JPH0912724A - Production of diorganopolysiloxane - Google Patents

Abstract

PURPOSE: To obtain the subject compound in high purity and productivity without causing side reactions by reacting a specific polysiloxane with a (meth) acryloyl halide. CONSTITUTION: The objective compound of formula III can be produced by reacting (A) a functional diorganopolysiloxane having amino group on one terminal and expressed by formula I (R and R<1> are each a univalent hydrocarbon group; R<2> is a bivalent organic group; R<3> is H or a univalent hydrocarbon group; (n) is 0-1,000) with (B) an acryloyl halide or a methacryloyl halide of formula II (R<4> is H or methyl; X is a halogen) in the presence of (C) an aqueous solution of an alkaline substance (e.g. sodium hydroxide). The reaction is preferably carried out at 0-10 deg.C using 1.0-1.5 equivalent of the component B based on the component A and 1.0-2.0 equivalent of the component C based on the component B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel method for producing a diorganopolysiloxane functionalized with acrylamide or methacrylamide at one end.

[0002]

2. Description of the Related Art Organopolysiloxanes having organic functional groups are modified to give organic resins the characteristics of organopolysiloxanes such as weather resistance, surface water repellency, lubricity, biocompatibility and gas permeability. Used as an agent. Among these, the diorganopolysiloxane having an organic functional group only at one end of the molecular chain has a large modifying effect, and up to now, diorganopolysiloxane having various functional groups has been proposed. Conventionally, among such one-terminal organofunctional diorganopolysiloxanes, one-terminal acrylamide group- or methacrylamide group-functional diorganopolysiloxane is one-terminal amino group-functional diorganopolysiloxane and acrylic acid such as acid chloride. Method of reacting an acid or a derivative of methacrylic acid, or a method of hydrosilylating a compound having an acrylamide group or a methacrylamide group and an aliphatic double bond with a silicon atom-bonded hydrogen atom functional diorganopolysiloxane having one terminal (See, for example, Japanese Patent Laid-Open No. 5-17577). However, in the former method, it is essential to add a tertiary amine such as triethylamine in order to capture hydrogen chloride generated during the reaction and to accelerate the reaction smoothly. There is a problem that it is very difficult to completely remove the hydrochloride from the product. Further, there has been a problem that the purity of a target polymer is often lowered due to a homopolymerization reaction of an acrylamide group or a methacrylamide group.
Further, in the case of using acrylic acid chloride, an unreacted amino group in the amino-functional diorganopolysiloxane having one terminal and an acrylic group in the acrylic acid chloride or the acrylamide-functional diorganopolysiloxane as a product are used. However, there is a problem in that the purity of the target polymer is reduced by the side reaction of Michael addition type. The latter method is carried out under heating conditions in order to accelerate the reaction, but under this reaction condition, a homopolymerization reaction of an acrylamide group or a methacrylamide group often occurs, resulting in a decrease in the purity of the obtained polymer. There was a point. In order to solve these problems, impurities such as tertiary amine hydrochloride are not mixed, homopolymerization reaction of acrylamide group or methacrylamide group and Michael addition type side reaction do not occur, and highly pure one-end acrylamide group Further, there has been a demand for a method capable of producing a methacrylamide group-functional diorganopolysiloxane with high productivity.

[0003]

The present inventor has arrived at the present invention as a result of research for solving the above problems. That is, an object of the present invention is to provide a method capable of producing a highly pure diorganopolysiloxane functionalized with an acrylamide group or a methacrylamide group at one end with high productivity without causing a side reaction.

[0004]

The present invention has the general formula: (A)

Embedded image (In the formula, R and R ¹ are the same or different monovalent hydrocarbon groups, R ² is a divalent organic group, R ³ is a hydrogen atom or a monovalent hydrocarbon group, and n is an integer of 0 to 1000.) A diorganopolysiloxane functionalized at one end with an amino group and represented by the general formula: (B)

Embedded image (In the formula, R ⁴ is a hydrogen atom or a methyl group, and X is a halogen atom.) An acrylic acid halide or a methacrylic acid halide represented by the formula is reacted in the presence of an aqueous solution of an alkaline substance. Yes, general formula: (C)

[Chemical 6] (In the formula, R, R ¹ , R ² , R ³ and R ⁴ are the same as described above.) The present invention relates to a method for producing a diorganopolysiloxane functionalized with an acrylamide group or a methacrylamide group at one end.

Hereinafter, the present invention will be described in detail. Formula of component (A) used in the present invention

Embedded image The one-terminal amino group-functional diorganopolysiloxane represented by is known as one kind of diorganopolysiloxane having an amino group-containing organic group. Here, in the above formula, R and R ¹ are alkyl groups such as methyl group, ethyl group, propyl group and butyl group, alkenyl groups such as vinyl group, allyl group and hexenyl group, phenyl group and tolyl group. Are monovalent hydrocarbon groups exemplified by aralkyl groups such as aryl group, benzyl group and phenethyl group, R ² is alkylene group such as methylene group, ethylene group and propylene group, and arylene group such as phenylene group Is a divalent organic group, and R ³ is a hydrogen atom or a monovalent hydrocarbon group similar to R ¹ and R ² above. n is an integer of 0 to 1000. Such a diorganopolysiloxane is obtained by, for example, subjecting a diorganopolysiloxane having a silicon-bonded hydrogen atom at one end of a molecular chain and trimethylsilylallylamine to an addition reaction in the presence of a platinum-based catalyst, and then treating with methanol or the like to remove it. It is easily obtained by performing trimethylsilylation. Further, it can be easily obtained by a method of reacting a diorganopolysiloxane having a silanol group at one end of a molecular chain with a cyclic silazane (see JP-A-1-193276). The diorganopolysiloxane having a silanol group at one end of the molecular chain used as a raw material in these methods is obtained by nonequilibrium polymerization of a cyclic organotrisiloxane and then terminating this reaction with an acid. Further, the diorganopolysiloxane having a silicon atom-bonded hydrogen atom at one end of the molecular chain can be easily prepared by reacting the diorganopolysiloxane having a silanol group at one end of the molecular chain with dimethylchlorosilane. Manufactured to. In order to obtain these diorganopolysiloxanes, the method produced by the present inventors according to the methods previously proposed in Japanese Patent Application No. 6-113951 and Japanese Patent Application Laid-Open No. 6-340743 is preferable.

Formula of component (B) used in the present invention

Embedded image The acrylic acid halide or methacrylic acid halide represented by is a component for introducing an acrylamide group or a methacrylamide group into the component (A). Here, in the above formula, R ⁴ is a hydrogen atom or a methyl group, and X is a halogen atom exemplified by a bromine atom and a chlorine atom. Such compounds are commercially available and are easily available.

The method of the present invention comprises the above component (A)
The component (B) is reacted in the presence of an aqueous solution of an alkaline substance, but by reacting in the presence of an aqueous solution of an alkaline substance, the salt produced as a result of the reaction is transferred to the aqueous phase, so that there is no contamination of these components. It is possible to obtain a target polymer having a purity. Such an alkaline substance is not particularly limited in its kind as long as it is water-soluble and has a PK _b larger than PK _b of the amino group in the diorganopolysiloxane functionalized with an amino group at one end. Alkali metal hydroxides such as sodium hydroxide and potassium hydroxide are recommended. The charge ratio of the acrylic acid or methacrylic acid halide of the component (B) to the diorganopolysiloxane having a terminal amino group functional component (A) is preferably in the range of 1.0 to 1.5 equivalents. This is because if the amount is less than 1.0 equivalent, the reaction is not completed and unreacted amino groups remain, and particularly in the case of acrylic acid halide, a Michael addition type side reaction occurs.
If it exceeds 1.5 equivalents, a large amount of unreacted acrylic acid or methacrylic acid halide remains, which is economically disadvantageous. Further, the amount of the alkaline substance used is required to be equal to or more than the neutralization amount of hydrogen halide produced as a by-product, and usually 1.0 to 2.0 with respect to acrylic acid or methacrylic acid halide.
Used within the range of 0 equivalents. This reaction is usually carried out by dropping the acrylic acid or methacrylic acid halide of the component (B) into a mixture of the component (A) diaminopolysiloxane having one terminal amino group functional group and an aqueous solution of an alkaline substance.

This reaction can be carried out in the absence of a solvent, but for facilitating temperature control and facilitating stirring, and facilitating phase separation of the diorganopolysiloxane functionalized at the amino group at one end with the aqueous phase, It is recommended to use organic solvents to prevent emulsification. The organic solvent that can be used is not particularly limited as long as it is compatible with the amino-functional diorganopolysiloxane having one terminal and does not react with the various components used in this reaction. Examples of these organic solvents include aromatic hydrocarbons such as benzene, toluene and xylene, aliphatic hydrocarbons such as hexane and heptane, chlorinated hydrocarbons such as carbon tetrachloride, chloroform and trichloroethane, and ethers such as diethyl ether and tetrahydrofuran. The kind is illustrated.

The reaction temperature is preferably as low as possible so that the aqueous phase does not freeze in order to prevent side reactions from occurring. Therefore, the recommended reaction temperature is 0
It is -20 degreeC, More preferably, it is 0-10 degreeC.
Since this reaction is generally carried out in a heterogeneous two-phase system, it is necessary to carry out vigorous stirring so that the organic phase and the aqueous phase are sufficiently in contact with each other. After completion of the reaction, the aqueous phase is removed, the organic phase is washed with water as necessary, and the low boiling point substances are distilled off under reduced pressure by heating from the organic phase to obtain the desired diacrylamide containing acrylamide group or methacrylamide group functionalized at one end. Polysiloxane can be obtained. In addition, in order to prevent the polymerization reaction of acrylic acid halide or methacrylic acid halide which occurs as a side reaction during the reaction or when removing low-boiling substances, or the polymerization reaction of acrylamide group or methacrylamide group in the reaction product, a normal radical polymerization reaction It is preferable to add a compound known as an inhibitor of Examples of such compounds include phenothiazine, hydroquinone monomethyl ether, and 2,6-di-t-butyl-p-cresol.

[0010]

The present invention will be described below in detail with reference to examples. In the examples, the number average molecular weight and polydispersity by GPC (gel permeation chromatography) are values in terms of standard dimethylpolysiloxane. In addition, trimethylsilanol, dimethylformamide, and acetonitrile were used after being dehydrated by an appropriate means.

[0011]

[Synthesis Example 1] 400 g (1798.0 mmol) of hexamethylcyclotrisiloxane (D ₃ ) was placed in a four-necked flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer.
And 300 g of toluene were added and mixed, and azeotropic dehydration was performed for 1 hour. After cooling the temperature of the reaction system to room temperature, n-
8.0 ml (13.7 mmol) of 1.71N hexane solution of butyllithium was added, and the mixture was stirred at room temperature for 10 minutes. Then trimethylchlorosilane 1.419
After adding gram (13.0 mmol) and stirring at room temperature for 5 minutes, 2.908 g (3
2.2 mmol), 32.0 g of dimethylformamide and 100.0 g of acetonitrile were added thereto, and a white precipitate was formed to start the reaction. The reaction mixture was sampled, 1 drop of acetic acid was added to this sample to stop the reaction, and its conversion rate was monitored by GLC (gas chromatography). 4 hours and 50 minutes later,
When the conversion reached 79.2%, 0.14 g of acetic acid was added to stop the reaction. By-produced salts were filtered off, low-boiling substances were removed by heating under reduced pressure, and after cooling, the precipitated salts were filtered off to obtain dimethylpolysiloxane capped with silanol groups at one end. This dimethyl polysiloxane is GPC
Has a number average molecular weight of 10,068 and a dispersity of 1.
And the silanol group content was 0.19% by weight.

[0012]

[Synthesis Example 2] A mixture of 290 g of dimethylpolysiloxane having a silanol group blocked at one end obtained in Synthesis Example 1 and 200 ml of n-hexane was stirred for 1,2,
A mixed solution of 5.64 g (39.4 mmol) of 2,4-tetramethyl-1-aza-2-silacyclopentane and 100 ml of n-hexane was added dropwise. After the completion of the dropwise addition, the mixture was heated under reflux for 1 hour. n-Hexane and unreacted 1,2,2,4-tetramethyl-1-aza-2-silacyclopentane were removed by heating under reduced pressure to obtain a dimethylpolysiloxane capped with a methylamino group at one end. The NHMe group content was measured, and the calculated value was 0.33% by weight, which was calculated from the silanol group content of the raw material, and the measured value was 0.35.
It was 0% by weight.

[0013]

Example 1 In a four-necked flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer, 30 g (3.5 mmol) of dimethylpolysiloxane blocked with a methylamino group at one end obtained in Synthesis Example 2 was added. A solution of 120 ml of chloroform and 0.22 g (5.23 mmol) of sodium hydroxide in water (30 ml) was added. After cooling with ice water, a mixture of 0.39 g (4.36 mmol) of acrylic acid chloride and 1 ml of chloroform was added dropwise at 0 ° C. After the dropping, stir at 0 ° C for 5 minutes,
The mixture was further stirred at 10 ° C for 10 minutes. The mixture was allowed to stand to separate the organic phase from the aqueous phase, the aqueous phase was removed, the organic phase was washed with water, and sodium sulfate was added to dry the organic phase. Next, 0.003 g of hydroquinone monomethyl ether was added, and low-boiling substances were distilled off under reduced pressure by heating at 40 ° C. or lower. The obtained reaction product was sterilized by filtration to obtain 28.4 g of a colorless and transparent reaction product. This product has ¹³ C-NMR (nuclear magnetic resonance analysis), I
From R (infrared spectroscopic analysis), it was found to be dimethylpolysiloxane having an acrylamide group at one end of the molecular chain. The dimethylpolysiloxane had a number average molecular weight by GPC of 10,068 and a dispersity of 1.06.

[0014]

Example 2 In a four-necked flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer, 120 g (14.0 mmol) of dimethylpolysiloxane capped with a methylamino group at one end obtained in Synthesis Example 2, Chloroform 480 ml and sodium hydroxide 0.85 g (20.57
A solution of water (120 milliliters) was added. After cooling with ice water, acrylic acid chloride 1.
A mixture of 55 grams (17.15 mmol) and 1 ml of chloroform was added dropwise. After the dropping, 5 at 0 ℃
The mixture was stirred for 1 minute and further at 10 ° C. for 10 minutes. The mixture was allowed to stand to separate the organic phase from the aqueous phase, the aqueous phase was removed, the organic phase was washed with water, and sodium sulfate was added to dry the organic phase. Next, 0.012 g of hydroquinone monomethyl ether was added, and low-boiling substances were distilled off under reduced pressure by heating at 40 ° C. or lower. The obtained reaction product is sterilized by filtration to give a colorless and transparent reaction product 2
8.4 grams were obtained. It was found from ¹³ C-NMR (nuclear magnetic resonance analysis) and IR (infrared spectroscopic analysis) that this product was a dimethylpolysiloxane having an acrylamide group at one end of the molecular chain. This dimethylpolysiloxane is
The number average molecular weight by GPC was 9,869, and the dispersity was 1.06.

[0015]

[Comparative Example 1] In a four-necked flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer, 30 g (3.5 mmol) of dimethylpolysiloxane capped with a methylamino group at one end obtained in Synthesis Example 2 was added. A mixture of 0.66 g (6.54 mmol) triethylamine, 0.003 g hydroquinone monomethyl ether and 30 ml n-hexane was charged. After cooling with ice water, 0.39 g (4.36 mmol) of acrylic acid chloride and n were added at 0 ° C.
-A mixture of 1 ml of hexane was added dropwise. After the dropping was completed, the mixture was stirred at 10 ° C. or lower for 10 minutes and further at room temperature overnight. 0.26 g (8.0 mmol) of methanol
Was added and the mixture was stirred for 30 minutes to convert excess acrylic acid chloride into methyl acrylate, and then the by-produced salt was filtered off by sterile filtration. N-Hexane and methyl methacrylate were distilled off from the filtrate by heating under reduced pressure, and sterile filtration was performed. The obtained reaction product was not a colorless and transparent polymer but a pale yellow and cloudy polymer. When this product was analyzed by GPC, the number average molecular weight was 10,399,
The dispersity was 1.07. A shoulder was formed on the high molecular weight side of the main peak, but this was a single reaction product of the acrylamide group in the product or the unreacted methylamino group and the one terminal acrylamide in the dimethylpolysiloxane blocked with a methylamino group at one end. It was suspected to have been formed by a Michael addition-type side reaction with the acrylamide group in the functional dimethylpolysiloxane.

[0016]

According to the production method of the present invention, a highly pure diorganopolysiloxane functionalized with an acrylamide group or a methacrylamide group at one end can be produced with high productivity.

[Brief description of the drawings]

FIG. 1 is a GPC chart of dimethylpolysiloxane having an acrylamide group at one end of a molecular chain obtained in Example 1.

FIG. 2 is a GPC chart of dimethylpolysiloxane having an acrylamide group at one end of a molecular chain obtained in Example 2.

[3] ¹³ C-NMR of dimethylpolysiloxane having an acrylamide group at a molecular chain terminal obtained in Example 2
It is a chart.

FIG. 4 is an IR chart of dimethylpolysiloxane having an acrylamide group at one end of the molecular chain obtained in Example 2.

5 is a GPC chart of dimethylpolysiloxane having an acrylamide group at one end of the molecular chain obtained in Comparative Example 1. FIG.

Claims (1)

[Claims] 1. The general formula: (A) (In the formula, R and R ¹ are the same or different monovalent hydrocarbon groups, R ² is a divalent organic group, R ³ is a hydrogen atom or a monovalent hydrocarbon group, and n is an integer of 0 to 1000.) A diorganopolysiloxane functionalized at one end with an amino group and represented by the general formula: (B) (In the formula, R ⁴ is a hydrogen atom or a methyl group, and X is a halogen atom.) An acrylic acid halide or a methacrylic acid halide represented by the formula is reacted in the presence of an aqueous solution of an alkaline substance. The general formula: (C) (In the formula, R, R ¹ , R ² , R ³ and R ⁴ are the same as described above.) A method for producing a diorganopolysiloxane functionalized at one end with an acrylamide group or a methacrylamide group.