JP4548657B2 - Thermoplastic elastomer composition - Google Patents

Description

  The present invention relates to a thermoplastic elastomer composition excellent in transparency and flexibility, and is particularly flexible and tough (high in breaking strength as judged by tensile strength / elongation). Thermoplastic elastomer composition with excellent flexibility and toughness, low oil bleed, excellent mechanical strength, excellent processability, transparency, flexibility, compression set, and vibration absorption About.

  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 reduce 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). Further, as a gel composition, a gel composition obtained by swelling a triblock styrene elastomer in a softening agent (see, for example, Patent Document 4), a triblock styrene elastomer, a diblock styrene elastomer, and a softening. A gel-like composition comprising an agent (see, for example, Patent Documents 5 and 6) 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.
In particular, when the styrene block copolymer as described above (a copolymer alone having a styrene content of about 30% by weight) and a large amount of an oil-containing composition are stretched, they tend to break apart (as judged by tensile strength / elongation). The breaking strength is small). In addition, the heat resistance is low, and the oil bleed is crisp and sticky.

  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 As a thermoplastic gel composition having wear resistance, a thermoplastic resin containing a softener for non-aromatic hydrocarbon rubber, a hydrogenated styrene thermoplastic elastomer, and an amorphous polyolefin. Sex 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 obtained by blending a partially hydrogenated block copolymer in which a conjugated diene moiety is partially hydrogenated with a tackifier such as a terpene resin (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). ), A stretch film for food packaging comprising a hydrogenated styrene block copolymer, petroleum resin, and polypropylene resin (see, for example, Patent Documents 14 to 16). There has been disclosed. However, all of the techniques described in these patent documents merely use tackifying properties such as petroleum resin, have few oil bleeds, have excellent mechanical strength, transparency, flexibility, and formability. 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 few oil bleeds, excellent mechanical strength (particularly difficult to tear when stretched), transparency, flexibility, compression set, and further, extrusion molding, injection Excellent transparency and flexibility with molding processability such as molding and dipping molding, and toughness (high breaking strength as judged by tensile strength / elongation), especially compared with urethane cured gel and silicone cured gel However, an object of the present invention is to provide a thermoplastic elastomer composition which is excellent in flexibility and toughness.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor softened a non-aromatic rubber into a hydrogenated and / or partially hydrogenated block copolymer mixture having two kinds of specific aromatic vinyl compound contents. It is an elastic body that can be supplied with pellets, can be processed in various forms, is transparent, and does not have oil bleed. The inventors have found that a thermoplastic elastomer composition can be obtained, and have completed the present invention.

That is, according to the first invention of the present invention, (a) 100 parts by weight of a hydrogenated and / or partially hydrogenated block copolymer mixture having an aromatic vinyl compound content of 15 to 50% by weight (provided that (A) is (a-1) (a-2) an aromatic vinyl compound with respect to 100 parts by weight of a hydrogenated and / or partially hydrogenated block copolymer having an aromatic vinyl compound content of 40 to 70% by weight. Containing 20 to 700 parts by weight of a hydrogenated and / or partially hydrogenated block copolymer with a content of less than 40% by weight.), And (b) containing 160 to 400 parts by weight of a non-aromatic rubber softener. A thermoplastic elastomer composition is provided.

  According to a second aspect of the present invention, there is provided a thermoplastic elastomer composition characterized in that, in the first aspect, (c) 1 to 40 parts by weight of a petroleum resin is further contained.

  According to the third invention of the present invention, there is provided a thermoplastic elastomer composition characterized in that in the first or second invention, (d) 1-60 parts by weight of a terpene oil is further contained. .

  Moreover, according to the 4th invention of this invention, the molded object which consists of a thermoplastic elastomer composition of any one of the 1st-3rd invention is provided.

  The thermoplastic elastomer composition of the present invention has less oil bleed, and has excellent mechanical strength, transparency and compression set represented by breaking strength (determined by tensile strength / elongation), extrusion molding, It is a thermoplastic elastomer composition that is excellent in molding processability such as injection molding, and is excellent in transparency and flexibility.

The components, production methods, and uses constituting the present invention will be described in detail below.
1. Component (a) Hydrogenated and / or Partially Hydrogenated Block Copolymer Mixture of Thermoplastic Elastomer Composition The hydrogenated and / or partially hydrogenated block copolymer mixture used in the thermoplastic elastomer composition of the present invention is aromatic. Hydrogenated and / or partially hydrogenated block copolymer mixture having an aromatic vinyl compound content of 15 to 50% by weight, comprising (a-1) hydrogenated aromatic vinyl compound content of 40 to 70% by weight And / or a mixture of a partially hydrogenated block copolymer and (a-2) a hydrogenated and / or partially hydrogenated block copolymer having an aromatic vinyl compound content of less than 40% by weight.
By using such a component (a), it is excellent in transparency and flexibility and is tough (high breaking strength as judged by tensile strength / elongation), especially compared with urethane cured gel and silicone cured gel Even so, a thermoplastic elastomer composition having excellent flexibility and toughness can be obtained.
The component (a) not only exhibits rubber elasticity and mechanical properties, but also improves the oil absorption efficiency of the softener for (b) non-aromatic rubber at the time of blending, and has dispersibility and meltability at the time of melt kneading. Improve. As a result, the moldability is improved, and the mechanical properties and transparency of the obtained product are improved.

The hydrogenated and / or partially hydrogenated block copolymer of (a-1) or (a-2) is mainly composed of at least one polymer block A mainly composed of an aromatic vinyl compound and a conjugated diene compound. And a hydrogenated block copolymer obtained by hydrogenating a block copolymer comprising at least one polymer block B.
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, in the polybutadiene block, the 1,2-microstructure is preferably 20 to 50% by weight, particularly preferably 25 to 45%. % By weight. Moreover, the thing which selectively hydrogenated the 1, 2- bond 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, the weight average molecular weight of the whole hydrogenated and / or partially hydrogenated block copolymer component is 100,000 to 350,000, preferably 130,000 to 250,000. If the weight average molecular weight exceeds 350,000, the moldability deteriorates. On the other hand, when the weight average molecular weight is less than 100,000, compression set is deteriorated.

  Specific examples of the hydrogenated and / or partially hydrogenated block polymer component include styrene-ethylene-butene copolymer (SEB), styrene-ethylene-propylene copolymer (SEP), and styrene-ethylene-butene-styrene copolymer. Polymer (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 (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.

  The aromatic vinyl compound content in the component (a) used in the present invention is 15 to 50% by weight, preferably 25 to 47% by weight. When the content of the aromatic vinyl compound in the component (a) exceeds 50% by weight, flexibility, transparency, especially mechanical properties such as tensile strength / elongation, bleed resistance, and moldability deteriorate, and less than 15% by weight. However, mechanical properties such as tensile strength and elongation, formability, and bleed resistance deteriorate.

  The hydrogenated and / or partially hydrogenated block copolymer (a-1) used in the component (a) has an aromatic vinyl compound content of 40 to 70% by weight, preferably 50 to 65% by weight. %. If the content of the aromatic vinyl compound exceeds the above upper limit, the softening agent tends to bleed out, and the flexibility, mechanical properties, and moldability of the final product also deteriorate, and if it is less than the lower limit, the moldability and mechanical properties deteriorate. To do.

The hydrogenated and / or partially hydrogenated block copolymer (a-2) used in the component (a) has an aromatic vinyl compound content of less than 40% by weight, preferably 20 to 40%. % By weight.
Hydrogenated and / or partially hydrogenated block copolymers having an aromatic vinyl compound content of less than 40% by weight not only exhibit rubber elasticity and mechanical properties, but also (b) soften for non-aromatic rubber during compounding It has the effect of improving the oil absorption efficiency of the agent and improving the flexibility, mechanical properties, and transparency of the resulting product.

In particular, when stretched with a conventional styrene block copolymer (copolymer alone having a styrene content of about 30% by weight) and a large amount of oil-containing composition, the stretched material was easily broken (judged by tensile strength / elongation). Small breaking strength). In addition, since the heat resistance is low and the oil bleed is harsh and sticky, it is inevitable that in the present invention, the component (a) includes the following specific proportions of the components (a-1) and (a-2): ) The problem is solved by using a mixture of components.
Specifically, the composition ratio of the two types of block copolymers in component (a) is as follows: (a-1) Hydrogenated and / or partially hydrogenated block copolymer having an aromatic vinyl compound content of 40 to 70% by weight. (A-2) Hydrogenated and / or partially hydrogenated block copolymer having an aromatic vinyl compound content of less than 40% by weight with respect to 100 parts by weight of the polymer is 20 to 700 parts by weight, preferably 20 -500 parts by weight. (A-2) When the hydrogenated and / or partially hydrogenated block copolymer having an aromatic vinyl compound content of less than 40% by weight exceeds 700 parts by weight, the oil bleed, particularly the tensile strength / elongation machine Properties and moldability deteriorate, and if it is less than 20 parts by weight, flexibility and transparency, particularly mechanical properties such as tensile strength and elongation, and moldability deteriorate.

  In addition, a hydrogenated conjugated diene block copolymer may be used as the (a-2) hydrogenated and / or partially hydrogenated block copolymer having an aromatic vinyl compound content of less than 40% by weight. Examples of the hydrogenated conjugated diene block copolymer include a block copolymer (CEBC) having a crystalline ethylene block and an amorphous ethylene-butene block obtained by hydrogenating a block copolymer of butadiene. Can also be used. The weight average molecular weight of the hydrogenated product of the conjugated diene block copolymer is preferably 100,000 to 350,000, and more preferably 130,000 to 250,000. When the weight average molecular weight exceeds 350,000, the moldability deteriorates, and when it falls below 100,000, the compression set deteriorates.

(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 component (b) of 160 to 400 parts by weight to component (a) as compared with compositions found in 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, and 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 Contan, Dotriacontane, Pentatriacontane, Hexacontane, Heptacontane, etc., 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 their derivatives 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 160-400 weight part with respect to 100 weight part of component (a), Preferably it is 200-350 weight part. If the blending amount of component (b) exceeds the above upper limit value, the softening agent tends to bleed out, giving the final product tackiness, and reducing the mechanical properties such as tensile strength and elongation of the molded product, and moldability, If it is less than the said minimum, a softness | flexibility, a moldability, and transparency will deteriorate.

(C) Petroleum resin In the thermoplastic elastomer composition of the present invention, a petroleum resin (c) can be used as necessary. Component (c) is a component that functions to impart further flexibility and yellowness-free transparency of the resulting composition, to improve mechanical properties, and to provide more 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.
Component (c) is a resin obtained by copolymerizing an unsaturated hydrocarbon obtained in various processes in the petroleum refining industry and petrochemical industry, particularly in the naphtha decomposition process, and 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.

  When blended, the amount of component (c) is preferably 1 to 40 parts by weight, more preferably 5 to 30 parts by weight, per 100 parts by weight of component (a). 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).
Ingredient (d) includes essential oils obtained by steam distillation of 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 pulp production of the tree, 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.

  Terpenic 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 600 parts by weight, preferably 5 to 20 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 (b), or components (c) 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, excellent in compression set and vibration absorption, has no oil bleed, is a very soft elastic body, and can be supplied with pellets. Molding by various molding processes by known molding methods such as molding and dipping molding is possible.

3. Applications of thermoplastic elastomer compositions Specific applications include, for example, bag cushioning materials (eg, shoulder bag shoulders, handbags, etc.), personal computer armrests and wrist rests (also applied to mouse pads), paper feed rollers, etc. Materials, face of doll for esthetics (skin, etc.), tennis racket, insulation sheet, waterproofing sheet for protection of telephone pole, mat for preventing floor slip, etc., film sealing products (for example, hip protector for preventing thigh fracture of the elderly, postoperative body Shape auxiliary materials), suits for riders, rifle jackets (eg shoulder pads), sports shoes, beds, cushions for high-temperature and high-pressure molding machines (ceramic molding, etc.), heat conductive gel sheets (eg, for heat-dissipating CPU core outer circumferences), healthcare Automotive parts (window packing cushioning materials, etc.), automotive 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, miscellaneous goods such as beds, mattresses, pillows, cushions, cushions, Shock absorbers for bedding, elbow pads, knee pads, prevention of saddleback of horses by heels, sports-related shock absorption such as ski shoes, toe shoes, gloves (for soccer keeper, golf, ski, rider, etc.) Drugs, shock absorbers for transporting luggage, fractures, medical shock absorbers to protect against injuries and injuries, and to prevent rubbing of the prosthetic leg and skin, breast pads, breast pads for swimwear and breast augmentation , Fake foods for fishing, etc., desks, chairs, personal computers, bookshelves, cleaning products that absorb dust and debris from daily life, and cosmetics such as packs using the sustained release of oil Poultices, it is applicable to fragrances, and the like.
Especially, application to waterproof packings, such as a pen grip, a cushion sheet, a pseudo bait, and a power supply box, is possible.

  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) Compression set: conformed to JIS K 6262. The test piece used was a 6.3 mm thick press sheet, and the distortion after 70 ° C. × 22 hours was measured.
(5) Volume change rate: In accordance with JIS K 6258, the test piece was a 1 mm thick press sheet punched into No. 3 with a dumbbell and used. Using IRM # 901 oil, volume change at 70 ° C. × 24 hours was measured.
(6) Transparency: A newspaper with a 10 mm thick sheet of 130 × 160 × 5 mm thick sheets obtained by hot pressing at 180 ° C., preheating 4 minutes, pressure 2 minutes, and pressure 50 kg / cm ² It was made to contact and the degree which can read a small type | mold, and the poor melting was visually observed, and the following reference | standard evaluated.
(Double-circle): In addition to not being able to read clearly and not having a poor melting defect, yellow color is very little further.
○: Vividly readable and no defective melting.
(Triangle | delta): Although it is unclear, it can be read somehow, and some melted spots are seen.
X: There are a lot of melting spots, and it is unclear and cannot be read.
(7) Oil bleed / tackiness: A sheet of 130 × 160 × 2 mm thickness obtained by hot pressing at 180 ° C., preheating 2 minutes, pressurizing 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.
(8) Extrudability: Extrude a sheet with a width of 50 mm x thickness of 1 mm, and in particular, observe poor melting, drawdown, surface appearance and shape, and evaluate the presence or absence of flow marks and sink marks according to the following criteria: did.
○: Good Δ: Slightly bad ×: Bad (9) Injection moldability: A 130 mm × 130 mm × 2 mm sheet is injection molded, the appearance is visually observed, and the presence or absence of flow marks and sink marks is evaluated according to the following criteria. did.
A: Especially good (good regardless of injection molding conditions (low temperature / high pressure molding), good without flow marks and glossy spots)
○: Good (there is no flow mark, but some gloss spots occur depending on the injection molding conditions (lower temperature and higher pressure molding))
△: Slightly bad (flow marks and glossy spots are generated depending on injection molding conditions (lower temperature and higher pressure molding))
×: Poor (flow marks and gloss spots occur regardless of injection molding conditions (low temperature and high pressure molding))
(10) Dipping property: A 1000 cc round bottom flask equipped with a reflux condenser was charged with a 60 mm × φ8 magnetic stirrer, 200 g of thermoplastic elastomer pellets and 300 g of industrial xylol, and a high-temperature tank with a stirrer maintained at about 95 ° C. For 1 hour. 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.
A: Particularly good (good film-forming property even if not left at room temperature for 30 minutes)
○: Good (good film-forming property if left at room temperature for 30 minutes)
Δ: Pinhole-shaped unmelted material, spots, sagging ×: Poor (even if left at room temperature for 60 minutes or more, pinhole-shaped unmelted material, spots, sagging)

2. Sample (a-2-1) 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-1-1) hydrogenated block copolymer: Septon 2104 (SEPS) (trademark; manufactured by Kuraray Co., Ltd.), containing styrene 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-2-2) hydrogenated block copolymer: Kraton E-1818E ( SEBS) (trademark; manufactured by Kraton Polymer Japan Ltd.), styrene content 30% by weight, number average molecular weight 160,000, weight average molecular weight 200,000 Molecular weight distribution 1.25, hydrogenation rate 90% or more (a-2-3) hydrogenated block copolymer: Dynalon DR6210B (CEBC) (trademark; manufactured by JSR Corporation), styrene content 0% by 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: Diana Process Oil PW-90 (manufactured by Idemitsu Kosan Co., Ltd.) Specific gravity: 0.872, type: paraffinic hydrocarbon oil, viscosity (40 ° C.): 95.5 cSt, flash point: 270 ° C., average molecular weight: 539
(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 composite antioxidant: HP2215 (trademark; manufactured by Ciba Specialty Chemicals)

(Examples 1-5, Comparative Examples 1-5)
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 5).
On the other hand, in Comparative Examples 1 and 2, the aromatic vinyl compound content of the component (a) is outside 15 to 50% by weight, and if the aromatic vinyl compound content in the component (a) is small, Mechanical properties such as bleed / tackiness, tensile strength / elongation are inferior, and if the aromatic vinyl compound content in component (a) is large, flexibility, mechanical properties such as tensile strength / elongation, transparency, oil Bleed / tackiness and moldability are inferior.
In Comparative Examples 3 and 4, the amount of component (b) is out of the scope of the present invention. When there are few components (b), a moldability, transparency, and a softness | flexibility will deteriorate. When there are many components (b), mechanical characteristics, such as a moldability and tensile strength and elongation, will deteriorate, and oil bleed / tackiness will become remarkable.
In Comparative Example 5, two types of hydrogenated block copolymers having different aromatic vinyl compound contents were not used. When only one kind of component (a) is used, in addition to inferior tensile strength / elongation, which is a measure of breaking strength, flexibility and moldability are inferior.

  The thermoplastic elastomer composition of the present invention has a small amount of oil bleed, has excellent mechanical strength, transparency, extrusion / injection molding processability, and is excellent in transparency, flexibility, and compression set. Therefore, in particular, it can be applied to waterproof packings such as pen grips, cushion sheets, artificial baits, and power supply boxes.

Claims (4)

(A) 100 parts by weight of a hydrogenated and / or partially hydrogenated block copolymer mixture having an aromatic vinyl compound content of 15 to 50% by weight (provided that (a) is (a-1) aromatic vinyl (A-2) Hydrogenation and / or aromatic vinyl compound content of less than 40% by weight with respect to 100 parts by weight of hydrogenated and / or partially hydrogenated block copolymer having a compound content of 40 to 70% by weight The hydrogenated and / or partially hydrogenated block copolymer referred to in (a), (a-1) and (a-2) is contained in 20 to 700 parts by weight of a partially hydrogenated block copolymer. Both are obtained by hydrogenating a block copolymer consisting of 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 hydrogenated block copolymer In the case where the aromatic vinyl compound content is 0% by weight in (a-2), a block having a crystalline ethylene block and an amorphous ethylene-butene block obtained by hydrogenating a block copolymer of butadiene A thermoplastic elastomer composition comprising 160 to 400 parts by weight of a softener for non-aromatic rubber, and (b) a copolymer (CEBC) .   (C) The thermoplastic elastomer composition according to claim 1, further comprising 1 to 40 parts by weight of a petroleum resin.   (D) The thermoplastic elastomer composition according to claim 1, further comprising 1 to 60 parts by weight of a terpene oil. The thermoplastic elastomer composition according to any one of claims 1 to 3, wherein the blending amount of the softening agent for (b) non-aromatic rubber is 200 to 400 parts by weight.