JPH09143134A - Production of amide-ether carboxylate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an amide-ether carboxylate of high purity with reduced content of amide ester as an by-product by the reaction of an amide alcohol with an alkanolamine followed by reaction of the product with a monohalogenoacetic acid. SOLUTION: An amide alcohol of the formula: R<1> CONH-CH2 CH2 O-(CH2 CH2 O)n H (R<1> is a 7-21C alkyl or alkenyl; n is 0-20) is allowed to react with an alkanolamine of the formula: NH(Y)a [(R<2> O) mH]b (Y is H, a 1-3C alkyl; R<3> is a 2-3C alkylene; m is 1-20; a is 0 or 1; b is 1 or 2 where a+b=2) at a temperature higher than the melting point of the amide alcohol but not higher than 100 deg.C for 0.1-5 hours. Then, a monohalogenoacetic acid of the formula: XCH2 COOM (X is a halogen; M is H or an alkali metal) or its salt at 50-100 deg.C under a reduced pressure of 5-200mmHg to give the objective amide-ether carboxylate of the formula: R<1> CONH-CH2 CH2 O-(CH2 CH2 O)n CH2 COOM' (M' is H, a cation).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing an amide ether carboxylate useful as a surfactant, and more particularly to a method for producing a high-purity amide ether carboxylate having a small amount of by-produced amide ester.

[0002]

PRIOR ART AND PROBLEMS TO BE SOLVED BY THE INVENTION General formula
(3) R ¹ CONH-CH ₂ CH ₂ O- (CH ₂ CH ₂ O) _n -CH ₂ COOM '(3) [In the formula, R ¹ is a linear or branched alkyl group having 7 to 21 carbon atoms. Or an alkenyl group, n is a number from 0 to 20 indicating the average number of moles of ethylene oxide added, and M ′ is H or a cation group. ] Since the amido ether carboxylate represented by the formula has good detergency and safety for hair and skin, and has extremely advantageous properties as a detergent, it is frequently contacted with human skin or hair for a long time. Surfactants suitable for use in detergents intended to be used, such as shampoos, shower and bath cleaners, skin care products such as creams, dishwashers and the like.

Such an amide ether carboxylate can be obtained by reacting an amide alcohol with monohalogen acetic acid or a salt thereof. The amide ether carboxylate obtained by such a method is water-insoluble formula (4). ^{_{R 1 CONH-CH 2 CH 2}} O- (CH 2 CH 2 O) n -COR 1 ... (4) wherein, R ¹ and n have the same meanings as defined above. ] The amide ester represented by the formula (1) and the like, which have a large content of insoluble matter, are turbid at room temperature, and even those having a relatively small amount of insoluble matter cause turbidity when they are cold, thus reducing the commercial value.

Accordingly, it is an object of the present invention to provide a method for producing a high-purity amide ether carboxylate containing a small amount of by-produced amide ester.

[0005]

Means for Solving the Problems The inventors of the present invention have made earnest studies in such a situation. As a result, the amide alcohol was first reacted with an alkanolamine, and then the monohalogen acetic acid or a salt thereof was reacted, thereby The inventors have found that the problems can be solved and completed the present invention.

That is, the present invention provides a compound represented by the general formula (1) R ¹ CONH-CH ₂ CH ₂ O- (CH ₂ CH ₂ O) _n H (1) [wherein R ¹ and n have the above-mentioned meanings] Show. To the amide alcohol represented by the general formula (2) XCH ₂ COOM (2) [In the formula, X represents a halogen atom, and M represents H or an alkali metal. ] In producing an amide ether carboxylate represented by the general formula (3) by reacting a monohalogen acetic acid represented by the following or a salt thereof, an amide alcohol represented by the general formula (1) Formula (4) HN (Y) _a [(R ² O) _m H] _b (4) [In the formula, Y is H or an alkyl group having 1 to 3 carbon atoms, and R ² is a direct group having 2 to 3 carbon atoms. A chain or branched alkylene group, m is 1 to 20
, A is 0 or 1, b is 1 or 2, and a + b = 2. ] After reacting 1 to 15 mol% of the alkanolamine represented by the general formula (1) with the amide alcohol represented by the general formula (1), the monohalogen acetic acid represented by the general formula (2) or a salt thereof is reacted. The present invention provides a method for producing an amide ether carboxylate, which is characterized by performing neutralization if necessary.

[0007]

Embodiments of the present invention will be described below in detail.

In the above general formula (1) or (3), R ¹ is a linear or branched alkyl or alkenyl group having 7 to 21 carbon atoms, and n is 0 to 20 which represents the average number of moles of ethylene oxide added. The number of R ¹ is preferably a linear or branched alkyl group having 7 to 21 carbon atoms, and particularly R ¹ is 11 carbon atoms.
Preferred is a straight-chain alkyl of which n is 2-4. In the general formula (3), the cation group represented by M ′ is an alkali metal (eg sodium, potassium etc.), an alkaline earth metal (eg magnesium, calcium etc.), ammonia, an alkanolamine (eg triethanolamine). Etc.), or a cationic group such as a basic amino acid (eg, lysine, arginine, etc.).

The amide alcohol represented by the general formula (1) used as a raw material for carboxymethylation in the present invention is a fatty acid having 8 to 22 carbon atoms, a lower alkyl of the fatty acid (having 1 to 3 carbon atoms in the alkyl group). ) It is obtained by adding ethylene oxide to an alkanolamide obtained by amidation of an ester or a glyceride (oil and fat) of the fatty acid with monoethanolamine. The amidation is preferably carried out with heating using an alkali catalyst such as sodium methylate. Further, the addition reaction of ethylene oxide is carried out by adding alkanolamide as it is or by adding a necessary amount of an alkali catalyst such as sodium hydroxide or potassium hydroxide in order to suppress decomposition of the amide portion, formation of an ester component, coloring, etc. It is preferably carried out at a temperature of not higher than 0 ° C. In addition, when fats and oils are used as a starting material, they contain glycerin or its ethylene oxide adduct, but these can be carboxymethylated as they are, and if necessary, they can be removed by washing with water or the like. Is.

In the present invention, first, the amide alcohol represented by the general formula (1) and the alkanolamine represented by the above general formula (4) are added to the amide alcohol represented by the general formula (1). 1 to 15 mol%, preferably 3 to 10 mol%
Let react. If the amount of alkanolamine is less than 1 mol%, the amount of amide ester by-produced cannot be reduced, and if it exceeds 15 mol%, excess alkanolamine remains and the next carboxymethylation step occurs. In addition to the need for an additional carboxymethylating agent, it is not preferable because it may deteriorate the performance of the resulting amide ether carboxylate or cause coloration over time.

Examples of the alkanolamine represented by the general formula (4) used in the present invention include monoethanolamine, diethanolamine, diglycolamine, triglycolamine, polyglycolamine, N-methylethanolamine, monoisopropanolamine, Examples thereof include diisopropanolamine, and monoethanolamine is particularly preferable.

The reaction temperature between the amide alcohol represented by the general formula (1) and the alkanolamine represented by the general formula (4) is from the melting point of the amide alcohol represented by the general formula (1) to 100 ° C. Is preferable, and 60 to 90 ° C. is more preferable.
The reaction time is preferably 0.1 to 5 hours, 0.5 to 2
Time is more preferred.

Next, a monohalogen acetic acid represented by the general formula (2) or a salt thereof is added to the above reaction solution to react. Examples of the monohalogenacetic acid represented by the general formula (2) or a salt thereof used here include monochloroacetic acid, monobromoacetic acid, or their sodium salts and potassium salts, and monochloroacetic acid or its sodium salt is particularly preferable. This monohalogen acetic acid or a salt thereof may be added in the form of a solid or an aqueous solution, and an amide alcohol represented by the general formula (1) and an alkanolamine represented by the general formula (4) In the reaction liquid of, under heating and reduced pressure, an aqueous solution of a monohalogen acetic acid or a salt thereof represented by the general formula (2), and an aqueous solution of NaOH or KOH is added to carry out the reaction,
It is preferable because a good hue can be obtained. In this case, the aqueous solution concentration of monohalogen acetic acid or its salt is preferably 30 to 90% by weight, and the aqueous solution concentration of NaOH or KOH is preferably 30 to 60% by weight. The reaction temperature at this time is preferably 50 to 100 ° C., and the reaction pressure is preferably 5 to 200 mmHg under reduced pressure.

The reaction product thus obtained is optionally neutralized with a neutralizing agent to obtain an amide ether carboxylate represented by the general formula (3). Examples of the neutralizing agent used here include hydroxides of alkali metals (such as sodium and potassium), hydroxides of alkaline earth metals (such as magnesium and calcium), ammonia, and alkanolamines (such as triethanolamine). ), Or basic amino acids (eg, lysine, arginine, etc.) and the like.

By the method of the present invention as described above, an amide ether carboxylate having a low amide ester content can be obtained, which is obtained by first converting the amide alcohol represented by the general formula (1) into the general formula (4). By reacting the alkanolamine with the alkanolamine, the acyl group on the ester group side of the water-insoluble amide ester present in the amide alcohol represented by the general formula (1) is transferred to the amino group of the alkanolamine. , It is considered that the amide ester is converted to an amide alcohol.

The amide ether carboxylate having a low amide ester content obtained by the production method of the present invention does not cause turbidity even at a low temperature, has excellent low temperature stability, and has a good foaming property. It is useful as a surfactant suitable for shower and bath cleaners, skin care products, tableware cleaners and the like.

[0017]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In the following examples, the amide ester content in amide alcohol was measured by the method of proton NMR. That is, the triplet appearing around δ4.2ppm is a signal characteristic of -CH ₂ OCOR ^{1 of} ester, and δ0.9p
It can be calculated from the integral ratio with the signal of the methyl group near pm. When a signal around δ4.2 ppm cannot be observed by NMR, quantification is performed by HPLC. The content of amide ester in amide ether carboxylate was determined by HPLC.
Quantified by

Production Example 1 214 g of lauric acid methyl ester, monoethanolamine (1.02 equivalents to lauric acid methyl ester) and
A 30% methanol solution of NaOMe (0.2% by weight based on lauric acid methyl ester) was heated at 90 ° C for 7 hours at 50 mmHg to 244 g of an alkanolamide, and 132 g (3 equivalents) of ethylene oxide was added at 90 to 100 ° C. And gauge pressure 0
Introduced at ~ 4 atm for 1.5 hours. This gives formula (5)
376 g of an amide alcohol represented by The amide ester content of this product was 7 mol%.

C ₁₁ H ₂₃ CONHCH ₂ CH ₂ O (CH ₂ CH ₂ O) ₃ H (5) Example 1 376 g (1.0 g of amide alcohol represented by the formula (5) obtained in Production Example 1 Mol) monoethanolamine 4.3 g
(0.07 mol, 7 mol% based on the amide alcohol) was added, and the mixture was heated with stirring at 80 ° C. for 1 hour to carry out the transfer reaction of the amide ester. The amide ester signal disappeared in the NMR measurement after the reaction. In addition, no signal derived from monoethanolamine was observed. Yield 380g.

Amido alcohol thus obtained
376g (1.0mol) is heated to 70-75 ℃, sodium monochloroacetate (SMCA) 117g (1.0mol), solid NaOH 40g
(1.0 mol) was added at the ratio shown in Table 1.

[0021]

[Table 1]

After the addition was completed after 4 hours, the mixture was aged for 1 hour. Next, the reaction temperature was adjusted to 85 ° C., 10 g of water was added, and the mixture was further aged for 1 hour to obtain 498 g of a product containing a compound represented by the formula (6) as a main component. Amide ester content <0.
1% by weight. Hue of 20% aqueous solution (APHA) 300.

C ₁₁ H ₂₃ CONHCH ₂ CH ₂ O (CH ₂ CH ₂ O) ₃ CH ₂ COONa (6) Example 2 Obtained by carrying out rearrangement reaction of amide ester with monoethanolamine in the same manner as in Example 1. Amido alcohol 3
76 g (1.0 mol) was heated to 70 to 75 ° C. and the pressure was reduced to 60 mmHg. While maintaining the reaction temperature and the degree of vacuum in this, water is dehydrated while adding a 40% sodium monochloroacetate aqueous solution.
g (0.6 mol) and a 48% NaOH aqueous solution (53 g, 0.64 mol) were added over 6 hours while keeping the system pH at 8-12. After the addition was completed after 6 hours, the mixture was aged for 1 hour. Next, the reaction temperature is set to 85 ° C., 10 g of water is added, and the mixture is aged for another 1 hour to obtain a product containing a compound represented by the above formula (6) as a main component.
506 g were obtained. Amide ester content <0.1% by weight, APHA
70.

Example 3 123 g of magnesium sulfate heptahydrate (123 g) and water were added to 498 g of a product containing the compound represented by the formula (6) obtained in Example 2 as a main component.
500 g was added and the mixture was stirred at 50 ° C. for 1 hour to obtain 1121 g of a product containing a compound represented by the following formula (7) as a main component. Amide ester content <0.1% by weight, APHA 70.

(C ₁₁ H ₂₃ CONHCH ₂ CH ₂ O (CH ₂ CH ₂ O) ₃ CH ₂ COO) ₂ Mg (7) Comparative Example 1 Amide represented by Formula (5) obtained in Production Example 1 alcohol
376g (1.0mol) was heated to 70-75 ℃, sodium monochloroacetate (SMCA) 117g (1.0mol), solid NaOH 40g
(1.0 mol) was added at the ratio shown in Table 2.

[0026]

[Table 2]

After the addition was completed after 4 hours, aging was carried out for 1 hour. Next, the reaction temperature was adjusted to 85 ° C., 10 g of water was added, and the mixture was aged for 1 hour to obtain 498 g of a product containing the compound represented by the above formula (6) as a main component. Amide ester content
6.1 wt%, APHA 300.

Comparative Example 2 123 g of magnesium sulfate heptahydrate was added to 506 g of the product containing the compound represented by the formula (6) produced in Comparative Example 1 as a main component.
Water (500 g) was added, and the mixture was stirred at 50 ° C. for 1 hour to obtain 1129 g of a product containing the compound represented by the above formula (7) as a main component. Amide ester content 2.7 wt% (5.5 wt% per dry solids), APHA 300.

The foaming amount test and low temperature stability test of the products obtained in Examples 1 to 3 and Comparative Examples 1 and 2 were conducted by the following methods. Table 3 shows the results. <Foaming amount test> Prepare an aqueous solution such that the amide ether carboxylate pure content is 5% by weight, and 100 ml of this solution
Pour (liquid temperature 40 ℃) into a graduated cylinder. Then, a stirring blade was installed in the above solution, and the volume (ml) of the foam generated 30 seconds after the start of stirring was measured and defined as the foaming amount. From this foaming amount, the foaming amount was evaluated according to the following criteria. ○: Foam volume of 200 ml or more △: Foam volume of 180 ml or more and less than 200 ml ×: Foam volume of less than 180 ml <Low temperature stability test> Aqueous solution with dry solid content of 20% by weight -5
It was stored at 7 ° C for 7 days, and the low temperature stability was judged by the presence of turbidity. ◯: Transparent even at −5 ° C./7 days Δ: Transparent at room temperature, but turbid at −5 ° C./7 days ×: Turbid at both room temperature and −5 ° C./7 days

[0030]

[Table 3]

Claims (5)

[Claims] 1. A compound represented by the general formula (1) R ¹ CONH-CH ₂ CH ₂ O- (CH ₂ CH ₂ O) _n H (1) [wherein R ¹ is a straight chain or branched chain having 7 to 21 carbon atoms] Is an alkyl group or an alkenyl group, and n is a number from 0 to 20 indicating the average number of moles of ethylene oxide added. To the amide alcohol represented by the general formula (2) XCH ₂ COOM (2) [In the formula, X represents a halogen atom, and M represents H or an alkali metal. ] By reacting a monohalogen acetic acid or a salt thereof represented by the general formula (3) R ¹ CONH-CH ₂ CH ₂ O- (CH ₂ CH ₂ O) _n -CH ₂ COOM '... (3) In the above, R ¹ and n have the above-mentioned meanings, and M ′ represents H or a cation group. ] When producing an amide ether carboxylate represented by the general formula (1) in the amide alcohol, the general formula (4) HN (Y) _a [(R ² O) _m H] _b ... ( 4) [In the formula, Y is H or an alkyl group having 1 to 3 carbon atoms, R ² is a linear or branched alkylene group having 2 to 3 carbon atoms, and m is 1 to 20.
, A is 0 or 1, b is 1 or 2, and a + b = 2. ] After reacting 1 to 15 mol% of the alkanolamine represented by the general formula (1) with the amide alcohol represented by the general formula (1), the monohalogen acetic acid represented by the general formula (2) or a salt thereof is reacted. And, if necessary, the following neutralization. A method for producing an amide ether carboxylate. 2. The reaction between the amide alcohol represented by the general formula (1) and the alkanolamine represented by the general formula (4) is performed at a temperature not lower than the melting point of the amide alcohol represented by the general formula (1).
The method according to claim 1, which is carried out at a temperature of 100 ° C. or lower for 0.1 to 5 hours. 3. The method according to claim 1, wherein R is a linear or branched alkyl group having 7 to 21 carbon atoms. 4. The amide alcohol represented by the general formula (1) is a fatty acid having 8 to 22 carbon atoms, a lower alkyl (1 to 3 carbon atoms of an alkyl group) ester of the fatty acid, or a glyceride (oil and fat) of the fatty acid. The method according to any one of claims 1 to 3, which is obtained by adding ethylene oxide at 120 ° C or lower to an alkanolamide obtained by the amidation of monoethanolamine with. 5. After reacting an amide alcohol represented by the general formula (1) with an alkanolamine represented by the general formula (4), the reaction mixture is heated under reduced pressure to give the general formula
An aqueous solution of monohalogen acetic acid or a salt thereof represented by (2),
And the reaction is carried out by dropping NaOH or KOH aqueous solution.
5. The manufacturing method according to any one of items 4 to 4.