JP4154800B2 - Blend rubber vulcanizing composition - Google Patents

Description

［式中、Ｒ¹はメルカプト基、アルコキシ基、アルキルアミノ基、ジアルキルアミノ基、シクロアルキルアミノ基、ジシクロアルキルアミノ基、アリールアミノ基からなる群から選ばれる基である。］
で表されるメルカプトトリアジン化合物であってよい。
【００１５】
メルカプトトリアジン化合物としては、２,４,６−トリメルカプト−１,３,５−トリアジン、１−メトキシ−３,５−ジメルカプトトリアジン、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る。
特に２,４,６−トリメルカプト−１,３,５−トリアジンが好ましい。
【００１６】
ポリチオール系化合物又はその誘導体は、メルカプト基を有するキノキサリン誘導体、例えば２，３−ジメルカプトキノキサリンまたはその誘導体であってよい。
【００１７】
２，３−ジメルカプトキノキサリンまたはその誘導体は下記一般式（ＩＩ）または（ＩＩ’）で表される化合物である。
【化４】

［式中、Ｒ²、Ｒ³、Ｒ⁴及びＲ⁵は夫々同一でも異なっていても良く、水素又はアルキル基から選ばれる炭素数１〜８の基である。
Ａ¹、Ａ²は同一でも異なっていてもよく、水素、アルカリ金属、−Ｎ（Ａ³）Ａ⁴、−Ｃ（＝Ｏ）Ａ⁵から選ばれる基である。
（Ａ³、Ａ⁴は同一でも異なっていてもよく、水素又はアルキル基、シクロアルキル基、アリール基、アラルキル基から選ばれる炭素数１〜１２の基であり、Ａ³とＡ⁴が互いに結合して炭化水素環を形成していてもよく、又ヘテロ原子を介して結合し複素環を形成していてもよい。
Ａ⁵はアルキル基、シクロアルキル基、アルケニル基、アリール基、アラルキル基から選ばれる炭素数１〜１８の基、もしくは−Ａ⁶−ＣＯＯＨの構造をなし、Ａ⁶がアルキレン基、アルケニレン基から選ばれる炭素数１〜８の基又はシクロアルキレン基、アリーレン基、アラルキレン基から選ばれる炭素数６〜１２の基であるか、又は、−Ａ⁶−Ｃ（＝Ｏ）−の構造をなして同一分子内あるいは別の２，３−ジメルカプトキノキサリンまたはその誘導体のチオール基とエステル結合をなしていてもよい。）］
【００１８】
上記Ｒ²、Ｒ³、Ｒ⁴、Ｒ⁵を形成するアルキル基としては、例えばメチル基、エチル基、イソプロピル基、ｎ−ブチル基、イソブチル基、ｎ−ヘキシル基等を挙げることができる。
又Ａ¹、Ａ²としては、例えばアミノ基、エチルアミノ基、ジエチルアミノ基、ジオクチルアミノ基、シクロヘキシルアミノ基、ジシクロヘキシルアミノ基、アニリノ基、モノベンジルアミノ基、ビペリジノ基、ピペコリノ基、モルポリノ基、ビペラシノ基、アセチル基、イソブチリル基、シンナモイル基、フェニルアセチル基、ベンゾイル基、ｐ−トルオイル基、α−ナフトイル基、スクシニル基、フタロイル基、フマロイル基等が挙げられる。
【００１９】
２，３−ジメルカプトキノキサリンまたはその誘導体の典型例としては、２，３−ジメルカプトキノキサリン、６−エチル−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、６−イソプロピルキノキサリン−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−ジチオカーボネート、６，７−ジ（ｎ−ブチル）−２，３−ジメルカプトキノキサリン、Ｎ，Ｎ’−ジシクロヘキシル−３（２−メルカプトキノキサリル）スルフェンアミド、Ｎ−（ｎ−ブチル）−３（６−メチル−２−メルカプトキノキサリル）スルフェンアミド、６−イソプロピル−２−メルカプトキノキサリル−３−チオールアセテート、５，８−ジメチル−２−メルカプトキノキサリル−３−チオールベンゾエート、６−イソブチル−２−メルカプトキノキサリル−３−チオールセバケート等を挙げることができる。
２，３−ジメルカプトキノキサリンまたはその誘導体は、式（ＩＩ’）で示されるキノキサリン−２，３−ジチオカーボネート誘導体、特に６−メチルキノキサリン−２，３−ジチオカーボネートが好ましい。
【００２０】
ポリチオール系化合物又はその誘導体（加硫剤）の配合量はブレンドゴムの合計１００重量部に対して０．１〜１０重量部、好ましくは０．５〜５重量部である。配合量がこの範囲未満では加硫速度が低下し、一方この範囲を超えると得られた加硫物が剛直になりすぎてゴム加硫物に通常期待される物性が得られなくなる。エピクロルヒドリン系重合体ゴムとアクリロニトリルブタジエンゴムとのブレンド比に応じて、添加部数を調節することが好ましい。
【００２１】
チウラムスルフィド化合物は、一般式（ＩＩＩ）：
【化５】

［式中、Ｒ⁶とＲ⁷および／またはＲ⁸とＲ⁹は同一であっても異なってもよく、例えばアルキル基、アリール基、シクロアルキル基、アラルキル基である。Ｒ⁶とＲ⁷および／またはＲ⁸とＲ⁹は互いに結合して、ヘテロ原子を介してまたは介さずに、環を形成してよい。ｘは、１〜６の整数である。］
であってよい。
【００２２】
チウラムスルフィド化合物を例示すると、テトラメチルチウラムモノスルフィド、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モノスルフィド、テトラブチルチウラムジスルフィド、Ｎ,Ｎ′−ジメチル−Ｎ,Ｎ′−ジフェニルチウラムジスルフィド、ジペンタメチレンチウラムモノスルフィド、ジペンタメチレン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。
チウラムスルフィド化合物の配合量はブレンドゴムの合計１００重量部に対して０．１〜１０重量部、好ましくは０．５〜５重量部である。エピクロルヒドリン系重合体ゴムとアクリロニトリルブタジエンゴムとのブレンド比に応じて、添加部数を調節することが好ましい。
【００２３】
ジチオカルバミン酸塩類は、ジチオカルバミン酸の金属塩または金属を含まないジチオカルバミン酸塩のどちらであってもよい。
ジチオカルバミン酸の金属塩は、一般式（ＩＶ）：
【化６】

［式中、Ｒ¹⁰とＲ¹¹は同一であっても異なってもよく、例えばアルキル基、アリール基、シクロアルキル基、アラルキル基である。Ｒ¹⁰とＲ¹¹は互いに結合して、ヘテロ原子を介してまたは介さずに、環を形成してよい。Ｚは、金属原子である。ｎは、１〜４の整数である。］
であってよい。
【００２４】
ジチオカルバミン酸の金属塩における金属の例は、カリウム、ナトリウム、銅、亜鉛、鉄、テルル、鉛、セレン、カドミウム、ビスマスなどである。
ジチオカルバミン酸の金属塩としては、ジエチルジチオカルバミン酸テルル、ジメチルジチオカルバミン酸亜鉛、ジエチルジチオカルバミン酸亜鉛、ジブチルジチオカルバミン酸亜鉛、Ｎ−エチル−Ｎ−フェニルジチオカルバミン酸亜鉛、Ｎ−ペンタメチレンジチオカルバミン酸亜鉛、ジベンジルジチオカルバミン酸亜鉛、ジエチルジチオカルバミン酸ナトリウム、ジブチルジチオカルバミン酸ナトリウム、ジメチルジチオカルバミン酸銅、ジメチルジチオカルバミン酸第二鉄、ジメチルジチオカルバミン酸鉛、ジアミルジチオカルバミン酸鉛、ジメチルジチオカルバミン酸セレン、ジエチルジチオカルバミン酸セレン、ジエチルジチオカルバミン酸カドミウム、ジメチルジチオカルバミン酸ビスマス等が挙げられる。
【００２５】
金属を含まないジチオカルバミン酸塩類としては、ペンタメチレンジチオカルバミン酸ピペリジン塩、ピペコリルジチオカルバミン酸ピペリコン塩、ジメチルジチオカルバミン酸アンモニウム塩等が挙げられる。
【００２６】
ジチオカルバミン酸塩の配合量はブレンドゴムの合計１００重量部に対して０．１〜１０重量部、好ましくは０．５〜５重量部である。エピクロルヒドリン系重合体ゴムとアクリロニトリルブタジエンゴムとのブレンド比に応じて、添加部数を調節することが好ましい。
【００２７】
受酸剤は、金属化合物および／またはハイドロタルサイト類であってよい。
本発明組成物で用いられる受酸剤となる金属化合物を例示すると、それらの化合物には周期律表第II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、亜燐酸塩、周期律表第IVＡ族金属の酸化物、塩基性炭酸塩、塩基性カルボン酸塩、塩基性亜燐酸塩、三塩基性硫酸塩等がある。具体的には、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、亜燐酸カルシウム、亜鉛華、酸化錫、ステアリン酸錫、塩基性亜燐酸錫等を挙げることができる。
【００２８】
本発明組成物で用いられるハイドロタルサイト類は、一般式（Ｖ）：
Ｍｇ_xＺｎ_yＡｌ_z（ＯＨ）_2(x+y)+3z-2ＣＯ₃・ｗＨ₂Ｏ （Ｖ）
［式中、ｘ，ｙは０〜１０、ｘ＋ｙ＝１〜１０、ｚは１〜５、ｗは実数を表す。］
で示されるものであることが好ましい。
ハイドロタルサイト類は、例えば
Ｍｇ_xＡｌ_y（ＯＨ）_2x+3y-2ＣＯ₃・ｗＨ₂Ｏ （Ｖ’）
［式中、ｘは１〜１０、ｙは１〜５、ｗは実数を表す。］
であってよい。
ハイドロタルサイト類を例示すれば、Ｍｇ_4.5Ａｌ₂（ＯＨ）₁₃ＣＯ₃・３．５Ｈ₂Ｏ、Ｍｇ_4.5Ａｌ₂（ＯＨ）₁₃ＣＯ₃、Ｍｇ₄Ａｌ₂（ＯＨ）₁₂ＣＯ₃・３．５Ｈ₂Ｏ、Ｍｇ₆Ａｌ₂（ＯＨ）₁₆ＣＯ₃・４Ｈ₂Ｏ、Ｍｇ₅Ａｌ₂（ＯＨ）₁₄ＣＯ₃・４Ｈ₂Ｏ、Ｍｇ₃Ａｌ₂（ＯＨ）₁₀ＣＯ₃・１．７Ｈ₂Ｏ、Ｍｇ₃ＺｎＡｌ₂（ＯＨ）₁₂ＣＯ₃・ｗＨ₂Ｏ、Ｍｇ₃ＺｎＡｌ₂（ＯＨ）₁₂ＣＯ₃等を挙げることができる。
【００２９】
受酸剤は、通常ブレンドゴム材料の１００重量部に対して、１〜２０重量部、好ましくは１〜１０重量部の範囲で用いられる。この範囲未満では加硫速度が低下し、一方この範囲を超えると得られた加硫物が剛直になりすぎてゴム加硫物に通常期待される物性が得られなくなる。
【００３０】
チオウレア類は、促進助剤として働く。チオウレア類は、一般式（ＶＩ）：
【化７】

［式中、Ｒ¹²、Ｒ¹³、Ｒ¹⁴、Ｒ¹⁵の少なくとも１個は水素原子であり、他は、炭化水素基（炭素数例えば１〜３０、特に１〜１２）、例えばアルキル基、アリール基、シクロアルキル基、アラルキル基である。Ｒ¹³とＲ¹⁵は互いに結合して、環を形成してよい。］
で示されるものであってよい。
【００３１】
チオウレア類を例示すると、チオウレア、エチルチオウレア、ブチルチオウレア、ジエチルチオウレア、ジブチルチオウレア、トリメチルチオウレア、トリエチルチオウレア、トリブチルチオウレア、ジフェニルチオウレア、エチレンチオウレア、プロピレンチオウレア等が挙げられる。
【００３２】
チオウレア類の配合量は、ブレンドゴム材料の合計１００重量部に対して、１０重量部以下、例えば０．１〜５重量部、好ましくは０．５〜３重量部である。
【００３３】
本発明組成物には、上記成分の他に当該技術分野で行われる各種の老化防止剤、充填剤、補強剤、可塑剤、加工助剤、顔料、難燃剤等を任意に配合できる。
【００３４】
本発明加硫組成物の配合方法としては、従来ポリマー加工の分野において利用されている任意の手段、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利用することが出来る。
【００３５】
加硫物は、加硫用組成物を通常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、０．５〜３００分の間で行われるのが普通である。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出来る。
【００３６】
本発明の加硫物は、通常、エピクロルヒドリンゴムやアクリルニトリルブタジエンゴム等が使用される分野に広く応用することができる。例えば、各種ベルト、ホース、チューブ、ダイヤフラム等や、電子写真プロセスの帯電、現像、転写用のロール、ベルト材料等に使用することができる。
【００３７】
【発明の実施の形態】
本発明を実施するための具体的な形態を以下に実施例を挙げて説明する。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。
以下において、実施例１１および実施例１２が本発明の範囲に含まれる実施例であり、他の実施例（実施例１〜１０）は、本発明の範囲に含まれない参考例である。
【００３８】
実施例１〜１２、比較例１〜３
表１および表２に示す各材料をニーダー及びオープンロールで混練りし、ゴム組成物を作製した。得られたゴム組成物を１５×１５cmの金型に入れてプレス機にて、１６０℃、１００ｋg/cm²で２０分間加熱して、加硫物を得た。その結果を表３および表４に示す。
また、実施例３及び比較例１、２の組成物の加硫曲線を、ＪＳＲキュラストメーターIII型を用いて、振幅角３°、１６０℃で測定し、その結果を図１に示す。
【００３９】
ムーニースコーチ試験はJIS K 6300、加硫物の常態物性、圧縮永久歪、耐オゾン性はJIS K 6301に基づき測定した。
【００４０】
【表１】

【００４１】
【表２】

【００４２】
＊１ ダイソー社製「エピクロマ−Ｈ」、５０ＭＬ₁₊₄（１００℃）
＊２ ダイソー社製「エピクロマ−Ｃ」、エピクロルヒドリン/エチレンオキシド（５０／５０モル比）共重合体、６５ＭＬ₁₊₄（１００℃）
＊３ 日本合成ゴム社製「ＪＳＲ Ｎ２３０Ｓ」
＊４ 協和化学工業社製「ＤＨＴ−４Ａ」
【００４３】
【表３】

【００４４】
【表４】

【００４５】
以上の表において各実施例は、ポリチオール系化合物又はその誘導体を配合しない例（比較例１）及びチウラムスルフィド化合物あるいはジチオカルバミン酸塩類を配合しない例（比較例２）と比べて、速やかな加硫速度が得られ、圧縮永久歪みも改善されていることが判る。
【００４６】
【発明の効果】
本発明によれば、速やかな加硫速度と改善された圧縮永久歪みとともに、受酸剤として有害な鉛化合物を含まない、共加硫可能なブレンドゴム組成物が得られる。
【図面の簡単な説明】
【図１】 実施例３及び比較例１、２の組成物の加硫曲線である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a blend rubber vulcanizing composition of epichlorohydrin polymer rubber and acrylonitrile butadiene rubber, which does not contain harmful lead compounds.
[0002]
[Prior art]
Acrylonitrile butadiene rubber is a rubber that is widely used industrially as an oil resistant rubber, but is inferior in heat resistance and ozone resistance. On the other hand, epichlorohydrin rubber has an excellent balance between heat resistance and ozone resistance, and is industrially valuable if the above-mentioned drawbacks are compensated by blend vulcanization. However, the effective vulcanizing agents for both are usually different.
[0003]
British Patent 1246039 has obtained a vulcanized blend of a good ozone resistant acrylonitrile butadiene rubber and epichlorohydrin rubber cured with a lead compound, but these vulcanizates contain lead compounds which present problems.
In addition, vulcanized blends using 2-mercaptoimidazoline, which is a vulcanizing agent for epichlorohydrin rubber, and tetramethylthiuram sulfide, which is a vulcanizing agent for nitrile rubber, have been reported, but these also contain lead compounds as metal oxides. ("Synthetic Rubber Processing Technology Complete Book 12" P.129-131, issued on January 31, 1980 (Taisei)).
[0004]
JP-A-8-41248 proposes a vulcanized blend of acrylonitrile butadiene rubber and epichlorohydrin rubber having good heat and ozone resistance which is cured by a sulfur curing agent and a peroxide curing system. However, in this proposal, the use of an epichlorohydrin-allyl glycidyl ether binary copolymer and an epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer containing allyl glycidyl ether for sufficient curing with sulfur or peroxide. It is limited to.
[0005]
In addition, epichlorohydrin rubber is used for semiconductive elastic roll applications such as electrophotographic copying machines and printers, and blends with acrylonitrile butadiene rubber have been proposed (Japanese Patent Laid-Open No. Hei 8-292640). In the same manner as described above, unsaturated epoxides such as allyl glycidyl ether are essential components for vulcanization with sulfur or peroxide. For example, when used for these roll applications, the surface property and resistance of the roll may be changed due to degradation to ozone or the like, so that excellent ozone properties are required. In addition, since both ends are used with a load applied, the load deformation is often repeated over a long period of time, and rubber sag becomes a problem. Therefore, excellent compression set is required.
[0006]
[Problems to be solved by the invention]
An object of the present invention is to provide a blend rubber vulcanizing composition of epichlorohydrin polymer rubber and acrylonitrile butadiene rubber which does not contain harmful lead compounds as described above.
[0007]
[Means for Solving the Problems]
As a result of intensive studies on the blend rubber composition, the present inventors have found that the above-mentioned object can be achieved by blending the following components (a) to (e) at a predetermined ratio. It has been completed.
(A) Epichlorohydrin polymer rubber.
(B) Acrylonitrile butadiene rubber.
(C) A polythiol compound or a derivative thereof that functions as a vulcanizing agent.
(D) Thiuram sulfide compounds and / or dithiocarbamates that function as promoters.
(E) Metal compounds and / or hydrotalcites that function as acid acceptors.
In addition, it has been found that if the thiourea (f) component is blended at a predetermined ratio in addition to the components (a) to (e), the compression set is further improved.
[0008]
The present invention comprises (a) 5 to 95% by weight of epichlorohydrin polymer rubber,
(B) Acrylonitrile butadiene rubber 95-5% by weight
For 100 parts by weight of the blended rubber,
(C) 0.1 to 10 parts by weight of a polythiol compound or a derivative thereof,
(D) 0.1 to 10 parts by weight of a thiuram sulfide compound and / or dithiocarbamate, and (e) 1 to 20 parts by weight of at least one acid acceptor selected from metal compounds and hydrotalcites. A vulcanizing composition characterized by the following is provided:
The present invention also provides a vulcanizing composition containing (f) 0.1 to 5 parts by weight of thioureas in addition to the components (a) to (e).
[0010]
The epichlorohydrin polymer rubber of the present invention refers to an epichlorohydrin homopolymer or a copolymer of epichlorohydrin and other epoxides such as ethylene oxide, propylene oxide, allyl glycidyl ether and the like.
Epichlorohydrin-based polymers include epichlorohydrin-ethylene oxide copolymer, epichlorohydrin-propylene oxide copolymer, epichlorohydrin-allyl glycidyl ether copolymer, epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer, epichlorohydrin-propylene oxide-allyl. Examples thereof include glycidyl ether terpolymers, epichlorohydrin-ethylene oxide-propylene oxide-allyl glycidyl ether quaternary copolymers, and the like. These copolymers preferably contain at least 10 mol% of epichlorohydrin component from the viewpoint of ensuring a practical vulcanization rate.
[0011]
In the present invention, these single rubbers or two or more mixed rubbers are used. The molecular weight of the epichlorohydrin polymer rubber may be about ML _{1 + 4} (100 ° C.) of 30 to 150 according to Mooney viscosity display.
[0012]
The acrylonitrile butadiene rubber used in the present invention means a terpolymer of acrylonitrile and butadiene or a terpolymer of acrylonitrile, butadiene and unsaturated carboxylic acid, so-called high nitrile, medium high nitrile, medium nitrile, This is what is commonly referred to as low nitrile, carboxonitrile or the like.
[0013]
In the mixture of epichlorohydrin rubber and acrylonitrile butadiene rubber in the composition of the present invention, the amount of the latter can vary within a wide range depending on the purpose, but is 5 to 95% by weight, for example, 20 to 80% by weight in the mixture.
[0014]
The polythiol compound or derivative thereof may be a triazine compound having at least two mercapto groups. The polythiol compound or its derivative is represented by the general formula (I):
[Chemical 3]

[Wherein, R ¹ is a group selected from the group consisting of a mercapto group, an alkoxy group, an alkylamino group, a dialkylamino group, a cycloalkylamino group, a dicycloalkylamino group, and an arylamino group. ]
The mercaptotriazine compound represented by these may be sufficient.
[0015]
Examples of the mercaptotriazine compound include 2,4,6-trimercapto-1,3,5-triazine, 1-methoxy-3,5-dimercaptotriazine, 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- Examples include phenylamino-3,5-dimercaptotriazine.
In particular, 2,4,6-trimercapto-1,3,5-triazine is preferred.
[0016]
The polythiol-based compound or a derivative thereof may be a quinoxaline derivative having a mercapto group, such as 2,3-dimercaptoquinoxaline or a derivative thereof.
[0017]
2,3-dimercaptoquinoxaline or a derivative thereof is a compound represented by the following general formula (II) or (II ′).
[Formula 4]

[Wherein, R ² , R ³ , R ⁴ and R ⁵ may be the same or different and each is a group having 1 to 8 carbon atoms selected from hydrogen or an alkyl group.
A ¹ and A ² may be the same or different, and are groups selected from hydrogen, alkali metal, —N (A ³ ) A ⁴ , and —C (═O) A ⁵ .
(A ³ and A ⁴ may be the same or different and each is a group having 1 to 12 carbon atoms selected from hydrogen, an alkyl group, a cycloalkyl group, an aryl group, and an aralkyl group, and A ³ and A ⁴ are bonded to each other. May form a hydrocarbon ring, or may be bonded via a hetero atom to form a heterocyclic ring.
A ⁵ is a group having 1 to 18 carbon atoms selected from an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, and an aralkyl group, or a structure of —A ⁶ —COOH, and A ⁶ is selected from an alkylene group and an alkenylene group. A group having 1 to 8 carbon atoms or a group having 6 to 12 carbon atoms selected from a cycloalkylene group, an arylene group and an aralkylene group, or having the same structure as -A ⁶ -C (═O) — An ester bond may be formed with the thiol group of 2,3-dimercaptoquinoxaline or another derivative thereof in the molecule or another. ]]
[0018]
Examples of the alkyl group forming R ² , R ³ , R ⁴ , and R ⁵ include a methyl group, an ethyl group, an isopropyl group, an n-butyl group, an isobutyl group, and an n-hexyl group.
As A ¹ and A ² , for example, an amino group, an ethylamino group, a diethylamino group, a dioctylamino group, a cyclohexylamino group, a dicyclohexylamino group, an anilino group, a monobenzylamino group, a biperidino group, a pipecolino group, a morpholino group, a biperacino group Group, acetyl group, isobutyryl group, cinnamoyl group, phenylacetyl group, benzoyl group, p-toluoyl group, α-naphthoyl group, succinyl group, phthaloyl group, fumaroyl group and the like.
[0019]
Typical examples of 2,3-dimercaptoquinoxaline or derivatives thereof include 2,3-dimercaptoquinoxaline, 6-ethyl-2,3-dimercaptoquinoxaline, quinoxaline-2,3-dithiocarbonate, 6-methylquinoxaline- 2,3-dithiocarbonate, 6-isopropylquinoxaline-2,3-dithiocarbonate, 5,8-dimethylquinoxaline-2,3-dithiocarbonate, 6,7-di (n-butyl) -2,3-dimercapto Quinoxaline, N, N′-dicyclohexyl-3 (2-mercaptoquinoxalyl) sulfenamide, N- (n-butyl) -3 (6-methyl-2-mercaptoquinoxalyl) sulfenamide, 6-isopropyl 2-mercaptoquinoxalyl-3-thiol acetate, 5,8-dimethyl-2- Examples include mercaptoquinoxalyl-3-thiol benzoate and 6-isobutyl-2-mercaptoquinoxalyl-3-thiol sebacate.
The 2,3-dimercaptoquinoxaline or a derivative thereof is preferably a quinoxaline-2,3-dithiocarbonate derivative represented by the formula (II ′), particularly 6-methylquinoxaline-2,3-dithiocarbonate.
[0020]
The compounding quantity of a polythiol type compound or its derivative (vulcanizing agent) is 0.1-10 weight part with respect to a total of 100 weight part of blend rubber, Preferably it is 0.5-5 weight part. If the blending amount is less than this range, the vulcanization rate decreases. On the other hand, if it exceeds this range, the resulting vulcanizate becomes too rigid and the physical properties normally expected for rubber vulcanizates cannot be obtained. It is preferable to adjust the number of added parts according to the blend ratio of the epichlorohydrin polymer rubber and the acrylonitrile butadiene rubber.
[0021]
The thiuram sulfide compound has the general formula (III):
[Chemical formula 5]

[Wherein, R ⁶ and R ⁷ and / or R ⁸ and R ⁹ may be the same or different and are, for example, an alkyl group, an aryl group, a cycloalkyl group, or an aralkyl group. R ⁶ and R ⁷ and / or R ⁸ and R ⁹ may be bonded to each other to form a ring with or without a heteroatom. x is an integer of 1-6. ]
It may be.
[0022]
Examples of thiuram sulfide compounds include tetramethyl thiuram monosulfide, tetramethyl thiuram disulfide, tetraethyl thiuram disulfide, tetrabutyl thiuram monosulfide, tetrabutyl thiuram disulfide, N, N'-dimethyl-N, N'-diphenyl thiuram disulfide, di Examples include pentamethylene thiuram monosulfide, dipentamethylene thiuram disulfide, dipentamethylene thiuram tetrasulfide, and dipentamethylene thiuram hexasulfide.
The blending amount of the thiuram sulfide compound is 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the blend rubber. It is preferable to adjust the number of added parts according to the blend ratio of the epichlorohydrin polymer rubber and the acrylonitrile butadiene rubber.
[0023]
The dithiocarbamate may be either a metal salt of dithiocarbamate or a metal-free dithiocarbamate.
The metal salt of dithiocarbamic acid has the general formula (IV):
[Chemical 6]

[Wherein, R ¹⁰ and R ¹¹ may be the same or different and are, for example, an alkyl group, an aryl group, a cycloalkyl group, or an aralkyl group. R ¹⁰ and R ¹¹ may be bonded to each other to form a ring through or without a heteroatom. Z is a metal atom. n is an integer of 1 to 4. ]
It may be.
[0024]
Examples of the metal in the metal salt of dithiocarbamic acid are potassium, sodium, copper, zinc, iron, tellurium, lead, selenium, cadmium, bismuth and the like.
Examples of the metal salt of dithiocarbamic acid include tellurium diethyldithiocarbamate, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc dibutyldithiocarbamate, zinc N-ethyl-N-phenyldithiocarbamate, zinc N-pentamethylenedithiocarbamate, dibenzyldithiocarbamine Zinc oxide, sodium diethyldithiocarbamate, sodium dibutyldithiocarbamate, copper dimethyldithiocarbamate, ferric dimethyldithiocarbamate, lead dimethyldithiocarbamate, lead diamyldithiocarbamate, selenium dimethyldithiocarbamate, selenium diethyldithiocarbamate, cadmium diethyldithiocarbamate And bismuth dimethyldithiocarbamate.
[0025]
Examples of metal-free dithiocarbamates include pentamethylenedithiocarbamic acid piperidine salt, pipecolyldithiocarbamic acid pipericone salt, and dimethyldithiocarbamic acid ammonium salt.
[0026]
The amount of dithiocarbamate is 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the total blend rubber. It is preferable to adjust the number of added parts according to the blend ratio of the epichlorohydrin polymer rubber and the acrylonitrile butadiene rubber.
[0027]
The acid acceptor may be a metal compound and / or hydrotalcite.
Examples of metal compounds used as acid acceptors used in the composition of the present invention include Group II metal oxides, hydroxides, carbonates, carboxylates, silicates, borates of the periodic table. Examples thereof include acid salts, phosphites, oxides of Group IVA metals of the periodic table, basic carbonates, basic carboxylates, basic phosphites, and tribasic sulfates. Specifically, 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, Examples thereof include tin oxide, tin stearate, and basic tin phosphite.
[0028]
The hydrotalcites used in the composition of the present invention are represented by the general formula (V):
_{Mg x Zn y Al z (OH} ) 2 (x + y) + 3z-2 CO 3 · wH 2 O (V)
[Wherein, x and y are 0 to 10, x + y = 1 to 10, z is 1 to 5, and w is a real number. ]
It is preferable that it is shown by these.
Hydrotalcite, for example _{Mg x Al y (OH) 2x} + 3y-2 CO 3 · wH 2 O (V ')
[Wherein x represents 1 to 10, y represents 1 to 5, and w represents a real number. ]
It may be.
Examples of hydrotalcites 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.
[0029]
The acid acceptor is usually used in an amount of 1 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the blend rubber material. If it is less than this range, the vulcanization rate will decrease, while if it exceeds this range, the resulting vulcanizate will be too rigid and the physical properties normally expected of a rubber vulcanizate will not be obtained.
[0030]
Thioureas act as accelerating aids. Thioureas have the general formula (VI):
[Chemical 7]

[Wherein, at least one of R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ is a hydrogen atom, and the other is a hydrocarbon group (for example, having 1 to 30 carbon atoms, particularly 1 to 12 carbon atoms) such as an alkyl group or an aryl group. Group, cycloalkyl group and aralkyl group. R ¹³ and R ¹⁵ may combine with each other to form a ring. ]
It may be shown by.
[0031]
Examples of thioureas include thiourea, ethylthiourea, butylthiourea, diethylthiourea, dibutylthiourea, trimethylthiourea, triethylthiourea, tributylthiourea, diphenylthiourea, ethylenethiourea, propylenethiourea and the like.
[0032]
The blending amount of thioureas is 10 parts by weight or less, for example, 0.1 to 5 parts by weight, preferably 0.5 to 3 parts by weight, based on 100 parts by weight of the blend rubber material.
[0033]
In addition to the above-mentioned components, the present invention composition can be arbitrarily mixed with various anti-aging agents, fillers, reinforcing agents, plasticizers, processing aids, pigments, flame retardants and the like used in the technical field.
[0034]
As a blending method of the vulcanized composition of the present invention, any 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.
[0035]
The vulcanized product is obtained by heating the vulcanizing composition to usually 100 to 200 ° C. The vulcanization time varies depending on the temperature, but it is usually between 0.5 and 300 minutes. As a method of vulcanization molding, any method such as compression molding using a mold, injection molding, a steam can, an air bath, infrared rays, or heating by microwaves can be used.
[0036]
The vulcanizate of the present invention can be widely applied to fields where epichlorohydrin rubber, acrylonitrile butadiene rubber or the like is usually used. For example, it can be used for various belts, hoses, tubes, diaphragms, etc., electrophotographic process charging, development, transfer rolls, belt materials, and the like.
[0037]
DETAILED DESCRIPTION OF THE INVENTION
Specific modes for carrying out the present invention will be described below with reference to examples. However, the present invention is not limited to the following examples without departing from the gist thereof.
In the following, Example 11 and Example 12 are examples included in the scope of the present invention, and the other examples (Examples 1 to 10) are reference examples not included in the scope of the present invention.
[0038]
Examples 1-12, Comparative Examples 1-3
Each material shown in Table 1 and Table 2 was kneaded with a kneader and an open roll to prepare a rubber composition. The resulting rubber composition was placed in a 15 × 15 cm mold and heated with a press at 160 ° C. and 100 kg / cm ² for 20 minutes to obtain a vulcanizate. The results are shown in Tables 3 and 4.
Further, the vulcanization curves of the compositions of Example 3 and Comparative Examples 1 and 2 were measured at an amplitude angle of 3 ° and 160 ° C. using JSR Clastometer Type III, and the results are shown in FIG.
[0039]
The Mooney scorch test was measured based on JIS K 6300, and normal properties, compression set, and ozone resistance of the vulcanizate were measured based on JIS K 6301.
[0040]
[Table 1]

[0041]
[Table 2]

[0042]
* 1 Daiso "Epichroma-H", 50ML _{1 + 4} (100 ° C)
* 2 “Epichroma-C” manufactured by Daiso Corporation, epichlorohydrin / ethylene oxide (50/50 molar ratio) copolymer, 65ML _{1 + 4} (100 ° C.)
* 3 “JSR N230S” manufactured by Nippon Synthetic Rubber Co., Ltd.
* 4 “DHT-4A” manufactured by Kyowa Chemical Industry Co., Ltd.
[0043]
[Table 3]

[0044]
[Table 4]

[0045]
In the above table, each example shows a faster vulcanization rate than the example in which no polythiol compound or its derivative is blended (Comparative Example 1) and the example in which no thiuram sulfide compound or dithiocarbamate is blended (Comparative Example 2). It can be seen that compression set is also improved.
[0046]
【The invention's effect】
According to the present invention, a co-vulcanizable blend rubber composition is obtained that has a rapid vulcanization rate and improved compression set and does not contain a harmful lead compound as an acid acceptor.
[Brief description of the drawings]
1 is a vulcanization curve of compositions of Example 3 and Comparative Examples 1 and 2. FIG.

Claims (3)

(A) Epichlorohydrin homopolymer or epichlorohydrin-based polymer rubber that is an epichlorohydrin -ethylene oxide copolymer, 5 to 95% by weight,
(B) Acrylonitrile butadiene rubber 95-5% by weight
For 100 parts by weight of the blended rubber,
(C) General formula (II) or (II ′):

[Wherein, R ² , R ³ , R ⁴ and R ⁵ may be the same or different and each is a group having 1 to 8 carbon atoms selected from hydrogen or an alkyl group.
A ¹ and A ² may be the same or different, and are groups selected from hydrogen, alkali metal, —N (A ³ ) A ⁴ , and —C (═O) A ⁵ .
(A ³ and A ⁴ may be the same or different and each is a group having 1 to 12 carbon atoms selected from hydrogen, an alkyl group, a cycloalkyl group, an aryl group, and an aralkyl group, and A ³ and A ⁴ are bonded to each other. May form a hydrocarbon ring, or may be bonded via a hetero atom to form a hetero ring.
A ⁵ is a group having 1 to 18 carbon atoms selected from an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, and an aralkyl group, or a structure of —A ⁶ —COOH, and A ⁶ is selected from an alkylene group and an alkenylene group. A group having 1 to 8 carbon atoms or a group having 6 to 12 carbon atoms selected from a cycloalkylene group, an arylene group and an aralkylene group, or having the same structure as -A ⁶ -C (═O) — An ester bond may be formed with the thiol group of 2,3-dimercaptoquinoxaline or another derivative thereof in the molecule or another. ]]
0.1 to 10 parts by weight of a polythiol compound or a derivative thereof , which is 2,3-dimercaptoquinoxaline or a derivative thereof represented by :
(D) 0.1 to 10 parts by weight of a thiuram sulfide compound and / or dithiocarbamate,
(E) Formula (IV ′):
_{Mg x Al y (OH) 2x} + 3y-2 CO 3 · wH 2 O (IV ')
[Wherein x represents 1 to 10, y represents 1 to 5, and w represents a real number. ]
Acid acceptor 20 parts by weight of hydrotalcite is a compound represented in, and
(F) A vulcanizing composition comprising 0.1 to 5 parts by weight of a thiourea . The vulcanizing composition according to claim 1 , wherein the epichlorohydrin polymer rubber (a) is an epichlorohydrin homopolymer . A vulcanized product obtained by vulcanizing the vulcanizing composition according to claim 1 .

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