JPH0455106B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a rubber laminate, and more specifically, a rubber compound of ethylene-propylene-nonconjugated diene terpolymer (hereinafter abbreviated as EPDM) using sulfur as a vulcanizing agent and organic peroxide. EPDM or ethylene-propylene copolymer (hereinafter referred to as EPM) is a vulcanizing agent.
The present invention relates to a rubber laminate that is laminated and bonded using an EPDM rubber compound using an organic peroxide as a vulcanizing agent and a rubber compound as an adhesive material. (Conventional technology) EPDM rubber, EPM rubber is natural rubber (NR),
Compared to diene rubbers such as styrene-butadiene rubber (SBR), nitrile rubber (NBR), and chloroprene rubber (CR), it has better heat resistance, weather resistance, ozone resistance, electrical insulation, and chemical resistance to polar solvents. It shows outstanding performance and is used in many fields such as belts, automobile parts, building material parts, electrical parts, and hoses. Among these, EPDM rubber is copolymerized with a third component monomer, such as a non-conjugated diene monomer, so it has relatively high chemical reactivity with EPM and can be vulcanized with sulfur or organic peroxide. Because it has double bonds, its heat resistance is inferior to EPM rubber. On the other hand, since EPM rubber does not contain double bonds in its polymer components, it cannot be vulcanized with sulfur, but it can be vulcanized with organic peroxides. It is a well-known fact that peroxide vulcanization is generally superior to sulfur vulcanization in the heat resistance of rubber, but depending on the purpose of use, it is more appropriate to use sulfur as a vulcanizing agent than organic peroxide. There are cases where In such cases, it is necessary to coat the surface with rubber vulcanized with organic peroxide to reduce heat resistance, but in order to bond the two, an appropriate adhesive technology is required. . However, it is extremely difficult to integrally mold EPDM rubber, which uses sulfur as a vulcanizing agent, and EPM rubber, which uses organic peroxide as a vulcanizing agent, and bond them together at the same time as vulcanization. is still unknown. (Problems to be solved by the invention) Therefore, in view of the above-mentioned facts, the present inventors
The above EPDM rubber using sulfur as a vulcanizing agent or a blend rubber compound of EPDM and diene rubber, and using an organic peroxide as a vulcanizing agent,
The problem was that of integrally molding EPM or EPDM, diene rubber, and a blended Blend compound, and vulcanizing and adhering it, and as a result, we conducted extensive research on the method, and as a result, we decided to use organic peroxide as the adhesive material as a vulcanizing agent. EPDM rubber compound used as or
By using a rubber layer made of a blended rubber compound of EPDM and diene rubber, the sulfur-cured rubber layer and the organic peroxide-cured rubber layer have completely different crosslinking forms, but excellent vulcanization is achieved. The present invention was achieved by discovering that it exhibits adhesive properties. (Means for solving the problem) That is, the feature of the present invention is that EPDM
at least 60 parts by weight in the polymer component,
A rubber compound (A) using sulfur as a vulcanizing agent;
EPDM or EPM in the polymer component at least
60 parts by weight of organic peroxide rubber containing at least 60 parts by weight of EPDM in the polymer component with respect to the formation of an adhesive laminate with a rubber compound (B) using an organic peroxide as a vulcanizing agent. The point is that compound (C) is used as an adhesive material to achieve laminated adhesion. Here, the EPDM used in the present invention is an ethylene-propylene-nonconjugated diene terpolymer, and examples of the nonconjugated diene include ethylidene norbornene, dicyclopentadiene, 1,4
-hexadiene, methylnorbornene, 4,7,
At least 1 8,9-tetrahydroindene, etc.
Included are ethylene-propylene-nonconjugated diene terpolymers containing seeds. Furthermore, the EPM used in the present invention is ethylene-
It is a propylene copolymer, and generally commercially available products can be used. Rubber types that can be blended with EPDM and EPM used in the present invention include natural rubber (NR), styrene-butadiene rubber (SBR), nitrile rubber (NBR), butadiene rubber (BR), and chloroprene rubber (CR). ),
There are butyl rubber (IIR), chlorinated butyl rubber, chlorosulfonated polynytylene (CSM), etc., and the blend ratio is EPDM/other blend rubber weight ratio of 100/0 to 60/40, more preferably 100/0 to 80/
A ratio of less than 60/40 makes vulcanization and adhesion difficult, and the heat resistance is also extremely poor. On the other hand, the type of organic peroxide used in the present invention may be any organic peroxide as long as the crosslinking reaction does not proceed to an extreme extent at the temperature during processing, preferably with a half-life of 10 hours and a decomposition temperature. Dialkyl peroxide with a temperature of 80℃ or higher is preferable. for example,
Di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide,
2,5-dimethyl-2,5-di(t-butylperoxy)-hexane, 2,5-dimethyl-2,5
-di(t-butylperoxy)-hexane-3,
1,3-bis-(t-butylperoxy-isopropyl)benzene, 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, 1,1-di-t-butylperoxycyclohexane , 2,2-di-t-butylperoxybutane, and the like. Further, the amount of organic peroxide is preferably 1/10 to 1/1000 mole based on 100 parts of the polymer; when it exceeds 1/10 mole, scorch tends to occur, and when it is less than 1/1000 mole, crosslinking is difficult to occur. Particularly preferred is 1/50 to 1/500 mole. If necessary, commonly used additives such as carbon black, fillers, anti-aging agents, softeners, zinc white, co-crosslinking agents, vulcanization accelerators, etc. are added to the rubber compound used in the present invention. be able to. (Example) Next, the present invention will be further explained by referring to an example. However, it goes without saying that the present invention is not limited thereby. In addition, all the values of compounding amounts in the examples are parts by weight. (Preparation of rubber compound) According to each formulation in Table 1, Table 3, Table 5, and Table 7, a masterbatch is mixed in a Banbury mixer, and the vulcanization system is mixed in a roll to form a rubber compound. created something. Using the above rubber compound, various tests were conducted and evaluated in the following manner. (Adhesion test) Unvulcanized rubber compound using sulfur as vulcanizing agent
(A) and an unvulcanized rubber compound (B) using an organic peroxide as a vulcanizing agent are rolled into a sheet to a thickness of 4.0 mm, and in between, as an adhesive material, a sheet is rolled to a thickness of 0.5 mm. An unvulcanized rubber (C) using an organic peroxide is sandwiched between the vulcanizing agent for the intermediate layer, which is then integrally molded, placed in a mold, press vulcanized at 165℃ for 30 minutes, and then left to cool. It was cut to 25 mm and used as an adhesion test sample. Between the vulcanized rubber using sulfur as a vulcanizing agent and the vulcanized rubber using an organic peroxide as a vulcanizing agent (intermediate rubber layer), the above sample was subjected to the same method as the JISK6301 peel test.
Peel at a speed of 50 mm/min, and check the peel strength at room temperature and
Measurement was performed under heat (120°C). Example 1 First, an EPDM rubber compound (A-1) using sulfur as a vulcanizing agent and an EPM rubber compound (B-1) using an organic peroxide as a vulcanizing agent shown in Table 1 were prepared according to the above preparation method.
-1) and organic peroxides were used as vulcanizing agents.
EPDM rubber compounds (C-1) were prepared, and the former two were laminated and bonded together with the latter (C-1) as an intermediate layer. The adhesive strength was measured according to the above test procedure and was as shown in Table 2 below.

【table】

[Table] From the results of the above adhesion test, as in Example 1 of the present invention, when using the C-1 blend (organic peroxide is used as the vulcanizing agent) in the intermediate layer, when there is no intermediate layer ( Compared to Comparative Example 1), it can be seen that the level of adhesive strength is high both at room temperature (120°C) and the peeling state is excellent. Example 2 A-1 formulation and B-1 formulation in Table 1 above,
Adhesion tests were carried out in the same manner as in Example 1 using the formulations shown in Table 3 as intermediate layers for the adhesive material. The results are shown in Table 4.

【table】

[Table] From the table above, the polymers of the rubber compound for the intermediate layer are
Adhesion when blended with EPDM and chloroprene rubber and SBR is improved by containing at least 60% EPDM as a polymer component, compared to EPDM rubber formulations using sulfur as a vulcanizing agent and organic peroxides as a vulcanizing agent. It is understood that it is possible to bond with the EPM rubber compound used as the adhesive. Example 3 An adhesion test was carried out in the same manner as in Examples 1 and 2 using B-1 formulations and C-1 formulations in Table 1 and the formulations shown in Table 5. The results were as shown in Table 6.

【table】

【table】

【table】

[Table] From the above table, the proportion of EPDM in the polymer of compounded rubber using sulfur as a vulcanizing agent is at least 60%.
If it does not contain, the adhesive force will be low when peeled off at room temperature, and the peeled state will also be peeled off at the interface. On the other hand, when peeling under heat (120°C), unless the proportion of EPDM in the polymer is 70% or more, the adhesive strength will be low and the peeling state will be interfacial peeling. Example 4 An adhesion test was conducted in the same manner as in Examples 1, 2, and 3 using the A-1 formulation and C-1 formulation in Table 1 and the formulations shown in Table 7. The results are shown in the 8th section.
Shown in the table.

【table】

[Table] From the table above, regarding the polymer components of rubber compounds using organic peroxides as vulcanizing agents, EPM and EPDM
Even if the blending ratio of EPDM increases, adhesion is possible, but the heat resistance is inferior. Also, similarly
Regarding the blend of EPM, CR, and SBR, CR,
Even if the proportion of SBR increases, adhesion is possible, but the heat resistance is inferior. (Effects of the invention) As explained above, the rubber laminate according to the present invention uses sulfur as a vulcanizing agent, which was difficult to do in the past.
An EPDM rubber compound that uses an organic peroxide as a vulcanizing agent and an EPDM rubber compound, or an EPDM rubber compound that uses an organic oxide as a vulcanizing agent as an adhesive material to bond the EPM rubber compound at the same time as vulcanization. As is clear from the examples, it has been confirmed that this product has an intermediate layer of It is now possible to use this technology for practical purposes, and is expected to have practical effects in the future.

Claims (1)

[Claims] 1 Rubber compound containing at least 60 parts by weight of ethylene-propylene-nonconjugated diene terpolymer in the polymer component and using sulfur as a vulcanizing agent (A)
and a polymer selected from ethylene-propylene non-conjugated diene terpolymer or ethylene-propylene copolymer in the polymer component.
Rubber compound (B) containing 60 parts by weight and using an organic peroxide as a vulcanizing agent, and vulcanization containing at least 60 parts by weight of an ethylene-propylene-nonconjugated diene terpolymer in the polymer component as an adhesive material. A rubber laminate characterized in that it is formed by laminating and adhering a rubber compound (C) using an organic peroxide as an agent.