JPH02264789A - Production of alkyl glycoside with favorable color and smell - Google Patents

Abstract

PURPOSE:To obtain the title compound stable in its storage by decoloring with hydrogen peroxide an alkyl glycoside formed by reaction between a saccharide and alcohol followed by reaction with a compound selected from manganese dioxide, platinum-based elements, peroxidase and ascorbic acid and its salts. CONSTITUTION:First, a saccharide (e.g. glucose) and a higher alcohol are made to react, or, a saccharide is reacted with a lower alcohol followed by a higher alcohol to form an alkyl glycoside. Second, this alkyl glycoside is brought to pH >=8 with e.g. NaOH, and hydrogen peroxide is added to the system followed by e.g. agitation to effect decoloration, and 10-50000ppm. based on the pure alkyl glycoside, of a compound selected from manganese dioxide, platinum group elements (e.g. platinum), peroxidase ( e.g. catalase) and ascorbic acid and its salts is added to the system to decompose the residual hydrogen peroxide, thus obtaining the objective alkyl glycoside.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing alkyl glycosides, and more particularly to a method for producing alkyl glycosides with good color and odor.

[Prior art and problems to be solved by the invention] Although alkyl glycosides, which are sugar derivative surfactants, are mild surfactants and nonionic surfactants, they are themselves stable. In addition to generating bubbles,
It is known to act as a foam stabilizer for other anionic surfactants, and has been attracting attention in recent years.

However, although alkyl glycosides have remarkable properties as new surfactants as described above, it is also true that their actual production is accompanied by many difficulties. The biggest problem among them is that not only does the hue easily deteriorate due to various operations in the manufacturing process, but also that when the alkyl glycoside produced is stored, the hue deteriorates orally compared to immediately after storage. there were.

In particular, in order to obtain an alkyl glycoside with a good hue that causes no problems when blended into actual products, a step of decolorizing the alkyl glycoside obtained by the reaction of Wis and alcohol is essential. However, when alkyl glycosides are decolorized using hydrogen peroxide, which is conventionally known as an effective decolorizing agent, deterioration of odor such as generation of rancid odor and aldehyde odor during storage, and oral deterioration of hue. A new problem arises.

Therefore, research has been conducted to improve the hue of alkyl glycosides and to prevent the hue from deteriorating over time, that is, to stabilize the hue, and several solutions and methods have been proposed. For example, in the reaction stage where an alkyl glycoside is first produced by a reaction between a higher alcohol and a monoIII,
A method of carrying out a reaction in the presence of an acid catalyst composition comprising an acid catalyst and a reducing agent as described in JP-A-59-139397; As described in European Patent No. 0132046, a method using an acid form of an anionic activator, and a method of neutralizing with an organic base upon stopping the reaction have been proposed. In addition, in the step of separating the produced alkyl glycoside from the unreacted recovered alcohol, the color deterioration is particularly significant due to the high viscosity and poor thermal stability of the alkyl glycoside, so a method of adding a viscosity reducing agent (Japanese Patent Laid-Open No. 62-192396) The following proposals have been made:

However, even after performing these hue improvement methods,
The hue of the resulting alkyl glycoside is not satisfactory for use as is in actual products, as disclosed in JP-A-61-33.
Publication No. 193 proposes bleaching the alkyl glycoside finally obtained by production using a hydrogen peroxide and sulfur dioxide source, but in this case, the alkyl glycoside is bleached immediately after the treatment compared to before the treatment. Glycoside odor deteriorates. Furthermore, when the alkyl glycosides are stored, new problems arise such as oral deterioration of color and odor, which is not a satisfactory solution.

As described above, when alkyl glycosides are decolorized using hydrogen peroxide, there is a problem in ensuring the stability of hue and odor during storage. In other words, this point remains unresolved, and the challenge is to resolve it.

[Means to solve the problem]

The present inventors have conducted intensive studies to solve the problems encountered when decolorizing alkyl glycosides using hydrogen peroxide.
It was discovered that the deterioration in hue and odor of alkyl glycosides decolorized with hydrogen peroxide described above during storage is due to the hydrogen peroxide remaining in the alkyl glycosides after decolorization. (1) It can be efficiently decomposed by contacting with at least one selected from manganese dioxide, (II) platinum group elements, (■) peroxidase, and (IV) ascorbic acid and its salts, and such treatment can be carried out. The present invention was completed based on the finding that when this process is carried out, the resulting alkyl glycoside has extremely good stability in terms of color and odor during storage.

That is, in the present invention, sugar and higher alcohol are reacted,
Alternatively, after decolorizing the alkyl glycoside obtained by reacting sugar and lower alcohol and then reacting higher alcohol with hydrogen peroxide, (I) manganese dioxide, (n) platinum metal element, (I[[ ) peroxidase, and (IV) ascorbic acid and its salts.

In the present invention, the alkyl glycoside before decolorization with hydrogen peroxide is obtained by a well-known synthesis method, including a method in which group m and a higher alcohol are directly reacted in the presence of an acid catalyst;
Alternatively, by reacting sugars with a lower alcohol such as methanol, ethanol, propatool or butanol in advance,
It may be obtained by any method of converting it into a lower alkyl glycoside and then reacting it with a higher alcohol.

Examples of the higher alcohol used as a raw material for the alkyl glycoside according to the present invention include alcohols represented by the following formula (n).

RO(AO), H...(II) (wherein, R represents a linear or branched alkyl group or alkenyl group having 6 to 22 carbon atoms, or an alkylphenyl group, and A has 2 to 4 carbon atoms. represents an alkylene group, and n is a number whose average value is 0 to 5.) Single W class, oligosaccharide, or poly II class is used as class II which is a raw material for the alkyl glycoside according to the present invention. Specific examples of aldoses include allose, aldrose, glucose, mannose, gulose, idose, galactose, gulose, ribose,
Examples include arabinose, xylose, and lyxose. Specific examples of oligosaccharides include maltose, lactose, sucrose, maltotriose, and the like. Specific examples of polyamides include hemicellulose, inulin, dextrin, dextran, xylan, starch,
Examples include hydrolyzed starch.

The reaction for producing alkyl glycoside in the present invention is carried out using the above-mentioned starting materials and according to known methods regarding conditions such as catalyst and reaction temperature (Japanese Patent Publication No. 47-24532,
USP No. 3839318, BP No. 092355, JP 59-139397, JP 58-189195
number, etc.).

In the present invention, decolorization of alkyl glycosides with hydrogen peroxide is efficiently carried out in a system in which pi is maintained alkaline. The amount of hydrogen peroxide used for decolorization is 0.05 to 10% in purity based on the dry solid content of alkyl glycoside.
% by weight, preferably 0.1-5% by weight. The alkyl glycoside to be decolorized is used in the form of an aqueous alkyl glycoside solution containing from 15 to 75% by weight, preferably from 35 to 65% by weight of alkyl glycoside dry solids.

During the hydrogen peroxide treatment, it is preferable to maintain the pl+ of the aqueous alkyl glycoside solution at 8 or more, preferably from 8 to 14, more preferably from 8 to 12. Since the pH of the aqueous solution decreases, an alkali may be added as appropriate throughout the treatment to maintain the pH of the system at 8 or higher. To maintain pH, for example, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, or sodium carbonate,
Alkali metal carbonates, such as potassium carbonate, are used in solid form or in the form of aqueous solutions.

In the hydrogen peroxide treatment in the present invention, a required amount of hydrogen peroxide is added to an aqueous alkyl glycoside solution, and the mixture is stirred or aged for 3
This is carried out for 0 minutes or more, preferably for 1 hour or more. Hydrogen peroxide is usually added in the form of a 3 to 60% by weight aqueous solution, but there are no particular limitations.
It may be added in portions, and the treatment temperature is 5 to 100°C, preferably 20 to 80″C1, more preferably 30 to 70°C.
It is.

(I) Manganese dioxide used in the present invention, (I)
f) a platinum group element, (III) peroxidase and (I
V) Ascorbic acid and its salts can be added to the aqueous alkyl glycoside solution in the form of commonly available powders. Platinum or palladium can be used as a representative of the platinum group element (■). (Catalase can be used as a representative of II peroxidase. (I) manganese dioxide, (II) platinum group element,
(I) Peroxidase decomposes hydrogen peroxide catalytically, and (IV) ascorbic acid and its salts decompose hydrogen peroxide through a stoichiometric reaction. The amount of these used is preferably about 10 to 50,000 ppm based on the pure alkyl glycoside.

After the decomposition is completed in about 1 to 3 hours at room temperature, (1) manganese dioxide and (ff) the platinum metal element can be recovered by filtration. (■) Peroxidase and (IV) ascorbic acid and its salts dissolve in the aqueous alkyl glycoside solution, but may remain as they are in the aqueous solution.

By the above treatment, residual hydrogen peroxide in the aqueous alkyl glycoside solution can be completely decomposed. The amount of hydrogen peroxide remaining in the system can be easily measured, for example, by the iodine titration method (edited by the Pharmaceutical Society of Japan, "Commentary on Hygiene Testing Methods", p. 192, 1973).

〔Effect of the invention〕

In the present invention, an aqueous solution of an alkyl glycoside decolorized using hydrogen peroxide is mixed with a small amount selected from (I) manganese dioxide, (II) a platinum metal element, (DI) peroxidase, and (IV) ascorbic acid and its salt. (Both are characterized in that they are treated with one type of treatment, and this treatment achieves the surprising effect that the resulting alkyl glycoside maintains a good color and odor for a long period of time.)

〔Example〕

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

Example 1 (a) Decylal D-ol 11400g (72,
抛01), anhydrous glucose 3240g (1B, 抛o1
) and p-toluenesulfonic acid monohydrate 96g (0,
5n+ol) was heated and stirred in a 301 reaction tank. 95°
After raising the temperature to C, the system pressure was set to 4 + iHg to start the dehydration reaction.

At this time, Nt was blown into the reaction mixture at a rate of 5 Nf/sin to efficiently remove the generated water. After 5 hours, after confirming that glucose was completely consumed, the vacuum was released, the mixture was cooled, and the mixture was neutralized with 20 g of NaOH. After filtering out the by-product polysaccharide, 4270 g of alkyl glycoside and 8460 g of unreacted recovered alcohol were separated under distillation conditions of 130°C and 10.4 s + dg.Next, a portion of the solid content was dissolved in water to obtain a dark red 50% An aqueous alkyl glycoside solution was prepared.

400 g of this alkyl glycoside aqueous solution was heated to 45°C, and 10 g of a 3% NaOH aqueous solution was added to convert 98 to 9.
After adjusting the temperature, 4 g of 30% hydrogen peroxide (Log) was added and stirring was continued at 45° C. for 30 minutes. During this time, 3% NaOH
The pH was maintained at 8.7-9.3 by adding aqueous solution as appropriate.

(b) To this aqueous solution, 0.2 g of manganese dioxide was added at room temperature, and after stirring for 3 hours, the manganese dioxide was filtered off to obtain an aqueous alkyl glycoside solution.

The amount of residual HtOt in the obtained aqueous alkyl glycoside solution was so small that it could not be determined by iodometric titration.

Example 2 In exactly the same manner as in Example 1(a), 0.1 g of alkyl glycoside was added to an aqueous solution decolorized by f(,0) at room temperature.
After adding palladium black and stirring for 3 hours, the palladium black was filtered off to obtain an aqueous alkyl glycoside solution. The amount of residual Hgo□ in the obtained aqueous alkyl glycoside solution was so small that it could not be determined by iodometric titration.

Example 3 In exactly the same manner as in Example 1 (a), 0.2 g of alkyl glycoside was added to an aqueous solution decolorized with HtOt at room temperature.
of catalase was added and stirred for 1 hour to obtain an aqueous alkyl glycoside solution. The amounts of residual H and O in the obtained aqueous alkyl glycoside solution were so small that they could not be determined by iodometric titration.

Example 4 In exactly the same manner as in Example 1(a), 2.9 g of ascorbic acid was added to an aqueous solution of an alkyl glycoside decolorized using 810□ at room temperature and stirred for 1 hour to obtain an aqueous alkyl glycoside solution. The amount of residual 0.0 in the obtained aqueous alkyl glycoside solution was so small that it could not be determined by iodometric titration.

Example 5 In exactly the same manner as in Example 1 (Hiromichi), alkyl glycoside was
To the aqueous solution decolorized by tCh, 3.3 g of sodium ascorbate was added at room temperature and stirred for 1 hour to obtain an aqueous alkyl glycoside solution.

(Residuals in the obtained alkyl glycoside aqueous solution)! , 0° amount was a trace amount that could not be determined by iodometric titration.

Comparative Example 1 In the same manner as in Example 1(a), 0.14 wtx of H80 remained in an aqueous solution in which an alkyl glycoside was decolorized with H and Ot. This aqueous solution was directly subjected to the storage stability test of the test example.

Comparative Example 2 Alkyl glycoside was prepared from H! in exactly the same manner as in Example 1(a). To the aqueous solution decolorized with Ot, 2.2 g of sodium sulfite was added at room temperature to obtain an aqueous alkyl glycoside solution. Residual H in the obtained aqueous alkyl glycoside solution
! Ot was a trace amount that could not be determined by iodometric titration.

Test Example 1 Storage stability test for 120 hours at 50°C in air using aqueous solutions of alkyl glycosides obtained in Examples 1 to 5 and Comparative Examples 1 to 2 whose concentration was adjusted to an alkyl glycoside content of 35%. I did it.

The results are shown in Table 1.

In Table 1, the lower the Gardner value, the better the hue, and the odor was judged by five panelists.

Table 1 shows that by the method of the present invention, alkyl glycosides with good hue and odor can be obtained.

Claims (1)

[Claims] After decolorizing an alkyl glycoside obtained by reacting a sugar and a higher alcohol, or by reacting a sugar and a lower alcohol and then reacting a higher alcohol with hydrogen peroxide, (I) manganese dioxide,
(II) platinum metal element, (III) peroxidase, and (
IV) A method for producing an alkyl glycoside with good color and odor, which comprises contacting with at least one selected from ascorbic acid and its salts.