control agents, opacifying agents,
Antioxidants, disinfectants, dyes, fragrances, brighteners, etc.

A representative example of a preferred additive is a polyacid or mixture of polyacids in an amount of about 1% or less.

Suitable polyacids include citric acid, cyclohexane-1,1-
Dicarboxylic acid, cyclopropane-1,1-dicarboxylic acid, dimethylmalic acid, glutaric acid, 0-oxybenzoic acid, m-oxybenzoic acid, p-oxybenzoic acid, itaconic acid, methylsuccinic acid, sodium tripolyphosphate and nitrilotriacetic acid including.

Representative examples of preferred polyacids for use in the present invention are citric acid and organic phosphonic acids and mixtures thereof.

Particularly preferred alkylene-polyamino-polyalkylenephosphonic acids are ethylenediaminetetramethylenephosphonic acid, hexamethylenediaminetetramethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid and amino-trimethylenephosphonic acid or salts thereof.

These organic phosphonic acids/salts are preferably used in amounts of 0.1% to 0.8%.

The use of suds control agents may be necessary to advantageously utilize the compositions of the present invention under various conditions of use.

Although generally any detergent suds control agent may be utilized, alkylated polysiloxanes, such as dimethylpolysiloxane, often referred to as silicones, are preferred for use in the compositions of the present invention.

Silicone is often less than 0.5%, most preferably 0.0%
It is used in concentrations of 1% to 0.2%.

It is also desirable to utilize opacifiers so long as they contribute to producing a concentrated liquid cleaning composition of uniform appearance.

Suitable opacifiers include, for example, Monsand Chemical Corporation.

The polystyrene is commercially known as LYTRON 621 manufactured by Chemical Corporation.

Opacifiers are often used in amounts of 0.3-1.5%.

The compositions of the present invention further contain known antioxidants, often radical scavengers, at concentrations established in the art, i.e. from 0.00% to 0.25% (relative to the total composition). May contain.

These antioxidants are often introduced together with fatty acids.

Although many suitable antioxidants are already known and available for this purpose, one particularly preferred for use in the compositions of the invention is 2,6-di-t-butyl-p-cresol (phthyl hydroxytoluene), BHT and 2-1-butyl-4-hydroxyanisole or 3-t-butyl-4-hydroxyanisole (more commonly known as BHA), or Butylated hydroxyanisole.

Other suitable antioxidants are 4,4'-thiobis(6-t-
butyl-m-cresol) and 2-methyl-4°6-ditunylphenol.

The following examples illustrate the invention and facilitate its understanding.

All parts, percentages and ratios are by weight unless otherwise indicated.

Example I Basic prescription The 21 day stability data follows the same general trend.

As can be seen from the above data, formate is best, followed by acetate, and then propionate.

The total abundance of Ca” is approximately 15 mmol/l (
some amount is added with the enzyme slurry).

Example ■ A liquid detergent composition was prepared by mixing the following components in the following proportions.

Composition I-■ contained 3 mmol calcium per composition 11 and compositions I-■ contained 5 mmol calcium per composition 11.

The storage stability of the compositions was determined under elevated temperature conditions (35°C, 2 and 3 weeks; 40°C, 48 hours).

Composition according to the invention 1. III, IV, VI and ■ were found to be significantly superior to comparative compositions I and ■ containing no formate stabilizer.

Instead of sodium formate, triethanolammonium formate, jetanolammonium formate, monoethanolammonium formate, potassium formate,
Substantially comparable results are obtained with compositions 1 and 2 using substantially equimolar levels of salts selected from lithium formate and ammonium formate.

Example ■ A liquid detergent composition was prepared by mixing the following components in the following proportions.

The enzymatic and physical stability of the compositions was determined under accelerated storage conditions after 2 weeks at 35°C.

Composition A is representative of the prior art, compositions B and C are control compositions based on common modifications to the prior art composition, and composition I is an example of the invention.

The amount of calcium in Compositions A and B represents the minimum amount necessary to achieve acceptable enzyme stability based on current state of the art.

The amount of calcium in Composition C was reduced to the point where phase instability and precipitation no longer occurred.

A summary of the test data is as follows.

These results indicate that formulationally closely related prior art compositions A or technical modifications of prior art formulations B;
The overall improvement in performance offered by composition I according to the invention compared to that of C is confirmed.

Comparable performance effects are obtained from the above compositions using the same molar proportions of acetic acid or propionic acid in place of formic acid.

A composition of the present invention was further prepared by mixing the following components in the following proportions.

Compositions 1 and 2 are technical modifications of the prior art;
Composition (1) is an example of the present invention.

Residual enzyme activity (expressed as % of initial activity) was determined upon exposure to accelerated storage conditions (48 hours at 40°C).

The test results were as follows.

These results demonstrate the superiority of the present invention over closely related compositions and also show that formic acid is the most preferred short chain carboxylic acid.

A series of additional compositions of the invention were prepared by mixing the following ingredients in a conventional manner.

Compositions 1-1 are clear homogeneous products with significantly improved enzyme stability, especially on storage.

The above general formulation includes alkaline buffer in the indicated proportions [
Adding citric acid to be trimmed to give the indicated product pH and the indicated proportions of CaCl
2 and by adding sodium formate.

Individual compositions were tested. As a result, the following stability was obtained.

The stability of each composition was compared to control sample A, which was low pH and contained no buffer.

TEA-containing samples (B, C, D) have their ME
It is more stable than its A counterpart (F, G, H) and the MEA sample (F, G, H) is much better than the Na2COs-containing formulation (KP).

Enzymatic degradation is inhibited as sodium formate levels increase, especially in the ethanolamine-buffer system (compare B and F, C and G, and D and H).

Addition of Ca++ (CaCl2) to the saturation point suppresses the decomposition rate (compare G and ■ and H and J).

Claims (1)

[Claims] 1(a) Detergent surfactant: 0% to about 75% (b)
Enzyme: about 0.025% to about 1% (c) Low molecular weight secondary or secondary alcohol: 0% to about 20% (d) Formate: about 0.1% to about 10% (e) 16
(f) a soluble calcium salt yielding about 0.1 to about 10 mmol of calcium ions per 10 mmol of calcium ion;
At a pH of less than about 8.5, the amount of calcium ions per
A stable aqueous enzyme composition characterized in that it is less than millimolar. 2 contains about 5% to about 15% alcohol, about 0.3 to about 3% formate, and about 0.1 to about 2 mmol calcium ions per 11, and has a pH of about 7.5 to about 8.5. The composition according to claim 1, wherein the enzyme is a proteolytic enzyme. 3. The detersive surfactant is selected from the group consisting of nonionic surfactants, anionic surfactants, cationic surfactants, zwitterionic surfactants, amphoteric surfactants and semipolar nonionic surfactants, and mixtures thereof. 3. The composition of claim 2, wherein the composition is selected from the group consisting of alcohol, methanol, ethanol, propatool and isopropyl alcohol, and mixtures thereof. 4. The composition of claim 3, wherein the surfactant is present in an amount of about 20% to about 50%. 5. The composition according to claim 3, wherein the detersive surfactant is a mixture of an anionic surfactant and a nonionic surfactant. 6. The composition according to claim 3, wherein the detersive surfactant is a mixture of a nonionic surfactant and a cationic surfactant. 7 Claim 3, wherein the detersive surfactant is a mixture of a nonionic surfactant and a semipolar nonionic surfactant.
Compositions as described in Section. 8. The composition according to claim 3, wherein the alcohol is ethyl alcohol. 9. The composition of claim 7, wherein the detersive surfactant is present at a concentration of about 20% to about 40%. 10. The composition of claim 9, wherein the formate salt is present at a concentration of about 0.5% to about 1.5%. 11 The proteolytic enzyme produces an enzyme activity level of about 15 to about 607 units per e from about 0.05% to about 0.1%.
4. The composition of claim 3, wherein the enzyme is present at a concentration of 2% and has an isoelectric point of at least about 8.5. 12. The composition of claim 11, wherein the surfactant is present at a concentration of about 20% to about 50%. 13. The composition according to claim 12, wherein the alcohol is ethyl alcohol. 14 (a) Detergent surfactant 0% to about 75%
(bJ enzyme about 0.025 to about 1% (c) low molecular weight secondary or secondary alcohol 0 to about 20% (d) water-soluble formate about 3% to about 10% (ell
a soluble calcium salt yielding from about 2 to about 10 mmol of calcium ions per e, (f) triethanolamine as an alkaline buffer, and (g) water, the remainder, such that the pH of the product is from about 8.5 to about 10. A stable aqueous enzyme composition characterized by: 15 About 5% to about 15% alcohol, about 4% to about 8% sodium formate, and about 4 to about 8 calcium ions per 1e
15. The composition of claim 14, wherein the composition contains 5 mmol, has a pH of about 9 to about 9.5, and wherein the enzyme is a proteolytic enzyme. 16 The detersive surfactant is selected from the group consisting of nonionic surfactants, anionic surfactants, cationic surfactants, zwitterionic surfactants, zwitterionic surfactants and semipolar nonionic surfactants, and mixtures thereof. Claim 15 wherein the alcohol is selected from the group consisting of methanol, ethanol, propatool and isopropyl alcohol and mixtures thereof.
Compositions as described in Section. 17. The composition of claim 16, wherein the surfactant is present in an amount of about 20% to about 50%. 18. The composition of claim 16, wherein the detersive surfactant is a mixture of an anionic surfactant and a nonionic surfactant. 19. The composition of claim 16, wherein the detersive surfactant is a mixture of a nonionic surfactant and a cationic surfactant. 20. The composition according to claim 16, wherein the detersive surfactant is a nonionic surfactant and a semipolar nonionic surfactant. 21. The composition according to claim 16, wherein the alcohol is ethyl alcohol. The 22 protein hydrolytic enzyme is present at a concentration of about 0.05% to about 0.2% resulting in an enzyme activity level of about 15 to about 60 ansons per e, and the enzyme has an isoelectric point of at least about 8.5. 17. The composition according to claim 16. 23 Claim 1 substantially free of carbonate ions
Composition according to item 6.