JP2706593B2 - Alkyl glycoside aqueous solution with excellent microbial stability - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous solution of an alkylglycoside which is useful as a surfactant and has excellent microbial stability.

[0002]

BACKGROUND OF THE INVENTION Alkyl glycosides, which are sugar derivative surfactants, are low-irritating surfactants having good biodegradability and are also nonionic surfactants. Nevertheless, it is known to not only generate stable foam itself, but also act as a foam stabilizer against other anionic surfactants, and is widely used as a household cleaning base. Have been.

Alkyl glycosides are prepared by directly reacting a saccharide with a higher alcohol in the presence of an acid catalyst (Japanese Patent Application Laid-Open No.
Or a method in which a saccharide is previously reacted with a lower alcohol such as butanol to form a lower alkyl glycoside and then reacted with a higher alcohol (Japanese Patent Application Laid-Open Nos. 64-71895 and 64-64). −71896
And JP-A-64-71897). Therefore, although alkyl glycosides originally have a sugar skeleton in the structure and are active agents in accordance with naturalization of raw materials and environmental orientation, they have a problem that fungi easily propagate in an aqueous solution thereof.

Conventionally, methods for preserving and preventing fungicides of surfactants include benzoic acid esters such as methyl parahydroxybenzoate and ethyl paraoxybenzoate, benzoic acids such as benzoic acid and sodium benzoate, and 1,2-benzisothiazoline. Addition of preservatives and fungicides such as -3-one is known. However, paraoxybenzoic acid esters have low water solubility, are incorporated into micelles of a surfactant in an emulsion, and do not exert sufficient effects on microorganisms in an aqueous layer. In addition, benzoic acids are effective only on the acidic side of pH, and are unsuitable as an antiseptic / fungal treatment for acid-labile alkyl glycosides. In addition, both have safety restrictions on their usage. Isothiazoles are disadvantageous in cost and cannot be used for cosmetics.

[0005] Thus, there has been a demand for the development of an effective method for preserving and preserving an aqueous solution of an alkyl glycoside. That is, an object of the present invention is to provide an aqueous solution of an alkylglycoside which is excellent in microbial stability and solves the above disadvantages.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the above problems can be solved by maintaining an aqueous solution of alkyl glycoside under specific conditions, and have completed the present invention. .

That is, the present invention provides the following condition (a):as well as
(B) satisfiedAnd alkyl in aqueous solution of alkyl glycoside
Luglycoside pure content is 10-80% by weightCharacterized by
Alkyl glycoside aqueous solution with excellent microbial stability
To offer. (B) pH9-11Has been maintained. (B) water-soluble alcohol0.1-20% by weight (based on alkyl
Glycoside aqueous solution)Contains.

[0008] The aqueous alkylglycoside solution provided by the present invention can easily prevent the growth of fungi for a long period of time, and can be applied to cosmetic applications in which the additives used are limited.

The alkyl glycoside in the present invention includes those represented by the following general formula (I). R ¹ in _{^{(OR 2) x G y ...}} (I) ( wherein, R ¹ represents a straight-chain or alkyl group having 8 to 22 carbon atoms in the branched chain, alkenyl or alkylphenyl group,, R ² are the same or Differently represents an alkylene group having 2 to 4 carbon atoms, G is a residue derived from a reducing sugar having 5 to 6 carbon atoms, x is a number having an average value of 0 to 10, and y is an average number thereof. The value is a number of 1 to 10.) The compound represented by the general formula (I) can be obtained by a known method, for example, a method in which a saccharide and a higher alcohol are directly reacted in the presence of an acid catalyst. Alternatively, it can be produced by a method in which a saccharide is previously reacted with a lower alcohol such as methanol, ethanol, propanol or butanol to form a lower alkyl glycoside and then reacted with a higher alcohol (Japanese Patent Publication No. 47-23232, US Pat.
No. 3839318, EP 092355, JP-A-58-189195.
No., JP-A-59-139397).

The higher alcohol used as a raw material for the synthesis of alkyl glycosides includes linear or branched alkyl alcohols, alkenyl alcohols, alkyl phenols having 8 to 22 carbon atoms or alkylene oxide adducts thereof.

The saccharide used as a raw material for the synthesis of an alkyl glycoside includes monosaccharides, oligosaccharides and polysaccharides. Specific examples of monosaccharides include aldoses, such as allose, altrose, glucose, mannose, gulose, idose, galactose, talose, ribose, arabinose, xylose, lyxose, and fructose of ketoses. Specific examples of oligosaccharides include maltose, lactose,
Sucrose, maltotriose and the like can be mentioned. Specific examples of polysaccharides include hemicellulose, inulin, dextrin, dextran, xylan, starch, hydrolyzed starch and the like. Among these saccharides, monosaccharides are preferred as raw materials.

The alkylglycoside pure content in the alkylglycoside aqueous solution used in the present invention is 10 to 80% by weight,
Preferably it is 30 to 50% by weight. If the alkylglycoside pure content is lower than the above range, it is economically disadvantageous, and if it is higher, the viscosity increases, which is not preferable in handling.

In the present invention, an alkaline compound is added to maintain the pH of the aqueous alkyl glycoside solution at 9 to 11 . As the alkaline compound to be used, an inorganic alkaline compound, for example, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, or an alkali metal carbonate such as sodium carbonate or potassium carbonate, or an organic alkali compound Compounds such as triethylamine, pyridine and the like can be mentioned, and a mixture thereof may be used. Preferably, a weak base, more preferably, sodium carbonate can be used. in this case,
It is not the amount of alkaline compound that is added, but the pH that is achieved by the addition
Value. By using a weak base compound having a pH buffering property, it is possible to maintain the antiseptic and antifungal performance for a longer period of time. The addition form of the alkaline compound may be either solid or liquid, or a solution, but an aqueous solution is preferred.

The water-soluble alcohol used in the present invention includes monohydric alcohols such as methanol, ethanol, propanol, isopropanol, butanol, sec-butyl alcohol and tert-butyl alcohol, as well as ethylene glycol and propylene glycol. And polyhydric alcohols such as the above, and preferably ethanol.

In the present invention, the pH is maintained at 9 to 11 by adding an alkaline compound to the aqueous solution of alkyl glycoside.
Preservatives by adding more water-soluble alcohol
Achieves anti-fungal effect and improves the appearance of aqueous solution of alkyl glycoside
Minimizing daily changes and ensuring long-term stability
Can be.

In order to completely prevent the generation of fungi only by adding an alkaline compound, a pH of more than 11 is essential, and in order to prevent the generation of fungi only by adding a water-soluble alcohol, an addition of 10% by weight or more is required. Need quantity. Although these treatments are effective merely in terms of controlling bacteria, they require a large amount of an alkaline compound and / or a water-soluble alcohol, and have drawbacks in terms of formulation.

In the present invention, the pH is adjusted to 9 to 11 by adding an alkaline compound (most preferably, sodium carbonate).
And a water-soluble alcohol (most preferably ethanol)
Is most preferably added in an amount of 0.1 to 20% by weight, more preferably 0.1 to 5% by weight. The order of adding the alkaline compound and the water-soluble alcohol may be any order.

The aqueous alkyl glycoside solution of the present invention can be used as a compounding material for various cleaning agents (eg, hair cleaning agents, clothing cleaning agents, dishwashing agents, body cleaning agents, etc.). When used as a base for such a detergent, the amount of the aqueous solution of alkyl glycoside used is preferably about 1 to 80% by weight in terms of the effective amount of alkyl glycoside.

In the above-mentioned cleaning composition, other components can be used in combination.
General anionic surfactants (alkyl sulfates, alkyl ether sulfates, α-olefin sulfonates, alkyl sulfonates, taurine surfactants, sarcosinate surfactants, isethionate surfactants, N -An acyl acidic amino acid-based surfactant,
Higher fatty acid salts, acylated polypeptides, etc.); amphoteric surfactants (alkyl betaine surfactants, amidopropyl betaine surfactants, imidazolinium betaine surfactants, sulfobetaine surfactants, phosphobetaine surfactants) Surfactants and amino acid-type surfactants such as sodium laurylaminopropionate); nonionic surfactants (coconut oil fatty acid diethanolamide, stearic acid monoglyceride, lauryl dimethylamine oxide,
Polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, fatty acid sorbitan ester, polyoxyethylene fatty acid sorbitan ester, etc.); cationic surfactants (stearyltrimethylammonium chloride, distearyldimethylammonium chloride, lanolin fatty acid aminopropylethyldimethyl ethyl sulfate) Ammonium), conventionally known humectants, thickeners, polymer compounds (such as carboxyethylcellulose, hydroxyethylcellulose, and cationized cellulose), flavors, and preservatives.

[0020]

The aqueous alkyl glycoside solution of the present invention comprises:
It is characterized in that the pH is maintained at 9 to 11 by the addition of an alkaline compound, and that it contains a water-soluble alcohol. The surprising effect of keeping good over a long period of time is achieved.

[0021]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples.

The effects in the following examples were determined by the following test methods. <Test Method> An appropriate amount of general bacteria (or fungi) was suspended in sterilized water, and the total number of each bacteria was 10 ⁶ to 10 ⁷ cells / ml (10
Prepare a bacterial suspension so as to obtain ⁴ spores / ml). 1 ml of this bacterial suspension is added to 100 g of the sample, and the mixture is allowed to stand for 4 weeks in a thermostat at 30 ° C., and the number of viable cells per 1 g of the sample is measured.

[0023]-size constant bacteria number less than 100 pieces: - (good antiseptic and antifungal effect with) the viable cell number more than 100 less than 1000: - (antiseptic and antifungal effect with) the viable cell number 1000 or more: + ( Examples 1 to 4 and Comparative Examples 1 to 2 Using an aqueous solution of dodecyl glucoside (30% by weight of pure content), various antiseptic and fungicidal treatments as shown in Table 1 were prepared. The effect was determined using a test method. Table 1 shows the results.

[0024]

[Table 1]

Examples 5 to 7 , Comparative Example 3 Using an aqueous solution of decylglucoside (pure content: 40% by weight), Table 2
Samples which had been subjected to various antiseptic and antifungal treatments as shown in Table 1 were prepared, and their effects were determined using the above test methods. In this case, for the purpose of examining the daily change of the preservative and fungicidal effects, the sample was stored at 40 ° C. for one month, and then a bacterial suspension was added and tested. Table 2 shows the results.

[0026]

[Table 2]

Examples 8 to 10 In order to examine the antiseptic and fungicidal effects in more detail, samples which had been subjected to various antiseptic and antifungal treatments as shown in Table 3 were prepared using an aqueous solution of decylglucoside (40% by weight of pure content). In the above test method, the number of culture days (1 day, 3 days, 7 days, 4 weeks)
And the number of viable bacteria was examined to determine the effect. Table 3 shows the results.

[0028]

[Table 3]

Claims (2)

(57) [Claims] (1) The following conditions (a) and (b) are satisfied , and
Pure alkyl glycosides in aqueous ruglycoside
An aqueous solution of an alkyl glycoside having excellent microbial stability, characterized in that it is 10 to 80% by weight . (A) The pH is maintained at 9-11 . (B) 0.1-20% by weight of water-soluble alcohol (based on alkyl)
Aqueous glycoside solution) . Wherein alkyl glycoside aqueous solution having excellent microbial stability according to claim 1, wherein a water-soluble alcohol is ethanol and / or isopropyl alcohol.