JPH0952958A - Molding for resin molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin molded product good in molding efficiency and excellent in heat resistance, chemical resistance and surface appearance. SOLUTION: First, a resin composition comprising (A) 99-1wt.% of a syndiotactic styrene-based polymer and (B) 1-99wt.% of at least one kind of thermoplastic resin or elastomer having a part or the whole of the molecular chain composed of segments compatible with the noncrystalline phase portion of the component A is melted at 270-370 deg.C. Subsequently, the resultant composition is molded by using a mold covered with a thermal insulation material having <=0.01cal/cm.s. deg.C thermal conductivity at 20 deg.C and a molding cavity with its wall temperature set at 20-150 deg.C.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for molding a resin molded product. More specifically, efficiently,
The present invention relates to a molding method for obtaining a resin molded product having excellent heat resistance, chemical resistance and surface appearance.

[0002]

2. Description of the Related Art A styrene-based polymer conventionally produced by a radical polymerization method has a defect that it is an amorphous resin because of its atactic three-dimensional structure, and is inferior in heat resistance and chemical resistance. In order to overcome this drawback, a styrene-based polymer having a syndiotactic regularity in three-dimensional structure has been developed, and a composition in which other components have been added to the styrene-based polymer has been proposed (JP-A-62-62). -1048
18 gazette, the same 62-257948 gazette, the same 62-2.
57950).

Further, a composition containing two or more other components has been proposed for the purpose of improving not only heat resistance and chemical resistance but also mechanical properties such as impact resistance and rigidity. (Japanese Patent Laid-Open No. 1-182344, 1)
-182350 gazette and the same 2-64140 gazette). This syndiotactic styrene resin composition has characteristics that it is superior in heat resistance, chemical resistance, etc. as compared with the atactic styrene resin composition, but these characteristics are sufficient for syndiotactic styrene resin. It is only manifested after crystallization, and if the crystallization is not sufficient, or the molded product solidified in the amorphous state has heat resistance,
The chemical resistance is impaired. Since the glass transition temperature (Tg) of the syndiotactic styrene-based resin is about 100 ° C., a high molding temperature and a long cooling time are required to crystallize the syndiotactic styrene-based resin at the time of molding. There is a problem that the molding efficiency is lower than that of the molding of the tick styrene resin or its composition. Conversely, if the molding temperature is lowered or the molding time is shortened to achieve molding efficiency equivalent to that of molding of atactic styrenic resin or its composition, crystallization of the molded article becomes insufficient and This results in deterioration of heat resistance and chemical resistance. Further, the composition comprises a syndiotactic styrene resin and one or more thermoplastic resins or elastomers having a segment in which all or part of the molecular chain is compatible with the amorphous phase portion of the syndiotactic styrene resin. In this case, since this thermoplastic resin inhibits the crystallization of the syndiotactic styrene resin, the molding efficiency is significantly affected.

In order to solve this problem and obtain a molded article having excellent characteristics, a composition obtained by blending a syndiotactic styrene resin with an inorganic compound (JP-A-1-108244) and a syndiotactic styrene resin are used. Composition containing metal salt of ionic hydrocarbon copolymer
No. 182347), a composition in which a crystal nucleating agent is blended with a syndiotactic styrene resin (JP-A 1-20).
1350), a composition in which a crystal nucleating agent and a crystallization accelerator are mixed with a syndiotactic styrene resin (JP-A-2-202939), and the like are proposed. However, even with these techniques, there is still room for improvement in that the crystallization of the molded product obtained without lowering the molding efficiency is still insufficient and the appearance of the molded product is rather poor. Furthermore, the composition described above comprises one or more thermoplastic resins or elastomers having a syndiotactic styrene resin and a segment in which all or part of the molecular chain is compatible with the amorphous phase portion of the syndiotactic styrene resin. If so, there is little improvement.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to propose a molding method for obtaining a resin molded product which is excellent in heat resistance, chemical resistance and surface appearance with high efficiency at a low molding temperature.

[0006]

That is, the present invention is as follows.
(A) 99 to 1% by weight of a styrenic polymer having syndiotactic stereoregularity, and (B) a segment in which all or part of the molecular chain is compatible with the amorphous phase portion of the component (A). A resin composition comprising 1 to 99% by weight of one or more thermoplastic resins or elastomers 270
Melts to 370 ° C. and has a thermal conductivity of 0.0 at 20 ° C.
Molding of a resin molded product, characterized in that the wall temperature of a mold cavity covered with a heat insulating material of 1 cal / cm · sec · ° C. or less is 20 to 150 ° C. and molding is performed using a mold having the mold cavity. Is the way.

The styrene-based polymer having syndiotactic stereoregularity (hereinafter referred to as syndiotactic styrene-based resin) used in the present invention has a phenyl group or a phenyl group with respect to the main chain formed from carbon-carbon bonds. It has a steric structure in which substituted phenyl groups are alternately positioned in opposite directions, and its tacticity is quantified by a nuclear magnetic resonance method ( ¹³ C-NMR method) using isotope carbon.
Tacticity measured by ¹³ C-NMR method is
The existence ratio of a plurality of continuous structural units can be indicated by, for example, a diad when 2 units, a triad when 3 units, and a pentad when 5 units.

The syndiotactic styrene resin used in the present invention is preferably 50% or more, more preferably 80% or more, and particularly preferably 90% or more syndiotacticity in racemic pentad. The syndiotactic styrene resin used in the present invention has the following general formula (I).

[0009]

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(In the formula, R represents a hydrogen atom, a halogen atom or a substituent containing at least one of carbon atom, oxygen atom, nitrogen atom, sulfur atom, phosphorus atom, selenium atom, silicon atom and tin atom. , M is an integer of 1 to 3. However, when m is a plurality, each R may be the same or different. It is a combined hydrogenated polymer.

Preferred aromatic vinyl compounds used herein are styrene, α-methylstyrene, methylstyrene, ethylstyrene, isopropylstyrene, tert-butylstyrene, phenylstyrene, vinylstyrene, chlorostyrene, bromostyrene, fluoro. Styrene, chloromethylstyrene, methoxystyrene,
There are ethoxystyrene and the like, which are used alone or in combination of two or more. Among these, more preferred aromatic vinyl compounds include styrene, p-methylstyrene,
m-methylstyrene, p-tert-butylstyrene, p-chlorostyrene, m-chlorostyrene and p-fluorostyrene.

The syndiotactic styrene resin is not particularly limited in its molecular weight, but in general,
Weight average molecular weight of 10,000 or more, preferably 50,
It is more than 000. Here, the weight average molecular weight is 10,0.
If it is less than 00, the thermal properties and mechanical properties of the obtained molded article are deteriorated, which is not preferable. Furthermore, the molecular weight distribution is not limited to a wide or narrow range, and various kinds can be applied. Such a syndiotactic styrene-based resin can be produced, for example, with reference to the technique disclosed in JP-A-63-268709. That is, in an inert hydrocarbon solvent or in the absence of a solvent,
It can be produced by polymerizing a styrene-based monomer using a titanium compound and alumoxane, which is a condensation compound of water and trialkylaluminum, as a catalyst.

The syndiotactic styrene resin may be modified with a modifier having a polar group. Examples of the polar group include acid hydride, carbonyl group, acid anhydride, acid amide, carboxylic acid ester, acid azide, sulfone group, nitrile group, cyano group,
Isocyanic acid ester, amino group, hydroxyl group, imide group,
Examples thereof include a thiol group, an oxazoline group and an epoxy group. Particularly preferred are acid anhydrides and epoxy groups, and maleic anhydride groups are preferred among the acid anhydrides.

The component (B) used in the present invention is one or more kinds of thermoplastic resins or elastomers each of which has a segment in which all or part of the molecular chain is compatible with the amorphous phase portion of the component (A). Preferable examples thereof include a styrene polymer having an atactic three-dimensional structure, a styrene polymer having an isotactic three-dimensional structure, and acrylonitrile-
Styrene-based polymers such as styrene copolymer (AS resin) and acrylonitrile-butadiene-styrene-copolymer (ABS resin), polyphenylene ether-based polymer, styrene in which a part or all of the butadiene part is hydrogenated-
Butadiene block copolymer elastomer (SEB
S), styrene-butadiene copolymer elastomer (SB
R), acrylonitrile-butadiene-styrene copolymer elastomer (ABS rubber), acrylonitrile-alkyl acrylate-butadiene-styrene copolymer elastomer (AABS rubber), methyl methacrylate-alkyl acrylate-styrene copolymer elastomer (MAS rubber) Styrene-based elastomers such as methyl methacrylate-alkyl acrylate-butadiene-styrene copolymer elastomer (MABS rubber) and the like, and these thermoplastic resins are composed of one kind or a combination of two or more kinds. Further, these thermoplastic resins may be modified with a modifier having a polar group. Furthermore, among these thermoplastic resins, a styrene polymer having an atactic three-dimensional structure, a polyphenylene ether polymer, and a styrene-butadiene block copolymer elastomer (SEBS) in which some or all of the butadiene moieties are hydrogenated One type or a combination of two or more types is preferable.

Styrene-based polymers having an atactic three-dimensional structure (hereinafter referred to as atactic styrene-based resins) are solution-polymerized, bulk-polymerized, suspension-polymerized, bulk-polymerized in the presence or absence of a rubber-like polymer. Obtained by a polymerization method such as suspension polymerization. A polymer comprising one or more aromatic vinyl compounds represented by the general formula (I), or a copolymer of one or more other vinyl monomers copolymerizable with one or more aromatic vinyl compounds. , Hydrogenated polymers thereof, and mixtures thereof.

As the aromatic vinyl compound used here, styrene, α-methylstyrene, methylstyrene, ethylstyrene, isopropylstyrene, tert-butylstyrene, phenylstyrene, vinylstyrene, chlorostyrene, bromostyrene, fluorostyrene. , Chloromethylstyrene, methoxystyrene, ethoxystyrene, etc., preferably styrene, p-methylstyrene, m-methylstyrene, p-tert-butylstyrene, p-chlorostyrene, m-chlorostyrene, p-fluorostyrene. There may be one type or a combination of two or more types.

Other copolymerizable vinyl monomers include:
Vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, methyl acrylate, ethyl acrylate,
Propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, dodecyl acrylate, octadecyl acrylate, phenyl acrylate, alkyl acrylates such as benzyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, Amyl methacrylate, hexyl methacrylate,
Octyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, phenyl methacrylate, methacrylic acid alkyl esters such as benzyl methacrylate, maleimide, N-methylmaleimide, N-ethylmaleimide, N-butylmaleimide, N
Maleimide compounds such as -laurylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide and N- (p-bromophenyl) maleimide;

As the rubbery polymer, polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, diene rubber such as polyisoprene, ethylene-α-olefin copolymer, ethylene-
α-olefin-polyene copolymer, non-diene rubber such as polyacrylic acid ester, styrene-butadiene block copolymer, hydrogenated styrene-butadiene block copolymer, ethylene-propylene elastomer, styrene-grafted ethylene-propylene elastomer, Examples thereof include ethylene ionomer resins and hydrogenated styrene-isoprene block copolymers.

The atactic styrenic resin has a weight average molecular weight of 10,000 or more, preferably 50,000.
00 or more. When the weight average molecular weight is less than 10,000, the thermal properties and mechanical properties of the obtained molded product are deteriorated, which is not preferable. As the polyphenylene ether-based polymer, the following general formula (II-a) or (II-
b),

[0020]

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[0021]

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(Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ ,
R ₆ is a monovalent residue such as an alkyl group having 1 to 4 carbon atoms, an aryl group, halogen, or hydrogen, and R ₅ and R ₆ are not hydrogen at the same time) as a repeating unit, and the structural unit has the general formula (II A homopolymer or copolymer of (a) or (II-b) can be used. As a typical example of a homopolymer of a polyphenylene ether-based polymer, poly (2,6-dimethyl-1,4-phenylene) ether,
Poly (2-methyl-6-ethyl 1,4-phenylene) ether, poly (2,6-diethyl-1,4-phenylene) ether, poly (2-ethyl-6-n-propyl)-
1,4-phenylene) ether, poly (2,6-di-n
-Propyl-1,4-phenylene) ether, poly (2
-Methyl-6-n-butyl-1,4-phenylene) ether, poly (2-ethyl-6-isopropyl-1,4-)
Phenylene) ether, poly (2-methyl-6-chloroethyl-1,4-phenylene) ether, poly (2-methyl-6-hydroxyethyl-1,4-phenylene) ether, poly (2-methyl-6-chloroethyl) -1,4
And homopolymers such as phenylene) ether.

Examples of polyphenylene ether copolymers include copolymers of 2,6-dimethylphenol and 2,3,6-trimethylphenol, copolymers of o-cresol, and 2,3,6-trimethyl. It includes a polyphenylene ether copolymer mainly composed of a polyphenylene ether structure, such as a copolymer of phenol and o-cresol.

Further, in the polyphenylene ether-based polymer, various other phenylene ether units which have been conventionally proposed to be allowed to be present in the polyphenylene ether-based polymer may be used unless they are contrary to the gist of the present invention. It may be included as a partial structure. As an example of what is proposed to coexist in a small amount, Japanese Patent Application No. 63-1269
2- (dialkylaminomethyl) -6-methylphenylene ether unit and 2- (N-alkyl-N-phenylaminomethyl) -6-, which are described in JP-A No. 8 and JP-A-63-301222. Examples thereof include a methylphenylene ether unit. Further, a polyphenylene ether-based polymer in which a small amount of diphenoquinone or the like is bound in the main chain is also included. Furthermore, for example, Japanese Patent Laid-Open No. 2-2
76823, JP-A-63-108059,
It also includes polyphenylene ether modified with a compound having a carbon-carbon double bond, as described in JP-A-59-59724. The number average molecular weight of the polyphenylene ether-based polymer is 1,000 to 1
The range of 0,000 is preferable, and the more preferable range is 6,000 to 60,000.

The styrene elastomer is preferably a block copolymer of a styrene compound and a conjugated diene, and the general formula of these block copolymers is (A
-B) _{n + 1} , or A- (BA) _n , or B- (A
-B) The _one represented by _{n + 1} is optimal. (However, in the formula, A is a polymer block composed of a styrene compound, B is a conjugated diene polymer block, n is an integer of 1 to 20, and the proportion of the A block in the whole molecule is 1 to 50% by weight. The average molecular weight of these copolymers is 10,
000 to 1,000,000, preferably 30,000
~ 500,000. Specific examples of these styrene-based elastomers include styrene-butadiene random copolymers, styrene-isoprene random copolymers, styrene-butadiene-styrene triblock copolymers, styrene-isoprene-styrene triblock copolymers,
Polystyrene block-terminated styrene-isoprene radial block copolymers, styrene-butadiene multiblock copolymers, styrene-isoprene multiblock copolymers and other styrene-conjugated diene block copolymers, and hydrogenated production of these The thing etc. can be mentioned.

It may be modified with a modifier having a polar group.
As the polar group, acid hydride, carbonyl group, acid anhydride, acid amide, carboxylic acid ester, acid azide, sulfone group, nitrile group, cyano group, isocyanic acid ester, amino group, hydroxyl group, imide group, thiol group, oxazoline Group, an epoxy group, etc. are mentioned, An acid anhydride and an epoxy group are preferable, and a maleic anhydride group is preferable in an acid anhydride.

The blending amounts of the components (A) and (B) of the composition used in the present invention are determined in consideration of heat resistance, chemical resistance, impact resistance and the like of the molded article obtained by the molding method of the present invention. , The following relationships must be met: The compounding amount of the component (A) is 99 to 1% by weight, preferably 90 to 10% by weight, more preferably 80 to 20% by weight. If the blending amount exceeds 99% by weight, the mechanical properties are not sufficiently improved, and if it is less than 1% by weight, heat resistance and chemical resistance are poor.

The blending amount of the component (B) is 1 to 99% by weight,
Preferably 10-90% by weight, more preferably 20-
80% by weight. If the blending amount is less than 1% by weight, the improvement of mechanical properties is insufficient, and if it exceeds 99% by weight, heat resistance,
Poor chemical resistance. The composition used in the present invention is (A)
And component (B) can be obtained by melt-kneading. A single-screw extruder, a twin-screw extruder, etc. can be used for melt-kneading. A twin-screw extruder with a vent is preferable. The melt-kneading temperature is in the range of 270 to 370 ° C., preferably 280
It is in the range of up to 330 ° C. If the melt-kneading temperature is lower than 270 ° C., the melting of the raw materials will be insufficient and a uniform composition cannot be obtained. When the melt-kneading temperature is higher than 370 ° C., the raw materials are decomposed, which is not preferable.

A resin molded article obtained by the molding method of the present invention is obtained by heating and melting the above composition in the range of 270 to 370 ° C., preferably 280 to 330 ° C.
It is obtained by molding at a mold temperature of 0 ° C, preferably 30 to 145 ° C, more preferably 40 to 140 ° C. When the heating and melting temperature is lower than 270 ° C., the composition is not sufficiently melted, so that a molded product having uniform physical properties cannot be obtained. When the heating and melting temperature is higher than 370 ° C., decomposition of the composition occurs, which is not preferable. Mold temperature is 150
If the temperature exceeds ℃, the crystallization of the syndiotactic styrene resin can be sufficiently promoted, but it is necessary to lengthen the cooling time or the mold releasability of the molded product is deteriorated. If the mold temperature is lower than 20 ° C, the syndiotactic styrene resin can no longer be crystallized.
In addition, various molding methods used for molding conventional atactic styrene resin, specifically, injection molding, blow molding, press molding, extrusion molding, vacuum molding, injection molding,
Cast molding or the like is used. Among these, injection molding, blow molding, and press molding are particularly preferable.

The heat conductivity of the heat insulating material used in the present invention is 0.01 cal / cm · sec · ° C or less, preferably 0.005 cal / cm · sec · ° C or less. If the thermal conductivity is higher than 0.01 cal / cm · sec · ° C, the mold temperature needs to be 150 ° C or higher in order to sufficiently promote the crystallization of the syndiotactic styrene resin, so that the molding cycle is long. In addition, the releasability of the molded product deteriorates. However, examples of the heat insulating material used in the present invention include resins and ceramics. Especially,
Resin has a thermal conductivity of 0.002 cal / cm · sec · ° C
The following is preferable because the heat insulating effect is large. Further, among the resins, polyimide is particularly preferable in terms of thermal conductivity and durability. Since the thermal conductivity of ceramics is slightly higher than that of resin, the coating layer must be made somewhat thicker in order to exhibit the same heat insulating effect as resin.

In addition to the above requirements, the heat insulating material for covering the mold of the present invention has excellent heat resistance, resistance to cold and heat cycles, excellent wear resistance, and good adhesion to the mold body. It is desirable that the mold body be well coated and have properties such as surface polishing. In addition, the coating thickness of the heat insulating material is preferably a thin layer which is substantially on the outermost surface layer of the mold, which can suppress an increase in cooling time. The preferable coating thickness of the heat insulating material for sufficiently promoting crystallization and not impairing the molding efficiency varies depending on the molding conditions such as the thermal conductivity of the heat insulating material used, the melting temperature during molding, and the mold temperature. Therefore, it is preferable to make the determination in consideration of these conditions and the molding cycle.

The use of polyimide as a heat insulating material is particularly convenient when coating a mold surface having a complicated shape used in injection molding, blow molding and the like. The heat insulating material used in the present invention is preferably firmly adhered to the mold surface so as to withstand repeated molding many times,
For that purpose, it is desirable to coat the surface of the mold with a film having good durability and being in close contact with the mold. In order to coat a complex mold surface with polyimide and firmly adhere it, a polyamic acid, which is a precursor of polyimide, is dissolved in a solvent such as N-methylpyrrolidone and applied on the mold surface, and then heated to form polyimide. It can be preferably carried out depending on the method of formation.
Since the polymer of the polyimide precursor is a polar group such as a carboxyl group, it has good adhesion to the mold, and a polyimide thin layer adhered to the mold surface can be obtained by reacting and forming polyimide on the mold surface.

In the process of supplying the heat-plasticized resin or resin composition into the mold and cooling under pressure to obtain a molded body, the temperature of the mold surface reaches 100 ° C. for each molding. Differential heating and cooling is repeated. Generally, the thermal expansion coefficient of the heat insulating material and that of the metal are significantly different from each other, so that severe stress is generated at the interface between the metal and the heat insulating material. As a heat insulating material capable of withstanding this stress for tens of thousands of times, it is required that both the breaking strength and the breaking elongation are large, and the adhesive force with the metal is large, and polyimide is convenient because it satisfies these requirements. Of these, a tough linear high-molecular-weight polyimide containing no substance that inhibits adhesion with a metal such as fluorine is most preferable.

In order to obtain heat resistance, it is preferable that the polyimide used has a high glass transition temperature (Tg). The Tg of the straight-chain polyimide varies depending on the constituents.
g is preferably 200 ° C. or higher, more preferably 230
C. or higher, most preferably 270.degree. C. or higher. The smaller the thermal conductivity of the polyimide is, the more preferable it is, but the one having the thermal conductivity of 0.002 cal / cm · sec · ° C. or less can be particularly preferably used.

The thickness of the polyimide layer is 0.01-2 mm
It is properly selected within the range. If the thickness is less than 0.01 mm, it is necessary to raise the mold temperature in order to obtain a molded product that has been sufficiently crystallized, and the molding efficiency is reduced. On the contrary, when the mold temperature is lowered, the molding efficiency is increased but the crystallization is insufficient.
If it exceeds 2 mm, the cooling effect is lowered and the molding efficiency is lowered. Furthermore, the preferable thickness of the polyimide layer varies depending on the molding method. In the case of injection molding, 0.01-
A thickness of 0.5 mm is preferable, and 0.0 is more preferable.
It has a thickness of 3 to 0.2 mm. In the case of blow molding or press molding, a thickness of 0.1 to 1 mm is preferable.

The "polyimide thickness" means its maximum thickness. Further, the linear high molecular weight polyimide used in the present invention preferably has a high strength and elongation, and particularly, a high elongation at break is convenient for a cold-heat cycle, and the required elongation at break is 10%. Or more, preferably 20% or more. Break elongation is measured by ASTM D
According to 638.

As a preferred example of the high molecular weight polyimide which can be used in the present invention, Kapton (trade name, manufactured by Toray Industries, Inc., T
g = 428 ° C.), Novax (trademark name, Mitsubishi Chemical Corporation)
Manufactured by Tg = 399 ° C.), Upilex R (trade name, manufactured by Ube Industries, Ltd., Tg = 303 ° C.), Upilex S
(Trade name, Ube Industries, Ltd., Tg = 359 ° C.), La
rc TPI (trade name, manufactured by Mitsui Toatsu Chemicals, Inc., Tg =
256 ° C.) and the like.

The resin composition used in the molding method of the present invention contains other components, such as an inorganic filler, as long as the heat resistance, chemical resistance and surface appearance of the molded product are not impaired.
Elastomer other than component (B), thermoplastic resin other than component (B), plasticizer, heat stabilizer, antioxidant, weathering agent, nucleating agent, lubricant, antistatic agent, pigment, dye, flame retardant, flame retardant Auxiliary agents and the like can be added. The addition amount is preferably 0.01 to 100 parts by weight with respect to 100 parts by weight of the resin composition.

As the inorganic filler, iron oxide, alumina,
Oxides such as magnesium oxide and calcium oxide, hydrated metal compounds such as aluminum hydroxide, magnesium hydroxide, basic magnesium carbonate and calcium hydroxide, carbonates such as calcium carbonate and magnesium carbonate, talc, clay and bentonite. Borates such as silicates, barium borate, zinc borate, etc., glass fibers, potassium titanate fibers, metal coated glass fibers, ceramic fibers, wollastonite, fibrous fillers such as fibrous magnesium oxysulfate, etc. Can be mentioned. Among these, talc, glass fiber, potassium titanate fiber and fibrous magnesium oxysulfate are particularly preferable from the viewpoints of physical properties, handleability and economy.

The above-mentioned inorganic filler may be used after being surface-treated with a coupling agent or the like. The coupling agent may be appropriately selected from those known as silane coupling agents and titanium coupling agents. As the silane coupling agent, γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, β- (3,4
Aminosilanes such as -epoxycyclohexyl) ethyltrimethoxysilane, epoxysilanes are preferred. As the titanium-based coupling agent, isopropyl tri (N-
Amidoethyl, aminoethyl) titanate is preferred.
The surface treatment method can be carried out by a commonly known method and is not particularly limited. For example, a sizing treatment in which an organic solvent solution or suspension of a coupling agent is applied to a filler as a sizing agent, dry mixing using a Henschel mixer, a super mixer, a V-type blender, a spray method, an integral blend method, a dry method. It may be appropriately selected depending on the shape of the filler, such as a concentrate method, but it is preferably performed by a sizing treatment, a dry mixing, or a spray method.

Examples of elastomers other than the above-mentioned styrene-based elastomers that can be used in the molding method of the present invention include olefin-based elastomers, natural rubbers, polyamide elastomers, polybutadienes, polysulfide rubbers, thiochol rubbers, acrylic rubbers, urethane rubbers,
Examples thereof include silicone rubber, epichlorohydrin rubber, polyether / ester rubber, polyester / ester rubber and the like.

As the above-mentioned olefin elastomer,
It is a copolymer of α-olefins such as ethylene, propylene, 1-butene and 1-hexene, a copolymer of these with a non-conjugated diene, or a homopolymer of a higher α-olefin such as 1-hexene. It is an elastomeric polymer and has a Mooney viscosity ML measured at 100 ° C.
_{1 + 4} is usually 1 to 200, preferably 5 to 150, and more preferably 10 to 100. Among these olefin elastomers, ethylene elastomers are preferable in terms of quality and stability. In particular,
Ethylene / propylene copolymer rubber (EPM), ethylene / 1-butene copolymer rubber, ethylene / propylene /
1-butene copolymer rubber, ethylene / propylene / non-conjugated diene copolymer rubber (EPDM), ethylene / 1-butene / non-conjugated diene copolymer rubber, ethylene / propylene / 1-butene / non-conjugated diene copolymer There is a united rubber.
Specific examples of the non-conjugated diene include dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, dicyclooctadiene, methylenenorbornene, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, 5- Methylene-2-norbornene, 5-methyl-
1,4-hexadiene, 7-methyl-1,6-octadiene and the like can be mentioned.

Further, these elastomers may be modified with a modifier having a polar group. As the polar group, for example, acid hydride, carbonyl group, acid anhydride, acid amide, carboxylic acid ester, acid azide, sulfone group, nitrile group, cyano group, isocyanic acid ester, amino group, hydroxyl group, imide group, thiol group , Oxazoline groups, epoxy groups and the like. Particularly preferable polar groups are acid anhydrides and epoxy groups, and maleic anhydride group is preferable among the acid anhydrides.

Examples of the thermoplastic resin include polyesters such as polyethylene terephthalate, polycarbonates, polyethers such as polysulfone and polyether sulfone, condensation polymers such as polyamide, polyphenylene sulfide and polyoxymethylene, polyacrylic acid and polyacrylic acid ester. , Acrylic polymers such as polymethylmethacrylate, polyolefins such as polyethylene, polypropylene, polybutene, poly-4-methylpentene-1, ethylene-propylene copolymer, or polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride,
Examples thereof include halogen-containing vinyl compounds such as polyvinylidene fluoride.

Further, these thermoplastic resins may be modified with a modifier having a polar group. As the polar group, for example, acid hydride, carbonyl group, acid anhydride, acid amide, carboxylic acid ester, acid azide, sulfone group, nitrile group, cyano group, isocyanic acid ester, amino group, hydroxyl group, imide group, thiol group , Oxazoline groups, epoxy groups and the like. Particularly preferable polar groups are an acid anhydride and an epoxy group, and the acid anhydride is particularly preferably a maleic anhydride group.

[0046]

BEST MODE FOR CARRYING OUT THE INVENTION The following molds were used as the molds used in the examples and comparative examples of the present invention. Mold I: Made of steel (S55C), 100mm x 10
The mold surface of a mold having a 0 mm square and a flat cavity having a thickness of 2 mm was electrolyzed to a mirror-like hard chrome plating to a thickness of 0.02 mm to obtain a mold I for injection molding.

Mold II: The surface of the mold I was thoroughly degreased, and a linear polyimide precursor, polyimide varnish “Trenis # 3000” (trade name, manufactured by Toray Industries, Inc., Tg after curing =
300 ℃, thermal conductivity 0.0005cal / cm ・ sec
・ ° C, breaking elongation 60%), 120 ° C, 210
C. and 290.degree. C. in order of heat curing. This application and heat curing are repeated three times to form a polyimide layer. Then,
A diamond paste was attached to the buff and polished with an electric grinder to form a mirror-like linear polyimide coating layer having a thickness of 0.05 mm, which was used as an injection molding die II.

The surface temperature of the mold cavity was measured with a surface thermometer (model HL-200, thermocouple model C112, manufactured by Anritsu Keiki Co., Ltd.), and this was used as the mold temperature. The test methods used in Examples and Comparative Examples of the present invention will be described below. (1) For heat resistance, a test piece was cut into a size of 5 mm × 5 mm × 2 mm, and the softening temperature was measured according to JIS K7196. (2) The chemical resistance was evaluated by visually observing the appearance change of the test piece according to the following criteria after the test piece was immersed in methyl ethyl ketone at 23 ° C. for 24 hours.

⊚: No change, ◯: Slight change is observed, but usable: ×: Severe change, or completely dissolved and unusable. (3) The surface appearance is the gloss of the test piece according to JIS K71.
It measured based on 05. The reflection angle is 60 degrees. As the (A) syndiotactic styrene-based resin, (B) compatible thermoplastic resin and other compounds used in the examples and comparative examples of the present invention, the followings were used. (A) Syndiotactic styrene resin A-1: 1,2,4-trichlorobenzene as a solvent,
The weight average molecular weight measured by gel permeation chromatography at 130 ° C. was 310,000, the weight average molecular weight / number average molecular weight was 2.6, and the syndiotacticity in racemic pentad by the analysis of ¹³ C-NMR was 97. % Syndiotactic polystyrene. (B) Thermoplastic resin or elastomer B-1: atactic polystyrene (weight average molecular weight of 270,000 measured by gel permeation chromatography at 40 ° C. using chloroform as a solvent,
Homopolystyrene polymerized by thermal polymerization having a weight average molecular weight / number average molecular weight of 2.2).

B-2: Polyphenylene ether (US Pat. No. 4,788,277 (Japanese Patent Application No. 62-7757)
No. 0), 2,6-xylenol was subjected to oxidative coupling polymerization in the presence of dibutylamine to obtain poly (2,6-dimethyl-) having η (sp 2 /c)=0.42. 1,4-phenylene) ether) B-3: Styrene-based elastomer (styrene-hydrogenated butadiene block copolymer (trade name: H1052, manufactured by Asahi Chemical Industry Co., Ltd.) (C) Inorganic filler C-1: Talc (average particle size) Diameter 2.1 μm) C-2: Glass fiber (diameter 13 μm, length 3 m
m)

[0051]

Example 1 Components (A) and (B) were mixed in the predetermined amounts shown in Table 1.
The ingredients were dry-blended and adjusted. This is a co-rotating twin-screw extruder with a vent (inner diameter 40 mm, L / D = 4
6) was used and melt-kneaded at a barrel setting temperature of 300 ° C. to prepare pellets. During the melt-kneading, 0.1 part by weight of (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite as an antioxidant and tetrakis [methylene-3- (3 ', 5'-the-
0.1 part by weight of (t-butyl-4′-hydroxyphenyl)] was added. The pellets thus obtained are subjected to a mold II,
Molding temperature 300 ℃, mold temperature 80 ℃, cooling time 30se
Injection molding was performed at c to obtain a 100 mm × 100 mm × 2 mm test piece.

[0052]

Examples 2 to 4 The composition of Table 1 is the same as that of Example 1.

[0053]

Examples 5 to 7 The same as Example 1 except that the mold temperature was 130 ° C. with the composition shown in Table 1.

[0054]

Examples 8 to 10 Compositions shown in Table 1 are the same as in Example 1.

[0055]

[Comparative Examples 1 to 3] Using mold I, cooling time is 120 se
It is the same as each of Examples 1 to 3 except that it is c.

[0056]

[Comparative Example 4] The same as Example 2 except that the mold temperature was 170 ° C.

[0057]

[Comparative Examples 5 and 6] Using the mold I, the cooling time was 120 se.
Example 4 is the same as Example 4 except that it is c.

[0058]

[Comparative Example 7] Example 5 except that the mold temperature was 170 ° C.
Is the same as

[0059]

[Comparative Examples 8 and 9] Using the mold I, the cooling time was 120 se.
The procedures are the same as those in Examples 7 and 9 except that c is used.

[0060]

Comparative Example 10 The same as Example 9 except that the mold temperature is 170 ° C.

[0061]

[Table 1]

[0062]

[Table 2]

[0063]

EFFECT OF THE INVENTION It is possible to obtain a resin molded product which is more efficient than the conventional molding method and is excellent in heat resistance, chemical resistance and surface appearance.

Claims (5)

[Claims] 1. A styrene-based polymer (A) having a syndiotactic stereoregularity of 99 to 1% by weight, and (B) a whole or a part of a molecular chain is contained in an amorphous phase portion of a component (A). One or more kinds of thermoplastic resin composed of soluble segments or a resin composition composed of 1 to 99% by weight of an elastomer is melted at 270 to 370 ° C. and the thermal conductivity at 20 ° C. is 0.01 cal / cm · sec · ° C. or less. The wall temperature of the mold cavity coated with the heat insulating material is 20 to
A method for molding a resin molded product, which comprises molding at 150 ° C. using a mold having the mold cavity. 2. The molding method according to claim 1, wherein the component (B) is a styrene polymer other than the component (A). 3. The molding method according to claim 1, wherein the component (B) is a polyphenylene ether polymer. 4. The molding method according to claim 1, wherein the component (B) is a styrene elastomer. 5. The molding method according to claim 1, 2, 3, or 4, wherein the molding method is an injection molding method.