阅读说明：本技术 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 (Maleimide copolymer, method for producing same, and resin composition using maleimide copolymer ) 是由 松原达宏 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具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25～50质量％、二羧酸酐单体单元0.1～10质量％,玻璃化转变温度为165℃以上,1分子共聚物中含有的二羧酸酐单体单元为1～30个。另外提供一种树脂组合物,其是将马来酰亚胺系共聚物和选自ABS树脂、ASA树脂、AES树脂或SAN树脂中的1种或2种以上的树脂混炼混合而得到的,其表面光泽性、耐热性、耐冲击性、流动性的物性平衡优异。(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 units, 5-20 mass% of vinyl cyanide monomer units, 25-50 mass% of maleimide monomer units, 0.1-10 mass% of dicarboxylic anhydride monomer units, and has a glass transition temperature of 165 ℃ or higher, and 1-30 dicarboxylic anhydride monomer units contained in 1-molecule copolymer. Also disclosed is a resin composition which is obtained by kneading and mixing a maleimide copolymer and 1 or 2 or more resins selected from ABS resins, ASA resins, AES resins and SAN resins, and which has an excellent balance among surface gloss, heat resistance, impact resistance and fluidity.)

1. A maleimide copolymer comprising 40 to 60 mass% of an aromatic vinyl monomer unit, 5 to 20 mass% of a vinyl cyanide monomer unit, 25 to 50 mass% of a maleimide monomer unit, and 0.1 to 10 mass% of a dicarboxylic anhydride monomer unit,

the glass transition temperature of the maleimide copolymer is 165-200 ℃, and the average value of dicarboxylic anhydride monomer units contained in 1 molecule copolymer is 1-30.

2. The method for producing a maleimide-based copolymer according to claim 1, which comprises the steps of,

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

a middle-stage polymerization process: respectively adding 50-90 mass% of the residual amount of the aromatic vinyl monomer and the residual amount of the unsaturated dicarboxylic anhydride monomer in batches or continuously, and simultaneously continuing copolymerization;

final stage polymerization step: adding the whole of the remaining amount of the 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: the dicarboxylic anhydride monomer units of the resulting copolymer are imidized to maleimide monomer units using ammonia or a primary amine.

3. A resin composition comprising 5 to 40 mass% of the maleimide-based copolymer according to claim 1 and 60 to 95 mass% of a resin,

the resin is 1 or more than 2 selected from acrylonitrile-butadiene-styrene copolymer resin, acrylonitrile-styrene-acrylic rubber copolymer resin, acrylonitrile-ethylene-propylene rubber-styrene copolymer resin or styrene-acrylonitrile copolymer resin.

4. An injection-molded article comprising the resin composition according to claim 3.

5. The injection-molded article according to claim 4, which is used as an interior part or an exterior part of an automobile.

Technical Field

The present invention relates to a maleimide copolymer, a method for producing the same, and a resin composition using the maleimide copolymer.

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, an ABS resin (heat-resistant ABS) containing a maleimide copolymer is also used as a heat resistance imparting agent (for example, patent documents 1 and 2).

For the purpose of further imparting chemical resistance to heat-resistant ABS, heat resistance imparting agents obtained by copolymerizing maleimide copolymers and vinyl cyanide monomers have been proposed (for example, patent documents 3 and 4). These heat resistance imparting agents have no problem in ordinary use. However, when a mixed resin of a heat resistance-imparting agent and ABS is injection-molded, the surface gloss of the resulting injection-molded article may be reduced depending on the conditions.

Documents of the prior art

Patent document

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

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

Patent document 3: japanese patent laid-open publication No. 2004-339280

Patent document 4: japanese patent laid-open publication No. 2007-9228

Disclosure of Invention

Problems to be solved by the invention

The invention provides a maleimide copolymer which can obtain a molded body with high surface gloss while maintaining impact resistance, heat resistance and fluidity, and a method for producing the imide copolymer. Further, the present invention provides a resin composition obtained by kneading and mixing a maleimide copolymer and 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), which resin composition can provide a molded article having high surface gloss while maintaining impact resistance, heat resistance, and fluidity.

Means for solving the problems

That is, the present invention has the following gist.

(1) A maleimide copolymer comprising 40 to 60 mass% of an aromatic vinyl monomer unit, 5 to 20 mass% of a vinyl cyanide monomer unit, 25 to 50 mass% of a maleimide monomer unit, and 0.1 to 10 mass% of a dicarboxylic anhydride monomer unit, wherein the maleimide copolymer has a glass transition temperature of 165 to 200 ℃, and the average number of dicarboxylic anhydride monomer units contained in 1 molecule of the copolymer is 1 to 30.

(2) The method for producing a maleimide-based copolymer according to (1), comprising the steps of,

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

a middle-stage polymerization process: respectively adding 50-90 mass% of the residual amount of the aromatic vinyl monomer and the residual amount of the unsaturated dicarboxylic anhydride monomer in batches or continuously, and simultaneously continuing copolymerization;

final stage polymerization step: adding the whole of the remaining amount of the 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.

(3) A resin composition comprising 5 to 40 mass% of the maleimide copolymer of (1) and 60 to 95 mass% of a resin selected from 1 or 2 or more of ABS resin, ASA resin, AES resin and SAN resin.

(4) An injection-molded article comprising the resin composition as described in (3).

(5) The injection-molded article according to (4), which is used as an interior part or an exterior part of an automobile.

Effects of the invention

The present invention provides a maleimide copolymer which can give a molded article having a high surface gloss while maintaining impact resistance, heat resistance and fluidity, and a process 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 ASA resin, an AES resin and a SAN resin, and which can give a molded article having a high surface gloss while maintaining impact resistance, heat resistance and fluidity.

Detailed Description

< description of terms >

In the present specification, the expression "a to B" means a to B.

The maleimide-based copolymer of the present invention includes not only a maleimide-based copolymer obtained by copolymerizing an aromatic vinyl monomer, a vinyl cyanide monomer, a maleimide monomer and an unsaturated dicarboxylic anhydride monomer, but also a maleimide-based copolymer obtained by copolymerizing an aromatic vinyl monomer, a vinyl cyanide monomer and an unsaturated dicarboxylic anhydride monomer and then imidizing a dicarboxylic anhydride monomer unit derived from the unsaturated dicarboxylic anhydride monomer in the molecule using ammonia or a primary amine.

The aromatic vinyl monomer used in the maleimide-based copolymer is a monomer 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 40 to 60% by mass, preferably 45 to 55% by mass. Specifically, for example, 40, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, and 60% by mass may be in the range between any 2 values exemplified here. If the amount of the aromatic vinyl monomer unit is less than 40% by mass, the hue of the resin composition is yellowish, and if it exceeds 60% by mass, the heat resistance of the resin composition is lowered.

The vinyl cyanide monomer used for the maleimide-based copolymer is a monomer for improving 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 5 to 20% by mass, preferably 7 to 15% by mass. Specifically, for example, the content is 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 20% by mass, and may be in a range between any 2 values exemplified here. If the amount of the vinyl cyanide monomer unit is less than 5% by mass, the effect of improving the chemical resistance of the resin composition is not obtained, and if it exceeds 20% by mass, the color of the resin composition is yellowish.

The maleimide monomer which can be used for the maleimide copolymer is a monomer 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, 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.

The amount of the maleimide monomer unit contained in the maleimide copolymer is 25 to 50% by mass, preferably 37 to 45% by mass. Specifically, for example, the content is 25, 30, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50 mass%, and may be in a range between any 2 numerical values exemplified here. If the amount of the maleimide monomer unit is less than 25% by mass, the effect of improving the heat resistance of the resin composition is not obtained, and if it exceeds 50% by mass, the impact strength of the resin composition is lowered.

The unsaturated dicarboxylic anhydride monomer used for the maleimide-based copolymer is a monomer for improving the compatibility of the maleimide-based copolymer with the ABS resin or the like, and examples thereof include maleic anhydride, itaconic anhydride, citraconic anhydride and aconitic anhydride. Among them, maleic anhydride is preferable from the viewpoint of compatibility with ABS resin and the like. 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 0.1 to 10% by mass, preferably 0.1 to 5% by mass, and 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. If the amount of the dicarboxylic anhydride monomer unit is less than 0.1% by mass, the effect of improving the compatibility with the ABS resin or the like cannot be obtained, and if it is more than 10% by mass, the thermal stability of the resin composition is lowered.

The content ratio of the aromatic vinyl monomer unit, vinyl cyanide monomer unit, maleimide monomer unit and dicarboxylic anhydride monomer unit contained in the maleimide copolymer is determined by¹³C-NMR is a value measured under the following measurement conditions.

Device name: FT-NMR AVANCE300 (manufactured by BRUKER)

Solvent: deuterated chloroform

Concentration: 14% by mass

Temperature: 25 deg.C

And (4) accumulating times: 10000 times

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 in the range of 5 to 30 ten thousand, the difference in melt viscosity between the resin and an acrylonitrile-butadiene-styrene copolymer resin, an acrylonitrile-styrene-acrylic rubber copolymer resin, an acrylonitrile-ethylene-propylene rubber-styrene copolymer resin, a styrene-acrylonitrile copolymer resin, or the like, which will be described later, is small, and the dispersibility between the resin and the resin is excellent.

The average number of the dicarboxylic anhydride monomer units contained in 1 molecule of the maleimide copolymer is 1 to 30, preferably 1 to 20, and more preferably 4 to 15. Specifically, for example, 1, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, and 30 may be included, and any 2 values exemplified herein may be included. If the average number of the dicarboxylic anhydride monomer units is less than 1, the effect of reacting the dicarboxylic anhydride monomer units with another resin having an amino group or an alcohol group terminal to function as a compatibilizer is reduced, and if it exceeds 30, a crosslinked product may be formed by reaction with, for example, a metal salt derived from emulsion polymerization or an amine used as an additive.

In order to increase the average value of the dicarboxylic anhydride monomer units contained in 1 molecule of the maleimide-based copolymer, the weight average molecular weight may be increased or the amount of the dicarboxylic anhydride monomer units contained in the maleimide-based copolymer may be increased.

The average value of the dicarboxylic anhydride monomer units contained in 1 molecule of the maleimide-based copolymer was measured by the following method.

(1. measurement of weight average molecular weight)

First, the weight average molecular weight of the maleimide-based copolymer was measured by GPC under the following measurement conditions.

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

Column: connecting 3 PL gel MIXED-B in series

Temperature: 40 deg.C

And (3) detection: differential refractive index

Solvent: tetrahydrofuran (THF)

Concentration: 0.8% by mass

Standard curve: the drawing was performed using standard Polystyrene (PS) (manufactured by PL).

(2. amount of dicarboxylic anhydride monomer units)

Next, the content of the dicarboxylic anhydride monomer units contained in the maleimide-based copolymer was determined by colorimetric titration (indicator: phenolphthalein) of a methyl ethyl ketone solution of the maleimide-based copolymer based on a 0.1N ethanolic potassium hydroxide solution.

A: mass (g) of the maleimide-based copolymer

B: blank value (mL) of volume of the dropwise added alcoholic potassium hydroxide solution

C: volume of the EtOH solution (mL) added dropwise

D: molar mass of dicarboxylic anhydride monomer units

The content (mass%) of the dicarboxylic anhydride monomer unit contained in the maleimide-based copolymer can be determined by the following formula (1).

(C-B)×D/A/100…(1)

(3.1 average value of dicarboxylic anhydride monomer units in molecule)

From the weight average molecular weight (E) and the content (F) of the dicarboxylic anhydride monomer units contained in the maleimide-based copolymer determined above, the average value of the dicarboxylic anhydride monomer units in 1 molecule of the maleimide-based copolymer can be determined according to the following formula (2).

E×F/D/100…(2)

The maleimide-based copolymer of the present invention can also be obtained by: the above aromatic vinyl monomer, vinyl cyanide monomer and unsaturated dicarboxylic anhydride monomer are copolymerized, and then the dicarboxylic anhydride monomer unit in the copolymer is imidized with ammonia or primary amine to be converted into a maleimide monomer unit (post-imidization method).

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 molar equivalent of the dicarboxylic anhydride monomer unit in the maleimide-based copolymer is 0.7 or more because the resulting resin composition has good thermal stability. Further, it is preferably 1.1 molar equivalent or less because the amount of the primary amine remaining in the maleimide-based copolymer decreases.

In the reaction of ammonia or a primary amine with a dicarboxylic anhydride monomer unit, particularly in the reaction of converting the dicarboxylic anhydride monomer unit into a maleimide monomer unit, a catalyst may be used as necessary for the purpose of improving the dehydration ring-closure reaction in order to obtain a maleimide copolymer. The kind of the catalyst is not particularly limited, and for example, tertiary amine can be used. Examples of the tertiary amine 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.

In order to obtain the maleimide copolymer, the aromatic vinyl monomer, the vinyl cyanide monomer and the unsaturated dicarboxylic anhydride monomer may be all charged at the initial stage of polymerization to be polymerized, but since the aromatic vinyl monomer and the unsaturated dicarboxylic anhydride monomer have a high alternating copolymerization property, the aromatic vinyl monomer and the unsaturated dicarboxylic anhydride monomer are consumed at the initial stage of polymerization, and a copolymer having a large amount of vinyl cyanide monomer units is easily formed at the latter stage of polymerization. As a result, the resulting maleimide-based copolymer may have poor hue or a large composition distribution, and may have insufficient compatibility with ABS resin or the like during kneading and mixing, resulting in poor physical properties of the resulting resin composition. Therefore, in order to obtain a maleimide-based copolymer having a good hue and a small (uniform) composition distribution, a production method having the following steps is preferably used.

An initial polymerization step: the entire charge amount of vinyl cyanide monomer, 10-90 mass% of aromatic vinyl monomer and 0-30 mass% of unsaturated dicarboxylic anhydride monomer are mixed, and fed in the initial stage of polymerization to initiate copolymerization.

A middle-stage polymerization process: the residual amount of the aromatic vinyl monomer and the residual amount of the unsaturated dicarboxylic anhydride monomer are added in portions or continuously while continuing the copolymerization, respectively.

Final stage polymerization step: after the completion of the entire charge of the unsaturated dicarboxylic anhydride monomer, 1/10 or more, which is a batch or continuous addition amount of the aromatic vinyl monomer, is added to the mixture to carry out polymerization.

An imidization step: the obtained copolymer is imidized 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 from a solution after completion of the imidization step of the maleimide-based copolymer (devolatilization method), 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 glass transition temperature of the maleimide-based copolymer is preferably from 165 to 200 ℃, more preferably from 170 to 200 ℃, and still more preferably from 175 to 185 ℃, from the viewpoint of effectively improving the heat resistance of the 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 the glass transition midpoint temperature (Tmg) of the maleimide-based copolymer measured by the following apparatus and measurement conditions in accordance with JIS K-7121.

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

Temperature rise rate: 10 ℃/min

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

The maleimide-based copolymer may be copolymerized with a copolymerizable monomer other than the aromatic vinyl monomer, vinyl cyanide 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 maleimide monomers such as N-alkylmaleimides, e.g., N-methylmaleimide, N-butylmaleimide and N-cyclohexylmaleimide, N-phenylmaleimide, N-chlorophenylmaleimide, N-methylphenylmaleimide, N-methoxyphenylmaleimide and N-tribromophenylmaleimide; acrylic ester monomers such as methyl acrylate, ethyl acrylate and butyl acrylate, methacrylic ester monomers such as methyl methacrylate and ethyl methacrylate, vinyl carboxylic acid monomers such as acrylic acid and methacrylic acid, acrylic acid amide and methacrylic acid amide, and the like. The monomer copolymerizable with the maleimide-based copolymer may be used alone or in combination of 2 or more.

Examples of the polymerization method of the maleimide-based copolymer include solution polymerization and bulk polymerization. From the viewpoint that the maleimide-based copolymer having a uniform copolymerization composition can be obtained by polymerization while adding the comonomer in portions or continuously, solution polymerization is preferred. The solvent for the solution polymerization is preferably a non-polymerizable solvent, and ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and acetophenone are preferable from the viewpoint of less adverse effects and less by-products; ether like such as tetrahydrofuran and 1, 4-dioxane; aromatic hydrocarbons such as benzene, toluene, xylene, and chlorobenzene; n, N-dimethylformamide, dimethylsulfoxide, N-methyl-2-pyrrolidone, and the like, 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, and is preferably 0.1 to 1.5 parts by mass, more preferably 0.1 to 1.0 part by mass, per 100 parts by mass of all monomers used for polymerization. The amount of the polymerization initiator used is preferably 0.1 part by mass or more because a sufficient polymerization rate can be obtained. When the amount of the polymerization initiator used is 1.5 parts by mass or less, the polymerization rate can be suppressed, so that the reaction can be easily controlled and the target molecular weight can be easily obtained.

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 molecular weight can be obtained, but is preferably 0.01 to 0.8 parts by mass, more preferably 0.1 to 0.5 parts by mass, per 100 parts by mass of all monomers used for polymerization. When the amount of the chain transfer agent used is 0.01 to 0.8 part by mass, the target molecular weight can be easily obtained.

The maleimide-based copolymer thus obtained can be used as a heat resistance imparting agent for the resin composition obtained by kneading and mixing it with various resins. The various resins are not particularly limited, and examples thereof 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 these resins is preferably 5 to 40 mass% of the maleimide copolymer, 60 to 95 mass% of 1 or more resins selected from the group consisting of ABS resin, ASA resin, AES resin and SAN resin, more preferably 10 to 30 mass% of the maleimide copolymer, and 70 to 90 mass% of 1 or more resins selected from the group consisting of 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 method for obtaining a molded article from the resin composition may employ known molding techniques, for example, injection molding, extrusion molding, sheet molding, and press molding. The resin composition of the present invention is particularly excellent in heat resistance, and is particularly suitable for use as a material for injection molding which attains high temperature and high pressure during molding.

The molded article obtained by molding the resin composition is suitably used for automobile interior parts, exterior parts, and the like.

Examples

The following examples are given for the purpose of illustrating the invention, but the invention is not limited to the 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, 0.025 parts by mass of α -methylstyrene dimer, and 12 parts by mass of methyl isobutyl 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 23 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl 2-ethylhexanoate peroxide in 50 parts by mass of methyl isobutyl ketone and 28 parts by mass of styrene were continuously added over 4.5 hours. Then, 14 parts by mass of styrene was continuously added over 0.5 hour after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 0.5 hour. Thereafter, 26.6 parts by mass of aniline and 0.5 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 6 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 maleimide-based copolymer A-1 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, 11 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 part by mass of tert-butyl 2-ethylhexanoate peroxide, 0.025 parts by mass of α -methylstyrene dimer, and 12 parts by mass of methyl isobutyl 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 2-ethylhexanoate peroxide in 50 parts by mass of methyl isobutyl ketone and 28 parts by mass of styrene were continuously added over 4.5 hours. Then, after the end of the addition of maleic anhydride, 9 parts by mass of styrene was continuously added over 0.5 hour. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 0.5 hour. Then, 30.0 parts by mass of aniline and 0.5 parts by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 6 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 maleimide-based copolymer A-2 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, 0.025 parts by mass of α -methylstyrene dimer, and 12 parts by mass of methyl isobutyl 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 23 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl 2-ethylhexanoate peroxide in 50 parts by mass of methyl isobutyl ketone and 28 parts by mass of styrene were continuously added over 4.5 hours. Then, 14 parts by mass of styrene was continuously added over 0.5 hour after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 0.5 hour. Then, 26.6 parts by mass of aniline and 0.5 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 8 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 maleimide-based copolymer A-3 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, 0.4 part by mass of α -methylstyrene dimer, and 12 parts by mass of methyl isobutyl 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 23 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl 2-ethylhexanoate peroxide in 50 parts by mass of methyl isobutyl ketone and 28 parts by mass of styrene were continuously added over 4.5 hours. Then, 14 parts by mass of styrene was continuously added over 0.5 hour after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 0.5 hour. Thereafter, 26.6 parts by mass of aniline and 0.5 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 6 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 maleimide-based copolymer A-4 thus obtained 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, 0.6 part by mass of α -methylstyrene dimer, and 12 parts by mass of methyl isobutyl 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 23 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl 2-ethylhexanoate peroxide in 50 parts by mass of methyl isobutyl ketone and 28 parts by mass of styrene were continuously added over 4.5 hours. Then, 14 parts by mass of styrene was continuously added over 0.5 hour after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 0.5 hour. Then, 26.6 parts by mass of aniline and 0.5 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 7.5 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 maleimide-based copolymer A-5 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, and 12 parts by mass of methyl isobutyl ketone, and after the gas phase portion was replaced with nitrogen gas, the temperature was raised to 92 ℃ over 40 minutes with stirring. After the temperature was raised, the mixture was kept at 92 ℃ and a solution prepared by dissolving 23 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl 2-ethylhexanoate peroxide in 50 parts by mass of methyl isobutyl ketone and 28 parts by mass of styrene were continuously added over 4.5 hours. Then, 14 parts by mass of styrene was continuously added over 0.5 hour after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 0.5 hour. Thereafter, 26.6 parts by mass of aniline and 0.5 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 6 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 maleimide-based copolymer A-6 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, 0.05 part by mass of α -methylstyrene dimer, and 12 parts by mass of methyl isobutyl 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 23 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl 2-ethylhexanoate peroxide in 50 parts by mass of methyl isobutyl ketone and 28 parts by mass of styrene were continuously added over 4.5 hours. Then, 14 parts by mass of styrene was continuously added over 0.5 hour after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 0.5 hour. Then, 26.6 parts by mass of aniline and 0.5 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 5.5 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 maleimide-based copolymer A-7 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, 0.025 parts by mass of α -methylstyrene dimer, and 12 parts by mass of methyl isobutyl 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 23 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl 2-ethylhexanoate peroxide in 50 parts by mass of methyl isobutyl ketone and 28 parts by mass of styrene were continuously added over 4.5 hours. Then, 14 parts by mass of styrene was continuously added over 0.5 hour after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 0.5 hour. Thereafter, 26 parts by mass of aniline and 0.5 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 5 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 2.

< 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, and 12 parts by mass of methyl isobutyl ketone, and after the gas phase portion was replaced with nitrogen gas, the temperature was raised to 92 ℃ over 40 minutes with stirring. After the temperature was raised, the mixture was kept at 92 ℃ and a solution prepared by dissolving 23 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl 2-ethylhexanoate peroxide in 50 parts by mass of methyl isobutyl ketone and 28 parts by mass of styrene were continuously added over 4.5 hours. Then, 14 parts by mass of styrene was continuously added over 0.5 hour after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 0.5 hour. Then, 17.8 parts by mass of aniline and 0.5 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 5 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 2.

< 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, 0.025 parts by mass of α -methylstyrene dimer, and 12 parts by mass of methyl isobutyl 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 23 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl 2-ethylhexanoate peroxide in 50 parts by mass of methyl isobutyl ketone and 28 parts by mass of styrene were continuously added over 4.5 hours. Then, 14 parts by mass of styrene was continuously added over 0.5 hour after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 0.5 hour. Then, 19 parts by mass of aniline and 0.5 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 6 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 2.

< 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, 0.025 parts by mass of α -methylstyrene dimer, and 12 parts by mass of methyl isobutyl 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 23 parts by mass of maleic anhydride and 0.22 part by mass of tert-butyl 2-ethylhexanoate peroxide in 50 parts by mass of methyl isobutyl ketone and 28 parts by mass of styrene were continuously added over 4.5 hours. Then, 14 parts by mass of styrene was continuously added over 0.5 hour after the end of the addition of maleic anhydride. After styrene was added, the temperature was raised to 120 ℃ to complete the polymerization within 0.5 hour. Then, 17.8 parts by mass of aniline and 0.5 part by mass of triethylamine were added to the polymerization solution, and the mixture was reacted at 140 ℃ for 5 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 2.

TABLE 1

TABLE 2

(weight average molecular weight)

The weight average molecular weight of the maleimide-based copolymer was measured by GPC under the following measurement conditions.

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

Column: connecting 3 PL gel MIXED-B in series

Temperature: 40 deg.C

And (3) detection: differential refractive index

Solvent: tetrahydrofuran (THF)

Concentration: 0.8% by mass

Standard curve: the drawing was performed using standard Polystyrene (PS) (manufactured by PL).

(glass transition temperature)

The glass transition mid-point temperature (Tmg) of the maleimide-based copolymer was measured according to JIS K-7121 using the following apparatus and measurement conditions.

Device name: robot DSC6200 (manufactured by Seiko instruments Co., Ltd.)

Temperature rise rate: 10 ℃/min

(1 dicarboxylic anhydride monomer units of Polymer in molecule)

First, the content of the dicarboxylic anhydride monomer units contained in the maleimide-based copolymer was measured in the following manner.

The content of the dicarboxylic anhydride monomer units contained in the maleimide-based copolymer was determined by colorimetric titration (indicator: phenolphthalein) of a methyl ethyl ketone solution of the maleimide-based copolymer based on a 0.1N ethanolic potassium hydroxide solution.

A: mass (g) of the maleimide-based copolymer

B: blank value (mL) of volume of the alcoholic potassium hydroxide solution added dropwise

C: volume of the EtOH Potassium hydroxide solution added dropwise (mL)

D: the molar mass of the dicarboxylic anhydride monomer units,

the content (mass%) of the dicarboxylic anhydride monomer unit contained in the maleimide-based copolymer was determined by the following formula.

The content ratio of the dicarboxylic anhydride monomer unit (F) ═ C-B). times.D/A/100

Then, the average value of the dicarboxylic anhydride monomer units in 1 molecule of the maleimide-based copolymer was calculated from the value of the weight average molecular weight (E) calculated as described above by the following formula.

1 molecule of maleimide copolymer, the average value of the dicarboxylic anhydride monomer units being E.times.F/D/100

< examples and comparative examples >

Examples 1 to 7 and comparative examples 1 to 4 (kneading and mixing of maleimide copolymer and ABS resin)

The maleimide-based copolymers A-1 to A-7 and B-1 to B-4 were mixed with a general commercially available ABS resin "GR-3000" (manufactured by Denka Co., Ltd.) in the blending 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 prepared 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)

According to JIS K-7111, notched specimens were used, and the striking direction was measured by side striking 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.

(gloss degree)

Measured at a measurement angle of 60 ℃ in accordance with JIS Z-8741. UGV-4D manufactured by Suga Test Instruments was used as the measuring instrument.

The maleimide-based copolymers A-1 to A-7 satisfying the scope of the present invention have a sufficiently small number of dicarboxylic anhydride monomer units contained in these copolymers and a sufficiently high glass transition temperature, and therefore the resin compositions of examples 1 to 7 obtained by kneading and mixing these maleimide-based copolymers with an ABS resin are excellent in impact resistance, flowability, heat resistance and surface gloss. Further, since the matrix resin of the ABS resin is an AS resin, the maleimide-based copolymer of the present invention is expected to provide the same effect AS the AS resin, AES resin using an AS resin AS the matrix resin, and ASA resin. On the other hand, the resin compositions of comparative examples 1 to 4, which were prepared by kneading and mixing the maleimide-based copolymers B-1 to B-4 which do not satisfy the scope of the present invention with an ABS resin, had poor flowability, heat resistance and surface gloss.

Industrial applicability

The maleimide copolymer of the present invention can be kneaded and mixed with an ABS resin, an ASA resin, an AES resin and a SAN resin to obtain a resin composition having an excellent balance among physical properties such as heat resistance, impact resistance, fluidity and surface gloss. The obtained resin composition is suitably used as a material for automobile interior parts, exterior parts, or the like.