JP3570064B2 - Rubber composition - Google Patents

Description

式（１）、（２）中、Ｒはメチル基又はエチル基を表し、ａは１〜６の整数を表し、ｂは１〜６の整数を表し、Ｚはメルカプト基、エポキシ基、ビニル基又はアミノ基を表す。

式（３）中、Ａ及びＢは、独立に、水素原子、水酸基又はビニル基を表し、ｌ及びｍは、独立に、１〜１００の整数を表し、ｊ及びｋは、独立に、０〜５０の整数を表す。Ｘ ₁ 〜Ｘ ₆ は、独立に、フェニル基、ビニル基又は下記化学式（４）で表される基を表す。
−ＣｎＨ ₂ ｎＹ （４）
式（４）中、Ｙは水素原子又は水酸基を表し、ｎは０〜５０の整数を表す。

式（５）中、ｐは１〜２００の整数を表す。
【０００６】
【発明の実施の形態】
本発明の（Ａ）成分は溶液重合ジエン系ゴムである。溶液重合ジエン系ゴムの具体例としては、溶液重合ブタジエンゴム（ＢＲ）、溶液重合スチレン−ブタジエンゴム（ＳＢＲ）、イソプレンゴム（ＩＲ）などをあげることができる。タイヤ用途という観点からは、溶液重合ブタジエンゴム及び溶液重合スチレン−ブタジエンゴムが好ましい。本発明を実施するにあたって、溶液重合ジエン系ゴムの詳細構造は特に制限されない。なお、これらのゴムは、その一種を単独で用いてもよく、又は二種以上を併用してもよい。
【０００７】
本発明の（Ｂ）成分はシリカである。シリカには、表面水酸基濃度、ｐＨ、粒子性状の違いによる様々な種類がある。本発明において使用されるシリカは特に限定されないが、ＤＢＡ（ジブチルアミン）吸着量が１００〜４００（ｍｍｏｌ／ｋｇ）、ＢＥＴ比表面積が５０〜３００（ｍ^２ ／ｇ）、ＰＨが５〜１２のものが好ましい。
【０００８】
本発明のゴム組成における（Ｂ）成分の含有量は、（Ａ）成分１００重量部あたり５〜１００重量部、好ましくは３０〜９０重量部である。（Ｂ）成分が過少であると加硫物の機械的強度が低下し、一方（Ｂ）成分が過多であると混練加工性や加硫物の機械的強度が低下する。
【０００９】
本発明の（Ｃ）成分は、下記化学式（１）又は（２）で表される少なくとも一種であるシランカップリング剤である。これらの化合物は、その一種を単独で用いてもよく、又は二種以上を併用してもよい。

式（１）、（２）中、Ｒはメチル基又はエチル基を表し、ａは１〜６の整数を表し、ｂは１〜６の整数を表し、Ｚはメルカプト基、エポキシ基、ビニル基又はアミノ基を表す。
【００１１】
式（１）、（２）中、Ｒはメチル基又はエチル基を表し、エチル基であることが好ましい。ａは１〜８の整数を表し、２〜５の整数であることが好ましい。ｂは１〜６の整数を表し、２〜５の整数であることが好ましい。Ｚはメルカプト基、エポキシ基、ビニル基又はアミノ基を表す。
【００１２】
上記化学式（１）で表される化合物の例としては、ビス−（トリメトキシシリルメチル）ジスルフィド、ビス−（２−トリメトキシシリルエチル）ジスルフィド、ビス−（２−トリメトキシシリルエチル）テトラスルフィド、ビス−（２−トリメトキシシリルエチル）ペンタスルフィド、ビス−（２−トリメトキシシリルエチル）オクタスルフィド、ビス−（３−トリメトキシシリルプロピル）ジスルフィド、ビス−（３−トリメトキシシリルプロピル）トリスルフィド、ビス−（３−トリメトキシシリルプロピル）テトラスルフィド、ビス−（３−トリメトキシシリルプロピル）ペンタスルフィド、ビス−（３−トリメトキシシリルプロピル）オクタスルフィド、ビス−（４−トリメトキシシリルブチル）テトラスルフィド及び上記の化合物のメトキシ基がエトキシ基に置換された化合物などがあげられる。
【００１３】
上記化学式（２）で表される化合物の例としては、１−メルカプト−２−トリメトキシシリルエタン、１−メルカプト−３−トリメトキシシリルプロパン、１−メルカプト−４−トリメトキシシリルブタン、１，２−エポキシ−３−トリメトキシシリルプロパン、１，２−エポキシ−４−トリメトキシシリルブタン、３−トリメトキシシリル−１−プロペン、４−トリメトキシシリル−１−ブテン、１−ジメチルアミノ−２−トリメトキシシリルエタン、１−ジメチルアミノ−３−トリメトキシシリルプロパン、１−ジメチルアミノ−４−トリメトキシシリルブタン及び上記の化合物のメトキシ基がエトキシ基に置換された化合物などがあげられる。
【００１４】
化学式（１）又は化学式（２）で表される化合物のうち、特に好ましいものとしては、ビス−（３−トリエトキシシリルプロピル）トリスルフィド、ビス−（３−トリエトキシシリルプロピル）テトラスルフィド及びビス−（３−トリエトキシシリルプロピル）ペンタスルフィドをあげることができる。
【００１５】
本発明のゴム組成における（Ｃ）成分の含有量は、（Ａ）成分１００重量部あたり１〜１５重量部、好ましくは２〜１０重量部である。（Ｃ）成分が過少であると加硫速度及び加硫物の機械的強度が低下し、一方（Ｃ）成分が過多であると機械的強度の低下及び生産コストの増加を招く。なお、（Ｃ）成分として二種以上の化合物を併用する場合の上記含有量は、（Ｃ）成分として用いたすべての種類の化合物の総量を基準とする。
【００１６】
本発明の（Ｄ）成分は、下式（３）で表わされる水酸基を有する低分子有機シロキサン化合物又は下記式（５）で表される直鎖状の両端ジメチルポリジメチルシロキサンである。

式（３）中、Ａ及びＢは、独立に、水素原子、水酸基又はビニル基を表し、ｌ及びｍは、独立に、１〜１００の整数を表し、ｊ及びｋは、独立に、０〜５０の整数を表す。Ｘ ₁ 〜Ｘ ₆ は、独立に、フェニル基、ビニル基又は下記化学式（４）で表される基を表す。
−ＣｎＨ ₂ ｎＹ （４）
式（４）中、Ｙは水素原子又は水酸基を表し、ｎは０〜５０の整数を表す。

式（５）中、ｐは１〜２００の整数を表す。
ここで、低分子量とは、数平均分子量で１００〜１００００程度をいう。
【００１９】
式（３）中、Ａ及びＢは、独立に、水素原子、水酸基又はビニル基を表す。なお、加硫速度及び加硫物の機械的強度の増加の観点から好ましくは水酸基であり、更に好ましくはＡ、Ｂ共に水酸基である。ｌ及びｍは、独立に、１〜１００の整数を表す。なお、加硫速度及び加硫物の機械的強度の増加並びに混練加工性の向上の観点から好ましくは１〜５０、更に好ましくは２〜１０である。ｊ及びｋは、独立に、０〜５０の整数を表す。なお、加硫速度及び加硫物の機械的強度の増加並びに混練加工性の向上の観点から好ましくは０〜２０、更に好ましくは０である。Ｘ_１ 〜Ｘ_６ は、独立に、フェニル基、ビニル基又は下記化学式（４）で表される基を表す。
【００２０】
−ＣｎＨ_２ ｎＹ （４）
【００２１】
式（４）中、Ｙは水素原子又は水酸基を表し、ｎは０〜５０の整数を表す。なお、加硫速度及び加硫物の機械的強度の増加並びに混練加工性の向上の観点から好ましいｎは０〜２０の整数であり、更に好ましくは０又は１である。特に好ましいＸ_１ 〜Ｘ_６ はフェニル基、ビニル基、メチル基及び水酸基である。
【００２２】
化学式（３）で表される化合物の例としては下記の化合物をあげることができる。
【００２３】

【００２６】
式（５）中、ｐは１〜２００の整数を表す。なお、加硫速度及び加硫物の機械的強度の増加並びに混練加工性の向上の観点から好ましいｐは２〜１００の整数であり、更に好ましくは４〜５０の整数である。
【００２７】
本発明においては、（Ｄ）成分として、上記の化合物の一種を単独で用いてもよく、又は二種以上を併用してもよい。なお、転動抵抗の低減及び加硫速度の増加の観点からは、前記化学式（３）の水酸基を有する化合物がより好ましい。
【００２８】
本発明のゴム組成における（Ｄ）成分の含有量は、（Ａ）成分１００重量部あたり１〜２０重量部、好ましくは２〜１０重量部である。（Ｄ）成分が過少であると加硫速度の増加、加硫物の機械的強度の増加、転動抵抗の低減の効果が小さくなり、一方（Ｄ）成分が過多であると加硫物の機械的強度が低下する。なお、（Ｄ）成分として二種以上の化合物を併用する場合の上記含有量は、（Ｄ）成分として用いたすべての種類の化合物の総量を基準とする。
【００２９】
本発明のゴム組成物は、上記の（Ａ）成分〜（Ｄ）成分の所定量を混練時の最高温度を２００℃以下に制御しながら混練することにより得られる。（Ｃ）成分と（Ｄ）成分の併用は必須であり、本発明に依らず、（Ｃ）成分と（Ｄ）成分のいずれかを使用しない場合は、加硫速度、混練加工性、加硫物の機械的強度及び転動抵抗において、著しい特性悪化を生じる。
【００３０】
混練は、たとえばロール、バンバリーなどの通常の混練機を用い、各成分が均一に混合されるまで混練すればよいが、混練時の最高温度は２００℃以下、好ましくは１００〜１６０℃である。該温度が低過ぎると加硫物の機械的強度が低下し、一方該温度が高過ぎるとゴムの劣化を招く。なお、混練にあたっては、本発明の必須成分である（Ａ）成分〜（Ｄ）成分に加えて、天然ゴム、乳化重合ブタジエンゴム、乳化重合スチレン−ブタジエンゴムなどの一般的汎用ゴム、カーボンブラック、酸化防止剤、加硫促進剤、加工助剤、ステアリン酸、補強剤、充填剤、可塑剤、軟化剤など添加してもよい。
【００３１】
本発明のゴム組成物は、各種自動車部品、各種工業部品、建築材料などに利用され得るが、機械的強度及び耐摩耗性に優れ、転動抵抗が低いという優れた特徴を生かして、タイヤ用途に特に最適に利用される。
【００３２】
【実施例】
次に、実施例により本発明を説明する。
実施例１〜９及び比較例１〜６
表１に示す成分及びＸ−１４０（共同石油社製 オイル）５０重量部及びダイヤブラックＮ３３９（三菱化学社製 ＨＡＦカーボンブラック）６．４重量部を、１１０℃に調整した１５００ｍｌのバンバリーミキサーに同時に投入し、ローター回転数１５０ｒｐｍで５分間混練した。次に、８５℃に調整した８インチのオープンロールを用いて、共通配合として、サンノックＮ（大内新興化学社製老化防止剤）１．５重量部、アンチゲン３Ｃ（住友化学工業社製 老化防止剤）１．５重量部、酸化亜鉛２重量部及びステアリン酸２重量部を添加して混練した。更に、４０℃に調整した８インチのオープンロールを用いて、Ｓｏｘ ＣＺ（住友化学工業社製 加硫促進剤）１重量部、Ｓｏｘ Ｄ（住友化学工業社製 加硫促進剤）１重量部及び硫黄１．４重量部を添加・混練し、コンパウンドを得た。次に、該コンパウンドを１６０℃×２０分間でプレス加硫し、加硫ゴム組成物を得た。下記の方法に従い、評価を行った。結果を表１に示した。
【００３３】
比較例７
（Ｂ）成分と（Ｄ）成分を予め混合し、２５０℃下で１時間処理したものを用いた以外は、実施例１に準拠して行った。結果を表３に示す。
【００３４】
比較例８
１４０℃に調整したバンバリーミキサーを使用して、混練時の最高温度を２１０℃とし、１０分間混練した以外は実施例１に準拠して行った、ゲル化した組成物しか得られず、評価することは不可能であった。
【００３５】
〔評価方法〕
（１）引き裂き強度、ゴム弾性（３００％モジュラス）及び加硫速度
ＪＩＳ−Ｋ−６２５２に準じて測定した。なお、引き裂き強度は、切込みなしアングル型試料を用いて測定した。
（２）耐摩耗性（摩耗損量）
アクロン耐摩耗試験機を用い、ＪＩＳ−Ｋ−６２６４に準じて測定した。
（３）転動抵抗（ｔａｎδ）指数
東洋精機社製レオログラフソリッドＬ１Ｒを用い、周波数１０Ｈｚ、初期歪１０％、振幅±０．２５％、昇温速度２℃／分の条件で測定することによりｔａｎδ温度分散曲線を得、この曲線から６０℃ｔａｎδ値を求めた。次に、（Ａ）成分にＡ１を使用した実施例及び比較例のｔａｎδ値は、実施例１を１００とした指数で、（Ａ）成分にＡ２を使用した実施例及び比較例のｔａｎδ値は、実施例２を１００とした指数で表した。指数の小さい程、転動抵抗が低いをことを示す。
【００３６】
【表１】

【００３７】
【表２】

【００３８】
【表３】

【００３９】
【表４】

【００４０】
＊１ （Ａ）
Ａ１：溶液重合ＳＢＲ（スチレン単位／ビニル単位 １５／４５（ｗｔ％／％））
Ａ２：溶液重合ＳＢＲ（スチレン単位／ビニル単位 ２９／４９（ｗｔ％／％））
＊２ （Ｂ）：シリカ（ＳｉＯ_２ ）（ウルトラシルＶＮ３Ｇ ユナイテッドシリカ社製）
＊３ （Ｃ）：前記化学式（１）において、Ｒ＝エチル基、ａ＝３、ｂ＝４のものを用いた。
＊４ （Ｄ）
Ｄ１：前記化学式（３）において、Ａ＝Ｂ＝水酸基、ｊ＝ｋ＝ｍ＝０、ｌ＝７、ｘ_１ ＝ｘ_２ ＝ｘ_５ ＝ｘ_６ ＝メチル基のもの（分子量＝６１１）を用いた。
Ｄ２：前記化学式（５）において、ｐ＝６のもの（信越化学工業社製 ＫＦ９６Ｌ−５、分子量＝５３３）を用いた。
Ｄ３：前記化学式（５）において、ｐ＝３４のもの（信越化学工業社製 ＫＦ９６Ｌ−５０、分子量＝２６１０）を用いた。
＊５ （Ｂ）成分と（Ｄ）成分を予め混合し、２５０℃下で１時間処理した後に用いた。
【００４１】
【発明の効果】
以上説明したとおり、本発明により、機械的強度及び耐摩耗性に優れ、転動抵抗が低く、かつ加硫速度が速いため生産効率に優れた溶液重合ゴム組成物を提供することができた。[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a rubber composition. More specifically, the present invention relates to a solution-polymerized rubber composition having excellent mechanical strength and abrasion resistance, low rolling resistance, and high production efficiency due to a high vulcanization rate.
[0002]
[Prior art]
Rubber compositions using silica are widely used in colored rubber and white rubber applications because they are easier to color than rubber compositions using carbon black, and have a temperature of room temperature or higher. Due to the characteristic that energy loss in the region is small, it is also used for tire applications and the like. However, the solution-polymerized rubber composition using silica has problems that the mechanical strength such as tear strength is insufficient and the production efficiency is low because the vulcanization rate is low.
[0003]
Japanese Patent Application Laid-Open No. Hei 6-248116 discloses a technique using silica made of an organosilicon compound and treated with a hydrophobizing agent at 250 ° C. for 1 hour, for example. However, when the composition is vulcanized rubber, there is a problem that the wear resistance is still insufficient. In addition, this method has a problem in that the production cost is high because surface-treated silica in which the silica surface is treated with a hydrophobic agent must be separately manufactured.
[0004]
[Problems to be solved by the invention]
The problem to be solved by the present invention is to provide a solution-polymerized rubber composition which is excellent in mechanical strength and abrasion resistance, has low rolling resistance, and has a high vulcanization rate and is therefore excellent in production efficiency.
[0005]
[Means for Solving the Problems]
That is, the present invention relates to 100 parts by weight of the following component (A), 5 to 100 parts by weight of component (B), 1 to 15 parts by weight of component (C) and 1 to 20 parts by weight of component (D). The present invention relates to a rubber composition obtained by kneading while controlling the temperature to 200 ° C. or lower.
(A): solution-polymerized diene rubber (B): silica (C): a silane coupling agent (D) which is at least one of the following chemical formulas (1) or (2 ): represented by the following formula (3) Or a low-molecular-weight organosiloxane compound having a hydroxyl group, or a linear double-ended dimethylpolydimethylsiloxane represented by the following formula (5):

In the formulas (1) and (2), R represents a methyl group or an ethyl group, a represents an integer of 1 to 6, b represents an integer of 1 to 6, Z represents a mercapto group, an epoxy group, or a vinyl group. Or an amino group.

In the formula (3), A and B each independently represent a hydrogen atom, a hydroxyl group or a vinyl group, l and m each independently represent an integer of 1 to 100, and j and k each independently represent 0 to 0. Represents an integer of 50. X _{1 to} X ₆ independently represent a phenyl group, a vinyl group or a group represented by the following chemical formula (4).
-CnH ₂ nY (4)
In the formula (4), Y represents a hydrogen atom or a hydroxyl group, and n represents an integer of 0 to 50.

In the formula (5), p represents an integer of 1 to 200.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
The component (A) of the present invention is a solution-polymerized diene rubber. Specific examples of the solution polymerized diene rubber include solution polymerized butadiene rubber (BR), solution polymerized styrene-butadiene rubber (SBR), and isoprene rubber (IR). From the viewpoint of tire applications, solution-polymerized butadiene rubber and solution-polymerized styrene-butadiene rubber are preferred. In carrying out the present invention, the detailed structure of the solution polymerized diene rubber is not particularly limited. These rubbers may be used alone or in a combination of two or more.
[0007]
The component (B) of the present invention is silica. There are various types of silica depending on differences in surface hydroxyl group concentration, pH, and particle properties. The silica used in the present invention is not particularly limited, but has a DBA (dibutylamine) adsorption amount of 100 to 400 (mmol / kg), a BET specific surface area of 50 to 300 (m ² / g), and a PH of 5 to 12. Are preferred.
[0008]
The content of the component (B) in the rubber composition of the present invention is 5 to 100 parts by weight, preferably 30 to 90 parts by weight, per 100 parts by weight of the component (A). If the amount of the component (B) is too small, the mechanical strength of the vulcanizate decreases, while if the amount of the component (B) is excessive, the kneading processability and the mechanical strength of the vulcanizate decrease.
[0009]
The component (C) of the present invention is at least one silane coupling agent represented by the following chemical formula (1) or (2) . These compounds may be used alone or in a combination of two or more.

In the formulas (1) and (2), R represents a methyl group or an ethyl group, a represents an integer of 1 to 6, b represents an integer of 1 to 6, Z represents a mercapto group, an epoxy group, or a vinyl group. Or an amino group.
[0011]
In the formulas (1) and (2), R represents a methyl group or an ethyl group, and is preferably an ethyl group. a represents an integer of 1 to 8, and is preferably an integer of 2 to 5. b represents an integer of 1 to 6, and is preferably an integer of 2 to 5. Z represents a mercapto group, an epoxy group, a vinyl group or an amino group.
[0012]
Examples of the compound represented by the chemical formula (1) include bis- (trimethoxysilylmethyl) disulfide, bis- (2-trimethoxysilylethyl) disulfide, bis- (2-trimethoxysilylethyl) tetrasulfide, Bis- (2-trimethoxysilylethyl) pentasulfide, bis- (2-trimethoxysilylethyl) octasulfide, bis- (3-trimethoxysilylpropyl) disulfide, bis- (3-trimethoxysilylpropyl) trisulfide , Bis- (3-trimethoxysilylpropyl) tetrasulfide, bis- (3-trimethoxysilylpropyl) pentasulfide, bis- (3-trimethoxysilylpropyl) octasulfide, bis- (4-trimethoxysilylbutyl) Tetrasulfide and the above compounds Methoxy group and compounds substituted with ethoxy group.
[0013]
Examples of the compound represented by the chemical formula (2) include 1-mercapto-2-trimethoxysilylethane, 1-mercapto-3-trimethoxysilylpropane, 1-mercapto-4-trimethoxysilylbutane, 2-epoxy-3-trimethoxysilylpropane, 1,2-epoxy-4-trimethoxysilylbutane, 3-trimethoxysilyl-1-propene, 4-trimethoxysilyl-1-butene, 1-dimethylamino-2 -Trimethoxysilylethane, 1-dimethylamino-3-trimethoxysilylpropane, 1-dimethylamino-4-trimethoxysilylbutane, and compounds in which the methoxy group of the above compound is substituted with an ethoxy group.
[0014]
Among the compounds represented by the chemical formula (1) or (2), particularly preferable compounds are bis- (3-triethoxysilylpropyl) trisulfide, bis- (3-triethoxysilylpropyl) tetrasulfide and bis- (3-triethoxysilylpropyl) tetrasulfide. -(3-triethoxysilylpropyl) pentasulfide.
[0015]
The content of the component (C) in the rubber composition of the present invention is 1 to 15 parts by weight, preferably 2 to 10 parts by weight per 100 parts by weight of the component (A). If the amount of the component (C) is too small, the vulcanization rate and the mechanical strength of the vulcanizate are reduced. On the other hand, if the amount of the component (C) is too large, the mechanical strength is reduced and the production cost is increased. The content when two or more compounds are used in combination as the component (C) is based on the total amount of all the compounds used as the component (C).
[0016]
The component (D) of the present invention is a low molecular weight organic siloxane compound having a hydroxyl group represented by the following formula (3) or a linear double-ended dimethylpolydimethylsiloxane represented by the following formula (5).

In the formula (3), A and B each independently represent a hydrogen atom, a hydroxyl group or a vinyl group, l and m each independently represent an integer of 1 to 100, and j and k each independently represent 0 to 0. Represents an integer of 50. X _{1 to} X ₆ independently represent a phenyl group, a vinyl group or a group represented by the following chemical formula (4).
-CnH ₂ nY (4)
In the formula (4), Y represents a hydrogen atom or a hydroxyl group, and n represents an integer of 0 to 50.

In the formula (5), p represents an integer of 1 to 200.
Here, the low molecular weight means a number average molecular weight of about 100 to 10,000.
[0019]
In the formula (3), A and B independently represent a hydrogen atom, a hydroxyl group or a vinyl group. In addition, from the viewpoints of increasing the vulcanization rate and the mechanical strength of the vulcanized product, a hydroxyl group is preferable, and both A and B are preferably a hydroxyl group. l and m each independently represent an integer of 1 to 100. In addition, it is preferably 1 to 50, more preferably 2 to 10, from the viewpoints of increasing the vulcanization rate and the mechanical strength of the vulcanized product and improving the kneading processability. j and k each independently represent an integer of 0 to 50. In addition, it is preferably 0 to 20, and more preferably 0, from the viewpoints of increasing the vulcanization rate and the mechanical strength of the vulcanized product and improving the kneading processability. X _{1 to} X ₆ independently represent a phenyl group, a vinyl group or a group represented by the following chemical formula (4).
[0020]
—CnH ₂ nY (4)
[0021]
In the formula (4), Y represents a hydrogen atom or a hydroxyl group, and n represents an integer of 0 to 50. In addition, n is preferably an integer of 0 to 20, more preferably 0 or 1, from the viewpoints of increasing the vulcanization rate and the mechanical strength of the vulcanizate and improving the kneading processability. Particularly preferred X _{1 to} X ₆ are a phenyl group, a vinyl group, a methyl group and a hydroxyl group.
[0022]
Examples of the compound represented by the chemical formula (3) include the following compounds.
[0023]

[0026]
In the formula (5), p represents an integer of 1 to 200. In addition, p is preferably an integer of 2 to 100, and more preferably an integer of 4 to 50, from the viewpoints of increasing the vulcanization rate, the mechanical strength of the vulcanized product, and improving the kneading processability.
[0027]
In the present invention, as the component (D), one of the above compounds may be used alone, or two or more may be used in combination. From the viewpoint of reducing rolling resistance and increasing the vulcanization rate, the compound having a hydroxyl group represented by the chemical formula (3) is more preferable.
[0028]
The content of the component (D) in the rubber composition of the present invention is 1 to 20 parts by weight, preferably 2 to 10 parts by weight, per 100 parts by weight of the component (A). If the amount of the component (D) is too small, the effect of increasing the vulcanization rate, the mechanical strength of the vulcanizate, and the effect of reducing the rolling resistance decreases. Mechanical strength decreases. The content when two or more compounds are used in combination as the component (D) is based on the total amount of all the compounds used as the component (D).
[0029]
The rubber composition of the present invention can be obtained by kneading a predetermined amount of the above components (A) to (D) while controlling the maximum temperature during kneading to 200 ° C. or lower. Combination of the components (C) and (D) is essential, and regardless of the present invention, when any of the components (C) and (D) is not used, the vulcanization rate, kneading processability, vulcanization In the mechanical strength and rolling resistance of the object, a remarkable deterioration in characteristics occurs.
[0030]
The kneading may be carried out using a usual kneader such as a roll or a Banbury until the components are uniformly mixed. The maximum temperature during kneading is 200 ° C or lower, preferably 100 to 160 ° C. If the temperature is too low, the mechanical strength of the vulcanizate will decrease, whereas if the temperature is too high, rubber will be degraded. In kneading, in addition to the essential components (A) to (D) of the present invention, general-purpose rubbers such as natural rubber, emulsion-polymerized butadiene rubber, and emulsion-polymerized styrene-butadiene rubber, carbon black, Antioxidants, vulcanization accelerators, processing aids, stearic acid, reinforcing agents, fillers, plasticizers, softeners and the like may be added.
[0031]
The rubber composition of the present invention can be used for various automobile parts, various industrial parts, building materials, etc., but has excellent mechanical strength and abrasion resistance and low rolling resistance. Especially optimally used for
[0032]
【Example】
Next, the present invention will be described with reference to examples.
Examples 1 to 9 and Comparative Examples 1 to 6
The components shown in Table 1, 50 parts by weight of X-140 (oil manufactured by Kyodo Sekiyu Co., Ltd.) and 6.4 parts by weight of Diamond Black N339 (HAF carbon black manufactured by Mitsubishi Chemical Corporation) were simultaneously placed in a 1500 ml Banbury mixer adjusted to 110 ° C. It was charged and kneaded for 5 minutes at a rotor rotation speed of 150 rpm. Then, using an 8 inch open roll adjusted to 85 ° C., 1.5 parts by weight of Sunnock N (an antiaging agent manufactured by Ouchi Shinko Chemical Co., Ltd.) and Antigen 3C (an antiaging agent manufactured by Sumitomo Chemical Co., Ltd.) Agent) 1.5 parts by weight, zinc oxide 2 parts by weight and stearic acid 2 parts by weight were added and kneaded. Furthermore, using an 8-inch open roll adjusted to 40 ° C., 1 part by weight of Sox CZ (vulcanization accelerator manufactured by Sumitomo Chemical Co., Ltd.), 1 part by weight of Sox D (vulcanization accelerator manufactured by Sumitomo Chemical Co., Ltd.) and 1.4 parts by weight of sulfur was added and kneaded to obtain a compound. Next, the compound was press-vulcanized at 160 ° C. for 20 minutes to obtain a vulcanized rubber composition. Evaluation was performed according to the following method. The results are shown in Table 1.
[0033]
Comparative Example 7
Example 1 was repeated except that the components (B) and (D) were previously mixed and treated at 250 ° C. for 1 hour. Table 3 shows the results.
[0034]
Comparative Example 8
Using a Banbury mixer adjusted to 140 ° C., the maximum temperature during kneading was set to 210 ° C., and kneading was performed according to Example 1 except that kneading was performed for 10 minutes. Only a gelled composition was obtained and evaluated. That was impossible.
[0035]
〔Evaluation method〕
(1) Tear strength, rubber elasticity (300% modulus) and vulcanization rate Measured according to JIS-K-6252. In addition, the tear strength was measured using an angle type sample having no cut.
(2) Wear resistance (wear loss)
It was measured according to JIS-K-6264 using an Akron abrasion tester.
(3) Rolling resistance (tan δ) index Measured using a rheograph solid L1R manufactured by Toyo Seiki Co., Ltd. under the conditions of a frequency of 10 Hz, an initial strain of 10%, an amplitude of ± 0.25%, and a heating rate of 2 ° C./min. To obtain a tan δ temperature dispersion curve, from which a 60 ° C. tan δ value was determined. Next, the tan δ value of Examples and Comparative Examples using A1 as the component (A) is an index with respect to Example 1 as 100, and the tan δ values of Examples and Comparative Examples using A2 as the component (A) are as follows. , And Example 2 as 100. The smaller the index, the lower the rolling resistance.
[0036]
[Table 1]

[0037]
[Table 2]

[0038]
[Table 3]

[0039]
[Table 4]

[0040]
* 1 (A)
A1: Solution polymerization SBR (styrene unit / vinyl unit 15/45 (wt% /%))
A2: Solution-polymerized SBR (styrene unit / vinyl unit 29/49 (wt% /%))
* 2 (B): Silica (SiO ₂ ) (Ultrasil VN3G United Silica)
* 3 (C): In the above chemical formula (1), R = ethyl group, a = 3 and b = 4 were used.
* 4 (D)
D1: In the above chemical formula (3), A = B = hydroxyl group, j = k = m = 0, l = 7, x ₁ = x ₂ = x ₅ = x ₆ = methyl group (molecular weight = 611) is used. Was.
D2: In the above chemical formula (5), one having p = 6 (KF96L-5, molecular weight = 533, manufactured by Shin-Etsu Chemical Co., Ltd.) was used.
D3: In the above chemical formula (5), p = 34 (KF96L-50 manufactured by Shin-Etsu Chemical Co., Ltd., molecular weight = 2610) was used.
* 5 Component (B) and component (D) were premixed and used at 250 ° C. for 1 hour.
[0041]
【The invention's effect】
As described above, according to the present invention, a solution-polymerized rubber composition having excellent mechanical strength and abrasion resistance, low rolling resistance, and high vulcanization rate and excellent production efficiency can be provided.

Claims (2)

The maximum temperature at the time of kneading 100 parts by weight of the following component (A), 5 to 100 parts by weight of the component (B), 1 to 15 parts by weight of the component (C) and 1 to 20 parts by weight of the component (D) is adjusted to 200 ° C. or less. A rubber composition obtained by kneading while controlling.
(A): solution-polymerized diene rubber (B): silica (C): a silane coupling agent (D) which is at least one of the following chemical formulas (1) or (2 ): represented by the following formula (3) Or a low-molecular-weight organosiloxane compound having a hydroxyl group, or a linear double-ended dimethylpolydimethylsiloxane represented by the following formula (5):

In the formulas (1) and (2), R represents a methyl group or an ethyl group, a represents an integer of 1 to 6, b represents an integer of 1 to 6, Z represents a mercapto group, an epoxy group, or a vinyl group. Or an amino group.

In the formula (3), A and B each independently represent a hydrogen atom, a hydroxyl group or a vinyl group, l and m each independently represent an integer of 1 to 100, and j and k each independently represent 0 to 0. Represents an integer of 50. X _{1 to} X ₆ independently represent a phenyl group, a vinyl group or a group represented by the following chemical formula (4).
-CnH ₂ nY (4)
In the formula (4), Y represents a hydrogen atom or a hydroxyl group, and n represents an integer of 0 to 50.

In the formula (5), p represents an integer of 1 to 200. The rubber composition according to claim 1, wherein the component (A) is a butadiene rubber or a styrene-butadiene rubber.