JP2006334908A - Laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminate constituted by stacking a rubber layer and a metal layer through an adhesive layer, enhanced in the adhesive strength between the layer and the metal layer and having excellent compression-resistant permanent strain properties in the rubber layer after crosslinking. <P>SOLUTION: In the laminate constituted by stacking the rubber layer and the metal layer with the adhesive layer in between, the rubber layer is constituted of a polar rubber composition containing a polar rubber and at least one kind of a resin selected from a phenol resin and a petroleum resin and the content of the resin in the polar rubber composition is 2-30 pts.wt. with respect to 100 pts.wt. of the polar rubber. The phenol resin is preferably at least one kind of a resin selected from a phenol/acetylene resin and a terpene/phenol resin. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a laminate in which a rubber layer and a metal layer are laminated with an adhesive layer interposed therebetween. More specifically, the adhesive force between the rubber layer and the metal layer is increased when cross-linking is performed. The present invention relates to a laminate having a rubber layer that is high and has excellent compression set resistance.

  Various rubbers are often used as composite materials with metal materials, fibers, inorganic compounds, plastics, and the like. In particular, a composite material obtained by bonding rubber and a metal material is used as various parts such as metal gaskets, oil seals, and vibration-proof rubbers for automobiles and machine tools.

  For example, the Ebonite method, the cyclized rubber method, the phenolic resin method, the halogenated rubber method, the brass plating method, and the electroless plating can be used as the bonding technology for manufacturing such a composite material of rubber and metal material. Laws are known.

  Among these, the phenol resin method is preferably used because the phenol resin used as an adhesive is inexpensive. In such a phenol resin method, polar rubber such as nitrile rubber (NBR) is usually used. Specifically, a metal plate and an uncrosslinked nitrile rubber are laminated through a phenol resin, Subsequently, the composite material of rubber and a metal material is obtained by heating and cross-linking (for example, Patent Document 1).

  However, depending on the type of nitrile rubber (NBR), the adhesiveness with the phenol resin as the adhesive is low, and particularly when the nitrile content is low (for example, 33% or less), the adhesion failure is high. There was a problem.

  In order to improve the adhesive force between the rubber and the adhesive layer, for example, Patent Documents 2 and 3 disclose an adhesive composition in which uncrosslinked NBR is added to a phenol resin as an adhesive. However, in these documents, when the amount of NBR added is increased, the adhesion with NBR is improved, but the viscosity increases, the application work is difficult, and the adhesion strength with metal is lowered. there were.

JP 2000-919 A JP 2003-261850 A JP 2003-147314 A

  The present invention has been made in view of such a situation, and in a laminated body in which a rubber layer and a metal layer are laminated via an adhesive layer, the adhesive force between the rubber layer and the metal layer is high, and An object of the present invention is to provide a laminate having a rubber layer excellent in compression set resistance.

  As a result of intensive studies to achieve the above object, the inventors of the present invention have a laminated body in which a rubber layer and a metal layer are laminated via an adhesive layer. By using a polar rubber composition containing a specific resin, it is possible to increase the adhesive force between the rubber layer and the metal layer, and the rubber layer after crosslinking has a compression set resistance. Based on this finding, the present invention has been completed.

That is, the laminate according to the present invention is
A rubber layer and a metal layer are laminated bodies through an adhesive layer,
The rubber layer is composed of a polar rubber composition containing polar rubber and at least one resin selected from phenol resin and petroleum resin,
The content of the resin in the polar rubber composition is 2 to 30 parts by weight with respect to 100 parts by weight of the polar rubber.

  In the laminate of the present invention, preferably, the phenol resin is at least one selected from a phenol acetylene resin and a terpene-phenol resin.

  In the laminate of the present invention, preferably, the polar rubber is at least one selected from acrylonitrile-butadiene copolymer rubber and acrylic rubber.

  In the laminate of the present invention, preferably, the adhesive layer contains a phenol resin as an adhesive.

  In the laminate of the present invention, preferably, the rubber layer and the metal layer are cross-linked and bonded via the adhesive layer.

  Since the laminate of the present invention uses a polar rubber composition containing a polar rubber and a specific resin for the rubber layer, the adhesive force between the rubber layer and the metal layer can be increased. Furthermore, the rubber layer after crosslinking has excellent compression set resistance. Therefore, the laminate of the present invention can be suitably used, for example, as a metal gasket, oil seal, vibration proof rubber, etc. for automobiles and machine tools.

  In particular, since the polar rubber composition used in the laminate of the present invention has a high affinity with the phenol resin, it is high even when a relatively inexpensive phenol resin is used as the adhesive layer constituting the laminate. Adhesion can be achieved. Therefore, it is possible to effectively prevent occurrence of peeling between the rubber and the adhesive layer, which has been a problem when a phenol resin is used as the adhesive layer.

  In the present invention, the polar rubber composition constituting the rubber layer is a concept including not only an uncrosslinked rubber composition but also a crosslinked product after crosslinking.

The laminate of the present invention has a configuration in which a rubber layer and a metal layer are laminated via an adhesive layer.
Hereinafter, the rubber layer, the adhesive layer, and the metal layer will be described.

Rubber layer In the present invention, the rubber layer is composed of a polar rubber composition containing a polar rubber and a resin.
In the polar rubber composition, the resin is at least one selected from a phenol resin and a petroleum resin, and the content thereof is 2 to 30 parts by weight, preferably 3 parts per 100 parts by weight of the polar rubber. -25 parts by weight, more preferably 5-20 parts by weight. If the content of the resin in the polar rubber composition is too small, the adhesiveness tends to decrease. On the other hand, if the amount is too large, the compression set resistance tends to decrease.

The polar rubber constituting the polar rubber composition is not particularly limited and various rubbers can be used. In addition to carbon (C) and hydrogen (H) in the molecular structure, nitrogen (N), A rubber having a polar group containing atoms such as oxygen (O), sulfur (S), halogen (F, Cl, Br, etc.), phosphorus (P) and the like is preferable. Examples of such polar rubber include nitrile group-containing conjugated diene rubber, acrylic rubber (ACM, ANM), chloroprene rubber (CR), chlorosulfonated polyethylene (CSM), epichlorohydrin rubber (ECO, CHC), and polysulfide rubber (T). , Fluorine rubber (FKM), hydrogenated nitrile rubber and the like. These may be used alone or in combination of two or more.

  The polar rubber used in the present invention preferably has a number average molecular weight in the range of 5,000 to 2,000,000, more preferably in the range of 10,000 to 500,000. If the number average molecular weight is too small, the strength properties of the rubber may be inferior. On the other hand, if it is too large, the moldability tends to be inferior, and in some cases, it tends to be impossible to mold.

Moreover, Mooney viscosity (ML1 _{+ 4} , 100 degreeC) becomes like this. Preferably it is 10-200, More preferably, it is 20-150. If the Mooney viscosity is too low, the strength properties of the rubber may be inferior. On the other hand, when too high, the handleability in an uncrosslinked state will deteriorate, and workability and moldability may be inferior.

  Among these, nitrile group-containing conjugated diene rubbers and acrylic rubbers (ACM, ANM) are particularly preferable because of their high polarity and excellent adhesiveness.

  The nitrile group-containing conjugated diene rubber is a polymer obtained by copolymerizing a conjugated diene, an ethylenically unsaturated nitrile, and other monomers that can be copolymerized with these. Among the nitrile group-containing conjugated diene rubbers, acrylonitrile-butadiene copolymer rubber (NBR, hereinafter referred to as nitrile rubber as appropriate) having the following configuration is more preferable.

As said conjugated diene, a C4-C12 aliphatic conjugated diene compound is mentioned, for example.
Specific examples include 1,3-butadiene, isoprene (2-methyl-1,3-butadiene), 2,3-dimethyl-1,3-butadiene, halogen-substituted butadiene, and the like. Is preferred. These can be used individually by 1 type or in combination of 2 or more types.

As said ethylenically unsaturated nitrile, the C3-C18 ethylenically unsaturated compound which has a nitrile group is mentioned, for example.
Specific examples include acrylonitrile, methacrylonitrile, halogen-substituted acrylonitrile and the like, and acrylonitrile is particularly preferable. These can be used individually by 1 type or in combination of 2 or more types.

  The content of the ethylenically unsaturated nitrile monomer unit in the nitrile rubber is preferably 10 to 80% by weight, more preferably 20 to 60% by weight. When there is too little content of an ethylenically unsaturated nitrile monomer unit, there exists a possibility that polarity may become low. On the other hand, if the amount is too large, the flexibility of the rubber may be reduced.

  Examples of other copolymerizable monomers used as necessary include ethylenically unsaturated carboxylic acid, non-conjugated diene, α-olefin, aromatic vinyl, ethylenically unsaturated monocarboxylic acid ester, fluoroolefin, Examples include ethylenically unsaturated carboxylic acid amides.

Examples of the ethylenically unsaturated carboxylic acid include C3-C18 carboxyl group-containing ethylenically unsaturated compounds.
Specific examples include ethylenically unsaturated monocarboxylic acids, ethylenically unsaturated polyvalent carboxylic acids, and ethylenically unsaturated polyvalent carboxylic acid partial esters.

Examples of the ethylenically unsaturated monocarboxylic acid include acrylic acid, methacrylic acid, ethyl acrylic acid, crotonic acid, and cinnamic acid.
Examples of the ethylenically unsaturated polyvalent carboxylic acid include maleic acid, fumaric acid, itaconic acid, citraconic acid, and chloromaleic acid.
Examples of the ethylenically unsaturated polyvalent carboxylic acid partial ester include monomethyl maleate, monoethyl maleate, monobutyl maleate, monomethyl fumarate, monoethyl fumarate, monobutyl fumarate, mono-2-hydroxyethyl fumarate, monomethyl itaconate, Examples thereof include monoethyl itaconate and monobutyl itaconate.

  Non-conjugated dienes include non-conjugated dienes having 5 to 12 carbon atoms, and specific examples include 1,4-pentadiene, 1,4-hexadiene, vinylnorbornene, and dicyclopentadiene.

  The α-olefin is a chain monoolefin having a double bond between a terminal carbon of a hydrocarbon having 2 to 12 carbon atoms and a carbon adjacent thereto, ethylene, propylene, 1-butene, 4-methyl- Examples include 1-pentene, 1-hexene, 1-octene and the like.

  Examples of the aromatic vinyl include styrene and styrene derivatives having 8 to 18 carbon atoms, and examples of the derivatives include α-methylstyrene, vinyltoluene and the like.

  The ethylenically unsaturated monocarboxylic acid ester is an ester of an ethylenically unsaturated monocarboxylic acid and an aliphatic alcohol having 1 to 12 carbon atoms, and includes methyl (meth) acrylate [methyl methacrylate and / or methyl acrylate. I mean. The same applies to (meth) acrylamide hereinafter. ], Butyl (meth) acrylate, methoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, and the like.

  The fluoroolefin is an unsaturated fluorinated compound having 2 to 12 carbon atoms, and examples thereof include difluoroethylene, tetrafluoroethylene, fluoroethyl vinyl ether, fluoropropyl vinyl ether, o-trifluoromethylstyrene, and pentafluorovinyl vinylate.

  Examples of the ethylenically unsaturated carboxylic acid amide include (meth) acrylamide and N-methylol (meth) acrylamide.

  Nitrile rubber is obtained by performing a polymerization reaction by a known emulsion polymerization method using the above conjugated diene, ethylenically unsaturated nitrile, ethylenically unsaturated carboxylic acid and other monomers used as necessary. be able to.

The nitrile rubber used in the present invention preferably has a number average molecular weight in the range of 10,000 to 1,000,000, and has a Mooney viscosity (ML _{1 + 4} , 100 ° C.) in the range of 20 to 150. preferable.

  Acrylic rubber (ACM, ANM) means (meth) acrylic acid ester monomer [acrylic acid ester monomer and / or methacrylic acid ester monomer in the molecule. The same applies to methyl (meth) acrylate. ] A polymer containing units. The content of the (meth) acrylic acid ester monomer is preferably 80% by weight or more, more preferably 90% by weight or more, and still more preferably 95% by weight or more.

  Examples of (meth) acrylic acid ester monomers include (meth) acrylic acid alkyl ester monomers and (meth) acrylic acid alkoxyalkyl ester monomers.

  The (meth) acrylic acid alkyl ester monomer is preferably an ester of an alkanol having 1 to 8 carbon atoms and (meth) acrylic acid, specifically, methyl (meth) acrylate or ethyl (meth) acrylate. , N-propyl (meth) acrylate, n-butyl (meth) acrylate, isopropyl (meth) acrylate, isobutyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate And cyclohexyl (meth) acrylate. Of these, ethyl (meth) acrylate and n-butyl (meth) acrylate are preferred.

  The (meth) acrylic acid alkoxyalkyl ester monomer is preferably an ester of an alkoxyalkanol having 2 to 8 carbon atoms and (meth) acrylic acid, specifically, methoxymethyl (meth) acrylate, (meth) Ethoxymethyl acrylate, 2-ethoxyethyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-propoxyethyl (meth) acrylate, (meth) acrylic acid Examples include 3-methoxypropyl and 4-methoxybutyl (meth) acrylate. Among these, 2-ethoxyethyl (meth) acrylate and 2-methoxyethyl (meth) acrylate are particularly preferable, 2-ethoxyethyl acrylate and 2-methoxyethyl acrylate.

  Moreover, the acrylic rubber may contain a monomer unit copolymerizable with the (meth) acrylic acid ester monomer. Examples of such copolymerizable monomer units include aromatic vinyl monomers, α, β-ethylenically unsaturated nitrile monomers, and monomers having two or more acryloyloxy groups (polyfunctional acrylic monomers). And olefin monomers other than these, monomers having a crosslinkable group such as a carboxyl group, a halogen atom, an epoxy group or a hydroxyl group, and a diene monomer.

  The acrylic rubber can be obtained by performing a polymerization reaction by a known emulsion polymerization method using the (meth) acrylic acid ester monomer and a monomer copolymerizable therewith.

The acrylic rubber used in the present invention preferably has a number average molecular weight in the range of 10,000 to 100,000, and has a Mooney viscosity (ML _{1 + 4} , 100 ° C.) in the range of 20 to 150. preferable.

In addition to the above polar rubber, the resin polar rubber composition contains at least one selected from a phenol resin and a petroleum resin as a resin.

  The resin used in the present invention preferably has a number average molecular weight (Mn) in the range of 200 to 5,000, more preferably in the range of 300 to 3,000. If the molecular weight is too small, the adhesive force tends to decrease. On the other hand, if it is too large, dispersion tends to be poor when kneaded with rubber.

  In the present invention, the phenol resin is preferably a modified phenol resin, and specifically, at least one selected from a phenol acetylene resin and a terpene-phenol resin is preferable.

  A phenol acetylene resin is a resin obtained by polymerizing a phenol acetylene derivative. Examples of such a phenol acetylene resin include pt-butylphenol acetylene resin obtained by polymerizing pt-butylphenol acetylene.

  The terpene-phenol resin is obtained by copolymerizing a terpene monomer and phenols in the presence of a Friedel-Crafts type catalyst in an organic solvent, and is a hydrogenated terpene phenol resin subjected to hydrogenation treatment. Also good. Examples of the terpene monomer include α-pinene, β-pinene, dipentene, d-, 1-limonene and the like. Examples of phenols include phenol, cresol, bisphenol A, and the like.

The petroleum resin in the present invention is preferably an aliphatic petroleum resin, an aromatic / aliphatic copolymer petroleum resin or an alicyclic petroleum resin, and an aromatic / aliphatic copolymer petroleum resin or alicyclic. More preferred are petroleum-based petroleum resins.
The above-mentioned aliphatic petroleum resin is mainly composed of olefin / diolefin having 4 to 6 carbon atoms such as isoprene, piperylene, 2-methylbutene-1 among cracked oil fractions by-produced from an ethylene plant by petroleum steam cracking. In the present invention, those using piperylene as the main raw material are particularly preferred.
The aromatic / aliphatic copolymer petroleum resin is an olefin / diolefin having 4 to 6 carbon atoms and an aromatic having 8 to 11 carbon atoms such as styrene, vinyltoluene, α-methylstyrene, indene and methylindene. Units can be obtained by copolymerization.

The alicyclic petroleum resin can be obtained by polymerizing a cyclopentadiene monomer as a main component. Specific examples of cyclopentadiene monomers include cyclopentadiene; alkyl-substituted products of cyclopentadiene such as methylcyclopentadiene and ethylcyclopentadiene; cyclopentadiene such as dicyclopentadiene, tricyclopentadiene and methyldicyclopentadiene or alkyl thereof. Multimers of substitutions are exemplified.
The aliphatic petroleum resin, aromatic / aliphatic copolymer petroleum resin, and alicyclic petroleum resin may be hydrogenated hydrogenated products.

  The above aliphatic petroleum resin, aromatic / aliphatic copolymer petroleum resin, and alicyclic petroleum resin are respectively a functional group-containing aliphatic petroleum resin having a reactive functional group and a functional group-containing aromatic / fatty. It is more preferable that they are a group copolymer petroleum resin and a functional group-containing alicyclic petroleum resin. By having a reactive functional group, the adhesive strength at the time of cross-linking adhesion can be improved. Such functional group-containing aliphatic petroleum resins, functional group-containing aromatic / aliphatic copolymer petroleum resins, functional group-containing alicyclic petroleum resins, for example, using acids and acid anhydrides, It can be obtained by modifying an aliphatic petroleum resin, an aromatic / aliphatic copolymer petroleum resin or an alicyclic petroleum resin when it is modified or polymerized. Examples of the reactive functional group include a hydroxyl group, an acid anhydride group, a carboxyl group, a halogen group, an epoxy group, a vinyl group, an isocyanate group, a mercapto group, an amino group, and an ester group. Among these, it is particularly preferable that an acid anhydride group, a carboxyl group, or a hydroxyl group is contained. The content of such a reactive functional group is not particularly limited, but in the case of an acid anhydride group or a carboxyl group, the acid value is preferably 0.1 to 100 mg · KOH / g, more preferably 0.5 to 50 mg. -KOH / g. In the case of a hydroxyl group, the hydroxyl value is preferably 40 to 400 mg · KOH / g, more preferably 60 to 300 mg · KOH / g.

The petroleum resin used in the present invention preferably has a number average molecular weight (Mn) in the range of 200 to 5000, more preferably in the range of 300 to 3000. If the molecular weight is too small, the adhesive force tends to decrease. On the other hand, if it is too large, dispersion tends to be poor when kneaded with rubber.
Moreover, it is preferable that a softening point is the range of 60 to 170 degreeC, More preferably, it is 70 to 150 degreeC. If the softening point is too low, stickiness and handleability tend to be poor when kneaded into rubber, and if the softening point is too high, melting tends to be difficult, resulting in poor dispersion.

The crosslinker polar rubber composition can be made into a crosslinkable rubber composition by further containing a crosslinker.
Such a crosslinking agent is not particularly limited, and various commonly used crosslinking agents suitable for each rubber can be used. In the present invention, when nitrile rubber is used, it is preferable to use a sulfur-based crosslinking agent as the crosslinking agent. Examples of such a sulfur-based crosslinking agent include sulfur or a sulfur donor.

Specifically, examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, and highly dispersible sulfur.
The sulfur donor includes disulfide compounds such as morpholine disulfide and tetramethylthiuram disulfide, polysulfides such as dipentamethylenethiuram tetrasulfide, poly (ethylene tetrasulfide), poly (propylene tetrasulfide), poly ( Polymer polysulfides such as tetraethylene sulfide), N, N′-dithiodi (polymethyleneimine), N, N′-bis (2-benzothiazoylthio) piperazine, and the like.

  The content of the crosslinking agent in the polar rubber composition of the present invention is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 3 parts by weight with respect to 100 parts by weight of the polar rubber. When there is too little content of a crosslinking agent, bridge | crosslinking may become inadequate and there exists a possibility that it may become difficult to maintain the shape of a crosslinked material. On the other hand, if the amount is too large, the cross-linked product becomes too hard, and the elasticity as a cross-linked rubber may be impaired.

Other additives Polar rubber composition may contain other crosslinking accelerators, crosslinking accelerators, reinforcing agents, processing aids, light stabilizers, plasticizers, lubricants, adhesives, lubricants, flame retardants, You may contain additives, such as a glaze, an antistatic agent, a coloring agent, and a filler.

  The crosslinking accelerator may be selected from those suitable for each rubber, and is not particularly limited. However, when a nitrile rubber is used, guanidine, aldehyde-amine, aldehyde-ammonia, thiazole, thiuram , Sulfenamide-based and thiourea-based compounds; alkali metal salts of weak acids, and the like. Among these, thiazole compounds, thiuram compounds, and alkali metal salts of weak acids can be preferably used. These can be used alone or in combination of two or more.

Examples of thiazole compounds include 2-mercaptobenzothiazole, 2-mercaptobenzothiazole zinc salt, 2-mercaptobenzothiazole-cyclohexylamine salt, and dibenzothiazyl disulfide.
Examples of thiuram compounds include tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, and the like.
Examples of the weak metal alkali metal salts include inorganic weak acid salts such as sodium or potassium phosphates and carbonates, or organic weak acid salts such as stearates and laurates.

  The amount of the crosslinking accelerator used is preferably 0.1 to 5 parts by weight, more preferably 0.2 to 3 parts by weight with respect to 100 parts by weight of the polar rubber. If there are too many cross-linking accelerators, the cross-linking speed becomes too fast at the time of cross-linking, the cross-linking accelerator blooms on the surface of the rubber layer (cross-linked product) after cross-linking, or the rubber layer after cross-linking becomes too hard. There is a fear. On the other hand, if there is too little crosslinking accelerator, the tensile strength of the rubber layer after crosslinking may be significantly reduced.

  In the present invention, in addition to the crosslinking accelerator, a crosslinking acceleration assistant may be used. The crosslinking accelerator aid is added to activate the crosslinking accelerator and further accelerate the reaction. Examples of the crosslinking accelerating aid include metal oxides such as zinc oxide and fatty acids such as stearic acid.

  As a method for preparing the polar rubber composition, a method in which polar rubber, resin and additives used as necessary are mixed by an appropriate method such as roll mixing, Banbury mixing, screw mixing, and solution mixing can be adopted. . The order of blending is not particularly limited. However, after sufficiently mixing components that are not easily reacted or decomposed by heat, components that are easily reacted by heat or components that are easily decomposed, such as crosslinking agents and crosslinking accelerators, are not reacted or decomposed. What is necessary is just to mix for a short time at the temperature which is not.

Adhesive layer It is preferable that the adhesive layer which comprises the laminated body of this invention contains the phenol resin as an adhesive agent.
In this invention, since the rubber layer is comprised with the polar rubber composition of this invention which has high affinity with respect to a phenol resin, a phenol resin can be used suitably as an adhesive agent. Examples of such phenol resins include novolak type phenol resins and resol type phenol resins, and these may be used in combination.

  The novolac type phenol resin is obtained by condensation polymerization of phenols and formaldehyde in the presence of an acidic catalyst such as hydrochloric acid or oxalic acid. In the novolac type phenol resin, examples of phenols include phenol, m-cresol, a mixture of m-cresol and p-cresol, bisphenol A, and the like.

  The resol-type phenol resin is obtained by condensation polymerization of phenols and formaldehyde in the presence of a basic catalyst such as an alkali metal hydroxide or a magnesium hydroxide. In the resol type phenol resin, examples of phenols include phenol, a mixture of m-cresol and p-cresol, pt-butylphenol, p-phenylphenol, bisphenol A, and the like.

  The adhesive layer may contain a curing agent for curing these phenol resins. Examples of such a curing agent include hexamethylenetetramine. The content of the curing agent is preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of the phenol resin. When there is too little content of a hardening | curing agent, the heat resistance of an adhesive bond layer may fall. On the other hand, when the amount is too large, the amount of gas generated increases when the rubber layer and the metal layer are crosslinked and bonded, and the adhesive strength may be lowered.

The thickness of an adhesive bond layer is 0.1-200 micrometers normally, Preferably it is 1-100 micrometers. If the thickness of the adhesive layer is too thin, the adhesiveness tends to decrease. On the other hand, if it is too thick, peeling due to breakage such as cracking of the adhesive layer and a solvent in which the adhesive is dissolved tend to remain in the interior, and troubles such as adhesion failure and molding failure tend to increase.
Metal layer Various metal materials can be used for the metal layer constituting the laminate of the present invention, and are not particularly limited. For example, stainless steel, SPCC steel, copper, aluminum and the like can be used. In order to improve the adhesion to the adhesive layer, the metal material constituting such a metal layer is usually used in a state where the adhesive surface is roughened.

Next, the manufacturing method of the laminated body of this invention is demonstrated.
First, a metal material for forming a metal layer is prepared, and a surface to be an adhesive surface is roughened by shot blasting, scotch bride, hairline, dull finish, or the like to form an adhesive surface.

  Next, an adhesive layer is formed on the metal material whose surface has been roughened. The adhesive layer is formed using a phenol resin solution obtained by diluting a phenol resin and a curing agent added as necessary with a solvent such as ethanol. Specifically, this phenol resin solution was applied to the adhesion surface of the metal material by a brush coating method, a dipping method, a spray method, a spray method, a roll coater method, etc., and then dried at room temperature or with warm air. Thereafter, if necessary, an adhesive layer can be formed by baking at a temperature of 100 to 250 ° C. for 10 to 30 minutes.

  Next, a rubber molded body that will form a rubber layer is prepared. The rubber molded body can be obtained by molding the above-described polar rubber composition by a molding method common to rubber processing such as extrusion molding, injection molding, transfer molding, and compression molding.

  For example, when adopting the extrusion molding method, the polar rubber composition prepared by roll mixing or the like is supplied to the feed port of the extruder, and is softened by heating from the barrel in the process of being sent to the head portion with a screw. By passing through a die having a predetermined shape provided in the part, a long sheet-like extruded product having a target cross-sectional shape can be obtained.

  The barrel temperature is preferably 50 to 120 ° C, more preferably 60 to 100 ° C. The head temperature is preferably 60 to 130 ° C, more preferably 60 to 110 ° C. The die temperature is preferably 70 to 130 ° C, more preferably 80 to 100 ° C.

  And a rubber molded object can be obtained by cut | disconnecting the obtained sheet-like extrusion molded product to a predetermined magnitude | size and a shape.

  Next, the rubber molded body and the metal material obtained above are laminated through an adhesive layer to form a laminated body, and 130 ° C. to 220 ° C. in an oven using electricity, hot air, steam, or the like as a heat source. Preferably, the rubber molded body and the metal material are crosslinked and bonded (primary crosslinking) by heating to 140 ° C to 200 ° C. When performing cross-linking adhesion, if necessary, using a press molding machine, a rubber molded body and a metal material on which an adhesive layer has been previously formed are heated in a mold in a pressurized state. A method may be adopted.

  Further, if necessary, the cross-linked and bonded (primary cross-linked) laminate is heated at 130 ° C. to 220 ° C., more preferably 140 ° C. to 200 ° C. for 1 to 48 hours in an oven using electricity, hot air, steam or the like as a heat source. Then, it may be crosslinked (secondary crosslinking).

  In the laminate of the present invention thus obtained, the rubber layer is formed of a predetermined polar rubber composition, so that the adhesive force between the rubber layer and the metal layer can be increased, and the cross-linking is performed. The later rubber layer has high compression set resistance. Therefore, the laminate of the present invention can be suitably used, for example, as a metal gasket, oil seal, vibration proof rubber, etc. for automobiles and machine tools.

  The present invention will be specifically described below with reference to examples and comparative examples. [Part] and [%] in these examples are based on weight unless otherwise specified. However, the present invention is not limited only to these examples. In addition, the obtained sample was evaluated by the following method.

Using a laminate sample (cross-sectional area of the rubber layer and the metal layer is 25 mm × 60 mm) obtained by cross-linking and bonding the metal adhesive rubber layer and the metal layer through the adhesive layer, JIS K 6256 is used. Therefore, the 90 ° peel test was performed, and the 90 ° peel strength and peel failure rate were determined to evaluate the metal adhesion. The higher the 90 degree peel strength and the peel fracture ratio, the more preferable. In this example, the 90 degree peel strength is preferably 8 N / mm or more, and the peel fracture ratio is preferably 80% or more.

Using a cylindrical cross-linked sample having a compression-resistant set diameter of 29 mm and a height of 12.5 mm in accordance with JIS K 6262, this cross-linked sample was compressed by 25% in an environment of 120 ° C. for 70 hours. After placing, the compression was released and the compression set was measured. The compression set rate is better as the numerical value is smaller and the material is more difficult to deform.

Example 1
Production of polar rubber composition Nitrile rubber (Nipol DN2850 manufactured by Nippon Zeon Co., Ltd., Mooney viscosity (ML _{1 + 4} , 100 ° C.) 50, nitrile content 28%): 100 parts by weight, zinc white: 5 parts by weight, stearic acid: 1 part by weight, dioctyl phthalate (plasticizer): 5 parts by weight, carbon black (FEF carbon, manufactured by Tokai Carbon Co., Ltd., Seest SO): 60 parts by weight, aromatic / aliphatic copolymer petroleum resin (Nippon Zeon ( Quinton U190): 10 parts by weight was kneaded using a 1.7 L Banbury mixer. Subsequently, 1.5 parts by weight of sulfur as a crosslinking agent, 1.5 parts by weight of dibenzothiazyl disulfide as a crosslinking accelerator, and 0.4 parts by weight of tetramethylthiuram monosulfide are added to the kneaded material obtained. And the sheet | seat of the uncrosslinked polar rubber composition was manufactured with the 8-inch roll.

  The petroleum resin (Quinton U190 manufactured by Nippon Zeon Co., Ltd.) used in this example is an aromatic / aliphatic copolymer petroleum resin having a number average molecular weight of 1000 and a softening point of 89 ° C.

Production of Laminate Sample Next, a laminate sample obtained by crosslinking and bonding a rubber layer and a metal layer via an adhesive layer using the polar rubber composition obtained above was obtained by the following method. Manufactured.
First, a 3 mm × 25 mm × 60 mm metal plate (JIS G 3141 SPCCSD) was prepared, and using a 320 mesh sandpaper, the surface of this metal plate was roughened, and the surface of the roughened metal plate was Washed using toluene and acetone. Next, a 25% ethanol solution of phenolic resin (adhesive, product number RM-1 manufactured by Qingdao Yashiko Kogyo Co., Ltd.) is applied to the surface of the roughened metal plate, left to air dry for 30 minutes, and then Then, an oven was heated in an oven at a temperature of 150 ° C. for 20 minutes to perform a baking treatment to form an adhesive layer.

  Next, a 2.5 mm × 25 mm × 125 mm uncrosslinked rubber composition sheet was placed on the metal plate on which the adhesive layer was formed to obtain a laminate before crosslinking. And this laminated body before bridge | crosslinking is put into the metal mold | die of 5 mm x 25 mm x 125 mm, It heat-compresses on the conditions of pressure 12MPa, temperature 160 degreeC, and 20 minutes with a press molding machine, The crosslinking reaction of a rubber composition is carried out. The laminate sample for the metal adhesion test (the contact area between the rubber and the metal plate was 25 mm × 60 mm) was obtained.

Manufacture of a cross-linked product sample Separately from the laminate sample, a cross-linked product sample was manufactured by the following method. First, a sheet of an uncrosslinked polar rubber composition was punched into a circle, and a plurality of the obtained circular rubber compositions were superposed to form a cylindrical shape having a diameter of 29 mm and a height of 12.5 mm. Next, this cylindrical polar rubber composition was placed in an oven and heated under the conditions of a temperature of 160 ° C. for 20 minutes to obtain a cylindrical crosslinked product.

  Next, a metal adhesion test was performed using the obtained laminate sample, and a compression set test was performed using a columnar cross-linked sample by the method described above. The results are shown in Table 1.

Examples 2 and 3
Example 1 was used except that pt-butylphenol acetylene resin (Example 2) and terpene-phenol resin (Example 3) were used instead of the aromatic / aliphatic copolymer petroleum resin. Then, a laminate sample and a crosslinked product sample were manufactured, and a metal adhesion test and a compression set test were performed.

  As the pt-butylphenol acetylene resin, a pt-butylphenol acetylene resin having a melting point of about 120 ° C. (collesin manufactured by BASF) is used. As the terpene-phenol resin, a terpene-phenol resin having a number average molecular weight of 550 is used. (YShara Chemical Co., Ltd. YS Polyster T100) was used.

Example 4
A laminate sample and a crosslinked product sample were produced in the same manner as in Example 1 except that the content of the aromatic / aliphatic copolymer petroleum resin was changed to 20 parts by weight. A strain test was performed. The results are shown in Table 1.

Example 5
Instead of nitrile rubber, the same amount of acrylic rubber (Nipol AR72LS, Mooney viscosity (ML _{1 + 4} , 100 ° C.) 33, manufactured by Nippon Zeon Co., Ltd.) 33, sulfur: 1.5 parts by weight as a crosslinking agent and crosslinking accelerator, Instead of 1.5 parts by weight dibenzothiazyl disulfide and 0.4 parts by weight tetramethylthiuram monosulfide: 0.3 parts by weight sulfur, 3 parts by weight sodium stearate, 0.5 parts by weight potassium stearate An uncrosslinked polar rubber composition sheet was produced in the same manner as in Example 1 except that the parts were used. Then, a laminate sample and a crosslinked product sample were produced in the same manner as in Example 1 except that the obtained sheet-like polar rubber composition was used and the crosslinking conditions were changed to a temperature of 170 ° C. and 20 minutes. Adhesion tests and compression set tests were performed. The results are shown in Table 1.

Comparative Example 1
Instead of nitrile rubber, the same amount of styrene butadiene rubber (Nipol 1502, manufactured by Nippon Zeon Co., Ltd., Mooney viscosity (ML _{1 + 4} , 100 ° C.) 52), instead of dioctyl phthalate, the same amount of naphthenic oil, Except having used, the laminated body sample and the crosslinked material sample were manufactured similarly to Example 1, and the metal-adhesion test and the compression set test were done. The results are shown in Table 1.

Comparative Example 2
A laminate in the same manner as in Example 1, except that the same amount of coumarone-indene resin (manufactured by Nippon Steel Chemical Co., Ltd., product coumarone G90) was used instead of the aromatic / aliphatic copolymer petroleum resin. Samples and cross-linked samples were produced and subjected to metal adhesion tests and compression set tests. The results are shown in Table 1.

Comparative Example 3
When producing a laminate sample, a laminate sample and a crosslinked product sample were produced in the same manner as in Example 1 except that an epoxy resin was used instead of a phenol resin, and a metal adhesion test and compression set were produced. A test was conducted. The results are shown in Table 1.

Comparative Example 4
A laminate sample and a crosslinked product sample were produced in the same manner as in Example 1 except that an aromatic / aliphatic copolymer petroleum tree was not used, and a metal adhesion test and a compression set test were performed. The results are shown in Table 1.

Comparative Example 5
A laminate sample and a crosslinked product sample were produced in the same manner as in Example 1 except that the content of the aromatic / aliphatic copolymer petroleum resin was changed to 50 parts by weight. A strain test was performed. The results are shown in Table 1.

  From Table 1, a laminate sample and a cross-linked product sample using a polar rubber composition containing a polar rubber and a predetermined resin of the present invention in a rubber layer and having a resin content of a predetermined amount are bonded to metal. It can confirm that it is excellent in property and compression set resistance (Examples 1-5).

On the other hand, when a styrene butadiene rubber having a low polarity was used instead of the polar rubber, the adhesion was inferior (Comparative Example 1).
In the case where a coumarone-indene resin was used instead of the predetermined resin of the present invention and when the resin was not used, the results were similarly poor in adhesion (Comparative Examples 2 and 4).
Moreover, it became a result inferior to adhesiveness also when using an epoxy resin instead of a phenol resin as an adhesive agent contained in an adhesive bond layer (comparative example 3).
Furthermore, when the content of the resin (aromatic / aliphatic copolymer petroleum resin) is 50 parts by weight, which is outside the scope of the present invention, the adhesiveness can be secured, but the compression set resistance is inferior. As a result (Comparative Example 5).

Claims (5)

A rubber layer and a metal layer are laminated bodies through an adhesive layer,
The rubber layer is composed of a polar rubber composition containing polar rubber and at least one resin selected from phenol resin and petroleum resin,
The laminated body whose content of the said resin in the said polar rubber composition is 2-30 weight part with respect to 100 weight part of said polar rubbers.   The laminate according to claim 1, wherein the phenol resin is at least one selected from a phenol acetylene resin and a terpene-phenol resin.   The laminate according to claim 1 or 2, wherein the polar rubber is at least one selected from acrylonitrile-butadiene copolymer rubber and acrylic rubber.   The said adhesive bond layer is a laminated body in any one of Claims 1-3 containing the phenol resin as an adhesive agent.   The laminate according to any one of claims 1 to 4, wherein the rubber layer and the metal layer are cross-linked and bonded via the adhesive layer.