Carboxy group-containing organopolysiloxane, method for producing carboxy group-containing organopolysiloxane, and surfactant

Abstract

To provide a carboxylated organopolysiloxane having an ether bond and an ester bond as linkers, and also provide a method for producing the carboxylated organopolysiloxane without a peculiar odor derived from carboxylic acid.SOLUTION: The present invention relates to a carboxylated organopolysiloxane represented by general formula (1). [In the formula, R are each independently a group selected from C1-C6 alkyl groups, C6-C10 aryl groups, and C7-C10 aralkyl groups, x is an integer of 0-400, y is an integer of 1-100, n is an integer of 1-30, X1 is a C2-C6 alkylene group, and X2 is a C2-C6 alkylene group].SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a carboxyl group-containing organopolysiloxane, a method for producing a carboxyl group-containing organopolysiloxane, and a surfactant. [Background technology]

[0002] Emulsification technologies used in the production of cosmetics are becoming more sophisticated and diverse. Among these, polysiloxanes incorporating hydrophilic organic groups are often used in cosmetics because they can orient at the water / oil interface and produce stable emulsions. Ether bonds and hydroxyl groups have been investigated as hydrophilic organic groups, but in recent years, the introduction of carboxyl groups has been reported.

[0003] Previously, methods for linking carboxyl groups to silicones have been disclosed (Patent Documents 1 and 2), as well as compounds obtained by these methods. These methods involve the following two-step reaction: First, a catalytic addition reaction is carried out between a carboxylic acid protected with a silyl group having a double bond at its terminal and a methylhydrogenpolysiloxane. Next, the silyl group is deprotected to obtain the desired carboxyl-containing organopolysiloxane. However, with this synthesis method, residual carboxylic acid from the raw material can cause a problem of an unpleasant odor unsuitable for cosmetics.

[0004] Furthermore, the known methods have the drawback of using a long-chain alkylene group with low hydrophilicity as a linker. To achieve higher surface activity, it is desirable to introduce a hydrophilic linker such as an ether bond or an ester bond. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-266285 [Patent Document 2] Japanese Patent Publication No. 2020-29453 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a carboxyl-containing organopolysiloxane having ether bonds and ester bonds as linkers, and a method for producing the carboxyl-containing organopolysiloxane that is free of the characteristic odor derived from carboxylic acids. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides: The present invention provides a carboxyl group-containing organopolysiloxane represented by the following general formula (1): [ka] [In the formula, R is independently a group selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms; x is an integer of 0 to 400; y is an integer of 1 to 100; n is an integer of 1 to 30; and X 1 is an alkylene group having 2 to 6 carbon atoms, X 2 is an alkylene group having 2 to 6 carbon atoms.

[0008] The carboxyl group-containing organopolysiloxane of the present invention is highly hydrophilic and exhibits high surface activity.

[0009] The present invention also provides a method for producing the above-mentioned carboxyl-containing organopolysiloxane, which comprises reacting (A) a hydroxyl-containing organopolysiloxane represented by the following general formula (2) with (B) a cyclic acid anhydride represented by the following general formula (3) in the presence of an amine compound: [ka] [In the formula, R is independently a group selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms; x is an integer of 0 to 400; y is an integer of 1 to 100; n is an integer of 1 to 30; and X 1 is an alkylene group having 2 to 6 carbon atoms. [ka] [where, X 2 is an alkylene group having 2 to 6 carbon atoms.

[0010] This production method makes it possible to obtain the desired carboxyl-containing organopolysiloxane, free from the characteristic odor derived from carboxylic acids.

[0011] The present invention also provides a surfactant that contains the above-mentioned carboxy-containing organopolysiloxane.

[0012] This surfactant is highly hydrophilic and exhibits high surface activity. [Effects of the Invention]

[0013] According to the present invention, it is possible to produce a carboxyl-containing organopolysiloxane having an ether bond and an ester bond in the linker. Furthermore, since the cyclic acid anhydride used as the raw material can be easily removed by washing with water, the carboxyl-containing organopolysiloxane does not have a distinctive odor. Furthermore, the inclusion of an ether bond and an ester bond in the linker improves hydrophilicity, resulting in an organopolysiloxane with excellent surfactant properties. Therefore, the organopolysiloxane of the present invention is suitable for use in cosmetics and the like. DETAILED DESCRIPTION OF THE INVENTION

[0014] There has been a need for a carboxyl group-containing organopolysiloxane, which is a compound in which a carboxyl group is linked to a silicone, that exhibits good surface activity, and a method for obtaining such a carboxyl group-containing organopolysiloxane that is free from the characteristic odor unsuitable for cosmetics that is generated by the residual carboxylic acid of the raw material.

[0015] As a result of extensive research conducted by the present inventors in order to achieve the above object, they discovered that a carboxyl-containing organopolysiloxane having high surface activity can be produced by reacting a hydroxyl-containing organopolysiloxane with a cyclic acid anhydride in the presence of an amine compound, and thus completed the present invention.

[0016] That is, the present invention provides: The organopolysiloxane is a carboxyl group-containing organopolysiloxane represented by the following general formula (1). [ka] [In the formula, R is independently a group selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms; x is an integer of 0 to 400; y is an integer of 1 to 100; n is an integer of 1 to 30; and X 1 is an alkylene group having 2 to 6 carbon atoms, X 2 is an alkylene group having 2 to 6 carbon atoms.

[0017] The present invention will be described in detail below.

[0018] [Organopolysiloxane] The organopolysiloxane of the present invention is represented by the following general formula (1) which has an oxyalkylene group and a linker containing an ester bond. [ka] [In the formula, R is independently a group selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms; x is an integer of 0 to 400; y is an integer of 1 to 100; n is an integer of 1 to 30; and X 1 is an alkylene group having 2 to 6 carbon atoms, X 2 is an alkylene group having 2 to 6 carbon atoms.

[0019] In the above general formula (1), R is selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms include alkyl groups such as a methyl group, an ethyl group, a propyl group, and a butyl group; and cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group. Examples of the aryl group having 6 to 10 carbon atoms include a methylphenyl group and an ethylphenyl group. Examples of the aralkyl group having 7 to 10 carbon atoms include a phenylmethyl group and a phenylethyl group. X 1 is selected from alkylene groups having 2 to 6 carbon atoms. Examples of alkylene groups having 2 to 6 carbon atoms include an ethylene group and a propylene group. X 2 is selected from alkylene groups having 2 to 6 carbon atoms. Examples of alkylene groups having 2 to 6 carbon atoms include an ethylene group, a propylene group, and a butylene group.

[0020] In the general formula (1), x is a number from 0 to 400, preferably from 5 to 100, y is a number from 1 to 100, preferably from 1 to 20, n is a number from 1 to 30, preferably from 1 to 10, and X 1 The number of carbon atoms is 2 to 6, preferably 2 to 4. The bonding order of the siloxane units bounded by x and y may be block or random.

[0021] Furthermore, the carboxyl group-containing organopolysiloxane is preferably a reaction product (hereinafter simply referred to as the reaction product) of an organopolysiloxane represented by formula (2) and a cyclic acid anhydride represented by formula (3), as described in the production method described below.

[0022] [Method for producing organopolysiloxane] The method for producing an organopolysiloxane of the present invention (hereinafter sometimes abbreviated as "the production method of the present invention") comprises the step of reacting (A) a hydroxyl group-containing organosiloxane represented by the following general formula (2) with (B) a cyclic acid anhydride represented by the following general formula (3) in the presence of an amine. [ka] [In the formula, R is independently a group selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms; x is an integer of 0 to 400; y is an integer of 1 to 100; n is an integer of 1 to 30; and X 1 is an alkylene group having 2 to 6 carbon atoms. [ka] [where, X 2 is an alkylene group having 2 to 6 carbon atoms.

[0023] In the above general formula (2), R is selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms include alkyl groups such as a methyl group, an ethyl group, a propyl group, and a butyl group; and cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group. Examples of the aryl group having 6 to 10 carbon atoms include a methylphenyl group and an ethylphenyl group. Examples of the aralkyl group having 7 to 10 carbon atoms include a phenylmethyl group and a phenylethyl group. X 1 is selected from alkylene groups having 2 to 6 carbon atoms. Examples of alkylene groups having 2 to 6 carbon atoms include an ethylene group and a propylene group.

[0024] In the above general formula (3), X 2 is selected from alkylene groups having 2 to 6 carbon atoms. Examples of alkylene groups having 2 to 6 carbon atoms include an ethylene group, a propylene group, and a butylene group.

[0025] In the general formula (2), x is a number from 0 to 400, preferably from 5 to 100, y is a number from 1 to 100, preferably from 1 to 20, n is a number from 1 to 30, preferably from 1 to 10, and X 1 The number of carbon atoms is 2 to 6, preferably 2 to 4. The bonding order of the siloxane units bounded by x and y may be block or random.

[0026] In the production method of the present invention, the molar ratio of the cyclic acid anhydride of the above general formula (3) to the hydroxy group in the above general formula (2) is preferably 1 to 10 times, more preferably 1 to 3 times.

[0027] Examples of amines that can be used in the production method of the present invention include chain aliphatic tertiary amines such as triethylamine, diisopropylethylamine, and tri-n-propylamine, cyclic aliphatic tertiary amines such as 1,8-diazabicyclo[5.4.0]undec-7-ene and 1,4-diazabicyclo[2.2.2]octane, and heterocyclic amines such as pyridine. Among these amines, chain aliphatic tertiary amines are preferred, and triethylamine is most preferred.

[0028] In the production method of the present invention, the amount (mass) of the amine used is not particularly limited, but it is preferable that the amount of amino groups in the amine is 0.1 to 5 equivalents relative to the amount of hydroxyl groups.

[0029] In the production method of the present invention, the reaction temperature in the step of reacting (A) the hydroxyl group-containing organosiloxane represented by the above general formula (2) with (B) the cyclic acid anhydride represented by the above general formula (3) in the presence of an amine is preferably 50°C or higher and 90°C or lower, more preferably 60°C or higher and 80°C or lower, and most preferably 65°C or higher and 75°C or lower.

[0030] In the production method of the present invention, the reaction conditions such as the reaction time and the solvent used are not particularly limited. The reaction time is preferably 1 to 48 hours, more preferably 1 to 24 hours, and most preferably 2 to 12 hours. The solvent is preferably an ether solvent such as tetrahydrofuran or cyclopentyl methyl ether.

[0031] The present invention also provides a surfactant containing the above-mentioned carboxy-containing organopolysiloxane.

[0032] This surfactant exhibits high surface activity due to its high hydrophilicity, and is capable of effectively reducing interfacial tension, which can be measured by the Wilhelmy method. [Example]

[0033] The present invention will be explained in more detail below by way of synthesis examples and examples, but these examples can be modified as appropriate depending on the purpose. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

[0034] [Synthesis Example 1] A separable flask equipped with a thermometer, stirrer, and reflux condenser was charged with 30.00 g of a hydroxyl-containing organopolysiloxane represented by the following formula (a), 2.14 g of succinic anhydride (an amount such that the ratio of the number of moles of succinic anhydride to the total number of moles of hydroxyl groups in the hydroxyl-containing organopolysiloxane was 1.2), 0.90 g of triethylamine, and 36 g of tetrahydrofuran, and the mixture was heated and stirred at 70°C for 3.5 hours. After the reaction was completed, low-boiling fractions were removed at 60°C under a reduced pressure of 0.4 kPa for 1 hour. Next, 22 g of acetone and 22 g of 1N hydrochloric acid were added, and the mixture was stirred at room temperature for 1 hour. The mixture was then allowed to stand, and the silicone layer was separated and collected. 22 g of acetone and 22 g of water were added to the resulting silicone layer, and this separation and washing procedure was repeated three times. The low boiling point fraction was removed under reduced pressure of 0.4 kPa at 100°C for 1 hour, yielding 13.6 g of a carboxyl group-containing organopolysiloxane (polysiloxane b) represented by the following formula (b). 1 H-NMR analysis revealed no unreacted hydroxy groups, and no peculiar odor. [ka] [ka] 1 The H-NMR spectrum is shown below. 1 H-NMR(400MHz, CDCl3):δ -0.40~0.24(m,387H), 0.41~0.54(m,6H), 1.53~1.67(m,6H), 2.65(br,12H), 3.40(t,J=7.0Hz,6H), 3.60(t,J=4.8Hz,6H), 4.22(t,4.4Hz,6H).

[0035] [Synthesis Example 2] Synthesis was carried out in the same manner as in Synthesis Example 1, except that 30.00 g of a hydroxyl-containing organopolysiloxane represented by the following formula (c), 3.73 g of succinic anhydride (an amount such that the ratio of the number of moles of succinic anhydride to the total number of moles of hydroxyl groups in the hydroxyl-containing organopolysiloxane was 1.3), 1.56 g of triethylamine, and 36 g of tetrahydrofuran were used. 18.0 g of a carboxyl-containing organopolysiloxane represented by the following formula (d) (polysiloxane d) was obtained. [ka] [ka] 1 H-NMR(400MHz, CDCl3):δ -0.30~0.23(m,300H), 0.41~0.52(m,8H), 1.53~1.67(m,8H), 2.64(br,16H), 3.40(t,J=6.8Hz,8H), 3.60(t,J=4.2Hz,8H), 4.22(t,4.3Hz,8H).

[0036] [Surface tension test] [Example 1] A surface tension test was carried out on the carboxyl group-containing organopolysiloxane obtained in Synthesis Example 1. The kinematic viscosity was 6 mm 2 The carboxyl group-containing polysiloxane was dissolved in dimethyl silicone oil (trade name: KF-96A-6cs, manufactured by Shin-Etsu Chemical Co., Ltd.) at 1 / s, and the concentration of the carboxyl group-containing polysiloxane was adjusted to 0.01 wt%. A two-layer liquid was created using this dimethyl silicone solution and ion-exchanged water. The interfacial tension was measured by the Wilhelmy method using a high-precision surface tensiometer DY-700 (manufactured by Kyowa Interface Science Co., Ltd.) 0 hours and 5 hours after the two-layer liquid was created, and the interfacial activity was evaluated.

[0037] [Examples 2 to 4] Two-layer solutions of dimethylsilicone solutions and ion-exchanged water in Examples 2 to 4 were prepared in the same manner as in Example 1, except that the carboxyl group-containing organopolysiloxane and its concentration were changed as shown in Table 1, and the surface activity was evaluated. The results are shown in Table 1.

[0038] [Comparative Example 1] Dynamic viscosity is 6mm 2 Except for preparing a two-layer liquid of dimethyl silicone oil (trade name: KF-96A-6cs, manufactured by Shin-Etsu Chemical Co., Ltd.) and ion-exchanged water, which is a soluble fiber, the surface activity was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0039] [Table 1]

[0040] The carboxyl group-containing organopolysiloxane of the present invention exhibited higher surface activity than the blank experiment of Comparative Example 1. [Industrial Applicability]

[0041] The polysiloxane of the present invention exhibits high surfactant properties and does not have a distinctive odor, making it useful in cosmetic compositions for skin care, hair, antiperspirants, deodorants, makeup, and UV protection.

[0042] The present invention is not limited to the above-described embodiments. The above-described embodiments are merely examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits similar effects is included within the technical scope of the present invention.

Claims

[Claim 1] A method for producing a carboxyl group-containing organopolysiloxane represented by the following general formula (1), comprising reacting (A) a hydroxyl group-containing organopolysiloxane represented by the following general formula (2) with (B) a cyclic acid anhydride represented by the following general formula (3) in the presence of an amine compound. 【Chemistry 1】 [In the formula, R is independently a group selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms; x is an integer of 0 to 400; y is an integer of 1 to 100; n is an integer of 1 to 30; and X １ is an alkylene group having 2 to 6 carbon atoms, X ２ is an alkylene group having 2 to 6 carbon atoms. 【Chemistry 2】 [In the formula, R is independently a group selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms; x is an integer of 0 to 400; y is an integer of 1 to 100; n is an integer of 1 to 30; and X １ is an alkylene group having 2 to 6 carbon atoms. 【Transformation 3】 [In the formula, X ２ is an alkylene group having 2 to 6 carbon atoms.

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