JP2008150629A - Method for producing thermoplastic elastomer composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a thermoplastic elastomer composition that has good flexibility, exhibits excellent vibration-damping properties at a temperature of -60 to 30°C, and has excellent oil resistance and molding processability. <P>SOLUTION: The thermoplastic elastomer composition comprises (a) 100 pts.wt. of a block copolymer composed of at least two polymer blocks A to be made mainly from a vinyl aromatic compound and at least one polymer block B to be made mainly from a conjugated diene compound and/or a block copolymer to be obtained by hydrogenating this block copolymer, (b) 15-300 pts.wt. of a rubber softener selected from paraffin-based process oil and naphthene-based process oil (c) 0-130 pts.wt. of a peroxide-crosslinkable olefinic resin and/or a copolymer rubber containing this resin, (d) 0-130 pts.wt. of a peroxide decomposable olefinic resin and/or a copolymer rubber containing this resin, (e) 0.1-15 pts.wt. of thermally expandable microcapsules which expand at a temperature of 100-200°C, (f) 0-130 pts.wt. of a vinyl aromatic resin, (g) 0-100 pts.wt. of a hydrogenated petroleum resin, and (h) 0-100 pts.wt. of an inorganic filler. The composition does not contain any softener but (b), and not contain sulfur. The components (a) to (h) are melted and kneaded at a temperature of 150-250°C to expand the component (e) in the method for producing the thermoplastic elastomer composition. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a thermoplastic elastomer composition which is rich in flexibility, exhibits excellent vibration damping properties at −60 ° C. to 30 ° C., and is excellent in oil resistance and molding processability.

  In recent years, thermoplastic elastomers that are rubber-like materials that do not require a vulcanization process and that have the same molding processability as thermoplastic resins have been used in the fields of automotive parts, home appliance parts, electric wire coverings, footwear, sundries, etc Attention has been paid. Examples of such thermoplastic elastomers include various types of polymers such as polyolefin, polyurethane, polyester, polystyrene, and polyvinyl chloride.

  Among them, polystyrene-based thermoplastic elastomers such as styrene / butadiene block polymer (SBS), styrene / isoprene block polymer (SIS), and SIS derivatives and their hydrogenated products are rich in flexibility and have good rubber elasticity at room temperature. The thermoplastic elastomer composition obtained from these has excellent processability and is widely used as a substitute for vulcanized rubber.

  However, although SIS derivatives exhibit excellent vibration damping properties near room temperature, they are inferior in rubber elasticity and oil resistance, so their use is limited in fields that require heat resistance and oil resistance such as automotive applications and building material applications. The

  It is an object of the present invention to provide a thermoplastic elastomer composition which is rich in flexibility, exhibits excellent vibration damping properties at -60 ° C to 30 ° C, and has excellent oil resistance and molding processability, and a method for producing the same. To do.

  As a result of investigations, the present inventor has added a small amount of thermally expandable microcapsules to the styrene / conjugated diene block copolymer and / or hydrogenated derivative together with a non-aromatic rubber softener. It has been found that, when melt-kneaded at a temperature, a thermoplastic elastomer composition which is rich in flexibility and exhibits excellent oil resistance and molding processability, particularly excellent vibration damping properties at −60 ° C. to 80 ° C. can be obtained. Furthermore, when the styrene / conjugated diene-based block copolymer and / or the hydrogenated derivative is added as a part of a composition obtained by crosslinking a peroxide-crosslinked olefin resin and a copolymer rubber thereof, the above effect is obtained. Is even more remarkable.

That is, the present invention
(A) a block copolymer comprising at least two polymer blocks A mainly made from vinyl aromatic compounds and at least one polymer block B mainly made from conjugated diene compounds, and / or hydrogenating them 100 parts by weight of a block copolymer obtained by
(B) 15 to 300 parts by weight of a rubber softener selected from paraffinic process oil and naphthenic process oil;
(C) Peroxide-crosslinked olefin resin and / or copolymer rubber containing the same, 0 to 130 parts by weight,
(D) 0 to 130 parts by weight of peroxide-decomposable olefin resin and / or copolymer rubber containing the same
(E) 0.1 to 15 parts by weight of thermally expandable microcapsules that expand at a temperature of 100 to 200 ° C;
(F) 0 to 130 parts by weight of a vinyl aromatic resin,
(G) Hydrogenated petroleum resin 0-100 parts by weight, and (h) inorganic filler 0-100 parts by weight, no softener other than component (b), and no sulfur-containing thermoplastic elastomer composition The production method is characterized in that the components (a) to (h) are melt-kneaded at 150 to 250 ° C. to expand the component (e).

  Each component in the composition of the present invention will be described.

Component (a): Essential component The block copolymer is mainly made from a vinyl aromatic compound (hereinafter, may be mainly composed of a vinyl aromatic compound), and at least two polymer blocks A and a conjugated diene compound Or a block copolymer comprising at least one polymer block B (hereinafter, which may be mainly composed of a conjugated diene compound) or obtained by hydrogenating the block copolymer, for example, A -Vinyl aromatic compound-conjugated diene compound block copolymer having a structure such as -BA, BABA, ABBABA, or the like obtained by hydrogenation thereof It is. This block copolymer as a whole contains 5 to 60% by weight, preferably 20 to 50% by weight, of a vinyl aromatic compound. The polymer block A mainly composed of a vinyl aromatic compound is a homopolymer or copolymer made of 50% by weight or more, preferably 70% by weight or more of a vinyl aromatic compound and optional components such as a conjugated diene compound. It is a block. The polymer block B mainly composed of a conjugated diene compound is a homopolymer or copolymer block made of 50% by weight or more, preferably 70% by weight or more of a conjugated diene compound and optional components such as vinyl aromatic compounds. It is. Further, in the polymer block A mainly composed of these vinyl aromatic compounds or the polymer block B mainly composed of conjugated diene compounds, the distribution of units derived from the conjugated diene compounds or vinyl aromatic compounds in the molecular chain is random. , Tapered (in which the monomer component increases or decreases along the molecular chain), partly in block form, or any combination thereof. When there are two or more polymer blocks A mainly composed of vinyl aromatic compounds or polymer blocks B mainly composed of conjugated diene compounds, each polymer block has a different structure even if each has the same structure. There may be.

  As the vinyl aromatic compound constituting the block copolymer, for example, one or two or more types can be selected from styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene, etc. Among them, styrene is preferable. In addition, as the conjugated diene compound, for example, one or more kinds are selected from butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, etc., among which butadiene, isoprene, and these The combination of is preferable.

  In the polymer block B mainly composed of a conjugated diene compound, the microstructure can be arbitrarily selected. For example, in the polybutadiene block, the 1.2-microstructure is 20 to 50% by weight, preferably 25 to 45%. is there. In the polyisoprene block, 70 to 100% by weight of isoprene has a 1,4-microstructure, and at least 90% of the aliphatic double bonds derived from isoprene are hydrogenated.

Component (a) block copolymer is:
(A-1) Obtained by hydrogenating a block copolymer consisting of at least two polymer blocks A mainly made from vinyl aromatic compounds and at least one polymer block B mainly made from conjugated diene compounds. A hydrogenated block copolymer, wherein polymer block B contains a polyisoprene block, 70 to 100% by weight of isoprene has a 1,4-microstructure, and is an aliphatic double bond derived from isoprene. From 65 to 5 parts by weight of a hydrogenated block copolymer in which at least 90% is hydrogenated, and (a-2) at least two polymer blocks A mainly made from a vinyl aromatic compound, and a conjugated diene compound Hydrogenation obtained by hydrogenating a block copolymer consisting mainly of at least one polymer block B A lock copolymer,
Polymer block B comprises a polyisoprene block, the isoprene being a block copolymer in which 20 to 80% by weight has a 1,4-microstructure and 80 to 20% by weight has a 3,4-microstructure. Or a hydrogenated block copolymer of 35 to 95 parts by weight in which at least 80% of the aliphatic double bonds derived from isoprene of the block copolymer are hydrogenated.

  The above (a-1) is commercially available, for example, from Kuraray under the trade name Septon 4077. Further, (a-2) is also commercially available as, for example, Hibler VS and Hibler HVS from Kuraray.

  The number average molecular weight of the block copolymer is preferably 5,000 to 1,000,000, more preferably 10,000 to 500,000, still more preferably 100,000 to 300,000, and the molecular weight Distribution is 10 or less.

  The molecular structure of the block copolymer may be linear, branched, radial, or any combination thereof.

  Many methods for producing these block copolymers have been proposed. As typical methods, for example, a lithium catalyst or a Ziegler-type catalyst is prepared by the method described in Japanese Patent Publication No. 40-23798. It can be obtained by block polymerization in an inert medium. Any known method can be used for hydrogenation.

Component (b): Essential component The non-aromatic rubber softener is a non-aromatic mineral oil or a liquid or low molecular weight synthetic softener. The mineral oil softener generally used for rubber is a mixture of aromatic rings, naphthene rings, and paraffin chains, and the number of carbon atoms in the paraffin chain accounts for 50% or more of the total carbon number. Are classified as paraffinic, those having 30 to 40% of naphthenic ring carbon are called naphthenic, and those having 30% or more of aromatic carbon are called aromatic.

  The mineral oil rubber softeners used as the component (b) of the present invention are paraffinic and naphthenic in the above categories, and the aromatic softeners are dispersible with the component (a). It is not preferable. In particular, the component (b) of the present invention is preferably a paraffin-based one, and a paraffin-based one having a small aromatic ring component is particularly suitable.

  These non-aromatic rubber softeners have a dynamic viscosity at 37.8 ° C of 20 to 500 cst, a pour point of -10 to -15 ° C, and a flash point (COC) of 170 to 300 ° C. Is preferred.

  The amount of component (b) is 15 parts by weight or more, preferably 30 parts by weight or more, and 300 parts by weight or less, preferably 150 parts by weight or less with respect to 100 parts by weight of component (a). When the amount exceeds 300 parts by weight, the softening agent tends to bleed out, and the final product may be tacky, and the mechanical properties are also lowered. On the other hand, if it is less than 15 parts by weight, moldability becomes difficult and the flexibility of the resulting composition is lost.

Component (c): Optional component In the present invention, the peroxide-crosslinked olefin resin and / or copolymer rubber containing the same mainly undergoes a crosslinking reaction by heat treatment in the presence of peroxide, and its fluidity. Use the one that decreases. Examples of the olefin resin include high density polyethylene (low pressure method polyethylene), low density polyethylene (high pressure method polyethylene), linear low density polyethylene (ethylene and a small amount, preferably 1 to 10 mol% of butene-1, hexene-1, Copolymers such as octene-1 and other α-olefins), ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, ethylene-acrylic acid ester copolymers, etc., and one or more selected from these Is preferably used. Particularly preferred is an ethylene octene copolymer produced using a metallocene catalyst (single site catalyst) having a density of 0.90 g / cm ³ or less. These generally have a MFR of 0.1 to 5.0 g / 10 min, more preferably 0.3 to 1.0 g / 10 min at a temperature of 190 ° C. and a load of 2.16 kg.

  When component (c) is used, it is used in an amount of 130 parts by weight or less, preferably 80 parts by weight or less, based on 100 parts by weight of component (a). When the compounding amount of the component (c) exceeds 130 parts by weight, the heat resistance of the resulting elastomer composition is lost and the moldability is also deteriorated. Although the lower limit in the case of using is not specifically limited, Usually, 3 weight part or more, Preferably it is 10 weight part or more. A preferred blending amount is 0 to 80 parts by weight.

Component (d): Optional component The compounding of the peroxide-decomposable olefin resin and / or copolymer rubber containing it has the effect of improving the rubber dispersion of the resulting composition and improving the appearance of the molded product. .

  Peroxide-decomposable olefin resins and / or copolymer rubbers containing them are olefins that are thermally decomposed by heat treatment in the presence of peroxide to reduce molecular weight and increase fluidity when the resin is melted. System polymer or copolymer. For example, isotactic polypropylene or a copolymer of propylene and other α-olefins such as ethylene, 1-butene, 1-hexene, 4-methyl-1-pentene and the like can be mentioned.

  The crystallinity by DSC measurement (differential scanning calorimetry) of the homo-part of the peroxide-decomposable olefin resin and / or copolymer rubber containing the same is as follows: Tm is 150 ° C. to 167 ° C. The thing of the range of mg-83mJ / mg is preferable. The crystallinity can be estimated from Tm and ΔHm of DSC measurement. Outside the above range, the rubber elasticity of the resulting elastomer composition at 100 ° C. or higher is not improved.

  The MFR (JIS-K-7210, 190 ° C., 2.16 kg load) of the peroxide-decomposable olefin resin and / or copolymer rubber containing it is preferably used when it is added during dynamic crosslinking. It is in the range of 0.1 to 50 g / 10 minutes, preferably 0.5 to 20 g / 10 minutes. When adding after completion | finish of dynamic crosslinking, it is a thing of 0.1-200 g / 10min normally, Preferably it is the range of 0.5-60 g / 10min.

  When added at the time of dynamic crosslinking, if the MFR is less than 0.1 g / 10 min, the moldability of the resulting elastomer tends to be reduced, and if it exceeds 50 g / 10 min, the rubber elasticity of the resulting elastomer composition deteriorates. Tend to.

  When added after the completion of dynamic crosslinking, if the MFR is less than 0.1 g / 10 minutes, the moldability of the resulting elastomer is lowered, and if it exceeds 200 g / 10 minutes, the rubber elasticity of the resulting elastomer composition is deteriorated.

  When component (d) is used, it is used in an amount of 130 parts by weight or less, preferably 80 parts by weight or less, based on 100 parts by weight of component (a). When the compounding amount of component (d) exceeds 130 parts by weight, the hardness of the resulting elastomer composition becomes too high, the flexibility is lost, and a rubber-like product cannot be obtained. Moreover, the lower limit in the case of using is although it does not specifically limit, Usually, 3 weight part or more, Preferably it is 10 weight part or more. A preferred blending amount is 0 to 80 parts by weight.

Component (e): Essential component The thermally expandable microcapsule that thermally expands at a temperature of 100 to 200 ° C. is a component that is a feature for exhibiting the effects of the present invention. Here, as a thermally expandable microcapsule that expands at a temperature of 100 to 200 ° C., an average particle size of 1 to 50 μm is necessary. If the particle size is less than 1 μm, dispersion in rubber becomes insufficient. The strength of the molded product obtained from the composition of the invention is greatly reduced. Further, the expansion ratio is preferably 10 to 100 times, and if it is less than 10 times, a sufficient foaming ratio cannot be obtained, and if it exceeds 100 times, uniform fine cells are hardly obtained. As such a heat-expandable microcapsule, EXPANSEL having a vinylidene chloride / acrylonitrile copolymer as an outer shell and encapsulating isobutane is commercially available from EXPANSEL.

  The compounding amount of component (e) is 0.1 parts by weight or more, preferably 1 part by weight or more and 15 parts by weight or less, preferably 10 parts by weight or less with respect to 100 parts by weight of component (a). Furthermore, it is preferably selected in the range of 1 to 6 parts by weight. If the component (e) is less than 0.1 part by weight, a sufficient effect is not exhibited, and if it exceeds 15 parts by weight, the rubber elasticity of the molded product obtained from the composition of the present invention is deteriorated and the mechanical properties are lowered. . Further, when the expansion temperature is 100 ° C. or lower, the rubber elasticity is deteriorated, and when it exceeds 200 ° C., the productivity is deteriorated and the appearance of the molded product is also deteriorated.

Component (f): Optional component Examples of the vinyl aromatic resin include polystyrene, rubber-modified polystyrene (impact polystyrene), styrene-α-methylstyrene copolymer, styrene-paramethylstyrene copolymer, and styrene-acrylic acid. A rubber-acrylonitrile copolymer, a styrene-maleic anhydride copolymer, and the like can be given, and one or more of these can be selected. The rubber component of rubber-modified polystyrene is 2 to 15%. Of these, polystyrene is preferred. A melt flow rate of 0.5 to 60 g / 10 min (measured at 200 ° C. and a load of 5.0 kg) is preferable. Furthermore, the thing of a weight average molecular weight 10 < ³ > -10 < ⁷ > is preferable.

  When component (f) is used, it is used in an amount of 130 parts by weight or less, preferably 80 parts by weight or less, based on 100 parts by weight of component (a). When the amount exceeds 130 parts by weight, the hardness of the resulting elastomer composition becomes too high, the flexibility is lost, and a rubber-like product cannot be obtained. Moreover, the lower limit in the case of using is although it does not specifically limit, Usually, it is 3 weight part or more. A preferred blending amount is 0 to 80 parts by weight.

Component (g): Optional component A hydrogenated petroleum resin can be blended as required. When hydrogenated petroleum resin is blended, the balance between flexibility and stickiness is good, and there is an effect that there is no stickiness although there is flexibility. Examples of the hydrogenated petroleum resin used in the present invention include hydrogenated petroleum resins such as hydrogenated aliphatic petroleum resins, hydrogenated aromatic petroleum resins, hydrogenated copolymerized petroleum resins, and hydrogenated alicyclic petroleum resins. And hydrogenated terpene resins.
The hydrogenated petroleum resin can be obtained by hydrogenating a petroleum resin produced by a conventional method by a conventional method.

The petroleum resin is a resinous material obtained in various processes of the petroleum refining industry and the petrochemical industry, or copolymerized from these processes, particularly unsaturated hydrocarbons obtained in the decomposition process of naphtha as a raw material. It refers to the resulting resin. For example, aliphatic petroleum resins to the C ₅ fraction as a main raw material, aromatic petroleum resin a C ₉ fraction as a main raw material, those copolymerized petroleum resins, are hydrogen Kaabura alicyclic petroleum resin Among them, a cyclopentadiene compound and a vinyl aromatic compound are copolymerized to form a hydrogenated alicyclic petroleum resin, and among them, a cyclopentadiene compound and a vinyl aromatic compound are copolymerized. Hydrogenated ones are preferable.

  When component (g) is used, it is used in an amount of 100 parts by weight or less, preferably 80 parts by weight or less, based on 100 parts by weight of component (a). When the amount exceeds 100 parts by weight, the surface property of the molded product is deteriorated. Moreover, the lower limit in the case of using is although it does not specifically limit, Usually, it is 1 weight part or more. A preferred blending amount is 0 to 80 parts by weight.

Component (h): Optional component An inorganic filler can be blended as required. In addition to the effect of improving some physical properties such as compression set of molded articles, the inorganic filler has an economic advantage due to an increase in the amount. Examples of the inorganic filler used include calcium carbonate, talc, magnesium hydroxide, mica, clay, barium sulfate, natural silicic acid, synthetic silicic acid (white carbon), titanium oxide, and carbon black. Of these, calcium carbonate and talc are particularly preferable.

  When component (h) is used, it is used in an amount of 100 parts by weight or less, preferably 60 parts by weight or less, based on 100 parts by weight of component (a). When the amount exceeds 100 parts by weight, the mechanical strength of the resulting elastomer composition is remarkably lowered, the hardness is increased, the flexibility is lost, and a rubber-like product cannot be obtained. Moreover, the lower limit in the case of using is although it does not specifically limit, Usually, it is 5 weight part or more. A preferred blending amount is 0 to 50 parts by weight.

  As a component that can be blended in addition to the above-described components, a styrene resin composition can be used for the purpose of controlling fluidity.

  In addition to the above-mentioned components, the composition of the present invention may have various anti-blocking agents, sealability improvers, heat stabilizers, antioxidants, ultraviolet absorbers, lubricants, crystal nucleating agents, and colorants depending on the application. Etc. can also be contained.

  The above-described composition can be produced by melting and kneading each component at a temperature of 150 to 250 ° C, preferably 180 to 240 ° C. By melt-kneading at the above temperature, a composition in which the component (e) is expanded is obtained. Any conventional melt-kneading technique and apparatus (single- or twin-screw extruder, roll, Banbury mixer, various kneaders, etc.) can be used. In particular, when a twin screw extruder or Banbury mixer having an L / D of 47 or more is used, there is an advantage that all steps can be performed continuously.

  When the composition contains the component (d), for example, when it is contained in an amount of 3 to 130 parts by weight, particularly 10 to 130 parts by weight with respect to 100 parts by weight of the component (a), basically, two steps are performed. The following production method comprising:

  That is, the total amount of component (a) and component (b), at least part of component (d), the total amount of component (e), and the total amount of component (c) if there is component (c) In the presence of oxide, the mixture is melt-kneaded at a temperature of 150 to 250 ° C. to cause crosslinking, and the component (e) is expanded (first step). Melt-knead at a temperature of 2 ° C. (second step). Ingredients (f) to (h) can be blended at any point in either the first step or the second step.

  First, in the first step, the specific component is melt-kneaded in the presence of an organic peroxide. Component (d) is preferably used in the first step in an amount of at least 10 parts by weight. When the optional components (c) and (f) to (h) are used, it is preferable to melt and knead the whole amount here. The melt kneading is performed at a temperature of 150 to 250 ° C, preferably 180 to 240 ° C. As the apparatus, any of the above-described melt kneading apparatuses can be used.

  Examples of the organic peroxide include dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, 2,5-dimethyl-2, 5-di (tert-butylperoxy) hexyne-3,2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3,1,3-bis (tert-butylperoxyisopropyl) benzene, 1 , 1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane, n-butyl-4,4-bis (tert-butylperoxy) valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butyl peroxybenzoate, ert- butyl peroxy isopropyl carbonate, diacetyl peroxide, lauroyl peroxide, tert- butyl cumyl like can be mentioned oxide, the combined use of these alone, or two or more kinds. Of these, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, 2,5-dimethyl-2,5-di in terms of odor, colorability, and scorch stability. (Tert-Butylperoxy) hexyne-3 is most preferred.

  Multi-functionality such as divinylbenzene, triallyl cyanurate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, allyl methacrylate in the crosslinking treatment with the organic peroxide. Multifunctional vinyl monomers such as functional methacrylate monomers, vinyl butyrate or vinyl stearate can be formulated as crosslinking aids. By such a compound, a uniform and efficient crosslinking reaction can be expected.

  In particular, in the present invention, when triethylene glycol dimethacrylate is used, it is easy to handle, and when component (c) peroxide-crosslinked olefin resin and / or copolymer rubber containing it is used, component (c) It has good compatibility with water, has a solubilizing action of peroxide, and acts as a dispersing aid for peroxide. Therefore, the cross-linking effect by heat treatment is uniform and effective, and the movement is balanced between hardness and rubber elasticity. This is most preferable for the reason that a cross-linked thermoplastic elastomer is obtained.

  Moreover, in a 1st process, an antioxidant can be mix | blended depending on the case. Antioxidants used here include 2,6-di-tert-p-butyl-p-cresol, 2,6-di-tert-butylphenol, 2,4-dimethyl-6-tert-butylphenol, 4, Examples thereof include phenolic antioxidants such as 4-dihydroxydiphenyl and tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, phosphite antioxidants, thioether antioxidants, and the like. Of these, phenolic antioxidants and phosphite antioxidants are preferred.

  For example, the peroxide, the crosslinking aid, or the antioxidant is used in the following amounts with respect to 100 parts by weight of the component (a). 0.1 to 1.5 parts by weight of peroxide, preferably 0.1 to 1.0 parts by weight; 0.1 to 3.5 parts by weight of crosslinking aid, preferably 0.1 to 2.5 parts by weight; 3 parts by weight or less of the oxidizing agent, preferably 1 part by weight or less. However, in actuality, it is determined in consideration of the blending ratio of the components (a) to (h), in particular, the degree of crosslinking that affects the quality of the resulting dynamically crosslinked thermoplastic elastomer.

  Next, in the reaction of the second step, the cross-linked product obtained in the first step and the remainder of the component (d) are blended and melt-kneaded. The melt kneading is performed at a temperature of 150 to 250 ° C, preferably 180 to 240 ° C. As the apparatus, any of the above-described melt kneading apparatuses can be used.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further, this invention is not limited to this.

The evaluation methods used in Examples and Comparative Examples were as follows.
1) Hardness In accordance with JIS K 7215, a 6.3 mm thick press sheet was used as a test piece. The hardness after 15 seconds was measured.
2) Tensile strength In accordance with JIS K 6301, a 1 mm thick press sheet was used as a test piece by punching it into a No. 3 type with a dumbbell. The tensile speed was 500 mm / min.
3) Tensile elongation In accordance with JIS K 6301, the test piece was a 1 mm thick press sheet punched into a No. 3 shape with a dumbbell. The tensile speed was 500 mm / min.
4) 100% modulus In accordance with JIS K 6301, the test piece was a 1 mm thick press sheet punched into No. 3 type with a dumbbell. The tensile speed was 500 mm / min.
5) Compression set In accordance with JIS K 6262, a 6.3 mm thick press sheet was used as a test piece. The measurement was performed at 100 ° C. for 22 hours under the conditions of 25% deformation.
6) Formability A sheet of 12.5 × 13.5 × 1 mm was molded under the following conditions using an injection molding machine with a clamping pressure of 120 tons.

Molding temperature 220 ° C
Mold temperature 40 ℃
Injection speed 55mm / sec Injection pressure 1400kg / cm ²
Holding pressure 400 kg / cm ²
Injection time: 6 seconds Cooling time: 45 seconds Evaluation was made based on the presence or absence of delamination, deformation and the presence of a flow mark that significantly deteriorated the appearance.
7) Bleed-out property When the above molded product is compressed 50% in an environment of 100 ° C x 22 hours, no bleed or bloom of low molecular weight is seen, and there is no stickiness even when touched by hand. The properties were considered good.
8) Damping performance (measurement of tan δ)
Test piece (dimensions: 10 mm × 3 mm × 50 mm, measurement part length: 20 mm):
Press molding was performed under the conditions of a pressing temperature of 200 ° C., a preheating time of 3 minutes, a pressing time of 2 minutes, and a pressing pressure of 50 kg / cm ² .
The test piece was mounted on a chuck of the following measuring apparatus, and tan δ was measured under the following measurement conditions:
Measuring device: Seiko Instruments Inc., DMS110 bending module,
Measurement conditions: −60 to 100 ° C., bending (rectangular section) mode, frequency 10 Hz.
9) Rebound resilience: Based on BS903, a 4 mm thick press sheet was used as a test piece.

The following substances were used as each component.
Component (a):
(A-1) Septon 4077 manufactured by Kuraray Co., Ltd.
Styrene content: 30% by weight, isoprene content: 70% by weight
Number average molecular weight: 260,000, weight average molecular weight: 320,000
Molecular weight distribution: 1.23, hydrogenation rate: 90% or more,
(A-2) Kuraray Co., Ltd. Hibler VS-1
Styrene content: 20% by weight, isoprene content: 70% by weight
Hydrogenation rate: 0%
Ingredient (b): Idemitsu Kosan Diana Process Oil PW-90, Type: Paraffinic oil
Component (c): peroxide cross-linked olefin resin, manufactured by Sumitomo Chemical Co., Ltd., Bond Fast BF-E, type: epoxy-containing ethylene copolymer, MFR: 3 g / 10 min (190 ° C., 2.16 kg load),
Component (d): peroxide-decomposable olefin resin, manufactured by Mitsui Petrochemical Co., Ltd., PP CJ700, type: polypropylene homopolymer, crystallinity: Tm 166 ° C., ΔHm 82 mJ / mg, MFR: 2.5 g / 10 min (190 ° C, 2.16 kg load),
Ingredient (e): EXPANSEL 092DU120 manufactured by EXPANSEL
Component (f): Polystyrene homopolymer, GP-1 manufactured by Denki Kagaku Kogyo, MFR: 6.4 g / 10 min (200 ° C., 5 kg load),
Component (g): Idemitsu Petrochemical P-140, Type: Hydrogenated petroleum resin C5-Aromatic copolymer hydrogenated resin,
Ingredient (h): Sankyo Seisaku Co., Ltd. RS400, Type: Calcium Carbonate Peroxide: Kayaku Hexa AD Kaya Hexa AD,
Crosslinking aid: NK ester 3G made by Shin-Nakamura Chemical Co., Ltd. Type: triethylene glycol dimethacrylate

Examples 1-34 and Comparative Examples 1-10
Examples 1-8 and 13-31 and 34 and Comparative Examples 1-3 and 5-9 melt-kneaded each component collectively. The melt kneading conditions were as follows: using a twin screw extruder (L / D = 62.5), kneading temperature 180-240 ° C. and screw rotation speed 350 rpm.

  Examples 9-12, 32 and 33 and Comparative Examples 4 and 10 produced compositions in two stages. First, 10 parts by weight of component (d) and the total amount of other components were melt-kneaded (first step), then the remainder of component (d) was added from the middle of the extruder and melt-kneaded (second step). . The melt-kneading conditions in each step were the same as the above-described batch melt-kneading.

  About the obtained resin composition, an above-described test was done and the result is shown in Tables 1-6.

  The thermoplastic elastomer composition of the present invention is rich in flexibility, exhibits excellent vibration damping properties at −60 ° C. to 30 ° C., and is excellent in oil resistance and moldability. Therefore, it is very useful especially in fields that require heat resistance and oil resistance such as automobile use and building material use.

Claims (3)

(A) a block copolymer comprising at least two polymer blocks A mainly made from vinyl aromatic compounds and at least one polymer block B mainly made from conjugated diene compounds, and / or hydrogenating them 100 parts by weight of a block copolymer obtained by
(B) 15 to 300 parts by weight of a rubber softener selected from paraffinic process oil and naphthenic process oil;
(C) Peroxide-crosslinked olefin resin and / or copolymer rubber containing the same, 0 to 130 parts by weight,
(D) 0 to 130 parts by weight of peroxide-decomposable olefin resin and / or copolymer rubber containing the same
(E) 0.1 to 15 parts by weight of thermally expandable microcapsules that expand at a temperature of 100 to 200 ° C;
(F) 0 to 130 parts by weight of a vinyl aromatic resin,
(G) Hydrogenated petroleum resin 0-100 parts by weight, and (h) inorganic filler 0-100 parts by weight, no softener other than component (b), and no sulfur-containing thermoplastic elastomer composition A production method comprising: expanding components (e) by melt-kneading components (a) to (h) at 150 to 250 ° C. The method according to claim 1, wherein the melt kneading is performed in the presence of an organic peroxide. The method according to claim 2, wherein melt kneading is carried out in the presence of a crosslinking aid.