JPH02265912A - Production of maleimide graft copolymer - Google Patents

Abstract

PURPOSE:To obtain the title copolymer of excellent balance among properties in high yields and high grafting efficiency by an easy operation by copolymerizing a specified random vinyl copolymer with a mixture of a specified maleimide compound with a vinyl monomer. CONSTITUTION:The title copolymer is produced by polymerizing 10-500 pts. wt. mixture of 5-95wt.% maleimide compound of the formula [wherein R1 and R2 are each H, a halogen atom or CH3; and R3 is a 1-11 C alkyl, a cycloalkyl (halogen-substituted or alkyl-substituted) phenyl] (e.g. N-methylmaleimide or N-phenylmaleimide) with 95-5wt.% vinyl monomer copolymerizable therewith (e.g. styrene or vinyl chloride) in the presence of 100 pts.wt. random peroxy vinyl copolymer having an active oxygen content of 0.01-2.0%. According to the above, the operation is easy, the compositions of the main chain and the side chain and the molecular weight can be easily controlled, so that the title copolymer can be obtained industrially advantageously. This copolymer has high grafting efficiency and excellent balance among properties, so that it is useful as a molding material or a polymer modifier or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for producing a maleimide-based graft copolymer, and more particularly, to a method for producing a maleimide-based graft copolymer, and more specifically, a method for producing a maleimide-based graft copolymer, which has a high grafting effect.

The present invention also relates to a method for producing a maleimide-based graft copolymer that allows the graft copolymer to be obtained in high yield.

<Prior art> It is known that maleimide compounds can be copolymerized with various vinyl monomers to improve their thermal properties. Japanese Patent Publication No. 44-124.33 discloses that a copolymer of vinyl chloride and a maleimide compound both have high heat resistance.

However, this copolymer has the drawback that as the proportion of the maleimide compound increases, the flow processability and impact resistance decrease significantly, making it difficult to obtain a well-balanced copolymer.

On the other hand, as a method for producing a graft copolymer of vinyl monomers, Japanese Patent Publication No. 61-45647 discloses that in the presence of a copolymer containing a peroxy group, a vinyl monomer is polymerized by cleavage of the peroxy group, and then the graft copolymer is grafted. Methods for producing copolymers have been proposed.

However, at present, nothing is known about graft copolymers of maleimide compounds and methods for producing the same.

<Problems to be Solved by the Invention> The object of the present invention is to provide a method for producing a maleimide-based graft copolymer that is easy to operate and easy to control the composition and molecular weight of polymer chains, and which is extremely useful industrially. Our goal is to provide the following.

Another object of the present invention is to provide a method capable of producing a maleimide-based graft copolymer with excellent grafting efficiency and high yield.

Still another object of the present invention is to provide a method for producing a 71-neumide graft copolymer useful for molding materials, polymer modifiers, and the like.

Means for Solving the Problems> According to the present invention, a vinyl random copolymer 100 containing peroxy groups having an active oxygen amount of 0.01 to 2.0%
In the presence of parts by weight, the following formula (1) (wherein, R and R2 each represent a hydrogen atom, a halogen atom, or a methyl group, and R1 represents an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group, a phenyl group , representing a halogen-substituted phenyl group or an alkyl group-substituted phenyl group. A method for producing a maleimide-based graft copolymer is provided.

The present invention will be explained in more detail below.

The method for producing a maleimide-based graft copolymer of the present invention is characterized in that a specific vinyl-based random copolymer is polymerized with a mixture of a specific maleimide compound and a specific vinyl monomer.

In the present invention, the vinyl random copolymer can be prepared by, for example, the methods described in Japanese Patent Publication No. 57-42083, Japanese Patent Application Laid-open No. 61-91209, and the like. That is.

A copolymerizable peroxide and a vinyl monomer are subjected to known bulk, solution, emulsion or suspension polymerization using a radical polymerization initiator at a temperature that does not decompose the peroxy bonds in the copolymerizable peroxide. 9. The peroxide having copolymerizability can be produced by:

For example, t-butyl peroxyallyl carbonate.

t-hexyl peroxyallyl carbonate, 1°1.
3.3-Tetramethylbutylperoxyallyl carbonate, t-butylperoxymethallyl carbonate, t-hexylperoxyacryloyloxyethyl carbonate, cumylperoxyacryloyloxyethyl carbonate, t-amylberoxymethacryloyloxy Ethyl carbonate, cumyl peroxyacryloyloxyethyl carbonate, t-
Unsaturated peroxycarbonates such as butylberoxymethacryloyloxyethoxyoxyethyl carbonate;
t-Butyl peroxy methacrylate, t-hexyl peroxy methacrylate, t-butyl peroxy acrylate, cumyl peroxy acrylate, t-butyl peroxy crotonate, cumyl peroxy crotonate, di-t-butyl peroxy itaconate, di-butyl Peroxyfumarate, di-t-hexyl peroxymalate, t-butyl peroxymethyl fumarate,
t-Butylperoxy-i-propyl fumarate, t-
Unsaturated peroxy esters such as hexylperoxyethyl fumarate; unsaturated dialkyl peroxides such as 3-hydroxy-4-t-butylperoxybutene-1,3-hydroxy-4-cumylperoxybutene-1 are preferred. can be mentioned.

The vinyl monomer can be selected from a wide range of conjugated and non-conjugated types, such as styrene and its derivatives, acrylic acid and acrylic esters, methacrylic acid and methacrylic esters, vinyl Esters, nitriles such as acrylonitrile, vinyl halides, vinylidene halides and α-
Examples include olefins. Specifically, 1, for example, styrene, 0-methylstyrene, p-methylstyrene, 0-chlorostyrene, p-bromstyrene, p-
Methoxystyrene, α-methylstyrene, acrylic acid,
Ethyl acrylate, -0-butyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate.

n-butyl methacrylate, vinyl acetate, vinyl propionate, vinyl benzoate, vinyl chloride, vinylidene chloride, acrylonitrile, methacrylonitrile, ethylene,
Preferred examples include propylene and butadiene, which can be used alone or as a mixture.

The vinyl random copolymer containing peroxy groups (hereinafter abbreviated as random copolymer) has an active oxygen amount of 0.
It must contain peroxy groups in the range of 0.01 to 2.0%. If the amount of active oxygen is less than 0.01%, the concentration of peroxy groups will be too low, and the initiation ability during graft copolymerization will decrease. If it exceeds 2.0%, the polymerization reaction during graft copolymerization may run out of control, making handling difficult. The amount of active oxygen in the random copolymer is determined by the charging ratio of peroxide that is copolymerizable with the vinyl monomer and the conversion rate of the copolymerization reaction. That is, the amount of active oxygen in the vinyl monomer and the mixture of the vinyl monomer and the copolymerizable peroxide is 0.01 to
By mixing in a proportion within the range of 2.0% and completing the copolymerization reaction, a random copolymer having peroxy groups having an active oxygen amount within the above range can be obtained.

The amount of active oxygen in the random copolymer can be measured by an iodometry method, for example, according to the method shown in "Chemistry of Organic Peroxides" by Yoshibe Ogata, Nankodo.

The number average molecular weight of the vinyl random copolymer containing peroxy groups is preferably 100 to 300,000.

If the number average molecular weight is less than 1,000, the polymer obtained by graft copolymerization will have a star-shaped structure, which is undesirable, and if the number average molecular weight of the random copolymer is 300,000.
If it exceeds this range, dissolution or impregnation into the maleimide compound and vinyl monomer mixture will not be sufficient and will become non-uniform, which is not preferable.

The maleimide compound used in the present invention has the following formula (I), where R,, R, each represent a hydrogen atom, a halogen atom, or a methyl group, and R3 is an alkyl group having 1 to 18 carbon atoms or a cycloalkyl group. , represents a phenyl group, a halogen-substituted phenyl group, or an alkyl group-substituted phenyl group)
Specifically, 1, for example, N-methylmaleimide, N-ethylmaleimide, N-n-propylmaleimide, N-1-propylmaleimide, N-t-butylmaleimide, N-dodecylmaleimide, N- -octadecylmaleimide, N-phenylmaleimide, N-.

-Methylphenylmaleimide, N-p-isopropylphenylmaleimide, N-cyclohexylmaleimide, N
-benzylmaleimide, N-phenyl-α-glormaleimide, N-phenyl-α-methylmaleimide, etc., which can be used alone or as a mixture.

Furthermore, as the vinyl monomer copolymerizable with the maleimide compound in the present invention, one or more vinyl monomers used in preparing the aforementioned random copolymer can be selected and used.

The mixing ratio of the maleimide compound and the vinyl monomer is 5 to 95% by weight of the maleimide compound and 95 to 95% by weight of the vinyl monomer to be graft copolymerized in the presence of the random copolymer. It is in the range of 5% by weight. If the mixing ratio of the maleimide compound is less than 5% by weight, that is, the mixing ratio of the vinyl monomer exceeds 95% by weight, the ratio of maleimide residues in the resulting graft copolymer is too small, and the effect of improving heat resistance is expected. Moreover, if the mixing ratio of the maleimide compound exceeds 95% by weight, that is, if the mixing ratio of the vinyl monomer becomes less than 5% by weight, the flow processability and impact resistance of the resulting graft copolymer will decrease. It is necessary to have the above-mentioned mixing ratio.

In the present invention, the amount of the random copolymer and the mixture of the maleimide compound and vinyl monomer (hereinafter abbreviated as maleimide mixture) is 10% of the random copolymer.
0 parts by weight, the maleimide mixture ranges from 10 to 500 parts by weight. The amount of the maleimide mixture used is 10
If it is less than 500 parts by weight, no improvement in heat resistance is observed, and if it exceeds 500 parts by weight, the polymerization rate when graft polymerizing a maleimide mixture will be significantly slowed down by the peroxy group alone in the random copolymer. , problems such as polymerization not being completed occur.

In the production method of the present invention, the maleimide mixture may be polymerized by known bulk polymerization, suspension polymerization, solution polymerization, etc. in the presence of the random copolymer. It can be obtained by sufficiently impregnating, uniformly dispersing or dissolving a maleimide mixture in a random copolymer, and polymerizing preferably at a polymerization temperature in the range of 50 to 130°C for 2 to 20 hours. Polymerization temperature is 50℃
If it is less than 130°C, the polymerization rate will be extremely slow, and if it exceeds 130°C, the peroxy groups in the random copolymer will rapidly decompose, which is not preferable.

The chemical structure of the maleimide-based graft copolymer having a maleimide compound in the side chain obtained by the production method of the present invention has been determined by infrared absorption spectroscopy and proton nuclear magnetic resonance measurements, and by elemental analysis. The proportion of each monomer residue can be seen. Furthermore, the grafting efficiency can be determined by separating the graft polymer and copolymer using an extraction method or a fractional precipitation method. Further, the weight average molecular weight of the maleimide graft copolymer obtained by the present invention can be determined by gel permeation chromatography, limiting viscosity method, or the like.

<Effects of the Invention> The method for producing a maleimide-based graft copolymer of the present invention includes the following steps:
It is an industrially advantageous method because it is easy to operate and the composition and molecular weight of the main chain and side chains can be easily controlled. Furthermore, it has high grafting efficiency and excellent balance of physical properties, so it is useful as a molding material or a polymer modifier.

<Examples> Hereinafter, the present invention will be specifically explained using reference examples, examples, and application examples. In addition, all parts in the examples represent parts by weight.

300 parts of a 0.2% by weight aqueous polyvinyl alcohol solution was placed in a four-loaf flask equipped with a 1 random weight stirrer, a thermometer, a Dimroth condenser, a nitrogen gas inlet tube, and a dropping funnel, and the temperature was raised to 50°C. Next, 95 parts of styrene, 5 parts of t-butyl peroxyallyl carbonate, and 2 parts of isopropyl peroxydicarbonate as a polymerization initiator were mixed together.Then, the resulting mixed solution was stirred and nitrogen gas was introduced.
Dropped for 0 minutes, then continued stirring at 50°C for 10 minutes,
A white bead-like solid was obtained. The resulting bead-like solids were filtered, washed with water, and vacuum-dried, and the weight of the beads was 91 parts. The amount of active oxygen in this polymer is 0.4
1%, and when the infrared absorption spectrum was measured,
Absorption of the carbonyl group of the peroxycarbonate group was observed at 1780a++-''. Furthermore, the weight average molecular weight determined by gel permeation chromatography was 11000.
Polymers obtained from 1 or more which had an active oxygen content of 0.
It was found to be a styrene polymer containing 41% peroxy groups.

] 1 Shadow 2 A- Vinyl 7mer 1 The type and amount of copolymerizable peroxide, the type and amount of polymerization initiator, and the polymerization temperature and time were changed as shown in Table 1. A vinyl random copolymer containing a peroxy group was prepared in the same manner as in Reference Example 1, and various measurements were performed. The results are shown in Table 1.

A polyvinyl alcohol aqueous solution, t-butylperoxyallyl carbonate, and t-butylperoxyneodecanoate as a polymerization initiator were charged into a stainless steel autoclave in the amounts shown in Table 1, and then replaced with nitrogen gas. , 98 parts of vinyl chloride 7mer were added, 58
The polymerization reaction was carried out by raising the temperature to ℃. Next, each measurement was carried out in the same manner as in Reference Example 1. 0.2L was placed in a four-bottle flask equipped with a stirring vessel, a thermometer, a Zimrod condenser, and a nitrogen gas inlet tube. % by weight of polyvinyl alcohol (saponification degree 89%) aqueous solution was charged, 100 parts of the styrene copolymer produced in Reference Example 1, 50 parts of cyclohexylmaleimide, and 50 parts of methyl methacrylate were charged and heated at 25°C for 1 hour. A suspension was prepared by stirring vigorously. Then, the reaction temperature was raised to 90° C. to initiate polymerization, and stirring was continued for 16 hours to obtain bead-like solids.

The resulting bead-shaped solids were taken from house to house, washed with water, and then dried under reduced pressure, and the mass was 178 parts.

The weight average molecular weight of this polymer was measured using gel permeation chromatography (hereinafter abbreviated as GPC) and was found to be 276,000.

Also, when the infrared absorption spectrum was measured, it was found to be 1700a11.
The absorption of the carbonyl group of the maleimide group in ``1'' is 172
5C! Absorption of the carbonyl group of the methyl methacrylate residue was observed at I-'. Furthermore, the total nitrogen content by single element analysis was found to be 1.91%, and the proportion of maleimide residues in the polymer was found to be 24.4%. The reaction conditions, yield, weight average molecular weight and
Graft copolymerization was carried out in the same manner as in Example 1, except that the type of copolymer used, the type and amount of maleimide compound, the type and amount of vinyl monomer, polymerization temperature, and polymerization time were changed. A combination was prepared and each measurement was performed. The conditions and results are shown in Table 2.

30 parts of the graft copolymer prepared in Example 7 was blended with 70 parts of polyvinyl chloride with a degree of polymerization of 100 to obtain a blended resin with physical properties, followed by 1.7 parts of tribasic lead sulfate and stearin. After blending 1.8 parts of lead acid and 0.5 part of calcium stearate, a molding material was produced under roll conditions of 180°C for 5 minutes and press conditions of 200°C (5 minutes of preheating, 3 minutes of pressure). Each physical property test shown in Table 1 and 3 was conducted on the obtained molding material. The results are shown in Table 3.

As a blend resin, 10 parts of a copolymer with a weight average molecular weight of 180,000 prepared by suspension polymerization of 80% by weight of phenylmaleimide and 20% by weight of methyl methacrylate is blended with 90 parts of polyvinyl chloride having a degree of polymerization of 1000. A molding material was produced in the same manner as in Reference Example 6, except that the resin was used.
Various physical property tests were conducted. The results are shown in Table 3.

Table 3 3) JIS K-7110

Claims (1)

[Scope of Claims] In the presence of 100 parts by weight of a vinyl random copolymer containing peroxy groups with an active oxygen content of 0.01 to 2.0%, the following general formula (I) ▲ Numerical formula, chemical formula, table, etc. ▼...(I) (In the formula, R_1 and R_2 each represent a hydrogen atom, a halogen atom, or a methyl group, and R_3 is an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group, a phenyl group, or a halogen-substituted phenyl group. or an alkyl group-substituted phenyl group) and 95 to 95% by weight of a vinyl monomer copolymerizable with the maleimide compound.
A method for producing a maleimide-based graft copolymer, which comprises polymerizing 10 to 500 parts by weight of a 5% by weight mixture.