JPH0617479B2 - 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, page 1, (1970
(1989) 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, page 599 (1984), it was 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 "prepolymer"). 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 according to the present invention, when polymerizing a vinyl-type monomer, a polydimethylsiloxane compound having a peroxyester group at both ends of a molecule represented by the following structural formula (A) is radicalized. It is characterized by being used as a polymerization initiator.

(In the formula, R ₁ represents a tertiary alkyl group having 4 to 8 carbon atoms. Further, R ₂ represents Or Group, R ₃ is - (CH _{2) 3} - represents a group - group or a _{- (CH 2) 2 0 (} CH 2) 3. Further, m is 1 to 3 and n is 10 to 200. ) 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 ₁ 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 1 to 3 and n is 10
~ 200. If m is out of this range, it is difficult to obtain raw materials and synthesis is difficult. When n> 200, the molecular weight becomes too large and synthesis is difficult, and when n <10, the dimethylsiloxane component is too small to exhibit its characteristics. The compound represented by the structural formula (A) can obtain a half-life of 10 hours at a temperature in the range of about 100 to 110 ° 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, for example, by the following method.

For example, in the case of producing from a bifunctional hydroxyl-terminated polydimethylsiloxane and an aromatic dibasic acid chloride, first, as shown in the following reaction formula, a bifunctional hydroxyl-terminated polydimethylsiloxane (I) and an aromatic dibasic acid are first prepared. The chloride (II) is subjected to a dehydrochlorination reaction in the presence of an organic solvent such as benzene and toluene under a stream of dry nitrogen to produce a polydimethylsiloxane (III) having a chloroacyl group in the molecule.

The reaction temperature of the above reaction is preferably 40 to 90 ° C, and the reaction time is preferably 3 to 5 hours. Examples of (II) include phthal chloride, isophthal chloride, and terephthal chloride.

Then, according to a conventional method, this (III) is an organic hydroperoxide (IV) and a base such as pyridine and benzene,
By performing a dehydrochlorination reaction in the presence of an organic solvent such as toluene or xylene, a polydimethylsiloxane compound (A) having an aromatic peroxyester group at both ends of the molecule is produced as shown in the following reaction formula.

(Here, R ₁ represents a tertiary alkyl group having 4 to 8 carbon atoms, R ₂ represents a phenylene group, R ₃ represents a-(CH ₂ ) ₃ -group or-(CH ₂ ) ₂₀ (CH ₂ ) ₃ -.. represents the group also, n represents 10 to 200) Here, as the acid component, if prepared using aromatic Tashio (3 or more) groups of the acid anhydride chloride, first two A functional hydroxyl-terminated polydimethylsiloxane and an aromatic polybasic acid anhydride chloride are subjected to dehydrochlorination reaction in the presence of an organic solvent such as benzene or toluene under a dry nitrogen stream to have a polybasic acid anhydride group in the molecule. The polydimethylsiloxane compound (A) can also be produced via polydimethylsiloxane.

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 various dimethylsiloxane block copolymers can be produced by an extremely simple operation. Yes, it has an extremely high industrial value. 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. sex,
The properties of polydimethylsiloxane such as 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, 33.2 g of α, ω-bis- (2-hydroxy) ethoxypropylpolydimethylsiloxane having an average molecular weight of 1660 and 8.1 g of isophthalic acid chloride (purity 99%) And 20 ml of benzene were introduced. While blowing dry nitrogen into it, the reaction temperature is 80 ℃.
And reacted 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 benzene. Thus, 39.0 g (purity 99%, yield 97%) of polydimethylsiloxane having a chloroacyl group in the molecule was obtained as a colorless transparent liquid.

Next, 5.6 g of tertiary butyl hydroperoxide (purity 97%), pyridine (purity 99%) 4.8 g, and xylene 20 ml were introduced into a four-necked flask equipped with an agitator. To this, 39.0 g of polydimethylsiloxane having a chloroacyl group in the molecule obtained by the above reaction was added little by little at 5 to 10 ° C. with stirring. Then, after stirring at 20 to 25 ° C for 5 hours, pyridine hydrochloride was separated by filtration. The obtained liquid material was washed twice with saturated saline and then dried over anhydrous magnesium sulfate. After separating anhydrous magnesium sulfate by filtration, excess tertiary butyl hydroperoxide, pyridine, and xylene were removed under vacuum to obtain 41.1 g.
To obtain a colorless transparent liquid.

For the colorless 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] measurement), UV absorption spectrum (JASCO UVIDEC-505)
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). The characteristic values were shown, and the compound was confirmed to be a polydimethylsiloxane compound having an aromatic peroxyester group at both ends of the molecule represented by the structural formula (1).

Active oxygen amount: 1.46% Temperature for obtaining half-life of 10 hours of peroxy bond: 104.2 ℃ Number average molecular weight: 2100 Ultraviolet absorption spectrum: 228nm (ε = 15700) 272nm (ε = 1200) Infrared absorption spectrum: 1770cm ^-1 (peroxyester C = O bond of the group) 1100-1030cm ^-1 (Si-O-Si bond) 1270cm ^-1 (Si-CH ₃ bond) Nuclear magnetic resonance absorption spectrum: 0.08ppm 49H (a) 0.45ppm 2H (b) 1.40ppm 9H (c) 1.60ppm 2H (d) 3.50ppm 4H (e) 4.50ppm 2H (f) 7.50 ~ 8.60ppm 4H (g) Example 1 The following structural formula (1) having an average molecular weight of 2100 and an active oxygen content of 1.46%: : Polydimethylsiloxane compound having a peroxy ester group at both ends of the molecule represented by 60 parts, styrene 40 parts,
Then, 200 parts of xylene was introduced into a flask equipped with a reflux condenser and a stirrer, and reacted at 120 ° 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, then poured into about 10-fold amount of methanol to precipitate a polymer, filtered, and dried under reduced pressure to obtain 77 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 FK-90Q FT-NMR equipment) showed the following characteristic values, styrene-dimethylsiloxane block It was confirmed to be a copolymer.

Number average molecular weight (hereinafter referred to as _n ) 5.54 × 10 ³ Weight average molecular weight (hereinafter referred to as _w ) 1.17 × 10 ⁴ Dispersion ratio (hereinafter referred to as _w / _n ) 2.11 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 dimethyl siloxane 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, methyl methacrylate 40 parts and xylene 200 parts were introduced into a flask equipped with a reflux condenser and a stirrer, and reacted at 120 ° 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 is concentrated to about one-third and then poured into about 10-fold amount of methanol to precipitate a block copolymer, which is then filtered and dried under reduced pressure.
64 parts of a pale yellow polymer was obtained.

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 8.12 × 10 ³ _w 1.78 × 10 ⁴ _w / _n 2.19 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 : 67% Example 3 The following structural formula (2) having an average molecular weight of 7100 and an active oxygen content of 0.85%: Polydimethylsiloxane compound having a peroxyester group at both ends of the molecule represented by 30 parts, styrene 70 parts,
Then, 200 parts of xylene was introduced into a flask equipped with a reflux condenser and a stirrer, and reacted at 115 ° C. for 30 hours in a nitrogen atmosphere.

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 1.52 × 10 ⁴ _w 3.59 × 10 ⁴ _w / _n 2.36 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 average 30 parts of a polydimethylsiloxane compound having a molecular weight of 7300 and an active oxygen content of 0.81% and having a peroxyester group at both ends of a molecule represented by the following structural formula (3), 70 parts of methyl methacrylate, and 200 parts of xylene are refluxed and a stirrer In a flask equipped with a
The reaction was carried out at 115 ° C for 20 hours.

Then, the same operation as in the production method described in Example 2 was repeated to obtain 69 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 2.88 × 10 ⁴ _w 7.34 × 10 ⁴ _w / _n 2.55 Nuclear magnetic resonance spectrum: 0.08 ppm (Si-CH ₃ ) 3.67 ppm (-COOCH ₃ ) Si-weight ratio: 36% Example 5 Average molecular weight 4300 and active oxygen 50 parts of a polydimethylsiloxane compound having a peroxyester group at both ends of a molecule represented by the following structural formula (4) in an amount of 2.10%, styrene
50 parts and 200 parts of xylene were introduced into a flask equipped with a reflux condenser and a stirrer.

Then, 80 parts of a pale yellow polymer was 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 9.75 × 10 ³ _w 2.20 × 10 ⁴ _w / _n 2.26 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 6 Implementation 50 parts of the same polydimethylsiloxane compound used in Example 5, 50 parts of methyl methacrylate, and 200 parts of xylene were introduced into a flask equipped with a reflux condenser and a stirrer, and reacted at 105 ° C. for 24 hours in a nitrogen atmosphere. The same procedure as in the production method described in Example 2 was followed to obtain 66 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 1.89 × 10 ⁴ _w 4.54 × 10 ⁴ _w / _n 2.40 Nuclear magnetic resonance spectrum: 0.08 ppm (Si-CH ₃ ) 3.67 ppm (-COOCH ₃ ) Si-weight ratio: 57% Example 7 Average molecular weight 3900 and active oxygen In a flask equipped with a reflux condenser and a stirrer, 50 parts of a polydimethylsiloxane compound having a peroxyester group at both ends of a molecule represented by the following structural formula (5) in an amount of 0.78%, 50 parts of vinyl acetate, and 200 parts of toluene were placed. Introduce, 30 at 110 ℃ in nitrogen atmosphere
Reacted for hours. After completion of the reaction, the content of the flask was put into about 15 times the 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 vinyl acetate-dimethylsiloxane block copolymer. _n 2.18 × 10 ⁴ _w 5.84 × 10 ⁴ _w / _n 2.68 Nuclear magnetic resonance spectrum: 0.08 ppm (Si-CH ₃ ) 2.11 ppm (methyl group of vinyl acetate) Si-weight ratio: 61% Comparative Example 1 In Example 1 Example 1 was repeated except that instead of the polydimethylsiloxane compound having an average molecular weight of 2100 used, 45 parts of polydimethylsiloxane differing only in the average molecular weight from 1600 and 12 parts of tert-butylperoxybenzoate (purity 96%) were used. A white polymer (40 parts) was obtained by the operation similar to the production method described in (1) above.

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 In place of the polydimethylsiloxane compound having an average molecular weight of 2100 used in Example 2, 45 parts of polydimethylsiloxane having only an average molecular weight different from 1600 and 12 parts of tert-butylperoxybenzoate (96% purity) were used. Was operated in the same manner as in the production method described in Example 2 to obtain 40 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 ester group of methyl methacrylate (3.67 ppm) was not confirmed. , Methylmethacrylate-dimethylsiloxane block copolymer was not obtained.

Comparative Example 3 Instead of the polydimethylsiloxane compound having an average molecular weight of 3900 used in Example 7, 41 parts of polydimethylsiloxane having only an average molecular weight of 3200 and 1,1,3,3-tetramethylbutylperoxybenzoate (purity 93 %) 8
30 parts of a white polymer was obtained by operating in the same manner as in the production method described in Example 7 except that parts 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 group of vinyl acetate (2.11 ppm) was not confirmed, No vinyl acetate-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 a tertiary alkyl group having 4 to 8 carbon atoms. Further, R ₂ represents Or Group, R ₃ is - (CH _{2) 3} - represents a group - group or a _{- (CH 2) 2 0 (} CH 2) 3. Further, m is 1 to 3 and n is 10 to 200). A dimethylsiloxane system characterized by using a polydimethylsiloxane compound having a peroxyester group at both ends of a molecule represented by A method for producing a block copolymer.