JPS6392628A - Production of dimethylsiloxane graft polymer - Google Patents

Abstract

PURPOSE:To obtain a dimethylsiloxane graft polymer industrially in good yields by a radical polymerization process, by using a specified polydimethylsiloxane compound as a radical polymerization initiator in polymerizing a vinyl monomer. CONSTITUTION:The following compound A or B is used as a radical polymerization initiator in polymerizing a vinyl monomer: [A] a polydimethylsiloxane compound having peroxyester groups in side chains, represented by formula I (wherein R1 is a 4-8C tert. alkyl group, m is 10-200, n is 3-10, and l is 1-15) and [B] a polydimethylsiloxane compound having a diacyl type peroxy group in the molecule, represented by formula II (wherein m is 10-200 and n is 3-10). The ratio of said component A or B to the vinyl monomer is preferably 10-90:90-10 (by weight).

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing a polymer compound, and particularly to a method for producing a dimethylsiloxane-based graft polymer.

(Prior Art) Several methods have been proposed as methods for producing siloxane-based graft polymers.

For example, Japanese Patent Publication No. 32-6896, Japanese Patent Publication No. 47-1
No. 6199 and Japanese Unexamined Patent Publication No. 48-28389 disclose a method of forming an active group by abstracting hydrogen from a lower alkyl group bonded to a silicon atom of siloxane, and grafting an organic polymer thereto (hereinafter referred to as hydrogen of siloxane). (abbreviated as the pull-out method) has been disclosed.

Also, Japanese Patent Publication No. 46-9355, Japanese Patent Publication No. 52-13
Publication No. 5391 discloses a method in which a siloxane having an active group is produced in advance and an organic polymer is grafted onto the active group (hereinafter abbreviated as a method using a siloxane having an active group).

Furthermore, in JP-A-58-167606,
A method of radically copolymerizing a siloxane having a radically polymerizable unsaturated group and a vinyl monomer (hereinafter abbreviated as a method using a siloxane having a radically polymerizable unsaturated group) is disclosed.

(Problems to be Solved by the Invention) However, the conventional methods include several problems as shown below.

1) In the hydrogen abstraction method of siloxane, a hydrogen abstraction reaction from a lower alkyl group bonded to a silicon atom is an essential condition for producing a graft polymer, and the commonly used method involves siloxane and grafting to it. This method involves heating and reacting a monomer capable of forming a polymer with an organic peroxide. However, the ease with which siloxane abstracts hydrogen varies depending on the type of peroxide and the reaction temperature, and the molecular weight of the organic polymer to be grafted is also affected by the reaction temperature. Therefore, it is difficult to effectively control the effects of both.
It is not possible to obtain a graft polymer with a well-defined structure.

2) In the method using siloxane having active groups,
A method for obtaining a siloxane-based graft polymer by reacting a siloxane having an active group with a living polymer obtained by anionic polymerization (Japanese Patent Publication No. 46-9355)
, and a method of synthesizing a polysiloxane polyester containing maleic acid in the main chain, mixing it with maleic acid and an electron-donating monomer that easily forms a charge transfer complex, and grafting it to obtain a siloxane-based graft polymer ( Japanese Patent Publication No. 52-135391). However, the former requires the use of anionic polymerization and is therefore unsuitable for industrial use, while the latter has limitations on the monomers that can be used in the reaction.

3) In the method using a siloxane having a radically polymerizable unsaturated group, a graft polymer is obtained by radically copolymerizing an acrylic modified siloxane and a vinyl monomer. However, the reactivity of acrylic-modified siloxane is easily affected by the molecular weight of the polymer, and the polymerizability decreases after the reaction. For this reason, the molecular weight and yield of the graft polymer will be affected.

In order to industrially produce a siloxane-based graft polymer, it is necessary that a radical polymerization method can be applied and that the graft polymer can be obtained in high yield.

An object of the present invention is to solve these problems and provide a method for producing a dimethylsiloxane-based graft polymer that can be obtained industrially in high yield by a radical polymerization method.

(Means for Solving the Problems) The objects of the present invention are achieved by a method for producing a dimethylsiloxane-based graft polymer.

In the method for producing a dimethylsiloxane graft polymer according to the present invention, when polymerizing a vinyl monomer, the following structural formula (A): C0OR+ 0 -...- (A) (wherein, R8 has 4 to 4 carbon atoms) represents a tertiary alkyl group of 8. Also, m is 10 to 200, n is 3 to 10,
l is 1-15. ) A polydimethylsiloxane compound having a peroxyester group in the side chain of the molecule, or a polydimethylsiloxane compound having the following structural formula (B
): and 5゜1 ・・・・・・・−(B)c=.

(In the formula, m is 10 to 200 and n is 3 to 10.)
This is a method for producing a dimethylsiloxane-based graft polymer, characterized in that a polydimethylsiloxane compound having a diacyl type peroxy group in the molecule represented by is used as a radical polymerization initiator.

The present invention will be explained in more detail below.

The polydimethylsiloxane compound having a peroxyester group in the side chain of the molecule used in the present invention has a molecular weight of about 90 to 100%.
℃, and polydimethylsiloxane compounds having diacyl peroxy groups in the molecule have a half-life of 10 hours in the range of about 60 to 65℃, and as a component of the copolymer. It is a polydimethylsiloxane compound with radical polymerization properties that can be used.

In the above formula, R3 represents a tertiary alkyl group having 4 to 8 carbon atoms, but when the number of carbon atoms is 9 or more, it is difficult to obtain raw materials.
Difficult to synthesize. In addition, m is 10 to 200,
When the value of m exceeds 200, the molecular weight becomes too large and synthesis is difficult, and when the value of m is 9 or less, it is difficult to express the properties of the siloxane component. Furthermore, n is 3 to 10 and l is 1 to 15, but outside these ranges it is difficult to obtain raw materials and synthesis is difficult.

Further, these polydimethylsiloxane compounds have a solubility equivalent to that of ordinary polydimethylsiloxane, and are easily dissolved in benzene, toluene, xylene, hexane, and the like.

Next, vinyl-type monobonds that can be used in the present invention include styrene, methylstyrene, diphenylethylene, ethylstyrene, dimethylstyrene, vinylnaphthalene, vinylphenanthrene, vinylmesitylene, 3.4.6-drimethylstyrene, l- Hydrocarbon compounds such as vinyl-2-ethyl acetylene, butadiene, isoprene, piperylene, etc.: chlorstyrene, methoxystyrene, bromustyrene, cyanostyrene, fluorostyrene, dichlorostyrene, N,N-dimethylaminostyrene, nitrostyrene, chlorostyrene Styrene derivatives such as methylstyrene, trifluorostyrene, trifluoromethylstyrene, aminostyrene; acrylonitrile, methacrylonitrile, α-
Acrylonitrile attractants such as acetoxyacrylonitrile; acrylic acid, methacrylic acid; acrylic acid esters such as methyl acrylate, lauryl acrylate, chloromethyl acrylate, and ethyl acetoxyacrylate; cyclohexyl methacrylate, dimethylamine ethyl methacrylate, and methacrylate are glycidyl , methacrylic acid esters such as tetrahydrofurfuryl methacrylate and hydroxyethyl methacrylate; vinylitine chloride, vinylidene bromide,
Vinylidene compounds such as vinylidene cyanide; 3'MR acrylamide compounds such as acrylamide, methacrylamide, N-butoxymethylacrylamide, N-phenylacrylamide, diacetone acrylamide, N,N-dimethylaminoethyl acrylamide; vinyl acetate, vinyl butyrate , fatty acid vinyl derivatives such as vinyl caprate;
Furthermore, N-vinylsuccinimide, N-vinylpyrrolidone, N-vinylphthalimide, N-vinylcarbazole, vinylfuran, 2-vinylbenzofuran, vinylthiophene, vinylthiazole, methylvinylimidazole, vinylpyrazole, vinyloxazolidone, vinylthiazole, There are heterocyclic vinyl compounds such as vinyltetrazole, vinylpyridine, methylvinylpyridine, 2,4-dimethyl-6-vinyltriazine, and vinylquinoline.

The vinyl monomer can be used alone or in combination of two or more types.

A polydimethylsiloxane compound having a peroxy group in the molecule, such as a polydimethylsiloxane compound having a peroxyester group in the side chain of the molecule or a polydimethylsiloxane compound having a diacyl type peroxy group in the molecule, and a vinyl type monomer. The composition ratio is generally 1:1 for a polydimethylsiloxane compound having a peroxy group in the molecule.
The vinyl type monomer is preferably used in an amount of 90 to 10 parts by weight relative to 0 to 90 parts by weight, and the ratio can be selected within a wide range depending on the intended use. Polydimethylsiloxane compound is 1
If the amount is less than 1 part by weight or more than 90 parts by weight, characteristics as a graft polymer cannot be expressed.

Further, as the radical polymerization method, any method such as solution polymerization method, bulk polymerization method, emulsion polymerization method, or suspension polymerization method can be used.

The reaction temperature for radical polymerization is 30 to 160"C, preferably 50 to 140C. If the reaction temperature is lower than 30"C, the reaction time becomes too long and is industrially inappropriate. Furthermore, if the temperature is higher than 160°C, the peroxy group will decompose instantly and the reaction will not proceed well.

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

As described above, when the method for producing a dimethylsiloxane-based graft polymer according to the present invention is used, a dimethylsiloxane-based graft polymer can be obtained in a one-step reaction. Note that the obtained dimethylsiloxane-based graft polymer contains a homopolymer of vinyl monomers, but a highly pure graft polymer can be separated by reprecipitation or solvent extraction using an appropriate solvent. be able to.

(Effects of the Invention) The method for producing a dimethylsiloxane-based graft polymer according to the present invention enables production of various dimethylsiloxane-based graft polymers by extremely slow operations,
Its industrial value is extremely high.

Furthermore, the dimethylsiloxane-based graft polymer obtained by the present invention can be used as a raw material or surface modifier for sealants, various plastic films and molded products, fibers, rubber, paints, adhesives, etc., and has excellent water resistance, heat resistance, It can provide the properties of polydimethylsiloxane such as weather resistance.

(Example) Next, the present invention will be explained with reference to Examples and Comparative Examples.

Example 1 30 parts of a polydimethylsiloxane compound having a peroxyester group in the side chain of the molecule represented by the following structural formula (1) with an average molecular weight of 7400 and an active oxygen qo of 79%, 70 parts of styrene, and 200 parts of toluene were introduced into a flask equipped with a reflux condenser and a stirrer, and heated at 110°C in a nitrogen atmosphere for 2 hours.
The reaction was allowed to proceed for 0 hours. After the reaction is complete, the contents of the flask are reduced to about 15%
The mixture was poured into twice the amount of n-hexane to precipitate styrene homopolymer, which was removed by filtration. Next, the filtrate was cyclocondensed to about one-third its volume, and then poured into about 10 times the amount of methanol to precipitate a polymer, which was then filtered to obtain a polymer.

After drying under reduced pressure, 84 parts of a white polymer was obtained.

Regarding the white polymer thus obtained, the average molecular weight [
Toyo Soda Kogyo high performance liquid chromatography CPU etc.
: ) ILc-802A, DETECTOR:
Rl-8000)] and nuclear magnetic resonance absorption spectrum (measured with a JEOL FX-90Q FT-NMR apparatus), it showed the following characteristic values and was confirmed to be a styrene-dimethylsiloxane graft polymer.

Number average molecular weight (hereinafter expressed as ■) 1.33 x 10 parts Weight average molecular weight (hereinafter expressed as ■) 2.95X10'
Dispersion ratio (hereinafter expressed as ■./M) 2.22 Nuclear magnetic resonance absorption spectrum: o, osppm (Methyl group of dimethylsiloxane (
(hereinafter referred to as 5i-CHs)] 6.56 ppm and 7. O3ppm (benzene ring of styrene (hereinafter expressed as -C6I+ 5)) Weight proportion of dimethylsiloxane segment in the polymer (hereinafter expressed as Si-weight ratio): 32% Example 2 The same polyester as used in Example 1 30 parts of dimethylsiloxane compound, 70 parts of methyl methacrylate, and 200 parts of toluene were introduced into a flask equipped with a reflux condenser and a stirrer, and reacted in a nitrogen atmosphere at 110°C for 20 hours.After the reaction was completed, the contents of the flask were About 15 times the amount of n
- methyl methacrylate homopolymer was precipitated and removed by filtration. The filtrate is then diluted with approx.
After concentrating to 1/2 volume, the mixture was poured into about 10 times the amount of methanol to precipitate the polymer, which was then filtered to obtain a polymer. After drying under reduced pressure, 75 parts of a white polymer was obtained.

When the physical properties of the thus obtained white polymer were measured in the same manner as in Example 1, it showed the characteristic values shown below, and was recognized as a methylmethacdylate-dimethylsiloxane graft polymer (11).

M, 3.25xlO' M, 7.93X10' Mw/M+, 2.44 Nuclear magnetic resonance spectrum: 0, O8ppm (Si-CH3) 3.67ppm (Methyl ester group of methyl methacrylate (hereinafter referred to as -COOCIh group) ] St-weight ratio: 35% Example 3 30 parts of the same polydimethylsiloxane compound used in Example 1, 70 parts of vinyl acetate, and 20 parts of toluene.
0 parts were introduced into a flask equipped with a reflux condenser and a stirrer, and reacted for 20 hours at 110°C in a nitrogen atmosphere. After the reaction was completed, the contents of the flask were poured into about 15 times the amount of methanol to dissolve the vinyl acetate homopolymer, and the precipitated polymer was obtained by filtration. After drying under reduced pressure, 70 parts of a white polymer was obtained.

When the physical properties of the thus obtained white polymer were measured in the same manner as in Example 1, it exhibited the characteristic values shown below, and was confirmed to be a vinyl acetate-dimethylsiloxane graft polymer.

M,,5.32X10' MW 1.44X105 ■,,/πn2.71 Nuclear magnetic resonance spectrum: 0, O8ppm (Si-CH3) 2, llppm (Methyl group of vinyl acetate (hereinafter referred to as VA
It is expressed as c-CH3. )] Si-weight ratio: 38% Example 4 Polydimethyl having a peroxyester group in the side chain of the molecule represented by the following structural formula (2) with an average molecular fit of 1700 and active oxygen of 10.87%: 60 parts of a siloxane compound, 40 parts of Step 1, and 200 parts of toluene were introduced into a flask equipped with reflux cooling and a stirrer, and reacted at 105°C in a nitrogen atmosphere for 30 hours. Thereafter, 72 parts of a white polymer was obtained by operating in the same manner as the production method described in Example 1.

When the physical properties of the thus obtained white polymer were measured in the same manner as in Example 1, it showed the characteristic values shown below, and compared to the styrene-dimethylsiloxane graft polymer and 611
It was LU'd.

Mn7.22
61 (5) Si - weight ratio = 63% Example 5 A peroxyester group was added to the side chain of the molecule represented by the following structural formula (3) with an average molecular weight of 11700 and active oxygen, 10.83%: 60 parts of a polydimethylsiloxane compound, 40 parts of methyl methacrylate, and 200 parts of toluene were introduced, and the mixture was reacted at 105° C. for 24 hours in a nitrogen atmosphere.

Thereafter, 62 parts of a white polymer was obtained by operating in the same manner as the production method described in Example 2.

When the physical properties of the white polymer obtained in this manner were measured in the same manner as in Example 1, it exhibited the characteristic values shown below, and was confirmed to be a methyl methacrylate-dimethylsiloxane graft polymer.

M,, 1.24X10' M, 3.56X10' H-/M, 2.87 nucleus (injection resonance spectrum: 0, O8ppm (Si-CH3) 3.67ppm (-COOCHz) Si-weight ratio: 68% Example 6 60 parts of a polydimethylsiloxane compound having a diacyl type peroxide group in the molecule, represented by the following structural formula (4) with an average molecular weight of 13700 and an active oxygen concentration of ZO,, U%, %, and styrene. 40 parts and 200 parts of benzene were introduced into a flask equipped with a reflux condenser and a stirrer, and reacted at 80°C for 20 hours under a nitrogen atmosphere.The production method described in Example 1 was repeated below. 92 parts of a white polymer was obtained.

When the physical properties of the thus obtained white polymer were measured in the same manner as in Example 1, it exhibited the characteristic values shown below, and was confirmed to be a styrene-dimethylsiloxane graft polymer.

M, 1.13X10'side-2,66X10' side-/π, 2.35 Nuclear magnetic resonance spectrum: 0, O8ppm (Si-C1h) 6.56ppm and 7. O3ppm (-cans)
Si-weight ratio: 61% Example 7 60 parts of the same polydimethylsiloxane compound used in Example 6, 40 parts of methyl methacrylate, and 200 parts of benzene were introduced into a flask equipped with a reflux condenser and a stirrer, and nitrogen The reaction was carried out in an atmosphere of 80"C for 20 hours. The following procedure was carried out in the same manner as described in Example 2 to obtain 87 parts of a white polymer.

When the physical properties of the thus obtained white polymer were measured in the same manner as in Example 1, it exhibited the characteristic values shown below, and was confirmed to be a methyl methacrylate-dimethylsiloxane graft polymer.

M,, 2.32X10' M, 6.17X10' M, /M, 2.66 Nuclear magnetic resonance spectrum: 0, O8ppm (Si-C1h) 3.67ppm (-COOCIh)Si-weight ratio = 63% Example 8 average molecular ffl 11000 and active oxygen 10.14
% of the following structural formula (5): % 30 parts of a polydimethylsiloxane compound having a diacyl type peroxide group in the molecule represented by formula % (5), 70 parts of vinyl acetate
and 200 parts of benzene were introduced into a flask equipped with a transcurrent condenser and a stirrer and heated at 80° C. for 20 hours in a nitrogen atmosphere.
Allowed time to react. The following procedure was carried out in the same manner as described in Example 3 to obtain 88 parts of a white polymer.

When the physical properties of the thus obtained white polymer were measured in the same manner as in Example 1, it exhibited the characteristic values shown below, and was confirmed to be a vinyl acetate-dimethylsiloxane graft polymer.

Mn'! , OIX105 M, 2.72 x 10 parts M, /M, 2.69 Nuclear magnetic resonance spectrum: 0, O8ppm (Si-CI(+)2, llppm
(VAc-CH3) Comparative Example 1 Average molecule 17400 and active oxygen 1 used in Example 1
The method described in Example 1, except that instead of the 0.79% polydimethylsiloxane compound, 28 parts of a polydimethylsiloxane compound whose only average molecular weight differs from 6900 and 3 parts of tertiary-butyl peroxyvalate (purity 99%) are used. White polymer 2 was prepared in the same manner as
I got 6 copies.

When the nuclear magnetic resonance absorption spectrum of the thus obtained white polymer was measured, absorption of the methyl group of dimethylsiloxane (0.08 ppm) was confirmed, but absorption of the benzene ring of styrene (6.56 ppm and 7.0 ppm) was confirmed.
3 ppm) was not confirmed, and no styrene-dimethylsiloxane graft polymer was obtained.

Comparative Example 2 In place of the polydimethylsiloxane compound used in Example 2 with an average molecular weight of 17,400 and an active oxygen ff of 10.79%, 28 parts of a polydimethylsiloxane compound whose average molecular weight only differs from 6,900 and tert-butyl peroxyvalate (purity 99) were used. %) was used in the same manner as described in Example 2 to obtain 26 parts of a white polymer.

When the nuclear n-gas resonance absorption spectrum of the white polymer thus obtained was measured, absorption of the methyl group of dimethylsiloxane (0.08 ppm) was confirmed, but absorption of the methyl ester group of methyl methacrylate (3.6 ppm) was confirmed.
7 ppm) was not confirmed, and no methyl methacrylate-dimethylsilokinane graft polymer was obtained.

Comparative Example 3 In place of the polydimethylsiloxane compound used in Example 3 with an average molecular weight of 74oo and an active oxygen amount of 79%, 28 parts of a polydimethylsiloxane compound whose only average molecular weight differs from 6900 and tertiary butyl peroxane parate ( Example 3 except that 3 parts (purity 99%) were used.
White polymer 26 was prepared using a method similar to that described in
I got the department.

When the nuclear magnetic resonance absorption spectrum of the white polymer 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 confirmed. was not confirmed, and no vinyl acetate-dimethylsiloxane graph 1 polymer was obtained.

Comparative Example 4 57 parts of a polydimethylsiloxane compound having a diacyl type peroxide group in the molecule with an average molecular weight FF of 13,700 and an active oxygen content of 0.41% used in Example 6 was used, in which only the average molecular weight differed from 3,500. and valeroyl peroxide (99% purity)
) 54 parts of a white polymer were obtained by operating in the same manner as described in Example 6, except that 3 parts were used.

When the nuclear magnetic co-intestinal absorption spectrum of the thus obtained white polymer was measured, absorption of the methyl group of dimethylsiloxane (0.08 ppm) was confirmed, but absorption of the benzene ring of styrene (6.56 ppm and 7.0 ppm) was confirmed.
3 ppm) was not confirmed, and no styrene-dimethylsiloxane graft polymer was obtained.

Claims (2)

[Claims] (1) When polymerizing a vinyl monomer, the following structural formula (A): ▲ There are mathematical formulas, chemical formulas, tables, etc. represents an alkyl group. Also, m is 10 to 200, n is 3 to 10, and l is 1 to 15.) Radical polymerization of a polydimethylsiloxane compound having a peroxyester group in the side chain of the molecule A method for producing a dimethylsiloxane-based graft polymer, which is characterized in that it is used as an initiator. (2) When polymerizing a vinyl monomer, the following structural formula (B): ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ...... (B) (In the formula, m is 10 to 200 and n is 3 ~10)
A method for producing a dimethylsiloxane-based graft polymer, characterized in that a polydimethylsiloxane compound having a diacyl-type peroxy group in the molecule represented by the formula is used as a radical polymerization initiator.