JP5482385B2 - Nitrile copolymer rubber composition - Google Patents

Description

  The present invention relates to a nitrile copolymer rubber composition that provides a rubber cross-linked product excellent in gasoline permeation resistance, cold resistance, and ozone resistance.

  Conventionally, a rubber (nitrile copolymer rubber) containing an α, β-ethylenically unsaturated nitrile monomer unit and a conjugated diene monomer unit or an olefin monomer unit is a rubber excellent in oil resistance. The crosslinked product is mainly used as a material for rubber products around various oils for automobiles such as fuel hoses, gaskets, packings and oil seals.

  On the other hand, in recent years, efforts to reduce the transpiration of fuels such as gasoline into the atmosphere have progressed due to increasing global environmental protection activities, and even in Japan, gasoline permeation resistance has been further improved in applications such as fuel hoses, seals and packing. It is required to be excellent and ozone resistant.

  In contrast, Patent Document 1 discloses an α, β-ethylenically unsaturated nitrile monomer as a nitrile copolymer rubber composition that provides a crosslinked product with improved gasoline permeation resistance, ozone resistance and cold resistance. 10 to 100 parts by weight of acrylic resin or vinyl chloride resin, 5 to 500 parts by weight of filler, 0.1 to 200 parts by weight of plasticizer, and 100 parts by weight of nitrile copolymer rubber having a unit of 55 to 80% by weight A nitrile copolymer rubber composition containing a vulcanizing agent has been proposed. According to Patent Document 1, although a crosslinked product of nitrile copolymer rubber excellent in ozone resistance can be obtained, further improvement in gasoline permeability resistance and cold resistance has been desired.

JP 2007-277341 A

  The present invention has been made in view of such circumstances, and provides a nitrile copolymer rubber composition that provides a rubber cross-linked product excellent in gasoline permeation resistance, cold resistance, and ozone resistance, and the nitrile copolymer rubber composition An object of the present invention is to provide a rubber cross-linked product obtained by cross-linking.

  As a result of intensive studies to achieve the above object, the present inventors have determined that α, β-ethylenically unsaturated nitrile monomer units, aromatic vinyl monomer units, and conjugated diene monomer units have a predetermined ratio. A nitrile copolymer rubber having a methyl ethyl ketone insoluble content of 20 to 90% by weight, a predetermined amount of vinyl chloride resin and / or acrylic resin, and a plasticizer having a specific SP value. The nitrile copolymer rubber composition to be found has found that the above object can be achieved, and the present invention has been completed.

That is, according to the present invention, the α, β-ethylenically unsaturated nitrile monomer unit (a1) 30 to 65 % by weight, the aromatic vinyl monomer unit (a2) 5 to 40 % by weight, and the conjugated diene unit The monomer unit (a3) has 25 to 60 % by weight, and the total of the α, β-ethylenically unsaturated nitrile monomer unit (a1) and the aromatic vinyl monomer unit (a2) is 40 to At least one thermoplastic resin (B) selected from the group consisting of 75% by weight nitrile copolymer rubber (A) having a methylethylketone insoluble content of 20 to 90% by weight, and vinyl chloride resin and acrylic resin And a plasticizer (C) having an SP value by the HOY method of 8.0 to 10.2 (cal / cm ³ ) ^1/2 , based on 100 parts by weight of the nitrile copolymer rubber (A) The thermoplastic resin (B) A nitrile copolymer rubber composition having a ratio of 10 to 150 parts by weight and a ratio of the plasticizer (C) of 0.1 to 200 parts by weight is provided.

Preferably, the nitrile copolymer rubber (A) further has a cationic monomer unit and / or a monomer unit (a4) capable of forming a cation, and the nitrile copolymer rubber (A) The content ratio of the cationic monomer unit and / or the monomer unit (a4) capable of forming a cation is 0.1 to 30% by weight.
Preferably, the nitrile copolymer rubber (A) is a hydrogenated nitrile copolymer rubber in which at least a part of the carbon-carbon unsaturated bond portion is hydrogenated.
Preferably, the nitrile copolymer rubber composition of the present invention further contains an inorganic filler (D) having an aspect ratio of 30 to 2,000, and is based on 100 weight of the nitrile copolymer rubber (A). The ratio of the inorganic filler (D) is 1 to 200 parts by weight.

According to the present invention, there is provided a crosslinkable nitrile copolymer rubber composition obtained by adding a crosslinking agent to the nitrile copolymer rubber composition.
According to the present invention, there is provided a crosslinked rubber product obtained by crosslinking the crosslinkable nitrile copolymer rubber composition.

Moreover, according to this invention, the laminated body which consists of two or more layers and at least 1 layer is comprised from the said rubber crosslinked material is provided.
Furthermore, according to this invention, the hose obtained by bridge | crosslinking the molded object obtained by shape | molding the said crosslinkable nitrile copolymer rubber composition into a cylinder shape and inserting a mandrel is provided. The hose of the present invention preferably crosslinks a molded product obtained by forming a laminate of two or more layers including a layer made of the crosslinkable nitrile copolymer rubber composition into a cylindrical shape and inserting a mandrel. Is obtained.

  According to the present invention, a nitrile copolymer rubber composition that gives a rubber cross-linked product excellent in gasoline permeation resistance, cold resistance, and ozone resistance, and obtained by cross-linking the composition, has the above characteristics. A rubber cross-linked product is provided.

Nitrile copolymer rubber composition The nitrile copolymer rubber composition of the present invention comprises at least one heat selected from the group consisting of a specific nitrile copolymer rubber (A) described later, a vinyl chloride resin and an acrylic resin. Containing a plastic resin (B) and a plasticizer (C) having an SP value of 8.0 to 10.2 (cal / cm ³ ) ^1/2 according to the HOY method, the nitrile copolymer rubber (A ) A nitrile copolymer rubber composition in which the ratio of the thermoplastic resin (B) to 100 parts by weight is 10 to 150 parts by weight, and the ratio of the plasticizer (C) is 0.1 to 200 parts by weight.

Nitrile copolymer rubber (A)
First, the nitrile copolymer rubber (A) used in the present invention will be described.
The nitrile copolymer rubber (A) used in the present invention comprises 30 to 70% by weight of α, β-ethylenically unsaturated nitrile monomer unit (a1) and 5 to 50% by weight of aromatic vinyl monomer unit (a2). %, And 15 to 65% by weight of the conjugated diene monomer unit (a3), the α, β-ethylenically unsaturated nitrile monomer unit (a1) and the aromatic vinyl monomer unit (a2) Is a rubber having a methylethylketone insoluble content of 20 to 90% by weight.

  The content ratio of the α, β-ethylenically unsaturated nitrile monomer unit (a1) is 30 to 70% by weight, preferably 30 to 65% by weight, more preferably 35%, based on the total monomer units. ~ 60% by weight. If the content ratio of the α, β-ethylenically unsaturated nitrile monomer unit (a1) is too low, the oil resistance and gasoline permeability resistance of the resulting rubber cross-linked product are deteriorated. On the other hand, if the content is too high, the resulting rubber cross-linked product is inferior in cold resistance, and the embrittlement temperature is increased.

  The α, β-ethylenically unsaturated nitrile monomer forming the α, β-ethylenically unsaturated nitrile monomer unit (a1) may be any α, β-ethylenically unsaturated compound having a nitrile group. Although not particularly limited, for example, acrylonitrile; α-halogenoacrylonitrile such as α-chloroacrylonitrile and α-bromoacrylonitrile; α-alkylacrylonitrile such as methacrylonitrile; Among these, acrylonitrile and methacrylonitrile are preferable. These can be used individually by 1 type or in combination of multiple types.

  The content of the aromatic vinyl monomer unit (a2) is 5 to 50% by weight, preferably 7 to 40% by weight, more preferably 9 to 30% by weight, based on all monomer units. . If the content ratio of the aromatic vinyl monomer unit (a2) is too low, the gasoline permeability resistance of the resulting rubber cross-linked product is deteriorated. On the other hand, if the content is too high, the resulting rubber cross-linked product is inferior in cold resistance, and the embrittlement temperature is increased.

  As the aromatic vinyl monomer forming the aromatic vinyl monomer unit (a2), those having 8 to 16 carbon atoms are preferable, and styrene, α-methylstyrene, monochlorostyrene, dichlorostyrene, trichlorostyrene, monomethylstyrene. Dimethyl styrene, trimethyl styrene, hydroxymethyl styrene, methoxy styrene, chloromethyl styrene, phenyl styrene, vinyl naphthalene and the like. Of these, styrene is preferred. These can be used individually by 1 type or in combination of multiple types.

  The content rate of a conjugated diene monomer unit (a3) is 15 to 65 weight% with respect to all the monomer units, Preferably it is 25 to 60 weight%, More preferably, it is 30 to 55 weight%. If the content ratio of the conjugated diene monomer unit (a3) is too low, the rubber elasticity of the resulting rubber cross-linked product is lowered. On the other hand, if the content ratio is too high, the heat aging resistance and chemical stability of the resulting rubber cross-linked product may be impaired.

  The conjugated diene monomer forming the conjugated diene monomer unit (a3) is preferably a conjugated diene having 4 or more carbon atoms, such as 1,3-butadiene, isoprene, 2,3-dimethyl-1,3- Examples thereof include butadiene and 1,3-pentadiene. Of these, 1,3-butadiene is preferred. These can be used individually by 1 type or in combination of multiple types.

  The nitrile copolymer rubber (A) used in the present invention is the total content of the α, β-ethylenically unsaturated nitrile monomer unit (a1) and the aromatic vinyl monomer unit (a2). Is 40 to 75% by weight, preferably 45 to 75% by weight. If the total content of these is too low, the gasoline permeation resistance of the resulting rubber cross-linked product will deteriorate. On the other hand, if the total content of these is too high, the resulting rubber cross-linked product will be inferior in cold resistance and the embrittlement temperature will be high.

  Further, the nitrile copolymer rubber (A) used in the present invention comprises an α, β-ethylenically unsaturated nitrile monomer unit (a1), an aromatic vinyl monomer unit (a2), and a conjugated diene monomer. In addition to the unit (a3), it is preferable to further have a cationic monomer unit and / or a monomer unit (a4) capable of forming a cation.

  The content ratio of the cationic monomer unit and / or the monomer unit (a4) capable of forming a cation is preferably 0 to 30% by weight, more preferably 0. 1 to 30% by weight, more preferably 0.3 to 10% by weight. By containing the cationic monomer unit and / or the monomer unit (a4) capable of forming a cation, the obtained rubber cross-linked product can be made more excellent in oil resistance.

  As the monomer that forms the cationic monomer unit and / or the monomer unit (a4) capable of forming a cation, the polymer obtained is positively charged when in contact with water or an aqueous acid solution. The monomer is not particularly limited as long as it is a monomer that forms a monomer unit. Examples of such a monomer include a monomer containing a quaternary ammonium base as a cationic monomer. Moreover, as a monomer capable of forming a cation, it is cationized to an ammonium salt (for example, amine hydrochloride or amine sulfate) when coming into contact with an aqueous acid solution such as hydrochloric acid and sulfuric acid such as a tertiary amino group. And a monomer having a precursor portion (substituent).

  Specific examples of the cationic monomer include (meth) acryloyloxytrimethylammonium chloride [acryloyloxytrimethylammonium chloride and / or methacryloyloxytrimethylammonium chloride. The same applies hereinafter. Quaternary ammonium bases such as (meth) acryloyloxyhydroxypropyltrimethylammonium chloride, (meth) acryloyloxytriethylammonium chloride, (meth) acryloyloxydimethylbenzylammonium chloride, (meth) acryloyloxytrimethylammonium methyl sulfate (Meth) acrylic acid ester monomers; (meth) acrylamidopropyltrimethylammonium chloride, (meth) acrylamidepropyldimethylbenzylammonium chloride and other (meth) acrylamide monomers containing quaternary ammonium bases; It is done.

Specific examples of monomers capable of forming cations include vinyl group-containing cyclic amine monomers such as 2-vinylpyridine and 4-vinylpyridine; tertiary amino groups such as dimethylaminoethyl (meth) acrylate (Meth) acrylic acid ester monomer; tertiary amino group-containing (meth) acrylamide monomer such as (meth) acrylamide dimethylaminoethyl, N, N-dimethylaminopropylacrylamide; N- (4-anilinophenyl) ) Acrylamide, N- (4-anilinophenyl) methacrylamide, N- (4-anilinophenyl) cinnamamide, N- (4-anilinophenyl) crotonamide, N-phenyl-4- (3-vinylbenzyloxy) ) Aniline, N-phenyl-4- (4-vinylbenzyloxy) aniline and the like.
These can be used individually by 1 type or in combination of multiple types.

Among cationic monomers and monomers capable of forming cations, vinyl group-containing cyclic amine monomers, tertiary amino group-containing (meth) acrylic acid ester monomers, and tertiary amino group-containing ( A meta) acrylamide monomer is preferable, a vinyl group-containing cyclic amine monomer and a tertiary amino group-containing acrylamide monomer are more preferable, and a vinyl group-containing cyclic amine monomer is particularly preferable.
In addition, as a vinyl group containing cyclic amine monomer, vinyl group containing pyridines are preferable and 2-vinyl pyridine is especially preferable.

  Furthermore, the nitrile copolymer rubber (A) used in the present invention comprises the above α, β-ethylenically unsaturated nitrile monomer unit (a1), aromatic vinyl monomer unit (a2), conjugated diene monomer. In addition to the unit (a3) and the monomer unit (a4) capable of forming a cationic monomer unit and / or a cation, other units copolymerizable with the monomer forming these monomer units It may contain monomer units. The content ratio of such other monomer units is preferably 30% by weight or less, more preferably 20% by weight or less, and still more preferably 10% by weight or less based on the total monomer units.

  Examples of such other copolymerizable monomers include fluorine-containing vinyl compounds such as fluoroethyl vinyl ether, fluoropropyl vinyl ether, o-trifluoromethylstyrene, vinyl pentafluorobenzoate, difluoroethylene, and tetrafluoroethylene. Non-conjugated diene compounds such as 1,4-pentadiene, 1,4-hexadiene, vinylnorbornene, dicyclopentadiene; ethylene; propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, etc. Α-olefin compounds of α, β-ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, fumaric acid, fumaric anhydride and the like; (Meth) methyl acrylate, (meth) acrylic Α, β-ethylenically unsaturated monocarboxylic acid alkyl esters such as ethyl oxalate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate; monoethyl maleate, diethyl maleate, monobutyl maleate, dibutyl maleate Α, β-ethylenic acid such as monoethyl fumarate, diethyl fumarate, monobutyl fumarate, dibutyl fumarate, monocyclohexyl fumarate, dicyclohexyl fumarate, monoethyl itaconate, diethyl itaconate, monobutyl itaconate, dibutyl itaconate Monoesters and diesters of saturated polycarboxylic acids; alkoxyalkyls of α, β-ethylenically unsaturated carboxylic acids such as methoxyethyl (meth) acrylate, methoxypropyl (meth) acrylate, butoxyethyl (meth) acrylate Ester; 2-hydroxyethyl (meth) acrylate, (meth) alpha, such as acrylic acid 3-hydroxypropyl, hydroxyalkyl esters of β- ethylenically unsaturated carboxylic acids; and the like.

  The nitrile copolymer rubber (A) used in the present invention has a methyl ethyl ketone (MEK) insoluble content of 20 to 90% by weight, preferably 25 to 85% by weight, more preferably 30 to 80% by weight. . When there is too little insoluble matter in methyl ethyl ketone, the gasoline permeation resistance of the resulting rubber cross-linked product is lowered. On the other hand, when there is too much insoluble matter in methyl ethyl ketone, the processability of the nitrile copolymer rubber composition is lowered and kneading becomes difficult.

In the present invention, 1 g of nitrile copolymer rubber is immersed in 200 ml of methyl ethyl ketone, left to stand at 23 ° C. for 24 hours, filtered using a 325 mesh wire mesh, and the filtrate is evaporated to dryness. The remaining dry solid content [methyl ethyl ketone soluble content: (y) g] was weighed and calculated by the following formula.
Methyl ethyl ketone insoluble matter (% by weight) = 100 × (1-y) / 1

  In addition, the methylethylketone insoluble content of the nitrile copolymer rubber (A) is the polymerization temperature, reaction time, type and amount of polymerization initiator used when polymerizing the nitrile copolymer rubber (A), and a crosslinkable monomer. It can be controlled by appropriately selecting various factors such as the type of body and the amount of use thereof, and further, the type of molecular weight regulator and the amount of use thereof, and adjusting the degree of crosslinking of the nitrile copolymer rubber (A). Although possible, there is a method in which 0.01 to 5 parts by weight of a crosslinkable monomer such as divinylbenzene or trimethylolpropane tri (meth) acrylate is used with respect to 100 parts by weight of the total monomers. Preferably used.

The Mooney viscosity of the nitrile copolymer rubber (A) (hereinafter sometimes referred to as “polymer Mooney viscosity”) (ML _{1 + 4} , 100 ° C.) is preferably 3 to 250, more preferably 15 to 180, Preferably it is 20-160. If the polymer Mooney viscosity of the nitrile copolymer rubber (A) is too low, the strength characteristics of the resulting rubber cross-linked product may be lowered. On the other hand, if it is too high, the workability may be deteriorated.

  The nitrile copolymer rubber (A) used in the present invention can be produced by copolymerizing each monomer constituting the nitrile copolymer rubber (A). The method for copolymerizing each monomer is not particularly limited. For example, an emulsion polymerization method for obtaining a latex of a copolymer having an average particle diameter of about 50 to 1,000 nm using an emulsifier, polyvinyl alcohol, etc. A suspension polymerization method (including a fine suspension polymerization method) that obtains a latex of a copolymer having an average particle size of about 0.2 to 200 μm using the above dispersant can be suitably used. Among these, the emulsion polymerization method is more preferable because the polymerization reaction can be easily controlled.

The emulsion polymerization method is preferably performed according to the following procedure.
In the following, the α, β-ethylenically unsaturated nitrile monomer is referred to as “monomer (m1)”, the aromatic vinyl monomer is referred to as “monomer (m2)”, and a conjugated diene monomer is appropriately used. The monomer is referred to as “monomer (m3)”, and the monomer capable of forming a cationic monomer and / or cation is referred to as “monomer (m4)”.

  That is, the monomer (m1) is 25 to 80% by weight, preferably 30 to 70% by weight, more preferably 35 to 65% by weight, and the monomer (m2) 5 to 60% by weight, preferably 7 to 50% by weight. More preferably 7 to 35% by weight, monomer (m3) 10 to 70% by weight, preferably 15 to 60% by weight, more preferably 25 to 55% by weight, and monomer (m4) 0 to 30% by weight. %, Preferably 0.2 to 20% by weight, more preferably 0.5 to 10% by weight of monomer mixture (provided that monomer (m1), monomer (m2), monomer (m3 ) And the monomer (m4) is 100% by weight.) Is emulsion polymerized, and when the polymerization conversion rate is preferably 50 to 99% by weight, the polymerization reaction is stopped, A method of removing the monomer of the reaction is preferred.

If the amount of the monomer (m1) used in the emulsion polymerization method is too small, the resulting rubber cross-linked product deteriorates in gasoline permeation resistance and oil resistance. On the other hand, if it is too large, cold resistance tends to deteriorate. is there. If the amount of the monomer (m2) used is too small, the gasoline cross-linkability of the resulting rubber cross-linked product is deteriorated. On the other hand, if the amount is too large, the cold resistance tends to be inferior. If the amount of the monomer (m3) used is too small, the reaction is deactivated at the initial stage of polymerization. On the other hand, if the amount is too large, the gasoline permeation resistance of the resulting rubber cross-linked product tends to deteriorate.
If the polymerization conversion rate for stopping the polymerization reaction is too low, recovery of unreacted monomers becomes very difficult. On the other hand, when too high, there exists a possibility that the normal-state physical property of the rubber crosslinked material obtained may deteriorate.

  In conducting emulsion polymerization, conventionally known emulsifiers, polymerization initiators, polymerization auxiliary materials, and the like can be appropriately used in the field of emulsion polymerization.

  The emulsifier is not particularly limited, and examples thereof include an anionic surfactant, a nonionic surfactant, a cationic surfactant, and an amphoteric surfactant. The amount of the emulsifier used is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 5 parts by weight with respect to 100 parts by weight of the total monomers.

  Although it does not specifically limit as a polymerization initiator, A radical initiator can be used preferably. Examples of such radical initiators include inorganic peroxides such as sodium persulfate, potassium persulfate, ammonium persulfate, potassium perphosphate, and hydrogen peroxide; t-butyl peroxide, cumene hydroperoxide, p- Menthane hydroperoxide, di-t-butyl peroxide, t-butylcumyl peroxide, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, dibenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide , Organic peroxides such as t-butylperoxyisobutyrate; and the like. These polymerization initiators can be used alone or in combination of two or more. The amount of the polymerization initiator used is preferably 0.001 to 3 parts by weight, more preferably 0.002 to 2 parts by weight with respect to 100 parts by weight of the total monomers.

  Although it does not specifically limit as a molecular weight modifier, For example, α-methylstyrene dimer; Mercaptans, such as t-dodecyl mercaptan, n-dodecyl mercaptan, octyl mercaptan; Halogenation, such as carbon tetrachloride, a methylene chloride, a methylene bromide Hydrocarbons; sulfur-containing compounds such as tetraethylthiuram disulfide, dipentamethylene thiuram disulfide, diisopropylxanthogen disulfide; and the like. These can be used alone or in combination of two or more. Although the usage-amount of a molecular weight modifier changes with kinds, Preferably it is 0.001-10 weight part with respect to 100 weight part of all monomers, More preferably, it is 0.01-5 weight part. In the present invention, the amount of insoluble methyl ethyl ketone contained in the nitrile copolymer rubber (A) may be controlled by adjusting the amount of the molecular weight modifier used within the above range. For example, if the amount of molecular weight modifier used is relatively small, the amount of methyl ethyl ketone insoluble matter tends to increase, whereas if the amount of molecular weight modifier used is relatively large, the amount of methyl ethyl ketone insoluble matter tends to increase. The amount tends to decrease.

  In the emulsion polymerization, the reaction temperature is preferably 0 to 90 ° C, more preferably 0 to 50 ° C, and the reaction time is preferably 1 to 50 hours, more preferably 2 to 30 hours. In the present invention, among the reaction conditions, the amount of methyl ethyl ketone insoluble matter contained in the nitrile copolymer rubber (A) may be controlled by adjusting the reaction time within the above range. By making the reaction time relatively long and the polymerization conversion rate relatively high as 60 to 99% by weight, the amount of methyl ethyl ketone insoluble matter tends to increase.

  Furthermore, in the present invention, the polymerization reaction may be started using the total amount of the monomers (m1) to (m4) used for the emulsion polymerization, but the composition distribution of each monomer unit of the copolymer to be produced From the viewpoint of obtaining a crosslinked rubber product rich in rubber elasticity, a polymerization reaction is started using a part of the total amount of monomers (m1) to (m4) used for emulsion polymerization, and then emulsified. It is preferable to polymerize by adding the remainder of the monomers (m1) to (m4) used for the polymerization to the reactor. This is because, generally, if the total amount of the monomers (m1) to (m4) used for the emulsion polymerization is reacted from the start of the polymerization reaction, the composition distribution of the copolymer spreads.

  In this case, the monomer (m1) used for the polymerization is preferably 10 to 100% by weight, more preferably 20 to 100% by weight, particularly preferably 30 to 100% by weight, preferably the monomer (m2) used for the polymerization. Is 5 to 100% by weight, more preferably 10 to 100% by weight, particularly preferably 20 to 100% by weight, preferably 5 to 100% by weight, more preferably 10 to 80% by weight of the monomer (m3) used in the polymerization. %, Particularly preferably 15 to 70% by weight, and preferably 0 to 100% by weight, more preferably 10 to 100% by weight, particularly preferably 20 to 100% by weight of the monomer (m4) used for the polymerization. After the monomer mixture is charged into the reactor and the polymerization reaction is started, the polymerization conversion rate with respect to the monomer mixture charged in the reactor is preferably in the range of 5 to 90% by weight, and the remaining monomer is removed. It is preferred to continue adding to the polymerization reaction to 応器. For example, even when the monomer (m4) is not used, polymerization is performed using the above-mentioned amounts among the monomer (m1), the monomer (m2), and the monomer (m3) used for the polymerization. It is preferable to start the reaction and perform polymerization by adding the remainder of the monomers (m1), (m2), and (m3) to the reactor.

  The method for adding the remaining monomer is not particularly limited, but it may be added all at once, dividedly, or continuously. In the present invention, from the viewpoint that the composition distribution of the copolymer to be obtained can be more easily controlled, it is preferable to add the remaining monomer in divided portions, and it is particularly preferable to add in one to six portions. preferable. When the remaining monomer is added in a divided manner, the amount of monomer to be added in a divided manner and the timing of the divided addition may be adjusted so as to obtain a desired copolymer in accordance with the progress of the polymerization reaction.

  Then, if desired, a latex of the nitrile copolymer rubber (A) is obtained by removing unreacted monomers using a known method such as heating distillation, vacuum distillation, steam distillation or the like.

  In the present invention, the solid content concentration of the latex of the nitrile copolymer rubber (A) obtained by the emulsion polymerization method is preferably 5 to 70% by weight, more preferably 10 to 60% by weight.

  The nitrile copolymer rubber (A) used in the present invention is such that at least a part of the unsaturated bond portion in the conjugated diene monomer unit portion of the copolymer obtained by copolymerization as described above is hydrogen. Hydrogenated nitrile copolymer rubber may be used (hydrogenation reaction). The method for hydrogenation is not particularly limited, and a known method may be employed. When the nitrile copolymer rubber (A) is a hydrogenated nitrile copolymer rubber, the iodine value is preferably in the range of 0 to 70, more preferably in the range of 4 to 60. By hydrogenating the nitrile copolymer rubber (A) to obtain a hydrogenated nitrile copolymer rubber, heat resistance, weather resistance, ozone resistance and the like can be improved.

Thermoplastic resin (B)
The nitrile copolymer rubber composition of the present invention contains at least one thermoplastic resin (B) selected from the group consisting of a vinyl chloride resin and an acrylic resin in addition to the nitrile copolymer rubber (A) described above. To do. By adding the thermoplastic resin (B) to the nitrile copolymer rubber (A), the ozone resistance of the resulting rubber cross-linked product can be improved.

  In the vinyl chloride resin, the main constituent monomer is vinyl chloride, and the content of units of the main constituent monomer is preferably 50 to 100% by weight, more preferably 60 to 100% by weight, and still more preferably 70 to 100%. % By weight. The vinyl chloride resin has an average polymerization degree according to the solution viscosity method specified in JIS K6721 of preferably 400 to 3,000, more preferably 600 to 2,000, and a glass transition temperature (Tg) of preferably 50 to 180 ° C.

The vinyl chloride resin can be produced by conventionally known emulsion polymerization or suspension polymerization.
For example, in the case of producing by emulsion polymerization, a pressure resistant reaction vessel is charged with an emulsifier such as water, sodium lauryl sulfate, and a polymerization initiator such as potassium persulfate, and after repeated degassing under reduced pressure, a vinyl chloride monomer (Other monomers that can be copolymerized may be added if necessary), and the emulsion polymerization is performed by heating while stirring, and a polymerization terminator is added when the polymerization conversion rate reaches a predetermined value. Then, it is cooled to room temperature to remove the unreacted monomer to obtain a vinyl chloride resin latex.

  The acrylic resin is a resin in which the main constituent monomer is a (meth) acrylic acid alkyl ester, and the content of units of the main constituent monomer is preferably 50 to 100% by weight, more preferably 60 to 100% by weight. More preferably, it is 70 to 100% by weight. In addition, the acrylic resin has a standard polystyrene conversion number average molecular weight (Mn) by gel permeation chromatography (GPC), preferably 10,000 to 7,000,000, more preferably 100,000 to 2,000,000. The glass transition temperature (Tg) is preferably 60 to 150 ° C.

The acrylic resin can be produced by conventionally known emulsion polymerization or suspension polymerization.
For example, in the case of production by emulsion polymerization, water, an emulsifier such as sodium octyl sulfate, a polymerization initiator such as ammonium persulfate, a monomer such as methyl methacrylate (others that can be copolymerized if necessary) The monomer may be added) and heated while stirring to carry out emulsion polymerization. When the polymerization conversion rate reaches a predetermined value, a polymerization terminator is added, and the mixture is cooled to room temperature and latex of acrylic resin Can be obtained.

  The content of at least one thermoplastic resin (B) selected from the group consisting of a vinyl chloride resin and an acrylic resin is 10 to 150 parts by weight with respect to 100 parts by weight of the nitrile copolymer rubber (A), Preferably it is 15-130 weight part, More preferably, it is 20-100 weight part. When there is too little content of a thermoplastic resin (B), there exists a possibility that it may be inferior to gasoline permeability resistance and ozone resistance, and when there is too much content, there exists a possibility that cold resistance may deteriorate.

Plasticizer (C)
In addition to the nitrile copolymer rubber (A) and the thermoplastic resin (B), the nitrile copolymer rubber composition of the present invention has an SP value (solubility parameter) by the HOY method of 8.0 to 10.2 (cal / Cm ³ ) ^1/2 plasticizer (C). If the SP value of the plasticizer is too large, the resulting rubber cross-linked product has poor cold resistance. On the other hand, if it is too small, the gasoline permeation resistance of the resulting rubber cross-linked product is deteriorated.

Specific example of plasticizer (C) whose SP value by the HOY method is 8.0 to 10.2 (cal / cm ³ ) ^1/2 (the unit of SP value is “(cal / cm ³ ) ^1/2 ”) As, for example, dibutoxyethyl adipate (SP value: 8.8), di (butoxyethoxyethyl) adipate (SP value: 9.2), di (methoxytetraethylene glycol) adipate, di ( Ester compounds of adipic acid and ether bond-containing alcohols such as methoxypentaethylene glycol) and adipic acid (methoxytetraethylene glycol) (methoxypentaethylene glycol); dibutoxyethyl azelate, di (butoxyethoxyethyl) azelate, etc. Ester compound of azelaic acid and ether bond-containing alcohol; dibutoxye sebacate Ester compound of sebacic acid such as chill, di (butoxyethoxyethyl) sebacate and alcohol containing ether bond; ester of phthalic acid such as dibutoxyethyl phthalate, di (butoxyethoxyethyl) phthalate and alcohol containing ether bond Compound; ester compound of isophthalic acid and ether bond-containing alcohol such as dibutoxyethyl isophthalate and di (butoxyethoxyethyl) isophthalate; di- (2-ethylhexyl) adipate (SP value: 8.5), adipic acid Adipic acid dialkyl esters such as diisodecyl (SP value: 8.3), diisononyl adipate, dibutyl adipate (SP value: 8.9); di- (2-ethylhexyl) azelate (SP value: 8.5) , Diisooctyl azelaate, di-n-azelaate Dialkyl esters of azelaic acid such as xylyl; dialkyl esters of sebacic acid such as di-n-butyl sebacate (SP value: 8.7), di- (2-ethylhexyl) sebacate (SP value: 8.4); Dibutyl phthalate (SP value: 9.4), di- (2-ethylhexyl) phthalate (SP value: 9.0), di-n-octyl phthalate, diisobutyl phthalate, diheptyl phthalate (SP value: 9) 0.0), diisodecyl phthalate (SP value: 8.5), diundecyl phthalate (SP value: 8.5), diisononyl phthalate (SP value: 8.9), and the like; dialkyl phthalates; Phthalic acid dicycloalkyl esters such as diphenyl phthalate and butyl benzyl phthalate (SP value: 10.2) Isophthalic acid dialkyl esters such as di- (2-ethylhexyl) isophthalate and diisooctyl isophthalate; Dialkyl phthalates; trimellitic acid tri- (2-ethylhexyl) (SP value: 8.9), trimellitic acid tri-n-octyl (SP value: 8.9), trimellitic acid triisodecyl (SP value: 8.4), trimellitic acid such as triisooctyl trimellitic acid, tri-n-hexyl trimellitic acid, triisononyl trimellitic acid (SP value: 8.8), triisodecyl trimellitic acid (SP value: 8.8) Acid derivatives; epoxidized soybean oil (SP value: 9.0), Epo And epoxy plasticizers such as xylated linseed oil (SP value: 9.3); and phosphate ester plasticizers such as tricresyl phosphate (SP value: 9.7). These can be used individually by 1 type or in combination of multiple types.

  Among these, since the resulting rubber cross-linked product can have good gasoline permeation resistance and cold resistance, it contains a dibasic acid such as adipic acid, azelaic acid, sebacic acid and phthalic acid, and an ether bond. An ester compound with an alcohol; is preferred, and an ester compound with an adipic acid and an ether bond-containing alcohol is more preferred; adipic acid di (butoxyethoxyethyl), adipic acid di (methoxytetraethylene glycol), adipic acid di (methoxypenta) Ethylene glycol) and adipic acid (methoxytetraethylene glycol) (methoxypentaethylene glycol) are more preferred, and di (butoxyethoxyethyl) adipate is particularly preferred.

  Content of the plasticizer (C) in the nitrile copolymer rubber composition of this invention is 0.1-200 weight part with respect to 100 weight part of nitrile copolymer rubber (A), Preferably it is 1-150. Part by weight, more preferably 2 to 100 parts by weight. When there is too little content of a plasticizer (C), the cold resistance of the rubber crosslinked material obtained will be inferior. On the other hand, if the content is too large, bleeding may occur.

Inorganic filler (D)
The nitrile copolymer rubber composition of the present invention has an aspect ratio of 30 to 2,000 in addition to the nitrile copolymer rubber (A), the thermoplastic resin (B), and the plasticizer (C). It preferably contains a certain inorganic filler (D).

  The inorganic filler (D) is a flat filler having an aspect ratio of 30 to 2,000, and the aspect ratio is preferably 35 to 1,800, more preferably 100 to 1,600, and particularly preferably. 200 to 1,300. By using such a flat inorganic filler (D), the gasoline permeation resistance of the resulting rubber cross-linked product can be further increased. If the aspect ratio is too small, it is difficult to obtain an effect of improving the gasoline permeation resistance. On the other hand, when too large, dispersion | distribution in a nitrile copolymer rubber (A) will become difficult, and mechanical strength will fall.

  In the present invention, the aspect ratio of the inorganic filler (D) can be calculated by determining the ratio of the average surface diameter to the average thickness of the inorganic filler (D). Here, the surface average diameter and the average thickness are the numbers calculated as the arithmetic average value of the surface diameter and thickness of 100 inorganic fillers (D) randomly selected with an atomic force microscope. Average value.

  The inorganic filler (D) having an aspect ratio of 30 to 2,000 is not particularly limited, and it may be derived from a natural product or a natural product subjected to a treatment such as purification. It may be a synthetic product. Specific examples include kaolinites such as kaolinite and halosite; smectites such as montmorillonite, beidellite, nontronite, saponite, hectorite, stevensite, mica; and vermiculites; chlorite; talc; E Examples thereof include glass flakes which are amorphous plate-like particles such as glass or C glass, among which smectites are preferable, and montmorillonite, mica and saponite are particularly preferable. These can be used individually by 1 type or in combination of multiple types. Moreover, in this invention, you may use what isolate | separates each layer which comprises the compound which has a multilayered structure montmorillonite, mica, and saponite by carrying out the water dispersion process of montmorillonite, mica, and saponite. By performing such an aqueous dispersion treatment, a composition having good dispersibility can be obtained. Here, among the above, montmorillonite as the inorganic filler (D) is contained as a main component in bentonite. Therefore, as montmorillonite, one obtained by purifying bentonite or the like may be used. it can.

  The average particle diameter (average primary particle diameter) of the inorganic filler (D) is preferably 0.001 to 20 μm, more preferably 0.005 to 15 μm, and still more preferably 0.01 to 10 μm. In the present invention, the average particle diameter of the inorganic filler (D) is defined as a 50% volume cumulative diameter obtained by measuring the particle size distribution by the X-ray transmission method. If the particle size of the inorganic filler (D) is too small, the elongation of the resulting rubber cross-linked product may be reduced. Conversely, if it is too large, a stable rubber composition may not be prepared.

  The content of the inorganic filler (D) is preferably 1 to 200 parts by weight, more preferably 2 to 150 parts by weight, further preferably 3 to 100 parts by weight with respect to 100 parts by weight of the nitrile copolymer rubber (A). It is. If the amount of the inorganic filler (D) used is too small, the effect of adding the inorganic filler (D) tends to be difficult to obtain. On the other hand, when there is too much usage-amount, there exists a possibility that the elongation of the rubber crosslinked material obtained may fall.

Method for Preparing Nitrile Copolymer Rubber Composition The method for preparing the nitrile copolymer rubber composition of the present invention is not particularly limited, and can be prepared by the following method. That is, first, a latex of the nitrile copolymer rubber (A) is prepared by the above-described method, and then the latex of the thermoplastic resin (B) and the plasticizer (C) are added to the latex of the nitrile copolymer rubber (A). ) And an aqueous dispersion of the inorganic filler (D) added as necessary are added under stirring to obtain a latex composition. And the nitrile copolymer rubber composition of this invention can be prepared by coagulating the obtained latex composition, and washing and drying as needed.

  The method for preparing the aqueous dispersion of the plasticizer (C) is not particularly limited. While strongly stirring the aqueous medium containing the surfactant in an amount of 0.5 to 10% by weight of the plasticizer (C), It is preferable to prepare by adding a plasticizer (C). Such surfactants include anionic surfactants such as potassium rosinate, sodium lauryl sulfate, potassium oleate, sodium dodecylbenzenesulfonate; polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan alkyl. Nonionic surfactants such as esters; cationic surfactants such as didecyldimethylammonium chloride and stearyltrimethylammonium chloride. In addition, it is preferable that the density | concentration of the plasticizer (C) in an aqueous dispersion shall be 5-70 weight%.

  The method for adjusting the aqueous dispersion of the inorganic filler (D) is not particularly limited, but may be prepared by adding the inorganic filler (D) while strongly stirring the aqueous medium. In this case, sodium polyacrylate, sodium tripolyphosphate, sodium hexametaphosphate, sodium pyrophosphate, sodium polymaleate, β-naphthalene in an amount of 0.1 to 10% by weight with respect to the inorganic filler (D). An aqueous medium containing a dispersant such as Na salt of a sulfonic acid / formalin condensate, a surfactant or the like may be used, and an anionic dispersant or surfactant is preferably contained. These can be used individually by 1 type or in combination of multiple types. The solid content concentration of the aqueous dispersion of the inorganic filler (D) is preferably 1 to 50% by weight, more preferably 2 to 40% by weight.

  When preparing the aqueous dispersion of the inorganic filler (D), the inorganic filler (D) may be dispersed in water using a wet pulverizer. When the inorganic filler (D) is secondary agglomerated by dispersing using a wet pulverizer, the secondary agglomeration of the inorganic filler (D) can be eliminated, and the resulting rubber cross-linked product is obtained. Excellent gasoline permeation resistance can be achieved. As the wet pulverizer used in this case, Nasmizer (manufactured by Yoshida Kikai Kogyo Co., Ltd.), Super Wing Mill DM-200 (manufactured by STEC Co., Ltd.), Starburst (manufactured by Sugino Machine Co., Ltd.), Star Mill (Ashizawa Fine) Tech Co., Ltd.).

  Coagulation of the latex composition is not particularly limited, and known methods such as freeze coagulation, dry coagulation, coagulation with a water-soluble organic liquid, and salting out coagulation are applied. Among these, it is preferable to perform by salting out the latex composition by adding it to an aqueous solution containing a coagulant. Examples of the coagulant include calcium chloride, sodium chloride, calcium hydroxide, aluminum sulfate, and aluminum hydroxide. The amount of the coagulant used is preferably 0.5 to 150 parts by weight, particularly preferably 0.5 to 20 parts by weight with respect to 100 parts by weight of the nitrile copolymer rubber (A).

  In general, the crumb particle size has a great influence on the degree of dehydration in the vibrating screen or squeezer following the coagulation and washing process, the crumb recovery rate, and the degree of drying in the drying process. For example, if the crumb particle size is too small, the crumb particle size will be too small to flow out of the screen, or the polymer will be insufficiently squeezed by the squeezer and the degree of dehydration will decrease. , Productivity deteriorates. Therefore, the average particle diameter of crumb is preferably 0.5 to 40 mm.

  The washing, dehydrating and drying methods of crumb can be the same as the washing / dehydrating method and drying method in general rubber production. As a washing / dehydrating method, a crumb obtained by coagulation and water may be separated using a mesh filter, a centrifugal separator, etc., then washed, and the crumb may be dehydrated with a squeezer or the like. Next, the nitrile copolymer rubber of the present invention is dried by a band dryer, a ventilated vertical dryer, a single screw extruder, a twin screw extruder or the like generally used for rubber production until a desired water content is obtained. A composition can be obtained. Moreover, you may perform coagulation | solidification and drying simultaneously within a twin-screw extruder.

The Mooney viscosity (ML _{1 + 4} , 100 ° C.) of the nitrile copolymer rubber composition of the present invention thus obtained is preferably 5 to 300, more preferably 10 to 250.

  In addition, as a method for preparing the nitrile copolymer rubber composition of the present invention, for example, a latex of a nitrile copolymer rubber (A), a thermoplastic resin (B), a plasticizer (C ), And the inorganic filler (D), which is added as necessary, or all or a part of one or more components, and then coagulated and dried, and the remaining components are rolled or banbury mixer. It can also be obtained by kneading with a kneader.

Crosslinkable nitrile copolymer rubber composition The crosslinkable nitrile copolymer rubber composition of the present invention is obtained by adding a crosslinking agent to the nitrile copolymer rubber composition of the present invention described above.

  The crosslinking agent is not particularly limited as long as it is usually used as a crosslinking agent for nitrile copolymer rubber. A typical crosslinking agent includes a sulfur-based crosslinking agent or an organic peroxide crosslinking agent that bridges between unsaturated bonds of the nitrile copolymer rubber (A). These can be used individually by 1 type or in combination of multiple types. Among these, a sulfur type crosslinking agent is preferable.

  Sulfur-based crosslinking agents include powdered sulfur, sulfur white, precipitated sulfur, colloidal sulfur, surface-treated sulfur, insoluble sulfur, and other sulfur; sulfur chloride, sulfur dichloride, morpholine disulfide, alkylphenol disulfide, dibenzothiazyl disulfide, N, Sulfur-containing compounds such as N′-dithio-bis (hexahydro-2H-azenopine-2), phosphorus-containing polysulfides, polymer polysulfides; tetramethylthiuram disulfide, selenium dimethyldithiocarbamate, 2- (4′-morpholinodithio) And sulfur donating compounds such as benzothiazole; These can be used individually by 1 type or in combination of multiple types.

  Examples of the organic peroxide crosslinking agent include dicumyl peroxide, cumene hydroperoxide, t-butylcumyl peroxide, paramentane hydroperoxide, di-t-butyl peroxide, 1,3-bis (t-butylperoxyisopropyl) benzene, 1,4-bis (t-butylperoxyisopropyl) benzene, 1,1-di-t-butylperoxy-3,3-trimethylcyclohexane, 4,4-bis- (t-butyl-peroxy) -n-butylvale 2,5-dimethyl-2,5-di-t-butylperoxyhexane, 2,5-dimethyl-2,5-di-t-butylperoxyhexyne-3, 1,1-di-t-butyl Peroxy-3,5,5-trimethylcyclohexane, p-chlorobenzoyl peroxide, t-butylperoxy Propyl carbonate, t- butyl peroxybenzoate, and the like. These can be used individually by 1 type or in combination of multiple types.

  The content of the crosslinking agent in the crosslinkable nitrile copolymer rubber composition of the present invention is not particularly limited, but is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the nitrile copolymer rubber (A). More preferably, it is 0.2 to 5 parts by weight.

  When an organic peroxide crosslinking agent is used, a multifunctional monomer such as trimethylolpropane trimethacrylate, divinylbenzene, ethylene dimethacrylate, or triallyl isocyanurate can be used in combination as a crosslinking aid. . Although the usage-amount of these crosslinking adjuvants is not specifically limited, Preferably it is the range of 0.5-20 weight part with respect to 100 weight part of nitrile copolymer rubber (A).

  When using a sulfur-based crosslinking agent, a crosslinking assistant such as zinc white or stearic acid; a crosslinking accelerator such as guanidine, aldehyde-amine, aldehyde-ammonia, thiazole, sulfenamide, thiourea Can be used in combination. The amounts of these crosslinking aids and crosslinking accelerators are not particularly limited, and are preferably in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the nitrile copolymer rubber (A).

  In addition, the nitrile copolymer rubber composition or the crosslinkable nitrile copolymer rubber composition of the present invention includes other compounding agents used for general rubber as necessary, for example, a crosslinking retarder, an antiaging agent. , Fillers other than inorganic fillers (D), lubricants, adhesives, lubricants, processing aids, plasticizers other than plasticizers (C), flame retardants, antifungal agents, antistatic agents, colorants, couplings You may mix | blend additives, such as an agent.

  As the anti-aging agent, an anti-aging agent such as phenol, amine, benzimidazole or phosphoric acid can be used. In the phenol system, 2,2′-methylenebis (4-methyl-6-tert-butylphenol) and the like are used, and in the amine system, 4,4′-bis (α, α-dimethylbenzyl) diphenylamine, N-isopropyl-N ′. -Phenyl-p-phenylenediamine and the like, and benzimidazole type include 2-mercaptobenzimidazole and the like. These may be used alone or in combination of two or more.

  Examples of fillers other than the inorganic filler (D) include carbon black, silica, calcium carbonate, aluminum silicate, magnesium silicate, calcium silicate, magnesium oxide, short fiber, zinc (meth) acrylate, and (meth) acrylic. And α, β-ethylenically unsaturated carboxylic acid metal salts such as magnesium acid. These fillers are subjected to a coupling treatment with a silane coupling agent, a titanium coupling agent, etc., and a surface modification treatment agent with a higher fatty acid derivative or a surfactant such as a higher fatty acid or its metal salt, ester or amide. Can do.

  In addition, the nitrile copolymer rubber composition and the crosslinkable nitrile copolymer rubber composition of the present invention include a nitrile copolymer rubber (A) and a thermoplastic resin (B) as long as the effects of the present invention are not impaired. Other polymers may be contained. The polymer other than the nitrile copolymer rubber (A) and the thermoplastic resin (B) is not particularly limited, but fluorine rubber, styrene-butadiene copolymer rubber, ethylene-propylene copolymer rubber, ethylene-propylene- Examples thereof include diene terpolymer rubber, natural rubber and polyisoprene rubber, epichlorohydrin rubber, urethane rubber, chloroprene rubber, ethylene-vinyl acetate copolymer, chlorosulfonated polyethylene, and the like. The blending amount in the case of blending a polymer other than the nitrile copolymer rubber (A) is preferably 100 parts by weight or less, more preferably 50 parts by weight with respect to 100 parts by weight of the nitrile copolymer rubber (A). Part or less, particularly preferably 30 parts by weight or less.

  The method for preparing the crosslinkable nitrile copolymer rubber composition of the present invention is not particularly limited, but a crosslinking agent, a crosslinking aid and other compounding agents are added to the nitrile copolymer rubber composition described above, and a roll Or kneading with a kneading machine such as a Banbury mixer. In this case, the blending order is not particularly limited. However, after sufficiently mixing components that are not easily reacted or decomposed by heat, components that are easily reacted by heat or components that are easily decomposed, such as a crosslinking agent, a crosslinking accelerator, etc. Mixing in a short time at a temperature at which no reaction or decomposition occurs.

The Mooney viscosity (ML _{1 + 4} , 100 ° C.) of the crosslinkable nitrile copolymer rubber composition of the present invention is preferably 5 to 300, more preferably 10 to 250.

Cross-linked rubber The cross-linked rubber of the present invention is formed by cross-linking the cross-linkable nitrile copolymer rubber composition.
When crosslinking the crosslinkable nitrile copolymer rubber composition of the present invention, a molding machine corresponding to the shape of the molded product (rubber crosslinked product) to be produced, such as an extruder, an injection molding machine, a compressor, a roll, etc. Then, the shape of the cross-linked product is fixed by carrying out a cross-linking reaction. When cross-linking is performed, the cross-linking may be performed after molding or may be performed simultaneously with the molding. The molding temperature is usually 10 to 200 ° C, preferably 25 to 120 ° C. The crosslinking temperature is usually 100 to 200 ° C., preferably 130 to 190 ° C., and the crosslinking time is usually 1 minute to 24 hours, preferably 2 minutes to 2 hours.

  Further, depending on the shape, size, etc. of the rubber cross-linked product, even if the surface is cross-linked, it may not be sufficiently cross-linked to the inside. Therefore, secondary cross-linking may be performed by heating.

  The rubber cross-linked product of the present invention thus obtained is excellent in gasoline permeation resistance, cold resistance, and ozone resistance. Therefore, it can be suitably used as a fuel hose or the like by forming a hose consisting of one layer or two or more layers in which the layer (I) comprising the crosslinked rubber of the present invention is at least one layer. In the case of a laminate of two or more layers, the layer (I) composed of the rubber cross-linked product of the present invention may be used for any of the inner layer, intermediate layer and outer layer. As the polymer constituting the layer (II) other than the layer (I) of the laminate, the α, β-ethylenically unsaturated nitrile monomer unit content is preferably 5 to 60% by weight, more preferably Nitrile copolymer rubber (L) of 18 to 55% by weight, those containing the nitrile copolymer rubber (L) and acrylic resin and / or vinyl chloride resin, fluorine rubber, chloroprene rubber, hydrin rubber, chloro Sulfonated polyethylene rubber, acrylic rubber, ethylene-acrylic acid copolymer, ethylene-propylene copolymer, ethylene-propylene-diene terpolymer, butyl rubber, isoprene rubber, natural rubber, styrene-butadiene copolymer, fluorine Resin, polyamide resin, polyvinyl alcohol, ethylene-vinyl acetate copolymer resin, ethylene-vinyl alcohol copolymer Resins, polybutylene naphthalate, polyphenylene sulfide, polyolefin resins, and polyester resins. These can be used individually by 1 type or in combination of multiple types. In addition, as a method of making the polymer constituting the layer (II) into a composition, for example, the polymer is a crosslinking agent, a crosslinking assistant, a crosslinking retarder, an anti-aging agent, a filler, a lubricant, an adhesive, a lubricant, Examples thereof include a method of blending additives such as processing aids, plasticizers, flame retardants, antifungal agents, antistatic agents, colorants, coupling agents, and kneading.

  Further, if necessary, in order to bond the layer (I) and the layer (II), either or both of the layer (I) and the layer (II) are added with a phosnium salt, 1,8-diazabicyclo (5.4). 0.0) Undecene-7 salt (DBU salt), 1,5-diazabicyclo (4.3.0) -nonene-5 salt (DBN salt), etc., and may contain layers (I) and (II). In the meantime, a new layer (III) may be used as an adhesive layer. As the layer (III), the same resin or rubber composition as the resin or rubber constituting the layer (II) described above can be used. In this case, the resin or rubber composition constituting the layer (II) described above can be used singly or in combination, and phosnium salt, 1,8-diazabicyclo (5.4.0) undecene-7 salt. (DBU salt), 1,5-diazabicyclo (4.3.0) -nonene-5 salt (DBN salt) and the like may be contained.

  Here, the thickness of the layer (I) is preferably 0.1 to 10 mm, more preferably 0.5 to 5 mm. In the case of a laminate of two or more layers, the thickness of the layers other than the layer (I) is preferably 0.1 to 10 mm, more preferably 0.5 to 5 mm.

  The method for producing the hose including the rubber cross-linked product of the present invention having the above-described configuration is not particularly limited. However, the hose is molded into a cylindrical shape using an extruder or the like, and is crosslinked to form the hose. It becomes the hose of the invention. Since the crosslinkable nitrile copolymer rubber composition of the present invention has the property that mandrel cracks are unlikely to occur, it can be produced using a mandrel.

  That is, when the hose is a single layer composed only of the rubber cross-linked product of the present invention, first, the cross-linkable nitrile copolymer rubber composition of the present invention is formed into a cylindrical shape, and the obtained cylindrical shape It can be produced by fixing the shape by inserting a mandrel into the molded article and crosslinking the crosslinkable nitrile copolymer rubber composition.

  Alternatively, when the hose has a multilayer structure including the rubber cross-linked product of the present invention, a layer other than the cross-linked nitrile copolymer rubber composition of the present invention and the layer formed of the rubber cross-linked product of the present invention is formed. The resin or rubber composition to be formed is molded into a cylindrical shape while being laminated, and the shape is fixed by inserting a mandrel into the obtained cylindrical laminated molded body, and a crosslinkable nitrile copolymer rubber composition It can be produced by crosslinking the product.

  The rubber cross-linked product of the present invention comprises a seal member such as packing, gasket, O-ring and oil seal; hose such as oil hose, fuel hose, inlet hose, gas hose, brake hose, refrigerant hose; diaphragm; accumulator prada; However, it is particularly preferably used as a hose. Examples of the gas of the gas hose include air, nitrogen, oxygen, hydrogen, carbon dioxide, carbon monoxide, methane, ethane, propane, dimethyl ether, LPG, and water vapor.

  The present invention will be specifically described below with reference to examples and comparative examples. In the following, “part” is based on weight unless otherwise specified. The test and evaluation were as follows.

The Mooney viscosity (polymer Mooney viscosity) (ML _{1 + 4} , 100 ° C.) of the Mooney viscosity nitrile copolymer rubber (including the case of “hydrogenated nitrile copolymer rubber”) was measured according to JIS K6300.

1 g of methylethylketone (MEK) insoluble nitrile copolymer rubber was immersed in 200 ml of methylethylketone, left to stand at 23 ° C. for 24 hours, filtered using a 325 mesh wire net, and the filtrate was evaporated to dryness and solidified. The dry solid content [methyl ethyl ketone soluble content: (y) g] is weighed, and the methyl ethyl ketone insoluble content is calculated by the following equation.
Methyl ethyl ketone insoluble matter (% by weight) = 100 × (1-y) / 1

Normal properties (tensile strength, elongation, 100% tensile stress, hardness)
A crosslinkable nitrile copolymer rubber composition (including the case of the “crosslinkable hydrogenated nitrile copolymer rubber composition”) is placed in a mold having a length of 15 cm, a width of 15 cm, and a depth of 0.2 cm, and 160 while applying pressure. It was press-molded at 20 ° C. for 20 minutes to obtain a sheet-like rubber crosslinked product. Using the obtained sheet-like rubber cross-linked product in accordance with JIS K6251, using a test piece punched out in dumbbell shape No. 3, the tensile strength, elongation and 100% tensile stress of the rubber cross-linked product are obtained. Also in accordance with JIS K6253. The hardness of the rubber cross-linked product was measured using a durometer hardness tester type A, respectively.

Gasoline permeability coefficient Prepare the same sheet-like rubber cross-linked product used for evaluation of the above-mentioned normal physical properties, and use "mixture of isooctane, toluene and ethanol in a weight ratio of 2: 2: 1" as fuel oil. The gasoline permeability coefficient was measured by the aluminum cup method. Specifically, 50 ml of the above fuel oil is put into a 100 ml capacity aluminum cup, and a sheet-like rubber cross-linked product is placed on the cup, which is then covered with a fastener and a sheet-like rubber cross-linked product. By adjusting the area separating the inside and outside of the aluminum cup to 25.50 cm ² , leaving the aluminum cup in a constant temperature bath at 23 ° C., and measuring the weight every 24 hours, so that The amount of permeation is measured, and the maximum amount is taken as the amount of permeation (unit: g · mm / m ² · day).
In addition, a gasoline permeability coefficient is so preferable that a value is low.

Brittle temperature The brittle temperature was measured in accordance with JIS K6261 using the same sheet-like rubber cross-linked product used for the evaluation of the normal state physical properties.

Ozone resistance test Ozone resistance under conditions of 72 hours at a temperature of 40 ° C., an ozone concentration of 50 pphm, and a 30% elongation according to JIS K6259 using the same sheet-like rubber cross-linked product used for evaluation of the above-mentioned normal physical properties. A test was conducted, and the ozone resistance was evaluated by observing the surface state of the sample after the test. Evaluation was performed according to the following criteria.
○: No occurrence of cracks was observed.
X: Generation | occurrence | production of the crack was recognized.

Production Example 1 (Production of vinyl chloride resin latex)
A pressure-resistant reaction vessel was charged with 120 parts of water, 0.8 part of sodium lauryl sulfate and 0.06 part of potassium persulfate, and after repeated vacuum degassing twice, 100 parts of vinyl chloride was added and heated while stirring. The emulsion polymerization was carried out at 47 ° C. After the polymerization conversion reached 90%, it was cooled to room temperature to remove unreacted monomers. The resulting vinyl chloride resin latex had a solid content concentration of 41% by weight. The average particle size of the vinyl chloride resin was 0.3 μm, the average degree of polymerization according to JIS K6721 was 1,300, and the glass transition temperature was 80 ° C.

Production Example 2 (Production of latex of acrylic resin)
In a reactor equipped with a thermometer and a stirring device, 150 parts of ion exchange water, 2 parts of sodium octyl sulfate, 0.3 part of ammonium persulfate (polymerization initiator), 80 parts of methyl methacrylate, 20 parts of acrylonitrile and t-dodecyl mercaptan (Molecular weight adjusting agent) 0.05 part was added, emulsion polymerization was started at a temperature of 80 ° C. with stirring, and the reaction was stopped after 5 hours to obtain a latex. The obtained acrylic resin latex had a solid content of 39% by weight and a polymerization conversion rate of 98% by weight. The average particle diameter of the acrylic resin was 0.2 μm, the number average molecular weight was 600,000, and the glass transition temperature was 103 ° C.

Example 1
Preparation of latex of nitrile copolymer rubber A reaction vessel was charged with 240 parts of water, 78 parts of acrylonitrile, 10 parts of styrene, 0.4 part of trimethylolpropane trimethacrylate and 2.5 parts of sodium dodecylbenzenesulfonate (emulsifier), The temperature was adjusted to 5 ° C. Next, after depressurizing and sufficiently degassing the gas phase, 11.6 parts of 1,3-butadiene, 0.06 parts of p-menthane hydroperoxide as a polymerization initiator, 0.02 parts of sodium ethylenediaminetetraacetate First reaction of emulsion polymerization by adding 0.006 part of ferrous sulfate (7 water salt) and 0.06 part of sodium formaldehyde sulfoxylate and 0.5 part of t-dodecyl mercaptan as a chain transfer agent Started. After the start of the reaction, when the polymerization conversion ratio with respect to the charged monomer reaches 28 wt%, 47 wt% and 60 wt%, 7 parts, 7 parts and 7 parts of 1,3-butadiene are added to the reaction vessel, respectively. The second, third, and fourth stage polymerization reactions were performed. When the polymerization conversion rate with respect to all charged monomers reached 70% by weight, 0.3 part of hydroxylamine sulfate and 0.2 part of potassium hydroxide were added to terminate the polymerization reaction. After the reaction was stopped, the contents in the reaction vessel were heated to 70 ° C., and unreacted monomers were recovered by steam distillation under reduced pressure to obtain a latex of nitrile copolymer rubber (A1) (solid content concentration 23 wt% )

  When the content ratio of each monomer unit constituting the obtained nitrile copolymer rubber (A1) was measured using an NMR apparatus (ADVANCE III400) manufactured by Bruker BioSpin Corporation, 50% by weight of acrylonitrile unit, styrene The unit was 10% by weight and the 1,3-butadiene unit was 40% by weight. The nitrile copolymer rubber (A1) had an insoluble content in methyl ethyl ketone (MEK) of 74% by weight.

Preparation of latex composition of nitrile copolymer rubber Di (butoxyethoxyethyl) adipate as a plasticizer (C) (product name “ADEKA SIZER RS-107”, manufactured by ADEKA, SP value 9.2 (cal / cm ³ ) A 50% by weight aqueous emulsion of ^1/2 ) was prepared by mixing 2% by weight of the plasticizer with potassium oleate as an emulsifier and mixing under strong stirring. Then, while stirring the latex of the nitrile copolymer rubber (A1) obtained above in a container, 100 parts of the nitrile copolymer rubber (A1) is mixed with adipic acid diacid as a plasticizer (C). 70 parts of an emulsion containing (butoxyethoxyethyl) (35 parts of plasticizer) and the vinyl chloride resin latex obtained in Production Example 1 (65 parts of vinyl chloride resin) are added and mixed and dispersed. A polymer latex composition was obtained. Then, the obtained nitrile copolymer latex composition is an aqueous solution containing calcium chloride (coagulant) in an amount of 4% by weight with respect to the amount of nitrile copolymer rubber (A1) in the latex composition. The mixture was poured and solidified under stirring to produce a crumb comprising a mixture of the nitrile copolymer rubber (A1), the vinyl chloride resin as the thermoplastic resin (B), and the plasticizer (C).

Preparation of a crosslinkable nitrile copolymer rubber composition, and the obtained crumb was filtered, washed with water, dried under reduced pressure at 60 ° C., and then the dried crumb was heated to 180 ° C. using a Banbury mixer. Until kneaded. And after kneading | mixing, after moving to a roll and cooling, again using a Banbury mixer, 100 parts of nitrile copolymer rubber (A1) is used for MT carbon black ("Thermax ^(R) medium thermal carbon black N990", 20 parts of CANCARB), 5 parts of zinc white as a crosslinking aid and 1 part of stearic acid were added and mixed at 50 ° C. Then, this mixture is transferred to a roll and 0.6 part of 325 mesh sulfur as a crosslinking agent and 2.5 parts of tetramethylthiuram disulfide (trade name “Noxeller TT”, manufactured by Ouchi Shinsei Chemical Co., Ltd.), and N-cyclohexyl. -2-Benzothiazolylsulfenamide (trade name “Noxeller CZ”, manufactured by Ouchi Shinsei Chemical Co., Ltd., crosslinking accelerator) 2.5 parts was added and kneaded at 50 ° C. to form a crosslinkable nitrile copolymer rubber. A composition was prepared.

  About the rubber cross-linked product obtained by cross-linking the obtained cross-linkable nitrile copolymer rubber composition, normal properties (tensile strength, elongation, 100% tensile stress, hardness), gasoline permeability coefficient, embrittlement temperature, And each evaluation of ozone resistance was performed. The results are shown in Table 1.

Example 2
A latex of nitrile copolymer rubber (A2) (solid content) was prepared in the same manner as in Example 1 except that the amount of trimethylolpropane trimethacrylate was changed to 0.1 part when producing the nitrile copolymer rubber. A concentration of 23% by weight) was obtained. When the content ratio of each monomer unit constituting the obtained nitrile copolymer rubber (A2) was measured in the same manner as in Example 1, 50% by weight of acrylonitrile unit, 10% by weight of styrene unit, 1, 3 -It was 40 weight% of butadiene units. Further, the insoluble content of methyl ethyl ketone (MEK) in the nitrile copolymer rubber (A2) was 35% by weight.

  Then, a crosslinkable nitrile copolymer rubber was used in the same manner as in Example 1 except that the latex of the obtained nitrile copolymer rubber (A2) was used instead of the latex of the nitrile copolymer rubber (A1). Compositions were prepared and evaluated in the same manner. The results are shown in Table 1.

Example 3
In producing the nitrile copolymer rubber, the monomers charged for the first stage of the emulsion polymerization were 75 parts of acrylonitrile, 17 parts of styrene, 0.4 part of trimethylolpropane trimethacrylate and 1,3-butadiene 7 When the polymerization conversion reached 45 wt% and 60 wt%, respectively, 9 parts and 9 parts of 1,3-butadiene were added to the reaction vessel, respectively, and the second and third stages were changed. A latex of nitrile copolymer rubber (A3) (solid content concentration 23% by weight) was obtained in the same manner as in Example 1 except that the polymerization reaction was performed. When the content ratio of each monomer unit constituting the obtained nitrile copolymer rubber (A3) was measured in the same manner as in Example 1, 50% by weight of acrylonitrile unit, 20% by weight of styrene unit, 1, 3 -The butadiene unit was 30% by weight. The nitrile copolymer rubber (A3) had an insoluble content in methyl ethyl ketone (MEK) of 76% by weight.

  Then, a crosslinkable nitrile copolymer rubber was used in the same manner as in Example 1 except that the latex of the obtained nitrile copolymer rubber (A3) was used instead of the latex of the nitrile copolymer rubber (A1). Compositions were prepared and evaluated in the same manner. The results are shown in Table 1.

Example 4
In producing the nitrile copolymer rubber, the monomers charged in the first stage of the emulsion polymerization were 77.2 parts of acrylonitrile, 9.8 parts of styrene, 0.4 part of trimethylolpropane trimethacrylate, 1, A latex of nitrile copolymer rubber (A4) (solid content concentration 23% by weight) was obtained in the same manner as in Example 1 except for changing to 10.3 parts of 3-butadiene and 2.3 parts of 2-vinylpyridine. Obtained. When the content ratio of each monomer unit constituting the obtained nitrile copolymer rubber (A4) was measured in the same manner as in Example 1, 50% by weight of acrylonitrile unit, 10% by weight of styrene unit, 1, 3 -It was 38 weight% of butadiene units and 2 weight% of 2-vinylpyridine units. The nitrile copolymer rubber (A4) insoluble in methyl ethyl ketone (MEK) was 75% by weight.

  Then, a crosslinkable nitrile copolymer rubber was used in the same manner as in Example 1 except that the latex of the obtained nitrile copolymer rubber (A4) was used instead of the latex of the nitrile copolymer rubber (A1). Compositions were prepared and evaluated in the same manner. The results are shown in Table 1.

Example 5
A crosslinkable nitrile copolymer was prepared in the same manner as in Example 1, except that the acrylic resin latex obtained in Production Example 2 (65 parts of acrylic resin) was used instead of the vinyl chloride resin latex obtained in Production Example 1. A polymer rubber composition was prepared and evaluated in the same manner. The results are shown in Table 1.

Example 6
100 parts of purified bentonite (trade name “Bengel HV”, manufactured by Hojun Co., Ltd., aspect ratio: 295) as an inorganic filler (D) is added to 1995 parts of distilled water in the presence of 5 parts of sodium polyacrylate. To obtain an aqueous dispersion of an inorganic filler (D) having a solid content concentration of 5%. Then, when preparing the nitrile copolymer latex composition, the aqueous dispersion of the obtained inorganic filler (D) was added to the solid content of the nitrile copolymer rubber (A1) latex (the amount of nitrile copolymer rubber). ) Chloride as nitrile copolymer rubber (A1) and thermoplastic resin (B) in the same manner as in Example 1 except that 100 parts are added to 25 parts of inorganic filler (D). A crumb comprising a mixture of vinyl resin, plasticizer (C) and inorganic filler (D) was produced.
Then, the obtained crumb was separated by filtration, washed with water, dried under reduced pressure at 60 ° C., and then the dried crumb was kneaded using a Banbury mixer until the temperature reached 180 ° C. Next, after kneading and transferring to a roll and cooling, MT carbon black ("Thermax ^(R) medium thermal carbon black N990", 100 parts of nitrile copolymer rubber (A1) is again used with a Banbury mixer. CANCARB) 20 parts, 5 parts of zinc white as a crosslinking aid and 1 part of stearic acid, 0.5 part of β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane was added and 50 ° C. was added. And mixed. Then, this mixture is transferred to a roll and 0.6 part of 325 mesh sulfur as a crosslinking agent and 2.5 parts of tetramethylthiuram disulfide (trade name “Noxeller TT”, manufactured by Ouchi Shinsei Chemical Co., Ltd.), and N-cyclohexyl. -2-Benzothiazolylsulfenamide (trade name “Noxeller CZ”, manufactured by Ouchi Shinsei Chemical Co., Ltd., crosslinking accelerator) 2.5 parts was added and kneaded at 50 ° C. to form a crosslinkable nitrile copolymer rubber. A composition was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 7
In Example 6, when preparing the nitrile copolymer latex composition, the same procedure as in Example 6 was conducted, except that the addition amount of purified bentonite as the inorganic filler (D) was changed from 20 parts to 15 parts. A crosslinkable nitrile copolymer rubber composition was prepared and evaluated. The results are shown in Table 1.

Comparative Example 1
In producing the nitrile copolymer rubber, the monomers charged in the first stage of the emulsion polymerization were 10 parts of acrylonitrile, 45 parts of styrene, 0.2 part of trimethylolpropane trimethacrylate and 1,3-butadiene 44. When the polymerization conversion reached 28 wt% and 47 wt%, respectively, 10 parts and 9 parts of acrylonitrile were added to the reaction vessel, respectively, and the second and third stage polymerization reactions were carried out. A latex of nitrile copolymer rubber (A5) (solid content concentration: 22% by weight) was obtained in the same manner as in Example 1 except for the above. When the content ratio of each monomer unit constituting the obtained nitrile copolymer rubber (A5) was measured in the same manner as in Example 1, 25% by weight of acrylonitrile units, 30% by weight of styrene units, 1, 3 -It was 45 weight% of butadiene units. The nitrile copolymer rubber (A5) had an insoluble content in methyl ethyl ketone (MEK) of 60% by weight.

  Then, a crosslinkable nitrile copolymer rubber was used in the same manner as in Example 1 except that the latex of the obtained nitrile copolymer rubber (A5) was used instead of the latex of the nitrile copolymer rubber (A1). Compositions were prepared and evaluated. The results are shown in Table 1.

Comparative Example 2
In producing the nitrile copolymer rubber, the first stage reaction monomer for emulsion polymerization was added to 78 parts of acrylonitrile, 0.4 parts of trimethylolpropane trimethacrylate and 21.6 parts of 1,3-butadiene. When the polymerization conversions reached 36 wt% and 53 wt%, respectively, 13.5 parts and 13 parts of 1,3-butadiene were added to the reaction vessel, respectively, and the second and third stage polymerizations were performed. A latex of nitrile copolymer rubber (A6) (solid content concentration 22% by weight) was obtained in the same manner as in Example 1 except that the reaction was performed. When the content ratio of each monomer unit constituting the obtained nitrile copolymer rubber (A6) was measured in the same manner as in Example 1, 50% by weight of acrylonitrile units and 50% by weight of 1,3-butadiene units were measured. Met. Further, the insoluble matter in methyl ethyl ketone (MEK) of the nitrile copolymer rubber (A6) was 73% by weight.

  Then, a crosslinkable nitrile copolymer rubber was used in the same manner as in Example 1 except that the latex of the obtained nitrile copolymer rubber (A6) was used instead of the latex of the nitrile copolymer rubber (A1). Compositions were prepared and evaluated in the same manner. The results are shown in Table 1.

Comparative Example 3
When the nitrile copolymer rubber was produced, the first stage reaction monomer for emulsion polymerization was 26 parts acrylonitrile, 9 parts styrene, 0.5 part trimethylolpropane trimethacrylate and 1,3-butadiene 64. A latex of nitrile copolymer rubber (A7) (solid content concentration 22% by weight) was obtained in the same manner as in Example 1 except that the content was changed to 5 parts. When the content ratio of each monomer unit constituting the obtained nitrile copolymer rubber (A7) was measured in the same manner as in Example 1, 30% by weight of acrylonitrile unit, 5% by weight of styrene unit, 1, 3 -It was 65 weight% of butadiene units. Further, the insoluble matter in methyl ethyl ketone (MEK) of the nitrile copolymer rubber (A7) was 80% by weight.

  Then, a crosslinkable nitrile copolymer rubber was used in the same manner as in Example 1 except that the latex of the obtained nitrile copolymer rubber (A7) was used instead of the latex of the nitrile copolymer rubber (A1). Compositions were prepared and evaluated in the same manner. The results are shown in Table 1.

Comparative Example 4
A latex of nitrile copolymer rubber (A8) (solid content) was prepared in the same manner as in Example 1 except that the polymerization reaction was performed without using trimethylolpropane trimethacrylate when producing the nitrile copolymer rubber. A concentration of 23% by weight) was obtained. When the content ratio of each monomer unit constituting the obtained nitrile copolymer rubber (A8) was measured in the same manner as in Example 1, 50% by weight of acrylonitrile unit, 10% by weight of styrene unit, 1, 3 -It was 40 weight% of butadiene units. The nitrile copolymer rubber (A8) had an insoluble content in methyl ethyl ketone (MEK) of 2% by weight.

  Then, a crosslinkable nitrile copolymer rubber was used in the same manner as in Example 1 except that the latex of the obtained nitrile copolymer rubber (A8) was used instead of the latex of the nitrile copolymer rubber (A1). A composition was prepared and evaluated in the same manner. The results are shown in Table 1.

Comparative Example 5
Crosslinkability in the same manner as in Example 1 except that no vinyl chloride resin latex was used and the blending amount of di (butoxyethyl) adipate as the plasticizer (C) was changed from 35 parts to 15 parts. A nitrile copolymer rubber composition was prepared and evaluated in the same manner. The results are shown in Table 1.

Comparative Example 6
Instead of adipate as a plasticizer (C) (butoxyethoxyethyl) alkyl naphthene _{(C 10 H 7 -C n H} 2n + 1 (n = 16~18), Product Name: barrel Process Oil B-28AN A crosslinkable nitrile copolymer rubber composition was prepared in the same manner as in Example 1 except that Matsumura Oil Co., Ltd., SP value 7.8 (cal / cm ³ ) ^1/2 ) was used. And evaluated. The results are shown in Table 1.

Comparative Example 7
Instead of di (butoxyethoxyethyl) adipate as the plasticizer (C), dimethyl phthalate (product name: DMP, manufactured by Daihachi Chemical Industry Co., Ltd., SP value 10.5 (cal / cm ³ ) ^1/2 ) Was used in the same manner as in Example 1 except that a crosslinkable nitrile copolymer rubber composition was prepared and evaluated in the same manner. The results are shown in Table 1.

Example 8
About the latex of the nitrile copolymer rubber (A1) obtained in Example 1, a palladium catalyst (1 wt% acetic acid was added to the reactor so that the palladium content was 1000 ppm with respect to the dry rubber weight contained in the latex. A solution obtained by mixing a palladium acetone solution and an equal weight of ion exchange water) is added, and hydrogenation reaction is performed at a hydrogen pressure of 3 MPa and a temperature of 50 ° C. for 6 hours to obtain a latex of hydrogenated nitrile copolymer rubber (A9). It was. When the content ratio of each monomer unit constituting the obtained hydrogenated nitrile copolymer rubber (A9) was measured in the same manner as in Example 1, 50% by weight of acrylonitrile monomer unit, 10% by weight of styrene unit. %, A total of 40% by weight of 1,3-butadiene units and saturated butadiene units. The iodine value of the hydrogenated nitrile copolymer rubber (A9) was 38, and the insoluble content of methyl ethyl ketone (MEK) was 79% by weight.

  Then, a crosslinkable hydrogenated nitrile was obtained in the same manner as in Example 1 except that the latex of the obtained hydrogenated nitrile copolymer rubber (A9) was used instead of the latex of the nitrile copolymer rubber (A1). A copolymer rubber composition was prepared and evaluated in the same manner. The results are shown in Table 2.

Comparative Example 8
A hydrogenation reaction was performed in the same manner as in Example 7 except that the latex of the nitrile copolymer rubber (A8) obtained in Comparative Example 4 was used instead of the latex of the nitrile copolymer rubber (A1). A latex of hydrogenated nitrile copolymer rubber (A10) was obtained. The content ratio of each monomer unit constituting the obtained hydrogenated nitrile copolymer rubber (A10) was measured in the same manner as in Example 1. As a result, 50% by weight of acrylonitrile monomer unit and 10% by weight of styrene unit were measured. %, A total of 40% by weight of 1,3-butadiene units and saturated butadiene units. The iodine value of the hydrogenated nitrile copolymer rubber (A10) was 21, and the methyl ethyl ketone (MEK) insoluble content was 3% by weight.

  Then, a crosslinkable hydrogenated nitrile was obtained in the same manner as in Example 1 except that the latex of the obtained hydrogenated nitrile copolymer rubber (A10) was used instead of the latex of the nitrile copolymer rubber (A1). A copolymer rubber composition was prepared and evaluated in the same manner. The results are shown in Table 2.

From Tables 1 and 2, to the nitrile copolymer rubber (A) having a predetermined composition, at least one thermoplastic resin (B) selected from the group consisting of vinyl chloride resin and acrylic resin, and SP value is 8.0. Nitrile copolymer rubber composition containing a plasticizer (C) that is ˜10.2 (cal / cm ³ ) ^1/2 in a predetermined ratio (including “hydrogenated nitrile copolymer rubber composition”) The rubber cross-linked product obtained by cross-linking was excellent in normal properties and excellent in gasoline permeation resistance, cold resistance and ozone resistance (Examples 1 to 8).

On the other hand, when the nitrile copolymer rubber in which the content of the acrylonitrile unit is too low as the α, β-ethylenically unsaturated nitrile monomer unit (a1) is used, and the aromatic vinyl monomer unit When the nitrile copolymer rubber not containing a styrene unit as (a2) was used, the result was inferior in gasoline permeation resistance (Comparative Examples 1 and 2).
A nitrile copolymer rubber in which the total content of the acrylonitrile unit as the α, β-ethylenically unsaturated nitrile monomer unit (a1) and the styrene unit as the aromatic vinyl monomer unit (a2) is too small. When used, and when a nitrile copolymer rubber having too little insoluble matter in methyl ethyl ketone (MEK) was used, the results were inferior in gasoline permeation resistance (Comparative Examples 3, 4, and 8).
Further, when the thermoplastic resin (B) was not blended, the results were inferior in gasoline permeability resistance and ozone resistance (Comparative Example 5).
Furthermore, when a plasticizer having an SP value that is too low is used, the result is inferior in gasoline permeation resistance, and when a plasticizer having an SP value that is too high, the result is inferior in cold resistance ( Comparative Examples 6 and 7).

Claims (9)

α, β-ethylenically unsaturated nitrile monomer unit (a1) 30 to 65 % by weight, aromatic vinyl monomer unit (a2) 5 to 40 % by weight, and conjugated diene monomer unit (a3) 25 The total of the α, β-ethylenically unsaturated nitrile monomer unit (a1) and the aromatic vinyl monomer unit (a2) is 40 to 75% by weight, A nitrile copolymer rubber (A) having a dissolved content of 20 to 90% by weight;
At least one thermoplastic resin (B) selected from the group consisting of vinyl chloride resin and acrylic resin;
A plasticizer (C) having an SP value of 8.0 to 10.2 (cal / cm ³ ) ^1/2 by the HOY method,
The nitrile copolymer in which the ratio of the thermoplastic resin (B) is 10 to 150 parts by weight and the ratio of the plasticizer (C) is 0.1 to 200 parts by weight with respect to 100 parts by weight of the nitrile copolymer rubber (A). Polymer rubber composition.   The nitrile copolymer rubber (A) further has a cationic monomer unit and / or a monomer unit (a4) capable of forming a cation, and in the nitrile copolymer rubber (A), The nitrile copolymer rubber composition according to claim 1, wherein the content of the cationic monomer unit and / or the monomer unit (a4) capable of forming a cation is 0.1 to 30% by weight.   The nitrile copolymer rubber according to claim 1 or 2, wherein the nitrile copolymer rubber (A) is a hydrogenated nitrile copolymer rubber in which at least a part of a carbon-carbon unsaturated bond portion is hydrogenated. Composition.   It further contains an inorganic filler (D) having an aspect ratio of 30 to 2,000, and the ratio of the inorganic filler (D) to 100 parts by weight of the nitrile copolymer rubber (A) is 1 to 200 weights. The nitrile copolymer rubber composition according to any one of claims 1 to 3, which is a part.   A crosslinkable nitrile copolymer rubber composition obtained by adding a crosslinking agent to the nitrile copolymer rubber composition according to any one of claims 1 to 4.   A rubber cross-linked product obtained by cross-linking the cross-linkable nitrile copolymer rubber composition according to claim 5.   A laminate comprising two or more layers, wherein at least one layer comprises the rubber cross-linked product according to claim 6.   A hose obtained by crosslinking a molded product obtained by molding the crosslinkable nitrile copolymer rubber composition according to claim 5 into a cylindrical shape and inserting a mandrel.   A hose obtained by crosslinking a molded body obtained by molding a laminate of two or more layers including a layer made of the crosslinkable nitrile copolymer rubber composition according to claim 5 into a cylindrical shape and inserting a mandrel. .