JP2011245633A - Multilayer molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer molded product formed by laminating a polycarbonate resin and a thermoplastic elastomer composition having excellent adhesion to the polycarbonate resin and having excellent sealing property, heat resistance, and oil resistance.SOLUTION: The multilayer molded product is formed by laminating a layer formed of the polycarbonate resin and a layer containing the thermoplastic elastomer composition including following components (A), (B), (C), and (D), the component (A) including an acrylic rubber formed by copolymerizing a monomer mixture including as a main ingredient at least one of an alkyl acrylate and an alkoxyalkyl acrylate and containing 0.5-15 mass% of an epoxy group-containing monomer, in an amount of 50-85 pts.mass based on 100 pts.mass of the components (A) and (B) in total; the component (B) including a thermoplastic polyester resin in an amount of 15-50 pts.mass based on 100 pts.mass of the ingredients (A) and (B) in total; the component (C) including a graft copolymer or a precursor thereof in an amount of 1-35 pts.mass based on 100 pts.mass of the ingredients (A) and (B) in total; and the component (D) including a plasticizer in an amount of 60 pts.mass or less based on 100 pts.mass of the ingredients (A).

Description

  The present invention relates to a multilayer molded article formed by laminating a layer made of a polycarbonate resin and a layer containing a thermoplastic elastomer composition excellent in sealing properties, heat resistance and oil resistance.

  Conventionally, automotive window frames, building material window frames, home appliances, mobile phones, various information devices, ink tanks, fuel tanks, various containers and other parts that require sealability, automotive interior parts, tools, sundries, writing instruments, etc. In parts requiring grip properties, a multilayer molded body of hard resin and soft resin may be used. Particularly in the automotive field, a multilayer molded body of a hard resin such as polycarbonate resin and acrylic resin called glazing and a soft resin such as thermoplastic elastomer can be used. As a method for easily producing such a multilayer molded body, a method of bonding by heating such as a multicolor injection molding method, an insert injection molding method, a co-extrusion molding method or the like is known.

  A soft resin is melt-kneaded with an acrylic rubber excellent in sealing properties, heat resistance and oil resistance, a graft copolymer composed of an olefin polymer segment and a vinyl polymer segment, a crosslinking agent, and a co-crosslinking agent. The resulting olefinic thermoplastic elastomer (see Patent Document 1) is useful, but is incompatible with the polycarbonate resin and has no adhesion, so the above production method cannot be applied. When manufacturing a body, there existed a problem that the process of apply | coating an adhesive agent etc. on the resin surface and making it adhere | attach was needed.

JP 2004-002651 A

  Accordingly, an object of the present invention is to provide a multilayer resin laminate comprising a polycarbonate resin and a thermoplastic elastomer composition having excellent adhesion to the polycarbonate resin and excellent in sealing properties, heat resistance and oil resistance. The object is to provide a molded body.

  In order to achieve the above object, the multilayer molded article of the first invention in the present invention comprises a layer comprising a polycarbonate resin, the following components (A), (B), (C) and (D): A layer containing a thermoplastic elastomer composition made of is laminated.

Component (A): A monomer mixture containing at least one of alkyl acrylate ester and alkoxyalkyl acrylate ester as a main component and containing 0.5 to 15% by mass of an epoxy group-containing monomer is copolymerized. 50 to 85 parts by mass in 100 parts by mass of the total of component (A) and component (B).
Component (B): 15 to 50 parts by mass of the thermoplastic polyester resin in a total of 100 parts by mass of the component (A) and the component (B).
Component (C): an olefin polymer segment formed from ethylene and a polar monomer, and a vinyl copolymer segment formed from a vinyl monomer containing at least an alkyl acrylate, The graft copolymer in which the segment forms a dispersed phase in the matrix phase formed by the other segment or its precursor is 1 to 35 with respect to 100 parts by mass in total of the component (A) and the component (B). Parts by mass.
Component (D): The plasticizer is 60 parts by mass or less with respect to 100 parts by mass of the component (A).

  The multilayer molded body of the second invention is characterized in that, in the first invention, the component (D) is selected from trimellitic acid plasticizers, polyester plasticizers, and polyetherester plasticizers. .

  The multilayer molded body of the third invention is the thermoplastic elastomer composition comprising the component (A), the component (B), the component (C) and the component (D) in either the first or second invention, It is obtained by dynamically crosslinking with 0.05 to 5 parts by mass of a crosslinking agent (component (E)) with respect to 100 parts by mass of the component (A).

  In the multilayer molded body of the present invention, the polycarbonate resin and the thermoplastic elastomer composition have good adhesiveness, and by a molding method using adhesion by heating such as multicolor injection molding, insert injection molding, coextrusion molding, etc. It can be easily manufactured without using an adhesive. Furthermore, the thermoplastic elastomer composition is excellent in sealing properties, heat resistance and oil resistance. For this reason, it is useful for automobile interior / exterior use, building material use, home appliance use, mobile phone use, various information equipment use, and the like.

The multilayer molded body of this embodiment comprises a layer made of a polycarbonate resin, an acrylic rubber as component (A), a thermoplastic polyester resin as component (B), a graft copolymer as component (C), or a precursor and components thereof ( It is obtained by laminating layers containing a thermoplastic elastomer composition comprising the plasticizer of D).
Hereinafter, each component of the multilayer molded body will be described in detail.
[Polycarbonate resin]
Polycarbonate resin is transparent, impact resistant,
1274675862000_0
It is a kind of engineering plastics excellent in that all commercially available polycarbonate resins can be used. In addition to the polycarbonate resin, a plasticizer, a filler, an antioxidant, an ultraviolet absorber, a light stabilizer, a flame retardant, a colorant, a processing aid, an antistatic agent, and the like can be added as necessary.

[Component (A) Acrylic rubber]
The acrylic rubber of component (A) is a component that can exhibit the sealing properties, heat resistance, and oil resistance of the thermoplastic elastomer composition. The acrylic rubber is obtained by copolymerizing a monomer mixture containing at least one of alkyl acrylate ester and alkoxyalkyl acrylate ester as a main component and containing 0.5 to 15% by mass of an epoxy group-containing monomer. It is obtained.

As alkyl acrylates, methyl acrylate, ethyl acrylate, acrylic acid-n-propyl, isopropyl acrylate, acrylic acid-n-butyl, acrylic acid isobutyl, acrylic acid-tert-butyl, acrylic acid-n-pentyl -N-hexyl acrylate, n-heptyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, dodecyl acrylate, and the like. Among these, an alkyl acrylate ester having 2 to 4 carbon atoms in the alkyl group is particularly preferable in that it can exhibit excellent sealing properties and oil resistance.
Examples of the alkoxyalkyl acrylate include an alkoxyalkyl acrylate having an alkyl group having 2 to 4 carbon atoms, such as 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, and 2-butoxyethyl acrylate. Can be mentioned. Among these, 2-methoxyethyl acrylate is particularly preferable in that it can exhibit excellent oil resistance. One or more of these monomers are appropriately selected and used.

The content of at least one of the acrylic acid alkyl ester and the acrylic acid alkoxyalkyl ester contained in the acrylic rubber is preferably 85 to 99.5% by mass. When this content is less than 85% by mass, the physical properties such as the sealing properties of the thermoplastic elastomer composition deteriorate, and when it exceeds 99.5% by mass, the content of the epoxy group-containing monomer is relatively high. Tends to be reduced and the acrylic rubber is not sufficiently crosslinked.
The epoxy group-containing monomer means a vinyl monomer having an epoxy group in the molecule. As this epoxy group-containing monomer, all general epoxy group-containing monomers can be used. Examples thereof include glycidyl acrylate, glycidyl methacrylate, vinyl glycidyl ether, allyl glycidyl ether, and the like. A preferred epoxy group-containing monomer is glycidyl (meth) acrylate. In this specification, acrylic and methacryl are collectively referred to as (meth) acrylic. The content of the epoxy group-containing monomer copolymerized in the acrylic rubber is 0.5 to 15% by mass, preferably 1 to 10% by mass. When the content of the epoxy group-containing monomer is less than 0.5% by mass, the acrylic rubber is not sufficiently crosslinked, and the mechanical strength of the thermoplastic elastomer composition is inferior, and when the content exceeds 15% by mass. Since the acrylic rubber is excessively crosslinked, the molding processability of the thermoplastic elastomer composition is lowered, and a good appearance cannot be obtained.

  Also, for the purpose of improving physical properties such as sealing properties, molding processability, oil resistance, etc., methacrylic acid alkyl esters such as methyl methacrylate and ethyl methacrylate; 2-methoxyethyl methacrylate, 2-ethoxyethyl methacrylate, etc. (Meth) acrylic acid, crotonic acid, maleic acid and other carboxyl group-containing monomers; (meth) acrylic acid-2-hydroxyethyl, (meth) acrylic acid-2-hydroxypropyl, etc. Hydroxyl group-containing monomers; active chlorine-containing monomers such as 2-chloroethyl vinyl ether, vinyl monochloroacetate and allyl chloroacetate; trifluoromethyl methyl (meth) acrylate, 2-trifluoromethyl (meth) acrylate Fluorine (meth) acrylic acid ester such as ethyl; Aromatic vinyl compounds such as ethylene and α-methyl styrene; vinyl nitriles such as acrylonitrile and methacrylonitrile; vinyl amides such as acrylamide, methacrylamide and N-methylol acrylamide; α-olefins such as ethylene, propylene and isobutene; butadiene, Conjugated dienes such as isoprene and chloroprene; bifunctional (meth) acrylates, trifunctional (meth) acrylates and copolymerizable monomers such as vinyl acetate and vinyl chloride can be copolymerized in acrylic rubber. it can.

The copolymerization amount of these copolymerizable monomers is preferably 40% by mass or less, and more preferably 30% by mass or less. When the copolymerization amount exceeds 40% by mass, the balance of physical properties such as sealing properties, molding processability, oil resistance, and low temperature properties of the thermoplastic elastomer may be impaired.
The glass transition temperature (Tg) of the acrylic rubber of component (A) is preferably −15 ° C. or lower, more preferably −20 ° C. or lower. When Tg is higher than −15 ° C., the embrittlement temperature of the thermoplastic elastomer composition becomes high, so that it may not be able to withstand practical use.
The content of the acrylic rubber of component (A) contained in the thermoplastic elastomer composition of the present invention is 50 to 85 parts by mass when the total amount of component (A) and component (B) is 100 parts by mass. It is preferable because it is excellent in the balance between molding processability and sealability. When the content of the acrylic rubber is less than 50 parts by mass, the sealing performance of the thermoplastic elastomer composition is impaired, which is not preferable. When the content exceeds 85 parts by mass, the molding processability of the thermoplastic elastomer composition is impaired. .

[Component (B) Thermoplastic polyester resin]
The thermoplastic polyester resin of component (B) is a component that improves the molding processability of the thermoplastic elastomer composition of the present invention and exhibits heat resistance and oil resistance. Such thermoplastic polyester resins include all thermoplastic saturated polyesters having an ester bond in the main chain. The thermoplastic polyester resin can be obtained by a known method such as polycondensation of a dicarboxylic acid component and a dihydroxy component, polycondensation of an oxycarboxylic acid component, or polycondensation of these three components. It may be. The thermoplastic polyester resin is used alone or in combination of two or more.

The thermoplastic polyester resin may be non-crystalline, but is preferably crystalline because it is excellent in heat resistance and oil resistance. Moreover, it is preferable that melting | fusing point is 100 degreeC or more, and it is most preferable that it exists between 160-280 degreeC at the point which is excellent in the heat resistance and oil resistance in high temperature. Preferable examples of the thermoplastic polyester resin include polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate and polybutylene naphthalate.
The content of the thermoplastic polyester resin of the component (B) contained in the thermoplastic elastomer composition is 15 to 50 parts by mass when the total amount of the component (A) and the component (B) is 100 parts by mass. And, it is preferable because of its excellent balance between moldability and sealability. When the content of the thermoplastic polyester resin is less than 15 parts by mass, the molding processability of the thermoplastic elastomer composition is impaired. When it exceeds 50 parts by mass, the sealing property of the thermoplastic elastomer composition is impaired. It is not preferable.

[Component (C) Graft copolymer]
The graft copolymer of component (C) increases the compatibility (affinity) of the component (A) acrylic rubber and component (B) thermoplastic polyester resin, and the function of component (A) and component (B). It is a component that fully exerts its function and exhibits a synergistic effect. With this graft copolymer, good moldability can be imparted while maintaining the sealing property of the thermoplastic elastomer composition. The graft copolymer is composed of an olefin polymer segment formed from ethylene and a polar monomer, and a vinyl copolymer segment formed from a vinyl monomer containing at least an alkyl acrylate ester, A graft copolymer in which one segment forms a dispersed phase in a matrix phase formed by the other segment.

  The olefin polymer segment is formed from ethylene and a polar monomer, and specific examples thereof include ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-glycidyl methacrylate copolymer, ethylene-acetic acid. Vinyl-maleic anhydride copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid-n-butyl copolymer, ethylene-methyl acrylate-glycidyl methacrylate copolymer Polymer, ethylene-ethyl acrylate-glycidyl methacrylate copolymer, ethylene-glycidyl methacrylate copolymer, maleic anhydride modified ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-methacrylic acid Dimethylaminomethyl copolymer, ethylene-vinyl Of ethylene glycol adduct, ethylene-vinyl alcohol copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-acrylic acid copolymer or ethylene-methacrylic acid copolymer Examples include ionomers in which molecules are intermolecularly bonded with metal ions such as sodium and zinc.

The proportion of the polar monomer in the olefin polymer segment is preferably 5 to 50 parts by mass and more preferably 10 to 40 parts by mass with respect to 100 parts by mass in total of ethylene and polar monomer. A copolymer having a polar monomer ratio of less than 5 parts by mass has high hardness and low oil resistance, and thus may impair the sealing properties and oil resistance of the thermoplastic elastomer composition. On the other hand, a copolymer with more than 50 parts by weight of polar monomer is excellent in low hardness and oil resistance, but poor in mechanical strength. Therefore, mechanical properties such as tensile strength and elongation of the thermoplastic elastomer composition are poor. descend.
The vinyl copolymer segment is formed from a vinyl monomer containing at least an alkyl acrylate ester. By being compatible with the acrylic rubber of component (A), the vinyl copolymer segment can improve the molding processability and appearance of the thermoplastic elastomer composition, and can further improve the mechanical properties.

As alkyl acrylates, methyl acrylate, ethyl acrylate, acrylic acid-n-propyl, isopropyl acrylate, acrylic acid-n-butyl, acrylic acid isobutyl, acrylic acid-tert-butyl, acrylic acid-n-pentyl -N-hexyl acrylate, n-heptyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, dodecyl acrylate, and the like. Among these, an acrylic group having 2 to 4 carbon atoms of an alkyl group such as ethyl acrylate and acrylic acid-n-butyl is particularly preferable in terms of oil resistance and compatibility with the acrylic rubber of component (A). Acid alkyl ester.
The acrylic acid alkyl ester contained in 100 parts by mass of the vinyl copolymer segment is preferably 20 parts by mass or more, and more preferably 30 parts by mass or more. When the acrylic acid alkyl ester is less than 20 parts by mass, the compatibility between the graft copolymer and the acrylic rubber cannot be sufficiently obtained, so that the mechanical strength of the thermoplastic elastomer composition is deteriorated and the appearance is deteriorated. Absent.

  The vinyl copolymer segment can be copolymerized with one or more vinyl monomers in addition to the alkyl acrylate ester. Examples of copolymerizable vinyl monomers include, for example, methacrylic acid alkyl esters such as methyl methacrylate and ethyl methacrylate; (meth) acrylic acid-2-methoxyethyl; (meth) acrylic acid-2-ethoxyethyl Epoxy group-containing monomers such as (meth) acrylic acid alkoxyesters, glycidyl (meth) acrylate, vinyl glycidyl ether, allyl glycidyl ether, etc .; carboxyl groups such as (meth) acrylic acid, crotonic acid, maleic acid, etc. Monomer; hydroxyl group-containing monomer such as (meth) acrylic acid-2-hydroxyethyl, (meth) acrylic acid-2-hydroxypropyl, etc .; styrene, methylstyrene, dimethylstyrene, ethylstyrene, isopropylstyrene, Aromatic vinyl compounds such as chlorostyrene; α-methyl Styrene, alpha-substituted styrenes such as alpha-ethyl styrene; acrylonitrile, vinyl nitriles such as methacrylonitrile, and the like. These vinyl monomers can be copolymerized preferably in an amount of 80 parts by mass or less, more preferably 70 parts by mass or less in 100 parts by mass of the vinyl copolymer segment.

The number average degree of polymerization of the vinyl copolymer to be the vinyl copolymer segment is usually 5 to 10,000, preferably 10 to 5,000, and most preferably 100 to 2,000. If the number average degree of polymerization is less than 5, it is possible to improve the moldability of the thermoplastic elastomer composition, but the compatibility with the component (A) acrylic rubber is reduced, and the thermoplastic elastomer composition Mechanical properties and appearance tend to deteriorate. On the other hand, when the number average degree of polymerization exceeds 10,000, the melt viscosity increases and the molding processability of the thermoplastic elastomer composition decreases.
The proportion of the olefin polymer segment contained in 100 parts by mass of the graft copolymer is usually 5 to 95 parts by mass, preferably 20 to 90 parts by mass, and most preferably 30 to 85 parts by mass. Therefore, the proportion of the vinyl copolymer segment is usually 5 to 95 parts by mass, preferably 10 to 80 parts by mass, and most preferably 15 to 70 parts by mass. When the proportion of the olefin polymer segment is less than 5 parts by mass, the molding processability of the thermoplastic elastomer composition becomes insufficient, and when it exceeds 95 parts by mass, the compatibility with the acrylic rubber of component (A) is insufficient. The mechanical properties and appearance of the thermoplastic elastomer composition tend to deteriorate.

As described above, the graft copolymer is a multiphase structure in which one segment forms a dispersed phase in a matrix phase formed by the other segment. One segment forms a dispersed phase as fine particles having an average particle diameter of 0.001 to 10 μm in the other segment. In both cases where the average particle size of the dispersed phase is less than 0.001 μm and more than 10 μm, the compatibility between the graft copolymer of component (C) and the acrylic rubber of component (A) is low, and the thermoplastic elastomer The mechanical properties and appearance of the composition tend to deteriorate.
The grafting method for producing the graft copolymer may be any of generally known chain transfer methods, ionizing radiation irradiation methods, etc., but the method shown below is most preferred. The reason is that the production method is simple, the grafting efficiency is high, the secondary aggregation of the vinyl polymer segment due to heat does not occur, and the graft copolymer of component (C) is used as the acrylic rubber or component of component (A). It is because it becomes easy to mix with the thermoplastic polyester resin of (B).

  Below, the manufacturing method of such a graft copolymer is demonstrated. An olefin polymer formed from ethylene and a polar monomer suspended in water, a vinyl monomer containing a vinyl monomer having at least an alkyl acrylate ester, the following general formula (1) or The radically polymerizable organic peroxide represented by (2) is impregnated with one or a mixture of two or more and a radical polymerization initiator. Thereafter, the vinyl monomer and the radical polymerizable organic peroxide are copolymerized in an olefin polymer formed from ethylene and a polar monomer to obtain a grafted precursor. The graft copolymer can be obtained by melt-kneading this grafted precursor.

The grafting precursor is composed of an olefin polymer particle formed from ethylene and a polar monomer, a vinyl monomer containing a vinyl monomer having at least an alkyl acrylate ester, and a radical polymerizable organic oxidation. It is a structure in which a copolymer with a product is dispersed. In the grafting precursor, the copolymer of vinyl monomer and radical polymerizable organic peroxide dispersed therein contains 0.003 to 0.73% by mass as active oxygen. Is preferred. When the amount of active oxygen is less than 0.003% by mass, the grafting ability of the grafting precursor is extremely lowered, which is not preferable. On the other hand, if it exceeds 0.73 mass%, gel formation increases during grafting, which is not preferable. In this case, the amount of active oxygen can be obtained by extracting a vinyl copolymer from the grafted precursor by solvent extraction and determining the amount of active oxygen of the vinyl copolymer by iodometry.
The radical polymerizable organic peroxide is a monomer having an ethylenically unsaturated group and a peroxide bonding group. Preferably, it is a compound represented by the following general formula (1) or (2).

Wherein R1 is a hydrogen atom or an alkyl group having 1 or 2 carbon atoms, R2 is a hydrogen atom or a methyl group, R3 and R4 are each an alkyl group having 1 to 4 carbon atoms, and R5 is an alkyl group having 1 to 12 carbon atoms. A phenyl group, an alkyl-substituted phenyl group or a cycloalkyl group having 3 to 12 carbon atoms, m is 1 or 2.)

Wherein R6 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R7 is a hydrogen atom or a methyl group, R8 and R9 are each an alkyl group having 1 to 4 carbon atoms, and R10 is an alkyl group having 1 to 12 carbon atoms. , A phenyl group, an alkyl-substituted phenyl group or a cycloalkyl group having 3 to 12 carbon atoms, n is 0, 1 or 2.)

Examples of the radical polymerizable organic peroxide represented by the general formula (1) include tert-butylperoxyacryloyloxyethyl carbonate, tert-amylperoxyacryloyloxyethyl carbonate, tert-hexylperoxyacryloyloxyethyl carbonate, Examples include tert-butyl peroxymethacryloyloxyethyl carbonate, tert-amyl peroxymethacryloyloxyethyl carbonate, and tert-hexyl peroxymethacryloyloxyethyl carbonate.
Examples of the radical polymerizable organic peroxide represented by the general formula (2) include tert-butyl peroxyallyl carbonate, tert-amyl peroxyallyl carbonate, tert-hexyl peroxyallyl carbonate, tert-butyl peroxymethallyl carbonate, tert -Amyl peroxymethallyl carbonate, tert-hexyl peroxymethallyl carbonate, etc. are mentioned. Among these, tert-butyl peroxyacryloyloxyethyl carbonate, tert-butyl peroxymethacryloyloxyethyl carbonate, tert-butyl peroxyallyl carbonate or tert-butyl peroxymethallyl carbonate is preferable.

  The component (C) graft copolymer can be obtained by melt-kneading the grafting precursor. By heating during melt-kneading, the peroxide bond in the vinyl copolymer is cleaved, and the generated radical performs a hydrogen abstraction reaction on the olefin polymer, followed by the grafting reaction to produce the graft copolymer. Is done. Specifically, a Banbury mixer, a Brabender mixer, a pressure kneader, a single screw extruder, a twin screw extruder, a roll or the like is used as a kneader for melt kneading. The kneading temperature is usually in the range of 100 to 300 ° C, preferably 120 to 280 ° C. When the temperature is less than 100 ° C., melting may be incomplete or the melt viscosity may be too high, so mixing is insufficient and phase separation or delamination of the graft copolymer appears, which is not preferable. . On the other hand, when the temperature exceeds 300 ° C., decomposition or gelation tends to occur during grafting, which is not preferable.

In the graft copolymer of component (C) thus obtained, the olefin polymer segment is oriented to the thermoplastic polyester resin of component (B) (shows compatibility), and the vinyl polymer segment is the component. It is considered that (A) is oriented to the acrylic rubber (shows compatibility). And in a thermoplastic elastomer composition, a component (A) and a component (B) are compatibilized by the component (C), and the function of a component (A) and a component (B) is exhibited synergistically. Guessed.
The proportion of the graft copolymer of component (C) contained in the thermoplastic elastomer composition is 1 to 35 masses per 100 mass parts in total of the acrylic rubber of component (A) and the thermoplastic polyester resin of component (B). Part. When the proportion of the graft copolymer is less than 1 part by mass, the effect of improving the molding processability is insufficient and the appearance tends to be inferior, and when it exceeds 35 parts by mass, the oil resistance of the thermoplastic elastomer is impaired. It is not preferable.
[Component (D) Plasticizer]

  The thermoplastic elastomer composition may contain a plasticizer. Plasticizers include phthalic acid, adipic acid, azelaic acid, sebacic acid, phosphoric acid, trimellitic acid, pyromellitic acid, epoxy, polyester or polyether ester, or mixtures thereof. It can be included as a plasticizer. A specific advantage of including a plasticizer is that the processability, sealability, oil resistance and cold resistance of the thermoplastic elastomer composition are improved. On the other hand, when the heat resistance of the plasticizer is low or the volatility is high, the thermoplastic elastomer composition may be adversely affected. That is, deterioration of the thermoplastic elastomer composition due to decomposition of the plasticizer, curing or shrinkage of the thermoplastic elastomer composition due to volatilization of the plasticizer, and the like. When such a thermoplastic elastomer composition deteriorates, cures and shrinks, there arises a problem that the sealing property is lowered. Therefore, the plasticizer contained in the thermoplastic elastomer composition is preferably a plasticizer having high heat resistance and low volatility. Preferred plasticizers that can be used are trimellitic acid type, polyester type, and polyether ester type. Examples of trimellitic acid include trimellitic acid tri-2-ethylhexyl, trimellitic acid tri-n-octyl, trimellitic acid triisononyl, trimellitic acid triisodecyl, and the like. Examples of polyesters include phthalic acid polyesters, adipic acid polyesters, sebacic acid polyesters, trimellitic acid polyesters, and pyromellitic acid polyesters. Examples of the polyether ester type include polyether polyester type. These plasticizers can be used alone or in combination of two or more.

It is preferable that the compounding quantity of a plasticizer is 60 mass parts or less with respect to 100 mass parts of acrylic rubber of a component (A). When the blending amount of the plasticizer exceeds 60 parts by mass, the plasticizer bleeds out, and the appearance of the thermoplastic elastomer composition tends to deteriorate and the mechanical properties tend to decrease.
Furthermore, the multilayer molded body of the present embodiment comprises a thermoplastic elastomer composition comprising the component (A), the component (B), the component (C) and the component (D) with respect to 100 parts by mass of the component (A). It is obtained by molding a thermoplastic elastomer composition obtained by dynamic crosslinking with 0.05 to 5 parts by mass of a crosslinking agent (component (E)).
Hereinafter, the component (E) of the thermoplastic elastomer composition will be described in detail.

[Component (E) Cross-linking agent]
The cross-linking agent used for obtaining the thermoplastic elastomer composition has a function of cross-linking the acrylic rubber by covalently bonding with the epoxy group of the acrylic rubber. As such a crosslinking agent, any crosslinking agent having a functional group that reacts with an epoxy group can be used. For example, polyamine, polyol, polycarboxylic acid, acid anhydride, organic carboxylic acid ammonium salt, dithiocarbamate, block carboxylic acid and the like can be mentioned, among which polycarboxylic acid and acid anhydride are particularly preferable. .

Specific examples of the polycarboxylic acid include succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, octadecanedicarboxylic acid, dodecenylsuccinic acid, butanetetracarboxylic acid, cyclopentanedicarboxylic acid, cyclopentanetricarboxylic acid, Examples include cyclopentanetetracarboxylic acid, cyclohexanedicarboxylic acid, cyclohexanetricarboxylic acid, phthalic acid, trimetic acid, trimesic acid, and pyromellitic acid. Specific examples of the acid anhydride include acid anhydrides of these polycarboxylic acids.
Although the usage-amount of a crosslinking agent changes with kinds of selected crosslinking agent, generally it is set in 0.05-5 mass parts with respect to 100 mass parts of acrylic rubber of a component (A). When the amount of the crosslinking agent used is less than 0.05 parts by mass, sufficient crosslinking is not performed, and the mechanical properties and oil resistance of the thermoplastic elastomer composition are deteriorated. When the amount exceeds 5 parts by mass, the thermoplastic elastomer composition Since the product is excessively cross-linked, good moldability cannot be obtained.

[Other ingredients]
In the thermoplastic elastomer composition, various additives other than the above components can be contained in suitable amounts. Such additives include, for example, phenolic and amine antioxidants, hindered amine light stabilizers, UV absorbers, acrylic polymer processing aids, stearic acid, zinc stearate, waxes, low Examples thereof include processing aids such as molecular weight polyethylenes, foaming agents, tackifiers, tackifiers, antistatic agents, colorants such as titanium dioxide, and pigments. It is preferable that the compounding quantity of an additive is 10 mass parts or less with respect to 100 mass parts of thermoplastic elastomer compositions, respectively. Moreover, fillers represented by carbon black, white carbon, clay, mica, calcium carbonate, talc and the like can be mentioned. The surface of the filler may be subjected to a surface treatment using stearic acid, oleic acid, palmitic acid or a metal salt thereof, paraffin wax, polyethylene wax or a modified product thereof, organic silane, organic borane, organic titanate, etc. preferable. Examples of the flame retardant include inorganic flame retardants represented by magnesium hydroxide and aluminum hydroxide, and organic flame retardants represented by halogen and phosphorus. The blending amount of the filler and the flame retardant is preferably 70 parts by mass or less with respect to 100 parts by mass of the thermoplastic elastomer composition.

[Thermoplastic elastomer composition]
The thermoplastic elastomer composition is produced by melt-kneading the composition comprising the above components. As an apparatus for performing melt kneading, a Banbury mixer, a Brabender mixer, a pressure kneader, a single screw extruder, a twin screw extruder, a roll, or the like can be used. In addition, the dynamic crosslinking by addition of a crosslinking agent is performed by using an acrylic rubber as component (A), a thermoplastic polyester resin as component (B), a graft copolymer as component (C), and a plasticizer as component (D) as thermoplastic. It means melt-kneading at a temperature higher than the melting point of the polyester resin, and crosslinking the epoxy groups of the acrylic rubber under high shear during the kneading. Usually, the acrylic rubber thus dynamically crosslinked is finely dispersed in the matrix phase of the thermoplastic polyester resin. By forming such a phase structure, the elastomer composition has thermoplasticity although the acrylic rubber is crosslinked. Therefore, the thermoplastic elastomer composition can be processed and reprocessed by a conventional thermoplastic resin molding method (processing technique) such as an injection molding method, an extrusion molding method and the like and a molding apparatus.

  When producing a thermoplastic elastomer composition, not a graft copolymer but a grafted precursor can be used as a material. This is because the grafting precursor undergoes a grafting reaction by melt kneading in the process of producing the thermoplastic elastomer composition, and becomes a graft copolymer. That is, the grafting reaction step and the dynamic crosslinking step can be performed simultaneously by using the grafting precursor. Thus, the method of manufacturing a thermoplastic elastomer composition using a grafting precursor is preferable from the viewpoint of simplification of the manufacturing process.

  The crosslinking reaction proceeds by adding a crosslinking agent of component (E) during melt kneading. The crosslinking agent of component (E) is together with acrylic rubber of component (A), thermoplastic polyester resin of component (B), graft copolymer or grafting precursor of component (C) and plasticizer of component (D). It is possible to carry out dynamic crosslinking by simultaneously charging the kneader. In many cases, acrylic rubber, thermoplastic polyester resin, graft copolymer or grafting precursor and plasticizer are put into a kneading machine, and after sufficient melting and kneading, a cross-linking agent is added to perform dynamic crosslinking. It is more effective to do it. However, when using a crosslinking agent having a slow reaction rate or a slow-acting crosslinking agent, the crosslinking agent should be added before the acrylic rubber, thermoplastic polyester resin, and graft copolymer are sufficiently melted and kneaded. Can do. When the crosslinking reaction is started by adding a crosslinking agent, the viscosity of the composition increases, and when the viscosity becomes constant, the crosslinking reaction is completed. There are various changes in the viscosity until reaching a constant value. For example, there are cases where the viscosity decreases and reaches a constant value after reaching the maximum value of the viscosity, and continues to increase and reaches a constant value.

In general, it is preferred that the various additives be thoroughly mixed (blended) in the composition before the cross-linking agent is added. This is because even if various additives are added during the crosslinking reaction or after the reaction is completed, they are often not sufficiently dispersed in the composition. Therefore, it is preferable to add various additives from the beginning or middle of the kneading and add the crosslinking agent after sufficiently mixing in the composition.
The temperature at which melting, mixing and dynamic crosslinking are performed is suitably in the range of 100 to 350 ° C. corresponding to the melting start temperature of the acrylic rubber from the melting point of the thermoplastic polyester resin. This temperature is more preferably 150 to 300 ° C, particularly preferably 180 to 280 ° C.

(Multilayer molded product)
The method for producing the multilayer molded body of the present embodiment is not particularly limited, and a generally used molding method can be used according to the shape and application of the molded body. For example, a multicolor injection molding method, an insert injection molding method, a coextrusion molding method, a press molding method, a blow molding method, a calendar molding method, and the like can be given.
As a specific example of the multilayer molded body produced in this way, in the automotive industry, a gasket made of the thermoplastic elastomer composition of the present invention is heated and bonded to the peripheral part of a plate-shaped body made of polycarbonate resin called glazing. Is mentioned.

  Hereinafter, although the embodiment will be described more specifically with reference to examples and comparative examples, the present invention is not limited thereto. Synthesis examples of materials used in each example and comparative example are shown below.

[Synthesis Example 1, Production of Acrylic Rubber (A-1)]
A flask equipped with a stirrer, thermometer, cooler, dripping device, nitrogen gas inlet tube, ion exchange water 1000 g, sodium dodecyl sulfate 10 g, sodium hydrogen sulfite 0.5 g, ferrous sulfate 0.005 g, ethylenediaminetetraacetate sodium 0 Then, the temperature was raised to 30 ° C. with stirring while blowing nitrogen gas. Thereafter, 5 g of ammonium persulfate was added as a polymerization initiator, and a monomer mixture (250 g of ethyl acrylate, 100 g of n-butyl acrylate, 130 g of 2-methoxyethyl acrylate, 20 g of glycidyl methacrylate (GMA)) was added thereto. ) After adding 500 g dropwise over 3 hours, polymerization was further performed for 3 hours to obtain an emulsion. Next, salting out was performed by dripping this emulsion into 0.5 mass% calcium chloride aqueous solution over 1 hour. And after fully washing with water, it dried at 80 degreeC and obtained the acrylic rubber (A-1) containing 4 mass parts of GMA. The acrylic rubber (A-1) had a Tg of -25 ° C.

[Synthesis Example 2, Production of Acrylic Rubber (A-2)]
In the same manner as in Synthesis Example 1 except that the composition of the monomer mixture was changed to 268.5 g of ethyl acrylate, 100 g of acrylic acid-n-butyl, 130 g of 2-methoxyethyl acrylate, and 1.5 g of GMA, An acrylic rubber (A-2) containing 0.3 part by mass was produced. The acrylic rubber (A-2) had a Tg of −28 ° C.
Table 1 shows the amount of each component of the synthesized acrylic rubber.

[Synthesis Example 3, Production of Grafting Precursor (C-1)]
In a 5-liter stainless steel autoclave, 2000 g of pure water and 2.5 g of polyvinyl alcohol as a suspending agent were dissolved. In this, 700 g of ethylene-glycidyl methacrylate copolymer (LOTADER 8840, 8 parts by mass of glycidyl methacrylate, manufactured by ARKEMA Co., Ltd.) was added and stirred and dispersed. As a polymerization initiator, 2 g of benzoyl peroxide (manufactured by NOF Corporation, Nyper BW), 6 g of tert-butylperoxymethacryloyloxyethyl carbonate, vinyl monomer mixture (acrylic acid-n-butyl 150 g, methacrylic acid) A mixed monomer consisting of 300 g of 2-hydroxypropyl 150 g) was charged into the autoclave. Subsequently, the autoclave is heated to 60 to 65 ° C. and stirred for 2 hours to impregnate the ethylene-glycidyl methacrylate copolymer with the polymerization initiator, the radical polymerizable organic peroxide and the vinyl monomer. It was. Next, the temperature was raised to 80 to 85 ° C. and maintained at that temperature for 6 hours to complete the polymerization, and then washed with water and dried to obtain a grafted precursor (C-1). When this grafted precursor (C-1) was observed with a scanning electron microscope (manufactured by Hitachi, Ltd.), a multiphase structure in which a true spherical resin having an average particle size of 0.3 to 0.5 μm was uniformly dispersed. It was a body.

[Synthesis Example 4, Production of Graft Copolymer (C-2)]
Grafting precursor in the same manner as in Synthesis Example 3, except that 8 g of tert-butylperoxymethacryloyloxyethyl carbonate and the composition of the vinyl monomer mixture were changed to 150 g of 2-hydroxypropyl methacrylate and 150 g of styrene. Got. The obtained grafting precursor was extruded at 180 ° C. and a rotation speed of 100 rpm by a Laboplast mill single screw extruder (Toyo Seiki Seisakusho Co., Ltd.) to cause a grafting reaction, whereby a graft copolymer (C-2) was obtained. Got. This graft copolymer was a multiphase structure in which a true spherical resin having an average particle size of 0.3 to 0.5 μm was uniformly dispersed.

Table 2 shows the amount of each component of the synthesized grafting precursor and graft copolymer.
As other materials, commercially available products described below were used.
Polycarbonate resin: Lexan 341R (SABIC Innovative Plastics)
Thermoplastic polyester resin: DURANEX 300FP (polybutylene terephthalate, melting point 225 ° C., manufactured by Wintech Polymer Co., Ltd.)
Plasticizer: Polysizer W230H (Adipic acid polyester, manufactured by DIC Corporation)
Antioxidant: Irganox 1010 (hindered phenol-based antioxidant, manufactured by Ciba Specialty Chemicals), NOCRACK CD (amine-based antioxidant, manufactured by Ouchi Shinsei Chemical Co., Ltd.)
Cross-linking agent: Ricacid BT-W (butanetetracarboxylic acid, manufactured by Shin Nippon Rika Co., Ltd.)

[Evaluation]
Evaluation of the thermoplastic elastomer composition shown in the present Example was performed by the method shown below.
(hardness)
In accordance with JIS K 6253, the hardness was measured by a spring hardness tester A type. The test piece was created with a heating press at 260 ° C.
(Compression set)
According to JIS K 6262, compression set (%) after 72 hours at a temperature of 120 ° C. was measured at a compression rate of 25%. The test piece was created with a heating press at 260 ° C.
(Oil resistance)
Based on JISK6258, the mass change rate (%) after being immersed in IRM903 oil at 150 degreeC for 1000 hours was measured. The test piece was created with a heating press at 260 ° C.

(Adhesive strength)
In order to obtain a multilayer molded body with an injection molding machine, a polycarbonate resin molded body (thickness: 1 mm) is set in advance in a mold (mold temperature: 50 ° C.), and then the heat of each example and comparative example is obtained. A multilayer molded body (thickness: 2 mm) with the plastic elastomer composition was prepared. A test sample (base material: 15 mm, adhesive surface: 15 mm × 100 mm) was cut out from the multilayer molded body, and the adhesive strength was measured using an autograph (Shimadzu Corporation). The test speed was 200 mm / min, and the peeling surface (angle) was measured at 90 °.
[Example 1]

70 parts by mass of acrylic rubber A-1 of Synthesis Example 1, 30 parts by mass of Duranex 300FP, 5 parts by mass of grafting precursor C-1 of Synthesis Example 3, 24 parts by mass of Polycizer W230H, and 0 of Irganox 1010 .5 parts by mass and Nocrack CD were charged at a rate of 1 part by mass into a pressure kneader heated to 260 ° C. Then, melt kneading was performed at a rotational speed of 32 rpm. All materials were melted and kneaded until the torque showed a constant value by mixing uniformly. When the torque became constant, 0.3 parts by mass of Ricacid BT-W was added as a crosslinking agent, and kneading was continued. It was observed that the torque increased immediately after the cross-linking agent was added, and the kneading was terminated when the torque reached a constant value.
The obtained thermoplastic elastomer composition was discharged from the kneader, put into a kneader ruder, extruded into a strand at 240 ° C., cooled and cut to obtain pellets of the thermoplastic elastomer composition. The various evaluations described above were carried out using this.

[Examples 2 and 3]
A thermoplastic elastomer composition was produced in the same manner as in Example 1 at the blending ratio shown in Table 3. Table 3 shows the blending ratio of each component and the results of various evaluations.
[Comparative Examples 1-3]
A thermoplastic elastomer composition was produced in the same manner as in Example 1 at the blending ratio shown in Table 3. Table 3 shows the blending ratio of each component and the results of various evaluations.

(Summary)

As shown in Table 3, it was found that when the thermoplastic elastomer composition was multilayer molded on a molded article of polycarbonate resin, it was excellent in adhesiveness with the polycarbonate resin. Furthermore, since the layer which consists of a thermoplastic elastomer composition has favorable compression set, it turned out that the multilayer molded object which is excellent in sealing performance and excellent in heat resistance and oil resistance is obtained (Example 1). To Example 3).
When the blending amount of the grafting precursor was excessive (Comparative Example 1), the adhesion with the polycarbonate resin was lowered, and the oil resistance was also lowered.
When the blending amount of the thermoplastic polyester resin was excessive (Comparative Example 2), the compression set was deteriorated and the sealing property was lowered.
When the blending amount of the acrylic rubber was excessive (Comparative Example 3), the injection moldability deteriorated and a multilayer molded body could not be produced.

Claims (3)

A multilayer molded article obtained by laminating a layer comprising a polycarbonate resin and a layer containing a thermoplastic elastomer composition comprising the following components (A), (B), (C) and (D).
Component (A): A monomer mixture containing at least one of alkyl acrylate ester and alkoxyalkyl acrylate ester as a main component and containing 0.5 to 15% by mass of an epoxy group-containing monomer is copolymerized. 50 to 85 parts by mass in 100 parts by mass of the total of component (A) and component (B).
Component (B): 15 to 50 parts by mass of the thermoplastic polyester resin in a total of 100 parts by mass of the component (A) and the component (B).
Component (C): an olefin polymer segment formed from ethylene and a polar monomer, and a vinyl copolymer segment formed from a vinyl monomer containing at least an alkyl acrylate, The graft copolymer in which the segment forms a dispersed phase in the matrix phase formed by the other segment or its precursor is 1 to 35 with respect to 100 parts by mass in total of the component (A) and the component (B). Parts by mass.
Component (D): The plasticizer is 60 parts by mass or less with respect to 100 parts by mass of the component (A). The multilayer molded article according to claim 1, wherein the component (D) is selected from trimellitic acid plasticizers, polyester plasticizers, and polyether ester plasticizers. The thermoplastic elastomer composition comprising the component (A), the component (B), the component (C), and the component (D) is crosslinked by 0.05 to 5 parts by mass with respect to 100 parts by mass of the component (A). The multilayer molded article according to claim 1, wherein the multilayer molded article is obtained by dynamic crosslinking with an agent (component (E)).