WO2021230195A1 - Composition - Google Patents

Abstract

A composition containing: (A) a polybutadiene obtained by polymerizing 1,3-butadiene in the presence of 1,2-polybutadiene and a lanthanide-based catalyst; and (B) a thermoplastic resin.

Description

Composition Cross-reference of related applications

This application is based on Japanese Patent Application No. 2020-85535 filed on May 14, 2020, and the contents of the description are incorporated herein by reference.

The present disclosure relates to compositions, and more particularly to compositions containing polybutadiene.

As a method for producing 1,4-polybutadiene, a method of polymerizing 1,3-butadiene in the presence of a catalyst in an inert solvent such as a hydrocarbon is known (for example, Patent Document 1). , 2). Patent Documents 1 and 2 describe cis 1,4-polymerization of 1,3-butadiene in the presence of 1,2-polybutadiene and a cobalt-based catalyst or nickel-based catalyst, followed by 1 of 1,3-butadiene. , 2-It is disclosed that a vinyl cis-polybutadiene rubber is obtained by polymerization.

Japanese Unexamined Patent Publication No. 2008-163144 Japanese Unexamined Patent Publication No. 2017-132954

The crosslinked rubber obtained by cross-linking polybutadiene is required to have excellent crack growth resistance and wear resistance as well as high breaking strength from the viewpoint of product durability, economy, safety and the like. ..

The present disclosure has been made in view of the above problems, and its main purpose is to provide a composition capable of obtaining a crosslinked rubber having excellent crack growth resistance and wear resistance and high breaking strength.

According to the present disclosure, the following compositions are provided in order to solve the above problems.
[1] A composition containing (A) polybutadiene obtained by polymerizing 1,3-butadiene in the presence of 1,2-polybutadiene and a lanthanide-based catalyst, and (B) a thermoplastic resin.
[2] The composition of the above [1], wherein the 1,2-polybutadiene is a polymer obtained by polymerizing 1,3-butadiene in the presence of a cobalt-based catalyst.
[3] The composition of the above [1] or [2], wherein the 1,2-polybutadiene is a 1,2-syndiotactic polybutadiene.
[4] The composition according to any one of the above [1] to [3], further containing at least one filler of carbon black and silica.

According to the composition of the present disclosure, by containing (A) polybutadiene and (B) a thermoplastic resin, it is possible to obtain a crosslinked rubber having excellent crack growth resistance and wear resistance and high breaking strength. ..

Hereinafter, matters related to the aspects of the present disclosure will be described in detail. In addition, in this specification, the numerical value range described by using "-" means that the numerical value described before and after "-" is included as the lower limit value and the upper limit value.

"Composition"
The composition of the present disclosure (hereinafter, also referred to as "the present composition") contains (A) polybutadiene and (B) a thermoplastic resin. Each component will be described in detail below.

<(A) Polybutadiene>
(A) Polybutadiene is a rubber component produced by a method including a step of polymerizing 1,3-butadiene in the presence of 1,2-polybutadiene and a lanthanoid-based catalyst (hereinafter referred to as "step Y"), and 1 , 2-Polybutadiene and 1,4-Polybutadiene. (A) Polybutadiene is preferably produced by a method further comprising a step of obtaining 1,2-polybutadiene (hereinafter referred to as "step X"). Hereinafter, step X and step Y will be described in order. In the present specification, the "rubber component" contained in the composition refers to a polymer capable of obtaining a cured product exhibiting rubber elasticity by thermosetting. This cured product exhibits a property of causing a large deformation (for example, a deformation that expands more than twice when stretched at room temperature) with a small force at room temperature, and rapidly returning to almost the original shape when the force is removed. "Crosslinked rubber" refers to a cured product obtained by thermally curing a rubber component.

<Step X (1, 2 polymerization steps)>
Step X is a step of producing 1,2-polybutadiene by polymerizing 1,3-butadiene in the presence of a cobalt-based catalyst. This step X includes a step of preparing a mixture of 1,3-butadiene and an organic solvent, and a step of polymerizing 1,3-butadiene (more specifically, 1,2 polymerization) in the presence of a cobalt-based catalyst. It includes a step of stopping the polymerization reaction. Hereinafter, the 1,2-polybutadiene obtained by the polymerization reaction in step X is also referred to as “1,2-polybutadiene (X)”. In addition, in this specification, "1,2 polymerization" is the ratio of the monomer unit which the bonding mode of 1,3-butadiene is 1,2 bond in the butadiene polymer produced by the polymerization of 1,3-butadiene. Refers to polymerization in which is more than 50% by mass. The “1,2-polybutadiene” refers to a butadiene polymer in which the proportion of monomer units in which the bonding mode of 1,3-butadiene is 1,2 bonds is more than 50% by mass.

(Preparation process)
The organic solvent used in this step is a solvent containing a hydrocarbon or a halogenated hydrocarbon as a main component. Specific examples of hydrocarbons include saturated aliphatic hydrocarbons having 4 to 10 carbon atoms such as butane, pentane, hexane and heptane; saturated alicyclic hydrocarbons having 6 to 20 carbon atoms such as cyclopentane and cyclohexane; 1-. Monoolefins such as butene and 2-butene; aromatic hydrocarbons such as benzene, toluene and xylene can be mentioned. Specific examples of the halogenated hydrocarbon include methylene chloride, chloroform, carbon tetrachloride, trichlorethylene, perchloroethylene, 1,2-dichloroethane, chlorobenzene, brombenzene, chlorotoluene and the like. Of these, hydrocarbons can be preferably used as the organic solvent. The phrase "mainly composed of a hydrocarbon or a halogenated hydrocarbon" means that the amount of the hydrocarbon or the halogenated hydrocarbon is more than 50% by mass, preferably 70, based on the total amount of the organic solvent used in this step. It is by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

In the mixture of 1,3-butadiene and the organic solvent, the amount of 1,3-butadiene with respect to the total amount of 1,3-butadiene and the organic solvent is preferably 0.5% by mass or more, preferably 2% by mass or more. Is more preferable. The amount of 1,3-butadiene with respect to the total amount of 1,3-butadiene and the organic solvent is preferably 50% by mass or less, more preferably 30% by mass or less, and 15% by mass or less. Is even more preferable. The temperature at which the mixture of 1,3-butadiene and the organic solvent is prepared is preferably 10 to 50 ° C, more preferably 20 to 40 ° C.

(Polymerization process)
In this step, a mixture of 1,3-butadiene and an organic solvent obtained in the above preparation step is used, and in the presence of a cobalt-based catalyst, in an organic solvent containing a hydrocarbon or a halogenated hydrocarbon as a main component 1, 3-butadiene is polymerized by 1 and 2 (more specifically, syndiotactic-1 and 2 polymerization).

The cobalt-based catalyst used contains a cobalt compound. The cobalt compound is preferably a cobalt salt, and specifically, a cobalt halide salt such as cobalt chloride, cobalt bromide, and cobalt iodide; an organic acid cobalt salt such as cobalt octylate, cobalt versatic acid, and cobalt naphthenate. , Etc. can be mentioned. Of these, it is preferable to use an organic acid cobalt salt as the cobalt compound in that it does not contain a halogen atom.

The ratio of the cobalt compound used is preferably such that the molar ratio of 1,3-butadiene (1,3-butadiene / Co) to the cobalt atom of the cobalt compound is 5,000 or more. By setting the 1,3-butadiene / Co (molar ratio) to 5,000 or more, it is preferable in that the molecular weight of 1,2-polybutadiene (X) can be suppressed from becoming too low. The proportion of the cobalt compound used is preferably such that 1,3-butadiene / Co (molar ratio) is 150,000 or less. By setting 1,3-butadiene / Co (molar ratio) to 150,000 or less, it is preferable in that a decrease in polymerization activity can be suppressed. The 1,3-butadiene / Co (molar ratio) is more preferably 10,000 or more. The 1,3-butadiene / Co (molar ratio) is more preferably 100,000 or less.

The cobalt-based catalyst used in step X preferably further contains a phosphine compound and an organoaluminum compound together with the cobalt compound. The phosphine compound is a phosphine compound having one branched aliphatic hydrocarbon group having 3 or more carbon atoms or an alicyclic hydrocarbon group having 5 or more carbon atoms and two aromatic hydrocarbon groups. Is preferable. The branched aliphatic hydrocarbon group having 3 or more carbon atoms is preferably a branched alkyl group having 3 to 10 carbon atoms. The alicyclic hydrocarbon group having 5 or more carbon atoms is preferably a substituted or unsubstituted cycloalkyl group having 5 to 10 carbon atoms. The aromatic hydrocarbon group is preferably a phenyl group.

Preferred specific examples of the phosphine compound include diphenylcyclohexylphosphine, diphenylisopropylphosphine, diphenylisobutylphosphine, diphenylt-butylphosphine, diphenylcyclopentylphosphine, diphenyl (4-methylcyclohexyl) phosphine, diphenylcycloheptylphosphine, diphenylcyclooctylphosphine and the like. Can be mentioned. As the phosphine compound, one type can be used alone or two or more types can be used in combination. The blending ratio of the phosphine compound is preferably 1 to 5 mol, more preferably 1.5 to 4 mol, with respect to 1 mol of the cobalt compound.

Examples of organoaluminum compounds include aluminoxane (methylaminoxane and the like) and compounds formed by contacting trialkylaluminum with water (hereinafter referred to as "aluminum hydride compound"). As the aluminoxane, one synthesized in advance may be used, or one synthesized in a polymerization system may be used. For the aluminum hydride compound, the contact method between trialkylaluminum and water is such that water is contacted with an inert organic solvent solution of trialkylaluminum in any of steam, liquid and solid (ice) states. good. Further, the contact may be carried out as a dissolved state, a dispersed state or an emulsified state in the inert organic solvent, or as a gas state or a mist state existing in the inert gas.

In the cobalt-based catalyst, the ratio of the organoaluminum compound used is preferably such that the molar ratio of 1,3-butadiene (1,3-butadiene / Al) to the aluminum atom of the organoaluminum compound is 500 or more. .. When 1,3-butadiene / Al (molar ratio) is 500 or more, the reaction easily proceeds sufficiently. The proportion of the organoaluminum compound used is preferably such that 1,3-butadiene / Al is 4,000 or less. When 1,3-butadiene / Al (molar ratio) is 4,000 or less, the polymerization activity tends to be high, which is preferable. The amount of 1,3-butadiene / Al is more preferably 800 or more. Further, 1,3-butadiene / Al is more preferably 2,000 or less.

The reaction temperature in 1 and 2 polymerization is usually −20 ° C. to 80 ° C., preferably 10 ° C. to 60 ° C. The reaction time is preferably 5 minutes to 6 hours, more preferably 10 to 3 hours. The polymerization reaction may be a batch type or a continuous type. The concentration of 1,3-butadiene in the reaction solution is usually 5 to 80% by mass, preferably 8 to 25% by mass. Further, in order to prevent the catalyst and the polymer from being inactivated, measures may be taken to suppress the mixing of inactivating compounds such as oxygen, water, or carbon dioxide in the polymerization system.

(Stop process)
In step X, it is preferable to terminate the 1,2 polymerization reaction by adding an organoaluminum compound to the polymerization system after the syndiotactic-1, 2 polymerization reaction reaches a desired reaction conversion rate.

1. Examples of the organoaluminum compound used for stopping the polymerization reaction include an alkylaluminum compound and an aluminum hydride compound. Specific examples of these include alkylaluminum compounds such as trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-t-butylaluminum, and tripentyl. Examples thereof include aluminum, trihexyl aluminum, tricyclohexyl aluminum, and trioctyl aluminum. Specific examples of the aluminum hydride compound include, for example, diethyl aluminum hydride, di-n-propyl aluminum hydride, di-n-butyl aluminum hydride, diisobutyl aluminum hydride, dihexyl aluminum hydride, and diisohexyl aluminum hydride. , Dioctyl aluminum hydride, diisooctyl aluminum hydride and the like. Of these, the organoaluminum compound used for terminating the 1, 2 polymerization reaction is at least one selected from the group consisting of diisobutylaluminum hydride, triethylaluminum, triisobutylaluminum, and diethylaluminum hydride. preferable. As the organoaluminum compound, it can be used alone or in combination of two or more.

When stopping the 1,2 polymerization reaction, the ratio of the organoaluminum compound used is preferably 1 mol or more, more preferably 5 mol or more, per 1 mol of the cobalt compound used in the 1,2 polymerization reaction. The proportion of the organoaluminum compound used is preferably 20 mol or less, and more preferably 15 mol or less, per 1 mol of the cobalt compound used in the 1,2 polymerization reaction. By setting the usage ratio of the organoaluminum compound within the above range, the molecular weight of 1,2-polybutadiene (X) does not become too high, or the molecular weight of 1,4-polybutadiene obtained in step Y does not become too low, which is preferable. Is. The temperature at which the polymerization termination reaction is carried out is usually −20 ° C. to 80 ° C., preferably 10 ° C. to 60 ° C. The reaction conversion rate in the 1,2 polymerization reaction is preferably 50% or more, more preferably 55% or more, still more preferably 60% or more.

According to step X, 1,2-syndiotactic polybutadiene can be produced as 1,2-polybutadiene (X). The melting point of the obtained 1,2-polybutadiene (X) is preferably 60 ° C. or higher, more preferably 100 ° C. or higher, and even more preferably 120 ° C. or higher. The melting point of 1,2-polybutadiene (X) is preferably 150 ° C. or lower, more preferably 145 ° C. or lower, and even more preferably 140 ° C. or lower. By setting the melting point of 1,2-polybutadiene (X) to 60 ° C. or higher, it is preferable in that the low hysteresis loss performance can be sufficiently increased. Further, it is preferable to set the melting point of 1,2-polybutadiene (X) to 150 ° C. or lower in that the processability of the composition can be improved.

For 1,2-polybutadiene (X), the polystyrene-equivalent weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) is preferably 50,000 or more, preferably 70,000 or more. Is more preferable, and 100,000 or more is particularly preferable. The Mw of 1,2-polybutadiene (X) is preferably 500,000 or less, more preferably 400,000 or less, and even more preferably 350,000 or less. When the Mw of 1,2-polybutadiene (X) is 50,000 or more, the rigidity and wear resistance of the crosslinked rubber tend to be sufficiently high, and when it is 500,000 or less, the processability of the composition is improved. It tends to be sufficiently secured.

The content of 1,2-vinyl bond (1,2-vinyl bond content) in 1,2-polybutadiene (X) is preferably 70% or more, more preferably 80% or more, and 90%. It is more preferably more than that, and even more preferably 95% or more. In particular, when the content of the 1,2-vinyl bond is 90% or more, it is preferable in that the low hysteresis loss performance of the crosslinked rubber obtained by using the present composition can be further improved. The 1,2-vinyl bond content is a value measured using an infrared spectrophotometer.

<Step Y (cis-1,4 polymerization step)>
In step Y, 1,4-polybutadiene is produced by polymerizing 1,3-butadiene (cis-1,4 polymerization) in the presence of 1,2-polybutadiene and a lanthanoid-based catalyst. In step Y, it is preferable to use 1,2-polybutadiene (that is, 1,2-polybutadiene (X)) produced by step X as the 1,2-polybutadiene. At this time, the production process can be simplified by adding a lanthanide-based catalyst to the reaction solution obtained in the above step X and adding 1,3-butadiene as necessary to polymerize 1,3-butadiene. It is preferable in order to achieve the conversion. Further, in step Y, by adding isoprene at the time of performing cis-1,4 polymerization, isoprene can be polymerized in addition to 1,3-butadiene. Hereinafter, the 1,4-polybutadiene obtained by the polymerization reaction in step Y is also referred to as "1,4-polybutadiene (Y)".

In addition, in this specification, "cis-1,4 polymerization" means that in the butadiene polymer produced by the polymerization of 1,3-butadiene, the bonding mode of 1,3-butadiene is cis-1,4 bond. Polymerization in which the proportion of monomer units is more than 50% by mass. "1,4-Polybutadiene" means that the ratio of the monomer unit in which the bond mode of 1,3-butadiene is 1,4 bond (including cis-1,4 bond and trans-1,4 bond) is 50% by mass. A super butadiene polymer.

The lanthanoid catalyst used in step Y contains a lanthanoid compound. A lanthanoid compound is a compound having at least one element belonging to a lanthanoid. The lanthanoid compound may be a reaction product of a compound having a lanthanoid and a Lewis base. The lanthanoid contained in the lanthanoid compound is preferably at least one selected from the group consisting of neodymium, praseodymium, cerium, lanthanum, gadolinium and samarium, and neodymium is particularly preferable. Specific examples of the lanthanoid compound include lanthanoid carboxylates, alcoholides, β-diketone complexes, phosphates, phosphites and the like.

Specific examples of the lanthanoid carboxylate include the compound represented by the formula (1); "(R ^1- CO ₂ ) ₃ M" (where M is a lanthanoid and R ¹ has 1 to 20 carbon atoms. It is a monovalent hydrocarbon group.). In the above formula (1), R ¹ is preferably a saturated or unsaturated monovalent chain hydrocarbon group, and is preferably a linear or branched alkyl group or a cycloalkyl group. Carbonyl group in the formula (1), primary which R ¹ has, bonded to secondary or tertiary carbon atom. As M, neodymium, praseodymium, cerium, lanthanum, gadolinium or samarium are preferable, and neodymium is more preferable.

Specific examples of the compound represented by the above formula (1) include octanoic acid, 2-ethylhexanoic acid, oleic acid, stearic acid, benzoic acid, naphthenic acid, and trade name "versatic acid" (manufactured by Shell Chemical Co., Ltd., carboxyl). Examples thereof include salts such as carboxylic acid) whose group is bonded to a tertiary carbon atom. Of these, the compound represented by the above formula (1) is preferably a salt of versatic acid, 2-ethylhexanoic acid or naphthenic acid.

Specific examples of the alkoxide of lanthanoid has the formula ^{(2); (R 2 O} ) compound represented by the ₃ M (however, M is a lanthanoid, ^{R 2} is a monovalent hydrocarbon group having 1 to 20 carbon atoms Is mentioned.). In the above formula (2), ^{examples of R 2} include a monovalent chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. R ² is preferably a monovalent aromatic hydrocarbon group. Specific examples of groups of formula (2) in "R ² O-", for example, 2-ethyl - hexyl alkoxy group, oleyl alkoxy group, stearyl alkoxy group, a phenoxy group, a benzyl alkoxy group. Among these, the group "R ² O-" is 2-ethyl - hexyl alkoxy group, or a benzyl alkoxy group are preferred. The explanation of the above formula (1) is applied to the explanation of M and the preferable example.

Specific examples of the β-diketone complex of the lanthanoid include an acetylacetone complex, a benzoylacetone complex, a propionitrile acetone complex, a valeryl acetone complex, an ethyl acetylacetone complex and the like. Of these, an acetylacetone complex or an ethylacetylacetone complex is preferable.

Specific examples of lanthanoid phosphate or phosphite include bis phosphate (2-ethylhexyl) bis phosphate (1-methylheptyl), bis phosphate (p-nonylphenyl), and bis phosphate (polyethylene glycol). -P-nonylphenyl), phosphoric acid (1-methylheptyl) (2-ethylhexyl), phosphoric acid (2-ethylhexyl) (p-nonylphenyl), 2-ethylhexylphosphonate mono-2-ethylhexyl, 2-ethylhexylphosphon Acids Mono-p-nonylphenyl, bis (2-ethylhexyl) phosphinic acid, bis (1-methylheptyl) phosphinic acid, bis (p-nonylphenyl) phosphinic acid, (1-methylheptyl) (2-ethylhexyl) phosphinic acid , (2-Ethylhexyl) (p-nonylphenyl) Phosphoric acid and the like can be mentioned. Of these, the phosphate or phosphite includes bis phosphate (2-ethylhexyl), bis phosphate (1-methylheptyl), 2-ethylhexylphosphonate mono-2-ethylhexyl or bis (2-ethylhexyl). ) Phosphoric acid salts are preferred.

Of these, the lanthanoid compound used in step Y is preferably a carboxylate or a phosphate, and more preferably a carboxylate. Among these, neodymic phosphate or neodymium carboxylate is more preferable, and neodymic versatic acid salt or neodymium 2-ethylhexanoate is particularly preferable.

In order to solubilize the lanthanoid compound in a solvent or to store it stably for a long period of time, the lanthanoid compound and a Lewis base may be mixed, or the lanthanoid compound and a Lewis base may be reacted to obtain a reaction product. preferable. The amount of the Lewis base used is preferably 0 to 30 mol, more preferably 1 to 10 mol, with respect to 1 mol of the lanthanide contained in the lanthanoid compound. Specific examples of Lewis bases include acetylacetone, tetrahydrofuran, pyridine, N, N-dimethylformamide, thiophene, diphenyl ether, triethylamine, organophosphorus compounds, monovalent or divalent alcohols and the like. In the step Y, one type of lanthanoid compound may be used alone or two or more types may be used in combination.

The ratio of the lanthanoid compound used in the step Y is preferably 0.00001 to 1.0 mmol, preferably 0.0001 to 0.5 mmol, based on 100 g of 1,3-butadiene used in the step Y. Is more preferable. It is preferable that the ratio of the lanthanoid compound used is 0.00001 mmol or more because the polymerization activity can be sufficiently increased. Further, by setting the ratio of the lanthanoid compound to 1.0 mmol or less, it is possible to prevent the catalyst concentration from becoming too high, and it is preferable that a decalcification step is not required.

The lanthanoid catalyst used in step Y preferably further contains an organoaluminum compound and a halogen compound together with the lanthanoid compound.

As the organoaluminum compound, it is preferable to use at least one selected from the group consisting of aluminoxane, an alkylaluminum compound and an aluminum hydride compound. Among these, it is particularly preferable to use at least one compound selected from the group consisting of an alkylaluminum compound and an aluminum hydride compound (hereinafter referred to as "aluminum compound (L)") in combination with aluminoxane.

Preferred specific examples of the aluminoxane used in this step include a compound represented by the following formula (3) and a compound represented by the following formula (4). Also described in Fine Chemicals, 23, (9) 5 (1994), J.Am.Chem.Soc., 115,4971 (1993), and J.Am.Che.Soc., 117,6465 (1995). You may use an aggregate of aluminoxane that is present.

(In formulas (3) and (4), R ³ and R ⁴ are independently monovalent hydrocarbon groups having 1 to 20 carbon atoms, and k and m are independently integers of 2 or more. there. equation (3) a plurality of R ³ in the case of .m is 2 or more identical groups or different groups from each other, a plurality of R ⁴ in the formula (4) is the same group or different groups from each other .)

The R ⁴ in the formula (3) R ³ and the formula in (4), for example a methyl group, an ethyl group, a propyl group, a butyl group, an isobutyl group, t- butyl group, a hexyl group, isohexyl group, octyl Groups, isooctyl groups and the like can be mentioned. Of these, a methyl group, an ethyl group, an isobutyl group or a t-butyl group is preferable, and a methyl group is particularly preferable. k and m are preferably integers of 4 to 100.

Specific examples of the aluminoxane include methylaluminoxane (hereinafter also referred to as “MAO”), ethylaluminoxane, n-propylaluminoxane, n-butylaluminoxane, isobutylaluminoxane, t-butylaluminoxane, hexylaluminoxane, isohexylaluminoxane and the like. Can be done. Among these, MAO is preferable. As the aluminoxane, one type can be used alone or two or more types can be used in combination.

In the preparation of the lanthanoid-based catalyst, the ratio of aluminoxane used shall be such that the amount of aluminum (Al) contained in aluminoxane is 1 to 500 mol with respect to 1 mol of the lanthanoid compound used in the 1,4 polymerization reaction. The amount is preferably 3 to 250 mol, more preferably 5 to 200 mol, and even more preferably 5 to 200 mol. By setting the ratio of using aluminoxane within the above range, it is preferable in that a decrease in catalytic activity is suppressed and a step of removing the catalyst residue does not need to be provided.

Specific examples of the aluminum compound (L) include the alkylaluminum compound and the hydrided aluminum compound exemplified in the description of the stopping step. As the aluminum compound (L), one type may be used alone, or two or more types may be used in combination. Of these, the aluminum compound (L) is preferably at least one selected from the group consisting of diisobutylaluminum hydride, triethylaluminum, triisobutylaluminum, and diethylaluminum hydride. In the preparation of the lanthanoid catalyst, the ratio of the aluminum compound (L) to be used is 1 to 700 mol with respect to 1 mol of the lanthanoid compound used in the 1,4 polymerization reaction. It is preferable to use 3 to 500 mol, and more preferably 3 to 500 mol.

The halogen compound used as one component of the lanthanoid catalyst is preferably a chlorine-containing compound, and more preferably at least one selected from the group consisting of silicon chloride compounds and hydrocarbon compounds. Examples of the silicon chloride compound used include trimethylsilyl chloride, triethylsilyl chloride, dimethylsilyl dichloride and the like. Of these, trimethylsilyl chloride can be preferably used as the silicon chloride compound. Specific examples of the chloride hydrocarbon compound include methyl chloride, butyl chloride, hexyl chloride, octyl chloride, chloroform, dichloromethane, benziliden chloride and the like. Of these, it is preferable to use methyl chloride, chloroform or dichloromethane.

In the preparation of the lanthanoid-based catalyst, the ratio of the halogen compound used is such that the molar ratio of the halogen atom (halogen atom / lanthanoid compound) of the halogen compound to 1 mol of the lanthanoid compound is 0.5 to 3.0. Is preferable, 1.0 to 2.5 is more preferable, and 1.2 to 1.8 is even more preferable. By setting the molar ratio of the halogen atom / lanthanoid compound to 0.5 or more, the polymerization catalytic activity can be sufficiently increased. Further, by setting the molar ratio to 3.0 or less, the halogen compound can be prevented from becoming a catalytic poison.

The reaction temperature at the time of 1,4 polymerization in step Y is preferably −30 ° C. to 200 ° C., more preferably 0 ° C. to 150 ° C. The type of the polymerization reaction is not particularly limited, and it may be carried out by using a batch type reactor or by using a multi-stage continuous type reactor or the like. When the 1,4 polymerization reaction of 1,3-butadiene is carried out using a polymerization solvent, the monomer concentration in the solvent is preferably 5 to 50% by mass, more preferably 7 to 35% by mass. .. From the viewpoint of producing 1,4-polybutadiene and preventing the inactivation of 1,4-polybutadiene having an active terminal, the polymerization system has an inactivating action such as oxygen, water or carbon dioxide. It is preferable to take measures to prevent the contamination of compounds.

By the above 1,4 polymerization reaction, 1,4-polybutadiene having an active terminal can be obtained. For 1,4-polybutadiene (Y), the polystyrene-equivalent weight average molecular weight (Mw) measured by GPC is preferably 50,000 or more, more preferably 100,000 or more, and 150,000 or more. The above is more preferable. The weight average molecular weight (Mw) of 1,4-polybutadiene (Y) is preferably 2,000,000 or less, more preferably 1,500,000 or less, and 1,000,000 or less. Is more preferable. When the weight average molecular weight of 1,4-polybutadiene (Y) is 50,000 or more, the rigidity and wear resistance of the crosslinked rubber tend to be sufficiently high, and when it is 2,000,000 or less, the present composition There is a tendency to ensure sufficient workability of objects.

The content of the cis-1,4 structure in 1,4-polybutadiene (Y) is preferably 70% or more, more preferably 80% or more, further preferably 89% or more, 93. % Or more is even more preferable. In particular, when the content of the cis-1,4 structure is 89% or more, it is preferable in that the crack resistance of the crosslinked rubber obtained by using this composition can be improved. According to the step Y, as the (A) polybutadiene, a mixture of 1,4-polybutadiene (Y) and 1,2-polybutadiene (preferably 1,2-syndiotactic polybutadiene) can be obtained.

In the polybutadiene (A) obtained by the step Y, the content ratio of 1,2-polybutadiene is preferably 3% by mass or more with respect to the total amount of 1,2-polybutadiene and 1,4-polybutadiene. It is more preferably 5% by mass or more, and further preferably 10% by mass or more. Further, the content ratio of 1,2-polybutadiene in (A) polybutadiene is preferably 99% by mass or less, preferably 95% by mass or less, based on the total amount of 1,2-polybutadiene and 1,4-polybutadiene. Is more preferable.

After the cis-1,4 polymerization reaction reaches the desired reaction conversion rate in the above step Y, an antiaging agent (for example, 2,4-di-tert-butyl-p-cresol, 4,6-bis (octyl)). Thiomethyl) -o-cresol, etc.) may be added to the polymerization system to terminate the reaction. Further, after the cis-1,4 polymerization reaction reaches a desired reaction conversion rate, the polymerization terminal of 1,4-polybutadiene having an active terminal may be modified with an alkoxysilane compound. By such a modification reaction, 1,4-polybutadiene having a silicon-containing group derived from an alkoxysilane compound introduced at the polymerization terminal can be obtained.

The alkoxysilane compound used in the modification reaction may be any compound that can react with the active terminal, and is not particularly limited. Examples of the alkoxysilane compound include epoxy group-containing alkoxysilane compounds such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. An isocyanate group-containing alkoxysilane compound such as 3-isocyanuppropyltrimethoxysilane and 3-isoxapropylmethyldiethoxysilane; 3- (meth) acryloyloxypropyltriethoxysilane, 3- (meth) acryloyloxypropylmethyldi. Carbonyl group-containing alkoxysilane compounds such as ethoxysilane; cyano group-containing alkoxysilane compounds such as 3-cyanopropyltriethoxysilane and 3-cyanopropylmethyldiethoxysilane can be mentioned. In addition, "(meta) acrylo" means to include "acrylo" and "methacrylo".

When 1,4-polybutadiene is terminal-modified, the compound that undergoes a condensation reaction with the residue of the alkoxysilane compound introduced at the active terminal and is consumed in the desolubilization step after the modification reaction (hereinafter, also referred to as "condensation catalyst"). ) May be further added. The condensation catalyst used is preferably a condensation catalyst containing at least one element among the elements contained in Group 4A, Group 2B, Group 3B, Group 4B and Group 5B of the Periodic Table, for example, tetramethoxytitanium, tetratert-. Examples thereof include butoxytitanium, bis (n-octanoate) tin, tetraethoxyzirconium and the like.

By removing the solvent from the reaction solution obtained above and isolating the polymer, (A) polybutadiene containing 1,2-polybutadiene and 1,4-polybutadiene can be obtained. (A) Isolation of polybutadiene can be carried out by a known desolvation method such as steam stripping and a drying operation such as heat treatment.

(A) The content of the cis-1,4 bond in the polybutadiene is preferably 1% or more, more preferably 2% or more, and further preferably 5% or more. When the content of the cis-1,4 bond is 1% or more, the crack resistance of the obtained crosslinked product can be further improved. Further, the content of the cis-1,4 bond in (A) polybutadiene is preferably 95% or less, more preferably 90% or less. The content of cis-1,4 bonds is a value measured using an infrared spectrophotometer.

The content of 1 and 2 bonds in (A) polybutadiene is preferably 99% or less, more preferably 98% or less, and even more preferably 95% or less. Further, the content of 1 and 2 bonds in (A) polybutadiene is preferably 5% or more, and more preferably 10% or more. The content of 1 and 2 bonds is a value measured using an infrared spectrophotometer.

(A) The Mooney viscosity (ML1 + 4,100 ° C.) of polybutadiene is preferably 10 or more, and more preferably 20 or more. Further, the Mooney viscosity (ML1 + 4,100 ° C.) of (A) polybutadiene is preferably 150 or less, more preferably 100 or less. (A) When the Mooney viscosity (ML1 + 4,100 ° C.) of polybutadiene is in the above range, the processability of the present composition can be improved and uniform kneading with various compounding agents can be performed, which is preferable. Is. In this specification, the Mooney viscosity (ML1 + 4,100 ° C.) is a value measured according to JIS K6300-1: 2013.

(A) The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) in polybutadiene is preferably 1.1 or more, more preferably 2.0 or more, from the viewpoint of ease of production. 2.2 or more is more preferable. The Mw / Mn of (A) polybutadiene is preferably 4.0 or less, more preferably 3.5 or less. When the Mw / Mn of (A) polybutadiene is 4.0 or less, the fracture characteristics of the crosslinked rubber can be further improved.

In preparing the present composition, the blending ratio of (A) polybutadiene is preferably 30% by mass or more, more preferably 50% by mass or more, and 70% by mass or more with respect to the total amount of the rubber component contained in the present composition. Is more preferable. When the compounding ratio of (A) polybutadiene is in the above range, the crack growth resistance, wear resistance and fracture resistance of the crosslinked rubber can be sufficiently increased, which is preferable.

The content ratio of 1,2-polybutadiene in the present composition is preferably 3% by mass or more with respect to the total amount of the rubber component contained in the present composition from the viewpoint of obtaining a crosslinked rubber having higher crack resistance. 5% by mass or more is more preferable. The content ratio of 1,2-polybutadiene is preferably 30% by mass or less, more preferably 25% by mass or less, based on the total amount of the rubber component contained in the present composition.
The content ratio of 1,4-polybutadiene in the present composition is preferably 70% by mass or more, more preferably 75% by mass or more, based on the total amount of the rubber components contained in the present composition. The content ratio of 1,2-polybutadiene is preferably 97% by mass or less, more preferably 95% by mass or less, based on the total amount of the rubber component contained in the present composition.

<(B) Thermoplastic resin>
The present composition contains (B) a thermoplastic resin. As the thermoplastic resin, styrene resin, polyethylene, C5 resin, C9 resin, C5 / C9 resin, from the viewpoint of obtaining a crosslinked rubber having higher breaking strength, abrasion resistance and crack growth resistance. It is preferably at least one selected from the group consisting of a dicyclopentadiene-based resin, an alkylphenol-based resin, a kumaron-inden resin, and a terpene-phenol resin.

Here, the styrene-based resin is a polymer obtained by using a styrene-based monomer, and among these, the total amount of the monomer units of the styrene-based resin as the structural unit derived from the styrene-based monomer. It is preferable that the polymer has 20% by mass or more based on the amount of the polymer. Examples of styrene-based monomers include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-methoxystyrene, p-tert-butylstyrene, p-phenylstyrene, and o-chloro. Examples thereof include styrene, m-chlorostyrene, p-chlorostyrene and the like. The styrene-based monomer is preferably at least one of styrene and α-methylstyrene.

The styrene-based resin may be a homopolymer obtained by polymerizing one kind of styrene-based monomer, or may be a copolymer obtained by copolymerizing two or more kinds of styrene-based monomers. Further, the styrene-based resin may be a copolymer obtained by using a styrene-based monomer and another monomer copolymerizable with the styrene-based monomer. Other monomers include acrylonitriles such as acrylonitrile and methacrylonitrile, unsaturated carboxylic acids such as acrylics and methacrylic acid; unsaturated carboxylic acid esters such as methyl acrylate and methyl methacrylate; chloroprene and butadiene isoprene. Dienes such as 1-butane, 1-pentene and the like; α, β-unsaturated carboxylic acids such as maleic anhydride or acid anhydrides thereof, and the like.

The softening point of the styrene resin is preferably 30 ° C. or higher, more preferably 60 ° C. or higher, and even more preferably 80 ° C. or higher. When the softening point is 30 ° C. or higher, the effect of improving the crack growth resistance of the crosslinked rubber tends to be further enhanced. The softening point of the styrene resin is preferably 160 ° C. or lower, more preferably 130 ° C. or lower, and even more preferably 100 ° C. or lower. When the softening point is 160 ° C. or lower, the dispersibility of the resin is good, and the crack growth resistance, wear resistance and breaking strength tend to be improved. In the present specification, the softening point of the styrene resin is a value measured using a ring-shaped softening point measuring device according to the method specified in JIS K 6220-1: 2015, and the sample is softened and the sample is sampled. It is the temperature when the ball placed on the bottom plate drops on the bottom plate.

As the styrene resin, a block polymer (thermoplastic elastomer) having a conjugated diene polymer block as a soft segment and a polystyrene block as a hard segment can also be used. When such a thermoplastic block polymer is used, the effect of improving the crack growth resistance can be further enhanced, which is preferable. The conjugated diene-based polymer block contained in the block polymer may be hydrogenated with a part of carbon-carbon double bonds in the structural unit derived from the conjugated diene compound.

Examples of the conjugated diene compound constituting the conjugated diene-based polymer block include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 1,3-hexadiene. Can be mentioned. As the conjugated diene compound, one kind may be used alone or two or more kinds may be used in combination. Among these, the conjugated diene compound is preferably at least one of 1,3-butadiene and isoprene. The content ratio of the conjugated diene unit in the block polymer is preferably 20% by mass or more, more preferably 30% by mass or more. The content ratio of the conjugated diene unit is preferably 80% by mass or less, and more preferably 70% by mass or less.

The content ratio of the polystyrene-based block in the block polymer is preferably 20% by mass or more in that the breaking strength can be further increased. The content ratio of the polystyrene-based block is preferably 80% by mass or less, and more preferably 70% by mass or less. The content ratios of the polystyrene-based block, the conjugated diene-based polymer block, and the conjugated diene unit in the block polymer can be calculated by the integral ratio of ^{1 H-NMR spectrum.}

Specific examples of the block polymer include styrene-butadiene block copolymer, styrene-isoprene block copolymer, epoxidized product of styrene-butadiene block copolymer, styrene-butadiene block copolymer or styrene-isoprene block copolymer. Examples thereof include a block copolymer obtained by hydrogenating a part of the conjugated diene polymer block possessed by the coalescence. More specifically, styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene-butylene-styrene block copolymer (SBBS), and styrene-butadiene-styrene block copolymer epoxy. Examples thereof include compounds and hydrogenated products of these copolymers. As the block polymer, SBS or SIS having a conjugated diene polymer block to which the soft segment is not hydrogenated, or an epoxidized product of a styrene-butadiene-styrene block copolymer is preferably used because it is easily crosslinked. be able to.

Examples of polyethylene include low density polyethylene (LDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE) and the like. The C5-based resin is a solid polymer (C5-based synthetic petroleum resin) obtained by polymerizing a C5 fraction using a Friedel-Crafts type catalyst (AlCl ₃ , BF _{3, etc.).} Specific examples of the C5 resin include a copolymer containing isoprene, cyclopentadiene, 1,3-pentadiene, 1-pentene and the like as main components, a copolymer of 2-pentene and dicyclopentadiene, and 1,3-. Examples thereof include a polymer containing pentadiene as a main component.

The C9-based resin is a solid polymer (C9-based synthetic petroleum resin) obtained by polymerizing a C9 fraction using a Friedel-Crafts type catalyst (AlCl ₃ , BF _{3, etc.).} Specific examples of the C9-based resin include copolymers containing indene, methylinden, vinyltoluene and the like as main components. The C5 / C9-based resin is a solid polymer (C5 / C9-based synthetic petroleum resin) obtained by polymerizing the C5 to C9 fractions using a Friedel-Crafts type catalyst (AlCl ₃ , BF _{3, etc.).} Specific examples of the C5 / C9-based resin include copolymers containing vinyltoluene, indene and the like as main components. As the C5 / C9 resin, a resin having a small amount of C9 or more components is preferable from the viewpoint of compatibility with the rubber component in the present composition. Specifically, in the C5 / C9-based resin, the content of C9 or more in the total amount of the resin is preferably less than 50% by mass, and more preferably 40% by mass or less.

The dicyclopentadiene resin is a petroleum resin using dicyclopentadiene in the C5 fraction as a main raw material. Specific examples of the dicyclopentadiene resin include Maruzen Petrochemical Co., Ltd.'s trade name "Marcarets M" series (M-890A, M-845A, M-990A, etc.). Examples of the alkylphenol-based resin include alkylphenol-acetylene resins such as p-tert-butylphenol-acetylene resin, and alkylphenol-formaldehyde resins having a low degree of polymerization.

Kumaron indene resin is a thermoplastic resin having a kumaron unit and an indene unit as monomer units. The marron indene resin may further have a styrene unit, an α-methylstyrene unit, a methylinden unit, a vinyltoluene unit and the like as monomer units other than the marron unit and the indene unit. Examples of the Kumaron inden resin include those manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., JX Energy Co., Ltd., Nikko Chemical Co., Ltd., and Ruetgers Chemicals Co., Ltd. The terpene phenol resin is a thermoplastic resin having a terpene unit and a phenol unit as a monomer unit. Examples of the terpene phenol resin include those manufactured by Yasuhara Chemical Co., Ltd., Arakawa Chemical Co., Ltd., and Arizona chemical Co., Ltd.

(B) Among these, the thermoplastic resin is styrene-based resin, polyethylene, C5-based resin, C9-based resin, and C5 / C9 in that it can be applied to a wide range of applications and has a high effect of improving crack resistance. It is particularly preferable that the resin is at least one selected from the group consisting of the based resin, the Kumaron inden resin, and the terpene phenol resin.

(B) The blending ratio of the thermoplastic resin is preferably 1 part by mass or more with respect to 100 parts by mass of the rubber component contained in the present composition. (B) Improvement of wear resistance, breaking strength and crack growth resistance by addition of (B) thermoplastic resin in the crosslinked rubber obtained by blending 1 part by mass or more of the thermoplastic resin. The effect can be high enough. The mixing ratio of the thermoplastic resin (B) is more preferably 3 parts by mass or more, and further preferably 5 parts by mass or more with respect to 100 parts by mass of the rubber component. Further, the blending ratio of (B) the thermoplastic resin is preferably 50 with respect to 100 parts by mass of the rubber component contained in the present composition from the viewpoint of maintaining good low hysteresis loss performance of the crosslinked rubber. It is not less than parts by mass, more preferably 30 parts by mass or less, still more preferably 20 parts by mass or less. As the (B) thermoplastic resin, one type may be used alone, or two or more types may be used in combination.

The mixing ratio of (A) polybutadiene and (B) thermoplastic resin was 70 to 99 parts by mass of (A) polybutadiene with respect to 100 parts by mass of the total amount of (A) polybutadiene and (B) thermoplastic resin. B) The thermoplastic resin is preferably 1 to 30 parts by mass. By setting the blending ratio of (A) polybutadiene and (B) thermoplastic resin within the above range, the effect of improving wear resistance, breaking strength and crack growth resistance in a well-balanced manner can be further enhanced. The blending ratio of (A) polybutadiene and (B) thermoplastic resin is 80 to 95 parts by mass of (A) polybutadiene and (B) thermoplastic resin in that the effect of improving breaking strength and abrasion resistance can be further enhanced. Is more preferably 5 to 20 parts by mass, further preferably (A) polybutadiene is 85 to 95 parts by mass, and (B) thermoplastic resin is 5 to 15 parts by mass.

<Other ingredients>
The present composition contains (A) polybutadiene and (B) a thermoplastic resin, but may further contain other components if necessary. The other components can be appropriately selected depending on the intended use of the composition, and examples thereof include inorganic fillers, cross-linking agents, vulcanization accelerators, process oils, and other rubber components.

[Inorganic filler]
Examples of the inorganic filler include silica and carbon black. Examples of silica include wet silica (hydrous silicic acid), dry silica (silicic anhydride), colloidal silica, precipitated silica, calcium silicate, aluminum silicate and the like. Of these, wet silica is preferable. Examples of carbon black include GPF, FEF, HAF, ISAF, SAF, and the like, but the carbon black is not particularly limited. As the inorganic filler, various reinforcing fillers such as clay and calcium carbonate may be blended in addition to silica and carbon black. The present composition preferably contains at least one filler selected from the group consisting of carbon black and silica as the inorganic filler in that the mechanical properties such as the strength and rigidity of the obtained rubber can be enhanced.

The content ratio of the inorganic filler in the present composition is preferably 25 to 130 parts by mass, and more preferably 30 to 110 parts by mass with respect to 100 parts by mass of the total amount of the rubber component contained in the present composition.

[Crosslinking agent]
Examples of the cross-linking agent include organic peroxides, phenolic resins, sulfur, sulfur compounds, p-quinone, p-quinone dioxime derivatives, bismaleimide compounds, epoxy compounds, silane compounds, amino resins, polyols, polyamines, and triazine compounds. Metal soap and the like can be mentioned. Of these, the cross-linking agent is preferably at least one selected from the group consisting of organic peroxides, phenolic resins and sulfur.

Examples of the organic peroxide include 1,3-bis (t-butylperoxyisopropyl) benzene and 2,5-dimethyl-2,5-bis (t-butylperoxy) hexin-3,2,5-dimethyl. -2,5-bis (t-butylperoxy) hexene-3,2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, 2,2'-bis (t-butylperoxy) -P-Isopropylbenzene, dicumyl peroxide, di-t-butyl peroxide, t-butyl peroxide and the like can be mentioned.

Examples of the phenol resin include a p-substituted phenol-based compound represented by the following general formula (8), an o-substituted phenol / aldehyde condensate, an m-substituted phenol / aldehyde condensate, a brominated alkylphenol / aldehyde condensate, and the like. Can be mentioned. Of these, p-substituted phenolic compounds are preferred.

In the above formula (8), X is a hydroxyl group, an alkyl halide group, or a halogen atom, R is a saturated hydrocarbon group having 1 to 15 carbon atoms, and n is an integer of 0 to 10. The p-substituted phenolic compound can be obtained by a condensation reaction between the p-substituted phenol and an aldehyde (preferably formaldehyde) in the presence of an alkaline catalyst.

Commercially available phenolic resins include the trade name "Tackiroll 201" (alkylphenol formaldehyde resin, manufactured by Taoka Chemical Industry Co., Ltd.) and the trade name "Tackiroll 250-I" (brominated alkylphenol formaldehyde resin with a bromization rate of 4%, Taoka Chemical Industry Co., Ltd.). Product name "Tackiroll 250-III" (brominated alkylphenol formaldehyde resin, manufactured by Taoka Chemical Industry Co., Ltd.), Product name "PR-4507" (manufactured by Gunei Chemical Industry Co., Ltd.), Product name "ST137X" (Rohm & Co., Ltd.) Haas), product name "Sumilite Resin PR-22193" (Sumitomo Durez), product name "Tamanor 531" (Arakawa Chemical Industry), product name "SP1059", product name "SP1045", product name Examples thereof include "SP1055", a product name "SP1056" (all manufactured by Skenectadi Co., Ltd.), and a product name "CRM-0803" (manufactured by Showa Union Synthetic Co., Ltd.). Among these, "tacky roll 201" is preferably used.

The amount of the cross-linking agent used is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, based on 100 parts by mass of the total rubber components contained in the present composition. It is more preferably 1 to 10 parts by mass.

When an organic peroxide is used as a cross-linking agent, the amount of the organic peroxide used may be 0.05 to 10 parts by mass with respect to 100 parts by mass of the total rubber components contained in the present composition. It is preferably 0.1 to 5 parts by mass, and more preferably 0.1 to 5 parts by mass. When the amount of the organic peroxide used exceeds 10 parts by mass, the degree of cross-linking tends to be excessively high, the moldability is lowered, and the mechanical properties of the obtained cross-linked rubber tend to be lowered. On the other hand, when the amount of the organic peroxide used is less than 0.05 parts by mass, the degree of cross-linking is insufficient, and the rubber elasticity and mechanical strength of the obtained cross-linked rubber tend to decrease.

When a phenol resin is used as the cross-linking agent, the amount of the phenol resin used is preferably 0.2 to 10 parts by mass with respect to 100 parts by mass of the total rubber components contained in the present composition. It is more preferably 0.5 to 5 parts by mass. When the amount of the phenol resin used exceeds 10 parts by mass, the molding processability tends to decrease. On the other hand, when the amount of the phenol resin used is less than 0.2, the degree of cross-linking is insufficient, and the rubber elasticity and mechanical strength of the obtained cross-linked rubber tend to decrease.

When sulfur is used as the cross-linking agent, the amount of sulfur used is preferably 0.1 to 5 parts by mass, preferably 0.5 to 5 parts by mass, based on 100 parts by mass of the total rubber components contained in the present composition. It is more preferable to use 3 parts by mass.

It is preferable to use at least one of a cross-linking aid and a cross-linking accelerator together with the cross-linking agent because the cross-linking reaction can be carried out gently and uniform cross-linking can be formed. When an organic peroxide is used as the cross-linking agent, sulfur, sulfur compounds (powdered sulfur, colloidal sulfur, precipitated sulfur, insoluble sulfur, surface-treated sulfur, dipentamethylene thiuram tetrasulfide, etc.) and oxime compounds are used as cross-linking aids. (P-quinone oxime, p, p'-dibenzoyl quinone oxime, etc.), Polyfunctional monomers (ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene Glycoldi (meth) acrylate, polyethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, diallyl phthalate, tetraallyloxyethane, triallyl cyanurate, N, N'-m-phenylene bismaleimide, N, It is preferable to use N'-toluylene bismaleimide, maleic anhydride, divinylbenzene, zinc di (meth) acrylate, etc.). Of these, p, p'-dibenzoylquinone oxime, N, N'-m-phenylene bismaleimide, and divinylbenzene are preferable. These can be used alone or in combination of two or more. Since N, N'-m-phenylene bismaleimide exhibits an action as a cross-linking agent, it can also be used alone as a cross-linking agent.

When an organic peroxide is used as the cross-linking agent, the amount of the cross-linking aid used is preferably 10 parts by mass or less with respect to 100 parts by mass in total of the rubber components contained in the present composition. It is more preferably 2 to 5 parts by mass. When the amount of the cross-linking auxiliary used is more than 10 parts by mass, the degree of cross-linking tends to be excessively high, the molding processability is lowered, and the mechanical properties of the obtained cross-linked rubber tend to be lowered.

When a phenol resin is used as the cross-linking agent, a metal halide (strand chloride, ferric chloride, etc.), an organic halide (chlorinated polypropylene, chloroprene rubber, etc.) or the like is used as the cross-linking accelerator for cross-linking. It is preferable because the speed can be adjusted. Further, it is more desirable to use a metal oxide such as zinc oxide or a dispersant such as stearic acid in addition to the cross-linking accelerator.

[Vulcanization accelerator]
The vulcanization accelerator is not particularly limited, and examples thereof include sulfenamide-based, guanidine-based, thiuram-based, thiourea-based, thiazole-based, dithiocarbamic acid-based, and xanthate-based compounds. Specific examples of the sulfide accelerator include 2-mercaptobenzothiazole, dibenzothiazyl disulfide, N-cyclohexyl-2-benzothiazylsulfenamide, Nt-butyl-2-benzothiazolesulfenamide, N. -Oxyethylene-2-benzothiazolesulfenamide, N-oxyethylene-2-benzothiazolesulfenamide, N, N'-diisopropyl-2-benzothiazolesulfenamide, diphenylguanidine, dioltotrilguanidine, orthotril Examples include bisguanidine. The blending amount of the vulcanization accelerator is usually 0.1 to 10 parts by mass, preferably 0.4 to 5 parts by mass with respect to 100 parts by mass of the total amount of the rubber component contained in the present composition. ..

[Process oil]
The present composition may contain a process oil generally used for oil-expanding a polymer as an oil for oil-expanding. The process oil is blended into the composition, for example, by adding the oil directly during the rubber blending. Preferred process oils include various oils known in the art, such as aromatic oils, paraffin oils, naphthenic oils, vegetable oils, and oils with a low content of polycyclic aromatic compounds (low). PCA oil), for example, mild extraction solvate (MES), treated distillate aromatic extract (TDAE), special aromatic extraction from residual oil. Examples include substances (SRAE: special residual aromatic extract) and heavy naphthenic oils. Examples of commercially available MES, TDAE and SRAE are Shellex SNR (heavy paraffin obtained by dewaxing distillate oil with a solvent) as MES, Vivatec 500 manufactured by H & R Wasag AG as TDAE, and Japan Energy Corp as SRAE. NC140 made by. The blending amount of the process oil is preferably 10 to 100 parts by mass with respect to 100 parts by mass of the total amount of the rubber components contained in the present composition.

[Other rubber components]
The present composition may contain a rubber component (other rubber component) different from that of (A) polybutadiene. The type of such other rubber components is not particularly limited, but for example, styrene butadiene rubber (SBR), natural rubber (NR), isoprene rubber (IR), styrene isoprene copolymer rubber, butadiene isoprene copolymer rubber, modified SBR. , Modified or unmodified polybutadiene obtained by a method not including step Y, and the like.

When other rubber components are blended in the present composition, the blending ratio of the other rubber components is preferably 50 parts by mass or less with respect to 100 parts by mass of the total amount of the rubber components contained in the present composition. It is more preferably 30 parts by mass or less, still more preferably 10 parts by mass or less.

In addition to the above-mentioned components, the present composition includes, for example, an antiaging agent, zinc oxide, stearic acid, a softening agent, a silane coupling agent, a compatibilizer, a vulcanization aid, a processing aid, a scorch inhibitor, and a wax. Various additives generally used in rubber compositions such as, etc. can be blended. These blending ratios can be appropriately selected according to various components as long as the effects of the present disclosure are not impaired.

《Bridged body》
This composition prepared by blending (A) polybutadiene and (B) a thermoplastic resin is prepared by using a kneader such as an open kneader (for example, a roll) or a closed kneader (for example, a Banbury mixer). By kneading and cross-linking (vulcanizing) after molding, it can be applied to various rubber products as a cross-linked body. According to this composition, it is possible to produce a crosslinked body having excellent crack growth resistance, wear resistance and strength. Applications of the bridge include, for example, tire applications such as tire tread, under tread, carcass, sidewall, bead part; sealing material such as packing, gasket, weather strip, O-ring; automobile, ship, aircraft, railway, etc. Interior / exterior skin materials for various vehicles; Building materials; Anti-vibration rubbers for industrial machinery and equipment; Various hoses and hose covers such as diaphragms, rolls, radiator hoses, air hoses; Power transmission belts, etc. Belts; O-rings; Dust boots; Medical equipment materials; Gaskets; Insulation materials for electric wires; Applicable to other industrial products.

Hereinafter, the present disclosure will be specifically described based on the examples, but the present disclosure is not limited to these examples. In addition, "part" and "%" in Examples and Comparative Examples are based on mass unless otherwise specified. The method for measuring various physical property values of the polymer is shown below.

[Moony Viscosity]: According to JISK6300-1: 2013, the measurement was performed using an L rotor under the conditions of preheating 1 minute, rotor operating time 4 minutes, and temperature 100 ° C.
[Molecular weight distribution]: A gel permeation chromatograph (trade name; VISCOTEC GPCmax, manufactured by Malvern) was used, and the measurement was performed using a differential refractometer as a detector under the following conditions, and calculated as a standard polystyrene-equivalent value.
Column; Product name "GMHHR-H" (manufactured by Tosoh Corporation) 2 pieces, Column temperature: 38 ° C
Mobile phase; tetrahydrofuran, flow rate; 1.0 ml / min Sample concentration; 10 mg / 20 ml

[Content rate of cis-1,4 bond and content of 1,2-vinyl bond]: Infrared spectrophotometer (trade name; FT / IR-4100 series, manufactured by Jasco) is used, and a ZnSe prism is used. Then, the wave number of 1000 to 600 cm ^-1 was measured.
[1,2-Polybutadiene content]: The content α of 1,2-syndiotactic polybutadiene was calculated according to the following formulas (1) to (4). The abbreviations in the calculation formulas (1) to (4) have the following meanings.
Q1: 1,3-butadiene (for syndiotactic-1,2 polymerization) input amount Q2: 1,2-polybutadiene production amount Q3: 1,2-unreacted 1,3-butadiene amount in polymerization Q4: 1,3- Amount of butadiene (for cis-1,4 polymerization) Q5: 1,4-Polybutadiene production amount Q2 = Q1 × (reaction conversion rate of syndiotactic-1 and 2 polymerization) ... (1)
Q3 = Q1-Q2 ... (2)
Q5 = (Q3 + Q4) × (reaction conversion rate of cis-1,4 polymerization) ... (3)
Content rate α = (Q2 ÷ (Q2 + Q5)) × 100… (4)

1. 1. Production and evaluation of polybutadiene rubber [Production Example 1]
1.5 kg of cyclohexane and 50 g of 1,3-butadiene were placed in a nitrogen-substituted 3 L autoclave. Separately, a dichloride solution containing 0.02 mmol of cobalt chloride, a dichloride solution containing 0.04 mmol of diphenylcyclohexylphosphine, and a toluene solution containing 0.60 mmol of methylaluminoxane (MAO) were mixed. The catalyst composition A was prepared by reacting at 30 ° C. for 60 minutes. This catalyst composition A was put into the above autoclave and reacted at 30 ° C. for 1 hour (syndiotactic-1 and 2 polymerization) to obtain a polymer solution. The reaction conversion rate of the added 1,3-butadiene was about 75%. Then, in order to stop the polymerization reaction, a toluene solution containing 0.2 mmol of diisobutylaluminum hydride was put into the autoclave and stirred for 15 minutes.

In order to measure various physical properties of polybutadiene obtained by the above reaction, 18 g of the polymer solution was extracted from the above polymer solution, and the extracted polymer solution contained 2,6-di-t-butyl-p-cresol. A toluene solution was added to terminate the polymerization reaction. Then, the solvent was removed by heating on a hot plate. When various physical property values of the obtained polybutadiene (1,2-syndiotactic polybutadiene) were measured, the melting point was 137 ° C. and the weight average molecular weight (Mw) was 140,000.

Subsequently, 250 g of 1,3-butadiene was added to the obtained polymer solution. Separately, a cyclohexane solution containing 0.037 mmol of neodymium versatic acid (Nd (ver) ₃ ), a toluene solution containing 1.20 mmol of MAO, and a toluene solution containing 2.86 mmol of diisobutylaluminum hydride. , And a toluene solution containing 0.045 mmol of trimethylsilyl chloride (Me ₃ SiCl) was reacted with 1,3-butadiene 4.5 mmol at 30 ° C. for 60 minutes to prepare the catalyst composition B. This catalyst composition B was put into the above autoclave and reacted at 70 ° C. for 1 hour (cis-1,4 polymerization) to obtain a polymer solution. The reaction conversion rate of the added 1,3-butadiene was almost 100%.

Next, in order to measure various physical properties of the polybutadiene obtained by the above reaction, 200 g of the polymer solution was extracted from the above polymer solution, and 2,4-di-tert-butyl-p-cresol was added to the extracted polymer solution. A toluene solution containing 1.5 g was added to terminate the polymerization reaction. Then, it was desolvated by steam stripping and dried on a roll at 110 ° C. The obtained dried product was designated as polybutadiene P1. When various physical property values of polybutadiene P1 were measured, the 1,2-polybutadiene content was 11%, the 1,4-polybutadiene content was 89%, the Mooney viscosity (ML1 + 4,100 ° C.) was 57, and the weight average molecular weight (Mw). The molecular weight distribution (Mw / Mn) was 3.14, the content of cis-1,4 bond was 87.6%, and the content of 1,2-vinyl bond was 11.1%.

2. 2. Preparation and evaluation of rubber composition [Example 1]
For 100 parts of polybutadiene P1 of Production Example 1, 10 parts of SIS (JSR SIS5250 (styrene content 20%) manufactured by JSR), 70 parts of silica (trade name "ULTRASIL 360", manufactured by Ebonic), carbon black (product). Name "Dia Black N339", manufactured by Mitsubishi Chemical Co., Ltd.) 5 parts, T-DAE process oil 10 parts, silane coupling agent (trade name "Si69", manufactured by Ebonic) 3.6 parts, stearic acid 2 parts, anti-aging Agent (trade name "Nocrack 810NA", manufactured by Ouchi Shinko Chemical Industry Co., Ltd.), zinc oxide 3 parts, vulture accelerator CZ (trade name "Noxeller CZ-G", manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) 1. 8 parts, vulture accelerator D (trade name "Noxeller D", manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.) 1.5 parts, and sulfur 1.5 parts are mixed and kneaded using a plast mill to form a rubber composition. I got something. Then, this rubber composition was vulcanized at 160 ° C. for 12 minutes to obtain a vulcanized rubber. Evaluation of various properties of the obtained vulcanized rubber was performed by the evaluation methods (1) to (3) shown below. The formulation and evaluation results are shown in Table 1 below.

(1) Crack growth resistance A crosslinked rubber sheet having a thickness of 2 mm is formed by molding the obtained rubber composition into a sheet by calendar processing and then vulcanizing it at 160 ° C. for a predetermined time using a vulcanization press machine. Was produced. By punching the obtained sheet, a test piece made of the IV type dumbbell described in ASTM D638 was prepared. At this time, the sheet was punched so that the longitudinal direction of the dumbbell was the columnar direction of the sheet, and a crack extending in the anti-columnar direction was formed at the center position of the dumbbell in the longitudinal direction.
The obtained test piece was subjected to a constant elongation fatigue test under the conditions of an elongation rate of 100%, a measurement temperature of 23 ° C., and a rotation speed of 300 cpm, and the number of cycles until the test piece broke was measured. It is shown as an index with Comparative Example 1 as 100, and the larger the value, the better the crack resistance.
(2) Breaking strength In accordance with JIS K6251: 2010, a No. 3 dumbbell type test piece made of a test vulcanized rubber sheet was prepared and used as a test piece for evaluation. Using a tensile tester (model name "AG-2000", manufactured by Shimadzu Corporation), the sample piece was pulled at a load speed of 500 mm / min to determine the breaking strength (TB). It is shown as an index with Comparative Example 1 as 100, and the larger the value, the higher the intensity.
(3) Abrasion resistance Using a vulcanized rubber as a measurement sample, a DIN wear tester (manufactured by Toyo Seiki Co., Ltd.) was used, and the measurement was performed at 25 ° C. with a load of 10 N in accordance with JIS K 6264-2: 2005. It is displayed as an index with Comparative Example 1 as 100, and the larger the value, the better the wear resistance.

[Examples 2 to 6 and Comparative Examples 1 to 6]
A rubber composition was obtained by kneading in the same manner as in Example 1 except that the compounding formulation was changed to the formulations shown in Tables 1 and 2 below. Further, a vulcanized rubber was produced using the obtained rubber composition in the same manner as in Example 1, and the physical properties were evaluated. The results are shown in Tables 1 and 2 below.

The abbreviations and components in Tables 1 and 2 indicate that the following are used.
P1: Polybutadiene BR01 of Production Example 1: JSR BR01 manufactured by JSR (polybutadiene rubber, content of cis-1,4 bond 95%)
RB840: JSR RB840 (Syndiotactic 1,2-polybutadiene) manufactured by JSR Corporation
SIS: JSR SIS5250 manufactured by JSR (styrene content 20%)
Epoxy SBS: Epofriend A102 manufactured by Daicel Chemical Co., Ltd. (styrene content 40%)
Polyethylene: KS340T manufactured by Japan Polyethylene Corporation
Terpene phenol resin: Tamanol 901 manufactured by Arakawa Chemical Industry Co., Ltd.
Kumaron Inden Resin: NOBARES C90 manufactured by Ruetgers
C5 / C9 resin: T-REZ PR802 manufactured by JXTG Energy Co., Ltd.
Silica 1: Evonik ULTRASIL 360
Silica 2: ULTRASIL VN3 manufactured by Evonik Industries
Carbon Black N339: Mitsubishi Chemical Corporation Dia Black N339
Silane coupling agent: Evonik Si69
Anti-aging agent: Nocrack 810NA manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.
Vulcanization accelerator CZ: Noxeller CZ-G manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.
Vulcanization accelerator D: Noxeller D manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.
In the table, "-" indicates that the compound in the corresponding column was not used.

(A) Examples 1 to 6 in which a rubber composition was prepared using polybutadiene, and Comparative Examples 1 to 6 in which a high cis polybutadiene rubber and syndiotactic 1,2-polybutadiene were blended as a polybutadiene component to prepare a rubber composition. Example 1 and Comparative Example 1, Example 2 and Comparative Example 2, Example 3 and Comparative Example 3, Example 4 and Comparative Example 4, and Example 5 and Comparative Example 5 having the same composition except for polybutadiene. Comparing Example 6 and Comparative Example 6, as shown in Tables 1 and 2, the vulcanized rubbers of Examples 1 to 6 all have crack growth resistance, breaking strength and breaking strength as compared with Comparative Examples. It had excellent wear resistance.

From the above results, it was clarified that the crosslinked rubber having excellent crack growth resistance, breaking strength and wear resistance can be obtained according to this composition.

Claims (7)

1. (A) Polybutadiene obtained by polymerizing 1,3-butadiene in the presence of 1,2-polybutadiene and a lanthanide-based catalyst, and
   (B) Thermoplastic resin and
   A composition containing.
2. The composition according to claim 1, wherein the 1,2-polybutadiene is a polymer obtained by polymerizing 1,3-butadiene in the presence of a cobalt-based catalyst.
3. The composition according to claim 1 or 2, wherein the 1,2-polybutadiene is 1,2-syndiotactic polybutadiene.
4. The composition according to any one of claims 1 to 3, wherein the (B) thermoplastic resin has a structural unit derived from a styrene-based monomer.
5. The composition according to claim 4, wherein the (B) thermoplastic resin is a thermoplastic elastomer.
6. The (B) thermoplastic resin is selected from the group consisting of polyethylene, C5 resin, C9 resin, C5 / C9 resin, dicyclopentadiene resin, alkylphenol resin, kumaron inden resin, and terpenphenol resin. The composition according to any one of claims 1 to 3, which is at least one kind.
7. The composition according to any one of claims 1 to 6, further comprising at least one filler of carbon black and silica.