JPWO2008044722A1 - Oil-extended rubber composition, method for producing the same, tire member and tire - Google Patents

Abstract

The present invention provides a rubber composition excellent in wear resistance and low heat build-up, a method for producing the same, a tire member using the rubber composition, and a tire. A conjugated diene polymer having at least a butadiene unit, having a Mooney viscosity of 65 to 200 (ML1 + 4, 100 ° C.) and a molecular weight distribution of 1.5 to 4.0, and having 96 in the butadiene unit portion. 100 parts by weight of a rubber component and a process oil of 10 to 120 containing a conjugated diene polymer (P1) having a cis-1,4-bond content of 5% or more and a vinyl bond content of 1.0% or less as an essential component An oil-extended rubber composition comprising parts by weight. [Selection figure] None

Description

  The present invention relates to an oil-extended rubber composition, a production method thereof, a tire member obtained from the same, and a tire. More specifically, an oil-extended rubber composition comprising a rubber component whose essential component is a specific conjugated diene polymer having a specific monomer composition, a specific microstructure and a specific molecular weight characteristic, a method for producing the same, The present invention relates to a tire member comprising the oil-extended rubber composition and a tire provided with the tire member.

  In general, rubber for tires needs to have an excellent balance of impact resilience, abrasion resistance and low heat build-up, and therefore, polybutadiene having a cis-1,4-bond content as high as possible and a narrow molecular weight distribution is required. It has been. The use of a polymerization catalyst containing a lanthanum series metal such as neodymium is known to be advantageous for the production of such polybutadiene (hereinafter sometimes referred to as “BR”). Has been done.

For example, Patent Document 1 discloses a rubber composition containing a rubber having a glass transition temperature of −50 ° C. or less and a paraffin oil having a weight average molecular weight of 500 or more. Patent Document 2 discloses a rubber composition in which parabutadiene oil is mixed with polybutadiene having a cis-1,4-bond content of 96% and a weight average molecular weight of 400,000. However, these rubber compositions have a problem in wear resistance although they are excellent in low temperature characteristics.
Patent Documents 3 and 4 disclose rubber compositions containing polybutadiene having a high cis-1,4-bond content and oil having an aromatic content of 10% or less. However, this rubber composition has a problem that it is inferior in wear and low heat build-up.

Japanese Patent Laid-Open No. 04-81438 JP 2004-277506 A JP 2005-36065 A JP 2005-154754 A

Accordingly, an object of the present invention is to provide an oil-extended rubber composition excellent in wear resistance and low heat build-up and a method for producing the same.
Another object of the present invention is to provide a tire member using this oil-extended rubber composition.
Still another object of the present invention is to provide a tire comprising the tire member.

  As a result of intensive studies to achieve the above object, the present inventors are composed of a lanthanum series metal compound (A), an organoaluminum compound (B), an organoaluminum hydride compound (C), and a halogen compound (D). A conjugated diene polymer having a higher cis-1,4-bond content and a narrower molecular weight distribution by using a polymerization catalyst containing an organoaluminum compound and an organoaluminum hydride compound in a specific ratio in the polymerization catalyst As a result of further research based on this knowledge, an oil-extended rubber composition having excellent wear resistance and low heat build-up by blending a specific amount of a specific process oil with the conjugated diene polymer. The present inventors have found that a product can be obtained, and have completed the present invention.

Thus, according to the present invention, a conjugated diene polymer having at least a butadiene unit, having a Mooney viscosity of 65 to 200 (ML _{1 + 4} , 100 ° C.) and a molecular weight distribution of 1.5 to 4.0, and 100 parts by weight of a rubber component having as essential components a conjugated diene polymer (P1) having a cis-1,4-bond content of 96.5% or more and a vinyl bond content of 1.0% or less in the butadiene unit portion; An oil-extended rubber composition comprising 10 to 120 parts by weight of a process oil containing 5% by weight or more of an aroma is provided.
In the oil-extended rubber composition of the present invention, the conjugated diene polymer (P1) has a Mooney viscosity (ML _{1 + 4} , 100 ° C.) of 75 to 175, a molecular weight distribution of 2.0 to 3.5, and a butadiene unit. It is preferable that the cis-1,4-bond content in the portion is 97.5% or more and the vinyl bond content is 0.9% or less.
In the oil-extended rubber composition of the present invention, the ratio of butadiene units in the conjugated diene polymer (P1) is preferably 80% by weight or more.

（式中、Ｍは、Ｓｉ、Ｇｅ、Ｓｎ又はＴｉであり、Ｘはハロゲン原子である。Ｘが複数存在するときは、それらは、互いに同じでも異なっていてもよい。Ｒ^１は、単結合であるか、ヘテロ原子を含んでいてもよい炭素数１〜２０の炭化水素基を表す。Ｒ^２は、水素、又はヘテロ原子を含んでいてもよい炭素数１〜２０の炭化水素基を表す。Ｒ^２が複数存在するときは、それらは、互いに同じでも異なっていてもよい。ｇ及びｈは、それぞれ、１〜４の整数を表す。ｈが１のとき、ｆは０である。ｈが２〜４のとき、ｆは１であり、少なくとも１つのＲ^２はＲ^１と結合しているが、このときＲ^２は単結合であってもよい）。
更に、本発明の油展ゴム組成物において、重合触媒が、ランタン系列金属化合物（Ａ）、有機アルキルアルミニウム化合物（Ｂ）、有機アルミニウムハイドライド化合物（Ｃ）及びハロゲン化合物（Ｄ）で構成されるものであって、有機アルキルアルミニウム化合物（Ｂ）と有機アルミニウムハイドライド化合物（Ｃ）とのモル比（Ｂ／Ｃ）が、５≦（Ｂ／Ｃ）≦１，０００を満たすものであることが好ましい。In the oil-extended rubber composition of the present invention, the conjugated diene polymer (P1) is composed of a lanthanum series metal compound (A), an organoaluminum compound (B), an organoaluminum hydride compound (C), and a halogen compound (D). It is preferably obtained by polymerizing a monomer containing butadiene as an essential component using a polymerization catalyst.
In the oil-extended rubber composition of the present invention, the conjugated diene polymer (P1) is composed of a lanthanum series metal compound (A), an organoaluminum compound (B), an organoaluminum hydride compound (C), and a halogen compound (D). It is preferable that the conjugated diene monomer be polymerized using the polymerization catalyst thus obtained, and further modified with an organometallic halide (E) represented by the following general formula (1).

(In the formula, M is Si, Ge, Sn or Ti, and X is a halogen atom. When a plurality of X are present, they may be the same as or different from each other. R ¹ is a single bond. Or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom, and R ² represents hydrogen or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. When a plurality of R ² are present, they may be the same as or different from each other, g and h each represent an integer of 1 to 4. When h is 1, f is 0. h Is 2 to 4, f is 1, and at least one R ² is bonded to R ¹ , but at this time R ² may be a single bond).
Furthermore, in the oil-extended rubber composition of the present invention, the polymerization catalyst is composed of a lanthanum series metal compound (A), an organic alkylaluminum compound (B), an organic aluminum hydride compound (C), and a halogen compound (D). And it is preferable that the molar ratio (B / C) of the organoalkylaluminum compound (B) and the organoaluminum hydride compound (C) satisfies 5 ≦ (B / C) ≦ 1,000.

In the oil-extended rubber composition of the present invention, it is preferable that the process oil contains 10 to 40% by weight of aroma.
In the oil-extended rubber composition of the present invention, it is preferable that the rubber component is composed only of the conjugated diene polymer (P1).
In the oil-extended rubber composition of the present invention, the rubber component is 5% by weight or more of the conjugated diene polymer (P1), and the polymer rubber (P2) other than the conjugated diene polymer (P1) is 95% by weight or less, It is preferable that it consists of.
Furthermore, in the oil-extended rubber composition of the present invention, the polymer rubber (P2) other than the conjugated diene polymer (P1) is a copolymer of aromatic vinyl and conjugated diene, and has a Mooney viscosity of 100 to 200 ( ML _{1 + 4} , 100 ° C.) and preferably has a vinyl bond content of 7 to 85% in the conjugated diene unit.

  According to the present invention, the group further comprising 5 to 120 parts by weight of silica, clay, talc, calcium carbonate, carbon black, carbon nanotube, fullerene, nylon short fiber and aluminum hydroxide with respect to 100 parts by weight of the rubber component. An oil extended rubber composition further comprising at least one compounding agent selected from:

According to the present invention, there is provided a method for producing an oil-extended rubber composition in which a process oil is mixed with an organic solvent solution of a rubber component containing a conjugated diene polymer (P1) as an essential component and then desolvated.
Moreover, according to this invention, the member for tires formed by bridge | crosslinking the oil extended rubber composition of this invention is provided.
Furthermore, according to this invention, the tire provided with the said member for tires is provided.

The crosslinked rubber (vulcanized product) obtained by crosslinking the oil-extended rubber composition of the present invention is excellent in low heat buildup and wear resistance.
Therefore, a tire member having excellent practicality and a tire including the tire member can be obtained from the oil-extended rubber composition.

  The oil-extended rubber composition of the present invention comprises 10 to 120 parts by weight of a specific process oil in 100 parts by weight of a rubber component containing a specific conjugated diene polymer (P1) as an essential component.

  The conjugated diene polymer (P1) used in the present invention is a conjugated diene polymer having at least a butadiene unit, that is, a homopolymer of butadiene or a copolymer of butadiene and a monomer copolymerizable therewith. Have specific microstructure and molecular weight characteristics.

The conjugated diene polymer (P1) is a homopolymer of butadiene (polybutadiene) or a copolymer of butadiene and a monomer copolymerizable therewith.
The monomer copolymerizable with butadiene is not particularly limited.
Typical examples of the monomer copolymerizable with butadiene include conjugated diene monomers other than butadiene. Specific examples thereof include 1,3-butadiene, isoprene (2-methyl-1,3-butadiene), 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene, 1,3 -Pentadiene, 1,3-hexadiene, etc. are mentioned. Among these, isoprene is preferable.
These conjugated diene monomers can be used alone or in combination of two or more.

  Specific examples of monomers copolymerizable with butadiene other than conjugated dienes include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, and o-ethylstyrene. , M-ethylstyrene, p-ethylstyrene, pt-butylstyrene, α-methylstyrene, α-methyl-p-methylstyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, p-bromo Aromatic vinyl monomers such as styrene, 2-methyl-4,6-dichlorostyrene, 2,4-dibromostyrene and vinylnaphthalene; carbon number 2 such as ethylene, propylene, 1-butene, cyclopentene and 2-norbornene To 10 monoolefin monomers; 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, di Non-conjugated diene monomers having 5 to 10 carbon atoms such as cyclopentadiene and 5-ethylidene-2-norbornene; α and β having 1 to 8 carbon atoms such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate and butyl acrylate -Ethylenically unsaturated carboxylic acid alkyl ester monomer;

The ratio of butadiene units in the conjugated diene polymer (P1) is preferably 80% by weight or more, more preferably 90% by weight or more, and particularly preferably 95% by weight or more.
In addition, when a conjugated diene polymer (P1) is a copolymer, the coupling | bonding mode of a monomer is not specifically limited, For example, it can be set as various coupling | bonding modes, such as a block shape, a taper shape, and a random shape.

The conjugated diene polymer (P1) used in the present invention is required to have a cis-1,4-bond content in the butadiene unit portion of 96.5% or more, and 97.5% or more. Preferably, it is more preferably 98.0% or more.
The conjugated diene polymer (P1) needs to have a vinyl bond content in the butadiene unit portion of 1.0% or less, preferably 0.9% or less, and 0.8% or less. More preferably.

Furthermore, the conjugated diene polymer (P1) needs to have a Mooney viscosity (ML _{1 + 4} , 100 ° C.) of 65 to 200, and more preferably 75 to 175.

  Further, the conjugated diene polymer (P1) needs to have a molecular weight distribution of 1.5 to 4.0, preferably 2.0 to 3.5, and 2.0 to 3.3. Most preferably.

  The conjugated diene polymer (P1) used in the present invention uses a polymerization catalyst composed of a lanthanum series metal compound (A), an organoaluminum compound (B), an organoaluminum hydride compound (C), and a halogen compound (D). It can be obtained by polymerizing a monomer containing butadiene as an essential component.

  The lanthanum series metal compound (A), which is the first component of the polymerization catalyst, is a lanthanum series metal salt, alkoxide, phenoxide or complex, and among them, a salt is preferred.

  The lanthanum series metal is at least one metal selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium. Among these, lanthanum, cerium, praseodymium, neodymium, samarium and gadolinium are preferable, easy to obtain, easy to handle, high in polymerization activity, and high in cis-1,4-bond content in the butadiene unit portion of the resulting polymer. Therefore, neodymium is particularly preferable.

The salt of the lanthanum series metal is not particularly limited, but carboxylate and phosphate salts are preferable, and carboxylate is more preferable.
In addition, lanthanum-based metal salts have complex salt structures with different bonding modes such as complex salts of carboxylate and phosphorus-containing organic acid salt ([carboxylate] [phosphorus-containing organic acid salt]). It may be.

  Although the carboxylic acid which forms carboxylate is not specifically limited, Usually, it is a C2-C20 thing. Specific examples thereof include acetic acid, octanoic acid, octenoic acid, lauric acid, versatic acid (aliphatic monocarboxylic acid having 6 to 20 carbon atoms having a carboxyl group on a tertiary carbon in which three alkyl groups having 1 or more carbon atoms are bonded). An aliphatic carboxylic acid such as phenylacetic acid; an alicyclic carboxylic acid such as cyclopentanecarboxylic acid; an aromatic carboxylic acid such as benzoic acid and naphthenic acid; It is done. Among these, aliphatic carboxylic acids having 6 to 20 carbon atoms are preferable, and versatic acid is more preferable from the viewpoint of obtaining a catalyst with high polymerization activity.

  The phosphoric acid that forms a salt of phosphoric acid is not particularly limited, but a compound represented by the following general formula (2) is preferable.

（式中、Ｒ^３及びＲ^４は、それぞれ、水素原子、水酸基、炭素数１〜２０のアルキル基若しくはアルコキシ基、炭素数６〜２０のアリール基若しくはフェノキシ基、又は炭素数７〜２０のアラルキル基若しくはアルキルフェノキシ基を表わす。）

(Wherein R ³ and R ⁴ are each a hydrogen atom, a hydroxyl group, an alkyl group or alkoxy group having 1 to 20 carbon atoms, an aryl group or phenoxy group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms. Represents a group or an alkylphenoxy group.)

  Specific examples of the compound represented by the general formula (2) include phosphoric acid; dibutyl phosphate, dihexyl phosphate, dioctyl phosphate, bis (2-ethylhexyl phosphate), bis (1-methylheptyl) phosphate, phosphorus Dialkyl esters of phosphoric acid such as dioleyl acid, butyl phosphate (2-ethylhexyl), phosphoric acid (1-methylheptyl) (2-ethylhexyl); diaryl esters of phosphoric acid such as diphenyl phosphate; 2-ethylhexylphosphonic acid mono-2 Monoalkylphosphonic acid monoalkyl esters such as ethylhexyl and 2-ethylhexylphosphonic acid monobutyl; monoalkylphosphonic acid monoaryl esters such as 2-ethylhexylphosphonic acid monophenyl; mono-2-ethylhexyl phosphonate and mono-1-phosphonic acid Phosphonic acid such as methylheptyl Phosphonic acid monoaryl esters such as phosphonic acid monophenyl; dibutylphosphinic acid, bis (2-ethylhexyl) phosphinic acid, bis (1-methylheptyl) phosphinic acid, dioleylphosphinic acid, (2-ethylhexyl) ( 1-methylheptyl) phosphinic acid and other dialkylphosphinic acids; diphenylphosphinic acid and other diarylphosphinic acids; and the like.

  The phenol for forming the lanthanum series metal phenoxide is not particularly limited, but specific examples thereof include 2,6-di-t-butylphenol, 2,6-di-t-butyl-4-methylphenol, and the like. Mention may be made of alkyl-substituted monophenols.

Alcohol for forming the lanthanum series metal alkoxide is not particularly limited, and specific examples thereof include methanol, ethanol, isopropanol, t-butanol, t-amyl alcohol, 2-butenyl alcohol, 3-hexenyl alcohol, and the like. 1 to 10 aliphatic alcohols of the above formula; alicyclic alcohols having 3 to 6 carbon atoms such as cyclohexyl alcohol; aryl substituted aliphatic alcohols having 7 to 10 carbon atoms such as benzyl alcohol; and the like.
The lanthanum series metal complex is not particularly limited, and specific examples thereof include a β-diketone complex.
Specific examples of the β-diketone for forming the complex include β-diketone having 5 to 12 carbon atoms such as acetylacetone, benzoylacetone, and ethylacetylacetone.

In the above polymerization catalyst, the amount of component (A) used is usually 0.001 to 100 mmol, preferably 0.005 to 50, of lanthanum series metal in component (A) with respect to 1 mol of monomer. It is the range which becomes millimolar.
If this amount is excessively small, the polymerization activity may be insufficient. If it is excessively large, the molecular weight of the resulting polymer may be too small, or removal of the catalyst residue may be difficult.

The organoaluminum compound (B) that is the second component of the polymerization catalyst is represented by the general formula (3), (4), or (5).
AlR ⁵ R ⁶ R ⁷ (3)

Formula (3), (4) and ^(5), R 5 ^{to R 13} are each a hydrocarbon group of 1-20 carbon atoms. r and s are each an integer of 2 to 100.
Examples of the hydrocarbon group having 1 to 20 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, and n-pentyl group. An alkyl group having 1 to 20 carbon atoms such as n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group and n-decyl group; a cyclohexane having 3 to 6 carbon atoms such as cyclopentyl group and cyclohexyl group. Alkyl group; aralkyl group having 7 to 20 carbon atoms such as benzyl group, 2-phenylethyl group and 3-phenylpropyl group; aryl group having 6 to 20 carbon atoms such as phenyl group, 1-naphthyl group and 2-naphthyl group And the like. Among these, an alkyl group is most preferable. Further, the alkyl group, aralkyl group and aryl group may have a substituent at any position.
Among these hydrocarbon groups, those having 2 or more carbon atoms are preferable because they have high solubility in saturated hydrocarbon solvents used for polymerization and are excellent in controllability of polymer molecular weight.

  Specific examples of the organoaluminum compound represented by the general formula (3) include trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, trin-butylaluminum, triisobutylaluminum, methyldiisobutylaluminum, trin -Pentylaluminum, tri-n-hexylaluminum, tricyclohexylaluminum, tribenzylaluminum, dimethylbenzylaluminum, diethylbenzylaluminum, triphenylaluminum, tri (4-methylphenyl) aluminum, trinaphthylaluminum, phenyldimethylaluminum, phenyldiethylaluminum Etc.

  The organoaluminum compound represented by the general formula (4) or (5) is, for example, after adding trialkylaluminum, dialkylaluminum monochloride, etc. in a solvent such as benzene, toluene, cyclohexane and the like, water, copper sulfate salt And a salt having water of crystallization such as aluminum sulfate salt 16 hydrate can be added and reacted.

  Specific examples of the organoaluminum compound represented by the general formula (4) or (5) include methylalumoxane, ethylalumoxane, propylalumoxane, butylalumoxane, isobutylalumoxane, t-butylalumoxane, hexylalumoxane. Xan, octylalumoxane and the like can be mentioned. Among these, isobutylalumoxane, t-butylalumoxane, hexylalumoxane and octylalumoxane are preferable.

  As an organoaluminum compound, what is represented by the general formula (3) is preferable in terms of giving a polymer having high living properties, among others, from the viewpoint of easy availability and handling, imparting high activity to a catalyst, and the like. Triethylaluminum and triisobutylaluminum are preferred.

  The amount of component (B) in the polymerization catalyst is usually 0.5 to 500 mol, preferably 5 to 250 mol, more preferably 20 to 100 mol, per 1 mol of the lanthanum series metal in component (A). It is.

The organoaluminum hydride compound (C), which is the third component of the polymerization catalyst, is a compound represented by the following formula (6).
AlH _k R ¹⁴ _3-k (6)
(R ¹⁴ represents a hydrocarbon group having 1 to 10 carbon atoms, k is 1 or 2, and preferably 1. When k is 1, two R ¹⁴ are the same or different. May be.)

Specific examples of the hydrocarbon group R ¹⁴ having 1 to 10 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, n An alkyl group having 1 to 10 carbon atoms such as a pentyl group and an n-hexyl group; a cycloalkyl group having 3 to 6 carbon atoms such as a cyclopentyl group and a cyclohexyl group; and 7 to 7 carbon atoms such as a benzyl group and a 2-phenylethyl group 10 aralkyl groups; aryl groups having 6 to 10 carbon atoms such as phenyl groups; and the like. Among these, an alkyl group is preferable. Moreover, the alkyl group, the aralkyl group and the aryl group may have a substituent at any position.

Specific examples of the organic aluminum hydride compound (C) include methylaluminum hydride, ethylaluminum hydride, hydrogenated n-propylaluminum, hydrogenated isopropylaluminum, hydrogenated n-butylaluminum, hydrogenated isobutylaluminum, hydrogenated n Hydrocarbyl aluminum dihydride represented by the formula: AlH ₂ R ¹⁴ , such as pentyl aluminum, hydrogenated neopentyl aluminum, n-hexyl aluminum hydride, isohexyl aluminum hydride, cyclohexyl aluminum hydride, phenyl aluminum hydride; Dimethylaluminum hydride, diethylaluminum hydride, di-n-propylaluminum hydride, diisopropylaluminum hydride, di-n-butylaluminum hydride, diihydride Butylaluminum, hydrogenated di n- pentyl aluminum hydride, di-neopentyl aluminum, hydrogen di n- hexyl aluminum hydride, di-iso-hexyl aluminum hydride, dicyclohexyl aluminum, such as hydrogenated diphenyl aluminum, wherein: AlHR ¹⁴ ₂ Di (hydrocarbyl) aluminum hydride represented by:

  The amount of the component (C) in the polymerization catalyst is usually 0.1 to 100 mol, preferably 0.5 to 25 mol, more preferably 1 to 1 mol per 1 mol of the lanthanum series metal in the component (A). 3 moles.

In the polymerization catalyst, it is preferable that the molar ratio (B / C) of the organoaluminum compound (B) to the organoaluminum hydride compound (C) satisfies 5 ≦ (B / C) ≦ 1,000.
This molar ratio (B / C) is preferably 10 or more, more preferably 12 or more, preferably 500 or less, more preferably 100 or less.
A conjugated diene polymer (P1) having a narrower molecular weight distribution and a higher cis-1,4-bond content in the butadiene unit portion when the molar ratio (B / C) in the polymerization catalyst is within the above range. ) Can be obtained.

The halogen compound (D) as the fourth component of the polymerization catalyst may be a compound containing a halogen atom, and preferred specific examples thereof include a metal halide compound, a halogenated organic compound, and an organic compound. An aluminum halide compound can be mentioned.
The halogen contained in the halogen compound is preferably a chlorine, bromine or iodine atom.

Specific examples of the metal halide compound include magnesium chloride, zinc chloride, calcium chloride, magnesium iodide (II) anhydride, pentacarbonylmanganese bromide, manganese (II) perchlorate hexahydrate, manganese chloride ( II) Anhydrous, manganese chloride (II) tetrahydrate, manganese bromide (II) anhydride, manganese bromide (II) tetrahydrate, rhenium chloride (III), rhenium chloride (V), penta Examples include carbonyl rhenium chloride and pentacarbonyl rhenium bromide.
Further, it is also possible to use those obtained by reacting these metal halide compounds with a Lewis base such as a phosphorus compound, a carbonyl compound, a nitrogen compound, an ether compound, or an alcohol.

  Specific examples of halogenated organic compounds include benzoyl chloride, xylylene dichloride, bropionyl chloride, benzyl chloride, benzylidene chloride, t-butyl chloride, t-amyl chloride, chlorodiphenylmethane, chlorotriphenylmethane and methylchloroformate. Organic chlorine compounds such as hexachlorobutadiene; organic bromine compounds such as xylylene dibromide, benzoyl bromide, propionyl bromide, benzyl bromide, benzylidene bromide, t-butyl bromide, t-amyl bromide and methyl bromoformate; and benzoyl iodide, Organic iodine compounds such as xylylene diiodide are listed.

The organoaluminum halide compound is usually a compound represented by the general formula (7).
AlR ¹⁵ _p X _3-p (7)
(R ¹⁵ is a hydrocarbon group having 1 to 10 carbon atoms, X is a halogen atom, p is 1 or 2, and preferably 1. Also, when p is 2, two R ¹⁵ are The hydrocarbon group R ¹⁵ having 1 to 10 carbon atoms may be the same as the hydrocarbon group R ¹⁴ having 1 to 10 carbon atoms, and among them, an alkyl group is preferable. .)

Specific examples of organoaluminum halide compounds include dimethylaluminum chloride, dimethylaluminum bromide, diethylaluminum chloride, diethylaluminum bromide, dibutylaluminum chloride, dibutylaluminum bromide, and the like; methylaluminum sesquichloride, ethylaluminum sesquichloride, etc. Alkyl aluminum sesquihalides; alkylaluminum dihalides such as methylaluminum dichloride, ethylaluminum dichloride, butylaluminum dichloride; and the like.
These can be used alone or in combination of two or more.

  In said polymerization catalyst, the usage-amount of a component (D) is 0.1-20 mol normally with respect to 1 mol of lanthanum series metals in a component (A), Preferably it is 0.5-10 mol, More preferably 1 to 5 moles.

  By using a polymerization catalyst composed of such components (A) to (D), the Mooney viscosity is higher, the molecular weight distribution is narrower, and the cis-1,4-bond in the butadiene unit portion as compared with the conventional case. A conjugated diene polymer (P1) having a high content and a low vinyl bond content can be obtained.

The polymerization catalyst can be obtained by mixing the components (A) to (D) in an arbitrary order. After mixing the component (A) and the component (B), the mixture (C) ) Is preferably added.
More preferably, the component (A) and the component (B) are first mixed, the component (C) is blended in the obtained mixture, and then the component (D) is blended.
By mixing in this order, the polymerization activity increases, the molecular weight distribution of the resulting conjugated diene polymer (P1) becomes narrower, and the cis-1,4-bond content in the butadiene unit portion. Becomes higher.

Moreover, after mixing a component (A) and a component (B), it is preferable to age the obtained mixture for 1 minute or more, and to add a component (C) to this aged mixture.
Here, aging is to leave a certain time until the next step after mixing a certain reaction component and another reaction component.
The time for aging is preferably 1 to 60 minutes, more preferably 5 to 30 minutes. If the aging time is too short, the molecular weight distribution of the resulting conjugated diene polymer (P1) may be widened. On the other hand, if this time is too long, the polymerization activity of the resulting polymerization catalyst may be reduced.

Furthermore, after mixing component (A) and component (B), it is preferable to add conjugated diene to the resulting mixture and then add component (C).
More preferably, after mixing component (A) and component (B), conjugated diene is added to the resulting mixture, followed by component (C) and then component (D).
The addition of the conjugated diene may be performed at any time from immediately after mixing the component (A) and the component (B) to immediately before the addition of the component (C). Preferably, after mixing component (A) and component (B), the mixture is aged for 1 to 20 minutes before adding the conjugated diene, and after aging for 1 to 20 minutes, component (C) is then added. .
Moreover, the addition amount of the conjugated diene at the time of catalyst preparation is not particularly limited, but is usually 1 to 200 mol, preferably 10 to 100 mol, per 1 mol of the lanthanum series metal in the component (A).
The presence of a conjugated diene during catalyst preparation increases the polymerization activity of the catalyst, and the resulting conjugated diene polymer (P1) has a higher cis-1,4-bond content, resulting in a narrower molecular weight distribution. Become.

  As the conjugated diene used for preparing the catalyst used here, one kind may be used alone, or two or more kinds may be used in combination. Moreover, it may be the same as or different from the conjugated diene used as a monomer constituting the conjugated diene polymer (P1).

When the components (A) to (D) used as the polymerization catalyst are solid, it is preferable to use each component as a solvent solution.
Although it does not specifically limit as a solvent used here, C1-C10 linear or cyclic saturated hydrocarbon which may be substituted by the halogen atom, C6-C12 which may be substituted by the halogen atom Aromatic hydrocarbons, monoolefins and the like.
Specific examples of the linear or cyclic saturated hydrocarbon having 1 to 10 carbon atoms are not substituted with halogen atoms such as n-butane, n-pentane, n-hexane, n-heptane, n-octane, and cyclohexane. And those substituted with halogen atoms such as chloroform, methylene chloride, dichloroethane and the like.
Specific examples of the aromatic hydrocarbon include those not substituted with a halogen atom such as benzene, toluene and xylene; and those substituted with a halogen atom such as chlorobenzene.
Specific examples of monoolefins include 1-butene and 2-butene.
Among these, a linear or cyclic saturated hydrocarbon having 1 to 10 carbon atoms is preferable, and n-butane, n-pentane, n-hexane and cyclohexane are particularly preferable.

The reaction temperature and reaction time for preparing the polymerization catalyst are not particularly limited, but are usually -78 ° C to + 100 ° C, preferably -20 ° C to + 80 ° C, and usually 1 second to 24 hours.
As the polymerization catalyst, one prepared as a solution can be used as it is, or it can be used after the solvent is distilled off. Moreover, you may refine | purify as needed.

The above polymerization catalyst may be supported on a carrier such as carbon black, an inorganic compound, or an organic polymer compound. By carrying it on the carrier, it is possible to prevent contamination due to catalyst adhesion to the polymerization reactor.
Preferable examples of the inorganic compound that can be used as the carrier include inorganic oxides such as silica, alumina, magnesia, titania, zirconia, and calcia, and inorganic chlorides such as magnesium chloride. These inorganic compounds are preferably porous particles having an average particle diameter of 5 to 150 μm and a specific surface area of ² to 800 m ² / g. Usually, the inorganic compound is heat treated at 100 to 800 ° C. to remove moisture and serve as a carrier. use.
Examples of the organic polymer compound that can be used as a carrier include a carboxy-modified crosslinked styrene copolymer composed of styrene-methacrylic acid-divinylbenzene. These organic polymer compounds are preferably spherical particles having an average particle diameter of 5 to 250 μm.

In addition to the components (A) to (D), the polymerization catalyst may further contain an organometallic compound having at least one metal selected from Group 1 to 3, 12 and Group 13 elements of the periodic table. Good.
Although it does not specifically limit as this organometallic compound, For example, an organolithium compound, an organomagnesium compound, an organomagnesium halide, etc. are mentioned.
Examples of the organic lithium compound include methyl lithium, butyl lithium, and phenyl lithium.
Examples of the organic magnesium compound include dibutyl magnesium.
Examples of the organic magnesium halide include ethyl magnesium chloride and butyl magnesium chloride.

  In the present invention, the conjugated diene polymer (P1) can be obtained by copolymerizing butadiene together with other monomers copolymerizable with butadiene, if necessary, using the above polymerization catalyst.

  The polymerization method is not particularly limited, and examples thereof include a bulk polymerization method, a solution polymerization method and a slurry polymerization method in an inert solvent, and a gas phase polymerization method using a gas phase stirring tank and a gas phase fluidized bed. Among these methods, the solution polymerization method capable of narrowing the molecular weight distribution is preferable. The solution polymerization method may be a batch type or a continuous type.

The inert solvent used in the solution polymerization method is not particularly limited, but is a linear or cyclic saturated hydrocarbon having 4 to 10 carbon atoms; an aromatic hydrocarbon having 6 to 12 carbon atoms; 1-butene, 2-butene and the like These may be substituted with a halogen atom.
Saturated hydrocarbons include n-butane, cyclopentane, n-pentane, 2-methylpentane, 2,3-dimethylpentane, n-hexane, 2-methylheptane, 2,3-dimethylheptane, cycloheptane, n- Examples include heptane, n-octane, cyclooctane, and cyclohexane. Examples of the saturated hydrocarbon substituted with a halogen atom include chloroform, methylene chloride, dichloroethane and the like.
Examples of aromatic hydrocarbons include benzene, toluene, xylene and the like. Examples of the aromatic hydrocarbon substituted with a halogen atom include chlorobenzene.
Among these, a linear or cyclic saturated hydrocarbon having 4 to 10 carbon atoms is preferable, and n-butane, n-hexane, n-pentane, 2-methylpentane and cyclohexane are particularly preferable.

  The polymerization temperature for obtaining the conjugated diene polymer (P1) is usually −50 ° C. to + 200 ° C., preferably 0 ° C. to 150 ° C., more preferably 20 ° C. to 90 ° C., and most preferably 40 to 70. ° C. When the polymerization temperature is within this range, the molecular weight can be easily controlled, which is industrially advantageous. The polymerization time is about 1 second to 20 hours, and the polymerization pressure is about 0.1 to 3 MPa.

In order to adjust the molecular weight of the conjugated diene polymer (P1), a chain transfer agent can be used.
As the chain transfer agent, those conventionally used in the production of cis-1,4-polybutadiene rubber can be used. Specific examples thereof include allenes such as 1,2-butadiene; cyclic dienes such as cyclooctadiene. And the like. Further, the same effect can be obtained even when the polymerization reaction is carried out in the presence of hydrogen gas.

  The conjugated diene polymer (P1) may be modified with an organometallic halide (E) represented by the following general formula (1) following polymerization. By this modification, the solidification of the polymer when the polymer is recovered is prevented, and the industrial productivity of the polymer is improved.

（式中、Ｍは、Ｓｉ、Ｇｅ、Ｓｎ又はＴｉであり、Ｘはハロゲン原子である。Ｘが複数存在するときは、それらは、互いに同じでも異なっていてもよい。Ｒ^１は、単結合であるか、ヘテロ原子を含んでいてもよい炭素数１〜２０の炭化水素基を表す。Ｒ^２は、水素、又はヘテロ原子を含んでいてもよい炭素数１〜２０の炭化水素基を表す。Ｒ^２が複数存在するときは、それらは、互いに同じでも異なっていてもよい。ｇ及びｈは、それぞれ、１〜４の整数を表す。ｈが１のとき、ｆは０である。ｈが２〜４のとき、ｆは１であり、少なくとも１つのＲ^２はＲ^１と結合しているが、このときＲ^２は単結合であってもよい。）

(In the formula, M is Si, Ge, Sn or Ti, and X is a halogen atom. When a plurality of X are present, they may be the same as or different from each other. R ¹ is a single bond. Or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom, and R ² represents hydrogen or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. When a plurality of R ² are present, they may be the same as or different from each other, g and h each represent an integer of 1 to 4. When h is 1, f is 0. h When is 2 to 4, f is 1, and at least one R ² is bonded to R ¹ , but at this time, R ² may be a single bond.)

Specific examples of the compound represented by the general formula (1) include silicon tetrachloride, trichlorosilane, dichlorosilane, diphenyldichlorosilane, dibutyldichlorosilane, triphenylchlorosilane, tributylchlorosilane, 1,2-di (trichlorosilyl). Halogenated silicon compounds such as ethane and trichlorodisilane; halogenated germanium compounds such as triphenylgermanium chloride, dibutylgermanium dichloride, diphenylgermanium dichloride, butylgermanium trichloride; tin tetrachloride, tin tetrabromide, triphenyltin chloride, Tributyltin chloride, tri-isopropyltin chloride, diphenyltin chloride, dioctyltin dichloride, dibutyltin dichloride, phenyltin trichloride, butyltin trichloride Halogenated tin compounds and the like; titanium tetrachloride, titanium trichloro, titanium halide compounds such as dicyclopentadienyl-dichloro titanium; or the like can exhibit.
Among these, tin halide compounds and silicon halide compounds are preferable, and those having 4 or more halogen atoms such as tin tetrachloride, silicon tetrachloride, 1,2-bis (trichlorosilyl) ethane, trichlorodisilane and the like are preferable.

  The amount of the compound (E) added is preferably 0.001 to 1 mol, more preferably 0.01 to 0.1 mol, per 1 mol of the lanthanum series metal compound (A). When the addition amount is within this range, it is possible to obtain an effect that the conjugated diene polymer is excellent in exothermic property, wear property and coagulation property.

  The reaction temperature when the compound (E) is reacted is usually 20 to 100 ° C, preferably 40 to 80 ° C, more preferably 50 to 70 ° C. The reaction time is usually 1 to 120 minutes, preferably 5 to 60 minutes, more preferably 10 to 30 minutes.

  After completion of the modification reaction with the compound (E), at least one compound selected from the group consisting of an isocyanate compound, a quinone compound, an ester compound, a carbonate ester compound, a carboxylic acid and an acid halide may be added.

  The rubber component used in the oil-extended rubber composition of the present invention may be only the conjugated diene polymer (P1), but a polymer rubber other than the conjugated diene polymer (P1) and the conjugated diene polymer (P1) ( P2) may be contained.

In the oil-extended rubber composition of the present invention, the polymer rubber (P2) that can be used in combination with the conjugated diene polymer (P1) as a rubber component is not particularly limited.
Specific examples thereof include conjugated diene polymers that do not satisfy the requirements of the conjugated diene polymer (P1) with respect to molecular weight characteristics (Mooney viscosity and molecular weight distribution) and microstructure of the butadiene unit portion, and conjugated diene polymers. Other polymer rubbers may be mentioned.
Specific examples of the polymer rubber (P2) include emulsion polymerization SBR (styrene-butadiene copolymer rubber), solution polymerization random SBR (bonded styrene 5 to 50% by weight, 1,2-bond content of butadiene unit part 10 to 10%). 80%), high trans SBR (trans bond content of butadiene part 70 to 95%), low cis BR (polybutadiene rubber), high trans BR (trans bond content of butadiene part 70 to 95%), high vinyl SBR- Low vinyl SBR block copolymer rubber and other conjugated diene polymers that do not satisfy the requirements of conjugated diene polymer (P1) in terms of microstructure or molecular weight, such as natural rubber (NR), polyisoprene rubber (IR), polybutadiene rubber ( BR), styrene-isoprene copolymer rubber, butadiene-isoprene copolymer rubber, emulsion polymerization steel - acrylonitrile - butadiene copolymer rubber, acrylonitrile - butadiene copolymer rubber, polyisoprene -SBR block copolymer rubber, polystyrene - polybutadiene - can be mentioned polystyrene block copolymer.
Specific examples of the polymer rubber (P2) other than the conjugated diene polymer include acrylic rubber, epichlorohydrin rubber, fluorine rubber, silicon rubber, ethylene-propylene rubber, urethane rubber and the like.
The polymer rubber (P2) is usually a solid one, but a liquid one may be used.
These polymer rubbers (P2) can be used alone or in combination of two or more.

Among these, as the polymer rubber (P2), aromatic vinyl-conjugated diene copolymer rubber, natural rubber, polybutadiene rubber, and polyisoprene rubber are preferable, and aromatic vinyl-conjugated diene copolymer rubber is more preferable. The Mooney viscosity (ML _{1 + 4} , 100 ° C.) of the aromatic vinyl-conjugated diene copolymer rubber is preferably 100 to 200. The vinyl content in the conjugated diene unit portion of the aromatic vinyl-conjugated diene copolymer rubber is preferably 7 to 85%, more preferably 20 to 70%. The aromatic vinyl unit content of the aromatic vinyl-conjugated diene copolymer rubber is defined as St (% by weight) of the aromatic vinyl unit, and vinyl content V (%) in the conjugated diene unit part. In this case, the value of (2St + V) is preferably an amount satisfying 30 ≦ (2St + V) ≦ 170, and particularly preferably an amount satisfying 60 ≦ (2St + V) ≦ 140. When the value of (2St + V) of the aromatic vinyl-conjugated diene copolymer rubber is in the above range, the compatibility with the conjugated diene polymer (P1) is improved, and the resistance of the vulcanizate obtained from the oil-extended rubber composition is improved. Abrasion is good.

In the oil-extended rubber composition of the present invention, when the conjugated diene polymer (P1) and the polymer rubber (P2) are used in combination as the rubber component, the rubber component is 5% by weight or more of the conjugated diene polymer (P1). The polymer rubber (P2) is preferably composed of 95% by weight or less, the rubber component is 80 to 30% by weight of the conjugated diene polymer (P1), and the polymer rubber (P2) is 20 to 70% by weight. More preferably.
When the oil-extended rubber composition of the present invention is used for tire applications, the ratio of the conjugated diene polymer (P1) to the total amount of the rubber component is preferably 1% by weight or more, and is 5 to 95% by weight. It is more preferable that it is 30 to 80% by weight.

The production method of the polymer rubber (P2) used in the present invention is not particularly limited, and a conventionally known method can be employed, and examples thereof include a method of polymerizing using an organic active metal as an initiator.
The polymer rubber (P2) may be subjected to a coupling agent treatment subsequent to the polymerization. By the coupling agent treatment, the wear characteristics when the oil-extended rubber composition of the present invention is a crosslinked rubber (vulcanized product) are further improved.

Examples of coupling agents include silicon-containing coupling agents, tin-containing coupling agents, phosphorus-containing coupling agents, epoxy group-containing coupling agents, isocyanate group-containing coupling agents, ester group-containing coupling agents, and alkenyl group-containing. Examples include coupling agents and halogenated hydrocarbons.
Of these, a silicon-containing coupling agent, an epoxy group-containing coupling agent, and an isocyanate group-containing coupling agent are preferable, and a silicon-containing coupling agent and an epoxy group-containing coupling agent are more preferable.

Examples of the silicon-containing coupling agent include alkoxysilane compounds such as tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, and alkyltriphenoxysilane; silicon tetrachloride, silicon tetrabromide, silicon tetraiodide, monomethyltrichlorosilane, Halogenated silane compounds such as monoethyltrichlorosilane, monobutyltrichlorosilane, monohexyltrichlorosilane, monomethyltribromosilane, bistrichlorosilylethane; monochlorotrimethoxysilane, monobromotrimethoxysilane, dichlorodimethoxysilane, dibromodimethoxysilane, And alkoxyhalogenated silane compounds such as trichloromethoxysilane and tribromomethoxysilane;
Of these, alkoxysilane compounds and halogenated silane compounds are preferable, and tetramethoxysilane and silicon tetrachloride are more preferable.

Examples of the tin-containing coupling agent include tin halide compounds such as tin tetrachloride, tin tetrabromide, monomethyltrichlorotin, monoethyltrichlorotin, monobutyltrichlorotin, monohexyltrichlorotin, and bistrichlorostannylethane; And alkoxytin compounds such as tetramethoxytin, tetraethoxytin, and tetrabutoxytin;
Examples of the phosphorus-containing coupling agent include trisnonylphenyl phosphite, trimethyl phosphite, triethyl phosphite and the like.

Examples of the epoxy group-containing coupling agent include tetraglycidyl-1,3-bisaminomethylcyclohexane, tetraglycidyl-1,3-bisaminomethylbenzene, epoxy-modified silicone, epoxidized soybean oil, and epoxidized linseed oil. Can be mentioned.
Of these, tetraglycidyl-1,3-bisaminomethylcyclohexane is preferable.
Examples of the isocyanate group-containing coupling agent include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, diphenylethane diisocyanate, 1,3,5-benzene triisocyanate, and the like.
Of these, 2,4-tolylene diisocyanate is preferable.

Examples of the ester group-containing coupling agent include dimethyl adipate, diethyl adipate, dimethyl terephthalate, diethyl terephthalate, dimethyl phthalate, dimethyl isophthalate, and the like.
Examples of the alkenyl group-containing coupling agent include divinylbenzene and diisopropenylbenzene.
Examples of the halogenated hydrocarbon include chloroform, tribromomethane, trichloroethane, trichloropropane, tribromopropane, carbon tetrachloride, tetrachloroethane, and the like.
These coupling agents can be used alone or in combination of two or more.

The amount of the coupling agent used can be appropriately selected according to the required weight average molecular weight, coupling rate, reactivity of the coupling agent, etc., but the functional group with respect to the organic active metal in the polymerization catalyst. Is preferably 0.1 to 10 molar equivalents.
Here, the coupling rate is a ratio (% by weight) of a polymer (coupling polymer) produced by coupling a plurality of living polymers to one molecule of the coupling agent with respect to the total amount of the polymer. It can be measured by gel permeation chromatography analysis.
When the polymer rubber (P2) is coupled, the coupling ratio is preferably 10% by weight or more, more preferably 30 to 90% by weight, still more preferably 40 to 80% by weight, and particularly preferably 55 to 80% by weight. It is. If the coupling rate is excessively low, the processability may be inferior, and the low heat build-up and wear resistance may be inferior.
The coupling reaction is preferably performed at 0 to 150 ° C. under reaction conditions for 0.5 to 20 hours.

  The oil-extended rubber composition of the present invention comprises 10 to 120 parts by weight of process oil with respect to 100 parts by weight of the rubber component containing the conjugated diene polymer (P1) as an essential component.

Mineral oil and synthetic oil can be used as the process oil. As mineral oil, t-DAE, s-RAE, MES, aroma oil, naphthenic oil, paraffin oil and the like are usually used.
In the present invention, the aroma content of the process oil needs to be 5% by weight or more. The aroma content is preferably 10 to 40% by weight, and more preferably 20 to 35% by weight.
The aroma content is a ratio of the aroma content to a total of 100 aroma content, naphthene content, and paraffin content measured by the ring analysis method of ASTM D 2140.
When the aroma content is low, the wear resistance is inferior, and when it is excessively high, the low heat build-up property is inferior. In the present invention, an oil obtained by using a process oil having an aroma content within the above range. The spread rubber composition has an excellent balance between wear resistance and low heat build-up.

The oil-extended rubber composition of the present invention may contain an antiaging agent. The anti-aging agent may be added at the time of preparing the polymers (conjugated diene polymer (P1) and polymer rubber (P2)) used as the rubber component in the present invention, and the oil-extended rubber composition after the preparation of these polymers. It may be added at any stage in the process of preparing the product.
The total amount of anti-aging agent added at the time of preparation of each polymer used in the present invention (before addition of the crosslinking agent) is not particularly limited, but is usually 0.01 to 100 parts by weight with respect to a total of 100 parts by weight of the rubber component. 2 parts by weight.

The anti-aging agent is not particularly limited, and specific examples thereof include phenol-based, thioether-based and phosphorus-based anti-aging agents.
Specific examples of phenolic anti-aging agents include tetrakis [methylene-3 (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, 1,3,5-trimethyl-2, 4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t- Butylanilino) -1,3,5-triazine, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, triethylene glycol-bis [3- (3-t-butyl-5- Methyl-4-hydroxyphenyl) propionate], 1,3,5-tris- (4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid, 2,2′-methylene-bi Su- (4-methyl-6-tert-butylphenol), 3,9-bis [2- {3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethyl Ethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane, 4-hydroxymethyl-2,6-di-t-butylphenol, 2,6-di-t-butyl-4-ethylphenol Butylated hydroxyanisole, 2,2′-dihydroxy-3,3′-dicyclohexyl-5,5′-dimethyl-diphenylmethane, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butyl) Phenyl) butane, 4,4′-butylidenebis (6-tert-butyl-m-cresol, 4,4′-thiobis (3-methyl-6-tert-butylphenol), bis (3-cyclohexyl) 2-hydroxy-5-methylphenyl) methane, 2,2′-methylenebis (4-ethyl-6-tert-butyl-phenol), 1,1-bis (2′-methyl-4′-hydroxy-5 ′) -T-butyl-phenyl) butane and the like.
In addition, the phenolic anti-aging agent may have a thioether group described later.

  Specific examples of phosphorus compound anti-aging agents include tris (nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, tris (2) having one phosphorus atom in the molecule. , 5-di-t-butylphenyl) phosphite, tris (2,4-bis (1,1-dimethylpropyl) phenyl) phosphite, tridecylphosphite, octyldiphenylphosphite, di (decyl) monophenylphos Phyto, tris (3,5-di-t-butyl-4-hydroxyphenyl) phosphite, tris (mono-, di-mixed nonylphenyl) phosphite, 2,2'-methylenebis (4,6-di-t -Butylphenyl) -2-ethylhexyl phosphite, 2,2'-methylenebis (4,6-di-t-butylphenyl) -2-octa Sill phosphite, 2,2'-ethylidene-bis (4,6-di -t- butyl-phenyl) fluoro phosphite and the like.

Specific examples of the phosphorus compound anti-aging agent having two or more phosphorus atoms in the molecule include dialkylpentaerythritol diphosphites such as di (tridecyl) pentaerythritol diphosphite and distearyl pentaerythritol diphosphite; (Nonylphenyl) pentaerythritol diphosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-butylphenyl) pentaerythritol diphosphite, bis ( 2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,4-di-t-butyl-6-methylphenyl) pentaerythritol diphosphite, bis (2,6- Di-t-butyl-4-isopropylphenyl) pentaeryth Tall diphosphite, bis (2,6-di-t-butyl-4-sec-butylphenyl) pentaerythritol diphosphite, bis (2,4,6-tri-t-butylphenyl) pentaerythritol diphosphite In addition to pentaerythritol diphosphite such as diarylpentaerythritol diphosphite, tetra (tridecyl) isopropylidenediphenyl diphosphite, tetra (tridecyl) -1,1,3-tris (2-methyl-5-t - butyl-4-hydroxyphenyl) butane diphosphite, tetra _{(C 12} or _{C 15} or less of the mixed alkyl) -4,4'-isopropylidene diphenyl diphosphite, tetra (tridecyl) -4,4'-butylidene bis ( 2-t-butyl-5-methylphenyl) diphosphite, Tora (tridecyl) -4,4′-butylidenebis (3-methyl-6-tert-butylphenol) diphosphite, bis (octylphenyl) -bis [4,4′-butylidenebis (3-methyl-6-tert-butylphenol)] Examples include -1,6-hexanediol diphosphite.
A phosphite compound thermal stabilizer having two or more phosphorus atoms in the molecule is tris [2-t-butyl-4- (3-t-butyl-4-hydroxy-5-methylphenylthio) -5- It may have two or more thioether structures in the molecule, such as methylphenyl] phosphite.

  Specific examples of thioether-based anti-aging agents include dilauryl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, lauryl Stearyl-3,3′-thiodipropionate, pentaerythritol-tetrakis (3-laurylthiopropionate), 3,9-bis- (2-dodecylthioethyl) -2,4,8,10-tetraoxa Spiro [5,5] undecane; 4,6-bis (octylthiomethyl) -o-cresol, 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) Propionate], 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,5-triazi ; Or the like can be mentioned.

The oil-extended rubber composition of the present invention may further contain a reinforcing filler such as silica, carbon black, talc, calcium carbonate, clay, carbon nanotube, fullerene, nylon short fiber, and aluminum hydroxide.
In addition, the oil-extended rubber composition of the present invention includes a crosslinking agent; a crosslinking accelerator such as zinc white; a crosslinking accelerator such as sulfenamide; a processing aid such as stearic acid and its salt; a silane coupling agent; Processing stabilizers; activators such as diethylene glycol, polyethylene glycol and silicone oil; tackifiers such as petroleum resins and coumarone resins; waxes;
These compounding amounts are usually 5 to 120 parts by weight with respect to a total of 100 parts by weight of the rubber components (conjugated diene polymer (P1) and polymer rubber (P2)) used in the present invention.

  Examples of the silica compounded in the oil-extended rubber composition of the present invention include dry method white carbon, wet method white carbon, colloidal silica, and precipitated silica. Among these, wet method white carbon mainly containing hydrous silicic acid is preferable. Alternatively, a carbon-silica dual phase filler in which silica is supported on the carbon black surface may be used. These silicas can be used alone or in combination of two or more.

The nitrogen adsorption specific surface area (measured by the BET method according to ASTM D3037-81) of silica is preferably 50 to 400 m ² / g, more preferably 50 to 250 m ² / g. Within this range, the resulting oil-extended rubber composition is more excellent in wear resistance and low heat build-up. Moreover, the CDBP oil absorption of silica is preferably 50 to 400 ml / 100 g, and preferably 80 to 300 ml / 100 g. The pH of silica is preferably less than pH 7, more preferably pH 5 to 6.9. The amount of silica is preferably 5 to 120 parts by weight, more preferably 20 to 100 parts by weight, and particularly preferably 40 to 90 parts by weight with respect to 100 parts by weight of the total rubber component in the oil-extended rubber composition. It is.

In the present invention, when silica is used in the conjugated diene polymer (P1), low exothermic properties and wear resistance are further improved by adding a silane coupling agent.
Examples of the silane coupling agent include vinyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, bis (3- (Triethoxysilyl) propyl) tetrasulfide; bis (3- (triethoxysilyl) propyl) disulfide, γ-trimethoxysilylpropyldimethylthiocarbamyltetrasulfide, γ-trimethoxysilylpropylbenzothiazyltetrasulfide; (8) (wherein t is an integer of 1 to 5) and a mercapto-type silane coupling agent having an alkylene ether bond;
_{HS-C 3 H 6 -SiOC 2} H 5 (C 2 H 4 O) t CH 3 (8)

Among these silane coupling agents, mercapto-type silane coupling agents having tetrasulfide, disulfide and alkylene ether groups are preferred, and mercapto-type silane coupling agents and disulfides having alkylene ether groups are more preferred.
These silane coupling agents can be used alone or in combination of two or more.
The blending amount of the silane coupling agent is preferably 0.1 to 30 parts by weight, more preferably 1 to 15 parts by weight with respect to 100 parts by weight of silica.

Examples of carbon black blended in the oil-extended rubber composition of the present invention include furnace black, acetylene black, thermal black, channel black, and graphite. Among these, furnace black is preferable, and specific examples thereof include SAF, ISAF, ISAF-HS, ISAF-LS, IISAF-HS, HAF, HAF-HS, HAF-LS, and FEF. These carbon blacks can be used singly or in combination of two or more.
The compounding amount of carbon black is usually 150 parts by weight or less with respect to 100 parts by weight of all rubber components in the rubber composition, and the total amount of silica and carbon black is based on 100 parts by weight of all rubber components. It is preferable to be 5 to 150 parts by weight.

The nitrogen adsorption specific surface area (N ₂ SA) of carbon black is preferably 5 to 200 m ² / g, more preferably 80 to 130 m ² / g, and the dibutyl phthalate (DBP) adsorption amount is preferably 5 to 300 ml / g. 100 g, more preferably 80 to 160 ml / 100 g. Within this range, the resulting rubber composition is excellent in mechanical properties and wear resistance. Furthermore, as carbon black, the adsorption specific surface area of cetyltrimethylammonium bromide (CTAB) is 110 to 170 m ² / g, and the DBP (24M4DBP) oil absorption after repeatedly applying compression at a pressure of 165 MPa is 110 to 130 ml. When high structure carbon black of / 100 g is used, the wear resistance is further improved.

The oil-extended rubber composition of the present invention can further contain a crosslinking agent.
Examples of crosslinking agents include sulfur such as powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, and highly dispersible sulfur; sulfur halides such as sulfur monochloride and sulfur dichloride; dicumyl peroxide and ditertiary butyl peroxide. Organic peroxides; quinone dioximes such as p-quinonedioxime and p, p'-dibenzoylquinonedioxime; organics such as triethylenetetramine, hexamethylenediamine carbamate and 4,4'-methylenebis-o-chloroaniline A polyhydric amine compound; an alkylphenol resin having a methylol group; and the like. Among these, sulfur is preferable, and powdered sulfur is more preferable.
These crosslinking agents are used alone or in combination of two or more. The blending amount of the crosslinking agent is preferably 0.1 to 15 parts by weight, more preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of the total rubber component.

The crosslinking agent is preferably used in combination with a crosslinking accelerator and a crosslinking activator.
Examples of the crosslinking accelerator include N-cyclohexyl-2-benzothiazylsulfenamide, Nt-butyl-2-benzothiazolesulfenamide, N-oxyethylene-2-benzothiazolesulfenamide, N- Sulfenamide-based crosslinking accelerators such as oxyethylene-2-benzothiazole sulfenamide and N, N′-diisopropyl-2-benzothiazole sulfenamide; guanidines such as diphenylguanidine, diortolylguanidine, orthotolylbiguanidine Thiourea-based crosslinking accelerators such as diethylthiourea; thiazole-based crosslinking accelerators such as 2-mercaptobenzothiazole, dibenzothiazyl disulfide, 2-mercaptobenzothiazole zinc salt; tetramethylthiuram monosulfide, tetramethyl Thiuram-based crosslinking accelerators such as ruthiuram disulfide; Dithiocarbamic acid-based crosslinking accelerators such as sodium dimethyldithiocarbamate and zinc diethyldithiocarbamate; Xanthogenic acid-based crosslinking accelerators such as sodium isopropylxanthate, zinc isopropylxanthate, and zinc butylxanthate And the like, and the like. Of these, those containing a sulfenamide-based crosslinking accelerator are particularly preferred. These crosslinking accelerators may be used alone or in combination of two or more. The blending amount of the crosslinking accelerator is preferably 0.1 to 15 parts by weight, more preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of all rubber components.

As the crosslinking activator, for example, higher fatty acids such as stearic acid, zinc oxide and the like can be used. Zinc oxide preferably has a high surface activity particle size of 5 μm or less, and examples thereof include activated zinc flower having a particle size of 0.05 to 0.2 μm and zinc flower having a particle size of 0.3 to 1 μm. Moreover, as zinc oxide, what was surface-treated with an amine-based dispersant or wetting agent can also be used.
The blending amount of the crosslinking activator is appropriately selected, but the blending amount of the higher fatty acid is preferably 0.05 to 15 parts by weight, more preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of the total rubber component. The compounding amount of zinc oxide is preferably 0.05 to 10 parts by weight, more preferably 0.5 to 3 parts by weight with respect to 100 parts by weight of the total rubber component.
Moreover, when mix | blending a crosslinking agent with an oil extended rubber composition, you may mix | blend an additional anti-aging agent separately from the anti-aging agent which can be mix | blended previously with an oil extended rubber composition.

The oil-extended rubber composition of the present invention can be obtained by kneading each component according to a conventional method. When a cross-linking agent is included as a component of the oil-extended rubber composition, after kneading the compounding agent excluding the cross-linking agent and the cross-linking accelerator, the cross-linking agent and the cross-linking accelerator are mixed into the kneaded product to crosslink the oil-extended A rubber composition can be obtained.
The kneading temperature of the compounding agent and the rubber excluding the crosslinking agent and the crosslinking accelerator is preferably 80 to 200 ° C, more preferably 110 to 180 ° C, and the kneading time is preferably 30 seconds to 30 minutes. The mixing of the crosslinking agent and crosslinking accelerator with the kneaded product is usually performed after cooling to 100 ° C. or lower, preferably 80 ° C. or lower.

  The crosslinking method for crosslinking the crosslinkable oil-extended rubber composition is not particularly limited, and may be selected according to the shape and size of the vulcanizate. The mold may be filled with a crosslinkable oil-extended rubber composition and heated to crosslink at the same time as molding, or the preliminarily molded crosslinkable oil-extended rubber composition may be heated to crosslink. Also good. The crosslinking temperature is preferably 120 to 200 ° C, more preferably 140 to 180 ° C, and the crosslinking time is usually about 1 to 120 minutes.

In order to obtain the oil-extended rubber composition of the present invention in an industrially advantageous manner, it is possible to employ a method of removing the solvent after mixing the process oil into the organic solvent solution of the rubber component.
In addition to the process oil, each compounding agent may be added to and mixed with the organic solvent of the rubber component, and then the solvent may be removed.
Examples of the solvent removal method include a spray drying method, a steam stripping method, and a direct drying method by solvent separation using supercritical carbon dioxide. The steam stripping method is preferably employed industrially.

Applications of the oil-extended rubber composition of the present invention include tire treads, undertreads, side treads, beads, bead fillers, tire carcasses; hoses, belts, mats, anti-vibration rubber and other various industrial articles; adhesives Resin impact modifiers; resin film buffers; shoe soles, rubber shoes; golf ball cores; toys and the like.
In particular, since the oil-extended rubber composition of the present invention is excellent in low heat buildup and wear resistance, for example, as tire components and footwear such as tread, carcass, sidewall, bead portion, etc., particularly for tire red of low fuel consumption tires. It can be used suitably.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In addition, unless otherwise indicated, the part and% in an Example and a comparative example are mass references | standards.

(1) 1,4-bond content (cis, trans) and 1,2-vinyl bond content
Determine by ¹ H-NMR and ¹³ C-PST-NMR analysis.
(2) Mw and Mn
Two GMH columns manufactured by Tosoh Corporation are used in combination, and tetrahydrofuran is used as an eluent, and is obtained based on a calibration curve prepared using a standard polystyrene sample.
(3) Molecular weight distribution (Mw / Mn)
It is determined by measuring the Mw and Mn of the polymer by gel permeation chromatography.

(4) Branching rate (coupling rate) of polymer rubber (P2)
Two analytical columns GMH-HR-H manufactured by Tosoh Corporation are used in combination, and tetrahydrofuran is used as an eluent (40 ° C., 1 ml / min) based on a calibration curve created using a standard polystyrene sample. The branching rate of the polymer rubber (P2) is determined from the area ratio of the high molecular weight side peak and the low molecular weight side peak in the obtained analysis chart.
(5) Bonded styrene content
^{It is} measured by ¹ H-NMR.

(6) Solidification property Judgment is made according to the following criteria from the condition of clogging of the transfer line when pumping crumb obtained by steam stripping the polymerization solution at 105 ° C.
1: No clogging occurs.
2: The pump pressure varies from time to time, but transfer is possible.
3: Since the transfer line is sometimes clogged, it is necessary to operate while switching to a spare pump.
4: Repeated clogging 10 times or more in 1 hour (7) Mooney viscosity of polymer (ML _{1 + 4} , 100 ° C.)
Measurement is performed according to JIS K6300 using a Mooney viscometer (manufactured by Shimadzu Corporation).

(8) Low exothermic property of oil-extended rubber composition Using a viscoelasticity measuring apparatus (trade name “RDA-II”, manufactured by Rheometrics), tan δ at 60 ° C. is measured under the conditions of 0.5% twist and 20 Hz. . The result is displayed as an index for each group having the same composition. That is, Table 3 displays the measured values of Comparative Example 1 and Table 4 displays the measured values of Comparative Example 3 as 100. The smaller this index, the better the low heat buildup.

(9) Wear resistance of oil-extended rubber composition (for tire use)
Measured using a Lambourne abrasion tester according to JIS K6264. The result is displayed as an index for each group having the same composition. That is, Table 3 displays the measured values of Comparative Example 1 and Table 4 displays the measured values of Comparative Example 3 as 100. It shows that it is excellent in abrasion resistance, so that this value is high.

[Synthesis Example 1]
(Production example of neodymium versatate salt)
Versatic acid (Versatic-10, manufactured by Shell) 3.5 parts was added to 15 parts of an aqueous solution in which 0.8 parts of sodium hydroxide had been dissolved to prepare an aqueous solution of sodium versatate. Next, the above-mentioned sodium versatate aqueous solution was added dropwise to an aqueous solution in which 4 parts of neodymium chloride had been dissolved with vigorous stirring. The blue-violet viscous material formed in the aqueous solution was sufficiently washed with water and dried to obtain a neodymium salt of versatic acid.

[Synthesis Example 2]
(Preparation of catalyst solution)
1 mol of Versatic acid neodymium salt (component (A)) obtained in Synthesis Example 1 was dissolved in 200 parts of n-hexane, and 37 mol of triisobutylaluminum (TIBAL) (component (B)) was added thereto, Aged (first half aging). After 7.5 minutes, 15 mol of 1,3-butadiene (n-hexane solution) was added, and the mixture was further aged with stirring for 7.5 minutes (second half aging). Next, 1.8 mol of diisobutylaluminum hydride (DIBAH) (component (C)) and 2 mol of diethylaluminum chloride (DEAC) (component (D)) were added at room temperature. At this time, the molar (B / C) ratio between the component (B) and the component (C) is 20.6.
The resulting mixture was further stirred at room temperature for 1 hour to obtain catalyst solution 1.

[Production Example 11]
(Production of conjugated diene polymer (P1))
A jacketed reactor having a capacity of 2,000 liters was charged with 567 kg of cyclohexane and 100 kg of 1,3-butadiene so that the monomer concentration was 15%. Next, the catalyst solution 1 was added so that the molar amount of the neodymium salt was 0.15 mol, and the polymerization reaction was performed at 60 ° C. for 120 minutes with stirring (the polymerization initiation temperature and the maximum temperature during the polymerization are described in the table). After the polymerization conversion of the polymer reaches almost 100%, 0.006 mol (0.04 mol per 1 mol of neodymium (Nd)) tin tetrachloride in cyclohexane solution was added, and the modification reaction was performed for 30 minutes. Was done. The reaction was stopped by adding 3 times mole of ethanol to Nd to obtain a polymer solution having a concentration of 15% containing conjugated diene polymer P11 as conjugated diene polymer (P1). In the modification reaction, the Sn content in the polymer obtained by reprecipitation of P1 twice was determined by ICP internal standard method, and it was confirmed that the reaction rate of the modification reaction was 100%. The yield of the combined P11 is 99.2%, the cis-1,4-bond content and 1,2-vinyl bond content of the butadiene unit are 98.4% and 0.5%, respectively, and the Mooney viscosity (ML _{1 + 4} , 100 ° C.) was 81.2, and the molecular weight distribution was 2.73. The coagulation properties before and after modification with tin tetrachloride were 3 and 1, respectively.

[Production Examples 12 to 13]
Except for changing the amount of diisobutylaluminum hydride (DIBAH) (component (C)) as shown in Table 1, the same procedure as in Production Example 11 was followed to obtain polymers P12 to P13 as conjugated diene polymers (P1). It was. These yields, cis-1,4-bond content and 1,2-vinyl bond content in the butadiene unit, Mooney viscosity (ML _{1 + 4} , 100 ° C.) and molecular weight distribution, and solidification before and after modification with tin tetrachloride The properties are shown in Table 1.

[Comparative Production Example C14]
A polymer PC14 was obtained as a control conjugated diene polymer (P1) by operating in the same manner as in Production Example 11 except that the amount of diisobutylaluminum hydride (DIBAH) (component (C)) was changed as shown in Table 1. . Table 1 shows the yield, cis-1,4-bond content and 1,2-vinyl bond content, Mooney viscosity (ML _{1 + 4} , 100 ° C.) and molecular weight distribution of the butadiene unit portion.
In each table, “cis bond content” and “vinyl bond content” indicate “cis-1,4-bond content” and “1,2-vinyl bond content”, respectively.

[Production Examples 21 to 25]
A stainless steel autoclave polymerization reactor is charged with different amounts of styrene, 1,3-butadiene, cyclohexane and a small amount of tetramethylenediamine as solvents, then n-butyllithium is added as a polymerization catalyst, and the contents are stirred. The polymerization was started at 40 ° C. The internal temperature of the polymerization reactor rose to 60 ° C. After the polymerization reaction, the compounds shown in Table 2 as the coupling agent are each 0.13 mol (P21, the valence of the coupling agent is 4) and 0.13 mol per 1 mol of n-butyllithium used as the polymerization catalyst. Mol (P22, valence of coupling agent is 4), 0.125 mol (P23, valence of coupling agent is 6), 0.13 mol (P24, valence of coupling agent is 4), and 0 .13 moles (P25, coupling agent valence is 4) moles were reacted for 30 minutes, then methanol was added to stop the reaction, and the polymer was recovered by steam stripping. As a combination (P2), polymers P21 to P25 were obtained.
Table 2 shows the amount of bonded styrene (content of aromatic vinyl unit), branching rate, 1,2-vinyl bond content of butadiene unit portion, Mooney viscosity (ML _{1 + 4} , 100 ° C.), and molecular weight distribution.

[Example 1]
To a cyclohexane solution containing 100 parts of the conjugated diene polymer P11 as the conjugated diene polymer (P1) obtained in Production Example 11, aroma oil (trade name “Fukol Flex M” manufactured by Fuji Kosan Co., Ltd. 45.5%, VGC (viscosity specific gravity constant) = 0.9758) 37.5 parts, anti-aging agent 2,4-bis (n-octylthiomethyl) -6-methylphenol (Ciba Specialty) 0.15 parts (trade name “IRGANOX 1520L” manufactured by Chemicals Co., Ltd.) was added and mixed at 60 ° C. for 30 minutes, and then the polymer was precipitated by a steam stripping method and dried to give oil-extended rubber composition 1 Obtained.
Subsequently, 55 parts of silica (manufactured by Rhodia, trade name “Zeosil® 1165MP”, BET specific surface area = 160 m ^{2 /} g, pH = 6.5) was added to the oil-extended rubber composition 1 obtained, silane coupling Agent (trade name “Si75”, manufactured by Degussa), 1.5 parts of zinc oxide (zinc white # 1), 2.0 parts of stearic acid and anti-aging agent N (1,3-dimethylbutyl) -N— After blending 3 parts of phenyl-p-phenylenediamine (trade name “NOCRACK 6C” manufactured by Ouchi Shinsei Co., Ltd.) and kneading for 6 minutes in a Banbury type mixer so that the discharge temperature of the kneaded product becomes 120 ° C., The obtained mixture was transferred to an open roll at 50 ° C., and further 0.9 parts of sulfur (S # 325) and a crosslinking accelerator N- (t-butyl) -2-benzothiazole sulfenamide (manufactured by Flexis, product Name" Ntokyua TBBS ") 1.5 parts was added was kneaded to obtain a crosslinkable oil-extended rubber composition 1.
This crosslinkable oil-extended rubber composition 1 was vulcanized at 150 ° C. for 30 minutes to obtain a vulcanizate 1. Table 3 shows the results of evaluating the low heat build-up and wear resistance of the vulcanizate 1.

[Examples 2 to 4]
The process oil was changed to modified aroma oil t-DAE (manufactured by Nippon Oil Co., Ltd., aroma content 25.8%), and for Examples 3 and 4, the type of conjugated diene polymer (P1) is shown in Table 3. The oil-extended rubber compositions 2 to 4, the crosslinkable oil-extended rubber compositions 2 to 4 and the vulcanizates 2 to 4 were obtained in the same manner as in Example 1 except for changing as shown. Abrasion resistance was evaluated. The results are shown in Table 3.

[Comparative Example 1]
Instead of the conjugated diene polymer P11 as the conjugated diene polymer (P1), a commercially available cobalt catalyst butadiene rubber as the reference conjugated diene polymer [cis-1,4-bond content 96%, 1,2-vinyl Bond content 2.8%, Mooney viscosity (ML _{1 + 4} , 100 ° C.) 80.5, molecular weight distribution 2.6, manufactured by Nippon Zeon Co., Ltd., trade name “Nipol BR1441”: 37.5 parts per 100 parts of rubber Aroma oil (trade name “Fukol Flex M” manufactured by Fuji Kosan Co., Ltd.) and 0.15 part of the anti-aging agent 2,4-bis (n-octylthiomethyl) -6-methylphenol. The vulcanizate C1 was obtained by operating in the same manner as in Example 1, and its low heat build-up and wear resistance were evaluated. The results are shown in Table 3.

[Comparative Example 2]
The vulcanizate was operated in the same manner as in Example 1 except that the conjugated diene polymer P11 as the reference conjugated diene polymer (P1) was used instead of the conjugated diene polymer P11 as the conjugated diene polymer (P1). C2 was obtained and its low heat build-up and wear resistance were evaluated. The results are shown in Table 3.

  From the results of Table 3, the oil-extended rubber compositions (Examples 1 to 4) using the conjugated diene polymer (P1) satisfying the provisions of the present invention are the control conjugated diene polymers that do not satisfy the provisions of the present invention. It can be seen that the exothermic rubber composition (Comparative Examples 1 and 2) used is superior in low heat buildup and wear resistance. From the results of Example 1, it can be seen that the oil-extended diene rubber composition of the present invention is excellent in low exothermic property. Moreover, it can be seen from the comparison between Example 1 and Comparative Example 2 and the comparison between Examples 4 and 3 that the higher Mooney viscosity is more excellent in the balance between low heat build-up and wear resistance. Furthermore, it can be seen from the comparison between Example 2 and Example 4 that the higher the cis content, the better the wear resistance.

[Examples 5 to 9, Comparative Example 3]
Instead of conjugated diene polymer P11 as 100 parts of conjugated diene polymer (P1), a mixture of 60 parts of conjugated diene polymer P11 and 40 parts of natural rubber (RSS # 3) as polymer (P2) is used. The oil-extended rubber compositions 5 to 9 and C3 and the crosslinkable oil-extended rubber compositions 5 to 9 and C3 are used in the same manner as in Example 1 except that the process oil used is as shown in Table 4. Obtained. Using these crosslinkable oil-extended rubber compositions, the amount of sulfur was 1.1 parts, and 1,3-diphenylguanidine (trade name “Noxeller D”, manufactured by Ouchi Shinsei Co., Ltd.) as a crosslinking accelerator was 0. Except for using 3 parts, the same procedures as in Example 1 were carried out to obtain vulcanizates 5 to 9 and C3, and the low exothermic properties and wear resistance of the vulcanizates were evaluated. The results are shown in Table 4. In the table, CA, CN, and CP represent aroma content, naphthene content, and paraffin content, respectively.

  From the results shown in Table 4, the vulcanizate obtained from the oil-extended rubber composition obtained by using the process oil containing 5% by weight or more of the aroma content is excellent in balance between low heat buildup and wear resistance. I understand that. However, when the aroma content exceeds 40% by weight, the low heat build-up is slightly lowered (Example 9), and therefore it can be said that the aroma content is preferably between 5 and 40% by weight. .

Example 10
Conjugated diene polymer P11 as conjugated diene polymer (P1) obtained in the same manner as in Production Example 11, 37.5 parts of process oil shown in Table 5, and anti-aging agent 2,4-bis (n-octylthiomethyl) In the same manner as in Example 1, oil-extended rubber composition 1A was obtained using 0.2 parts of -6-methylphenol (trade name “IRGANOX 1520L” manufactured by Ciba Specialty Chemicals).
On the other hand, as a polymer rubber (P2), a commercially available emulsion-polymerized styrene-butadiene copolymer rubber (cis-1,4-bond content 12%, 1,2-vinyl bond content 13%, styrene content 35%, Using a 15% solution of Mooney viscosity (ML _{1 + 4} , 100 ° C.) 135, molecular weight distribution 3.8, manufactured by Nippon Zeon Co., Ltd., trade name “Nipol SBR9528R”) in cyclohexane, 37.5 parts of process oil shown in Table 5 An oil-extended rubber composition 28A was obtained in the same manner except that was used.
In a Banbury mixer, oil-extended rubber composition 1A and oil-extended rubber composition 28A each containing 50 parts of a rubber component and 18.75 parts of process oil, 40 parts of SAF carbon black, silica (manufactured by Degussa, trade name “BV7000GR”) “, BET specific surface area = 170 m 2 / g, pH = 6.5)) 40 parts, silane coupling agent (Degussa, trade name“ Si75 ”) 4 parts, wax (Ouchi Shinsei Co., trade name“ Sannok ” ”) 10 parts, 2.5 parts of zinc oxide (zinc white # 1), 1.5 parts of stearic acid and anti-aging agent N- (1,3-dimethylbutyl) -N-phenyl-p-phenylenediamine (Ouchi) 3 parts of Shinsei Co., Ltd., trade name “NOCRACK 6C”) was added and kneaded for 6 minutes so that the discharge temperature of the kneaded product was 120 ° C., and the resulting mixture was transferred to an open roll at 50 ° C. Further, 1.8 parts of sulfur (S # 325), 0.8 part of a crosslinking accelerator 1,3-diphenylguanidine (trade name “Noxeller D” manufactured by Ouchi Shinsei Co., Ltd.) and N-cyclohexyl-2-benzothiazoli 1.8 parts of rusulfenamide (trade name “Noxeller CZ-G” manufactured by Ouchi Shinsei Co., Ltd.) was added and kneaded to obtain a crosslinkable mixed oil-extended rubber composition 10.
This crosslinkable mixed oil-extended rubber composition 10 was vulcanized at 160 ° C. for 20 minutes to obtain a vulcanized product 10. Table 5 shows the results of evaluating the low heat build-up and wear resistance of the vulcanizate 10.

[Examples 11 to 13]
Crosslinkable mixed oil-extended rubber compositions 11 to 13 were obtained in the same manner as in Example 10 except that the polymers (P2) and process oils shown in Table 5 were used. From this, vulcanizates 11 to 13 were obtained in the same manner as in Example 10. Table 5 shows the results of evaluating the low heat build-up and wear resistance of these vulcanizates 11-13.
In addition, about the oil of the Example of Table 5, and the comparative example, it adjusted with mineral oil t-DAE so that it might become 50.0 parts as a total oil amount with respect to 100 parts of total rubber | gum, and it injected into the Banbury mixer.

Example 14
A rubber composition 23B was prepared in the same manner as in Example 10 except that no process oil was used in preparing an oil-extended rubber composition from the polymer P23 as the polymer (P2).
A crosslinkable mixed oil-extended rubber composition 14 was obtained in the same manner as in Example 10 except that the rubber composition 23B was used instead of the oil-extended rubber composition 28A. From this, a vulcanizate 14 was obtained in the same manner as in Example 10. Table 5 shows the results of evaluating the low heat build-up and wear resistance of the vulcanizate 14.

[Comparative Example 4]
A crosslinkable oil-extended rubber composition C4 was obtained in the same manner as in Example 11 except that the oil-extended rubber composition 1A was not used. From this, a vulcanizate C4 was obtained in the same manner as in Example 10. Table 5 shows the results of evaluating the low heat buildup and wear resistance of the vulcanizate C4.

[Examples 15 to 16]
The amount of the conjugated diene polymer P11 as the conjugated diene polymer (P1) is 50 parts, and 50 parts of the polymer P23 is used in place of 40 parts of natural rubber as the polymer (P2). Except in the same manner as in Example 10, as in Example 5 (that is, after mixing the conjugated diene polymer (P1) and the polymer (P2) in a solution and then as an oil-extended rubber), crosslinkability The mixed oil extended rubber composition 15 was obtained. From this, a vulcanizate 15 was obtained in the same manner as in Example 10. Table 5 shows the results of evaluating the low heat buildup and wear resistance of the vulcanizate 15.
Further, when obtaining a crosslinkable oil-extended rubber composition from the conjugated diene polymer P11 as the conjugated diene polymer (P1) and the polymer P23 as the polymer (P2), the amount of silica was increased by 40 parts. A crosslinkable mixed oil-extended rubber composition 16 was obtained in the same manner as in Example 15 except that the amount of the silane coupling agent was increased by 4 parts. From this, a vulcanizate 16 was obtained in the same manner as in Example 10. The results of evaluating the low heat buildup and wear resistance of this vulcanizate 16 are shown in Table 5.
From the results of Table 5, it can be seen that when the conjugated diene polymer (P1) and the polymer rubber (P2) are mixed and then used as an oil-extended rubber, the low heat buildup and wear resistance are more excellent ( Examples 15 and 16).

[Examples 17 to 22]
In a cyclohexane solution containing 30 parts of the conjugated diene polymer P12 as the conjugated diene polymer (P1) obtained in Production Example 12 and 70 parts of the polymer P23 as the polymer (P2) obtained in Production Example 23, Modified aroma oil t-DAE (manufactured by Nippon Oil Corporation, 25.8% aroma) as process oil, anti-aging agent 2,4-bis (n-octylthiomethyl) -6-methylphenol (Ciba Specialty Chemicals) (Trade name “IRGANOX 1520L”) is added and mixed at 60 ° C. for 30 minutes, and then the polymer is precipitated by a steam stripping method and dried to obtain a mixed oil-extended rubber composition 17. It was.
Subsequently, 80 parts of silica (trade name “Zeosil® 1165MP”, BET specific surface area = 160 m ^{2 /} g, pH = 6.5) manufactured by Rhodia Co., Ltd., SAF carbon was added to the obtained mixed oil-extended rubber composition 17. 10 parts of black, 5 parts of wax (made by Ouchi Shinsei Co., Ltd., trade name “Sannok”), silane coupling agent (made by Degussa, trade name “Si75”), 10% of silica, zinc oxide (zinc flower # 1) 2 parts, stearic acid 1.5 parts and anti-aging agent N- (1,3-dimethylbutyl) -N-phenyl-p-phenylenediamine (manufactured by Ouchi Shinsei Co., Ltd., trade name “NOCRACK 6C”) are added. Then, after kneading for 6 minutes so that the discharge temperature of the kneaded product becomes 120 ° C., the obtained mixture is transferred to an open roll at 50 ° C., and further 1.9 parts of sulfur (S # 325) and crosslinking accelerator 1 , 3-Diff Niruguanidine (Ouchi Shinsei Co., Ltd., trade name “Noxeller D”) 0.8 parts and N-cyclohexyl-2-benzothiazolylsulfenamide (Ouchi Shinsei Co., Ltd., trade name “Noxeller CZ-G”) 2 Part was added and kneaded to obtain a crosslinkable (mixed) oil-extended rubber composition 17.
This crosslinkable (mixed) oil-extended rubber composition 17 was vulcanized at 160 ° C. for 20 minutes to obtain a vulcanized product 17.
Further, in the same manner as in Example 17 except that the types and amounts of the conjugated diene polymer (P1), the polymer (P2) and the process oil to be used are changed as shown in Table 6, Examples 18 to 22 Mixed oil-extended rubber compositions 18-22, crosslinkable (mixed) oil-extended rubber compositions 18-22, and vulcanizates 18-22 were obtained.
Table 6 shows the results of evaluating the low heat build-up and wear resistance of vulcanizates 17-22.

[Comparative Example 5]
As the conjugated diene polymer (P1), instead of the conjugated diene polymer P12, a commercially available cobalt catalyst butadiene rubber [cis-1,4-bond content 96%, 1,2-vinyl bond content 2.8%, Mooney viscosity (ML _{1 + 4} , 100 ° C.) 80.5, molecular weight distribution 2.6. A mixed oil-extended rubber composition C5 and a crosslinkable (mixed) oil-extended rubber composition C5 were obtained in the same manner as in Example 17 except that a product name “Nipol BR1441” manufactured by Nippon Zeon Co., Ltd. was used.
From this crosslinkable (mixed) oil-extended rubber composition C5, a vulcanizate C5 was obtained in the same manner as in Example 17, and the results of evaluating this low heat buildup and wear resistance are shown in Table 6.

  From the above results, the oil-extended rubber composition of the present invention exhibits excellent characteristics as a tire member. Therefore, it can be seen that a tire including a tire member obtained by using this oil-extended rubber composition is excellent in fuel efficiency and wear resistance.

Claims (14)

Conjugated diene polymer having at least butadiene units, having a Mooney viscosity of 65 to 200 (ML _{1 + 4} , 100 ° C.) and a molecular weight distribution of 1.5 to 4.0, and 96.5% in the butadiene unit portion 100 parts by weight of a rubber component containing 5% by weight or more of an aromatic component and an aromatic component containing the above cis-1,4-bond content and a conjugated diene polymer (P1) having a vinyl bond content of 1.0% or less. An oil-extended rubber composition comprising 10 to 120 parts by weight of process oil. Conjugated diene polymer (P1) has a Mooney viscosity (ML _{1 + 4} , 100 ° C.) of 75 to 175, a molecular weight distribution of 2.0 to 3.5, and a cis-1,4-bond in the butadiene unit portion The oil-extended rubber composition according to claim 1, wherein the amount is 97.5% or more and the vinyl bond content is 0.9% or less.   The oil-extended rubber composition according to claim 1 or 2, wherein the ratio of butadiene units in the conjugated diene polymer (P1) is 80% by weight or more.   The conjugated diene polymer (P1) is essential for butadiene using a polymerization catalyst composed of a lanthanum series metal compound (A), an organoaluminum compound (B), an organoaluminum hydride compound (C), and a halogen compound (D). The oil-extended rubber composition according to any one of claims 1 to 3, wherein the oil-extended rubber composition is obtained by polymerizing a monomer as a component. A conjugated diene monomer using a polymerization catalyst in which the conjugated diene polymer (P1) is composed of a lanthanum series metal compound (A), an organoaluminum compound (B), an organoaluminum hydride compound (C), and a halogen compound (D) The oil-extended rubber composition according to claim 4, which is obtained by polymerizing and further modifying with an organometallic halide (E) represented by the following general formula (1).

(In the formula, M is Si, Ge, Sn or Ti, and X is a halogen atom. When a plurality of X are present, they may be the same as or different from each other. R ¹ is a single bond. Or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom, and R ² represents hydrogen or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. When a plurality of R ² are present, they may be the same as or different from each other, g and h each represent an integer of 1 to 4. When h is 1, f is 0. h Is 2 to 4, f is 1, and at least one R ² is bonded to R ¹ , but at this time R ² may be a single bond).   The polymerization catalyst is composed of a lanthanum series metal compound (A), an organic alkylaluminum compound (B), an organic aluminum hydride compound (C), and a halogen compound (D), and the organic alkylaluminum compound (B) The oil-extended rubber according to claim 4 or 5, wherein the molar ratio (B / C) with the organoaluminum hydride compound (C) satisfies 5≤ (B / C) ≤1,000. Composition.   The oil-extended rubber composition according to any one of claims 1 to 6, wherein the process oil contains 10 to 40% by weight of aroma.   The oil-extended rubber composition according to any one of claims 1 to 7, wherein the rubber component comprises only a conjugated diene polymer (P1).   The rubber component is composed of 5% by weight or more of the conjugated diene polymer (P1) and 95% by weight or less of the polymer rubber (P2) other than the conjugated diene polymer (P1). 8. The oil-extended rubber composition according to any one of items 7. The polymer rubber (P2) other than the conjugated diene polymer (P1) is a copolymer of aromatic vinyl and conjugated diene, and has a Mooney viscosity (ML _{1 + 4} , 100 ° C.) of 100 to 200, and a conjugated diene unit. The oil-extended rubber composition according to claim 9, which has a vinyl bond content of 7 to 85%.   5 to 120 parts by weight of at least one compounding agent selected from the group consisting of silica, clay, talc, calcium carbonate, carbon black, carbon nanotube, fullerene, nylon short fiber, and aluminum hydroxide with respect to 100 parts by weight of the rubber component The oil-extended rubber composition according to any one of claims 1 to 10, further comprising:   The oil-extended rubber according to any one of claims 1 to 11, wherein the process oil is mixed with an organic solvent solution of a rubber component containing the conjugated diene polymer (P1) as an essential component, and then the solvent is removed. A method for producing the composition.   A tire member obtained by crosslinking the oil-extended rubber composition according to any one of claims 1 to 11.   A tire comprising the tire member according to claim 13.