JP2021147357A - HYDROXY FATTY ACID ACYL-N-(2-HYDROXYETHYL)-β-ALANINE OR SALT THEREOF - Google Patents

Abstract

To provide hydroxy fatty acid acyl-N-(2-hydroxyethyl)-β-alanine or a salt thereof, which shows good humectant feeling during cleaning, forms easily spreadable bubbles which show good wash feeling, and shows high emulsion stability.SOLUTION: Provided is hydroxy fatty acid acyl-N-(2-hydroxyethyl)-β-alanine or a salt thereof, represented by Formula (1). (R is a C6-C22 hydroxyalkyl group; and M is H, alkali metal, 1/2 alkaline earth metal, organic ammonium, or amino acid salt.)SELECTED DRAWING: None

Description

The present invention relates to acyl amino acids or salts thereof, and more particularly to hydroxy fatty acid acyl-N- (2-hydroxyethyl) -β-alanine or salts thereof.

Acylamino acids or salts thereof, which are widely known as amino acid-based surfactants, are used as detergents, foaming agents, surface treatment agents, metal dispersants and the like. In particular, acyl amino acid salts are preferably blended in detergent compositions such as shampoos, body soaps, and facial cleansers as ingredients that are less irritating and are gentle to the skin and are in line with the natural-oriented concept that is spreading among consumers. ing.

For example, as a cleaning agent having excellent foaming property, detergency, and water resistance, and which can give an excellent feeling of use with a moist feeling, Patent Document 1 and Patent Document 2 describe acyl-N-hydroxyalkyl-β-alanine. Salt has been proposed.

However, although these compounds are excellent in moisturizing feeling, they may be inferior in comfortable cleaning feeling due to being wrapped in foam. Further, even in the case of high foaming property, if foam with less moisture is formed, the foam cannot be spread and spread, and a comfortable cleaning feeling may not be satisfied.

Further, although these compounds are excellent in detergency, they may be insufficient in emulsion stability related to prevention of reattachment of stains and preparation of O / W type compositions.

Therefore, there is a demand for an acylamino acid or a salt thereof, which has an excellent moisturizing feeling during washing, exhibits good washing comfort by easily spreading bubbles, and exhibits high emulsion stability.

Japanese Unexamined Patent Publication No. 64-90295 Japanese Unexamined Patent Publication No. 11-12240

Therefore, the problem to be solved by the present invention is to provide an acylamino acid or a salt thereof, which is excellent in moisturizing feeling during washing, forms an easily spreadable foam showing good washing comfort, and shows high emulsion stability. be.

As a result of diligent studies by the present inventors in order to solve the above problems, the amino acid moiety is N- (2-hydroxyethyl) -β-alanine and the hydrophobic moiety is a hydroxy fatty acid, whereby a moisturizing feeling during washing is used. The present invention has been completed by finding that an acylamino acid or a salt thereof, which is excellent in quality, forms an easily spreadable foam showing good washing comfort, and shows high emulsion stability, can be obtained.
That is, the present invention is as follows.
General formula (1):

(In equation (1),

Indicates a hydroxy fatty acid acyl group having 6 to 22 carbon atoms, and M represents a hydrogen atom, an alkali metal, a 1/2 alkaline earth metal, an organic ammonium or an amino acid salt. )
Hydroxy fatty acid acyl-N- (2-hydroxyethyl) -β-alanine represented by, or a salt thereof.

When the hydroxy fatty acid acyl-N- (2-hydroxyethyl) -β-alanine of the present invention or a salt thereof is used, it is excellent in moisturizing feeling during washing and forms an easily spreadable foam showing good washing comfort, and is highly emulsified. The effect of showing stability is obtained.

Hereinafter, embodiments of the present invention will be described.
The hydroxy fatty acid acyl-N- (2-hydroxyethyl) -β-alanine or a salt thereof of the present invention is represented by the general formula (1).

In equation (1)

Indicates a hydroxy fatty acid acyl group having 6 to 22 carbon atoms. In the present specification, the "hydroxy fatty acid acyl group having 6 to 22 carbon atoms" means an acyl group derived from a saturated or unsaturated hydroxy fatty acid having a linear or branched chain having 6 to 22 carbon atoms. The number of carbon atoms is preferably 10 to 20. If the number of carbon atoms of the hydroxy fatty acid acyl group is too small, the moisturizing sensation during washing may not be felt, and the ease of foam spread and the emulsion stability may be inferior. On the other hand, if the number of carbon atoms of the hydroxy fatty acid acyl group is too large, the foam spreadability and emulsion stability may be inferior.

In the formula (1), the number of hydroxy groups in the hydroxy fatty acid acyl group is 1, and it is bonded on the main chain of the fatty acid.

In one embodiment of the invention, the hydroxy fatty acid acyl group is preferably an acyl group derived from a linear saturated hydroxy fatty acid having 12 to 18 carbon atoms and having one hydroxy group on the main chain.

Examples of the above-mentioned hydroxy fatty acid acyl group include 2-hydroxycaproyl, 3-hydroxycaproyl, 6-hydroxycaproyl, 2-hydroxycapryloyl, 3-hydroxycapryloyl, 8-hydroxycapryloyl and 2-hydroxy. Caprinoyle, 3-hydroxycaprinoil, 10-hydroxycaprinoyle, 2-hydroxylauroyl, 6-hydroxylauroyl, 12-hydroxylauroyl, 3-hydroxymyristoyl, 2-hydroxypalmitoyle, 3-hydroxypalmitoyle, 16-hydroxypalmitoyle, Examples include 12-hydroxystearoyl and ricinole oil. Among these, 3-hydroxycaprinoyl, 6-hydroxylauroyl, 3-hydroxymyristoylate, 3-hydroxypalmityl, 12-hydroxystearoyl, and ricinore oil are preferable, and 6-hydroxylauroyl, 3-hydroxypalmitoyl, are more preferable. 12-Hydroxystearoyl.

M in the formula (1) represents a hydrogen atom, an alkali metal, a 1/2 alkaline earth metal, an organic ammonium or an amino acid salt. Examples of the alkali metal include sodium and potassium, and examples of the alkaline earth metal include magnesium and calcium. Examples of organic ammonium include monoethanolammonium, diethanolammonium, and triethanolammonium. Further, the amino acid salt is a salt formed by an amino acid and an alkali metal, an amino acid and a 1/2 alkaline earth metal, or an amino acid and an organic amine, and acts as a counter ion of an acyl amino acid. Amino acids that form amino acid salts include, for example, valine, leucine, isoleucine, histidine, lysine, methionine, phenylalanine, threonine, tryptophan, asparagine, aspartic acid, alanine, arginine, cysteine, glutamine, glutamic acid, glycine, proline, serine, Examples thereof include tyrosine, N-methylglycine, N-methyl-β-alanine, N- (2-hydroxyethyl) -β-alanine, taurine and methyltaurine. Examples of the alkali metal and alkaline earth metal forming the amino acid salt include those exemplified above. Examples of the organic amine forming the amino acid salt include monoethanolamine, diethanolamine, triethanolamine and the like. M is preferably sodium, potassium, triethanolammonium, taurine sodium salt, taurine potassium salt, taurine triethanolamine salt, more preferably sodium, potassium, taurine sodium salt, taurine potassium salt, and particularly preferably. It is sodium.

Examples of the salt of the hydroxy fatty acid acyl-N- (2-hydroxyethyl) -β-alanine of the present invention include 12-hydroxystearoyl-N- (2-hydroxyethyl) -β-alanine sodium and 12-hydroxystearoyl-. N- (2-Hydroxyethyl) -β-alanine taurine sodium and the like can be mentioned.

The hydroxy fatty acid acyl-N- (2-hydroxyethyl) -β-alanine or a salt thereof of the present invention reacts a hydroxy fatty acid or a derivative thereof with N- (2-hydroxyethyl) -β-alanine or a salt thereof. It can be manufactured by.

The hydroxy fatty acid derivative is not particularly limited, and examples thereof include hydroxy fatty acid ester, hydroxy fatty acid anhydride, and hydroxy fatty acid chloride.

Examples of the N- (2-hydroxyethyl) -β-alanine salt include N- (2-hydroxyethyl) -β-alanine sodium and N- (2-hydroxyethyl) -β-alanine potassium.

As a method for producing the hydroxy fatty acid acyl-N- (2-hydroxyethyl) -β-alanine or a salt thereof of the present invention, Schotten-Bau using hydroxy fatty acid chloride and N- (2-hydroxyethyl) -β-alanine sodium. The Baumann reaction is preferred.

In addition, when a hydroxy fatty acid or a derivative thereof is reacted with N- (2-hydroxyethyl) -β-alanine or a salt thereof, the hydroxy group and the carboxy group are contained in the hydroxy fatty acids, the hydroxy fatty acid derivatives, or in each molecule. A reaction may occur. For the purpose of preventing this, the hydroxy group of the hydroxy fatty acid or the hydroxy fatty acid derivative can be protected and then reacted with N- (2-hydroxyethyl) -β-alanine or a salt thereof.

The protective group that protects the hydroxy group is not particularly limited, and is, for example, a methyl group, a benzyl group, a tert-butyl group, an acetyl group, a pivaloyl group, a benzoyl group, a phosphite ester group, a trimethylsilyl group, and tert-butyldimethyl. Examples thereof include a silyl group and a triisopropylsilyl group. Of these, a tert-butyl group, a pivaloyl group, a benzoyl group, a phosphite ester group, a trimethylsilyl group, a tert-butyldimethylsilyl group and a triisopropylsilyl group are preferable.

The hydroxy fatty acid acyl-N- (2-hydroxyethyl) -β-alanine or a salt thereof of the present invention can be obtained, for example, by the following method.

To N- (2-hydroxyethyl) -β-alanine or a salt thereof, 0.5 to 3 times the molar amount of hydroxy fatty acid chloride is added dropwise and reacted in an aqueous solution. The amount of the hydroxy fatty acid chloride added is preferably 0.5 to 1.2 times the molar amount. If the amount added is too small, the residual amount of N- (2-hydroxyethyl) -β-alanine or a salt thereof may be too large to be economical, and if the amount added too much, a large amount of hydroxy fatty acid is produced as a by-product. I have something to do.

The pH of the solution when the hydroxy fatty acid chloride is added and reacted is preferably 8 to 13, and more preferably 10 to 13. If the pH is too low, the reaction will take a significant amount of time to proceed and may be uneconomical. On the other hand, if the pH is too high, the hydrolysis of the added hydroxy fatty acid chloride is promoted, and the yield may decrease with the by-product of the hydroxy fatty acid.

During this reaction, hydrochloric acid is generated, but the generated hydrochloric acid can be neutralized by adding an alkaline substance as appropriate or intermittently to maintain a preferable pH. Examples of the alkaline substance include sodium hydroxide, potassium hydroxide, ammonia, triethylamine, pyridine and the like. Of these, sodium hydroxide is preferred.

Further, as the reaction solvent, in addition to water, acetone, methanol, ethanol, isopropanol, n-butanol, iso-butanol, tert-butanol and the like can be mixed, if necessary. Isopropanol and tert-butanol are preferable as the solvent to be mixed.

The solution temperature when the hydroxy fatty acid chloride is added and reacted is preferably 0 to 80 ° C, more preferably 10 to 60 ° C, and even more preferably 20 to 45 ° C. If the temperature is too low, the reaction may be significantly slowed down, and if the temperature is too high, the yield may decrease with the by-product of hydroxy fatty acids.

During this reaction, heat is generated due to the dropping of the hydroxy fatty acid chloride, which causes the solution temperature to rise. Therefore, in order to maintain a preferable temperature, the solution temperature before the reaction is adjusted to around 20 ° C., the hydroxy fatty acid chloride. Can take general measures such as gradually dropping over an hour or more to prevent a rapid temperature rise, cooling the solution, and the like.

The reaction time of the above reaction is, for example, 1 to 20 hours.

The reaction solution after this reaction can be used as a solution for desired purposes after salt exchange by a conventional method, but after neutralization with an acidic substance such as hydrochloric acid, sulfuric acid, or phosphoric acid, solvent extraction, crystallization, etc. Hydrochloric acid fatty acid acyl-N- (2-hydroxyethyl) -β-alanine can also be isolated. Further, the isolated acid-type hydroxy fatty acid acyl-N- (2-hydroxyethyl) -β-alanine can be salted or adjusted in pH in water and used as an aqueous solution in a desired application.

When a hydroxy fatty acid chloride having a protected hydroxy group is used, it is deprotected by using an appropriate method suitable for the protecting group, and the hydroxy fatty acid acyl-N- (2-hydroxyethyl) -β- of the present invention is used. Alanin or a salt thereof can be obtained.

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

[Example 1]
12-Hydroxystearoyl-N- (2-hydroxyethyl) -β-alanine sodium aqueous solution 40% by weight (2-hydroxyethyl) -β-alanine sodium aqueous solution 77.6 g (0.20 mol), ion-exchanged water 160.3 g, 216.4 g of tert-butanol was added to a solution of 18.3 g (0.22 mol) of a 48 wt% sodium hydroxide aqueous solution, and the mixture was stirred. 68.4 g (0.18 mol) of phosphite-protected 12-hydroxystearic acid chloride was added dropwise thereto over 1 hour, and then the mixture was aged for 1 hour. During this time, the solution temperature rose from 20 ° C to 40 ° C and the pH remained between 10 and 13. Next, sulfuric acid was added to adjust the pH to 2, and the organic layer and the aqueous layer were separated and desalted. Then, tert-butanol was distilled off under reduced pressure to deprotect the phosphite ester under alkaline conditions. Finally, 35% by weight hydrochloric acid and 48% by weight sodium hydroxide were added to adjust the pH to 8, to obtain an aqueous solution of 12-hydroxystearoyl-N- (2-hydroxyethyl) -β-alanine.

[Example 2]
3-Hydroxypalmitoyl-N- (2-hydroxyethyl) -β-alanine sodium aqueous solution Subphosphate-protected 3-hydroxypalmitate chloride was used in place of the phosphite-protected 12-hydroxystearate chloride. Except for the above, the same operation as in Example 1 was carried out to obtain an aqueous solution of 3-hydroxypalmitoyl-N- (2-hydroxyethyl) -β-alanine sodium.

[Example 3]
6-Hydroxylauroyl-N- (2-Hydroxyethyl) -β-Alanine Sodium Aqueous Solution A phosphate ester-protected 6-hydroxylaurate chloride was used in place of the phosphite-protected 12-hydroxystearate chloride. Except for the above, the same operation as in Example 1 was carried out to obtain an aqueous solution of 6-hydroxylauroyl-N- (2-hydroxyethyl) -β-alanine sodium.

[Comparative Example 1]
4-Hydroxybutanoyl-N- (2-Hydroxyethyl) -β-Alanine Sodium Aqueous Solution Use phosphite-protected 4-hydroxybutanoic chloride instead of phosphite-protected 12-hydroxystearate chloride. The same operation as in Example 1 was carried out to obtain an aqueous solution of 4-hydroxybutanoyl-N- (2-hydroxyethyl) -β-alanine sodium.

[Comparative Example 2]
2-Hydroxylignoseroyl-N- (2-hydroxyethyl) -β-alanine sodium aqueous solution Hydrate ester-protected 2-hydroxylignoserate chloride instead of phosphite-protected 12-hydroxystearate chloride The same operation as in Example 1 was carried out except that the aqueous solution of 2-hydroxylignoseroyl-N- (2-hydroxyethyl) -β-alanine sodium was obtained.

[Comparative Example 3]
Aqueous solution of stearoyl-N- (2-hydroxyethyl) -β-alanine sodium stearate was used instead of phosphite-protected 12-hydroxystearate chloride, except that deprotection due to alkaline conditions was removed. The same operation as in Example 1 was carried out to obtain an aqueous solution of stearoyl-N- (2-hydroxyethyl) -β-alanine sodium.

[Evaluation of acyl amino acid salts]
(1) Ease of spreading bubbles 50 g of each acyl amino acid salt aqueous solution diluted with purified water was prepared so as to have an effective content of 1% by weight, placed in a bowl, and whipped with a hand mixer for 30 seconds. One teaspoon (3 cm in diameter) of foam was taken from the formed foam and placed on the vicinity of one end of 20 cm × 10 cm artificial leather. After that, the ruler was artificially made using a simple coater with a ruler of 3 cm in height and 18 cm in width attached to the handle for the adhesive roller (TOOL-L-3000, Nippon CIC Giken Co., Ltd., height 4 cm x width 30 cm to the shaft). Foam was spread toward the opposite end of the artificial leather, making it perpendicular to the leather. At this time, the distance until the width of the bubbles became 1.5 cm (half of the initial 3 cm) or less was measured. The starting point of the distance was the end of the bubble diagonal to the traveling direction. Based on this measured distance, evaluation was made on a four-point scale of "◎", "○", "Δ", and "×" according to the following evaluation criteria. The case where the evaluation was "◎" and the case where the evaluation was "○" were regarded as acceptable.
<Evaluation criteria>
⊚: Distance is 90 mm or more ○: Distance is 80 mm or more and less than 90 mm Δ: Distance is 70 mm or more and less than 80 mm ×: Distance is less than 70 mm

(2) Emulsion stability 50 g of each acyl amino acid salt aqueous solution diluted with purified water was prepared in a 100 mL beaker (diameter 54 mm) so as to have an effective content of 5% by weight, and 1% by weight of olive oil was added. After stirring for 3 minutes, the time until the oil film formed 14 mm (a quarter of the diameter of the beaker) or more was measured. Based on the measured time, evaluation was made on a four-point scale of "◎", "○", "△", and "×" according to the following evaluation criteria. The case where the evaluation was "◎" and the case where the evaluation was "○" were regarded as acceptable.
<Evaluation criteria>
⊚: 25 minutes or more ○: 20 minutes or more and less than 25 minutes Δ: 15 minutes or more and less than 20 minutes ×: less than 15 minutes

(3) Moisturizing feeling during washing A usability test was conducted by 20 panelists. A solution obtained by diluting each of the acylamino acid salt aqueous solutions with purified water so as to have an effective content of 10% by weight was picked up, and the whole forearm was washed for 5 seconds by whipping by hand while soaking in water. Then, it was allowed to stand for 15 seconds, and the moisturizing feeling during washing was evaluated according to the following absolute evaluation criteria. The total score of each panelist was calculated, and based on the total score, evaluation was made on a four-point scale of "◎", "○", "△", and "×" according to the following evaluation criteria. The case where the evaluation was "◎" and the case where the evaluation was "○" were regarded as acceptable.
<Absolute evaluation criteria>
(Score): (Evaluation)
3: The forearm is covered with foam, and you can feel a sufficient moisturizing feeling.
2: The forearm is not covered with foam, but you can feel the moisturizing feeling.
1: The forearm is not covered with foam, and you cannot feel the moisturizing feeling.
0: The forearm is not covered with foam, and not only the moisturizing feeling cannot be felt, but also the skin has an unpleasant feeling such as a feeling of tension and tingling.
<Four-grade evaluation based on the total score>
⊚: Total score is 50 to 60 points ○: Total score is 40 to 49 points △: Total score is 30 to 39 points ×: Total score is less than 30 points

The acyl amino acid salt aqueous solutions prepared in Examples 1 to 3 had good foam spreadability, emulsion stability, and moisturizing feeling during washing.

On the other hand, since the acyl amino acid salt aqueous solution prepared in Comparative Example 1 has a small number of carbon atoms of the hydroxy fatty acid acyl group, it is inferior in foam spreadability and emulsion stability, and the moisturizing feeling during washing is also insufficient. ..

Since the acyl amino acid salt aqueous solution prepared in Comparative Example 2 had a large number of carbonized hydroxy fatty acid acyl groups of 24, it was inferior in ease of foam expansion and emulsion stability.

Since the acyl amino acid salt aqueous solution prepared in Comparative Example 3 does not have a hydroxy group in the fatty acid acyl group, it is inferior in foam spreadability and emulsion stability, and has insufficient moisturizing feeling during washing.

According to the present invention, the hydroxy fatty acid acyl-N- (2-hydroxyethyl) -β-alanine, which is excellent in moisturizing feeling during washing, forms an easily spreadable foam showing good washing comfort, and shows high emulsion stability. Or the salt can be obtained.

Claims (1)

General formula (1):

(In equation (1),

Indicates a hydroxy fatty acid acyl group having 6 to 22 carbon atoms, and M represents a hydrogen atom, an alkali metal, a 1/2 alkaline earth metal, an organic ammonium or an amino acid salt. )
Hydroxy fatty acid acyl-N- (2-hydroxyethyl) -β-alanine represented by, or a salt thereof.