JPH10298375A - Rubber-modified heat-resistant styrene-based resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition, good in balance among physical properties such as impact strength and heat resistance by including a specific styrene-based copolymer containing imide groups and graft rubber particles dispersed in the continuous phase thereof. SOLUTION: This composition comprises (A) a styrene-based copolymer comprising a styrene-based monomer, an acrylonitrile-based monomer and a maleimide-based monomer and, as necessary, a monomer copolymerizable therewith and containing imide groups and (B) graft rubber particles, dispersed in the continuous phase of the component A and containing emulsion graft rubber particles having 0.05-0.8 μm weight-average particle diameter and bulk or solution graft rubber particles having 0.1-10 μm weight-average particle diameter. The content of a dimer or a trimer composed of the styrene-based monomer and/or the acrylonitrile-based monomer in the composition is <=20,000 ppm and the rubber content is 5-45 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber-modified heat-resistant styrenic resin composition, and particularly to a rubber-modified heat-resistant styrenic resin composition having excellent impact strength, and a good balance of physical properties such as tensile strength, fluidity and heat resistance. The present invention relates to a resin composition having no mold stain.

[0002]

2. Description of the Related Art Conventionally, rubber-modified styrenic resins (such as ABS resins) have been evaluated well in terms of moldability, physical properties and mechanical properties, and particularly, those molded articles have excellent appearance and high gloss. Due to its properties, it is widely used in electric and electronic products and vehicle parts. However, the demand for quality of the user is further increased, and it is required that the rubber-modified styrenic resin currently used is further improved in impact strength and heat resistance. Also,
In order to improve the appearance of the gate portion of an injection molded product, injection molding is often performed at a high temperature using a pin gate so as to be more suitable for fully automatic operation. However, since the pinhole of this pin gate is extremely small, it is quite difficult to injection-mold a resin melt having a high viscosity through the pinhole. For this reason, the demand for high fluidity of styrenic resins is also increasing. On the other hand, automated injection molding
This reduces the demand for human labor and enables high-efficiency production. However, oil-like substances may adhere to the mold during injection molding of the styrenic resin, which must be eliminated. Then, in order to clean the dirty mold, the automatic production must be stopped every time, so that the efficiency is reduced. As mentioned above, it is important in this field how to keep the styrene resin in good balance of physical properties such as high impact strength, heat resistance, tensile strength, fluidity, etc. It is an issue.

[0003]

SUMMARY OF THE INVENTION In view of the above, the present invention relates to a rubber modified rubber having a good balance of physical properties such as impact strength, heat resistance, tensile strength and fluidity, and having no mold contamination. An object is to provide a heat-resistant styrenic resin composition.

[0004]

The present invention provides a rubber-modified heat-resistant styrenic resin composition comprising a styrenic copolymer containing an imide group (A) and graft rubber particles dispersed in its continuous phase. In the product, a styrene-based copolymer (A) containing an imide group is a styrene-based monomer, an acrylonitrile-based monomer, a maleimide-based monomer, and, if necessary, a monomer copolymerizable therewith. A graft rubber particle comprising: (1) a weight average particle size of 0.05 to 0.8;
and (2) bulk (or solution) graft rubber particles (C) having a weight average particle diameter of 0.1 to 10 μm, and rubber in the emulsion graft rubber particles (B). And the proportion of rubber in the bulk (or solution) graft rubber particles (C) is 98 to 70 area% / 2 to 3
0% by area, the average thickness of the styrene copolymer grafted on the surface of the emulsified graft rubber particles (B) is 30 to 160 °, and the mass (or solution) of the graft rubber particles (C) The average thickness of the styrene-based copolymer grafted on the surface is 90 to 350 °, and a dimer and a trimer of a styrene-based monomer and / or an acrylonitrile-based monomer in the composition. Content of 20,000
The present invention provides a rubber-modified heat-resistant styrenic resin composition, which is less than 1 ppm and a rubber content is 5 to 45% by weight.

The styrenic copolymer (A) containing an imide group is composed of 89 to 20 parts by weight of a styrene monomer, 5 to 50 parts by weight of an acrylonitrile monomer, and 1 to 45 parts by weight of a maleimide monomer. Parts and, if necessary, 0 to 40 parts by weight of a monomer copolymerizable therewith are produced by bulk, solution, suspension or emulsion polymerization, preferably by a bulk or solution polymerization method. The styrenic copolymer (A) containing an imide group has a weight average molecular weight of 60,00.
0 to 400,000, preferably 80,000 to
300,000. Examples of the styrene monomer in the imide group-containing styrene copolymer (A) of the present invention include styrene, α-methylstyrene, p-chlorostyrene, p-tert-butylstyrene, p-methylstyrene, o-chlorostyrene, m-chlorostyrene, 2,
5-dichlorostyrene, 3,4-dichlorostyrene,
Examples include 2,4,6-tribromostyrene and 2,5-dibromostyrene, and styrene or α-methylstyrene is particularly preferred.

Specific examples of the acrylonitrile-based monomer used in the present invention include acrylonitrile, α-methylacrylonitrile and the like, and preferably acrylonitrile. In the present invention, copolymerizable monomers used for the styrene copolymer (A) include, for example, methacrylate monomers, acrylic acid, methylacrylic acid, and maleic anhydride. And, as the methacrylate monomer, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, benzyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, dodecyl methacrylate, 2-hydroxyethyl methacrylate And glycidyl methacrylate, dimethylaminoethyl methacrylate, methyl acrylate, butyl acrylate and the like, and preferably methyl methacrylate and butyl acrylate.

Examples of the maleimide monomer include maleimide, N-methylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-hexylmaleimide, N-octylmaleimide, N-dodecylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-2,3-dimethylphenylmaleimide, N
-2,4-dimethylphenylmaleimide, N-2,3-
Diethylphenylmaleimide, N-2,4-diethylphenylmaleimide, N-2,3-dibutylphenylmaleimide, N-2,4-dibutylphenylmaleimide, N
-2,6-dimethylphenylmaleimide, N-2,3-
Examples thereof include dichlorophenylmaleimide, N-2,4-dichlorophenylmaleimide, N-2,3-dibromophenylmaleimide, and N-2,4-dibromophenylmaleimide, and preferably N-phenylmaleimide.

The method for producing the styrenic copolymer (A) having an imide group of the present invention is produced by continuous bulk or solution polymerization. As the reactor, for example, a plug flow reactor (FPR), a complete mixing type reactor (CST)
R) or a static mixer type plug flow reactor, etc., and one of the above reactors can be used alone or in combination, and is preferably a complete mixing type reactor. Further, only one reactor may be used, or two or three or more reactors may be used at the same time. The styrenic copolymer (A) containing an imide group of the present invention is produced by thermal polymerization or catalytic polymerization by using a polymerization initiator. Examples of the polymerization initiator include an acyl peroxide, an ester peroxide, a ketal peroxide, a carbonate ester peroxide, and an azo compound containing a nitrile group and cyclohexyl. The amount of polymerization initiator added was
It is usually 0.01 to 1.0 part by weight with respect to 00 parts by weight.

[0009] The reaction temperature of the reactor is controlled at 80 to 200 ° C, more preferably within the range of 90 to 160 ° C. Further, the pressure of the reactor is controlled between 1 and 5 kg / cm ² , and the time during which the raw material solution stays in the reactor is 1 to 5 hours. For controlling the molecular weight of the polymer, for example, n
-Dodecyl mercaptan, t-dodecyl mercaptan,
A chain transfer agent such as terpinolene can be used.

The polymerization reaction is carried out until the monomer conversion reaches 40 to 80% by weight, the obtained copolymer solution is heated to 200 to 280 ° C. by a preheater, and the unreacted monomer is degassed. Removes body and volatiles. In general, as the degassing process, volatile components are removed by using a degassing device such as a vacuum degassing tank or an extruder. Then, the volatile matter removed by the condenser is collected and used as a collected liquid, and this collected liquid can be used again as a raw material solution if water is appropriately removed. By extruding the polymer melt from which volatile components have been removed to form particles, a pellet of the styrene-based copolymer (A) containing an imide group of the present invention can be obtained.

In the resin composition of the present invention, the rubber content is 5 to 45% by weight based on the resin composition, and the graft rubber particles are dispersed in the continuous phase in the form of a graft copolymer. Examples of the graft rubber particles include a graft copolymer of emulsified graft rubber particles (B) and a graft copolymer of bulk (or solution) graft rubber particles (C).

The method for producing the emulsified graft rubber particles (B) is as follows. First, 45 to 85 parts by weight (solid content) of a diene rubber latex is added to a styrene monomer 90 to 50 parts by weight.
% By weight and 10 to 50% by weight of an acrylonitrile monomer
And 55 to 15 parts by weight of a monomer mixture comprising 0 to 40% by weight of a monomer copolymerizable therewith, by graft polymerization, emulsified graft rubber particles having a weight average particle size of 0.05 to 0.8 μm (B ) Or latexes of emulsified graft rubber particles (B) having different rubber weight average particle diameters are mixed to produce a latex of emulsified graft rubber particles (B) having a two-peak distribution of particle diameters. The powdery emulsified graft rubber particles (B) are produced through dehydration and drying.
As the diene rubber latex, an unsaturated monomer copolymerizable with 100 to 60% by weight of a conjugated diene monomer is used.
There is a homopolymer composed of 40% by weight or a copolymer thereof. The conjugated diene monomer is represented by the following formula.

[0013]

Embedded image

Here, R is hydrogen, methyl or chlorine.
Styrene-based monomers as copolymerizable unsaturated monomers,
An acrylonitrile-based monomer, a methacrylate-based monomer, an acrylate-based monomer or a mixture thereof is an example.

Representative examples of the diene rubber latex used in the present invention include polybutadiene, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer, and butadiene-methyl methacrylate copolymer. The diene rubber latex has an average particle diameter of 0.05 to 0.8 by directly polymerizing with the monomer.
μm or polymerized to a rubber latex having a small particle size of 0.05 to 0.18 μm, and then further enlarged to a rubber latex of 0.2 to 0.8 μm by a known rubber enlargement method. Good. Examples of the rubber enlargement method include a chemical enlargement method in which an organic acid, a metal salt or a polymer coagulant having a carboxylic acid group is added, a mechanical enlargement method by mechanical stirring, or a freeze enlargement method. . And
As the polymer flocculant used in the chemical enlargement method,
For example, there is a butyl acrylate-methacrylic acid copolymer.

As a method for producing the emulsified graft rubber particles (B), conventional graft polymerization means is commonly used. That is, in the presence of a rubber-like polymer, a styrene-based monomer, an acrylonitrile-based monomer, and if necessary, a mixture comprising a monomer copolymerizable therewith, is graft-polymerized, and from the monomer Can be chemically bonded or grafted to the diene rubber.
At this time, depending on the ratio of the monomer to the diene rubber and the polymerization conditions, the desired graft thickness of the styrene copolymer obtained by grafting to the diene rubber can be obtained. The polymerization temperature involved in the graft polymerization reaction, the type of initiator, the physical or chemical physical properties of the rubber-like polymer (for example, swelling index of rubber, copolymer composition and content of rubber, etc.), particle size, The rate of addition of the monomer, the degree of pre-impregnation of the monomer and the rubber, the amount and type of the chain transfer agent and the emulsifier, etc. are all affected by the thickness of the styrene copolymer grafted to the diene rubber. Influences.

A part of the styrene-based copolymer obtained by polymerization from the emulsion graft polymerization is chemically bonded to a diene-based rubber, and the other part is a free copolymer (free cop).
polymer). When the emulsion-grafted rubber particles (B) are viewed from an electron micrograph, there may be a form in which the styrene-based copolymer is occluded in the rubber particles or a form in which the styrene-based copolymer is not completely occluded. Adjusted according to the requirements of In addition, a part of the styrene-based copolymer is grafted on the surface of the rubber particles, and the styrene-based copolymer in this part has a graft thickness of the emulsified graft rubber particles (B) in the present invention. I understand.

The initiator or catalyst to be added to the graft polymerization reaction is usually 0.01-5.
0 parts by weight, preferably 0.1 to 3.0 parts by weight, the amount of addition is determined by the monomer and the desired polymerization conditions, the initiator is added by gradually increasing the amount , Can greatly contribute to the graft polymerization reaction.

The molecular weight of the graft copolymer is as follows:
The temperature of the graft polymerization reaction and / or the molecular weight can be controlled by adding a regulator. Examples of the molecular weight regulator include mercaptan compounds, halogen compounds, terpene compounds, and the like.
Examples thereof include n-dodecyl mercaptan, tert-dodecyl mercaptan, and α-methylstyrene dimer.

The above-mentioned graft polymerization monomer mixture is continuously or sequentially added to the polymerization system, and more preferably the initiator is continuously or sequentially added. As the initiator, a conventional radical polymerization reaction initiator can be used, for example, a peroxy compound, an azo compound, a sulfate peroxide compound, and the like, and as the peroxylated compound, for example, dicumyl peroxide, tert-butyl peroxide, Suitable are benzoyl peroxide, cumene hydroperoxide, tert-butyl hydroperoxide and the like.

The polymerization reaction between the diene rubber latex and the monomer mixture is carried out at 20 to 100 ° C. in an inert gas atmosphere.
And the pressure is increased to 1 to 8 atm. In order to polymerize the monomer to 90% by the reaction, a polymerization time of usually 2 to 10 hours is required, preferably 3 to 8 hours.

In order to form a graft copolymer of the emulsion-grafted rubber particles (B), a styrene monomer, an acrylonitrile monomer and a monomer copolymerizable therewith are used. Such monomers further include a maleimide-based monomer. Other monomers are the same as the various monomers listed as the styrene-based copolymer (A) containing an imide group.

According to the graft polymerization reaction, emulsified graft rubber particles (B) having a weight average particle size of 0.05 to 0.8 μm.
And the average thickness of the styrene-based copolymer grafted on the emulsified graft rubber particles (B) is 30 to 160 °, preferably the weight average particle size is 0.06 to
0.6 μm, average thickness 40 to 140 °, more preferably average thickness 40 to 100 °. When the average thickness is less than 30 °, the impact strength and fluidity of the resin composition are reduced. On the other hand, when the average thickness is more than 160 °, not only the fluidity of the resin composition is deteriorated, but also the effect on impact strength is reduced. Does not appear. The latex of the emulsified graft rubber particles (B) is coagulated by adding an appropriate amount of a coagulant. Examples of the coagulant include acids such as sulfuric acid and acetic acid, alkaline earth metal salts such as calcium salts such as calcium chloride, magnesium salts such as magnesium sulfate, and aluminum salts such as aluminum sulfate, and preferably alkaline earth metal salts. I do. The coagulated polymer slurry can be removed from water by a dehydration step, and further subjected to a drying treatment to obtain a graft copolymer of powdery emulsified graft rubber particles (B).

In the present invention, the bulk (or solution) graft rubber particles (C) are obtained by polymerizing 5 to 30 parts by weight of a rubbery polymer and a total of 100 parts by weight of the following monomer mixture by a bulk and / or solution polymerization method. Obtained. The monomer mixture contains 90 to 50 parts by weight of a styrene-based monomer, 10 to 50 parts by weight of an acrylonitrile-based monomer, and 0 to 40 parts by weight of a monomer copolymerizable therewith. The conversion of the monomer was set to 40 to 90% by weight, and the copolymer solution was subjected to a degassing step to remove unreacted monomers and volatile components, and to obtain a weight average particle diameter of 0.1%.
Bulk or solution-grafted rubber particles of 1 to 10 μm (C)
Is obtained.

The bulk (or solution) graft rubber particles (C) of the present invention can be continuously reacted using a bulk or solution polymerization reactor. As a reactor,
For example, a plug flow reactor, a complete mixing reactor (CST)
R) or a static mixer-type flow-flow reactor, and the like. One of the above reactors may be used alone or in combination, and a completely mixed reactor is particularly preferred. The number of the reactors may be one alone or two at the same time.
There may be no less than three or more. In producing the massive (or solution) graft rubber particles (C) in the present invention, a polymerization initiator may be added. As the polymerization initiator, acyl peroxide, ester peroxide,
Examples include ketal peroxides, carbonate peroxides, and azo compounds having a nitrile group and a cyclohexyl group. The amount of the polymerization initiator to be added is usually 0.01 to 1.0 part by weight based on 100 parts by weight of the monomer. The reaction temperature in the reactor is 80 to 200 ° C,
Preferably, it is controlled within the range of 90 to 160 ° C. Also,
Preferably, the pressure of the reactor is controlled between 1 and 5 kg / cm ^{2, and} the time during which the raw material solution stays in the reactor is controlled between 1 and 5 hours. In order to control the molecular weight of the polymer, a chain transfer agent such as n-dodecyl mercaptan, t-dodecyl mercaptan, and terpinolene may be used.

After the completion of the reaction of the polymer, the obtained graft copolymer solution is usually cooled to 200 to 280 with a preheater.
Heat to 0 ° C. and remove unreacted monomers and volatiles by degassing. Usually, the degassing process can use a degassing device such as a vacuum degassing tank or an extruder, and the volatiles can be collected by a condenser to obtain a recovered liquid, and the recovered liquid can be reused as a raw material solution. it can. The polymerized hot melt from which volatile components have been removed is extruded into particles, whereby pellets of massive (or solution) rubber particles (C) are obtained.

The rubbery polymer used for the bulk (or solution) graft rubber particles (C) of the present invention includes a conjugated diene rubber,
For example, there are butadiene rubber, isoprene rubber, chlorobutadiene rubber and the like, butadiene rubber is preferred. Butadiene rubbers include types such as high cis (Hi-Cis) and low cis (Low-Cis). The typical composition of cis / vinyl in high cis butadiene rubber is 94-98% / 1-5%, the remaining composition is trans structure, Mooney viscosity is 20-120, molecular weight range is 10
It is preferably from 000 to 800,000. On the other hand, the typical composition of cis / vinyl in low cis butadiene rubber is 2
0 to 40% / 1 to 20%, the remaining composition is a trans structure, and the Mooney viscosity is 20 to 120. Other rubber materials include acrylonitrile / butadiene rubber,
There is a styrene / butadiene rubber. Further, as the type of polymerization in the styrene / butadiene copolymer rubber of the present invention, diblock copolymerization, triblock copolymerization, random copolymerization, star copolymerization and the like are suitable. The styrene /
As for the butadiene copolymer rubber, the weight ratio of styrene / butadiene is preferably from 5/95 to 80/20, and the molecular weight range is preferably from 50,000 to 600,000. As the rubber used in the present invention, preferably, butadiene rubber and styrene / butadiene rubber are suitable, and more preferably, butadiene rubber. Two or more of these rubbers can be used in combination.

In the bulk (or solution) graft rubber particles (C) of the present invention, a part of the styrene-based copolymer obtained by polymerization with the graft monomer is chemically linked to the rubber-like polymer. Some are free copolymers. Also,
The inside of the rubber particles has occluded the styrene copolymer, and the occluded styrene copolymer has a particle size of 0.1.
It is between 01 and 0.3 μm. The number of occluded rubber particles may be one (single occlusion) or plural. On the other hand, some other styrene-based copolymers are grafted on the surface of the rubber particles, and constitute the graft thickness of the bulk (or solution) graft rubber particles (C) in the present invention. The thickness of the graft is determined by the temperature of the graft polymerization reaction, the residence time, the rubber properties (for example, molecular weight, polymerization components, 1,2-vinyl having a microstructure, etc.), the type and amount of the chain transfer agent and the solvent, and the amount of start. It can be adjusted by controlling the type of agent, reactor design, stirring speed, specific operating conditions before and after phase inversion, and the like.

In the present invention, a styrene monomer is used to form the bulk (or solution) graft rubber particles (C).
Acrylonitrile monomers and monomers copolymerizable therewith are used, and the copolymerizable monomers further include maleimide monomers. Other monomers are the same as the various monomers listed as the styrene-based copolymer (A) containing an imide group.

The mass (or solution) of the grafted rubber particles (C) has a weight average particle diameter of 0.1 to 10 μm.
The average thickness of the styrene copolymer grafted on the surface of the rubber particles is 90 to 350 °, preferably 0.2 to 7 μm in weight average particle size, and 100 to 350 ° in average thickness.
If the average graft thickness is less than 90 °, the impact strength of the resin decreases, and if the average graft thickness exceeds 350 °, the fluidity of the resin decreases.

The rubber-modified heat-resistant styrenic resin composition of the present invention comprises an imide group-containing styrenic copolymer (A).
And the emulsified graft rubber particles (B) and the bulk (or solution) graft rubber particles (C) are mixed and extruded. And the emulsified graft rubber particles (B)
Rubber content and massive (or solution) grafted rubber particles (C)
98-70 area% / 2-30 area%
And preferably 97 to 75 area% / 3 to 25 area%
It is. If the ratio of the rubber component in the bulk (or solution) graft rubber particles (C) is lower than 2 area%, the impact strength of the resin is reduced. If it is higher than 30 area%, the tensile strength and heat resistance of the resin are reduced. Is reduced. The method of measuring the area% of the rubber content is as follows: the area (P) of about 1000 rubber particles is determined by electron micrograph, and the area (Q) of the rubber particles having a particle size of 0.2 μm or more is determined. And the particle size is 0.2
The area ratio is defined as Q / P × 100, which is the ratio between the area (Q) of the rubber part having a size of μm or more and the area of the whole rubber part.

In the present invention, the total content of the dimer and trimer of the styrene monomer and / or the acrylonitrile monomer contained in the resin composition is 20,000.
0 ppm and its content is 20,000
When the content is 0 ppm or more, an oily precipitate is likely to be formed on the surface of the mold during molding of the resin (called a plate out phenomenon), so that it is not suitable for a long-time injection molding operation. In the present invention, a dimer and a trimer of a styrene monomer and / or an acrylonitrile monomer are represented by A as a dimer.
S, AAA and SS, and as trimers, AAA, S
SS, A2S, S2A, etc. are the main examples. However, A
Represents an acrylonitrile monomer, and S represents a styrene monomer. The rubber-modified styrenic resin composition according to the present invention is a styrenic copolymer (A) containing an imide group.
And a mixture comprising emulsified graft rubber particles (B) and massive (or solution) graft rubber particles (C). Here, emulsified graft rubber particles (B) and bulk (or solution) graft rubber particles (C)
Is less than 5% by weight of the total resin composition, the impact strength and elongation of the resin are reduced.
If the amount is more than 10% by weight, the fluidity and the uniformity of gloss of the resin will be poor, and the thermal stability will be reduced.

In the present invention, the so-called weight average particle size of the rubber particles is defined as about 200 in a magnified photograph taken with a transmission electron microscope at a magnification of 10,000 after dyeing a thin film made from a resin composition by microtome. -10
The particle size was measured for each of the 00 rubber dispersed particles, and the particle size was determined by the following equation.

[0034]

(Equation 1)

Here, ni indicates the number of rubber particles having a rubber particle diameter of Di.

In the present invention, the average thickness of the styrene-based copolymer grafted on the rubber particles means that the resin composition is first dissolved in acetone, and the soluble matter is removed by centrifugation. The washed gel is washed with acetone, dispersed in acetone to form a dispersion, and then a few drops of the dispersion are dropped on the base of the epoxy resin adhesive, and the base and the gel are thoroughly mixed and dried in vacuo. After removing acetone, a curing agent for an epoxy resin-based adhesive is added, mixed well, and further heated and cured to obtain a specimen in which the gel component is uniformly dispersed in the epoxy resin. Here, the epoxy resin adhesive used was a trade name Araldite rapi.
d (manufactured by Ciba-Geigy).

After the specimen obtained above was stained with osmium tetroxide (OsO ₄ ), a thin film was formed with a microtome, and a photograph was taken using a transmission electron microscope with a magnification of 60,000 times. Stain. However, the rubber portion and the epoxy resin are dyed black, but the graft layer of the styrene copolymer is not dyed and remains white. The outline of the rubber and the graft layer was transferred through tracing paper to 25 or more rubber-dispersed particles taken in the photograph, and each was cut out and weighed, and the area value of the corresponding graft layer was determined from the ratio of each weight. The particle diameter (Di) of the rubber particles and the thickness (ti) of the graft layer can be calculated from the area and the circumference of the rubber particles, and the average thickness is converted by the following equation.

[0038]

(Equation 2)

In the present invention, if necessary, a resin composition having desired properties can be obtained by further adding, for example, a phenol-based or thiopropionate-based antioxidant. An appropriate amount of a lubricant, a light stabilizer, an ultraviolet absorber, a filler, a coloring agent, a plasticizer, an antistatic agent, and the like for improving the physical properties and molding characteristics of the product can also be added. Besides, for example, polycarbonate, polyamide, polyester (PET, PBT),
Polyphenylene ether, acrylonitrile-styrene copolymer, polychloroethylene, polymethyl methacrylate, ethylene-methyl methacrylate copolymer, polypropylene, styrene-butadiene bulk copolymer, hydrogenated acrylonitrile-butadiene copolymer, hydrogenated styrene -A resin for polymer blending such as a butadiene bulk copolymer may also be mixed. Their use amount is usually 5 to 200 parts by weight based on 100 parts by weight of the resin composition of the present invention.

As a mixing method for obtaining the resin composition of the present invention, specifically, after mixing with a commonly used Henschel mixer, mixing is performed using, for example, an extruder, a kneader, or a Banbury mixer. It can be melt-kneaded by a machine.

For the resin composition of the present invention, molding methods such as injection molding, extrusion molding, compression molding, blow molding, and thermoforming, such as vacuum molding, can be applied.

[0042]

Next, the composition of the present invention will be described in more detail based on Examples and physical property measurement data. In Examples, unless otherwise specified, "%" and "part" indicate "% by weight" and "part by weight", respectively.

<Production Example I-1> Preparation of styrene-based copolymer (A-1) containing imide group 68% of styrene, 22% of acrylonitrile, and 10% of N-phenylmaleimide were mixed as raw materials. Further, 0.025% of ethylenebisstearylamide, tertiary dodecylmercaptan, and a recovered liquid obtained by degassing and condensing unreacted volatile components as described later were mixed to form a feed liquid, and the internal temperature was raised to 145 ° C. The retained volume is supplied to a continuous kettle type reactor equipped with a stirrer having a capacity of 45 liters, and the proportion of toluene in the reaction solution is always kept at 15%, and the polymerization rate is kept at 56%.

When volatile components are separated from the reaction solution through a deaerator, a styrene copolymer containing an imide group is obtained. On the other hand, the separated and recovered volatiles are condensed by a condenser to become a recovered liquid, and are further continuously mixed with the raw material mixture and reused. Then, by controlling the addition amount of the third dodecyl mercaptan, a styrene-based copolymer (A-1) containing an imide group having a melt index of 1.0 can be obtained.

<Production Example I-2> Production of styrene-based copolymer (A-2) containing imide group 68% of styrene, 22% of acrylonitrile, and 10% of N-phenylmaleimide were mixed as raw materials. Further, 0.025% of ethylenebisstearylamide, tertiary dodecyl mercaptan, and a recovered liquid obtained by separating and condensing unreacted volatile components generated in the degassing treatment were mixed to form a feed liquid, and the internal temperature was 108 ° C. Is supplied to a continuous kettle type reactor equipped with a stirrer having a volume of 45 liters, so that the ratio of toluene in the reaction solution is always maintained at 15% and the polymerization rate is maintained at 55%.

When the volatile components are separated from the reaction solution through a deaerator, a styrene copolymer containing an imide group is obtained. On the other hand, the recovered volatiles are condensed by a condenser to become a recovered liquid, and are continuously mixed with the raw material mixture and reused. Then, by controlling the amount of the third dodecyl mercaptan used, a styrene-based copolymer (A-2) containing an imide group having a melt index of 0.9 can be obtained.

<Production Example I-3> Preparation of Styrenic Copolymer Containing Imide Group (A-3) 68% of styrene, 22% of acrylonitrile, and 10% of N-phenylmaleimide were mixed as raw materials. Further, 0.025% of ethylenebisstearylamide, tertiary dodecyl mercaptan, and a recovered liquid obtained by separating and condensing the reaction volatiles generated in the degassing treatment were mixed to form a feed liquid, and the internal temperature was 155. The reactor is supplied to a continuous kettle type reactor equipped with a stirrer having a volume of 45 liters and maintained at a temperature of 15 ° C., so that the ratio of toluene in the reaction solution is kept at 15% and the polymerization rate is kept at 57%.

When the volatile components are separated from the reaction solution through a deaerator, a styrene copolymer containing an imide group is obtained. On the other hand, the volatile matter recovered in the above treatment is condensed by a condenser to become a recovered liquid, and is further continuously mixed with the raw material mixture and reused. And the styrene-based copolymer (A-3) containing an imide group having a melt index of 1.3 is obtained by controlling the use amount of the third dodecyl mercaptan.

<Production Example II-1> Production of Emulsified Graft Rubber Particles (B-1) Ingredients Parts by weight 1,3-butadiene 95.0 Acrylonitrile 5.0 Potassium persulfate 15.0 Sodium pyrophosphate 3.0 Oleic acid Potassium 1.5 Distilled water 140.0 Tertiary dodecyl mercaptan 0.2 When the above components are reacted at a reaction temperature of 65 ° C for 12 hours, the conversion is 94%, the solid content is about 40%, and the weight average A synthetic rubber latex having a diameter of 0.1 μm is obtained.

Further, a polymer coagulant having a carboxyl group by the following components is prepared. Ingredients Parts by weight n-butyl acrylate 85 methacrylic acid 15 tertiary dodecyl mercaptan 0.3 potassium oleate 2.0 sodium dioctylsulfosuccinate 1.0 cumene hydroperoxide 0.4 sodium formaldehyde converted sodium sulfate 0.3 distilled water 200 If the above composition is reacted at a reaction temperature of 75 ° C. for 5 hours, a polymer coagulant having a carboxyl group having a conversion rate of 95% and a pH of 6.0 can be obtained.

Next, 100 parts by weight of the synthetic rubber latex (solid content) was enlarged by using 3 parts by weight of the polymer flocculant having a carboxyl group (solid content) to obtain a pH 8.5 and a weight average particle size. An enlarged rubber latex having a diameter of 0.30 μm is prepared. Finally, by using the enlarged rubber latex and performing a graft polymerization reaction according to the following formulation, emulsified graft rubber particles (B-1) can be produced. Ingredients Parts by weight Enlarged rubber latex 100.0 Styrene 25.0 Acrylonitrile 8.3 Potassium oleate 1.2 Tertiary dodecyl mercaptan 0.2 Cumene hydroperoxide 0.5 Ferrous sulfate aqueous solution (0.2%) 0 Formaldehyde-modified sodium hyposulfate aqueous solution (10%) 3.0 Ethylenediaminetetraacetic acid aqueous solution (0.25%) 20.0 Distilled water 200.0 Of the above components, styrene / acrylonitrile was added to the reaction system in a continuous addition system. The graft rubber emulsion is obtained by continuous supply for a period of time to carry out polymerization, which is coagulated with calcium chloride (CaCl ₂ ), and further dewatered and dried to a water content of 2% or less. 0.3 μm
(B-1) (rubber content: 75% by weight).

<Production Example II-2> Production of Emulsified Graft Rubber Particles (B-2) The synthetic rubber latex (rubber weight average particle size 0.1 μm) produced in Production Example II-1 was directly used according to the following formulation. The graft polymerization reaction is performed to produce a non-aggregated graft rubber latex. And calcium chloride (CaC
Coagulation in l ₂ ), dehydration and drying to a water content of 2% or less, to obtain emulsified graft rubber particles having a rubber content of 50%. The weight average particle size of the rubber particles is 0.1 μm.

Component parts by weight Synthetic rubber latex (0.1 μm) (solid content) 100.0 Styrene 75.0 Acrylonitrile 25.0 Potassium oleate 2.0 Tertiary dodecyl mercaptan 0.6 Cumene hydroperoxide 1.4 Sulfuric acid Ferrous aqueous solution (0.2%) 8.6 Formaldehyde-modified sodium hyposulfate aqueous solution (10%) 8.6 Ethylenediaminetetraacetic acid aqueous solution (0.25%) 57.0 Distilled water 200.0 Uncoagulated obtained above Graft rubber latex,
The uncoagulated graft rubber latex obtained in Production Example II-1 is mixed at a weight ratio of 1: 1. further,
The obtained graft rubber graft latex is coagulated with calcium chloride (CaCl ₂ ), dehydrated and dried to a water content of 2% or less to obtain emulsified graft rubber particles (B-
2) (rubber content 63%) is obtained. In this case, the weight average particle diameter of the rubber particles shows a two-peak distribution mode of 0.1 μm and 0.3 μm.

<Production Example II-3> Production of Emulsified Graft Rubber Particles (B-3) The production method was the same as in Production Example II-1, except that
Only the formulation of the graft polymerization reaction is changed as follows.

Ingredients Parts by weight Enlarged rubber latex (solid content) 100.0 Styrene 22.0 Acrylonitrile 8.3 Methyl methacrylate 3.0 Potassium oleate 1.2 Tertiary dodecyl mercaptan 0.2 Cumene hydroperoxide 0. 5 Aqueous ferrous sulfate solution (0.2%) 3.0 Formaldehyde-modified sodium hyposulfate aqueous solution (10%) 3.0 Ethylenediaminetetraacetic acid aqueous solution (0.25%) 20.0 Distilled water 200.0 Prepared by the above formula The obtained graft rubber latex is coagulated with calcium chloride (CaCl ₂ ), and the water content is 2%.
By dehydrating and drying below, emulsified graft rubber particles (B-3) (rubber content 75% by weight) are obtained.
Here, the weight average particle size of the rubber particles is 0.30 μm.

<Production Example II-4> Production of Emulsified Graft Rubber Particles (B-4) The same production method as in Production Example II-1, except that the recipe for the graft polymerization reaction is changed as follows.

Ingredients Parts by weight Enlarged rubber latex (solid content) 100.0 Styrene 8.4 Acrylonitrile 2.8 Potassium oleate 2.0 Tertiary dodecyl mercaptan 0.1 Cumene hydroperoxide 0.2 Ferrous sulfate aqueous solution ( 0.2%) 1.1 Formaldehyde-modified sodium hyposulfate aqueous solution (10%) 1.1 Ethylenediaminetetraacetic acid aqueous solution (0.25%) 7.3 distilled water 200.0 Among the above formulations, styrene / acrylonitrile is 1 The polymerization is carried out by continuously adding to the reaction system for a period of time, and the produced graft rubber latex is coagulated with calcium chloride (CaCl ₂ ), and further dehydrated and dried to a water content of 2% or less to emulsify. Graft rubber particles (B-
4) (Rubber content 90%) is obtained. Here, the weight average particle size of the rubber particles is 0.30 μm.

<Production Example II-5> Production of Emulsified Graft Rubber Particles (B-5) The same production method as in Production Example II-1, except that the recipe for the graft polymerization reaction is changed as follows.

Ingredients Parts by weight Enlarged rubber latex (solid content) 100.0 Styrene 300.0 Acrylonitrile 100.0 Potassium oleate 0.5 Tertiary todecyl mercaptan 2.2 Cumene hydroperoxide 5.4 Ferrous sulfate aqueous solution (0.2%) 32.5 Formaldehyde-modified sodium hyposulfate aqueous solution (10%) 32.5 Ethylenediaminetetraacetic acid aqueous solution (0.25%) 22.0 Distilled water 200.0 Among the above formulations, styrene / acrylonitrile is continuous. The grafted rubber latex is coagulated with calcium chloride (CaCl ₂ ), continuously dehydrated to a water content of 2% or less, and dried to obtain an emulsion graft rubber. Particles (B-5) (rubber content 20%) are obtained. The weight average particle size of the rubber particles at this time is 0.3 μm.

<Production Example III-1> Lump (or solution)
Preparation of Graft Rubber Particles (C-1) Using benzoyl peroxide (0.08 part) as an initiator, 6.6 parts of polybutadiene (Asaden 55AS, manufactured by Asahi Kasei Kogyo Co., Ltd.) and 74.4 parts of styrene,
A feed solution is obtained by completely dissolving 25.6 parts of acrylonitrile and 30 parts of ethylbenzene, and continuously feeding the feed solution from a propeller-type stirrer having a volume of 45 liters and having a cooling circulation pipe inside. The reaction temperature is kept at 100 ° C. and the stirring speed is kept at 150 rpm. When the monomer conversion reaches 15% in the first reactor, the continuously reacted mixture is taken out of the first reactor, and charged into the second, third and fourth reactors in turn. Is added with 0.1 part of tertiary dodecyl mercaptan. Then, a phase inversion phenomenon occurs in the second reactor. The configuration of each of the second, third, and fourth reactors is the same as that of the first reactor.
° C, 110 ° C, 125 ° C, stirring speed 270 rpm, 1
Hold at 50 rpm and 110 rpm. When the conversion of the mixture reaches 60%, the mixture is taken out and put into a deaerator to separate unreacted monomers and volatiles, and then extruded into a massive (or solution) graft rubber pelletized. Particles (C-1) are obtained. The weight average particle size of the rubber particles is 0.95 μm, and the rubber content is 10%.

<Production Example III-2> Lump (or solution)
Production of Graft Rubber Particles (C-2) The same production method as in Production Example III-1, except that 0.12 parts of benzoyl peroxide as an initiator and the conversion of monomers in the first reactor were used. 16%, stirring speed 140r
The reaction temperature of the second skin reactor was changed to 110 ° C. and the stirring speed was changed to 300 rpm, and the product obtained by the reaction was extruded to obtain massive (or solution) graft rubber particles pelletized (C). -2) is obtained. The weight average particle size of the rubber particles at this time is 0.75 μm, and the rubber content is 10% by weight.

<Production Example III-3> Lump (or solution)
Production of Graft Rubber Particles (C-3) The same production method as in Production Example III-1, except that benzoyl peroxide as an initiator was 0.05 parts, and further, tertiary dodecyl mercaptan 0.2 parts The second
To the reactor, the monomer conversion in the first reactor was 19%,
The stirring speed was 270 rpm, and the stirring speed of the second reactor was 25.
At 0 rpm, the phase inversion was changed to occur in the first reactor, and the reaction product was extruded to obtain pelletized bulk (or solution) graft rubber particles (C-3). The weight average particle diameter of the rubber particles is 1.0 μm,
The rubber content is 10%.

<Production Example III-4> Lump (or solution)
Preparation of Graft Rubber Particles (C-4) Using tertiary dodecyl mercaptan and benzoyl peroxide as initiators, 6.6 parts of polybutadiene (made by Asahi Kasei Kogyo Co., Ltd., trade name Asadene 55AS), 74.4 parts of styrene and acrylonitrile 25. A first reactor comprising a propeller-type stirrer having a volume of 45 liters and a cooling circulation pipe inside, which is completely dissolved in 6 parts and 30 parts of ethylbenzene to form a feed solution. , And the reaction temperature is maintained at 95 ° C. and the stirring speed is maintained at 120 rpm. When the monomer conversion in the first reactor reached 14%, the reacted mixture was continuously taken out of the reactor, and charged to the second, third, and fourth reactors in sequence, and the second reactor was charged to the second reactor. 0.08 parts of tri-dodecyl mercaptan are added. The phase inversion occurs in the second reactor. The configuration of the second, third and fourth reactors is the same as that of the first reactor, but the respective reaction temperatures are 105 ° C., 115 ° C., 130 ° C.
° C, stirring speed 200rpm, 150rpm, 110r
pm. Thereby, when the conversion of the mixture reached 60%, the mixture was taken out and put into a deaerator,
The unreacted monomers and volatiles are separated and extruded into massive (or solution) graft rubber particles (C-
4) is obtained. The weight average particle size of the rubber particles is 3.
3 μm, rubber content 10%. The measurement criteria for the physical properties of the resin compositions manufactured from the respective Examples and Comparative Examples in the present invention are as follows.

(1) Melt index (MI): JI
Measured at 220 ° C. × 10 kg according to SK-7210. The unit is represented by g / 10 min.

(2) Izod impact strength (IZOD):
It is measured according to ASTM D-256. Unit is kg
-Expressed in cm / cm.

(3) Method for measuring total content of dimer and trimer in styrene monomer and / or acrylonitrile monomer: dissolving rubber-modified heat-resistant styrene resin composition in acetone and detecting flame ion Chromatography (GC) with Helicopter (FID) (HewlettPack)
Analytical measurement is carried out by ard Co., Ltd., product number 5890 A). (4) Tensile strength: Measured according to ASTM D-638. The unit is expressed in kg / cm ² .

(5) Vicat softening temperature (Vicat S)
offending Temperature): AST
It is measured according to MD-1525. The unit is expressed in ° C. (6) Falling Dart Im
pact, FDI): measured according to ASTM D-3029. The unit is kg / mm.

(7) Plate Out
t): Styrene resin composition was injected at an injection pressure of 1000 kg
/ Cm ² , temperature 250 ° C., mold temperature 50 ° C., using an injection machine (SM-90, manufactured by Seisho Co., Ltd.).
Inject 500 times repeatedly to check if there is any deposit on the mold surface. If there is no oil stain on the mold surface, it is indicated by "◎" .If a little oil stain is on the mold surface, it is indicated by "○" .There is considerable oil stain on the mold surface. In this case, it is indicated by “x”.

Example 1 An imide group-containing styrenic copolymer (A-2) produced in Production Example I-2 64.6
%, 25.4% by weight of the emulsified graft rubber particles (B-1) produced in Production Example II-1, and bulk (or solution) graft rubber particles (C-
1) 10% by weight, and 1.5 parts by weight of a lubricant were further added, and Werner & Pfleiderer ZSK was added.
Extruders 35 are mixed at 240 ° C. to produce extruded pellets to obtain a rubber-modified heat-resistant styrene resin composition having a rubber content of 20% by weight. Then, it is injection molded at 240 ° C. to make a test piece (the injection machine is manufactured by Seio Co., Ltd., number SM
-90). By observing the surface precipitation phenomenon in the mold, the particle distribution of the composition was analyzed, and the sum of a dimer and a trimer containing a styrene monomer / maleimide monomer / acrylonitrile monomer was analyzed. The content was measured and the results are shown in Table 1.

<Example 2> 47.3 imide-containing styrenic copolymer (A-2) produced in Production Example I-2
%, 22.7% by weight of the emulsified graft rubber particles (B-1) produced in Production Example II-1, and bulk (or solution) graft rubber particles (C-
1) 30% by weight as a raw material were mixed uniformly, and the others were measured under the same molding conditions as in Example 1. The results are shown in Table 1.

<Example 3> 56% by weight of the imide group-containing styrenic copolymer (A-1) produced in Production Example I-1 and the emulsified graft rubber particles (B) produced in Production Example II-1 -1) 24% by weight and 20% by weight of the massive (or solution) graft rubber particles (C-1) produced in Production Example III-1 were uniformly mixed as raw materials, and 1.5 parts by weight of a lubricant was further added. , Werner & Pfleiderer Z
A mixture extruded pellet is formed at 240 ° C. using an SK35 extruder to obtain a rubber-modified heat-resistant styrene resin composition having a rubber content of 20% by weight. Then, a specimen was prepared under the same extrusion conditions as in Example 1, and each physical property was measured. The results are shown in Table 1.

<Example 4> The compositions of the combinations shown in Table 1 were mixed uniformly as raw materials, and under the same operating conditions as in Example 1, the emulsified graft rubber particles (B) were converted to (B-2). Change it, make a specimen and measure each physical property,
Table 1 shows the results.

<Example 5> Using the compositions of the combinations shown in Table 1 as raw materials, they were uniformly mixed, and under the same operating conditions as in Example 1, the emulsified graft rubber particles (B) were (B-2)
And the physical properties were measured. The results are shown in Table 1.

<Example 6> The compositions of the combinations shown in Table 1 were mixed uniformly as raw materials under the same operating conditions as in Example 3, except that the emulsified graft rubber particles (B) were (B- In place of 2), a sample was prepared and each physical property was measured. The results are shown in Table 1.

<Example 7> Using the compositions of the combinations shown in Table 1 as raw materials, they were uniformly mixed, and under the same operating conditions as in Example 3, the emulsified graft rubber particles (B) were mixed with (B-
2) The mass (or solution) of the grafted rubber particles (C) was changed to (C-2), a sample was prepared, and each physical property was measured. The results are shown in Table 1.

<Example 8> Using the compositions of the combinations shown in Table 1 as raw materials, they were uniformly mixed, and under the same operating conditions as in Example 3, the emulsified graft rubber particles (B) were (B-3)
, And the physical properties were measured. The results are shown in Table 1.

<Example 9> Using the compositions of the combinations shown in Table 1 as raw materials, they were uniformly mixed, and under the same operating conditions as in Example 3, the emulsified graft rubber particles (B) were mixed with (B-
2) The mass (or solution) of the graft rubber particles (C) was changed to (C-4), this sample was prepared, and each physical property was measured. The results are shown in Table 1.

<Comparative Examples 1 to 7> Each combination of the combinations shown in Table 2 was uniformly mixed as a raw material, and all the physical properties were measured for the test pieces prepared under the same operating conditions as in Example 3. Table 2 shows the results.

[0079]

[Table 1]

[0080]

[Table 2]

Remarks: In the table, SM is a styrene monomer, A
N represents an acrylonitrile-based monomer.

As is clear from the test results of Comparative Examples 1, 4, and 6, the styrene-based copolymer (A-3) containing an imide group was used in the resin composition of the present invention, and the styrene-based monomer was used. When the total content of the di- and / or acrylonitrile-based di- and tri-polymers of the acrylonitrile monomer is 20,000 ppm or more, the fluidity of the resin increases, but the surface precipitation phenomenon on the mold surface is visually observed. Therefore, it is not suitable for long-term work molding, and the softening temperature of the resin is lowered. Further, as shown in the results of Comparative Examples 2 and 3, the average graft thickness of the styrene copolymer grafted onto the emulsified graft rubber particles (B) was less than 30 °, or the mass (or solution) of the graft rubber particles (C If the average graft thickness of the styrenic copolymer grafted to ()) is less than 90 °, the fluidity of the resin is reduced and the impact strength is also deteriorated. According to the results of Comparative Example 4, when the proportion of the rubber in the bulk (or solution) graft rubber particles in the total rubber content is less than 2 area%, the impact strength of the resin is reduced. Then, as can be seen from the test results of Comparative Example 5, the solid (or solution)
When the proportion of the rubber content of the graft rubber particles (C) in the total rubber content is higher than 30 area%, the tensile strength of the resin is deteriorated and the softening temperature is lowered, so that it is not suitable for a wide range of process molding. Similarly, according to Comparative Example 7, when the average graft thickness of the styrene-based copolymer grafted to the emulsified graft rubber particles (B) exceeds 160 °, the fluidity of the resin is poor.

On the other hand, as is apparent from Examples 1 to 9,
When the present invention complies with the above limitations on the components and amounts used, not only imparts properties such as good impact strength, high tensile strength and excellent fluidity to each resin composition, but also provides good heat resistance. Can be maintained, and the precipitation phenomenon on the surface of the mold can be improved.

Claims (3)

[Claims] 1. A rubber-modified heat-resistant styrene resin composition comprising an imide group-containing styrene copolymer (A) and graft rubber particles dispersed in its continuous phase, wherein the imide group contains an imide group. The styrene-based copolymer (A) is a copolymer comprising a styrene-based monomer, an acrylonitrile-based monomer, a maleimide-based monomer and, if necessary, a monomer copolymerizable therewith; Particles
(1) emulsified graft rubber particles (B) having a weight average particle diameter of 0.05 to 0.8 μm, (2) weight average particle diameter of 0.1 to 10 μm
m of the mass (or solution) graft rubber particles (C), and the ratio of the rubber component in the emulsified graft rubber particles (B) to the rubber content in the mass (or solution) graft rubber particles (C) is 98. ~ 70 area% / 2 ~ 30 area%,
The average thickness of the styrene copolymer grafted on the surface of the emulsion graft rubber particles (B) is 30 to 160 °, and the styrene copolymer grafted on the surface of the bulk (or solution) graft rubber particles (C) The average thickness of the copolymer is 9
0 to 350 °, and the composition contains less than 20,000 ppm of a dimer and a trimer composed of a styrene monomer and / or an acrylonitrile monomer,
A rubber-modified heat-resistant styrenic resin composition having a rubber content of 5 to 45% by weight. 2. The emulsified graft rubber particles (B) have a double-peaked rubber particle size distribution, each having a weight average particle size of 0.06.
The weight-average particle diameter of the bulk (or solution) graft rubber particles (C) is from 0.2 to 7 μm, and from 0.17 to 0.6 μm. Rubber-modified heat-resistant styrenic resin composition. 3. The styrene copolymer grafted on the surface of the emulsified graft rubber particles (B) has an average thickness of 40.
The rubber according to claim 1, wherein the average thickness of the styrene-based copolymer grafted on the surface of the bulk (or solution) graft rubber particles (C) is 100 to 300 °. A modified heat-resistant styrenic resin composition.