JP2004323564A - Rubber composition for vulcanization and vulcanized rubber material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber composition for vulcanization having improved heat resistance, its vulcanized rubber material, and an automotive part composed of the vulcanized rubber material which copes with the rise in temperature of an engine room particularly in the automotive use. <P>SOLUTION: The rubber composition for vulcanization comprises (a) an epihalohydrin rubber, (b) an oxetane compound such as a compound of formula (1) (wherein R<SP>1</SP>and R<SP>2</SP>are the same or different and each hydrogen, a hydroxy group, an alkyl group, an alkenyl group, an aromatic group, a halogen group, a substituted alkyl group, a substituted alkenyl group or a substituted aromatic group), (c) an acid acceptor, and (d) a vulcanizing agent. The vulcanized product can be obtained by vulcanizing the composition, and the automotive part is composed of the vulcanized product. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

（式中、Ｒ^１、Ｒ^２は同一または異なって、水素原子、水酸基、アルキル基、アルケニル基、芳香族基、ハロゲン基、置換アルキル基、置換アルケニル基あるいは置換芳香族基を表す。）
【００１３】
【化４】

（式中、Ｒ^３、Ｒ^４ は同一または異なって、水素原子、水酸基、アルキル基、アルケニル基、芳香族基、ハロゲン基、置換アルキル基、置換アルケニル基あるいは置換芳香族基を表し、Ｒ^５ は酸素原子、アルキレン基、芳香族基、置換アルキレン基あるいは置換芳香族基を表す。）
【００１４】
一般式（１）で表されるオキセタン化合物の具体的としては、３−エチル−３−ヒドロキメチルオキセタン、３−メチル−３−オキセタンメタノール、３−エチル−３−オキセタンメタノール、３−ブチル−３−オキセタンメタノール、３−メチル−３−オキセタンエタノール、３−エチル−３−オキセタンエタノール、３−ブチル−３−オキセタンエタノールなどオキセタン環および水酸基を有する化合物、３−メチル−３−アミノメチルオキセタン、３−エチル−３−アミノメチルオキセタンなどオキセタン環およびアミノ基を有する化合物、３−クロロメチル−３−メチルオキセタン、３−クロロメチル−３−エチルオキセタンなどのハロゲンを有する化合物、３−メチル−３−アリルオキシメチルオキセタン、３−エチル−３−アリルオキシメチルオキセタン、３−メチル−３−メタリルオキシメチルオキセタンなど脂肪族不飽和基を有する化合物、３−メチル−３−フェニルオキシメチルオキセタン、３−エチル−３−フェニルオキシメチルオキセタンなどの芳香族不飽和基を有する化合物が挙げられる。また、前記水酸基を有するオキセタン化合物と酢酸、プロピオン酸などのカルボン酸化合物とのエステル化物、前記アミノ基を有するオキセタン化合物とのアミド化物、前記ハロゲン基を有するオキセタン化合物と、メチルアルコール、エチルアルコール、エチレングリコール、ジエチレングリコール、グリセリンなどの水酸基含有化合物とのエーテル化物、前記水酸基を有するオキセタン化合物とジクロロメタン、１，１−ジブロモエタン、Ｐ−ジブロモベンゼンなどのハロゲン含有化合物とのエーテル化物などが挙げられる。
【００１５】
一般式（２）で表されるオキセタン骨格を複数有する多価オキセタン化合物の具体例としては、ジ［１−エチル（３−オキセタニル）］メチルエーテル、１，４−ビス［（３−エチル−３−オキセタニルメトキシ）メチル］ベンゼンなどが挙げられる。
【００１６】
本発明で用いられる、オキセタン化合物の配合量は、エピハロヒドリン系ゴム１００重量部に対して０．１〜１０重量部、好ましくは０．１〜５重量部、さらに好ましくは０．３〜３重量部である。この配合量がこの範囲未満であると耐熱改良効果が少なく、この範囲を越える加硫物の弾性率が低下する恐れがある。
【００１７】
本発明で用いられる受酸剤（ｃ）としては、加硫剤に応じて公知の受酸剤を使用できるが、好ましくは金属化合物および／または無機マイクロポーラス・クリスタルである。金属化合物としては、周期表第ＩＩ族（２族および１２族）金属の酸化物、水酸化物、炭酸塩、カルボン酸塩、ケイ酸塩、ホウ酸塩、亜リン酸塩、周期表第ＩＶ族（４族および１４族）金属の酸化物、塩基性炭酸塩、塩基性カルボン酸塩、塩基性亜リン酸塩、塩基性亜硫酸塩、三塩基性硫酸塩等の金属化合物が挙げられる。
【００１８】
前記金属化合物の具体例としては、マグネシア、水酸化マグネシウム、水酸化バリウム、炭酸マグネシウム、炭酸バリウム、生石灰、消石灰、炭酸カルシウム、ケイ酸カルシウム、ステアリン酸カルシウム、ステアリン酸亜鉛、フタル酸カルシウム、亜リン酸カルシウム、亜鉛華、酸化錫、リサージ、鉛丹、鉛白、二塩基性フタル酸鉛、二塩基性炭酸鉛、ステアリン酸錫、塩基性亜リン酸鉛、塩基性亜リン酸錫、塩基性亜硫酸鉛、三塩基性硫酸鉛等を挙げることができる。
【００１９】
好ましい受酸剤として、無機マイクロポーラス・クリスタルが挙げられる。無機マイクロポーラス・クリスタルとは、結晶性の多孔体を言い、無定型の多孔体、例えばシリカゲル、アルミナ等とは明瞭に区別できるものである。このような無機マイクロポーラス・クリスタルの例としては、ゼオライト類、アルミノホスフェート型モレキュラーシーブ、層状ケイ酸塩、合成ハイドロタルサイト、チタン酸アルカリ金属塩等が挙げられる。特に好ましい受酸剤としては、合成ハイドロタルサイトが挙げられる。
【００２０】
ゼオライト類は、天然ゼオライトの外、Ａ型、Ｘ型、Ｙ型の合成ゼオライト、ソーダライト類、天然ないしは合成モルデナイト、ＺＳＭ−５などの各種ゼオライトおよびこれらの金属置換体であり、これらは単独で用いても２種以上の組み合わせで用いても良い。また金属置換体の金属はナトリウムであることが多い。ゼオライト類としては酸受容能が大きいものが好ましく、Ａ型ゼオライトが好ましい。
【００２１】
合成ハイドロタルサイトは下記一般式（３）
Ｍｇ_ＸＺｎ_ＹＡｌ_Ｚ（ＯＨ）_{２（Ｘ＋Ｙ）＋３Ｚ−２}ＣＯ３・ｗＨ_２Ｏ （３）
［式中、ｘとｙ は０〜１０の実数、但しｘ＋ｙは１〜１０、ｚは１〜５の実数、ｗは０〜１０の実数をそれぞれ示す］で表わされる。一般式（５）で表されるハイドロタルサイト類の例として、
Ｍｇ_４．５ Ａｌ_２ （ＯＨ）_１３ＣＯ_３ ・３．５Ｈ_２ Ｏ
Ｍｇ_４．５ Ａｌ_２ （ＯＨ）_１３ＣＯ_３
Ｍｇ_４ Ａｌ_２ （ＯＨ）_１２ＣＯ_３ ・３．５Ｈ_２ Ｏ
Ｍｇ_６ Ａｌ_２ （ＯＨ）_１６ＣＯ_３ ・４Ｈ_２ Ｏ
Ｍｇ_５ Ａｌ_２ （ＯＨ）_１４ＣＯ_３ ・４Ｈ_２ Ｏ
Ｍｇ_３ Ａｌ_２ （ＯＨ）_１０ＣＯ_３ ・１．７Ｈ_２ Ｏ
Ｍｇ_３ ＺｎＡｌ_２ （ＯＨ）_１２ＣＯ_３ ・ｗＨ_２ Ｏ
Ｍｇ_３ ＺｎＡｌ_２ （ＯＨ）_１２ＣＯ_３
等を挙げることができる。
【００２２】
受酸剤の配合量は、エピハロヒドリン系ゴム１００重量部に対して０．２〜５０重量部、例えば０．５〜５０重量部、特に１〜２０重量部である。この範囲未満の配合量では架橋が不十分となり、一方この範囲を超えると加硫物が剛直になりすぎてエピハロヒドリン系ゴム加硫物として通常期待される物性が得られなくなる。
【００２３】
本発明で用いられる加硫剤（ｄ）としては、エピハロヒドリン系ゴムを架橋できるものであれば特に限定されないが、塩素原子の反応性を利用する公知の加硫剤、即ちポリアミン類、チオウレア類、チアジアゾール類、メルカプトトリアジン類、キノキサリン類等が、また、側鎖二重結合の反応性を利用する公知の加硫剤、例えば、有機過酸化物、硫黄、モルホリンポリスルフィド類、チウラムポリスルフィド類等が適宜使用される。
【００２４】
加硫剤を例示すれば、ポリアミン類としては、エチレンジアミン、ヘキサメチレンジアミン、ジエチレントリアミン、トリエチレンテトラミン、ヘキサメチレンテトラミン、ｐ−フェニレンジアミン、クメンジアミン、Ｎ，Ｎ’−ジシンナミリデン−１，６−ヘキサンジアミン、エチレンジアミンカーバメート、ヘキサメチレンジアミンカーバメート等が挙げられ、チオウレア類としては、２−メルカプトイミダゾリン、１，３−ジエチルチオウレア、１，３−ジブチルチオウレア、トリメチルチオウレア等が挙げられ、チアジアゾール類としては、２，５−ジメルカプト−１，３，４−チアジアゾール、２−メルカプト−１，３，４−チアジアゾール−５−チオベンゾエート等が挙げられ、メルカプトトリアジン類としては、２，４，６−トリメルカプト−１，３，５−トリアジン、１−ヘキシルアミノ−３，５−ジメルカプトトリアジン、１−ジエチルアミノ−３，５−ジメルカプトトリアジン、１−シクロヘキシルアミノ−３，５−ジメルカプトトリアジン、１−ジブチルアミノ−３，５−ジメルカプトトリアジン、２−アニリノ−４，６−ジメルカプトトリアジン、１−フェニルアミノ−３，５−ジメルカプトトリアジン等が挙げられ、キノキサリン類としては、２，３−ジメルカプトキノキサリン、キノキサリン−２，３−ジチオカーボネート、６−メチルキノキサリン−２，３−ジチオカーボネート、５，８−ジメチルキノキサリン−２，３−ジチカーボネート等が挙げられ、有機過酸化物としては、ｔｅｒｔ−ブチルヒドロパーオキサイド、ｐ−メンタンヒドロパーオキサイド、ジクミルパーオキサイド、ｔｅｒｔ−ブチルパーオキサイド、１，３−ビス（ｔｅｒｔ−ブチルパーオキシイソプロピル）ベンゼン、２，５−ジメチル−２，５−ジ（ｔｅｒｔ−ブチルパーオキシ）ヘキサン、ベンゾイルパーオキサイド、ｔｅｒｔ−ブチルパーオキシベンゾエート等が挙げられ、モルホリンポリスルフィド類としては、モルホリンジスルフィドが挙げられ、チウラムポリスルフィド類としては、テトラメチルチウラムジスルフィド、テトラエチルチウラムジスルフィド、テトラブチルチウラムジスルフィド、ジペンタメチレンチウラムテトラスルフィド、ジペンタメチレンチウラムヘキサスルフィド等が挙げられる。
【００２５】
加硫剤の配合量は、エピハロヒドリン系ゴム１００重量部に対して０．１〜１０重量部、好ましくは０．３〜５重量部である。この範囲未満の配合量では架橋が不十分となり、一方この範囲を超えると加硫物が剛直になりすぎてエピハロヒドリン系ゴム加硫物として通常期待される物性が得られなくなる。特に好ましい加硫剤としては、２−メルカプトイミダゾリンや６−メチルキノキサリン−２，３−ジチオカーボネートなどが挙げられる。加硫剤は一種を単独で用いても、二種以上を組み合わせて用いても良い。
【００２６】
また、通常これらの加硫剤と共に用いられる公知の促進剤（即ち、加硫促進剤）、遅延剤等を本発明の加硫用ゴム組成物にもそのまま用いることができる。これらの加硫促進剤の例としては、硫黄、チウラムスフィド類、モルホリンスルフィド類、アミン類、アミンの弱酸塩類、塩基性シリカ、四級アンモニウム塩類、四級ホスホニウム塩類、多官能ビニル化合物、メルカプトベンゾチアゾール類、スルフェンアミド類、ジメチオカーバメート類等を挙げることができる。遅延剤としてはＮ−シクロヘキサンチオフタルイミド、有機亜鉛化合物、酸性シリカ等を挙げることができる。特に好ましい促進剤として１， ８−ジアザビシクロ（５， ４， ０）ウンデセン−７（以下ＤＢＵと略）塩、１， ５−ジアザビシクロ（４， ３， ０）ノネン−５（以下ＤＢＮと略）塩およびホワイトカーボンが挙げられる。 ＤＢＵ塩としては、ＤＢＵ−炭酸塩、ＤＢＵ−ステアリン酸塩、ＤＢＵ−２−エチルヘキシル酸塩、ＤＢＵ−安息香酸塩、ＤＢＵ−サリチル酸塩、ＤＢＵ−３−ヒドロキシ−２−ナフトエ酸塩、ＤＢＵ−フェノール樹脂塩、ＤＢＵ−２−メルカプトベンゾチアゾール塩、ＤＢＵ−２−メルカプトベンズイミダゾール塩等であり、ＤＢＮ塩としては、ＤＢＮ−炭酸塩、ＤＢＮ−ステアリン酸塩、ＤＢＮ−２−エチルヘキシル酸塩、ＤＢＮ−安息香酸塩、ＤＢＮ−サリチル酸塩、ＤＢＮ−３−ヒドロキシ−２−ナフトエ酸塩、ＤＢＮ−フェノール樹脂塩、ＤＢＮ−２−メルカプトベンゾチアゾール塩、ＤＢＮ−２−メルカプトベンズイミダゾール塩等が挙げられる。促進剤または遅延剤の配合量は、エピハロヒドリン系ゴム１００重量部に対して０〜１０重量部、例えば０．１〜５重量部である。
【００２７】
本発明の加硫用ゴム組成物には、本発明の効果を損なわない限り、上記以外の配合剤、例えば、滑剤、老化防止剤、酸化防止剤、充填剤、補強剤、可塑剤、加工助剤、難燃剤、発泡助剤、導電剤、帯電防止剤等を任意に配合できる。さらに本発明の特性が失われない範囲で、当該技術分野で通常行われている、ゴム、樹脂等のブレンドを行うことも可能である。
【００２８】
本発明による加硫用ゴム組成物を製造するには、従来ポリマー加工の分野において用いられている任意の混合手段、例えばミキシングロール、バンバリーミキサー、各種ニーダー類等を用いることができる。本発明の加硫ゴム材料は、本発明の加硫用ゴム組成物を通常１００〜２００℃に加熱することで得られる。加硫時間は温度により異なるが、通常０．５〜３００分の間である。加硫成型の方法としては、金型による圧縮成型、射出成型、スチーム缶、エアーバス、赤外線或いはマイクロウェーブによる加熱等任意の方法を用いることができる。
【００２９】
本発明の加硫物は、通常エピハロヒドリン系ゴムが使用される分野に広く応用することができる。例えば、自動車用途などの各種燃料系積層ホース、エアー系積層ホース、チューブ、ベルト、ダイヤフラム、シール類等ゴム材料や、一般産業用機器・装置等のゴム材料として有用である。
【００３０】
以下、本発明を実施例、比較例により具体的に説明する。但し、本発明はその要旨を逸脱しない限り以下の実施例に限定されるものではない。
【００３１】
［実施例］
実施例１〜３、比較例１、２
下記表１に示す各材料をニーダーおよびオープンロールで混練し、未加硫ゴムシートを作製した。得られた未加硫ゴムシートを用い、ＪＩＳ Ｋ６３００に定めるムーニースコーチ試験を行った。また同じく得られた未加硫ゴムシートを１７０℃で１５分プレス加硫し、２ｍｍ厚の一次加硫物を得た。さらにこれをエア・オーブンで１５０℃で２時間加熱し、二次加硫物を得た。得られた二次加硫物を用い、引張試験（初期物性）および耐熱性の評価を行った。各評価試験はそれぞれＪＩＳ Ｋ ６２５１、ＪＩＳ Ｋ ６２５７に記載の方法に準じて行った。
【００３２】
圧縮永久歪試験は次のように行った。得られた上記未加硫ゴムシートを試験片作製用金型を用いて１７０℃で２０分プレス加硫し、直径約２９ｍｍ、高さ約１２．５ｍｍの円柱状試験片一次加硫物を得た。さらにこれをエア・オーブンで１５０℃で２時間加熱することにより二次加硫物を得た。同二次加硫物を用い、ＪＩＳ Ｋ ６２６２記載の方法に準じて試験を行った。
【００３３】
各試験方法より得られた実施例および比較例の試験結果を表２に示す。各表中、Ｖｍは最低粘度、ｔ５はＪＩＳ Ｋ６３００のムーニースコーチ試験に定めるムーニースコーチ時間、Ｍ_１００はＪＩＳ Ｋ６２５１の引張試験試験に定める１００％伸び時の引張応力、Ｍ_３００はＪＩＳ Ｋ６２５１の引張試験に定める３００％伸び時の引張応力、ＴｂはＪＩＳ Ｋ６２５１の引張試験試験に定める引張強さ、ＥｂはＪＩＳ Ｋ６２５１の引張試験試験に定める伸び、ＨｓはＪＩＳ Ｋ６２５３の硬さ試験に定める硬さをそれぞれ意味する。
【００３４】
【表１】

【００３５】
【表２】

【００３６】
【表３】

【００３７】
【表４】

【００３８】
本発明において、耐熱性が良好であるとは、耐熱試験後の引張強さＴｂが大きいことを言う。 以上の表１〜４より、オキセタン化合物を含有する各実施例で、オキセタン化合物を含有しない比較例に比べて、耐熱性が改良されていることが判る。
【００３９】
【発明の効果】
本発明により、エピハロヒドリン系ゴムにおいて耐熱性の改良された加硫用ゴム組成物およびその加硫ゴム材料を提供することができる。[0001]
[Field of the Invention]
The present invention relates to a vulcanizing rubber composition based on an epihalohydrin rubber having improved heat resistance and a vulcanized rubber material obtained by vulcanizing the composition.
[0002]
[Prior art]
Epihalohydrin rubber materials are widely used as fuel hoses, air hoses, and tube materials in automotive applications by utilizing their heat resistance, oil resistance, ozone resistance, and the like. However, with the recent implementation of emission control measures and energy-saving measures, higher engine performance and compactness, etc., a rise in the temperature in the engine room and maintenance-free automobile parts, demands for improving the heat resistance of rubber materials have been increasing year by year. It's getting tougher.
[0003]
Conventionally, as a means for improving the heat resistance of an epihalohydrin rubber, a method using a 1,3-dithiol compound as a vulcanizing agent (see, for example, JP-A-2002-80640) or an amorphous form of a specific metal as an acid acceptor is used. A method using a silicate (for example, see JP-A-2002-249621) has been proposed, but further improvement is required.
[0004]
On the other hand, common vulcanizing agents for vulcanizing epihalohydrin rubbers include thioureas, mercaptotriazines, quinoxalines and the like, which are required for the storage stability, mechanical properties, compression properties of rubber materials. It is appropriately selected according to characteristics such as permanent distortion, ozone resistance, cold resistance, and oil resistance, a method of processing a rubber material, and economic efficiency of a vulcanizing agent. As the acid acceptor, magnesium oxide, a lead compound, zinc oxide, synthetic hydrotalcite, slaked lime, quick lime, and the like are appropriately selected according to the vulcanizing agent used.
[0005]
[Patent Document 1] JP-A-2002-80640 [Patent Document 2] JP-A-2002-249621
[Problems to be solved by the invention]
Therefore, when the heat resistance of the epihalohydrin rubber is improved by a method using the specific vulcanizing agent or a method using a specific acid acceptor, the processing method of the rubber material is limited, or the rubber material is used. There is a concern that other required characteristics, which are different from each other, cannot be sufficiently satisfied depending on the parts to be manufactured. An object of the present invention is to provide a method for improving the heat resistance of an epihalohydrin rubber regardless of the type of vulcanizing agent or acid acceptor used for the epihalohydrin rubber in view of the above circumstances.
[0007]
[Means for Solving the Problems]
The present inventors have conducted various studies in order to solve the above-mentioned problems, and found that, by further adding an oxetane compound to a vulcanizing rubber composition containing an epihalohydrin-based rubber, a vulcanizing agent, and an acid acceptor, heat resistance was improved. The inventors have found that the properties are further improved, and have completed the present invention.
[0008]
That is, the present invention provides a vulcanizing rubber composition containing (a) an epihalohydrin rubber, (b) an oxetane compound, (c) an acid acceptor, and (d) a vulcanizing agent, and vulcanizing the composition. The present invention relates to a vulcanized rubber material and an automotive rubber part made of the vulcanized rubber material.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
In the composition of the present invention, the epihalohydrin rubber (a) refers to an epihalohydrin homopolymer or a copolymer with another epoxide copolymerizable with epihalohydrin, for example, ethylene oxide, propylene oxide, allyl glycidyl ether and the like. Examples thereof include epichlorohydrin homopolymer, epibromohydrin homopolymer, epichlorohydrin-ethylene oxide copolymer, epibromohydrin-ethylene oxide copolymer, epichlorohydrin-propylene oxide copolymer, epibromohydrin -Propylene oxide copolymer, epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer, epibromohydrin-ethylene oxide-allyl glycidyl ether terpolymer, epichlorohydrin-ethylene oxide-propylene oxide-allyl glycidyl ether 4 And quaternary copolymers such as terpolymers, epibromohydrin-ethylene oxide-propylene oxide-allyl glycidyl ether quaternary copolymers, and the like. . Preferably epichlorohydrin homopolymer, epichlorohydrin-ethylene oxide copolymer, epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer, more preferably epichlorohydrin-ethylene oxide copolymer, epichlorohydrin-ethylene oxide-allyl glycidyl ether It is a terpolymer.
[0010]
In the case of copolymers, the copolymerization ratio thereof is, for example, epichlorohydrin 5 mol to 95 mol%, preferably 10 mol% to 75 mol%, more preferably 10 to 65 mol%, and ethylene oxide 5 mol% to 95 mol%, preferably 25 mol% to 90 mol. %, More preferably 35 mol% to 90 mol%, allyl glycidyl ether 0 mol% to 10 mol%, preferably 1 mol% to 8 mol%, more preferably 1 mol% to 7 mol%. Although the molecular weight of these homopolymers or copolymers is not particularly limited, it is usually about ML _{1 + 4} (100 ° C.) = 30 to 150 in terms of Mooney viscosity.
[0011]
Further, as the oxetane compound of the present invention, any compound having one or more oxetane skeletons in the molecule can be used, and a polyvalent oxetane compound having a plurality of oxetane skeletons may be used.
An oxetane compound represented by the following general formula (1) or (2) is a preferred example.
[0012]
Embedded image

(In the formula, R ¹ and R ² are the same or different and represent a hydrogen atom, a hydroxyl group, an alkyl group, an alkenyl group, an aromatic group, a halogen group, a substituted alkyl group, a substituted alkenyl group or a substituted aromatic group.)
[0013]
Embedded image

(Wherein, R ^3, R ⁴ are the same or different and each represents a hydrogen atom, a hydroxyl group, an alkyl group, an alkenyl group, an aromatic group, a halogen group, a substituted alkyl group, a substituted alkenyl group or substituted aromatic group, R ⁵ Represents an oxygen atom, an alkylene group, an aromatic group, a substituted alkylene group or a substituted aromatic group.)
[0014]
Specific examples of the oxetane compound represented by the general formula (1) include 3-ethyl-3-hydroxymethyloxetane, 3-methyl-3-oxetanemethanol, 3-ethyl-3-oxetanemethanol, and 3-butyl-3. Compounds having an oxetane ring and a hydroxyl group, such as -oxetanemethanol, 3-methyl-3-oxetaneethanol, 3-ethyl-3-oxetaneethanol, 3-butyl-3-oxetaneethanol, 3-methyl-3-aminomethyloxetane, 3 Compounds having an oxetane ring and an amino group such as -ethyl-3-aminomethyloxetane; compounds having a halogen such as 3-chloromethyl-3-methyloxetane and 3-chloromethyl-3-ethyloxetane; 3-methyl-3- Allyloxymethyl oxetane, 3-ethyl-3-ali Compounds having an aliphatic unsaturated group such as oxymethyloxetane and 3-methyl-3-methallyloxymethyloxetane, and aromatic compounds such as 3-methyl-3-phenyloxymethyloxetane and 3-ethyl-3-phenyloxymethyloxetane Examples include compounds having an unsaturated group. Further, an esterified product of the oxetane compound having a hydroxyl group and acetic acid, a carboxylic acid compound such as propionic acid, an amidated product of the oxetane compound having the amino group, an oxetane compound having the halogen group, methyl alcohol, ethyl alcohol, Examples thereof include etherified products of a hydroxyl group-containing compound such as ethylene glycol, diethylene glycol, and glycerin, and etherified products of the oxetane compound having a hydroxyl group and a halogen-containing compound such as dichloromethane, 1,1-dibromoethane, and P-dibromobenzene.
[0015]
Specific examples of the polyvalent oxetane compound having a plurality of oxetane skeletons represented by the general formula (2) include di [1-ethyl (3-oxetanyl)] methyl ether and 1,4-bis [(3-ethyl-3 -Oxetanylmethoxy) methyl] benzene and the like.
[0016]
The amount of the oxetane compound used in the present invention is 0.1 to 10 parts by weight, preferably 0.1 to 5 parts by weight, more preferably 0.3 to 3 parts by weight, based on 100 parts by weight of the epihalohydrin rubber. It is. If the amount is less than this range, the effect of improving heat resistance is small, and the elastic modulus of the vulcanizate exceeding this range may be reduced.
[0017]
As the acid acceptor (c) used in the present invention, a known acid acceptor can be used depending on the vulcanizing agent, and is preferably a metal compound and / or an inorganic microporous crystal. Examples of the metal compound include oxides, hydroxides, carbonates, carboxylates, silicates, borates, and phosphites of Group II (Groups 2 and 12) metals of the periodic table, and those of the periodic table IV. Group (Group 4 and Group 14) metal oxides, basic carbonates, basic carboxylate salts, basic phosphites, basic sulfites, tribasic sulfates, and other metal compounds.
[0018]
Specific examples of the metal compound include magnesia, magnesium hydroxide, barium hydroxide, magnesium carbonate, barium carbonate, quicklime, slaked lime, calcium carbonate, calcium silicate, calcium stearate, zinc stearate, calcium phthalate, calcium phosphite, Zinc white, tin oxide, litharge, lead red, lead white, dibasic lead phthalate, dibasic lead carbonate, tin stearate, basic lead phosphite, basic tin phosphite, basic lead sulfite, Examples include tribasic lead sulfate.
[0019]
Preferred acid acceptors include inorganic microporous crystals. The inorganic microporous crystal refers to a crystalline porous body, which can be clearly distinguished from an amorphous porous body such as silica gel and alumina. Examples of such inorganic microporous crystals include zeolites, aluminophosphate-type molecular sieves, layered silicates, synthetic hydrotalcite, alkali metal titanates, and the like. Particularly preferred acid acceptors include synthetic hydrotalcite.
[0020]
Zeolites are, in addition to natural zeolites, various zeolites such as A-type, X-type, and Y-type synthetic zeolites, sodalites, natural or synthetic mordenites, ZSM-5 and the like, and metal substitutes thereof. They may be used or two or more kinds may be used in combination. The metal of the metal substitute is often sodium. As the zeolites, those having a large acid acceptability are preferable, and A-type zeolites are preferable.
[0021]
Synthetic hydrotalcite has the following general formula (3)
_{Mg X Zn Y Al Z (OH} ) 2 (X + Y) + 3Z-2 CO3 · wH 2 O (3)
[Where x and y are real numbers from 0 to 10, where x + y is a real number from 1 to 10, z is a real number from 1 to 5, and w is a real number from 0 to 10]. Examples of hydrotalcites represented by the general formula (5) include:
_{Mg 4.5 Al 2 (OH) 13} CO 3 · 3.5H 2 O
Mg _4.5 Al ₂ (OH) ₁₃ CO _{3
Mg 4 Al 2 (OH) 12} CO 3 · 3.5H 2 O
_{Mg 6 Al 2 (OH) 16} CO 3 · 4H 2 O
_{Mg 5 Al 2 (OH) 14} CO 3 · 4H 2 O
_{Mg 3 Al 2 (OH) 10} CO 3 · 1.7H 2 O
Mg ₃ ZnAl ₂ (OH) ₁₂ CO ₃ .wH ₂ O
Mg ₃ ZnAl ₂ (OH) ₁₂ CO ₃
And the like.
[0022]
The compounding amount of the acid acceptor is 0.2 to 50 parts by weight, for example, 0.5 to 50 parts by weight, particularly 1 to 20 parts by weight based on 100 parts by weight of the epihalohydrin rubber. If the compounding amount is less than this range, crosslinking will be insufficient, while if it exceeds this range, the vulcanizate will be too rigid and the properties normally expected as an epihalohydrin rubber vulcanizate will not be obtained.
[0023]
The vulcanizing agent (d) used in the present invention is not particularly limited as long as it can crosslink the epihalohydrin-based rubber, but known vulcanizing agents utilizing the reactivity of chlorine atoms, that is, polyamines, thioureas, Thiadiazoles, mercaptotriazines, quinoxalines and the like, and also known vulcanizing agents utilizing the reactivity of side chain double bonds, for example, organic peroxides, sulfur, morpholine polysulfides, thiuram polysulfides and the like are suitable. used.
[0024]
Examples of the vulcanizing agent include polyamines such as ethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, hexamethylenetetramine, p-phenylenediamine, cumenediamine, N, N'-dicinnamylidene-1,6-hexanediamine. Thioureas include 2-mercaptoimidazoline, 1,3-diethylthiourea, 1,3-dibutylthiourea, trimethylthiourea, and the like, and thiadiazoles include 2 , 5-dimercapto-1,3,4-thiadiazole, 2-mercapto-1,3,4-thiadiazole-5-thiobenzoate, and the like. Rimercapto-1,3,5-triazine, 1-hexylamino-3,5-dimercaptotriazine, 1-diethylamino-3,5-dimercaptotriazine, 1-cyclohexylamino-3,5-dimercaptotriazine, 1 -Dibutylamino-3,5-dimercaptotriazine, 2-anilino-4,6-dimercaptotriazine, 1-phenylamino-3,5-dimercaptotriazine, and the like, and quinoxalines include 2,3- Dimercaptoquinoxaline, quinoxaline-2,3-dithiocarbonate, 6-methylquinoxaline-2,3-dithiocarbonate, 5,8-dimethylquinoxaline-2,3-dithiocarbonate, and the like. tert-butyl hydroperoxide, p-menthane hydroperoxide Side, dicumyl peroxide, tert-butyl peroxide, 1,3-bis (tert-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, benzoylper Oxide, tert-butyl peroxybenzoate, etc .; morpholine polysulfides include morpholine disulfide; thiuram polysulfides include tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, dipentamethylenethiuram tetra Sulfide, dipentamethylenethiuram hexasulfide and the like.
[0025]
The amount of the vulcanizing agent is 0.1 to 10 parts by weight, preferably 0.3 to 5 parts by weight, based on 100 parts by weight of the epihalohydrin rubber. If the compounding amount is less than this range, crosslinking will be insufficient, while if it exceeds this range, the vulcanizate will be too rigid and the properties normally expected as an epihalohydrin rubber vulcanizate will not be obtained. Particularly preferred vulcanizing agents include 2-mercaptoimidazoline and 6-methylquinoxaline-2,3-dithiocarbonate. The vulcanizing agent may be used alone or in combination of two or more.
[0026]
Known accelerators (i.e., vulcanization accelerators), retarders and the like usually used together with these vulcanizing agents can be used as they are in the vulcanizing rubber composition of the present invention. Examples of these vulcanization accelerators include sulfur, thiuram sulfides, morpholine sulfides, amines, amine weak acid salts, basic silica, quaternary ammonium salts, quaternary phosphonium salts, polyfunctional vinyl compounds, mercapto Benzothiazoles, sulfenamides, dimethiocarbamates and the like can be mentioned. Examples of the retarder include N-cyclohexanethiophthalimide, an organic zinc compound, and acidic silica. As particularly preferred accelerators, 1,8-diazabicyclo (5,4,0) undecene-7 (hereinafter abbreviated as DBU) salt and 1,5-diazabicyclo (4,3,0) nonene-5 (hereinafter abbreviated as DBN) salt And white carbon. Examples of the DBU salt include DBU-carbonate, DBU-stearate, DBU-2-ethylhexylate, DBU-benzoate, DBU-salicylate, DBU-3-hydroxy-2-naphthoate, DBU-phenol. Resin salts, DBU-2-mercaptobenzothiazole salts, DBU-2-mercaptobenzimidazole salts, and the like. Examples of DBN salts include DBN-carbonate, DBN-stearate, DBN-2-ethylhexylate, and DBN-. Benzoate, DBN-salicylate, DBN-3-hydroxy-2-naphthoate, DBN-phenol resin salt, DBN-2-mercaptobenzothiazole salt, DBN-2-mercaptobenzimidazole salt and the like. The compounding amount of the accelerator or the retarder is 0 to 10 parts by weight, for example, 0.1 to 5 parts by weight based on 100 parts by weight of the epihalohydrin rubber.
[0027]
In the vulcanizing rubber composition of the present invention, compounding agents other than those described above, for example, a lubricant, an antioxidant, an antioxidant, a filler, a reinforcing agent, a plasticizer, a processing aid, as long as the effects of the present invention are not impaired. Agents, flame retardants, foaming aids, conductive agents, antistatic agents, and the like can be arbitrarily compounded. Further, a blend of a rubber, a resin, and the like, which is generally performed in the technical field, can be performed as long as the characteristics of the present invention are not lost.
[0028]
In order to produce the rubber composition for vulcanization according to the present invention, any mixing means conventionally used in the field of polymer processing, for example, a mixing roll, a Banbury mixer, various kneaders and the like can be used. The vulcanized rubber material of the present invention is obtained by heating the rubber composition for vulcanization of the present invention usually to 100 to 200 ° C. The vulcanization time depends on the temperature, but is usually between 0.5 and 300 minutes. As a method of vulcanization molding, any method such as compression molding by a mold, injection molding, steam can, air bath, heating by infrared rays or microwaves can be used.
[0029]
The vulcanizates of the present invention can be widely applied to fields where epihalohydrin rubbers are usually used. For example, it is useful as a rubber material for various fuel-based laminated hoses, air-based laminated hoses, tubes, belts, diaphragms, seals, and the like for automobiles and rubber materials for general industrial equipment and devices.
[0030]
Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples. However, the present invention is not limited to the following embodiments unless departing from the gist thereof.
[0031]
[Example]
Examples 1 to 3, Comparative Examples 1 and 2
Each material shown in the following Table 1 was kneaded with a kneader and an open roll to produce an unvulcanized rubber sheet. The Mooney scorch test specified in JIS K6300 was performed using the obtained unvulcanized rubber sheet. The unvulcanized rubber sheet obtained was press-vulcanized at 170 ° C. for 15 minutes to obtain a primary vulcanized product having a thickness of 2 mm. This was further heated at 150 ° C. for 2 hours in an air oven to obtain a secondary vulcanizate. Using the obtained secondary vulcanizate, a tensile test (initial physical properties) and heat resistance were evaluated. Each evaluation test was performed according to the method described in JIS K6251 and JIS K6257, respectively.
[0032]
The compression set test was performed as follows. The obtained unvulcanized rubber sheet was press-vulcanized at 170 ° C. for 20 minutes using a mold for preparing a test piece to obtain a primary vulcanized product of a cylindrical test piece having a diameter of about 29 mm and a height of about 12.5 mm. Was. This was further heated at 150 ° C. for 2 hours in an air oven to obtain a secondary vulcanizate. Using the same secondary vulcanizate, a test was conducted according to the method described in JIS K6262.
[0033]
Table 2 shows the test results of Examples and Comparative Examples obtained by each test method. In each table, Vm minimum viscosity, t5 Mooney scorch time specified in Mooney scorch test JIS _{K6300, M 100} is a tensile _{stress, M 300} at 100% elongation stipulated in tensile test test JIS K6251 tensile of JIS K6251 test The tensile stress at 300% elongation specified in, Tb is the tensile strength specified in the tensile test of JIS K6251, Eb is the elongation specified in the tensile test of JIS K6251, and Hs is the hardness specified in the hardness test of JIS K6253. means.
[0034]
[Table 1]

[0035]
[Table 2]

[0036]
[Table 3]

[0037]
[Table 4]

[0038]
In the present invention, “good heat resistance” means that the tensile strength Tb after the heat test is large. From the above Tables 1 to 4, it can be seen that in each of the examples containing the oxetane compound, the heat resistance was improved as compared with the comparative examples not containing the oxetane compound.
[0039]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the rubber composition for vulcanization which improved the heat resistance in epihalohydrin type rubber and its vulcanized rubber material can be provided.

Claims (8)

A vulcanizing rubber composition comprising (a) an epihalohydrin-based rubber, (b) an oxetane compound, (c) an acid acceptor, and (d) a vulcanizing agent. The vulcanizing rubber composition according to claim 1, wherein (b) the okitacene compound is a compound represented by the following general formula (1) or (2).

(In the formula, R ¹ and R ² are the same or different and represent a hydrogen atom, a hydroxyl group, an alkyl group, an alkenyl group, an aromatic group, a halogen group, a substituted alkyl group, a substituted alkenyl group or a substituted aromatic group.)

(Wherein, R ^3, R ⁴ are the same or different and each represents a hydrogen atom, a hydroxyl group, an alkyl group, an alkenyl group, an aromatic group, a halogen group, a substituted alkyl group, a substituted alkenyl group or substituted aromatic group, R ⁵ Represents an oxygen atom, an alkylene group, an aromatic group, a substituted alkylene group or a substituted aromatic group.) The vulcanizing rubber composition according to claim 1 or 2, wherein the acid acceptor is a metal compound and / or an inorganic microporous crystal. The vulcanizing rubber composition according to any one of claims 1 to 3, wherein the acid acceptor is synthetic hydrotalcite. 5. The vulcanizing rubber composition according to claim 1, wherein the vulcanizing agent is a quinoxaline. 5. The vulcanizing rubber composition according to claim 1, wherein the vulcanizing agent is a thiourea. A vulcanized rubber material obtained by vulcanizing the vulcanized rubber composition according to claim 1. An automotive component comprising the vulcanized rubber material according to claim 7.