JP2004137479A - Thermoplastic elastomer composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic elastomer composition having excellent flexibility and rubber elasticity at a high temperature, capable of having a wide range of hardness, and capable of producing a molded product having excellent creep resistant performance at a high temperature, mechanical strength, oil resistance, solvent resistance, heat resistance, weathering resistance, surface characteristics, etc. <P>SOLUTION: This thermoplastic elastomer composition is obtained by dynamically crosslinking a mixture comprising components (i), (ii), and (iii). The component (i) contains (a) a hydrogenated block copolymer which is obtained by hydrogenating a block copolymer containing at least one polymer block A consisting mainly of a vinyl aromatic compound and at least one polymer block B consisting mainly of a conjugated diene compound and has an iodine value of 10-40g/100 g and a weight-average molecular weight of ≥200,000, (b) a softening agent for a non-aromatic rubber, (c) an olefinic resin of peroxide decomposed type, (d) an organic peroxide, and (e) a crosslinking auxiliary. The component (ii) contains the softening agent for the non-aromatic rubber (b) in an amount of 50-250 pts.mass based on 100 pts.mass of the hydrogenated block copolymer (a). The component (iii) contains the olefinic resin of peroxide decomposed type (c) in an amount of 20-300 pts.mass based on 100 pts.mass of the copolymer (a). <P>COPYRIGHT: (C)2004,JPO

Description

INDUSTRIAL APPLICABILITY The present invention is excellent in flexibility and rubber elasticity, particularly rubber elasticity at high temperature (for example, small compression set at a temperature of 100 to 120 ° C.), and can have a wide hardness range, The present invention relates to a thermoplastic elastomer composition having excellent creep resistance, mechanical strength, oil resistance, solvent resistance, heat resistance, and weather resistance. The thermoplastic elastomer composition obtained by the method of the present invention can be effectively used as a material for various molded articles by utilizing these excellent properties.

Thermoplastic elastomers do not require a vulcanization step and can be molded and processed in the same way as thermoplastic resins.In recent years, thermoplastic elastomers have been used in a wide range of fields such as automotive parts, home appliances parts, wire coatings, medical parts, footwear, and miscellaneous goods. It is used. Among such thermoplastic elastomers, polystyrene-polybutadiene-polystyrene block copolymer (SBS), polystyrene-polyisoprene-polystyrene block copolymer (SIS), and their hydrogenated products (hydrogenated products) are represented. Styrene-based thermoplastic elastomers are widely used because they are inexpensive and have excellent hydrolysis resistance.

A vinyl aromatic compound polymer represented by a hydrogenated product (hydrogenated product) of a polystyrene-polybutadiene-polystyrene block copolymer or a hydrogenated product (hydrogenated product) of a polystyrene-polyisoprene-polystyrene block copolymer A hydrogenated product (hydrogenated product) of a block copolymer containing a block and a conjugated diene compound polymer block is heat-resistant in a block copolymer containing a vinyl aromatic compound polymer block and a conjugated diene compound polymer block. However, the rubber elasticity at high temperature is inferior and the compression set at high temperature (for example, at a temperature of 100 to 120 ° C.) is large.

In order to improve the above point, a hydrogenated product (hydrogenated product) of a block copolymer composed of such a vinyl aromatic compound polymer block-conjugated diene compound polymer block is obtained by a) peroxide-decomposable olefin resin. And b) a method of partially cross-linking with an organic peroxide in combination with a peroxide cross-linked olefin copolymer rubber or a peroxide cross-linked olefin resin (Patent Documents 1 and 2). reference).

More specifically, Patent Document 1 discloses (a-1) 100 parts by mass of a hydrogenated product of a block copolymer containing two or more vinyl aromatic compound polymer blocks and one or more conjugated diene compound polymer blocks. (A-2) 20 to 150 parts by mass of a peroxide crosslinked olefin copolymer rubber, (A-3) 0 to 50 parts by mass of a peroxide non-crosslinked hydrocarbon rubber material, (A-4) Non-peroxide 80 to 300 parts by mass of a softening agent for aromatic rubber, (A-5) 30 to 400 parts by mass of a peroxide-decomposable olefin resin, and (A-6) 0 to 900 parts by mass of an inorganic filler, First, of all the components except for (A-1), at least the entire amount of (A-2) is heat-treated in the presence of an organic peroxide to cause dynamic crosslinking, and then the dynamically crosslinked product is mixed with the remaining components. Elastomeric composition The method of manufacturing is disclosed. Patent Document 1 describes that the mechanical strength of the elastomeric composition is significantly reduced when the multi-stage partial crosslinking-blending step is not employed.

Patent Document 2 discloses a block copolymer containing two or more (b-1) vinyl aromatic compound polymer blocks and one or more conjugated diene compound polymer blocks and / or 100 parts by mass of a hydrogenated product thereof. (B-2) 40 to 300 parts by weight of a softener for non-aromatic rubber, (b-3) 1.0 to 100 parts by weight of a peroxide-crosslinked olefin resin and / or a copolymer rubber containing the same. (B-4) In a method for producing a thermoplastic elastomer composition containing 10 to 150 parts by mass of a peroxide-decomposable olefin-based resin and / or a copolymer containing the same, the components (B-1) and (B-2) , At least a part of the component (b-3) and a part of the component (b-4) are heat-treated in the presence of an organic peroxide to crosslink, and then the crosslinked product and the remainder of the component (b-4) , Other manufacturing method of the thermoplastic elastomer resin composition is disclosed to incorporate the remainder of the component (b -3) and the component (B -4). This publication discloses that a composition dynamically crosslinked in the presence of an organic peroxide and a component (b-4) to be blended later are compatible and micro-dispersed in the composition to obtain a thermoplastic resin. It is described that the processing characteristics, fluidity, mechanical strength, and the like of the elastomer resin composition are improved.

However, none of the methods described in the two patent documents described above can dynamically cross-link each component at a final blending ratio at once, and after partially cross-linking some of the components, Since it is necessary to mix the remaining components, the production process of the thermoplastic elastomer resin composition is very complicated, and the rubber elasticity especially under high temperature (for example, compression set at a temperature of 100 to 120 ° C.) ) Is still insufficient.

Further, a hydrogenated product of a block copolymer comprising a vinyl aromatic compound polymer block and a conjugated diene compound polymer block having a specific hydrogenation rate is obtained by a) a polyolefin resin and b) a reactive alkylphenol / formaldehyde resin. In addition, a thermoplastic elastomer composition dynamically vulcanized in the presence of a hydrotalcite compound has been proposed (see Patent Document 3).

More specifically, Patent Literature 3 discloses (C-1) comprising a polymer block mainly composed of at least one vinyl aromatic compound and a polymer block mainly composed of at least one conjugated diene compound. Hydrogenation of the block copolymer, and 100 parts by mass of a hydrogenated block copolymer having a hydrogenation rate of an aliphatic double bond based on the conjugated diene compound of more than 60% and less than 85%, (C-2) 20 to 200 parts by mass of a softener for a non-aromatic rubber, (C-3) 15 to 150 parts by mass of a polyolefin resin, (C-4) 0.3 to 30 parts by mass of a reactive alkylphenol / formaldehyde resin, (C-5 A) A dynamically vulcanized thermoplastic elastomer composition obtained by blending 0 to 50 parts by mass of each of hydrotalcite compounds and heating and kneading the composition. Workability as chromatography, while having the possibility of recycling scrap, it is described that has a breakdown voltage superior compression set properties and mechanical strength, and good weatherability and oil resistance at high temperatures.

However, in the case of the thermoplastic elastomer composition of Patent Document 3, when producing a composition having excellent compression set characteristics at high temperatures, a metal such as stannous chloride is used as a vulcanization accelerator during dynamic vulcanization. It is necessary to incorporate an organic halide such as halide, chlorinated polyethylene or a heavy metal compound such as zinc oxide, which is not preferable from the viewpoint of safety. In addition, the thermoplastic elastomer composition of Patent Document 3 has a high hardness of 50 or more in Type A based on JIS # K-6253, and cannot produce a composition in a wide hardness range.

JP-A-59-6236 JP-A-8-225713 JP-A-5-302012

Thus, an object of the present invention is to provide a mixture containing a block copolymer composed of a vinyl aromatic compound polymer block and a conjugated diene compound polymer block, a softener for a non-aromatic rubber, and a peroxide decomposable olefin resin. In a thermoplastic elastomer composition dynamically crosslinked in the presence of an organic peroxide, a multi-stage partial crosslinking-blending step as in the prior art described in Patent Document 1 and Patent Document 2 is not necessarily required. Another object of the present invention is to provide a dynamically crosslinked thermoplastic elastomer composition having excellent physical properties, which can be obtained in any heating and kneading step including one step. In particular, it is excellent in flexibility and rubber elasticity, particularly rubber elasticity at a high temperature in a single simple heating and kneading step (for example, the compression set at a temperature of 100 to 120 ° C. is small). It can have a wide range of hardness that can not be achieved with the composition of the above, and it is also possible to produce molded products etc. with excellent high temperature creep performance, mechanical strength, oil resistance, solvent resistance, heat resistance, weather resistance, surface properties etc. To provide a dynamically crosslinked thermoplastic elastomer composition.

(4) The present inventors have studied to achieve the above object. As a result, a hydrogenated product of a block copolymer containing a vinyl aromatic compound polymer block and a conjugated diene compound polymer block, a softener for a non-aromatic rubber and a peroxide decomposable olefin resin, and optionally a vinyl In producing a thermoplastic elastomer composition by dynamically cross-linking a mixture containing a block copolymer containing an aromatic compound polymer block and a conjugated diene compound polymer block in the presence of an organic peroxide, a vinyl aromatic compound As a hydrogenated product of a block copolymer containing a polymer block and a conjugated diene compound polymer block, one having a specific range of iodine value (hydrogenation rate) and a specific range of molecular weight is used. Hydrogenated copolymer, softener for non-aromatic rubber and perovskite When the blending amount of the side-decomposable olefin-based resin and, if necessary, the block copolymer containing the vinyl aromatic compound polymer block and the conjugated diene compound polymer block is within a specific range, the multi-stage dynamics as in the prior art can be obtained. It has been found that a dynamic cross-linking-blending step becomes unnecessary, and a dynamically cross-linked thermoplastic elastomer composition having good physical properties can be obtained in a single-stage heating and kneading step.

In particular, the dynamically crosslinked thermoplastic elastomer composition obtained by such a one-stage heating and kneading step and the molded product obtained therefrom have excellent flexibility and rubber elasticity, particularly under high temperature (for example, at a temperature of 100 to 120 ° C). Excellent rubber elasticity, low compression set even when compressed at high temperatures for a long time, and can have a wide range of hardness, creep resistance at high temperatures, mechanical strength, oil resistance, solvent resistance It has been found that it has excellent properties such as heat resistance, heat resistance (for example, the degree of coloring at 200 ° C.), weather resistance, and the like, and has a good appearance without surface roughness or bleed-out of a softener to the surface.
Further, the inventors of the present invention preferably use, as the hydrogenated product of the block copolymer, one in which the conjugated diene polymer block is a polymer block composed of butadiene and isoprene, and an organic peroxide and a crosslinking aid. It has been found that the compounding amount of is preferably in a specific range, and that a non-aromatic rubber softener having a specific kinematic viscosity is preferably used, and the present invention has been completed based on those findings.

That is, the present invention
(1) (i) A block copolymer containing at least one polymer block A mainly composed of a vinyl aromatic compound and at least one polymer block B mainly composed of a conjugated diene compound is hydrogenated. A hydrogenated block copolymer having a weight average molecular weight of 200,000 or more (a) having an iodine value of the block copolymer in the range of 10 to 40 g / 100 g, a softener for non-aromatic rubber (b), and a peroxide decomposable type It contains an olefin resin (c), an organic peroxide (d) and a crosslinking aid (e); and
(Ii) the amount of the softening agent for non-aromatic rubber (b) is 50 to 250 parts by mass with respect to 100 parts by mass of the hydrogenated block copolymer (a);
(Iii) the amount of the peroxide-decomposable olefin-based resin (c) is 20 to 300 parts by mass with respect to 100 parts by mass of the hydrogenated block copolymer (a);
A thermoplastic elastomer composition obtained by dynamically crosslinking a mixture comprising:

The present invention
(2) The thermoplastic elastomer composition according to (1), wherein the polymer block B mainly composed of a conjugated diene compound in the hydrogenated block copolymer (a) is a polymer block composed of butadiene and isoprene;
(3) The total amount of the organic peroxide (d) is 100 in total of the hydrogenated block copolymer (a), the softener for non-aromatic rubber (b) and the peroxide decomposable olefin resin (c). (1) The amount of the crosslinking aid (e) is from 0.5 to 3 times by mass the amount of the organic peroxide (d) with respect to the amount of the organic peroxide (d). ) Or (2) the thermoplastic elastomer composition; and (4) the kinematic viscosity (Bv) at 40 ° C. (mm ² / s) of the non-aromatic rubber softener (b) is represented by the following formula [1]: The thermoplastic elastomer composition according to any one of the above (1) to (3);
Bv (mm ² / s) ≧ 3 × 10 ⁷ / Mwa [1]
[In the above formula, Bv indicates the kinematic viscosity at 40 ° C. of the softener (b) for non-aromatic rubber, and Mwa indicates the weight average molecular weight of the hydrogenated block copolymer (a). ];
Is included as a preferred embodiment.

Also, the present invention
(5) Hydrogenated block copolymer (a), softener for non-aromatic rubber (b), peroxide-decomposable olefin resin (c), organic peroxide (d) and crosslinking aid (e) The thermoplastic elastomer composition according to any one of the above (1) to (4), wherein the mixture containing the whole amount is melt-kneaded in a single step under heating and dynamically crosslinked.

Further, the present invention provides
(6) (i) A block copolymer containing at least one polymer block A mainly composed of a vinyl aromatic compound and at least one polymer block B mainly composed of a conjugated diene compound is hydrogenated. A hydrogenated block copolymer (a) having a weight average molecular weight of 200,000 or more, in which the block copolymer has an iodine value of 10 to 40 g / 100 g, and at least one polymer block A1 mainly composed of a vinyl aromatic compound. And a block copolymer (a1) containing at least one polymer block B1 mainly composed of a conjugated diene compound, a softener for non-aromatic rubber (b), a peroxide-decomposable olefin resin (c), and an organic compound. A peroxide (d) and a crosslinking aid (e); and
(Ii) the mass ratio of the hydrogenated block copolymer (a) to the block copolymer (a1) is 99: 1 to 86:14;
(Iii) The compounding amount of the softening agent for non-aromatic rubber (b) is 50 to 250 parts by mass with respect to 100 parts by mass in total of the hydrogenated block copolymer (a) and the block copolymer (a1). And;
(Iv) The peroxide-decomposable olefin resin (c) is used in an amount of 20 to 300 parts by mass based on 100 parts by mass of the total of the hydrogenated block copolymer (a) and the block copolymer (a1). is there;
A thermoplastic elastomer composition obtained by dynamically crosslinking a mixture comprising:

The present invention
(7) In the block copolymer (a1), the total of 1,2-linkage units and 3,4-linkage units is 30 to 95 among the binding units constituting the polymer block B1 mainly composed of a conjugated diene compound. Mol% of the thermoplastic elastomer composition of the above (6);
(8) The compounding amount of the organic peroxide (d) is such that the hydrogenated block copolymer (a), the block copolymer (a1), the softener for non-aromatic rubber (b) and the peroxide decomposable olefin 0.3 to 3 parts by mass based on a total of 100 parts by mass of the system resin (c), and the compounding amount of the crosslinking assistant (e) is 0.5 to 3 with respect to the compounding amount of the organic peroxide (d). (9) Kinematic viscosity (Bv) at 40 ° C. of the thermoplastic elastomer composition of (6) or (7), which is 3 times by mass; and (9) the softener for non-aromatic rubber (b) (mm ² / s). Is the thermoplastic elastomer composition according to any one of the above (6) to (8), which satisfies the following formula [1];
Bv (mm ² / s) ≧ 3 × 10 ⁷ / Mwa [1]
[In the above formula, Bv indicates the kinematic viscosity at 40 ° C. of the softener (b) for non-aromatic rubber, and Mwa indicates the weight average molecular weight of the hydrogenated block copolymer (a). ];
Is included as a preferred embodiment.

And the present invention
(10) hydrogenated block copolymer (a), block copolymer (a1), softener for non-aromatic rubber (b), peroxide-decomposable olefin resin (c), organic peroxide (d) A thermoplastic elastomer composition according to any one of the above (6) to (9), wherein the mixture containing the entire amount of the crosslinking assistant (e) is melt-kneaded in a single step under heating to dynamically crosslink. Thing;

ADVANTAGE OF THE INVENTION According to this invention, it is excellent in flexibility and rubber elasticity, especially rubber elasticity under high temperature (for example, 100-120 degreeC), has a small compression set, can have a wide hardness range, and can withstand high temperature. A dynamically crosslinked thermoplastic elastomer composition capable of producing a molded article having excellent creep performance, mechanical strength, oil resistance, solvent resistance, heat resistance, weather resistance, surface properties and the like can be obtained.

Hereinafter, the present invention will be described in detail.
The hydrogenated block copolymer (a) used in the present invention contains at least one polymer block A mainly composed of a vinyl aromatic compound and at least one polymer block B mainly composed of a conjugated diene compound. Is a hydrogenated block copolymer having a weight average molecular weight of 200,000 or more in which the block copolymer has an iodine value of 10 to 40 g / 100 g.

In the hydrogenated block copolymer (a), examples of the vinyl aromatic compound constituting the polymer block A include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, and p-methylstyrene. Examples thereof include t-butylstyrene, 2,4-dimethylstyrene, 2,4,6-trimethylstyrene, monofluorostyrene, monochlorostyrene, dichlorostyrene, vinylnaphthalene, and vinylanthracene. It can be formed from one or more vinyl aromatic compounds. Among them, the polymer block A is preferably formed from styrene or p-methylstyrene.

The polymer block A may optionally contain an unsaturated monomer other than a vinyl aromatic compound (eg, 1-butene, 1-pentene, 1-hexene, butadiene, isoprene, as long as the object and effects of the present invention are not hindered. , Methyl vinyl ether, methyl methacrylate, vinyl acetate, etc.) and may have a small amount (preferably 10% by mass or less of the polymer block A) of one or more structural units.

Examples of the conjugated diene compound constituting the polymer block B in the hydrogenated block copolymer (a) include, for example, butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, Examples thereof include 3-hexadiene, and the polymer block B can be formed from one or more of these conjugated diene compounds. Among them, it is particularly preferable that the polymer block B is formed from both butadiene and isoprene. When the polymer block B is formed from both butadiene and isoprene, the surface of the molded article obtained from the thermoplastic elastomer composition is not tacky, and the polymer block B is formed from butadiene alone or isoprene alone. As compared with the above, the holding power of the non-aromatic rubber softener (b) in the hydrogenated block copolymer (a) is increased, and bleed out of the non-aromatic rubber softener (b) can be suppressed.

結合 The bonding form of the conjugated diene compound in the polymer block B is not particularly limited. For example, in the case of butadiene, a 1,2-bond and / or a 1,4-bond can be taken, and in the case of isoprene, a 1,2-bond, a 3,4-bond and / or a 1,4-bond can be taken, Any of these bonding forms may be used. Among them, when the polymer block B is formed from butadiene, the proportion of 1,2-linking units may be 20 to 70 mol% and the proportion of 1,4-linking units may be 30 to 80 mol%. preferable. When the polymer block B is formed of isoprene or both butadiene and isoprene, the total of 1,2-linkage units and 3,4-linkage units is 5 to 70 mol%. It is particularly preferable that the content is 5 to 30 mol%.

Further, when the polymer block B is formed of two or more conjugated diene compounds (for example, butadiene and isoprene), the bonding form thereof is completely alternating, random, tapered, or a combination of two or more thereof. be able to.

In the conjugated diene compound constituting the polymer block B in the hydrogenated block copolymer (a), the iodine value of the block copolymer which is an index of the hydrogenation rate of the carbon-carbon double bond based on the conjugated diene unit is: , 10 to 40 g / 100 g. The iodine value is in the range of 10 to 30 g / 100 g from the viewpoint of various physical properties such as heat resistance, weather resistance, rubber elasticity at high temperature, and creep resistance at high temperature of the obtained thermoplastic elastomer composition. And more preferably in the range of 10 to 20 g / 100 g. When the iodine value exceeds 40 g / 100 g, the heat resistance (for example, the degree of coloring at 200 ° C. and the rubber elasticity at a temperature of 100 to 120 ° C.) and the weather resistance of the obtained thermoplastic elastomer composition are reduced. If the amount is less than 10 g / 100 g, the obtained thermoplastic elastomer composition has reduced rubber elasticity at a high temperature (for example, at a temperature of 100 to 120 ° C.) to obtain a thermoplastic elastomer composition having satisfactory performance. Can not.

In the present specification, the iodine value in the block copolymer (a) means a value measured by the following iodine reduction titration. That is, an appropriate amount (approximately 0.1 g to 1 g) of the hydrogenated block copolymer (a) is accurately weighed in an Erlenmeyer flask, 100 ml of chloroform is added to completely dissolve the same, and then the whis solution (0.1 N Add 20 ml of iodine monochloride-acetic acid solution), shake gently, and allow to stand at room temperature for 30 minutes while blocking light. After adding 20 ml of a 0.1 g / ml aqueous solution of potassium iodide and 100 ml of water to this solution, the amount of released iodine was back titrated with a 0.1N aqueous solution of sodium thiosulfate, and the iodine value (I: g / 100g). At this time, the end point of the back titration with a 1N aqueous solution of sodium thiosulfate is determined by visually observing the aqueous phase and the chloroform phase and judging that both are colorless. The same operation is performed without adding the hydrogenated block copolymer (a), and the titration amount (ml) of the 0.1 N aqueous sodium thiosulfate solution at that time is used as a blank value.
I = (B−C) × f × 1.269 / S
I: Iodine value (g / 100g)
S: Weight (g) of the weighed hydrogenated block copolymer (a)
B: Blank titer of 0.1N aqueous sodium thiosulfate (ml)
C: Titration of 0.1N sodium thiosulfate aqueous solution (ml)
f: Factor of 0.1N sodium thiosulfate aqueous solution

The polymer block B may be an unsaturated monomer other than a conjugated diene compound (for example, 1-butene, 1-pentene, 1-hexene, methyl vinyl ether, styrene) unless the object and effects of the present invention are hindered. , Methyl methacrylate, vinyl acetate, etc.) and may have a small amount (preferably 10% by mass or less of the polymer block B) of one or more structural units.

As long as the hydrogenated block copolymer (a) is a hydrogenated product (hydrogenated product) of a block copolymer in which at least one polymer block A and at least one polymer block B are bonded, The bonding mode of the polymer block is not limited, and may be linear, branched, radial, or a bonding mode in which two or more of them are combined. Among them, the bonding form of the polymer block A and the polymer block B is preferably linear. For example, when the polymer block A is represented by A and the polymer block B is represented by B A hydrogenated product of a diblock copolymer of AB, a hydrogenated product of a triblock copolymer of ABA, a hydrogenated product of a tetrablock copolymer of ABAB, Examples include hydrogenated products of a pentablock copolymer of ABABA and BABAB. Among them, a hydrogenated product of an ABA triblock copolymer is preferably used from the viewpoint of easiness of production of the block copolymer, flexibility, rubber elasticity and the like.

The content of the structural unit derived from the vinyl aromatic compound in the hydrogenated block copolymer (a) is in the range of 10 to 65% by mass from the viewpoint of the mechanical strength and flexibility of the thermoplastic elastomer composition. Is preferably, and more preferably in the range of 15 to 35% by mass. The content of the structural unit derived from the vinyl aromatic compound in the hydrogenated block copolymer (a) can be determined by a ¹ H-NMR spectrum or the like.

The hydrogenated block copolymer (a) needs to have a weight average molecular weight after hydrogenation of 200,000 or more, more preferably 250,000 or more. When the weight average molecular weight of the hydrogenated block copolymer (a) is less than 200,000, the rubber elasticity at a high temperature of the thermoplastic elastomer composition produced by the method of the present invention decreases. The upper limit of the weight average molecular weight of the hydrogenated block copolymer (a) is not particularly limited, but is preferably 500,000 or less from the viewpoint of processability of the thermoplastic elastomer composition produced by the method of the present invention.
In addition, the weight average molecular weight referred to in this specification is a molecular weight in terms of polystyrene obtained by gel permeation chromatography (GPC) measurement.

The hydrogenated block copolymer (a) may optionally have a carboxyl group, a hydroxyl group, an acid anhydride group, an amino group, an epoxy group, or the like in a molecular chain and / or at a molecular terminal unless the gist of the present invention is impaired. It may have one or more functional groups.

法 The method for producing the hydrogenated block copolymer (a) used in the present invention is not particularly limited. For example, it can be produced by the following conventionally known anionic polymerization method. That is, using an alkyllithium compound as an initiator, in an organic solvent inert to a polymerization reaction such as n-hexane or cyclohexane, a vinyl aromatic compound or a conjugated diene compound is subjected to block polymerization by a method such as sequential polymerization or coupling. Form a coalescence. Next, the obtained block copolymer is hydrogenated (hydrogenated) in the presence of a hydrogenation catalyst in an inert organic solvent according to a known method to produce a hydrogenated block copolymer (a). be able to.

In the production of the hydrogenated block copolymer (a), a block which is an index of the hydrogenation rate of the carbon-carbon double bond based on the conjugated diene unit constituting the polymer block B mainly composed of a conjugated diene compound. As a method for controlling the iodine value of the copolymer within the range of 10 to 40 g / 100 g, a method commonly used by those skilled in the art can be employed. For example, appropriately adjusting the reaction conditions such as the reaction temperature and the reaction time, and the amount of the hydrogenation catalyst used, for example, when using a Ziegler-based catalyst that uses a nickel compound / organoaluminum compound in combination as the hydrogenation catalyst, On the other hand, the amount of the organoaluminum compound used can be reduced, and the degree of progress of the hydrogenation reaction can be examined by appropriately sampling the reaction solution to obtain a target hydrogenation rate.

The block copolymer (a1) optionally used in the present invention contains at least one polymer block A1 mainly composed of a vinyl aromatic compound and at least one polymer block B1 mainly composed of a conjugated diene compound. Block copolymer.

In the block copolymer (a1), examples of the vinyl aromatic compound constituting the polymer block A1 include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, pt- Examples thereof include butylstyrene, 2,4-dimethylstyrene, 2,4,6-trimethylstyrene, monofluorostyrene, monochlorostyrene, dichlorostyrene, vinylnaphthalene, and vinylanthracene. It can be formed from one or more group III compounds. Among them, the polymer block A1 is preferably formed from styrene or p-methylstyrene.

The polymer block A1 may optionally contain an unsaturated monomer other than the vinyl aromatic compound (eg, 1-butene, 1-pentene, 1-hexene, butadiene, isoprene, as long as the object and effects of the present invention are not hindered. , Methyl vinyl ether, methyl methacrylate, vinyl acetate, etc.) and may have a small amount of one or more structural units (preferably 10% by mass or less of the polymer block A1).

Examples of the conjugated diene compound constituting the polymer block B1 in the block copolymer (a1) include butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-pentadiene. Hexadiene can be mentioned, and the polymer block B1 can be formed from one or more of these conjugated diene compounds. Among them, the polymer block B1 is particularly preferably formed from butadiene and / or isoprene. From the viewpoint of heat resistance (for example, the degree of coloring at 200 ° C.) of the obtained thermoplastic elastomer composition, the polymer block B1 is preferably made of isoprene. It is particularly preferred that they are formed.

結合 The bonding form of the conjugated diene compound in the polymer block B1 is not particularly limited. For example, in the case of butadiene, a 1,2-bond and / or a 1,4-bond can be taken, and in the case of isoprene, a 1,2-bond, a 3,4-bond and / or a 1,4-bond can be taken, Any of these bonding forms may be used. Among them, when the polymer block B is formed from butadiene, the ratio of 1,2-bond units is 0 from the viewpoint of heat resistance (for example, rubber elasticity at a temperature of 100 to 120 ° C.) of the obtained composition. It is preferable that the proportion of the 1,4-linking unit is 5 to 100 mol%. When the polymer block B1 is formed of isoprene or both butadiene and isoprene, the obtained composition has a heat resistance (for example, rubber elasticity at a temperature of 100 to 120 ° C). , 3,4-linking unit and 1,2-linking unit are preferably 30 to 95 mol%, particularly preferably 45 to 95 mol%.

When the polymer block B1 is formed of two or more conjugated diene compounds (for example, butadiene and isoprene), their bonding forms are completely alternated, random, tapered, or a combination of two or more thereof. be able to.

In order to control the bonding form of the polymer block B1 in the block copolymer (a1), ethers such as dimethyl ether, diethyl ether and tetrahydrofuran are used as a co-catalyst at the time of polymerization; ethylene glycol dimethyl ether, diethylene glycol dimethyl ether and the like. Glycol ethers; Lewis bases such as amines such as triethylamine, N, N, N ', N'-tetramethylenediamine and N-methylmorpholine can be added.
One of these Lewis bases may be added alone, or two or more may be mixed and added. The amount of the Lewis base to be added is determined by the degree to which the bonding form of the conjugated diene compound unit constituting the polymer block B1 is controlled, and is not strictly limited. It is in the range of 0.1 to 1000 moles per 1 gram atom of lithium contained in the lithium compound or dilithium compound, and more preferably 1 to 100 moles.

The polymer block B1 may be an unsaturated monomer other than a conjugated diene compound (for example, 1-butene, 1-pentene, 1-hexene, methyl vinyl ether, styrene) as long as the object and effects of the present invention are not hindered. , Methyl methacrylate, vinyl acetate, etc.) may have a small amount (preferably not more than 10% by mass of the polymer block B1) of one or more structural units.

As long as the block copolymer (a1) is a block copolymer in which at least one polymer block A1 and at least one polymer block B1 are bonded, the bonding mode of the polymer blocks is not limited. , Linear, branched, radial, or a combination of two or more of them. Among them, the bonding form of the polymer block A1 and the polymer block B1 is preferably linear, for example, when the polymer block A1 is represented by A1 and the polymer block B1 is represented by B1. A1-B1 diblock copolymer, A1-B1-A1 triblock copolymer, A1-B1-A1-B1 tetrablock copolymer, A1-B1-A1-B1-A1, B1- A1-B1-A1-B1 pentablock copolymer and the like can be mentioned. Among them, the triblock copolymer of A1-B1-A1 is preferably used from the viewpoint of easiness of production of the block copolymer, flexibility, rubber elasticity and the like.

The content of the structural unit derived from the vinyl aromatic compound in the block copolymer (a1) is preferably in the range of 10 to 65% by mass from the viewpoint of the mechanical strength, flexibility and the like of the thermoplastic elastomer composition. More preferably, it is within the range of 15 to 35% by mass. In addition, the content of the structural unit derived from the vinyl aromatic compound in the block copolymer (a1) can be determined by a ¹ H-NMR spectrum or the like.

There is no particular limitation on the weight average molecular weight of the block copolymer (a1), but the processability of the thermoplastic elastomer composition of the present invention and the reduction of bumps (micro defects in the molded article) of the molded article made of such a composition are reduced. From the viewpoint, it is usually preferably in the range of 50,000 to 200,000, and more preferably in the range of 50,000 to 150,000. In addition, the weight average molecular weight referred to in this specification is a molecular weight in terms of polystyrene obtained by gel permeation chromatography (GPC) measurement.

The block copolymer (a1) may have a functional group such as a carboxyl group, a hydroxyl group, an acid anhydride group, an amino group, an epoxy group, etc., in the molecular chain and / or at the molecular terminal, unless the gist of the present invention is impaired. Or one or more of these.

法 The method for producing the hydrogenated block copolymer (a1) optionally used in the present invention is not particularly limited, and for example, it can be produced by the following conventionally known anionic polymerization method. That is, using an alkyllithium compound as an initiator, in an organic solvent inert to a polymerization reaction such as n-hexane or cyclohexane, a vinyl aromatic compound or a conjugated diene compound is subjected to block polymerization by a method such as sequential polymerization or coupling. It can be manufactured by forming a coalescence.

In addition, when mix | blending a block copolymer (a1), the compounding quantity is the range of 99: 1-86: 14 as a mass ratio of a hydrogenated block copolymer (a) and a block copolymer (a1). And more preferably in the range of 96: 4 to 86:14. When the blending ratio of the block copolymer (a1) to the hydrogenated block copolymer (a) exceeds 86:14, coloring of the obtained thermoplastic elastomer composition at 200 ° C. becomes severe and In the molded article comprising the thermoplastic elastomer composition produced by the method of the present invention, the number of bumps (micro defects in the molded article) increases rapidly, and the surface condition of the molded article deteriorates. By adjusting the blending amount of the block copolymer (a1) to the hydrogenated block copolymer (a) within the above range, the surface state and heat resistance of the obtained thermoplastic elastomer composition and the molded article obtained therefrom (for example, The rubber elasticity at a high temperature (for example, a temperature of 100 to 120 ° C.) can be further improved without deteriorating the degree of coloring at 200 ° C.).

As the non-aromatic rubber softener (b) used in the present invention, any of conventionally known non-aromatic rubber softeners can be used, and among them, non-aromatic mineral oil or liquid Alternatively, a low molecular weight synthetic softener is suitable. As the softener (b) for the non-aromatic rubber, only one kind may be used, or two or more kinds may be used in combination.
In general, a mineral oil-based rubber softener called a process oil or an extender oil used for softening, increasing the volume of a rubber, and improving processability is a combination of an aromatic ring, a naphthene ring, and a paraffin chain. A mixture in which the number of carbon atoms in the paraffin chain occupies 50% or more of the total number of carbon atoms is called paraffinic, and those having 30 to 45% of carbon atoms in the naphthene ring are naphthenic or aromatic. Those having more than 30% of carbon atoms are called aromatic.
In the present invention, among the above-described process oils, paraffin-based process oils and naphthene-based process oils can be used. Other than these, white oil, mineral oil, low molecular weight copolymer (oligomer) of ethylene and α-olefin, paraffin wax, liquid paraffin and the like can be used. Among these, in the present invention, a paraffin-based process oil and / or a naphthene-based process oil are preferably used as the softener (b) for the non-aromatic rubber.

When an aromatic rubber softener such as an aromatic process oil is used in place of the non-aromatic rubber softener (b), the vinyl in the hydrogenated block copolymer (a) is used. The polymer block composed of the aromatic compound is attacked, and the physical properties of the thermoplastic elastomer composition, particularly, the mechanical strength and the rubber elasticity are significantly reduced.

Further, in the present invention, from the viewpoint of improving the heat resistance of the obtained thermoplastic elastomer composition, particularly from the viewpoint of maintaining the rubber elasticity at a high temperature, the dynamics of the non-aromatic rubber softener (b) at 40 ° C. It is preferable that the viscosity (mm ² / s) satisfies the following formula [1].
Bv (mm ² / s) ≧ 3 × 10 ⁷ / Mwa [1]
[In the above formula, Bv indicates the kinematic viscosity at 40 ° C. of the softener (b) for non-aromatic rubber, and Mwa indicates the weight average molecular weight of the hydrogenated block copolymer (a). ]
The kinematic viscosity (mm ² / s) at 40 ° C. of the softener for non-aromatic rubber in the present specification refers to the viscosity measured at a temperature of 40 ° C. using a B-type viscometer at 40 ° C. The value of the quotient divided by the density of the non-aromatic rubber softener (b).

The blending amount of the non-aromatic rubber softener (b) is 100 parts by mass of the hydrogenated block copolymer (a) or the total amount of the hydrogenated block copolymer (a) and the block copolymer (a1). Is required to be 50 to 250 parts by mass, preferably 80 to 200 parts by mass. The blending amount of the non-aromatic rubber softener (b) is 100 parts by mass of the hydrogenated block copolymer (a) or the total amount of the hydrogenated block copolymer (a) and the block copolymer (a1). If it is less than 50 parts by mass, the flexibility of the thermoplastic elastomer composition obtained in the present invention will be inferior and the moldability will be reduced. On the other hand, when the amount exceeds 250 parts by mass, the mechanical strength of the molded article comprising the thermoplastic elastomer composition obtained by the present invention is insufficient, and the softener (b) for non-aromatic rubber bleeds out. .

パ ー The peroxide-decomposable olefin-based resin (c) used in the present invention refers to an olefin-based resin which is thermally decomposed by heat treatment in the presence of a peroxide to reduce the molecular weight and increase the fluidity. Examples of the peroxide-decomposable olefin-based resin (c) include copolymers of polypropylene and propylene with a small amount of other α-olefins such as ethylene, 1-butene, 1-hexene and 1-octene, and Examples thereof include those generally obtained by electron beam crosslinking and generally called high melt strength polypropylene (HMS-PP), and one or more of these can be used. Among them, a copolymer of propylene and a small amount of an α-olefin and polypropylene are preferably used because the rubber elasticity of the thermoplastic elastomer composition at high temperatures is improved, and is referred to as a block type or a homo type. Are more preferably used. Homotype polypropylene means a homopolymer of propylene, and refers to isotactic polypropylene, syndiotactic polypropylene, atactic polypropylene and the like. Copolymers of propylene and α-olefins or other monomers are roughly classified into block types and random types, and those in which the bonding form of each component is close to block are block types, and the bonding form of each component is close to random. Those are generally referred to as random types.

ポ リ プ ロ ピ レ ン As the above-mentioned copolymer of polypropylene, propylene and a small amount of ethylene, 1-butene, 1-hexene, 1-octene and the like, those produced using a single-site catalyst, a Ziegler catalyst or the like can be used.

The amount of the peroxide-decomposable olefin-based resin (c) is 100 parts by mass of the hydrogenated block copolymer (a) or the total amount of the hydrogenated block copolymer (a) and the block copolymer (a1). On the other hand, it is necessary to be 20 to 300 parts by mass, and more preferably 20 to 150 parts by mass. If the amount of the peroxide-decomposable olefin resin (c) is less than the above-mentioned amount, the molded article obtained from the thermoplastic elastomer composition loses its surface smoothness. The rubber elasticity of the plastic elastomer composition at a high temperature (for example, a temperature of 100 to 120 ° C.) is lost, and the compression set is undesirably increased.

で は In the present invention, an organic peroxide (d) is used together with the above components. As the organic peroxide (d), any organic peroxide having a crosslinking action under dynamic conditions may be used, and either an aromatic peroxide or an aliphatic peroxide can be used. Further, one kind of organic peroxide may be used, or two or more kinds of organic peroxides may be used. Specific examples of the organic peroxide (d) that can be used in the present invention include 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di Examples include (benzoylperoxy) hexane, t-butylperoxybenzoate, dicumyl peroxide, diisopropylbenzohydroperoxide, 1,3-bis- (t-butylperoxyisopropyl) benzene, and benzoyl peroxide. , One or more of these can be used.

The amount of the organic peroxide (d) to be used can be arbitrarily selected, and the thermoplastic elastomer composition obtained by the method of the present invention has an effect of improving rubber elasticity and flow at a high temperature (for example, at a temperature of 100 to 120 ° C.). From the viewpoint of properties, it is usually preferably 0.3 to 3 parts by mass based on 100 parts by mass of the components (a), (b) and (c), and optionally the component (a1). More preferably, the amount is 0.3 to 1.5 parts by mass. When a peroxide-crosslinkable olefin-based resin (f) described below, which can be blended as needed, is blended, the amount of the organic peroxide (d) used is determined by the components (a), (b) and It is preferable that the amount is 0.3 to 3 parts by mass based on 100 parts by mass of the component (a1) and the component (f). When the amount of the organic peroxide (d) is less than 0.3 parts by mass, the rubber elasticity of the thermoplastic elastomer composition at a high temperature is inferior and the compression set tends to be large. When the amount is more than the mass part, the surface of the obtained molded article tends to be rough and fine (fine defects).

In the present invention, a crosslinking aid (e) is further used. As the crosslinking assistant (e), a polyfunctional monomer is preferably used. Specific examples thereof include vinyl polyfunctional monomers such as triallyl isocyanurate and divinylbenzene, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, and triethylene glycol. An acrylic polyfunctional monomer such as dimethacrylate can be used.
The amount of the crosslinking assistant (e) is not particularly limited, but is generally preferably in the range of 0.5 to 3 parts by mass with respect to 1 part by mass of the organic peroxide (d).

で は In the present invention, a peroxide-crosslinkable olefin-based resin (f) may be further added, if necessary. The peroxide-crosslinked olefin-based resin (f) refers to an olefin-based resin which undergoes heat treatment in the presence of a peroxide to be crosslinked to increase the molecular weight. Examples of the peroxide-crosslinked olefin resin (f) include polyethylene, copolymers of ethylene and a small amount of propylene, 1-hexene, 1-octene, and the like. One or more of these may be used. Can be used. Among them, polyethylene is preferably used from the viewpoint of exhibiting rubber elasticity under high temperature (for example, a temperature of 100 to 120 ° C.).

In some cases, it is preferable to mix the peroxide crosslinked olefin resin (f) depending on the type of the peroxide decomposable polyolefin (c). That is, when polypropylene called a homo type is used as the peroxide decomposable polyolefin (c), the blending of the peroxide crosslinked olefin resin (f) is optional. On the other hand, when polypropylene called a block type is used as the peroxide-decomposed polyolefin (c), the peroxide-crosslinked olefin-based resin (f) is used in view of rubber elasticity of the obtained thermoplastic elastomer composition at a high temperature. It is very preferable to mix When a block type is used as the peroxide decomposable polyolefin (c) and the peroxide crosslinked olefin resin (f) is not blended, the obtained thermoplastic elastomer composition has a high temperature (for example, a temperature of 100 to 120 ° C.). The compression set at the bottom tends to be large, and the rubber elasticity at high temperatures is inferior, and the oil resistance tends to be inferior.

The density of the peroxide-crosslinkable olefin-based resin (f) that can be blended as required in the present invention is preferably 0.94 g / cm ³ or more, and more preferably 0.95 g / cm ³ or more. More preferred. If the density of the peroxide-crosslinked olefin resin (f) is less than 0.94 g / cm ³ , the rubber elasticity of the thermoplastic elastomer composition at a high temperature (for example, at a temperature of 100 to 120 ° C) tends to be inferior.

The peroxide-crosslinked olefin-based resin (f) has a melt flow rate (MFR) of 0.5 to 50 g / 10 minutes under the conditions of 190 ° C. and 21.2 N. It is preferable from the viewpoint of the fluidity of the product, and more preferably 1 to 40 g / 10 minutes.

The amount of the peroxide-crosslinkable olefin-based resin (f) that can be compounded as required in the present invention is not particularly limited, but from the viewpoint of fluidity of the obtained thermoplastic elastomer composition, the hydrogenated block copolymer It is preferably 50 parts by mass or less based on 100 parts by mass of the total of the combined (a) or the hydrogenated block copolymer (a) and the block copolymer (a1). If the amount of the peroxide-crosslinked olefin resin (f) exceeds 50 parts by mass, the resulting thermoplastic elastomer composition loses flexibility and bleeds out the softener (b) for non-aromatic rubber. Tend to be remarkable, which is not desirable.

で は In the present invention, an inorganic filler can be blended if necessary. By blending the inorganic filler, it is possible to improve some physical properties such as compression set of the molded article made of the thermoplastic elastomer composition of the present invention, and further reduce the cost by increasing the amount depending on the inorganic filler used. be able to. Examples of the inorganic filler that can be used include, for example, calcium carbonate, talc, magnesium hydroxide, mica, clay, barium sulfate, natural silicic acid, synthetic silicic acid, titanium oxide, and carbon black. Alternatively, two or more kinds can be used.

In the present invention, if necessary, a reinforcing resin such as poly α-methylstyrene, a flame retardant, an antioxidant, a heat stabilizer, an ultraviolet absorber, a light stabilizer, an antistatic agent, a release agent, a foaming agent, Pigments, dyes, brighteners and the like can be used.

The dynamically crosslinked thermoplastic elastomer composition of the present invention comprises the components (a), (b), (c), (d) and (e) described above, and optionally the component (a1), and optionally the component (a1). (F) If necessary, a mixture containing other components such as the above-mentioned inorganic filler is kneaded together in a single-stage process in a heated and molten state. This makes it possible to produce a dynamically crosslinked thermoplastic elastomer composition having excellent properties by a very simple process.
In addition, as another method, the components (a), (b) and (c), and optionally the component (a1), the component (f) if necessary, and the inorganic filler described above if necessary. Is kneaded in a heated and molten state in the presence of components (d) and (e), and then the components (a), (b) and (c), and optionally the component (a1), if necessary A method of adding and kneading the component (f) and, if necessary, the remaining components of other components such as the above-mentioned inorganic filler, the components (a), (b) and (c), and optionally the component (f). a1) If necessary, component (f) and, if necessary, all other components such as the above-mentioned inorganic filler are kneaded in a heated and molten state, and then components (d) and (e) are added and kneaded. Method may be adopted, but from the viewpoint of easy operation, all components How to kneading is preferably in a heated molten state collectively in one step process.
Here, the “dynamic crosslinking” in the present specification refers to the components (a), (b), (c), (d) and (e) described above, and optionally the component (a1), if necessary. This means that a mixture containing the component (f) and, if necessary, other components is kneaded in a heated and molten state and crosslinked while applying shear stress from the outside.

混 The kneading temperature for obtaining the dynamically crosslinked thermoplastic elastomer composition of the present invention is preferably selected from the range of 150 to 250 ° C. In the case of batch production in one step, the first half of the kneading is performed at a temperature at which the half-life of the organic peroxide (d) is half or more of the total kneading time, and the latter half of the kneading is performed at a temperature of the organic peroxide (d). It is preferable to carry out kneading at a temperature at which the half-life is less than 1/2 of the total kneading time, since the physical properties and moldability of the obtained thermoplastic elastomer composition are improved. When kneading is performed at a temperature at which the half-life of the organic peroxide (d) is less than half of the total kneading time in the first half of the kneading, the hydrogenated block copolymer (a) or the hydrogenated block copolymer (a) The crosslinking reaction proceeds before the block copolymer (a1) is finely dispersed in the composition, and the resulting thermoplastic elastomer composition tends to have reduced physical properties and moldability, which is not preferred. In the present specification, the first half of the kneading generally refers to the time from the start of kneading to about half of the total kneading time, and thereafter the latter half of the kneading.

Batch kneading in a heated and melted state to obtain the dynamically crosslinked thermoplastic elastomer composition of the present invention is a method conventionally used for melt kneading of a thermoplastic polymer, for example, a single screw extruder, a twin screw extruder. And a melt kneader such as a Banbury mixer, a heating roll, a Brabender or various kneaders.

The dynamically crosslinked thermoplastic elastomer composition of the present invention obtained by the above method can be molded by various molding methods, for example, known methods such as injection molding, press molding, extrusion molding, and calendar molding.
From the dynamically crosslinked thermoplastic elastomer composition of the present invention, a molded article having excellent flexibility, mechanical strength and rubber elasticity can be obtained, for example, a sheet, a film, a plate, a tube, a hose, a belt and the like. Uses of footwear such as sports shoes and fashion sandals; Uses of home appliances such as TVs, stereos, vacuum cleaners and refrigerators; Sealing packing used for doors and window frames of buildings; Bumper parts, body panels, weather strips, etc. It can be effectively used for a wide range of applications such as various kinds of grips for scissors, drivers, toothbrushes, ski poles and the like.

Hereinafter, the present invention will be described specifically with reference to Examples and the like, but the present invention is not limited to the following Examples.
In the following examples, various physical properties (hardness, tensile strength, tensile elongation, compression set, oil resistance, surface state and heat resistance) of a molded article obtained from the thermoplastic elastomer composition are measured by the following methods. Or rated.

[1] Hardness:
"Type A" hardness was measured according to JIS K-6253.

[2] Tensile strength and tensile elongation:
A dumbbell-shaped No. 5 test piece was punched out from the injection molded sheet obtained in the following example, and a tensile test was performed in accordance with JIS K-6251, and the strength and elongation at break were measured to determine the tensile strength and tensile elongation. And

[3] Compression set:
The injection molded sheet obtained in the following example was punched into a circular size having a diameter of 29 mm, and six of them were stacked and pressed at a temperature of 200 ° C. and a pressure of 2.9 MPa to produce a test piece. According to JIS K-6262, after compressing at a temperature of 100 ° C. and 120 ° C. for 22 hours at a compression ratio of 25%, the compression was released and the compression set after leaving the plate to stand at 25 ° C. for 30 minutes was measured. .

[4] Oil resistance (mass swelling ratio):
A test piece having a size of length x width x thickness = 40 mm x 20 mm x 2 mm was punched out from the injection molded sheet obtained in the following example, and was cut at 100 ° C using No. 2 swelling oil according to JIS K-6258. A time oil resistance test was performed, and the mass increase rate after the oil resistance test with respect to the mass before the oil resistance test was determined, and the result was defined as the mass swelling rate.

[5] Surface condition of molded product:
The surface of the injection-molded sheet obtained in the following example was visually observed, and a case where the surface had no roughness and a smooth surface was evaluated as good (○), and a case where the roughness occurred was evaluated as poor (×). evaluated.

[6] Heat resistance of molded product:
The injection-molded sheet obtained in the following example was left in a drier at 200 ° C., and after 1.5 hours, the degree of coloring of the sheet was visually observed. Were evaluated as acceptable (△), and those colored yellow to brown were evaluated as poor (x).

The contents and abbreviations of each component used in the following examples are as follows.
<1> -1: hydrogenated block copolymer (a)
Synthesis Example 1
Into a pressure-resistant container which was purged with nitrogen and dried, 50 L of cyclohexane as a solvent and 29 ml of sec-butyllithium (10% by mass, cyclohexane solution) as an initiator were charged, and after heating to 50 ° C., 500 ml of styrene was added and added for 30 minutes. Polymerization was conducted, and styrene (370 ml) was further added, followed by polymerization for 30 minutes. Subsequently, 5600 ml of a mixture of isoprene and butadiene (mass ratio: isoprene / butadiene = 50/50) was added to the reaction solution, and polymerization was performed for 3 hours. Thereafter, 870 ml of styrene was further added and polymerization was performed for 30 minutes. The reaction was stopped by adding 0.5 ml to obtain a polymerization reaction solution containing a block copolymer. Next, a Ziegler catalyst composed of triethylaluminum and nickel 2-ethylhexanoate was added to the polymerization reaction solution, and a hydrogenation reaction was performed at 75 ° C. for 5 hours under a hydrogen pressure atmosphere of 0.8 MPa. A hydrogenated block copolymer having the properties shown below (hereinafter referred to as hydrogenated block copolymer (a) -1) was obtained.

Synthesis Example 2 and Synthesis Example 3
In Synthesis Example 1, the degree of progress of the reaction was tracked by analysis during the hydrogenation reaction, and the polymerization reaction was performed in the same manner as in Synthesis Example 1 except that the reaction time was adjusted so that the iodine value (hydrogenation ratio) reached a target value. And a hydrogenation reaction was carried out to obtain a hydrogenated block copolymer (a) -2 and a hydrogenated block copolymer (a) -3 having the properties shown in Table 1.

Synthesis Example 4
Into a pressure-resistant container that has been purged with nitrogen and dried, 60 L of cyclohexane as a solvent and 19 ml of sec-butyllithium (10% by mass, cyclohexane solution) as an initiator are charged, and after heating to 50 ° C., 500 ml of styrene is added and added for 30 minutes. Polymerization was performed, and 270 ml of styrene was further added, followed by polymerization for 30 minutes. Subsequently, 4930 ml of a mixture of isoprene and butadiene (mass ratio: isoprene / butadiene = 60/40) was added to the reaction solution, and polymerization was carried out for 3 hours. Thereafter, 770 ml of styrene was further added, followed by polymerization for 30 minutes, and then 1 ml of methanol. Was added to stop the reaction, thereby obtaining a polymerization reaction solution containing a block copolymer. Next, a Ziegler catalyst composed of triethylaluminum and nickel 2-ethylhexanoate was added to the polymerization reaction solution, and the reaction was carried out at 75 ° C. under a hydrogen pressure atmosphere of 0.8 MPa. By tracking and adjusting the reaction time so that the iodine value (hydrogenation ratio) becomes a target value, a hydrogenated block copolymer having the properties shown in Table 1 (hereinafter referred to as a hydrogenated block copolymer ( a) -4) was obtained.

Synthesis Example 5
Into a pressure-resistant container that has been purged with nitrogen and dried, 60 L of cyclohexane as a solvent and 19 ml of sec-butyllithium (10% by mass, cyclohexane solution) as an initiator are charged, and after heating to 50 ° C., 500 ml of styrene is added and added for 30 minutes. Polymerization was performed, and 270 ml of styrene was further added, followed by polymerization for 30 minutes. Subsequently, 4980 ml of a mixture of isoprene and butadiene (mass ratio: isoprene / butadiene = 40/60) was added to the reaction solution, and polymerization was carried out for 3 hours. Thereafter, 770 ml of styrene was further added, followed by polymerization for 30 minutes, and then 1 ml of methanol. Was added to stop the reaction, thereby obtaining a polymerization reaction solution containing a block copolymer. Next, a Ziegler catalyst composed of triethylaluminum and nickel 2-ethylhexanoate was added to the polymerization reaction solution, and the reaction was carried out at 75 ° C. under a hydrogen pressure atmosphere of 0.8 MPa. By tracking and adjusting the reaction time so that the iodine value (hydrogenation ratio) becomes a target value, a hydrogenated block copolymer having the properties shown in Table 1 (hereinafter referred to as a hydrogenated block copolymer ( a) -5).

Synthesis Example 6
60 L of cyclohexane as a solvent and 13 ml of sec-butyllithium (10% by mass, cyclohexane solution) as an initiator were charged into a pressure-resistant container which had been purged with nitrogen and dried, heated to 50 ° C., and 400 ml of styrene was added for 30 minutes. Polymerization was performed, and 260 ml of styrene was further added, and polymerization was performed for 30 minutes. Subsequently, 4310 ml of a mixture of isoprene and butadiene (mass ratio: isoprene / butadiene = 50/50) was added to the reaction solution, and polymerization was carried out for 3 hours. Thereafter, 660 ml of styrene was further added, followed by polymerization for 30 minutes, and 0.7 ml of methanol. Was added to stop the reaction, thereby obtaining a polymerization reaction solution containing a block copolymer. Next, a Ziegler catalyst composed of triethylaluminum and nickel 2-ethylhexanoate was added to the polymerization reaction solution, and the reaction was carried out at 75 ° C. under a hydrogen pressure atmosphere of 0.8 MPa. By tracking and adjusting the reaction time so that the iodine value (hydrogenation ratio) becomes a target value, a hydrogenated block copolymer having the properties shown in Table 1 (hereinafter referred to as a hydrogenated block copolymer ( a) -6).

Synthesis Example 7
Into a pressure-resistant container which had been purged with nitrogen and dried, 40 L of cyclohexane as a solvent and 114 ml of sec-butyllithium (10% by mass, cyclohexane solution) as an initiator were charged, and after raising the temperature to 50 ° C., 800 ml of styrene was added and added for 30 minutes. Polymerization was conducted, and styrene (370 ml) was further added, followed by polymerization for 30 minutes. Subsequently, 7540 ml of a mixture of isoprene and butadiene (mass ratio: isoprene / butadiene = 50/50) was added to the reaction solution, and polymerization was carried out for 3 hours. Thereafter, 1170 ml of styrene was further added, polymerization was carried out for 30 minutes, and 6 ml of methanol was added. The reaction was stopped to obtain a polymerization reaction solution containing the block copolymer. Next, a Ziegler catalyst composed of triethylaluminum and nickel 2-ethylhexanoate was added to the polymerization reaction solution, and the reaction was carried out at 75 ° C. under a hydrogen pressure atmosphere of 0.8 MPa. By tracking and adjusting the reaction time so that the iodine value (hydrogenation ratio) becomes a target value, a hydrogenated block copolymer having the properties shown in Table 1 (hereinafter referred to as a hydrogenated block copolymer ( a) -7).

<1> -2: Block copolymer (a1)
Synthesis Example 8
Into a pressure-resistant container which has been purged with nitrogen and dried, 60 L of cyclohexane as a solvent, 150 ml of sec-butyllithium (10% by mass, cyclohexane solution) as an initiator, and 400 ml of tetrahydrofuran are charged, and after heating to 50 ° C., 1100 ml of styrene is added. For 30 minutes, and 300 ml of styrene was further added for 30 minutes. Subsequently, 15300 ml of isoprene was added to the reaction solution and polymerization was carried out for 3 hours. Thereafter, 1400 ml of styrene was further added and polymerization was carried out for 30 minutes. The reaction was stopped by adding 14 ml of methanol and a block copolymer having the properties shown in Table 2 was added. (A1) -1 was obtained.

Synthesis Example 9
Into a pressure-resistant container which had been purged with nitrogen and dried, 60 L of cyclohexane as a solvent, 120 ml of sec-butyllithium (10% by mass, cyclohexane solution) as an initiator, and 100 ml of N, N, N ', N'-tetramethylenediamine were charged. After the temperature was raised to 50 ° C., 550 ml of styrene was added for polymerization for 30 minutes, and 150 ml of styrene was added for polymerization for 30 minutes. Subsequently, 17200 ml of isoprene was added to the reaction solution and polymerization was carried out for 3 hours. Thereafter, 700 ml of styrene was added and polymerization was carried out for 30 minutes. The reaction was stopped by adding 13.0 ml of methanol and the block copolymer having the properties shown in Table 2 was added. Polymer (a1) -2 was obtained.

<2> Softener for non-aromatic rubber (b):
(B) -1: “Diana Process PW-380” manufactured by Idemitsu Kosan Co., Ltd. [paraffin-based process oil; kinematic viscosity = 381.6 mm ² / s (40 ° C.), pour point = −15 ° C., ring analysis: CN = 27.0%, CP = 73.0%]
(B) -2: “Diana Process PW-90” manufactured by Idemitsu Kosan Co., Ltd. [paraffin-based process oil; kinematic viscosity = 95.54 mm ² / s (40 ° C.), pour point = −15 ° C., ring analysis: CN = 29.0%, CP = 71.0%]

<3> peroxide decomposable olefin resin (c):
(C) -1: “Grand Polypro J704” manufactured by Grand Polymer Co., Ltd. [Block type polypropylene resin; MFR = 5 g / 10 min (230 ° C., 21.2 N), density = 0.90 g / cm ³ ]
(C) -2: “Grand Polypropylene B701” manufactured by Grand Polymer Co., Ltd. [Block type polypropylene resin; MFR = 0.5 g / 10 min (230 ° C., 21.2 N), density = 0.90 g / cm ³ ]
(C) -3: "Novatech PP MA3" manufactured by Nippon Polychem Co., Ltd. [homotype polypropylene resin; MFR = 10 g / 10 min (230 ° C., 21.2 N), density = 0.90 g / cm ³ ]

<4> Organic peroxide (d):
Nippon Oil & Fats Co., Ltd. “Perhexa 25B-40” [2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 40 mass% content, carrier: silica]

<5> Crosslinking aid (e):
"Taik M-60" manufactured by Nippon Kasei Co., Ltd. (triallyl isocyanurate, 60% by mass-containing product, carrier: diatomaceous earth)

<6> Peroxide crosslinked olefin resin (f):
(F) -1: "Novatec HJ490" manufactured by Nippon Polychem Co., Ltd. [high-density polyethylene resin; MFR = 20 g / 10 min (190 ° C., 21.2 N), density = 0.958 g / cm ³ ]
(F) -2: "Novatech LJ800" manufactured by Nippon Polychem Co., Ltd. [low-density polyethylene resin; MFR = 20 g / 10 min (190 ° C., 21.2 N); density = 0.918 g / cm ³ ]

<< Examples 1-10 >>
(1) The above-mentioned hydrogenated block copolymer (a), softener for non-aromatic rubber (b), peroxide-decomposable olefin-based resin (c), organic peroxide (d), crosslinking aid (e) ) And, if necessary, a peroxide-crosslinked olefin-based resin (f) in advance in the amounts shown in Tables 3, 4 and 5 below, and collectively mix them into a twin-screw extruder (Toshiba Machine Co., Ltd.) "TEM-35B"), kneaded at a screw speed of 200 rpm at the temperatures shown in Tables 3, 4 and 5 below, extruded into strands, cut, and dynamically crosslinked thermoplastic. A pellet of the elastomer composition was produced.
(2) Using the pellet obtained in the above (1), an injection molding machine (“IS-55EPN” manufactured by Toshiba Machine Co., Ltd., mold clamping pressure 55 × 10 ³ kg), melting temperature 230 ° C., mold Injection molding was performed under the condition of a temperature of 40 ° C. to produce a sheet-like molded product having a length × width × thickness of 110 mm × 110 mm × 2 mm. The hardness, tensile strength, tensile elongation, compression set, oil resistance, surface state, and heat resistance of this molded product were measured or evaluated by the above-described methods, and as shown in Tables 3, 4, and 5 below. Met.

<< Examples 11, 12, 13 >>
(1) The above hydrogenated block copolymer (a), block copolymer (a1), softener for non-aromatic rubber (b), peroxide decomposable olefin resin (c), organic peroxide ( d), the crosslinking assistant (e), and, if necessary, the peroxide-crosslinkable olefin-based resin (f) in advance in the amounts shown in Table 5 below, and collectively mix them into a twin-screw extruder (Toshiba After supplying to the “TEM-35B” manufactured by Kikai Co., Ltd., and kneading at a temperature shown in Table 5 below at a screw rotation speed of 200 rpm, extruding into a strand, cutting, and dynamically cross-linking the thermoplastic elastomer composition Pellets were produced.
(2) Using the pellet obtained in the above (1), an injection molding machine (“IS-55EPN” manufactured by Toshiba Machine Co., Ltd., mold clamping pressure 55 × 10 ³ kg), melting temperature 230 ° C., mold Injection molding was performed under the condition of a temperature of 40 ° C. to produce a sheet-like molded product having a length × width × thickness of 110 mm × 110 mm × 2 mm. The hardness, tensile strength, tensile elongation, compression set, oil resistance, surface state, and heat resistance of this molded product were measured or evaluated by the above-mentioned methods, and the results were as shown in Table 5 below.

<< Comparative Examples 1-7 >>
(1) The above-mentioned hydrogenated block copolymer (a), softener for non-aromatic rubber (b), peroxide-decomposable olefin-based resin (c), organic peroxide (d), crosslinking aid (e) ) And the peroxide-crosslinked olefin-based resin (f) are mixed in advance in the amounts shown in Tables 6 and 7 below, and are supplied collectively to a twin-screw extruder (“TEM-35B” manufactured by Toshiba Machine Co., Ltd.). After kneading at a temperature shown in Table 6 and Table 7 below at a screw rotation speed of 200 rpm, the mixture was extruded into strands and cut to produce pellets of a dynamically crosslinked thermoplastic elastomer composition.
(2) Using the pellet obtained in the above (1), an injection molding machine (“IS-55EPN” manufactured by Toshiba Machine Co., Ltd., mold clamping pressure 55 × 10 ³ kg), melting temperature 230 ° C., mold Injection molding was performed under the condition of a temperature of 40 ° C. to produce a sheet-like molded product having a length × width × thickness of 110 mm × 110 mm × 2 mm. The hardness, tensile strength, tensile elongation, compression set, oil resistance, surface condition, and heat resistance of this molded product were measured or evaluated by the above-described methods, and the results were as shown in Tables 6 and 7 below. .

As is clear from the results of Tables 3, 4, and 5, in Examples 1 to 13, the hydrogenated block copolymer having a weight average molecular weight of 200,000 or more having an iodine value in the range of 10 to 40 g / 100 g ( a) or a mixture of a hydrogenated block copolymer (a) and a block copolymer (a1), a softener for a non-aromatic rubber (b), a peroxide decomposable olefin resin (c), an organic peroxide (D), a crosslinking aid (e) and, if necessary, a peroxide-crosslinked olefin resin (f), and a hydrogenated block copolymer (a) or a hydrogenated block copolymer (a) Mixing of the peroxide-decomposable olefin resin (c) in the range of 50 to 250 parts by mass of the non-aromatic rubber softener (b) with respect to 100 parts by mass of the total amount with the block copolymer (a1). 20 to 300 parts by mass By setting it within the range, the molded article made of the thermoplastic elastomer composition obtained in Examples 1 to 13 is excellent in flexibility and rubber elasticity, particularly in rubber elasticity under high temperature (100 to 120). (Compressive compression set at a temperature of ° C. is small), and is excellent in mechanical strength and oil resistance, and is excellent in surface characteristics without surface roughness or bleed-out.

Further, by comparing Example 1 with Comparative Example 1 and Example 1 with Comparative Example 2, a block copolymer obtained by hydrogenation so as to have a specific ratio, i.e., an iodine value in the range of 10 to 40 g / 100 g. By using (a), rubber elasticity at a high temperature is excellent (100 to 120 ° C.) without deteriorating heat resistance in comparison with a block copolymer (a) obtained by hydrogenation outside the above range. At low temperatures).

Then, from Example 3 and Examples 11 and 12, when a part of the hydrogenated block copolymer (a) is replaced with the block copolymer (a1), the surface state and heat resistance of the molded product are not deteriorated. It can be seen that the rubber elasticity under high temperature can be further improved.

On the other hand, as is clear from the results in Tables 6 and 7, in Comparative Example 3, when producing the thermoplastic elastomer composition, water having a weight average molecular weight of less than 200,000 was used as the hydrogenated block copolymer (a). By using the added block copolymer (a) -7, the molded article made of the thermoplastic elastomer composition obtained in Comparative Example 3 has extremely large compression set at high temperature, and Poor rubber elasticity.
In Comparative Example 4, since the softening agent (b) for non-aromatic rubber was used in an amount exceeding the amount specified in the present invention, the molding comprising the thermoplastic elastomer composition obtained in Comparative Example 4 was performed. Bleed out of the softener in the product is remarkable.
In Comparative Example 5, a block-type polypropylene was used as the peroxide-decomposable olefin-based resin (c), but the peroxide-crosslinked olefin-based resin (f) was not blended. A molded article made of the thermoplastic elastomer composition has a large compression set at high temperatures and is inferior in rubber elasticity at high temperatures.
In Comparative Example 6, block-type polypropylene was used as the peroxide-decomposable olefin-based resin (c), and polyethylene was used as the peroxide-crosslinked olefin-based resin (f), but the density was 0.94 g / cm. By using (f) -2 of less than ³ , the compression set at a high temperature is large, the rubber elasticity at a high temperature is inferior, and the oil resistance is inferior.
In Comparative Example 7, since the amount of the peroxide-decomposable olefin-based resin (c) was less than the range specified in the present invention, the surface roughness of the molded product was remarkable.

From the dynamically crosslinked thermoplastic elastomer composition of the present invention, a molded article having excellent flexibility, mechanical strength and rubber elasticity can be obtained, for example, a sheet, a film, a plate, a tube, a hose, a belt and the like. Uses of footwear such as sports shoes and fashion sandals; Uses of home appliances such as TVs, stereos, vacuum cleaners and refrigerators; Sealing packing used for doors and window frames of buildings; Bumper parts, body panels, weather strips, etc. It can be effectively used for a wide range of applications such as various kinds of grips for scissors, drivers, toothbrushes, ski poles and the like.

Claims (10)

(I) A block copolymer containing at least one polymer block A mainly composed of a vinyl aromatic compound and at least one polymer block B mainly composed of a conjugated diene compound is hydrogenated. A hydrogenated block copolymer having a weight average molecular weight of 200,000 or more (a) having a combined iodine value of 10 to 40 g / 100 g, a softener for non-aromatic rubber (b), and a peroxide decomposable olefin resin (C), containing an organic peroxide (d) and a crosslinking aid (e); and
(Ii) the amount of the softening agent for non-aromatic rubber (b) is 50 to 250 parts by mass with respect to 100 parts by mass of the hydrogenated block copolymer (a);
(Iii) the amount of the peroxide-decomposable olefin-based resin (c) is 20 to 300 parts by mass with respect to 100 parts by mass of the hydrogenated block copolymer (a);
A thermoplastic elastomer composition obtained by dynamically cross-linking a mixture comprising: The thermoplastic elastomer composition according to claim 1, wherein the polymer block B mainly composed of a conjugated diene compound in the hydrogenated block copolymer (a) is a polymer block composed of butadiene and isoprene. The amount of the organic peroxide (d) is 100 parts by mass based on the total of the hydrogenated block copolymer (a), the softener for non-aromatic rubber (b) and the peroxide-decomposable olefin resin (c). 3 to 3 parts by mass, and the compounding amount of the crosslinking assistant (e) is 0.5 to 3 times by mass the compounding amount of the organic peroxide (d). A thermoplastic elastomer composition. Kinematic viscosity at 40 ° C. Non-aromatic rubber softener (b) (Bv) (mm 2 / s) satisfies the equation (1) below, the thermoplastic according to claim 1 Elastomer composition.
Bv (mm ² / s) ≧ 3 × 10 ⁷ / Mwa [1]
[In the above formula, Bv indicates the kinematic viscosity at 40 ° C. of the softener (b) for non-aromatic rubber, and Mwa indicates the weight average molecular weight of the hydrogenated block copolymer (a). ] Includes hydrogenated block copolymer (a), softener for non-aromatic rubber (b), peroxide-decomposable olefin resin (c), organic peroxide (d), and crosslinking aid (e) The thermoplastic elastomer composition according to any one of claims 1 to 4, wherein the mixture is melt-kneaded under heating and dynamically crosslinked in a single step. (I) A block copolymer containing at least one polymer block A mainly composed of a vinyl aromatic compound and at least one polymer block B mainly composed of a conjugated diene compound is hydrogenated. A hydrogenated block copolymer (a) having a weight-average molecular weight of 200,000 or more and an iodine value of 10 to 40 g / 100 g, at least one polymer block A1 mainly composed of a vinyl aromatic compound and a conjugated diene A block copolymer (a1) containing at least one polymer block B1 mainly composed of a compound, a softener for a non-aromatic rubber (b), a peroxide decomposable olefin resin (c), an organic peroxide ( d) and a crosslinking aid (e); and
(Ii) the mass ratio of the hydrogenated block copolymer (a) to the block copolymer (a1) is 99: 1 to 86:14;
(Iii) The compounding amount of the softening agent for non-aromatic rubber (b) is 50 to 250 parts by mass with respect to 100 parts by mass in total of the hydrogenated block copolymer (a) and the block copolymer (a1). And;
(Iv) The peroxide-decomposable olefin resin (c) is used in an amount of 20 to 300 parts by mass based on 100 parts by mass of the total of the hydrogenated block copolymer (a) and the block copolymer (a1). is there;
A thermoplastic elastomer composition obtained by dynamically cross-linking a mixture comprising: In the block copolymer (a1), the total of 1,2-linkage units and 3,4-linkage units is 30 to 95 mol% in the binding units constituting the polymer block B1 mainly composed of a conjugated diene compound. The thermoplastic elastomer composition according to claim 6. The compounding amount of the organic peroxide (d) is such that the hydrogenated block copolymer (a), the block copolymer (a1), the softener for non-aromatic rubber (b) and the peroxide decomposable olefin resin ( 0.3 to 3 parts by mass with respect to 100 parts by mass in total of c), and the compounding amount of the crosslinking assistant (e) is 0.5 to 3 times by mass with respect to the compounding amount of the organic peroxide (d). The thermoplastic elastomer composition according to claim 6 or 7, wherein Kinematic viscosity at 40 ° C. Non-aromatic rubber softener (b) (Bv) (mm 2 / s) satisfies the following equation (1), thermoplastic according to any one of claims 6-8 Elastomer composition.
Bv (mm ² / s) ≧ 3 × 10 ⁷ / Mwa [1]
[In the above formula, Bv indicates the kinematic viscosity at 40 ° C. of the softener (b) for non-aromatic rubber, and Mwa indicates the weight average molecular weight of the hydrogenated block copolymer (a). ] Hydrogenated block copolymer (a), block copolymer (a1), softener for non-aromatic rubber (b), peroxide-decomposable olefin resin (c), organic peroxide (d) and crosslinking aid The thermoplastic elastomer composition according to any one of claims 6 to 9, wherein the mixture containing the entire amount of the agent (e) is melt-kneaded under heating and dynamically crosslinked in a single step.