DK146910B - Aqueous, enzyme-containing, liquid detergent product - Google Patents

Description

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14691 O.

The present invention relates to an aqueous enzyme-containing liquid detergent product with improved storage stability.

Liquid detergent products are well known and, following renewed interest in enzymes for incorporation in detergent products, several proposals have been made for such enzyme-containing liquid detergent products.

Despite these proposals, enzyme-containing liquid detergent products have not come to the market to any appreciable extent, primarily because of the serious problems of instability encountered by the incorporation of enzymes into liquid detergent products. These problems are commonly known and are e.g. have been proposed to reduce the instability of enzymes in liquid detergent products by incorporating stabilizing systems therein.

Thus, e.g. Japanese Patent Application No. 47 / 35,192, filed November 24, 1972, proposed to prepare liquid stabilized enzyme preparations, including enzyme-containing liquid detergent products, by incorporating therein a combination of polyalcohols and borax. According to the Japanese application, these polyalcohols, the examples of which are sorbitol and glycerol, are used in an amount of at least 5% by weight of the final product and preferably in an amount of 10-30% by weight, while the borax is used in an amount of at least 20, preferably 50-100% by weight of the polyalcohol, and the weight ratio of polyalcohol to borax in the product must therefore be equal to or greater than 1. The products of said Japanese application description have, as experimentally determined by repeating Example 1 therein, a pH value 30 in the range of 3.9-7.4.

It has now been found that the storage stability of enzyme-containing liquid detergent products incorporating a stabilization system comprising one or more polyhydroxy compounds and boric acid or an equivalent boron compound can be significantly improved when the weight ratio of polyhydroxy compounds to boric acid or the corresponding 2 equivalent compound is less than 1 (calculated as borax) and when the pH is above 7.5, preferably between 8.5 and 11.0 (at 25 ° C). Accordingly, the product of the type containing a stabilizing system comprising 5 a) 4-25% by weight, based on the final product, is of one or more polyhydroxy compounds containing only C, H and O atoms and containing 2-6 hydroxy groups, and b) boric acid, boron trioxide or an alkali metal ortho, meta or tetraborate, including borax, and it is characterized in that the weight ratio (a): (b) where (b) ) is calculated as borax, is less than 1 and the product has a pH of 7.5--11.0. Compared to the combinations of the aforementioned Japanese patent application, the detergent of the present invention exhibits a significantly improved enzyme stabilizing effect.

The polyhydroxy compounds used in the detergent product of the invention contain only C, H and O atoms and are free of other (functional) substitution atoms such as N, S and the like. The polyhydroxy compounds contain at least two hydroxy groups and may contain up to six hydroxy groups. Typical examples of polyhydroxy compounds particularly suitable for use in the detergent of the invention are diols such as 1,2-propanediol, ethylene glycol and cis-3,4-dihydroxytetrahydrofuran, as well as polyols such as glycerol, sorbitol and mannitol.

The polyhydroxy compound is present in an amount of at least 4% by weight of the final product up to 25%, and preferably the amount is in the range of 5-15% by weight of the final product.

The boron compound is used in such an amount that the weight ratio of the polyhydroxy compound to the boron compound becomes less than 1 (calculated as borax), which means that the boron compound is used in an amount of more than 100% of the amount of the polyhydroxy compound. Generally, the amount 35 ranges from> 100-200 wt% and preferably from> 100-160 wt% of the polyhydroxy compound.

3 1Λ 6 910 ο The weight ratio of the polyhydroxy compound to boric acid or its equivalent is less than 1 and generally from 0.5 up to just below 1.

The aqueous, enzyme-containing liquid detergent products of the invention incorporating the stabilization systems may be simple solutions, but are preferably aqueous liquid detergent products containing as essential ingredients enzymes, surfactants and water, and the pH is above 7.5, preferably between 8.5 and 11.0 or adjusted thereto in a suitable manner.

The incorporated enzymes may be proteolytic, amylolytic, and cellulolytic enzymes as well as mixtures thereof, and they may be of any suitable origin, e.g. of vegetable, animal, bacterial and fungal origin, e.g. derived from yeast. However, their choice is determined by several factors / such as optima for pH activity and / or stability, as well as thermostability and stability to surfactants and builder substances, and in this regard bacterial or fungal enzymes are preferred, e.g. bacterial amylases and 20 proteases and fungal cellulases. The invention is of particular importance for enzyme-containing liquid detergents containing bacterial proteases for which the pH optimum is in the range of 8.0 to 11.0, but enzymes with a somewhat lower or higher pH optimum can also be used advantageously in the products of the invention.

Suitable examples of the mentioned proteases are the subtilisins obtained from various strains of B. subtilis and B. licheniformis, e.g. the commercially available subtilisins "Maxatase" ® (from Gist-Brocades N.V., Delft, The Netherlands) and 30 "Alcalase" ® (from Novo Industri A / S, Copenhagen, Denmark).

As will be appreciated, the detergent product of the present invention is of particular importance for incorporating enzymes with optima for pH activity and stability above 8.0, which enzymes are commonly referred to as high-alkaline enzymes 35 and are the most detergent enzymes with the highest bleeding capacity for stiffeners. stains, borders and shields of proteinous origin.

o 146910 4 Particularly suitable is a protease obtained from a Bacillus strain and having maximum activity throughout the pH range 8-12, which was developed and negotiated by Novo Industri A / S under the designation "Esperase" ®. The preparation of this enzyme and 5 analogous enzymes is disclosed in British Patent Specification No. 1,243,784.

High-alkaline amylases and cellulases can also be used, e.g. ct-amylases from a special strain of B. licheni-formis as described in detail in British Patent Specification No. 1,296,839.

The amount of enzymes present in the liquid product can range from 0.001 to 10% by weight and is preferably from 0.01 to 5% by weight.

The liquid detergent products of the invention may contain, as essential ingredient, an additional surfactant which may be an alkali metal or alkanolamine soap of a C Cø <24 24 fatty acid, including polymerized fatty acids, or an anionic, nonionic, cationic, zwitterionic or amphoteric surfactant or a mixture of several such surfactants.

Examples of anionic surfactants are salts (including sodium, potassium, ammonium and substituted ammonium salts such as mono-, di- and triethanolamine salts) of Cg-C₂ alkyl alkylbenzenesulfonates, primary or secondary Cg-C22₂ alkanesulfonates , C--C₂ ^ olefin sulfonates and sulfonated polycarboxylic acids prepared by sulfonation of the pyrolyzed product of alkaline earth metal citrates e.g. as described in British Patent Specification No. 1,082,179, as well as C C-C C₂ alkyl sulfates and Cg-C₂ alkyl alkyl polyglycol ether sulfates (containing up to 10 moles of ethylene oxide). Further examples are described in 30 "Surface Active Agents and Detergents" (Volumes I and II by Schwartz, Perry and Berch).

Examples of nonionic surfactants are the condensation products of ethylene oxide, propylene oxide and / or butylene oxide with C C-C ^ g alkyl phenols, primary or secondary aliphatic Cg-C ^ g alcohols, and C8 C18 fatty acid amides. Further examples of nonionic surfactants include tertiary amino oxides having one C C-C ^ alkyl chain and two C ^-Cg alkyl chains. In the above-mentioned work, further examples of nonionic surfactants are also described.

The average number of moles of ethylene oxide and / or propylene oxide in the aforementioned nonionic surfactants ranges from 1 to 30, and mixtures of various nonionic substances, including mixtures of nonionic substances with lower and higher alkoxylation degree, may also used.

Examples of cationic surfactants are the quaternary 10 ammonium compounds such as alkyl dimethyl ammonium halides, but such cationic substances are less preferred for incorporation into enzyme-containing detergent products.

Examples of amphoteric or zwitterionic surfactants are N-alkylamino acids, sulfobetaines and condensation products of fatty acids with protein hydrolysates, but because of their relatively high cost, these substances are usually used in combination with an anionic or a nonionic surfactant.

Mixtures of the various types of surfactants can also be used, and particularly mixtures of an anionic and a non-20-ionic surfactant are preferred. Furthermore, soaps (in the form of their sodium, potassium and substituted ammonium salts such as triethanolamine salts) can be used of C C Q-C₂ ^ fatty acids as well as of polymerized fatty acids, preferably together with an anionic and / or a nonionic surfactant. } and such constituents can have a favorable influence on the foaming properties of the final detergent product.

The amount of the surfactant can vary from 10 to 60% by weight, and when mixtures of e.g. the anionic and nonionic substances, the weight ratios therebetween vary from 1: 1 to 1:10. When also incorporating a soap, the amount thereof is 1-40% by weight.

Although the liquids may contain up to 40% by weight of a suitable builder, such as sodium, potassium and ammonium or substituted ammonium pyro and tripolyphosphates, 35 nitrilotriacetates, ether polycarboxylates, citrates, carbonates, orthophosphates and polyelectrolytes such as polyvinyl 146910 nyl methyl ether / maleic anhydride copolymers, the detergent product of the invention offers particular advantages when it does not contain builder substances.

The amount of water in the detergent product of the invention 5 can range from 5 to 70 weight percent.

In the liquid, aqueous, enzyme-containing detergent products of the invention, other conventional materials such as e.g. dirt suspending agents, hydrotropes, corrosion inhibitors, dyes, perfumes, silicates, optical brighteners, foam promoters, foam depressants, germicides, anti-bleaching agents, fabric softeners, and oxygen-releasing bleaches such as sodium perborate or peroxide or peroxide or peroxide or peroxide, or peroxide or peroxide or peroxide or peroxide other usual additions.

The pH of the final product is higher than 7.5 and is preferably in the range of 8.5 to 11.0 and, if necessary, adjusted to a value in this range by the addition of a suitable buffer system (eg with dimethylglycine).

The following examples are intended to illustrate the detergent of the invention. In the examples, all percentages are by weight and the extension of the enzyme half-life is determined as follows:

A continuously sampled sample from the solution under investigation is diluted continuously (1: 200) and continuously tested for enzymatic activity (for proteolytic activity, casein is used as substrate). The logarithms for the residual activity are then plotted as a function of time and the velocity constant of the first order is calculated.

The elongation factor for the enzyme half-life (F ^) is defined as Κχ (without stabilization system) = V1 (with stabilization system) - - "= (with stabilization system) (without stabilization system) where T ^ 2 is the time when the enzymatic activity (y) 35 is half the enzymatic activity at the beginning.

o 7 U6910

Example 1.

A number of experiments with the bacterial protease "Alcalase" ® from Novo are carried out in aqueous systems comprising pr. liter 5 0.2 M pentane sodium tripolyphosphate 0.12 M dimethylglycine 1.7 g Alcalase ® (activity 10.6 AU / g)

This system has a pH of 10.0 and the temperature is 57 ° C. The rate of loss of enzyme activity is measured in this system with and without the stabilization systems, and the elongation factor for the enzyme half-life (F +) is determined with the following result:

Stabilization System Weight F 15 Polyhydroxyforb. Borax P B B value

No. (P) __ (B) ____ 1 ethylene glycol + 10 15.4 0.649 16.7 2 +6 9.2 0.652 8.3 3 "10 1.9 20 4 glycerol + 10 10.3 0.970 14.7 5" 10 1.8 6 1,2-propanediol + 6 7.5 0.8 6.7 7 sorbitol + 10 10.5 0.952 3.9 8 +10 5.2 1.923 2.6 25 9 "10 1.7 10 mannitol + 10 10.5 0.952 3.2 11 "+ 10 5.2 1.923 2.3 12" 10 1.8 30 These results show the increased Ft values obtained with the detergent product of the invention. Experiments Nos. 8 and 11 are not according to the invention (Ρ / Β,> 1) and shows that with these ratios, significantly reduced F 2 values are obtained compared to that obtained with P / B <1. Experiments Nos. 7-9 and 10-12 35 shows that a decrease in the P / B ratio yields better F 1 values, which is in contrast to the prior art, which states that the P / B ratio must be ^ 1. , 8 and 9.45% phorax alone (no polyhydroxy compound added), Ft values of 1.0, 1.3, 1.8 and 2.4 are obtained, respectively.

Example 2.

In this series of experiments, the bacterial protease "Esperase" ® (activity 41.5 KNPU / g) is used. The aqueous system is used in Example 1, but the temperature is 60 ° C. With 4% cis-3,4-dihydroxytetrahydrofuran and 7.4% borax (P / B = 0.54) two, an F 2 value of 2.5 is obtained.

Example 3

Similar to Example 1, systems with the bacterial α-amylase "Thermamyl" ® are tested. The aqueous system 15 contains per ml. liter of 0.12 M pentane sodium tripolyphosphate 0.1 M glycine 0.5 g of "Thermamyl" ® (activity 450 KNU / g). The pH is 9.95 and the temperature is 59.3 ° C. With a stabilization system containing 6% ethylene glycol + 9.2% borax (P / B ratio = 0.65), a Ft value of 2.2 is obtained.

Example 4

Example 1 is repeated with a stabilization system containing 10% glycerol and varying amounts of borax. The following result is obtained: o 9 146910

Glycerol Borax (%) P / B ratio F 2 value a) 10% everywhere 14 0.71 11.6 b) 12 0.83 12.8 c) 11 0.91 14.1 5 d) 10.6 0.94 14.2 e) 10.35 0.97 14.7 f) 1.0 1.0 10.0 g) 8 1.25 6.8 h) 6.25 1.6 4.7 10 i) 52 3.4 j) 2.5 4 2.3 k) 0 - 1.8