JP2005036141A - Blend rubber composition for vulcanization - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blend rubber composition for vulcanization excellent in ozone resistance and permanent compression set. <P>SOLUTION: The blend rubber composition for vulcanization is obtained by compounding a blend rubber composed of (a) 5-95 wt.% chlorinated polyethylene and (b) 95-5 wt.% nitrile rubber with (c) a thiadiazole-based vulcanizer, (d) a metal compound which becomes an acid-receiving agent and (e) an organic vulcanization accelerator. Physical properties of vulcanized rubber product are further improved by compounding, as necessary, (f) sulfur or a sulfur-donating agent and (g) an inorganic vulcanization accelerator in addition to these components (a) to (e) in the blend rubber composition. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a blend rubber vulcanizing composition obtained by blending chlorinated polyethylene and nitrile rubber, and a vulcanized product thereof.

  Nitrile rubber is a rubber that is widely used industrially as an oil-resistant rubber, but has a drawback that the weather resistance and ozone resistance are extremely inferior. On the other hand, chlorinated polyethylene is excellent in weather resistance, ozone resistance, and flame retardancy, and it is industrially valuable if both of the above drawbacks of nitrile rubber are compensated by blend vulcanization. I think. However, the vulcanization system of nitrile rubber and chlorinated polyethylene is quite different, especially zinc white, which is commonly used as a vulcanization accelerator in vulcanization of nitrile rubber, is a strong dehydrochlorination accelerator against chlorinated polyethylene. Thus, the heat resistance is extremely lowered. Therefore, it is practically very valuable to use a nitrile rubber vulcanization system blended with zinc white for co-vulcanization with chlorinated polyethylene.

In addition, as a vulcanizing agent in the co-vulcanization of nitrile rubber and chlorinated polyethylene, a vulcanizing agent combining sulfur and mercaptotriazines with a dithiocarbamate (Japanese Patent Publication No. 55-21053), sulfur and trithiocyanuric acid. A vulcanizing agent (Japanese Examined Patent Publication No. Sho 59-23579) in which thiuram sulfides or a specific basic amine compound is blended with a vulcanized system is proposed, but the physical properties are insufficient due to the content of chlorinated polyethylene. There is a case.
Japanese Examined Patent Publication No. 55-21053 Japanese Patent Publication No.59-23579 JP 2000-63685 A

  An object of the present invention is to provide a blend rubber vulcanizing composition having excellent ozone resistance and compression set properties in view of the above-described actual situation.

  As a result of various studies to solve the above problems, the present inventors have found that it is possible to add a thiadiazole compound as a vulcanizing agent and a metal compound as an acid acceptor to co-vulcanize nitrile rubber and chlorinated polyethylene. It was found that a blend rubber composition which is very effective in the above-mentioned method and has excellent ozone resistance and compression set can be obtained, and the present invention has been completed.

That is, the blend rubber vulcanizing composition according to the present invention is
(A) 5 to 95% by weight of chlorinated polyethylene and (b) 95 to 5% by weight of nitrile rubber
To blend rubber consisting of
(C) A thiadiazole-based vulcanizing agent (d) a metal compound that serves as an acid acceptor (e) an organic vulcanization accelerator is blended.
Furthermore, the blend rubber composition according to the present invention is characterized in that, in addition to the above (a) to (e), (f) sulfur or a sulfur donor and (g) an inorganic vulcanization accelerator are blended as necessary. The vulcanization speed and compression set can be improved by blending the component (f) and the component (g).

The blend rubber used in the present invention comprises (a) 5 to 95% by weight of chlorinated polyethylene and (b) 95 to 5% by weight of nitrile rubber. If the amount is less than 5% by weight, the effect of adding chlorinated polyethylene is not sufficiently exhibited in ozone resistance.

  The (a) chlorinated polyethylene used in the present invention is obtained by chlorinating polyethylene powder or particles in an aqueous suspension or an organic solvent. The polyethylene used as a raw material is an ethylene homopolymer or a copolymer with a comonomer copolymerizable with ethylene. Examples of comonomers include α-olefins such as propylene, 1-butene, 1-pentene, 1-hexene, 1-octene and 4-methyl-pentene-1; unsaturated acetates such as vinyl acetate and allyl acetate; (Meth) acrylic acid; (meth) acrylic acid esters such as methyl (meth) acrylate and ethyl (meth) acrylate may be mentioned. The weight average molecular weight of polyethylene is preferably 40,000 to 700,000, more preferably 50,000 to 300,000. The polyethylene used as a raw material may be a blend of low density polyethylene in addition to high density polyethylene. The chlorine content of the chlorinated polyethylene used in the present invention is preferably 20 to 50% by weight, more preferably 25 to 45% when the vulcanized product is used as a vulcanized rubber. Whether the chlorine content is too high or too low, the resulting composition may be too hard. Amorphous or substantially amorphous chlorinated polyethylene is preferred.

  The (b) nitrile rubber used in the present invention means a secondary copolymer of acrylonitrile and butadiene or a terpolymer of acrylonitrile, butadiene and unsaturated carboxylic acid. Nitriles, medium nitrites, low nitriles, carboxyl nitriles and the like are commonly used.

式(１)および(２) 中、Ｒ¹ およびＲ² は、互いに同一であっても異なっていてもよく、水素原子、基−（Ｃ＝Ｏ）Ｒ３ 、または基−Ｒ４ＯＲ５ である。ここでＲ３は、炭素数１〜１７のアルキル基、１つまたは２つの環を持つアリール基、炭素数７〜１４のアシル基、炭素数７〜８のアラルキル基またはシクロヘキシル基であり、Ｒ４は炭素数１〜８のアルキレン基、Ｒ５は炭素数１〜８のアルキル基である。 Examples of the (c) thiadiazole compound used in the present invention include compounds represented by the following general formulas (1), (2), (3) and (4). Preference is given to compounds of the formula (1) or (2), in particular compounds of the formula (1).

In formulas (1) and (2), R ¹ And R ² May be the same as or different from each other, and may be a hydrogen atom, a group — (C═O) R 3. Or a group -R4OR5 It is. Here, R3 is an alkyl group having 1 to 17 carbon atoms, an aryl group having one or two rings, an acyl group having 7 to 14 carbon atoms, an aralkyl group having 7 to 8 carbon atoms, or a cyclohexyl group, and R4 is A C1-C8 alkylene group and R5 are C1-C8 alkyl groups.

式（３）および（４） 中、ｎは１〜２であり、Ｘは酸素原子または硫黄原子であり、Ｒ６ およびＲ７ は、互いに同一であっても異なっていてもよく、炭素数１〜８のアルキル基であり、Ｒ８およびＲ９は、互いに同一であっても異なっていてもよく、水素原子または炭素数１〜８のアルキル基である。

In the formulas (3) and (4), n is 1 to 2, X is an oxygen atom or a sulfur atom, R6 And R7 May be the same as or different from each other, and is an alkyl group having 1 to 8 carbon atoms, and R8 and R9 may be the same or different from each other, and may be a hydrogen atom or 1 to 8 carbon atoms. It is an alkyl group.

   (c) The use amount of the thiadiazole vulcanizing agent is preferably 0.1 to 5 parts by weight, more preferably 0.5 to 3 parts by weight with respect to 100 parts by weight of the blend rubber.

  Examples of thiadiazole vulcanizing agents include 2,5-dimercapto-1,3,4-thiadiazole, monobenzoate derivatives of 2,5-dimercapto-1,3,4-thiadiazole, and 2,5-dimercapto-1,3, Examples of the dibenzoate derivatives of 4-thiadiazole include 2,5-dimercapto-1,3,4-thiadiazole, 5-mercapto-1,3,4-thiadiazole-2-thiobenzoate, 1 , 3,4-thiadiazolyl-2,5-dithiobenzoate, 5-mercapto-1,3,4-thiadiazole-2-thiostearate, 5-mercapto-1,3,4-thiadiazole-2-thio-1 Naphthoate, 5-mercapto-1,3,4-thiadiazole-2-thiophenyl acetate, 5-mercapto-1 3,4-thiadiazole-2-thiocyclohexylcarboxylate, 5-mercapto-1,3,4-thiadiazole-2-thio-p-toluate, 5-mercapto-1,3,4-thiadiazole-2-thiocinnamate 2,5-di (butoxymethyl) -1,3,4-thiadiazole, 2,2′-dimercapto-5,5′-dithiobis (1,3,4-thiadiazole), 2,2′-di (butoxy) Methyl) -5,5′-dithiobis (1,3,4-thiadiazole) and the like.

  The metal compound used as the acid acceptor (d) used in the present invention is a compound that supplements hydrogen chloride released from chlorinated polyethylene during vulcanization, and is a metal oxide such as a zeolitic compound, magnesium oxide, or calcium oxide. Examples thereof include metal oxides such as magnesium hydroxide and calcium hydroxide, hydrotalcite such as synthetic hydrotalcite, lead white, red lead, and resurge. (d) The metal compound serving as the acid acceptor is preferably 0.5 to 30 parts by weight, more preferably 3 to 25 parts by weight, based on 100 parts by weight of the blend rubber.

  Zeolite compounds are natural zeolite, A-type, X-type, Y-type synthetic zeolite, sodalite, natural or synthetic mordenite, various zeolites such as ZSM-5, and metal substitutes thereof. These may be used alone or in combination of two or more. Further, the metal of the metal substitution product is often sodium. As the zeolitic compound, those having a large acid-accepting capacity are preferable. Methods for producing synthetic zeolite are known. For example, in hydrothermal synthesis, alkali or alkaline earth oxides (bases), alumina, silica, and water are used as starting materials, and these are usually used at a temperature of 100 ° C. or higher. After the reaction, zeolite crystals are precipitated. In addition, natural silicate minerals such as kaolin compounds, clay minerals such as allophane, and volcanic glass can also be used as starting materials. For example, as disclosed in Japanese Patent Application Laid-Open No. 29-1119, there is a method of producing synthetic zeolite by reacting dilute sodium aluminate with activated silicic acid obtained by acid treatment of acid clay (montmorite). .

  It is preferable to use an activated zeolitic compound as the zeolitic compound. The activated zeolitic compound means a material with substantially less water, and as a method for activating the zeolitic compound in this way, the zeolitic compound is heated at a temperature of 100 ° C. or higher under dry air or nitrogen stream. Examples thereof include a method of dehydration or a method of activating by adding a zeolite compound and exposing it to a kneading temperature of 140 to 200 ° C. when kneading the chlorine-containing polymer with other components.

  The (e) organic vulcanization accelerator used in the present invention is a primary, secondary, tertiary amine, an organic acid salt of the amine or an adduct thereof, an aldehyde ammonia accelerator, an aldehyde amine accelerator, Guanidine accelerators, thiazole accelerators, sulfenamide accelerators, thiuram accelerators and dithiocarbamic acid accelerators, 1,8-diazabicyclo (5,4,0) undecene-7 and its weak acid salts, No. 4 A quaternary ammonium compound, a fatty acid, or a combination of two or more thereof. However, the vulcanization accelerator is not limited to these. The amount of the organic vulcanization accelerator used is preferably 0.5 to 3 mol, more preferably 0.7 to 1.5 mol, per 1 mol of the (c) thiadiazole vulcanizing agent.

  As the primary, secondary and tertiary amines, primary, secondary or tertiary amines of aliphatic or cyclic fatty acids having 5 to 20 carbon atoms are particularly preferred, and typical examples of such amines are n-hexyl. Amine, octylamine, dibutylamine, tributylamine, trioctylamine, di (2-ethylhexyl) amine, dicyclohexylamine, hexamethylenediamine and the like.

  Examples of the organic acid that forms a salt with the amine include carboxylic acid, carbamic acid, 2-mercaptobenzothiazole, and dithiophosphoric acid. Examples of the substance that forms an adduct with the amine include alcohols and oximes. Specific examples of the organic acid salt or adduct of amine include n-butylamine / acetate, dibutylamine / oleate, hexamethylenediamine / carbamate, and dicyclohexylamine salt of 2-mercaptobenzothiazole.

  Examples of the aldehyde ammonia accelerator include hexamethylenetetramine, a reaction product of acetaldehyde and ammonia, and the like.

  Examples of aldehyde amine accelerators are condensation products of an amine and at least one aldehyde having 1 to 7 carbon atoms. Examples of such amines include aniline and butylamine. Among these, a condensation product of aniline and at least one aldehyde having 1 to 7 carbon atoms is preferable. Specific examples include a condensate of aniline and butyraldehyde, a condensate of aniline and heptaldehyde, a condensate of aniline, acetaldehyde and butyraldehyde.

  Examples of guanidine accelerators include diphenyl guanidine and ditolyl guanidine.

  Examples of thiazole accelerators include 2-mercaptobenzothiazole, dibenzothiazyl disulfide, zinc salt of 2-mercaptobenzothiazole, and the like.

式(５)中、Ｒ１０およびＲ１１は、互いに同一であっても異なっていてもよく、炭素数１〜１２のシクロアルキル基、炭素数１〜１２のアラルキル基である。ただしＲ１０およびＲ１１が共に水素原子であることはない。Ｒ１０および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、環を形成していてもよい。スルフェンアミドを形成する１級もしくは２級アミンとしては、シクロヘキシルアミン、ブチルアミン類、ジエチルアミン、ジプロピルアミン類、ジオクチルアミン類、ジラウリルアミン類、ジシクロヘキシルアミン、ピペリジン、ピペコリン、モルホリン、ピペラジン等が例示される。スルフェンアミド系加硫促進剤の具体例としては、Ｎ−エチル−２−ベンゾチアジルスルフェンアミド、Ｎ−ｔ−ブチル−２−ベンゾチアジルスルフェンアミド、Ｎ,Ｎ−ジ−イソプロピル−２−ベンゾチアジルスルフェンアミド、Ｎ,Ｎ−ジ−シクロヘキシル−２−ベンゾチアジルスルフェンアミド、Ｎ−オキシ−ジ−エチレン−２−ベンゾチアジルスルフェンアミドなどが挙げられる。 As the sulfenamide-based accelerator, a primary or secondary amine 2-benzothiazylsulfenamide is represented by the following general formula (5).

In formula (5), R10 and R11 may be the same as or different from each other, and are a cycloalkyl group having 1 to 12 carbon atoms or an aralkyl group having 1 to 12 carbon atoms. However, R10 and R11 are not both hydrogen atoms. R10 and R11 may be bonded to each other to form a ring through or without a heteroatom. Examples of primary or secondary amines that form sulfenamide include cyclohexylamine, butylamines, diethylamine, dipropylamines, dioctylamines, dilaurylamines, dicyclohexylamine, piperidine, pipecoline, morpholine, piperazine, etc. Is done. Specific examples of the sulfenamide vulcanization accelerator include N-ethyl-2-benzothiazylsulfenamide, Nt-butyl-2-benzothiazylsulfenamide, N, N-di-isopropyl- Examples include 2-benzothiazylsulfenamide, N, N-di-cyclohexyl-2-benzothiazylsulfenamide, and N-oxy-di-ethylene-2-benzothiazylsulfenamide.

式（６）中、Ｒ¹²とＲ¹³、および／または、Ｒ¹⁴とＲ¹⁵は同一もしくは異なり、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。Ｒ¹²とＲ¹³、および／または、Ｒ¹⁴とＲ¹⁵は互いに結合して、ヘテロ原子を介してまたは介さずに、環を形成していてもよい。Ｘは、1〜4である。チウラムの化合物の具体例としては、テトラメチルチウラムジスルフィド、テトラメチルチウラムモノスルフィド、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等が挙げられる。 As an example of the thiuram accelerator, the thiuram compound is a thiuram sulfide compound represented by the following general formula (6).

In the formula (6), R ¹² and R ¹³ and / or R ¹⁴ and R ¹⁵ are the same or different and are, for example, an alkyl group, an aryl group, a cycloalkyl group, or an aralkyl group. R ¹² and R ¹³ , and / or R ¹⁴ and R ¹⁵ may be bonded to each other to form a ring with or without a heteroatom. X is 1-4. Specific examples of thiuram compounds include tetramethylthiuram disulfide, tetramethylthiuram monosulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, dipentamethylenethiuram tetrasulfide and the like.

Examples of the dithiocarbamate accelerator include pentamethylenedithiocarbamate piperidine salt, zinc dimethyldithiocarbamate, copper dimethylcarbamate, and the like.
The above accelerator may be used in a form preliminarily dispersed in an inorganic filler, oil, polymer or the like.

また、上記ＤＢＵの弱酸塩の例としては、炭酸塩、カルボン酸塩、フェーノール性物質との塩、エノール性物質との塩、チオール類との塩等が挙げられる。これら塩を構成する物質を例示すれば、炭酸、酢酸、ギ酸、ソルビン酸、サルチル酸、β−オキシナフトエ酸、フェノール、フタル酸、シアヌル酸、メルカプトベンゾチアゾール、メルカプトベンゾイミダゾールおよびフェノール樹脂、フェノールノボラック樹脂等を挙げることができる。 また上記ＤＢＵを、可塑剤、高級アルコール、グリコール等の液状物質に溶解させて使用することおよび、無機充填剤等に分散させ粉末状態で使用することおよび、高分子物質に練り込んでシート状、ペレット状にして使用することも可能である。 1,8-diazabicyclo (5,4,0) undecene-7 (hereinafter referred to as DBU) is represented by the following formula (7)
It is a compound represented by these.

Examples of the weak acid salt of DBU include carbonates, carboxylates, salts with phenolic substances, salts with enolic substances, salts with thiols, and the like. Examples of substances constituting these salts include carbonic acid, acetic acid, formic acid, sorbic acid, salicylic acid, β-oxynaphthoic acid, phenol, phthalic acid, cyanuric acid, mercaptobenzothiazole, mercaptobenzimidazole and phenol resin, phenol novolac. Examples thereof include resins. Further, the DBU is used by dissolving in a liquid material such as a plasticizer, higher alcohol, glycol, etc., dispersed in an inorganic filler or the like and used in a powder state, and kneaded into a polymer material to form a sheet, It can also be used in the form of pellets.

上記式（８）において、Ｒ¹⁶、Ｒ¹⁷、Ｒ¹⁸、およびＲ¹⁹は互い同一でも異なっていても良く、炭素数１〜１７のアルキル基、シクロヘキシル基、フェニル基、ベンジル基より選ばれる基である。上記炭素数１〜１７のアルキル基の例としては、例えば、メチル基、プロピル基、ブチル基、ヘキシル基、ヘプチル基、オクチル基、デシル基、ドデシル基、ヘキサデシル基等が挙げられる。Ｘは陰イオンであればよい。このような陰イオンの例としては、フッ素、臭素、塩素、ヨウ素等のハロゲンイオン、塩素酸イオン、過塩素酸イオン等のハロゲン酸イオンが挙げられる。本発明で用いられる脂肪酸の例としては、ステアリン酸、オレイン酸、ラウリン酸等が挙げられる。これらの有機加硫促進剤は単独で用いてもよいし、２種類以上の組み合わせて用いてもよい。 The quaternary ammonium compound used in the present invention is a compound represented by the following general formula (8).

In the above formula (8), R ¹⁶ , R ¹⁷ , R ¹⁸ , and R ¹⁹ may be the same or different from each other, and are a group selected from an alkyl group having 1 to 17 carbon atoms, a cyclohexyl group, a phenyl group, and a benzyl group. It is. Examples of the alkyl group having 1 to 17 carbon atoms include a methyl group, a propyl group, a butyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, and a hexadecyl group. X may be an anion. Examples of such anions include halogen ions such as fluorine, bromine, chlorine and iodine, and halogen acid ions such as chlorate ions and perchlorate ions. Examples of fatty acids used in the present invention include stearic acid, oleic acid, lauric acid and the like. These organic vulcanization accelerators may be used alone or in combination of two or more.

  The (f) sulfur donor used in the present invention is a compound that contains sulfur and dissociates and releases this sulfur as active sulfur during the vulcanization reaction. Examples thereof include thiuram polysulfides and morpholine disulfides. It is done. By adding sulfur or a sulfur donor, the vulcanization properties are further improved. (F) The amount of sulfur or sulfur donor used is 0 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the blended rubber of (a) chlorinated polyethylene and (b) nitrile rubber. Preferably it is 0.3-4 weight part.

  The (g) inorganic vulcanization accelerator used in the present invention comprises a basic metal oxide, basic metal salt, basic metal hydroxide, basic silicon dioxide, silicate, and hydrotalcite. Examples include compounds selected from the group. However, it is not limited to these. By adding an inorganic vulcanization accelerator, the physical properties of vulcanization are further improved. (G) The amount of the inorganic vulcanization accelerator used is preferably 0 to 20 parts by weight, more preferably 1 to 5 parts by weight, based on 100 parts by weight of the blend rubber of (a) chlorinated polyethylene and (b) nitrile rubber. It is. Even when added in an amount of 20 parts by weight or more, the effect as an accelerator does not increase, and only the effect as a filler is shown.

  Specific examples thereof include magnesium oxide, calcium oxide, aluminum oxide, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, calcium carbonate, basic silicon dioxide, calcium silicate, and synthetic hydrotalcite. These inorganic basic vulcanization accelerators can be appropriately selected according to other formulations. Basic metal carbonates are preferred for formulations with particular emphasis on storage stability. These inorganic accelerators may be used after surface treatment. Moreover, the said inorganic basic promoter can be used as a filler commonly called in the rubber industry.

  According to the present invention, a blend of nitrile rubber and chlorinated polyethylene is blended with a thiadiazole-based vulcanizing agent and an acid-accepting agent, whereby a vulcanizate having excellent compression set, ozone resistance, and heat resistance is obtained. Obtainable.

Particularly preferred embodiments of the present invention are:
(A) 5 to 95% by weight of chlorinated polyethylene and (b) 95 to 5% by weight of nitrile rubber
To blend rubber consisting of
(C) thiadiazole vulcanizing agent (d) zeolite compound (e) primary, secondary, tertiary amine, organic acid salt of the amine or its adduct, aldehyde amine accelerator, guanidine accelerator, sulfur One or more compounds selected from the group consisting of phenamide accelerators, thiuram accelerators and dithiocarbamic acid accelerators, quaternary ammonium compounds (f) sulfur (g) basic metal oxides, A blend rubber vulcanizing composition comprising a compound selected from the group consisting of basic metal salts, basic metal hydroxides, basic silicon dioxide, silicates, and hydrotalcites. By vulcanizing the blend rubber vulcanizing composition, a vulcanized product having good vulcanization properties can be obtained.

V. This vulcanized composition for vulcanized rubber is vulcanized to obtain a vulcanizate excellent in ozone resistance and compression strain resistance and used for rubber products such as hoses.

  In the composition of the present invention, various compounding agents usually used in the art, such as fillers, reinforcing agents, plasticizers, stabilizers, anti-aging agents, lubricants, viscosity-imparting agents, pigments, flame retardants, ultraviolet absorbers Further, a foaming agent, a vulcanization adjusting agent, and the like can be added. Moreover, a short fiber etc. can also be added for the improvement of intensity | strength and rigidity.

  In order to obtain the composition of the present invention, the above-mentioned blended materials are kneaded using a normal mixing roll, Banbury mixer, twin-screw kneading extruder, various kneaders, etc., and the resulting kneaded material is formed into a sheet shape with an open roll or the like The required shape is as follows. Molding or vulcanization is performed using a press, an extruder, an injection molding machine or the like, and a rubber product having a required shape can be obtained. Vulcanization conditions are suitably selected in the range of several minutes to 2 hours at 100 to 200 ° C.

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 addition, the detail of the compounding material used by the Example and the comparative example is as follows.

・ Chlorinated polyethylene (a): “Daisolac MR104” manufactured by Daiso Corporation, chlorine content 40%
Nitrile rubber (b): “N230S” acrylonitrile content 35%, manufactured by JSR
・ Reinforcing agent: SRF carbon black, manufactured by Tokai Carbon Co., Ltd.
・ Plasticizer: Tri-n-octyl trimellitate, Kao's “Trimex N-08”
・ Lubricant: Sorbitan monostearate ・ Zeolite (d): Synthetic zeolite, A-type zeolite, “Mizcalizer DS” manufactured by Mizusawa Chemical
Magnesia (d): Highly active magnesium oxide, “MgO # 150” manufactured by Kyowa Chemical Co., Ltd.
・ Vulcanizing agent 1: 2,4,6-trimercapto-1,3,5-triazine, “OF-100” manufactured by Daiso Corporation
・ Vulcanizing agent 2 (c): 2,5-dimercapto-1,3,4-thiadiazole ・ Sulfur donor (f): 4,4′-dithiodimorpholine, “Barunok R” manufactured by Ouchi Shinsei Chemical Co., Ltd.
・ Organic vulcanization accelerator 1 (e): n-butyraldehyde / aniline condensate, “Noxeller 8” manufactured by Ouchi Shinsei Chemical Co., Ltd.
・ Organic vulcanization accelerator 2 (e): Dicyclohexylamine salt of 2-mercaptobenzothiazole, “M-181” manufactured by Daiso Corporation
・ Calcium carbonate (g): Shiraishi Kogyo Co., Ltd.
Anti-aging agent: 2,2,4-Limethyl-1,2-hydroquinoline polymer

(Example 1)
As shown in Table 1, 100 parts by weight of a blend of nitrile rubber and chlorinated polyethylene, 59 parts by weight of carbon black as a reinforcing agent, 21 parts by weight of tri-n-octyl trimellitate as a plasticizer, and 10 parts by weight of magnesia as an acid acceptor Parts, 0.6 parts by weight of stearic acid, 2 parts by weight of a lubricant and 1 part by weight of an anti-aging agent were added, and this blend was kneaded at 130 ° C. for 6 minutes. Next, 2 parts by weight of 2,5-dimercapto-1,3,4-thiadiazole as a vulcanizing agent and 1.5 parts by weight of an n-butyraldehyde / aniline condensate as an organic accelerator were added to the kneaded product, and 70-80 It was further kneaded with a roll heated to ° C. to produce a sheet-like rubber composition for vulcanization having a thickness of 2 to 3 mm. This rubber composition was placed in a 15 × 15 cm mold and heated in a press machine at 160 ° C. and 100 kg / cm 2 for 15 minutes to obtain a vulcanizate. A vulcanized product for compression set test was obtained by heating the rubber composition at 160 ° C. and 100 kg / cm 2 for 20 minutes.

(Examples 2 to 13 and Comparative Examples 1 to 3)
Except that the compounding materials were used in the proportions shown in Tables 1 and 3, the same operation as in Example 1 was performed to obtain a sheet-like rubber composition for vulcanization, and further a rubber vulcanizate was obtained. .

(performance test)
In Examples and Comparative Examples, JIS K6300 (unvulcanized rubber physical test method) for the obtained vulcanized composition, and JIS K6251 (tensile test method for vulcanized rubber) for the obtained vulcanized product, JIS K6253 (vulcanized rubber hardness test method), JIS K6262 (vulcanized rubber permanent strain test method), JIS K6259 (vulcanized rubber ozone degradation test method), JIS K6257 (vulcanized rubber aging test method) The physical properties were tested according to the method specified in 1.
The obtained results are shown in Tables 2 and 4.

In the above table, Vm: Mooney scorch time as defined in Mooney scorch test of JIS K6300 Minimum Mooney viscosity t ₅ : Mooney scorch time as defined in Mooney scorch test of JIS K6300
M ₁₀₀ : Tensile stress at 100% elongation as defined in JIS K6251 tensile test
M ₃₀₀ : Tensile stress at 300% elongation as defined in JIS K6251 tensile test
Tb: Tensile strength as defined in JIS K6251 tensile test
Eb: Elongation at break as defined in JIS K6251 tensile test
Hs: Hardness compression set defined in the hardness test of JIS K6253: Compression set (%) defined in the compression set test of JIS K6262.
However, the compression ratio is 25%, and the heat treatment temperature and time are 100 ° C. and 70 hours, respectively.

Ozone resistance test: Evaluated according to the state of cracks defined in the ozone deterioration test of JIS K6259.
The ozone deterioration test was performed under static conditions with an ozone concentration of 50 pphm, a temperature of 40 ° C., and an elongation of 50%.
Evaluation criteria are: number of cracks A: few cracks B: many cracks C: size and depth of innumerable cracks
1: What cannot be seen with the naked eye but can be confirmed with a 10x magnifier
2: What can be confirmed with the naked eye
3: Deep crack and relatively large (crack length less than 1 mm)
4: Deep and large crack (crack length 1 mm or more and less than 3 mm)
5: Cracks or cuts with a length of 3 mm or more are likely to occur. The evaluation results of ozone resistance are expressed as a combination of the number of cracks and the size and depth of the cracks.
NC represents that no crack occurred.

Heat resistance test: According to the air heating aging test of JIS K6257, the temperature and time were 125 ° C. and 70 hours, respectively.
Delta Tb: Rate of change in tensile strength (%) as defined in JIS K6257 air heating aging test
Delta Eb: Rate of change in elongation at break (%) as defined in JIS K6257 air heating aging test
Delta Hs: Change in hardness as defined in the air heating aging test of JIS K6257

As is clear from the above table, Examples 1 to 11, which are blend rubbers of nitrile rubber and chlorinated polyethylene, are smaller in compression set than in Comparative Example 1 and are there any cracks in ozone resistance? In addition, the physical properties are improved in each item, such as the slow rate of change in heat resistance. Further, even when Comparative Examples 2 and 3 and Examples 11 and 12 having different vulcanization systems are compared, the compression set is small, and the physical properties are improved in ozone resistance and heat resistance.

Claims (10)

(A) 5 to 95% by weight of chlorinated polyethylene and (b) 95 to 5% by weight of nitrile rubber
To blend rubber consisting of
(C) A thiadiazole-based vulcanizing agent (d) a metal compound that serves as an acid acceptor (e) an organic vulcanization accelerator, and a blend rubber vulcanizing composition. (A) 5 to 95% by weight of chlorinated polyethylene and (b) 95 to 5% by weight of nitrile rubber
To blend rubber consisting of
(C) A thiadiazole-based vulcanizing agent (d) a metal compound serving as an acid acceptor (e) an organic vulcanization accelerator (f) sulfur or a sulfur donor, and a blend rubber vulcanizing composition characterized by comprising:   The blend rubber vulcanizing composition according to claim 1 or 2, further comprising (g) an inorganic vulcanization accelerator.   The composition for vulcanizing a blend rubber according to any one of claims 1 to 3, wherein the chlorinated polyethylene has a chlorine content of 20 to 50% by weight and does not substantially have heat of crystal melting by DSC method. . The blended rubber vulcanizing composition according to any one of claims 1 to 4, wherein the thiadiazole-based vulcanizing agent is a thiadiazole compound represented by the following general formula (1) or general formula (2).

In formulas (I) and (II), R ¹ And R ² May be the same as or different from each other, and may be a hydrogen atom, a group — (C═O) R 3. Or a group -R4OR5 It is. Here, R3 is an alkyl group having 1 to 17 carbon atoms, an aryl group having one or two rings, an acyl group having 7 to 14 carbon atoms, an aralkyl group having 7 to 8 carbon atoms, or a cyclohexyl group, and R4 is A C1-C8 alkylene group and R5 are C1-C8 alkyl groups.   Thiadiazole-based vulcanizing agents include 2,5-dimercapto-1,3,4 thiadiazole, monobenzoate derivatives of 2,5-dimercapto-1,3,4 thiadiazole and 2,5-dimercapto-1,3,4 thiadiazole The blend rubber vulcanizing composition according to claim 5, which is a compound selected from the group consisting of dibenzoate derivatives.   The blend rubber vulcanizing composition according to any one of claims 1 to 3, wherein the metal compound serving as the acid acceptor is a zeolitic compound.   Organic vulcanization accelerator is primary, secondary, tertiary amine, organic acid salt or adduct of the amine, aldehyde ammonia accelerator, aldehyde amine accelerator, guanidine accelerator, thiazole accelerator, sulfur Selected from the group consisting of phenamide accelerators, thiuram accelerators and dithiocarbamic acid accelerators, 1,8-diazabicyclo (5,4,0) undecene-7 and its weak acid salts, quaternary ammonium compounds and fatty acids The blend rubber vulcanizing composition according to any one of claims 1 to 3, which is one or more organic vulcanization accelerators.   2. The inorganic vulcanization accelerator is a compound selected from the group consisting of basic metal oxides, basic metal salts, basic metal hydroxides, basic silicon dioxide, silicates and hydrotalcites. A composition for vulcanizing a blend rubber according to any one of -3.   A blend rubber vulcanizate obtained by vulcanizing the composition for vulcanizing a blend rubber according to any one of claims 1 to 9.