JPH11323069A - Gasket material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a gasket materialhaving excellent steam permeation resistance, gas permeation resistance, heat resistance, weather resistance, etc., usable in a wide temperature range, readily recyclable, useful for civil engineering and construction and useful as an automobile part, etc., by including a specific isobutylene-based block copolymer. SOLUTION: The gasket material comprises an isobutylene-based block copolymer composed of (A) a polymer block consisting essentially of isobutylene and (B) a polymer block composed of a monomer component such as styrene or the like not consisting essentially of isobuthylene in the ratio of preferably 15-40 wt.% of the component B and 85-60 wt.% of the component A. The copolymer is a triblock copolymer constituted of the components B-A-B, a diblock copolymer constituted of the components B-A, a star type block copolymer having >=3 arms constituted of the components B-A or their mixture and has preferably 50,000-400,000 number-average molecular weight.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a water vapor permeation resistance,
The present invention relates to a gasket material which has excellent properties such as gas permeability, heat resistance, weather resistance, can be used in a wide temperature range, and is easy to recycle.

[0002]

2. Description of the Related Art In recent years, in the field of civil engineering of houses and the like, the field of construction, the field of machinery, the field of transportation of automobiles, ships, aircraft, etc., or the field of electricity and electronics, techniques for sealing liquids and gases, and techniques for absorbing vibration, noise and shock. Development is required. Conventionally, various gasket materials have been developed for such purposes, but molding workability, weather resistance, heat resistance, chemical resistance, water vapor transmission resistance, gas transmission resistance, vibration absorption, None of the materials had various properties required for gasket materials such as insulating properties. JP-A-8-127683 discloses that
There is disclosed a gasket material comprising a saturated hydrocarbon polymer having an alkenyl group, a curing agent having a hydrosilyl group, a hydrosilylation catalyst, and fine silica powder. The gasket material obtained by this method is easy to process because it cures a so-called liquid rubber, and also satisfies the above-mentioned various properties in terms of performance, but because it is a thermosetting material, However, there is a problem that the recyclability is poor.

[0003]

The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, a gasket material comprising a specific block copolymer can overcome the above-mentioned problems. The present invention was found to be excellent in various properties such as water vapor transmission resistance, gas transmission resistance, heat resistance, weather resistance, etc., usable in a wide temperature range, and easy to recycle, and completed the present invention. That is, the present invention relates to a gasket material comprising an isobutylene-based block copolymer having a polymer block composed mainly of isobutylene and a polymer block composed of a monomer component not composed mainly of isobutylene.

In a preferred embodiment, the gasket material is for civil engineering and construction. In a preferred embodiment, the gasket material is for automotive parts. In a preferred embodiment, the block copolymer is a polymer block composed of a monomer component not containing isobutylene as a main component-a polymer block containing isobutylene as a main component-a monomer block containing no isobutylene as a main component. Diblock copolymer composed of a polymer block composed of a polymer block composed mainly of isobutylene and triblock composed of a polymer block composed mainly of isobutylene, and a monoblock composed of a polymer block composed of a polymer block composed mainly of isobutylene. A star block copolymer having three or more arms composed of a polymer block composed of a monomer component and a polymer block composed mainly of isobutylene, or a mixture thereof.

[0005] In a preferred embodiment, the block copolymer comprises monomers 5 to 8 which are not based on isobutylene.
It is a block copolymer consisting of 0% by weight and 95 to 20% by weight of a monomer mainly composed of isobutylene. In a preferred embodiment, the block copolymer is a block copolymer composed of 15 to 40% by weight of a monomer containing no isobutylene as a main component and 85 to 60% by weight of a monomer mainly containing isobutylene. .

[0006] In a preferred embodiment, the number average molecular weight of the block copolymer is 30,000 to 500,000. In a preferred embodiment, the block copolymer has a number average molecular weight of 50,000 to 400,000. In a preferred embodiment, the monomer having no isobutylene as a main component has an aromatic vinyl monomer as a main component.

In a preferred embodiment, the monomer which is not based on isobutylene is based on styrene. In a preferred embodiment, the monomer containing no isobutylene as a main component contains at least one selected from the group consisting of α-methylstyrene, p-methylstyrene, vinylnaphthalene derivatives, and indene derivatives.

In a preferred embodiment, the non-isobutylene-based monomer comprises a mixture of α-methylstyrene and / or indene and styrene. In a preferred embodiment, a filler is further included. In a preferred embodiment, the composition further comprises a polyolefin-based resin and, if necessary, a process oil and / or a filler and / or a stabilizer.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The present invention relates to a gasket material comprising an isobutylene-based block copolymer having a polymer block containing isobutylene as a main component and a polymer block containing a monomer component not containing isobutylene as a main component.

The isobutylene block copolymer of the present invention is not particularly limited as long as it has a polymer block containing isobutylene as a main component and a polymer block containing a monomer component not containing isobutylene as a main component. However, for example, any of block copolymers, diblock copolymers, triblock copolymers, and multiblock copolymers having a linear, branched, or star-like structure can be selected. As a preferable block copolymer, from the viewpoint of physical properties balance, a polymer block composed of a monomer component not containing isobutylene as a main component-a polymer block containing isobutylene as a main component-from a monomer component not containing isobutylene as a main component Triblock copolymer consisting of a polymer block consisting of, a polymer block consisting of a monomer component not containing isobutylene as a main component-a diblock copolymer consisting of a polymer block containing isobutylene as a main component, isobutylene as a main component And a star block copolymer having three or more arms composed of a polymer block composed of a monomer component not containing and a polymer block composed mainly of isobutylene. These can be used alone or in combination of two or more in order to obtain desired physical properties and moldability.

The monomer component containing no isobutylene as the main component of the present invention means a monomer component having an isobutylene content of 30% by weight or less. The content of isobutylene in the monomer component containing no isobutylene as a main component is preferably 10% by weight or less, and more preferably 3% by weight or less. The monomer other than isobutylene in the monomer component not containing isobutylene as the main component of the present invention is not particularly limited as long as it is a monomer component capable of cationic polymerization, but is not limited to aliphatic olefins, aromatic vinyls, Examples include monomers such as dienes, vinyl ethers, silanes, vinyl carbazole, β-pinene, acenaphthylene and the like. These are used alone or in combination of two or more.

Examples of the aliphatic olefin monomer include ethylene, propylene, 1-butene, 2-methyl-1-butene, 3-methyl-1-butene, pentene, hexene, cyclohexene and 4-methyl-1-pentene. , Vinylcyclohexane, octene, norbornene and the like.
Styrene, o-, m-
Or p-methylstyrene, α-methylstyrene, β-methylstyrene, 2,6-dimethylstyrene, 2,4-dimethylstyrene, α-methyl-o-methylstyrene, α
-Methyl-m-methylstyrene, α-methyl-p-methylstyrene, β-methyl-o-methylstyrene, β-methyl-m-methylstyrene, β-methyl-p-methylstyrene, 2,4,6- Trimethylstyrene, α-methyl-2,6-dimethylstyrene, α-methyl-2,4-dimethylstyrene, β-methyl-2,6-dimethylstyrene, β-methyl-2,4-dimethylstyrene, o-, m
-Or p-chlorostyrene, 2,6-dichlorostyrene, 2,4-dichlorostyrene, α-chloro-o-chlorostyrene, α-chloro-m-chlorostyrene, α-chloro-p-chlorostyrene, β- Chloro-o-chlorostyrene, β-chloro-m-chlorostyrene, β-chloro-p-chlorostyrene, 2,4,6-trichlorostyrene, α-chloro-2,6-dichlorostyrene, α-chloro-2 , 4-Dichlorostyrene, β-chloro-2,6-
Dichlorostyrene, β-chloro-2,4-dichlorostyrene, o-, m- or pt-butylstyrene, o-,
m- or p-methoxystyrene, o-, m- or p-chloromethylstyrene, o-, m- or p-bromomethylstyrene, a styrene derivative substituted with a silyl group, indene, vinylnaphthalene and the like.

Examples of the diene monomer include butadiene, isoprene, hexadiene, cyclopentadiene, cyclohexadiene, dicyclopentadiene, divinylbenzene and ethylidene norbornene. Examples of the vinyl ether monomer include methyl vinyl ether, ethyl vinyl ether, (n-, iso) propyl vinyl ether, (n-, sec-, tert-, iso) butyl vinyl ether, methyl propenyl ether, ethyl propenyl ether, and the like.

Examples of the silane compound include vinyltrichlorosilane, vinylmethyldichlorosilane, vinyldimethylchlorosilane, vinyldimethylmethoxysilane, vinyltrimethylsilane, divinyldichlorosilane, divinyldimethoxysilane, divinyldimethylsilane, 1,3-
Examples thereof include divinyl-1,1,3,3-tetramethyldisiloxane, trivinylmethylsilane, γ-methacryloyloxypropyltrimethoxysilane, and γ-methacryloyloxypropylmethyldimethoxysilane.
The monomer component not containing isobutylene as a main component of the present invention,
From the balance of physical properties and polymerization characteristics, it is preferable that the monomer component is mainly composed of an aromatic vinyl monomer.
Further, styrene, α-
It is preferable to use one or more monomers selected from the group consisting of methylstyrene, p-methylstyrene, vinylnaphthalene derivatives, and indene derivatives, and in terms of cost, styrene, α-methylstyrene, indene, or a mixture thereof. It is particularly preferred to use

The monomer component containing isobutylene as the main component of the present invention represents a monomer component containing 50% by weight or more, preferably 80% by weight or more, more preferably 90% by weight or more of isobutylene. It may or may not contain other monomers. The monomer other than isobutylene is not particularly limited as long as it is a monomer capable of cationic polymerization, and examples thereof include the above-mentioned monomers.

The ratio of the polymer block containing isobutylene as a main component and the polymer block containing a monomer component not containing isobutylene as a main component is not particularly limited.
From the viewpoint of various physical properties, the polymer block composed of a monomer component containing no isobutylene as a main component is 5 to 80% by weight, and the polymer block mainly containing isobutylene is 95 to 2% by weight.
It is preferably 0% by weight, and 15 to 40% by weight of a polymer block composed of a monomer component not containing isobutylene as a main component, and 85 to 60% by weight of a polymer block containing isobutylene as a main component. Particularly preferred.

The number average molecular weight of the isobutylene-based block copolymer is not particularly limited, but is preferably 30,000 to 500,000, and more preferably 50,000 to 400,000 in view of fluidity, processability, physical properties and the like. Particularly preferred. If the number average molecular weight of the isobutylene-based block copolymer is lower than the above range, mechanical properties may not be sufficiently exhibited, while if it exceeds the above range, it is disadvantageous in terms of fluidity and processability. It is.

Regarding the method for producing the block copolymer,
Although not particularly limited, for example, it is obtained by polymerizing a monomer containing isobutylene as a main component and a monomer not containing isobutylene as a main component in the presence of a compound represented by the following general formula (I). (R ¹ R ² X) nR ³ (I) (wherein R ¹ and R ² are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms; R ³ is X is a polyvalent aromatic hydrocarbon group or a polyvalent aliphatic hydrocarbon group;
Is a substituent selected from a halogen atom, an alkoxy group having 1 to 6 carbon atoms or an acyloxy group; and n represents a natural number of 1 to 6. As specific examples of the compound represented by the general formula (I),
(1-chloro-1-methylethyl) benzene, 1,4-
Bis (1-chloro-1-methylethyl) benzene, 1,
3-bis (1-chloro-1-methylethyl) benzene,
1,3,5-tris (1-chloro-1-methylethyl)
Benzene and 1,3-bis (1-chloro-1-methylethyl) -5- (tert-butyl) benzene are exemplified. Bis (1-chloro-1-methylethyl) benzene is also called bis (α-chloroisopropyl) benzene, bis (2-chloro-2-propyl) benzene, or dicumyl chloride.

Among these, in terms of reactivity and availability,
Bis (1-chloro-1-methylethyl) benzene is particularly preferred. In the present invention, first, a monomer having isobutylene as a main component is polymerized in the presence of the compound represented by the general formula (I), and an isobutylene-based polymer having a substituent (X) at a terminal is provided. After isolating and purifying this, a monomer not containing isobutylene as a main component is polymerized,
A block copolymer can also be synthesized.

Further, if necessary, a Lewis acid catalyst may coexist. Such a Lewis acid may be any as long as it can be used for cationic polymerization.
iBr4, BCl3, BF3, BF3.OEt2, SnCl4, Sb
Cl5, SbF5, WCl6, TaCl5, VCl5, FeCl3,
Metal halides such as ZnBr2, AlCl3 and AlBr3; and organic metal halides such as Et2AlCl and EtAlCl2 can be suitably used. Above all, considering the ability as a catalyst and the industrial availability, TiC
I4, BCl3 and SnCl4 are preferred. The central metal of the Lewis acid catalyst may be the same as or different from the central metal of the metal compound, but the same metal atom is preferred in terms of post-polymerization treatment. In the present invention, the Lewis acid is usually used in a range of 0.1 to 100 times by mol with respect to the compound represented by the above general formula (I), but a preferable use amount is 0.3 to 50 times by mol. Range.

Further, if necessary, an electron donor component can be present in the polymerization system. In the present invention, the electron donor component has a donor number of 15 to 60. Conventionally known ones can be widely used. Preferred electron donor components include, for example, pyridines, amines, amides, sulfoxides, and metal compounds having an oxygen atom bonded to a metal atom.

Further, if necessary, the polymerization reaction can be carried out in a solvent, and such a solvent is not particularly limited as long as it does not substantially inhibit cationic polymerization, and any solvent can be used. . Specifically, methyl chloride,
Halogenated hydrocarbons such as dichloromethane, n-propyl chloride, n-butyl chloride and chlorobenzene;
Alkylbenzenes such as benzene, toluene, xylene, ethylbenzene, propylbenzene, and butylbenzene; ethane, propane, butane, pentane, hexane,
Linear aliphatic hydrocarbons such as heptane, octane, nonane, and decane; 2-methylpropane, 2-methylbutane,
Branched aliphatic hydrocarbons such as 2,3,3-trimethylpentane and 2,2,5-trimethylhexane; cycloaliphatic hydrocarbons such as cyclohexane, methylcyclohexane and ethylcyclohexane; hydrogenated petroleum fractions Refined paraffin oil and the like can be mentioned.

These solvents are used alone or in combination of two or more in consideration of the balance between the polymerization characteristics of the monomers constituting the block copolymer and the solubility of the resulting polymer. The amount of each component used can be appropriately designed depending on the properties of the target polymer. First, the molecular weight of the obtained polymer can be determined from the molar equivalent relationship between the isobutylene-based monomer and a cationic polymerizable monomer different from isobutylene and the compound represented by the general formula (I). Usually, the number average molecular weight of the obtained block copolymer is 20,0.
It is set to be about 00 to 500,000.

In the production method of the present invention, in carrying out actual polymerization, each component is mixed under cooling, for example, at a temperature of -100 ° C. or more and less than 0 ° C. In order to balance the energy cost with the stability of the polymerization, a particularly preferred temperature range is -80C to -30C. When producing the block copolymer, the addition method and order of the Lewis acid, the compound represented by the general formula (I), the electron donor component, the monomer component, and the like are not particularly limited, As a preferable method, for example, (A) an initiator system comprising a compound represented by the general formula (I) and a Lewis acid, and a monomer containing isobutylene as a main component in the presence of an electron donor component are polymerized. (B), and then a step of adding a monomer not containing isobutylene as a main component to the reaction system and polymerizing the same. In this case, the polymer may be once isolated and purified after the step (A), or the step (B) may be continuously performed without isolation. Additives can be added to the gasket material of the present invention as needed as long as the performance is not impaired.

Examples of the additives include stabilizers such as antioxidants and ultraviolet absorbers, lubricants, plasticizers, dyes, pigments, flame retardants, fillers, reinforcing materials, tackifiers, and other auxiliaries. Can be In particular, various fillers and reinforcing materials can be used for the purpose of improving the performance such as the strength of the gasket material.

Examples of the filler and reinforcing material include glass fiber, carbon black, flake graphite, carbon fiber, calcium sulfate, calcium carbonate, calcium silicate, alumina, silica, titanium oxide, talc, mica and the like. Examples of the stabilizer include antioxidants such as hindered phenols, phosphate esters, and amines, and ultraviolet absorbers such as benzothiazole, benzotriazole, and benzophenone. As a tackifier,
Known materials such as polybutene resin, rosin resin (rosin, rosin ester or hydrogenated rosin), phenol resin, terpene phenol resin, xylene resin, aliphatic petroleum resin, terpene resin, and cumarone resin can be used.
Further, the gasket material of the present invention can be used by adding a polyolefin resin and, if necessary, a process oil and / or a filler and / or a stabilizer. Here, as the polyolefin resin, a homopolymer of α-olefin, a random copolymer, a block copolymer and a mixture thereof, or a random copolymer of α-olefin and another unsaturated monomer, Block copolymers, graft copolymers and oxidized, halogenated or sulfonated products of these polymers can be used alone or in combination of two or more. Specifically, polyethylene, ethylene-propylene copolymer, ethylene-propylene-non-conjugated diene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer, ethylene-vinyl acetate Copolymer, ethylene-vinyl alcohol copolymer, ethylene-ethyl acrylate copolymer, polyethylene resin such as chlorinated polyethylene,
Polypropylene, propylene-ethylene random copolymer, propylene-ethylene block copolymer, polypropylene resin such as chlorinated polypropylene, polybutene,
Examples thereof include polyisobutylene, polymethylpentene, and a (co) polymer of a cyclic olefin. Among these, a polyethylene resin, a polypropylene resin, or a mixture thereof can be preferably used from the viewpoint of cost and balance of physical properties of the thermoplastic resin. As the filler, those described above can be suitably used. The process oil used in the present invention is not particularly limited, but usually, a liquid or liquid material at room temperature is suitably used. Specific examples include process oils for various rubbers or resins, such as mineral oils, vegetable oils, and synthetic oils. Mineral oils include naphthenic and paraffinic process oils, and vegetable oils include
Castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, coconut oil, peanut oil, wood wax, pine oil, olive oil, etc., and polybutene, low molecular weight polybutadiene, etc. can be exemplified as synthetic systems. Among these, a paraffin-based process oil or polybutene is preferably used in terms of compatibility and physical property balance. These can be used in appropriate combination of two or more kinds in order to obtain desired physical properties. The gasket material of the present invention can be prepared by a known method. For example, the isobutylene-based block copolymer and various compounding agents can be mixed with a tumbler, a mixer, a blender, or the like, and kneaded with a screw extruder, a roll, or the like.

The gasket material obtained in the present invention can be formed by a known method, for example, injection molding, extrusion molding, compression molding, calender molding or the like. The gasket material obtained by the present invention can be used in the fields of civil engineering, construction, and automobile, but is not limited thereto.

[0028]

The present invention will be described more specifically with reference to the following examples. It should be noted that the present invention is not limited in any way by these embodiments, and can be appropriately changed and implemented without changing the gist thereof. The molecular weight of the block copolymer and the properties of the gasket material were measured by the following methods. (1) Molecular weight GPC system manufactured by Waters (column: Shodex K-804 (polystyrene gel) manufactured by Showa Denko KK, mobile phase: chloroform). The number average molecular weight was expressed in terms of polystyrene. (2) Heat Stability A molded article to be a test piece was prepared by compression molding, and the test piece was left in a hot-air oven set at 120 ° C. 7
After a day, the test piece was taken out and the state of deterioration was visually observed.

Heat stability ：: No change Heat stability △: Slight coloring and deformation of test piece are observed Heat stability X: Coloring and deformation are remarkable (3) Mechanical strength JIS No. 3 dumbbell test piece by compression molding It was created. According to JIS K6251, a tensile speed of 500 mm /
The breaking strength was measured in sec. (4) Water vapor transmission coefficient A sample of about 1 mm thickness was prepared by compression molding, and JI
According to SZ 0208, the permeability coefficient of oxygen at 40 ° C. and 90% RH was measured. (5) Oxygen Permeability Coefficient About 1 mm thick sample was prepared by compression molding,
The permeability coefficient of oxygen at 23 ° C. was measured according to SK 7126. Production Example 1 Production Example of Isobutylene Block Copolymer In a 10 L reaction vessel equipped with a stirrer, 2166 m of methylcyclohexane (dried with molecular sieves) was added.
L, methylene chloride (dried with molecular sieves) 1,634 mL, p-dicumyl chloride 1.756
g was added. After cooling the reaction vessel to −70 ° C., 0.75 mL of α-picoline (2-methylpyridine) and 633 mL of isobutylene were added. 30m titanium tetrachloride
L was added to start polymerization, and the mixture was reacted at -70 ° C for 1.5 hours while stirring the solution. Then, styrene 2 was added to the reaction solution.
After adding 70 mL and continuing the reaction for further 20 minutes, a large amount of methanol was added to stop the reaction. After removing the solvent and the like from the reaction solution, the polymer was dissolved in toluene and washed twice with water. This toluene solution was added to an acetone-methanol mixture to precipitate a polymer, and the obtained polymer was vacuum-dried at 60 ° C. for 24 hours to obtain an isobutylene-based block copolymer (hereinafter abbreviated as SIBS). The obtained isobutylene-based block copolymer (SI
GPC analysis of BS) revealed that the number average molecular weight was 1
02,000, molecular weight distribution was 1.15. The styrene content was 29% by weight. Example 1 The heat stability, mechanical properties, water vapor permeability coefficient, and oxygen permeability coefficient of the isobutylene-based block copolymer obtained in Production Example 1 were measured. Table 1 shows the results. Comparative Example 1 A commercially available styrene-ethylene butylene block copolymer (SEBS, Kraton G1650 manufactured by Shell Chemical Co., Ltd.) was dissolved in toluene and purified by dropping in isopropyl alcohol to obtain heat stability, mechanical properties, water vapor permeability coefficient, The oxygen permeability coefficient was evaluated. Table 1 shows the results. Example 2 A gasket material was produced using the following raw materials.

100 parts by weight of the isobutylene-based block copolymer (SIBS) obtained in Production Example 1, 50 parts by weight of polypropylene (propylene-ethylene block copolymer, Grand Polypro J705, manufactured by Grand Polymer),
Paraffin-based process oil (Diana Process PW-
380, 100 parts by weight of Idemitsu Kosan Co., Ltd., and 0.5 parts by weight of an antioxidant (Irganox 1010, manufactured by Ciba Geigy) were melt-kneaded using a Labo Plastomill (manufactured by Toyo Seiki Co., Ltd.) set at 170 ° C. A test piece was prepared by compression molding the obtained composition, and various physical properties were evaluated. Table 1 shows the evaluation results. As is evident from Table 1, the gasket materials obtained in the examples are excellent in heat stability, mechanical properties, water vapor permeability, and gas permeability.

[0031]

[Table 1]

[0032]

According to the present invention, a gasket material which is excellent in various properties such as water vapor permeability, gas permeability resistance, heat resistance, weather resistance, etc., can be used in a wide temperature range, and is easy to recycle is obtained. Can be

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // E04B 1/684 F02F 11/00 N F02F 11/00 E04B 1/68 D (C08L 53/00 23:00) (C08L 53 / 00 51:06) (C08L 53/00 23:00 91:00) (C08L 53/00 51:06 91:00) (C08L 53/00 91:00)

Claims (14)

[Claims] 1. A gasket material comprising an isobutylene-based block copolymer having a polymer block composed mainly of isobutylene and a polymer block composed of a monomer component not composed mainly of isobutylene. 2. The gasket material according to claim 1, wherein the gasket material is for civil engineering and construction. 3. The gasket material according to claim 1, wherein the gasket material is for an automobile part. 4. A block copolymer comprising a polymer block composed of a monomer component not containing isobutylene as a main component and a polymer block composed of a polymer block containing isobutylene as a main component and a polymer block containing a monomer component not containing isobutylene as a main component. Triblock composed of coalesced blocks, polymer block composed of monomer components not containing isobutylene as a main component-diblock copolymer composed of polymer blocks containing isobutylene as a main component, monomer not containing isobutylene as a main component The gasket material according to claim 1, wherein the gasket material is a star block copolymer having three or more arms composed of a polymer block composed of components and a polymer block composed mainly of isobutylene, or a mixture thereof. 5. A block copolymer comprising 5 to 80% by weight of a monomer not containing isobutylene as a main component and 95 to 20% by weight of a monomer containing isobutylene as a main component. Item 2. The gasket material according to Item 1. 6. The block copolymer comprising 15 to 40% by weight of a monomer not containing isobutylene as a main component and 85 to 60% by weight of a monomer containing isobutylene as a main component. Item 2. The gasket material according to Item 1. 7. The block copolymer has a number average molecular weight of 30.
2. The gasket material according to claim 1, wherein the gasket material is between 000 and 500,000. 8. The number average molecular weight of the block copolymer is 50.
The gasket material according to claim 1, wherein the gasket material is between 000 and 400,000. 9. The gasket material according to claim 1, wherein the monomer not containing isobutylene as a main component contains an aromatic vinyl monomer as a main component. 10. The gasket material according to claim 1, wherein the monomer having no isobutylene as a main component is styrene. 11. The method according to claim 1, wherein the monomer containing no isobutylene as a main component contains at least one selected from the group consisting of α-methylstyrene, p-methylstyrene, vinylnaphthalene derivatives and indene derivatives. 1
The gasket material according to the above. 12. The gasket material according to claim 1, wherein the monomer component containing no isobutylene as a main component comprises a mixture of α-methylstyrene and / or indene and styrene. 13. The gasket material according to claim 1, further comprising a filler. 14. A polyolefin resin and, if necessary, a process oil and / or a filler and / or
The gasket material according to claim 1, further comprising a stabilizer.