JP6506998B2 - Thermoplastic elastomer composition - Google Patents

Description

  The present invention relates to a thermoplastic elastomer composition used for parts for electric and electronic parts, parts for automobiles, sealing materials, packings, damping members, tubes and the like, and a molded article obtained by heat-molding the thermoplastic elastomer composition. . More particularly, the present invention relates to a thermoplastic elastomer composition suitable for sealing of automobile engine peripherals and high temperature devices particularly required for heat resistance, packings, tubes and the like, and a molded article obtained using the thermoplastic elastomer composition.

  In Patent Document 1, as a thermoplastic elastomer composition excellent in heat resistance, mechanical strength and flexibility, the dicarboxylic acid component is terephthalic acid or an ester-forming derivative thereof (a1), isophthalic acid or naphthalene-2 , 6-dicarboxylic acid, dimer acid and at least one dicarboxylic acid or ester forming derivative thereof (a2), and the molar ratio of (a2) to (a1) ((a1) / (a2)) High melting crystalline polymer segment (a3) and an aliphatic polyether unit and / or an aliphatic polyester unit, each of which comprises a crystalline aromatic polyester unit formed from a diol or an ester-forming derivative thereof, Polyester block copolymer (A) comprising a low melting point polymer segment (a4) consisting of A high melting point crystalline polymer segment (b1) comprising crystalline aromatic polyester units formed from terephthalic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof, an aliphatic polyether unit and / or an aliphatic A glycidyl group-modified polyolefin resin (C), a polyamide resin (a polyamide resin (C), and a thermoplastic elastomer composition containing a polyester block copolymer (B) having a low melting point polymer segment (b2) consisting of polyester units as a component A heat-resistant thermoplastic elastomer resin composition containing D) is disclosed.

In Patent Document 2, as a thermoplastic elastomer composition having excellent flexibility and compression set resistance, (a) a crystalline polymer having a density of 0.860 to 0.890 g / cm ³ and containing ethylene as a main component Olefin block copolymer comprising a block (hard segment) and an amorphous polymer block (soft segment) mainly composed of ethylene and at least one α-olefin selected from α-olefins having 3 to 30 carbon atoms A block copolymer consisting of 5 to 95 parts by mass of coalescence, and (b) at least two polymer blocks A mainly made of aromatic vinyl compounds, and at least one polymer block B mainly made of conjugated diene compounds And / or a block copolymer obtained by hydrogenating the same, and (d) further containing a softener for non-aromatic rubber. Thermoplastic elastomer compositions are disclosed.

  Patent Document 3 discloses (A) a thermoplastic copolyester elastomer or a thermoplastic copolyamide elastomer and (B) an epoxy group as a highly stressed thermoplastic elastomer composition which imparts flexibility and excellent heat resistance and compression set resistance. Containing (meth) acrylate copolymer rubber and component (B) are dispersed and dispersed by a compound having at least two carboxyl groups in the molecule and / or at least one carboxylic anhydride group in the molecule Thermoplastic elastomer compositions are disclosed.

JP, 2014-177566, A Unexamined-Japanese-Patent No. 2013-28653 Unexamined-Japanese-Patent No. 05-25374

However, since the thermoplastic elastomer composition described in Patent Document 1 is a polyester elastomer as a main component, although it is excellent in heat resistance and mechanical strength, its flexibility and compression set resistance are insufficient.
Moreover, although the thermoplastic elastomer composition described in Patent Document 2 is excellent in flexibility and compression set resistance at 70 to 100 ° C., since it is mainly composed of a styrene-based elastomer, it is resistant to higher temperatures. It has the disadvantages of compression set, heat aging resistance and mechanical strength.
Although the thermoplastic elastomer composition described in Patent Document 3 is excellent in heat resistance, its flexibility is insufficient, and it has a defect that when the rubber component is increased to impart flexibility, moldability is deteriorated.

  An object of the present invention is to provide a thermoplastic elastomer composition excellent in flexibility, compression set resistance at high temperature, mechanical strength and moldability, and a molded article obtained using the thermoplastic elastomer composition. It is.

The present invention
[1] Component A: (meth) acrylic rubber having an epoxy group
Component B: a polyester elastomer having a melting point of 160 to 300 ° C., and Component C: a metal of at least one organic acid selected from the group consisting of aliphatic organic acids having 4 to 30 carbon atoms, benzoic acid, and trimethylbenzoic acid a salt, metal components, and also contains sodium, calcium, zinc, and at least Tanedea Ru Yes hexane metal salt selected from the group consisting of aluminum,
The mass ratio of the component A to the component B (component A / component B) is 60/40 to 90/10, and the content of the component C with respect to a total of 100 parts by mass of the component A and the component B is the organic acid When the metal salt is a sodium salt, it is 0.05 to 0.4 parts by mass, when the metal salt of an organic acid is a calcium salt, it is 0.05 to 0.2 parts by mass, and when the metal salt of an organic acid is a zinc salt, 0.01 It consists of a thermoplastic elastomer composition which is 0.1 to 0.1 parts by mass and 0.05 to 0.2 parts by mass when the metal salt of an organic acid is an aluminum salt, and [2] the thermoplastic elastomer composition according to the above [1] , Relates to a molded body.

  The thermoplastic elastomer composition of the present invention has an effect of being excellent in flexibility, compression set resistance at high temperature, mechanical strength and moldability as a material of a molded body. Further, in the thermoplastic elastomer composition of the present invention, the polyester elastomer of Component B, wherein at least a predetermined amount of the (meth) acrylic monomer constituting the (meth) acrylic rubber having the epoxy group of Component A is ethyl acrylate. When it contains a soft segment consisting of a polyester type polymer block, it is further excellent in heat aging resistance.

  In the thermoplastic elastomer composition of the present invention (hereinafter, also referred to as the composition of the present invention), the epoxy group of component A reacts with the carboxyl group or hydroxyl group of the molecular terminal of component B at the time of melt kneading, A graft copolymer is formed in which the polyester elastomer is bonded. The graft copolymer portion functions as a compatibilizer that reinforces the interface between the component A and the component B, and the flexibility of the thermoplastic elastomer composition and the compression set at high temperatures (hereinafter referred to as "heat resistance" And mechanical strength is considered to be improved. Further, when 40 mol% or more of the (meth) acrylic monomer constituting the component A is ethyl acrylate and the soft segment constituting the component B is a polyester type polymer block, those having better heat aging resistance It becomes. Furthermore, since the composition of the present invention contains an organic acid metal salt, the melt flowability is enhanced and the moldability is improved without significantly affecting the mechanical strength.

  Component A (meth) acrylic rubber is composed of a (meth) acrylic monomer having no epoxy group and a (meth) acrylic monomer having an epoxy group, and in addition, (meth) acrylic monomer A monomer such as a vinyl monomer copolymerizable with the body may be included as long as the effect of the present invention is not impaired.

  As a (meth) acrylic monomer having no epoxy group, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylate 2-ethylhexyl, cyclohexyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate And phenoxyethyl (meth) acrylate etc., among which methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, hydroxyethyl acrylate, acrylic Acid hydroxypropyl, methoxyethyl acrylate, ethoxy acrylate Chill, butoxyethyl acrylate, and phenoxyethyl acrylate is preferable, and ethyl acrylate, butyl acrylate, and more preferably methoxyethyl acrylate, from the viewpoint of heat aging resistance, ethyl acrylate are more preferred. In the present specification, unless otherwise specified, alkyl group names without subscripts include isomers such as n-, iso-, sec-, tert- and the like, and when it is indicated as (meth) acrylic, methacrylic And both acrylic and acrylic.

  The content of ethyl acrylate is preferably 40 mol% or more, more preferably 45% of the (meth) acrylic monomer constituting the (meth) acrylic rubber having the epoxy group of the component A from the viewpoint of heat aging resistance. It is -99.5 mol%, more preferably 50 to 99 mol%.

  Examples of the (meth) acrylic monomer having an epoxy group include glycidyl (meth) acrylate and glycidyl ether of 4-hydroxybutyl (meth) acrylate.

  The content of the (meth) acrylic monomer having an epoxy group is preferably 0.5 mol% or more, more preferably 1 to 10 mol%, and still more preferably in all monomer units from the viewpoint of mechanical strength and heat resistance. Preferably, it is 1 to 5 mol%.

  From the viewpoint of oil resistance, the total content of the (meth) acrylic monomer having no epoxy group and the (meth) acrylic monomer having an epoxy group is, among all the monomer units constituting Component A, Preferably, it is 50 mol% or more, more preferably 80 mol% or more, further preferably 90 mol% or more, further preferably 95 mol% or more.

  Examples of vinyl monomers copolymerizable with (meth) acrylic monomers include styrene, α-methylstyrene, vinyl acetate, ethylene, propylene, butadiene, isoprene and acrylonitrile. Among these, styrene, Alpha-methylstyrene and ethylene are preferred.

  As a polymerization method of the monomer for obtaining (meth) acrylic rubber, a radical polymerization method, a living anion polymerization method, a living radical polymerization method, etc. are mentioned. Further, as a form of polymerization, a solution polymerization method, an emulsion polymerization method, a suspension polymerization method, a bulk polymerization method and the like can be mentioned.

  The glass transition temperature of the (meth) acrylic rubber is preferably -100 to 10 ° C, more preferably -90 to 5 ° C, and still more preferably -80 to 0 ° C from the viewpoint of flexibility.

  As commercially available products of (meth) acrylic rubber, Nipol series made by Nippon Zeon Co., Ltd., Knoxite series made by NOK Co., Ltd., Toaclon series made by Toupe Co., Ltd., JSR Co., Ltd. AREX series etc. are mentioned.

  From the viewpoint of imparting heat resistance to the composition of the present invention, the polyester elastomer of Component B is preferably a polyester resin having a high melting point. From such a viewpoint, the melting point of the polyester elastomer is 160 to 300 ° C., preferably 170 to 290 ° C., and more preferably 180 to 280 ° C. The melting point of the polyester elastomer is 300 ° C. or less from the viewpoint of preventing the thermal decomposition of the (meth) acrylic elastomer.

  From the viewpoint of imparting flexibility to the composition of the present invention, Component B is preferably a flexible polyester elastomer. From this point of view, the flexural modulus of the polyester elastomer is preferably 1000 MPa or less, and from the viewpoint of flexibility, 10 MPa or more is preferable. From these viewpoints, the flexural modulus of the polyester elastomer is preferably 10 to 1000 MPa, more preferably 50 to 900 MPa, and still more preferably 80 to 800 MPa.

  As a hard segment which comprises a polyester elastomer, a crystalline polyester block is preferable and the crystalline polyester block formed of the condensation reaction of an aromatic dicarboxylic acid compound and a C2-C6 alkylene glycol is preferable. Examples of aromatic dicarboxylic acid compounds include terephthalic acid, isophthalic acid, alkyl esters of these acids, anhydrides and the like. As a C2-C6 alkylene glycol, a 1, 2- ethanediol, a 1, 3- propanediol, a 1, 4- butanediol etc. are mentioned.

  Examples of the soft segment constituting the polyester elastomer include a polyester type polymer block, a polyether type polymer block, a polycarbonate type polymer block and the like, and among these, a polyester type polymer block is preferable from the viewpoint of heat aging resistance.

  Examples of the polyester type polymer block include polycaprolactone, polyenane lactone, polycaprylo lactone, and a polyalkylene ester formed by condensation reaction of an aliphatic dicarboxylic acid compound and an aliphatic diol. Examples of polyalkylene esters formed by condensation reaction of an aliphatic dicarboxylic acid compound and an aliphatic diol include polybutylene adipate and the like.

  The number average molecular weight of the blocks constituting the soft segment is preferably 400 to 6000, more preferably 500 to 4000, from the viewpoint of flexibility.

  From the viewpoint of heat resistance, the melting point of the block constituting the hard segment is preferably higher than 160 ° C, more preferably 160 to 300 ° C, and still more preferably 170 to 290 ° C.

  On the other hand, the glass transition temperature of the block constituting the soft segment is preferably less than 0 ° C, more preferably -100 to -5 ° C, still more preferably -80 to -10 ° C, from the viewpoint of flexibility. .

  From the above, the polyester elastomer is preferably a block copolymer including a hard segment consisting of a crystalline polyester block having a melting point of more than 160 ° C. and a soft segment consisting of a polyester type polymer block having a glass transition temperature of less than 0 ° C.

  The weight ratio of hard segment to soft segment (hard segment / soft segment) in the polyester elastomer is preferably 90/10 to 10/90, more preferably 80/20 to 20/80, from the viewpoint of flexibility.

  Examples of commercially available polyester elastomers include Pelpren P series and S series manufactured by Toyobo Co., Ltd., and Hytrel series manufactured by Toray DuPont Co., Ltd.

  In the composition of the present invention, the mass ratio of component A to component B (component A / component B) is 60/40 to 90/10, preferably 65/35 to 90/10 from the viewpoint of flexibility. is there.

  The total content of the component A and the component B is preferably 65% by mass or more, more preferably 70 to 99.99% by mass, and still more preferably 75 to 99.9% by mass in the composition of the present invention.

  Component C is an organic acid metal salt.

Examples of the organic acid component of the organic acid metal salt include aliphatic organic acids and aromatic organic acids.
Examples of aliphatic organic acids include fumaric acid, caprylic acid, lauric acid, stearic acid, 12-hydroxystearic acid, oleic acid, ricinoleic acid, montanic acid and the like, and the carbon number of aliphatic organic acids is preferably 4 To 30, more preferably 6 to 28. Examples of aromatic organic acids include benzoic acid and trimethylbenzoic acid. Among these, from the viewpoint of moldability and strength, aliphatic organic acids having 8 to 20 carbon atoms are preferable, and stearic acid is more preferable.

  Examples of the metal component of the organic acid metal salt include lithium, potassium, sodium, calcium, magnesium, aluminum, barium, zinc, tin, lead and the like, among them sodium, calcium and zinc from the viewpoint of formability. Is preferred, and sodium and calcium are more preferred.

  The content of Component C is 0.01 parts by mass or more from the viewpoint of lowering the melt viscosity of the composition of the present invention and improving the formability with respect to 100 parts by mass in total of Component A and Component B. From the viewpoint of improving the mechanical strength of the composition, the amount is 5 parts by mass or less. From these viewpoints, the content of component C is 0.01 to 5 parts by mass, preferably 0.02 to 4 parts by mass, and more preferably 0.03 to 3 parts by mass with respect to a total of 100 parts by mass of component A and component B. It is a mass part. When a plurality of organic acid metal salts are used in combination, the content is the total amount.

When a large amount of the organic acid metal salt is blended, the mechanical strength of the composition of the present invention decreases, but the mechanical strength can be increased and the melt flowability can be improved in a predetermined range. The preferred range depends on the type of metal component as follows. The difference due to such metal species is presumed to be due to the difference in meltability at the time of kneading with other components and the difference in the reaction rate of the component A and the component B accordingly.
When the organic acid metal salt is a sodium salt, the content thereof is preferably 0.05 to 0.4 parts by mass, more preferably 0.1 to 0.4 parts by mass, still more preferably 100 parts by mass in total of component A and component B. It is 0.15 to 0.2 parts by mass.
When the organic acid metal salt is a calcium salt, the content thereof is preferably 0.05 to 0.2 parts by mass, more preferably 0.07 to 0.15 parts by mass with respect to 100 parts by mass in total of the component A and the component B.
When the organic acid metal salt is a zinc salt, the content thereof is preferably 0.01 to 0.1 parts by mass, more preferably 0.015 to 0.07 parts by mass with respect to 100 parts by mass in total of the component A and the component B.
When the organic acid metal salt is an aluminum salt, the content thereof is preferably 0.05 to 0.2 parts by mass, more preferably 0.07 to 0.15 parts by mass with respect to 100 parts by mass in total of the component A and the component B.

  In the composition of the present invention, from the viewpoint of improving the strength and oil resistance of the composition, it is preferable to crosslink the (meth) acrylic rubber of the component A. Therefore, the composition of the present invention It is preferable to contain a rubber crosslinking agent having reactivity with the epoxy group that the acrylic rubber has.

  As a functional group which has reactivity with the epoxy group which a rubber crosslinking agent has, a carboxy group, an acid anhydride group, a phenol group, an amino group etc. are mentioned.

  Examples of the rubber crosslinking agent having a carboxy group include succinic acid, adipic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid and the like.

  As a rubber crosslinking agent having an acid anhydride group, hexahydrophthalic anhydride (Rikasid HH, manufactured by Shin Nippon Chemical Co., Ltd.), ethylene glycol bisanhydro trimellitate (Rikasid TMEG-100, manufactured by Shin Nippon Rika Co., Ltd.) And glycerin bisanhydrotrimellitate monoacetate (Rikasid TMTA-C, manufactured by Shin Nippon Chemical Co., Ltd.), succinic anhydride, adipic anhydride, trimellitic anhydride and the like.

  As a rubber crosslinking agent which has a phenol group, hydroquinone, orcinol, monohydroxybenzoic acid, gallic acid etc. are mentioned.

  Examples of the rubber crosslinking agent having an amino group include hexamethylene diamine, triethylene tetramine, and hexamethylene diamine carbamate.

  The rubber crosslinking agent may be a polymer type crosslinking agent of the rubber crosslinking agent. A polymer type crosslinking agent is preferable because thermal decomposition and dispersal hardly occur in the production temperature range of the composition of the present invention. As a polymer type crosslinking agent, polyolefin polymers obtained by copolymerizing or graft polymerizing acrylic acid, maleic acid and the like, polystyrene polymers, polyvinyl phenol polymers, acrylic polymers and the like, olefin monomers, styrene type Monomers, copolymers using acrylic monomers and the like, alkylphenol-formaldehyde condensates, polyamide polymers and the like are mentioned. Among these, polyvinylphenol polymers and alkylphenol-formaldehyde condensates are preferred.

  Examples of generally available commercially available products of the polymer type crosslinking agent include the following. Examples of polyolefin polymers having a carboxy group and / or an acid anhydride group include Sumifit (manufactured by Sumika Chemtex Co., Ltd.), Admar (manufactured by Mitsui Chemicals, Inc.), Umex (manufactured by Sanyo Chemical Industries, Ltd.), etc. Can be mentioned. As styrene-acrylic copolymers and acrylic polymers having a carboxy group, Alphon UC series (manufactured by Toagosei Co., Ltd.), Blenmer (manufactured by NOF Corporation), Actflow (manufactured by Soken Chemical Co., Ltd.), etc. Can be mentioned. Examples of the polyvinyl phenol polymer include Marca Linker (manufactured by Maruzen Petrochemical Co., Ltd.) and the like. Examples of the alkylphenol-formaldehyde condensate include Tackyroll (manufactured by Taoka Chemical Industry Co., Ltd.) and the like.

  The content of the component D is preferably 0.1 parts by mass or more from the viewpoint of strength with respect to 100 parts by mass in total of the component A and the component B, and is preferably 20 parts by mass or less from the viewpoint of flexibility. From these viewpoints, the content of component D is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 15 parts by mass, and still more preferably 0.3 to 10 parts by mass with respect to 100 parts by mass in total of component A and component B It is a department.

  The composition of the present invention preferably further contains a component E: plasticizer from the viewpoint of lowering the melt viscosity and improving the moldability.

  Examples of the plasticizer include polyester plasticizers, polycaprolactones, phthalic acid ester plasticizers, trimellitic acid ester plasticizers, adipic acid ester plasticizers and the like.

  As polyester plasticizers, crystalline polyester plasticizers are preferred. When the molding process is carried out at a temperature exceeding the melting point of the crystalline polyester plasticizer, the rubber component of the component A relative to the component B, because the crystalline polyester plasticizer reduces the melt viscosity of the composition as a liquid plasticizer. In spite of being contained in a large amount, the melt flowability is enhanced and the formability is improved without largely affecting the mechanical strength.

  The melting point of the crystalline polyester plasticizer is preferably 130 ° C. or higher from the viewpoint of maintaining the mechanical strength of the composition of the present invention even at a low temperature, and the mechanical strength is reduced by the thermal decomposition of component A (meth) acrylic rubber From a viewpoint of preventing, 300 degrees C or less is preferable. From these viewpoints, the melting point of the polyester plasticizer is preferably 130 to 300 ° C., more preferably 140 to 290 ° C., and still more preferably 150 to 280 ° C.

  The crystalline polyester plasticizer is preferably obtained by the condensation reaction of a carboxylic acid component containing an aromatic dicarboxylic acid compound and an alcohol component containing an aliphatic diol. Examples of aromatic dicarboxylic acid compounds include terephthalic acid, isophthalic acid, alkyl esters of these acids, anhydrides and the like. Examples of aliphatic diols include aliphatic diols having 4 to 18 carbon atoms such as 1,4-butanediol and 1,6-hexanediol.

  Commercially available commercially available crystalline polyester plasticizers include Polysizer A51 (melting point: 199 ° C., number average molecular weight: 470, weight average molecular weight: 1300, molecular weight distribution Mw / Mn: 2.7) manufactured by DCC Co., Ltd., Polysizer A55 (melting point: 212 ° C., number average molecular weight: 900, weight average molecular weight: 2400, molecular weight distribution Mw / Mn: 2.7), and the like.

  The number average molecular weight of the crystalline polyester plasticizer is preferably 300 or more from the viewpoint of suppressing volatility, and is preferably 5000 or less from the viewpoint of melt viscosity. From these viewpoints, the number average molecular weight of the crystalline polyester plasticizer is preferably 300 to 5,000, more preferably 400 to 3,000, and still more preferably 450 to 2,000.

  On the other hand, unlike general polyester plasticizers, polycaprolactone is excellent in thermal stability even in a heating environment, has a characteristic that is difficult to volatilize, and is also excellent in heat aging resistance. Moreover, since it has a structure similar to the soft segment of the polyester elastomer of component B, it is excellent in compatibility.

  From the above viewpoints, polycaprolactone is preferably an aliphatic polyester obtained by ring-opening polymerization of ε-caprolactone. In addition, the weight average molecular weight of polycaprolactone is preferably 300 or more from the viewpoint of water resistance, and 50000 or less from the viewpoint of improvement in mechanical strength. From these viewpoints, the weight average molecular weight of polycaprolactone is preferably 300 to 50,000, more preferably 500 to 30,000, and still more preferably 1,000 to 20,000.

  Examples of commercially available products of polycaprolactone include Plaxel series manufactured by Daicel Corporation.

  The content of the component E is preferably 0.1 parts by mass or more from the viewpoint of formability with respect to 100 parts by mass in total of the component A and the component B, and preferably 30 parts by mass or less from the viewpoint of flexibility. From these viewpoints, the content of component E is preferably 0.1 to 30 parts by mass, more preferably 0.3 to 25 parts by mass, and still more preferably 0.5 to 50 parts by mass with respect to 100 parts by mass in total of component A and component B. The amount is 20 parts by mass, more preferably 0.5 to 7 parts by mass.

  The composition of the present invention preferably further contains Component F: a thermal stabilizer from the viewpoint of suppressing the change in the properties of the composition of the present invention under heating conditions.

  As a heat stabilizer, a phenolic antioxidant, an organophosphorus antioxidant, an organic sulfur antioxidant, an amine antioxidant, etc. are mentioned.

  Examples of phenolic antioxidants include 2,6-di-t-butyl-p-cresol (Nocrac 200, manufactured by Ouchi Shinko Chemical Co., Ltd.), 4,4'-thiobis (6-t-butyl-3) -Methylphenol) (Sumilyzer WX-R, manufactured by Sumitomo Chemical Co., Ltd.) n-octadecyl-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenol) propionate (IRGANOX 1076, BASF Manufactured products, tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenol) propionate] methane (Irganox 1010, manufactured by BASF) and the like.

  Examples of organic phosphorus antioxidants include tris (nonylphenyl) phosphite (Nocrac TNP, manufactured by Ouchi Emerging Chemical Industry Co., Ltd.), diphenyl mono (2-ethylhexyl) phosphite (JPM-308, Johoku Chemical Co., Ltd.) (Made by Co., Ltd.), triphenyl phosphite (ADEKA Stub 3010, made by ADECA), bis (2,6-di-t-butyl-4-methylphenyl pentaerythritol diphosphite) (ADEKA Stab PEP-36, Manufactured by Adeka Co., Ltd., tetra (alkyl having 12 to 15 carbon atoms) -4,4'-isopropylidene diphenyl phosphite (Adekastab 1500, manufactured by Adeka Co., Ltd.), and the like.

  Examples of organic sulfur-based antioxidants include dilauryl 3,3'-thiodipropionate (Sumilyzer TRL-R, manufactured by Sumitomo Chemical Co., Ltd.), distearyl 3,3'-thiodipropionate (Sumilyzer TPS, Sumitomo Chemical Inc., pentaerythritol tetrakis (3-laurylthiopropionate) (Sumilyzer TP-D, Sumitomo Chemical Co., Ltd.), 2-mercaptobenzimidazole (Sumilyzer MD, Sumitomo Chemical Co., Ltd.), etc. It can be mentioned.

  Examples of amine antioxidants include N, N-diphenylethylenediamine, N, N-diphenylacetamidine, N, N-diphenylflumuamidine, N-phenylpiperidine, dibenzylethylenediamine, triethanolamine, phenothiazine, N, N ′. -Di-sec-butyl-p-phenylenediamine, 4,4'-tetramethyl-diaminodiphenylmethane, P, P'-dioctyl-diphenylamine, N, N'-bis (1,4-dimethyl-pentyl) -p- Amines such as phenylenediamine, phenyl-α-naphthylamine, phenyl-β-naphthylamine, 4,4'-bis (4-α, α-dimethyl-benzyl) diphenylamine and derivatives thereof, reaction products of amines and aldehydes, amines And the reaction product of ketone and the like.

  Other antioxidants include 2- [1- (2-hydroxy-3,5-di-tertiary-pentylphenyl) ethyl] -4,6-di-tertiary having a combination of phenol and unsaturated bond. Pentyl phenyl acrylate (Sumilyzer GS, manufactured by Sumitomo Chemical Co., Ltd.), 2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (Sumilyzer GM) Sumitomo Chemical Co., Ltd., etc., and 6- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propoxy] -2,4,8,10 having both phenol and organophosphorus structures. And tetra-tertiary-butyldibenzo [d, f] [1,3,2] dioxafospepine (Sumilyzer GP, manufactured by Sumitomo Chemical Co., Ltd.) and the like.

  The content of the component F is preferably 0.01 parts by mass or more from the viewpoint of heat aging resistance, and 15 parts by mass or less from the viewpoint of mechanical strength with respect to 100 parts by mass in total of the component A and the component B. From these viewpoints, the content of the component F is preferably 0.01 to 15 parts by mass, more preferably 0.05 to 10 parts by mass with respect to 100 parts by mass of the total amount of the component A and the component B.

  Other additives include: lubricants such as fatty acid esters; light stabilizers such as benzotriazole compounds, benzophenone compounds, benzoate compounds and hindered phenol compounds; hydrolysis inhibitors such as carbodiimide compounds and oxazoline compounds; phthalic acid Ester based compounds, polyester compounds, (meth) acrylic oligomers, plasticizers such as process oil, inorganic foaming agents such as sodium bicarbonate and ammonium bicarbonate, organic foaming agents such as nitro compounds, azo compounds and sulfonyl hydrazides; carbon Fillers such as black, calcium carbonate, talc and glass fiber; flame retardants such as tetrabromophenol, ammonium polyphosphate, melamine cyanurate, magnesium hydroxide and aluminum hydroxide; silane coupling agents, titanate coupling Compatibilizing agents such as an aluminate-based coupling agent or an acid-modified polyolefin resin; pigments, dyes, and the like.

  In the composition of the present invention, a raw material mixture containing at least Component A, Component B, and Component C, and, optionally, additives such as Component D, Component E, Component F, etc. is heated by an extruder or a kneader It is preferable to obtain by the method of kneading.

  The heating and kneading temperature is preferably a temperature above the melting point of component B, more preferably component B, from the viewpoint of promoting the reaction between the epoxy group of component A and the molecular terminal functional group of component B and improving the mechanical strength. Temperature of 10 ° C. or higher, more preferably 20 ° C. or higher, and preferably 350 ° C. or less, more preferably 320 ° C. from the viewpoint of preventing a decrease in mechanical properties due to thermal decomposition of component A. C. or less, more preferably 300 ° C. or less.

  As an extruder, a single screw extruder, a parallel screw twin screw extruder, a conical screw twin screw extruder etc. are mentioned, for example.

  The term "kneader" means a batch-type mixer capable of temperature control, and examples include Banbury mixer, Brabender plastograph, Labo Plastomill and the like.

  Each component may be charged in a batch, separately, or divided into an extruder or a kneader.

  The composition of the present invention can be in the form of pellets, powders, sheets, etc., depending on the application. For example, it is melt-kneaded by an extruder and extruded into a strand, and while being cooled in cold water, it is cut by a cutter into pellets such as cylindrical and rice grains. The obtained pellets are usually formed into a predetermined sheet-like molded article or mold molded article by injection molding or extrusion molding. Alternatively, the melt-kneaded product can be formed into a pellet by a ruler or the like to be used as a molding material. It is good also as an intermediate product which stuck pasteboard etc. to a sheet-like thermoplastic elastomer composition.

  The composition of the present invention is not particularly limited, and can be used in fields where general styrene elastomers, polyolefin elastomers, polyurethane elastomers, polyamide elastomers, acrylic elastomers, polyester elastomers, etc. are used. However, the composition of the present invention is excellent in flexibility, heat resistance, mechanical strength, and moldability, and can be used for hoses, packings, etc. used under high temperature environment such as automobile engine surroundings. Further, unlike crosslinked rubbers and the like conventionally used because they have excellent molding processability, they are excellent in productivity and recyclability.

  The A hardness of the composition of the present invention is preferably 10 to 95, more preferably 20 to 90, and still more preferably 40 to 90, from the viewpoint of flexibility.

  Further, the D hardness of the composition of the present invention is preferably less than 30, more preferably 10 or more and less than 30, from the viewpoint of flexibility.

  A molded body is obtained by appropriately thermoforming the composition of the present invention according to a conventional method.

  The temperature during heat molding is preferably 180 ° C. or higher from the viewpoint of the flowability of the composition and the moldability resulting therefrom, and from the viewpoint of preventing the thermal decomposition of the (meth) acrylic rubber of the component A in the composition, 350 degrees C or less is preferable. From these viewpoints, the temperature at the time of heat molding is preferably 180 to 350 ° C., and more preferably 200 to 320 ° C.

  As an apparatus used for producing a molded article using the composition of the present invention, any molding machine capable of melt-forming the composition can be used. For example, a kneader, an extrusion molding machine, an injection molding machine, a press molding machine, a blow molding machine, a mixing roll and the like can be mentioned.

  Since the molded article obtained by molding the thermoplastic elastomer composition of the present invention is excellent in heat resistance, it is used for applications requiring heat resistance of, for example, 100 ° C. or more (120 ° C. or more, 150 ° C. or more depending on design). Can also be suitably used.

  EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited by these examples. Various physical properties of the raw materials used in Examples and Comparative Examples were measured by the following methods.

<Component A>
[Monomer composition]
A sample is thermally decomposed at 550 ° C. using a gas chromatograph mass spectrometer (gas chromatograph 7890A manufactured by Agilent Technologies, Inc., mass spectrometer Jms-Q1000 GC K9 manufactured by Nippon Denshi Co., Ltd.), and mass spectrometry of the thermal decomposition product is performed. To analyze the monomer composition.
〔Glass-transition temperature〕
The glass transition temperature is determined from a chart obtained by raising the temperature from 25 ° C. to 280 ° C. at 10 ° C./min according to the method defined by JIS K 7121 using a differential scanning calorimetry (DSC) apparatus.

<Component B>
[Melting point]
The temperature of the melting peak obtained by raising the temperature at 10 ° C./min according to the method defined by JIS K 7121 using a differential scanning calorimetry (DSC) apparatus is taken as the melting point. When multiple melting peaks appear, the melting peak that appears at a lower temperature is taken as the melting point.
[Flexural modulus]
According to the ASTM D 790 standard, a specimen of 127 mm × 12.7 mm thickness 3.2 mm obtained by injection molding is placed at a temperature of 23 ° C. and a relative humidity of 50% for 40 hours, and then the speed of 1.4 mm / min using an autograph Add a vertical displacement, and calculate the flexural modulus from the load-deflection curve.

<Component E>
[Melting point (Tm)]
The temperature of the melting peak obtained by raising the temperature from 25 ° C. to 280 ° C. at 10 ° C./min according to the method defined by JIS K 7121 using a differential scanning calorimetry (DSC) apparatus is taken as the melting point. When multiple melting peaks appear, the melting peak that appears at a lower temperature is taken as the melting point.
[Number average molecular weight (Mn) and weight average molecular weight (Mw)]
Measurement is performed by gel permeation chromatography (GPC) using hexafluoroisopropanol as an eluent, and the number average molecular weight and the weight average molecular weight are calculated based on the measurement results of polymethyl methacrylate (PMMA) molecular weight standards.

Examples 1 to 25 and Comparative Examples 1 to 13
(1) Preparation of thermoplastic elastomer composition (press sheet)
A total of 54 g of raw material components with composition ratios (mass ratios) shown in Tables 6 to 8 are put into a batch-type kneader "Plastograph EC 50 type" (Brabender) heated to 240 ° C, and the rotation speed is 100 r / min. The mixture was melt-kneaded at 240-290.degree. The entire kneaded mixture in the molten state was taken out in a kneading time of 10 minutes and cooled at room temperature to obtain a composition.
Each composition was heated to 240 ° C. using a heat press apparatus “TB-50-2” (manufactured by Toho Machinery Co., Ltd., 50 t hydraulic press) in a 2 mm thick × 12 cm wide × 15 cm long mold form The sheet was heated at 5 MPa for 2 minutes and subjected to cooling press processing at 5 MPa for 3 minutes to produce a pressed sheet.

  The detail of the raw material component used by the Example and the comparative example is shown to Tables 1-5.

  The following evaluation was performed about the composition obtained by the Example and the comparative example. The results are shown in Tables 6-9.

(1) Flexibility (A hardness)
The pressed sheet was allowed to stand in a constant temperature and humidity chamber (temperature 23 ° C., relative humidity 50%) for 24 hours or more to stabilize the state of the sheet. Three pressed sheets each having a thickness of 2 mm were stacked, and the A hardness was measured according to JIS K 7215 “Durometer hardness test method for plastic”.

[D hardness]
Similar to the A hardness, the D hardness is measured according to JIS K 7215 “Durometer hardness test method for plastic”.

(2) Mechanical strength (tensile breaking strength)
From the press sheet, a No. 3 test piece described in JIS K7113 is produced using a die-cut machine, and a tensile tester (Autograph AG-50kND type) manufactured by Shimadzu Corporation is used under a temperature environment of 23 ° C. The test piece was pulled at a speed of 200 mm / min. The stress at break (MPa) of the test piece was recorded as the breaking strength. The higher the breaking strength, the better the mechanical strength.

(3) Heat resistance [compression set rate]
From a press sheet, seven 29 mm disk sheets are produced using a die-cut machine, and heat is applied under conditions of heating at 5 ° C for 10 minutes, heating at 5MPa and cooling for 10 minutes at 5MPa using a compression set strain die. Press processing was performed, and a cylindrical test piece with a diameter of 29 mm and a height of 12.5 mm was produced. The compression set rate (%) was measured under the conditions of 120 ° C. and 24 hours according to JIS K6262 “Vulcanized rubber and thermoplastic rubber—determination of compression set at normal temperature, high temperature and low temperature”. The smaller the compression set rate, the better the heat resistance.

(4) Formability (apparent viscosity)
The apparent viscosity (A) of a sample 17 g was set at 240 ° C. by a capillary rheometer (Capillary Graph 1D, manufactured by Toyo Seiki Seisakusho Co., Ltd.), using a die with a diameter of 1 mm × 10 mm and a shear rate of 3648 / sec Pa · s) was measured. The lower the apparent viscosity, the better the formability.

(5) Heat aging resistance (Examples 12 and 14 to 18 only)
A No. 3 test piece described in JIS K7113 is produced from a press sheet using a die-cut machine, and heated at 150 ° C. for 500 hours using a gear oven (CTD-45P, manufactured by Toyo Seiki Seisakusho Co., Ltd.). After standing for 24 hours in a temperature-controlled room, a tensile test is carried out in the same manner as the mechanical strength (tensile breaking strength) of (2) above, and the retention of tensile strength and tensile breaking elongation (measured value after heat treatment / before heat treatment) The measured value of x 100,%) was determined. The higher the retention rate, the better the heat aging resistance.

From the results of Tables 6 to 8, it can be seen that the compositions of Examples 1 to 25 are all excellent in flexibility, mechanical strength, compression set resistance and moldability.
For example, from the comparison between Example 2 and Comparative Example 2, Example 14 and Comparative Example 7, Example 15 and Comparative Example 8, and Example 16 and Comparative Example 9, mechanical strength and the like can be obtained by blending the organic acid metal salt. It can be seen that the formability is improved without loss.
Moreover, the heat aging resistance uses the thing containing 40 mol% or more of ethyl acrylate in a monomer unit as (meth) acrylic rubber of the component A, and a soft segment is a polyester type polymer block as a polyester elastomer of the component B The soft segment of Example 18 and Component B, in which the content of ethyl acrylate constituting Component A is less than 40% by mole in the monomer unit, is significantly improved as shown in Table Compared with Example 16 which is an ether type block, Examples 12, 14, 15 and 17 satisfying these requirements have tensile strength and tensile elongation at break even under the extremely severe conditions of heating at 150 ° C. for 500 hours. It can be seen that the drop is significantly suppressed.
Comparative Example 4 is lower in flexibility, heat resistance, and moldability because the amount of the acrylic rubber having an epoxy group relative to the polyester elastomer is smaller than that of Example 2.
In Comparative Example 6, in contrast to Example 12, the heat resistance is lowered because the acrylic rubber having a carboxy group is blended instead of the acrylic rubber having an epoxy group.
Comparative Example 10, in contrast to Example 12, is significantly lacking in flexibility, heat resistance, and moldability because it is blended with a hard polyester resin instead of a polyester elastomer.
Since the comparative example 11 is mix | blending the organic acid which does not contain a metal component, even with respect to the comparative example 2, the moldability is not improved.

Reference Examples A1 to A2 and B1 to B2
Epoxy group-containing acrylic rubber or carboxy group-containing acrylic rubber shown in Table 10, polyester elastomer (Pelprene S1002 (made by Toyobo Co., Ltd.)), and crosslinking agent (Chemnox AC-6 (made by Unimatec Co., Ltd.), hexamethylene diamine The carbamate was kneaded with a kneader and cooled to obtain a composition. Physical properties of the obtained composition are shown in Table 10. The methods for measuring the A hardness, D hardness, tensile strength at break, and compression set rate are the same as described above. However, the compression set rate was measured at 70 ° C. for 24 hours, not at 120 ° C. for 24 hours. The kneading torque was measured at a point 10 minutes after the start of kneading, the kneading torque of the kneader in the production process of the composition.

From the results of Table 10, it can be seen that the tensile strength and compression set of Reference Examples A1 to A2 using acrylic rubber are significantly superior to those of Reference Examples B1 to B2, but the kneading torque is high. The increase of the kneading torque is presumed to be because the reaction between the epoxy group in the acrylic rubber and the molecular terminal functional group of the polyester elastomer strengthens the interface between the rubber and the polyester.
From the results, although the composition of Reference Examples A1 to A2 having an epoxy group is superior in tensile strength and compression set resistance to the composition of Reference Examples B1 to B2 having a carboxy group, the formability is excellent. It turns out that there is a problem that it is inferior.

  The thermoplastic elastomer composition of the present invention is useful for various molded articles such as automobiles, electronic materials, home appliances, electric devices, medical devices, packaging materials, stationery and accessories, etc. Furthermore, grips, tubes, packings, gaskets, It is used for various members, such as a cushion body, a film, and a sheet.

Claims (5)

Component A: (meth) acrylic rubber having an epoxy group
Component B: a polyester elastomer having a melting point of 160 to 300 ° C., and Component C: a metal of at least one organic acid selected from the group consisting of aliphatic organic acids having 4 to 30 carbon atoms, benzoic acid, and trimethylbenzoic acid a salt, metal components, and also contains sodium, calcium, zinc, and at least Tanedea Ru Yes hexane metal salt selected from the group consisting of aluminum,
The mass ratio of the component A to the component B (component A / component B) is 60/40 to 90/10, and the content of the component C with respect to a total of 100 parts by mass of the component A and the component B is the organic acid When the metal salt is a sodium salt, it is 0.05 to 0.4 parts by mass, when the metal salt of an organic acid is a calcium salt, it is 0.05 to 0.2 parts by mass, and when the metal salt of an organic acid is a zinc salt, 0.01 The thermoplastic elastomer composition which is -0.1 mass part and 0.05-0.2 mass part when the said organic acid metal salt is an aluminum salt.   The (meth) acrylic monomer constituting the (meth) acrylic rubber having the epoxy group of the component A contains 40 mol% or more of ethyl acrylate, and the polyester elastomer of the component B contains a soft segment consisting of a polyester type polymer block The thermoplastic elastomer composition according to claim 1, which is a block copolymer.   The polyester elastomer of Component B is a block copolymer comprising a hard segment consisting of a crystalline polyester block having a melting point of above 160 ° C. and a soft segment consisting of a polyester type polymer block having a glass transition temperature of below 0 ° C. Or the thermoplastic elastomer composition according to 2.   Furthermore, the thermoplastic resin according to any one of claims 1 to 3, wherein component D: a rubber crosslinking agent having reactivity with an epoxy group is contained in an amount of 0.1 to 20 parts by mass with respect to 100 parts by mass in total of component A and component B Elastomeric composition.   The molded object obtained by heat-molding the thermoplastic-elastomer composition in any one of Claims 1-4.