WO2019031538A1

WO2019031538A1 - Method for producing rubber composition

Info

Publication number: WO2019031538A1
Application number: PCT/JP2018/029710
Authority: WO
Inventors: 俊宏信岡
Original assignee: 住友化学株式会社
Priority date: 2017-08-10
Filing date: 2018-08-08
Publication date: 2019-02-14
Also published as: TW201917150A; JP2019034988A

Abstract

The present invention provides a method for producing a rubber composition, which comprises: a step 1 wherein a kneaded product is obtained by kneading silica, a rubber component which has an olefinic double bond, and a compound (C) which has no Si-O bond, while having a group or structure (A) that is reactive with an olefinic double bond and a group or structure (B) that is reactive or interactive with silica; and a step 2 wherein a rubber composition is obtained by kneading the thus-obtained kneaded product with a compound which has an Si-O bond that is capable of forming a bond with silica.

Description

Method of producing rubber composition

The present invention relates to a method for producing a rubber composition and the like.

In recent years, from the request of environmental protection, fuel efficiency improvement (that is, fuel efficiency improvement) of a car is required. And, in the field of automobile tires, it is known that the fuel efficiency of automobiles can be improved by reducing the loss coefficient (tan δ) of a vulcanized rubber composition used for manufacturing tires.

For example, in order to reduce the loss factor of a vulcanized rubber composition, Patent Document 1 describes the formula (D):

[The definition of the group in the formula (D) is as described in Patent Document 1. Formula (D) is described in Patent Document 1 as Formula (I). ]
It is described that at least one of a compound represented by the formula, a salt thereof, a solvate thereof and a solvate of the salt thereof is used.

In addition, in order to reduce the loss factor of the vulcanized rubber composition, Patent Document 2 describes the formula (E):

[The definition of the group in the formula (E) is as described in Patent Document 2. Formula (E) is described in Patent Document 2 as Formula (I). ]
It is described to use the compound represented by

JP, 2013-209605, A JP, 2013-159678, A

There is a need to produce a vulcanized rubber composition having a low loss factor (tan δ) using a rubber component having an olefinic double bond and silica. However, in the prior art, it was difficult to sufficiently reduce the loss factor of the vulcanized rubber composition when using a rubber component having an olefinic double bond (particularly, natural rubber) and silica.

The present invention has been made focusing on the above circumstances, and an object thereof is to produce a vulcanized rubber composition having a low loss coefficient using a rubber component having an olefinic double bond and silica. It is.

The present invention which can achieve the above object is as follows.
[1] Compound (C) having a group or structure (A) capable of reacting with an olefinic double bond, and a group or structure (B) capable of reacting or interacting with silica (C) having no Si-O bond Step 1: Kneading a rubber component having an olefinic double bond and silica to obtain a kneaded product, and kneading the obtained kneaded product and a compound having a Si-O bond capable of binding to silica To obtain a rubber composition,
A method of producing a rubber composition comprising:

[2] The method according to [1] above, wherein the group or structure (A) is a group or structure capable of undergoing a radical reaction or a 1,3-dipolar addition reaction with an olefinic double bond.
[3] The group or structure (A) is an olefinic double bond, an amido group, a maleimide ring, 1H-imidazole ring, a benzoxazole ring, a benzothiazole ring, * -SSO ₃ H or a salt thereof, * -S-S ^{- *, * - C≡N + -O} -, * - C≡N + -N - - *, structure represented by the formula (i), structural formula (ii) or formula, (iii) Structure represented by:

[In the above formula, * represents a bonding position. ]
The method according to [1] above, which is

[4] The method according to any one of the above [1] to [3], wherein the group or the structure (B) is an unsubstituted or substituted amino group, a furan ring, an oxazole ring or a 1H-benzoimidazole ring.

[5] The compound (C) is a compound of the formula (I):

[In the formula (I),
R ¹ is a C _2-12 alkanediyl group which may have one or more substituents, a C _3-10 cycloalkanediyl group which may have one or more substituents, one or more substituents And a divalent C _6-12 aromatic hydrocarbon group which may have the formula, or a combination thereof.
R ² and R ³ each independently have a hydrogen atom, a halogen atom, a hydroxy group, a C _1-6 alkoxy group optionally having one or more substituents, or one or more substituents or represents a C _1-6 alkyl group or one or more may have a substituent group C _6-14 aryl group, or R ² and R ³ are bonded, the carbon atom to which they are attached Taken together, form a C _3-10 cycloalkene diyl group which may have one or more substituents.
R ⁴ is a hydroxy group, a C _1-6 alkoxy group which may have one or more substituents, a C _6-14 aryloxy group which may have one or more substituents, or -NR ⁵ R ⁶ (wherein, R ⁵ and R ⁶ each independently represent a hydrogen atom or a C _1-6 alkyl group which may have one or more substituents).
X represents -NH- or -O-. ]
, A salt thereof, a solvate thereof and a solvate of the salt thereof, and a compound of the formula (II):

[In the formula (II),
R ⁷ and R ⁸ each independently represent a hydrogen atom or a C _1-6 alkyl group which may have one or more substituents, or R ⁷ and R ⁸ are bonded together, and one or more of them are substituted It forms a C _2-12 alkanediyl group which may have a group.
m represents an integer of 2 to 9;
n represents 1 or 2;
^{Mn +} represents H ⁺ or n-valent metal ion. ]
The method according to the above [1], which is at least one selected from the group consisting of compounds represented by

[6] The compound represented by the formula (I) is a compound represented by the formula (Ia):

[In the formula (Ia), R ¹ to R ⁴ and X are as defined above. ]
The method according to [5] above, which is a compound represented by

[7] The method according to the above [5] or [6], wherein R ¹ is a C _2-12 alkanediyl group or a divalent C _6-12 aromatic hydrocarbon group.
[8] The method according to [5] or [6] above, wherein R ¹ is a C _2-12 alkanediyl group or a phenylene group.
[9] The method according to the above [5] or [6], wherein R ¹ is a phenylene group.
[10] The method according to the above [5] or [6], wherein R ¹ is a 1,4-phenylene group.

[11] The method according to any one of the above-mentioned [5] to [10], wherein R ² and R ³ are each independently a hydrogen atom or a C _1-6 alkyl group.
[12] The method according to any one of the above [5] to [10], wherein R ² and R ³ are both hydrogen atoms.

[13] R ⁴ is a hydroxy group, a C _1-6 alkoxy group optionally having one or more substituents, or a C _6-14 aryloxy group optionally having one or more substituents The method according to any one of the above [5] to [12].
[14] The method according to any one of the above [5] to [12], wherein R ⁴ is a hydroxy group or a C _1-6 alkoxy group.
[15] The method according to any one of the above [5] to [12], wherein R ⁴ is a hydroxy group.

[16] The method according to any one of the above-mentioned [5] to [15], wherein X is -NH-.

[17] The compound of the formula (I), a salt thereof, a solvate thereof and a solvate of the salt thereof is a solvate of the salt of the compound represented by the formula (I) [5] The method according to any one of [16].
[18] At least one member selected from the group consisting of a compound represented by the formula (I), a salt thereof, a solvate thereof and a solvate of the salt thereof is a carboxylate of a compound represented by the formula (I) The method according to any one of the above [5] to [16], which is a solvate of
[19] An alkali of carboxylic acid of a compound represented by the formula (I), at least one selected from the group consisting of a compound represented by the formula (I), a salt thereof, a solvate thereof and a solvate of the salt thereof The method according to any one of the above [5] to [16], which is a solvate of a metal salt.
[20] A sodium carboxylate of a compound represented by the formula (I), at least one selected from the group consisting of a compound represented by the formula (I), a salt thereof, a solvate thereof and a solvate of the salt thereof The method according to any one of the above [5] to [16], which is a salt solvate.

[21] Any one of the above [5] to [20], wherein R ⁷ and R ⁸ are each independently preferably a hydrogen atom or a C _1-6 alkyl group optionally having one or more substituents. The method described in one.
[22] The method according to any one of the above [5] to [20], wherein R ⁷ and R ⁸ are both hydrogen atoms.

[23] The method according to any one of the above [5] to [22], wherein m is an integer of 2 to 7.
[24] The method according to any one of the above [5] to [22], wherein m is an integer of 2 to 5.
[25] The method according to any one of the above [5] to [24], wherein n is 1.

[26] The compound represented by the formula (II) is S- (aminoalkyl) thiosulfate, S- (aminoalkyl) thiosulfate, S- (N, N-dialkylaminoalkyl) thiosulfate, S- ( At least one selected from the group consisting of N, N-dialkylaminoalkyl) thiosulfates, S- (N-monoalkylaminoalkyl) thiosulfates and S- (N-monoalkylaminoalkyl) thiosulfates The method according to any one of [5] to [20].
[27] The compound of the above [5] to [20], wherein the compound represented by the formula (II) is at least one selected from the group consisting of S- (aminoalkyl) thiosulfuric acid and S- (aminoalkyl) thiosulfate ] The method as described in any one.
[28] The method according to any one of the above [5] to [20], wherein the compound represented by the formula (II) is S- (aminoalkyl) thiosulfuric acid.
[29] The method according to any one of the above [5] to [20], wherein the compound represented by the formula (II) is S- (3-aminopropyl) thiosulfuric acid.

[30] The method according to any one of the above [1] to [29], wherein the compound having a Si—O bond capable of binding to silica is a silane coupling agent.
[31] The method according to the above [30], wherein the silane coupling agent is a silane coupling agent having a C _1-6 alkoxy group bonded to a silicon atom and a disulfide bond.
[32] Silane coupling agents include bis (3-triethoxysilylpropyl) tetrasulfide, bis (3-triethoxysilylpropyl) disulfide, bis (3-diethoxymethylsilylpropyl) tetrasulfide and bis (3-di The method according to the above [30], which is at least one selected from the group consisting of ethoxymethylsilylpropyl) disulfide.

[33] The method according to any one of the above [1] to [32], wherein the rubber component having an olefinic double bond comprises a diene rubber.
[34] The method according to [33] above, wherein the amount of diene rubber in the rubber component having an olefinic double bond is 50% by weight or more.
[35] The method according to the above [33], wherein the amount of diene rubber in the rubber component having an olefinic double bond is 60 to 100% by weight.
[36] The method according to the above [33], wherein the amount of diene rubber in the rubber component having an olefinic double bond is 75 to 100% by weight.
[37] The method according to any one of the above [1] to [32], wherein the rubber component having an olefinic double bond comprises a diene rubber.

[38] The method according to any one of the above-mentioned [1]-[37], wherein the rubber component having an olefinic double bond contains a natural rubber.
[39] The method according to the above [38], wherein the amount of natural rubber in the rubber component having an olefinic double bond is 50% by weight or more.
[40] The method according to the above [38], wherein the amount of natural rubber in the rubber component having an olefinic double bond is 60 to 100% by weight.
[41] The method according to the above [38], wherein the amount of natural rubber in the rubber component having an olefinic double bond is 70 to 100% by weight.

[42] The method according to any one of the above [1] to [41], wherein the entire use amount of the rubber component having an olefinic double bond in the above method is kneaded in Step 1.
[43] The method according to any one of the above [1] to [41], wherein a part of the amount of the rubber component having an olefinic double bond in the above method may be kneaded in Step 2.
[44] The method according to [43], wherein the amount of the rubber component having an olefinic double bond to be kneaded in Step 2 is 0 to 50% by weight based on the amount used in the method.
[45] The method according to the above [43], wherein the amount of the rubber component having an olefinic double bond to be kneaded in Step 2 is 0 to 40% by weight based on the amount used in the method.

[46] Any of the above-mentioned [1] to [45], wherein the amount of the compound (C) used is 0.1 to 10 parts by weight with respect to 100 parts by weight of the rubber component having an olefinic double bond Or the method described in one.
[47] Any of the above-mentioned [1] to [45], wherein the amount of the compound (C) used is 0.25 to 8 parts by weight with respect to 100 parts by weight of the rubber component having an olefinic double bond Or the method described in one.
[48] Any of the above-mentioned [1] to [45], wherein the amount of the compound (C) used is 0.5 to 4 parts by weight with respect to 100 parts by weight of the rubber component having an olefinic double bond Or the method described in one.

[49] The method according to any one of the above [1] to [48], wherein the entire use amount of the compound (C) in the method is kneaded in Step 1.
[50] The method according to any one of the above [1] to [48], wherein a part of the amount of the compound (C) used in the method may be kneaded in Step 2.
[51] The method according to [50] above, wherein the amount of compound (C) to be kneaded in Step 2 is 0 to 25% by weight in the amount used in the method.
[52] The method according to [50], wherein the amount of the compound (C) to be kneaded in Step 2 is 0 to 10% by weight in the amount used in the method.

[53] The method according to any one of the above [1] to [52], wherein the amount of silica used is 10 to 120 parts by weight with respect to 100 parts by weight of the rubber component having an olefinic double bond. the method of.
[54] Any one of the above [1] to [52], wherein the amount of silica used is 22.5 to 100 parts by weight with respect to 100 parts by weight of the rubber component having an olefinic double bond The method described in.
[55] The method according to any one of the above [1] to [52], wherein the amount of silica used is 35 to 80 parts by weight with respect to 100 parts by weight of the rubber component having an olefinic double bond. the method of.

[56] The method according to any one of the above [1] to [55], wherein the entire amount of silica used in the method is kneaded in Step 1.
[57] The method according to any one of the above [1] to [55], wherein a part of the amount of silica used in the method may be kneaded in Step 2.
[58] The method according to the above [57], wherein the amount of silica to be kneaded in step 2 is 0 to 75% by weight of the amount used in the method.
[59] The method according to the above [57], wherein the amount of silica to be kneaded in step 2 is 0 to 25% by weight of the amount used in the method.

[60] The amount of the compound having a Si-O bond capable of binding to silica is 0.1 to 20 parts by weight with respect to 100 parts by weight of the used amount of the rubber component having an olefinic double bond [ The method according to any one of [1] to [59].
[61] The amount of the compound having a Si-O bond capable of binding to silica is 0.25 to 15 parts by weight with respect to 100 parts by weight of the used amount of the rubber component having an olefinic double bond [ The method according to any one of [1] to [59].
[62] The amount of the compound having a Si-O bond capable of binding to silica is 0.5 to 10 parts by weight with respect to 100 parts by weight of the used amount of the rubber component having an olefinic double bond [ The method according to any one of [1] to [59].

[63] The method according to any one of the above [1] to [62], wherein the entire use amount of the compound having a Si—O bond capable of binding to silica in the above method is kneaded in Step 2.
[64] A part of the used amount of the compound having a Si-O bond capable of binding to silica in the above method may be kneaded in step 1 according to any one of the above [1] to [62] Method.
[65] The method according to [64] above, wherein the amount of the compound having a Si—O bond capable of binding to the silica to be kneaded in Step 1 is 0 to 25% by weight based on the amount used in the method.
[66] The method according to [64] above, wherein the amount of the compound having a Si—O bond capable of binding to the silica to be kneaded in Step 1 is 0 to 10% by weight based on the amount used in the method.

[67] A method for producing a rubber composition containing a sulfur component, comprising kneading the rubber composition obtained by the method according to any one of the above [1] to [66] and the sulfur component. .
[68] The method according to [67], wherein the amount of the sulfur component used is 0.01 to 30 parts by weight with respect to 100 parts by weight of the rubber component having an olefinic double bond.
[69] The method according to [67], wherein the amount of the sulfur component used is 0.1 to 20 parts by weight with respect to 100 parts by weight of the rubber component having an olefinic double bond.
[70] The method according to the above [67], wherein the amount of the sulfur component used is 0.1 to 10 parts by weight with respect to 100 parts by weight of the rubber component having an olefinic double bond.

[71] A method for producing a vulcanized rubber composition, comprising vulcanizing a rubber composition containing a sulfur component obtained by the method according to any one of the above [67] to [70].

[72] A rubber composition obtained by the method according to any one of the above [1] to [66].
[73] A rubber composition containing a sulfur component obtained by the method according to any one of the above [67] to [70].
[74] A vulcanized rubber composition obtained by the method according to [71].

According to the present invention, a rubber composition having an olefinic double bond and silica can be used to produce a vulcanized rubber composition having a low loss coefficient.

<Compound (C)>
The present invention is a compound (C) having a group or structure (A) capable of reacting with an olefinic double bond, and a group or structure (B) capable of reacting or interacting with silica and having no Si—O bond One of the features is the use of As the compound (C), only one type may be used, or two or more types may be used in combination.

The group or structure (A) includes, for example, a group or structure capable of undergoing a radical reaction or 1,3-dipolar addition reaction with an olefinic double bond. More specifically, as the group or structure (A), for example, an olefinic double bond, an amido group, a maleimide ring, 1H-imidazole ring, a benzoxazole ring, a benzothiazole ring, * -SSO ₃ H or a salt thereof , * - S-S - * , * - C≡N + -O -, * - C≡N + -N - - *, structure represented by the formula (i), the formula (ii) structure Or a structure represented by formula (iii):

[In the above formula, * represents a bonding position. ]
Can be mentioned. The above-mentioned amido group, maleimide ring, 1H-imidazole ring, benzoxazole ring and benzothiazole ring may all be monovalent or divalent groups. Examples of the amide group include * -CO-NH _2- *, * -NHCO- *, * -CONH ₂ (wherein, * represents a bonding position). Examples of the maleimide ring include 1-maleimidyl group. As the 1H-imidazole ring, for example, 1-imidazolyl group can be mentioned. Examples of the benzoxazole ring include benzoxazolyl group. As a benzothiazole ring, a benzothiazolyl group is mentioned, for example.

As the group or the structure (B), for example, unsubstituted or substituted amino group (preferably, unsubstituted amino group), furan ring, oxazole ring or 1H-benzoimidazole ring can be mentioned. The above-mentioned furan ring, oxazole ring and 1H-benzoimidazole ring may all be a monovalent group or a divalent group. Examples of the furan ring include 2-furyl group and 3-furyl group. Examples of the oxazole ring include 2-oxazolyl group. Examples of the 1H-benzoimidazole ring include 2-benzoimidazolyl group. The hydrogen atom in the unsubstituted or monosubstituted amino group that the compound (C) has and the oxygen atom in the hydroxy group that the silica has can form a hydrogen bond. Moreover, the nitrogen atom in the amino group which a compound (C) has, and the hydrogen atom in the hydroxyl group which silica has can form a hydrogen bond. In addition, a nitrogen atom and an oxygen atom possessed by the furan ring, the oxazole ring or the 1H-benzoimidazole ring possessed by the compound (C) and a hydrogen atom in a hydroxy group possessed by silica can form a hydrogen bond.

The following compounds may be mentioned as specific examples of the compound (C). However, the present invention is not limited to these compounds [In the following formula, A represents O, S or NH, x represents an integer of 1 to 4 and y and z each independently represent an integer of 1 to 6 Represents.

The compound (C) is preferably of the formula (I):

[In the formula (I),
R ¹ is a C _2-12 alkanediyl group which may have one or more substituents, a C _3-10 cycloalkanediyl group which may have one or more substituents, one or more substituents And a divalent C _6-12 aromatic hydrocarbon group which may have the formula, or a combination thereof.
R ² and R ³ each independently have a hydrogen atom, a halogen atom, a hydroxy group, a C _1-6 alkoxy group optionally having one or more substituents, or one or more substituents or represents a C _1-6 alkyl group or one or more may have a substituent group C _6-14 aryl group, or R ² and R ³ are bonded, the carbon atom to which they are attached Taken together, form a C _3-10 cycloalkene diyl group which may have one or more substituents.
R ⁴ represents a hydroxy group (—OH), a C _1-6 alkoxy group which may have one or more substituents, a C _6-14 aryloxy group which may have one or more substituents, Or -NR ⁵ R ⁶ (wherein, R ⁵ and R ⁶ each independently represent a hydrogen atom or a C _1-6 alkyl group which may have one or more substituents). .
X represents -NH- or -O-. ]
, A salt thereof, a solvate thereof and a solvate of the salt thereof, and a compound of the formula (II):

[In the formula (II),
R ⁷ and R ⁸ each independently represent a hydrogen atom or a C _1-6 alkyl group which may have one or more substituents, or R ⁷ and R ⁸ are bonded together, and one or more of them are substituted It forms a C _2-12 alkanediyl group which may have a group.
m represents an integer of 2 to 9;
n represents 1 or 2;
^{Mn +} represents H ⁺ or n-valent metal ion. ]
And at least one selected from the group consisting of compounds represented by

Hereinafter, the "compound represented by the formula (I)" may be abbreviated as "the compound (I)". The compounds represented by other formulas may be abbreviated as well. Also, "the compound represented by the formula (I), a salt thereof, a solvate thereof and a solvate of the salt thereof" may be abbreviated as "the compound (I) and the like". The compounds (I) and the like and the compound (II) may be used alone or in combination of two or more.

In the following, the definition of groups will be described first.
In the present specification, "C _{x -y} " means that the number of carbon atoms is x or more and y or less (x, y: integer).
In the present specification, examples of the "halogen atom" include fluorine, chlorine, bromine and iodine.

In the present specification, an alkyl group includes both a linear alkyl group and a branched alkyl group. In the present specification, examples of the "C _1-6 alkyl group" include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, isopropyl group, sec-butyl group, t-butyl group, 2 And -methylbutyl group, 2-ethylbutyl group, 3-methylbutyl group, 3-ethylbutyl group, 2-methylpentyl group, 3-methylpentyl group and 4-methylpentyl group.

As a substituent which a C _1-6 alkyl group may have, for example, a halogen atom, a C _1-6 alkoxy group, a C _1-6 alkoxy-carbonyl group, a C _1-7 acyl group, C _1-7 Examples include an acyl-oxy group and a C _6-14 aryl group which may have one or more substituents.

In the present specification, examples of the “C _6-14 aryl group” include a phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group and 9-anthryl group.

The substituent which the C _6-14 aryl group may have is, for example, a halogen atom, a C _1-6 alkyl group, a C _1-6 alkoxy group, a C _1-6 alkoxy-carbonyl group, C _1-7 Examples include an acyl group, a C _1-7 acyl-oxy group, a C _6-14 aryl group, and a sulfo group.

In the present specification, an alkoxy group includes both a linear alkoxy group and a branched alkoxy group. In the present specification, examples of the "C _1-6 alkoxy group" include, for example, methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, isobutoxy group, sec-butoxy group, tert-butoxy group, pentyloxy group And hexyloxy group.

As a substituent which a C _1-6 alkoxy group may have, for example, a halogen atom, a C _1-6 alkoxy group, a C _1-6 alkoxy-carbonyl group, a C _1-7 acyl group, C _1-7 Examples include an acyl-oxy group and a C _6-14 aryl group which may have one or more substituents.

In the present specification, examples of the "C _6-14 aryl group" included in the C _6-14 aryloxy group include the above-mentioned ones.

In the present specification, examples of the "C _1-7 acyl group" include a formyl group, a C _1-6 alkyl-carbonyl group (eg, an acetyl group, a pivaloyl group), and a benzoyl group.

In the present specification, examples of the “C _1-6 alkoxy group” included in the C _1-6 alkoxy-carbonyl group and the “C _1-7 acyl group” included in the C _1-7 acyl-oxy group include, for example, the above-mentioned The ones of

As used herein, alkanediyl groups include both linear alkanediyl groups and branched alkanediyl groups. In the present specification, examples of “C _2-12 alkanediyl group” include ethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, propylene group, 1-methyltrimethylene group, 2-methyl group Trimethylene, 1-ethyltrimethylene, 2-ethyltrimethylene, 1-propyltrimethylene, 2-propyltrimethylene, 1-methyltetramethylene, 2-methyltetramethylene, 1-ethyltetra Methylene group, 2-ethyltetramethylene group, 1-propyltetramethylene group, 2-propyltetramethylene group, 1-methylpentamethylene group, 2-methylpentamethylene group, 3-methylpentamethylene group, 1-ethylpentamethylene group Group, 2-ethylpentamethylene group, 3-ethylpentamethylene group, 1-propyl Lupentamethylene, 2-propylpentamethylene, 3-propylpentamethylene, 1-methylhexamethylene, 2-methylhexamethylene, 3-methylhexamethylene, 1-ethylhexamethylene, 2-ethyl Examples include hexamethylene, 3-ethylhexamethylene, 1-propylhexamethylene, 2-propylhexamethylene and 3-propylhexamethylene.

Examples of the substituent that the C _2-12 alkanediyl group may have include a halogen atom, a C _1-6 alkoxy group, a C _1-6 alkoxy-carbonyl group, a C _1-7 acyl group, and a C _1- group. Examples include ₇ acyl-oxy groups and C _6-14 aryl groups which may have one or more substituents.

In the present specification, as the "C _3-10 cycloalkanediyl group", for example, cyclopropane-1,2-diyl group, cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane Examples thereof include a 1,4-diyl group, a cycloheptane-1,4-diyl group, a cyclooctane-1,5-diyl group, a cyclononane-1,5-diyl group, and a cyclodecane-1,6-diyl group.

Examples of the substituent that the C _3-10 cycloalkanediyl group may have include a halogen atom, a C _1-6 alkyl group, a C _1-6 alkoxy group, a C _1-6 alkoxy-carbonyl group, and C _{1 -7} acyl group, C _1-7 acyl-oxy group, C _6-14 aryl group which may have one or more substituents.

In the present specification, examples of the "C _3-10 cycloalkene diyl group" include cyclopropene-1,2-diyl group, cyclobutene-1,2-diyl group, cyclopentene-1,2-diyl group, cyclohexene-. There may be mentioned 1,2-diyl group, cycloheptene-1,2-diyl group, cyclooctene-1,2-diyl group, cyclononene-1,2-diyl group and cyclodecene-1,2-diyl group.

As the substituent which the C _3-10 cycloalkene diyl group may have, for example, a halogen atom, a C _1-6 alkyl group, a C _1-6 alkoxy group, a C _1-6 alkoxy-carbonyl group, C _{1 -7} acyl group, C _1-7 acyl-oxy group, C _6-14 aryl group which may have one or more substituents.

In the present specification, examples of the “divalent C _6-12 aromatic hydrocarbon group” include a phenylene group (eg, 1,4-phenylene group) and a naphthylene group (eg, 1,4-naphthylene group, 1 And 5, 5-naphthylene group, 2,6-naphthylene group, 2,7-naphthylene group), biphenyldiyl group (eg, 1,1'-biphenyl-4,4'-diyl group).

Examples of the substituent that the divalent C _6-12 aromatic hydrocarbon group may have include a halogen atom, a C _1-6 alkyl group, a C _1-6 alkoxy group, and a C _1-6 alkoxy-carbonyl. Groups, C _1-7 acyl groups, C _1-7 acyl-oxy groups, C _6-14 aryl groups, and sulfo groups. The sulfo group is a group represented by —SO ₃ H.

Next, preferable groups and the like in the formula (I) will be described.
R ¹ is preferably a C _2-12 alkanediyl group or a divalent C _6-12 aromatic hydrocarbon group, more preferably a C _2-12 alkanediyl group or a phenylene group, still more preferably a phenylene group Particularly preferred is a 1,4-phenylene group.

R ² and R ³ are each independently preferably a hydrogen atom or a C _1-6 alkyl group, and more preferably a hydrogen atom.

R ⁴ is preferably a hydroxy group, a C _1-6 alkoxy group which may have one or more substituents, or a C _6-14 aryloxy group which may have one or more substituents. More preferably, it is a hydroxy group or a C _1-6 alkoxy group, more preferably a hydroxy group.
X is preferably -NH-.

The compound (I) is preferably of the formula (Ia):

[In the formula (Ia), R ¹ to R ⁴ and X are as defined above. ]
It is a compound represented by

As the salt of compound (I), (a) an amine salt formed by -NH ₂ of compound (I) and another acid, (b) when X is -NH-, -NH of compound (I) Amine salts formed by-and other acids, and (c) when R ⁴ is a hydroxy group (-OH), carboxylic acid salts formed by -COOH of the compound (I) and other bases can be mentioned. . The other acid forming the amine salt of (a) and (b) may be either an organic acid or an inorganic acid, and the base forming the carboxylate of (c) is an organic base or an inorganic base Any one may be used. The salt of compound (I) is preferably a carboxylic acid salt, more preferably at least one selected from the group consisting of carboxylic acid alkali metal salts and carboxylic acid alkaline earth metal salts, still more preferably carboxylic acid alkali Metal salts, particularly preferably sodium carboxylates.

The solvent for forming the solvate of Compound (I) and the solvate of the salt of Compound (I) may be water or an organic solvent (eg, methanol). The solvent that forms a solvate is preferably water or methanol, more preferably water.

In one aspect of the present invention, compound (I) etc. is preferably a solvate of a salt of compound (I), more preferably a solvate of a carboxylate of compound (I), and still more preferably It is a solvate of a carboxylic acid alkali metal salt, particularly preferably a solvate of a carboxylic acid sodium salt. In this aspect, compound (I) is desirably compound (Ia).

Specific examples of the compound (I) or a salt thereof are shown below.

Compound (I) etc. can be produced by the method described in Patent Document 1 or a method according to the method.

Next, preferable groups and the like in the formula (II) will be described.
R ⁷ and R ⁸ are each independently preferably a hydrogen atom or a C _1-6 alkyl group which may have one or more substituents, more preferably a hydrogen atom.

m is preferably an integer of 2 to 7, more preferably an integer of 2 to 5.
n is preferably 1.

Examples of n-valent metal ions include alkali metal ions (eg, lithium ion, sodium ion, potassium ion, cesium ion), alkaline earth metal ions (eg, magnesium ion, calcium ion, strontium ion, barium ion), Manganese ion, iron ion, copper ion, zinc ion and the like can be mentioned. ^{Mn +} is preferably H ⁺ or an alkali metal ion, more preferably H ⁺ or a sodium ion, and still more preferably H ⁺ .

As the compound (II), for example, S- (aminoalkyl) thiosulfuric acid, S- (aminoalkyl) thiosulfate, S- (N, N-dialkylaminoalkyl) thiosulfuric acid, S- (N, N-dialkyl) And aminoalkyl) thiosulfates, S- (N-monoalkylaminoalkyl) thiosulfates, S- (N-monoalkylaminoalkyl) thiosulfates and the like.

As S- (aminoalkyl) thiosulfuric acid, for example, S- (2-aminoethyl) thiosulfuric acid, S- (3-aminopropyl) thiosulfuric acid, S- (4-aminobutyl) thiosulfuric acid, S- (5) -Aminopentyl) thiosulfate, S- (6-aminohexyl) thiosulfate, S- (7-aminoheptyl) thiosulfate, S- (8-aminooctyl) thiosulfate, S- (9-aminononyl) thiosulfate etc. Can be mentioned.

Examples of S- (aminoalkyl) thiosulfates include sodium S- (2-aminoethyl) thiosulfate, sodium S- (3-aminopropyl) thiosulfate, sodium S- (4-aminobutyl) thiosulfate, Sodium S- (5-aminopentyl) thiosulfate, sodium S- (6-aminohexyl) thiosulfate, sodium S- (7-aminoheptyl) thiosulfate, sodium S- (8-aminooctyl) thiosulfate, S- Examples include sodium (9-aminononyl) thiosulfate and the like.

As S- (N, N-dialkylaminoalkyl) thiosulfuric acid, for example, S- (2-N, N-dimethylaminoethyl) thiosulfuric acid, S- (3-N, N-dimethylaminopropyl) thiosulfuric acid, S- (4-N, N-Dimethylaminobutyl) thiosulfate, S- (5-N, N-Dimethylaminopentyl) thiosulfate, S- (6-N, N-dimethylaminohexyl) thiosulfate, S- Examples thereof include (7-N, N-dimethylaminoheptyl) thiosulfuric acid, S- (8-N, N-dimethylaminooctyl) thiosulfuric acid, S- (9-N, N-dimethylaminononyl) thiosulfuric acid and the like.

Examples of S- (N, N-dialkylaminoalkyl) thiosulfates include sodium S- (2-N, N-dimethylaminoethyl) thiosulfate, S- (3-N, N-dimethylaminopropyl) thio Sodium sulfate, sodium S- (4-N, N-dimethylaminobutyl) thiosulfate, sodium S- (5-N, N-dimethylaminopentyl) thiosulfate, S- (6-N, N-dimethylaminohexyl) Sodium thiosulphate, sodium S- (7-N, N-dimethylaminoheptyl) thiosulphate, sodium S- (8-N, N-dimethylamino octyl) thiosulphate, S- (9-N, N-dimethylaminononyl) And sodium thiosulfate etc.

Examples of S- (N-monoalkylaminoalkyl) thiosulfuric acid include S- (2-N-methylaminoethyl) thiosulfuric acid, S- (3-N-methylaminopropyl) thiosulfuric acid, S- (4- N-methylaminobutyl) thiosulfuric acid, S- (5-N-methylaminopentyl) thiosulfuric acid, S- (6-N-methylaminohexyl) thiosulfuric acid, S- (7-N-methylaminoheptyl) thiosulfuric acid And S- (8-N-methylaminooctyl) thiosulfuric acid, S- (9-N-methylaminononyl) thiosulfuric acid and the like.

Examples of S- (N-monoalkylaminoalkyl) thiosulfates include sodium S- (2-N-methylaminoethyl) thiosulfate, sodium S- (3-N-methylaminopropyl) thiosulfate, S- Sodium (4-N-methylaminobutyl) thiosulfate, sodium S- (5-N-methylaminopentyl) thiosulfate, sodium S- (6-N-methylaminohexyl) thiosulfate, S- (7-N- Examples include sodium methylaminoheptyl) thiosulfate, sodium S- (8-N-methylaminooctyl) thiosulfate, sodium S- (9-N-methylaminononyl) thiosulfate and the like.

The compound (II) is preferably at least one selected from the group consisting of S- (aminoalkyl) thiosulfuric acid and S- (aminoalkyl) thiosulfate, more preferably S- (aminoalkyl) thiosulfuric acid More preferably S- (3-aminopropyl) thiosulfuric acid.

Compound (II) can be produced by the method described in Patent Document 2 or a method analogous to the method.

The amount of compound (C) used in the present invention is preferably 0.1 to 10 parts by weight, more preferably 0.25 to 8 parts by weight, per 100 parts by weight of the rubber component having an olefinic double bond. Part, more preferably 0.5 to 4 parts by weight.

<Rubber component having an olefinic double bond>
The present invention is characterized by using a rubber component having an olefinic double bond. The rubber component having an olefinic double bond may be used alone or in combination of two or more.

As rubber components having an olefinic double bond, natural rubber (NR) and modified natural rubber (eg, epoxidized natural rubber, deproteinized natural rubber); styrene butadiene copolymer rubber (SBR), polybutadiene rubber (BR) And various synthetic rubbers such as acrylonitrile butadiene copolymer rubber (NBR) and ethylene propylene diene copolymer rubber (EPDM).

The rubber component having an olefinic double bond preferably comprises a diene rubber. Here, a diene rubber means rubber which used the diene monomer which has a conjugated double bond as a raw material. Examples of the diene rubber include natural rubber, modified natural rubber, chloroprene rubber, styrene-butadiene copolymer rubber, polybutadiene rubber, nitrile rubber and the like. The diene rubber is preferably highly unsaturated, and more preferably a natural rubber. In addition, it is also effective to use natural rubber and another rubber (for example, styrene butadiene copolymer rubber, polybutadiene rubber) in combination.

As an example of natural rubber, natural rubber of grades such as RSS # 1, RSS # 3, TSR20, SIR20 can be mentioned. Examples of the epoxidized natural rubber include those having an epoxidation degree of 10 to 60% by mole (for example, ENR 25 and ENR 50 manufactured by Kumpulan Guthrie). As the deproteinized natural rubber, deproteinized natural rubber having a total nitrogen content of 0.3% by weight or less is preferable. Other modified natural rubbers include, for example, polar groups obtained by reacting natural rubber with 4-vinylpyridine, N, N-dialkylaminoethyl acrylate (eg, N, N-diethylaminoethyl acrylate), 2-hydroxy acrylate, etc. And modified natural rubber.

Examples of SBR include emulsion-polymerized SBR and solution-polymerized SBR described on pages 210 to 211 of "Rubber Industry Handbook <Fourth Edition>" edited by The Japan Rubber Association. Among them, for the rubber composition for tread, solution polymerization SBR is preferable.

The solution-polymerized SBR includes a modified solution-polymerized SBR obtained by modifying with a modifier and having at least one element of nitrogen, tin and silicon at the molecular end. Examples of modifiers include lactam compounds, amide compounds, urea compounds, N, N-dialkylacrylamide compounds, isocyanate compounds, imide compounds, silane compounds having an alkoxy group, aminosilane compounds, silane compounds having a tin compound and an alkoxy group And the combined use modifier of the alkyl acrylamide compound and the silane compound having an alkoxy group. These modifiers may be used alone or in combination of two or more. Specifically, as the modified solution-polymerized SBR, solution-polymerized SBR, JSR in which the molecular terminal is modified with 4,4′-bis (dialkylamino) benzophenone such as “Nipol (registered trademark) NS116” manufactured by Zeon Corporation. Examples thereof include solution-polymerized SBR in which the molecular terminal is modified with a halogenated tin compound such as "SL 574" manufactured by corporation, and silane-modified solution-polymerized SBR such as "E10" and "E15" manufactured by Asahi Kasei Corporation.

In addition, oil-extended SBR in which an oil such as a process oil or an aroma oil is added to the emulsion-polymerized SBR and solution-polymerized SBR is also preferable for the rubber composition for a tread.

As BR, either low vinyl content solution polymerization BR or high vinyl content solution polymerization BR may be used, but high vinyl content solution polymerization BR is preferable. Particularly preferred is a modified solution-polymerized BR having at least one element of nitrogen, tin and silicon at its molecular end, which is obtained by modifying with a modifier. Examples of the modifier include 4,4′-bis (dialkylamino) benzophenone, tin halide compounds, lactam compounds, amide compounds, urea compounds, N, N-dialkylacrylamide compounds, isocyanate compounds, imide compounds, and alkoxy groups. Silane compounds (for example, trialkoxysilane compounds), aminosilane compounds, combination modifiers of a tin compound and a silane compound having an alkoxy group, combination modifiers of an alkylacrylamide compound and a silane compound having an alkoxy group, and the like. These modifiers may be used alone or in combination of two or more. Examples of the modified solution-polymerized BR include tin-modified BR such as "Nipol (registered trademark) BR 1250H" manufactured by Zeon Corporation.

BR can be preferably used for the rubber composition for treads and the rubber composition for sidewalls. BR may be used in blends with SBR and / or natural rubber (NR). In the rubber composition for tread, for example, the amount of SBR and / or NR is 60 to 100% by weight, and the amount of BR is 0 to 40% by weight in the rubber component having an olefinic double bond. In the rubber composition for a sidewall, preferably, the amount of SBR and / or NR is 10 to 70% by weight, and the amount of BR is 90 to 30% by weight in the rubber component having an olefinic double bond, More preferably, the amount of NR is 40 to 60% by weight and the amount of BR is 60 to 40% by weight. For the rubber composition for tread and the rubber composition for sidewalls, a blend of modified SBR and non-modified SBR, a blend of modified BR and non-modified BR, and the like can also be preferably used.

When the rubber composition is used for the tread of a tire, for example, in a passenger car tire, SBR, which is excellent in wear resistance and hysteresis loss reduction performance as a rubber component having an olefinic double bond, is used as a base material for truck and bus In the tire, it is possible to optionally use a higher strength NR as a base material together with SBR, and optionally blend BR into these base materials, thereby providing a tread excellent in wear resistance, fatigue resistance and resilience. It is preferable because it can be obtained.

When the rubber composition is used for the sidewall of a tire, it is a blend of NR and SBR in a passenger car tire, or a blend of NR and BR, and a blend of NR and BR in a truck and bus tire. It is preferable to use it as it is resistant to bending and bending and crack growth resistance.

When the rubber composition is used for a belt of a tire, using NR and / or IR as a rubber component having an olefinic double bond provides high elasticity and good adhesion to reinforcing fibers. Because it is preferable.

When the rubber composition is used as an inner liner of a tire, it is preferable to blend IIR with SBR and NR as a rubber component having an olefinic double bond, or to use IIR with NR as a blend. It is preferable because permeability and bending resistance can be obtained.

As mentioned above, the rubber component having an olefinic double bond preferably comprises a diene rubber. When a diene rubber is used, the amount of diene rubber in the rubber component having an olefinic double bond is preferably 50% by weight or more, more preferably 60 to 100% by weight, still more preferably 75 to 100% by weight It is. Most preferably, the rubber component having an olefinic double bond comprises a diene rubber.

The rubber component having an olefinic double bond more preferably contains a natural rubber. When natural rubber is used, the amount of natural rubber in the rubber component having an olefinic double bond is preferably 50% by weight or more, more preferably 60 to 100% by weight, still more preferably 70 to 100% by weight .

<Silica>
The present invention is characterized by using silica. Examples of the silica include (i) silica having a pH of 6 to 8, (ii) silica containing 0.2 to 1.5% by weight of sodium, and (iii) a true spherical shape having a circularity of 1 to 1.3. Silica, (iv) Silicone oil (eg, dimethyl silicone oil), organosilicon compound containing ethoxysilyl group, silica surface-treated with alcohol (eg, ethanol, polyethylene glycol), etc., (v) two or more different types A mixture of silica having a surface area may, for example, be mentioned. These may use only 1 type and may use 2 or more types together.

Examples of commercially available products of silica include “Nipsil (registered trademark) AQ” manufactured by Tosoh Silica Corporation, “Nipsil (registered trademark) AQ-N”, “Ultrasil (registered trademark) VN 3” manufactured by Degussa, “Ultrasil” (Registered trademark) VN3-G, "Ultrasil (registered trademark) 360", "Ultrasil (registered trademark) 7000", "Zeosil (registered trademark) 115 GR" manufactured by Rhodia, "Zeosil (registered trademark) 1115 MP", "Zeosyl (registered trademark) 1205MP" and "Zeosyl (registered trademark) Z85MP" can be mentioned.

The BET specific surface area of the silica is preferably 20 to 400 m ² / g, more preferably 20 to 350 m ² / g, and still more preferably 20 to 300 m ² / g. This BET specific surface area can be measured by a multipoint nitrogen adsorption method (BET method).

The amount of silica used in the present invention is preferably 10 to 120 parts by weight, more preferably 22.5 to 100 parts by weight, still more preferably 100 parts by weight of the rubber component having an olefinic double bond. 35 to 80 parts by weight.

<Compound having Si—O bond that can bind to silica>
One of the features of the present invention is to use a compound having a Si-O bond capable of binding to silica. The compound having a Si—O bond capable of binding to silica may be used alone or in combination of two or more.

Examples of compounds having a Si-O bond capable of binding to silica include, for example, bis (3-triethoxysilylpropyl) tetrasulfide (for example, “Si-69” manufactured by Degussa), bis (3-triethoxysilylpropyl) Disulfide (eg, Degussa “Si-75”), bis (3-diethoxymethylsilylpropyl) tetrasulfide, bis (3-diethoxymethylsilylpropyl) disulfide, 3-octanoylthiopropyltriethoxysilane (alias) “Octanethio acid S- [3- (triethoxysilyl) propyl] ester”, such as “NXT silane” manufactured by General Electronic Silicon's, octanethio acid S- [3-{(2-methyl-1,3-, Propanedialkoxy) ethoxysilyl} propyl] ester, ok N-thioic acid S- [3-{(2-methyl-1,3-propanedialkoxy) methylsilyl} propyl] ester, methyltrimethoxysilane, methyltriethoxysilane, methyltriacetoxysilane, methyltributoxysilane, ethyltrimethoxy Silane, ethyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, n-octyltrimethoxysilane, n-octyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (methoxyethoxy) silane, phenyltriethoxysilane Methoxysilane, phenyltriethoxysilane, phenyltriacetoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-aminopropyl Trimethoxysilane, 3-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltriethoxysilane, (3- Cidoxypropyl) trimethoxysilane, (3-glycidoxypropyl) triethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl Examples include triethoxysilane, 3-isocyanatopropyltrimethoxysilane and 3-isocyanatopropyltriethoxysilane.

As a compound having a Si—O bond capable of binding to silica, a silane coupling agent is preferred. The silane coupling agent may be used alone or in combination of two or more. Here, the silane coupling agent means a silane compound having a functional group capable of binding to an inorganic material (for example, silica) and a functional group capable of binding to an organic material (for example, a rubber component). Examples of the functional group capable of binding to the inorganic material include, for example, a _C1-6 alkoxy group bonded to a silicon atom, a hydroxy group bonded to a silicon atom and the like, and a _C1-6 alkoxy group bonded to a silicon atom is preferable . Examples of the functional group capable of binding to the organic material include, for example, a disulfide bond (S-S), an amino group and the like, and a disulfide bond is preferable. The silane coupling agent is preferably a silane coupling agent having a C _1-6 alkoxy group bonded to a silicon atom and a disulfide bond. As such a silane coupling agent, for example, bis (3-triethoxysilylpropyl) tetrasulfide (for example, “Si-69” manufactured by Degussa), bis (3-triethoxysilylpropyl) disulfide (for example, Degussa) Company “Si-75”), bis (3-diethoxymethylsilylpropyl) tetrasulfide, bis (3-diethoxymethylsilylpropyl) disulfide and the like.

The amount of the compound having a Si-O bond capable of binding to silica in the present invention is preferably 0.1 to 20 parts by weight, preferably 100 parts by weight, based on 100 parts by weight of the rubber component having an olefinic double bond. Preferably, it is 0.25 to 15 parts by weight, more preferably 0.5 to 10 parts by weight.

<Sulfur component>
Sulfur components that can be used in the present invention include, for example, powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, and highly dispersible sulfur, morpholine disulfide, tetramethylthiuram disulfide. Powdered sulfur is usually preferred, and insoluble sulfur is preferred when the rubber composition is used for the production of tire components having a high sulfur content such as belt components.

The amount of the sulfur component used in the present invention is preferably 0.01 to 30 parts by weight, more preferably 0.1 to 20 parts by weight, based on 100 parts by weight of the rubber component having an olefinic double bond. More preferably, it is 0.1 to 10 parts by weight.

<Other ingredients>
In the present invention, other components different from the above-mentioned components (compound (C), rubber component having an olefinic double bond, silica, compound having a Si—O bond capable of binding to silica, and sulfur component) are used You may Other components include, for example, other fillers different from silica, monohydric alcohols, polyhydric alcohols, vulcanization accelerators, vulcanization accelerators, resins, anti-aging agents, oils, waxes, peptizers, A retarder, a compound having an oxyethylene unit, a catalyst (eg, cobalt naphthenate etc.) can be mentioned. All other components may be used alone or in combination of two or more.

Other fillers include, for example, carbon black, aluminum hydroxide, ground bituminous coal, talc, clay (especially calcined clay), titanium oxide. When other fillers are used, the amount thereof is preferably 0 to 70% by weight, more preferably 5 to 50% by weight, based on the total amount of the silica used in the present invention and the other fillers used. More preferably, it is 10 to 25% by weight.

As another filler, carbon black is preferable. When carbon black is used, its amount is preferably 0 to 70% by weight, more preferably 5 to 50% by weight, still more preferably 10 based on the total amount of silica and carbon black used in the present invention. It is ̃25% by weight.

Examples of carbon black include those described on page 494 of "Rubber Industry Handbook <Fourth Edition>" edited by The Japan Rubber Association. Carbon black may use only 1 type and may use 2 or more types together. Examples of carbon black include HAF (High Abrasion Furnace), SAF (Super Abrasion Furnace), ISAF (Intermediate SAF), ISAF-HM (Intermediate SAF-High Modulus), FEF (Fast Extrusion Furnace), MAF (Medium Abrasion Furnace) And GPF (General Purpose Furnace) and SRF (Semi-Reinforcing Furnace).

The BET specific surface area of carbon black is preferably 10 to 130 m ² / g, more preferably 20 to 130 m ² / g, and still more preferably 40 to 130 m ² / g. This BET specific surface area can be measured by a multipoint nitrogen adsorption method (BET method).

Examples of aluminum hydroxide include aluminum hydroxide having a nitrogen adsorption specific surface area of 5 to 250 m ² / g and a DOP oil supply amount of 50 to 100 ml / 100 g.

The average particle diameter of the bituminous coal pulverized material is usually 0.1 mm or less, preferably 0.05 mm or less, more preferably 0.01 mm or less. Even if a pulverized bituminous coal having an average particle size of more than 0.1 mm is used, the hysteresis loss of the rubber composition may not be sufficiently reduced, and the fuel economy may not be sufficiently improved. Moreover, when using a rubber composition as a composition for inner liners, even if it uses a bituminous coal pulverized material whose average particle diameter exceeds 0.1 mm, the air-permeability-proof property of this composition can not fully be improved. is there.

Although the lower limit of the average particle diameter of the bituminous coal pulverized material is not particularly limited, it is preferably 0.001 mm or more. If it is less than 0.001 mm, the cost tends to be high. The average particle diameter of the bituminous coal pulverized material is a mass-based average particle diameter calculated from a particle size distribution measured in accordance with JIS Z 8815-1994.

1.6 or less is preferable, as for the specific gravity of a bituminous coal grinding material, 1.5 or less is more preferable, and 1.3 or less is more preferable. When the bituminous coal pulverized material having a specific gravity of more than 1.6 is used, the specific gravity of the whole rubber composition may be increased, and the improvement of the fuel economy of the tire may not be sufficiently achieved. 0.5 or more is preferable and, as for the specific gravity of a bituminous coal grinding material, 1.0 or more is more preferable. When using a bituminous coal pulverized material having a specific gravity of less than 0.5, the processability at the time of kneading may be deteriorated.

In the present invention using silica, a monohydric alcohol and a polyhydric alcohol may be used together with a compound having a Si—O bond capable of binding to silica. Examples of monohydric alcohols include ethanol, butanol, octanol and the like. Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, pentaerythritol, and polyether polyols. Further, in the present invention, liquid polybutadiene or the like whose molecular terminal is carboxy- or amine-modified may be used.

As an example of a vulcanization accelerator, thiazole-based vulcanization accelerators and sulches described on pages 412 to 413 of the Rubber Industry Handbook <Fourth Edition> (issued by The Japan Rubber Association, January 20, 1994) There may be mentioned phenamide-based vulcanization accelerators and guanidine-based vulcanization accelerators.

Specific examples of the vulcanization accelerator include N-cyclohexyl-2-benzothiazolylsulfenamide (CBS), N-tert-butyl-2-benzothiazolylsulfenamide (BBS), N, N-dicyclo These include xyl-2-benzothiazolylsulfenamide (DCBS), 2-mercaptobenzothiazole (MBT), dibenzothiazyl disulfide (MBTS), diphenyl guanidine (DPG).

The ratio of sulfur component to vulcanization accelerator is not particularly limited, but the weight ratio of sulfur component to vulcanization accelerator is preferably 1/10 to 10/1, more preferably 1/5 to 5/1, and further Preferably, it is 1/2 to 2/1. Also, in a rubber member containing natural rubber as a main component, EV vulcanization with a sulfur component / vulcanization accelerator ratio of 1 or less, which is a method of improving heat resistance, is preferably used in applications where heat resistance improvement is particularly required. Be

As the accelerator, for example, zinc oxide, stearic acid, citraconic imide compound, alkylphenol-sulfur chloride condensate, organic thiosulphate compound and formula (III):
R ¹⁶ -S-S-R ¹⁷ -S-S-R ¹⁸ (III)
(Wherein, R ¹⁷ represents a C _2-10 alkanediyl group, and R ¹⁶ and R ¹⁸ each independently represent a monovalent organic group containing a nitrogen atom).
The compound represented by these is mentioned. In the present invention, zinc oxide is included in the concept of a vulcanization acceleration coagent, and is not included in the concept of the filler described above.

As the vulcanization acceleration assistant, zinc oxide, stearic acid and citraconic imide compounds are preferable, and zinc oxide and stearic acid are more preferable.

When zinc oxide is used, its amount is preferably 0.01 to 20 parts by weight, more preferably 0.1 to 15 parts by weight, per 100 parts by weight of the rubber component having an olefinic double bond. Parts, more preferably 0.1 to 10 parts by weight. When stearic acid is used, its amount is preferably 0.01 to 15 parts by weight, more preferably 0.1 to 10 parts by weight, per 100 parts by weight of the rubber component having an olefinic double bond. Part, more preferably 0.1 to 5 parts by weight.

As the citraconic imide compound, biscitraconimides are preferable because they are thermally stable and are excellent in dispersibility in a rubber component having an olefinic double bond. Specifically, 1,2-biscitraconimidomethylbenzene, 1,3-biscitraconimidomethylbenzene, 1,4-biscitraconimidomethylbenzene, 1,6-biscitraconimidomethylbenzene, 2,3-bis Citraconimidomethyltoluene, 2,4-biscitraconimidomethyltoluene, 2,5-biscitraconimidomethyltoluene, 2,6-biscitraconimidomethyltoluene, 1,2-biscitraconimidoethylbenzene, 1,3-biscitracon Imidoethylbenzene, 1,4-biscitraconimidoethylbenzene, 1,6-biscitraconimidoethylbenzene, 2,3-biscitraconimidoethyltoluene, 2,4-biscitraconimidoethyltoluene, 2,5-biscitraconimidoethyltoluene Emissions, such as 2,6-biscitraconimide ethyltoluene and the like.

Among the citraconic imide compounds, it is particularly stable thermally, and particularly excellent in dispersibility in a rubber component having an olefinic double bond, and a vulcanized rubber composition having high hardness (Hs) can be obtained ( For the reason of reversion control, 1,3-biscitraconimidomethylbenzene represented by the following formula is preferable.

Formula (IV): The vulcanized rubber composition of high hardness (Hs) can be obtained as a vulcanization acceleration assistant.

[Wherein, n is an integer of 0 to 10, each X is independently an integer of 2 to 4, and each R ¹⁹ is independently a C _5-12 alkyl group. ]
It is preferable to use an alkylphenol-sulfur chloride condensate represented by

N is preferably an integer of 1 to 9 because the dispersibility of the alkylphenol-sulfur chloride condensate (IV) in the rubber component having an olefinic double bond is good.

When X is more than 4, the alkylphenol-sulfur chloride condensate (IV) tends to be thermally unstable, and when X is 1, the sulfur content in the alkylphenol-sulfur chloride condensate (IV) (sulfur Less weight). It is preferable that X is 2 because high hardness can be expressed efficiently (reversion suppression).

R ¹⁹ is a C _5-12 alkyl group. R ¹⁹ is preferably a C _6-9 alkyl group because the dispersibility of the alkylphenol-sulfur chloride condensate (IV) in the rubber component having an olefinic double bond is good.

A specific example of the alkylphenol-sulfur chloride condensate (IV): n is 0 to 10, X is 2, R ¹⁹ is an octyl group, and the sulfur content is 24% by weight; The tacky roll V200 is mentioned.

Because a vulcanized rubber composition of high hardness (Hs) can be obtained as a vulcanization acceleration assistant (reversion suppression), formula (V):
HO ₃ S-S- (CH ₂ ) _k -S-SO ₃ H (V)
[Wherein, k is an integer of 3 to 10. ]
It is preferable to use a salt of an organic thiosulfate compound represented by (hereinafter sometimes referred to as “organic thiosulfate compound salt (V)”). Organic thiosulfate compound salt (V) containing crystal water may be used. Examples of organic thiosulfate compound salts (V) include lithium salts, potassium salts, sodium salts, magnesium salts, calcium salts, barium salts, zinc salts, nickel salts, cobalt salts and the like, and potassium salts and sodium salts Is preferred.

K is an integer of 3 to 10, preferably an integer of 3 to 6. When k is 2 or less, sufficient thermal fatigue resistance tends not to be obtained, and when k is 11 or more, the improvement effect of thermal fatigue resistance by organic thiosulfate compound salt (V) may not be sufficiently obtained. .

As the organic thiosulfate compound salt (V), from the viewpoint of being stable at normal temperature and pressure, its sodium salt monohydrate and sodium salt dihydrate are preferable, and they can be obtained from sodium thiosulfate from the viewpoint of cost Organic thiosulfate compound salt (V) is more preferable, and sodium 1,6-hexamethylenedithiosulfate dihydrate represented by the following formula is more preferable.

Good dispersion in rubber component with olefinic double bond, insertion in the middle of -S _X -crosslinking of alkylphenol sulfur chloride condensate (IV) when used in combination with alkylphenol sulfur chloride condensate (IV) Because it is possible to form a hybrid bridge with the alkylphenol-sulfur chloride condensate (IV), formula (III):
R ¹⁶ -S-S-R ¹⁷ -S-S-R ¹⁸ (III)
(Wherein, R ¹⁷ represents a C _2-10 alkanediyl group, and R ¹⁶ and R ¹⁸ each independently represent a monovalent organic group containing a nitrogen atom).
It is preferable to use the compound represented by the above as an accelerator for promoting vulcanization together with the alkylphenol-sulfur chloride condensate (IV).

R ¹⁷ is a C _2-10 alkanediyl group, preferably a C _4-8 alkanediyl group, more preferably a linear C _4-8 alkanediyl group. R ¹⁷ is preferably linear. If the carbon number of R ¹⁷ is 1 or less, the thermal stability may be poor. In addition, when the carbon number of R ¹⁷ is 11 or more, the distance between the polymers via the vulcanization acceleration auxiliary may be long, and the effect of adding the vulcanization acceleration auxiliary may not be obtained.

R ¹⁶ and R ¹⁸ are each independently a monovalent organic group containing a nitrogen atom. The monovalent organic group containing a nitrogen atom is preferably one containing at least one aromatic ring, and more preferably one containing an aromatic ring and NN—C (= S) — group (thiocarbamoyl group). R ¹⁶ and R ¹⁸ may be the same as or different from each other, but are preferably the same for reasons of easiness of production and the like.

As compound (III), for example, 1,2-bis (dibenzylthiocarbamoyldithio) ethane, 1,3-bis (dibenzylthiocarbamoyldithio) propane, 1,4-bis (dibenzylthiocarbamoyldithio) butane 1,5-bis (dibenzylthiocarbamoyldithio) pentane, 1,6-bis (dibenzylthiocarbamoyldithio) hexane, 1,7-bis (dibenzylthiocarbamoyldithio) heptane, 1,8-bis (dibenzylthiocarbamoyldithio) heptane Examples include benzylthiocarbamoyldithio) octane, 1,9-bis (dibenzylthiocarbamoyldithio) nonane, 1,10-bis (dibenzylthiocarbamoyldithio) decane and the like. Among them, 1,6-bis (dibenzylthiocarbamoyldithio) hexane is preferable because it is thermally stable and excellent in dispersibility in a rubber component having an olefinic double bond.

Examples of commercially available products of compound (III) include VULCUREN TRIAL PRODUCT KA 9188 and VULCUREN VP KA 9188 (1, 6-bis (dibenzylthiocarbamoyldithio) hexane) manufactured by Bayer.

In the present invention, an organic compound such as resorcinol, resorcinol resin, modified resorcinol resin, cresol resin, modified cresol resin, phenolic resin, and modified phenolic resin may be used. By using resorcinol or these resins, the elongation at break and the complex elastic modulus of the vulcanized rubber composition can be improved. Moreover, when using a rubber composition for manufacture of a rubber product which contacts cords, adhesiveness with a cord can be improved by using resorcinol and resin.

Examples of resorcinol include resorcinol manufactured by Sumitomo Chemical Co., Ltd. Examples of resorcinol resins include resorcinol-formaldehyde condensates. Examples of the modified resorcinol resin include those obtained by alkylating part of the repeating unit of resorcinol resin. Specifically, Penacolite resin B-18-S and B-20 manufactured by India Spec Co., Ltd., Sumikanol 620 manufactured by Taoka Chemical Industry Co., Ltd., R-6 manufactured by Uniroyal Co., Ltd., SRF 1501 manufactured by Schenectady Chemical Co., and Ash Examples include Arofene 7209 manufactured by Land Corporation.

Examples of cresol resins include cresol-formaldehyde condensates. Examples of the modified cresol resin include one in which the terminal methyl group of cresol resin is changed to a hydroxy group, and one in which a part of the repeating unit of cresol resin is alkylated. Specifically, Sumikanol 610 manufactured by Taoka Chemical Industry Co., Ltd., PR-X11061 manufactured by Sumitomo Bakelite Co., Ltd., etc. may be mentioned.

As a phenol resin, a phenol formaldehyde condensate is mentioned, for example. Further, examples of the modified phenolic resin include resins in which a phenolic resin is modified using cashew oil, tall oil, linseed oil, various animal and vegetable oils, unsaturated fatty acids, rosin, alkylbenzene resins, aniline, melamine and the like.

As other resins, for example, methoxylated methylol melamine resin such as "Sumikanol 507AP" manufactured by Sumitomo Chemical Co., Ltd .; Coumaron resin NG4 (softening point: 81 to 100 ° C.) manufactured by Nittetsu Chemical Co., Ltd .; Coumarone-indene resin such as “process resin AC5” (softening point 75 ° C.); terpene resin such as terpene resin, terpene / phenol resin, aromatic modified terpene resin; “Nicanol (registered trademark) A70” manufactured by Mitsubishi Gas Chemical Co. Rosin derivatives having a softening point of 70 to 90 ° C .; hydrogenated rosin derivatives; novolak type alkylphenol resins; resol type alkylphenol resins; C5 petroleum resins; liquid polybutadiene.

As the anti-aging agent, for example, those described on pages 436 to 443 of “Rubber Industry Handbook <Fourth Edition>” edited by The Japan Rubber Association are mentioned. As an antiaging agent, N-phenyl-N'-1,3-dimethylbutyl-p-phenylenediamine (abbreviated "6PPD", for example, "Antigen (registered trademark) 6C" manufactured by Sumitomo Chemical Co., Ltd.), reaction of aniline with acetone Product (abbreviated "TMDQ"), poly (2,2,4-trimethyl-1,2-) dihydroquinoline (eg, "Antioxidant FR" manufactured by Matsubara Sangyo Co., Ltd.), synthetic wax (paraffin wax etc.), plant Waxes are preferably used.

When an antioxidant is used, the amount thereof used is preferably 0.01 to 15 parts by weight, more preferably 0.1 to 10 parts by weight based on 100 parts by weight of the rubber component having an olefinic double bond. Parts by weight, more preferably 0.1 to 5 parts by weight.

Examples of the oil include process oil, vegetable oil and the like. Examples of process oils include paraffinic process oils, naphthenic process oils, and aromatic process oils. Examples of commercially available products include aromatic oils ("NC-140" manufactured by Cosmo Oil Co., Ltd.) and process oils ("Diana Process PS32" manufactured by Idemitsu Kosan Co., Ltd.).

Examples of the wax include "Sanknock (registered trademark) wax" manufactured by Ouchi Emerging Chemical Industry Co., Ltd., "OZOACE-0355" manufactured by Nippon Seiwa Co., Ltd., and the like.

The peptizing agent is not particularly limited as long as it is commonly used in the rubber field, and is described, for example, on pages 446 to 449 of "Rubber Industry Handbook <Fourth Edition>" edited by The Japan Rubber Association. And aromatic mercaptan-type peptizers, aromatic disulfide-type peptizers and aromatic mercaptan metal salt-type peptizers. Among them, dixylyl disulfide and o, o'-dibenzamidodiphenyl disulfide ("NOCTIZER SS" manufactured by Ouchi Shinko Chemical Co., Ltd.) are preferable. The peptizing agent may be used alone or in combination of two or more.

Examples of retarders include phthalic anhydride, benzoic acid, salicylic acid, N-nitrosodiphenylamine, N- (cyclohexylthio) phthalimide (CTP), sulfonamide derivatives, diphenylurea, bis (tridecyl) pentaerythritol diphosphite and the like. (Cyclohexylthio) phthalimide (CTP) is preferably used.

In the present invention, the formula: —O— (CH ₂ —CH ₂ —O) _q —H [wherein, q is an integer of 1 or more. The compound which has an oxyethylene unit which has a structure represented by these may be used. Here, in the above formula, q is preferably 2 or more, and more preferably 3 or more. Moreover, 16 or less is preferable and 14 or less of q is more preferable. When q is 17 or more, the compatibility and reinforcement with the rubber component having an olefinic double bond tend to be lowered.

The position of the oxyethylene unit in the compound having an oxyethylene unit may be a main chain, an end, or a side chain. Among the compounds having an oxyethylene unit, a compound having an oxyethylene unit at least in a side chain is preferable from the viewpoint of durability of the effect of preventing accumulation of static electricity on the tire surface to be obtained and reduction of electrical resistance.

Examples of compounds having an oxyethylene unit in the main chain include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, monoethylene glycol, diethylene glycol, triethylene glycol, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene polyoxypropylene Alkyl ethers, polyoxyethylene alkylamines, polyoxyethylene styrenated alkyl ethers, polyoxyethylene alkylamides and the like can be mentioned.

When a compound having an oxyethylene unit at least in the side chain is used, the number of oxyethylene units is preferably 4 or more per 100 carbon atoms constituting the main chain, and more preferably 8 or more. When the number of oxyethylene units is 3 or less, the electrical resistance tends to increase. Moreover, 12 or less is preferable and, as for the number of objects of an oxyethylene unit, 10 or less are more preferable. When the number of oxyethylene units is 13 or more, the compatibility and reinforcement with the rubber component having an olefinic double bond tend to be lowered.

The main chain of the compound having an oxyethylene unit at least in the side chain is preferably one composed mainly of polyethylene, polypropylene or polystyrene.

<Manufacturing method>
(1) Method of producing rubber composition and rubber composition containing sulfur The method of producing the rubber composition of the present invention comprises compound (C), a rubber component having an olefinic double bond, and silica. A process of obtaining a kneaded product, and a process of kneading the obtained kneaded product and a compound having a Si-O bond capable of binding to silica to obtain a rubber composition. .

In the present invention, it is presumed that the compound (C) (particularly, the compound (I) and the compound (II)) has an effect of reducing the loss coefficient (tan δ) of the vulcanized rubber composition. However, as shown in a comparative example described later, compound (C), a rubber component having an olefinic double bond, silica, and a compound having a Si-O bond capable of binding to silica are kneaded at once. A rubber composition is prepared, and the obtained rubber composition and the sulfur component are kneaded to prepare a rubber composition containing the sulfur component, and the obtained rubber composition containing the sulfur component is vulcanized. The present inventors have found a problem that the loss coefficient of the obtained vulcanized rubber composition is not much reduced as compared to the loss coefficient of the vulcanized rubber composition obtained without using the compound (C).

As a result of intensive investigations conducted by the present inventor, first, compound (C), a rubber component having an olefinic double bond, and silica are kneaded to prepare a kneaded product (step 1), and then obtained. By kneading the mixture and the compound having a Si-O bond capable of binding to silica to prepare a rubber composition (Step 2), the loss factor is sufficient as shown in the examples described later. It has been found that a vulcanized rubber composition is obtained which is reduced.

From the viewpoint of reducing the loss coefficient (tan δ) of the vulcanized rubber composition, it is preferable to knead all of the amount of the compound (C) used in the present invention in step 1. However, a part of the used amount of the compound (C) in the present invention may be kneaded in Step 2 as long as the effects of the present invention are not significantly impaired. The amount of compound (C) to be kneaded in step 2 is preferably 0 to 25% by weight, more preferably 0 to 10% by weight, based on the amount used in the present invention.

From the viewpoint of reducing the loss coefficient (tan δ) of the vulcanized rubber composition, it is preferable to knead in step 1 the entire amount of the rubber component having an olefinic double bond in the present invention. However, a part of the used amount of the rubber component having an olefinic double bond in the present invention may be kneaded in Step 2 within a range not significantly impairing the effects of the present invention. The amount of the rubber component having an olefinic double bond to be kneaded in Step 2 is preferably 0 to 50% by weight, more preferably 0 to 40% by weight in the amount used in the present invention.

From the viewpoint of reducing the loss coefficient (tan δ) of the vulcanized rubber composition, it is preferable to knead all of the amount of silica used in the present invention in step 1. However, a part of the amount of silica used in the present invention may be kneaded in Step 2 as long as the effects of the present invention are not significantly impaired. The amount of silica to be kneaded in step 2 is preferably 0 to 75% by weight, more preferably 0 to 25% by weight, based on the amount used in the present invention.

From the viewpoint of reducing the loss coefficient (tan δ) of the vulcanized rubber composition, it is preferable to knead in step 2 the entire amount of the compound having a Si—O bond that can be bonded to silica in the present invention. However, a part of the used amount of the compound having a Si—O bond that can be bonded to the silica in the present invention may be kneaded in Step 1 within a range that does not significantly impair the effects of the present invention. The amount of the compound having a Si—O bond capable of binding to the silica to be kneaded in Step 1 is preferably 0 to 25% by weight, more preferably 0 to 10% by weight in the amount used in the present invention.

In the present invention, in order to facilitate processing of the rubber component having an olefinic double bond, a preliminary kneading step of masticating the rubber component may be provided prior to step 1. When a peptizing agent is used, it is preferable to knead all of the amount used in the present invention in the pre-kneading step, or knead a portion of the used amount in the pre-kneading step, and knead the rest in step 1 .

In the present invention, the sulfur component is kneaded with the rubber composition obtained in step 2. In the following, the process of kneading the rubber composition and the sulfur component may be described as a pro process. When a vulcanization accelerator is used, it is preferable to knead all of its use amount in the pro step. Moreover, when using a retarder, it is preferable to knead | mix all of the usage-amount at a pro process.

The other components (e.g., stearic acid, zinc oxide, anti-aging agent) other than the vulcanization accelerator, the peptizer and the retarder may be kneaded in any of the pre-kneading step, step 1 and step 2. However, in order to cause compound (C) to sufficiently react or interact with the rubber component having an olefinic double bond and silica during kneading to sufficiently exhibit the loss coefficient reduction effect of compound (C), It is preferable to knead | mix in step 2 all the usage-amount of other components except a vulcanization accelerator, a peptizer, and a retarder.
Hereinafter, the pre-kneading step, step 1, step 2 and pro step will be described in order.

(A) Pre-kneading step As described above, in the method of the present invention, a pre-kneading step of masticating a rubber component having an olefinic double bond may be performed prior to step 1. For mastication in the pre-kneading step, for example, an internal mixer including a Banbury mixer, an open kneader, a pressure kneader, an extruder, an injection molding machine, and the like can be used.

The rotational speed for mastication in the pre-kneading step is preferably 5 to 100 rpm, more preferably 10 to 80 rpm, and still more preferably 10 to 60 rpm. The kneading time for mastication is preferably 0.5 to 15 minutes, more preferably 1 to 10 minutes, and still more preferably 1 to 4 minutes.

(B) Step 1
Compound (C) in step 1, rubber component having an olefinic double bond, and kneading of silica, or compound in step 1, rubber component having an olefinic double bond, silica, and optionally other components For kneading (which may be abbreviated as “kneading in step 1” in this specification), for example, an internal mixer including a Banbury mixer, an open kneader, a pressure kneader, an extruder, an injection molding machine, etc. It can be used.

Steps 1 and 2 in the present invention can be performed, for example, as in the following (i) or (ii):
(I) After step 1, the kneaded material is discharged from the apparatus used in step 1, cooled, and then the obtained kneaded material, a compound having a Si-O bond capable of binding to silica, and, if necessary, The other components are introduced into the apparatus used in step 2 and kneading in step 2 is performed.
(Ii) After step 1, without discharging the kneaded material from the apparatus used in step 1, the apparatus is charged with a compound having a Si-O bond capable of binding to silica, and other components as needed. Then, the kneading of step 2 is performed following the kneading of step 1.
From the viewpoint of operation, the aspect of the above (i) is preferable.

In any of the embodiments (i) and (ii), it is preferable to perform the kneading in step 2 after the kneading in step 1 is sufficiently performed. It can be judged from the change of the torque of the apparatus used at the process 1 whether the kneading | mixing of the process 1 was fully performed. Specifically, while the kneading is insufficient, the torque of the device increases, and then the torque of the device decreases. It is preferable to carry out the kneading of step 1 for a time longer than the time for which the torque of the device is reduced (for example, the time until 1 to 5 minutes have elapsed after the torque of the device is reduced).

The kneading in step 1 may be performed by changing the rotation speed. For example, first, kneading may be performed at a low first rotational speed, and then may be performed at a second rotational speed higher than the first rotational speed. The first rotation speed is preferably 2 to 35 rpm, more preferably 4 to 25 pm, still more preferably 6 to 15 rpm, and the kneading time is preferably 0.5 to 5 minutes, more preferably 0.5 to 5 minutes. 3 minutes, preferably 0.5 to 2 minutes. The second rotation speed is preferably 35 to 100 rpm, more preferably 40 to 90 pm, still more preferably 45 to 80 rpm, and the kneading time is preferably 1 to 10 minutes, more preferably 1.5 to 8 minutes. More preferably, it is 2 to 6 minutes.

When the kneaded material is discharged from the apparatus used in step 1 as in the embodiment of the above (i), the discharge temperature of the kneaded material is preferably 120 to 180 ° C., more preferably 130 to 170 ° C., still more preferably 140. It is ~ 160 ° C.

(C) Cooling step As described above, in the method of the present invention, after step 1, the kneaded material may be discharged from the apparatus used in step 1, and the kneaded material may be cooled. Examples of the cooling operation from the apparatus used in Step 1 include cold cooling, water cooling, and forced air cooling. Among these, simple free standing is preferred.

In order to promote cooling (in particular, cooling), the kneaded material obtained in Step 1 may be processed into a sheet or a board using an open roll. The thickness of the kneaded material processed into a sheet or board is preferably 0.5 to 20 mm, more preferably 2 to 10 mm.

(D) Process 2
Kneading the above-mentioned kneaded product in step 2 and a compound having a Si-O bond capable of binding to silica, or the above-mentioned kneaded product in step 2, a compound having a Si-O bond capable of binding to silica and optionally other components (Sometimes abbreviated as “kneading in step 2” in the present specification), for example, an internal mixer including a Banbury mixer, an open kneader, a pressure kneader, an extruder, an injection molding machine, etc. Can be used.

The apparatus set temperature at the start of kneading in step 2 is preferably 40 to 200 ° C., more preferably 50 to 180 ° C., and still more preferably 60 to 160 ° C.

When the cooling step is performed, it is preferable to knead only the kneaded material first in order to shear the rubber component in the kneaded material after cooling. The rotational speed of kneading of this kneaded material alone is preferably 35 to 100 rpm, more preferably 40 to 90 pm, still more preferably 45 to 80 rpm, and the kneading time is preferably 0.5 to 10 minutes, more preferably 1 to 8 minutes, more preferably 2 to 5 minutes.

The kneading in step 2 may be performed by changing the rotation speed. For example, first, kneading may be performed at a low first rotational speed, and then may be performed at a second rotational speed higher than the first rotational speed. The first rotation speed is preferably 2 to 35 rpm, more preferably 4 to 25 pm, still more preferably 6 to 15 rpm, and the kneading time is preferably 0.5 to 5 minutes, more preferably 0.5 to 5 minutes. 3 minutes, preferably 0.5 to 2 minutes. The second rotation speed is preferably 35 to 100 rpm, more preferably 40 to 90 pm, still more preferably 45 to 80 rpm, and the kneading time is preferably 1 to 10 minutes, more preferably 1.5 to 8 minutes. More preferably, it is 2 to 6 minutes.

In the present invention, the rubber composition obtained in step 2 is discharged from the apparatus used in step 2, and the obtained rubber composition and the sulfur component are kneaded using an apparatus different from step 2 It is preferred to carry out the pro step. The discharge temperature of the rubber composition from the apparatus used in step 2 is preferably 80 to 200 ° C., more preferably 90 to 190 ° C., still more preferably 100 to 180 ° C.

(E) Pro process In the kneading of the rubber composition obtained as described above and the sulfur component, for example, an open roll, a calendar or the like can be used. The kneading temperature (temperature of the rubber composition being kneaded) in the pro step is preferably 20 to 100 ° C., more preferably 30 to 90 ° C., and still more preferably 40 to 80 ° C.

(2) Method of producing a vulcanized rubber composition A vulcanized rubber composition can be produced by vulcanizing a rubber composition containing a sulfur component. The vulcanization temperature is preferably 120 to 180.degree. Those skilled in the art can appropriately set the vulcanization time according to the composition of the rubber composition. Vulcanization is usually carried out under normal pressure or under pressure.

<Rubber composition, rubber composition containing sulfur component and vulcanized rubber composition>
The present invention also provides a rubber composition, a rubber composition containing a sulfur component, and a vulcanized rubber composition obtained by the method described above.

As shown in the following Examples and Comparative Examples, the loss coefficient (tan δ) of the vulcanized rubber composition obtained by the method of the present invention including Step 1 and Step 2 is the compound (C) and the olefinic difunctional compound Obtained by a method including a step of kneading the rubber component having a heavy bond, silica, and a compound having a Si-O bond capable of binding to silica at one time (hereinafter sometimes abbreviated as "other method"). Very low compared to the loss factor of the vulcanized rubber composition. Therefore, the rubber composition obtained by the method of the present invention, the rubber composition containing a sulfur component and the vulcanized rubber composition are the rubber composition obtained by another method, the rubber composition containing a sulfur component and It is clear that the composition is different from the vulcanized rubber composition.

However, it is necessary to distinguish between the rubber composition etc. obtained by the method of the present invention and the rubber composition etc obtained by other methods in which only the operation is different and the components used are the same. Impossible or not nearly practical. In other words, in the present technology of analyzing a solid rubber composition, it is impossible or almost not practical to directly identify the rubber composition etc. obtained by the method of the present invention by its structure etc. . Therefore, in the present specification and claims, the rubber composition of the present invention, the rubber composition containing a sulfur component and the vulcanized rubber composition are specified by the method of the present invention.

EXAMPLES Hereinafter, the present invention will be more specifically described by way of examples and the like. However, the present invention is not limited by the following examples, and appropriate modifications may be made as long as it can conform to the above It is of course also possible to carry out the present invention, and all of them are included in the technical scope of the present invention. In addition, "part" as described in the following Example etc. means a "weight part."

<Component>
The components and abbreviations used in the following examples are as follows.
・ NR: Natural rubber (RSS # 1)
SBR: solution-polymerized styrene / butadiene copolymer rubber (Sumitomo Chemical Co., Ltd., trade name "SE-0212")
· BR: Polybutadiene rubber (manufactured by JSR, trade name "BR01")
Silica (Tosoh Silica Corporation, trade name “Nipsil (registered trademark) AQ”, BET specific surface area: 190 m ² / g)
-CB: carbon black ISAF (manufactured by Asahi Carbon Co., Ltd., trade name "Asahi # 80", BET specific surface area: 115 m ² / g)
Compound (Ia-1): (2Z) -4-[(4-aminophenyl) amino] -4-oxo-2-butenoate sodium dihydrate Compound (II-1): S- (3) -Aminopropyl) thiosulfuric acid / silane coupling agent (bis (3-triethoxysilylpropyl) disulfide, manufactured by Degussa, trade name "Si-75")
・ Zinc oxide (ZnO)
・ Stearic acid (manufactured by Kao Corporation, trade name "Lunack S20")
Anti-aging agent: N-phenyl-N'-1,3-dimethylbutyl-p-phenylenediamine (manufactured by Sumitomo Chemical Co., Ltd., trade name "Antigen (registered trademark) 6C")
-Sulfur component: Powdered sulfur (S ₈ )
Vulcanization accelerator 1: N-cyclohexyl-2-benzothiazolylsulfenamide (CBS)
Vulcanization accelerator 2: diphenyl guanidine (DPG)

<Reference Examples 1 and 2, Examples 1 to 12, and Comparative Examples 1 and 2>
The rubber compositions of Reference Examples 1 and 2, Examples 1 to 12, and Comparative Examples 1 and 2, the rubber composition containing a sulfur component, and the vulcanized rubber composition were produced as follows.

Pre-kneading step and step 1 (Reference Example 2, Examples 1 to 12, and Comparative Examples 1 and 2)
Natural rubber was charged into a pressure-type kneader (TD1-5MDX manufactured by Toshin Co., Ltd.) whose temperature at the start of kneading was set to 140 ° C., and then two-component kneading was performed at a rotation number of 50 rpm. The components other than natural rubber are added thereto in the amount shown in step 1 of the following table, and kneading is performed for 2 minutes at 10 rpm, and then kneading is performed for 3 minutes at 50 rpm, Drained. The time until the torque of the device is reduced after the addition of components other than natural rubber is about 2.5 minutes, and after the torque of the device is reduced, kneading for 2.5 minutes is further performed at 50 rpm. went. Moreover, the discharge temperature of the kneaded material of the process 1 was about 150 degreeC.

Cooling step (Reference Example 2, Examples 1 to 12, and Comparative Examples 1 and 2)
The kneaded product obtained in step 1 is processed into a sheet having a thickness of 3 to 5 mm using an open roll (laboratory mill manufactured by Kansai Roll Co., Ltd.) at a set temperature of 50 ° C., and then room temperature until it reaches room temperature The sheet-like kneaded material was allowed to cool under the atmosphere atmosphere.

Step 2
The kneaded product after the above-mentioned cooling step (described as "kneaded product" in the following table) is put into a pressure type kneader (TD1-5MDX manufactured by Toshin Co., Ltd.) whose temperature at the start of kneading is set to 140 ° C. After applying shear for 1 minute at 50 rpm, add the components of the types and amounts shown in the following table, and perform kneading for 3 minutes at 50 rpm and 2 minutes at 10 rpm. The composition was obtained. The discharge temperature of the rubber composition was about 150 ° C.

The rubber composition obtained in step 2 is mixed with the sulfur component of the amount shown in the following table and the vulcanization accelerators 1 and 2 at a temperature of 60 to 80 ° C. in a pro step open roll to contain the sulfur component The resulting rubber composition was obtained.

Vulcanization process Using a vulcanization press, the vulcanization temperature is set to 145 ° C., and the vulcanization time is 10 minutes to the value of t (90) obtained by rheometer measurement according to JIS K 6300-2. The vulcanized rubber composition was obtained by vulcanizing the rubber composition obtained in the pro step by setting the time for adding.

As shown in the following table, in Reference Examples 1 and 2, the compound (Ia-1) and the compound (II-1) were not used.
In Comparative Example 1, a silane coupling agent was kneaded instead of compound (Ia-1) and compound (II-1) in step 1.
In Comparative Example 2, the silica was not kneaded in Step 1.

As shown in the following table, in Reference Example 1, the rubber composition was manufactured by kneading the components other than the sulfur component and the vulcanization accelerators 1 and 2 in the above step 2 without performing the above step 1. Specifically, 100 parts by weight of natural rubber is introduced into a pressure type kneader (TD1-5MDX manufactured by Toshin Co., Ltd.) whose temperature at the start of kneading is set to 140 ° C., and the rotation speed is 50 rpm for 2 minutes After shearing, components of the types and amounts shown in the following table were charged, and kneading was performed at 10 rpm for 2 minutes and further at 50 rpm for 3 minutes to obtain a rubber composition. The discharge temperature of the rubber composition was about 150 ° C.

Calculation of the relative value of tan δ Under the following conditions, the visco-elastic properties of the vulcanized rubber compositions obtained in Examples, Comparative Examples and Reference Examples are measured using a visco-elastic analyzer manufactured by Uejima Mfg. Co., Ltd. The loss factor (tan δ) at 60 ° C. was determined.
Measurement temperature: 60 ° C
Initial strain: 10%
Dynamic strain: 2.5%
Frequency: 10Hz

In Reference Examples 1 and 2 and Examples 1 to 12 and Comparative Examples 1 and 2, relative values of tan δ were calculated based on tan δ of the vulcanized rubber composition of Reference Example 2. Specifically, tan δ of the vulcanized rubber composition measured as described above is used, and the following formula:
Relative value of tan δ = 100 × (tan δ of vulcanized rubber composition) / (tan δ of vulcanized rubber composition of Reference Example 2)
The relative value of tan δ was calculated from The results are shown in the following table.

As shown in the above table, in Examples 1 to 12 satisfying the requirements of the present invention, relative values of tan δ are compared with those of Reference Examples 1 and 2 in which Compound (Ia-1) and Compound (II-1) are not used. Significantly reduced. On the other hand, in Comparative Example 1 in which a silane coupling agent was used instead of the compound (Ia-1) and the compound (II-1), the relative value of tan δ was increased compared to Reference Examples 1 and 2. Further, in Comparative Example 2 in which natural rubber and compound (Ia-1) were kneaded in Step 1 but silica was not kneaded, the relative value of tan δ was equivalent to that of Reference Examples 1 and 2.

As shown in the above table, Examples 7 to 9 in which a part of the silica is kneaded in Step 2 and Examples 10 to 12 in which a part of the natural rubber is kneaded in Step 2 are all of the silica and the natural rubber. A vulcanized rubber composition having a sufficiently reduced loss factor (tan δ) was obtained in the same manner as in Examples 1 to 6 in which kneading was carried out in step 1.

From the above results, it is possible to knead compound (C) (= compound (Ia-1) or compound (II-1)), a rubber component having an olefinic double bond (= natural rubber), and silica, Preparing a rubber composition by preparing a kneaded product (Step 1), and then kneading the obtained kneaded product and a compound (= silane coupling agent) having a Si-O bond capable of binding to silica (Step 2) shows that a vulcanized rubber composition having a sufficiently reduced loss factor can be obtained.

<Reference Examples 3 and 4, Example 13 and Comparative Example 3>
The rubbers of Reference Examples 3 and 4, Example 13, and Comparative Example 3 are the same as Example 1 etc. except that natural rubber and solution-polymerized styrene / butadiene copolymer rubber were used in addition to natural rubber. The composition, a rubber composition containing a sulfur component, and a vulcanized rubber composition were produced, and the loss coefficient (tan δ) at 60 ° C. of the vulcanized rubber composition was measured. The types and amounts of ingredients used are shown in the following table.

As shown in the following table, in Reference Examples 3 and 4, the compound (Ia-1) was not used.
Further, in Reference Example 3 and Comparative Example 3, the rubber composition was manufactured by kneading the components other than the sulfur component and the vulcanization accelerators 1 and 2 in the above step 2 without performing the above step 1. Specifically, rubber components of the types and amounts shown in the following table are charged into a pressure type kneader (TD1-5MDX manufactured by Toshin Co., Ltd.) whose temperature at the start of kneading is set to 140 ° C., and the rotation number is 50 rpm. After shearing for 2 minutes, other components of the types and amounts shown in the following table are added, and kneading is performed for 2 minutes at 10 rpm and further for 3 minutes at 50 rpm to obtain a rubber composition. Obtained. The discharge temperature of the rubber composition was about 150 ° C.

In Reference Examples 3 and 4, Example 13, and Comparative Example 3, the relative value of tan δ was calculated based on tan δ of the vulcanized rubber composition of Reference Example 3. Specifically, tan δ of the vulcanized rubber composition measured as described above is used, and the following formula:
Relative value of tan δ = 100 × (tan δ of vulcanized rubber composition) / (tan δ of vulcanized rubber composition of Reference Example 3)
The relative value of tan δ was calculated from The results are shown in the following table.

As shown in the above table, even when natural rubber and solution-polymerized styrene / butadiene copolymer rubber are used as rubber components, in Example 13 satisfying the requirements of the present invention, the loss coefficient (tan δ) is sufficiently reduced. A vulcanized rubber composition was obtained.

From the comparison between Example 13 and Comparative Example 3, a compound (C) (= compound (Ia-1)) and a rubber component having an olefinic double bond (= natural rubber and solution-polymerized styrene / butadiene copolymer rubber) Compared to the case where rubber composition is manufactured by kneading at once, silica and a compound having Si-O bond that can bond to silica (= silane coupling agent), these are divided into steps 1 and 2 It is shown that the present invention of kneading and kneading gives a vulcanized rubber composition having a sufficiently reduced loss factor.

Reference Examples 5 and 6, Example 14, and Comparative Example 4
The rubber compositions of Reference Examples 5 and 6, Example 14, and Comparative Example 4 in the same manner as in Example 1 and the like except that natural rubber and polybutadiene rubber were used in addition to natural rubber, and sulfur components The contained rubber composition and the vulcanized rubber composition were manufactured, and the loss factor (tan δ) at 60 ° C. of the vulcanized rubber composition was measured. The types and amounts of ingredients used are shown in the following table.

As shown in the following table, in Reference Examples 5 and 6, the compound (Ia-1) was not used.
Further, in Reference Example 5 and Comparative Example 4, the rubber composition was manufactured by kneading the components other than the sulfur component and the vulcanization accelerators 1 and 2 in the above step 2 without performing the above step 1. Specifically, rubber components of the types and amounts shown in the following table are charged into a pressure type kneader (TD1-5MDX manufactured by Toshin Co., Ltd.) whose temperature at the start of kneading is set to 140 ° C., and the rotation number is 50 rpm. After shearing for 2 minutes, other components of the types and amounts shown in the following table are added, and kneading is performed for 2 minutes at 10 rpm and further for 3 minutes at 50 rpm to obtain a rubber composition. Obtained. The discharge temperature of the rubber composition was about 150 ° C.

In Reference Examples 5 and 6, Example 14, and Comparative Example 4, the relative value of tan δ was calculated based on tan δ of the vulcanized rubber composition of Reference Example 5. Specifically, tan δ of the vulcanized rubber composition measured as described above is used, and the following formula:
Relative value of tan δ = 100 × (tan δ of vulcanized rubber composition) / (tan δ of vulcanized rubber composition of Reference Example 5)
The relative value of tan δ was calculated from The results are shown in the following table.

As shown in the above table, even when natural rubber and polybutadiene rubber are used as the rubber component, Example 14 satisfying the requirements of the present invention provides a vulcanized rubber composition in which the loss coefficient (tan δ) is sufficiently reduced. It was done.

From the comparison between Example 14 and Comparative Example 4, compound (C) (= compound (Ia-1)), rubber component having olefinic double bond (= natural rubber and polybutadiene rubber), silica, silica And the compound having a bondable Si-O bond (= silane coupling agent) are kneaded at one time to produce a rubber composition, these are divided into steps 1 and 2 according to the present invention. It is shown that a vulcanized rubber composition having a sufficiently reduced loss factor can be obtained.

Reference Examples 7 and 8, Example 15, and Comparative Example 5
Reference Examples 7 and 8, Example 15, and Comparative Examples are carried out in the same manner as Example 1 etc. except that natural rubber, solution-polymerized styrene / butadiene copolymer rubber and polybutadiene rubber are used in addition to natural rubber. The rubber composition of No. 5, the rubber composition containing a sulfur component, and the vulcanized rubber composition were produced, and the loss coefficient (tan δ) at 60 ° C. of the vulcanized rubber composition was measured. The types and amounts of ingredients used are shown in the following table.

As shown in the following table, in Reference Examples 7 and 8, the compound (Ia-1) was not used.
Further, in Reference Example 7 and Comparative Example 5, a rubber composition was manufactured by kneading the components other than the sulfur component and the vulcanization accelerators 1 and 2 in the above step 2 without performing the above step 1. Specifically, rubber components of the types and amounts shown in the following table are charged into a pressure type kneader (TD1-5MDX manufactured by Toshin Co., Ltd.) whose temperature at the start of kneading is set to 140 ° C., and the rotation number is 50 rpm. After shearing for 2 minutes, other components of the types and amounts shown in the following table are added, and kneading is performed for 2 minutes at 10 rpm and further for 3 minutes at 50 rpm to obtain a rubber composition. Obtained. The discharge temperature of the rubber composition was about 150 ° C.

In Reference Examples 7 and 8, Example 15, and Comparative Example 5, the relative value of tan δ was calculated based on the tan δ of the vulcanized rubber composition of Reference Example 7. Specifically, tan δ of the vulcanized rubber composition measured as described above is used, and the following formula:
Relative value of tan δ = 100 × (tan δ of vulcanized rubber composition) / (tan δ of vulcanized rubber composition of Reference Example 7)
The relative value of tan δ was calculated from The results are shown in the following table.

As shown in the above table, even when natural rubber, solution-polymerized styrene / butadiene copolymer rubber and polybutadiene rubber are used as rubber components, the loss coefficient (tan δ) is sufficiently reduced in Example 15 satisfying the requirements of the present invention. The resulting vulcanized rubber composition was obtained.

From the comparison between Example 15 and Comparative Example 5, a compound (C) (= compound (Ia-1)) and a rubber component having an olefinic double bond (= natural rubber, solution-polymerized styrene / butadiene copolymer rubber, and Steps 1 and 2 compared to the case where a rubber composition is prepared by kneading a polybutadiene rubber), silica, and a compound having an Si—O bond capable of binding to silica (= silane coupling agent) at once. It is shown that the present invention, in which the composition is divided and kneaded, provides a vulcanized rubber composition having a sufficiently reduced loss factor.

According to the method of the present invention, a vulcanized rubber composition having a low loss factor can be produced. The rubber composition obtained by the method of the present invention is useful for the production of various products (for example, vulcanized tires and tire components).

This application is based on patent application No. 2017-155364 filed in Japan, the contents of which are incorporated in full herein.

Claims

Compound (C) having a group or structure (A) capable of reacting with an olefinic double bond, and a group or structure (B) capable of reacting or interacting with silica, and having no Si-O bond, and an olefin Step 1: Kneading a rubber component having an anionic double bond and silica to obtain a kneaded product, and kneading the obtained kneaded product and a compound having a Si-O bond capable of binding to silica, Step 2 of obtaining a rubber composition
A method of producing a rubber composition comprising:
The compound (C) is a compound of formula (I):

[In the formula (I),
R 1 is a C 2-12 alkanediyl group which may have one or more substituents, a C 3-10 cycloalkanediyl group which may have one or more substituents, one or more substituents And a divalent C 6-12 aromatic hydrocarbon group which may have the formula, or a combination thereof.
R 2 and R 3 each independently have a hydrogen atom, a halogen atom, a hydroxy group, a C 1-6 alkoxy group optionally having one or more substituents, or one or more substituents or represents a C 1-6 alkyl group or one or more may have a substituent group C 6-14 aryl group, or R 2 and R 3 are bonded, the carbon atom to which they are attached Taken together, form a C 3-10 cycloalkene diyl group which may have one or more substituents.
R 4 is a hydroxy group, a C 1-6 alkoxy group which may have one or more substituents, a C 6-14 aryloxy group which may have one or more substituents, or -NR 5 R 6 (wherein, R 5 and R 6 each independently represent a hydrogen atom or a C 1-6 alkyl group which may have one or more substituents).
X represents -NH- or -O-. ]
, A salt thereof, a solvate thereof and a solvate of the salt thereof, and a compound of the formula (II):

[In the formula (II),
R 7 and R 8 each independently represent a hydrogen atom or a C 1-6 alkyl group which may have one or more substituents, or R 7 and R 8 are bonded together, and one or more of them are substituted It forms a C 2-12 alkanediyl group which may have a group.
m represents an integer of 2 to 9;
n represents 1 or 2;
Mn + represents H + or n-valent metal ion. ]
The method according to claim 1, which is at least one selected from the group consisting of compounds represented by
The method according to claim 2, wherein the compound represented by the formula (I), a salt thereof, a solvate thereof and a solvate of the salt thereof is a solvate of a salt of the compound represented by the formula (I) .
The method according to any one of claims 1 to 3, wherein the compound having a Si-O bond capable of binding to silica is a silane coupling agent.
The method according to any one of claims 1 to 4, wherein the rubber component having an olefinic double bond comprises a diene rubber.
The method according to any one of claims 1 to 4, wherein the rubber component having an olefinic double bond comprises natural rubber.
The amount of the compound (C) used is 0.1 to 10 parts by weight with respect to 100 parts by weight of the rubber component having an olefinic double bond, according to any one of claims 1 to 6. Method.
The method according to any one of claims 1 to 7, wherein the amount of silica used is 10 to 120 parts by weight with respect to 100 parts by weight of the rubber component having an olefinic double bond.
The use amount of the compound having a Si—O bond capable of binding to silica is 0.1 to 20 parts by weight with respect to 100 parts by weight of the use amount of the rubber component having an olefinic double bond. The method according to any one of the preceding claims.
A method for producing a rubber composition containing a sulfur component, comprising kneading the rubber composition obtained by the method according to any one of claims 1 to 9 with a sulfur component.
A method for producing a vulcanized rubber composition, comprising vulcanizing a rubber composition containing a sulfur component obtained by the method according to claim 10.
A rubber composition obtained by the method according to any one of claims 1 to 9.
A rubber composition containing a sulfur component obtained by the method according to claim 10.
A vulcanized rubber composition obtained by the method according to claim 11.