JPS58134197A - Cationic surfactant composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cationic surfactant composition, and more particularly, the present invention relates to a cationic surfactant composition containing an amino acid higher alkyl ester salt or its N-lower alkyl substituted product as one of the active ingredients; This invention relates to a cationic surfactant consisting of an aqueous solution with low and suppressed hydrolyzability.

In recent years, cationic surfactants have come to be widely used for general household use, and have come to occupy a considerable amount in terms of quantity. When using this cationic surfactant, strong alkalinity or strong acidity usually has various disadvantages, so the closer to neutral it is, the easier it is to use, and especially in applications where there is a possibility of contact with the human body, it is recommended to use a surfactant that is close to the isoelectric point of the skin. The pH range of 4 to 6 is preferable.

By the way, amino acid higher alkyl ester salts and their N-lower alkyl substituted products have been known as cationic surfactants with little skin irritation and high safety. However, a common drawback of these ester salts is that
Because it has an ester bond in its structure, it is highly hydrolyzable, so it is often difficult to stably incorporate it into products. In addition, their hydrolyzability is highly pH dependent, and the pH at which hydrolysis is minimal is considerably lower than the pH at which cationic surfactants are generally used. For example, glycine higher alkyl ester hydrochloride is most difficult to hydrolyze at a pH of 1 to 2, but since ordinary cationic surfactants are often used in the pH range of 3 to 8, their combined use is quite limited. I can't escape it.

The present inventors have determined that the pH at which ordinary cationic surfactants are used is
In order to suppress the hydrolysis of amino acid higher alkyl ester salts and their N-lower alkyl substituted salts in a pH range of 3 or higher, and to enable the combined use of both, we have found that the conventionally known cationic When a specific surfactant is selected and used in combination with the above-mentioned ester salt, their hydrolysis is surprisingly significantly suppressed at pH 3 to 4, which is the commonly used pH. The present invention was completed based on this finding.

That is, the present invention provides (A) at least one selected from amino acid higher alkyl ester salts and their N-lower alkyl substituted products; Straight chain aliphatic hydrocarbon group, R/ has 1 to 3 carbon atoms
is an alkyl group, hydroxyalkyl group or benzyl group, and each R' may be the same or different.
is the number of O or l, and X- is a -valent anion) in a weight ratio of (B) to (A) from 1 to 115. The present invention provides a cationic surfactant composition comprising water and a solution.

As the amino acid higher alkyl ester salt and its N-lower alkyl substituted product which is the component (A) of the composition of the present invention, for example, the general formula (ID R50-C-R'-NR2RsR4Y...
・(II)1 (R' in the formula is a divalent group constituting an amino acid, R2,
R3 and R4 are hydrogen atoms or lower alkyl groups, R5 is a higher alkyl group having 8 to 22 carbon atoms, and Y is a monovalent anion. Those having the following structure are preferably used.

This amino acid higher alkyl ester salt or its N-lower alkyl substituted product can be prepared by a commonly used known method, such as drying hydrogen chloride gas or p-toluenesulfonic acid by drying the amino acid or its N-lower alkyl substituted product with a higher alcohol. It can be easily synthesized by dehydration without a solvent or using a solvent such as toluene in the presence of a catalyst. However, in the case of glycine chloride betaine higher alkyl ester, etc., it can be easily produced by producing monochloroacetic acid higher alkyl ester from monochloroacetic acid and a higher alcohol without a solvent or catalyst, and then quaternizing it with trimethylamine or the like. And it can be manufactured at low cost.

In addition, in order to change the type of anion of these ester salts, for example, the p-)luenesulfonate is dissolved in an appropriate amount of alkaline aqueous solution, extracted with a solvent such as hexane, and the resulting hexane extracted layer is An inorganic acid such as hydrochloric acid or an organic acid such as acetic acid or the acidic amino acid 1-pyroglutamic acid may be added, and the corresponding salt can be easily produced by this operation.

Examples of amino acids forming the skeleton of the amino acid higher alkyl ester salts and N-lower alkyl substituted products thereof used in the present invention include glycine, sarcosine, alanine, β-alanine, γ-aminobutyric acid, leucine, isoleucine, aspartic acid, and glutamine Ws. ') Syn, methionine, pro-1-non, serine, threonine, cysteine, cysteine, phenylalanine, ε-aminocaproic acid, etc. Among these, glycine, sarcosine, alanine, β-alanine, γ-aminobutyric acid, glutamic acid , methionine, lysine, etc. are preferably used because they have a relatively simple structure and are easily available.

Furthermore, the amino acid higher alkyl ester salts and their N-lower alkyl substituted salts used in the present invention may be used alone or in combination of two or more, and the type of amino acid and higher alkyl group may be By appropriately selecting the chain length, it is possible to have almost the same performance as existing cationic surfactants. Therefore, these ester salts can be used in most applications where cationic surfactants are traditionally used, and
- By using it as the main component in the surfactant composition,
The composition is highly safe with less skin irritation.

The cationic surfactant used as component (B) of the composition of the present invention has a structure represented by general formula (1) (in which R, R'', m and X- have the same meanings as above) By adding AhX to amino acid higher alkyl ester salts and their N-lower alkyl substituted products, the hydrolysis of these ester salts can be extremely effectively inhibited. However, the cationic interface Among surfactants, those having a dialkyl type or a branched alkyl chain do not have a sufficient hydrolysis inhibiting effect, and among monolinear alkyl type cationic surfactants, those with a straight chain alkyl group having a carbon number of 8 to 22 Particularly excellent are those in the range of .If the number of carbon atoms in the linear alkyl group is less than 8, there is almost no effect on inhibiting hydrolysis, while if it exceeds 22, it becomes difficult to stably incorporate it into the composition. .

On the other hand, in the case of betaine-type amphoteric surfactants, the effect of suppressing the hydrolysis of component (A) is not 1:1, but 4:1, as compared to the cationic surfactant used as component (B) of the present invention. The surfactant of the present invention is (A
) is not suitable because it forms a water-insoluble complex with the components and precipitates.

In the composition of the present invention, the weight ratio of the cationic surfactant as the component (B) to the amino acid higher alkyl pastel salt or its N-lower alkyl substituted product as the component (A) is 1.
If the amount of component (B) exceeds 1 part by weight per 1 part by weight of component (A), the hydrolysis of component (A) will be suppressed; The characteristics of the component are not fully exhibited, and the component (B) is
) When the amount is less than 115 parts by weight per 1 part by weight of the component (A)
Hydrolysis of components is not sufficiently suppressed.

The concentration of the composition of the present invention is not particularly limited, but generally a 0.1 to 10% by weight aqueous solution is suitable. It is also possible to add various other additives that are used in commercial products.

The composition of the present invention is a cationic surfactant composition consisting of an aqueous solution containing as a main component an amino acid higher alkyl ester salt or its N-lower alkyl substituted product, and is highly safe with little skin irritation. , and even in the commonly used pH range, the ester component has low hydrolyzability and has almost the same performance as conventionally used cationic surfactants.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 Glycine stearyl ester hydrochloride 2% by weight cationic surfactant 1 Isopropyl alcohol 5 Water
92 After preparing the above mixed composition containing different types of linear monoalkyl cationic surfactants and adjusting the pH to 3 and 4,
The samples were left in a water bath at 0° C. for 8 hours, and the hydrolysis rate of each ester salt was examined. The results are shown in Table 1.

Table 1 Note that when these mixed compositions were left at room temperature for 6 months, at pH 3, the hydrolysis rate of C+5Ha7N" (C!Ha
) In the system to which sol- was added, the hydrolysis rate was 2% or less.

Glycine/stearyl ester hydrochloride 2% by weight isopropyl alcohol 5 Water
89-93 The above-mentioned mixed composition in which the amount of stearyltrimethylammonium chloride added was varied in the range of 0 to 4% by weight was prepared, the pH was adjusted to 3, and the mixture was left in a water bath at 80° C. for 8 hours to prepare the ester. The hydrolysis rate of each salt was investigated. The results are shown in Table 2.

1 Table 2 Example 3 Glycine stearyl ester hydrochloride 2% by weight stearyltrimethylammonium chloride IN inopropyl alcohol 5 Water
92 #After preparing the above aqueous solution and adjusting the pH to 1.0.2.0.3.0.4.0, it was left in a water bath at 80°C for 8 hours to determine the hydrolysis rate of the ester salt. I investigated each. The results are shown in Table 3. For comparison, the hydrolysis rate of the ester salt at each pH was also investigated for the case without the addition of stearyltrimethylammonium chloride (6), and the results are shown in Table 3. show.

Table 3 Example 4 Stearyltrimethylammonium chloride 11
Isopropyl alcohol 5 #water
92 # The above mixed composition was prepared by changing the type of amino acid higher alkyl ester salt or its N-lower alkyl substituted product, and the pH was adjusted to 3, and then left in a water bath at 80°C for 16 hours to prepare the ester salt. The hydrolysis rate of each was investigated. The results are shown in Table 4.

For comparison, the hydrolysis rate of each ester salt was similarly investigated in the case where stearyltrimethylammonium chloride was not added, and the results are shown in Table 4.

Comparative Example Glycine stearyl ester hydrochloride 2% by weight Surfactant 1 Inpropyl alcohol 5 Water
92 Prepare the above mixed composition containing different types of surfactants, adjust the pH to 3, and then leave it in a 180°C water bath for 8 hours.
The hydrolysis rate of each ester salt was investigated. The results are shown in Table 5 together with the hydrolysis rates when no surfactant was added and when the cationic surfactant of the present invention was added.

Table 5 [- To[・Item 3 Relationship with the case of the person making the amendment Patent applicant Address: 3-7-4 Honjo-chome, Sumida-ku, Tokyo; Agent: 5th floor, 8th floor, Tsuchiya Building, 6-4-5, Ginza, Chuo-ku, Tokyo 104 , Contents of amendment (1) Chemical formula on line 5 in the Surfactant column of Table 5 on page 18 of the specification Chemical formula on line 6

Claims (1)

[Claims] 1(A) Amino acid higher alkyl ester salt and its N-
at least one selected from lower alkyl substituents;
R' is an alkyl group, hydroxyalkyl group, or benzyl group having 1 to 3 carbon atoms, and each R' may be the same or different (, m is a number of 0 or 1, A cationic surfactant represented by
A cationic surfactant composition comprising an aqueous solution containing (B) to (A) in a weight ratio of 1 to 115.