JPH0224210B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a laminate having a fluororubber layer, and more specifically, a method of bringing a fluororubber compound layer containing a specific crosslinking agent into contact with another crosslinkable polymer compound layer and heating the layer. The present invention relates to a method for manufacturing a laminate. In recent years, gas hole resistance and sour gasoline resistance have become more important as characteristics required for fuel hoses. Therefore, a material in which a layer of a fluororubber compound having particularly excellent properties as described above is laminated on a layer of a general rubber compound is attracting attention. On the other hand, the present inventor has reported many methods for manufacturing laminates consisting of dissimilar rubber layers or metal and rubber layers by heating alone without using adhesives [for example, Japan Adhesive Association Journal Vol. 17, 98308
(1981)], but the reality is that when the rubber layer is made of fluorocarbon rubber, it is not always possible to obtain a laminate with excellent adhesive strength. As a result of thorough examination of the crosslinking reactivity of fluorocarbon rubber, the inventors of the present invention have found that a laminate with excellent adhesive strength can be obtained by using a compound containing a novel crosslinking agent for the fluorocarbon layer. The present invention was achieved by discovering that That is, according to the invention, a layer of a fluororubber compound containing a di- or trithiol-S-triazine compound, a phosphonium salt and a compound of a group A, A, B or A metal of the Periodic Table and another crosslinkable polymer compound. A method for producing a laminate is provided, which comprises heating the laminate by bringing the layers into contact with each other. The fluororubber used in the present invention is a polymer rubber of a fluorine-containing unsaturated monomer such as tetrafluoroethylene, hexafluoropropylene, trifluorochloroethylene, vinyl fluoride, vinylidene fluoride, or the like. It is a copolymer rubber made of a monomer and other copolymerizable monomers. The di- or trithiol-S-triazine compound used as a crosslinking agent for fluoro rubber has the general formula [X and Y are hydrogen, alkali metals, or alkaline earth metals; R is OR ₁ , SR ₁ , NR ₁ R ₂ ; R ₁ and R ₂ are hydrogen or have a carbon number of 1 to 20, which may contain a substituent, preferably 1 to 8 hydrocarbon residues, R ₁ and R ₂
may be connected at the other end to form a ring. ] Selected from the compounds shown below. Here, the hydrocarbon residues constituting R ₁ and R ₂ include methyl,
Alkyl groups such as ethyl, butyl, and ethylhexyl, cycloalkyl groups such as cyclohexyl, aralkyl groups such as benzyl, methylbenzyl, and ethylbenzyl, and aryl or substituted aryl groups such as phenyl, naphthyl, butylphenyl, and hydroxy-di-t-butylphenyl. , allyl, oleyl, and other alkenyl groups. R ₁
Examples of compounds in which R 2 and R ₂ are connected at the other end to form a ring include morpholino, piperidyl, pipecolyl, and the like. From the point of view of reactivity, X and Y
It is preferable that at least one of the above is an alkali metal or an alkaline earth metal, and that R is NR ₁ R ₂ (the number of carbon atoms in R ₁ and R ₂ is 1 to 8). Specific examples of the compound include trithiocyanuric acid; 2-
Methoxy, 2-ethoxy, 2-phenoxy, 2
-butylamino-, 2-anilino, 2-naphthylamino-, 2-dimethylamino-, 2-diethylamino-, 2-dibutylamino-, 2-diphenylamino-, 2-dicyclohexylamino-, 2
-morpholino- or 2-piperidyl-4,6-dithiol-S-triazine; lithium salts, sodium salts, potassium salts, calcium salts, magnesium salts, barium salts, etc. of these triazines can be mentioned. The phosphonium salt has the general formula [R ₁ R ₂ R ₃ R ₄ P] Z [R ₁ , R ₂ , R ₃ , and at least one of R ₄ is a hydrocarbon residue having 1 to 20 carbon atoms that may contain a substituent. Others may be primary to tertiary amino groups or fluoroalkyl groups. Z is halogen. ] and complex salts of this compound. Here, the hydrocarbon residues constituting R ₁ , R ₂ , R ₃ , and R ₄ include methyl, ethyl, butyl,
Examples include alkyl groups such as ethylhexyl and dodecyl, cycloalkyl groups such as cyclohexyl, aralkyl groups such as benzyl and methylbenzyl, and aryl or substituted aryl groups such as phenyl, naphthyl and butylphenyl. Examples of secondary to tertiary amino groups include methylamino, ethylamino, anilino, dimethylamino, and diethylamino, and examples of fluoroalkyl groups include trifluoromethyl, tetrafluoropropyl, and octafluoropentyl. Specific examples of the above compounds include tetrabutyl, tetraoctyl, methyltrioctyl, butyltrioctyl, phenyltributyl, benzyltributyl, benzyltricyclohexyl, benzyltrioctyl, butyltriphenyl, and octyltributyl. enyl, benzyltriphenyl, tetraphenyl, diphenyl di(diethylamino)
-, phenylbenzyl di(dimethylamino)-,
Examples include phenylbenzyldi(diethylamino)-, trifluoromethylbenzyl-, tetrafluoropropyltrioctyl-phosphonium chloride or bromide. Examples of complex salts include salts of the above compounds with boron trihalide, sulfuric acid, sulfurous acid, carbonic acid, silicic acid, carboxylic acid, and the like. In addition, compounds of metals in group A, A, B or group A of the periodic table can be used as long as they are acid-accepting; specific examples include oxides of magnesium, calcium, zinc, silicon, and lead. , lithium, sodium, potassium, magnesium,
Calcium, strontium, barium, zinc hydroxide, sodium, potassium, magnesium, calcium, strontium, barium, zinc, lead carbonate, magnesium, barium, lead silicate, magnesium, lead sodium phosphite , potassium, calcium, barium, zinc,
Examples include organic acid salts such as tin, lead acetates, caprylates, octylates, laurates and stearates. The amount of each compound used in the present invention per 100 parts by weight of fluororubber is usually 0.1 to 10 parts by weight of di- or trithiol-S-triazine compound, preferably 0.5 to 5 parts by weight, and 0.1 to 5 parts by weight of phosphonium salt.
10 parts by weight, preferably 0.5 to 5 parts by weight, metal compound
The amount is 0.5 to 20 parts by weight, preferably 1 to 10 parts by weight. The polymer forming the other crosslinkable polymer compound layer laminated with the fluoro rubber compound layer is selected appropriately depending on the application, but is usually a halogen-containing polymer or a polymer with carbon-carbon double bonds. Polymers with Examples of halogen-containing polymers include epihalohydrin polymers, copolymers of epihalohydrin and other saturated or unsaturated epoxides, polychloroprene rubber, chlorinated polyolefins, chlorosulfonated polyolefins, halogenated butyl rubber, and vinyl chloride polymers. Examples include. Polymers having carbon-carbon double bonds include butadiene polymers, styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, isoprene polymers, natural rubber, acrylonitrile-butadiene-styrene copolymers, and ethylene. -propylene-ethylidenonbornene or dicyclopentadiene copolymer. The crosslinking agent added to these polymers is appropriately selected depending on the polymer used, but from the viewpoint of adhesive strength with the fluororubber compound, it is preferable to use one that also acts as a crosslinking agent for the fluororubber. Above all, the di- or trithiol-S-triazine compound used as a crosslinking agent for fluororubber in the present invention is particularly preferred since it is a crosslinking agent common to the halogen-containing polymers or polymers having carbon-carbon double bonds. When this triazine compound is used (the amount used is usually 0.1 to 10 parts by weight per 100 parts by weight of the polymer), a particularly strongly bonded laminate can be obtained by contact heating both layers. this is,
In addition to acting as a so-called interlayer transfer catalyst, in which the phosphonium salt added to the fluororubber layer moves to the other polymer layer and reacts with the molecular chains of the polymers in both layers (co-crosslinking), the phosphonium This is thought to be due to the fact that the salt is difficult to decompose even under the high temperatures encountered during adhesion of both layers or during post-crosslinking. Therefore, depending on the type of polymer and crosslinking agent used in the other polymer layer, it may be preferable to incorporate a phosphonium salt into this layer as well. In addition, if the compatibility and crosslinking speed of the fluoro rubber and the other polymer are different, the two layers become more compatible when they are melted by contact heat and before crosslinking progresses.
In addition, by providing a crosslinking induction period to the polymer having a higher crosslinking rate so that the crosslinking properties of the two are similar, the adhesive force between the two layers can be further strengthened. To achieve this, since fluorocarbon rubber generally has a lower crosslinking speed, it is possible to match the crosslinking speed to that of fluorocarbon rubber by adding a crosslinking-inhibiting compound to the other polymer. [This adjustment of the crosslinking rate was reported in the Japan Rubber Association Journal, Vol. 54, p. 201 (1981)]. The crosslinking-inhibiting compound may include di- or trithiol-S-, although it depends on the type of crosslinking agent used.
When a triazine compound is used, examples include 2-benzothiazolyl disulfide, 4,4'-dithiodimorpholine, and cyclohexylthiophthylimide. The amount to be used can be determined as appropriate, usually within a range of 5 parts by weight or less per 100 parts by weight of the polymer. Fluororubber compounds and other crosslinkable polymer compounds may contain other known additives, such as crosslinking agents, crosslinking accelerators, reinforcing agents, fillers, softeners, plasticizers, aging agents, etc., depending on the purpose. Inhibitors, stabilizers, processing aids, and the like may be included. Both blend layers are brought into contact in an uncrosslinked state, and usually 2
A crosslinked laminate is obtained by heating to 100-200° C. under a pressure of ˜50 Kg/cm ² . It is also possible to shorten the primary crosslinking time and improve adhesive strength by heat-treating (post-curing) the laminate. Next, the present invention will be explained with reference to examples. Number of copies is based on weight. Example 1 After preparing various compounds according to the formulations shown in Table 1, a fluororubber compound layer (1 mm thick) and another polymer compound layer (2 mm thick) are shown in Table 2. A laminate was prepared by laminating the combination and hot pressing at 160° C. for 30 minutes or post-curing after hot pressing. Next, 10 mm width increments were made on this material and a T-shaped peel test was conducted in accordance with JIS-K 6854-1973. The results are shown in Table 2.

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[Table] As is clear from Table 2, the laminate of the present invention exhibits excellent peel strength. On the other hand, when a fluororubber compound containing no phosphonium salt is used, no adhesive strength is obtained. Example 2 After preparing various compounds according to the formulations shown in Table 3, a fluoro rubber compound layer (1 mm thick) and an acrylonitrile-butadiene copolymer rubber compound layer (2 mm thick) were added to a fourth layer. Laminated in the combination shown in the table, 160
Laminates were prepared by press crosslinking for 30 minutes at °C. Next, the peel strength of this product was measured in the same manner as in Example 1. The results are shown in Table 4.

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[Table] From Table 4, although there were differences in peel strength depending on the combination, laminates with excellent adhesive strength were obtained in all cases. Example 3 The peel strength of the laminate was measured in the same manner as in Example 2, except that the compositions with the formulations in Table 5 were laminated in the combinations in Table 6.As shown in Table 6, the peel strength of the laminate was measured. The body also showed excellent adhesion.

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Claims (1)

[Claims] 1 Di- or trithiol-S-triazine compounds, phosphonium salts and periodic table A, A,
A method for producing a laminate, which comprises heating a fluororubber compound layer containing a Group B or A metal compound and another crosslinkable polymer compound layer by bringing them into contact with each other.