JPS63252736A - Manufacture of rubber laminate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a method for producing a rubber laminate, and more specifically, the present invention relates to a method for producing a rubber laminate, and more specifically, vulcanization by bringing fluororubber containing a specific compounding agent into contact with acrylonitrile-butadiene rubber. The present invention relates to a method for producing the laminate, which comprises adhesion.

(Prior Art) In recent years, gasohol resistance and sour gasoline resistance have become more important as characteristics required for fuel hoses.

Fluororubber has excellent properties such as heat resistance, oil resistance, solvent resistance, and chemical resistance, and is used as a comb with excellent gasohol resistance and sour gasoline resistance. However, while fluororubber has these excellent properties,
It has the drawbacks of being more expensive than other rubber materials such as acrylonitrile-getadiene rubber (hereinafter abbreviated as NBR) and having poor cold resistance. 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.

However, fluororubber and NBR do not adhere to each other by vulcanization using normal methods, or have very weak adhesive strength, and a laminate with excellent adhesive strength has not necessarily been obtained.

For this reason, there is a method of incorporating metal oxides, silica-based fillers, and/or epoxy resins into NBR (published patent publication No. 56-53066), and furthermore, 1,8-diazabicyclo[5,4,0]undecene of caldicic acid. A method of blending 7 salts (published patent publication, 1982-162335) has been proposed, but due to the inclusion of large amounts of magnesium oxide and silica fillers, there are restrictions in the blend design.
In addition, it may have an adverse effect on physical properties.

(Problems to be Solved by the Invention) As a result of intensive research to solve the above-mentioned drawbacks, the present inventors have developed a formulation in which fluororubber contains a metal oxide and a formulation in which NBR contains a specific phosphonium salt. The inventors discovered that by vulcanizing and adhering objects, a laminate in which a fluororubber vulcanizate and an NBR vulcanizate are firmly bonded can be obtained, and based on this knowledge, the present invention was completed. .

(Means for Solving the Problems) Thus, according to the present invention, an unvulcanized compound in which fluororubber contains a metal oxide and an unvulcanized compound in which NBR contains a phosphonium salt represented by the following general formula. A method for producing a rubber laminate is provided, which comprises contacting and vulcanizing a compound.

(R1+ R2+ R3+ R4 is a hydrocarbon residue having 1 to 20 carbon atoms that may contain a substituent. However, R4,
Up to three of R2゜R3 and R4 may be primary to tertiary amine groups or fluoroalkyl groups. R5 is hydrogen or an alkyl group having 1 to 20 carbon atoms) The fluororubbers used in the present invention include vinylidene fluoride, hexafluoropropene, tetrafluoroethylene, pentafluoropropene, and to! Polymer rubbers of fluorine-containing unsaturated monomers such as refluoroethylene, trifluorochloroethylene, vinyl fluoride, perfluoromethyl vinyl ether, perfluoromethyl vinyl nityl, or other copolymerizable monomers. It is a copolymer comb with a monomer. Among these, vinylidene fluoride-hexafluorogopene binary copolymer rubber and vinylidene fluoride-hexafluorogopene-tetrafluoroethylene terpolymer rubber are particularly preferred.

The NBR used in the present invention is a copolymer rubber consisting of acrylonitrile and getadiene, and as for the bonded acrylonitrile content, commercially available ones having a low nitrile to very high nitrile can be used.

Metal oxides used as components of the vulcanization system of fluororubber include CaO, MgO, PbO, Pb3O4, Ba
d.

Although At205 and the like are used, MgO is particularly preferred.

The amount used is 1 to 30 parts per 100 parts by weight of fluororubber.
The compound is selected from the following compounds according to the weight part and the vulcanization system of the fluororubber.

Here, the hydrocarbon residues constituting R1r R2+ R3+ R4 include alkyl groups such as methyl, ethyl, butyl, ethylhexyl, and dodecyl, cycloalkyl groups such as cyclohexyl, aralkyl groups such as benzyl and methylbenzyl, phenyl, naphthyl, Examples thereof include a group such as gtylphenyl, a substituted aryl group, and the like. Examples of secondary to tertiary amino groups include methylamino, ethylamino, anilino, dimethylamino, and diethylamino, and examples of fluoroalkyl groups include trifluoromethyl, tetrafluoropropyl, octafluoropentyl, and the like. Examples of R5 include alkyl groups such as methyl, ethyl, butyl, ethylhexyl, and dodecyl.

Specific examples of the above compounds include tetrabutyl, tetraoctyl, methyltrioctyl, butyltrioctyl, phenyltrigutyl, benzyltrigutyl,
Benzyltricyclohexyl-, benzyltrioctyl, glylttriphenyl-, octyltripheny, benzyltriphenyl-, tetraphenyl-, nophenylzo(diethylamino)-, phenylpenzylso(dimethylamino)-, phenylpenzyldi (diethylamino)-
, trifluoromethylpentrue, tetrafluoropropyltrioctyl-phosphonium benzotriazole or tolyltriazole. The lid used is NB.
If the ratio is less than 1 part by weight per 100 parts by weight, the laminate with good adhesive strength cannot be obtained;
If it exceeds 10 parts by weight, the vulcanization rate of NBR will be significantly reduced and it cannot be put to practical use. Further, even if the phosphonium salt is simultaneously incorporated into the fluororubber, a similarly strong adhesive vulcanizate can be obtained.

The fluororubber compound and the NBR compound may each contain other known additives depending on the purpose, such as a crosslinking agent, a crosslinking accelerator, a reinforcing agent such as carcin black or silica, a filler, a softener, a plasticizer, Anti-aging agents, stabilizers, processing aids, etc. may be included.

To give a specific example of the method for manufacturing the rubber laminate of the present invention, a fluororubber vulcanization compound and an NBR vulcanization compound are kneaded by a known method and formed into a sheet of appropriate thickness. Next, both compound layers are brought into contact in an unvulcanized state, and pressure vulcanization is performed using a hot press or a vulcanizing can to vulcanize and bond both rubber sheets.

It is also possible to form both of the above-mentioned compositions into a laminated tube by a two-layer extrusion method, and then press and vulcanize the tube using a vulcanizer.

Hot press is usually 20-1 at a temperature of 140-200℃.
It is carried out for 5 to 60 minutes under a pressure of 50 kg/c-. When using a vulcanizer, the temperature is usually 130-160'C, 1
．． Pressure vulcanization is carried out for 30 to 120 minutes under a pressure of 8 to 5.5 mm/cm2. Furthermore, by heat-treating (post-curing) the obtained laminate, it is possible to shorten the post-vulcanization time and improve the compression set.

(Effect of the invention) Thus, according to the present invention, fluororubber vulcanizate and NBR2
10 It is possible to obtain a laminate in which sulfur is firmly adhered,
It is possible to significantly improve the price and low-temperature properties while maintaining the excellent performance of fluororubber.

The laminate of the present invention exhibits excellent gasoline resistance, especially sour gasoline resistance, of fluororubber, and by utilizing this property, it can be used as a fuel hose material and diaphragm material, as well as having oil resistance and resistance to sour gasoline. Can be used for various rubber parts with excellent chemical resistance.

(Example) The present invention will be described in more detail with reference to Examples below. In addition, the parts and divisions in Examples and Comparative Examples are based on the weight of an unbroken hook.

Example 1 The NBR compound shown in Table 1 and the fluororubber compound shown in Table 2 were kneaded using a 6-inch open roll to prepare a sheet having a uniform thickness of about 2 sieves. Next, cut each strip into f 6 cm x 106n square strips.
A maple fan body was prepared by laminating the combinations shown in the table and vulcanizing and adhering them at a press pressure of 40 and 9/crn2 at 170° C. for 15 minutes. During the peel test, cellophane paper was placed in advance at the part to be gripped by the chuck to prevent the two sheets from adhering. Next, this test piece was subjected to a peel test according to JIS K6301 at a tensile rate of 50 wn/min to measure the peel strength. The results obtained are shown in Table 3.

Table 3 shows that according to the present invention, fluororubber and NBR are laminated with strong adhesive strength.

Table 2 *1 Technoflon FOR8OE (manufactured by Monteflos →
*2 Technoflon FOR45 (manufactured by Monteflos) No.
3 Table Example 2 The NBR compound shown in Table 4 and the fluororubber compound shown in Table 5 were mixed in the method shown in Example 1, and then a test piece was molded and the peel strength was measured.

The results are shown in Table 6. As a result, by making NBR contain 1.0 parts by weight or more of a specific phosphonium salt and making fluororubber contain a metal oxide, a rubber laminate in which 9 NBR and fluorine rubber are firmly vulcanized and bonded can be created. Obtainable.

Table 5 *3 Manufactured by Montefloss *4 〃 Table 6 Example 3 After mixing the NBR composition shown in Table 7 and the fluoropum composition shown in Table 8 in the method shown in Example 1, a test piece was prepared. It was molded and its peel strength was measured.

The results are shown in Table 9. As a result, by the method of the present invention, N
It is understood that a rubber laminate in which the BR vulcanizate and the fluororubber vulcanizate are firmly adhered can be obtained.

Table 8 Table 9

Claims (1)

[Scope of Claims] 1. Contacting an unvulcanized compound in which fluororubber contains a metal oxide and an unvulcanized compound in which acrylonitrile-butadiene rubber contains a phosphonium salt represented by the following general formula. A method for producing a rubber laminate, characterized by vulcanization. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (R_1, R_2, R_3, R_4 are hydrocarbon residues with 1 to 20 carbon atoms that may contain substituents. However, R
Up to three of _1, R_2, R_3, R_4 are 1 to
It may also be a tertiary amino group or a fluoroalkyl group. R_5
is hydrogen or an alkyl group having 1 to 20 carbon atoms. )