MALEIMIDE COPOLYMER, MANUFACTURING METHOD THEREFOR, AND RESIN COMPOSITION USING SAME

Abstract

A maleimide based copolymer, manufacturing method thereof, and a resin composition using the maleimide based copolymer is provided. A maleimide based copolymer includes 40 to 60 mass % of aromatic vinyl monomer unit, 5 to 20 mass % of vinyl cyanide monomer unit, 25 to 50 mass % of maleimide monomer unit, 0.1 to 10 mass % of dicarboxylic anhydride monomer unit; wherein the maleimide based copolymer has a glass transition temperature of 165 to 200° C.; and an average number of the dicarboxylic anhydride monomer unit contained in one copolymer molecule is 1 to 30 units. Further, a resin composition is obtained by kneading and mixing the maleimide based copolymer with one or two or more resin selected from the group including ABS resin, ASA resin, AES resin, and SAN resin. The resin composition is superior in the balance of surface glossiness, heat resistance, impact resistance, and flowability.

Claims

1-5. (canceled)

6. A maleimide based 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 based copolymer has a glass transition temperature of 165 to 200° C.; and an average number of the dicarboxylic anhydride monomer unit contained in one copolymer molecule is 1 to 30.

7. A manufacturing method of the maleimide based copolymer of claim 6, comprising: an initial polymerization step to start copolymerization by blending entire amount of vinyl cyanide monomer to be charged, 10 to 90 mass % of the aromatic vinyl monomer to be charged, and 0 to 30 mass % of the unsaturated dicarboxylic anhydride monomer to be charged; a middle polymerization step to continue copolymerization while adding 50 to 90 mass % of residual amount of the aromatic vinyl monomer and entirety of residual amount of the unsaturated dicarboxylic anhydride monomer, each added by portions or continuously; a final polymerization step to add entirety of residual amount of aromatic vinyl monomer to obtain a copolymer including the aromatic vinyl monomer unit, the vinyl cyanide monomer unit, and the dicarboxylic anhydride monomer unit; and an imidizing step to imidize the dicarboxylic anhydride monomer unit of the copolymer obtained into the maleimide monomer unit by utilizing ammonia or a primary amine.

8. A resin composition comprising 4 to 50 mass % of the maleimide based copolymer of claims 6 and 60 to 95 mass % of one or two or more of a resin selected from the group consisting of acrylonitrile-butadiene-styrene copolymer resin, acrylonitrile-styrene-acryl based rubber copolymer resin, acrylonitrile-ethylene propylene based rubber-styrene copolymer resin, and styrene-acrylonitrile copolymer resin.

9. An injection molded body comprising the resin composition of claim 8.

10. The injection molded body of claim 9, which is an interior component or exterior component of an automobile.

Description

EXAMPLE

[0069] Hereinafter, detailed explanation is provided with reference to Examples. However, the present invention is not limited to the following Examples.

<Production Example of Maleimide Based Copolymer (A-1)>

[0070] To an autoclave having a capacity of about 120 liters equipped with an agitator, 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 parts by mass of t-butylperoxy-2-ethylhexanoate, 0.025 parts by mass of α-methyl styrene dimer, and 12 parts by mass of methyl isobutyl ketone were charged. After replacing the gaseous phase of the system with nitrogen gas, the temperature was raised to 92° C. over 40 minutes with agitation. After raising the temperature, the temperature was kept at 92° C., and a solution prepared by dissolving 23 parts by mass of maleic anhydride and 0.22 parts by mass of t-butylperoxy-2-ethylhexanoate in 50 parts by mass of methyl isobutyl ketone and 28 parts by mass of styrene were added continuously over 4.5 hours. Further, after completion of the addition of maleic anhydride, 14 parts by mass of styrene was added continuously over 0.5 hour. After adding styrene, the temperature of the reaction mixture was raised to 120° C., and the reaction was carried out for 0.5 hour to complete polymerization. Thereafter, 26.6 parts by mass of aniline and 0.5 parts by mass of triethylamine were added to the polymerization solution, and reaction was carried out at 140° C. for 6 hours. The imidizing reaction solution after completion of reaction was fed to a vent type screw extruder, and the volatile component was removed to obtain pellet maleimide based copolymer A-1. Results of analysis for the maleimide based copolymer A-1 are shown in Table 1.

<Production Example of Maleimide Based Copolymer (A-2)>

[0071] To an autoclave having a capacity of about 120 liters equipped with an agitator, 20 parts by mass of styrene, 11 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 parts by mass of t-butylperoxy-2-ethylhexanoate, 0.025 parts by mass of α-methyl styrene dimer, and 12 parts by mass of methyl isobutyl ketone were charged. After replacing the gaseous phase of the system with nitrogen gas, the temperature was raised to 92° C. over 40 minutes with agitation. After raising the temperature, the temperature was kept at 92° C., and a solution prepared by dissolving 27 parts by mass of maleic anhydride and 0.22 parts by mass of t-butylperoxy-2-ethylhexanoate in 50 parts by mass of methyl isobutyl ketone and 28 parts by mass of styrene were added continuously over 4.5 hours. Further, after completion of the addition of maleic anhydride, 9 parts by mass of styrene was added continuously over 0.5 hour. After adding styrene, the temperature of the reaction mixture was raised to 120° C., and the reaction was carried out for 0.5 hour to complete polymerization. Thereafter, 30.0 parts by mass of aniline and 0.5 parts by mass of triethylamine were added to the polymerization solution, and reaction was carried out at 140° C. for 6 hours. The imidizing reaction solution after completion of reaction was fed to a vent type screw extruder, and the volatile component was removed to obtain pellet maleimide based copolymer A-2. Results of analysis for the maleimide based copolymer A-2 are shown in Table 1.

<Production Example of Maleimide Based Copolymer (A-3)>

[0072] To an autoclave having a capacity of about 120 liters equipped with an agitator, 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 parts by mass of t-butylperoxy-2-ethylhexanoate, 0.025 parts by mass of α-methyl styrene dimer, and 12 parts by mass of methyl isobutyl ketone were charged. After replacing the gaseous phase of the system with nitrogen gas, the temperature was raised to 92° C. over 40 minutes with agitation. After raising the temperature, the temperature was kept at 92° C., and a solution prepared by dissolving 23 parts by mass of maleic anhydride and 0.22 parts by mass of t-butylperoxy-2-ethylhexanoate in 50 parts by mass of methyl isobutyl ketone and 28 parts by mass of styrene were added continuously over 4.5 hours. Further, after completion of the addition of maleic anhydride, 14 parts by mass of styrene was added continuously over 0.5 hour. After adding styrene, the temperature of the reaction mixture was raised to 120° C., and the reaction was carried out for 0.5 hour to complete polymerization. Thereafter, 26.6 parts by mass of aniline and 0.5 parts by mass of triethylamine were added to the polymerization solution, and reaction was carried out at 140° C. for 8 hours. The imidizing reaction solution after completion of reaction was fed to a vent type screw extruder, and the volatile component was removed to obtain pellet maleimide based copolymer A-3. Results of analysis for the maleimide based copolymer A-3 are shown in Table 1.

<Production Example of Maleimide Based Copolymer (A-4)>

[0073] To an autoclave having a capacity of about 120 liters equipped with an agitator, 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 parts by mass of t-butylperoxy-2-ethylhexanoate, 0.4 parts by mass of α-methyl styrene dimer, and 12 parts by mass of methyl isobutyl ketone were charged. After replacing the gaseous phase of the system with nitrogen gas, the temperature was raised to 92° C. over 40 minutes with agitation. After raising the temperature, the temperature was kept at 92° C., and a solution prepared by dissolving 23 parts by mass of maleic anhydride and 0.22 parts by mass of t-butylperoxy-2-ethylhexanoate in 50 parts by mass of methyl isobutyl ketone and 28 parts by mass of styrene were added continuously over 4.5 hours. Further, after completion of the addition of maleic anhydride, 14 parts by mass of styrene was added continuously over 0.5 hour. After adding styrene, the temperature of the reaction mixture was raised to 120° C., and the reaction was carried out for 0.5 hour to complete polymerization. Thereafter, 26.6 parts by mass of aniline and 0.5 parts by mass of triethylamine were added to the polymerization solution, and reaction was carried out at 140° C. for 6 hours. The imidizing reaction solution after completion of reaction was fed to a vent type screw extruder, and the volatile component was removed to obtain pellet maleimide based copolymer A-4. Results of analysis for the maleimide based copolymer A-4 are shown in Table 1.

<Production Example of Maleimide Based Copolymer (A-5)>

[0074] To an autoclave having a capacity of about 120 liters equipped with an agitator, 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 parts by mass of t-butylperoxy-2-ethylhexanoate, 0.6 parts by mass of α-methyl styrene dimer, and 12 parts by mass of methyl isobutyl ketone were charged. After replacing the gaseous phase of the system with nitrogen gas, the temperature was raised to 92° C. over 40 minutes with agitation. After raising the temperature, the temperature was kept at 92° C., and a solution prepared by dissolving 23 parts by mass of maleic anhydride and 0.22 parts by mass of t-butylperoxy-2-ethylhexanoate in 50 parts by mass of methyl isobutyl ketone and 28 parts by mass of styrene were added continuously over 4.5 hours. Further, after completion of the addition of maleic anhydride, 14 parts by mass of styrene was added continuously over 0.5 hour. After adding styrene, the temperature of the reaction mixture was raised to 120° C., and the reaction was carried out for 0.5 hour to complete polymerization. Thereafter, 26.6 parts by mass of aniline and 0.5 parts by mass of triethylamine were added to the polymerization solution, and reaction was carried out at 140° C. for 7.5 hours. The imidizing reaction solution after completion of reaction was fed to a vent type screw extruder, and the volatile component was removed to obtain pellet maleimide based copolymer A-5. Results of analysis for the maleimide based copolymer A-5 are shown in Table 1.

<Production Example of Maleimide Based Copolymer (A-6)>

[0075] To an autoclave having a capacity of about 120 liters equipped with an agitator, 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 parts by mass of t-butylperoxy-2-ethylhexanoate, and 12 parts by mass of methyl isobutyl ketone were charged. After replacing the gaseous phase of the system with nitrogen gas, the temperature was raised to 92° C. over 40 minutes with agitation. After raising the temperature, the temperature was kept at 92° C., and a solution prepared by dissolving 23 parts by mass of maleic anhydride and 0.22 parts by mass of t-butylperoxy-2-ethylhexanoate in 50 parts by mass of methyl isobutyl ketone and 28 parts by mass of styrene were added continuously over 4.5 hours. Further, after completion of the addition of maleic anhydride, 14 parts by mass of styrene was added continuously over 0.5 hour. After adding styrene, the temperature of the reaction mixture was raised to 120° C., and the reaction was carried out for 0.5 hour to complete polymerization. Thereafter, 26.6 parts by mass of aniline and 0.5 parts by mass of triethylamine were added to the polymerization solution, and reaction was carried out at 140° C. for 6 hours. The imidizing reaction solution after completion of reaction was fed to a vent type screw extruder, and the volatile component was removed to obtain pellet maleimide based copolymer A-6. Results of analysis for the maleimide based copolymer A-6 are shown in Table 1.

<Production Example of Maleimide Based Copolymer (A-7)>

[0076] To an autoclave having a capacity of about 120 liters equipped with an agitator, 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 parts by mass of t-butylperoxy-2-ethylhexanoate, 0.05 parts by mass of α-methyl styrene dimer, and 12 parts by mass of methyl isobutyl ketone were charged. After replacing the gaseous phase of the system with nitrogen gas, the temperature was raised to 92° C. over 40 minutes with agitation. After raising the temperature, the temperature was kept at 92° C., and a solution prepared by dissolving 23 parts by mass of maleic anhydride and 0.22 parts by mass of t-butylperoxy-2-ethylhexanoate in 50 parts by mass of methyl isobutyl ketone and 28 parts by mass of styrene were added continuously over 4.5 hours. Further, after completion of the addition of maleic anhydride, 14 parts by mass of styrene was added continuously over 0.5 hour. After adding styrene, the temperature of the reaction mixture was raised to 120° C., and the reaction was carried out for 0.5 hour to complete polymerization. Thereafter, 26.6 parts by mass of aniline and 0.5 parts by mass of triethylamine were added to the polymerization solution, and reaction was carried out at 140° C. for 5.5 hours. The imidizing reaction solution after completion of reaction was fed to a vent type screw extruder, and the volatile component was removed to obtain pellet maleimide based copolymer A-7. Results of analysis for the maleimide based copolymer A-7 are shown in Table 1.

<Production Example of Maleimide Based Copolymer (B-1)>

[0077] To an autoclave having a capacity of about 120 liters equipped with an agitator, 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 parts by mass of t-butylperoxy-2-ethylhexanoate, 0.025 parts by mass of α-methyl styrene dimer, and 12 parts by mass of methyl isobutyl ketone were charged. After replacing the gaseous phase of the system with nitrogen gas, the temperature was raised to 92° C. over 40 minutes with agitation. After raising the temperature, the temperature was kept at 92° C., and a solution prepared by dissolving 23 parts by mass of maleic anhydride and 0.22 parts by mass of t-butylperoxy-2-ethylhexanoate in 50 parts by mass of methyl isobutyl ketone and 28 parts by mass of styrene were added continuously over 4.5 hours. Further, after completion of the addition of maleic anhydride, 14 parts by mass of styrene was added continuously over 0.5 hour. After adding styrene, the temperature of the reaction mixture was raised to 120° C., and the reaction was carried out for 0.5 hour to complete polymerization. Thereafter, 26 parts by mass of aniline and 0.5 parts by mass of triethylamine were added to the polymerization solution, and reaction was carried out at 140° C. for 5 hours. The imidizing reaction solution after completion of reaction was fed to a vent type screw extruder, and the volatile component was removed to obtain pellet maleimide based copolymer B-1. Results of analysis for the maleimide based copolymer B-1 are shown in Table 2.

<Production Example of Maleimide Based Copolymer (B-2)>

[0078] To an autoclave having a capacity of about 120 liters equipped with an agitator, 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 parts by mass of t-butylperoxy-2-ethylhexanoate, and 12 parts by mass of methyl isobutyl ketone were charged. After replacing the gaseous phase of the system with nitrogen gas, the temperature was raised to 92° C. over 40 minutes with agitation. After raising the temperature, the temperature was kept at 92° C., and a solution prepared by dissolving 23 parts by mass of maleic anhydride and 0.22 parts by mass of t-butylperoxy-2-ethylhexanoate in 50 parts by mass of methyl isobutyl ketone and 28 parts by mass of styrene were added continuously over 4.5 hours. Further, after completion of the addition of maleic anhydride, 14 parts by mass of styrene was added continuously over 0.5 hour. After adding styrene, the temperature of the reaction mixture was raised to 120° C., and the reaction was carried out for 0.5 hour to complete polymerization. Thereafter, 17.8 parts by mass of aniline and 0.5 parts by mass of triethylamine were added to the polymerization solution, and reaction was carried out at 140° C. for 5 hours. The imidizing reaction solution after completion of reaction was fed to a vent type screw extruder, and the volatile component was removed to obtain pellet maleimide based copolymer B-2. Results of analysis for the maleimide based copolymer B-2 are shown in Table 2.

<Production Example of Maleimide Based Copolymer (B-3)>

[0079] To an autoclave having a capacity of about 120 liters equipped with an agitator, 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 parts by mass of t-butylperoxy-2-ethylhexanoate, 0.025 parts by mass of α-methyl styrene dimer, and 12 parts by mass of methyl isobutyl ketone were charged. After replacing the gaseous phase of the system with nitrogen gas, the temperature was raised to 92° C. over 40 minutes with agitation. After raising the temperature, the temperature was kept at 92° C., and a solution prepared by dissolving 23 parts by mass of maleic anhydride and 0.22 parts by mass of t-butylperoxy-2-ethylhexanoate in 50 parts by mass of methyl isobutyl ketone and 28 parts by mass of styrene were added continuously over 4.5 hours. Further, after completion of the addition of maleic anhydride, 14 parts by mass of styrene was added continuously over 0.5 hour. After adding styrene, the temperature of the reaction mixture was raised to 120° C., and the reaction was carried out for 0.5 hour to complete polymerization. Thereafter, 19 parts by mass of aniline and 0.5 parts by mass of triethylamine were added to the polymerization solution, and reaction was carried out at 140° C. for 6 hours. The imidizing reaction solution after completion of reaction was fed to a vent type screw extruder, and the volatile component was removed to obtain pellet maleimide based copolymer B-3. Results of analysis for the maleimide based copolymer B-3 are shown in Table 2.

<Production Example of Maleimide Based Copolymer (B-4)>

[0080] To an autoclave having a capacity of about 120 liters equipped with an agitator, 20 parts by mass of styrene, 10 parts by mass of acrylonitrile, 5 parts by mass of maleic anhydride, 0.1 parts by mass of t-butylperoxy-2-ethylhexanoate, 0.025 parts by mass of α-methyl styrene dimer, and 12 parts by mass of methyl isobutyl ketone were charged. After replacing the gaseous phase of the system with nitrogen gas, the temperature was raised to 92° C. over 40 minutes with agitation. After raising the temperature, the temperature was kept at 92° C., and a solution prepared by dissolving 23 parts by mass of maleic anhydride and 0.22 parts by mass of t-butylperoxy-2-ethylhexanoate in 50 parts by mass of methyl isobutyl ketone and 28 parts by mass of styrene were added continuously over 4.5 hours. Further, after completion of the addition of maleic anhydride, 14 parts by mass of styrene was added continuously over 0.5 hour. After adding styrene, the temperature of the reaction mixture was raised to 120° C., and the reaction was carried out for 0.5 hour to complete polymerization. Thereafter, 17.8 parts by mass of aniline and 0.5 parts by mass of triethylamine were added to the polymerization solution, and reaction was carried out at 140° C. for 5 hours. The imidizing reaction solution after completion of reaction was fed to a vent type screw extruder, and the volatile component was removed to obtain pellet maleimide based copolymer B-4. Results of analysis for the maleimide based copolymer B-4 are shown in Table 2.

TABLE-US-00001 TABLE 1 A-1 A-2 A-3 A-4 A-5 A-6 A-7 constitution aromatic vinyl monomer unit mass% 50.6 45.6 49.2 50.8 49.5 50.8 50.1 unit vinyl cyanide monomer unit mass% 8.0 8.2 8.0 8.0 8.0 8.1 8.1 unsaturated dicarboxylic mass% 1.4 1.1 0.5 1.4 0.6 1.4 2.0 anhydride monomer unit maleimide monomer unit mass% 39.9 45.1 42.3 39.7 41.9 39.7 39.9 weight average molecular weight (×10.sup.4) Mw 14.1 12.9 14.5 8.4 7.9 16.8 13.6 glass transition temperature ° C. 177 185 179 176 178 176 178 unsaturated dicarboxylic anhydride monomer unit 20.8 14.0 7.2 12.3 4.9 24.6 27.3 unit per one molecule of polymer

TABLE-US-00002 TABLE 2 B-1 B-2 B-3 B-4 constitution aromatic vinyl monomer unit mass% 51.0 50.4 52.0 52.3 unit vinyl cyanide monomer unit mass% 8.1 8.0 17.0 17.3 unsaturated dicarboxylic anhydride mass% 2.4 2.2 1.5 2.2 monomer unit maleimide monomer unit mass% 38.5 39.3 29.6 28.2 weight average molecular weight (×10.sup.4) Mw 13.9 17.0 14.1 15.0 glass transition temperature ° C. 176 177 154 153 unsaturated dicarboxylic anhydride monomer unit unit 34.4 38.2 21.0 33.4 per one molecule of polymer

(Weight Average Molecular Weight)

[0081] The weight average molecular weight of the maleimide based copolymer was measured by the following measurement conditions using GPC method.

[0082] Name of Instrument: SYSTEM-21 Shodex (available from Showa Denko K.K.)

[0083] Column: PL gel MIXED-B, 3 columns connected in series

[0084] Temperature: 40° C.

[0085] Detection: differential refractive index

[0086] Eluent: tetrahydrofuran

[0087] Concentration: 0.8 mass %

[0088] Callibration Curve: standard polystyrene (PS) (available from Polymer Laboratories Ltd) was used for preparation

(Glass Transition Temperature)

[0089] The glass transition midpoint temperature (Tmg) of the maleimide based copolymer was measured in accordance with JIS K-7121 by the following instrument and measurement conditions.

[0090] Name of Instrument: Robot DSC 6200 (available from Seiko Instruments Inc.)

[0091] Temperature Elevation Rate: 10° C./min

(Dicarboxylic Anhydride Monomer Unit Contained in One Polymer Molecule)

[0092] First, content rate of the dicarboxylic anhydride monomer unit contained in the maleimide based copolymer was measured by the following procedure.

[0093] Content rate of the dicarboxylic anhydride monomer unit contained in the maleimide based copolymer was obtained by colorimetric titration method (indicator: phenolphthalein), using methyl ethyl ketone solution of the maleimide based copolymer. Titration was performed with 0.1N ethanolic potassium hydroxide solution.

Definition was made as follows:
A: mass of maleimide based copolymer (g)
B: blank value of the volume of titrated ethanolic potassium hydroxide solution (mL)
C: volume of titrated ethanolic potassium hydroxide solution (mL)
D: molar mass of dicarboxylic anhydride monomer unit

[0094] The content rate (mass %) of the dicarboxylic anhydride monomer unit contained in the maleimide based copolymer was obtained by the equation below.

content rate (F) of dicarboxylic anhydride monomer unit=(C−B)×D/A/100

[0095] Next, from the weight average molecular weight (E) obtained above, the average number of the dicarboxylic anhydride monomer unit contained in one molecule of the maleimide based copolymer was obtained by the equation below.

average number of the dicarboxylic anhydride monomer unit contained in one molecule of the maleimide based copolymer=E×F/D/100

EXAMPLES AND COMPARATIVE EXAMPLES

Examples 1 to 7, Comparative Examples 1 to 4 (Mixing and Kneading of Maleimide Based Copolymer and ABS Resin)

[0096] The maleimide based copolymers A-1 to A-7, and B-1 to B-4, and commercially available ABS resin “GR-3000” (available from Denka Company Limited) were blended by the formulation ratio shown in Table 3 and Table 4. Subsequently, twin screw extruder (TEM-35B, available from Toshiba Machine Co.) was used to extrude the material to obtain pellets. These pellets were used to prepare test pieces using an injection molding machine. Various properties were measured with the test pieces. The results are shown in Table 3 and Table 4.

TABLE-US-00003 TABLE 3 Example 1 2 3 4 5 6 7 maleimide based copolymer used — A-1 A-2 A-3 A-4 A-5 A-6 A-7 evaluation formulation amount GR-3000 mass% 80 80 80 80 80 80 80 of maleimide based mass% 20 20 20 20 20 20 20 property copolymer Charpy Impact with notch kJ/m.sup.2 7.1 8.9 7.3 9.8 7.1 8.2 8.2 Strength Vicat Softening 50N 113 115 114 113 114 113 114 Temperature MFR 220° C., 98N 10.2 12.0 10.0 12.6 12.6 10.1 10.3 glossiness % 94.4 96.5 97.9 97.2 97.8 91.4 91.0

TABLE-US-00004 TABLE 4 Comparative Example 1 2 3 4 maleimide based copolymer used — B-1 B-2 B-3 B-4 evaluation formulation amount GR-3000 mass% 80 80 80 80 of maleimide based mass% 20 20 20 20 property copolymer Charpy Impact Strength with notch kJ/m.sup.2 8.2 7.7 7.4 7.4 Vicat Softening Temperature 50N 113 114 109 110 MFR 220° C., 98N 7.8 9.3 12.7 9.7 glossiness % 89.0 86.9 93.0 88.9

(Charpy Impact Strength)

[0097] The Charpy impact strength was measured using a notched specimen in accordance with JIS K-7111. Edgewise was adopted as the striking direction, relative humidity was 50%, and atmospheric temperature was 23° C. Here, digital impact tester available from Toyo Seiki Seisaku-sho, Ltd. was used as the measuring instrument.

(Vicat Softening Temperature)

[0098] The vicat softening temperature was measured in accordance with JIS K7206. Here, Method 50 (load: 50N, temperature raising speed 50° C./hour) was used, and the test piece having the size of 10 mm×10 mm and 4 mm thickness was used. HDT & VSPT testing device available from Toyo Seiki Seisaku-sho, Ltd. was used as the measuring instrument.

(Melt Mass Flow Rate; MFR)

[0099] Melt mass flow rate was measured at 220° C. with 98 N load in accordance with JIS K7210.

(Glossiness)

[0100] Glossiness was measured in accordance with JIS Z-8741 with a measurement angle of 60°. UGV-4D available from Suga Test Instruments Co., Ltd. was used as the measuring instrument.

[0101] The maleimide based copolymers A-1 to A-7 which satisfy the range of the present invention had sufficienly low number of dicarboxylic anhydride monomer unit contained in the copolymer, and had sufficiently high glass transition temperature. Accordingly, the resin compositions of Example 1 to Example 7 obtained by mixing and kneading these maleimide based copolymers with ABS resin had superior impact resistance, flowability, heat resistance, and surface glossiness. In addition, since the matrix resin of the ABS resin is AS resin, it can be expected that the maleimide based copolymer of the present invention can also achieve a similar effect with the AES resin and ASA resin which have AS resin as the matrix resin. On the other hand, the resin compositions of Comparative Example 1 to Comparative Example 4 obtained by mixing and kneading the maleimide based copolymers B-1 to B-4 which do not satisfy the range of the present invention showed inferior results in at least one of flowability, heat resistance, and surface glossiness.

INDUSTRIAL APPLICABILITY

[0102] The maleimide based copolymer of the present invention can provide a resin composition superior in the balance of heat resistance, impact resistance, flowability, and surface glossiness, by mixing and kneading the maleimide based copolymer with ABS resin, ASA resin, AES resin, and SAN resin. The resin composition obtained can be suitably used for interior components and exterior components of automobiles.