Resin composition, stretchable film, sheet and tube

Abstract

A resin composition is provided which contains: a hydrogenated block copolymer composition containing a hydrogenated block copolymer A represented in a specific general formula (A) and a hydrogenated block copolymer B represented in a specific general formula (B); and a polyolefin-base thermoplastic resin C, wherein the weight ratio of the hydrogenated block copolymer A and the hydrogenated block copolymer B is within a specific range, and the hydrogenation ratio of olefins in the polymer components configuring the hydrogenated block copolymer composition is within a specific range.

Description

[Technical Field]

[0001] The present invention relates to a resin composition, and more particularly to a resin composition that can provide a molded article having high levels of both tensile stress and restoring force, and excellent impact resistance and thermal stability. [Background technology]

[0002] Aromatic vinyl-conjugated diene-aromatic vinyl block copolymers, such as styrene-isoprene-styrene block copolymer (SIS) and styrene-butadiene-styrene block copolymer (SBS), are thermoplastic elastomers with unique properties and are therefore used in a variety of applications. Among thermoplastic elastomers, aromatic vinyl-conjugated diene-aromatic vinyl block copolymers are particularly flexible and are therefore used as materials for films, sheets, tubes, and other products that require flexibility.

[0003] Thus, resin compositions containing aromatic vinyl-conjugated diene-aromatic vinyl block copolymers are used as materials for molded articles that require both stretchability, particularly both tensile stress and restoring force. However, there is a trade-off between tensile stress and restoring force, and increasing one of these properties tends to decrease the other. Therefore, achieving both is required. Furthermore, to improve the durability of molded articles, resin compositions that can improve the impact resistance and thermal stability of the resulting molded articles are required.

[0004] For example, Patent Document 1 discloses a hydrogenated block copolymer having, in its molecule, polymer block (C) mainly composed of a conjugated diene compound, polymer block (B) mainly composed of a conjugated diene compound, and polymer block (S) mainly composed of an aromatic vinyl compound, where polymer block (B) includes polymer blocks (B1) and (B2), the content of polymer block (C) in the hydrogenated block copolymer is 1 to 20 mass%, the content of polymer block (B) is 73 to 97 mass%, and the content of polymer block (S) is 1 to 15 mass%, the vinyl bond content of polymer block (C) before hydrogenation is 1 to 25 mol%, the vinyl bond content of polymer block (B1) is 40 to 60 mol%, and the vinyl bond content of polymer block (B2) is 60 to 100 mol%, and the hydrogenation rate is 80 mol% or more. However, the technology disclosed in Patent Document 1 was unable to achieve high levels of both tensile stress and restoring force in the resulting molded article. Furthermore, with the technology of Patent Document 1, the impact resistance of the resulting molded article is insufficient, and therefore improvement in impact resistance has been desired. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2017 / 188190 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in view of the above circumstances, and aims to provide a resin composition that can give a molded article having high levels of both tensile stress and restoring force, and excellent impact resistance and thermal stability. [Means for solving the problem]

[0007] The present inventors have conducted studies to achieve the above-mentioned object and have found that a resin composition containing a hydrogenated block copolymer composition containing a hydrogenated block copolymer A represented by a specific general formula (A) and a hydrogenated block copolymer B represented by a specific general formula (B) and a polyolefin-based thermoplastic resin C, wherein the weight ratio of hydrogenated block copolymer A to hydrogenated block copolymer B is within a specific range and the hydrogenation rate of olefin in the polymer components constituting the hydrogenated block copolymer composition is within a specific range, achieves high levels of tensile stress and restoring force and can give a molded article that is excellent in impact resistance and thermal stability, thereby completing the present invention.

[0008] That is, according to the present invention, there is provided a resin composition comprising a hydrogenated block copolymer composition having a hydrogenated block copolymer A represented by the following general formula (A) and a hydrogenated block copolymer B represented by the following general formula (B), and a polyolefin-based thermoplastic resin C, In the hydrogenated block copolymer composition, the weight ratio (A / B) of the hydrogenated block copolymer A to the hydrogenated block copolymer B is 10 / 90 to 80 / 20; The hydrogenated block copolymer composition has a resin composition in which the hydrogenation rate of olefin in the polymer components constituting the hydrogenated block copolymer composition is 10 to 100%. Ar1 a -HD a -Ar2 a (A) Ar1 b -HD b -Ar2 b (B) (In the above general formula (A) and general formula (B), Ar1 a , Ar2 a , Ar1 b , and Ar2 b is an aromatic vinyl polymer block, and HD a and HD b is a hydrogenated polymer block of a conjugated diene polymer, and Ar1 a Weight average molecular weight (Mw(Ar1 a )) for Ar2 aWeight average molecular weight (Mw(Ar2 a )) ratio (Mw(Ar2 a ) / Mw(Ar1 a )) is 2.6~66, Ar1 b Weight average molecular weight (Mw(Ar1 b )) for Ar2 b Weight average molecular weight (Mw(Ar2 b )) ratio (Mw(Ar2 b ) / Mw(Ar1 b )) is 0.95 to 1.05.

[0009] In the resin composition of the present invention, the proportion of aromatic vinyl monomer units in all repeating units of the polymer component of the hydrogenated block copolymer composition is preferably 20 to 70% by weight. In the resin composition of the present invention, the hydrogenated block copolymer composition is a and HD b However, it is preferable that the vinyl bond content of each is 1 to 80 mol %. In the resin composition of the present invention, Ar1 in the general formula (A) and the general formula (B) of the hydrogenated block copolymer composition a , Ar1 b , and Ar2 b The weight average molecular weight of each of these is in the range of 2,000 to 40,000, and HD a and HD b The weight average molecular weight of each of these is preferably in the range of 10,000 to 300,000. In the resin composition of the present invention, the ratio (C / A+B) of the content of the polyolefin-based thermoplastic resin C to the total content of the hydrogenated block copolymer A and the hydrogenated block copolymer B is preferably 10 / 90 to 90 / 10 by weight. In the resin composition of the present invention, the weight average molecular weight of all polymer components constituting the hydrogenated block copolymer composition is preferably 30,000 to 400,000. In the resin composition of the present invention, the polyolefin-based thermoplastic resin C is preferably a polypropylene-based resin.

[0010] Furthermore, according to the present invention, there is provided a stretchable film, sheet, or tube made using any of the resin compositions described above. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a resin composition that can give a molded article having high levels of both tensile stress and restoring force, and excellent impact resistance and thermal stability. DETAILED DESCRIPTION OF THE INVENTION

[0012] The resin composition of the present invention is a resin composition containing a hydrogenated block copolymer composition containing a hydrogenated block copolymer A represented by general formula (A) described below and a hydrogenated block copolymer B represented by general formula (B) described below, and a polyolefin-based thermoplastic resin C, In the hydrogenated block copolymer composition, the weight ratio (A / B) of the hydrogenated block copolymer A to the hydrogenated block copolymer B is 10 / 90 to 80 / 20; In the polymer components constituting the hydrogenated block copolymer composition, the hydrogenation rate of the olefin is 10 to 100%.

[0013] The hydrogenated block copolymer composition used in the present invention contains a hydrogenated block copolymer A represented by the following general formula (A) and a hydrogenated block copolymer B represented by the following general formula (B). Ar1 a -HD a -Ar2 a (A) Ar1 b -HD b -Ar2 b (B)

[0014] In the above general formula (A), Ar1 a , Ar2 ais an aromatic vinyl polymer block, and Ar1 a Weight average molecular weight (Mw(Ar1 a )) for Ar2 a Weight average molecular weight (Mw(Ar2 a )) ratio (Mw(Ar2 a ) / Mw(Ar1 a )) is 2.6 to 66. Also, HD a is a hydrogenated polymer block of a conjugated diene polymer.

[0015] In addition, in the above general formula (B), Ar1 b , Ar2 b is an aromatic vinyl polymer block, and Ar1 b Weight average molecular weight (Mw(Ar1 b )) for Ar2 b Weight average molecular weight (Mw(Ar2 b )) ratio (Mw(Ar2 b ) / Mw(Ar1 b )) is 0.95 to 1.05. Also, HD b is a hydrogenated polymer block of a conjugated diene polymer.

[0016] The hydrogenated block copolymer composition used in the present invention is not particularly limited, but it is preferable that the composition contains only hydrogenated block copolymer A and hydrogenated block copolymer B as polymer components.

[0017] Aromatic vinyl polymer block Ar1 of hydrogenated block copolymer A and hydrogenated block copolymer B a , Ar2 a , Ar1 b , Ar2 b is a polymer block composed of aromatic vinyl monomer units.

[0018] The aromatic vinyl monomer used to form the aromatic vinyl monomer unit is not particularly limited as long as it is an aromatic vinyl compound. Examples of aromatic vinyl compounds include styrene; alkyl-substituted styrenes such as α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, 2,4-diisopropylstyrene, 2,4-dimethylstyrene, 4-t-butylstyrene, and 5-t-butyl-2-methylstyrene; halogen-substituted styrenes such as 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene, 4-bromostyrene, 2-methyl-4,6-dichlorostyrene, and 2,4-dibromostyrene; and vinylnaphthalene. Among these, styrene is preferred. These aromatic vinyl monomers can be used alone or in combination of two or more in each aromatic vinyl polymer block. Furthermore, the same or different aromatic vinyl monomers can be used in each aromatic vinyl polymer block. The content of aromatic vinyl monomer units in each aromatic vinyl polymer block is preferably 80% by weight or more, more preferably 90% by weight or more, and particularly preferably substantially 100% by weight, based on the total weight of the aromatic vinyl polymer block.

[0019] In addition, the aromatic vinyl polymer block Ar1 constituting the hydrogenated block copolymer A and the hydrogenated block copolymer B a , Ar2 a , Ar1 b , Ar2 b may each contain a monomer unit other than the aromatic vinyl monomer unit. Examples of the monomer constituting the monomer unit other than the aromatic vinyl monomer unit include conjugated diene monomers such as 1,3-butadiene and isoprene (2-methyl-1,3-butadiene); α,β-unsaturated nitrile monomers; unsaturated carboxylic acid or acid anhydride monomers; unsaturated carboxylic acid ester monomers; and non-conjugated diene monomers.

[0020] The content of monomer units other than aromatic vinyl monomer units in each aromatic vinyl polymer block is preferably 20% by weight or less, more preferably 10% by weight or less, and particularly preferably substantially 0% by weight, based on the total weight of the aromatic vinyl polymer block.

[0021] Hydrogenated block copolymer HD of conjugated diene polymer constituting hydrogenated block copolymer A and hydrogenated block copolymer B a , HD b is a polymer block constituted by conjugated diene monomer units, and at least a portion of the conjugated diene monomer units constituting the polymer block are hydrogenated.

[0022] The conjugated diene monomer used to form the conjugated diene monomer unit is not particularly limited as long as it is a conjugated diene compound. Examples of conjugated diene compounds include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene, 1,3-pentadiene, and 1,3-hexadiene. Among these, 1,3-butadiene and / or isoprene are preferred from the viewpoint of polymerization reactivity, and isoprene is particularly preferred. These conjugated diene monomers can be used alone or in combination of two or more in each hydrogenated polymer block. Furthermore, the same conjugated diene monomer or different conjugated diene monomers can be used in each hydrogenated polymer block. The content of conjugated diene monomer units (including hydrogenated conjugated diene monomer units) in each hydrogenated polymer block is preferably 80% by weight or more, more preferably 90% by weight or more, and particularly preferably substantially 100% by weight, based on the total weight of the conjugated diene polymer block.

[0023] Hydrogenated block copolymer HD of conjugated diene polymer constituting hydrogenated block copolymer A and hydrogenated block copolymer B a , HD bmay each contain a monomer unit other than the conjugated diene monomer unit. Examples of the monomer constituting the monomer unit other than the conjugated diene monomer unit include aromatic vinyl monomers such as styrene and α-methylstyrene; α,β-unsaturated nitrile monomers; unsaturated carboxylic acid or acid anhydride monomers; unsaturated carboxylic acid ester monomers; and non-conjugated diene monomers.

[0024] The content of monomer units other than conjugated diene monomer units (including hydrogenated conjugated diene monomer units) in each hydrogenated polymer block is preferably 20% by weight or less, more preferably 10% by weight or less, and particularly preferably substantially 0% by weight, based on the total weight of the conjugated diene polymer block.

[0025] The hydrogenated block copolymer A constituting the hydrogenated block copolymer composition is Ar1 a Weight average molecular weight (Mw(Ar1 a )) for Ar2 a Weight average molecular weight (Mw(Ar2 a )) ratio (Mw(Ar2 a ) / Mw(Ar1 a )) is in the range of 2.6 to 66, and therefore, the aromatic vinyl polymer block Ar1 has a relatively small weight average molecular weight. a , hydrogenated polymer block HD of conjugated diene polymer a and an aromatic vinyl polymer block Ar2 having a relatively high weight average molecular weight a It is a hydrogenated product of an asymmetric aromatic vinyl-conjugated diene-aromatic vinyl block copolymer composed of these units in this order.

[0026] In the hydrogenated block copolymer A, Mw(Ar2 a ) / Mw(Ar1 a ) is in the range of 2.6 to 66. Mw(Ar2 a ) / Mw(Ar1 a If Mw(Ar2) is too small or too large, it becomes difficult to obtain a molded body having both a sufficient tensile stress and a sufficient restoring force. a ) / Mw(Ar1 aFrom the viewpoint of impact resistance, the molecular weight (Mw) and number average molecular weight (Mn) of the polymer or polymer block are preferably in the range of 4 to 40, more preferably 4.5 to 35. In the present invention, the weight average molecular weight (Mw) and number average molecular weight (Mn) of the polymer or polymer block are determined as polystyrene-equivalent values ​​measured by high performance liquid chromatography.

[0027] The aromatic vinyl polymer block Ar1 having a relatively small weight average molecular weight, which constitutes the hydrogenated block copolymer A, a Weight average molecular weight (Mw(Ar1 a Mw(Ar1) is preferably 2,000 to 40,000, more preferably 2,500 to 30,000, and even more preferably 3,000 to 10,000. a ) in the above range, the tensile stress and restoring force of the obtained molded body can be both achieved at a higher level.

[0028] In addition, the aromatic vinyl polymer block Ar2 having a relatively large weight average molecular weight that constitutes the hydrogenated block copolymer A a Weight average molecular weight (Mw(Ar2 a Mw(Ar2) is preferably 5,000 to 250,000, more preferably 8,000 to 120,000, and even more preferably 10,000 to 80,000. a ) in the above range, the tensile stress and restoring force of the obtained molded body can be both achieved at a higher level.

[0029] Hydrogenated block copolymer A is made up of a hydrogenated block HD of a conjugated diene polymer. aThe vinyl bond content (the proportion of 1,2-vinyl bonds and 3,4-vinyl bonds in all conjugated diene monomer units) is preferably 1 to 80 mol %, more preferably 10 to 60 mol %, and even more preferably 20 to 40 mol %. By setting the vinyl bond content within the above range, the compatibility between the hydrogenated block copolymer A and the polyolefin-based thermoplastic resin C can be increased, and the tensile stress and restoring force of the resulting molded article can be both achieved at a higher level. The vinyl bond content of the hydrogenated polymer block of the conjugated diene polymer can be adjusted by using deuterated chloroform as a solvent. 1 It can be determined by H-NMR.

[0030] Hydrogenated block copolymer A is made up of a hydrogenated block HD of a conjugated diene polymer. a Weight average molecular weight (Mw(HD a )) is preferably 10,000 to 300,000, more preferably 15,000 to 300,000, even more preferably 15,000 to 150,000, and particularly preferably 20,000 to 80,000.

[0031] The content of aromatic vinyl monomer units relative to all monomer units in the hydrogenated block copolymer A is not particularly limited, but is preferably 30 to 95% by weight, more preferably 35 to 90% by weight, even more preferably 40 to 87% by weight, and particularly preferably 43 to 85% by weight. The content of aromatic vinyl monomer units relative to all monomer units in the hydrogenated block copolymer A can be determined based on the detection intensity ratio between a differential refractometer and an ultraviolet detector in high-performance liquid chromatography measurement.

[0032] The weight average molecular weight of the hydrogenated block copolymer A as a whole is not particularly limited, but is preferably 20,000 to 500,000, more preferably 25,000 to 300,000, and even more preferably 30,000 to 150,000.

[0033] The hydrogenated block copolymer B constituting the hydrogenated block copolymer composition is a conjugated diene polymer block HD bAt each end of the b , Ar2 b The hydrogenated block copolymer B is an aromatic vinyl-conjugated diene-aromatic vinyl block copolymer composed of two aromatic vinyl polymer blocks Ar1. b , Ar2 b Weight average molecular weight (Mw(Ar1 b ), Mw(Ar2 b )) is Ar1 b Weight average molecular weight (Mw(Ar1 b )) for Ar2 b Weight average molecular weight (Mw(Ar2 b )) ratio (Mw(Ar2 b ) / Mw(Ar1 b )) is 0.95 to 1.05.

[0034] Two aromatic vinyl polymer blocks Ar1 that constitute the hydrogenated block copolymer B b , Ar2 b Weight average molecular weight (Mw(Ar1 b ), Mw(Ar2 b Mw(Ar1) is preferably 2,000 to 40,000, more preferably 2,500 to 30,000, and even more preferably 3,000 to 10,000. b ) and Mw(Ar2 b By setting the ratio of the two aromatic vinyl polymer blocks Ar1 to Ar2 in the above range, the tensile stress and the restoring force of the resulting molded article can be both achieved at a higher level. b , Ar2 b Weight average molecular weight (Mw(Ar1 b ), Mw(Ar2 b )) may be equal to or different from each other, but are preferably substantially equal to each other. For example, Ar1 b Weight average molecular weight (Mw(Ar1 b )) for Ar2 b Weight average molecular weight (Mw(Ar2 b )) ratio (Mw(Ar2 b ) / Mw(Ar1 b)) may be in the range of 0.95 to 1.05, and preferably in the range of 0.97 to 1.03.

[0035] In addition, these two aromatic vinyl polymer blocks Ar1 b , Ar2 b At least one polymer block of the b ), Mw(Ar2 b )) is an aromatic vinyl polymer block Ar1 having a relatively small weight average molecular weight, which constitutes the hydrogenated block copolymer A. a Weight average molecular weight (Mw(Ar1 a )) may be equal to or different from, but it is more preferable that they are substantially equal to. For example, Ar1 a Weight average molecular weight (Mw(Ar1 a )) for Ar1 b Weight average molecular weight (Mw(Ar1 b )) ratio (Mw(Ar1 b ) / Mw(Ar1 a )) may be in the range of 0.9 to 2.2, and Ar1 a Weight average molecular weight (Mw(Ar1 a )) for Ar2 b Weight average molecular weight (Mw(Ar2 b )) ratio (Mw(Ar2 b ) / Mw(Ar1 a )) may be in the range of 0.9 to 2.2. a Weight average molecular weight (Mw(Ar1 a )) for Ar1 b Weight average molecular weight (Mw(Ar1 b )) ratio (Mw(Ar1 b ) / Mw(Ar1 a )) is in the range of 0.95 to 1.05, or Ar1 a Weight average molecular weight (Mw(Ar1 a )) for Ar2 b Weight average molecular weight (Mw(Ar2 b )) ratio (Mw(Ar2 b ) / Mw(Ar1 a)) is preferably in the range of 0.95 to 1.05.

[0036] Hydrogenated block copolymer B is made up of conjugated diene polymer block HD. b The vinyl bond content (the proportion of 1,2-vinyl bonds and 3,4-vinyl bonds in all conjugated diene monomer units) is preferably 1 to 80 mol %, more preferably 10 to 60 mol %, and even more preferably 20 to 40 mol %. By setting the vinyl bond content within the above range, the compatibility between the hydrogenated block copolymer B and the polyolefin-based thermoplastic resin C can be increased, and the tensile stress and restoring force of the resulting molded article can be both achieved at a higher level. The vinyl bond content of the hydrogenated polymer block of the conjugated diene polymer can be adjusted by using deuterated chloroform as a solvent. 1 The hydrogenated polymer block HD of the conjugated diene polymer constituting the hydrogenated block copolymer B can be determined by H-NMR. b The vinyl bond content of the hydrogenated polymer block HD of the conjugated diene polymer constituting the hydrogenated block copolymer A is a For example, the vinyl bond content of the hydrogenated polymer block HD of the conjugated diene polymer constituting the hydrogenated block copolymer A is preferably substantially equal to that of the hydrogenated polymer block HD of the conjugated diene polymer. a The hydrogenated polymer block HD of the conjugated diene polymer constituting the hydrogenated block copolymer B with respect to the vinyl bond content of b It is preferable that the ratio of the vinyl bond contents is in the range of 0.95 to 1.05.

[0037] In producing the hydrogenated block copolymer composition used in the present invention, for example, when a production method using a coupling agent is employed, such as a production method for a hydrogenated block copolymer composition having steps (1a) to (6a) described below, the hydrogenated polymer block HD of the conjugated diene polymer constituting the hydrogenated block copolymer B may be used. b However, the hydrogenated block copolymer B may contain a residue of a coupling agent. Specifically, the hydrogenated block copolymer B may be a compound represented by the following formula: Ar1 b -(HDb’ -X-HD b’ ’ )-Ar2 b That is, as shown in the above formula, the hydrogenated polymer block HD of the conjugated diene polymer b However, HD is reacted with the coupling agent residue X. b’ , HD b’ ’ Examples of the residue X of the coupling agent include residues of bifunctional coupling agents exemplified in the method for producing a hydrogenated block copolymer composition having steps (1a) to (6a) described below.

[0038] Hydrogenated block copolymer B is made up of conjugated diene polymer block HD. b Weight average molecular weight (Mw(HD b )) is preferably 10,000 to 300,000, more preferably 15,000 to 300,000, even more preferably 15,000 to 150,000, and particularly preferably 20,000 to 80,000.

[0039] The content of aromatic vinyl monomer units relative to the total monomer units of hydrogenated block copolymer B is not particularly limited, but is preferably 10 to 35% by weight, more preferably 12 to 32% by weight, and even more preferably 15 to 30% by weight. The content of aromatic vinyl monomer units relative to the total monomer units of hydrogenated block copolymer A can be determined based on the detection intensity ratio between a differential refractometer and an ultraviolet detector in high performance liquid chromatography measurement.

[0040] The weight average molecular weight of the hydrogenated block copolymer B as a whole is not particularly limited, but is preferably 20,000 to 200,000, more preferably 25,000 to 150,000, and even more preferably 30,000 to 70,000.

[0041] The molecular weight distributions of the hydrogenated block copolymer A and hydrogenated block copolymer B constituting the hydrogenated block copolymer composition used in the present invention, and of each polymer block constituting these, expressed as the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) [(Mw) / (Mn)], are not particularly limited, but are each preferably 1.1 or less, more preferably 1.05 or less.

[0042] The weight ratio (A / B) of hydrogenated block copolymer A to hydrogenated block copolymer B contained in the hydrogenated block copolymer composition used in the present invention is 10 / 90 to 80 / 20. If the weight ratio (A / B) is too small or too large, it becomes difficult to achieve both a high elastic modulus and a low permanent elongation. The weight ratio (A / B) is preferably 12 / 88 to 60 / 40, more preferably 15 / 85 to 50 / 50. By containing hydrogenated block copolymer A and hydrogenated block copolymer B in such a ratio, the obtained molded article can achieve both a high level of tensile stress and restoring force. The weight ratio (A / B) of hydrogenated block copolymer A to hydrogenated block copolymer B can be determined from the area ratio of the peaks corresponding to each block copolymer in a chart obtained by high-performance liquid chromatography.

[0043] The hydrogenated block copolymer composition used in the present invention has an olefin hydrogenation rate in the range of 10 to 100% in the polymer components constituting the hydrogenated block copolymer composition. Here, the olefin hydrogenation rate refers to the olefin hydrogenation rate in all polymer components constituting the hydrogenated block copolymer composition, specifically, the proportion (mol %) of hydrogenated double bonds among all non-aromatic carbon-carbon double bonds contained in the polymer components before hydrogenation. As a result of extensive investigations, the present inventors have found that a resin composition containing a hydrogenated block copolymer A represented by the above general formula (A) and a hydrogenated block copolymer B represented by the above general formula (B) in specific weight ratios, in which the olefin hydrogenation rate in the hydrogenated block copolymer composition is within the above range, can achieve excellent thermal stability while simultaneously achieving a high elastic modulus and a low permanent elongation at high levels, and can also achieve excellent impact resistance.

[0044] The hydrogenation rate of the olefin in the polymer components constituting the hydrogenated block copolymer composition used in the present invention is in the range of 10 to 100%. If the hydrogenation rate of the olefin is too low, the resin composition will have insufficient thermal stability. The hydrogenation rate of the olefin is preferably 30 to 100%, more preferably 70 to 100%, and even more preferably 90 to 100%. By keeping the hydrogenation rate of the olefin within the above range, the thermal stability of the obtained molded article can be further improved while maintaining excellent tensile stress, resilience, and impact resistance. The hydrogenation rate of the olefin can be adjusted by using deuterated chloroform as a solvent. 1 It can be determined by H-NMR spectroscopy.

[0045] The hydrogenated block copolymer composition used in the present invention may have an olefin hydrogenation rate within the above range. The iodine value of the polymer components constituting the hydrogenated block copolymer composition is preferably within the range of 0 to 300 gI2 / 100 g, more preferably within the range of 0 to 150 gI2 / 100 g, even more preferably within the range of 0 to 125 gI2 / 100 g, even more preferably within the range of 0 to 100 gI2 / 100 g, particularly preferably within the range of 0 to 75 gI2 / 100 g, and most preferably within the range of 0 to 30 gI2 / 100 g. By having an iodine value within the above range, the thermal stability of the resulting molded article can be further improved while maintaining its excellent tensile stress, resilience, and impact resistance. The iodine value can be determined in accordance with JIS K0070.

[0046] In the hydrogenated block copolymer composition used in the present invention, the proportion of aromatic vinyl monomer units relative to the total polymer components in the hydrogenated block copolymer composition (total monomer units constituting the polymer components) (hereinafter sometimes referred to as the "total aromatic vinyl monomer unit content") is preferably 20 to 70% by weight, more preferably 25 to 60% by weight, and even more preferably 30 to 50% by weight. By setting the total aromatic vinyl monomer unit content within the above range, it is possible to achieve a high level of both tensile stress and restoring force in the resulting molded article. The total aromatic vinyl monomer unit content can be easily adjusted by taking into account the aromatic vinyl monomer unit contents of hydrogenated block copolymer A, hydrogenated block copolymer B, and other polymer components constituting the hydrogenated block copolymer composition, and adjusting the blending amounts of these components. The total aromatic vinyl monomer unit content can be easily adjusted by taking into account the aromatic vinyl monomer unit contents of hydrogenated block copolymer A, hydrogenated block copolymer B, and other polymer components constituting the hydrogenated block copolymer composition, and adjusting the blending amounts of these components. 1 It can be determined by H-NMR measurement.

[0047] In addition, when all polymer components constituting the hydrogenated block copolymer composition are composed only of aromatic vinyl monomer units and conjugated diene monomer units, the polymer components in the hydrogenated block copolymer composition can be decomposed by ozonolysis and then reduced with lithium aluminum hydride according to the method described in Rubber Chem. Technol., 45, 1295 (1972). This decomposes the conjugated diene monomer unit portions (including hydrogenated portions), allowing only the aromatic vinyl monomer unit portions to be isolated, thereby easily measuring the total aromatic vinyl monomer unit content. The aromatic vinyl monomer unit content and conjugated diene monomer unit content in each block copolymer can be determined by a similar method.

[0048] The weight average molecular weight of all the polymer components constituting the hydrogenated block copolymer composition used in the present invention is not particularly limited, but is preferably 30,000 to 400,000, more preferably 35,000 to 100,000, and even more preferably 40,000 to 80,000.

[0049] Furthermore, the molecular weight distribution, which is expressed as the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of all the polymer components constituting the hydrogenated block copolymer composition used in the present invention, is not particularly limited, but is preferably 1.01 to 10, more preferably 1.02 to 5, and even more preferably 1.03 to 3.

[0050] The melt index of the hydrogenated block copolymer composition used in the present invention is preferably 0.1 to 150 g / 10 min, more preferably 3 to 100 g / 10 min, and even more preferably 5 to 50 g / 10 min. The melt index of the hydrogenated block copolymer composition can be measured in accordance with ASTM D-1238 (G condition, 200°C, 5 kg).

[0051] The method for producing the hydrogenated block copolymer composition used in the present invention is not particularly limited, and can be produced, for example, by separately producing hydrogenated block copolymer A and hydrogenated block copolymer B according to conventional block copolymer production methods and hydrogenation methods, blending other polymer components and various additives as necessary, and then mixing them according to a conventional method such as kneading, solution mixing, etc. On the other hand, in the present invention, the production method described below is preferred from the viewpoint of being able to produce the hydrogenated block copolymer composition with high productivity.

[0052] That is, the method for producing the hydrogenated block copolymer composition used in the present invention is preferably a production method comprising the following steps (1) to (7). (1): A step of polymerizing an aromatic vinyl monomer in a solvent using a polymerization initiator to obtain a solution containing an aromatic vinyl polymer having an active terminal. (2): A step of adding a conjugated diene monomer to the solution containing the aromatic vinyl polymer having active terminals obtained in the step (1) above, and polymerizing the conjugated diene monomer to obtain a solution containing an aromatic vinyl-conjugated diene block copolymer having active terminals. (3): A step of adding an aromatic vinyl monomer to the solution containing the aromatic vinyl-conjugated diene block copolymer having an active terminal obtained in the step (2) above, and polymerizing the aromatic vinyl monomer to obtain a solution containing the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer having an active terminal. (4): A step of adding a polymerization terminator to the solution containing the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer having active ends obtained in the step (3) in an amount of less than 1 molar equivalent relative to the active ends to deactivate a portion of the active ends of the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer having active ends, thereby obtaining a solution containing block copolymer B'. (5): A step of adding an aromatic vinyl monomer to the solution containing the block copolymer B' obtained in the step (4) above, and polymerizing the aromatic vinyl monomer to obtain a solution containing the block copolymer B' and the block copolymer A'. (6): A step of subjecting the solution containing block copolymer B' and block copolymer A' obtained in the step (5) to a hydrogenation reaction to obtain a solution containing hydrogenated block copolymer B and hydrogenated block copolymer A. (7): A step of recovering a hydrogenated block copolymer composition from the solution containing the hydrogenated block copolymer B and the hydrogenated block copolymer A obtained in the step (6) above.

[0053] <Process (1)> In the method for producing this hydrogenated block copolymer composition, first, in step (1), an aromatic vinyl monomer is polymerized in a solvent using a polymerization initiator to obtain a solution containing an aromatic vinyl polymer having an active end.

[0054] The polymerization initiator may be any polymerization initiator known to have anionic polymerization activity for aromatic vinyl monomers and conjugated diene monomers, such as organic alkali metal compounds, organic alkaline earth metal compounds, and organic lanthanoid series rare earth metal compounds.

[0055] As the organic alkali metal compound, an organic lithium compound having one or more lithium atoms in the molecule is particularly preferably used. Specific examples of the organic alkali metal compound include organic monolithium compounds such as ethyllithium, n-propyllithium, isopropyllithium, n-butyllithium, sec-butyllithium, t-butyllithium, hexyllithium, phenyllithium, stilbenelithium, dialkylaminolithium, diphenylaminolithium, and ditrimethylsilylaminolithium; organic dilithium compounds such as methylenedilithium, tetramethylenedilithium, hexamethylenedilithium, isoprenyldilithium, and 1,4-dilithio-ethylcyclohexane; and organic trilithium compounds such as 1,3,5-trilithiobenzene. Among these, organic monolithium compounds are particularly preferably used.

[0056] Examples of organic alkaline earth metal compounds include n-butyl magnesium bromide, n-hexyl magnesium bromide, ethoxy calcium, calcium stearate, t-butoxy strontium, ethoxy barium, isopropoxy barium, ethylmercapto barium, t-butoxy barium, phenoxy barium, diethylamino barium, barium stearate, and ethyl barium.

[0057] In addition to the above, catalysts that form a homogeneous system in an organic solvent and have living polymerizability, such as a composite catalyst comprising a lanthanoid series rare earth metal compound containing neodymium, samarium, gadolinium, etc. / alkylaluminum / alkylaluminum halide / alkylaluminum hydride, and a metallocene catalyst containing titanium, vanadium, samarium, gadolinium, etc., can also be used.

[0058] The polymerization initiators may be used singly or in combination of two or more. The amount of the polymerization initiator used is not particularly limited and may be determined depending on the molecular weight of the target block copolymer, but is preferably 0.01 to 20 mmol, more preferably 0.05 to 15 mmol, and even more preferably 0.1 to 10 mmol per 100 g of the total monomers used in the polymerization.

[0059] The solvent used in the polymerization is not particularly limited as long as it is inert to the polymerization initiator, but examples thereof include chain hydrocarbon solvents, cyclic hydrocarbon solvents, and mixtures thereof. Examples of chain hydrocarbon solvents include chain alkanes and alkenes having 4 to 6 carbon atoms, such as n-butane, isobutane, 1-butene, isobutylene, trans-2-butene, cis-2-butene, 1-pentene, trans-2-pentene, cis-2-pentene, n-pentane, isopentane, neo-pentane, and n-hexane. Examples of cyclic hydrocarbon solvents include aromatic compounds such as benzene, toluene, and xylene; alicyclic hydrocarbon compounds such as cyclopentane and cyclohexane; and the like. These solvents may be used alone or in combination.

[0060] The amount of solvent used is not particularly limited, but is preferably an amount such that the concentration of all block copolymers in the solution after the polymerization reaction is 5 to 60% by weight, more preferably 10 to 55% by weight, and even more preferably 20 to 50% by weight.

[0061] Furthermore, when producing a hydrogenated block copolymer composition, a Lewis base compound may be added to the reaction system to control the structure of each polymer block of each block copolymer. Examples of Lewis base compounds include ethers such as tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, and diethylene glycol dibutyl ether; tertiary amines such as tetramethylethylenediamine, trimethylamine, triethylamine, pyridine, and quinuclidine; alkali metal alkoxides such as potassium t-amyl oxide and potassium t-butyl oxide; and phosphines such as triphenylphosphine. These Lewis base compounds may be used alone or in combination.

[0062] When producing a hydrogenated block copolymer composition, the timing of adding the Lewis base compound is not particularly limited and may be appropriately determined depending on the structure of each target block copolymer. For example, the Lewis base compound may be added in advance before the start of polymerization, or after some of the polymer blocks have been polymerized. Furthermore, the Lewis base compound may be added in advance before the start of polymerization, and then additionally added after some of the polymer blocks have been polymerized.

[0063] The polymerization reaction temperature is preferably 10 to 150°C, more preferably 30 to 130°C, and even more preferably 40 to 90°C, and the polymerization time is preferably within 48 hours, more preferably 0.5 to 10 hours. The polymerization pressure is not particularly limited, as long as it is within a pressure range sufficient to maintain the monomers and solvent in a liquid phase at the polymerization temperature.

[0064] Under the above conditions, an aromatic vinyl monomer is polymerized in a solvent using a polymerization initiator to obtain a solution containing an aromatic vinyl polymer having an active end. The aromatic vinyl polymer having an active end obtained in step (1) is a hydrogenated block copolymer composition containing an aromatic vinyl polymer block Ar1 having a relatively small weight average molecular weight of the hydrogenated block copolymer A. a and aromatic vinyl polymer block Ar1 of hydrogenated block copolymer B b , Ar2 b Either one of (i.e., Ar1 b or Ar2 b Therefore, the polymerization conditions in step (1), including the amount of the aromatic vinyl monomer, may be determined depending on the target weight-average molecular weight of the polymer block.

[0065] <Process (2)> Next, in step (2), a conjugated diene monomer is added to the solution containing the aromatic vinyl polymer having active ends obtained in step (1), and the conjugated diene monomer is polymerized to obtain a solution containing an aromatic vinyl-conjugated diene block copolymer having active ends.

[0066] According to step (2), by adding a conjugated diene monomer to the solution containing the aromatic vinyl polymer having active ends obtained in step (1), a conjugated diene polymer chain is formed starting from the active ends, thereby obtaining a solution containing an aromatic vinyl-conjugated diene block copolymer having active ends.

[0067] The conjugated diene polymer chain formed in step (2) (the conjugated diene block constituting the aromatic vinyl-conjugated diene block copolymer having an active end obtained in step (2)) is a hydrogenated polymer block HD of the conjugated diene polymer of the hydrogenated block copolymer A. a and hydrogenated block copolymer B of conjugated diene polymer block HD bTherefore, the polymerization conditions in step (2), including the amount of the conjugated diene polymer, may be determined depending on the target weight average molecular weight of these polymer blocks, etc. (for example, the polymerization conditions may be determined within the ranges explained in step (1) above).

[0068] <Process (3)> Next, in step (3), an aromatic vinyl monomer is added to the solution containing the aromatic vinyl-conjugated diene block copolymer having active ends obtained in step (2), and the aromatic vinyl monomer is polymerized to obtain a solution containing the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer having active ends.

[0069] According to step (3), by adding an aromatic vinyl monomer to the solution containing the aromatic vinyl-conjugated diene block copolymer having an active end obtained in step (2), an aromatic vinyl polymer chain is formed starting from the active end, thereby obtaining a solution containing the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer having an active end.

[0070] The aromatic vinyl polymer chain formed in step (3) (the aromatic vinyl block constituting the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer having an active end obtained in step (3)) is the aromatic vinyl polymer block Ar1 of the hydrogenated block copolymer B. b , Ar2 b One of the two (i.e., Ar1 b or Ar2 b Among these, a block different from the block formed in step (1) is used, for example, Ar1 b When Ar2 is formed, bTherefore, the polymerization conditions in step (3), including the amount of aromatic vinyl monomer, may be determined depending on the target weight-average molecular weight of the polymer block, etc. (for example, the polymerization conditions may be determined within the ranges explained in step (1) above).

[0071] <Process (4)> Next, in step (4), a polymerization terminator is added to the solution containing the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer having active ends obtained in step (3) in an amount of less than 1 molar equivalent relative to the active ends, thereby deactivating a portion of the active ends of the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer having active ends, thereby obtaining a solution containing block copolymer B'.

[0072] The block copolymer B′ obtained in the step (4) is the block copolymer before hydrogenation for obtaining the hydrogenated block copolymer B.

[0073] The polymerization terminator can react with an active terminal to deactivate the active terminal, and after reacting with one active terminal, it does not react with another active terminal. It is not particularly limited, but a compound containing no halogen atoms is preferred. Among these, a polymerization terminator that generates a metal alkoxide, a metal aryloxide, or a metal hydroxide when reacting with an active terminal is particularly preferred. Specific examples of the polymerization terminator include water; monohydric alcohols such as methanol and ethanol; and monohydric phenols such as phenol and cresol.

[0074] The amount of the polymerization terminator used may be determined depending on the ratio of hydrogenated block copolymer A and hydrogenated block copolymer B that constitute the hydrogenated block copolymer composition, and is not particularly limited as long as it is an amount that is less than 1 molar equivalent relative to the active terminals of the polymer. However, the amount of the polymerization terminator used is preferably in the range of 0.18 to 0.91 molar equivalents, and more preferably in the range of 0.35 to 0.80 molar equivalents, relative to the active terminals of the polymer.

[0075] As described above, according to step (4), by adding a polymerization terminator to a solution containing an aromatic vinyl-conjugated diene-aromatic vinyl block copolymer having active ends in an amount less than 1 molar equivalent relative to the active ends, the active ends of some of the copolymers among the aromatic vinyl-conjugated diene-aromatic vinyl block copolymers having active ends are deactivated, and these copolymers with deactivated active ends become block copolymer B' before hydrogenation for constituting hydrogenated block copolymer B. The remaining portion of the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer having active ends that did not react with the polymerization terminator remains unreacted in the solution while maintaining its active ends.

[0076] <Process (5)> Next, in step (5), an aromatic vinyl monomer is added to the solution containing the block copolymer B' obtained in step (4) above, and the aromatic vinyl monomer is polymerized to obtain a solution containing the block copolymer B' and the block copolymer A'.

[0077] According to step (5), when an aromatic vinyl monomer is added to the solution obtained in step (4), the aromatic vinyl monomer is further polymerized from the aromatic vinyl polymer chain on the side having the active end of the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer having an active end that has remained unreacted with the polymerization terminator, thereby extending the aromatic vinyl polymer chain and producing block copolymer A'. Note that block copolymer A' is an aromatic vinyl-conjugated diene-aromatic vinyl block copolymer obtained by extending the aromatic vinyl polymer chain, and serves as the block copolymer before hydrogenation to obtain hydrogenated block copolymer A.

[0078] In this case, in the step (5), the aromatic vinyl polymer chain extended is an aromatic vinyl polymer block Ar2 having a relatively large weight average molecular weight of the hydrogenated block copolymer A constituting the hydrogenated block copolymer composition. aTherefore, the polymerization conditions in step (5), including the amount of the aromatic vinyl monomer, are determined so as to form such an aromatic vinyl polymer block Ar2. a The polymerization conditions may be determined depending on the target weight average molecular weight, etc. (for example, the polymerization conditions may be determined within the ranges explained in the above step (1)).

[0079] <Process (6)> Next, in step (6), the solution containing block copolymer B' and block copolymer A' obtained in step (5) is subjected to a hydrogenation reaction to obtain a solution containing hydrogenated block copolymer B and hydrogenated block copolymer A.

[0080] The method for hydrogenating the solution containing the block copolymer B' and the block copolymer A' is not particularly limited, but examples thereof include a method in which the solution containing the block copolymer B' and the block copolymer A' is brought into contact with hydrogen in the presence of a hydrogenation catalyst.

[0081] The hydrogenation catalyst is not particularly limited, but examples thereof include supported heterogeneous catalysts in which a metal such as Ni, Pt, Pd, or Ru is supported on a carrier such as carbon, silica, alumina, or diatomaceous earth; Ziegler-type catalysts that use an organic salt or acetylacetone salt of Ni, Co, Fe, Cr, or the like and a reducing agent such as organoaluminum; organic complex catalysts such as organometallic compounds of Ru, Rh, etc.; and homogeneous catalysts that use a titanocene compound and a reducing agent such as organolithium, organoaluminum, or organomagnesium; among these, Ziegler-type catalysts are preferred.

[0082] The hydrogenation reaction can be carried out according to the methods disclosed in, for example, Japanese Patent Publication Nos. 42-8704, 43-6636, Japanese Patent Laid-Open Nos. 59-133203, and 60-220147.

[0083] The hydrogenation reaction conditions may be selected depending on the hydrogenation rate of the olefin in the polymer components constituting the hydrogenated block copolymer composition, but the hydrogenation reaction temperature is preferably 0 to 200°C, more preferably 30 to 150°C. The hydrogen pressure used in the hydrogenation reaction is preferably 0.1 to 15 MPa, more preferably 0.2 to 10 MPa, and even more preferably 0.3 to 5 MPa, and the hydrogenation reaction time is preferably 3 minutes to 10 hours, more preferably 10 minutes to 5 hours. The hydrogenation reaction may be carried out by a batch process, a continuous process, or a combination thereof.

[0084] <Process (7)> Next, in step (7), the target hydrogenated block copolymer composition is recovered from the solution containing hydrogenated block copolymer B and hydrogenated block copolymer A obtained in step (6) above.

[0085] The recovery method may be a conventional method and is not particularly limited. For example, after the reaction is completed, if necessary, a polymerization terminator is added to deactivate the active ends of the polymer having active ends, and if necessary, an additive such as an antioxidant is added, and then the solution is subjected to a known solvent method such as direct drying or steam stripping, thereby recovering the target hydrogenated block copolymer composition. In this case, the polymerization terminator may be any of those described above.

[0086] When the hydrogenated block copolymer composition is recovered as a slurry by steam stripping or the like, it is preferable to dehydrate it using an arbitrary dehydrator such as an extruder-type squeezer to recover the hydrogenated block copolymer composition in the form of crumbs, and then dry the obtained crumbs using an arbitrary dryer such as a band dryer or an expansion extrusion dryer. The hydrogenated block copolymer composition thus obtained may be processed into pellets or the like according to a conventional method before use.

[0087] The solid (pellet, crumb, etc.) hydrogenated block copolymer composition thus obtained is preferably used after reducing the water content in the solid hydrogenated block copolymer composition using a dryer such as a hopper dryer, a hot air circulation tray dryer, a tray vacuum dryer, an agitation vacuum dryer, etc. The drying conditions are not particularly limited as long as the target water content can be achieved, and may be set depending on the amount of water to be reduced and the type of dryer, etc., but are usually set at a drying temperature of 40 to 90°C for a drying time of 1 to 24 hours.

[0088] According to the above-described method for producing a hydrogenated block copolymer composition, hydrogenated block copolymer A and hydrogenated block copolymer B can be continuously produced in the same reaction vessel, and therefore the target hydrogenated block copolymer composition can be produced with superior productivity compared to the case where each hydrogenated block copolymer is produced separately and then mixed.

[0089] In addition to the above-described preferred production method (a production method comprising steps (1) to (7)), a production method for a hydrogenated block copolymer composition comprising the following steps (1a) to (6a) is also preferably used when producing the hydrogenated block copolymer composition of the present invention. (1a): A step of polymerizing an aromatic vinyl monomer in a solvent using a polymerization initiator to obtain a solution containing an aromatic vinyl polymer having an active terminal. (2a): A step of adding a conjugated diene monomer to the solution containing the aromatic vinyl polymer having active terminals obtained in the above step (1a) and polymerizing the conjugated diene monomer to obtain a solution containing an aromatic vinyl-conjugated diene block copolymer having active terminals. (3a): A step of adding a bifunctional coupling agent to a solution containing the aromatic vinyl-conjugated diene block copolymer having active ends obtained in the step (2a) above, in an amount such that the total amount of functional groups relative to the active ends is less than 1 molar equivalent, thereby coupling a portion of the aromatic vinyl-conjugated diene block copolymer having active ends, thereby obtaining a solution containing block copolymer B'. (4a): A step of adding an aromatic vinyl monomer to the solution containing the block copolymer B' obtained in the step (3a) above, and polymerizing the aromatic vinyl monomer to obtain a solution containing the block copolymer B' and the block copolymer A'. (5a): A step of subjecting the solution containing block copolymer B' and block copolymer A' obtained in the step (4a) above to a hydrogenation reaction to obtain a solution containing hydrogenated block copolymer B and hydrogenated block copolymer A. (6a): A step of recovering a hydrogenated block copolymer composition from the solution containing the hydrogenated block copolymer B and the hydrogenated block copolymer A obtained in the step (5a) above.

[0090] <Process (1a), Process (2a)> Steps (1a) and (2a) are similar to the above-mentioned steps (1) and (2), and similar conditions can be employed.

[0091] <Process (3a)> In step (3a), a bifunctional coupling agent is added to the solution containing the aromatic vinyl-conjugated diene block copolymer having active ends obtained in step (2a) in an amount such that the total amount of functional groups relative to the active ends is less than 1 molar equivalent, thereby coupling a portion of the aromatic vinyl-conjugated diene block copolymer having active ends to obtain a solution containing block copolymer B'.

[0092] The block copolymer B′ obtained in the step (3a) is the block copolymer before hydrogenation to obtain the hydrogenated block copolymer B.

[0093] The bifunctional coupling agent is not particularly limited as long as it has two functional groups that react with the active terminal, and examples thereof include bifunctional halogenated silanes such as dichlorosilane, monomethyldichlorosilane, and dimethyldichlorosilane; bifunctional halogenated alkanes such as dichloroethane, dibromoethane, methylene chloride, and dibromomethane; and bifunctional tin halides such as dichlorotin, monomethyldichlorotin, dimethyldichlorotin, monoethyldichlorotin, diethyldichlorotin, monobutyldichlorotin, and dibutyldichlorotin.

[0094] The amount of the bifunctional coupling agent used may be determined depending on the ratio of hydrogenated block copolymer A and hydrogenated block copolymer B that constitute the hydrogenated block copolymer composition.

[0095] As described above, according to step (3a), by adding a bifunctional coupling agent to a solution containing an aromatic vinyl-conjugated diene block copolymer having active ends in an amount such that the total amount of functional groups relative to the active ends is less than 1 molar equivalent, a portion of the aromatic vinyl-conjugated diene block copolymer having active ends is coupled to form block copolymer B' before hydrogenation, which is used to form hydrogenated block copolymer B. The remaining portion of the aromatic vinyl-conjugated diene block copolymer having active ends that did not react with the bifunctional coupling agent remains unreacted in the solution, maintaining its active ends.

[0096] <Process (4a)> Next, in step (4a), an aromatic vinyl monomer is added to the solution containing block copolymer B' obtained in step (3a) above, and the aromatic vinyl monomer is polymerized to obtain a solution containing block copolymer B' and block copolymer A'.

[0097] According to step (4a), when an aromatic vinyl monomer is added to the solution obtained in step (3a), the aromatic vinyl monomer is polymerized from the active end of the aromatic vinyl-conjugated diene block copolymer having an active end that remains unreacted with the bifunctional coupling agent, thereby forming an aromatic vinyl polymer chain, thereby obtaining block copolymer A'. Note that block copolymer A' is the block copolymer before hydrogenation to obtain hydrogenated block copolymer A.

[0098] At this time, the aromatic vinyl polymer chain formed in step (4a) is an aromatic vinyl polymer block Ar2 having a relatively large weight average molecular weight of the hydrogenated block copolymer A constituting the hydrogenated block copolymer composition. a Therefore, the polymerization conditions in step (4a), including the amount of the aromatic vinyl monomer, are determined so as to form such an aromatic vinyl polymer block Ar2. a The polymerization conditions may be determined depending on the target weight average molecular weight, etc. (for example, the polymerization conditions may be determined within the ranges explained in the above step (1)).

[0099] <Process (5a), Process (6a)> The solution containing block copolymer B' and block copolymer A' obtained in step (4a) can be used to obtain the hydrogenated block copolymer composition used in the present invention through the operations in steps (5a) and (6a) described above. Note that steps (5a) and (6a) are similar to steps (6) and (7) described above, and similar conditions can be used for these steps.

[0100] The resin composition of the present invention contains a polyolefin-based thermoplastic resin C in addition to the above-mentioned hydrogenated block copolymer composition.

[0101] The polyolefin-based thermoplastic resin C used in the present invention is not particularly limited as long as it is a thermoplastic resin having an olefin as the main repeating unit, and may be any of an α-olefin homopolymer, a copolymer of two or more α-olefins, and a copolymer of an α-olefin and a monomer other than an α-olefin, or a modified version of these (co)polymers. The polyolefin-based thermoplastic resin C is preferably one that does not substantially contain aromatic vinyl polymer units. Furthermore, the polyolefin-based thermoplastic resin C preferably has an α-olefin unit content of 90% by weight or more, more preferably 95% by weight or more, and even more preferably substantially 100% by weight.

[0102] The polyolefin-based thermoplastic resin C used in the present invention may be a homopolymer or copolymer of an α-olefin such as ethylene or propylene, for example, an α-olefin homopolymer such as polyethylene such as linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), or metallocene polyethylene, polypropylene, metallocene polypropylene, polymethylpentene, or polybutene; a copolymer of ethylene with another α-olefin, for example, an ethylene-propylene random copolymer, an ethylene-propylene block copolymer, an ethylene-butene-1 copolymer, an ethylene-propylene-butene-1 copolymer, or an ethylene-cyclic olefin copolymer; an α-olefin-based copolymer of an α-olefin and an unsaturated alcohol carboxylic acid, or a saponified product thereof, for example, an ethylene-acetic acid copolymer; Examples of suitable resins include vinyl copolymers, ethylene-vinyl alcohol copolymers, copolymers of α-olefins and α,β-unsaturated carboxylic acid esters or α,β-unsaturated carboxylic acids, such as ethylene-α,β-unsaturated carboxylic acid ester copolymers (ethylene-ethyl acrylate copolymers, ethylene-methyl methacrylate copolymers, etc.), and ethylene-α,β-unsaturated carboxylic acid copolymers (ethylene-acrylic acid copolymers, ethylene-methacrylic acid copolymers, etc.); acid-modified olefin resins obtained by modifying α-olefin (co)polymers such as polyethylene or polypropylene with unsaturated carboxylic acids and / or anhydrides thereof, such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, and itaconic acid; ionomer resins obtained by reacting ethylene and methacrylic acid copolymers with sodium ions, zinc ions, etc.; and mixtures thereof. Among these, polypropylene-based resins (i.e., propylene homopolymers or copolymers of propylene as the main component with other α-olefins) are preferred, and propylene homopolymers or copolymers of propylene and ethylene as the main component are more preferred. The polypropylene resin preferably has a propylene unit content of 50% by weight or more, and more preferably has a propylene unit content of 75% by weight or more.The polyolefin-based thermoplastic resin C may be used singly or in combination of two or more kinds.

[0103] Specific examples of the polyolefin-based thermoplastic resin C include a product name "Vistamaxx 6102" (manufactured by Exxon Corporation, a propylene-ethylene copolymer containing propylene units as the main component, ethylene content 16%, MFR 3 g / 10 min (230 °C, 2.16 kg ASTM D1238), density 0.862 g / cm 3 )), trade name "PT-100" (manufactured by LCYCHEMICAL), homopolypropylene, MFR 1.6 g / 10 min (230°C, 21.6 N), melting point 164°C, propylene content 100 mol%, etc. can be used.

[0104] The weight average molecular weight of the polyolefin-based thermoplastic resin C is not particularly limited, but is usually selected in the range of 10,000 to 5,000,000, and preferably selected in the range of 50,000 to 800,000.

[0105] The density of polyolefin thermoplastic resin C is usually 0.80 to 0.95 g / cm 3 is selected in the range of 0.85 to 0.94 g / cm 3 is selected within the range.

[0106] The melt index of the polyolefin thermoplastic resin C is usually selected from the range of 1 to 1000 g / 10 min, preferably 3 to 500 g / 10 min, as a value measured in accordance with ASTM D-1238 (G conditions, 200°C, 5 kg).

[0107] In the resin composition of the present invention, the weight ratio (C / A+B) of the content of polyolefin thermoplastic resin C to the total content of hydrogenated block copolymer A and hydrogenated block copolymer B is preferably 10 / 90 to 90 / 10, more preferably 30 / 70 to 85 / 15, and even more preferably 50 / 50 to 80 / 20. When the content ratio is within this range, the tensile stress, resilience, and impact resistance of the resulting molded article can be improved in a balanced manner.

[0108] The resin composition of the present invention may further contain, as necessary, an antioxidant, a tackifying resin, a softener, an antibacterial agent, a light stabilizer, an ultraviolet absorber, a dye, a lubricant, and the like.

[0109] In addition to the hydrogenated block copolymer composition and the polyolefin-based thermoplastic resin C, the resin composition of the present invention may contain an antioxidant as needed. The type of antioxidant is not particularly limited, and examples include hindered phenol compounds such as pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,6-di-t-butyl-p-cresol, and di-t-butyl-4-methylphenol; thiodicarboxylate esters such as dilauryl thiopropionate; and phosphites such as tris(nonylphenyl)phosphite. The amount of antioxidant used is not particularly limited, but is typically 10 parts by weight or less, preferably 0.5 to 5 parts by weight, per 100 parts by weight of the hydrogenated block copolymer composition. The antioxidants may be used alone or in combination of two or more. Furthermore, the timing of blending the antioxidant into the resin composition is not particularly limited. For example, the antioxidant may be added in advance to the hydrogenated block copolymer composition used to form the resin composition, or may be added when the hydrogenated block copolymer composition and the polyolefin-based thermoplastic resin C are mixed.

[0110] The resin composition of the present invention may contain polymer components other than the hydrogenated block copolymer A, the hydrogenated block copolymer B, and the polyolefin-based thermoplastic resin C, as long as the effects of the present invention are not impaired.

[0111] Examples of polymer components other than the hydrogenated block copolymer A, the hydrogenated block copolymer B, and the polyolefin-based thermoplastic resin C that may be contained in the resin composition of the present invention include aromatic vinyl-conjugated diene-aromatic vinyl block copolymers other than the hydrogenated block copolymer A and the hydrogenated block copolymer B, aromatic vinyl-conjugated diene block copolymers, aromatic vinyl homopolymers, conjugated diene homopolymers, aromatic vinyl-conjugated diene random copolymers, and branched polymers thereof; thermoplastic elastomers such as polyurethane-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, and polyester-based thermoplastic elastomers; thermoplastic resins such as polyvinyl chloride, acrylonitrile-styrene copolymers, acrylonitrile-butadiene-styrene copolymers, and polyphenylene ether; and the like.

[0112] In the resin composition of the present invention, the content of polymer components other than the hydrogenated block copolymer A, the hydrogenated block copolymer B, and the polyolefin-based thermoplastic resin C is preferably 20% by weight or less, more preferably 10% by weight or less, even more preferably 5% by weight or less, particularly preferably 1% by weight or less, and most preferably substantially 0% by weight, based on the total amount of polymer components.

[0113] The resin composition of the present invention can be produced, for example, by mixing the block copolymer composition, the polyolefin-based thermoplastic resin C, and various additives used as needed. The method for mixing these components is not particularly limited, and examples include a method in which each component is heated and melt-mixed using a kneading device such as a Banbury mixer, kneader, Labo Plastomill, single-screw extruder, or twin-screw extruder, or a method in which each component is dissolved in a solvent and mixed uniformly, and then the solvent is removed by heating or the like. Among these, the heated and melt-mixed method is preferred from the viewpoint of more efficient mixing. The temperature during heated and melt-mixing is not particularly limited, but is typically in the range of 100 to 250°C.

[0114] The resin composition of the present invention can also be used as a molded article. A molded article obtained using the resin composition of the present invention has high levels of both tensile stress and restoring force, and is excellent in impact resistance and thermal stability, and therefore can be used in various applications where stretchability, impact resistance, and thermal stability are required.

[0115] The resin composition of the present invention can be used for applications such as packaging films and containers used for packaging clothing, food, daily necessities, industrial materials, etc.; gloves, elastic bands, condoms; various rolls for office equipment and office use; vibration-damping sheets for electrical and electronic equipment; vibration-damping rubber; impact-absorbing sheets; impact-buffering films and sheets; vibration-damping sheets for housing; molding materials used in vibration-damping damper materials; elastic fibers used in clothing, sporting goods, etc.; and various tube materials.

[0116] The molded article obtained using the resin composition of the present invention contains the above-mentioned hydrogenated block copolymer A, hydrogenated block copolymer B, and polyolefin-based thermoplastic resin C. The content ratios of these components in the molded article are the same as the content ratios of these components in the resin composition, and the preferred ranges are also the same.

[0117] The resin composition of the present invention can be molded by, for example, extrusion molding, injection molding, cast molding, or the like, although there are no particular limitations thereon.

[0118] The resin composition of the present invention can be molded by extrusion molding to obtain molded articles in various shapes such as films, sheets, tubes, etc. The extrusion molding method is not particularly limited as long as it employs a molding method in which the resin composition of the present invention is heated to melt the thermoplastic polymer component contained in the resin composition of the present invention, and then extruded from an extruder, and may also be inflation molding in which air is blown into the extruded resin composition.

[0119] The molding temperature when molding the resin composition by extrusion molding is preferably 255° C. or lower, more preferably 250° C. or lower, as the temperature of the resin composition, and the lower limit may be any temperature at which the thermoplastic polymer component contained in the resin composition can be melted, for example, 200° C. or higher. By setting the molding temperature within the above range, a molded product that is homogeneous and has excellent shape uniformity can be obtained.

[0120] The extruder used in the extrusion molding method is not particularly limited, and a single-screw extruder, a twin-screw extruder, or the like can be used.

[0121] Furthermore, by molding the resin composition of the present invention by injection molding, molded articles of any shape, such as packaging containers, can be obtained. The injection molding temperature can be the same as the extrusion molding temperature. The injection molding machine used in the injection molding method is not particularly limited, and any known injection molding machine can be used.

[0122] Furthermore, the resin composition of the present invention can be molded by a cast molding method to obtain a molded article such as a film. In the cast molding method, a solution or dispersion obtained by dissolving or dispersing the resin composition of the present invention in a solvent is cast, and the solvent is removed to form a molded article such as a film.

[0123] The stretchable film of the present invention can be obtained by molding the resin composition of the present invention using the above-mentioned extrusion molding method, cast molding method, or the like. As a method for molding the stretchable film of the present invention, extrusion molding is preferred from the viewpoint of obtaining a smooth stretchable film with good productivity, and among these, extrusion molding using a T-die is more preferred. A specific example of an extrusion molding method using a T-die is a method in which a heated and melted resin composition is extruded at the above-mentioned molding temperature from a T-die attached to a screw extruder such as a single-screw extruder or a twin-screw extruder, and then cooled with a take-up roll while being wound up. The stretchable film may be stretched during cooling with the take-up roll. Furthermore, when winding up the stretchable film, the melted resin composition may be coated onto a substrate made of polyethylene terephthalate, polyethylene, polypropylene, nonwoven fabric, or release paper to form a film, or the melted resin composition may be sandwiched between these substrates to form a film. The stretchable film obtained in this manner may be used as is, integrated with the substrate, or peeled off from the substrate.

[0124] The thickness of the stretchable film is not particularly limited, but is usually 0.01 to 5 mm, preferably 0.03 to 0.5 mm.

[0125] The stretchable film of the present invention can be used as a single layer or laminated with other materials to form a multilayer body, depending on the intended use. Specific examples of its use as a single layer include stretchable films (elastic films) used in sanitary products such as disposable diapers and sanitary napkins, protective films for protecting optical films, and heat-shrinkable films used for shrink-wrapping containers and heat-shrinkable labels. Specific examples of its use as a multilayer body include slitting the film, applying a hot-melt adhesive or the like to the film to form a tape, and then adhering the tape in a shrunk state to a nonwoven fabric, woven fabric, plastic film, or a laminate thereof, and relaxing the shrinkage of the tape to form a stretchable gathered member. Furthermore, depending on the intended use, the film can be appropriately processed according to known methods and used as a stretchable member for, for example, a base material for stretchable patches, gloves, surgical gloves, finger cots, tourniquets, contraceptives, headbands, goggle bands, rubber bands, and the like.

[0126] The sheet of the present invention can be obtained by molding the resin composition of the present invention by the above-mentioned extrusion molding method or the like. The thickness of the sheet of the present invention is not particularly limited, but is usually 0.5 to 30 mm, preferably 1 to 10 mm. The sheet of the present invention can be used for applications such as packaging container materials for packaging clothing, food, daily necessities, industrial materials, etc., vibration-proof sheets for electrical and electronic devices, impact-absorbing sheets, impact-buffering sheets, vibration-damping sheets for housing, vibration-damping damper materials, etc.

[0127] The tube of the present invention can be obtained by molding the resin composition of the present invention by the above-mentioned extrusion molding method or the like. The tube of the present invention can be used, for example, as automotive tubes such as vacuum control tubes, emission control tubes, fuel line tubes, and air brake tubes; tubes for hydraulic equipment, tubes for pneumatic equipment, tubes for centralized lubrication equipment, tubes for painting equipment, tubes for chemical plants, tubes for transferring solvents and chemical solutions, tubes for transferring various liquefied gases, tubes for food-related equipment, tubes for physical and chemical equipment, tubes for metering pumps, tubes for spinning machines, tubes for packaging machines, tubes for printing machines, tubes for transmission machines, tubes for water treatment devices, tubes for fluid elements, tubes for industrial robots, tubes for industrial vehicles, tubes for agricultural machinery, tubes for construction machinery, tubes for machine tools, tubes for injection molding machines, tubes for labor-saving machines, tubes for air tools such as air drivers and air hammers, tubes for moving parts, tubes for pneumatic / electrical signals, tubes for pneumatic / signal signals, tubes for equipment requiring heat resistance, high insulation, and high frequency properties, tubes for various industrial machinery and industrial vehicles such as tubes for spot welding equipment, and tubes for medical equipment. [Example]

[0128] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. Note that "parts" and "%" are by weight unless otherwise specified. The test methods used in the present examples and comparative examples are as follows.

[0129] [Weight average molecular weight, molecular weight distribution] The molecular weight was calculated based on a chart based on polystyrene equivalent molecular weight obtained by high-performance liquid chromatography using tetrahydrofuran as a carrier at a flow rate of 0.35 ml / min. The instrument used was a Tosoh HLC8320, the column consisted of three connected Shodex® KF-404HQ columns manufactured by Showa Denko K.K. (column temperature: 40°C), and the detectors were a differential refractometer and an ultraviolet detector. The molecular weight was calibrated using 12 standard polystyrenes (5 to 3 million) manufactured by Polymer Laboratory.

[0130] [Weight Ratio of Each Block Copolymer in the (Hydrogenated) Block Copolymer Composition] The ratio was determined from the area ratio of the peaks corresponding to each block copolymer in the chart obtained by the above high performance liquid chromatography.

[0131] [Weight average molecular weight of styrene polymer block of (hydrogenated) block copolymer] According to the method described in Rubber Chem. Technol., 45, 1295 (1972), the isoprene polymer block of the (hydrogenated) block copolymer was decomposed by reacting the (hydrogenated) block copolymer with ozone and reducing it with lithium aluminum hydride. Specifically, the procedure was as follows: 300 mg of sample was dissolved in a reaction vessel containing 100 ml of molecular sieve-treated dichloromethane. The reaction vessel was then placed in a cooling bath and cooled to -25°C. Ozone generated by an ozone generator was then introduced into the reaction vessel while oxygen was flowing at a rate of 170 ml / min. Thirty minutes after the start of the reaction, completion of the reaction was confirmed by introducing the gas flowing out of the reaction vessel into an aqueous potassium iodide solution. Next, 50 ml of diethyl ether and 470 mg of lithium aluminum hydride were placed in a separate reaction vessel purged with nitrogen. While the reaction vessel was cooled with ice water, the ozone-reacted solution was slowly added dropwise to the reaction vessel. The reaction vessel was then placed in a water bath, gradually heated, and refluxed at 40°C for 30 minutes. While stirring the solution, dilute hydrochloric acid was gradually added dropwise to the reaction vessel until hydrogen generation was almost completely eliminated. After the reaction, the solid product formed in the solution was filtered and extracted with 100 ml of diethyl ether for 10 minutes. This extract and the filtrate were combined, and the solvent was distilled off to obtain a solid sample. The weight-average molecular weight of the sample thus obtained was measured according to the above-mentioned method for measuring weight-average molecular weight, and the value was taken as the weight-average molecular weight of the styrene polymer block.

[0132] [Weight-average molecular weight of the (hydrogenated) isoprene polymer block of the (hydrogenated) block copolymer] The weight average molecular weight of the corresponding styrene polymer block was subtracted from the weight average molecular weight of the (hydrogenated) block copolymer obtained as described above, and the weight average molecular weight of the (hydrogenated) isoprene polymer block was calculated based on the calculated value.

[0133] [Styrene unit content of (hydrogenated) block copolymer] The styrene content was determined based on the ratio of the detected intensities measured by the differential refractometer and the ultraviolet detector in the high performance liquid chromatography. Copolymers having different styrene unit contents were prepared in advance, and a calibration curve was created using these copolymers.

[0134] [Content of styrene units in the entire (hydrogenated) block copolymer composition] Deuterated chloroform was used as the solvent. 1 It was determined based on H-NMR measurement.

[0135] [Vinyl bond content of (hydrogenated) isoprene polymer block] Deuterated chloroform was used as the solvent. 1 It was determined based on H-NMR measurement.

[0136] [Olefin Hydrogenation Ratio (mole %) of (Hydrogenated) Block Copolymer Composition] Deuterated chloroform was used as the solvent. 1 The olefin amount was determined for each of the block copolymer composition before hydrogenation and the hydrogenated block copolymer composition after hydrogenation by H-NMR spectrum measurement, and the olefin hydrogenation rate (mol %) was calculated based on the difference in the olefin amount before and after hydrogenation. 1 In the H-NMR spectrum measurement, deuterated chloroform was used as the solvent, and a JMN-AL series AL400 (manufactured by JEOL) was used as the NMR measurement device. In addition, in the present examples and comparative examples, both the block copolymer composition before hydrogenation and the hydrogenated block copolymer composition after hydrogenation contained only isoprene units as olefin-derived monomer units, and therefore, in the measurement, the hydrogenation rate of isoprene was determined and this was taken as the olefin hydrogenation rate.

[0137] [Iodine Value of (Hydrogenated) Block Copolymer Composition] Measurement was carried out in accordance with JIS K0070.

[0138] [Melt Index of (Hydrogenated) Block Copolymer Composition] Measurement was performed in accordance with ASTM D-1238 (G condition, 200°C, 5 kg).

[0139] [200% modulus] The films obtained in the Examples and Comparative Examples were cut to prepare 25 mm-wide samples, and one of them was measured along the direction perpendicular to the melt flow during molding. The measurement procedure was as follows: The sample was fixed to an ORIENTEC Tensilon universal testing machine RTC-1210 with a chuck distance of 40 mm without tension. The sample was then stretched to 200% at a rate of 300 mm / min and then returned to the initial chuck distance at a rate of 300 mm / min. The sample was then stretched to 200% again at the same rate and then returned to the initial chuck distance at the same rate. The tensile stress at the second 200% stretch was calculated as the 200% modulus. A higher 200% modulus indicates better tensile stress.

[0140] [Permanent elongation] The films obtained in the examples and comparative examples were measured using the above-mentioned Tensilon universal testing machine along the direction perpendicular to the melt flow during molding in accordance with ASTM 412. Specifically, DieA was used for the sample shape, and the stretchable film was stretched at an elongation rate of 200% with a gauge length of 40 mm before stretching, held in this state for 10 minutes, then suddenly contracted without rebounding, and left for 10 minutes, after which the gauge length was measured and the permanent elongation was calculated according to the following formula. Permanent elongation (%) = (L1-L0) / L0 x 100 L0: Gauge length before stretching (mm) L1: Gauge distance (mm) after shrinking and leaving for 10 minutes The smaller the permanent elongation, the better the restoring force.

[0141] [Bag breaking strength] Two 15 cm x 9 cm pieces of film were cut from the films obtained in the Examples and Comparative Examples. These were then overlapped and heat-sealed on three of the four sides at 140°C, 0.4 MPa, and for 1 second to create a bag. 100 cc of water was poured into the bag through the non-heat-sealed side, and the remaining side was heat-sealed under the same conditions as above to create a liquid packaging container with a capacity of 100 cc. The resulting liquid packaging container was placed on an iron plate at 23°C and then subjected to a drop test in which a 1 kg (9.8 N) iron plate was dropped three times from above the liquid packaging container. The drop test was first performed with the vertical distance from the liquid packaging container to the iron plate set to 10 cm. If the liquid packaging container did not rupture under these conditions, the drop test was repeated with the vertical distance from the liquid packaging container to the iron plate set to 20 cm. Similarly, the vertical distance from the liquid packaging container to the iron plate was increased in 10cm intervals until the liquid packaging container broke, and the upper limit height (cm) at which the bag did not break was used as an index of bag breaking strength. The higher the bag breaking strength index, the better the impact resistance tends to be, and a bag breaking strength index of 40cm or more can be considered to have excellent impact resistance.

[0142] [Viscosity retention rate] The films obtained in the examples and comparative examples were subjected to a thermal degradation test (180°C x 5 hours in the presence of air), and the melt viscosity was measured before and after the thermal degradation test, and the viscosity retention was calculated using the following formula. The higher the viscosity retention, the more excellent the thermal stability of the resin composition. Viscosity retention rate (%) = (melt viscosity after thermal degradation test / melt viscosity before thermal degradation test) x 100 The melt viscosity was measured using a flow tester CFT-500C (Shimadzu Corporation) at a temperature of 180°C and a load of 100 kgf / cm. 2 The measurement was carried out under the condition of a die shape of 1 mm diameter x 10 mm.

[0143] [Production Example 1] (1) Preparation of Block Copolymer Composition Before Hydrogenation A pressure-resistant reactor was charged with 56.6 kg of cyclohexane, 270.6 mmol of ethylene glycol dibutyl ether, and 1.22 kg of styrene. While stirring the entire contents at 40°C, 270.6 mmol of n-butyllithium (1.6 M solution) was added. After the addition was completed, the temperature was raised to 50°C and polymerization reaction was carried out for 1 hour (first stage polymerization). The polymerization conversion of styrene at this time was 100%.

[0144] Subsequently, 6.49 kg of isoprene was continuously added to the reactor over 1 hour while controlling the temperature to maintain a temperature of 50 to 60°C. After the addition of isoprene was completed, the polymerization reaction was carried out for another 1 hour (second stage polymerization). The polymerization conversion of isoprene at this time was 100%.

[0145] Next, 1.22 kg of styrene was continuously added over 1 hour while controlling the temperature to maintain 50-60°C. After the addition of styrene was completed, the polymerization reaction was continued for another hour to obtain a solution containing a styrene-isoprene-styrene triblock copolymer with active terminals (third polymerization stage). The polymerization conversion of styrene at this time was 100%.

[0146] Next, 195 mmol of methanol was added as a polymerization terminator, and the mixture was mixed to deactivate some of the active ends of the styrene-isoprene-styrene triblock copolymer, thereby obtaining a solution containing a styrene-isoprene-styrene triblock copolymer that would become block copolymer B' for obtaining hydrogenated block copolymer B.

[0147] Thereafter, 1.06 kg of styrene was continuously added over 1 hour while maintaining the temperature at 50-60°C. After the addition of styrene was completed, the polymerization reaction was continued for another hour to obtain a solution containing a styrene-isoprene-styrene triblock copolymer having active terminals, which would become block copolymer A' for obtaining hydrogenated block copolymer A (fourth polymerization stage). The polymerization conversion of styrene at this time was 100%.

[0148] Finally, 345 mmol of methanol was added as a polymerization terminator and mixed to deactivate all of the active ends of the styrene-isoprene-styrene triblock copolymer having active ends, thereby completing the polymerization reaction and obtaining a solution containing a block copolymer composition before hydrogenation. The amounts of each reagent used in the reaction are summarized in Table 1.

[0149] (2) Hydrogenation reaction of the block copolymer composition before hydrogenation The solution containing the block copolymer composition before hydrogenation obtained above was subjected to a hydrogenation reaction to obtain a solution containing a hydrogenated block copolymer composition. The hydrogenation reaction was carried out under conditions of a hydrogen pressure of 3 MPa, a reaction temperature of 80°C, and a reaction time of 3 hours, by adding Ni(AcAc)2-TIBAL catalyst as a hydrogenation catalyst to the solution containing the block copolymer composition before hydrogenation obtained above in a ratio of 0.5% based on the block copolymer composition before hydrogenation.

[0150] A portion of the solution containing the hydrogenated block copolymer composition thus obtained was removed, and the weight average molecular weight and molecular weight distribution of the hydrogenated block copolymer composition (as a whole), the weight ratio of each hydrogenated block copolymer in the composition, the weight average molecular weight of the styrene polymer block of each hydrogenated block copolymer, the weight average molecular weight of the hydrogenated isoprene polymer block of each hydrogenated block copolymer, the styrene unit content of each hydrogenated block copolymer, the styrene unit content of the hydrogenated block copolymer composition (as a whole), the vinyl bond content of the hydrogenated isoprene polymer block of each hydrogenated block copolymer, and the olefin hydrogenation rate of the hydrogenated block copolymer composition (as a whole) were determined. These values ​​are summarized in Table 2.

[0151] (3) Recovery of hydrogenated block copolymer composition 0.3 parts of 2,6-di-t-butyl-p-cresol as an antioxidant was added to 100 parts of the solution containing the hydrogenated block copolymer composition obtained as described above and mixed. The mixed solution was added dropwise in small amounts to warm water heated to 85-95°C to volatilize the solvent, yielding a precipitate. The resulting precipitate was crushed and dried with hot air at 85°C to recover a crumb-like hydrogenated block copolymer composition. The crumb-like hydrogenated block copolymer composition was fed into a single-screw extruder equipped with an underwater hot cut device at the tip of the extruder and formed into cylindrical pellets with an average diameter of approximately 5 mm and an average length of approximately 5 mm. The pellets were placed in a hopper dryer heated to 60°C and dried for 10 hours while circulating dry air at 60°C to obtain a hydrogenated block copolymer composition. The iodine value and melt index of the resulting hydrogenated block copolymer composition were measured. The results are summarized in Table 2.

[0152] [Production Example 2] Except for changing the reaction time in the hydrogenation reaction from 3 hours to 1 hour, a hydrogenated block copolymer composition was obtained and measured in the same manner as in Production Example 1. The results are summarized in Table 2.

[0153] [Production Example 3] A hydrogenated block copolymer composition was obtained and measured in the same manner as in Production Example 1, except that the amounts of styrene, ethylene glycol dibutyl ether, n-butyllithium, isoprene, and methanol were changed as shown in Table 1 and the reaction time in the hydrogenation reaction was changed from 3 hours to 15 minutes. The results are summarized in Table 2.

[0154] [Production Example 4] A hydrogenated block copolymer composition was obtained and measured in the same manner as in Production Example 1, except that the amounts of styrene, ethylene glycol dibutyl ether, n-butyllithium, isoprene, and methanol were changed as shown in Table 1 and the reaction time in the hydrogenation reaction was changed from 3 hours to 2 hours. The results are summarized in Table 2.

[0155] [Production Example 5] (1) Preparation of Block Copolymer Composition Before Hydrogenation A pressure reactor was charged with 56.6 kg of cyclohexane, 451.5 mmol of ethylene glycol dibutyl ether, and 1.04 kg of styrene. While stirring the entire contents at 40°C, 451.5 mmol of n-butyllithium (1.6 M solution) was added. After the addition was completed, the temperature was raised to 50°C and polymerization reaction was carried out for 1 hour (first stage polymerization). The polymerization conversion of styrene at this time was 100%.

[0156] Subsequently, 7.99 kg of isoprene was continuously added to the reactor over 1 hour while controlling the temperature to maintain a temperature of 50-60°C. After the addition of isoprene was completed, the polymerization reaction was continued for another hour to obtain a solution containing a styrene-isoprene diblock copolymer having active terminals (second polymerization stage). The polymerization conversion of isoprene at this time was 100%.

[0157] Next, 154 mmol of dimethyldichlorosilane was added as a bifunctional coupling agent, and the mixture was mixed to couple a portion of the styrene-isoprene diblock copolymer having active ends, thereby obtaining a solution containing a styrene-isoprene-styrene triblock copolymer that would become block copolymer B' from which hydrogenated block copolymer B was obtained.

[0158] Thereafter, 0.96 kg of styrene was continuously added over 1 hour while maintaining the temperature at 50-60°C. After the addition of styrene was completed, the polymerization reaction was continued for another 1 hour to obtain a solution containing a styrene-isoprene-styrene triblock copolymer having active terminals, which would become block copolymer A' for obtaining hydrogenated block copolymer A (third polymerization stage). The polymerization conversion of styrene at this time was 100%.

[0159] Finally, 595 mmol of methanol was added as a polymerization terminator and mixed to deactivate all of the active ends of the styrene-isoprene-styrene triblock copolymer having active ends, thereby completing the polymerization reaction and obtaining a solution containing a block copolymer composition before hydrogenation. The amounts of each reagent used in the reaction are summarized in Table 1.

[0160] (2) Hydrogenation reaction of the block copolymer composition before hydrogenation The solution containing the block copolymer composition before hydrogenation obtained above was subjected to a hydrogenation reaction to obtain a solution containing a hydrogenated block copolymer composition. The hydrogenation reaction was carried out under the same conditions as in Production Example 1. A portion of the obtained solution containing the hydrogenated block copolymer composition was then taken out and subjected to the various measurements in the same manner as in Production Example 1. The results are summarized in Table 2.

[0161] (3) Recovery of hydrogenated block copolymer composition Using the obtained solution containing the hydrogenated block copolymer composition, a hydrogenated block copolymer composition was obtained in the same manner as in Production Example 1, and then the same measurements were carried out. The results are summarized in Table 2.

[0162] [Production Example 6] (1) Preparation of Block Copolymer Composition Before Hydrogenation A pressure-resistant reactor was charged with 56.6 kg of cyclohexane, 284.2 mmol of ethylene glycol dibutyl ether, and 1.75 kg of styrene. While stirring the entire contents at 40°C, 284.2 mmol of n-butyllithium (1.6 M solution) was added. After the addition was completed, the temperature was raised to 50°C and polymerization reaction was carried out for 1 hour (first stage polymerization). The polymerization conversion of styrene at this time was 100% by weight.

[0163] Subsequently, 6.49 kg of isoprene was continuously added to the reactor over 1 hour while controlling the temperature to maintain a temperature of 50 to 60°C. After the addition of isoprene was completed, the polymerization reaction was carried out for another 1 hour (second stage polymerization). The polymerization conversion of isoprene at this time was 100%.

[0164] Next, 1.75 kg of styrene was continuously added over 1 hour while controlling the temperature to maintain 50-60°C. After the addition of styrene was completed, the polymerization reaction was continued for another hour to obtain a solution containing a styrene-isoprene-styrene triblock copolymer with active terminals (third polymerization stage). The polymerization conversion of styrene at this time was 100%.

[0165] Finally, 568.4 mmol of methanol was added as a polymerization terminator and mixed to deactivate all of the active ends of the styrene-isoprene-styrene triblock copolymer having active ends, thereby completing the polymerization reaction and obtaining a solution containing a block copolymer composition before hydrogenation. The amounts of each reagent used in the reaction are summarized in Table 1.

[0166] (2) Hydrogenation reaction of the block copolymer composition before hydrogenation The solution containing the block copolymer composition before hydrogenation obtained above was subjected to a hydrogenation reaction to obtain a solution containing a hydrogenated block copolymer composition. The hydrogenation reaction was carried out under the same conditions as in Production Example 1. A portion of the obtained solution containing the hydrogenated block copolymer composition was then taken out and subjected to the various measurements in the same manner as in Production Example 1. The results are summarized in Table 2.

[0167] (3) Recovery of hydrogenated block copolymer composition Using the obtained solution containing the hydrogenated block copolymer composition, a hydrogenated block copolymer composition was obtained in the same manner as in Production Example 1, and then the same measurements were carried out. The results are summarized in Table 2.

[0168] [Production Example 7] Unhydrogenated block copolymer compositions were produced in the same manner as in Production Example 1, except that the amounts of styrene, ethylene glycol dibutyl ether, n-butyllithium, isoprene, and methanol were changed as shown in Table 1 and that no hydrogenation reaction was carried out. Measurements were similarly carried out using the obtained unhydrogenated block copolymer compositions. The results are summarized in Table 2.

[0169] [Production Example 8] Unhydrogenated block copolymer compositions were produced in the same manner as in Production Example 6, except that the amounts of styrene, ethylene glycol dibutyl ether, n-butyllithium, isoprene, and methanol were changed as shown in Table 1 and that no hydrogenation reaction was performed. Measurements were similarly performed using the obtained unhydrogenated block copolymer compositions. The results are summarized in Table 2.

[0170] [Table 1]

[0171] [Table 2]

[0172] Example 1 A mixture of 30 parts of the hydrogenated block copolymer composition obtained in Production Example 1 and a polypropylene resin (trade name "Vistamaxx 6102", manufactured by Exxon Corporation, a propylene-ethylene copolymer containing propylene units as the main component, ethylene content 16%, MFR 3 g / 10 min (230 °C, 2.16 kg ASTM D1238), density 0.862 g / cm 3 was used. 3 70 parts of the resin composition was placed in a twin-screw extruder equipped with a T-die. The mixture was heated, melted, and kneaded at 200°C in the twin-screw extruder to form a resin composition, which was then extruded continuously for 20 minutes between PET release films to form a film with an average thickness of 0.05 mm. The PET release films were then removed to obtain a film. The film forming conditions were as follows: (Film molding conditions) Compound processing speed: 5 kg / hour Film take-up speed: 4m / min Extruder temperature: Adjust to 100°C at the inlet and 200°C at the T-die Screw: Full flight Extruder L / D: 30 T-die: width 200mm, lip 0.5mm

[0173] The resulting film was measured for 200% modulus, permanent elongation, bag breaking strength, and viscosity retention. The results are shown in Table 3.

[0174] [Examples 2 to 5, Comparative Examples 1 to 3] Resin compositions were prepared and films were obtained in the same manner as in Example 1, except that the type of hydrogenated block copolymer composition used was changed as shown in Table 3. The obtained films were then evaluated in the same manner as in Example 1. The results are summarized in Table 3.

[0175] [Table 3]

[0176] As shown in Table 3, when a resin composition containing a hydrogenated block copolymer A represented by general formula (A) and a hydrogenated block copolymer B represented by general formula (B) in a weight ratio A / B of 10 / 90 to 80 / 20, in which the olefin hydrogenation rate in the polymer components constituting the hydrogenated block copolymer composition is 10 to 100%, and a polyolefin-based thermoplastic resin C was used, the resulting film (molded article) had a high level of both tensile stress and restoring force, and was also excellent in impact resistance and thermal stability (Examples 1 to 5).

[0177] On the other hand, when the hydrogenated block copolymer A represented by general formula (A) was not contained, the resulting film (molded article) had poor restoring force, did not achieve a balance between tensile stress and restoring force, and furthermore, was poor in impact resistance (Comparative Example 1). Furthermore, when a block copolymer composition having an olefin hydrogenation rate of less than 10% was used, the resulting film (molded article) had poor thermal stability (Comparative Example 2). Furthermore, when a block copolymer composition was used that did not contain the hydrogenated block copolymer A represented by general formula (A) and had an olefin hydrogenation rate of less than 10%, the resulting film (molded article) had poor restoring force, did not achieve a balance between tensile stress and restoring force, and furthermore, had poor thermal stability (Comparative Example 3).

Claims

1. A resin composition comprising a hydrogenated block copolymer composition having a hydrogenated block copolymer A represented by the following general formula (A) and a hydrogenated block copolymer B represented by the following general formula (B), and a polyolefin-based thermoplastic resin C, In the hydrogenated block copolymer composition, the weight ratio (A / B) of the hydrogenated block copolymer A to the hydrogenated block copolymer B is 10 / 90 to 80 / 20, A resin composition in which the hydrogenation rate of olefin in the polymer components constituting the hydrogenated block copolymer composition is 10 to 100%. Ar1 ａ -HD ａ -Ar2 ａ (A) Ar1 ｂ -HD ｂ -Ar2 ｂ (B) (In the above general formula (A) and general formula (B), Ar1 ａ , Ar2 ａ , Ar1 ｂ , and Ar2 ｂ is an aromatic vinyl polymer block, and HD ａ and HD ｂ is a hydrogenated polymer block of a conjugated diene polymer, and the content of isoprene units including hydrogenated isoprene units in HD a and HD b is 80% by weight or more, respectively; ａ Weight average molecular weight (Mw(Ar1 ａ )) with respect to Ar2 ａ Weight average molecular weight (Mw(Ar2 ａ )) ratio (Mw(Ar2 ａ ) / Mw(Ar1 ａ )) is 2.6 to 66, and Ar1 ｂ Weight average molecular weight (Mw(Ar1 ｂ )) with respect to Ar2 ｂ Weight average molecular weight (Mw(Ar2 ｂ )) ratio (Mw(Ar2 ｂ ) / Mw(Ar1 ｂ )) is 0.95 to 1.

05.

2. 2. The resin composition according to claim 1, wherein the proportion of aromatic vinyl monomer units in all repeating units of the polymer component of the hydrogenated block copolymer composition is 20 to 70% by weight.

3. In the hydrogenated block copolymer composition, HD in the general formula (A) and the general formula (B) ａ and HD ｂ and each of the vinyl bond contents is 1 to 80 mol %.

4. In the hydrogenated block copolymer composition, Ar1 in the general formula (A) and the general formula (B) ａ , Ar1 ｂ , and Ar2 ｂ The weight average molecular weights of the above are in the range of 2,000 to 40,000, and HD ａ and HD ｂ The resin composition according to any one of claims 1 to 3, wherein the weight average molecular weights of the above are in the range of 10,000 to 300,000.

5. 5. The resin composition according to claim 1, wherein a weight ratio (C / A+B) of the content of the polyolefin thermoplastic resin C to the total content of the hydrogenated block copolymer A and the hydrogenated block copolymer B is 10 / 90 to 90 / 10.

6. 6. The resin composition according to claim 1, wherein the weight average molecular weight of all polymer components constituting the hydrogenated block copolymer composition is 30,000 to 400,000.

7. 7. The resin composition according to claim 1, wherein the polyolefin-based thermoplastic resin C is a polypropylene-based resin.

8. A stretchable film made using the resin composition according to any one of claims 1 to 7.

9. A sheet made using the resin composition according to any one of claims 1 to 7.

10. A tube made using the resin composition according to any one of claims 1 to 7.

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