WO1998044038A1 - Oil-resistant rubber composition and composite of said composition with fibers - Google Patents

Abstract

An oil-resistant rubber composition characterized by comprising a carboxylated, highly saturated nitrile copolymer rubber having an acid equivalent of 2x10-3 ephr or higher, a Mooney viscosity of 15 to 200, and an iodine value of 80 or lower and a polyvinyl chloride resin. A rubber product obtained by cross-linking this rubber composition has improved strength properties.

Description

 Specification

 Oil-resistant rubber composition and composite of the composition and fiber

Technical field

 The present invention relates to a rubber composition obtained by blending a vinyl chloride resin with a carboxylated nitrile group-containing highly saturated copolymer rubber. More specifically, the present invention has improved kneading and dispersing properties of the nitrile group-containing highly saturated copolymer rubber and a vinyl chloride resin and excellent extrudability, and further comprises gasoline, sour gasoline and engine oil. The present invention relates to a rubber composition which provides a crosslinked rubber product having excellent heat resistance, ozone resistance, compression distortion resistance and oil resistance.

Background art

 Conventionally, a rubber composition obtained by mixing an acrylonitrile-butadiene copolymer rubber (NBR) and a vinyl chloride resin has been known as a rubber composition for providing a crosslinked rubber product having oil resistance and ozone resistance. .

 In addition, the mixture of partially hydrogenated acrylonitrile-butadiene copolymer rubber (HNBR) and vinyl chloride resin has an excellent balance of oil resistance and cold resistance, and has a conventional level of ozone resistance and sour gasoline resistance. It has also been reported that crosslinked rubber products that surpass the standard are given (Japanese Patent Publication No. 60-49218).

However, the performance requirements of rubber products in recent years have become increasingly sophisticated, especially in the fields of belts, hoses and diaphragms, in addition to strength properties, other physical properties such as heat resistance, oil resistance, and nylon cord. It has been desired to further improve the adhesion to fibers such as described above. Conventional techniques are not sufficient to meet these demands, and need to be further improved. An object of the present invention is to provide a rubber composition comprising a nitrile group-containing highly saturated copolymer rubber and a vinyl chloride resin, wherein the crosslinked rubber has improved strength properties and the like by being crosslinked with a crosslinking agent or the like. A rubber composition, which can provide the product, will be provided.

 As a result of intensive studies, the present inventor has found that a rubber composition comprising a carboxylated nitrile group-containing highly saturated copolymer rubber and a vinyl chloride resin has a crosslinked structure having improved tensile strength as compared with the prior art. We found that we provided rubber products and completed the present invention based on this finding.

Disclosure of the invention

 Thus, according to the present invention,

 (1) Polyvinyl chloride resin on carboxylated nitrile group-containing highly saturated copolymer rubber with acid equivalent of 2 X 10-3 ephr or more, Mooney viscosity of 15 to 200, and iodine value of 80 or less An oil-resistant rubber composition comprising:

 (2) A composite of the oil-resistant rubber composition of (1) and a fiber.

 (3) The composite according to the above (2), which is used for a hose.

 (4) The composite according to (2) above, which is used for a diaphragm.

Is provided.

 The carboxylated nitrile group-containing highly saturated copolymer rubber used in the present invention is a copolymer having a nitrile group in the molecule, having few carbon-carbon unsaturated bonds, and exhibiting rubber elasticity. Thus, it further has a carboxyl group in the molecule.

The amount of carbon-carbon unsaturated bonds is alternatively expressed by the iodine value. The carboxylated nitrile group-containing highly saturated copolymer rubber used in the present invention has an iodine value of 80 or less, preferably 60 or less. High iodine value If a crosslinker is used, the oil resistance and heat resistance of the crosslinked product decrease. The content of the binding nitrile unit of the rubber is not particularly limited, but is usually

It is 10 to 60% by weight, preferably 15 to 40% by weight. In addition, the content of the bound nitrile unit is a value determined by the Geldar method. Oil content and heat resistance increase as the content of the binding nitrile unit increases, and the rubber elasticity increases as the content of the binding nitrile unit decreases. Therefore, it is appropriately selected according to the application.

Acid equivalent of your rubbers, 2 xl 0- ³ ephr or more, preferably 2 x 10 one ³ ~ 5 x 10- ² ephr, more preferably ^{5 x 10- 3 ~3 xl 0- 2} ephr. If the acid equivalent is too small, the compatibility with the vinyl chloride resin is not improved, which is not preferable.

 The acid equivalent is determined by dissolving the rubber in acetone, reprecipitating and refining with n-hexane, and re-dissolving the resulting reprecipitated purified rubber in acetone. This value was obtained by titration using ethanol solution of thymol with thymolphthalein as an indicator.

The rubber has a Mooney viscosity (ML = ₄ , 100 ° C.) of 15 to 200, preferably 30 to 150. If the Mooney viscosity is too high, the kneading processability deteriorates, while if it is too low, the durability under high pressure is insufficient, and the compression set and crushing (compression relaxation) become insufficient.

Further, the rubber has a methylethylketone insoluble content of usually 3% by weight or less, preferably 2% by weight or less, more preferably 1% by weight or less (ie, substantially gel-free). . If the methylethyl ketone insolubles increase, the dispersibility of the vinyl chloride resin in the rubber becomes difficult. The content of the insoluble matter in methyl ethyl ketone was determined by chopping the rubber finely, placing it in an 80 mesh wire mesh basket, immersing this basket in methyl ethyl ketone at room temperature for 48 hours, and remaining in the basket. The solid content is dried, the weight of the dried product is measured, and the weight of the dried product is expressed as a percentage of the weight of the rubber initially placed in the basket.

 The method for producing the carboxylated nitrile group-containing highly saturated copolymer rubber used in the present invention is not particularly limited, but is usually a radical addition method in the presence of a radical generator, or an enzymatic method at a high temperature. There is a type addition method. As a preferred method, in a heated closed kneader, a nitrile group-containing highly saturated copolymer rubber and an ethylenically unsaturated carboxylic acid or an anhydride thereof are mixed at a rubber temperature of 200 to 280 ° C. And a method of performing an enzymatic addition reaction.

The nitrile group-containing highly saturated copolymer rubber used in the ene-type addition reaction is obtained by hydrogenating a conjugated gen unit of an ethylenically unsaturated nitrile-conjugated gen-based copolymer rubber. The nitrile group-containing highly saturated copolymer rubber has a bound nitrile unit content of usually 10 to 60% by weight, preferably 15 to 40% by weight, and an iodine value of usually It is 80 or less, preferably 60 or less, and its viscosity (ML! ₊₄ , 100 ° C) is usually 30 to 300, preferably 50 to 200, More preferably, it is 60 to 150.

As the iodine value increases, heat resistance and strength decrease. The lower limit of the iodine value is not particularly limited. However, if the iodine value is excessively low, crosslinking may be difficult. Therefore, generally, an iodine value of at least 1 is used. If the Mooney viscosity is too low, the durability under high pressure will be insufficient, and the compression set and Blur (compression relaxation) is not improved. Also, when the Mooney viscosity increases, the processability during kneading deteriorates. -The ethylenically unsaturated nitrile-1 conjugated gen-based copolymer used for producing the nitrile group-containing highly saturated copolymer rubber usually contains ethylenically unsaturated nitrile and conjugated gen. It is obtained by polymerizing a monomer mixture.

 Specific examples of ethylenically unsaturated nitriles include ethylenically unsaturated nitriles such as acrylonitrile, methacrylonitrile, black acrylonitrile, and methacrylonitrile. And saturated nitrile. Of these, acrylonitrile is preferably used. The amount of ethylenically unsaturated nitrile is usually from 10 to 60% by weight in the monomer mixture.

 Specific examples of the conjugated diene include 1,3-butadiene, 2,3-dimethylbutadiene, isoprene, 1,3-pentadiene, and chloroprene. Of these, 1,3-butadiene is preferably used. The amount of synergist is usually between 40 and 90% by weight in the monomer mixture. When 1,3-butadiene and isoprene are used in combination as the conjugated gen (ie, in the case of isoprene-butadiene-acrylonitrile copolymer rubber), the bond 1,3-butadiene in the conjugated gen unit is usually used. The unit content is 30 to 70% by weight, and the bound isoprene unit content is 70 to 30% by weight.

 The nitrile group-containing highly saturated copolymer rubber contains, in its structure, an ethylenically unsaturated nitrile and an ethylenically unsaturated monomer unit copolymerizable with a conjugated diene in a range of 0 to 50% by weight. It may be.

Ethylenic unsaturated mono copolymerizable with unsaturated nitriles and conjugated gens. 98/44038 Examples of polymers include vinyl aromatic compounds such as styrene and monomethylstyrene;

Methyl acrylate, ethyl acrylate, butyl acrylate, propyl acrylate, methyl methacrylate, methyl methacrylate, butyl methacrylate, methacrylate propyl, dimethyl maleate, maleate Getyl phosphate, dipropyl maleate, di-n-butyl maleate, diisobutyl maleate, di-n-pentyl maleate, di-n-hexyl maleate, di-2-ethyl ethyl maleate Hexyl, dimethyl fumarate, getyl fumarate, dipropyl fumarate, di-n-butyl fumarate, diisobutyl fumarate, di-n-pentyl fumarate, di-n-hexyl fumarate, hexyl, di-1-ethyl fumarate Hexyl, dimethyl itaconate, getyl itaconate, dipropyl itaconate, di-n-butyl itaconate Diisobutyl itaconate, di-n-pentyl itaconate, di-n-hexyl itaconate, di-2-ethyl hexyl itaconate, dimethyl citrate, dimethyl citrate, dipropyl citrate, dipropyl citrate, dipropyl citrate N-butyl, diisobutyl citraconic acid, di-n-pentyl citraconic acid, di-n-hexyl citraconic acid, di-2-ethylhexyl citraconic acid, dimethyl mesaconate, getyl mesaconate, mesacon Dipropyl methacrylate, di-n-butyl mesaconic acid, diisobutyl mesaconic acid, di-n-pentyl mesaconic acid, di-n-hexyl mesaconic acid, di-2-ethyl mesaconic acid, dimethyl glutaconate, dimethyl glutaconate , Dipropyl glutaconate, di-n-butyl glutaconate, di glutaconate Sobuchiru, glutaconic Sanjiichi n- pentyl, hexyl glutaconic di n- hexyl, into glutaconic Sanjiichi 2 Echiru, Arirumaron acid dimethyl Tyl, geryl arylmalonate, dipropyl arylmalonate, di-n-butyl arylmalonate, diisobutyl arylmalonate, di-n-hexyl arylmalonate —pentyl, di-n-hexyl arylmalonate, di-2-ethylarylmalonate, di-2-ethylhexyl hexyl, terraconic acid Dimethyl, teraconic acid getyl, teraconic acid dipropyl, teraconic acid di-n-butyl, teraconic acid di_n-pentyl, teraconic acid di-n-hexyl, teraconic acid di-2-ethyl hexyl Ethylenically unsaturated carboxylic acid alkyl esters such as;

 Ethylenically unsaturated carboxylic acid alkoxyalkyl esters such as methoxyacrylate, ethoxychelaterate, methoxyethoxylate;

 α— and / 3—cyanoethyl acrylate, <¾ _,; 3— and arcyanopropyl acrylate, cyanobutyl acrylate, cyanoethyl acrylate, <¾ and ^ cyanoethyl methacrylate, α—, / 3—and ethyl cyano-unsaturated carboxylic acid cyano-substituted alkyl esters such as and cyanopropyl methacrylate, cyanobutyl methacrylate, and cyanooctyl methacrylate;

 2-ethylenoxyunsaturated carboxylate, such as 2-hydroxypropyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, or hydroxypropyl methacrylate Group-substituted alkyl esters;

Acrylamide, methylacrylamide, Ν—methylolacrylamide.., Ν—dimethylolacrylamide, Ν—ethoxymethylacrylamide, Ν—methylolmethacrylamide, Ν, Ν—dimethylolmethacrylate Ethylenic unsaturated amides such as rilamide and N-ethoxymethyl methacrylamide;-Non-conjugated gens such as vinylnorbornene, dicyclopentene, 1,4-hexadiene: ethylenically unsaturated carboxylic acid fluoroalkyl esters;

And the like.

 Specific examples of the ethylenically unsaturated nitrile-conjugated gen-based copolymer rubber include acrylonitrile-butadiene copolymer rubber (NBR), acrylonitrile-butadiene-isoprene copolymer rubber (NBIR), and Lilo nitrile / isoprene copolymer rubber (NIR), acrylonitrile / butadiene / butadiene copolymer rubber, acrylonitrile / butadiene / acrylic acid copolymer rubber, acrylonitrile / butadiene / methacrylic acid copolymer rubber Rubber and the like. Of these, NBR is preferably used.

 Such an ethylenically unsaturated nitrile-conjugated copolymer rubber is usually prepared by adding an ethylenically unsaturated nitrile and a conjugated diene in the presence of a radical polymerization initiator, if necessary, using a molecular weight modifier as necessary. It is prepared by copolymerizing with other ethylenically unsaturated monomers as required. As the radical polymerization initiator to be used,

 Persulfates such as potassium persulfate, ammonium persulfate, etc .;

4,4-azobis (4-cyanovaleric acid), 2,2-azobis (2-amidinopropane) dihydrochloride, 2,2-azobis-l-methyl-N-l, l-bis (hydroxymethyl) 1-2 —Hydroxitytyl propioamide, 2, 2 '—azobis (2,4-dimethylvaleronitrile), 2, 2' — Azo compounds such as azobisisobutyronitrile, 1,1'-azobis (1-cyclohexanyl propylonitrile), etc .;-methylethyl peroxide, cupramoxide, di-t-butyl va- Oxide, acetyl peroxide, dicumyl peroxide, lauroyl peroxide, benzoyl peroxide, t-butyl peroxide 2-ethyl hexanoate, di-isopropyl alcohol peroxide, di-t-butyl peroxide Peroxides such as xysisophthalate; and the like. Also, a redox initiator obtained by combining these polymerization initiators and a reducing agent can be used.

 The amount of the polymerization initiator is usually 0.05 to 3 parts by weight based on 100 parts by weight of the monomer mixture. The polymerization temperature varies depending on the type of the initiator, but is usually from 0 to 100 ° C.

Examples of the molecular weight regulator include 2,2 ', 4,6,6'-pentamethylheptane-1-thiol, 2,4,4-trimethylpentane-12-thiol, dodecane-12-thiol, 2,2, Alkylthiol compounds such as 6,6-tetramethylheptane-14-methanethiol, 2,4,6-trimethylnonane-14-thiol; dimethylxanthogen disulfide, getylxanthogen disulfide, diisopropylxanthogen disulfide Xanthogen disulfides such as thiuram disulfides such as tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide; halogenated compounds such as carbon tetrachloride and brominated titanium; Hydrocarbons; hydrocarbons such as pentaf X-nitroethane; And acrolein, methacrolein, aryl alcohol, 2-ethylhexylthioglycolate, terpinole Α, terbinene, water terbinene, dipentene, α—methylstyrene dimer (2-4—diphenyl 4-methyl-1-pentene is preferably 50% by weight or more), 2,5—dihydrofuran, 3 , 6-dihydro-12-pin, phthalane, 1, 2-butadiene, 1, 4-hexadiene and the like. The amount of the molecular weight modifier is usually 0.005 to 3 parts by weight based on 100 parts by weight of the monomer mixture.

 The method of polymerization is not particularly limited, and bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, or the like can be appropriately selected as needed. Among them, emulsion polymerization is preferred. In the case of production by emulsion polymerization, for example, the polymerization is carried out by a known emulsion polymerization technique, and when a predetermined conversion is reached, the polymerization is stopped by adding hydroxyamine, sodium dihydrocarbamate, and the like. The remaining monomer is removed by heating, steam distillation, etc., and the obtained polymer latex is further coagulated by a usual emulsion polymerization such as an inorganic coagulant, a polymer coagulant or a thermosensitive coagulant. By adding an agent, the copolymer can be coagulated and recovered.

 The method for hydrogenating the conjugated gen unit of the ethylenically unsaturated nitrile conjugated gen-based copolymer rubber is not particularly limited, and is carried out by using a usual hydrogenation method.

 Specifically, the reaction is carried out by blowing hydrogen in the presence of a hydrogenation catalyst in a state where the ethylenically unsaturated nitrile conjugated gen-based copolymer rubber is dissolved in a solvent.

The solvent is capable of dissolving the ethylenically unsaturated nitrile-one conjugated diene copolymer rubber. Specifically, aromatic compounds such as benzene, toluene, xylene, and chlorobenzene; cyclohexanone, acetone, methyl Ketones such as luethyl ketone and getyl ketone; tetrahydrofuran; ethyl acetate: dimethylformamide; Examples of the hydrogenation catalyst include palladium silica and a palladium complex (JP-A-3-252405). Further, Japanese Patent Application Laid-Open Nos. Sho 62-125258, Sho-62-42937, Hei 114-540

No. 2, Japanese Patent Application Laid-Open No. Hei 1-445403, Japanese Patent Application Laid-Open No. Hei 1-445404, Japanese Patent Laid-open No. Hei 11

Rhodium or ruthenium compounds, such as those described in No. 45405, etc., can also be used.

 The hydrogenation reaction temperature is usually 5 to 150 ° C, preferably 10 to 100 ° C. At high temperatures, the hydrogenation catalyst is deactivated or side reactions are more likely to occur. Examples of the side reaction include a reaction in which a nitrile group is hydrogenated.

The ethylenically unsaturated carboxylic acid or its anhydride used in the ene-type addition reaction is not particularly limited, but the ethylenically unsaturated dicarboxylic acid having 4 to 10 carbon atoms or its anhydride, particularly maleic anhydride Acids are preferred. Ethylenically unsaturated carboxylic acids include ethylenically unsaturated monocarboxylic acids such as acrylic acid and methacrylic acid; ethylenically unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid and citraconic acid; maleic anhydride Ethylenic unsaturated dicarboxylic anhydrides such as acid, itaconic anhydride and citraconic anhydride; monomethyl maleate, monoethyl maleate, monopropyl maleate, mono-n-butyl maleate, maleic acid Monoisobutyl, mono-n-pentyl maleate, mono-n-hexyl maleate, mono-2-ethylhexyl maleate, monomethyl fumarate, monoethyl fumarate, monopropyl fumarate, monopropyl fumarate One n-buchi Monoisobutyl fumarate, mono-n-pentyl fumarate, mono-n-hexyl fumarate, mono-1-ethylhexyl fumarate, monomethyl itaconate, monoethyl itaconate, monoethyl itaconate, monopropyl itaconate —Butyl, monoisobutyl itaconate, mono-n-itaconate-pentyl, mono-n-hexa itaconate, mono-l-ethyl hexyl itaconate, monomethyl citrate, monoethyl citrate, monopropyl citrate Mono-n-butyl citraconic acid, monoisobutyl citraconic acid, mono-n-pentyl citraconic acid, mono-n-hexyl citraconic acid, mono-2-ethyl citraconic acid, monomethyl hexyl citraconic acid, monomethyl mesaconic acid, mesacone Monoethyl acid, monopropyl mesaconate, mesacon Mono-n-butyl mono-iso-mesaconate, Mono-n-pentyl mesaconic acid, Mono-n-hexyl mesaconic acid, Mono-1-ethyl mesaconic hexyl, Monomethyl glutaconate, Monoethyl glutaconate, Glutaconate Monopropyl, mono-n-butyl glutaconate, monoisobutyl glutaconate, mono-n-pentyl gunoretaconate, mono-n-hexyl glutaconate, mono-n-hexyl glutaconate, monomethyl arylmalonate, monomethyl arylmalonate, arylmalone Monoethyl acrylate, monopropyl arylmalonate, mono-n-butyl arylmalonate, monoisobutyl arylmalonate, mono-n-pentyl arylmalonate, mono-n-hexyl arylmalonate, mono-1-ethyl arylmalonate, monomethyl terraconate, monomethyl terraconate The terra Monoethyl conate, monopropyl terraconate, mono-n-butyl terraconate, monoisobutyl terraconate, mono-n-pentyl terraconate, mono-n-hexyl terraconate, mono-2-ethyl terraconate-2-ethylhexyl, etc. Unsaturated dicarboxylic acid monoalkyl ester- And the like.

 In the addition-type addition reaction, heating is usually performed without using a radical generator in an inert solvent that dissolves the nitrile group-containing highly saturated copolymer rubber and the ethylenically unsaturated carboxylic acid or its anhydride. Alternatively, this is accomplished by kneading the nitrile group-containing highly saturated copolymer rubber and an ethylenically unsaturated carboxylic acid or an anhydride thereof in a heated closed kneader.

 The amounts of the nitrile group-containing highly saturated copolymer rubber and the ethylenically unsaturated carboxylic acid or its anhydride are not particularly limited, but are usually 100 parts by weight of the nitrile group-containing highly saturated copolymer rubber. On the other hand, the amount is 0.05 to 10 parts by weight, preferably 0.2 to 6 parts by weight for the ethylenically unsaturated carboxylic acid or its anhydride.

 The heat-sealing kneader suitably used in the heat-type addition reaction can be arbitrarily selected from among batch-type heat-sealing kneaders such as a pressure soda, a Banbury mixer, a Brabender, etc. Of these, a pressure kneader is preferred. If an open-type kneader such as a roll-type kneader is used without using a heated closed kneader, the molten ethylenically unsaturated carboxylic acid such as maleic anhydride or its anhydride is scattered. However, it is not preferable because a sufficient addition reaction cannot be performed.

In the case of a continuous kneader such as a single-screw extruder, a co-rotating twin-screw extruder, and a counter-rotating twin-screw extruder, the rubber remaining at the outlet of the extruder is gelled to form a die head. In some cases, the addition reaction cannot be performed efficiently due to clogging of the metal. In addition, a large amount of unreacted ethylenically unsaturated carboxylic acid or its anhydride remains in the rubber. When a carboxylated nitrile group-containing highly saturated copolymer rubber is produced by carrying out an enzymatic addition reaction using a heat-sealing kneader, the following method is used to obtain Carboxylic acid anhydride groups can be present in a high proportion. In general, when the carboxylic anhydride group in the rubber molecule is decomposed and the carboxyl group content is increased, the reaction rate with the compounding agent such as zinc oxide is accelerated, so that scorch is likely to occur at the time of crosslinking, and wear resistance is also increased. This is not preferred because the properties and compression set resistance tend to decrease. The method by which carboxylic anhydride groups can be present in a high proportion in rubber molecules is as follows.

 First, before adding an ethylenically unsaturated carboxylic acid or an anhydride thereof to a nitrile group-containing highly saturated copolymer rubber by an ene-type addition reaction, at a rubber temperature at which substantially no ene-type addition reaction occurs. , Specifically, 60-

170 ° C, preferably 100-150. In C, the ethylenically unsaturated carboxylic acid or its anhydride and the nitrile group-containing highly saturated copolymer rubber are pre-kneaded, and the ethylenically unsaturated carboxylic acid or its anhydride is subjected to the nitrile group-containing highly saturated copolymer. Disperse evenly in it. If the rubber temperature of this pre-kneading is excessively low, the rubber slips in the kneading machine and the mixing of the ethylenically unsaturated carboxylic acid or its anhydride with the nitrile group-containing highly saturated copolymer rubber occurs. Not enough. If the rubber temperature of the pre-kneading is excessively high, a large amount of the ethylenically unsaturated carboxylic acid or its anhydride to be charged into the kneader may be scattered, thereby lowering the rate of the ene-type addition reaction.

Next, the temperature of the mixture of the rubber being kneaded and the ethylenically unsaturated carboxylic acid or its anhydride (hereinafter, sometimes referred to as the rubber temperature) is set at 200 to 2 in order to carry out an ene-type addition reaction. 80 ° C, preferably 220-260 ° C One. The method for keeping the rubber temperature within this range is not particularly limited, but is usually achieved by flowing hot water or steam into the kneader jacket, or by using shear heat.

When hot water or steam is allowed to flow through the jacket of the heat-sealing kneader, the jacket temperature is generally maintained at 70 to 250 ° C, preferably 130 to 200 ° C. When utilizing the heat generated by shearing, the kneading is preferably continued by a kneader at a shear rate of 30 to: L 000 S—preferably 300 to 700 S— ¹ . In particular, it is preferable to use the heat generated by shearing because the rubber temperature can be easily controlled. The kneading time in the heated closed kneader is not particularly limited, but is usually 120 seconds to 120 minutes, preferably 180 seconds to 60 minutes.

 If the rubber temperature during kneading is excessively low, the ene-type addition reaction does not proceed sufficiently. On the other hand, if the content is excessively high, gelation or burning occurs, and as a result, gel is mixed into the product, which is not preferable. On the other hand, if the shear rate is excessively high, it is difficult to control the rubber temperature due to the heat generated by shearing, and the rubber temperature becomes too high, causing gels and burns, which is not preferable as an industrial production method. On the other hand, if the shear rate is excessively low, the rubber temperature becomes too low, so that a sufficient ene-type addition reaction cannot be expected.

 At the time of kneading in such a heat-sealing kneader, an antioxidant may be added to prevent gelation of rubber and increase in Mooney viscosity. The type of anti-aging agent is not particularly limited, but an aging-based, amine-ketone-based, phenol-based, benzimidazole-based, or other rubber-based anti-aging agent can be used.

Examples of amide-based antioxidants include phenyl-1-naphthylamine, Alkylated diphenylamine, octylated diphenylamine, 4,4-bis (α, didimethylbenzyl) diphenylamine, ρ- (ρ-tonolenesulfonylamide) diphenylamine, Ν, Ν-di-2-naphthine Nore _ ρ-phenylenediamine, Ν, Ν-diphenyl ρ-phenylenediamine, Ν-phenylone-isopropyl-ρ-phenylenediamine, Ν-phenylenediamine, (1, 3-dimethylbutyl) 1-ρ-phenylenediamine, Ν-phenyl- (3-methacryloyloxy 2-hydroxypropyl) -1ρ-phenylenediamine and the like.

 Examples of aminketone antioxidants include 2,2,4-trimethyl-1,2-dihydroquinoline, 6-ethokin-1,2-dihydro2,2,4_trimethylquino. And the like.

 Examples of phenolic anti-aging agents include 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,2-methylenebis (4-ethyl-6- tert-butylphenol), 2,2-methylenebis (4-methyl-6-tert-butylphenol), 4,4-butylidenebis (3-methyl-6-tert-butylphenol), 4,4-thiobis (3-methyl-1-phenol) tert-butylphenol), 2.5-di-tert-butylhydroquinone, 2,5-ditert-amylhydroquinone, and the like. Examples of the benzimidazole antioxidants include metal salts of 2-mercaptobenzylazomidazole, 2-mercaptomethylbenzomidazole, and 2-mercaptomethylbenzoimidazole.

The amount of the antioxidant used is preferably 0.01 to 5 parts by weight, more preferably 100 parts by weight of the nitrile group-containing highly saturated copolymer rubber. Is 0.1 to 2 parts by weight.

By adopting such a production method, the acid equivalent is 2 × 10 ³ ephr or more and the peak height of the carboxylic acid anhydride group is measured by infrared absorption spectroscopy. ] + [The peak height of the carboxyl group]) is 0.50 or more, preferably 0.85 or more, and more preferably 0.9 or more. If this value is too small, scorch is likely to occur in the crosslinking reaction.

Here, the value of [peak height of carboxylic acid anhydride group] Z ([peak height of carboxylic acid anhydride group] + [peak height of carboxyl group]) is determined by the measurement using an infrared absorption spectrometer. For the anhydride group, the peak height of the absorption peak observed at around 1785 cm- ¹ and for the carboxyl group, the peak height of the absorption peak observed at around 1170 to 1740 cm- ¹ It is determined based on.

 The polyvinyl chloride resin used in the present invention is not particularly limited. For example, a vinyl chloride homopolymer and a known vinyl chloride copolymer comprising not less than 60% by weight of a vinyl chloride unit and not more than 40% by weight of a unit of another monomer capable of being radically copolymerized with vinyl chloride are exemplified. Can be Such copolymers include, for example, bifunctional polymers such as vinyl chloride-vinyl acetate copolymers, graft copolymers of vinyl chloride with ethylene monoacetate polymers, and small amounts of divinylbenzene, diarylphthalate, etc. And partially cross-linked vinyl chloride resins obtained by copolymerizing monomers.

The polyvinyl chloride resin used in the present invention is not particularly limited in its molecular weight, but usually has an average degree of polymerization of 600 to 2,000. It is.

 The mixing ratio of the carboxylated nitrile group-containing highly saturated copolymer rubber to the polyvinyl chloride resin is generally 95 to 50 parts by weight, preferably 80 to 50 parts by weight, for the carboxylated nitrile group-containing highly saturated copolymer rubber. The amount is 5 to 50 parts by weight, preferably 20 to 40 parts by weight, based on 60 parts by weight of the polyvinyl chloride resin. In particular, a mixture of about 70 parts by weight of a highly saturated copolymer rubber containing a propyloxylated nitrile group and about 30 parts by weight of a polyvinyl chloride resin obtained from a hydride of an acrylonitrile-loop copolymer rubber. Is optimal.

 The method of blending the carboxylated nitrile group-containing highly saturated copolymer rubber and the polyvinyl chloride resin is not particularly limited, but usually, the carboxylated nitrile group-containing highly saturated copolymer rubber and the polyvinyl chloride resin powder are blended. A dry blending method is used in which and are mixed at a high temperature using a Banbury mixer. In addition, the solvent is removed after mixing the copolymer rubber solution and the polyvinyl chloride resin solution, or the dissolution is performed after dissolving the copolymer rubber and the polyvinyl chloride resin in a common solvent. A solution method comprising:

 The rubber composition of the present invention may contain, if necessary, other ordinary compounding agents used in the rubber field, for example, a crosslinking agent such as a sulfur-based crosslinking agent or an organic peroxide-based crosslinking agent, and a reinforcing agent. (Carbon black, silica, talc, etc.), fillers (calcium carbonate, clay, etc.), processing aids, process oils, antioxidants, antiozonants, crosslinking aids, coloring aid rubbers, etc. Can be. The method of compounding is not particularly limited, but usually, it can be performed using an extruder, a roll, or a mixer such as a Banbury mixer.

Sulfur-based cross-linking agents used include powdered sulfur, sulfur white, precipitated sulfur, Sulfur, such as sulfur, surface-treated sulfur, insoluble sulfur; sulfur chloride, sulfur dichloride, morpholine 'disulfide, alkylphenol' disulfide, N, N '-dithio-bis (hexahydro 2H- Sulfur compounds such as azepinone 1 2), phosphorus-containing polysulfides, and high molecular polysulfides; in addition, tetramethylthiuram disulfinolate, dimethyldiethyl selenium rubinate, 2 _ (4 '— (Morpholinoditio) Sulfur-containing crosslinking accelerators such as benzotyfazole.

 Further, in addition to these sulfur-based cross-linking agents, cross-linking accelerators such as zinc oxide, zinc peroxide, active zinc, and stearic acid; guanidine, aldehyde amide, aldehyde-ammonia, Other crosslinking accelerators such as thiazole, sulfenamide, thiourea, and xanthate can be used.

 The amount of the sulfur-based crosslinking accelerator used is not particularly limited, but is usually 0.1 to 10 parts by weight, preferably 0.1 to 100 parts by weight of the highly saturated copolymer rubber containing a carboxylated nitrile group. ~ 5 parts by weight.

 Examples of organic peroxide crosslinking agents include t-butyl hydroperoxide, cumene hydroperoxide, di-t-butylperoxide, t-butylcumylperoxide, 2,5-dimethyl-t-butylperoxyhexane, 2,5_ Dimethyl-t-butylperoxyhexine, 1,3-bis (t-butylperoxyisopropyl) benzene, p-chlorobenzoyl peroxide, t-butylperoxybenzoate, t-butylperoxyisopropylcarbonate And t-butyl benzoate.

The amount of the organic peroxide-based cross-linking agent to be used is usually 0.1% by weight per 100 parts by weight of rubber. It is 0.1 to 30 parts by weight, preferably 0.1 to 10 parts by weight.

 Examples of other cross-linking agents that can be used in combination include polyfunctional compounds such as tri-methylolpropane trimethacrylate, divinylbenzene, ethylene dimethyl acrylate, and triallyl isocyanurate. In addition, metal soaps such as sulfur, triazine Z-dithiophosphate, polycarboxylate nonium salt, and polyamines (hexamethylene diamine, triethylenetetramine, hexamethylene diamine carbamate, Crosslinking agents such as ethylenediamine carbamate and triethylenediamine) and ammonium benzoate can be used in combination, if necessary. These crosslinking agents can be used alone or in combination of two or more.

 In the rubber composition of the present invention, if necessary, an acrylic rubber, a fluoro rubber, a styrene-butadiene copolymer rubber, an ethylene-propylene-one gen ternary, together with a carboxylated nitrile group-containing highly saturated copolymer. Other rubbers such as copolymer rubber (EPDM), natural rubber, and polyisoprene rubber can be used in combination.

Industrial applicability

Composite of oil-resistant rubber composition and fiber

The rubber composition of the present invention has good processability and shows improved adhesion to various fibers such as nylon. Therefore, a product excellent in adhesive strength and mechanical strength can be obtained by cross-linking the composite of the rubber composition and the fiber. This composite is useful for belts, hoses and the like. The fibers used include natural fibers such as cotton, recycled fibers such as rayon, nylon, polyester, vinylon, and aromatic polyamide fibers. Such synthetic fibers, steel fibers, glass fibers, and carbon fibers are included. These fibers may be used alone or in combination of two or more. These fibers are used in the form of staple, filament, or woven fabric such as cord, rope, canvas, or bamboo and embedded in the rubber composition as a tensile member. The type and form of the product can be determined as appropriate according to the type (use) of the intended rubber product.

 Prior to compounding with the rubber composition, each fiber is subjected to a pre-bonding treatment by a method usually applied to each fiber, but does not require any other special treatment. For example, in the case of rayon and nylon, the bonding treatment is usually performed using a mixture of an aqueous solution of a precondensate of resorcinol-formalin (hereinafter abbreviated as R F) and rubber latex (hereinafter abbreviated as R F L).

 On the other hand, fibers such as polyesters and aromatic polyamides have poor adhesiveness to rubber due to their molecular structure, so that sufficient adhesive force may not be obtained by the above-described bonding treatment using RFL. Therefore, prior to treatment with RFL, the fibers are treated with a compound such as isocyanates, ethylene thioureas, epoxies, or a treatment liquid that appropriately combines these compounds, and then heat-treated, followed by treatment with RFL. Done. It is generally effective for glass fibers to be treated with a silane coupling agent such as epoxysilane or aminosilane (for example, aminopropyltriethoxysilane) prior to treatment with RFL.

The rubber latex used in the RFL treatment is not particularly limited. For example, acrylonitrile-butadiene copolymer latex, acrylonitrile-butadiene-methacrylic acid copolymer latex, acryloyl Nitrile copolymer latex such as nitrile-butadiene-acrylic acid copolymer latex, acrylonitrile-butadiene-vinylpyridine acid copolymer latex, and hydrogenated butadiene portion of these copolymers; Epichlorohydrin polymer, copolymer of epichlorohydrin and one or more other epoxides or oxetane, chloroprene rubber, chlorosulfonated polyethylene, chlorinated polyethylene, chlorine-containing monomer copolymerized with chlorine-containing monomer as crosslinking monomer Acryl rubber, brominated butyl rubber, polyvinylidene chloride; chlorinated or brominated gen-based rubber (acrylonitrile-butadiene copolymer rubber, styrene-butadiene copolymer rubber, polybutadiene rubber, etc.), chlorinated or brominated rubber Latex of halogen-containing polymers such as propylene-one-monomer-terpolymer rubber.

 The use of the carboxylated nitrile group-containing highly saturated copolymerized aqueous emulsion as the latex used in the treatment with RFL is preferred because the adhesive force between the rubber composition and the fibers is further enhanced. These rubber latexes can be used alone or in combination of two or more.

 Rubber latex produced by emulsion polymerization can be used as it is. Rubber, which can be obtained as a solid polymer, can be in the form of a latex by, for example, dissolving in a solvent, adding water and an emulsifier, stirring and emulsifying, and then evaporating and removing the solvent. In the present invention, the method for producing latex is not particularly limited.

The RFL solution for treating the fibers is a mixture of the rubber latex and RF. The composition ratio of the liquid mixture is not particularly limited, but is usually It is desirable that the ratio of RF to RF be in the range of 10: 1 to 2: 1 in terms of the solid content weight ratio. In addition, the molar ratio of resorcinol to formalin in the RF solution is not particularly limited, but it is usually desirable that the ratio be 1: 3 to 3: 1. More preferably, the ratio is in the range of 1: 1 to 1.5: 1. As the RF liquid, those commonly used for cross-linking adhesion between the rubber composition and the fibers can be used, and are not particularly limited.

 The method for treating fibers with the RFL treatment solution is not particularly limited in the present invention, but it is common practice to immerse the fibers according to an immersion method, and then to perform a heat treatment. The conditions of the heat treatment are not particularly limited in the present invention, and there are some variations depending on the type of the fiber, but it is sufficient that the temperature and time are sufficient to react and fix the RFL adhered by immersion. This is performed at about 140 to 210 ° C for about 1 to 10 minutes. In general, depending on the type of fiber, it is also possible to preliminarily immerse the fiber in an isocyanate solution, an epoxy solution, or a mixed solution thereof prior to immersion in the heat treatment solution, followed by drying treatment. In this case, the drying temperature is desirably equal to or lower than the subsequent heat treatment temperature.

 When the fiber subjected to the RFL treatment as described above is cross-linked with a carboxylated nitrile group-containing highly saturated copolymer rubber composition, for example, the fiber is treated with a carboxylated nitrile group-containing highly saturated copolymer. After mixing with the rubber composition or laminating with the rubber composition, crosslinking is carried out according to the usual crosslinking conditions of the rubber composition. The crosslinking conditions are not particularly limited, but are usually from 130 to 200 ° C. under a pressure of 0.5 to 10 MPa for 1 to 120 minutes.

Benolet The manufacturing method of the belt is not particularly limited in the present invention. For example, a belt can be manufactured by compounding a rubber composition and a fiber that has been pre-bonded according to a normal belt manufacturing method, forming the composite into a shape suitable for the purpose, and then performing a crosslinking process. .

Hose

 A hose manufactured using the rubber composition of the present invention is not particularly limited in its structure and manufacturing method. The rubber composition of the present invention is particularly suitable as a material for the innermost layer of a multi-layer hose (generally, a two-layer or three-layer hose), but may be used as a material for other layers. Is also good. Each layer of the hose is formed by crosslinking a crosslinkable rubber composition according to the purpose. The crosslinkable rubber composition constituting each layer is obtained by mixing a crosslinker, an auxiliary agent, a filler, an antioxidant, a plasticizer, a processing aid, and the like, with each rubber, if necessary. Further, a braided reinforcing yarn layer may be provided between the crosslinked rubber layers in order to impart strength. The type of yarn of the braided reinforcing yarn layer is not particularly limited, but polyester fibers, nylon fibers, and aramide fibers are usually used because of its excellent heat resistance.

 The two-layer hose is formed, for example, by forming an inner layer with the crosslinkable rubber composition of the present invention, forming a braided reinforcing yarn layer on the outer periphery thereof, applying an adhesive, and then forming the inner layer from the crosslinkable rubber composition. It is manufactured by forming an outer layer comprising the above, and crosslinking the inner layer and the outer layer in a crosslinking step.

For example, a hose having a three-layer structure is formed by forming an inner layer with the crosslinkable rubber composition of the present invention, forming a braided reinforcing yarn layer on the outer periphery of the inner layer, and applying an adhesive to the outer periphery of the braided reinforcing yarn layer. An intermediate layer made of a crosslinkable rubber composition is formed on the outer periphery, an adhesive is applied to the outer periphery of the intermediate layer, and the outer periphery is formed from the crosslinkable rubber composition. It is manufactured by forming an outer layer made of W and cross-linking the inner layer, the intermediate layer and the outer layer in a cross-linking step.

 Gomronore

 The method for producing the rubber roll is not particularly limited in the present invention. The rubber roll can be prepared according to the same method as employed in General 5. For example, a roll-shaped base material such as a metal rotary shaft is put into a roll mold as a core metal, a rubber composition is put there, and a roll is formed around the core metal. And a method of heating to 100 to 250 ° C. for crosslinking.

0 The rubber roll obtained by cross-linking molding is preferably subjected to a surface treatment, if necessary, to reduce the surface frictional resistance or to reduce the adhesive force. Diaphragm

The manufacturing method of the diaphragm is not particularly limited in the present invention. Usually, a rubber roll is topped (top coated) on a base cloth made of nylon fiber, polyester 5-tel fiber, cotton, etc. using a calender roll, and then punched to a predetermined shape and size. The diaphragm can be manufactured by press molding. The molding conditions are a mold temperature of 150 to 190 ° C., a crosslinking time of 3 to 30 minutes, and a molding pressure of 50 to 150 kgf / cm ² . At this time, at least a topping layer on the liquid contact surface side is formed using the rubber composition of the present invention.

 BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described more specifically with reference to examples. Parts and% in Reference Examples, Examples and Comparative Examples are based on weight unless otherwise specified. The characteristics described in each example were measured as follows.

 (1) Evaluation test for physical properties under normal conditions

Using a No. 3 type dumbbell, a test piece was punched out from a 2 mm thick sheet obtained by crosslinking the uncrosslinked rubber composition prepared according to the formulation in Table 1 at 160 ° C for 20 minutes. this test piece, in accordance with JISK 6301, tensile strength ^{(unit: kg ί Zcm 2), 100} % tensile stress (unit: kgf Z cm ²⁾ and elongation (unit:%) was measured. The hardness was measured using a JIS spring type A hardness tester. Further, the compression set was measured after keeping at 100 ° C. for 22 hours in accordance with JISK 6301 (unit:%).

 (2) Oil resistance test

 In accordance with JISK6301, a rubber test piece is immersed in JIS NO.3 oil and JIS fuel oil C (when JIS NO.3 oil is used, immersed at 120 ° C for 70 hours; when JIS fuel oil C is used, it is 60 ° C) for 72 hours, volume change rate (unit:%), tensile strength change rate (%), elongation change rate (%), and hardness change rate (point).

 (3) Sour gasoline resistance test

 Rubber specimens were immersed (72 hours) in JIS fuel oil B containing 1% by weight of lauryl baroxide at 40 ° C, and the volume change rate (%), tensile strength change rate (%), elongation change rate (% ) And hardness change rate (point) were measured.

(4) Ozone resistance (weather resistance) test

In accordance with JISK 6301, a static ozone test was performed on a test piece immersed in fuel C at 40 ° C for 168 hours and air-dried at room temperature for 1 week at an ozone concentration of 40 pp hm and a temperature increase of 20% at a temperature of 40 ° C. Was. 300 After standing for a time, the state of crack generation was observed. As a result of observation, those for which no cracks were observed were indicated by NC.

 (5) Heat aging test

 According to JIS K 6301, the test pieces after being kept at 120 ° C for 72 hours were measured for tensile strength, elongation, and rate of change in hardness (unit: ±%).

 (6) Measurement of bound nitrile unit content

 According to JIS K 6384, the nitrogen content in the copolymer was measured by the Geldar method, and the bound nitrile unit content was determined by calculation (unit: wt%).

 (7) Fiber adhesion test

100 parts by weight of the maleic anhydride-modified rubber was blended with the compounding ingredients shown in Table 1 and kneaded on a roll to prepare a rubber composition sheet having a thickness of about 2.5 mm. Nylon code (6-nylon, structure 1260 DZ2) is composed of an RFL solution containing latex of hydrogenated NBR (iodine value 15, average particle size 0.10, solid content 40% by weight, pH 10.5) After the treatment with the adhesive composition, the composite was laminated with the above rubber composition sheet and crosslinked to prepare a composite of the rubber composition and the fibers. An adhesive composition composed of the RFL solution was prepared according to the formulation in Table 1.

table 1

 (R i F i i ^ ix) ノ

 I no / noresin 丄 1 丄. N ¾R

 Honore Marine v. / Υ 丄 u. O

 Case sorter "1 Π Q

 .

 0 Q C:

 J k,. O m πμ

 = 4 Ϊ- Z a c

 Usha

 (R FL liquid

 Latex 2 50.0 parts

 R F liquid 2 66.0 parts

 Ammonia Water (14%) 22.6 parts

 47.9 parts of water

 Mouth = 4- 1 5 8 6.5 parts Each fiber was immersed in a single code dip machine for testing using the adhesive composition to prepare a treatment code. The obtained treatment code was embedded in the rubber composition at an embedded length of 8 mm, and crosslinked at a press pressure of 5 MPa and a temperature of 150 ° C. for 30 minutes to obtain a composite of fiber and rubber. The obtained composite was subjected to a code pull-out test in accordance with ASTM D2138-72, the initial adhesive strength was measured, and the adhesive state was observed. Those with good adhesion are marked with 〇, and those with poor adhesion are marked with △.

(8) Measurement of acid equivalent The rubber was dissolved in acetone, reprecipitated and purified with n-hexane, and the resulting reprecipitated purified rubber was redissolved in acetone. The acid equivalent was determined by titration with a tanol solution using Timolfen Rain as an indicator.

(9) Infrared absorption analysis

Infrared absorption analyzer (ST Japan Co., Ltd., iris scanning) Type infrared microscopy system). Carboxylic acid anhydride group in the vicinity of ¹ 78 5 cm 1, carboxyl group peak appears in the vicinity of ¹ 710~ 1740 cm 1.

 (10) Measurement of MEK insoluble content

 Finely chop the rubber, place it in an 80 mesh wire mesh basket, immerse the basket in methyl ethyl ketone at room temperature for 48 hours, dry the solids remaining in the basket, and weigh the dried material. The percentage of the weight of the dry matter relative to the weight of the rubber initially placed in the basket was determined.

Reference Example 1 (Preparation of highly saturated copolymer rubber containing carboxylated ditolyl group) Highly saturated polymer rubber containing ditolyl group (acrylonitrile hydrogenated copolymer rubber, iodine value 28, Combined nitrile unit content: 36% by weight, viscosity: 58 parts 100) Using a pressurized kneader (Moriyama Seisakusho, mixing amount: 75 liters, MS type), 100 parts of heated and kneaded kneader It was mastic. At this time, a pressure kneader scratch, the mixing tank, the side plates, while heating the vapor pressure 3 kgf Z cm Ja Kek preparative flowing steam at ² pressure to 130 ° C in the jacket of the pressurizing lid and blade shaft blade rotation speed 30Z25 r pm, was operated under conditions of shear rate 500 S ^1. The filling rate in the pressure kneader was about 89.5% by volume based on the total capacity of the kneader.

 After the rubber temperature rose to 130 ° C, plunger 1.8 parts of maleic anhydride and 0.5 part of 2,6-di-tert-butyl-4-methylphenol (BHT) melted by heating at 65 ° C It was put into a pressurized molder using a pump and kneaded (pre-kneaded) continuously.

Using the shear heat generated by kneading, the rubber temperature is adjusted to 250 ° C, and further kneading is performed at that temperature to carry out the ene-type addition reaction. I let it. The rubber temperature was controlled by flowing water at 35 ° C through the jacket of the pressurized mixer.

 Finally, the mixing tank of the pressure kneader is lowered, and the mixture is kneaded for about 30 seconds, and the rubber composition is dropped and taken out of the pressure kneader to obtain a carboxylated nitrile group-containing highly saturated copolymer rubber. Was. No dirt was found on the blades of the pressurized duster. It should be noted that the operation from charging the nitrile group-containing highly saturated polymer rubber to the pressure kneader, starting the mastication, and finally dropping the rubber composition to take it out of the pressure niger takes 33 minutes. did.

The resulting carboxylated nitrile group-containing highly saturated copolymer rubber, acid equivalent weight 16. ³ x 10- 3 ephr, [peak height of a carboxylic acid anhydride Monomoto] Infrared absorption analysis / ([carboxylic acid anhydride Group peak height] + [Carboxyl group peak height]) value 0.96, MEK insoluble content 0.2% maleic anhydride-added hydrogenated acrylonitrile-butadiene copolymer rubber (modified with maleic acid) ZP-1).

Reference Example 2 (Preparation of carboxylated nitrile group-containing highly saturated copolymer rubber by autoclave)

In the autoclave, the methyl of nitrile group-containing highly saturated polymer rubber (hydrogenated acrylonitrile butadiene copolymer, iodine value 28, bound acrylonitrile unit content 36% by weight, Mooney viscosity 58) An ethyl ketone solution (concentration: 11%) was charged, 30 parts of maleic anhydride was added to 100 parts of the rubber, and then 7 parts of methyl benzoyl peroxide was dissolved under an inert gas atmosphere. The reaction was carried out at 95 ° C for 4 hours while continuously adding the ethyl ketone solution. The reaction product was purified by reprecipitation with a mixed solvent of n-hexanenoethyl ether. The reaction product obtained has an acid equivalent of 18.3 X 10-3ep hr, value of [peak height of carboxylic anhydride group] / ([peak height of carboxylic anhydride group] + [peak height of carboxyl group]) by infrared absorption analysis

0.45, MEK insoluble content 7.1% maleic anhydride-added hydrogenated acrylonitrile-butadiene copolymer rubber (maleic acid-modified ZP-2). Reference Example 3 (Preparation of rubber-polyvinyl chloride resin mixture)

 Heated to approx. 160 ° C 1. Using a Little Banbari (manufactured by Sakai Heavy Industries, Ltd.), set the rotation speed to 100 rpm and the rotation speed ratio of the rotor to 1.12, and carboxylated with vinyl chloride resin. Was mixed with a nitrile group-containing highly saturated copolymer rubber. First, the rubber is charged, the rubber is masticated for 1 minute, and then the polyvinyl chloride resin impregnated with a plasticizer in a ratio of 10: 3 to the powder of the polyvinyl chloride resin is charged and kneaded for 5 minutes. Was done. The remaining plasticizer was used by impregnating carbon black when mixing other compounding agents. Examples 1-3 and Comparative Examples 1-2

The maleic anhydride-added hydrogenated acrylonitrile-butadiene copolymer rubber (maleic acid-modified ZP-1 and maleic acid-modified ZP-2) prepared above was used, and this was combined with a polyvinyl chloride resin. According to the ratios shown in Table 2, a composition containing rubber and polyvinyl chloride resin was prepared by mixing according to the following method. Thereafter, the compounding ingredients shown in Table 2 were blended and kneaded at 40 ° C. using a 6-inch jar to prepare a rubber composition. The rubber composition was cross-linked under pressure at 160 ° C. for 20 minutes by a press molding machine, and the cross-linked properties of the obtained cross-linked product were measured. As a comparison, a commercially available hydrogenated NBR (ZP2020L, bound acrylonitrile unit content 36% by weight, iodine value 28, mu-212 viscosity 60, manufactured by Zeon Corporation) was used. Table 2 shows the results. Table 2

 Example Comparative example

1 2- 3 1 Combination

 Maleic acid modified Z P-1 80 70

 Maleic acid-modified ZP—280

 Zp 2020 then 70 chloride resin 20 30 20 30 zinc oxide 5 5 5 5 stearate 1 1 1 1

 0.5 0.5 0.5 0.5

S R F carbon black 50 50 50 50 Cheuram vulcanization accelerator 1.0 1.0 1.0 1.0 Thiazole vulcanization accelerator 1.5 1.5 1.5 1.5 Ammine antiaging agent 2.0 2.0 2.0 2.0 Plasticizer 20 20 20 20 Tensile test

Tensile strength (kgf / cm ² ) 328 315 311 292 Elongation (%) 470 450 460 470

100% tensile stress 68 59 50 38 Hardness Shore A 67 65 65 66 Air aging test

 (72 hours at 120 ° C)

 Change in tensile strength (%)-3 -4 -7 -11 Change in elongation (%) -8 -13 -15-24 Change in hardness (point) 2 3 4 6 Compression set (%) 62 64 67 78 Oil resistance test

 J I S No. 3 (120 ° C x 70 hours)

 Volume change rate (%) 6 6 7 6 Tensile strength change rate (%) -12 -15 -13 -18 Elongation change rate (%) -34-26 -54-76 Hardness change (point) 7 6 5 7

JIS fuel oil C (60 ° C X 72 hours)

 Volume change 22 20 25 26 Tensile strength change -41 -38 -52 -48 Elongation change -28-24 -35 -29 Hardness change (point) -13-13 -12 -14 Sour gasoline resistance test

 Volume change rate (%) 27 24 30 33 Tensile strength change rate (%) -52-48-62-52 Elongation change rate (%)-29 -25 -38-38 Hardness change (point) -15- 14 -17 -15 Static ozone combined test

 Ozone resistance (300 hours) NC NC NC NC Fiber adhesion test

Peel adhesive strength (kgf / 1 inch) 13.5 13.5 10.0 8.1 Adhesive state ◎ ◎ 〇 X From the results in Table 2, it can be seen that, according to the present invention, the strength properties of the composition containing the maleic anhydride-added hydrogenated acrylonitrile-butadiene copolymer rubber and the polyvinyl chloride resin were higher than those of the prior art. It can be seen that a crosslinked rubber having improved compression set resistance, sour gasoline resistance and adhesion to fibers was obtained. This crosslinked rubber can be suitably used for applications that come into contact with automotive fuel, and is particularly useful as a fuel hose and diaphragm.

 In particular, in the infrared absorption spectroscopy, the value of [peak height of carboxylic anhydride group] / ([peak height of carboxylic anhydride group] + [peak height of carboxyl group]) is large. When a polymer rubber is used, the above properties of the crosslinked rubber tend to be further improved. The invention's effect

 Thus, according to the present invention, a composition containing a maleic anhydride-added hydrogenated acrylonitrile butadiene copolymer rubber and a polyvinyl chloride resin, It is possible to obtain a crosslinked rubber having improved strength characteristics, resistance to compression set, resistance to gasoline and adhesion to fibers.

 The rubber composition of the present invention has excellent processability, and the crosslinked product has excellent mechanical strength and good oil resistance, heat resistance, weather resistance, etc., so that various sealing materials, belts, hoses, etc. It is useful as a diaphragm, diaphragm or other automotive rubber material.

Specifically, various sealing materials such as 0-rings, gaskets, oil seals, freon seals, etc .; belts such as automotive V-belts, poly-ribbed belts, toothed conductive belts, etc .; automotive power steering Nguho Hoses, such as high-pressure oil-resistant hoses for various machines (for example, construction machinery), fuel hoses for automobiles, etc .; rolls; rubber products used in oil and gas wells [Packers, blow-out preventers (BOPs)] , Various types of diaphragms; automotive clutch plates and brakes (these are molded by blending a thermosetting resin such as phenolic resin or epoxy resin with other compounding agents). In addition, it can be widely used for various applications such as various types of vibration-proof rubber, electrical products, automotive parts, industrial supplies, footwear and so on.

Claims

The scope of the claims

1. Polyvinyl chloride resin is blended with a carboxylated nitrile group-containing highly saturated copolymer rubber having an acid equivalent of 2 x 10 " ³ ephr or more, a viscosity of 15 to 200, and an iodine value of 80 or less. An oil-resistant rubber composition comprising:

 2. The carboxylated nitrile group-containing highly saturated copolymer rubber is heated in a heat-sealing kneader at a rubber temperature of 200 to 280 ° C and the nitrile group-containing highly saturated copolymer rubber and the ethylenically unsaturated carboxylic acid. 2. The oil-resistant rubber composition according to claim 1, which is obtained by subjecting an anhydride thereof to an ene-type addition reaction.

 3. The oil-resistant rubber composition according to claim 2, wherein the ethylenically unsaturated carboxylic acid or anhydride thereof has 4 to 10 carbon atoms.

 4. The nitrile group-containing highly saturated copolymer rubber according to any one of claims 1 to 3, wherein the conjugated gen unit of the ethylenically unsaturated nitrile conjugated conjugated copolymer rubber is hydrogenated. Oil resistant rubber composition.

 5. The oil-resistant rubber composition according to any one of claims 1 to 4, wherein the nitrile group-containing highly saturated copolymer rubber has an amount of bound nitrile of 10 to 60% by weight.

 6. The oil-resistant rubber composition according to any one of claims 1 to 5, wherein the nitrile group-containing highly saturated copolymer rubber has an iodine value of 80 or less.

7. The oil-resistant rubber composition according to any one of claims 1 to 6, wherein the highly saturated copolymer rubber containing two tolyl groups has a Mooney viscosity (ML1 _{+ 4} , 100 ° C) of 30 to 300. .

8. Highly saturated copolymer rubber containing nitrile group The value of [peak height of carboxylic acid anhydride group] / ([peak height of carboxylic acid anhydride group] + [peak height of carboxyl group]) is not less than 0.50. Any of the oil-resistant rubber compositions.

 9. The oil-resistant rubber composition according to any one of claims 1 to 8, wherein the polyvinyl chloride resin has an average degree of polymerization of 600 to 2,000.

 10. The mixing ratio of the carboxylated nitrile group-containing highly saturated copolymer rubber to the polyvinyl chloride resin is such that the carboxylated nitrile group-containing highly saturated copolymer rubber has a mixing ratio of 95 to 50 parts by weight of polyvinyl chloride. The oil-resistant rubber composition according to any one of claims 1 to 9, wherein the resin is 5 to 50 parts by weight.

 1 1. A composite of the oil-resistant rubber composition of claim 1 and a fiber.

 12. The composite of claim 11 wherein the fibers have been adhesively treated with a mixture of an aqueous solution of a resorcinol-formalin precondensate and rubber latex.

 13. The composite of claim 11 or 12 for hoses.

 14. The composite of claim 11 or 12 for diaphragms.