JPH0848840A - Maleimide resin composition with excellent heat resistance and surface impact resistance - Google Patents

Abstract

PURPOSE:To obtain the subject composition comprising a maleimide copolymer, a rubber-reinforced resin and a hard thermoplastic resin having specific physical properties, respectively, in a specified ratio, excellent in heat resistance, surface impact resistance and moldability, and useful for OA equipments, etc. CONSTITUTION:This composition comprises (A) 40-95 pts.wt. of a maleimide copolymer comprising (i) a maleimide monomer, (ii) an aromatic vinylic monomer, and (iii) other vinylic monomers, and having the content of the residual component (i) in an amount of <=0.1%, the whole content of volatile components excluding the component (i) in an amount of <=0.5%, the content of oligomers comprising the component (i) and having a weight-average mol.wt. of 200-1000 in an amount of 2-10%, and an intrinsic viscosity of 0.3-1.5dl/g, (B) 60-5 pts.wt. of a rubber-reinforced resin comprising the graft copolymer of (iv) a butadiene rubber having a number-average particle diameter of 0.15-0.4mum, (v) acetonitrile and (vi) styrene, and having an intrinsic viscosity of 0.4-1.2dl/g in the non-glafted polymer and a graft rate of 20-80%, and (C) 0-300 pts.wt. of another hard thermoplastic resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a maleimide resin composition having excellent heat resistance, surface impact resistance and molding processability.

[0002]

2. Description of the Related Art In the fields of electric equipment and automobiles, the importance of design has increased in recent years. In response to such a tendency, materials used for them are also required to have high mechanical performance, light weight, and excellent appearance. Polycarbonate resins and modified polyphenylene ether resins belonging to the field of materials called engineering plastics are used to meet these requirements, and ABS
A so-called heat-resistant ABS resin having improved heat resistance has been developed and used. In particular, heat-resistant ABS resin has been widely used as a heat-resistant resin material because various improved methods have been developed and it is superior to other engineering plastics in terms of moldability, weather resistance and price.

As a method of improving the heat resistance of ABS resin, acrylonitrile-styrene-α-methylstyrene terpolymer obtained by polymerizing α-methylstyrene in addition to acrylonitrile and styrene, and a rubber-reinforced resin are used. A so-called graft blending method of blending to obtain a resin composition is generally adopted. In this case, the inclusion of α-methylstyrene in the matrix contributes to the improvement of heat resistance. When the content of α-methylstyrene is low, sufficient heat resistance cannot be obtained, and when it is high, the polymerization rate is slow and the polymerization is slow. It has a drawback that it is difficult to obtain a resin of high degree and that a structure in which α-methylstyrene units are chained is generated, so that it is easily decomposed by heat during processing. A heat-resistant ABS resin using a maleimide-based copolymer has been developed for the purpose of overcoming the drawbacks of using α-methylstyrene, and has been proposed in JP-A-61-16955. Also,
As a method for providing a maleimide-based copolymer resin composition having excellent impact resistance, a resin composition using a specific maleimide-based copolymer is disclosed in JP-A-2-196849.

In general, however, heat-resistant ABS resin has a drawback that it is inferior in impact resistance as compared with ABS resin, and as a method for improving it, consideration is given to, for example, JP-A-61-73755 and compatibility of matrix resin and graft polymer. However, JP-A-5-320473, which defines the respective resin compositions, has been proposed, but it is not yet sufficient.

Maleimide copolymers generally have low impact strength, particularly low surface impact strength. Therefore, in actual use, it is used by blending with a rubber-reinforced resin, but the resin composition obtained by blending with the rubber-reinforced resin is usually inferior in heat resistance to the maleimide-based copolymer. There is also a method of blending a maleimide-based copolymer with a rubber-reinforced resin containing a large amount of α-methylstyrene and a maleimide-based monomer unit in order to suppress a decrease in heat resistance, but sufficient surface impact resistance cannot be obtained.

Further, heat-resistant ABS using a maleimide-type copolymer has high heat resistance, but has a drawback that it has lower fluidity at the time of melting than conventional ABS resins and has poor moldability. As a method of improving molding processability, a method of adding a plasticizer, a lubricant, etc. is generally adopted, but it is necessary to keep the dispersed state in the resin constant, and molding products during molding processing. Or the appearance may be damaged on the surface of
There are drawbacks such as reduction of heat resistance, which is the original purpose.

[0007]

Means for Solving the Problems As a result of intensive studies in view of such circumstances, the present inventors have found that a maleimide copolymer having specific physical properties and a rubber-reinforced resin having specific physical properties, and other rubbers as required. It was found that a maleimide resin composition excellent in heat resistance, moldability and surface impact resistance can be obtained by blending a hard thermoplastic resin in a specific ratio, and the present invention has been completed.

That is, according to the present invention, (A) a maleimide monomer unit (a-1) is 15 to 65% by weight, an aromatic vinyl monomer unit (a-2) is 35 to 85% by weight and other components. Vinyl monomer unit (a-3) 0 to 35% by weight (however,
The total of components (a-1) to (a-3) is 100% by weight. ), Wherein the content of the residual maleimide-based monomer in the copolymer is 0.1% by weight or less, and the total volatile content other than the maleimide-based monomer is 0.5% by weight. % Or less, the content of the oligomer component having a weight average molecular weight of 200 to 1000 containing the maleimide monomer unit as a constituent in the copolymer is 2 to 10% by weight, and is unique to the copolymer. 6. Maleimide-based copolymer having a viscosity of 0.3 to 1.5 dl / g, 40 to 95 parts by weight, (B) butadiene rubber (b-1), 35 to 70% by weight, and acrylonitrile (b-2), 7. 5 to 29.25 wt% and styrene (b-3) 16.5 to 48.75 wt% (provided that (b
-1) to (b-3) are 100% by weight in total,
And (b-2) / ((b-2) + (b-3)) is 0.2
It is 5 to 0.45. ) Is a graft copolymer with
The butadiene rubber of the graft copolymer has a number average particle size of 0.15 to 0.4 μm, and the intrinsic viscosity of the ungrafted polymer contained in the graft copolymer is 0.4 to 1.
It is 2 dl / g and the graft ratio of the graft copolymer is 20 to 80%, and the rubber reinforced resin (B) is 60 to 5% by weight, and (C) another hard thermoplastic resin is 0 to 300 parts by weight (the above-mentioned). A maleimide resin composition having excellent heat resistance and surface impact resistance, which is characterized by comprising (A) component and 100 parts by weight of the above (B) component in total.

The present invention will be described in detail below.

The maleimide copolymer, which is the component (A) of the present invention, is a component that improves the heat resistance of the resin composition, and includes a maleimide monomer unit (a-1) and an aromatic vinyl monomer. It is composed of a body unit (a-2) and another vinyl-based monomer unit (a-3).

The maleimide-based monomer constituting the maleimide-based copolymer (A) of the present invention includes maleimide and N-
Methyl maleimide, N-ethyl maleimide, N-propyl maleimide, N-isopropyl maleimide, N-cyclohexyl maleimide, N-phenyl maleimide, N-
Toluyl maleimide, N-xylyl maleimide, N-
Naphthyl maleimide, Nt-butyl maleimide, N-
Examples thereof include orthochlorophenylmaleimide, N-orthomethoxyphenylmaleimide and N-orthobromophenylmaleimide. Of these, N-cyclohexylmaleimide, N-orthochlorophenylmaleimide,
N-ortho-bromomaleimide and N-phenylmaleimide are preferable, and N-phenylmaleimide is particularly preferable.
These maleimide monomers can be used alone or in combination of two or more.

The content of the maleimide monomer unit (a-1) in the maleimide copolymer (A) of the present invention is 15 to 6.
It should be 5% by weight, preferably 20 to 50% by weight. When the content of the maleimide-based monomer unit (a-1) is less than 15% by weight, the heat resistance of the obtained maleimide-based resin composition is low, while when it exceeds 65% by weight, the maleimide-based resin composition is The fluidity of the product is low and the moldability is poor.

Further, the maleimide-based copolymer (A) of the present invention
Examples of the aromatic vinyl-based monomer used to form the styrene include styrene, α-methylstyrene, paramethylstyrene, t-butylstyrene, chlorostyrene, bromostyrene, and vinyltoluene, and styrene is preferable. These aromatic vinyl monomers can be used alone or in combination of two or more.

The content of the aromatic vinyl monomer unit (a-2) in the maleimide copolymer (A) of the present invention is 35 to 35.
It must be in the range of 85% by weight, preferably 40-70% by weight. Aromatic vinyl monomer unit (a-
When the content of 2) is less than 35% by weight, the resulting maleimide resin composition has low fluidity and poor moldability, whereas when it exceeds 85% by weight, the heat resistance of the maleimide resin composition is low. Will be reduced.

Further, other vinyl-based monomers used as an optional component for constituting the maleimide-based copolymer (A) of the present invention include vinyl cyanide-based monomers and acrylic acid ester-based monomers. , Methacrylic acid ester-based monomers, unsaturated dicarboxylic acid anhydride-based monomers, and vinylcarboxylic acid-based monomers. Examples of vinyl cyanide-based monomers include acrylonitrile, methacrylonitrile, and fumaronitrile, with acrylonitrile being preferred. Examples of the acrylate monomer include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, cyclohexyl acrylate and the like. Examples of the methacrylic acid ester-based monomer include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, phenyl methacrylate, isobornyl methacrylate, benzyl methacrylate, trichloroethyl methacrylate, and the like. preferable. Furthermore, as the unsaturated dicarboxylic acid anhydride-based monomer, maleic acid, metaconic acid,
Examples thereof include anhydrous citraconic acid, and maleic anhydride is preferable. Examples of vinylcarboxylic acid-based monomers include acrylic acid and methacrylic acid, with methacrylic acid being preferred. These other vinyl monomers can be used alone or in combination of two or more.

The content of the other vinyl-based monomer unit (a-3) in the maleimide-based copolymer (A) of the present invention is 0 to 35.
% By weight, preferably 0 to 25% by weight. When the content of the other vinyl-based monomer unit (a-3) exceeds 35% by weight, heat resistance, impact resistance, processability and the like of the obtained maleimide-based resin composition will be impaired.

Further, in the maleimide-based copolymer (A) of the present invention, the content of the residual maleimide-based monomer in the copolymer is 0.1% by weight or less, preferably 0.05.
It is necessary that the total volatile component other than the maleimide-based monomer is 0.5% by weight or less, preferably 0.4% by weight or less. If the content of the residual maleimide-based monomer exceeds 0.1% by weight, the copolymer is markedly colored, and thermal defects during processing, bleed-out, and other external defects are likely to occur. Furthermore, examples of the total volatile components other than the maleimide-based monomer in the copolymer include the monomers of the constituent components and the organic solvent, and optionally the polymerization initiator and the residue of the chain transfer agent. The total amount of 0.5
When the content exceeds the weight%, the heat resistance of the resin composition is impaired and problems such as silver streak occur during molding.

Further, the maleimide-based copolymer (A) of the present invention
Is a 2 to 10 oligomer component having a weight average molecular weight of 200 to 1000 containing a maleimide-based monomer as a constituent component.
The content must be in the range of% by weight, preferably 3 to 9% by weight. The content of the oligomer component can be determined from the ratio of the area of peaks to the area of all peaks in the corresponding range from the elution curve of gel permeation chromatography (GPC). Further, the monomer component constituting the oligomer component can be obtained by elemental analysis after the eluate of the oligomer component separated and collected by GPC is dried to remove the solvent. The constituent unit of the oligomer component needs to include a maleimide-based monomer unit, and the oligomer component that does not include the maleimide-based monomer unit reduces the mechanical strength of the maleimide-based resin composition. It is not preferable because it causes. The oligomer component must have a weight average molecular weight of 200 or more, and an oligomer component less than 200 impairs the heat resistance of the resin composition and causes silver streak during molding. The oligomer component having a weight average molecular weight of more than 1000 is not preferable because it has no effect of improving molding processability. Further, when the content of the oligomer component is less than 2% by weight, the moldability of the maleimide resin composition becomes poor, and when the content of the oligomer component exceeds 10% by weight, the maleimide resin composition is deteriorated. It lowers the mechanical strength of the product and causes coloring when heated.

Further, the maleimide copolymer (A) of the present invention must have an intrinsic viscosity of 0.3 to 1.5 dl / g, preferably 0.5 to 1.2 dl / g. . A maleimide-based copolymer having an intrinsic viscosity of less than 0.3 dl / g is inferior in practical mechanical strength and cannot be used in actual use, and a maleimide-based copolymer having an intrinsic viscosity of more than 1.5 dl / g is melted. Has poor fluidity and poor moldability.

As a method for producing the maleimide copolymer (A) of the present invention, a generally known method can be adopted. Further, in producing the copolymer (A) of the present invention, a polymerization initiator, a chain transfer agent, a heat stabilizer and the like can be added if desired. As the polymerization initiator which can be optionally used in producing the copolymer (A) of the present invention, generally known organic peroxides and azo compounds can be used. As the organic peroxide, ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides peroxyesters, peroxydicarbonates and the like are used, methyl ethyl ketone peroxide, Methyl isobutyl ketone peroxide, methyl cyclohexanone peroxide, acetylacetone peroxide, 1,1-dibutylperoxy-
3,3,5-Trimethylcyclohexane, 1,1-dibutylperoxycyclohexane, 2,2-di-t-butylperoxybutane, 2,2,4-trimethylpentyl-2-hydroperoxide, dicumyl peroxide ,
2,5-dimethyl-2,5-di- (t-butylperoxy) hexane, t-butylcumyl peroxide, di-t
-Butyl peroxide, tris- (t-butylperoxy) triazine, di-t-butylperoxyhexahydroterephthalate and the like can be mentioned. As the azo compound, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobisisobutyronitrile,
2,2'-azobis [2- (2-imidazolin-2-yl) propane, azodi-t-octane 2-cyano-2-
Examples include propylazoformamide, dimethyl 2,2'-azobis (2-methylpropinate), 2,2'-azobis (2-hydroxymethylpropionitrile) and the like. Known chain transfer agents that can be optionally used in producing the maleimide-based copolymer of the present invention can be used, and examples thereof include mercaptans, terpene oils, and α-methylstyrene dimer.
As the additive such as a heat stabilizer that can be optionally used in producing the copolymer of the present invention, a generally known additive can be used, but an additive that inhibits polymerization or causes an adverse effect such as coloring is not preferred. .

The rubber-reinforced resin, which is the component (B) used in the present invention, is a component that exhibits impact resistance of the resin composition. The rubber-reinforced resin (B) is a butadiene-based rubber (b
-1) It is obtained by graft-polymerizing acrylonitrile (b-2) and styrene (b-3) in the presence.

Rubber-reinforced resin (B) used in the present invention
The butadiene-based rubber composing the above is 1,3-butadiene 50% by weight or more and 100% by weight or less and 50% by weight or less of a monomer having a CH ₂ ═C <group copolymerizable therewith (total 100% by weight). 50% of 1,3-butadiene homopolymer or 1,3-butadiene unit
It is a copolymer composed of the above. Specific examples of the butadiene rubber include polybutadiene rubber, butadiene-styrene copolymer rubber, butadiene vinyltoluene copolymer rubber, butadiene-acrylonitrile copolymer rubber, butadiene-methacrylonitrile copolymer rubber, butadiene-acryl. Methyl acid copolymer rubber, butadiene-2-ethylhexyl acrylate copolymer rubber, butadiene-methyl methacrylate copolymer rubber, butadiene-
Examples thereof include ethyl methacrylate copolymer rubber. Further, a terpolymer rubber composed of 50% by weight or more of 1,3-butadiene unit is also included, and the glass transition temperature is 0 ° C.
It is as follows.

The number average particle diameter of the butadiene rubber (b-1) used in the present invention is 0.15 to 0.4 μm,
It should preferably be in the range of 0.2 to 0.35 μm. If the number average particle size of the butadiene-based rubber is less than 0.15 μm, the final resin composition will have poor surface impact resistance, while if it exceeds 0.4 μm, the molding appearance and surface impact resistance will be poor. become.

The content of the butadiene rubber (b-1) in the rubber-reinforced resin (B) is 35 to 70% by weight, preferably 100 to 100% by weight of the total of the components (b-1) to (b-3). 40
It is necessary to be in the range of ˜65% by weight. If the content is less than 35% by weight, in order to improve the surface impact resistance of the maleimide resin composition, a large amount of the rubber-reinforced resin must be blended in the resin composition. The heat resistance of the product becomes inferior, while if it exceeds 70% by weight, the molded appearance of the maleimide resin composition becomes poor.

The contents of acrylonitrile and styrene in the rubber-reinforced resin (B) are such that
-2) is 7.5 to 29.25% by weight, and styrene (b-
3) must be in the range of 16.5 to 48.75% by weight, and the ratio represented by (acrylonitrile (b-2) / (acrylonitrile (b-2) + styrene (b-3))) Should be 0.25 to 0.45. (Acrylonitrile (b-2) / (Acrylonitrile (b-
2) When the ratio of styrene (b-3))) is less than 0.25 and exceeds 0.45, the compatibility with the maleimide copolymer (A) is poor, and the surface impact strength of the obtained maleimide resin composition is low. Will also decrease.

The intrinsic viscosity of the non-grafted polymer contained in the rubber-reinforced resin (B) graft copolymer is 0.4-.
It should be in the range of 1.2 dl / g, preferably 0.5-0.9 dl / g. If the intrinsic viscosity of the ungrafted copolymer is less than 0.4 dl / g, the surface impact resistance, which is the object of the present invention, decreases, while the intrinsic viscosity of the ungrafted copolymer exceeds 1.2 dl / g. As a result, the resulting maleimide resin composition has low fluidity and poor moldability.

The graft ratio in the graft copolymer is 2
It should be in the range of 0 to 80%, preferably 25 to 60%, more preferably 30 to 50%. If the graft ratio of the graft copolymer is less than 20%, the graft copolymer is likely to aggregate and the appearance becomes poor. Further, if the graft ratio of the graft copolymer exceeds 80%, the surface impact resistance will decrease.

The method for producing the rubber-reinforced resin (B) of the present invention includes emulsion polymerization, bulk polymerization, solution polymerization, emulsion-suspension polymerization,
Although generally known methods such as emulsion-bulk polymerization can be adopted, emulsion polymerization is preferably used.

Further, a hard thermoplastic resin (C) other than the maleimide copolymer (A) and the rubber-reinforced resin (B) used as an optional component in the present invention is used for improving moldability and appearance. It is a component used, and examples thereof include acrylonitrile-styrene copolymer (AS resin), α-methylstyrene-acrylonitrile copolymer (αSAN), polymethylmethacrylate (P
MMA), a methyl methacrylate-styrene copolymer (MS resin), etc. are mentioned.

The maleimide resin composition of the present invention comprises the above-mentioned maleimide copolymer (A) and rubber-reinforced resin (B).
The former is mixed in an amount of 40 to 95 parts by weight and the latter in an amount of 60 to 5 parts by weight so that the total amount of the components (A) and (B) is 100 parts by weight. When the compounding amount of the rubber-reinforced resin (B) is less than 5 parts by weight, the surface impact resistance of the obtained resin composition is insufficient, and when the compounding amount exceeds 60 parts by weight, the heat resistance of the obtained resin composition decreases. Like The amount of the other hard thermoplastic resin (C) that can be added as an optional component is 0 to 300 parts by weight based on 100 parts by weight of the total of the above components (A) and (B). 300
If it is used in a proportion exceeding the parts by weight, improvement in heat resistance and surface impact resistance of the resin composition finally obtained cannot be expected.

The maleimide resin composition of the present invention contains a hindered phenolic antioxidant or phosphite stabilizer for the purpose of improving thermal stability, and a benzophenone ultraviolet absorber or a hindered amine for improving weather resistance. The system stabilizer and the benzotriazole-based UV absorber may be blended alone or in combination with an amide-based lubricant such as ethylenebisstearylamide or a metal soap for the purpose of improving processability. Further, it is possible to add a flame retardant to obtain a flame retardant resin composition.

The maleimide resin composition of the present invention can be used in various molding processing fields such as injection molding, extrusion molding and vacuum molding, and brightening such as plating treatment, vacuum deposition treatment and sputtering treatment can be performed on the molded product. It is also possible to perform processing.

[0033]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. In addition, "part" in the example is "part by weight"
"%" Represents "% by weight". Further, the measurement of physical properties and performance evaluation in the examples were carried out by the following methods.

(1) Remaining monomer in maleimide type copolymer (A) It was measured by gas chromatography.

(2) Composition of Maleimide Copolymer (A) It was determined by elemental analysis.

(3) Content and Molecular Weight of Oligomer Component in Maleimide Copolymer (A) It was measured by GPC using monodisperse polystyrene as a standard.

(4) Intrinsic Viscosity of Maleimide Copolymer (A) The copolymer was dissolved in N, N-dimethylformamide and measured from a value measured at 25 ° C. using an Ubbelohde viscometer.

(5) Number average particle size of butadiene rubber of rubber reinforced resin (B): Obtained from transmission electron micrograph.

(6) Intrinsic viscosity of rubber-reinforced resin (B) not grafted by weight The latex polymer was coagulated with isopropyl alcohol, the obtained polymer was extracted with acetone, centrifuged and filtered, and then the acetone of the filtrate was filtered. The polymer obtained by evaporating
It was dissolved in N-dimethylformamide and determined from the value measured at 25 ° C. with an Ubbelohde viscometer.

(7) Graft ratio of rubber-reinforced resin (B) A sample obtained by coagulating a latex polymer with isopropyl alcohol was used to remove ungrafted polymer from the polymer by extraction with acetone, and the graft polymer was contained in the sample. Find the quantity,
(Graft polymer content-rubber content) / rubber content x
It was calculated from the formula of 100.

(8) Vicat Softening Temperature of Maleimide Resin Composition ASTM D using a test piece molded by a 2 ounce injection molding machine having a cylinder temperature of 240 ° C. by a 1 ounce injection molding machine.
It measured based on -1525 (5 kg load).

(9) Melt Index of Maleimide Resin Composition According to ASTM D-1238, temperature of 220 ° C., 10 k
It was determined as a discharge amount for 10 minutes under g load.

(10) Surface Impact Resistance of Maleimide Resin Composition The resin composition was treated with a 2 ounce injection molding machine at 260 ° C. for 1 hour.
A 00 mm × 100 mm × 3 mm (thickness) test piece was molded and measured at 23 ° C. at a speed of 3.3 m / sec using a Shimadzu HTM-1 type high-speed impact tester according to ASTM D-3763. However, a striker of 1/2 inch and a support frame of 3 inch were used.

Reference Example (1) Production of Maleimide Copolymer (A) A-1: N-phenylmaleimide 20 was added to a polymerization reactor equipped with a 20-liter stirring device subjected to nitrogen substitution.
Parts, styrene 40 parts, acrylonitrile 20 parts, methyl ethyl ketone 20 parts, 1,1 ′ azobis (cyclohexane-1-carbonitrile) 0.01 parts, t-dodecyl mercaptan 0.05 parts are continuously supplied to 110 ° C. The average residence time is 2 while keeping the temperature in the polymerization vessel constant.
The polymerization reaction liquid was continuously drawn out by a gear pump provided at the bottom of the polymerization reaction device so as to reach the time, and then the polymerization reaction liquid was allowed to stay for about 20 minutes in a heat exchanger kept at 150 ° C. Introduced into a 2-vent type 30 mmφ twin-screw extruder controlled at a temperature of 230 ° C., the first vent section was depressurized to atmospheric pressure and the second vent section was depressurized to 20 Torr to volatilize volatile components and pelletized with a pelletizer. , To obtain pellets of maleimide-based copolymer A-1. Table 1 shows the measurement results of physical properties of the obtained copolymer A-1.

A-2: 0.11 of 1,1'azobis (cyclohexane-1-carbonitrile) was prepared by using the same apparatus as in Reference Example A-1 and setting the temperature of the polymerization reactor at 95 ° C.
Parts and t-dodecyl mercaptan were changed to 0.22 parts, and the same operation as in Reference Example A-1 was performed to obtain pellets of maleimide copolymer A-2. Obtained copolymer A
Table 1 shows the measurement results of the physical properties of -2.

A-3: The temperature of the polymerization reactor is 150 ° C.,
0.001 part of 1,1′azobis (cyclohexane-1-carbonitrile) and t-dodecyl mercaptan were added to 0.001 part.
The same operation as in Reference Example A-1 was carried out except that the amount was changed to 005 parts to obtain pellets of the maleimide copolymer A-3.
Table 1 shows the measurement results of the physical properties of the obtained copolymer A-3.

B-1 to B-7: (2) Production of rubber-reinforced resin (B) A mixed solution (A) in the proportion shown in Table 2 was supplied to a glass polymerization reactor equipped with a 5-liter stirrer. Next, the content of the polymerization reactor was heated to 60 ° C., cumene hydroperoxide in the amount shown in Table 2 was added, and polymerization was carried out until the heat generation in the polymerization reactor disappeared. After the polymerization, the mixture was cooled to 60 ° C., and the mixed solution (B) in the ratio shown in Table 2 was continuously supplied. After the end of the supply and after the heat generation in the polymerization reactor disappeared, 0.03 part of cumene hydroperoxide was added and polymerization was carried out at 60 ° C. for 0.5 hour to complete the polymerization. The obtained polybutadiene rubber reinforced resin latex was coagulated with sulfuric acid, dehydrated and dried to obtain powders of the rubber reinforced resins B-1 to B-7. The number average particle size of the polybutadiene rubber used was 0.3
μm. Table 3 shows the measurement results of the physical properties of the obtained rubber-reinforced resins B-1 to B-7.

[0048]

[Table 2]

[0049]

[Table 3]

Examples 1 and 2, Comparative Examples 1 to 7 Maleimide type copolymer A-obtained in Reference Examples A-1 to A-3
1 to A-3 and the rubber-reinforced resins B-1 to B-7 obtained in Reference Examples B-1 to B-7 were mixed in the proportions shown in Table 4,
Phenolic antioxidant (ANTAGE W-400, trade name,
0.2 parts by Kawaguchi Chemical Co., Ltd. and 0.2 parts by phosphite stabilizer (ADEKA STAB C, trade name, Asahi Denka Co., Ltd.)
Parts were added and mixed well, and then pelletized at 250 ° C. by a 30 mmφ twin-screw extruder to obtain pellets of a maleimide resin composition. Table 4 shows the performance evaluation results of the obtained resin composition.

[0051]

[Table 4]

Example 3, Comparative Examples 8 to 9 Maleimide copolymer A-obtained in Reference Examples A-1 to A-3
1 to A-3, the rubber-reinforced resin B-1 obtained in Reference Example B-1, and an acrylonitrile unit 3 produced by the suspension polymerization method.
AS resin having an intrinsic viscosity of 0.60 dl / g composed of 0% and 70% of styrene units was blended at a ratio as shown in Table 5, and 100 parts of each of the blends was blended with a phenol-based antioxidant as a stabilizer. Oxidizing agent (ANTAGE W-40
0, trade name, manufactured by Kawaguchi Chemical Co., Ltd. 0.2 parts and phosphite stabilizer (Adeka Stab C, trade name, manufactured by Asahi Denka Co., Ltd.) 0.2 part and mixed well, and then 30 mmφ
Was pelletized with a twin-screw extruder at 250 ° C. to obtain pellets of the maleimide resin composition. Table 5 shows the performance evaluation results of the resin compositions obtained.

[0053]

[Table 5]

Comparison between Example 1 and Comparative Example 1 in Table 4, Comparison between Example 1 and Comparative Example 2, Comparison between Example 1 and Comparative Examples 3 to 4, Examples 1 and 2 and Comparative Example 4 to 7 and Table 5
As is apparent from the comparison between Example 3 and Comparative Examples 8 to 9, the maleimide resin composition of the present invention is excellent in heat resistance, surface impact resistance, and molding processability. .

[0055]

EFFECT OF THE INVENTION The maleimide resin composition of the present invention has excellent heat resistance and surface impact resistance as well as excellent moldability, so that it can be used in various fields such as automobiles.
It is extremely useful for applications such as office automation equipment and electric / electronic equipment.

[Table 1]

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Seizo Fujii 20-1 Miyuki-cho, Otake-shi, Hiroshima Mitsubishi Rayon Co., Ltd. Otake Works (72) Inventor Takanori Nakazato 20-1 Miyuki-cho, Otake-shi, Hiroshima Mitsubishi Rayon Co., Ltd. Otake Office

Claims (1)

[Claims] 1. A maleimide-based monomer unit (a) (A)
1) 15 to 65% by weight, aromatic vinyl monomer unit (a
-2) 35 to 85 wt% and other vinyl-based monomer units (a-3) 0 to 35 wt% (provided that (a-1) to (a
-3) The total of the components is 100% by weight. ), Wherein the content of the residual maleimide-based monomer in the copolymer is 0.1% by weight or less, and the total volatile content other than the maleimide-based monomer is 0.5% by weight. % Or less, the content of the oligomer component having a weight average molecular weight of 200 to 1000 containing the maleimide monomer unit as a constituent in the copolymer is 2 to 10% by weight, and is unique to the copolymer. Maleimide-based copolymer having a viscosity of 0.3 to 1.5 dl / g 40 to 95 parts by weight, (B) butadiene rubber (b-1) 35 to 70% by weight
And acrylonitrile (b-2) 7.5 to 29.25% by weight and styrene (b-3) 16.5 to 48.75% by weight (however, the total of components (b-1) to (b-3)) Is 1
00 wt% and (b-2) / ((b-2) +
(B-3)) is 0.25 to 0.45. And a number average particle diameter of the butadiene rubber of the graft copolymer is 0.15 to 0.4 μm,
A rubber-reinforced resin (B) in which the ungrafted polymer contained in the graft copolymer has an intrinsic viscosity of 0.4 to 1.2 dl / g and the graft ratio of the graft copolymer is 20 to 80%. 60 to 5 parts by weight, and (C) another hard thermoplastic resin 0 to 300 parts by weight (based on a total of 100 parts by weight of the component (A) and the component (B)), heat resistance A maleimide resin composition having excellent properties and surface impact resistance.