JP2005281489A - Thermoplastic elastomer composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic elastomer composition that shows reduced oil bleed, has high mechanical strength, transparency and flexibility, further good molding properties in the press molding, injection molding, dipping molding and the like. <P>SOLUTION: This thermoplastic elastomer composition has excellent transparency and flexibility and comprises (a) 100 pts.wt. of fully or partially hydrogenated block copolymer, (b) 75 to 400 pts.wt. of non-aromatic rubber softening agent, (c) 3 to 60 pts.wt. of petroleum resin, when necessary, (d) 1 to 200 pts.wt. of turpentine oil. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thermoplastic elastomer composition excellent in transparency and flexibility, and particularly relates to a thermoplastic elastomer composition excellent in transparency and flexibility having little oil bleed and excellent mechanical strength and molding processability.

  Conventionally, a thermoplastic elastomer resin composition having a predetermined hardness has been obtained by adding oil as a softening agent and olefin resin as a resin component to a styrene resin composition or an ethylene-propylene resin composition, Paraffin oil is often used as the oil. However, the addition of oil makes it possible to reduce the hardness, but since a resin having a lower molecular weight than other resin components is used, the heat resistance, weather resistance, mechanical strength, wear resistance, etc. are reduced. .

  In addition, when obtaining a very soft thermoplastic resin composition, there is a problem that oil bleeding occurs on the surface of the molded product, and a satisfactory thermoplastic resin composition cannot be obtained. That is, in general, the amount of oil that can be absorbed by the thermoplastic resin composition has an upper limit of oil amount / thermoplastic resin composition = a little more than three times, and when more oil is added, oil bleeding occurs. Moreover, if the oil amount / thermoplastic resin composition amount = more than three times the upper limit, pelletization becomes difficult. Further, when transparency is required, the combination of the thermoplastic resins to be added is considerably limited, and it becomes difficult to adjust the balance between molding processability and various physical properties.

  Furthermore, a composition composed of styrene-based thermoplastic elastomers and paraffins is disclosed as a gel elastomer (see, for example, Patent Document 1), but a high temperature is required during production and heat dissolution. For this reason, there is also a problem that the paraffins ooze out and feel oily because the gel is browned and solidified immediately when molded, the handling property is insufficient and difficult to handle, and the structural strength of the gel is insufficient. It was.

  In order to solve the above problems, isopropyl myristate, isopropyl palmitate, butyl stearate, and isononyl isononanoate are blended to lower the melting temperature of styrenic thermoplastic elastomers. An invention has been disclosed in which the nature is increased and the feel is refreshed (see, for example, Patent Document 2). However, although the effect of improving the hue is sufficiently exerted, the oiliness is still strong, and the improvement of oiliness is insufficient particularly in the field where a refreshing feel such as foot care use is required.

In order to improve such oily feeling, etc., the effect of addition of fatty acid esters was studied, and the size of the alkyl group existing between the ester groups and the ratio of branching influence the effect of adding the fatty acid ester. A gel elastomer composition composed of styrene-based thermoplastic elastomers, paraffins, and fatty acid esters (cetyl 2-ethylhexylate) has been proposed (for example, see Patent Document 3). Furthermore, as a gel-like composition imparted with shock absorbing performance, a gel-like composition obtained by swelling a triblock styrene elastomer in a softening agent (see, for example, Patent Document 4), a triblock styrene elastomer and diblock A gel-like composition (for example, see Patent Documents 5 and 6) composed of a type styrene elastomer and a softening agent has been proposed. However, these gel compositions also have a problem that the balance of transparency, oil bleed, and moldability is remarkably inferior.
Further, in all the above prior arts, particularly in the case of injection molding, the cooling time is abnormally long, and in some cases, there are cases where the cooling time is about 25 minutes, and the productivity is remarkably inferior.

  Therefore, the present inventors have a softening agent for non-aromatic hydrocarbon rubber as a super-soft composition which is rich in flexibility, excellent in heat distortion characteristics, mechanical strength, oil resistance and molding processability and has no stickiness, Compositions containing organic peroxides, crosslinking aids, thermoplastic resins as optional components (see, for example, Patent Document 7), styrenic thermoplastic elastomers, softeners for non-aromatic hydrocarbon rubbers, vinyl aromatic resins , A hydrogenated petroleum resin, an acrylic processing aid, and a composition containing an organic peroxide (see, for example, Patent Document 8), easy handling, no oil bleed, and excellent mechanical strength And a thermoplastic gel-like composition having wear resistance, a heat containing non-aromatic hydrocarbon rubber softener, hydrogenated styrenic thermoplastic elastomer, amorphous polyolefin Plastic gel composition (for example, see Patent Document 9.) Have proposed. However, a thermoplastic elastomer composition excellent in transparency and molding processability and excellent in balance between molding processability and various physical properties has not been obtained.

Furthermore, attempts have been made to improve styrenic thermoplastic elastomers using an adhesive resin such as petroleum resin. For example, a pressure-sensitive adhesive composition in which a tackifier such as a terpene resin is blended with a partially hydrogenated block copolymer in which a conjugated diene moiety is partially hydrogenated (see, for example, Patent Document 10), a styrene block. A hot melt pressure-sensitive adhesive composition in which an aromatic petroleum resin obtained by petroleum decomposition is blended with a copolymer (see, for example, Patent Document 11), and a tackifier having a styrene block copolymer made of a petroleum resin or the like. A hot-melt adhesive (for example, see Patent Document 12), a pressure-sensitive adhesive composition in which an aliphatic or alicyclic adhesive resin or the like is blended with a styrene block copolymer (for example, see Patent Document 13). ), Stretch film for food packaging made of hydrogenated styrene block copolymer, petroleum resin, polypropylene resin (see, for example, Patent Documents 14 to 15). There has been disclosed. However, all of the techniques described in these patent documents merely use tackifying properties such as petroleum resins, have few oil bleeds, have excellent mechanical strength, transparency, flexibility, and moldability. An elastomer resin composition excellent in the above was not disclosed.
US Pat. No. 4,369,284 US Pat. No. 5,558,872 JP 2000-281850 A JP-A-8-73696 JP 2001-151979 A JP 2001-151980 A JP 2001-311012 A JP 2000-34389 A JP 2003-183506 A JP-A-6-145626 JP-A-6-271826 JP-A-8-283865 Japanese Patent Publication No. 7-5873 JP-A-9-156665 Japanese Patent Laid-Open No. 9-165491 JP-A-9-165492

  In view of the above problems, the present invention has less oil bleed and has excellent mechanical strength, transparency, flexibility, and transparency having molding processability such as extrusion molding, injection molding, dipping molding, An object is to provide a thermoplastic elastomer composition having excellent flexibility.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor blended a hydrogenated or partially hydrogenated block copolymer and a petroleum resin with a non-aromatic rubber softener and, if necessary, a terpene oil. It is found that a thermoplastic elastomer composition can be obtained by heat treatment, which can supply pellets, can be molded in various ways, is transparent, has no oil bleed, and is a very soft elastic body. The invention has been completed.

That is, according to the first invention of the present invention, (a) 100 parts by weight of hydrogenated or partially hydrogenated block copolymer,
There is provided a thermoplastic elastomer composition comprising (b) 75 to 400 parts by weight of a non-aromatic rubber softener and (c) 3 to 60 parts by weight of a petroleum resin.

  According to the second invention of the present invention, there is provided a thermoplastic elastomer composition characterized in that in the first invention, (d) 1 to 200 parts by weight of a terpene oil is further contained.

  According to the third invention of the present invention, in the first or second invention, (a) the aromatic vinyl compound content of the hydrogenated or partially hydrogenated block copolymer is 15 to 45% by weight. A thermoplastic elastomer composition is provided.

  The thermoplastic elastomer composition of the present invention has less oil bleed, has excellent mechanical strength and transparency, is excellent in molding processability such as extrusion molding, injection molding and dipping molding, and is excellent in transparency and flexibility. It is a thermoplastic elastomer composition.

The components, production methods, and uses constituting the present invention will be described in detail below.
1. Component (a) Hydrogenated or Partially Hydrogenated Block Copolymer Component of Thermoplastic Elastomer Composition The hydrogenated or partially hydrogenated block copolymer component (a) used in the thermoplastic elastomer composition of the present invention is rubber elastic.・ Apply mechanical properties.
The hydrogenated block copolymer is a block copolymer comprising at least one polymer block A mainly composed of an aromatic vinyl compound and at least one polymer block B mainly composed of a conjugated diene compound. Mention may be made, for example, of hydrogenated block copolymers or conjugated diene block copolymers obtained by hydrogenation.
A block comprising at least one polymer block A mainly composed of an aromatic vinyl compound and at least one polymer block B mainly composed of a conjugated diene compound that can be used in the thermoplastic elastomer composition of the present invention. The hydrogenated block copolymer component obtained by hydrogenating the copolymer contains at least one polymer block A mainly composed of an aromatic vinyl compound and at least one polymer block B mainly composed of a conjugated diene compound. It is a polymer obtained by hydrogenating one block copolymer. For example, a hydrogenated block copolymer of an aromatic vinyl compound-conjugated diene compound having a structure such as A-B, A-B-A, B-A-B-A, or A-B-A-B-A Is obtained.

  The polymer block A mainly composed of an aromatic vinyl compound may be a polymer composed only of an aromatic vinyl compound or a copolymer of an aromatic vinyl compound and less than 50% by weight of a conjugated diene compound. The polymer block B mainly composed of a conjugated diene compound may be a polymer composed solely of a conjugated diene compound or a copolymer of a conjugated diene compound and less than 50% by weight of an aromatic vinyl compound.

  As the aromatic vinyl compound constituting the hydrogenated block copolymer, for example, one or more kinds can be selected from styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene, etc. Styrene is preferred. In addition, as the conjugated diene compound, for example, one or two or more kinds are selected from butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, etc., among which butadiene, isoprene and These combinations are preferred.

  Hydrogenated block obtained by hydrogenating a block copolymer comprising at least one polymer block A mainly composed of an aromatic vinyl compound and at least one polymer block B mainly composed of a conjugated diene compound In the polymer block B mainly composed of a conjugated diene compound, the hydrogenation rate of the polymer component is arbitrary, but it is preferably 50% or more, more preferably 55% or more, and still more preferably 60% or more. Further, the microstructure is arbitrary. For example, when the block B is composed of butadiene alone, the polybutadiene block preferably has a 1,2-microstructure of 20 to 50% by weight, particularly preferably 25 to 45%. % By weight. Moreover, the thing which hydrogenated the 1, 2- bond selectively may be sufficient. When block B is composed of a mixture of isoprene and butadiene, the 1,2-microstructure is preferably less than 50%, more preferably less than 25%, and even more preferably less than 15%.

  When block B is composed of isoprene alone, in the polyisoprene block, preferably 70 to 100% by weight of isoprene has a 1,4-microstructure, and preferably at least aliphatic double bonds derived from isoprene. 90% hydrogenated is preferred.

  When a hydrogenated block copolymer is used depending on the application, the above hydrogenated product can be suitably used according to the application.

  Moreover, it is preferable that the polymer block A exists in the ratio of 5-70 weight% of the whole component. Furthermore, the weight average molecular weight of the whole component is 350,000 or less, Preferably it is 30,000-250,000. If the weight average molecular weight exceeds 350,000, the moldability deteriorates.

  Specific examples of the hydrogenated block polymer component include styrene-ethylene / butadiene copolymer (SEB), styrene-ethylene / propylene copolymer (SEP), styrene-ethylene / butadiene-styrene copolymer (SEBS), Styrene-ethylene-propylene-styrene copolymer (SEPS), styrene-ethylene-ethylene-propylene-styrene copolymer (SEEPS), styrene-butadiene-butylene-styrene copolymer (partially hydrogenated styrene-butadiene-styrene copolymer) Polymer, SBBS), partially hydrogenated styrene-isoprene-styrene copolymer, partially hydrogenated styrene-isoprene / butadiene-styrene copolymer, and the like. In the present invention, the hydrogenated product of the aromatic vinyl compound-conjugated diene compound block copolymer may be used alone or in combination of two or more.

  A block obtained by hydrogenating a block copolymer comprising at least one polymer block A mainly composed of these aromatic vinyl compounds and at least one polymer block B mainly composed of a conjugated diene compound. As a method for producing a copolymer, a number of methods have been proposed. As a typical method, for example, a lithium catalyst or a Ziegler type catalyst is used by the method described in JP-B-40-23798. It can be obtained by block polymerization in an inert medium. Such a hydrogenation treatment of the block copolymer can be performed by a known method in the presence of a hydrogenation catalyst in an inert solvent.

Examples of the hydrogenated conjugated diene block copolymer that can be used in the thermoplastic elastomer composition of the present invention include, for example, a crystalline ethylene block obtained by hydrogenating a butadiene block copolymer and an amorphous block. And a block copolymer (CEBC) having a functional ethylene-butene block. In the present invention, the hydrogenated product of the conjugated diene compound block copolymer may be used alone or in combination of two or more.
Moreover, the weight average molecular weight of the hydrogenated product of the conjugated diene block copolymer is 350,000 or less, preferably 30,000 to 250,000. If the weight average molecular weight exceeds 350,000, the moldability deteriorates.

  As a component (a), a block copolymer comprising at least one polymer block A mainly composed of an aromatic vinyl compound and at least one polymer block B mainly composed of a conjugated diene compound is hydrogenated. Hydrogenated block copolymer or conjugated diene block copolymer hydrogenated product obtained by the above, and a block having a crystalline ethylene block and an amorphous ethylene-butene block obtained by hydrogenating a block copolymer of butadiene When the copolymer (CEBC) is used in combination, the proportion of the aromatic vinyl compound contained in the entire component (a) is preferably 15 to 45% by weight, more preferably 20 to 40% by weight. When the aromatic vinyl compound exceeds 45% by weight, the flexibility is lowered, and oil bleed, transparency and moldability become remarkable. On the other hand, if it is less than 15% by weight, the mechanical properties are lowered, and the oil bleeding property and tackiness become remarkable.

  Further, at least one polymer block A mainly composed of an aromatic vinyl compound containing 15 to 45% by weight of an aromatic vinyl compound as component (a) and at least one polymer block mainly composed of a conjugated diene compound It contains an aromatic vinyl compound at a higher rate than when a hydrogenated block copolymer obtained by hydrogenating a block copolymer consisting of B or a hydrogenated product of a conjugated diene block copolymer is used alone. Hydrogenated block obtained by hydrogenating a block copolymer comprising at least one polymer block A mainly composed of an aromatic vinyl compound and at least one polymer block B mainly composed of a conjugated diene compound Crystalline ethylene obtained by hydrogenation of hydrogenated copolymer or conjugated diene block copolymer and butadiene block copolymer A block copolymer (CEBC) having a lock and an amorphous ethylene-butene block is used in combination, and the proportion of the aromatic vinyl compound contained in the entire component (a) is 15 to 45% by weight. And more preferable.

(B) Non-aromatic rubber softener The non-aromatic hydrocarbon rubber softener (b) used in the thermoplastic elastomer composition of the present invention has a function of adjusting the hardness of the resulting composition and moldability. It is a component that fulfills the function of improvement.
A composition that is particularly flexible and excellent in transparency by adding a large amount of the component (b) of 75 to 400 parts by weight to the component (a) as compared with the composition found in the prior art such as food packaging films. Can be obtained.
Examples of the component (b) include non-aromatic mineral oils or liquid or low molecular weight synthetic softeners. Generally, a mineral oil softener for rubber is a mixture of an aromatic ring, a naphthene ring and a paraffin chain, and has a saturated hydrocarbon chain carbon number of 50% or more of the total carbon number. Those that occupy 30 to 40% are called naphthenes, and those that occupy 30% or more aromatic carbons are called aromatics. The mineral oil softener for rubber used in the present invention is preferably the paraffinic and naphthenic types described above. Aromatic softeners are not preferred because of their poor dispersibility.
As the non-aromatic hydrocarbon rubber softening agent, a paraffinic mineral oil softening agent is particularly preferable, and paraffinic ones having a small aromatic ring component are particularly suitable.

  Examples of the compound constituting the paraffinic softener include paraffinic compounds having 4 to 155 carbon atoms, preferably paraffinic compounds having 4 to 50 carbon atoms, specifically, butane, pentane, hexane. , Heptane, octane, nonane, decane, undecane, dodecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, eicosan, heneicosan, docosan, tricosan, tetracosan, pentacosan, hexacosan, heptacosan, octacosan, triacotan, henakosan, triacontane, N-paraffins (linear saturated hydrocarbons) such as Kontan, Dotriacontane, Pentatriacontane, Hexacontane, Heptacontane, Isobutane, Isopentane, Neopentane, Isohexane, Pentane, neohexane, 2,3-dimethylbutane, 2-methylhexane, 3-methylhexane, 3-ethylpentane, 2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 3, 3-dimethylpentane, 2,2,3-trimethylbutane, 3-methylheptane, 2,2-dimethylhexane, 2,3-dimethylhexane, 2,4-dimethylhexane, 2,5-dimethylhexane, 3,4 -Dimethylhexane, 2,2,3-trimethylpentane, isooctane, 2,3,4-trimethylpentane, 2,3,3-trimethylpentane, 2,3,4-trimethylpentane, isononane, 2-methylnonane, isodecane, Isoundecane, isododecane, isotridecane, isotetradecane, isopentadecane, isoeo Tadekan, Isonanodekan, isoeicosane, 4-ethyl-5-isoparaffins methyl octane (branched saturated hydrocarbons) and can include derivatives of these saturated hydrocarbons. These paraffins are used in a mixture and are preferably liquid at room temperature.

  Commercially available paraffinic softeners that are liquid at room temperature include NA Solvent (isoparaffinic hydrocarbon oil) manufactured by Nippon Oil & Fats, PW-90 (n-paraffinic process oil) manufactured by Idemitsu Kosan Co., Ltd., and Idemitsu. Examples thereof include IP-solvent 2835 (synthetic isoparaffinic hydrocarbon, 99.8 wt% or more isoparaffin) manufactured by Petrochemical Co., Ltd., neothiozole (n-paraffinic process oil) manufactured by Sanko Chemical Co., Ltd., and the like.

  Moreover, a small amount of unsaturated hydrocarbons and derivatives thereof may coexist in the non-aromatic hydrocarbon softener. Unsaturated hydrocarbons include ethylene, propylene, 1-butene, 2-butene, isobutylene, 1-pentene, 2-pentene, 3-methyl-1-butene, 3-methyl-1-butene, 2-methyl-2 -Ethylene hydrocarbons such as butene, 1-hexene, 2,3-dimethyl-2-butene, 1-heptene, 1-octene, 1-nonene, 1-decene, acetylene, methylacetylene, 1-butyne, 2- Examples thereof include acetylene hydrocarbons such as butyne, 1-pentyne, 1-hexyne, 1-octyne, 1-nonine and 1-decyne.

  The compounding quantity of a component (b) is 75-400 weight part with respect to 100 weight part of component (a), Preferably it is 125-350 weight part. If the blending amount of the component (b) exceeds the above upper limit value, the softened material tends to bleed out, giving the final product tackiness, and the mechanical properties of the molded article and moldability are also reduced. Formability and transparency deteriorate.

(C) Petroleum resin The petroleum resin (c) used in the thermoplastic elastomer composition of the present invention has further flexibility of the resulting composition and transparency without yellowishness, and improves mechanical properties. It is a component that fulfills the function of imparting a well-balanced flexibility and texture.
Flexibility can be imparted to the component (a) by adding a large amount of the component (b), but there are problems such as bleed and manufacturability, and pellet supply is difficult. The component (c) can provide flexibility without increasing the amount of the component (b) added, and further contributes to the improvement of transparency.
The component (c) is a resin obtained by copolymerizing an unsaturated hydrocarbon obtained in various processes of the petroleum refining industry and petrochemical industry, in particular, a naphtha decomposition process, using a C5 fraction as a raw material. Aliphatic petroleum resin, aromatic petroleum resin made from C9 fraction, alicyclic petroleum resin made from dicyclopentadiene, terpene resin, and copolymerization system of these two or more Examples thereof include petroleum resins and hydrogenated petroleum resins obtained by hydrogenating these. The hydrogenated petroleum resin of the above-described resin can be obtained by hydrogenating the above resin by a method known to those skilled in the art. Specifically, Imabe (hydrogenated petroleum resin) manufactured by Idemitsu Petrochemical Co., Ltd., Alcon (hydrogenated petroleum resin) manufactured by Arakawa Chemical Industries, Ltd., and Clearon (hydrogenated terpene resin) manufactured by Yashara Chemical Co., Ltd. Commercial products such as Escorez (aliphatic hydrocarbon resin) manufactured by Tonex Co., Ltd. can be used.

  The compounding quantity of a component (c) is 3-60 weight part with respect to 100 weight part of component (a), Preferably it is 5-50 weight part. If the amount of component (c) exceeds the upper limit, the moldability, flexibility, transparency and oil bleed property deteriorate, and if it is less than the lower limit, the transparency and extrusion moldability deteriorate, and the effect of improving mechanical properties is obtained. Absent.

(D) Terpene oil In the thermoplastic elastomer composition of the present invention, a terpene oil (d) can be used as necessary. The terpene oil (d) has a function of improving the bleed resistance, transparency, flexibility and moldability of the resulting composition.
In particular, the component (d) has a function of suppressing bleeding when the components (b) and (c) are contained in a large amount relative to the component (a).
Component (d) includes essential oils obtained by steam-distilling raw pine fat collected from red pine and black pine stands mainly in North America and mainland China, turpentine oil as a by-product of the pulp production, or orange Specific examples include terpene hydrocarbons and terpene ethers having 10 carbon atoms, which are obtained from essential oils extracted from hides or orange oils derived from these essential oils by isomerization reaction or the like.

  Terpene hydrocarbons having 10 carbon atoms include myrcene (boiling point 167 ° C.), karene (boiling point 167 ° C.), osymene, pinene (boiling point 155 ° C.), limonene (boiling point 176 ° C.), camphene (boiling point 160 ° C.), terpinolene. (Boiling point 187 ° C.), tricyclene (boiling point 153 ° C.), terpinene (boiling point 170-180 ° C.), fenchen (boiling point 150-155 ° C.), ferrandrene (boiling point 170-175 ° C.), silbestrene (boiling point 175 ° C.), Sabinene (boiling point 163 ° C.), P-menten-1 (carbomentene) (boiling point 176 ° C.), P-menten-3 (boiling point 168 ° C.), P-cymene, P-menthane (boiling point 168 ° C.) and the like. Of these, α-pinene, β-pinene, limonene, P-menten-1, P-menten-3, P-cymene, and P-menthane are particularly preferable.

  Examples of the terpene ether having 10 carbon atoms include 1,4-cineole (boiling point 173 ° C.), 1,8-cineole (boiling point 173 ° C.), pinol (boiling point 180 ° C.), and the like. Among these, at least one selected from 1,4-cineole and 1,8-cineole is particularly preferable.

  When blended, the amount of component (d) is 1 to 200 parts by weight, preferably 20 to 150 parts by weight, per 100 parts by weight of component (a). When the amount of component (d) exceeds the upper limit, odor, bleed resistance, moldability and flexibility are deteriorated, and gas generation during the molding process becomes significant. Moreover, if it is less than the said lower limit, there is no improvement effect of a mechanical characteristic.

(E) Other components The thermoplastic elastomer composition of the present invention includes a heat stabilizer, an antioxidant, a light stabilizer, an ultraviolet absorber, a crystal nucleating agent, and an antiblocking agent as long as the object of the present invention is not impaired. , Sealants, mold release agents such as stearic acid and silicone oil, lubricants such as polyethylene wax, colorants, pigments, inorganic fillers (alumina, talc, calcium carbonate, mica, wollastonite, clay), foaming agents (Organic or inorganic), flame retardant (hydrated compound, red phosphorus, ammonium polyphosphate, antimony, silicone) and the like can be blended.
Examples of the antioxidant include 2,6-di-tert-p-butyl-p-cresol, 2,6-di-tert-butylphenol, 2,4-dimethyl-6-tert-butylphenol, 4,4- Examples thereof include phenolic antioxidants such as 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 particularly preferred.
Further, as the foaming agent, EXPANSEL (manufactured by EXPANSEL), which is a thermally expandable microcapsule having a vinylidene chloride / acrylonitrile copolymer as an outer shell and encapsulating isobutane is preferable.

2. Production of Thermoplastic Elastomer Composition The thermoplastic elastomer composition of the present invention is prepared by adding the above components (a) to (c), or components (d) to (e) as necessary, and simultaneously or simultaneously It can be produced by adding and kneading in any order.

  The method of melt kneading is not particularly limited, and generally known methods can be used. For example, a single screw extruder, a twin screw extruder, a roll, a Banbury mixer, or various kneaders can be used. For example, the above operation can be continuously performed by using a suitable L / D twin screw extruder, Banbury mixer, pressure kneader, or the like. Here, the temperature of the melt kneading is preferably 140 to 200 ° C.

  The thermoplastic elastomer composition of the present invention is transparent, free of oil bleed, is a very soft elastic body, and can be supplied with pellets, so that known molding methods such as extrusion molding, injection molding, dipping molding, etc. It can be molded by various molding processes.

Specific applications include, for example, insulators for vibration isolation (with bolts), bolt through bushes, (unevenness) vibration isolation sheets, vibration isolation members such as tapes, seals, chips, and bag cushioning materials (eg, school bag shoulders) Parts, handbags, etc.) PC armrests and wrist rests (also applied to mouse pads), paper feed rollers, audio-related materials (turntables, insulators, spacers, etc.), anti-vibration rubber feet for cases, shoe esthetics Doll's face (skin, etc.), tennis racket, insulation sheet, waterproofing sheet for protection of utility poles, floor slip prevention mats, etc., film sealing products (eg hip protector for the elderly thigh fracture prevention, postoperative body shape auxiliary material) , Rider suits, rifle jackets (eg shoulder pads), sports shoes, beds, high-temperature and high-pressure molding machines (Ceramic molding, etc.), heat conductive gel sheet (eg, for heat dissipation CPU core outer periphery, etc.), game machine vibration control pad, health care related, automobile parts (window packing cushioning material, etc.), automobile door shock absorbers (Sides, etc.), insoles for shoes, shock absorbers for foot care to relieve pain caused by hallux valgus and wound nails, etc., shock absorbers for bumpers and helmets, beds, mattresses, pillows, cushions, cushions, etc. Sports goods such as miscellaneous goods, shock absorbers for bedding, elbows, knees, prevention of back slipping of horses due to saddles, ski shoes, toeshoes, gloves (soccer keeper, golf, ski, rider, etc.) Shock absorbers, shock absorbers for transporting luggage, medical shock absorbers to protect against fractures, injuries and wounds, and to prevent the prosthetic leg and skin from rubbing, milk People who have their breasts cut off, breast pads for swimwear and breast augmentation, artificial food for fishing, etc., cleaning supplies that absorb dust and debris from household items such as desks, chairs, computers, bookshelves, floors, etc. It can be applied to cosmetics such as packs, poultices, fragrances and the like by utilizing the sustained release of oil.
In particular, it can be applied to rotary bearing packings such as pen grips, cushion sheets, disk-type reading / writing storage devices (CD, DVD devices), waterproof packings such as simulated bait, and power box.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further, this invention is not limited to this. In addition, the evaluation method and the used material in an Example are shown below.

1. Evaluation Method for Thermoplastic Elastomer Composition (1) Specific gravity: Based on JIS K 7112, the test piece was measured using a 1 mm thick press sheet.
(2) Hardness: Measured according to JIS K 7215. The test piece was measured by durometer hardness / type A using a 6.3 mm thick press sheet.
(3) Tensile strength, 100% modulus, elongation: In accordance with JIS K 6301, a 1 mm thick press sheet was punched into a No. 3 dumbbell mold and used. The tensile speed was 500 mm / min.
(4) Transparency: A newspaper with a 10 mm thick sheet of 130 x 160 x 5 mm thick sheets obtained by hot pressing at 180 ° C, preheating 4 minutes / pressurization 2 minutes, pressure 50 kg / cm ² The extent to which small characters could be read was visually observed and evaluated according to the following criteria.
○: Vividly readable.
Δ: Although it is unclear, it can be read somehow.
X: Unclear and unreadable.
(5) Oil bleed / tackiness: A sheet of 130 × 160 × 2 mm thickness obtained by hot pressing at 180 ° C., preheating 2 minutes / pressurization 2 minutes, pressure 50 kg / cm ² is sandwiched between kraft papers, 70 mm in diameter The weight of a disk-shaped 500 g was placed, the state of the kraft paper after standing for 168 hours at room temperature (23 ° C.) was visually observed, and evaluated according to the following criteria.
○: Kraft paper is easily peeled off from the sheet and no trace of oil bleed is observed.
(Triangle | delta): Kraft paper slightly adheres to a sheet | seat and the trace of oil bleed is recognized slightly.
X: Kraft paper adheres to the sheet, and traces of oil bleed are observed.
(6) Extrudability: A sheet of 50 mm × 1 mm was extruded, the drawdown property, surface appearance and shape were observed, and the presence or absence of flow marks and sink marks was evaluated according to the following criteria.
○: Good Δ: Slightly bad ×: Bad (7) Injection moldability: A 130 mm × 130 mm × 2 mm sheet was injection molded, the appearance was visually observed, and the presence or absence of flow marks and sink marks was evaluated according to the following criteria. did.
○: Good △: Slightly bad ×: Bad (8) Dipping property: A 1000 cc round bottom flask equipped with a reflux condenser was charged with 200 g of a 60 mm × φ8 magnet stirrer, 200 g of thermoplastic elastomer pellets, and 300 g of industrial xylol. Stirring was carried out for 1 hour in a high-temperature tank with a stirrer maintained at 95 ° C. The mixture was allowed to stand for 12 hours or more until it reached room temperature, stirred for 10 minutes, and dipped once using a Pyrex (registered trademark) test tube (φ18 × 180 mm). The test tube was allowed to stand at room temperature for 30 minutes and then heat-treated in an oven at 120 ° C. for 30 minutes, and the film formation state was visually observed and evaluated according to the following criteria.
○: Good △: Pinhole-like unmelted material ×: Bad

2. Sample (a-1) hydrogenated block copolymer used in Examples and Comparative Examples: Septon 2005 (SEEPS) (trademark; manufactured by Kuraray Co., Ltd.), styrene content 20% by weight, number average molecular weight 210,000, weight Average molecular weight 250,000, molecular weight distribution 1.19, hydrogenation rate 90% or more (a-2) Hydrogenated block copolymer: Septon 2104 (SEPS) (trademark; manufactured by Kuraray Co., Ltd.), styrene content 65% by weight Number average molecular weight 70,000, weight average molecular weight 91,000, molecular weight distribution 1.30, hydrogenation rate 90% or more (a-3) hydrogenated block copolymer: Kraton E-1818E (SEBS) (trademark; Kraton) Manufactured by Polymer Japan Co., Ltd.), styrene content 30% by weight, number average molecular weight 160,000, weight average molecular weight 200,000, molecular weight distribution .25, hydrogenation rate 90% or more (a-4) hydrogenated block copolymer: Kraton 1652 (SEBS) (trademark; manufactured by Kraton Polymer Japan Co., Ltd.), styrene content 29% by weight, number average molecular weight 90,000 , Weight average molecular weight 120,000, molecular weight distribution 1.33, hydrogenation rate 90% or more (a-5) hydrogenated block copolymer: Dynalon DR6210B (CEBC) (trademark; manufactured by JSR Corporation), styrene content 0 Weight%, number average molecular weight 180,000, weight average molecular weight 230,000, molecular weight distribution 1.27, hydrogenation rate 90% or more (b) Non-aromatic rubber softener: NA Solvent NAS-5H (Nippon Yushi Co., Ltd. ) Made) Specific gravity: 0.823, Type: Isoparaffinic hydrocarbon oil, Viscosity (40 ° C.): 11.0 cSt, Flash point: 146 ° C.
(C) Petroleum resin: Imabe P-140 (trademark; manufactured by Idemitsu Petrochemical Co., Ltd.)), softening point: 140 ° C., average molecular weight: 910, density: 1.03
(D) Terpene oil: Woody River # 10 (manufactured by Yasuhara Chemical Co., Ltd.) Specific gravity: 0.80, viscosity (25 ° C.): 1.14 cP, boiling point: 167-170 ° C., flash point: 41.5 ° C.
(E) Hindered phenol / phosphite / lactone complex antioxidant: HP2215 (manufactured by Ciba Specialty Chemicals)

(Examples 1-8, Comparative Examples 1-4)
The mixture was put into a twin screw extruder having an L / D of 47 with the component ratios shown in Tables 1 and 2, and melt-kneaded at a kneading temperature of 180 ° C. and a screw rotation speed of 350 rpm to form pellets. Next, the obtained pellet was injection-molded to prepare a test piece, which was used for each test. The evaluation results are shown in Tables 1 and 2.

As is clear from Tables 1 and 2, the thermoplastic elastomer composition of the present invention had good characteristics (Examples 1 to 8). In Examples 7 and 8, the aromatic vinyl compound content of the component (a) is outside 15 to 45% by weight, and if the aromatic vinyl compound content in the component (a) is small, When the bleed / tack property is slightly inferior and the content of the aromatic vinyl compound in the component (a) is large, the transparency, oil bleed / tack property, and moldability are slightly inferior.
On the other hand, in Comparative Examples 1 and 2, the amount of component (b) is outside the scope of the present invention. When there are few components (b), a softness | flexibility, transparency, and extrusion moldability will deteriorate. When there are many components (b), a moldability deterioration and oil bleed will become remarkable.
In Comparative Examples 3 and 4, the amount of component (c) is out of the scope of the present invention. When there are few components (c), extrusion moldability and transparency will deteriorate. When there are many components (c), a moldability and transparency will deteriorate and oil bleed / tackiness will become remarkable.

  The thermoplastic elastomer composition of the present invention is a thermoplastic elastomer composition having less oil bleed, excellent mechanical strength, transparency, extrusion / injection / dipping molding processability, and excellent transparency and flexibility. Therefore, in particular, it can be applied to a rotary grip packing such as a pen grip, a cushion sheet, a disk-type reading / writing storage device (CD, DVD device), a waterproof packing such as a pseudo bait, a power supply box, and the like.

Claims (3)

(A) 100 parts by weight of hydrogenated or partially hydrogenated block copolymer,
(B) A thermoplastic elastomer composition comprising 75 to 400 parts by weight of a non-aromatic rubber softener and (c) 3 to 60 parts by weight of a petroleum resin.   (D) The thermoplastic elastomer composition according to claim 1, further comprising 1 to 200 parts by weight of a terpene oil.   The thermoplastic elastomer composition according to claim 1 or 2, wherein the content of the aromatic vinyl compound in the (a) hydrogenated or partially hydrogenated block copolymer is 15 to 45% by weight.