WO2021020189A1 - Polymer composition, crosslinked polymer and tire - Google Patents

Abstract

The present invention provides a polymer composition which has good processability and is suitable for the production of a tire that has a good balance between break strength and wear resistance.　A polymer composition according to the present invention contains: (A) a conjugated diene polymer which is a polymer of a conjugated diene compound or a copolymer of a conjugated diene compound and an aromatic vinyl compound, and which is a reaction product of an active polymerization end and a compound represented by one of general formulae (1) to (4); and (B) a carbon black having a nitrogen adsorption specific surface area (N₂SA) of from 75 m²/g to 130 m²/g. This polymer composition contains from 30 parts by mass to 80 parts by mass of the carbon black (B) relative to 100 parts by mass of the polymer component contained in this polymer composition.

Description

Polymer compositions, crosslinked polymers, and tires

The present invention relates to a polymer composition, a crosslinked polymer, and a tire produced by using the crosslinked polymer.

In recent years, there has been an increasing demand for fuel efficiency of automobiles in connection with the movement of global carbon dioxide emission regulations accompanying the growing interest in environmental issues. In order to meet such demands, reduction of rolling resistance is also required for tire performance. Conventionally, a method of optimizing the tire structure has been studied as a method of reducing the rolling resistance of the tire, but the polymer composition applied to the tire has a low tan δ (hereinafter, also referred to as “low loss property”). .), The use of a material having excellent low heat generation is also currently practiced as a general method.

As a method for obtaining such a polymer composition having low heat generation, it is conceivable to reduce the amount of filler such as carbon black or silica, or to use carbon black having a large particle size. In either method, the polymer composition It is inevitable that the reinforcing property, abrasion resistance and grip property on a wet road surface (hereinafter, also referred to as "wet grip property") will be deteriorated.

Therefore, for example, studies have been made on using a modified conjugated diene-based polymer in which an active polymer having a metal end is formed and modified by introducing a specific modifier into the active polymer as a tread material for a tire. (See, for example, Patent Document 1). Patent Document 1 discloses that when this material is used as a tread material for a tire, it is excellent in heat generation, wear resistance, and wet grip.

Special Table 2016-528369

However, when the modified conjugated diene polymer disclosed in Patent Document 1 is used as a tread material for a tire, the dispersibility of fillers such as carbon black and silica contained in the polymer composition is not very good, and the polymer is broken. There is a problem that it is difficult to obtain sufficient performance in terms of strength and wear resistance.

Therefore, some aspects of the present invention provide a polymer composition suitable for producing a tire which has good workability and is highly balanced in breaking strength and wear resistance. In addition, some aspects of the present invention provide a tire that is highly balanced in breaking strength and wear resistance.

The present invention has been made to solve at least a part of the above-mentioned problems, and can be realized as the following aspects.

One aspect of the polymer composition according to the present invention is
(A) A polymer of a conjugated diene compound or a copolymer of a conjugated diene compound and an aromatic vinyl compound, which comprises an active polymerization terminal and a compound represented by any of the following general formulas (1) to (4). Conjugated diene-based polymer, which is a reactant,
(B) Carbon black having a nitrogen adsorption specific surface area (N ₂ SA) of 75 m ² / g or more and 130 m ² / g or less.
Contains,
The carbon black (B) is contained in an amount of 30 parts by mass or more and 80 parts by mass or less with respect to 100 parts by mass of the polymer component contained in the polymer composition.

(In formula (1), A ¹ is a monovalent group bonded to L ¹ with an imino group, an amide group, a (thio) carbonyl group, a (thio) carbonyloxy group, a sulfide or a polysulfide, or is protected. Primary amino group, protected secondary amino group, tertiary amino group, nitrile group, pyridyl group, (thio) epoxy group, (thio) isocyanate group, (thio) formyl group, (thio) carboxylic acid ester, (Thio) Represents a metal salt of a carboxylic acid ester, a carboxylic acid halogen compound or an imidazolyl group, L ¹ represents a hydrocarbylene group having 1 to 20 carbon atoms, and R ¹ and R ² independently represent 1 to 4 carbon atoms. Represents the hydrocarbyl group of, n1 is 0 or 1.)

(In formula (2), A ² is a monovalent group bonded to L ² with an imino group, an amide group, a (thio) carbonyl group, a (thio) carbonyloxy group, a sulfide or a polysulfide, or is protected. Primary amino group, protected secondary amino group, tertiary amino group, nitrile group, pyridyl group, (thio) epoxy group, (thio) isocyanate group, (thio) formyl group, (thio) carboxylic acid ester, (Thio) Represents a metal salt of a carboxylic acid ester, a carboxylic acid halogen compound, an imidazolyl group, or a group represented by the following formula (2a), and L ² and L ³ are independently single-bonded or hydro having 1 to 20 carbon atoms, respectively. It represents a carbylene group, R ³ and R ⁴ each independently represent a hydrocarbyl group having 1 to 4 carbon atoms, n2 is 0 to 3, and m1 is 0 or 1.)

(In formula (2a), L ³ , R ³ , R ⁴ and n 2 are the same as in formula (2), and * indicates a site that binds to L ^2. )

(In the formula (3), A ³ are each independently, an imino group, an amido group, (thio) carbonyl group, a (thio) carbonyl group, secondary amino group, or a tertiary amino group, Z is a nitrogen atom Represents a t-valent group having 1 to 20 carbon atoms including or not containing, L ⁴ represents a single bond or a hydrocarbylene group having 1 to 20 carbon atoms, and L ⁵ represents a hydrocarbylene group having 1 to 20 carbon atoms. R ⁵ and R ⁶ each independently represent a hydrocarbyl group having 1 to 4 carbon atoms, n3 is 0 or 1, and t is 2 or 3).

(In the formula (4), R ⁷ and R ⁸ each independently represent a hydrocarbyl group having 1 to 20 carbon atoms, and R ⁹ is a hydrocarbyl group having 1 to 20 carbon atoms, a hydrogen atom contained in the alkyl group, and -CH. _At least one of 2-is a substituted alkyl group having 1 to 20 carbon atoms substituted with a group containing at least one element selected from the group consisting of silicon, nitrogen, phosphorus, oxygen and sulfur, or nitrogen. , An aromatic group having 6 to 20 carbon atoms containing at least one element selected from the group consisting of phosphorus, oxygen and sulfur, R ¹⁰ represents an alkanediyl group having 1 to 20 carbon atoms, and n4 represents an alkanediyl group having 1 to 20 carbon atoms. 1 or 2)

In any aspect of the polymer composition
The polystyrene-equivalent weight average molecular weight of the conjugated diene polymer (A) measured by gel permeation chromatography can be 100,000 to 2,000,000.

In any aspect of the polymer composition,
Furthermore, a cross-linking agent can be contained.

One aspect of the crosslinked polymer according to the present invention is
It is produced by using the polymer composition of any one of the above embodiments.

One aspect of the tire according to the present invention is
It is the one using the crosslinked polymer of the said aspect.

According to the polymer composition according to the present invention, it is possible to produce a crosslinked polymer (tire) having a highly balanced breaking strength and wear resistance.

Hereinafter, preferred embodiments according to the present invention will be described in detail. It should be noted that the present invention is not limited to the embodiments described below, but should be understood to include various modifications implemented without changing the gist of the present invention.

In the present specification, the numerical range described as "A to B" is interpreted as including the numerical value A as the lower limit value and the numerical value B as the upper limit value.

In the present specification, "(meth) acrylic acid-" is a concept including both acrylic acid-and methacrylic acid-.

1. 1. Polymer composition The polymer composition according to the present embodiment is (A) a polymer of a conjugated diene compound or a copolymer of a conjugated diene compound and an aromatic vinyl compound, and has an active polymerization terminal and the following general formula (1). ) To (4), a conjugated diene polymer, which is a reaction product with the compound represented by any of (4), and (B) nitrogen adsorption specific surface area (N ₂ SA) of 75 m ² / g or more and 130 m ² / g or less. Contains carbon black and.

The polymer composition according to the present embodiment is an unvulcanized polymer composition obtained by kneading (A) conjugated diene-based polymer and (B) carbon black with other additives if necessary. It is a thing. The polymer composition according to the present embodiment forms a crosslinked polymer by subjecting it to a crosslinking treatment such as vulcanization.

Hereinafter, each component contained in the polymer composition according to the present embodiment will be described.

1.1. (A) Conjugated Diene Polymer The polymer composition according to the present embodiment is (A) a polymer of a conjugated diene compound or a copolymer of a conjugated diene compound and an aromatic vinyl compound, and has an active polymerization terminal and the following. A conjugated diene-based polymer which is a reaction product with a compound represented by any of the general formulas (1) to (4) (in the present specification, it is also simply referred to as "(A) conjugated diene-based polymer"). Contains.

(In formula (1), A ¹ is a monovalent group bonded to L ¹ with an imino group, an amide group, a (thio) carbonyl group, a (thio) carbonyloxy group, a sulfide or a polysulfide, or is protected. Primary amino group, protected secondary amino group, tertiary amino group, nitrile group, pyridyl group, (thio) epoxy group, (thio) isocyanate group, (thio) formyl group, (thio) carboxylic acid ester, (Thio) Represents a metal salt of a carboxylic acid ester, a carboxylic acid halogen compound or an imidazolyl group, L ¹ represents a hydrocarbylene group having 1 to 20 carbon atoms, and R ¹ and R ² independently represent 1 to 4 carbon atoms. Represents the hydrocarbyl group of, n1 is 0 or 1.)

(In formula (2), A ² is a monovalent group bonded to L ² with an imino group, an amide group, a (thio) carbonyl group, a (thio) carbonyloxy group, a sulfide or a polysulfide, or is protected. Primary amino group, protected secondary amino group, tertiary amino group, nitrile group, pyridyl group, (thio) epoxy group, (thio) isocyanate group, (thio) formyl group, (thio) carboxylic acid ester, (Thio) Represents a metal salt of a carboxylic acid ester, a carboxylic acid halogen compound, an imidazolyl group, or a group represented by the following formula (2a), and L ² and L ³ are independently single-bonded or hydro having 1 to 20 carbon atoms, respectively. It represents a carbylene group, R ³ and R ⁴ each independently represent a hydrocarbyl group having 1 to 4 carbon atoms, n2 is 0 to 3, and m1 is 0 or 1.)

(In formula (2a), L ³ , R ³ , R ⁴ and n 2 are the same as in formula (2), and * indicates a site that binds to L ^2. )

(In the formula (3), A ³ are each independently, an imino group, an amido group, (thio) carbonyl group, a (thio) carbonyl group, secondary amino group, or a tertiary amino group, Z is a nitrogen atom Represents a t-valent group having 1 to 20 carbon atoms including or not containing, L ⁴ represents a single bond or a hydrocarbylene group having 1 to 20 carbon atoms, and L ⁵ represents a hydrocarbylene group having 1 to 20 carbon atoms. R ⁵ and R ⁶ each independently represent a hydrocarbyl group having 1 to 4 carbon atoms, n3 is 0 or 1, and t is 2 or 3).

(In the formula (4), R ⁷ and R ⁸ each independently represent a hydrocarbyl group having 1 to 20 carbon atoms, and R ⁹ is a hydrocarbyl group having 1 to 20 carbon atoms, a hydrogen atom contained in the alkyl group, and -CH. _At least one of 2-is a substituted alkyl group having 1 to 20 carbon atoms substituted with a group containing at least one element selected from the group consisting of silicon, nitrogen, phosphorus, oxygen and sulfur, or nitrogen. , An aromatic group having 6 to 20 carbon atoms containing at least one element selected from the group consisting of phosphorus, oxygen and sulfur, R ¹⁰ represents an alkanediyl group having 1 to 20 carbon atoms, and n4 represents an alkanediyl group having 1 to 20 carbon atoms. 1 or 2)

(A) The conjugated diene-based polymer has a structural unit derived from the conjugated diene compound, and has a structure derived from any of the compounds of the above general formulas (1) to (4) at the active polymerization terminal. In such a (A) conjugated diene-based polymer, first, a monomer containing a conjugated diene compound is polymerized to obtain a polymer having an active terminal (polymerization step), and then a polymer having an active terminal is obtained. , Can be obtained by reacting with any of the compounds of the above general formulas (1) to (4) (hereinafter, also referred to as "specific modifier") (modification step).

<Polymerization process>
Examples of the conjugated diene compound that can be used in the polymerization include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, and 1,3-heptadiene. , 2-Phenyl-1,3-butadiene, 3-methyl-1,3-pentadiene, 2-chloro-1,3-butadiene and the like. Among these, 1,3-butadiene, isoprene and 2,3-dimethyl-1,3-butadiene are preferable. The conjugated diene compound may be used alone or in combination of two or more.

The conjugated diene-based polymer (A) may be a homopolymer of the conjugated diene compound, but from the viewpoint of increasing the strength of the crosslinked polymer, it must be a copolymer of the conjugated diene compound and an aromatic vinyl compound. Is preferable. Above all, a copolymer containing 1,3-butadiene and styrene in a monomer composition is preferable in terms of high living property in anionic polymerization. When the (A) conjugated diene-based polymer is a copolymer of a conjugated diene compound and an aromatic vinyl compound, the (A) conjugated diene-based polymer is typically a conjugated diene compound and an aromatic vinyl compound. It may have a random copolymerized moiety having an irregular distribution of, and further have a block moiety composed of structural units derived from a conjugated diene compound or an aromatic vinyl compound.

Examples of the aromatic vinyl compound that can be used in the polymerization include styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, and the like. 5-tert-Butyl-2-methylstyrene, vinylethylbenzene, divinylbenzene, trivinylbenzene, divinylnaphthalene, tert-butoxystyrene, vinylbenzyldimethylamine, (4-vinylbenzyl) dimethylaminoethyl ether, N, N-dimethyl Aminoethyl styrene, N, N-dimethylaminomethyl styrene, 2-ethyl styrene, 3-ethyl styrene, 4-ethyl styrene, 2-tert-butyl styrene, 3-tert-butyl styrene, 4-tert-butyl styrene, vinyl Examples thereof include xylene, vinylnaphthalene, vinylpyridine, diphenylethylene, tertiary amino group-containing diphenylethylene (for example, 1- (4-N, N-dimethylaminophenyl) -1-phenylethylene, etc.). Among these, styrene and α-methylstyrene are preferable. Aromatic vinyl compounds may be used alone or in combination of two or more.

(A) When the conjugated diene polymer is a copolymer of a conjugated diene compound and an aromatic vinyl compound, the content of the aromatic vinyl compound (aromatic vinyl content) is the low loss property of the obtained crosslinked polymer. From the viewpoint of improving the balance between the wet grip and the wet grip property, the content is preferably 3 to 55% by mass, preferably 5 to 50% by mass, based on 100% by mass of the total of the conjugated diene compound and the aromatic vinyl compound used for the polymerization. It is more preferable to do so. The aromatic vinyl content of the conjugated diene polymer (A) can be measured by ^{1 1} H-NMR.

In the polymerization, a monomer other than the conjugated diene compound and the aromatic vinyl compound may be used. Examples of other monomers include acrylonitrile, methyl (meth) acrylate, ethyl (meth) acrylate, hydroxyethyl (meth) acrylate and the like. The amount of the other monomer used is preferably 25% by mass or less, more preferably 15% by mass or less, and preferably 10% by mass or less, based on 100% by mass of the total amount of the monomers used for the polymerization. Especially preferable.

As the polymerization method to be used, any of a solution polymerization method, a gas phase polymerization method and a bulk polymerization method may be used, but the solution polymerization method is particularly preferable. Further, as the polymerization type, either a batch type or a continuous type may be used. When the solution polymerization method is used, as an example of a specific polymerization method, a monomer containing a conjugated diene compound is polymerized in an organic solvent in the presence of a polymerization initiator and a randomizer used if necessary. The method can be mentioned.

As the polymerization initiator, an alkali metal compound or an alkaline earth metal compound can be used. Specific examples of these include alkyllithium such as methyllithium, ethyllithium, n-propyllithium, n-butyllithium, sec-butyllithium and tert-butyllithium, 1,4-dilithiobtan, phenyllithium and stillbenlithium. Naphthyllithium, 1,3-bis (1-lithio-1,3-dimethylpentyl) benzene, 1,3-phenylenebis (3-methyl-1-phenylpentylidene) dilithium, 3- (dimethylamino) propyllithium, Examples thereof include sodium naphthyl, potassium naphthyl, di-n-butyllithium, di-n-hexylmagnesium, ethoxypotassium, calcium stearate and the like. Of these, lithium compounds are preferred. The total amount of the polymerization initiator used is preferably 0.2 to 20 mmol with respect to 100 g of the monomer used for the polymerization. The polymerization initiator may be used alone or in combination of two or more.

Further, the polymerization reaction is carried out in the presence of a compound obtained by mixing an alkali metal compound or an alkaline earth metal compound with a compound having a functional group that interacts with silica (hereinafter, also referred to as "modification initiator"). You may go with. By carrying out the polymerization in the presence of a modification initiator, a functional group that interacts with silica can be introduced into the polymerization initiation terminal of the (A) conjugated diene-based polymer. In addition, in this specification, "interaction" means an intermolecular force which forms a covalent bond between molecules or is weaker than a covalent bond (for example, ion-dipole interaction, dipole-dipole interaction, etc. It means forming an electromagnetic force acting between molecules such as a hydrogen bond and a van der Waals force. The "functional group that interacts with silica" preferably has at least one selected from the group consisting of nitrogen atoms, sulfur atoms, phosphorus atoms and oxygen atoms.

The modification initiator is preferably a reaction product of a lithium compound such as alkyllithium and a nitrogen-containing compound such as a secondary amine compound. Specific examples of the nitrogen-containing compound include, for example, dimethylamine, diethylamine, dipropylamine, dibutylamine, dodecamethyleneimine, N, N'-dimethyl-N'-trimethylsilyl-1,6-diaminohexane, piperidine, pyrrolidine, and the like. Hexamethylene imine, heptamethylene imine, dicyclohexylamine, N-methylbenzylamine, di- (2-ethylhexyl) amine, diallylamine, morpholin, N- (trimethylsilyl) piperazine, N- (tert-butyldimethylsilyl) piperazine, 1, Examples thereof include 3-ditrimethylsilyl-1,3,5-triazinan. When polymerization is carried out in the presence of a modification initiator, a modification initiator is prepared by previously mixing an alkali metal compound or an alkaline earth metal compound with a compound having a functional group that interacts with silica. The prepared modification initiator may be added to the polymerization system to carry out the polymerization. Alternatively, an alkali metal compound or alkaline earth metal compound and a compound having a functional group that interacts with silica are added to the polymerization system, and both are mixed in the polymerization system to prepare a modification initiator. Polymerization may be carried out. Alternatively, a nitrogen-containing alkyllithium compound can also be used. As a specific example of the nitrogen-containing alkyllithium compound, a reaction product of 3-dimethylaminopropyllithium and isoprene can be used.

The randomizer can be used for the purpose of adjusting the vinyl bond content, which represents the content of vinyl bonds (1,2-bonds and 3,4-bonds) in the polymer. Examples of randomizers include dimethoxybenzene, tetrahydrofuran, dimethoxyethane, diethylene glycol dibutyl ether, diethylene glycol dimethyl ether, 2,2-di (tetrahydrofuryl) propane, 2- (2-ethoxyethoxy) -2-methylpropane, triethylamine, pyridine. , N-Methylmorpholine, tetramethylethylenediamine and the like. These can be used alone or in combination of two or more.

The organic solvent used for the polymerization may be any organic solvent that is inert to the reaction, and for example, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons and the like can be used. Of these, hydrocarbons having 3 to 8 carbon atoms are preferable, and specific examples thereof include propane, n-butene, isobutane, n-pentane, isopentane, n-hexane, cyclohexane, propene, 1-butene, isobutene, and trans-. 2-Butene, cis-2-butene, 1-pentyne, 2-pentyne, 1-hexene, 2-hexene, benzene, toluene, xylene, ethylbenzene, heptane, cyclopentane, methylcyclopentane, methylcyclohexane, 1-pentene, 2-Pentyne, cyclohexene and the like can be mentioned. As the organic solvent, one type can be used alone or two or more types can be used in combination.

When solution polymerization is used, the monomer concentration in the reaction solvent is preferably 5 to 50% by mass, preferably 10 to 30% by mass, from the viewpoint of maintaining a balance between productivity and ease of polymerization control. More preferred. The temperature of the polymerization reaction is preferably −20 ° C. to 150 ° C., more preferably 0 ° C. to 120 ° C., and particularly preferably 20 ° C. to 100 ° C. Further, it is preferable that the polymerization reaction is carried out under a pressure sufficient to keep the monomer substantially in the liquid phase. Such pressure can be obtained by a method such as pressurizing the inside of the reactor with a gas that is inert to the polymerization reaction. By such a polymerization reaction, a conjugated diene-based polymer having an active terminal can be obtained.

For the conjugated diene-based polymer having an active terminal, the vinyl bond content in the structural unit derived from the conjugated diene compound is preferably 30 to 65 mol%, more preferably 33 to 62 mol%, and 35 to 35 to It is particularly preferably 60 mol%. If the vinyl bond content is less than 30 mol%, the grip characteristics tend to be too low, and if it exceeds 65 mol%, the wear resistance of the obtained crosslinked polymer tends to be deteriorated. In the present specification, the "vinyl bond content" is a value indicating the content ratio of the structural unit having a vinyl bond to all the structural units derived from the conjugated diene compound in the conjugated diene polymer, and is ¹ H-. It is a value measured by NMR.

<Degeneration process>
Next, the active terminal of the conjugated diene polymer obtained by the above polymerization reaction is reacted with the compounds (specific denaturants) represented by the following general formulas (1) to (4). Through these steps, a (A) conjugated diene-based polymer terminal-modified with a specific modifying agent can be obtained. The (A) conjugated diene polymer terminal-modified with such a specific modifying agent has a strong interaction with the filler at the terminal-modified site, so that the breaking strength and abrasion resistance are improved, and the strain is low. Since the rigidity is increased, the steering stability is also improved.

(In formula (1), A ¹ is a monovalent group bonded to L ¹ with an imino group, an amide group, a (thio) carbonyl group, a (thio) carbonyloxy group, a sulfide or a polysulfide, or is protected. Primary amino group, protected secondary amino group, tertiary amino group, nitrile group, pyridyl group, (thio) epoxy group, (thio) isocyanate group, (thio) formyl group, (thio) carboxylic acid ester, (Thio) Represents a metal salt of a carboxylic acid ester, a carboxylic acid halogen compound or an imidazolyl group, L ¹ represents a hydrocarbylene group having 1 to 20 carbon atoms, and R ¹ and R ² independently represent 1 to 4 carbon atoms. Represents the hydrocarbyl group of, n1 is 0 or 1.)

In the above formula (1), the hydrocarbylene group having 1 to 20 carbon atoms of L ¹ includes a linear or branched alkanediyl group having 1 to 20 carbon atoms and a cycloalkylene group having 3 to 20 carbon atoms. Examples thereof include an arylene group having 6 to 20 carbon atoms. In the above formula (1), as the hydrocarbyl group having 1 to 4 carbon atoms of R ¹ and R ^2, a linear or branched alkyl group having 1 to 4 carbon atoms and a cycloalkyl group having 3 to 4 carbon atoms are used. Can be mentioned. In the present specification, the (thio) carbonyl group represents a carbonyl group and a thiocarbonyl group, the (thio) carbonyloxy group represents a carbonyloxy group and a thiocarbonyloxy group, and the (thio) epoxy group represents an epoxy group and a thioepoxy group. The (thio) isocyanate group represents an isocyanate group and a thioisocyanate group, the (thio) formyl group represents a formyl group and a thioformyl group, and the (thio) carboxylic acid ester represents a carboxylic acid ester and a thiocarboxylic acid ester.

Specific examples of the compound represented by the above general formula (1) include N, N-dimethylaminopropyltriethoxysilane, N, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane, and N-benzylidene-3-tri. Examples thereof include ethoxysilyl-1-propaneamine, N- (3-trimethoxysilylpropyl) -4,5-dihydroimidazole, N- (3-triethoxysilylpropyl) -4,5-dihydroimidazole and the like.

(In formula (2), A ² is a monovalent group bonded to L ² with an imino group, an amide group, a (thio) carbonyl group, a (thio) carbonyloxy group, a sulfide or a polysulfide, or is protected. Primary amino group, protected secondary amino group, tertiary amino group, nitrile group, pyridyl group, (thio) epoxy group, (thio) isocyanate group, (thio) formyl group, (thio) carboxylic acid ester, (Thio) Represents a metal salt of a carboxylic acid ester, a carboxylic acid halogen compound, an imidazolyl group, or a group represented by the following formula (2a), and L ² and L ³ are independently single-bonded or hydro having 1 to 20 carbon atoms, respectively. It represents a carbylene group, R ³ and R ⁴ each independently represent a hydrocarbyl group having 1 to 4 carbon atoms, n2 is 0 to 3, and m1 is 0 or 1.)

(In formula (2a), L ³ , R ³ , R ⁴ and n 2 are the same as in formula (2), and * indicates a site that binds to L ^2. )

In the above formula (2), the hydrocarbylene group having 1 to 20 carbon atoms of L ² and L ³ is a linear or branched alkanediyl group having 1 to 20 carbon atoms and a cyclo having 3 to 20 carbon atoms. Examples thereof include an alkylene group and an arylene group having 6 to 20 carbon atoms. In the above formula (2), as the hydrocarbyl group having 1 to 4 carbon atoms of R ³ and R ^4, a linear or branched alkyl group having 1 to 4 carbon atoms and a cycloalkyl group having 3 to 4 carbon atoms are used. Can be mentioned.

Specific examples of the compound represented by the above general formula (2) include N, N-bis (trimethoxysilylpropyl) aminopropyl-3-imidazole and N, N-bis (triethoxysilylpropyl) aminopropyl-1. -Imidazole, N, N-bis (trimethoxysilyl) aminopropylmethyldiethylsilane, N, N, N-tris (triethoxysilylpropyl) amine, N, N, N', N'-tetrakis (3-triethoxy) Cyrilpropyl) -1,3-diaminopropane and the like can be mentioned.

(In the formula (3), A ³ are each independently, an imino group, an amido group, (thio) carbonyl group, a (thio) carbonyl group, secondary amino group, or a tertiary amino group, Z is a nitrogen atom Represents a t-valent group having 1 to 20 carbon atoms including or not containing, L ⁴ represents a single bond or a hydrocarbylene group having 1 to 20 carbon atoms, and L ⁵ represents a hydrocarbylene group having 1 to 20 carbon atoms. R ⁵ and R ⁶ each independently represent a hydrocarbyl group having 1 to 4 carbon atoms, n3 is 0 or 1, and t is 2 or 3).

In the above formula (3), Z is a divalent or trivalent group having 1 to 20 carbon atoms which may contain a nitrogen atom, but preferably contains a nitrogen atom. In the above formula (3), as a hydrocarbylene group of 1 to 20 carbon atoms hydrocarbylene group and L ⁵ of the L ⁴ having 1 to 20 carbon atoms, having 1 to 20 carbon atoms, straight or branched Examples thereof include an alkanediyl group, a cycloalkylene group having 3 to 20 carbon atoms, and an arylene group having 6 to 20 carbon atoms. In the above formula (3), as the hydrocarbyl group having 1 to 4 carbon atoms of R ⁵ and R ^6, a linear or branched alkyl group having 1 to 4 carbon atoms and a cycloalkyl group having 3 to 4 carbon atoms are used. Can be mentioned.

Specific examples of the compound represented by the general formula (3) include compounds represented by the following formulas (M-1) to (M-4).

In the above formula (M-1), R ¹¹ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and n5 represents an integer of 1 to 10.

(In the formula (4), R ⁷ and R ⁸ each independently represent a hydrocarbyl group having 1 to 20 carbon atoms, and R ⁹ is a hydrocarbyl group having 1 to 20 carbon atoms, a hydrogen atom contained in the alkyl group, and -CH. _At least one of 2-is a substituted alkyl group having 1 to 20 carbon atoms substituted with a group containing at least one element selected from the group consisting of silicon, nitrogen, phosphorus, oxygen and sulfur, or nitrogen. , An aromatic group having 6 to 20 carbon atoms containing at least one element selected from the group consisting of phosphorus, oxygen and sulfur, R ¹⁰ represents an alkanediyl group having 1 to 20 carbon atoms, and n4 represents an alkanediyl group having 1 to 20 carbon atoms. 1 or 2)

In the above formula (4), the hydrocarbyl groups having 1 to 20 carbon atoms of R ⁷ and R ⁸ include linear or branched alkyl groups having 1 to 20 carbon atoms and cycloalkyl groups having 3 to 20 carbon atoms. Examples thereof include an aryl group having 6 to 20 carbon atoms.

Specific examples of the compound represented by the above general formula (4) include N-phenyl-2,2-dimethoxy-1-aza-2-silacyclopentane, N- (3-triethoxysilylpropyl) -2, Examples thereof include 2-dimethoxy-1-aza-2-silacyclopentane.

In the modification reaction of the conjugated diene polymer having an active terminal, the specific modifier may be used alone, but the specific modifier and the modifier other than the specific modifier (hereinafter, "other modifiers"" Also called.) May be used. The other denaturing agent is not particularly limited as long as it is a compound having a functional group that interacts with the filler and capable of reacting with the active terminal of the polymer.

The above denaturation reaction can be carried out as, for example, a solution reaction. This solution reaction may be carried out using a solution containing an unreacted monomer after the completion of the polymerization reaction, and the conjugated diene polymer contained in the solution is isolated and dissolved in an appropriate solvent such as cyclohexane. You may go. Further, the modification reaction may be carried out by either a batch type or a continuous type. At this time, the method of adding the denaturant is not particularly limited, and examples thereof include a method of adding the denaturant all at once, a method of adding the denaturant in divided portions, and a method of continuously adding the denaturant.

The ratio of the specific modifier (the total amount when two or more kinds are used) is preferably 0.2 mol or more with respect to 1 mol of the metal atom involved in the polymerization reaction of the polymerization initiator. More preferably, it is 0.4 mol or more. When the amount is 0.2 mol or more, the modification reaction of the polymer terminal by the specific modifier can be sufficiently proceeded, and the interaction with the filler at the terminal modification site can be sufficiently strengthened. Further, in terms of reducing the amount of unreacted substances in the solution after the denaturation reaction, the upper limit of the usage ratio of the specific denaturant is 1.5 with respect to 1 mol of the metal atom involved in the polymerization reaction of the polymerization initiator. The amount is preferably less than 1.2 mol, more preferably less than 1.2 mol.

When the specific denaturant and other denaturants are used in combination in the denaturation reaction, the ratio of the other denaturants used is specified from the viewpoint of sufficiently advancing the reaction between the conjugated diene polymer and the specific denaturant. It is preferably 30 mol% or less, more preferably 20 mol% or less, and particularly preferably 10 mol% or less, based on the total usage ratio of the denaturant and other denaturants.

The temperature of the modification reaction is usually the same as the temperature of the polymerization reaction, preferably −20 ° C. to 150 ° C., more preferably 0 ° C. to 120 ° C., and preferably 20 ° C. to 100 ° C. Especially preferable. When the temperature of the modification reaction is low, the viscosity of the conjugated diene polymer after modification tends to increase. On the other hand, when the temperature of the modification reaction is high, the active end of the polymer is likely to be deactivated. The reaction time of the degeneration reaction is preferably 1 minute to 5 hours, more preferably 2 minutes to 1 hour.

The (A) conjugated diene polymer contained in the reaction solution can be isolated by a known desolvation method such as steam stripping and a drying operation such as heat treatment. The Mooney viscosity of the obtained (A) conjugated diene polymer may be adjusted by adding a stretching oil or the like, if necessary. By this treatment, workability can be improved. Examples of the spreading oil include aroma oil, naphthenic oil, paraffin oil and the like. The blending amount of the spreading oil may be appropriately set according to the monomer used for the polymerization and the like, and is, for example, 10 to 50 parts by mass with respect to 100 parts by mass of the conjugated diene polymer.

In this way, the (A) conjugated diene-based polymer can be obtained. According to the conjugated diene-based polymer (A), the compatibility with the filler can be improved, and a polymer composition having improved processability can be obtained. By using a polymer composition containing such a conjugated diene-based polymer (A), heat generation, breaking strength, abrasion resistance, fuel efficiency, wet grip, etc. required for applications such as automobile tires can be obtained. It is possible to obtain a tire (crosslinked polymer) which is excellent but has low rolling resistance.

The conjugated diene polymer (A) preferably has a structure derived from any of the compounds of the above general formulas (1) to (4) at at least one end of the polymer. When the conjugated diene polymer (A) has such a structure, the dispersibility of a filler such as carbon black or silica is further improved when applied to, for example, tire applications, and in terms of low loss resistance and wear resistance. , It is preferable in that it produces a higher improvement effect.

(A) The polystyrene-equivalent weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) of the conjugated diene polymer is preferably 100,000 to 2,000,000. When Mw is smaller than 100,000, the crosslinked polymer of the polymer composition according to the present embodiment tends to have low loss resistance and wear resistance, and when it is larger than 2,000,000, it tends to be deteriorated. The processability of the polymer composition tends to decrease. The weight average molecular weight (Mw) of the obtained conjugated diene polymer (A) is more preferably 150,000 to 1,500,000, still more preferably 200,000 to 1,000,000.

(A) The molecular weight distribution of the conjugated diene polymer, that is, the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is preferably 1.5 to 3.0, more preferably. Is 1.5 to 2.5, and particularly preferably 1.5 to 2.2. When the molecular weight distribution of the conjugated diene polymer (A) is within the above range, more excellent low loss property, wear resistance, wet grip performance and mechanical properties can be easily obtained.

1.2. (B) Carbon Black The polymer composition according to the present embodiment has (B) a carbon black having a nitrogen adsorption specific surface area (N ₂ SA) of 75 m ² / g or more and 130 m ² / g or less (in the present specification, simply " (B) Also referred to as "carbon black"). The polymer composition according to the present embodiment contains (B) carbon black having a specific nitrogen adsorption specific surface area, so that the (A) conjugated diene-based copolymer and (B) carbon black are compatible with each other. Therefore, it is possible to obtain a polymer composition having improved processability. Further, according to the polymer composition according to the present embodiment, the inclusion of (B) carbon black provides an excellent reinforcing effect, and is highly balanced in breaking strength, wear resistance and fuel efficiency. A crosslinked polymer (tire) can be produced.

(B) The nitrogen adsorption specific surface area (N ₂ SA) of carbon black is 75 m ² / g or more, preferably 78 m ² / g or more, more preferably 82 m ² / g or more, and particularly preferably 85 m. ^{It is 2} / g or more. If N ₂ SA is less than 75 m ² / g, a sufficient reinforcing effect cannot be obtained, and a crosslinked polymer having excellent breaking strength and wear resistance may not be obtained. The N ₂ SA is 130 m ² / g or less, preferably 125 m ² / g or less, more preferably 123 m ² / g or less, and particularly preferably 120 m ² / g or less. When N ₂ SA exceeds 130 m ² / g, fuel efficiency tends to deteriorate. In addition, (B) carbon black N ₂ SA can be measured according to the method described in JIS K6217-2: 2001.

The content ratio of (B) carbon black is 30 parts by mass or more, preferably 35 parts by mass or more, and more preferably 40 parts by mass with respect to 100 parts by mass of the polymer component contained in the polymer composition. That is all. (B) When the content ratio of carbon black is less than 30 parts by mass, the breaking strength and wear resistance of the obtained crosslinked polymer (tire) tend to be inferior. The content ratio of (B) carbon black is 80 parts by mass or less, preferably 75 parts by mass or less, with respect to 100 parts by mass of the polymer component contained in the polymer composition. (B) When the content ratio of carbon black exceeds 80 parts by mass, the fuel efficiency of the obtained crosslinked polymer (tire) tends to deteriorate. When the content ratio of (B) carbon black is within the above range, a crosslinked polymer (tire) having a highly balanced balance in breaking strength, wear resistance and fuel efficiency can be produced.

1.3. Other Ingredients In addition to the above-mentioned components, the polymer composition according to the present embodiment may contain other diene-based polymers other than (A) conjugated diene-based polymer and (B) carbon black, if necessary. Fillers, silane coupling agents, cross-linking agents, acidic compounds, spreading oils (process oils), antioxidants, vulcanization accelerators, as well as vulcanization aids, processing aids, scorch inhibitors and zinc oxide as needed. , Softeners, colorants, flame retardants, lubricants, foaming agents, plasticizers, antioxidants, UV inhibitors, antistatic agents, color inhibitors, etc., depending on the purpose of use of the polymer composition. Can be used.

<Other polymers>
The polymer composition according to the present embodiment may contain other diene-based polymers other than the (A) conjugated diene-based polymer. Such a diene-based polymer is not particularly limited as long as it has a repeating unit derived from a conjugated diene compound, and for example, natural rubber, polybutadiene, polyisoprene, ethylene-propylene-diene rubber, styrene-butadiene rubber, acrylonitrile-. Examples include butadiene rubber.

When the polymer composition according to the present embodiment contains other polymers, the content ratio of the other polymers is when the total amount of the polymer components contained in the polymer composition is 100 parts by mass. It is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and particularly preferably 35 parts by mass or less.

<Filler>
The polymer composition according to the present embodiment may contain a filler other than (B) carbon black in order to further improve the low loss property, abrasion resistance and wet grip property of the obtained crosslinked polymer. Examples of such a filler include mica such as silica, calcium carbonate and sericite, aluminum hydroxide, magnesium oxide, magnesium hydroxide, clay, talc, alumina, titanium oxide and mica. These fillers may be used alone or in combination of two or more. Among these fillers, silica is particularly preferable.

(silica)
Examples of silica include wet silica (hydrous silicic acid), dry silica (silicic anhydride), calcium silicate, and aluminum silicate. Among these, wet silica is preferable because it has a large number of silanol groups.

The nitrogen adsorption specific surface area (N ₂ SA) of silica is preferably 40 m ² / g or more, more preferably 50 m ² / g or more, still more preferably 100 m ² / g or more, and particularly preferably 150 m. ^{It is 2} / g or more. The N ₂ SA of silica is preferably 300 m ² / g or less, more preferably 250 m ² / g or less, and particularly preferably 20 m ² / g or less. When the N ₂ SA of silica is within the above range, the dispersibility of silica in the polymer composition is improved, so that the workability is improved, and the breaking strength, fuel efficiency and steering stability are highly balanced. In some cases, an excellent crosslinked polymer (tire) can be produced. The N ₂ SA of silica is a value measured by the BET method according to the method described in ASTM D3037-81.

When the polymer composition according to the present embodiment contains silica, the content ratio of silica is preferably 10 parts by mass or more with respect to 100 parts by mass of the polymer component contained in the polymer composition. It is preferably 20 parts by mass or more, and particularly preferably 25 parts by mass or more. The silica content is preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 70 parts by mass with respect to 100 parts by mass of the polymer component contained in the polymer composition. It is not more than parts by mass, and particularly preferably 60 parts by mass or less. When the content ratio of silica is within the above range, the dispersibility of silica in the polymer composition is improved, so that the processability is improved, and the breaking strength, fuel efficiency and steering stability are highly balanced. In some cases, a crosslinked polymer (tire) can be produced.

<Silane coupling agent>
Examples of the silane coupling agent include bis (3-triethoxysilylpropyl) tetrasulfide, bis (3-triethoxysilylpropyl) trisulfide, bis (3-triethoxysilylpropyl) disulfide, and bis (2-triethoxy). Cyrilethyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyl Trimethoxysilane, 2-mercaptoethyltriethoxysilane; 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, 3-triethoxysilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, 2-triethoxy Cyrilethyl-N, N-dimethylthiocarbamoyltetrasulfide, 3-trimethoxysilylpropylbenzothiazolyltetrasulfide, 3-triethoxysilylpropylbenzolyltetrasulfide, 3-triethoxysilylpropylmethacrylate monosulfide, 3-tri Methoxysilylpropyl methacrylate monosulfide, bis (3-diethoxymethylsilylpropyl) tetrasulfide, 3-mercaptopropyl dimethoxymethylsilane, dimethoxymethylsilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, dimethoxymethylsilylpropylbenzothiazoli Examples thereof include rutetrasulfide and 3-octanoylthio-1-propyltriethoxysilane. These compounds can be used alone or in combination of two or more. Among these, bis (3-triethoxysilylpropyl) trisulfide, bis (3-triethoxysilylpropyl) disulfide, and 3-trimethoxysilylpropylbenzothiazolyltetra from the viewpoint of improving the reinforcing property. Sulfide is preferred.

The ratio of the silane coupling agent used is preferably 0.5 to 20 parts by mass with respect to 100 parts by mass of the filler component. When the ratio of the silane coupling agent used is within the above range, sufficient reinforcing properties and fracture resistance can be imparted to the crosslinked polymer formed from the polymer composition, and the abrasion resistance of the crosslinked polymer is improved. You may be able to do it.

<Crosslinking agent>
Examples of the cross-linking agent include sulfur, sulfur halides, organic peroxides, quinonedioximes, organic polyvalent amine compounds, alkylphenol resins having a methylol group, and the like. Of these, sulfur is usually used as the cross-linking agent. The ratio of the cross-linking agent used is preferably 0.1 to 10 parts by mass, and more preferably 0.5 to 5 parts by mass with respect to 100 parts by mass of the polymer component.

<Acid compound>
As the acidic compound, saturated fatty acids having 12 to 24 carbon atoms and metal salts thereof are preferably used. Specific examples of acidic compounds include lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, nonadecylic acid, arachidic acid, henicosylic acid, bechenic acid, tricosylic acid, lignoceric acid, and these. Examples of saturated fatty acids include calcium salt and zinc salt. These acidic compounds can be used alone or in combination of two or more. Of these, stearic acid is preferred. The ratio of the acidic compound used is preferably 0.3 to 15 parts by mass with respect to 100 parts by mass of the polymer component.

<Other additives>
Examples of the spreading oil include aroma oil, naphthenic oil, paraffin oil and the like. The proportion of the spreading oil used is 0 to 50 parts by mass with respect to 100 parts by mass of the polymer component.

Examples of the antiaging agent include N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine and the like. The ratio of the anti-aging agent used is 0.5 to 5 parts by mass with respect to 100 parts by mass of the polymer component.

Examples of the vulcanization aid include zinc oxide and the like. The ratio of the vulcanization aid used is 1 to 5 parts by mass with respect to 100 parts by mass of the polymer component.

Examples of the vulcanization accelerator include guadinin-based, aldehyde-amine-based, aldehyde-ammonia-based, thiazole-based, sulfenamide-based, thiourea-based, thiuram-based, dithiocarbamate-based, and zantate-based compounds. Preferred specific examples of the vulcanization accelerator are sulfenamides such as N-cyclohexyl-2-benzothiazyl sulfenamide (CBS) and N-tetra-butyl-2-benzothiazyl sulfenamide (TBBS). Examples include vulcanization accelerators. The proportion of the vulcanization accelerator used is appropriately determined in consideration of the type and proportion of the basic compound, but is preferably 0.5 to 5 parts by mass with respect to 100 parts by mass of the polymer component.

1.4. Method for Producing Polymer Composition The polymer composition according to the present embodiment can be prepared by kneading each of the above components using, for example, a kneader such as a plastomill, a Banbury mixer, a roll, or an internal mixer. it can. For example, it is preferable to prepare by the following method.

<First stage kneading>
In the first-stage kneading, it is preferable to knead the (A) conjugated diene polymer and (B) carbon black together with other fillers and silane coupling agents added as needed. Further, in the first-stage kneading, other polymers, a spreading oil, an antiaging agent and the like are also kneaded together, if necessary. Further, in the first-stage kneading, the acidic compounds, which are preferably kneaded in the second-stage kneading, may be kneaded together.

By applying the filler to the first-stage kneading, the dispersibility of these is likely to be improved, and the fuel efficiency performance of the tire (crosslinked polymer) formed from the obtained polymer composition may be improved.

When a silane coupling agent is used for the first-stage kneading, first, (A) conjugated diene polymer, (B) carbon black, other polymer, and if necessary, other fillers are kneaded. After that, it is preferable to add (post-add) a silane coupling agent and further knead.

By post-adding the silane coupling agent in the first-stage kneading, the obtained polymer composition becomes more processable, and the crosslinked polymer formed from the polymer composition has more excellent low hysteresis. It will have characteristics. Further, when the polymer composition contains silica as a filler, the dispersibility of silica can be improved.

When the silane coupling agent is added afterwards, the timing of adding the silane coupling agent depends on the type of silica, the ratio of silica used, the kneading conditions, etc., and the use of (A) conjugated diene polymer and other polymers. It is determined as appropriate in consideration of the ratio.

When a silane coupling agent is added afterwards, (A) conjugated diene polymer (B) carbon black and other polymers are blended and kneaded for 0.5 to 10 minutes, and then the silane cup is used. It is preferable to add a ring agent and knead for 0.5 to 10 minutes.

Examples of the kneading machine used for the first-stage kneading include an open type or a closed type kneader such as a plast mill, a Banbury mixer, a roll, and an internal mixer. Further, in the first-stage kneading, the kneading temperature is set to 30 ° C. to 180 ° C., preferably 50 ° C. to 160 ° C.

Further, when the silane coupling agent is used for the first-stage kneading, the method is not limited to the method of adding the silane coupling agent afterwards and kneading, and the silane coupling agent is used for the first-stage kneading. A kneaded product containing a silane coupling agent may be obtained by a method of kneading all the components at once. Alternatively, a method of adding other polymers and additives after preparing a masterbatch in which (A) conjugated diene polymer, (B) carbon black, silica as a filler and a silane coupling agent are kneaded may be used. ..

<Second stage kneading>
The second-stage kneading is a step of adding at least a cross-linking agent to the kneaded product obtained in the first-stage kneading and kneading the kneaded product and the cross-linking agent to obtain a polymer composition. In this second-stage kneading, it is preferable that the acidic compound is kneaded together with the kneaded product obtained in the first-stage kneading and the cross-linking agent. Further, in the second stage kneading, zinc oxide and the vulcanization accelerator are also kneaded together, if necessary. Then, in the second-stage kneading, all the components normally used for the second-stage kneading (specifically, the kneaded product obtained in the first-stage kneading, the cross-linking agent, and if necessary) A polymer composition can be obtained by a method of simultaneously kneading an acidic compound and other components such as zinc oxide and a vulcanization accelerator.

By applying the acidic compound to the second-stage kneading, the obtained polymer composition has more excellent processability, and the crosslinked polymer formed from the polymer composition has more excellent low loss property. Will have.

In the second stage kneading, the kneading machine used in the first stage kneading is used. Further, in the second stage kneading, the kneading temperature is set to 30 ° C. to 130 ° C., preferably 50 ° C. to 110 ° C.

The polymer composition obtained by the above-mentioned production method is an unvulcanized rubber composition, and a crosslinked polymer is formed by performing a crosslinking treatment such as vulcanization, for example.

1.5. Applications The crosslinked polymer formed from the polymer composition according to this embodiment is suitably used as a tire, specifically, a tread of a tire. The tire formed from the polymer composition according to the present embodiment has high strength in the tread and a desired shape in the tread, so that excellent performance can be obtained. Further, the crosslinked polymer formed from the polymer composition according to the present embodiment can also be used as a tire member other than a tread, a vibration-proof rubber, a fender, a belt, a hose, and other industrial products.

2. 2. Examples Hereinafter, specific examples of the present invention will be described, but the present invention is not limited to these examples. In addition, "%" in the following production examples, examples and comparative examples is based on mass unless otherwise specified.

2.1. (A) Production Example of Conjugated Diene Polymer <Production Example 1>
An autoclave reactor having an internal volume of 5 liters substituted with nitrogen was charged with 2500 g of cyclohexane, 50 g of tetrahydrofuran as a vinyl group content modifier (randomizer), and 125 g of styrene and 365 g of 1,3-butadiene as monomers. After adjusting the temperature of the contents of the reactor to 10 ° C., 5.20 mmol of n-butyllithium was added as a polymerization initiator to initiate polymerization. The polymerization was carried out under adiabatic conditions and the maximum temperature reached 85 ° C.
When the polymerization conversion rate reaches 99% (25 minutes after the start of polymerization), 10 g of 1,3-butadiene is added over 1 minute, and then N- (3-trimethoxysilylpropyl) as a denaturing agent is added. The reaction was carried out for 15 minutes by adding 1.53 mmol of -4,5-dihydroimidazole. Immediately before the addition of the modifier, sampling was performed to measure the weight average molecular weight of the polymer before modification.
To the polymer solution containing the obtained modified conjugated diene-based copolymer, 4.40 g of 2,6-di-tert-butyl-p-cresol was added. Then, the solvent was removed by steam stripping, and the mixture was dried by a heat roll adjusted to 110 ° C. to obtain a modified conjugated diene-based copolymer (hereinafter, also referred to as “SBR-1”).

<Manufacturing example 2>
In Production Example 1, 1.15 mmol of N, N-bis (3-trimethoxysilylpropyl) -3-imidazolylpropylamine was added in place of N- (3-trimethoxysilylpropyl) -4,5-dihydroimidazole. The same operation was carried out except for the above, to obtain a modified conjugated diene-based copolymer (hereinafter, also referred to as “SBR-2”).

<Manufacturing example 3>
In Production Example 1, 1,16-bis (triethoxysilyl) -4,12-diyl-4,13-diazahexadecane was used instead of N- (3-trimethoxysilylpropyl) -4,5-dihydroimidazole. The same operation was carried out except that 0.767 mmol was added to obtain a modified conjugated diene-based copolymer (hereinafter, also referred to as “SBR-3”).

<Manufacturing example 4>
In Production Example 1, 1-triethoxysilyl-4,9,11-trimethyl-4,8-diaza-8-tridecene was used instead of N- (3-trimethoxysilylpropyl) -4,5-dihydroimidazole. The same operation was carried out except that 2.30 mmol was added to obtain a modified conjugated diene-based copolymer (hereinafter, also referred to as “SBR-4”).

<Manufacturing example 5>
In Production Example 1, the same operation was carried out except that 1.15 mmol of silicon tetrachloride was added instead of N- (3-trimethoxysilylpropyl) -4,5-dihydroimidazole, and the conjugated diene copolymer (conjugated diene-based copolymer ( Hereinafter, it is also referred to as “SBR-5”).

2.2. Measurement method of physical properties <Measurement of number average molecular weight (Mn) and weight average molecular weight (Mw)>
For each polymer produced above, gel permeation chromatography (GPC) (“HLC-8120” manufactured by Tosoh Corporation) is used to correspond to the peak of the maximum peak of the GPC curve obtained under the following GPC conditions. From the holding time, the polystyrene-equivalent number average molecular weight (Mn) and weight average molecular weight (Mw) were calculated.
(GPC condition)
Column: 2 product name "GMHXL" (manufactured by Tosoh Corporation) Column temperature: 40 ° C
Mobile phase: tetrahydrofuran Flow rate: 1.0 ml / min Sample concentration: 10 mg / 20 ml

<Measurement of vinyl content and bound styrene content>
-Vinyl content (%): Measured by ¹ H-NMR measurement at 400 MHz.
-Binding styrene content (%): Measured by ¹ H-NMR measurement at 400 MHz. The bound styrene content is a parameter corresponding to the aromatic vinyl content.

<Measurement of carbon black nitrogen adsorption specific surface area (N ₂ SA)>
The nitrogen adsorption specific surface area (N ₂ SA) was determined for each carbon black shown in Table 2 or Table 3 below in accordance with JIS K6217-2: 2001.

2.3. Examples 1 to 13 and Comparative Examples 1 to 10
2.3.1. Production of Polymer Composition and Crosslinked Polymer A polymer composition was produced by blending each component according to the formulation shown in Table 2 or Table 3 below and kneading them. Kneading was carried out by the following method.

Using a plast mill (content capacity 250 cc) with a temperature control device, as the first stage kneading, under the conditions of a filling rate of 72% and a rotation speed of 60 rpm, the polymer components shown in Table 2 or Table 3 below, carbon black, A silane coupling agent, stearic acid, an antiaging agent, and zinc oxide were kneaded. Next, as the second-stage kneading, the kneaded product obtained above is cooled to room temperature, and then sulfur and a vulcanization accelerator are kneaded to form the polymers of Examples 1 to 13 and Comparative Examples 1 to 10. I got something.

Next, each of the obtained polymer compositions was molded and vulcanized at 160 ° C. for a predetermined time with a vulcanization press to obtain each crosslinked polymer having a predetermined shape to be subjected to the following evaluation test.

2.3.2. Evaluation of Crosslinked Polymers The following evaluation tests were conducted on each of the obtained crosslinked polymers. The results are shown in Table 2 or Table 3 below.

<Breaking strength>
In accordance with JIS K6251: 2010, a No. 3 dumbbell type test piece made of the crosslinked polymer obtained above was prepared and used as a test piece for evaluation. Using a tensile tester (model name "AG-2000", manufactured by Shimadzu Corporation), the test piece was pulled at a load speed of 500 mm / min to determine the breaking strength (TB). In Table 2 and Table 3 below, it is shown by an index when the measured value of Comparative Example 1 is set to 100 as a reference, and the larger the value, the higher the intensity.

<Abrasion resistance>
The crosslinked polymer obtained above was used as a measurement sample, and was measured at 25 ° C. with a load of 10 N using a DIN wear tester (manufactured by Toyo Seiki Co., Ltd.) in accordance with JIS K6264-2: 2005. In Table 2 and Table 3 below, it is shown by an index when the measured value of Comparative Example 1 is set to 100 as a reference, and the larger the value, the better the wear resistance.

2.4. Evaluation Results Table 1 below shows the physical property values of each polymer synthesized above. Tables 2 and 3 below show the composition and evaluation results of each polymer composition.

In Tables 2 and 3, the numerical values of each component in the composition of the polymer composition represent parts by mass. The following products were used as the materials shown in Tables 2 and 3 above.
-NR: "TSR20", natural rubber-CB-1: manufactured by Cabot, product name "Show Black N220", nitrogen adsorption specific surface area: 114 m ² / g, carbon black-CB-2: manufactured by Mitsubishi Chemical, product name "Diablack N339", nitrogen adsorption specific surface area: 88 m ² / g, carbon black CB-3: manufactured by Tokai Carbon Co., Ltd., trade name "Seast 9", nitrogen adsorption specific surface area: 142 m ² / g, carbon black stearic acid : Made by Nichiyu Co., Ltd., Product name "Beads Steeric Acid Tsubaki"
-Anti-aging agent: Ouchi Shinko Kagaku Kogyo Co., Ltd., trade name "Nocrack 810NA", N-phenyl-N'-isopropyl-p-phenylenediamine-Zinc oxide: Mitsui Mining & Smelting Co., Ltd., trade name "Zinc Hua No. 1""
-Vulcanization accelerator CZ: manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd., trade name "Noxera CZ", N-cyclohexyl-2-benzothiazolysulfurphenamide Name "Noxera D", 1,3-diphenylguanidine / sulfur: manufactured by Tsurumi Chemical Industry Co., Ltd.

From the results of Tables 2 and 3, the polymer compositions according to Examples 1 to 13 have better processability than the polymer compositions according to Comparative Example 1 because the dispersibility of the filler is improved. It was confirmed that a crosslinked polymer having a high balance in breaking strength and wear resistance could be obtained.

The present invention is not limited to the above embodiment, and various modifications are possible. The present invention includes substantially the same configurations as those described in the embodiments (eg, configurations with the same function, method and result, or configurations with the same purpose and effect). The present invention also includes a configuration in which a non-essential part of the configuration described in the above embodiment is replaced with another configuration. Further, the present invention also includes a configuration that exhibits the same effects as the configuration described in the above embodiment or a configuration that can achieve the same object. Further, the present invention also includes a configuration in which a known technique is added to the configuration described in the above embodiment.

Claims (5)

1. (A) A polymer of a conjugated diene compound or a copolymer of a conjugated diene compound and an aromatic vinyl compound, which comprises an active polymerization terminal and a compound represented by any of the following general formulas (1) to (4). Conjugated diene-based polymer, which is a reactant,
   (B) Carbon black having a nitrogen adsorption specific surface area (N ₂ SA) of 75 m ² / g or more and 130 m ² / g or less.
   Contains,
   A polymer composition containing 30 parts by mass or more and 80 parts by mass or less of the carbon black (B) with respect to 100 parts by mass of the polymer component contained in the polymer composition.
   

   

   
   (In formula (1), A ¹ is a monovalent group bonded to L ¹ with an imino group, an amide group, a (thio) carbonyl group, a (thio) carbonyloxy group, a sulfide or a polysulfide, or is protected. Primary amino group, protected secondary amino group, tertiary amino group, nitrile group, pyridyl group, (thio) epoxy group, (thio) isocyanate group, (thio) formyl group, (thio) carboxylic acid ester, (Thio) Represents a metal salt of a carboxylic acid ester, a carboxylic acid halogen compound or an imidazolyl group, L ¹ represents a hydrocarbylene group having 1 to 20 carbon atoms, and R ¹ and R ² independently represent 1 to 4 carbon atoms. Represents the hydrocarbyl group of, n1 is 0 or 1.)
   

   

   
   (In formula (2), A ² is a monovalent group bonded to L ² with an imino group, an amide group, a (thio) carbonyl group, a (thio) carbonyloxy group, a sulfide or a polysulfide, or is protected. Primary amino group, protected secondary amino group, tertiary amino group, nitrile group, pyridyl group, (thio) epoxy group, (thio) isocyanate group, (thio) formyl group, (thio) carboxylic acid ester, (Thio) Represents a metal salt of a carboxylic acid ester, a carboxylic acid halogen compound, an imidazolyl group, or a group represented by the following formula (2a), and L ² and L ³ are independently single-bonded or hydro having 1 to 20 carbon atoms, respectively. It represents a carbylene group, R ³ and R ⁴ each independently represent a hydrocarbyl group having 1 to 4 carbon atoms, n2 is 0 to 3, and m1 is 0 or 1.)
   

   

   
   (In formula (2a), L ³ , R ³ , R ⁴ and n 2 are the same as in formula (2), and * indicates a site that binds to L ^2. )
   

   

   
   (In the formula (3), A ³ are each independently, an imino group, an amido group, (thio) carbonyl group, a (thio) carbonyl group, secondary amino group, or a tertiary amino group, Z is a nitrogen atom Represents a t-valent group having 1 to 20 carbon atoms including or not containing, L ⁴ represents a single bond or a hydrocarbylene group having 1 to 20 carbon atoms, and L ⁵ represents a hydrocarbylene group having 1 to 20 carbon atoms. R ⁵ and R ⁶ each independently represent a hydrocarbyl group having 1 to 4 carbon atoms, n3 is 0 or 1, and t is 2 or 3).
   

   

   
   (In the formula (4), R ⁷ and R ⁸ each independently represent a hydrocarbyl group having 1 to 20 carbon atoms, and R ⁹ is a hydrocarbyl group having 1 to 20 carbon atoms, a hydrogen atom contained in the alkyl group, and -CH. _At least one of 2-is a substituted alkyl group having 1 to 20 carbon atoms substituted with a group containing at least one element selected from the group consisting of silicon, nitrogen, phosphorus, oxygen and sulfur, or nitrogen. , An aromatic group having 6 to 20 carbon atoms containing at least one element selected from the group consisting of phosphorus, oxygen and sulfur, R ¹⁰ represents an alkanediyl group having 1 to 20 carbon atoms, and n4 represents an alkanediyl group having 1 to 20 carbon atoms. 1 or 2)
2. The polymer composition according to claim 1, wherein the polystyrene-equivalent weight average molecular weight of the conjugated diene polymer (A) measured by gel permeation chromatography is 100,000 to 2,000,000.
3. The polymer composition according to claim 1 or 2, further comprising a cross-linking agent.
4. A crosslinked polymer produced by using the polymer composition according to claim 3.
5. A tire using the crosslinked polymer according to claim 4.