JP2003089732A - Thermoplastic elastomer composition and molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermoplastic elastomer composition excellent in balance of rubber elasticity, flexibility, scratch resistance and mechanical properties, and provide a molded product in which scratch resistance is required. SOLUTION: The thermoplastic elastomer composition comprises (a) an ethylene-α-olefin-based random copolymer, (b) an olefin resin, (c) a (meth) acrylate resin, (d) a hydrogenated diene-based polymer, and as necessary, (e) a softening agent, and at least the components (a) and (b) are dynamically heat-treated in the presence of a crosslinking agent. The molded product is obtained by using the elastomer composition.

Description

Detailed Description of the Invention

The present invention relates to thermoplastic elastomer compositions, and more particularly to flexibility, scratch resistance, mechanical properties,
The present invention relates to an olefin-based thermoplastic elastomer composition having excellent rubber elasticity and a molded article.

TECHNICAL FIELD OF THE INVENTION

[0002]

2. Description of the Related Art In recent years, thermoplastic elastomers, which are rubber-like soft materials and do not require a vulcanization process and have the same moldability as thermoplastic resins, have been used for automobile parts, home electric appliance parts, medical care, and foods. It is used in the fields of equipment parts, electric wires and sundries. Currently, as such thermoplastic elastomers, various types of polymers such as polyolefin type, polystyrene type, polyurethane type, polyester type, and vinyl chloride type have been developed and are commercially available. Among the above thermoplastic elastomers, a blend of olefin resin and ethylene / α-olefin random copolymer as a main raw material, and a cross-linking agent of olefin resin and ethylene / α-olefin random copolymer as a main raw material. The olefinic thermoplastic elastomer partially crosslinked by
It has excellent weather resistance, cold resistance, and moldability and is a relatively inexpensive material.
Alternative materials for metal parts mainly for weight reduction, longer life of parts, alternative materials for RIM urethane parts mainly for cost reduction, vulcanization mainly for simplification of processing process, recyclability, and cost reduction It is attracting attention as a substitute material for rubber, a substitute material for soft polyvinyl chloride whose main purpose is to improve the service life of parts, and to improve contamination, and its demand is increasing year by year.

However, the olefinic thermoplastic elastomer is inferior in surface scratch resistance (scratch resistance) and is required to have a scratch resistance, for example, a molded article such as an inner panel or a skin material of a console box. There are problems with the adoption of.

[0004]

The present invention has been made in view of the above-mentioned problems of the prior art, and has the characteristics of conventional olefinic thermoplastic elastomers, and has rubber elasticity, flexibility, scratch resistance and mechanical properties. It is an object to provide a thermoplastic elastomer composition having an excellent balance of properties and a molded article using the same.

[0005]

DISCLOSURE OF THE INVENTION As a result of intensive studies to achieve the above objects, the present inventors have found that a thermoplastic elastomer is mixed with a specific amount of a (meth) acrylate resin and a hydrogenated diene-based polymer so as to be scratch resistant. The inventors have found that a thermoplastic elastomer composition having an excellent balance of stickiness, rubber elasticity, flexibility, and mechanical properties can be obtained, and completed the present invention.

The present invention provides the following thermoplastic elastomer composition and a molded article using the same. [1] (a) Ethylene / α-olefin random copolymer, (b) olefin resin, (c) (meth) acrylate resin, (d) hydrogenated diene polymer, and (e) if necessary. A thermoplastic elastomer composition comprising a softening agent, wherein at least (a) and (b) are dynamically heat-treated in the presence of a cross-linking agent. [2] (a) Ethylene / α-olefin random copolymer, (b) olefin resin, (c) (meth) acrylate resin, (d) hydrogenated diene polymer, and (e) if necessary. The thermoplastic elastomer composition according to the above [1], which is obtained by dynamically heat treating a mixture containing a softening agent in the presence of a crosslinking agent. [3] (a) 20% to 95% by weight of ethylene / α-olefin random copolymer, (b) olefin resin 3 to 70
% By weight, 1 to 20% by weight of (C) (meth) acrylate resin, 1 to 10% by weight of (D) hydrogenated diene polymer (provided that (A), (B), (C) and (D) The total amount is 1
The above [1] or [2] containing 100% by weight)
The thermoplastic elastomer composition according to. [4] The intrinsic viscosity [η] of the above (a) ethylene / α-olefin random copolymer measured in decalin solvent at 135 ° C. is 2.0 to 6.8 dl / g. The thermoplastic elastomer composition according to the above [1] to [3]. [5] The (d) hydrogenated diene-based polymer contains a polymer block (A) mainly containing a vinyl aromatic monomer and a polymer block (B) mainly containing a conjugated diene monomer. [1], which is a hydrogenated diene polymer
The thermoplastic elastomer composition according to any one of [4]. [6] A molded article containing the thermoplastic elastomer composition according to any one of the above [1] to [5].

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the thermoplastic elastomer composition of the present invention will be specifically described below. The thermoplastic elastomer composition of the present invention comprises (a) ethylene / α-
Olefin-based random copolymer, (b) olefin resin, (c) (meth) acrylate resin, (d) hydrogenated diene-based polymer, and optionally (v) a softening agent, at least the above (a) ) And (b) are dynamically heat-treated in the presence of a cross-linking agent to provide a thermoplastic elastomer composition. Hereinafter, each component will be described more specifically.

Ethylene / α-olefin random copolymer (a) The ethylene / α-olefin random copolymer (hereinafter also referred to as "(a) component") used in the present invention is, for example, ethylene / propylene. Copolymer rubber, ethylene / propylene / non-conjugated diene terpolymer rubber, ethylene / 1-butene copolymer rubber, ethylene / 1-butene
Examples thereof include random copolymers containing ethylene and an α-olefin having 3 to 10 carbon atoms as main components, such as a non-conjugated diene terpolymer rubber. Examples of the α-olefin having 3 to 10 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene and 1-octene, and propylene and 1-butene are particularly preferable. Examples of the non-conjugated diene include 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,7-octadiene, 1,9-decadiene, 3,
6-dimethyl-1,7-octadiene, 4,5-dimethyl-1,7-octadiene, 5-methyl-1,8-nonadiene, dicyclopentadiene, 5-ethylidene norbornene, 5-vinyl-2-norbornene, 2 , 5-norbornadiene and the like, particularly 1,4-hexadiene, dicyclopentadiene, 5-ethylidene-
2-norbornene is preferred.

In these ethylene / α-olefin random copolymers, α-olefin is preferably copolymerized in a proportion of 10% by weight or more. As the non-conjugated diene, ethylidene norbornene, dicyclopentadiene and 1,4-hexadiene are preferable, and the content thereof is 3 to 10 mol% (more than 100 mol% when the total of ethylene and α-olefin is 100 mol%). Preferably 3
.About.8 mol%) is preferable. The iodine value is 40 or less, preferably 5 to 30, more preferably 7
It is preferably -20. The ethylene / α-olefin random copolymer has an ethylene content of 90.
If it is more than 10% by weight and the α-olefin content is less than 10% by weight, flexibility of the copolymer rubber is insufficient, which is not preferable. The intrinsic viscosity [η] of the ethylene / α-olefin random copolymer measured at 135 ° C. in a decalin solvent is 1.0 dl / g or more, but preferably 2.0 to 6.8 dl /. g, more preferably 3.5-6.
It is 0 dl / g. If the intrinsic viscosity is less than 2.0 dl / g, the elastic recovery tends to decrease, while the 6.
When it exceeds 8 dl / g, the workability at the time of molding tends to decrease, which is not preferable. Further, the crystallinity by X-ray diffraction measurement is preferably 20% or less, more preferably 15% or less. When the crystallinity exceeds 20%, the flexibility of the copolymer rubber tends to decrease, which is not preferable. The ethylene / α-olefin-based random copolymer of the present invention may be an oil-extended polymer to which a softening agent described later is added at the time of polymerization.

The proportion of the component (a) in the thermoplastic elastomer composition is 20 to 95 wt% when the total amount of (i), (b), (c) and (d) is 100 wt%, It is preferably 30 to 90% by weight. If it is less than 20% by weight, the flexibility and rubber elasticity of the finally obtained thermoplastic elastomer composition will be poor, and if it exceeds 95% by weight, the fluidity of the finally obtained thermoplastic elastomer composition will decrease.
Moldability is extremely poor.

Olefin Resin The (b) olefin resin (hereinafter also referred to as “(b) component”) used in the present invention has 2 to 2 carbon atoms.
0 homo- or copolymers of α-olefins. Specific examples of the olefin resin include the following (co) polymers. (1) Ethylene homopolymer (manufacturing method may be low-pressure method or high-pressure method) (2) Copolymerization of ethylene with 10 mol% or less of other α-olefin or vinyl monomer such as vinyl acetate or ethyl acrylate Polymer (3) Propylene homopolymer (4) Random copolymer of propylene and 20 mol% or less of other α-olefin (5) Propylene and 30 mol%
The following block copolymers with other α-olefins (6)
1-Butene homopolymer (7) Random copolymer of 1-butene and 10 mol% or less of other α-olefin (8) 4−
Methyl-1-pentene homopolymer (9) 4-methyl-1-
Random copolymer of pentene and other α-olefin of 20 mol% or less Specific examples of the α-olefin include ethylene, propylene, 1-butene, and 4-methyl-olefin.
1-pentene, 1-hexene, 1-octene and the like can be mentioned. Among the above-mentioned olefin resins, a propylene homopolymer and a random copolymer of propylene and 20 mol% or less of another α-olefin are particularly preferable. The above-mentioned olefin resins can be used alone or in combination.

When the olefin resin used in the present invention is a crystalline olefin resin, the crystallinity determined by the X-ray method is usually 50% or more, preferably 55% or more. The density is 0.89 g / cm ³ or higher, more preferably at maximum peak temperature by differential scanning calorimetry it is preferable that the crystalline olefin resin be 0.90~0.94g / cm ^3, i.e. the melting point (hereinafter , Simply referred to as “T _m ”, is preferably 100 ° C. or higher (more preferably 120 ° C. or higher). If _Tm is less than 100 ° C, sufficient heat resistance and strength tend not to be exhibited. In addition, the melt flow rate (hereinafter simply referred to as “MFR”) (temperature 2
At 30 ° C. and a load of 2.16 kg) is preferably 0.
1 to 100 g / 10 minutes, more preferably 0.5 to 80 g
/ 10 minutes. If the MFR is less than 0.1 g / 10 minutes, the kneading processability and extrusion processability of the elastomer composition tend to be insufficient. On the other hand, if it exceeds 100 g / 10 minutes, the strength tends to decrease.

Therefore, the olefin resin used in the present invention has a crystallinity of 50% or more and a density of 0.89 g / cm.
³ or more, the content of ethylene units is 20 mol% or less, _Tm is 100 ° C. or more, and MFR is 0.1 to 0.1.
It is particularly preferable to use polypropylene and / or a copolymer of propylene and ethylene having a melting point of 140 to 170 ° C. and 100 g / 10 minutes.

As the olefin resin, an amorphous olefin resin may be used in addition to the above crystalline olefin resin.

As the amorphous olefin resin, homopolymers such as atactic polypropylene and atactic poly-1-butene, propylene (containing 50 mol% or more) and other α-olefins (ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-
Octene, 1-decene, etc.), 1-butene (containing 50 mol% or more) and other α-olefins (ethylene, propylene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, etc.) and the like.

Amorphous olefin resin at 190 ° C.
Melt viscosity is 50,000 cSt or less, preferably 100 to
30,000 cSt, more preferably 200 to 20,000
It is cSt. Furthermore, the crystallinity measured by X-ray diffraction is
Less than 50%, preferably 30% or less, more preferably 2
It is 0% or less. Density is 0.85-0.89g / c
m ^Three, And more preferably 0.85-0.88 g / cm^Threeso
Preferably there is. Furthermore, the number of amorphous olefin resins
Average molecular weight M_nIs 1000 to 20000 (more preferably
Is preferably 1500 to 15000).

Usually, the amorphous olefin resin is used in combination with the crystalline olefin resin, but only one of them may be used.

The proportion of the component (b) in the thermoplastic elastomer composition is 3 to 70% by weight when the total amount of (a), (b), (c) and (d) is 100% by weight, It is preferably 5 to 60% by weight. If it is less than 3% by weight, the phase structure (morphology) of the finally obtained thermoplastic elastomer composition is a good sea-island structure characteristic of the dynamically crosslinked thermoplastic elastomer [olefin resin is sea (matrix), crosslinked rubber is Islands], the molding processability and mechanical properties may deteriorate, and if it exceeds 70% by weight, the flexibility and rubber elasticity of the thermoplastic elastomer composition finally obtained are unfavorable.

(Meth) Acrylate Resin (ha) (meth) acrylate resin (hereinafter also referred to as “(ha) component”) used in the present invention contains a monomer having an acryl group or a methacryl group as a main component. It means a polymer of vinyl monomers. The monomer having an acrylic group or a methacrylic group is a monomer having at least one acrylic group or a methacrylic group, and examples thereof include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate. , N-butyl acrylate, t-butyl acrylate, s-butyl acrylate, 2-methylbutyl acrylate, 3-methylbutyl acrylate, n-hexyl acrylate, n-heptyl acrylate, n-octyl acrylate, acrylic Acrylic acid alkyl esters such as 2-ethylhexyl acid, ethylene glycol diacrylate, 1,2-propylene glycol diacrylic acid, 1,3-propylene glycol diacrylic acid, 1,2-butylene glycol diacrylic acid, 1,3-butylene diacrylic acid Glycol, diacrylic acid ,
A diacrylate such as 4-butylene glycol, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, s-butyl methacrylate, 2-methacrylic acid. Methyl butyl, 3-methyl butyl methacrylate, n-hexyl methacrylate, n-heptyl methacrylate, n-octyl methacrylate,
Methacrylic acid alkyl ester such as 2-ethylhexyl methacrylate, 1,2-propylene glycol dimethacrylate, 1,3-propylene glycol dimethacrylate, 1,2-butylene glycol dimethacrylate, 1,3-butylene dimethacrylate Examples thereof include glycol and alkyl dimethacrylate such as 1,4-butylene glycol dimethacrylate. Among these, a homopolymer of methyl methacrylate or a copolymer obtained by copolymerizing methyl methacrylate as a main component with a small amount of another monomer is preferably used. Examples of the other monomer include acrylic acid; metal salt of acrylic acid; methyl acrylate, ethyl acrylate, n-butyl acrylate, s-butyl acrylate, t-butyl acrylate, and acrylic acid 2.
-Acrylic acid esters such as ethylhexyl; methacrylic acid; methacrylic acid metal salts; ethyl methacrylate, n-butyl methacrylate, s-butyl methacrylate, t-butyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, Methacrylic acid esters such as cyclohexyl methacrylate; acetic acid esters such as vinyl acetate; aromatic vinyl compounds such as styrene and α-methylstyrene; maleic anhydride, maleic acid monoalkyl esters, maleic acid dialkyl esters, N- Examples thereof include maleimides such as phenylmaleimide. The type of copolymer is not particularly limited, and may be any of random copolymers, block copolymers such as diblock, triblock, multiblock, and comb-shaped blocks, and multistage graft copolymers. Good. The structure of the (meth) acrylate-based resin is not particularly limited, and may be any of linear type, branched type, multilayer type and the like. The melt flow rate (at a temperature of 230 ° C. and a load of 3.8 kg) of the (meth) acrylate resin is not particularly limited, but is preferably 0.1 to 100 g / 10 minutes, more preferably 0.5 to 8 g.
It is 0 g / 10 minutes.

The proportion of the component (c) in the thermoplastic elastomer composition is 1 to 20% by weight when the total amount of (a), (b), (c) and (d) is 100% by weight, It is preferably 5 to 15% by weight. If it is less than 1% by weight, the finally obtained thermoplastic elastomer composition is inferior in scratch resistance, and if it exceeds 20% by weight, the flexibility and rubber elasticity of the finally obtained thermoplastic elastomer composition are deteriorated, which is not preferable.

Hydrogenated diene-based polymer As the (d) hydrogenated diene-based polymer (hereinafter also referred to as "(d) component") used in the present invention, for example, a homopolymer or a conjugated diene monomer is used. Random copolymer of diene monomer and vinyl aromatic monomer, block copolymer composed of polymer block of vinyl aromatic monomer and polymer block of conjugated diene monomer, vinyl aromatic monomer Block copolymer consisting of polymer block of monomer and random copolymer block of conjugated diene monomer and vinyl aromatic monomer, polymer block of conjugated diene monomer and conjugated diene monomer and vinyl Block copolymer consisting of copolymer block of aromatic monomer, polymer block of conjugated diene monomer and vinyl aromatic monomer consisting of vinyl aromatic monomer and conjugated diene monomer gradually increasing Taper Block copolymer consisting of block, random copolymer of conjugated diene monomer and vinyl aromatic monomer Block vinyl, consisting of vinyl aromatic monomer and conjugated diene monomer, and gradually increasing vinyl aromatic monomer A block copolymer composed of a tapered block, a diene such as a block copolymer composed of a polybutadiene block having a vinyl bond of 30% by weight or less and a polymer block of a conjugated diene monomer having a vinyl bond of more than 30% by weight. Examples thereof include hydrogenated products of polymer (hereinafter sometimes referred to as “polymer before hydrogenation”).

Among the above hydrogenated diene polymers, a polymer block (A) containing a vinyl aromatic monomer as a main component and a polymer block (B) containing a conjugated diene monomer as a main component are contained. Hydrogenated products of conjugated diene-based polymers, particularly hydrogenated products of the block structure shown below, are preferable. The polymer block (A) is a homopolymer of a vinyl aromatic monomer or a vinyl aromatic monomer unit containing 50% by mass, preferably 70% by mass, of a vinyl aromatic monomer unit, It has a structure of a copolymer with another copolymerizable monomer, preferably a conjugated diene monomer, and the polymer block (B) is a homopolymer of a conjugated diene monomer or a vinyl aroma. It has a structure in which another monomer such as a group monomer is copolymerized at 5% by mass or less, and has a block structure of (AB) n.
-A type (n is an integer of 1 to 10) or (AB) m type (m is an integer of 2 to 10) block copolymer,
The A block at the end may have a relatively short B block. Further, [(AB) n] m-M type (M is a coupling agent residue such as Si or Sn, m is an integer of 2 to 4 as a valence of the coupling agent residue, and n is 1 to 10). Of integers, preferably 1 or 2.) are also included. The block copolymer may be A ₁ -B-A ₂ type or A ₁ -B ₁ -A ₂ -B ₂ type. The weight average molecular weights of the blocks B ₁ and B ₂ may be the same, or the weight average molecular weight of B ₂ may be smaller.

The vinyl aromatic monomer used for the hydrogenated diene polymer is styrene, α-methylstyrene, p-methylstyrene, t-butylstyrene, divinylbenzene, N, N-dimethyl-p. -Aminoethylstyrene, 2,4-dimethylstyrene, N, N-diethyl-p-aminoethylstyrene, 2,4-dimethylstyrene, vinylnaphthalene, vinylanthracene and the like, among which styrene and α-methylstyrene are preferable. preferable.

The conjugated diene monomer used in the hydrogenated diene polymer is 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3.
-Pentadiene, 2-methyl-1,3-pentadiene,
One or more kinds of 1,3-hexadiene, 4,5-dimethyl-1,3-octadiene, chloroprene and the like can be mentioned, and among them, 1,3-butadiene and isoprene are preferable. In the polymer block A, the other monomer copolymerizable with the vinyl aromatic monomer is mainly the above-mentioned conjugated diene monomer, and among them, 1,3-butadiene and isoprene are preferable.

The composition ratio of the conjugated diene monomer and the vinyl aromatic monomer constituting the pre-hydrogenation polymer (conjugated diene compound / vinyl aromatic compound) is 95/5 to 40 by weight.
/ 60 is preferable, and more preferably 93/7 to 45 /
55.

The vinyl bond content of the conjugated diene portion of the copolymer before hydrogenation (the ratio of 1,2- and 3,4-vinyl bonds of the conjugated diene portion of the copolymer before hydrogenation) is not particularly limited. No, but preferably 50-85%, especially 60-8
It is preferably 5%. In the hydrogenated diene polymer used in the present invention, 80% or more, preferably 90% or more, of the conjugated diene-derived double bond of the conjugated diene polymer is saturated. If the saturation ratio is less than 80%, the weather resistance and the like will deteriorate. Further, the weight average molecular weight of the hydrogenated diene polymer used in the present invention is preferably 50.
0 to 1,000,000, and more preferably 1000
It is in the range of 0-500000

The proportion of the component (d) in the thermoplastic elastomer composition is 1 to 10% by weight when the total amount of (a), (b), (c) and (d) is 100% by weight, It is preferably 2 to 9% by weight. If less than 1% by weight (meta)
Acrylate resin and olefin resin and ethylene / α-
The compatibility with the olefin random copolymer is deteriorated, and the mechanical properties tend to be deteriorated. On the other hand, if it exceeds 10% by weight, the flexibility and rubber elasticity of the finally obtained thermoplastic elastomer composition are deteriorated, which is not preferable.

Softening Agent The thermoplastic elastomer composition of the present invention comprises:
In addition to the component (d), a softening agent may be further added if necessary. The (e) softening agent used in the present invention (hereinafter also referred to as “(e) component”) is not particularly limited as long as it is a commonly used softening agent for rubber, for example, vegetable oil (palm oil, etc.), Esters of fatty acids and higher alcohols (phthalic acid diesters, etc.), phosphoric acid triesters, mineral oil-based hydrocarbons (paraffin-based mineral oil, naphthene-based mineral oil, aromatic mineral oil, etc.), and polybutene-based ,
Examples thereof include low molecular weight hydrocarbons such as polybutadiene type, and among them, mineral oil type hydrocarbons are preferable, and the weight average molecular weight is 300 to 2000, and particularly 500 to 15
Those having a molecular weight of 00 are preferred. A rubber softening agent composed of a mineral oil-based hydrocarbon is generally a mixture of an aromatic ring, a naphthene ring, and a paraffin chain, and the paraffin chain accounts for 50% or more of the total carbon number. Paraffin oil, naphthene ring carbon number 30 to 45% of total carbon number naphthene oil, aromatic ring carbon number 30% or more aromatic oil. In the present invention, paraffinic ones are preferable, and hydrogenated paraffinic ones are particularly preferable. Mineral oil-based hydrocarbons are 4
Kinematic viscosity at 0 ° C. is 20 to 800 cSt, especially 50 to 60
0 cSt, pour point -40 to 0 ° C, especially-
It is preferably 30 to 0 ° C.

The proportion of the component (e) in the thermoplastic elastomer composition is 150 parts by weight or less, preferably 100 parts by weight based on 100 parts by weight of the total amount of (a), (b), (c) and (d). It is below the weight part. If it exceeds 150 parts by weight, mechanical properties may deteriorate.

Crosslinking Agent The crosslinking agent used in the present invention crosslinks at least one ethylene / α-olefin random copolymer in the composition by a dynamic heat treatment at a temperature equal to or higher than the melting point of the olefin resin. Compound. Examples of such cross-linking agents include organic peroxides, phenol-based cross-linking agents, sulfur, sulfur compounds, p-quinone, derivatives of p-quinone dioxime, bismaleimide compounds, epoxy compounds, silane compounds, amino resins and the like. In particular, organic peroxides and phenolic crosslinking agents are preferable. Examples of the organic peroxide include 1,3-bis (t-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-
3,2,5-Dimethyl-2,5-bis (t-butylperoxy) hexene-3,2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, 2,2'-bis (T-Butylperoxy) -p-isopropylbenzene, dicumyl peroxide, di-t-butyl peroxide, t-butyl peroxide, p-menthane peroxide, 1,1-bis (t-butylperoxy) -3, 3,
5-trimethylcyclohexane, dilauroyl peroxide, diacetyl peroxide, t-butylperoxybenzoate, 2,4-dichlorobenzoyl peroxide, p-chlorobenzoyl peroxide, benzoyl peroxide, di (t-butylperoxy) peroxide Examples thereof include benzoate, n-butyl-4,4-bis (t-butylperoxy) valerate, and t-butylperoxyisopropyl carbonate. Among these organic peroxides, 1,3-bis (t-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3,2,5- Compounds having a relatively high decomposition temperature such as dimethyl-2,5-di (t-butylperoxy) hexane are preferred.

The above organic peroxides can be used alone or in admixture of two or more. In the present invention, a uniform and gentle crosslinking reaction can be carried out by using the organic peroxide in combination with a suitable crosslinking aid. Examples of such a cross-linking aid include powdered sulfur, colloidal sulfur, precipitated sulfur, insoluble sulfur, surface-treated sulfur, sulfur such as dipentamethylene thiuram tetrasulfide, or sulfur compounds; p-quinone oxime, p, p′-diamine. Oxime compounds such as benzoylquinone oxime; ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, tri Methylolpropane tri (meth) acrylate, diallyl phthalate, tetraallyloxyethane, triallyl cyanurate, N, N'-m
Examples thereof include polyfunctional monomers such as phenylene bismaleimide, N, N′-toluylene bismaleimide, maleic anhydride, divinylbenzene and zinc di (meth) acrylate. Among these crosslinking aids, p, p '
-Dibenzoylquinone oxime, N, N'-m-phenylene bismaleimide, divinylbenzene are preferred. In addition, N, N'-m-phenylene bismaleimide can act as a cross-linking agent alone. The cross-linking aids can be used alone or in admixture of two or more.

As the above-mentioned phenol-based cross-linking agent, a condensate of p-substituted phenol and an aldehyde (preferably formaldehyde) in the presence of an alkali catalyst, o-
Examples thereof include a condensate of a substituted phenol and an aldehyde, a condensate of an m-substituted phenol and an aldehyde, a condensate of a brominated alkylphenol and an aldehyde, and the like.
Of these, p-substituted phenol compounds are preferable. This p
-Substituted phenolic compounds are described in U.S. Pat. No. 328744.
As described in No. 0 and US Pat. No. 3,709,840, it has been conventionally used as a crosslinking agent for rubber.

The above-mentioned phenolic crosslinking agent can be used alone, but can also be used in combination with a crosslinking accelerator in order to control the crosslinking rate. Examples of such a crosslinking accelerator include metal halides such as stannous chloride and ferric chloride; organic halides such as chlorinated polypropylene, butyl bromide rubber, and chloroprene rubber. Further, it is more desirable to use a metal oxide such as zinc oxide and a dispersant such as stearic acid together.

When an organic peroxide is used as these cross-linking agent, the amount thereof is preferably 0.05 to 10 parts by weight, more preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the above component (a). It can be 5 parts by weight. If the amount of the organic peroxide used is less than 0.05 parts by weight, the degree of crosslinking may be insufficient and the rubber elasticity and mechanical strength of the finally obtained thermoplastic elastomer composition may be reduced. On the other hand, if the amount exceeds 10 parts by weight, the degree of crosslinking becomes excessively high, which tends to deteriorate the moldability and mechanical properties. When an organic peroxide is used as a crosslinking agent, the amount of the crosslinking aid used is preferably 10 parts by weight or less, more preferably 0.2 to 5 parts by weight, relative to 100 parts by weight of the component (a). Can be When the amount of the cross-linking aid used exceeds 10 parts by weight, the degree of cross-linking becomes excessively high, which tends to deteriorate the moldability and mechanical properties.

When a phenolic crosslinking agent is used as the crosslinking agent, the amount is preferably 0.2 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the component (a). You can If the amount of the phenol-based cross-linking agent used is less than 0.2 parts by weight, the adhesiveness at the time of injection fusion and the elastic recovery of the molded product obtained by injection fusion will tend to be reduced. On the other hand, if it exceeds 10 parts by weight, the extrusion processability and the injection processability of the thermoplastic elastomer composition tend to decrease.

The thermoplastic elastomer composition of the present invention comprises
The proportion of crosslinking is not particularly limited as long as it is dynamically heat-treated in the presence of a crosslinking agent, but (a) in the composition
Cyclohexane insoluble matter at 23 ℃ of the component is usually 20%
Or more, preferably 40%, more preferably 60% or more. If the cyclohexane insoluble content is less than 20%, the rubber elasticity and mechanical properties of the finally obtained thermoplastic elastomer composition may be deteriorated.

Method for Producing Thermoplastic Elastomer Composition The thermoplastic elastomer composition of the present invention may be obtained by any method. A predetermined amount of component (a), component (b),
A cross-linking agent, a cross-linking aid, etc. are added to the mixture containing the component (C), the component (D), or the component (B), the component (B), the component (C), the component (D), and the component (V). Then, the thermoplastic elastomer composition having excellent properties can be obtained by performing the dynamic heat treatment. In addition, a cross-linking agent and a cross-linking auxiliary agent are added to a mixture containing a predetermined amount of the component (a), the component (b), or the component (a), the component (b), and the component (e) to dynamically It is also possible to obtain a thermoplastic elastomer composition by mixing a predetermined amount of component (c) and component (d) after heat treatment.

The term "dynamic heat treatment" means to apply both shearing force and heating. This dynamic heat treatment can be performed using, for example, a melt-kneading device. Among these, as an apparatus capable of kneading, for example, an open type mixing roll, a non-open type Banbury mixer, a kneader, a continuous extruder; a single-screw extruder, a co-rotating continuous twin-screw extruder, a different extruder A device such as a direction rotation type continuous twin-screw kneader can be used. Further, the treatment performed by this kneading device may be a batch type or a continuous type.

The processing conditions of the dynamic heat treatment in the present invention are as follows:
The processing temperature is 120 to 350 ° C, depending on the melting point of the olefin resin used, the type of crosslinking agent, the kneading type, etc.
(More preferably 150 to 290 ° C.), and the treatment time is 20 seconds to 20 minutes (more preferably 30).
Seconds to 15 minutes). The shearing force applied is
The shear rate is 10 to 2000 / sec (more preferably 100
It is preferable to be set to 1000 / second).

In the thermoplastic elastomer composition of the present invention, various additives such as a lubricant, an antioxidant, a heat stabilizer, a weathering agent, a metal deactivator, an ultraviolet absorber, and the like may be added, if necessary.
Light stabilizers, stabilizers such as copper damage inhibitors, antibacterial and antifungal agents,
Dispersant, plasticizer, crystal nucleating agent, flame retardant, tackifier, foaming aid, titanium oxide, colorant such as carbon black, metal powder such as ferrite, glass fiber, inorganic fiber such as metal fiber, carbon fiber, Organic fibers such as aramid fibers, composite fibers, inorganic whiskers such as potassium titanate whiskers, glass beads, glass balloons, glass flakes, asbestos, mica, calcium carbonate, talc, silica, calcium silicate, hydrotalcite, kaolin, silica Filler such as algae earth, graphite, pumice, evo powder, cotton floc, cork powder, barium sulfate, fluororesin, polymer beads, etc. or a mixture thereof, filler such as polyolefin wax, cellulose powder, rubber powder, wood powder, low A molecular weight polymer or the like can be blended and used.

The thermoplastic elastomer composition of the present invention comprises
Injection molding, extrusion molding, hollow molding, compression molding, vacuum molding,
Processing by lamination molding, calendar molding, etc. becomes easy,
It is possible to obtain a thermoplastic elastomer molded article having excellent rubber elasticity and mechanical properties.

The thermoplastic elastomer composition of the present invention comprises
Taking advantage of its flexibility, excellent scratch resistance, and moldability, it is used for automobile bumpers that use conventional olefin thermoplastic elastomers, exterior moldings, wind seal gaskets, door seal gaskets, trunk seal gaskets, Roof side rails, emblems, inner panels, interior / exterior skin materials such as console boxes, weather strips, leather sheets that require scratch resistance, sealing materials for aircraft / ships, interior / exterior skin materials, civil engineering / construction Sealing material, interior / exterior skin material or waterproof sheet material, sealing material for general machinery / equipment, packing for light electrical parts or housing, medical device parts, electric wires,
It can be widely used for general processed goods such as daily sundries and sports equipment.

[0043]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited thereto. Parts and% in the examples and comparative examples are based on weight unless otherwise specified. Various components used in Examples and Comparative Examples are as follows.

(1) Random copolymer of ethylene / α-olefin (a-1) Ethylene / propylene / 5-ethylidene-2-norbornene terpolymer, ethylene content 66% by weight, 5-
3. Ethylidene-2-norbornene content 4.5% by weight, intrinsic viscosity [η] measured at 135 ° C. in decalin solvent = 4.
7. Mineral oil type softener (Product name "Diana Process Oil P
W380 ", manufactured by Idemitsu Kosan Co., Ltd.) 50% by weight (2) Olefin resin crystalline olefin resin (b-1); propylene / ethylene random copolymer, density 0.90 g / cm ³ , MFR
(Temperature 230 ° C, load 2.16kg) 23g / 10mi
n, manufactured by Nippon Polychem, product name "Novatech PP FL2"
5R "amorphous olefin resin (B-2); propylene /
1-butene amorphous copolymer; propylene content 71 mol%, melt viscosity 8000 cSt, density 0.87 g / c
m ³ , Mn6500, manufactured by Ube Industries, Ltd., product name "APAO
UT2780 "(3) (meth) acrylate resin (C-1) methyl methacrylate / methyl acrylate copolymer, density 1.19 g / cm ³ , MFR (temperature 230 ° C, load 3.
8 kg) 8 g / 10 min, product name “Parapet G” manufactured by Kuraray Co., Ltd. (4) Hydrogenated diene polymer (d-1) A hydrogenated diene polymer was synthesized by the method described below. Various measurements were based on the following methods.

It was measured by infrared analysis based on the absorption of a phenyl group having a vinyl aromatic compound content of 679 cm ^-1 . The vinyl bond content of the conjugated diene was calculated by the Morello method using infrared analysis. Hydrogenation rate Using carbon tetrachloride as a solvent, it was calculated from 90 MHz, ¹ H-NMR spectrum. Weight average molecular weight tetrahydrofuran was used as a solvent, and it was determined in terms of polystyrene using gel permeation chromatography (GPC) at 38 ° C.

Synthesis of hydrogenated diene polymer In an autoclave having an internal volume of 5 liters, 2.5 kg of cyclohexane, 15 g of tetrahydrofuran, 110 g of styrene (block A component), 0.55 of n-butyllithium.
g, and polymerization is performed at 50 ° C. until the polymerization conversion rate is 98% or more. Then, 220 g of 1,3-butadiene (block B component) is added and polymerization is performed until the polymerization conversion rate is 98% or more. Furthermore, 110 g of styrene (block A component) was added, and polymerization was performed until the polymerization conversion rate was 100%. After completion of the polymerization, the reaction solution was heated to 70 ° C. and 0.33 g of n-butyllithium and t-hydroxy-4-methyl-2-
0.61 g of pentanone, bis (cyclopentadienyl)
Titanium dichloride (0.21 g) and diethylaluminum chloride (0.76 g) were added, and the hydrogen pressure was 10 k.
Hydrogenation was carried out by reacting at g / cm ² for 1 hour. The reaction liquid was mixed with a large amount of methyl alcohol, and the precipitated solid was collected and dried to obtain a block copolymer. The obtained hydrogenated diene-based polymer (d-1) is an ABA type, the hydrogenation rate is 95%, the 1,2-vinyl bond content in the polybutadiene of the block B is 80%, Block A / Block B weight ratio is 50/50, weight average molecular weight is 1
It was 0,000.

(5) Crosslinking agent Crosslinking agent (f-1); 2,5-dimethyl-2,5-di (t
-Butylperoxy) hexane, manufactured by NOF CORPORATION, product name "Perhexa 25B-40" crosslinking aid (He-2); Sankyo Kasei Co., Ltd., divinylbenzene (purity 55%) crosslinking aid (He-3); large Uchi Shinko Chemical Co., Ltd., product name "Barnock PM" (6) Other additives Antiaging agent (to-1); Ciba Specialty Chemicals, product name "Irganox 1010" Silicone oil (organopolydimethylsiloxane)
(To-2); product name "SH-200 (100 cSt)" manufactured by Toray Dow Corning Silicone Co., Ltd.

Example 1 As an ethylene / α-olefin random copolymer,
(A-1) 80 parts, as an olefin resin, 10 parts of a crystalline olefin resin (b-1) and 5 parts of an amorphous olefin resin (b-2), as a (meth) acrylate resin,
(C-1) 5 parts, as a hydrogenated diene-based polymer,
1) 2 parts, 0.1 part of anti-aging agent and 0.2 part of silicone oil were put into a 10 liter double arm type pressure kneader (manufactured by Moriyama Co., Ltd.) heated to 150 ° C., and 20 at 40 rpm.
Kneaded for minutes. Then, the composition in the molten state is added to 180
Pelletization was performed using a feeder ruder (manufactured by Moriyama Co., Ltd.) set at 40 ° C. and 40 rpm. Furthermore, as a crosslinking agent, 0.5 parts of (He-1) and 0.5 parts of (F-3) were added to the obtained pellets as a crosslinking aid, and mixed for 30 seconds with a Henschel mixer, and then biaxial. Extruder (made by Ikegai, model "PC
M-45 ", same direction complete meshing type screw,
L / D, which is the ratio of the length L of the screw flight part to the screw diameter D, is 33.5),
It was extruded while performing a dynamic heat treatment under the condition of staying at 300 ° C. for 2 minutes at 300 ° C. to obtain a pellet-shaped dynamically crosslinkable thermoplastic elastomer composition.

Preparation of Thermoplastic Elastomer Test Pieces The obtained thermoplastic elastomer pellets were injection-molded using an injection molding machine (trade name N-100, manufactured by Nippon Steel Co., Ltd.) to obtain a thickness of 2 mm, a length of 120 mm and a width. A 120 mm sheet was prepared and subjected to various evaluations.

Evaluation of Thermoplastic Elastomer The fluidity of the obtained thermoplastic elastomer was measured as a melt flow rate at 230 ° C. under a load of 10 kg and is shown in Table 1. Further, using the molded sheet of the thermoplastic elastomer obtained, hardness, mechanical properties (tensile rupture strength,
Tensile elongation at break) and scratch resistance were evaluated by the following methods and are shown in Table 1. Hardness: Measured according to JIS-K6253 as an index of flexibility. Tensile breaking strength and tensile breaking elongation: JIS-K6251
It was measured according to. Compression set: JIS-K62 as an index of rubber elasticity
According to 62, the measurement conditions were 70 ° C. and 22 hours. Scratch resistance test 1; Using a Toyo Seiki Seisakusho Co., Ltd. Taber clutch tester, scan the surface of the formed sheet with a metal claw (tungsten carbide) to which a constant load (starting from 10 g load and increasing by 10 g) is applied. Then, the load value when the scratch was formed was measured. The larger the load value, the better the scratch resistance. Scratch resistance test 2; The surface of the molded sheet was rubbed with the nail of a thumb to visually judge the degree of scratching. ○: No scratches △: Light scratches ×: Deep scratches

Examples 2 to 4 and Comparative Examples 1 to 6 In the same proportions as in Example 1, pelletized crosslinked thermoplastic elastomer compositions and test pieces were prepared in the same manner as in Example 1. Table 1 shows the evaluation results of the obtained thermoplastic elastomer composition.

[0052]

[Table 1]

From Table 1, it can be seen that Examples 1 to 4 are excellent in scratch resistance, mechanical properties and rubber elasticity. Comparative Example 1
Nos. 3 to 3 have no (meth) acrylate resin and hydrogenated diene-based polymer, and therefore have poor scratch resistance. Since Comparative Example 4 does not have a hydrogenated diene polymer, it has poor mechanical properties. Further, Comparative Example 5 does not have a (meth) acrylate resin, and thus has poor scratch resistance. Since Comparative Example 6 is not crosslinked,
Poor mechanical properties, rubber elasticity and scratch resistance.

[0054]

EFFECTS OF THE INVENTION The thermoplastic elastomer composition of the present invention utilizes rubber elasticity, excellent scratch resistance and mechanical properties, and in particular weather strips and sponges for automobiles in which conventional olefinic thermoplastic elastomers are used. ,
Interior / exterior parts such as moldings, molded parts such as housings for light electrical parts, leather seat products that require scratch resistance,
It can be preferably used for

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08L 53/02 C08L 53/02 (72) Inventor Akihiko Morikawa 2-11-24 Tsukiji, Chuo-ku, Tokyo Jay F-Term (reference) in S-R Co., Ltd. BB122 BB151 BB172 BG043 BG053 BP014 EA047 EH107 EH146 EK037 ES017 EW046 FD025 FD026 GC00 GM00 GN00 GQ00

Claims (6)

[Claims] 1. An (a) ethylene / α-olefin random copolymer, (b) olefin resin, (c) (meth) acrylate resin, (d) hydrogenated diene polymer and, if necessary, ( (E) A thermoplastic elastomer composition containing a softening agent, wherein at least (a) and (b) are dynamically heat-treated in the presence of a crosslinking agent. 2. An ethylene / α-olefin random copolymer, (b) an olefin resin, (c) a (meth) acrylate resin, (d) a hydrogenated diene polymer, and, if necessary, (a) (E) A thermoplastic elastomer composition according to claim 1, which is obtained by dynamically heat-treating a mixture containing a softening agent in the presence of a crosslinking agent. 3. An ethylene / .alpha.-olefin random copolymer 20 to 95% by weight, (b) an olefin resin 3
~ 70% by weight, (C) (meth) acrylate resin 1-2
0 wt%, (d) 1-10 wt% hydrogenated diene polymer
(However, the total amount of (a), (b), (c), and (d) is 100 wt%), The thermoplastic elastomer composition according to claim 1 or 2. 4. The intrinsic viscosity [η] of the (a) ethylene / α-olefin random copolymer measured in decalin solvent at 135 ° C. is 2.0 to 6.8 dl / g. The thermoplastic elastomer composition according to any one of claims 1 to 3, which is characterized. 5. The (d) hydrogenated diene-based polymer comprises a polymer block (A) mainly containing a vinyl aromatic monomer and a polymer block (B) mainly containing a conjugated diene monomer. The thermoplastic elastomer composition according to any one of claims 1 to 4, which is a hydrogenated diene polymer contained. 6. A molded article containing the thermoplastic elastomer composition according to any one of claims 1 to 5.