JP5563857B2 - Vulcanized adhesive laminate of fluororubber and synthetic rubber - Google Patents

Description

  The present invention relates to a vulcanized adhesive laminate of fluororubber and synthetic rubber other than fluororubber such as NBR, hydrogenated NBR, NBR / PVC blend, NBR / EPDM blend, CSM, ECO, ACM, AEM or CR.

Fluororubber is attracting attention as a material for fuel hoses because it is excellent in heat resistance, oil resistance, ozone resistance, chemical resistance, and the like, but there is a problem that fluorine rubber is expensive.
Therefore, in order to maintain oil resistance and to maintain the flexibility of the hose, a two-layer structure in which fluororubber is the innermost layer and synthetic rubber is disposed on the outer side is considered optimal. Among them, the two-layer structure with NBR (acrylonitrile-butadiene rubber), which is relatively excellent in oil resistance and inexpensive, is said to be optimal, but generally direct vulcanization adhesion between fluoro rubber and synthetic rubber is difficult. there were.

For this reason, as a fuel hose, for example, in Patent Document 1, epichlorohydrin rubber (ECO) is selected as a partner to be bonded to fluoro rubber, and a rubber composition in which DBU, DBN, or the like is blended is adopted. Has been proposed. However, even if a scorch countermeasure is added by adding a scorch inhibitor or the like, as long as DBU or DBN is still used, there is a tendency to scorch during kneading, storage and molding of a synthetic rubber compound. . For this reason, it is necessary not to use DBU, DBN or the like in order to fundamentally take countermeasures for scorching, but vulcanization adhesion becomes difficult without using DBU, DBN or the like.
Separately, Patent Document 2 proposes bonding a metal and rubber such as EPDM, but Patent Document 2 does not describe bonding fluororubber and NBR.
In Patent Document 3, it is a direct vulcanization adhesion method between fluororubber and NBR, but a triazine compound or an alkaline earth oxide is added to the fluororubber layer, but not to the synthetic rubber layer. is there. Therefore, the adhesive peel strength is weak, and there is a problem that a stronger adhesive force is required in actual use.

  Furthermore, Patent Document 4 describes a laminate obtained by vulcanizing and bonding a fluororubber layer and an NBR layer, and the NBR layer contains a phosphonium salt and a known sulfur-containing vulcanizing agent. However, since Patent Document 4 does not contain a triazine compound, silica, or magnesium oxide, it has not been possible to exert sufficient adhesive strength.

  In such vulcanization adhesion described in Patent Documents 1, 2, 3, and 4, the purpose of vulcanization adhesion between the fluororubber and the synthetic rubber with a strong adhesion force was not achieved.

JP 2006-306053 A JP 2006-328335 A Japanese Patent Laid-Open No. 55-159975 JP 2009-56632 A

  Provided is a vulcanized adhesive laminate in which a fluororubber and a specific synthetic rubber are vulcanized and bonded to each other with a strong adhesive force.

A fluororubber layer and a layer made of synthetic rubber other than fluororubber selected from (A) and a blend of two or more selected from (B) are vulcanized and vulcanized. A vulcanized adhesive laminate in which a layer made of synthetic rubber other than fluororubber before bonding contains the following (1) to (5) and a flexible hose for a vehicle made of this laminate.
(1) Triazine compound (2) Organic phosphonium salt (3) Sulfur-containing organic compound (4) Silica (5) Magnesium oxide (B) NBR, hydrogenated NBR, NBR / PVC blend, NBR / EPDM blend, CSM, ECO , ACM, AEM, or CR

  By the method of the present invention, a laminate obtained by firmly vulcanizing and bonding various fluororubbers and a specific synthetic rubber was obtained. The use of such a laminate includes a fuel hose that fully utilizes the properties of fluororubber.

A hose consisting of two layers using fluorine rubber for the inner layer and synthetic rubber for the outer layer. A hose consisting of five layers using fluorine rubber for the innermost layer, synthetic rubber for the outer layer, a first fiber reinforcing layer as a reinforcing layer, an intermediate rubber layer, a second fiber reinforcing layer as a reinforcing layer, and an outer rubber layer .

  The present invention is described in detail below. The present invention relates to a vulcanized adhesive laminate comprising a fluororubber layer and a specific synthetic rubber layer, wherein the specific synthetic rubber layer contains a triazine compound, an organic phosphonium salt, a sulfur-containing organic compound, silica, and magnesium oxide. To do.

[Fluoro rubber layer]
The fluororubber to be used is not particularly limited, and may be a copolymer of a fluorine-containing monomer or a copolymer of a fluorine-containing monomer and a hydrocarbon monomer.
Fluorine-containing monomers include: vinylidene fluoride, trifluoroethylene, trifluorochloroethylene, tetrafluoroethylene, fluoroethylene such as vinyl fluoride, fluoropropylene such as hexafluoropropene and pentafluoropropene, perfluoro (methyl vinyl ether), perfluoro And perfluoro (alkyl vinyl ether) such as (propyl vinyl ether). A fluorine monomer may be used individually by 1 type, and may use 2 or more types together.

  Examples of the hydrocarbon monomer include olefins such as ethylene and propylene, vinyl ethers such as methyl vinyl ether and ethyl vinyl ether, vinyl esters such as vinyl acetate, and acrylic acid esters such as methyl acrylate. A hydrocarbon monomer may be used individually by 1 type, and may use 2 or more types together.

  In the present invention, as the fluororubber, a copolymer obtained by copolymerizing a small amount of other monomers serving as a vulcanization site in addition to the fluorine monomer and the hydrocarbon monomer may be used. As other monomers, monomers containing iodine atoms such as 2-iodoperfluoropropene and 4-iodofluorobutene-1, bromotrifluoroethylene, 4-bromo-3,3,4,4-tetrafluorobutene-1 And a monomer containing a bromine atom.

  Specific examples of the fluororubber in the present invention are preferably vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer, tetrafluoroethylene-propylene copolymer, tetrafluoro And ethylene-vinylidene fluoride-propylene copolymer. A fluororubber may be used individually by 1 type, and may use 2 or more types together.

[Synthetic rubber layer]
The synthetic rubber in the present invention is composed of one or a mixture of two or more selected from NBR, hydrogenated NBR, NBR / PVC blend, NBR / EPDM blend, CSM, ECO, ACM, AEM or CR. Although it is a synthetic rubber other than fluorine rubber, NBR is desirable in consideration of use in fuel-resistant applications and price, and NBR with an AN amount (bonded acrylonitrile content) of 25 to 50% by weight is preferred. When the amount of AN is small, gasoline resistance and oil resistance are lowered. When the amount of AN is large, oil resistance is improved, but low temperature characteristics tend to be lowered.
A blend of acrylic rubber or polyvinyl chloride provides an excellent balance of gasoline resistance, oil resistance, and oil resistance. If EPDM is blended, ozone resistance can be improved.

  In the present invention, other polymers can be blended with the synthetic rubber according to the purpose. Other polymers include natural rubber, isoprene rubbers such as isoprene rubber, conjugated diene rubbers such as butadiene rubber and styrene-butadiene rubber, and non-diene rubbers such as butyl rubber (IIR).

[Triazine compound]
Triazine compounds include di- or trithiol-s-triazine. Specific examples include 1,3,5-triazine-2,4,6-trithiol, 6-anilino-1,3,5-triazine-2,4-dithiol, 6-dibutylamino-1,3,5- Examples include triazine-2,4-dithiol, 6-diallylamino-1,3,5-triazine-2,4-dithiol, 6-octylamino-1,3,5-triazine-2,4-dithiol. Among these, 1,3,5-triazine-2,4,6-trithiol and 6-dibutylamino-1,3,5-triazine-2,4-dithiol are preferable.
The triazine compound is added to 0.5 to 5 parts by weight, preferably 1.0 to 4 parts by weight, with respect to 100 parts by weight of the synthetic rubber. When the addition amount is less than 0.5 parts by weight, the vulcanization adhesiveness is insufficient, and when it exceeds 5 parts by weight, there is a concern that the rubber is scorched.

[Organic phosphonium salt]
As the organic phosphonium salt, a quaternary phosphonium salt containing an alkyl group having 1 to 20 carbon atoms or a quaternary phosphonium salt containing an aromatic substituent can be used. Specifically, tetrabutylphosphonium salt, tetraoctylphosphonium salt, methyltrioctylphosphonium salt, butyltrioctylphosphonium salt, phenyltributylphosphonium salt, benzyltributylphosphonium salt, benzyltricyclohexylphosphonium salt, benzyltrioctylphosphonium salt, butyl Examples thereof include triphenylphosphonium salt, octyltriphenylphosphonium salt, benzyltriphenylphosphonium salt, and tetraphenylphosphonium salt. Of these, tetrabutylphosphonium salts are preferred.
The amount of the organic phosphonium salt added is preferably 0.3 to 3 parts by weight and more preferably 0.5 to 2.5 parts by weight with respect to 100 parts by weight of the synthetic rubber. If the addition amount is less than 0.3 parts by weight, the vulcanization adhesion is insufficient, and if it exceeds 3 parts by weight, the rubber may be scorched, and the compounding chemical is expensive, so the rubber material unit price Becomes higher.

[Sulfur-containing organic compounds]
As the sulfur-containing organic compound, a compound that decomposes at a vulcanization temperature to release active sulfur and functions as a vulcanizing agent can be used. Specific examples include 4,4′-dithiodimorpholine, 2- (4-morpholinodithio) benzothiazole, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, tetrapentathiuram disulfide and the like. Of these, 4,4′-dithiodimorpholine is preferred. In addition, the sulfur-containing triazine compound may not be included in the sulfur-containing organic compound, but may be.
The sulfur-containing organic compound is preferably 0.5 to 5 parts by weight and more preferably 1 to 4 parts by weight with respect to 100 parts by weight of the synthetic rubber. If the addition amount is less than 0.5 parts by weight, the vulcanization adhesion is insufficient, and if it exceeds 5 parts by weight, there is a concern that the rubber will be scorched, and the compounding chemical is expensive, so the unit price of the rubber material Get higher.

[silica]
Silica particles are silicic acid (SiO ₂ ) fillers, and acidic silica, neutral silica, and basic silica can be arbitrarily used as the silicic acid filler.
The amount of silica added is preferably 5 to 35 parts by weight and more preferably 10 to 30 parts by weight with respect to 100 parts by weight of the synthetic rubber. When the addition amount is less than 5 parts by weight, the vulcanization adhesiveness is insufficient, and when it exceeds 35 parts by weight, the low temperature characteristics are deteriorated.

[Magnesium oxide]
Magnesium oxide particles function as an acid acceptor for hydrogen fluoride generated when dehydrofluorination is performed from the fluororubber on the surface in contact with the synthetic rubber, and the interlayer adhesion becomes higher.
Magnesium oxide is preferably 3 to 20 parts by weight and more preferably 5 to 15 parts by weight with respect to 100 parts by weight of the synthetic rubber. When the addition amount is less than 3 parts by weight, the vulcanization adhesion is insufficient, and when it exceeds 20 parts by weight, the rubber properties tend to be deteriorated.

In the present invention, all of the above five kinds of compounding agents are indispensable for the synthetic rubber layer. If even one kind of compounding agent is lacking, the vulcanized adhesive laminate of the fluororubber and the synthetic rubber of the present invention cannot be obtained.
For the synthetic rubber layer, in addition to the above, known compounding agents added to ordinary rubber compositions such as carbon black, fillers, softeners, plasticizers, anti-aging agents, stabilizers, and processing aids It is possible to add appropriately.

[Method for producing vulcanized adhesive laminate]
As a method for producing the vulcanized adhesive laminate of the present invention, a layer made of fluororubber and synthetic rubber before vulcanization is co-extruded and then crosslinked, or a layer made of one rubber is formed, and then the other layer is made. Examples of the method include cross-linking after forming a rubber layer, and a method of cross-linking one rubber layer, laminating the other rubber layer, and then cross-linking the other layer.
When the vulcanized adhesive laminate of the present invention is a hose, in addition to the above method, a method of covering the mandrel with an unvulcanized laminate and vulcanizing it can also be employed.

[Use of vulcanized adhesive laminate]
The vulcanized adhesive laminate of the present invention includes a fuel hose, a hose for transporting alcohol, fats and the like, a hose for transporting air containing oil droplets, mineral oil, LP gas, natural gas, etc. Hoses for transporting hydrocarbon-containing liquids or gases, containers for storing these fluids, and industrial belts, cushioning materials, anti-vibration materials, sheets, boots, etc. in contact with these fluids It can be used for various applications such as parts, equipment parts, building parts, and equipment parts.
For example, a hose for transporting fuel, alcohol, LP gas, etc., a fluororubber layer is formed on the inner surface of the hose in contact with the transported object, and a layer made of synthetic rubber is formed on the outer surface of the hose. Similarly, in the laminated body other than the hose, a fluorine rubber layer is formed on the surface in contact with the fuel, alcohol, LP gas, etc., and a layer made of synthetic rubber is formed on the other layers.
For example, when the fluid to be transported is low pressure, as shown in FIG. 1, a two-layer hose using a fluoro rubber layer as the inner layer and a synthetic rubber layer as the outer layer is used. As shown in FIG. 2, a fluororubber layer is used as an inner layer, a synthetic rubber layer is provided immediately outside the inner layer, and a first fiber reinforcing layer, an intermediate rubber layer, a second fiber reinforcing layer, and A five-layer hose provided with an outer rubber layer can be used. Of course, hoses having other layer configurations can be used depending on the application.
Next, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples.

Examples and Comparative Examples

Each component was mix | blended with the quantity shown in Table 1-Table 3, and it knead | mixed using the kneader, and obtained the NBR composition. An NBR sheet having a thickness of 2 mm was produced from this NBR composition using an 8-inch roll.
Similarly, a fluororubber sheet having a thickness of 2 mm was also prepared.
The hardness of these sheets was measured according to JIS K6253, and the tensile test was performed using a No. 3 dumbbell according to JIS K6251.

  The unvulcanized NBR sheet having a thickness of 2.0 mm and the unvulcanized fluororubber sheet having a thickness of 2.0 mm obtained above were pressed as pretreatments at 100 ° C. for 3 minutes, and this was steamed at 160 ° C. for 30 minutes. A fluororubber-NBR laminate was prepared by vulcanization.

The peel test of the adhesion test piece was performed according to JIS K6256-1. This test piece was attached to a tensile test, pulled at a speed of 50 mm per minute, and the adhesiveness was evaluated based on the peeled state at the adhesive interface between NBR and fluororubber.
×: Not adhered at all (adhesion failure), tensile strength: 5 N / cm or less: NG
Δ: When interfacial peeling occurs: NG
○: Rubber part is broken (adhesiveness is good), tensile strength: 25 N / cm or more: OK

NBR: Nanker 1053 Nanker Chemical
Carbon black: Asahi Carbon Asahi # 60G
Silica: Hisil 233 from PPG industries
Magnesium oxide: Kyowa Mug 150 manufactured by Kyowa Chemical Industry
Triazine compounds: Actor BSH manufactured by Kawaguchi Chemical Industry
Organic phosphonium salt: Nippon Kagaku Kogyo Zeonet PB
Organic sulfur-containing compounds: Balnock R, manufactured by Ouchi Chemical Industry
Fluoro rubber: Daiel G558 made by Daikin Industries

  According to the results of the above Examples and Comparative Examples, the vulcanized adhesive laminate of the present invention is excellent in adhesion between both layers. For example, as in Comparative Examples 1 to 5, (1) to (2 ) And (4) to (5) are not used, or when only one of these components is used, the two layers do not adhere to each other at all, as in Comparative Examples 6 to 10. If even one of the components (1) to (5) in the present invention is missing, interfacial delamination occurs between the two layers.

  According to the results of Examples and Comparative Examples as described above, all of the above five kinds of compounding agents are indispensable for the synthetic rubber layer. If one kind of compounding agent is left out, the fluororubber layer and the synthetic rubber of the present invention are used. It can be seen that a vulcanized adhesive laminate in which the layers are sufficiently bonded cannot be obtained, and the present invention includes all the components (1) to (5) in the synthetic rubber layer that is vulcanized and bonded to the fluororubber layer. It is clear that a remarkable effect is exhibited for the first time, and that the effects obtained by using each of the components (1) to (5) alone are not merely an effect.

  As a result of the above-mentioned example, a vulcanized bonded laminate is obtained by vulcanizing and bonding a fluororubber layer and a synthetic rubber layer having a specific composition, with a stronger adhesive strength than a conventional laminate. I was able to.

Claims (4)

Adhesive strength of 25 N / cm or more of a fluororubber layer (A) not containing silica and a synthetic rubber layer other than fluororubber selected from the following (B) and blended with one or more types We are bonded by vulcanization so that, vulcanization layer of synthetic rubber other than fluorine rubber before wearing the following (1) to (5) containing vulcanization adhesion laminates.
(1) Triazine compound (2) Organic phosphonium salt (3) Sulfur-containing organic compound (4) Silica (5) Magnesium oxide (B) NBR, hydrogenated NBR, NBR / PVC blend, NBR / EPDM blend, CSM, ECO , ACM, AEM, or CR The vulcanized adhesive laminate according to claim 1, wherein the content of (1) to (5) contained in the synthetic rubber other than the fluororubber is the following parts by weight with respect to 100 parts by weight of the rubber.
(1) Triazine compound 0.5-5 parts by weight (2) Organic phosphonium salt 0.3-3 parts by weight (3) Sulfur-containing organic compound 0.5-5 parts by weight (4) Silica 5-35 parts by weight ( 5) 3-20 parts by weight of magnesium oxide   The flexible hose for a vehicle, comprising the vulcanized adhesive laminate according to claim 1 or 2, wherein the hose cross section is composed of at least a plurality of layers, wherein the inner rubber layer is the fluororubber, and the outer rubber layer is disposed outside the inner rubber layer. A flexible hose for a vehicle, wherein a synthetic rubber layer other than fluoro rubber is provided.   The vehicle flexible hose includes the inner rubber layer and a synthetic rubber layer other than the fluoro rubber provided outside the inner rubber layer, and at least one outer layer of the synthetic rubber layer other than the fluoro rubber. 4. The vehicle flexible hose according to claim 3, comprising a fiber reinforcing layer and an outer rubber layer provided outside the fiber reinforcing layer.

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