JP2010155883A - Nitrile copolymer rubber composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nitrile copolymer rubber composition which gives a rubber crosslinked substance excellent in gasoline permeation resistance, sour gasoline resistance and permanent compression set resistance. <P>SOLUTION: The nitrile copolymer rubber composition contains nitrile copolymer rubber (A) having 43-60 wt.% of α,β-ethylenically unsaturated nitrile monomeric unit and glass flake (B) of which an average area of the principal surface is 1 μm<SP>2</SP>or more, wherein a content proportion of the glass flake (B) is 1-30 pts.wt. based on 100 pts.wt. of the nitrile copolymer rubber (A). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a nitrile copolymer rubber composition that provides a rubber cross-linked product having excellent gasoline permeation resistance, sour gasoline resistance and compression set 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.

  In recent years, due to the increase in global environmental protection activities, efforts to reduce the transpiration of fuels such as gasoline into the atmosphere have progressed, and even in Japan, gasoline permeability is even lower in applications such as fuel hoses, seals and packing. It has been demanded. The fuel hose is also required to be resistant to free radicals (sour gasoline resistance) generated in sour gasoline.

  Under such circumstances, Patent Document 1 discloses various rubber latexes, montmorillonite suspension water, and montmorillonites such as pyrophosphate compounds in order to improve the properties of a crosslinked product obtained by dispersing and mixing a clay substance in rubber latex. It is proposed to mix with a dispersing agent for use at high speed. However, in the method of Patent Document 1, although the gas barrier property of the obtained crosslinked product is improved, the gasoline permeation resistance is insufficient.

  Patent Document 2 discloses a rubber for preparing a mixed liquid containing a rubber-based polymer and a layered inorganic compound, and recovering a rubber composition containing the rubber-based polymer and the layered inorganic compound from the prepared mixed liquid. A method of manufacturing the composition is disclosed. However, in Patent Document 2, the purpose is to obtain a rubber cross-linked product excellent in vibration damping properties, and the gasoline permeation resistance and sour gasoline resistance are insufficient.

JP 2006-70137 A JP 2003-201373 A

  An object of the present invention is to provide a nitrile copolymer rubber composition that provides a rubber cross-linked product excellent in gasoline permeation resistance, sour gasoline resistance and compression set resistance in view of such a situation. To do.

The inventors add a specific amount of glass flakes having an average area of 1 μm ² or more to a nitrile copolymer rubber having a predetermined amount of α, β-ethylenically unsaturated nitrile monomer units. It was found that the above object can be achieved by the nitrile copolymer rubber composition obtained by the above, and the present invention has been completed.

That is, according to the present invention, a nitrile copolymer rubber (A) having 43 to 60% by weight of an α, β-ethylenically unsaturated nitrile monomer unit and a glass having an average surface area of 1 μm ² or more. A nitrile copolymer rubber composition containing 1 to 30 parts by weight of the glass flakes (B) with respect to 100 parts by weight of the nitrile copolymer rubber (A). Things are provided.

Preferably, the glass flake (B) is surface-treated with a coupling agent.
Preferably, the nitrile copolymer rubber (A) further has a cationic monomer unit and / or a monomer unit capable of forming a cation, and in the nitrile copolymer rubber (A), The content ratio of the cationic monomer unit and / or the monomer unit capable of forming a cation is 0.1 to 20% by weight.
Preferably, the nitrile copolymer rubber composition of the present invention further contains a plasticizer.
Preferably, the nitrile copolymer rubber composition of the present invention further contains 10 to 150 parts by weight of a vinyl chloride resin and / or an acrylic resin with respect to 100 parts by weight of the nitrile copolymer rubber (A). To do.

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

  ADVANTAGE OF THE INVENTION According to this invention, the nitrile copolymer rubber composition which provides the rubber crosslinked material excellent in gasoline-permeation resistance, sour gasoline resistance, and compression set resistance is provided.

The nitrile copolymer rubber composition of the present invention comprises a nitrile copolymer rubber (A) having 43 to 60% by weight of an α, β-ethylenically unsaturated nitrile monomer unit, and an average area of the main surface of 1 μm ^2. The glass flakes (B) as described above are contained, and the content ratio of the glass flakes (B) is 1 to 30 parts by weight with respect to 100 parts by weight of the nitrile copolymer rubber (A). It is.

Nitrile copolymer rubber (A)
First, the nitrile copolymer rubber (A) used in the present invention will be described.
The nitrile copolymer rubber (A) is a rubber having at least 43 to 60% by weight of an α, β-ethylenically unsaturated nitrile monomer unit.

  The content ratio of the α, β-ethylenically unsaturated nitrile monomer unit is 43 to 60% by weight, preferably 45 to 56% by weight, more preferably 46 to 53% by weight based on the total monomer units. %. If the content ratio of the α, β-ethylenically unsaturated nitrile monomer unit 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 is particularly limited as long as it is an α, β-ethylenically unsaturated compound having a nitrile group. Although not, for example, acrylonitrile; α-halogenoacrylonitrile such as α-chloroacrylonitrile and α-bromoacrylonitrile; α-alkylacrylonitrile such as methacrylonitrile; Among these, acrylonitrile and methacrylonitrile are preferable, and acrylonitrile is more preferable. 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 a monomer capable of forming a cationic monomer unit and / or a cation in addition to the α, β-ethylenically unsaturated nitrile monomer unit. It is preferable to further have a unit.

  The content ratio of the cationic monomer unit and / or the monomer unit capable of forming a cation is preferably 0.1 to 20% by weight, more preferably 0.3%, based on the total monomer units. -15% by weight, more preferably 0.5-10% by weight. By containing a cationic monomer unit and / or a monomer unit capable of forming a cation in the above range, the effect of the present invention becomes more remarkable.

  As a monomer that forms a cationic monomer unit and / or a monomer unit capable of forming a cation, a monomer having a positive chargeability when the resulting polymer is 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 body 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.

  Among the cationic monomers and the monomers capable of forming cations, the effects of the present invention become more prominent. Therefore, a vinyl group-containing cyclic amine monomer, a tertiary amino group-containing (meth) acrylic Acid ester monomers and tertiary amino group-containing (meth) acrylamide monomers are preferred, vinyl group-containing cyclic amine monomers and tertiary amino group-containing acrylamide monomers are more preferred, vinyl group-containing cyclic amines Monomers are particularly preferred. These can be used individually by 1 type or in combination of multiple types. In addition, as a vinyl group containing cyclic amine monomer, vinyl group containing pyridines are preferable and 2-vinyl pyridine is especially preferable.

  Further, the nitrile copolymer rubber (A) used in the present invention preferably contains a conjugated diene monomer unit so that the resulting rubber cross-linked product has rubber elasticity.

  The conjugated diene monomer forming the conjugated diene monomer unit is preferably a conjugated diene having 4 or more carbon atoms, such as 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 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 content ratio of the conjugated diene monomer unit in the nitrile copolymer rubber (A) is preferably 20 to 56.9% by weight, more preferably 29 to 54.7% by weight based on the total monomer units. %, More preferably 36 to 53.5% by weight. When the content rate of a conjugated diene monomer unit is too low, there exists a possibility that the rubber elasticity of the rubber crosslinked material obtained may fall. On the other hand, if the amount is too large, the heat aging resistance and chemical stability of the resulting rubber cross-linked product may be impaired.

  Further, the nitrile copolymer rubber (A) used in the present invention is the above α, β-ethylenically unsaturated nitrile monomer unit, cationic monomer unit and / or monomer unit capable of forming a cation, In addition to the conjugated diene monomer unit, other monomer units copolymerizable with the monomers forming these monomer units may be contained. 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 allyl glycidyl ether, butenyl glycidyl ether, octenyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, 3,4-epoxy-1-butene, 1,2 -Unsaturated epoxide compounds such as epoxy-5-hexene, 1,2-epoxy-9-decene, vinylcyclohexene monoxide; aromatic vinyl compounds such as styrene, α-methylstyrene, vinyltoluene; fluoroethyl vinyl ether, fluoropropyl Fluorine-containing vinyl compounds such as vinyl ether, o-trifluoromethylstyrene, vinyl pentafluorobenzoate, difluoroethylene, tetrafluoroethylene; 1,4-pentadiene, 1,4-hexadiene, vinylnorbornene, Non-conjugated diene compounds such as cyclopentadiene; α-olefin compounds such as ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene; acrylic acid, methacrylic acid, maleic acid, maleic anhydride Α, β-ethylenically unsaturated carboxylic acids such as acids, itaconic acid, itaconic anhydride, fumaric acid and the anhydrides thereof; methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, Α, β-ethylenically unsaturated carboxylic acid alkyl esters such as (meth) acrylic acid 2-ethylhexyl; monoethyl maleate, diethyl maleate, monobutyl maleate, dibutyl maleate, monoethyl fumarate, diethyl fumarate, monobutyl fumarate , Dibutyl fumarate, monocyclohexyl fumarate, Monoesters and diesters of α, β-ethylenically unsaturated polyvalent carboxylic acids such as dicyclohexyl malate, monoethyl itaconate, diethyl itaconate, monobutyl itaconate, dibutyl itaconate; methoxyethyl (meth) acrylate, (meth) Alkoxyalkyl esters of α, β-ethylenically unsaturated carboxylic acids such as methoxypropyl acrylate, butoxyethyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, etc. Hydroxyalkyl esters of α, β-ethylenically unsaturated carboxylic acids; divinyl compounds such as divinylbenzene; di (meth) acrylates such as ethylene di (meth) acrylate, diethylene glycol di (meth) acrylate, and ethylene glycol di (meth) acrylate In addition to polyfunctional ethylenically unsaturated monomers such as trimethyrolpropane tri (meth) acrylate; N-methylol (meth) acrylamide, N, N'- And self-crosslinking compounds such as dimethylol (meth) acrylamide.
Among these, by using an unsaturated epoxide compound, it may be possible to further improve the gasoline permeability resistance of the obtained rubber cross-linked product.

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 40-160. 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 processability of the nitrile copolymer rubber composition may be deteriorated.

Method for Producing Nitrile Copolymer Rubber (A) The method for producing nitrile copolymer rubber (A) is not particularly limited, and the respective monomers constituting nitrile copolymer rubber (A) described above are copolymerized. Any method can be used. 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 such as sodium dodecylbenzenesulfonate, or dispersion of polyvinyl alcohol or the like. A suspension polymerization method (including a fine suspension polymerization method) for obtaining a latex of a copolymer having an average particle size of about 0.2 to 200 μm using an agent 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 conjugated diene monomer is referred to as “monomer (m2)”, and a cationic monomer The monomer capable of forming a body and / or cation is referred to as “monomer (m3)”.

  That is, monomer (m1) 43 to 62% by weight, preferably 45 to 58% by weight, more preferably 46 to 56% by weight, monomer (m2) 18 to 56.9% by weight, preferably 27 to 54%. 0.7 wt%, more preferably 34-53.5 wt%, and monomer (m3) 0-20 wt%, preferably 0.1-15 wt%, more preferably 0.5-10 wt% The monomer mixture (wherein the total amount of the monomer (m1), the monomer (m2) and the monomer (m3) is 100% by weight) is emulsion-polymerized, and the polymerization conversion rate is preferable. Is preferably a method of removing the unreacted monomer as desired after stopping the polymerization reaction at 50 to 95% by weight.

If the amount of the monomer (m1) used in the emulsion polymerization method is too small, the oil resistance and gasoline permeation resistance of the resulting rubber cross-linked product will deteriorate, while if too much, the cold resistance tends to deteriorate. is there. If the amount of the monomer (m2) 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 resulting rubber cross-linked product tends to have poor gasoline permeability resistance. Moreover, by using the monomer (m3) in the above range, the dispersibility of the glass flakes is improved, and the gasoline permeation resistance and the cold resistance are further improved.
Further, if the polymerization conversion rate when the polymerization reaction is stopped is too low, it becomes very difficult to recover the unreacted monomer. On the other hand, if it is too high, the normal physical properties of the resulting rubber cross-linked product will deteriorate.

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

  In the present invention, the total amount of monomers (m1) to (m3) used for emulsion polymerization may be used to initiate the polymerization reaction, but the composition distribution of each monomer unit of the copolymer to be produced is controlled. From the viewpoint of obtaining a rubber cross-linked product rich in rubber elasticity, a part of the total amount of the monomers (m1) to (m3) used for the emulsion polymerization is used to start the polymerization reaction, and then the emulsion polymerization is performed. It is preferable to polymerize by adding the remainder of the monomers (m1) to (m3) used in the reactor to the reactor. This is because, generally, if the total amount of the monomers (m1) to (m3) 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. 5 to 90% by weight, more preferably 10 to 80% by weight, particularly preferably 15 to 70% by weight, and preferably 0 to 100% by weight of the monomer (m3) used for the polymerization, more preferably 30 to A monomer mixture comprising 100% by weight, particularly preferably 70 to 100% by weight, is charged into the reactor, and after the polymerization reaction is started, the polymerization conversion rate with respect to the monomer mixture charged into the reactor is preferably 5 to 80 It is preferable to continue the polymerization reaction by adding the remaining monomer to the reactor in the range of% by weight. In addition, for example, even when the monomer (m3) is not used, the polymerization reaction is started using the above-mentioned amounts of the monomer (m1) and the monomer (m2) used for the polymerization, It is preferable to polymerize by adding the remainder of the bodies (m1) and (m2) 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) can be obtained by removing unreacted monomers using a known method such as heating distillation, vacuum distillation, steam distillation or the like. The nitrile copolymer rubber (A) can be obtained by solidifying this.

  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 120 or less, preferably 80 or less, more preferably 40 or less. 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.

Nitrile copolymer rubber composition The nitrile copolymer rubber composition of the present invention is a specific amount of glass flakes (B) having an average surface area of 1 μm ² or more on the nitrile copolymer rubber (A). In addition. By adding glass flakes (B) having an average area of 1 μm ² or more to the nitrile copolymer rubber (A), it is possible to improve the gasoline permeation blocking effect in the case of a rubber cross-linked product. Thus, the obtained rubber cross-linked product can be made excellent in gasoline permeability resistance.

  The glass flakes (B) used in the present invention are amorphous plate-like particles such as E glass or C glass. In FIG. 1, the schematic diagram of the glass flakes (B) used by this invention is shown. In FIG. 1, glass flakes (B) are represented by reference numeral “1”, and as shown in FIG. 1, glass flakes (B) are in the thickness direction (represented by reference numeral “t” in FIG. 1). It has a main surface 2 which is a substantially vertical surface and has the largest surface area among the surfaces of the glass flakes (B). In this invention, let the average area of the largest surface of the main surface 2 of each plate-shaped particle which comprises glass flakes (B) be "the average area of a main surface."

The average area of the main surface of the glass flake (B) is 1 μm ² or more, preferably 5 to 850,000 μm ² , more preferably 100 to 500,000 μm ² , and still more preferably 200 to 400,000 μm ² . Using glass flakes (B) with an average area of the main surface in the above range, and adding this to nitrile copolymer rubber (A) improves the penetration permeation effect of gasoline in the case of a rubber cross-linked product. And the resulting rubber cross-linked product can have excellent gasoline permeation resistance and sour gasoline resistance. If the average area of the main surface of the glass flake (B) is too small, the gasoline permeation resistance of the resulting rubber cross-linked product will deteriorate. On the other hand, when too large, dispersion | distribution in a nitrile copolymer rubber (A) will become difficult, and the mechanical strength of the rubber crosslinked material obtained will fall.

  The average thickness of the glass flakes (B) is preferably 0.01 to 20 μm, more preferably 0.1 to 10 μm, and still more preferably 0.9 to 8 μm. The average thickness of the glass flake (B) can be determined by averaging the thickness t of each plate-like particle constituting the glass flake (B). When the average thickness of the glass flakes (B) is in the above range, the gasoline permeation resistance is further improved.

  The average area and average thickness of the main surface of the glass flakes (B) are shown in FIG. 1 for 100 particles randomly selected with an atomic force microscope from each plate-like particle constituting the glass flakes (B). It can be obtained by measuring the area and thickness t of the main surface 2 shown in FIG.

Moreover, since the effect of this invention becomes still more remarkable, the glass flake (B) to which the surface was processed with the coupling agent is preferable. The coupling agent used for the surface treatment is not particularly limited as long as it has an organic functional group and a hydrolyzable group, but a titanate coupling agent and a silane coupling agent are preferable, and a silane coupling agent is particularly preferable.
As a method for treating the surface of glass flake (B) with a coupling agent, (a) glass flake (B) is preliminarily placed in a volatile solvent such as alcohol, toluene, etc. (B) A method in which the coupling agent easily spreads on the surface, a small amount of an alkaline solution is added to increase the reactivity, an appropriate amount of the coupling agent is added, and then the solvent is removed; ) A method in which the coupling agent is directly brought into contact with the glass flake (B) and then heat-treated at 50 ° C. to 200 ° C .; (c) Glass flake and the coupling agent are charged at the time of kneading, and the discharge temperature is 120 The method of surface-treating by controlling to -200 degreeC; etc. are mentioned, The method of said (a) is preferable. By using the method (a), it is possible to further improve elongation, gasoline permeability resistance, and compression set resistance.

  Specific examples of the coupling agent include sulfide group-containing silane coupling agents such as bis (3- (triethoxysilyl) propyl) disulfide and bis (3- (triethoxysilyl) propyl) tetrasulfide; γ-mercapto Mercapto group-containing silane coupling agents such as propyltrimethoxysilane, γ-mercaptomethyltrimethoxylane, γ-mercaptomethyltriethoxylane, γ-mercaptohexamethyldisilazane; γ-glycidoxypropyltriethoxysilane, γ- Epoxy group-containing silane couplings such as glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropyltri Methoxysilane, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltri Amino group-containing silane coupling agents such as methoxysilane; γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltris (β-methoxyethoxy) silane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyl Diethoxysilane, γ-methacryloxypropi (Meth) acryloxy group-containing silane coupling agents such as rutriethoxysilane and γ-acryloxypropyltrimethoxysilane; vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, vinyltrichlorosilane, vinyltri Vinyl group-containing silane coupling agents such as acetoxysilane; 3-chloropropyltrimethoxysilane and other chloropropyl group-containing silane coupling agents; 3-isocyanatopropyltriethoxysilane and other isocyanate group-containing silane coupling agents: p-styryl Styryl group-containing silane coupling agents such as trimethoxysilane; ureido group-containing silane coupling agents such as 3-ureidopropyltriethoxysilane; allyl group-containing silane coupling agents such as diallyldimethylsilane Silane coupling agent having only alkoxy group such as tetraethoxysilane; phenyl group-containing silane coupling agent such as diphenyldimethoxysilane; fluoro group-containing silane coupling agent such as trifluoropropyltrimethoxysilane; isobutyltrimethoxy (Cyclo) alkyl group-containing silane coupling agents such as silane and cyclohexylmethyldimethoxysilane; aluminum-based coupling agents such as acetoalkoxyaluminum diisopropylate; isopropyltriisostearoyl titanate, isopropyltris (dioctylpyrophosphate) titanate, isopropyl Tri (N-aminoethyl-aminoethyl) titanate, tetraoctyl bis (ditridecyl phosphite) titanate, tetra (2,2- Allyloxymethyl-1-butyl) bis (ditridecyl) phosphite titanate, bis (dioctylpyrophosphate) oxyacetate titanate, bis (dioctylpyrophosphate) ethylene titanate, tetraisopropylbis (dioctylphosphite) titanate, isopropyltriisostearoyl titanate And titanate coupling agents such as These can be used individually by 1 type or in combination of multiple types. Among these, an amino group, a (meth) acryloxy group and an epoxy group-containing silane coupling agent are preferable, and an epoxy group-containing silane coupling agent is particularly preferable because the effects of the present invention become more remarkable.

  The content ratio of the glass flakes (B) in the nitrile copolymer rubber composition of the present invention is 1 to 30 parts by weight, preferably 5 to 100 parts by weight with respect to 100 parts by weight of the nitrile copolymer rubber (A). 25 parts by weight, more preferably 15 to 25 parts by weight. If the blending amount of the glass flakes (B) is too small, the resulting rubber cross-linked product may have poor gasoline permeability resistance or insufficient sour gasoline resistance. On the other hand, if the blending amount is too large, the gasoline permeation resistance and elongation may decrease.

The nitrile copolymer rubber composition of the present invention preferably contains a plasticizer in addition to the nitrile copolymer rubber (A) and the glass flakes (B). As the plasticizer, those conventionally used as a plasticizer for rubber compounding can be used, and are not particularly limited. However, the SP value (solubility parameter) by the HOY method is 8 to 10.2 (cal / cm ³ ) ¹ A plasticizer that is ^{/ 2} is preferably used. If the SP value of the plasticizer is too large, the resulting rubber cross-linked product tends to be inferior in cold resistance. On the other hand, if it is too small, the gasoline permeation resistance of the resulting rubber cross-linked product tends to deteriorate.

Specific examples of such plasticizers (SP value is “(cal / cm ³ ) ^1/2 ”) include, for example, dibutoxyethyl adipate (SP value: 8.8), di (butoxy adipate) An ester compound of adipic acid and an ether bond-containing alcohol such as (ethoxyethyl) (SP value: 9.2); an azelaic acid such as dibutoxyethyl azelate and azelaic acid di (butoxyethoxyethyl) and an ether bond-containing alcohol Ester compound; ester compound of sebacic acid such as dibutoxyethyl sebacate, di (butoxyethoxyethyl) sebacate and ether-containing alcohol; phthalic acid such as dibutoxyethyl phthalate, di (butoxyethoxyethyl) phthalate Ester compound with alcohol containing ether bond; Ester compounds of isophthalic acid such as xylethyl, di (butoxyethoxyethyl) isophthalate and alcohols containing an ether bond; di- (2-ethylhexyl) adipate (SP value: 8.5), diisodecyl adipate (SP value: 8) .3), adipic acid dialkyl esters such as diisononyl adipate and dibutyl adipate (SP value: 8.9); di- (2-ethylhexyl) azelate (SP value: 8.5), diisooctyl azelate, azelain Azelaic acid dialkyl esters such as di-n-hexyl acid; sebacin such as di-n-butyl sebacate (SP value: 8.7), di- (2-ethylhexyl) sebacate (SP value: 8.4) Acid dialkyl esters; 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), diisodecyl phthalate (SP value: 8.5), diundecyl phthalate (SP value) 8.5), dialkyl non-phthalates such as diisononyl phthalate (SP value: 8.9); dicycloalkyl phthalates such as dicyclohexyl phthalate; diphenyl phthalate, butylbenzyl phthalate (SP value: 10.2) phthalic acid aryl esters; isophthalic acid di- (2-ethylhexyl), isophthalic acid dialkyl esters such as diisooctyl isophthalic acid; tetrahydrophthalic acid di- (2-ethylhexyl), tetrahydrophthalic acid di-n -Tetrahydro solvents such as octyl and diisodecyl tetrahydrophthalate Dialkyl esters of triacids; tri- (2-ethylhexyl) trimellitic acid (SP value: 8.9), tri-n-octyl trimellitic acid (SP value: 8.9), triisodecyl trimellitic acid (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; epoxy plasticizers such as epoxidized soybean oil (SP value: 9.0), epoxidized linseed oil (SP value: 9.3); phosphorus such as tricresyl phosphate (SP value: 9.7) And acid ester plasticizers. These can be used individually by 1 type or in combination of multiple types.

  Among these, since the cold resistance and gasoline permeation resistance of the resulting rubber cross-linked product can be improved, dibasic acids such as adipic acid, azelaic acid, sebacic acid and phthalic acid, and an ether bond An ester compound with a contained alcohol is preferable, an ester compound with adipic acid and an ether bond-containing alcohol is more preferable, and di (butoxyethoxyethyl) adipate is particularly preferable.

  The content of the plasticizer in the nitrile copolymer rubber composition of the present invention is preferably 0.1 to 200 parts by weight, more preferably 1 to 150 parts per 100 parts by weight of the nitrile copolymer rubber (A). Part by weight, more preferably 2 to 100 parts by weight. When the content of the plasticizer is within the above range, in addition to preventing bleeding, the effect of the present invention becomes even more remarkable.

  Moreover, the nitrile copolymer rubber composition of the present invention comprises a plate-like inorganic filler other than glass flake (B), for example, kaolinites such as kaolinite and halosite; montmorillonite, beidellite, nontronite, saponite. Further, smectites such as hectorite, stevensite and mica; and vermiculites; chlorite; talc and the like may be further contained. Among these, smectites are preferable, and montmorillonite, mica, and saponite are particularly preferable.

  The amount of the plate-like inorganic filler is preferably 1 to 50 parts by weight, more preferably 5 to 40 parts by weight, still more preferably 10 to 30 parts by weight based on 100 parts by weight of the nitrile copolymer rubber (A). Parts by weight.

  Although it does not specifically limit as a manufacturing method of the nitrile copolymer rubber composition of this invention, The glass flakes (B) are used for the latex of a nitrile copolymer rubber (A) using the latex of a nitrile copolymer rubber (A). ), And a plasticizer and a plate-like inorganic filler, which are added as necessary, are added with stirring to obtain a latex composition, which is then coagulated.

  When the nitrile copolymer rubber composition of the present invention is prepared using the latex of the nitrile copolymer rubber (A), the glass flake (B) and a plasticizer added as necessary More preferably, the inorganic filler in the form of a plate is dispersed in water in advance and added to the latex of the nitrile copolymer rubber (A) as an aqueous dispersion (hereinafter, each component is in the state of latex or dispersion). Mixing is sometimes referred to as “latex blend”). By adjusting with the above latex blend, the effect of the present invention becomes more remarkable.

  Although the preparation method of the aqueous dispersion of glass flakes (B) is not particularly limited, it may be prepared by adding glass flakes (B) while vigorously stirring an aqueous medium. In this case, sodium polyacrylate, sodium tripolyphosphate, sodium hexametaphosphate, sodium pyrophosphate, sodium polymaleate, β-naphthalene sulfone in an amount of 0.1 to 10% by weight based on the glass flake (B). It is preferable to use an aqueous medium containing a dispersant such as a sodium salt of an acid / formalin condensate or a surfactant, and particularly preferably an anionic dispersant or a surfactant. These can be used individually by 1 type or in combination of multiple types. The solid content concentration of the aqueous dispersion of glass flakes (B) is preferably 1 to 50% by weight, more preferably 2 to 40% by weight.

  The method for preparing the aqueous dispersion of the plasticizer in the case of using the plasticizer is not particularly limited, but the aqueous medium containing the surfactant in an amount of 0.5 to 10% by weight of the plasticizer is vigorously stirred. However, it is preferable to prepare by adding a plasticizer. 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; and the like. In addition, it is preferable that the density | concentration of the plasticizer in an aqueous dispersion shall be 5-70 weight%.

  Further, the method for preparing the aqueous dispersion of the plate-like inorganic filler is not particularly limited, but for example, it can be prepared in the same manner as the aqueous dispersion of glass flake (B).

  The nitrile copolymer rubber composition of the present invention may further contain an acrylic resin and / or a vinyl chloride resin. By containing an acrylic resin and / or a vinyl chloride resin, ozone resistance can be further improved when a rubber cross-linked product is obtained. The content of the acrylic resin and / or vinyl chloride resin is preferably 10 to 150 parts by weight, more preferably 15 to 125 parts by weight, and still more preferably 100 parts by weight of the nitrile copolymer rubber (A). 20 to 100 parts by weight. If the content of the acrylic resin and / or the vinyl chloride resin is too small, it is difficult to obtain the addition effect. On the other hand, if too much, cold resistance may be deteriorated. The method for containing the acrylic resin and / or the vinyl chloride resin is not particularly limited. For example, a latex acrylic resin and / or vinyl chloride resin produced by emulsion polymerization is mixed with the latex composition ( Latex blend).

  The coagulation method for coagulating the latex composition to obtain the nitrile copolymer rubber composition of the present invention is not particularly limited, but known methods such as freeze coagulation, dry coagulation, coagulation with water-soluble organic liquid, salting out coagulation, etc. The method is applied. Among these, it is preferable to carry out 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, aluminum sulfate, and aluminum hydroxide. The amount of the coagulant used is preferably 0.5 to 150% by weight, particularly preferably 0.5 to 20% by weight, based on the nitrile copolymer rubber (A).

  Here, when the nitrile copolymer rubber (A) contains a cationic monomer unit and / or a monomer unit capable of forming a cation, dilute sulfuric acid is used when salting out the latex composition. It is preferable to add an aqueous solution or the like to control the pH of the aqueous coagulant solution below the isoelectric point of the latex composition of the nitrile copolymer (A). By controlling the pH of the aqueous solution of the coagulant, the zeta potential of the functional group possessed by the cationic monomer unit and the monomer unit capable of forming a cation contained in the nitrile copolymer rubber (A) is increased. Thus, the dispersibility of the glass flake (B) can be improved and the crumb particle size obtained by solidification can be increased.

  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 composition of the present invention is obtained by drying to a desired moisture content by a band dryer, a ventilated dryer, a twin screw extruder or the like generally used for rubber production. Can do. Moreover, you may perform coagulation | solidification and drying simultaneously within a twin-screw extruder.

  As a method for preparing the nitrile copolymer rubber composition of the present invention, for example, glass flake (B) is added to the latex of nitrile copolymer rubber (A), if necessary, in addition to the method described above. Plasticizers, plate-like inorganic fillers added as needed, and acrylic resins and / or vinyl chloride resins added as needed or the total amount of one or more components or It can also be obtained by solidifying and drying after containing a part thereof and kneading the remaining components with a kneading machine such as a roll or a Banbury mixer. Further, using the latex composition prepared according to the above method, coagulating and drying the latex composition, a glass flake (B), a plasticizer, a plate-like inorganic filler, and an acrylic resin and It can also be obtained by kneading vinyl chloride resin with a kneading machine such as a roll or a Banbury mixer.

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

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 obtained by the above method.
The crosslinking agent is not particularly limited as long as it is usually used as a crosslinking agent for nitrile group-containing 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 amount of these crosslinking aids and crosslinking accelerators is not particularly limited, but is 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. Additives such as fillers other than glass flakes (B), reinforcing agents, lubricants, adhesives, lubricants, processing aids, flame retardants, antifungal agents, antistatic agents, and coloring agents may be blended.

  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 glass flake (B) include carbon black, silica, calcium carbonate, aluminum silicate, magnesium silicate, calcium silicate, magnesium oxide, short fibers, zinc (meth) acrylate and (meth) acrylic acid. Examples thereof include α, β-ethylenically unsaturated carboxylic acid metal salts such as magnesium.

  Further, the nitrile copolymer rubber composition and the crosslinkable nitrile copolymer rubber composition of the present invention contain a rubber other than the nitrile copolymer rubber (A) as long as the effects of the present invention are not impaired. May be. The rubber other than the nitrile copolymer rubber (A) is not particularly limited, but acrylic rubber, ethylene-acrylic acid copolymer rubber, fluorine rubber, styrene-butadiene copolymer rubber, ethylene-propylene copolymer rubber, Mention may be made of ethylene-propylene-diene terpolymer rubber, natural rubber and polyisoprene rubber, ethylene-vinyl acetate copolymer and the like. In addition, when blending rubber other than nitrile copolymer rubber (A), the blending amount is preferably 100 parts by weight or less, more preferably 50 parts by weight with respect to 100 parts by weight of nitrile copolymer rubber (A). Hereinafter, it is particularly preferably 30 parts by weight or less.

The crosslinkable nitrile copolymer rubber composition of the present invention has a Mooney viscosity (hereinafter sometimes referred to as “compound Mooney viscosity”) (ML _{1 + 4} , 100 ° C.), preferably 5 to 300, more preferably 10 ~ 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 1 hour.

  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, sour gasoline resistance and compression set 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 layer (II) other than the layer (I) of the laminate, the α, β-ethylenically unsaturated nitrile monomer unit content is preferably 5 to 55% by weight, more preferably 18 to 45% by weight. Nitrile copolymer rubber (L), those containing nitrile copolymer rubber (L) and acrylic resin and / or vinyl chloride resin, fluorine rubber, chloroprene rubber, hydrin rubber, chlorosulfonated polyethylene rubber , Acrylic rubber, ethylene-acrylic acid copolymer, ethylene-propylene copolymer, ethylene-propylene-diene terpolymer, butyl rubber, isoprene rubber, natural rubber, styrene-butadiene copolymer, fluororesin, polyamide resin , Polyvinyl alcohol, ethylene-vinyl acetate copolymer resin, ethylene-vinyl alcohol copolymer resin, poly Naphthalate, polyphenylene sulfide, polyolefin resins, and polyester resins. These can be used individually by 1 type or in combination of multiple types.

  Moreover, in order to adhere | attach layer (I) and layer (II) as needed, you may contain a phosnium salt etc. in either / or both of layer (I) and layer (II). A new layer (III) may be used as an adhesive layer between I) and layer (II). As the layer (III), the same resin or rubber composition as the resin or rubber composition constituting the layer (II) described above can be used. As the layer (III), the resin or rubber composition constituting the layer (II) described above can be used singly or in combination, and a phosnium salt or 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. The crosslinkable nitrile copolymer rubber composition of the present invention, which is a hose of the present invention, has the property that mandrel cracks are unlikely to occur, and therefore can be produced using a mandrel.
That is, when the hose is a single layer composed only of the 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 body and crosslinking the crosslinkable nitrile copolymer rubber composition.
Alternatively, when the hose has a multilayer structure including the crosslinked product of the present invention, a layer other than the layer composed of the crosslinked nitrile copolymer rubber composition of the present invention and the crosslinked product of the present invention is formed. The resin or rubber composition to be formed is formed 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 is obtained. It can be produced by crosslinking.

  In addition to the above, the rubber cross-linked product of the present invention is suitable for seal members such as packings, gaskets, O-rings and oil seals; hoses such as oil hoses, inlet hoses, gas hoses, brake hoses, refrigerant hoses, and the like. is there. Examples of the gas of the gas hose include air, nitrogen, oxygen, hydrogen, carbon dioxide, carbon monoxide, methane, ethane, propane, dimethyl ether, and LPG.

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

The Mooney viscosity (polymer Mooney viscosity, compound Mooney viscosity) (ML _{1 + 4} , 100 ° C.) of the Mooney viscosity nitrile copolymer rubber and the crosslinkable nitrile copolymer rubber composition was measured according to JIS K6300.

Tensile strength, elongation, 100% tensile stress crosslinkable nitrile copolymer rubber composition is placed in a 15 cm long, 15 cm wide, 0.2 cm deep mold and press molded at 160 ° C. for 20 minutes while being pressed. A rubber cross-linked product was obtained. Using the obtained sheet-like rubber cross-linked product, the tensile strength, elongation and 100% tensile stress of the rubber cross-linked product were measured in accordance with JIS K6251 using a test piece punched in dumbbell shape No. 3.

The hardness- crosslinkable nitrile copolymer rubber composition was placed in a mold having a length of 15 cm, a width of 15 cm, and a depth of 0.2 cm, and press-molded at 160 ° C. for 30 minutes while applying pressure to obtain a sheet-like rubber cross-linked product. . Using the obtained sheet-like rubber cross-linked product, the hardness of the rubber cross-linked product was measured according to JIS K6251 using a durometer hardness tester type A according to JIS K6253.

A compression set cross-linkable nitrile copolymer rubber composition is press-molded at 160 ° C. for 30 minutes using a mold to obtain a cylindrical cross-linked product having a diameter of 29 mm and a thickness of 12.5 mm. It was. Then, using the obtained cylindrical cross-linked product, the distance between the two planes sandwiching the cylindrical cross-linked product was JIS compressed under the condition of holding 25% in the disk thickness direction at 120 ° C. for 70 hours. The compression set was measured according to K6262.

Gasoline permeability coefficient The same material as the sheet-like rubber cross-linked product used for the evaluation of the tensile strength, elongation, and 100% tensile stress was prepared. As fuel oil, “weight ratio of isooctane, toluene, and ethanol was 2: 2: The gasoline permeation 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).
The gasoline permeability coefficient is preferably as low as possible, and indexed with Comparative Example 1 as 100.

Sour gasoline resistance test The same sheet-like rubber cross-linked product used for the evaluation of the tensile strength, elongation and 100% tensile stress was prepared, and the fuel oil “isooctane / toluene / ethanol weight ratio 2: In a test oil in which dilauroyl peroxide is dissolved at a concentration of 3% by weight in a "2: 1 mixture", the temperature is 40 ° C for 500 hours (the test oil is exchanged for a new one at a rate of 2 times per 168 hours). The sheet-like rubber cross-linked product was immersed under the conditions of Then, a sample after 500 hours was subjected to a tensile test in accordance with JIS K6253, and the presence or absence of cracks was observed during elongation by the tensile test to evaluate the sour gasoline resistance.

Production Example 1 (Production of latex of nitrile copolymer rubber (A1))
A reaction vessel was charged with 240 parts of water, 77 parts of acrylonitrile, 3.4 parts of 2-vinylpyridine, and 2.5 parts of sodium dodecylbenzenesulfonate (emulsifier), and the temperature was adjusted to 5 ° C. Next, after depressurizing and sufficiently degassing the gas phase, 19 parts of 1,3-butadiene, 0.05 parts of paramentane hydroperoxide as a polymerization initiator, 0.02 parts of sodium ethylenediaminetetraacetate, First stage reaction of emulsion polymerization was started by adding 0.005 part of iron (7-hydrate), 0.05 part of sodium formaldehyde sulfoxylate and 0.6 part of chain transfer agent t-dodecyl mercaptan. After the start of the reaction, when the polymerization conversion ratio with respect to the charged monomer reached 26 wt%, 52 wt% and 72 wt%, respectively, 16 parts of 1,3-butadiene and 15 parts of 1,3-butadiene were added to the reaction vessel. Then, 0.2 parts of t-dodecyl mercaptan and 14 parts of 1,3-butadiene were respectively added to carry out the second and third stage and fourth stage polymerization reactions. Thereafter, when the polymerization conversion ratio with respect to all charged monomers reached 86% 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 of 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: 36% by weight, A particle size of about 100 nm) was obtained.

  A part of latex of the nitrile copolymer rubber (A1) is sampled, coagulated, washed with water and dried, and the content ratio of each monomer constituting the monomer of the obtained nitrile copolymer rubber (A1) Was measured using an FT-NMR apparatus (JNM-EX400WB) manufactured by JEOL Ltd., 48.5% by weight of acrylonitrile monomer unit, 49.2% by weight of 1,3-butadiene monomer unit, 2 -It was 2.3 weight% of vinyl pyridine monomer units. Further, the Mooney viscosity (polymer Mooney viscosity) of the nitrile copolymer rubber (A1) was 50.

Production Example 2 (Production of latex of nitrile copolymer rubber (A2))
In Production Example 1, the amount of monomer used in the first stage of the emulsion polymerization reaction was changed to 83 parts of acrylonitrile, 2.9 parts of 2-vinylpyridine, and 14.7 parts of 1,3-butadiene, and the reaction was started. Thereafter, when the polymerization conversion ratio with respect to the charged monomer reached 36% by weight, 58% by weight, and 74% by weight, respectively, 14 parts of 1,3-butadiene, 13 parts of 1,3-butadiene and t A nitrile was prepared in the same manner as in Production Example 1 except that 0.2 parts of dodecyl mercaptan and 12 parts of 1,3-butadiene were respectively added and the second, third and fourth stage polymerization reactions were carried out. A latex (solid content: 36% by weight) of copolymer rubber (A2) 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 Production Example 1, 54.3% by weight of acrylonitrile monomer unit, 2-vinylpyridine It was 2.3% by weight and 1,3-butadiene unit was 43.4% by weight. Further, the Mooney viscosity (polymer Mooney viscosity) of the nitrile copolymer rubber (A2) was 60.

Production Example 3 (Production of latex of nitrile copolymer rubber (A3))
In Production Example 1, the amount of monomer used in the first stage of the emulsion polymerization reaction was changed to 80 parts of acrylonitrile, 3.1 parts of 2-vinylpyridine and 16.9 parts of 1,3-butadiene, and the reaction was started. Thereafter, when the polymerization conversion ratio with respect to the charged monomer reached 31% by weight, 56% by weight, and 73% by weight, respectively, 15 parts of 1,3-butadiene, 14 parts of 1,3-butadiene and t -Nitrile in the same manner as in Production Example 1 except that 0.2 parts of dodecyl mercaptan and 13 parts of 1,3-butadiene were added and the second and third stage and fourth stage polymerization reactions were carried out. A latex (solid content: 36% by weight) of copolymer rubber (A3) was obtained.

  When the content ratio of each monomer unit constituting the obtained nitrile copolymer rubber (A3) was measured in the same manner as in Production Example 1, 50.1% by weight of acrylonitrile monomer unit, 2-vinylpyridine It was 2.4% by weight and 1,3-butadiene unit was 47.5% by weight. The Mooney viscosity (polymer Mooney viscosity) of the nitrile copolymer rubber (A3) was 48.

Production Example 4 (Production of latex of nitrile copolymer rubber (A4))
The amount of the charged monomer used in the first stage of the emulsion polymerization reaction was changed to 83 parts of acrylonitrile and 15 parts of 1,3-butadiene, and after the start of the reaction, the polymerization conversion ratio with respect to the charged monomer was 40% by weight, 60%. When the respective weight percentages were reached, 14 parts of 1,3-butadiene, 25 parts of 1,3-butadiene and 0.2 parts of t-dodecyl mercaptan were added to the reaction vessel, respectively. A latex of nitrile copolymer rubber (A4) (solid content: 36% by weight) was obtained in the same manner as in Production Example 1 except that the polymerization reaction of the second stage was performed.

  When the content ratio of each monomer unit constituting the obtained nitrile copolymer rubber (A4) was measured in the same manner as in Production Example 1, acrylonitrile monomer unit was 48.5% by weight, 1,3- The butadiene unit was 51.5% by weight. The Mooney viscosity (polymer Mooney viscosity) of the nitrile copolymer rubber (A4) was 52.

Example 1
Surface treatment of plate-like filler First, a solution prepared by adding 1 part of 1N KOH aqueous solution to 50 parts of ethanol was prepared, and glass flakes (trade name: REF-015, made by Nippon Sheet Glass, average area of main surface) were prepared in this solution. (225 μm ² , thickness 5 μm) 100 parts were added, and the whole solution was allowed to spread while stirring. Further, 20 parts of a silane coupling agent (γ-glycidoxypropyltriethoxysilane) was added and stirred so as to reach the whole. Next, it was naturally dried for one day, put in a vacuum dryer at 130 ° C., heat-treated for 30 minutes, and gradually cooled until the temperature reached room temperature, to obtain surface-treated glass flakes (B1). It was 7% when the heat loss of the surface treatment glass flakes was measured with TGA (thermogravimetry apparatus).

Preparation of nitrile copolymer rubber composition 100 parts of the surface-treated glass flakes (B1) prepared above were added to a mixture of distilled water and 5 parts of sodium polyacrylate and stirred vigorously to obtain a solid content concentration of 5%. An aqueous dispersion of the surface-treated glass flake (B1) was obtained.

  Further, di (butoxyethoxyethyl) adipate (trade name “Adekasizer RS-107”, manufactured by Asahi Denka Kogyo Co., Ltd.) as a plasticizer and potassium oleate as an emulsifier are used in an amount of 2% by weight of the plasticizer. A 50 wt% aqueous emulsion of di (butoxyethoxyethyl) adipate was prepared by vigorous stirring in water.

  Then, while stirring the latex of the nitrile copolymer rubber (A1) obtained in Production Example 1 in a container, the aqueous dispersion of the surface-treated glass flakes (B1) prepared above is added and dispersed. It was. The aqueous dispersion of the surface-treated glass flake (B1) is 20 parts of the surface-treated glass flake (B1) with respect to 100 parts of the latex solid content (nitrile copolymer rubber amount) of the nitrile copolymer rubber (A1). The solid content (nitrile copolymer rubber and glass flake) concentration was 15%.

Subsequently, di (butoxyethoxy) adipate prepared above was added to 100 parts of the nitrile copolymer rubber (A1) in a solution in which the surface-treated glass flakes (B1) were dispersed in the nitrile copolymer rubber (A1). 20 parts of an aqueous emulsion containing (ethyl) was added and mixed and dispersed to obtain a nitrile copolymer latex composition. 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. Into the solution, a 10% dilute sulfuric acid was added as needed to adjust the pH so that the pH of the aqueous solution during coagulation was below the isoelectric point, and the solution was poured and coagulated with stirring to give a nitrile copolymer rubber ( A crumb consisting of a mixture of A1), surface treated glass flakes (B1) and a plasticizer was produced.
The obtained crumb was separated by filtration, washed with water, and then dried under reduced pressure at 60 ° C. to obtain a nitrile copolymer rubber composition.

Preparation of crosslinkable nitrile copolymer rubber composition Next, using a Banbury mixer, 100 parts of nitrile copolymer rubber (A1) in the nitrile copolymer rubber composition was mixed with FEF carbon black (Seast SO, Tokai). 20 parts by carbon), 5 parts of zinc white as a crosslinking aid and 1 part of stearic acid, 2,2,4-trimethyl-1,2-dihydroquinoline polymer (anti-crack 224, emerging from Ouchi) as an anti-aging agent And 2 parts of N-isopropyl-N′-phenyl-p-phenylenediamine (NOCRACK 810NA, manufactured by Ouchi Shinsei Chemical Co., Ltd.) as an anti-aging agent were added at 50 ° C. Mixed. Then, when the temperature reaches approximately 160 ° C., the mixture is transferred to a roll, and 0.5 parts of 325 mesh sulfur and tetramethylthiuram disulfide (Noxeller TT, manufactured by Ouchi Shinsei Chemical Co., Ltd.) 1.5 which are crosslinking agents are transferred. And 1.5 parts of N-cyclohexyl-2-benzothiazolylsulfenamide (Noxeller CZ, manufactured by Ouchi Shinsei Chemical Co., Ltd., crosslinking accelerator) and kneaded at 50 ° C. A combined rubber composition was prepared.

  About the Mooney viscosity (compound Mooney viscosity) of the obtained crosslinkable nitrile copolymer rubber composition, and the rubber crosslinked product obtained by crosslinking the composition, tensile strength, elongation, 100% tensile stress, Each evaluation of hardness, compression set rate, gasoline permeability coefficient, and sour gasoline resistance was performed. The results are shown in Table 1.

Example 2
A crosslinkable nitrile copolymer rubber composition was prepared and evaluated in the same manner as in Example 1 except that the amount of the surface-treated glass flake (B1) was changed from 20 parts to 10 parts. It was. The results are shown in Table 1.

Example 3
Instead of the glass flakes used in Example 1, glass flakes (trade name: REF-160, manufactured by Nippon Sheet Glass, average surface area of main surface 25,600 μm ² , thickness 5 μm) were used in the same manner as in Example 1, Surface treatment was performed with a silane coupling agent (γ-glycidoxypropyltriethoxysilane) to obtain surface-treated glass flakes (B2). A crosslinkable nitrile copolymer rubber composition was prepared and evaluated in the same manner as in Example 1 except that the surface-treated glass flake (B2) was used. The results are shown in Table 1.

Example 4
Instead of the glass flakes used in Example 1, glass flakes (trade name: REF-600, manufactured by Nippon Sheet Glass, average surface area of 360,000 μm ² , thickness 5 μm) were used in the same manner as in Example 1, Surface treatment was performed with a silane coupling agent (γ-glycidoxypropyltriethoxysilane) to obtain surface-treated glass flakes (B3). A crosslinkable nitrile copolymer rubber composition was prepared and evaluated in the same manner as in Example 1 except that the surface-treated glass flakes (B3) were used. The results are shown in Table 1.

Example 5
In preparing the cross-linkable nitrile copolymer rubber composition, 70 parts of the nitrile copolymer rubber (A1) is used with a latex of vinyl chloride resin (the amount of the vinyl chloride resin is 30 parts, the vinyl chloride monomer is A crosslinkable nitrile copolymer rubber composition was prepared in the same manner as in Example 3, except that the average degree of polymerization was 900) and the plasticizer content was changed from 10 parts to 30 parts. Then, the evaluation was performed in the same manner. The results are shown in Table 1.

Example 6
In preparing the crosslinkable nitrile copolymer rubber composition, the acrylic resin latex (the amount of the acrylic resin is 30 parts, the number average molecular weight is 600,000, based on 70 parts of the nitrile copolymer rubber (A1). Crosslinkability in the same manner as in Example 3, except that methyl methacrylate and acrylonitrile were copolymerized at a weight ratio of 80:20) and the amount of plasticizer was changed from 10 parts to 30 parts. A nitrile copolymer rubber composition was prepared and evaluated in the same manner. The results are shown in Table 1.

Examples 7-9
Instead of the latex of the nitrile copolymer rubber (A1), the latex of the nitrile copolymer rubber (A2) obtained in Production Example 2 (Example 7) and the nitrile copolymer obtained in Production Example 3, respectively. Crosslinking in the same manner as in Example 3 except that the latex of rubber (A3) (Example 8) and the latex of nitrile copolymer rubber (A4) obtained in Production Example 4 (Example 9) were used. A nitrile copolymer rubber composition was prepared and evaluated in the same manner. The results are shown in Table 1.

Example 10
Instead of 20 parts of surface-treated glass flakes (B2), 20 parts of glass flakes not subjected to surface treatment (trade name: REF-160, manufactured by Nippon Sheet Glass, average surface area of main surface 25,600 μm ² , thickness 5 μm) are used, Each composition was prepared and evaluated in the same manner as in Example 9 except that 1.4 parts of γ-glycidoxypropyltriethoxysilane was added during kneading in a Banbury mixer. The results are shown in Table 1.

Example 11
A rubber composition was prepared in the same manner as in Example 10 except that γ-glycidoxypropyltriethoxysilane was not used. The results are shown in Table 1.

Comparative Example 1
Crosslinkable nitrile copolymer rubber composition in the same manner as in Example 1 except that the surface-treated glass flake (B1) was not added, and in addition to 20 parts of FEF carbon black, 15 parts of MT carbon black was used. Were prepared and evaluated in the same manner. The results are shown in Table 1.

Comparative Example 2
Instead of 20 parts of surface-treated glass flakes (B2), 50 parts of glass flakes not subjected to surface treatment (trade name: REF-160, manufactured by Nippon Sheet Glass, average surface area of main surface 25,600 μm ² , thickness 5 μm) were used. Except for the above, a crosslinkable nitrile copolymer rubber composition was prepared in the same manner as in Example 3. The results are shown in Table 1.

Comparative Example 3
Latex blending was not performed, and a surface treatment was performed on 100 parts of nitrile copolymer rubber (A5) (N220S, manufactured by JSR Corporation, acrylonitrile unit content 40.1%, Mooney viscosity 52) using a Banbury mixer. Glass flakes (trade name: REF-160, manufactured by Nippon Sheet Glass, average surface area 25,600 μm ² , thickness 5 μm) 20 parts, 1.4 parts of γ-glycidoxypropyltriethoxysilane, adipic acid diacid 10 parts of (butoxyethoxyethyl), 20 parts of FEF carbon black (Shiest SO, manufactured by Tokai Carbon Co., Ltd.), 5 parts of zinc white as a crosslinking aid and 1 part of stearic acid, 2,2,4-trimethyl as an anti-aging agent -1,2-dihydroquinoline polymer (NOCRACK 224, manufactured by Ouchi Shinsei Chemical Co., Ltd.), 2 parts N- isopropyl -N'- phenyl -p- phenylenediamine as inhibitor were mixed with (NOCRAC 810NA, Ouchi made Shinko Chemical Industry Co., Ltd.) added to 50 ° C. 2 parts. Then, when the temperature reaches approximately 160 ° C., the mixture is transferred to a roll, and 0.5 parts of 325 mesh sulfur and tetramethylthiuram disulfide (Noxeller TT, manufactured by Ouchi Shinsei Chemical Co., Ltd.) 1.5 which are crosslinking agents are transferred. And 1.5 parts of N-cyclohexyl-2-benzothiazolylsulfenamide (Noxeller CZ, manufactured by Ouchi Shinsei Chemical Co., Ltd., crosslinking accelerator) and kneaded at 50 ° C. A combined rubber composition was prepared.

About the Mooney viscosity (compound Mooney viscosity) of the obtained crosslinkable nitrile copolymer rubber composition, and the rubber crosslinked product obtained by crosslinking the composition, tensile strength, elongation, 100% tensile stress, Each evaluation of hardness, compression set rate, gasoline permeability coefficient, and sour gasoline resistance was performed. The results are shown in Table 1.

Comparative Example 4
Instead of surface-treated glass flakes (B2), kaolin (average surface area of 0.64 μm ² , Hydrite PX, manufactured by Takehara Chemical Co., Ltd.) is used, and γ-glycidoxypropyltriethoxysilane is used as a Banbury mixer. A crosslinkable nitrile copolymer rubber composition was prepared in the same manner as in Example 9 except that it was added at the time of kneading and evaluated in the same manner. The results are shown in Table 1.

Comparative Example 5
Instead of surface-treated glass flakes (B2), mica (B-82, manufactured by Yamaguchi Mica Industry Co., Ltd., average area of about 32,400 μm ² ) is used, and γ-glycidoxypropyltriethoxysilane is used. A crosslinkable nitrile copolymer rubber composition was prepared in the same manner as in Example 9 except that it was not, and evaluated in the same manner. The results are shown in Table 1.

  In Table 1, “GF” in the type of filler indicates glass flake, and “CB” indicates MT carbon black. Further, “pre-treatment” in the blending method of the silane coupling agent means that the filler (glass flake) was surface-treated in advance using the silane coupling agent, and “post-addition” means the silane coupling agent. This means that the silane coupling agent was blended at the time of mixing with a Banbury mixer without surface treatment in advance.

From Table 1, the rubber cross-linked product obtained by adding a specific amount of glass flakes having an average surface area of 1 μm ² or more to the nitrile copolymer rubber composition and cross-linking this is gasoline permeability coefficient (index) And sour gasoline resistance and compression set resistance were excellent (Examples 1 to 11).
If glass flakes are not used and the requirements of the present invention are not satisfied, the gasoline permeation resistance, sour gasoline resistance and compression set resistance are insufficient (Comparative Example 1).
When the requirements of the present invention were not satisfied because the amount of glass flakes was too large, the strength was significantly reduced and the compression set rate was also deteriorated (Comparative Example 2). Further, in Comparative Example 2, since the contents leaked all the way out during the measurement of the gasoline permeability coefficient, the gasoline permeability coefficient became unmeasurable on the way. This is presumably because the glass flakes caused cracks in the rubber when the rubber swelled.

Further, when the content of the α, β-ethylenically unsaturated nitrile monomer unit in the nitrile copolymer rubber is too small to satisfy the requirements of the present invention, gasoline permeation resistance and sour gasoline resistance (Comparative Example 3).
If glass flakes are not used and the requirements of the present invention are not satisfied, even if kaolin is blended, the gasoline permeation resistance and sour gasoline resistance are poor (Comparative Example 4).
Moreover, if glass flakes are not used and the requirements of the present invention are not satisfied, even if mica is blended, the compression set resistance and gasoline permeability resistance are poor (Comparative Example 5).

FIG. 1 is a schematic view of a glass flake (B) used in the present invention.

Claims (7)

A nitrile copolymer rubber (A) having 43 to 60% by weight of an α, β-ethylenically unsaturated nitrile monomer unit and a glass flake (B) having an average surface area of 1 μm ² or more. And
The nitrile copolymer rubber composition whose content rate of the said glass flakes (B) is 1-30 weight part with respect to 100 weight part of said nitrile copolymer rubber (A).   The nitrile copolymer rubber composition according to claim 1, wherein the glass flakes (B) are surface-treated with a coupling agent.   The nitrile copolymer rubber (A) further has a cationic monomer unit and / or a monomer unit capable of forming a cation, and the cationic monomer unit in the nitrile copolymer rubber (A) The nitrile copolymer rubber composition according to claim 1 or 2, wherein a content ratio of the monomer unit and / or the monomer unit capable of forming a cation is 0.1 to 20% by weight.   The nitrile copolymer rubber composition according to any one of claims 1 to 3, further comprising a plasticizer.   The nitrile copolymer according to any one of claims 1 to 4, further comprising 10 to 150 parts by weight of a vinyl chloride resin and / or an acrylic resin with respect to 100 parts by weight of the nitrile copolymer rubber (A). Combined rubber composition.   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 5.   A rubber cross-linked product obtained by cross-linking the cross-linkable nitrile copolymer rubber composition according to claim 6.

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