JP2005162903A - Styrenic rubber-containing resin composition for imc, and molded product by imc - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a styrenic rubber-containing resin composition for IMC, exhibiting excellent adhesion to a covering material and capable of being coated at a uniform thickness when being applied to the IMC; and to provide a molded product by the IMC, obtained by molding and coating by the IMC by using the styrenic rubber-containing resin composition. <P>SOLUTION: The styrenic rubber-containing resin composition as a base material resin usable for an inmold coating molding (IMC) method using a radically curable inmold coating composition as a coating agent comprises (A) a resin and (B) a radical scavenger, and satisfies the following conditions: (a) the compounded amount of the total of the radical scavenger (B) based on 100 pts. wt. resin component (A) is 0.01-0.3 pts. wt.; and (b) the deflection temperature under load of the styrenic rubber-containing resin composition measured by ISO 75 (A-method) is not lower than the curing temperature. The molded product by the IMC is obtained by molding the styrenic rubber-containing resin composition by the inmold coating and molding method using the radically curable inmold coating composition. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention efficiently forms a molded product used for interior / exterior parts of vehicles, interior / exterior products, electrical appliances, office automation equipment, etc., by an in-mold coating method using a radical curable in-mold coating composition. The present invention relates to a styrene rubber-containing resin composition for IMC as a base resin for the purpose, and an IMC molded product obtained by molding and coating the styrene rubber-containing resin composition by an in-mold coating method.

  Molds for the purpose of increasing quality and product value by adding value such as decorativeness to resin molded products used in automobiles, home appliances, building materials, etc., or reducing costs by reducing the molding process An integral molded product in which a thermosetting paint is injected between the surface of the resin molded product molded in the mold and the cavity surface of the mold, and then the paint is cured in the mold so that the coating film adheres to the surface of the resin molded product. An in-mold coating method (in-mold coating, hereinafter referred to as “IMC”) is being studied.

In the thermoplastic resin IMC, the present inventors set the mold temperature to a temperature higher than the curing temperature of the thermosetting paint, and cure the paint under a predetermined temperature, time, and other curing conditions. As a method for improving the physical properties of the obtained coating film while improving the productivity by shortening the molding cycle, and obtaining a good coating film molded product, JP-A-2001-38770, JP-A-2001-38783, JP 2001-38737 JP, 2001-138334, JP 2001-170964, JP 2001-096573, JP 2002-127198, JP 2002-127199, JP 2002-137255, JP 2002-172654, JP 2002-126654. Many proposals such as 172656, Japanese Patent Application Laid-Open No. 2002-172657, Japanese Patent Application Laid-Open No. 2003-191286 have been made.
JP 2001-38770 A JP 2001-38783 A JP 2001-38737 A JP 2001-138334 A JP 2001-170964 A JP2001-096573 JP2002-127198A JP 2002-127199 A JP 2002-137255 A JP2002-172654 JP 2002-172656 A JP2002-172657 JP2003-191286A

  As described above, IMC, which forms a coating film by curing a paint in a mold, is being established as an industrial production method. However, a radical curable in-mold coating composition is used as a coating agent, and is usually used as a base resin. When the ABS thermoplastic resin composition is molded by IMC, the adhesion of the coating film to the resin molding surface may be poor, and a good product may not be stably obtained. In addition, in order to make the pot life of the coating material about 1 day at room temperature, it is necessary to set the decomposition temperature of the currently available curing agent (organic peroxide) to about 80 ° C. More than that is required. However, when a normal ABS thermoplastic resin composition is injection molded at a mold temperature of 80 ° C. or higher and then IMC is performed, the coating material does not spread with a uniform thickness because the surface of the base resin is soft. There is also a problem that a coating film having a uniform thickness cannot be formed. Therefore, under the present circumstances, although IMC itself is being established as an industrial technique, it has not been possible to widely develop products by this method.

  Accordingly, an object of the present invention is to provide a styrene rubber-containing resin composition for IMC that exhibits excellent coating adhesion when applied to IMC and can be coated with a uniform thickness, and the styrene rubber-containing resin composition. It is to provide an IMC molded product formed and coated by IMC using the IMC.

The styrene rubber-containing resin composition for IMC of the present invention is a styrene rubber-containing resin composition as a base resin used in an in-mold coating method using a radical curable inner coating composition as a coating agent. It contains a resin component (A) and a radical scavenger (B), and satisfies the following conditions.
a) The total amount of the radical scavenger (B) is 0.01 to 0.3 parts by weight with respect to 100 parts by weight of the resin component (A).
b) The deflection temperature under load by ISO75 (Method A) of the styrene rubber-containing resin composition is equal to or higher than the curing temperature of the coating agent.

  The IMC molded article of the present invention is formed by molding and coating such a styrene rubber-containing resin composition of the present invention by an in-mold coating method using a radical curable in-mold coating composition as a coating agent. It is characterized by.

  That is, as a result of intensive studies to prevent the occurrence of defects such as poor adhesion of the coating film in IMC, the present inventors have formulated a specific load deflection in which a very small amount of the radical scavenger (B) is blended in the base resin. It was found that a styrene rubber-containing resin composition at a temperature could prevent these defects and obtain a good product with a high yield, thereby completing the present invention.

  In the present invention, it is extremely important to blend a very small amount of the radical scavenger (B), and the effect of the present invention is achieved only in this specific blending range of the radical scavenger (B). The

  A more preferable blending amount of the radical scavenger (B) is 0.01 to 0.2 parts by weight, more preferably 0.01 to 0.1 parts by weight with respect to 100 parts by weight of the resin component (A). Particularly preferred is 0.01 to 0.05% by weight.

  The operation mechanism of the present invention will be described below.

  The radical curable inner coating composition used as a coating agent for IMC in the present invention is generally a urethane acrylate oligomer having at least two (meth) acrylate groups using an organic peroxide as an initiator for the curing reaction. , Oligomers such as epoxy acrylate oligomers or resins thereof, or unsaturated polyester resin 20 to 70% by weight and methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl ( A vehicle component comprising 80-30% by weight of a copolymerizable ethylenically unsaturated monomer such as (meth) acrylate, (meth) acrylic acid, vinyl acetate, tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, styrene, etc. With the main component , It is made of various colored pigments, aluminum pigments, pearl pigments, mold release agents and light stabilizers.

  Here, as the organic peroxide, bis (4-t-butylcyclohexyl) peroxydicarbonate, diisopropylperoxydicarbonate, di-2-ethylhexylperoxydicarbonate, t-octylperoxyoctoate, t- Amyl peroxy octoate, t-butyl peroxy octoate, t-octyl peroxy benzoate, dibenzoyl peroxide, 1,1-di-t-butyl peroxycyclohexane, t-butyl peroxy-3,5,5 -Trimethylhexanoate, 2,2-di-t-butylperoxybutane, t-butylperoxyisopropyl carbonate, t-amylperoxybenzoate, t-butylperoxybenzoate and the like.

  In the curing reaction of the coating agent, the organic peroxide blended in the radical curable inner coating composition is decomposed by heat, and the polymerization reaction of oligomers and monomers starts by radicals generated at this time. Radical polymerization progresses in a chain. Since the decomposition temperature of the organic oxide is lower than the mold temperature, the coating agent injected into the gap between the base resin and the mold causes a curing reaction from both the mold wall surface and the base resin surface. Conceivable.

However, when such a radical curable in-mold coating composition is used as a coating agent and an ordinary ABS-based thermoplastic resin composition is used as a base resin and molded with IMC, the following problems are caused as described above. was there.
(1) The adhesion failure of the coating film to the resin molding surface occurs.
(2) A uniform thickness coating film cannot be obtained.

  The inventors of the present invention have made extensive studies to solve the above problem (1), and by making the content of the radical scavenger in the base resin a specific minimum amount, it is possible to stabilize the base resin during synthesis. It was found that the adhesion of the coating film to the resin molding surface can be sufficiently enhanced while ensuring the properties and preventing problems such as decomposition during molding.

  That is, the inventors firstly solved the above problem (1) with respect to the relationship between the coating agent and the base resin component, and the relationship between the coating agent and the base resin component. Verification was performed.

  In IMC, when the coating agent is injected into the mold and comes into contact with the base resin, the oligomer, monomer or composition in the coating composition that is the main component of the coating dissolves the surface layer of the base resin. To do. Then, the coating agent is cured in the dissolved layer, thereby forming a strong intermediate layer integrated with the base resin.

  At this time, the curing reaction is caused by radicals generated from the organic peroxide, but when the amount of radicals generated from the organic peroxide is large, the curing reaction occurs instantaneously, and as a result, the coating agent flows to the end. Can not be made. Therefore, in order to adjust the gelation time of the coating agent, it is necessary to put a predetermined amount of a radical scavenger that traps the radicals in the radical curable inner coating composition. In addition, after the coating agent is cured, the predetermined amount is required to provide weather resistance as a coating film.

  On the other hand, a predetermined amount of radical scavenger is generally blended into the base resin to ensure stability during polymerization and to prevent decomposition during molding. Then, the present inventors considered that the radical scavenger in the base resin may be a cause of reducing the adhesion between the coating agent and the base resin.

  That is, since the radical scavenger is contained not only in the coating agent but also in the base resin, in the IMC, in the dissolved layer at the interface between the two for expressing the adhesion between the coating agent and the base resin. Will be mixed with the radical scavenger in the radical curable inner coating composition and the radical scavenger in the base resin. For this reason, in the dissolved layer, radicals generated from the organic peroxide of the coating agent are captured by the radical scavenger derived from these coating agents and the radical scavenger derived from the base resin, and as a result, in this dissolved layer The coating will not be cured sufficiently. Conventionally, it is considered that the poor curing of the coating agent due to the excessive radical scavenger in the dissolved layer causes the poor adhesion.

  Based on the above findings, the inventors of the present invention, the amount of radical scavenger (B) in the base resin is an amount that does not impair the curing reaction of the coating in the dissolved layer in the IMC, On the other hand, the problem (1) has been solved by adjusting the amount to a specific minimum amount that can ensure sufficient stability during resin synthesis and prevention of decomposition during molding.

  In the past, there has been no study on the curing failure caused by the amount of the radical scavenger in the dissolved layer at the interface between the coating agent and the base resin for expressing adhesion in IMC. It was first elucidated by their research.

  The inventors of the present invention have also made extensive studies to solve the above problem (2), and by making the load deflection temperature of the base resin according to ISO 75 (Method A) equal to or higher than the curing temperature of the coating agent, It has been found that a coating film having a uniform thickness can be formed by diffusing and flowing a coating agent mixed between a mold and a base resin with a uniform thickness.

  That is, in order to solve the problem (2), the present inventors have conducted the following investigations on the mold temperature during IMC, the curing temperature of the coating agent, and the physical properties of the base resin.

  In the IMC method, in order to cure the coating agent, the mold temperature is set to a decomposition temperature of the curing agent (organic oxide) or slightly higher. This mold temperature is a temperature of 80 to 100 ° C. in a coating agent usually used for IMC. And since the base resin is injected and held in the mold at such a temperature and the surface of the base resin is solidified enough to withstand the injection pressure and flow pressure of the coating agent, the coating agent is injected. is there. At this time, if the base resin is not sufficiently solidified and cannot withstand the injection pressure and flow pressure of the coating, the coating does not flow with a uniform thickness, or the distance through which the coating flows is shortened. This causes a non-uniform thickness of the formed coating film.

  For these reasons, the present inventors need that the base resin to which the IMC method is applied must be solidified to some extent at the curing temperature of the coating agent, and express this solidified physical property. As an indicator, the heat deformation temperature of the base resin (the deflection temperature under load according to ISO 75 (Method A)) is most suitable, and a new finding has been obtained that it is an approximate standard.

  Based on such knowledge, in the present invention, the load deflection temperature according to ISO75 (Method A) as the physical property of the base resin is adjusted, the fluidity of the coating material in the IMC method is improved, and the uniform thickness is improved. A styrene rubber-containing resin composition capable of forming a coating film was developed.

  According to the present invention, an IMC molded product excellent in appearance (molded product appearance and painted appearance), coating film adhesion, that is, coating film strength, can be produced with high yield. Therefore, it is possible to effectively apply IMC, which is excellent in productivity and saving processes, to the molding of products in a wide range of fields.

  Embodiments of a styrene rubber-containing resin composition for IMC and an IMC molded product according to the present invention will be described in detail below.

  In the present invention, IMC, that is, in-mold coating molding method, is a method in which a thermosetting paint is injected between the surface of a resin molded product molded in a mold and the cavity surface of the mold, and then the paint is applied. Is molded in the mold to produce an integrally molded product having a coating film in close contact with the surface of the resin molded product, preferably the surface temperature of the resin molded product is the curing temperature of the paint Higher and the mold temperature on the cavity side is lower than the curing temperature of the paint.

  Further, in the present invention, the radical curable inner coating composition used as a coating agent for IMC has, as described above, at least two (meth) acrylate groups having an organic peroxide as a curing reaction initiator. Oligomers such as urethane acrylate oligomer, epoxy acrylate oligomer or the like, or unsaturated polyester resin 20 to 70% by weight, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) 80-30 wt% of copolymerizable ethylenically unsaturated monomer such as acrylate, 2-ethylhexyl (meth) acrylate, (meth) acrylic acid, vinyl acetate, tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, styrene % Vehicle Min as a main component, a radical scavenger, various coloring pigments, aluminum pigments, is made of a pearl pigment, a releasing agent and a light stabilizer and the like.

  Here, as the organic peroxide, bis (4-t-butylcyclohexyl) peroxydicarbonate, diisopropylperoxydicarbonate, di-2-ethylhexylperoxydicarbonate, t-octylperoxyoctoate, t- Amyl peroxy octoate, t-butyl peroxy octoate, t-octyl peroxy benzoate, dibenzoyl peroxide, 1,1-di-t-butyl peroxycyclohexane, t-butyl peroxy-3,5,5 -1 type, or 2 or more types, such as -trimethylhexanoate, 2,2-di-t-butylperoxybutane, t-butylperoxyisopropyl carbonate, t-amylperoxybenzoate, and t-butylperoxybenzoate Radical curable inner coating composition Content in is usually about 0.1 to 10% by weight relative to vehicle components described above.

  Further, as described above, this radical curable inner coating composition is composed of p-benzoquinone, naphthoquinone, 2,5-diphenyl-p-benzoquinone, hydroquinone, pt-butylcatechol, mono-t-butylhydroquinone, 2 , 5-di-t-butylhydroquinone, di-t-butylparacresol hydroquinone monomethyl ether, copper naphthenate, quinonedioxime, cyclohexanone oxime, resorcin and other radical scavengers, It is about 0.005 to 0.3% by weight with respect to the above-mentioned vehicle component.

The styrene rubber-containing resin composition of the present invention is applied to such an IMC using a radical curable inner coating composition as a coating agent, and comprises a resin component (A) and a radical scavenger (B). In addition, the following conditions are satisfied.
a) The total amount of the radical scavenger (B) is 0.01 to 0.3 parts by weight with respect to 100 parts by weight of the resin component (A).
b) The deflection temperature under load by ISO75 (Method A) of the styrene rubber-containing resin composition is 80 ° C. or higher.

  The resin component (A) of the present invention contains a styrene-based rubber-containing resin composition, may be composed of one or more styrene-based rubber-containing resins, and contains one or more styrene-based rubbers. It may be an alloy of resin and one or more other various thermoplastic resins. This styrene rubber-containing resin is a rubber-containing graft copolymer obtained by graft polymerization of at least one vinyl monomer in the presence of a rubbery polymer. The thermoplastic resin alloyed with the styrene rubber-containing resin is a polymer or hard copolymer that does not contain a rubbery polymer and is obtained by polymerizing or copolymerizing at least one vinyl monomer. It is a coalescence.

  Examples of the rubbery polymer used in the styrene rubber-containing resin include polybutadiene, polyisoprene, butyl rubber, styrene-butadiene copolymer (styrene content is preferably 5 to 60% by weight), styrene-isoprene copolymer, Acrylonitrile-butadiene copolymer, ethylene-α-olefin copolymer, ethylene-α-olefin-nonconjugated diene copolymer, silicon rubber, polyurethane rubber, acrylic rubber, butadiene- (meth) acrylic acid ester copolymer, Examples thereof include a styrene-butadiene block copolymer, a styrene-isoprene block copolymer, and a styrene-butadiene block copolymer.

As the α-olefin used in the ethylene-α-olefin-nonconjugated diene copolymer, propylene is preferable. As the nonconjugated diene, dicyclopentadiene, 5-ethylidene-2-norbornene, 5-vinylnorbornene, 1,4 -Hexadiene, 1,4-cyclopentadiene and the like are preferable. In addition, the weight ratio of ethylene and α-olefin such as propylene in these copolymers is preferably 90:10 to 20:80. The styrene-butadiene block copolymer and styrene-isoprene block copolymer include those having an AB type, ABA type, tapered type, radial teleblock type structure, and the like.
Examples of the styrene rubber-containing resin further include hydrogenated diene polymers. In addition to the hydride of the block copolymer, a hydride of a block body of a styrene block and a styrene-butadiene random copolymer, polybutadiene. Examples thereof include a hydride of a polymer comprising a block having a 1,2-vinyl bond content of 20% by weight or less and a polybutadiene block having a 1,2-vinyl bond content exceeding 20% by weight.

  Examples of the acrylic rubber include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, isobutyl acrylate, pentyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-methylpentyl acrylate, 2-ethylhexyl acrylate, and n-octyl acrylate. .

  Of these, polybutadiene, styrene-butadiene copolymer, ethylene-α-olefin copolymer, hydrogenated diene polymer (homo, block and random), and silicone rubber are preferable as the rubber polymer.

  These rubbery polymers may contain only one kind in the styrene rubber-containing resin, or may contain two or more kinds.

  Examples of vinyl monomers used in the styrene rubber-containing resin include aromatic vinyl compounds, vinyl cyanide compounds, (meth) acrylic acid esters, and the like.

  Examples of the aromatic vinyl compound include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-hydroxystyrene, α-ethylstyrene, methyl-α-methylstyrene, dimethylstyrene, and pt-butoxystyrene. , Bromostyrene, tribromostyrene, divinylstyrene, vinylpyridine, vinylxylene, 1,1-diphenylstyrene, fluorostyrene, chlorostyrene, dichlorostyrene, trichlorostyrene, sodium stilsulfonate, and the like. Among these, styrene and α-methylstyrene are preferable. These aromatic vinyl compounds may be used alone or in combination of two or more. The amount of the aromatic vinyl compound used is preferably 45 to 90% by weight, more preferably 45 to 80% by weight, particularly preferably 45 to 70% by weight in the vinyl monomer, and less than 45% by weight is sufficient. If the moldability exceeds 90% by weight, impact resistance cannot be obtained, which is not preferable.

  Examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile, and these may be used alone or in combination of two or more. As this vinyl cyanide compound, acrylonitrile is particularly preferable. The amount of the vinyl cyanide compound used is preferably 5 to 50% by weight, more preferably 5 to 40% by weight, and particularly preferably 5 to 30% by weight in the vinyl monomer. When the content exceeds 50% by weight, the color tone of the rubber-reinforced thermoplastic resin obtained is brown, and molding processability and thermal stability during molding are inferior.

  (Meth) acrylic acid esters include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amino acrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, dodecyl acrylate, octadecyl acrylate, phenyl acrylate, benzyl acrylate, etc. Acrylic ester of methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amino methacrylate, hexyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, dodecyl methacrylate, octadecyl methacrylate Phenylme Acrylate, methacrylic acid esters such as benzyl methacrylate and the like, which are used alone or in combination. Of these, butyl acrylate and methyl methacrylate are preferred. The amount of the (meth) acrylic acid ester used is preferably 30% by weight or less, more preferably 20% by weight or less, particularly preferably 10% by weight or less in the vinyl monomer, and more than 30% by weight. The deflection temperature under load tends to decrease.

  In addition to the above vinyl monomers, the styrene rubber-containing resin can be used in combination with other vinyl monomers copolymerizable with these in a total vinyl monomer of about 40% by weight or less. Examples of other copolymerizable vinyl monomers include maleimide compounds, unsaturated acids, acid anhydride group-containing unsaturated compounds, epoxy group-containing unsaturated compounds, amino group-containing unsaturated compounds, and hydroxyl group-containing unsaturated monomers. Saturated compounds, oxazoline group-containing unsaturated compounds, and the like can be mentioned, and these can be used alone or in admixture of two or more.

  As maleimide compounds, maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N- (2-methyl) Phenyl) maleimide, N- (2,6-diethylphenyl) maleimide, N- (4-carboxyphenyl) maleimide, N- (4-hydroxyphenyl) maleimide, N- (4-bromophenyl) maleimide, tribromophenylmaleimide , N- (4-chlorophenyl) maleimide and the like. Of these, N-phenylmaleimide and N-cyclohexylmaleimide are preferable.

  Examples of the unsaturated acid include acrylic acid, methacrylic acid, and maleic acid. Examples of the acid anhydride group-containing unsaturated compound include maleic anhydride, citraconic anhydride, itaconic anhydride and the like. Furthermore, examples of the epoxy group-containing unsaturated compound include glycidyl methacrylate and allyl glycidyl ether. Furthermore, examples of the amino group-containing unsaturated compound include acrylic amine, aminoethyl methacrylate, aminopropyl methacrylate, aminostyrene, acrylic styrene, acrylamide, and methacrylamide.

  Examples of the hydroxyl group-containing unsaturated compound include hydroxystyrene, 3-hydroxy-1-propene, 4-hydroxy-1-butene, cis-4-hydroxy-2-butene, trans-4-hydroxy-2-butene, 3- Hydroxy-2-methyl-1-propene, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate and the like can be mentioned. Furthermore, vinyl oxazoline etc. are mentioned as an oxazoline group containing unsaturated compound.

  The styrene rubber-containing resin can be produced by polymerizing the vinyl monomer in the presence of the above-described rubber polymer by ordinary emulsion polymerization, solution polymerization, bulk polymerization, suspension polymerization, or the like. However, it is preferably produced by emulsion polymerization of a vinyl monomer in a latex of a rubbery polymer. In this case, the latex of the rubbery polymer has a rubber particle average particle diameter of 0.2 to 0.8 μm, preferably 0.25 to 0.5 μm. When a latex having an average particle size in this range is used, a high balance of physical properties can be realized. The above-mentioned vinyl monomers can be added to the reaction system all at once or continuously.

  The ratio of the rubbery polymer in the styrene rubber-containing resin is preferably 5 to 50% by weight, more preferably 10 to 40% by weight, based on the total amount of the rubbery polymer and the vinyl monomer. If this proportion is less than 5% by weight, the impact strength is undesirably lowered. On the other hand, if it exceeds 50% by weight, the moldability, the elastic modulus and the heat distortion temperature are undesirably lowered.

  In the present invention, the styrene rubber-containing resin is a resin composition using at least a styrene component as a rubbery polymer and / or a vinyl monomer.

  The resin component (A) in the present invention may be composed of only one or two or more of the styrene rubber-containing resins as described above, and does not include a styrene rubber-containing resin and a rubbery polymer. You may be comprised with 1 type, or 2 or more types of other thermoplastic resins, such as a hard copolymer.

  As the resin used as an alloy with the styrene rubber-containing resin, various known resins such as polycarbonate, polybutylene terephthalate, polyethylene terephthalate, polyamide, polyphenylene ether, and the like can be used, but polycarbonate is preferable from the viewpoint of impact resistance.

  Examples of the polycarbonate resin include those obtained by reaction of various dihydroxyaryl compounds with phosgene (phosgene method), and those obtained by transesterification of dihydroxyaryl compounds and diphenyl carbonate (transesterification method). A typical polycarbonate is 2,2′-bis (4-hydroxyphenyl) propane, that is, a polycarbonate obtained by the reaction of bisphenol A and phosgene.

  Here, examples of the dihydroxyaryl compound used as a raw material for polycarbonate include bis (4-hydroxyphenyl) methane, 1,1′-bis (4-hydroxyphenyl) ethane, and 2,2′-bis (4-hydroxyphenyl) propane. 2,2'-bis (4-hydroxyphenyl) butane, 2,2'-bis (4-hydroxyphenyl) octane, 2,2'-bis (4-hydroxyphenyl) phenylmethane, 2,2'-bis (4-hydroxy-3-methylphenyl) propane, 2,2′-bis (4-hydroxy-3-tert-butylphenyl) propane, 2,2′-bis (4-hydroxy-3-bromophenyl) propane, 2,2'-bis (4-hydroxy-3,5-dichlorophenyl) propane, 1,1'-bis (4-hydroxyphenyl) cyclo Lanthanum, 1,1'-bis (4-hydroxyphenyl) cyclohexane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 4,4'-dihydroxyphenyl sulfide, 4, 4'-dihydroxy-3,3'-dimethylphenyl sulfide, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-dimethylphenyl sulfide, 4,4'-dihydroxyphenyl sulfoxide, 4, 4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone, hydroquinone, resorcin and the like. Single or two or more Mixed and used in. Particularly preferred is 2,2'-bis (4-hydroxyphenyl) propane, ie bisphenol A.

  The viscosity average molecular weight of the polycarbonate resin is preferably 15,000 to 35,000, more preferably 17,000 to 28,000, and particularly preferably 18,000 to 26,000. When the viscosity average molecular weight is less than 15,000, the impact resistance is inferior, whereas when it exceeds 35,000, the fluidity is inferior.

  In addition, as polycarbonate resin, 2 or more types from which molecular weight differs can also be mixed and used.

  In an alloy of a styrene rubber-containing resin and another thermoplastic resin such as a polycarbonate resin, the composition ratio is such that the amount of other thermoplastic resin compounded such as a polycarbonate resin is 10 to 80 parts by weight of the rubber-reinforced thermoplastic resin. It is preferable that it is 90-20 weight part.

  The radical scavenger (B) used in the present invention is a compound used for the purpose of stabilizing the interior of the resin by capturing radicals generated inside the resin by light, heat, or the like. Examples of the radical scavenger (B) include phenolic compounds and amine compounds. The phenolic compounds are generally phenolic antioxidants, and the amine compounds are generally amine UV stabilizers. Is commercially available.

  Examples of phenolic antioxidants include 2,6-ditert-butyl-p-cresol, 2,6-diphenyl-4 octoxyphenol, and stearyl- (3,5-dimethyl-4-hydroxybenzyl) thioglycolate. Stearyl-β- (4-hydroxy-3,5-ditert-butylphenyl) propionate, distearyl-3,5-ditert-butyl-4-hydroxybenzylphosphonate, 2,4,6-tris (3 ′ , 5'-ditert-butyl-4-hydroxybenzylthio) 1,3,5-triazine, distearyl (4-hydroxy-3-methyl-5-tert-butyl) benzyl malonate, 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 4,4'-methylenebis (2,6-ditert-butylphenol), 2,2'-methylenebis 6- (1-methylcyclohexyl) p-cresol], bis [3,5-bis (4-hydroxy-3-tert-butylphenyl) butyric acid] glycol ester, 4,4'-butylidenebis (6-tertiary Butyl-m-cresol), 2,2'-ethylidenebis (4,6-ditertiarybutylphenol), 2,2'-ethylidenebis (4-secondarybutyl-6-tertiarybutylphenol), 1,1, 3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, bis [2-tert-butyl-4-methyl-6- (2-hydroxy-3-tert-butyl-5-methylbenzyl) ) Phenyl] terephthalate, 1,3,5-tris (2,6-dimethyl-3-hydroxy-4-tert-butyl) benzyl isocyanurate, 1,3,5- (3,5-ditert-butyl) -4-hydroxybenzyl) -2,4,6-trimethylbenzene, tetrakis [methylene-3- (3,5-ditert-butyl-4-hydroxyphenyl) propionate] methane, 1,3,5-tris (3 , 5-Ditertiarybutyl-4-hydroxybenzyl) isocyanurate, 1,3,5-tris [(3,5-ditertiarybutyl-4-hydroxyphenyl) propionyloxyethyl] isocyanurate, 2-octylthio- 4,6-di (4-hydroxy-3,5-di-tert-butyl) phenoxy-1,3,5-triazine, 4,4'-thiobis (6-tert-butyl-m-cresol), 2,2 '-Methylenebis (6-tert-butyl-4-methylphenol) monoacrylate, triethylene glycol bis [3- (3-tert-butyl-4-hydroxy-5-methyl) Phenyl) propionate], 3,9-bis (1,1-dimethyl-2-hydroxyethyl) 2,4,8,10-tetraoxaspiro [5,5] undecanbis [3- (3-tert-butyl- Hindered phenol compounds such as 4-hydroxy-5-methylphenyl) propionate]. These may be used alone or in combination of two or more.

  Examples of the amine UV stabilizer include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1, 2,3,4-tetrakis (2,2,6,6-tetramethyl-4-piperidyloxycarbonyl) butane, 1,2,3,4-tetrakis (1,2,2,6,6-pentamethyl-4 -Piperidyloxycarbonyl) butane, dimethyl succinate-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate, 2- (3,5-di-t- Butyl-4-hydroxybenzyl) -2-n-butylmalonate bis (1,2,2,6,6-pentamethyl-4-piperidyl), 1,2,3,4-butane-tetracarboxylic acid and 1,2 , 2 Polycondensate of 6,6 pentamethyl-4-piperidinol and 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxospiro [5,5] undecane 1- (3,5-di-tert-butyl-4-hydroxyphenyl) -1,1-bis (2,2,6,6-tetramethyl-4-piperidyloxycarbonyl) pentane, 1- [2- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy]- 2,2,6,6-tetramethylpiperidine, N, N′-bis (3-aminopropyl) ethylenediamine · 2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl -4 piperidyl) Mino] -6-chloro-1,3,5-triazine condensate, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, poly [{6- (1,1,3,3-tetramethyl Butyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetra Hindered amine compounds such as methyl-4-piperidyl) imino}] and bis (1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate. These may be used alone or in combination of two or more.

  Since the hindered amine ultraviolet stabilizer exhibits a remarkable effect on ultraviolet rays when used in combination with the ultraviolet absorber, an ultraviolet absorber may be used in combination with the hindered amine ultraviolet stabilizer. As the ultraviolet absorber, a benzotriazole type is preferable. Specifically, 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] 2H-benzotriazole, 2- ( 3,5-di-tert-butyl-2-hydroxyphenyl) benzotriazole, 2- (3-tert-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5- Di-t-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t-amyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy) -5'-t-octylphenyl) benzotriazole and the like. These may be used alone or in combination of two or more.

  However, it is more preferable to use only the hindered amine-based ultraviolet stabilizer than the combined use of the hindered amine-based ultraviolet stabilizer and the ultraviolet absorber from the viewpoint of less discoloration of the molded product.

  In addition, a hindered phenol type compound and a hindered amine type compound may each be used independently, and may be used together, respectively.

  In this invention, the compounding quantity of such a radical scavenger (B) shall be 0.01-0.3 weight part with respect to 100 weight part of a resin component (A).

  In the present invention, it is extremely important to blend the radical scavenger (B) in such a very limited specific minute amount, and the effects of the present invention can be achieved only in this specific blending range of the radical scavenger (B). Is achieved. When the blending amount of the radical scavenger (B) with respect to 100 parts by weight of the resin component (A) is less than 0.01 parts by weight, the adhesion and water resistance of the coating film are inferior. In addition, the coating film adhesion is poor. A more preferable blending amount of the radical scavenger (B) is 0.01 to 0.2 parts by weight, more preferably 0.01 to 0.1 parts by weight with respect to 100 parts by weight of the resin component (A). Particularly preferred is 0.01 to 0.05% by weight.

  In the styrene rubber-containing resin composition according to the present invention, the deflection temperature under load according to ISO 75 (Method A) needs to be equal to or higher than the curing temperature of the coating agent. If the deflection temperature under load is lower than the curing temperature of the coating agent, the molded appearance and the painted appearance become poor, which is not preferable. The deflection temperature under load is preferably 10 ° C. or more, particularly 15 to 20 ° C. higher than the curing temperature of the coating agent.

  In order to obtain a styrene-based rubber-containing resin composition for IMC having a deflection temperature under load of ISO 75 (Method A) of 80 ° C. or higher, which is the curing temperature of a general radical curable coating agent, a rubber-containing graft copolymer and a heat-resistant What is necessary is just to mix | blend suitably the hard copolymer which copolymerized (alpha) -methylstyrene and N-phenylmaleimide as a component, and you may use together 2 or 3 types of different hard copolymers.

  In the styrene rubber-containing resin composition of the present invention, as necessary, glass fiber, carbon fiber, wollastonite, talc, mica, kaolin, glass beads, glass flake, milled fiber, zinc oxide whisker, potassium titanate Fillers such as whiskers can be blended alone or in combination of two or more. By blending these fillers, rigidity can be imparted to the styrene rubber-containing resin composition of the present invention. In particular, by adding talc or the like, matte properties can be imparted to the styrene rubber-containing resin composition of the present invention. As a preferable shape of the glass fiber or carbon fiber, the fiber diameter is 6 to 20 μm, and the fiber length is 30 μm or more.

  In the styrene rubber-containing resin composition of the present invention, flame retardants, flame retardant aids such as antimony compounds, known coupling agents, antibacterial agents, antifungal agents, antioxidants, weather resistance (light resistance) agents, Additives such as plasticizers, colorants (pigments, dyes, etc.), lubricants, antistatic agents and the like can be blended within a range that does not impair the required performance. However, about the component which functions as a radical scavenger, it is necessary to set it as the compounding quantity of the above-mentioned specific range.

  The IMC molded product of the present invention is obtained by molding and painting by IMC using a radical curable inner coating composition with the styrene rubber-containing resin composition of the present invention as a coating agent. Examples of such IMC molded products include vehicle interior / exterior parts, OA / home appliances, electrical / electronic equipment parts, interior / exterior products, sanitary article parts, miscellaneous goods, and the like. More specifically, vehicle interior and exterior parts include various pillars including center pillars, garnishes such as front garnish and rear garnish, and electrical and electronic parts include various housings such as personal computers, PDPs, projectors, and video. The sanitary article parts include toilet seat lids, bathtub panels, and the like.

  In addition, the film thickness of the coating film formed on the surface of the resin molded product by IMC is about 40 to 100 μm.

  In order to recycle the molded product obtained from the styrene rubber-containing resin composition of the present invention, the pulverized product obtained by pulverizing the molded product is 5% by weight or more, preferably 10% by weight or more, more preferably 20% by weight or more. It can also be mixed with a virgin resin or the like, molded in the same manner as the styrene rubber-containing resin composition of the present invention, and used as a recycled molding material. For example, the molded product obtained from the styrene-based rubber-containing resin composition of the present invention is used as a recovered material, and this is pulverized, washed, and foreign matter removed, and if necessary, used as a raw material together with virgin resin, and homogenized by tumbling treatment To do. Here, the ratio of the recovered resin in the raw material is 5% by weight or more, preferably 10% by weight or more, more preferably 20 to 90% by weight, and particularly preferably 30 to 80% by weight. If this ratio is less than 5% by weight, the recycling efficiency is lowered. On the other hand, when the ratio is 100% by weight, the recycling efficiency is most preferable. However, as the ratio is increased, the performance as a recycled material, in particular, the appearance of a molded product is deteriorated due to an increase in the amount of foreign matter, and the physical property value of the material may be lowered. As described above, the recovered resin is tumbled together with a virgin resin as necessary, and is homogenized by tumbling.Then, the recovered resin is put into a vented extruder equipped with a metal net on the die head, pelletized, It can be the final recycled material. The reclaimed molding material obtained in this way has physical properties almost the same as virgin resin, and can be used in the same manner as the styrene rubber-containing resin composition of the present invention.

  Hereinafter, the present invention will be described more specifically with reference to synthesis examples, examples, comparative examples, and reference examples. However, the present invention is not limited to the following examples unless it exceeds the gist. . In the following, “parts” means “parts by weight”, and the weight average molecular weight of the hard polymer is converted to standard polystyrene using GPC (gel permeation chromatography) manufactured by Tosoh Corporation. Calculated by the method.

In the following examples, comparative examples, and reference examples, the following resins were used.
PC: Polycarbonate resin Mitsubishi Engineering Plastics Co., Ltd .: S-1000F
PA: Nylon resin Ube Industries, Ltd .: 1013B
PET: Polyethylene terephthalate resin
Unitika Ltd .: GP1045
HIPS: High impact polystyrene resin
Nippon Polystyrene Co., Ltd .: H550
PP: Polypropylene resin Idemitsu Petrochemical Co., Ltd .: J-700G

  In addition, as a hindered phenol-based antioxidant, Yoshida Pharmaceutical Co., Ltd .: A02246 [2,2'-methylenebis (4-methyl-6-tert-butylphenol)] / (molecular weight 340.51) was used, and a hindered amine was used. Sankyo LS-770 [Bis (2,2,6,6-tetramethyl-4-piberidyl) sebacate] manufactured by Sankyo Co., Ltd. was used as a system ultraviolet stabilizer.

Synthesis Example 1: Production of rubber-containing graft copolymer (b-1) An ABS copolymer was synthesized by the emulsion polymerization method with the following composition.
Styrene (ST) 30 parts Acrylonitrile (AN) 10 parts Polybutadiene latex 60 parts Disproportionated potassium rosin acid 1 part Potassium hydroxide 0.03 parts Tertiary decyl mercaptan (t-DM) 0.1 part Cumene hydroperoxide 0 .3 parts Ferrous sulfate 0.007 parts Sodium pyrophosphate 0.1 parts Crystalline glucose 0.3 parts Distilled water 190 parts

  Charge the autoclave with distilled water, disproportionated potassium rosinate, potassium hydroxide and polybutadiene latex, heat to 60 ° C, add ferrous sulfate, sodium pyrophosphate, and crystalline glucose, and keep it at 60 ° C. AN, t-DM and cumene hydroperoxide were continuously added over 2 hours, and then the temperature was raised to 70 ° C. and maintained for 1 hour to complete the reaction. An antioxidant was added to the ABS latex obtained by this reaction, then coagulated with sulfuric acid, sufficiently washed with water, and dried to obtain an ABS graft copolymer.

Synthesis Example 2: Production of rubber-containing graft copolymer (b-2) AAS graft in the same manner as in Synthesis Example 1, except that 10 parts of acrylonitrile and 30 parts of styrene were reacted in the presence of 60 parts of polybutyl acrylate rubber. A copolymer was obtained.

Synthesis Example 3: Production of rubber-containing graft copolymer (b-3) Ethylene-propylene-nonconjugated diene copolymer rubber latex having a gel content of 65% [ethylene: propylene = 75: 25 (parts by weight)] 60 AES graft copolymer in the same manner as in Synthesis Example 1 except that 40 parts of a vinyl monomer mixture composed of 70% by weight of styrene and 30% by weight of acrylonitrile was added to 100 parts by weight (solid content). Got.

Synthesis Example 4: Production of Rigid Copolymer (c-1) 120 parts of distilled water, 0.002 part of sodium alkylbenzenesulfonate, 0.5 part of polyvinyl alcohol, 0.3 part of azoisobutylnitrile in a nitrogen-substituted reactor A vinyl monomer mixture consisting of 42 parts of acrylonitrile and 58 parts of styrene was added, heated at a starting temperature of 60 ° C. for 5 hours, heated to 120 ° C., reacted for 4 hours, and the polymer was taken out. The obtained polymer had a conversion rate of 96% and a weight average molecular weight of 126,000.

Synthesis Example 5 Production of Rigid Copolymer (c-2) Synthesis was performed except that a vinyl monomer mixture consisting of 25 parts of acrylonitrile, 24 parts of styrene, 36 parts of α-methylstyrene and 15 parts of N-phenylmaleimide was used. Polymerization was carried out in the same manner as in Example 4. The obtained polymer had a conversion rate of 98% and a weight average molecular weight of 130,000.

Examples 1 to 9, Comparative Examples 1 to 6, Reference Examples 1 and 2
Each material was hescheled together with 0.5 parts by weight of the lubricant in the proportions shown in Tables 1 and 2, and then at 260 ° C. with a twin screw extruder (manufactured by Toshiba Corporation, trade name: TEX-44). Melt mixed and pelletized.

  Tables 1 and 2 show the deflection temperatures under load of the obtained styrene-based rubber-containing resin composition according to ISO 75 (Method A).

  Using the obtained pellets, the IMC apparatus shown in FIG. 1 (“PZIII 350-I18A” manufactured by Ube Industries Co., Ltd. (impressed molding specification)) is used for the flowchart and the mold clamping / die opening sequence shown in FIG. Based on this, the motorcycle side cover (320 mm × 180 mm) 1 having the shape shown in FIG. 3 was molded. (Cylinder temperature: 240 ° C., mold temperature: 95 ° C. setting).

  As a coating agent, Dainippon Paint Co., Ltd .: radical curing type inner coating agent “Praglas # 8000” (black) was used to form a coating film having a thickness of 50 μm. The composition of the coating is as shown in Table 3. The curing temperature of this coating agent is 80 ° C.

The obtained IMC molded product was evaluated as follows, and the results are shown in Tables 1 and 2.
Molded product appearance: Observed by visual observation and evaluated according to the following criteria.
A: Very good
○: Good
Δ: Normal
×: Generation of gate mark
XX: Generation of a plurality of defective phenomena Paint appearance: Observed by visual observation and evaluated according to the following criteria.
A: Very good
○: Good
△: There is a little bit
×: Partially uncured part generated
XX: Mostly uncured part generated Water resistance: After immersing in warm water at 40 ° C for 240 hours, the state of the coating film was examined and evaluated according to the following criteria.
A: Very good
○: Good
X: Exfoliation of coating film Adhesion of coating film: Evaluated by a cross cut cell tape test of JIS K-5400.

  From Tables 1 and 2, it can be seen that according to the present invention, it is possible to obtain an IMC molded product that is excellent in the appearance of the molded product and the appearance of the coating, and has good coating film adhesion.

It is the schematic which shows the IMC apparatus used in the Example, the comparative example, and the reference example. It is the flowchart and the mold clamping / die opening sequence which were employ | adopted in the Example, the comparative example, and the reference example. It is a figure of the two-wheeled vehicle side cover shape | molded in the Example, the comparative example, and the reference example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Two-wheeled vehicle side cover 10 Mold clamping device 11 Fixed platen 12 Movable platen 13 Clamping cylinder 14 Tie rod 15 Mold clamping servo valve 17 Mold opening sensor 18 Mold clamping force sensor 20 Injection device 21 Screw 22 Barrel 23 Hydraulic motor 24 Injection cylinder 25 Hopper 26 Nozzle 27 Injection servo valve 30 Control device 31 Molding device control unit 32 Mold clamping condition setting unit 33 Mold clamping control unit 35 Injection machine control unit 38 Injection control unit 50 Mold device 51 Fixed mold 52 Movable mold 53 Mold Mold cavity 54 Temperature sensor 55 Paint injection machine 100 Mold coating equipment

Claims (7)

A styrene-based rubber-containing resin composition as a base resin used in an in-mold coating method using a radical curable in-mold coating composition as a coating agent, comprising a resin component (A) and a radical scavenger (B) A styrene rubber-containing resin composition for IMC, which satisfies the following conditions.
a) The total amount of the radical scavenger (B) is 0.01 to 0.3 parts by weight with respect to 100 parts by weight of the resin component (A).
b) The deflection temperature under load by ISO75 (Method A) of the styrene rubber-containing resin composition is equal to or higher than the curing temperature of the coating agent.   The styrene rubber for IMC according to claim 1, wherein the total amount of the radical scavenger (B) is 0.01 to 0.2 parts by weight with respect to 100 parts by weight of the resin component (A). Containing resin composition.   3. The styrene rubber for IMC according to claim 2, wherein the total amount of the radical scavenger (B) is 0.01 to 0.1 parts by weight with respect to 100 parts by weight of the resin component (A). Containing resin composition.   The styrene rubber for IMC according to claim 3, wherein the total amount of the radical scavenger (B) is 0.01 to 0.05 parts by weight with respect to 100 parts by weight of the resin component (A). Containing resin composition.   5. The styrene rubber-containing resin composition for IMC according to claim 1, wherein the radical scavenger (B) is a phenol-based antioxidant and / or an amine-based ultraviolet stabilizer.   6. The styrene rubber-containing resin composition for IMC according to any one of claims 1 to 5, wherein the radical curable inner coating composition contains an organic peroxide.   The styrenic rubber-containing resin composition according to any one of claims 1 to 6 is molded and coated by an in-mold coating method using a radical curable inner coating composition as a coating agent. Characteristic IMC molded product.

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