JP2020015834A - Composition for bending-fatigue resistant material, crosslinked product for bending-fatigue resistant material and bending-fatigue resistant material - Google Patents

Abstract

To provide a composition for bending-fatigue resistant material that can give a bending-fatigue resistant material showing excellent bending-fatigue resistance and low friction coefficients.SOLUTION: There is provided a composition for bending-fatigue resistant material containing an inorganic material, and a ring-opening copolymer containing a monocyclic cyclic olefin-derived structural unit and a norbornene compound-derived structural unit.SELECTED DRAWING: None

Description

  The present invention relates to a composition for a bending fatigue-resistant material and a crosslinked product for a bending fatigue-resistant material, which is a bending fatigue-resistant material exhibiting excellent bending fatigue resistance and a low coefficient of friction.

Generally, a cyclopentene and a norbornene compound are a so-called Ziegler-Natta comprising a transition metal compound of Group 6 of the periodic table such as WCl ₆ or MoCl ₅ and an organic metal activator such as triisobutylaluminum, diethylaluminum chloride or tetrabutyltin. It is known that metathesis ring-opening polymerization in the presence of a catalyst gives an unsaturated linear ring-opening polymer. In addition, there is known a method for improving the affinity of a polymer for inorganic particles by introducing a functional group containing a hetero atom at a polymer chain terminal.

  For example, in Patent Literature 1, a polymer chain has a functional group containing an atom selected from the group consisting of an atom belonging to Group 15 of the periodic table, an atom belonging to Group 16 of the periodic table, and a silicon atom, and a gel. Cyclopentene ring-opened polymer having a number average molecular weight (Mn) of 10,000 to 1,000,000 in terms of polystyrene measured by permeation chromatography, inorganic particles, and cyclopentene ring-opened polymer optionally blended A polymer composition containing a rubber other than the above is disclosed.

  According to the technique of Patent Document 1, cyclopentene having a functional group containing an atom selected from the group consisting of an atom of Group 15 of the periodic table, an atom of Group 16 of the periodic table, and a silicon atom at the end of the polymer chain is used. A cyclopentene ring-opening copolymer obtained by ring-opening copolymerization is disclosed. According to the technique of Patent Document 1, although a polymer composition having improved mechanical properties and improved affinity for inorganic particles can be provided, the bending fatigue resistance is not always sufficient, and the friction coefficient is not sufficient. Therefore, it is suitable for tire applications that require wet grip and low heat build-up, but applications that require excellent flex fatigue resistance and low friction coefficient, such as rubber, hoses and electric wires for car wiper blades -Not always suitable for applications such as cable covering materials, conveyor belts and rubber screens.

JP 2013-144813 A

  The present invention has been made in view of such circumstances, and a composition for a bending fatigue-resistant material and a bending-resistant material capable of providing a bending fatigue-resistant material exhibiting excellent bending fatigue resistance and a low friction coefficient. An object of the present invention is to provide a crosslinked product for a fatigue-resistant material, and a composition for a flexural fatigue-resistant material or a flexural fatigue-resistant material obtained by using the crosslinked product for a flexural fatigue-resistant material.

  The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that an inorganic material and a bending fatigue resistance including a ring-opening copolymer containing a structural unit derived from a monocyclic olefin and a structural unit derived from a norbornene compound are used. According to the composition for a conductive material, it has been found that a bending fatigue resistant material obtained by using the composition exhibits excellent bending fatigue resistance and a low wear coefficient, and has completed the present invention.

  That is, according to the present invention, there is provided a composition for a bending fatigue-resistant material including an inorganic material and a ring-opening copolymer including a structural unit derived from a monocyclic cycloolefin and a structural unit derived from a norbornene compound.

（式中、Ｒ^１〜Ｒ^４は水素原子、炭素数１〜２０の炭化水素基、または、ハロゲン原子、ケイ素原子、酸素原子もしくは窒素原子を含む置換基を示し、Ｒ^２とＲ^３は互いに結合して環構造を形成していてもよく、ｍは０または１である。）
前記Ｒ^１〜Ｒ^４が、水素原子、炭素数１〜２０の鎖状炭化水素基、または、ハロゲン原子、ケイ素原子、酸素原子もしくは窒素原子を含む置換基であることが好ましい。
前記開環共重合体以外のゴムをさらに含むことが好ましい。 It is preferable that the inorganic material is a carbon material.
It is preferable that the norbornene compound is a norbornene compound represented by the following general formula (1).

(Wherein, R ^{1 to} R ⁴ represent a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a substituent containing a halogen atom, a silicon atom, an oxygen atom or a nitrogen atom, and R ² and R ³ are They may combine to form a ring structure, and m is 0 or 1.)
It is preferable that R ^{1 to} R ⁴ are a hydrogen atom, a chain hydrocarbon group having 1 to 20 carbon atoms, or a substituent containing a halogen atom, a silicon atom, an oxygen atom or a nitrogen atom.
It is preferable to further include a rubber other than the ring-opening copolymer.

  Further, according to the present invention, there is provided a crosslinked product for a bending fatigue resistant material obtained by crosslinking the above composition for a bending fatigue resistant material.

  Further, according to the present invention, there is provided a bending fatigue resistant material using the composition for a bending fatigue resistant material or the crosslinked product for a bending fatigue resistant material.

  According to the present invention, a composition for a flex fatigue-resistant material and a crosslinked product for a flex fatigue-resistant material, which can provide a flex fatigue-resistant material exhibiting excellent flex fatigue resistance and a low coefficient of friction, and It is possible to provide a flex fatigue resistant material obtained by using a composition for a flex fatigue resistant material or a crosslinked product for a flex fatigue resistant material.

<Composition for bending fatigue resistant material>
The composition for a bending fatigue-resistant material of the present invention contains an inorganic material and a ring-opening copolymer containing a structural unit derived from a monocyclic olefin and a structural unit derived from a norbornene compound. The composition for bending fatigue resistance material is a composition from which a material excellent in bending fatigue resistance can be obtained, and preferably, a crosslinked product showing the number of times of bending at break within a preferable numerical range described later. Refers to a composition that can provide

  The ring-opening copolymer contained in the composition for a bending fatigue-resistant material of the present invention contains a structural unit derived from a monocyclic olefin and a structural unit derived from a norbornene compound.

  The monocyclic olefin in the present invention is not particularly limited as long as it is an olefin having only one cyclic structure, and examples thereof include cyclopropene, cyclobutene, cyclopentene, methylcyclopentene, cyclohexene, methylcyclohexene, cycloheptene, and cyclooctene. Cyclic monoolefins; cyclic diolefins such as cyclohexadiene, methylcyclohexadiene, cyclooctadiene, and methylcyclooctadiene; and the like.

  As the monocyclic olefin, one kind may be used alone, or two or more kinds may be used in combination. As the monocyclic olefin, cyclopentene, cyclohexene, cycloheptene and cyclooctadiene are preferable, and cyclopentene and cyclooctadiene are more preferable from the viewpoint that the effects of the present invention can be more easily obtained.

The norbornene compound in the present invention is a compound having a norbornene ring structure, and is preferably a norbornene compound represented by the following general formula (1).

In the formula, R ^{1 to} R ⁴ represent a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a substituent containing a halogen atom, a silicon atom, an oxygen atom or a nitrogen atom, and R ² and R ³ are bonded to each other And m may be 0 or 1.

  Specific examples of the norbornene compound represented by the general formula (1) include, for example, the following compounds.

2-norbornene, 5-methyl-2-norbornene, 5-ethyl-2-norbornene, 5-butyl-2-norbornene, 5-hexyl-2-norbornene, 5-decyl-2-norbornene, 5-cyclohexyl-2- Norbornene, 5-cyclopentyl-2-norbornene, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, 5-propenyl-2-norbornene, 5-cyclohexenyl-2-norbornene, 5-cyclopentenyl-2- norbornene, 5-phenyl-2-norbornene, tetracyclo ^{[9.2.1.0 2,10.} 0 ^3,8 ] tetradeca-3,5,7,12-tetraene (also referred to as 1,4-methano-1,4,4a, 9a-tetrahydro-9H-fluorene), tetracyclo [10.2.1.0 ^{2 , 11} . 0 ^4,9] pentadeca -4,6,8,13- tetraene (1,4-methano -1,4,4a, 9, 9a, also referred to as 10-hexa hydro anthracene), dicyclopentadiene, methyl dicyclopentadiene And unsubstituted or hydrocarbon-substituted bicyclo [2.2.1] hept-2-ene such as dihydrodicyclopentadiene (tricyclo [5.2.1.0 ^2,6 ] dec-8-ene) Kind;

Tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-4-ene, 9-methyltetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-4-ene, 9-ethyltetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-4-ene, 9-cyclohexyltetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-4-ene, 9-cyclopentyltetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-4-ene, 9-methylenetetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-4-ene, 9-ethylidenetetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-4-ene, 9-vinyltetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-4-ene, 9-propenyltetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-4-ene, 9-cyclohexenyltetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-4-ene, 9-cyclopentenyltetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-4-ene, and 9-phenyltetracyclo [6.2.1.1 ^3,6 . Tetracyclo [6.2.1.1 ^3,6 ... Having unsubstituted or hydrocarbon substituents such as [0 ^2,7 ] dodec-4-ene. 0 ^2,7 ] dodec-4-enes;

Alkoxy such as methyl 5-norbornene-2-carboxylate, ethyl 5-norbornene-2-carboxylate, methyl 2-methyl-5-norbornene-2-carboxylate, ethyl 2-methyl-5-norbornene-2-carboxylate Bicyclo [2.2.1] hept-2-enes having a carbonyl group;
Tetracyclo [6.2.1.1 ^3,6 . Methyl ^0,7 ] dodec-9-en-4-carboxylate and 4-methyltetracyclo [6.2.1.1 ^3,6 . Tetracyclo [6.2.1.1 ^3,6 ... Having an alkoxycarbonyl group such as methyl [ ^2,7 ] dodec-9-en-4-carboxylate. 0 ^2,7 ] dodec-4-enes;

Bicyclo [2.2] having a hydroxycarbonyl group or an acid anhydride group such as 5-norbornene-2-carboxylic acid, 5-norbornene-2,3-dicarboxylic acid, and 5-norbornene-2,3-dicarboxylic anhydride. .1] hept-2-enes;
Tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-9-en-4-carboxylic acid, tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-9-ene-4,5-dicarboxylic acid and tetracyclo [6.2.1.1 ^3,6 . Tetracyclo [6.2.1.1 ^3,6 ... Having a hydroxycarbonyl group or an acid anhydride group such as [0 ^2,7 ] dodec-9-ene-4,5-dicarboxylic anhydride. 0 ^2,7 ] dodec-4-enes;

5-hydroxy-2-norbornene, 5-hydroxymethyl-2-norbornene, 5,6-di (hydroxymethyl) -2-norbornene, 5,5-di (hydroxymethyl) -2-norbornene, 5- (2- Bicyclo [2.2.1] hept-2-enes having a hydroxyl group such as hydroxyethoxycarbonyl) -2-norbornene and 5-methyl-5- (2-hydroxyethoxycarbonyl) -2-norbornene;
Tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-9-en-4-methanol and tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7] tetracyclo having a hydroxyl group such as dodeca-9-ene-4-ol [6.2.1.1 ^{3, 6.} 0 ^2,7 ] dodec-4-enes;

Bicyclo [2.2.1] hept-2-enes having a hydrocarbonyl group such as 5-norbornene-2-carbaldehyde;
Tetracyclo [6.2.1.1 ^3,6 . Tetracyclo [6.2.1.1 ^3,6 .. Having a hydrocarbonyl group such as [0 ^2,7 ] dodec-9-en-4-carbaldehyde. 0 ^2,7 ] dodec-4-enes;

  Bicyclo [2.2.1] hept-2-enes having an alkoxylcarbonyl group such as 3-methoxycarbonyl-5-norbornene-2-carboxylic acid and a hydroxycarbonyl group;

Bicyclo having a carbonyloxy group such as 5-norbornen-2-yl acetate, 2-methyl-5-norbornen-2-yl acetate, 5-norbornen-2-yl acrylate, and 5-norbornen-2-yl methacrylate [2.2.1] hept-2-enes;
9-tetracycloacetic acid [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-4-enyl, 9-tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-4-enyl and 9-tetracyclo [6.2.1.1 ^3,6 .methacrylate]. Tetracyclo [6.2.1.1 ^3,6 .. Having a carbonyloxy group such as [0 ^2,7 ] dodec-4-enyl. 0 ^2,7 ] dodec-4-enes;

Bicyclo [2.2.1] hept-2 having a functional group containing a nitrogen atom such as 5-norbornene-2-carbonitrile and 5-norbornene-2-carboxamide, 5-norbornene-2,3-dicarboxylic imide -Enes;
Tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-9-en-4-carbonitrile, tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-9-en-4-carboxamide and tetracyclo [6.2.1.1 ^3,6 . Tetracyclo [6.2.1.1 ^3,6 ... Having a functional group containing a nitrogen atom such as [0 ^2,7 ] dodec-9-ene-4,5-dicarboxylic imide. 0 ^2,7 ] dodec-4-enes;

Bicyclo [2.2.1] hept-2-enes having a halogen atom such as 5-chloro-2-norbornene;
9-chlorotetracyclo [6.2.1.1 ^3,6 . Tetracyclo [6.2.1.1 ^3,6 .. Having a halogen atom such as [0 ^2,7 ] dodec-4-ene. 0 ^2,7 ] dodec-4-enes;

Bicyclo [2.2.1] hept-2-enes having a functional group containing a silicon atom, such as 5-trimethoxy-2-norbornene and 5-triethoxy-2-norbornene;
4-trimethoxysilyltetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodec-9-ene, 4-triethoxysilyltetracyclo [6.2.1.1 ^3,6 . Tetracyclo [6.2.1.1 ^3,6 .. Having a functional group containing a silicon atom such as [0 ^2,7 ] dodec-9-ene. 0 ^2,7 ] dodec-4-enes;

As the norbornene compound represented by the general formula (1), a compound represented by the general formula in which m is 0 in the general formula (1) is preferable. In the general formula (1), R ^{1 to} R ⁴ may be the same or different.

In addition, among the norbornene compounds represented by the general formula (1), a bending fatigue-resistant material exhibiting more excellent bending fatigue resistance and a lower friction coefficient can be provided. is R ¹ to R ⁴ in a hydrogen atom, a chain hydrocarbon group having 1 to 20 carbon atoms or a halogen atom, a silicon atom, is preferably a substituent containing an oxygen atom or a nitrogen atom. In this case, R ^{1 to} R ⁴ are not particularly limited as long as they are not bonded to each other and do not form a ring, and may be the same or different. As R ^{1 to} R ⁴ , A hydrogen atom or an alkyl group having 1 to 3 carbon atoms is preferred. Also in this case, a compound represented by a general formula in which m is 0 is preferable.

Norbornene compounds in which R ^{1 to} R ⁴ in the above general formula (1) are a hydrogen atom, a chain hydrocarbon group having 1 to 20 carbon atoms, or a substituent containing a halogen atom, a silicon atom, an oxygen atom or a nitrogen atom. Specific examples of the following include, for example, the following compounds.

  2-norbornene, 5-methyl-2-norbornene, 5-ethyl-2-norbornene, 5-butyl-2-norbornene, 5-hexyl-2-norbornene, 5-decyl-2-norbornene, 5-ethylidene-2- Bicyclo [2.2.1] hept-2-enes having an unsubstituted or chain hydrocarbon substituent such as norbornene, 5-vinyl-2-norbornene, 5-propenyl-2-norbornene;

  Alkoxy such as methyl 5-norbornene-2-carboxylate, ethyl 5-norbornene-2-carboxylate, methyl 2-methyl-5-norbornene-2-carboxylate, ethyl 2-methyl-5-norbornene-2-carboxylate Bicyclo [2.2.1] hept-2-enes having a carbonyl group;

  Bicyclo [2.2.1] hept-2-enes having a hydroxycarbonyl group such as 5-norbornene-2-carboxylic acid and 5-norbornene-2,3-dicarboxylic acid;

  5-hydroxy-2-norbornene, 5-hydroxymethyl-2-norbornene, 5,6-di (hydroxymethyl) -2-norbornene, 5,5-di (hydroxymethyl) -2-norbornene, 5- (2- Bicyclo [2.2.1] hept-2-enes having a hydroxyl group such as hydroxyethoxycarbonyl) -2-norbornene and 5-methyl-5- (2-hydroxyethoxycarbonyl) -2-norbornene;

Bicyclo [2.2.1] hept-2-enes having a hydrocarbonyl group such as 5-norbornene-2-carbaldehyde;
Bicyclo [2.2.1] hept-2-enes having an alkoxycarbonyl group such as 3-methoxycarbonyl-5-norbornene-2-carboxylic acid and a hydroxycarbonyl group;

  Bicyclo having a carbonyloxy group such as 5-norbornen-2-yl acetate, 2-methyl-5-norbornen-2-yl acetate, 5-norbornen-2-yl acrylate, and 5-norbornen-2-yl methacrylate [2.2.1] hept-2-enes;

  Bicyclo [2.2.1] hept-2-enes having a functional group containing a nitrogen atom, such as 5-norbornene-2-carbonitrile and 5-norbornene-2-carboxamide;

  Bicyclo [2.2.1] hept-2-enes having a halogen atom such as 5-chloro-2-norbornene;

  Bicyclo [2.2.1] hept-2-enes having a functional group containing a silicon atom, such as 5-trimethoxy-2-norbornene and 5-triethoxy-2-norbornene;

Norbornene compounds in which R ^{1 to} R ⁴ in the above general formula (1) are a hydrogen atom, a chain hydrocarbon group having 1 to 20 carbon atoms, or a substituent containing a halogen atom, a silicon atom, an oxygen atom or a nitrogen atom. Are preferably unsubstituted or hydrocarbon-substituted bicyclo [2.2.1] hept-2-enes, among which 2-norbornene, 5-methyl-2-norbornene, 5-ethyl-2-ene Norbornene, 5-ethylidene-2-norbornene and 5-vinyl-2-norbornene are more preferred, and from the viewpoint that the effects of the present invention are more easily obtained, 2-norbornene, 5-methyl-2-norbornene and 5-ethyl- 2-norbornene is more preferred.

When a compound in which R ² and R ³ are bonded to each other to form a ring is used as the norbornene compound represented by the general formula (1), a specific example of the ring structure is a cyclopentane ring , A cyclopentene ring, a cyclohexane ring, a cyclohexene ring, a benzene ring, and the like, which may form a polycyclic structure, and may further have a substituent. Among these, a cyclopentane ring, a cyclopentene ring and a benzene ring are preferable, and a compound having a cyclopentene ring alone or a compound having a polycyclic structure of a cyclopentane ring and a benzene ring is particularly preferable. R ¹ and R ⁴ other than R ² and R ³ forming the ring structure may be the same or different, and are preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Also in this case, a compound represented by a general formula in which m is 0 is preferable.

As the compound in which R ² and R ³ are bonded to each other to form a ring, unsubstituted or hydrocarbon-substituted bicyclo [2.2.1] hept-2-enes are preferable, and among them, Dicyclopentadiene, methyldicyclopentadiene, dihydrodicyclopentadiene, 1,4-methano-1,4,4a, 9a-tetrahydro-9H-fluorene, 1,4-methano-1,4,4a, 9,9a, 10-hexahydroanthracene is preferred, and dicyclopentadiene, 1,4-methano-1,4,4a, 9a-tetrahydro-9H-fluorene is more preferred.

  The norbornene compounds in the present invention may be used alone or in combination of two or more.

  In the ring-opening copolymer contained in the composition for a bending fatigue-resistant material of the present invention, the content ratio of the structural unit derived from a monocyclic olefin to all the repeating structural units is preferably 10 to 75% by weight. Yes, more preferably 15 to 70% by weight, still more preferably 15 to 60% by weight, particularly preferably 15 to 55% by weight, and most preferably 15 to 39% by weight. When the content ratio of the structural unit derived from a monocyclic olefin is within the above range, a bending fatigue-resistant material exhibiting more excellent bending fatigue resistance and a lower friction coefficient can be provided.

  In the ring-opening copolymer contained in the composition for a bending fatigue resistant material of the present invention, the content ratio of the structural unit derived from the norbornene compound with respect to all the repeating structural units is preferably 25 to 90% by weight, It is preferably from 30 to 85% by weight, more preferably from 40 to 85% by weight, particularly preferably from 45 to 85% by weight, most preferably from 61 to 85% by weight. When the content ratio of the structural unit derived from the norbornene compound is within the above range, a bending fatigue-resistant material exhibiting more excellent bending fatigue resistance and a lower friction coefficient can be provided.

  In addition, the ring-opening copolymer in the present invention may be a copolymer obtained by copolymerizing a monocyclic cycloolefin and a norbornene compound and another monomer copolymerizable therewith. Examples of such other monomers include polycyclic cycloolefins having an aromatic ring. Examples of the polycyclic cycloolefin having an aromatic ring include phenylcyclooctene, 5-phenyl-1,5-cyclooctadiene, and phenylcyclopentene. In the ring-opening copolymer of the present invention, the content ratio of the structural unit derived from another monomer to all the repeating structural units is preferably 40% by weight or less, more preferably 30% by weight or less, It is particularly preferred that the ring-opening copolymer in the present invention is substantially free of structural units derived from other monomers.

  The weight average molecular weight (Mw) of the ring-opening copolymer in the present invention is preferably 50,000 to 1,000, as a value of the weight average molecular weight (Mw) in terms of polystyrene measured by gel permeation chromatography. 000, more preferably 50,000 to 800,000, still more preferably 100,000 to 700,000, and particularly preferably 150,000 to 600,000. When the weight average molecular weight (Mw) is in the above range, the obtained bending fatigue resistant material exhibits superior bending fatigue resistance and a lower coefficient of friction while maintaining good production and handling. be able to. Further, the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) in terms of polystyrene measured by gel permeation chromatography of the ring-opened copolymer in the present invention is preferably It is 1.0 to 5.0, more preferably 1.5 to 3.0.

  The cis / trans ratio of the ring-opening copolymer in the present invention is preferably 0/100 to 50/50, more preferably 5/95 to 45/55, and further preferably 10/90 to 40/60. And particularly preferably 15/85 to 39/61. The cis / trans ratio is the content ratio (cis / trans ratio) between the cis structure and the trans structure of the double bond present in the repeating unit constituting the ring-opening copolymer in the present invention. By setting the cis / trans ratio in the above range, the flex fatigue-resistant material of the present invention obtained by using the ring-opening copolymer exhibits superior flex fatigue resistance and a lower friction coefficient. Can be.

  The glass transition temperature (Tg) of the ring-opening copolymer in the present invention is preferably -80 to 10C, more preferably -70 to 0C, and still more preferably -65 to -2C. By setting the glass transition temperature (Tg) within the above range, the flex fatigue-resistant material of the present invention obtained by using the ring-opening copolymer can exhibit superior flex fatigue resistance and a lower friction coefficient. can do. The glass transition temperature of the ring-opening copolymer can be controlled, for example, by adjusting the type and amount of the norbornene compound used.

  Further, the ring-opening copolymer in the present invention may have a modifying group at a polymer chain terminal. By having such a terminal modifying group, there is a possibility that the affinity for the inorganic material can be further increased, and thus, when the inorganic material is blended, the dispersibility of the inorganic material in the bending fatigue resistant material Can be increased, and as a result, the bending fatigue resistance in the case of using the bending fatigue resistant material can be further increased, and the friction coefficient can be further reduced in some cases. The modifying group to be introduced into the polymer chain terminal is not particularly limited, but is a modifying group containing an atom selected from the group consisting of an atom of Group 15 of the periodic table, an atom of Group 16 of the periodic table, and a silicon atom. Is preferred.

  As a modifying group for forming a terminal modifying group, affinity for an inorganic material can be increased, and thereby, when a bending fatigue-resistant material is used, the bending fatigue resistance is further increased, and the friction coefficient is further reduced. From the viewpoint that it is possible, a nitrogen atom, an oxygen atom, a phosphorus atom, a sulfur atom, and a modified group containing an atom selected from the group consisting of a silicon atom is more preferable, among these, a nitrogen atom, an oxygen atom, and Modification groups containing atoms selected from the group consisting of silicon atoms are more preferred.

  Examples of the modifying group containing a nitrogen atom include an amino group, a pyridyl group, an imino group, an amide group, a nitro group, a urethane bonding group, and a hydrocarbon group containing any of these groups. Examples of the modifying group containing an oxygen atom include a hydroxyl group, a carboxylic acid group, an ether group, an ester group, a carbonyl group, an aldehyde group, an epoxy group, and a hydrocarbon group containing any of these groups. Examples of the modifying group containing a silicon atom include an alkylsilyl group, an oxysilyl group, and a hydrocarbon group containing any of these groups. Examples of the modifying group containing a phosphorus atom include a phosphate group, a phosphino group, and a hydrocarbon group containing any of these groups. Examples of the modifying group containing a sulfur atom include a sulfonyl group, a thiol group, a thioether group, and a hydrocarbon group containing any of these groups. The modifying group may be a modifying group containing a plurality of the above groups. Among these, in the case of a crosslinked product for a bending fatigue resistant material, a specific example of a particularly preferable modifying group from the viewpoint of further increasing the bending fatigue resistance and lowering the friction coefficient is an amino group. A pyridyl group, an imino group, an amide group, a hydroxyl group, a carboxylic acid group, an aldehyde group, an epoxy group, an oxysilyl group, or a hydrocarbon group containing any of these groups, and from the viewpoint of affinity for silica, oxysilyl. Groups are particularly preferred. Note that an oxysilyl group refers to a group having a silicon-oxygen bond.

  Specific examples of the oxysilyl group include an alkoxysilyl group, an aryloxysilyl group, an acyloxy group, an alkylsiloxysilyl group, and an arylsiloxysilyl group. Further, an alkoxysilyl group, an aryloxysilyl group, and a hydroxysilyl group obtained by hydrolyzing an acyloxy group can be exemplified. Among these, an alkoxysilyl group is preferable from the viewpoint of affinity for an inorganic material.

  The alkoxysilyl group is a group in which one or more alkoxy groups are bonded to a silicon atom, and specific examples thereof include a trimethoxysilyl group, a (dimethoxy) (methyl) silyl group, and a (methoxy) (dimethyl) silyl. Group, (methoxy) (dichloro) silyl group, triethoxysilyl group, (diethoxy) (methyl) silyl group, (ethoxy) (dimethyl) silyl group, (dimethoxy) (ethoxy) silyl group, (methoxy) (diethoxy) silyl And a tripropoxysilyl group.

The rate of introduction of the modifying group at the polymer chain end of the ring-opening copolymer is not particularly limited, and the percentage of the number of the ring-opening copolymer chain terminals into which the modifying group is introduced / the total number of the ring-opening copolymer chain terminals is referred to. The value is preferably at least 10%, more preferably at least 20%, further preferably at least 30%, particularly preferably at least 40%. The higher the introduction ratio of the terminal modifying group, the higher the affinity with the inorganic material, and the better the low heat buildup. The method of measuring the rate of introduction of the modifying group to the polymer chain end is not particularly limited. When the oxysilyl group is introduced as the terminal modifying group, for example, oxysilyl obtained by ¹ H-NMR spectrum measurement is used. It can be determined from the peak area ratio corresponding to the group and the number average molecular weight determined from gel permeation chromatography.

  The Mooney viscosity (ML1 + 4, 100 ° C.) of the ring-opening copolymer in the present invention is preferably 20 to 150, more preferably 22 to 120, and still more preferably 25 to 90. By setting the Mooney viscosity in the above range, kneading at ordinary temperature and high temperature can be easily performed, thereby improving processability.

  The method for producing the ring-opening copolymer in the present invention is not particularly limited, and includes, for example, a method in which a monocyclic olefin and a norbornene compound are copolymerized in the presence of a ring-opening polymerization catalyst.

  As the ring-opening polymerization catalyst, any catalyst capable of ring-opening copolymerization with a monocyclic olefin and a norbornene compound may be used, and among them, a ruthenium carbene complex is preferable.

  Specific examples of the ruthenium carbene complex include bis (tricyclohexylphosphine) benzylidene ruthenium dichloride, bis (triphenylphosphine) -3,3-diphenylpropenylidene ruthenium dichloride, bis (tricyclohexylphosphine) t-butylvinylidene ruthenium dichloride, Dichloro- (3-phenyl-1H-indene-1-ylidene) bis (tricyclohexylphosphine) ruthenium, bis (1,3-diisopropylimidazoline-2-ylidene) benzylidene ruthenium dichloride, bis (1,3-dicyclohexylimidazoline-2) -Ylidene) benzylidene ruthenium dichloride, (1,3-dimesitylimidazoline-2-ylidene) (tricyclohexylphosphine) benzylidene ruthenium dichloride Lido, (1,3-dimesitylimidazolidine-2-ylidene) (tricyclohexylphosphine) benzylidene ruthenium dichloride, bis (tricyclohexylphosphine) ethoxymethylidene ruthenium dichloride, (1,3-dimesitylimidazolidine-2) -Ylidene) (tricyclohexylphosphine) ethoxymethylidene ruthenium dichloride. As the ring-opening polymerization catalyst, one type may be used alone, or two or more types may be used in combination.

  The amount of the ring-opening polymerization catalyst used is usually from 1: 500 to 1: 2,000,000, preferably from 1: 700 to 1: 1 in a molar ratio of (ring-opening polymerization catalyst: monomer used for copolymerization). , 500,000, more preferably in the range of 1: 1,000 to 1: 1,000,000.

  The polymerization reaction may be performed without a solvent or in a solution. When copolymerizing in a solution, the solvent used is inert in the polymerization reaction, and is not particularly limited as long as it is a solvent capable of dissolving a monocyclic olefin, a norbornene compound, a polymerization catalyst, and the like used for the copolymerization. It is preferable to use a hydrogen solvent or a halogen solvent. Examples of the hydrocarbon solvent include aromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene; aliphatic hydrocarbons such as hexane, n-heptane and n-octane; alicyclic rings such as cyclohexane, cyclopentane and methylcyclohexane. Group hydrocarbons; and the like. Examples of the halogen-based solvent include haloalkanes such as dichloromethane and chloroform; and aromatic halogens such as chlorobenzene and dichlorobenzene. These solvents may be used alone or as a mixture of two or more.

  When performing ring-opening copolymerization of a monocyclic cyclic olefin and a norbornene compound, if necessary, an olefin compound or diolefin may be used as a molecular weight modifier to adjust the molecular weight of the obtained ring-opening copolymer. The compound may be added to the polymerization reaction system.

  The olefin compound is not particularly limited as long as it is an organic compound having an ethylenically unsaturated bond. For example, α-olefins such as 1-butene, 1-pentene, 1-hexene and 1-octene; styrene, vinyltoluene Styrenes; halogen-containing vinyl compounds such as allyl chloride; vinyl ethers such as ethyl vinyl ether and i-butyl vinyl ether; silicon-containing vinyl compounds such as allyltrimethoxysilane, allyltriethoxysilane, allyltrichlorosilane, and styryltrimethoxysilane. Disubstituted olefins such as 2-butene and 3-hexene;

  Examples of the diolefin compound include 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,6-heptadiene, 2-methyl-1,4-pentadiene, and 2,5-dimethyl-1,5-diene. Non-conjugated diolefins such as hexadiene are included.

  The amount of the olefin compound and the diolefin compound used as the molecular weight modifier may be appropriately selected according to the molecular weight of the ring-opening copolymer to be produced. It is usually in the range of 1/100 to 1 / 100,000, preferably 1/200 to 1 / 50,000, more preferably 1/500 to 1 / 10,000.

  When the ring-opening copolymer of the present invention has a modifying group at the polymer chain end, a modified group-containing olefin may be used as a molecular weight modifier instead of the above-mentioned olefin compound or diolefin compound. It is preferable to use a water-soluble unsaturated hydrocarbon compound. By using such a modified group-containing olefinically unsaturated hydrocarbon compound, a modified group can be suitably introduced into a polymer chain terminal of a ring-opened copolymer obtained by copolymerization.

  The modifying group-containing olefinically unsaturated hydrocarbon compound is not particularly limited as long as it is a compound having a modifying group and having one olefinic carbon-carbon double bond having metathesis reactivity. For example, when it is desired to introduce an oxysilyl group at the polymer chain end of the ring-opening copolymer, an oxysilyl group-containing olefinically unsaturated hydrocarbon may be present in the polymerization reaction system.

  Examples of such oxysilyl group-containing olefinically unsaturated hydrocarbons include vinyl (trimethoxy) silane and vinyl (trimethoxy) silane, which introduce a modifying group into only one terminal (one terminal) of the polymer chain of the ring-opening copolymer. Vinyl (triethoxy) silane, allyl (trimethoxy) silane, allyl (methoxy) (dimethyl) silane, allyl (triethoxy) silane, allyl (ethoxy) (dimethyl) silane, styryl (trimethoxy) silane, styryl (triethoxy) silane, styrylethyl Alkoxysilane compounds such as (triethoxy) silane, allyl (triethoxysilylmethyl) ether, allyl (triethoxysilylmethyl) (ethyl) amine; vinyl (triphenoxy) silane, allyl (triphenoxy) silane, allyl (phenoxy) ( Dimethyl) Aryloxysilane compounds such as vinylene; allyloxysilane compounds such as vinyl (triacetoxy) silane, allyl (triacetoxy) silane, allyl (diacetoxy) methylsilane, allyl (acetoxy) (dimethyl) silane; allyltris (trimethylsiloxy) silane Alkylsiloxysilane compounds; arylsiloxysilane compounds such as allyltris (triphenylsiloxy) silane; 1-allylheptamethyltrisiloxane, 1-allylnonamethyltetrasiloxane, 1-allylnonamethylcyclopentasiloxane, 1-allylundeca Polysiloxane compounds such as methylcyclohexasiloxane; and the like.

  Bis (trimethoxysilyl) ethylene, bis (triethoxysilyl) ethylene, 2-butene-1, 2-butene-1, etc. may be used to introduce a modifying group at both ends (both ends) of the polymer chain of the ring-opening copolymer. Alkoxysilane compounds such as 4-di (trimethoxysilane), 2-butene-1,4-di (triethoxysilane) and 1,4-di (trimethoxysilylmethoxy) -2-butene; 2-butene-1 Aryloxysilane compounds such as 2,4-di (triphenoxysilane); acyloxysilane compounds such as 2-butene-1,4-di (triacetoxysilane); 2-butene-1,4-di [tris (trimethyl Alkylsiloxysilane compounds such as [siloxy) silane]; arylsiloxysilanes such as 2-butene-1,4-di [tris (triphenylsiloxy) silane] Compounds; 2-butene-1,4-di (heptamethyltrisiloxane), polysiloxane compounds such as 2-butene-1,4-di (undecapeptide methyl cyclohexasiloxane); and the like.

  Modified group-containing olefinically unsaturated hydrocarbon compounds such as oxysilyl group-containing olefinically unsaturated hydrocarbon compounds, in addition to the action of introducing a modifying group into the polymer chain end of the ring-opening copolymer, also serve as a molecular weight regulator. The amount of the modified group-containing olefinically unsaturated hydrocarbon compound to be used may be appropriately selected according to the molecular weight of the ring-opening copolymer to be produced. The ratio is usually in the range of 1/100 to 1 / 100,000, preferably 1/200 to 1 / 50,000, more preferably 1/500 to 1 / 10,000.

  The polymerization reaction temperature is not particularly limited, but is preferably -100 ° C or higher, more preferably -50 ° C or higher, further preferably 0 ° C or higher, and particularly preferably 20 ° C or higher. The upper limit of the polymerization reaction temperature is not particularly limited, but is preferably lower than 120 ° C, more preferably lower than 100 ° C, further preferably lower than 90 ° C, and particularly preferably lower than 80 ° C. The polymerization reaction time is also not particularly limited, but is preferably 1 minute to 72 hours, more preferably 10 minutes to 20 hours.

  If necessary, an antioxidant such as a phenol-based stabilizer, a phosphorus-based stabilizer, or a sulfur-based stabilizer may be added to the ring-opening copolymer obtained by the polymerization reaction. The amount of the antioxidant to be added may be appropriately determined depending on the type and the like. Further, if desired, an extender oil may be blended. When a ring-opening copolymer is obtained as a polymerization solution, in order to recover the ring-opening copolymer from the polymerization solution, a known recovery method may be adopted, for example, the solvent is separated by steam stripping or the like. Thereafter, a method of filtering the solid and drying the solid to obtain a solid ring-opened copolymer can be employed.

  Further, the composition for a bending fatigue resistant material of the present invention may contain a rubber other than the above-mentioned ring-opening copolymer as a rubber component. In the present invention, the rubber component refers to the above-mentioned ring-opening copolymer and a rubber other than the above-mentioned ring-opening copolymer. Examples of the rubber other than the above-mentioned ring-opening copolymer include natural rubber (NR), polyisoprene rubber (IR), emulsion-polymerized SBR (styrene-butadiene copolymer rubber), and solution-polymerized random SBR (bonded styrene 5 to 50). Wt%, 1,2-bond content of butadiene portion 10-80%), high trans SBR (trans bond content of butadiene portion 70-95%), low cis BR (polybutadiene rubber), high cis BR, high trans BR (trans bond content of butadiene part 70-95%), ethylene-propylene-diene rubber (EPDM), styrene-isoprene copolymer rubber, butadiene-isoprene copolymer rubber, emulsion-polymerized styrene-acrylonitrile-butadiene copolymer rubber, acrylonitrile -Butadiene copolymer rubber, high vinyl SBR-low vinyl SBR Rubber, polyisoprene-SBR block copolymer rubber, polystyrene-polybutadiene-polystyrene block copolymer, acrylic rubber, epichlorohydrin rubber, fluorine rubber, silicone rubber, ethylene-propylene rubber, urethane rubber, etc. . Among them, NR, BR, IR, EPDM, and SBR are preferable, and solution-polymerized random SBR is particularly preferably used. These rubbers can be used alone or in combination of two or more.

  In the present invention, the rubber other than the above-mentioned ring-opening copolymer may have a modifying group at the polymer terminal. In addition, as the modifying group which may be present at the polymer terminal of the rubber other than the above-described ring-opening copolymer, the same modifying group as the modifying group which may be present at the polymer terminal of the above-described ring-opening copolymer may be mentioned. And the same modifying group as the suitable modifying group which may be present at the polymer terminal of the above-mentioned ring-opening copolymer.

  For example, as an example of the rubber other than the above-described ring-opening copolymer, SBR having a modifying group at the polymer terminal (hereinafter, referred to as “terminal-modified SBR”) may be mentioned.

  The terminal-modified SBR is obtained by subjecting a monomer mixture containing 1,3-butadiene and styrene to living anion polymerization using an organic alkali metal compound such as n-butyllithium as a polymerization initiator. Those obtained by reacting an SBR having an active terminal with a denaturing agent are preferred.

  The modifier is not particularly limited, but is preferably a silicon atom-containing modifier, and more preferably a siloxane compound, from the viewpoint that the flex fatigue resistance can be further increased and the friction coefficient can be further reduced.

The siloxane compound is not particularly limited as long as it has a siloxane structure (—Si—O—) as a main chain structure, but is preferably an organosiloxane having an organic group in a side chain, and represented by the following general formula (2). The polyorganosiloxanes represented are more preferred.

In the general formula (2), R ^{5 to} R ¹² are an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, which may be the same or different from each other. . X ¹ and X ⁴ are an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, and a group having 4 to 12 carbon atoms containing an epoxy group. Any group selected from the group, which may be the same or different from each other. X ² is an alkoxy group having 1 to 5 carbon atoms or a group having 4 to 12 carbon atoms containing an epoxy group, and when there are a plurality of X ² , they may be the same or different. Good. X ³ is a group containing 2 to 20 alkylene glycol repeating units, and when there are a plurality of X ³ , they may be the same or different. h is an integer of 0 to 200, n is an integer of 0 to 200, k is an integer of 0 to 200, and h + n + k is 1 or more.

In the polyorganosiloxane represented by the general formula (2), examples of the alkyl group having 1 to 6 carbon atoms that can constitute R ^{5 to} R ¹² , X ¹ and X ⁴ in the general formula (2) include: , A methyl group, an ethyl group, an n-propyl group, an isopropyl group, a butyl group, a pentyl group, a hexyl group and a cyclohexyl group. Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group and a methylphenyl group. Among these, a methyl group and an ethyl group are preferable from the viewpoint of easiness of production of the polyorganosiloxane itself.

In the polyorganosiloxane represented by the general formula (2), examples of the alkoxy group having 1 to 5 carbon atoms that can constitute X ¹ , X ² and X ⁴ include a methoxy group, an ethoxy group, and a propoxy group. , An isopropoxy group and a butoxy group. Among these, a methoxy group and an ethoxy group are preferred from the viewpoint of easy production of the polyorganosiloxane itself.

Further, in the polyorganosiloxane represented by the general formula (2), the group having 4 to 12 carbon atoms containing an epoxy group capable of constituting X ¹ , X ² and X ⁴ is, for example, the following general formula ( And groups represented by 3).
-Z ¹ -Z ² -E (3)
In the above general formula (3), Z ¹ is an alkylene group having 1 to 10 carbon atoms or an alkylarylene group, Z ² is a methylene group, a sulfur atom, or an oxygen atom, and E is a carbon atom having an epoxy group. It is a hydrocarbon group of several 2 to 10.

The group represented by the general formula (3) is preferably a Z ² is an oxygen atom, Z ² is an oxygen atom, and is more preferable E is a glycidyl group, Z ¹ is carbon Particularly preferred are alkylene groups of the formulas 1 to 3, wherein Z ² is an oxygen atom and E is a glycidyl group.

In the polyorganosiloxane represented by the general formula (2), X ¹ and X ⁴ are, among the above, an epoxy group-containing group having 4 to 12 carbon atoms or a group having 1 to 6 carbon atoms. Alkyl groups are preferred. X ² is preferably an epoxy group-containing group having 4 to 12 carbon atoms. Further, X ¹ and X ⁴ are more preferably an alkyl group having 1 to 6 carbon atoms, and X ² is more preferably a group having 4 to 12 carbon atoms containing an epoxy group.

上記一般式（４）中、ａは２〜２０の整数であり、Ｘ^５は炭素数２〜１０のアルキレン基またはアルキルアリーレン基であり、Ｒ^１３は水素原子またはメチル基であり、Ｘ^６は炭素数１〜１０のアルコキシ基またはアリールオキシ基である。これらの中でも、ａが２〜８の整数であり、Ｘ^５が炭素数３のアルキレン基であり、Ｒ^１３が水素原子であり、かつ、Ｘ^６がメトキシ基であるものが好ましい。 In the polyorganosiloxane represented by the general formula (2), X ³ , that is, the group containing 2 to 20 alkylene glycol repeating units is preferably a group represented by the following general formula (4). .

In the above general formula (4), a is an integer of 2 to 20, X ⁵ is an alkylene group or an alkyl arylene group having 2 to 10 carbon atoms, R ¹³ is a hydrogen atom or a methyl group, and X ⁶ is It is an alkoxy group or an aryloxy group having 1 to 10 carbon atoms. Among these, those in which a is an integer of 2 to 8, X ⁵ is an alkylene group having 3 carbon atoms, R ¹³ is a hydrogen atom, and X ⁶ is a methoxy group are preferred.

  In the polyorganosiloxane represented by the general formula (2), h is an integer of 0 to 200, preferably an integer of 20 to 150, and more preferably an integer of 30 to 120. When h is 200 or less, the production of the polyorganosiloxane itself represented by the general formula (2) becomes easier, the viscosity does not become too high, and the handling becomes easier.

  In the polyorganosiloxane represented by the general formula (2), n is an integer of 0 to 200, preferably an integer of 0 to 150, and more preferably an integer of 0 to 120. k is an integer of 0 to 200, preferably an integer of 0 to 150, and more preferably an integer of 0 to 130. The total number of h, n and k is 1 or more, preferably 2 to 400, more preferably 20 to 300, and particularly preferably 30 to 250. When the total number of h, n, and k is 1 or more, the reaction between the polyorganosiloxane represented by the general formula (2) and the active terminal of the conjugated diene rubber easily proceeds, and further, h, n When the total number of k and k is 400 or less, the production of the polyorganosiloxane represented by the general formula (2) itself becomes easy, the viscosity does not become too high, and the handling becomes easy.

  The content of the ring-opening copolymer in the composition for bending fatigue resistance material of the present invention is preferably at least 10% by weight, more preferably at least 20% by weight, based on the total amount of the rubber component. Preferably, it is particularly preferably at least 30% by weight, usually at most 100% by weight, or at most 90% by weight. If this ratio is too low, the effect of improving the bending fatigue resistance and the effect of reducing the friction coefficient may not be obtained.

  The composition for a bending fatigue resistant material of the present invention contains an inorganic material that functions as a filler. As the inorganic material contained in the composition for a bending fatigue resistant material of the present invention, a carbon material or silica is preferable, and among them, a carbon material is more preferable. As the carbon material, carbon black is preferable.

  Examples of the carbon black used as the inorganic material included in the composition for a bending fatigue resistant material of the present invention include furnace black, acetylene black, thermal black, channel black, graphite, and the like. Among these, furnace black is preferable, and specific examples thereof include SAF, ISAF, ISAF-HS, ISAF-LS, IISAF-HS, HAF, HAF-HS, HAF-LS, and FEF. These carbon blacks can be used alone or in combination of two or more.

The nitrogen adsorption specific surface area (N ₂ SA) of carbon black is preferably 5 to 200 m ² / g, more preferably 70 to 120 m ² / g, and the dibutyl phthalate (DBP) adsorption amount is preferably 5 to 200 m ² / g. It is 300 ml / 100 g, more preferably 80 to 160 ml / 100 g.

  Examples of the silica used as the inorganic material contained in the composition for a bending fatigue resistant material of the present invention include, for example, dry white carbon, wet white carbon, and colloidal silica, which are disclosed in JP-A-62-62838. Precipitated silica. Among these, wet-process white carbon containing hydrated silicic acid as a main component is preferable. Further, a carbon-silica dual phase filler having silica supported on the surface of carbon black may be used. These silicas can be used alone or in combination of two or more.

The nitrogen adsorption specific surface area of the silica (measured by the BET method according to ASTM D3037-81) is preferably from 50 to 400 m ² / g, more preferably from 100 to 220 m ² / g. Further, the pH of the silica is preferably lower than pH 7, more preferably pH 5 to 6.9. Within these ranges, the affinity between the ring-opening copolymer and silica becomes particularly good.

  When using silica as the inorganic material, for the purpose of further improving the affinity between the ring-opening copolymer and silica, the composition for a bending fatigue-resistant material of the present invention may further include a silane coupling agent. preferable. Examples of the silane coupling agent include vinyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, bis (3- (Triethoxysilyl) propyl) tetrasulfide, bis (3- (triethoxysilyl) propyl) disulfide, and the like, and γ-trimethoxysilylpropyldimethylthiocarbamyl tetrasulfide described in JP-A-6-248116. Examples thereof include tetrasulfides such as γ-trimethoxysilylpropylbenzothiazyltetrasulfide. Among them, tetrasulfides are preferred. These silane coupling agents can be used alone or in combination of two or more. The compounding amount of the silane coupling agent is preferably 0.1 to 30 parts by weight, more preferably 1 to 15 parts by weight, based on 100 parts by weight of the inorganic material.

  The content of the inorganic material in the present invention is preferably 10 to 150 parts by weight, more preferably 20 to 120 parts by weight, and still more preferably 40 to 100 parts by weight, based on 100 parts by weight of the rubber component.

  In the composition for flex fatigue resistance material of the present invention, in addition to the above components, according to a conventional method, a crosslinking agent, a crosslinking accelerator, a crosslinking activator, a filler other than inorganic materials, an antioxidant, an activator, Compounding agents such as process oils, plasticizers, lubricants and the like can be compounded in required amounts.

  Examples of the crosslinking agent include sulfur such as powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, and highly dispersible sulfur; sulfur halides such as sulfur monochloride and sulfur dichloride; dicumyl peroxide, ditertiary butyl peroxide and the like. Organic peroxides; quinone dioximes such as p-quinone dioxime and p, p'-dibenzoylquinone dioxime; and organics such as triethylenetetramine, hexamethylenediaminecarbamate and 4,4'-methylenebis-o-chloroaniline. Polyhydric amine compounds; alkylphenol resins having a methylol group; and the like. Among these, sulfur is preferred, and powdered sulfur is more preferred. These crosslinking agents are used alone or in combination of two or more. The amount of the crosslinking agent to be added is preferably 0.1 to 15 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the rubber component in the composition for bending fatigue resistance material.

  Examples of the crosslinking accelerator include N-cyclohexyl-2-benzothiazolylsulfenamide, N- (tert-butyl) -2-benzothiazolylsulfenamide, N-oxyethylene-2-benzothiazolylsulfen Sulfenamide-based crosslinking accelerators such as amide, N-oxyethylene-2-benzothiazolylsulfenamide, N, N′-diisopropyl-2-benzothiazolylsulfenamide; 1,3-diphenylguanidine; Guanidine-based cross-linking accelerators such as 3-dioltotolylguanidine and 1-ortho-tolylbiguanidine; thiourea-based cross-linking accelerators such as diethylthiourea; 2-mercaptobenzothiazole, dibenzothiazyl disulfide, and 2-mercaptobenzothiazole zinc salt Thiazole crosslinking accelerators; Thiuram-based crosslinking promoters such as lamethylthiuram monosulfide and tetramethylthiuram disulfide; dithiocarbamic acid-based crosslinking promoters such as sodium dimethyldithiocarbamate and zinc diethyldithiocarbamate; sodium isopropylxanthate, zinc isopropylxanthogenate, and zinc butylxanthate And xanthic acid-based crosslinking accelerators. Among them, those containing a sulfenamide-based crosslinking accelerator are preferred, and those containing N- (tert-butyl) -2-benzothiazolylsulfenamide are particularly preferred. These crosslinking accelerators are used alone or in combination of two or more. The compounding amount of the crosslinking accelerator is preferably 0.1 to 15 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the rubber component in the composition for a bending fatigue resistant material.

  As the crosslinking activator, for example, higher fatty acids such as stearic acid, zinc oxide, and the like can be used. The amount of the crosslinking activator is appropriately selected, but the amount of the higher fatty acid is preferably 0.05 to 15 parts by weight, more preferably 0.1 to 15 parts by weight, based on 100 parts by weight of the rubber component in the rubber composition. 5 to 5 parts by weight, and the compounding amount of zinc oxide is preferably 0.05 to 10 parts by weight, more preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the rubber component in the composition for a bending fatigue resistant material. ３3 parts by weight.

  Mineral oil or synthetic oil may be used as the process oil. As the mineral oil, aroma oil, naphthenic oil, paraffin oil and the like are usually used. Other compounding agents include activators such as diethylene glycol, polyethylene glycol and silicone oil; fillers other than inorganic materials such as calcium carbonate, talc and clay; tackifiers such as petroleum resins and cumarone resins; waxes and the like. .

As the composition for a flex fatigue-resistant material of the present invention, a structural unit derived from a monocyclic cycloolefin and R ^{1 to} R ⁴ in the general formula (1) are a hydrogen atom, a chain carbonized carbon atom having 1 to 20 carbon atoms. A composition for a bending fatigue resistant material containing a carbon black and a ring-opening copolymer containing a structural unit derived from a norbornene compound which is a substituent containing a hydrogen group or a halogen atom, a silicon atom, an oxygen atom or a nitrogen atom is preferable. . With such a composition for a bending fatigue resistant material, a bending fatigue resistant material exhibiting more excellent bending fatigue resistance and a lower coefficient of friction can be provided.

  The composition for a bending fatigue-resistant material of the present invention can be obtained by kneading the components according to a conventional method. For example, after kneading a compounding agent excluding a crosslinking agent and a crosslinking accelerator and a rubber component such as a ring-opening copolymer, the kneaded product is mixed with a crosslinking agent and a crosslinking accelerator to form a composition for a bending fatigue resistant material. Can be obtained. The kneading temperature of the compounding agent excluding the crosslinking agent and the crosslinking accelerator and the rubber component such as the ring-opening copolymer is preferably 20 to 200 ° C., more preferably 30 to 180 ° C., and the kneading time is preferably 30 seconds to 30 minutes. Mixing of the crosslinking agent and the crosslinking accelerator is usually performed at 100 ° C. or lower, preferably at 80 ° C. or lower.

<Crosslinked product for bending fatigue resistant material>
The crosslinked product for a bending fatigue resistant material of the present invention is obtained by crosslinking the composition for a bending fatigue resistant material of the present invention described above.
The crosslinked product for bending fatigue-resistant material of the present invention uses the composition for bending fatigue-resistant material of the present invention, for example, a molding machine corresponding to a desired shape, for example, an extruder, an injection molding machine, a compressor, It can be manufactured by molding by a roll or the like, performing a crosslinking reaction by heating, and fixing the shape as a crosslinked product. In this case, crosslinking may be performed after molding in advance, or crosslinking may be performed simultaneously with molding. The molding temperature is usually from 10 to 200C, preferably from 25 to 120C. The crosslinking temperature is usually 100 to 200 ° C, preferably 130 to 190 ° C, and the crosslinking time is usually 1 minute to 24 hours, preferably 2 minutes to 12 hours, particularly preferably 3 minutes to 6 hours. .

  In addition, depending on the shape, size, etc. of the crosslinked product for a bending fatigue resistant material, the surface may be crosslinked and the interior may not be sufficiently crosslinked. Good.

  As a heating method, a general method used for rubber crosslinking, such as press heating, steam heating, oven heating, and hot air heating, may be appropriately selected.

  The thus obtained crosslinked product for a bending fatigue resistant material of the present invention has a high number of times of bending at break and a low coefficient of friction. Specifically, the crosslinked product for a bending fatigue-resistant material of the present invention has a number of bending times at break of 40,000 times or more measured in a bending crack initiation test according to JIS K6260: 2010. Is preferably 60,000 times or more, more preferably 80,000 times or more, and particularly preferably 100,000 times or more. Further, the crosslinked product for a bending fatigue resistant material of the present invention preferably has a static friction coefficient of 1.0 or less, and preferably 0.8 or less, measured in a friction coefficient test based on JIS K7125: 1999. More preferably, it is still more preferably 0.7 or less, and particularly preferably 0.5 or less. Further, the crosslinked product for a bending fatigue-resistant material of the present invention preferably has a dynamic friction coefficient measured in a friction coefficient test of 1.0 or less, and preferably 0.7 or less, in accordance with JIS K7125: 1999. Is more preferably 0.6 or less, still more preferably 0.5 or less.

<Bending fatigue resistant material>
The present invention uses the composition for a flex fatigue-resistant material or the crosslinked product for a flex fatigue-resistant material described above as a flex fatigue-resistant material. Since it is composed of a composition for a flex fatigue-resistant material or a crosslinked product for a flex fatigue-resistant material, it has excellent flex fatigue resistance and a low coefficient of friction. The flex fatigue-resistant material of the present invention makes use of such properties, for example, excellent flex resistance such as rubber for car wiper blades, covering materials for hoses, electric wires and cables, conveyor belts and rubber screens. It can be suitably used for various applications that require fatigue and a low coefficient of friction.

Hereinafter, the present invention will be described based on more detailed examples, but the present invention is not limited to these examples. In the following, “parts” are based on weight unless otherwise specified.
Various tests and evaluations were performed according to the following methods.

[Molecular weight of ring-opening copolymer and modified styrene-butadiene copolymer]
A gel permeation chromatography (GPC) system “HLC-8220” (manufactured by Tosoh Corporation) is used by connecting two H-type columns “HZ-M” (manufactured by Tosoh Corporation) in series and using tetrahydrofuran as a solvent. At a column temperature of 40 ° C. As a detector, a differential refractometer “RI-8320” (manufactured by Tosoh Corporation) was used. The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the ring-opened copolymer and the modified styrene-butadiene copolymer were measured in terms of polystyrene.

[Ratio of structural unit derived from norbornene compound and structural unit derived from monocyclic olefin]
The monomer composition ratio in the ring-opening copolymer was determined from ¹ H-NMR spectrum measurement.

[Glass transition temperature (Tg) of ring-opening copolymer and modified styrene-butadiene copolymer]
The glass transition temperature (Tg) of the ring-opened copolymer and the modified styrene-butadiene copolymer was determined using a differential scanning calorimeter (DSC "X-DSC7000" (manufactured by Hitachi High-Tech Science Corporation)) at -150 to 40. The temperature was measured up to 10 ° C. at a rate of 10 ° C./min.

[Cis / trans ratio of main chain double bond]
The cis / trans ratio of the main chain double bond of the ring-opening copolymer was determined from ¹³ C-NMR spectrum measurement.

[Bending crack initiation test]
A sample for a composition for bending fatigue-resistant material, which is a sample, is press-formed using a mold while applying pressure to obtain a crosslinked product for a bending fatigue-resistant material having a width of 25 mm, a length of 150 mm, and a thickness of 6.5 mm. Was. Then, the obtained crosslinked product for bending fatigue resistance material was tested using a Demacha bending tester (manufactured by Ueshima Seisakusho) as a tester in accordance with JIS K6260: 2010, with three test pieces and a reciprocating motion of 300. A bending crack initiation test was performed under the conditions of ± 10 times / minute, reciprocating distance of 57 mm, and 23 ° C., and the number of times of bending at break was measured. The greater the number of bends at break, the better the flex fatigue resistance.

[Friction coefficient test]
A sheet for the composition for bending fatigue resistant material to be a sample was prepared by press molding, and then punched to obtain a crosslinked product for bending fatigue resistant material of 63 mm × 63 mm. Then, the obtained sheet-like crosslinked product for bending fatigue-resistant material was subjected to JIS K7125: 1999 using a precision universal testing machine (product name “Autograph AG-X 10 kN”, manufactured by Shimadzu Corporation) as a testing machine. According to, the number of test pieces is 2, the test speed is 100 mm / min, the total mass of the test piece and the sliding piece is 210 g, the mating agent: water is applied to the surface of SUS304, and the coefficient of dynamic friction is calculated: the load of displacement between 20 to 80 mm A friction coefficient test was performed under the conditions of calculation from the average value, and a static friction coefficient and a dynamic friction coefficient were calculated.

[Synthesis Example 1]
Under a nitrogen atmosphere, 599 parts of 2-norbornene (NB) as a norbornene compound, 703 parts of cyclopentene (CPE) as a monocyclic olefin, 2411 parts of toluene, and 1.05 part of 1-hexene were placed in a glass reaction vessel equipped with a stirrer. added. Next, 0.154 parts of dichloro- (3-phenyl-1H-indene-1-ylidene) bis (tricyclohexylphosphine) ruthenium (II) dissolved in 35 parts of toluene was added, and a polymerization reaction was performed at room temperature for 3 hours. . After the polymerization reaction, the polymerization was terminated by adding excess vinyl ethyl ether.

  The polymerization solution was poured into a large excess of methanol containing 2,6-di-t-butyl-p-cresol (BHT), and the precipitated polymer was collected, washed with methanol, and then dried in vacuo at 50 ° C. for 3 days. As a result, 833 parts of a ring-opening copolymer (A) was obtained. The number average molecular weight (Mn) of the obtained ring-opened copolymer (A) is 127,000, the weight average molecular weight (Mw) is 234,000, and the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn). (Mw / Mn) is 1.84, 2-norbornene structural unit / cyclopentene structural unit ratio is 62/38 (weight ratio), cis / trans ratio is 17/83, and glass transition temperature (Tg) is -23 ° C. there were.

[Synthesis Example 2]
Under a nitrogen atmosphere, 65 parts of 1,4-methano-1,4,4a, 9a-tetrahydro-9H-fluorene (MTHF) as a norbornene compound and cyclopentene (CPE) as a monocyclic olefin were placed in a glass reaction vessel equipped with a stirrer. ) 84 parts, toluene 350 parts and 1-hexene 0.15 parts. Next, 0.015 part of dichloro- (3-phenyl-1H-indene-1-ylidene) bis (tricyclohexylphosphine) ruthenium (II) dissolved in 6 parts of toluene was added, and a polymerization reaction was performed at room temperature for 3 hours. . After the polymerization reaction, the polymerization was terminated by adding excess vinyl ethyl ether.

  The polymerization solution was poured into a large excess of methanol containing 2,6-di-t-butyl-p-cresol (BHT), and the precipitated polymer was collected, washed with methanol, and then dried in vacuo at 50 ° C. for 3 days. Thus, 135 parts of a ring-opening copolymer (B) were obtained. The obtained ring-opened copolymer (B) has a number average molecular weight (Mn) of 121,000, a weight average molecular weight (Mw) of 244,000, and a ratio between the weight average molecular weight (Mw) and the number average molecular weight (Mn). (Mw / Mn) is 2.02, 1,4-methano-1,4,4a, 9a-tetrahydro-9H-fluorene structural unit / cyclopentene structural unit ratio is 51/49 (weight ratio), cis / trans ratio Was 17/83, and the glass transition temperature (Tg) was -23 ° C.

[Synthesis Example 3]
Under a nitrogen atmosphere, in a glass reaction vessel equipped with a stirrer, 45 parts of dicyclopentadiene (DCPD) as a norbornene compound, 55 parts of cyclopentene (CPE) as a monocyclic olefin, 233 parts of toluene, and 0.08 part of 1-hexene are placed. added. Next, 0.011 part of dichloro- (3-phenyl-1H-indene-1-ylidene) bis (tricyclohexylphosphine) ruthenium (II) dissolved in 6 parts of toluene was added, and a polymerization reaction was performed at room temperature for 3 hours. . After the polymerization reaction, the polymerization was terminated by adding excess vinyl ethyl ether.

  The polymerization solution was poured into a large excess of methanol containing 2,6-di-t-butyl-p-cresol (BHT), and the precipitated polymer was collected, washed with methanol, and then dried in vacuo at 50 ° C. for 3 days. Thus, 62 parts of a ring-opened copolymer (C) was obtained. The obtained ring-opened copolymer (C) had a number average molecular weight (Mn) of 119,000, a weight average molecular weight (Mw) of 238,000, and a ratio between the weight average molecular weight (Mw) and the number average molecular weight (Mn). (Mw / Mn) is 2.00, dicyclopentadiene (DCPD) structural unit / cyclopentene structural unit ratio is 55/45 (weight ratio), cis / trans ratio is 17/83, and glass transition temperature (Tg) is − 25 ° C.

[Synthesis Example 4: Modified styrene-butadiene copolymer]
After charging 800 g of cyclohexane, 0.85 mmol of tetramethylethylenediamine, 94.8 g of 1,3-butadiene, and 25.2 g of styrene in a nitrogen atmosphere in an autoclave with a stirrer, 0.71 mmol of n-butyllithium was added, and 60 ° C. To initiate polymerization. Subsequently, after confirming that the polymerization conversion ratio was in the range of 95% to 100%, 0.08 mmol of tin tetrachloride was added and reacted for 30 minutes. Next, the polyorganosiloxane represented by the following formula (5) was converted into a 20% by weight xylene solution so as to have an epoxy group content equivalent to 0.33 times the mol of n-butyllithium used. And reacted for 30 minutes. Thereafter, as a polymerization terminator, an amount of methanol corresponding to twice the mole of n-butyllithium used was added to obtain a solution containing the modified styrene-butadiene copolymer. 0.15 parts of Irganox 1520L (manufactured by Ciba Specialty Chemicals) as an anti-aging agent was added to 100 parts of the modified styrene-butadiene copolymer, and the solvent was removed by steam stripping. And dried under vacuum at 60 ° C. for 24 hours to obtain a solid modified styrene-butadiene copolymer.

The resulting modified styrene-butadiene copolymer was found by GPC measurement to have an overall Mn of 336,000, an Mw of 481,000, and a ratio (Mw / Mn) between the weight average molecular weight (Mw) and the number average molecular weight (Mn). ) Was 1.43. The content of structural units derived from styrene of this modified styrene-butadiene copolymer was 21.2% by weight, and the vinyl bond content in the structural units derived from butadiene was 62.6, as determined by ¹ H-NMR measurement. % By weight, and the glass transition temperature (Tg) was -23 ° C.

[Example 1]
In a Banbury mixer, 100 parts of the ring-opening copolymer (A) obtained in Synthesis Example 1 is masticated for 60 seconds, and then 1 part of stearic acid and 3 parts of zinc oxide are added thereto. After kneading for 60 seconds, 50 parts of carbon black (trade name “IRB # 8”, manufactured by CONTINENTAL CARBON, nitrogen adsorption specific surface area (BET method): 76.3 m ² / g) were added and kneaded for 60 seconds. Thereafter, the compounding agent remaining on the upper part of the ram was cleaned, and then kneaded for another 120 seconds, and the kneaded material was discharged from the mixer. Next, after cooling the kneaded material to room temperature, the obtained kneaded material, 1.75 parts of sulfur, and N- (tert-butyl) -2-benzo as a cross-linking accelerator were used with an open roll at 50 ° C. After kneading with 1.0 part of thiazolyl sulfenamide (trade name “NOCSELER NS-P” manufactured by Ouchi Shinko Chemical Co., Ltd.), a sheet-shaped composition for a bending fatigue-resistant material was obtained.

Then, the obtained composition for bending fatigue-resistant material is press-crosslinked at 160 ° C. for 18 minutes while applying pressure using a mold to prepare a crosslinked product for bending fatigue-resistant material, and according to the above method, A bending crack initiation test was performed. Table 1 shows the results.
Further, using the obtained composition for bending fatigue resistant material, press-crosslinking was performed at 160 ° C. for 13 minutes to prepare a sheet-like crosslinked product for bending fatigue resistant material, and the static friction coefficient and the dynamic friction were determined according to the above method. The coefficient was measured. Table 1 shows the results.

[Example 2]
In the same manner as in Example 1 except that 100 parts of the ring-opening copolymer (B) obtained in Synthesis Example 2 was used instead of 100 parts of the ring-opening copolymer (A) obtained in Synthesis Example 1. Thus, a composition for a flex fatigue-resistant material and a crosslinked product for a flex fatigue-resistant material were obtained and similarly evaluated. Table 1 shows the results.

[Example 3]
In the same manner as in Example 1 except that 100 parts of the ring-opening copolymer (C) obtained in Synthesis Example 3 was used instead of 100 parts of the ring-opening copolymer (A) obtained in Synthesis Example 1. Thus, a composition for a bending fatigue resistant material was obtained.

Then, the obtained composition for bending fatigue-resistant material is press-crosslinked at 160 ° C. for 15 minutes while applying pressure using a mold to produce a crosslinked product for bending fatigue-resistant material, and according to the above method, A bending crack initiation test was performed. Table 1 shows the results.
Further, using the obtained composition for bending fatigue resistant material, press-crosslinking was performed at 160 ° C. for 10 minutes to prepare a sheet-like crosslinked product for bending fatigue resistant material. The coefficient was measured. Table 1 shows the results.

[Example 4]
Instead of 100 parts of the ring-opening copolymer (A) obtained in Synthesis Example 1, 50 parts of the ring-opening copolymer (A) obtained in Synthesis Example 1 and the modified styrene-butadiene obtained in Synthesis Example 4 A composition for a bending fatigue resistant material was obtained in the same manner as in Example 1 except that 50 parts of the copolymer was used.

Then, the obtained composition for bending fatigue-resistant material is press-crosslinked at 160 ° C. for 24 minutes while applying pressure using a mold to prepare a crosslinked product for bending fatigue-resistant material, and according to the above method, A bending crack initiation test was performed. Table 1 shows the results.
Further, using the obtained composition for bending fatigue-resistant material, press-crosslinking was performed at 160 ° C. for 19 minutes to prepare a sheet-like crosslinked product for bending fatigue-resistant material. The dynamic friction coefficient was measured. Table 1 shows the results.

[Comparative Example 1]
In the same manner as in Example 1 except that 100 parts of the modified styrene-butadiene copolymer obtained in Synthesis Example 4 was used instead of 100 parts of the ring-opening copolymer (A) obtained in Synthesis Example 1. Thus, a composition for a bending fatigue resistant material was obtained.

Then, the obtained composition for bending fatigue-resistant material, using a mold, press-crosslinking at 160 ° C. for 36 minutes while applying pressure to prepare a crosslinked product for bending fatigue-resistant material, according to the above method, A bending crack initiation test was performed. Table 1 shows the results.
Further, using the obtained composition for bending fatigue resistant material, press-crosslinking was performed at 160 ° C. for 31 minutes to prepare a sheet-like crosslinked product for bending fatigue resistant material. The rate was measured. Table 1 shows the results.

  As shown in Table 1, from the results of Examples 1 to 4, the bending fatigue-resistant material obtained by crosslinking the composition for a bending fatigue-resistant material containing the inorganic material and the ring-opening copolymer containing the specific structural unit is used. The crosslinked product for use has a larger number of flexures at break and shows a lower static friction coefficient and a lower dynamic friction coefficient than the case where a modified styrene-butadiene copolymer is used instead of the ring-opening copolymer (Comparative Example 1). Was something. When such a crosslinked product for bending fatigue resistant material is used as a bending fatigue resistant material for rubber of car wiper blades, coating materials for hoses, wires and cables, conveyor belts and rubber screens, excellent bending resistance is obtained. It is preferable because it exhibits fatigue properties and a low coefficient of friction.

Claims (7)

  A composition for a bending fatigue-resistant material comprising an inorganic material and a ring-opening copolymer containing a structural unit derived from a monocyclic cycloolefin and a structural unit derived from a norbornene compound.   The composition for a bending fatigue-resistant material according to claim 1, wherein the inorganic material is a carbon material. The composition for a bending fatigue resistant material according to claim 1 or 2, wherein the norbornene compound is a norbornene compound represented by the following general formula (1).

(Wherein, R ^{1 to} R ⁴ represent a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a substituent containing a halogen atom, a silicon atom, an oxygen atom or a nitrogen atom, and R ² and R ³ are They may combine to form a ring structure, and m is 0 or 1.) The flex resistance according to claim 3, wherein R ^{1 to} R ⁴ are a hydrogen atom, a chain hydrocarbon group having 1 to 20 carbon atoms, or a substituent containing a halogen atom, a silicon atom, an oxygen atom, or a nitrogen atom. Composition for fatigue material.   The composition for a flex fatigue-resistant material according to any one of claims 1 to 4, further comprising a rubber other than the ring-opening copolymer.   A crosslinked product for a bending fatigue resistant material obtained by crosslinking the composition for a bending fatigue resistant material according to any one of claims 1 to 5.   A bending fatigue resistant material comprising the composition for a bending fatigue resistant material according to any one of claims 1 to 5 or the crosslinked product for a bending fatigue resistant material according to claim 6.