Rubber composition for rubber layer of laminated hose, laminated hose, and laminated hose for motor vehicle

Abstract

Provided is a laminated hose having excellent interlayer adhesion and excellent sealing properties. A rubber composition for an inner rubber layer (1) and / or an outer rubber layer (3) contains the following components (A)-(D). (A) An ethylene-propylene-diene terpolymer. (B) A tackifier containing a constituent unit derived from an aromatic monomer. And (C) a bismaleimide compound. And (D) a vulcanizing agent.

Description

Technical Field

[0001] The present invention relates to a laminated hose including a laminated structure having a rubber layer, and specifically, to a radiator hose for connecting an engine and a radiator in a motor vehicle or the like, a heater hose for connecting an engine and a heater core, and other engine cooling system hoses, a refrigerant transport hose for a cooler, a methanol fuel hose, a hydrogen fuel hose, and other hoses for a fuel cell vehicle, a gasoline fuel hose, and other laminated hoses for a motor vehicle, which include a laminated structure formed by laminating a rubber layer and a resin layer such as a reinforcing layer. Background Art

[0002] Conventionally, as a laminated hose for a vehicle such as a motor vehicle, for example, a radiator hose for connecting an engine and a radiator, a heater hose for connecting an engine and a heater core, and other engine cooling system hoses, a hose having a three-layer structure (inner rubber layer / reinforcing wire layer / outer rubber layer) formed by forming a reinforcing wire layer or the like on the outer peripheral surface of an inner rubber layer and then forming an outer rubber layer on its outer peripheral surface is used.

[0003] A hose having such a structure is manufactured as follows: For example, an inner rubber layer is formed by extrusion molding of a material for the inner rubber layer, and after applying an adhesive to the outer peripheral surface of the inner rubber layer, a reinforcing wire such as a nylon wire (polyamide wire) or an aramid wire is woven on its outer peripheral surface to form a reinforcing wire layer, and an outer rubber layer is formed by extrusion molding of a material for the outer rubber layer on the outer peripheral surface of the reinforcing wire layer, and they are crosslinked (for example, refer to Patent Document 1, etc.), or, for example, an inner rubber layer is formed by extrusion molding of a material for the inner rubber layer, a reinforcing wire such as a nylon wire (polyamide wire) or an aramid wire is woven on the outer peripheral surface of the inner rubber layer to form a reinforcing wire layer, and then an adhesive is applied to the outer peripheral surface of the reinforcing wire layer, an outer rubber layer is formed by extrusion molding of a material for the outer rubber layer, and they are crosslinked. In addition, as the reinforcing wire, an impregnated wire after being impregnated with an adhesive is sometimes used.

[0004] However, according to the research of the present inventors, if the above-described adhesive coating treatment and impregnation treatment are performed, it is difficult to ensure good interlayer adhesiveness in the laminated hose uniformly due to coating unevenness and impregnation unevenness. For example, there is a problem that a high degree of sealing required for a hose for a motor vehicle or the like cannot be ensured.

[0005] In addition, an adhesive is usually a solution in which an adhesive component is dissolved in a solvent belonging to Class 4 of dangerous goods such as toluene, xylene, and methyl ethyl ketone, so volatile organic compounds (VOCs) are generated in the manufacturing process, and there is a problem of causing deterioration of the global environment.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: International Publication No. WO2012 / 133385 SUMMARY OF THE INVENTION

[0009] Problems to be Solved by the Invention

[0010] The present invention has been completed in view of the above circumstances, and provides a laminated hose having excellent interlayer adhesiveness and excellent sealing performance even without using an adhesive.

[0011] Means for Solving the Problems

[0012] The inventors of the present invention repeatedly conducted in-depth studies to solve the above problems. In the process of this research, it was found that if a rubber composition containing (A) an ethylene-propylene-diene terpolymer, (B) a tackifier containing a structural unit derived from an aromatic monomer, (C) a bismaleimide compound, and (D) a vulcanizing agent is used as the rubber composition of the rubber layer constituting the laminated hose, the interlayer adhesiveness between the rubber layer and the adherend layer becomes good, and as a result, a laminated hose having excellent sealing performance can be provided.

[0013] That is, in the process of researching laminated hoses with excellent interlayer adhesiveness, the inventors investigated the case of blending various tackifiers. However, when various tackifiers were blended only in the rubber composition for the rubber layer, it was difficult to sufficiently improve the interlayer adhesiveness. While investigating tackifiers, the inventors further repeatedly conducted in-depth studies focusing on the affinity between the rubber component and other compounding components, and the interaction between the compounding components, etc. As a result, it was found that by using an ethylene-propylene-diene terpolymer in various rubbers and using a specific tackifier and a bismaleimide compound in combination in various compounding agents, the interlayer adhesiveness in the laminated hose can be improved, and thus the present invention was completed.

[0014] That is, the present invention has the following gist [1] to

[12] . [1]

[0016] A rubber composition for a rubber layer of a laminated hose, wherein the rubber composition for the rubber layer contains the following components (A) to (D).

[0017] (A) An ethylene-propylene-diene terpolymer.

[0018] (B) A tackifier containing a structural unit derived from an aromatic monomer.

[0019] (C) A bismaleimide compound.

[0020] (D) A vulcanizing agent. [2]

[0022] The rubber composition for a rubber layer according to [1], wherein the component (B) is a tackifier containing 20% by mass or more of structural units derived from aromatic monomers. [3]

[0024] The rubber composition for a rubber layer according to [1] or [2], wherein the total content (B + C) of the component (B) and the component (C) is 2.5 to 20 parts by mass with respect to 100 parts by mass of the component (A). [4]

[0026] The rubber composition for a rubber layer according to any one of [1] to [3], wherein the mass ratio (B / C) of the component (B) to the component (C) is 0.25 to 1.5. [5]

[0028] The rubber composition for a rubber layer according to any one of [1] to [4], wherein the component (C) is an aromatic bismaleimide compound. [6]

[0030] The rubber composition for a rubber layer according to any one of [1] to [5], wherein the component (B) is a tackifier further containing structural units derived from aliphatic monomers. [7]

[0032] The rubber composition for a rubber layer according to any one of [1] to [6], wherein the laminated hose is a laminated hose including a laminated structure in which a rubber layer and a resin layer are laminated. [8]

[0034] The rubber composition for a rubber layer according to [7], wherein the resin layer is a reinforcing wire layer, and the reinforcing wire layer is composed of reinforcing wires including at least one selected from the group consisting of polyamide wires, polyethylene terephthalate wires, and polyvinyl alcohol wires. [9]

[0036] A laminated hose, wherein the laminated hose includes a laminated structure in which a rubber layer composed of a vulcanizate of the rubber composition for a rubber layer according to any one of [1] to [6] and a resin layer are laminated.

[10]

[0038] The laminated hose according to [9], wherein the resin layer is a reinforcing wire layer.

[11]

[0040] A laminated hose for a motor vehicle, wherein the laminated hose for a motor vehicle comprises a first rubber layer formed of a sulfide of a rubber composition for a rubber layer according to any one of [1] to [6], a reinforcing wire layer, and a second rubber layer formed of a sulfide of a rubber composition for a rubber layer containing the component (A) and the component (D) laminated in this order.

[0041] That is, a laminated hose for a motor vehicle, wherein the laminated hose for a motor vehicle comprises a laminated structure in which a first rubber layer formed of a sulfide of a rubber composition for a rubber layer containing the following components (A) to (D) and a second rubber layer formed of a sulfide of a rubber composition for a rubber layer containing the following component (A) and the following component (D) are laminated in this order.

[0042] (A) Ethylene-propylene-diene terpolymer.

[0043] (B) A tackifier containing a structural unit derived from an aromatic monomer.

[0044] (C) A bismaleimide compound.

[0045] (D) A vulcanizing agent.

[12]

[0047] The laminated hose for a motor vehicle according to

[11] , wherein the second rubber layer is a rubber layer formed of a sulfide of a rubber composition for a rubber layer further containing the component (B) and / or the component (C).

[0048] Advantages of the Invention

[0049] According to the present invention, it is possible to provide a laminated hose having excellent interlayer adhesiveness and excellent sealing performance even without particularly using an adhesive.

[0050] In addition, according to an embodiment of the present invention, volatile organic compounds (VOCs) can be reduced, contributing to the preservation of the global environment. Further, according to an embodiment of the present invention, processes such as an adhesive coating process in the manufacturing process of a multilayer hose can be reduced, which is very advantageous in terms of manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a perspective view showing an example of the hose of the present invention.

[0052] Figure 2 It is a diagram for explaining the test method shown in this specification. DETAILED DESCRIPTION OF THE INVENTION

[0053] Next, embodiments of the present invention will be described in detail.

[0054] In addition, in this specification, the "main component" refers to a component that has a relatively large influence on the properties of the material. Without special specification, the content of this component is 50% by mass or more of the entire material, preferably 60 - 100% by mass, 70 - 100% by mass, 80 - 100% by mass, 90 - 100% by mass, etc.

[0055] In addition, in this specification, "X and / or Y (where X and Y are arbitrary components)" means at least one of X and Y, referring to the three cases of only X, only Y, and X and Y.

[0056] <<Rubber composition for rubber layer>>

[0057] The rubber composition for a rubber layer according to one embodiment of the present invention (hereinafter sometimes referred to as "this rubber composition") is characterized by containing components (A) to (D).

[0058] (A) Ethylene - propylene - diene terpolymer.

[0059] (B) A tackifier containing structural units derived from aromatic monomers.

[0060] (C) A bismaleimide compound.

[0061] (D) A vulcanizing agent.

[0062] The reason for obtaining high interlayer adhesiveness with a laminated hose using the entire rubber composition containing components (A) to (D) is not clear yet, but it is speculated that by using a tackifier (B) containing structural units derived from aromatic monomers and a bismaleimide compound (C) in combination, the affinity for the ethylene - propylene - diene terpolymer (A) is reduced, promoting transfer to the surface of the rubber layer. As a result, it contributes to the formation of a diffusion layer, strengthening the integration between layers and increasing the interlayer adhesive force.

[0063] Specifically, for example, in a laminated hose having a laminated structure in which a rubber layer using this rubber composition and a reinforcing wire layer are laminated, components (C) and (B) are induced, mixed through interaction, and the transfer to the interface is promoted. Furthermore, the transfer of component (D) to the interface is also synergistic with this, promoting impregnation into the reinforcing wire layer. As a result, they form a strong crosslinked structure, strengthening the integration between layers and increasing the interlayer adhesive force.

[0064] By using this rubber composition, it is possible to provide a laminated hose with high interlayer adhesiveness and excellent sealing performance even without particularly using an adhesive. Therefore, for example, volatile organic compounds (VOCs) can be reduced, contributing to the preservation of the global environment. Furthermore, the adhesive coating process and the impregnation treatment process in the manufacturing process of the multi-layer hose can be reduced, thus reducing the manufacturing cost.

[0065] In addition, during the research process, the present inventors also found that by using this rubber composition, it is possible to highly balance the interlayer adhesiveness and the compression set in the laminated hose. That is, during the research on improving the interlayer adhesiveness in the laminated hose, an attempt was made to highly balance the interlayer adhesiveness and the compression set, which is one of the important properties of the laminated hose. However, it was difficult to sufficiently improve both the interlayer adhesiveness and the compression set. While exploring tackifiers, the present inventors focused on the affinity between the rubber component and other compounding ingredients, as well as the interaction between the compounding ingredients, and repeatedly conducted further in-depth research. As a result, it was also found that by using this rubber composition, it is possible to highly balance the interlayer adhesiveness and the compression set in the laminated hose. This rubber composition is very useful in terms of balancing the interlayer adhesiveness and the compression set.

[0066] Hereinafter, the embodiments of the present invention will be described in more detail.

[0067] [(A) Ethylene-Propylene-Diene Terpolymer (EPDM)]

[0068] The component (A) for this rubber composition is obtained by copolymerizing ethylene-propylene rubber (EPM), which is a copolymer of ethylene and propylene, with a diene monomer as the third component (hereinafter, sometimes simply referred to as "EPDM"). The component (A) can be used alone or in combination of two or more.

[0069] The diene monomer (third component) contained in the component (A) is not particularly limited, and a diene monomer having 5 to 20 carbon atoms is preferred. Specifically, 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 2,5-dimethyl-1,5-hexadiene, 1,4-octadiene, 1,4-cyclohexadiene, cyclooctadiene, dicyclopentadiene (DCP), 5-ethylidene-2-norbornene (ENB), 5-butylidene-2-norbornene, etc. can be cited. These can be used alone or in combination of two or more. Among them, dicyclopentadiene (DCP) and 5-ethylidene-2-norbornene (ENB) are preferred.

[0070] The ethylene content of the component (A) is not particularly limited, and from the viewpoint of significantly exerting the effects of the present invention, it is preferably 48 to 70% by mass, more preferably 50 to 60% by mass.

[0071] In addition, the propylene content of component (A) is not particularly limited. From the viewpoint of significantly exerting the effects of the present invention, it is preferably 22 to 46% by mass, more preferably 30 to 44% by mass.

[0072] In addition, the diolefin monomer content of component (A) is not particularly limited, and is preferably 3 to 11% by mass, more preferably 3.5 to 6% by mass.

[0073] In addition, the iodine value of component (A) is not particularly limited. From the viewpoint of significantly exerting the effects of the present invention, it is preferably 6 to 30, more preferably 10 to 24.

[0074] The content of component (A) is not particularly limited, and is usually 20% by mass or more, preferably 25% by mass or more, more preferably 28 to 60% by mass relative to the present rubber composition (100% by mass).

[0075] [(B) Tackifier]

[0076] In the present rubber composition, among various tackifiers, it is particularly important to use a tackifier containing a structural unit derived from an aromatic monomer. That is, as component (B), for example, addition polymers of aromatic monomers having any one of vinyl carbon-carbon double bonds such as indene, vinyltoluene, styrene, α-methylstyrene, and isopropenyl ester can be cited. Component (B) can be a homopolymer of the above monomers, a copolymer composed of two or more of the above monomers appropriately combined, etc. In addition, it can also be a component copolymerized with components other than aromatic monomers, such as any one of aliphatic monomers such as isoprene, 1,3-pentadiene, and 2-methyl-2-butene.

[0077] In addition, component (B) can also be a component modified with a phenolic compound, maleic anhydride, acrylic acid, methacrylic acid, etc. Component (B) can be used alone or in combination of two or more.

[0078] In component (B), from the viewpoint of significantly exerting the effects of the present invention, a hydrocarbon tackifying resin containing a structural unit derived from an aromatic monomer is preferably included. As the above hydrocarbon tackifying resin, for example, aromatic (C9 series) petroleum resins, aliphatic / aromatic copolymer (C5 / C9 series) petroleum resins, their hydrogenated products, their various modified products (for example, maleic anhydride modified products), coumarone resins, etc. can be cited.

[0079] As the aromatic (C9 series) petroleum resin, there is no particular limitation. For example, an aromatic (C9 series) petroleum resin preferably composed of one or more components selected from the group consisting of constituent units derived from indene, styrene, and vinyltoluene is more preferably an aromatic (C9 series) petroleum resin composed of two or three components selected from the group consisting of constituent units derived from indene, styrene, and vinyltoluene. In addition, as the aliphatic / aromatic copolymer (C5 / C9 series) petroleum resin, there is no particular limitation. For example, an aliphatic / aromatic copolymer (C5 / C9 series) petroleum resin preferably composed of one or more components selected from the group consisting of constituent units derived from indene, styrene, and vinyltoluene and constituent units of isoprene and / or piperylene is preferred. In addition, as the coumarone resin, there is no particular limitation. For example, a coumarone resin preferably containing constituent units derived from coumarone and further composed of one or more components selected from the group consisting of constituent units derived from indene, styrene, and vinyltoluene is preferred.

[0080] In addition, as the component (B), examples include alkylphenol resins, terpene-phenol resins, rosin-phenol resins, styrene resins, etc.

[0081] The alkylphenol resin is not particularly limited as long as it is an alkylphenol resin used as a tackifier, and it is a resin obtained from the resin of alkylphenol and formaldehyde. For example, various condensates of alkylphenol and formaldehyde such as o-cresol, m-cresol, p-cresol, ethylphenol, isopropylphenol, xylenol, 3,5-xylenol, butylphenol, p-tert-butylphenol, nonylphenol, etc. can be cited.

[0082] The terpene-phenol resin is not particularly limited as long as it is a terpene-phenol resin used as a tackifier, and both copolymers of terpenes and phenolic compounds (terpene-phenol copolymer resins) and resins obtained by phenol-modifying homopolymers or copolymers of terpenes (phenol-modified terpene resins) can be cited. As the terpenes constituting the terpene-phenol resin, for example, monoterpenes such as α-pinene, β-pinene, limonene (including d-form, l-form, and d / l-form (dipentene)) can be cited.

[0083] The rosin-phenol resin is not particularly limited as long as it is a rosin-phenol resin used as a tackifier, and rosin-phenol resins obtained by subjecting natural rosin, rosin derivatives, etc. to an addition reaction with phenols, so-called rosin-modified phenolic resins obtained by reacting novolac-type phenolic resins with rosin-based resins, etc. can be cited. The rosin-phenol resin can be a metal salt of the rosin-phenol resin or an esterified product obtained by reacting a rosin-based resin with a polyol.

[0084] As the styrene resin, there is no particular limitation as long as it is a styrene resin used as a tackifier. Examples include styrene resins mainly composed of homopolymers of styrene, styrene resins mainly composed of homopolymers of α-methylstyrene, styrene resins mainly composed of homopolymers of vinyltoluene, and styrene resins mainly composed of copolymers having a monomer composition containing two or more of styrene, α-methylstyrene, and vinyltoluene, etc.

[0085] From the viewpoint of further improving the interlayer adhesiveness, as the component (B), a tackifier in which the content of the structural unit derived from an aromatic monomer is 20% by mass or more with respect to the entire structural unit of the component (B) is preferred. From the same viewpoint, the content of the structural unit derived from an aromatic monomer is more preferably 35% by mass or more, still more preferably 40% by mass or more, particularly preferably 50% by mass or more, and especially preferably 60 to 100% by mass.

[0086] In addition, when the component (B) contains a structural unit other than the structural unit derived from an aromatic monomer (for example, when it contains a structural unit derived from an aliphatic monomer), its content is preferably 80% by mass or less, more preferably 65% by mass or less, still more preferably 55% by mass or less, particularly preferably 45% by mass or less, and especially preferably 40% by mass or less with respect to the entire structural unit of the component (B).

[0087] The softening point of the component (B) is not particularly limited. For example, it is preferably 50 to 200 °C, more preferably 60 to 150 °C, still more preferably 70 to 120 °C. In addition, the softening point is measured by the ring and ball method in accordance with JIS K2207.

[0088] The content of the component (B) is not particularly limited. From the viewpoint of significantly exerting the effects of the present invention, it is preferably 1.25 to 10 parts by mass, more preferably 2.5 to 8 parts by mass, still more preferably 3 to 7 parts by mass with respect to 100 parts by mass of the component (A).

[0089] [(C) Bismaleimide compound]

[0090] As the component (C) for this rubber composition, it is a compound having two maleimide groups in the molecule, and examples include aromatic bismaleimide compounds and aliphatic bismaleimide compounds. These can be used alone or in combination of two or more.

[0091] An aromatic bismaleimide compound is a compound including a bismaleimide structure and a structure having an aromatic ring. As the structure having an aromatic ring, for example, an aryl group or an arylene group having 6 to 30 carbon atoms can be cited. The above aryl group and arylene group may have substituents. As the structure having the above aromatic ring, for example, a phenylene group, a methylphenylene group, an ethylphenylene group, a propylphenylene group, a butylphenylene group, a dimethylphenylene group, a diethylphenylene group, a dipropylphenylene group, a trimethylphenylene group, a tetramethylphenylene group, a dibutylphenylene group, a naphthylene group, a biphenylene group, a fluorene group, a phenanthrene group, an anthraquinone group, etc. can be cited. Among them, a phenylene group is preferred.

[0092] As specific examples of the aromatic bismaleimide compound, for example, N,N'-(1,3-phenylene)bismaleimide, N,N'-(4-methyl-1,3-phenylene)bismaleimide, N,N'-(1,4-phenylene)bismaleimide, N,N'-(1,2-phenylene)bismaleimide, N,N'-(1,5-naphthylene)bismaleimide, N,N'-(4-chloro-1,3-phenylene)bismaleimide, N,N'-(methylenediphenylene)bismaleimide, N,N'-(4,4'-biphenylene)bismaleimide, N,N'-(sulfonyldiphenylene)bismaleimide, N,N'-(oxydiphenylene)bismaleimide, N,N'-(3,3'-dimethyl-4,4'-biphenylene)bismaleimide, N,N'-(benzylidenephenylene)bismaleimide, N,N'-[methylenebis(3-chloro-4-phenylene)]bismaleimide, N,N'-[methylenebis(3-methyl-4-phenylene)]bismaleimide, N,N'-[methylenebis(3-methoxy-4-phenylene)]bismaleimide, N,N'-(thiodiphenylene)bismaleimide, N,N'-3,3'-benzophenone bismaleimide, N,N'-[methylenebis(3-methyl-5-ethyl-4-phenylene)]bismaleimide, N,N'-[tetramethylenebis(oxyphenylene)]bismaleimide, 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane, bis[4-(4-maleimidophenoxy)phenyl]sulfone, 1,4-phenylene bis(4-maleimidophenoxy), bis[3-(4-maleimidophenoxy)phenyl]sulfone, bis[4-(3-maleimidophenoxy)phenyl]ketone, 1,3-phenylene bis(4-maleimidophenoxy), bis[4-(4-maleimidophenylthio)phenyl]ether, etc. can be cited. Among them, N,N'-(1,3-phenylene)bismaleimide is preferred.

[0093] As the aliphatic bismaleimide compound, for example, N,N'-(2,2,4-trimethylhexamethylene) bismaleimide, N,N'-decamethylene bismaleimide, N,N'-octamethylene bismaleimide, N,N'-heptamethylene bismaleimide, N,N'-hexamethylene bismaleimide, N,N'-pentamethylene bismaleimide, N,N'-tetramethylene bismaleimide, N,N'-trimethylene bismaleimide, N,N'-ethylene bismaleimide, N,N'-(oxydimethylene) bismaleimide, 1,13-bismaleimide-4,7,10-trioxatridecane, 1,11-bismaleimide-3,6,9-trioxaundecane, etc. can be cited.

[0094] In the above component (C), from the viewpoint of significantly exerting the effects of the present invention, an aromatic bismaleimide compound is preferred. It is presumed that by using an aromatic bismaleimide compound as the component (C), the affinity for the component (A) is reduced, and the transfer to the interface is further promoted. As a result, higher interlayer adhesiveness can be obtained.

[0095] The content of the component (C) is not particularly limited. From the viewpoint of significantly exerting the effects of the present invention, it is preferably 1.25 to 10 parts by mass, more preferably 2.5 to 8 parts by mass, and still more preferably 4 to 7 parts by mass with respect to 100 parts by mass of the component (A).

[0096] The mass ratio (B / C) of the component (B) to the component (C) is not particularly limited. From the viewpoint of balancing the interlayer adhesiveness and the compression set, it is preferably 0.25 to 1.5. When it is outside the above range, there is a tendency that it is difficult to balance the interlayer adhesiveness and the compression set.

[0097] The above mass ratio (B / C) can be appropriately set within the above range and is not particularly limited. From the viewpoint of balancing the interlayer adhesiveness and the compression set, for example, it can be 0.4 to 1.3, 0.5 to 1.2, 0.7 to 1.1, etc.

[0098] The total content (B + C) of the component (C) and the component (B) is not particularly limited. From the viewpoint of balancing the interlayer adhesiveness and the compression set, it is preferably 2.5 to 20 parts by mass, more preferably 4.5 to 14 parts by mass, and still more preferably 5 to 14 parts by mass with respect to 100 parts by mass of the component (A). When it is outside the above range, there is a tendency that it is difficult to balance the interlayer adhesiveness and the compression set.

[0099] The above total content (B + C) can be appropriately set within the above range, without particular limitation. From the viewpoint of balancing interlayer adhesiveness and compression set, for example, it can be 6 to 12 parts by mass or the like.

[0100] [(D) Vulcanizing agent]

[0101] As the component (D), sulfur-based vulcanizing agents and peroxide-based vulcanizing agents can be cited. These can be used alone or two or more of them can be used in combination.

[0102] As the sulfur-based vulcanizing agent, for example, powdered sulfur, precipitated sulfur, colloidal sulfur, surface-treated sulfur, insoluble sulfur, etc. can be cited.

[0103] As the peroxide-based vulcanizing agent, for example, 2,4-dichlorobenzoyl peroxide, benzoyl peroxide, 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-dibenzoylperoxyhexane, n-butyl 4,4'-di-tert-butylperoxypentanoate, dicumyl peroxide, tert-butyl peroxybenzoate, di-tert-butyl peroxide diisopropylbenzene, tert-butyl peroxyisopropylbenzene, 2,5-dimethyl-2,5-di-tert-butylperoxyhexane, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di-tert-butylperoxyhexane-3, 1,3-bis-(tert-butylperoxyisopropyl)benzene, etc. can be cited.

[0104] When using a sulfur-based vulcanizing agent as the component (D), from the viewpoint of significantly exerting the effects of the present invention, the content of the sulfur-based vulcanizing agent is preferably 0.5 to 15 parts by mass, particularly preferably 1 to 5 parts by mass, relative to 100 parts by mass of the component (A).

[0105] When using a peroxide-based vulcanizing agent as the component (D), from the viewpoint of significantly exerting the effects of the present invention, the content of the peroxide-based vulcanizing agent is preferably 0.5 to 30 parts by mass, more preferably 1 to 20 parts by mass, and still more preferably 1.5 to 10 parts by mass, relative to 100 parts by mass of the component (A).

[0106] [Other components]

[0107] In this rubber composition, on the basis of the above components (A) to (D), there is no particular limitation, and components for rubber compositions can be appropriately blended as needed, for example, vulcanization accelerators, fillers, plasticizers, vulcanization aids, anti-aging agents, processing aids, etc.

[0108] As the vulcanization accelerator, there is no particular limitation. For example, thiuram vulcanization accelerators such as tetramethylthiuram disulfide ((TMTD), tetraethylthiuram disulfide (TETD), tetrabutylthiuram disulfide ((TBTD), tetra(2-ethylhexyl)thiuram disulfide (TOT), tetrabenzylthiuram disulfide (TBzTD), etc.; sulfenamide vulcanization accelerators such as N-oxydiethylene-2-benzothiazole sulfenamide (NOBS), N-cyclohexyl-2-benzothiazole sulfenamide (CBS), N-tert-butyl-2-benzothiazole sulfenamide (BBS), N,N′-dicyclohexyl-2-benzothiazole sulfenamide, etc.; thiazole vulcanization accelerators such as dibenzothiazole disulfide (MBTS), 2-mercaptobenzothiazole (MBT), sodium salt of 2-mercaptobenzothiazole (NaMBT), zinc salt of 2-mercaptobenzothiazole (ZnMBT), etc.; dithiocarbamate vulcanization accelerators such as zinc dibutyldithiocarbamate (ZnBDC), etc.; sulfur chloride, sulfur disulfide, etc. These can be used alone or two or more of them can be used in combination.

[0109] The content of the vulcanization accelerator is not particularly limited, and is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, and still more preferably 1 to 5 parts by mass relative to 100 parts by mass of the component (A).

[0110] There is no particular limitation on the filler. For example, carbon black, talc, mica, clay, calcium carbonate, etc. can be mentioned. These can be used alone or two or more of them can be used in combination.

[0111] There is no particular limitation on the carbon black. For example, carbon blacks of various grades such as SAF grade, ISAF grade, HAF grade, MAF grade, FEF grade, GPF grade, SRF grade, FT grade, MT grade, etc. can be mentioned.

[0112] The content of the filler is not particularly limited, and is preferably 20 to 180 parts by mass, more preferably 50 to 160 parts by mass relative to 100 parts by mass of the component (A).

[0113] There is no particular limitation on the plasticizer. For example, aromatic oils, ether ester plasticizers, processing oils, etc. can be mentioned. These can be used alone or two or more of them can be used in combination.

[0114] As the aromatic oil, for example, DIANA PROCESS AC-12, DIANA PROCESS AC-460, DIANA PROCESS AH-16 (manufactured by Idemitsu Showa Shell Co., Ltd.), JSO AROMA 790 (manufactured by JAPAN SUN OIL Co., Ltd.), AROMAX1, AROMAX3 (manufactured by Fuji Kosan Co., Ltd.) etc. can be mentioned. In addition, as the ether ester plasticizer, a plasticizer having both an ether bond and an ester bond in one molecule can be mentioned. Specifically, ether ester adipate plasticizers such as bis[2-(2-butoxyethoxy)ethyl] adipate etc. can be mentioned. In addition, as the processing oil, for example, naphthenic oil, paraffinic oil etc. can be mentioned.

[0115] The content of the plasticizer is not particularly limited, and is preferably 5 to 100 parts by mass, more preferably 20 to 80 parts by mass, relative to 100 parts by mass of the component (A).

[0116] There is no particular limitation on the vulcanization aid. For example, zinc oxide, zinc monoxide (ZnO), stearic acid, magnesium oxide etc. can be mentioned. These can be used alone, or two or more of them can be used in combination.

[0117] As the zinc oxide, for example, zinc oxide one, zinc oxide two, zinc oxide three, fine zinc oxide etc. can be mentioned.

[0118] The content of the vulcanization aid is not particularly limited, and is preferably 1 to 25 parts by mass, more preferably 3 to 10 parts by mass, relative to 100 parts by mass of the component (A).

[0119] <<Laminated hose>>

[0120] The above-mentioned rubber composition of the present invention is used as a material for a rubber layer constituting a laminated hose. The laminated hose includes, for example, a laminated structure in which a rubber layer composed of a vulcanizate of the rubber composition of the present invention and a resin layer that is an adherend to the rubber layer are laminated.

[0121] As the resin that is the main component of the resin layer, for example, one or more selected from the group consisting of polyesters such as polyethylene terephthalate, polyvinyl alcohol, aramid (aromatic polyamide), polyamides such as polyamide 6, polyamide 66 etc. can be mentioned.

[0122] The resin layer is not particularly limited as long as it exhibits specific functions such as a strengthening function and a permeation resistance function. From the viewpoint of significantly exhibiting the effects of the present invention, it is preferably a reinforcing layer, and more preferably a reinforcing wire layer composed of resin reinforcing wires.

[0123] As the reinforcing filaments constituting the reinforcing filament layer, for example, polyester filaments such as polyethylene terephthalate filaments, polyvinyl alcohol filaments, aramid (aromatic polyamide) filaments, polyamide filaments such as polyamide 6 and polyamide 66 can be cited. These can be used alone, or two or more of them can be used in combination. Among them, from the viewpoint of the durability of the laminated hose, one or more reinforcing filaments selected from the group consisting of polyamide filaments, polyethylene terephthalate filaments, and polyvinyl alcohol filaments are preferred.

[0124] In addition, the reinforcing filament layer can also be a reinforcing filament layer after impregnation treatment with an adhesive. The reinforcing filament layer after impregnation treatment can be a layer formed by weaving the reinforcing filaments after the impregnation treatment, or can be a layer obtained by subjecting the reinforcing filament layer formed by weaving the reinforcing filaments to the impregnation treatment.

[0125] The above-mentioned weaving method of the reinforcing filaments is not particularly limited. For example, spiral weaving, ribbon weaving, etc. can be cited.

[0126] 〔Manufacturing method of laminated hose〕

[0127] Refer to Figure 1 An example of the manufacturing method of the laminated hose using the present rubber composition will be described.

[0128] First, the above components (A) to (D) and other components as required are compounded, and they are kneaded using a kneading machine such as a roll, a kneader, or a Banbury mixer to prepare the present rubber composition. Then, after the present rubber composition is extruded into a hose shape, on the outer peripheral surface of the extruded product, for example, the reinforcing filaments are wound in a spiral shape to form the reinforcing filament layer 2. Next, on the outer peripheral surface of the above reinforcing filament layer 2, the present rubber composition is extruded, and the obtained hose-shaped laminate is heated under predetermined conditions, whereby a laminated hose having a three-layer structure (inner rubber layer 1 / reinforcing filament layer 2 / outer rubber layer 3) in which the reinforcing filament layer 2 is integrally formed on the outer peripheral surface of the inner rubber layer 1 and the outer rubber layer 3 is integrally formed on the outer peripheral surface of the reinforcing filament layer 2 can be obtained (refer to Figure 1 ).

[0129] In addition, since the rubber layers (inner rubber layer 1, outer rubber layer 3) composed of the present rubber composition have high interlayer adhesiveness with the reinforcing filament layer 2, the above-mentioned lamination can be formed without coating an adhesive (adhesive-free), but an adhesive can also be used as required.

[0130] The size of the laminated hose thus obtained is not particularly limited. The outer diameter of the laminated hose is generally about 8 to 50 mm, and the total thickness (hose wall thickness) of the laminated hose is generally about 1.8 to 6 mm. In addition, the thickness of each layer constituting the laminated hose is not particularly limited as long as it is within the range capable of achieving the target functions of each layer. For example, the thickness of the inner rubber layer 1 is generally about 1 to 4 mm, and the thickness of the outer rubber layer 3 is generally about 0.8 to 2 mm.

[0131] In addition, in one embodiment of the present invention, it is not necessary to form both the inner rubber layer 1 and the outer rubber layer 3 with rubber layers formed by using the rubber composition containing the above components (A) to (D). Either one of the inner rubber layer 1 and the outer rubber layer 3 can be formed into a general rubber layer using a general rubber material.

[0132] In the case of forming a general rubber layer composed of a composition other than the present rubber composition, there is no particular limitation on its material. For example, component (A), chloroprene rubber (CR), styrene-butadiene rubber (SBR), acrylate rubber (ACM), ethylene acrylate rubber (AEM), chlorinated polyethylene (CM), chlorosulfonated polyethylene (CSM), etc. can be cited. In addition, acrylonitrile-butadiene rubber (NBR), hydrogenated acrylonitrile-butadiene rubber (HNBR), acrylate rubber (ACM), ethylene acrylate rubber (AEM), chlorinated polyethylene (CM), chlorosulfonated polyethylene (CSM), fluororubber (FKM), etc. can also be used. These can be used alone or in combination of two or more. In addition, in this rubber layer, additives such as fillers and plasticizers can be appropriately blended as needed.

[0133] As a preferred embodiment of the present invention, an embodiment is that one of the inner rubber layer 1 or the outer rubber layer 3 is a rubber layer formed by using the present rubber composition containing the above components (A) to (D), and the other of the inner rubber layer 1 or the outer rubber layer 3 is a rubber layer formed by using a rubber composition containing the above component (A) and component (D). More preferably, an embodiment is that both the inner rubber layer 1 and the outer rubber layer 3 are rubber layers formed by using the present rubber composition containing the above components (A) to (D).

[0134] In addition, the laminated hose according to one embodiment of the present invention is not limited to the Figure 1 shown three-layer structure (inner rubber layer 1 / reinforcing wire layer 2 / outer rubber layer 3). As long as it has a laminated structure of two or more layers including a rubber layer composed of the present rubber composition and other layers (for example, a reinforcing wire layer, etc.), there is no particular limitation.

[0135] For example, in a laminated hose having a laminated structure of "resin layer (innermost layer) / rubber layer", a laminated hose in which the rubber layer is a rubber layer made of this rubber composition can be cited. In a laminated hose having a four-layer structure of "resin layer (innermost layer) / inner rubber layer / reinforcing layer (such as a reinforcing layer made of a metal wire, etc.) / outer rubber layer", a laminated hose in which the inner rubber layer and / or the outer rubber layer is a rubber layer made of this rubber composition can be cited.

[0136] In addition, as a preferred specific example of the layer structure in the laminated hose according to the embodiment of the present invention, it is not limited to the following, but specifically, for example, in a laminated hose having a three-layer structure of "inner rubber layer / reinforcing wire layer / outer rubber layer", a laminated hose in which the inner rubber layer and / or the outer rubber layer is a rubber layer made of this rubber composition can be cited. In addition, for example, in a laminated hose having a four-layer structure of "inner rubber layer / intermediate rubber layer / reinforcing wire layer / outer rubber layer", a laminated hose in which the intermediate rubber layer and / or the outer rubber layer is a rubber layer made of this rubber composition can be cited.

[0137] In addition, for example, in a laminated hose having a five-layer structure of "inner rubber layer / reinforcing wire layer / intermediate rubber layer / reinforcing wire layer / outer rubber layer", a laminated hose in which a part of the layers (one or two layers) or the entire layer of the inner rubber layer, the intermediate rubber layer, and the outer rubber layer is a rubber layer made of this rubber composition can be cited.

[0138] The use of the laminated hose according to an embodiment of the present invention is not particularly limited, and it can be preferably used as a radiator hose for connecting an engine and a radiator in a vehicle such as a motor vehicle, a heater hose for connecting an engine and a heater core, etc., an engine cooling system hose, a cooler refrigerant transport hose, a methanol fuel hose, a hydrogen fuel hose, etc. for a fuel cell vehicle, a gasoline fuel hose, etc. for a motor vehicle.

[0139]

Examples

[0140] Next, the examples of the present invention will be described together with the comparative examples. However, the present invention is not limited to these examples.

[0141] First, before the examples and the comparative examples, the following materials were prepared as components (A) to (D).

[0142] [EPDM (Component A)]

[0143] (A-1) Manufactured by Sumitomo Chemical Co., Ltd., Esprene (registered trademark) EPDM552 (iodine value: 12, ethylene ratio: 55% by mass)

[0144] [Adhesive (Component B)]

[0145] (B-1) Manufactured by Tosoh Corporation, Petrotack (registered trademark) 90HS (aromatic monomer ratio: 20% by mass, petroleum resin)

[0146] (B-2) Manufactured by Tosoh Corporation, Petrotack (registered trademark) 100V (aromatic monomer ratio: 40% by mass, petroleum resin)

[0147] (B-3) Manufactured by Tosoh Corporation, Petrotack (registered trademark) 90 (aromatic monomer ratio: 70% by mass, petroleum resin)

[0148] (B-4) Manufactured by Tosoh Corporation, Petcoal (registered trademark) LX (aromatic monomer ratio: 100% by mass, petroleum resin)

[0149] (B-5) Manufactured by Nippon Paint Chemical Co., Ltd., Neat Resin (registered trademark) Coumarone G-90 (aromatic monomer ratio: 100% by mass, coumarone resin)

[0150] [Tackifier (Component B')]

[0151] (B'-1) Manufactured by Arakawa Chemical Industries, Ltd., Arkon (registered trademark) P-90 (aromatic monomer ratio: 0% (aliphatic monomer ratio: 100%), hydrogenated petroleum resin)

[0152] [Bismaleimide compound (Component C)]

[0153] (C-1) Manufactured by Tokyo Chemical Industry Co., Ltd., N,N'-(1,3-phenylene)bismaleimide

[0154] [Vulcanizing agent (Component D)]

[0155] (D-1) Manufactured by Tsurumi Chemical Industry Co., Ltd., SULFAX (registered trademark) PS (sulfur-based vulcanizing agent)

[0156] (D-2) Manufactured by NOF Corporation, Percumyl (registered trademark) D (peroxide-based vulcanizing agent)

[0157] [Examples 1 - 10, Comparative Examples 1 - 8]

[0158] First, the components (A) - (D) were set to the ratios shown in Table 1 below, and as optional components, 4 parts by mass of vulcanization accelerator, 155 parts by mass of filler, 5 parts by mass of zinc oxide, and 70 parts by mass of plasticizer were used (the above are ratios relative to 100 parts by mass of Component (A)). These components were kneaded to prepare a rubber composition for the rubber layer.

[0159] Specifically, for the component (A), components other than the component (D) and the vulcanization accelerator were added, and after kneading in a 1.7 L Banbury mixer, the component (D) and the vulcanization accelerator were added and mixed in an 8-inch roll to prepare a rubber composition for a rubber layer.

[0160] In addition, 1 part by mass each of tetramethylthiuram disulfide, tetraethylthiuram disulfide, N-cyclohexyl-2-benzothiazolesulfenamide, and zinc dibutyldithiocarbamate (total 4 parts by mass) were used as the above vulcanization accelerator. As the above filler, 120 parts by mass of SRF grade carbon black, 15 parts by mass of talc, and 20 parts by mass of clay (total 155 parts by mass) were used, and a paraffin-based processing oil was used as the above plasticizer.

[0161] For the rubber compositions for rubber layers obtained in the above-described examples and comparative examples, the properties were evaluated according to the following criteria. The results are shown in Table 1 described later.

[0162] [Interlayer adhesion test (wire, rubber pull-out test)]

[0163] An unvulcanized rubber sheet (120 mm × 120 mm × 2 mm) of the rubber composition for a rubber layer was prepared respectively ( Figure 2 rubber sheets 11 and 13 therein), and as shown in Figure 2 , five reinforcing wires 12 with a total length of 300 mm (manufactured by TORAY, S-1400T / 1HH (polyamide fiber [nylon 66])) (rubber contact part is about 30 mm) were arranged on one of the rubber sheets (rubber sheet 11), and another rubber sheet (rubber sheet 13) was laminated, and vulcanized by hot pressing at 150 °C for 30 minutes to prepare a test piece. Then, the reinforcing wire 12 was stretched at 50 mm / min, and the pull-out strength at this time was measured and evaluated according to the following criteria.

[0164] (Evaluation criteria)

[0165] 〇 (good)... The pull-out strength is 40 N / root or more.

[0166] × (bad)... The pull-out strength is less than 40 N / root.

[0167] [Compression set test]

[0168] According to JIS K 6262, a circular test piece (large test piece) with a diameter of 29 mm and a thickness of 12.5 mm was produced by vulcanizing a rubber layer with a rubber composition using a predetermined mold and maintaining it at 150 °C for 30 minutes. For the obtained test piece, according to JIS K 6262, in a state of 25% compression, it was left standing at 125 °C for 24 hours, the compression set (%) was measured, and evaluation was carried out according to the following criteria.

[0169] (Evaluation Criteria)

[0170] ◎ (Very Good)… Compression set (%) is less than 65%.

[0171] 〇 (Good)… Compression set (%) is 65% or more and 70% or less.

[0172] × (Poor)… Compression set (%) is greater than 70%.

[0173]

Table 1

[0174]

[0175] The results in the above table show that in a multi-layer hose using a rubber composition not containing any of the components (A) to (D) as in the comparative example, the adhesiveness between the rubber layer and the reinforcing wire layer is insufficient.

[0176] Specifically shown, in the case of not containing components (B) and (C) as in Comparative Examples 1 and 2; in the case of not containing component (B) as in Comparative Examples 3 and 8; in the case of not containing component (C) as in Comparative Examples 4 to 7, the adhesiveness between the rubber layer and the reinforcing wire layer is insufficient.

[0177] On the other hand, it is shown that in a multi-layer hose using a rubber composition containing all of the components (A) to (D) as in the examples, the adhesiveness between the rubber layer and the reinforcing wire layer is excellent.

[0178] In addition, the results in the above table show that in a multi-layer hose using a rubber composition not containing any of the components (A) to (D) as in the comparative example, it is impossible to balance the interlayer adhesiveness and the compression set property.

[0179] On the other hand, it is shown that in a multi-layer hose using a rubber composition containing all of the components (A) to (D) as in the examples, it is possible to balance the interlayer adhesiveness and the compression set property.

[0180] Furthermore, in order to verify the influence of the ratio of the aromatic monomer in component (B) (the ratio of the structural units derived from the aromatic monomer) on the interlayer adhesiveness, cases with the same conditions except for the ratio of the aromatic monomer in component (B) were compared. Specifically, Examples 1 to 4 (the ratios were 20% by mass, 40% by mass, 70% by mass, and 100% by mass) and Comparative Example 3 (the ratio was 0% by mass) were compared.

[0181] As a result, when the result (N / root) of the [interlayer adhesiveness test (thread, rubber pull-out test)] of Comparative Example 3 was used as a reference and indexed to 100, Example 1 was 150, and Examples 2 to 4 were 175 or more. Therefore, it is shown that from the viewpoint of improving the interlayer adhesiveness, the ratio of the aromatic monomer in component (B) (the ratio of the structural units derived from the aromatic monomer) is preferably 20% by mass or more, and particularly preferably 40% by mass or more.

[0182] In the above embodiments, specific modes of the present invention are shown, but the above embodiments are merely simple examples and are not to be construed in a limiting sense. It is intended that various modifications apparent to those skilled in the art fall within the scope of the present invention.

[0183] Industrial Applicability

[0184] The rubber composition for a rubber layer of the present invention is suitable, for example, for a rubber layer of a motor vehicle hose. For example, it can be preferably used as a radiator hose for connecting an engine and a radiator in a vehicle such as a motor vehicle, a heater hose for connecting an engine and a heater core, etc., an engine cooling system hose, a refrigerant transport hose for a cooler, a methanol fuel hose, a hydrogen fuel hose for a fuel cell vehicle, a gasoline fuel hose for a motor vehicle, etc. In addition, the motor vehicle hose of the present invention can be used not only for motor vehicles but also for other transportation machines (industrial transport vehicles such as airplanes, forklifts, forklift trucks, cranes, etc., railway vehicles, etc.).

[0185] Explanation of Reference Numerals

[0186] 1: Inner rubber layer;

[0187] 2: Reinforcing wire layer;

[0188] 3: Outer rubber layer.

Claims

1. A rubber composition for a rubber layer of a laminated hose, wherein: The rubber composition for the rubber layer contains the following components (A) to (D), (A) an ethylene-propylene-diene terpolymer, (B) a tackifier comprising a structural unit derived from an aromatic monomer, (C) a bismaleimide compound, (D) Vulcanizing agent.

2. The rubber composition for a rubber layer according to claim 1, wherein The component (B) is a tackifier containing 20% ​​by mass or more of a structural unit derived from an aromatic monomer.

3. The rubber composition for a rubber layer according to claim 1 or 2, wherein The total content (B+C) of the components (B) and (C) is 2.5 to 20 parts by mass based on 100 parts by mass of the component (A).

4. The rubber composition for a rubber layer according to any one of claims 1 to 3, wherein The mass ratio (B / C) of the component (B) to the component (C) is 0.25 to 1.

5.

5. The rubber composition for a rubber layer according to any one of claims 1 to 4, wherein The component (C) is an aromatic bismaleimide compound.

6. The rubber composition for a rubber layer according to any one of claims 1 to 5, wherein The component (B) is a thickener further comprising a structural unit derived from an aliphatic monomer.

7. The rubber composition for a rubber layer according to any one of claims 1 to 6, wherein The laminated hose is a laminated hose including a laminated structure in which a rubber layer and a resin layer are laminated.

8. The rubber composition for a rubber layer according to claim 7, wherein The resin layer is a reinforcing yarn layer composed of at least one reinforcing yarn selected from the group consisting of polyamide yarn, polyethylene terephthalate yarn, and polyvinyl alcohol yarn.

9. A laminated hose, wherein: The laminated hose includes a laminated structure in which a rubber layer composed of a vulcanized product of the rubber composition for a rubber layer according to any one of claims 1 to 6 and a resin layer are laminated.

10. The laminated hose according to claim 9, wherein: The resin layer is a reinforcing wire layer.

11. A laminated hose for a motor vehicle, wherein: The laminated hose for automobiles comprises a laminated structure in which a first rubber layer composed of a vulcanized product of the rubber composition for a rubber layer according to any one of claims 1 to 6, a reinforcing yarn layer, and a second rubber layer composed of a vulcanized product of the rubber composition for a rubber layer containing the components (A) and (D) are laminated in this order.

12. The laminated hose for automobiles according to claim 11, wherein: The second rubber layer is a rubber layer composed of a vulcanized product of the rubber composition for a rubber layer further containing the component (B) and / or the component (C).

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