JP2018094847A - Rubber laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber laminate which has good adhesive strength and is obtained by crosslinking bonding of a carboxyl group-containing acrylic rubber composition layer and an organic peroxide-crosslinkable fluororubber composition layer.SOLUTION: There is provided a rubber laminate which is obtained by crosslinking bonding of a carboxyl group-containing acrylic rubber composition layer comprising (A) a carboxyl group-containing acrylic rubber, (B) 1,3-diallyl-5-glycidylisocyanurate, (C) 1,4-diazabicyclo[2.2.2]octane, (D) a primary amine represented by the general formula, RNH(where, R is an aliphatic hydrocarbon group having 1 to 30 carbon atoms) and (E) a crosslinking agent for a carboxyl group-containing acrylic rubber and an organic peroxide-crosslinkable fluororubber composition layer comprising (a) an organic peroxide-crosslinkable fluororubber, (b) 1,3-diallyl-5-glycidylisocyanurate, (c) 1,4-diazabicyclo[2.2.2]octane, (d) a triallyl isocyanurate and (e) an organic peroxide crosslinking agent.SELECTED DRAWING: None

Description

  The present invention relates to a rubber laminate. More specifically, the present invention relates to a rubber laminate obtained by crosslinking and bonding a carboxyl group-containing acrylic rubber composition layer and an organic peroxide crosslinkable fluororubber composition layer.

  Increasing the thermal efficiency of internal combustion engines as part of environmental measures, and the use of vehicles equipped with turbocharger systems to comply with exhaust gas regulations has been spreading.

  Since the air led from the turbocharger to the intercooler and the engine is high temperature and pressure, the hose material for transporting the air is required to have high heat resistance. In addition, exhaust gas from the engine contains NOx and SOx and reacts with moisture in the exhaust gas to produce nitric acid and sulfuric acid, so the hose material is required to have acid resistance in addition to heat resistance .

  In order to solve such problems, there has been proposed a rubber laminate in which the inner layer is an organic peroxide crosslinkable fluororubber layer and the outer layer is an acrylic rubber layer (Patent Documents 1 and 2). Specifically, Patent Document 1 describes a rubber laminate in which a fluororubber layer to which an amine or imine is added and an acrylic rubber layer are crosslinked and bonded using an organic peroxide.

In Patent Document 3, a laminate of a non-fluorine rubber layer (A) and a peroxide-crosslinkable fluororubber layer (B) laminated thereon, the non-fluorine rubber layer (A) is
(a1) Unvulcanized acrylic rubber
(a2) selected from 1,8-diazabicyclo [5.4.0] undecene-7 or a salt thereof, 1,5-diazabicyclo [4.3.0] nonene-5 or a salt thereof and imidazole
(a4) A layer formed from a rubber composition for vulcanization selected from iron dithiocarbamate and an aldehyde amine vulcanizing agent is described.

  Regarding unvulcanized acrylic rubber, it is said that it can take various cross-linking sites and is not limited to carboxyl groups, and it is stated that higher fatty acid amines such as stearylamine and oleylamine can be added as processing aids. Yes.

  The formed laminate is evaluated by an adhesive strength test (T-type peel test), and evaluation of adhesiveness by material destruction (evaluation: ○) or interface peeling (evaluation: x) at the interface (25 ° C) or The measurement of the adhesive strength is performed at 25 ° C. or 140 ° C., but the value (25 ° C.) is only 2.0 to 3.2 N / mm.

  In Patent Documents 4 to 5, a fluororubber comprising an acrylic rubber layer (A) comprising an acrylic rubber composition containing a carboxyl group-containing acrylic rubber and a polyvalent amine compound and a fluororubber composition containing an organic peroxide crosslinking agent. A rubber laminate in which layer (B) is cross-linked and bonded, wherein at least one of the acrylic rubber composition and the fluororubber composition contains an isocyanurate compound and a diazabicycloalkene compound to improve cross-linking adhesion Is used.

Evaluation of the obtained rubber laminate was performed by a peel test with a peel angle of 180 ° and a peel speed of 50 mm / min, and the situation at the adhesive interface was rubber failure, but the peel strength _TF was 2.1 N / mm. It is. When sodium carbonate is further added to the acrylic rubber composition, the _TF value is 3.1 N / mm.

JP 2004-17485 A JP 2008-195040 A JP 2014-111359 A JP2015-9384A Japanese Patent Laying-Open No. 2015-9385 JP 2010-235955 A

  An object of the present invention is to provide a rubber laminate obtained by crosslinking and bonding a carboxyl group-containing acrylic rubber composition layer and an organic peroxide crosslinkable fluororubber composition layer having good adhesive strength.

The object of the present invention is (A) carboxyl group-containing acrylic rubber, (B) 1,3-diallyl-5-glycidyl isocyanurate, (C) 1,4-diazabicyclo [2.2.2] octane, (D) general A carboxyl group-containing acrylic comprising a primary amine represented by the formula RNH ₂ (where R is an aliphatic hydrocarbon group having 1 to 30 carbon atoms) and (E) a crosslinking agent for carboxyl group-containing acrylic rubber. Rubber composition layer and
(a) an organic peroxide crosslinkable fluororubber, (b) 1,3-diallyl-5-glycidyl isocyanurate, (c) 1,4-diazabicyclo [2.2.2] octane, (d) triallyl isocyanurate and (e) It is achieved by a rubber laminate obtained by crosslinking and bonding an organic peroxide crosslinkable fluororubber composition layer containing an organic peroxide crosslinking agent.

  1,3-diallyl having a glycidyl group that reacts with a carboxyl group and an allyl group that can react with a free group in the carboxyl group-containing acrylic rubber composition layer and the organic peroxide crosslinkable fluororubber composition layer, respectively. -5-glycidyl isocyanurate and 1,4-diazabicyclo [2.2.2] octane are blended, and the acrylic rubber composition layer is blended with a primary amine to form a carboxyl group-containing acrylic rubber composition layer and an organic peroxide. A strong cross-linked adhesive layer is formed at the interface with the physical crosslinkable fluororubber composition layer.

  Each component of the carboxyl group-containing acrylic rubber composition will be described below.

  The carboxyl group-containing acrylic rubber of component (A) is at least selected from alkyl (meth) acrylates having an alkyl group having 1 to 8 carbon atoms and alkoxyalkyl (meth) acrylates having an alkoxyalkyl group having 2 to 8 carbon atoms. A copolymer obtained by copolymerizing one kind of (meth) acrylate and a carboxyl group-containing unsaturated compound is used.

  Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, n-hexyl (meth) acrylate, 2 -Ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, etc. are used. In general, the longer the chain length of the alkyl group, the more advantageous in terms of cold resistance, but disadvantageous in oil resistance, and the shorter the chain length, the opposite tendency is seen, from the balance of oil resistance and cold resistance. Is preferably ethyl acrylate or n-butyl acrylate.

  Examples of the alkoxyalkyl (meth) acrylate include methoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, n-butoxyethyl (meth) acrylate, ethoxypropyl (meth) acrylate, methoxy Ethoxyethyl (meth) acrylate, ethoxyethoxyethyl (meth) acrylate, and the like are used, and 2-methoxyethyl acrylate and 2-ethoxyethyl acrylate are preferably used.

  Alkyl (meth) acrylate and alkoxyalkyl (meth) acrylate may be used alone, but preferably the former is used in a proportion of 40 to 100% by weight, and the latter is used in a proportion of 60 to 0% by weight. In the case of copolymerization, the balance between oil resistance and cold resistance becomes good. However, if the copolymerization is carried out at a proportion higher than this, normal properties and heat resistance tend to be lowered.

  Examples of carboxyl group-containing unsaturated compounds include monoalkyl esters of maleic acid or fumaric acid methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, etc., itaconic acid or methyl citraconic acid, ethyl, propyl, isopropyl, n- Examples thereof include monoalkyl esters such as butyl and isobutyl, preferably maleic acid mono n-butyl ester, fumaric acid monoethyl ester, and fumaric acid mono n-butyl ester. In addition to these, unsaturated monocarboxylic acids such as acrylic acid and methacrylic acid are also used.

  These carboxyl group-containing unsaturated compounds are used in such a copolymerization ratio as to occupy about 0.5 to 10% by weight, preferably about 1 to 7% by weight in the carboxyl group-containing acrylic rubber. Insufficient vulcanization results in deterioration of compression set value. On the other hand, if the copolymerization ratio is increased, scorching becomes easier. The copolymerization reaction is carried out so that the polymerization conversion rate is 90% or more. Therefore, the weight ratio of each charged monomer is almost the copolymer composition weight ratio of the produced copolymer.

  In the carboxyl group-containing acrylic rubber, there are other copolymerizable ethylenically unsaturated monomers such as styrene, α-methylstyrene, vinyl toluene, vinyl naphthalene, (meth) acrylonitrile, acrylic acid amide, vinyl acetate, Cyclohexyl acrylate, benzyl acrylate, 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, ethylene, propylene, piperylene, butadiene, isoprene, pentadiene, and the like can be copolymerized in a proportion of about 10% by weight or less.

  Further, if necessary, for the purpose of improving kneading processability and extrusion processability, a polyfunctional (meth) acrylate or oligomer having a glycol residue in the side chain, such as ethylene glycol, propylene glycol, 1,4- Di (meth) acrylates of alkylene glycols such as butanediol, 1,6-hexanediol, 1,9-nonanediol, di (meth) acrylates such as neopentyl glycol, tetraethylene glycol, tripropylene glycol, polypropylene glycol, bisphenol A. Ethylene oxide adduct diacrylate, dimethylol tricyclodecane diacrylate, glycerin methacrylate acrylate, 3-acryloyloxyglycerin monomethacrylate and the like can be further copolymerized and used.

  Component (B), 1,3-diallyl-5-glycidyl isocyanurate, is used in an amount of 0.05 to 5 parts by weight, preferably 0.1 to 3 parts by weight, based on 100 parts by weight of the carboxyl group-containing acrylic rubber. If it is used less than this, sufficient adhesive strength with fluororubber cannot be obtained. Moreover, even if it mix | blends more than this, the adhesive strength with fluororubber will not improve and it will become uneconomical. As 1,3-diallyl-5-glycidyl isocyanurate, a commercially available product such as Shikoku Kasei Kogyo Co., Ltd. DA-MGIC can be used as it is.

  Component (C), 1,4-diazabicyclo [2.2.2] octane, is used in an amount of 0.01 to 5 parts by weight, preferably 0.1 to 3 parts by weight, based on 100 parts by weight of the carboxyl group-containing acrylic rubber. If it is less than this, sufficient adhesive strength with fluororubber cannot be obtained. Moreover, if more than this is used, adhesive strength with fluororubber will not improve and it will become uneconomical. For 1,4-diazabicyclo [2.2.2] octane, a commercially available product such as a Wako Pure Chemical Industries product can be used as it is.

Component (D) The primary amine represented by the general formula RNH ₂ is used in an amount of 0.1 to 5 parts by weight, preferably 0.1 to 3 parts by weight, based on 100 parts by weight of the carboxyl group-containing acrylic rubber. However, R is an aliphatic hydrocarbon group having 1 to 30 carbon atoms, and preferably 8 to 30 carbon atoms from the viewpoint of vapor pressure. If it is less than this, the effect of improving adhesiveness cannot be obtained. On the other hand, even if it is used more than this, the improvement of the adhesive strength cannot be expected and it becomes uneconomical.

Primary amines represented by RNH ₂ are methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, 1-methylpropylamine, tertiary butylamine, n-pentylamine, 1-methylbutylamine. , 3-methylbutylamine, cyclopentylamine, n-hexylamine, cyclohexylamine, n-heptylamine, n-octylamine, 1-ethylhexylamine, n-nonylamine, n-decylamine, n-undecylamine, n-dodecylamine N-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, oleylamine, stearylamine and the like. These may be used alone or in combination of two or more.

  As the crosslinking agent for the carboxyl group-containing acrylic rubber of component (E), a polyvalent amine compound or a derivative thereof, specifically, an aliphatic polyvalent amine compound, a carbonate of an aliphatic polyvalent amine compound, an amino group is an organic group It is possible to use an aliphatic polyvalent amine or an aromatic polyvalent amine protected with.

  For example, examples of the aliphatic polyvalent amine compound include hexamethylenediamine and N, N′-dicinnamylidene-1,6-hexanediamine. Examples of the carbonate of the aliphatic polyvalent amine compound include hexamethylenediamine carbamate. Examples of the aliphatic polyvalent amine in which the amino group is protected with an organic group include compounds disclosed in Patent Document 6.

  As aromatic polyvalent amine compounds, 4,4′-methylenedianiline, m-phenylenediamine, p-phenylenediamine, 4,4′-diaminodiphenyl ether, 4,4′-bis (4-aminophenoxy) biphenyl, m-xylylenediamine, p-xylylenediamine, 1,3,5-benzenetriamine, 4,4 '-(m-phenylenediisopropylidene) dianiline, 4,4'-(p-phenylenediisopropylidene) dianiline 2,2′-bis [4- (4-aminophenoxy) phenyl] propane, 4,4′-diaminobenzanilide, 4,4′-bis (4-aminophenoxy) biphenyl, and the like.

  Of these polyvalent amine compounds, hexamethylenediamine carbamate, 4,4'-diaminodiphenyl ether and 2,2'-bis [4- (4-aminophenoxy) phenyl] propane are preferred.

  The crosslinking agent is used in an amount of 0.1 to 5 parts by weight with respect to 100 parts by weight of acrylic rubber. If the blending amount of the crosslinking agent is less than this, the crosslinking becomes insufficient, leading to a decrease in mechanical properties and a crosslinking rate of the crosslinked product. When there are more compounding quantities of a crosslinking agent than this, bridge | crosslinking advances excessively and the elasticity of a crosslinked material may fall.

  A carboxyl group-containing acrylic rubber composition may contain a crosslinking accelerator together with a crosslinking agent. Examples of the crosslinking accelerator include guanidine compounds, aldehyde amine compounds, thiourea compounds, thiazole compounds, sulfenamide compounds, thiuram compounds, quaternary ammonium salts and the like. Of these, guanidine compounds are preferred. Examples of the guanidine compound include 1,3-diphenylguanidine, 1,3-diortolylguanidine and the like, and 1,3-di-o-tolylguanidine is particularly preferable.

  For the carboxyl group-containing acrylic rubber composition, for example, a filler, a processing aid, a plasticizer, a softening agent, an anti-aging agent, a colorant, a stabilizer, an adhesion aid, a release agent, and conductivity imparting are provided as necessary. Agent, thermal conductivity imparting agent, surface non-adhesive agent, tackifier, flexibility imparting agent, heat resistance improver, flame retardant, ultraviolet absorber, oil resistance improver, foaming agent, scorch preventive agent, lubricant, etc. Additives can be blended.

  Examples of the filler include silica such as basic silica and acidic silica, metal oxides such as zinc oxide, calcium oxide, titanium oxide, and aluminum oxide; metal hydroxides such as magnesium hydroxide, aluminum hydroxide, and calcium hydroxide; Metal carbonates such as magnesium carbonate, aluminum carbonate, calcium carbonate and barium carbonate; silicates such as magnesium silicate, calcium silicate, sodium silicate and aluminum silicate; sulfates such as aluminum sulfate, calcium sulfate and barium sulfate Metal sulfides such as synthetic hydrotalcite, molybdenum disulfide, iron sulfide, copper sulfide; diatomaceous earth, asbestos, lithopone (zinc sulfide / barium sulfide), graphite, carbon black (MT carbon black, SRF carbon black, FEF) Carbon black), carbon fluoride, fluoride fluoride Siumu, coke, quartz powder, zinc oxide, talc, mica powder, wollastonite, carbon fiber, aramid fiber, various whiskers, glass fiber, organic reinforcing agents, organic fillers and the like.

  As processing aids, higher fatty acids such as stearic acid, oleic acid, palmitic acid and lauric acid; higher fatty acid salts such as sodium stearate and zinc stearate; higher fatty acid amides such as stearic acid amide and oleic acid amide; oleic acid Higher fatty acid esters such as ethyl, petroleum waxes such as carnauba wax and ceresin wax; polyglycols such as ethylene glycol, glycerin and diethylene glycol; aliphatic hydrocarbons such as petrolatum and paraffin; silicone oils, silicone polymers, low molecular weight polyethylene Phthalic acid esters, phosphoric acid esters, rosin, (halogenated) dialkylamine, (halogenated) dialkylsulfone, surfactants and the like.

  Examples of plasticizers include epoxy resins, derivatives of phthalic acid and sebacic acid, softeners such as lubricating oils, process oils, coal tar, castor oil, calcium stearate, and antiaging agents such as phenylenediamines and phosphates. Fate, quinoline, cresol, phenol, dithiocarbamate metal salt and the like.

The carboxyl group-containing acrylic rubber composition comprises a carboxyl group-containing acrylic rubber, 1,3-diallyl-5-glycidyl isocyanurate, 1,4-diazabicyclo [2.2.2] octane, a primary amine represented by RNH ₂ , It can be prepared using a Banbury mixer, a pressure kneader, an open roll or the like by blending an agent and other compounding agents used as necessary.

  Next, each component of the organic peroxide crosslinkable fluororubber composition will be described below.

  The organic peroxide crosslinkable fluororubber as component (a) is a copolymer of fluorine-containing unsaturated monomers having iodine atoms and / or bromine atoms in the main chain and / or side chain of the polymer chain. Further, non-fluorine unsaturated monomers such as propylene and ethylene may be copolymerized at a ratio of 30% by weight or less.

  Fluorine-containing unsaturated monomers include tetrafluoroethylene, vinylidene fluoride, hexafluoropropylene, trifluoroethylene, chlorotrifluoroethylene, 1,1,3,3,3-pentafluoropropylene, perfluoro (methyl vinyl ether) ), Perfluoro (ethyl vinyl ether), perfluoro (propyl vinyl ether) and the like.

  Organic peroxide crosslinkable fluororubbers include vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene-perfluoro (methyl vinyl ether) terpolymer, tetrafluoroethylene-ethylene-perfluoro (Methyl vinyl ether) terpolymer, tetrafluoroethylene-propylene copolymer, copolymer of tetrafluoroethylene or vinylidene fluoride and propylene, and the like.

  In addition to the above fluorine-containing unsaturated monomer or non-fluorine unsaturated monomer, a fluorine-containing unsaturated monomer for modifying the properties of fluororubber may be copolymerized in a proportion of 3% by weight or less. Good. Fluorine-containing unsaturated monomers for modifying the properties of fluororubber include perfluoro (3,6-dioxa-1,7-octadiene), 3,3,4,4,5,5,6, 6-octafluoro-1,7-octadiene, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10-dodecafluoro-1,9- Examples thereof include fluorine-containing diene compounds such as decadiene.

  The iodine atom and / or bromine atom that is the crosslinking site of the organic peroxide-crosslinkable fluororubber is in the presence of fluorine-containing dihalogen compounds such as 1,4-diiodooctafluorobutane and 1-bromo-2-iodotetrafluoroethane. If the polymerization reaction is carried out, it can be introduced into the end of the polymer main chain. By copolymerizing monoiodo-containing fluorine-containing ethylene such as 1-iodotrifluoroethylene and 1,1-difluoro-2-iodoethylene, iodine atoms can be introduced into the polymer main chain. Perfluoro (2-bromoethyl vinyl ether), 4-iodo-3,3,4,4-tetrafluoro-1-butene, etc. can be copolymerized to introduce iodine or bromine atoms into the polymer side chain. it can.

  Component (b), 1,3-diallyl-5-glycidyl isocyanurate, is used in an amount of 0.05 to 5 parts by weight, preferably 0.1 to 3 parts by weight, per 100 parts by weight of the organic peroxide crosslinkable fluororubber. If it is less than this, sufficient adhesive strength with acrylic rubber cannot be obtained. Moreover, even if it mix | blends more than this, the adhesive strength with an acrylic rubber will not improve and it will become uneconomical.

  As the component 1,4-diazabicyclo [2.2.2] octane, the same component as the component (C) is used.

  1,4-diazabicyclo [2.2.2] octane is used in an amount of 0.01 to 5 parts by weight, preferably 0.1 to 3 parts by weight, based on 100 parts by weight of the organic peroxide crosslinkable fluororubber. If it is less than this, sufficient adhesive strength with acrylic rubber cannot be obtained. If it is used more than this, the mechanical strength, elongation at break and heat resistance of the crosslinked fluororubber will be reduced.

  The component (d) triallyl isocyanurate is used as a crosslinking aid for organic peroxide-crosslinkable fluororubber. The amount is 0.1 to 10 parts by weight, preferably 1 to 5 parts by weight, based on 100 parts by weight of the organic peroxide crosslinkable fluororubber. If the amount is less than this, crosslinking may be insufficient, and it may be difficult to maintain the shape of the crosslinked product, or mechanical properties may be deteriorated. On the other hand, even if it is used more than this, improvement of various properties such as mechanical properties and heat resistance cannot be expected, which is uneconomical.

  The organic peroxide compound used to crosslink the organic peroxide crosslinkable fluororubber as component (e) includes dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di- Dialkyl peroxy such as (tertiary butyl peroxy) -3-hexyne, 2,5-dimethyl-2,5-di (tertiary butyl peroxy) hexane, 1,3-bis (tertiary butyl peroxyisopropyl) benzene Examples include diacyl peroxides such as oxide, benzoyl peroxide and isobutyryl peroxide, and peroxyesters such as 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane and tertiary butyl peroxyisopropyl carbonate. It is done. Among these, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane is preferable. These may be used alone or in combination of two or more.

  The organic peroxide compound is used in an amount of 0.1 to 5 parts by weight, preferably 0.3 to 3 parts by weight, based on 100 parts by weight of the organic peroxide crosslinkable fluororubber. If it is less than this, the cross-linking of the fluororubber will be insufficient and the mechanical properties of the cross-linked product may be lowered. Moreover, when it uses more than this, excessive bridge | crosslinking will advance and physical properties fall, such as elongation of a crosslinked material, may be caused.

  In addition to the above essential components, the organic peroxide crosslinkable fluororubber composition can be blended with a compounding agent that is usually used in the rubber processing field. Examples of such a compounding agent include inorganic fillers such as carbon black and silica, acid acceptors, crosslinking accelerators, light stabilizers, plasticizers, processing aids, lubricants, adhesives, lubricants, flame retardants, Examples include antifungal agents, antistatic agents, colorants, silane coupling agents, and crosslinking retarders. The compounding amount of these compounding agents is not particularly limited as long as it does not impair the object and effect of the present invention, and an amount corresponding to the compounding purpose can be appropriately compounded.

  The organic peroxide crosslinkable fluororubber composition is prepared by adding 1,3-diallyl-5-glycidyl isocyanurate, 1,4-diazabicyclo [2.2.2] octane, triallyl isocyanate to the organic peroxide crosslinkable fluororubber. A nurate, an organic peroxide, and other compounding agents used as necessary can be blended and prepared using a Banbury mixer, a pressure kneader, an open roll, or the like.

  The method for producing the rubber laminate of the present invention is not particularly limited. For example, for a carboxyl group-containing acrylic rubber composition and an organic peroxide crosslinkable fluororubber composition, after individually forming uncrosslinked sheets of a desired shape with a press, roll or extruder, the respective uncrosslinked sheets are The rubber laminate of the present invention can be produced by applying pressure and heat crosslinking using superposition, heating press or vulcanizing can.

  In addition, the carboxyl group-containing acrylic rubber composition and the organic peroxide crosslinkable fluororubber composition are coextruded with an extruder to form an uncrosslinked rubber tube, and then subjected to pressure and heat crosslinking with a vulcanizing can to form a rubber laminate. The body can be manufactured.

  The hot pressing is usually performed at a temperature of about 140 to 200 ° C. and a pressure of about 0.2 to 15 MPa for about 5 to 60 minutes. In the case of using a vulcanizing can, it is usually carried out at a temperature of about 130 to 160 ° C. under a pressure of 0.18 MPa for about 30 to 120 minutes.

  Further, by further post-curing (secondary crosslinking) the obtained rubber laminate, it is possible to improve the adhesive properties, mechanical properties, compression set and the like of the rubber laminate.

  The rubber laminate of the present invention is not limited to a form in which an acrylic rubber layer and a fluororubber layer are laminated one by one, and these may be laminated alternately.

  The rubber laminate of the present invention thus obtained is an acrylic rubber layer crosslinked with a carboxyl group-containing acrylic rubber and a fluororubber layer crosslinked with an organic peroxide-crosslinkable fluororubber, so that it has excellent heat resistance and oil resistance. And acid resistance. In addition, since the boundary surface is firmly cross-linked, the rubber laminate of the present invention is an oil tube, a fuel hose, an air duct hose, a turbocharger hose, a PCV hose, an intercooler hose, etc. It can be particularly preferably used as a molding material.

  Next, the present invention will be described with reference to examples.

Example 1
<Carboxyl group-containing acrylic rubber composition>
Basic formulation A:
Acrylic rubber A (Unimatec product Noxtite PA-521, 100 parts by weight
(Tg: -15 ℃)
FEF carbon black (Tokai carbon product seast GSO) 55 〃
Stearic acid (Wako Pure Chemical Industries) 1 〃
Stearylamine (Kao Chemical Product Farmin 80) 0.5 〃
4,4'-bis (α, α-dimethylbenzyl) diphenylamine 2
(Ouchi Emerging Chemical Industry Product Nocrack CD)
Hexamethylenediamine carbamate 0.6 〃
(Unimatec product Cheminox AC6)
1,3-di-o-tolylguanidine 2 〃
(Ouchi Emerging Chemical Industry Product Noxeller DT)
1,4-diazabicyclo [2.2.2] octane (Wako Pure Chemical Industries) 1

Formula A-1:
In basic formulation A, 1,4-diazabicyclo [2.2.2] octane was not used.

Formula A-2:
Basic formulation A was used as is.

Formula A-3:
An additional 1 part by weight of 1,3-diallyl-5-glycidyl isocyanurate (Shikoku Kasei Kogyo DA-MGIC) was added to the basic formulation A.

Formula A-4:
In the basic formulation A-3, stearylamine was not used.

Formula A-5:
An additional 1 part by weight of 1-allyl-3,5-diglycidyl isocyanurate (Shikoku Kasei Kogyo MA-DGIC) was added to the basic formulation A.

Formula A-6:
An additional 1 part by weight of triglycidyl isocyanurate (product of Aldrich) was used in addition to the basic formulation A.

After kneading for each of the above blends (compositions), the acrylic rubber composition was subjected to press crosslinking at 180 ° C. for 8 minutes and secondary crosslinking at 175 ° C. for 4 hours, and the fluorine rubber composition was subjected to 180 ° C. Then, press crosslinking for 10 minutes and secondary crosslinking for 6 hours at 200 ° C. were carried out, and the crosslinked physical properties of the crosslinked products were measured in accordance with JIS K6251 and JIS K6253. The measurement results are shown in Table 1 below.
Table 1
Hardness 100% Mo Breaking strength Breaking elongation
Blending (DuroA) (MPa) (MPa ) (%)
A-1 63 3.9 14.3 320
A-2 64 3.7 14.4 310
A-3 61 4.3 14.9 310
A-4 63 4.4 15.3 280
A-5 66 5.5 15.8 250
A-6 63 4.7 15.2 250

Basic formulation B:
In basic formulation A, instead of acrylic rubber A, the same amount (100 parts by weight) of acrylic rubber B (Unimatec product Noxtite PA-522, Tg: -30 ° C) is used. Formulations B-1 to B-6 respectively corresponding to 6 were prepared.

For each formulation, the measurement of kneading, primary crosslinking, secondary crosslinking, and crosslinked physical properties was performed in the same manner. The obtained measurement results are shown in the following Table 2.
Table 2
Hardness 100% Mo Breaking strength Breaking elongation
Blending (DuroA) (MPa) (MPa ) (%)
B-1 59 4.0 11.9 230
B-2 61 4.7 11.8 220
B-3 62 4.9 12.2 210
B-4 63 5.8 12.2 190
B-5 65 8.0 11.8 150
B-6 67 6.5 11.9 160

<Organic peroxide crosslinkable fluororubber composition>
Basic formulation F:
Fluoro rubber (iodine-containing vinylidene fluoride-hexafluoro 100 parts by weight
Propylene (weight ratio 60:40) copolymer,
Mooney viscosity ML _{1 + 10} (121 ° C) 30)
MT carbon black (Cancarb product Thermax MT) 15 〃
Magnesium oxide (Kyowa Chemical Industry Kyowa Mug # 150) 5 〃
2,5-dimethyl-2,5-di (tert-butylperoxy) hexane 3.5 〃
(Japanese oil product Perhexa 25B-40, active ingredient 40%)
Triallyl isocyanurate 5 〃
(Nippon Kasei product Taiku M60, active ingredient 60%)
1,4-diazabicyclo [2.2.2] octane (Wako Pure Chemical Industries, Ltd.) 0.3 〃

Formula F-1:
In basic formulation F, 1,4-diazabicyclo [2.2.2] octane was not used.

Formula F-2:
Basic formulation F was used as is.

Formula F-3:
An additional 1 part by weight of 1,3-diallyl-5-glycidyl isocyanurate (DA-MGIC) was used in addition to the basic formulation F.

Formula F-4:
An additional 1 part by weight of 1-allyl-3,5-diglycidyl isocyanurate (MA-DGIC) was added to the basic formulation F.

Formula A-5:
An additional 1 part by weight of triglycidyl isocyanurate (Aldrich) was used in addition to the basic formulation F.

For each formulation, measurement of kneading, primary crosslinking (180 ° C., 10 minutes), secondary crosslinking (200 ° C., 6 hours) and crosslinking physical properties were performed in the same manner. The obtained measurement results are shown in the following Table 3.
Table 3
Hardness 100% Mo Breaking strength Breaking elongation
Blending (DuroA) (MPa) (MPa ) (%)
F-1 66 3.1 22.5 340
F-2 68 3.6 13.1 210
F-3 68 3.8 14.8 210
F-4 66 3.6 11.4 190
F-5 68 3.1 23.7 320

<Creation of uncrosslinked rubber sheet>
The carboxyl group-containing acrylic rubber composition of Formulations A-1 to A-6 and B-1 to B-6 or the organic peroxide crosslinkable fluororubber composition of Formulations F-1 to F-5 were kneaded with an open roll. After that, for the acrylic rubber composition, a dispensing sheet having a thickness of about 4 mm was prepared. From this, an uncrosslinked sheet of 105 × 135 × 4 mm was cut out, and for the fluororubber composition, a dispensing sheet having a thickness of about 2 mm was prepared. An uncrosslinked sheet of 105 × 135 × 2 mm was cut out from this.

<Production of rubber laminate>
A PTFE sheet (140 x 20 mm, thickness 50 μm) is attached to the upper side of the acrylic rubber uncrosslinked material sheet, and then the fluororubber uncrosslinked sheet is overlaid to form the air chuck gripping part during the peel test. An uncrosslinked rubber laminate was produced. This was put in a mold (110 × 140 × 5.5 mm), pressure-crosslinked at 160 ° C. for 30 minutes, and then subjected to secondary crosslinking in an oven at 175 ° C. for 4 hours to obtain a rubber laminate used for a peel test. .

About the obtained rubber laminated body, the peeling test was done as follows.
The rubber laminate is punched into a strip with a width of 15 mm and a length of 80 mm, and both ends of this air chuck gripping part are gripped with an air chuck of a tensile testing machine (Strograph E II, manufactured by Toyo Seiki Seisakusho), 180 at a speed of 50 mm / min. A peel test was performed to determine the peel strength (unit: N / mm).

  Moreover, the peeling state was evaluated by visually observing the situation of the adhesion interface after the peeling test. The situation of the adhesive interface means that the higher the peel strength of the peeled surface after the peel test is, and when the situation of the adhesive interface is “rubber breakage”, the rubber laminate is excellent in cross-linking adhesion.

  The interface peeling rate is an approximate value calculated by an area ratio (interface peeling area / total peeling area) by visual observation of the interface.

  The interface peeling rate of 100% means that one rubber layer does not remain at the other rubber layer, that is, each rubber layer is peeled along the interface without being destroyed. It was determined as “interface peeling”.

  Interfacial peeling rate of 0% means that one rubber layer is completely left on the other rubber layer, that is, one rubber layer has been completely destroyed. Judged.

  0% <interfacial peeling rate <100% means that interfacial peeling and rubber breakdown are mixed along the peeling surface, and the peeling mode was determined as partial interfacial peeling (abbreviated as partial).

The composition of the rubber laminate and the results of the peel test are shown in Table 4 below.
Table 4
Rubber laminate composition peel test
Acrylic rubber Fluoro rubber Peel strength Interfacial peel rate Peel
Example composition composition (N / mm) (%) Embodiment
Comparative Example 1 A-1 F-1 2.6 100 Interfacial peeling 〃 2 A-2 F-2 5.4 30 Partial
Example 1 A-3 F-3 6.5 0 Rubber failure comparison example 3 A-4 F-3 5.1 0 Rubber failure ４ 4 A-5 F-4 4.7 30 Partial
５ 5 A-6 F-5 4.4 100 Partial
６ 6 B-1 F-1 1.7 100 Interfacial peeling 〃 7 B-2 F-2 3.2 0 Rubber fracture example 2 B-3 F-3 3.7 0 Rubber fracture comparative example 8 B-4 F-3 2.5 100 Interfacial peeling 〃 9 B-5 F-4 1.8 100 Interface peeling 〃 10 B-6 F-5 2.1 100 Interface peeling

From the above results, the following can be said.
(1) From the comparison of Example 1-Comparative Example 3 and Example 2-Comparative Example 8, in addition to 1,3-diallyl-5-glycidyl isocyanurate and 1,4-diazabicyclo [2.2.2] octane, It can be seen that the peel strength is improved by adding stearylamine (primary amine).
(2) From the comparison of Example 1-Comparative Examples 4-5 and Example 2-Comparative Examples 9-10, regarding the peel strength, 1,3-diallyl-5-glycidyl isocyanurate is 1-allyl-3,5 -It is found that it is more effective for cross-linking adhesion between acrylic rubber and fluororubber than diglycidyl isocyanurate or triglycidyl isocyanurate.

Claims (5)

(A) carboxyl group-containing acrylic rubber, (B) 1,3-diallyl-5-glycidyl isocyanurate, (C) 1,4-diazabicyclo [2.2.2] octane, (D) general formula RNH ₂ (where R is a C1-C30 aliphatic hydrocarbon group) and (E) a carboxyl group-containing acrylic rubber composition layer comprising a carboxyl group-containing acrylic rubber crosslinking agent, and
(a) an organic peroxide crosslinkable fluororubber, (b) 1,3-diallyl-5-glycidyl isocyanurate, (c) 1,4-diazabicyclo [2.2.2] octane, (d) triallyl isocyanurate and (e) A rubber laminate obtained by crosslinking and bonding an organic peroxide crosslinkable fluororubber composition layer containing an organic peroxide crosslinking agent.   (B) component is 0.05 to 5 parts by weight, (C) component is 0.01 to 5 parts by weight, and (D) and (E) components are each 0.1 to 5 parts by weight with respect to 100 parts by weight of component (A). In addition, with respect to 100 parts by weight of component (a), component (b) is 0.05 to 5 parts by weight, component (c) is 0.01 to 5 parts by weight, component (d) is 0.1 to 10 parts by weight, and component (e) The rubber laminate according to claim 1, wherein 0.1 to 5 parts by weight is used. The rubber laminate according to claim 1 or 2, wherein the primary amine represented by the general formula RNH ₂ is stearylamine.   The rubber laminate according to claim 1 or 2, wherein the carboxyl group-containing acrylic rubber crosslinking agent is a polyvalent amine compound or a derivative thereof. The rubber laminate according to claim 4, wherein the polyvalent amine compound or a derivative thereof is hexamethylenediamine carbamate.