JP2001139798A - Polyphenylene ether resin composition having vibration damping property - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve vibration damping properties of a flame-retardant and a nonflame-retardant resin composition of a polyphenylene ether resin or a resin composition containing a polyolefin resin therewith. SOLUTION: This resin composition is composed of (A) 40-90 pts.wt. of the polyphenylene ether resin, (B) 5-35 pts.wt. of a specific block copolymer composed of a polymer block of a styrene-based compound and a random copolymer block of a butadiene-based and the styrene-based compound, (C) 0-20 pts.wt. of the polyolefin resin and (D) 0-30 pts.wt. of a phosphate-based flame retardant. The (B) and (C) components of the resin composition form a dispersed phase and mean diameter thereof is within the range of 0.2-4 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyphenylene ether resin composition having a damping property.

[0002]

2. Description of the Related Art Polyphenylene ether resin compositions are widely used in the field of home appliances and office machines because of their excellent dimensional stability and electrical properties. In recent years, attention has been paid to environmental problems such as noise and vibration, so that structural materials are often required to have vibration damping properties.

On the other hand, in the field of information equipment, a high-speed rotation has been required of a driving unit with a large increase in information capacity and processing speed. When the drive unit rotates at a high speed, vibration is naturally likely to occur, and reading errors and malfunctions are likely to occur. Therefore, polyphenylene ether resins widely used in the fields of home electric appliances, office machines and information equipment naturally require vibration damping properties.

[0004] Originally, polyphenylene ether resin is not always excellent in damping property, but it is known that the damping property can be improved by blending an elastomer component. This is because the elastomer component absorbs vibration energy, but on the other hand, the rigidity is remarkably reduced, so that it is insufficient for use as a structural material. Among the elastomers, those having Tg near room temperature are more excellent in damping effect. As a method for improving the vibration damping properties of a polyphenylene ether resin, Japanese Patent Application Laid-Open Nos. Hei 3-181552 and Hei 11-12457 disclose, for example, a method comprising a vinyl aromatic polymer block and an isoprene or isoprene-butadiene block. A method of adding an unhydrogenated or hydrogenated block copolymer having a main dispersion peak of tan δ above C has already been disclosed. However, although the addition of such a block copolymer also gives the composition good damping properties, the degree of rigidity reduction of the composition is large, and is not necessarily sufficient for use as a structural material.

As a method for controlling the Tg of an elastomer to around room temperature, in a block copolymer comprising a polymer block of a styrene compound and a polymer block of butadiene, a styrene compound is randomly copolymerized with a butadiene polymer block. Then, there is a method of shifting Tg to the room temperature side. Also, a technique relating to a resin composition containing a polyphenylene ether resin and a block copolymer of a vinyl aromatic polymer block, a butadiene and a vinyl aromatic hydrogenated random copolymer block, and a resin composition containing a polyolefin resin are specially described. Although disclosed in Japanese Unexamined Patent Publication No. Hei 4-183748, this technique is intended to improve the impact resistance and chemical resistance of a polyphenylene ether resin composition, and a resin composition having excellent vibration damping properties is provided. It does not indicate the proper range of the product.

When resin materials are used in the fields of home appliances, office machines and information equipment, flame retardancy is required in most cases. In the case of flame retardation, the use of a halogen compound or antimony trioxide does not meet the demands of the times, and it is environmentally preferable if the flame retardation can be achieved with phosphoric esters. Therefore, an object of the present invention is to provide a non-flame-retardant and flame-retardant resin composition which can be effectively used in the field of home appliances, office machines and information devices, has a small decrease in rigidity, and has excellent vibration damping properties.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies with the aim of obtaining a polyphenylene ether resin composition having excellent vibration damping properties that do not adversely affect the environment. Consisting of a polymer block of a styrene-based compound and a random copolymer block of butadiene and a styrene-based compound.
By adding a block copolymer showing a main dispersion peak of anδ, good vibration damping performance is given, and the rigidity is reduced compared to the case where an elastomer having a copolymer block of butadiene or isoprene as a soft segment is simply added. In order to have sufficient damping effect and flame retardancy, the block copolymer resin forms a dispersed phase and has a proper range of dispersed particle diameter. The present invention has been found that the flame retardant effect is dramatically improved when used, and that the temperature of the main dispersion peak of tan δ can be increased by using polyolefin in combination,
A polyphenylene ether resin composition having excellent vibration damping properties can be provided.

That is, the present invention provides: (A) 40 to 90 parts by weight of a polyphenylene ether resin or a polystyrene resin and (B) a random copolymer of butadiene and a styrene compound having a total content of polymer blocks and vinyl bonds of a styrene compound of 20% by weight or more. The styrene-based compound in the random copolymer block accounts for 30 to 60% by weight of the total components, and the styrene-based compound polymer block accounts for 8 to 50% by weight of the total components. Polystyrene reduced number average molecular weight 50,000-300,000
5 to 35 parts by weight of a block copolymer resin in the range of
(C) 0 to 20 parts by weight of polyolefin resin and (D)
It contains 0 to 30 parts by weight of a phosphoric ester flame retardant, and the components (B) and (C) form a dispersed phase, and the average diameter of the dispersed particles is in the range of 0.2 to 4 μm. Polyphenylene ether resin composition,

[0009] 2. In the above item (1), there is provided a polyphenylene ether-based resin composition having vibration damping properties, comprising a resin composition wherein the butadiene portion of the random copolymer block of the component (B) is hydrogenated by 70% or more. is there.

The present invention will be described in more detail. In the present invention, when the component (C) is not contained, the dispersed particle diameter tends to be small. The addition of the component (C) increases the size of the dispersed particles and also increases the temperature of the main dispersion peak of tan δ, so that the effect of improving the vibration damping property is large. However, if the component (C) is added more than necessary, the dispersed particles become too large to make it flame-retardant, and the rigidity of the molded product decreases.
The range of the dispersed particle diameter in which the effect of improving the vibration damping property is sufficiently exerted and which can be made flame-retardant by using a phosphate ester-based flame retardant is in the range of 0.2 to 4 μm. The particle diameter of the dispersed phase is represented by an arithmetic mean of the major axis and the minor axis of the dispersed phase obtained from an electron micrograph.

When the components (B) and (C) form a continuous phase, even if a phosphate ester-based flame retardant is used, it becomes difficult to achieve the required level of flame retardancy. In the case of flame retardancy, even if the components (B) and (C) form a dispersed phase, the purpose cannot be achieved because the flame retardant effect is poor except for the phosphoric ester-based flame retardant. Only when a phosphate ester-based flame retardant is used, the reason why the flame-retardant effect is large is that the polyphenylene ether-based resin component is apt to be charred, and this char forms a protective film to make it difficult for the components (B) and (C) to burn. It is supposed to be. It is considered that the larger the diameter of the dispersed particles composed of the components (B) and (C) becomes, the more the particles cannot be protected by the char, and the lower the flame retardant effect is.

The polyphenylene ether resin as the component (A) of the present invention is represented by the following general formula (1):

Embedded image

(Wherein R 1, R 2, R 3, R 4, R 5, and R 6 are monovalent residues such as an alkyl group having 1 to 4 carbon atoms, an aryl group, halogen, and hydrogen, and R 5 and R 6 are hydrogen at the same time. ) Is used as a repeating unit, and a homopolymer or a copolymer whose structural unit is composed of [a] and [b] of the general formula (1) can be used.

A typical example of the homopolymer of polyphenylene ether resin is poly (2,6-dimethyl-1,4-
Phenylene) ether, poly (2-methyl-6-ethyl-1,4-phenylene) ether, poly (2,6-diethyl-1,4-phenylene) ether, poly (2-ethyl-6-n-propyl-) 1,4-phenylene) ether, poly (2,6-di-n-propyl-1,4-phenylene) ether, poly (2-methyl-6-n-butyl-
1,4-phenylene) ether, poly (2-ethyl-6)
-Isopropyl-1,4-phenylene) ether, poly (2-methyl-6-chloroethyl-1,4-phenylene) ether, poly (2-methyl-6-hydroxyethyl-1,4-phenylene) ether, poly ( Homopolymers such as 2-methyl-6-chloroethyl-1,4-phenylene) ether are exemplified.

[0015] The polyphenylene ether copolymer is 2,2
Copolymer of 6-dimethylphenol and 2,3,6-trimethylphenol or copolymer of o-cresol or 2,3,6-trimethylphenol and o-cresol
Includes polyphenylene ether copolymers having a polyphenylene ether structure as a main component, such as copolymers with cresol.

In the polyphenylene ether resin of the present invention, various other phenylene ether units which have been proposed to be allowed to exist in the polyphenylene ether resin so far as they do not contradict the gist of the present invention are partially used. It may be included as a structure. Japanese Patent Application No. 63-12 / 1988 discloses an example of the proposal for coexistence in a small amount.
No. 698 and JP-A-63-301222, 2- (dialkylaminomethyl) -6-
Examples thereof include a methylphenylene ether unit and a 2- (N-alkyl-N-phenylaminomethyl) -6-methylphenylene ether unit.

The polyphenylene ether resin also includes those in which a small amount of diphenoquinone or the like is bonded in the main chain.
Further, for example, Japanese Unexamined Patent Application Publication No.
108059 and JP-A-59-59724, which include polyphenylene ethers modified with compounds having a carbon-carbon double bond. The component (A) can contain a polystyrene-based resin in an arbitrary ratio in addition to the polyphenylene ether resin. The polystyrene-based resin is a polymer obtained by polymerizing a styrene-based compound or a compound copolymerizable with the styrene-based compound in the presence or absence of a rubbery polymer.

Styrene compounds are represented by the general formula [2]

Embedded image

(Wherein, R represents hydrogen, lower alkyl or halogen, Z is selected from the group consisting of vinyl, hydrogen, halogen and lower alkyl, and p is an integer of 0 to 5). Means a compound.

Specific examples of these include styrene, α-
Examples thereof include methylstyrene, 2,4-dimethylstyrene, monochlorostyrene, p-methylstyrene, p-tert-butylstyrene, and ethylstyrene. Examples of the compound copolymerizable with the styrene compound include methacrylic acid esters such as methyl methacrylate and ethyl methacrylate; unsaturated nitrile compounds such as acrylonitrile and methacrylonitrile; and acid anhydrides such as maleic anhydride. And used together with styrenic compounds. Examples of the rubbery polymer include a conjugated diene rubber, a copolymer of a conjugated diene and an aromatic vinyl compound, a hydrogenated product thereof, and an ethylene-propylene copolymer rubber. Preferred styrenic resins for the present invention are polystyrene and rubber reinforced polystyrene.

The block copolymer as the component (B) in the present invention is a block comprising at least one polymer block of a styrene compound and at least one random copolymer block of butadiene and a styrene compound. It is a copolymer resin. The total vinyl content of 1,2-bonds in the butadiene portion of the random copolymer block must be at least 20% by weight, preferably from 20 to 6%.
It is in the range of 0% by weight. Total vinyl content of 20% by weight
When the temperature is less than the above, the temperature of the main dispersion peak of tan δ is low, and it is not preferable because the temperature cannot be increased to a sufficient level to exhibit the vibration damping property even when the polyolefin resin is used in combination.

The preferred range of the ratio of the styrene-based compound to the total components in the random copolymer block is 30 to 6
0% by weight, more preferably 30 to 40% by weight.
% By weight. When the styrene compound is less than 30% by weight, the temperature of the main dispersion peak of tan δ is low,
Even if a polyolefin-based resin is used in combination, it is not preferable because the temperature cannot be raised to a temperature sufficient to exhibit the vibration damping property. If it exceeds 60% by weight, the main dispersion peak of tan δ becomes small, and a sufficient vibration damping effect is obtained. It is not preferable because it cannot be performed.

The preferred range of the content of the styrene compound polymer block in the block copolymer is selected from the range of 8 to 50% by weight, more preferably 11 to 35% by weight, and particularly preferably 15 to 25% by weight. % By weight. When the content of the polymer block of the styrenic compound is less than 8% by weight, the compatibility with the component (A) becomes insufficient, and the molded product is easily delaminated.
In the case where the ratio exceeds 0.1%, the dispersion particles are 0.1% even when the component (C) is added.
Since it is less than 2 μm, a sufficient vibration damping effect cannot be obtained, which is not preferable. In the case where the component (C) is not added, if the content exceeds 35% by weight, the dispersed particles become 0.2 μm or less.

The preferred range of the molecular weight of the block copolymer is the number average molecular weight in terms of polystyrene of 50,000 to 300,
50,000, more preferably 50,000.
To 230,000, particularly preferably 70,000 to 15
It is in the range of 0000. If the molecular weight of the block copolymer is less than 50,000, the compatibility with the component (A) is insufficient, so that the molded product tends to be delaminated. The addition of the component is not preferred because the dispersed particles are less than 0.2 μm and a sufficient damping effect cannot be obtained. If the component (C) is not added, if it exceeds 230,000, the dispersed particles will be 0.2 μm or less.

When the unsaturated bond occupying 30% or more of the butadiene portion of the random copolymer block remains, the flow of the composition may be lowered by heat and the appearance of the molded article may be deteriorated. More preferably, 70% or more is hydrogenated. The polyolefin-based resin itself as the component (C) of the present invention is a known one, for example, a homopolymer of an olefin-based monomer such as polyethylene, polypropylene, polybutylene, and polyisobutylene, an ethylene-propylene-based copolymer, and ethylene-ethyl. Copolymers containing an olefin-based monomer such as an acrylate copolymer are exemplified. Suitable polyolefin resins for the present invention are low crystalline polypropylene and ethylene-propylene copolymers.

The phosphoric ester flame retardant which is the component (D) of the present invention is not particularly limited. For example, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, xylenyl Aromatic phosphoric ester flame retardants such as diphenyl phosphate, dixylenyl phenyl phosphate, hydroquinone bisphosphate, resorcinol bisphosphate and bisphenol A bisphosphate are more suitable, and they may be used alone or in combination of two or more. A particularly suitable aromatic phosphate ester flame retardant for the present invention is triphenyl phosphate. Triphenyl phosphate has a superior flame retardant effect compared to other aromatic phosphate ester flame retardants.

In the present invention, the added amount of the polyphenylene ether resin or the polystyrene resin as the component (A) is selected from the range of 40 to 90 parts by weight.
If the amount of component (A) exceeds 90 parts by weight, it is not preferable because components (B) and (C) sufficient to impart vibration damping properties cannot be added. In the present invention,
The added amount of the block copolymer as the component (B) is from 5 to 35.
It is selected from the range of parts by weight. If the addition amount of the component (B) is less than 5 parts by weight, a sufficient vibration damping effect cannot be obtained, which is not preferable. This is not preferable because the product is easily delaminated.

In the present invention, the addition amount of the polyolefin resin as the component (C) is selected from the range of 0 to 20 parts by weight, more preferably 3 to 15 parts by weight.
If the addition amount of the component (C) exceeds 20 parts by weight, it is not preferable because the flame retardant by the phosphoric ester-based flame retardant in the molded product cannot be obtained and the molded product is easily delaminated.

In the present invention, the addition amount of the phosphoric ester-based flame retardant as the component (D) is selected from the range of 0 to 30 parts by weight, more preferably 5 to 25 parts by weight, particularly preferably 10 to 20 parts by weight. Range. However, in the case of flame retardation, the addition amount of the component (D) needs to be 5 parts by weight or more. When the amount is less than 5 parts by weight, the flame retarding effect becomes insufficient, and when it exceeds 30 parts by weight, the heat resistance of the composition is unpreferably decreased.

Various additives can be added to the resin composition of the present invention, if necessary. In order to increase rigidity and dimensional performance, an inorganic filler is added at an arbitrary ratio.
In the case of blending an inorganic filler, it is particularly preferable to use a flaky filler such as glass flake, mica, flaky talc, or flaky graphite because the vibration damping property is improved. Antioxidant to increase the stability of the resin composition, ultraviolet absorber,
Stabilizers such as heat stabilizers, coloring agents, release agents, and the like can also be added.

The method for preparing the composition of the present invention is not particularly limited, but an extruder is generally used to control the dispersed particle diameter. It is easiest to control the dispersed particle size by the shear stress during extrusion. The shear stress at the time of extrusion can be changed by the extrusion temperature, screw pattern, screw rotation speed, and the like.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on examples, but the present invention is not limited to these examples. The parts used below are parts by weight and% is% by weight. The block copolymers used in Examples and Comparative Examples are shown below.

(1) B-1 The structure of hydrogenated polybutadiene-polystyrene obtained by random copolymerization of polystyrene-styrene, the total content of bound styrene is 54%, and the amount of block styrene is 20
%, Total vinyl bond content of the random copolymer block 41
%, A block copolymer having a number average molecular weight of 120,000 in terms of polystyrene and a hydrogenation ratio of the polybutadiene portion of 90% or more was synthesized and designated as B-1.

(2) B-2 having a structure of hydrogenated polybutadiene-polystyrene obtained by random copolymerization of polystyrene-styrene, having a total bound styrene content of 56% and a block styrene content of 21
%, Total vinyl bond content of random copolymer block 40
%, A block copolymer having a number average molecular weight of 70,000 in terms of polystyrene and a hydrogenation ratio of the polybutadiene portion of 90% or more was synthesized, and this was designated as B-2.

(3) B-3 having a structure of hydrogenated polybutadiene-polystyrene obtained by random copolymerization of polystyrene-styrene, having a total bound styrene content of 52% and a block styrene content of 12
%, Total vinyl bond content of the random copolymer block 41
%, A block copolymer having a number average molecular weight of 210,000 in terms of polystyrene and a hydrogenation ratio of the polybutadiene portion of 90% or more was synthesized, and this was designated as B-3.

(4) B-4 The structure of hydrogenated polybutadiene-polystyrene obtained by random copolymerization of polystyrene-styrene, the total bound styrene content is 43%, and the block styrene content is 18
%, Total vinyl bond content of random copolymer block 40
%, A block copolymer having a number average molecular weight of 100,000 in terms of polystyrene and a hydrogenation ratio of the polybutadiene portion of 90% or more was synthesized, and this was designated as B-4.

(5) Hibler 7125 (manufactured by Kuraray Co., Ltd.) Polystyrene-hydrogenated polyisoprene-polystyrene structure, block styrene content 20%, vinyl bond content 55%, polystyrene reduced number average molecular weight 10
4,000, hydrogenation rate 85%.

The measured values in the examples and comparative examples were obtained by the following methods. (1) Tan δ characteristics A viscoelastic spectrum was measured using Leo Vibron manufactured by Orientec, and the tan δ at a peak temperature and 23 ° C. was measured.
The value was determined. (2) Average particle diameter of dispersed phase An electron micrograph of an ultrathin section of the resin composition is taken, the arithmetic mean of the major axis and minor axis of the dispersed phase particles is defined as the particle diameter, and the average is calculated from about 500 dispersed phase particles. Was.

(3) Vibration Suppression Property (Loss Coefficient η) Using a two-channel fast Fourier transform apparatus, measurement was performed by the cantilever method by non-contact random excitation, and the result was expressed in%. The measurement temperature is 23 ° C. (4) Flammability A 1.6 mm thick test piece was measured based on the UL-94 test method. (5) Bending strength and flexural modulus A three-point bending test was performed at 23 ° C. based on a bending test method according to ASTM D790 and measured.

[0040]

Comparative Example 1 Poly (2,6-dimethyl-) having an intrinsic viscosity of 0.43 dl / g (measured in a chloroform solvent at 30 ° C.)
40 parts of 1,4-phenylene) ether, 55 parts of polystyrene 685 from Asahi Kasei Corporation, 5 parts of block copolymer B-1 and 2,6-di-tert-butyl-
PC of Ikegai Iron Works Co., Ltd. with 1 part of 4-methylphenol
Using an M30 twin screw extruder, kneading disc L:
2 pieces, kneading disc R: 3 pieces, sealing: 1
Screw pattern with a cylinder temperature of 30
The resin composition was obtained by melt-kneading at 0 ° C. and a screw rotation speed of 100 rpm. Table 1 shows the physical property test results of the composition.

[0041]

Example 1 A resin composition was obtained by repeating Comparative Example 1 in which 15 parts of polystyrene were changed to B-1. Table 1 shows the physical property test results of the composition.

[0042]

Example 2 A resin composition was obtained by repeating Example 1 except that 10 parts of polystyrene and 5 parts of B-1 were replaced with polypropylene SA510 of Nippon Polyolefin Co., Ltd. Table 1 shows the physical property test results of the composition.

[0043]

Comparative Example 2 The poly (2,6-dimethyl-1,1) of Comparative Example 1
45 parts of 4-phenylene) ether, 40 parts of B-1, 15 parts of triphenyl phosphate and 2,6-di-te
Comparative Example 1 with 1 part of rt-butyl-4-methylphenol
The resin composition was obtained by melt-kneading under the same extrusion conditions as described above. Table 2 shows the physical property test results of the composition.

[0044]

Comparative Example 3 A resin composition was obtained by repeating Comparative Example 2 by replacing 20 parts of B-1 with polystyrene of Comparative Example 1, and further replacing 20 parts with B-4. Table 2 shows the physical property test results of the composition.

[0045]

Example 3 A resin composition was obtained by repeating Comparative Example 2 by replacing 20 parts of B-1 with polystyrene of Comparative Example 1.
Table 2 shows the physical property test results of the composition.

[0046]

Example 4 A resin composition was obtained by repeating Example 3 by replacing B-1 with B-2. Table 2 shows the physical property test results of the composition.
Shown in

[0047]

Example 5 A resin composition was obtained by repeating Example 3 except that B-1 was replaced with B-3. Table 2 shows the physical property test results of the composition.
Shown in

[0048]

Comparative Example 4 A resin composition was obtained by repeating Comparative Example 2 except that 25 parts of B-1 were replaced with the polypropylene of Example 2. Table 3 shows the physical property test results of the composition.

[0049]

Comparative Example 5 A resin composition was obtained by repeating Comparative Example 4 by replacing 10 parts of polypropylene with polystyrene of Comparative Example 1, and further replacing B-1 with B-4. Table 3 shows the physical property test results of the composition.

[0050]

Example 6 A resin composition was obtained by repeating Comparative Example 4 with the exception that 10 parts of polypropylene were replaced with the polystyrene of Comparative Example 1. Table 3 shows the physical property test results of the composition.

[0051]

Example 7 A resin composition was obtained by repeating Example 6 by replacing B-1 with B-3. Table 3 shows the physical property test results of the composition.
Shown in

[0052]

Comparative Example 6 The poly (2,6-dimethyl-1,1) of Example 1
4-phenylene) ether 28 parts, polystyrene 685
15 parts, 9 parts of Hybler 7125, 8 parts of triphenyl phosphate, and glass flakes 40 having a thickness of 3 to 7 μm.
And 1 part of 2,6-di-tert-butyl-4-methylphenol were melt-kneaded under the extrusion conditions of Comparative Example 1 to obtain a resin composition. Table 4 shows the physical property test results of the composition.

[0053]

Example 8 A resin composition was obtained by repeating Comparative Example 6 with the exception that the high blur 7125 was changed to B-1. Table 4 shows the physical property test results of the composition.

[0054]

[Table 1]

[0055]

[Table 2]

[0056]

[Table 3]

[0057]

[Table 4]

[0058]

The resin composition of the present invention contains a polyphenylene ether resin, a block copolymer, a polyolefin resin and / or a phosphoric ester-based flame retardant, and has a rigid structure by using a block copolymer having a specific structure. It is a polyphenylene ether resin composition having excellent flame damping properties of flame-retardant and non-flame-retardant with little decrease.

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Claims (2)

[Claims] 1. A polyphenylene ether resin or 40 to 90 parts by weight of a polystyrene resin and a polyphenylene ether resin,
It is composed of a polymer block of a styrene compound and a random copolymer block of butadiene and a styrene compound having a total content of vinyl bonds of 20% by weight or more. The occupying ratio is 30 to 60% by weight, and the styrene-based compound polymer block accounts for 8 to 50% by weight of the whole component.
Block copolymer resin in the range of 0.00000 to 5 to 35
Parts by weight, (C) 0 to 20 parts by weight of a polyolefin resin and (D) 0 to 30 parts by weight of a phosphate ester-based flame retardant, and the components (B) and (C) form a dispersed phase, and are dispersed particles. Has a mean diameter in the range of 0.2 to 4 μm. 2. The resin composition according to claim 1, wherein the butadiene portion of the random copolymer block of the component (B) is hydrogenated by 70% or more.