JP6728642B2 - Summer tires and studless tires - Google Patents

Description

TECHNICAL FIELD The present invention relates to a summer tire and a studless tire having a base tread produced by using a predetermined rubber composition.

Conventionally, the fuel consumption of automobiles has been reduced by reducing the rolling resistance of tires. As a method for reducing fuel consumption, for example, a method is known in which the tread portion has a two-layer structure (base tread and cap tread) and a rubber composition having a low heat generation property is used for the base tread. The demand for better fuel economy is becoming stronger and stronger, and better low heat buildup is required.

In summer tires, due to improvements in the performance of automobiles and the development of road networks, it is required that the tires have improved steering stability, especially during high-speed driving. When a large amount of the reinforcing filler is blended with the base tread, the rigidity of the tread portion is increased and the steering stability is improved, but the low fuel consumption performance is deteriorated. On the other hand, if the amount of the reinforcing filler is reduced, the fuel economy performance is improved, but the rigidity (steering stability) is reduced. As described above, in summer tires, it is difficult to simultaneously improve steering stability and fuel economy performance.

In addition, spike tires have been used and chains have been attached to the tires for running on snow and snow roads, but environmental problems such as dust problems occur, so studless tires have been developed as an alternative tire for running on snow and snow roads. .. Studless tires have larger road surface irregularities on snowy roads than on ordinary roads, and are devised in terms of materials and design. For example, a rubber composition has been developed in which a diene rubber excellent in low temperature characteristics is blended and a large amount of a softening agent is blended in order to enhance the softening effect. In addition, in order to pursue low-temperature characteristics, high-cis type butadiene is often blended with the diene rubber.
Furthermore, in recent years, silica is often blended in order to balance the performance on ice and snow and the low fuel consumption performance. However, when a high cis BR is used, the affinity with silica is deteriorated, and there is still room for improvement in terms of improving the above performance in a studless tire in a balanced manner.

As described above, in summer tires, there is room for improvement in achieving both a high level of steering stability and low fuel consumption performance. Further, in the studless tire, there is room for improvement in achieving both low fuel consumption performance and performance on ice and snow at a high level.

It is an object of the present invention to solve the above problems and provide a summer tire that achieves both high fuel efficiency and steering stability at a high level. It is also an object to provide a studless tire that achieves both high fuel efficiency performance and performance on snow and snow at a high level.

The present invention is a summer tire having a tread produced using a rubber composition, wherein the rubber composition contains a rubber component containing a natural rubber and a modified conjugated diene polymer, and silica, and the modified The conjugated diene polymer has a cis-1,4-bond content of 94.0% by mass or more, and a conjugated diene polymer having an active end is used, and an alkoxysilyl group is added to the active end of the conjugated diene polymer. A modification step (A) of carrying out a modification reaction in which an alkoxysilane compound having two or more reactive groups containing a group is introduced, and included in Group 4, Group 12, Group 13, Group 14 and Group 15 of the periodic table. A condensation step (B) in which a residue of the alkoxysilane compound introduced at the active terminal is subjected to a condensation reaction in the presence of a condensation catalyst containing at least one element selected from the group consisting of elements, The conjugated diene-based polymer is obtained by a production method using a conjugated diene-based polymer polymerized in the presence of a catalyst composition containing a mixture of the following components (a) to (c) as a main component. The total content of the natural rubber and the modified conjugated diene-based polymer is 20 to 100% by mass in 100% by mass of the component, and the content of the modified conjugated diene-based polymer is 10 to 100% by mass in the rubber component. It is 90 mass %, and the content of the silica is 1 part by mass or more with respect to 100 parts by mass of the rubber component, and relates to a summer tire.
Component (a): A lanthanoid-containing compound containing at least one element selected from the group consisting of lanthanoids, or a reaction product obtained by reacting the lanthanoid-containing compound with a Lewis base (b) component: alumino Xanthane and an organoaluminum compound represented by the general formula (1); AlR ¹ R ² R ³ (wherein, in the general formula (1), R ¹ and R ² are the same or different and have 1 to 10 carbon atoms). of .R ³ representing a hydrocarbon group or a hydrogen atom are the same or different and R ¹ and R ^2, at least one compound selected from the group consisting of representing.) the hydrocarbon group having 1 to 10 carbon atoms Component (c): an iodine-containing compound containing at least one iodine atom in its molecular structure

The ratio (Mw/Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the conjugated diene polymer measured by gel permeation chromatography is preferably 3.5 or less.

The 1,2-vinyl bond content of the conjugated diene polymer is preferably 0.5% by mass or less.

The condensation catalyst preferably contains titanium (Ti).

The alkoxysilane compound preferably contains at least one functional group selected from the group consisting of the following (f) to (i).
(F); Epoxy group (g); Isocyanate group (h); Carbonyl group (i); Cyano group

In the modification step (A), it is preferable to add an alkoxysilane compound containing at least one functional group selected from the group consisting of the following (j) to (l).
(J); amino group (k); imino group (l); mercapto group

The condensation reaction in the condensation step (B) is preferably performed in an aqueous solution having a pH of 9 to 14 and a temperature of 85 to 180°C.

The conjugated diene compound constituting the modified conjugated diene polymer is at least one conjugated diene compound selected from the group consisting of 1,3-butadiene, isoprene and 2,3-dimethyl-1,3-butadiene. It is preferable.

The nitrogen adsorption specific surface area of the silica is preferably 40 to 300 m ² /g.

The present invention relates to a method for manufacturing the summer tire, which includes a step of kneading a rubber component containing the natural rubber and a modified conjugated diene polymer with the silica.

The present invention is also a studless tire having a base tread produced using a rubber composition, wherein the rubber composition contains a rubber component containing a natural rubber and a modified conjugated diene polymer, and silica. The modified conjugated diene-based polymer has a cis-1,4-bond content of 94.0% by mass or more, and a conjugated diene-based polymer having an active end is used, and the active end of the conjugated diene-based polymer is A modification step (A) of carrying out a modification reaction for introducing an alkoxysilane compound having two or more reactive groups containing an alkoxysilyl group, and to group 4, 12, 13, 13, 14 and 15 of the periodic table. A condensation step (B) in which the residue of the alkoxysilane compound introduced into the active terminal is subjected to a condensation reaction in the presence of a condensation catalyst containing at least one element selected from the group consisting of the elements contained. As the conjugated diene polymer, a conjugated diene polymer obtained by a production method using a conjugated diene polymer polymerized in the presence of a catalyst composition containing a mixture of the following components (a) to (c) as a main component, The total content of the natural rubber and the modified conjugated diene-based polymer is 20 to 100% by mass in 100% by mass of the rubber component, and the content of the modified conjugated diene-based polymer is 100% by mass in the rubber component. It is 10-90 mass %, and the content of the said silica is 1 mass part or more with respect to 100 mass parts of the said rubber components, It is related with the studless tire characterized by the above-mentioned.
Component (a): A lanthanoid-containing compound containing at least one element selected from the group consisting of lanthanoids, or a reaction product obtained by reacting the lanthanoid-containing compound with a Lewis base (b) component: alumino Xanthane and an organoaluminum compound represented by the general formula (1); AlR ¹ R ² R ³ (wherein, in the general formula (1), R ¹ and R ² are the same or different and have 1 to 10 carbon atoms). of .R ³ representing a hydrocarbon group or a hydrogen atom are the same or different and R ¹ and R ^2, at least one compound selected from the group consisting of representing.) the hydrocarbon group having 1 to 10 carbon atoms Component (c): an iodine-containing compound containing at least one iodine atom in its molecular structure

The ratio (Mw/Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the conjugated diene polymer measured by gel permeation chromatography is preferably 3.5 or less.

The 1,2-vinyl bond content of the conjugated diene polymer is preferably 0.5% by mass or less.

The condensation catalyst preferably contains titanium (Ti).

The alkoxysilane compound preferably contains at least one functional group selected from the group consisting of the following (f) to (i).
(F); Epoxy group (g); Isocyanate group (h); Carbonyl group (i); Cyano group

In the modification step (A), it is preferable to add an alkoxysilane compound containing at least one functional group selected from the group consisting of the following (j) to (l).
(J); amino group (k); imino group (l); mercapto group

The condensation reaction in the condensation step (B) is preferably performed in an aqueous solution having a pH of 9 to 14 and a temperature of 85 to 180°C.

The conjugated diene compound constituting the modified conjugated diene polymer is at least one conjugated diene compound selected from the group consisting of 1,3-butadiene, isoprene and 2,3-dimethyl-1,3-butadiene. It is preferable.

The nitrogen adsorption specific surface area of the silica is preferably 40 to 300 m ² /g.

The present invention relates to a method for producing a studless tire, which comprises a step of kneading a rubber component containing the natural rubber and a modified conjugated diene polymer with the silica.

According to the present invention, a rubber component containing a natural rubber and a specific modified conjugated diene-based polymer, and a summer tire having a base tread produced using a rubber composition containing a predetermined amount of silica. It is possible to provide a summer tire having both high performance and steering stability at a high level. Further, according to the present invention, a rubber component containing a natural rubber and a specific modified conjugated diene polymer, and a studless tire having a base tread produced using a rubber composition containing a predetermined amount of silica, We can also provide studless tires that achieve both high fuel efficiency and snow and snow performance at a high level.

The summer tire of the present invention has a base tread produced by using a rubber composition containing natural rubber and a rubber component containing a specific modified conjugated diene polymer and a predetermined amount of silica. As a result, both low fuel consumption performance and steering stability can be achieved at a high level. The studless tire of the present invention has a base tread produced by using a rubber composition containing a natural rubber and a rubber component containing a specific modified conjugated diene polymer and silica in a predetermined amount. As a result, both low fuel consumption performance and performance on snow and ice can be achieved at a high level.

Usually, when a rubber component in a silica-blended rubber composition is a blend of natural rubber and butadiene rubber, since silica is unevenly distributed in the natural rubber phase, there is a limit to the dispersion of silica in the composition, resulting in low fuel consumption. Performance, handling stability, low temperature characteristics, wear resistance, and fracture characteristics tend to deteriorate. On the other hand, in the rubber composition of the present invention, in the silica compounding system, since natural rubber and a specific modified conjugated diene polymer are used as the rubber component, silica is used as the natural rubber phase and the specific modified conjugated diene system. Since it can be distributed and dispersed in both phases of the polymer, the dispersibility of silica can be improved. As a result, the summer tire of the present invention having the base tread produced using such a rubber composition can alleviate the concentration of stress when strain is applied, and thus, has low fuel consumption performance and steering stability. Is considered to be compatible at a high level. Further, the studless tire of the present invention having a base tread produced by using such a rubber composition can relieve the concentration of stress when strain is applied, and thus, has low fuel consumption performance and performance on snow and snow. It is considered that they can be compatible at a high level.

Regarding the rubber composition in the summer tire of the present invention, the total content of natural rubber (NR) and the modified conjugated diene-based polymer is 20 to 100% by mass in 100% by mass of the rubber component, and the modified conjugated diene-based compound is used. The content of the polymer is 10 to 90% by mass. Thus, the rubber composition in the summer tire of the present invention is one in which NR and the modified conjugated diene-based polymer are blended, and particularly, the blended amount of the modified conjugated diene-based polymer is within a specific range. .. When the total content of NR and the modified conjugated diene polymer and the content of the modified conjugated diene polymer are in such ranges, sufficient fuel economy performance and steering stability can be exhibited.
The lower limit of the total content is preferably 30% by mass or more, more preferably 60% by mass or more, further preferably 80% by mass or more, and most preferably 100% by mass. As described above, as the total content of NR and the modified conjugated diene polymer is higher, sufficient fuel economy performance and steering stability can be exhibited.
The lower limit of the content of the modified conjugated diene polymer is preferably 15% by mass or more, more preferably 25% by mass or more, further preferably 35% by mass or more, and the upper limit is preferably 80% by mass or less. , More preferably 60% by mass or less, further preferably 50% by mass or less.

Regarding the rubber composition in the summer tire of the present invention, the content of NR in 100% by mass of the rubber component is preferably 20% by mass or more, and more preferably 40% by mass, from the viewpoint that the effect of the present invention can be better obtained. % Or more, more preferably 50% by mass or more, while preferably 85% by mass or less, more preferably 75% by mass or less, further preferably 65% by mass or less.

Regarding the rubber composition in the studless tire of the present invention, the total content of natural rubber (NR) and the modified conjugated diene-based polymer is 20 to 100% by mass in 100% by mass of the rubber component. The content of the polymer is 10 to 90% by mass. Thus, the rubber composition in the studless tire of the present invention is one in which NR and the modified conjugated diene-based polymer are blended, and particularly, the blended amount of the modified conjugated diene-based polymer is within a specific range. .. When the total content of NR and the modified conjugated diene-based polymer and the content of the modified conjugated diene-based polymer are in such ranges, sufficient fuel economy performance and performance on ice and snow can be exhibited.
The lower limit of the total content is preferably 30% by mass or more, more preferably 60% by mass or more, further preferably 80% by mass or more, and most preferably 100% by mass. Thus, the higher the total content of NR and the modified conjugated diene-based polymer, the more fuel-efficient performance and performance on snow and ice can be exhibited.
The lower limit of the content of the modified conjugated diene polymer is preferably 20% by mass or more, more preferably 40% by mass or more, further preferably 55% by mass or more, particularly preferably 65% by mass or more, and the upper limit. Is preferably 80% by mass or less, more preferably 75% by mass or less.

Regarding the rubber composition in the studless tire of the present invention, the content of NR in 100% by mass of the rubber component is preferably 20% by mass or more, and more preferably 25% by mass, from the viewpoint that the effect of the present invention can be better obtained. %, on the other hand, preferably 80% by mass or less, more preferably 60% by mass or less, further preferably 45% by mass or less, and particularly preferably 35% by mass or less.

Examples of the NR include commonly used ones such as TSR20 and RSS#3.

The modified conjugated diene-based polymer has a cis-1,4-bond content of 94.0 mass% or more, and a conjugated diene-based polymer having an active terminal is used, and the active terminal of the conjugated diene-based polymer is A modification step (A) of carrying out a modification reaction for introducing an alkoxysilane compound having two or more reactive groups containing an alkoxysilyl group, and to group 4, 12, 13, 13, 14 and 15 of the periodic table. A condensation step (B) in which the residue of the alkoxysilane compound introduced into the active terminal is subjected to a condensation reaction in the presence of a condensation catalyst containing at least one element selected from the group consisting of the elements contained. As the conjugated diene polymer, a conjugated diene polymer polymerized in the presence of a catalyst composition containing a mixture of the following components (a) to (c) as a main component is obtained by a production method.
Component (a): A lanthanoid-containing compound containing at least one element selected from the group consisting of lanthanoids, or a reaction product obtained by reacting the lanthanoid-containing compound with a Lewis base (b) component: alumino Xanthane and an organoaluminum compound represented by the general formula (1); AlR ¹ R ² R ³ (wherein, in the general formula (1), R ¹ and R ² are the same or different and have 1 to 10 carbon atoms). of .R ³ representing a hydrocarbon group or a hydrogen atom are the same or different and R ¹ and R ^2, at least one compound selected from the group consisting of representing.) the hydrocarbon group having 1 to 10 carbon atoms Component (c): an iodine-containing compound containing at least one iodine atom in its molecular structure

That is, a modification reaction of introducing an alkoxysilane compound into the active terminal of a conjugated diene-based polymer having a cis-1,4-bond content of 94.0% by mass or more is carried out, and groups 4 and 12 of the periodic table are used. Reaction of the alkoxysilane compound residue of the alkoxysilane compound introduced at the active end in the presence of a condensation catalyst containing at least one element selected from the group 13, group 14, group 14 and group 15 elements By doing so, the modified conjugated diene polymer used in the present invention can be produced.
Since the modified conjugated diene polymer is manufactured by such a manufacturing method, it is excellent in low fuel consumption performance, steering stability, performance on ice and snow, abrasion resistance, and fracture characteristics. Since the rubber composition in the summer tire of the present invention contains such a modified conjugated diene polymer, natural rubber, and silica, it was produced using such a rubber composition. Summer tires with a base tread have excellent fuel economy and steering stability. Further, since the rubber composition in the studless tire of the present invention contains such a modified conjugated diene polymer, natural rubber and silica, it was produced using such a rubber composition. A studless tire having a base tread is excellent in low fuel consumption performance and performance on ice and snow.

The modified conjugated diene-based polymer is obtained by introducing the polyfunctional alkoxysilane compound and further subjecting the introduced residue of the alkoxysilane compound to a condensation reaction. It is difficult to specify whether or not the modified conjugated diene polymer is present, and it is impossible or almost not practical to directly specify the modified conjugated diene polymer by its structure or properties.

In the modification step (A), a conjugated diene polymer having an amount of cis-1,4-bonds of 94.0% by mass or more and having an active terminal is used, and an alkoxy group is added to the active terminal of the conjugated diene polymer. This is a step of performing a modification reaction in which an alkoxysilane compound having two or more reactive groups containing a silyl group is introduced.

The conjugated diene polymer has a cis-1,4-bond content of 94.0 mass% or more, and is a conjugated diene polymer having an active terminal. The cis-1,4-bond content is preferably 94.6% by mass or more, more preferably 98.5% by mass or more, further preferably 99.0% by mass or more, and even more preferably It is 99.2 mass% or more. When the cis-1,4-bond content is less than 94.0% by mass, the performance on snow and snow of a summer tire or a studless tire produced using a rubber composition containing a modified conjugated diene polymer, and wear resistance , Destruction characteristics, low fuel consumption performance, and steering stability may not be sufficient. In the present specification, the amount of cis-1,4-bond is a value calculated from the signal intensity measured by NMR analysis.

The conjugated diene-based polymer is selected from the group consisting of 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene and myrcene. A polymer having a repeating unit derived from at least one kind of monomer can be used. In particular, a polymer having a repeating unit derived from at least one monomer selected from the group consisting of 1,3-butadiene, isoprene and 2,3-dimethyl-1,3-butadiene can be preferably used. That is, the conjugated diene compound constituting the modified conjugated diene polymer is at least one conjugated diene compound selected from the group consisting of 1,3-butadiene, isoprene and 2,3-dimethyl-1,3-butadiene. There is also one of the preferred embodiments of the present invention.

As the conjugated diene polymer, a polymer having a repeating unit derived from 1,3-butadiene can be used more preferably.
In 100% by mass of the repeating unit of the conjugated diene polymer, the ratio of the repeating unit derived from 1,3-butadiene is preferably 60% by mass or more, more preferably 70% by mass or more, further preferably 80% by mass or more. , Particularly preferably 90% by mass or more, and most preferably 100% by mass. As a result, the effects of the present invention can be obtained better.

When producing such a conjugated diene polymer, the polymerization may be carried out using a solvent or may be carried out without a solvent. As the solvent used for the polymerization (polymerization solvent), an inert organic solvent can be used, and specifically, butane, pentane, hexane, heptane, and other saturated aliphatic hydrocarbons having 4 to 10 carbon atoms, cyclo Saturated alicyclic hydrocarbons having 6 to 20 carbon atoms such as pentane and cyclohexane, monoolefins such as 1-butene and 2-butene, aromatic hydrocarbons such as benzene, toluene and xylene, methylene chloride, chloroform and tetrachloride. Examples thereof include halogenated hydrocarbons such as carbon, trichloroethylene, perchloroethylene, 1,2-dichloroethane, chlorobenzene, bromobenzene and chlorotoluene.

The polymerization reaction temperature at the time of producing the conjugated diene polymer is preferably -30 to 200°C, more preferably 0 to 150°C. The form of the polymerization reaction is not particularly limited, and may be performed using a batch reactor or may be performed continuously using a device such as a multistage continuous reactor. When a polymerization solvent is used, the monomer concentration in this solvent is preferably 5 to 50% by mass, more preferably 7 to 35% by mass. Further, from the viewpoint of the efficiency of production of the conjugated diene polymer, and from the viewpoint of not deactivating the conjugated diene polymer having an active terminal, there is a deactivating action of oxygen, water, carbon dioxide gas, etc. in the polymerization system. It is preferable to prevent the compound from being mixed in as much as possible.

Further, as the conjugated diene polymer used in producing the modified conjugated diene polymer in the present invention, a catalyst composition (hereinafter, referred to as "catalyst") containing a mixture of the following components (a) to (c) as a main component. Also referred to as a), a conjugated diene-based polymer polymerized in the presence of () is used.
Component (a): A lanthanoid-containing compound containing at least one element selected from the group consisting of lanthanoids, or a reaction product obtained by reacting the lanthanoid-containing compound with a Lewis base (b) component: alumino Xanthane and an organoaluminum compound represented by the general formula (1); AlR ¹ R ² R ³ (wherein, in the general formula (1), R ¹ and R ² are the same or different and have 1 to 10 carbon atoms). of .R ³ representing a hydrocarbon group or a hydrogen atom are the same or different and R ¹ and R ^2, at least one compound selected from the group consisting of representing.) the hydrocarbon group having 1 to 10 carbon atoms Component (c): an iodine-containing compound containing at least one iodine atom in its molecular structure

By using such a catalyst, a conjugated diene polymer having a cis-1,4-bond content of 94.0% by mass or more can be obtained. Further, this catalyst is useful for industrial production because it does not require a polymerization reaction at an extremely low temperature and the operation is simple.

The component (a) is a lanthanoid-containing compound containing at least one element selected from the group consisting of lanthanoids, or a reaction product obtained by reacting the lanthanoid-containing compound with a Lewis base. Among the lanthanoids, neodymium, praseodymium, cerium, lanthanum, gadolinium and samarium are preferable. Of these, neodymium is particularly preferable in the production method of the present invention. The lanthanoids may be used alone or in combination of two or more. Specific examples of the lanthanoid-containing compound include lanthanoid carboxylates, alkoxides, β-diketone complexes, phosphates and phosphites. Of these, carboxylates or phosphates are preferable, and carboxylates are more preferable.

Specific examples of the carboxylic acid salt of the lanthanoid include a salt of a carboxylic acid represented by the general formula (2); (R ⁴ —COO) ₃ M (however, in the general formula (2), M Represents a lanthanoid, and R ⁴ is the same or different and represents a hydrocarbon group having 1 to 20 carbon atoms). In the general formula (2), R ⁴ is preferably a saturated or unsaturated alkyl group, and more preferably a linear, branched or cyclic alkyl group. Further, the carboxyl group is bonded to a primary, secondary or tertiary carbon atom. Specifically, octanoic acid, 2-ethylhexanoic acid, oleic acid, stearic acid, benzoic acid, naphthenic acid, trade name "Versatic acid" (manufactured by Shell Chemical Co., carboxyl group bonded to tertiary carbon atom) Carboxylic acid) and the like. Among these, salts of versatic acid, 2-ethylhexanoic acid and naphthenic acid are preferable.

Specific examples of the alkoxide of the above-mentioned lanthanoid include those represented by the general formula (3); (R ⁵ O) ₃ M (wherein M represents a lanthanoid). ). In the general formula (3), specific examples of the alkoxy group represented by “R ⁵ O” include 2-ethyl-hexylalkoxy group, oleylalkoxy group, stearylalkoxy group, phenoxy group, benzylalkoxy group and the like. Are listed. Of these, a 2-ethyl-hexylalkoxy group and a benzylalkoxy group are preferable.

Specific examples of the lanthanoid β-diketone complex include acetylacetone complex, benzoylacetone complex, propionitrileacetone complex, valerylacetone complex, and ethylacetylacetone complex. Of these, acetylacetone complex and ethylacetylacetone complex are preferable.

Specific examples of the lanthanide phosphate or phosphite include bis(2-ethylhexyl) phosphate, bis(1-methylheptyl) phosphate, bis(p-nonylphenyl) phosphate, bis(phosphate Polyethylene glycol-p-nonylphenyl), phosphoric acid (1-methylheptyl) (2-ethylhexyl), phosphoric acid (2-ethylhexyl) (p-nonylphenyl), 2-ethylhexylphosphonate mono-2-ethylhexyl, 2- Ethylhexylphosphonate mono-p-nonylphenyl, bis(2-ethylhexyl)phosphinic acid, bis(1-methylheptyl)phosphinic acid, bis(p-nonylphenyl)phosphinic acid, (1-methylheptyl)(2-ethylhexyl) Examples thereof include salts such as phosphinic acid and (2-ethylhexyl)(p-nonylphenyl)phosphinic acid. Of these, salts of bis(2-ethylhexyl) phosphate, bis(1-methylheptyl) phosphate, mono-2-ethylhexyl 2-ethylhexylphosphonate, and bis(2-ethylhexyl)phosphinic acid are preferable.

Among these, as the lanthanoid-containing compound, neodymium phosphate or neodymium carboxylate is particularly preferable, and neodymium versatic acid salt or neodymium 2-ethylhexanoate is most preferable.

In order to solubilize the above-mentioned lanthanoid-containing compound in a solvent, or for long-term stable storage, mixing a lanthanoid-containing compound with a Lewis base, or reacting a lanthanoid-containing compound with a Lewis base to produce a reaction It is also preferable to use a product. The amount of the Lewis base is preferably 0 to 30 mol, and more preferably 1 to 10 mol, based on 1 mol of the lanthanoid. Specific examples of the Lewis base include acetylacetone, tetrahydrofuran, pyridine, N,N-dimethylformamide, thiophene, diphenyl ether, triethylamine, organic phosphorus compounds, monohydric or dihydric alcohols and the like. The components (a) described above may be used alone or in combination of two or more kinds.

The component (b) is an aluminoxane and an organoaluminum compound represented by the general formula (1); AlR ¹ R ² R ³ (provided that in the general formula (1), R ¹ and R ² are the same. Or, differently, represents a hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom, and R ³ is the same as or different from R ¹ and R ² and represents a hydrocarbon group having 1 to 10 carbon atoms.). It is at least one compound selected from

The aluminoxane (hereinafter, also referred to as “alumoxane”) is a compound whose structure is represented by the following general formula (4) or (5). Fine Chemical, 23, (9), 5 (1994), J. Am. Chem. Soc. 115, 4971 (1993), and J. Am. Chem. Soc. , 117, 6465 (1995), which may be an alumoxane aggregate.

In the general formulas (4) and (5), R ⁶ is the same or different and represents a hydrocarbon group having 1 to 20 carbon atoms. p is an integer of 2 or more.
Specific examples of R ⁶ include a methyl group, an ethyl group, a propyl group, a butyl group, an isobutyl group, a t-butyl group, a hexyl group, an isohexyl group, an octyl group and an isooctyl group. Of these, a methyl group, an ethyl group, an isobutyl group and a t-butyl group are preferable, and a methyl group is particularly preferable.
Further, the above p is preferably an integer of 4 to 100.

Specific examples of the alumoxane include methyl alumoxane (hereinafter, also referred to as “MAO”), ethyl alumoxane, n-propyl alumoxane, n-butyl alumoxane, isobutyl alumoxane, t-butyl alumoxane, hexyl alumoxane. Examples include xanthane and isohexylalumoxane. Of these, MAO is preferable. The alumoxane can be produced by a known method, for example, in an organic solvent such as benzene, toluene, xylene, trialkylaluminum, or dialkylaluminum monochloride, further water, steam, steam-containing nitrogen. It can be produced by adding a gas or a salt having water of crystallization, such as copper sulfate pentahydrate and aluminum sulfate hexahydrate, and reacting. The alumoxanes may be used alone or in combination of two or more.

Specific examples of the organoaluminum compound represented by the general formula (1) include trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-t. -Butyl aluminum, tripentyl aluminum, trihexyl aluminum, tricyclohexyl aluminum, trioctyl aluminum, diethyl aluminum hydride, di-n-propyl aluminum hydride, di-n-butyl aluminum hydride, diisobutyl aluminum hydride, hydrogenation Examples thereof include dihexyl aluminum, diisohexyl aluminum hydride, dioctyl aluminum hydride, diisooctyl aluminum hydride, ethyl aluminum dihydride, n-propyl aluminum dihydride, isobutyl aluminum dihydride and the like. Among these, diisobutylaluminum hydride, triethylaluminum, triisobutylaluminum and diethylaluminum hydride are preferable, and diisobutylaluminum hydride is particularly preferable. The above organoaluminum compounds may be used alone or in combination of two or more.

The component (c) is an iodine-containing compound containing at least one iodine atom in its molecular structure. By using such an iodine-containing compound, a conjugated diene polymer having a cis-1,4-bond content of 94.0% by mass or more can be easily produced. The iodine-containing compound is not particularly limited as long as it contains at least one iodine atom in its molecular structure, for example, iodine, trimethylsilyl iodide, diethyl aluminum iodide, methyl iodide, butyl iodide, Hexyl iodide, octyl iodide, iodoform, diiodomethane, benzylidene iodide, beryllium iodide, magnesium iodide, calcium iodide, barium iodide, zinc iodide, cadmium iodide, mercury iodide, manganese iodide, iodide Examples thereof include rhenium, copper iodide, silver iodide, gold iodide and the like.

Among them, as the iodine-containing compound, general formula (6): R ⁷ _q SiI _4-q (in the general formula (6), R ⁷ are the same or different, and are a hydrocarbon group having 1 to 20 carbon atoms or Represents a hydrogen atom, and q is an integer of 0 to 3), a silicon iodide compound represented by the general formula (7): R ⁸ _r I _4-r (in the general formula (7), R ⁸ ). Are the same or different and each represents a hydrocarbon group having 1 to 20 carbon atoms, and r is an integer of 1 to 3). Since such a silicon iodide compound, an iodohydrocarbon compound, and iodine have good solubility in an organic solvent, they are easy to operate and useful for industrial production. That is, it is also a preferred embodiment of the present invention that the component (c) is at least one iodine-containing compound selected from the group consisting of silicon iodide compounds, iodohydrocarbon compounds, and iodine. Is one of.

Specific examples of the silicon iodide compound (compound represented by the general formula (6)) include trimethylsilyl iodide, triethylsilyl iodide, dimethylsilyl diiodide and the like. Of these, trimethylsilyl iodide is preferable.
Specific examples of the iodohydrocarbon compound (compound represented by the general formula (7)) include methyl iodide, butyl iodide, hexyl iodide, octyl iodide, iodoform, diiodomethane, benzylidene iodide and the like. Are listed. Of these, methyl iodide, iodoform and diiodomethane are preferable.

Among them, iodine, trimethylsilyl iodide, triethylsilyl iodide, dimethylsilyl diiodide, methyl iodide, iodoform and diiodomethane are particularly preferable as the iodine-containing compound, and trimethylsilyl iodide is most preferable. The above iodine-containing compounds may be used alone or in combination of two or more.

The mixing ratio of each of the above components (components (a) to (c)) may be appropriately set as necessary. The blending amount of the component (a) is, for example, preferably 0.00001 to 1.0 mmol, and more preferably 0.0001 to 0.5 mmol based on 100 g of the conjugated diene compound. If the amount is less than 0.00001 mmol, the polymerization activity may decrease. When it is used in excess of 1.0 mmol, the catalyst concentration becomes high and a deashing step may be required.

When the component (b) is alumoxane, the amount of alumoxane to be blended can be represented by the molar ratio of the component (a) and aluminum (Al) contained in the alumoxane. “(a) component”: “ The aluminum (Al) contained in alumoxane (molar ratio) is preferably 1:1 to 1:500, more preferably 1:3 to 1:250, and further preferably 1:5 to 1:200. More preferably. If the blending amount of alumoxane is outside the above range, the catalytic activity may be lowered, or a step of removing the catalyst residue may be required.

When the component (b) is an organoaluminum compound, the blending amount of the organoaluminum compound can be represented by the molar ratio of the component (a) and the organoaluminum compound, and “component (a)”: The “organoaluminum compound” (molar ratio) is preferably 1:1 to 1:700, and more preferably 1:3 to 1:500. If the blending amount of the organoaluminum compound is out of the above range, the catalytic activity may be lowered, or a step of removing the catalyst residue may be required.

The blending amount of the component (c) can be represented by the molar ratio of the iodine atom contained in the component (c) and the component (a), and is ((iodine atom contained in the component (c))/ The ((a) component) (molar ratio) is preferably 0.5 to 3.0, more preferably 1.0 to 2.5, and further preferably 1.2 to 2.0. preferable. When the molar ratio of (iodine atom contained in component (c))/(component (a)) is less than 0.5, the polymerization catalyst activity may decrease. If the molar ratio of (iodine atom contained in component (c))/(component (a)) exceeds 3.0, it may become a catalyst poison.

In the catalyst described above, in addition to the components (a) to (c), if necessary, at least one compound selected from the group consisting of a conjugated diene compound and a non-conjugated diene compound is used as a component (a). The amount is preferably 1000 mol or less, more preferably 3 to 1000 mol, and still more preferably 5 to 300 mol, based on 1 mol. It is preferable that the catalyst contains at least one compound selected from the group consisting of a conjugated diene compound and a non-conjugated diene compound, because the catalytic activity is further improved. As the conjugated diene compound used at this time, 1,3-butadiene, isoprene and the like can be mentioned as in the case of the monomer for polymerization described later. Further, examples of the non-conjugated diene compound include divinylbenzene, diisopropenylbenzene, triisopropenylbenzene, 1,4-vinylhexadiene, ethylidene norbornene and the like.

The catalyst composition containing the mixture of components (a) to (c) as a main component is, for example, components (a) to (c) dissolved in a solvent, and a conjugated diene compound and a non-containing component which are added as necessary. It can be prepared by reacting at least one compound selected from the group consisting of conjugated diene compounds. In addition, the order of addition of each component at the time of preparation may be arbitrary. However, it is preferable to preliminarily mix, react, and age each component from the viewpoint of improving the polymerization activity and shortening the polymerization initiation induction period. The aging temperature is preferably 0 to 100°C, more preferably 20 to 80°C. If it is lower than 0°C, aging tends to be insufficient. On the other hand, when the temperature exceeds 100°C, the catalytic activity tends to decrease and the molecular weight distribution tends to broaden. The aging time is not particularly limited. The components may be brought into contact with each other in a line before being added to the polymerization reaction tank. In this case, the aging time is 0.5 minutes or more. The prepared catalyst is stable for several days.

The conjugated diene-based polymer used in producing the modified conjugated diene-based polymer in the present invention, the ratio of the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by gel permeation chromatography, that is, The molecular weight distribution (Mw/Mn) is preferably 3.5 or less, more preferably 3.0 or less, and further preferably 2.5 or less. When the molecular weight distribution exceeds 3.5, rubber properties such as breaking properties and low heat buildup tend to be deteriorated. On the other hand, the lower limit of the molecular weight distribution is not particularly limited. In the present specification, the molecular weight distribution (Mw/Mn) means a value calculated by the ratio of the weight average molecular weight and the number average molecular weight (weight average molecular weight/number average molecular weight). Here, the weight average molecular weight of the conjugated diene polymer is a polystyrene equivalent weight average molecular weight measured by the GPC method (Gel Permeation Chromatography method). The number average molecular weight of the conjugated diene polymer is the polystyrene equivalent number average molecular weight measured by the GPC method.

The vinyl content and the cis-1,4-bond content of the conjugated diene polymer can be easily adjusted by controlling the polymerization temperature. The Mw/Mn can be easily adjusted by controlling the molar ratio of the components (a) to (c).

Further, the Mooney viscosity (ML _1+4, 100° C.) at 100° C. of the conjugated diene polymer is preferably in the range of 5 to 50, and more preferably 10 to 40. If it is less than 5, mechanical properties after vulcanization, abrasion resistance and the like may be deteriorated, while if it is more than 50, the processability at the time of kneading the modified conjugated diene polymer after carrying out the modification reaction may be poor. It may decrease. The Mooney viscosity can be easily adjusted by controlling the molar ratio of the components (a) to (c).
The Mooney viscosity (ML ₁₊₄ , 100° C.) is a value obtained by the measuring method described in Examples below.

Further, the content of 1,2-vinyl bonds (1,2-vinyl bond amount) of the conjugated diene-based polymer is preferably 0.5% by mass or less, and 0.4% by mass or less. More preferably, it is even more preferably 0.3% by mass or less. If it exceeds 0.5% by mass, rubber physical properties such as breaking properties tend to deteriorate. The 1,2-vinyl bond content of the conjugated diene polymer is preferably 0.001 mass% or more, more preferably 0.01 mass% or more. In the present specification, the 1,2-vinyl bond content is a value calculated from the signal intensity measured by NMR analysis.

The alkoxysilane compound used in the modification step (A) (hereinafter, also referred to as “modifying agent”) has two or more reactive groups containing an alkoxysilyl group. The reactive group other than the alkoxysilyl group is not particularly limited in type, and includes, for example, (f); epoxy group, (g); isocyanate group, (h); carbonyl group, and (i); cyano group. At least one functional group selected from the group is preferred. That is, the alkoxysilane compound has at least one functional group selected from the group consisting of (f); epoxy group, (g); isocyanate group, (h); carbonyl group, and (i); cyano group. Inclusion is also one of the preferred embodiments of the present invention. The alkoxysilane compound may be a partial condensate, or a mixture of the alkoxysilane compound and the partial condensate.

Here, the “partial condensate” refers to a part (that is, not all) of SiOR (OR represents an alkoxy group) of the alkoxysilane compound, which is SiOSi-bonded by condensation. The conjugated diene polymer used in the modification reaction preferably has at least 10% of polymer chains having living property.

Specific examples of the alkoxysilane compound include (f); 2-glycidoxyethyltrimethoxysilane, 2 as an alkoxysilane compound containing an epoxy group (hereinafter, also referred to as “epoxy group-containing alkoxysilane compound”). -Glycidoxyethyltriethoxysilane, (2-glycidoxyethyl)methyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, (3-glycidoxypropyl)methyl Dimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl(methyl)dimethoxysilane Among them, 3-glycidoxypropyltrimethoxysilane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane are more preferable.

Examples of (g); an alkoxysilane compound containing an isocyanate group (hereinafter, also referred to as “isocyanate group-containing alkoxysilane compound”) include, for example, 3-isocyanatepropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, Examples thereof include 3-isocyanatepropylmethyldiethoxysilane and 3-isocyanatepropyltriisopropoxysilane. Among them, 3-isocyanatepropyltrimethoxysilane is particularly preferable.

Moreover, (h); as the alkoxysilane compound containing a carbonyl group (hereinafter, also referred to as “carbonyl group-containing alkoxysilane compound”), 3-methacryloyloxypropyltriethoxysilane, 3-methacryloyloxypropyltrimethoxysilane Examples thereof include silane, 3-methacryloyloxypropylmethyldiethoxysilane, and 3-methacryloyloxypropyltriisopropoxysilane. Among them, 3-methacryloyloxypropyltrimethoxysilane is particularly preferable.

Furthermore, (i); as the alkoxysilane compound containing a cyano group (hereinafter, also referred to as "cyano group-containing alkoxysilane compound"), 3-cyanopropyltriethoxysilane, 3-cyanopropyltrimethoxysilane, 3- Examples thereof include cyanopropylmethyldiethoxysilane and 3-cyanopropyltriisopropoxysilane. Among them, 3-cyanopropyltrimethoxysilane is particularly preferable.

Among these, as the above-mentioned modifier, 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-methacryloyloxypropyl Trimethoxysilane and 3-cyanopropyltrimethoxysilane are particularly preferable, and 3-glycidoxypropyltrimethoxysilane is most preferable.
These modifiers may be used alone or in combination of two or more. Further, a partial condensate of the above-mentioned alkoxysilane compound can also be used.

In the modification reaction of the modification step (A), the amount of the alkoxysilane compound used is preferably 0.01 to 200 mol, and preferably 0.1 to 150 mol, per 1 mol of the component (a). More preferably. If it is less than 0.01 mol, the progress of the modification reaction will not be sufficient and the dispersibility of the filler will not be sufficiently improved, so that mechanical properties after vulcanization, abrasion resistance and low heat buildup will be sufficiently obtained. There is a possibility that there is no. On the other hand, even if it is used in excess of 200 moles, the modification reaction may be saturated, and in that case, the cost for the use will be extra. The method of adding the modifier is not particularly limited, and examples thereof include a method of adding all at once, a method of adding in portions, a method of continuously adding, and the like. Among them, the method of adding all at once is preferable. ..

The modification reaction is preferably carried out in a solution, and as this solution, the solution containing the unreacted monomer used at the time of polymerization can be used as it is. The form of the denaturing reaction is not particularly limited, and it may be carried out using a batch type reactor, or may be carried out continuously using a device such as a multistage continuous reactor or an in-line mixer. Further, this modification reaction is preferably carried out after the completion of the polymerization reaction and before the solvent removal treatment, the water treatment, the heat treatment, the various operations necessary for polymer isolation, and the like.

The temperature of the modification reaction may be the same as the polymerization temperature when polymerizing the conjugated diene polymer. Specifically, 20 to 100°C is preferable, and 30 to 90°C is more preferable. If the temperature is lower than 20°C, the viscosity of the polymer tends to increase, and if it exceeds 100°C, the polymerization active terminal may be deactivated.

Further, the reaction time in the modification reaction is preferably 5 minutes to 5 hours, and more preferably 15 minutes to 1 hour. In the condensation step (B), after introducing an alkoxysilane compound residue at the active terminal of the polymer, a known antioxidant or reaction terminator may be added, if desired.

In the modifying step (A), in addition to the modifying agent, in the condensation step (B), a condensing reaction with an alkoxysilane compound residue which is a modifying agent introduced at the active terminal is further added. Preferably. Specifically, it is preferable to add a functional group-introducing agent. The functional group-introducing agent can improve the abrasion resistance of the modified conjugated diene polymer.

The functional group-introducing agent is not particularly limited as long as it does not substantially cause a direct reaction with the active terminal and remains as an unreacted product in the reaction system, for example, an alkoxysilane compound used as the modifying agent. Different alkoxysilane compounds, that is, alkoxysilane compounds containing at least one functional group selected from the group consisting of (j); amino group, (k); imino group, and (l); mercapto group. Is preferred. The alkoxysilane compound used as the functional group-introducing agent may be a partial condensate, or may be a mixture of a partial condensate which is not a partial condensate of the alkoxysilane compound used as a functional group-introducing agent. May be.

Specific examples of the functional group-introducing agent include (j); 3-dimethylaminopropyl(triethoxy)silane as an alkoxysilane compound containing an amino group (hereinafter, also referred to as “amino group-containing alkoxysilane compound”), 3-dimethylaminopropyl(trimethoxy)silane, 3-diethylaminopropyl(triethoxy)silane, 3-diethylaminopropyl(trimethoxy)silane, 2-dimethylaminoethyl(triethoxy)silane, 2-dimethylaminoethyl(trimethoxy)silane, 3- Dimethylaminopropyl(diethoxy)methylsilane, 3-dibutylaminopropyl(triethoxy)silane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, aminophenyltrimethoxysilane, aminophenyltriethoxysilane, 3-(N -Methylamino)propyltrimethoxysilane, 3-(N-methylamino)propyltriethoxysilane, 3-(1-pyrrolidinyl)propyl(triethoxy)silane, 3-(1-pyrrolidinyl)propyl(trimethoxy)silane, N -(1,3-Dimethylbutylidene)-3-(triethoxysilyl)-1-propanamine, N-(1-methylethylidene)-3-(triethoxysilyl)-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 trimethoxysilyl compounds corresponding to these triethoxysilyl compounds, Examples thereof include a methyldiethoxysilyl compound, an ethyldiethoxysilyl compound, a methyldimethoxysilyl compound, an ethyldimethoxysilyl compound, and the like. Among them, 3-diethylaminopropyl(triethoxy)silane, 3-dimethylaminopropyl(triethoxy)silane, 3 -Aminopropyltriethoxysilane, N-(1-methylpropylidene)-3-(triethoxysilyl)-1-propanamine, N-(1,3-dimethylbutylidene)-3-(triethoxysilyl)- 1-Propaneamine is particularly preferred.

Further, (k): 3-(1-hexamethyleneimino)propyl(triethoxy)silane, 3-(1) as an imino group-containing alkoxysilane compound (hereinafter, also referred to as “imino group-containing alkoxysilane compound”) -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-heptamethyleneimino)propyl(triethoxy)silane, 3-(1-dodecamethyleneimino)propyl(triethoxy)silane, 3-( 1-hexamethyleneimino)propyl(diethoxy)methylsilane, 3-(1-hexamethyleneimino)propyl(diethoxy)ethylsilane, 1-[3-(triethoxysilyl)propyl]-4,5-dihydroimidazole, 1 -[3-(Trimethoxysilyl)propyl]-4,5-dihydroimidazole, 3-[10-(triethoxysilyl)decyl]-4-oxazoline, N-(3-isopropoxysilylpropyl)-4,5 -Dihydroimidazole and N-(3-methyldiethoxysilylpropyl)-4,5-dihydroimidazole are mentioned as suitable ones. Among these, 3-(1-hexamethyleneimino)propyl(triethoxy)silane, 3-(1-hexamethyleneimino)propyl(triethoxy)silane, (1-hexamethyleneimino)methyl(trimethoxy)silane, 1-[3-(triethoxysilyl)propyl]-4,5-dihydroimidazole, 1- [3-(Trimethoxysilyl)propyl]-4,5-dihydroimidazole and N-(3-triethoxysilylpropyl)-4,5-dihydroimidazole are more preferred.

Further, as (l); an alkoxysilane compound containing a mercapto group (hereinafter, also referred to as "mercapto group-containing alkoxysilane compound"), 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 2-mercapto. Examples include ethyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 3-mercaptopropyl(diethoxy)methylsilane, 3-mercaptopropyl(monoethoxy)dimethylsilane, mercaptophenyltrimethoxysilane, and mercaptophenyltriethoxysilane. Among them, 3-mercaptopropyltriethoxysilane is particularly preferable.

Among these, as the functional group-introducing agent, 3-diethylaminopropyl(triethoxy)silane, 3-dimethylaminopropyl(triethoxy)silane, 3-aminopropyltriethoxysilane, 3-(1-hexamethyleneimino)propyl (Triethoxy)silane, N-(1-methylpropylidene)-3-(triethoxysilyl)-1-propanamine, N-(1,3-dimethylbutylidene)-3-(triethoxysilyl)-1- Propanamine, 3-(1-hexamethyleneimino)propyl(triethoxy)silane, (1-hexamethyleneimino)methyl(trimethoxy)silane, 1-[3-(triethoxysilyl)propyl]-4,5-dihydroimidazole , 1-[3-(trimethoxysilyl)propyl]-4,5-dihydroimidazole, N-(3-triethoxysilylpropyl)-4,5-dihydroimidazole, 3-mercaptopropyltriethoxysilane are particularly preferable, Most preferred is 3-aminopropyltriethoxysilane.
These functional group-introducing agents may be used alone or in combination of two or more kinds.

When an alkoxysilane compound is used as the functional group-introducing agent, the amount used is preferably 0.01 to 200 mol, and more preferably 0.1 to 150 mol, per 1 mol of the component (a). If the amount is less than 0.01 mol, the progress of the condensation reaction will not be sufficient and the dispersibility of the filler will not be sufficiently improved, so that mechanical properties after vulcanization, abrasion resistance, and low heat buildup may be inferior. .. On the other hand, even if it is used in excess of 200 mol, the condensation reaction may be saturated, and in that case, the cost for the use will be extra.

The time for adding the functional group-introducing agent is after the introduction of the alkoxysilane compound residue into the active terminal of the conjugated diene polymer in the modification step (A) and the condensation reaction in the condensation step (B). Is preferably started before. If added after the start of the condensation reaction, the functional group-introducing agent may not be uniformly dispersed and the catalytic performance may be deteriorated. Specifically, the addition timing of the functional group-introducing agent is preferably 5 minutes to 5 hours after the start of the modification reaction, and more preferably 15 minutes to 1 hour after the start of the modification reaction.

When the alkoxysilane compound having the functional group is used as the functional group-introducing agent, the conjugated diene-based polymer having an active terminal and the substantially stoichiometric amount of the modifier added to the reaction system are A modification reaction is caused to introduce an alkoxysilyl group into substantially all of the active terminals, and by further adding the above-mentioned functional group-introducing agent, more alkoxysilane compound residue than the equivalent amount of the active terminals of this conjugated diene polymer remains. The group will be introduced.

The condensation reaction between the alkoxysilyl groups may occur between the free alkoxysilane compound and the alkoxysilyl group at the end of the conjugated diene polymer, or in some cases, between the alkoxysilyl groups at the end of the conjugated diene polymer. From the viewpoint of reaction efficiency, the reaction between free alkoxysilane compounds is not preferable. Therefore, when an alkoxysilane compound is newly added as a functional group-introducing agent, the hydrolyzability of the alkoxysilyl group is lower than that of the alkoxysilyl group introduced at the end of the conjugated diene polymer. preferable.

For example, a compound containing a highly hydrolyzable trimethoxysilyl group is used as the alkoxysilane compound used for the reaction with the active end of the conjugated diene polymer, and the alkoxysilane compound newly added as a functional group-introducing agent is used. Is preferably a combination using a compound containing an alkoxysilyl group (for example, a triethoxysilyl group) having a lower hydrolyzability than the trimethoxysilyl group-containing compound. Conversely, for example, a compound containing a triethoxysilyl group is used as the alkoxysilane compound used for the reaction with the active end of the conjugated diene polymer, and the alkoxysilane compound newly added as the functional group-introducing agent is trimethoxysilyl. If it is a compound containing a group, the reaction efficiency may decrease.

In the condensation step (B), the presence of a condensation catalyst containing at least one element selected from the group consisting of elements included in Groups 4, 12, 13, 14, and 15 of the Periodic Table. Below is a step of subjecting the residue of the alkoxysilane compound introduced to the active terminal to a condensation reaction.

The condensation catalyst is not particularly limited as long as it contains at least one element selected from the group consisting of elements included in Groups 4, 12, 13, 14, and 15 of the periodic table. Although not included, for example, titanium (Ti) (Group 4), tin (Sn) (Group 14), zirconium (Zr) (Group 4), bismuth (Bi) (Group 15) and aluminum (Al) ( It is preferable that it contains at least one element selected from the group consisting of Group 13).

Specific examples of the condensation catalyst include tin (Sn)-containing condensation catalysts such as bis(n-octanoate)tin, bis(2-ethylhexanoate)tin, bis(laurate)tin, and bis(naphthoenate). ) Tin, bis(stearate) tin, bis(oleate) tin, dibutyltin diacetate, dibutyltin di-n-octanoate, dibutyltin di2-ethylhexanoate, dibutyltin dilaurate, dibutyltin malate, dibutyltin bis(benzyl maleate), Dibutyltin bis(2-ethylhexylmalate), di-n-octyltin diacetate, di-n-octyltin di-n-octanoate, di-n-octyltin di2-ethylhexanoate, di-n-octyltin dilaurate, di-n-octyltin dimalate Rate, di n-octyl tin bis (benzyl malate), di n-octyl tin bis (2-ethylhexyl malate) and the like.

Examples of the condensation catalyst containing zirconium (Zr) include tetraethoxyzirconium, tetra-n-propoxyzirconium, tetra-i-propoxyzirconium, tetra-n-butoxyzirconium, tetrasec-butoxyzirconium, tetra-tert-butoxyzirconium, and tetra(2- Ethylhexyl oxide) zirconium, zirconium tributoxystearate, zirconium tributoxyacetylacetonate, zirconium dibutoxybis(acetylacetonate), zirconium tributoxyethylacetoacetate, zirconium butoxyacetylacetonate bis(ethylacetoacetate), zirconium tetrakis( Acetylacetonate), zirconium diacetylacetonate bis(ethylacetoacetate), bis(2-ethylhexanoate) zirconium oxide, bis(laurate) zirconium oxide, bis(naphthate) zirconium oxide, bis(stearate) zirconium oxide, Bis(oleate)zirconium oxide, bis(linoleate)zirconium oxide, tetrakis(2-ethylhexanoate)zirconium, tetrakis(laurate)zirconium, tetrakis(naphthate)zirconium, tetrakis(stearate)zirconium, tetrakis(oleate)zirconium, Tetrakis (linoleate) zirconium etc. are mentioned.

Examples of the condensation catalyst containing bismuth (Bi) include tris(2-ethylhexanoate)bismuth, tris(laurate)bismuth, tris(naphthate)bismuth, tris(stearate)bismuth, tris(oleate)bismuth, tris( Linoleate) bismuth and the like.

Examples of the condensation catalyst containing aluminum (Al) include triethoxyaluminum, tri-n-propoxyaluminum, tri-i-propoxyaluminum, tri-n-butoxyaluminum, trisec-butoxyaluminum, tritert-butoxyaluminum, tri(2-). Ethylhexyl oxide) aluminum, aluminum dibutoxystearate, aluminum dibutoxyacetylacetonate, aluminum butoxybis(acetylacetonate), aluminum dibutoxyethylacetoacetate, aluminum tris(acetylacetonate), aluminum tris(ethylacetoacetate), Examples thereof include tris(2-ethylhexanoate) aluminum, tris(laurate) aluminum, tris(naphthate) aluminum, tris(stearate) aluminum, tris(oleate) aluminum, and tris(linoleate) aluminum.

As a condensation catalyst containing titanium (Ti), for example, tetramethoxytitanium, tetraethoxytitanium, tetra-n-propoxytitanium, tetra-i-propoxytitanium, tetra-n-butoxytitanium, tetra-n-butoxytitanium oligomer, tetrasec-butoxytitanium. , Tetra-tert-butoxytitanium, tetra(2-ethylhexyl oxide) titanium, bis(octanediolate)bis(2-ethylhexyl oxide) titanium, tetra(octanediolate) titanium, titanium lactate, titanium dipropoxybis(triethanolamit) ), titanium dibutoxybis(triethanolaminate), titanium tributoxystearate, titanium tripropoxystearate, titanium tripropoxyacetylacetonate, titanium dipropoxybis(acetylacetonate), titanium tripropoxyethylacetoacetate, Titanium propoxyacetylacetonate bis(ethylacetoacetate), titanium tributoxyacetylacetonate, titanium dibutoxybis(acetylacetonate), titanium tributoxyethylacetoacetate, titanium butoxyacetylacetonate bis(ethylacetoacetate), titanium tetrakis (Acetylacetonate), titanium diacetylacetonate bis(ethylacetoacetate), bis(2-ethylhexanoate) titanium oxide, bis(laurate) titanium oxide, bis(naphthate) titanium oxide, bis(stearate) titanium oxide , Bis(oleate)titanium oxide, bis(linoleate)titanium oxide, tetrakis(2-ethylhexanoate)titanium, tetrakis(laurate)titanium, tetrakis(naphthate)titanium, tetrakis(stearate)titanium, tetrakis(oleate)titanium , Tetrakis(linoleate)titanium and the like.

Among these, the condensation catalyst containing titanium (Ti) is more preferable as the condensation catalyst. Among the condensation catalysts containing titanium (Ti), alkoxides, carboxylates or acetylacetonate complex salts of titanium (Ti) are more preferable. Particularly preferred is tetra-i-propoxytitanium (tetraisopropyl titanate). Use of a condensation catalyst containing titanium (Ti) to more effectively accelerate the condensation reaction of the residue of the alkoxysilane compound used as a modifier and the residue of the alkoxysilane compound used as a functional group-introducing agent. It is possible to obtain a modified conjugated diene-based polymer having excellent processability, low temperature characteristics and abrasion resistance. As described above, it is also one of the preferred embodiments of the present invention that the condensation catalyst contains titanium (Ti).

The amount of the condensation catalyst used is such that the number of moles of the various compounds that can be used as the condensation catalyst is 0.1 to 10 moles based on 1 mole of the total amount of alkoxysilyl groups present in the reaction system. Is preferable, and 0.3-5 mol is particularly preferable. If it is less than 0.1 mol, the condensation reaction may not proceed sufficiently. On the other hand, even if it is used in excess of 10 moles, the effect as a condensation catalyst may be saturated, and in that case, the cost for the use will be extra.

The condensation catalyst may be added before the modification reaction, but is preferably added after the modification reaction and before the start of the condensation reaction. If added before the modification reaction, a direct reaction with the active end may occur, and the alkoxysilyl group may not be introduced into the active end. Further, when added after the start of the condensation reaction, the condensation catalyst may not be uniformly dispersed and the catalytic performance may be deteriorated. Specifically, the time for adding the condensation catalyst is preferably 5 minutes to 5 hours after the start of the modification reaction, and more preferably 15 minutes to 1 hour after the start of the modification reaction.

The condensation reaction in the condensation step (B) is preferably performed in an aqueous solution, and the temperature during the condensation reaction is preferably 85 to 180°C, more preferably 100 to 170°C, and more preferably 110 to 150°C. Is particularly preferable. If the temperature during the condensation reaction is less than 85° C., the condensation reaction may not proceed sufficiently and the condensation reaction may not be completed. In that case, the resulting modified conjugated diene polymer may change with time. May occur and cause a quality problem. On the other hand, if it exceeds 180° C., the aging reaction of the polymer may proceed and the physical properties may be deteriorated.

The pH of the aqueous solution in which the condensation reaction is carried out is preferably 9 to 14, and more preferably 10 to 12. By setting the pH of the aqueous solution in such a range, the condensation reaction is promoted, and the stability of the modified conjugated diene-based polymer over time can be improved. If the pH is less than 9, the condensation reaction may not proceed sufficiently and the condensation reaction may not be completed. In that case, the modified conjugated diene-based polymer obtained may change over time, resulting in poor quality. There is a risk of problems. On the other hand, when the pH of the aqueous solution in which the condensation reaction is carried out exceeds 14, a large amount of the alkali-derived component remains in the modified conjugated diene polymer after isolation, which may make removal difficult.

The reaction time of the condensation reaction is preferably 5 minutes to 10 hours, more preferably about 15 minutes to 5 hours. If it is less than 5 minutes, the condensation reaction may not be completed. On the other hand, even if it exceeds 10 hours, the condensation reaction may be saturated. The pressure in the reaction system during the condensation reaction is preferably 0.01 to 20 MPa, more preferably 0.05 to 10 MPa.

The form of the condensation reaction is not particularly limited, and may be performed using a batch reactor or may be performed continuously using an apparatus such as a multistage continuous reactor. Further, the solvent removal may be carried out simultaneously with this condensation reaction.

After carrying out the condensation reaction as described above, a conventionally known post-treatment can be carried out to obtain the target modified conjugated diene polymer.

The modified conjugated diene-based polymer has a Mooney viscosity (ML ₁₊₄ (125° C.)) of preferably 10 to 150, more preferably 20 to 100. When the Mooney viscosity (ML ₁₊₄ (125° C.)) is less than 10, rubber physical properties such as breaking properties may be deteriorated. On the other hand, when the Mooney viscosity (ML ₁₊₄ (125° C.)) exceeds 150, workability is deteriorated and it may be difficult to knead with the compounding agent.
The Mooney viscosity (ML ₁₊₄ , 125° C.) is a value obtained by the measuring method described in Examples below.

The molecular weight distribution (Mw/Mn) of the modified conjugated diene-based polymer is preferably 3.5 or less, more preferably 3.0 or less, and further preferably 2.5 or less. .. When the molecular weight distribution is more than 3.5, rubber properties such as breaking properties and low heat buildup tend to be deteriorated. Here, the weight average molecular weight (Mw) of the modified conjugated diene-based polymer is a polystyrene equivalent weight average molecular weight measured by the GPC method (Gel Permeation Chromatography method). The number average molecular weight (Mn) of the modified conjugated diene polymer is the polystyrene equivalent number average molecular weight measured by the GPC method.

Further, the cold flow value (mg/min) of the modified conjugated diene polymer is preferably 1.0 or less, more preferably 0.8 or less. If the cold flow value is more than 1.0, the shape stability of the polymer during storage may deteriorate. In addition, in this specification, the cold flow value (mg/min) is a value calculated by the measuring method described later.

Furthermore, the evaluation value of the temporal stability of the modified conjugated diene polymer is preferably 0 to 5, and more preferably 0 to 2. If this evaluation value exceeds 5, the polymer may change over time during storage. In addition, in this specification, the temporal stability is a value calculated by a measuring method described later.

Moreover, the glass transition temperature of the modified conjugated diene polymer is preferably −40° C. or lower. The temperature is more preferably −43° C. or lower, further preferably −46° C. or lower, and particularly preferably −50° C. or lower. If the glass transition temperature exceeds −40° C., the low temperature characteristics required for a studless tire may not be sufficiently secured. On the other hand, the lower limit of the glass transition temperature is not particularly limited.
Here, the glass transition temperature of the modified conjugated diene polymer can be measured by the measuring method described in Examples below.

The rubber component may contain a rubber other than the natural rubber and the modified conjugated diene polymer. Examples of the other rubbers include isoprene rubber (IR), deproteinized natural rubber (DPNR), high-purity natural rubber (UPNR), isoprene-based diene rubber such as modified natural rubber; butadiene rubber (BR), styrene-butadiene rubber (SBR). ), styrene isoprene butadiene rubber (SIBR), chloroprene rubber (CR), acrylonitrile butadiene rubber (NBR), and other diene rubbers; ethylene propylene diene rubber (EPDM), butyl rubber (IIR), halogenated butyl rubber (X-IIR), etc. And non-diene rubbers.
Examples of the modified natural rubber include epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), and grafted natural rubber.

Regarding the rubber composition in the summer tire of the present invention, the content of silica is 1 part by mass or more based on 100 parts by mass of the rubber component. Thus, the rubber composition in the summer tire of the present invention contains a predetermined amount of silica. The content of silica is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and further preferably 20 parts by mass or more with respect to 100 parts by mass of the rubber component. Further, it is preferably 100 parts by mass or less, more preferably 80 parts by mass or less, further preferably 70 parts by mass or less, and particularly preferably 60 parts by mass or less. When the content of silica is less than 1 part by mass relative to 100 parts by mass of the rubber component, the performance of the modified conjugated diene polymer may not be sufficiently exerted in the summer tire, resulting in sufficient fuel economy and steering stability. There is a tendency to not exhibit the sex. On the other hand, if it exceeds 100 parts by mass, the amount of the filler becomes too large, and it becomes difficult to disperse the filler, and wear resistance, low fuel consumption performance, and steering stability tend to deteriorate. Further, the workability of rubber may be significantly deteriorated.

In the rubber composition of the studless tire of the present invention, the content of silica is 1 part by mass or more based on 100 parts by mass of the rubber component. As described above, the rubber composition of the present invention contains a predetermined amount of silica. The content of silica is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, further preferably 30 parts by mass or more, particularly preferably 40 parts by mass or more, and particularly preferably 50 parts by mass or more with respect to 100 parts by mass of the rubber component. Is most preferred. Further, it is preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and further preferably 75 parts by mass or less. When the content of silica is less than 1 part by mass based on 100 parts by mass of the rubber component, the performance of the modified conjugated diene polymer may not be sufficiently exhibited in the studless tire, and the hardness is sufficiently increased at a low temperature. Cannot be suppressed, and there is a tendency that sufficient performance on ice and snow cannot be exhibited. Moreover, there is a tendency that sufficient fuel economy performance cannot be exhibited. On the other hand, if it exceeds 100 parts by mass, the amount of the filler becomes too large, and it becomes difficult to disperse the filler, and wear resistance, low fuel consumption performance, and performance on ice and snow tend to deteriorate. Further, the workability of rubber may be significantly deteriorated.

The silica is not particularly limited, and for example, dry process silica (anhydrous silica), wet process silica (hydrous silica), and the like can be used. Wet method silica (hydrous silica) is preferable because it has many silanol groups.

The nitrogen adsorption specific surface area (N ₂ SA) of silica is preferably 40 m ² /g or more, more preferably 80 m ² /g or more, still more preferably 100 m ² /g or more, and particularly preferably 110 m ² /g. If it is less than 40 m ² /g, sufficient reinforcing properties and breaking properties may not be obtained, and sufficient abrasion resistance and performance on ice and snow may not be obtained. The N ₂ SA of silica is preferably 300 m ² /g or less, more preferably 200 m ² /g or less, still more preferably 185 m ² /g or less, and particularly preferably 180 m ² /g or less. If it exceeds 300 m ² /g, silica may be difficult to disperse, wear resistance and fracture properties may be deteriorated, and sufficient low temperature properties required for studless tires may not be ensured.
The N ₂ SA of silica is a value measured by the BET method according to ASTM D3037-93.

The average primary particle diameter of silica is preferably 25 nm or less, more preferably 22 nm or less, and further preferably 17 nm or less. The lower limit of the average primary particle diameter is not particularly limited, but is preferably 3 nm or more, more preferably 5 nm or more, and further preferably 7 nm or more. When the average primary particle diameter of silica is within such a range, the dispersibility of silica can be further improved, and the reinforcing property, fracture property, and abrasion resistance can be further improved.
The average primary particle diameter of silica can be determined by observing with a transmission or scanning electron microscope, measuring 400 or more primary particles of silica observed in the visual field, and averaging the measured values.

When carbon black is blended, the rubber composition in the present invention is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, and further preferably 7 parts by mass or more with respect to 100 parts by mass of the rubber component. The content is preferably 70 parts by mass or less, more preferably 65 parts by mass or less, further preferably 40 parts by mass or less, and particularly preferably 20 parts by mass or less.

The carbon black is not particularly limited, and general ones that are compounded in the rubber composition for the base tread can be used, and examples thereof include GPF, FEF, HAF, ISAF, SAF and the like. Among them, ISAF, SAF and HAF are preferable, and ISAF is more preferable.

Nitrogen adsorption specific surface area _(N 2 SA) of carbon black is preferably not less than ^{50 m} 2 / g, more preferably at least ^{90m 2 / g, 100m 2 /} g or more, and more 110m ² / g is particularly preferred. If it is less than 50 m ² /g, sufficient reinforcing properties and breaking properties may not be obtained, and sufficient abrasion resistance and performance on ice and snow may not be obtained. The _N 2 SA is preferably 250 meters ² / g or less, more preferably 230 m ² / g, still more preferably 180 m ² / g or less, and particularly preferably 130m ² / g. If it exceeds 250 m ² /g, it will be difficult to disperse it, and the abrasion resistance and fracture characteristics tend to deteriorate.
The N ₂ SA of carbon black is measured according to JIS K 6217-2:2001.

The dibutyl phthalate oil absorption (DBP) of carbon black is preferably 50 ml/100 g or more, more preferably 100 ml/100 g or more. If it is less than 50 ml/100 g, sufficient reinforcing properties and breaking properties may not be obtained, and sufficient abrasion resistance and performance on ice and snow may not be obtained. The DBP of carbon black is preferably 200 ml/100 g or less, more preferably 135 ml/100 g or less. If it exceeds 200 ml/100 g, the workability, wear resistance, and fracture characteristics may deteriorate.
The DBP of carbon black is measured according to JIS K 6217-4:2001.

The rubber composition in the present invention preferably further contains a silane coupling agent. As the silane coupling agent, any silane coupling agent that has been conventionally used in combination with silica in the rubber industry can be used. For example, a sulfide-based compound such as bis(3-triethoxysilylpropyl)disulfide, 3 -Mercapto type such as mercaptopropyltrimethoxysilane, vinyl type such as vinyltriethoxysilane, amino type such as 3-aminopropyltriethoxysilane, glycidoxy type of γ-glycidoxypropyltriethoxysilane, 3-nitropropyltrimethoxysilane Examples thereof include nitro-based compounds such as methoxysilane and chloro-based compounds such as 3-chloropropyltrimethoxysilane. Among them, sulfides are preferable, and bis(3-triethoxysilylpropyl)disulfide is more preferable.

The content of the silane coupling agent is preferably 1 part by mass or more, and more preferably 3 parts by mass or more with respect to 100 parts by mass of silica. If the amount is less than 1 part by mass, sufficient reinforcing property and breaking property may not be obtained, and sufficient abrasion resistance and performance on ice and snow may not be obtained. The content of the silane coupling agent is preferably 15 parts by mass or less, more preferably 12 parts by mass or less. If it exceeds 15 parts by mass, the effect commensurate with the increase in cost tends not to be obtained.

Further, the rubber composition in the present invention preferably further contains oil. By compounding the oil, the hardness of the rubber is lowered and a better performance on ice and snow can be obtained. Thus, it is also one of the preferred embodiments of the present invention that the rubber composition of the present invention further contains an oil. Further, it is one of the particularly preferable embodiments that the oil content described below is contained.

As the oil, for example, process oil, vegetable oil and fat, a mixture thereof and the like can be used. Examples of the process oil include paraffin type process oil, naphthene type process oil, aromatic type process oil (aroma oil) and the like. As vegetable oils and fats, castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, coconut oil, peanut water, rosin, pine oil, pine tar, tall oil, corn oil, sesame oil, Beni flower oil, sesame oil, Examples include olive oil, sunflower oil, palm kernel oil, camellia oil, jojoba oil, macadamia nut oil, tung oil and the like. Of these, aroma oil is particularly preferable.

Regarding the rubber composition in the summer tire of the present invention, the content of oil is preferably 1 part by mass or more, and more preferably 3 parts by mass or more, based on 100 parts by mass of the rubber component. The oil content is preferably 80 parts by mass or less, more preferably 40 parts by mass or less, further preferably 20 parts by mass or less, and particularly preferably less than 10 parts by mass. Within the above range, the effects of the present invention can be more favorably obtained.

Regarding the rubber composition in the studless tire of the present invention, the content of oil is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and further preferably 15 parts by mass or more with respect to 100 parts by mass of the rubber component. .. If the amount is less than 5 parts by mass, sufficient performance on ice and snow may not be obtained, or the flexibility required for a studless tire may not be secured. The content of oil is preferably 80 parts by mass or less, more preferably 60 parts by mass or less, further preferably 50 parts by mass or less, particularly preferably 40 parts by mass or less, and most preferably 30 parts by mass or less. If it exceeds 80 parts by mass, abrasion resistance and fracture characteristics may deteriorate. Further, the workability of rubber may be significantly deteriorated.
Above all, the silica content is 20 to 80 parts by mass, and the oil content is 10 to 50 parts by mass with respect to 100 parts by mass of the rubber component. By using a compounding system, it is possible to improve the fuel economy performance and the performance on snow and ice in a well-balanced manner, and further to improve the rubber workability particularly.

In addition to the above components, the rubber composition of the present invention contains, in addition to the components described above, compounding agents generally used in the tire industry, such as wax, stearic acid, zinc oxide, antioxidants, vulcanizing agents such as sulfur, and vulcanizing agents. Materials such as a sulfur accelerator may be appropriately mixed.

Examples of the vulcanization accelerator include sulfenamide-based, thiazole-based, thiuram-based, thiourea-based, guanidine-based, dithiocarbamic acid-based, aldehyde-amine-based or aldehyde-ammonia-based, imidazoline-based, or xanthate-based vulcanization accelerators. Agents and the like. These vulcanization accelerators may be used alone or in combination of two or more kinds. Among these, a sulfenamide-based vulcanization accelerator is preferable, and a sulfenamide-based vulcanization accelerator and a guanidine-based vulcanization accelerator such as diphenylguanidine are preferably used because the effect of the present invention can be more suitably obtained. The combined use is more preferable.

Examples of the sulfenamide-based vulcanization accelerator include N-tert-butyl-2-benzothiazolyl sulfenamide (TBBS), N-cyclohexyl-2-benzothiazolyl sulfenamide (CBS), N, Examples thereof include N-dicyclohexyl-2-benzothiazolylsulfenamide (DCBS). Among them, CBS is preferable, and it is more preferable to use CBS in combination with a guanidine vulcanization accelerator such as diphenylguanidine, because the effect of the present invention can be more suitably obtained.

The rubber composition in the present invention is manufactured by a general method. That is, components other than a vulcanizing agent and a vulcanization accelerator (rubber component containing natural rubber and a modified conjugated diene polymer and silica, and a rubber kneading device such as a Banbury mixer, a kneader, and an open roll, and, if necessary, other Component) is blended and kneaded, and then the resulting kneaded product is further blended with a vulcanizing agent and a vulcanization accelerator, kneaded, and then vulcanized. The rubber composition is used for a base tread of a summer tire or a studless tire.

The summer tire or studless tire of the present invention is produced by a usual method using the above rubber composition. That is, a rubber composition containing the above components is extruded in accordance with the shape of the base tread in the unvulcanized stage, together with other tire members, by molding in a usual manner on a tire molding machine, Form an unvulcanized tire. A tire can be manufactured by heating and pressurizing this unvulcanized tire in a vulcanizer. As a result, a summer tire or studless tire having a base tread containing the above-mentioned components can be obtained.
In the summer tire or the studless tire of the present invention, the tread has a multi-layered structure, and therefore, a rubber composition containing the above components is laminated into a predetermined shape in a sheet form at an unvulcanized stage. Alternatively, it can be produced by a method of charging into two or more extruders and forming two or more layers at the head outlet of the extruder.

The summer tire or studless tire of the present invention can be suitably used as a summer tire or a studless tire for passenger cars, large passenger cars, large SUVs, light trucks, trucks, buses and the like.

In addition, in the present invention, the summer tire is a tire that is generally used in a vehicle and is a tire other than a studless tire that is a tire specialized for winter.

The present invention will be specifically described based on Examples, but the present invention is not limited thereto.

<Synthesis Example 1 (Synthesis of Conjugated Diene Polymer)>
In advance, a cyclohexane solution containing 0.18 mmol neodymium versatate, a toluene solution containing 3.6 mmol of methylalumoxane, a toluene solution containing 6.7 mmol of diisobutylaluminum hydride, and 0.36 A catalyst composition (iodine atom/lanthanoid-containing compound (molar ratio)=2.0 obtained by reacting and aging 0.90 mmol of 1,3-butadiene for 60 minutes with a toluene solution containing mmol of trimethylsilyl iodide ) Got. Subsequently, 2.4 kg of cyclohexane and 300 g of 1,3-butadiene were charged into a nitrogen-substituted 5 L autoclave. Then, the catalyst composition was put into the autoclave and polymerized at 30° C. for 2 hours to obtain a polymer solution. The reaction conversion rate of the charged 1,3-butadiene was almost 100%.

Here, in order to measure various physical properties of the conjugated diene polymer (hereinafter, also referred to as “polymer”), that is, before modification, 200 g of the polymer solution was extracted from the polymer solution, and the polymer A methanol solution containing 1.5 g of 2,4-di-tert-butyl-p-cresol was added to the solution to stop the polymerization reaction, and then the solvent was removed by steam stripping, followed by drying with a 110° C. roll. The obtained dried product was used as a polymer.

Various physical properties of the polymer were measured by the following measuring methods. The Mooney viscosity (ML ₁₊₄ , 100° C.) was 12, the molecular weight distribution (Mw/Mn) was 1.6, and the cis-1, The 4-bond content was 99.2 mass %, and the 1,2-vinyl bond content was 0.21 mass %.

[Moonie viscosity (ML ₁₊₄ , 100°C)]
According to JIS K 6300, measurement was performed using an L rotor under conditions of preheating 1 minute, rotor operating time 4 minutes, and temperature 100°C.

[Molecular weight distribution (Mw/Mn)]
A gel permeation chromatograph (trade name: HLC-8120GPC, manufactured by Tosoh Corporation) was used, and a differential refractometer was used as a detector under the following conditions to calculate as a standard polystyrene conversion value.
Column: Product name "GMHHXL", two (manufactured by Tosoh Corporation),
Column temperature: 40°C,
Mobile phase; tetrahydrofuran,
Flow rate: 1.0 ml/min,
Sample concentration: 10mg/20ml

[Cis-1,4-bond amount, 1,2-vinyl bond amount]
The content of cis-1,4-bond and the content of 1,2-vinyl bond were measured by ¹ H-NMR analysis and ¹³ C-NMR analysis. The trade name “EX-270” manufactured by JEOL Ltd. was used for ¹ H-NMR analysis. Specifically, for ¹ H-NMR analysis, from the signal intensity at 5.30 to 5.50 ppm (1,4-bond) and 4.80-5.01 ppm (1,2-bond), the polymer The ratio of 1,4-bonds and 1,2-bonds therein was calculated. Furthermore, for ¹³ C-NMR analysis, from the signal intensities at 27.5 ppm (cis-1,4-bond) and 32.8 ppm (trans-1,4-bond), cis-1,4 in the polymer was obtained. The ratio of -bond and trans-1,4-bond was calculated. The ratio of these calculated values was calculated to be the cis-1,4-bond amount (mass %) and the 1,2-vinyl bond amount (mass %).

<Production Example 1 (Synthesis of modified conjugated diene polymer)>
In order to obtain a modified conjugated diene polymer (hereinafter, also referred to as “modified polymer”), the polymer solution of the conjugated diene polymer of Synthesis Example 1 was subjected to the following treatment. A toluene solution containing 1.71 mmol of 3-glycidoxypropyltrimethoxysilane was added to the polymer solution kept at a temperature of 30° C. and reacted for 30 minutes to obtain a reaction solution. Then, a toluene solution containing 1.71 mmol of 3-aminopropyltriethoxysilane was added to the reaction solution and stirred for 30 minutes. Subsequently, a toluene solution containing 1.28 mmol of tetraisopropyl titanate was added to this reaction solution, and the mixture was stirred for 30 minutes. Then, in order to stop the polymerization reaction, a methanol solution containing 1.5 g of 2,4-di-tert-butyl-p-cresol was added, and this solution was used as a modified polymer solution. The yield was 2.5 kg. Subsequently, 20 L of an aqueous solution whose pH was adjusted to 10 with sodium hydroxide was added to this modified polymer solution, and a condensation reaction was performed at 110° C. for 2 hours together with desolvation. Then, it dried with the 110 degreeC roll, and the obtained dried material was made into the modified polymer.

With respect to the modified polymer, various physical property values were measured by the following measuring methods (however, the molecular weight distribution (Mw/Mn) was measured under the same conditions as those of the above polymer) and Mooney viscosity (ML). ₁₊₄ , 125° C.) is 46, the molecular weight distribution (Mw/Mn) is 2.4, the cold flow value is 0.3 mg/min, the stability over time is 2, and the glass transition temperature is −106. It was ℃.

[Moonie viscosity (ML ₁₊₄ , 125°C)]
According to JIS K 6300, measurement was performed using an L rotor under conditions of preheating 1 minute, rotor operating time 4 minutes, and temperature 125°C.

[Cold flow value]
It was measured by extruding the polymer through a 1/4 inch orifice at a pressure of 3.5 lb/in ² and a temperature of 50°C. In order to make a steady state, after leaving for 10 minutes, the extrusion speed was measured, and the measured value was displayed in milligrams per minute (mg/min).

[Stability over time]
The Mooney viscosity (ML ₁₊₄ , 125° C.) after storage in a constant temperature bath at 90° C. for 2 days was measured and calculated by the following formula. The smaller the value, the better the stability over time.
Formula: [Moonie viscosity (ML ₁₊₄ , 125° C.) after being stored in a constant temperature bath of 90° C. for 2 days]−[Moonie viscosity measured immediately after synthesis (ML ₁₊₄ , 125° C.)]

[Glass-transition temperature]
The glass transition temperature is measured according to JIS K 7121 by using a differential scanning calorimeter (Q200) manufactured by TA Instruments Japan, Inc. while increasing the temperature at a heating rate of 10° C./min. It was determined as the glass transition start temperature.

Hereinafter, various chemicals used in Examples and Comparative Examples will be collectively described.
Natural rubber: RSS#3
Butadiene rubber: BR1220 manufactured by Nippon Zeon Co., Ltd. (cis content: 96% by mass)
Modified conjugated diene-based polymer: Modified conjugated diene-based polymer carbon black synthesized in Production Example 1: Diablack I (ASTM No. N220, N ₂ SA: 114 m ² /g, DBP: 114 ml) manufactured by Mitsubishi Chemical Corporation. /100g)
Silica: Ultrasil VN3 manufactured by Evonik Degussa (N ₂ SA: 175 m ² /g, average primary particle diameter: 15 nm)
Silane coupling agent: Si75 (bis(3-triethoxysilylpropyl)disulfide) manufactured by Evonik Degussa
Oil: Process X-140 (aroma oil) manufactured by Japan Energy Co., Ltd.
Stearic acid: stearic acid "Tsubaki" manufactured by NOF CORPORATION
Zinc oxide: Zinc flower No. 1 anti-aging agent manufactured by Mitsui Mining & Smelting Co., Ltd.: Antigen 6C (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine) manufactured by Sumitomo Chemical Co., Ltd.
Wax: Sunnock N manufactured by Ouchi Shinko Chemical Industry Co., Ltd.
Sulfur: Powder sulfur vulcanization accelerator manufactured by Karuizawa Sulfur Co., Ltd. 1: Noxceller CZ (N-cyclohexyl-2-benzothiazolyl sulfenamide) manufactured by Ouchi Shinko Chemical Co., Ltd.
Vulcanization accelerator 2: Nocceller D (N,N'-diphenylguanidine) manufactured by Ouchi Shinko Chemical Co., Ltd.

(Examples 1 to 6 and Comparative Examples 1 to 9)
According to the formulation contents shown in Tables 1 and 2, using a 1.7L Banbury mixer manufactured by Kobe Steel, Ltd., materials other than sulfur and the vulcanization accelerator (of the formulation amount shown in step 1 in Tables 1 and 2) were used. Chemicals) were kneaded for 5 minutes under the condition of about 150° C. to obtain a kneaded product (at this time, depending on the specifications, oil was divided into two and kneaded). Next, sulfur and a vulcanization accelerator were added to the obtained kneaded mixture in the compounding content shown in Step 2 of Tables 1 and 2, and kneaded for 3 minutes under the condition of about 80° C. using an open roll, An unvulcanized rubber composition was obtained. The unvulcanized rubber composition obtained is molded into a tread shape, and is bonded together with other tire members on a tire molding machine to form an unvulcanized tire, which is then vulcanized at 170° C. for 15 minutes to obtain a test tire. (Size: 195/65R15, tire for passenger car) was manufactured.

The following evaluations were performed on the obtained test tires. The results are shown in Tables 1 and 2. The reference comparative examples in Tables 1 and 2 are referred to as Comparative Example 1 and Comparative Example 5, respectively.

[Low fuel consumption performance]
Using a rolling resistance tester, the rolling resistance when the test tire was run at a rim (15×6JJ), an internal pressure (230 kPa), a load (3.43 kN), and a speed (80 km/h) was measured. The value is shown as an index when the comparative example is 100 (rolling resistance index). The larger the index, the better the rolling resistance (fuel economy performance).

[Performance on ice and snow]
The test tire was mounted on a domestic FR car of 2000 cc, and the actual vehicle was run on ice and snow under the following conditions to evaluate the performance on ice and snow. As the performance evaluation on ice and snow, specifically, the above-mentioned vehicle is used to travel on ice or snow, and the lock brake is depressed at a speed of 30 km/h to stop the brake (stop distance on ice, stop on snow) The stop distance) was measured and expressed as an index by the following formula. The larger the index, the better the performance on ice and snow (grip performance on ice and snow). If the index value exceeds 100, it can be said that the performance on ice and snow is improved.
(Brake performance [performance on ice and snow] index)=(braking stop distance of reference comparative example)/(braking stop distance of each composition)×100
(On ice) (on snow)
Test place: Hokkaido Nayoro test course Hokkaido Nayoro test course Temperature: -2 to -6°C -3 to -10°C

[Steering stability]
Test tires were attached to all wheels of a vehicle (domestic FF2000cc), the vehicle was run on a test course, and the steering stability was evaluated by sensory evaluation of the driver. At that time, relative evaluation was performed with 10 points as the perfect score and the steering stability of the reference comparative example as 6 points. The larger the value, the better the steering stability.

From Table 1, it is clear that in the summer tire of the example containing a predetermined amount of a rubber component containing a natural rubber and a specific modified conjugated diene-based polymer, and silica, fuel economy performance and steering stability can be compatible at a high level. Became.

From Table 2, it is clear that the studless tires of Examples containing a predetermined amount of silica and a rubber component containing a natural rubber and a specific modified conjugated diene-based polymer can achieve both high fuel consumption performance and performance on snow and ice at a high level. Became.

Claims (18)

A summer tire having a base tread produced using a rubber composition,
The rubber composition contains a rubber component containing a natural rubber and a modified conjugated diene polymer, and silica.
The modified conjugated diene-based polymer has a cis-1,4-bond content of 94.0% by mass or more, and a conjugated diene-based polymer having an active end is used, and the active end of the conjugated diene-based polymer is A modification step (A) of carrying out a modification reaction for introducing an alkoxysilane compound having two or more reactive groups containing an alkoxysilyl group, and to group 4, 12, 13, 13, 14 and 15 of the periodic table. A condensation step (B) in which the residue of the alkoxysilane compound introduced into the active terminal is subjected to a condensation reaction in the presence of a condensation catalyst containing at least one element selected from the group consisting of the elements contained. As the conjugated diene polymer, a conjugated diene polymer obtained by a production method using a conjugated diene polymer polymerized in the presence of a catalyst composition containing a mixture of the following components (a) to (c) as a main component,
The nitrogen adsorption specific surface area of the silica is 40 to 200 m ² /g,
The total content of the natural rubber and the modified conjugated diene-based polymer is 20 to 100% by mass in 100% by mass of the rubber component,
The content of natural rubber is 50 to 85% by mass in 100% by mass of the rubber component,
The content of the modified conjugated diene-based polymer is 15 to 50 % by mass in 100% by mass of the rubber component,
The content of the said silica is 5-45 mass parts with respect to 100 mass parts of said rubber components, The summer tire characterized by the above-mentioned.
Component (a): A lanthanoid-containing compound containing at least one element selected from the group consisting of lanthanoids, or a reaction product obtained by reacting the lanthanoid-containing compound with a Lewis base (b) component: alumino Xanthane and an organoaluminum compound represented by the general formula (1); AlR ¹ R ² R ³ (wherein, in the general formula (1), R ¹ and R ² are the same or different and have 1 to 10 carbon atoms). of .R ³ representing a hydrocarbon group or a hydrogen atom are the same or different and R ¹ and R ^2, at least one compound selected from the group consisting of representing.) the hydrocarbon group having 1 to 10 carbon atoms Component (c): an iodine-containing compound containing at least one iodine atom in its molecular structure 2. The summer according to claim 1, wherein the ratio (Mw/Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the conjugated diene polymer measured by gel permeation chromatography is 3.5 or less. tire. The summer tire according to claim 1 or 2, wherein the conjugated diene polymer has a 1,2-vinyl bond content of 0.5% by mass or less. The summer tire according to claim 1, wherein the condensation catalyst contains titanium (Ti). The summer tire according to claim 1, wherein the alkoxysilane compound contains at least one functional group selected from the group consisting of the following (f) to (i).
(F); Epoxy group (g); Isocyanate group (h); Carbonyl group (i); Cyano group The summer according to any one of claims 1 to 5, wherein in the modification step (A), an alkoxysilane compound having at least one functional group selected from the group consisting of the following (j) to (l) is added. tire.
(J); amino group (k); imino group (l); mercapto group The summer tire according to any one of claims 1 to 6, wherein the condensation reaction in the condensation step (B) is performed in an aqueous solution having a pH of 9 to 14 and a temperature of 85 to 180°C. The conjugated diene compound constituting the modified conjugated diene polymer is at least one conjugated diene compound selected from the group consisting of 1,3-butadiene, isoprene and 2,3-dimethyl-1,3-butadiene. The summer tire according to any one of claims 1 to 7. The method for producing a summer tire according to claim 1, further comprising a step of kneading a rubber component containing the natural rubber and a modified conjugated diene polymer and the silica. A studless tire having a base tread produced using a rubber composition,
The rubber composition contains a rubber component containing a natural rubber and a modified conjugated diene polymer, silica, and carbon black,
The modified conjugated diene-based polymer has a cis-1,4-bond content of 94.0% by mass or more, and a conjugated diene-based polymer having an active end is used, and the active end of the conjugated diene-based polymer is A modification step (A) of carrying out a modification reaction for introducing an alkoxysilane compound having two or more reactive groups containing an alkoxysilyl group, and to group 4, 12, 13, 13, 14 and 15 of the periodic table. A condensation step (B) in which the residue of the alkoxysilane compound introduced into the active terminal is subjected to a condensation reaction in the presence of a condensation catalyst containing at least one element selected from the group consisting of the elements contained. As the conjugated diene polymer, a conjugated diene polymer obtained by a production method using a conjugated diene polymer polymerized in the presence of a catalyst composition containing a mixture of the following components (a) to (c) as a main component,
The nitrogen adsorption specific surface area of the silica is 40 to 200 m ² /g,
The nitrogen adsorption specific surface area of the carbon black is 90 to 250 m ² /g,
The total content of the natural rubber and the modified conjugated diene-based polymer is 20 to 100% by mass in 100% by mass of the rubber component,
The content of the modified conjugated diene-based polymer is 10 to 90% by mass in 100% by mass of the rubber component,
Against 100 parts by mass of the rubber component, the content of the silica Ri Ah 60 to 100 parts by weight,
Wherein the rubber component 100 parts by weight, studless tires content of said carbon black and said 7 to 20 parts by der Rukoto.
Component (a): A lanthanoid-containing compound containing at least one element selected from the group consisting of lanthanoids, or a reaction product obtained by reacting the lanthanoid-containing compound with a Lewis base (b) component: alumino Xanthane and an organoaluminum compound represented by the general formula (1); AlR ¹ R ² R ³ (wherein, in the general formula (1), R ¹ and R ² are the same or different and have 1 to 10 carbon atoms). of .R ³ representing a hydrocarbon group or a hydrogen atom are the same or different and R ¹ and R ^2, at least one compound selected from the group consisting of representing.) the hydrocarbon group having 1 to 10 carbon atoms Component (c): an iodine-containing compound containing at least one iodine atom in its molecular structure The studless according to claim 10, wherein the ratio (Mw/Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the conjugated diene polymer measured by gel permeation chromatography is 3.5 or less. tire. The studless tire according to claim 10 or 11, wherein the conjugated diene polymer has a 1,2-vinyl bond content of 0.5% by mass or less. The studless tire according to claim 10, wherein the condensation catalyst contains titanium (Ti). The studless tire according to claim 10, wherein the alkoxysilane compound contains at least one functional group selected from the group consisting of the following (f) to (i).
(F); Epoxy group (g); Isocyanate group (h); Carbonyl group (i); Cyano group 15. The studless according to claim 10, wherein in the modification step (A), an alkoxysilane compound containing at least one functional group selected from the group consisting of the following (j) to (l) is added. tire.
(J); amino group (k); imino group (l); mercapto group The studless tire according to any one of claims 10 to 15, wherein the condensation reaction in the condensation step (B) is performed in an aqueous solution having a pH of 9 to 14 and a temperature of 85 to 180°C. The conjugated diene compound constituting the modified conjugated diene polymer is at least one conjugated diene compound selected from the group consisting of 1,3-butadiene, isoprene and 2,3-dimethyl-1,3-butadiene. The studless tire according to claim 10. The method for producing a studless tire according to any one of claims 10 to 17, comprising a step of kneading a rubber component containing the natural rubber and a modified conjugated diene polymer with the silica.