JP5800285B2 - Rubber composition and crosslinked product obtained by crosslinking - Google Patents

Description

  The present invention relates to a rubber composition containing an organosilicon compound having a specific structure and a crosslinked product obtained by crosslinking the rubber composition.

  In recent years, various silica compounded rubber products such as anti-vibration rubbers and various rubber rolls have been widely used, including a silica compounded tire excellent in fuel saving and braking performance. However, when silica is blended, the viscosity of the rubber composition is greatly increased. Therefore, a method of alleviating the viscosity increase by blending a silane coupling agent is generally employed. Silane coupling agents are known to reduce the interaction between silicas by reacting with silanols on the silica surface, thereby reducing the loss tangent and dynamic modulus of rubber. However, existing polysulfide-based silane coupling agents that are frequently used especially for tire applications cause scorch due to the influence of sulfur during kneading, and cannot perform kneading at a high temperature, thereby impairing productivity. Furthermore, in recent years, the compounding amount of silica in rubber has increased, and there has been a problem of an increase in compound viscosity. Therefore, reducing the viscosity of the compound has become one of the major issues.

  In addition, amino silane coupling agents and the like that are generally used for resin applications, etc., form a chemical bond only with a specific rubber type. Natural rubber used in tires and diene rubbers such as SBR and BR And do not form chemical bonds.

  In order to solve the above problem, protection of a mercapto-based silane coupling agent has been proposed, but there are many problems from the viewpoint of economical efficiency and compound shrinkage. (See Patent Document 1)

  Patent Document 2 proposes a coupling agent effective for reducing the viscosity of the compound, but there is no effect in terms of scorching during kneading, and Patent Document 3 aims to improve the compound viscosity and dispersibility. Attempts have been made to add tertiary alkylamines, but sulfide coupling agents are mainly used, so the problem of scorch during kneading cannot be solved, and it is expensive and does not chemically bond to rubber. There are problems such as the possibility of adverse effects such as bleeding.

Published patent publication, 2008-110997 Published patent publication, 2005-8639 Published Patent Publication, 2006-249387

  In view of the above points, an object of the present invention is to provide a rubber composition excellent in scorch property, low viscosity property, and compression set during kneading, and a crosslinked product thereof.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by a rubber composition containing an organosilicon compound having a specific structure and a crosslinked product thereof.

（式［１］中、繰り返し単位中のＲ^１、Ｒ^２、Ｒ^３、Ｒ^４及びＲ^５は独立して同一でも異なっていてもよく、Ｒ^１及びＲ^３は炭素数１〜１８の置換もしくは非置換の二価のアルキル基、又は炭素数６〜１８の二価の置換もしくは非置換のフェニル基であり、Ｒ^２、Ｒ^４及びＲ^５は炭素数２〜１８である架橋剤と結合する一価の有機基、炭素数１〜１８の置換もしくは非置換の一価のアルキル基、水素のいずれかであり、Ｒ^６は炭素数２〜１８である架橋剤と結合する一価の有機基、炭素数１〜１８の置換もしくは非置換の一価のアルキル基、水素のいずれかであり、Ｒ^２、Ｒ^４、Ｒ^５、Ｒ^６、の少なくとも一つは架橋剤と結合する基を含む有機基である。繰り返し単位ｐ、ｑは１≦ｐ＋ｑ≦６を満たし、各繰り返し単位はランダムであってよい。Ｘ⁻は陰イオンであり、塩化物イオンであることが好ましい。） That is, the present invention is a rubber composition containing a rubber, a silica-based filler, a silane coupling agent containing a group that reacts with a silica-based filler and a group having a nitrogen atom and a group that binds to a crosslinking agent, The group having an atom and a group bonded to a crosslinking agent is preferably a group represented by the general formula [1].

(In the formula [1], R ¹ , R ² , R ³ , R ⁴ and R ⁵ in the repeating unit may be the same or different independently, and R ¹ and R ³ are substituted with 1 to 18 carbon atoms. Or an unsubstituted divalent alkyl group or a divalent substituted or unsubstituted phenyl group having 6 to 18 carbon atoms, and R ² , R ⁴ and R ⁵ are bonded to a crosslinking agent having 2 to 18 carbon atoms. A monovalent organic group, a substituted or unsubstituted monovalent alkyl group having 1 to 18 carbon atoms, or hydrogen, and R ⁶ is a monovalent organic bonded to a crosslinking agent having 2 to 18 carbon atoms. A group, a substituted or unsubstituted monovalent alkyl group having 1 to 18 carbon atoms, or hydrogen, and at least one of R ² , R ⁴ , R ⁵ , and R ⁶ is a group that binds to a crosslinking agent. The repeating units p and q satisfy 1 ≦ p + q ≦ 6, and each repeating unit is May be a dumb .X ^- is an anion, preferably a chloride ion).

  In the present invention, the group that reacts with the crosslinking agent is preferably an organic group containing a carbon-carbon double bond, and more preferably a vinyl group, an allyl group, an acryloyl group, or a methacryloyl group.

  The group that reacts with the silica-based filler in the silane coupling agent containing a group that reacts with the silica-based filler and a group that has a nitrogen atom and a group that binds to the crosslinking agent is a Si—O—C bond and / or Si—O. A group having a —H bond is preferred.

The silica-based filler used in the present invention is preferably wet silica having a BET specific surface area of 20 to 300 m ² / g. It is preferable that content of a silica type filler is 5-200 weight part with respect to 100 weight part of rubber | gum.

  In the present invention, the content of the silane coupling agent containing a group having a group that reacts with a silica-based filler, a nitrogen atom, and a group that binds to a crosslinking agent is 0.1 to 30 parts by weight with respect to 100 parts by weight of rubber. It is preferable that

  In the present invention, further, a vinyl silane coupling agent, an amino silane coupling agent, an alkyl silane coupling agent, an epoxy silane coupling agent, a methacryloxy silane silane coupling agent, and a (poly) sulfide silane. A silane coupling agent selected from coupling agents and mercaptosilane-based silane coupling agents may be used in combination, and the content of these silane coupling agents is 0.1 to 30 parts by weight with respect to 100 parts by weight of rubber. It is preferable that

  In the present invention, the rubber is preferably a diene rubber.

  In the present invention, it is preferable that a crosslinking agent is further contained, and the crosslinking agent is preferably at least one selected from sulfur, selenium, organic peroxide, morpholine disulfide, thiuram compound, and oxime compound.

  The crosslinked product obtained by crosslinking using the rubber composition of the present invention can be used in applications such as tires and vibration-proof rubbers.

  Furthermore, the rubber composition of the present invention is a mixture containing 100 to 200 parts by weight of silica and 5 to 200 parts by weight of silica and 0.1 to 30 parts by weight of an organosilicon compound having a specific structure. Silica-containing rubber composition obtained by kneading at ℃, fillers such as carbon black and calcium carbonate, processing aids such as stearic acid, other silane coupling agents, anti-aging agents, and crosslinking promotion as necessary An agent, a crosslinking agent, etc. can be used, and it can bridge | crosslink at 130-230 degreeC.

  The rubber composition according to the present invention can increase the kneading temperature when kneading rubber, silica and a silane coupling agent, and can shorten the time required for the kneading operation.

  In addition, since a sufficient coupling effect is obtained in the kneading step, the crosslinked product of the composition is obtained as a low rolling resistant rubber crosslinked product.

The diagram which shows the viscosity behavior (torque value) at 180 degreeC of the compound containing the silane coupling agent (Example) and other silane coupling agent (comparative example) of this invention.

  Hereinafter, the rubber composition according to the present invention will be described in detail. The rubber composition of the present invention contains at least a rubber, a silica-based filler, a silane coupling agent containing a group having a group that reacts with the silica-based filler and a group that binds to a nitrogen atom and a crosslinking agent. The rubber composition of the present invention may be in a slurry state, or may be a master batch (so-called wet master batch) prepared by solidifying the slurry.

  Examples of the rubber used in the present invention include natural rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber, ethylene propylene terpolymer, butyl rubber, acrylonitrile butadiene rubber, chloroprene rubber, epichlorohydrin rubber, silicon rubber, fluorine rubber, and polysulfide rubber. Particularly preferred are diene rubbers such as natural rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber, ethylene propylene terpolymer, butyl rubber, acrylonitrile butadiene rubber, and chloroprene rubber. These rubbers may be used alone or in a blend of two or more.

Examples of the silica-based filler used in the present invention include clay, mica, dry silica, and wet silica, but wet silica having a BET specific surface area of 10 to 400 m ² / g is preferable, and a BET specific surface area of 20 to 300 m ^2. / G wet silica is more preferable, and wet silica having a BET specific surface area of 50 to 250 m ² / g is particularly preferable. If the BET specific surface area is in these ranges, the reinforcing property to rubber is good, and the reactivity between the silica-based filler and the silane coupling agent is also good. Examples of the silica-based filler used in the present invention include Tosoh Silica Corporation, Nipsil VN-3, AQ, ER, E743, Rhodia Corporation Zeosyl 1165MP, 115MP, Premium 200, Degussa Corporation Ultrazil VN3, VN2, 7000G. Commercially available silica-based fillers are used.

  The content of the silica-based filler is preferably 5 to 200 parts by weight, more preferably 10 to 150 parts by weight, and more preferably 20 to 120 parts by weight with respect to 100 parts by weight of rubber. Particularly preferred. If it is this range, it is preferable at the point of the workability of a rubber composition, and the reinforcement | strengthening property of a crosslinked material.

  In the present invention, a silane coupling agent containing a group that reacts with a silica-based filler and a group having a nitrogen atom and a group that binds to a crosslinking agent is used. The silane coupling agent of the present invention may have at least one group each having a group that reacts with a silica-based filler, a nitrogen atom, and a group that binds to a crosslinking agent. In the present invention, a silane coupling agent containing a group that reacts with a silica-based filler and a group that has a nitrogen atom and a group that binds to a crosslinking agent may be used alone or as a mixture of two or more. May be. In the present invention, the silane coupling agent is a compound composed of an organic substance and silicon, and is a compound having two or more different reactive groups in the molecule.

（式［１］中、繰り返し単位中のＲ^１、Ｒ^２、Ｒ^３、Ｒ^４及びＲ^５は独立して同一でも異なっていてもよく、Ｒ^１及びＲ^３は炭素数１〜１８の置換もしくは非置換の二価のアルキル基、又は炭素数６〜１８の二価の置換もしくは非置換のフェニル基であり、Ｒ^２、Ｒ^４及びＲ^５は炭素数２〜１８である架橋剤と結合する一価の有機基、炭素数１〜１８の置換もしくは非置換の一価のアルキル基、水素のいずれかであり、Ｒ^６は炭素数２〜１８である架橋剤と結合する一価の有機基、炭素数１〜１８の置換もしくは非置換の一価のアルキル基、水素のいずれかであり、Ｒ^２、Ｒ^４、Ｒ^５、Ｒ^６、の少なくとも一つは架橋剤と結合する基を含む有機基である。繰り返し単位ｐ、ｑは１≦ｐ＋ｑ≦６を満たし、各繰り返し単位はランダムであってよい。Ｘ⁻は陰イオンである。） The group having a nitrogen atom and a group that binds to the crosslinking agent in the silane coupling agent of the present invention may have at least one group that binds to the nitrogen atom and the crosslinking agent, and is represented by the general formula [1]. It is preferably a group.

(In the formula [1], R ¹ , R ² , R ³ , R ⁴ and R ⁵ in the repeating unit may be the same or different independently, and R ¹ and R ³ are substituted with 1 to 18 carbon atoms. Or an unsubstituted divalent alkyl group or a divalent substituted or unsubstituted phenyl group having 6 to 18 carbon atoms, and R ² , R ⁴ and R ⁵ are bonded to a crosslinking agent having 2 to 18 carbon atoms. A monovalent organic group, a substituted or unsubstituted monovalent alkyl group having 1 to 18 carbon atoms, or hydrogen, and R ⁶ is a monovalent organic bonded to a crosslinking agent having 2 to 18 carbon atoms. A group, a substituted or unsubstituted monovalent alkyl group having 1 to 18 carbon atoms, or hydrogen, and at least one of R ² , R ⁴ , R ⁵ , and R ⁶ is a group that binds to a crosslinking agent. The repeating units p and q satisfy 1 ≦ p + q ≦ 6, and each repeating unit is It may be a dumb .X ^- is an anion).

In General Formula [1], R ¹ and R ³ are a substituted or unsubstituted divalent alkyl group having 1 to 8 carbon atoms, or a substituted or unsubstituted divalent phenyl group having 6 to 12 carbon atoms. It is more preferable that it is a C2-C4 bivalent substituted or unsubstituted alkyl group, or a C6-C8 substituted or unsubstituted bivalent phenyl group.
In the general formula [1], R ² , R ⁴ and R ⁵ are a monovalent organic group bonded to a crosslinking agent having 2 to 8 carbon atoms, and a monovalent substituted or unsubstituted alkyl group having 1 to 12 carbon atoms. Any one of hydrogen, a monovalent organic group bonded to a crosslinking agent having 2 to 4 carbon atoms, a substituted or unsubstituted monovalent alkyl group having 1 to 8 carbon atoms, and hydrogen It is more preferable that
In the general formula [1], R ⁶ is any one of a monovalent organic group bonded to a crosslinking agent having 2 to 8 carbon atoms, a substituted or unsubstituted monovalent alkyl group having 1 to 12 carbon atoms, and hydrogen. Preferably, it is preferably a monovalent organic group bonded to a crosslinking agent having 2 to 4 carbon atoms, a monovalent substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, or hydrogen. .
Examples of the substitutable atom and substituent include alkyl groups such as methyl, ethyl and isopropyl, aryl groups such as phenyl, aralkyl groups such as benzyl, unsaturated hydrocarbon groups such as vinyl, fluorine, chlorine, bromine and iodine. A halogen atom, an amino group, a nitro group, etc. are mentioned.
In the general formula [1], the repeating units p and q are 0 ≦ p and 0 ≦ q, and satisfy 1 ≦ p + q ≦ 6, but preferably 1 ≦ p + q ≦ 5, and 1 ≦ p + q. More preferably, ≦ 4.

  The group bonded to the crosslinking agent is preferably a group containing a carbon-carbon double bond, particularly preferably a vinyl group, an allyl group, an acryloyl group, or a methacryloyl group.

In the general formula [1], X ⁻ is an anion, preferably a chloride ion, a bromide ion, an iodide ion, a sulfate ion, or a carboxylate ion, and more preferably a chloride ion. Examples of the compound having such a structure include hydrochloride of diallylaminopropyltriethoxysilane and triethoxysilylpropyltriallylammonium chloride.

  Specific examples of the group having one nitrogen atom and a group bonded to a crosslinking agent in the silane coupling agent of the present invention are allylaminopropyl group, diallylaminopropyl group, allylbutylaminopropyl group, allylbenzoylaminopropyl group. , Vinylaminopropyl group, divinylaminopropyl group, butylvinylaminopropyl group, vinylbenzoylaminopropyl group, allylvinylaminopropyl group, aminoethylallylaminopropyl group, allylaminoethylallylaminopropyl group, diallylaminoethylallylaminopropyl Group, allylaminoethylaminopropyl group, aminoethylvinylaminopropyl group, vinylaminoethylvinylaminopropyl group, divinylaminoethylvinylaminopropyl group, allylaminoethylvinyl Minopropyl group, diallylaminoethylvinylaminopropyl group, vinylaminoethylallylaminopropyl group, divinylaminoethylallylaminopropyl group, aminoethylallylaminoethylallylaminopropyl group, allylaminoethylallylaminoethylallylaminopropyl group, propylacrylamide Group, propylmethacrylamide group, and salts thereof. Preferably allylaminopropyl group, diallylaminopropyl group, allylbutylaminopropyl group, allylbenzoylaminopropyl group, vinylaminopropyl group, divinylaminopropyl group, butylvinylaminopropyl group, vinylbenzoylaminopropyl group, diallylaminoethylallyl Aminopropyl group, allylaminoethylaminopropyl group, allylaminoethylvinylaminopropyl group, vinylaminoethylallylaminopropyl group, divinylaminoethylallylaminopropyl group, divinylaminoethylvinylaminopropyl group, propylacrylamide group, propylmethacrylamide Groups, and salts thereof.

  The group that reacts with the silica-based filler in the silane coupling agent of the present invention is preferably a group having a Si—O—C bond and / or a Si—O—H bond, specifically an alkoxysilyl group, Examples thereof include, but are not limited to, a silanol group and a polyalkylene glycol monoalkylsilyl group.

（式［２］中、Ａは窒素原子及び架橋剤と結合する基を有する一価の基を表し、Ｒ^７、Ｒ^８、Ｒ^９はそれぞれ同一であっても異なっていてもよく、炭素数１〜１８の置換もしくは非置換の一価のアルキル基、炭素数１〜１８の一価のアルコキシ基、ヒドロキシ基、ＣｎＨ_２ｎ−１Ｏ−（（ＣＨ₂）_ｍＯ）_ｒで表されｎは１〜１８、ｍは１〜６、ｒは１〜１８であるポリアルキレングリコールモノアルキルエーテル基のいずれかであり、Ｒ^７、Ｒ^８、Ｒ^９の少なくとも１つは炭素数１〜１８の一価のアルコキシ基、もしくはヒドロキシ基、もしくはＣｎＨ_２ｎ−１Ｏ−（（ＣＨ₂）_ｍＯ）_ｒで表されnは１〜１８、ｍは１〜６、ｒは１〜１８であるポリアルキレングリコールモノアルキルエーテル基のいずれかである。） Specific examples of the silane coupling agent having a group that reacts with the silica-based filler and a group that binds to a nitrogen atom and a crosslinking agent in the present invention have structures represented by general formulas [2] and [3]. Compounds. In the general formulas [2] and [3], A represents a group having a nitrogen atom and a group bonded to a crosslinking agent, and examples thereof include the group bonded to the nitrogen atom and the crosslinking agent described above.

(In Formula [2], A represents a monovalent group having a nitrogen atom and a group bonded to a crosslinking agent, and R ⁷ , R ⁸ and R ⁹ may be the same or different, and 1 to 18 substituted or unsubstituted monovalent alkyl group, C1 to C18 monovalent alkoxy group, hydroxy group, CnH _2n-1 O — ((CH ₂ ) _m O) _r and n is 1 to 18, m is 1 to 6, and r is any one of polyalkylene glycol monoalkyl ether groups having 1 to 18, and at least one of R ⁷ , R ⁸ , and R ⁹ is one having 1 to 18 carbon atoms. A polyalkylene glycol represented by a valent alkoxy group, a hydroxy group, or CnH _2n-1 O — ((CH ₂ ) _m O) _r , wherein n is 1 to 18, m is 1 to 6, and r is 1 to 18. Any of monoalkyl ether groups.)

In the general formula [2], R ⁷ , R ⁸ and R ⁹ are each a substituted or unsubstituted monovalent alkyl group having 1 to 8 carbon atoms, a monovalent alkoxy group having 1 to 8 carbon atoms, CnH _2n-1 O. -((CH ₂ ) _m O) It is more preferable that it is any one of polyalkylene glycol monoalkyl ether groups represented by _r , wherein n is 1 to 8, m is 1 to 4, and r is 1 to 8. A substituted or unsubstituted monovalent alkyl group having 1 to 4 carbon atoms, a monovalent alkoxy group having 1 to 4 carbon atoms, CnH _2n-1 O — ((CH ₂ ) _m O) _{r and} n is 2 to 2 8 and m are particularly preferably any of polyalkylene glycol monoalkyl ether groups in which 2 to 4 and r is 1 to 6.
Examples of the substitutable atom and substituent include alkyl groups such as methyl, ethyl and isopropyl, aryl groups such as phenyl, aralkyl groups such as benzyl, unsaturated hydrocarbon groups such as vinyl, fluorine, chlorine, bromine and iodine. A halogen atom, an amino group, a nitro group, etc. are mentioned.

（式［３］中、Ａは窒素原子及び架橋剤と結合する基を有する一価の基を表し、Ｒ^１０は炭素数１〜１８の置換もしくは非置換の一価のアルキル基、炭素数１〜１８の一価のアルコキシ基、ヒドロキシ基、ＣｎＨ_２ｎ−１Ｏ−（（ＣＨ₂）_ｍＯ）_ｒで表されｎは１〜１８、ｍは１〜６、ｒは１〜１８であるポリアルキレングリコールモノアルキルエーテル基のいずれかであり、Ｒ^１１、Ｒ^１２は互いに同一でも異なっていてもよく、直鎖であっても分岐していてもよい炭素数１〜８の二価の置換もしくは非置換のアルキル基であり、Ｗは−Ｃ（=Ｏ）−、−Ｏ−、−ＮＲ^１３−、−ＣＲ^１４Ｒ^１５−のいずれかであり、Ｒ^１３、Ｒ^１４、Ｒ^１５は炭素数１〜１８の置換又は非置換のアルキル基、水素のいずれかである。）

(In Formula [3], A represents a monovalent group having a nitrogen atom and a group bonded to a crosslinking agent, R ¹⁰ is a substituted or unsubstituted monovalent alkyl group having 1 to 18 carbon atoms, 1 carbon atom. To 18 monovalent alkoxy groups, hydroxy groups, CnH _2n-1 O — ((CH ₂ ) _m O) _r , wherein n is 1 to 18, m is 1 to 6, and r is 1 to 18. Any one of alkylene glycol monoalkyl ether groups, and R ¹¹ and R ¹² may be the same or different from each other, and may be linear or branched divalent substituents having 1 to 8 carbon atoms or An unsubstituted alkyl group, W is any of —C (═O) —, —O—, —NR ¹³ —, —CR ¹⁴ R ¹⁵ —, and R ¹³ , R ¹⁴ , and R ¹⁵ are each a carbon number. 1 to 18 substituted or unsubstituted alkyl groups or hydrogen.)

In the general formula [3], R ¹⁰ represents a substituted or unsubstituted monovalent alkyl group having 1 to 8 carbon atoms, a monovalent alkoxy group having 1 to 8 carbon atoms, CnH _2n-1 O — ((CH ₂ ). _m O) It is more preferably any one of polyalkylene glycol monoalkyl ether groups represented by _r , where n is 1 to 8, m is 1 to 4, and r is 1 to 8, A polyalkylene glycol monoalkyl ether group represented by a valent alkoxy group or CnH _2n-1 O — ((CH ₂ ) _m O) _r , wherein n is 2 to 8, m is 2 to 4, and r is 1 to 6. It is particularly preferable that either one is used.
In the general formula [3], R ¹¹ and R ¹² are preferably a divalent substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, and a divalent substituted or unsubstituted alkyl group having 1 to 4 carbon atoms. More preferably, it is a group.
In the general formula [3], R ¹³ , R ¹⁴ , and R ¹⁵ are each preferably a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms or hydrogen, and are substituted or unsubstituted having 1 to 4 carbon atoms. It is more preferable that the alkyl group is any one of hydrogen and hydrogen.
Examples of the substitutable atom and substituent include alkyl groups such as methyl, ethyl and isopropyl, aryl groups such as phenyl, aralkyl groups such as benzyl, unsaturated hydrocarbon groups such as vinyl, fluorine, chlorine, bromine and iodine. A halogen atom, an amino group, a nitro group, etc. are mentioned.

  The silane coupling agent of the present invention may have a structure crosslinked with a divalent or higher alcohol derivative. Specifically, a compound having a structure represented by two or more molecules of the general formula [2] or [3], or a compound having a structure represented by one or more molecules of the general formula [2] and one or more molecules of general It may have a crosslinked structure in which the formula [3] and a divalent or higher-valent alcohol derivative (for example, 1,4-butanediol) are condensed, specifically diallylaminopropyltriethoxysilane and 1,4-butanediol. In this reaction, the silane portion may have a crosslinked structure as shown by the formula [2], in which two silane units and one molecule of 1,4-butanediol are condensed. In addition, one or more molecules of the compound having the structure represented by the general formulas [2] and [3] and one or more molecules of a vinyl silane coupling agent, an amino silane coupling agent, an alkyl silane coupling agent, an epoxy Organic silicon compounds such as silane coupling agents, methacryloxy silane coupling agents, mercapto silane coupling agents, (poly) sulfide silane coupling agents, and divalent or higher alcohol derivatives (for example, 1,4-butanediol) A condensed cross-linked structure may be used, and specifically, a structure in which diallylaminopropyltriethoxysilane, vinyltriethoxysilane, and 1,4-butanediol are reacted to form a cross-linked structure may be used. In particular, a crosslinked structure with a mercapto-based silane coupling agent or a (poly) sulfide-based silane coupling agent which is a silane coupling agent containing sulfur is preferable.

As the vinyl silane coupling agent of the present invention, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, allyltrichlorosilane, allyltrimethoxysilane, allyltriethoxysilane, diethoxymethylvinylsilane, Examples include trichlorovinylsilane and triethoxyvinylsilane.
Examples of the amino silane coupling agent of the present invention include 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2- Examples include aminoethyl) -3-aminopropylmethyldimethoxysilane, 3- (N-phenyl) aminopropyltrimethoxysilane, and the like.
Examples of the alkyl-based silane coupling agent of the present invention include methyltrimethoxysilane, dimethyldiethoxysilane, propyltriethoxysilane, hexyltrimethoxysilane, octyltriethoxysilane, hexamethyldisilazane, and phenyltrimethoxysilane. The
Examples of the epoxy silane coupling agent of the present invention include 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropyltriethoxysilane. The
Examples of the methacryloxy silane coupling agent of the present invention include 3-methacryloxypropyltriethoxysilane and 3-methacryloxypropyltrimethoxysilane.
Examples of the mercapto silane coupling agent of the present invention include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-octanoylthio-1-propyltriethoxysilane and the like.
Examples of the (poly) sulfide-based silane coupling agent of the present invention and the polysulfide-based silane coupling agent represented by the general formula [I] include bis (3-triethoxysilylpropyl) disulfide (abbreviated as TESPD), bis (3 -Triethoxysilylpropyl) tetrasulfide (abbreviation TESPT) is particularly preferred.
_{^{(R 16 -O) 3-Y}} R 16 -Si-R 17 -Sx-R 17 -Si-R 16 (O-R 16) 3-Y [I]
(In the formula, R ¹⁶ is a monovalent hydrocarbon group having 1 to 18 carbon atoms, R ¹⁷ is a divalent hydrocarbon group having 1 to 9 carbon atoms, x is 2 to 6, _Y is 0, 1, or 2) Is an integer.)

  The silane coupling agent of the present invention may be used as a mixture with a compound that does not have a group bonded to a nitrogen atom and a crosslinking agent (that is, has a group showing a structure other than A). Examples of the compound having no nitrogen atom and a group capable of binding to the crosslinking agent (that is, having a group other than A) include trimethoxysilane, triethoxysilane, diethoxymethylsilane, dimethoxymethylsilane, and trimethoxysilane. Products of polyethylene glycol monoalkyl ethers (ethylene glycol repeating units 1-8, monoalkyl ethers having 1-18 carbon atoms), reaction products of triethoxysilane and polyethylene glycol monoalkyl ethers (The repeating unit of ethylene glycol is 1 to 8, the carbon number of monoalkyl ether is 1 to 18), the reaction product of dimethoxymethylsilane and polyethylene glycol monoalkyl ether (the repeating unit of ethylene glycol is 1 to 8, Alkyl ether has 1 to 1 carbon atoms ), A reaction product of trimethoxysilane and polypropylene glycol monoalkyl ether (propylene glycol has 1 to 8 repeating units, monoalkyl ether having 1 to 18 carbon atoms), trimethoxysilane and 2-methyl-1, A reaction product of 3-propanediol, a reaction product of triethoxysilane and 2-methyl-1,3-propanediol, a reaction product of dimethoxymethylsilane and 2-methyl-1,3-propanediol, Reaction product of trimethoxysilane and N-methyl-N, N-diethanolamine, reaction product of dimethoxymethylsilane and N-methyl-N, N-diethanolamine, dimethoxymethylsilane and N-butyl-N, N- Reaction product with diethanolamine, trimethoxysilane and N, N-dimethylethanol Reaction product of amine, reaction product of dimethoxymethylsilane and N, N-dimethylethanolamine, reaction product of dimethoxymethylsilane and N, N-dibutylethanolamine, dimethoxymethylsilane and 1,4-butane Examples include a reaction product of diol, a reaction product of trimethoxysilane and neopentyl glycol, a reaction product of trimethoxysilane and glycerin, a reaction product of trimethoxysilane and pentaerythritol, and the like.

  Although the manufacturing method of the silane coupling agent containing the group which has the group which reacts with the silica type filler of this invention, the nitrogen atom, and a crosslinking agent is not specifically limited, For example, it is a silane coupling agent which has an amino group. A method of reacting an acid chloride having a carbon-carbon double bond such as allyl halide, vinyl halide, methacrylic acid chloride, acrylic acid chloride, or ammonia, alkylated amine, etc. and allyl halide, vinyl halide, A method in which an acid chloride having a carbon-carbon double bond such as methacrylic acid chloride or acrylic acid chloride is reacted to synthesize allylamine, diallylamine, methacryloxyamine, etc., and this is reacted with a halogenated alkylalkoxysilane, diallylaminopropyl With hydrochlorides such as triethoxysilane A method of reacting the group of compounds. Specifically, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldimethoxymethylsilane, aminoethylaminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane and 2-methyl-1, A method of reacting aminosilanes such as reaction products with 3-propanediol with allyl chloride, allyl bromide, vinyl chloride, methacrylic acid chloride, acrylic acid chloride, and amines such as allylamine, diallylamine, methacryloxyamine, and 3 -Alkoxyalkoxy halides such as chloropropyltriethoxysilane, 3-chloropropyltrimethoxysilane, the reaction product of 3-chloropropyltrimethoxysilane and 2-methyl-1,3-propanediol How obtained by reacting orchids, and a method obtained by reacting the hydrochloride salt and triethyl or diallyl aminopropyltriethoxysilane are exemplified. In this reaction, a catalyst or an acid acceptor may be used. Moreover, you may perform reaction which modifies an alkoxy group by making N-methyl-N, N-diethanolamine, 2-methyl-1,3-propanediol, etc. react with the obtained compound.

  The content of the silane coupling agent containing a group reacting with the silica-based filler of the present invention and a group having a nitrogen atom and a group bonded to a crosslinking agent is 0.1 to 30 parts by weight with respect to 100 parts by weight of rubber. Yes, preferably 1 to 20 parts by weight, more preferably 1 to 10 parts by weight. If it is this range, the effect of the silane coupling agent containing the group which reacts with a silica type filler and the group which couple | bonds with a nitrogen atom and a crosslinking agent will be acquired enough, and compression of the crosslinked material obtained by bridge | crosslinking Good properties such as permanent set.

In the present invention, other silane coupling agents may be used in combination. The silane coupling agent used in combination is not particularly limited, but a vinyl silane coupling agent, an amino silane coupling agent, an alkyl silane coupling agent, an epoxy silane coupling agent, a methacryloxy silane coupling agent, Examples include (poly) sulfide silane coupling agents and mercaptosilane silane coupling agents, and (poly) sulfide silane coupling agents and mercaptosilane silane coupling agents are particularly preferred. The mercaptosilane-based silane coupling agent may have a protected mercaptosilane structure protected with a carboxylic acid or the like. A polysulfide-based silane coupling agent represented by the general formula [I] is particularly preferable, and bis (3-triethoxysilylpropyl) disulfide (abbreviated as TESPD) and bis (3-triethoxysilylpropyl) tetrasulfide (abbreviated as TESPT) are preferable. Particularly preferred.
_{^{(R 16 -O) 3-Y}} R 16 -Si-R 17 -Sx-R 17 -Si-R 16 (O-R 16) 3-Y [I]
(In the formula, R ¹⁶ is a monovalent hydrocarbon group having 1 to 18 carbon atoms, R ¹⁷ is a divalent hydrocarbon group having 1 to 9 carbon atoms, x is 2 to 6, _Y is 0, 1, or 2) Is an integer.)

  Specific examples of other silane coupling agents used in combination include Cabras 2A, Cabras 2B, Cabras 4 manufactured by Daiso, Si-75, Si-69, Si-363 manufactured by Degussa, and A manufactured by Momentive. -1289, NXT, NXT-LowV, A-189, Shin-Etsu Chemical KBE-846, and the like, but are not limited thereto. Moreover, these can also be used individually or in mixture.

  The content when other silane coupling agents are used in combination is preferably 0.1 to 30 parts by weight, more preferably 1 to 20 parts by weight with respect to 100 parts by weight of rubber. When a silane coupling agent containing a group that reacts with a silica-based filler, a group having a nitrogen atom and a group that binds to a crosslinking agent is used in combination with another silane coupling agent, the total weight of the silane coupling agent is rubber. It is preferable not to exceed 30 parts by weight per 100 parts by weight.

  In the present invention, a silane coupling agent containing a group that reacts with a silica-based filler and a group that binds to a nitrogen atom and a crosslinking agent is dissolved in an aqueous solution or a mixture of water and an organic solvent miscible with water. It may be used as a solution. The organic solvent miscible with water is not particularly limited, but alcohols such as methanol, ethanol and isopropanol, ketones such as acetone, ethers such as tetrahydrofuran (THF) and dioxane, acetonitrile, and dimethyl sulfoxide (DMSO) Etc. In this case, the concentration of the silane coupling agent containing a group that reacts with the silica-based filler, a nitrogen atom, and a group that binds to the cross-linking agent is not particularly limited, but may be 5 wt% or more and 95 wt% or less. Good.

  In addition to the above, the rubber composition of the present invention can use compounding agents usually used in the rubber industry, unless departing from the spirit of the present invention. For example, guanidine crosslinking accelerators, sulfenamide crosslinking accelerators, crosslinking accelerators (auxiliaries) such as zinc white, processing aids such as stearic acid, anti-aging agents such as phenyl-α-naphthylamine, carbon black, carbonic acid Fillers such as calcium, reinforcing agents, softeners, plasticizers and the like can be used.

  For the production of the rubber composition of the present invention, kneading is preferably performed at 80 to 250 ° C, and more preferably 100 to 200 ° C. The kneading time is not particularly limited, but is, for example, 1 minute to 1 hour.

  The rubber composition of the present invention may further contain a crosslinking agent. Examples of the crosslinking agent used in the present invention include sulfur, selenium, organic peroxide, morpholine disulfide, thiuram compound, and oxime compound. Crosslinking agents are particularly preferred, but are not limited to these.

  The content of the crosslinking agent is preferably 0.1 to 20 parts by weight, more preferably 0.2 to 10 parts by weight, and more preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of rubber. It is particularly preferable to contain it.

  The kneading of the composition (crosslinking rubber composition) after adding the crosslinking agent to the rubber composition of the present invention is preferably carried out at 100 ° C. or lower. The kneading time is not particularly limited, but is, for example, 1 minute to 1 hour.

  The kneading of the rubber composition of the present invention and the rubber composition for crosslinking can be carried out using various mixing machines such as rolls, pressure kneaders, intermixers, and banbury mixers that are usually used in the rubber industry. It is suitable for the production of dynamically used rubber parts such as treads, anti-vibration rubbers, and shoe soles.

  The crosslinking rubber composition thus prepared is molded into an intended shape by an extruder, a calender roll, or a press, and is preferably heated at 130 to 230 ° C. for 1 minute to 3 hours to obtain a crosslinked product. In addition, a mold may be used for crosslinking.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. However, the present invention is not limited to the following examples without departing from the gist thereof.

Preparation of organosilicon compound 1 7.7 g of allyl chloride (manufactured by Wako Pure Chemical Industries, Ltd.) was added to 22.1 g of 3-aminopropyltriethoxysilane (JNC S330), and the mixture was stirred at room temperature for 3 hours at 500 rpm. This reaction solution was added to 200 g of hexane and stirred vigorously, and after filtering the white precipitate, the filtrate was concentrated to obtain an organosilicon compound slurry. This slurry was dissolved in ethanol, and this solution was analyzed by GC and GC-MS. As a result, (mono) allylaminopropyltriethoxysilane and diallylaminopropyltriethoxysilane were in a 44:56 mixture. As a result of analysis by chlorine content analysis (ion chromatography), the chlorine content was 2.7%, suggesting that some of these compounds exist as hydrochlorides.

Production of organosilicon compound 2 16.7 g of the organosilicon compound 1 obtained above and 6.6 g of triethylamine (manufactured by Wako Pure Chemical Industries, Ltd.) were mixed and stirred for 1 hour. This was added to 100 g of hexane and stirred vigorously. After filtering the white precipitate, the filtrate was concentrated to obtain an organosilicon compound 2. As a result of analysis by GC and GC-MS, (mono) allylaminopropyltriethoxysilane and diallylaminopropyltriethoxysilane were in a 43:57 mixture.

The GC measurement was carried out using a capillary column (GL Science TC-5 (30 m × 0.25 mm ID 0.25 μm)) and a GL Science GC353B equipped with an FID detector. The inlet and detector temperatures were 250 ° C., and nitrogen was used as the carrier gas. The column temperature rising condition was maintained at an initial temperature of 50 ° C. for 3 minutes, then heated to 200 ° C. at a rate of 10 ° C./minute, held at that temperature for 4 minutes, and then the measurement was completed. The retention times of (mono) allylaminopropyltriethoxysilane and diallylaminopropyltriethoxysilane at this time were 15.8 minutes and 17.5 minutes, respectively.
The GC-MS measurement is composed of Agilent Technologies 6890N equipped with a capillary column (GL Science TC-5 (30 m × 0.25 mm ID 0.25 μm)) and JEOL JMS-T100GC. The GC conditions were such that the inlet and detector temperatures were 250 ° C., and the carrier gas was helium. The column temperature rising condition was maintained at an initial temperature of 50 ° C. for 3 minutes, then heated to 200 ° C. at a rate of 10 ° C./minute, held at that temperature for 4 minutes, and then the measurement was completed. The interface temperature between the GC body and the MS was 260 ° C. The MS conditions were an ionization chamber temperature of 200 ° C., a standard material introduction part temperature of 70 ° C., a detector voltage of 1900 V, and measurement was performed by the EI method. At this time, the retention times of (mono) allylaminopropyltriethoxysilane and diallylaminopropyltriethoxysilane were 15.1 minutes and 16.5 minutes, respectively.
The chlorine content was measured by a suppressor type ion chromatography. Using a DX-500 manufactured by Dionex Corporation equipped with a guard column (IonPac AG4A-SC), a separation column (IonPac AS4A-SC), a suppressor (ASRS-300 (current value 50 mA)), and an electric conductivity detector, 1.5 mM Sodium carbonate / 1.5 mM aqueous sodium hydrogen carbonate solution was used as an eluent, and measurement was performed under the condition of 1.5 ml / min. The sample was dissolved in pure water, and the sample introduction amount at this time was 25 μl.

Production of Rubber Composition The compound shown in Table 1 (I) was kneaded with a 12-inch roll at 40 to 50 ° C. for 30 minutes based on a rubber content of 1000 g, and subdivided so that the weight of the rubber content was 200 g. . The subdivided compound was kneaded with a 6 inch roll at 100 ° C. for 2 minutes. Immediately after that, the coupling agent shown in the formulation (II) in Table 1 was added and kneaded for 6 minutes, and the sheet was taken out and cooled to room temperature. Next, a part of the compound containing only the blends (I) and (II) was taken for the workability test 1, and the remaining compound was weighed so as to be based on 180 g of rubber, and shown in the blend (III) of Table 1. After adding the indicated crosslinking agent component and kneading for 10 minutes, a sheet having a thickness of about 2 mm was obtained. A part of the compound including all of the blends (I) to (III) was collected for workability test 2, and the next day, the remaining compound was hot-press crosslinked at 160 ° C. for 20 minutes (30 compression test pieces were used). Samples for test were obtained.

Workability test 1
A compound containing no crosslinking agent (compounds containing only the blends (I) and (II)) was set in a vulcanization tester FDR manufactured by Ueshima Seisakusho, and the viscosity behavior at 180 ° C. for 10 minutes was measured.

Workability test 2
An uncrosslinked compound containing up to a crosslinking agent (compound containing all of the blends (I) to (III)) at 100 ° C. according to JIS K6300 using Mooney viscometer AM-3 manufactured by Toyo Seiki, L-type rotor Mooney viscosity (ML1 + 4) test was performed.

Tensile test A No. 3 dumbbell test piece was punched out from the crosslinked sheet, and a tensile test was conducted in accordance with JIS K6301 using Minebea Technograph TG-2kN.
Compression set test A test piece (large test piece described in JIS K6262) molded by hot pressing at 160 ° C for 30 minutes was carried out at 100 ° C for 72 hours in accordance with JIS K6262.

  The compounding agents used in Examples and Comparative Examples are shown below. In addition, since the coupling agent does not contain a sulfur content except for Comparative Example 1, the amount of sulfur added in Formulation (III) is adjusted in order to match the amount of sulfur in the total formulation.

＊１ ＪＳＲ社製 ＳＬ５５２
＊２ ＪＳＲ社製 ＢＲ０１
＊３ 東ソーシリカ製 Ｎｉｐｓｉｌ ＡＱ（ＢＥＴ比表面積 ２１５ｍ^２／ｇ）
＊４ 日本サンオイル社製 Ｓｕｎｔｈｅｎｅ４１５
＊５ ダイソー社製 ＣＡＢＲＵＳ−４
＊６ ＪＮＣ製 Ｓ３３０
＊７ 信越化学工業製 ＬＳ−２３００
＊８ 大内新興社製 ジフェニルグアニジン
＊９ 大内新興社製 Ｎ−シクロヘキシル−２−ベンジルスルフェンアミド

* 1 SL552 manufactured by JSR Corporation
* 2 BR01 made by JSR
* 3 Nippon Sil AQ (BET specific surface area 215 m ² / g) manufactured by Tosoh Silica
* 4 Suntine 415 made by Sun Oil Japan
* 5 CABRUS-4 manufactured by Daiso Corporation
* 6 J330 S330
* 7 Shin-Etsu Chemical LS-2300
* 8 Diphenylguanidine manufactured by Ouchi Shinsei Co., Ltd. * 9 N-cyclohexyl-2-benzylsulfenamide manufactured by Ouchi Shinsei Co., Ltd.

The test results of Examples and Comparative Examples obtained by the above test methods and blends are shown in Table 2 and FIG.

  As shown in FIG. 1, Examples 1 and 2 show a lower compound torque, indicating a lower viscosity during processing, such as with a compound Banbury mixer that does not contain a crosslinker. In addition, since Examples 1 and 2 have a small increase in torque, this means that the torque increase during kneading by a Banbury mixer or the like, that is, the risk of scorching during kneading is small.

  Further, as shown in Table 2, Examples 1 and 2 show smaller Mooney viscosities, indicating that the processability of the compound is improved. Moreover, since the modulus ratio is large and the compression set is also small, it is suggested that the reaction between silica and the coupling agent is further promoted.

  From the above results, it is shown that the silane coupling agent shown in this example has a low risk of scorching during kneading, low viscosity, and excellent coupling agent reaction efficiency.

  Since the rubber composition according to the present invention exhibits a low viscosity, it is possible to improve processability and high filler filling and to sufficiently exhibit the effect of the coupling agent, thereby simplifying the conventional kneading method. Therefore, it is suitable for the production of a member highly filled with silica, such as a tire tread and a sealing material. In addition, since the compression set is excellent, it is also suitable for producing anti-vibration rubber, O-rings, packings and the like.

Claims (13)

A rubber composition comprising a rubber, a silica-based filler, a silane coupling agent containing a group that reacts with the silica-based filler and a group represented by the general formula [1] .

(In the formula [1], R ¹ , R ² , R ³ , R ⁴ and R ⁵ in the repeating unit may independently be the same or different, and R ¹ and R ³ have 1 to 18 carbon atoms, An alkyl group-substituted or unsubstituted divalent alkyl group , R ² , R ⁴ and R ⁵ are groups bonded to a crosslinking agent selected from a vinyl group, an allyl group, an acryloyl group and a methacryloyl group ; Either an unsubstituted monovalent alkyl group or hydrogen, R ⁶ is a group bonded to a crosslinking agent selected from a vinyl group, an allyl group, an acryloyl group and a methacryloyl group, and an alkyl group substituted with 1 to 18 carbon atoms Or an unsubstituted monovalent alkyl group , hydrogen, and at least one of R ² , R ⁴ , R ⁵ , R ⁶ is a bridge selected from a vinyl group, an allyl group, an acryloyl group, and a methacryloyl group group bonded to agent . There repeating units p, q satisfies 1 ≦ p + q ≦ 6, each repeating unit may be a random .X ^- is a chloride ion). The rubber composition according to claim 1 , wherein the group bonded to the crosslinking agent is an allyl group . Groups that react with the silica filler, Si-O-C bond and / or Si-O-H is a group having a bond claim 1 or 2 rubber composition according to. The silane coupling agent containing a group that reacts with a silica-based filler and a group represented by the general formula [1] is a silane coupling represented by the general formula [2] and / or the general formula [3]. Item 4. The rubber composition according to any one of Items 1 to 3 .

(In the formula [2], A represents a group represented by the general formula [1], and R ⁷ , R ⁸ , and R ⁹ may be the same or different, and are substituted with 1 to 18 carbon atoms. Alternatively, an unsubstituted monovalent alkyl group, a monovalent alkoxy group having 1 to 18 carbon atoms, a hydroxy group, CnH _2n-1 O — ((CH ₂ ) _m O) _r , where n is 1 to 18, m Is one of polyalkylene glycol monoalkyl ether groups having 1 to 6 and r is 1 to 18, and at least one of R ⁷ , R ⁸ and R ^{9 is} an alkoxy group having 1 to 18 carbon atoms, a hydroxy group, CnH _{2n-1 O - ((CH} 2) m O) is represented by _r n is 1-18, m is 1 to 6, r is either polyalkylene glycol monoalkyl ether group is 1 to 18).

(In the formula [3], A represents a group represented by the general formula [1], and R ¹⁰ represents a monovalent alkoxy group having 1 to 18 carbon atoms, a hydroxy group, CnH _2n-1 O — ((CH ₂ ) _{m O)} is represented by _r n is 1 to 18, m is 1 to 6, r is either polyalkylene glycol monoalkyl ether group is ^{1~18, R 11,} R ¹² are either the same or different And a substituted or unsubstituted divalent alkyl group having 1 to 8 carbon atoms, W is —C (═O) —, —O—, —NR ¹³ —, —CR ¹⁴ R ¹⁵ —. R ¹³ , R ¹⁴ , and R ¹⁵ are each a substituted or unsubstituted monovalent alkyl group having 1 to 18 carbon atoms or hydrogen.) The silane coupling agent containing a silica-based filler and a group represented by the general formula [1] is used in a solution dissolved in water or a mixture of water and an organic solvent miscible with water. 4. The rubber composition according to any one of 4 to 4 . A wet silica of the silica-based filler is a BET specific surface area of 20 to 300 m ² / g, the rubber composition according to any one of claims 1 to 5 content is 5 to 200 parts by weight per 100 parts by weight of rubber . The content of the silane coupling agent containing a group reacting with a silica-based filler, a group having a nitrogen atom and a group binding to a crosslinking agent is 0.1 to 30 parts by weight with respect to 100 parts by weight of rubber. The rubber composition according to any one of 1 to 6 . Furthermore, vinyl silane coupling agents, amino silane coupling agents, alkyl silane coupling agents, epoxy silane coupling agents, methacryloxy silane coupling agents, (poly) sulfide silane coupling agents and mercapto silanes. The rubber composition according to any one of claims 1 to 7, comprising a silane coupling agent selected from silane coupling agents in combination of 0.1 to 30 parts by weight with respect to 100 parts by weight of rubber. The rubber composition according to any one of claims 1 to 8 , wherein the rubber is a diene rubber. The rubber composition according to any one of claims 1 to 9 , further comprising at least one selected from sulfur, selenium, organic peroxide, morpholine disulfide, thiuram compound, and oxime compound as a crosslinking agent. A crosslinked product obtained by crosslinking using the rubber composition according to claim 10 . A tire formed by crosslinking using the rubber composition according to claim 10 . Anti-vibration rubber obtained by crosslinking using the rubber composition according to claim 10 .

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