JP2013199438A - Method for producing fatty acid alkanolamide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for conveniently producing a fatty acid alkanolamide, with which neither a thickening property nor a foam-increasing property is damaged and an excellent appearance without turbidity is brought about when mixed with an anionic surfactant in a water-based medium.SOLUTION: In a method for producing a fatty acid alkanolamide including a step to make a fatty acid ester and an alkanolamine react with each other, when an amount by mole of a fatty acid residue in the fatty acid ester is set to be X and an amount by mole of the alkanolamine is set to be Y, inequality (1) is satisfied, and when a temperature at the moment with a reaction conversion rate of the alkanolamine being 0.05 is represented by T(°C) and the highest temperature in the range of the reaction conversion rate of 0.6 to 0.8 is represented by T(°C), inequalities (2) to (4) are satisfied, 0.8≤X/Y≤1.2 (1), 70≤T≤100 (2), -5≤T-T≤30 (3), and T≤120 (4).

Description

  The present invention relates to a method for producing a fatty acid alkanolamide.

Fatty acid alkanolamides are used as water-based thickeners and foam thickeners mainly in fields such as detergents (Non-Patent Document 1). Specifically, fatty acid alkanolamide has a high utility value as an auxiliary agent because it has an effect of increasing viscosity and foaming when mixed with an anionic surfactant in an aqueous system. This detergent is used in a wide range of fields including products such as kitchen detergents and cosmetics represented by shampoos.
Examples of the method for producing a fatty acid alkanolamide include a method of reacting a fatty acid ester with an alkanolamine (Patent Documents 1 and 2), a method of reacting a fatty acid with an alkanolamine (Patent Document 3), and the like.

Patent Document 1 discloses a method for producing a fatty acid alkanolamide by reacting a cold fatty acid alkyl ester with a heated alkanolamine and an alkali catalyst. However, it has been pointed out that an aqueous liquid product containing a fatty acid alkanolamide obtained by this method is turbid and has a poor appearance.
As an improvement of the production method disclosed in Patent Document 1, Patent Document 2 discloses a method for producing a fatty acid alkanolamide from an alkanolamine and a fatty acid ester using a specific amount of catalyst. However, when the fatty acid alkanolamide obtained by this method is used, the appearance of the aqueous liquid product can be expected to be improved, but it has not been fully satisfactory.
In Patent Document 3, after reacting fatty acid with an alkanolamine having an equivalent amount or less as the first step reaction, reacting with the alkanolamine with an equivalent amount or more in the second step reaction together with the reaction amount in the first step. A manufacturing method characterized by the above is disclosed. The fatty acid alkanolamide obtained by this method has a problem of coloring over time.

  In addition, the fatty acid alkanolamide obtained by the production methods of Patent Documents 1 to 3 is less turbid or less thickened or foamed when mixed with an anionic surfactant in an aqueous system. There was a problem that sometimes. Therefore, this problem hinders the use of fatty acid alkanolamides in a wide range of fields.

Journal of the American College of Toxiology, 1996, 15, 527-542.

US Pat. No. 2,844,609 JP-A-9-143133 JP-A-9-157234

  An object of the present invention is to provide a method for easily producing a fatty acid alkanolamide that has a good appearance without turbidity without impairing thickening and foaming properties when mixed with an anionic surfactant in an aqueous system. It is.

As a result of intensive studies, the present inventors have obtained the knowledge that the above problem can be solved by performing specific control of the reaction temperature in the reaction of fatty acid ester and alkanolamine, and have reached the present invention.
The method for producing a fatty acid alkanolamide of the present invention is a method for producing a fatty acid alkanolamide comprising a step of reacting a fatty acid ester and an alkanolamine, wherein the number of moles of fatty acid residues in the fatty acid ester is X, When the number of moles is Y, the following formula (1) is satisfied, the temperature when the reaction conversion rate of the alkanolamine is 0.05 is T ₁ (° C.), and the reaction conversion rate is 0.6 to When the maximum temperature in the range of 0.8 is T ₂ (° C.), the following mathematical formulas (2) to (4) are satisfied.
0.8 ≦ X / Y ≦ 1.2 (1)
70 ≦ T ₁ ≦ 100 (2)
−5 ≦ T ₂ −T ₁ ≦ 30 (3)
T ₂ ≦ 120 (4)

It is preferable that the production method of the present invention further satisfies at least one requirement selected from the following (A) to (E).
(A) The said process is performed in presence of a basic catalyst.
(B) The alkanolamine is a secondary amine.
(C) The fatty acid ester is a fatty acid ester represented by the following general formula (1) and / or general formula (2), and the alkanolamine is an alkanolamine represented by the following general formula (3).

(However, R ¹ , R ² and R ³ are each an alkyl group having 1 to 21 carbon atoms, an alkenyl group having 3 to 21 carbon atoms, a hydroxyalkyl group having 1 to 21 carbon atoms, or a group having 3 to 21 carbon atoms. It is a hydroxyalkenyl group and may be different from each other or the same.

(However, R ⁴ is an alkyl group having 1 to 21 carbon atoms, an alkenyl group having 3 to 21 carbon atoms, a hydroxyalkyl group having 1 to 21 carbon atoms, or a hydroxyalkenyl group having 3 to 21 carbon atoms. R ⁵ is an alkyl group having 1 to 6 carbon atoms.)

(However, R ⁶ and R ⁷ are each a hydrocarbon group having 1 to 6 carbon atoms, and may be different or the same.)
(D) is 75 ≦ _{T 1} ≦ 85.
(E) 5 ≦ T ₂ −T ₁ ≦ 15.
The surfactant composition of the present invention contains a fatty acid alkanolamide obtained by the above production method and an anionic surfactant.

In the method for producing a fatty acid alkanolamide according to the present invention, a fatty acid alkanolamide having a good appearance without turbidity is easily produced without impairing the viscosity or foaming property when mixed with an anionic surfactant in an aqueous system. be able to.
Since the surfactant composition of the present invention contains the fatty acid alkanolamide obtained by the above-described production method, the aqueous system has a good appearance without turbidity without impairing the thickening and foaming properties.

  The method for producing a fatty acid alkanolamide of the present invention includes a step of reacting a fatty acid ester and an alkanolamine.

(Reaction raw materials)
The fatty acid ester is not particularly limited as long as it is an ester of fatty acid and alcohol.
Examples of such fatty acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, palmiolic acid, oleic acid, Linoleic acid, linolenic acid, nonadecanoic acid, behenic acid, erucic acid, 12-hydroxystearic acid, ricinoleic acid, ricinoleic acid, coconut oil fatty acid, cottonseed oil fatty acid, corn oil fatty acid, palm kernel oil fatty acid, soybean oil fatty acid, sweet potato Examples include fatty acids derived from vegetable oils or animal oils such as oil fatty acids, castor oil fatty acids, olive oil fatty acids, whale oil fatty acids and beef tallow fatty acids, and may be hydrogenated. These fatty acids may be used alone or in combination of two or more.

Moreover, there is no limitation in particular as such alcohol, The structure may be linear or branched, and any of polyhydric alcohols, such as monohydric alcohol, dihydric alcohol, and trihydric alcohol, may be sufficient. The carbon number of the alcohol is not particularly limited, but is preferably 1 to 6, more preferably 1 to 4, and particularly preferably 1 to 3.
Examples of the alcohol include monohydric alcohols such as methanol, ethanol, propanol, isopropanol, butanol, and hexanol; dihydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, and butylene glycol; glycerin and trimethylol. Examples include trihydric alcohols such as propane; tetrahydric alcohols such as pentaerythritol; hexavalent alcohols such as sorbitol. These alcohols may be used alone or in combination of two or more. Among these alcohols, methanol and glycerin are preferable because of their general availability.
The fatty acid ester is preferably a fatty acid ester represented by the following general formula (1) and / or general formula (2).

(However, R ¹ , R ² and R ³ are each an alkyl group having 1 to 21 carbon atoms, an alkenyl group having 3 to 21 carbon atoms, a hydroxyalkyl group having 1 to 21 carbon atoms, or a group having 3 to 21 carbon atoms. It is a hydroxyalkenyl group and may be different from each other or the same.

(However, R ⁴ is an alkyl group having 1 to 21 carbon atoms, an alkenyl group having 3 to 21 carbon atoms, a hydroxyalkyl group having 1 to 21 carbon atoms, or a hydroxyalkenyl group having 3 to 21 carbon atoms. R ⁵ is an alkyl group having 1 to 6 carbon atoms.)
The number of carbon atoms of the alkyl group or hydroxyalkyl group as R ¹ , R ² , R ³ and R ⁴ is preferably 1-19, more preferably 3-17, and particularly preferably 7-15. If the alkyl group or the hydroxyalkyl group has more than 21 carbon atoms, the resulting fatty acid alkanolamide becomes more hydrophobic and may become insoluble in water, resulting in turbidity in an aqueous system.

The carbon number of the alkenyl group or hydroxyalkenyl group as R ¹ , R ² , R ³ and R ⁴ is preferably 3-17, more preferably 5-15. If the alkenyl group or the hydroxyalkenyl group has more than 21 carbon atoms, the resulting fatty acid alkanolamide is highly hydrophobic and may become insoluble in water, resulting in turbidity in an aqueous system.
The carbon number of the alkyl group as R ⁵ is preferably 1-5, more preferably 1-4, particularly preferably 1-3.

It is preferable that the fatty acid ester is coconut oil or palm kernel oil because it is general and highly versatile.
The alkanolamine may be either a monoalkanolamine or a dialkanolamine, but the alkanolamine is preferably a dialkanolamine because the resulting fatty acid alkanolamide has high water solubility. Examples of dialkanolamines include diethanolamine, di-n-propanolamine, diisopropanolamine, and dibutanolamine. These dialkanolamines may be used alone or in combination of two or more. When the dialkanolamine is diethanolamine, the resulting fatty acid alkanolamide is excellent in thickening and foaming properties when mixed with an anionic surfactant in an aqueous system.
As the alkanolamine, for example, a dialkanolamine represented by the following general formula (3) is preferable.

(However, R ⁶ and R ⁷ are hydrocarbon groups having 1 to 6 carbon atoms, and may be different from each other or the same.
R ⁶ and R ⁷ may have any structure such as a straight chain structure, a branched chain structure, or a cyclic structure, and may include a double bond or a triple bond.
The number of carbon atoms of the hydrocarbon group as R ⁶ and R ⁷ is preferably 2 to 4. Specifically, R ⁶ and R ⁷ are preferably an ethylene group, a propylene group, or a butylene group, and more preferably an ethylene group.

(Reaction process)
In the production method of the present invention, a step of reacting a fatty acid ester and an alkanolamine to obtain a fatty acid alkanolamide (hereinafter sometimes referred to as a reaction step) is performed. When the number of moles is X and the number of moles of alkanolamine is Y, the following formula (1) is satisfied.
0.8 ≦ X / Y ≦ 1.2 (1)

Here, the fatty acid residue in the fatty acid ester means the remaining group obtained by removing the hydroxyl group from the carboxyl group in the fatty acid. For example, when the fatty acid is expressed as RCOOH, the fatty acid residue is expressed as RCO. It is a group. Therefore, the fatty acid residue in the general formula (1) is a group expressed as R ¹ CO, a group expressed as R ² CO, and a group expressed as R ³ CO. Further, the fatty acid residue in the general formula (2) is a group expressed as R ⁴ CO.
Satisfying the formula (1) in the reaction step simply means that the fatty acid ester and the alkanolamine are reacted almost stoichiometrically. Therefore, it is suppressed that unreacted raw materials remain after the reaction step.

Formula (1) is preferably 0.8 ≦ X / Y ≦ 1.1, more preferably 0.85 ≦ X / Y ≦ 1.0, and particularly preferably 0.9 ≦ X / Y ≦ 0.98. is there.
When X / Y is less than 0.8, a large amount of unreacted alkanolamine remains after the reaction step, and when the resulting fatty acid alkanolamide is mixed with an anionic surfactant in an aqueous system, viscosity increase and foaming property are increased. It may be damaged. On the other hand, when X / Y exceeds 1.2, a large amount of unreacted fatty acid ester remains after the reaction step, and turbidity in an aqueous system may occur.

In the reaction step, the reaction is controlled based on the reaction conversion rate (C) and reaction temperature (T) of alkanolamine.
The reaction conversion rate C of alkanolamine means the proportion of alkanolamine consumed by the reaction among the alkanolamines charged in the reaction vessel. In the present invention, the reaction conversion rate C of the alkanolamine at a certain time t during the reaction is expressed as follows: the amine value of the reaction mixture immediately after the fatty acid ester and the alkanolamine are charged into the reaction vessel is A (unit: KOHmg / g) When the amine value of the reaction mixture at a certain time t is B (unit: KOHmg / g), it is defined by the following calculation formula (i).
Reaction conversion rate of alkanolamine C = (AB) / A (i)

In the reaction step, the temperature when the reaction conversion rate of alkanolamine is 0.05 (C = 0.05) is T ₁ (° C.), and the reaction conversion rate is the highest temperature in the range of 0.6 to 0.8. Is T ₂ (° C.), the following mathematical formulas (2) to (4) are satisfied.
70 ≦ T ₁ ≦ 100 (2)
−5 ≦ T ₂ −T ₁ ≦ 30 (3)
T ₂ ≦ 120 (4)

The numerical formula (2) is preferably 70 ≦ T ₁ ≦ 90, more preferably 75 ≦ T ₁ ≦ 85.
When T ₁ is less than 70, the reaction rate is extremely slow, which is not practical. On the other hand, when T ₁ is more than 100, turbidity may occur when the resulting fatty acid alkanolamide is mixed with an anionic surfactant in an aqueous system.

Formula (3) is preferably 0 ≦ T ₂ −T ₁ ≦ 20, more preferably 3 ≦ T ₂ −T ₁ ≦ 15, and particularly preferably 5 ≦ T ₂ −T ₁ ≦ 10.
When T ₂ -T ₁ is less than −5, when the resulting fatty acid alkanolamide is mixed with an anionic surfactant in an aqueous system, viscosity increase and foam increase properties are impaired. On the other hand, if T ₂ -T ₁ is more than 30, turbidity may occur when the resulting fatty acid alkanolamide is mixed with an anionic surfactant in an aqueous system.

Formula (4) is preferably T ₂ ≦ 110, more preferably T ₂ ≦ 100, and particularly preferably T ₂ ≦ 95.
If T ₂ is 120 greater than can occur turbidity fatty acid alkanolamides obtained when mixed with anionic surfactant in an aqueous system.

In general, in the reaction of a fatty acid ester and an alkanolamine, when the reaction temperature is gradually increased after charging, the reaction rapidly proceeds with a sudden exotherm from a certain point, but thereafter the exotherm gradually decreases and the temperature becomes stable. The resulting fatty acid alkanolamide was not preferred when mixed with an anionic surfactant in an aqueous system, because the viscosity and foaming properties were reduced and the appearance was turbid. However, in the production method of the present invention, the reaction temperature is controlled so as to satisfy the mathematical formulas (2) to (4), so that the reaction process can be avoided at an extremely high temperature. The reaction step is performed under mild conditions. By defining the reaction temperature in this way, when mixed with an anionic surfactant in an aqueous system, it does not impair the thickening and foaming properties, it becomes a good appearance without turbidity, and the obtained surfactant composition Product value can be increased.
There is no particular limitation on the control of the reaction temperature that satisfies the mathematical formulas (2) to (4), and the control may be performed by ordinary means such as manual operation or PID control. In order to lower the reaction temperature, it may be performed by means such as cooling with cooling water or a refrigerant or air cooling. On the other hand, when raising the reaction temperature, it may be performed by means such as heating with steam or a heating medium.

If the reaction conversion of the alkanolamine has a T ₃ and the reaction temperature until the reaction becomes 0.8 or more is completed, it is preferably carried out in the range of 70 ≦ T ₃ ≦ 100.
The reaction step may be performed in the presence of a basic catalyst. The basic catalyst is not particularly limited, and examples thereof include alkali metal hydroxides such as potassium hydroxide, lithium hydroxide and sodium hydroxide; alkalis such as sodium methoxide, potassium methoxide, lithium methoxide and sodium ethoxide. Metal alkoxides; alkaline earth metal hydroxides such as calcium hydroxide and magnesium hydroxide; alkaline earth metal alkoxides such as calcium dimethoxide and the like. These catalysts may be used alone or in combination of two or more.

The amount of the basic catalyst used is not particularly limited, but is preferably 0.05 to 5% by weight of alkanolamine, more preferably 0.3 to 3% by weight, and most preferably 0.5 to 5%. 2% by weight. When the amount of the basic catalyst used is less than 0.05% by weight, the reaction rate may become extremely slow or the reaction may not proceed. On the other hand, when the amount of the basic catalyst used exceeds 5% by weight, the fatty acid alkanolamide may be easily colored.
Although there is no limitation in particular about the addition time of a basic catalyst, it is preferable to carry out with the addition of fatty acid ester and alkanolamine.

When the reaction step using the basic catalyst is completed, the basic catalyst may or may not be removed. Examples of the removal of the basic catalyst include a method of solid-liquid separation after adsorbing the basic catalyst to an adsorbent. Examples of the adsorbent include silicates such as aluminum silicate and magnesium silicate, activated clay, acid clay, silica gel, ion exchange resin and the like. Examples of commercially available adsorbents include KYOWARD 600, 700 (manufactured by Kyowa Chemical Co., Ltd.), Mizuka Life P-1, P-1S, P-1G, F-1G (manufactured by Mizusawa Chemical Co., Ltd.), Tomita-AD600, 700. Silicates (Tomita Pharmaceutical Co., Ltd.), etc .; Amberlist (Rohm and Haas), Amberlite (Rohm and Haas), Diaion (Mitsubishi Chemical), Dowex (Dow Chemical) And the like, and the like. These adsorbents may be used alone or in combination of two or more.
The amount of the adsorbent used is, for example, preferably 100 to 5000 parts by weight, more preferably 300 to 3000 parts by weight with respect to 100 parts by weight of the basic catalyst.

The conditions for removing the basic catalyst are not particularly limited. For example, the adsorbent is stirred and mixed at a temperature of 20 to 100 ° C. for 5 to 120 minutes under any one of reduced pressure, normal pressure, and increased pressure conditions. , A method of separating the adsorbent adsorbed with the basic catalyst by the above-mentioned solid-liquid separation method, or a column or the like is previously filled with the adsorbent, and the reaction mixture is allowed to pass at a temperature of 20 ° C. to 100 ° C. For example, a method of removing the basic catalyst by adsorbing. At this time, if necessary, 1 to 20 parts by weight of a water-soluble solvent such as water or lower alcohol represented by ethanol may be added to 100 parts by weight of the reaction mixture.
The reaction step may be performed without a solvent or in a solvent. When a solvent is used, the solvent is not particularly limited as long as it does not react with fatty acid esters and alkanolamines. For example, hydrocarbons such as toluene, xylene, hexane and cyclohexane; ethers such as diethyl ether and tetrahydrofuran; dimethyl sulfoxide , N-methylpyrrolidone and the like. These solvents may be used alone or in combination of two or more.

The solvent may be added in advance to the fatty acid ester and alkanolamine, or the solvent may be added during the reaction step. Further, it is desirable to remove the solvent by distillation or the like after the reaction step.
In the reaction step, alcohol derived from the fatty acid ester as a raw material is generated as a by-product. The alcohol may or may not be removed at the end of the reaction process. The alcohol removal method is not particularly limited, and examples thereof include distillation under reduced pressure and washing with water.

The fatty acid alkanolamide thus obtained is used as an aqueous thickener or foaming agent mainly in the field of cleaning agents and the like.
Fatty acid alkanolamide is highly useful as an auxiliary agent because it has an effect of increasing viscosity and foaming when mixed with an anionic surfactant in an aqueous system. This detergent includes laundry detergents, kitchen detergents, toilet detergents, as well as shampoos, rinses, body soaps, hand soaps, facial cleansing foams, cosmetics, toothpastes, mouthwashes, It is used in a wide range of fields centering on products that require thickening and foaming.

(Surfactant composition)
The surfactant composition of the present invention is a composition comprising the fatty acid alkanolamide obtained by the above production method and an anionic surfactant.
The anionic surfactant is not particularly limited. For example, fatty acid salts such as sodium oleate, potassium palmitate, triethanolamine oleate; sodium lauryl sulfate, ammonium lauryl sulfate, sodium stearyl sulfate, sodium cetyl sulfate, etc. Alkyl sulfate salts; polyoxyalkylene alkyl ether acetates such as sodium polyoxyethylene tridecyl ether acetate and sodium polyoxyethylene alkyl ether acetates; alkylbenzene sulfonates such as sodium dodecylbenzene sulfonate; polyoxyalkylene alkyl ether sulfates Salt: Stearoyl methyl taurine Na, lauroyl methyl taurine Na, myristoyl methyl taurine Na, palmitoyl methyl taurine Na, etc. Higher fatty acid amide sulfonates; N-acyl sarcosine salts such as sodium lauroyl sarcosine; alkyl phosphates such as sodium monolauryl phosphate; polyoxyethylene oleyl ether sodium phosphate, polyoxyethylene stearyl ether sodium phosphate Oxyalkylene alkyl ether phosphate ester salts; long-chain sulfosuccinates such as sodium di-2-ethylhexylsulfosuccinate and sodium dioctylsulfosuccinate, monosodium N-lauroylglutamate monosodium, and disodium N-stearoyl-L-glutamate Chain N-acyl glutamate; polyacrylic acid, polymethacrylic acid, polymaleic acid, polymaleic anhydride, copolymer of maleic acid and isobutylene, maleic anhydride Copolymer of isobutylene, copolymer of maleic acid and diisobutylene, copolymer of maleic anhydride and diisobutylene, copolymer of acrylic acid and itaconic acid, copolymer of methacrylic acid and itaconic acid Polymer, Copolymer of maleic acid and styrene, Copolymer of maleic anhydride and styrene, Copolymer of acrylic acid and methacrylic acid, Copolymer of acrylic acid and methyl acrylate, Acrylic Copolymers of acid and vinyl acetate, copolymers of acrylic acid and maleic acid, alkali metal salts (lithium salts, sodium salts, potassium salts, etc.) of acrylic acid and maleic anhydride copolymers, alkaline earth Metal salts (magnesium salts, calcium salts, etc.), polycarboxylates such as ammonium salts and amine salts; naphthalene sulfonic acid, alkyl naphthalene Formalin condensate of phonic acid, naphthalene sulfonic acid, formalin condensate of alkyl naphthalene sulfonic acid, and alkali metal salts thereof (lithium salt, sodium salt, potassium salt, etc.), alkaline earth metal salts (magnesium salt, calcium salt) ), Naphthalene sulfonates such as ammonium salts and amine salts; melamine sulfonic acid, alkyl melamine sulfonic acid, formalin condensate of melamine sulfonic acid, formalin condensate of alkyl melamine sulfonic acid, and alkali metal salts thereof (lithium) Salts, sodium salts, potassium salts, etc.), alkaline earth metal salts (magnesium salts, calcium salts, etc.), melamine sulfonates such as ammonium salts and amine salts, etc .; lignin sulfonic acid, and alkali metal salts thereof (lithium) Salt, natri Salts, potassium salts, etc.), alkaline earth metal salts (magnesium salts, calcium salts, etc.), lignin sulfonates such as ammonium salts and amine salts, and the like, or one or more of them may be used in combination. .

The weight ratio (AA / AS) of the fatty acid alkanolamide (hereinafter referred to as AA) and the anionic surfactant (hereinafter referred to as AS) is not particularly limited, but is preferably 1/99 to 99/1, more preferably 10/90. ˜90 / 10, particularly preferably 50/50 to 85/15.
The surfactant composition of the present invention contains a fatty acid alkanolamide and an anionic surfactant as essential components. However, since the surfactant composition is often used in water-based products such as shampoos, it further contains water. You may go out.

The water may be any of distilled water, ion exchange water, tap water, and well water. Hereinafter, the fatty acid alkanolamide and the anionic surfactant may be referred to as a surfactant component.
When the surfactant composition contains water, the concentration of the surfactant component is not particularly limited, but is preferably 5 to 60% by weight, more preferably 10 to 40% by weight, and particularly preferably 15 to 30% by weight. It is.
The surfactant composition may contain components other than water. Components other than water are not particularly limited. For example, cationic surfactants, nonionic surfactants, amphoteric surfactants, moisturizers, UV absorbers, alcohols, chelating agents, pH adjusters, and pearlizing agents. Agents, antioxidants, preservatives, antidandruff agents, dyes, fragrances, silicone derivatives and the like.

  Examples of the present invention and comparative examples will be specifically described below. The present invention is not limited to these examples.

(Amine number of the reaction mixture)
The reaction mixture amine value is measured and calculated based on the Quasi-drug Raw Material Standard (2006 version).

(Reaction conversion rate of alkanolamine)
The reaction conversion rate C of alkanolamine at time t of the reaction step is calculated from the amine value of the reaction mixture by the following calculation formula.
Reaction conversion rate of alkanolamine C = (AB) / A
A: Amine value of reaction mixture immediately after mixing fatty acid ester and alkanolamine into reaction vessel B: Amine value of reaction mixture at time t

(Physical properties of alkanolamide)
An alkanolamide (AA) and an anionic surfactant (AS) are blended at AA / AS = 12/3 (weight ratio), so that the concentration of the surfactant component (AA + AS) is 15% by weight. Exchanged water was added to prepare a surfactant composition. The anionic surfactant used here is sodium polyoxyethylene alkyl ether sulfate (AES), the average number of added moles of oxyethylene is 3, and the alkyl group has 12 or 13 carbon atoms. there were. The concentration of the surfactant component in the surfactant composition is calculated by the following calculation formula.
Surfactant component concentration (% by weight) =
100 × {(AA (g) + AS (g)) / (AA (g) + AS (g) + ion-exchanged water (g))}
The appearance of the surfactant composition was evaluated according to the following evaluation criteria.

[Evaluation criteria for appearance]
○: Not turbid and transparent Δ: Slightly turbid ×: Clear turbidity Next, the viscosity of the surfactant composition was measured using a B-type viscometer (temperature 20 ° C., rotor No. 2, rotation speed 30 rpm). And measured. If the viscosity is 500 mPa · s or more, it is acceptable.

The surfactant composition was further diluted with ion-exchanged water to prepare a surfactant composition having a surfactant component of 0.1% by weight. The foamability of the surfactant composition obtained by dilution was evaluated by measuring the immediately foaming degree (mm) by the Ross Miles method (temperature 25 ° C.). A degree of foaming of 200 mm or more is acceptable.
In the overall judgment of physical properties, a product whose appearance is evaluated as “good” and the viscosity and foaming degree are acceptable is determined as “good” (◯), and otherwise, it is determined as “failed” (x).

[Example 1]
In a 500 ml four-necked flask equipped with a stirrer, a thermometer, a nitrogen introduction tube and a dropping funnel, 236 g of refined coconut oil (saponification number 258; 1.085 mol of fatty acid residue) and 120 g of diethanolamine (molecular weight 105. 14; 1.141 mol) and 1.8 g of potassium hydroxide as a catalyst were added, and the reaction was started at 80 ° C. with stirring under a nitrogen stream.
The reaction conversion of diethanolamine was calculated from the amine number of the reaction mixture, the reaction conversion rate of the temperature T ₁ of the case of 0.05 was 80 ° C.. Then, by controlling the temperature, so that the reaction conversion rate is the highest temperature _{T 2} in the range of 0.6 to 0.8 was 90 ° C.. Thereafter, when the reaction conversion rate was 0.8 or more, the temperature was controlled to be 80 ° C. to obtain coconut oil fatty acid diethanolamide.
The physical properties of the obtained coconut oil fatty acid diethanolamide were evaluated according to the above evaluation methods, and the results are shown in Table 1.

[Examples 2 to 4]
In Examples 2 to 4, the reaction was performed in the same manner as in Example 1 except that the amounts of refined coconut oil and diethanolamine added in Example 1 and T ₁ and T ₂ were changed to those shown in Table 1, respectively. And coconut oil fatty acid diethanolamide were obtained. The physical properties of the obtained coconut oil fatty acid diethanolamide were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Example 5
In Example 1, 216 g of coconut oil fatty acid methyl (0.981 mol of fatty acid residue) was used instead of 236 g of refined coconut oil, and the amount of diethanolamine was changed to 105.14 g (1.000 mol). In the same manner as in Example 1, raw materials were added to the four-necked flask, and the reaction was started at 75 ° C.
The reaction conversion of diethanolamine the temperature _{T 1} of the case of 0.05 was 75 ° C.. Then, by controlling the temperature, so that the reaction conversion rate is the highest temperature _{T 2} in the range of 0.6 to 0.8 was 85 ° C.. Thereafter, when the reaction conversion rate was 0.8 or more, the temperature was controlled to be 80 ° C. to obtain coconut oil fatty acid diethanolamide. The physical properties of the obtained coconut oil fatty acid diethanolamide were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Example 6
In Example 1, 236 g of palm kernel oil (saponification number 258; number of moles of fatty acid residue: 1.085 mol) was used instead of 236 g of refined coconut oil, and 120 g of diethanolamine (molecular weight 105.14; 1.141 mol) was used. Except for changing, the raw material was added to the four-necked flask in the same manner as in Example 1, and the reaction was started at 90 ° C.
The temperature T ₁ when the reaction conversion rate of diethanolamine was 0.05 was 90 ° C. Then, by controlling the temperature, so that the reaction conversion rate is the highest temperature _{T 2} in the range of 0.6 to 0.8 was 95 ° C.. Thereafter, at a reaction conversion rate of 0.8 or higher, the temperature was controlled to be 90 ° C. to obtain palm kernel oil fatty acid diethanolamide. The physical properties of the obtained palm kernel oil fatty acid diethanolamide were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[Comparative Examples 1-3]
In Comparative Examples 1 to 3, the reaction was carried out in the same manner as in Example 1 except that T ₁ and T ₂ were changed to the temperatures shown in Table 1 in Example 1, and coconut oil fatty acid diethanolamide was obtained. The physical properties of the obtained coconut oil fatty acid diethanolamide were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[Comparative Example 4]
In Comparative Example 4, the reaction was carried out in the same manner as in Example 2 except that T ₁ and T ₂ were changed to the temperatures shown in Table 1 in Example 2 to obtain coconut oil fatty acid diethanolamide, respectively. The physical properties of the obtained coconut oil fatty acid diethanolamide were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[Comparative Example 5]
In Comparative Example 5, the raw materials were charged into a four-necked flask in the same manner as in Example 1, and the reaction was started at 50 ° C. The reaction conversion rate of diethanolamine 5 hours after the start of the reaction was 0.03. Thereafter, the reaction was continued for 2 hours, but the reaction was canceled because there was no change in the reaction conversion rate.

In Examples 1 and 2, it can be seen that a fatty acid alkanolamide having a good appearance without turbidity can be easily produced without impairing the thickening and foaming properties when mixed with an anionic surfactant in an aqueous system.
On the other hand, in Comparative Examples 1, 2, and 4, turbidity occurred when mixed with an anionic surfactant in an aqueous system. In Comparative Example 3, foaming property and viscosity were low. In Comparative Example 5, the reaction temperature was too low and the reaction process did not proceed.

Claims (7)

A method for producing a fatty acid alkanolamide comprising a step of reacting a fatty acid ester and an alkanolamine,
When the number of moles of fatty acid residues in the fatty acid ester is X and the number of moles of the alkanolamine is Y, the following mathematical formula (1) is satisfied:
When the reaction conversion rate of the alkanolamine is 0.05 and T ₁ (° C.), and the maximum temperature in the range of the reaction conversion rate of 0.6 to 0.8 is T ₂ (° C.), The following mathematical formulas (2) to (4) are satisfied.
A method for producing a fatty acid alkanolamide.
0.8 ≦ X / Y ≦ 1.2 (1)
70 ≦ T ₁ ≦ 100 (2)
−5 ≦ T ₂ −T ₁ ≦ 30 (3)
T ₂ ≦ 120 (4)   The method for producing a fatty acid alkanolamide according to claim 1, wherein the step is performed in the presence of a basic catalyst.   The method for producing a fatty acid alkanolamide according to claim 1 or 2, wherein the alkanolamine is a secondary amine. The fatty acid ester is a fatty acid ester represented by the following general formula (1) and / or general formula (2), and the alkanolamine is an alkanolamine represented by the following general formula (3). The manufacturing method of the fatty acid alkanolamide in any one.

(However, R ¹ , R ² and R ³ are each an alkyl group having 1 to 21 carbon atoms, an alkenyl group having 3 to 21 carbon atoms, a hydroxyalkyl group having 1 to 21 carbon atoms, or a group having 3 to 21 carbon atoms. It is a hydroxyalkenyl group and may be different from each other or the same.

(However, R ⁴ is an alkyl group having 1 to 21 carbon atoms, an alkenyl group having 3 to 21 carbon atoms, a hydroxyalkyl group having 1 to 21 carbon atoms, or a hydroxyalkenyl group having 3 to 21 carbon atoms. R ⁵ is an alkyl group having 1 to 6 carbon atoms.)

(However, R ⁶ and R ⁷ are each a hydrocarbon group having 1 to 6 carbon atoms, and may be different or the same.) It is 75 ≦ T ₁ ≦ 85, the manufacturing method of the fatty acid alkanolamide according to claim 1. The method for producing a fatty acid alkanolamide according to claim 1, wherein 5 ≦ T ₂ −T ₁ ≦ 15.   A surfactant composition comprising a fatty acid alkanolamide obtained by the production method according to claim 1 and an anionic surfactant.