JP4184206B2 - Thermoplastic elastomer composition - Google Patents

Description

  The present invention is excellent in flexibility and rubber elasticity, particularly rubber elasticity at high temperatures (for example, low compression set at a temperature of 100 to 120 ° C.), and can have a wide hardness range at high temperatures. The present invention relates to a thermoplastic elastomer composition excellent in creep resistance performance, 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 taking advantage of their excellent properties.

  Thermoplastic elastomers do not require a vulcanization process and can be molded in the same way as thermoplastic resins. In recent years, thermoplastic elastomers have been used in a wide range of fields such as automobile parts, home appliance parts, electric wire coverings, medical parts, footwear and sundries. in use. Among such thermoplastic elastomers, they are represented by polystyrene-polybutadiene-polystyrene block copolymer (SBS), polystyrene-polyisoprene-polystyrene block copolymer (SIS), and their hydrogenated products (hydrogenated products). Styrenic thermoplastic elastomers are widely used because they are inexpensive and have excellent hydrolysis resistance.

  Vinyl aromatic compound polymer represented by hydrogenated product (hydrogenated product) of polystyrene-polybutadiene-polystyrene block copolymer and hydrogenated product (hydrogenated product) of polystyrene-polyisoprene-polystyrene block copolymer The hydrogenated product (hydrogenated product) of a block copolymer containing a block and a conjugated diene compound polymer block is a heat resistance in a block copolymer containing a vinyl aromatic compound polymer block and a conjugated diene compound polymer block. Although it is an improvement of problems such as weather resistance, there is a problem that it is inferior in rubber elasticity at high temperatures and has a large compression set at high temperatures (for example, temperatures of 100 to 120 ° C.).

  In order to improve the above points, a hydrogenated product (hydrogenated product) of a block copolymer comprising such a vinyl aromatic compound polymer block-conjugated diene compound polymer block, a) a peroxide-decomposable olefin resin, and B) A method of partial crosslinking using an organic peroxide in combination with a peroxide-crosslinked olefin copolymer rubber or a peroxide-crosslinked olefin resin has been proposed (Patent Document 1 and Patent Document 2). reference).

  More specifically, Patent Document 1 discloses (i-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. (I-2) 20 to 150 parts by mass of a peroxide-crosslinked olefin copolymer rubber, (b-3) 0 to 50 parts by mass of a peroxide non-crosslinked hydrocarbon-based rubber-like substance, (b-4) non 80-300 parts by mass of a softener for aromatic rubber, (b-5) 30-400 parts by mass of a peroxide-decomposable olefin resin, and (b-6) 0-900 parts by mass of an inorganic filler, First, among the components other than (A-1), at least the total amount of (A-2) is heat-treated in the presence of an organic peroxide to dynamically crosslink, and then the dynamic cross-linked product and the remaining components are blended. Elastomeric composition Manufacturing process is disclosed. And this patent document 1 explains that the mechanical strength of the elastomeric composition is greatly reduced when the above-described multi-stage partial cross-linking and blending step is not adopted.

  Patent Document 2 discloses (ro-1) a block copolymer containing two or more 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. (Ro-2) 40 to 300 parts by weight of a softening agent for non-aromatic rubber, (ro-3) 1.0 to 100 parts by weight of peroxide-crosslinked olefin resin and / or copolymer rubber containing the same, (B-4) In the 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 component (b-3) and part of component (b-4) are crosslinked by heat treatment in the presence of an organic peroxide, and then the cross-linked product and the remainder of component (b-4) , Ma The method for producing a thermoplastic elastomer resin composition is disclosed to incorporate the remainder of the component (b -3) and the component (B -4). In this publication, a composition obtained by dynamically crosslinking in the presence of an organic peroxide and a component (B-4) to be blended later are mixed and microdispersed in the composition to obtain a thermoplastic. There is an explanation 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 above-mentioned two patent documents can dynamically crosslink each component at the final blending ratio at a time, and after dynamically crosslinking some of the components, Since it is necessary to blend the remaining components, the production process of the thermoplastic elastomer resin composition is very complicated, and particularly rubber elasticity at high temperatures (for example, compression set at a temperature of 100 to 120 ° C.) ) Is still insufficient.

  Also, 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, a) a polyolefin resin, and b) a reactive alkylphenol / formaldehyde resin In addition, a thermoplastic elastomer composition that has been dynamically vulcanized in the presence of a hydrotalcite compound as required has been proposed (see Patent Document 3).

  More specifically, Patent Document 3 includes (C-1) 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. Hydrogenating the block copolymer, 100 parts by mass of a hydrogenated block copolymer in which the hydrogenation rate of the aliphatic double bond based on the conjugated diene compound is more than 60% and less than 85%, (c-2) 20 to 200 parts by mass of a softener for 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) ) Disclosed is a dynamic vulcanized thermoplastic elastomer composition obtained by blending each component of hydrotalcite compound 0-50 parts by mass and heating and kneading the thermoplastic elastomer. Workability as, 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 thermoplastic elastomer composition of Patent Document 3, when preparing 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. Organic halides such as halides and chlorinated polyethylene or heavy metal compounds such as zinc oxide must be blended, which is not preferable from the viewpoint of safety. Further, 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 a composition having a wide hardness range cannot be produced.

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

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

  The present inventors have repeatedly studied to achieve the above object. As a result, hydrogenated block copolymer containing vinyl aromatic compound polymer block and conjugated diene compound polymer block, non-aromatic rubber softener and peroxide-decomposable olefin resin, and optionally vinyl In producing a thermoplastic elastomer composition by dynamically crosslinking 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 is produced. A block copolymer containing a polymer block and a conjugated diene compound polymer block having a specific range of iodine value (hydrogenation rate) and a specific range of molecular weight, and a block Copolymer hydrogenates, non-aromatic rubber softeners and When the blending amount of the side-decomposable olefin resin and, optionally, the block copolymer containing the vinyl aromatic compound polymer block and the conjugated diene compound polymer block is within a specific range, the multistage operation as in the prior art is performed. The present inventors have found that a dynamically crosslinked thermoplastic elastomer composition having good physical properties can be obtained in a single heating and kneading step without the need for an actual crosslinking-blending step.

In particular, the dynamically crosslinked thermoplastic elastomer composition obtained by such a one-step heat-kneading process and a molded article obtained therefrom are excellent in flexibility and rubber elasticity, particularly at high temperatures (for example, temperatures of 100 to 120 ° C.). ) With excellent rubber elasticity, low compression set even when compressed for a long time at high temperature, and can also have a wide hardness range, high temperature creep resistance, mechanical strength, oil resistance, solvent resistance The present invention has been found to be excellent in properties such as heat resistance, heat resistance (for example, the degree of coloring at 200 ° C.), weather resistance, and the like, and further, has no rough surface or bleeding out of the softening agent to the surface.
Furthermore, the present inventors preferably use a conjugated diene polymer block in which the conjugated diene polymer block is a polymer block composed of butadiene and isoprene as the hydrogenated block copolymer. It was found that the blending amount of is preferably within a specific range, and a non-aromatic rubber softener having a specific kinematic viscosity was preferably used, and the present invention was completed based on these findings.

That is, the present invention
(1) (i) hydrogenating 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, A hydrogenated block copolymer having a weight average molecular weight of 200,000 or more, wherein the iodine value of the block copolymer is in the range of 10 to 40 g / 100 g, wherein the polymer block B mainly comprising the conjugated diene compound is butadiene and isoprene. Hydrogenated block copolymer (a), a non-aromatic rubber softener (b), a peroxide-decomposable olefin resin (c), an organic peroxide (d), and a crosslinking aid Containing (e); and
(Ii) the blending amount of the non-aromatic rubber softener (b) is 50 to 250 parts by mass with respect to 100 parts by mass of the hydrogenated block copolymer (a); and
(Iii) The compounding amount of the peroxide-decomposable olefin 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 of the above.

The present invention
(2) The thermoplastic elastomer composition according to (1), wherein the polymer block B mainly comprising 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 of the hydrogenated block copolymer (a), the non-aromatic rubber softener (b) and the peroxide-decomposable olefin resin (c). Said (1) which is 0.3 to 3 parts by mass with respect to parts by mass, and the compounding amount of the crosslinking aid (e) is 0.5 to 3 times by mass with respect to the compounding amount of the organic peroxide (d). ) Or (2) thermoplastic elastomer composition; and (4) the kinematic viscosity (Bv) (mm ² / s) at 40 ° C. of the non-aromatic rubber softener (b) is represented by the following formula [1]: Satisfying 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 represents the kinematic viscosity of the non-aromatic rubber softener (b) at 40 ° C., and Mwa represents the weight average molecular weight of the hydrogenated block copolymer (a). ];
Is included as a preferred embodiment.

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

Furthermore, the present invention provides
(6) (i) hydrogenating 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, A hydrogenated block copolymer having a weight average molecular weight of 200,000 or more, wherein the iodine value of the block copolymer is in the range of 10 to 40 g / 100 g, wherein the polymer block B mainly comprising the conjugated diene compound is butadiene and isoprene. A hydrogenated block copolymer (a) which is a polymer block comprising: at least one polymer block A1 mainly comprising a vinyl aromatic compound and at least one polymer block B1 mainly comprising a conjugated diene compound Block copolymer (a1), non-aromatic rubber softener (b), peroxide-decomposable olefin resin (c) Containing 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 blending amount of the non-aromatic rubber softener (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). Is;
(Iv) The compounding amount of the peroxide-decomposable olefin resin (c) is 20 to 300 parts by mass with respect to a total of 100 parts by mass of the hydrogenated block copolymer (a) and the block copolymer (a1). is there;
A thermoplastic elastomer composition obtained by dynamically crosslinking a mixture of the above.

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

And this invention,
(10) Hydrogenated block copolymer (a), block copolymer (a1), non-aromatic rubber softener (b), peroxide-decomposable olefin resin (c), organic peroxide (d) And the thermoplastic elastomer composition according to any one of (6) to (9) above, wherein the mixture containing the total amount of the crosslinking aid (e) is melt-kneaded under heating in a single step and dynamically crosslinked Thing;

  According to the present invention, flexibility, rubber elasticity, particularly rubber elasticity under a high temperature (for example, a temperature of 100 to 120 ° C.) is excellent, compression set is small, a wide hardness region can be obtained, and resistance to high temperature is further improved. 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 characteristics, and the like can be obtained.

The present invention is described in detail below.
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. A hydrogenated block copolymer having a weight average molecular weight of 200,000 or more, wherein the iodine value of the block copolymer is in the range of 10 to 40 g / 100 g, and the conjugated diene compound is The main polymer block B is a hydrogenated block copolymer which is a polymer block composed of butadiene and isoprene .

  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, p- Examples thereof include t-butylstyrene, 2,4-dimethylstyrene, 2,4,6-trimethylstyrene, monofluorostyrene, monochlorostyrene, dichlorostyrene, vinylnaphthalene, vinylanthracene and the like. 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 unsaturated monomers other than vinyl aromatic compounds (eg 1-butene, 1-pentene, 1-hexene, butadiene, isoprene, as long as they do not interfere with the purpose and effect of the present invention. , Methyl vinyl ether, methyl methacrylate, vinyl acetate and the like, may have a small amount (preferably 10% by mass or less of polymer block A) of one or more structural units derived from the structural unit.

Further, the polymer block B that put the hydrogenated block copolymer (a) is required to be formed from both butadiene and isoprene. When the polymer block B is formed from both butadiene and isoprene, there is no stickiness of the surface of the molded product obtained from the thermoplastic elastomer composition, 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 the bleed-out of the non-aromatic rubber softener (b) can be suppressed.

The bonding form of the conjugated diene compound in the polymer block B is not particularly limited . Butadiene emissions is 1,2-bond and / or 1,4-bond, isoprene emissions are 1,2-bond, 3,4-bond and / or 1,4-bond that can take, for one of them It may be a combined form . Polymer block B is preferably the total of 1,2-bond unit and 3,4-bond unit is 5 to 70 mol%, particularly preferably 5 to 30 mol%.

  Further, when the polymer block B is formed from two or more kinds of 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 In the range of 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. Is preferable, and the range of 10 to 20 g / 100 g is more preferable. When the iodine value exceeds 40 g / 100 g, the heat resistance (for example, coloring degree at 200 ° C. and rubber elasticity at a temperature of 100 to 120 ° C.) and weather resistance of the resulting thermoplastic elastomer composition are reduced, When it is less than 10 g / 100 g, a thermoplastic elastomer composition having satisfactory performance is obtained by reducing rubber elasticity at a high temperature (for example, a temperature of 100 to 120 ° C.) of the obtained thermoplastic elastomer composition. I can't.

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 (about 0.1 g to 1 g) of the hydrogenated block copolymer (a) was accurately weighed in an Erlenmeyer flask, and 100 ml of chloroform was added and completely dissolved. (Iodine monochloride-acetic acid solution) (20 ml) is added and gently shaken, allowed to stand at room temperature for 30 minutes with the light blocked. After adding 20 ml of 0.1 g / ml potassium iodide aqueous solution and 100 ml of water to this solution, the amount of free iodine was back titrated with 0.1 N sodium thiosulfate aqueous solution, and iodine value (I: g / 100 g). At this time, the end point of the back titration with the 1N sodium thiosulfate aqueous solution is a point at which the water phase and the chloroform phase are visually observed and both are judged to be colorless. In addition, the same operation is performed without adding the hydrogenated block copolymer (a), and the titration amount (ml) of the 0.1N sodium thiosulfate aqueous solution at that time is set as a blank value.
I = (B−C) × f × 1.269 / S
I: Iodine value (g / 100g)
S: Weight (g) of weighed hydrogenated block copolymer (a)
B: Blank titration of 0.1N sodium thiosulfate aqueous solution (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 optionally be an unsaturated monomer other than the conjugated diene compound (for example, 1-butene, 1-pentene, 1-hexene, methyl vinyl ether, styrene) as long as it does not interfere with the object and effect of the present invention. , Methyl methacrylate, vinyl acetate, etc.) may be included in a small amount (preferably 10% by mass or less of polymer block B) of one or more structural units derived from.

  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 combined, The bonding mode of the polymer block is not limited, and may be any of linear, branched, radial, or a combination of two or more thereof. Among them, it is preferable that the bond form of the polymer block A and the polymer block B is linear, for example, when the polymer block A is represented by A and the polymer block B is represented by B A hydrogenated diblock copolymer of AB, a hydrogenated triblock copolymer of ABA, a hydrogenated tetrablock copolymer of ABAB, Examples thereof include hydrogenated products of pentablock copolymers of ABABABA and BABABA. Among them, the hydrogenated product of A-B-A triblock copolymer is preferably used from the viewpoints of ease 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 mechanical strength and flexibility of the thermoplastic elastomer composition. Is preferable, and it is more preferable that it exists in the range of 15-35 mass%. In addition, content of the structural unit derived from the vinyl aromatic compound in a hydrogenated block copolymer (a) can be calculated | required by a < ¹ > H-NMR spectrum.

The hydrogenated block copolymer (a) needs to have a weight average molecular weight of 200,000 or more after hydrogenation, and 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 is lowered. 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 as used in this specification is the molecular weight of polystyrene conversion calculated | required by the gel permeation chromatography (GPC) measurement.

  The hydrogenated block copolymer (a) may contain 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 end, as long as the gist of the present invention is not impaired. You may have 1 type, or 2 or more types of a functional group.

  The production method of the hydrogenated block copolymer (a) used in the present invention is not particularly limited, and can be produced by, for example, a conventionally known anionic polymerization method as follows. In other words, vinyl aromatic compounds and conjugated diene compounds are sequentially polymerized or coupled by a method such as coupling in an organic solvent inert to the polymerization reaction such as n-hexane and cyclohexane using an alkyl lithium compound as an initiator. 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 addition, 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 the conjugated diene compound As a method for controlling the iodine value of the copolymer in the range of 10 to 40 g / 100 g, a method usually performed by those skilled in the art can be employed. For example, if the reaction conditions such as reaction temperature and reaction time are adjusted appropriately, and the amount of hydrogenation catalyst used, for example, a Ziegler-based catalyst that uses a nickel compound / organoaluminum compound as the hydrogenation catalyst, On the other hand, it can be carried out by reducing the amount of the organoaluminum compound used, and further by sampling the reaction solution as appropriate to check the progress of the hydrogenation reaction and setting the 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 butyl styrene, 2,4-dimethyl styrene, 2,4,6-trimethyl styrene, monofluoro styrene, monochloro styrene, dichloro styrene, vinyl naphthalene, and vinyl anthracene. It can be formed from one or more group compounds. Among them, the polymer block A1 is preferably formed from styrene or p-methylstyrene.

  The polymer block A1 may optionally be an unsaturated monomer other than a vinyl aromatic compound (eg, 1-butene, 1-pentene, 1-hexene, butadiene, isoprene, as long as it does not interfere with the purpose and effect of the present invention. , Methyl vinyl ether, methyl methacrylate, vinyl acetate and the like, may have a small amount (preferably 10% by mass or less of the polymer block A1) of one or more structural units derived from them.

  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- Hexadiene can be used, and the polymer block B1 can be formed of 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 the heat resistance (for example, the degree of coloring at 200 ° C.) of the thermoplastic elastomer composition obtained, the polymer block B1 is made of isoprene. It is particularly preferred that it is formed.

  The bonding form of the conjugated diene compound in the polymer block B1 is not particularly limited. For example, butadiene can have 1,2-bonds and / or 1,4-bonds, isoprene can have 1,2-bonds, 3,4-bonds and / or 1,4-bonds, Any combination of these 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 of the resulting composition (for example, rubber elasticity at a temperature of 100 to 120 ° C.). It is preferable that -95 mol% and the ratio of a 1, 4- bond unit are 5-100 mol%. In the case where the polymer block B1 is formed from isoprene or is formed from both butadiene and isoprene, from the viewpoint of heat resistance of the resulting composition (for example, rubber elasticity at a temperature of 100 to 120 ° C.). , 3,4-bond units and 1,2-bond units are preferably 30 to 95 mol%, particularly preferably 45 to 95 mol%.

  Further, when the polymer block B1 is formed of two or more kinds of 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 order to control the bonding form of the polymer block B1 in the block copolymer (a1), for example, ethers such as dimethyl ether, diethyl ether, tetrahydrofuran and the like as a cocatalyst during polymerization; ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, etc. Glycol ethers; Lewis bases such as amines such as triethylamine, N, N, N ′, N′-tetramethylenediamine and N-methylmorpholine can be added.
These Lewis bases may be added singly or in combination of two or more. The addition amount of the Lewis base is determined by how much the binding form of the conjugated diene compound unit constituting the above-described polymer block B1 is controlled, and is not strictly limited, but is usually an alkyl used as an initiator. It is in the range of 0.1 to 1000 times mol per gram atom of lithium contained in the lithium compound or dilithium compound, and more preferably in the range of 1 to 100 times mol.

  The polymer block B1 may optionally be an unsaturated monomer other than the conjugated diene compound (for example, 1-butene, 1-pentene, 1-hexene, methyl vinyl ether, styrene), as long as it does not interfere with the purpose and effect of the present invention. , Methyl methacrylate, vinyl acetate, etc.) may be included in a small amount (preferably 10% by mass or less of polymer block B1).

  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 thereof. Among them, the bond 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- A pentablock copolymer of A1-B1-A1-B1 can be used. Among these, the triblock copolymer of A1-B1-A1 is preferably used from the viewpoints of ease 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 mechanical strength and flexibility of the thermoplastic elastomer composition. More preferably, it is in the range of 15 to 35% by mass. In addition, content of the structural unit derived from the vinyl aromatic compound in a block copolymer (a1) can be calculated | required by a < ¹ > H-NMR spectrum.

  Although there is no restriction | limiting in particular in the weight average molecular weight of a block copolymer (a1), The processability of the thermoplastic elastomer composition of this invention and the reduction | decrease of the defect (micro defect in a molded article) of a molded article consisting of this 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 as used in this specification is the molecular weight of polystyrene conversion calculated | required by the gel permeation chromatography (GPC) measurement.

  The block copolymer (a1) may be a functional group such as a carboxyl group, a hydroxyl group, an acid anhydride group, an amino group, or an epoxy group in the molecular chain and / or at the molecular end, as long as the gist of the present invention is not impaired. 1 type (s) or 2 or more types may be included.

  The production method of the hydrogenated block copolymer (a1) optionally used in the present invention is not particularly limited, and can be produced by, for example, a conventionally known anionic polymerization method as follows. In other words, vinyl aromatic compounds and conjugated diene compounds are sequentially polymerized or coupled by a method such as coupling in an organic solvent inert to the polymerization reaction such as n-hexane and cyclohexane using an alkyl lithium compound as an initiator. 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 mass ratio of a hydrogenated block copolymer (a) and a block copolymer (a1). It is more preferable that it is 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, the resulting thermoplastic elastomer composition becomes intensely colored at 200 ° C. In the molded product made of the thermoplastic elastomer composition produced by the method of the invention, the irregularities in the molded product (microdefects in the molded product) increase rapidly and the surface state of the molded product deteriorates. By setting the blending amount of the block copolymer (a1) to the hydrogenated block copolymer (a) in the above range, the surface state and heat resistance of the thermoplastic elastomer composition obtained and the molded product obtained therefrom (for example, The rubber elasticity under a high temperature (for example, a temperature of 100 to 120 ° C.) can be further improved without deteriorating the coloring degree at 200 ° C.

As the non-aromatic rubber softener (b) used in the present invention, any conventionally known non-aromatic rubber softener can be used, and among them, non-aromatic mineral oil or liquid Alternatively, low molecular weight synthetic softeners are suitable. The non-aromatic rubber softener (b) may be used alone or in combination of two or more.
In general, mineral oil-based rubber softeners called process oils or extender oils used to soften, increase the volume and improve processability of rubber are a combination of aromatic rings, naphthene rings and paraffin chains. 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 a naphthenic ring having 30 to 45% carbon number is naphthenic or aromatic. Those having more than 30% carbon atoms are called aromatic.
In the present invention, among the process oils described above, paraffinic process oil and naphthenic process oil can be used. Besides these, white oil, mineral oil, a 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, paraffinic process oil and / or naphthenic process oil is preferably used as the softener (b) for non-aromatic rubber.

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

Further, in the present invention, the non-aromatic rubber softener (b) is operated at 40 ° C. from the viewpoint of improving the heat resistance of the resulting thermoplastic elastomer composition, particularly maintaining the rubber elasticity at high temperatures. The viscosity (mm ² / s) preferably satisfies the following mathematical formula [1].
Bv (mm ² / s) ≧ 3 × 10 ⁷ / Mwa [1]
[In the above formula, Bv represents the kinematic viscosity of the non-aromatic rubber softener (b) at 40 ° C., and Mwa represents the weight average molecular weight of the hydrogenated block copolymer (a). ]
The kinematic viscosity (mm ² / s) at 40 ° C. of the non-aromatic rubber softener in this specification is the viscosity measured at 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). It is necessary that it is 50-250 mass parts with respect to it, Preferably it is 80-200 mass parts. 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). On the other hand, when the amount is less than 50 parts by mass, the thermoplastic elastomer composition obtained in the present invention is inferior in flexibility, and the molding processability is lowered. On the other hand, when it exceeds 250 parts by mass, the mechanical strength of the molded article made of the thermoplastic elastomer composition obtained in the present invention is insufficient, and the bleed-out of the non-aromatic rubber softener (b) occurs. .

  The peroxide-decomposable olefin resin (c) used in the present invention is an olefin resin that is thermally decomposed by heat treatment in the presence of peroxide to reduce the molecular weight and increase fluidity. As the peroxide-decomposable olefin resin (c), for example, a copolymer of polypropylene, propylene and a small amount of other α-olefin such as ethylene, 1-butene, 1-hexene, 1-octene, etc. What is generally called high melt strength polypropylene (HMS-PP) obtained by electron beam crosslinking can be used, and one or more of these can be used. Among them, a copolymer of propylene and a small amount of α-olefin and polypropylene are preferably used from the viewpoint of good rubber elasticity at a high temperature of the thermoplastic elastomer composition, and among them, called a block type or a homotype. Those 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-olefin or other monomers are roughly classified into block type and random type. The block form of each component is close to the block type, and the bond form of each component is close to random. Things are commonly referred to as random types.

  As the 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 compounding amount of the peroxide-decomposable olefin 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 that it is 20-300 mass parts, and it is more preferable that it is the range of 20-150 mass parts. When the amount of the peroxide-decomposable olefin resin (c) is less than the above-mentioned amount, the surface smoothness of the molded product obtained from the thermoplastic elastomer composition is lost, while when it exceeds 300 parts by mass, the heat obtained The rubber elasticity under high temperature (for example, a temperature of 100 to 120 ° C.) of the plastic elastomer composition is lost, and the compression set becomes large, which is not preferable.

  In this invention, an organic peroxide (d) is used with the above-mentioned component. As the organic peroxide (d), any organic peroxide having a crosslinking action under dynamic conditions may be used, and either aromatic peroxide or aliphatic peroxide can be used. 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- (Benzoylperoxy) hexane, t-butylperoxybenzoate, dicumyl peroxide, diisopropylbenzohydroperoxide, 1,3-bis- (t-butylperoxyisopropyl) benzene, benzoyl peroxide, etc. These can be used alone or in combination of two or more.

  The amount of the organic peroxide (d) used can be arbitrarily selected, but the effect of improving rubber elasticity and flow of the thermoplastic elastomer composition obtained by the method of the present invention at a high temperature (for example, a temperature at 100 to 120 ° C.). In view of the nature, it is usually preferable that the amount is 0.3 to 3 parts by mass with respect to 100 parts by mass in total of the components (a), (b) and (c), and optionally the component (a1). It is more preferable that it is 0.3-1.5 mass parts. In addition, when the below-mentioned peroxide cross-linked olefin resin (f), which can be blended as needed, is blended, the amount of the organic peroxide (d) used is the components (a), (b) and It is preferable that it is 0.3-3 mass parts with respect to a total of 100 mass parts of (c) as well as component (a1) and component (f). When the amount of the organic peroxide (d) is less than 0.3 parts by mass, the rubber elasticity at high temperature of the thermoplastic elastomer composition tends to be inferior and compression set tends to be large, whereas 3 When the content exceeds the mass part, the surface of the obtained molded product and surface roughness and unevenness (minute defects) tend to be conspicuous.

In the present invention, a crosslinking aid (e) is further used. As the crosslinking aid (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. Examples thereof include acrylic polyfunctional monomers such as dimethacrylate.
Although there is no restriction | limiting in particular in the compounding quantity of a crosslinking adjuvant (e), Generally it is especially preferable that it is the range of 0.5-3 mass parts with respect to 1 mass part of organic peroxide (d).

  In this invention, you may further mix | blend a peroxide bridge | crosslinking type olefin resin (f) as needed. The peroxide cross-linked olefin resin (f) refers to an olefin resin that is cross-linked by heat treatment in the presence of peroxide 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 these, polyethylene is preferably used from the viewpoint of exhibiting rubber elasticity at a high temperature (for example, a temperature of 100 to 120 ° C.).

  The peroxide cross-linked olefin resin (f) may be preferably blended depending on the type of the peroxide-decomposable polyolefin (c). That is, when using a polypropylene called a homotype as the peroxide-decomposable polyolefin (c), the peroxide-crosslinked olefin resin (f) can be blended arbitrarily. On the other hand, when polypropylene called block type is used as the peroxide-decomposable polyolefin (c), the peroxide-crosslinked olefin resin (f) from the viewpoint of rubber elasticity at a high temperature of the resulting thermoplastic elastomer composition. It is very preferable to blend. When a block type is used as the peroxide-decomposable polyolefin (c) and the peroxide-crosslinked olefin resin (f) is not blended, the resulting thermoplastic elastomer composition has a high temperature (eg, a temperature of 100 to 120 ° C.). The tendency to increase compression set at the bottom is inferior in rubber elasticity at high temperature, and the tendency to be inferior in oil resistance becomes remarkable.

The density of the peroxide-crosslinked olefin resin (f) that can be blended as necessary in the present invention is preferably 0.94 g / cm ³ or more, and preferably 0.95 g / cm ³ or more. More preferred. When 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 tends to be inferior at a high temperature (for example, a temperature of 100 to 120 ° C.).

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

  Although the compounding quantity of the peroxide bridge | crosslinking type olefin resin (f) which can be mix | blended as needed in this invention is not specifically limited, From a fluid viewpoint of the thermoplastic elastomer composition obtained, hydrogenated block co-polymerization It is preferable that it is 50 mass parts or less with respect to 100 mass parts of total amounts of a coalescence (a) or hydrogenated block copolymer (a), and a block copolymer (a1). When the blending amount of the peroxide cross-linked olefin resin (f) exceeds 50 parts by mass, the flexibility of the resulting thermoplastic elastomer composition is lost, and the non-aromatic rubber softener (b) bleed out. Tends to be noticeable, which is not desirable.

  In this invention, an inorganic filler can also be mix | blended as needed. By blending the inorganic filler, some physical properties such as compression set of the molded article made of the thermoplastic elastomer composition of the present invention can be improved. Further, depending on the inorganic filler used, the cost can be reduced by increasing the amount. be able to. Examples of the inorganic filler that can be used include calcium carbonate, talc, magnesium hydroxide, mica, clay, barium sulfate, natural silicic acid, synthetic silicic acid, titanium oxide, and carbon black. Or 2 or more types can be used.

  In the present invention, 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, if necessary. Pigments, dyes, brighteners and the like can be used.

The dynamically crosslinked thermoplastic elastomer composition of the present invention comprises the above components (a), (b), (c), (d) and (e), and optionally component (a1), optionally component (F) Further, if necessary, a mixture containing other components such as the above-mentioned inorganic filler is kneaded in a heated and melted state in a single step. As a result, a dynamically crosslinked thermoplastic elastomer composition having excellent properties can be produced by a very simple process.
Other methods include components (a), (b) and (c), optionally component (a1), component (f) as necessary, and inorganic filler as described above as necessary. After kneading a part of the components in the presence of components (d) and (e) in a heated and melted state, components (a), (b) and (c), and optionally component (a1), optionally Component (f), a method of adding and kneading the remaining components such as the above-mentioned inorganic filler as necessary, kneading, components (a), (b) and (c), and optionally component ( a1) If necessary, component (f) and, if necessary, all other components such as the inorganic filler described above are kneaded in a heated and melted state, and then components (d) and (e) are added and kneaded. May be employed, but from the viewpoint of ease of operation, all components How to kneading is preferably in a heated molten state collectively in one step process.
Here, “dynamic crosslinking” in the present specification means the above-described components (a), (b), (c), (d) and (e), and optionally component (a1), as necessary. It means that a mixture containing component (f) and, if necessary, other components is kneaded in a heated and melted state and crosslinked while applying a shearing stress from the outside.

  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 producing in a batch 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 1/2 or more of the total kneading time, and the second half of the kneading is the organic peroxide (d). Kneading at a temperature at which the half-life is less than half of the total kneading time is preferred from the viewpoint of improving the physical properties and molding processability of the resulting thermoplastic elastomer composition. 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) Since the cross-linking reaction proceeds before the block copolymer (a1) is finely dispersed in the composition, the resulting thermoplastic elastomer composition tends to be deteriorated in physical properties and moldability, such being undesirable. In the present specification, the first half of kneading generally refers to the time from the start of kneading to about half of the total kneading time, and the latter is called the second half of kneading.

  The batch kneading in the heat-melted state for obtaining the dynamically crosslinked thermoplastic elastomer composition of the present invention is a method conventionally used for melt-kneading the thermoplastic polymer, for example, a single screw extruder or a twin screw extruder. It can be carried out using 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 product having excellent flexibility, mechanical strength and rubber elasticity can be obtained. For example, a sheet, film, plate, tube, hose, belt, etc. Applications: Footwear for sports shoes, fashion sandals, etc .; Household appliances such as TVs, stereos, vacuum cleaners, refrigerators, etc .; Sealing packings for doors and window frames of buildings; Bumper parts, body panels, weather strips, etc. It can be effectively used in a wide range of applications such as various grips in scissors, drivers, toothbrushes, ski stocks, etc.

EXAMPLES The present invention will be specifically described below with reference to examples, 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 condition and heat resistance) of molded products obtained from the thermoplastic elastomer composition are measured by the following methods. Or evaluated.

[1] Hardness:
According to JIS K-6253, “type A” hardness was measured.

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

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

[4] Oil resistance (mass swelling rate):
A test piece having a size of length × width × thickness = 40 mm × 20 mm × 2 mm was punched out from the injection-molded sheet obtained in the following example, and 24 ° C. at 24 ° C. using No. 2 swelling oil in accordance with 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 to obtain the mass swelling rate.

[5] Surface state of molded product:
The surface of the injection-molded sheet obtained in the following examples is visually observed, and the case where there is no roughness and the surface is smooth (good), and the case where the roughness occurs is considered as poor (x) evaluated.

[6] Heat resistance of molded product:
The injection-molded sheet obtained in the following example was left in a dryer at 200 ° C., and after 1.5 hours, the coloring condition of the sheet was visually observed. Those colored in the above were evaluated as acceptable (Δ), and those colored yellow to brown were evaluated as defective (×).

The contents and abbreviations of each component used in the following examples are as follows.
<1> -1: Hydrogenated block copolymer (a)
Synthesis example 1
A pressure-resistant container purged with nitrogen and dried was charged with 50 L of cyclohexane as a solvent and 29 ml of sec-butyllithium (10% by mass, cyclohexane solution) as an initiator, heated to 50 ° C., and then added with 500 ml of styrene for 30 minutes. Polymerization was carried out, and 370 ml of styrene was further added for 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 for polymerization for 3 hours, and then 870 ml of styrene was further added for polymerization 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 this 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 progress of the reaction during the hydrogenation reaction was tracked by analysis, 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 rate) became the target value. The hydrogenated block copolymer (a) -2 and the hydrogenated block copolymer (a) -3 having the properties shown in Table 1 were obtained.

Synthesis example 4
A pressure-resistant container purged with nitrogen and dried was charged with 60 L of cyclohexane as a solvent and 19 ml of sec-butyllithium (10 mass%, cyclohexane solution) as an initiator, heated to 50 ° C., and then added with 500 ml of styrene for 30 minutes. Polymerization was performed, and 270 ml of styrene was further added for polymerization for 30 minutes. Subsequently, 4930 ml of a mixture of isoprene and butadiene (mass ratio: isoprene / butadiene = 60/40) was added to this reaction solution for polymerization for 3 hours, and then 770 ml of styrene was further added for polymerization for 30 minutes, followed by 1 ml of methanol. Was added to stop the reaction to obtain a polymerization reaction solution containing a block copolymer. Next, a Ziegler catalyst consisting of triethylaluminum and nickel 2-ethylhexanoate was added to the polymerization reaction solution, and the reaction was performed at 75 ° C. in a hydrogen pressure atmosphere of 0.8 MPa, and the progress of the reaction was analyzed. The hydrogenated block copolymer having the properties shown in Table 1 (hereinafter referred to as a hydrogenated block copolymer (hereinafter referred to as hydrogenated block copolymer (hereinafter referred to as hydrogenated block copolymer)) a) -4)).

Synthesis example 5
A pressure-resistant container purged with nitrogen and dried was charged with 60 L of cyclohexane as a solvent and 19 ml of sec-butyllithium (10 mass%, cyclohexane solution) as an initiator, heated to 50 ° C., and then added with 500 ml of styrene for 30 minutes. Polymerization was performed, and 270 ml of styrene was further added for 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 for polymerization for 3 hours, and then 770 ml of styrene was further added for polymerization for 30 minutes, followed by 1 ml of methanol. Was added to stop the reaction to obtain a polymerization reaction solution containing a block copolymer. Next, a Ziegler catalyst consisting of triethylaluminum and nickel 2-ethylhexanoate was added to the polymerization reaction solution, and the reaction was performed at 75 ° C. in a hydrogen pressure atmosphere of 0.8 MPa, and the progress of the reaction was analyzed. The hydrogenated block copolymer having the properties shown in Table 1 (hereinafter referred to as a hydrogenated block copolymer (hereinafter referred to as hydrogenated block copolymer (hereinafter referred to as hydrogenated block copolymer)) a) -5)) was obtained.

Synthesis Example 6
A pressure-resistant container purged with nitrogen and dried was charged with 60 L of cyclohexane as a solvent and 13 ml of sec-butyllithium (10 mass%, cyclohexane solution) as an initiator, heated to 50 ° C., and then added with 400 ml of styrene for 30 minutes. Polymerization was carried out, and 260 ml of styrene was further added for polymerization for 30 minutes. Subsequently, 4310 ml of a mixture of isoprene and butadiene (mass ratio: isoprene / butadiene = 50/50) was added to this reaction solution for polymerization for 3 hours, and then 660 ml of styrene was further added for polymerization for 30 minutes, followed by 0.7 ml of methanol. Was added to stop the reaction to obtain a polymerization reaction solution containing a block copolymer. Next, a Ziegler catalyst consisting of triethylaluminum and nickel 2-ethylhexanoate was added to the polymerization reaction solution, and the reaction was performed at 75 ° C. in a hydrogen pressure atmosphere of 0.8 MPa, and the progress of the reaction was analyzed. The hydrogenated block copolymer having the properties shown in Table 1 (hereinafter referred to as a hydrogenated block copolymer (hereinafter referred to as hydrogenated block copolymer (hereinafter referred to as hydrogenated block copolymer)) a) -6)) was obtained.

Synthesis example 7
A pressure-resistant container purged with nitrogen and dried was charged with 40 L of cyclohexane as a solvent and 114 ml of sec-butyllithium (10 mass%, cyclohexane solution) as an initiator, heated to 50 ° C., and then added with 800 ml of styrene for 30 minutes. Polymerization was carried out, and 370 ml of styrene was further added for 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 performed for 3 hours. Thereafter, 1170 ml of styrene was further added for polymerization for 30 minutes, and 6 ml of methanol was added. The reaction was stopped to obtain a polymerization reaction solution containing a block copolymer. Next, a Ziegler catalyst consisting of triethylaluminum and nickel 2-ethylhexanoate was added to the polymerization reaction solution, and the reaction was performed at 75 ° C. in a hydrogen pressure atmosphere of 0.8 MPa, and the progress of the reaction was analyzed. The hydrogenated block copolymer having the properties shown in Table 1 (hereinafter referred to as a hydrogenated block copolymer (hereinafter referred to as hydrogenated block copolymer (hereinafter referred to as hydrogenated block copolymer)) a) -7)) was obtained.

<1> -2: Block copolymer (a1)
Synthesis example 8
A pressure-resistant container purged with nitrogen and dried was charged with 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, heated to 50 ° C., and then added with 1100 ml of styrene. For 30 minutes, and 300 ml of styrene was further added for polymerization for 30 minutes. Subsequently, 15300 ml of isoprene was added to the reaction solution for polymerization for 3 hours, and then 1400 ml of styrene was further added for polymerization for 30 minutes. The reaction was stopped by adding 14 ml of methanol, and a block copolymer having the properties shown in Table 2 (A1) -1 was obtained.

Synthesis Example 9
A pressure-resistant container purged with nitrogen and dried was charged with 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. 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 further added for polymerization for 30 minutes. Subsequently, 17200 ml of isoprene was added to this reaction solution for polymerization for 3 hours, then 700 ml of styrene was further added for polymerization for 30 minutes, 13.0 ml of methanol was added to stop the reaction, and the block copolymer having the properties shown in Table 2 was stopped. The polymer (a1) -2 was obtained.

<2> Softener for non-aromatic rubber (b):
(B) -1: “Diana Process PW-380” manufactured by Idemitsu Kosan Co., Ltd. [paraffinic 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. [paraffinic 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 Polypro 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: “NOVATEC 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):
“Perhexa 25B-40” manufactured by Nippon Oil & Fat Co., Ltd. [2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 40% by mass containing product, support: silica]

<5> Crosslinking aid (e):
“Tyke M-60” manufactured by Nippon Kasei Co., Ltd. (triallyl isocyanurate, containing 60% by mass, support: 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: “Novatec 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 to 10 >>
(1) The above hydrogenated block copolymer (a), softener for non-aromatic rubber (b), peroxide-decomposable olefin resin (c), organic peroxide (d), crosslinking aid (e ), And if necessary, the peroxide-crosslinked olefin resin (f) is premixed in the amounts shown in Table 3, Table 4 and Table 5 below, and the mixture is mixed into a twin-screw extruder (Toshiba Machine Co., Ltd.). Manufactured by “TEM-35B”), kneaded at a screw rotation speed of 200 rpm at the temperatures shown in Table 3, Table 4 and Table 5 below, extruded into strands, cut, and dynamically crosslinked thermoplastic Elastomer composition pellets were produced.
(2) Using the pellet obtained in (1) above, using 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 of length × width × thickness = 110 mm × 110 mm × 2 mm. The molded product was measured or evaluated for hardness, tensile strength, tensile elongation, compression set, oil resistance, surface condition, and heat resistance by the methods described above. As shown in Table 3, Table 4, and Table 5 below, Met.

<< Examples 11, 12, and 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), a crosslinking aid (e), and, if necessary, a peroxide-crosslinked olefin resin (f) are mixed in advance in the amounts shown in Table 5 below, and they are mixed together into a twin-screw extruder (TOSHIBA). Of the thermoplastic elastomer composition that has been dynamically cross-linked after being extruded into strands, cut, and kneaded at a temperature shown in Table 5 below at a screw rotation speed of 200 rpm. Pellets were produced.
(2) Using the pellet obtained in (1) above, using 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 of length × width × thickness = 110 mm × 110 mm × 2 mm. With respect to this molded product, the hardness, tensile strength, tensile elongation, compression set, oil resistance, surface condition and heat resistance were measured or evaluated by the methods described above, and as shown in Table 5 below.

<< Comparative Examples 1-7 >>
(1) The above hydrogenated block copolymer (a), softener for non-aromatic rubber (b), peroxide-decomposable olefin resin (c), organic peroxide (d), crosslinking aid (e ) And peroxide cross-linked olefin resin (f) are mixed in advance in the amounts shown in Table 6 and Table 7 below, and then fed together to a twin-screw extruder (“TEM-35B” manufactured by Toshiba Machine Co., Ltd.). Then, after kneading at a temperature shown in Tables 6 and 7 at a screw rotation speed of 200 rpm, the pellets were extruded into strands and cut to produce dynamically crosslinked pellets of the thermoplastic elastomer composition.
(2) Using the pellet obtained in (1) above, using 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 of length × width × thickness = 110 mm × 110 mm × 2 mm. With respect to this molded article, the hardness, tensile strength, tensile elongation, compression set, oil resistance, surface condition and heat resistance were measured or evaluated by the methods described above, and as shown in Table 6 and Table 7 below. .

  As apparent from the results of Tables 3, 4 and 5, in Examples 1 to 13, hydrogenated block copolymers having an iodine value of 10 to 40 g / 100 g and a weight average molecular weight of 200,000 or more ( a), or a mixture of a hydrogenated block copolymer (a) and a block copolymer (a1), a non-aromatic rubber softener (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) Compounding of peroxide-decomposable olefin resin (c) in the range of 50 to 250 parts by mass of non-aromatic rubber softener (b) with respect to 100 parts by mass as a total with block copolymer (a1) 20-300 parts by weight By being in the enclosure, the molded article made of the thermoplastic elastomer composition obtained in Examples 1 to 13 is excellent in flexibility and rubber elasticity, particularly rubber elasticity at high temperature (100 to 120 ° C.). Compression set at low temperature), excellent mechanical strength and oil resistance, and excellent surface characteristics without surface roughness and bleed-out.

  Further, by comparing Example 1 with Comparative Example 1 and Example 1 with Comparative Example 2, a block copolymer formed by hydrogenation so that a specific ratio, that is, an iodine value is in the range of 10 to 40 g / 100 g. By using (a), in comparison with the block copolymer (a) which is hydrogenated out of the range, it is excellent in rubber elasticity at high temperature without deteriorating heat resistance (100 to 120 ° C. It is clear that a composition having a small compression set at a temperature of (5) can be obtained.

  And 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 condition and heat resistance of the molded product are not deteriorated. It can also be seen that the rubber elasticity at higher temperatures can be improved.

On the other hand, as is apparent from the results of Tables 6 and 7, in Comparative Example 3, water having a weight average molecular weight of less than 200,000 was used as the hydrogenated block copolymer (a) in the production of the thermoplastic elastomer composition. By using the additive block copolymer (a) -7, the molded article made of the thermoplastic elastomer composition obtained in Comparative Example 3 has a very large compression set at high temperatures. Inferior to rubber elasticity.
In Comparative Example 4, the non-aromatic rubber softener (b) was used in excess of the amount specified in the present invention, so that it was formed from the thermoplastic elastomer composition obtained in Comparative Example 4. The bleed out of the softener in the product is remarkable.
In Comparative Example 5, block-type polypropylene is used as the peroxide-decomposable olefin resin (c), but since the peroxide-crosslinked olefin resin (f) is not blended, it is obtained in Comparative Example 5. Further, a molded article made of the thermoplastic elastomer composition has a large compression set at a high temperature and is inferior in rubber elasticity at a high temperature.
In Comparative Example 6, block-type polypropylene is used as the peroxide-decomposable olefin resin (c) and polyethylene is used as the peroxide-crosslinked olefin resin (f), but the density is 0.94 g / cm. By using (f) -2 of less than ³ , the compression set at high temperature is large, the rubber elasticity at high temperature is inferior, and the oil resistance is inferior.
In Comparative Example 7, the surface roughness of the molded product is remarkable because the blending amount of the peroxide-decomposable olefin resin (c) is less than the range defined in the present invention.

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

Claims (9)

(I) hydrogenating 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; A hydrogenated block copolymer having a weight average molecular weight of 200,000 or more in which the iodine value of the coal is in the range of 10 to 40 g / 100 g, wherein the polymer block B mainly composed of the conjugated diene compound is composed of butadiene and isoprene. Hydrogenated block copolymer (a) which is a combined block , non-aromatic rubber softener (b), peroxide-decomposable olefin resin (c), organic peroxide (d) and crosslinking aid (e) Containing; and
(Ii) the blending amount of the non-aromatic rubber softener (b) is 50 to 250 parts by mass with respect to 100 parts by mass of the hydrogenated block copolymer (a); and
(Iii) The compounding amount of the peroxide-decomposable olefin 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 of the above. The amount of the organic peroxide (d) is 100 parts by mass in total of the hydrogenated block copolymer (a), the non-aromatic rubber softener (b) and the peroxide-decomposable olefin resin (c). The heat according to claim 1, wherein the amount of the crosslinking aid (e) is 0.5 to 3 parts by mass with respect to the amount of the organic peroxide (d). Plastic elastomer composition. The thermoplastic elastomer composition according to claim 1 or 2 , wherein the kinematic viscosity (Bv) (mm ² / s) of the non-aromatic rubber softener (b) at 40 ° C satisfies the following formula [1]. .
Bv (mm ² / s) ≧ 3 × 10 ⁷ / Mwa [1]
[In the above formula, Bv represents the kinematic viscosity of the non-aromatic rubber softener (b) at 40 ° C., and Mwa represents the weight average molecular weight of the hydrogenated block copolymer (a). ] Includes the total amount of hydrogenated block copolymer (a), non-aromatic rubber softener (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 3 , wherein the mixture is melt-kneaded under heating in one step and dynamically crosslinked. (I) hydrogenating 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; A hydrogenated block copolymer having a weight average molecular weight of 200,000 or more in which the iodine value of the coal is in the range of 10 to 40 g / 100 g, wherein the polymer block B mainly composed of the conjugated diene compound is composed of butadiene and isoprene. A block copolymer containing a hydrogenated block copolymer (a), which is a combined block, and 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. Polymer (a1), non-aromatic rubber softener (b), peroxide-decomposable olefin resin (c), organic Over oxide (d) and crosslinking aid contains (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 blending amount of the non-aromatic rubber softener (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). Is;
(Iv) The compounding amount of the peroxide-decomposable olefin resin (c) is 20 to 300 parts by mass with respect to a total of 100 parts by mass of the hydrogenated block copolymer (a) and the block copolymer (a1). is there;
A thermoplastic elastomer composition obtained by dynamically crosslinking a mixture of the above. Among the bond units constituting the polymer block B1 mainly composed of the conjugated diene compound in the block copolymer (a1), the total of 1,2-bond units and 3,4-bond units is 30 to 95 mol%. The thermoplastic elastomer composition according to claim 5 . The amount of the organic peroxide (d) is such that the hydrogenated block copolymer (a), the block copolymer (a1), the non-aromatic rubber softener (b) and the peroxide-decomposable olefin resin ( c) is 0.3 to 3 parts by mass with respect to 100 parts by mass in total, and the blending amount of the crosslinking aid (e) is 0.5 to 3 times by mass with respect to the blending amount of the organic peroxide (d). The thermoplastic elastomer composition according to claim 5 or 6 . Kinematic viscosity at 40 ° C. Non-aromatic rubber softener ^{(b) (Bv) (mm} 2 / s) satisfies the equation (1) below, thermoplastic according to any one of claims 5-7 Elastomer composition.
Bv (mm ² / s) ≧ 3 × 10 ⁷ / Mwa [1]
[In the above formula, Bv represents the kinematic viscosity of the non-aromatic rubber softener (b) at 40 ° C., and Mwa represents the weight average molecular weight of the hydrogenated block copolymer (a). ] Hydrogenated block copolymer (a), block copolymer (a1), non-aromatic rubber softener (b), peroxide-decomposable olefin resin (c), organic peroxide (d) and crosslinking aid The thermoplastic elastomer composition according to any one of claims 5 to 8 , wherein the mixture containing the total amount of the agent (e) is melt-kneaded under heating in one step and dynamically crosslinked.