JP2011089066A - Tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire being excellent in on-ice performance, steering stability on a dry road surface and wear-resistance and having small rolling resistance. <P>SOLUTION: The tire is characterized in that a rubber composition in which 5-50 pts.mass of a low molecular weight modified conjugated diene based polymer having a weight average molecular weight before modification of 2×10<SP>3</SP>-15×10<SP>4</SP>and 20-200 pts.mass of a reinforcing filler are formulated relative to 100 pts.mass of a rubber matrix containing a modified diene based rubber in which a polar group-containing hydrazide compound is added to a terminal end of a molecule chain of the diene based rubber after the diene based rubber latex is oxidized and a high molecular weight modified conjugated diene based polymer having a weight average molecular weight before modification of the value exceeding 15×10<SP>4</SP>-200×10<SP>4</SP>is used for any one of tire members. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a tire, and more particularly, to a tire having excellent performance on ice, steering stability on a dry road surface, and wear resistance, and low rolling resistance.

  Conventional winter tires have a low glass transition point (Tg) in order to improve performance on ice, and are at a low temperature (here, low temperature is a temperature during running on ice, which is about −20 to 0 ° C.). Many of these have a low elastic modulus. However, in general, lowering the elastic modulus at low temperatures also tends to lower the elastic modulus at high temperatures, so conventional winter tires have high heat generation and rolling resistance (RR), as well as handling stability on dry road surfaces. (Hereinafter, also referred to as “dry steering stability performance”) has a problem of low.

  On the other hand, in patent document 1, a foaming agent is mix | blended with a rubber matrix (rubber component), the bubble rate after vulcanization, and the dynamic elastic modulus in 0 degreeC and 60 degreeC are in a specific range. There has been proposed a winter tire (studless tire) using a rubber composition as a tread rubber of a tire and using a modified conjugated diene polymer having a tertiary amino group-containing functional group as a rubber matrix of the rubber composition. . In this proposal, using a modified conjugated diene polymer having a tertiary amino group-containing functional group, it was possible to achieve both a certain degree of performance on ice and a low rolling resistance.

  On the other hand, there is an increasing demand for lower fuel consumption of automobiles, and tires with low rolling resistance are required. Therefore, as a rubber composition used for tire treads or the like, a rubber composition having a low tan δ (hereinafter referred to as low loss property) and excellent in low heat generation properties is required. In addition, a rubber composition for a tread is required to have excellent wear resistance and fracture characteristics in addition to low loss.

JP 2004-238619A

  Under such circumstances, an object of the present invention is to provide a tire that has excellent performance on ice, steering stability on a dry road surface and wear resistance, and has low rolling resistance.

  As a result of intensive studies to achieve the above object, the present inventor has found that a low-molecular weight modified conjugated diene polymer and a reinforcing property with respect to a rubber matrix containing a specific modified diene rubber and a high molecular weight modified conjugated diene polymer. By using a rubber composition containing a specific amount of filler, it has been found that a tire with excellent performance on ice, steering stability on dry roads and wear resistance, and low rolling resistance can be obtained, and the present invention has been completed. I came to let you.

That is, the tire of the present invention comprises a modified diene rubber obtained by oxidizing a diene rubber latex and then adding a polar group-containing hydrazide compound to the end of the molecular chain of the diene rubber, and a weight average molecular weight of 15 before modification. The weight average molecular weight before modification is 2 × 10 ³ to 15 × 10 ⁴ with respect to 100 parts by mass of the rubber matrix containing × 10 ⁴ and 200 × 10 ⁴ or more of the high molecular weight modified conjugated diene polymer. A rubber composition comprising 5 to 50 parts by mass of a low molecular weight modified conjugated diene polymer and 20 to 200 parts by mass of a reinforcing filler is used for any of the tire members.

  In the tire of the present invention, the bonded aromatic vinyl content (X) (% by mass) of the low molecular weight modified conjugated diene polymer and the vinyl bond content (Y) (%) of the conjugated diene moiety are X + (Y / 2) It is preferable to satisfy <25.

  In a preferred embodiment of the tire of the present invention, the low molecular weight modified conjugated diene polymer contains at least one functional group selected from the group consisting of a tin-containing functional group, a silicon-containing functional group, and a nitrogen-containing functional group. .

  In another preferred embodiment of the tire of the present invention, the low molecular weight modified conjugated diene polymer is low molecular weight modified polybutadiene and / or low molecular weight modified polyisoprene.

  In another preferred embodiment of the tire of the present invention, the high molecular weight modified conjugated diene polymer has at least one functional group selected from the group consisting of a tin-containing functional group, a silicon-containing functional group, and a nitrogen-containing functional group. contains.

  In another preferred embodiment of the tire of the present invention, the high molecular weight modified conjugated diene polymer is a modified polybutadiene rubber and / or a modified polyisoprene rubber.

  In another preferred embodiment of the tire of the present invention, the reinforcing filler is carbon black and / or silica.

  In another preferred embodiment of the tire of the present invention, the rubber matrix comprises a total of 10 to 100% by mass of the modified diene rubber and the high molecular weight modified conjugated diene polymer, and 90 to 0% by mass of the diene rubber. Consists of.

  In another preferred embodiment of the tire of the present invention, the rubber composition further contains 3 to 30 parts by mass of fine particles having an average major axis of 5 to 1000 μm with respect to 100 parts by mass of the rubber matrix.

  In another preferred embodiment of the tire of the present invention, the silicon-containing functional group is a dialkoxysilane compound residue or a trialkoxysilane compound residue.

  In another preferred embodiment of the tire of the present invention, the nitrogen-containing functional group or the silicon-containing functional group has a primary amino group.

［式中、Ｒ¹及びＲ³は夫々独立に−ＯＲ、−ＯＨ又は炭素数１〜２０のアルキル基であり、Ｒ²は炭素数１〜２０のアルキレン基であり、Ｒは硫黄原子、酸素原子、窒素原子及び／又はハロゲン原子を有していても良い炭素数１〜２０のヒドロカルビル基である］

［式中、Ｒ⁴及びＲ⁶は夫々独立に−ＯＲ、−ＯＨ又は炭素数１〜２０のアルキル基であり、Ｒ⁵及びＲ⁷は夫々独立に炭素数１〜２０のアルキレン基であり、Ｒは硫黄原子、酸素原子、窒素原子及び／又はハロゲン原子を有していても良い炭素数１〜２０のヒドロカルビル基であり、ＭはＳｉ、Ｔｉ、Ｓｎ、Ｂｉ、Ｚｒ又はＡｌであり、Ｒ⁸は−ＯＨ、炭素数１〜３０のヒドロカルビル基、炭素数２〜３０のヒドロカルビルカルボキシル基、炭素数５〜２０の１，３−ジカルボニル含有基、炭素数１〜２０のヒドロカルビルオキシ基、並びに炭素数１〜２０のヒドロカルビル基及び／又は炭素数１〜２０のヒドロカルビルオキシ基で三置換されたシロキシ基からなる群から選ばれる基であり、複数のＲ⁸は同一でも異なっていても良く、ｋは｛（Ｍの価数）−２｝であり、ｎは０又は１である］ In another preferred embodiment of the tire of the present invention, the low molecular weight modified conjugated diene polymer and / or the high molecular weight modified conjugated diene polymer is represented by the following general formula (1) or the following general formula (2). It is.

[Wherein, R ¹ and R ³ are each independently —OR, —OH or an alkyl group having 1 to 20 carbon atoms, R ² is an alkylene group having 1 to 20 carbon atoms, and R is a sulfur atom, oxygen It is a C1-C20 hydrocarbyl group which may have an atom, nitrogen atom and / or halogen atom]

[Wherein, R ⁴ and R ⁶ are each independently —OR, —OH or an alkyl group having 1 to 20 carbon atoms, and R ⁵ and R ⁷ are each independently an alkylene group having 1 to 20 carbon atoms, R is a hydrocarbyl group having 1 to 20 carbon atoms which may have a sulfur atom, an oxygen atom, a nitrogen atom and / or a halogen atom, M is Si, Ti, Sn, Bi, Zr or Al; ⁸ is —OH, a hydrocarbyl group having 1 to 30 carbon atoms, a hydrocarbyl carboxyl group having 2 to 30 carbon atoms, a 1,3-dicarbonyl-containing group having 5 to 20 carbon atoms, a hydrocarbyloxy group having 1 to 20 carbon atoms, and A group selected from the group consisting of a siloxy group trisubstituted with a hydrocarbyl group having 1 to 20 carbon atoms and / or a hydrocarbyloxy group having 1 to 20 carbon atoms, and a plurality of R ⁸ may be the same or different; k is { M is the number of valence) -2}, n is 0 or 1]

  In another preferred embodiment of the tire of the present invention, the low molecular weight modified conjugated diene polymer and / or the high molecular weight modified conjugated diene polymer has a CN bond at the polymerization initiation terminal of the polymer.

  In another preferred embodiment of the tire of the present invention, the diene rubber latex is a natural rubber latex.

  In the tire of this invention, it is preferable that the addition amount of the said polar group containing hydrazide compound is 0.01-5.0 mass% with respect to the rubber component in the said diene rubber latex.

  In another preferred embodiment of the tire of the present invention, the polar group of the polar group-containing hydrazide compound is amino group, imino group, nitrile group, ammonium group, imide group, amide group, hydrazo group, azo group, diazo group, hydroxyl group. And at least one selected from the group consisting of a group, a carboxyl group, a carbonyl group, an epoxy group, an oxycarbonyl group, a nitrogen-containing heterocyclic group, an oxygen-containing heterocyclic group, a tin-containing group and an alkoxysilyl group.

  In the tire of the present invention, the modified diene rubber preferably has a polystyrene equivalent weight average molecular weight of 200,000 or more as measured by gel permeation chromatography.

  In the tire of the present invention, the oxidation of the diene rubber latex is preferably performed by adding a carbonyl compound to the diene rubber latex and performing air oxidation, and the air oxidation is performed in the presence of a radical generator. Is more preferable. Here, the carbonyl compound is preferably an aldehyde and / or a ketone, and the radical generator is preferably a peroxide radical generator, a redox radical generator or an azo radical generator.

（式中、Ｒ^Iは、置換基としてアミノ基、イミノ基、ニトリル基、アンモニウム基、イミド基、アミド基、ヒドラゾ基、アゾ基、ジアゾ基、ヒドロキシル基、カルボキシル基、カルボニル基、エポキシ基、オキシカルボニル基、スズ含有基、アルコキシシリル基からなる群から選ばれる極性基を少なくとも１種有する炭素数１〜４のアルキレン基、置換基として該極性基を少なくとも１種有するフェニレン基、又は含窒素複素環基及び含酸素複素環基からなる群から選ばれる少なくとも１種の極性基である）で表される極性基含有官能基を有する。 In another preferred embodiment of the tire according to the present invention, the modified diene rubber has the following general formula (I) at the end of the molecular chain of the diene rubber:

(In the formula, R ^I is an amino group, imino group, nitrile group, ammonium group, imide group, amide group, hydrazo group, azo group, diazo group, hydroxyl group, carboxyl group, carbonyl group, epoxy group, An alkylene group having 1 to 4 carbon atoms having at least one polar group selected from the group consisting of an oxycarbonyl group, a tin-containing group and an alkoxysilyl group, a phenylene group having at least one polar group as a substituent, or nitrogen-containing A polar group-containing functional group represented by at least one polar group selected from the group consisting of a heterocyclic group and an oxygen-containing heterocyclic group.

  In another preferred embodiment of the tire of the present invention, the tire member is a tread.

  In another preferred embodiment of the tire of the present invention, the rubber composition has 5 to 50% by volume of air bubbles in the rubber matrix after vulcanization.

  The method for producing the modified diene rubber is as follows: (1) Oxidizing and coagulating the diene rubber latex, adding a polar group-containing hydrazide compound to the solidified product of the oxidized diene rubber latex, A method in which a polar group-containing hydrazide compound is added to the end of the molecular chain of the diene rubber in the coagulated product of the oxidized diene rubber latex and further dried. (2) The diene rubber latex is oxidized, and further coagulated and dried. And adding a polar group-containing hydrazide compound to the obtained diene rubber and adding the polar group-containing hydrazide compound to the end of the molecular chain of the diene rubber in the oxidized diene rubber, and (3 ) Oxidizing diene rubber latex, adding polar group-containing hydrazide compound to the resulting oxidized diene rubber latex, and adding the polar group-containing hydrazide compound The by addition reaction to the end of the molecular chain of diene rubber of the oxidized diene rubber latex, it is preferred approach to further coagulation and drying.

  According to the present invention, a rubber composition containing a specific amount of a low molecular weight modified conjugated diene polymer and a reinforcing filler in a rubber matrix containing a specific modified diene rubber and a high molecular weight modified conjugated diene polymer. Can be used for any of the tire members to provide a tire having excellent performance on ice, stable driving performance on dry road surfaces, and wear resistance, and low rolling resistance.

The present invention is described in detail below. The tire of the present invention comprises a modified diene rubber obtained by oxidizing a diene rubber latex and then adding a polar group-containing hydrazide compound to the end of the molecular chain of the diene rubber, and a weight average molecular weight before modification of 15 × 10. Low molecular weight having a weight average molecular weight of 2 × 10 ³ to 15 × 10 ⁴ before modification with respect to 100 parts by mass of a rubber matrix containing a high molecular weight modified conjugated diene polymer that is more than ⁴ and not more than 200 × 10 ⁴ A rubber composition comprising 5 to 50 parts by mass of a modified conjugated diene polymer and 20 to 200 parts by mass of a reinforcing filler is used for any tire member.

  In the rubber matrix of the rubber composition used in the tire of the present invention, the modified diene rubber is obtained by oxidizing a diene rubber latex and then adding a polar group-containing hydrazide compound to the end of the molecular chain of the diene rubber. Features. In the modified diene rubber, a polar group is present at the end of the molecular chain of the diene rubber, and therefore, a polar group such as the modified natural rubber described in International Publication No. 2004/106397 is present in the molecular chain. It has better affinity for various fillers such as carbon black and silica than modified diene rubber. The rubber composition using the above-described modified diene rubber as a rubber component is more filled with the rubber component than the rubber composition using the above-described modified diene rubber having a polar group in the molecular chain as the rubber component. The dispersibility of the agent is high, the reinforcing effect of the filler is sufficiently exhibited, and the wear resistance and low loss (low heat generation) are improved. Further, by using the rubber composition for a tire, particularly a tread of the tire, the wear resistance can be remarkably improved while significantly reducing the rolling resistance.

  In the modified diene rubber, the diene rubber latex used for the oxidation reaction includes natural rubber latex, polyisoprene rubber latex, styrene-butadiene copolymer rubber latex, polybutadiene rubber latex, acrylonitrile-butadiene rubber latex, chloroprene rubber latex, etc. Is mentioned. The diene rubber latex may be used alone or in combination of two or more. Among these, in the case of synthetic rubber, it is possible to introduce a polar group at the end of the molecular chain during the polymerization process, but natural rubber, which is a natural product, is not possible except by a method using a metathesis catalyst. Considering that the present invention makes it possible, it is preferable to use natural rubber latex.

  As the natural rubber latex, any of field latex, ammonia-treated latex, centrifugal concentrated latex, deproteinized latex treated with a surfactant or an enzyme, and combinations of the above can be used. In order to reduce side reactions, it is preferable to increase the purity of natural rubber latex.

  The oxidation of the diene rubber latex can be performed by a known method. For example, according to JP-A-8-81505, oxidation of the diene rubber latex is performed by air oxidation of the diene rubber latex dissolved in an organic solvent at a ratio of 1 to 30% by mass in the presence of a metal oxidation catalyst. It can be performed. Here, suitable metal species of the metal-based oxidation catalyst used for promoting air oxidation are cobalt, copper, iron, and the like, and salts and complexes with these chlorides and organic compounds are used. Of these, cobalt catalysts such as cobalt chloride, cobalt acetylacetonate, and cobalt naphthenate are preferable.

  The organic solvent may be any hydrocarbon solvent, aromatic hydrocarbon solvent, organic solvent as long as it does not react with the rubber and is not easily oxidized and dissolves the rubber. A halogen-based solvent or the like is preferably used. As the hydrocarbon solvent, for example, hexane, gasoline or the like can be used. As the aromatic hydrocarbon solvent, for example, toluene, xylene, benzene and the like can be used. As the organic halogen solvent, for example, chloroform, dichloromethane and the like can be used. Of these, aromatic hydrocarbon-based toluene is preferably used. It is also possible to use a mixed solvent of them and alcohol.

  Further, as described in JP-A-9-136903, the diene rubber latex can be oxidized by adding a carbonyl compound to the diene rubber latex and oxidizing the diene rubber latex with air. it can. It is appropriate that the carbonyl compound added to the diene rubber latex is added so as to be 20 volume% (V / V%) or less, preferably 0.5 to 10 volume% based on the latex volume regardless of the rubber content. It is. Even if the concentration of the carbonyl compound exceeds the above range, there is no problem, but not only the reactivity is not increased, but there is a risk that it is economically disadvantageous. Here, preferable examples of the carbonyl compound include various aldehydes and ketones.

  Here, as aldehydes, for example, formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, n-valeraldehyde, caproaldehyde, heptaldehyde, phenylacetaldehyde, benzaldehyde, tolualdehyde, nitrobenzaldehyde, salicylaldehyde, anisaldehyde, Examples include vanillin, piperonal, methyl valeraldehyde, isocaproaldehyde, paraformaldehyde and the like.

  On the other hand, examples of ketones include acetone, methyl ethyl ketone, methyl n-propyl ketone, diethyl ketone, isopropyl methyl ketone, benzyl methyl ketone, 2-hexanone, 3-hexanone, isobutyl methyl ketone, acetophenone, propiophenone, and n-butyrophenone. , Benzophenone, 3-nitro-4′-methylbenzophenone, and the like.

  Air oxidation can be performed by adding the carbonyl compound described above to the diene rubber latex. However, as described in JP-A-9-136903, a radical generator is used to promote air oxidation. Air oxidation is preferably performed in the presence. As the radical generator, for example, a peroxide radical generator, a redox radical generator, an azo radical generator and the like are preferably used. Examples of peroxide radical generators include benzoyl peroxide, di-t-butyl peroxide, potassium persulfate, ammonium persulfate, hydrogen peroxide, lauroyl peroxide, diisopropyl peroxycarbonate, dicyclohexyl peroxycarbonate, etc. it can.

  Examples of the redox radical generator include cumene hydroxyperoxide and Fe (II) salt, hydrogen peroxide and Fe (II) salt, potassium persulfate or ammonium persulfate and sodium sulfite, sodium perchlorate and sodium sulfite, cerium sulfate ( IV) and alcohols, amines or starches, peroxides such as benzoyl peroxide and lauroyl peroxide, dimethylaniline, tert-butyl hydroperoxide, tetraethylenepentamine and the like.

  As the azo radical generator, for example, azobisisobutyronitrile, methyl azobisisobutyrate, azobiscyclohexanecarbonitrile, azobisisobutylamidine hydrochloride, 4,4′-azobis-4-cyanovaleric acid and the like can be used.

  The above radical generator is used by dissolving or dispersing in the diene rubber latex. The addition amount of the radical generator is suitably 0.01 to 5% by mass, preferably 0.05 to 1% by mass, based on the diene rubber solid content. If the concentration of the radical generator is lower than the above range, the rate of air oxidation is slow and impractical. On the other hand, when the concentration of the radical generator exceeds the above range, molecular chain scission proceeds, and as the molecular weight decreases, the low loss property, wear resistance, and breaking strength of the rubber composition may deteriorate.

  In air oxidation, it is desirable to bring the solution into uniform contact with air. Although the method for making the contact with air uniform is not particularly limited, for example, in addition to shaking in a shake flask, it can be easily performed by stirring, bubbling for blowing air, or the like. Although the temperature which advances air oxidation is normally performed at room temperature-100 degreeC, it is not specifically limited. The reaction is usually completed in about 1 to 5 hours.

  Further, according to the description in JP-A No. 2001-261707, an ozone-containing gas can be blown into the diene rubber latex, and the diene rubber latex can be oxidized by the oxidizing action of ozone. In this method, the decomposition reaction is accelerated by the addition of hydrogen peroxide.

  In the present invention, the diene rubber latex is oxidized by the above method, and then the polar group-containing hydrazide compound is added. Here, as described later, a polar group-containing hydrazide compound may be added to the oxidized diene rubber latex obtained by oxidizing the diene rubber latex, or the obtained oxidized diene rubber latex is coagulated. A polar group-containing hydrazide compound may be added to the obtained diene rubber.

  The oxidized diene rubber latex obtained by the above method has a carbonyl group at the end of the diene rubber molecular chain. The polar group-containing hydrazide compound has high reactivity, and therefore, the carbonyl group at the end of the diene rubber molecule in the oxidized diene rubber latex or the oxidized diene rubber obtained by coagulating the oxidized diene rubber latex It reacts easily. Therefore, by adding a polar group-containing hydrazide compound to oxidized diene rubber latex or oxidized diene rubber, it is possible to easily and inexpensively introduce polar groups at the end of the diene rubber molecule without using an expensive catalyst. it can.

  The polar group-containing hydrazide compound is not particularly limited as long as it is a hydrazide compound having at least one polar group in the molecule. Here, specific examples of the polar group of the polar group-containing hydrazide compound include an amino group, an imino group, a nitrile group, an ammonium group, an imide group, an amide group, a hydrazo group, an azo group, a diazo group, and a hydroxyl group. Preferred examples include a carboxyl group, a carbonyl group, an epoxy group, an oxycarbonyl group, a nitrogen-containing heterocyclic group, an oxygen-containing heterocyclic group, a tin-containing group, and an alkoxysilyl group. These polar group-containing hydrazide compounds can be used alone or in combination of two or more.

  Examples of the amino group-containing hydrazide compound include hydrazide compounds having at least one amino group selected from primary, secondary, and tertiary amino groups in one molecule. These amino group-containing hydrazide compounds can be used alone or in combination of two or more.

  Examples of the primary amino group-containing hydrazide compound include 2-aminoacetohydrazide, 3-aminopropanoic acid hydrazide, 4-aminobutanoic acid hydrazide, 2-aminobenzohydrazide, 4-aminobenzohydrazide and the like.

  Examples of secondary amino group-containing hydrazide compounds include 2- (methylamino) acetohydrazide, 2- (ethylamino) acetohydrazide, 3- (methylamino) propanoic acid hydrazide, and 3- (ethylamino) propanoic acid hydrazide. 3- (propylamino) propanoic hydrazide, 3- (isopropylamino) propanoic hydrazide, 4- (methylamino) butanoic hydrazide, 4- (ethylamino) butanoic hydrazide, 4- (propylamino) butanoic hydrazide 4- (isopropylamino) butanoic hydrazide, 2- (methylamino) benzohydrazide, 2- (ethylamino) benzohydrazide, 2- (propylamino) benzohydrazide, 2- (isopropylamino) benzohydrazide, 4- ( Methylamino) benzohydradi , 4 one (ethylamino) benzohydrazide, 4- (propylamino) benzohydrazide, 4- (isopropylamino) benzohydrazide, and the like.

  Examples of tertiary amino group-containing hydrazide compounds include N, N-disubstituted aminocarboxylic acid hydrazide compounds and N, N-disubstituted benzohydrazide compounds. Examples of these compounds include 2- (dimethylamino) acetohydrazide, 2- (diethylamino) acetohydrazide, 3- (dimethylamino) propanoic acid hydrazide, 3- (diethylamino) propanoic acid hydrazide, and 3- (dipropylamino). ) Propanoic hydrazide, 3- (diisopropylamino) propanoic hydrazide, 4- (dimethylamino) butanoic hydrazide, 4- (diethylamino) butanoic hydrazide, 4- (dipropylamino) butanoic hydrazide, 4- (diisopropylamino) ) Butanoic acid hydrazide, 2- (dimethylamino) benzohydrazide, 2- (diethylamino) benzohydrazide, 2- (dipropylamino) benzohydrazide, 2- (diisopropylamino) benzohydrazide, 4- (dimethylamino) ben Hydrazide, 4- (diethylamino) benzohydrazide, 4- (dipropylamino) benzohydrazide, 4- (diisopropylamino) benzohydrazide, and the like.

  Further, it may be a nitrogen-containing heterocyclic group instead of an amino group. Examples of the nitrogen-containing heterocyclic group include pyrrole, histidine, imidazole, triazolidine, triazole, triazine, pyridine, pyrimidine, pyrazine, indole, quinoline. , Purine, phenazine, pteridine, melamine and the like. The heteronitrogen heterocycle may contain other heteroatoms in the ring. Here, examples of the hydrazide compound having a pyridyl group as a nitrogen-containing heterocyclic group include isonicotinohydrazide and picolinohydrazide. These nitrogen-containing heterocyclic group-containing hydrazide compounds may be used alone or in combination of two or more.

  Examples of the hydrazide compound having a nitrile group include 2-nitroacetohydrazide, 3-nitropropanoic acid hydrazide, 4-nitrobutanoic acid hydrazide, 2-nitrobenzohydrazide, 4-nitrobenzohydrazide and the like. These nitrile group-containing hydrazide compounds may be used alone or in a combination of two or more.

  Examples of the hydroxyl group-containing hydrazide compound include hydrazide compounds containing at least one primary, secondary, or tertiary hydroxyl group in one molecule. Examples of such hydroxyl group-containing hydrazide compounds include 2-hydroxyacetohydrazide, 3-hydroxypropanoic hydrazide, 4-hydroxybutanoic hydrazide, 2-hydroxybenzohydrazide, and 4-hydroxybenzohydrazide. These hydroxyl group-containing hydrazide compounds may be used alone or in a combination of two or more.

  Examples of the hydrazide compound containing a carboxyl group include 3-carboxypropanoic acid hydrazide, 4-carboxybutanoic acid hydrazide, 2-carboxybenzoic acid hydrazide, 4-carboxybenzoic acid hydrazide, and the like. These carboxyl group-containing hydrazide compounds may be used individually by 1 type, and may be used in combination of 2 or more type.

  Examples of the hydrazide compound having an epoxy group include 2- (oxiran-2-yl) acetohydrazide, 3- (oxiran-2-yl) propanoic acid hydrazide, and 3- (tetrahydro-2H-pyran-4-yl) propanoic acid. And hydrazide. These epoxy group-containing hydrazide compounds may be used alone or in a combination of two or more.

  Examples of the hydrazide compound having a tin-containing group include 3- (tributyltin) propanoic hydrazide, 3- (trimethyltin) propanoic hydrazide, 3- (triphenyltin) propanoic hydrazide, and 3- (trioctyltin) propanoic acid. Hydrazide, 4- (tributyltin) butanoic hydrazide, 4- (trimethyltin) butanoic hydrazide, 4- (triphenyltin) butanoic hydrazide, 4- (trioctyltin) butanoic hydrazide, 2- (tributyltin) benzohydrazide , 4- (tributyltin) benzohydrazide, 2- (trimethyltin) benzohydrazide, 4- (trimethyltin) benzohydrazide, 2- (trioctyltin) benzohydrazide, 4- (trioctyltin) benzohydrazide, etc. Hydrazide formation Mention may be made of things. These tin-containing hydrazide compounds may be used individually by 1 type, and may be used in combination of 2 or more type.

  Examples of the hydrazide compound containing an alkoxysilyl group include 2- (trimethoxysilyl) acetohydrazide, 2- (triethoxysilyl) acetohydrazide, 3- (trimethoxysilyl) propanoic acid hydrazide, and 3- (triethoxysilyl). Propanoic acid hydrazide, 4- (trimethoxysilyl) butanoic acid hydrazide, 4- (triethoxysilyl) butanoic acid hydrazide, 2- (trimethoxysilyl) benzohydrazide, 2- (triethoxysilyl) benzohydrazide, 4- (tri Methoxysilyl) benzohydrazide, 4- (triethoxysilyl) benzohydrazide and the like. These alkoxysilyl group-containing hydrazide compounds may be used individually by 1 type, and may be used in combination of 2 or more type.

  There are three methods for adding the polar group-containing hydrazide compound as follows. In the first method, the oxidized diene rubber latex is coagulated, pulverized and crushed, and then the polar group-containing hydrazide compound is added. Thereafter, kneading is performed using, for example, a mixer, an extruder, a kneader (prebreaker), etc., and a dried modified diene rubber can be obtained.

  In the second method, the oxidized diene rubber latex is coagulated, ground and dried, and then the polar group-containing hydrazide compound is added. For example, a step of adding a polar group-containing hydrazide compound solution to a solid oxide diene rubber after drying by a mixer, an extruder, a kneader, etc. is preferable. It is preferable to do.

  In the third method, the polar group-containing hydrazide compound is added to the oxidized diene rubber latex to which water and an emulsifier as necessary are added, and the mixture is stirred and reacted at a predetermined temperature. When the polar group-containing hydrazide compound is added to the oxidized diene rubber latex, an emulsifier is added in advance to the oxidized diene rubber latex, or the polar group-containing hydrazide compound is emulsified and then added to the oxidized diene rubber latex. Add. An organic peroxide can also be added as needed. The emulsifier that can be used is not particularly limited, and examples thereof include nonionic surfactants such as polyoxyethylene lauryl ether. A modified diene rubber can be obtained by coagulating and drying the modified diene rubber latex obtained by adding the polar group-containing hydrazide compound and reacting in this manner.

  In the three methods described above, the coagulant used for coagulating the oxidized diene rubber latex or the modified diene rubber latex is not particularly limited, but is not limited to acids such as formic acid and sulfuric acid, and sodium chloride. And the like. The oxidized diene rubber latex or the modified diene rubber latex can be dried using a dryer such as a vacuum dryer, an air dryer or a drum dryer.

（式中、Ｒ^Iは、置換基としてアミノ基、イミノ基、ニトリル基、アンモニウム基、イミド基、アミド基、ヒドラゾ基、アゾ基、ジアゾ基、ヒドロキシル基、カルボキシル基、カルボニル基、エポキシ基、オキシカルボニル基、スズ含有基、アルコキシシリル基からなる群から選ばれる極性基を少なくとも１種有する炭素数１〜４のアルキレン基、置換基として該極性基を少なくとも１種有するフェニレン基、又は含窒素複素環基及び含酸素複素環基からなる群から選ばれる少なくとも１種の極性基である）で表される極性基含有官能基を有する。なお、上記一般式（I）中のＲ^Iは上述したような極性基含有ヒドラジド化合物のヒドラジド基以外の部分に由来するものである。 The modified diene rubber obtained as described above has the following general formula (I) at the end of the molecular chain of the diene rubber:

(In the formula, R ^I is an amino group, imino group, nitrile group, ammonium group, imide group, amide group, hydrazo group, azo group, diazo group, hydroxyl group, carboxyl group, carbonyl group, epoxy group, An alkylene group having 1 to 4 carbon atoms having at least one polar group selected from the group consisting of an oxycarbonyl group, a tin-containing group and an alkoxysilyl group, a phenylene group having at least one polar group as a substituent, or nitrogen-containing A polar group-containing functional group represented by at least one polar group selected from the group consisting of a heterocyclic group and an oxygen-containing heterocyclic group. In addition, R ^I in the general formula (I) is derived from a portion other than the hydrazide group of the polar group-containing hydrazide compound as described above.

  In addition, when the modified diene rubber is blended with a filler such as carbon black or silica, considering the purpose of improving low loss characteristics and wear resistance without degrading workability, each of the diene rubbers Since it is important that even a small amount of polar groups be introduced into the molecule, the addition amount of the polar group-containing hydrazide compound in the modified diene rubber is 0.01 to 5 with respect to the rubber component in the diene rubber latex. 0.0 mass% is preferable, and 0.01 to 1.0 mass% is more preferable.

  Further, the modified diene rubber has a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography of 200,000 or more from the viewpoint of ensuring excellent low loss, wear resistance and breaking strength as a rubber composition. And more preferably 400,000 or more.

In the rubber composition used in the tire of the present invention, the high molecular weight modified conjugated diene polymer has a weight average molecular weight of more than 15 × 10 ⁴ and not more than 200 × 10 ⁴ before modification, and a low molecular weight modified conjugated diene polymer. Has a weight average molecular weight of 2 × 10 ³ to 15 × 10 ⁴ before modification. Here, to limit the weight average molecular weight prior to modification of high molecular weight modified conjugated diene polymer 15 × 10 ⁴ to exceed 200 × 10 ⁴ or less, the wear resistance and fracture If it is 15 × 10 ⁴ or less This is because the properties deteriorate, and when it exceeds 200 × 10 ⁴ , the workability of the rubber composition is lowered. From these viewpoints, the weight average molecular weight of the high molecular weight modified conjugated diene polymer before modification is preferably 20 × 10 ^{4 to} 150 × 10 ⁴ , and more preferably 20 × 10 ^{4 to} 120 × 10 ^4. . On the other hand, the weight average molecular weight before modification of the low molecular weight modified conjugated diene polymer is limited to 2 × 10 ³ to 15 × 10 ⁴ , when it is less than 2 × 10 ³ , the dynamic shear storage modulus at high temperature. This is because G ′ decreases and dynamic loss tangent tan δ increases, and if it exceeds 15 × 10 ⁴ , workability decreases. From these viewpoints, the weight average molecular weight of the low molecular weight modified conjugated diene polymer before modification is preferably 5 × 10 ^{3 to} 12 × 10 ⁴ . The weight average molecular weight before modification is the weight average molecular weight before the polymerization active site of the polymer is modified with a modifier.

  In the rubber composition used in the tire of the present invention, the amount of the low molecular weight conjugated diene polymer is 5 to 50 parts by mass with respect to 100 parts by mass of the rubber matrix. Here, the amount of the low molecular weight modified conjugated diene polymer is limited to 5 to 50 parts by mass because the on-ice performance and wet performance of the tire cannot be improved if the amount is less than 5 parts by mass, and 50 parts by mass. This is because the wear resistance and fracture resistance are deteriorated when the amount exceeds. From these viewpoints, the blending amount of the low molecular weight modified conjugated diene polymer is preferably 5 to 40 parts by mass, more preferably 5 to 30 parts by mass with respect to 100 parts by mass of the rubber matrix.

  In the rubber composition, the combined aromatic vinyl content (X) (% by mass) of the low molecular weight modified conjugated diene polymer and the vinyl bond content (Y) (%) of the conjugated diene are X + (Y / 2) It is preferable to satisfy <25. If {X + (Y / 2)} is less than 25, the performance on ice is improved.

  In the rubber composition, the low molecular weight modified conjugated diene polymer preferably contains at least one functional group selected from the group consisting of a tin-containing functional group, a silicon-containing functional group, and a nitrogen-containing functional group. . The high molecular weight modified conjugated diene polymer preferably contains at least one functional group selected from the group consisting of a tin-containing functional group, a silicon-containing functional group, and a nitrogen-containing functional group. This is because these functional groups are rich in reactivity with the reinforcing filler and improve the reinforcing property of the rubber composition. In particular, a tin-containing functional group is preferable because it is highly reactive with carbon black, a silicon-containing functional group is preferable because it is highly reactive with silica, and a nitrogen-containing functional group is highly reactive with both carbon black and silica. Therefore, it is preferable. As will be described later, the nitrogen-containing functional group may contain a silicon atom, and the silicon-containing functional group may contain a nitrogen atom.

  Here, examples of the tin-containing functional group include a tin halide compound residue, such as triphenyl tin chloride, tributyl tin chloride, triisopropyl tin chloride, trihexyl tin chloride, trioctyl tin chloride, diphenyl tin dichloride, dibutyl tin dichloride. Residue formed by leaving one or more chlorine atoms from a tin chloride compound selected from the group consisting of dihexyltin dichloride, dioctyltin dichloride, phenyltin trichloride, butyltin trichloride, octyltin trichloride and tin tetrachloride Is preferred.

  Moreover, as a silicon-containing functional group, a dialkoxysilane compound residue or a trialkoxysilane compound residue is preferable. Here, the two alkoxy groups of the dialkoxysilane compound are each independently an alkoxy group having 1 to 20 carbon atoms which may have a substituent. Similarly, the three alkoxy groups of the trialkoxysilane compound are each independently an alkoxy group having 1 to 20 carbon atoms which may have a substituent. Furthermore, the functional group containing a silicon atom preferably has an amino group, more preferably a primary amino group.

式（１'）中、Ａは、イソシアネート基、チオイソシアネート基、イミン残基、アミド基、第一アミノ基、第一アミンのオニウム塩残基，環状第二アミノ基、環状第二アミンのオニウム塩残基、非環状第二アミノ基及び非環状第二アミンのオニウム塩残基、イソシアヌル酸トリエステル残基、環状第三アミノ基、非環状第三アミノ基、ニトリル基、ピリジン残基、環状第三アミンのオニウム塩残基、非環状第三アミンのオニウム塩残基、エポキシ基、チオエポキシ基、ケトン基、チオケトン基、アルデヒド基、チオアルデヒド基、カルボン酸エステル残基、チオカルボン酸エステル残基、カルボン酸無水物残基、カルボン酸ハロゲン化物残基、炭酸ジヒドロカルビルエステル残基、スルフィド基、ポリスルフィド基、ヒドロキシ基、チオール基、アリル又はベンジルとＳｎとの結合を有する基、スルフォニル基及びスルフィニル基から選ばれる少なくとも一種の官能基を有する一価の基、Ｒ²¹は単結合又は二価の不活性炭化水素基、Ｒ²²及びＲ²³は、それぞれ独立に炭素数１〜２０の一価の脂肪族炭化水素基又は炭素数６〜１８の一価の芳香族炭化水素基を示し、ｍは０〜２の整数であり、ＯＲ²³が複数ある場合、複数のＯＲ²³は同一でも異なっていてもよい。上記の内、第一アミノ基は変性反応終了後までアルキルシリル基（例えば、メチルシリル基やエチルシリル基）等により保護されていることが好ましい。 Furthermore, examples of the silicon-containing functional group include a residue formed by leaving one or more of —OR ^{23 of the} hydrocarbyloxysilane compound represented by the following general formula (1 ′) and its partial condensate. .

In the formula (1 ′), A is an isocyanate group, a thioisocyanate group, an imine residue, an amide group, a primary amino group, an onium salt residue of a primary amine, a cyclic secondary amino group, an onium of a cyclic secondary amine Salt residue, acyclic secondary amino group and onium salt residue of acyclic secondary amine, isocyanuric acid triester residue, cyclic tertiary amino group, acyclic tertiary amino group, nitrile group, pyridine residue, cyclic Tertiary amine onium salt residue, acyclic tertiary amine onium salt residue, epoxy group, thioepoxy group, ketone group, thioketone group, aldehyde group, thioaldehyde group, carboxylic acid ester residue, thiocarboxylic acid ester residue Carboxylic acid anhydride residue, carboxylic acid halide residue, carbonic acid dihydrocarbyl ester residue, sulfide group, polysulfide group, hydroxy group, thiol group , A group having a bond between allyl or benzyl and Sn, a monovalent group having at least one functional group selected from a sulfonyl group and a sulfinyl group, R ²¹ is a single bond or a divalent inert hydrocarbon group, R ²² And R ²³ each independently represents a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, m is an integer of 0 to 2, If OR ²³ there are a plurality, the plurality of OR ²³ may be the same or different. Of the above, the primary amino group is preferably protected by an alkylsilyl group (for example, a methylsilyl group or an ethylsilyl group) or the like until after the modification reaction.

As the divalent inert hydrocarbon group in R ²¹ , an alkylene group having 1 to 20 carbon atoms can be preferably exemplified. The alkylene group may be linear, branched, or cyclic, but a linear one is particularly preferable. Examples of the linear alkylene group include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, an octamethylene group, a decamethylene group, and a dodecamethylene group.

Examples of R ²² and R ²³ include an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, and an aralkyl group having 7 to 18 carbon atoms. Here, the alkyl group and alkenyl group may be linear, branched, or cyclic, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, Isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, decyl, dodecyl, cyclopentyl, cyclohexyl, vinyl, propenyl, allyl, hexenyl, octenyl, cyclo A pentenyl group, a cyclohexenyl group, etc. are mentioned. The aryl group may have a substituent such as a lower alkyl group on the aromatic ring, and examples thereof include a phenyl group, a tolyl group, a xylyl group, and a naphthyl group. Furthermore, the aralkyl group may have a substituent such as a lower alkyl group on the aromatic ring, and examples thereof include a benzyl group, a phenethyl group, and a naphthylmethyl group.

As the nitrogen-containing functional group, among the residues formed by leaving one or more of —OR ^{23 of the} hydrocarbyloxysilane compound represented by the above general formula (1 ′) and its partial condensate, A is an isocyanate. Groups, thioisocyanate groups, imine residues, amide groups, primary amino groups, primary amine onium salt residues, cyclic secondary amino groups, cyclic secondary amine onium salt residues, acyclic secondary amino groups and Acyclic secondary amine onium salt residue, isocyanuric acid triester residue, cyclic tertiary amino group, acyclic tertiary amino group, nitrile group, pyridine residue, cyclic tertiary amine onium salt residue, acyclic Examples thereof include a nitrogen-containing hydrocarbyloxysilane compound residue that is an onium salt residue of a tertiary amine. The nitrogen-containing functional group preferably has an amino group, more preferably a primary amino group.

  Of the nitrogen-containing hydrocarbyloxysilane compounds represented by the general formula (1 ′), N- (1,3-dimethylbutylidene) -3- (triethoxysilyl) -1 is used as the imine residue-containing hydrocarbyloxycyan compound. -Propanamine, N- (1-methylethylidene) -3- (triethoxysilyl) -1-propanamine, N-ethylidene-3- (triethoxysilyl) -1-propanamine, N- (1-methylpropyl) Ridene) -3- (triethoxysilyl) -1-propanamine, N- (4-N, N-dimethylaminobenzylidene) -3- (triethoxysilyl) -1-propanamine, N- (cyclohexylidene) -3- (Triethoxysilyl) -1-propanamine and trimethoxysilyl corresponding to these triethoxysilyl compounds Preferred examples thereof include a methyl compound, a methyldiethoxysilyl compound, an ethyldiethoxysilyl compound, a methyldimethoxysilyl compound, and an ethyldimethoxysilyl compound. Among these, N- (1-methylpropylidene) -3- (Triethoxysilyl) -1-propanamine and N- (1,3-dimethylbutylidene) -3- (triethoxysilyl) -1-propanamine are preferred.

  Other imine residue (amidine group) -containing compounds include 1- [3- (triethoxysilyl) propyl] -4,5-dihydroimidazole, 1- [3- (trimethoxysilyl) propyl] -4. , 5-dihydroimidazole, 3- [10- (triethoxysilyl) decyl] -4-oxazoline and the like. Among these, 3- (1-hexamethyleneimino) propyl (triethoxy) silane, ( 1-hexamethyleneimino) methyl (trimethoxy) silane, 1- [3- (triethoxysilyl) propyl] -4,5-dihydroimidazole and 1- [3- (trimethoxysilyl) propyl] -4,5-dihydro Preference is given to imidazole. N- (3-triethoxysilylpropyl) -4,5-dihydroimidazole, N- (3-isopropoxysilylpropyl) -4,5-dihydroimidazole, N- (3-methyldiethoxysilylpropyl)- 4,5-dihydroimidazole and the like can be mentioned, and among these, N- (3-triethoxysilylpropyl) -4,5-dihydroimidazole is preferable.

  Among the nitrogen-containing hydrocarbyloxysilane compounds represented by the general formula (1 ′), the isocyanate group-containing compounds include 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, and 3-isocyanato. Examples thereof include propylmethyldiethoxysilane and 3-isocyanatopropyltriisopropoxysilane. Among these, 3-isocyanatopropyltriethoxysilane is preferable.

  Among the nitrogen-containing hydrocarbyloxysilane compounds represented by the general formula (1 ′), examples of the cyclic tertiary amino group-containing compound include 3- (1-hexamethyleneimino) propyl (triethoxy) silane, 3- (1-hexa Methyleneimino) propyl (trimethoxy) silane, (1-hexamethyleneimino) methyl (trimethoxy) silane, (1-hexamethyleneimino) methyl (triethoxy) silane, 2- (1-hexamethyleneimino) ethyl (triethoxy) silane, 2- (1-hexamethyleneimino) ethyl (trimethoxy) silane, 3- (1-pyrrolidinyl) propyl (triethoxy) silane, 3- (1-pyrrolidinyl) propyl (trimethoxy) silane, 3- (1-heptamethyleneimino) Propyl (triethoxy) silane, 3- (1-do Preferred examples include decamethyleneimino) propyl (triethoxy) silane, 3- (1-hexamethyleneimino) propyl (diethoxy) methylsilane, and 3- (1-hexamethyleneimino) propyl (diethoxy) ethylsilane. Particularly preferred are 3- (1-hexamethyleneimino) propyl (triethoxy) silane and (1-hexamethyleneimino) methyl (trimethoxy) silane. Furthermore, examples of other hydrocarbyloxysilane compounds include 2- (trimethoxysilylethyl) pyridine, 2- (triethoxysilylethyl) pyridine, 4-ethylpyridine and the like.

  Among the nitrogen-containing hydrocarbyloxysilane compounds represented by the general formula (1 ′), 3-dimethylaminopropyl (triethoxy) silane, 3-dimethylaminopropyl (trimethoxy) are used as the acyclic tertiary amino group-containing hydrocarbyloxysilane compounds. Silane, 3-diethylaminopropyl (triethoxy) silane, 3-diethylaminopropyl (trimethoxy) silane, 2-dimethylaminoethyl (triethoxy) silane, 2-dimethylaminoethyl (trimethoxy) silane, 3-dimethylaminopropyl (diethoxy) methylsilane, Examples include 3-dibutylaminopropyl (triethoxy) silane, among which 3-diethylaminopropyl (triethoxy) silane and 3-dimethylaminopropyl (trieth). Xyl) silane is preferred. Further, examples of the nitrogen-containing hydrocarbyloxysilane compound represented by the general formula (1 ′) include 2- (trimethoxysilylethyl) pyridine, 2- (triethoxysilylethyl) pyridine, 2-cyanoethyltriethoxysilane, and the like. Can be mentioned.

式（２'）中、Ｒ²⁴及びＲ²⁶は夫々独立に−ＯＲ、−ＯＨ又は炭素数１〜２０のアルキル基であり、Ｒ²⁵は炭素数１〜２０のアルキレン基であり、Ｒは硫黄原子、酸素原子、窒素原子及び／又はハロゲン原子を有していても良い炭素数１〜２０のヒドロカルビル基である。

式（３'）中、Ｒ²⁷及びＲ²⁹は夫々独立に−ＯＲ、−ＯＨ又は炭素数１〜２０のアルキル基であり、Ｒ²⁸及びＲ³⁰は夫々独立に炭素数１〜２０のアルキレン基であり、Ｒは硫黄原子、酸素原子、窒素原子及び／又はハロゲン原子を有していても良い炭素数１〜２０のヒドロカルビル基であり、ＭはＳｉ、Ｔｉ、Ｓｎ、Ｂｉ、Ｚｒ又はＡｌであり、Ｒ³¹は−ＯＨ、炭素数１〜３０のヒドロカルビル基、炭素数２〜３０のヒドロカルビルカルボキシル基、炭素数５〜２０の１，３−ジカルボニル含有基、炭素数１〜２０のヒドロカルビルオキシ基、並びに炭素数１〜２０のヒドロカルビル基及び／又は炭素数１〜２０のヒドロカルビルオキシ基で三置換されたシロキシ基からなる群から選ばれる基であり、複数のＲ³¹は同一でも異なっていても良く、ｋは｛（Ｍの価数）−２｝であり、ｎは０又は１の整数である］ As the nitrogen-containing functional group, among the residues formed by leaving one or more of —OR ^{23 of the} hydrocarbyloxysilane compound represented by the above general formula (1 ′) and its partial condensate, the following general formula A monovalent functional group represented by (2 ′) or a divalent functional group represented by the following general formula (3 ′) is particularly preferred. This is because the primary amino group of the general formula (2 ′) or the general formula (3 ′) particularly improves the reinforcing properties of both carbon black and silica.

In the formula (2 ′), R ²⁴ and R ²⁶ are each independently —OR, —OH or an alkyl group having 1 to 20 carbon atoms, R ²⁵ is an alkylene group having 1 to 20 carbon atoms, and R is sulfur. It is a C1-C20 hydrocarbyl group which may have an atom, an oxygen atom, a nitrogen atom and / or a halogen atom.

In the formula (3 ′), R ²⁷ and R ²⁹ are each independently —OR, —OH or an alkyl group having 1 to 20 carbon atoms, and R ²⁸ and R ³⁰ are each independently an alkylene group having 1 to 20 carbon atoms. R is a C 1-20 hydrocarbyl group optionally having a sulfur atom, oxygen atom, nitrogen atom and / or halogen atom, and M is Si, Ti, Sn, Bi, Zr or Al. R ³¹ is —OH, a hydrocarbyl group having 1 to 30 carbon atoms, a hydrocarbyl carboxyl group having 2 to 30 carbon atoms, a 1,3-dicarbonyl-containing group having 5 to 20 carbon atoms, and a hydrocarbyloxy group having 1 to 20 carbon atoms. A group selected from the group consisting of a group and a siloxy group trisubstituted with a hydrocarbyl group having 1 to 20 carbon atoms and / or a hydrocarbyloxy group having 1 to 20 carbon atoms, and a plurality of R ³¹ may be the same or different. Well , K is {(valence of M) −2}, and n is an integer of 0 or 1]

As —OR of R ²⁴ , R ²⁶ , R ²⁷ and R ^{29 in} the above general formulas (2 ′) and (3 ′), methoxy group, ethoxy group, propoxy group, isopropoxy group, n-butoxy group, isobutoxy group , Sec-butoxy group, tert-butoxy group, pentyloxy group, allyloxy group, phenoxy group, benzyloxy group, etc. These functional groups have a sulfur atom, oxygen atom, nitrogen atom and / or halogen atom. You may do it. The sulfur atom may be contained in R as, for example, —SH, —S _X — (X is an integer of 1 to 5), or an epithio group. The oxygen atom may be contained in R as —OH, —O—, an epoxy group, an acyl group, or a carboxyl group. The nitrogen atom is an amino group (primary amino group, secondary amino group, or acyclic or cyclic tertiary amino group), imino group, amidine group, isocyanate group, N-hydroxy group, N-oxide group, nitrile group, It may be contained in R as an imine residue or a cyano group.

Examples of the alkyl group having 1 to 20 carbon atoms of R ²⁴ , R ²⁶ , R ²⁷ and R ²⁹ include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, Examples thereof include a tert-butyl group, a pentyl group, a hexyl group, and an octyl group. The halogen atom which may be contained in R may be any of fluorine, chlorine, bromine and iodine, but chlorine or bromine is preferred.

Examples of the alkylene group having 1 to 20 carbon atoms of R ²⁵ , R ²⁸ and R ^{30 in} the general formulas (2 ′) and (3 ′) include a methylene group, an ethylene group, a propane-1,3-diyl group, and propane- 1,2-diyl group, butane-1,4-diyl group, butane-1,3-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl Group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group and the like.

R ^{31 in the} general formula (3 ′) is methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group. Groups and the like.
In general, R ²⁷ and R ²⁹ are the same, and R ²⁸ and R ³⁰ are the same. The divalent functional group represented by the general formula (3 ′) is usually formed by condensing two polymer chains having the same monovalent functional group represented by the general formula (2 ′). is there.
The primary amino group of the general formula (2 ′) or (3 ′) is an alkylsilyl group (for example, a methylsilyl group or an ethylsilyl group) until after the modification reaction, as in the case of the general formula (1 ′). It is preferable that it is protected by the above.

  A residue from which lithium is released from a lithium amide compound described later as an initiator for anionic polymerization is also preferable as the nitrogen-containing functional group contained in the high molecular weight modified conjugated diene polymer or the low molecular weight modified conjugated diene polymer.

  The at least one functional group selected from the group consisting of a tin-containing functional group, a silicon-containing functional group, and a nitrogen-containing functional group contained in the high molecular weight modified conjugated diene polymer is the above general formula (2 ′). Or a divalent functional group represented by the general formula (3 ′) is preferred. On the other hand, among the at least one functional group selected from the group consisting of a tin-containing functional group, a silicon-containing functional group and a nitrogen-containing functional group contained in the low molecular weight modified conjugated diene polymer, the above general formula (2 ′) Or a functional group other than the divalent functional group represented by the general formula (3 ′). Since the monovalent functional group represented by the general formula (2 ′) or the divalent functional group represented by the general formula (3 ′) has high reactivity with the reinforcing filler, the modified conjugated diene polymer This is because the rubber composition further improves the reinforcing property due to the reaction between the reinforcing filler and the reinforcing filler, and further improves the dry steering stability performance, wear resistance and fracture resistance.

  In the rubber composition, the low molecular weight modified conjugated diene polymer is preferably modified polybutadiene and / or modified polyisoprene, and particularly preferably modified polybutadiene. On the other hand, the high molecular weight modified conjugated diene polymer is preferably modified polybutadiene rubber and / or modified polyisoprene rubber, and particularly preferably modified polybutadiene rubber. This is because the glass transition point (Tg) of the low molecular weight modified conjugated diene polymer and the high molecular weight modified conjugated diene polymer is lowered to improve the performance on ice.

In the rubber composition, the low molecular weight modified conjugated diene polymer and / or the high molecular weight modified conjugated diene polymer is particularly preferably represented by the general formula (1) or the general formula (2). . In the above general formulas (1) and (2),-(Polymer) is a polymer chain of a conjugated diene polymer. Usually, R ⁴ and R ⁶ are the same, and R ⁵ and R ⁷ are the same. This is because the two polymer chains to be condensed are usually the same.

In the general formulas (1) and (2), R ¹ , R ³ , R ^4, and R ⁶ —OR include methoxy group, ethoxy group, propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, sec -Butoxy group, tert-butoxy group, pentyloxy group, allyloxy group, phenoxy group, benzyloxy group and the like, and these functional groups have a sulfur atom, an oxygen atom, a nitrogen atom and / or a halogen atom. May be. The sulfur atom may be contained in R as, for example, —SH, —S _X — (X is an integer of 1 to 5), or an epithio group. The oxygen atom may be contained in R as —OH, —O—, an epoxy group, an acyl group, or a carboxyl group. The nitrogen atom is an amino group (primary amino group, secondary amino group, or acyclic or cyclic tertiary amino group), imino group, imine residue, amidine group, isocyanate group, N-hydroxy group, N-oxide group. And may be contained in R as a cyano group.

The alkyl group of R ^1, R ^3, R ⁴ and carbon atoms R ⁶ 1 to 20, a methyl group, an ethyl group, a propyl group, an isopropyl group, n- butyl group, isobutyl group, sec- butyl group, Examples thereof include a tert-butyl group, a pentyl group, a hexyl group, and an octyl group. The halogen atom which may be contained in R may be any of fluorine, chlorine, bromine and iodine, but chlorine or bromine is preferred.

Examples of the alkylene group having 1 to 20 carbon atoms of R ² , R ⁵ and R ^{7 in} the general formulas (1) and (2) include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1, 2-diyl group, butane-1,4-diyl group, butane-1,3-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, Examples include octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group and the like. In addition, as R ^{8 in the} general formula (2), methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, An octyl group etc. are mentioned.

  Examples of the conjugated diene monomer used in the low molecular weight modified conjugated diene polymer and the high molecular weight modified conjugated diene polymer include 1,3-butadiene, isoprene, 1,3-pentadiene, and 2,3-dimethyl-1. , 3-butadiene, 2-phenyl-1,3-butadiene, 1,3-hexadiene and the like. These may be used alone or in combination of two or more, and among these, 1,3-butadiene is particularly preferable. Examples of the aromatic vinyl monomer used in the low molecular weight modified conjugated diene polymer and the high molecular weight modified conjugated diene polymer include styrene, α-methylstyrene, 1-vinylnaphthalene, 3-vinyltoluene, and ethyl. Examples include vinylbenzene, divinylbenzene, 4-cyclohexylstyrene, 2,4,6-trimethylstyrene, and the like. These may be used alone or in combination of two or more, but among these, styrene is particularly preferred.

  A polymerization reaction system for obtaining a low molecular weight modified conjugated diene polymer and a high molecular weight modified conjugated diene polymer used in the rubber composition will be described. In order to react the active end of the conjugated diene polymer with the modifier and introduce a tin-containing functional group, silicon-containing functional group or nitrogen-containing functional group at the active end of the conjugated diene polymer, The coalescence is preferably such that at least 10% of the polymer chains have living or pseudo-living properties. Examples of such a polymerization reaction having a living property include anionic polymerization and coordination anionic polymerization. Anionic polymerization is preferable in that a wide range of modification is possible.

  As the alkali metal compound used as the initiator for the anionic polymerization described above, a lithium compound is preferable. The lithium compound is not particularly limited, but hydrocarbyl lithium and lithium amide compounds are preferably used. When the former hydrocarbyl lithium is used, it has a hydrocarbyl group at the polymerization initiation terminal and the other terminal is a polymerization active site. A conjugated diene polymer is obtained. When the latter lithium amide compound is used, a conjugated diene polymer having a nitrogen-containing group at the polymerization initiation terminal and the other terminal being a polymerization active site is obtained. That is, when a lithium amide compound is used as an anionic polymerization initiator, the resulting low molecular weight modified conjugated diene polymer or high molecular weight modified conjugated diene polymer has a CN bond at the polymerization initiation terminal of the polymer. become.

  As the hydrocarbyl lithium, those having a hydrocarbyl group having 2 to 20 carbon atoms are preferable, for example, ethyl lithium, n-propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, tert-octyl lithium, n-decyl. Examples include lithium, phenyllithium, 2-naphthyllithium, 2-butylphenyllithium, 4-phenylbutyllithium, cyclohexyllithium, cyclobenthyllithium, and reactive organisms of diisopropenylbenzene and butyllithium. Of these, n-butyllithium is particularly preferred.

  On the other hand, examples of the lithium amide compound include lithium hexamethylene imide, lithium pyrrolidide, lithium piperide, lithium heptamethylene imide, lithium dodecamethylene imide, lithium dimethyl amide, lithium diethyl amide, lithium dibutyl amide, lithium dipropyl amide, and lithium disulfide. Heptylamide, lithium dihexylamide, lithium dioctylamide, lithium di-2-ethylhexylamide, lithium didecylamide, lithium-N-methylpiverazide, lithium ethylpropylamide, lithium ethylbutyramide, lithium ethylbenzylamide, lithium methylphenethylamide, etc. Is mentioned. Among these, from the viewpoint of the interaction effect on carbon black and the ability of initiating polymerization, cyclic lithium amides such as lithium hexamethylene imide, lithium pyrrolidide, lithium piperidide, lithium heptamethylene imide, and lithium dodecamethylene imide are preferable. In particular, lithium hexamethylene imide and lithium pyrrolidide are suitable.

  In general, these lithium amide compounds prepared in advance from a secondary amine and a lithium compound can be used for polymerization, but they can also be prepared in-situ. The amount of the polymerization initiator used is preferably selected in the range of 0.2 to 20 mmol per 100 g of monomer.

  There is no restriction | limiting in particular as a method of manufacturing a conjugated diene polymer by anionic polymerization using the said lithium compound as a polymerization initiator, A conventionally well-known method can be used. Specifically, in an organic solvent inert to the reaction, for example, a hydrocarbon solvent such as an aliphatic, alicyclic, or aromatic hydrocarbon compound, a conjugated diene monomer or a conjugated diene monomer and an aromatic vinyl are used. By subjecting the monomer to anionic polymerization in the presence of a randomizer to be used, if desired, using the above lithium compound as a polymerization initiator, a conjugated diene polymer having the desired active terminal can be obtained. In addition, when a lithium compound is used as a polymerization initiator, not only a conjugated diene polymer having an active terminal but also a conjugated compound having an active terminal is used compared to the case of using a catalyst containing a lanthanum series rare earth element compound described later. A diene-aromatic vinyl copolymer can also be obtained efficiently.

  The hydrocarbon solvent is preferably one having 3 to 8 carbon atoms, such as propane, n-butane, isobutane, n-pentane, isopentane, n-hexane, cyclohexane, propene, 1-butene, isobutene and trans-2. -Butene, cis-2-butene, 1-pentene, 2-pentene, 1-hexene, 2-hexene, benzene, toluene, xylene, ethylbenzene and the like. These may be used alone or in combination of two or more. The monomer concentration in the solvent is preferably 5 to 50% by mass, more preferably 10 to 30% by mass. When copolymerization is performed using a conjugated diene monomer and an aromatic vinyl monomer, the content of the aromatic vinyl monomer in the charged monomer mixture is preferably in the range of 55% by mass or less.

  The randomizer used as desired is the control of the microstructure of the conjugated diene polymer, such as the vinyl bond in the butadiene polymer, the vinyl bond in the butadiene moiety in the butadiene-styrene copolymer, and the increase in the vinyl bond in the isoprene polymer. Or a compound having an action of controlling the composition distribution of monomer units in a conjugated diene-aromatic vinyl copolymer, for example, randomizing butadiene units or styrene units in a butadiene-styrene copolymer. The randomizer is not particularly limited, and any one of known compounds generally used as a conventional randomizer can be appropriately selected and used.

  Specific examples of the randomizer include dimethoxybenzene, tetrahydrofuran, dimethoxyethane, diethylene glycol dibutyl ether, diethylene glycol dimethyl ether, oxolanyl propane oligomers [especially those containing 2,2-bis (2-tetrahydrofuryl) -propane, etc.], Examples thereof include ethers such as triethylamine, pyridine, N-methylmorpholine, N, N, N ′, N′-tetramethylethylenediamine and 1,2-dipiperidinoethane, and tertiary amines. Further, potassium salts such as potassium t-amylate and potassium t-butoxide, and sodium salts such as sodium t-amylate can also be used.

  One of these randomizers may be used alone, or two or more thereof may be used in combination. The amount used is preferably selected in the range of 0.01 to 1000 molar equivalents per mole of the lithium compound.

  The temperature in this polymerization reaction is preferably selected in the range of 0 to 150 ° C, more preferably 20 to 130 ° C. The polymerization reaction can be carried out under generated pressure, but it is usually desirable to operate at a pressure sufficient to keep the monomer in a substantially liquid phase. That is, the pressure depends on the particular material being polymerized, the polymerization medium used and the polymerization temperature, but higher pressures can be used if desired, such pressure being a gas that is inert with respect to the polymerization reaction. Can be obtained by an appropriate method such as pressurizing.

  In the above-mentioned anionic polymerization, all raw materials involved in the polymerization such as polymerization initiator, solvent, monomer, etc. should be used after removing reaction inhibitor such as water, oxygen, carbon dioxide, and protic compound. desirable. The polymerization reaction may be carried out either batchwise or continuously. In this way, a conjugated diene polymer having an active end is obtained.

  In the present invention, the conjugated diene polymer having an active terminal obtained as described above is incorporated with the above-described modifier capable of introducing a tin-containing functional group, a silicon-containing functional group and a nitrogen-containing functional group. The stoichiometric amount or an excess thereof is preferably added to the active end of the diene polymer and reacted with the active end of the polymer. The modification reaction may be performed under the same temperature and pressure conditions as the polymerization reaction.

  The amount of the above-mentioned modifier used is usually 0.2 to 10 equivalents, preferably 0.5 to 5.0 equivalents, based on a functional group capable of undergoing a modification reaction, per 1 g atomic equivalent of lithium atom. If the amount is less than 2 equivalents, the rebound resilience and low heat build-up effect of the vulcanized rubber is inferior. On the other hand, if the amount exceeds 10 equivalents, unreacted substances increase and odor is generated, the vulcanization speed is increased, The effects of rebound resilience and low heat build-up are reduced, which is not preferable.

  Next, as the modifier capable of introducing the divalent functional group represented by the general formula (3 ′), the hydrocarbyloxysilane compound having the protected primary amino group described above is preferably used. After performing the first-stage modification reaction with a modifier, it is necessary to perform the second-stage modification reaction in the presence of a combination of a condensation accelerator composed of a metal compound of Si, Ti, Sn, Bi, Zr or Al and water. is there.

  Examples of the hydrocarbyloxysilane compound having a protected primary amino group include N, N-bis (trimethylsilyl) aminopropylmethyldimethoxysilane, 1-trimethylsilyl-2,2-dimethoxy-1-aza-2-silacyclo. Pentane, N, N-bis (trimethylsilyl) aminopropyltrimethoxysilane, N, N-bis (trimethylsilyl) aminopropyltriethoxysilane, N, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane, N, N-bis (Trimethylsilyl) aminoethyltrimethoxysilane, N, N-bis (trimethylsilyl) aminoethyltriethoxysilane, N, N-bis (trimethylsilyl) aminoethylmethyldimethoxysilane or N, N-bis (trimethylsilyl) aminoethylmethyldie And the like can be preferably exemplified Kishishiran. Particularly preferably, N, N-bis (trimethylsilyl) aminopropylmethyldimethoxysilane, N, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane or 1-trimethylsilyl-2,2-dimethoxy-1-aza-2-sila Mention may be made of cyclopentane. One of these hydrocarbyloxysilane compounds may be used alone, or two or more thereof may be used in combination.

Among the condensation accelerators, the metal compound includes a divalent tin compound represented by the following general formula (3), a tetravalent tin compound represented by the following general formula (4), and the following general formula (5). The titanium compound represented by these is preferable.
Sn (OCOR ⁹ ) ₂ (3)
Here, R ⁹ is an alkyl group having 2 to 19 carbon atoms.
R ¹⁰ _x SnA ¹ _y B ¹ _4-yx (4)
Here, R ¹⁰ is an aliphatic hydrocarbon group having 1 to 30 carbon atoms, x is an integer of 1 to 3, y is 1 or 2, A ¹ is a hydrocarbyl carboxyl group having 2 to 30 carbon atoms, and 5 to 20 carbon atoms. Selected from a 1,3-dicarbonyl-containing group, a C 3-20 hydrocarbyloxy group, and a C 1-20 hydrocarbyl group and / or a siloxy group trisubstituted with a C 1-20 hydrocarbyloxy group. Group B ¹ is a hydroxy group or halogen.
A ² _z TiB ² _4-z (5)
Here, A ² is a group selected from an alkoxy group having 3 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms and / or a siloxy group trisubstituted with an alkoxy group having 1 to 20 carbon atoms, and B ² is carbon. 1,3-dicarbonyl-containing group of formula 5-20, z is 2 or 4.

  Further, as the above condensation accelerator, more specifically, divalent tin dicarboxylic acid {particularly, bis (hydrocarbylcarboxylic acid) salt} or tetravalent dihydrocarbyltin dicarboxylate {bis (hydrocarbylcarboxylic acid). ) Salt}, bis (β-diketonate), alkoxy halide, monocarboxylate hydroxide, alkoxy (trihydrocarbylsiloxide), alkoxy (dihydrocarbylalkoxysiloxide), bis (trihydrocarbylsiloxide), bis ( Dihydrocarbylalkoxysiloxide) and the like can be preferably used. The hydrocarbyl group bonded to tin preferably has 4 or more carbon atoms, and particularly preferably has 4 to 8 carbon atoms. Furthermore, examples of the titanium compound include tetravalent titanium tetraalkoxide, dialkoxybis (β-diketonate), tetrakis (trihydrocarboxide), and tetrakis (trihydrocarboxide) is particularly preferably used. .

  Examples of the bismuth compound include bismuth carboxylates {particularly hydrocarbyl carboxylates}, and examples of the zirconium compound include zirconium alkoxides and zirconium carboxylates {particularly hydrocarbyl carboxylates}. be able to. Examples of the aluminum compound include aluminum alkoxide and aluminum carboxylate {particularly hydrocarbyl carboxylate}. Examples of the silicon compound include silicon alkoxide and silicon carboxylate {particularly hydrocarbyl. Carboxylate}.

  Specific examples of the titanium compound include tetrakis (2-ethyl-1,3-hexanediolato) titanium, tetrakis (2-methyl-1,3-hexanediolato) titanium, tetrakis (2-propyl-1, 3-hexanediolato) titanium, tetrakis (2-butyl-1,3-hexanediolato) titanium, tetrakis (1,3-hexanediolato) titanium, tetrakis (1,3-pentanediolato) titanium, tetrakis ( 2-methyl-1,3-pentanediolato) titanium, tetrakis (2-ethyl-1,3-pentanediolato) titanium, tetrakis (2-propyl-1,3-pentanediolato) titanium, tetrakis (2- Butyl-1,3-pentanediolato) titanium, tetrakis (1,3-heptanediolato) titanium, tetrakis (2-methyl-) , 3-Heptanediolato) titanium, tetrakis (2-ethyl-1,3-heptanediolato) titanium, tetrakis (2-propyl-1,3-heptanediolato) titanium, tetrakis (2-butyl-1,3-heptanediolato) titanium, tetrakis (2-ethylhexoxy) titanium, tetramethoxy titanium, tetraethoxy titanium, tetra-n-propoxy titanium, tetraisopropoxy titanium, tetra-n-butoxy titanium, tetra-n-butoxy titanium oligomer, tetraisobutoxy titanium, tetra-sec -Butoxytitanium, tetra-tert-butoxytitanium, bis (oleate) bis (2-ethylhexanoate) titanium, titanium dipropoxybis (triethanolamate), titanium dibutoxybis (triethanolamate) , Titanium tributoxy systemate, titanium tripropoxy systemate, titanium tripropoxyacetylacetonate, titanium dipropoxybis (acetylacetonate), titanium tripropoxy (ethylacetoacetate), titaniumpropoxyacetylacetonatebis (ethylacetoacetate) , Titanium tributoxyacetylacetonate, titanium dibutoxybis (acetylacetonate), titanium tributoxyethylacetoacetate, titaniumbutoxyacetylacetonatebis (ethylacetoacetate), titanium tetrakis (acetylacetonate), titanium diacetylacetonatebis (Ethyl acetoacetate), bis (2-ethylhexanoate) titanium oxide, bis (laurate) titanium oxide, bis (naphth Tenate) titanium oxide, bis (stearate) titanium oxide, bis (oleate) titanium oxide, bis (linoleate) titanium oxide, tetrakis (2-ethylhexanoate) titanium, tetrakis (laurate) titanium, tetrakis (naphthenate) titanium, Tetrakis (stearate) titanium, Tetrakis (oleate) titanium, Tetrakis (linoleate) titanium, Titanium di-n-butoxide (bis-2,4-pentandionate), Titanium oxide bis (stearate), Titanium oxide bis (tetramethyl) Heptane dionate), titanium oxide bis (pentanedionate), titanium tetra (lactate) and the like. Among these, tetrakis (2-ethyl-1,3-hexanediolato) titanium, tetrakis (2-ethylhexoxy) titanium, and titanium di-n-butoxide (bis-2,4-pentanedionate) are preferable.

As the tin compound, specifically, stannous 2-ethylhexanoate {[CH ₃ (CH ₂ ) ₃ CH (C ₂ H ₅ ) CO ₂ ] ₂ Sn (divalent)}, stannous octoate Tin, stannous neodecanoate, stannous isooctanoate, stannous isodecanoate, 2,2-dimethyldecanoic acid, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dioctanoate, dimethyltin dilaurate, etc. . Specific examples of bismuth compounds include tris (2-ethylhexanoate) bismuth, tris (laurate) bismuth, tris (naphthenate) bismuth, tris (stearate) bismuth, tris (oleate) bismuth, tris (linoleate) bismuth. Etc.

  Specific examples of the zirconium compound include tetraethoxy zirconium, tetra n-propoxy zirconium, tetra i-propoxy zirconium, tetra n-butoxy zirconium, tetra sec-butoxy zirconium, tetra tert-butoxy zirconium, tetra (2-ethyl Xylyl) zirconium, zirconium tributoxy systemate, zirconium tributoxyacetylacetonate, zirconium dibutoxybis (acetylacetonate), zirconium tributoxyethylacetoacetate, zirconium butoxyacetylacetonatebis (ethylacetoacetate), zirconium tetrakis (acetyl) Acetonate), zirconium diacetylacetonate bis (ethyl acetoacetate), bis (2- Tylhexanoate) zirconium oxide, bis (laurate) zirconium oxide, bis (naphthenate) zirconium oxide, bis (stearate) zirconium oxide, bis (oleate) zirconium oxide, bis (linoleate) zirconium oxide, tetrakis (2-ethylhexa) Noate) zirconium, tetrakis (laurate) zirconium, tetrakis (naphthenate) zirconium, tetrakis (stearate) zirconium, tetrakis (oleate) zirconium, tetrakis (linoleate) zirconium and the like.

  Specific examples of the aluminum compound include triethoxyaluminum, tri-n-propoxyaluminum, tri-i-propoxyaluminum, tri-n-ptoxyaluminum, trisec-butoxyaluminum, tritert-butoxyaluminum, tri (2-ethyl). Hexyl) aluminum, aluminum dibutoxy systemate, aluminum dibutoxyacetylacetonate, aluminum butoxybis (acetylacetonate), aluminum dibutoxyethylacetoacetate, aluminum tris (acetylacetonate), aluminum tris (ethylacetoacetate), Tris (2-ethylhexanoate) aluminum, Tris (laurate) aluminum, Tris (naphthenate) aluminum, Tris (su Areto) aluminum, tris (oleate) aluminum, can be mentioned tris (linolate) aluminum and the like.

  Water is preferably used in the form of a solution such as a simple substance or alcohol, or a dispersed micelle in a hydrocarbon solvent, and if necessary, in the reaction system such as adsorbed water on the solid surface or hydrated water of hydrate. Water that is potentially contained in a compound capable of releasing water can also be used effectively. Accordingly, it is also preferable to use a compound that can easily release water, such as a solid having adsorbed water or a hydrate, in combination with the above condensation accelerator.

  The condensation accelerator and water may be added separately to the reaction system or mixed immediately before use as a mixture, but long-term storage of the mixture is not preferable because it causes decomposition of the metal compound. In addition, water may be charged into the reaction system as a solution of an organic solvent compatible with water such as alcohol, or water is directly injected and dispersed in the hydrocarbon solution using various chemical engineering techniques. You may let them. Water may be added by steam stripping or the like after completion of the second stage modification reaction. The amount of the condensation accelerator used is preferably selected so that the molar ratio of the metal and proton source of the metal compound to the total amount of hydrocarbyloxysilyl bonds present in the system is 0.1 or more. The number of moles of the condensation accelerator metal and water effective for the reaction is preferably 0.1 or more as a molar ratio to the total amount of hydrocarboxysilyl groups present in the reaction system. The upper limit depends on the purpose and reaction conditions, but there should be 0.5 to 3 molar equivalents of effective water based on the amount of hydrocarboxysilyl groups bound to the polymer active site before the condensation treatment. Is preferred. The second-stage modification reaction using the condensation accelerator is preferably performed at a temperature of 20 ° C. or higher, and more preferably in the range of 30 to 120 ° C. The reaction time is 0.5 minutes to 10 hours, preferably 0.5 minutes to 5 hours, more preferably about 0.5 to 120 minutes, and further preferably 3 to 60 minutes. In addition, the pressure of the reaction system at the time of the second stage modification reaction is usually 0.01 to 20 MPa, preferably 0.05 to 10 MPa.

  In the present invention, during this modification reaction, if desired, a known anti-aging agent or a short stop agent for the purpose of terminating the polymerization reaction, and a step after introducing a hydrocarbyloxysilane compound residue into the active site of the polymer. , Can be added. Further, after completion of the modification reaction, a condensation inhibitor such as a higher carboxylic acid ester of a polyhydric alcohol may be added to the reaction system. After the modification treatment in this way, a conventionally known post-treatment such as desolvation such as steam stripping can be performed to obtain the desired modified polymer.

  The deprotection treatment for removing the protected nitrogen atom protecting group after the completion of the two-stage denaturation reaction to produce a primary amino group is not limited to the above-mentioned desolvation treatment using steam such as steam stripping. Conversion from the stage of the modification reaction to the free primary amino group by hydrolyzing the protecting group on the primary amino group in various ways as required in any stage from solvent removal to dry polymer. The deprotection treatment of the protected primary amino group derived from the hydrocarbyloxysilane compound can be performed.

As an example, N, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane is used as the hydrocarbyloxysilane compound, and among the condensation accelerators, divalent Sn bis (hydrocarbylcarboxylic acid) salt is used as the metal compound. Then, by removing the protecting group of the nitrogen atom protected by steam stripping or the like after the completion of the two-stage modification reaction, a modified conjugated diene polymer having a primary amino group represented by the following formula (6) is obtained. It is done.

Next, a polymerization catalyst system for coordination anion polymerization will be described. As a polymerization catalyst system for coordination anionic polymerization, a catalyst containing a lanthanum series rare earth element compound in an organic solvent is used. As a catalyst containing a lanthanum series rare earth element compound,
(A) component: a rare earth element-containing compound having an atomic number of 57 to 71 in the periodic table, or a reaction product of these compounds with a Lewis base,
(B) component: The following general formula (7):
AlR ¹² R ¹³ R ¹⁴ (7)
(Wherein R ¹² and R ¹³ are the same or different and are a hydrocarbyl group having 1 to 10 carbon atoms or a hydrogen atom, and R ¹⁴ is a hydrocarbyl group having 1 to 10 carbon atoms, provided that R ¹⁴ is the above R ¹² or an organoaluminum compound represented by R ¹³ may be the same or different and), and component (C): at least one organic compound containing a Lewis acid, a metal halide, a complex compound of Lewis base, and an active halogen It is preferred to polymerize the conjugated diene monomer with a catalyst system comprising:

  In the present invention, in addition to the above components (A) to (C), an organoaluminum oxy compound, so-called aluminoxane is added as a component (D) in addition to the above components (A) to (C). preferable. Here, it is more preferable that the catalyst system is preliminarily prepared in the presence of the component (A), the component (B), the component (C), the component (D) and the conjugated diene monomer.

  In the present invention, the component (A) of the catalyst system containing a lanthanum series rare earth element compound is a compound containing a rare earth element having an atomic number of 57 to 71 in the periodic table, or a reaction product of these compounds with a Lewis base. . Here, among the rare earth elements having atomic numbers 57 to 71, neodymium, praseodymium, cerium, lanthanum, gadolinium, samarium, or a mixture thereof is preferable, and neodymium is particularly preferable.

  The rare earth element-containing compound is preferably a salt soluble in a hydrocarbon solvent, and specifically includes the rare earth element carboxylates, alkoxides, β-diketone complexes, phosphates and phosphites. Of these, carboxylates and phosphates are preferable, and carboxylates are particularly preferable. Here, examples of the hydrocarbon solvent include saturated aliphatic hydrocarbons having 4 to 10 carbon atoms such as butane, pentane, hexane and heptane, saturated alicyclic hydrocarbons having 5 to 20 carbon atoms such as cyclopentane and cyclohexane, -Monoolefins such as butene, 2-butene, aromatic hydrocarbons such as benzene, toluene, xylene, methylene chloride, chloroform, trichloroethylene, perchloroethylene, 1,2-dichloroethane, chlorobenzene, bromobenzene, chlorotoluene, etc. A halogenated hydrocarbon is mentioned.

As the rare earth element carboxylate, the following general formula (8):
(R ¹⁵ -CO ₂ ) ₃ M ¹ (8)
(Wherein, R ¹⁵ is a hydrocarbyl group having 1 to 20 carbon atoms, and M ¹ is a rare earth element having an atomic number of 57 to 71 in the periodic table). Here, R ¹⁵ may be saturated or unsaturated, is preferably an alkyl group or an alkenyl group, and may be linear, branched or cyclic. The carboxyl group is bonded to a primary, secondary or tertiary carbon atom. Specific examples of the carboxylate include octanoic acid, 2-ethylhexanoic acid, oleic acid, neodecanoic acid, stearic acid, benzoic acid, naphthenic acid, versatic acid [trade names of Shell Chemical Co., Ltd. , A carboxylic acid in which a carboxyl group is bonded to a tertiary carbon atom] and the like. Among these, salts of 2-ethylhexanoic acid, neodecanoic acid, naphthenic acid, and versatic acid are preferable.

As the rare earth element alkoxide, the following general formula (9):
(R ¹⁶ O) ₃ M ² (9)
(Wherein, R ¹⁶ is a hydrocarbyl group having 1 to 20 carbon atoms, and M ² is a rare earth element having an atomic number of 57 to 71 in the periodic table). Examples of the alkoxy group represented by R ¹⁶ O include a 2-ethyl-hexyloxy group, an oleyloxy group, a stearyloxy group, a phenoxy group, and a benzyloxy group. Among these, 2-ethyl-hexyloxy group and benzyloxy group are preferable.

  Examples of the rare earth element β-diketone complex include the rare earth element acetylacetone complex, benzoylacetone complex, propionitrileacetone complex, valerylacetone complex, and ethylacetylacetone complex. Among these, an acetylacetone complex and an ethylacetylacetone complex are preferable.

  Examples of the rare earth element phosphate and phosphite include the rare earth element, bis (2-ethylhexyl) phosphate, bis (1-methylheptyl phosphate), bis (p-nonylphenyl) phosphate, phosphorus Acid bis (polyethylene glycol-p-nonylphenyl), phosphoric acid (1-methylheptyl) (2-ethylhexyl), phosphoric acid (2-ethylhexyl) (p-nonylphenyl), 2-ethylhexylphosphonic acid mono-2-ethylhexyl 2-ethylhexylphosphonic acid mono-p-nonylphenyl, bis (2-ethylhexyl) phosphinic acid, bis (1-methylheptyl) phosphinic acid, bis (p-nonylphenyl) phosphinic acid, (1-methylheptyl) (2 -Ethylhexyl) phosphinic acid, (2-ethylhexyl) (p-nonylphenyl) phosphine Among these, the rare earth elements, bis (2-ethylhexyl) phosphate, bis (1-methylheptyl) phosphate, mono-2-ethylhexyl 2-ethylhexylphosphonate, bis A salt with (2-ethylhexyl) phosphinic acid is preferred.

  Among the rare earth element-containing compounds, neodymium phosphate and neodymium carboxylate are more preferable, and in particular, neodymium branch such as neodymium 2-ethylhexanoate, neodymium neodecanoate, neodymium versatate, etc. Carboxylate is most preferred.

  The component (A) may be a reaction product of the rare earth element-containing compound and a Lewis base. The reaction product has improved solubility of the rare earth element-containing compound in the solvent due to the Lewis base, and can be stably stored for a long period of time. In order to easily solubilize the rare earth element-containing compound in a solvent and to store stably for a long period of time, the Lewis base is used in a proportion of 0 to 30 mol, preferably 1 to 10 mol, per mol of rare earth element. Or as a mixture of the two or as a product obtained by reacting both in advance. Here, examples of the Lewis base include acetylacetone, tetrahydrofuran, pyridine, N, N-dimethylformamide, thiophene, diphenyl ether, triethylamine, an organic phosphorus compound, and a monovalent or divalent alcohol.

  The rare earth element-containing compound as the component (A) described above or a reaction product of these compounds and a Lewis base can be used alone or in combination of two or more.

  In the present invention, the organoaluminum compound represented by the general formula (7), which is the component (B) of the catalyst system used for the polymerization of the terminal active polymer, includes trimethylaluminum, triethylaluminum, tri-n-propylaluminum, Triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-t-butylaluminum, tripentylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum; diethylaluminum hydride, di-n-propyl hydride Aluminum, di-n-butylaluminum hydride, diisobutylaluminum hydride, dihexylaluminum hydride, diisohexylaluminum hydride, dioctylaluminum hydride, dihydride Seo octyl aluminum, ethyl aluminum dihydride, n- propyl aluminum dihydride, include isobutyl aluminum dihydride and the like, among these, triethylaluminum, triisobutylaluminum, hydrogenated diethylaluminum, hydrogenated diisobutylaluminum are preferred. The organoaluminum compound as the component (B) described above can be used alone or in combination of two or more.

  In the present invention, the component (C) of the catalyst system used for the polymerization of the terminal active polymer is at least selected from the group consisting of a Lewis acid, a complex compound of a metal halide and a Lewis base, and an organic compound containing an active halogen. It is a kind of halogen compound.

  The Lewis acid has Lewis acidity and is soluble in hydrocarbons. Specifically, methyl aluminum dibromide, methyl aluminum dichloride, ethyl aluminum dibromide, ethyl aluminum dichloride, butyl aluminum dibromide, butyl aluminum dichloride, dimethyl aluminum bromide, dimethyl aluminum chloride, diethyl bromide Aluminum, diethylaluminum chloride, dibutylaluminum bromide, dibutylaluminum chloride, methylaluminum sesquibromide, methylaluminum sesquichloride, ethylaluminum sesquibromide, ethylaluminum sesquichloride, dibutyltin dichloride, aluminum tribromide, antimony trichloride, Examples include antimony pentachloride, phosphorus trichloride, phosphorus pentachloride, tin tetrachloride, and silicon tetrachloride. Among these, diethylaluminum chloride, sesquiethylaluminum chloride, ethylaluminum dichloride, diethylaluminum bromide, ethylaluminum sesquibromide, and ethylaluminum dibromide are preferable. Alternatively, a reaction product of an alkylaluminum and a halogen such as a reaction product of triethylaluminum and bromine can be used.

  The metal halide constituting the complex compound of the above metal halide and Lewis base includes beryllium chloride, beryllium bromide, beryllium iodide, magnesium chloride, magnesium bromide, magnesium iodide, calcium chloride, calcium bromide, iodine. Calcium chloride, barium chloride, barium bromide, barium iodide, zinc chloride, zinc bromide, zinc iodide, cadmium chloride, cadmium bromide, cadmium iodide, mercury chloride, mercury bromide, mercury iodide, manganese chloride, Manganese bromide, manganese iodide, rhenium chloride, rhenium bromide, rhenium iodide, copper chloride, copper iodide, silver chloride, silver bromide, silver iodide, gold chloride, gold iodide, gold bromide, etc. Of these, magnesium chloride, calcium chloride, barium chloride, manganese chloride, zinc chloride, and copper chloride are preferred. , Magnesium chloride, manganese chloride, zinc chlorides, copper chloride being particularly preferred.

  Moreover, as a Lewis base which comprises the complex compound of the said metal halide and a Lewis base, a phosphorus compound, a carbonyl compound, a nitrogen compound, an ether compound, alcohol, etc. are preferable. Specifically, tributyl phosphate, tri-2-ethylhexyl phosphate, triphenyl phosphate, tricresyl phosphate, triethylphosphine, tributylphosphine, triphenylphosphine, diethylphosphinoethane, diphenylphosphinoethane, acetylacetone, benzoylacetone , Propionitrile acetone, valeryl acetone, ethyl acetylacetone, methyl acetoacetate, ethyl acetoacetate, phenyl acetoacetate, dimethyl malonate, diethyl malonate, diphenyl malonate, acetic acid, octanoic acid, 2-ethyl-hexanoic acid, olein Acid, stearic acid, benzoic acid, naphthenic acid, versatic acid, triethylamine, N, N-dimethylacetamide, tetrahydrofuran, diphenyl ether, 2-ethyl-hexyl alcohol Examples include oleyl alcohol, stearyl alcohol, phenol, benzyl alcohol, 1-decanol, and lauryl alcohol. Among these, tri-2-ethylhexyl phosphate, tricresyl phosphate, acetylacetone, 2-ethylhexanoic acid, versatic acid, 2 -Ethylhexyl alcohol, 1-decanol and lauryl alcohol are preferred.

  The Lewis base is usually reacted at a ratio of 0.01 to 30 mol, preferably 0.5 to 10 mol, per mol of the metal halide. When the reaction product with the Lewis base is used, the metal remaining in the polymer can be reduced. Examples of the organic compound containing the active halogen include benzyl chloride.

  Examples of the aluminoxane as component (D) include methylaluminoxane, ethylaluminoxane, propylaluminoxane, butylaluminoxane, chloroaluminoxane, and the like. By adding aluminoxane as the component (D), the molecular weight distribution becomes sharp and the activity as a catalyst is improved.

The amount or composition ratio of each component of the catalyst system used in the present invention is appropriately selected according to its purpose or necessity. Of these, the component (A) is preferably used in an amount of 0.00001 to 1.0 mmol, more preferably 0.0001 to 0.5 mmol, per 100 g of 1,3-butadiene. When the amount of component (A) used is within the above range, excellent polymerization activity can be obtained, and the need for a deashing step is eliminated.
Moreover, the ratio of (A) component and (B) component is molar ratio, and (A) component: (B) component is usually 1: 1-1: 700, Preferably it is 1: 3-1: 500.
Furthermore, the ratio of the halogen in the component (A) and the component (C) is a molar ratio, usually 1: 0.1 to 1:30, preferably 1: 0.2 to 1:15, more preferably 1: 2.0 to 1: 5.0.
Moreover, the ratio of the aluminum and (A) component in (D) component is molar ratio, and is 1: 1-700: 1 normally, Preferably it is 3: 1-500: 1. By making the amount of these catalysts within the range of the component ratio, it is preferable because it acts as a highly active catalyst and there is no need for a step of removing the catalyst residue.
In addition to the above components (A) to (C), the polymerization reaction may be carried out in the presence of hydrogen gas for the purpose of adjusting the molecular weight of the polymer.

  As a catalyst component, in addition to the component (A), the component (B), the component (C), and the component (D) used as necessary, a conjugated diene monomer such as 1,3-butadiene may be used as necessary. A small amount, specifically, a ratio of 0 to 1000 mol per 1 mol of the compound of component (A) may be used. A conjugated diene monomer such as 1,3-butadiene as a catalyst component is not essential, but when used in combination, there is an advantage that the catalytic activity is further improved.

  In the production of the catalyst, for example, the components (A) to (C) are dissolved in a solvent, and a conjugated diene monomer such as 1,3-butadiene is reacted as necessary. In that case, the addition order of each component is not specifically limited, Furthermore, you may add an aluminoxane as (D) component. From the viewpoint of improving the polymerization activity and shortening the polymerization initiation induction period, it is preferable that these components are mixed in advance, reacted and aged. Here, the aging temperature is about 0 to 100 ° C, preferably 20 to 80 ° C. When the temperature is less than 0 ° C., the aging is not sufficiently performed, and when the temperature exceeds 100 ° C., the catalytic activity may be reduced or the molecular weight distribution may be broadened. The aging time is not particularly limited, and can be ripened by contacting in the line before adding to the polymerization reaction tank. Usually, 0.5 minutes or more is sufficient, and stable for several days.

  In the production of the conjugated diene (co) polymer having terminal activity, a conjugated diene monomer alone or a conjugated diene monomer in an organic solvent using a catalyst system containing the lanthanum series rare earth element-containing compound It can be obtained by solution polymerization of other conjugated diene monomers. Here, an inert organic solvent is used as the polymerization solvent. Examples of the inert organic solvent include saturated aliphatic hydrocarbons having 4 to 10 carbon atoms such as butane, pentane, hexane and heptane, saturated alicyclic hydrocarbons having 5 to 20 carbon atoms such as cyclopentane and cyclohexane, 1- Monoolefins such as butene and 2-butene, aromatic hydrocarbons such as benzene, toluene and xylene, methylene chloride, chloroform, carbon tetrachloride, trichloroethylene, perchloroethylene, 1,2-dichloroethane, chlorobenzene, bromobenzene, chloro And halogenated hydrocarbons such as toluene. Among these, a C5-C6 aliphatic hydrocarbon and alicyclic hydrocarbon are especially preferable. These solvents may be used alone or in a combination of two or more. The monomer concentration in the solvent used for the coordination anionic polymerization is preferably 5 to 50% by mass, more preferably 10 to 30% by mass.

  In the present invention, the temperature in the coordination anionic polymerization reaction is preferably selected in the range of -80 to 150 ° C, more preferably -20 to 120 ° C. The polymerization reaction can be carried out under generated pressure, but it is usually desirable to operate at a pressure sufficient to keep the monomer in a substantially liquid phase. That is, the pressure depends on the particular material being polymerized, the polymerization medium used and the polymerization temperature, but higher pressures can be used if desired, such pressure being a gas that is inert with respect to the polymerization reaction. Can be obtained by an appropriate method such as pressurizing.

  In the case of modifying the active end of the conjugated diene (co) polymer having an active end obtained by the coordinated anionic polymerization reaction, the hydrocarbyloxysilane compound is reacted in advance in the above-described pre-modification reaction step, followed by hydrolysis. And (i) an organic silane compound and the conjugated diene (co) polymer are bonded to each other by performing an addition or substitution reaction on the active site in the vicinity of the characteristic group. A modification reaction may be caused by reacting an organosilane compound having a functional group that promotes the reaction between the silanol group and the reinforcing filler or (ii) a functional group that promotes the reaction between the silanol group and the reinforcing filler. From the viewpoint of smoothly proceeding.

  In the above-mentioned anionic polymerization and coordination anionic polymerization, all the raw materials involved in the polymerization such as polymerization initiator, solvent, monomer, and the like have removed reaction inhibitors such as water, oxygen, carbon dioxide, and protic compounds. It is desirable to use one. The polymerization reaction may be carried out either batchwise or continuously. In this way, a conjugated diene (co) polymer having an active end is obtained.

  In the modified conjugated diene polymer according to the present invention, the cis-1,4 bond content of the conjugated diene moiety is preferably 30% or more, and more preferably 40% or more. If it is less than 30%, the low temperature characteristics of the rubber composition may be deteriorated, and the on-ice performance of the winter tire may be deteriorated.

  The rubber matrix of the rubber composition comprises a total of 10 to 100% by mass of the modified diene rubber and the high molecular weight modified conjugated diene polymer, and a diene rubber (the modified diene rubber and the high molecular weight modified conjugated diene polymer). Other diene rubber) is preferably 90 to 0% by mass, and is composed of a total of 10 to 90% by mass of the modified diene rubber and the high molecular weight modified conjugated diene polymer and 90 to 10% by mass of the diene rubber. More preferably. Here, as the diene rubber, polybutadiene, polyisoprene, butadiene-isoprene copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer other than the above modified diene rubber and high molecular weight modified conjugated diene polymer. Examples thereof include styrene-isoprene-butadiene terpolymer, ethylene-propylene-diene terpolymer, butyl rubber, and halogenated butyl rubber. Of these diene rubbers, natural rubber is preferred. The reason why the total of the modified diene rubber and the high molecular weight modified conjugated diene polymer in the rubber matrix is 10% by mass or more is to improve the wear resistance, fracture resistance, performance on ice, and low rolling resistance. It is.

  The rubber composition is 5 to 200 parts by mass, preferably 20 to 200 parts by mass, more preferably 20 to 120 parts by mass, and even more preferably 30 to 100 parts by mass with respect to 100 parts by mass of the rubber matrix. Is included. When the reinforcing filler is less than 5 parts by mass, the interaction between the modified diene rubber, the high molecular weight modified conjugated diene polymer, the low molecular weight modified conjugated diene polymer and the reinforcing filler can be enjoyed. If the reinforcing filler exceeds 200 parts by mass, the rolling resistance of the winter tire is remarkably increased. In the present invention, the reinforcing filler is preferably carbon black and / or silica.

  Since the modified diene rubber and the high molecular weight modified conjugated diene polymer represented by the general formula (1) or the general formula (2) react with both carbon black and silica, the rubber matrix is modified with the modified diene rubber. Reaction of silica, which tends to exist in natural rubber, and the modified diene rubber and high molecular weight modified conjugated diene polymer when combined with natural rubber and diene rubber and high molecular weight modified conjugated diene polymer , More silica is distributed in the modified diene rubber and the high molecular weight modified conjugated diene polymer, and the dynamic storage elastic modulus E ′ at −20 ° C. of the tread rubber composition is significantly reduced. The tread is more flexible and the performance on ice is further improved. Further, the modified diene rubber and the high molecular weight modified conjugated diene polymer represented by the general formula (1) or the general formula (2) preferably react with both carbon black and silica. Both dispersibility of silica is improved, and the dynamic storage elastic modulus E ′ at 30 ° C. of the tread rubber composition is increased, so that the dry handling stability performance of the tire of the present invention is improved. From the above viewpoint, the rubber matrix includes the modified diene rubber and a combination of a high molecular weight modified conjugated diene polymer represented by the general formula (1) or the general formula (2) and a natural rubber (the modified diene). 10 to 100% by mass of the total of the rubber and the high molecular weight modified conjugated diene polymer and 90 to 0% by mass of natural rubber) are more preferable, and a combination of carbon black and silica (10 to 90% by mass of carbon black) is used as the reinforcing filler. And 90 to 10% by mass of silica, more preferably 20 to 80% by mass of carbon black and 80 to 20% by mass of silica).

The carbon black used as the reinforcing filler preferably has a nitrogen adsorption specific surface area (measured according to N ₂ SA, JIS K 6217-2: 2001) of 70 to 200 m ² / g. Examples of the carbon black in this range include SAF-HS, SAF, ISAF-HS, ISAF, ISAF-LS, N285, N339, HAF-HS, HAF, and HAF-LS. The carbon black nitrogen adsorption specific surface area is particularly preferably from 85 to 180 m ² / g.

Any commercially available silica can be used as the reinforcing filler, and wet silica, dry silica, and colloidal silica are particularly preferable, and wet silica is particularly preferable. The BET specific surface area (measured according to ISO 5794/1) of silica is preferably 100 m ² / g or more, more preferably 150 m ² / g or more, particularly preferably 170 m ² / g or more. Examples of such silica include Tosoh Silica Co., Ltd., trade name “Nipsil AQ” (BET specific surface area = 190 m ² / g), “Nipsil KQ”, Degussa Co., Ltd., trade name “Ultra Gil VN3” (BET specific surface area = 175 m). ² / g) can be used.

In addition to the reinforcing filler, the following inorganic filler may be blended if desired. For example, alumina (Al ₂ O ₃ ), alumina-hydrate (Al ₂ O ₃ .H ₂ O), aluminum hydroxide [Al (OH) ₃ ], aluminum carbonate [Al ₂ (CO ₃ ) ₂ ], water magnesium oxide [Mg (OH) _2], magnesium oxide (MgO), magnesium carbonate (MgCO _3), talc _{(3MgO · 4SiO 2 · H 2} O), attapulgite _{(5MgO · 8SiO 2 · 9H 2} O), titanium white ( TiO ₂ ), titanium black (TiO _2n-1 ), calcium oxide (CaO), calcium hydroxide [Ca (OH) ₂ ], aluminum magnesium oxide (MgO · Al ₂ O ₃ ), clay (Al ₂ O ₃ · 2SiO) _2), kaolin _{(Al 2 O 3 · 2SiO 2} · 2H 2 O), pyrophyllite _{(Al 2 O 3 · 4SiO 2} · H 2 O), bentonite _{(Al 2 O 3 · 4SiO 2} · 2 ₂ O), aluminum silicate _{(Al 2 SiO 5, Al 4} · 3SiO 4 · 5H 2 O etc.), magnesium silicate (Mg ₂ SiO _4, MgSiO ₃ etc.), calcium silicate (Ca ₂ · SiO ₄ etc.) , Aluminum calcium silicate (Al ₂ O ₃ · CaO · 2SiO ₂ etc.), magnesium calcium silicate (CaMgSiO ₄ ), calcium carbonate (CaCO ₃ ), zirconium oxide (ZrO ₂ ), zirconium hydroxide [ZrO (OH) ₂ · nH ₂ O], zirconium carbonate _{[Zr (CO 3) 2]} , and the like crystalline aluminosilicate.

  When silica is blended in the rubber composition, it is preferable that 1 to 20% by mass of a silane coupling agent is blended with respect to the silica. Examples of the silane coupling agent include bis (3-triethoxysilylpropyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, bis (3-methyldimethoxysilylpropyl) tetrasulfide, and bis (3-triethoxy Silylethyl) tetrasulfide, bis (3-triethoxysilylpropyl) disulfide, bis (3-trimethoxysilylpropyl) disulfide, bis (3-methyldimethoxysilylpropyl) disulfide, bis (3-triethoxysilylethyl) disulfide, Bis (3-triethoxysilylpropyl) trisulfide, bis (3-trimethoxysilylpropyl) trisulfide, bis (3-methyldimethoxysilylpropyl) trisulfide, bis (3-triethoxysilylene) Le) sulfur-containing alkoxysilane compounds such trisulfide and the like.

  In the said rubber composition, it is preferable that 1-15 mass parts of foaming agents are mix | blended with respect to 100 mass parts of rubber matrices. Examples of the foaming agent include azodicarbonamide (ADCA), dinitrosopentamethylenetetramine (DPT), dinitrosopentastyrenetetramine, benzenesulfonyl hydrazide derivatives, p, p'-oxybisbenzenesulfonylhydrazide (OBSH), carbon dioxide. Ammonium bicarbonate generated, sodium bicarbonate, ammonium carbonate, nitrososulfonylazo compound generating nitrogen, N, N′-dimethyl-N, N′-dinitrosophthalamide, toluenesulfonyl hydrazide, p-toluenesulfonyl semicarbazide, p , p′-oxybisbenzenesulfonyl semicarbazide and the like. Among these foaming agents, azodicarbonamide (ADCA) and dinitrosopentamethylenetetramine (DPT) are preferable from the viewpoint of production processability. Moreover, these foaming agents may be used individually by 1 type, and may use 2 or more types together.

  There is no restriction | limiting in particular as a form of the said foaming agent, According to the objective, it can select suitably from particulate form, liquid form, etc. The form of the foaming agent can be observed using, for example, a microscope. Moreover, the average particle diameter of a particulate foaming agent can be measured using a Coulter counter etc., for example.

  The foaming agent is preferably used in combination with urea, zinc stearate, zinc benzenesulfinate, zinc white or the like as a foaming aid. These may be used individually by 1 type and may use 2 or more types together. By using a foaming aid in combination, the foaming reaction can be promoted to increase the degree of completion of the reaction, and unnecessary deterioration can be suppressed over time.

The rubber composition preferably has 5 to 50% by volume of air bubbles in the rubber matrix after vulcanization. In addition, the said bubble rate means the bubble rate of a tread, when using this rubber composition for a tread. The bubble rate (Vs) can be calculated by the following equation.
Vs = (ρ ₀ / ρ ₁ −1) × 100 (volume%)
(Wherein, [rho ₁ represents the density of the rubber composition after vulcanization ^{(g / cm 3), ρ} 0 represents the density of the solid phase portion in the rubber composition after vulcanization (g / cm ^3). )
The density of the rubber composition after vulcanization and the density of the solid phase part in the rubber composition after vulcanization are calculated by measuring the mass in ethanol and the mass in air. Further, the bubble ratio (Vs) can be appropriately changed depending on the types and amounts of the above-mentioned foaming agent and foaming aid. The reason why the bubble rate is preferably 5% by volume or more is that the performance on ice can be further improved, and that the bubble rate is preferably 50% by volume or less is more resistant to wear and fracture. It is because it improves.

  The rubber composition is a short fiber made of a thermoplastic resin, and is melted or melted in a matrix of the rubber composition until the temperature of the rubber composition reaches the maximum vulcanization temperature at the time of vulcanization. You may contain the short fiber characterized by softening. Here, the compounding quantity of this short fiber is 0.2-10 mass parts with respect to 100 mass parts of said rubber matrices, Preferably it is 0.5-5 mass parts. The maximum vulcanization temperature means the maximum temperature reached by the rubber composition during vulcanization. For example, in the case of mold vulcanization, it means the maximum temperature that the rubber composition reaches from the time when the rubber composition enters the mold until the rubber composition exits the mold and cools. The maximum vulcanization temperature can be measured, for example, by embedding a thermocouple in the rubber composition. Here, when the rubber composition used for the tire of the present invention contains the above short fibers, after the vulcanization, there are long bubbles in the tire member, for example, the tread, and the long bubbles are formed by wear of the tire member. A hole is formed on the surface and functions as a drainage channel for efficient drainage. Here, the hole portion may be any one of a hole shape, a hollow shape, and a groove shape. Moreover, since the surface of the hole part of the tread is covered with a solidified protective layer of melted or softened short fibers, it is excellent in water channel shape retention, water channel edge wear, water channel retention during load input, and the like. As thickness of a protective layer, 0.5-50 micrometers is preferable.

  The material for the short fiber is not particularly limited as long as it is a thermoplastic resin having the above thermal characteristics, and can be appropriately selected according to the purpose. Preferred examples of the short fibers having the thermal characteristics include short fibers made of a crystalline polymer having a melting point lower than the maximum vulcanization temperature. The short fiber made of the crystalline polymer will be described as an example. The larger the difference between the melting point of the short fiber and the maximum vulcanization temperature of the rubber composition, the faster the short fiber is vulcanized. The fiber melts. On the other hand, when the melting point of the short fiber is too close to the maximum vulcanization temperature of the rubber composition, the short fiber does not melt quickly at the initial stage of vulcanization, and the short fiber melts at the end of vulcanization. At the end of vulcanization, the air present in the short fibers diffuses and is dispersed or taken into the vulcanized rubber composition, and a sufficient amount of air is retained in the melted short fibers. Not. On the other hand, if the melting point of the short fiber is too low, the short fiber is melted by heat at the time of kneading the rubber composition, poor dispersion due to fusion of the short fibers at the kneading stage, and short fiber at the kneading stage. Is disadvantageous in that it is divided into a plurality of lengths, and short fibers are dissolved in the rubber composition and dispersed microscopically.

  The upper limit of the melting point (or softening point) of the short fiber is not particularly limited, but is preferably selected in consideration of the above points. Generally, it is higher than the maximum vulcanization temperature of the rubber composition. It is preferably lower by 10 ° C. or higher, and more preferably lower by 20 ° C. or higher. The industrial vulcanization temperature of the rubber composition is generally about 190 ° C. at the maximum. For example, when the maximum vulcanization temperature is set to 190 ° C., the melting point of the short fiber is Is usually selected within a range of 190 ° C. or lower, preferably 180 ° C. or lower, and more preferably 170 ° C. or lower. On the other hand, considering the kneading of the rubber composition, the melting point (or softening point) of the short fiber is preferably 5 ° C. or more, more preferably 10 ° C. or more, more preferably 20 ° C. with respect to the maximum temperature during kneading. The above is particularly preferable. Assuming that the maximum temperature in kneading the rubber composition is, for example, 95 ° C., the melting point of the short fibers is preferably 100 ° C. or higher, more preferably 105 ° C. or higher, and particularly preferably 115 ° C. or higher. The melting point of the short fiber can be measured using a known melting point measuring device or the like. For example, the melting peak temperature measured using a DSC measuring device can be used as the melting point.

  The short fiber may be formed from the above-described crystalline polymer, may be formed from an amorphous polymer, or may be formed from a crystalline polymer and an amorphous polymer. However, in the present invention, it is preferably formed from an organic material containing a crystalline polymer from the viewpoint that the viscosity change occurs suddenly at a certain temperature due to the phase transition and viscosity control is easy. More preferably, it is formed only from a functional polymer.

  Examples of the crystalline polymer include polyethylene (PE), polypropylene (PP), polybutylene, polybutylene succinate, polyethylene succinate, syndiotactic-1,2-polybutadiene (SPB), polyvinyl alcohol (PVA), Single-composition polymers such as polyvinyl chloride (PVC), those having a melting point controlled to an appropriate range by copolymerization, blending, or the like can be used, and those obtained by adding additives to these can also be used. These may be used individually by 1 type and may use 2 or more types together. Among these crystalline polymers, polyolefins and polyolefin copolymers are preferable, polyethylene (PE) and polypropylene (PP) are more preferable in terms of general availability and easy access, polyethylene (PE) in terms of low melting point and easy handling. ) Is particularly preferred.

  Examples of the non-crystalline polymer include polymethyl methacrylate (PMMA), acrylonitrile / butadiene / styrene copolymer (ABS), polystyrene (PS), polyacrylonitrile, copolymers thereof, and blends thereof. Etc. These may be used individually by 1 type and may use 2 or more types together. Further, the crystalline polymer and the non-crystalline polymer may be used in combination.

  There is no restriction | limiting in particular as the fineness of the said short fiber, Although it can select suitably according to the objective, from a viewpoint of improving the performance on ice and snow, 1-1100dTex is preferable and 2-900dTex is more preferable. The average diameter (D) of the short fibers is not particularly limited and may be appropriately selected depending on the intended purpose. In the vulcanized rubber obtained by vulcanizing a rubber composition containing the short fibers Moreover, in order to efficiently form long bubbles that can function as micro drainage grooves, 0.03 to 0.3 mm is preferable, and 0.06 to 0.25 mm is more preferable. When the average diameter (D) is less than 0.03 mm, it is difficult to form a long cylindrical foaming groove, and it is not preferable in that a lot of thread breakage occurs during the production of short fibers, and exceeds 0.3 mm. And the average diameter (diameter) of the said short fiber becomes large, and when it is the same compounding quantity, the number of cylindrical foaming grooves will reduce, and there exists a tendency for drainage efficiency to worsen.

  The rubber composition preferably contains fine particles having an average major axis of 5 to 1000 μm, preferably 5 to 500 μm, preferably 3 to 30 parts by weight, more preferably 3 to 15 parts by weight with respect to 100 parts by weight of the rubber matrix. But it ’s okay. This fine particle (1) scratches the road surface on ice on the tread surface, and (2) the fine particle is detached from the tread, and a hole is formed in the surface layer part of the tread (tread surface and its vicinity). It forms and drains the melted water from the ice on the ice. The average major axis of the fine particles refers to the average maximum diameter. Here, the average major axis of the fine particles is preferably 5 μm or more because the performance on ice is further improved due to the scratch effect, and the average major axis of the fine particles is preferably 1000 μm or less because of wear resistance. This is because the fracture resistance is further improved. The reason why it is preferable to contain 3 parts by mass or more of fine particles is that the performance on ice is further improved, and that the reason why it is preferable to contain 15 parts by mass or less of fine particles is to further improve wear resistance and fracture resistance. Because. The average major axis is obtained by randomly selecting 100 fine particles with an electron microscope, measuring each major axis, and arithmetically averaging the measured 100 major axes.

  The fine particles preferably have an aspect ratio of 1.1 or more, and preferably have corners. More preferably, the aspect ratio is 1.2 or more, and further preferably 1.3 or more. Here, the presence of a corner means that the entire surface is not a spherical surface or a smooth curved surface. Fine particles having corners can be used from the beginning as the above-mentioned fine particles, but even if the fine particles are spherical, they can be used in the presence of corners on the surface of the fine particles, and more corners can be used. Can exist.

  The fine particles blended in the rubber composition are not limited to those described above, and any fine particles may be used as long as they are present after vulcanization without being softened by vulcanization of the tire. As the fine particles, fine particles having a Mohs hardness of 2 or more are preferable. For example, gypsum fine particles, calcite fine particles, fluorite fine particles, feldspar fine particles, quartz fine particles, olivine fine particles, iron fine particles, eggshell powder, zirconium oxide fine particles, calcium carbonate Plant fine particles, silica fine particles, wollastonite fine particles, alkali feldspar fine particles, natural silicon oxide fine particles, inorganic fine particles such as porous natural glass (for example, Mohs hardness 5) fine particles, walnut shells and other seed shells and fruit nuclei Fine particles, organic cured fine particles such as (meth) acrylic cured resin fine particles, epoxy cured resin fine particles, zinc oxide whiskers (for example, Panatetra (tetrapot-shaped zinc oxide) manufactured by Matsushita Amtech Co., Ltd.), stars from Okinawa Prefecture Sand, glass fiber, aluminum whisker, polyester fiber, nylon fiber, polyvinyl alcohol Examples thereof include short fibers that do not soften or melt at the vulcanization temperature of tires such as marl fibers and aromatic polyamide fibers, expanded graphite, thermally expanded microcapsules, and shirasu balloons. More preferably, silica glass having a Mohs hardness of 5 or more ( Examples include Mohs hardness 6.5), quartz (Mohs hardness 7.0), and fused alumina (Mohs hardness 9.0). Among these, alumina (aluminum oxide) such as single crystal alumina and polycrystalline alumina, silica glass, and the like are particularly preferable because they are inexpensive and can be used easily.

  The above expanded graphite is a powder substance having an average major axis of 30 to 600 μm, preferably 100 to 350 μm as a particle size including a substance that is vaporized by heat between layers of graphite particles, and expands by heat during vulcanization. It is preferable that it becomes a graphite expanded body (Expanded Graphite). Expanded graphite has a structure in which sheets formed from carbon atoms overlap each other and includes a vaporizable interlayer material between the layers. For example, the interlayer material is vaporized and expanded by heating to form a graphite expanded body. Since the material is hard before the expansion treatment, quality deterioration due to mixing hardly occurs, and since it irreversibly expands at a constant temperature, it is possible to easily form a foreign substance with a space inside the rubber matrix by vulcanizing the tire. . The tread part of a tire using such rubber has moderate surface irregularities when worn like other fine particles, and improves the frictional force on ice by efficiently removing the water film on the contact surface between ice and the tire. It moves to.

  As the expanded graphite having an expansion start temperature of 190 ° C. or lower, for example, “Graph Guard 160-50” or “Graph Guard 160-80” manufactured by UCAR Graphtech of the United States is commercially available from Sakai Industries. . Expanded graphite refers to an unexpanded product immediately after acid treatment in terms of term, but may also refer to an already expanded product after heat treatment. The expanded graphite blended as a rubber composition in the present invention is an unexpanded product before heat treatment.

  The thermal expansion microcapsules described above are powder particles in which a liquid or solid that is vaporized, decomposed, or chemically reacted by heat to generate a gas is encapsulated in a thermoplastic resin, and have a temperature equal to or higher than the expansion start temperature, usually 140. It expands when heated at a temperature of ˜190 ° C., and a gas is contained in the outer shell made of the thermoplastic resin, and the average major axis of the thermoplastic resin particles is preferably 5 to 300 μm before expansion, More preferably, the average major axis is 10 to 200 μm.

  As such heat-expandable thermoplastic resin particles, for example, the product name “Expancel 091DU-80” or “Expancel 092DU-120” is currently available from EXPANCEL, Sweden, or from Matsumoto Yushi. The name “Matsumoto Microsphere F-85” or “Matsumoto Microsphere F-100” is available.

  As described above, it is preferable that the fine particles are detached from the tread to form holes in the tread surface layer portion (tread surface and its vicinity). For this purpose, the fine particles are bonded to the tread rubber composition by vulcanization. It is desirable that the vulcanized adhesive strength is low.

  When the fine particles are blended with the rubber composition, they may be blended as non-linear fine particle-containing resin bodies containing fine particles. Here, the fine particle-containing resin body is preferably blended in an amount of 3 to 30 parts by mass with respect to 100 parts by mass of the rubber matrix, and the average particle size of the fine particle-containing resin body is preferably 10 to 1000 μm. This resin body melts or softens in the matrix of the rubber composition until the temperature of the rubber composition reaches the maximum vulcanization temperature when the tire is vulcanized, and melts when the tire is vulcanized. Or it consists of a material similar to the short fiber to soften. In addition, the measuring method of the average particle diameter of the fine particle-containing resin body is the same as the measuring method of the average long diameter of the fine particles.

  Further, fine particles are contained in the above-mentioned short fibers that melt or soften in the matrix of the rubber composition until the temperature of the rubber composition reaches the maximum vulcanization temperature at the time of vulcanization of the tire. You may mix | blend as a fiber. The structure and material of the short fiber that melts or softens when the tire is vulcanized are as described above. The blending amount of the fine particle-containing short fibers is preferably 3 to 20 parts by mass, and more preferably 3 to 15 parts by mass with respect to 100 parts by mass of the rubber matrix of the rubber composition.

  If necessary, the rubber composition may further contain 1 to 50 parts by mass of a softening agent with respect to 100 parts by mass of the rubber matrix. It is because processability is improved by blending the softener. In addition, when blending both the low molecular weight modified conjugated diene polymer and the softener, the total blended amount of the low molecular weight modified conjugated diene polymer and the softener is 100 parts by weight of the rubber matrix. It is preferable that it is 6-60 mass parts. This is because the workability is improved when it is 6 parts by mass or more, and the wear resistance and fracture resistance are improved when it is 60 parts by mass or less. From these viewpoints, the total amount of the low molecular weight modified conjugated diene polymer and the softening agent is preferably 6 to 55 parts by mass, and more preferably 6 to 50 parts by mass.

  In the rubber composition, the softening agent to be blended as desired has a low pour point (for example, about pour point −10 to −60 ° C., preferably pour point −20 to −60 ° C., more preferably pour point − 30 to -60 ° C) Process oil such as naphthenic process oil and paraffinic process oil, or plastic such as dibutyl phthalate, di- (2-ethylhexyl) phthalate, butyl benzyl phthalate, di-n-octyl phthalate Agents.

  The rubber composition is preferably sulfur crosslinkable, and sulfur is suitably used as a vulcanizing agent. The amount used is preferably 0.1 to 10 parts by mass of sulfur (total amount of sulfur and sulfur donors) with respect to 100 parts by mass of the rubber matrix. This is because within this range, the necessary elastic modulus and strength of the vulcanized rubber composition can be ensured and fuel efficiency can be obtained. In this respect, it is more preferable to blend 0.5 to 7 parts by mass of the sulfur content.

  In the rubber composition, as long as the object of the present invention is not impaired, various chemicals usually used in the rubber industry, for example, vulcanizing agents other than sulfur, vulcanization accelerators, process oils, anti-aging agents are used as desired. Further, a scorch inhibitor, zinc white, stearic acid, thermosetting resin, thermoplastic resin, and the like can be contained.

  The vulcanization accelerator that can be used in the rubber composition is not particularly limited. For example, M (2-mercaptobenzothiazole), DM (dibenzothiazyl disulfide), CZ (N-cyclohexyl-2-benzo). Examples thereof include thiazole-based vulcanization accelerators such as thiazylsulfenamide) and guanidine-based vulcanization accelerators such as DPG (diphenylguanidine). The amount used is 0.1 to 100 parts by mass of the rubber matrix. 5.0 parts by mass is preferable, and more preferably 0.2 to 3.0 parts by mass.

  Further, examples of the anti-aging agent that can be used in the rubber composition include 3C (N-isopropyl-N′-phenyl-p-phenylenediamine, 6C [N- (1,3-dimethylbutyl) -N′-phenyl-). p-phenylenediamine], AW (6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline), high-temperature condensate of diphenylamine and acetone, etc. The amount used is rubber matrix 100. 0.1-6.0 mass parts is preferable with respect to mass part, More preferably, it is 0.3-5.0 mass part.

  In addition to the modified diene rubber, the high molecular weight modified conjugated diene polymer, the low molecular weight modified conjugated diene polymer, and the reinforcing filler, the rubber composition is blended with various compounding agents appropriately selected as necessary. And it can manufacture by kneading | mixing by kneading machines, such as a Banbury mixer, a roll, an internal mixer, heating, and extrusion.

  The tire according to the present invention is characterized in that the rubber composition described above is used in any of the tire members, and the tire member is preferably a tread. In addition, the tire of the present invention is preferable as a winter tire because it has excellent performance on ice, steering stability on dry road surfaces, and wear resistance, and has low rolling resistance. The tire of the present invention is not particularly limited except that the rubber composition described above is used for any of the tire members, and can be produced according to a conventional method. Moreover, as gas with which this tire is filled, inert gas, such as nitrogen, argon, helium other than normal or the air which adjusted oxygen partial pressure, can be used.

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to the following examples.
In addition, the weight average molecular weight (Mw) before the modification of the high molecular weight modified conjugated diene polymer and the low molecular weight modified conjugated diene polymer according to the present invention, the bound styrene content and the vinyl bond content, and the winter tire on ice. The performance, dry handling stability performance, rolling resistance performance and wear resistance were measured according to the following methods.

<Weight average molecular weight (Mw) before modification>
It measured using GPC [The Tosoh make, HLC-8020] using the refractometer as a detector, and showed it by polystyrene conversion which used the monodisperse polystyrene as a standard. The column is GMHXL [manufactured by Tosoh] and the eluent is tetrahydrofuran.
<Bound styrene content>
It was determined by calculating the integral ratio of the spectrum by ¹ H-NMR.
<Vinyl bond content>
It calculated | required by the infrared method (Morero method).
<Performance on ice>
At the test course on the icy road surface, the test tires were mounted on all four wheels of the passenger car, and the braking distance on the icy road surface was measured at an initial speed of 20 km. The larger the index value, the better the performance on ice.
Performance on ice (index) = (braking distance of tire of comparative example 1 / braking distance of test tire) × 100
<Dry maneuvering stability>
Using the produced rubber composition as a tread member, a pneumatic tire having a tire size of 195 / 60R15 was fabricated with a tread having a single layer structure.
The prototype tire was mounted on four wheels of a passenger car, and a test driver ran on the test course in this test vehicle. The feeling of the driving stability and riding comfort on the dry road surface of each tire by the test driver was rated according to the following evaluation criteria in comparison with the control tire (Comparative Example 1).
+4: When a driver feels good enough to understand a general driver +3: When a driver feels good enough to understand a skilled driver +2: When a driver feels good enough to clearly understand a test driver +1: A test driver is subtly When it feels good enough to understand 0: When the difference with the control tire is not felt -1: When the test driver feels bad enough to understand -2: When the test driver feels bad enough to understand- 3: When a general driver feels bad enough for an expert driver to understand -4: When a general driver feels bad enough to understand <Rolling resistance performance>
Based on SAE J2452, the rolling resistance of each prototype tire was measured, and the rolling resistance of the tire of Comparative Example 1 was taken as 100, and the index was expressed by the following formula. It shows that rolling resistance is so small that index value is large.
Rolling resistance performance (index) = (Rolling resistance of tire of Comparative Example 1 / Rolling resistance of test tire) × 100
<Abrasion resistance>
For the vulcanized rubber obtained by vulcanizing the rubber composition at 145 ° C. for 33 minutes, the amount of wear at a slip rate of 60% at room temperature was measured using a Lambone type wear tester. The reciprocal was set as 100 and expressed as an index. The larger the index value, the smaller the wear amount and the better the wear resistance.

<Production Example 1: Modified Diene Rubber A>
(Natural rubber latex modification reaction process)
The field latex was centrifuged using a latex separator [manufactured by Saito Centrifugal Industries Co., Ltd.] at a rotational speed of 7500 rpm to obtain a concentrated latex having a dry rubber concentration of 60%. 1000 g of this concentrated latex was put into a stainless steel reaction vessel equipped with a stirrer and a temperature control jacket, and 1000 g of water was added. Thereafter, 9.0 g of potassium persulfate and 3.0 g of propionaldehyde were added and reacted with stirring at 60 ° C. for 30 hours to obtain an oxidized natural rubber latex. Next, formic acid was added to adjust the pH to 4.7 to coagulate. This solid was treated 5 times with a creper and crushed through a shredder.

(Modification process)
After determining the dry rubber content of the obtained coagulum, 600 g of the coagulum and an emulsion solution of 3.0 g of isonicotinohydrazide in terms of dry rubber were mixed at 30 rpm at room temperature in a kneader (prebreaker). The modified diene rubber A was kneaded for 1 minute and dispersed uniformly and dried. Further, the unmodified hydrazide compound was separated by extracting the modified diene rubber A with petroleum ether and further extracting with a 2: 1 mixed solvent of acetone and methanol. Thus, the addition amount of isonicotinohydrazide in the modified diene rubber A was 0.51% by mass relative to the rubber component in the natural rubber latex. Further, gel permeation chromatography [GPC: Tosoh HLC-8020, column: Tosoh GMH-XL (two in series), detector: differential refractometer (RI)], modified monoene based on monodisperse polystyrene. It was 873,000 when the weight average molecular weight (Mw) of polystyrene conversion of the system rubber A was calculated | required.

<Production Example 2: Modified Diene Rubber B>
(Natural rubber latex modification reaction process)
The field latex was centrifuged at a rotational speed of 7500 rpm using a latex separator (manufactured by Saito Centrifugal Co., Ltd.) to obtain a concentrated latex having a dry rubber concentration of 60%. 1000 g of this concentrated latex is put into a stainless steel reaction vessel equipped with a stirrer and a temperature control jacket, and 10 mL of water and 90 mg of emulsifier “Emulgen 1108” (manufactured by Kao Corporation) are added to 1.7 g of 4-vinylpyridine. In addition, the emulsified product was added with 990 mL of water and stirred for 30 minutes while purging with nitrogen. Next, 1.2 g of tert-butyl hydroperoxide and 1.2 g of tetraethylenepentamine were added and reacted at 40 ° C. for 1 hour to obtain a modified natural rubber latex.

(Coagulation and drying process)
Next, formic acid was added to the modified natural rubber latex to adjust the pH to 4.7 to coagulate the modified natural rubber latex. The solid material thus obtained was treated with a creper five times, passed through a shredder and crushed, and then dried at 110 ° C. for 210 minutes with a hot air drier to obtain a modified diene rubber B. From the mass of the modified diene rubber B thus obtained, it was confirmed that the conversion rate of the added 4-vinylpyridine was 100%. In addition, the modified diene rubber B was extracted with petroleum ether and further extracted with a 2: 1 mixed solvent of acetone and methanol, and separation of the homopolymer was attempted. However, when the extract was analyzed, the homopolymer was detected. It was confirmed that 100% of the added monomer was introduced into the natural rubber molecule. Further, the weight average molecular weight (Mw) of the modified diene rubber B was determined in the same manner as in the modified diene rubber A, and it was 1,298,000.

<Production Example 3: Natural rubber C>
Formic acid was added to the field latex to adjust the pH to 4.7 to coagulate the field latex. The solid material thus obtained was treated with a creper five times, passed through a shredder and crushed, and then dried at 110 ° C. for 210 minutes with a hot air dryer to obtain natural rubber C. Further, the weight average molecular weight (Mw) of the natural rubber C was determined in the same manner as in the modified diene rubber A, and it was 1,263,000.

<Production Example 4: High molecular weight unmodified conjugated diene polymer A>
Into a pressure-resistant glass container having an internal volume of about 900 ml that has been dried and purged with nitrogen, 283 g of cyclohexane, 100 g of 1,3-butadiene monomer, and 0.015 mmol of 2,2-ditetrahydrofurylpropane are injected as a cyclohexane solution. After adding 50 mmol of n-butyllithium (BuLi), polymerization was carried out for 4.5 hours in a 50 ° C. warm water bath equipped with a stirrer. The polymerization conversion rate was almost 100%. Thereafter, the reaction was stopped by adding 0.5 ml of a 5 mass% solution of 2,6-di-tert-butyl-p-cresol (BHT) in 5% by weight of isopropanol. A modified conjugated diene polymer A was obtained. The obtained high molecular weight unmodified conjugated diene polymer A had a vinyl bond content of 20% and a weight average molecular weight (Mw) of 300,000.

<Production Example 5: High molecular weight modified conjugated diene polymer B>
Into a pressure-resistant glass container having an internal volume of about 900 ml that has been dried and purged with nitrogen, 283 g of cyclohexane, 100 g of 1,3-butadiene monomer, and 0.015 mmol of 2,2-ditetrahydrofurylpropane are injected as a cyclohexane solution. After adding 50 mmol of n-butyllithium (BuLi), polymerization was carried out for 4.5 hours in a 50 ° C. warm water bath equipped with a stirrer. The polymerization conversion rate was almost 100%. To this polymerization system, 0.50 mmol of 3- [N, N-methyl (trimethylsilyl) amino] propyldimethylethoxysilane was added as a cyclohexane solution and stirred at 50 ° C. for 30 minutes. Thereafter, 0.5 ml of 2,6-di-tert-butyl-p-cresol (BHT) isopropanol 5% by mass solution was added to stop the reaction, followed by drying according to a conventional method, thereby modifying the high molecular weight. A conjugated diene polymer B was obtained. The obtained high molecular weight modified conjugated diene polymer B had a vinyl bond content of 20% and a weight average molecular weight (Mw) before modification of 300,000.

<Production Example 6: High molecular weight modified conjugated diene polymer C>
In Production Example 5, except that 0.50 mmol of 3- [N, N-methyl (trimethylsilyl) amino] propyldimethylethoxysilane was changed to 0.50 mmol of N, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane In the same manner as in Example 5, a high molecular weight modified conjugated diene polymer C was obtained. The obtained high molecular weight modified conjugated diene polymer C had a vinyl bond content of 20% and a weight average molecular weight (Mw) before modification of 300,000.

<Production Example 7: Low molecular weight unmodified conjugated diene polymer D>
Into a pressure-resistant glass container having an internal volume of about 900 ml that has been dried and purged with nitrogen, 283 g of cyclohexane, 25 g of 1,3-butadiene monomer, and 0.015 mmol of 2,2-ditetrahydrofurylpropane are injected as a cyclohexane solution. After adding 50 mmol of n-butyllithium (BuLi), polymerization was carried out in a 50 ° C. hot water bath equipped with a stirrer for 4.5 hours. The polymerization conversion was almost 100%. Thereafter, 0.5 ml of a 5% solution of 2,6-di-t-butyl-p-cresol (BHT) in isopropanol was added to stop the reaction, followed by drying according to a conventional method, whereby low molecular weight unmodified conjugate. Diene polymer D was obtained. The resulting low molecular weight unmodified conjugated diene polymer D had a vinyl bond content of 20% and a weight average molecular weight (Mw) before modification of 80 × 10 ³ .

<Production Example 8: Low molecular weight modified conjugated diene polymer E>
Into a pressure-resistant glass container having an internal volume of about 900 ml that has been dried and purged with nitrogen, 283 g of cyclohexane, 25 g of 1,3-butadiene monomer, and 0.015 mmol of 2,2-ditetrahydrofurylpropane are injected as a cyclohexane solution. After adding 50 mmol of n-butyllithium (BuLi), polymerization was carried out in a 50 ° C. hot water bath equipped with a stirrer for 4.5 hours. The polymerization conversion was almost 100%. To this polymerization system, 0.50 mmol of tin tetrachloride (SnCl ₄ ) was added as a cyclohexane solution and stirred at 50 ° C. for 30 minutes. Thereafter, 0.5 ml of a 5% solution of 2,6-di-t-butyl-p-cresol (BHT) in isopropanol was added to stop the reaction, and further dried according to a conventional method to thereby reduce the low molecular weight modified conjugated diene system. Polymer E was obtained. The obtained low molecular weight modified conjugated diene polymer E had a vinyl bond content of 20% and a weight average molecular weight (Mw) before modification of 80 × 10 ³ .

(Examples 1-2 and Comparative Examples 1-8)
Using the natural rubber and conjugated diene polymer obtained in Production Examples 1 to 8, rubber compositions of Examples 1 and 2 and Comparative Examples 1 to 8 were prepared according to the formulation shown in Table 1. Next, these rubber compositions are respectively arranged on the treads of studless tires (tire size 195 / 60R15), which are winter tires, and 10 types of studless tires are manufactured according to a conventional method. According to each of the above methods, the on-ice performance, dry handling stability performance, rolling resistance performance and wear resistance were evaluated. The results are shown in Table 1.

* 1 Carbon black: ISAF {N ₂ SA (m ² / g) = 115 (m ² / g)}, product name “Asahi # 80” manufactured by Asahi Carbon Co., Ltd.
* 2 Silica: Tosoh Silica Co., Ltd., trade name “Nipsil AQ” (BET specific surface area = 190 m ² / g)
* 3 Silane coupling agent: bis (3-triethoxysilylpropyl) tetrasulfide, manufactured by Degussa, trade name “Si69”
* 4 Anti-aging agent 6C: N- (1,3 dimethylbutyl) -N′-phenyl-p-phenylenediamine, manufactured by Seiko Chemical Co., Ltd., trade name “Ozonon 6C”
* 5 Vulcanization accelerator MBTS: Dibenzothiazyl disulfide, manufactured by Ouchi Shinsei Chemical Industry Co., Ltd., trade name “Noxeller DM”
* 6 Vulcanization accelerator CBS: N-cyclohexyl-2-benzothiazylsulfenamide, manufactured by Ouchi Shinsei Chemical Industry Co., Ltd., trade name “Noxeller CZ”
* 7 Vulcanization accelerator DPG: Diphenylguanidine, manufactured by Ouchi Shinsei Chemical Co., Ltd. Product name “Noxeller D”
* 8 Foaming agent: {Dinitrosopentamethylenetetramine (DPT)} / Urea} = 1/1 (mass ratio) mixture
* 9 Calculated from the above formula.

  From the results of Table 1, tires of examples using a rubber composition formed by combining a modified diene rubber, a high molecular weight modified conjugated diene polymer, a low molecular weight modified conjugated diene polymer, and a reinforcing filler are compared. Compared to the tires of the examples, it can be seen that the performance on ice, the stability of dry handling, the rolling resistance performance and the wear resistance are highly balanced.

Claims (24)

After oxidation of the diene rubber latex, a modified diene rubber obtained by adding a polar group-containing hydrazide compound to the end of the molecular chain of the diene rubber, and a weight average molecular weight before modification exceeding 15 × 10 ⁴ and 200 × 10 ^For 100 parts by mass of a rubber matrix containing a high molecular weight modified conjugated diene polymer that is ⁴ or less,
A rubber composition comprising 5 to 50 parts by mass of a low molecular weight modified conjugated diene polymer having a weight average molecular weight of 2 × 10 ³ to 15 × 10 ⁴ before modification and 20 to 200 parts by mass of a reinforcing filler. A tire characterized by being used for any of tire members.   The bonded aromatic vinyl content (X) (% by mass) of the low molecular weight modified conjugated diene polymer and the vinyl bond content (Y) (%) of the conjugated diene moiety satisfy X + (Y / 2) <25. The tire according to claim 1.   The low molecular weight modified conjugated diene-based polymer contains at least one functional group selected from the group consisting of a tin-containing functional group, a silicon-containing functional group, and a nitrogen-containing functional group. Tire described in.   The tire according to any one of claims 1 to 3, wherein the low molecular weight modified conjugated diene polymer is low molecular weight modified polybutadiene and / or low molecular weight modified polyisoprene.   The high molecular weight modified conjugated diene polymer contains at least one functional group selected from the group consisting of a tin-containing functional group, a silicon-containing functional group, and a nitrogen-containing functional group. The tire according to any one of the above.   The tire according to any one of claims 1 to 5, wherein the high molecular weight modified conjugated diene polymer is a modified polybutadiene rubber and / or a modified polyisoprene rubber.   The tire according to any one of claims 1 to 6, wherein the reinforcing filler is carbon black and / or silica.   The rubber matrix is composed of a total of 10 to 100% by mass of the modified diene rubber and the high molecular weight modified conjugated diene polymer, and 90 to 0% by mass of the diene rubber. The tire according to any one of the above.   The tire according to any one of claims 1 to 8, wherein the rubber composition further contains 3 to 30 parts by mass of fine particles having an average major axis of 5 to 1000 µm with respect to 100 parts by mass of the rubber matrix.   The tire according to claim 3 or 5, wherein the silicon-containing functional group is a dialkoxysilane compound residue or a trialkoxysilane compound residue.   The tire according to claim 3 or 5, wherein the nitrogen-containing functional group or the silicon-containing functional group has a primary amino group. The low molecular weight modified conjugated diene polymer and / or the high molecular weight modified conjugated diene polymer is represented by the following general formula (1) or the following general formula (2). The tire according to any one.

[Wherein, R ¹ and R ³ are each independently —OR, —OH or an alkyl group having 1 to 20 carbon atoms, R ² is an alkylene group having 1 to 20 carbon atoms, and R is a sulfur atom, oxygen It is a C1-C20 hydrocarbyl group which may have an atom, nitrogen atom and / or halogen atom]

[Wherein, R ⁴ and R ⁶ are each independently —OR, —OH or an alkyl group having 1 to 20 carbon atoms, and R ⁵ and R ⁷ are each independently an alkylene group having 1 to 20 carbon atoms, R is a hydrocarbyl group having 1 to 20 carbon atoms which may have a sulfur atom, an oxygen atom, a nitrogen atom and / or a halogen atom, M is Si, Ti, Sn, Bi, Zr or Al; ⁸ is —OH, a hydrocarbyl group having 1 to 30 carbon atoms, a hydrocarbyl carboxyl group having 2 to 30 carbon atoms, a 1,3-dicarbonyl-containing group having 5 to 20 carbon atoms, a hydrocarbyloxy group having 1 to 20 carbon atoms, and A group selected from the group consisting of a siloxy group trisubstituted with a hydrocarbyl group having 1 to 20 carbon atoms and / or a hydrocarbyloxy group having 1 to 20 carbon atoms, and a plurality of R ⁸ may be the same or different; k is { M is the number of valence) -2}, n is 0 or 1]   The low molecular weight modified conjugated diene polymer and / or the high molecular weight modified conjugated diene polymer has a CN bond at a polymerization initiation terminal of the polymer. The described tire.   The tire according to any one of claims 1 to 13, wherein the diene rubber latex is a natural rubber latex.   15. The addition amount of the polar group-containing hydrazide compound is 0.01 to 5.0% by mass with respect to the rubber component in the diene rubber latex. tire.   The polar group of the polar group-containing hydrazide compound is amino group, imino group, nitrile group, ammonium group, imide group, amide group, hydrazo group, azo group, diazo group, hydroxyl group, carboxyl group, carbonyl group, epoxy group, oxy group The tire according to any one of claims 1 to 15, wherein the tire is at least one selected from the group consisting of a carbonyl group, a nitrogen-containing heterocyclic group, an oxygen-containing heterocyclic group, a tin-containing group, and an alkoxysilyl group. .   The tire according to any one of claims 1 to 16, wherein the modified diene rubber has a polystyrene-reduced weight average molecular weight of 200,000 or more as measured by gel permeation chromatography.   The tire according to any one of claims 1 to 17, wherein the oxidation of the diene rubber latex is performed by adding a carbonyl compound to the diene rubber latex and performing air oxidation.   The tire according to claim 18, wherein the air oxidation is performed in the presence of a radical generator.   The tire according to claim 18, wherein the carbonyl compound is an aldehyde and / or a ketone.   The tire according to claim 19, wherein the radical generator is selected from the group consisting of a peroxide radical generator, a redox radical generator, and an azo radical generator. The modified diene rubber has the following general formula (I) at the end of the molecular chain of the diene rubber:

(In the formula, R ^I is an amino group, imino group, nitrile group, ammonium group, imide group, amide group, hydrazo group, azo group, diazo group, hydroxyl group, carboxyl group, carbonyl group, epoxy group, An alkylene group having 1 to 4 carbon atoms having at least one polar group selected from the group consisting of an oxycarbonyl group, a tin-containing group and an alkoxysilyl group, a phenylene group having at least one polar group as a substituent, or nitrogen-containing It has a polar group-containing functional group represented by (at least one kind of polar group selected from the group consisting of a heterocyclic group and an oxygen-containing heterocyclic group). Tires.   The tire according to any one of claims 1 to 22, wherein the tire member is a tread.   The tire according to any one of claims 1 to 23, wherein the rubber composition has 5 to 50% by volume of air bubbles in the rubber matrix after vulcanization.