Industrial hose

Abstract

Provided is an industrial hose having excellent heat resistance and excellent adhesion between a rubber layer and a reinforcing layer formed from a plated wire. An industrial hose having a rubber layer formed from a rubber composition containing the following components (A) to (D): 0.5 to 1.0 parts by mass of component (C) and 1.0 to 3.0 parts by mass of component (D) per 100 parts by mass of component (A), and having a mass ratio [(C) / (B)] of component (C) to component (B) of 0.5 to 1.0, and a reinforcing layer that is in contact with the rubber layer and is formed from a plated wire, the reinforcing layer being characterized in that the content of component (C) is 0.5 to 1.0 parts by mass per 100 parts by mass of component (A), the content of component (D) being 1.0 to 3.0 parts by mass per 100 parts by mass of component (A), and the mass ratio [(C) / (B)] of component (C) to component (B) being 0.5 to 1.0 part by mass per 100 parts by mass of component (A). The mass ratio [(D) / {(B) + (C) + (D)}] of component (D) to the total amount of components (B)-(D) is 0.3-0.6. (A) A diene rubber. And (B) at least one of a sulfenamide-based vulcanization accelerator and a thiazole-based vulcanization accelerator. And (C) N-phenyl-N-(trichloromethylthio) benzenesulfonamide. (D) sulfur.

Description

Technical Field

[0001] The present invention relates to an industrial hose having a rubber layer and a reinforcement layer formed of a plated electric wire. More specifically, it relates to an industrial hose having a rubber layer and a reinforcement layer formed of a plated electric wire connected to the rubber layer, such as a high-pressure oil pressure hose for industrial machinery such as construction machinery (construction machinery) and mining (excavation) machinery, and various hoses for automobiles. Background Art

[0002] Industrial hoses used in construction machinery, mining machinery, etc. are provided with a reinforcement layer formed of plated electric wires together with a rubber layer to make them withstand high pressure. If the adhesion between the reinforcement layer and the rubber layer is insufficient, the plated electric wires move or loosen, which adversely affects durability. Therefore, the reinforcement layer formed of the plated electric wires and the rubber layer in contact therewith must be firmly bonded.

[0003] In order to firmly bond the above-mentioned reinforcement layer and the rubber layer, as a method without using an adhesive (adhesive-free), for example, there is a method as follows: the reinforcement layer is formed by a copper-containing wire such as a brass-plated (copper-zinc alloy) wire, and a diene rubber composition is used as the material of the rubber layer. Through the chemical bonding of the vulcanizing agent, i.e., sulfur in the rubber layer material and the copper ions (Cu) in the reinforcement layer, the rubber layer near the interface with the reinforcement layer is made into a copper sulfide-containing layer, thereby reflecting the adhesion between the reinforcement layer and the rubber layer. However, if the amount of sulfur compounded in the diene rubber composition increases, the bonding between copper and sulfur increases, so that the adhesion is improved, but there is a tendency that the heat resistance will decrease. In particular, in the case of high-pressure oil pressure hoses for industrial machinery, in hoses where high-temperature fluids (such as working oils above 100°C) flow, thermal degradation caused by reduced heat resistance becomes a serious problem.

[0004] On the other hand, as a method of using an adhesive to improve the adhesion between the above-mentioned reinforcement layer and the rubber layer, for example, a hose having a rubber layer in which an adhesive such as resorcinol or hexamethylenetetramine is compounded with a raw rubber that can be sulfur-vulcanized is proposed (Patent Document 1). In addition, for example, a hose having a rubber layer in which a cobalt-based compound serving as an adhesive is compounded with acrylonitrile-butadiene rubber is proposed (Patent Document 2). However, both Patent Documents 1 and 2 are insufficient from the viewpoint of achieving both adhesion and heat resistance.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Publication No. 6-84793

[0008] Patent Document 2: Japanese Patent Application Publication No. 2011-1524 Summary of the invention

[0009] Problem that the invention aims to solve

[0010] In addition, in recent years, there has been a high demand for adhesion (peeling durability) between the rubber layer and the reinforcing layer in industrial hoses. It is difficult to highly satisfy both adhesion and heat resistance with conventional methods, and development of a new method is strongly desired.

[0011] The present invention has been made in view of such circumstances, and provides an industrial hose having excellent adhesion between a rubber layer and a reinforcement layer formed of a plated electric wire and excellent heat resistance.

[0012] Solutions for solving problems

[0013] The inventors of the present invention have conducted in-depth research to solve the above-mentioned problems. In the course of their research, from the viewpoint of achieving a high balance between adhesion and heat resistance, they focused on the behavior of sulfur in the sulfur vulcanization system and studied a method for controlling the distribution of sulfur after vulcanization. Based on the above viewpoint, the inventors of the present invention have conducted further research and found that by using a specific vulcanization accelerator and N-phenyl-N-(trichloromethylthio)benzenesulfonamide as constituent materials of the rubber layer and controlling the compounding amount of the component, sulfur, etc. within a specific range, an industrial hose having excellent adhesion between the reinforcement layer formed by the plated wire and the rubber layer and excellent heat resistance can be obtained.

[0014] That is, the gist of the present invention lies in the following [1] to [4].

[0015] [1] An industrial hose comprising: a rubber layer formed of a rubber composition and a reinforcement layer formed of a plated electric wire in contact with the rubber layer, the rubber composition comprising the following components (A) to (D), wherein the content of component (C) is 0.5 to 1.0 parts by mass and the content of component (D) is 1.0 to 3.0 parts by mass per 100 parts by mass of component (A), the mass ratio of component (C) to component (B) [(C) / (B)] is 0.5 to 1.0, and the mass ratio of component (D) to the total amount of components (B) to (D) [(D) / {(B)+(C)+(D)}] is 0.3 to 0.6.

[0016] (A) Diene rubber.

[0017] (B) At least one of a sulfenamide-based vulcanization accelerator and a thiazole-based vulcanization accelerator.

[0018] (C) N-phenyl-N-(trichloromethylthio)benzenesulfonamide.

[0019] (D) Sulfur.

[0020] [2] The industrial hose according to [1], wherein the peak intensity of sulfur measured by energy dispersive X-ray spectroscopy (EDX) in the rubber layer within a range of 50 μm from the contact surface with the reinforcement layer is higher than the peak intensity of sulfur measured in the rubber layer outside the range.

[0021] [3] The industrial hose according to [1] or [2], wherein the diene rubber (A) is at least one selected from the group consisting of acrylonitrile butadiene rubber, butadiene rubber, styrene butadiene rubber and natural rubber.

[0022] [4] The industrial hose according to any one of [1] to [3], wherein the rubber composition does not contain one or more adhesives selected from the group consisting of cobalt-based adhesives, melamine-based adhesives, and resorcinol-based adhesives.

[0023] Effects of the Invention

[0024] According to the present invention, it is possible to provide an industrial hose having excellent adhesion between a rubber layer and a reinforcement layer formed of a plated electric wire and excellent heat resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram showing an example of an industrial hose according to an embodiment of the present invention.

[0026] Figure 2 This is a schematic diagram showing an example of an industrial hose according to an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram showing an example of an industrial hose according to an embodiment of the present invention.

[0028] Figure 4 This is an explanatory diagram showing a peel test in adhesiveness evaluation. DETAILED DESCRIPTION

[0029] Next, an embodiment of the present invention will be described in detail, but the present invention is not limited to this embodiment.

[0030] In addition, in this specification, "X and / or Y (X, Y are arbitrary structures)" means at least one of X and Y, and has three meanings: only X, only Y, and X and Y.

[0031] An industrial hose (hereinafter sometimes referred to as "the present hose") according to one embodiment of the present invention is characterized in that it comprises: a rubber layer formed of a rubber composition (hereinafter sometimes referred to as "the rubber composition") and a reinforcement layer formed of a plated electric wire in contact with the rubber layer, wherein the rubber composition contains the following components (A) to (D), wherein the content of the component (C) is 0.5 to 1.0 parts by mass, the content of the component (D) is 1.0 to 3.0 parts by mass, relative to 100 parts by mass of the component (A), the mass ratio of the component (C) to the component (B) [(C) / (B)] is 0.5 to 1.0, and the mass ratio of the component (D) to the total content of the components (B) to (D) [(D) / {(B)+(C)+(D)}] is 0.3 to 0.6.

[0032] (A) Diene rubber.

[0033] (B) At least one of a sulfenamide-based vulcanization accelerator and a thiazole-based vulcanization accelerator.

[0034] (C) N-phenyl-N-(trichloromethylthio)benzenesulfonamide.

[0035] (D) Sulfur.

[0036] The reinforcement layer formed by the plated wire of the present hose has excellent adhesion to the rubber layer and excellent heat resistance. The reason why the present hose can achieve both high adhesion and heat resistance is not necessarily clear, but the present inventors presume as follows. That is, the present inventors presume that by controlling the content and content ratio of the above-mentioned (A) to (D) components within a specific range, (C) N-phenyl-N-(trichloromethylthio)benzenesulfonamide moderately suppresses the interaction between the specific (B) vulcanization accelerator and (D) sulfur, while on the other hand, exerting a predetermined vulcanization accelerating function, thereby causing a proper amount of the predetermined amount of (D) sulfur contained in the rubber layer to migrate to the reinforcement layer side in advance, thereby fully forming an adhesive layer, and on the other hand, using the remaining proper amount of (D) sulfur, and then promoting vulcanization, thereby causing the sulfur present in the cross-linked rubber layer to be in a specific distribution state, resulting in both high adhesion and heat resistance.

[0037] As a more specific example of examination, for example, by chemically reacting (C) N-phenyl-N-(trichloromethylthio)benzenesulfonamide (see (b) of "Chemical 1" below) at a specific content ratio with 2-mercaptobenzothiazole (MBT) (see (a) of "Chemical 1" below) which is a thiazole-based vulcanization accelerator (B), the vulcanization accelerating function of the component (B) after the chemical reaction is appropriately suppressed (see (a) of "Chemical 2" below), and the component (C) after the chemical reaction becomes alkaline and exhibits a vulcanization function (see (b) of "Chemical 2" below). Therefore, an appropriate amount of the (D) sulfur contained in the rubber layer reacts in advance with the copper plating of the plated electric wire constituting the reinforcement layer to generate copper sulfate and the like to form an adhesive layer, while the remaining appropriate amount of the (D) sulfur is subsequently promoted to vulcanize, thereby relatively more monosulfide and disulfide crosslinking structures are expressed, thereby increasing the sulfur concentration near the plated electric wire in the crosslinked rubber layer, and as a result, it is estimated that both adhesion and heat resistance can be highly achieved.

[0038] [Chemistry 1]

[0039]

[0040] [Chemistry 2]

[0041]

[0042] The details of this hose are described below.

[0043] The present hose comprises at least a rubber layer formed of the present rubber composition and a reinforcement layer formed of a plated electric wire. That is, the present hose may be a hose having a laminated structure in which a rubber layer formed of the present rubber composition is formed on the outside and / or inside of a reinforcement layer formed of a plated electric wire, and the composition and number of layers of other layers are not particularly limited.

[0044] <Rubber layer>

[0045] As described above, the rubber layer of the present hose is a rubber layer formed of a rubber composition, the rubber composition comprising (A) a diene rubber, (B) at least one of a sulfenamide vulcanization accelerator and a thiazole vulcanization accelerator, (C) N-phenyl-N-(trichloromethylthio)benzenesulfonamide, and (D) sulfur, wherein the content of the component (C) is 0.5 to 1.0 parts by mass, the content of the component (D) is 1.0 to 3.0 parts by mass, relative to 100 parts by mass of the component (A), the mass ratio of the component (C) to the component (B) [(C) / (B)] is 0.5 to 1.0, and the mass ratio of the component (D) to the total content of the components (B) to (D) [(D) / {(B)+(C)+(D)}] is 0.3 to 0.6.

[0046] 《(A) Diene rubber》

[0047] Examples of the (A) diene rubber include natural rubber (NR), styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), isoprene rubber (IR), butadiene rubber (BR), etc. These may be used alone or in combination of two or more.

[0048] Regarding the diene rubber (A), when the present rubber composition is used as an inner surface rubber layer, NBR is preferably used from the viewpoint of improving oil resistance to the working oil flowing in the hose, etc. When the present rubber composition is used as an inner surface rubber layer, the acrylonitrile content (AN content) of NBR is preferably 10 to 33% by mass, more preferably 18 to 28% by mass, from the viewpoint of achieving both oil resistance and adhesion and cold resistance.

[0049] The content of the diene rubber (A) is, for example, 30% by mass or more, preferably 30 to 80% by mass, more preferably 32 to 70% by mass, and still more preferably 35 to 55% by mass, based on the total amount (100% by mass) of the rubber composition.

[0050] 《(B) Sulfonamide-based vulcanization accelerator or thiazole-based vulcanization accelerator》

[0051] The rubber composition contains at least one of a sulfenamide vulcanization accelerator (b1) and a thiazole vulcanization accelerator (b2) as a vulcanization accelerator. That is, the rubber composition contains a sulfenamide vulcanization accelerator (b1), a thiazole vulcanization accelerator (b2), or both.

[0052] As sulfonamide-based vulcanization accelerator (b1), for example, N-oxydiethylene-2-benzothiazole sulfonamide (NOBS), N-cyclohexyl-2-benzothiazole sulfonamide (CBS), N-tert-butyl-2-benzothiazole sulfonamide (BBS), N,N'-dicyclohexyl-2-benzothiazole sulfonamide, etc. can be cited. They can be used alone or in combination of two or more. Among these, N-oxydiethylene-2-benzothiazole sulfonamide (NOBS) and N-cyclohexyl-2-benzothiazole sulfonamide (CBS) are suitable.

[0053] As thiazole vulcanization accelerator (b2), for example, dibenzothiazyl disulfide (MBTS), 2-mercaptobenzothiazole (MBT), 2-mercaptobenzothiazole sodium salt (NaMBT), 2-mercaptobenzothiazole zinc salt (ZnMBT), 2-(4'-morpholinyl disulfide)benzothiazole, etc. can be mentioned. These can be used alone or in combination of two or more. Among these, dibenzothiazyl disulfide (MBTS) and 2-mercaptobenzothiazole (MBT) are preferably used.

[0054] The content of the component (B) is preferably 0.8 to 3.0 parts by mass, more preferably 1.0 to 2.5 parts by mass, and even more preferably 1.0 to 2.0 parts by mass, based on 100 parts by mass of the diene rubber (A), from the viewpoint of improving the effects of the present invention.

[0055] 《(C) N-phenyl-N-(trichloromethylthio)benzenesulfonamide》

[0056] From the viewpoint of exerting the effect of the present invention, it is important that the content of the component (C) is controlled to be within a specific range of 0.5 to 1.0 parts by mass relative to 100 parts by mass of the diene rubber (A). When the content of the component (C) is outside the above range, it becomes difficult to achieve both adhesion and heat resistance between the rubber layer and the reinforcement layer formed by the plated wire. That is, if the content of the component (C) is too much, there is a tendency for the adhesion to be reduced, and if the content of the component (C) is too little, there is a tendency for the heat resistance and / or adhesion to be reduced.

[0057] The content of the component (C) can be appropriately set within a specific range of 0.5 to 1.0 part by mass, for example, 0.6 to 1.0 part by mass, 0.7 to 0.9 part by mass, etc., based on 100 parts by mass of the diene rubber (A).

[0058] It is important that the mass ratio [(C) / (B)] of the component (C) to the component (B) is in the range of 0.5 to 1.0. When the mass ratio [(C) / (B)] is outside the above range, it becomes difficult to achieve both adhesion and heat resistance between the rubber layer and the reinforcing layer formed by the plated wire. That is, if the mass ratio [(C) / (B)] is too small, there is a tendency for adhesion to decrease.

[0059] The mass ratio [(C) / (B)] can be appropriately set within a specific range of 0.5 to 1.0, and can be, for example, 0.5 to 0.9, 0.5 to 0.8, or the like.

[0060] (D) Sulfur

[0061] It is important that the content of (D) sulfur is controlled to be within a specific range of 1.0 to 3.0 parts by mass relative to 100 parts by mass of (A) diene rubber. When the content of the component (D) is outside the above range, it becomes difficult to achieve both adhesion and heat resistance between the rubber layer and the reinforcing layer formed by the plated electric wire. That is, if the content of the component (D) is too small, there is a tendency for adhesion to decrease, and if the content of sulfur is too large, there is a tendency for heat resistance to decrease.

[0062] The content of the component (D) can be appropriately set within a specific range of 1.0 to 3.0 parts by mass, for example, 1.0 to 2.5 parts by mass, 1.2 to 2.0 parts by mass, etc., based on 100 parts by mass of the diene rubber (A).

[0063] As (D) sulfur, insoluble sulfur and soluble sulfur can be used. As insoluble sulfur, for example, polymeric sulfur such as μ sulfur, π sulfur, and ω sulfur can be mentioned. These can be used alone or in combination of two or more. As commercially available products, Sanfel (manufactured by Sanshin Chemical Industry Co., Ltd.) and Sanfel EX (manufactured by Sanshin Chemical Industry Co., Ltd.) can be mentioned.

[0064] In addition, as soluble sulfur, for example, sulfur having a ring structure such as α sulfur, β sulfur, γ sulfur, and λ sulfur can be cited. These can be used alone or in combination of two or more. As commercial products, GOLDEN FLOWER sulfur powder (manufactured by Tsurumi Chemical Industry Co., Ltd.), powdered sulfur S (manufactured by Hosoi Chemical Industry Co., Ltd.), etc. can be cited.

[0065] In addition, insoluble sulfur refers to sulfur that is insoluble in carbon disulfide by 90% by mass or more, and soluble sulfur refers to sulfur that is soluble in carbon disulfide by 99.5% by mass or more.

[0066] It is important that the mass ratio of the component (D) to the total amount of the components (B) to (D) [(D) / {(B)+(C)+(D)}] is in the range of 0.3 to 0.6. If the mass ratio [(D) / {(B)+(C)+(D)}] is outside the above range, it becomes difficult to achieve both adhesion and heat resistance between the rubber layer and the reinforcement layer formed by the plated electric wire.

[0067] 《Other ingredients》

[0068] The rubber composition may contain any material such as a filler, a plasticizer, an antioxidant, a vulcanization aid, etc., in addition to the above-mentioned components (A) to (D), as required.

[0069] (Bulking Agent)

[0070] Examples of fillers include carbon black, silica, and calcium carbonate. These fillers may be used alone or in combination of two or more. Among these, carbon black is preferred from the viewpoint of improving durability.

[0071] Examples of carbon black include various grades of carbon black such as SAF grade, ISAF grade, HAF grade, MAF grade, FEF grade, GPF grade, SRF grade, FT grade, and MT grade. These may be used alone or in combination of two or more.

[0072] The BET specific surface area of ​​carbon black is preferably 10 to 150 m 2 / g, more preferably 15 to 100 m 2 / g, more preferably 20 to 80 m 2 / g.

[0073] It should be noted that the BET specific surface area of ​​carbon black can be measured, for example, as follows: after degassing the sample at 200°C for 15 minutes, a mixed gas (N2: 70%, He: 30%) is used as the adsorption gas, and the measurement is performed using a BET specific surface area measuring device (manufactured by Microdata, 4232-II).

[0074] The iodine adsorption of carbon black is preferably 10 to 150 mg / g, more preferably 10 to 75 mg / g, and still more preferably 20 to 65 mg / g. The DBP (dibutyl phthalate) absorption of carbon black is preferably 20 to 180 mL / 100 g, and more preferably 20 to 150 mL / 100 g.

[0075] It should be noted that the iodine adsorption amount of carbon black is a value measured in accordance with JIS K 6217-1 (Method A), and the DBP absorption amount of carbon black is a value measured in accordance with JIS K 6217-4.

[0076] The content of the filler is not particularly limited, but is, for example, preferably 40 to 150 parts by mass, more preferably 50 to 140 parts by mass, and even more preferably 60 to 130 parts by mass, based on 100 parts by mass of the (A) diene rubber.

[0077] When carbon black and calcium carbonate are used together, the content ratio of carbon black to calcium carbonate (calcium carbonate / carbon black) is, for example, preferably 1 / 99 to 20 / 80, more preferably 5 / 95 to 15 / 85.

[0078] (Plasticizer)

[0079] The plasticizer can be appropriately selected according to the type of diene rubber, and examples thereof include aromatic oils, ether ester plasticizers, process oils, etc. These may be used alone or in combination of two or more.

[0080] As aromatic oil, for example, Diana Process AC-12, Diana Process AC-460, Diana Process AH-16 (above, Idemitsu Showa Shell KK system), JSO AROMA 790 (Japan SunOil Company, Ltd. system), Aromax 1, Aromax 3 (above, Fuji Kosan Company, LTD. system) etc. can be cited. In addition, as ether ester plasticizer, plasticizer having both ether bond and ester bond in one molecule can be cited. Specifically, adipic acid ether ester plasticizers such as di[2-(2-butoxyethoxy)ethyl] adipate can be cited. In addition, as process oil, for example, cycloparaffinic oil, paraffinic oil etc. can be cited.

[0081] The content of the plasticizer is not particularly limited, but is, for example, 5 to 20 parts by mass, preferably 5 to 18 parts by mass, and more preferably 8 to 15 parts by mass, based on 100 parts by mass of the (A) diene rubber.

[0082] (Antioxidant)

[0083] Examples of the antioxidant include carbamate antioxidants, phenylenediamine antioxidants, phenol antioxidants, aniline antioxidants, diphenylamine antioxidants, quinoline antioxidants, imidazole antioxidants, waxes, etc. These may be used alone or in combination of two or more.

[0084] The content of the antioxidant is not particularly limited, and is, for example, 0.5 to 10 parts by mass, preferably 1 to 8 parts by mass, and more preferably 1.5 to 6 parts by mass, based on 100 parts by mass of the (A) diene rubber.

[0085] (Vulcanization accelerator)

[0086] Examples of the vulcanization aid include zinc oxide, zinc white (ZnO), stearic acid, magnesium oxide, etc. These may be used alone or in combination of two or more.

[0087] The content of the vulcanization aid is not particularly limited, and is, for example, 1 to 12 parts by mass, preferably 2 to 10 parts by mass, and more preferably 3 to 8 parts by mass, based on 100 parts by mass of the (A) diene rubber.

[0088] (Adhesive)

[0089] When the rubber composition contains an adhesive, the adhesiveness is improved, but there is a tendency for the heat resistance to decrease, so it is preferably free of adhesive. In addition, when the adhesive is contained, there are concerns about various manufacturing problems such as the tendency of the rubber composition to adhere to the mandrel (iron core, etc.) and hinder extrusion molding during the manufacturing process of the hose, so it is preferably free of adhesive. Here, "free of adhesive" means that the total content of the adhesive contained in the total amount (100% by mass) of the rubber composition is less than 0.5% by mass. More preferably, the total content of the above-mentioned adhesive is less than 0.3% by mass, more preferably less than 0.1% by mass, further more preferably less than 0.05% by mass, and particularly preferably 0% by mass.

[0090] Specifically, it is preferred that the rubber composition does not contain one or more adhesives selected from the group consisting of cobalt-based adhesives, melamine-based adhesives, and resorcinol-based adhesives. That is, the total content of the cobalt-based adhesive, melamine-based adhesive, and resorcinol-based adhesive contained in the total amount (100% by mass) of the rubber composition is preferably less than 0.5% by mass, more preferably less than 0.3% by mass, even more preferably less than 0.1% by mass, and particularly preferably 0% by mass.

[0091] Examples of the cobalt-based adhesive include cobalt naphthenate, cobalt stearate, cobalt borate, cobalt oleate, cobalt maleate, etc. Examples of the resorcinol-based adhesive include resorcinol, resorcinol derivatives such as resorcinol / formaldehyde obtained by condensing resorcinol and formaldehyde, etc. Examples of the melamine-based adhesive include hexamethoxymethylmelamine, etc.

[0092] (Preparation of rubber composition)

[0093] The rubber composition can be prepared, for example, by appropriately mixing the above-mentioned components (A) to (D) and various optional materials as described above as needed, and kneading them using a kneading machine such as a kneader, a roll, a Banbury mixer, etc. The rubber composition prepared as described above becomes a constituent material of the rubber layer in contact with the reinforcing layer formed by the plated electric wire.

[0094] <Reinforcement layer>

[0095] The present hose has a reinforcing layer formed of plated electric wires to enhance the strength of the hose as a whole. Specifically, the reinforcing layer is a layer formed by braiding the plated electric wires into a plate shape, a spiral shape, or the like.

[0096] As the wire (wire material) to be plated, metal wires, especially steel wires, etc. are suitable. In addition, as the plating treatment, for example, copper plating, zinc plating, brass (copper-zinc alloy) plating, nickel plating, tin plating, cobalt plating, etc. can be cited. Among these, brass (copper-zinc alloy) plating is preferred. The content ratio (Cu / Zn) of copper and zinc in the above-mentioned brass (copper-zinc alloy) plating is not particularly limited, for example, 70 / 30 to 55 / 45, preferably 70 / 30 to 60 / 40.

[0097] The diameter of the plated electric wire is usually 0.15 to 1.00 mm, preferably 0.20 to 0.80 mm.

[0098] <Layer structure>

[0099] The present hose comprises at least a rubber layer formed of the present rubber composition and a reinforcement layer formed of a plated electric wire. As long as the hose is an industrial hose having a laminated structure having a rubber layer formed of the present rubber composition on the outside and / or inside of the reinforcement layer formed of the plated electric wire, the composition and number of other layers are not particularly limited.

[0100] Specific examples of the layer structure in the present hose are not limited to the following, for example, in an industrial hose having a three-layer structure of "inner surface rubber layer / reinforcement layer / outer surface rubber layer", an industrial hose in which the inner surface rubber layer is a rubber layer formed of the present rubber composition can be cited. In addition, in an industrial hose having a four-layer structure of "inner surface rubber layer / intermediate rubber layer / reinforcement layer / outer surface rubber layer", an industrial hose in which the intermediate rubber layer is a rubber layer formed of the present rubber composition can be cited. In addition, in an industrial hose having a five-layer structure of "inner surface rubber layer / reinforcement layer 1 / intermediate rubber layer / reinforcement layer 2 / outer surface rubber layer", an industrial hose in which one or both of the inner surface rubber layer and the intermediate rubber layer are rubber layers formed of the present rubber composition can be cited. In addition, for example, in an industrial hose having a seven-layer structure of "inner surface rubber layer / reinforcement layer 1 / intermediate rubber layer 1 / reinforcement layer 2 / intermediate rubber layer 2 / reinforcement layer 3 / outer surface rubber layer", there can be mentioned an industrial hose in which a part (one layer or two layers) or all of the inner surface rubber layer, the intermediate rubber layer 1 and the intermediate rubber layer 2 are rubber layers formed from the rubber composition.

[0101] The inner diameter of the present hose is not particularly limited, but is usually 5 to 85 mm, preferably 6 to 80 mm. The outer diameter of the present hose is usually 9 to 100 mm, preferably 10 to 85 mm.

[0102] The thickness of each layer is not particularly limited, and the thickness of the inner surface rubber layer is, for example, 0.7 to 4.0 mm, preferably 1.0 to 3.0 mm. The thickness of the entire intermediate rubber layer is, for example, 0.1 to 0.5 mm, preferably 0.2 to 0.4 mm. The thickness of the outer surface rubber layer is, for example, 0.5 to 2.5 mm, preferably 0.8 to 2.0 mm.

[0103] (Peak intensity of sulfur element)

[0104] It is preferred that the peak intensity of sulfur element measured by energy dispersive X-ray spectroscopy (EDX) at a portion within a range of 50 μm from the contact surface with the reinforcing layer in the rubber layer formed from the present rubber composition is higher than the peak intensity of sulfur element measured at a portion outside the above range in the rubber layer. In this case, an adhesive layer is well formed in the rubber layer by a contact reaction with the plating layer of the reinforcing layer, and good adhesion is exhibited.

[0105] In addition, the measurement conditions of the energy dispersive X-ray spectroscopy (EDX) can be performed according to the following conditions, for example.

[0106] [Energy dispersive X-ray spectroscopy (EDX) measurement conditions]

[0107] ·Cross-section processing: ion cutting method

[0108] ·Analysis and measurement conditions

[0109] Device name: Scanning electron microscope S-4800 (manufactured by Hitachi High-Tech Corporation)

[0110] Energy dispersive X-ray microscope X-Max (manufactured by HORIBA, Ltd.)

[0111] Image type: reflected electron image

[0112] Accelerating voltage: 15 kV

[0113] Conductive treatment: C evaporation

[0114] Magnification:×100k

[0115] Element type: Sulfur

[0116] In addition, for the rubber layer formed from the present rubber composition, the tensile stress (M 100 ) is preferably 2.0 MPa or more, more preferably 2.0 to 12.0 MPa. More specifically, when the rubber layer formed from the present rubber composition is an inner surface rubber layer, the tensile stress (M 100) is preferably 7.0 to 10.0 MPa. In addition, when the rubber layer formed by the present rubber composition is used as an intermediate rubber layer, the above tensile stress (M 100 ) is preferably 3.0 to 5.0 MPa.

[0117] It should be noted that the above tensile stress (M 100 ) can be measured, for example, in accordance with JIS K 6251.

[0118] Furthermore, one embodiment of the hose will be described with reference to the drawings, but the present invention is not limited to the structure of the drawings. Figure 1 The high-pressure hose shown is a hose having a five-layer structure in which an intermediate rubber layer 2a is formed on the outer peripheral surface of an inner surface rubber layer 1, a reinforcing layer 3 formed of a plated electric wire is formed on the outer peripheral surface of the intermediate rubber layer 2a, an intermediate rubber layer 2b is formed on the outer peripheral surface of the reinforcing layer 3, and an outer surface rubber layer 4 is formed on the outer peripheral surface of the intermediate rubber layer 2b. In this hose, one or both of the intermediate rubber layer 2a and the intermediate rubber layer 2b are rubber layers formed of the present rubber composition.

[0119] In addition, for example Figure 2 The high-pressure hose shown has an intermediate rubber layer 2 formed on the outer peripheral surface of a reinforcing layer 13a formed of plated electric wires, and a reinforcing layer 13b formed of plated electric wires formed on the outer peripheral surface of the intermediate rubber layer 2. In this hose, the intermediate rubber layer 2 is a rubber layer formed of the present rubber composition.

[0120] In addition, for example Figure 3 The high-pressure hose shown is a hose having a three-layer structure in which a reinforcement layer 3 formed of a plated electric wire is formed on the outer peripheral surface of an inner surface rubber layer 1, and an outer surface rubber layer 4 is formed on the outer peripheral surface of the reinforcement layer 3. In this hose, the inner surface rubber layer 1 is a rubber layer formed of the present rubber composition.

[0121] It should be noted that if Figure 1 The high-pressure hose shown in the invention forms an inner surface rubber layer 1 formed by a composition other than the rubber composition. As its material, a rubber having excellent oil resistance is preferably used, for example, 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 be cited. They can be used alone or in combination of two or more. Among these, NBR is preferred from the aspect of oil resistance, strength and cost.

[0122] In addition to rubber such as NBR, fillers, plasticizers, stearic acid, zinc white, vulcanizing agents, vulcanization accelerators, processing aids, and the like may be appropriately compounded as necessary.

[0123] In addition, if Figure 1 , Figure 3 The high-pressure hose shown in the invention forms an outer surface rubber layer 4 formed by a composition other than the present rubber composition. As its material, a rubber having excellent weather resistance is preferably used, for example, chloroprene rubber (CR), styrene butadiene rubber (SBR), ethylene-propylene-diene rubber (EPDM), a blended rubber of SBR and EPDM, a blended rubber of NBR and EPDM, a blended rubber of NBR and vinyl chloride (PVC), an acrylic rubber (ACM), an ethylene acrylic rubber (AEM), a chlorinated polyethylene (CM), a chlorosulfonated polyethylene (CSM), etc. They can be used alone or in combination of two or more. Among these, CR is preferred from the aspects of weather resistance, cost, and oil resistance.

[0124] In addition to the rubber such as CR, fillers, plasticizers, stearic acid, zinc white, vulcanizing agents, vulcanization accelerators, processing aids, etc. may be appropriately compounded as needed.

[0125] <Manufacturing method>

[0126] by Figure 1 Taking one embodiment of the present invention shown in the figure as an example, the manufacturing method of the present hose is described. First, a rubber composition for forming an inner surface rubber layer is extruded onto a mandrel using an extrusion molding machine to form an inner surface rubber layer 1. Next, a rubber composition for forming an intermediate rubber layer (the present rubber composition) is extruded onto the outer peripheral surface of the inner surface rubber layer 1 to form an intermediate rubber layer 2a. Next, plated wires such as brass plated wires are braided into a spiral shape to form a reinforcing layer 3 on the outer peripheral surface of the intermediate rubber layer 2a. Thereafter, the rubber composition for forming an intermediate rubber layer (the present rubber composition) is extruded onto the outer peripheral surface of the reinforcing layer 3 to form an intermediate rubber layer 2b. Furthermore, the rubber composition for forming an outer surface rubber layer is extruded onto the outer peripheral surface of the intermediate rubber layer 2b to form an outer surface rubber layer 4. Finally, the laminate is vulcanized (steam vulcanization, etc.) under specified conditions (e.g., 140 to 170°C × 10 to 60 minutes), thereby producing a rubber hose. Figure 1 The layer structure of the high-pressure hose is shown.

[0127] In addition, for example Figure 3As shown, in the case of manufacturing a hose having a three-layer structure of "inner surface rubber layer / reinforcement layer / outer surface rubber layer", the rubber composition is extruded onto a mandrel by an extrusion molding machine in the same manner as described above to form an inner surface rubber layer 1, and then a plated wire such as a brass plated wire is braided into a spiral shape to form a reinforcement layer 3 on the outer peripheral surface of the inner surface rubber layer 1, and then a rubber composition for forming the outer surface rubber layer is extruded onto the outer peripheral surface of the reinforcement layer 3 to form an outer surface rubber layer 4. Finally, the laminate is vulcanized (steam vulcanization, etc.) under prescribed conditions (e.g., 140 to 170°C × 10 to 60 minutes), thereby making a high-pressure hose with a three-layer structure.

[0128] <Application>

[0129] This hose is used as a high-pressure oil hose for construction machinery (construction machinery), various hoses for automobiles (such as oil hoses, fuel hoses, air hoses, water hoses, etc.) and other industrial hoses. In particular, it is suitable for use as a high-pressure hose used to circulate high-pressure fluids in construction machinery, civil engineering machinery, industrial machinery, vehicles / ships, etc.

[0130] Example

[0131] Next, examples will be described together with comparative examples, but the present invention is not limited to these examples.

[0132] First, prior to Examples and Comparative Examples, the following materials were prepared.

[0133] <(A) Diene rubber>

[0134] NBR (acrylonitrile butadiene rubber, Nipol DN302, manufactured by Zeon Corporation, AN content: 28% by mass)

[0135] SBR (styrene butadiene rubber, SBR#1500, manufactured by Sumitomo Chemical Co., Ltd., styrene content: 23.5% by mass)

[0136] NR (natural rubber, RSS#3)

[0137] <(B) Vulcanization accelerator>

[0138] Sulfenamide-based vulcanization accelerator (N-cyclohexyl-2-benzothiazolesulfenamide, Sanceler CM, manufactured by Sanshin Chemical Industry Co., Ltd.)

[0139] · Thiazole vulcanization accelerators (dibenzothiazyl disulfide, Nocceler DM, Ouchi Shinko Chemical Industrial Co., Ltd.)

[0140] <(C) N-phenyl-N-(trichloromethylthio)benzenesulfonamide>

[0141] Vulkalent E / C, Lanxess KK

[0142] <(D) Sulfur>

[0143] Insoluble sulfur (Sanfel, manufactured by Sanshin Chemical Industry Co., Ltd.)

[0144] ·Soluble sulfur (GOLDEN FLOWER sulfur powder, manufactured by Tsurumi Chemical Industry Co., Ltd.)

[0145] <Filling agent>

[0146] Carbon black (Seast S, manufactured by Tokai Carbon Co., Ltd., nitrogen adsorption specific surface area: 27m 2 / g, iodine adsorption: 26mg / g, DBP absorption: 68mL / 100g)

[0147] Calcium carbonate (manufactured by Hakuenka CC, Shiraishi Calcium Kaisha, Ltd.)

[0148] <Plasticizer>

[0149] ·Ether ester oil (ADK Cizer RS-107, manufactured by ADEKA Corporation)

[0150] · Aroma oil (Diana Process AC-12, manufactured by Idemitsu Showa Shell KK)

[0151] ·Parallane oil (Diana Process NM-280, manufactured by Idemitsu Kosan Co., Ltd.)

[0152] <Antiaging agent>

[0153] ·Aniline antioxidant (2,2,4-trimethyl-1,2-dihydroquinoline, NONFLEX RD, manufactured by Seiko Chemical Co., Ltd.)

[0154] <Processing aids>

[0155] ·Stearic acid (LUNAC S-70V, manufactured by Kao Corporation)

[0156] Zinc oxide (2 types of zinc oxide, manufactured by Sakai Chemical Industry Co., Ltd.)

[0157] [Examples 1 to 12, Comparative Examples 1 to 5]

[0158] The components shown in Table 1 described later were mixed in the ratios shown in the same table and kneaded with a kneader to prepare unvulcanized rubber compositions. The following properties were evaluated using the obtained rubber compositions of Examples and Comparative Examples. The results are shown in Table 1 described later.

[0159] <<Heat resistance (aging resistance)>>

[0160] The above rubber composition was press-cured at 150°C for 30 minutes to prepare a cylindrical vulcanized rubber sample (diameter 29.0 mm, height 12.5 mm). The vulcanized rubber sample was tested for compression set in accordance with JIS K 6262 at a temperature of 120°C, a test time of 72 hours, and a compression rate of 25%. The sample with a compression set of less than 50% was evaluated as "○ (very good)", and the sample with a compression set of more than 50% was evaluated as "× (poor)".

[0161] Adhesion

[0162] The rubber composition was used to prepare an unvulcanized rubber sheet (100 mm × 100 mm, 2 mm thick). A brass plated wire (0.4 mm in diameter, 300 mm in length) was placed on the rubber sheet. The sheet was press-vulcanized at 150°C for 30 minutes at a surface pressure of 2 MPa to prepare a vulcanized bonding sample (refer to Figure 4 ). The rubber 11 of the vulcanized adhesive sample is clamped with the brass plated wire 12, and the brass plated wire 12 is peeled off along the X direction according to the T-type peeling test of JIS K 6256, and the coverage of the rubber 11 on the surface of the brass plated wire 12 is measured. The higher the coverage, the better the adhesion between the rubber and the brass plated wire. It should be noted that as the above-mentioned brass plated wire, a brass plated wire (electroplating layer, plating composition: Cu / Zn=65 / 35 mass%, plating adhesion: 4g / kg) manufactured by Tokusen Kogyo Co., Ltd. was used.

[0163] Then, the wires having a rubber coverage of 80% or more were evaluated as "○ (very good)", and the wires having a rubber coverage of less than 80% were evaluated as "× (poor)".

[0164] [Table 1]

[0165]

[0166] From the results in Table 1, it can be seen that the rubber composition according to the examples of the present invention has excellent heat resistance, a high coverage of the rubber on the surface of the plated electric wire, and excellent adhesion between the rubber and the plated electric wire.

[0167] In contrast, the rubber compositions of Comparative Examples 1 and 2 have poor adhesion to the plated wire and poor heat resistance because the content of the component (C) is not within the range specified in the present invention. Specifically, in Comparative Example 1, in which the content of the component (C) is less than the range specified in the present invention, the coverage of the rubber on the surface of the plated wire is low, resulting in poor adhesion between the rubber and the plated wire and poor heat resistance. In Comparative Example 2, in which the content of the component (C) is greater than the range specified in the present invention, the adhesion between the rubber and the plated wire is poor. The rubber compositions of Comparative Examples 3 and 4 have poor adhesion and poor heat resistance because the content of the component (D) is not within the range specified in the present invention. Specifically, in Comparative Example 3, in which the content of the component (D) is less than the range specified in the present invention, the adhesion between the rubber and the plated wire is poor, and in Comparative Example 4, in which the content of the component (D) is greater than the range specified in the present invention, the heat resistance is poor.

[0168] The rubber composition of Comparative Example 5 had poor adhesion between the rubber and the plated electric wire because the content ratio of the component (C) to the component (B) was not within the range defined in the present invention.

[0169] 《Peak intensity of sulfur measured by energy dispersive X-ray spectroscopy (EDX)》

[0170] In the samples used in the above-mentioned adhesive evaluation, the peak intensity of sulfur element measured by energy dispersive X-ray spectroscopy (EDX) at the site within the range of 50 μm from the contact surface with the above-mentioned brass plated electric wire and the peak intensity of sulfur element measured at the site outside the above-mentioned range in the above-mentioned rubber were measured under the following conditions. As a result, it was confirmed that in the samples of Examples 1 to 12, the peak intensity of sulfur element at the site within the range of 50 μm from the contact surface with the above-mentioned brass plated electric wire was high.

[0171] [Energy dispersive X-ray spectroscopy (EDX) measurement conditions]

[0172] ·Cross-section processing: ion cutting method

[0173] ·Analysis and measurement conditions

[0174] Device name: Scanning electron microscope S-4800 (manufactured by Hitachi High-Tech Corporation)

[0175] Energy dispersive X-ray microscope X-Max (manufactured by HORIBA, Ltd.)

[0176] Image type: reflected electron image

[0177] Accelerating voltage: 15 kV

[0178] Conductive treatment: C evaporation

[0179] Magnification:×100k

[0180] Element type: Sulfur

[0181] The above embodiments show specific aspects of the present invention, but the above embodiments are merely examples and are not to be construed as limiting. Various modifications that are obvious to those skilled in the art are intended to be within the scope of the present invention.

[0182] Industrial Applicability

[0183] The industrial hose of the present invention is useful as an industrial hose having a reinforcement layer formed of a plated wire, such as a high-pressure hydraulic hose for construction machinery (construction machinery), mining (excavation) machinery, industrial vehicles (forklifts, unmanned guided vehicles, etc.), and an oil hose for automobiles.

[0184] Description of Reference Numerals

[0185] 1···Inner surface rubber layer

[0186] 2, 2a, 2b...Middle rubber layer

[0187] 3, 13a, 13b... Strengthening layer

[0188] 4···Outer surface rubber layer.

Claims

1. An industrial hose comprising: a rubber layer formed of a rubber composition and a reinforcing layer formed of a plated electric wire in contact with the rubber layer, the rubber composition comprising the following components (A) to (D), wherein the content of component (C) is 0.5 to 1.0 parts by mass and the content of component (D) is 1.0 to 3.0 parts by mass per 100 parts by mass of component (A), the mass ratio of component (C) to component (B) [(C) / (B)] is 0.5 to 1.0, and the mass ratio of component (D) to the total amount of components (B) to (D) [(D) / {(B)+(C)+(D)}] is 0.3 to 0.6, (A) diene rubber, (B) at least one of a sulfenamide vulcanization accelerator and a thiazole vulcanization accelerator, (C) N-phenyl-N-(trichloromethylthio)benzenesulfonamide, (D) Sulfur.

2. The industrial hose according to claim 1, wherein: The peak intensity of sulfur measured by energy dispersive X-ray spectroscopy (EDX) at a portion of the rubber layer within a range of 50 μm from the contact surface with the reinforcing layer is higher than the peak intensity of sulfur measured at a portion of the rubber layer outside the range.

3. The industrial hose according to claim 1 or 2, wherein: The (A) diene rubber is at least one selected from the group consisting of acrylonitrile butadiene rubber, butadiene rubber, styrene butadiene rubber and natural rubber.

4. The industrial hose according to claim 1 or 2, wherein: The rubber composition does not contain one or more adhesives selected from the group consisting of cobalt-based adhesives, melamine-based adhesives, and resorcinol-based adhesives.

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