阅读说明：本技术 马来酰亚胺系共聚物、其制造方法、树脂组合物以及射出成型体 (Maleimide copolymer, method for producing same, resin composition, and injection molded article ) 是由 中西崇一朗 松本真典 西野广平 于 2020-07-07 设计创作，主要内容包括：本发明的课题是提供马来酰亚胺系共聚物、其制造方法、以及使用了马来酰亚胺系共聚物的树脂组合物。该马来酰亚胺系共聚物含有芳香族乙烯基单体单元40～60质量％、氰化乙烯基单体单元5～20质量％、马来酰亚胺单体单元35～50质量％、以及可与这些单体单元共聚的单体单元0～10质量％,其玻璃化转变温度为165℃以上,在265℃、98N负荷的条件下的熔体质量流动速率为25～80g/10分钟,通过使用这样的马来酰亚胺系共聚物,可在不降低耐热赋予性的情况下提高流动性。(The invention provides a maleimide copolymer, a method for producing the same, and a resin composition using the maleimide copolymer. The maleimide copolymer comprises 40-60 mass% of aromatic vinyl monomer unit, 5-20 mass% of vinyl cyanide monomer unit, 35-50 mass% of maleimide monomer unit and 0-10 mass% of monomer unit copolymerizable with these monomer units, has a glass transition temperature of 165 ℃ or higher, and has a melt mass flow rate of 25-80 g/10 min under load of 265 ℃ and 98N.)

1. A maleimide copolymer having a glass transition temperature of 165-200 ℃ and a melt mass flow rate of 25-80 g/10 min under a load of 265 ℃ and 98N measured by a method described in JIS K7210.

2. The maleimide-based copolymer according to claim 1, which comprises 40 to 59.5% by mass of an aromatic vinyl monomer unit, 5 to 20% by mass of a vinyl cyanide monomer unit, and 35 to 50% by mass of a maleimide monomer unit.

3. The maleimide-based copolymer according to claim 1 or 2, further comprising a dicarboxylic anhydride monomer unit in an amount of 0.5 to 10% by mass.

4. The maleimide-based copolymer according to any one of claims 1 to 3, wherein the content of residual maleimide monomer is less than 300 ppm.

5. The method for producing a maleimide-based copolymer according to any one of claims 1 to 4, which comprises the steps of,

an initial polymerization step of mixing all the charge amounts of the vinyl cyanide monomer, 10 to 90 mass% of the charge amount of the aromatic vinyl monomer and 0 to 30 mass% of the charge amount of the unsaturated dicarboxylic anhydride monomer to initiate copolymerization;

a middle-stage polymerization step of adding 50 to 90 mass% of the remaining aromatic vinyl monomer and the remaining unsaturated dicarboxylic anhydride monomer in portions or continuously while continuing copolymerization;

a final polymerization step of adding the whole amount of the remaining aromatic vinyl monomer to obtain a copolymer having an aromatic vinyl monomer unit, a vinyl cyanide monomer unit and a dicarboxylic anhydride monomer unit; and

and an imidization step of imidizing the dicarboxylic anhydride monomer units of the obtained copolymer into maleimide monomer units using ammonia or a primary amine.

6. A resin composition comprising 5 to 40% by mass of the maleimide-based copolymer according to any one of claims 1 to 4 and 60 to 95% by mass of a resin selected from 1 or 2 or more of an acrylonitrile-butadiene-styrene copolymer resin, an acrylonitrile-styrene-acrylic rubber copolymer resin, an acrylonitrile-ethylene-propylene rubber-styrene copolymer resin and a styrene-acrylonitrile copolymer resin.

7. An injection-molded article comprising the resin composition according to claim 6.

8. The injection-molded article according to claim 7, which is used as an interior part or an exterior part of an automobile.

Background

Acrylonitrile-butadiene-styrene copolymer resins (ABS resins) have excellent mechanical strength, appearance, chemical resistance, moldability, etc., and are widely used in the fields of automobiles, home appliances, OA equipment, housing materials, daily necessities, etc. For applications requiring heat resistance such as automobile interior materials, ABS resins containing maleimide copolymers are also used as heat resistance imparting agents (for example, patent documents 1 and 2).

However, ABS resins containing maleimide copolymers have a drawback of low chemical resistance, and in order to overcome this drawback, maleimide copolymers obtained by copolymerizing vinyl cyanide monomers have been proposed (for example, patent documents 3 and 4). Copolymers obtained by copolymerizing vinyl cyanide monomers, which have been proposed so far, have high heat resistance, but there is still a strong demand for further improvement in fluidity.

Documents of the prior art

Patent document

Patent document 1 Japanese patent laid-open publication No. 57-98536

Patent document 2 Japanese laid-open patent publication No. 57-125242

Patent document 3 Japanese laid-open patent application No. 2004-339280

Patent document 4, Japanese patent laid-open No. 2007-9228

Disclosure of Invention

Problems to be solved by the invention

The present invention addresses the problem of providing a maleimide copolymer which can give a resin composition having excellent flowability while maintaining a balance among chemical resistance, heat resistance and impact resistance, and a method for producing the maleimide copolymer. Also disclosed is a resin composition which is obtained by kneading and mixing a maleimide copolymer with 1 or 2 or more resins selected from an ABS resin, an acrylonitrile-styrene-acrylic rubber copolymer resin (ASA resin), an acrylonitrile-ethylene-propylene rubber-styrene copolymer resin (AES resin) and a styrene-acrylonitrile copolymer resin (SAN resin), and which has an excellent balance between chemical resistance, heat resistance and impact resistance and high fluidity.

Means for solving the problems

In the present invention, when a maleimide-based copolymer having a high glass transition temperature and high fluidity is used, the viscosity of the resin composition can be reduced without increasing the amount of the maleimide-based copolymer added to the resin composition, and this contributes to the speeding up of molding and the improvement of productivity.

That is, the present invention has the following points.

(1) A maleimide copolymer comprising an aromatic vinyl monomer unit, a vinyl cyanide monomer unit, and a maleimide monomer unit, wherein the maleimide copolymer has a glass transition temperature of 165 to 200 ℃ and a melt mass flow rate of 25 to 80g/10 min under a load of 265 ℃ and 98N measured according to the method described in JIS K7210.

(2) The maleimide-based copolymer according to (1), which comprises 40 to 59.5% by mass of an aromatic vinyl monomer unit, 5 to 20% by mass of a vinyl cyanide monomer unit and 35 to 50% by mass of a maleimide monomer unit.

(3) The maleimide-based copolymer according to (1) or (2), further comprising 0.5 to 10 mass% of a dicarboxylic anhydride monomer unit.

(4) The maleimide-based copolymer according to any one of (1) to (3), wherein the residual maleimide monomer content is less than 300 ppm.

(5) The method for producing a maleimide-based copolymer according to any one of (1) to (4), comprising an initial polymerization step of mixing and initiating copolymerization of all the charge amounts of the vinyl cyanide monomer, 10 to 90% by mass of the charge amount of the aromatic vinyl monomer and 0 to 30% by mass of the charge amount of the unsaturated dicarboxylic anhydride monomer; a middle-stage polymerization step of adding 50 to 90 mass% of the remaining aromatic vinyl monomer and the remaining unsaturated dicarboxylic anhydride monomer in portions or continuously while continuing copolymerization; a final polymerization step of adding the whole amount of the remaining aromatic vinyl monomer to obtain a copolymer having an aromatic vinyl monomer unit, a vinyl cyanide monomer unit and a dicarboxylic anhydride monomer unit; and an imidization step of imidizing the dicarboxylic anhydride monomer units of the copolymer to maleimide monomer units using ammonia or a primary amine.

(6) A resin composition comprising 5 to 40% by mass of the maleimide-based copolymer of any one of (1) to (4) and 60 to 95% by mass of a resin selected from 1 or 2 or more of ABS resin, ASA resin, AES resin and SAN resin.

(7) An injection-molded article comprising the resin composition according to (6).

(8) The injection-molded article according to (7), which is used as an interior part or an exterior part of an automobile.

Effects of the invention

According to the present invention, a maleimide-based copolymer which can give a resin composition having excellent fluidity while maintaining a balance among chemical resistance, heat resistance imparting property and impact resistance, and a process for producing the maleimide-based copolymer can be obtained. Further, a resin composition which is obtained by kneading and mixing a maleimide copolymer and 1 or 2 or more resins selected from an ABS resin, an ASA resin, an AES resin and a SAN resin and has an excellent balance among chemical resistance, heat resistance and impact resistance and high fluidity can be obtained.

Detailed Description

< description of terms >

In the present specification, for example, the description "a to B" means a range from a to B.

The embodiments of the present invention will be described in detail below. The maleimide-based copolymer of the present invention comprises an aromatic vinyl monomer unit, a vinyl cyanide monomer unit, and a maleimide monomer unit.

Aromatic vinyl monomers which can be used for the maleimide copolymer are used for improving the hue of the resin composition, and examples thereof include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2, 4-dimethylstyrene, ethylstyrene, p-tert-butylstyrene, α -methylstyrene, and α -methyl-p-methylstyrene. Among them, styrene having a good effect of improving hue is preferable. The aromatic vinyl monomers may be used alone or in combination of 2 or more.

The amount of the aromatic vinyl monomer unit contained in the maleimide-based copolymer is preferably 40 to 59.5% by mass, and more preferably 45 to 55% by mass. Specifically, for example, 40, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, and 59.5% by mass may be in the range between any 2 numerical values exemplified here. When the amount of the aromatic vinyl monomer unit is 40% by mass or more, the hue of the obtained resin composition does not yellow, and when it is 59.5% by mass or less, the heat resistance of the obtained resin composition can be improved.

Vinyl cyanide monomers useful for the maleimide-based copolymer are used to improve chemical resistance of the resin composition, and examples thereof include acrylonitrile, methacrylonitrile, ethacrylonitrile, and fumaronitrile. Among them, acrylonitrile having a high effect of improving chemical resistance is preferable. The vinyl cyanide monomer may be used alone or in combination of 2 or more.

The amount of the vinyl cyanide monomer unit contained in the maleimide-based copolymer is preferably 5 to 20% by mass, more preferably 7 to 15% by mass. Specifically, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, and 20% by mass may be in the range between any 2 values exemplified here. When the amount of the vinyl cyanide monomer unit is 5% by mass or more, the chemical resistance of the obtained resin composition is improved, and when the amount is 20% by mass or less, the hue of the obtained resin composition does not yellow.

The maleimide monomer which can be used for the maleimide copolymer is useful for improving the heat resistance of the resin composition, and examples thereof include N-alkylmaleimides such as N-methylmaleimide, N-butylmaleimide and N-cyclohexylmaleimide, and N-phenylmaleimide, N-chlorophenylmaleimide, N-methylphenylmaleimide, N-methoxyphenylmaleimide and N-tribromophenylmaleimide. Among them, N-phenylmaleimide which is excellent in the effect of improving heat resistance is preferable. The maleimide monomer may be used alone or in combination of 2 or more. In order to contain the maleimide monomer unit in the maleimide-based copolymer, an aromatic vinyl monomer, a vinyl cyanide monomer and a maleimide monomer may be copolymerized. Further, the dicarboxylic anhydride monomer units derived from an unsaturated dicarboxylic anhydride monomer of a copolymer obtained by copolymerizing an aromatic vinyl monomer, a vinyl cyanide monomer and an unsaturated dicarboxylic anhydride monomer described later may be imidized with ammonia or a primary amine.

The amount of the maleimide monomer unit contained in the maleimide copolymer is preferably 35 to 50% by mass, more preferably 37 to 45% by mass. Specifically, for example, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50% by mass may be in the range between any 2 values exemplified here. When the amount of the maleimide monomer unit is 35% by mass, the heat resistance of the resulting maleimide-based copolymer is improved, and when it is 50% by mass, the impact strength of the resulting maleimide-based copolymer is not lowered.

The maleimide copolymer may contain a dicarboxylic anhydride monomer unit having an effect of improving the compatibility of the maleimide copolymer with other resins. In order to introduce the dicarboxylic anhydride monomer unit into the maleimide-based copolymer, an unsaturated dicarboxylic anhydride monomer may be copolymerized together with the above-mentioned monomers, or the imidization ratio may be adjusted so as to leave the dicarboxylic anhydride monomer unit when a copolymer obtained by copolymerizing the above-mentioned aromatic vinyl monomer with a vinyl cyanide monomer and an unsaturated dicarboxylic anhydride monomer is imidized. Examples of the unsaturated dicarboxylic anhydride monomer include maleic anhydride, itaconic anhydride, citraconic anhydride, and aconitic anhydride. Among them, maleic anhydride having a high effect of improving compatibility is preferably used. The unsaturated dicarboxylic anhydride monomer may be used alone or in combination of 2 or more.

The amount of the dicarboxylic anhydride monomer unit contained in the maleimide-based copolymer is preferably 0.5 to 10% by mass, more preferably 0.1 to 2% by mass. Specifically, for example, the content is 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 2, 3, 4, 5, 6, 7, 8, 9, 10% by mass, and may be in a range between any 2 values exemplified here. When the amount of the dicarboxylic anhydride monomer unit is 0.5% by mass or more, the compatibility of the obtained maleimide-based copolymer with a resin such as ABS is improved, and when the amount is 10% by mass or less, the thermal stability of the obtained resin composition is improved.

The maleimide-based copolymer may be copolymerized with a copolymerizable monomer other than the aromatic vinyl monomer, vinyl cyanide monomer, maleimide monomer and unsaturated dicarboxylic anhydride monomer within a range not to impair the effect of the present invention. Examples of the monomer copolymerizable with the maleimide-based copolymer include acrylate monomers such as methyl acrylate, ethyl acrylate, and butyl acrylate; methacrylate monomers such as methyl methacrylate and ethyl methacrylate; vinyl carboxylic acid monomers such as acrylic acid and methacrylic acid; acrylic acid amides and methacrylic acid amides. The monomer copolymerizable with the maleimide-based copolymer may be used alone or in combination of 2 or more.

The amount of residual maleimide monomer contained in the maleimide-based copolymer is preferably less than 300ppm, more preferably less than 230ppm, still more preferably less than 200 ppm. By making the residual maleimide monomer amount less than 300ppm, the hue of the resulting resin composition is more favorable.

The residual maleimide monomer amount is a value measured under the conditions described below.

Device name gas chromatograph GC-2010 (Shimadzu Kagaku Co., Ltd.)

Column capillary column DB-5ms (manufactured by Agilent technologies Co., Ltd.)

The temperature is 280 ℃ at the injection port and 280 ℃ at the detector

The temperature rise analysis was carried out at a column temperature of 80 deg.C (initial stage).

(temperature rise analysis conditions) 80 ℃ for 12 minutes

Heating at 80-280 deg.C for 10 min at 20 deg.C/min

Keeping at 280 deg.C for 10 min

Detector FID

Step (5 ml) of a 1, 2-dichloroethane solution (0.014g/L) containing undecane (an internal standard substance) was dissolved in 0.5g of the sample. Thereafter, 5ml of n-hexane was added thereto, and the mixture was shaken for 10 to 15 minutes with a shaker to precipitate the crystals. Only the supernatant liquid was injected into the gas chromatograph in a state where the polymer was precipitated and precipitated. From the peak area of the obtained maleimide monomer, a quantitative value was calculated using a coefficient obtained from an internal standard substance.

The glass transition temperature of the maleimide-based copolymer is from 165 to 200 ℃, preferably from 170 to 200 ℃, and more preferably from 175 to 185 ℃, from the viewpoint of efficiently improving the heat resistance of a resin to be kneaded and mixed, such as an ABS resin or an ASA resin. Specifically, for example, 165, 170, 175, 176, 177, 178, 179, 180, 185, 190, 195, and 200 ℃, and may be in a range between any 2 values exemplified herein. The glass transition temperature is a measured value measured under the measurement conditions described below using DSC.

Device name differential scanning calorimeter Robot DSC6200 (manufactured by Seiko instruments Co., Ltd.)

The temperature rise speed is 10 ℃/min

In order to raise the glass transition temperature of the maleimide-based copolymer, the content of maleimide monomer units contained in the maleimide-based copolymer may be increased, or another monomer having a higher glass transition temperature may be copolymerized.

The melt mass flow rate of the maleimide-based copolymer is 25 to 80g/10 min as measured at 265 ℃ under a load of 98N according to the method described in JIS K7210. Specifically, for example, the concentration is 25, 26, 27, 28, 29, 30, 35, 40, 45, 50, 60, 65, 70, 75, 80g/10 min, and may be in a range between any 2 values exemplified herein. If the amount is less than 25g/10 min, the fluidity of the mixed resin is lowered, and if the amount is more than 80g/10 min, the impact resistance is lowered.

In order to decrease the melt mass flow rate of the maleimide-based copolymer, the content of the dicarboxylic anhydride monomer units contained in the maleimide-based copolymer may be increased, or other monomers having a lower melt mass flow rate may be copolymerized.

Examples of the polymerization method of the maleimide copolymer include solution polymerization and bulk polymerization. From the viewpoint that a maleimide-based copolymer having a more uniform copolymerization composition can be obtained by polymerization while adding it in portions, solution polymerization is preferred. The solvent for the solution polymerization is preferably a non-polymerizable solvent from the viewpoint of not causing by-products and causing little adverse effect, and examples thereof include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and acetophenone; ethers such as tetrahydrofuran and 1, 4-dioxane; aromatic hydrocarbons such as benzene, toluene, xylene, and chlorobenzene; n, N-dimethylformamide, dimethylsulfoxide and N-methyl-2-pyrrolidone, and methyl ethyl ketone and methyl isobutyl ketone are preferable from the viewpoint of ease of removal of the solvent when recovering the maleimide copolymer by devolatilization. As the polymerization process, a continuous polymerization type, a batch type (batch type) and a semi-batch type are applicable.

The method for polymerizing the maleimide copolymer is not particularly limited, but it is preferably obtained by radical polymerization, and the polymerization temperature is preferably in the range of 80 to 150 ℃. The polymerization initiator is not particularly limited, and for example, known azo compounds such as azobisisobutyronitrile, azobiscyclohexanecarbonitrile, azobismethylpropionitrile and azobismethylbutyronitrile; well-known organic peroxides such as benzoyl peroxide, t-butyl peroxybenzoate, 1-bis (t-butylperoxy) -3, 3, 5-trimethylcyclohexane, t-butyl peroxyisopropyl monocarbonate, t-butyl peroxy2-ethylhexanoate, di-t-butyl peroxide, dicumyl peroxide, and ethyl 3, 3-di (t-butylperoxy) butyrate, and 1 of these or 2 or more of these can be used in combination. From the viewpoint of controlling the reaction rate and polymerization rate of the polymerization, it is preferable to use an azo compound or an organic peroxide having a 10-hour half-life of 70 to 120 ℃. The amount of the polymerization initiator used is not particularly limited, but is preferably 0.1 to 1.5% by mass, more preferably 0.1 to 1.0% by mass, based on 100% by mass of the total monomer units. When the amount of the polymerization initiator used is 0.1% by mass or more, a sufficient polymerization rate can be obtained, and when the amount is 1.5% by mass or less, the polymerization reaction can be easily controlled, and a maleimide-based copolymer having a target weight average molecular weight can be easily obtained.

The weight average molecular weight of the maleimide-based copolymer is 5 to 30 ten thousand, preferably 5 to 20 ten thousand. Specifically, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, and 30 thousands, and may be within a range between any 2 numerical values exemplified here. When the weight average molecular weight is 5 ten thousand or less, impact resistance is lowered, and when it exceeds 30 ten thousand, fluidity is lowered.

Chain transfer agents may be used in the production of the maleimide copolymer. The chain transfer agent to be used is not particularly limited, and examples thereof include n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, α -methylstyrene dimer, ethyl thioglycolate, limonene and terpinolene. The amount of the chain transfer agent to be used is not particularly limited as long as the target weight average molecular weight of the maleimide-based copolymer can be obtained, but is preferably 0.01 to 0.8% by mass, more preferably 0.1 to 0.5% by mass, based on 100% by mass of the total monomers to be copolymerized. When the amount of the chain transfer agent used is 0.01 to 0.8 mass%, a maleimide-based copolymer having a target weight average molecular weight can be easily obtained.

As a method for introducing a maleimide monomer unit into a maleimide-based copolymer, there is a method of copolymerizing a maleimide monomer with another monomer (direct method); or a method in which an unsaturated dicarboxylic anhydride monomer, an aromatic vinyl monomer, and a vinyl cyanide monomer are copolymerized in advance, and then the dicarboxylic anhydride monomer units in the copolymer are converted into maleimide monomer units by imidization with ammonia or a primary amine (post-imidization method). The post-imidization method is preferable because the amount of residual maleimide monomer in the copolymer is small.

Examples of the primary amines include alkylamines such as methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, n-pentylamine, n-hexylamine, n-octylamine, cyclohexylamine, and decylamine, and chlorine-or bromine-substituted alkylamines; aromatic amines such as aniline, toluidine and naphthylamine, and among them, aniline and cyclohexylamine are preferable. These primary amines may be used alone or in combination of 2 or more. The amount of the primary amine to be added is not particularly limited, but is preferably 0.7 to 1.1 molar equivalents, and more preferably 0.85 to 1.05 molar equivalents, relative to the dicarboxylic anhydride monomer unit. It is preferable that the amount of the dicarboxylic anhydride monomer unit in the maleimide-based copolymer is 0.7 molar equivalent or more because the thermal stability is good. Further, it is preferably 1.1 molar equivalent or less because the amount of the primary amine remaining in the maleimide-based copolymer decreases.

When the maleimide monomer unit is introduced by the post-imidization method, a catalyst may be used as needed for the purpose of improving the dehydration ring-closure reaction in the reaction of ammonia or a primary amine with the dicarboxylic anhydride monomer unit in the copolymer, particularly in the reaction of converting the dicarboxylic anhydride monomer unit into the maleimide monomer unit. The kind of the catalyst is not particularly limited, and for example, tertiary amine can be used. The tertiary amine is not particularly limited, and examples thereof include trimethylamine, triethylamine, tripropylamine, tributylamine, N, N-dimethylaniline and N, N-diethylaniline. The amount of the tertiary amine added is not particularly limited, but is preferably 0.01 molar equivalent or more relative to the dicarboxylic anhydride monomer unit. In the present invention, the temperature of the imidization reaction is preferably 100 to 250 ℃, and more preferably 120 to 200 ℃. When the temperature of the imidization reaction is 100 ℃ or higher, the reaction rate is sufficiently high, and it is preferable from the viewpoint of productivity. It is preferable that the temperature of the imidization reaction is 250 ℃ or lower because a decrease in physical properties due to thermal deterioration of the maleimide-based copolymer can be suppressed.

When the polymerization is carried out by the post-imidization method, the aromatic vinyl monomer, the vinyl cyanide monomer and the unsaturated dicarboxylic anhydride monomer may all be charged at the initial stage of the polymerization to carry out the polymerization, but the aromatic vinyl monomer and the unsaturated dicarboxylic anhydride monomer are consumed at the initial stage of the polymerization because of their strong alternating copolymerizability, and a copolymer having a large amount of vinyl cyanide monomer units is easily formed at the later stage of the polymerization. As a result, the resulting maleimide-based copolymer may have poor hue or a large composition distribution, and may have insufficient solubility during kneading and mixing with an ABS resin or the like, resulting in poor physical properties. Therefore, in order to obtain a maleimide-based copolymer having a good hue and a small composition distribution, the following steps are preferably performed.

An initial polymerization step of mixing all the vinyl cyanide monomer charge amounts, 10 to 90 mass% of the aromatic vinyl monomer charge amount, and 0 to 30 mass% of the unsaturated dicarboxylic anhydride monomer charge amount, and charging the mixture at the initial polymerization stage to initiate copolymerization.

And a middle-stage polymerization step of continuously copolymerizing while adding the remaining amount of the aromatic vinyl monomer and the remaining amount of the unsaturated dicarboxylic anhydride monomer in portions or continuously.

A final polymerization step of adding 1/10 or more of the amount of the aromatic vinyl monomer added in a batch or continuous manner after the completion of the entire amount of the unsaturated dicarboxylic anhydride monomer, and polymerizing the mixture.

An imidization step of imidizing the obtained copolymer having an aromatic vinyl monomer unit, a vinyl cyanide monomer unit and a dicarboxylic anhydride monomer unit with ammonia or a primary amine to obtain a maleimide-based copolymer.

As a method for removing volatile components such as a solvent and an unreacted monomer used for solution polymerization (devolatilization method) from a solution after completion of solution polymerization or a solution after completion of post-imidization of a maleimide-based copolymer, a known method can be used. For example, a vacuum devolatilizer with a heater or a devolatilizer extruder with an outlet port may be used. The devolatilized maleimide-based copolymer in a molten state may be transferred to a granulating step, extruded linearly from a multi-hole die, and processed into pellets by a cold cutting method, an in-air hot cutting method, or an underwater hot cutting method.

The maleimide-based copolymer thus obtained can be used as a heat resistance imparting agent for a resin composition obtained by kneading and mixing the maleimide-based copolymer with various resins. The various resins are not particularly limited, and include ABS resins, ASA resins, AES resins, and SAN resins. The maleimide copolymer has excellent compatibility with these resins, and therefore, a high heat resistance imparting effect can be obtained. The mixing ratio of the maleimide copolymer to the resin is preferably 5 to 40 mass% of the maleimide copolymer; 60 to 95 mass% of 1 or more resins selected from ABS resin, ASA resin, AES resin and SAN resin, more preferably 10 to 30 mass% of maleimide copolymer; 70-90% by mass of 1 or more resins selected from ABS resin, ASA resin, AES resin and SAN resin.

When the blending ratio of the maleimide-based copolymer is within this range, the effect of improving the heat resistance of the resin composition can be obtained without lowering the chemical resistance and the hue of the resin composition.

The method for kneading and mixing the maleimide copolymer with various resins is not particularly limited, and a known melt kneading technique can be used. Examples of melt kneading apparatuses that can be suitably used include a single screw extruder, a fully-intermeshing co-rotating twin screw extruder, a fully-intermeshing counter-rotating twin screw extruder, a screw extruder such as a non-or incompletely-intermeshing twin screw extruder, a banbury mixer, a kneader, and a mixing roll.

When the maleimide copolymer is kneaded and mixed with these resins, a stabilizer, an ultraviolet absorber, a flame retardant, a plasticizer, a lubricant, glass fibers, an inorganic filler, a colorant, an antistatic agent, and the like may be further added.

The resin composition is suitable for use in injection molded articles because of its excellent flowability.

Examples of the injection molded article include housings/exterior materials for televisions, copiers, telephones, clocks, refrigerators, sweepers, air conditioners, washing machines, PCs, DVD/blu-ray players, stereos, dryers, keyboards, tablet computers, digital cameras, briefcases, pachinko machines, home game machines, other electric appliances, and the like, instrument boxes, instrument panels, registers, control switches, console boxes, bumper fascia, roof rails, signs, instrument panel trims, electronic housings, wheel covers, fenders, door handles, door panels, rear mirrors, rear lamp covers, front lamp covers, roof spoilers, rear spoilers, antenna covers, front grilles, radiator grilles, center consoles, car audio systems, car navigation systems, other interior and exterior materials for automobiles, roof members, window frames, door covers, door handles, fence members, system racks, and the like, A drain board, a toilet seat, a window frame, a cosmetic panel, a toilet table, a lattice enclosure, a terrace, a bench, and other housing parts, a food tray, a toy, a sports apparatus, furniture, a musical instrument, a semiconductor transport container, a plasma dust collection unit, and other commodity parts. Among them, the resin composition is suitable for automotive interior and exterior materials requiring high heat resistance, and is suitable for large injection molded articles such as lamp covers and spoilers because of its excellent fluidity.

Examples

The following examples are given to illustrate details of the present invention, but the present invention is not limited to the following examples.

< production example of maleimide-based copolymer (A-1) >

An autoclave having a capacity of about 120 liters and equipped with a stirrer was charged with 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 part by mass of tert-butyl 2-ethylhexanoate peroxide, 0.6 part by mass of α -methylstyrene dimer, and 12 parts by mass of methyl ethyl ketone, and after the gas phase portion was replaced with nitrogen gas, the temperature was raised to 92 ℃ over 40 minutes under stirring. After the temperature was raised, the mixture was kept at 92 ℃ and a solution prepared by dissolving 31 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl peroxy-2-ethylhexanoate in 75 parts by mass of methyl ethyl ketone and 28 parts by mass of styrene were continuously added over 7 hours. Then, 6 parts by mass of styrene was continuously added over 2 hours after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 1 hour. Then, 20.3 parts by mass of aniline and 0.3 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 7 hours. The imidization reaction solution after the completion of the reaction was fed into a vented screw extruder, and volatile components were removed to obtain a granular maleimide-based copolymer A-1. The analysis results of the resulting maleimide-based copolymer are shown in table 1.

< production example of maleimide-based copolymer (A-2) >

An autoclave having a capacity of about 120 liters and equipped with a stirrer was charged with 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 part by mass of tert-butyl 2-ethylhexanoate peroxide, 0.6 part by mass of α -methylstyrene dimer, and 12 parts by mass of methyl ethyl ketone, and after the gas phase portion was replaced with nitrogen gas, the temperature was raised to 92 ℃ over 40 minutes under stirring. After the temperature was raised, the mixture was kept at 92 ℃ and a solution prepared by dissolving 25 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl peroxy-2-ethylhexanoate in 75 parts by mass of methyl ethyl ketone and 28 parts by mass of styrene were continuously added over 7 hours. Then, 2 parts by mass of styrene was continuously added over 2 hours after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 1 hour. Thereafter, 17.7 parts by mass of aniline and 0.3 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 7 hours. The imidization reaction solution after the completion of the reaction was fed into a vented screw extruder, and volatile components were removed to obtain a granular maleimide-based copolymer A-2. The analysis results of the resulting maleimide-based copolymer are shown in table 1.

< production example of maleimide-based copolymer (A-3) >

An autoclave having a capacity of about 120 liters and equipped with a stirrer was charged with 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 part by mass of tert-butyl 2-ethylhexanoate peroxide, 0.6 part by mass of α -methylstyrene dimer, and 12 parts by mass of methyl ethyl ketone, and after the gas phase portion was replaced with nitrogen gas, the temperature was raised to 92 ℃ over 40 minutes under stirring. After the temperature was raised, the mixture was kept at 92 ℃ and a solution prepared by dissolving 35 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl peroxy-2-ethylhexanoate in 75 parts by mass of methyl ethyl ketone and 28 parts by mass of styrene were continuously added over 7 hours. Then, 2 parts by mass of styrene was continuously added over 2 hours after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 1 hour. Thereafter, 21.3 parts by mass of aniline and 0.3 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 7 hours. The imidization reaction solution after the completion of the reaction was fed into a vented screw extruder, and volatile components were removed to obtain a granular maleimide-based copolymer A-3. The analysis results of the resulting maleimide-based copolymer are shown in table 1.

< production example of maleimide-based copolymer (A-4) >

An autoclave having a capacity of about 120 liters and equipped with a stirrer was charged with 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 part by mass of tert-butyl 2-ethylhexanoate peroxide, 0.6 part by mass of α -methylstyrene dimer, and 12 parts by mass of methyl ethyl ketone, and after the gas phase portion was replaced with nitrogen gas, the temperature was raised to 92 ℃ over 40 minutes under stirring. After the temperature was raised, the mixture was kept at 92 ℃ and a solution prepared by dissolving 24 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl peroxy-2-ethylhexanoate in 75 parts by mass of methyl ethyl ketone and 28 parts by mass of styrene were continuously added over 7 hours. Then, 13 parts by mass of styrene was continuously added over 2 hours after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 1 hour. Thereafter, 17.4 parts by mass of aniline and 0.3 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 7 hours. The imidization reaction solution after the completion of the reaction was fed into a vented screw extruder, and volatile components were removed to obtain a granular maleimide-based copolymer A-4. The analysis results of the resulting maleimide-based copolymer are shown in table 1.

< production example of maleimide-based copolymer (A-5) >

An autoclave having a capacity of about 120 liters and equipped with a stirrer was charged with 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 part by mass of tert-butyl 2-ethylhexanoate peroxide, 0.8 part by mass of α -methylstyrene dimer, and 12 parts by mass of methyl ethyl ketone, and after the gas phase portion was replaced with nitrogen gas, the temperature was raised to 92 ℃ over 40 minutes under stirring. After the temperature was raised, the mixture was kept at 92 ℃ and a solution prepared by dissolving 31 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl peroxy-2-ethylhexanoate in 75 parts by mass of methyl ethyl ketone and 28 parts by mass of styrene were continuously added over 7 hours. Then, 6 parts by mass of styrene was continuously added over 2 hours after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 1 hour. Then, 19.8 parts by mass of aniline and 0.3 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 7 hours. The imidization reaction solution after the completion of the reaction was fed into a vented screw extruder, and volatile components were removed to obtain a granular maleimide-based copolymer A-5. The analysis results of the resulting maleimide-based copolymer are shown in table 1.

< production example of maleimide-based copolymer (A-6) >

An autoclave having a capacity of about 120 liters and equipped with a stirrer was charged with 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 part by mass of tert-butyl 2-ethylhexanoate peroxide, 0.11 part by mass of α -methylstyrene dimer, and 12 parts by mass of methyl ethyl ketone, and after the gas phase portion was replaced with nitrogen gas, the temperature was raised to 92 ℃ over 40 minutes under stirring. After the temperature was raised, the mixture was kept at 92 ℃ and a solution prepared by dissolving 31 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl peroxy-2-ethylhexanoate in 75 parts by mass of methyl ethyl ketone and 28 parts by mass of styrene were continuously added over 7 hours. Then, 6 parts by mass of styrene was continuously added over 2 hours after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 1 hour. Then, 20.7 parts by mass of aniline and 0.3 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 7 hours. The imidization reaction solution after the completion of the reaction was fed into a vented screw extruder, and volatile components were removed to obtain a granular maleimide-based copolymer A-6. The analysis results of the resulting maleimide-based copolymer are shown in table 1.

< production example of maleimide-based copolymer (A-7) >

An autoclave having a capacity of about 120 liters and equipped with a stirrer was charged with 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 part by mass of tert-butyl 2-ethylhexanoate peroxide, 0.6 part by mass of α -methylstyrene dimer, and 12 parts by mass of methyl ethyl ketone, and after the gas phase portion was replaced with nitrogen gas, the temperature was raised to 92 ℃ over 40 minutes under stirring. After the temperature was raised, the mixture was kept at 92 ℃ and a solution prepared by dissolving 31 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl peroxy-2-ethylhexanoate in 75 parts by mass of methyl ethyl ketone and 28 parts by mass of styrene were continuously added over 7 hours. Then, 6 parts by mass of styrene was continuously added over 2 hours after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 1 hour. Thereafter, 17.2 parts by mass of aniline and 0.3 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 7 hours. The imidization reaction solution after the completion of the reaction was fed into a vented screw extruder, and volatile components were removed to obtain a granular maleimide-based copolymer A-7. The analysis results of the resulting maleimide-based copolymer are shown in table 1.

< production example of maleimide-based copolymer (A-8) >

An autoclave having a capacity of about 120 liters and equipped with a stirrer was charged with 20 parts by mass of styrene, 15 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 part by mass of tert-butyl 2-ethylhexanoate peroxide, 0.6 part by mass of α -methylstyrene dimer, and 12 parts by mass of methyl ethyl ketone, and after the gas phase portion was replaced with nitrogen gas, the temperature was raised to 92 ℃ over 40 minutes under stirring. After the temperature was raised, the mixture was kept at 92 ℃ and a solution prepared by dissolving 31 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl peroxy-2-ethylhexanoate in 75 parts by mass of methyl ethyl ketone and 28 parts by mass of styrene were continuously added over 7 hours. Then, after the end of the addition of maleic anhydride, 1 part by mass of styrene was continuously added over 2 hours. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 1 hour. Then, 19.8 parts by mass of aniline and 0.3 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 7 hours. The imidization reaction solution after the completion of the reaction was fed into a vented screw extruder, and volatile components were removed to obtain a granular maleimide-based copolymer A-8. The analysis results of the resulting maleimide-based copolymer are shown in table 1.

< production example of Maleimide-based copolymer (B-1) >

An autoclave having a capacity of about 120 liters and equipped with a stirrer was charged with 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 part by mass of tert-butyl 2-ethylhexanoate peroxide, 0.01 part by mass of α -methylstyrene dimer, and 12 parts by mass of methyl ethyl ketone, and after the gas phase portion was replaced with nitrogen gas, the temperature was raised to 92 ℃ over 40 minutes under stirring. After the temperature was raised, the mixture was kept at 92 ℃ and a solution prepared by dissolving 31 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl peroxy-2-ethylhexanoate in 75 parts by mass of methyl ethyl ketone and 28 parts by mass of styrene were continuously added over 7 hours. Then, 6 parts by mass of styrene was continuously added over 2 hours after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 1 hour. Then, 20.3 parts by mass of aniline and 0.3 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 7 hours. The imidization reaction solution after the completion of the reaction was fed into a vented screw extruder, and volatile components were removed to obtain a granular maleimide-based copolymer B-1. The analysis results of the maleimide-based copolymer B-1 are shown in Table 1.

< production example of Maleimide-based copolymer (B-2) >

An autoclave having a capacity of about 120 liters and equipped with a stirrer was charged with 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 part by mass of tert-butyl 2-ethylhexanoate peroxide, 0.01 part by mass of α -methylstyrene dimer, and 12 parts by mass of methyl ethyl ketone, and after the gas phase portion was replaced with nitrogen gas, the temperature was raised to 92 ℃ over 40 minutes under stirring. After the temperature was raised, the mixture was kept at 92 ℃ and a solution prepared by dissolving 27 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl peroxy-2-ethylhexanoate in 75 parts by mass of methyl ethyl ketone and 28 parts by mass of styrene were continuously added over 7 hours. Then, 10 parts by mass of styrene was continuously added over 2 hours after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 1 hour. Then, 18.9 parts by mass of aniline and 0.3 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 7 hours. The imidization reaction solution after the completion of the reaction was fed into a vented screw extruder, and volatile components were removed to obtain a granular maleimide-based copolymer B-2. The analysis results of the maleimide-based copolymer B-2 are shown in Table 1.

< production example of Maleimide-based copolymer (B-3) >

An autoclave having a capacity of about 120 liters and equipped with a stirrer was charged with 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 part by mass of tert-butyl 2-ethylhexanoate peroxide, 0.6 part by mass of α -methylstyrene dimer, and 12 parts by mass of methyl ethyl ketone, and after the gas phase portion was replaced with nitrogen gas, the temperature was raised to 92 ℃ over 40 minutes under stirring. After the temperature was raised, the mixture was kept at 92 ℃ and a solution prepared by dissolving 20 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl peroxy-2-ethylhexanoate in 75 parts by mass of methyl ethyl ketone and 28 parts by mass of styrene were continuously added over 7 hours. Then, after the end of the addition of maleic anhydride, 17 parts by mass of styrene was continuously added over 2 hours. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 1 hour. Thereafter, 13.3 parts by mass of aniline and 0.3 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 7 hours. The imidization reaction solution after the completion of the reaction was fed into a vented screw extruder, and volatile components were removed to obtain a granular maleimide-based copolymer B-3. The analysis results of the maleimide-based copolymer B-3 are shown in Table 1.

< production example of maleimide-based copolymer (B-4) >

An autoclave having a capacity of about 120 liters and equipped with a stirrer was charged with 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 part by mass of tert-butyl 2-ethylhexanoate peroxide, 0.6 part by mass of α -methylstyrene dimer, and 12 parts by mass of methyl ethyl ketone, and after the gas phase portion was replaced with nitrogen gas, the temperature was raised to 92 ℃ over 40 minutes under stirring. After the temperature was raised, the mixture was kept at 92 ℃ and a solution prepared by dissolving 31 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl peroxy-2-ethylhexanoate in 75 parts by mass of methyl ethyl ketone and 28 parts by mass of styrene were continuously added over 7 hours. Then, 6 parts by mass of styrene was continuously added over 2 hours after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 1 hour. Then, 16.6 parts by mass of aniline and 0.3 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 7 hours. The imidization reaction solution after the completion of the reaction was fed into a vented screw extruder, and volatile components were removed to obtain a granular maleimide-based copolymer B-4. The analysis results of the maleimide-based copolymer B-4 are shown in Table 1.

< production example of Maleimide-based copolymer (B-5) >

An autoclave having a capacity of about 120 liters and equipped with a stirrer was charged with 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 part by mass of tert-butyl 2-ethylhexanoate peroxide, 0.9 part by mass of α -methylstyrene dimer, and 12 parts by mass of methyl ethyl ketone, and after the gas phase portion was replaced with nitrogen gas, the temperature was raised to 92 ℃ over 40 minutes under stirring. After the temperature was raised, the mixture was kept at 92 ℃ and a solution prepared by dissolving 31 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl peroxy-2-ethylhexanoate in 75 parts by mass of methyl ethyl ketone and 28 parts by mass of styrene were continuously added over 7 hours. Then, 6 parts by mass of styrene was continuously added over 2 hours after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 1 hour. Then, 19.8 parts by mass of aniline and 0.3 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 7 hours. The imidization reaction solution after the completion of the reaction was fed into a vented screw extruder, and volatile components were removed to obtain a granular maleimide-based copolymer B-5. The analysis results of the maleimide-based copolymer B-5 are shown in Table 2.

< production example of maleimide-based copolymer (B-6) >

An autoclave having a capacity of about 120 liters and equipped with a stirrer was charged with 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 part by mass of tert-butyl 2-ethylhexanoate peroxide, 0.9 part by mass of α -methylstyrene dimer, and 12 parts by mass of methyl ethyl ketone, and after the gas phase portion was replaced with nitrogen gas, the temperature was raised to 92 ℃ over 40 minutes under stirring. After the temperature was raised, the mixture was kept at 92 ℃ and a solution prepared by dissolving 27 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl peroxy-2-ethylhexanoate in 75 parts by mass of methyl ethyl ketone and 28 parts by mass of styrene were continuously added over 7 hours. Then, 10 parts by mass of styrene was continuously added over 2 hours after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 1 hour. Then, 18.4 parts by mass of aniline and 0.3 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 7 hours. The imidization reaction solution after the completion of the reaction was fed into a vented screw extruder, and volatile components were removed to obtain a granular maleimide-based copolymer B-6. The analysis results of the maleimide-based copolymer B-6 are shown in Table 2.

< production example of maleimide-based copolymer (B-7) >

An autoclave having a capacity of about 120 liters and equipped with a stirrer was charged with 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 part by mass of tert-butyl 2-ethylhexanoate peroxide, 0.6 part by mass of α -methylstyrene dimer, and 12 parts by mass of methyl ethyl ketone, and after the gas phase portion was replaced with nitrogen gas, the temperature was raised to 92 ℃ over 40 minutes under stirring. After the temperature was raised, the mixture was kept at 92 ℃ and a solution prepared by dissolving 31 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl peroxy-2-ethylhexanoate in 75 parts by mass of methyl ethyl ketone and 28 parts by mass of styrene were continuously added over 7 hours. Then, 6 parts by mass of styrene was continuously added over 2 hours after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 1 hour. Thereafter, 12.6 parts by mass of aniline and 0.2 parts by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 7 hours. The imidization reaction solution after the completion of the reaction was fed into a vented screw extruder, and volatile components were removed to obtain a granular maleimide-based copolymer A-1. The analysis results of the resulting maleimide-based copolymer are shown in table 1.

TABLE 1

TABLE 2

(weight average molecular weight)

The weight average molecular weight is a polystyrene equivalent value measured by Gel Permeation Chromatography (GPC) under the following conditions.

Device name SYSTEM-21Shodex (manufactured by Showa Denko K.K.)

Column 3 PL gel MIXED-B were connected in series

The temperature is 40 DEG C

Detecting the differential refractive index

Solvent tetrahydrofuran

Concentration 2% by mass

Standard curve was prepared using standard Polystyrene (PS) (manufactured by PL).

(melt Mass flow Rate: MFR)

The melt mass flow rate was measured according to JIS K7210 under the conditions of 265 ℃ and 98N load.

(glass transition temperature)

Glass transition temperature the glass transition mid-point temperature (Tmg) of the maleimide-based copolymer was measured in accordance with JIS K-7121 using the following apparatus and measurement conditions.

Name of the apparatus Robot DSC6200 (manufactured by Seiko instruments Co., Ltd.)

The temperature rise speed is 10 ℃/min

(residual Maleimide monomer amount)

0.5g of the sample was dissolved in 5ml of a 1, 2-dichloroethane solution (0.014g/L) containing undecane (an internal standard substance). Thereafter, 5ml of n-hexane was added thereto, and the mixture was shaken with a shaker for 10 to 15 minutes to precipitate. Only the supernatant liquid was injected into the gas chromatograph in a state where the polymer was precipitated and precipitated. From the peak area of the obtained maleimide monomer, a quantitative value was calculated using a coefficient obtained from an internal standard substance.

Device name gas chromatograph GC-2010 (Shimadzu Kagaku Co., Ltd.)

Column capillary column DB-5ms (manufactured by Agilent technologies Co., Ltd.)

The temperature is 280 ℃ at the injection port and 280 ℃ at the detector

The temperature rise analysis was carried out at a column temperature of 80 deg.C (initial stage).

(temperature rise analysis conditions) 80 ℃ for 12 minutes

Heating at 80-280 deg.C for 10 min at 20 deg.C/min

Keeping at 280 deg.C for 10 min

Detector FID

< examples and comparative examples >

Examples 1 to 8 and comparative examples 1 to 6 (kneading and mixing of maleimide copolymer and ABS resin)

Maleimide-based copolymers A-1 to A-8 and B-1 to B-6, and a general commercially available maleimide-based copolymer having no vinyl cyanide monomer unit, "MS-NIP" (manufactured by Denka corporation), were mixed with ABS resin "GR-3000" (manufactured by Denka corporation) or ASA resin "Luran S757G" (manufactured by INEOS Styrolysis) at the compounding ratios shown in tables 3 and 4, and then extruded and pelletized using a twin screw extruder (TEM-35B manufactured by Toshiba mechanical Co., Ltd.). Using the pellets, test pieces were produced by an injection molding machine, and the respective physical property values were measured. The results are shown in tables 3 and 4.

TABLE 3

TABLE 4

(Charpy impact strength)

A notched test piece was used in accordance with JIS K-7111, and the hitting direction was measured by edge hitting at a relative humidity of 50% and an ambient temperature of 23 ℃. The measuring instrument used was a digital impact tester manufactured by Toyo Seiki Seisaku-Sho.

(Vicat softening point)

According to JIS K7206, the measurement was carried out by a 50 method (load 50N, temperature rise rate 50 ℃/hr) using a test piece having a thickness of 10 mm. times.10 mm and a thickness of 4 mm. The measurement instrument used was an HDT & VSPT test apparatus manufactured by toyoyo seiko co.

(melt Mass flow Rate: MFR)

The measurement was carried out at 220 ℃ under a load of 98N in accordance with JIS K7210.

(chemical resistance)

Cracks were observed at 23 ℃ for 48 hours by an 1/4 ellipsometry method using a specimen shape of 316X 20X 2mm, a long radius of 250mm and a short radius of 150 mm. In order to eliminate the influence of the molding strain, the pellets were press-molded at 260 ℃ and cut to produce test pieces. Toluene was used as the chemical agent.

The critical strain is obtained by using the following equation.

ε＝b/2a²{1-(a²-b²)X²/a⁴}^1.5×t×100

Critical strain epsilon, long radius a, short radius b, test piece thickness t and crack generation point X

Chemical resistance was evaluated from the critical strain according to the following criteria.

0.8 or more excellent, 0.6 to 0.7. delta. 0.3 to 0.5. X0.2 or less

As shown in examples 1 to 8, the maleimide-based copolymers of A-1 to A-8 of the present invention achieve a high glass transition temperature and a high melt mass flow rate by reducing the weight average molecular weight without reducing the content of maleimide monomer units in the composition. However, as shown in comparative examples 5 and 6, when the weight average molecular weight is reduced by a certain amount or more, heat resistance and chemical resistance are reduced. The maleimide-based copolymers of B-1 to B-6 which do not satisfy the scope of the present invention are not within the scope of the present invention, and the resin compositions of comparative examples 1 to 6 obtained by kneading and mixing these maleimide-based copolymers with an ABS resin are inferior in all of impact resistance, fluidity, heat resistance and chemical resistance.

Industrial applicability

The maleimide copolymer of the present invention can provide a resin composition having an excellent balance of chemical resistance, heat resistance, impact resistance and fluidity by kneading and mixing an ABS resin, an ASA resin, an AES resin and a SAN resin which are compatible with each other, and can improve the fluidity of the resin mixture, thereby increasing the speed of molding and the production speed.