JP2958059B2 - Thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an N-substituted maleimide resin composition having excellent impact resistance and heat resistance. The present invention relates to an N-substituted maleimide resin composition comprising a polymer.

[Prior art] N-substituted maleimide resins are excellent in heat resistance and rigidity and are expected to be used as new engineering resins, but their use is limited due to poor impact resistance.

As a method for improving the impact resistance of an N-substituted maleimide resin, a method of blending a polybutadiene rubber is disclosed in
-9753. However, in such a method, the unsaturated bond remains in the polybutadiene-based rubber, so that the rubber is unstable at a high temperature, and a material having excellent thermal stability that is practically useful cannot be obtained. Also, a method of compounding an acrylic rubber, that is, a methacrylic acid ester, an aromatic vinyl compound, a vinyl cyanide compound in the presence of an alkyl acrylate rubber, or graft polymerization by adding a further maleimide compound if necessary. Although there is a method in which the gloft copolymer is blended with the N-substituted maleimide resin, the effect of improving the impact resistance is not sufficient.

[Problems to be Solved by the Invention] The present inventors have improved the impact resistance without sacrificing the original excellent heat resistance and mechanical strength of the N-substituted maleimide resin,
As a result of intensive studies on a method for improving the gloss of the molded article, a composite rubber graft obtained by graft-polymerizing a vinyl monomer onto a composite rubber composed of a polyorganosiloxane rubber and a polyalkyl (meth) acrylate rubber is described. By blending the copolymer with the N-substituted maleimide resin, it has excellent impact resistance when formed into a molded product, and also has a gloss,
The present inventors have found that excellent heat resistance and mechanical strength performance can be obtained, and have reached the present invention.

[Means for Solving the Problems] That is, the gist of the present invention is a homopolymer of N-substituted maleimide or a copolymer of a vinyl monomer copolymerizable with N-substituted maleimide and N-substituted maleimide. A certain N-substituted maleimide resin (A), a polyorganosiloxane rubber component of 1 to 99% by weight, and a polyalkyl (meth) acrylate rubber component of 99 to 1% by weight are intertwined with each other so as to be inseparable; and One or more vinyl monomers are graft-polymerized on a composite rubber having an average particle diameter of 0.08 to 0.6 μm in which the total amount of a polyorganosiloxane rubber component and a polyalkyl (meth) acrylate rubber component is 100% by weight. When the total amount of the N-substituted maleimide resin (A) and the composite rubber-based graft copolymer (B) is 100% by weight, -In a thermoplastic resin composition wherein the amount of the substituted maleimide resin (A) is from 40 to 99% by weight.

The N-substituted maleimide resin used in the present invention may be composed of only N-substituted maleimide repeating units, and is a copolymer of a vinyl monomer copolymerizable with N-substituted maleimide and N-substituted maleimide, Is also good.

Specific examples of the N-substituted maleimide used here include N-methylmaleimide, N-ethylmaleimide, and N-methylmaleimide.
N-cycloalkylmaleimide such as n-propylmaleimide, Ni-propylmaleimide, Nn-butylmaleimide, Ni-butylmaleimide, N-tert-butylmaleimide; N-cyclohexylmaleimide; N-arylmaleimides such as N-phenylmaleimide and N-substituted phenylmaleimide; and N-aralkylmalelide. One or more of these can be used as the N-substituted maleimide.

(Wherein, R ¹ , R ² , and R ³ each independently represent a hydrogen atom,
4 represents an alkyl group or halogen. Examples of the vinyl monomer copolymerizable with the N-substituted maleimide include monovinyl aromatic hydrocarbons, monovinylidene aromatic hydrocarbons, (meth) acrylate monomers, unsaturated nitriles, unsaturated acids, and unsaturated acids. Glycidyl compounds having a group can be exemplified. Monovinyl aromatic hydrocarbons include styrene, O-, m- or p-methylstyrene (O-, m- or p-vinyltoluene), 1,3-dimethylstyrene, 2,4-dimethylstyrene, pt- Butylstyrene, O-, m- or p-chlorostyrene, 2,4-
Examples thereof include dibromostyrene, and examples of monovinylidene aromatic hydrocarbons include α-methylstyrene and α-ethylstyrene. Among these monovinyl aromatic hydrocarbons and monovinylidene aromatic hydrocarbons, Styrene, vinyltoluene and α-methylstyrene are preferred, of which α-methylstyrene is more preferred.

(Meth) acrylate monomers include (meth) methyl acrylate, (meth) ethyl acrylate,
N-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate,
I-butyl (meth) acrylate, (meth) acrylic acid
tert-butyl, amyl (meth) acrylate, isoamyl (meth) acrylate, octyl (meth) acrylate,
2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, phenyl (meth) acrylate, and the like can be given. . Examples of unsaturated nitriles include acrylonitrile, methacrylonitrile, α-ethylacrylonitrile, and the like, and examples of unsaturated acids include (meth) acrylic acid, itaconic acid, maleic acid, and fumaric acid. Examples of the glycidyl compound having an unsaturated group include glycidyl (meth) acrylate and allyl glycidyl ether. The above vinyl compounds are used alone or in combination of two or more.

The N-substituted maleimide resin used in the present invention includes N-
A copolymer of at least one type of substituted maleimide and at least one type of the above-mentioned vinyl monomer is preferable in order to maintain a balance between heat resistance and flexibility, and as a copolymer, 1 to 70% by weight of an N-substituted maleimide % Of the vinyl monomer and 99 to 30% by weight of the vinyl monomer, and more preferably 3 to 50% by weight of the N-substituted maleimide. If the N-substituted maleimide is less than 1% by weight, the heat resistance becomes insufficient, which is disadvantageous. If the N-substituted maleimide exceeds 70% by weight, it tends to become brittle, and the application may be limited.

The N-substituted maleimide resin used in the present invention is emulsion polymerization,
It can be produced by a conventionally known method such as suspension polymerization, bulk polymerization, and a method of mechanically mixing monomers.

The composite rubber-based graft copolymer used in the present invention has a structure in which 1 to 99% by weight of a polyorganosiloxane rubber component and 99 to 1% by weight of a polyalkyl (meth) acrylate rubber component are entangled with each other so that they cannot be separated. Wherein the total amount of the polyorganosiloxane rubber component and the polyalkyl (meth) acrylate rubber component is 100% by weight, and the composite rubber having an average particle diameter of 0.08 to 0.6 μm contains one or more vinyl monomers. A product obtained by graft polymerization is used.

Even if one of polyorganosiloxane rubber and polyalkyl (meth) acrylate rubber or a simple mixture thereof is used as a rubber source instead of the above composite rubber, a composition having excellent performance as shown in the present invention can be obtained. To obtain a molded article having excellent impact resistance, mechanical strength and surface gloss only when the polyorganosiloxane rubber component and the polyalkyl (meth) acrylate rubber component are entangled and compounded so that they cannot be separated. Can be.

When a composite rubber containing more than 99% by weight of a polyorganosiloxane component is used, the surface appearance of a molded article from the obtained resin composition deteriorates, and the content of the polyalkyl (meth) acrylate rubber component exceeds 99% by weight. When the resin composition is used, the resulting resin composition has low impact resistance. For this reason, the composite rubber used in the present invention is required to be in the range of 1 to 99% by weight (however, the total amount of both rubber components is 100% by weight) for each of the two rubber components constituting the composite rubber. And the polyorganosiloxane rubber component is 5
Preferably, the content of the polyalkyl (meth) acrylate rubber component is 95 to 20% by weight. The average particle size of the composite rubber needs to be in the range of 0.08 to 0.6 μm. A molded article from the resin composition obtained using an average particle diameter of less than 0.08 μm has low impact resistance, and a molded article obtained from the resin composition obtained using an average particle diameter exceeding 0.6 μm is used. Only those having low impact resistance and poor surface gloss can be obtained. The composite rubber having such an average particle diameter is preferably produced by an emulsion polymerization method. First, a polyorganosiloxane rubber is prepared by an emulsion polymerization method, and then an alkyl (siloxane) is prepared in the presence of the polyorganosiloxane rubber latex. It is preferred that the monomer for synthesizing the meth) acrylate rubber is emulsion-polymerized.

The polyorganosiloxane rubber component constituting the composite rubber can be prepared by emulsion polymerization using the following organosiloxane and a crosslinking agent for a polyorganosiloxane rubber (hereinafter, referred to as a crosslinking agent (I)). A graft crossing agent for rubber (hereinafter referred to as graft crossing agent (I)) can also be used in combination.

As the organosiloxane used here, various cyclic members having three or more member rings can be used, and those having a three to six member ring are preferably used. Examples of 3- to 6-membered organosiloxanes include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, trimethyltriphenylcyclotrisiloxane, and tetramethyltetraphenylcyclotetrasiloxane. And octaphenylcyclotetrasiloxane. These may be used alone or as a mixture of two or more. The amount of the organosiloxane used is at least 60% by weight, preferably at least 70% by weight in the polyorganosiloxane rubber component.

As the crosslinking agent (I), a trifunctional (trialkoxysilane) or tetrafunctional (tetraalkoxysilane) silane compound is used, and trimethoxymethylsilane, triethoxyphenylsilane, tetramethoxysilane, tetraethoxysilane, Examples thereof include tetra-n-propoxysilane and tetrabutoxysilane. Among them, a tetrafunctional silane compound is preferable, and tetraethoxysilane is particularly preferable. The amount of the crosslinking agent (I) used is 0.1 to 30% by weight in the polyorganosiloxane rubber component.

The following formula is used as the graft crossing agent (I). Or ^{_{HS- (CH 2) p -SiR 4}} n O (3-n) / 2 (I-3) ( In the formulas, R ⁴ represents a methyl group, an ethyl group, a propyl group or a phenyl group, R ⁵ is Represents a hydrogen atom or a methyl group; n
Represents 0, 1 or 2, and p represents an integer of 1 to 6).

(Meth) acryloyloxyalkylsiloxane capable of forming a unit represented by the formula (I-1) has a high grafting efficiency and thus can form a graft chain efficiently, and is advantageous in terms of the development of impact resistance. It is. Among (meth) acryloyloxyalkylsiloxanes, methacryloyloxyalkylsiloxanes are preferred, and specific examples thereof are β-methacryloyloxyethyldimethoxymethylsilane, γ-methacryloyloxypropylmethoxydimethylsilane, γ-methacryloyloxypropyldimethoxymethylsilane, and γ-methacryloyloxypropyldimethoxymethylsilane. Examples include methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropylethoxydiethylsilane, γ-methacryloyloxypropyldiethoxymethylsilane, δ-methacryloyloxybutyldiethoxymethylsilane, and the like.
Examples of the vinylsiloxane capable of forming the unit represented by the formula (I-2) include vinylmethyldimethoxysilane and vinyltrimethoxysilane, and a mercaptosiloxane capable of forming the unit represented by the formula (I-3) As γ
-Mercaptopropyldimethoxymethylsilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyldiethoxyethylsilane and the like. The amount of the grafting agent (I) used is 0 to 10% by weight in the polyorganosiloxane rubber component.

In producing the latex of the polyorganosiloxane rubber component, for example, U.S. Pat.
The method described in Japanese Patent No. 3294725 can be used. In the practice of the present invention, a mixture of an organosiloxane, a crosslinking agent (I) and, if desired, a graft-linking agent (I) is mixed with a homogenizer in the presence of a sulfonic acid emulsifier such as alkylbenzenesulfonic acid or alkylsulfonic acid. It is preferable to produce by a method of shear-mixing with water using the method described above. Alkylbenzene sulfonic acid is suitable because it acts as an emulsifier for the organosiloxane and also serves as a polymerization initiator. At this time, it is preferable to use a metal salt of an alkyl benzene sulfonic acid, a metal salt of an alkyl sulfonic acid or the like in combination, since this is effective for stably maintaining the polymer during graft polymerization.

After the polymerization of the organosiloxane, the polymerization is terminated by neutralization with an aqueous alkali solution such as sodium hydroxide, potassium hydroxide or sodium carbonate.

The polyalkyl (meth) acrylate rubber component constituting the composite rubber includes the following alkyl (meth) acrylate, a cross-linking agent for a polyalkyl (meth) acrylate rubber component (hereinafter referred to as a cross-linking agent (II)) and a graft-crosslinking agent ( (Hereinafter referred to as a graft crossing agent (II)). Examples of the alkyl (meth) acrylate include alkyl acrylates such as methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate, and alkyl methacrylates such as hexyl methacrylate, 2-ethylhexyl methacrylate, and n-lauryl methacrylate. Preferably, n-butyl acrylate is preferably used as the alkyl (meth) acrylate.

As the crosslinking agent (II), a polyfunctional (meth) acrylate can be used, and ethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-
Butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate and the like can be exemplified as specific examples.

As the grafting agent (II), compounds having two types of unsaturated groups having different reactivities are used, and examples of such compounds include allyl methacrylate, triallyl cyanurate, triallyl isocyanurate and the like. Among them, allyl methacrylate can also be used as a crosslinking agent. (Even though triallyl cyanurate and triallyl isocyanurate both seem to have the same reactivity of three allyl groups, the reaction when the second and third allyl groups react after the first allyl group reacts Since the reactivity differs from the reactivity when the first allyl group reacts, it can be regarded as having an unsaturated group having a different reactivity.) (In the case of allyl methacrylate, among the two unsaturated groups, The one with lower reactivity also reacts as a cross-linking site by reacting during one part polymerization, and the remaining unsaturated group acts as a graft site at the time of subsequent graft polymerization since it does not react at all during polymerization. These cross-linking agents (II) and graft-crossing agents (II) can be used alone or in combination of two or more.

The amount of each of the crosslinking agent (II) and the grafting agent (II) used in the polyalkyl (meth) acrylate rubber component
0.1 to 10% by weight. When allyl methacrylate is used as the cross-linking agent (II) and the graft cross-linking agent (II), when 0.2 to 20% by weight is used in the polyallyl (meth) acrylate rubber component, other cross-linking agents (II) and graft cross-linking agents (II) are used. Further, it may not be used.

The polymerization of the polyalkyl (meth) acrylate rubber component is carried out by adding the above-mentioned alkyl (meth) acrylate, crosslinking agent (II) and graft crossing agent (II) to a polyorganosiloxane rubber latex. As the polymerization proceeds, the polyalkyl (meth) acrylate rubber component forms a crosslinked network in which the polyorganosiloxane rubber component is entangled with each other. When the graft cross-linking agent (I) is used in the polymerization of the polyorganosiloxane rubber component, the polyorganosiloxane rubber component is used. Grafting of the polyalkyl (meth) acrylate rubber component to the siloxane rubber component also occurs, and in any case, a composite rubber latex in which both rubber components cannot be substantially separated from each other is obtained.

Since the polyorganosiloxane rubber component and the polyalkyl (meth) acrylate rubber component are entangled and crosslinked in this state, the composite rubber cannot be extracted and separated with a normal organic solvent such as acetone or toluene. As the composite rubber used in the present invention, toluene at 90 ° C.
It is preferable that the gel content when extracted and measured over time is 80% or more.

As the composite rubber used in the present invention, the skeleton component derived from the cyclic organosiloxane of the polyorganosiloxane rubber component has a repeating unit of dimethylsiloxane, and the alkyl (meth) acrylate of the polyalkyl (meth) acrylate rubber component is n-butyl. Those which are acrylates are preferred.

The composite rubber thus obtained can be graft-copolymerized with a vinyl monomer.

Examples of a vinyl monomer to be graft-polymerized on the composite rubber include monovinyl aromatic hydrocarbons such as styrene and vinyl toluene; monovinylidene aromatic hydrocarbons such as α-methylstyrene; methacrylic acid such as methyl methacrylate and 2-ethylhexyl methacrylate; Esters: Acrylic esters such as methyl acrylate, ethyl acrylate and butyl acrylate; unsaturated organic acids such as (meth) acrylic acid; epoxy-containing esters such as glycidyl methacrylate; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; These can be used alone or in combination of two or more.

The ratio of the composite rubber and the vinyl monomer in the composite rubber-based graft copolymer (B) is 30 to 95% by weight when the weight of the composite rubber-based graft copolymer (B) is 100%. Preferably, it is 40 to 90% by weight. When the amount of the composite rubber is more than 95% by weight, the dispersion of the composite rubber-based graft copolymer (B) in the resin composition is not sufficient, and when the amount is less than 30% by weight, the impact strength can be exhibited. It is not preferable because it decreases.

The composite rubber-based graft copolymer (B) is obtained by adding the above-mentioned vinyl monomer to a composite rubber latex and subjecting the composite rubber-based graft copolymer latex obtained by one-stage or multi-stage radical polymerization to calcium chloride or magnesium sulfate. It is possible to separate and collect by pouring into a hot water in which a metal salt such as described above is dissolved, salting out and coagulating.

In the resin composition of the present invention, the N-substituted maleimide resin (A) and the composite rubber-based graft copolymer (B) are N-substituted maleimide resin (A) when the total amount of both is 100% by weight. Is preferably 60 to 99% by weight.
If the N-substituted maleimide resin (A) exceeds 99% by weight, the effect of exhibiting impact resistance becomes insufficient, and if it is less than 60% by weight, the mechanical strength tends to decrease, which is not preferable.

The resin composition of the present invention is excellent in heat resistance and impact resistance, particularly at low temperatures, and the level of heat resistance can be increased by appropriately selecting the mixing ratio of the two components (A) and (B). Can be freely designed.

The resin composition of the present invention can be obtained by mechanically mixing the components (A) and (B) using a known device such as a Banbury mixer, a roll mill, or a twin-screw extruder,
This can be appropriately shaped into pellets and used for molding.

Further, a stabilizer, a plasticizer, a lubricant, a flame retardant, a pigment, a filler, and the like can be added to the resin composition of the present invention as needed. Triphenyl phosphite and the like are used as stabilizers, polyethylene wax, polypropylene wax and the like are used as lubricants, and phosphate flame retardants such as triphenyl phosphate and tricresyl phosphate are used as flame retardants, decabromobiphenyl ether and decabromo. Bromine-based flame retardants such as biphenyl, pigments include titanium oxide, zinc sulfide, and zinc oxide, and fillers include glass fiber, asbestos, wollastonite, mica, and talc.

EXAMPLES The present invention will be described in more detail with reference to Examples.

In addition, various physical properties in each Example and Comparative Example were measured according to the following methods.

Flexural strength: according to ASTM D790.

Izod impact strength: ASTM D using 1/4 "notched specimen
Measured according to 256.

Heat distortion temperature: ASTM D 648 18.56 kg / cm ² Load method was followed.

Gloss: According to the method of ASTM D 523-62T (specular gloss at 60 degrees).

Weather resistance: The Izod impact strength retention after 1000 hours was measured in an accelerated exposure test using a weather resistance tester (60 ° C. carbon arc) manufactured by Suga Corporation.

 Further, “parts” in the reference examples indicates “parts by weight”.

Reference Example 1 Production of N-substituted maleimide resin (A-1-3) 200 parts of distilled water was placed in a pressure-resistant polymerization kettle equipped with a stirrer, and a copolymer consisting of methyl methacrylate and 2-sulfoethyl sodium methacrylate 0.1 as dispersants. Parts and 0.5 parts of sodium sulfate, a monomer mixture comprising the various monomers shown in Table 1 in the amounts shown in Table 1, 0.07 parts of n-octylmercaptan, and 0.5 parts of azobisisobutyronitrile After further charging and stirring, nitrogen was bubbled through for 20 minutes to remove oxygen, followed by suspension polymerization at 80 ° C. for 3 hours.
C., kept at that temperature for 15 minutes, and then cooled, filtered, washed with water and dried to form a bead N having an average particle size of about 0.3 mm.
-A substituted maleimide resin (A-1 to 3) was obtained. Table 1 shows the properties of the obtained resin.

Reference Example 2 Production of Composite Rubber Graft Copolymer (S-1) 2 parts of tetraethoxysilane, 0.5 part of γ-methacryloyloxypropyldimethoxymethylsilane and 97.5 parts of octamethylcyclotetrasiloxane were mixed, and 100 parts of a siloxane mixture was mixed. Obtained. To 200 parts of distilled water in which 0.67 part of each of sodium dodecylbenzenesulfonate and dodecylbenzenesulfonic acid were dissolved, 100 parts of the above siloxane mixture was added, and the mixture was preliminarily stirred at 10,000 rpm using a homomixer, and then 300 kg / cm ² using a homogenizer. To obtain an organosiloxane latex. This latex was transferred to a separable flask equipped with a condenser and a stirring blade, and heated at 80 ° C. for 5 hours while stirring and mixing.
The polymerization was allowed to stand at 20 ° C. for 48 hours, and then the polymerization was completed by adjusting the pH of the latex to 7.3 with an aqueous sodium hydroxide solution to obtain a polyorganosiloxane latex (hereinafter referred to as polyorganosiloxane latex-1). The polymerization rate of the obtained polyorganosiloxane rubber is 8
9.7%, and the average particle size of the polyorganosiloxane rubber was 0.23 μm.

117 parts of the above polyorganosiloxane latex-1 was collected and placed in a separable flask equipped with a stirring blade, 57.5 parts of distilled water was added, the atmosphere was replaced with nitrogen, the temperature was raised to 50 ° C., 0.002 parts of ferrous sulfate, ethylenediamine A mixed solution of 0.006 part of disodium tetraacetate, 0.26 part of Rongalit and 5 parts of distilled water was added thereto, and further, 43.95 parts of n-butyl acrylate.
Parts, 1,3-butylene glycol dimethacrylate 0.8 parts,
A mixed solution of 0.25 part of triallyl cyanurate and 0.26 part of tert-butyl hydroperoxide was added to perform radical polymerization. Thereafter, the polymerization was completed by maintaining the internal temperature at 65 ° C. for 1 hour to obtain a composite rubber latex. A part of this latex was collected and the average particle diameter of the composite rubber was measured to be 0.25
μm. The collected latex was dried to obtain a solid, which was extracted with toluene at 90 ° C. for 12 hours and the gel content was measured to be 96.5% by weight. A mixed solution of 0.2 part of tert-butyl hydroperoxide and 20 parts of methyl methacrylate was added dropwise to the composite rubber latex at 65 ° C. over 30 minutes, and then maintained at 70 ° C. for 2 hours to perform graft polymerization on the composite rubber. . The conversion of methyl methacrylate is 9
8.5%. The obtained composite rubber-based graft copolymer latex was dropped into 200 parts of hot water of 1.5% by weight of calcium chloride, coagulated, separated, washed, and dried at 75 ° C. for 16 hours.
97 parts of a dry powder of a composite rubber-based graft copolymer (hereinafter referred to as S-1) was obtained.

Reference Example 3 Production of composite rubber-based graft copolymer (S-2) (example in which graft-crosslinking agent (I) is not used) As a siloxane mixture, a mixture of 2 parts of tetraethoxysilane and 98 parts of octamethylcyclotetrasiloxane was used. PH at the completion of organosiloxane polymerization is 7.1
A polyorganosiloxane latex (hereinafter referred to as polyorganosiloxane latex-2) was obtained in the same manner as in Reference Example 2, except that The polymerization rate of the obtained polyorganosiloxane rubber was 87.6%, and the average particle size of the polyorganosiloxane rubber was 0.23 μm. Reference Example 2 except that this polyorganosiloxane latex-2 was used.
Production of a composite rubber and graft polymerization were carried out in the same manner as described above to obtain a composite rubber-based graft copolymer (S-2).

Reference Example 4 Composite rubber-based graft copolymer (S-3 to
5), Production of polyorganosiloxane rubber-based graft copolymer (S-6) and polybutyl acrylate rubber-based graft copolymer (S-7) Reference Example 2 was repeated except that the components shown in Table 2 were used. Similarly, composite rubber latex (3 to 5) was obtained. Further, the components shown in Table 2 were emulsion-polymerized in the absence of the polyorganosiloxane rubber to obtain a polybutyl acrylate rubber (7).
Table 2 shows the average particle size of the obtained composite rubber and polybutyl acrylate rubber. These composite rubber latexes (3 to 5), polyorganosiloxane latex-1
(Average particle size 0.23 μm) In the same manner as in Reference Example 2 except that (6) and polybutyl acrylate rubber (7) were used, and instead of 0.2 part of tert-butyl hydroperoxide, 0.4 part of cumene hydroperoxide was used. A composite rubber-based graft copolymer (S-3 to 5), a polyorganosiloxane rubber-based graft copolymer (S-6), and a polybutyl acrylate rubber-based graft copolymer (S-7) were obtained.

Examples 1 to 8, Comparative Examples 1 to 5 N-substituted maleimide resins obtained in Reference Example 1 (A-1 to
3) was blended in the combination shown in Table 3 so that each of the composite rubber graft copolymers obtained in Reference Examples 2 to 4 was 85% by weight and the composite rubber-based graft copolymer obtained in Reference Examples 2 to 4 was 15% by weight. These were supplied to a twin-screw extruder (ZSK-30, manufactured by Werner Faudler), melt-kneaded at a cylinder temperature of 250 ° C., and shaped into pellets. After drying the obtained pellets, they are supplied to an injection molding machine (Promat 165/75, manufactured by Sumitomo Heavy Industries, Ltd.), and are injection-molded at a cylinder temperature of 250 ° C and a mold temperature of 60 ° C to obtain various test pieces and obtain physical properties. evaluated. (Examples 1 to
8) In addition, pelletization and injection molding were performed in the same manner except that the N-substituted maleimide resin (A-1 to 3) was used without being compounded with the composite rubber, and the physical properties were evaluated on the obtained test pieces. . (Comparative Examples 1 to 3) Example 1 was repeated except that the polyorganosiloxane rubber-based copolymer (S-6) was used.
A test piece was obtained in the same manner as described above, and the physical properties were evaluated. (Comparative Example 4) Furthermore, the N-substituted maleimide resin (A
-2) was 85% by weight, and the graft copolymer S obtained in Reference Example 4 was used.
-6 and S-7 were each blended at 7.5% by weight to prepare a resin composition, and Examples 1 to 8 were used except that this was used.
The physical properties were evaluated in the same manner as described above. (Comparative Example 5) Table 3 shows the results.

From these Examples and Comparative Examples, it is understood that the resin composition of the present invention is excellent in impact resistance and surface gloss.

That is, from the comparison of Examples 1, 3, and 8, A-1 to A-
3 using any N-substituted maleimide resin It can be seen that the impact resistance was improved, the bending strength and the heat deformation temperature were maintained, and the gloss was also maintained at an excellent level. Further, it can be seen from Examples 3 to 7 that the ratio of both rubber components of the composite rubber composed of polyorganosiloxane rubber and polybutyl acrylate rubber is effective in a wide range. However, Comparative Example 4
As shown in (1), when a graft copolymer obtained by using a polyorganosiloxane rubber instead of a composite rubber was used (Comparative Example 4), a polyorganosiloxane rubber-based graft copolymer and a polybutyl acrylate rubber-based graft copolymer were used. It can be seen that when the polymer was simply blended and not formed into a composite rubber (Comparative Example 5), the impact resistance was not sufficiently improved, and the gloss was significantly reduced.

Examples 9 to 12, Comparative Example 6 The N-substituted maleimide resin A-2 obtained in Reference Example 1 and the composite rubber-based graft copolymer S-1 obtained in Reference Example 2 were blended at various ratios, and the resin composition was changed. I got something. (Examples 9 to 12) On the other hand, MBS resin (a resin obtained by graft copolymerization of butadiene rubber with methyl methacrylate / styrene and having a butadiene rubber content of 60% by weight and a polymerization ratio of methyl methacrylate / styrene of 25/15) and the above The N-substituted maleimide resin A-2 was blended at the blending ratio shown in Table 4. (Comparative Example 5) A test piece was prepared in the same manner as in Example 1 except that these compounds were used, and the impact resistance and the weather resistance were examined. Table 4 shows the results.

As is evident from Table 4, when the compounding ratio of the composite rubber-based graft copolymer increases, the impact resistance improves. It is shown that those using MBS resin instead of the composite rubber-based graft copolymer are inferior in both impact resistance and weather resistance to those of the present invention.

[Effect of the Invention] One or more kinds of composite rubbers having a structure in which the N-substituted maleimide resin (A), the polyorganosiloxane rubber component and the polyalkyl (meth) acrylate rubber component of the present invention are entangled with each other so as not to be separable. A thermoplastic resin composition comprising a composite rubber-based graft copolymer (B) obtained by graft-polymerizing a vinyl-based monomer is a molding excellent in impact resistance, heat resistance, mechanical strength, weather resistance and surface gloss. It has an excellent effect of giving products.

Additional Notes Preferred embodiments of the present invention are described below.

1) An N-substituted maleimide resin (A) is a copolymer of at least one N-substituted maleimide in an amount of 1 to 70% by weight and at least one vinyl monomer copolymerizable with the N-substituted maleimide in an amount of 99 to 30% by weight. The thermoplastic resin composition according to claim 1, which is a polymer.

2) The above-mentioned embodiment 1, wherein the N-substituted maleimide is at least one member selected from the group consisting of N-alkylmaleimide, N-phenylmaleimide having an alkyl group having 1 to 8 carbon atoms, and N-phenylmaleimide. Thermoplastic resin composition.

(Wherein, R ¹ , R ² , and R ³ each independently represent a hydrogen atom,
4 represents an alkyl group or halogen. 3) The thermoplastic resin composition according to the above item 1, wherein the vinyl monomer copolymerizable with the N-substituted maleimide is at least one selected from styrene, α-methylstyrene, vinyltoluene and methyl methacrylate. .

4) The thermoplastic resin composition according to claim 1, wherein the polyorganosiloxane rubber component of the composite rubber is prepared by emulsion polymerization using a cyclic organosiloxane and a crosslinking agent for a polyorganosiloxane rubber.

5) The polyorganosiloxane rubber component of the composite rubber is prepared by emulsion polymerization using a cyclic organosiloxane, a cross-linking agent for polyorganosiloxane rubber, and a graft cross-linking agent for polyorganosiloxane rubber.
The thermoplastic resin composition according to the above.

6) A polyalkyl (meth) acrylate rubber component is prepared by using an alkyl (meth) acrylate, a crosslinking agent for polyalkyl (meth) acrylate rubber, and a grafting agent for polyalkyl (meth) acrylate rubber in the presence of a polyorganosiloxane rubber. The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition is obtained by emulsion polymerization.

7) The polyorganosiloxane rubber component, wherein the skeleton derived from the cyclic organosiloxane has a repeating unit of dimethylsiloxane, and the polyalkyl (meth)
6. The thermoplastic resin composition according to claim 4, wherein the alkyl (meth) acrylate of the acrylate rubber component is n-butyl acrylate.

Continuation of the front page (56) References JP-A-63-135441 (JP, A) JP-A-2-209951 (JP, A) JP-A-2-191661 (JP, A) (58) Fields studied (Int .Cl. ⁶ , DB name) C08L 35/00-35/08 C08L 51/04-51/08

Claims (1)

(57) [Claims] 1. A homopolymer of N-substituted maleimide or N-substituted maleimide
-N-substituted maleimide resin (A) which is a copolymer of a vinyl monomer copolymerizable with substituted maleimide and N-substituted maleimide, 1 to 99% by weight of polyorganosiloxane rubber component, and polyalkyl (meth) acrylate Rubber component 99-1
% By weight of a polyorganosiloxane rubber component and a polyalkyl (meth) acrylate rubber component having an average particle size of 0.08 to 0.6 μm. A composite rubber-based graft copolymer (B) obtained by graft-polymerizing one or more vinyl monomers onto a composite rubber, and an N-substituted maleimide resin (A) and a composite rubber-based graft copolymer ( A thermoplastic resin composition wherein the amount of the N-substituted maleimide resin (A) is 40 to 99% by weight when the total amount of B) is 100% by weight.