Resin-rubber composite

Abstract

This resin-rubber composite is obtained by sequentially laminating, on an adhesive surface of a resin molded article with a rubber, (1a) an organic metal compound having at least one chelate ring and an alkoxyl group represented by a general formula or a general formula (wherein M1: titanium, zirconium, tin, M2: aluminum, R: an alkyl group having 1-8 carbon atoms, R': a methyl group, an OR group, n: an integer of 1-3, m: 1 or 2) or (1b) a mixture of the organic metal compound and a metal alkoxide compound, and (2) a silane-based adhesive layer, which is a top coating layer as well as a surface treatment agent layer containing silica having a solid content ratio of 90:10 to 50:50 by weight and not containing a silane coupling agent or an oligomer thereof, and an EPDM layer, which is a rubber layer, or a phenolic resin-based adhesive layer, which is a top coating layer, and a fluororubber layer, a nitrile rubber layer, or a hydrogenated nitrile rubber layer, which are rubber layers.

Description

Resin-rubber composite

[0001] The present invention relates to a resin-rubber composite, and more particularly to a resin-rubber composite having excellent durable adhesion.

[0002] Metals such as brass and stainless steel are used as materials for diaphragms and valves because of their durability, including water resistance and alkali resistance, but resins such as polyphenylene sulfide resin (PPS), polytetrafluoroethylene resin (PTFE), and polyacetal resin (POM) are also used to make parts lighter.

[0003] These substrates are poorly adhesive to rubber, and it is difficult to ensure stable adhesion between them. Therefore, a method is used in which the substrate is subjected to a surface treatment and then coated with an adhesive containing a synthetic resin, a chlorinated rubber resin, a metal oxide, a silane coupling agent, or the like.

[0004] Surface roughening is a common surface treatment, but in the case of PPS resin in particular, surface roughening can cause breakage and deformation.

[0005] Patent No. 4,953,564

[0006] An object of the present invention is to provide a resin-rubber composite having a lightweight resin as a base material, which has improved not only initial adhesion but also durable adhesion properties such as alkali resistance and warm water resistance.

[0007] The object of the present invention is to provide a resin molded article having a surface to be bonded to rubber, the surface comprising a compound represented by the general formula (1a): (wherein M1 is titanium, zirconium or tin, R is an alkyl group having 1 to 8 carbon atoms, R' is a methyl group or an OR group, and n is an integer of 1 to 3) or a compound of the general formula (1b) an organometallic compound having at least one chelate ring and an alkoxyl group represented by the formula (1a) (where M2 is aluminum, R is an alkyl group having 1 to 8 carbon atoms, R' is a methyl group or an OR group, and m is 1 or 2), or (1b) a mixture of said organometallic compound and a metal alkoxide compound, and (2) silica, in a weight ratio of 90:10 to 50:50 as a solid content ratio, the resin-rubber composite being formed by sequentially laminating a silane-based adhesive layer as an undercoat layer and a topcoat layer as a surface treatment agent containing no silane coupling agent or its oligomer, and an EPDM rubber layer, or a phenolic resin-based adhesive layer as a topcoat layer and a fluororubber layer, a nitrile rubber layer, or a hydrogenated nitrile rubber layer as a rubber layer.

[0008] The resin-rubber composite of the present invention is lighter than a metal-rubber composite, and exhibits the effects of not only excellent initial adhesion but also excellent durable adhesion such as alkali resistance and warm water resistance, without the need for roughening the resin surface.

[0009] Resins that can be used include polyphenylene sulfide (PPS) resin, polytetrafluoroethylene (PTFE) resin that has been defluorinated by plasma treatment or metallic sodium treatment, polyacetal (POM) resin, polyimide (PI) resin, polyethylene (PE) resin, polyethylene terephthalate (PET) resin, polypropylene (PP) resin, etc., and preferably PPS resin or PTFE resin that has been defluorinated by plasma treatment or metallic sodium treatment, etc. A primer layer is formed on the bonding surface of these resin molded products with rubber using a surface treatment agent.

[0010] As the surface treatment agent, among the surface treatment agents previously proposed by the applicant in Patent Document 1, the surface treatment agent represented by the general formula (1a) (wherein M1 is titanium, zirconium or tin, R is an alkyl group having 1 to 8 carbon atoms, R' is a methyl group or an OR group, and n is an integer of 1 to 3) or a compound of the general formula (1b) an organometallic compound having at least one chelate ring and an alkoxyl group represented by the formula (1a) (where M2 is aluminum, R is an alkyl group having 1 to 8 carbon atoms, R' is a methyl group or an OR group, and m is 1 or 2), or a mixture of the organometallic compound and a metal alkoxide compound, and (2) silica, in a weight ratio of 90:10 to 50:50 as a solid content, without containing a silane coupling agent or its oligomer.

[0011] general formula R: CH3, C2H5, n-C3H7, i-C3H7, n-C4H9, i-C4H9, i-C8H 17Examples of the organometallic compounds represented by R': CH3 group or OR M1: Ti, Zr, Sn n: an integer of 1 to 3 include diisopropoxytitanium bis(methyl acetoacetate), diisopropoxytitanium bis(ethyl acetoacetate), diisopropoxytitanium bis(propyl acetoacetate), diisopropoxytitanium bis(butyl acetoacetate), diisopropoxytitanium bis(hexyl acetoacetate), di-n-propoxytitanium bis(methyl acetoacetate), di-n-propoxytitanium bis(ethyl acetoacetate), di-n-propoxytitanium bis(methyl acetoacetate), di-n-propoxytitanium bis(ethyl acetoacetate), di-n- Propoxytitanium bis(propyl acetoacetate), di-n-propoxytitanium bis(butyl acetoacetate), di-n-propoxytitanium bis(hexyl acetoacetate), di-n-butoxytitanium bis(methyl acetoacetate), di-n-butoxytitanium bis(ethyl acetoacetate), di-n-butoxytitanium bis(propyl acetoacetate), di-n-butoxytitanium bis(butyl acetoacetate), di-n-butoxytitanium bis(hexyl acetoacetate), 1,Organic titanium compounds such as 3-propanedioxytitanium bis(ethyl acetoacetate), diisopropoxytitanium bis(acetylacetonate), di-n-propoxytitanium bis(acetylacetonate), di-n-butoxytitanium bis(acetylacetonate), titanium tetraacetylacetonate, titanium tetraethyl acetoacetate, titanium tetrapropyl acetoacetate, and titanium tetrabutyl acetoacetate; diisopropoxyzirconium bis(methyl acetoacetate), diisopropoxyzirconium bis(ethyl acetoacetate), diisopropoxyzirconium bis(propyl acetoacetate), diisopropoxyzirconium bis(butyl acetoacetate), and diisopropoxyzirconium bis(methyl acetoacetate). di-n-propoxyzirconium bis(hexylacetoacetate), di-n-propoxyzirconium bis(methylacetoacetate), di-n-propoxyzirconium bis(ethylacetoacetate), di-n-propoxyzirconium bis(propylacetoacetate), di-n-propoxyzirconium bis(butylacetoacetate), di-n-propoxyzirconium bis(hexylacetoacetate), di-n-butoxyzirconium bis(methylacetoacetate), di-n-butoxyzirconium bis(ethylacetoacetate), di-n-butoxyzirconium bis(propylacetoacetate), di-n-butoxyzirconium bis(butylacetoacetate), di-n-butoxyzirconium bis(hexylacetoacetate), 1,Organic zirconium compounds such as 3-propanedioxyzirconium bis(ethyl acetoacetate), diisopropoxyzirconium bis(acetylacetonate), di-n-propoxyzirconium bis(acetylacetonate), di-n-butoxyzirconium bis(acetylacetonate), diisopropoxytin bis(methyl acetoacetate), diisopropoxytin bis(ethyl acetoacetate), diisopropoxytin bis(propyl acetoacetate), diisopropoxytin bis(butyl acetoacetate), diisopropoxytin bis(hexyl acetoacetate), di-n-propoxytin bis(methyl acetoacetate), di-n-propoxytin bis(ethyl acetoacetate), di-n Examples of organic tin compounds include di-n-propoxytin bis(propyl acetoacetate), di-n-propoxytin bis(butyl acetoacetate), di-n-propoxytin bis(hexyl acetoacetate), di-n-butoxytin bis(methyl acetoacetate), di-n-butoxytin bis(ethyl acetoacetate), di-n-butoxytin bis(propyl acetoacetate), di-n-butoxytin bis(butyl acetoacetate), di-n-butoxytin bis(hexyl acetoacetate), 1,3-propanedioxytin bis(ethyl acetoacetate), diisopropoxytin bis(acetylacetonate), di-n-propoxytin bis(acetylacetonate), and di-n-butoxytin bis(acetylacetonate).

[0012] Also, the general formula R: CH3, C2H5, n-C3H7, i-C3H7, n-C4H9, i-C4H9, i-C8H 17Examples of the organometallic compounds represented by R': CH3 group or OR M2: Al m: 1 or 2 include diisopropoxyaluminum mono(methyl acetoacetate), diisopropoxyaluminum mono(ethyl acetoacetate), diisopropoxyaluminum mono(propyl acetoacetate), diisopropoxyaluminum mono(butyl acetoacetate), diisopropoxyaluminum mono(hexyl acetoacetate), di-n-propoxyaluminum mono(methyl acetoacetate), di-n-propoxyaluminum mono(ethyl acetoacetate), di-n-propoxyaluminum mono(propyl acetoacetate), dibutoxyaluminum mono(butyl acetoacetate), di-n-propoxyaluminum mono(hexyl acetoacetate), dibutoxyaluminum mono(methyl acetoacetate), dibutoxyaluminum mono(ethyl acetoacetate), dibutoxyaluminum mono(propyl acetoacetate), dibutoxyaluminum mono(butyl acetoacetate), dibutoxyaluminum mono(hexyl acetoacetate), diisopropoxyaluminum mono(acetyl acetonate), etc.

[0013] Furthermore, these organometallic compounds having at least one chelate ring and an alkoxyl group can also be used as a mixture with a metal alkoxide compound, and examples of the metal alkoxide compound include tetraisopropoxytitanium, tetra-n-propoxytitanium, tetra-n-butoxytitanium, tetra(2-ethylhexyl)titanate, tetraisopropoxyzirconium, tetra-n-propoxyzirconium, tetra-n-butoxyzirconium, tetraisopropoxytin, tetra-n-propoxytin, tetra-n-butoxytin, triisopropoxyaluminum, mono-sec-butoxydipropoxyaluminum, tri-sec-butoxyaluminum, and tri(2-ethylhexyl)aluminum.

[0014] Among the organometallic compounds, organotitanium compounds are preferably used, and the organometallic compounds may be used alone or as a mixture of two or more kinds.

[0015] The silica (silicon oxide) used is a dispersion of dry or wet silica with an SiO2 content of 85% or more in an organic solvent or water, preferably a colloidal silica prepared by dispersing high-purity anhydrous silica particles in an organic solvent or water. Colloidal silica has an average particle size of about 1-50 nm, preferably about 10-30 nm, and is dispersed in an organic solvent such as methanol, methyl ethyl ketone, or methyl isobutyl ketone. Examples of commercially available colloidal silica include Methanol Silica Sol (a Nissan Chemical Industries product; dispersed in methanol at a solids concentration of 30% by weight), Snowtex MEK-ST (a Nissan Chemical Industries product; dispersed in methyl ethyl ketone at a solids concentration of 30% by weight), and Snowtex MIBK-ST (a Nissan Chemical Industries product; dispersed in methyl isobutyl ketone at a solids concentration of 30% by weight).

[0016] The organometallic compound and silica are used in a weight ratio of 90:10 to 50:50 in terms of solids, preferably 70:30 to 50:50. The solid content of the organometallic compound is the amount of residue remaining after evaporating to dryness at 135°C for one hour. This amount is an indicator of the amount of organometallic compound remaining on the substrate when actually used for surface treatment. The organic solvent solution is prepared so that the total solids concentration is approximately 0.01 to 5 wt%. Using a higher silica content results in a decrease in heat resistance and adhesion failure after high-temperature heating. Using a lower silica content results in poor liquid resistance to water, LLC, and other solvents. Examples of organic solvents include alcohols such as methanol, ethanol, and isopropanol; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; and polyhydric alcohols or derivatives such as ethylene glycol monomethyl ether, monoethyl ether, monobutyl ether, and monoethyl ether acetate.

[0017] In addition, when a surface treatment agent consisting of a silane coupling agent or its oligomer, an organometallic compound and silica is used, for example, by adding an equal weight of the silane coupling agent oligomer to the organometallic compound, the water resistance and heat resistance are significantly reduced, making it difficult to achieve the object of the present invention, and the storage stability of the surface treatment agent formulation is also extremely poor. For this reason, even if such prior art existed before the present application, it should be distinguished in the present invention from them.

[0018] As a surface treatment agent containing the above components as essential components, a commercially available product, for example, J50F manufactured by NOK, can be used as is. Such a surface treatment agent can be applied to the adhesive surface of the resin molded product with rubber by immersion, spraying, brushing, roll coating, or other methods, at a concentration of about 10 to 1000 mg / m 2 , preferably about 50 to 500 mg / m 2 After drying at room temperature or with hot air, it is baked at approximately 80 to 250°C for approximately 0.5 to 30 minutes to form a primer layer.

[0019] After the undercoat layer is applied to the resin molded product and dried, a topcoat layer is formed using an adhesive appropriate for the type of rubber to be bonded. Examples of rubber include fluororubber, EPDM rubber, nitrile rubber (NBR), and hydrogenated nitrile rubber (HNBR). For adhesives, a silane-based adhesive is used for EPDM, and a phenolic resin-based adhesive is used for NBR and HNBR.

[0020] Silane-based adhesives are made from hydrolyzed condensates of organoalkoxysilanes. Organoalkoxysilanes are generally represented by the formula R"Si(OR)3, where R is a lower alkyl group such as methyl or ethyl, and R" is a group such as methyl, ethyl, 3-aminopropyl, N-(2-aminoethyl)-3-aminopropyl, N-phenyl-3-aminopropyl, vinyl, 3-methacryloxypropyl, 3-glycidoxypropyl, or 3-mercaptopropyl.

[0021] The hydrolysis and condensation reaction of organoalkoxysilanes is carried out by heating to approximately 40 to 80°C in the presence of water for hydrolysis and an acid catalyst such as formic acid. Furthermore, as such hydrolysis and condensation products, copolymerized oligomers of amino-group-containing alkoxysilanes and vinyl-group-containing alkoxysilanes are preferably used. Examples of the amino-group-containing alkoxysilane, which is one component of the copolymerized oligomer, include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and N-β-(aminoethyl)-γ-aminopropyltriethoxysilane. Examples of the vinyl-group-containing alkoxysilane, which is the other component, include vinyltrimethoxysilane and vinyltriethoxysilane.

[0022] In the oligomerization reaction, about 25 to 400 parts by weight, preferably about 50 to 150 parts by weight, of vinyl-containing alkoxysilane and about 20 to 150 parts by weight of water for hydrolysis are used per 100 parts by weight of amino-containing alkoxysilane. If a higher proportion of vinyl-containing alkoxysilane is used, compatibility with the topcoat or rubber will be poor, resulting in reduced adhesion, while if a lower proportion is used, water resistance will be reduced.

[0023] The oligomerization reaction involves placing these materials in a reactor equipped with a distillation apparatus and agitator and stirring at approximately 60°C for approximately 1 hour. Then, approximately 1-2 moles of acid, such as formic acid or acetic acid, are added per mole of amino-containing alkoxysilane within 1 hour. The temperature is maintained at approximately 65°C. The reaction continues for approximately 1-5 hours with stirring, while the alcohol produced by hydrolysis is distilled under reduced pressure. The distillation is terminated when only water remains in the distillate. The desired copolymer oligomer is then obtained by diluting the distillate to a silane concentration of approximately 30-80% by weight. This copolymer oligomer is soluble in alcohol-based organic solvents such as methanol and ethanol. Commercially available copolymer oligomers can also be used as is.

[0024] It is preferable to further add an organometallic compound to these silane adhesives. Examples of the organometallic compound include organoaluminum compounds such as triisopropoxyaluminum, mono-sec-butoxydipropoxyaluminum, tri-sec-butoxyaluminum, ethyl acetoacetate aluminum diisopropylate, aluminum tris(ethyl acetoacetate), aluminum monoacetylacetonate bis(ethyl acetoacetate), and aluminum tris(acetylacetate); tetraisopropoxytitanium, tetra-n-butoxytitanium, isopropoxytitanium bis(ethyl acetoacetate), and 1 Examples include organic titanium compounds such as 3-propanedioxytitanium bis(ethylacetoacetate), diisopropoxytitanium bis(acetylacetonate), and titanium tetraacetylacetonate; organic zirconium compounds such as tetra-n-propylzirconium, tetra-n-butoxyzirconium, di-n-butoxyzirconium bis(acetylacetonate), and di-n-butoxyzirconium bis(ethylacetoacetate); and organic tin compounds such as dibutyltin dilaurate, dibutyltin dioctate, and dibutyltin dilaurate.

[0025] These organometallic compounds are used in a proportion of about 100 parts by weight or less, preferably about 20 to 80 parts by weight, per 100 parts by weight of the hydrolysis-condensation product. Addition of the organometallic compound in such a proportion increases the liquid resistance to heated water, ethylene glycol or its aqueous solution, alcohol, etc. On the other hand, if used in a proportion greater than this, compatibility with the rubber deteriorates, resulting in reduced adhesion.

[0026] Silane-based adhesives, which contain the above components as essential ingredients, are generally prepared and used as solutions with a concentration of approximately 0.2 to 3% by weight in a mixed solvent of water and an alcohol-based organic solvent such as methanol, ethanol, or isopropanol, or a ketone-based organic solvent such as acetone or methyl ethyl ketone. The organic solvent and water are mixed in proportions such that the former is 100 to approximately 80% by weight, and the latter is 0 to approximately 20% by weight. When water is used in combination, the hydrolysis condensation product further increases in molecular weight, allowing for the formation of a tough coating.

[0027] In addition, commercially available silane adhesives such as Chemlok AP-133 manufactured by Lord Japan Inc., Metalok S-2 manufactured by Toyo Kagaku Kenkyusho, and Megam 3290-1 manufactured by Rohm and Haas can also be used after diluting them with an alcohol-based solvent or an alcohol-water mixed solvent.

[0028] As the phenolic resin adhesive, commercially available products such as Metalock N31 from Toyo Kagaku Kenkyusho, Sixon 715 from DDP Specialty Products Japan, TS1677-13 from Lord Japan Inc., and Chemlock 205 from the same company can generally be used as is, with the preferred blend being a 9:1 to 1:9 mixture of novolac phenolic resin and resol phenolic resin. The adhesive is applied by dipping or spraying, dried at room temperature or with warm air, and then baked at about 80 to 250°C for about 1 to 30 minutes to form a topcoat layer.

[0029] An intermediate coat layer is preferably provided between the primer coat and top coat. This intermediate coat layer can be a vulcanizing adhesive containing phenolic resin and epoxy resin, typically a commercially available product such as Metalock PH-37 (Toyo Kagaku Kenkyusho) or Chemlok XPJ-60 (Lord Japan Inc.). These intermediate coat adhesives are typically prepared as organic solvent solutions containing alcoholic organic solvents such as methanol, ethanol, or isopropanol, or ketone organic solvents such as acetone, methyl ethyl ketone, or methyl isobutyl ketone, either alone or in combination, at a concentration of approximately 0.1 to 20% by weight. The solution is applied using a method similar to that used for surface treatment agents, dried at room temperature or with warm air, and then baked at approximately 80 to 250°C for approximately 1 to 30 minutes to form the intermediate coat layer. The application of this intermediate coat layer further improves LLC resistance at temperatures between approximately 85 and 120°C.

[0030] Onto the topcoat layer thus formed, an unvulcanized fluororubber compound, EPDM compound, nitrile rubber compound, or hydrogenated nitrile rubber compound is applied as an organic solvent solution, dried at room temperature to about 100°C for about 1 to 15 minutes, and the organic solvent (e.g., alcohols such as methanol and ethanol, ketones such as methyl ethyl ketone and methyl isobutyl ketone, aromatic hydrocarbons such as toluene and xylene, or mixed solvents thereof) is evaporated. Then, pressure crosslinking is carried out at about 150 to 250°C for about 30 seconds to 10 minutes, followed by secondary crosslinking at about 100 to 250°C for about 1 to 24 hours, forming a rubber layer and obtaining a rubber-resin laminate. The composition of these rubber compounds is not particularly limited, but examples include the following: (Compounding Example I) EPDM (Mitsui Chemicals EPT1070H) 100 parts by weight FEF carbon black 30 parts by weight Titanium oxide 70 parts by weight Stearic acid 1.3 parts by weight Anti-aging agent (Ouchi Shinko Chemicals Nocrac White) 2 parts by weight Polyterpene resin 5 parts by weight (Goodyear Wingtack 95) Dicumyl peroxide (Nomura Chemicals Percumyl D) 5 parts by weight Triallyl cyanurate (Degussa Chemicals Activator OC) 3 parts by weight (Compounding Example II) Fluorine rubber (DuPont Chemicals Viton GLT305) 100 parts by weight SRF carbon black 25 parts by weight Sodium stearate 1 part by weight Triallyl isocyanurate (Nomura Chemicals TAIC) 3 parts by weight Organic peroxide (Nomura Chemicals Perhexa 25B-40) 3 parts by weight Same (Compound Example III) NBR (Japan Synthetic Rubber Products N237: Medium-High Nitrile) 100 parts by weight HAF carbon black 10 Same SRF carbon black 40 SamePowdered cellulose 10 parts by weight Zinc oxide 10 parts by weight Stearic acid 1 part by weight Microcrystalline wax 2 parts by weight Antioxidant (Ouchi Shinko Chemical Products ODA-NS) 4 parts by weight Plasticizer (Bayer AG Bucanol OT) 5 parts by weight Organic peroxide (NOF Products Perhexa 25B) 6 parts by weight N,Nm-phenylenedimaleimide 1 part by weight (Compound example IV) Hydrogenated NBR (ZEON Corporation Zetpol 2020) 100 parts by weight SRF carbon black 60 parts by weight Graphite 10 parts by weight Powdered cellulose 10 parts by weight Stearic acid 1 part by weight Antioxidant (Ouchi Shinko Chemical Products Nocrac CD) 1 part by weight Antioxidant (Ouchi Shinko Chemical Products Nocrac MMB) 0.4 parts by weight Microcrystalline wax 1 Same Plasticizer (Asahi Denka RS-735) 15 Same Organic peroxide (Nippon Yushi Peroximon F40) 7.5 Same N,Nm-phenylenedimaleimide 2 Same

[0031] The present invention will now be described in detail with reference to examples, although the present invention, including its effects, is not limited to these examples.

[0032] Example 1 A surface treatment agent (NOK product J50F; solid content ratio of organometallic compound to silica 60:40) was applied by dip coating to the adhesive surface of polyphenylene sulfide resin (DIC product A504X90) to be bonded to rubber. After drying at room temperature, the resin was baked at 200°C for 10 minutes to form a surface treatment layer.

[0033] A 0.02 to 2.0 wt % methanol diluted solution of a silane adhesive (Chemlock AP-133, a product of Lord Japan Inc.) was applied onto the surface treatment layer by dip coating, dried at room temperature, and then baked at 150°C for 5 minutes to form a topcoat layer.

[0034] An uncrosslinked EPDM rubber compound (Compound Example I) was bonded onto the topcoat layer, and pressure crosslinking was carried out at 180°C for 6 minutes, followed by secondary crosslinking at 150°C for 1 hour to obtain a rubber laminate.

[0035] Example 2 In Example 1, a methyl ethyl ketone diluted solution of phenolic resin and epoxy resin adhesive (Metalock PH-37, a product of Toyo Kagaku Kenkyusho) was applied onto the surface treatment layer by dip coating, dried at room temperature, and then baked at 200°C for 10 minutes to form an intermediate layer between the surface treatment layer and the topcoat layer.

[0036] Example 3 In Example 1, polytetrafluoroethylene resin (Nichias product 9000-G25) that had been defluorinated by metallic sodium treatment was used instead of polyphenylene sulfide resin.

[0037] Example 4 In Example 2, polytetrafluoroethylene resin (9000-G25) was used in place of the polyphenylene sulfide resin.

[0038] Example 5 In Example 2, the fluororubber compound of the above-mentioned Compounding Example II was used in place of the EPDM rubber compound.

[0039] Example 6 In Example 2, a phenolic resin adhesive (Thixon 715, a product of Dow Chemical) was used in place of the silane adhesive, and the NBR rubber compound of Formulation Example III was used in place of the EPDM rubber compound.

[0040] Example 7 In Example 2, a phenolic resin adhesive (Thixon 715) was used in place of the silane adhesive, and the hydrogenated NBR rubber compound of Compounding Example IV was used in place of the EPDM rubber compound.

[0041] Comparative Example 1 In Example 1, the surface treatment layer was not formed.

[0042] Comparative Example 2 In Example 1, no topcoat layer was provided.

[0043] Comparative Example 3 In Example 1, a silane-based adhesive (AP-133) was used to form the surface treatment layer.

[0044] Comparative Example 4 In Example 2, the surface treatment layer was not formed.

[0045] Comparative Example 5 In Example 1, an alkylsilane coupling agent (Dow Toray product OFS-6366) was used in place of the silane adhesive.

[0046] Comparative Example 6 In Example 2, an alkylsilane coupling agent (OFS-6366) was used instead of the silane adhesive.

[0047] Adhesion was evaluated using the resin-rubber composites obtained in each of the above examples and comparative examples. Adhesion: According to JIS K6256-2 "90° peel strength from a rigid plate" corresponding to ISO 813 and a physical destructive test using pliers, the R retention (%) was measured initially and after immersion in 85°C hot water or LLC (a mixed solvent of 50% ethylene glycol and 50% water) at 85°C, 105°C, or 120°C for 72, 240, and 720 hours, and was evaluated as follows: 95-100% = ◎, 90-94% = ○, 50-89% = △, and 0-49% = ×.

[0048] The results obtained are shown in the following table: In Comparative Example 2, the adhesion to the rubber was insufficient at the initial stage, causing peeling, and further testing could not be carried out.

[0049] The resin-rubber composite of the present invention exhibits excellent resistance to (hot) water and chemicals, and is therefore effectively used as a material for diaphragms and valves.

Claims

1. On the adhesive surface of the resin molded product with rubber, (1a) general formula (wherein M1 is titanium, zirconium or tin, R is an alkyl group having 1 to 8 carbon atoms, R' is a methyl group or an OR group, and n is an integer of 1 to 3) or a compound of the general formula (1b) an organometallic compound having at least one chelate ring and an alkoxyl group represented by the formula (1a) (where M2 is aluminum, R is an alkyl group having 1 to 8 carbon atoms, R' is a methyl group or an OR group, and m is 1 or 2), or (1b) a mixture of said organometallic compound and a metal alkoxide compound, and (2) silica, in a weight ratio of 90:10 to 50:50 as a solid content ratio, the resin-rubber composite being obtained by sequentially laminating a silane-based adhesive layer as an undercoat layer and a topcoat layer as an EPDM rubber layer, or a phenolic resin-based adhesive layer as a topcoat layer and a fluororubber layer, a nitrile rubber layer, or a hydrogenated nitrile rubber layer as a rubber layer.

2. The resin-rubber composite of claim 1, further comprising a vulcanized adhesive layer containing a phenolic resin and an epoxy resin between the surface treatment layer and the top coat layer.

3. The resin-rubber composite of claim 1 or 2, wherein the resin is polyphenylene sulfide resin, polytetrafluoroethylene resin or polyacetal resin.

4. The resin-rubber composite according to claim 1 or 2, wherein the silane-based adhesive is an adhesive comprising a copolymer oligomer of an amino-group-containing alkoxysilane and a vinyl-group-containing alkoxysilane.

5. The resin-rubber composite according to claim 1 or 2, wherein the phenolic resin adhesive is an adhesive in which novolak phenolic resin and resol phenolic resin are blended in a ratio of 9:1 to 1:

9.

6. The resin-rubber composite according to claim 1 or 2, which is a valve or a diaphragm.

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