JP5431666B2 - Hydrin rubber composition - Google Patents

Description

  The present invention relates to a hydrin rubber composition used for forming various hoses, for example, an air hose for automobiles and an outer surface layer of a fuel hose.

Conventionally, materials for forming hoses that require heat resistance, such as automotive air hoses, include epichlorohydrin polymer rubber (CO), epichlorohydrin-ethylene oxide copolymer rubber (ECO), and epichlorohydrin-ethylene oxide. A hydrin rubber composition mainly composed of an allyl glycidyl ether copolymer rubber (GECO) is widely used. In the hydrin rubber composition, a nickel compound such as nickel dibutyldithiocarbamate (NBC) is usually used as an anti-aging agent (refer to Patent Document 1). However, the development of alternative technologies to replace the use of the above nickel compounds has not been carried out so far, and since there is a concern that the above nickel compounds can become so-called environmentally hazardous substances, it has become a viewpoint of environmental problems in recent years. Therefore, a hydrin rubber composition not containing the nickel compound has been studied.
Japanese Patent Laid-Open No. 5-230288

  However, the hose formed using the hydrin rubber composition containing no nickel compound has extremely low heat aging resistance, ozone resistance (particularly dynamic ozone resistance) and the like, and is not completely satisfactory. Although the mechanism for causing such a failure is not clearly understood, the absence of a nickel compound makes it easier for the chlorine at the crosslinking point of the hydrin rubber to be extracted, thereby generating hydrochloric acid in the system. Increasing the use of ordinary acid acceptors (magnesium oxide, calcium carbonate, etc.) in normal amounts results in insufficient acid accepting action. Therefore, during the heat aging test on the hydrin rubber layer, etc., the ether part is easily cleaved mainly by the reaction to the hydrin rubber main chain by hydrochloric acid generated due to the lack of acid accepting action, and as a result, the above phenomenon Is considered to occur.

  For this reason, the use of a nickel-free anti-aging agent that can provide rubber properties equivalent to those obtained using the nickel compound has been studied, but a hydrin rubber composition that is still in practical use has been developed. The actual situation is not obtained.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a hydrin rubber composition that is nickel-free and excellent in heat aging resistance, ozone resistance, storage stability, and the like.

In order to achieve the above object, the hydrin rubber composition of the present invention comprises the following (A) to (E) as essential components, and 0.5 parts by weight of component (B) with respect to 100 parts by weight of component (A). Part to 3 parts by weight, component (C) 0.5 to 3 parts by weight, component (D) 0.5 to 3 parts by weight, component (E) 1 to 15 parts by weight The composition is contained at a ratio of less than part .
(A) A hydrin rubber having an ethylene oxide content of 10 to 40 mol%.
(B) Amine-based anti-aging agent.
(C) A phenolic anti-aging agent.
(D) At least one dithiocarbamate-based antiaging agent selected from the group consisting of zinc dibutyldithiocarbamate, zinc dimethyldithiocarbamate and zinc diethyldithiocarbamate .
(E) A hydrous hydrotalcite compound.

That is, the present inventors have intensively studied in order to obtain a hydrin rubber composition that does not contain nickel and has rubber properties equivalent to those of conventional ones. Further, in place of the conventional nickel compound, further research was conducted in search of a compound that can be an anti-aging agent that does not contain nickel and can obtain the same level of characteristics with respect to heat aging resistance and the like. As a result, when the amine-based anti-aging agent (component B), the phenol-based anti-aging agent (component C), and the specific dithiocarbamic acid- based anti-aging agent (component D) are used in combination, the hydrin rubber is not softened and deteriorated. It has been found that it is extremely effective in improving heat aging resistance, ozone resistance and the like. And the ethylene oxide amount of the hydrin rubber is set to 10 to 40 mol%, the ether part of the hydrin rubber main chain to be attacked by hydrochloric acid generated in the system is reduced, and the BD components are used together. By containing a hydrous hydrotalcite compound that exhibits an excellent acid accepting effect, by blocking the action of radicals that cleave the hydrin rubber main chain (radicals generated by attacking the ether part of the hydrin rubber main chain by hydrochloric acid) The inventors have found that the intended purpose can be achieved and have reached the present invention.

Thus, the hydrin rubber composition of the present invention is composed of 10-40 mol% hydrin rubber (A component), amine-based anti-aging agent (B component), phenol-based anti-aging agent (C component), It contains a specific dithiocarbamic acid anti-aging agent (component D) free of nickel and a hydrous hydrotalcite compound (component E) in a specific ratio . In this way, because it uses an anti-aging compound that does not contain nickel, which is an environmentally hazardous substance, it is superior to environmental problems and has excellent heat aging resistance, ozone resistance, storage stability, workability, etc. Performance can be demonstrated.

  Further, when a coagent having a double bond is added to the hydrin rubber composition, more excellent ozone resistance can be obtained.

  Next, embodiments of the present invention will be described in detail.

As described above, the hydrin rubber composition of the present invention comprises the following (A) to (E) as essential components, and 0.5 parts by weight of component (B) with respect to 100 parts by weight of component (A). More than 3 parts by weight, (C) component 0.5 parts by weight or more and less than 3 parts by weight, (D) component 0.5 parts by weight or more and less than 3 parts by weight, and (E) component 1 part by weight or more and 15 parts by weight or more. It is a rubber composition contained in a proportion of less than .
(A) A hydrin rubber having an ethylene oxide content of 10 to 40 mol%.
(B) Amine-based anti-aging agent.
(C) A phenolic anti-aging agent.
(D) At least one dithiocarbamate-based antiaging agent selected from the group consisting of zinc dibutyldithiocarbamate, zinc dimethyldithiocarbamate and zinc diethyldithiocarbamate .
(E) A hydrous hydrotalcite compound.

  It is necessary to use a hydrin rubber having the component (A) having an ethylene oxide content of 10 to 40 mol%. That is, when the amount of ethylene oxide is less than 10 mol%, a decrease in heat aging resistance is observed. Conversely, when the amount of ethylene oxide exceeds 40 mol%, a decrease in ozone resistance is observed. Because. In addition, when using 2 or more types of hydrin rubbers together as the hydrin rubber of the component (A), “the hydrin rubber having an ethylene oxide amount of 10 to 40 mol%” means that the total ethylene oxide amount is 10 to 40 mol%. It means to use. The hydrin rubber is not particularly limited as long as it satisfies the above regulations. For example, epichlorohydrin polymer rubber (CO), epichlorohydrin-ethylene oxide copolymer rubber (ECO), epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber (GECO) or the like is used alone or in combination of two or more. Among these hydrin rubbers, it is preferable that an epichlorohydrin component is contained at least 50 mol% of the whole, particularly from the viewpoint of heat resistance and the like.

  Examples of the amine-based antioxidant for the component (B) include N-phenyl-N′-isopropyl-p-phenylenediamine and N-phenyl-N ′-(1,3-dimethylbutyl) -p-phenylenediamine. N-phenyl-N ′-(1-methylheptyl) -p-phenylenediamine, N-phenyl-N ′-(3-methacryloyloxy-2-hydroxypropyl) -p-phenylenediamine, phenyl-α-naphthylamine, Alkylated diphenylamine, octylated diphenylamine, 4,4-bis (α, α-dimethylbenzyl) diphenylamine, derivatives of phenothiazine, p- (p-toluenesulfonylamido) diphenylamine, N, N′-di-2-naphthyl-p -With phenylenediamine, N, N-diphenyl-p-phenylenediamine, etc. Aromatic secondary amine antioxidants, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, An amine-ketone type antioxidant such as a reaction product of amine and acetone, a reaction product of diphenylamine and acetone, or the like can be used. These may be used alone or in combination of two or more. Specific examples of such an anti-aging agent include non-flex DCD manufactured by Seiko Chemical Co., Ltd.

And the content rate of the amine type antioxidant of the said (B) component is 0.5 parts or more and less than 3 parts with respect to 100 weight part (henceforth "part") of the hydrin rubber of the said (A) component. to be set within the range. That is, if the content of the amine-based antioxidant is less than 0.5 part, the effect of improving heat resistance and the like is poor, and conversely if it is 3 parts or more, the amine reacts with the ether part of the hydrin rubber main chain. This is because the main chain may be cut to cause softening deterioration.

  Examples of the phenolic antioxidant for the component (C) include styrenated phenol, 2,6-di-tert-butyl-4-methylphenol, 3,5-di-tert-butyl-4-hydroxytoluene, 2,6-di-tert-butyl-p-cresol, 2,2'-dihydroxy-3,3'-di (α-methylcyclohexyl) -5,5'-dimethyldiphenylmethane, 2,2'-methylene-bis [6- (1-methylcyclohexyl-p-cresol)], 4,4'-thio-bis (3-methyl-6-tert-butylphenol), 4,4'-butylidene-bis (3-methyl-6- tert-butylphenol), 2,5-di-tert-butyl-hydroquinone, 2,2'-methylene-bis (4-methyl-6-tert-butylphenol) 2,2'-methylene - bis (4-ethyl -6-tert-butylphenol) and the like. These may be used either alone or in combination. Specific examples of such an anti-aging agent include BHT Swanox manufactured by Seiko Chemical Co., Ltd. and Nonflex MBP manufactured by Seiko Chemical Co., Ltd.

The content of the phenolic antioxidant of component (C), relative hydrin rubber 100 parts of component (A) to set within a range of less than 3 parts 0.5 parts. That is, when the content of the phenolic anti-aging agent is less than 0.5 parts, the effect of improving ozone resistance and the like is poor, and conversely, when it is 3 parts or more, the effect of improving heat resistance by increasing the amount is greatly observed. In addition, the anti-aging agent tends to bloom on the surface, which may impair the appearance.

The dithiocarbamate antioxidant of the component (D) is used is one that does not contain nickel which is an environmental load substance, zinc di thiocarbamate, such as zinc dibutyl dithiocarbamate, zinc dimethyl dithiocarbamate, Zinc diethyldithiocarbamate is used . These may be used alone or in combination of two or more. That is , the specific zinc dithiocarbamate is preferably used from the viewpoint of ozone resistance and compression set.

Further, the content of a particular zinc dithiocarbamates of the component (D), relative to hydrin rubber 100 parts of component (A) to set within a range of less than 3 parts 0.5 parts. That is, when the content ratio of the zinc dithiocarbamate is less than 0.5 part, the scorch property is deteriorated, and when it is 3 parts or more, the compression set property is deteriorated.

Examples of the hydrous hydrotalcite compound as the component (E) 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. these may be used either alone or in combination . Examples of commercially available products include DHT-4A manufactured by Kyowa Chemical Industry Co., Ltd. and DHT-6 manufactured by Kyowa Chemical Industry Co., Ltd.

The content of the above-mentioned water-containing hydrotalcite compound (E), to the hydrin rubber 100 parts of component (A) to set within a range of less than 15 parts or more 1 part. That is, if the hydrous hydrotalcite compound (E) is less than 1 part, the content is too small to obtain the desired acid-accepting effect and the compression set deteriorates. Conversely, if it exceeds 15 parts. This is because the crosslinking proceeds excessively and adversely affects the physical properties of the rubber.

As described above, the hydrin rubber composition of the present invention contains the above components (A) to (E) as essential components, and if necessary, contains the following component (F) as a co-crosslinking agent. It can also be made. That is, when such a co-crosslinking agent is contained in addition to the components (A) to (E), more excellent ozone resistance can be obtained.
(F) A coagent having a double bond.

  Examples of the co-crosslinking agent for the component (F) include triallyl isocyanurate (TAIC), diallyl phthalate (DAP), trimethylolpropane trimethacrylate, 1,2-polybutadiene, and the like. These co-crosslinking agents may be used alone or in combination of two or more.

  The molecular weight of the co-crosslinking agent of the component (F) is preferably less than 4000 and having one or more double bonds. That is, when the molecular weight of the co-crosslinking agent of the component (F) is 4000 or more, there is a risk of adversely affecting the rubber properties and the like.

  And it is preferable to set the content rate of the co-crosslinking agent of the said (F) component in the range of 1 part or more and less than 10 parts with respect to 100 parts of hydrin rubbers of the said (A) component. That is, it is because excellent ozone resistance can be obtained by incorporating the co-crosslinking agent within this range.

  Moreover, a vulcanizing agent is used in the hydrin rubber composition of the present invention as necessary. Examples of the vulcanizing agent include sulfur, 2,3-dimethylcaptoquinoxaline derivative, 2,4,6-trimercapto-s-triazine, tetramethylthiuram monosulfide (TMTS), tetramethylthiuram disulfide (TMTD), Thiurams such as tetraethylthiuram disulfide (TETD), tetrabutylthiuram disulfide (TBTD), dipentamethylenethiuram tetrasulfide (DPTT), sulfur vulcanizing agents such as 4,4'-dithio-dimorpholine, and alkylphenol-formaldehyde resins Resin vulcanizing agents and the like. These may be used alone or in combination of two or more.

  The blending amount of the vulcanizing agent is preferably in the range of 0.3 to 5 parts, particularly preferably in the range of 0.5 to 3 parts, with respect to 100 parts of the hydrin rubber of the component (A).

  Furthermore, in addition to the above components, the hydrin rubber composition of the present invention, if necessary, an acid acceptor, a vulcanization accelerator, a plasticizer, a filler, a vulcanization retarder, a processing aid, a flame retardant, Other additives such as a scorch inhibitor, a colorant, and a white filler can be appropriately blended.

  The acid acceptor is not particularly limited, and examples thereof include magnesium oxide.

  The vulcanization accelerator is not particularly limited. For example, 1.8-diazabicyclo (5.4.0) undecene-7 (DBU) carboxylate (DBU naphthoate or sorbate), DBU Vulcanization accelerators such as phenol resin salts, thiazole series, sulfenamide series, thiuram series, aldehyde ammonia series, aldehyde amine series, guanidine series, thiourea series, and ethylene dimethacrylate series. These may be used alone or in combination of two or more.

  As the plasticizer, ester synthetic plasticizers and the like can be used. Among them, dioctyl phthalate (DOP), di-n-butyl phthalate (DBP), dioctyl adipate (DOA), dibutyl glycol adipate, dibutyl Examples thereof include carbitol adipate and adipic acid polyester. These may be used alone or in combination of two or more.

  Examples of the filler include carbon black, silicon dioxide, calcium carbonate, talc, and clay. These may be used alone or in combination of two or more.

  Examples of the vulcanization retarder include N- (cyclohexylthio) phthalimide and phthalic anhydride.

  Examples of the processing aid include fatty acids such as stearic acid, oleic acid, and lauric acid, and fatty acid esters.

  Examples of the flame retardant include antimony trioxide, aluminum hydroxide, magnesium hydroxide, and chlorinated paraffin.

  By the way, the hydrin rubber composition of this invention mix | blends a vulcanizing agent and the other additive as needed to each component of said (A)-(E), for example, and uses a Banbury mixer, a kneading roll, etc. And kneading.

  In addition, the production of the hose using the hydrin rubber composition thus obtained is performed as follows in the case of a single layer structure, for example. That is, a hose that is a tubular product can be produced by extruding the hose rubber composition onto a mandrel in a tubular shape. In addition, although the hose of the single layer structure was described above, it is not limited to this, and the rubber layer forming material of the hose having the multilayer structure of two or more layers, for example, the rubber layer forming material of the outermost layer of the multilayer structure may be used. It can be used suitably.

  The hydrin rubber composition of the present invention is used for exhausting various hoses, for example, air hoses for automobiles, more specifically, an air mixture containing gasoline mist and mist of engine oil from the engine and supplying it to the engine for recombustion. Air hose, more specifically, hose forming material for air heat-resistant hose such as supercharger hose, blow-by gas hose, emission control hose, etc., and outermost rubber layer that serves as a jacket for fuel hose Useful as a forming material.

  Next, examples will be described together with comparative examples.

  First, each component was prepared prior to the example.

[Hydrin Rubber A]
ECO (Epichromer C, ethylene oxide amount 51 mol%, manufactured by Daiso Corporation)

[Hydrin Rubber B]
CO (Epichromer H, ethylene oxide amount 0 mol%, manufactured by Daiso Corporation)

[Hydrin Rubber C]
ECO (Epichromer CG, ethylene oxide amount 41 mol%, manufactured by Daiso Corporation)

[Processing aid A]
Stearic acid (Lunac S30, manufactured by Kao Corporation)

[Processing aid B]
Fatty acid ester (Emaster 510P, manufactured by Riken Vitamin)

[Anti-aging agent A]
Nickel dibutyldithiocarbamate (NOCRACK NBC, manufactured by Ouchi Shinsei Chemical Co., Ltd.)

[Anti-aging agent B]
Amine-based anti-aging agent (Nonflex DCD, manufactured by Seiko Chemical Co., Ltd.)

[Anti-aging agent C]
Phenolic anti-aging agent (BHT Swanox, Seiko Chemical Co., Ltd.)

[Anti-aging agent D]
Zinc dibutyldithiocarbamate (Noxeller BZ, manufactured by Ouchi Shinsei Chemical Co., Ltd.)

[Anti-aging agent E]
Sodium dibutyldithiocarbamate (Noxeller TP, manufactured by Ouchi Shinsei Chemical Co., Ltd.)

[Co-crosslinking agent A]
Triallyl isocyanurate (TAIC) (TAIC-M60, manufactured by Nippon Kasei Co., Ltd.)

[Co-crosslinking agent B]
Diallyl phthalate (DAP) (manufactured by Sumitomo Chemical Co., Ltd.)

[Co-crosslinking agent C]
1,2-polybutadiene (PB-3000, manufactured by Nippon Soda Co., Ltd.)

[Co-crosslinking agent D]
Polybutadiene rubber (Nipol BR-1220, manufactured by Zeon Corporation)

[Acid acceptor A]
Hydrous hydrotalcite (DHT-4A, manufactured by Kyowa Chemical Industry Co., Ltd.)

[Acid acceptor B]
Magnesium oxide (Kyowa Mag # 150, manufactured by Kyowa Chemical Industry Co., Ltd.)

〔carbon〕
SRF grade carbon black (Seast S, manufactured by Tokai Carbon Co., Ltd.)

[Plasticizer]
Adipic acid ether ester plasticizer (Adekasizer RS-107, manufactured by ADEKA)

[Vulcanization accelerator]
Naphthoic acid DBU salt (DA-500, manufactured by Daiso Corporation)

[Vulcanizing agent]
6-methylquinoxaline-2,3 dithiocarbonate (Daisonette XL-21S, manufactured by Daiso Corporation)

[Vulcanization retarder]
N-cyclohexylthiophthalimide (Santguard PVI, manufactured by Monsanto)

[Examples 1-6 , Reference Examples, Comparative Examples 1-7, Conventional Examples]
The above components (excluding the vulcanizing agent and vulcanization retarder) are blended in the proportions shown in Tables 1 and 2 below, mixed using a Banbury mixer, and then the vulcanizing agent and vulcanization retarding agent are added thereto. The hydrin rubber composition was produced by blending at the ratios shown in Tables 1 and 2 below and kneading using a roll.

  Using each hydrin rubber composition thus obtained, various properties were measured and evaluated according to the following methods.

[Unvulcanized properties]
The scorch time (St. 5p) (min) when the viscosity torque value (absolute value) rose 5 points from the minimum Mooney value was measured with a Mooney viscometer manufactured by Toyo Seiki Seisakusho. And what the said scorch time was 10 minutes or more was evaluated as (circle) what was (circle) and less than 10 minutes.

[Normal physical properties]
Using each hydrin rubber composition, an unvulcanized rubber sheet having a thickness of 2 mm was produced by a mixing roll, and this was subjected to press vulcanization at 160 ° C. for 45 minutes to produce a rubber sheet. Subsequently, the rubber sheet was punched out with a JIS No. 5 dumbbell to prepare a vulcanized rubber test piece. And based on JISK6251, the breaking strength (TS) and elongation at break ( _Eb ) were measured. And what satisfy | filled the requirements that breaking strength (TS) is 9 Mpa or more and breaking elongation ( _Eb ) is 300% or more was evaluated as (circle), and the thing which does not satisfy | fill these requirements was evaluated as x.

(Compression set)
The rubber sheet is molded into a shape and size conforming to JIS K 6262 to produce a vulcanized rubber test piece. In accordance with JIS K 6262, compression set is performed under the measurement conditions of a temperature of 125 ° C. and a test time of 72 hours. Was measured. And the thing whose compression set is 50% or less was evaluated as (circle), and the thing exceeding 50% was evaluated as x.

[Heat aging resistance]
The rubber sheet was punched out with a JIS No. 5 dumbbell to produce a vulcanized rubber test piece. It was subjected to a heat aging test after being left for 72 hours in a high-temperature atmosphere at 150 ° C., and its strength at break (TS) and elongation at break (E _b ) in accordance with JIS K 6251 as well as the above physical properties at normal state. And measured. And what satisfy | filled the requirements that breaking strength (TS) is 6 Mpa or more and breaking elongation ( _Eb ) is 100% or more was evaluated as (circle), and what did not satisfy | fill these requirements was evaluated as x.

[Dynamic ozone resistance]
The vulcanized rubber test piece produced from the rubber sheet was repeatedly stretched by 0 to 30% in an atmosphere with an ozone concentration of 50 pphm and 40 ° C. in accordance with JIS K6259 to evaluate ozone resistance (test time: 168 hours). ) And in the said test, in the test time, what did not produce a crack in a test piece evaluated as (circle), and what produced the crack was evaluated as x.

  These measurement and evaluation results are shown in Tables 3 to 4 below together with the amount of ethylene oxide (mol%) in the hydrin rubber polymer and the presence / absence of Ni. In addition, the “overall determination” described in the table is determined based on the measurement / evaluation results of the various characteristics described above, and does not contain nickel. The others were marked with “x”.

From the above results, the example product is a nickel-free rubber composition, but as in the conventional example using nickel dibutyldithiocarbamate (anti-aging agent A), it is excellent in heat aging resistance and dynamic ozone resistance, and Good results were also obtained in compression set, unvulcanized physical properties, and normal physical properties. When ferric dithiocarbamate, tellurium dithiocarbamate, copper dithiocarbamate or the like is used instead of zinc dithiocarbamate used in the example product, it is inferior to the above example product in terms of compression set or the like. the result is obtained that has been confirmed by experiments.

  On the other hand, the comparative example 1 product in which the amount of ethylene oxide in the polymer is too large has a low breaking point strength (TS) after heat aging, and heat resistance is deteriorated. On the contrary, the comparative example 2 product in which the amount of ethylene oxide in the polymer is too small was inferior in dynamic ozone resistance. In addition, the three products of Comparative Examples which do not contain an amine-based anti-aging agent did not have the desired dynamic ozone resistance. In addition, Comparative Example 4 which does not contain a phenolic anti-aging agent is inferior in normal state physical properties, compression set, etc., and Comparative Example 5 which does not contain a metal salt of dithiocarbamate has unvulcanized physical properties and dynamics. The ozone resistance performance was poor. The products of Comparative Example 6 containing no hydrotalcite were inferior in unvulcanized physical properties and dynamic ozone resistance. The product of Comparative Example 7 containing a coagent having a molecular weight of 4000 or more was inferior in unvulcanized physical properties and normal physical properties.

  In addition, the hose obtained by extruding the hydrin rubber composition of the above example product into a tube is useful as an air-based hose for circulating an air mixture containing gasoline vapor and engine oil mist. It was confirmed by experiment and it was confirmed that even when nickel compounds such as nickel dibutyldithiocarbamate are not contained, it is excellent in heat aging resistance, ozone resistance and the like.

  The hydrin rubber composition of the present invention is used for exhausting various hoses, for example, air hoses for automobiles, more specifically, an air mixture containing gasoline mist and mist of engine oil from the engine and supplying it to the engine for recombustion. It is useful as a material for forming the outermost layer of the air-type hose and the fuel-type hose.

Claims (4)

The following (A) to (E) are essential components, and with respect to 100 parts by weight of component (A), 0.5 parts by weight or more and less than 3 parts by weight of component (B), and 0.5 parts by weight of component (C) A hydrin rubber composition containing at least 0.5 parts by weight and less than 3 parts by weight, (D) component at 0.5 parts by weight and less than 3 parts by weight, and (E) component at 1 part by weight and less than 15 parts by weight . .
(A) A hydrin rubber having an ethylene oxide content of 10 to 40 mol%.
(B) Amine-based anti-aging agent.
(C) A phenolic anti-aging agent.
(D) At least one dithiocarbamate-based antiaging agent selected from the group consisting of zinc dibutyldithiocarbamate, zinc dimethyldithiocarbamate and zinc diethyldithiocarbamate .
(E) A hydrous hydrotalcite compound. The addition to (A) ~ (E) component, according to claim 1 Symbol placement of hydrin rubber composition containing component (F) below.
(F) A coagent having a double bond. The hydrin rubber composition according to claim 2 , wherein the component (F) has a low molecular weight of less than 4000 and has one or more double bonds. The hydrin rubber composition according to claim 2 or 3 , wherein a content ratio of the component (F) is set in a range of 1 part by weight or more and less than 10 parts by weight with respect to 100 parts by weight of the component (A).