JPWO2016009776A1 - Manufacturing method of rubber composition for tire and pneumatic tire - Google Patents

Abstract

Rubber component (A) containing natural rubber and / or synthetic diene rubber, filler containing inorganic filler (B) containing at least silica, silane coupling agent (C) and amino acid having sulfur atom ( According to the method for producing a tire rubber composition comprising D), the tire rubber composition having improved workability, wear resistance and fuel consumption characteristics in a well-balanced manner, and the tire rubber composition are used. The produced pneumatic tire can be provided.

Description

  The present invention relates to a method for producing a tire rubber composition and a pneumatic tire produced using the tire rubber composition produced by the production method.

  In recent years, from the standpoint of resource saving, energy saving and environmental protection, there is an increasing social demand for reducing carbon dioxide emissions. In automobiles, various countermeasures such as reducing the weight of automobiles and using electric energy have been studied for the purpose of reducing discharged carbon dioxide. For this reason, automobile tires are also required to have improved fuel efficiency by improving rolling resistance, and there are also increasing demands for wear resistance and durability.

  The characteristics of these tires depend on various factors such as the structure of the tire and the materials used, but are particularly affected by the performance of the rubber composition used in the tread portion in contact with the road surface. Many technical improvements of rubber compositions have been studied, proposed, and put into practical use. For example, in order to improve the balance between low fuel consumption and wear resistance, the use of silica or various silane coupling agents has been studied. In this case, however, there is a problem that workability deteriorates. In Patent Document 1, a specific polysulfide compound is used to improve the reactivity with a specific silane coupling agent to solve the above problem. However, since the polysulfide compound used is a special chemical, the cost is low. There is a problem that is high. Patent Document 2 includes a rubber composition comprising diene rubber, silica, a sulfur-containing silane coupling agent, an amino acid and urea, and the urea is mixed as a urea aqueous solution having a predetermined concentration. In the present invention, it is considered that the combined use of an amino acid and an aqueous urea solution accelerates the hydrolysis of the silane coupling agent and promotes the dispersion of silica.

JP 2014-047324 A JP 2012-224665A

  The present invention relates to a method for producing a rubber composition for a tire having improved workability, wear resistance and fuel consumption characteristics in a well-balanced manner, and a pneumatic tire produced using the tire rubber composition produced by the production method About.

  As a result of intensive studies to solve the above problems, the present inventors have found that when a rubber component containing natural rubber or synthetic diene rubber is kneaded with a filler containing at least silica and a silane coupling agent, The inventors have found that the above problem can be solved by adding an amino acid having an atom at a predetermined timing, and further studies have been made to complete the present invention.

（式中、Ｒ¹は複数ある場合には同一でも異なっていてもよく、各々炭素数１〜８の直鎖環状もしくは分枝のアルキル基、炭素数２〜８の直鎖もしくは分枝のアルコキシアルキル基または水素原子であり、Ｒ²は複数ある場合には同一でも異なっていてもよく、各々炭素数１〜８の直鎖、環状もしくは分枝のアルキル基であり、Ｒ³は複数ある場合には同一でも異なっていてもよく、各々炭素数１〜８の直鎖もしくは分枝のアルキレン基である。
ａは平均値として２〜６であり、ｐおよびｒは同一でも異なっていてもよく、各々平均値として０〜３である。但しｐおよびｒの双方が３であることはない。）

（式中、Ｒ⁴は−Ｃｌ、−Ｂｒ、Ｒ⁹Ｏ−、Ｒ⁹Ｃ（＝Ｏ）Ｏ−、Ｒ⁹Ｒ¹⁰Ｃ＝ＮＯ−、Ｒ⁹Ｒ¹⁰ＣＮＯ−、Ｒ⁹Ｒ¹⁰Ｎ−、および−（ＯＳｉＲ⁹Ｒ¹⁰）_h（ＯＳｉＲ⁹Ｒ¹⁰Ｒ¹¹）から選択される一価の基（Ｒ⁹、Ｒ¹⁰およびＲ¹¹は各々水素原子または炭素数１〜１８の一価の炭化水素基であり、ｈは平均値として１〜４である。）であり、Ｒ⁵はＲ⁴、水素原子または炭素数１〜１８の一価の炭化水素基であり、Ｒ⁶はＲ⁴、Ｒ⁵、水素原子または−［Ｏ（Ｒ¹²Ｏ）_j］_0.5で示される一価の基（Ｒ¹²は炭素数１〜１８のアルキレン基、ｊは１〜４の整数である。）であり、Ｒ⁷は炭素数１〜１８の二価の炭化水素基であり、Ｒ⁸は炭素数１〜１８の一価の炭化水素基である。ｘ、ｙおよびｚは、ｘ＋ｙ＋２ｚ＝３、０≦ｘ≦３、０≦ｙ≦２、０≦ｚ≦１の関係を満たす数である。）

（式中、Ｒ¹³は複数ある場合には同一でも異なっていてもよく、各々炭素数１〜８の直鎖、環状もしくは分枝のアルキル基、炭素数２〜８の直鎖もしくは分枝のアルコキシアルキル基または水素原子であり、Ｒ¹⁴は複数ある場合には同一でも異なっていてもよく、各々炭素数１〜８の直鎖、環状もしくは分枝のアルキル基であり、Ｒ¹⁵は複数ある場合には同一でも異なっていてもよく、各々炭素数１〜８の直鎖もしくは分枝のアルキレン基である。
Ｒ¹⁶は一般式
（−Ｓ−Ｒ¹⁷−Ｓ−）、（−Ｒ¹⁸−Ｓ_m1−Ｒ¹⁹−）および（−Ｒ²⁰−Ｓ_m2−Ｒ²¹−Ｓ_m3−Ｒ²²−）のいずれかの二価の基（Ｒ¹⁷〜Ｒ²²は各々炭素数１〜２０の二価の炭化水素基、二価の芳香族基、または硫黄および酸素以外のヘテロ元素を含む二価の有機基であり、ｍ１、ｍ２およびｍ３は各々平均値として１以上４未満である。）であり、複数あるｋは同一でも異なっていてもよく、各々平均値として１〜６であり、ｓおよびｔは各々平均値として０〜３である。但しｓおよびｔの双方が３であることはない。）

（式中、Ｒ²³は炭素数１〜２０の直鎖、分岐または環状のアルキル基であり、複数あるＧは同一でも異なっていてもよく、各々炭素数１〜９のアルカンジイル基またはアルケンジイル基であり、複数あるＺ^aは同一でも異なっていてもよく、各々二つの珪素原子と結合することのできる官能基であり、且つ［−０−］_0.5、［−０−Ｇ−］_0.5および［−Ｏ−Ｇ−Ｏ−］_0.5から選ばれる官能基であり、複数あるＺ^bは同一でも異なっていてもよく、各々二つの珪素原子と結合することのできる官能基であり、且つ［−Ｏ−Ｇ−Ｏ−］_0.5で表される官能基であり、複数あるＺ^cは同一でも異なっていてもよく、各々−Ｃｌ、−Ｂｒ、−ＯＲ^a、Ｒ^aＣ（＝Ｏ）Ｏ−、Ｒ^aＲ^bＣ＝ＮＯ−、Ｒ^aＲ^bＮ−、Ｒ^a−およびＨＯ−Ｇ−Ｏ−（Ｇは上記表記と一致する。）から選ばれる官能基であり、Ｒ^aおよびＲ^bは各々炭素数１〜２０の直鎖、分岐または環状のアルキル基である。ｍ、ｎ、ｕ、ｖおよびｗは、１≦ｍ≦２０、０≦ｎ≦２０、０≦ｕ≦３、０≦ｖ≦２、０≦ｗ≦１であり、且つ（ｕ／２）＋ｖ＋２ｗ＝２または３である。Ａ部が複数である場合、複数のＡ部におけるＺ^a _u、Ｚ^b _vおよびＺ^c _wそれぞれにおいて、同一でも異なっていてもよく、Ｂ部が複数である場合、複数のＢ部におけるＺ^a _u、Ｚ^b _vおよびＺ^c _wそれぞれにおいて、同一でも異なってもよい。）
［６］シランカップリング剤（Ｃ）が、一般式（Ｉ）で表わされる化合物である、上記［５］記載のタイヤ用ゴム組成物の製造方法、
［７］充填材中の無機充填材（Ｂ）の含有量が３０質量％以上、好ましくは４０質量％以上、さらに好ましくは７０質量％以上である上記［１］〜［６］のいずれか１項に記載のタイヤ用ゴム組成物の製造方法、
［８］混練の第一段階におけるゴム組成物中の硫黄原子を有するアミノ酸（Ｄ）の分子数が、シランカップリング剤（Ｃ）の分子数の０．１〜１．０倍、好ましくは０．２〜０．８倍、より好ましくは０．３〜０．７倍である、上記［１］〜［７］のいずれか１項に記載のタイヤ用ゴム組成物の製造方法、
［９］混練の第一段階におけるゴム組成物に含まれる有機酸化合物中の５０モル％以上が、ステアリン酸である、上記［１］〜［８］のいずれか１項に記載のタイヤ用ゴム組成物の製造方法、
［１０］上記［１］〜［９］のいずれか１項に記載の製造方法により製造されたタイヤ用ゴム組成物を用いて作製した空気入りタイヤ、
に関する。That is, the present invention
[1] Rubber component (A) containing natural rubber and / or synthetic diene rubber, filler containing inorganic filler (B) containing at least silica, silane coupling agent (C), and amino acid having sulfur atom (D A process for producing a rubber composition comprising
The kneading process is composed of at least two stages of a first stage of kneading not containing a vulcanizing chemical and a final stage of kneading containing a vulcanizing chemical,
In the first stage of kneading, all or a part of the silane coupling agent (C) is added and kneaded at the same time or after all or part of the rubber component (A) and the inorganic filler (B) are kneaded. In addition, a step of adding and kneading the amino acid (D) having the sulfur atom at the same time as or after adding all or a part of the silane coupling agent (C) is performed. Manufacturing method of rubber composition for tire,
[2] One or more amino acids (D) having a sulfur atom are selected from the group consisting of (1) an amino acid having a disulfide bond, (2) an amino acid having a mercapto group, and (3) an amino acid having a monosulfide bond The method for producing a rubber composition for a tire according to the above [1],
[3] In the first stage of kneading, the temperature of the rubber composition is 75 to 180 ° C, preferably 90 to 170 ° C, more preferably 105 to 165 ° C, still more preferably 120 to 155 ° C, and still more preferably 125 to 140. A method for producing a rubber composition for a tire according to the above [1] or [2], wherein the amino acid (D) having a sulfur atom is added when the temperature reaches ° C.
[4] In the first stage of kneading, the time from the addition of the silane coupling agent (C) to the rubber component (A) to the addition of the amino acid (D) having a sulfur atom is within 180 seconds, The method for producing a rubber composition for a tire according to any one of the above [1] to [3], preferably 10 to 180 seconds, more preferably 30 to 150 seconds, and still more preferably 30 to 120 seconds,
[5] Any one of the above-mentioned [1] to [4], wherein the silane coupling agent (C) is at least one selected from the group consisting of compounds represented by the following general formulas (I) to (IV): A method for producing the tire rubber composition according to the item,

(In the formula, when there are a plurality of R ^{1 s} , they may be the same or different, and each of them may be a linear cyclic or branched alkyl group having 1 to 8 carbon atoms, or a linear or branched alkoxy group having 2 to 8 carbon atoms. An alkyl group or a hydrogen atom, and when there are a plurality of R ^{2 s} , they may be the same or different and each is a linear, cyclic or branched alkyl group having 1 to 8 carbon atoms, and when there are a plurality of R ³ May be the same or different and each is a linear or branched alkylene group having 1 to 8 carbon atoms.
a is 2 to 6 as an average value, p and r may be the same or different, and each is 0 to 3 as an average value. However, both p and r are not 3. )

(Wherein, R ⁴ is ^{-Cl, -Br, R 9 O-,} R 9 C (= O) O-, R 9 R 10 C = NO-, R 9 R 10 CNO-, R 9 R 10 N- , And-(OSiR ⁹ R ¹⁰ ) _h (OSiR ⁹ R ¹⁰ R ¹¹ ) are each a monovalent group (R ⁹ , R ¹⁰ and R ¹¹ are each a hydrogen atom or a monovalent carbon atom having 1 to 18 carbon atoms. H is an average value of 1 to 4, and R ⁵ is R ⁴ , a hydrogen atom or a monovalent hydrocarbon group having 1 to 18 carbon atoms, R ⁶ is R ⁴ , R ⁵ , a hydrogen atom or a monovalent group represented by — [O (R ¹² O) _j ] _0.5 (R ¹² is an alkylene group having 1 to 18 carbon atoms, j is an integer of 1 to 4). , R ⁷ is a divalent hydrocarbon group having 1 to 18 carbon atoms, and R ⁸ is a monovalent hydrocarbon group having 1 to 18 carbon atoms, x, y and z are x + y + 2z = 3, 0 ≦ x ≦ 3, 0 ≦ y ≦ Are numbers satisfying the relation of 0 ≦ z ≦ 1.)

(In the formula, when there are a plurality of R ^{13 s} , they may be the same or different, and each of them may be a linear, cyclic or branched alkyl group having 1 to 8 carbon atoms, a linear or branched alkyl group having 2 to 8 carbon atoms. An alkoxyalkyl group or a hydrogen atom, and when there are a plurality of R ^{14 s} , they may be the same or different, each being a linear, cyclic or branched alkyl group having 1 to 8 carbon atoms, and a plurality of R ^{15 s.} In some cases, they may be the same or different, and each is a linear or branched alkylene group having 1 to 8 carbon atoms.
R ¹⁶ is any one of the general formulas (—S—R ¹⁷ —S—), (—R ¹⁸ —S _m1 —R ¹⁹ —) and (—R ²⁰ —S _m2 —R ²¹ —S _m3 —R ²² —). Divalent groups (R ^{17 to} R ²² are each a divalent hydrocarbon group having 1 to 20 carbon atoms, a divalent aromatic group, or a divalent organic group containing a hetero element other than sulfur and oxygen. , M1, m2 and m3 are each an average value of 1 or more and less than 4, and a plurality of k may be the same or different, each being an average value of 1 to 6, and s and t are each an average The value is 0-3. However, both s and t are not 3. )

(In the formula, R ²³ is a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, and a plurality of Gs may be the same or different, and each is an alkanediyl group or alkenediyl group having 1 to 9 carbon atoms. , and the the plurality of Z ^a may be the same or different, is a functional group capable of binding with each of two silicon atoms, and _{[-0-] 0.5, [- 0} -G-] 0.5 and [ —O—G—O—] is a functional group selected from _0.5 , and a plurality of Z ^b may be the same or different, each being a functional group capable of bonding to two silicon atoms, and [—O -G-O-] is a functional group represented by _0.5 , and a plurality of Z ^c may be the same or different, and each represents —Cl, —Br, —OR ^a , R ^a C (═O) O—, ^{R a R b C = NO-,} R a R b N-, R a - and HO-G-O- (G above table Consistent with a functional group selected from.), R ^a and R ^b are each a straight-chain having 1 to 20 carbon atoms, branched or cyclic alkyl group .m, n, u, v and w are 1 ≦ m ≦ 20, 0 ≦ n ≦ 20, 0 ≦ u ≦ 3, 0 ≦ v ≦ 2, 0 ≦ w ≦ 1, and (u / 2) + v + 2w = 2 or 3. A part is plural In some cases, each of Z ^a _u , Z ^b _v and Z ^c _w in a plurality of A parts may be the same or different. When there are a plurality of B parts, Z ^a _u and Z ^b _{v in} ^a plurality of B parts And Z ^c _w may be the same or different.)
[6] The method for producing a tire rubber composition according to the above [5], wherein the silane coupling agent (C) is a compound represented by the general formula (I),
[7] Any one of [1] to [6] above, wherein the content of the inorganic filler (B) in the filler is 30% by mass or more, preferably 40% by mass or more, and more preferably 70% by mass or more. A method for producing the tire rubber composition according to the item,
[8] The number of molecules of the amino acid (D) having a sulfur atom in the rubber composition in the first stage of kneading is 0.1 to 1.0 times the number of molecules of the silane coupling agent (C), preferably 0. The method for producing a rubber composition for a tire according to any one of the above [1] to [7], which is 2 to 0.8 times, more preferably 0.3 to 0.7 times,
[9] The tire rubber according to any one of [1] to [8] above, wherein 50 mol% or more of the organic acid compound contained in the rubber composition in the first stage of kneading is stearic acid. Production method of the composition,
[10] A pneumatic tire produced using the tire rubber composition produced by the production method according to any one of [1] to [9] above,
About.

  According to the present invention, a method for producing a rubber composition for a tire having a well-balanced improvement in workability during vulcanization, wear resistance after vulcanization, and fuel consumption characteristics, and a tire produced by the production method A pneumatic tire produced using the rubber composition can be provided. Further, according to the production method of the present invention, it is not necessary to use an additional component such as urea (more specifically, urea aqueous solution).

  Hereinafter, the configuration of the present invention will be described in detail.

<Manufacturing method>
The rubber composition production method of the present invention comprises a rubber component (A) containing natural rubber and / or a synthetic diene rubber, a filler containing an inorganic filler (B) containing at least silica, a silane coupling agent (C ) And an amino acid (D) having a sulfur atom,
The kneading process is composed of at least two stages of a first stage of kneading not containing a vulcanizing chemical and a final stage of kneading containing a vulcanizing chemical,
In the first stage of kneading, all or a part of the silane coupling agent (C) is added and kneaded at the same time or after all or part of the rubber component (A) and the inorganic filler (B) are kneaded. Furthermore, the process further comprises a step of adding and kneading the amino acid (D) having the sulfur atom at the same time or after the addition of all or part of the silane coupling agent (C). It is characterized by.

(First stage of kneading)
The first stage of kneading is a kneading stage that does not contain a so-called vulcanizing chemical, adding the inorganic filler (B) and the silane coupling agent (C) to the rubber component (A) and kneading, The present invention is characterized in that the amino acid (D) having a sulfur atom is added and kneaded in the first stage. In the present invention, the addition of the sulfur atom-containing amino acid (D) in the first stage of kneading enhances the coupling activity of the silane coupling agent (C), whereby the rubber composition of the inorganic filler is obtained. It is for making dispersion | distribution of more favorable. In addition, the timing of adding the amino acid (D) having a sulfur atom is “at the same time or after adding all or a part of the silane coupling agent (C)”. This is for further enhancing the effect of improving the coupling activity due to the blending of That is, after the reaction between the inorganic filler (B) and the silane coupling agent (C) has sufficiently proceeded, the reaction between the silane coupling agent (C) and the rubber component (A) can proceed. is there. Therefore, the first stage of kneading is “the rubber component (A) and the part of the inorganic filler (B) are kneaded at the same time or thereafter, and a part of the silane coupling agent (C) is added and kneaded, In the case of "comprising a step of adding and further kneading the amino acid (D) having the sulfur atom at the same time as or after adding a part of the silane coupling agent (C)" When the amino acid (D) having a sulfur atom is added, it is preferable that the inorganic filler (B) and the silane coupling agent (C) have all been added. That is, it is preferable that a part of the inorganic filler (B) and the silane coupling agent (C) has already been added in an earlier step. The first stage of kneading is a stage in which the rubber component (A), the inorganic filler (B), and the silane coupling agent (C) are kneaded. For example, the rubber component ( It does not include the step of kneading A) with a filler other than the inorganic filler (B) or the step of preliminarily kneading (kneading) only the rubber component (A). Here, the vulcanized chemical refers to a chemical related to vulcanization, and specifically refers to, for example, a vulcanizing agent and a vulcanization accelerator.

  In the first stage of kneading, the timing of adding the amino acid (D) having a sulfur atom is the same as when the silane coupling agent (C) (preferably all of them) has been added, or within a certain period of time thereafter. is there. The range of the certain time is preferably, for example, within 180 seconds. The timing for adding the amino acid (D) having a sulfur atom is more preferably 10 to 180 seconds after the addition of the silane coupling agent (C) (preferably, all of them) is completed. Further, the lower limit is more preferably 30 seconds or more, the upper limit is more preferably 150 seconds or less, and even more preferably 120 seconds or less. If this time is 10 seconds or more, the reaction of (B) and (C) can be advanced in advance, which is preferable. On the other hand, when this time exceeds 180 seconds, the reaction of (B) and (C) progresses too much, and there is a tendency that the further effect by adding (D) is difficult to enjoy.

  In order to further increase the coupling activity of the silane coupling agent (C), the temperature of the rubber composition when adding the amino acid (D) having a sulfur atom is 75 to 180 ° C. in the first stage of kneading. It is preferable that If the temperature is less than 75 ° C., it tends to be difficult to increase the coupling activity, and if it exceeds 180 ° C., the rubber may deteriorate due to the high temperature. The lower limit value of the temperature is more preferably 90 ° C, further preferably 105 ° C, more preferably 120 ° C, and further preferably 125 ° C. On the other hand, the upper limit of the temperature is more preferably 170 ° C., further preferably 165 ° C., further preferably 155 ° C., and further preferably 140 ° C.

  The first stage of kneading can be further divided into a plurality of stages. For example, first, a part of the inorganic filler (B) and / or a part of the silane coupling agent (C) is added to the rubber component (A) and kneaded. And then kneading the kneaded product by adding the remainder of the inorganic filler (B) and / or the remainder of the silane coupling agent (C) and the amino acid (D) having a sulfur atom. For example, the stage of obtaining In this case, each chemical | medical agent of (B)-(D) may be added at once at each step, or may be added sequentially at intervals according to the order of (B)-(D). Good. Here, as described above, the timing of adding (D) is the same as when all of the silane coupling agent (C) has been added, or within a certain time.

(Final stage of kneading)
In the present invention, the final stage of kneading refers to the final stage of kneading in which a vulcanized chemical is added and kneaded.

(Middle stage of kneading)
The kneading step of the rubber composition in the present invention may further include an intermediate stage of kneading, if necessary, between the first stage of kneading and the final stage of kneading. Here, the intermediate stage of kneading is a chemical compounded in the rubber composition, and is a chemical other than the above (A) to (D) and the vulcanized chemical, for example, a filler other than the inorganic filler (B). Etc., and kneading.

(Kneading time / temperature)
In the first stage of kneading, the maximum temperature of the rubber composition is preferably 120 to 190 ° C, more preferably 130 to 175 ° C, and further preferably 140 to 170 ° C. The kneading time is preferably from 10 seconds to 20 minutes, more preferably from 30 seconds to 10 minutes, and further preferably from 60 seconds to 5 minutes.

  In the case of including an intermediate stage of kneading, the maximum temperature of the rubber composition in the intermediate stage is preferably 120 to 190 ° C, more preferably 130 to 175 ° C, and 140 to 170 ° C. Further preferred. The kneading time is preferably from 10 seconds to 20 minutes, more preferably from 30 seconds to 10 minutes, and further preferably from 60 seconds to 5 minutes.

  In the final stage of kneading, the maximum temperature of the rubber composition is preferably 60 to 140 ° C, more preferably 80 to 120 ° C, and further preferably 100 to 120 ° C. The kneading time is preferably 10 seconds to 20 minutes, more preferably 10 seconds to 10 minutes, and further preferably 20 seconds to 5 minutes.

  When proceeding from one stage to the next stage, it is preferable to lower the temperature of the rubber composition by 10 ° C. or more from the temperature after completion of kneading at that stage before proceeding to the next stage.

  The production method of the present invention can be carried out by appropriately kneading other chemicals usually blended in this field, in addition to the above chemicals.

<Rubber component (A)>
In the method for producing a rubber composition of the present invention, the rubber component (A) is a rubber component containing natural rubber (NR) and / or a synthetic diene rubber, and as the synthetic diene rubber, styrene- Butadiene copolymer rubber (SBR), polybutadiene rubber (BR), polyisoprene rubber (IR), butyl rubber (IIR), ethylene-propylene-diene terpolymer rubber (EPDM) and the like can be used. Natural rubber and synthetic diene rubber may be used singly or as a blend of two or more.

<Silane coupling agent (C)>
As the silane coupling agent (C) in the present invention, a silane coupling agent conventionally used in combination with silica can be used in the rubber industry. For example, bis (3-triethoxysilylpropyl) disulfide, bis ( 3-mercapto sulfides such as 3-triethoxysilylpropyl) tetrasulfide, Si75 manufactured by Evonik Degussa (bis (3-triethoxysilylpropyl) polysulfide having an average number of S of 2.4 in one molecule) Mercapto such as propyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, Si363 manufactured by EVONIK-DEGUSSA, NXT, NXT-Z30, NXT-Z45, NXT-Z60 manufactured by Momentive Performance Materials , Vinyl type such as vinyltriethoxysilane, amino type such as 3-aminopropyltriethoxysilane, glycidoxy type of γ-glycidoxypropyltriethoxysilane, nitro type such as 3-nitropropyltrimethoxysilane, 3-chloro Examples include chloro-based compounds such as propyltrimethoxysilane. Among these, from the viewpoint of dispersibility of silica, a sulfide-based silane coupling agent and a mercapto-based silane coupling agent are preferable.

  The silane coupling agent (C) is preferably at least one selected from the group consisting of compounds represented by the following general formulas (I) to (IV). In the present invention, by using such a silane coupling agent (C), a tire rubber composition having excellent workability during rubber processing and good wear resistance can be obtained. Hereinafter, the following general formulas (I) to (IV) will be described in order.

（式中、Ｒ¹は複数ある場合には同一でも異なっていてもよく、各々炭素数１〜８の直鎖、環状もしくは分枝のアルキル基、炭素数２〜８の直鎖もしくは分枝のアルコキシアルキル基または水素原子であり、Ｒ²は複数ある場合には同一でも異なっていてもよく、各々炭素数１〜８の直鎖、環状もしくは分枝のアルキル基であり、Ｒ³は複数ある場合には同一でも異なっていてもよく、各々炭素数１〜８の直鎖もしくは分枝のアルキレン基である。ａは平均値として２〜６であり、ｐおよびｒは同一でも異なっていてもよく、各々平均値として０〜３である。但しｐおよびｒの双方が３であることはない。）

(In the formula, when there are a plurality of R ^{1 s} , they may be the same or different, and each of them may be a linear, cyclic or branched alkyl group having 1 to 8 carbon atoms, a linear or branched alkyl group having 2 to 8 carbon atoms. An alkoxyalkyl group or a hydrogen atom, and when there are a plurality of R ^{2 s} , they may be the same or different and each is a linear, cyclic or branched alkyl group having 1 to 8 carbon atoms, and there are a plurality of R ³ In some cases, they may be the same or different, and each is a linear or branched alkylene group having 1 to 8 carbon atoms, a is an average value of 2 to 6, and p and r may be the same or different. Well, each average is 0-3, except that both p and r are not 3.

  Specific examples of the silane coupling agent (C) represented by the general formula (I) include bis (3-triethoxysilylpropyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, and bis (3- Methyldimethoxysilylpropyl) tetrasulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (3-triethoxysilylpropyl) disulfide, bis (3-trimethoxysilylpropyl) disulfide, bis (3-methyldimethoxysilylpropyl) ) Disulfide, bis (2-triethoxysilylethyl) disulfide, bis (3-triethoxysilylpropyl) trisulfide, bis (3-trimethoxysilylpropyl) trisulfide, bis (3-methyldimethoxysilylpropyl) trisulfur Bis (2-triethoxysilylethyl) trisulfide, bis (3-monoethoxydimethylsilylpropyl) tetrasulfide, bis (3-monoethoxydimethylsilylpropyl) trisulfide, bis (3-monoethoxydimethylsilylpropyl) ) Disulfide, bis (3-monomethoxydimethylsilylpropyl) tetrasulfide, bis (3-monomethoxydimethylsilylpropyl) trisulfide, bis (3-monomethoxydimethylsilylpropyl) disulfide, bis (2-monoethoxydimethylsilylethyl) ) Tetrasulfide, bis (2-monoethoxydimethylsilylethyl) trisulfide, bis (2-monoethoxydimethylsilylethyl) disulfide and the like.

（式中、Ｒ⁴は−Ｃｌ、−Ｂｒ、Ｒ⁹Ｏ−、Ｒ⁹Ｃ（＝Ｏ）Ｏ−、Ｒ⁹Ｒ¹⁰Ｃ＝ＮＯ−、Ｒ⁹Ｒ¹⁰ＣＮＯ−、Ｒ⁹Ｒ¹⁰Ｎ−、および−（ＯＳｉＲ⁹Ｒ¹⁰）_h（ＯＳｉＲ⁹Ｒ¹⁰Ｒ¹¹）から選択される一価の基（Ｒ⁹、Ｒ¹⁰およびＲ¹¹は各々水素原子または炭素数１〜１８の一価の炭化水素基であり、ｈは平均値として１〜４である。）であり、Ｒ⁵はＲ⁴、水素原子または炭素数１〜１８の一価の炭化水素基であり、Ｒ⁶はＲ⁴、Ｒ⁵、水素原子または−［Ｏ（Ｒ¹²Ｏ）_j］_0.5で示される一価の基（Ｒ¹²は炭素数１〜１８のアルキレン基、ｊは１〜４の整数である。）であり、Ｒ⁷は炭素数１〜１８の二価の炭化水素基であり、Ｒ⁸は炭素数１〜１８の一価の炭化水素基である。ｘ、ｙおよびｚは、ｘ＋ｙ＋２ｚ＝３、０≦ｘ≦３、０≦ｙ≦２、０≦ｚ≦１の関係を満たす数である。）

(Wherein, R ⁴ is ^{-Cl, -Br, R 9 O-,} R 9 C (= O) O-, R 9 R 10 C = NO-, R 9 R 10 CNO-, R 9 R 10 N- , And-(OSiR ⁹ R ¹⁰ ) _h (OSiR ⁹ R ¹⁰ R ¹¹ ) are each a monovalent group (R ⁹ , R ¹⁰ and R ¹¹ are each a hydrogen atom or a monovalent carbon atom having 1 to 18 carbon atoms. H is an average value of 1 to 4, and R ⁵ is R ⁴ , a hydrogen atom or a monovalent hydrocarbon group having 1 to 18 carbon atoms, R ⁶ is R ⁴ , R ⁵ , a hydrogen atom or a monovalent group represented by — [O (R ¹² O) _j ] _0.5 (R ¹² is an alkylene group having 1 to 18 carbon atoms, j is an integer of 1 to 4). , R ⁷ is a divalent hydrocarbon group having 1 to 18 carbon atoms, and R ⁸ is a monovalent hydrocarbon group having 1 to 18 carbon atoms, x, y and z are x + y + 2z = 3, 0 ≦ x ≦ 3, 0 ≦ y ≦ Are numbers satisfying the relation of 0 ≦ z ≦ 1.)

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

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

  Specific examples of the silane coupling agent (C) represented by the general formula (II) include 3-hexanoylthiopropyltriethoxysilane, 3-octanoylthiopropyltriethoxysilane, 3-decanoylthiopropyltri Ethoxysilane, 3-lauroylthiopropyltriethoxysilane, 2-hexanoylthioethyltriethoxysilane, 2-octanoylthioethyltriethoxysilane, 2-decanoylthioethyltriethoxysilane, 2-lauroylthioethyltriethoxysilane 3-hexanoylthiopropyltrimethoxysilane, 3-octanoylthiopropyltrimethoxysilane, 3-decanoylthiopropyltrimethoxysilane, 3-lauroylthiopropyltrimethoxysilane, 2-hexanoylthioethyltrimethoxy Run, 2-octanoylthiopropyl ethyltrimethoxysilane, 2- deca Neu thio ethyltrimethoxysilane, and 2-lauroyl thio ethyl trimethoxysilane. Among these, 3-octanoylthiopropyltriethoxysilane (manufactured by General Electric Silicones, trademark: NXT silane) is particularly preferable.

（式中、Ｒ¹³は複数ある場合には同一でも異なっていてもよく、各々炭素数１〜８の直鎖、環状もしくは分枝のアルキル基、炭素数２〜８の直鎖もしくは分枝のアルコキシアルキル基または水素原子であり、Ｒ¹⁴は複数ある場合には同一でも異なっていてもよく、各々炭素数１〜８の直鎖、環状もしくは分枝のアルキル基であり、Ｒ¹⁵は複数ある場合には同一でも異なっていてもよく、各々炭素数１〜８の直鎖もしくは分枝のアルキレン基である。Ｒ¹⁶は一般式
（−Ｓ−Ｒ¹⁷−Ｓ−）、（−Ｒ¹⁸−Ｓ_m1−Ｒ¹⁹−）および（−Ｒ²⁰−Ｓ_m2−Ｒ²¹−Ｓ_m3−Ｒ²²−）のいずれかの二価の基（Ｒ¹⁷〜Ｒ²²は各々炭素数１〜２０の二価の炭化水素基、二価の芳香族基、または硫黄および酸素以外のヘテロ元素を含む二価の有機基であり、ｍ１、ｍ２およびｍ３は各々平均値として１以上４未満である。）であり、複数あるｋは同一でも異なっていてもよく、各々平均値として１〜６であり、ｓおよびｔは各々平均値として０〜３である。但しｓおよびｔの双方が３であることはない。

(In the formula, when there are a plurality of R ^{13 s} , they may be the same or different, and each of them may be a linear, cyclic or branched alkyl group having 1 to 8 carbon atoms, a linear or branched alkyl group having 2 to 8 carbon atoms. An alkoxyalkyl group or a hydrogen atom, and when there are a plurality of R ^{14 s} , they may be the same or different, each being a linear, cyclic or branched alkyl group having 1 to 8 carbon atoms, and a plurality of R ^{15 s.} In some cases, they may be the same or different, and each is a linear or branched alkylene group having 1 to 8 carbon atoms, R ¹⁶ is represented by the general formula (—S—R ¹⁷ —S—), (—R ¹⁸ —). S _m1 -R ¹⁹ -) and _{^{(-R 20 -S m2 -R 21 -S}} m3 -R 22 -) or a divalent group of (R ¹⁷ to R ²² each C 1 -C 20 divalent carbon of A divalent organic group containing a hetero element other than sulfur and oxygen, and m1, m 2 and m3 are each an average value of 1 or more and less than 4, and a plurality of k may be the same or different, each being an average value of 1 to 6, and s and t being 0 as an average value, respectively. -3, provided that both s and t are not 3.

As a specific example of the silane coupling agent (C) represented by the general formula (III),
Average composition formula _{(CH 3 CH 2 O) 3} Si- (CH 2) 3 -S 2 - (CH 2) 6 -S 2 - (CH 2) 3 -Si (OCH 2 CH 3) 3,
Average composition formula _{(CH 3 CH 2 O) 3} Si- (CH 2) 3 -S 2 - (CH 2) 10 -S 2 - (CH 2) 3 -Si (OCH 2 CH 3) 3,
Average composition formula _{(CH 3 CH 2 O) 3} Si- (CH 2) 3 -S 3 - (CH 2) 6 -S 3 - (CH 2) 3 -Si (OCH 2 CH 3) 3,
Average composition formula (CH ₃ CH ₂ O) ₃ Si— (CH ₂ ) ₃ —S ₄ — (CH ₂ ) ₆ —S ₄ — (CH ₂ ) ₃ —Si (OCH ₂ CH ₃ ) ₃ ,
Average composition formula _{(CH 3 CH 2 O) 3} Si- (CH 2) 3 -S- (CH 2) 6 -S 2 - (CH 2) 6 -S- (CH 2) 3 -Si (OCH 2 CH 3 ₃
Average composition formula _{(CH 3 CH 2 O) 3} Si- (CH 2) 3 -S- (CH 2) 6 -S 2.5 - (CH 2) 6 -S- (CH 2) 3 -Si (OCH 2 CH 3 ₃
Average composition formula _{(CH 3 CH 2 O) 3} Si- (CH 2) 3 -S- (CH 2) 6 -S 3 - (CH 2) 6 -S- (CH 2) 3 -Si (OCH 2 CH 3 ₃
Average composition formula _{(CH 3 CH 2 O) 3} Si- (CH 2) 3 -S- (CH 2) 6 -S 4 - (CH 2) 6 -S- (CH 2) 3 -Si (OCH 2 CH 3 ₃
Average composition formula _{(CH 3 CH 2 O) 3} Si- (CH 2) 3 -S- (CH 2) 10 -S 2 - (CH 2) 10 -S- (CH 2) 3 -Si (OCH 2 CH 3 ₃
Average composition formula _{(CH 3 CH 2 O) 3} Si- (CH 2) 3 -S 4 - (CH 2) 6 -S 4 - (CH 2) 6 -S 4 - (CH 2) 3 -Si (OCH 2 CH _{3) 3,}
Average composition formula _{(CH 3 CH 2 O) 3} Si- (CH 2) 3 -S 2 - (CH 2) 6 -S 2 - (CH 2) 6 -S 2 - (CH 2) 3 -Si (OCH 2 CH _{3) 3,}
Average composition formula _{(CH 3 CH 2 O) 3} Si- (CH 2) 3 -S- (CH 2) 6 -S 2 - (CH 2) 6 -S 2 - (CH 2) 6 -S- (CH 2 ) ₃ -Si (OCH ₂ CH ₃ ) _{3 and the} like are preferred.

（式中、Ｒ²³は炭素数１〜２０の直鎖、分岐または環状のアルキル基であり、複数あるＧは同一でも異なっていてもよく、各々炭素数１〜９のアルカンジイル基またはアルケンジイル基であり、複数あるＺ^aは同一でも異なっていてもよく、各々二つの珪素原子と結合することのできる官能基であり、且つ［−０−］_0.5、［−０−Ｇ−］_0.5および［−Ｏ−Ｇ−Ｏ−］_0.5から選ばれる官能基であり、複数あるＺ^bは同一でも異なっていてもよく、各々二つの珪素原子と結合することのできる官能基であり、且つ［−Ｏ−Ｇ−Ｏ−］_0.5で表される官能基であり、複数あるＺ^cは同一でも異なっていてもよく、各々−Ｃｌ、−Ｂｒ、−ＯＲ^a、Ｒ^aＣ（＝Ｏ）Ｏ−、Ｒ^aＲ^bＣ＝ＮＯ−、Ｒ^aＲ^bＮ−、Ｒ^a−およびＨＯ−Ｇ−Ｏ−（Ｇは上記表記と一致する。）から選ばれる官能基であり、Ｒ^aおよびＲ^bは各々炭素数１〜２０の直鎖、分岐または環状のアルキル基である。ｍ、ｎ、ｕ、ｖおよびｗは、１≦ｍ≦２０、０≦ｎ≦２０、０≦ｕ≦３、０≦ｖ≦２、０≦ｗ≦１であり、且つ（ｕ／２）＋ｖ＋２ｗ＝２または３である。Ａ部が複数である場合、複数のＡ部におけるＺ^a _u、Ｚ^b _vおよびＺ^c _wそれぞれにおいて、同一でも異なっていてもよく、Ｂ部が複数である場合、複数のＢ部におけるＺ^a _u、Ｚ^b _vおよびＺ^c _wそれぞれにおいて、同一でも異なってもよい。

(In the formula, R ²³ is a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, and a plurality of Gs may be the same or different, and each is an alkanediyl group or alkenediyl group having 1 to 9 carbon atoms. , and the the plurality of Z ^a may be the same or different, is a functional group capable of binding with each of two silicon atoms, and _{[-0-] 0.5, [- 0} -G-] 0.5 and [ —O—G—O—] is a functional group selected from _0.5 , and a plurality of Z ^b may be the same or different, each being a functional group capable of bonding to two silicon atoms, and [—O -G-O-] is a functional group represented by _0.5 , and a plurality of Z ^c may be the same or different, and each represents —Cl, —Br, —OR ^a , R ^a C (═O) O—, ^{R a R b C = NO-,} R a R b N-, R a - and HO-G-O- (G above table Consistent with a functional group selected from.), R ^a and R ^b are each a straight-chain having 1 to 20 carbon atoms, branched or cyclic alkyl group .m, n, u, v and w are 1 ≦ m ≦ 20, 0 ≦ n ≦ 20, 0 ≦ u ≦ 3, 0 ≦ v ≦ 2, 0 ≦ w ≦ 1, and (u / 2) + v + 2w = 2 or 3. A part is plural In some cases, each of Z ^a _u , Z ^b _v and Z ^c _w in a plurality of A parts may be the same or different. When there are a plurality of B parts, Z ^a _u and Z ^b _{v in} ^a plurality of B parts And Z ^c _w may be the same or different.

  Specific examples of the silane coupling agent (C) represented by the general formula (IV) include chemical formula (V), chemical formula (VI), and chemical formula (VII).

（式中、Ｌはそれぞれ独立して炭素数１〜９のアルカンジイル基またはアルケンジイル基であり、ｘ＝ｍ、ｙ＝ｎである。）

(In the formula, each L is independently an alkanediyl group or alkenediyl group having 1 to 9 carbon atoms, and x = m and y = n.)

  As a silane coupling agent represented by the chemical formula (V), a trademark “NXT Low-V Silane” manufactured by Momentive Performance Materials is commercially available. Moreover, as a silane coupling agent represented by chemical formula (VI), the trademark "NXT Ultra Low-V Silane" manufactured by Momentive Performance Materials is also available as a commercial product. Furthermore, examples of the silane coupling agent represented by the chemical formula (VII) include “NXT-Z” manufactured by Momentive Performance Materials.

  Since the silane coupling agent obtained by the above general formula (II), chemical formula (V), and chemical formula (VI) has a protected mercapto group, initial vulcanization (scorch) during processing in the process prior to the vulcanization process. ) Can be prevented, so that workability is improved. Moreover, since the silane coupling agent obtained by chemical formula (V), (VI) and (VII) has many alkoxysilane carbon number, there is little generation | occurrence | production of volatile compound VOC (especially alcohol), and it is preferable on working environment. Further, the silane coupling agent represented by the chemical formula (VII) is more preferable because low exothermic property is obtained as tire performance.

  The silane coupling agent (C) according to the present invention is particularly preferably a compound represented by the above general formula (I) among the compounds represented by the above general formulas (I) to (IV). By using these, activation of the polysulfide bond site of the amino acid (D) having a sulfur atom that reacts with the rubber component (A) is likely to occur.

  The silane coupling agent (C) according to the present invention preferably has a low sulfur content. For example, a in the general formula (I) is 2 to 6 as an average value, preferably 2 to 5, more preferably 2 to 4, still more preferably 2 to 3, and particularly preferably 2 to 2.5. . Moreover, although k in general formula (III) is 1-6 respectively as an average value, 1-5 are preferable, 1-4 are more preferable, 1-3 are more preferable, 1-3 are especially preferable. .

  In this invention, a silane coupling agent (C) may be used individually by 1 type, and may be used in combination of 2 or more type.

  The blending amount of the silane coupling agent (C) in the rubber composition according to the present invention is such that the mass ratio {silane coupling agent (C) / inorganic filler (B)} is (1/100) to (20/100). It is preferable that If it is (1/100) or more, the effect of improving the low heat build-up of the rubber composition will be more suitably exhibited. If it is (20/100) or less, the cost of the rubber composition will be reduced, and the economic efficiency will be reduced. This is because it improves. Furthermore, a mass ratio (3/100) to (20/100) is more preferable, and a mass ratio (4/100) to (10/100) is particularly preferable.

<Filler>
The filler used in the method for producing a rubber composition of the present invention is a filler containing an inorganic filler (B) containing at least silica.

(Inorganic filler (B))
In the inorganic filler (B), any commercially available silica can be used. Among them, wet silica, dry silica, and colloidal silica are preferably used, and wet silica is particularly preferably used. In the present invention, silica is essential as the inorganic filler (B) because silica is preferable from the viewpoint of achieving both low fuel consumption characteristics (rolling resistance characteristics) and wear resistance.

The BET specific surface area (measured in accordance with ISO 5794/1) of silica is preferably 40 to 350 m ² / g. Silica having a BET specific surface area within this range has an advantage that both rubber reinforcement and dispersibility in a rubber component can be achieved. From this point of view, the BET specific surface area is more preferably silica in the range of 80~350m ² / g, BET specific surface area of greater than 130m ² / g, more preferably silica or less 350 meters ² / g, a BET specific surface area Silica in the range of 135 to 350 m ² / g is particularly preferred. Examples of such silica include Tosoh Silica Co., Ltd., trade names “Nip Seal AQ” (BET specific surface area = 205 m ² / g), “Nip Seal KQ” (BET specific surface area = 240 m ² / g), products manufactured by Degussa. Commercially available products such as the name “Ultrazil VN3” (BET specific surface area = 175 m ² / g) can be used.

As the inorganic filler (B) other than silica, an inorganic compound represented by the following general formula (VIII) can be used.

dM ¹ · xSiO _y · zH ₂ O (VIII)

(Wherein M ¹ is a metal selected from the group consisting of aluminum, magnesium, titanium, calcium, and zirconium, an oxide or hydroxide of these metals, and a hydrate thereof, or carbonic acid of these metals. D, x, y and z are each an integer of 1 to 5, an integer of 0 to 10, an integer of 2 to 5, and an integer of 0 to 10, provided that x, When both z are 0, the inorganic compound is at least one metal, metal oxide or metal hydroxide selected from aluminum, magnesium, titanium, calcium and zirconium.)

As the inorganic compound represented by the general formula (VIII), .gamma.-alumina, alumina (Al ₂ O ₃₎ such as α- alumina, boehmite, alumina monohydrate such as diaspore _{(Al 2 O 3 · H 2} O ), Aluminum hydroxide such as gibbsite, bayerite [Al (OH) ₃ ], aluminum carbonate [Al ₂ (CO ₃ ) ₂ ], magnesium hydroxide [Mg (OH) ₂ ], magnesium oxide (MgO), magnesium carbonate (MgCO _3), talc _{(3MgO · 4SiO 2 · H 2} O), attapulgite _{(5MgO · 8SiO 2 · 9H 2} O), titanium white (TiO _2), titanium black (TiO _2n-1), calcium oxide (CaO) , calcium hydroxide [Ca (OH) _2], magnesium aluminum oxide _{(MgO · Al 2 O 3)} , clay _{(Al 2 O 3 · 2SiO 2} ), Kao Down _{(Al 2 O 3 · 2SiO 2} · 2H 2 O), pyrophyllite _{(Al 2 O 3 · 4SiO 2} · H 2 O), bentonite _{(Al 2 O 3 · 4SiO 2} · 2H 2 O), aluminum silicate (Al ₂ SiO ₅ , Al ₄ · 3SiO ₄ · 5H ₂ O, etc.), magnesium silicate (Mg ₂ SiO ₄ , MgSiO ₃ etc.), calcium silicate (Ca ₂ · SiO ₄ etc.), aluminum calcium silicate (Al ₂ O ₃ · CaO · 2SiO ₂ etc.), magnesium calcium silicate (CaMgSiO ₄ ), calcium carbonate (CaCO ₃ ), zirconium oxide (ZrO ₂ ), zirconium hydroxide [ZrO (OH) ₂ · nH ₂ O], carbonic acid zirconium _{[Zr (CO 3) 2]} , crystalline aluminosilicate containing hydrogen, alkali metal or alkaline earth metal which corrects a charge as various zeolites Etc. can be used. Further, it is preferable that M ¹ in the general formula (VIII) is at least one selected from aluminum metal, aluminum oxide or hydroxide, hydrates thereof, and aluminum carbonate. These inorganic compounds represented by the general formula (VIII) may be used alone or in combination of two or more. The average particle size of these inorganic compounds is preferably in the range of 0.01 to 10 μm, and more preferably in the range of 0.05 to 5 μm, from the viewpoint of kneading workability, wear resistance, and wet grip performance balance.

  The inorganic filler (B) in the present invention may be used alone or in combination with silica and one or more inorganic compounds represented by the general formula (VIII).

The filler in the present invention may contain carbon black in addition to the inorganic filler (B) described above, if desired. By containing carbon black, it is possible to enjoy the effect of reducing electrical resistance and suppressing charging. The carbon black is not particularly limited. For example, high, medium or low structure SAF, ISAF, IISAF, N339, HAF, FEF, GPF, SRF grade carbon black, particularly SAF, ISAF, IISAF, N339, HAF, Preferably, FEF grade carbon black is used. The nitrogen adsorption specific surface area (N ₂ SA, measured in accordance with JIS K 6217-2: 2001) is preferably 30 to 250 m ² / g. This carbon black may be used individually by 1 type, and may be used in combination of 2 or more type. In the present invention, carbon black is not included in the inorganic filler (B).

  In the present invention, the inorganic filler (B) is preferably used in an amount of 20 to 120 parts by mass with respect to 100 parts by mass of the rubber component (A). If it is 20 mass parts or more, it is preferable from a viewpoint of ensuring wet performance, and if it is 120 mass parts or less, it is preferable from a viewpoint of rolling resistance reduction. Furthermore, it is more preferable to use 30-100 mass parts.

  Moreover, in this invention, it is preferable to use 20-150 mass parts of fillers with respect to 100 mass parts of rubber components (A). If it is 20 mass parts or more, it is preferable from a viewpoint of the reinforcement property improvement of a rubber composition, and if it is 150 mass parts or less, it is preferable from a viewpoint of rolling resistance reduction.

  In the filler of the present invention, the inorganic filler (B) is preferably 30% by mass or more from the viewpoint of achieving both wet performance and rolling resistance, more preferably 40% by mass or more, and 70% by mass or more. More preferably. In addition, when using a silica as an inorganic filler (B), it is preferable that a silica is 30 mass% or more in the said filler, and it is more preferable that it is 35 mass% or more.

<Amino acid having sulfur atom (D)>
In the present invention, the amino acid means one or more amino groups (-NRR ′ group in one molecule. Here, R and R ′ are each independently a hydrogen atom or a monovalent organic group. (Preferably represents a hydrocarbon group, more preferably an alkyl group) and / or an imino group (= NR ″ or> NR ″. Here, R ″ represents a hydrogen atom or a monovalent group. The organic group is preferably an organic compound having an organic group (preferably a hydrocarbon group, more preferably an alkyl group), and one or more carboxy groups. Alternatively, the imino group and the carboxy group may be bonded to the same carbon atom or may be bonded to different carbon atoms, and the different carbon atoms may be adjacent carbon atoms. Even so Stone, or may be a carbon atom which is not adjacent. However, the amino acids used in the present invention are those having a sulfur atom.

  When the enantiomer exists about the amino acid (D) which has a sulfur atom of this invention, the enantiomer can also be used. One of the amino acids in the enantiomeric relationship may be used, the other may be used, or both may be used in combination. Moreover, about the amino acid (D) which has a sulfur atom of this invention, when a diastereomer exists, the diastereomer can also be used. Any one of the diastereomeric amino acids may be used, or two or more amino acids may be used in combination. The amino acid (D) having a sulfur atom of the present invention can also be used in the form of a salt. Examples of the salt form include metal salts such as lithium salt, sodium salt, potassium salt, magnesium salt, calcium salt, and barium salt; inorganic acid salts such as hydrochloride and nitrate; aliphatic carboxylates such as acetate; An aromatic carboxylate such as o-acetylsalicylate; an aromatic sulfonate such as p-toluenesulfonate; and the like. Furthermore, the amino acid can also be used in the form of an ester with an alcohol. When the amino acid (D) having a sulfur atom of the present invention has a hydroxyl group, it can be used in the form of an ester with an oxo acid such as phosphoric acid. Examples of such phosphates of amino acids include O-phosphoserine. In addition, the amino acid (D) having a sulfur atom and salts and esters thereof of the present invention can also be used in the form of a hydrate.

  Preferable examples of the amino acid (D) having a sulfur atom of the present invention include (1) an amino acid having a disulfide bond, (2) an amino acid having a mercapto group, and (3) an amino acid having a monosulfide bond. . Specific examples of these amino acids (D) include L-cystine as an example of (1), L-cysteine as an example of (2), and L-methionine as an example of (3).

  In addition to these, α-amino acids may be modified so as to correspond to the above (1) to (3). Examples of the α-amino acid in this case include glycine, L-alanine, L-arginine, L-asparagine, L-aspartic acid, L-glutamine, L-glutamic acid, L-histidine, L-isoleucine, L-leucine, L-lysine, L-phenylalanine, L-proline, L-serine, L-threonine, L-tryptophan, L-tyrosine, L-valine, L-pyrrolysine, L-selenocysteine, L-hydroxylysine, L-hydroxyproline , O-phospho-L-serine, thyroxine, L-pyroglutamic acid, L-citrulline, L-ornithine and the like.

  In this invention, the amino acid (D) which has a sulfur atom can be used individually by 1 type, or can also use 2 or more types together.

  It is preferable that the compounding quantity of the amino acid (D) which has a sulfur atom used by this invention is 0.05-10 mass parts with respect to 100 mass parts of rubber components, and it is 0.1-6 mass parts. More preferably, it is 0.2-2 parts by mass. If the addition amount is less than 0.05 parts by mass, it is difficult to obtain the intended effect of the present invention. If the addition amount exceeds 10 parts by mass, the cost tends to increase unnecessarily.

  In the present invention, the number of molecules (number of moles) of the amino acid (D) having a sulfur atom in the rubber composition in the first stage of kneading is 0.1 to 1.0 of the number of molecules of the silane coupling agent (C). It is preferable that it is 2 times, More preferably, it is 0.2 to 0.8 times, More preferably, it is 0.3 to 0.7 times. When the number of molecules (number of moles) of the amino acid (D) having a sulfur atom is less than 0.1 times, there is a tendency that the predetermined effect of the present invention is difficult to be obtained. The effect may not be seen and the cost may increase unnecessarily.

<Other chemicals>
In the production method of the present invention, in addition to the above-mentioned chemicals, chemicals usually blended in this field, such as oil, wax, anti-aging agent, organic acid compounds such as stearic acid, zinc oxide, etc., sulfur and vulcanized Vulcanizing chemicals such as accelerators can be appropriately blended.

(Organic acid compound (E))
As the organic acid compound (E) blended in the rubber composition according to the present invention, stearic acid, palmitic acid, myristic acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, capric acid, pelargonic acid, caprylic acid, Saturated and unsaturated fatty acids such as enanthic acid, caproic acid, oleic acid, vaccenic acid, linoleic acid, linolenic acid and nervonic acid, organic acids such as resin acids such as rosin acid and modified rosin acid, the saturated fatty acid and the unsaturated fatty acid Examples include saturated fatty acids and esters of resin acids.

  In the production method of the present invention, the number of molecules (number of moles) of the organic acid compound in the rubber composition in the first stage of kneading is 1.5 that is the number of molecules (number of moles) of the amino acid (D) having a sulfur atom. It is preferable that it is less than 2 times. It is for suppressing suitably that the activity improvement effect of the coupling function by the amino acid (D) mixing | blending which has a sulfur atom reduces. In the present invention, since it is necessary to sufficiently exhibit the function of the organic acid compound as a vulcanization acceleration aid, 50 mol% or more in the organic acid compound contained in the rubber composition in the first stage of kneading is contained. Stearic acid is preferred. When the rubber component (A) contains at least one selected from an emulsion-polymerized styrene-butadiene copolymer and natural rubber, the organic acid compound (E) contained in the rubber composition in the first stage of kneading It is preferable that 50 mol% or more is at least one compound selected from rosin acid and fatty acid contained in at least one selected from the emulsion-polymerized styrene-butadiene copolymer and the natural rubber. The rosin acid (including modified rosin acid) and the fatty acid contained in the emulsion-polymerized styrene-butadiene copolymer are derived from an emulsifier necessary for polymerizing the emulsion-polymerized styrene-butadiene copolymer. Natural rubber usually contains a small amount of fatty acid.

  In the production method of the rubber composition of the present invention, the various compounding agents such as vulcanization activator such as zinc white, anti-aging agent and the like, which are usually compounded in the rubber composition, are used in the first stage or the final stage of kneading as required. It is kneaded in a stage or an intermediate stage between the first stage and the final stage. As a kneading apparatus in the production method of the present invention, a Banbury mixer, a roll, an intensive mixer, a kneader, a twin screw extruder, or the like is used.

<Pneumatic tire>
When used in a tire, the rubber composition of the present invention can be produced as a tire by an ordinary method. That is, if necessary, a mixture containing the above ingredients is kneaded, extruded in accordance with the shape of each member of the tire at an unvulcanized stage, and molded on a tire molding machine by a normal method. Thus, an unvulcanized tire is formed. A tire can be obtained by heating and pressurizing the unvulcanized tire in a vulcanizer, and air can be put into the tire to obtain a pneumatic tire.

  In the present specification, unless otherwise specified, the hydrocarbon group (alkyl group, alkenyl group, alkynyl, etc.) preferably has 1 to 20, more preferably 1 to 10, more preferably 1 to 4, most preferably. Preferably it is 1.

  The present invention will be described based on examples, but the present invention is not limited to the examples.

  The various chemicals used in the present specification are collectively shown below. Various chemicals were purified according to conventional methods as needed.

<Various chemicals used in the production of rubber composition>
NR (natural rubber): RSS # 3
SBR1 (styrene butadiene rubber): Nipol NS116R (solution polymerized SBR, bound styrene content: 22% by mass, vinyl bond content: 65% by mass, Tg = −25 ° C.) manufactured by Nippon Zeon Co., Ltd.
SBR2 (styrene butadiene rubber): SLR6430 (high styrene, linear, polymer type non-modified SBR manufactured by Dow Co., Ltd .: Bonded styrene content: 40 mass%, vinyl content: 14 mass%, Mw: 2 million, Mn: 1.9 million, Mw / Mn = 1.05)
BR1 (butadiene rubber): BR150B from Ube Industries, Ltd. (Cis 1,4 bond amount = 97 mass%, ML _{1 + 4} (100 ° C.) = 40, 5% toluene solution viscosity at 25 ° C. = 48, Mw / Mn = 3.3)
BR2 (butadiene rubber): BR730 manufactured by JSR Corporation (high molecular weight high cis BR synthesized with Nd catalyst. Cis content: 97% by mass, trans content: 2% by mass, vinyl content: 1% by mass, Mw = 60 10,000, Mn = 300,000, Tcp = 190, ML _{1 + 4} (100 ° C.) = 51)
Silica 1: Ultrasil VN3 (N ₂ SA: 170 m ² / g) manufactured by Evonik Degussa
Silica 2: Zeosil Premium 200 MP manufactured by Rhodia (CTAB specific surface area: 200 m ² / g, BET specific surface area: 220 m ² / g, average primary particle size: 10 nm, aggregate size: 65 nm)
Silane coupling agent 1: Si75 manufactured by Evonik Degussa (bis (3-triethoxysilylpropyl) polysulfide having an average number of S in one molecule of 2.4)
Silane coupling agent 2: NXT Low-V Silane (compound represented by the above general formula (V)) manufactured by Momentive Performance Materials
Silane coupling agent 3: NXT-Z45 manufactured by Momentive Performance Materials (a compound in which x: y molar ratio is 55:45 in the above general formula (VII))
Silane coupling agent 4: Si363 (compound shown by the following formula) manufactured by Evonik Degussa

Silane coupling agent 5: Si69 (bis (3-triethoxysilylpropyl) tetrasulfide, molecular weight = 539) manufactured by Evonik Degussa
Carbon black: N110 manufactured by Showa Cabot Co., Ltd. (N ₂ SA: 130 m ² / g)
Oil: X-140 manufactured by Japan Energy Co., Ltd.
Wax: Sunnock wax manufactured by Ouchi Shinsei Chemical Industry Co., Ltd .: Antigen 6C (N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine) manufactured by Sumitomo Chemical Co., Ltd.
Stearic acid: Tungsten zinc oxide manufactured by NOF Corporation: Zinc Hua 1 manufactured by Mitsui Kinzoku Kogyo Co., Ltd. No. 1 amino acid having sulfur atom 1: Amino acid having L-cystine sulfur atom 2: L-cysteine having sulfur atom Amino acid 3: L-methionine sulfur: Powder sulfur vulcanization accelerator manufactured by Tsurumi Chemical Co., Ltd. 1: Noxeller NS (N-tert-butyl-2-benzothiazolylsulfene manufactured by Ouchi Shinsei Chemical Co., Ltd.) Amide)
Vulcanization accelerator 2: Noxeller D (N, N'-diphenylguanidine) manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.

<Manufacture of rubber composition for tire>
(First stage of kneading)
Each chemical was kneaded for 5 minutes using a 1.7L Banbury mixer manufactured by Kobe Steel, Ltd. according to the formulation (shown in all parts by mass) in the X-kneading of each table, and the discharge temperature Was set to 160 ° C. to obtain a kneaded product.
Next, except Examples 1-13, 17-21, and Comparative Examples 1-2, each chemical | medical agent was added to the obtained kneaded material according to the mixing | blending prescription shown to Y kneading | mixing of each table | surface, Kobe Co., Ltd. A kneaded product was obtained by kneading for 4 minutes using a 1.7 L Banbury mixer manufactured by Steel Works and setting the discharge temperature to 155 ° C.
In each table, “time from adding silane coupling agent to adding amino acid having S atom (S)” and “temperature of rubber composition when adding amino acid having S atom” (° C.) "Represents these times and temperatures in X-kneading for Examples 1-13 and 17-21, and represents these times and temperatures in Y-kneading for Examples 22-43.

(Final stage of kneading)
Furthermore, according to the compounding prescription shown in the final stage (finish kneading) of each table, each chemical is added to the obtained kneaded product and kneaded at 80 ° C. for 5 minutes using an open roll, and unvulcanized. A rubber composition was obtained.
The obtained unvulcanized rubber composition was press vulcanized with a 0.5 mm thick mold at 170 ° C. for 20 minutes to obtain a vulcanized rubber composition.

(Processability index)
About each unvulcanized rubber composition, the smoothness of the rubber sheet after roll processing was visually sensory-evaluated. Evaluation was carried out in five stages with respect to the following items, with the evaluation value of the reference comparative example (see below for the reference comparative example) set to 3. The average value is defined as the smoothness of the rubber sheet. A larger number indicates better.
Evaluation item: Surface / edge smoothness

(Low fuel consumption index)
A test piece was cut out from each vulcanized rubber composition and vulcanized rubber at 30 ° C. under the conditions of an initial strain of 10%, a dynamic strain of 2%, and a frequency of 10 Hz using a viscoelastic spectrometer manufactured by Ueshima Seisakusho. The loss tangent (tan δ) of the sheet was measured, the fuel efficiency index of the reference comparative example was taken as 100, and the tan δ of each formulation was displayed as an index according to the following calculation formula. The larger the fuel efficiency index, the better the fuel efficiency.

(Low fuel efficiency index) = (tan δ of reference comparative example) ÷ (tan δ of each formulation) × 100

(Abrasion resistance index)
A test piece was cut out from each vulcanized rubber composition, and the volume of each vulcanized rubber composition was measured using a LAT tester (Laboratory Abbreviation and Skid Tester) under the conditions of a load of 50 N, a speed of 20 km / h, and a slip angle of 5 °. The amount of loss was measured. The abrasion resistance index of the reference comparative example was set to 100, and the volume loss amount of each formulation was displayed as an index according to the following calculation formula. The higher the wear resistance index, the better the wear resistance.

(Abrasion resistance index) = (volume loss amount of reference comparative example) ÷ (volume loss amount of each formulation) × 100

  In Table 1 (Examples 1 to 21 and Comparative Examples 1 to 6), Comparative Example 1 was used. In Table 2 (Examples 22 to 24 and Comparative Examples 7 to 10), Comparative Example 7 was set to Table 3 (implemented). In Examples 25-28 and Comparative Examples 11-15, Comparative Example 11 was used. In Table 4 (Examples 29-31, Comparative Examples 16-19), Comparative Example 16 was shown in Table 5 (Examples 32-34, Comparative Example). In Examples 20 to 24), Comparative Example 20 is used. In Table 6 (Examples 35 to 37, Comparative Examples 25 to 29), Comparative Example 25 is used, and in Table 7 (Examples 38 to 40, Comparative Examples 30 to 33). Comparative Example 30 was used as a reference comparative example in Table 8 (Examples 41 to 43, Comparative Examples 34 to 38).

  The above results are shown in Tables 1-8.

  According to the present invention, a method for producing a tire rubber composition having improved workability, wear resistance, and fuel consumption characteristics in a well-balanced manner, and an air produced using the tire rubber composition produced by the production method An inset tire can be provided.

Claims (10)

Includes rubber component (A) containing natural rubber and / or synthetic diene rubber, filler containing inorganic filler (B) containing at least silica, silane coupling agent (C) and amino acid (D) having sulfur atom A method for producing a rubber composition comprising:
The kneading process is composed of at least two stages of a first stage of kneading not containing a vulcanizing chemical and a final stage of kneading containing a vulcanizing chemical,
In the first stage of kneading, all or a part of the silane coupling agent (C) is added and kneaded at the same time or after all or part of the rubber component (A) and the inorganic filler (B) are kneaded. In addition, a step of adding and kneading the amino acid (D) having the sulfur atom at the same time as or after adding all or a part of the silane coupling agent (C) is performed. A method for producing a rubber composition for a tire. The amino acid (D) having a sulfur atom is at least one selected from the group consisting of (1) an amino acid having a disulfide bond, (2) an amino acid having a mercapto group, and (3) an amino acid having a monosulfide bond. The manufacturing method of the rubber composition for tires of Claim 1. The method for producing a tire rubber composition according to claim 1 or 2, wherein in the first stage of kneading, the amino acid (D) having a sulfur atom is added when the temperature of the rubber composition reaches 75 to 180 ° C. In the first stage of kneading, after the addition of the silane coupling agent (C) to the rubber component (A), the time until the amino acid (D) having a sulfur atom is added is within 180 seconds. The manufacturing method of the rubber composition for tires of any one of claim | item 1 -3. The tire according to any one of claims 1 to 4, wherein the silane coupling agent (C) is at least one selected from the group consisting of compounds represented by the following general formulas (I) to (IV). For producing a rubber composition for use.

(In the formula, when there are a plurality of R ^{1 s} , they may be the same or different, and each of them may be a linear cyclic or branched alkyl group having 1 to 8 carbon atoms, or a linear or branched alkoxy group having 2 to 8 carbon atoms. An alkyl group or a hydrogen atom, and when there are a plurality of R ^{2 s} , they may be the same or different and each is a linear, cyclic or branched alkyl group having 1 to 8 carbon atoms, and when there are a plurality of R ³ May be the same or different and each is a linear or branched alkylene group having 1 to 8 carbon atoms.
a is 2 to 6 as an average value, p and r may be the same or different, and each is 0 to 3 as an average value. However, both p and r are not 3. )

(Wherein, R ⁴ is ^{-Cl, -Br, R 9 O-,} R 9 C (= O) O-, R 9 R 10 C = NO-, R 9 R 10 CNO-, R 9 R 10 N- , And-(OSiR ⁹ R ¹⁰ ) _h (OSiR ⁹ R ¹⁰ R ¹¹ ) are each a monovalent group (R ⁹ , R ¹⁰ and R ¹¹ are each a hydrogen atom or a monovalent carbon atom having 1 to 18 carbon atoms. H is an average value of 1 to 4, and R ⁵ is R ⁴ , a hydrogen atom or a monovalent hydrocarbon group having 1 to 18 carbon atoms, R ⁶ is R ⁴ , R ⁵ , a hydrogen atom or a monovalent group represented by — [O (R ¹² O) _j ] _0.5 (R ¹² is an alkylene group having 1 to 18 carbon atoms, j is an integer of 1 to 4). , R ⁷ is a divalent hydrocarbon group having 1 to 18 carbon atoms, and R ⁸ is a monovalent hydrocarbon group having 1 to 18 carbon atoms, x, y and z are x + y + 2z = 3, 0 ≦ x ≦ 3, 0 ≦ y ≦ Are numbers satisfying the relation of 0 ≦ z ≦ 1.)

(In the formula, when there are a plurality of R ^{13 s} , they may be the same or different, and each of them may be a linear, cyclic or branched alkyl group having 1 to 8 carbon atoms, a linear or branched alkyl group having 2 to 8 carbon atoms. An alkoxyalkyl group or a hydrogen atom, and when there are a plurality of R ^{14 s} , they may be the same or different, each being a linear, cyclic or branched alkyl group having 1 to 8 carbon atoms, and a plurality of R ^{15 s.} In some cases, they may be the same or different, and each is a linear or branched alkylene group having 1 to 8 carbon atoms.
R ¹⁶ is any one of the general formulas (—S—R ¹⁷ —S—), (—R ¹⁸ —S _m1 —R ¹⁹ —) and (—R ²⁰ —S _m2 —R ²¹ —S _m3 —R ²² —). Divalent groups (R ^{17 to} R ²² are each a divalent hydrocarbon group having 1 to 20 carbon atoms, a divalent aromatic group, or a divalent organic group containing a hetero element other than sulfur and oxygen. , M1, m2 and m3 are each an average value of 1 or more and less than 4, and a plurality of k may be the same or different, each being an average value of 1 to 6, and s and t are each an average The value is 0-3. However, both s and t are not 3. )

(In the formula, R ²³ is a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, and a plurality of Gs may be the same or different, and each is an alkanediyl group or alkenediyl group having 1 to 9 carbon atoms. , and the the plurality of Z ^a may be the same or different, is a functional group capable of binding with each of two silicon atoms, and _{[-0-] 0.5, [- 0} -G-] 0.5 and [ —O—G—O—] is a functional group selected from _0.5 , and a plurality of Z ^b may be the same or different, each being a functional group capable of bonding to two silicon atoms, and [—O -G-O-] is a functional group represented by _0.5 , and a plurality of Z ^c may be the same or different, and each represents —Cl, —Br, —OR ^a , R ^a C (═O) O—, ^{R a R b C = NO-,} R a R b N-, R a - and HO-G-O- (G above table Consistent with a functional group selected from.), R ^a and R ^b are each a straight-chain having 1 to 20 carbon atoms, branched or cyclic alkyl group .m, n, u, v and w are 1 ≦ m ≦ 20, 0 ≦ n ≦ 20, 0 ≦ u ≦ 3, 0 ≦ v ≦ 2, 0 ≦ w ≦ 1, and (u / 2) + v + 2w = 2 or 3. A part is plural In some cases, each of Z ^a _u , Z ^b _v and Z ^c _w in a plurality of A parts may be the same or different. When there are a plurality of B parts, Z ^a _u and Z ^b _{v in} ^a plurality of B parts And Z ^c _w may be the same or different.) The manufacturing method of the rubber composition for tires of Claim 5 whose silane coupling agent (C) is a compound represented by general formula (I). The method for producing a rubber composition for a tire according to any one of claims 1 to 6, wherein the content of the inorganic filler (B) in the filler is 30% by mass or more. The number of molecules of the amino acid (D) having a sulfur atom in the rubber composition in the first stage of kneading is 0.1 to 1.0 times the number of molecules of the silane coupling agent (C). 8. A method for producing a rubber composition for a tire according to any one of 7 above. The manufacturing method of the rubber composition for tires of any one of Claims 1-8 whose 50 mol% or more in the organic acid compound contained in the rubber composition in the 1st step of kneading | mixing is a stearic acid. The pneumatic tire produced using the rubber composition for tires manufactured by the manufacturing method of any one of Claims 1-9.