JPH0617478B2 - 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.

The method for producing a dimethylsiloxane block copolymer of the present invention is a method of polymerizing a vinyl-type monomer by radically converting a polydimethylsiloxane compound having a peroxyester group at both ends of a molecule represented by the following structural formula (A). It is characterized by being used as a polymerization initiator.

(In the formula, R represents a tertiary alkyl group having 4 to 8 carbon atoms, m is 10 to 200, and n is 3 to 10).

The present invention will be described in more detail below.

The polydimethylsiloxane compound having peroxyester groups at both ends of the molecule used in the present invention is represented by the above structural formula (A). R in the formula is a tertiary alkyl group having 4 to 8 carbon atoms. When the number of carbon atoms is 9 or more, it is difficult to obtain the raw material and the synthesis is difficult. Also, m is 10 to 200 and n is 3
Is ~ 10. When m is> 200, the molecular weight becomes too large and synthesis is difficult, and when m <10, the dimethylsiloxane component is too small to exhibit its characteristics. If n is out of this range, it is difficult to obtain raw materials and synthesis is 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 90 to 100 ° 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 and is easily dissolved in benzene, toluene, xylene, hexane and the like.

The polydimethylsiloxane compound represented by the structural formula (A) used in the present invention can be produced by the following method.

That is, as shown in the following reaction formula, first, a bifunctional carboxyl-terminated polydimethylsiloxane (I) is subjected to a chlorination reaction in the presence of a chlorinating agent (II) in a dry nitrogen stream by a conventional method to give a chloroacyl group in the molecule. To produce polydimethylsiloxane (III).

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 a conventional method, dehydrochlorination of this (III) and organic hydroperoxide (IV) in the presence of a base such as pyridine is carried out, and as shown by the following reaction formula, a polyoxyester having a peroxyester group at both ends of the molecule is obtained. A dimethylsiloxane compound (A) is produced.

(In the formula, R represents a tertiary alkyl group having 4 to 8 carbon atoms, m is 10 to 200, and n is 3 to 10.) The above reaction is almost the same as in the known peroxy ester. It does not matter under the reaction conditions. The reaction temperature is 0 to 40 ° C, preferably 20 to 30 ° C, and the reaction time is 3 to 8 hours, preferably 5 to 7 hours. The molar ratio of (III) and (IV) is 1:
It is 1 to 4, preferably 1: 2 to 3. The ratio of the functional group concentration of (III) to the base is 1: 1 to 4, preferably 1: 2.
It is 3. 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.

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 peroxyester group at both ends of the molecule and the vinyl type monomer is generally 10 to 90 parts by weight of the polydimethylsiloxane compound having a peroxyester group at both ends of the molecule,
The vinyl type monomer is preferably 90 to 10 parts by weight, and the ratio can be widely selected depending on the intended use. Less than 10 parts by weight of polydimethylsiloxane compound and 90
If the amount is more than the amount 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 60 to 160 ° C, preferably 80 to 140 ° C. When the reaction temperature is lower than 60 ° C, the reaction time becomes too long, which is industrially unsuitable. Also, 16
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 (5) 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, 171 g of α, ω-bis-10-carboxydecylpolydimethylsiloxane having an average molecular weight of 1900 and thionyl chloride (purity 99
%) 19.6 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 1 at 40-45 ℃
Suction with a water flow pump for 10 to 20 mmHg to maintain a reduced pressure,
The remaining thionyl chloride was removed. Thus, 170 g of polydimethylsiloxane having a chloroacyl group in the molecule (purity 99.5%, yield 97.1%) was obtained as a yellow transparent liquid.

Then, 26.5 g of tertiary butyl hydroperoxide (purity 96.5%), pyridine (purity 99%) 22.7 g, and xylene 82 g were introduced into a four-necked flask equipped with an agitator.
To this, 170 g of polydimethylsiloxane having a chloroacyl group in the molecule obtained by the above reaction was added little by little under stirring at 5 to 10 ° C. Then, after stirring at 20 to 25 ° C for 5 hours, the produced pyridine hydrochloride was separated by filtration. The obtained liquid material was washed twice with saturated saline and then dried over anhydrous magnesium sulfate. Further, anhydrous magnesium sulfate was separated by filtration, and then excess tertiary butyl hydroperoxide, pyridine, and xylene were removed under vacuum to obtain 180 g of a yellow transparent liquid.

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

Active oxygen amount: 1.57% Temperature for obtaining half-life of peroxy bond 10 hours: 96.3 ° C Number average molecular weight: 2000 Infrared absorption spectrum: 1790cm ^-1 (C = O bond of peroxyester group) 1100 to 1030cm ^-1 (Si-O -Si bond) 1270cm ^-1 (Si-CH ₃ bond) Nuclear magnetic resonance absorption spectrum: 0.08ppm 507H (a) 0.45ppm 20H (b) 1.25ppm 140H (c) 1.32ppm 90H (d) 1.60ppm 20H (e) 2.35ppm 20H (f) Example 1. The following structural formula (1) having an average molecular weight of 2000 and an active oxygen content of 1.57%: Polydimethylsiloxane compound having a peroxy ester group at both ends of the molecule represented by 60 parts, styrene 40 parts,
Then, 200 parts of toluene was introduced into a flask equipped with a reflux condenser and a stirrer, and reacted at 110 ° C. for 20 hours in a nitrogen atmosphere.

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 75 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 with JEOL FK-90Q FT-NMR equipment)
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 ) 4.15 × 10 ³ Weight average molecular weight (hereinafter referred to as _w ) 8.51 × 10 ³ Dispersion ratio (hereinafter referred to as _w / _n ) 2.05 Nuclear magnetic resonance absorption spectrum: 0.08 ppm [methyl dimethylsiloxane] Group (hereinafter Si-CH ₃
)], 6.56ppm and 7.03ppm (benzene ring of styrene (-C
₆ H ₅ )] Weight ratio of dimethylsiloxane segment in polymer (hereinafter referred to as Si-weight ratio): 64% Example 2. 60 parts of the same polydimethylsiloxane compound as used in Example 1, 40 parts of methyl methacrylate, and 200 parts of toluene were introduced into a flask equipped with a reflux condenser and a stirrer, and reacted at 110 ° 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. Next, the filtrate was concentrated to about one-third and then poured into about 10 times amount of methanol to precipitate a polymer, which was filtered and dried under reduced pressure to obtain 62 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 6.58 × 10 ³ _w 1.38 × 10 ⁴ _w / _n 2.10 Nuclear magnetic resonance spectrum: 0.08 ppm (Si-CH ₃ ) 3.67 ppm [Methyl methacrylate methyl ester group (hereinafter referred to as -COOCH ₃ group)] Si-weight ratio : 68% Example 3 The following structural formula (2) having an average molecular weight of 6600 and an active oxygen content of 0.45%: Polydimethylsiloxane compound having a peroxyester group at both ends of the molecule represented by 30 parts, styrene 70 parts,
And 200 parts of toluene were introduced into a flask equipped with a reflux condenser and a stirrer.

Then, the same operation as in the production method described in Example 1 was carried out to obtain 83 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 9.57 × 10 ³ _w 2.15 × 10 ⁴ _w / _n 2.25 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 4. 30 parts of the same polydimethylsiloxane compound as shown in Example 3, 70 parts of methyl methacrylate, and toluene
200 parts were introduced into a flask equipped with a reflux condenser and stirrer.

Then, 68 parts of a white polymer was obtained by operating in the same manner as in the production method described in Example 2.

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 1.86 × 10 ⁴ _w 4.52 × 10 ⁴ _w / _n 2.43 Nuclear magnetic resonance spectrum: 0.08 ppm (Si-CH ₃ ) 3.67 ppm (-COOCH ₃ ) Si-weight ratio: 36% Example 5. The following structural formula (3) having an average molecular weight of 3300 and an active oxygen content of 0.91%: 50 parts of a polydimethylsiloxane compound having a peroxyester group at both ends of the molecule represented by, styrene 50 parts,
And 200 parts of toluene was introduced into a flask equipped with a reflux condenser and a stirrer, and reacted at 105 ° C. for 30 hours in a nitrogen atmosphere.

Thereafter, the same procedure as in the production method described in Example 1 was followed to obtain 77 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 styrene-dimethylsiloxane block copolymer. _n 6.78 × 10 ³ _w 1.44 × 10 ⁴ _w / _n 2.13 Nuclear magnetic resonance spectrum: 0.08 ppm (Si-CH ₃ ) 6.56 ppm and 7.03 ppm (-C ₆ H ₅ ) Si-weight ratio: 53% Example 6. The following structural formula (4) having an average molecular weight of 3400 and an active oxygen content of 0.89%: Into a flask equipped with a reflux condenser and a stirrer was introduced 50 parts of a polydimethylsiloxane compound having a peroxyester group at both ends of a molecule represented by, 50 parts of methylmethacrylate, and 200 parts of toluene, and 105 ° C in a nitrogen atmosphere.
And reacted for 24 hours.

The same procedure as in Example 2 was followed to obtain 64 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 1.13 × 10 ⁴ _w 2.55 × 10 ⁴ _w / _n 2.25 Nuclear magnetic resonance spectrum: 0.08 ppm (Si-CH ₃ ) 3.67 ppm (-COOCH ₃ ) Si-weight ratio: 59% Example 7. The following structural formula (5) having an average molecular weight of 3200 and an active oxygen content of 0.95%: 50 parts of polydimethylsiloxane compound having peroxyester groups at both ends of the molecule represented by
And 200 parts of toluene were introduced into a flask equipped with a reflux condenser and a stirrer, and reacted at 110 ° 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 methanol to precipitate a polymer. This was filtered and dried under reduced pressure to obtain 61 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 vinyl acetate-dimethylsiloxane block copolymer. _n 1.67 × 10 ⁴ _w 4.43 × 10 ⁴ _w / _n 2.65 Nuclear magnetic resonance spectrum: 0.08 ppm (Si-CH ₃ ) 2.11 ppm (methyl group of vinyl acetate) Si-weight ratio: 62% Comparative Example 1. The average molecular weight 2000 and the amount of active oxygen used in Example 1 were 1.57.
Instead of the polydimethylsiloxane compound having a peroxyester group at both ends of the molecule, the average molecular weight is 1500.
A white polymer (40 parts) was obtained in the same manner as in the production method described in Example 1, except that 45 parts of polydimethylsiloxane and 18 parts of tertiary butyl peroxylaurate (purity 90%) were used.

When the nuclear magnetic resonance absorption spectrum of the thus obtained white polymer 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 styrene-dimethylsiloxane block copolymer was obtained.

Comparative example 2. The average molecular weight 2000 and the amount of active oxygen used in Example 2 were 1.57.
Instead of the polydimethylsiloxane compound having a peroxyester group at both ends of the molecule, the average molecular weight is 1500.
A white polymer (40 parts) was obtained by the same procedure as the production method described in Example 2 except that 45 parts of polydimethylsiloxane and 18 parts of tertiary butyl peroxylaurate (purity 90%) were used.

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. The production method described in Example 7 except that 47 parts of polydimethylsiloxane having an average molecular weight of 3000 and 5 parts of tertiary butyl peroxyvalerate (purity 94%) were used in place of the polydimethylsiloxane compound used in Example 7. The same procedure was followed to obtain 37 parts of a 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 methyl group of vinyl acetate (2.11 ppm) was not confirmed, No vinyl acetate-dimethylsiloxane block copolymer was obtained.

Claims (1)

[Claims] 1. When polymerizing a vinyl type monomer, the following structural formula (A): (Wherein R represents a tertiary alkyl group having 4 to 8 carbon atoms, m is 10 to 200, and n is 3 to 10), and polydimethyl having a peroxyester group at both ends. A method for producing a dimethylsiloxane block copolymer, which comprises using a siloxane compound as a radical polymerization initiator.