JP3469264B2 - Production method of heat-resistant copolymer - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention comprises a maleimide and / or N-substituted maleimide, a vinyl aromatic compound and a vinyl cyan compound, and has a good mechanical strength, as well as excellent heat resistance and high temperature stability. The present invention relates to a method for producing a coalescence.

[0002]

BACKGROUND OF THE INVENTION Copolymers of vinyl aromatic compounds and maleic anhydride (hereinafter referred to as S
It is known that MA resin) has good compatibility with a styrene-acrylonitrile copolymer and has a high heat distortion temperature, that is, good heat resistance. It is also known that the imidization of maleic anhydride further improves the high temperature stability and moldability.

When, for example, a suspension polymerization method or an emulsion polymerization method is adopted as a method for producing an SMA resin, maleic anhydride is hydrolyzed to be transformed into maleic acid or fumaric acid to efficiently obtain a desired product. I can't. Further, when the bulk polymerization method is adopted, thermal decomposition of the maleic anhydride residue may occur in the final devolatilization step, and it is necessary to increase the imidization step separately in order to improve the physical properties. Not.

In order to solve the above problems, a bulk-suspension polymerization method has been proposed (Japanese Patent Publication No. 3-33722). In the method described in this publication, maleic anhydride and a vinyl aromatic compound monomer are polymerized in a bulk form, and a copolymer and an unreacted monomer (mainly a vinyl aromatic compound monomer) are obtained. In the first step of obtaining a mixed syrup, a vinyl cyanide compound monomer is added to and mixed with the syrup obtained here, the mixture is suspended in water, and the monomer contained in the syrup is suspended in a suspended state. The second step comprises polymerizing and imidizing a maleic anhydride residue contained in the copolymer chain produced in the first step with an aromatic amine.

However, it is desirable that the syrup obtained in the first step in this conventional method has good fluidity in order to facilitate the subsequent operation. For that purpose, the unreacted monomer () which constitutes the syrup ( It is preferable to increase the mixing ratio of mainly vinyl aromatic compound monomer). When the proportion of the unreacted monomer is increased, the amount of the vinyl cyan compound monomer added in the second step also increases correspondingly, and as a result, the N-aromatic maleimide-vinyl is added in the final product composition. The ratio of the vinyl aromatic compound-vinyl cyan compound copolymer to the aromatic compound copolymer becomes large.

However, the vinyl aromatic compound-vinyl cyan compound copolymer does not help to improve the heat resistance and the high temperature stability, and therefore the proportion of this copolymer becomes large, and the N-aromatic maleimide-vinyl copolymer is used. Reducing the proportion of the aromatic compound copolymer is not preferable from the viewpoint of improving heat resistance and high temperature stability. The present invention, in the bulk-suspension polymerization method as described above, a resin having an increased composition ratio of a copolymer having a maleimide residue or an N-substituted maleimide residue and further improved heat resistance and high temperature stability. It is intended to provide a method of making a composition.

[0007]

Means for Solving the Problems The present invention achieves the above objects, and the gist thereof is to provide a maleimide and / or N-substituted maleimide, a vinyl aromatic compound and a vinyl aromatic compound by a bulk-suspension polymerization method. A method for producing a copolymer comprising a vinyl cyan compound, comprising: (1) allowing a vinyl aromatic compound-maleic anhydride monomer mixture containing 1 to 6% by weight of maleic anhydride to be present in a polymerization system. Polymerization proceeds while continuously adding maleic anhydride alone or a mixture of maleic anhydride and a vinyl aromatic compound monomer to the polymerization system, and at that time, the maleic anhydride residue amount in the produced copolymer is adjusted to 20%. The mass polymerization is carried out until the conversion of the above-mentioned monomers into the produced copolymer reaches 30 to 70% by weight of all the charged monomers in the first step polymerization system. One step, 2) Next, a maleimide monomer and / or an N-substituted maleimide monomer and a vinyl cyanide compound monomer are added to this polymerization system, the mixture is suspended in water, and the monomer is suspended. The second step of copolymerization,
(3) A heat-resistant copolymer which further comprises a third step of imidizing a maleic anhydride residue contained in the copolymer chain produced in the first step with a primary amine and / or ammonia. It exists in a method for producing a polymer.

The first step in the method of the present invention is a step of bulk-polymerizing maleic anhydride and a vinyl aromatic compound monomer to produce a syrup in which the resulting copolymer and unreacted monomer are mixed. is there. A copolymer of maleic anhydride and a vinyl aromatic compound monomer contained in this syrup (hereinafter, abbreviated as SMA copolymer) is imidized in a later step to improve heat resistance and high temperature stability. It is a precursor for making excellent copolymers. The syrup is composed of a mixture of an SMA copolymer and an unreacted monomer, and the unreacted monomer is mainly composed of a vinyl aromatic compound monomer.

Styrene is generally used as the vinyl aromatic compound monomer used in the first step, but α-methylstyrene, p-methylstyrene, o-methylstyrene, t-butylstyrene or o-chlorostyrene is used. Styrene, p-
Examples thereof include halogenated styrenes such as chlorostyrene, and these may be one kind or a mixture of two or more kinds.

In the first step of the method of the present invention,
First, a vinyl aromatic compound-maleic anhydride monomer mixture containing 1 to 6% by weight of maleic anhydride is present in the polymerization system. Then, the maleic anhydride alone or the mixture of maleic anhydride and a vinyl aromatic compound monomer is continuously added to the polymerization system to proceed with the polymerization.
20-40% by weight of maleic anhydride residue in the copolymer
Control to the range of. In this polymerization, in order to make the content of the maleic anhydride residue in the SMA copolymer finally obtained in the first step 20% by weight, the mixed monomer to be present before the initiation of the polymerization in the first step is used. Content of maleic anhydride in 1
In order to make the content of the maleic anhydride residue in the finally obtained SMA copolymer 40% by weight,
The content of maleic anhydride in the mixed monomer that is present before the start of polymerization in the first step is 6% by weight, and the content may be selected within this range.

This selection was made by comparing the vinyl aromatic compound monomer-maleic anhydride copolymerization curve (concentration of maleic anhydride residue concentration in the SMA copolymer with that of maleic anhydride in the monomer mixture). Can be easily performed. In the first step of the present invention, bulk polymerization is continued while continuously adding maleic anhydride alone in a molten state or maleic anhydride in a vinyl aromatic compound monomer.

In the first step of the process of the present invention, a monomer mixture containing a small amount of maleic anhydride is added at a polymerization temperature of 10
At around 0 ° C., the polymerization proceeds at a considerable rate even if almost no polymerization initiator is used. The vinyl aromatic compound-maleic anhydride monomer mixture has a polymerization rate in the first step, and a SMA copolymer produced in this step, depending on the amount of maleic anhydride present in the polymerization system in a normally employed polymerization temperature range. The content of maleic anhydride in the product is regulated. For this reason,
In the method of the present invention, a small amount of maleic anhydride within a predetermined range is mixed with the monomer mixture existing in the polymerization system before the initiation of polymerization in the first step to initiate the polymerization, and then the maleic anhydride is continuously added. A method is employed in which the acid alone is continuously added in a molten state or maleic anhydride is dissolved in a vinyl aromatic compound monomer.

The rate of continuously adding the above-mentioned mixture of monomers and the concentration of the added monomer mixture are such that the maleic anhydride in the vinyl aromatic compound-maleic anhydride monomer mixture present in the bulk polymerization system. It is preferred that the weight percent of acid be substantially constant. By adopting the above addition method, the content of maleic anhydride in the SMA copolymer produced from the initial stage of the first step by the bulk polymerization method can be constantly made almost constant.

In the method of the present invention, the content of maleic anhydride is 20 to 40% by weight in the first step of the bulk polymerization method.
Within the range, SMA copolymer having a substantially constant composition is produced. When the content of maleic anhydride in the SMA copolymer produced in this step is less than 20% by weight, the contribution to the improvement of heat resistance of the finally obtained polymer is small, which is not preferable. On the other hand, the content rate of maleic anhydride is 40% by weight.
If it exceeds, the compatibility with the polymer formed in the second step by the subsequent suspension polymerization method becomes poor, and the mechanical strength of the polymer finally obtained becomes poor, which is not preferable.

In the bulk polymerization in the first step, the conversion of the monomer mixture to the SMA copolymer in the first step is set to 30 to 70% by weight based on the total amount of the monomers charged in the first step polymerization system. Good. When the conversion rate of the above monomer is less than 30% by weight, the amount of the SMA copolymer produced in the first step does not become sufficiently high,
Improvement in heat resistance of the finally obtained copolymer is not achieved. On the other hand, when the monomer conversion exceeds 70% by weight, the viscosity of the syrup produced becomes too large, which makes it difficult to shift to the suspension polymerization in the second step, which is not preferable. In the first step of the method of the present invention, a small amount of an organic solvent such as methyl ethyl ketone, acetone, ethylbenzene is added to the polymerization system in order to prevent the SMA copolymer formed during bulk polymerization from becoming too viscous or precipitating. Can be added.

In the method of the present invention, water containing a suspending agent is added to a mixture obtained by newly adding a monomer to the syrup of the SMA copolymer obtained in the first step and the unreacted monomer. The second step of substantially completing the polymerization by the suspension polymerization method is performed. In this second step, the vinyl aromatic compound monomer remaining as the unreacted monomer in the first step and the maleimide and / or N-substituted maleimide monomer newly added and vinyl cyan compound unit amount are added. A copolymer consisting of the polymer and the SMA copolymer produced in the first step is polyblended in this polymerization system in a compatible state.

A maleimide and / or N-substituted maleimide monomer (that is, a maleimide compound monomer) and a vinyl cyan compound monomer in the initial stage of the second step of the present invention,
Further, the monomer composition ratio of the three components of the vinyl aromatic compound monomer which has not been consumed in the first step is the range surrounded by the line connecting the four points A, B, C and D in the triangular coordinate of FIG. Preferably within. When the polymerization is carried out at a charging ratio outside this range, a copolymer having an incompatible composition is formed, and the mechanical strength and heat resistance of the heat-resistant copolymer finally obtained tend to be lowered, which is preferable. Absent.

The composition of the copolymer finally obtained in the second step of the method of the present invention is such that the vinyl aromatic compound is 35 to 70% by weight, maleic anhydride is 5 to 20% by weight, maleimide and / or N-substituted. Maleimide (maleimide compound) 5
The composition is preferably in the range of 35% by weight and 10 to 30% by weight of the vinyl cyan compound. In order to adjust the composition of the polymer to be within the above range, it is preferable to adjust the addition amount ratio of the monomer to the polymerization system in the first step and the second step as described above. In the present invention, the polymerization is substantially completed by the suspension polymerization in the second step, but in this case, the amount of water used is 8 per 100 parts by weight of the mixture used in the second step.
A range of 0 to 300 parts by weight is industrially advantageous.

Suspension stabilizers that can be used in the second step of the present invention include polyvinyl alcohol (PVA), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), methyl hydroxypropyl cellulose (metrose), polyoxyethylene, Examples thereof include polyoxypropylene, polyoxyethylene block copolymer (Bluronic), polyacrylate, gelatin, alkylbenzene sulfonate, fatty acid salt, alkylbenzene polyethylene oxide adduct, and inorganic colloid. The amount of the suspension stabilizer used is 10
It is 0.001 to 1.0 part by weight, preferably 0.01 to 0.8 part by weight, relative to 0 part by weight.

A polymerization initiator can be used in the first step and the second step. As the polymerization initiator that can be used in this case, azo compounds such as azobisisobutyronitrile and azobisdimethylvaleronitrile, organic peroxides,
Examples thereof include redox catalysts. In the method of the present invention, after the completion of the second step, the unreacted monomer existing in the polymerization system, and when the organic solvent is allowed to exist in the polymerization system in the first step, the organic solvent is recovered by steam distillation.

In the present invention, in order to improve the high temperature stability and molding processability of the resulting copolymer, the SMA copolymer obtained in the first step is further treated with a primary amine and / or ammonia. A third step of imidizing the maleic anhydride residue is carried out. As the primary amine, aniline is industrially easily available and most suitable, but halogenated aniline, nitroaniline, toluidine, α-naphthylamine, phenylenediamine, or a mixture thereof is also used. The addition amount of the primary amine and / or ammonia is
The molar ratio of the maleic anhydride residue of the SMA copolymer obtained in the first step is preferably 0.8 to 1.5 times.

With the addition of primary amines, especially aniline,
It reacts with maleic anhydride residues contained in the SMA copolymer to form a monoamide. The addition of the primary amine may be performed after the completion of the first step, or the maleimide and / or N-substituted maleimide monomer in the second step,
It does not matter at the same time as the addition of the vinyl cyan compound monomer, during the second step, or after the end of the second step. However, as the imidization reaction is performed at a higher temperature, the imidization ratio becomes higher, so that the temperature is finally raised to 120 to 190 ° C. At this time, the ratio of imidization in the maleic anhydride residue is 70% by weight or more, preferably 75 to 99.
% By weight.

The composition of the copolymer finally obtained through all the steps of the method of the present invention has a vinyl aromatic compound content of 20 to 70.
% By weight, maleimide and / or N-substituted maleimide is 1
Copolymerizable with 0 to 60% by weight, 10 to 40% by weight of vinyl cyanide compound, maleic anhydride, and the above components which may be added to the above first to third steps within a range not impairing the object of the present invention. Compound (for example, acrylic acid ester, methacrylic acid ester, maleic acid ester, etc.) 0 to 10
It is preferably in the range of% by weight.

The heat-resistant copolymer obtained by the method of the present invention may be used alone, but may also be used as ABS resin, AES resin,
You may blend with AAS resin etc. and may be used as a heat resistant resin which gave the impact resistance. Further, the heat-resistant copolymer obtained by the method of the present invention may contain a small amount of a primary amine and a maleic anhydride residue which is not imidized with ammonia, whereby an engineering plastic such as nylon or polycarbonate can be obtained. It has good compatibility even when blended with, and can impart various properties in addition to heat resistance.

[0025]

EXAMPLES Examples will be described below, but the present invention is not limited to these examples without departing from the gist thereof. Example 1 Styrene 4709 in a 20 liter autoclave
g and 156 g of maleic anhydride were added, and the temperature was raised to 110 ° C. with stirring while substituting with nitrogen. Bulk polymerization was carried out at 110 ° C. for 220 minutes while continuously adding 943 g of maleic anhydride melted at 70 ° C. to this system at the addition rate shown in Table 1 below.

[0026]

[Table 1]

Upon completion of continuous addition, the polymerization rate was 55% by weight, and the content of maleic anhydride residue in the SMA copolymer produced was 33% by weight. To this system, 1742 g of N-phenylmaleimide, 1451 g of acrylonitrile and 14.5 g of terpinolene were added, and the temperature inside the system was lowered to 70 ° C.
Stirring was continued for hours. At this time, the ratio of monomers present in the system is styrene / N-phenylmaleimide / acrylonitrile = 45/30/25% by weight. Then, deionized water 9000g, polyvinyl alcohol suspension 4.0
When 6 g, polyacrylic acid ester suspension agent 3.38 g, and sodium sulfate 54.0 g were added, and when the temperature reached 90 ° C.
-5.81 g of tert-butyl azo-1-cyanocyclohexane was added, and the temperature was raised to 110 ° C over 4 hours.

Thereafter, the temperature was raised to 150 ° C. over 2 hours, and unreacted monomers were removed by steam distillation for 1 hour. The amount of the removed monomer was 240 g, and the total amount was styrene or acrylonitrile. After that, aniline 1
After adding 048 g and carrying out an imidization reaction at 155 ° C. for 1 hour, the temperature of the polymerization system was immediately cooled to room temperature. The bead-like copolymer obtained was separated from water with a filter cloth, washed with water and dried. The yield of the beaded copolymer was 9300 g.
The beaded copolymer was kneaded and pelletized while being devolatilized by an extruder with a vent. The composition of the pellet is styrene 4
9.2% by weight, maleic anhydride 1.7% by weight, N-phenylmaleimide 35.8% by weight, acrylonitrile 1
It was 3.3% by weight.

Example 2 5063 g of styrene and 168 g of maleic anhydride were placed in a 20-liter autoclave, and the temperature was raised to 110 ° C. while substituting nitrogen with stirring. 1014 g of maleic anhydride melted at 70 ° C. was continuously added to this system at an addition rate shown in Table 2 below, and bulk polymerization was performed at 110 ° C. for 220 minutes.
When the continuous addition was completed, the polymerization rate was 55% by weight, and the SMA formed
The content of maleic anhydride residue in the copolymer is 33% by weight.
Met.

[0030]

[Table 2]

N-phenylmaleimide 1104 was added to this system.
g, acrylonitrile 1656g, terpinolene 1
3.8 g was added, the system temperature was lowered to 70 ° C., and stirring was continued for 1 hour. At this time, the ratio of monomers present in the system was styrene / N-phenylmaleimide / acrylonitrile = 5.
It is 0/20/30% by weight. Then deionized water 90
00 g, polyvinyl alcohol-based suspension agent 4.06 g, polyacrylic acid ester-based suspension agent 4.06 g, and sodium sulfate 54.0 g were added, and when the temperature reached 90 ° C. 1-tert-butyl azo-1-cyanocyclohexane 5 .52
g was added and the temperature was raised to 110 ° C. over 4 hours.

Thereafter, the temperature was raised to 150 ° C. over 2 hours, and unreacted monomers were removed by steam distillation for 1 hour. The amount of the removed monomer was 200 g, and all of them were styrene or acrylonitrile. After that, aniline 1
After adding 122 g and carrying out an imidization reaction at 155 ° C. for 1 hour, the temperature of the polymerization system was immediately cooled to room temperature. The bead-shaped copolymer obtained was separated from water with a filter cloth, washed with water, and dried. The yield of the beaded copolymer was 9400 g.
The beaded copolymer was kneaded and pelletized while being devolatilized by an extruder with a vent. The composition of the pellet is styrene 5
2.5% by weight, maleic anhydride 1.8% by weight, N-phenylmaleimide 30.1% by weight, acrylonitrile 1
It was 5.6% by weight.

Example 3 5063 g of styrene and 168 g of maleic anhydride were placed in a 20-liter autoclave, and the temperature was raised to 110 ° C. while substituting with nitrogen while stirring. 1104 g of maleic anhydride melted at 70 ° C. was continuously added to this system at the same addition rate as described in Table 2 in Example 2 above while continuously adding 110
Bulk polymerization was carried out at 220C for 220 minutes. The polymerization rate at the time of continuous addition completion was 55% by weight, and the content rate of the maleic anhydride residue in the SMA copolymer produced was 33% by weight. N in this system
-Phenylmaleimide 1656 g, acrylonitrile 1
104 g and terpinolene 13.8 g were added, the system temperature was lowered to 70 ° C., and stirring was continued for 1 hour.

At this time, the ratio of monomers present in the system was styrene / N-phenylmaleimide / acrylonitrile =
It is 50/30/20% by weight. Then deionized water 9
000 g, polyvinyl alcohol suspension 4.06 g,
When a polyacrylic acid ester suspension agent 4.06 g and sodium sulfate 54.0 g were added, and when the temperature reached 90 ° C., 1-tert-butyl azo-1-cyanocyclohexane 5.5.
2 g was added and the temperature was raised to 110 ° C. over 4 hours. Then, the temperature was raised to 150 ° C. over 2 hours, and unreacted monomer was removed by steam distillation for 1 hour.

The amount of the removed monomer was 180 g, and the total amount was styrene or acrylonitrile. afterwards,
Further, 1122 g of aniline was added, the imidization reaction was carried out at 155 ° C. for 1 hour, and then the temperature of the polymerization system was immediately cooled to room temperature. The bead copolymer obtained is separated from water with a filter cloth,
It was washed with water and dried. The yield of beaded copolymer is 9300
It was g. The beaded copolymer was kneaded and pelletized while being devolatilized by an extruder with a vent. The composition of the pellet was 52.4% by weight of styrene, 1.8% by weight of maleic anhydride, 35.8% by weight of N-phenylmaleimide and 10.0% by weight of acrylonitrile.

Example 4 5063 g of styrene and 168 g of maleic anhydride were placed in a 20-liter autoclave, and the temperature was raised to 110 ° C. while substituting with nitrogen while stirring. 1104 g of maleic anhydride melted at 70 ° C. was continuously added to this system at the same addition rate as described in Table 2 in Example 2 above while continuously adding 110
Bulk polymerization was carried out at 220C for 220 minutes. The polymerization rate at the time of continuous addition completion was 55% by weight, and the content rate of the maleic anhydride residue in the SMA copolymer produced was 33% by weight. N-in this system
Phenylmaleimide 552g, acrylonitrile 220
8 g and terpinolene 13.8 g were added, and the system temperature was adjusted to 7
The temperature was lowered to 0 ° C. and stirring was continued for 1 hour.

At this time, the ratio of monomers present in the system was styrene / N-phenylmaleimide / acrylonitrile =
It is 50/10/40% by weight. Then deionized water 9
000 g, polyvinyl alcohol suspension 4.06 g,
When a polyacrylic acid ester suspension agent 4.06 g and sodium sulfate 54.0 g were added, and when the temperature reached 90 ° C., 1-tert-butyl azo-1-cyanocyclohexane 5.5.
7g was added and it heated up to 110 degreeC over 4 hours. Then, the temperature was raised to 150 ° C. over 2 hours, and unreacted monomer was removed by steam distillation for 1 hour.

The amount of the removed monomer was 280 g, and the total amount was styrene or acrylonitrile. afterwards,
Further, 1122 g of aniline was added, the imidization reaction was carried out at 155 ° C. for 1 hour, and then the temperature of the polymerization system was immediately cooled to room temperature. The bead-shaped copolymer obtained was separated from water with a filter cloth, washed with water, and dried. The yield of beaded copolymer was 93.
It was 00 g. The beaded copolymer was kneaded and pelletized while being devolatilized by an extruder with a vent. The composition of the pellets was 52.7% by weight of styrene, 1.9% by weight of maleic anhydride, 24.5% by weight of N-phenylmaleimide and 20.9% by weight of acrylonitrile.

Example 5 3592 g of styrene and 119 g of maleic anhydride were placed in a 20-liter autoclave and the temperature was raised to 110 ° C. while substituting with nitrogen while stirring. 720 g of maleic anhydride melted at 70 ° C. was continuously added to this system at the addition rate shown in Table 3 below, and bulk polymerization was performed at 110 ° C. for 220 minutes. The polymerization rate at the time of continuous addition completion was 55% by weight, and the content rate of the maleic anhydride residue in the SMA copolymer produced was 33% by weight.

[0040]

[Table 3]

N-phenylmaleimide 2611 was added to this system.
g, acrylonitrile 1958g, terpinolene 1
6.3 g was added, the system temperature was lowered to 70 ° C., and stirring was continued for 1 hour. At this time, the ratio of monomers present in the system was styrene / N-phenylmaleimide / acrylonitrile = 3.
It is 0/40/30% by weight. Then deionized water 90
00 g, polyvinyl alcohol-based suspension agent 4.06 g, polyacrylic acid ester-based suspension agent 4.06 g, and sodium sulfate 54.0 g were added, and when the temperature reached 90 ° C, 1-tert-butyl azo-1-cyanocyclohexane 6 .53
g was added and the temperature was raised to 110 ° C. over 4 hours. Then, the temperature was raised to 150 ° C. over 2 hours, and the unreacted monomer was removed by steam distillation for 1 hour.

The amount of the removed monomer was 300 g, and the total amount was styrene or acrylonitrile. Thereafter, 796 g of aniline was further added, and an imidization reaction was carried out at 155 ° C. for 1 hour, and then the temperature of the polymerization system was immediately cooled to room temperature. The bead-shaped copolymer obtained was separated from water with a filter cloth, washed with water, and dried. The yield of beaded copolymer is 90.
It was 00 g. The beaded copolymer was kneaded and pelletized while being devolatilized by an extruder with a vent. The composition of the pellets was 38.2% by weight of styrene, 1.4% by weight of maleic anhydride, 41.9% by weight of N-phenylmaleimide and 18.6% by weight of acrylonitrile.

Example 6 5894 g of styrene and 196 g of maleic anhydride were placed in a 20-liter autoclave, and the temperature was raised to 110 ° C. while substituting nitrogen with stirring. 1180 g of maleic anhydride melted at 70 ° C. was continuously added to this system at an addition rate shown in Table 4 below, and bulk polymerization was performed at 110 ° C. for 220 minutes.
When the continuous addition was completed, the polymerization rate was 55% by weight, and the SMA formed
The content of maleic anhydride residue in the copolymer is 33% by weight.
Met.

[0044]

[Table 4]

N-phenylmaleimide 494 was added to this system.
g, acrylonitrile 1236g, terpinolene 1
2.4 g was added, the system temperature was lowered to 70 ° C., and stirring was continued for 1 hour. At this time, the ratio of monomers present in the system was styrene / N-phenylmaleimide / acrylonitrile = 6.
It is 5/10/25% by weight. Then deionized water 90
00 g, polyvinyl alcohol-based suspension agent 4.06 g, polyacrylic acid ester-based suspension agent 4.06 g, and sodium sulfate 54.0 g were added, and when 90 ° C. was reached, 1-tert-butyl azo-1-cyanocyclohexane 4 .9 g
Was added and the temperature was raised to 110 ° C. over 4 hours. afterwards,
The temperature was raised to 150 ° C. over 2 hours, and unreacted monomers were removed by steam distillation for 1 hour.

The amount of the removed monomer was 250 g, and the total amount was styrene or acrylonitrile. afterwards,
Further, 1306 g of aniline was added, and the imidization reaction was carried out at 155 ° C. for 1 hour, and then the temperature of the polymerization system was immediately cooled to room temperature. The bead-shaped copolymer obtained was separated from water with a filter cloth, washed with water, and dried. The yield of beaded copolymer is 90.
It was 00 g. The beaded copolymer was kneaded and pelletized while being devolatilized by an extruder with a vent. The composition of the pellet was 60.6% by weight of styrene, 2.1% by weight of maleic anhydride, 26.5% by weight of N-phenylmaleimide and 10.7% by weight of acrylonitrile.

Comparative Example 1-1 5720 g of styrene and 189 g of maleic anhydride were placed in a 20-liter autoclave, and the temperature was raised to 110 ° C. while substituting with nitrogen while stirring. 1143 g of maleic anhydride melted at 70 ° C. was continuously added to this system at an addition rate shown in Table 5 below, and bulk polymerization was performed at 110 ° C. for 220 minutes.
When the continuous addition was completed, the polymerization rate was 55% by weight,
The content of maleic anhydride residue in the copolymer is 33% by weight.
Met.

[0048]

[Table 5]

While adding 1038 g of acrylonitrile to this system, the temperature of the system was lowered to 95 ° C., and at this temperature, another 1
Stirring was continued for hours. At that time, the monomer ratio present in the system is styrene / acrylonitrile = 75/25 wt%. Thereafter, 9000 g of deionized water, 3.0 g of a polyvinyl alcohol-based suspension agent, 3.0 g of a polyacrylic acid ester-based suspension agent, and 30.0 g of sodium sulfate were added to bring the system into a suspended state. Azobisisobutyl nitrile 4
g was added and polymerization was carried out at 80 ° C. for 90 minutes. 1 over 60 minutes
The temperature was raised to 50 ° C., and unreacted monomers were removed by steam distillation at this temperature for 1 hour. The amount of the removed monomer was 300 g.

Thereafter, 1264 g of aniline was added, and
After carrying out the imidization reaction at 5 ° C. for 1 hour, the temperature of the polymerization system was immediately cooled to room temperature. The beaded copolymer obtained,
It was separated from water with a filter cloth, washed with water, and dried. The yield of the beaded copolymer was 8300 g. The beaded copolymer was kneaded and pelletized while being devolatilized by an extruder with a vent. The composition of the pellets was 64.6% by weight of styrene, 1.4% by weight of maleic anhydride, and 23.N-phenylmaleimide.
It was 3% by weight and 10.7% by weight of acrylonitrile.

Comparative Example 1-2 5720 g of styrene and 189 g of maleic anhydride were placed in a 20-liter autoclave, and the temperature was raised to 110 ° C. while substituting nitrogen with stirring. 1143 g of maleic anhydride melted at 70 ° C. was continuously added to this system at the same addition rate as described in Table 5 in Comparative Example 1-1 above while continuously adding 1
Bulk polymerization was carried out at 10 ° C. for 220 minutes. The polymerization rate at the time of continuous addition completion was 55% by weight, and the content rate of the maleic anhydride residue in the SMA copolymer produced was 33% by weight. While adding 1000 g of acrylonitrile to the system, the temperature of the system was lowered to 95 ° C., and stirring was continued for another hour at this temperature.

Then, 9000 g of deionized water, 3.0 g of polyvinyl alcohol type suspension agent, 3.0 g of polyacrylic acid ester type suspension agent and 30.0 g of sodium sulfate were added to bring the system into a suspended state. The temperature of the system was raised to 105 ° C., and unreacted monomers were recovered by steam distillation for 1.5 hours. Then, 300 g of acrylonitrile was further added, the temperature was raised to 150 ° C. over 1 hour, and steam distillation was performed again. The total amount of monomers removed was 2200 g. At that temperature, 1264 g of aniline was added, an imidization reaction was carried out at 155 ° C. for 1 hour, and then the temperature of the polymerization system was immediately cooled to room temperature.

The beaded copolymer obtained was separated from water by a filter cloth, washed with water, and dried. The yield of the beaded copolymer was 6500 g. The beaded copolymer was kneaded and pelletized while being devolatilized by an extruder with a vent. The composition of the pellets was styrene 61.8% by weight, maleic anhydride 1.
The content was 7% by weight, N-phenylmaleimide 28.8% by weight, and acrylonitrile 7.6% by weight.

Comparative Example 2-1 A 20-liter autoclave was charged with 5894 g of styrene and 196 g of maleic anhydride, and the temperature was raised to 110 ° C. while substituting with nitrogen while stirring. 110 g of maleic anhydride melted at 70 ° C. was continuously added to this system at the same addition rate as described in Table 4 in Example 6 above.
Bulk polymerization was carried out at 220C for 220 minutes. The polymerization rate at the time of continuous addition completion was 55% by weight, and the content rate of the maleic anhydride residue in the SMA copolymer produced was 33% by weight. N-in this system
Phenylmaleimide 1236g, acrylonitrile 49
4 g and 12.4 g of terpinolene were added, and the temperature inside the system was adjusted to 7
The temperature was lowered to 0 ° C. and stirring was continued for 1 hour.

At this time, the ratio of monomers present in the system was styrene / N-phenylmaleimide / acrylonitrile =
It is 65/25/10% by weight. Then deionized water 9
000 g, polyvinyl alcohol suspension 4.06 g,
A polyacrylic ester type suspension agent (4.06 g) and sodium sulfate (54.0 g) were added, and when the temperature reached 90 ° C, 1-tert-butyl azo-1-cyanocyclohexane 4.9.
4g was added and it heated up to 110 degreeC over 4 hours. Then, the temperature was raised to 150 ° C. over 2 hours, and the unreacted monomer was removed by steam distillation for 1 hour.

The amount of the removed monomer was 150 g, and the total amount was styrene or acrylonitrile. afterwards,
Further, 1305 g of aniline was added, an imidization reaction was carried out at 155 ° C. for 1 hour, and then the temperature of the polymerization system was immediately cooled to room temperature. The bead-shaped copolymer obtained was separated from water with a filter cloth, washed with water, and dried. The yield of beaded copolymer was 93.
It was 00 g. The beaded copolymer was kneaded and pelletized while being devolatilized by an extruder with a vent. The composition of the pellets was 59.9% by weight of styrene, 2.1% by weight of maleic anhydride, 33.9% by weight of N-phenylmaleimide and 4.1% by weight of acrylonitrile.

Comparative Example 2-2 5432 g of styrene and 185 g of maleic anhydride were placed in a 20-liter autoclave and the temperature was raised to 110 ° C. while substituting with nitrogen while stirring. 1099 g of maleic anhydride melted at 70 ° C. was continuously added to this system at an addition rate shown in Table 6 below, and bulk polymerization was performed at 110 ° C. for 220 minutes.
When the continuous addition was completed, the polymerization rate was 55% by weight, and the SMA formed
The content of maleic anhydride residue in the copolymer is 33% by weight.
Met.

[0058]

[Table 6]

N-phenylmaleimide 1565 was added to this system.
g, acrylonitrile 652 g, terpinolene 13.
0 g was added, the system temperature was lowered to 70 ° C., and stirring was continued for 1 hour. At this time, the ratio of monomers present in the system was styrene / N-phenylmaleimide / acrylonitrile = 57.
It is 5/30 / 12.5% by weight. Then, deionized water 9000g, polyvinyl alcohol suspension 4.06
g, polyacrylic acid ester suspension agent 4.06 g, and sodium sulfate 54.0 g were added, and when the temperature reached 90 ° C. 1-
5.22 g of tert-butyl azo-1-cyanocyclohexane was added, and the temperature was raised to 110 ° C. over 4 hours. Then, the temperature was raised to 150 ° C. over 2 hours, and unreacted monomer was removed by steam distillation for 1 hour.

The amount of monomer removed was 150 g, and the total amount was styrene or acrylonitrile. afterwards,
Further, 1218 g of aniline was added, an imidization reaction was carried out at 155 ° C. for 1 hour, and then the temperature of the polymerization system was immediately cooled to room temperature. The bead-shaped copolymer obtained was separated from water with a filter cloth, washed with water, and dried. The yield of beaded copolymer is 92.
It was 00 g. The beaded copolymer was kneaded and pelletized while being devolatilized by an extruder with a vent. The composition of the pellets was 56.2% by weight of styrene, 2.0% by weight of maleic anhydride, 36.1% by weight of N-phenylmaleimide and 5.7% by weight of acrylonitrile.

Comparative Example 2-3 6570 g of styrene and 219 g of maleic anhydride were placed in a 20 liter autoclave, and the temperature was raised to 110 ° C. while substituting with nitrogen while stirring. 1315 g of maleic anhydride melted at 70 ° C. was continuously added to this system at an addition rate shown in Table 7 below, and bulk polymerization was performed at 110 ° C. for 220 minutes. When the continuous addition was completed, the polymerization rate was 55% by weight, and the generated S
The content of maleic anhydride residue in the MA copolymer was 33% by weight.

[0062]

[Table 7]

N-phenylmaleimide 448 was added to this system.
g, acrylonitrile 448 g, terpinolene 11.
2 g was added, the system temperature was lowered to 70 ° C., and stirring was continued for 1 hour. At this time, the ratio of monomers present in the system is styrene / N-phenylmaleimide / acrylonitrile = 80 /
It is 10/10% by weight. Then deionized water 9000
g, polyvinyl alcohol-based suspension agent 4.06 g, polyacrylic acid ester-based suspension agent 4.06 g, and sodium sulfate 54.0 g were added, and when the temperature reached 90 ° C., 1-tert-butyl azo-1-cyanocyclohexane 4 0.48g was added and it heated up to 110 degreeC over 4 hours. Then 2
The temperature was raised to 150 ° C. over time, and unreacted monomer was removed by steam distillation for 1 hour.

The amount of the removed monomer was 100 g, and the total amount was styrene or acrylonitrile. afterwards,
Further, 1456 g of aniline was added, an imidization reaction was carried out at 155 ° C. for 1 hour, and then the temperature of the polymerization system was immediately cooled to room temperature. The bead-shaped copolymer obtained was separated from water with a filter cloth, washed with water, and dried. The yield of beaded copolymer was 93.
It was 00 g. The beaded copolymer was kneaded and pelletized while being devolatilized by an extruder with a vent. The composition of the pellets was 66.2% by weight of styrene, 2.3% by weight of maleic anhydride, 27.8% by weight of N-phenylmaleimide and 3.7% by weight of acrylonitrile.

Comparative Example 2-4 4007 g of styrene and 134 g of maleic anhydride were placed in a 20 liter autoclave, and the temperature was raised to 110 ° C. while substituting with nitrogen while stirring. 802 g of maleic anhydride melted at 70 ° C. was continuously added to this system at the addition rate shown in Table 8 below, and bulk polymerization was performed at 110 ° C. for 220 minutes. The polymerization rate at the time of continuous addition completion was 55% by weight, and the content rate of the maleic anhydride residue in the SMA copolymer produced was 33% by weight.

[0066]

[Table 8]

N-phenylmaleimide 624 was added to this system.
g, acrylonitrile 3433g, terpinolene 1
5.6 g was added, the system temperature was lowered to 70 ° C., and stirring was continued for 1 hour. At this time, the ratio of monomers present in the system was styrene / N-phenylmaleimide / acrylonitrile = 3.
It is 5/10/55% by weight. Then deionized water 90
00 g, polyvinyl alcohol-based suspension agent 4.06 g, polyacrylic acid ester-based suspension agent 4.06 g, and sodium sulfate 54.0 g were added, and when the temperature reached 90 ° C, 1-tert-butyl azo-1-cyanocyclohexane 6 .24
g was added and the temperature was raised to 110 ° C. over 4 hours. Then, the temperature was raised to 150 ° C. over 2 hours, and unreacted monomer was removed by steam distillation for 1 hour.

The amount of the removed monomer was 350 g, and the total amount was styrene or acrylonitrile. afterwards,
Further, 888 g of aniline was added, an imidization reaction was carried out at 155 ° C. for 1 hour, and then the temperature of the polymerization system was immediately cooled to room temperature. The bead-shaped copolymer obtained was separated from water with a filter cloth, washed with water, and dried. The yield of beaded copolymer is 90.
It was 00 g. The beaded copolymer was kneaded and pelletized while being devolatilized by an extruder with a vent. The composition of the pellet was 42.9% by weight of styrene, 1.5% by weight of maleic anhydride, 21.9% by weight of N-phenylmaleimide and 33.7% by weight of acrylonitrile.

Comparative Example 2-5 3137 g of styrene and 105 g of maleic anhydride were placed in a 20-liter autoclave, and the temperature was raised to 110 ° C. while substituting nitrogen with stirring. 628 g of maleic anhydride dissolved at 70 ° C. was continuously added to this system at an addition rate shown in Table 9 below, and bulk polymerization was performed at 110 ° C. for 220 minutes. The polymerization rate at the time of continuous addition completion was 55% by weight, and the content rate of the maleic anhydride residue in the SMA copolymer produced was 33% by weight.

[0070]

[Table 9]

N-phenylmaleimide 2052 was added to this system.
g, acrylonitrile 3078g, terpinolene 1
7.1 g was added, the system temperature was lowered to 70 ° C., and stirring was continued for 1 hour. At this time, the ratio of monomers present in the system was styrene / N-phenylmaleimide / acrylonitrile = 2.
It is 5/30/45% by weight. Then deionized water 90
00 g, polyvinyl alcohol-based suspension agent 4.06 g, polyacrylic acid ester-based suspension agent 4.06 g, and sodium sulfate 54.0 g were added, and when the temperature reached 90 ° C, 1-tert-butyl azo-1-cyanocyclohexane 6 .84
g was added and the temperature was raised to 110 ° C. over 4 hours. Then, the temperature was raised to 150 ° C. over 2 hours, and unreacted monomer was removed by steam distillation for 1 hour.

The amount of the removed monomer was 350 g, and the total amount was styrene or acrylonitrile. afterwards,
Further, 695 g of aniline was added, an imidization reaction was carried out at 155 ° C. for 1 hour, and then the temperature of the polymerization system was immediately cooled to room temperature. The bead-shaped copolymer obtained was separated from water with a filter cloth, washed with water, and dried. The yield of beaded copolymer is 88.
It was 00 g. The beaded copolymer was kneaded and pelletized while being devolatilized by an extruder with a vent. The composition of the pellets was 33.9% by weight of styrene, 1.2% by weight of maleic anhydride, 34.4% by weight of N-phenylmaleimide and 30.5% by weight of acrylonitrile.

Comparative Example 2-6 2082 g of styrene and 70 g of maleic anhydride were placed in a 20 liter autoclave and the temperature was raised to 110 ° C. while substituting with nitrogen while stirring. 416 g of maleic anhydride melted at 70 ° C. was continuously added to this system at an addition rate shown in Table 10 below, and bulk polymerization was performed at 110 ° C. for 220 minutes. The polymerization rate at the time of continuous addition completion was 55% by weight, and the content rate of the maleic anhydride residue in the SMA copolymer produced was 33% by weight.

[0074]

[Table 10]

N-phenylmaleimide 3784 was added to this system.
g, acrylonitrile 2648g, terpinolene 1
8.9 g was added, the system temperature was lowered to 70 ° C., and stirring was continued for 1 hour. At this time, the ratio of monomers present in the system was styrene / N-phenylmaleimide / acrylonitrile = 1.
It is 5/50/35% by weight. Then deionized water 90
00 g, polyvinyl alcohol-based suspension agent 4.06 g, polyacrylic acid ester-based suspension agent 4.06 g, and sodium sulfate 54.0 g were added, and when the temperature reached 90 ° C., 1-tert-butyl azo-1-cyanocyclohexane 7 .54
g was added and the temperature was raised to 110 ° C. over 4 hours. Then, the temperature was raised to 150 ° C. over 2 hours, and unreacted monomer was removed by steam distillation for 1 hour.

The amount of the removed monomer was 280 g, and the total amount was styrene or acrylonitrile. afterwards,
Further, 461 g of aniline was added, an imidization reaction was carried out at 155 ° C. for 1 hour, and then the temperature of the polymerization system was immediately cooled to room temperature. The bead-shaped copolymer obtained was separated from water with a filter cloth, washed with water, and dried. The yield of the beaded copolymer is 87.
It was 00 g. The beaded copolymer was kneaded and pelletized while being devolatilized by an extruder with a vent. The composition of the pellets was 22.7% by weight of styrene, 0.8% by weight of maleic anhydride, 49.9% by weight of N-phenylmaleimide and 26.5% by weight of acrylonitrile.

Test pieces were prepared from the pellets obtained in the above Examples and Comparative Examples by injection molding, and the following physical properties were evaluated and shown in Tables 11 and 12. (1) Tensile strength, measured according to JIS K7113 method. Unit is kg / c
m ² . (2) Tensile elongation, measured according to JIS K7113 method. The unit is%. (3) Izod impact strength, measured according to JIS K7110 method (with notch). The unit is kg-cm / cm ² .

(4) Melt flow index, JIS K7210 method (temperature 240 ° C., load 10 kg)
Measured according to. The unit is g / 10 minutes. (5) Vicat softening point, measured according to JIS K7206 method (load 5 kg).
The unit is ° C. (6) Content of N-phenylmaleimide in polymer, unit is% by weight. In Tables 11 and 12, this item name is simply referred to as the phenylmaleimide content.

[0079]

[Table 11]

[0080]

[Table 12]

FIG. 1 of the accompanying drawings shows that, in the second step of the method of the present invention, three components to be subjected to suspension polymerization, that is, a vinyl aromatic compound monomer which has not reacted in the first step, is added in the second step. Is a triangular coordinate showing a preferred ratio of maleimide compound monomer consisting of vinyl cyan compound monomer and maleimide and / or N-substituted maleimide,
In the present invention, the above three components are especially in this triangular coordinate,
It is preferably within the range surrounded by the line connecting A, B, C and D.

In the above Examples and Comparative Examples, the heat resistant copolymers obtained in Examples 1 to 6 are totally excellent in mechanical strength represented by tensile strength and heat resistance represented by Vicat softening point. However, in FIG. 1, the circles shown in the range surrounded by ABC and D relate to Examples 1 to 6.

[0083]

According to the method of the present invention, a heat resistant copolymer having excellent mechanical strength and heat resistance can be obtained.

[Brief description of drawings]

FIG. 1 shows a vinyl aromatic compound monomer, a vinyl cyanide compound monomer, and a maleimide-based monomer consisting of maleimide and / or N-substituted maleimide, which are subjected to suspension polymerization in the second step of the method of the present invention. Triangular coordinates indicating a preferable ratio of the three components.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-57-131213 (JP, A) JP-A-62-84502 (JP, A) JP-A-61-60705 (JP, A) JP-A-61- 53306 (JP, A) JP 61-16904 (JP, A) JP 59-93747 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08F 8/00-8 / 50

Claims (3)

(57) [Claims] 1. A method for producing a copolymer of maleimide and / or N-substituted maleimide, a vinyl aromatic compound and a vinyl cyan compound by a bulk-suspension polymerization method, which comprises: A vinyl aromatic compound-maleic anhydride monomer mixture containing 1 to 6% by weight is allowed to exist in the polymerization system, and maleic anhydride alone or a mixture of maleic anhydride and a vinyl aromatic compound monomer is added to the polymerization system. Polymerization proceeds with continuous addition, in which case the amount of maleic anhydride residue in the produced copolymer is controlled within the range of 20 to 40% by weight, and the conversion rate of the above monomers into the produced copolymer is controlled. But this first
First step of performing bulk polymerization until 30 to 70% by weight of the total charged monomers in the step polymerization system, (2) Next, in this polymerization system, a maleimide monomer and / or N-substituted maleimide monomer and vinyl are added. The second step of adding a cyan compound monomer, suspending the mixture in water, and copolymerizing the monomer in a suspended state, (3) Furthermore, in the copolymer chain produced in the first step. And a third step of imidizing the maleic anhydride residue contained in the above with a primary amine and / or ammonia. 2. In the second step, the vinyl aromatic compound monomer and / or maleimide monomer and / or N-substituted maleimide monomer and vinyl cyan compound which have not been reacted in the first step, which is subjected to suspension polymerization, are added. The composition ratio of the mixture with the monomer is the points A, B, C and D in the triangular coordinates shown in FIG. 1 (the positions of each point are as follows.
The numerical values are in order of the above-mentioned three kinds of monomers in% by weight.
1) within a portion surrounded by a line connecting
A method for producing the heat-resistant copolymer as described. A (76, 7, 17) B (50, 37, 13) C (18, 48, 34) D (46, 8, 46) 3. The heat resistant copolymer according to claim 1, wherein the vinyl aromatic compound monomer is styrene, the N-substituted maleimide monomer is N-phenylmaleimide, and the vinyl cyan compound monomer is acrylonitrile. Polymer production method.