JP2003155302A - Modified diene polymer, rubber composition and pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a modified diene polymer for providing a rubber composition compounded with silica and/or carbon black, which increases interaction between silica and carbon black, improves fracture characteristics, abrasion resistance and low heat build-up and can exhibit excellent workability and the rubber composition. SOLUTION: This modified diene-based polymer contains (a) a silicon- containing group and (b) at least one kind of a group selected from the group of an acid anhydride group, a carboxy group and a carbonyl group in the molecule. This rubber composition comprises the modified diene polymer. Preferably the rubber composition comprises (A) a rubber component containing at least 30 wt.% of the modified diene polymer and (B) 10-100 parts wt. based on 100 parts wt. of the rubber component of silica and/or carbon black.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a modified diene polymer, a rubber composition and a pneumatic tire. More specifically, the present invention enhances the interaction with silica and carbon black when used in both a silica-based compounding rubber composition and a carbon black-based compounding rubber composition, and provides fracture properties, abrasion resistance and low heat build-up. The present invention relates to a modified diene polymer capable of simultaneously improving and exhibiting good workability, a rubber composition containing the modified diene polymer, and a pneumatic tire using the composition.

[0002]

2. Description of the Related Art In recent years, the demand for low fuel consumption of automobiles has become more severe in response to the worldwide movement of carbon dioxide emission regulations accompanying the social demand for energy saving and the growing concern about environmental problems. It's starting. In order to meet such demands, it has been required to reduce rolling resistance in tire performance. As a method of reducing the rolling resistance of a tire, although a method by optimizing a tire structure has been studied, the most general method is to use a material having a lower heat generation property as a rubber composition.

In order to obtain such a rubber composition having a low exothermicity, many technical developments have been made so far to enhance the dispersibility of the filler used in the rubber composition. Among them, in particular, a method of modifying a polymerization active terminal of a diene polymer obtained by anionic polymerization using an organolithium compound with a functional group having an interaction with a filler is becoming most popular.

The most typical of these methods is to use carbon black as a filler and modify the polymerization active terminal with a tin compound (Japanese Patent Publication No. 5-87630).
JP-A-62-20734, similarly using carbon black and introducing an amino group at the polymerization active terminal.
No. 2) is known. On the other hand, in recent years, with increasing interest in safety of automobiles, not only fuel efficiency performance but also performance on wet road surface (hereinafter referred to as wet performance), particularly braking performance, has been increased. Therefore, the performance requirement for the rubber composition of the tire tread is:
What is needed is not only a reduction in rolling resistance, but also a high degree of compatibility between wet performance and low fuel consumption performance.

As a method of obtaining a rubber composition that simultaneously provides such a good fuel economy and a good wet performance to a tire, carbon black, which has been generally used until now, has been used as a reinforcing filler. The method using silica has already been carried out. However, when silica is used as a reinforcing filler, compared to carbon black,
It has also been revealed that the breaking strength and wear resistance of the rubber composition are unavoidably deteriorated. Further, the dispersibility of silica is poor, and the workability when kneading is also
It has become a big problem in actually manufacturing a tire.

Therefore, in order to obtain a rubber composition having good heat generation with good productivity, not only carbon black or silica is used alone as a reinforcing filler, but also silica and carbon black are used in combination. There is a need for a terminally modified polymer that has a wide range of interactions with a wide variety of fillers and that can provide good dispersibility of the filler and abrasion resistance of the rubber composition. However, until now, the development of a terminal-modified polymer has been carried out for a single filler, so that regardless of the type of the filler, a terminal-modified polymer having sufficient interaction with various fillers can be used. The current situation is that it is extremely limited.

For example, although the tin compound described above has a large dispersing effect on carbon black, it has almost no dispersing effect on silica and exhibits no reinforcing effect at all. Further, Japanese Patent Application Laid-Open No. 9-151275 reports a dispersion effect of aminosilane on silica, but the effect is not always sufficient.

On the other hand, a method of using an alkoxysilane having an effect of dispersing silica and an effect of improving the reinforcing property has been disclosed (JP-A-1-188501 and JP-A-8-53).
No. 513 and JP-A-8-53576), it is clear that the use of carbon black as a reinforcing filler has no effect because the alkoxysilyl group has no interaction with carbon black. . The same applies to other modified polymers for silica, and methods using, for example, aminoacrylamide have been disclosed (JP-A-9-71687, JP-A-9-208633). However, although this method has some effect on improving dispersion of silica, almost no effect on improving dispersion of carbon black is observed, and a rubber composition or carbon black compounding system of a combination of carbon black and silica is used. The rubber composition of (1) has a problem such as increased hysteresis loss.

Further, a modified polymer in which an alkoxysilane having a dialkylamino group is introduced into the active terminal of a polymer obtained by anionic polymerization using alkyllithium or lithium amide as a polymerization initiator is disclosed (Japanese Patent Publication No. 6-53763, Japanese Patent Publication 6-57767). However, when this modified polymer is used, good workability is obtained, and although a reinforcing effect for silica blending and a certain dispersing effect for both silica and carbon black are obtained, the amino group has little effect on carbon black and is substituted with a dialkyl group. Since it is a mold, a sufficient effect cannot be obtained, especially for a blending system containing a large amount of carbon black, as compared with the case where a modified polymer obtained by using a tin-based modifier is used.

[0010]

Under such circumstances, the present invention enhances the interaction with silica and carbon black when used in both a silica-based compounding agent and a carbon black-based compounding rubber composition. , A modified diene-based polymer capable of simultaneously improving the breaking property, abrasion resistance and low heat build-up and exhibiting good workability, a rubber composition containing the modified diene-based polymer, and the rubber composition The purpose of the present invention is to provide a conventional pneumatic tire.

[0011]

Means for Solving the Problems As a result of intensive studies for achieving the above-mentioned object, the inventors of the present invention have found that a specific and favorable interaction with both silica and carbon black is present in the molecule. A modified diene-based polymer having (a) a silicon-containing group and (b) at least one group selected from an acid anhydride group, a carboxyl group and a carbonyl group having I found it. The present invention is
It was completed based on this knowledge.

That is, the present invention provides (1) in the molecule:
(2) A modified diene-based polymer containing (a) a silicon-containing group and (b) at least one group selected from an acid anhydride group, a carboxyl group and a carbonyl group.
The above-mentioned (1) in which a silicon compound residue having (a) a silicon-containing group and (b) at least one group selected from an acid anhydride group, a carboxyl group and a carbonyl group is introduced at the terminal of the diene polymer. ) Modified diene polymer, (3)
The modified diene polymer according to the above (2), which is obtained by reacting the end of the diene polymer having an active terminal with a hydrocarbyloxysilane compound having an acid anhydride group in the molecule.
(4) The hydrocarbyloxysilane compound having an acid anhydride group in the molecule has the general formula (I)

[0013]

[Chemical 2]

(In the formula, A ¹ is a divalent hydrocarbon group having 1 to 20 carbon atoms, and R ^{1 to} R ³ are independently 1 to 1 carbon atoms.
2, a monovalent hydrocarbon group, R ⁴ is a hydrogen atom or a carbon number of 1 to
12 monovalent hydrocarbon groups, R ³ and R ⁴ may combine with each other to form a ring structure, n is 2 or 3, and each R ¹ O is the same or different. May be. (3) A modified diene polymer having a structure represented by (4), (5) A rubber composition comprising the modified diene polymer of (1) to (4) above, (6). (A)
At least 3 modified diene-based polymers of the above (1) to (4)
A rubber component containing 0% by weight and 100 parts by weight thereof,
(B) Silica and / or carbon black 10 to 100
A pneumatic tire comprising the rubber composition according to the above (5) containing parts by weight and (7) the rubber composition according to the above (5) and (6) as a tread rubber. is there.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION First, the modified diene polymer of the present invention will be described. The modified diene polymer of the present invention,
The molecule contains at least one group selected from the group consisting of (a) a silicon-containing group and (b) an acid anhydride group, a carboxyl group and a carbonyl group. Examples of such groups include diene-based polymers. Examples thereof include those in which a silicon compound residue having (a) a silicon-containing group and (b) at least one group selected from an acid anhydride group, a carboxyl group and a carbonyl group is introduced. This modified diene polymer can be obtained, for example, by reacting the terminal of a diene polymer having an active terminal with a hydrocarbyloxysilane compound having an acid anhydride group in the molecule.

The method for producing the diene polymer having active terminals is not particularly limited, and any of solution polymerization method, gas phase polymerization method and bulk polymerization method can be used.
The solution polymerization method is particularly preferable. Further, the polymerization system may be either a batch system or a continuous system. In the solution polymerization method, for example, an organic alkali metal compound is used as a polymerization initiator, and the conjugated diene compound alone or the conjugated diene compound and the aromatic vinyl compound are subjected to anionic polymerization to produce the desired polymer.

Examples of the conjugated diene compound include 1,3-butadiene; isoprene; 1,3-pentadiene; 2,3-dimethylbutadiene; 2-phenyl-1,
3-butadiene; 1,3-hexadiene and the like can be mentioned. These may be used alone or in combination of two or more, and of these, 1,3-butadiene is particularly preferable.

Examples of the aromatic vinyl compound used for copolymerization with these conjugated diene compounds include styrene; α-methylstyrene; 1-vinylnaphthalene;
3-vinyltoluene; ethylvinylbenzene; divinylbenzene; 4-cyclohexylstyrene; 2,4,6-
Examples include trimethylstyrene. These may be used alone or in combination of two or more, and among these, styrene is particularly preferable.

Further, when the conjugated diene compound and the aromatic vinyl compound are used as the monomers for the copolymerization, the use of 1,3-butadiene and styrene, respectively, is practical because the monomers are easily available. And excellent anionic polymerization characteristics in terms of living property and the like are particularly preferable. When the solution polymerization method is used, the monomer concentration in the solvent is preferably 5 to 50% by weight, more preferably 10 to 30% by weight. When the conjugated diene compound and the aromatic vinyl compound are copolymerized, the content of the aromatic vinyl compound in the charged monomer mixture is preferably 3 to 50% by weight, more preferably 5 to 45% by weight. Is preferred.

Preferred examples of the organic alkali metal compound as the polymerization initiator include organic lithium compounds. The organolithium compound is not particularly limited, but hydrocarbyllithium and lithium amide compounds are preferably used, and when the former hydrocarbyllithium is used, it has a hydrogen atom at one end and the other end has a polymerization activity. A terminal conjugated diene polymer is obtained. When the latter lithium amide compound is used, a conjugated diene polymer having a nitrogen-containing group at one end and a polymerization active end at the other end can be obtained.

The above-mentioned hydrocarbyl lithium is preferably one having a hydrocarbyl group having 2 to 20 carbon atoms, such as ethyl lithium, n-propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, tert-octyl lithium, Examples thereof include n-decyl lithium, phenyl lithium, 2-naphthyl lithium, 2-butyl-phenyl lithium, 4-phenyl-butyl lithium, cyclohexyl lithium, cyclopentyl lithium, and a reaction product of diisopropenylbenzene and butyl lithium. , Of these,
N-butyllithium is preferred.

On the other hand, as the lithium amide compound, for example, lithium hexamethylene imide, lithium pyrrolidide, lithium piperidide, lithium heptamethylene imide, lithium dodecamethylene imide, lithium dimethyl amide, lithium diethyl amide, lithium dibutyl amide, lithium dipropyl Amide, lithium diheptylamide, lithium dihexylamide, lithium dioctylamide, lithium di-2-ethylhexylamide, lithium didecylamide, lithium N-methylpiperazide, lithium ethylpropylamide, lithium ethylbutylamide, lithium methylbutylamide, lithium ethyl Examples thereof include benzylamide and lithium methylphenethylamide. Among these, cyclic lithium amides such as lithium hexamethylene imide, lithium pyrrolidide, lithium piperidide, lithium heptamethylene imide, and lithium dodecamethylene imide are preferable from the viewpoint of interaction effect on carbon black and polymerization initiation ability. Lithium hexamethylene imide and lithium pyrrolidide are particularly preferred.

These lithium amide compounds are generally prepared in advance from a secondary amine and a lithium compound in many cases, but they can be prepared in a polymerization system. The amount of the polymerization initiator used is preferably selected in the range of 0.2 to 20 mmol per 100 g of the monomer. The method for producing the conjugated diene polymer by anionic polymerization using the organolithium compound as a polymerization initiator is not particularly limited, and a conventionally known method can be used.

Specifically, in a reaction-inert organic solvent, for example, a hydrocarbon solvent such as an aliphatic, alicyclic, or aromatic hydrocarbon compound, a conjugated diene compound or a conjugated diene compound and an aromatic vinyl compound are used. Using the lithium compound as a polymerization initiator, if desired, is subjected to anionic polymerization in the presence of a randomizer to be used, whereby a target conjugated diene polymer is obtained.

The hydrocarbon solvent has 3 to 10 carbon atoms.
8 are preferred, for example, propane, n-butane, isobutane, n-pentane, isopentane, n-hexane, cyclohexane, propene, 1-butene, isobutene, trans-2-butene, cis-2-butene, 1-pentene. , 2-pentene, 1-hexene, 2-hexene,
Examples thereof include benzene, toluene, xylene and ethylbenzene. These may be used alone or in combination of two or more.

The randomizer optionally used means control of the microstructure of the conjugated diene polymer, for example, increase of 1,2 bond of butadiene moiety in butadiene-styrene copolymer and increase of 3,4 bond in isoprene polymer. Or a compound having a function of controlling the composition distribution of monomer units in a conjugated diene compound-aromatic vinyl compound copolymer, for example, randomizing butadiene units and styrene units in a butadiene-styrene copolymer. is there. The randomizer is not particularly limited, and any compound can be appropriately selected and used from known compounds generally used as conventional randomizers. Specifically, dimethoxybenzene, tetrahydrofuran, dimethoxyethane, diethylene glycol dibutyl ether, diethylene glycol dimethyl ether, bistetrahydrofuryl propane,
Triethylamine, pyridine, N-methylmorpholine,
N, N, N ', N'-tetramethylethylenediamine,
Examples thereof include ethers such as 1,2-dipiperidinoethane and tertiary amines. Further, potassium salts such as potassium-t-amylate and potassium-t-butoxide, and sodium salts such as sodium-t-amylate can also be used. These randomizers may be used alone or in combination of two or more. The amount used is preferably selected in the range of 0.01 to 1000 molar equivalents per 1 mol of the organolithium compound.

The temperature in this polymerization reaction is preferably selected in the range of -80 to 150 ° C, more preferably -20 to 100 ° C. The polymerization reaction can be carried out under a generated pressure, but it is usually desirable to operate at a pressure sufficient to keep the monomer substantially in the liquid phase. That is, the pressure will depend on the particular material being polymerized, the polymerization medium used, and the polymerization temperature, but higher pressures can be used if desired, and such pressures are inert gases with respect to the polymerization reaction and are used in the reactor. Can be obtained by a suitable method such as pressurizing. In this polymerization, it is desirable to use all raw materials involved in the polymerization, such as a polymerization initiator, a solvent, and a monomer, from which reaction inhibitors such as water, oxygen, carbon dioxide, and a protic compound have been removed.

The glass transition point (Tg) of the obtained polymer or copolymer determined by differential thermal analysis (DSC).
Is preferably −90 ° C. to −20 ° C. It is difficult to obtain a polymer having a glass transition point of less than −90 ° C., and when it exceeds -20 ° C., the viscosity becomes too high in the room temperature region, which may make the handling difficult. In the present invention, the hydrocarbyloxysilane compound having an acid anhydride group to react with the terminal of the polymer having an active terminal thus obtained is represented by the general formula (I)

[0029]

[Chemical 3]

(In the formula, A ¹ is a divalent hydrocarbon group having 1 to 20 carbon atoms, and R ^{1 to} R ³ are independently 1 to 1 carbon atoms.
2, a monovalent hydrocarbon group, R ⁴ is a hydrogen atom or a carbon number of 1 to
12 monovalent hydrocarbon groups, R ³ and R ⁴ may combine with each other to form a ring structure, n is 2 or 3, and each R ¹ O is the same or different. May be. The compound which has a structure represented by these can be used.

In the above general formula (I), the divalent hydrocarbon group having 1 to 20 carbon atoms represented by A ¹ is, for example, an alkylene group having 1 to 20 carbon atoms, an alkenylene group having 2 to 20 carbon atoms, Arylene group having 6 to 20 carbon atoms, 7 carbon atoms
Examples thereof include an aralkylene group having 20 to 20 carbon atoms, and among these, an alkylene group having 1 to 20 carbon atoms is preferable. The alkylene group may be linear, branched, or cyclic, but the linear one is particularly preferable. Examples of the linear alkylene group include methylene group, ethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, octamethylene group, decamethylene group and dodecamethylene group.

On the other hand, carbon numbers 1 to 1 represented by R ^{1 to} R ³
2 monovalent hydrocarbon groups and 1 to 12 carbon atoms of R ⁴
Examples of the monovalent hydrocarbon group include an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, and a carbon number 6
To 12 aryl groups and C7 to C12 aralkyl groups. Here, the alkyl group and alkenyl group may be linear, branched, or cyclic, and examples thereof include a methyl group, an ethyl group, and an n group.
-Propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, decyl group, dodecyl group, cyclopentyl group, cyclohexyl group, vinyl group,
Examples thereof include a propenyl group, an allyl group, a hexenyl group, an octenyl group, a cyclopentenyl group, and a cyclohexenyl group.

Further, the aryl group may have a substituent such as a lower alkyl group on the aromatic ring, and examples thereof include a phenyl group, a tolyl group, a xylyl group and a naphthyl group. Further, the aralkyl group may have a substituent such as a lower alkyl group on the aromatic ring, and examples thereof include a benzyl group, a phenethyl group and a naphthylmethyl group.

R ^{1 to} R ³ may be the same or different from each other, and R ³ and R ⁴ may be bonded to each other to form a ring structure. That is, the acid anhydride group may be either a non-cyclic acid anhydride group or a cyclic acid anhydride group. Further, n is 2 or 3, and the number of hydrocarbyloxy groups is 2 or 3. Each of the plurality of R ¹ O may be the same or different.

Examples of the hydrocarbyloxysilane compound represented by the general formula (I) include those having an acyclic acid anhydride group, such as 3-triethoxysilylpropyl acetic anhydride, 3-triphenoxysilylpropyl acetic anhydride, Examples thereof include 3-trimethoxysilylpropyl acetic anhydride, 3-diethoxy (methyl) silylpropyl acetic anhydride, 3-dimethoxy (methyl) silylpropyl acetic anhydride, and the like having a cyclic acid anhydride group, for example, 3-triethoxy. Silylpropyl succinic anhydride, 3-triphenoxysilylpropyl succinic anhydride, 3-trimethoxysilylpropyl succinic anhydride, 3-diethoxy (methyl) silylpropyl succinic anhydride, 3-dimethoxy (methyl) silylpropyl succinic anhydride, etc. Is mentioned.
Among these, those having a cyclic acid anhydride group are preferable, and among them, 3-triethoxysilylpropylsuccinic anhydride is preferable from the viewpoints of the filler dispersing effect and the reinforcing effect.

In the present invention, the amount of the hydrocarbyloxysilane compound represented by the above general formula (I) (hereinafter sometimes referred to as a terminal modifier) is used in the production of the diene polymer. The polymerization initiator is usually selected in the range of 0.1 to 3.0 mol, preferably 0.3 to 1.5 mol, based on 1 mol of the organic alkali metal compound. 0.1
If the amount is less than the molar amount, the hydrocarbyloxy group is consumed in the coupling reaction, which is not preferable. Further, when the amount exceeds 3.0 moles, the excess terminal modifier is wasted, and impurities contained in the terminal modifier deactivate the polymerization active terminals, which substantially reduces the modification efficiency, which is preferable. Absent.

As the reaction temperature at this time, the polymerization temperature of the conjugated diene polymer can be used as it is. Specifically, a preferable range is 30 to 100 ° C. If it is lower than 30 ° C., the viscosity of the polymer tends to increase too much, and if it exceeds 100 ° C., the polymerization active terminal tends to be deactivated, which is not preferable. The timing and method of adding the terminal modifying agent to the polymerization active terminal of the conjugated diene polymer are not particularly limited, but generally when such a terminal modifying agent is used, it is often carried out after completion of the polymerization.

When this terminal modifier is reacted with the active end of the conjugated diene polymer, both the nucleophilic substitution reaction of the active end and the hydrocarbyloxysilane group and the nucleophilic substitution reaction of the acid anhydride group are carried out. Occurs, and the modified diene polymer of the present invention is obtained. For the case where a hydrocarbyloxysilane compound having a non-cyclic acid anhydride group and a cyclic acid anhydride group as the terminal modifier, specifically a hydrocarbyloxysilane compound having a succinic anhydride residue, is used, the reaction formulas are as follows. become that way.

(1) When a hydrocarbyloxysilane compound having an acyclic acid anhydride group is used,

[0040]

[Chemical 4]

(In the formula, A ¹ , R ^{1 to} R ⁴ and n are the same as above, but R ³ and R ⁴ are not bonded to each other and do not form a ring structure.) Reaction formula (II- a) shows a nucleophilic substitution reaction between an active end of a polymer and a hydrocarbyloxysilane group, and a reaction formula (II
-B) shows a nucleophilic substitution reaction between the active end of the polymer and the acid anhydride group. In the former reaction, a silicon compound residue having a hydrocarbyloxy group and an acid anhydride group is introduced at the end of the diene polymer, and in the latter reaction, a hydrocarbyloxy group and a carbonyl group are introduced at the end of the diene polymer. And a silicon compound residue having a group is introduced. Of course, in a single molecule of the terminal modifier, both of the above reactions may occur.

(2) When a hydrocarbyloxysilane compound having a cyclic acid anhydride group is used,

[0043]

[Chemical 5]

(In the formula, A ¹ , R ¹ , R ² and n are the same as above.) This reaction uses a hydrocarbyloxysilane compound having a succinic anhydride residue as a cyclic acid anhydride group. The reaction formula (III-a) shows a nucleophilic substitution reaction between the active end of the polymer and the hydrocarbyloxysilane group, and the reaction formula (III-b) shows the reaction between the active end of the polymer and the succinic anhydride residue. Shows a nucleophilic substitution reaction with a group. In the former reaction, a silicon compound residue having a hydrocarbyloxy group and a succinic anhydride residue is introduced at the end of the diene polymer, and in the latter reaction, a hydrocarbyloxy group and a hydrocarbyloxy group are introduced at the end of the diene polymer. , A silicon compound residue having a carbonyl group and a carboxyl group is introduced. Of course, in a single molecule of the terminal modifier, both of the above reactions may occur.

Thus, at least one of (a) a silicon-containing group (hydrocarbyloxysilane group) and (b) an acid anhydride group, a carboxyl group and a carbonyl group is attached to the end of the diene polymer. A modified diene-based polymer of the present invention having a silicon compound residue having a group introduced therein is obtained. When this modified diene polymer is blended with silica, for example, reaction formula (IV)

[0046]

[Chemical 6]

(Wherein A ¹ , R ^{1 to} R ⁴ and n are the same as above), the silanol group, which is the surface functional group of silica, and the hydrocarbyloxy group undergo a condensation reaction. Causes a chemical bond. Therefore, at this time, it is important that n is 2 or 3. The reason is that when n is 1, the hydrocarbyloxy group is
This is because it is considered that the diene polymer is consumed in the nucleophilic substitution reaction to the terminal, does not exist for the condensation reaction with the silanol group on the silica surface, and the condensation reaction with the silanol group does not occur.

Further, the acid anhydride group, the carbonyl group and the carboxyl group form a hydrogen bond with the silanol group which is a surface functional group of silica. Furthermore, an acid anhydride group, a carboxyl group and a carbonyl group show a good interaction with carbon black, and particularly when a hydrocarbyloxysilane compound having a cyclic acid anhydride group is used as a terminal modifier, Both groups and carboxyl groups are introduced at the polymer end and thus exhibit a strong interaction with carbon black.

As described above, the modified diene polymer of the present invention enhances the interaction with silica and carbon black and has a destructive property when used in both a rubber composition containing silica and carbon black. It is possible to improve wear resistance and low heat generation property at the same time and to exhibit good workability. The modified chain end modified group in the modified diene polymer of the present invention is analyzed by a method using high performance liquid chromatography (HPLC) for the terminal amounts of the acid anhydride group, the carboxyl group and the carbonyl group, and hydrocarbyloxysilane. Nuclear magnetic resonance spectroscopy (N
This can be done by measuring MR).

The modified diene polymer has a glass transition point (Tg) measured by DSC of usually -90 ° C to 0.
℃, Mooney viscosity (ML _{1 + 4} , 100 ℃)
However, preferably 10 to 150, more preferably 15 to 7
It is 0. When the Mooney viscosity is less than 10, rubber properties such as breaking properties are not sufficiently obtained, and when it exceeds 150, workability is poor and it is difficult to knead with a compounding agent.

The rubber composition of the present invention contains the modified diene-based polymer obtained by the above-mentioned method, and usually (A) a rubber component containing at least 30% by weight of the modified diene-based polymer and its 100 parts. A composition containing 10 to 100 parts by weight of (B) silica and / or carbon black is used per part by weight. In the rubber composition of the present invention,
It is preferable that at least 30% by weight of the modified diene polymer is contained as the rubber component of the component (A). If this amount is less than 30% by weight, it is difficult to obtain a rubber composition having desired physical properties, and the object of the present invention may not be achieved.
The more preferable content of the modified diene polymer in the rubber component is 35% by weight or more, and 40 to 100% by weight is particularly preferable.

The modified diene polymer may be used alone or in combination of two or more kinds. Examples of the rubber component used in combination with the modified diene polymer include natural rubber and diene synthetic rubber. Examples of the diene synthetic rubber include styrene-butadiene copolymer (SBR) and polybutadiene (BR). , Polyisoprene (IR), butyl rubber (IIR), ethylene-propylene copolymers and mixtures thereof. Also,
A part thereof may have a branched structure by using a polyfunctional modifier, for example, a modifier such as tin tetrachloride.

In the rubber composition of the present invention, silica and / or carbon black is preferably used as the reinforcing filler for the component (B). The silica is not particularly limited and may be arbitrarily selected from those conventionally used as a reinforcing filler for rubber.
Examples of the silica include wet silica (hydrous silicic acid), dry silica (anhydrous silicic acid), calcium silicate,
Examples thereof include aluminum silicate, and among them, wet silica is most preferable because it has the most remarkable effect of improving the fracture characteristics and the effect of achieving both wet grip properties. On the other hand, the carbon black is not particularly limited, and any one can be selected and used from among those conventionally used as a reinforcing filler for rubber. Examples of the carbon black include FEF, SRF, HAF, ISAF, SAF
Etc. The iodine adsorption amount (IA) is preferably 6
It is carbon black of 0 mg / g or more and having a dibutyl phthalate oil absorption (DBP) of 80 ml / 100 g or more. By using this carbon black, the effect of improving various physical properties becomes great, but HAF, ISAF, and SAF, which are excellent in wear resistance, are particularly preferable.

The blending amount of the reinforcing filler of the component (B) is 100 parts by weight of the rubber component of the component (A).
It is preferably 10 to 100 parts by weight. When the compounding amount of the reinforcing filler of the component (B) is less than 10 parts by weight with respect to the rubber component of the component (A), it is difficult to sufficiently exert the effect of improving the reinforcing property and other physical properties, and 100 parts by weight. If it exceeds the part, it becomes a cause of deterioration of workability. In consideration of the reinforcing property, other physical properties and processability, the blending amount of the component (B) is particularly preferably in the range of 20 to 60 parts by weight.

In the rubber composition of the present invention, when silica is used as the reinforcing filler of the component (B), a silane coupling agent can be added for the purpose of further improving its reinforcing property. Examples of the silane coupling agent include bis (3-triethoxysilylpropyl)
Tetrasulfide, bis (3-triethoxysilylpropyl) trisulfide, bis (3-triethoxysilylpropyl) disulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, Bis (2-trimethoxysilylethyl) tetrasulfide, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, 3-trimethoxysilylpropyl -N, N-dimethylthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-
N, N-dimethylthiocarbamoyl tetrasulfide,
3-trimethoxysilylpropyl benzothiazolyl tetrasulfide, 3-triethoxysilylpropyl benzothiazolyl tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, bis (3- Diethoxymethylsilylpropyl) tetrasulfide, 3-mercaptopropyldimethoxymethylsilane, dimethoxymethylsilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, dimethoxymethylsilylpropylbenzothiazolyltetrasulfide, and the like. Among them, bis (3-triethoxysilylpropyl) tetrasulfide and 3-trimethoxysilylpropyl benzothiazolyl teto from the viewpoint of reinforcing effect. Sulfide is preferred. These silane coupling agents may be used alone or in combination of two or more.

In the rubber composition of the present invention, since a modified diene polymer having a functional group having a high affinity for silica introduced at the molecular end is used as a rubber component, a silane coupling agent is blended. The amount can be smaller than usual. The preferable blending amount of the silane coupling agent varies depending on the kind of the silane coupling agent and the like, but is preferably selected in the range of 1 to 20% by weight with respect to the silica. If this amount is less than 1% by weight, the effect as a coupling agent is not sufficiently exhibited, and if it exceeds 20% by weight, gelation of the rubber component may be caused. From the viewpoint of the effect as a coupling agent and the prevention of gelation, the preferable amount of the silane coupling agent is in the range of 5 to 15% by weight.

If desired, the rubber composition of the present invention contains various chemicals usually used in the rubber industry, such as a vulcanizing agent, a vulcanization accelerator, a process oil, and an aging, as long as the object of the present invention is not impaired. Inhibitors, anti-scorch agents, zinc white, stearic acid and the like may be included. Examples of the vulcanizing agent include sulfur and the like.
The sulfur content is preferably 0.1 to 10.0 parts by weight, more preferably 1.0 to 5.0 parts by weight, based on parts by weight. If the amount is less than 0.1 part by weight, the breaking strength, abrasion resistance and low heat buildup of the vulcanized rubber may be deteriorated, and if it exceeds 10.0 parts by weight, rubber elasticity may be lost.

The vulcanization accelerator that can be used in the present invention is not particularly limited, but for example, M (2-mercaptobenzothiazole), DM (dibenzothiazyl disulfide), CZ (N-cyclohexyl-2-). Benzothiazyl sulfenamide) and other thiazoles, or DP
Examples of the vulcanization accelerator include a guadinine-based vulcanization accelerator such as G (diphenylguanidine).
0.1 to 5.0 parts by weight is preferable with respect to 00 parts by weight,
It is more preferably 0.2 to 3.0 parts by weight.

The process oil usable in the rubber composition of the present invention includes, for example, paraffin type, naphthene type,
Aromatic type etc. can be mentioned. An aromatic type is used for applications where importance is attached to tensile strength and wear resistance, and a naphthene type or paraffin type is used for applications where importance is attached to hysteresis loss and low temperature characteristics. The amount used is rubber component 1
0 to 100 parts by weight, preferably 1 to 100 parts by weight
If it exceeds 100 parts by weight, the vulcanized rubber tends to deteriorate in tensile strength and low heat buildup.

The rubber composition of the present invention is obtained by kneading with a kneading machine such as a roll or an internal mixer. After molding, the rubber composition is vulcanized to obtain a tire tread, an undertread, a carcass and a side. It can be used not only for tires such as walls and beads, but also for applications such as anti-vibration rubber, belts, hoses and other industrial products, and is particularly preferably used as rubber for tire treads.

The pneumatic tire of the present invention is produced by the usual method using the rubber composition of the present invention. That is, if necessary, the rubber composition of the present invention containing various chemicals as described above is extruded into a member for tread at an unvulcanized stage, and is pasted and molded by a usual method on a tire molding machine. Then, a raw tire is molded. This raw tire is heated and pressed in a vulcanizer to obtain a tire.

In this pneumatic tire, the gas filled in the tire may be an inert gas such as air or nitrogen. The pneumatic tire of the present invention thus obtained has good fuel economy, is particularly excellent in fracture characteristics and wear resistance, and since the processability of the rubber composition is good, It has excellent productivity.

[0063]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. The physical properties of the polymer were measured according to the following methods.

<< Physical Properties of Polymer >> The number average molecular weight (Mn) and weight average molecular weight (Mw) of the polymer were measured by gel permeation chromatography [GPC; Tosoh HLC-8020, column; Tosoh GMH-XL]. (2
Main series)] and using the differential refractive index (RI),
It was carried out in terms of polystyrene using monodisperse polystyrene as a standard. The microstructure of the butadiene portion of the polymer was determined by the infrared method (Morero method), and the styrene unit content in the polymer was calculated from the integral ratio of the ¹ H-NMR spectrum.
The Mooney viscosity of the polymer was measured at 100 ° C. using an RLM-01 type tester manufactured by Toyo Seiki. Moreover, the physical properties of the vulcanized rubber were measured by the following methods.

<< Physical Properties of Vulcanized Rubber >> (1) Using a low exothermic viscoelasticity measuring device (manufactured by Rheometrics), tan δ (50) at a temperature of 50 ° C., strain of 5% and frequency of 15 Hz.
C) was measured. The smaller the tan δ (50 ° C), the lower the heat buildup. (2) Destructive physical properties (tensile strength) The strength (T _b ) at the time of cutting is defined by JIS K6301-1995.
Was measured according to. (3) Abrasion resistance A Lambourn abrasion tester was used to measure the amount of abrasion at a slip rate of 60% at room temperature, and the abrasion resistance of the control was set to 100, and the abrasion resistance index was expressed. The larger the index, the better.

Production Example 1 300 g of cyclohexane, 40 g of 1,3-butadiene, 10 g of styrene and 0.38 mmol of ditetrahydrofurylpropane were introduced into a dry, nitrogen-substituted 800 ml pressure-resistant glass container, and n was added thereto. -Butyl lithium (BuLi) 0.43 mmol after adding,
Was polymerized for 1.5 hours. From the start to the end of the polymerization, the polymerization system was uniformly transparent without any precipitation. The polymerization conversion rate was almost 100%.

A part of the polymerization solution was sampled, isopropyl alcohol was added, and the solid substance was dried to obtain a rubbery copolymer. The microstructure and molecular weight of this copolymer were measured. The results are shown in Table 1. After adding 0.43 mmol of 3-triethoxysilylpropyl succinic anhydride as a terminal modifier to this polymerization system, further addition of 3
The denaturation reaction was performed for 0 minutes. After this, add 2 more to the polymerization system.
Polymer A was obtained by adding 0.5 ml of a 5% by weight solution of 6-di-t-butyl-p-cresol (BHT) in isopropanol to stop the reaction, and further drying according to a conventional method. The analytical values of the obtained polymer are shown in Table 1.

Production Examples 2 to 5 The same as Production Example 1 except that the type of terminal modifying agent shown in Table 1 was used in place of 3-triethoxysilylpropyl succinic anhydride. Was carried out to prepare polymers B to E. The analytical values of the obtained polymers are shown in Table 1.

Production Example 6 In Production Example 1, 0.44 mmol of ditetrahydrofurylpropane, 0.50 mmol of lithium hexamethylene imide and 0.50 mmol of 3-triethoxysilylpropyl succinic anhydride were used as polymerization initiators. Polymer F was produced in the same manner as in Production Example 1 except that the above was used. The analytical values of the obtained polymer are shown in Table 1.

Production Examples 7 to 9 The same as Production Example 6 except that the type of terminal modifying agent shown in Table 1 was used in place of 3-triethoxysilylpropyl succinic anhydride. To produce polymers G to I. The analytical values of the obtained polymers are shown in Table 1.

Production Comparative Examples 1 to 3 300 g of cyclohexane, 40 g of 1,3-butadiene, 10 g of styrene and 0.38 mmol of ditetrahydrofurylpropane were charged into a 800 ml pressure-resistant glass container which had been dried and purged with nitrogen. After adding 0.43 mmol of n-butyllithium (BuLi) to
Was polymerized for 1.5 hours. From the start to the end of the polymerization, the polymerization system was uniformly transparent without any precipitation. The polymerization conversion rate was almost 100%.

A part of the polymerization solution was sampled, isopropyl alcohol was added, and the solid was dried to obtain a rubbery copolymer (Polymer J, Production Comparative Example 1). The microstructure, molecular weight and molecular weight distribution of this copolymer were measured. The results are shown in Table 1. After adding 0.43 mmol of tin tetrachloride as a terminal modifier to this polymerization system, a modification reaction was further carried out for 30 minutes. Thereafter, 0.5 ml of a 5% by weight solution of 2,6-di-t-butyl-p-cresol (BHT) in isopropanol was added to the polymerization system to stop the reaction, and the product was dried according to a conventional method. Polymer K (Production Comparative Example 2) was obtained.
The analytical values of the obtained polymer are shown in Table 1. Further, as the terminal modifier, 0.43 mmol of tetraethoxysilane was used instead of tin tetrachloride, and Polymer L (Production Comparative Example 3) was obtained in the same manner as above. The analytical values of the obtained polymer are shown in Table 1.

[0073]

[Table 1]

[0074]

[Table 2]

[0075]

[Table 3]

(Note) BaseMw: Weight average molecular weight (M
w) TotalMw: Weight average molecular weight after modification reaction (M
w) Mw / Mn: molecular weight distribution after modification reaction LHMI: lithium hexamethyleneimide TESSA: 3-triethoxysilylpropyl succinic anhydride TPSSA: 3-triphenoxysilylpropyl succinic anhydride DESSA: 3-diethoxy (methyl) silylpropyl Succinic anhydride TESAA: 3-triethoxysilylpropyl acetic anhydride TPSAA: 3-Triphenoxysilylpropyl acetic anhydride TTC: Tin tetrachloride TEOS: Tetraethoxysilane

Production Example 10 In a dry, nitrogen-substituted 800 ml pressure-resistant glass container, 300 g of cyclohexane, 32.5 g of 1,3-butadiene, 17.5 g of styrene, 0.023 mmol of potassium-t-amylate, and diamine were added. After injecting 0.030 mmol of tetrahydrofurylpropane and adding 0.45 mmol of n-butyllithium (BuLi) thereto, 5
Polymerization was carried out at 0 ° C. for 3 hours. From the start to the end of the polymerization, the polymerization system was uniformly transparent without any precipitation. The polymerization conversion rate was almost 100%. A part of the polymerization solution was sampled, isopropyl alcohol was added, and the solid matter was dried to obtain a rubbery copolymer. The microstructure and molecular weight of this copolymer were measured. The results are shown in Table 2.

In addition to this polymerization system, 3-
After adding 0.45 mmol of triethoxysilylpropyl succinic anhydride, a modification reaction was carried out for another 30 minutes. Thereafter, 0.5 ml of a 5% by weight solution of 2,6-di-t-butyl-p-cresol (BHT) in isopropanol was added to the polymerization system to stop the reaction, and the product was dried according to a conventional method. Polymer M was obtained. Table 2 shows the analytical values of the obtained polymer.

Production Comparative Examples 4 to 6 In an 800 ml pressure-resistant glass container which had been dried and purged with nitrogen, 300 g of cyclohexane, 32.5 g of 1,3-butadiene, 17.5 g of styrene and 0.023 mmol of potassium t-amylate were prepared. 0.030 mmol of ditetrahydrofurylpropane was injected, and 0.45 mmol of n-butyllithium (BuLi) was added thereto, and then 5
Polymerization was carried out at 0 ° C. for 3 hours. From the start to the end of the polymerization, the polymerization system was uniformly transparent without any precipitation. The polymerization conversion rate was almost 100%. A part of the polymerization solution was sampled, isopropyl alcohol was added, and the solid was dried to obtain a rubbery copolymer (Polymer N, Production Comparative Example 4). The microstructure, molecular weight and molecular weight distribution of this copolymer were measured. The results are shown in Table 2.

In this polymerization system, as a terminal modifying agent,
After adding 0.45 mmol of tin tetrachloride, a denaturing reaction was carried out for another 30 minutes. After this, the polymerization system is further added with 2,6-
Polymer O (Production Comparative Example 5) was obtained by adding 0.5 ml of a 5% by weight solution of di-t-butyl-p-cresol (BHT) in isopropanol to stop the reaction, and further drying according to a conventional method. It was Table 2 shows the analytical values of the obtained polymer. Further, as the terminal modifier, 0.45 mmol of tetraethoxysilane was used instead of tin tetrachloride, and Polymer P (Production Comparative Example 6) was obtained in the same manner as above. Table 2 shows the analytical values of the obtained polymer.

[0081]

[Table 4]

(Note) BaseMw, TotalMw, M
w / Mn, TESSA, TTC and TEOS are the same as the footnote in Table 1.

Production Example 11 300 g of cyclohexane, 50 g of 1,3-butadiene and 0.312 of ditetrahydrofurylpropane were placed in a dry, nitrogen-substituted 800 ml pressure-resistant glass container.
N-butyllithium (BuL
i) After adding 0.40 mmol, polymerization was carried out at 50 ° C. for 2 hours. From the start to the end of the polymerization, the polymerization system was uniformly transparent without any precipitation. Polymerization conversion rate is about 10
It was 0%.

A part of the polymerization solution was sampled, isopropyl alcohol was added, and the solid substance was dried to obtain a rubber-like polymer. The microstructure and molecular weight of this polymer were measured. The results are shown in Table 3. After adding 0.40 mmol of 3-triethoxysilylpropyl succinic anhydride as a terminal modifier to the polymerization system, modification reaction was further performed for 30 minutes. After this, 0.5 ml of a 5% by weight solution of 2,6-di-t-butyl-p-cresol (BHT) in isopropanol was added to the polymerization system to stop the reaction, and the polymer was dried according to a conventional method. Thus, a polymer Q was obtained. Table 3 shows the analytical values of the obtained polymer.

Production Comparative Examples 7 and 8 300 g of cyclohexane, 50 g of 1,3-butadiene and 0.312 of ditetrahydrofurylpropane were placed in a dry, nitrogen-substituted 800 ml pressure-resistant glass container.
N-butyllithium (BuL
i) After adding 0.40 mmol, polymerization was carried out at 50 ° C. for 2 hours. From the start to the end of the polymerization, the polymerization system was uniformly transparent without any precipitation. Polymerization conversion rate is about 10
It was 0%.

A part of the polymerization solution was sampled, isopropyl alcohol was added, and the solid was dried to obtain a rubbery polymer R (Production Comparative Example 7). The microstructure, molecular weight and molecular weight distribution of this polymer were measured. The results are shown in Table 3. After adding 0.40 mmol of tin tetrachloride as a terminal modifier to this polymerization system, a modification reaction was further carried out for 30 minutes. After this, 0.5 ml of a 5% by weight solution of 2,6-di-t-butyl-p-cresol (BHT) in isopropanol was added to the polymerization system to stop the reaction, and the polymer was dried according to a conventional method. Thus, a polymer S (Production Comparative Example 8) was obtained. Table 3 shows the analytical values of the obtained polymer.

[0087]

[Table 5]

(Note) BaseMw, TotalMw, M
w / Mn, TESSA and TTC are the same as the footnote in Table 1.

Examples 1 to 9 and Comparative Examples 1 to 3 Based on 100 parts by weight of the polymer of the type shown in Table 5, silica, aroma oil, stearic acid, a coupling agent and aging were used in accordance with the formulation 1 in Table 4. Prepare a masterbatch by blending the inhibitor 6C, and further add zinc white and vulcanization accelerator DP
An all-silica compound rubber composition was prepared by mixing G, DM, NS and sulfur. Each rubber composition at 160 ℃, 15
It was vulcanized under the condition of 1 minute, and the physical properties of the vulcanized rubber were measured. The results are shown in Table 5.

Examples 10 to 18 and Comparative Examples 4 to 6 Based on 100 parts by weight of the polymer shown in Table 6, carbon black, aroma oil,
Stearic acid and antioxidant 6C are blended to prepare a masterbatch, and zinc white, vulcanization accelerators DPG and D are added.
An all-carbon black compounded rubber composition was prepared by compounding M, NS and sulfur. 160 ° C for each rubber composition,
It was vulcanized under the condition of 15 minutes, and the physical properties of the vulcanized rubber were measured.
The results are shown in Table 6.

[0091]

[Table 6]

(Note) Silica: "Nipsil AQ" manufactured by Nippon Silica Industry Co., Ltd. Carbon black: "Seast KH (N339)" manufactured by Tokai Carbon Co., Ltd. Coupling agent: Sisilane coupling agent "Si69" manufactured by Degussa. Bis (3-triethoxysilylpropyl) tetrasulfide antioxidant 6C: N- (1,3-dimethylbutyl)
-N'-phenyl-p-phenylenediamine vulcanization accelerator DPG: diphenylguanidine vulcanization accelerator DM: mercaptobenzothiazyl disulfide vulcanization accelerator NS: Nt-butyl-2-benzothiazylsulfenamide

[0093]

[Table 7]

[0094]

[Table 8]

[0095]

[Table 9]

[0096]

[Table 10]

From Table 5, it can be seen that Examples 1 to 9 using the modified polymers A to I of the present invention are superior to Comparative Examples 1 to 3 in terms of low heat buildup and abrasion resistance. . Further, in Table 6, the polymer K effective for carbon black is shown.
It is understood that in the silica compounding system shown in Table 5, both the filler dispersibility and the reinforcing property are not sufficient. Further, in Table 5, the polymer L effective for silica is
It can be seen that in the carbon black compounding system shown in Table 6, both the filler dispersibility and the reinforcing property are not sufficient. As described above, with respect to the modified polymer according to the conventional technique, the modified polymer of the present invention has an excellent effect in both the silica compounding system and the carbon black compounding system,
In particular, the effect of improving wear resistance and low heat buildup in the silica compounding system is remarkable.

Example 19 and Comparative Examples 7 to 9 70 parts by weight of an SBR polymer of the type shown in Table 7 and NR3
4 parts to 100 parts by weight of the rubber component consisting of 0 parts by weight
A masterbatch was prepared by blending carbon black, silica, aroma oil, stearic acid, a coupling agent and an antioxidant 6C according to formulation 3 in the table, and further zinc white, vulcanization accelerators DPG, DM, NS and sulfur were prepared. Was blended to prepare a silica / carbon black blended rubber composition. Each rubber composition was vulcanized at 160 ° C. for 15 minutes, and the physical properties of the vulcanized rubber were measured. The results are shown in Table 7.

[0099]

[Table 11]

As is apparent from Table 7, Example 19
It can be seen that, as compared with Comparative Examples 7 to 9, low hysteresis characteristics due to a good filler dispersion effect and good wear resistance due to a reinforcing effect are provided.

Example 20 and Comparative Examples 10 and 11 70 parts by weight of a BR polymer of the type shown in Table 8 and NR30
To 100 parts by weight of a rubber component consisting of 1 part by weight, carbon black, silica, aroma oil, stearic acid, a coupling agent and an antioxidant 6C are added to prepare a masterbatch according to the formulation 3 in Table 4, Further, zinc white, a vulcanization accelerator DPG, DM, NS and sulfur were blended to prepare a silica / carbon black blended rubber composition. Each rubber composition was vulcanized at 160 ° C. for 15 minutes, and the physical properties of the vulcanized rubber were measured. The results are shown in Table 8.

[0102]

[Table 12]

As is clear from Table 8, the modified polymer of the present invention shown in Example 20 gives better physical properties than those of Comparative Examples 10 and 11.

[0104]

EFFECTS OF THE INVENTION According to the present invention, when used in both a rubber composition containing silica and carbon black, the interaction between silica and carbon black is enhanced.
It is possible to provide a modified diene-based polymer capable of simultaneously improving the breaking properties, abrasion resistance and low heat buildup and exhibiting good workability.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08L 13/00 C08L 13/00 15/00 15/00 F term (reference) 4J002 AC01X AC03X AC06X AC08X AC11W BB15X BB18X DA036 DJ016 EX087 FD010 FD016 FD020 FD140 FD150 GN00 4J100 AB00Q AB02Q AB03Q AB07Q AB16Q AS01P AS02P AS03P AS04P AS06P BA11H BA15H BA77H BC04Q BC43P CA01 CA04 CA31 HA61 HC78

Claims (10)

[Claims] 1. A molecule containing (a) a silicon-containing group and (b)
A modified diene-based polymer comprising at least one group selected from an acid anhydride group, a carboxyl group and a carbonyl group. 2. A silicon compound residue having at least one group selected from (a) a silicon-containing group and (b) an acid anhydride group, a carboxyl group and a carbonyl group is introduced at the terminal of a diene polymer. The modified diene polymer according to claim 1, wherein 3. The modified diene-based polymer according to claim 2, wherein a hydrocarbyloxysilane compound having an acid anhydride group in the molecule is reacted with the terminal of the diene-based polymer having an active terminal. 4. A hydrocarbyloxysilane compound having an acid anhydride group in the molecule is represented by the general formula (I): (In the formula, A ¹ is a divalent hydrocarbon group having 1 to 20 carbon atoms, R 1
^{1 to} R ³ are each independently a monovalent hydrocarbon group having 1 to 12 carbon atoms, R ⁴ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms, and R ³ and R ⁴ are To form a ring structure, n is 2 or 3, and each R ¹
O's may be the same or different. 4. The modified diene polymer according to claim 3, which has a structure represented by 5. A diene polymer having an active terminal is obtained by polymerizing a conjugated diene compound alone or a conjugated diene compound and an aromatic vinyl compound using an organic alkali metal compound as a polymerization initiator. The modified diene polymer according to 3 or 4. 6. The modified diene polymer according to claim 1, which has a Mooney viscosity (ML _{1 +} 4/100 ° C.) of 10 to 150. 7. A rubber composition comprising the modified diene-based polymer according to any one of claims 1 to 6. 8. A rubber component containing (A) at least 30% by weight of the modified diene polymer according to any one of claims 1 to 6, and (B) silica and / or carbon black 10 per 100 parts by weight thereof. The rubber composition according to claim 7, which comprises -100 parts by weight. 9. When at least silica is used as the component (B), coupling agents 1 to 2 are added to the silica.
The rubber composition according to claim 8, wherein the rubber composition contains 0% by weight. 10. A pneumatic tire comprising the rubber composition according to claim 7, 8 or 9 as a tread rubber.