JP4721900B2 - Rubber composition for footwear - Google Patents

Description

  The present invention is a rubber-like polymer composition comprising a rubber-like polymer component and a modified polymer having a functional group-containing atomic group bonded thereto and a masterbatch component in which an inorganic filler is preliminarily mixed. The present invention relates to a novel rubber composition for footwear excellent in wear and adhesion.

Conventionally, rubbery polymers have been used as footwear materials in various footwear applications. In order to give the properties required depending on the application, a rubber composition containing a rubbery polymer as a main component and further blended with various inorganic fillers, additives, colorants and the like is used as a raw material. . In various rubber products such as footwear, a white filler such as silica is widely used as a reinforcing agent in order to improve the appearance of the product. However, when silica is used as a reinforcing filler, the affinity with rubber is low compared to conventional carbon black, so the dispersibility of silica in rubber is not always good, and this poor dispersibility results in wear resistance. Decrease, and mechanical strength tends to decrease. Therefore, in order to obtain a high reinforcing property such as carbon black, a silane coupling agent typified by bis- (3-triethoxysilylpropyl) tetrasulfide is used for compounding silica into the rubber composition, and silica is used. Improvements in dispersion are being made, increasing product costs.
The characteristics required as a shoe sole material include good wear resistance and wet skid resistance, and good adhesion to the midsole and upper.
In addition, the use of silica powder has a problem that the powder rises in the shoe manufacturing process and the workability is inferior, and moreover, in recent years, from the viewpoint of improving the working environment of a shoe factory, it is an adhesive used for shoe manufacturing. There is a growing movement to change the adhesive from organic solvent to water-based adhesive. However, the present situation is that satisfactory adhesive strength is not obtained.
As a method for improving a rubber composition, Patent Document 1 discloses a shoe sole that is excellent in colorability and wear resistance by limiting silica and a silane coupling agent and mixing a thermoplastic resin with rubber. However, a rubber composition excellent in adhesive strength when a water-based adhesive is used has not been obtained. Patent Document 2 discloses a lightweight, wear-resistant shoe sole material made of high-cis polybutadiene, styrene resin, and silica. Patent Document 3 discloses a rubber composition for footwear that improves wear resistance by using a specific polysiloxane compound. Further, Patent Document 4 discloses a rubber composition for footwear which is excellent in wear resistance and wet skid resistance by a combination of a modified polymer having a specific structure and silica, and both use an aqueous adhesive. A rubber composition having excellent adhesive strength at the time has not been obtained.
Patent Document 5 and Patent Document 6 disclose a rubber composition using a masterbatch composed of a modified polymer and a reinforcing filler, but description of adhesive strength, which is an important characteristic as a rubber composition for footwear. There is no.
Japanese Patent Laid-Open No. 62-137002 JP 2000-236905 A JP 2002-191401 A JP 2002-284931 A JP-A-8-231766 JP 2000-136269 A

（上記式（１）〜（１４）において、 Ｎは窒素原子、Ｓｉは珪素原子、Ｏは酸素原子、Ｃは炭素原子、Ｈは水素原子を表し、Ｒ^１，Ｒ^２は各々独立に水素原子又は炭素数１〜２４の炭化水素基を表し、且つ、該炭化水素基は、所望により、各々独立に、水酸基、エポキシ基、アミノ基、炭素数１〜２４の炭化水素基を有するイミノ基、シラノール基及び炭素数１〜２４のアルコキシシラン基からなる群より選ばれる少なくとも１種の官能基を有してもよく、各Ｒ^３は各々独立に炭素数１〜４８の２価の炭化水素基を表し、且つ、所望により、各々独立に、水酸基、エポキシ基、アミノ基、炭素数１〜２４の炭化水素基を有するイミノ基、シラノール基及び炭素数１〜２４のアルコキシシラン基からなる群より選ばれる少なくとも１種の官能基を有してもよく、各Ｒ^４は各々独立に水素原子又は炭素数１〜２４の炭化水素基を表す。）
８．成分（２）が、当該変性重合体と無機充填剤の混練の際に、更に当該変性重合体に結合している官能基と反応性を有する化合物（４）を当該変性重合体１００重量部に対して０．０１〜２０重量部添加して得られたマスターバッチである前項１に記載の履物用ゴム組成物。
９．成分（２）が、当該変性重合体と無機充填剤の混練物に、更に当該変性重合体に結合している官能基と反応性を有する化合物（４）を当該変性重合体１００重量部に対して０．０１〜２０重量部混練して得られたマスターバッチである前項１に記載の履物用ゴム組成物。
１０．成分（２）に使用する変性重合体が、当該変性重合体に結合している官能基と反応性を有する化合物（４）を当該変性重合体に結合している官能基１当量あたり０．３〜１０モルを用いて反応させた変性重合体である前項１に記載の履物用ゴム組成物。
１１．化合物（４）がカルボキシル基、酸無水物基、イソシアネート基、エポキシ基、シラノール基、アルコキシシラン基から選ばれる官能基を有する化合物である前項８または９に記載の履物用ゴム組成物。
１２．成分（１）ゴム状重合体：１００重量部；及び成分（２）共役ジエン系重合体又は共役ジエン系単量体とビニル芳香族炭化水素からなる共重合体又はそれらの水添物に官能基含有原子団が少なくとも１個結合している変性重合体から選ばれる少なくとも１種の変性重合体１００重量部に無機充填剤５〜３００重量部を混練して得られるマスターバッチ：１〜１５０重量部を混練する工程を含む履物用ゴム組成物の製造方法。
１３．成分（２）が無機充填剤５〜３００重量部の全量を混練機に投入して混練し、次いで変性重合体を加えて混練して得られるマスターバッチである前項１２に記載の履物用ゴム組成物の製造方法。
１４．成分（２）が無機充填剤５〜３００重量部を２回以上分割して混練機に投入して順次混練して得られるマスターバッチである前項１２に記載の履物用ゴム組成物の製造方法。
１５．無機充填剤５〜３００重量部の全量を混練機に投入して混練し、次いで変性重合体を加えて混練する前項１に記載のマスターバッチの製造方法。
１６．無機充填剤の２０〜８０重量％を予め混練機に投入して混練し、次いで変性重合体を加え混練し、更に当該無機充填剤の残量を加えて混練する前項１に記載のマスターバッチの製造方法。
特定の官能基含有原子団が結合している変性重合体と無機充填剤のマスターバッチを用いて製造した本発明の履物用ゴム組成物は、引き裂き強度、耐摩耗性、水性接着を用いた時の接着性に優れ、また、靴工場の作業環境を改善できるゴム組成物である。The present invention relates to a rubber composition obtained from a rubbery polymer and an inorganic filler, and a masterbatch of a modified polymer and an inorganic filler to which a functional group-containing atomic group is bonded is prepared. An object of the present invention is to provide a rubber composition for footwear that is excellent in tear strength, abrasion resistance, and adhesiveness, and can improve the working environment of a shoe factory by using a rubber composition containing a polymer.
The present inventors have earnestly improved the properties of a conjugated diene polymer or a copolymer comprising a vinyl aromatic hydrocarbon and a conjugated diene monomer, or a rubber composition of these hydrogenated product and inorganic filler. As a result of investigation, when a rubber composition containing a rubbery polymer and an inorganic filler is produced, tearing can be achieved by using a master batch in which a modified polymer having a specific functional group and an inorganic filler are previously kneaded. The present inventors have found that a rubber composition for footwear excellent in strength, wear resistance, and adhesiveness can be obtained, and completed the present invention.
That is, the present invention is as follows.
1. Component (1) Rubber-like polymer: 100 parts by weight; and Component (2) Conjugated diene polymer or copolymer comprising conjugated diene monomer and vinyl aromatic hydrocarbon or hydrogenated product thereof Master batch obtained by kneading 5 to 300 parts by weight of an inorganic filler with 100 parts by weight of at least one modified polymer selected from modified polymers having at least one containing atomic group bonded: 1 to 150 parts by weight A rubber composition for footwear, comprising:
2. The rubber for footwear according to the preceding item 1, wherein the component (2) is a masterbatch obtained by previously charging a total amount of 5 to 300 parts by weight of an inorganic filler into a kneader and then kneading by adding a modified polymer. Composition.
3. 2. The rubber composition for footwear according to item 1 above, wherein the component (2) is a master batch obtained by dividing 5 to 300 parts by weight of an inorganic filler twice or more, charging the mixture into a kneader and sequentially kneading.
4). The above-mentioned master batch in which component (2) is 20-80% by weight of the inorganic filler previously charged in a kneader and kneaded, then the modified polymer is added, and the remaining amount of the inorganic filler is added and kneaded. 2. The rubber composition for footwear according to 1.
5. 2. The rubber composition for footwear according to item 1, further comprising 0.1 to 150 parts by weight of an inorganic filler as component (3).
6). 2. The rubber for footwear according to item 1, wherein the functional group-containing atomic group of the modified polymer is an atomic group having at least one functional group selected from a hydroxyl group, an epoxy group, an amino group, an imino group, a silanol group, and an alkoxysilane group. Composition.
7). 2. The rubber composition for footwear according to item 1, wherein the modified polymer is a modified polymer in which at least one atomic group selected from the following formulas (1) to (14) is bonded.

(In the above formulas (1) to (14), N represents a nitrogen atom, Si represents a silicon atom, O represents an oxygen atom, C represents a carbon atom, H represents a hydrogen atom, and R ¹ and R ² are each independently a hydrogen atom. Or a hydrocarbon group having 1 to 24 carbon atoms, and the hydrocarbon groups are each independently, optionally, a hydroxyl group, an epoxy group, an amino group, an imino group having a hydrocarbon group having 1 to 24 carbon atoms, It may have at least one functional group selected from the group consisting of a silanol group and an alkoxysilane group having 1 to 24 carbon atoms, and each R ³ is independently a divalent hydrocarbon group having 1 to 48 carbon atoms. And optionally, each independently selected from the group consisting of a hydroxyl group, an epoxy group, an amino group, an imino group having a hydrocarbon group having 1 to 24 carbon atoms, a silanol group, and an alkoxysilane group having 1 to 24 carbon atoms. At least one government official It may have a group, each R ⁴ each independently represents a hydrogen atom or a C24 hydrocarbon group.)
8). When the component (2) is kneaded with the modified polymer and the inorganic filler, the compound (4) having reactivity with the functional group bonded to the modified polymer is further added to 100 parts by weight of the modified polymer. The rubber composition for footwear according to the preceding item 1, which is a masterbatch obtained by adding 0.01 to 20 parts by weight to the rubber.
9. Component (2) is a mixture of the modified polymer and inorganic filler, and further compound (4) having reactivity with the functional group bonded to the modified polymer is added to 100 parts by weight of the modified polymer. 2. A rubber composition for footwear according to item 1, which is a masterbatch obtained by kneading 0.01 to 20 parts by weight.
10. The modified polymer used for the component (2) has a compound (4) having a reactivity with the functional group bonded to the modified polymer, 0.3 per equivalent of the functional group bonded to the modified polymer. 2. The rubber composition for footwear according to item 1 above, which is a modified polymer reacted with 10 mol.
11. 10. The rubber composition for footwear according to 8 or 9 above, wherein the compound (4) is a compound having a functional group selected from a carboxyl group, an acid anhydride group, an isocyanate group, an epoxy group, a silanol group, and an alkoxysilane group.
12 Component (1) Rubber-like polymer: 100 parts by weight; and Component (2) Conjugated diene polymer or copolymer comprising conjugated diene monomer and vinyl aromatic hydrocarbon or hydrogenated product thereof Master batch obtained by kneading 5 to 300 parts by weight of an inorganic filler with 100 parts by weight of at least one modified polymer selected from modified polymers having at least one containing atomic group bonded: 1 to 150 parts by weight The manufacturing method of the rubber composition for footwear including the process of kneading | mixing.
13. 13. The rubber composition for footwear according to item 12 above, wherein the component (2) is a masterbatch obtained by adding a total amount of 5 to 300 parts by weight of an inorganic filler to a kneader and then kneading by adding a modified polymer. Manufacturing method.
14 13. The method for producing a rubber composition for footwear according to 12 above, wherein the component (2) is a masterbatch obtained by dividing 5 to 300 parts by weight of the inorganic filler twice or more, charging the mixture into a kneader and sequentially kneading.
15. 2. The method for producing a masterbatch according to item 1, wherein the total amount of 5 to 300 parts by weight of the inorganic filler is put into a kneader and kneaded, and then the modified polymer is added and kneaded.
16. 20 to 80% by weight of the inorganic filler is previously charged in a kneader and kneaded, then the modified polymer is added and kneaded, and the remaining amount of the inorganic filler is added and kneaded. Production method.
The rubber composition for footwear of the present invention manufactured by using a master batch of a modified polymer to which a specific functional group-containing atomic group is bonded and an inorganic filler is used when tear strength, abrasion resistance, and water-based adhesion are used. It is a rubber composition that is excellent in adhesiveness and can improve the working environment of a shoe factory.

上記式（１）〜（１４）において、 Ｎは窒素原子、Ｓｉは珪素原子、Ｏは酸素原子、Ｃは炭素原子、Ｈは水素原子を表し、Ｒ^１，Ｒ^２は各々独立に水素原子又は炭素数１〜２４の炭化水素基を表し、且つ、該炭化水素基は、所望により、各々独立に、水酸基、エポキシ基、アミノ基、炭素数１〜２４の炭化水素基を有するイミノ基、シラノール基及び炭素数１〜２４のアルコキシシラン基からなる群より選ばれる少なくとも１種の官能基を有してもよく、各Ｒ^３は各々独立に炭素数１〜４８の２価の炭化水素基を表し、且つ、所望により、各々独立に、水酸基、エポキシ基、アミノ基、炭素数１〜２４の炭化水素基を有するイミノ基、シラノール基及び炭素数１〜２４のアルコキシシラン基からなる群より選ばれる少なくとも１種の官能基を有してもよく、各Ｒ^４は各々独立に水素原子又は炭素数１〜２４の炭化水素基を表す。
本発明において、変性重合体に結合している上記の官能基含有原子団を形成するために用いることができる変性剤としては、上記の官能基を有する公知の化合物及び／又は形成し得る公知の化合物を用いることができる。例えば特公平４−３９４９５号公報（米国特許第５，１１５，０３５号に対応）に記載された末端変性処理剤を用いることができる、具体的には、下記のものが挙げられる。
上記式（１）〜（６）の官能基を有する変性剤の例としては、テトラグリシジルメタキシレンジアミン、テトラグリシジル−１，３−ビスアミノメチルシクロヘキサン、テトラグリシジル−ｐ−フェニレンジアミン、テトラグリシジルジアミノジフェニルメタン、ジグリシジルアニリン、ジグリシジルオルソトルイジン、Ｎ−（１，３−ジブチルブチリデン）−３−（トリエトキシシリル）−１−プロパンアミン、４−ジ（β−トリメトキシシリルエチル）アミノスチレン、４−ジ（β−トリエトキシシリルエチル）アミノスチレン、４−ジ（γ−トリメトキシシリルプロピル）アミノスチレン、４−ジ（γ−トリエトキシシリルプロピル）アミノスチレンが挙げられる。
上記式（７）の官能基を有する変性剤の例としては、ε−カプロラクトン、δ−バレロラクトン、ブチロラクトン、γ−カプロラクトン、γ−バレロラクトンなどの環状ラクトンが挙げられる。
上記式（８）の官能基を有する変性剤の例としては、４−メトキシベンゾフェノン、４−エトキシベンゾフェノン、４，４’−ビス（メトキシ）ベンゾフェノン、４，４’−ビス（エトキシ）ベンゾフェノン、γ−グリシドキシエチルトリメトキシシラン、γ−グリシドキシプロピルトリメトキシシランが挙げられる。
上記式（９）及び（１０）の官能基を有する変性剤の例としては、γ−グリシドキシブチルトリメトキシシラン、γ−グリシドキシプロピルトリエトキシシラン、γ−グリシドキシプロピルトリプロポキシシラン、γ−グリシドキシプロピルトリブトキシシランが挙げられる。
上記式（１１）の官能基を有する変性剤の例としては、１，３−ジメチル−２−イミダゾリジノン、１，３−ジエチル−２−イミダゾリジノンが挙げられる。
上記式（１２）の官能基を有する変性剤の例としては、Ｎ，Ｎ’−ジメチルプロピレンウレア、Ｎ−メチルピロリドンなどが挙げられる。
また、上記式（１３）及び（１４）の官能基を有する原子団を有する変性重合体は、それぞれ、上記式（１１）及び（１２）の官能基含有原子団を有する非水添変性重合体を水添することによって得られる。
本発明の成分（２）で使用する変性重合体の水添物は、重合体を変性してから水添することによっても製造できるし、重合体を水添した後、変性することによっても製造できる。たとえば、重合体を変性してから水添する場合、有機リチウム化合物を重合触媒として用いて得られた重合体のリビング末端に、上記の変性剤と反応させることにより変性重合体を得、得られた変性重合体を水添することにより、水添物の変性重合体が得られる。
また、本発明の成分（２）で使用する変性重合体を得る他の方法として、重合体に有機リチウム化合物等の有機アルカリ金属化合物を反応（メタレーション反応）させ、有機アルカリ金属化合物が付加した重合体を得、これに上記の変性剤を付加反応させる方法が挙げられる。この場合は、重合体の水添物を得た後にメタレーション反応させ、上記の変性剤を反応させて水添物の変性重合体を得ることもできる。
なお、変性剤の種類により、変性剤を反応させた段階で水酸基やアミノ基等は有機金属塩となっていることもあるが、その場合には水やアルコールなどの活性水素を有する化合物で処理することにより、水酸基やアミノ基等にすることができる。
本発明において、変性反応をおこなう際の反応圧力は特に限定されるものではないが、通常０．２〜２ＭＰａであり、好ましくは０．３〜１ＭＰａである。反応温度は、０〜１５０℃の範囲が好ましく、より好ましくは２０〜１２０℃、更に好ましくは５０〜１００℃の範囲である。変性反応に要する時間は、一般に調整する際の反応温度に左右されるが１秒から１０時間の範囲であり、好ましくは１秒〜３時間の範囲である。
本発明においては、重合体に変性剤を反応させた後に変性されていない重合体が変性重合体に混在していてもよい。変性重合体に混在する未変性の重合体の量は、変性重合体の重量に対して好ましくは７０重量％以下、より好ましくは６０重量％以下、更に好ましくは５０重量％以下である。
本発明において、変性重合体の水添物は、上記で得られた変性重合体を水素添加することにより得られる。水添触媒としては、特に制限されず、従来から公知である（１）Ｎｉ、Ｐｔ、Ｐｄ、Ｒｕ等の金属をカーボン、シリカ、アルミナ、ケイソウ土等に担持させた担持型不均一系水添触媒、（２）Ｎｉ、Ｃｏ、Ｆｅ、Ｃｒ等の有機酸塩又はアセチルアセトン塩などの遷移金属塩と有機アルミニウム等の還元剤とを用いる、いわゆるチーグラー型水添触媒、（３）Ｔｉ、Ｒｕ、Ｒｈ、Ｚｒ等の有機金属化合物等のいわゆる有機金属錯体等の均一系水添触媒が用いられる。
具体的な水添触媒としては、特公昭４２−８７０４号公報、特公昭４３−６６３６号公報、特公昭６３−４８４１号公報、特公平１−３７９７０号公報、特公平１−５３８５１号公報、特公平２−９０４１号公報に記載された水添触媒を使用することができる。好ましい水添触媒としてはチタノセン化合物および／または還元性有機金属化合物との混合物があげられる。チタノセン化合物としては、特開平８−１０９２１９号公報に記載された化合物が使用できるが、具体例としては、ビスシクロペンタジエニルチタンジクロライド、モノペンタメチルシクロペンタジエニルチタントリクロライド等の（置換）シクロペンタジエニル骨格、インデニル骨格あるいはフルオレニル骨格を有する配位子を少なくとも１つ以上もつ化合物があげられる。また、還元性有機金属化合物としては、有機リチウム等の有機アルカリ金属化合物、有機マグネシウム化合物、有機アルミニウム化合物、有機ホウ素化合物あるいは有機亜鉛化合物等があげられる。
水添反応は好ましくは０〜２００℃、より好ましくは３０〜１５０℃の温度範囲で実施される。水添反応に使用される水素の圧力は、好ましくは０．１〜１５ＭＰａ、より好ましくは０．２〜１０ＭＰａ、更に好ましくは０．３〜５ＭＰａが推奨される。また、水添反応時間は好ましくは３分〜１０時間、より好ましくは１０分〜５時間である。水添反応は、バッチプロセス、連続プロセス、或いはそれらの組み合わせのいずれでも用いることができる。
本発明に使用される変性重合体の水添物において、共役ジエン系単量体単位に基づく不飽和二重結合のトータル水素添加率は目的に合わせて任意に選択でき、特に限定されない。熱安定性及び耐候性の良好な変性重合体の水添物を得る場合、変性重合体中の共役ジエン系単量体単位に基づく不飽和二重結合の７０％以上、好ましくは８０％以上、更に好ましくは９０％以上が水添されていていることが推奨される。また、一部のみが水添されていても良い。一部のみを水添する場合には、水添率が１０％以上７０％未満、或いは１５％以上６５％未満、所望によっては２０％以上６０％未満にすることが好ましい。更に、水素添加前の共役ジエン系単量体に基づくビニル結合の水素添加率は、好ましくは８５％以上、より好ましくは９０％以上、更に好ましくは９５％以上であることが、熱安定性に優れたゴム組成物を得る上で推奨される。ここで、ビニル結合の水素添加率とは、変性重合体中に組み込まれている水素添加前の共役ジエン系単量体に基づくビニル結合のうち水素添加されたビニル結合の割合をいう。なお、変性ランダム共重合体や変性ブロック共重合体中のビニル芳香族炭化水素に基づく芳香族二重結合の水添率については特に制限はないが、好ましくは５０％以下、より好ましくは３０％以下、更に好ましくは２０％以下が推奨される。水添率は、核磁気共鳴装置（ＮＭＲ）により知ることができる。
次に、本発明において、マスターバッチの調整で使用する変性重合体に結合している官能基と反応性を有する化合物（４）を反応させた二次変性重合体を用いることもできる。二次変性重合体とは、化合物（４）である二次変性剤を本発明の変性重合体と反応させることによって得られるものであって、該二次変性剤は該変性重合体の官能基と反応性を有する官能基を有する化合物である。
化合物（４）である二次変性剤の官能基の好ましい例として、カルボキシル基、酸無水物基、イソシアネート基、エポキシ基、シラノール基及びアルコキシシラン基から選ばれる少なくとも１種が挙げられる。上記の官能基を少なくとも２個以上有している二次変性剤が特に好ましい。但し、官能基が酸無水物基である場合は、酸無水物基を１個のみ有する二次変性剤も特に好ましい。変性重合体に二次変性剤を反応させる場合の二次変性剤の量は、変性重合体に結合されている官能基１当量あたり、通常０．３〜１０モル、好ましくは０．４〜５モル、更に好ましくは０．５〜４モルの範囲である。
変性重合体に二次変性剤を反応させる方法は、特に制限されるものではないが公知の方法が利用できる。例えば、後述する溶融混練方法や各成分を溶媒等に溶解又は分散混合して反応させる方法などが挙げられる。各成分を溶媒等に溶解又は分散混合して反応させる方法において、溶媒としては各成分を溶解又は分散するものであれば特に限定はなく、脂肪族炭化水素、脂環式炭化水素、芳香族炭化水素などの炭化水素溶媒の他、含ハロゲン系溶媒、エステル系溶媒、エーテル系溶媒などが使用できる。かかる方法において変性重合体に二次変性剤を反応させる温度は、通常−１０〜１５０℃、好ましくは３０〜１２０℃である。反応に要する時間は一般に調整する際の反応温度に左右されるが、通常３時間以内であり、好ましくは数秒〜１時間である。特に好ましい方法は、製造した変性重合体の溶液中に二次変性剤を添加して反応させることにより二次変性重合体を得る方法である。
次に二次変性剤の具体例について説明する。カルボキシル基を有する二次変性剤の例としては、マレイン酸、シュウ酸、コハク酸、アジピン酸、アゼライン酸、セバシン酸、ドデカンジカルボン酸、カルバリル酸、シクロヘキサンジカルボン酸、シクロペンタンジカルボン酸等の脂肪族カルボン酸；テレフタル酸、イソフタル酸、オルトフタル酸、ナフタレンジカルボン酸、ビフェニルジカルボン酸、トリメシン酸、トリメリット酸、ピロメリット酸等の芳香族カルボン酸が挙げられる。
酸無水物基を有する二次変性剤の例としては、無水マレイン酸、無水イタコン酸、無水ピロメリット酸、シス−４−シクロヘキサン−１，２−ジカルボン酸無水物、１，２，４，５−ベンゼンテトラカルボン酸二無水物、５−（２，５−ジオキシテトラヒドロ−３−フラニル）−３−メチル−３−シクロヘキセン−１，２−ジカルボン酸無水物が挙げられる。
イソシアナート基を有する二次変性剤の例としては、トルイレンジイソシアナート、ジフェニルメタンジイソシアナート、多官能芳香族イソシアナート（即ちイソシアナート基が３個以上芳香族環に結合した化合物）等が挙げられる。
エポキシ基を有する二次変性剤の例としてはテトラグリジジル−１，３−ビスアミノメチルシクロヘキサン、テトラグリシジル−ｍ−キシレンジアミン、ジグリシジルアニリン、エチレングリコールジグリシジル、プロピレングリコールジグリシジル、テレフタル酸ジグリシジルエステルアクリレート等が挙げられる。
シラノール基を有する二次変性剤の例としては、変性重合体を得るために使用される変性剤として記載した上記のアルコキシシラン化合物の加水分解物等が挙げられる。
アルコキシシラン基を有する二次変性剤の例としては、ビス−（３−トリエトキシシリルプロピル）−テトラスルファン、ビス−（３−トリエトキシシリルプロピル）−ジスルファン、エトキシシロキサンオリゴマーが挙げられる。
また、反応性を有する官能性オリゴマーも二次変性剤として使用することもできる。官能性オリゴマーの官能基は、変性重合体に結合している官能基と反応性を有する官能基であれば、特に限定はない。官能性オリゴマーの好ましい例として、水酸基、アミノ基、カルボキシル基、酸無水物基、イソシアネート基、エポキシ基、シラノール基、アルコキシシラン基からなる群より選ばれる少なくとも一種の官能基を有する官能性オリゴマーが挙げられる。これらの官能性オリゴマーの数平均分子量は、通常３００以上で３，００００未満、好ましくは５００以上で１５，０００未満、更に好ましくは１，０００以上で２０，０００未満である。官能性オリゴマーの具体例としては、上記官能基を少なくとも１個有するブタジエンオリゴマーまたはその水添物、上記官能基を少なくとも１個有するイソプレンオリゴマーまたはその水添物、上記官能基を少なくとも１個有するエチレンオリゴマー、上記官能基を少なくとも１個有するプロピレンオリゴマー、エチレンオキサイドオリゴマー、プロピレンオキサイドオリゴマー、エチレンオキサイド−プロピレンオキサイド共重合オリゴマー、スチレン−無水マレイン酸共重合体オリゴマー、エチレン−酢酸ビニル共重合オリゴマーのケン化物等が挙げられる。
本発明において特に好ましい二次変性剤の例として、カルボキシル基を２個以上有するカルボン酸又はその酸無水物、或いは酸無水物基、イソシアネート基、エポキシ基、シラノール基、アルコキシシラン基を２個以上有す変性剤であり、具体例として、無水マレイン酸、無水ピロメリット酸、１，２，４，５−ベンゼンテトラカルボン酸二無水物、トルイレンジイソシアナート、テトラグリジジル−１，３−ビスアミノメチルシクロヘキサン、ビス−（３−トリエトキシシリルプロピル）−テトラスルファン、スチレン−無水マレイン酸共重合体オリゴマー等が挙げられる。
また、成分（２）のマスターバッチを調整する際に、変性重合体と無機充填剤の他に上記の化合物（４）である二次変性剤を添加することができる。二次変性剤の量は、当該変性重合体１００重量部に対して０．０１〜２０重量部、好ましくは０．０２〜１０重量部、更に好ましくは０．０５〜７重量部の範囲である。
本発明の成分（２）で使用する変性重合体又は二次変性重合体の重量平均分子量は、ゴム組成物の機械的強度及び耐摩耗性の点から３万以上、加工性の点から１２０万以下であることが好ましく、より好ましくは５万〜１００万、更に好ましくは１０〜８０万の範囲である。変性重合体の重量平均分子量は、ゲルパーミュエーションクロマトグラフィー（ＧＰＣ）による測定を行い、クロマトグラムのピークの分子量を、市販の標準ポリスチレンの測定から求めた検量線（標準ポリスチレンのピーク分子量を使用して作成）を使用して求めることができる。
上記のようにして得られた変性重合体の溶液は、必要に応じて触媒残渣を除去し、変性重合体を溶液から分離することができる。溶媒の分離の方法としては、例えば重合後又は水添後の溶液にアセトンまたはアルコール等の重合体に対する貧溶媒となる極性溶媒を加えて重合体を沈澱させて回収する方法、変性重合体の溶液を撹拌下熱湯中に投入し、スチームストリッピングにより溶媒を除去して回収する方法、または直接重合体溶液を加熱して溶媒を留去する方法等を挙げることができる。尚、本発明で使用する変性重合体又はその水添物には、各種フェノール系安定剤、リン系安定剤、イオウ系安定剤、アミン系安定剤等の安定剤を添加することができる。
本発明において、成分（２）のマスターバッチの原料として用いられる無機充填剤又は成分（３）の無機充填剤は、公知の補強性充填剤、例えば、天然シリカ、湿式法又は乾式法で製造した合成シリカ、カオリン、マイカ、タルク、クレイ、モンモリロナイト、ゼオライト、天然ケイ酸塩、ケイ酸カルシウム、ケイ酸アルミニウム等の合成ケイ酸塩、水酸化マグネシウム、水酸化アルミニウム、水酸化カルシウム、水酸化バリウム等の金属水酸化物、アルミナ、酸化チタン、酸化マグネシウム、酸化亜鉛等の金属酸化物、軽質炭酸カルシウム、重質炭酸カルシウム、種々の表面処理炭酸カルシウム、炭酸マグネシウムなどの金属炭酸化物、硫酸バリウム、硫酸マグネシウム、硫酸カルシウム等の金属硫酸化物、アルミニウム、ブロンズ等の金属粉、カーボンブラック等の少なくとも１種の成分である。好ましい無機充填剤として、シリカ系無機充填剤、金属酸化物、金属水酸化物、カーボンが挙げられる。上記の無機充填剤を単独で使用しても良いし、２種類以上を組み合わせて使用することもできる。
シリカ系無機充填剤とは化学式ＳｉＯ２を構成単位の主成分とする固体粒子のことをいい、例えばシリカ、クレイ、タルク、マイカ、珪藻土、ウォラストナイト、モンモリロナイト、ゼオライト、ガラス繊維等の無機繊維状物質などを用いることができる。また表面を疎水化したシリカ系無機充填剤や、シリカ系無機充填剤とシリカ系以外の無機充填剤の混合物も使用できる。本発明においてはシリカが好ましい。シリカとしては乾式法ホワイトカーボン、湿式法ホワイトカーボン、合成ケイ酸塩系ホワイトカーボン、コロイダルシリカと呼ばれているもの等が使用できる。これらは粒径が０．０１〜１５０μｍのものが好ましい。また本発明の組成物において、シリカが組成物中に分散し、シリカの添加効果を十分に発揮するためには、平均分散粒子径０．０５〜１μｍが好ましく、より好ましくは０．０５〜０．５μｍである。
次に金属酸化物とは、化学式ＭｘＯｙ（Ｍは金属原子、ｘ、ｙは各々１〜６の整数）を構成単位の主成分とする固体粒子のことをいい、例えばアルミナ、酸化チタン、酸化マグネシウム、酸化亜鉛等を用いることができる。また金属酸化物と金属酸化物以外の無機充填剤の混合物も使用できる。また本発明で用いる金属水酸化物は、水酸化アルミニウム、水酸化マグネシウム、水酸化ジルコニウム、水和珪酸アルミニウム、水和珪酸マグネシウム、塩基性炭酸マグネシウム、ハイドロタルサイト、水酸化カルシウム、水酸化バリウム、酸化錫の水和物、硼砂等の無機金属化合物の水和物等、水和系無機充填材であり、中でも水酸化マグネシウム、水酸化アルミニウムが好ましい。
カーボンブラックとしては、ＦＴ、ＳＲＦ、ＦＥＦ、ＨＡＦ、ＩＳＡＦ、ＳＡＦ等の各クラスのカーボンブラックが使用でき、窒素吸着比表面積が５０ｍｇ／ｇ以上、ＤＢＰ吸油量が８０ｍｌ／１００ｇのカーボンブラックが好ましい。
本発明において、成分（２）のマスターバッチの調整に使用する無機充填剤の量は、変性重合体１００重量部に対して５〜３００重量部、好ましくは５〜２００重量部、更に好ましくは１０〜１５０重量部の範囲である。無機充填剤の量が３００重量部を超えると、無機充填剤の分散性が劣りマスターバッチの加工性が悪くなる。また、５重量部未満では本発明の効果である接着性が劣る。
また、本発明において成分（３）の無機充填剤の配合量は、成分（１）のゴム状重合体１００重量部に対し０．１〜１５０量部、好ましくは５〜１００重量部、更に好ましくは５〜５０量部である。無機充填剤の配合量が１５０重量部を超えると無機充填剤の分散性が劣り、加工性及び機械強度が劣るため好ましくない。
本発明の履物用ゴム組成物の製造にシリカ系無機充填剤を用いた場合、シランカップリング剤を使用することができる。シランカップリング剤は、ゴム状重合体と無機充填剤の相互作用を緊密にするためのものであり、ゴム状重合体と無機充填剤とにそれぞれ親和性あるいは結合性の基を有しているものである。具体的には、ビス−［３−（トリエトキシシリル）−プロピル］−テトラスルフィド、ビス−［３−（トリエトキシシリル）−プロピル］−ジスルフィド、ビス−［２−（トリエトキシシリル）−エチル］−テトラスルフィド、３−メルカプトプロピル−トリメトキシシラン、ビニルトリメトキシシラン、ビニルトリエトキシシラン等があげられる。
好ましいシランカップリング剤は、アルコキシシランを有すると同時に硫黄が２個以上連結したポリスルフィド結合を有するものであり、その例としてはビス−［３−（トリエトキシシリル）−プロピル］−テトラスルフィド、ビス−［３−（トリエトキシシリル）−プロピル］−ジスルフィドなどがあげられる。シランカップリング剤の配合量は、補強性充填剤に対して、０．１〜３０重量％、好ましくは０．５〜２０重量％、更に好ましくは１〜１５重量％である。
本発明の成分（２）のマスターバッチにおいて、無機充填剤と親和性が高い官能基が結合している変性重合体を使用することで、無機充填剤の表面に存在する官能基と変性重合体との間で、化学的な結合や水素結合等の物理的な相互作用が効果的に発現され、引き裂き強度、耐摩耗性、接着性に優れた履物用ゴム組成物を得ることができる。
本発明の成分（２）であるマスターバッチの製造方法は、特に制限されるものではなく公知の方法が利用できる。例えば、バンバリ−ミキサ−、単軸スクリュー押出機、２軸スクリュ−押出機、コニ−ダ、多軸スクリュー押出機、ロール等の一般的な混合機を用いた混練方法、各成分を溶解、混合した後、溶剤を加熱除去する方法等が用いられる。好ましい方法はバンバリーミキサー、コニーダーで各成分を混練する方法である。
マスターバッチを製造するにあたり、変性重合体及び無機充填剤の添加順序には制限が無く、全成分を一度に混練機に入れて混合する方法、各成分を２回以上分割して混合機に入れて順次混練する方法、変性重合体を混練機に入れて混練し、その後無機充填剤を加えて混練する方法、無機充填剤を混練機に入れて混練し、その後変性重合体を加えて混練する方法、無機充填剤を連続的に混練機に入れて混練する方法等が採用できる。
マスターバッチを製造する際の混練温度は、変性重合体の劣化や変性重合体と無機充填剤の相互作用を促進し無機充填剤の分散性の良いマスターバッチを得る為に、一般に８０〜３００℃が好ましく、より好ましくは１３０〜２５０℃、更に好ましくは１５０〜２２０℃の範囲である。また、混練時間は、無機充填剤の分散性、マスターバッチの生産性、変性重合体の劣化等の点から、一般に０．２〜６０分が好ましく、より好ましくは０．５〜３０分、更に好ましくは１〜２０分の範囲である。
特に好ましい方法は、無機充填剤の全量を予め混練機に入れて混練し、次いで変性重合体を加えて混練して製造する方法、無機充填剤を２回以上分割して混練機に投入して変性重合体と無機充填剤を混練して製造する方法である。
無機充填剤を２回以上分割して混練機に入れる方法としては、マスターバッチを製造する工程の煩雑さを考慮すると、無機充填剤を２〜１０回に分割して添加することが好ましく、特に２〜５回に分割して添加する方法が好ましい。具体的には、無機充填剤の２０〜８０重量％、好ましくは３０〜８０重量％、更に好ましくは４０〜８０重量％を予め混練機に投入し、混練時間を１秒〜６０分、好ましくは０．５分〜３０分、更に好ましくは１分〜２０分の範囲で混練した後、変性重合体を入れて混練時間を１秒〜６０分、好ましくは２０秒〜３０分、更に好ましくは１分〜２０分の範囲で混練し、次いで残りの無機充填剤を加えて、混練時間を１秒〜６０分、好ましくは０．５分〜３０分、更に好ましくは１分〜２０分の範囲で混練して製造する方法である。もう一つの好ましい方法として、無機充填剤の全量を予め混練機に投入し、混練時間を１秒〜６０分、好ましくは０．５分〜３０分、更に好ましくは１分〜２０分の範囲で混練した後、変性重合体を入れて混練時間を１秒〜６０分、好ましくは０．５分〜３０分、更に好ましくは１分〜２０分の範囲で混練して製造する方法がある。
特に好ましい形態のマスターバッチを調整する為に最も重要なことは、無機充填剤５〜３００重量部の少なくとも２０重量％以上を予め混練機に入れ、温度を５０〜３００℃、好ましくは７０〜２５０℃、更に好ましくは１００〜２００℃の範囲で混練し、その後残りの成分を入れて混練することでマスターバッチを調整することである。
本発明の履物用ゴム組成物は、ゴム状重合体（成分１）及びマスターバッチ（成分２）、又はゴム状重合体（成分１）及びマスターバッチ（成分２）及び無機充填剤（成分３）を含むゴム組成物である。マスターバッチの量は、ゴム状重合体（成分１）１００重量部に対して１〜１５０重量部、好ましくは５〜１００重量部、更に好ましくは１０〜７０重量部の範囲である。
本発明の履物用ゴム組成物の製造方法は、特に制限されるものではなく、公知の方法が利用できる。例えば、バンバリ−ミキサ−、単軸スクリュー押出機、２軸スクリュ−押出機、コニ−ダ、多軸スクリュー押出機等の一般的な混和機を用いた混練方法等が用いられる。
また本発明の履物用ゴム組成物を製造するにあたり、各成分の添加順序には制限が無く、成分（１）、成分（２）、成分（３）を一度に混練機に入れて混練する方法、任意の成分を予備混合した後、残りの成分を添加する等の方法が採用できる。混練温度は、ゴム状重合体や変性重合体の熱劣化の点から、５０〜３００℃が好ましく、より好ましくは７０〜２５０℃、更に好ましくは１００〜２００℃である。また、混練時間は、無機充填剤の分散性やゴム組成物の生産性、変性重合体やゴム状重合体の劣化等の点から、一般に０．２〜６０分が好ましく、より好ましくは０．５〜３０分、更に好ましくは１〜２０分の範囲である。
本発明の履物用ゴム組成物は、変性重合体と無機充填剤を上記に示した特定の製造方法で混練して得られる無機フィラーの分散性に優れるマスターバッチを用いることに特徴がある。従来から行われているゴム状重合体又は変性重合体と無機充填剤とを混練して得られる履物用ゴム組成物と比較して、無機充填剤の分散性が向上したことによって耐摩耗性と接着性に優れる履物用ゴム組成物を得ることができる。ゴム組成物中の無機充填剤の分散性は、透過型電子顕微鏡や走査型プローブ顕微鏡装置等を用いることによって確認することができる。
本発明において、その他必要に応じて任意の添加剤を配合することができる。添加剤の種類は、ゴム状重合体の配合に一般的に用いられるものであれば特に制限はない。亜鉛華、ステアリン酸、加硫助剤、老化防止剤、加工助剤、ベヘニン酸、ステアリン酸亜鉛、ステアリン酸カルシウム、ステアリン酸マグネシウム、エチレンビスステアロアミド等の滑剤、離型剤、パラフィン系プロセスオイル、ナフテン系プロセスオイル、芳香族系プロセスオイル、パラフィン、有機ポリシロキサン、ミネラルオイル等の軟化剤・可塑剤、ヒンダードフェノール系酸化防止剤、リン系熱安定剤等の酸化防止剤、ヒンダードアミン系光安定剤、ベンゾトリアゾール系紫外線吸収剤、難燃剤、帯電防止剤、有機繊維、ガラス繊維、炭素繊維、金属ウィスカー等の補強剤、着色剤、その他添加剤或いはこれらの混合物、「ゴム・プラスチック配合薬品」（ラバーダイジェスト社編）などに記載されたものが挙げられる。The present invention will be specifically described below.
The kind of the rubbery polymer which is the component (1) constituting the rubber composition for footwear of the present invention is not particularly limited, but is a conjugated diene polymer or a hydrogenated product thereof, a conjugated diene monomer and a vinyl aromatic. Random copolymers consisting of hydrocarbons or hydrogenated products thereof, block copolymers consisting of conjugated diene monomers and vinyl aromatic hydrocarbons or hydrogenated products thereof, non-diene polymers, natural rubber, etc. . Specifically, butadiene rubber or hydrogenated product thereof, isoprene rubber or hydrogenated product thereof, styrene-butadiene rubber or hydrogenated product thereof, styrene-butadiene block copolymer or hydrogenated product thereof, styrene-isoprene block copolymerized Styrene elastomer such as coalescence or hydrogenated product thereof, acrylonitrile-butadiene rubber or hydrogenated product thereof, and non-diene polymers include ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-butene- Olefin-based elastomers such as diene rubber, ethylene-butene rubber, ethylene-hexene rubber, ethylene-octene rubber, butyl rubber, brominated butyl rubber, acrylic rubber, fluorine rubber, silicone rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, α, β -Unsaturated nitrile-acrylic acid ester-conjugated diene copolymer rubber, urethane rubber and the like. These rubber-like polymers may be modified rubbers provided with functional groups. The rubber-like polymer can be used alone or as a mixture in which two or more kinds of rubber-like polymers are mixed.
Component (2) constituting the rubber composition for footwear of the present invention contains a conjugated diene polymer or a copolymer comprising a conjugated diene monomer and a vinyl aromatic hydrocarbon, or a hydrogenated product thereof. A rubber composition obtained by previously kneading at least one modified polymer selected from modified polymers having at least one atomic group bonded thereto and an inorganic filler into a master batch.
The modified conjugated diene polymer or modified copolymer comprising a conjugated diene monomer and a vinyl aromatic hydrocarbon used in component (2) of the present invention is at least one conjugated diene monomer and at least 1 It can be produced by subjecting various types of vinyl aromatic aromatic hydrocarbons to solution polymerization in the presence of an organolithium catalyst. As the method for producing the modified polymer of the present invention, any production method can be adopted as long as the polymer having the structure of the present invention can be obtained.
The conjugated diene monomer in the present invention is a diolefin having a pair of conjugated double bonds, such as 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl- 1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene and the like can be mentioned, and particularly common ones include 1,3-butadiene and isoprene. These may be used alone or in combination of two or more in the production of the polymer.
Examples of the vinyl aromatic hydrocarbon include styrene, o-methyl styrene, p-methyl styrene, p-tert-butyl styrene, 1,3-dimethyl styrene, α-methyl styrene, vinyl naphthalene, and vinyl anthracene. However, styrene and α-methylstyrene are particularly common. These may be used alone or in combination of two or more in the production of the polymer.
Solvents used for the production of modified polymers include aliphatic hydrocarbons such as butane, pentane, hexane, isopentane, heptane, octane, isooctane, and alicyclic rings such as cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, and ethylcyclohexane. Or hydrocarbon solvents such as aromatic hydrocarbons such as benzene, toluene, ethylbenzene, and xylene. These may be used alone or in combination of two or more.
The organolithium compound used for the production of the modified polymer is a compound in which one or more lithium atoms are bonded in the molecule. For example, ethyllithium, n-propyllithium, isopropyllithium, n-butyllithium, sec- Examples thereof include butyl lithium, tert-butyl lithium, hexamethylene dilithium, butadienyl dilithium, and isoprenyl dilithium. Further, organic alkali metals such as amidolithium disclosed in US Pat. No. 5,708,092, British Patent 2,241,239, US Pat. No. 5,527,753, etc. Compounds can also be used. These may be used alone or in combination of two or more. In addition, the organolithium compound may be divided and added one or more times during the polymerization in the production of the polymer.
In the present invention, adjustment of the polymerization rate during production of the polymer, change of the microstructure of the conjugated diene moiety in the polymer, adjustment of the reactivity ratio between the conjugated diene monomer and the vinyl aromatic hydrocarbon A polar compound or a randomizing agent can be used for the purpose. Examples of polar compounds and randomizing agents include ethers, amines, thioethers, phosphoramides, potassium or sodium salts of alkylbenzene sulfonic acids, potassium or sodium alkoxides, and the like.
Examples of ethers include dimethyl ether, diethyl ether, diphenyl ether, tetrahydrofuran, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether and the like. Examples of amines include tertiary amine, trimethylamine, triethylamine, tetramethylethylenediamine, and other cyclic tertiary amines. Examples of phosphine and phosphoramide include triphenylphosphine and hexamethylphosphoramide.
The polymerization temperature at the time of producing the polymer is preferably -10 to 150 ° C, more preferably 30 to 120 ° C. The time required for the polymerization varies depending on the conditions, but is preferably within 48 hours, particularly preferably 0.5 to 10 hours. The polymerization atmosphere is preferably an inert gas atmosphere such as nitrogen gas. The pressure of the polymerization system may be a pressure range sufficient to maintain the monomer and solvent in the liquid phase within the above polymerization temperature range, and is not particularly limited, but is usually 0.2 to 2 MPa. , Preferably 0.3 to 1.5 MPa. The reaction temperature is preferably in the range of 0 to 150 ° C, more preferably in the range of 20 to 120 ° C, and still more preferably in the range of 50 to 100 ° C. Furthermore, it is preferable that impurities such as water, oxygen, carbon dioxide gas, etc. that inactivate the catalyst and living polymer are not mixed in the polymerization system.
The modified polymer of the conjugated diene polymer or its hydrogenated product used in the component (2) of the present invention is a conjugated diene monomer homopolymer or a conjugated diene having a vinyl aromatic hydrocarbon content of less than 5 wt%. It is a modified polymer of a polymer. The structure of the conjugated diene polymer or its hydrogenated product may be linear or branched, or any mixture thereof. Further, the copolymer composed of a conjugated diene monomer and a vinyl aromatic hydrocarbon or a hydrogenated product thereof may be a random copolymer or a block copolymer. Further, the structure of the modified copolymer or its hydrogenated product may be linear, branched, or any mixture thereof.
The vinyl aromatic hydrocarbon content of the random copolymer consisting of the conjugated diene monomer and vinyl aromatic hydrocarbon used in component (2) of the present invention or its hydrogenated product is usually in the range of 5 to 95 wt%. Yes, preferably 10 to 90 wt%, more preferably 15 to 85 wt%. Further, even if two or more random copolymer blocks having different vinyl aromatic hydrocarbon contents are present in the polymer chain of the random copolymer or its hydrogenated product, the conjugated diene polymer block or its water is further present. One or more additives may be present.
A modified polymer of a conjugated diene polymer or a modified polymer of a random copolymer can be obtained by addition reaction of a modifying agent described later to the living terminal of the conjugated diene polymer or random copolymer.
The vinyl aromatic hydrocarbon content of the block copolymer consisting of a conjugated diene monomer and a vinyl aromatic hydrocarbon or a hydrogenated product thereof used in the component (2) of the present invention is usually in the range of 5 to 95 wt%. More preferably, it is 10-90 wt%, More preferably, it is the range of 15-85 wt%. When the vinyl aromatic hydrocarbon content of the block copolymer or its hydrogenated product is 60 wt% or more, preferably 65 wt% or more, it has resin-like characteristics, and when it is less than 60 wt%, preferably 55 wt% or less. Has elastic properties.
Examples of the method for producing the block copolymer include Japanese Patent Publication No. 36-19286, Japanese Patent Publication No. 43-17879, Japanese Patent Publication No. 46-32415, Japanese Patent Publication No. 49-36957, Japanese Patent Publication No. 48-2423. And the methods described in JP-B-48-4106, JP-B-56-28925, JP-B-51-49567, JP-A-59-166518, JP-A-60-186777, and the like. It is done.
A modified polymer of the block copolymer used in the present invention is obtained by addition reaction of a modifying agent described later to the living terminal of the block copolymer obtained by these methods. For example, a structure represented by the following general formula Have
(A-B) n-X, A- (B-A) n-X,
B- (AB) n-X, X- (AB) n,
X- (A-B) n-X, X-A- (BA) n-X,
X-B- (AB) n-X, [(B-A) n] m-X,
[(AB) n] mX, [(BA) nB] mX,
[(AB) n-A] m-X
(In the above formula, A is a polymer block mainly composed of vinyl aromatic hydrocarbon, and B is a polymer block mainly composed of conjugated diene monomer. The boundary between A block and B block is not necessarily limited. It is not necessary to distinguish clearly, and n is an integer of 1 or more, preferably an integer of 1 to 5. m is an integer of 2 or more, preferably an integer of 2 to 11. X is described later. It shows the residue of the modifying agent to which an atomic group having a functional group is bonded.When X is added by a metallation reaction described later, it is bonded to the side chain of the A block and / or B block)
In the structure represented by the above general formula, the polymer block A mainly composed of vinyl aromatic hydrocarbon preferably contains 50 wt% or more, more preferably 70 wt% or more of vinyl aromatic hydrocarbon. It is a copolymer block of hydrogen and a conjugated diene monomer or a homopolymer block of vinyl aromatic hydrocarbon, and the vinyl aromatic hydrocarbon is distributed uniformly or in a tapered shape. Also good. The polymer block B mainly composed of a conjugated diene monomer preferably contains a conjugated diene monomer in an amount exceeding 50 wt%, more preferably 60 wt% or more, and a vinyl aromatic carbonization. It is a copolymer block with hydrogen or a homopolymer block of a conjugated diene monomer.
In the modified block copolymer, a plurality of portions where the vinyl aromatic hydrocarbons are uniformly distributed and / or a portion where they are distributed in a tapered shape may coexist. The modified block copolymer used in the present invention may be any mixture of modified block copolymers represented by the above general formula.
The ratio of the vinyl aromatic hydrocarbon polymer block incorporated in the modified block copolymer (referred to as the block ratio of vinyl aromatic hydrocarbon) is less than 50 wt%, preferably 5 to 45 wt% when wear resistance is important. More preferably, it is adjusted to 10 to 40 wt%, and from the viewpoint of maintaining the rigidity of the molded product, it is adjusted to 50 wt% or more, preferably 50 to 97 wt%, more preferably 60 to 95 wt%, and particularly preferably 70 to 92 wt%. It is recommended to do.
The block ratio of the vinyl aromatic hydrocarbon incorporated in the block copolymer is measured by a method of oxidatively decomposing the block copolymer with tertiary butyl hydroperoxide using osmium tetroxide as a catalyst (IM KOLTHOFF, et al., J. Polym. Sci. 1, 429 (1946)) vinyl aromatic hydrocarbon polymer block component (however, the vinyl aromatic hydrocarbon polymer component having an average degree of polymerization of about 10 or less) Can be obtained from the following equation:
Vinyl aromatic hydrocarbon block ratio (wt%)
= (Weight of vinyl aromatic hydrocarbon polymer block in block copolymer)
/ Weight of all vinyl aromatic hydrocarbons in the block copolymer) × 100
In the present invention, the microstructure (ratio of cis, trans, vinyl) of the conjugated diene moiety in the modified conjugated diene polymer or the modified copolymer comprising a conjugated diene monomer and a vinyl aromatic hydrocarbon will be described later. It can be arbitrarily changed by using a polar compound or the like. The vinyl bond content is not particularly limited, but when 1,3-butadiene is used as the conjugated diene monomer, the vinyl bond content is preferably 5 to 90%, more preferably 10 to 80%, and the conjugated diene. When isoprene is used as the system monomer or when 1,3-butadiene and isoprene are used in combination, the amount of vinyl bonds, which is the sum of 1,2-vinyl bonds and 3,4-vinyl bonds, is preferably 3 to 80%, more preferably 5 to 70%. Here, the vinyl bond content is 1 of the conjugated diene monomers incorporated in the polymer in 1,2-bond, 3,4-bond and 1,4-bond bond modes. It is the ratio of those incorporated by 2-bond and 3,4-bond. The vinyl bonds in the modified polymer may be uniformly distributed in the polymer chain, may be distributed in a tapered shape, or two or more polymer blocks having different vinyl bonds may exist. The vinyl bond content can be arbitrarily changed by using a polar compound described later.
However, in the case of using a hydrogenated product of a modified block copolymer, the microstructure is such that when 1,3-butadiene is used as the conjugated diene monomer, the vinyl bond amount is preferably 10 to 80%, More preferably, it is 25 to 75%. When isoprene is used as a conjugated diene monomer or when 1,3-butadiene and isoprene are used in combination, 1,2-vinyl bond and 3,4-vinyl bond It is recommended that the vinyl bond amount, which is the sum of the above, is preferably 5 to 70%. The vinyl bond content based on the conjugated diene monomer in the modified polymer can be known using a nuclear magnetic resonance apparatus (NMR).
In the production of a conjugated diene polymer or a copolymer comprising a conjugated diene monomer and a vinyl aromatic hydrocarbon, when isoprene and 1,3-butadiene are used in combination as the conjugated diene monomer, isoprene and 1, The weight ratio of 3-butadiene is preferably 95/5 to 5/95, more preferably 90/10 to 10/90, and still more preferably 85/15 to 15/85. In particular, when obtaining a rubber composition having excellent low-temperature characteristics, the weight ratio of isoprene to 1,3-butadiene is preferably 49/51 to 5/95, more preferably 45/55 to 10/90, still more preferably. Is recommended to be 40/60 to 15/85. When isoprene and 1,3-butadiene are used in combination, a rubber composition having good mechanical properties can be obtained even in molding at a high temperature.
Next, the modified polymer used in the component (2) of the present invention will be described. The modified polymer can be produced by adding a functional group-containing atomic group by reacting a functional group-containing modifier with a living terminal of a polymer obtained using an organolithium compound as a polymerization catalyst. The functional group-containing atomic group is bonded to at least one polymer chain end of the polymer.
Examples of the functional group of the functional group-containing atomic group bonded to the modified polymer include a hydroxyl group, a carbonyl group, a thiocarbonyl group, an acid halide group, an acid anhydride group, a carboxyl group, a thiocarboxylate group, an aldehyde group, Thioaldehyde group, carboxylic acid ester group, amide group, sulfonic acid group, sulfonic acid ester group, phosphoric acid group, phosphoric ester group, amino group, imino group, cyano group, pyridyl group, quinoline group, epoxy group, thioepoxy group And at least one functional group selected from the group consisting of sulfide groups, isocyanate groups, isothiocyanate groups, silicon halide groups, silanol groups, alkoxysilane groups, tin halide groups, alkoxytin groups, and phenyltin groups. . Of the above functional groups, a hydroxyl group, an epoxy group, an amino group, an imino group, a silanol group, and an alkoxysilane group are particularly preferable.
As a preferred example of an atomic group having at least one functional group selected from the group consisting of a hydroxyl group, an epoxy group, an amino group, an imino group, a silanol group, and an alkoxysilane group, a group consisting of the following formulas (1) to (14) The at least 1 type represented by the formula chosen from more is mentioned.

In the above formulas (1) to (14), N represents a nitrogen atom, Si represents a silicon atom, O represents an oxygen atom, C represents a carbon atom, H represents a hydrogen atom, R ¹ , R ² Each independently represents a hydrogen atom or a hydrocarbon group having 1 to 24 carbon atoms, and the hydrocarbon groups are each independently a hydroxyl group, an epoxy group, an amino group, or a hydrocarbon group having 1 to 24 carbon atoms, if desired. Each group may have at least one functional group selected from the group consisting of an imino group having a group, a silanol group, and an alkoxysilane group having 1 to 24 carbon atoms. ³ Each independently represents a divalent hydrocarbon group having 1 to 48 carbon atoms, and if desired, each independently, a hydroxyl group, an epoxy group, an amino group, an imino group having a hydrocarbon group having 1 to 24 carbon atoms, Each R may have at least one functional group selected from the group consisting of a silanol group and an alkoxysilane group having 1 to 24 carbon atoms. ⁴ Each independently represents a hydrogen atom or a hydrocarbon group having 1 to 24 carbon atoms.
In the present invention, as the modifying agent that can be used to form the functional group-containing atomic group bonded to the modified polymer, a known compound having the functional group and / or a known known compound that can be formed. Compounds can be used. For example, the terminal modification treatment agent described in Japanese Patent Publication No. 4-39495 (corresponding to US Pat. No. 5,115,035) can be used. Specific examples include the following.
Examples of modifiers having functional groups of the above formulas (1) to (6) include tetraglycidyl metaxylenediamine, tetraglycidyl-1,3-bisaminomethylcyclohexane, tetraglycidyl-p-phenylenediamine, and tetraglycidyldiamino. Diphenylmethane, diglycidyl aniline, diglycidyl orthotoluidine, N- (1,3-dibutylbutylidene) -3- (triethoxysilyl) -1-propanamine, 4-di (β-trimethoxysilylethyl) aminostyrene, Examples include 4-di (β-triethoxysilylethyl) aminostyrene, 4-di (γ-trimethoxysilylpropyl) aminostyrene, and 4-di (γ-triethoxysilylpropyl) aminostyrene.
Examples of the modifier having the functional group represented by the formula (7) include cyclic lactones such as ε-caprolactone, δ-valerolactone, butyrolactone, γ-caprolactone, and γ-valerolactone.
Examples of the modifier having the functional group of the formula (8) include 4-methoxybenzophenone, 4-ethoxybenzophenone, 4,4′-bis (methoxy) benzophenone, 4,4′-bis (ethoxy) benzophenone, γ -Glycidoxyethyl trimethoxysilane, (gamma) -glycidoxypropyl trimethoxysilane is mentioned.
Examples of modifiers having the functional groups of the above formulas (9) and (10) include γ-glycidoxybutyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and γ-glycidoxypropyltripropoxysilane. , Γ-glycidoxypropyl tributoxysilane.
Examples of the modifier having the functional group of the formula (11) include 1,3-dimethyl-2-imidazolidinone and 1,3-diethyl-2-imidazolidinone.
Examples of the modifier having the functional group of the above formula (12) include N, N′-dimethylpropylene urea, N-methylpyrrolidone and the like.
The modified polymers having atomic groups having the functional groups of the above formulas (13) and (14) are non-hydrogenated modified polymers having the functional group-containing atomic groups of the above formulas (11) and (12), respectively. Obtained by hydrogenation.
The hydrogenated product of the modified polymer used in the component (2) of the present invention can be produced by modifying the polymer and then hydrogenating it, or can be produced by hydrogenating and then modifying the polymer. it can. For example, when the polymer is modified and then hydrogenated, a modified polymer can be obtained by reacting the living end of the polymer obtained using an organolithium compound as a polymerization catalyst with the above modifier. The modified polymer of hydrogenated product is obtained by hydrogenating the modified polymer.
In addition, as another method for obtaining a modified polymer used in the component (2) of the present invention, an organic alkali metal compound such as an organic lithium compound is reacted (metalation reaction) with the polymer, and the organic alkali metal compound is added. The method of obtaining a polymer and carrying out addition reaction of said modifier to this is mentioned. In this case, it is possible to obtain a hydrogenated modified polymer by obtaining a hydrogenated polymer and then subjecting it to a metallation reaction and reacting with the above modifier.
Depending on the type of modifier, hydroxyl groups and amino groups may be organometallic salts at the stage of reaction of the modifier, but in that case, treatment with a compound having active hydrogen such as water or alcohol. By doing so, a hydroxyl group, an amino group, or the like can be obtained.
In the present invention, the reaction pressure for carrying out the modification reaction is not particularly limited, but is usually 0.2 to 2 MPa, preferably 0.3 to 1 MPa. The reaction temperature is preferably in the range of 0 to 150 ° C, more preferably in the range of 20 to 120 ° C, and still more preferably in the range of 50 to 100 ° C. The time required for the denaturation reaction is generally in the range of 1 second to 10 hours, preferably in the range of 1 second to 3 hours, although it depends on the reaction temperature during adjustment.
In the present invention, a polymer that has not been modified after reacting the polymer with a modifier may be present in the modified polymer. The amount of the unmodified polymer mixed in the modified polymer is preferably 70% by weight or less, more preferably 60% by weight or less, and still more preferably 50% by weight or less based on the weight of the modified polymer.
In the present invention, the hydrogenated product of the modified polymer can be obtained by hydrogenating the modified polymer obtained above. The hydrogenation catalyst is not particularly limited and is conventionally known (1) A supported heterogeneous hydrogenation in which a metal such as Ni, Pt, Pd, or Ru is supported on carbon, silica, alumina, diatomaceous earth, or the like. A catalyst, (2) a so-called Ziegler-type hydrogenation catalyst using an organic acid salt such as Ni, Co, Fe, Cr or a transition metal salt such as acetylacetone salt and a reducing agent such as organic aluminum, (3) Ti, Ru, A homogeneous hydrogenation catalyst such as a so-called organometallic complex such as an organometallic compound such as Rh or Zr is used.
Specific examples of the hydrogenation catalyst include Japanese Patent Publication No. 42-8704, Japanese Patent Publication No. 43-6636, Japanese Patent Publication No. 63-4841, Japanese Patent Publication No. 1-337970, Japanese Patent Publication No. 1-53851, The hydrogenation catalyst described in Japanese Utility Model Publication No. 2-9041 can be used. A preferred hydrogenation catalyst is a mixture with a titanocene compound and / or a reducing organometallic compound. As the titanocene compound, compounds described in JP-A-8-109219 can be used. Specific examples thereof include (substitution) such as biscyclopentadienyl titanium dichloride and monopentamethylcyclopentadienyl titanium trichloride. Examples thereof include compounds having at least one ligand having a cyclopentadienyl skeleton, an indenyl skeleton, or a fluorenyl skeleton. Examples of the reducing organometallic compound include organic alkali metal compounds such as organolithium, organomagnesium compounds, organoaluminum compounds, organoboron compounds, and organozinc compounds.
The hydrogenation reaction is preferably carried out in a temperature range of 0 to 200 ° C, more preferably 30 to 150 ° C. The pressure of hydrogen used for the hydrogenation reaction is preferably 0.1 to 15 MPa, more preferably 0.2 to 10 MPa, and still more preferably 0.3 to 5 MPa. The hydrogenation reaction time is preferably 3 minutes to 10 hours, more preferably 10 minutes to 5 hours. The hydrogenation reaction can be any of a batch process, a continuous process, or a combination thereof.
In the hydrogenated product of the modified polymer used in the present invention, the total hydrogenation rate of the unsaturated double bond based on the conjugated diene monomer unit can be arbitrarily selected according to the purpose and is not particularly limited. When obtaining a hydrogenated product of a modified polymer having good thermal stability and weather resistance, 70% or more of the unsaturated double bond based on the conjugated diene monomer unit in the modified polymer, preferably 80% or more, More preferably, 90% or more is recommended to be hydrogenated. Moreover, only a part may be hydrogenated. When only a part is hydrogenated, the hydrogenation rate is preferably 10% or more and less than 70%, or 15% or more and less than 65%, or more preferably 20% or more and less than 60%. Furthermore, the hydrogenation rate of the vinyl bond based on the conjugated diene monomer before hydrogenation is preferably 85% or more, more preferably 90% or more, and still more preferably 95% or more. Recommended for obtaining an excellent rubber composition. Here, the hydrogenation rate of vinyl bonds refers to the ratio of hydrogenated vinyl bonds among vinyl bonds based on conjugated diene monomers incorporated in the modified polymer before hydrogenation. The hydrogenation rate of the aromatic double bond based on the vinyl aromatic hydrocarbon in the modified random copolymer or modified block copolymer is not particularly limited, but is preferably 50% or less, more preferably 30%. Hereinafter, more preferably 20% or less is recommended. The hydrogenation rate can be known by a nuclear magnetic resonance apparatus (NMR).
Next, in the present invention, a secondary modified polymer obtained by reacting a reactive compound (4) with a functional group bonded to a modified polymer used for preparing a masterbatch can also be used. The secondary modified polymer is obtained by reacting the secondary modifier as the compound (4) with the modified polymer of the present invention, and the secondary modifier is a functional group of the modified polymer. And a compound having a functional group having reactivity.
Preferable examples of the functional group of the secondary modifier as the compound (4) include at least one selected from a carboxyl group, an acid anhydride group, an isocyanate group, an epoxy group, a silanol group, and an alkoxysilane group. A secondary modifier having at least two of the above functional groups is particularly preferred. However, when the functional group is an acid anhydride group, a secondary modifier having only one acid anhydride group is particularly preferable. The amount of the secondary modifier when the secondary polymer is reacted with the modified polymer is usually 0.3 to 10 mol, preferably 0.4 to 5 per equivalent of the functional group bonded to the modified polymer. Mol, more preferably in the range of 0.5 to 4 mol.
The method of reacting the modified polymer with the secondary modifier is not particularly limited, but a known method can be used. Examples thereof include a melt kneading method described later and a method of reacting each component by dissolving or dispersing in a solvent or the like. In the method in which each component is dissolved or dispersed and reacted in a solvent, the solvent is not particularly limited as long as each component is dissolved or dispersed, and aliphatic hydrocarbon, alicyclic hydrocarbon, aromatic carbonization In addition to hydrocarbon solvents such as hydrogen, halogen-containing solvents, ester solvents, ether solvents and the like can be used. In this method, the temperature at which the secondary polymer is reacted with the modified polymer is usually −10 to 150 ° C., preferably 30 to 120 ° C. The time required for the reaction generally depends on the reaction temperature at the time of adjustment, but is usually within 3 hours, preferably several seconds to 1 hour. A particularly preferred method is a method in which a secondary modified polymer is obtained by adding a secondary modifier to the solution of the produced modified polymer and reacting it.
Next, specific examples of the secondary modifier will be described. Examples of secondary modifiers having a carboxyl group include aliphatic acids such as maleic acid, oxalic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, carbaryl acid, cyclohexanedicarboxylic acid, cyclopentanedicarboxylic acid, etc. Carboxylic acids; aromatic carboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, biphenyldicarboxylic acid, trimesic acid, trimellitic acid, and pyromellitic acid.
Examples of secondary modifiers having an acid anhydride group include maleic anhydride, itaconic anhydride, pyromellitic anhydride, cis-4-cyclohexane-1,2-dicarboxylic anhydride, 1,2,4,5 -Benzenetetracarboxylic dianhydride, 5- (2,5-dioxytetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride.
Examples of secondary modifiers having an isocyanate group include toluylene diisocyanate, diphenylmethane diisocyanate, polyfunctional aromatic isocyanate (that is, a compound in which three or more isocyanate groups are bonded to an aromatic ring), and the like. It is done.
Examples of secondary modifiers having an epoxy group include tetraglycidyl-1,3-bisaminomethylcyclohexane, tetraglycidyl-m-xylenediamine, diglycidylaniline, ethylene glycol diglycidyl, propylene glycol diglycidyl, diterephthalate Examples include glycidyl ester acrylate.
Examples of secondary modifiers having a silanol group include hydrolysates of the above alkoxysilane compounds described as modifiers used to obtain modified polymers.
Examples of secondary modifiers having an alkoxysilane group include bis- (3-triethoxysilylpropyl) -tetrasulfane, bis- (3-triethoxysilylpropyl) -disulfane, and ethoxysiloxane oligomers.
Moreover, the functional oligomer which has reactivity can also be used as a secondary modifier. The functional group of the functional oligomer is not particularly limited as long as it is reactive with the functional group bonded to the modified polymer. Preferred examples of the functional oligomer include a functional oligomer having at least one functional group selected from the group consisting of a hydroxyl group, an amino group, a carboxyl group, an acid anhydride group, an isocyanate group, an epoxy group, a silanol group, and an alkoxysilane group. Can be mentioned. The number average molecular weight of these functional oligomers is usually 300 or more and less than 3,0000, preferably 500 or more and less than 15,000, more preferably 1,000 or more and less than 20,000. Specific examples of the functional oligomer include a butadiene oligomer having at least one functional group or a hydrogenated product thereof, an isoprene oligomer having at least one functional group or a hydrogenated product thereof, and ethylene having at least one functional group. Saponified product of oligomer, propylene oligomer having at least one functional group, ethylene oxide oligomer, propylene oxide oligomer, ethylene oxide-propylene oxide copolymer oligomer, styrene-maleic anhydride copolymer oligomer, ethylene-vinyl acetate copolymer oligomer Etc.
Examples of particularly preferred secondary modifiers in the present invention include two or more carboxylic acids having two or more carboxyl groups or acid anhydrides thereof, or acid anhydride groups, isocyanate groups, epoxy groups, silanol groups, and alkoxysilane groups. Specific examples include maleic anhydride, pyromellitic anhydride, 1,2,4,5-benzenetetracarboxylic dianhydride, toluylene diisocyanate, tetraglycidyl-1,3-bis. Examples include aminomethylcyclohexane, bis- (3-triethoxysilylpropyl) -tetrasulfane, and styrene-maleic anhydride copolymer oligomer.
Moreover, when adjusting the masterbatch of a component (2), the secondary modifier which is said compound (4) other than a modified polymer and an inorganic filler can be added. The amount of the secondary modifier is 0.01 to 20 parts by weight, preferably 0.02 to 10 parts by weight, more preferably 0.05 to 7 parts by weight with respect to 100 parts by weight of the modified polymer. .
The weight average molecular weight of the modified polymer or secondary modified polymer used in the component (2) of the present invention is 30,000 or more from the viewpoint of mechanical strength and abrasion resistance of the rubber composition, and 1,200,000 from the viewpoint of workability. It is preferable that it is below, More preferably, it is 50,000-1 million, More preferably, it is the range of 100,000-800,000. The weight average molecular weight of the modified polymer was measured by gel permeation chromatography (GPC), and the molecular weight of the peak of the chromatogram was determined from a standard polystyrene measurement curve (the peak molecular weight of standard polystyrene was used). Can be determined using).
In the modified polymer solution obtained as described above, the catalyst residue can be removed if necessary, and the modified polymer can be separated from the solution. Solvent separation methods include, for example, a method in which a polar solvent that is a poor solvent for a polymer such as acetone or alcohol is added to a solution after polymerization or hydrogenation to precipitate and recover the polymer, or a solution of a modified polymer Can be added to hot water with stirring and the solvent removed by steam stripping, or the polymer solution can be heated directly to distill off the solvent. In addition, stabilizers, such as various phenol type stabilizers, phosphorus type stabilizers, sulfur type stabilizers, and amine type stabilizers, can be added to the modified polymer or hydrogenated product thereof used in the present invention.
In the present invention, the inorganic filler used as the raw material for the masterbatch of component (2) or the inorganic filler of component (3) was produced by a known reinforcing filler such as natural silica, wet method or dry method. Synthetic silica, kaolin, mica, talc, clay, montmorillonite, zeolite, natural silicate, calcium silicate, aluminum silicate and other synthetic silicates, magnesium hydroxide, aluminum hydroxide, calcium hydroxide, barium hydroxide, etc. Metal hydroxide, alumina, titanium oxide, magnesium oxide, metal oxide such as zinc oxide, light calcium carbonate, heavy calcium carbonate, various surface treatment calcium carbonate, metal carbonate such as magnesium carbonate, barium sulfate, sulfuric acid Metal sulfates such as magnesium and calcium sulfate, gold such as aluminum and bronze Flour, at least one component such as carbon black. Preferred inorganic fillers include silica-based inorganic fillers, metal oxides, metal hydroxides, and carbon. Said inorganic filler may be used independently and can also be used in combination of 2 or more type.
Silica-based inorganic filler refers to solid particles whose main component is the chemical formula SiO2, for example, silica, clay, talc, mica, diatomaceous earth, wollastonite, montmorillonite, zeolite, glass fiber, etc. Substances can be used. Further, a silica-based inorganic filler having a hydrophobic surface or a mixture of a silica-based inorganic filler and a non-silica inorganic filler can also be used. In the present invention, silica is preferred. As silica, dry process white carbon, wet process white carbon, synthetic silicate-based white carbon, and what is called colloidal silica can be used. These preferably have a particle size of 0.01 to 150 μm. Further, in the composition of the present invention, in order that silica is dispersed in the composition and the effect of adding silica is sufficiently exhibited, the average dispersed particle diameter is preferably 0.05 to 1 μm, more preferably 0.05 to 0. .5 μm.
Next, the metal oxide refers to solid particles having the chemical formula MxOy (M is a metal atom, x and y are integers of 1 to 6) as the main component, for example, alumina, titanium oxide, magnesium oxide. Zinc oxide or the like can be used. A mixture of a metal oxide and an inorganic filler other than the metal oxide can also be used. The metal hydroxide used in the present invention includes aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, hydrated aluminum silicate, hydrated magnesium silicate, basic magnesium carbonate, hydrotalcite, calcium hydroxide, barium hydroxide, Hydrated inorganic fillers such as hydrates of tin oxide and hydrates of inorganic metal compounds such as borax, among which magnesium hydroxide and aluminum hydroxide are preferred.
As the carbon black, carbon black of each class such as FT, SRF, FEF, HAF, ISAF, SAF and the like can be used, and carbon black having a nitrogen adsorption specific surface area of 50 mg / g or more and a DBP oil absorption of 80 ml / 100 g is preferable.
In the present invention, the amount of the inorganic filler used for the preparation of the master batch of component (2) is 5 to 300 parts by weight, preferably 5 to 200 parts by weight, more preferably 10 to 100 parts by weight of the modified polymer. It is the range of -150 weight part. When the amount of the inorganic filler exceeds 300 parts by weight, the dispersibility of the inorganic filler is poor and the processability of the masterbatch is deteriorated. Moreover, if it is less than 5 weight part, the adhesiveness which is an effect of this invention is inferior.
In the present invention, the amount of the inorganic filler of component (3) is 0.1 to 150 parts by weight, preferably 5 to 100 parts by weight, more preferably 100 parts by weight of the rubbery polymer of component (1). Is 5 to 50 parts by weight. If the blending amount of the inorganic filler exceeds 150 parts by weight, the dispersibility of the inorganic filler is inferior, and the workability and mechanical strength are inferior.
When a silica-based inorganic filler is used in the production of the rubber composition for footwear of the present invention, a silane coupling agent can be used. The silane coupling agent is for tightly interacting the rubber-like polymer and the inorganic filler, and has an affinity group or a binding group for the rubber-like polymer and the inorganic filler, respectively. Is. Specifically, bis- [3- (triethoxysilyl) -propyl] -tetrasulfide, bis- [3- (triethoxysilyl) -propyl] -disulfide, bis- [2- (triethoxysilyl) -ethyl ] -Tetrasulfide, 3-mercaptopropyl-trimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane and the like.
A preferred silane coupling agent has an alkoxysilane and a polysulfide bond in which two or more sulfur are linked. Examples thereof include bis- [3- (triethoxysilyl) -propyl] -tetrasulfide, bis -[3- (triethoxysilyl) -propyl] -disulfide and the like. The compounding quantity of a silane coupling agent is 0.1-30 weight% with respect to a reinforcing filler, Preferably it is 0.5-20 weight%, More preferably, it is 1-15 weight%.
In the masterbatch of the component (2) of the present invention, the functional group present on the surface of the inorganic filler and the modified polymer are obtained by using a modified polymer having a functional group having high affinity with the inorganic filler. Thus, physical interactions such as chemical bonds and hydrogen bonds are effectively expressed, and a rubber composition for footwear having excellent tear strength, wear resistance, and adhesiveness can be obtained.
The manufacturing method of the masterbatch which is a component (2) of this invention is not restrict | limited in particular, A well-known method can be utilized. For example, a kneading method using a general mixer such as a Banbury mixer, a single screw extruder, a twin screw extruder, a conider, a multi-screw extruder, a roll, etc., dissolving and mixing each component Then, a method of removing the solvent by heating is used. A preferred method is a method of kneading each component with a Banbury mixer or a kneader.
There are no restrictions on the order of addition of the modified polymer and inorganic filler in the production of the masterbatch, a method in which all components are mixed in a kneader at once, and each component is divided twice or more into a mixer. The method of kneading in order, the modified polymer is put in a kneader and kneaded, and then the inorganic filler is added and kneaded, the inorganic filler is put in the kneader and kneaded, and then the modified polymer is added and kneaded. A method, a method of continuously putting an inorganic filler in a kneader, and kneading can be employed.
The kneading temperature at the time of producing the master batch is generally 80 to 300 ° C. in order to obtain a master batch having good dispersibility of the inorganic filler by promoting the deterioration of the modified polymer and the interaction between the modified polymer and the inorganic filler. Is preferable, more preferably in the range of 130 to 250 ° C, still more preferably in the range of 150 to 220 ° C. The kneading time is generally preferably 0.2 to 60 minutes, more preferably 0.5 to 30 minutes, more preferably from the viewpoints of dispersibility of the inorganic filler, productivity of the masterbatch, deterioration of the modified polymer, and the like. Preferably it is the range for 1 to 20 minutes.
A particularly preferable method is a method in which the entire amount of the inorganic filler is previously put in a kneader and kneaded, and then the modified polymer is added and kneaded, and the inorganic filler is divided into two or more times and charged into the kneader. In this method, a modified polymer and an inorganic filler are kneaded.
As a method of dividing the inorganic filler into two or more times and putting it in the kneader, it is preferable to add the inorganic filler in two to ten times in consideration of the complexity of the process of producing the master batch, A method of adding in 2 to 5 divided portions is preferred. Specifically, 20 to 80% by weight, preferably 30 to 80% by weight, more preferably 40 to 80% by weight of the inorganic filler is previously charged into the kneader, and the kneading time is 1 second to 60 minutes, preferably After kneading in the range of 0.5 to 30 minutes, more preferably 1 to 20 minutes, the modified polymer is added and the kneading time is 1 second to 60 minutes, preferably 20 seconds to 30 minutes, more preferably 1 Kneading in the range of minutes to 20 minutes, then adding the remaining inorganic filler, and kneading time in the range of 1 second to 60 minutes, preferably 0.5 minutes to 30 minutes, more preferably 1 minute to 20 minutes. It is a method of manufacturing by kneading. As another preferred method, the entire amount of the inorganic filler is previously charged into the kneader, and the kneading time is in the range of 1 second to 60 minutes, preferably 0.5 minutes to 30 minutes, more preferably 1 minute to 20 minutes. There is a method in which after the kneading, the modified polymer is added and the kneading time is 1 second to 60 minutes, preferably 0.5 minutes to 30 minutes, more preferably 1 minute to 20 minutes.
The most important thing for preparing a masterbatch in a particularly preferred form is that at least 20% by weight or more of the inorganic filler 5 to 300 parts by weight is previously put in a kneader and the temperature is 50 to 300 ° C., preferably 70 to 250. The master batch is prepared by kneading in a range of 100 ° C., more preferably in the range of 100 to 200 ° C., and then kneading the remaining components.
The rubber composition for footwear of the present invention comprises a rubber-like polymer (component 1) and a master batch (component 2), or a rubber-like polymer (component 1), a master batch (component 2), and an inorganic filler (component 3). A rubber composition containing The amount of the master batch is 1 to 150 parts by weight, preferably 5 to 100 parts by weight, and more preferably 10 to 70 parts by weight with respect to 100 parts by weight of the rubber-like polymer (component 1).
The production method of the rubber composition for footwear of the present invention is not particularly limited, and a known method can be used. For example, a kneading method using a general mixer such as a Banbury mixer, a single-screw extruder, a twin-screw extruder, a coneer, or a multi-screw extruder is used.
In addition, the production order of the rubber composition for footwear of the present invention is not limited in the order of addition of the respective components, and the method of kneading the components (1), (2) and (3) in a kneader at once. A method of adding the remaining components after preliminarily mixing arbitrary components can be employed. The kneading temperature is preferably 50 to 300 ° C., more preferably 70 to 250 ° C., and still more preferably 100 to 200 ° C., from the viewpoint of thermal deterioration of the rubber-like polymer or modified polymer. The kneading time is generally preferably from 0.2 to 60 minutes, more preferably from the viewpoint of dispersibility of the inorganic filler, productivity of the rubber composition, deterioration of the modified polymer or rubbery polymer, and the like. The range is 5 to 30 minutes, more preferably 1 to 20 minutes.
The rubber composition for footwear of the present invention is characterized by using a master batch excellent in dispersibility of an inorganic filler obtained by kneading a modified polymer and an inorganic filler by the specific production method shown above. Compared with a rubber composition for footwear obtained by kneading a rubbery polymer or modified polymer and an inorganic filler, which has been conventionally performed, the dispersibility of the inorganic filler is improved, and the wear resistance is improved. A rubber composition for footwear excellent in adhesiveness can be obtained. The dispersibility of the inorganic filler in the rubber composition can be confirmed by using a transmission electron microscope, a scanning probe microscope apparatus, or the like.
In the present invention, other optional additives can be blended as necessary. The type of additive is not particularly limited as long as it is generally used for blending rubbery polymers. Zinc flower, stearic acid, vulcanization aid, anti-aging agent, processing aid, behenic acid, zinc stearate, calcium stearate, magnesium stearate, ethylene bisstearamide, lubricant, mold release agent, paraffinic process oil , Naphthenic process oil, aromatic process oil, paraffin, organic polysiloxane, mineral oil and other softeners / plasticizers, hindered phenolic antioxidants, phosphorous heat stabilizers and other antioxidants, hindered amine light Stabilizers, benzotriazole UV absorbers, flame retardants, antistatic agents, organic fibers, glass fibers, carbon fibers, metal whiskers and other reinforcing agents, colorants, other additives or mixtures thereof, "rubber and plastic compounding chemicals "(Edited by Rubber Digest Co., Ltd.).

本発明を詳細にまた特定の実施態様を参照して説明したが、本発明の精神と範囲を逸脱することなく様々な変更や修正を加えることができることは当業者にとって明らかである。
本出願は、２００３年１０月２９日出願の日本特許出願（特願２００３−３６９２５５）に基づくものであり、その内容はここに参照として取り込まれる。The present invention will be described based on examples, but the present invention is not limited to these examples.
[Analytical method of styrene-butadiene rubber]
(1) Amount of bound styrene The amount of bound styrene was determined by comparison with the UV absorption intensity of standard polystyrene using an ultraviolet spectrophotometer (V-520 UV manufactured by JASCO Corporation).
(2) Amount of 1,2-vinyl bond in butadiene Measured with an infrared spectrophotometer (V-520 UV manufactured by JASCO Corporation) and determined by the Hampton method.
(3) Molecular weight Measured by GPC (apparatus: LC10 manufactured by Shimadzu Corporation, column: Shimpac GPC805 + GPC804 + GPC804 + GPC803 manufactured by Shimadzu Corporation). Tetrahydrofuran was used as the solvent, and the measurement was performed at a temperature of 35 ° C. The molecular weight is a weight average molecular weight obtained by using a calibration curve (created using the peak molecular weight of standard polystyrene) obtained by measuring the molecular weight of the peak of the chromatogram from measurement of commercially available standard polystyrene.
(4) Ratio of unmodified polymer 10 mg of a modified polymer and 10 mg of a low molecular weight internal standard polystyrene having a weight average molecular weight of 8000 were dissolved in 20 ml of tetrahydrofurofuran to prepare a sample solution. The sample solution was subjected to GPC measurement by the same method as in (3) above, and the ratio (i) of the modified polymer to standard polystyrene was determined from the obtained chromatogram. Further, the sample solution was subjected to GPC measurement in the same manner as in the above (3) except that a column of Zorbax (silica gel filler), which is a column manufactured by DuPont, USA, was used, and a chromatogram was obtained. The modified polymer is adsorbed on the GPC column using silica gel as a filler, but the unmodified polymer is not adsorbed on the GPC column. From the obtained chromatogram, the unmodified polymer with respect to standard polystyrene is used. The ratio (ii) can be obtained. From the above ratio (i) and ratio (ii), the ratio (%) of the modified polymer in the copolymer after the modification reaction was calculated by the formula: (1−ratio (ii) / ratio (i)) X100. .
[Measurement of physical properties of rubbery polymer composition]
(1) Tensile test Based on JIS K6251, it measured in a 23 degreeC thermostatic chamber.
(2) Tear test Based on JIS K6252, it measured in a 23 degreeC thermostat.
(3) Measurement of hardness Using an ASKER hardness meter Model C manufactured by Kobunshi Keiki Co., Ltd., the hardness was measured at 23 ° C in a constant temperature room.
(4) Transparency Using a Nippon Denshoku Industries Co., Ltd. HAZE meter, NDH-1001DP type, the HAZE value and total light transmittance of a 5 mm thick plate sample were measured.
(5) Abrasion resistance index The abrasion loss of the sample was measured with an Akron-type testing machine, and an index obtained by the following formula was determined as an index of the abrasion resistance.
Index = [(weight loss of sample) / (weight loss of standard sample)] × 100
(6) Adhesion test Peel strength after adhering rubber composition and adherend (leather, nylon, EVA) using water-based primer (AQUACE PR-503) and water-based adhesive (AQUACE W-06) Was measured.
[Preparation of diene polymer]
(Manufacture of SBR-A)
Purified 5.5 kg of purified cyclohexane, 0.40 kg of styrene monomer and 0.45 kg of 1,3-butadiene in a 10 L autoclave equipped with a nitrogen-replaced stirrer. The temperature was raised to 60 ° C. while stirring and 32 g of tetrahydrofuran and n-butyl were added. Lithium 0.83g (15% cyclohexane solution) was added to initiate the polymerization reaction. 0.15 kg of 1,3-butadiene was continuously added to the polymerization system for 5 minutes from the middle of the polymerization to the maximum temperature of 92 ° C. One minute from the maximum temperature of the polymerization, 0.38 mol of tetraglycidyl-1,3-bisaminomethylcyclohexane was added to the n-butyllithium used as the polymerization initiator and reacted to give SBR-A. Obtained. Thereafter, 0.5 parts by weight of 2,6-di-tertbutyl-4-methylphenol as a stabilizer was added to the polymer solution per 100 parts by weight of the rubber, and the solvent was removed with a drum dryer and dried. When the obtained polymer was analyzed, the styrene content was 40% by weight and the vinyl bond content of the butadiene portion was 33% by weight. From the analytical value of the amount of block styrene, no block of styrene was present. The weight average molecular weight was 493,000 and the modification rate was 71%.
(Manufacture of SBR-B)
Purified 5.5 kg of purified cyclohexane, 0.40 kg of styrene monomer and 0.45 kg of 1,3-butadiene in a 10 L autoclave equipped with a nitrogen-replaced stirrer. The temperature was raised to 60 ° C. while stirring and 32 g of tetrahydrofuran and n-butyl were added. Lithium 0.83g (15% cyclohexane solution) was added to initiate the polymerization reaction. 0.15 kg of 1,3-butadiene was continuously added to the polymerization system for 5 minutes from the middle of the polymerization to the maximum temperature of 92 ° C. One minute after the maximum temperature of the polymerization, 1 mol of 1,3-dimethyl-2-imidazolidinone was added to the n-butyllithium used as the polymerization initiator and reacted to obtain SBR-B. . Thereafter, 0.5 parts by weight of 2,6-di-tertbutyl-4-methylphenol as a stabilizer was added to the polymer solution per 100 parts by weight of the rubber, and the solvent was removed with a drum dryer and dried. When the obtained polymer was analyzed, the styrene content was 40% by weight and the vinyl bond content of the butadiene portion was 33% by weight. From the analytical value of the amount of block styrene, no block of styrene was present. The weight average molecular weight was 491,000 and the modification rate was 80%.
(Manufacture of SBR-C)
SBR-B obtained above: 180 g of maleic anhydride, a secondary modifier, was added to O.D. A secondary modified polymer was obtained by blending 1 g and kneading using a closed kneader (with an internal volume of 0.3 liter) equipped with a temperature controller at a kneading temperature of 100 ° C. and a kneading time of 3 minutes.
(Manufacture of SBR-D)
Purified 5.5 kg of purified cyclohexane, 0.40 kg of styrene monomer and 0.45 kg of 1,3-butadiene in a 10 L autoclave equipped with a nitrogen-replaced stirrer. The temperature was raised to 60 ° C. while stirring and 32 g of tetrahydrofuran and n-butyl were added. Lithium 0.83g (15% cyclohexane solution) was added to initiate the polymerization reaction. 0.15 kg of 1,3-butadiene was continuously added to the polymerization system for 5 minutes from the middle of the polymerization to the maximum temperature of 89 ° C. Three minutes after the maximum temperature reached 89 ° C., the polymer solution was taken out and deactivated with 10-fold mol water of n-butyllithium to obtain SBR-C. Thereafter, 0.5 parts by weight of 2,6-di-tertbutyl-4-methylphenol as a stabilizer was added to the polymer solution per 100 parts by weight of the rubber, and the solvent was removed with a drum dryer and dried. When the obtained polymer was analyzed, the styrene content was 40% by weight and the vinyl bond content of the butadiene portion was 33% by weight. From the analytical value of the amount of block styrene, no block of styrene was present. Moreover, the weight average molecular weight was 485,000.
[Production of master batch]
(MB-1)
First, 25 parts of silica was kneaded under the conditions of a filling rate of 65% and a rotor rotational speed of 66/77 rpm, using a closed kneader (with an internal volume of 1.7 liters) attached with a temperature controller using circulating water from the outside. And kneaded for 4 minutes. Next, 75 parts of polymer and 0.15 part of stearic acid were added and kneading was continued for 4 minutes. The temperature of the rubber composition after discharging was 170 ° C. After cooling, the mixture was kneaded again with an open roll set at 50 ° C. to prepare a polymer / silica master batch. Table 1 shows the formulation.
(MB-2, 3, 4, 6)
Using a closed kneader (with an internal volume of 1.7 liters) attached with a temperature control device using circulating water from the outside, 12.5 parts of silica was initially added under the conditions of a filling rate of 65% and a rotor rotational speed of 66/77 rpm. The mixture was put into a kneader and kneaded for 4 minutes. Next, 75 parts of a polymer and 0.15 part of stearic acid were added and kneaded for 3 minutes, and then 12.5 parts of silica was further added and kneading was continued for 3 minutes. The temperature of the rubber composition after discharging was 170 ° C. After cooling, the mixture was kneaded again with an open roll set at 50 ° C. to prepare a polymer / silica master batch. Table 1 shows the formulation.
(MB-5)
Using a closed kneader (with an internal volume of 1.7 liters) attached with a temperature control device using circulating water from the outside, under the conditions of a filling rate of 65% and a rotor rotational speed of 66/77 rpm, 25 parts of silica and 75 parts of polymer 0.15 part of stearic acid was added and kneading was continued for 5 minutes. The temperature of the rubber composition after discharging was 170 ° C. After cooling, the mixture was kneaded again with an open roll set at 50 ° C. to prepare a polymer / silica master batch. Table 1 shows the formulation.
[Examples 1 to 5]
Using a closed kneader (with an internal volume of 1.7 liters) attached with a temperature controller using circulating water from the outside, each component with the formulation shown in Table 2 under the conditions of a filling rate of 65% and a rotor rotational speed of 66/77 rpm Were put into a kneader in a lump and kneaded to obtain a rubber composition. The temperature after discharge was 161 ° C. The rubber composition thus obtained was kneaded with sulfur and a vulcanization accelerator in an open roll set at 70 ° C., and then vulcanized at 160 ° C. for 20 minutes to prepare a test piece. Table 2 shows the physical properties of the vulcanizate. It can be seen that the rubber composition prepared using the master polymer of the modified polymer of the present invention and silica is excellent in tear strength and wear resistance.
[Comparative Examples 1-2]
By the same method as in Example 1, the components were collectively put into a kneader according to the formulation shown in Table 2 and kneaded to obtain a rubbery polymer composition. The temperature after discharge was 160 ° C. The rubber composition thus obtained was kneaded with sulfur and a vulcanization accelerator in an open roll set at 70 ° C., and then vulcanized at 160 ° C. for 20 minutes to prepare a test piece. Table 2 shows the physical properties of the vulcanizate.
[Examples 6 to 12]
Using a closed kneader (with an internal volume of 1.7 liters) attached with a temperature control device using circulating water from the outside, each component with the formulation shown in Table 3 under the conditions of a filling rate of 65% and a rotor rotational speed of 66/77 rpm Were put into a kneader in a lump and kneaded to obtain a rubber composition. The temperature after discharge was 160 ° C. The rubber composition thus obtained was kneaded with sulfur and a vulcanization accelerator in an open roll set at 70 ° C., and then vulcanized at 160 ° C. for 20 minutes to prepare a test piece. Table 3 shows the adhesive strength of the vulcanizate. It can be seen that the rubber composition prepared using the master batch of the modified polymer of the present invention and silica is excellent in adhesiveness.
[Comparative Examples 3 to 4]
By the same method as in Example 6, the respective components were collectively put into a kneader and kneaded according to the formulation shown in Table 3 to obtain a rubber composition. The rubber composition thus obtained was kneaded with sulfur and a vulcanization accelerator in an open roll set at 70 ° C., and then vulcanized at 160 ° C. for 20 minutes to prepare a test piece.

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.
This application is based on a Japanese patent application (Japanese Patent Application No. 2003-369255) filed on Oct. 29, 2003, the contents of which are incorporated herein by reference.

  The rubber composition for footwear of the present invention has excellent tear strength and abrasion resistance, and is extremely excellent in adhesion to nylon, leather, and EVA, which are shoe materials. The composition of the present invention is an extremely effective material as a sole material for various shoes taking advantage of these characteristics. Moreover, it can be processed into molded products of various shapes, and can be used for various parts such as automobile parts (car interior materials, car exterior materials), food packaging containers, household appliances, medical equipment parts, industrial parts, toys and the like.

Claims (16)

Component (1) Rubber-like polymer: 100 parts by weight; and Component (2) Conjugated diene polymer or copolymer composed of conjugated diene monomer and vinyl aromatic hydrocarbon or hydrogenated product thereof. Master batch obtained by kneading 5 to 300 parts by weight of silica-based inorganic filler with 100 parts by weight of at least one modified polymer selected from modified polymers having at least one containing atomic group bonded: 1 to 150 A rubber composition for footwear comprising parts by weight. 2. The footbatch according to claim 1, wherein the component (2) is a master batch obtained by previously charging a total amount of 5 to 300 parts by weight of an inorganic filler into a kneader and kneading and then kneading by adding a modified polymer. Rubber composition. The rubber composition for footwear according to claim 1, wherein the component (2) is a masterbatch obtained by dividing 5 to 300 parts by weight of the inorganic filler twice or more, charging the mixture into a kneader and sequentially kneading. Component (2) is a master batch in which 20 to 80% by weight of the inorganic filler is previously charged in a kneader and kneaded, then the modified polymer is added and kneaded, and the remaining amount of the inorganic filler is added and kneaded. The rubber composition for footwear according to claim 1. The rubber composition for footwear according to claim 1, further comprising 0.1 to 150 parts by weight of an inorganic filler as the component (3). 2. The footwear according to claim 1, wherein the functional group-containing atomic group of the modified polymer is an atomic group having at least one functional group selected from a hydroxyl group, an epoxy group, an amino group, an imino group, a silanol group, and an alkoxysilane group. Rubber composition. The rubber composition for footwear according to claim 1, wherein the modified polymer is a modified polymer in which at least one atomic group selected from the following formulas (1) to (14) is bonded.

(In the above formulas (1) to (14), N represents a nitrogen atom, Si represents a silicon atom, O represents an oxygen atom, C represents a carbon atom, H represents a hydrogen atom, and R ¹ and R ² are each independently a hydrogen atom. Or a hydrocarbon group having 1 to 24 carbon atoms, and the hydrocarbon groups are each independently, optionally, a hydroxyl group, an epoxy group, an amino group, an imino group having a hydrocarbon group having 1 to 24 carbon atoms, It may have at least one functional group selected from the group consisting of a silanol group and an alkoxysilane group having 1 to 24 carbon atoms, and each R ³ is independently a divalent hydrocarbon group having 1 to 48 carbon atoms. And optionally, each independently selected from the group consisting of a hydroxyl group, an epoxy group, an amino group, an imino group having a hydrocarbon group having 1 to 24 carbon atoms, a silanol group, and an alkoxysilane group having 1 to 24 carbon atoms. At least one government official It may have a group, each R ⁴ each independently represents a hydrogen atom or a C24 hydrocarbon group.) When the component (2) is kneaded with the modified polymer and the inorganic filler, the compound (4) having reactivity with the functional group bonded to the modified polymer is further added to 100 parts by weight of the modified polymer. The rubber composition for footwear according to claim 1, which is a masterbatch obtained by adding 0.01 to 20 parts by weight to the rubber. Component (2) is a mixture of the modified polymer and inorganic filler, and further compound (4) having reactivity with the functional group bonded to the modified polymer is added to 100 parts by weight of the modified polymer. The rubber composition for footwear according to claim 1, which is a master batch obtained by kneading 0.01 to 20 parts by weight. The modified polymer used for the component (2) is bonded to the modified polymer with the compound (4) having reactivity with the functional group bonded to the modified polymer. The rubber composition for footwear according to claim 1, which is a modified polymer reacted with 10 to 10 mol. The rubber composition for footwear according to claim 8 or 9, wherein the compound (4) is a compound having a functional group selected from a carboxyl group, an acid anhydride group, an isocyanate group, an epoxy group, a silanol group, and an alkoxysilane group. Component (1) Rubber-like polymer: 100 parts by weight; and Component (2) Conjugated diene polymer or copolymer composed of conjugated diene monomer and vinyl aromatic hydrocarbon or hydrogenated product thereof. Master batch obtained by kneading 5 to 300 parts by weight of silica-based inorganic filler with 100 parts by weight of at least one modified polymer selected from modified polymers having at least one containing atomic group bonded: 1 to 150 A method for producing a rubber composition for footwear, comprising a step of kneading parts by weight. The rubber for footwear according to claim 12, wherein the component (2) is a masterbatch obtained by adding the total amount of 5 to 300 parts by weight of an inorganic filler into a kneader and kneading, and then kneading by adding a modified polymer. A method for producing the composition. The method for producing a rubber composition for footwear according to claim 12, wherein component (2) is a masterbatch obtained by dividing 5 to 300 parts by weight of an inorganic filler twice or more, charging the mixture into a kneader and sequentially kneading. . The method for producing a masterbatch according to claim 1, wherein 5 to 300 parts by weight of the inorganic filler is put into a kneader and kneaded, and then the modified polymer is added and kneaded. The master batch according to claim 1, wherein 20 to 80% by weight of the inorganic filler is previously charged in a kneader and kneaded, then the modified polymer is added and kneaded, and the remaining amount of the inorganic filler is added and kneaded. Manufacturing method.