TWI742113B - Block copolymer hydride - Google Patents

Abstract

The subject of the present invention is to provide a novel hydrogenated block copolymer [D] that is advantageous for forming thick optical parts with small dents by maintaining heat resistance and mechanical strength, and improving fluidity during melting.

A hydrogenated block copolymer [D], which is composed of two polymer blocks [A] with a structural unit derived from an aromatic vinyl compound as the main component and a structural unit derived from a chain conjugated diene compound The block copolymer [C] formed by one polymer block [B] as the main component, and the hydrogenated block copolymer [D] formed by hydrogenation, of which two polymer blocks [A] Among them, when the block with the smaller molecular weight is the polymer block [A1] and the block with the larger molecular weight is the polymer block [A2], the polymer block [A1] and the polymer block [A2] ] Has a molecular weight in a specific range.

Description

Block copolymer hydride

The present invention relates to a hydrogenated block copolymer, and particularly to a novel hydrogenated block copolymer having an alicyclic structure.

Hydrogenated ring-opening metathesis polymer obtained by the ring-opening polymerization and hydrogenation of norbornene-based cyclic olefins, or random copolymers of cyclic olefins and ethylene, etc., using these transparency, heat resistance, and low moisture absorption Features such as flexibility and low birefringence are widely used in optical parts such as optical lenses, prisms, mirrors, and optical discs.

On the other hand, Patent Documents 1 and 2 disclose hydrogenated aromatic vinyl compound copolymers in which the aromatic ring of an aromatic vinyl compound polymer is hydrogenated, or a structural unit derived from an aromatic vinyl compound is the main component. The polymer block [A] and the polymer block [B] composed of the structural unit derived from the chain-like conjugated diene compound as the main component. The aromatic ring of the block copolymer [C] and derived from the conjugate The hydrogenated block copolymer [D] of the double bond of a diene compound has excellent light resistance, low birefringence, and heat yellowing resistance, and is especially useful as an optical component and material using blue lasers. In addition, Patent Documents 3 to 5 disclose that the hydrogenated block copolymer [D] has excellent low birefringence, mechanical strength, etc., and is useful as a material for optical films such as retardation films and polarizer protective films.

However, a hydrogenated polymer mainly composed of a structural unit derived from an aromatic vinyl compound is compared with a hydrogenated ring-opening metathesis polymer obtained by ring-opening polymerization and hydrogenation of norbornene-based cyclic olefins, or a ring-opening metathesis polymer hydrogenated product. Random copolymers of olefins and ethylene have a large coefficient of thermal expansion, that is, a large volume change accompanying temperature change. Therefore, for example, when a thick resin molded body having a thick layer portion having a thickness of about 10 mm or more is melt-molded, there is a problem that sink marks are likely to occur.

In addition, the hydrogenated random copolymer in which the aromatic ring of the random copolymer of the aromatic vinyl compound and the chain conjugated diene compound is hydrogenated and the double bond derived from the conjugated diene compound is used to maintain optical parts. The required heat resistance [the index of heat resistance is the glass transition temperature (hereinafter, sometimes referred to as "Tg"), at about 120°C or higher] and mechanical strength, it is necessary to combine an aromatic vinyl compound with a chain-like copolymer. The amount of the conjugated diene compound is limited to about 5 mass% of the total of the aromatic vinyl compound and the chain conjugated diene compound, and the weight average molecular weight is greater than about 100,000. Therefore, the fluidity during melting is poor, and it is necessary to increase the temperature in the molding of optical parts, and it is difficult to reduce the sink marks when melting and molding thick optical parts.

On the other hand, the polymer block [A] whose main component is a structural unit derived from an aromatic vinyl compound and the polymer block [B] whose main component is a structural unit derived from a chain conjugated diene compound The main chain and side chain carbon-carbon unsaturated bonds of the main chain and side chain of the block copolymer [C] and the carbon-carbon unsaturated bonds of the aromatic ring are hydrogenated to obtain the hydrogenated block copolymer [D], Since the polymer block [A] has high heat resistance, it is easy to maintain the heat resistance even if the mass ratio of the polymer block [B] to the hydrogenated block copolymer [D] is increased. Therefore, even if the molecular weight is smaller than that of the hydrogenated random copolymer, the mechanical strength is easily maintained and can be melted at a lower temperature. Melt forming.

However, even if a polymer block [A] mainly composed of a structural unit derived from an aromatic vinyl compound and a structural unit derived from a chain conjugated diene compound as the main component is used, a polymer block [B ] The block copolymer [C] composed of carbon-carbon unsaturated bonds in the main chain and side chains and carbon-carbon unsaturated bonds in the aromatic ring, and hydrogenated block copolymer [D] At this time, when melting and forming thick optical parts, it is not possible to achieve sufficient improvement and easy to produce dents.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2004-83813 A

[Patent Document 2] International Publication No. 2009/084308

[Patent Document 3] JP 2003-114329 A

[Patent Document 4] International Publication No. 2009/067290

[Patent Document 5] International Publication No. 2009/137278

The present invention was completed in view of the above-mentioned prior art to provide optical parts with excellent heat resistance and mechanical strength, and improved fluidity during melting, which can be melt-formed at a lower temperature, and is conducive to the formation of thick layers with small dents. The novel hydrogenated block copolymer [D] is the target.

The inventors have intensively studied to combine two polymer blocks [A] with structural units derived from aromatic vinyl compounds as main components, and Self-chained conjugated diene compound whose structural unit is the main component of 1 polymer block [B] The block copolymer [C] The main chain and side chain carbon-carbon unsaturated bond and aromatic ring The hydrogenated block copolymer [D] obtained by carbon-carbon unsaturated bonding and hydrogenation maintains its heat resistance and mechanical strength while improving fluidity during melting.

As a result, it was found that by making the block with the smaller molecular weight of the two polymer blocks [A] constituting the block copolymer [C] the polymer block [A1], the block with the larger molecular weight In the case of the polymer block [A2], the molecular weight of each of the polymer block [A1] and the polymer block [A2] is in a specific range, so that the total amount of the polymer block [A] accounts for the block copolymerization The mass fraction of the substance [C] is wA, and when the total polymer block [B] accounts for the mass fraction of the block copolymer [C] as wB, the ratio of wA to wB (wA: wB) is specified The carbon-carbon unsaturated bonds of the main chain and side chains of the block copolymer [C] are hydrogenated at a specific ratio or more, and the carbon-hydrogenated carbon unsaturated bonds of the aromatic ring are hydrogenated at a specific ratio or more, The weight average molecular weight Mw[D] of the hydrogenated block copolymer [D] is in a specific range, and the glass transition temperature (Tg ₂ ) of the high-temperature side of the dynamic viscoelasticity of the hydrogenated block copolymer [D] is in a specific range. In the range of the hydrogenated block copolymer [D], the heat resistance and mechanical strength of the hydrogenated block copolymer [D] can be maintained, while the fluidity during melting can be greatly improved. In the case of a thick layer part, a resin molded body with small sink marks can also be obtained, and the present invention has been achieved.

Therefore, according to the present invention, the hydrogenated block copolymer [D] of the following (1) can be provided.

(1) A hydrogenated block copolymer [D] characterized in that it is composed of two polymer blocks [A] with a structural unit of an aromatic vinyl compound as the main component, and a chain-like conjugated polymer block [A] The structural unit of the diene compound is one of the main components The block copolymer [C] of the polymer block [B] has carbon-carbon unsaturated bonds in the main chain and side chains, and carbon-carbon unsaturated bonds in the aromatic ring, and hydrogenated block copolymers obtained by hydrogenation [D], (i) among the two polymer blocks [A] of the block copolymer [C], the block with the smaller molecular weight is the polymer block [A1], and the block with the larger molecular weight When the block is the polymer block [A2], the weight average molecular weight Mw[A1] of the polymer block [A1] is 2,000 to 6,000, and the weight average molecular weight Mw[A2] of the polymer block [A2] is 30,000 Above 50,000,

(ii) Make the total amount of polymer blocks [A] account for the mass fraction of block copolymer [C] as wA, and make the total amount of polymer blocks [B] account for the mass of block copolymer [C] When the score is wB, the ratio of wA to wB (wA:wB) is 70:30~90:10,

(iii) More than 95% of the carbon-carbon unsaturated bonds of the main chain and side chains of the block copolymer [C] are hydrogenated, and more than 95% of the carbon-carbon unsaturated bonds of the aromatic ring are hydrogenated,

(iv) The weight average molecular weight Mw[D] of the hydrogenated block copolymer [D] is 40,000 or more and 70,000 or less,

_{(v) The glass transition temperature (Tg 2} ) on the high temperature side of the dynamic viscoelasticity of the hydrogenated block copolymer [D] is 120°C or higher.

According to the present invention, it is possible to provide a novel hydrogenated block copolymer [D] which has excellent heat resistance and mechanical strength, and can be obtained by a melt molding method to obtain a resin molded body with small sink marks.

According to the present invention, even when it has a thick layer portion (a portion having a thickness of 10 mm or more), a resin molded body with small sink marks can be obtained.

The present invention will be described in detail below.

1) Hydrogenated block copolymer [D]

The hydrogenated block copolymer [D] of the present invention is the precursor of the block copolymer [C]. More than 95% of the carbon-carbon unsaturated bonds of the main chain and side chain are hydrogenated, and the aromatic ring is More than 95% of carbon-carbon unsaturated bonds are hydrogenated to obtain polymers.

(1) Block copolymer [C]

The block copolymer [C] is composed of two polymer blocks [A] and one polymer block [B].

(Polymer block [A])

The polymer block [A] is a polymer block whose main component is a structural unit derived from an aromatic vinyl compound.

In this specification, the so-called polymer block (A) means "a structural unit derived from an aromatic vinyl compound as the main component", which means that the polymer block (A) as a whole is derived from an aromatic vinyl compound The content of the structural unit exceeds 50% by mass.

In addition, the content of the structural unit derived from the aromatic vinyl compound in the polymer block (A) is usually 90% by mass or more, preferably 95% by mass or more, and more preferably 99% by mass or more.

The polymer block (A) may contain components other than the structural unit derived from the aromatic vinyl compound. Examples of other components include structural units derived from chain conjugated diene compounds and/or structural units derived from other vinyl compounds.

The structural unit derived from the chain conjugated diene compound and/or the structural unit derived from another vinyl compound in the polymer block (A) is usually 10% by mass relative to the entire polymer block (A) Below, 5% by mass or less is preferable, and 1% by mass or less is more preferable. When there are too many structural units derived from the chain conjugated diene compound and/or structural units derived from other vinyl compounds in the polymer block (A), the hydrogenated block copolymer of the present invention [ _{In D], the glass transition temperature (Tg 2} ) derived from the hard segment of the polymer block [A] is lowered, which may lower the heat resistance of optical parts composed of the hydrogenated block copolymer [D].

When the polymer block (A) contains a structural unit derived from a chain conjugated diene compound other than the structural unit derived from an aromatic vinyl compound and/or a structural unit derived from another vinyl compound, usually the polymer block The segment (A) preferably has a portion in which a structural unit derived from an aromatic vinyl compound, a structural unit derived from a chain conjugated diene compound, and/or a structural unit derived from another vinyl compound is irregularly repeated.

As long as the above range is satisfied, the plural polymer blocks [A] included in the block copolymer [C] may be the same as or different from each other.

In the present invention, the two polymer blocks [A] constituting the block copolymer [C] have different molecular weights from each other. Among the two polymer blocks [A], when the block with the smaller molecular weight is set as the polymer block [A1], and the block with the larger molecular weight is set as the polymer block [A2], the polymer block [ The weight average molecular weight of A1] (hereinafter sometimes referred to as "Mw[A1]") is 2,000 or more and 6,000 or less, preferably 2,500 or more, more preferably 3,000 or more, particularly preferably 3,900 or more, and 5,500 or less Preferably, it is more preferably 5,000 or less, especially 4,700 or less. The weight average molecular weight of the polymer block [A2] (hereinafter sometimes referred to as "Mw[A2]") is 30,000 or more, and 50,000 or less, and 34,000 The above is better, with 35,000 The above is more preferable, 45,000 or less is more preferable, 41,400 or less is more preferable.

When Mw [A1] is in the above range, the hydrogenated block copolymer [D] of the present invention can be imparted with excellent fluidity when melted. In addition, by setting Mw [A2] in the above range, the hydrogenated block copolymer [D] of the present invention can be imparted with heat resistance and mechanical strength required for optical materials.

(Polymer block [B])

The polymer block [B] is a polymer block whose main component is a structural unit derived from a chain conjugated diene compound.

In this specification, the so-called polymer block (B) means "contains the structural unit derived from the chain conjugated diene compound as the main component", which means that the polymer block (B) as a whole is derived from the chain co The content of the structural unit of the conjugated diene compound exceeds 50% by mass.

Furthermore, the content of the structural unit derived from the chain conjugated diene compound in the polymer block (B) is usually 70% by mass or more, and 80% by mass or more with respect to the entire polymer block (B) Better, more preferably 90% by mass or more.

If the content of the structural unit derived from the chain conjugated diene compound with respect to the entire polymer block (B) is in the above range, good mechanical strength can be imparted.

The polymer block (B) may contain components other than the structural unit derived from the chain conjugated diene compound. Examples of other components include structural units derived from aromatic vinyl compounds and/or structural units derived from other vinyl compounds.

In the polymer block (B), the content of structural units derived from aromatic vinyl compounds and/or structural units derived from other vinyl compounds is usually 30% by mass or less, preferably 20% by mass or less, and 10 The mass% or less is better.

When there are too many components derived from the structural unit of the aromatic vinyl compound and/or the structural unit derived from the other vinyl compound in the polymer block [B], the hydrogenated block copolymer [D] of the present invention _{There is a possibility that the glass transition temperature (Tg 1} ) derived from the soft segment of the polymer block [B] may be increased, and the elasticity of the resin molded body composed of the hydrogenated block copolymer [D] may be reduced.

When the polymer block (B) contains a structural unit derived from an aromatic vinyl compound other than the structural unit derived from a chain conjugated diene compound and/or a structural unit derived from another vinyl compound, the polymer block is usually (B) It is preferable to have a part in which a structural unit derived from an aromatic vinyl compound, a structural unit derived from a chain conjugated diene compound, and/or a structural unit derived from another vinyl compound are irregularly repeated.

(Aromatic vinyl compound)

Aromatic vinyl compounds include styrene; α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-diisopropylstyrene, Styrenes having a C1-C6 alkyl group as a substituent such as 2,4-dimethylstyrene, 4-tert-butylstyrene, 5-tert-butyl-2-methylstyrene, etc. ; 4-chlorostyrene, dichlorostyrene, 4-fluorostyrene and other styrenes with halogen atoms as substituents; 4-methoxystyrene and other alkoxy groups with carbon number 1 to 6 as Styrenes with substituents; styrenes with aryl groups as substituents such as 4-phenylstyrene; vinylnaphthalenes such as 1-vinylnaphthalene and 2-vinylnaphthalene. Among them, from the viewpoint of hygroscopicity, aromatic vinyl compounds without polar groups, such as styrene, styrenes having an alkyl group having 1 to 6 carbons as a substituent, are preferred. It is easy to obtain industrially, so styrene is particularly preferred.

(Chain-shaped conjugated diene compound)

Chain conjugated diene compounds, including 1,3-butadiene, isoprene, 2,3- Dimethyl-1,3-butadiene, 1,3-pentadiene, 2-chloro-1,3-butadiene, etc. Among them, from the viewpoint of low hygroscopicity, chain-like conjugated diene compounds without polar groups are preferred. Since they are easy to obtain industrially, 1,3-butadiene and isoprene are particularly preferred. .

(Other vinyl compounds)

Vinyl compounds used for introducing structural units derived from other vinyl compounds, vinyl compounds other than aromatic vinyl compounds and chain conjugated diene compounds can be used, for example, chain vinyl compounds, Cyclic vinyl compounds, cyclic diene compounds, unsaturated cyclic acid anhydrides, unsaturated amide compounds, etc. These compounds may have a nitrile group, an alkoxycarbonyl group, a hydroxycarbonyl group, or a halogen atom as a substituent. Among them, from the viewpoint of hygroscopicity, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1 -Decene, 1-dodecene, 1-eicosene, 4-methyl-1-pentene, 4,6-dimethyl-1-heptene and other chain vinyl groups with 2 to 20 carbon atoms Compound (chain olefin); C5-20 cyclic vinyl compound (cyclic olefin) such as vinylcyclohexane, 4-vinylcyclohexene, norbornene; 1,3-cyclohexanedi Cyclic diene compounds such as olefins, norbornadiene, etc., which do not contain polar groups are preferred, chain olefin compounds having 2 to 20 carbon atoms are more preferred, and ethylene and propylene are particularly preferred.

(Block copolymer [C])

The block copolymer [C] is the precursor of the hydrogenated block copolymer [D]. The block copolymer [C] is composed of one polymer block [A1], one polymer block [A2], and one polymer block [B]. The block copolymer [C] is a polymer having a triblock structure in the form of [A1]-[B]-[A2].

Make the total amount of polymer block [A] account for the mass of block copolymer [C] The fraction is wA, and when the total polymer block [B] accounts for the mass fraction of the block copolymer [C] as wB, the ratio of wA to wB (wA:wB) is usually 70:30~90: 10. 73:27~88:12 is preferred, 74:26~87:13 is more preferred, and 75:25~85:15 is particularly preferred.

When wA is too large, the mechanical strength of the resin molded body composed of the hydrogenated block copolymer [D] may decrease. If wA is too small, dents may occur in the resin molded body, or the heat resistance of the resin molded body may decrease.

The molecular weight of the block copolymer [C] is the weight average molecular weight (hereinafter referred to as It is written as "Mw[C]".), preferably 40,000 or more, more preferably 45,000 or more, particularly preferably 50,000 or more, preferably 70,000 or less, more preferably 65,000 or less, particularly preferably 60,000 or less. In addition, the molecular weight distribution of the block copolymer [C] (hereinafter sometimes referred to as "Mw[C]/Mn[C]".) is preferably 3 or less, more preferably 2 or less, and particularly preferably 1.5 or less . When Mw[C] and Mw[C]/Mn[C] are in the above ranges, the moldability, mechanical properties, and thermal properties of the molded product can be well balanced.

For the block copolymer [C], for example, the method described in International Publication No. 2003/018656 and International Publication No. 2011/096389 can be used to make monomer component (a) containing an aromatic vinyl compound as a main component and containing It is produced by a method in which the monomer components (b) of which the chain conjugated diene compound is the main component are polymerized with each other. The polymer block [A1] and the polymer block [A2] with different molecular weights can be polymerized first, but by polymerizing the polymer block [A1] first, it is easy to manufacture the polymer block [A1] and the polymer block [A2] Block copolymer [C] where the molecular weight of the segment is more precisely controlled.

(2) Hydrogenated block copolymer [D]

The hydrogenated block copolymer [D] of the present invention hydrogenates the carbon-carbon unsaturated bonds of the main chain and side chains of the block copolymer [C] and the carbon-carbon unsaturated bonds of the aromatic ring .

The hydrogenation rate of the hydrogenated block copolymer [D] is usually 95% or more, preferably 97% or more, and more preferably 99% or more.

In addition, the hydrogenation rate of carbon-carbon unsaturated bonds derived from the main chain and side chains of the chain conjugated diene compound in the block copolymer [C] is usually 95% or more, preferably 98% or more. More than 99% is better.

In addition, the hydrogenation rate of carbon-carbon unsaturated bonds derived from the aromatic ring of the aromatic vinyl compound in the block copolymer [C] is usually 95% or more, preferably 97% or more, and more preferably 99% or more. good.

The higher the hydrogenation rate of the hydrogenated block copolymer [D], the better the weather resistance, heat resistance, and transparency of the resin molded body. The hydrogenation rate of the hydrogenated block copolymer [D] can be obtained by ¹ H-NMR or by comparing the peak areas of the UV detector of GPC and the RI (differential refraction) detector.

The method of hydrogenation of the unsaturated bond, the reaction form, etc. are not particularly limited, and it may be carried out in accordance with a conventional method. A hydrogenation method that can achieve a high hydrogenation rate and less polymer chain scission reaction is preferred. Examples of this hydrogenation method include methods described in International Publication No. 2011/096389 and International Publication No. 2012/043708.

After the completion of the hydrogenation reaction, after removing the hydrogenation catalyst and/or the polymerization catalyst from the reaction solution, the hydrogenated block copolymer [D] can be recovered from the resulting solution. The form of the recovered hydrogenated block copolymer [D] is not limited, and it is usually made into a pellet shape for subsequent molding processing. From the viewpoint of preventing agglomeration, the shape of the pellets is preferably approximately spherical or approximately ellipsoidal.

The molecular weight of the hydrogenated block copolymer [D] is a weight average molecular weight in terms of polystyrene measured by GPC using THF as a solvent (hereinafter sometimes referred to as "Mw[D]"), and is usually 40,000 or more. 45,000 or more is preferable, 49,200 or more is more preferable, 50,000 or more is particularly preferable, usually 70,000 or less, 65,000 or less is preferable, 62,000 or less is more preferable, and 60,000 or less is particularly preferable.

In addition, the molecular weight distribution of the hydrogenated block copolymer [D] (hereinafter sometimes referred to as "Mw[D]/Mn[D]".) is preferably 3 or less, more preferably 2 or less, and 1.5 or less Especially good.

When Mw[D] and Mw[D]/Mn[D] are in the above range, the resin molded body formed from the hydrogenated block copolymer [D] has excellent transparency, low birefringence, etc., heat resistance and mechanical The strength is good. Therefore, for example, when forming an optical component by melt molding such as injection molding, it becomes easier to select molding conditions under which the resin molded body is less likely to cause dents.

Based on the dynamic viscoelasticity of the hydrogenated block copolymer [D], the glass transition temperature Tg ₂ on the high temperature side is 120°C or higher, preferably 123°C or higher.

(Mixing agent)

In order to improve heat stability, light resistance, processability, etc., the hydrogenated block copolymer [D] of the present invention can also be formulated with stabilizers such as oxidation inhibitors, ultraviolet absorbers, and light stabilizers; lubricants, anti-charge It is a compounding agent for resin modifiers, etc. These compounding agents can be used singly or in combination of two or more, and the compounding amount can be appropriately selected within a range that does not impair the purpose of the present invention.

Examples of the anti-oxidation agent include phosphorus-based anti-oxidants, phenol-based anti-oxidants, and sulfur-based anti-oxidants. Among them, specific examples of particularly good protection against oxidants include Pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 2,2-thiodiethylene bis[3-(3,5-di-tert-butyl) -4-hydroxyphenyl)propionate, octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 3,9-bis{2-[3- (3-tert-butyl-4-hydroxy-5-methylphenyl)propenyloxy]-1,1-dimethylethyl-2,4,8,10-tetraoxaspiro[5, 5] Undecane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene and the like.

Examples of ultraviolet absorbers include oxybenzophenone-based compounds, benzotriazole-based compounds, salicylate-based compounds, benzophenone-based compounds, and triazine-based compounds.

The light stabilizer is preferably a hindered amine light stabilizer. Hindered amine light stabilizer, in the structure, with 3,5-di-tert-butyl-4-hydroxyphenyl, 2,2,6,6-tetramethylpiperidinyl, or 1,2,2 , 6,6-Pentamethyl-4-piperidinyl and other compounds.

(use)

The hydrogenated block copolymer [D] of the present invention is excellent in transparency, low birefringence, low hygroscopicity, heat resistance, etc., and it is easy to select a range of molding conditions that reduces the occurrence of sink marks during melt molding. Therefore, it is suitable as an optical lens, a triangular prism, a mirror, an optical disc substrate, a medical inspection unit, a polarizing plate protective film, an optical film in which the in-plane retardation Re and the thickness direction retardation Rth of the film are all less than 5 nm, and a light diffusion plate , Solar cell protective cover, light-weight adhesive glass intermediate sheet, and OCA film forming material. In addition, since the transmittance of megahertz waves at a frequency of 100 GHz to 10 THz is also excellent, it is also suitable as a molding material for optical parts such as megahertz wave penetrating optical parts.

Furthermore, the resin molded body of the hydrogenated block copolymer [D] of the present invention is transparent and has excellent content visibility, and can be steam sterilized or gamma-ray sterilized. Therefore, it is also suitable for use as syringes, pre-filled syringes, vials, ampoules, infusions Medical containers such as bags, eyedrop containers, sample containers, sample tubes for blood tests, blood collection tubes, specimen containers, etc.; culture containers such as plates, biodiscs, porous discs, cell culture containers, bioreactors, etc. And other molding materials. In addition, the hydrogenated block copolymer [D] of the present invention can also be used as bobbins, connectors, LCD TVs, small cameras, power tools, video cameras, microwave ovens, electric pots, pots, vacuum cleaners, personal computers, and photocopying ‧Electronic parts such as sockets, motor sleeves, electric fans, wire coating materials for printers, etc.; architectural interior materials such as wall materials, decorative panels, artificial marble materials, armrest materials, buckets, pipes, etc.; and IC‧ LSI and other semiconductors or hybrid ICs, liquid crystal display components, light-emitting diodes and other electronic parts contact equipment, wafers, liquid crystal substrates, such as laminated transparent electrode layer and protective layer manufacturing intermediate contact equipment, Equipment, etc. (specifically, buckets, trays, carriers, boxes, wafer transport boxes, FOUPs, FOSB, carrier tape, isolation membrane, chemical liquid pipe, valve, flow meter, filter, pump, sampling container, bottle, ampoules and other electronic parts processing equipment); microwave oven container, milk bottle, instant food container, bottle, Materials such as food containers such as tableware.

Among them, as will be described later, the hydrogenated block copolymer [D] and resin composition [E] of the present invention can utilize their characteristics, and are particularly useful as resins having thick layer portions with a thickness of 10 mm or more. The molded body is, for example, a molding material for optical members such as optical lenses (inner lenses for automobile headlights, etc.), prisms, and light guides.

[Examples]

Hereinafter, the present invention will be explained in more detail with examples, but the present invention should not be limited to the following examples. If parts and% are not specifically mentioned, they refer to quality standards.

The evaluation in this example was carried out by the following method.

(1) Weight average molecular weight (Mw) and molecular weight distribution (Mw/Mn)

The molecular weights of the polymer, the block copolymer [C] and the hydrogenated block copolymer [D] in the process of producing the block copolymer [C] are measured by GPC at 38°C using THF as the eluent Standard polystyrene conversion value. As a measuring device, HLC8020GPC manufactured by TOSOH was used.

(2) Hydrogenation rate

The hydrogenation rate of the hydrogenated block copolymer [D] refers to the carbon-carbon unsaturated bond of the aromatic ring contained in the structural unit of the aromatic vinyl compound relative to the block copolymer [C] of the precursor The ratio of the total of carbon-carbon unsaturated bonds contained in the structural unit derived from the chain conjugated diene compound, and the carbon-carbon bond is hydrogenated.

The hydrogenation rate of the hydrogenated block copolymer [D] is ^{calculated by 1} H-NMR spectrum or GPC analysis. The area where the hydrogenation rate is less ^{than 99% is calculated by measuring the 1} H-NMR spectrum, and the area over 99% is calculated by the ratio of the peak area of the UV detector and the RI detector by GPC analysis.

(3) Glass transition temperature (Tg)

The hydrogenated block copolymer [D] was press molded to prepare a test piece having a length of 50 mm, a width of 10 mm, and a thickness of 1 mm. Using this test piece, following the JIS-K7244-4 method, using a viscoelasticity measuring device (manufactured by TA‧Instrument‧Japan Co., Ltd., ARES), the viscosity was measured in the range of -100°C to +150°C at a heating rate of 5°C/min. Elastic spectrum. _{Find the glass transition temperature (Tg 1} ) from the soft segment of the polymer block [B] from the peak first temperature on the low temperature side where tanδ is lost, and find the peak first temperature from the polymer block [ A] The glass transition temperature (Tg ₂ ) of the hard segment of the component.

(4) The ratio of wA to wB (wA: wB)

Regarding making the total mass of polymer blocks [A] account for the mass fraction of the entire block copolymer [C] as wA, and making the total polymer blocks [B] account for the mass of the entire block copolymer [C] When the fraction is wB, the "ratio of wA to wB (wA: wB)" is used in the process of producing the block copolymer [C] to use the aromatic vinyl compound and chain for the polymerization of each polymer block The fractions of conjugated diene compounds and other vinyl compounds are measured by using a gas chromatograph (GC) to determine the polymerization conversion of the monomers used at the end of the polymerization of each polymer block. Rate, to calculate the mass fraction of each polymer block.

(5) Evaluation of the mechanical strength of the resin molded body (molded product)

Using the pellets of the hydrogenated block copolymer [D] to perform injection molding of a thick lens, there is no crack in the gate part during demolding, or a defect in the flange part of the molded lens, it is evaluated as good (○) , When there is rupture or defect, it is rated as bad (×).

(6) Evaluation of dents in injection molded products

The image reflected by the mirror-like flat surface of the thick lens obtained by injection molding pellets of the hydrogenated block copolymer [D] was visually observed, and the presence or absence of dents was determined from the twisted state of the reflected image. The evaluation system is to set a plate with parallel lines drawn in a checkerboard shape at 5 cm intervals on a wall space of 1.25 m away, and to visually observe the reflection image of the parallel lines on the flat surface of the lens to evaluate the distortion. When it was judged that the parallel line distortion was not observed, it was evaluated that the dent was small and good (○), and when distortion was observed, it was evaluated as bad (X).

(7) Evaluation of the heat resistance of molded products

The block copolymer hydrogenated product [D] pellets are injected into the thick layer through injection molding After the mirror was kept in an oven at 100°C for 48 hours, similar to the evaluation of the dents, the reflection image of the parallel lines was visually observed on the flat surface of the lens, and the presence or absence of distortion was observed. When the heat resistance was judged that no parallel line distortion was observed, it was evaluated that the dents were small and good (○), and when distortion was observed, it was evaluated as bad (X).

[Example 1] Hydrogenated block copolymer [D1]

(1) Manufacturing of block copolymer [C1]

In a reactor equipped with a stirring device and sufficiently replaced with nitrogen, 270 parts of dehydrated cyclohexane, 8 parts of dehydrated styrene, and 1.1 parts of dibutyl ether are placed. While stirring the entire volume at 60°C, 0.82 parts of n-butyllithium (15% cyclohexane solution) was added to start polymerization. Then the whole volume was stirred at 60°C for 20 minutes.

At this time (the first stage of polymerization), based on the results of gas chromatograph (hereinafter, sometimes referred to as "GC") and GPC analysis of the reaction solution, the polymerization conversion rate was 99.5%, Mw was 4,200, and Mw/Mn was 1.01 .

Next, 15 parts of dehydrated isoprene was continuously added to the reaction liquid over 40 minutes, and stirring was continued for 30 minutes after the addition was completed.

At this time (the second stage of polymerization), as a result of analyzing the reaction liquid by GC and GPC, the polymerization conversion rate was 99.5%, Mw was 11,700, and Mw/Mn was 1.02.

After that, 77 parts of dehydrated styrene were continuously added to the reaction solution for 200 minutes, and after the addition, the stirring was continued for 60 minutes.

At this time (the third stage of polymerization), as a result of analyzing the reaction solution by GC and GPC, the polymerization conversion rate was about 100%, Mw was 52,600, and Mw/Mn was 1.03.

Here, the reaction was stopped by adding 1.0 part of isopropanol, and a polymer solution containing the block copolymer [C1] of the [A1]-[B]-[A2] type was obtained.

Structure derived from aromatic vinyl compound generated in the third stage of polymerization The Mw of the polymer block [A] whose unit is the main component is calculated as the difference between the Mw in the third stage of the polymerization and the Mw in the second stage of the polymerization. As a result, the Mw of the polymer block [A] produced in the third stage of the polymerization was 40,900.

The obtained block copolymer [C1] had Mw[A1] of 4,200, Mw[A2] of 40,900, Mw[C] of 52,600, and wA:wB of 85:15.

(2) Manufacturing of hydrogenated block copolymer [D1]

Next, the polymer solution was transferred to a pressure-resistant reactor equipped with a stirring device, and 4.0 parts of diatomaceous earth-supported nickel catalyst (product name "E22U", nickel loading capacity 60%, manufactured by Nikkei Catalytic Kasei Co., Ltd.) was added. As a hydrogenation catalyst, 30 parts of dehydrated cyclohexane are mixed. The inside of the reactor was replaced with hydrogen, and hydrogen was further supplied while stirring the solution. The hydrogenation reaction was performed at a temperature of 190°C and a pressure of 4.5 MPa for 6 hours.

The hydrogenated block copolymer [D1] contained in the reaction solution obtained by the hydrogenation reaction had Mw[D1] of 55,800, a molecular weight distribution Mw/Mn of 1.04, and a hydrogenation rate of about 100%.

After the completion of the hydrogenation reaction, the reaction solution was filtered to remove the hydrogenation catalyst, and 0.1 part of pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid dissolved as a phenol-based oxidizing agent was added Dissolve 2.0 parts of a xylene solution of ester (product name "AO60", manufactured by ADEKA).

Next, use a cylindrical concentration dryer (product name "KONTRO", manufactured by Hitachi, Ltd.) to remove cyclohexane, xylene and other volatile components from the solution at a temperature of 260°C and a pressure of 0.001 MPa or less. . The molten polymer was extruded into a strip from a die, and after cooling, pellets of 95 parts of the hydrogenated block copolymer [D1] were produced by a pelletizer.

The obtained pellet-shaped hydrogenated block copolymer [D1] had Mw[D1] of 55,200, Mw/Mn of 1.04, Tg ₁ of -50°C, and Tg ₂ of 128°C.

(Lens molding and evaluation)

The pellets of the hydrogenated block copolymer [D1] were heated in a vacuum dryer at 80°C under reduced pressure for 5 hours to remove dissolved air and moisture. Using the pellets, injection using a metal mold (gate thickness 2.5mm, gate width 4.0mm) equipped with an inner lens for automobile headlights (diameter 48mm, maximum thickness of the center part 15mm) composed of a flat surface and a parabolic surface The molding machine (manufactured by FANUC, ROBOSHOT α-100B) was used for injection molding under the following conditions.

Material pipe temperature: 260℃

Metal mold temperature: 100℃

Cooling time: 260 seconds

Injection pressure (holding pressure): 100MPa

Holding time: 60 seconds.

In the molded inner lens, there was no defect in the flange part or crack in the gate part, and the mechanical strength was evaluated as good (○). As a result of observing the distortion of the reflected image of the flat portion of the molded inner lens, distortion was hardly observed, and the evaluation of dents was good (○). As a result of evaluating the heat resistance of the molded inner lens, distortion was hardly observed in the reflection image of the flat portion after the high-temperature retention, and the heat resistance was evaluated as good (○).

These results are shown in Table 1.

[Example 2] Hydrogenated block copolymer [D2]

(1) Manufacturing of block copolymer [C2]

In the first stage of the polymerization, the dehydrated styrene was changed to 7 parts, the n-butyllithium (15% cyclohexane solution) was 0.78 parts, and in the second stage of the polymerization, the dehydrated isoprene was 20 parts. In the third stage of the polymerization, except that the amount of dehydrated styrene was 73 parts, in the same manner as in Example 1, a polymer solution containing a block copolymer [C2] of the [A1]-[B]-[A2] form was obtained.

(2) Manufacturing of hydrogenated block copolymer [D2]

Using the polymer solution described above, in the same manner as in Example 1, 94 parts of pellets of the hydrogenated block copolymer [D2] were produced.

The value of Mw[A1], Mw[A2] and wA:wB in the block copolymer [C2], and the value of Mw[D2], hydrogenation rate and Tg _{2 in} the hydrogenated block copolymer [D2] Recorded in Table 1.

(Lens molding and evaluation)

Using the pellets of the hydrogenated block copolymer [D2], injection molding of the inner lens was performed in the same manner as in Example 1, and the mechanical strength, the generation of dents, and the evaluation of heat resistance were performed. The results are shown in Table 1.

[Example 3] Hydrogenated block copolymer [D3]

(1) Manufacturing of block copolymer [C3]

In the first stage of polymerization, 8 parts of dehydrated styrene and 0.72 parts of n-butyl lithium (15% cyclohexane solution) were changed. In the second stage of polymerization, 25 parts of dehydrated isoprene was changed. At the stage, except that the amount of dehydrated styrene was 67 parts, a polymer solution containing a block copolymer [C3] in the form of [A1]-[B]-[A2] was obtained in the same manner as in Example 1.

(2) Manufacturing of hydrogenated block copolymer [D3]

Using the polymer solution described above, in the same manner as in Example 1, 96 parts of pellets of the hydrogenated block copolymer [D3] were produced.

The values of Mw[A1], Mw[A2] and wA:wB of the block copolymer [C3], and the values of Mw[D3], hydrogenation rate, and Tg ₂ of the hydrogenated block copolymer [D3] are described in Table 1.

(Lens molding and evaluation)

Using pellets of the hydrogenated block copolymer [D3], injection molding of the inner lens was performed in the same manner as in Example 1, and the mechanical strength, the generation of dents, and the evaluation of heat resistance were performed. The results are shown in Table 1.

[Example 4] Hydrogenated block copolymer [D4]

(1) Manufacturing of block copolymer [C4]

In the first stage of the polymerization, the dehydrated styrene was changed to 10 parts and the n-butyllithium (15% cyclohexane solution) was 0.91 parts. In the second stage of the polymerization, the dehydrated isoprene was 20 parts. At the stage, except that the amount of dehydrated styrene was 70 parts, in the same manner as in Example 1, a polymer solution containing a block copolymer [C4] of the [A1]-[B]-[A2] form was obtained.

(2) Manufacturing of hydrogenated block copolymer [D4]

Using the polymer solution described above, in the same manner as in Example 1, 94 parts of pellets of the hydrogenated block copolymer [D4] were produced.

The values of Mw[A1], Mw[A2] and wA:wB of the block copolymer [C4], and the values of Mw[D4], hydrogenation rate and Tg ₂ of the hydrogenated block copolymer [D4] are described in Table 1.

(Lens molding and evaluation)

Using pellets of the hydrogenated block copolymer [D4], injection molding of the inner lens was performed in the same manner as in Example 1, and the mechanical strength, the generation of dents, and the evaluation of heat resistance were performed. The results are shown in Table 1.

[Comparative Example 1] Hydrogenated block copolymer [D5]

(1) Manufacturing of block copolymer [C5]

In the first stage of the polymerization, the dehydrated styrene was changed to 10 parts and the n-butyllithium (15% cyclohexane solution) was 0.61 part. The polymerization was started, and then 30 parts of dehydrated styrene were continuously added in 80 minutes. A block copolymer containing [A1]-[B]-[A2] form was obtained in the same manner as in Example 1, except that the amount of dehydrated isoprene was 20 parts in the third stage of the polymerization and 40 parts of dehydrated styrene was used in the third stage of the polymerization.物[C5] polymer solution.

(2) Manufacturing of hydrogenated block copolymer [D5]

Using the polymer solution described above, in the same manner as in Example 1, 94 parts of pellets of the hydrogenated block copolymer [D5] were produced.

The values of Mw[A1], Mw[A2] and wA:wB of the block copolymer [C5], and the values of Mw[D5], hydrogenation rate, and Tg ₂ of the hydrogenated block copolymer [D5] are described in Table 1.

(Lens molding and evaluation)

Use block copolymer hydrogenation [D5] pellets, use the same injection molding machine and metal mold as in Example 1, appropriately change the barrel temperature, metal mold temperature, cooling time, injection pressure (holding pressure), and hold the pressure Time, etc., perform injection molding of the inner lens, and evaluate the mechanical strength, the generation of dents, and the heat resistance. The results are shown in Table 1.

[Comparative Example 2] Hydrogenated block copolymer [D6]

(1) Manufacturing of block copolymer [C6]

In the first stage of the polymerization, the dehydrated styrene was changed to 10 parts, the n-butyl lithium (15% cyclohexane solution) was 0.81 part, and the polymerization was started, and then 30 parts of dehydrated styrene were continuously added over 80 minutes. The stage makes the dehydrated isoprene 20 In the third stage of the polymerization, except that the dehydrated styrene was 40 parts, in the same manner as in Example 1, a polymer solution containing a block copolymer [C6] in the form of [A1]-[B]-[A2] was obtained.

(2) Manufacturing of hydrogenated block copolymer [D6]

Using the above polymer solution, in the same manner as in Example 1, 91 parts of pellets of the hydrogenated block copolymer [D6] were produced.

The values of Mw[A1], Mw[A2] and wA:wB of the block copolymer [C6], and the values of Mw[D6], hydrogenation rate and Tg ₂ of the hydrogenated block copolymer [D6] are described in Table 1.

(Lens molding and evaluation)

Use block copolymer hydrogenation [D6] pellets, use the same injection molding machine and metal mold as in Example 1, appropriately change the barrel temperature, metal mold temperature, cooling time, injection pressure (holding pressure), and hold the pressure Time, etc., perform injection molding of the inner lens, and evaluate the mechanical strength, the generation of dents, and the heat resistance. The results are shown in Table 1.

[Comparative Example 3] Hydrogenated block copolymer [D7]

(1) Manufacturing of block copolymer [C7]

In the first stage of the polymerization, the dehydrated styrene was changed to 10 parts, the n-butyl lithium (15% cyclohexane solution) was 0.72 parts, and the polymerization was started, and then 10 parts of dehydrated styrene were continuously added in 25 minutes. A block copolymer containing [A1]-[B]-[A2] form was obtained in the same manner as in Example 1, except that the amount of dehydrated isoprene was 20 parts in the third stage of polymerization and 60 parts of dehydrated styrene was used in the third stage of the polymerization.物[C7] polymer solution.

(2) Manufacturing of hydrogenated block copolymer [D7]

Using the polymer solution described above, in the same manner as in Example 1, 95 parts of pellets of the hydrogenated block copolymer [D7] were produced.

The values of Mw[A1], Mw[A2] and wA:wB of the block copolymer [C7] and the values of Mw[D7], hydrogenation rate and Tg ₂ of the hydrogenated block copolymer [D7] are described in Table 1.

(Lens molding and evaluation)

Using the pellets of the hydrogenated block copolymer [D7], using the same injection molding machine and metal mold as in Example 1, appropriately changing the barrel temperature, metal mold temperature, cooling time, injection pressure (holding pressure), and holding pressure Time, etc., perform injection molding of the inner lens, and evaluate the mechanical strength, the generation of dents, and the heat resistance. The results are shown in Table 1.

[Comparative Example 4] Hydrogenated block copolymer [D8]

(1) Manufacturing of block copolymer [C8]

In the first stage of polymerization, 10 parts of dehydrated styrene and 0.73 parts of n-butyllithium (15% cyclohexane solution) were changed. In the second stage of polymerization, 40 parts of dehydrated isoprene were continuously added for 100 minutes. In the third stage of the polymerization, a polymer solution containing a block copolymer [C8] in the form of [A1]-[B]-[A2] was obtained in the same manner as in Example 1, except that the amount of dehydrated styrene was 50 parts.

(2) Manufacturing of hydrogenated block copolymer [D8]

Using the above polymer solution, in the same manner as in Example 1, 93 parts of pellets of the hydrogenated block copolymer [D8] were produced.

The values of Mw[A1], Mw[A2] and wA:wB of the block copolymer [C8], and the values of Mw[D8], hydrogenation rate and Tg ₂ of the hydrogenated block copolymer [D8] are described in Table 1.

(Lens molding and evaluation)

Using the pellets of hydrogenated block copolymer [D8], using the same injection molding machine and metal mold as in Example 1, appropriately changing the barrel temperature, metal mold temperature, cooling time, injection pressure (holding pressure), and holding pressure Time, etc., perform injection molding of the inner lens, and evaluate the mechanical strength, the generation of dents, and the heat resistance. The results are shown in Table 1.

[Comparative Example 5] Hydrogenated block copolymer [D9]

(1) Manufacturing of block copolymer [C9]

In the first stage of the polymerization, the dehydrated styrene was changed to 10 parts, the n-butyl lithium (15% cyclohexane solution) was 0.70 parts, and the polymerization was started, and then 70 parts of dehydrated styrene were continuously added over 200 minutes. A polymer solution containing [A]-[B] type block copolymer [C9] was obtained in the same manner as in Example 1 except that the amount of dehydrated isoprene was adjusted to 20 parts at a stage.

(2) Manufacturing of hydrogenated block copolymer [D9]

Using the polymer solution described above, in the same manner as in Example 1, 82 parts of pellets of the hydrogenated block copolymer [D9] were produced.

The values of Mw[A] and wA:wB of the block copolymer [C9], and the values of Mw[D9], hydrogenation rate, and Tg ₂ of the hydrogenated block copolymer [D9] are shown in Table 1.

(Lens molding and evaluation)

Using the pellets of hydrogenated block copolymer [D9], using the same injection molding machine and metal mold as in Example 1, appropriately changing the barrel temperature, metal mold temperature, cooling time, injection pressure (holding pressure), and holding pressure Inject molding of the inner lens was performed over time, and the mechanical strength, dent generation, and heat resistance were evaluated. However, the mechanical strength was low, and the flange portion and gate portion were broken, and a good shape of the lens could not be molded. mirror. The results are shown in Table 1.

From the results of the Examples and Comparative Examples in Table 1, the following can be seen.

In the [A1]-[B]-[A2] type of two polymer blocks [A1] and polymer block [A2] that have structural units derived from aromatic vinyl compounds as main components and different molecular weights The hydrogenated triblock copolymer [C] The hydrogenated block copolymer [D], Mw[A1], Mw[A2], wA: wB, Mw[D] and Tg ₂ are within the scope of the present invention In the injection molding of a thick-layer lens of the hydrogenated block copolymer [D], good results were obtained in the evaluation of mechanical strength, dents of the molded lens, and heat resistance of the lens (Examples 1 to 4).

In the case of the hydrogenated block copolymer [D] with almost the same Mw[A1] and Mw[A2], in order to _{maintain heat resistance with the same Tg 2} , the molecular weight Mw [D] needs to be increased, even if it is changed appropriately It is also difficult to suppress the occurrence of dents in the injection molding barrel temperature, metal mold temperature, cooling time, injection pressure (holding pressure), holding pressure time, etc. (Comparative Example 1).

In the case of the hydrogenated block copolymer [D] with almost the same Mw[A1] and Mw[A2], in order to maintain the melt moldability with the same molecular weight Mw[D], the Tg ₂ will decrease and the molded thickness The heat resistance of the laminated lens is insufficient (Comparative Example 2).

In the [A1]-[B]-[A2] type triblock copolymer [C] hydrogenated block copolymer [D], Mw[ A1] When the range of the present invention is larger, the fluidity during melt molding is poor, and even if the barrel temperature, mold temperature, cooling time, injection pressure (holding pressure), holding time, etc. are changed appropriately, it is difficult to suppress dents. The occurrence of scars (Comparative Example 3).

Different from Mw[A1] and Mw[A2], Mw[A1] and Mw[A2] are within the scope of the present invention [A1]-[B]-[A2] type triblock copolymer [C] The hydrogenated block copolymer hydrogenated product [D], in wA:wB, when wB is larger than the range of the present invention, even if the barrel temperature, metal mold temperature, cooling time, and injection pressure (guaranteed Since the molded product becomes soft, such as pressure and holding time, dents and distortion of the surface shape may occur in the molding of a thick lens, and it is difficult to obtain a good lens (Comparative Example 4).

Even the hydrogenated block copolymer [D] whose molecular weight Mw[D] and wA:wB are within the scope of the present invention has no polymer block [A1] at the end of the [A]-[B] type diramid The hydrogenated segment copolymer [D] does not have sufficient mechanical strength as a molding material, and it is difficult to mold a good-shaped lens (Comparative Example 5).

【Industrial Profitability】

The specific hydrogenated block copolymer [D] of the present invention can maintain heat resistance and mechanical strength while improving fluidity during melting. Even if it has a thick layer part, it is also beneficial for molding resin molded bodies with small dents. Polymer Materials. The hydrogenated block copolymer [D] of the present invention is particularly useful as a surface accuracy requirement The molding material of optical parts.

Claims (1)

A hydrogenated block copolymer [D], which is composed of two polymer blocks [A] with a structural unit derived from an aromatic vinyl compound as the main component, and a structural unit derived from a chain conjugated diene compound as the main component The block copolymer [C] formed by the main component of one polymer block [B], and the hydrogenated block copolymer [D] formed by hydrogenation, is characterized by: (i) in the block copolymer Among the two polymer blocks [A] of [C], when the smaller molecular weight block is used as the polymer block [A1], and the larger molecular weight block is used as the polymer block [A2], polymerization The weight average molecular weight Mw[A1] of the polymer block [A1] is 2,000 to 6,000, the weight average molecular weight of the polymer block [A2] is 30,000 to 50,000, and the block copolymer [C] is A1]-[B]-[A2] type triblock copolymer; (ii) The mass fraction of the total polymer block [A] in the block copolymer [C] is taken as wA, and the polymerization When the mass fraction of the total amount of the block [B] in the block copolymer [C] is taken as wB, the ratio of wA to wB (wA:wB) is 70:30~90:10; (iii) block copolymerization More than 95% of the carbon-carbon unsaturated bonds of the main chain and side chains of the compound [C] are hydrogenated, and more than 95% of the carbon-carbon unsaturated bonds of the aromatic ring are hydrogenated; (iv) block copolymers The weight average molecular weight Mw [D] of the hydrogenated product [D] is 40,000 or more and 70,000 or less; (v) The glass transition temperature (Tg ₂ ) on the high temperature side of the dynamic viscoelasticity of the hydrogenated block copolymer [D] is 120°C above.