JPH0617480B2 - Method for producing dimethylsiloxane block copolymer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a polymer compound, and more particularly to a method for producing a dimethylsiloxane block copolymer.

(Prior Art) A dimethylsiloxane block copolymer has been conventionally synthesized by several methods.

For example, JCSaam et al., Macromolecules, Vol. 3, p. 1 (1970)
Reported that a styrene-dimethylsiloxane block copolymer was obtained by an anionic polymerization method (hereinafter, this method is referred to as an anionic polymerization method).

In addition, Ikushi Tezuka et al. (Makromol. Chem., Rapid Commu)
n.) Volume 5, p. 559 (1984), reported that a vinyl acetate-dimethylsiloxane block copolymer was obtained by a coupling reaction of a prepolymer having a functional group (hereinafter, this method is referred to as Called the polymer method).

Furthermore, Hiroshi Inoue et al. Proceedings of the Society of Polymer Science, Vol. 34, p. 293 (1
(984), it was reported that a methyl methacrylate-dimethylsiloxane block copolymer was obtained by radical polymerization with an azo group-containing polysiloxane amide having radical polymerization activity (hereinafter, this method is referred to as azo group-containing polysiloxane amide. Called method).

(Problems to be Solved by the Invention) However, the conventional synthesis method has some problems as described below.

1) In the method using the anionic polymerization method or the prepolymer method, the vinyl-type monomer applicable to the reaction is limited, and the reaction steps are multistage, and the reaction conditions are difficult to industrially use. It is.

2) In the method using the azo group-containing polysiloxane amide, the temperature at which the half-life of the polymer initiator is 10 hours is about 65 ° C.
It is not suitable for use in a wide range of temperatures.

In order to industrially produce a block copolymer, it is necessary that it can be synthesized by radical polymerization and can be synthesized at a wide range of temperatures from low temperature to high temperature.

The object of the present invention is to solve these problems and provide a method for producing a dimethylsiloxane block copolymer by radical polymerization, which can be applied to many vinyl type monomers, has a small number of reaction steps, and can be synthesized at a wide range of temperatures. Especially.

(Means for Solving Problems) The object of the present invention is achieved by the method for producing a dimethylsiloxane block copolymer described below.

In the method for producing a dimethylsiloxane block copolymer of the present invention, in polymerizing a vinyl-type monomer, a polydimethylsiloxane compound having a diacyl-peroxy group in a molecule represented by the following structural formula (A) is radical-polymerized. A method for producing a dimethylsiloxane block copolymer, which is characterized in that it is used as an initiator.

(In the formula, R ₁ represents an alkyl group or an aryl group having 1 to 15 carbon atoms. Further, R represents an alkylene group having 3 to 10 carbon atoms or Represents a group, R ₂ represents an alkylene group having 1 to 15 carbon atoms or a phenylene group, and R ₃ represents an alkylene group having 3 to 10 carbon atoms or a — (CH ₂ ) ₂ O (CH ₂ ) ₃ — group. Also, m is 10 to 200
And x is 2-10).

The present invention will be described in more detail below.

The polydimethylsiloxane compound having a diacyl peroxy group in the molecule used in the present invention is represented by the above structural formula (A). R ₁ in the formula is an alkyl group having 1 to 15 carbon atoms or a phenyl group. When the carbon number is 16 or more, the reactivity becomes poor and the synthesis becomes difficult. For R and R _{3 under the} conditions other than the above, it is difficult to obtain raw materials and difficult to synthesize. Further, m is 10 to 200 and x is 2 to 10. m> 200
, The molecular weight becomes too large and the synthesis is difficult.
In the case of 10, the amount of dimethylsiloxane component is small and the characteristics cannot be exhibited. When x is 11 or more, synthesis becomes difficult.

The compound represented by the structural formula (A) can obtain a half-life of 10 hours at a temperature in the range of about 60 to 80 ° C. and has a radical polymerization property that can be used as one component of the copolymer. In addition, this polydimethylsiloxane compound has the same solubility as ordinary polydimethylsiloxane, benzene,
Easily soluble in toluene, xylene, hexane, etc.

The polydimethylsiloxane compound represented by the structural formula (A) used in the present invention can be produced by the following method using a bifunctional carboxyl-terminated polydimethylsiloxane or a bifunctional hydroxy-terminated polydimethylsiloxane as a starting material.

For example, when a bifunctional carboxyl-terminated polydimethylsiloxane is used as a starting material, as shown in the following reaction formula, first, the bifunctional carboxyl-terminated polydimethylsiloxane (I) is subjected to a chlorinating agent ( A chlorination reaction is carried out in the presence of II) to produce a polydimethylsiloxane (III) having a chloroacyl group in the molecule.

The above reaction may be performed under almost the same reaction conditions as in the case of the known acid chloride. The reaction temperature is preferably 20 to 60 ° C., and the reaction time is preferably 1 to 5 hours. Also, (I) and (II)
The molar ratio of is preferably 1: 1 to 2. Examples of (II) include thionyl chloride, phosphorus trichloride and phosphorus pentachloride.

Then, by reacting this (III) and R ₁ COCl (IV) with potassium peroxide by a conventional method, as shown in the following reaction formula, a polyacyl group having diacyl-peroxy groups at both terminals and main chain of the molecule is obtained. A siloxane compound is formed.

(Here, R ₂ represents an alkylene group having 3 to 10 carbon atoms,
m is 10 to 200 and x is 2 to 10. The above reaction may be carried out under almost the same reaction conditions as in the case of the known diacyl peroxide. The reaction temperature is 10 to 30 ° C,
The reaction time is preferably 0 to 10 ° C and the reaction time is 0.25 to 3 hours, preferably 0.5 to 1.5 hours. The molar ratio of (III) to potassium peroxide is 1: 1 to 3, preferably 1: 1 to 2. The concentration of the potassium peroxide aqueous solution is 1 to 15%, preferably 2 to
5%. The molar ratio of (III) and (IV) is 1 to
5: 1 is desirable.

When the m in the above formula (I) is large, the viscosity becomes high, so it is desirable to react in a solvent such as toluene or xylene.

In addition, when a difunctional hydroxyl-terminated polydimethylsiloxane is used as a starting material, first, the difunctional hydroxyl-terminated polydimethylsiloxane and the dibasic acid chloride are subjected to a dehydrochlorination reaction in a dry nitrogen stream to form a chloroacyl group in the molecule. Also, the polydimethylsiloxane compound (A) can be produced via a polydimethylsiloxane having an ester group.

Next, as the vinyl type monomer usable in the present invention, styrene, methylstyrene, diphenylethylene, ethylstyrene, dimethylstyrene, vinylnaphthalene, vinylphenanthrene, vinylmesitylene, 3,4,6-trimethylstyrene, 1-vinyl are used. Hydrocarbon compounds such as 2-ethylacetylene, butadiene, isoprene, piperylene; chlorostyrene, methoxystyrene, bromstyrene, cyanostyrene, fluorostyrene, dichlorostyrene, N, N-dimethylaminostyrene, nitrostyrene, chloromethyl Styrene derivatives such as styrene, trifluorostyrene, trifluoromethylstyrene, aminostyrene; acrylonitrile, methacrylonitrile, α
Acrylonitrile derivatives such as acetoxyacrylonitrile; acrylic acid, methacrylic acid; methyl acrylate,
Acrylic esters such as lauryl acrylate, chlormethyl acrylate, ethyl acetoxyacrylate; Methacrylic acid esters such as cyclohexyl methacrylate, dimethylaminoethyl methacrylate, glycidyl methacrylate, tetrahydrofurfuryl methacrylate, hydroxyethyl methacrylate; vinylidene chloride , Vinylidene bromide, vinylidene cyanide and the like; acrylamide derivatives such as acrylamide, methacrylamide, N-butoxymethyl acrylamide, N-phenyl acrylamide, diacetone acrylamide, N, N-dimethylaminoethyl acrylamide; vinyl acetate, butyric acid Fatty acid vinyl derivatives such as vinyl and vinyl caprate; further, N-vinyl succinimide, N-vinyl pyrrolidone, N-vinyl lid Imide, N- vinyl carbazole, vinyl furan, 2-vinyl benzofuran, Biniruchiofuen, vinylimidazole, methylvinyl imidazole, polyvinyl pyrazole, vinyl oxazolidone, vinyl thiazole, vinyl tetrazole, vinyl pyridine,
There are heterocyclic vinyl compounds such as methylvinylpyridine, 2,4-dimethyl-6-vinyltriazine and vinylquinoline.

The vinyl type monomer may be used alone or in combination of two or more kinds.

The composition ratio of the polydimethylsiloxane compound having a diacyl-peroxy group in the molecule and the vinyl monomer is generally 10 to 90 parts by weight of the polydimethylsiloxane compound having a diacyl-peroxy group in the molecule, based on the vinyl-type monomer. 90 to 10 parts by weight of the monomer is preferable, and the ratio can be selected within a wide range according to the intended use. If the amount of the polydimethylsiloxane compound is less than 10 parts by weight or more than 90 parts by weight, the characteristics of the block copolymer cannot be exhibited.

Further, as the radical polymerization method, any method such as a solution polymerization method, a bulk polymerization method, an emulsion polymerization method and a suspension polymerization method can be performed.

The reaction temperature for radical polymerization is 30 to 120 ° C, preferably 50 to 100 ° C. If the reaction temperature is lower than 30 ° C, the reaction time becomes too long, which is industrially unsuitable. Also, 12
If the temperature is higher than 0 ° C, the peroxy group will be instantly decomposed,
The reaction doesn't go well.

The reaction time is generally 0.5 to 100 hours, preferably 1 to 30 hours. If the reaction time is shorter than 0.5 hours, the reaction will not proceed sufficiently. If it is longer than 100 hours, it is industrially unsuitable.

As described above, when the method for producing a dimethylsiloxane block copolymer according to the present invention is used, a dimethylsiloxane block copolymer can be obtained by a one-step reaction. The dimethylsiloxane block copolymer obtained contains a homopolymer of a vinyl-type monomer, but by performing reprecipitation or solvent extraction with a suitable solvent, the block copolymer with high purity can be obtained. Can be separated.

(Effect of the Invention) The method for producing a dimethylsiloxane block copolymer according to the present invention can be applied to many vinyl type monomers, and the reaction can be carried out in one step over a wide range of temperatures by an extremely simple operation. As a result, various dimethylsiloxane block copolymers can be produced, and the industrial value is extremely high. Furthermore, the dimethylsiloxane block copolymer obtained according to the present invention can be used as a raw material for sealing agents, various plastic films and molded products, fibers, rubber, paints, adhesives, etc. and surface modifiers. The properties of polydimethylsiloxane such as the properties and weather resistance can be imparted.

(Example) Next, the present invention will be described with reference to synthesis examples, examples and comparative examples. Parts in the examples indicate parts by weight. The polydimethylsiloxane compounds represented by the structural formulas (1) to (4) used in the examples were all synthesized according to the following synthesis examples.

Synthesis example In a four-necked flask equipped with a stirrer and a reflux condenser, 34.4 g of α, ω-bis-10-carboxydecylpolydimethylsiloxane having an average molecular weight of 1720 and thionyl chloride (purity 99
%) 8.6 g was introduced. While blowing dry nitrogen into this, the reaction was carried out at a reaction temperature of 50 ° C. for 3 hours. Then, it was suctioned with a water pump at 40 to 45 ° C. for 1 hour to maintain a reduced pressure of 10 to 20 mmHg to remove the remaining thionyl chloride. Thus, 34.9 g (purity 99.5%, yield 97.1%) of polydimethylsiloxane having a chloroacyl group in the molecule of a yellow transparent liquid was obtained.

Next, an aqueous potassium peroxide solution was prepared from 3.8 g of a 60% aqueous hydrogen peroxide solution and 248.8 g of a 5% aqueous potassium carbonate solution, and 35.0 g of tetrahydrofuran was introduced thereinto. Further, 34.9 g of polydimethylsiloxane having a chloroacyl group in the molecule obtained by the above reaction and lauric acid chloride (purity 99
%) 1.5 g was added little by little while stirring at 0-5 ° C. After stirring at the same temperature for 1 hour, an aqueous layer and an oil layer were separated. Then, the obtained liquid material was washed twice with water, anhydrous magnesium sulfate was separated by filtration, and then tetrahydrofuran was removed under vacuum to obtain 34.7 g of a yellow viscous material.

For the yellow viscous product thus obtained, the amount of active oxygen (measured by iodometric titration method), the temperature at which the half-life of the peroxy bond is 10 hours (measured in benzene solvent with initial concentration of peroxy group being 0.1 mol /), number average Molecular weight (Shimadzu high performance liquid chromatography [DETECTOR: RID-2A, PUMP: LC-5A])
Measurement), infrared absorption spectrum (measured by JASCO IR-810 type infrared spectrophotometer), and nuclear magnetic resonance absorption spectrum (measured by JEOL FX90Q FT-NMR apparatus). Characteristic values were shown, and it was confirmed to be a polydimethylsiloxane compound having diacyl-type peroxy groups at both ends of the molecule represented by the structural formula (1) and in the main chain.

Active oxygen content: 0.99% Half-life of peroxy bond is 10 hours Temperature: 62.2 ℃ Number average molecular weight: 10000 Infrared absorption spectrum: 1775cm ^-1 and 1800cm ^-1 (C = O bond of diacyl group) 1101030cm ^-1 ( the bond of Si-O-Si) 1270cm ^-1 (Si-CH ₃ bond) nuclear magnetic resonance spectrum: 0.08ppm 1995H (a) 0.45ppm 76H (b) 1.00ppm 10H (c) 1.25ppm 652H (d) 1.60ppm 76H (e) 2.35 ppm 86H (f) Example 1 The following structural formula (1) having an average molecular weight of 10,000 and an active oxygen content of 0.99%: Into a flask equipped with a reflux condenser and a stirrer was introduced 60 parts of a polydimethylsiloxane compound having a diacyl-peroxy group in the molecule represented by, 40 parts of styrene, and 200 parts of toluene, and the reaction was carried out at 80 ° C. for 20 hours in a nitrogen atmosphere. Let

After completion of the reaction, the content in the flask was put into about 15 times the amount of n-hexane to precipitate a styrene homopolymer, which was removed by filtration. Then, the filtrate was concentrated to about one-third and then poured into about 10-fold amount of methanol to precipitate a polymer, which was filtered and dried under reduced pressure to obtain 80 parts of a pale yellow polymer.

About the pale yellow polymer thus obtained, the average molecular weight [Toyo Soda Kogyo High Performance Liquid Chromatography (PUMP: HL
C-802A, DETECTOR: RI-8000)] and nuclear magnetic resonance absorption spectrum (measured by JEOL FX-90Q FT-NMR system)
The following characteristic values were measured and styrene-
It was confirmed to be a dimethylsiloxane block copolymer.

Number average molecular weight (hereinafter referred to as _n ) 6.01 × 10 ³ Weight average molecular weight (hereinafter referred to as _w ) 1.33 × 10 ⁴ Dispersion ratio (hereinafter referred to as _w / _n ) 2.22 Nuclear magnetic resonance absorption spectrum: 0.08 ppm [methyl dimethylsiloxane] Group (hereinafter Si-CH ₃
6.56ppm and 7.03ppm [Styrene benzene ring (-C below
₆ H ₅ )] Weight ratio of dimethylsiloxane segment in polymer (hereinafter referred to as Si-weight ratio): 61% Example 2 60 parts of the same polydimethylsiloxane compound as used in Example 1, methyl methacrylate 40 parts and 200 parts of toluene were introduced into a flask equipped with a reflux condenser and a stirrer, and reacted at 80 ° C. for 20 hours in a nitrogen atmosphere.

After completion of the reaction, the content of the flask was put into about 15 times the amount of n-hexane to precipitate a methyl methacrylate homopolymer, which was removed by filtration. Then, the filtrate was concentrated to about one-third and then poured into about 10-fold amount of methanol to precipitate a polymer, which was filtered and dried under reduced pressure to obtain 70 parts of a pale yellow polymer.

Physical properties of the light yellow polymer thus obtained were measured in the same manner as in Example 1, and the following characteristic values were obtained.
It was confirmed to be a methyl methacrylate-dimethyl siloxane block copolymer. _n 9.23 × 10 ³ _w 2.24 × 10 ⁴ _w / _n 2.43 Nuclear magnetic resonance spectrum: 0.08 ppm (Si-CH ₃ ) 3.67 ppm [methyl ester group of methyl methacrylate (hereinafter referred to as -COOCH ₃ group)] Si-weight ratio : 64% Example 3 The following structural formula (2) having an average molecular weight of 12000 and an active oxygen content of 0.61%: Into a flask equipped with a reflux condenser and a stirrer were introduced 50 parts of a polydimethylsiloxane compound having a diacyl-type peroxy group represented by the formula (1), 50 parts of styrene, and 200 parts of toluene.

Then, 84 parts of a pale yellow polymer were obtained by the same operation as in the production method described in Example 1.

Physical properties of the light yellow polymer thus obtained were measured in the same manner as in Example 1, and the following characteristic values were obtained.
It was confirmed to be a styrene-dimethylsiloxane block copolymer. _n 1.12 × 10 ⁴ _w 2.61 × 10 ⁴ _w / _n 2.33 Nuclear magnetic resonance spectrum: 0.08 ppm (Si-CH ₃ ) 6.56 ppm and 7.03 ppm (-C ₆ H ₅ ) Si-weight ratio: 52% Example 4 Implementation 50 parts of the same polydimethylsiloxane compound used in Example 3, 50 parts of methyl methacrylate, and toluene 200 were introduced into a flask equipped with a reflux condenser and stirrer.

Then, the same procedure as in the production method described in Example 2 was followed to obtain 73 parts of a pale yellow polymer.

Physical properties of the light yellow polymer thus obtained were measured in the same manner as in Example 1, and the following characteristic values were obtained.
It was confirmed to be a methyl methacrylate-dimethyl siloxane block copolymer. _n 2.58 × 10 ⁴ _w 6.58 × 10 ⁴ _w / _n 2.55 Nuclear magnetic resonance spectrum: 0.08 ppm (Si-CH ₃ ) 3.67 ppm (-COOCH ₃ ) Si-weight ratio: 54% Example 5 Average molecular weight 15100 and active oxygen 30 parts by weight of 0.37% polydimethylsiloxane compound having diacyl-peroxy group in the molecule represented by the following structural formula (3), styrene 70
And 200 parts of toluene were introduced into a flask equipped with a reflux condenser and a stirrer, and reacted at 90 ° C. for 20 hours in a nitrogen atmosphere.

The same procedure as the production method described in Example 1 was followed to obtain 87 parts of a white polymer.

Physical properties of the white polymer thus obtained were measured in the same manner as in Example 1. The following characteristic values were shown, and it was confirmed that the white polymer was a styrene-dimethylsiloxane block copolymer. _n 2.88 × 10 ⁴ _w 7.43 × 10 ⁴ _w / _n 2.58 Nuclear magnetic resonance spectrum: 0.08 ppm (Si-CH ₃ ) 6.56 ppm and 7.03 ppm (-C ₆ H ₅ ) Si-weight ratio: 32% Example 6 average Using a reflux condenser and a stirrer, 30 parts of a polydimethylsiloxane compound having a molecular weight of 16500 and an active oxygen content of 0.36% and having a diacyl-type peroxy group in the molecule represented by the following structural formula (4), methyl methacrylate 70 parts and toluene 200 parts are used. Introduced into the equipped flask, 90 ℃ in nitrogen atmosphere
And reacted for 20 hours. The same procedure as the production method described in Example 2 was followed to obtain 75 parts of a white polymer.

When the physical properties of the white polymer thus obtained were measured in the same manner as in Example 1, the following characteristic values were exhibited and it was confirmed to be a methyl methacrylate-dimethylsiloxane block copolymer. _n 5.81 × 10 ⁴ _w 1.59 × 10 ⁴ _w / _n 2.75 Nuclear magnetic resonance spectrum: 0.08 ppm (Si-CH ₃ ) 3.67 ppm (-COOCH ₃ ) Si-weight ratio: 33% Example 7 Used in Example 5 The same polydimethylsiloxane compound (30 parts), vinyl acetate (70 parts), and toluene (200 parts) were introduced into a flask equipped with a reflux condenser and a stirrer, and reacted at 90 ° C. for 20 hours in a nitrogen atmosphere. After completion of the reaction, the contents of the flask were put into about 15 times the amount of methanol to precipitate the polymer, and the polymer was obtained by filtration. Then, it was dried under reduced pressure to obtain 72 parts of a white polymer.

Physical properties of the light yellow polymer thus obtained were measured in the same manner as in Example 1, and the following characteristic values were obtained.
It was confirmed to be a vinyl acetate-dimethylsiloxane block copolymer. _n 7.11 × 10 ⁴ _w 2.25 × 10 ⁵ _w / _n 3.16 Nuclear magnetic resonance spectrum: 0.08 ppm (Si-CH ₃ ) 2.11 ppm (methyl group of vinyl acetate) Si-weight ratio: 34% Comparative Example 1 In Example 1 In place of the polydimethylsiloxane compound having an average molecular weight of 10,000 used, 46 parts of polydimethylsiloxane differing only in the average molecular weight from 1500 and 14 parts of lauroyl peroxide (purity 99%) were used, and the production method described in Example 1 was used. The same procedure was followed to obtain 40 parts of white polymer.

When the nuclear magnetic resonance absorption spectrum of the white polymer thus obtained was measured, the absorption of the methyl group of dimethylsiloxane (0.08 ppm) was confirmed, but the absorption of the benzene ring of styrene (6.56 ppm and 7.03 ppm) was confirmed. No
No styrene-dimethylsiloxane block copolymer was obtained.

Comparative Example 2 Instead of the polydimethylsiloxane compound having an average molecular weight of 10,000 used in Example 2, 46 parts of polydimethylsiloxane having a different average molecular weight of 1500 and 14 parts of lauroyl peroxide (purity 99%) were used. 40 parts of a white polymer was obtained by operating in the same manner as the production method described in 2.

When the nuclear magnetic resonance absorption spectrum of the white polymer thus obtained was measured, the absorption of the methyl group of dimethylsiloxane (0.08 ppm) was confirmed, but the absorption of the methyl ester group of methyl methacrylate (3.67 ppm) was not confirmed. , Methylmethacrylate-dimethylsiloxane block copolymer was not obtained.

Comparative Example 3 An example except that, instead of the polydimethylsiloxane compound having an average molecular weight of 15100 used in Example 7, 27 parts of polydimethylsiloxane having only an average molecular weight different from 4800 and 2 parts of benzoyl peroxide (purity 99%) were used. 22 parts of white polymer was obtained by operating in the same manner as the manufacturing method described in 7.

When the nuclear magnetic resonance absorption spectrum of the white polymer thus obtained was measured, the absorption of the methyl group of dimethylsiloxane (0.08 ppm) was confirmed, but the absorption of the methyl group of vinyl acetate (2.11 ppm) was not confirmed, Vinyl acetate
No dimethylsiloxane block copolymer was obtained.

Claims (1)

[Claims] 1. In polymerizing a vinyl type monomer, the following structural formula (A): (In the formula, R ₁ represents an alkyl group or an aryl group having 1 to 15 carbon atoms. Further, R represents an alkylene group having 3 to 10 carbon atoms or Represents a group, R ₂ represents an alkylene group having 1 to 15 carbon atoms or a phenylene group, and R ₃ represents an alkylene group having 3 to 10 carbon atoms or a — (CH ₂ ) ₂ O (CH ₂ ) ₃ — group. Also, m is 10 to 200
And x is 2 to 10), and a polydimethylsiloxane compound having a diacyl-type peroxy group in the molecule is used as a radical polymerization initiator, the method for producing a dimethylsiloxane block copolymer.