JP2746415B2 - Laminate - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an elastomer laminate having excellent durability. More specifically, the present invention relates to a laminate of an acrylic elastomer and a fluoroelastomer.

(Prior Art) Conventionally, for rubber parts that come into contact with fuel oil, rubber materials that do not impair durability even when they come into contact with the fluid have been selected and used. For example, a fuel oil hose is made of nitrile rubber (hereinafter referred to as NBR), which has excellent oil resistance, and chlorsulfonated polyethylene (hereinafter, CSM), which has excellent heat resistance, is placed in the inner tube.
In recent years, due to various technological innovations, the temperature in the engine room of an automobile has been increasing, and the fuel oil has deteriorated, and as a result, the rubber tends to deteriorate. In other words, NBR has insufficient oil resistance as a material for the inner tube of the fuel oil hose, and the CSM of the outer tube sometimes has insufficient heat resistance and the like, so that a material with higher durability has been desired.

Therefore, for rubber parts used in contact with fuel oil, the surface that comes into contact with fuel oil is the most durable, but an expensive fluoroelastomer is provided, and the durability is higher than that of NBR and CSM on the outside. Practical application of a laminate (hose, diaphragm, etc.) in which an acrylic elastomer, which is expensive and less expensive than a fluoroelastomer, is arranged to further improve the balance between price and performance is being studied.

(Problems to be Solved by the Invention) However, if the fluoroelastomer and the acrylic elastomer are simply superposed and vulcanized, the interface between the fluoroelastomer and the acrylic elastomer hardly adheres to each other, and the fluorine-based elastomer and the acrylic elastomer hardly adhere to each other. There is a problem that the interface between the elastomer and the acrylic elastomer is peeled off, and the durability as a laminate is not realized. An object of the present invention is to provide a laminate that solves this problem.

(Means for Solving the Problems) The present inventor provides a radical inhibitor by forming a composition containing a peroxide, a quaternary ammonium bromide and sodium acrylate or sodium methacrylate in an acrylic elastomer. The vulcanized adhesive strength with a composition containing a fluorine-based elastomer containing, was improved, and a composite suitable for various uses used under various severe conditions could be obtained.

That is, the present invention provides an acrylic elastomer composition layer containing an acrylic elastomer, a peroxide, a quaternary ammonium bromide and sodium acrylate or sodium methacrylate, and a composition layer containing a fluorine-based elastomer containing a radical inhibitor. Provides a laminate obtained by vulcanization bonding.

The acrylic elastomer used in the laminate of the present invention is a polymer of acrylate and / or methacrylate (hereinafter referred to as (meth) acrylate) or (meth) acrylate and α-olefin, halogenated olefin (Including vinyl halide), copolymers with acrylonitrile, vinyl fatty acid, aromatic vinyl and diene compounds, and modified products thereof.

Examples of the (meth) acrylate for producing the acrylic elastomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, and ( 2-ethylhexyl (meth) acrylate, n- (meth) acrylate
Decyl, n-dodecyl (meth) acrylate, n-octadecyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 1-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate,
Examples include methoxymethyl (meth) acrylate, ethoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, and butoxyethyl (meth) acrylate.

Examples of the fatty acid vinyl copolymerized with the acrylate include vinyl acetate and vinyl propionate.

As the peroxide, those used for rubber crosslinking can be used and are not particularly limited. For example, di-t-butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, α, α′-bis ( t-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-
2,5-di (t-butylperoxy) hexyne-3,1,1-
Bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, n-butyl-4,4-bis (t-butylperoxy) valerate, 2,2-bis (t-butylperoxy) butane, 2,2-bis (t-butylperoxy) octane. Although the amount of the peroxide is not limited, it is usually used in an amount of about 1 to 10 parts by weight based on 100 parts by weight of the acrylic elastomer.

As the quaternary ammonium bromide, tetramethylammonium bromide, tetraethylammonium bromide, tetrapropylammonium bromide,
Examples thereof include tetrabutylammonium bromide, octadecyltrimethylammonium bromide, cetyltrimethylammonium bromide, and dodecyltrimethylammonium bromide.

The quaternary ammonium bromide is preferably used in an amount of 0.3 part by weight or more based on 100 parts by weight of the acrylic elastomer, and good adhesive strength can be obtained at the laminated portion of the laminate.

Examples of the radical inhibitor include, in addition to polymerization inhibitors and stabilizers generally used industrially, various substances that have an effect of inhibiting the action of organic peroxides, such as sulfur and rubber used for vulcanization of rubber. Accelerators and other organic compounds.

Typical polymerization inhibitors include quinones and mercaptans. Examples of quinones include hydroquinone, methylhydroquinone, 2-tert-butylhydroquinone, hydroquinone monomethyl ether, p-benzoquinone, and methyl-p.
-Benzoquinone and the like. 1 of mercaptans
Examples include n-dodecyl mercaptan, t-dodecyl mercaptan.

As a stabilizer, a rubber antioxidant is generally used,
Amine-ketone system, aromatic secondary amine system, monophenol system, bisphenol system, polyphenol system, benzimidazole system, dithiocarbamate system, thiourea system, phosphorous acid system, organic thioacid system, and other organic compounds is there.

Examples of the amine-ketone system include poly (2,2,4-trimethyl-1,2-dihydroquinone) and a reaction product of diphenylamine and acetone.

One example of an aromatic secondary amine is 4,4'-
(Α, α-dimethylbenzyl) diphenylamine, N,
N'-di-2-naphthyl-p-phenylenediamine and the like.

One example of the monophenol type is 2,6-di-tert-
High-molecular-weight phenols having a high-molecular-weight substituent other than butyl-4-methylphenol, mono (or di- or tri-) (α-methylbenzine) phenol can be mentioned.

Examples of bisphenols include 2,2'-methylenebis (4-ethyl-6-tert-butylphenol),
4'-thiobis (3-methyl-6-tert-butylphenol) and the like.

One example of polyphenols is 2,5-di-tert-
Butyl hydroquinone, 2,5-di-tert-amyl hydroquinone and the like can be mentioned.

Examples of benzimidazoles include 2-mercaptobenzimidazole and 2-mercaptomethylbenzimidazole.

Examples of thiocarbamate salts include nickel diethyldithiocarbamate, nickel dibutyldithiocarbamate and the like.

Examples of thiourea-based compounds include 1,3-bis (dimethylaminopropyl) -2-thiourea and tributylthiourea.

An example of the phosphorous acid system is tris (nonylphenyl) phosphite.

One example of organic thioacids is dilauryl thiodipropionate.

Other organic compounds as stabilizers include p-quinone dioxime, 4,4'-dithiodimorpholine, o, o'-
Examples include dibenzamide diphenyl disulfide and zinc salts of 2-benzamide thiophenol.

Rubber vulcanization accelerators include aldehyde ammonia, aldehyde amine, thiourea, guanidine, thiazole, sulfenamide, thiuram,
Representative examples include dithiocarbamates and xanthates.

An example of an aldehyde ammonia type is hexamethylenetetramine; an example of an aldehyde amine type is
n-butyraldehyde aniline; examples of thioureas include trimethylthiourea, N, N'-diethylthiourea, ethylenethiourea; examples of guanidines include 1,3-diphenylguanidine and dicatechol borate di-o. -Tolylguanidine salt; thiazole-based 1
Examples include 2-mercaptobenzothiazole,
(2 ', 4'-dinitrophenylthio) benzothiazole; examples of sulfenamides include N-cyclohexyl-2-benzothiazolylsulfenamide; examples of thiurams include tetramethylthioram disulfide; Dipentamethylene thiuram tetrasulfide; examples of dithiocarbamate salts include zinc dimethyldithiocarbamate and copper dimethyldithiocarbamate; examples of xanthate salts include zinc butylxanthate and zinc isopropylxanthate; And other organic compounds include 2-methylimidazole and the like.

It is preferable to add the radical inhibitor in an amount of 0.1 part by weight or more based on 100 parts by weight of the fluoroelastomer. Usually, it is more preferably from 0.2 to 10 parts by weight, most preferably from 0.2 to 5 parts by weight. 1
Attention must be paid to the case where a high adhesive strength is exhibited by adding an amount exceeding 0 parts by weight, since this may adversely affect other properties of the vulcanized fluoroelastomer.

To the acrylic elastomer composition, in addition to the acrylic elastomer, peroxide and quaternary ammonium bromide, sodium acrylate or sodium methacrylate is added. It is preferably at least 0.1 parts by weight, the addition of 0.1 parts by weight is sufficient adhesive strength of the laminated portion of the laminate, the addition of more than necessary tends to gradually lose the mechanical strength of the acrylic elastomer composition. Become. The preferred addition amount is 2 parts by weight or more and 20 parts by weight or less.

The acrylic elastomer composition can be produced by kneading the above-mentioned materials by a method commonly used in the rubber industry, for example, an open roll or a closed mixer.

As the composition of the fluorine-based elastomer, a copolymer of chlorotrifluoroethylene and vinylidene fluoride, a copolymer of tetrafluoroethylene and propylene, 1,2,3,
3,3-pentafluoropropene and vinylidene fluoride copolymer, hexafluoropropylene and vinylidene fluoride copolymer, terpolymer of vinylidene fluoride, hexafluoropropylene and tetrafluoroethylene, etc. There are trade names such as K-F elastomer of 3M, Technoflon of Monte Edison, Florel of 3M, Viton of Dupont, and Daiel of Daikin Industries.

The composition of the fluoroelastomer is obtained by adding a reinforcing agent, a filler, a vulcanizing agent and other commonly used compounding agents to the fluoroelastomer.

In order to obtain a laminate, the acrylic elastomer composition and a composition containing a fluorine-based elastomer are bonded together,
There is a method of coating with an extruder, and these composites are heated and vulcanized.

Vulcanization of the composite depends on the half-life of the peroxide used,
Time and temperature for sufficient crosslinking are required. If necessary, heat treatment of the primary vulcanizate again in an air oven followed by vulcanization is a preferred method for obtaining a stable vulcanizate.

In the laminate of the present invention, the fluoroelastomer layer has fuel oil resistance and heat resistance, the acrylic elastomer layer has heat resistance, oil resistance and cold resistance, and these layers are firmly bonded by vulcanization bonding. , Extremely high durability.

Applications of this laminate include air hoses, fuel oil hoses, various control hoses, hoses or tubes such as radiator hoses, electric wire coatings, diaphragms, etc. Elastomer layers are used laminated on the inside or vice versa. Further, other elastomers may be further laminated outside these two types of elastomer layers.

In particular, for fuel oil hoses or tubes of automobiles that require fuel oil resistance, use a fluoroelastomer for the inner layer,
A laminate using an acrylic elastomer for the outer layer is most preferred.

(Examples) The effectiveness of the present invention will be described below with reference to examples.

Examples 1 to 30, Comparative Example 1 As a fluorine-based elastomer, Daiel G703 (manufactured by Daikin Industries, Ltd.) and Daiel G603 (manufactured by Daikin Industries, Ltd.) were used. A blend was prepared with an 8 inch roll according to the blending recipes shown in Tables 2, 3 and 4 and sheeted, and both unvulcanized rubber sheets were laminated.
Press vulcanization was performed for 0 minutes to prepare a vulcanized product, and the adhesive strength was measured. The adhesive strength of the laminate was measured according to JIS K6301.

The acrylic ester copolymer used was manufactured as follows. That is, water is added to the autoclave.
43 kg, acrylonitrile 4 kg, methoxyethyl acrylate 36 kg, electrified poval B-05 as polyvinyl alcohol
And 700 g of each of B-17, 60 g of sodium acetate, 2 g of ferrous sulfate, 4 g of ethylenediaminetetraacetic acid, and 90 g of sodium thiosulfate were stirred and mixed, and the internal temperature of the autoclave was adjusted to 45 ° C.
The air above the autoclave was replaced with nitrogen.

Separately, an aqueous solution of a polymerization initiator was injected from an injection port to advance polymerization, and the injection was completed in 12 hours. An aqueous solution of Glauber's salt was added to the resulting polymer emulsion to coagulate the polymer, which was washed with water, dried and dried, and the polymer was tested as an acrylic ester copolymer.

As shown in Tables 2 and 3, the system using peroxide and quaternary ammonium bromide and sodium methacrylate as the acrylic elastomer is replaced with the system not using sodium methacrylate and quaternary ammonium bromide. A sufficient adhesive strength is expressed in comparison.

[Notes] 1) Fluorine elastomer hexafluoropropylene and vinylidene fluoride copolymer (polyol vulcanizing agent containing type) manufactured by Daikin Industries, Ltd. 2) Fluorine elastomer vinylidene fluoride, hexafluoropropylene and tetrafluoropolymer manufactured by Daikin Industries, Ltd. Terpolymer with ethylene (polyol vulcanizing agent-containing type) 3) Naugard 445 manufactured by Uniroyal 4) Polyester plasticizer manufactured by Adeka Argus 5) N-butyl-4,4-bis manufactured by NOF Corporation t-butyl peroxy) valerate 40% product 6) "*" in the column of adhesive strength indicates that the adhesive layer had already been peeled off when the test piece was taken out of the mold when preparing a test piece for measuring the adhesive strength. Indicates that the test failed. "Break" indicates that the acrylic elastomer or the fluorine elastomer was broken during the peeling test.

Claims (1)

(57) [Claims] 1. Acrylic elastomer, peroxide, fourth
A laminate comprising an acrylic elastomer composition layer containing quaternary ammonium bromide and sodium acrylate or sodium methacrylate and a composition layer containing a fluoroelastomer containing a radical inhibitor vulcanized and bonded.