JP5189253B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire, and more particularly to a pneumatic tire that simultaneously improves braking performance on wet road surfaces, braking performance on snow and icy road surfaces, and braking performance on dry road surfaces.

In recent years, there has been an increasing demand for pneumatic tires that simultaneously improve braking performance on wet road surfaces, braking performance on snow and icy road surfaces, and braking performance on dry road surfaces from the viewpoint of safe driving of automobiles.
As a means for improving the braking performance on wet road surfaces (wet grip braking performance), it is known that the amount of silica added as a reinforcing filler may be increased. However, in this case, since the blending amount of carbon black, which is a reinforcing filler generally used so far, is relatively reduced, there arises a problem that the breaking strength and wear resistance characteristics of the tire are lowered. Further, the dispersibility of silica is poor, and the workability at the time of kneading has become a big problem in actually manufacturing tires.
In order to improve wet grip performance, as a means of increasing the coefficient of friction on the wet road surface, using a rubber composition mainly composed of a styrene-butadiene copolymer that exhibits a relatively high glass transition temperature than conventional, A technique for increasing tan δ at 0 ° C. as a measure of hysteresis showing a good correlation with a coefficient of friction on a wet road surface is known (see, for example, Patent Document 1). However, in this case, with regard to braking performance on ice and snow, the rubber elastic modulus in the low temperature region increases and it becomes impossible to follow the unevenness of the road surface, and the surface of the tread is less on the frozen road surface than the normal road. As a result of less deformation, the energy loss (tan δ) generated between the rubber and the road surface contributes less to braking on ice and snow.

On the other hand, studless tires are known as tires with improved braking performance on snow and icy road surfaces (braking performance on ice and snow). In order to increase the frictional force with the snowy road surface, the studless tire tread is generally made of a flexible rubber material such as a polymer having a lower glass transition temperature than that of a normal tire, in particular a rubber mainly composed of butadiene rubber. . Further, in a tire having a tread portion having a cap / tread two-layer structure, the cap rubber on the tread surface portion in contact with the ground is a relatively soft rubber even at a low temperature, for example, a large amount of a softening agent or a foam rubber. The technique of using is used. However, in these cases, although the braking performance on ice and snow is improved to some extent, there is a problem in that the braking performance on wet roads on general roads is unavoidable.
In addition, it is known to increase the blending amount of the reinforcing filler in order to improve the braking performance (dry grip performance) on the dry road surface, but in this case, the braking performance on ice and snow is reduced, and Low fuel consumption is also reduced. As described above, it is difficult to obtain a pneumatic tire in which wet grip performance, braking performance on ice and snow, and dry grip performance are balanced at a high level.

Japanese Patent Laid-Open No. 5-269884 JP 2005-015590 A

  An object of the present invention is to provide a pneumatic tire in which wet grip performance, braking performance on snow and snow, and dry grip performance are simultaneously improved under such circumstances.

This inventor repeated earnest research in order to develop the pneumatic tire which has the said preferable property, and paid attention to the matter shown below first. When improving the braking performance on dry and wet road surfaces, increasing the rigidity of the tire tread at low temperatures reduces the braking performance on snow and icy road surfaces. It is only necessary to distribute the rubber composition with increased grip properties to the tire tread part while reducing the rigidity of the part, making the tire tread part rigidity equal to or higher than that of the current product tire in the region of 20 ° C. or higher. Pay attention.
As a result of further research based on this focus, the present inventor determined a modified conjugated diene polymer obtained by a specific method and a low molecular weight styrene-butadiene copolymer rubber having a specific molecular weight respectively. It has been found that a pneumatic tire using a rubber composition containing a rubber component contained at a ratio of can be adapted to the purpose. The present invention has been completed based on such findings.
That is, the present invention
(1) (A) (A -1) cis-1,4-active end of the polybutadiene content of more than 75 mol% of the binding, modified polybutadiene 5-50 comprising modified by at least hydrocarbyloxy silane compound mass% (A-2) styrene-butadiene copolymer rubber having a weight average molecular weight of 20,000 to 150,000, 4 to 45% by mass, and (A-3) styrene-butadiene copolymer other than (A-2) be empty pneumatic tire using the rubber composition containing a rubber component containing a rubber, at least one of said hydrocarbyloxy silane compound selected from the following (a) the general formula (I) and its partial condensation product (Thio) a pneumatic tire characterized by being an epoxy group-containing hydrocarbyloxysilane compound ,

[Where A ¹ Is a monovalent group having a (thio) epoxy group, R ¹ Is a single bond or a divalent inert hydrocarbon group, R ² And R ^Three 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, n is an integer of 0 to 2, ² If there are multiple, multiple R ² Can be the same or different, OR ^Three If there are multiple ORs ^Three May be the same or different, and the molecule does not contain active protons and onium salts. ]

(2) In the rubber composition, the pneumatic tire according to (1) above, which includes (B) 30 to 150 parts by mass of silica with respect to 100 parts by mass of the (A) rubber component.
(3) In the rubber composition, with respect to (A) 100 parts by mass of the rubber component, (C) an inorganic filler other than carbon black and / or silica, The pneumatic tire according to (2) above, which is included at a ratio of 5 to 80 parts by mass so as to be in a range of 180 parts by mass,
(4) The rubber composition according to (2) or (3), wherein the rubber composition further comprises (D) a silane coupling agent in a proportion of 1 to 20% by mass with respect to silica of component (B). tire,
(5) The pneumatic tire according to any one of (1) to (4) above, wherein the rubber composition is disposed in the tread portion.
(6) The modified polybutadiene of the component (A-1) is first modified with a (thio) epoxy group-containing hydrocarbyloxysilane compound at the active end, and further in the presence of a condensation accelerator (thio) epoxy group-containing hydrocarbyloxy The pneumatic tire according to any one of (1) to (5) above, wherein the pneumatic tire is secondarily modified with a silane compound.

(7) The modified polybutadiene of component (A-1) is obtained by first reacting the active terminal with a (thio) epoxy group-containing hydrocarbyloxysilane compound and then reacting with a carboxylic acid partial ester of a polyhydric alcohol. The pneumatic tire according to any one of (1) to (5) above,
(8) The modified polybutadiene of component (A-1) was first modified at the active end with a (thio) epoxy group-containing hydrocarbyloxysilane compound and then introduced into the end in the presence of a condensation accelerator (thio) The pneumatic tire according to any one of the above (1) to (5), which is obtained by condensation reaction of an epoxy group-containing hydrocarbyloxysilane compound residue and an unreacted (thio) epoxy group-containing hydrocarbyloxysilane compound. ,

(9) The pneumatic tire according to (6) above, wherein the modified polybutadiene of component (A-1) is further reacted with a carboxylic acid partial ester of a polyhydric alcohol after the second modification.
(10) The pneumatic tire according to item (8), wherein the modified polybutadiene of component (A-1) is further reacted with a carboxylic acid partial ester of a polyhydric alcohol after the condensation reaction,

(11) The (thio) epoxy group-containing hydrocarbyloxysilane compound contains 2-glycidoxyethyltrimethoxysilane, 2-glycidoxyethyltriethoxysilane, (2-glycidoxyethyl) methyldimethoxysilane, 3-glycidyl Sidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, (3-glycidoxypropyl) methyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4 -Epoxycyclohexyl) ethyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl (methyl) dimethoxysilane, and one or more compounds selected from those obtained by replacing the epoxy group in these compounds with a thioepoxy group (1) to (10) The pneumatic tire according to any Re,

(12) The above (thio) epoxy group-containing hydrocarbyloxysilane compound is one or more compounds selected from 3-glycidoxypropyltrimethoxysilane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane The pneumatic tire according to item (11),

(13) The pneumatic tire according to any one of (7), (9) and (10) above, wherein the carboxylic acid partial ester of the polyhydric alcohol is a monoester, diester or triester of sorbitan fatty acid.

( 14 ) The condensation accelerator is at least one selected from the compounds represented by the following (d) general formula (IV), (e) general formula (V) and (f) general formula (VI), and water. The pneumatic tire according to the above item (6), (8), (9) or (10) ,
(D) Tin oxide having a oxidation number of 2 represented by the general formula (IV) and a carboxylate of 3 to 20 carbon atoms Sn (OCOR ¹⁰ ) ₂ (IV)
[Wherein, R ¹⁰ is an organic group having 2 to 19 carbon atoms, and when there are a plurality of them, they may be the same or different. ]
(E) Tin compound R ¹¹ _r SnA ⁴ _t B ¹ _(4-tr) (V) represented by general formula (V) having an oxidation number of 4
[Wherein, r is an integer of 1 to 3, t is an integer of 1 or 2, and t + r is an integer of 3 or 4. R ¹¹ is an aliphatic hydrocarbon group having 1 to 30 carbon atoms, and B ¹ is a hydroxyl group or a halogen. A ⁴ is (a) an aliphatic carboxylic acid residue having 2 to 30 carbon atoms, (b) a 1,3-dicarbonyl-containing group having 5 to 30 carbon atoms, and (c) a hydrocarbyloxy group having 3 to 30 carbon atoms. And (d) a group selected from a siloxy group having a total of three substitutions (which may be the same or different) with a hydrocarbyl group having 1 to 20 carbon atoms and / or a hydrocarbyloxy group having 1 to 20 carbon atoms, and R ¹¹ may if there are multiple the same or different, may be the same or different if A ⁴ have multiple. ]
(F) Titanium compound of oxidation number 4 represented by general formula (VI) A ⁵ _x TiB ² _(4-x) (VI)
[Wherein x is an integer of 2 or 4. A ⁵ is (i) a hydrocarbyloxy group having 3 to 30 carbon atoms, (b) a siloxy group that is tri-substituted in total with an alkyl group having 1 to 30 carbon atoms and / or a hydrocarbyloxy group having 1 to 20 carbon atoms, When there are a plurality of A ^{5 s,} they may be the same or different. B ² is a 1,3-dicarbonyl-containing group having 5 to 30 carbon atoms, and when there are a plurality of B ² , they may be the same or different. ]
Is to provide.

  ADVANTAGE OF THE INVENTION According to this invention, the pneumatic tire which improved wet-grip performance, braking performance on snow and snow, and dry grip performance simultaneously can be provided.

The pneumatic tire of the present invention comprises a rubber composition containing a rubber component including (A) (A-1) a modified conjugated diene polymer A and (A-2) a low molecular weight styrene-butadiene copolymer rubber. It is preferably disposed in the tire tread portion.
In the rubber composition, the (A-1) modified conjugated diene polymer A contained in the rubber component (A) is a conjugated diene having a cis-1,4-bond content of 75 mol% or more. A polymer obtained by modifying the active terminal of at least a hydrocarbyloxysilane with a compound is used.
The conjugated diene polymer having an active terminal with a cis-1,4-bond content of 75 mol% or more used as an intermediate of the modified conjugated diene polymer A is, for example, a conjugated diene compound of a raw material monomer, It can be produced by polymerization using the following polymerization catalyst by a method such as a solution polymerization method, a gas phase polymerization method or a bulk polymerization method, preferably a solution polymerization method. The polymerization mode may be either a batch type or a continuous type.
Examples of the raw material monomer conjugated diene compound include 1,3-butadiene; isoprene; 1,3-pentadiene; 2,3-dimethylbutadiene; 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.
Further, a small amount of other hydrocarbon monomers may coexist in these conjugated diene compounds, but the conjugated diene compound is preferably 80 mol% or more of the total monomers.

The polymerization catalyst is preferably a combination of at least one compound selected from the following components (x), (y) and (z).
[(X) component]
The rare earth compound selected from the following (x1) to (x4) may be used as it is as an inert organic solvent solution or may be supported on an inert solid.
(X1) a rare earth compound having an oxidation number of 3, a carboxyl group having 2 to 30 carbon atoms, an alkoxy group having 2 to 30 carbon atoms, an aryloxy group having 6 to 30 carbon atoms, and 1,3-di having 5 to 30 carbon atoms One having a total of three ligands freely selected from carbonyl-containing groups, or a Lewis base compound (in particular, free carboxylic acid, free alcohol, 1,3-diketone, cyclic ether, linear ether, Selected from trihydrocarbyl phosphine, trihydrocarbyl phosphite, and the like. Specific examples include neodymium tri-2-ethylhexanoate, a complex compound thereof with acetylacetone, neodymium trineodecanoate, a complex compound thereof with acetylacetone, neodymium tri-n-butoxide, and the like.
(X2) A complex compound of a rare earth trihalide and a Lewis base. For example, there is a THF complex of neodymium trichloride.
(X3) An organic rare earth compound having an oxidation number of 3 in which at least one (substituted) allyl group is directly bonded to a rare earth atom. For example, there is a salt of tetraallyl neodymium and lithium.
(X4) An organic rare earth compound having an oxidation number of 2 or 3 in which at least one (substituted) cyclopentadienyl group is directly bonded to a rare earth atom, or this compound, a trialkylaluminum or a non-coordinating anion and a counter cation It is a reaction product with an ionic compound. An example is dimethylaluminum (μ-dimethyl) bis (pentamethylcyclopentadienyl) samarium.
As the rare earth element of the rare earth compound, lanthanum, neodymium, praseodymium, samarium and gadolinium are preferable, and lanthanum, neodymium and samarium are more preferable.
Among the above components (x), neodymium carboxylates and samarium substituted cyclopentadienyl compounds are preferred.

[(Y) component]
A plurality of organoaluminum compounds selected from the following one can be used at the same time.
(Y1) A trihydrocarbylaluminum compound represented by the formula R ¹² ₃ A1 (wherein R ¹² is a hydrocarbon group having 1 to 30 carbon atoms, which may be the same as or different from each other).
(Y2) Hydrocarbyl aluminum hydride represented by the formula R ¹³ ₂ A1H or R ¹³ A1H ₂ (wherein R ¹³ is a hydrocarbon group having 1 to 30 carbon atoms, which may be the same or different from each other).
(Y3) A hydrocarbylaluminoxane compound having a hydrocarbon group having 1 to 30 carbon atoms.
Examples of the component (y) include trialkylaluminum, dialkylaluminum hydride, alkylaluminum dihydride, and alkylaluminoxane. These compounds may be used as a mixture. Among the components (y), a combination of an aluminoxane and another organoaluminum compound is preferable.
[(Z) component]
Although it is a compound selected from the following ones, it is not always necessary when (x) contains a halogen or a non-coordinating anion and (y) contains an aluminoxane.
(Z1) An inorganic or organic compound of an element belonging to Group II, III, or IV, or a complex compound of these with a Lewis base, having a hydrolyzable halogen. For example, alkyl aluminum dichloride, dialkyl aluminum chloride, silicon tetrachloride, tin tetrachloride, a complex of zinc chloride and a Lewis base such as alcohol, a complex of magnesium chloride and a Lewis base such as alcohol, or the like.
(Z2) An organic halide having a structure selected from at least one tertiary alkyl halide, benzyl halide, and allyl halide. For example, benzyl chloride, t-butyl chloride, benzyl bromide, t-butyl bromide and the like.
(Z3) A zinc halide or a complex compound of this with a Lewis base.
(Z4) An ionic compound comprising a non-coordinating anion and a counter cation. For example, triphenylcarbonium tetrakis (pentafluorophenyl) borate is preferably used.

For the preparation of the catalyst, in addition to the components (x), (y), and (z), the same conjugated diene compound and / or non-conjugated diene monomer as the polymerization monomer is used in combination as necessary. May be.
Further, a part or all of the component (x) or the component (z) may be supported on an inert solid, and in this case, it can be carried out by so-called gas phase polymerization.
Although the usage-amount of the said catalyst can be set suitably, normally (x) component is about 0.001-0.5 millimoles per 100g of monomers. Moreover, (y) component / (x) component is about 5-1000 and (z) component / (x) component is about 0.5-10 by molar ratio.
Examples of the solvent used in the case of solution polymerization include organic solvents inert to the reaction, for example, hydrocarbon solvents such as aliphatic, alicyclic, and aromatic hydrocarbon compounds. Specifically, those having 3 to 8 carbon atoms are preferred, such as propane, n-butane, isobutane, n-pentane, isopentane, n-hexane, cyclohexane, propene, 1-butene, isobutene, trans-2-butene, Examples thereof include cis-2-butene, 1-pentene, 2-pentene, 1-hexene, 2-hexene, benzene, toluene, xylene, and ethylbenzene. These may be used alone or in combination of two or more.
The temperature in this 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 will depend on the particular material being polymerized, the polymerization medium used and the polymerization temperature, but higher pressures can be used if desired, and such a pressure can be used with a gas inert to the polymerization reaction. It can be obtained by an appropriate method such as pressurization.
In this polymerization, it is desirable that all raw materials involved in the polymerization, such as a catalyst, a solvent, a monomer, and the like, from which reaction inhibitors such as water, oxygen, carbon dioxide, and protic compounds are substantially removed are used.

The modified conjugated diene polymer A is the activity of the conjugated diene polymer (intermediate polymer) having an active terminal having a cis-1,4-bond content of 75 mol% or more thus obtained. The terminal is modified with at least a hydrocarbyloxysilane compound, and there are five modes as shown below.
First, the first embodiment is a modified conjugated diene system in which the active terminal of the intermediate polymer is first modified with a hydrocarbyloxysilane compound and then secondarily modified with a hydrocarbyloxysilane compound in the presence of a condensation accelerator. It is a polymer.
The second aspect is a modified conjugated diene polymer obtained by first reacting the active terminal of the intermediate polymer with a hydrocarbyloxysilane compound and then reacting with a carboxylic acid partial ester of a polyhydric alcohol.
In a third aspect, the hydrocarbyloxysilane compound residue and the unreacted hydrocarbyloxysilane introduced into the terminal after the primary modification of the active end of the intermediate polymer with a hydrocarbyloxysilane compound and further in the presence of a condensation accelerator It is a modified conjugated diene polymer obtained by condensation reaction with a compound.
A fourth aspect is a modified conjugated diene polymer obtained by reacting with a carboxylic acid partial ester of a polyhydric alcohol after the secondary modification in the first aspect of the previous period.
The fifth aspect is a modified conjugated diene polymer obtained by further reacting with a carboxylic acid partial ester of a polyhydric alcohol after the condensation reaction in the third aspect.

In the primary modification reaction in each of the above-described embodiments, the intermediate polymer used preferably has at least 10% of polymer chains having a living property.
The hydrocarbyloxysilane compound used for modification is at least one selected from the following (a) general formula (I), (b) general formula (II), (c) general formula (III) and partial condensates thereof. Mention may be made of certain compounds.
[(A) Hydrocarbyloxysilane compound]
This hydrocarbyloxysilane compound has the general formula (I)

[Wherein A ¹ is (thio) epoxy, (thio) isocyanate, (thio) ketone, (thio) aldehyde, imine, amide, isocyanuric acid trihydrocarbyl ester, (thio) carboxylic acid ester, (thio) carboxylic acid A monovalent group having at least one functional group selected from metal salts, carboxylic acid anhydrides, carboxylic acid halides and carbonic acid dihydrocarbyl esters, R ¹ is a single bond or a divalent inert hydrocarbon group , R ² and R ³ each independently represent a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and n is an integer of 0 to 2 , and the case where R ² is plural, R ² may be the same or different, if the OR ³ there are a plurality, the plurality of OR ³ may be the same or different, and in the molecule active proton And onium salts are not included. ]
And / or a partial condensate thereof.

In the general formula (1), among the functional groups in A ¹ , imine includes ketimine, aldimine, and amidine, and (thio) carboxylic acid ester includes unsaturated carboxylic acid ester such as acrylate and methacrylate. Examples of the metal of the metal salt of (thio) carboxylic acid include alkali metals, alkaline earth metals, Al, Sn, and Zn.
Preferred examples of the divalent inert hydrocarbon group in R ¹ include an alkylene group having 1 to 20 carbon atoms. The alkylene group may be linear, branched or cyclic, but is particularly preferably linear. 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 ² and R ³ 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 methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl. Group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, decyl group, dodecyl group, cyclopentyl group, cyclohexyl group, vinyl group, propenyl group, allyl group, hexenyl group, octenyl group, 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. Further, 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.
n is an integer of 0 to 2, but 0 is preferable, and it is necessary that this molecule has no active proton and onium salt.

Examples of the hydrocarbyloxysilane compound represented by the general formula (I) include (thio) epoxy group-containing hydrocarbyloxysilane compounds such as 2-glycidoxyethyltrimethoxysilane, 2-glycidoxyethyltriethoxysilane, (2-glycidoxyethyl) methyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, (3-glycidoxypropyl) methyldimethoxysilane, 2- (3,4) - epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-d Po carboxymethyl) ethyl triethoxysilane, an epoxy group in the 2- (3,4-epoxycyclohexyl) ethyl (methyl) dimethoxysilane and compounds thereof Place on thioepoxy group There may be mentioned preferably those were example, among these, in particular 3-glycidoxypropyltrimethoxysilane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane are preferable.
Further, as imine group-containing hydrocarbyloxycyan compounds, N- (1,3-dimethylbutylidene) -3- (triethoxysilyl) -1-propanamine, N- (1-methylethylidene) -3- (triethoxy Silyl) -1-propanamine, N-ethylidene-3- (triethoxysilyl) -1-propanamine, N- (1-methylpropylidene) -3- (triethoxysilyl) -1-propanamine, N- (4-N, N-dimethylaminobenzylidene) -3- (triethoxysilyl) -1-propanamine, N- (cyclohexylidene) -3- (triethoxysilyl) -1-propanamine and their triethoxy Trimethoxysilyl compounds corresponding to silyl compounds, methyldiethoxysilyl compounds, ethyldiethoxysilyl compounds, Preferred examples include tildimethoxysilyl compounds and ethyldimethoxysilyl compounds, among which N- (1-methylpropylidene) -3- (triethoxysilyl) -1-propanamine and N- ( 1,3-dimethylbutylidene) -3- (triethoxysilyl) -1-propanamine is preferred.

Furthermore, the following can be mentioned as another hydrocarbyloxy compound. That is, as imine (amidine) group-containing compounds, 1- [3- (triethoxysilyl) propyl] -4,5-dihydroimidazole, 1- [3- (trimethoxysilyl) propyl] -4,5-dihydro Examples thereof include imidazole, 3- [10- (triethoxysilyl) decyl] -4-oxazoline, and among these, 3- (1-hexamethyleneimino) propyl (triethoxy) silane, (1-hexa Methyleneimino) methyl (trimethoxy) silane, 1- [3- (triethoxysilyl) propyl] -4,5-dihydroimidazole and 1- [3- (trimethoxysilyl) propyl] -4,5-dihydroimidazole are preferred Can be mentioned. 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 them, N- (3-triethoxysilylpropyl) -4,5-dihydroimidazole is preferable.
Examples of the carboxylic acid ester group-containing compound include 3-methacryloyloxypropyltriethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, and 3-methacryloyloxypropyltriisosilane. Examples thereof include propoxysilane, among which 3-methacryloyloxypropyltrimethoxysilane is preferable. Furthermore, examples of the isocyanate group-containing compound include 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-isocyanatopropylmethyldiethoxysilane, and 3-isocyanatopropyltriisopropoxysilane. Of these, 3-isocyanatopropyltriethoxysilane is preferred. Examples of the carboxylic acid anhydride-containing compound include 3-triethoxysilylpropyl succinic anhydride, 3-trimethoxysilylpropyl succinic anhydride, 3-methyldiethoxysilylpropyl succinic anhydride, and the like. Of these, 3-triethoxysilylpropyl succinic anhydride is preferred.

One of these hydrocarbyloxysilane compounds may be used alone, or two or more thereof may be used in combination. Moreover, the partial condensate of the said hydrocarbyl oxysilane compound can also be used.
[(B) Hydrocarbyloxysilane compound]
This hydrocarbyloxysilane compound has the general formula (II)

Wherein, A ² is a cyclic tertiary amine, acyclic tertiary amines, pyridine, sulfides, monovalent group having at least one functional group selected from among the multi-sulfides and nitriles, R ⁴ is a single bond Or a divalent inert hydrocarbon group, R ⁵ and R ⁶ are each independently a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms. indicates, m is an integer from 0 to 2, if R ⁵ there are a plurality, the plurality of R ⁵ may be the same or different, if OR ⁶ have multiple, even if a plurality of OR ⁶ may be the same or different Well, the molecule does not contain active protons and onium salts. ]
And / or a partial condensate thereof.
The hydrocarbyloxysilane compound represented by the general formula (II) and / or a partial condensate thereof is not directly reacted with the active end and remains in the reaction system as unreacted, and thus introduced into the active end. Is consumed for condensation with the hydrocarbyloxysilane compound residue.

In the general formula (II), the acyclic tertiary amine in A ² contains an N, N- (disubstituted) aromatic amine such as N, N- (disubstituted) aniline, and is also a cyclic tertiary amine. The amine can contain a (thio) ether as part of the ring. Divalent inactive hydrocarbon group among R ^4, the R ⁵ and R ⁶ are as described for R ^1, R ² and R ³ in each of the general formula (I). It is necessary that this molecule does not have active protons and onium salts.
Examples of the hydrocarbyloxysilane compound represented by the general formula (II) include 3-dimethylaminopropyl (triethoxy) silane and 3-dimethylaminopropyl (trimethoxy) silane as acyclic tertiary amine group-containing hydrocarbyloxysilane compounds. , 3-diethylaminopropyl (triethoxy) silane, 3-diethylaminopropyl (trimethoxy) silane, 2-dimethylaminoethyl (triethoxy) silane, 2-dimethylaminoethyl (trimethoxy) silane, 3-dimethylaminopropyl (diethoxy) methylsilane, 3, -Dibutylaminopropyl (triethoxy) silane etc. can be mentioned, among these, 3-diethylaminopropyl (triethoxy) silane and 3-dimethylaminopropyl (triethoxy) Silanes are preferred.
Further, as the cyclic tertiary amine group-containing hydrocarbyloxysilane compound, 3- (1-hexamethyleneimino) propyl (triethoxy) silane, 3- (1-hexamethyleneimino) 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-dodecamethyleneimino) Propyl (triethoxy) Run, 3- (1-hexamethyleneimino) propyl (diethoxy) methylsilane, 3- (1-hexamethyleneimino) can be preferably exemplified propyl (diethoxy) ethylsilane. In particular, 3- (1-hexamethyleneimino) propyl (triethoxy) silane is preferred.
Furthermore, examples of other hydrocarbyloxysilane compounds include 2- (trimethoxysilylethyl) pyridine, 2- (triethoxysilylethyl) pyridine, 4-ethylpyridine and the like.

One of these hydrocarbyloxysilane compounds may be used alone, or two or more thereof may be used in combination. Moreover, the partial condensate of these hydrocarbyl oxysilane compounds can also be used.
[(C) Hydrocarbyloxysilane compound]
This hydrocarbyloxysilane compound has the general formula (III)

[Wherein, A ³ represents alcohol, thiol, primary amine and onium salt thereof, cyclic secondary amine and onium salt thereof, acyclic secondary amine and onium salt thereof, onium salt of cyclic tertiary amine, acyclic tertiary amine An onium salt of an amine, a group having an aryl or arylalkyl Sn bond, a monovalent group having at least one functional group selected from sulfonyl, sulfinyl and nitrile, R ⁷ is a single bond or a divalent inert hydrocarbon group, R ⁸ and R ⁹ each independently represent a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, q is an integer of 0 to 2 There, if R ⁸ is plural, R ⁸ may be the same or different, if the OR ⁹ there are a plurality, the plurality of OR ⁹ may be the same or different. ]
And / or a partial condensate.

In the general formula (III), the primary amine in A ³ includes aromatic amines such as aniline, and the acyclic secondary amine is N- (monosubstituted) aromatic such as N- (monosubstituted) aniline. Includes amines. Further, onium salts of acyclic tertiary amines include onium salts of N, N- (disubstituted) aromatic amines such as N, N- (disubstituted) aniline. Also. In the case of a cyclic secondary amine or a cyclic tertiary amine, (thio) ether can be contained as a part of the ring. Divalent inactive hydrocarbon group out of R ^7, the R ⁸ and R ⁹ are as described for R ^1, R ² and R ³ in each of the general formula (I).
Examples of the hydrocarbyloxysilane compound represented by the general formula (III) include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, hydroxymethyltrimethoxysilane, hydroxymethyltriethoxysilane, mercaptomethyltrimethoxy. Silane, mercaptomethyltriethoxysilane, aminophenyltrimethoxysilane, aminophenyltriethoxysilane, 3- (N-methylamino) propyltrimethoxysilane, 3- (N-methylamino) propyltriethoxysilane, octadecyldimethyl (3 -Trimethylsilylpropyl) ammonium chloride, octadecyldimethyl (3-triethylsilylpropyl) ammonium chloride, cyanomethyltrimethoxysilane, cyanomethyltrieth Shishiran, it can be exemplified sulfonyl methyltrimethoxysilane, sulfonyl methyltriethoxysilane, sulfinyl methyltrimethoxysilane, a sulfinyl methyl triethoxysilane.

One of these hydrocarbyloxysilane compounds may be used alone, or two or more thereof may be used in combination. Moreover, the partial condensate of the said hydrocarbyl oxysilane compound can also be used.
The partial condensate of the hydrocarbyloxysilane compound represented by the general formulas (I), (II), and (III) means that a part (not all) of the SiOR of the hydrocarbyloxysilane compound is condensed. This refers to SiOSi bonded.
In the present invention, in the case of the first aspect, the third aspect, the fourth aspect, and the fifth aspect, the reaction with the remaining or newly added hydrocarbyloxysilane compound in the presence of a condensation accelerator. First, an intermediate polymer having an active terminal is reacted with a substantially stoichiometric amount of a hydrocarbyloxysilane compound added to the reaction system, so that substantially all of the terminals have hydrocarbyloxysilyl groups. By introducing (primary modification) and reacting the hydrocarbyloxysilyl compound with the hydrocarbyloxysilyl group introduced above, more hydrocarbyloxysilane compound residues than the equivalent amount are introduced into the active terminal. For this reason, since a further effect is acquired with respect to low heat generation property and workability, these aspects are preferable to the second aspect.

  In the present invention, when the hydrocarbyloxysilane compound is an alkoxysilyl compound, the condensation reaction between alkoxysilyl groups in the first aspect, the third aspect, the fourth aspect, and the fifth aspect is (residual or It preferably occurs between the newly added free alkoxysilane and the alkoxysilyl group at the end of the polymer, and in some cases, preferably occurs between the alkoxysilyl groups at the end of the polymer. is necessary. Therefore, when an alkoxysilane compound is newly added, it is preferable from the viewpoint of efficiency that the hydrolyzability of the alkoxysilyl group does not exceed the hydrolyzability of the alkoxysilyl group at the end of the polymer. For example, alkoxysilane I uses a highly hydrolyzable trimethoxysilyl group-containing compound, and newly added alkoxysilane II contains an alkoxysilyl group (for example, triethoxysilyl group) that is less hydrolyzable than this. Combinations using compounds are preferred. Conversely, for example, it is within the scope of the present invention that alkoxysilane I contains a triethoxysilyl group and II contains a trimethoxysilyl group, but is not preferable from the viewpoint of reaction efficiency.

For the modification reaction in the present invention, either a solution reaction or a solid phase reaction can be used, but a solution reaction (a solution containing an unreacted monomer used during polymerization may be suitable). Moreover, there is no restriction | limiting in particular about the form of this modification | denaturation reaction, You may carry out using a batch type reactor, You may carry out by a continuous type using apparatuses, such as a multistage continuous type reactor and an in-line mixer. In addition, it is important to carry out the modification reaction after completion of the polymerization reaction and before performing various operations necessary for solvent removal treatment, water treatment, heat treatment, polymer isolation, and the like.
As the temperature of the modification reaction, the polymerization temperature of the conjugated diene polymer can be used as it is. Specifically, a preferable range is 20 to 100 ° C. If the temperature is low, the viscosity of the polymer tends to increase, and if the temperature is high, the polymerization active terminal tends to be deactivated.
Next, in order to accelerate the secondary modification, it is preferably performed in the presence of a condensation accelerator. As this condensation accelerator, a combination of a metal compound generally known as a curing catalyst for alkoxy condensation curable room temperature crosslinking (RTV) silicone and water can be used. For example, a combination of tin carboxylate and / or titanium alkoxide and water can be preferably exemplified. There is no particular limitation on the method of charging the condensation accelerator into the reaction system. A solution of an organic solvent compatible with water such as alcohol may be used, or water may be directly injected, dispersed, or dissolved in the hydrocarbon solution using various chemical engineering techniques.

As such a condensation accelerator, at least one selected from the compounds represented by the following (d) general formula (IV), (e) general formula (V) and (f) general formula (VI): It is preferable that it consists of water.
(D) a carboxylic acid salt of 3 to 20 carbon atoms of tin of oxidation number 2 represented by the general formula (IV):
Sn (OCOR ¹⁰ ) ₂ (IV)
[Wherein, R ¹⁰ is an organic group having 2 to 19 carbon atoms, and when there are a plurality of them, they may be the same or different. ]
(E) Tin compound having oxidation number 4 represented by general formula (V):
R ¹¹ _r SnA ⁴ _t B ¹ _(4-tr) (V)
[Wherein, r is an integer of 1 to 3, t is an integer of 1 or 2, and t + r is an integer of 3 or 4. R ¹¹ is an aliphatic hydrocarbon group having 1 to 30 carbon atoms, and B ¹ is a hydroxyl group or a halogen. A ⁴ is (a) an aliphatic carboxylic acid residue having 2 to 30 carbon atoms, (b) a 1,3-dicarbonyl-containing group having 5 to 30 carbon atoms, and (c) a hydrocarbyloxy group having 3 to 30 carbon atoms. And (d) a group selected from a siloxy group having a total of three substitutions (which may be the same or different) with a hydrocarbyl group having 1 to 20 carbon atoms and / or a hydrocarbyloxy group having 1 to 20 carbon atoms, and R ¹¹ may if there are multiple the same or different, may be the same or different if A ⁴ have multiple. ]
(F) Titanium compound having an oxidation number of 4 represented by the general formula (VI):
A ⁵ _x TiB ² _(4-x) (VI)
[Wherein x is an integer of 2 or 4. A ⁵ is (i) a hydrocarbyloxy group having 3 to 30 carbon atoms, (b) a siloxy group that is tri-substituted in total with an alkyl group having 1 to 30 carbon atoms and / or a hydrocarbyloxy group having 1 to 20 carbon atoms, When there are a plurality of A ^{5 s,} they may be the same or different. B ² is a 1,3-dicarbonyl-containing group having 5 to 30 carbon atoms, and when there are a plurality of B ² , they may be the same or different. ]

Examples of the carboxylic acid salt of tin having an oxidation number of 2 represented by the general formula (IV) in (d) include bis (2-ethylhexanoic acid) tin, tin dioleate, tin dilaurate, and the like (f). Among the tin compounds of oxidation number 4 represented by the general formula (V), tetravalent dihydrocarbyltin dicarboxylate (bis (hydrocarbyldicarboxylic acid) salt) And (b) mono-carboxylate hydroxide having a 1,3-dicarbonyl-containing group having 5 to 30 carbon atoms such as bis (1,3-diketonate), As those having a hydrocarbyloxy group having 3 to 30 carbon atoms, the alkoxy halide is (d) a total of three substitutions (identical) with a hydrocarbyl group having 1 to 20 carbon atoms and / or a hydrocarbyloxy group having 1 to 20 carbon atoms. And those having a siloxy group which may be different from each other include alkoxy (trihydrocarbylsiloxide), alkoxy (dihydrocarbylalkoxysiloxide), bis (trihydrocarbylsiloxide), bis (dihydrocarbylalkoxysiloxide) Etc. are preferable. The hydrocarbon group condensed with tin preferably has 4 or more carbon atoms, and more preferably has 4 to 8 carbon atoms.
Further, as the titanium compound having an oxidation number of 4 represented by the general formula (VI) of the above (f), a tetraalkoxide or tetrakis (trihydrocarbyloxysiloxide) of titanium having an oxidation number of 4 or diisopropoxybis (acetyl) Dialkoxybis (1,3-diketonate) titanium (titanium chelate compound) such as acetonate) titanium.

The water in the condensation accelerator is preferably used in the form of a simple substance, a solution of alcohol or the like, or a dispersed micelle in a hydrocarbon solvent, and if necessary, such as adsorbed water on the solid surface or hydrated water of hydrate. The water potentially contained in the compound capable of releasing water in the reaction system can also be used effectively.
The metal compound and water forming the condensation accelerator may be added separately to the reaction system or mixed immediately before use as a mixture, but long-term storage of the mixture is preferable because it causes decomposition of the metal compound. Absent.
The amount of the condensation accelerator used is preferably such that the molar ratio of the metal of the metal compound and the water effective for the reaction to the total amount of hydrocarbyloxysilyl groups present in the reaction system is 0.1 or more. Although the upper limit varies depending on the purpose and reaction conditions, it is preferable that there is effective water having a molar ratio of about 0.5 to 3 with respect to the total amount of hydrocarbyloxysilyl groups condensed at the polymer terminal before the condensation treatment. The molar ratio of the metal of the metal compound to water effective for the reaction varies depending on the reaction conditions required, but is preferably about 1: 0.5 to 1:20.

In the present invention, in the second, fourth and fifth aspects of the modified conjugated diene polymer A used as the component (A-1), a carboxylic acid partial ester of a polyhydric alcohol is polymerized. An operation of reacting with a group derived from a hydrocarbyloxysilane compound introduced at the terminal and stabilizing the group is performed.
Here, the carboxylic acid partial ester of a polyhydric alcohol is an ester of a polyhydric alcohol and a carboxylic acid and means a partial ester having one or more hydroxyl groups. Specifically, an ester of a saccharide having 4 or more carbon atoms or a modified saccharide and a fatty acid is preferably used. This ester is more preferably (1) a fatty acid partial ester of a polyhydric alcohol, particularly a partial ester of a saturated higher fatty acid or unsaturated higher fatty acid having 10 to 20 carbon atoms and a polyhydric alcohol (monoester, diester, triester). And (2) ester compounds in which 1 to 3 partial esters of a polyvalent carboxylic acid and a higher alcohol are bonded to the polyhydric alcohol.

The polyhydric alcohol used as the raw material for the partial ester is preferably a saccharide having 5 or 6 carbon atoms having at least three hydroxyl groups (which may be hydrogenated or not hydrogenated), glycol, A polyhydroxy compound or the like is used. The raw fatty acid is preferably a saturated or unsaturated fatty acid having 10 to 20 carbon atoms, and for example, stearic acid, lauric acid, and palmitic acid are used.
Among the fatty acid partial esters of polyhydric alcohols, sorbitan fatty acid esters are preferred, and specifically, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan tristearate, sorbitan monooleate and And sorbitan trioleate.
Commercially available products include “SPAN60” (sorbitan stearate), “SPAN80” (sorbitan monooleate), “SPAN85” (sorbitan trioleate) and the like as trademarks of ICI.
The amount of the partial ester added is preferably about 0.2 to 10 mol, particularly 1 to 10 mol, relative to 1 mol of the hydrocarbyloxysilyl group imparted to the intermediate polymer.

The modified conjugated diene polymer A of the component (A-1) thus produced has a large effect of improving the dispersion with respect to the reinforcing filler, particularly silica, and the rigidity of the tire tread portion in the region of 0 ° C. or less. Although the reduction is realized, it has the effect of suppressing the reduction in the rigidity of the tire tread in the region of 20 ° C. or higher. Such an effect is more effectively exhibited when the modified conjugated diene polymer is a modified polybutadiene having a cis-1,4-bond amount of 75 mol% or more.
On the other hand, in the rubber composition, the low molecular weight styrene-butadiene copolymer rubber of the component (A-2) used in combination with the modified conjugated diene polymer A does not increase the rigidity on the wet road surface. It has the effect of improving braking performance. In order to exert such an action effectively, it is necessary that the weight average molecular weight of the low molecular weight styrene-butadiene copolymer rubber of the component (A-2) is in the range of 20,000 to 150,000, Preferably it is 30,000-120,000, More preferably, it is 50,000-100,000. The weight average molecular weight is a value in terms of polystyrene measured by a gel permeation chromatography method (GPC method).
A rubber composition comprising such a modified conjugated diene polymer A as the component (A-1) and a low molecular weight styrene-butadiene copolymer rubber as the component (A-2) is used as a tire tread portion. Even if the braking performance is improved on a dry road surface or a wet road surface, the braking performance on snow and icy road surfaces is not reduced.
In order to effectively exhibit the effect, in the present invention, as the rubber component (A) in the rubber composition, the modified conjugated diene polymer A of the component (A-1) is preferably 5 to 50% by mass, preferably Is contained in a proportion of 10 to 40% by mass, more preferably 15 to 30% by mass, and the low molecular weight styrene-butadiene copolymer rubber of component (A-2) is 4 to 45% by mass, preferably 5 to 25% by mass. %, More preferably 10 to 20% by mass.

In the rubber composition, (A) the rubber component is further combined with the components (A-1) and (A-2), and (A-3) natural rubber and / or diene synthetic rubber [(A-1 ) And (other than (A-2)].
Here, as diene type synthetic rubber other than (A-1) and (A-2), for example, polyisoprene synthetic rubber (IR), polybutadiene rubber (BR), high molecular weight styrene-butadiene rubber (SBR), acrylonitrile butadiene Examples thereof include rubber (NBR), chloroprene rubber (CR), and butyl rubber (IIR). This natural rubber or diene synthetic rubber of component (A-3) may be used alone or in combination of two or more.
The rubber component (A) can contain ethylene-propylene copolymer rubber (EPR, EPDM), and a part of the rubber component is a polyfunctional type, for example, a modifier such as tin tetrachloride. By using it, it may have a branched structure.

In the rubber composition, (B) silica can be included as a reinforcing filler. The silica is not particularly limited, and can be arbitrarily selected from those conventionally used as reinforcing fillers for rubber.
Examples of the silica include wet silica (hydrous silicic acid), dry silica (anhydrous silicic acid), calcium silicate, aluminum silicate, and the like. Wet silica that is noticeable is preferred. The wet silica preferably has a nitrogen adsorption specific surface area (N ₂ SA) by the BET method of 140 to 280 m ² / g from the viewpoint of balance between reinforcement, workability, wet grip properties, and wear resistance, It is more preferable that it is 170-250 m < ² > / g. Suitable wet silica includes, for example, AQ, VN3, LP, NA, etc. manufactured by Tosoh Silica Co., Ltd. and Ultrazil VN3 (N ₂ SA: 210 m ² / g) manufactured by Degussa.
The content of the silica is preferably 30 to 150 parts by mass with respect to 100 parts by mass of the rubber component as the component (A) from the viewpoint of obtaining a rubber composition having desired performance and good workability. Preferably, it is selected in the range of 30 to 80 parts by mass.

In the rubber composition, an inorganic filler other than (C) carbon black and / or silica can be further contained as a reinforcing filler together with silica as the component (B). The carbon black is not particularly limited, and for example, SRF, GPF, FEF, HAF, ISAF, SAF and the like are used, iodine adsorption amount (IA) is 60 mg / g or more, and dibutyl phthalate oil absorption amount (DBP) is 80 ml / 100 g or more of carbon black is preferred. By using carbon black, the effect of improving grip performance and fracture resistance is increased, but HAF, ISAF, and SAF, which are excellent in wear resistance, are particularly preferable.
On the other hand, examples of the inorganic filler other than silica include compounds represented by the following general formula (VII).

mM ¹ · xSiOy · zH ₂ O (VII)
(In the formula, M ¹ represents a metal selected from the group consisting of aluminum, magnesium, titanium, calcium, and zirconium, an oxide or hydroxide of these metals, and a hydrate thereof, or carbonic acid of these metals. And m, x, y and z are each an integer of 1 to 5, an integer of 0 to 10, an integer of 2 to 5, and an integer of 0 to 10. In the case where x and z are both 0, the inorganic compound is at least one metal, metal oxide or metal hydroxide selected from aluminum, magnesium, titanium, calcium and zirconium.)
Examples of the inorganic filler represented by the above formula include alumina (Al ₂ O ₃ ) such as γ-alumina and α-alumina, alumina monohydrate (Al ₂ O ₃ .H ₂ O) such as boehmite and diaspore, gibbsite, Aluminum hydroxide such as bayerite [Al (OH) ₃ ], aluminum carbonate [Al ₂ (CO ₃ ) ₂ ], magnesium hydroxide [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 · 2H 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 ), 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 ], crystalline aluminosilicates containing hydrogen, alkali metals or alkaline earth metals that correct the charge, such as various zeolites, can be used. In addition, it is preferable that M ¹ in the general formula (VII) is at least one selected from aluminum metal, aluminum oxide or hydroxide, hydrates thereof, and aluminum carbonate.
These inorganic fillers represented by the above formula may be used alone or in combination of two or more.

In the rubber composition, the inorganic filler other than the carbon black and / or silica of the component (C) is filled other than carbon black and / or silica from the viewpoint of reinforcement and dispersibility in the rubber composition. 5 to 80 parts by mass so that the total amount of the agent and silica is usually in the range of 35 to 180 parts by mass, preferably 45 to 120 parts by mass, with respect to 100 parts by mass of the rubber component (A). It is good to make it contain in a ratio, preferably 10 to 50 parts by mass.
In the rubber composition, (D) a silane cup agent can be contained for the purpose of further improving the performance of silica as the component (B).

  Examples of the silane coupling agent include bis (3-triethoxysilylpropyl) tetrasulfide, bis (3-triethoxysilylpropyl) trisulfide, bis (3-triethoxysilylpropyl) disulfide, and bis (2-triethoxy). Silylethyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyl Trimethoxysilane, 2-mercaptoethyltriethoxysilane, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl-N, N-dimethylthiocarb Moyl tetrasulfide, 2-triethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilylpropylbenzothiazolyl tetrasulfide, 3-triethoxysilylpropylbenzoyl tetrasulfide, 3-triethoxysilyl Propyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, bis (3-diethoxymethylsilylpropyl) tetrasulfide, 3-mercaptopropyldimethoxymethylsilane, dimethoxymethylsilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide , Dimethoxymethylsilylpropylbenzothiazolyl tetrasulfide, and the like. Among these, bis (3-trie Silyl propyl) polysulfide and 3-trimethoxysilylpropyl benzothiazyl tetrasulfide are preferable. One of these silane coupling agents may be used alone, or two or more thereof may be used in combination.

  In the rubber composition, since a modified polymer in which a functional group having high affinity with silica is introduced at the molecular end is used as the rubber component, the blending amount of the silane coupling agent is more than usual. Can be reduced. The blending amount of the preferred silane coupling agent varies depending on the type of the silane coupling agent, but is usually selected in the range of 1 to 20% by mass with respect to silica. If the amount is small, the effect as a coupling agent is hardly exhibited, and if it is large, the rubber component may be gelled. From the viewpoint of the effect as a coupling agent and the prevention of gelation, the preferred amount of the silane coupling agent is in the range of 5 to 15% by mass.

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, vulcanization accelerators, process oils, anti-aging agents, and scorch preventions are used. An agent, zinc white, stearic acid and the like can be contained.
As said vulcanizing agent, sulfur etc. are mentioned, The usage-amount is 0.1-10.0 mass parts as a sulfur content with respect to 100 mass parts of rubber components, 0.5-5.0 mass parts is preferable. Is more preferable.
The vulcanization accelerator that can be used in the present invention is not particularly limited, and examples thereof include M (2-mercaptobenzothiazole), DM (dibenzothiazyl disulfide), and CZ (N-cyclohexyl-2-benzothiazyl). Sulfenamide) and other guanidine vulcanization accelerators such as DPG (diphenylguanidine) can be used, and the amount used is 0.1-5. 0 mass part is preferable, More preferably, it is 0.2-3.0 mass part.
Examples of the process oil that can be used in the rubber composition include paraffinic, naphthenic, and aromatic oils. Aromatics are used for applications that emphasize tensile strength and wear resistance, and naphthenic or paraffinic systems are used for applications that emphasize hysteresis loss and low-temperature characteristics. The amount used is preferably 0 to 100 parts by mass with respect to 100 parts by mass of the rubber component, and if it is 100 parts by mass or less, the tensile strength and low heat build-up of the vulcanized rubber will be good.

The rubber composition is obtained by kneading using a kneading machine such as a Banbury mixer, a roll, an internal mixer, etc., vulcanized after molding, and used for a pneumatic tire, preferably a tire tread. .
The pneumatic tire of the present invention is produced by a usual method using the above rubber composition. That is, if necessary, the rubber composition containing various chemicals as described above is processed into a tire tread at an unvulcanized stage, and pasted and molded by a normal method on a tire molding machine, and the raw tire Is formed. The green tire is heated and pressed in a vulcanizer to obtain a tire.
The pneumatic tire of the present invention thus obtained has good braking performance on wet road surfaces, braking performance on snow and icy road surfaces, and braking performance on dry road surfaces.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
In addition, the performance of the pneumatic tire obtained in each example was evaluated according to the following procedure by attaching test tires using the same rubber composition to all four 1800 cc passenger cars.
(1) Wet grip performance The test tire was mounted on an actual vehicle, and the braking distance on a wet road surface with a water depth of 2 mm was measured. The evaluation results are shown as an index with the reciprocal of the braking distance of the tire of Comparative Example 1 being 100. The larger the index value, the better the wet grip performance.
(2) Brake performance on ice and snow The snow / ice road surface braking distance on the winter test course was determined under the conditions of an outside air temperature of −4 ° C. and 40 km / hr, and the reciprocal of the braking distance of Comparative Example 1 was displayed as an index. The larger the index value, the better the braking performance on ice and snow.
(3) Dry grip performance The test tire was mounted on an actual vehicle, and the braking distance on the dry road surface was measured. The evaluation results are shown as an index with the reciprocal of the braking distance of the tire of Comparative Example 1 being 100. The larger the index value, the better the dry grip performance.

Production Example 1 Production of Modified Polybutadiene (1) Preparation of Catalyst 7.11 g of cyclohexane solution of butadiene (15.2% by mass) in the following order in a glass bottle with a rubber brace volume of 100 ml, which was dried and substituted with nitrogen. 0.59 ml of a cyclohexane solution of neodymium neodecanoate (0.56 mol / liter), 10.32 ml of a toluene solution of methylaluminoxane MAO (PMAO manufactured by Tosoh Akzo) (aluminum concentration: 3.23 mol / liter), 7.77 ml of hexane solution (0.90 mol / liter) of diisobutylaluminum hydride (manufactured by Kanto Chemical Co., Inc.) was added, and after aging at room temperature for 2 minutes, hexane solution of chlorinated diethylaluminum (manufactured by Kanto Chemical Co., Ltd.) (0 .95 mol / liter) 1.45 ml added With warm, it was aged occasional stirring for 15 minutes. The concentration of neodymium in the catalyst solution thus obtained was 0.011 mol / liter.
(2) Production of intermediate polymer A glass bottle with a rubber stopper with a volume of about 900 milliliters was dried and purged with nitrogen, and then a dry purified cyclohexane solution of butadiene and a dry cyclohexane were added to each, and a cyclohexane solution containing 12.5% by weight of butadiene. 400 g was charged. Next, 2.28 ml (0.025 mmol in terms of neodymium) of the catalyst solution prepared in the above (1) was added, and polymerization was carried out in a 50 ° C. warm water bath for 1.0 hour to produce an intermediate polymer. The microstructure of the obtained polymer had a cis-1,4-bond content of 95.5%, a trans-1,4-bond content of 3.9%, and a vinyl bond content of 0.6%. These microstructures were determined by Fourier transform infrared spectroscopy. Details of this Fourier transform infrared spectroscopy are described in, for example, Patent Document 2.
(3) Modification Treatment A hexane solution having a 3-glycidoxypropyltrimethoxysilane (GPMOS) concentration of 1.0 mol / liter is mixed with the above-mentioned (2) so that GPMOS becomes 23.5 molar equivalents relative to neodymium. Was added to the polymerization solution obtained in the above and treated at 50 ° C. for 60 minutes.
Next, 1.2 ml of sorbitan trioleate (manufactured by Kanto Chemical Co., Inc.) was added, and after a further denaturation reaction at 60 ° C. for 1 hour, the polymerization system was treated with an antioxidant 2,2′-methylene-bis (4 -Ethyl-6-tert-butylphenol) (NS-5) 2 ml of isopropanol 5% by mass solution is added to stop the reaction, and reprecipitation is performed in isopropanol containing a small amount of NS-5, followed by drum drying. As a result, modified polybutadiene was obtained. In this modified polybutadiene, no macrogel was observed, and the 100 ° C. Mooney viscosity (ML _{1 + 4} : 100 ° C.) was 59. The microstructure after the modification treatment was the same as the microstructure of the intermediate polymer.

Production Example 2 Production of Liquid Styrene-Butadiene Copolymer Rubber A butadiene cyclohexane solution (16%) and a styrene cyclohexane solution (21%) were added to a dried, nitrogen-substituted 800 ml pressure-resistant glass container. 40 g of styrene monomer and 10 g of styrene monomer were injected, 0.66 mmol of 2,2-ditetrahydrofurylpropane was injected, and 1.32 mmol of n-butyllithium (BuLi) was added thereto, Polymerization was carried out in a hot water bath at 50 ° C. for 1.5 hours. The polymerization conversion was almost 100%.
Thereafter, 0.5 ml of a 5 wt% solution of 2,6-di-t-butyl-p-cresol (BHT) in isopropanol was further added to the polymerization system to stop the reaction. Then, the polymer was obtained by drying according to a conventional method. The bound styrene content by NMR method was 20% by mass, and the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography method (GPC method) was 80,000.

Examples 1-5 and Comparative Examples 1-11
A rubber composition having a composition shown in Table 1 was prepared, and each rubber composition was disposed on a tread of a pneumatic tire for a passenger car having a tire size of 195 / 60R15, and 16 types of pneumatic tires were made as trials. Table 1 shows the performance evaluation results of each tire.

［注］
１）スチレン−ブタジエン共重合体ゴム：ＪＳＲ（株）製「ＳＢＲ１７１２」、オイル含量２７．３質量％油展ＳＢＲ
２）スチレン−ブタジエン共重合体ゴム：ＪＳＲ（株）製「ＳＢＲ１７２１」、オイル含量２７．３質量％油展ＳＢＲ
３）スチレン−ブタジエン共重合体ゴム：旭化成（株）社製［ＳＢＲ Ｔｕｆｄｅｎ３３３５］、オイル含有量２７．３質量％油展ＳＢＲ
４）ＲＳＳ＃３
５）ポリブタジエンゴム：ＪＳＲ（株）製「ＢＲ０１」
６）製造例１の変性ポリブタジエン
７）製造例２の液状スチレン−ブタジエン共重合体ゴム：重量平均分子量８０，０００
８）東海カーボン（株）製［シースト７ＨＭ（Ｎ２３４）］
９）東ソー・シリカ（株）製「ＡＱ」
１０）デグサ社製「Ｓｉ６９」
１１）ＴＤＡＥ：新日本石油（株）社製「ＴＤＡＥ」：蒸留処理アロマチック系プロセス油
１２）Ｎ−（１，３−ジメチルブチル）−Ｎ’−フェニル−ｐ−フェニレンジアミン
１３）２，２，４−トリメチルー１，２−ジヒドロキノリン重合物
１４）ジフェニルグアニジン
１５）Ｎ−シクロヘキシル−２−ベンゾチアジルスルフェンアミド
１６）ジベンゾチアジルジスルフィド
第１表から分かるように、比較例２〜５は、従来手法での改良を試みているもので、やはり比較例１対比で、３つの路面での制動性能をともに改良することは実現していない。
実施例１は、本発明の基本的な要素を盛り込んだゴム組成物を適用したタイヤであって、３つの路面での制動性能が、いずれも改良されている。実施例２〜５は、本発明の基本的要素に従来の手法を組み合わせて各路面での所望の性能を向上させた結果を表している。それに比べて、比較例６〜１１は、本発明に係わるゴム材料を用いても本発明の範囲を超えた配合では、目的とする各路面での制動性能を、共に向上させることは出来ていない。

[note]
1) Styrene-butadiene copolymer rubber: “SBR1712” manufactured by JSR Corporation, oil content 27.3 mass% oil-extended SBR
2) Styrene-butadiene copolymer rubber: “SBR1721” manufactured by JSR Corporation, oil content 27.3 mass% oil-extended SBR
3) Styrene-butadiene copolymer rubber: manufactured by Asahi Kasei Corporation [SBR Tufden 3335], oil content 27.3 mass% oil-extended SBR
4) RSS # 3
5) Polybutadiene rubber: “BR01” manufactured by JSR Corporation
6) Modified polybutadiene of Production Example 1 7) Liquid styrene-butadiene copolymer rubber of Production Example 2: Weight average molecular weight 80,000
8) [Seast 7HM (N234)] manufactured by Tokai Carbon Co., Ltd.
9) “AQ” manufactured by Tosoh Silica Corporation
10) “Si69” manufactured by Degussa
11) TDAE: “TDAE” manufactured by Nippon Oil Co., Ltd .: Distilled aromatic process oil 12) N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine 13) 2,2 , 4-Trimethyl-1,2-dihydroquinoline polymer 14) Diphenylguanidine 15) N-cyclohexyl-2-benzothiazylsulfenamide 16) Dibenzothiazyl disulfide As can be seen from Table 1, Comparative Examples 2-5 are This is an attempt to improve the conventional method, and it has not been realized that the braking performance on the three road surfaces is improved as compared with Comparative Example 1.
Example 1 is a tire to which a rubber composition incorporating the basic elements of the present invention is applied, and the braking performance on three road surfaces is improved. Examples 2 to 5 show the results of improving the desired performance on each road surface by combining the conventional elements with the basic elements of the present invention. In contrast, in Comparative Examples 6 to 11, even when the rubber material according to the present invention is used, the braking performance on each target road surface cannot be improved with a composition exceeding the scope of the present invention. .

  The pneumatic tire of the present invention is obtained using a rubber composition containing a modified conjugated diene polymer obtained by a specific method and a low molecular weight styrene-butadiene copolymer rubber having a specific molecular weight in a predetermined ratio. The braking performance on the wet road surface, the braking performance on the snow and icy road surface, and the braking performance on the dry road surface are both good.

Claims (14)

(A) (A-1) 5-50 mass% of modified polybutadiene obtained by modifying the active terminal of polybutadiene having a cis-1,4-bond content of 75 mol% or more with at least a hydrocarbyloxysilane compound; A-2) A styrene-butadiene copolymer rubber having a weight average molecular weight of 20,000 to 150,000, 4 to 45% by mass, and (A-3) a styrene-butadiene copolymer rubber other than (A-2). be empty pneumatic tire using the rubber composition containing a rubber component comprising, the hydrocarbyloxy silane compound is represented by the following (a) the general formula (I) and at least one member selected from a partial condensate thereof (thio) A pneumatic tire characterized by being an epoxy group-containing hydrocarbyloxysilane compound .

[ Wherein , A ¹ is a monovalent group having a (thio) epoxy group, R ¹ is a single bond or a divalent inert hydrocarbon group, and R ² and R ³ each independently has 1 carbon atom. It shows the 20 monovalent aliphatic hydrocarbon group or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, n is an integer of 0 to 2, when R ² are a plurality, the plurality of R ² may be the same or different, when oR ³ there are a plurality, the plurality of oR ³ may be the same or different, and in the molecule does not include an active proton and an onium salt. ] 2. The pneumatic tire according to claim 1 , wherein the rubber composition contains 30 to 150 parts by mass of (B) silica with respect to 100 parts by mass of the (A) rubber component.   In the rubber composition, with respect to (A) 100 parts by mass of the rubber component, (C) an inorganic filler other than carbon black and / or silica, and the total amount of the component (B) with silica is 35 to 180 parts by mass. The pneumatic tire according to claim 2, wherein the pneumatic tire is included at a ratio of 5 to 80 parts by mass so as to be in a range of 5%.   The pneumatic tire according to claim 2 or 3, wherein the rubber composition further comprises (D) a silane coupling agent in a proportion of 1 to 20% by mass relative to silica of component (B).   The pneumatic tire according to any one of claims 1 to 4, wherein the rubber composition is disposed in a tread portion. The modified polybutadiene of component (A-1) is first modified with a (thio) epoxy group-containing hydrocarbyloxysilane compound at the active end, and further in the presence of a condensation accelerator, with a (thio) epoxy group-containing hydrocarbyloxysilane compound. The pneumatic tire according to any one of claims 1 to 5, wherein the pneumatic tire is secondarily modified. The modified polybutadiene as component (A-1) is obtained by first reacting the active terminal with a (thio) epoxy group-containing hydrocarbyloxysilane compound and then reacting with a carboxylic acid partial ester of a polyhydric alcohol. The pneumatic tire according to any one of 1 to 5. (A-1) component of the modified polybutadiene is, after the first modified by the active end (thio) epoxy group-containing hydrocarbyloxy silane compound, was introduced into the further terminal in the presence of a condensation accelerator (thio) epoxy group-containing The pneumatic tire according to any one of claims 1 to 5, wherein the pneumatic tire is formed by a condensation reaction of a hydrocarbyloxysilane compound residue and an unreacted (thio) epoxy group-containing hydrocarbyloxysilane compound . The pneumatic tire according to claim 6, wherein the modified polybutadiene as the component (A-1) is further reacted with a carboxylic acid partial ester of a polyhydric alcohol after secondary modification. The pneumatic tire according to claim 8, wherein the modified polybutadiene of component (A-1) is further reacted with a carboxylic acid partial ester of a polyhydric alcohol after the condensation reaction. (Thio) epoxy group-containing hydrocarbyloxysilane compounds are 2-glycidoxyethyltrimethoxysilane, 2-glycidoxyethyltriethoxysilane, (2-glycidoxyethyl) methyldimethoxysilane, 3-glycidoxypropyl Trimethoxysilane, 3-glycidoxypropyltriethoxysilane, (3-glycidoxypropyl) methyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) 1) One or more compounds selected from ethyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl (methyl) dimethoxysilane, and those obtained by replacing the epoxy group in these compounds with a thioepoxy group. Sky according to any one of 10 Tire enters. The (thio) epoxy group-containing hydrocarbyloxysilane compound is at least one compound selected from 3-glycidoxypropyltrimethoxysilane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. The described pneumatic tire.   The pneumatic tire according to any one of claims 7, 9 and 10, wherein the carboxylic acid partial ester of the polyhydric alcohol is a monoester, diester or triester of sorbitan fatty acid. The condensation accelerator is composed of at least one selected from the compounds represented by the following formula (d), general formula (IV), (e) general formula (V), and (f) general formula (VI), and water. The pneumatic tire according to claim 6, 8, 9, or 10 .
(D) Tin oxide having a oxidation number of 2 represented by the general formula (IV) and a carboxylate of 3 to 20 carbon atoms Sn (OCOR ¹⁰ ) ₂ (IV)
[Wherein, R ¹⁰ is an organic group having 2 to 19 carbon atoms, and when there are a plurality of them, they may be the same or different. ]
(E) Tin compound R ¹¹ _r SnA ⁴ _t B ¹ _(4-tr) (V) represented by general formula (V) having an oxidation number of 4
[Wherein, r is an integer of 1 to 3, t is an integer of 1 or 2, and t + r is an integer of 3 or 4. R ¹¹ is an aliphatic hydrocarbon group having 1 to 30 carbon atoms, and B ¹ is a hydroxyl group or a halogen. A ⁴ is (a) an aliphatic carboxylic acid residue having 2 to 30 carbon atoms, (b) a 1,3-dicarbonyl-containing group having 5 to 30 carbon atoms, and (c) a hydrocarbyloxy group having 3 to 30 carbon atoms. And (d) a group selected from a siloxy group having a total of three substitutions (which may be the same or different) with a hydrocarbyl group having 1 to 20 carbon atoms and / or a hydrocarbyloxy group having 1 to 20 carbon atoms, and R ¹¹ may if there are multiple the same or different, may be the same or different if A ⁴ have multiple. ]
(F) Titanium compound of oxidation number 4 represented by general formula (VI) A ⁵ _x TiB ² _(4-x) (VI)
[Wherein x is an integer of 2 or 4. A ⁵ is (i) a hydrocarbyloxy group having 3 to 30 carbon atoms, (b) a siloxy group that is tri-substituted in total with an alkyl group having 1 to 30 carbon atoms and / or a hydrocarbyloxy group having 1 to 20 carbon atoms, When there are a plurality of A ^{5 s,} they may be the same or different. B ² is a 1,3-dicarbonyl-containing group having 5 to 30 carbon atoms, and when there are a plurality of B ² , they may be the same or different. ]