JP2023174392A - Method for producing rubber composition, rubber composition and tire - Google Patents

Abstract

To provide a method for producing a rubber composition capable of obtaining a rubber composition which can improve the dispersibility of a filler and has excellent low-loss properties.SOLUTION: There is provided a method for producing a rubber composition comprising a rubber component (A) containing at least one selected from natural rubber and a synthetic diene rubber, a filler containing an inorganic filler (B), a silane coupling agent (C) and a vulcanization accelerator (D), wherein the rubber composition is kneaded in multiple stages, the rubber component (A), a part or the whole of the inorganic filler (B), a part or the whole of the silane coupling agent (C) and the vulcanization accelerator (D) are kneaded in a first stage of the kneading and the rubber component contains a modified copolymer modified by a modifying agent containing a compound represented by formula (1).SELECTED DRAWING: None

Description

The present invention relates to a method for producing a rubber composition, a rubber composition, and a tire.

In recent years, there has been an increasing demand for improved fuel efficiency in automobiles in connection with the worldwide movement toward regulating carbon dioxide emissions as a result of growing interest in environmental issues. In order to meet such demands, reduction in rolling resistance is also required in terms of tire performance. Conventionally, methods of optimizing the tire structure have been considered as a method to reduce the rolling resistance of tires, but the use of rubber compositions with lower heat generation (lower loss properties) as the rubber composition applied to tires has been considered. This is currently being implemented as one of the common methods.

As a method of obtaining a rubber composition having such low loss properties, a method of using an inorganic filler such as silica as a filler is known.
However, when compounding inorganic fillers such as silica in rubber compositions containing inorganic fillers, inorganic fillers, especially silica, tend to aggregate in the rubber composition (aggregation occurs due to hydroxyl groups on the surface of the silica). Various techniques have been developed to improve the dispersibility of fillers in rubber compositions.

For example, Patent Document 1 discloses that chemical interaction between the rubber component and the filler is enhanced by containing a rubber component having a diene rubber, a reinforcing filler, and a compound having a specific amidine structure. discloses a technique for improving the elastic modulus and tan δ by increasing the dispersibility of a reinforcing filler in a rubber composition.
Furthermore, Patent Document 2 discloses that a conjugated diene polymer modified with a modifier containing an oligosiloxane and a specific compound having a tertiary amino group is used together with a filler to increase the dispersibility of the filler. A technique for improving low loss properties has been disclosed.

However, in consideration of optimizing the performance of rubber to a higher level in the future, the technologies disclosed in Patent Documents 1 and 2 may not be able to provide sufficient low loss properties, and further technologies are needed. Improvement was desired.

Special table 2014-501827 publication JP 2021-085029 Publication

Therefore, an object of the present invention is to provide a method for producing a rubber composition that can improve the dispersibility of fillers and obtain a rubber composition with excellent low loss properties. Another object of the present invention is to provide a rubber composition with excellent low loss properties and a tire with reduced rolling resistance.

The present inventors conducted extensive research to solve the above problems. A conjugated diene polymer modified with a modifier containing oligosiloxane and a specific compound having a tertiary amino group is used as a rubber component, and a specific type of vulcanization accelerator is added in the first stage of the kneading process. In addition, it has been found that by properly performing the kneading step, it is possible to greatly improve the dispersibility of the filler and to improve low loss properties.

The method for producing a rubber composition of the present invention includes a rubber component (A) containing at least one selected from natural rubber and synthetic diene rubber, a filler containing an inorganic filler (B), and a silane cup. A method for producing a rubber composition comprising a ring agent (C) and a vulcanization accelerator (D),
kneading the rubber composition in multiple stages;
In the first step of the kneading, the rubber component (A), part or all of the inorganic filler (B), part or all of the silane coupling agent (C), and the vulcanization accelerator ( D) is kneaded;
The rubber component is characterized in that it contains a modified copolymer modified with a modifier containing a compound represented by formula (1).
By providing the above structure, it is possible to improve the dispersibility of the filler and obtain a rubber composition with excellent low loss properties.

Furthermore, in the method for producing a rubber composition of the present invention, the copolymer modified with the modifier containing the compound represented by formula (1) is a copolymer having a conjugated diene unit and an aromatic vinyl unit. The content of the aromatic vinyl unit in the copolymer is preferably 40% by mass or less. In this case, the low loss properties of the rubber composition can be further improved.

Furthermore, in the method for producing a rubber composition of the present invention, the vulcanization accelerator (D) is selected from guanidines, sulfenamides, thiazoles, thiurams, dithiocarbamates, thioureas, and xanthates. The vulcanization accelerator is preferably at least one vulcanization accelerator, and more preferably at least one guanidine vulcanization accelerator or at least one thiourea vulcanization accelerator. In this case, the coupling function of the silane coupling agent can be enhanced, and the low loss properties of the rubber composition can be further improved.

Furthermore, in the method for producing a rubber composition of the present invention, in the first step of kneading, all or a part of the rubber component (A), the inorganic filler (B), and the silane coupling agent (C) are mixed. After kneading all or part of the mixture, it is preferable to add the accelerator (D) and further knead the mixture. In this case, the coupling function of the silane coupling agent can be enhanced, and the low loss properties of the rubber composition can be further improved.

Furthermore, in the method for producing a rubber composition of the present invention, the maximum temperature of the rubber composition in the first stage of kneading is preferably 120 to 190°C. In this case, the coupling function of the silane coupling agent can be enhanced, and the low loss properties of the rubber composition can be further improved.

Further, in the method for producing a rubber composition of the present invention, the silane coupling agent (C) is at least one compound selected from the group consisting of compounds represented by the following general formulas (I) to (IV). is preferred.
(In the formula, R ¹ may be the same or different when there is a plurality of them, and each R 1 is a straight chain, cyclic or branched alkyl group having 1 to 8 carbon atoms, or a straight chain or branched alkoxyalkyl group having 2 to 8 carbon atoms. group or a hydrogen atom, and when there are multiple R ^2s , they may be the same or different, and each is a linear, cyclic, or branched alkyl group having 1 to 8 carbon atoms, and when there are multiple R ^3s , They may be the same or different, and each is a linear or branched alkylene group having 1 to 8 carbon atoms.a is 2 to 6 on average, p and r may be the same or different, and each has an average value of 2 to 6. The value is 0 to 3. However, both p and r cannot be 3.)
{In the formula, R ⁴ is -Cl, -Br, R ⁹ O-, R ⁹ C(=O)O-, R ⁹ R ¹⁰ C=NO-, R ⁹ R ¹⁰ CNO-, R ⁹ R ¹⁰ N- , and a monovalent group selected from -(OSiR ⁹ R ¹⁰ )h(OSiR ⁹ R ¹⁰ R ¹¹ ) (R ⁹ , R ¹⁰ and R ¹¹ are each a hydrogen atom or a monovalent group having 1 to 18 carbon atoms) h is a hydrocarbon group with an average value of 1 to 4), R ⁵ is R ⁴ , a hydrogen atom or a monovalent hydrocarbon group having 1 to 18 carbon atoms, and R ⁶ is R ⁴ , R ⁵ is a hydrogen atom or a -[O(R ¹² O)j] _0.5 - group (R ¹² is an alkylene group having 1 to 18 carbon atoms, and j is an integer of 1 to 4), R ⁷ is a divalent hydrocarbon group having 1 to 18 carbon atoms, and R ⁸ is a monovalent hydrocarbon group having 1 to 18 carbon atoms. x, y, and z are numbers that satisfy the following relationships: x+y+2z=3, 0≦x≦3, 0≦y≦2, and 0≦z≦1. }
{In the formula, R ¹³ may be the same or different when there are multiple R 13s, each of which is a straight chain, cyclic or branched alkyl group having 1 to 8 carbon atoms, or a straight chain or branched alkoxyalkyl group having 2 to 8 carbon atoms. group or a hydrogen atom, and when there are multiple R ^14s , they may be the same or different, and each is a linear, cyclic, or branched alkyl group having 1 to 8 carbon atoms, and when there are multiple R ^15s , They may be the same or different, and each is a straight chain or branched alkylene group having 1 to 8 carbon atoms.
R ¹⁶ is any of the general formulas (-S-R ¹⁷ -S-), (-R ¹⁸ -S _m1 -R ¹⁹ -) and (-R ²⁰ -S _m2 -R ²¹ -S _m3 -R ²² -) (R ¹⁷ to R ²² are each a divalent hydrocarbon group having 1 to 20 carbon atoms, a divalent aromatic group, or a divalent organic group containing a hetero element other than sulfur and oxygen) , m1, m2, and m3 each have an average value of 1 or more and less than 4.), the plurality of k's may be the same or different, each has an average value of 1 to 6, and s and t each have an average value of The value is 0 to 3. However, both s and t cannot be 3. }
{In the formula, R ²³ is a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, and multiple G's may be the same or different, and each is an alkanediyl group or an alkenediyl group having 1 to 9 carbon atoms. , the plurality of Z ^a may be the same or different, each is a functional group capable of bonding with two silicon atoms, and [-0-] _0.5 , [-0-G-] _{0 .5} and [-O-G-O-] _0.5 , and the plurality of Z ^b 's may be the same or different, and each is a functional group that can bond to two silicon atoms. and is a functional group represented by [-O-G-O-] _0.5 , and the plurality of Z ^c may be the same or different, and each represents -Cl, -Br, -OR ^a , R ^a A functional group selected from C(=O)O-, R ^a R ^b C=NO-, R ^a R ^b N-, R ^a - and HO-G-O- (G matches the above notation). R ^a and R ^b each represent a straight chain, branched or cyclic alkyl group having 1 to 20 carbon atoms. m, n, u, v and w are 1≦m≦20, 0≦n≦20, 0≦u≦3, 0≦v≦2, 0≦w≦1, and (u/2)+v+2w =2 or 3. When there are multiple A parts, Z ^a _u , Z ^b _v and Z ^c _w in the multiple A parts may be the same or different, and when there are multiple B parts, Z ^a in the multiple B parts _u , Z ^b _v and Z ^c _w may be the same or different. }
In this case, workability and wear resistance during rubber processing can be improved.

Furthermore, in the method for producing a rubber composition of the present invention, the inorganic filler (B) is preferably silica. In this case, the low loss properties of the rubber composition can be further improved.

Furthermore, in the method for producing a rubber composition of the present invention, it is preferable that the filler further contains carbon black. In this case, the abrasion resistance of the rubber composition can be improved.

Furthermore, in the method for producing a rubber composition of the present invention, the modifier is preferably one of formulas (1a) to (1e). In this case, the low loss properties of the rubber composition can be further improved.

Furthermore, in the method for producing a rubber composition of the present invention, the modified copolymer is preferably a modified copolymer further modified with a modifier containing a compound represented by formula (2). In this case, the low loss properties of the rubber composition can be further improved.
(In formula (2), R ₁ to R ₃ each independently represent hydrogen; an alkyl group having 1 to 30 carbon atoms; an alkenyl group having 2 to 30 carbon atoms; an alkynyl group having 2 to 30 carbon atoms; Heteroalkyl group having 1 to 30 carbon atoms, heteroalkenyl group having 2 to 30 carbon atoms; heteroalkynyl group having 2 to 30 carbon atoms; cycloalkyl group having 5 to 30 carbon atoms; aryl group having 6 to 30 carbon atoms; or carbon number 3 to 30 heterocyclic group; R ₄ is a single bond; a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms; a substituted or unsubstituted cyclocarbon group having 5 to 20 carbon atoms; Alkylene group; or a substituted or unsubstituted arylene group having 5 to 20 carbon atoms, where the substituent is an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or It is an aryl group having 6 to 20 carbon atoms, and R ₅ is an alkyl group having 1 to 30 carbon atoms; an alkenyl group having 2 to 30 carbon atoms; an alkynyl group having 2 to 30 carbon atoms; a heteroalkyl group having 1 to 30 carbon atoms; group; heteroalkenyl group having 2 to 30 carbon atoms; heteroalkynyl group having 2 to 30 carbon atoms; cycloalkyl group having 5 to 30 carbon atoms; aryl group having 6 to 30 carbon atoms; heterocyclic group having 3 to 30 carbon atoms or a functional group represented by the following chemical formula (2a) or (2b), where n is an integer of 1 to 5, and at least one of R ₅ is represented by the following chemical formula (2a) or (2b). In the functional group represented, when n is an integer of 2 to 5, a plurality of R _5s may be the same or different from each other.
In formula (2a), R ₆ is a substituent-substituted or unsubstituted alkylene group having 1 to 20 carbon atoms; a substituent substituted or unsubstituted cycloalkylene group having 5 to 20 carbon atoms; or a substituent substituted or an unsubstituted arylene group having 6 to 20 carbon atoms, where the above substituent is an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or an arylene group having 6 to 20 carbon atoms. R ₇ and R ₈ are each independently an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or an aryl group having 6 to 20 carbon atoms substituted or unsubstituted. an alkylene group having 1 to 20 carbon atoms; R ₉ is hydrogen; an alkyl group having 1 to 30 carbon atoms; an alkenyl group having 2 to 30 carbon atoms; an alkynyl group having 2 to 30 carbon atoms; a heteroalkyl group having 1 to 30 carbon atoms. group; heteroalkenyl group having 2 to 30 carbon atoms; heteroalkynyl group having 2 to 30 carbon atoms; cycloalkyl group having 5 to 30 carbon atoms; aryl group having 6 to 30 carbon atoms; heterocyclic group having 3 to 30 carbon atoms and X is an N, O or S atom, and when X is O or S, R9 is absent.
In formula (2b), R ₁₀ is a substituent-substituted or unsubstituted alkylene group having 1 to 20 carbon atoms; a substituent substituted or unsubstituted cycloalkylene group having 5 to 20 carbon atoms; or a substituent substituted or an unsubstituted arylene group having 6 to 20 carbon atoms, where the above substituent is an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or an aryl group having 6 to 20 carbon atoms. and R ₁₁ and R ₁₂ are each independently an alkyl group having 1 to 30 carbon atoms; an alkenyl group having 2 to 30 carbon atoms; an alkynyl group having 2 to 30 carbon atoms; a heteroalkyl group having 1 to 30 carbon atoms; Heteroalkenyl group having 2 to 30 carbon atoms; Heteroalkynyl group having 2 to 30 carbon atoms; Cycloalkyl group having 5 to 30 carbon atoms; Aryl group having 6 to 30 carbon atoms; Heterocyclic group having 3 to 30 carbon atoms . )

The rubber composition of the present invention is characterized in that it is obtained by the method for manufacturing the rubber composition of the present invention described above.
By providing the above configuration, excellent low loss properties can be achieved.

The tire of the present invention is characterized by using the rubber composition of the present invention described above.
By providing the above configuration, an excellent rolling resistance reduction effect can be achieved.

According to the present invention, it is possible to provide a method for producing a rubber composition, which can improve the dispersibility of fillers and obtain a rubber composition with excellent low loss properties. Further, according to the present invention, it is possible to provide a rubber composition with excellent low loss properties and a tire with reduced rolling resistance.

Below, one embodiment of the manufacturing method of the rubber composition, the rubber composition, and the tire of the present invention will be specifically illustrated and explained.
<Method for producing rubber composition>
The method for producing a rubber composition of the present invention includes a rubber component (A) containing at least one selected from natural rubber and synthetic diene rubber, a filler containing an inorganic filler (B), and a silane cup. This is a method for producing a rubber composition containing a ring agent (C) and a vulcanization accelerator (D).
The method for producing a rubber composition of the present invention includes kneading the rubber composition in multiple stages,
In the first step of the kneading, the rubber component (A), part or all of the inorganic filler (B), part or all of the silane coupling agent (C), and the vulcanization accelerator ( D) is kneaded;
The rubber component is characterized in that it contains a modified copolymer modified with a modifier containing a compound represented by formula (1).
(In the formula, R ₁ to R ₈ are each independently an alkyl group having 1 to 20 carbon atoms; L ₁ and L ₂ are each independently an alkylene group having 1 to 20 carbon atoms; n is an integer from 2 to 4.)

As the rubber component (A), a conjugated diene polymer modified with a modifier containing a compound represented by the formula (1) containing an oligosiloxane and a tertiary amino group, which are filler-affinity functional groups, is used. In addition to improving the dispersibility of the filler (C) such as silica, the use of the silane coupling agent (C) can improve the coupling function of the silane coupling agent (C) by adjusting the kneaded material prepared in the first step of the kneading. As a result of increasing the activity and increasing the dispersibility of the filler (C) in the rubber composition, these synergistic effects can greatly improve the low heat generation property of the obtained rubber composition.

Here, in the kneading step, there is no particular restriction on the kneading device used for kneading, and it can be appropriately selected depending on the purpose.
For example, a single-screw kneading extruder; a multi-screw kneading extruder (continuous kneading device); a kneading machine with intermeshing or non-intermeshing rotating rotors such as Banbury mixer, intermix, kneader, etc.; rolls (batch-type kneading device); ); etc.
Further, various conditions such as the rotational speed of the rotor, ram pressure, kneading temperature, and type of kneading device in the kneading can be selected as appropriate.

In the method for producing a rubber composition of the present invention, as described above, the rubber composition is kneaded in multiple stages.
In the first step of the kneading, the rubber component (A), part or all of the inorganic filler (B), part or all of the silane coupling agent (C), and the vulcanization accelerator The agent (D) is kneaded.
Here, the reason why the vulcanization accelerator (D) is added in the first stage of kneading is to enhance the activity of the coupling function of the silane coupling agent (C).

Further, in the method for producing a rubber composition of the present invention, in the first step of the kneading, all or a part of the rubber component (A), the inorganic filler (B), and the silane coupling agent (C) are mixed. Adding the vulcanization accelerator (D) after kneading all or part of the vulcanization accelerator (D) and further kneading further suppresses the reduction in the effect of improving the coupling function activity due to the combination of the vulcanization accelerator (D). Preferred because it can be done.
That is, after the reaction between the inorganic filler (B) and the silane coupling agent (C) has sufficiently progressed, the reaction between the silane coupling agent (C) and the rubber component (A) is allowed to proceed. This is because it can be done.

Further, in the first stage of kneading, after adding all or part of the rubber component (A), the inorganic filler (B), and the silane coupling agent (C), It is more preferable to set the time until the addition of the vulcanization accelerator (D) in the middle of the first step to 10 to 180 seconds. The lower limit of this time is more preferably 30 seconds or more, and the upper limit is more preferably 150 seconds or less, even more preferably 120 seconds or less. If this time is 10 seconds or more, the reaction between (B) and (C) can proceed sufficiently. Even if this time exceeds 180 seconds, the reaction between (B) and (C) has already progressed sufficiently, so it is difficult to enjoy any further effects, so it is preferable to set the upper limit to 180 seconds.

In the present invention, it is preferable that the molar amount X of the organic acid in the rubber composition in the first stage of kneading has the relationship expressed by the following formula [3] with respect to the molar amount Y of the vulcanization accelerator (D). . This is to suitably suppress the reduction in the activity improvement effect of the coupling function due to the presence of a large amount of organic acid due to the addition of the accelerator (D).
0≦X≦1.5×Y ...[3]
In order to reduce the amount of organic acid in the first stage (X) of kneading, it is preferable that the organic acid is added in the second stage of kneading or later.

In the production method of the present invention, the maximum temperature of the rubber composition in the first stage of kneading is preferably 120 to 190°C. This is to allow the reaction between the inorganic filler (B) and the silane coupling agent (C) to proceed sufficiently. From this point of view, the maximum temperature of the rubber composition in the first stage of kneading is more preferably 130 to 190°C, and even more preferably 140 to 180°C.

In the manufacturing method of the present invention, the kneading step includes at least a first stage of kneading that does not contain any other vulcanizing agent, etc. except for the vulcanization accelerator (D), and a final stage of kneading that contains a vulcanizing agent, etc. It includes two stages, and may include an intermediate stage of kneading which does not contain any other vulcanizing agent except the accelerator (D), if necessary. Here, the vulcanizing agent and the like refer to a vulcanizing agent and a vulcanization accelerator.
The first stage of kneading refers to the first stage of kneading both the rubber component (A), the inorganic filler (B) and the silane coupling agent (C). The step of kneading A) and a filler other than the inorganic filler (B) or the step of pre-kneading only the rubber component (A) is not included.

As mentioned above, the method for producing a rubber composition of the present invention comprises a rubber component (A) containing at least one selected from natural rubber and synthetic diene rubber, and a filler containing an inorganic filler (B). silane coupling agent (C), and a vulcanization accelerator (D).
Each component constituting the rubber composition will be explained below.

(rubber component)
The rubber composition produced by the production method of the present invention includes a rubber component (A) containing at least one selected from natural rubber and synthetic diene rubber.
By containing at least one selected from natural rubber and synthetic diene rubber as the rubber component, the abrasion resistance of the rubber composition can be improved. Moreover, the dispersibility of the inorganic filler (B) can be improved by modifying it with a modifier containing a compound represented by formula (1) described below.

The type of synthetic diene rubber contained in the rubber component (A) is not particularly limited, and can be appropriately selected depending on the required performance. For example, butadiene rubber (BR) (BR means polybutadiene, which is a polymer of 1,3-butadiene, and does not include copolymers of butadiene and other polymers, etc.), isoprene rubber (IR), styrene butadiene rubber (SBR), styrene isoprene butadiene rubber (SIBR), chloroprene rubber (CR), acrylonitrile butadiene rubber (NBR), and the like.

Note that the natural rubber and the synthetic diene rubber may be composed only of unmodified rubber or may be composed of modified rubber.
However, in the present invention, the synthetic diene rubber contained in the rubber component (A) does not contain a modified copolymer modified with a modifier containing a compound represented by formula (1) described below. shall be. Therefore, natural rubber and synthetic diene rubber modified with a modifier containing a compound represented by formula (1) described below are included in the modified copolymer described below.

Further, the rubber component (A) may contain rubber other than diene rubber (non-diene rubber) as long as it does not impair the object of the present invention.
Examples of the non-diene rubber include ethylene propylene diene rubber (EPDM), ethylene propylene rubber (EPM), butyl rubber (IIR), and the like.

In the rubber composition of the present invention, the rubber component is a modified copolymer (hereinafter simply referred to as "modified conjugated diene polymer") modified with a modifier containing a compound represented by formula (1). ).
As the rubber component (A), a conjugated diene polymer modified with a modifier containing a compound represented by the formula (1) containing an oligosiloxane and a tertiary amino group, which are filler-affinity functional groups, is used. By using it, the dispersibility of the inorganic filler (B) such as silica can be improved.
As a result, the rubber composition of the present invention has greatly improved low heat generation properties and improved filler dispersibility, so it has other properties such as reinforcing properties, handling stability when applied to tires, processability, etc. There is no deterioration in physical properties.

In the formula (1), R ₁ to R ₈ are each independently an alkyl group having 1 to 20 carbon atoms; L ₁ and L ₂ are each independently an alkylene group having 1 to 20 carbon atoms. ; n is an integer from 2 to 4.

Specifically, in the formula (1), R ₁ to R ₄ may each independently be a substituted or unsubstituted alkyl group having ₁ to ₂₀ carbon atoms; In the case of 12 aryl group, aryloxy group with 6 to 12 carbon atoms, alkanoyloxy group with 2 to 12 carbon atoms (alkanoyl, RaCOO ^- , in this case, Ra is an alkyl group with 1 to 9 carbon atoms), 7 carbon atoms It may be substituted with one or more substituents selected from the group consisting of an aralkyloxy group having 1 to 13 carbon atoms, an arylalkyl group having 7 to 13 carbon atoms, and an alkylaryl group having 7 to 13 carbon atoms.
More specifically, R ₁ to R ₄ may be substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms, and even more specifically, R ₁ to R ₄ may each independently be substituted or unsubstituted. It may also be an unsubstituted alkyl group having 1 to 6 carbon atoms.

Furthermore, in the formula (1), R ₅ to R ₈ are each independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, specifically, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms. 10 alkyl groups, more specifically may be substituted or unsubstituted alkyl groups having 1 to 6 carbon atoms, and when substituted, the substituents as previously explained for R ₁ to R ₄ May be replaced. When the above R ₅ to R ₈ are not alkyl groups but hydrolyzable substituents, the bonds of NR ₅ R ₆ and NR ₇ R ₈ are hydrolyzed to N-H in the presence of water, resulting in polymerization. It can have a negative effect on the processability of coalescence.

More specifically, in the compound represented by formula (1), R ₁ to R ₄ are methyl groups or ethyl groups, and R ₅ to R ₈ are alkyl groups having 1 to 10 carbon atoms. can.

In the present invention, the amino groups in the compound represented by formula (1), ie, NR ₅ R ₆ and NR ₇ R ₈ , are preferably tertiary amino groups. The tertiary amino group allows the compound represented by formula (1) to have even better processability when used as a modifier.
Note that if a protecting group for protecting an amino group or hydrogen is bonded to R ₅ to R ₈ , it may be difficult to achieve the effect of the compound represented by formula (1). There is sex. When hydrogen is bonded, the anion reacts with hydrogen during the modification process and loses its reactivity, making the modification reaction itself impossible. When a protecting group is bound, the modification reaction takes place, but the end of the polymer It is deprotected by hydrolysis during post-processing to become a primary or secondary amino group, and the deprotected primary or secondary amino group causes high viscosity of the compound during subsequent compounding. , which may cause a decrease in workability.

Furthermore, L ₁ and L ₂ in the compound represented by formula (1) are each independently substituted or unsubstituted alkylene groups having 1 to 20 carbon atoms.
More specifically, L ₁ and L ₂ each independently represent an alkylene group having 1 to 10 carbon atoms, and more specifically, an alkylene group having 1 to 6 carbon atoms such as a methylene group, an ethylene group, or a propylene group. It can be based on

Regarding L ₁ and L ₂ in the compound represented by formula (1), the closer the distance between the Si atom and the N atom in the molecule, the better the effect. However, if Si is directly bonded to N, the bond between Si and N may be broken during the subsequent treatment process, and the secondary amino groups generated at this time may be washed away by water during the post-treatment. In the modified conjugated diene polymers that are produced, it is difficult to bond with the silica filler due to the amino group member that promotes bonding with the inorganic filler (B) such as silica, and as a result, the dispersant The dispersion effect may be reduced. Considering the improvement effect due to the length of the bond between Si and N, L ₁ and L ₂ each independently have a carbon number of 1 to 3, such as a methylene group, an ethylene group, or a propylene group. More preferably, it is an alkylene group, and more specifically, it can be a propylene group. Furthermore, L ₁ and L ₂ may be substituted with the substituents described above for R ₁ to R ₄ .

Further, the compound represented by the formula (1) is preferably, for example, any one of the compounds represented by the following formulas (1a) to (1e). This is because superior low heat generation properties can be achieved.

In the modifier of the present invention, the compound represented by the formula (1) has an alkoxysilane structure bonded to the activated terminal of the conjugated diene polymer, and a Si-O-Si structure and three or more bonded to the terminal. By showing affinity for fillers such as silica, the amino groups of silica promote bonding between fillers and modified conjugated diene polymers compared to conventional modifiers containing one amino group in the molecule. I can do it.
In addition, the degree of bonding of the activated terminals of the conjugated diene polymer is uniform, and when observing changes in molecular weight distribution before and after coupling, it is found that the molecular weight distribution does not become larger after coupling and remains constant compared to before.
Therefore, the physical properties of the modified conjugated diene polymer itself do not deteriorate, and the agglomeration of the filler in the rubber composition can be prevented and the dispersibility of the filler can be improved, thereby improving the processability of the rubber composition. I can do it. These effects particularly make it possible to improve the fuel efficiency, wear characteristics, and braking characteristics in a well-balanced manner when the rubber composition is applied to tires.

Note that the compound represented by the formula (1) can be produced through a condensation reaction represented by Reaction Formula 1 below.

In the reaction formula 1, R ₁ to R ₈ , L ₁ and L ₂ , and n are the same as those defined in the formula (1) above, and R' and R'' are It is an optional substituent that has no effect. For example, R' and R'' can each independently be the same as any one of R ₁ to R ₄ .

The reaction of Reaction Formula 1 is carried out under acidic conditions, and any acid that is generally used in condensation reactions can be used without limitation. Those skilled in the art can select the most suitable acid according to various process variables such as the type of reactor in which the reaction is carried out, starting materials, and reaction temperature.

Various copolymers can be used as the copolymer modified with a modifier containing the compound represented by formula (1), but a copolymer having a conjugated diene unit and an aromatic vinyl unit may be used. It is preferable that there be.
Note that the conjugated diene units and aromatic vinyl units may be randomly arranged and bonded to form a random copolymer.

In the rubber composition of the present invention, the content of aromatic vinyl units in the copolymer (the mass occupied by the aromatic vinyl units relative to the total mass of the copolymer) is preferably 40% by mass or less. This is because the low heat generation property of the rubber composition can be further improved. From the same viewpoint, the content of the aromatic vinyl unit is preferably 30% by mass or less, more preferably 20% by mass or less. In addition, from the viewpoint of maintaining good handling stability and wear resistance when the rubber composition is applied to tires, the content of aromatic vinyl units in the copolymer should be 3% by mass or more. It is preferable that there be.

Here, the type of conjugated diene monomer that becomes the conjugated diene unit is not particularly limited. For example, selected from the group consisting of 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, piperylene, 3-butyl-1,3-octadiene, isoprene and 2-phenyl-1,3-butadiene. One or more types can be used.

Furthermore, there are no particular limitations on the type of aromatic vinyl monomer that becomes the aromatic vinyl unit. For example, styrene, α-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-propylstyrene, 1-vinylnaphthalene, 4-cyclohexylstyrene, 4-(p-methylphenyl)styrene and 1-vinyl-5- One or more types selected from the group consisting of hexylnaphthalene can be used.

Furthermore, the copolymer of the modified copolymer can be a combination of the above-mentioned conjugated diene monomer and aromatic vinyl monomer, but among them, styrene-butadiene rubber is preferable. . This is because excellent low heat generation properties can be achieved more reliably without deteriorating other performances, and the wet performance when applied to tires is also excellent.

Further, the modified copolymer may have a narrow molecular weight distribution: Mw/Mn (also referred to as polydispersity index (PDI)) of 1.1 to 3.0. If the molecular weight distribution of the modified copolymer exceeds 3.0 or is less than 1.1, the tensile properties and viscoelasticity may deteriorate when applied to a rubber composition. Considering the remarkable effect of improving the tensile properties and viscoelasticity of the polymer by controlling the molecular weight distribution of the modified copolymer, the molecular weight distribution of the modified copolymer is preferably 1.3 to 2.0. In addition, by using the modifier, the modified copolymer has a molecular weight distribution similar to that of the copolymer before modification.

Note that the molecular weight distribution of the modified copolymer can be calculated from the ratio of weight average molecular weight (Mw) to log average molecular weight (Mn) (Mw/Mn). At this time, the number average molecular weight (Mn) is the common average of the individual polymer molecular weights calculated by measuring the molecular weights of n polymer molecules, finding the total of these molecular weights, and dividing by n. , the weight average molecular weight (Mw) represents the molecular weight distribution of the polymer composition. The average overall molecular weight can be expressed in grams per mole (g/mol).
Further, in the present invention, the weight average molecular weight and the number average molecular weight are polystyrene equivalent molecular weights analyzed by gel permeation chromatography (GPC).

In addition, the modified copolymer satisfies the above molecular weight distribution conditions and has a number average molecular weight (Mn) of 50,000 g/mol to 2,000,000 g/mol, more specifically, 200,000 g/mol. It can be from mol to 800,000g/mol. The weight average molecular weight (Mw) of the modified copolymer can be from 100,000 g/mol to 4,000,000 g/mol, more specifically from 300,000 g/mol to 1,500,000 g/mol.

When the weight average molecular weight (Mw) of the modified copolymer is less than 100,000 g/mol or the number average molecular weight (Mn) is less than 50,000 g/mol, the tensile properties when applied to a rubber composition are There is a risk of deterioration. In addition, if the weight average molecular weight (Mw) exceeds 4,000,000 g/mol or the number average molecular weight (Mn) exceeds 2,000,000 g/mol, the processability of the modified copolymer may be reduced. The properties of the rubber composition may deteriorate, making kneading difficult and making it difficult to sufficiently improve the physical properties of the rubber composition.
More specifically, when the modified copolymer according to one embodiment of the present invention simultaneously satisfies the conditions of weight average molecular weight (Mw) and number average molecular weight (Mn) in addition to the molecular weight distribution, When applied to a rubber composition, the viscoelasticity and processability of the rubber composition can be improved in a well-balanced manner.

Further, the present invention can provide a method for producing the modified copolymer using a modifier containing the compound represented by the formula (1).
Specifically, in the method for producing the modified copolymer, 1) an aromatic vinyl monomer and a conjugated diene monomer are polymerized in a hydrocarbon solvent in the presence of an organic alkali metal compound, and at least The method may include the steps of preparing an active polymer having an alkali metal bonded to one end thereof, and 2) reacting the active polymer with a modifier including a compound represented by Formula 1.

The above step 1) is a step for producing an active polymer having an alkali metal bonded to at least one terminal, in which an aromatic vinyl monomer is prepared in a hydrocarbon solvent in the presence of an organic alkali metal compound. This can be carried out by polymerizing a conjugated diene monomer and a conjugated diene monomer.

Note that the hydrocarbon solvent is not particularly limited, and for example, one or more selected from the group consisting of n-pentane, n-hexane, n-heptane, isooctane, cyclohexane, toluene, benzene, and xylene. can be used.

The organic alkali metal compound can be used in an amount of 0.1 mmol to 1.0 mmol based on 100 g of the total monomer.
The organic alkali metal compound is not particularly limited, but includes, for example, methyllithium, ethyllithium, propyllithium, n-butyllithium, s-butyllithium, t-butyllithium, hexyllithium, n-decyllithium, t-octyllithium, phenyllithium, 1-naphthyllithium, n-eicosyllithium, 4-butylphenyllithium, 4-tolyllithium, cyclohexyllithium, 3,5-di-n-heptylcyclohexyllithium, 4-cyclopentyllithium, 1 selected from the group consisting of naphthyl sodium, naphthyl potassium, lithium alkoxide, sodium alkoxide, potassium alkoxide, lithium sulfonate, sodium sulfonate, potassium sulfonate, lithium amide, sodium amide, potassium amide and lithium isopropyl amide More than one species can be used.

The polymerization in step 1) may be carried out by further adding a polar additive if necessary, and the polar additive is 0.001 parts by weight based on 100 parts by weight of the monomers. It can be added in an amount of ~1.0 part by weight. Specifically, it can be added in an amount of 0.005 part by weight to 0.5 part by weight, more specifically 0.01 part by weight to 0.3 part by weight, based on 100 parts by weight of the total monomer.
Examples of the polar additives include tetrahydrofuran, ditetrahydrofurylpropane, diethyl ether, cycloamal ether, dipropyl ether, ethylene dimethyl ether, ethylene dimethyl ether, diethyl glycol, dimethyl ether, tertiary butoxyethoxyethane, bis(3-dimethylamino) One or more selected from the group consisting of (ethyl)ether, (dimethylaminoethyl)ethyl ether, trimethylamine, triethylamine, tripropylamine, and tetramethylethylenediamine can be used.

In addition, in the above production method, when copolymerizing a conjugated diene monomer and an aromatic vinyl monomer by using the polar additive, random copolymerization is performed by compensating for the difference in reaction rate. can be induced so that coalescence can be easily formed.

Further, the polymerization in step 1) can be performed through adiabatic polymerization or isothermal polymerization.
Here, the adiabatic polymerization refers to a polymerization method that includes a step of adding the organic alkali metal compound and then polymerizing it with the heat of self-reaction without optionally applying heat, and the isothermal polymerization refers to the step of polymerizing the organic alkali metal compound using the heat of self-reaction without applying any heat. This is a polymerization method in which the temperature of the polymer is maintained constant by adding heat or removing heat after the compound is added.

Furthermore, the polymerization may be carried out at a temperature range of 20°C to 200°C, specifically 0°C to 150°C, more specifically 10°C to 120°C. can.

Further, step 2) is a modification reaction step in which the active polymer is reacted with a modifier containing the compound represented by the formula (1), in order to produce a modified copolymer.

At this time, the modifier containing the compound represented by the formula (1) may be the same as described above. The compound represented by formula (1) can be used in a proportion of 0.1 to 2.0 mol per 1 mol of the organic alkali metal compound.
Furthermore, the reaction in step 2) above is a modification reaction for introducing a functional group into the polymer, and each of the above reactions is carried out at a temperature range of 0°C to 90°C for 1 minute to 5 hours. It may be.

The above-described manufacturing method may further include one or more steps of recovering the solvent and unreacted monomer and drying after the step 2), if necessary.

Further, as described above, the modified copolymer is modified with a modifier containing the compound represented by formula (1), but it is further modified with a modifier containing the compound represented by formula (2). It is preferable that Since the dispersibility of the filler in the rubber composition can be further improved, it is possible to achieve both low heat generation and a higher level of handling stability when applied to tires, and further improve wear resistance and processability. You can also do it.

In the above formula (2), R ₁ to R ₃ each independently represent hydrogen; an alkyl group having 1 to 30 carbon atoms; an alkenyl group having 2 to 30 carbon atoms; an alkynyl group having 2 to 30 carbon atoms; Heteroalkyl group having 1 to 30 carbon atoms, heteroalkenyl group having 2 to 30 carbon atoms; heteroalkynyl group having 2 to 30 carbon atoms; cycloalkyl group having 5 to 30 carbon atoms; aryl group having 6 to 30 carbon atoms; or carbon number 3 to 30 heterocyclic group; R ₄ is a single bond; a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms; a substituted or unsubstituted cyclocarbon group having 5 to 20 carbon atoms; Alkylene group; or a substituted or unsubstituted arylene group having 5 to 20 carbon atoms, where the substituent is an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or It is an aryl group having 6 to 20 carbon atoms, and R ₅ is an alkyl group having 1 to 30 carbon atoms; an alkenyl group having 2 to 30 carbon atoms; an alkynyl group having 2 to 30 carbon atoms; a heteroalkyl group having 1 to 30 carbon atoms; group; heteroalkenyl group having 2 to 30 carbon atoms; heteroalkynyl group having 2 to 30 carbon atoms; cycloalkyl group having 5 to 30 carbon atoms; aryl group having 6 to 30 carbon atoms; heterocyclic group having 3 to 30 carbon atoms or a functional group represented by the following chemical formula (2a) or (2b), where n is an integer of 1 to 5, and at least one of R ₅ is represented by the following chemical formula (2a) or (2b). In the functional group represented, when n is an integer of 2 to 5, a plurality of R _5s may be the same or different from each other.

In the above formula (2a), R ₆ is a substituent-substituted or unsubstituted alkylene group having 1 to 20 carbon atoms; a substituent substituted or unsubstituted cycloalkylene group having 5 to 20 carbon atoms; or a substituent A substituted or unsubstituted arylene group having 6 to 20 carbon atoms, where the substituent is an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or a cycloalkyl group having 6 to 20 carbon atoms. is an aryl group, and R ₇ and R ₈ are each independently an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or an aryl group having 6 to 20 carbon atoms substituted or unsubstituted. R ₉ is an alkylene group having 1 to 20 carbon atoms; R 9 is hydrogen; an alkyl group having 1 to 30 carbon atoms; an alkenyl group having 2 to 30 carbon atoms; an alkynyl group having 2 to 30 carbon atoms; a hetero group having 1 to 30 carbon atoms; Alkyl group; heteroalkenyl group having 2 to 30 carbon atoms; heteroalkynyl group having 2 to 30 carbon atoms; cycloalkyl group having 5 to 30 carbon atoms; aryl group having 6 to 30 carbon atoms; heterocycle having 3 to 30 carbon atoms group, X is an N, O or S atom, and when X is O or S, R9 is absent.

In the above formula (2b), R ₁₀ is a substituent-substituted or unsubstituted alkylene group having 1 to 20 carbon atoms; a substituent substituted or unsubstituted cycloalkylene group having 5 to 20 carbon atoms; or a substituent A substituted or unsubstituted arylene group having 6 to 20 carbon atoms, where the above substituent is an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or an arylene group having 6 to 20 carbon atoms. R ₁₁ and R ₁₂ each independently represent an alkyl group having 1 to 30 carbon atoms; an alkenyl group having 2 to 30 carbon atoms; an alkynyl group having 2 to 30 carbon atoms; a heteroalkyl group having 1 to 30 carbon atoms; ; Heteroalkenyl group having 2 to 30 carbon atoms; Heteroalkynyl group having 2 to 30 carbon atoms; Cycloalkyl group having 5 to 30 carbon atoms; Aryl group having 6 to 30 carbon atoms; Heterocyclic group having 3 to 30 carbon atoms; be.

In addition, in the compound represented by the above formula (2), R ₁ to R ₃ are independently hydrogen; an alkyl group having 1 to 10 carbon atoms; an alkenyl group having 2 to 10 carbon atoms; or an alkenyl group having 2 to 10 carbon atoms; is an alkynyl group having 1 to 10 carbon atoms; R ₄ is a single bond; or an unsubstituted alkylene group having 1 to 10 carbon atoms; R ₅ is an alkyl group having 1 to 10 carbon atoms; an alkenyl group having 2 to 10 carbon atoms ; an alkynyl group having 2 to 10 carbon atoms; or a functional group represented by the following chemical formula (2a) or (2b); In the above chemical formula (2a), R ₆ is an unsubstituted group having 1 to 10 carbon atoms; is an alkylene group, R ₇ and R ₈ are each independently an unsubstituted alkylene group having 1 to 10 carbon atoms; R ₇ is an alkyl group having 1 to 10 carbon atoms; cycloalkyl having 5 to 20 carbon atoms; group; an aryl group having 6 to 20 carbon atoms; or a heterocyclic group having 3 to 20 carbon atoms; in the above chemical formula (2b), R ₁₀ is an unsubstituted alkylene group having 1 to 10 carbon atoms; ₁₁ and R ₁₂ are each independently an alkyl group having 1 to 10 carbon atoms; a cycloalkyl group having 5 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; or a heterocyclic group having 3 to 20 carbon atoms; Good too.

Furthermore, more specifically, the compound represented by the above formula (2) can be a compound represented by the following formulas (2-1) to (2-3).

When the copolymer is modified with a modifier containing the compound represented by formula (2) above, the modifier containing the compound represented by formula (2) is used as a modification initiator.
Specifically, for example, by polymerizing a conjugated diene monomer and an aromatic vinyl monomer in a hydrocarbon solvent in the presence of a modifier containing a compound represented by formula (2), A modifying group derived from the compound represented by formula (2) can be added to the copolymer.

Here, the polymerization of the conjugated diene monomer and the aromatic vinyl monomer can be, for example, anionic polymerization, and as a specific example, an anion active site is formed at the polymerization end by a growth polymerization reaction using anions. Living anionic polymerization may also be used.
Further, the polymerization may be temperature-programmed polymerization, isothermal polymerization, or constant-temperature polymerization (adiabatic polymerization), and the constant-temperature polymerization may be performed optionally after adding a modifier containing the compound represented by formula (2) above. It refers to a polymerization method that includes a step of polymerizing with self-reaction heat without applying heat to the polymer, and the temperature-rising polymerization refers to a polymerization method in which the temperature is increased by optionally adding heat after adding a modification initiator. The isothermal polymerization refers to a polymerization method in which after the modification initiator is added, heat is applied to increase the heat or heat is removed to maintain a constant temperature of the polymer.

The content of the modified copolymer in the rubber component (A) is not particularly limited, but can be 0.1 to 90% by mass, preferably 10 to 90% by mass, and 20 to 80% by mass. It is more preferable that it is mass %. When the content of the modified copolymer is 0.1% by weight or more, low heat build-up can be improved while maintaining good other physical properties, and as a result, molded products manufactured using the rubber composition, such as , effects such as tire fuel efficiency, wear characteristics, and braking characteristics can be obtained more reliably.

(filler)
The rubber composition produced by the production method of the present invention contains a filler containing an inorganic filler (B).
Here, as the inorganic filler (B), for example, silica and an inorganic compound represented by the following general formula (XI) can be used.
dM ^1.xSiO _{y.zH 2} O...(XI)
Here, in the general formula (XI), M1 is a metal selected from the group consisting of aluminum, magnesium, titanium, calcium, and zirconium, an oxide or hydroxide of these metals, and a hydrate thereof, or At least one selected from carbonates of these metals, and d, x, y and z are each an integer of 1 to 5, an integer of 0 to 10, an integer of 2 to 5, and an integer of 0 to 10. .
In general formula (XI), when x and z are both 0, the inorganic compound is at least one metal, metal oxide, or metal hydroxide selected from aluminum, magnesium, titanium, calcium, and zirconium. becomes.

In the present invention, among the above-mentioned inorganic fillers (B), silica is preferred from the viewpoint of achieving both low rolling properties and wear resistance. Any commercially available silica can be used, and among these, wet silica, dry silica, and colloidal silica are preferably used, and wet silica is particularly preferred. The BET specific surface area (measured according to ISO 5794/1) of the silica is preferably 40 to 350 m ² /g. Silica having a BET surface area within this range has the advantage of being able to achieve both rubber reinforcing properties and dispersibility into the rubber component. From this viewpoint, silica with a BET surface area in the range of 80 to 350 m ² /g is more preferred, and silica with a BET surface area in the range of 120 to 350 m ² /g is particularly preferred. Examples of such silica include Tosoh Silica Co., Ltd. under the trade name "Nipsil AQ" (BET specific surface area = 220 m ² /g), "Nipsil KQ" and Degussa Corporation under the trade name "Ultrasil VN3" (BET specific surface area = 175 m ² /g) and the like can be used.

Examples of the inorganic compound represented by the general formula (XI) include alumina ( _Al 2 O ₃ ) such as γ-alumina and α-alumina, alumina monohydrate (Al ₂ O ₃ .H 2 O) such as boehmite and diaspore; Aluminum hydroxide [Al(OH) ₃ ], aluminum carbonate [Al ₂ (CO ₃ ) ₂ ], magnesium hydroxide [Mg(OH) ₂ ], magnesium oxide (MgO), magnesium carbonate (MgCO ₃ ), talc (3MgO・_4SiO2・_H2O ), attapulgite (5MgO・_8SiO2・_9H2O ), titanium white ( _TiO2 ), titanium black ( _TiO2n-1 ), calcium oxide (CaO), water Calcium oxide [Ca(OH) ₂ ], magnesium aluminum oxide (MgO・Al ₂ O ₃ ), clay (Al ₂ O ₃・2SiO ₂ ), kaolin (Al ₂ O ₃・2SiO ₂・2H ₂ O), pyrophyll _{Light ( Al2O3.4SiO2.H2O} ) _{, bentonite ( Al2O3.4SiO2.2H2O )} , aluminum silicate _{( Al2SiO5 , Al4.3SiO4.5H2O} , etc. ₎ , magnesium silicate ( _Mg2SiO4 , _{MgSiO3, etc.} ), calcium silicate (Ca2.SiO4, etc.), aluminum calcium silicate ( _{Al2O3.CaO.2SiO2 , etc.} ), magnesium calcium silicate (CaMgSiO2 _{, etc.} ) ₄ ), Calcium carbonate (CaCO ₃ ), Zirconium oxide (ZrO2), Zirconium hydroxide [ZrO(OH) ₂ ·nH ₂ O], Zirconium carbonate [Zr(CO ₃ ) ₂ ], Charge correction like various zeolites Crystalline aluminosilicates containing hydrogen, alkali metals, or alkaline earth metals can be used. Further, it is preferable that M1 in the general formula (XI) is at least one selected from aluminum metal, aluminum oxides or hydroxides, hydrates thereof, or aluminum carbonates.
These inorganic compounds represented by the general formula (XI) may be used alone or in combination of two or more. The average particle size of these inorganic compounds is preferably in the range of 0.01 to 10 μm, more preferably in the range of 0.05 to 5 μm, from the viewpoint of the balance between kneading workability, abrasion resistance, and wet grip performance. As the inorganic filler (B) in the present invention, silica may be used alone, or silica and one or more types of inorganic compounds represented by general formula (III) may be used in combination.

Moreover, the filler may contain carbon black in addition to the above-mentioned inorganic filler (B), if desired. By containing carbon black, the reinforcing properties of the rubber composition can be enhanced and better wear resistance can be obtained. This carbon black is not particularly limited, and includes, for example, high, medium or low structure SAF, ISAF, IISAF, N339, HAF, FEF, GPF, SRF grade carbon black, especially SAF, ISAF, IISAF, N339, HAF, Preferably, FEF grade carbon black is used. The nitrogen adsorption specific surface area (N2SA, measured according to JIS K6217-2:2001) is preferably 30 to 250 m ² /g. One type of carbon black may be used alone, or two or more types may be used in combination. Note that, in the present invention, carbon black is not included in the inorganic filler (B).

In the production method of the present invention, the inorganic filler (B) is preferably used in an amount of 20 to 120 parts by mass based on 100 parts by mass of the rubber component (A). If it is 20 parts by mass or more, it is preferable from the viewpoint of ensuring wet performance, and if it is 120 parts by mass or less, it is preferable from the viewpoint of improving low heat generation property. Furthermore, it is more preferable to use 30 to 100 parts by mass.
Further, the filler is preferably used in an amount of 20 to 150 parts by mass per 100 parts by mass of the rubber component (A). If it is 20 parts by mass or more, it is preferable from the viewpoint of improving the reinforcing property of the rubber composition, and if it is 150 parts by mass or less, it is preferable from the viewpoint of improving low heat generation property.
Further, in the filler, the content of the inorganic filler (B) is preferably 40% by mass or more from the viewpoint of achieving both wet performance and low heat build-up, and more preferably 70% by mass or more.

(Silane coupling agent)
The rubber composition produced by the production method of the present invention contains a silane coupling agent (C).
Here, the silane coupling agent (C) is preferably at least one compound selected from the group consisting of compounds represented by the following general formulas (I) to (IV).
By using such a silane coupling agent (C), the rubber composition produced by the production method of the present invention has better workability during rubber processing, and can also be used in pneumatic tires with better wear resistance. can be given.

In the formula, R ¹ may be the same or different, and each represents a straight chain, cyclic or branched alkyl group having 1 to 8 carbon atoms, or a straight chain or branched alkoxyalkyl group having 2 to 8 carbon atoms, R ² may be the same or different, each a straight chain, cyclic or branched alkyl group having 1 to 8 carbon atoms, and R ³ may be the same or different, each being a straight chain or branched chain having 1 to 8 carbon atoms. In the alkylene group, a has an average value of 2 to 6, p and r may be the same or different, and each has an average value of 0 to 3, provided that both p and r are not 3.

Specific examples of the silane coupling agent (C) represented by the above general formula (I) include bis(3-triethoxysilylpropyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(3-methyl dimethoxysilylpropyl) tetrasulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(3-triethoxysilylpropyl)disulfide, bis(3-trimethoxysilylpropyl)disulfide, bis(3-methyldimethoxysilylpropyl) Disulfide, bis(2-triethoxysilylethyl) disulfide, bis(3-triethoxysilylpropyl) trisulfide, bis(3-trimethoxysilylpropyl) trisulfide, bis(3-methyldimethoxysilylpropyl) trisulfide, bis (2-Triethoxysilylethyl)trisulfide, bis(3-monoethoxydimethylsilylpropyl)tetrasulfide, bis(3-monoethoxydimethylsilylpropyl)trisulfide, bis(3-monoethoxydimethylsilylpropyl)disulfide, (3-monomethoxydimethylsilylpropyl)tetrasulfide, bis(3-monomethoxydimethylsilylpropyl)trisulfide, bis(3-monomethoxydimethylsilylpropyl)disulfide, bis(2-monoethoxydimethylsilylethyl)tetrasulfide, Bis(2-monoethoxydimethylsilylethyl) trisulfide, bis(2-monoethoxydimethylsilylethyl) disulfide and the like can be mentioned.

In the formula, R ⁴ is -Cl, -Br, R ⁹ O-, R ⁹ C(=O)O-, R ⁹ R ¹⁰ C=NO-, R ⁹ R ¹⁰ CNO-, R ⁹ R ¹⁰ N-, and -(OSiR ⁹ R ¹⁰ ) _h (OSiR ⁹ R ¹⁰ R ¹¹ ) (R ⁹ , R ¹⁰ and R ¹¹ are each a hydrogen atom or a monovalent hydrocarbon having 1 to 18 carbon atoms) h is an average value of 1 to 4), R ⁵ is R ⁴ , a hydrogen atom or a monovalent hydrocarbon group having 1 to 18 carbon atoms, and R ⁶ is R ⁴ , R ⁵ is a hydrogen atom or a -[O(R ¹² O) _j ]0.5- group (R ¹² is an alkylene group having 1 to 18 carbon atoms, and j is an integer of 1 to 4), and R ⁷ is It is a divalent hydrocarbon group having 1 to 18 carbon atoms, and R ⁸ is a monovalent hydrocarbon group having 1 to 18 carbon atoms. x, y, and z are numbers that satisfy the following relationships: x+y+2z=3, 0≦x≦3, 0≦y≦2, and 0≦z≦1.

In the above general formula (II), R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ may be the same or different, and each is preferably a linear, cyclic or branched alkyl group or alkenyl group having 1 to 18 carbon atoms. , an aryl group, and an aralkyl group. Further, when R5 is a monovalent hydrocarbon group having 1 to 18 carbon atoms, it is a group selected from the group consisting of a linear, cyclic or branched alkyl group, alkenyl group, aryl group and aralkyl group. It is preferable. R ¹² is preferably a linear, cyclic or branched alkylene group, and particularly preferably a linear one. R ⁹ is, for example, an alkylene group having 1 to 18 carbon atoms, an alkenylene group having 2 to 18 carbon atoms, a cycloalkylene group having 5 to 18 carbon atoms, a cycloalkylalkylene group having 6 to 18 carbon atoms, or an arylene group having 6 to 18 carbon atoms. and an aralkylene group having 7 to 18 carbon atoms. The alkylene group and alkenylene group may be linear or branched, and the cycloalkylene group, cycloalkylalkylene group, arylene group, and aralkylene group may have a substituent such as a lower alkyl group on the ring. may have. R ⁷ is preferably an alkylene group having 1 to 6 carbon atoms, and particularly preferably linear alkylene groups such as methylene, ethylene, trimethylene, tetramethylene, pentamethylene, and hexamethylene groups. can.

Specific examples of the monovalent hydrocarbon group having 1 to 18 carbon atoms as R ⁵ , R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ in the above general formula (II) include a methyl group, an ethyl group, and an n-propyl group. , isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, decyl group, dodecyl group, cyclopentyl group, cyclohexyl group, vinyl group, propenyl group , allyl group, hexenyl group, octenyl group, cyclopentenyl group, cyclohexenyl group, phenyl group, tolyl group, xylyl group, naphthyl group, benzyl group, phenethyl group, naphthylmethyl group and the like.
Examples of R ¹² in the above general formula (II) include methylene group, ethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, octamethylene group, decamethylene group, dodecamethylene group, and the like.

Specific examples of the silane coupling agent (C) represented by the general formula (II) include 3-hexanoylthiopropyltriethoxysilane, 3-octanoylthiopropyltriethoxysilane, and 3-decanoylthiopropyltriethoxysilane. Ethoxysilane, 3-lauroylthiopropyltriethoxysilane, 2-hexanoylthioethyltriethoxysilane, 2-octanoylthioethyltriethoxysilane, 2-decanoylthioethyltriethoxysilane, 2-lauroylthioethyltriethoxysilane , 3-hexanoylthiopropyltrimethoxysilane, 3-octanoylthiopropyltrimethoxysilane, 3-decanoylthiopropyltrimethoxysilane, 3-lauroylthiopropyltrimethoxysilane, 2-hexanoylthioethyltrimethoxysilane, Examples include 2-octanoylthioethyltrimethoxysilane, 2-decanoylthioethyltrimethoxysilane, and 2-lauroylthioethyltrimethoxysilane. Among these, 3-octanoylthiopropyltriethoxysilane (manufactured by General Electric Silicones, trademark: NXT silane) is particularly preferred.

In the formula, when there is a plurality of R ^13s , they may be the same or different, and each R 13 is a straight chain, cyclic or branched alkyl group having 1 to 8 carbon atoms, or a straight chain or branched alkoxy group having 2 to 8 carbon atoms. It is an alkyl group or a hydrogen atom, and when there is a plurality of R ^14s , they may be the same or different, and each is a linear, cyclic, or branched alkyl group having 1 to 8 carbon atoms, and when there is a plurality of R ^15s , they are linear, cyclic, or branched alkyl groups. may be the same or different, and each is a straight chain or branched alkylene group having 1 to 8 carbon atoms. R ¹⁶ is any of the general formulas (-S-R ¹⁷ -S-), (-R ¹⁸ -S _m1 -R ¹⁹ -) and (-R ²⁰ -S _m2 -R ²¹ -S _m3 -R ²² -) (R ¹⁷ to R ²² are each a divalent hydrocarbon group having 1 to 20 carbon atoms, a divalent aromatic group, or a divalent organic group containing a hetero element other than sulfur and oxygen) , m1, m2, and m3 each have an average value of 1 or more and less than 4.), the plurality of k's may be the same or different, each has an average value of 1 to 6, and s and t each have an average value of The value is 0 to 3. However, both s and t cannot be 3.

As a specific example of the silane coupling agent (C) represented by the above general formula (III),
Average composition formula (CH ₃ CH ₂ O) 3 Si-(CH ₂ ) ₃ -S ₂ -(CH ₂ )6-S ₂ -(CH ₂ ) ₃ -
Si(OCH ₂ CH ₃ ) ₃ ,
Average composition formula (CH ₃ CH ₂ O) ₃ Si-(CH ₂ ) ₃ -S ₂ -(CH ₂ ) ₁₀ -S ₂ -(CH ₂ ) ₃ -
Si(OCH ₂ CH ₃ ) ₃ ,
Average composition formula (CH ₃ CH ₂ O) ₃ Si-(CH ₂ ) ₃ -S ₃ -(CH ₂ ) ₆ -S ₃ -(CH ₂ ) ₃ -
Si(OCH ₂ CH ₃ ) ₃ ,
Average composition formula (CH ₃ CH ₂ O) ₃ Si-(CH ₂ ) ₃ -S ₄ -(CH ₂ ) ₆ -S ₄ -(CH ₂ ) ₃ -
Si(OCH ₂ CH ₃ ) ₃ ,
Average composition formula (CH ₃ CH ₂ O) ₃ Si-(CH ₂ ) ₃ -S-(CH ₂ ) ₆ -S ₂ -(CH ₂ ) ₆ -S
-(CH ₂ ) ₃ -Si(OCH ₂ CH ₃ ) ₃ ,
Average composition formula (CH ₃ CH ₂ O) ₃ Si-(CH ₂ ) ₃ -S-(CH ₂ ) ₆ -S _2.5 -(CH ₂ ) ₆ -
S-(CH ₂ ) ₃ -Si(OCH ₂ CH ₃ ) ₃ ,
Average composition formula (CH ₃ CH ₂ O) ₃ Si-(CH ₂ ) ₃ -S-(CH ₂ ) ₆ -S ₃ -(CH ₂ ) ₆ -S
-(CH ₂ ) ₃ -Si(OCH ₂ CH ₃ ) ₃ ,
Average composition formula (CH ₃ CH ₂ O) ₃ Si-(CH ₂ ) ₃ -S-(CH ₂ ) ₆ -S _4- (CH ₂ ) ₆ -S
-(CH ₂ ) ₃ -Si(OCH ₂ CH ₃ ) ₃ ,
Average composition formula (CH ₃ CH 2 O) ₃ Si-(CH ₂ ) ₃ -S-(CH ₂ ) ₁₀ -S ₂ -(CH ₂ ) ₁₀ -
S-(CH ₂ ) ₃ -Si(OCH ₂ CH ₃ ) ₃ ,
Average composition formula (CH ₃ CH ₂ O) ₃ Si-(CH ₂ ) ₃ -S ₄ -(CH ₂ ) ₆ -S _4- (CH ₂ ) ₆ -
S ₄ -(CH ₂ ) ₃ -Si(OCH ₂ CH ₃ ) ₃ ,
Average composition formula (CH ₃ CH ₂ O) ₃ Si-(CH ₂ ) ₃ -S ₂ -(CH ₂ ) ₆ -S ₂ -(CH ₂ ) ₆ -
S ₂ -(CH ₂ ) ₃ -Si(OCH ₂ CH ₃ ) ₃ ,
Average composition formula (CH ₃ CH ₂ O) ₃ Si-(CH ₂ ) ₃ -S-(CH ₂ ) ₆ -S ₂ -(CH ₂ ) ₆ -S
Preferred examples include compounds represented by ₂ -(CH ₂ ) ₆ -S-(CH ₂ ) ₃ -Si(OCH ₂ CH ₃ ) ₃ and the like.

In the formula, R ²³ is a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, and multiple G's may be the same or different, and each is an alkanediyl group or an alkenediyl group having 1 to 9 carbon atoms. and the plurality of Z ^a may be the same or different, each being a functional group capable of bonding with two silicon atoms, and [-0-] _0.5 , [-0-G-] _{0. 5} and [-O-G-O-] _0.5 , and the plurality of Z ^b 's may be the same or different, and each is a functional group that can bond to two silicon atoms. , and is a functional group represented by [-O-G-O-] _0.5 , and the plurality of Z ^c may be the same or different, and each of them is -Cl, -Br, -OR ^a , R ^a C A functional group selected from (=O)O-, R ^a R ^b C=NO-, R ^a R ^b N-, R ^a -, and HO-G-O- (G matches the above notation). , R ^b and R ^b are each a straight chain, branched or cyclic alkyl group having 1 to 20 carbon atoms. m, n, u, v and w are 1≦m≦20, 0≦n≦20, 0≦u≦3, 0≦v≦2, 0≦w≦1, and (u/2)+v+2w =2 or 3. When there are multiple A parts, Z ^a _u , Z ^b _v and Z ^c _w in the multiple A parts may be the same or different, and when there are multiple B parts, Z ^a in the multiple B parts _u , Z ^b _v and Z ^c _w may be the same or different.

Specific examples of the silane coupling agent (C) represented by the general formula (IV) include chemical formula (V), chemical formula (IV), and chemical formula (VII).
In the formula, each L is independently an alkanediyl group or an alkenediyl group having 1 to 9 carbon atoms, and x=m and y=n.

As the silane coupling agent represented by the chemical formula (V), "NXT Low-VSilane" manufactured by Momentive Performance Materials is available as a commercial product.
Further, as the silane coupling agent represented by the chemical formula (VI), the trademark "NXT Ultra Low-VSilane" manufactured by Momentive Performance Materials is also available as a commercial product.
Further, as the silane coupling agent represented by the chemical formula (VII), it can be mentioned as "NXT-Z", a trademark manufactured by Momentive Performance Materials.
The silane coupling agents obtained by the above general formula (II), chemical formula (V), and chemical formula (VI) have a protected mercapto group, so during initial vulcanization (scorch) during processing before the vulcanization step. ) can be prevented from occurring, resulting in improved workability.
Moreover, since the silane coupling agents obtained by chemical formulas (V), (VI), and (VII) have a large number of alkoxysilane carbon atoms, they generate less volatile compounds VOC (especially alcohol), which is preferable in terms of the working environment. Moreover, the silane coupling agent of chemical formula (VII) is more preferable because it provides low heat build-up as a tire performance.

Furthermore, the silane coupling agent (C) is particularly preferably a compound represented by the above general formula (I) among the compounds represented by the above general formulas (I) to (IV). This is because the vulcanization accelerator (D) tends to activate the polysulfide bonding site that reacts with the rubber component (A).
In the present invention, the silane coupling agent (C) may be used alone or in combination of two or more.
Furthermore, the amount of the silane coupling agent (C) in the rubber composition is such that the mass ratio {silane coupling agent (C)/inorganic filler (B)} is between (1/100) and (20/100). It is preferable that If it is (1/100) or more, the effect of improving the low heat generation property of the rubber composition will be more suitably exhibited, and if it is (20/100) or less, the cost of the rubber composition will be reduced and it will be economical. This is because it improves. Furthermore, the mass ratio is more preferably (3/100) to (20/100), and particularly preferably the mass ratio is (4/100) to (10/100).

(vulcanization accelerator)
The rubber composition produced by the production method of the present invention contains a vulcanization accelerator (D).
As the vulcanization accelerator (D), preferred vulcanization accelerators such as guanidines, sulfenamides, thiazoles, thiurams, dithiocarbamates, thioureas, and xanthates will be described in detail.

Examples of the vulcanization accelerator for guanidines include 1,3-diphenylguanidine, 1,3-di-o-tolylguanidine, 1-o-tolyl biguanide, di-o-tolylguanidine salt of dicatechol borate, 1, Examples include 3-di-o-cumenylguanidine, 1,3-di-o-biphenylguanidine, 1,3-di-o-cumenyl-2-propionylguanidine, and 1,3-diphenylguanidine, 1,3 -di-o-tolylguanidine and 1-o-tolyl biguanide are preferred because of their high reactivity.

As the vulcanization accelerator for the sulfenamides, N-cyclohexyl-2-benzothiazolylsulfenamide, N,N-dicyclohexyl-2-benzothiazolylsulfenamide, N-tert-butyl-2-benzo Thiazolylsulfenamide, N-oxydiethylene-2-benzothiazolylsulfenamide, N-methyl-2-benzothiazolylsulfenamide, N-ethyl-2-benzothiazolylsulfenamide, N-propyl- 2-Benzothiazolylsulfenamide, N-butyl-2-benzothiazolylsulfenamide, N-pentyl-2-benzothiazolylsulfenamide, N-hexyl-2-benzothiazolylsulfenamide, N- Pentyl-2-benzothiazolyl sulfenamide, N-octyl-2-benzothiazolyl sulfenamide, N-2-ethylhexyl-2-benzothiazolyl sulfenamide, N-decyl-2-benzothiazolyl sulfenamide Amide, N-dodecyl-2-benzothiazolylsulfenamide, N-stearyl-2-benzothiazolylsulfenamide, N,N-dimethyl-2-benzothiazolylsulfenamide, N,N-diethyl-2 -Benzothiazolylsulfenamide, N,N-dipropyl-2-benzothiazolylsulfenamide, N,N-dibutyl-2-benzothiazolylsulfenamide, N,N-dipentyl-2-benzothiazolylsulfenamide Phenamide, N,N-dihexyl-2-benzothiazolylsulfenamide, N,N-dipentyl-2-benzothiazolylsulfenamide, N,N-dioctyl-2-benzothiazolylsulfenamide, N, N-di-2-ethylhexylbenzothiazolylsulfenamide, N-decyl-2-benzothiazolylsulfenamide, N,N-didodecyl-2-benzothiazolylsulfenamide, N,N-distearyl-2 -Benzothiazolylsulfenamide and the like. Among these, N-cyclohexyl-2-benzothiazolylsulfenamide and N-tert-butyl-2-benzothiazolylsulfenamide are preferred because of their high reactivity.

The vulcanization accelerators for the thiazoles include 2-mercaptobenzothiazole, di-2-benzothiazolyl disulfide, zinc salt of 2-mercaptobenzothiazole, cyclohexylamine salt of 2-mercaptobenzothiazole, and 2-(N , N-diethylthiocarbamoylthio)benzothiazole, 2-(4'-morpholinodithio)benzothiazole, 4-methyl-2-mercaptobenzothiazole, di-(4-methyl-2-benzothiazolyl) disulfide, 5-chloro- 2-mercaptobenzothiazole, 2-mercaptobenzothiazole sodium, 2-mercapto-6-nitrobenzothiazole, 2-mercapto-naphtho[1,2-d]thiazole, 2-mercapto-5-methoxybenzothiazole, 6-amino -2-mercaptobenzothiazole and the like. Among these, 2-mercaptobenzothiazole and di-2-benzothiazolyl disulfide are preferred because of their high reactivity.

Examples of the thiuram vulcanization accelerator include tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrapropylthiuram disulfide, tetraisopropylthiuram disulfide, tetrabutylthiuram disulfide, tetrapentylthiuram disulfide, tetrahexylthiuram disulfide, tetraheptylthiuram disulfide, Tetra Okuchilchillamazulfide, Tetrannil Churamazulfide, Tetra Decyl Churamazulfide, Tetradodecyl Churamu Jisulfide, Tetras Tearyl Churchuramjisulfide, Tetravenzirchuramju Ramjisulfide, Tetrakis (2 -Ethilhexyl) Churamjisl Fid, Tetra Methylchiulam Monosulfide, Tetracular Churam Monosulfide, Tetrapropylthiuram monosulfide, tetraisopropylthiuram monosulfide, tetrabutylthiuram monosulfide, tetrapentylthiuram monosulfide, tetrahexylthiuram monosulfide, tetraheptylthiuram monosulfide, tetraoctylthiuram monosulfide, tetranonylthiuram monosulfide, tetradecyl Examples include thiuram monosulfide, tetradodecylthiuram monosulfide, tetrastearylthiuram monosulfide, tetrabenzylthiuram monosulfide, dipentamethylenethiuram tetrasulfide, and the like. Among these, tetrakis(2-ethylhexyl)thiuram disulfide and tetrabenzylthiuram disulfide are preferred because of their high reactivity.

Examples of the vulcanization accelerator for the thioureas include N,N'-diphenylthiourea, trimethylthiourea, N,N'-diethylthiourea, N,N'-dimethylthiourea, N,N'-dibutylthiourea, and ethylenethiourea. , N,N'-diisopropylthiourea, N,N'-dicyclohexylthiourea, 1,3-di(o-tolyl)thiourea, 1,3-di(p-tolyl)thiourea, 1,1-diphenyl -2-thiourea, 2,5-dithiobiurea, guanylthiourea, 1-(1-naphthyl)-2-thiourea, 1-phenyl-2-thiourea, p-tolylthiourea, o-tolylthiourea, etc. It will be done. Among these, N,N'-diethylthiourea, trimethylthiourea, N,N'-diphenylthiourea and N,N'-dimethylthiourea are preferred because of their high reactivity.

Examples of the vulcanization accelerator for the dithiocarbamates include zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc dipropyldithiocarbamate, zinc diisopropyldithiocarbamate, zinc dibutyldithiocarbamate, zinc dipentyldithiocarbamate, zinc dihexyldithiocarbamate, and diheptyl. Zinc dithiocarbamate, zinc dioctyldithiocarbamate, zinc di(2-ethylhexyl)dithiocarbamate, zinc didecyldithiocarbamate, zinc didodecyldithiocarbamate, zinc N-pentamethylenedithiocarbamate, zinc N-ethyl-N-phenyldithiocarbamate, Zinc dibenzyldithiocarbamate, copper dimethyldithiocarbamate, copper diethyldithiocarbamate, copper dipropyldithiocarbamate, copper diisopropyldithiocarbamate, copper dibutyldithiocarbamate, copper dipentyldithiocarbamate, copper dihexyldithiocarbamate, copper diheptyldithiocarbamate, dioctyldithiocarbamine copper acid, copper di(2-ethylhexyl) dithiocarbamate, copper didecyl dithiocarbamate, copper didodecyl dithiocarbamate, copper N-pentamethylene dithiocarbamate, copper dibenzyldithiocarbamate, sodium dimethyldithiocarbamate, sodium diethyldithiocarbamate, Sodium propyldithiocarbamate, sodium diisopropyldithiocarbamate, sodium dibutyldithiocarbamate, sodium dipentyldithiocarbamate, sodium dihexyldithiocarbamate, sodium diheptyldithiocarbamate, sodium dioctyldithiocarbamate, sodium di(2-ethylhexyl)dithiocarbamate, didecyldithiocarbamic acid Sodium, sodium didodecyldithiocarbamate, sodium N-pentamethylenedithiocarbamate, sodium dibenzyldithiocarbamate, ferric dimethyldithiocarbamate, ferric diethyldithiocarbamate, ferric dipropyldithiocarbamate, ferric diisopropyldithiocarbamate , ferric dibutyldithiocarbamate, ferric dipentyldithiocarbamate, ferric dihexyldithiocarbamate, ferric diheptyldithiocarbamate, ferric dioctyldithiocarbamate, ferric di(2-ethylhexyl)dithiocarbamate, Examples include ferric decyldithiocarbamate, ferric didodecyldithiocarbamate, ferric N-pentamethylenedithiocarbamate, and ferric dibenzyldithiocarbamate. Among these, zinc dibenzyldithiocarbamate, zinc N-ethyl-N-phenyldithiocarbamate, zinc dimethyldithiocarbamate and copper dimethyldithiocarbamate are preferred because of their high reactivity.

Examples of the vulcanization accelerator for the xanthate salts include zinc methylxanthate, zinc ethylxanthate, zinc propylxanthate, zinc isopropylxanthate, zinc butylxanthate, zinc pentylxanthate, zinc hexylxanthate, and zinc heptylxanthate. Zinc, zinc octylxanthate, zinc 2-ethylhexylxanthate, zinc decylxanthate, zinc dodecylxanthate, potassium methylxanthate, potassium ethylxanthate, potassium propylxanthate, potassium isopropylxanthate, potassium butylxanthate, pentyl Potassium xanthate, potassium hexylxanthate, potassium heptylxanthate, potassium octylxanthate, potassium 2-ethylhexylxanthate, potassium decylxanthate, potassium dodecylxanthate, sodium methylxanthate, sodium ethylxanthate, sodium propylxanthate , sodium isopropylxanthate, sodium butylxanthate, sodium pentylxanthate, sodium hexylxanthate, sodium heptylxanthate, sodium octylxanthate, sodium 2-ethylhexylxanthate, sodium decylxanthate, sodium dodecylxanthate, etc. It will be done. Among these, zinc isopropylxanthate is preferred because of its high reactivity.

In the production method of the present invention, it is preferable to use at least one guanidine vulcanization accelerator or at least one thiourea vulcanization accelerator among the various vulcanization accelerators mentioned above. It is more preferable to use at least one type of guanidine vulcanization accelerator.
When the modified copolymer in the rubber component (A) is modified at both ends, the blended viscosity tends to increase, but by using the guanidine vulcanization accelerator, the blended viscosity can be increased. This is because the increase can be suppressed and better workability can be obtained.

In addition, in the manufacturing method of the present invention, the number of molecules (number of moles) of the vulcanization accelerator (D) in the rubber composition in the first stage of kneading is the number of molecules (number of moles) of the silane coupling agent (C). It is preferably 0.1 to 1.0 times that of This is because if it is 0.1 times or more, activation of the silane coupling agent (C) will occur sufficiently, and if it is 1.0 times or less, the vulcanization rate will not be greatly affected. More preferably, the number of molecules (number of moles) of the vulcanization accelerator (D) is 0.2 to 0.6 times the number of molecules (number of moles) of the silane coupling agent (C).
In addition, since the vulcanization accelerator (D) is also used as an accelerator for sulfur vulcanization, it may be added in an appropriate amount even in the final stage of kneading, if desired. When blending a vulcanization accelerator in the final stage of kneading, it is not limited to the above-mentioned vulcanization accelerator (D), and any known vulcanization accelerator can also be blended.

(Organic acid compound)
In the production method of the present invention, the number of molecules (number of moles) of the organic acid compound in the rubber composition in the first stage of kneading is 1.5 times the number of molecules (number of moles) of the vulcanization accelerator (D). It is preferable that it is below. This is to suitably suppress the reduction in the effect of improving the activity of the coupling function due to the addition of the vulcanization accelerator (D).

The organic acid compounds include stearic acid, palmitic acid, myristic acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, capric acid, pelargonic acid, caprylic acid, enanthic acid, caproic acid, oleic acid, vaccenic acid, and linoleic acid. Examples include organic acids such as acids, saturated fatty acids and unsaturated fatty acids such as linolenic acid and nervonic acid, resin acids such as rosin acid and modified rosin acid, and esters of the above-mentioned saturated fatty acids, the above-mentioned unsaturated fatty acids, and resin acids.
In addition, in the present invention, stearic acid accounts for 50 mol% or more of the organic acid compound contained in the rubber composition in the first stage of kneading, since it can also fully exhibit its function as a vulcanization accelerator. It is preferable that there be.
In addition, when the rubber component (A) contains at least one selected from emulsion polymerized styrene-butadiene copolymer and natural rubber, 50 mol of the organic acid compound contained in the rubber composition in the first stage of kneading. % or more is preferably at least one compound selected from rosin acid and fatty acid contained in at least one selected from the emulsion polymerized styrene-butadiene copolymer and the natural rubber. The rosin acid (including modified rosin acid) and fatty acid contained in the emulsion polymerized styrene-butadiene copolymer are derived from the emulsifier necessary for polymerizing the emulsion polymerized styrene-butadiene copolymer. Natural rubber also usually contains small amounts of fatty acids.

(Other ingredients)
The rubber composition produced by the production method of the present invention contains the above-mentioned rubber component (A), a filler containing an inorganic filler (B), a silane coupling agent (C), and a vulcanization accelerator (D). ), etc., compounding components commonly used in the rubber industry, such as anti-aging agents, softeners, etc., are appropriately selected within the range that does not impair the purpose of the present invention, and within the range of normal compounding amounts. It can be blended with Commercially available products can be suitably used as these compounding agents.

As the anti-aging agent, any known anti-aging agent can be used and is not particularly limited. For example, phenol-based anti-aging agents, imidazole-based anti-aging agents, amine-based anti-aging agents, etc. can be mentioned. These anti-aging agents can be used alone or in combination of two or more.

Furthermore, the rubber composition produced by the production method of the present invention preferably further contains a softener from the viewpoint of achieving excellent low loss properties and abrasion resistance. Examples of the softening agent include naphthenic base oils, paraffinic base oils, aromatic base oils, and the like. Here, the content of the lubricant is preferably 2 to 30 parts by mass based on 100 parts by mass of the rubber component. If the content of the lubricant exceeds 30 parts by mass based on 100 parts by mass of the rubber component, there is a risk that the lubricant will ooze out onto the surface of the rubber product or that the wear resistance may decrease. In addition, since it interacts with and shields the tetrazine moiety in the modified rubber component, the reactivity decreases, and there is also a risk that low-loss performance and abrasion resistance decrease.
Furthermore, among the above-mentioned lubricants, it is preferable to use a naphthenic base oil or a paraffinic base oil, and it is most preferable to use a naphthenic base oil. This is because aroma oil has a high affinity with the drug, which is an aromatic compound, because it has a large amount of aromatic components, and this is undesirable because it further inhibits the reaction with the polymer. On the other hand, naphthenic base oils and paraffinic base oils have the effect of helping to diffuse into polymers and react, and this is because oils with lower pour points diffuse better into polymers.
The classification of the naphthenic base oil, the paraffinic base oil, and the aromatic base oil is determined by the CA value, CP value, and CN value. For example, the naphthenic base oils are classified as TDAE, SRAE, RAE, Black Oil, and the like. Further, spindle oil and paraffin oil are classified as the paraffin base oil.
Furthermore, more preferable effects can be obtained with a mixed oil such as A/O Mix (Sankyo Yuka Kogyo Co., Ltd.), which is a mixture of the naphthenic base oil and the naphthenic asphalt.
The timing of blending these lubricating oils is not particularly limited, and for example, the oil may be extended during the production of the rubber component, or may be added when kneading the rubber composition.

In addition, in the method for producing the rubber composition of the present invention, various compounding agents such as a vulcanization activator such as zinc white and an anti-aging agent, which are usually blended into the rubber composition, are added to the rubber composition as needed in the first stage of kneading. It is kneaded in the stage or the final stage, or in an intermediate stage between the first stage and the final stage.
As a kneading device in the production method of the present invention, a Banbury mixer, a roll, an intensive mixer, a kneader, a twin-screw extruder, etc. are used.

<Rubber composition>
The rubber composition of the present invention is characterized in that it is obtained by the method for manufacturing the rubber composition of the present invention described above.
The rubber composition obtained by the production method of the present invention has high filler dispersibility and excellent low loss properties.

<Tires>
The tire of the present invention is characterized by using the rubber composition of the present invention described above. By including the rubber composition of the present invention as a tire material, it is possible to reduce rolling resistance.
The tire of the present invention is not particularly limited other than using the rubber composition of the present invention described above for any of the tire members, and can be manufactured according to a conventional method. Note that as the gas to be filled in the tire, in addition to normal air or air with adjusted oxygen partial pressure, inert gas such as nitrogen, argon, helium, etc. can be used.

Further, in the tire of the present invention, the rubber composition of the present invention described above is used in any of the tire members, and among the tire members, tread rubber, sidewall rubber, cord or fiber coated rubber, bead filler, or gum chafer is used. It is preferably used for. This is because, if applied to these members, the rubber composition of the present invention can fully enjoy the excellent low loss effect and further benefit from the rolling resistance reducing effect.

The type of tire of the present invention is not particularly limited, but passenger car tires, studless tires, and run-flat tires are preferred from the standpoint of being able to more effectively achieve both improved wear resistance and reduced rolling resistance. Alternatively, it is preferably a tire for a truck or bus.

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to the Examples below.

(Samples 1 to 12)
Rubber composition samples were prepared using the formulation and kneading method shown in Table 1. Table 1 shows the maximum temperature of the mixture in the first kneading stage. In preparing a sample of the rubber composition, a second kneading step is performed after the first kneading step. Note that kneading is carried out using a Banbury mixer.

<Performance evaluation>
(1) Compound viscosity For the rubber composition of each sample, after preheating for 1 minute at 130°C using RPA2000 (manufactured by Alpha Technologies), the compound viscosity after 0.1 minutes was measured at a frequency of 1 Hz and a strain of 100%. Measure. The smaller the value, the better the workability.
Table 1 shows the measurement results of each Example and each Comparative Example. The smaller the measured value, the higher the dispersibility of silica, indicating better results.

(2) Low loss properties The rubber composition of each sample is vulcanized at 160°C for 15 minutes to obtain vulcanized rubber. The loss tangent (tan δ) of the obtained vulcanized rubber is measured using ARES-G2 (manufactured by TA Instruments) at a temperature of 30°C, a strain of 5%, and a frequency of 15Hz.
The measurement results of each Example and each Comparative Example are shown in Table 1 as an index that is a relative evaluation with the measurement result of Comparative Example 1 set as 100. The larger the index value, the lower the heat generation.

*1 SBR-1 is produced under the following conditions.
A cyclohexane solution of 1,3-butadiene and a cyclohexane solution of styrene were added to a 800 ml pressure-resistant glass container that had been dried and purged with nitrogen so that the total amount was 67.5 g of 1,3-butadiene and 7.5 g of styrene. - After adding 0.6 mmol of ditetrahydrofurylpropane and 0.8 mmol of n-butyllithium, polymerization is carried out at 50° C. for 1.5 hours. At this time, 0.72 mmol of [N,N-bis(trimethylsilyl)-(3-amino-1-propyl)](methyl)(diethoxy)silane was added to the polymerization reaction system where the polymerization conversion rate was almost 100%. Then, perform the denaturation reaction at 50°C for 30 minutes. Thereafter, 2 ml of a 5% by mass solution of 2,6-di-t-butyl-p-cresol (BHT) in isopropanol is added to stop the reaction, and the mixture is dried according to a conventional method to obtain modified SBR-1.
In addition, as a result of measuring the microstructure of the obtained modified SBR-1, the bound styrene content was 10% by mass, the vinyl content of the butadiene moiety was 40%, and the polystyrene equivalent peak molecular weight obtained by gel permeation chromatography was 200,000. be.
*2 SBR-2 is manufactured under the following conditions.
(Production example of modifier)
Prepare two vacuum-dried 4L stainless steel pressure vessels. A first reaction solution is prepared by charging 944 g of cyclohexane, 161 g of a compound represented by the following chemical formula (2-1), and 86 g of tetramethylethylenediamine into a first pressure vessel. At the same time, 318 g of liquid 20% by weight n-butyllithium and 874 g of cyclohexane were charged into the second pressure vessel to prepare a second reaction solution. At this time, the molar ratio of the compound represented by the following chemical formula (2-1), n-butyllithium, and tetramethylethylenediamine was 1:1:1. With the pressure in each pressure vessel maintained at 7 bar, the first reaction solution was injected into the first continuous channel into the continuous reactor using a mass flow meter at a rate of 1.0 g/min into the second continuous channel. The second reaction solution is injected into each channel at an injection rate of 1.0 g/min. At this time, the temperature of the continuous reactor was maintained at -10℃, the internal pressure was maintained at 3 bar using a backpressure regulator, and the residence time in the reactor was adjusted to within 10 minutes. do. The reaction is completed to obtain a modified initiator.
(Preparation of modified SBR-2)
A styrene solution containing 60% by weight of styrene dissolved in n-hexane was added to the first reactor of a continuous reactor in which three reactors were connected in series at a rate of 0.84 kg/h at a rate of 1,3% in n-hexane. - 1,3-butadiene solution with 60% by weight of butadiene dissolved at 15.10kg/h, n-hexane 47.66kg/h, 1,2-butadiene with 2.0% by weight of 1,2-butadiene dissolved in n-hexane 10 g/h of the solution, 10.0 g/h of a solution of 10% by weight of 2,2-(di-2(tetrahydrofuryl)propane dissolved in n-hexane as a polar additive), and the start of modification produced in the above production example. Agent (2-1) is injected at a rate of 292.5.0 g/h. At this time, the temperature of the first group reactor is maintained at 50°C, and when the polymerization conversion rate reaches 43%, the transfer The polymer is transferred from the first reactor to the second reactor through piping.
Subsequently, a 1,3-butadiene solution in which 60% by weight of 1,3-butadiene was dissolved in n-hexane was injected into the second reactor at a rate of 0.68 kg/h. At this time, the temperature of the second group reactor is maintained at 65℃, and when the polymerization conversion rate is 95% or more, the polymer is transferred from the second reactor to the third reactor through the transfer pipe. do.
The polymer is transferred from the second reactor to the third reactor, and a solution containing the following formula (1a) as a modifier is charged into the third reactor (modifier: act. Li=1:1 mol). The temperature of the third reactor is maintained at 65°C.
Thereafter, a solution of IR1520 (BASF) dissolved at 30% by weight as an antioxidant is injected into the polymerization solution discharged from the third reactor at a rate of 170 g/h and stirred. As a result, the obtained polymer is poured into warm water heated with steam, stirred, and the solvent is removed to obtain modified SBR-2.
Furthermore, as a result of measuring the microstructure of the obtained modified SBR-2, the styrene content was 5% by mass, and the vinyl content in the butadiene moiety was 37%.
*3 SBR-3 is manufactured under the following conditions.
Charge 2.750 g of cyclohexane, 2.00 g of tetrahydrofuran, 160 g of styrene, 165 g of 1,3-butadiene, and 34.9 mg (0.10 mmol) of potassium dodecylbenzenesulfonate (DBS-K) into a 5-liter autoclave reactor purged with nitrogen. . After adjusting the temperature of the reactor contents to 40°C, 215 mg (3.36 mmol) of n-butyllithium is added to initiate polymerization. When the polymerization temperature reaches 55° C., 165 g of 1,3-butadiene is added over 20 minutes. When the polymerization conversion rate reached 99%, 10 g of butadiene was added, and after polymerizing for another 5 minutes, 545 mg (2.9 mmol) of 1-trimethylsilyl-2-ethoxymethyl-1-aza-2-sila-cyclopentane was added. In addition, perform the reaction for 15 minutes. After adding 2,6-di-tert-butyl-p-cresol to the polymer solution after the reaction, the solvent is removed by steam stripping, and the rubber is dried with a hot roll to obtain modified SBR-3.
Furthermore, as a result of measuring the microstructure of the obtained modified SBR-3, the styrene content was 35% by mass, and the vinyl content in the butadiene portion was 27%.
*4 SBR-4 is manufactured under the following conditions.
A styrene solution containing 60% by weight of styrene dissolved in n-hexane was added to the first reactor of a continuous reactor in which three reactors were connected in series at a rate of 6.58 kg/h and 1,3% of styrene was dissolved in n-hexane. - 15.10 kg/h of 1,3-butadiene solution with 60% by weight of butadiene dissolved, 49.11 kg/h of n-hexane, 1,2-butadiene with 2.0% by weight of 1,2-butadiene dissolved in n-hexane 40 g/h of the solution, 51.0 g/h of a solution of 10% by weight of 2,2-(di-2(tetrahydrofuryl)propane dissolved in n-hexane as a polar additive, and 51.0 g/h of n-butyllithium in n-hexane). A solution of n-butyllithium dissolved at 10% by mass was injected at a rate of 59.0 g/h, and the temperature of the first group reactor was maintained at 50°C.
Next, a 1,3-butadiene solution containing 60% by mass of 1,3-butadiene dissolved in n-hexane is injected into the second reactor at a rate of 0.95 kg/h. At this time, the temperature of the second reactor was maintained at 65°C.
The polymer is transferred from the second reactor to the third reactor, and a solution containing the following formula (1a) as a modifier is charged into the third reactor (modifier: act. Li=1:1 mol). At this time, the temperature of the third reactor is maintained at 65°C.
Thereafter, a solution of IR1520 (BASF) dissolved at 30% by mass as an antioxidant is injected into the polymerization solution discharged from the third reactor at a rate of 167 g/h and stirred. As a result, the resulting polymer is placed in hot water heated with steam and stirred to remove the solvent, thereby obtaining modified SBR-4 having one end modified.
Further, as a result of measuring the microstructure of the obtained modified SBR-4, the styrene content was 37% by mass, and the vinyl content in the butadiene moiety was 40%.
*5 “Nip Seal AQ” manufactured by Tosoh Silica Co., Ltd., BET surface area 205 m ² /g
*6 "ABC-856" manufactured by Shin-Etsu Chemical Co., Ltd., bis-triethoxysilylpropyl-polysulfide *8 1,3-diphenylguanidine, "Noxela D" manufactured by Ouchi Shinko Chemical Co., Ltd.
*9 N,N'-diethylthiourea, Renogran DETU-80 manufactured by LANXESS
*10 N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, "Nocrac 6C" manufactured by Ouchi Shinko Chemical Co., Ltd.
*11 Di-2-benzothiazolyl disulfide, “Noxela DM-P” manufactured by Ouchi Shinko Chemical Co., Ltd.
*12 N-tert-butyl-2-benzothiazolylsulfenamide, “Noxela NS-P” manufactured by Ouchi Shinko Chemical Co., Ltd.

From the results in Table 1, it was found that each sample of the example showed excellent results in silica dispersibility and low loss property compared to each sample of the comparative example.

According to the present invention, it is possible to provide a method for producing a rubber composition, which can improve the dispersibility of fillers and obtain a rubber composition with excellent low loss properties. Further, according to the present invention, it is possible to provide a rubber composition with excellent low loss properties and a tire with reduced rolling resistance.

Claims (14)

A rubber component (A) containing at least one selected from natural rubber and synthetic diene rubber, a filler containing an inorganic filler (B), a silane coupling agent (C), and a vulcanization accelerator. (D) A method for producing a rubber composition comprising:
kneading the rubber composition in multiple stages;
In the first step of the kneading, the rubber component (A), part or all of the inorganic filler (B), part or all of the silane coupling agent (C), and the vulcanization accelerator ( D) is kneaded;
A method for producing a rubber composition, wherein the rubber component contains a modified copolymer modified with a modifier containing a compound represented by formula (1).
(In the formula, R ₁ to R ₈ are each independently an alkyl group having 1 to 20 carbon atoms; L ₁ and L ₂ are each independently an alkylene group having 1 to 20 carbon atoms; n is an integer from 2 to 4.) The copolymer modified with a modifier containing the compound represented by formula (1) is a copolymer having a conjugated diene unit and an aromatic vinyl unit,
2. The method for producing a rubber composition according to claim 1, wherein the content of the aromatic vinyl unit in the copolymer is 40% by mass or less. The vulcanization accelerator (D) is at least one vulcanization accelerator selected from guanidines, sulfenamides, thiazoles, thiurams, dithiocarbamates, thioureas, and xanthates. A method for producing a rubber composition according to claim 1 or 2, characterized by: The method for producing a rubber composition according to claim 3, wherein the vulcanization accelerator (D) is at least one guanidine vulcanization accelerator. 4. The method for producing a rubber composition according to claim 3, wherein the vulcanization accelerator (D) is at least one thiourea vulcanization accelerator. In the first step of the kneading, after kneading all or a part of the rubber component (A), the inorganic filler (B), and all or a part of the silane coupling agent (C), the accelerator ( The method for producing a rubber composition according to claim 1 or 2, characterized in that D) is added and further kneaded. The method for producing a rubber composition according to claim 1 or 2, wherein the maximum temperature of the rubber composition in the first stage of kneading is 120 to 190°C. According to claim 1 or 2, the silane coupling agent (C) is at least one compound selected from the group consisting of compounds represented by the following general formulas (I) to (IV). A method for producing a rubber composition.
(In the formula, R ¹ may be the same or different when there is a plurality of them, and each R 1 is a straight chain, cyclic or branched alkyl group having 1 to 8 carbon atoms, or a straight chain or branched alkoxyalkyl group having 2 to 8 carbon atoms. group or a hydrogen atom, and when there are multiple R ^2s , they may be the same or different, and each is a linear, cyclic, or branched alkyl group having 1 to 8 carbon atoms, and when there are multiple R ^3s , They may be the same or different, and each is a linear or branched alkylene group having 1 to 8 carbon atoms.a is 2 to 6 on average, p and r may be the same or different, and each has an average value of 2 to 6. The value is 0 to 3. However, both p and r cannot be 3.)
{In the formula, R ⁴ is -Cl, -Br, R ⁹ O-, R ⁹ C(=O)O-, R ⁹ R ¹⁰ C=NO-, R ⁹ R ¹⁰ CNO-, R ⁹ R ¹⁰ N- , and a monovalent group selected from -(OSiR ⁹ R ¹⁰ )h(OSiR ⁹ R ¹⁰ R ¹¹ ) (R ⁹ , R ¹⁰ and R ¹¹ are each a hydrogen atom or a monovalent group having 1 to 18 carbon atoms) h is a hydrocarbon group with an average value of 1 to 4), R ⁵ is R ⁴ , a hydrogen atom or a monovalent hydrocarbon group having 1 to 18 carbon atoms, and R ⁶ is R ⁴ , R ⁵ is a hydrogen atom or a -[O(R ¹² O)j] _0.5 - group (R ¹² is an alkylene group having 1 to 18 carbon atoms, and j is an integer of 1 to 4), R ⁷ is a divalent hydrocarbon group having 1 to 18 carbon atoms, and R ⁸ is a monovalent hydrocarbon group having 1 to 18 carbon atoms. x, y, and z are numbers that satisfy the following relationships: x+y+2z=3, 0≦x≦3, 0≦y≦2, and 0≦z≦1. }
{In the formula, R ¹³ may be the same or different when there are multiple R 13s, each of which is a straight chain, cyclic or branched alkyl group having 1 to 8 carbon atoms, or a straight chain or branched alkoxyalkyl group having 2 to 8 carbon atoms. group or a hydrogen atom, and when there are multiple R ^14s , they may be the same or different, and each is a linear, cyclic, or branched alkyl group having 1 to 8 carbon atoms, and when there are multiple R ^15s , They may be the same or different, and each is a straight chain or branched alkylene group having 1 to 8 carbon atoms.
R ¹⁶ is any of the general formulas (-S-R ¹⁷ -S-), (-R ¹⁸ -S _m1 -R ¹⁹ -) and (-R ²⁰ -S _m2 -R ²¹ -S _m3 -R ²² -) (R ¹⁷ to R ²² are each a divalent hydrocarbon group having 1 to 20 carbon atoms, a divalent aromatic group, or a divalent organic group containing a hetero element other than sulfur and oxygen) , m1, m2, and m3 each have an average value of 1 or more and less than 4.), the plurality of k's may be the same or different, each has an average value of 1 to 6, and s and t each have an average value of The value is 0 to 3. However, both s and t cannot be 3. }
{In the formula, R ²³ is a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, and multiple G's may be the same or different, and each is an alkanediyl group or an alkenediyl group having 1 to 9 carbon atoms. , the plurality of Z ^a may be the same or different, each is a functional group capable of bonding with two silicon atoms, and [-0-] _0.5 , [-0-G-] _{0 .5} and [-O-G-O-] _0.5 , and the plurality of Z ^b 's may be the same or different, and each is a functional group that can bond to two silicon atoms. and is a functional group represented by [-O-G-O-] _0.5 , and the plurality of Z ^c may be the same or different, and each of them is -Cl, -Br, -OR ^a , R ^a A functional group selected from C(=O)O-, R ^a R ^b C=NO-, R ^a R ^b N-, R ^a - and HO-G-O- (G corresponds to the above notation). R ^a and R ^b are each a straight chain, branched or cyclic alkyl group having 1 to 20 carbon atoms. m, n, u, v and w are 1≦m≦20, 0≦n≦20, 0≦u≦3, 0≦v≦2, 0≦w≦1, and (u/2)+v+2w =2 or 3. When there are multiple A parts, Z ^a _u , Z ^b _v and Z ^c _w in the multiple A parts may be the same or different, and when there are multiple B parts, Z ^a in the multiple B parts _u , Z ^b _v and Z ^c _w may be the same or different. } The method for producing a rubber composition according to claim 1 or 2, wherein the inorganic filler (B) is silica. The method for producing a rubber composition according to claim 1 or 2, wherein the filler further contains carbon black. 3. The method for producing a rubber composition according to claim 1, wherein the modifier is one of formulas (1a) to (1e).
Production of the rubber composition according to claim 1 or 2, wherein the modified copolymer is a modified copolymer further modified with a modifier containing a compound represented by formula (2). Method.
(In formula (2), R ₁ to R ₃ each independently represent hydrogen; an alkyl group having 1 to 30 carbon atoms; an alkenyl group having 2 to 30 carbon atoms; an alkynyl group having 2 to 30 carbon atoms; Heteroalkyl group having 1 to 30 carbon atoms, heteroalkenyl group having 2 to 30 carbon atoms; heteroalkynyl group having 2 to 30 carbon atoms; cycloalkyl group having 5 to 30 carbon atoms; aryl group having 6 to 30 carbon atoms; or carbon number 3 to 30 heterocyclic group; R ₄ is a single bond; a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms; a substituted or unsubstituted cyclocarbon group having 5 to 20 carbon atoms; Alkylene group; or a substituted or unsubstituted arylene group having 5 to 20 carbon atoms, where the substituent is an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or It is an aryl group having 6 to 20 carbon atoms, and R ₅ is an alkyl group having 1 to 30 carbon atoms; an alkenyl group having 2 to 30 carbon atoms; an alkynyl group having 2 to 30 carbon atoms; a heteroalkyl group having 1 to 30 carbon atoms; group; heteroalkenyl group having 2 to 30 carbon atoms; heteroalkynyl group having 2 to 30 carbon atoms; cycloalkyl group having 5 to 30 carbon atoms; aryl group having 6 to 30 carbon atoms; heterocyclic group having 3 to 30 carbon atoms or a functional group represented by the following chemical formula (2a) or (2b), where n is an integer of 1 to 5, and at least one of R ₅ is represented by the following chemical formula (2a) or (2b). In the functional group represented, when n is an integer of 2 to 5, a plurality of R _5s may be the same or different from each other.
In formula (2a), R ₆ is a substituent-substituted or unsubstituted alkylene group having 1 to 20 carbon atoms; a substituent substituted or unsubstituted cycloalkylene group having 5 to 20 carbon atoms; or a substituent substituted or an unsubstituted arylene group having 6 to 20 carbon atoms, where the above substituent is an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or an arylene group having 6 to 20 carbon atoms. R ₇ and R ₈ are each independently an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or an aryl group having 6 to 20 carbon atoms substituted or unsubstituted. an alkylene group having 1 to 20 carbon atoms; R ₉ is hydrogen; an alkyl group having 1 to 30 carbon atoms; an alkenyl group having 2 to 30 carbon atoms; an alkynyl group having 2 to 30 carbon atoms; a heteroalkyl group having 1 to 30 carbon atoms. group; heteroalkenyl group having 2 to 30 carbon atoms; heteroalkynyl group having 2 to 30 carbon atoms; cycloalkyl group having 5 to 30 carbon atoms; aryl group having 6 to 30 carbon atoms; heterocyclic group having 3 to 30 carbon atoms and X is an N, O or S atom, and when X is O or S, R9 is absent.
In formula (2b), R ₁₀ is a substituent-substituted or unsubstituted alkylene group having 1 to 20 carbon atoms; a substituent substituted or unsubstituted cycloalkylene group having 5 to 20 carbon atoms; or a substituent substituted or an unsubstituted arylene group having 6 to 20 carbon atoms, where the substituent is an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or an arylene group having 6 to 20 carbon atoms. and R ₁₁ and R ₁₂ are each independently an alkyl group having 1 to 30 carbon atoms; an alkenyl group having 2 to 30 carbon atoms; an alkynyl group having 2 to 30 carbon atoms; a heteroalkyl group having 1 to 30 carbon atoms; Heteroalkenyl group having 2 to 30 carbon atoms; Heteroalkynyl group having 2 to 30 carbon atoms; Cycloalkyl group having 5 to 30 carbon atoms; Aryl group having 6 to 30 carbon atoms; Heterocyclic group having 3 to 30 carbon atoms . ) A rubber composition obtained by the method for producing a rubber composition according to claim 1. A tire characterized by using the rubber composition according to claim 13.