Maleimide copolymer, method for producing the same, and resin composition using the same

Abstract

The present invention provides a maleimide copolymer, a method for producing the same, and a resin composition using the same. [Means for Solving the Problem] A maleimide copolymer containing 40 to 60% by mass of aromatic vinyl monomer units, 5 to 20% by mass of vinyl cyanide monomer units, and 35 to 50% by mass of maleimide monomer units, wherein a 4% by mass solution of the maleimide copolymer in tetrahydrofuran has a transmittance of 90% or more at a wavelength of 450 nm over a 10 mm optical path length, and the amount of residual maleimide monomer is less than 300 ppm. The maleimide copolymer preferably further contains 0 to 10% by mass of unsaturated dicarboxylic anhydride monomer units, and preferably has a glass transition temperature of 165°C or higher.

Description

Technical Field

[0001] The present invention relates to a maleimide copolymer, a method for producing the same, and a resin composition using the same.

Background Art

[0002] Acrylonitrile-butadiene-styrene copolymer resin (ABS resin) is widely used in automobiles, home appliances, OA equipment, housing building materials, daily necessities, etc. by taking advantage of its excellent mechanical strength, appearance, chemical resistance, moldability, etc. In applications where heat resistance is required, such as automotive interior materials, an ABS resin containing a maleimide copolymer as a heat resistance-imparting material is also used (see, for example, Patent Document 1 and Patent Document 2).

[0003] An ABS resin containing a maleimide copolymer has a drawback of being inferior in chemical resistance. To solve this drawback, a copolymer obtained by copolymerizing a vinyl cyanide monomer with a maleimide copolymer has been proposed (see, for example, Patent Document 3 and Patent Document 4). The maleimide copolymer copolymerized with a vinyl cyanide monomer has drawbacks such as being likely to have a yellowish hue, having a poor appearance in natural color, and being inferior in colorability.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention provides a maleimide copolymer capable of obtaining a resin composition excellent in the balance of hue, chemical resistance, heat resistance imparting property, impact resistance, and fluidity, and a method for producing the same. Further, a resin composition excellent in the physical property balance of hue, chemical resistance, heat resistance, impact resistance, and fluidity is provided, which is obtained by kneading and mixing the maleimide copolymer with one 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), or a styrene-acrylonitrile copolymer resin (SAN resin).

Means for Solving the Problems

[0006] That is, the present invention has the following gist. (1) A maleimide copolymer having 40 to 60% 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, wherein the transmittance of a 4% by mass tetrahydrofuran solution at a wavelength of 450 nm and an optical path length of 10 mm is 90% or more, and the residual amount of maleimide-based monomer is less than 300 ppm. (2) The maleimide copolymer according to (1), further having 0 to 10% by mass of an unsaturated dicarboxylic anhydride monomer unit in the maleimide copolymer. (3) The maleimide copolymer according to (1) or (2), having a glass transition temperature of 165°C or higher. (4) An initial polymerization step of mixing the total amount of the charged amount of the vinyl cyanide monomer, 10 to 90% by mass of the charged amount of the aromatic vinyl monomer, and 0 to 30% by mass of the charged amount of the unsaturated dicarboxylic anhydride monomer to initiate copolymerization, A middle polymerization step of continuing the copolymerization while adding 50 to 90% by mass of the remaining aromatic vinyl monomer used in the initial polymerization step and the total amount of the remaining unsaturated dicarboxylic anhydride monomer used in the initial polymerization step, either dividedly or continuously, A final polymerization step of adding the total amount of the remaining aromatic vinyl monomer used in the initial polymerization step and the middle polymerization step to obtain an aromatic vinyl-vinyl cyanide-unsaturated dicarboxylic anhydride copolymer A method for producing a maleimide copolymer according to any one of (1) to (3), comprising an imidization step of imidizing the obtained aromatic vinyl-vinyl cyanide-unsaturated dicarboxylic anhydride copolymer with ammonia or a primary amine to obtain a maleimide copolymer. (5) A resin composition comprising 5 to 40% by mass of a maleimide copolymer according to any one of (1) to (3) and 60 to 95% by mass of one or more resins selected from an ABS resin, an ASA resin, an AES resin, or a SAN resin. (6) An injection molded article using the resin composition according to (5). (7) The injection molded article according to (6), which is used as an interior member or an exterior member of an automobile. [[Effect of the Invention]]

[0007] According to the present invention, there are provided a maleimide copolymer and a method for producing the same, which can obtain a resin composition excellent in the balance of hue, chemical resistance, heat resistance imparting property, impact resistance, and fluidity. Further, there is provided a resin composition obtained by kneading and mixing a maleimide copolymer and one or more resins selected from an ABS resin, an ASA resin, an AES resin, or a SAN resin, which is excellent in the physical property balance of hue, chemical resistance, heat resistance, impact resistance, and fluidity. [[Embodiments for Carrying Out the Invention]]

[0008] [[Explanation of Terms]] In the specification of the present application, the description of "A to B" means A or more and B or less.

[0009] The maleimide copolymer of the present invention can be obtained by copolymerizing an aromatic vinyl monomer, a vinyl cyanide monomer, and a maleimide monomer.

[0010] The aromatic vinyl monomer used in the maleimide copolymer is for improving the hue of the resin composition (resin composition) obtained by kneading and mixing the maleimide copolymer, and examples include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, ethylstyrene, p-tert-butylstyrene, α-methylstyrene, α-methyl-p-methylstyrene, and the like. Among these, styrene, which has a high effect of improving the hue, is preferred. The styrene monomer may be used alone or in combination of two or more.

[0011] The amount of the aromatic vinyl monomer unit contained in the maleimide copolymer is 40 to 60% by mass, preferably 45 to 55% by mass. When the amount of the aromatic vinyl monomer unit is less than 40% by mass, the hue of the resin composition has a yellowish tint, and when it exceeds 60% by mass, the heat resistance of the resin composition decreases.

[0012] The vinyl cyanide monomer used in the maleimide copolymer is for improving the chemical resistance of the resin composition, and examples include acrylonitrile, methacrylonitrile, ethacrylonitrile, fumaronitrile, and the like. Among these, acrylonitrile, which has a high effect of improving the chemical resistance, is preferred. The acrylonitrile monomer may be used alone or in combination of two or more.

[0013] The amount of the vinyl cyanide monomer unit contained in the maleimide copolymer is 5 to 20% by mass, preferably 7 to 15% by mass. When 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 cannot be obtained, and when it exceeds 20% by mass, the hue of the resin composition has a yellowish tint.

[0014] The maleimide monomers used in the maleimide copolymer are those used to improve the heat resistance of the resin composition, and include N-alkyl maleimides such as N-methyl maleimide, N-butyl maleimide, and N-cyclohexyl maleimide, and N-phenyl maleimide, N-chlorophenyl maleimide, N-methylphenyl maleimide, N-methoxyphenyl maleimide, N-tribromophenyl maleimide, and the like. Among these, N-phenyl maleimide, which has a high effect of improving heat resistance, is preferred. The maleimide monomers may be used alone or in combination of two or more.

[0015] The amount of the maleimide monomer unit contained in the maleimide copolymer is 35 to 50% by mass, preferably 37 to 45% by mass. If the amount of the maleimide monomer unit is less than 35% by mass, the effect of improving the heat resistance of the resin composition cannot be obtained, and if it exceeds 50% by mass, the impact strength of the resin composition decreases. The content ratio of each monomer unit contained in the maleimide copolymer is a value measured under the following measurement conditions by the C-13 NMR method. Apparatus name: FT-NMR AVANCE300 (manufactured by BRUKER) Solvent: Deuterated chloroform Concentration: 14% by mass Temperature: 25 °C Number of integrations: 10000 times

[0016] When the maleimide copolymer is a 4% by mass tetrahydrofuran solution, the transmittance at a wavelength of 450 nm and an optical path length of 10 mm is 90% or more. If the transmittance is less than 90%, the hue of the resin composition obtained by kneading and mixing with one or more resins selected from ABS resin, ASA resin, AES resin, and SAN resin deteriorates. The transmittance is preferably 92% or more. The transmittance is a value measured using a spectrophotometer V-670ST (manufactured by JASCO Corporation) with a solution prepared by adjusting the maleimide copolymer to 4% by mass in tetrahydrofuran filled in a quartz cell for measuring an optical path length of 10 mm.

[0017] The content of the residual maleimide-based monomer in the maleimide-based copolymer is less than 300 ppm. Preferably, it is less than 200 ppm. When the content of the residual maleimide-based monomer is 300 ppm or more, the hue of the obtained maleimide-based copolymer will have a yellowish tint. The content of the residual maleimide-based monomer is the value measured under the following conditions. Apparatus name: Gas chromatograph GC-2010 (manufactured by Shimadzu Corporation) Column: Capillary column DB-5ms (manufactured by Agilent Technologies, Inc.) Temperature: Injection port 280 °C, detector 280 °C Perform temperature programming analysis with the column temperature at 80 °C (initial). (Temperature programming analysis conditions) 80 °C: Hold for 12 minutes 80 to 280 °C: Heat up at 20 °C / min for 10 minutes 280 °C: Hold for 10 minutes Detector: FID Procedure: Dissolve 0.5 g of the sample in 5 ml of a 1,2-dichloroethane solution (0.014 g / L) containing undecane (internal standard substance). Then, add 5 ml of n-hexane and shake for 10 to 15 minutes with a shaker to precipitate the polymer. Inject only the supernatant into the gas chromatograph in the state where the polymer is precipitated and settled. Calculate the quantitative value using the coefficient determined from the internal standard substance based on the peak area of the obtained maleimide-based monomer.

[0018] The maleimide copolymer may be copolymerized with copolymerizable monomers other than aromatic vinyl monomers, vinyl cyanide monomers, and maleimide monomers, as long as the effects of the present invention are not inhibited. Examples of copolymerizable monomers for the maleimide copolymer include unsaturated dicarboxylic anhydride monomers such as maleic anhydride, itaconic anhydride, citraconic anhydride, and aconitic anhydride; 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; acrylamide and methacrylamide. The copolymerizable monomers for the maleimide copolymer may be used alone or in combination of two or more.

[0019] As the copolymerizable monomer for the maleimide copolymer, an unsaturated dicarboxylic anhydride monomer is preferred. If the unsaturated dicarboxylic acid unit is 0.5% by mass or more, it is preferred because the unsaturated dicarboxylic acid unit reacts with other resins having amino group or alcohol group terminals to obtain the effect as a compatibilizer. If the unsaturated dicarboxylic anhydride monomer unit is 10% by mass or less, it is preferred because of excellent thermal stability, and if the unsaturated dicarboxylic anhydride monomer unit is 5% by mass or less, it is more preferred because of further excellent thermal stability.

[0020] In terms of efficiently improving the heat resistance of resins to be kneaded and mixed, such as ABS resin and ASA resin, the glass transition temperature of the maleimide copolymer is preferably 165°C to 200°C, more preferably 170°C to 200°C. Here, the glass transition temperature refers to the extrapolated glass transition start temperature (Tig) of the maleimide copolymer measured by the following apparatus and measurement conditions in accordance with JIS K-7121. Apparatus name: Differential Scanning Calorimeter Robot DSC6200 (manufactured by Seiko Instruments Inc.) Heating rate: 10°C / min

[0021] In order to increase the glass transition temperature of the maleimide copolymer, the content of the maleimide monomer unit may be increased or a monomer having a high glass transition temperature may be copolymerized.

[0022] The polymerization modes of the maleimide copolymer include solution polymerization and bulk polymerization. From the viewpoint of obtaining a maleimide copolymer having a uniform copolymer composition by polymerizing while adding the monomers to be copolymerized in portions or continuously, solution polymerization is preferred. The solvent for solution polymerization is preferably non-polymerizable from the viewpoint of being less likely to form by-products and having few adverse effects, and examples 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, dimethyl sulfoxide, N-methyl-2-pyrrolidone, etc. From the viewpoint of ease of solvent removal during devolatilization recovery of the maleimide copolymer, methyl ethyl ketone and methyl isobutyl ketone are preferred. The polymerization process can be applied to any of continuous polymerization, batch (batch) type, and semi-batch type.

[0023] The polymerization method of 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 °C. The polymerization initiator is not particularly limited, but known azo compounds such as azobisisobutyronitrile, azobiscyclohexanecarbonitrile, azobis(methylpropionitrile), azobis(methylbutyronitrile), and 2,4-diphenyl-4-methyl-1-pentene, benzoyl peroxide, t-butyl peroxybenzoate, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, t-butyl peroxyisopropyl monocarbonate, t-butyl peroxy-2-ethylhexanoate, di-t-butyl peroxide, dicumyl peroxide, ethyl-3,3-di-(t-butylperoxy)butyrate and other known organic peroxides can be used, and one or a combination of two or more of these can be used. From the viewpoints of the reaction rate of polymerization and the control of the polymerization rate, it is preferable to use an azo compound or an organic peroxide having a 10-hour half-life at 70 to 120 °C. The amount of the polymerization initiator used is not particularly limited, but it is preferably 0.1 to 1.5 parts by mass, more preferably 0.1 to 1.0 part by mass, based on 100 parts by mass of all the monomers used in the polymerization. If the amount of the polymerization initiator used is 0.1 part by mass or more, a sufficient polymerization rate can be obtained, which is preferable. If 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 control becomes easy and it becomes easy to obtain the target molecular weight.

[0024] For the production of the maleimide copolymer, a chain transfer agent can be used. 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, terpinolene, and the like. The amount of the chain transfer agent used is not particularly limited as long as the target molecular weight can be obtained, but it is preferably 0.01 to 0.8 parts by mass, more preferably 0.1 to 0.5 parts by mass, based on 100 parts by mass of all the monomers used in the polymerization. If the amount of the chain transfer agent used is 0.01 to 0.8 parts by mass, the target molecular weight can be easily obtained.

[0025] The maleimide copolymer of the present invention may be obtained by copolymerizing the above-described aromatic vinyl monomer, vinyl cyanide monomer, and unsaturated dicarboxylic anhydride, and imidizing the unsaturated dicarboxylic anhydride monomer unit in the copolymer with ammonia or a primary amine to convert it into a maleimide monomer unit (post-imidation method). Obtaining the maleimide copolymer by the post-imidation method is preferable because the amount of the residual maleimide-based monomer in the copolymer is reduced.

[0026] The primary amines include alkylamines such as methylamine, ethylamine, n-propylamine, iso-propylamine, n-butylamine, n-pentylamine, n-hexylamine, n-octylamine, cyclohexylamine, decylamine, and chlorine- or bromine-substituted alkylamines, and aromatic amines such as aniline, toluidine, and naphthylamine. Among these, aniline and cyclohexylamine are preferred. These primary amines may be used alone or in combination of two or more. The addition amount of the primary amine is not particularly limited, but is preferably 0.7 to 1.1 molar equivalents, more preferably 0.85 to 1.05 molar equivalents, based on the unsaturated dicarboxylic anhydride monomer unit. If it is 0.7 molar equivalent or more based on the unsaturated dicarboxylic anhydride monomer unit in the maleimide copolymer, the thermal stability of the resulting resin composition is good, which is preferable. Also, if it is 1.1 molar equivalent or less, the amount of the primary amine remaining in the maleimide copolymer is reduced, which is preferable.

[0027] When obtaining a maleimide copolymer by the post-imidation method, a catalyst can be used as needed for the purpose of improving the dehydration ring-closure reaction in the reaction of ammonia or a primary amine with an unsaturated dicarboxylic anhydride monomer unit, particularly in the reaction of converting the unsaturated dicarboxylic anhydride monomer unit to a maleimide monomer unit. The type of the catalyst is not particularly limited, but there are tertiary amines such as trimethylamine, triethylamine, tripropylamine, tributylamine, N,N-dimethylaniline, and N,N-diethylaniline. The addition amount of the tertiary amine is not particularly limited, but is preferably 0.01 molar equivalent or more based on the unsaturated dicarboxylic anhydride monomer unit. The temperature of the imidation reaction in the present invention is preferably 100 to 250°C, more preferably 120 to 200°C. If the temperature of the imidation reaction is 100°C or higher, the reaction rate is sufficiently fast, which is preferable from the viewpoint of productivity. If the temperature of the imidation reaction is 250°C or lower, the deterioration of physical properties due to thermal degradation of the maleimide copolymer can be suppressed, which is preferable.

[0028] When obtaining a maleimide copolymer by the post-imidation method, it is possible to polymerize by charging the entire amounts of the aromatic vinyl monomer, vinyl cyanide monomer, and unsaturated dicarboxylic anhydride monomer at the initial stage of polymerization. However, since the aromatic vinyl monomer and the unsaturated dicarboxylic anhydride monomer have strong alternating copolymerizability, the aromatic vinyl monomer and the unsaturated dicarboxylic anhydride monomer are consumed in the early stage of polymerization, and a copolymer rich in vinyl cyanide monomer units is likely to be formed in the later stage of polymerization. As a result, the hue of the resulting maleimide copolymer may deteriorate, or the composition distribution may become large, lacking compatibility when kneaded and mixed with an ABS resin or the like, and the resulting resin composition may have unfavorable physical properties. Therefore, in order to obtain a maleimide copolymer with good hue and a small (uniform) composition distribution, it is preferable to use a production method having the following steps. Initial polymerization step: Mix all of the charged amount of the vinyl cyanide monomer, 10 to 90% by mass of the charged amount of the aromatic vinyl monomer, and 0 to 30% by mass of the charged amount of the unsaturated dicarboxylic anhydride monomer, charge them at the initial stage of polymerization, and initiate copolymerization. Middle polymerization step: Continue copolymerization while adding 50 to 90% by mass of the remaining aromatic vinyl monomer used in the initial polymerization step and all of the remaining unsaturated dicarboxylic anhydride monomer used in the initial polymerization step, either separately or continuously. Final polymerization step: Add all of the remaining aromatic vinyl monomer used in the initial polymerization step and the middle polymerization step to obtain an aromatic vinyl-vinyl cyanide-unsaturated dicarboxylic anhydride copolymer. Imidation step: Imidate the obtained aromatic vinyl-vinyl cyanide-unsaturated dicarboxylic anhydride copolymer with ammonia or a primary amine to obtain a maleimide copolymer.

[0029] After the solution polymerization of the maleimide copolymer is completed, or after the post-imidation is completed, a method (devolatilization method) for removing volatile components such as the solvent used in the solution polymerization and unreacted monomers can adopt known techniques. For example, a vacuum devolatilization tank equipped with a heater or a devolatilization extruder with a vent can be used. The devolatilized maleimide copolymer in a molten state is transferred to a granulation process, extruded in a strand shape from a porous die, and can be processed into a pellet shape by a cold cut method, an air hot cut method, or a water hot cut method.

[0030] The maleimide copolymer thus obtained can be used as a heat resistance-imparting agent for the resulting resin composition by kneading and mixing it with various resins. The various resins are not particularly limited, but include ABS resin, ASA resin, AES resin, and SAN resin. Since the maleimide copolymer and these resins have excellent compatibility, a high heat resistance-imparting effect can be obtained. The blending ratio of the maleimide copolymer and these resins is preferably 5 to 40% by mass of the maleimide copolymer and 60 to 95% by mass of one or more resins selected from the group consisting of ABS resin, ASA resin, AES resin, and SAN resin. More preferably, it is 10 to 30% by mass of the maleimide copolymer and 70 to 90% by mass of one or more resins selected from the group consisting of ABS resin, ASA resin, AES resin, and SAN resin. If the blending ratio of the maleimide copolymer is within this range, the effect of improving the heat resistance of the resin composition can be obtained, and the chemical resistance and hue of the resin composition do not deteriorate. The method for kneading and mixing the maleimide copolymer and various resins is not particularly limited, but known melt-kneading techniques can be used. As melt-kneading devices that can be preferably used, there are screw extruders such as single-screw extruders, fully intermeshing co-rotating twin-screw extruders, fully intermeshing counter-rotating twin-screw extruders, non- or incompletely intermeshing twin-screw extruders, Banbury mixers, conical kneaders, and mixing rolls. When kneading and mixing the maleimide copolymer and these resins, stabilizers, ultraviolet absorbers, flame retardants, plasticizers, lubricants, glass fibers, inorganic fillers, colorants, antistatic agents, etc. can be added without any problem.

[0031] Regarding the method for obtaining a molded body from a resin composition, known molding processing techniques can be used, such as injection molding, extrusion molding, sheet molding, and press molding. The resin composition of the present invention is particularly excellent in heat resistance and can be particularly preferably used as a material for injection molding that involves high temperature and high pressure during the molding process.

[0032] The molded body obtained by molding the resin composition can be suitably used for interior members and exterior members of automobiles.

Examples

[0033] Hereinafter, the detailed content will be described using examples, but the present invention is not limited to the following examples.

[0034] <Production Example of Maleimide Copolymer (A-1)> Into an autoclave with a volume of about 120 liters equipped with a stirrer, 22 parts by mass of styrene, 13 parts by mass of acrylonitrile, 4 parts by mass of maleic anhydride, 0.1 part by mass of 2,4-diphenyl-4-methyl-1-pentene, and 12 parts by mass of methyl ethyl ketone were charged. After replacing the gas phase part with nitrogen gas, the temperature was raised to 92°C over 40 minutes while stirring. After the temperature rise, while maintaining 92°C, a solution prepared by dissolving 25 parts by mass of maleic anhydride and 0.22 part by mass of t-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. Further, after the addition of maleic anhydride was completed, 8 parts by mass of styrene were continuously added over 2 hours. After the addition of styrene, the temperature was raised to 120°C and reacted for 1 hour to complete the polymerization. Thereafter, 26 parts by mass of aniline and 0.5 part by mass of triethylamine were added to the polymerization solution and reacted at 140°C for 7 hours. The imidization reaction solution after the reaction was charged into a vent-type screw extruder to remove the volatile components and obtain pellet-shaped maleimide copolymer A-1. The analysis results of the obtained maleimide copolymer A-1 are shown in Table 1.

[0035] <Production Example of Maleimide Copolymer (A-2)> Into an autoclave with a volume of about 120 liters equipped with a stirrer, 20 parts by mass of styrene, 8 parts by mass of acrylonitrile, 4 parts by mass of N-phenylmaleimide, 0.1 part by mass of 2,4-diphenyl-4-methyl-1-pentene, and 16 parts by mass of methyl ethyl ketone were charged. After replacing the gas phase with nitrogen gas, the temperature was raised to 92 °C over 40 minutes while stirring. While maintaining 92 °C after the temperature rise, a solution prepared by dissolving 38 parts by mass of N-phenylmaleimide and 0.2 part by mass of t-butyl peroxy-2-ethylhexanoate in 152 parts by mass of methyl ethyl ketone and 23 parts by mass of styrene were continuously added over 7 hours. Further, after the addition of N-phenylmaleimide was completed, 7 parts by mass of styrene were continuously added over 2 hours. After the addition of styrene, the temperature was raised to 120 °C and reacted for 1 hour to complete the polymerization. The polymerization solution after the reaction was put into a vent type screw extruder to remove volatile components, and a pelletized maleimide copolymer A-2 was obtained. The analysis results of the obtained maleimide copolymer A-2 are shown in Table 1.

[0036] <Production Example of Maleimide Copolymer (A-3)> Into an autoclave with a volume of about 120 liters equipped with a stirrer, 17 parts by mass of styrene, 22 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 part by mass of 2,4-diphenyl-4-methyl-1-pentene, and 20 parts by mass of methyl ethyl ketone were charged. After replacing the gas phase with nitrogen gas, the temperature was raised to 92 °C over 40 minutes while stirring. While maintaining 92 °C after the temperature rise, a solution prepared by dissolving 20 parts by mass of maleic anhydride and 0.25 part by mass of t-butyl peroxy-2-ethylhexanoate in 80 parts by mass of methyl ethyl ketone and 28 parts by mass of styrene were continuously added over 7 hours. Further, after the addition of maleic anhydride was completed, 8 parts by mass of styrene were continuously added over 2 hours. After the addition of styrene, the temperature was raised to 120 °C and reacted for 1 hour to complete the polymerization. Then, 22 parts by mass of aniline and 0.4 part by mass of triethylamine were added to the polymerization solution and reacted at 140 °C for 7 hours. The imidization reaction solution after the reaction was put into a vent type screw extruder to remove volatile components, and a pelletized maleimide copolymer A-3 was obtained. The analysis results of the obtained maleimide copolymer A-3 are shown in Table 1.

[0037] <Production Example of Maleimide Copolymer (A-4)> Into an autoclave with a volume of about 120 liters equipped with a stirrer, 13 parts by mass of styrene, 11 parts by mass of acrylonitrile, 6 parts by mass of maleic anhydride, 0.1 part by mass of 2,4-diphenyl-4-methyl-1-pentene, and 18 parts by mass of methyl ethyl ketone were charged. After replacing the gas phase part with nitrogen gas, the temperature was raised to 92°C over 40 minutes while stirring. While maintaining 92°C after the temperature rise, a solution prepared by dissolving 30 parts by mass of maleic anhydride and 0.2 part by mass of t-butyl peroxy-2-ethylhexanoate in 90 parts by mass of methyl ethyl ketone and 31 parts by mass of styrene were continuously added over 7 hours. Further, after the addition of maleic anhydride was completed, 9 parts by mass of styrene was continuously added over 2 hours. After the addition of styrene, the temperature was raised to 120°C and reacted for 1 hour to complete the polymerization. Then, 32 parts by mass of aniline and 0.6 part by mass of triethylamine were added to the polymerization solution and reacted at 140°C for 7 hours. The imidized reaction solution after the reaction was put into a vent type screw extruder to remove volatile components, and a pellet-shaped maleimide copolymer A-4 was obtained. The analysis results of the obtained maleimide copolymer A-4 are shown in Table 1.

[0038] <Production Example of Maleimide Copolymer (A-5)> Into an autoclave with a volume of about 120 liters equipped with a stirrer, 45 parts by mass of styrene, 8 parts by mass of acrylonitrile, 0.1 part by mass of 2,4-diphenyl-4-methyl-1-pentene, and 16 parts by mass of methyl ethyl ketone were charged. After replacing the gas phase with nitrogen gas, the temperature was raised to 92°C over 40 minutes while stirring. While maintaining the temperature at 92°C after the temperature rise, a solution prepared by dissolving 24 parts by mass of maleic anhydride and 0.3 part by mass of t-butyl peroxy-2-ethylhexanoate in 96 parts by mass of methyl ethyl ketone and 18 parts by mass of styrene were continuously added over 7 hours. Further, after the addition of maleic anhydride was completed, 5 parts by mass of styrene were continuously added over 2 hours. After the addition of styrene, the temperature was raised to 120°C and reacted for 1 hour to complete the polymerization. Then, 21 parts by mass of aniline and 0.4 part by mass of triethylamine were added to the polymerization solution and reacted at 140°C for 7 hours. The imidized reaction solution after the reaction was put into a vent type screw extruder to remove volatile components and obtain pellet-shaped maleimide copolymer A-5. The analysis results of the obtained maleimide copolymer A-5 are shown in Table 1.

[0039] <Production Example of Maleimide Copolymer (A-6)> Into an autoclave with a volume of about 120 liters equipped with a stirrer, 22 parts by mass of styrene, 13 parts by mass of acrylonitrile, 4 parts by mass of maleic anhydride, 0.1 part by mass of 2,4-diphenyl-4-methyl-1-pentene, and 12 parts by mass of methyl ethyl ketone were charged. After replacing the gas phase with nitrogen gas, the temperature was raised to 92°C over 40 minutes while stirring. While maintaining 92°C after the temperature rise, a solution prepared by dissolving 25 parts by mass of maleic anhydride and 0.22 part by mass of t-butyl peroxy-2-ethylhexanoate in 75 parts by mass of methyl ethyl ketone and 32 parts by mass of styrene were continuously added over 8 hours. Further, after the addition of maleic anhydride was completed, 4 parts by mass of styrene was continuously added over 1 hour. After the addition of styrene, the temperature was raised to 120°C and reacted for 1 hour to complete the polymerization. Then, 26 parts by mass of aniline and 0.5 part by mass of triethylamine were added to the polymerization solution and reacted at 140°C for 7 hours. The imidized reaction solution after the reaction was put into a vent-type screw extruder to remove volatile components and obtain pellet-shaped maleimide copolymer A-6. The analysis results of the obtained maleimide copolymer A-6 are shown in Table 1.

[0040] <Production Example of Maleimide Copolymer (A-7)> Into an autoclave with a volume of about 120 liters equipped with a stirrer, 59.7 parts by mass of styrene, 3.8 parts by mass of acrylonitrile, 0.05 part by mass of 2,4-diphenyl-4-methyl-1-pentene, and 18 parts by mass of methyl isobutyl ketone were charged. After replacing the gas phase with nitrogen gas, the temperature was raised to 90°C over 40 minutes while stirring. While maintaining 90°C after the temperature rise, a solution prepared by dissolving 36.5 parts by mass of maleic anhydride and 0.1 part by mass of t-butyl peroxy-2-ethylhexanoate in 120 parts by mass of methyl isobutyl ketone was continuously added over 4 hours. After the addition of maleic anhydride was completed, the temperature was raised to 110°C and reacted for 2 hours to complete the polymerization. Then, 32.7 parts by mass of aniline and 0.5 part by mass of triethylamine were added to the polymerization solution and reacted at 155°C for 4 hours. The imidized reaction solution after the reaction was put into a vent-type screw extruder to remove volatile components and obtain pellet-shaped maleimide copolymer A-7. The analysis results of the obtained maleimide copolymer A-7 are shown in Table 2.

[0041] <Production Example of Maleimide Copolymer (A-8)> Into an autoclave with a volume of about 120 liters equipped with a stirrer, 25.1 parts by mass of styrene, 14.9 parts by mass of acrylonitrile, 0.05 parts by mass of 2,4-diphenyl-4-methyl-1-pentene, and 18 parts by mass of methyl isobutyl ketone were charged. After replacing the gas phase part with nitrogen gas, the temperature was raised to 90°C over 40 minutes while stirring. While maintaining 90°C after the temperature rise, a solution prepared by dissolving 25 parts by mass of styrene, 35 parts by mass of maleic anhydride, and 0.1 parts by mass of t-butyl peroxy-2-ethylhexanoate in 120 parts by mass of methyl isobutyl ketone was continuously added over 4 hours. After the addition of maleic anhydride was completed, the temperature was raised to 110°C and reacted for 2 hours to complete the polymerization. Then, 31.9 parts by mass of aniline and 0.5 parts by mass of triethylamine were added to the polymerization solution and reacted at 155°C for 4 hours. The imidization reaction solution after the reaction was put into a vent type screw extruder to remove the volatile components and obtain pelletized maleimide copolymer A-8. The analysis results of the obtained maleimide copolymer A-8 are shown in Table 2.

[0042] <Production Example of Maleimide Copolymer (A-9)> Into an autoclave with a volume of about 120 liters equipped with a stirrer, 65 parts by mass of styrene, 8 parts by mass of acrylonitrile, 2 parts by mass of maleic anhydride, 0.1 part by mass of 2,4-diphenyl-4-methyl-1-pentene, and 10 parts by mass of methyl ethyl ketone were charged. After replacing the gas phase part with nitrogen gas, the temperature was raised to 92°C over 40 minutes while stirring. While maintaining 92°C after the temperature rise, a solution prepared by dissolving 16 parts by mass of maleic anhydride and 0.3 part by mass of t-butyl peroxy-2-ethylhexanoate in 80 parts by mass of methyl ethyl ketone and 7 parts by mass of styrene were continuously added over 7 hours. Further, after the addition of maleic anhydride was completed, 2 parts by mass of styrene were continuously added over 2 hours. After the addition of styrene, the temperature was raised to 120°C and reacted for 1 hour to complete the polymerization. Then, 16 parts by mass of aniline and 0.3 part by mass of triethylamine were added to the polymerization solution and reacted at 140°C for 7 hours. The imidized reaction solution after the reaction was charged into a vent type screw extruder to remove volatile components, and pelletized maleimide copolymer A-9 was obtained. The analysis results of the obtained maleimide copolymer A-9 are shown in Table 2.

[0043] <Production Example of Maleimide Copolymer (A-10)> Into an autoclave with a volume of about 120 liters equipped with a stirrer, 14 parts by mass of styrene, 28 parts by mass of acrylonitrile, 3 parts by mass of maleic anhydride, 0.1 part by mass of 2,4-diphenyl-4-methyl-1-pentene, and 12 parts by mass of methyl ethyl ketone were charged. After replacing the gas phase with nitrogen gas, the temperature was raised to 92°C over 40 minutes while stirring. While maintaining 92°C after the temperature rise, a solution prepared by dissolving 23 parts by mass of maleic anhydride and 0.4 part by mass of t-butyl peroxy-2-ethylhexanoate in 92 parts by mass of methyl ethyl ketone and 25 parts by mass of styrene were continuously added over 7 hours. Further, after the addition of maleic anhydride was completed, 7 parts by mass of styrene was continuously added over 2 hours. After the addition of styrene, the temperature was raised to 120°C and the reaction was carried out for 1 hour to complete the polymerization. Then, 23 parts by mass of aniline and 0.4 part by mass of triethylamine were added to the polymerization solution and reacted at 140°C for 7 hours. The imidized reaction solution after the reaction was put into a vent type screw extruder to remove volatile components, and pellet-shaped maleimide copolymer A-10 was obtained. The analysis results of the obtained maleimide copolymer A-10 are shown in Table 2.

[0044] <Production Example of Maleimide Copolymer (A-11)> Into an autoclave with a volume of about 120 liters equipped with a stirrer, 2 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 part by mass of 2,4-diphenyl-4-methyl-1-pentene, and 15 parts by mass of methyl ethyl ketone were charged. After replacing the gas phase part with nitrogen gas, the temperature was raised to 92°C over 40 minutes while stirring. While maintaining 92°C after the temperature rise, a solution prepared by dissolving 38 parts by mass of maleic anhydride and 0.4 part by mass of t-butyl peroxy-2-ethylhexanoate in 114 parts by mass of methyl ethyl ketone and 35 parts by mass of styrene were continuously added over 7 hours. Further, after the addition of maleic anhydride was completed, 10 parts by mass of styrene was continuously added over 2 hours. After the addition of styrene, the temperature was raised to 120°C and reacted for 1 hour to complete the polymerization. Thereafter, 38 parts by mass of aniline and 0.7 part by mass of triethylamine were added to the polymerization solution and reacted at 140°C for 7 hours. The imidized reaction solution after the reaction was put into a vent type screw extruder to remove volatile components, and a pelletized maleimide copolymer A-11 was obtained. The analysis results of the obtained maleimide copolymer A-11 are shown in Table 2.

[0045] <Production Example of Maleimide Copolymer (A-12)> Into an autoclave with a volume of about 120 liters equipped with a stirrer, 65 parts by mass of styrene, 7 parts by mass of maleic anhydride, 0.2 part by mass of 2,4-diphenyl-4-methyl-1-pentene, and 25 parts by mass of methyl ethyl ketone were charged. After replacing the inside of the system with nitrogen gas, the temperature was raised to 92°C, and a solution prepared by dissolving 28 parts by mass of maleic anhydride and 0.18 part by mass of t-butyl peroxy-2-ethylhexanoate in 100 parts by mass of methyl ethyl ketone was continuously added over 7 hours. After the addition, 0.03 part by mass of t-butyl peroxy-2-ethylhexanoate was further added, the temperature was raised to 120°C, and reacted for 1 hour to complete the polymerization. Thereafter, 32 parts by mass of aniline and 0.6 part by mass of triethylamine were added to the polymerization solution and reacted at 140°C for 7 hours. The imidized reaction solution after the reaction was put into a vent type screw extruder to remove volatile components, and a pelletized maleimide copolymer A-12 was obtained. The analysis results of the obtained maleimide copolymer A-12 are shown in Table 2.

[0046] <Production Example of Maleimide Copolymer (A-13)> Into an autoclave with a volume of about 120 liters equipped with a stirrer, 40 parts by mass of styrene, 16 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.2 parts by mass of 2,4-diphenyl-4-methyl-1-pentene, and 20 parts by mass of methyl ethyl ketone were charged. After replacing the inside of the system with nitrogen gas, the temperature was raised to 92 °C. A solution prepared by dissolving 16 parts by mass of maleic anhydride and 0.3 parts by mass of t-butyl peroxy-2-ethylhexanoate in 80 parts by mass of methyl ethyl ketone and 18 parts by mass of styrene were continuously added over 7 hours. Further, after the addition of maleic anhydride was completed, 5 parts by mass of styrene were continuously added over 2 hours. After the addition of styrene, the temperature was raised to 120 °C and reacted for 1 hour to complete the polymerization. Then, 19 parts by mass of aniline and 0.4 parts by mass of triethylamine were added to the polymerization solution and reacted at 140 °C for 7 hours. The imidized reaction solution after the reaction was put into a vent-type screw extruder to remove volatile components, and a pellet-shaped maleimide copolymer A-13 was obtained. The analysis results of the obtained maleimide copolymer A-13 are shown in Table 2.

[0047]

Table 1

[0048]

Table 2

[0049] (Composition Analysis) The maleimide copolymer was measured under the following measurement conditions using the C-13 NMR method. Apparatus name: FT-NMR AVANCE300 (manufactured by BRUKER) Solvent: Deuterated chloroform Concentration: 14% by mass Temperature: 27 °C Number of integrations: 8000 times

[0050] (Transmittance at 450 nm) The maleimide copolymer was dissolved in tetrahydrofuran to prepare a 4% by mass tetrahydrofuran solution, which was then filled into a quartz cell with a 10 mm optical path length for measurement. After that, the measurement was carried out using a spectrophotometer V-670ST (manufactured by JASCO Corporation).

[0051] (Glass transition temperature) In accordance with JIS K-7121, the extrapolated glass transition start temperature (Tig) of the maleimide copolymer was measured under the following apparatus and measurement conditions. Apparatus name: Robot DSC6200 (manufactured by Seiko Instruments Inc.) Heating rate: 10 °C / min

[0052] (Residual maleimide monomer amount) Procedure: Dissolve 0.5 g of the sample in 5 ml of a 1,2-dichloroethane solution (0.014 g / L) containing undecane (internal standard substance). Then, add 5 ml of n-hexane and shake for 10 - 15 minutes using a shaker to precipitate. Inject only the supernatant into the gas chromatograph with the polymer in a precipitated state. The quantitative value was calculated using the coefficient determined from the internal standard substance based on the peak area of the obtained maleimide monomer. Apparatus name: Gas chromatograph GC-2010 (manufactured by Shimadzu Corporation) Column: Capillary column DB-5ms (manufactured by Agilent Technologies, Inc.) Temperature: Injection port 280 °C, detector 280 °C Perform temperature rise analysis with the column temperature at 80 °C (initial). (Temperature rise analysis conditions) 80 °C: Hold for 12 minutes 80 - 280 °C: Heat at 20 °C / min for 10 minutes 280 °C: Hold for 10 minutes Detector: FID

[0053] <Resin composition> Examples 7 - 14, Comparative Examples 8 - 16 (kneading and mixing of maleimide copolymer and ABS resin) Maleimide copolymer A-1 to A-13 and a commercially available ABS resin GR-3000 (manufactured by Denka Co., Ltd.) were blended at the blending ratios (mass %) shown in Tables 3 and 4, and then pelletized by extrusion under the conditions shown in Tables 3 and 4 using a twin-screw extruder TEM-35B (manufactured by Toshiba Machine Co., Ltd.). Test pieces were prepared using these pellets by an injection molding machine, and the physical property values were measured. The results are shown in Tables 3 and 4.

[0054]

Table 3

[0055]

Table 4

[0056] (Charpy impact strength) In accordance with JIS K-7111, using a notched test piece, the impact direction was edgewise, and the measurement was carried out at a relative humidity of 50% and an ambient temperature of 23°C. A digital impact tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.) was used as the measuring instrument. When the Charpy impact strength is 15 kJ / m 2 The above cases were judged to be good.

[0057] (Melt mass flow rate) Measured in accordance with JIS K7210 at 220°C and a load of 98 N. When the melt mass flow rate is 3 g / 10 min or more, it was judged to be good.

[0058] (Vicat softening point) Measured in accordance with JIS K7206 by the 50 method (load 50 N, heating rate 50°C / hour) using a test piece of 10 mm × 10 mm and a thickness of 4 mm. An HDT&VSPT test device (manufactured by Toyo Seiki Seisakusho Co., Ltd.) was used as the measuring instrument. When the Vicat softening point is 110°C or higher, it was judged to be good.

[0059] (Chemical resistance) Using the 1 / 4 ellipse method with a test piece shape of 316×20×2 mm, a major radius of 250 mm, and a minor radius of 150 mm, cracks after 48 hours at 23°C were observed. To eliminate the influence of molding strain, the test pieces were manufactured by pressing pellets at 260°C and then cutting them out. Toluene was used as the chemical. The critical strain was calculated using the following formula. ε = b / 2a 2 {1 - (a 2 - b 2 )X 2 / a 4} 1.5 × t × 100 Critical strain: ε, major radius: a, minor radius: b, test thickness: t, crack occurrence point: X The chemical resistance was evaluated based on the following criteria from the critical strain. ◎: 0.8 or more, ○: 0.6 - 0.7, △: 0.3 - 0.5, ×: 0.2 or less

[0060] (YI (hue)) Using an injection molding machine IS - 50EP (manufactured by Toshiba Machine Co., Ltd.), a plate (9 cm × 5 cm) was molded at a molding temperature of 240°C, and the yellowness index YI was measured using a color difference meter COLOR - 7e 2 (manufactured by Kurashiki Boseki Co., Ltd.). When the yellowness index YI was 40 or less, it was judged to be good.

[0061] The maleimide copolymers of Examples 1 to 6 of the present invention have a sufficiently high transmittance at 450 nm and a sufficiently high glass transition temperature. Therefore, the resin compositions of Examples 7 to 14 obtained by kneading and mixing these maleimide copolymers with an ABS resin have excellent impact resistance, fluidity, heat resistance, chemical resistance, and hue. Further, since the matrix resin of the ABS resin is an AS resin, the maleimide copolymer of the present invention is expected to have the same effect also in the AS resin, the AES resin, and the ASA resin having the AS resin as the matrix resin. On the other hand, the maleimide copolymers of Comparative Examples 1 to 7 that do not meet the scope of the present invention are outside the claims of the present invention, and the resin compositions of Comparative Examples 8 to 16 obtained by kneading and mixing these maleimide copolymers with an ABS resin were inferior in any of impact resistance, fluidity, heat resistance, chemical resistance, and hue.

Industrial Applicability

[0062] The maleimide copolymer of the present invention can obtain a resin composition excellent in the physical property balance of hue, chemical resistance, heat resistance, impact resistance, and fluidity by kneading and mixing with an ABS resin, an ASA resin, an AES resin, and a SAN resin. The obtained resin composition can be suitably used as a material such as an interior member or an exterior member of an automobile.

Claims

1. A maleimide-based copolymer having 40 to 56.3% 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, wherein the transmittance at a wavelength of 450 nm and an optical path length of 10 mm of a 4% by mass tetrahydrofuran solution is 90% or more, the residual amount of the maleimide-based monomer is less than 300 ppm, and in the maleimide-based copolymer, further, 5 to 40% by mass of a maleimide-based copolymer having 0.5 to 10% by mass of an unsaturated dicarboxylic anhydride monomer unit, and 60 to 95% by mass of an acrylonitrile-butadiene-styrene copolymer resin (ABS resin). A resin composition in which the glass transition temperature of the maleimide-based copolymer is 165°C or higher.

2. An injection molded article using the resin composition according to Claim 1.

3. The injection molded article according to Claim 2, which is used as an interior member or an exterior member of an automobile.

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