JPH0725981B2 - Heat resistant and impact resistant resin composition - Google Patents

Description

The present invention relates to a heat resistant and impact resistant resin composition. More specifically, a rubber-reinforced resin obtained by graft-copolymerizing a monomer containing an N-substituted maleimide with a conjugated diene rubber is used.
The present invention relates to a resin composition capable of obtaining a molded article having excellent heat resistance and impact resistance obtained by compounding and kneading a resin.

"Prior Art" It has been well known that a hard resin is compounded with rubber to obtain an impact resistant resin reinforced by the rubber. ABS resin is a representative of this type, but acrylonitrile-styrene copolymer (AS resin) as a hard resin lacks heat resistance, so a hard resin with a higher heat distortion temperature is required. Was there.

As a styrene resin having this high heat distortion temperature, for example, a copolymer of an N-substituted maleimide monomer and an aromatic vinyl monomer is known (LEColeman et al., JP.
(Olymer Sci., Vol. 38, p. 241, published 1959), and a graft copolymer obtained by grafting a monomer mixture of N-allyl-substituted maleimide, an aromatic vinyl monomer and acrylonitrile onto a conjugated diene rubber. A combination and a resin composition containing the graft copolymer have been proposed (US Pat. No. 3,652,726).

However, the copolymer composed of the N-substituted maleimide monomer and the vinyl monomer becomes brittle though the heat distortion temperature increases as the content of the N-substituted maleimide monomer increases. As a method for improving the brittleness, blending with an ABS resin has been proposed (JP-A-57-98536, JP-A-57-131213), but it is not yet sufficient.

In order to improve the impact resistance of the composition in which the N-substituted maleimide monomer / styrene copolymerization resistance and the ABS resin are mixed, the amount of the ABS resin in the composition or the ABS compounded is used. It is necessary to increase the blending amount of the graft rubber in the resin. On the other hand, mechanical properties such as heat resistance and rigidity are AB
It decreases as the amount of S resin or the blending amount of graft rubber in ABS resin increases. Therefore, a resin composition having N-substituted maleimide / styrene copolymer resistance which is excellent in both heat resistance and impact resistance is desired.

"Problems to be Solved by the Invention" The present inventors have the above-mentioned drawbacks existing in conventional rubber-reinforced resins using a copolymer composed of an N-substituted maleimide monomer and a vinyl monomer. The present invention has been achieved as a result of repeated intensive research aimed at solving the above problems. That is, by graft-polymerizing a monomer containing an N-substituted maleimide monomer onto a conjugated diene rubber, by mixing and kneading with an ABS resin having a constant rubber particle diameter, excellent heat resistance and impact resistance are obtained, Above all, the present invention intends to provide a resin composition which can provide a molded product with significantly improved drop weight impact strength.

"Means for Solving Problems" The gist of the present invention is that 25 to 70 parts by weight of a conjugated diene rubber (a) having an average particle size in the latex state of 0.1 to 0.5 µm is added to an aromatic compound. Group vinyl monomers 30-80% by weight, N-substituted maleimide monomers 10-50% by weight, vinyl cyanide monomers 10-40% by weight, and other vinyl monomers copolymerizable with these monomers. Graft copolymer resin obtained by graft polymerizing 30 to 75 parts by weight of a monomer mixture comprising 0 to 30% by weight of the monomer (however, the total amount of the monomer mixture is 100% by weight) by an emulsion polymerization method. (A) 5 to 89 parts by weight, aromatic vinyl monomer 30 to 80% by weight, N-substituted maleimide monomer 10 to 50% by weight, vinyl cyanide monomer 10 to 40% by weight, and these single amounts A monomer mixture consisting of 0 to 30% by weight of other vinyl monomers copolymerizable with the polymer (however, the monomer mixture is 100% by weight), 10 to 90 parts by weight of a copolymer resin (B) formed by polymerization, 2 to 17 parts by weight of a conjugated diene rubber (c), and 55 to 85 parts by weight of an aromatic vinyl monomer. %, And vinyl cyanide monomer 15 to
Monomer mixture consisting of 45% by weight (however, the total amount of monomer mixture is 100% by weight) 83 to 98 parts by weight of graft copolymer resin (C) 1 to 45 parts by weight. , And a monomer mixture comprising 55 to 85% by weight of an aromatic vinyl monomer and 15 to 45% by weight of a vinyl cyanide monomer (however,
The total amount of the monomer mixture is 100% by weight. Is contained in the copolymer resin (D) in an amount of 0 to 50 parts by weight (provided that the copolymer resin (A), (B), (C)
The total of (D) and 100 parts by weight. And a heat-resistant and impact-resistant resin composition.

Hereinafter, the present invention will be described in detail.

The graft copolymer resin (A) constituting the resin composition according to the present invention has an average particle size in the latex state of 0.1 to
To 25 to 70 parts by weight of the conjugated diene rubber (a) in the range of 0.5 μm, 30 to 80% by weight of an aromatic vinyl monomer, 10 to 50% by weight of an N-substituted maleimide monomer, and a single amount of vinyl cyanide Body 10
-40% by weight, and 0-30% by weight of other vinyl monomers copolymerizable with these monomers (I)
(However, the total amount of the monomer mixture is 100% by weight. The same applies to the following.) 30 to 75 parts by weight is graft-polymerized by an emulsion polymerization method. Since this graft copolymer resin (A) contains an N-substituted maleimide monomer component,
It is an impact resistant resin with excellent heat resistance.

The conjugated diene rubber (a), which is a constituent of the graft copolymer resin (A), includes 50% by weight or more of a conjugated diene monomer component such as butadiene, isoprene and chloroprene, and has a glass transition temperature of 0 ° C. The following rubbery polymers are referred to.
Specific examples of the conjugated diene rubber (a) include butadiene rubber (BR), styrene butadiene rubber (SBR), nitrile butadiene rubber (NBR), isoprene rubber (I
Known synthetic rubbers such as R) are listed.

The conjugated diene rubber (a) is in the state of a water-dispersed rubber latex, and the average particle diameter of the rubber is in the range of 0.1 to 0.5 μm. When it is smaller than 0.1 μm, the impact resistance of the obtained graft copolymer resin cannot be improved, which is not preferable. If it is larger than 0.5 μm, emulsion graft polymerization becomes difficult and the stability of the rubber latex is lowered, which is not preferable.

Average of conjugated diene rubbers decomposed into water in the present invention
Particle size means Coulter Electron
Nanosizer (Coulter) manufactured by ics Ltd.  Nano-Sizer^TM)
The latex was dispersed in water at 23 ° C.
It also means the weight average particle size.

Specific examples of the aromatic vinyl monomer that is a component of the monomer mixture (I) include styrene, α-alkylstyrene such as α-methylstyrene, nuclear-substituted alkylstyrene such as p-methylstyrene, vinylnaphthalene. Etc. These may be one kind or a mixture of two or more kinds.

The ratio of the aromatic vinyl monomer in the monomer mixture (I) is 30 to 80% by weight. If this ratio exceeds 80% by weight, the heat resistance of the resin produced will be reduced, or the miscibility will be poor when mixed with other hard resins. If it is less than 30% by weight, the characteristics of the graft-polymerized resin change and the kinds of other copolymer resins to be mixed are limited, which is not preferable.

Examples of the N-substituted maleimide monomer include maleimide and N-
Phenylmaleimide, N- (o-methylphenyl) maleimide, N- (m-methylphenyl) maleimide, N-
At least one selected from the group consisting of (p-methylphenyl) maleimide and N-cyclohexylmaleimide.
Seed monomers are mentioned. Among these, N-phenylmaleimide is particularly preferable.

The N-substituted maleimide monomer is added to the monomer mixture (I).
It is contained in the range of 10 to 50% by weight. When the content exceeds 50% by weight, the copolymer resin becomes inhomogeneous and the desired graft copolymer resin cannot be obtained. When it is less than 10% by weight, the heat resistance is insufficient and the effect of copolymerizing the N-substituted maleimide monomer is not obtained.

Specific examples of the vinyl cyanide monomer include acrylonitrile and methacrylonitrile. They are,
It may be one kind or a mixture of two or more kinds. The ratio of the vinyl cyanide monomer in the monomer mixture (I) is
It should be in the range of 10-40% by weight. If it deviates from this range, the dispersibility of the graft-polymerized resin and the other copolymer resin may be lowered, or the mechanical properties and chemical resistance of the molded article obtained from the composition may be lowered, which is not preferable. .

Examples of the other vinyl monomer copolymerizable with these monomers include acrylic acid esters, methacrylic acid esters, and mixtures thereof.

The vinyl monomer copolymerizable with these monomers is contained in the monomer mixture (I) in an amount of 30% by weight or less. 30
When the content exceeds the weight%, not only is it necessary to change the reaction conditions of the graft polymerization, but also the physical properties of the graft-polymerized resin change, which is not preferable.

The graft copolymer resin (A) in the present invention is prepared by mixing 25 to 70 parts by weight of the conjugated diene rubber (a) with 30 to 75 parts by weight of the monomer mixture (I). Is subjected to emulsion polymerization and graft-polymerized.
When the ratio of the above-mentioned parts by weight of the conjugated diene rubber (a) and the monomer mixture (I) is out of the above range, the copolymer of the monomer mixture (I) becomes a conjugated diene rubber particle. It is not preferable because the surface cannot be covered or the proportion of the conjugated diene rubber in the graft copolymer resin decreases.

In the case of this graft polymerization, a method such as a suspension polymerization method, a solution polymerization method, or a bulk polymerization method can be used in combination with an emulsion polymerization method as a main component. When the emulsion polymerization method is used, the usual emulsion polymerization method using water as a medium is performed. At this time, the monomer mixture (I), the molecular weight modifier, the emulsifier, the polymerization initiator and the like are added in accordance with the polymerization rate of the emulsion polymerization.
It is preferable to adopt a method of appropriately dividing it and adding it to the polymerization system over time.

In carrying out the graft polymerization in combination with a method other than the emulsion polymerization method, first, the surface of the conjugated diene rubber particles is coated with a hard resin by the emulsion polymerization method, and it becomes possible to disperse only the rubber particles. At this time, it is advisable to adopt a method in which the emulsion polymerization system is transferred to a suspension system, a solution system or a bulk polymerization system and the graft polymerization is continued.

For the polymerization system that has completed the graft polymerization, a known appropriate post-treatment, for example, salting out, separation, washing, drying, mixing, pelletizing, and the like are appropriately combined to perform the graft copolymer resin ( A) can be obtained.

Copolymer resin (B) constituting the resin composition according to the present invention
30% to 80% by weight of aromatic vinyl monomer, 10% to 50% by weight of N-substituted maleimide monomer, and 10% to 10% of vinyl cyanide monomer.
It is obtained by polymerizing a monomer mixture (II) consisting of 40% by weight and 0 to 30% by weight of another vinyl monomer copolymerizable with these monomers. The copolymer resin (B) is N
Since it contains a substituted maleimide monomer component, it is a thermoplastic hard resin having excellent heat resistance.

Aromatic vinyl monomers, N-substituted maleimide monomers, vinyl cyanide monomers, and other vinyl monomers copolymerizable with these monomers, which are the constituent components of the copolymer resin (B). The term “mer” has the same meaning as each of the vinyl monomers exemplified above as the component of the monomer mixture (I). The proportion of each of these vinyl monomers in the monomer mixture (II) is in the same range as the range limited by the monomer mixture (I). However, the composition of the monomer mixture (II) only needs to be within the above range and does not have to be exactly the same as the composition of the monomer mixture (I).

The copolymer resin (B) has an appropriate molecular weight and composition selected appropriately so that the molded product obtained from the resin composition of the present invention has the desired excellent heat resistance and impact resistance. Good to set.

The polymerization method and polymerization conditions of the above monomer mixture (II) are
For example, known acrylonitrile-styrene copolymer (AS
Resin), emulsion polymerization method, suspension polymerization method,
A method such as a solution polymerization method and a bulk polymerization method can be appropriately selected from a batch system and a continuous system.

The polymerization of the monomer mixture (II) can be carried out in the same polymerization system at the same time as the graft polymerization of the graft copolymer resin (A), but usually it is carried out by separately setting the polymerization conditions. Is preferred.

The graft copolymer resin (C) constituting the resin composition of the present invention means that 2 to 17 parts by weight of the conjugated diene rubber (c),
A monomer mixture (III) 83 comprising 55 to 85% by weight of an aromatic vinyl monomer and 15 to 45% by weight of a vinyl cyanide monomer.
What is obtained by graft polymerization of ˜98 parts by weight.
The graft copolymer resin (C) is a kind of acrylonitrile-butadiene-styrene copolymer (ABS resin),
It is a thermoplastic resin with excellent impact resistance.

The graft rubber of the conjugated diene rubber (c) constituting the graft copolymer resin (C) has an average particle diameter of 0.5 μm.
It is preferable to be in the range of over 5 μm. Outside of this range, the impact resistance of the resin composition obtained in combination with the graft copolymer resin (A), especially the falling weight impact strength, cannot be improved, which is not preferable. In order to increase the impact resistance particularly effectively, it is particularly preferable to select the average particle size of the graft rubber of the graft copolymer resin (C) from the range of 0.7 to 4 μm.

In the present invention, the average particle size of the grafted rubber of the conjugated diene rubber component means Coulter Elec.
ectronics Ltd.) "Coulter Counter Model TA
II "is a weight average particle diameter measured at 23 ° C of a solution prepared by dissolving a small amount of a graft copolymer in dimethylformamide and adding a trace amount of potassium thiocyanate.

The conjugated diene rubber (c), which is a constituent of the graft copolymer resin (C), means that it contains 50% by weight or more of a conjugated diene monomer component such as butadiene, isoprene and chloroprene, and has a glass transition temperature of 0 ° C. The following rubbery polymers are referred to.
Specific examples of the conjugated diene rubber (c) include butadiene rubber (BR), styrene-butadiene rubber (SBR),
Synthetic rubbers such as nitrile-butadiene rubber (NBR) and isoprene rubber (IR) are listed.

The aromatic vinyl monomer and vinyl cyanide monomer, which are the components of the above-mentioned monomer mixture (III), are each exemplified as the components used in the production of the graft copolymer resin (A) earlier. It is synonymous with the vinyl monomer of. The monomer mixture (III) comprises 55 to 85% by weight of an aromatic vinyl monomer and 15 to 45% by weight of a vinyl cyanide monomer.

If it is out of this range, the properties of the graft-polymerized resin change, the miscibility with other copolymer resins to be mixed becomes poor, and the heat resistance or impact resistance of the intended resin composition is lowered, which is preferable. Absent.

The monomer mixture (III) is added in an amount of 83 to 98 parts by weight to 2 to 17 parts by weight of the conjugated diene rubber (c), and graft polymerization is carried out.

When the amount of the monomer mixture (III) to be added at this time is less than 83 parts by weight and the amount of the conjugated diene rubber (c) exceeds 17 parts by weight, the graft rubber particle diameter is set within the above range. It becomes difficult to do so, and the appearance of the graft copolymer is also deteriorated, which is not preferable.

When the amount of the monomer mixture (III) is more than 98 parts by weight and the amount of the conjugated diene rubber (c) is less than 2 parts by weight, only the resin not graft-polymerized increases and the graft copolymer resin This is not preferable because the concentration of the conjugated diene rubber component in (3) will decrease.

This graft polymerization is a known bulk polymerization method, solution polymerization method,
A suspension polymerization method and / or an emulsion polymerization method or the like can be employed in a batch or continuous manner, and these methods and schemes can be appropriately combined and employed. As an example of the bulk-suspension polymerization method, first, a solution system in which a conjugated diene rubber is completely dissolved in a monomer mixture is once formed, and then,
Polymerization is carried out while applying shear stress. Then, after the graft rubber particles are stably formed, the process proceeds to suspension polymerization to complete the polymerization and recover the unreacted monomer.

In this graft polymerization, a known polymerization initiator of acrylonitrile-rubber component-styrene copolymer, and
If necessary, auxiliary agents such as a molecular weight modifier, a stabilizer, an antioxidant, a surfactant and a suspension stabilizer can be used in appropriate combination.

The copolymer resin (D) constituting the composition of the present invention comprises a monomer mixture (IV) comprising 55 to 85% by weight of an aromatic vinyl monomer and 15 to 45% by weight of a vinyl cyanide monomer. Manufactured by polymerization. This copolymer resin (D) is a known acrylonitrile-styrene copolymer (AS resin) having an appropriate molecular weight and composition in accordance with the resin composition according to the present invention.

The polymerization method and polymerization conditions of the above monomer mixture (IV) are
According to publicly known AS resin manufacturing technology, a method such as an emulsion polymerization method, a suspension polymerization method, a solution polymerization method or a bulk polymerization method can be appropriately selected from a batch method or a continuous method. The aromatic vinyl monomer and the vinyl cyanide monomer, which are the components of the monomer mixture (IV), have the same meanings as the vinyl monomers exemplified above.

The proportion of each of these vinyl monomers in the monomer mixture (IV) is in the same range as the range limited by the monomer mixture (III). However, the composition of the monomer mixture (IV) may be within the above range, and the monomer mixture (III)
It does not necessarily mean that the composition is exactly the same. Outside of this range, not only the polymerization conditions need to be changed, but also the type and composition of other graft copolymer resin to be blended are limited, which is not preferable.

The resin composition according to the present invention comprises 5 to 89 parts by weight of the above-described graft copolymer resin (A), 10 to 90 parts by weight of the copolymer resin (B), and the graft copolymer resin (C). 1 to 45 parts by weight, and 0 to 50 parts by weight of the copolymer resin (D) (however, the total amount of the copolymer resins (A), (B), (C) and (D) is 100 parts by weight). Weigh in the range of 1) and mix. The mixture is preferably further subjected to a melt-kneading step. If the blending amount of each copolymer resin is out of the above range, the desired heat resistance and impact resistance cannot be obtained, and a thermoplastic resin composition having good processability cannot be obtained.

In this blending, the ratio of the conjugated diene rubber (a) component derived from the graft copolymer resin (A) and the conjugated diene rubber (c) component derived from the graft copolymer resin (C) is such that It is preferable to select and combine the ratio so that the ratio of the conjugated diene rubber (a) component / the conjugated diene rubber (c) component = 97/3 to 50/50. Impact resistance when the content of the conjugated diene rubber (c) component is too small or too large, outside the compounding range of the conjugated diene rubber (a) component and the conjugated diene rubber (c) component. Since it tends to decrease, it is preferable to select and combine within the above range.

Further, the total of the conjugated diene rubber (a) component and the conjugated diene rubber (c) component contained in the resin composition according to the present invention is in the range of 5 to 40% by weight based on the entire resin composition. It is preferable to mix them so as to be within. If the total amount of the conjugated diene-based rubber (a) component and the conjugated diene-based rubber (c) component is out of the above range and is too small, the impact resistance tends to decrease.
Rigidity, melt flowability, etc. are deteriorated and the appearance of the molded product is adversely affected. Therefore, the above range is preferable.

To mix and knead the graft copolymer resin (A), the copolymer resin (B), the graft copolymer resin (C) and the copolymer resin (D), a known mixing and kneading method may be used. Good.

For example, one or a mixture of two or more of these copolymer resins in the form of powder, beads, or pellets is added to an extruder such as a single-screw extruder or a twin-screw extruder, or a Banbury mixer, a pressure kneader, a twin extruder. With a kneader such as this roll,
It can be a resin composition. Depending on the case, one or two of these copolymer resins which have been polymerized are also used.
It is also possible to employ a method in which at least one seed is mixed in an undried state, precipitated, washed, dried and kneaded.

As the order of this mixing and kneading, four kinds of component resins may be mixed and kneaded at the same time.
One kind or two or more kinds may be mixed and kneaded, and one kind or two or more kinds may be separately kneaded and then kneaded to obtain a desired resin composition.

Further, if the volatile part remains in the resin composition, the heat resistance may be deteriorated. Therefore, in the case of mixing and kneading using an extruder, it is preferable to perform a devolatilization operation by a vacuum vent or the like. .

The resin composition according to the present invention can be directly used for molding and the like. In addition, other thermoplastic resins such as polystyrene, AS resin, ABS resin, polymethylmethacrylate, polycarbonate, polyamide, polybutylene terephthalate, polyphenylene oxide, acrylonitrile, EPDM rubber / styrene copolymer (AES resin), etc. are mixed and kneaded. Then, it can also be used as a heat resistant and impact resistant resin.

The resin composition according to the present invention includes a type and amount of a lubricant, a release agent, a colorant, an antistatic agent, which does not impair the properties of the resin.
Various resin additives such as a flame retardant, an ultraviolet absorber, a light resistance stabilizer, a heat resistance stabilizer, and a filler can be added in an appropriate combination.

The resin composition according to the present invention includes an injection molding method, an extrusion molding method,
By various processing methods such as the compression molding method, it can be molded into automobile parts, electric parts, industrial parts and the like, and can be used in applications where excellent heat resistance and impact resistance are required.

"Effects of the Invention" As described above, the present invention has particularly remarkable effects as described below, and its industrial utility value is extremely large.

(1) The resin composition according to the present invention comprises, as constituent components of the graft copolymer resin (A) and the copolymer resin (B),
Since both these constituent components contain an appropriate amount of N-substituted maleimide monomer, they have excellent heat resistance.

(2) The resin composition according to the present invention has a conjugated diene rubber (a) component in the graft copolymer resin (A) and a conjugated diene rubber (c) component in the kraft copolymer resin (C), respectively. It is used as a thermoplastic resin with excellent impact resistance, especially falling weight impact strength because it is compounded by optimizing the rubber component ratio, the total compounding amount of each rubber component, and each rubber particle diameter. be able to.

(3) Since the resin composition according to the present invention contains the graft copolymer resin (C) and the copolymer resin (D), AB
As a type of S resin, it has good processability and chemical resistance.

(4) The resin composition according to the present invention has excellent compatibility with other hard thermoplastic resins, and thus is kneaded and mixed to produce another type of resin composition having excellent heat resistance and impact resistance. be able to.

"Examples" Next, the present invention will be described by way of examples, but the present invention is not limited to the following examples unless it exceeds the gist. In the following example, "part" means
Represents "parts by weight".

Production Example (1) Production of Graft Copolymer Resin (A) 45 parts of styrene (hereinafter abbreviated as St), 30 parts of N-phenylmaleimide (hereinafter abbreviated as N-PMI), acrylonitrile (hereinafter abbreviated as AN) A monomer mixture (I) consisting of 25 parts and 0.6 part of terpinolene (molecular weight modifier) was prepared.

In a glass flask equipped with a stirrer, a reflux condenser, a thermometer, and an auxiliary agent addition device, styrene-butadiene-rubber latex (St content 10% by weight, rubber solid content concentration 30% by weight,
Rubber particle diameter 0.30 μm) 333 parts (including water) and 150 parts of deionized water were charged, and the mixture was stirred under a nitrogen stream while stirring.
The internal temperature was raised to 80 ° C.

Then, 2 parts of an aqueous solution of potassium persulfate (hereinafter abbreviated as KPS) (containing 0.1 part of KPS) was continuously added to this flask for 240 minutes, and the total amount of the monomer mixture (I) was continuously added for 210 minutes. Then, the polymerization was started at the same temperature. 60 minutes and 180 minutes after the initiation of the polymerization, 0.2 part of sodium dodecylbenzenesulfonate was added to the polymerization system. After the polymerization was started, the graft polymerization reaction was continued for 360 minutes at the same temperature.

The latex obtained after the completion of the graft polymerization reaction was
The mixture was added dropwise to a 4% magnesium sulfate aqueous solution heated to ° C for salting out, dehydrated and dried to obtain a powdery maleimide-based graft copolymer resin (A).

(2) Manufacture of Copolymer Resin (B) A polymerization tank equipped with a reflux condenser, a stirrer, and a monomer supply device was charged with 100 parts of deionized water in which 0.03 part of a polyvinyl alcohol-based suspending agent was dissolved. Furthermore, a monomer mixture consisting of St30 parts, AN15 parts, and N-PMI20 parts was charged into this polymerization tank together with 0.4 parts of terpinolene (molecular weight modifier), and the temperature inside the tank was maintained at 60 ° C while stirring under a nitrogen stream. Then, 0.06 part of α, α′-azobisisobutyronitrile was added as a polymerization initiator to start the polymerization reaction.

Then, immediately after starting the polymerization reaction, start the addition from the monomer supply device to the polymerization tank, St15 parts, AN10 parts,
N-PMI 10 parts, α, α'-azobisisobutyronitrile
The rest of the monomer mixture, to which 0.04 parts and 0.2 parts terpinolene had been added, was continuously added over 120 minutes. Further, when 15 minutes have elapsed from the start of the polymerization reaction, 0.03 parts of a polyvinyl alcohol-based suspending agent was added to the polymerization tank, and after 30 minutes, 60 minutes, and 90 minutes after starting the polymerization reaction, After 120 minutes, 0.0225 parts of each polyvinyl alcohol-based suspending agent was added to the polymerization tank. During this period, the temperature of the polymerization system was maintained at 60 ° C.

180 minutes after starting the polymerization reaction, 0.03 parts of acrylic acid / 2-ethylhexyl acrylate copolymer (suspension agent) and 0.26 parts of sodium sulfate were added to the polymerization tank, and the polymerization system was completed in 30 minutes. The temperature was raised to 75 ° C. and the polymerization reaction was continued at the same temperature for 120 minutes. Subsequently, the temperature of the polymerization system was raised to 80 ° C., while carrying out stripping under a nitrogen gas stream, a polymerization reaction was carried out for 120 minutes, the resulting copolymer resin slurry was passed through, dehydrated and dried. Thus, 86.5 parts by weight of a granular maleimide copolymer resin was obtained.

To the maleimide-based copolymer resin thus obtained,
Stearyl-β- (3,5-di-t-butyl-4-hydroxyphenyl) propionate (antioxidant) and magnesium stearate (lubricant) were added in an amount of 0.1 part per 100 parts of the copolymer resin, and vented. The mixture was kneaded while being degassed with an attached extruder and pelletized to obtain a copolymer resin (B).

(3) Production of graft copolymer resin (C) 155 parts of butadiene rubber (Diene NF-35, manufactured by Asahi Kasei Co., Ltd.) AN211 in an autoclave equipped with an Ikari type stirring device.
Parts and a mixture of St 634 parts. To this was added 0.13 parts tert-butyl peracetate, 0.5 parts di-tert-butyl peroxide and 0.7 parts stabilizer mixture to initiate the polymerization. Heat the mixing part to 100 ° C under a nitrogen atmosphere, 100 per minute
The polymerization was allowed to proceed under rotary agitation, during which time terpyrenone was added at a rate of about 1 part per 60 minutes over a period of 300 minutes from the start of the polymerization, and finally 5 parts.

When the monomer conversion reached about 30%, the polymerization mixture (syrup) was placed in 1200 parts of deionized water, and an autoclave containing an aqueous solution of 3 parts of a suspending agent (acrylic acid / 2-ethylhexyl acrylate copolymer) ( 3 sheets, equipped with a reciprocating blade stirrer). After purging with nitrogen, the suspension is
Polymerization for 120 minutes under conditions of 500 ℃ and 500 rpm, 150 ℃
At 60 minutes, stripping was performed. The obtained resin was washed with water and dried to obtain about 990 parts of a graft copolymer resin (C). The rubber particle diameter in this graft copolymer resin was about 1.9 μm.

(4) Copolymer resin (D) Acrylonitrile-styrene copolymer (AS resin, SAN
-C, manufactured by Mitsubishi Monsanto Kasei Co., Ltd. was used.

Examples 1 to 4 Comparative Examples 1 to 3 Graft copolymer resin (A), copolymer resin (B), graft copolymer resin (C) and copolymer obtained by the method described in the above production examples. The resin (D) was kneaded according to the blending ratio (parts) shown in Table 1 while degassing from the vent using a uniaxial extruder to prepare pellets of the resin composition.

The pellets of this resin composition were molded into a test piece for measuring physical properties by a thermoplastic resin injection molding machine. Tensile strength, Izod impact strength (with notch), falling weight impact strength, Vicat softening point and melt flow rate were measured for the molded test pieces by the methods described in Table 1. The results are shown in Table 1.

Table 1 reveals the following.

(1) The resin composition according to the present invention comprises, as constituent components of the graft copolymer resin (A) and the copolymer resin (B),
Since it contains a proper amount of N-substituted maleimide monomer, it has excellent heat resistance (see Examples 1 to 4).

On the other hand, the graft copolymer resin (C) containing no N-substituted maleimide monomer component has low heat resistance (see Comparative Example 1).

(2) The resin composition according to the present invention has a conjugated diene rubber (a) component in the graft copolymer resin (A) and a conjugated diene rubber (c) component in the graft copolymer resin (C), respectively. The rubber component ratio, the total compounding amount of each rubber component, and each rubber particle diameter are optimized and compounded, so that they have excellent impact resistance, and particularly, a large falling weight impact strength (Example 1 ~ 4).

Further, the resin composition obtained outside the scope of the present invention has poor impact resistance (see Comparative Example 2) or poor tensile strength and moldability (melt flow rate) (see Comparative Example 3).

Claims (4)

[Claims] 1. An average particle size in a latex state is 0.1 to 0.5.
Aromatic vinyl monomer 30 to 80% by weight, N-substituted maleimide monomer 10 to 50% by weight, vinyl cyanide monomer to 25 to 70 parts by weight of conjugated diene rubber (a) in the range of μm. 10-40
30 to 75% by weight, and a monomer mixture consisting of 0 to 30% by weight of another vinyl monomer copolymerizable with these monomers (however, the total amount of the monomer mixture is 100% by weight). Parts by graft polymerization by emulsion polymerization (A) 5 to 89 parts by weight, aromatic vinyl monomer 30 to 80% by weight, N-substituted maleimide monomer 10 to 50% by weight , A vinyl cyanide monomer 10 to 40% by weight, and another vinyl monomer copolymerizable with these monomers 0 to 30% by weight (however, the total amount of the monomer mixture is 100%). % By weight) to 10 to 90 parts by weight of a copolymer resin (B) formed by polymerization, 2 to 17 parts by weight of a conjugated diene rubber (c), and 55 to 85% by weight of an aromatic vinyl monomer. , And vinyl cyanide monomer 15 ~
Monomer mixture consisting of 45% by weight (however, the total amount of monomer mixture is 100% by weight) 83 to 98 parts by weight of graft copolymer resin (C) 1 to 45 parts by weight. , And a monomer mixture comprising 55 to 85% by weight of an aromatic vinyl monomer and 15 to 45% by weight of a vinyl cyanide monomer (however,
The total amount of the monomer mixture is 100% by weight. A copolymer resin (D) of 0 to 50 parts by weight, (provided that the copolymer resin (A), (B), (C)
The total of (D) and 100 parts by weight. And a heat-resistant and impact-resistant resin composition. 2. The average particle diameter of the graft rubber of the conjugated diene rubber (c) derived from the graft copolymer resin (C) is 0.1.
The heat-resistant and impact-resistant resin composition according to claim (1), characterized in that it is more than 5 μm and 5 μm or less. 3. The ratio of the conjugated diene rubber (a) component derived from the graft copolymer resin (A) and the conjugated diene rubber (c) component derived from the graft copolymer resin (C) is By weight ratio, conjugated diene rubber (a) component / conjugated diene rubber (c)
The heat resistance and impact resistance according to any one of claims (1) and (2), characterized in that the composition is blended within the range of 97/3 to 50/50. Resin composition. 4. The total of the conjugated diene rubber (a) component and the conjugated diene rubber (c) component is in the range of 5 to 40% by weight based on the entire resin composition. The heat resistant and impact resistant resin composition according to any one of claims (1) to (3).