JP5955497B2 - Rubber composition for bonding brass plating wire and hydraulic hose - Google Patents

Description

  The present invention relates to a rubber composition for bonding a brass plating wire for a hose and a hydraulic hose.

  In recent years, hydraulic hoses and the like used for construction machinery and the like have a reinforcing yarn or wire sandwiched between an inner rubber and an outer rubber of the hose as a reinforcing layer with an interlayer rubber (insulation rubber) interposed therebetween. A braided (blade) structure, a rubber hose having a spiral structure in which a reinforcing yarn or a wire is wound in a spiral shape, and the like are used.

  This hydraulic hose is made of a material mainly composed of chloroprene rubber (CR) in consideration of oil resistance and the like, but as a rubber component other than this chloroprene rubber, vulcanized to a rubber component adjusted by solution polymerization. A hydraulic hose to which an accelerator is added has been proposed (see, for example, Patent Documents 1 and 2).

JP 2005-291128 A Japanese Patent Laid-Open No. 2005-291282

  By the way, since it is preferable that the amount of additive added to the rubber component is small in order to exhibit rubber characteristics, further studies have been made to further improve Patent Documents 1 and 2, and as a result, adhesion to a brass-plated wire is achieved. It has been found that a rubber composition having good properties and heat resistance is proposed.

  An object of the present invention is to provide a rubber composition for bonding a brass plating wire for a hose and a hydraulic hose that have good adhesion and heat resistance to the brass plating wire.

The present invention provides the following (1) to ( 4 ).
(1) A rubber composition for bonding a brass plated wire reinforcing layer of a hose,
A diene polymer having a content of at least one selected from an organic acid, a fatty acid salt and an organic acid salt of 1.5% by mass or less, and a thiuram vulcanization accelerator,
The organic acid is one or more of rosin acid, stearic acid, palmitic acid and oleic acid, the organic acid salt is sodium rosinate, and the fatty acid salt is fatty acid potassium soap, oleic acid potassium soap, stearic acid One or more of sodium and ammonium stearate , and the combined content of the organic acid, the fatty acid salt, and the organic acid salt is 1.5 parts by mass with respect to 100 parts by mass of the diene polymer. And
A rubber composition for bonding a brass plating wire, wherein a content of the thiuram vulcanization accelerator is more than 0.1 parts by weight and less than 0.5 parts by weight with respect to 100 parts by weight of the diene polymer. object.
(2) The total content of the organic acid, the fatty acid salt and the organic acid salt contained in the diene polymer is 1.0% by mass or less, as described in (1) above A rubber composition for bonding brass plated wires.
( 3 ) The diene polymer is solution polymerized styrene-butadiene rubber (S-SBR), solution polymerized butadiene rubber (S-BR), isoprene rubber (IR), and ethylene-propylene-diene copolymer rubber (EPDM). The rubber composition for bonding a brass plating wire according to the above (1) or ( 2), wherein at least one selected from the group consisting of:
( 4 ) A rubber layer formed using the rubber composition for bonding a brass plating wire according to any one of (1) to ( 3 ), and a brass plating wire reinforcing layer adjacent to the rubber layer. A hydraulic hose comprising:

  ADVANTAGE OF THE INVENTION According to this invention, the rubber composition and hydraulic hose which can obtain a hose with favorable heat resistance can be provided, maintaining favorable adhesiveness with a brass plating wire. Therefore, the rubber laminate of the present invention is suitably used as an air conditioner hose for automobiles, a power steering hose, a hydraulic hose used for a hydraulic system of construction vehicles, and the like.

FIG. 1 is a partially cutaway perspective view schematically showing the configuration of the hose of the present invention.

  Hereinafter, the present invention will be described in detail. In addition, this invention is not limited by the content described in the following embodiment and an Example. In addition, constituent elements in the embodiments and examples described below include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range. Furthermore, the constituent elements disclosed in the embodiments and examples described below may be appropriately combined or may be appropriately selected and used.

  A rubber composition for a hose interlayer rubber according to an embodiment of the present invention (hereinafter referred to as “the rubber composition of the present invention”) is a rubber composition for bonding a brass plated wire reinforcing layer of a hose, and an organic acid A diene polymer having a content of at least one selected from fatty acid salts or organic acid salts of 1.5% by mass or less, a vulcanization accelerator, and a combination of an organic acid, a fatty acid salt, and an organic acid salt The content is 1.5 parts by mass or less with respect to 100 parts by mass of the diene polymer, and the content of the vulcanization accelerator is 0.1 parts by mass with respect to 100 parts by mass of the diene polymer. More than 1.0 parts by mass. In the present specification, the rubber composition before vulcanization is referred to as an unvulcanized rubber composition, and the rubber composition after vulcanization is referred to as a vulcanized rubber composition.

<Diene polymer>
The diene polymer used in the rubber composition of the present invention contains at least one selected from organic acids, fatty acid salts, or organic acid salts. Organic acids generally include fatty acids. Examples of the organic acid include rosin acid, stearic acid, palmitic acid, and oleic acid. Examples of fatty acid salts include fatty acid potassium soap, oleic acid potassium soap, sodium stearate, ammonium stearate, and the like. Examples of the organic acid salt include sodium rosinate, cobalt naphthenate, cobalt stearate or cobalt trineodecanoate. The organic acid, fatty acid salt, and organic acid salt may be used singly or in combination of two or more.

  As the diene polymer, it is preferable to use a solution polymerization rubber. Examples of the diene polymer include solution polymerized styrene-butadiene rubber (S-SBR), solution polymerized butadiene rubber (S-BR), isoprene rubber (IR), and ethylene-propylene-diene copolymer rubber (EPDM). A rubber component is mentioned and contains these as a main component. You may make it mix these rubber components individually or in mixture of 2 or more types. S-SBR includes, for example, trade name: Toughden 2000R manufactured by Asahi Kasei Chemicals Corporation. Examples of S-BR include trade name: Nipol BR1220 manufactured by Nippon Zeon. As isoprene rubber (IR), there is trade name: Nipol IR2200 manufactured by Nippon Zeon Co., Ltd. EPDM includes, for example, trade name: ESPRENE 505 manufactured by Sumitomo Chemical Co., Ltd.

  The content of at least one selected from organic acids, fatty acid salts, or organic acid salts contained in the diene polymer is 1.5% by mass or less, preferably 1.0% by mass or less. Various physical properties and mixing for hoses required for the rubber composition of the present invention by setting the content of at least one selected from an organic acid, a fatty acid salt, or an organic acid salt to 1.5% by mass or less Workability / rolling workability can be set to an arbitrary ratio.

  The organic acid, fatty acid salt and organic acid salt contained in the rubber composition of the present invention are the organic acid, fatty acid salt and organic acid salt contained in the diene polymer, and the organic acid and fatty acid salt separately added to the rubber composition. The total content of the organic acid salt is 1.5 parts by mass or less with respect to 100 parts by mass of the diene polymer. When the total content of the organic acid, fatty acid salt, and organic acid salt exceeds 1.5 parts by mass with respect to 100 parts by mass of the diene polymer, the organic acid, fatty acid salt, or organic acid in the diene polymer Since the amount of salt added is large, adhesion is inhibited. For this reason, the rubber composition of this invention exhibits adhesiveness by making content which combined the organic acid, fatty-acid salt, and organic acid salt which are contained in a diene polymer into 1.5 mass parts or less. be able to.

  In the rubber composition of the present invention, any one or both of another diene polymer and a polymer other than the diene polymer can be added to the diene polymer as long as the object of the present invention is not impaired. . Other diene polymers or polymers other than diene polymers that can be added are polymer solutions of diene polymers and other diene polymers or polymers other than diene polymers, organic acids, Contains at least one organic acid, fatty acid salt or organic acid salt in an amount of at least one selected from fatty acid salt or organic acid salt within a range of 1.5% by mass or less, preferably 1.0% by mass or less To do. By setting the content of at least one selected from an organic acid, a fatty acid salt or an organic acid salt within the above range, various physical properties and mixing for a hose required for the rubber composition of the present invention, as described above. The ratio can be set arbitrarily according to the workability / rolling workability.

  Examples of other diene polymers and polymers other than diene polymers include natural rubber (NR), emulsion polymerization SBR (E-SBR), acrylonitrile-butadiene rubber (NBR), and chlorinated polyethylene rubber (CM). And chlorosulfonated polyethylene rubber (CSM). Preferably, natural rubber (NR) which is a diene polymer, emulsion polymerization SBR (E-SBR), and acrylonitrile-butadiene rubber (NBR) have high properties for hose required for the rubber composition of the present invention. It is preferable because it can be exhibited in a dimension. One or two or more of these other diene polymers or polymers other than the diene polymer may be used in combination with the diene polymer.

  At this time, even when using other diene polymers or polymers other than diene polymers alone or in combination of two or more, organic acids contained in other diene polymers or polymers other than diene polymers, The content of at least one selected from fatty acid salts or organic acid salts is 1.5% by mass or less, preferably 1.0% by mass or less. In the same manner as described above, the content of at least one selected from organic acids, fatty acid salts, and organic acid salts contained in other diene polymers or polymers other than diene polymers is within the above range. The rubber composition of the invention can exhibit adhesiveness.

  The organic acid, fatty acid salt or organic acid salt may be blended in advance in the diene polymer, and may be added simultaneously with other compounding agents such as a vulcanization accelerator, but is included in the diene polymer. The total content of the organic acid, the fatty acid salt, and the organic acid salt is 1.5 parts by mass or less with respect to 100 parts by mass of the diene polymer, and the organic acid and the fatty acid salt contained in the diene polymer. The combined amount of the organic acid, the fatty acid salt and the organic acid salt to be added is 1.5 parts by mass or less with respect to 100 parts by mass of the diene polymer.

<Vulcanization accelerator>
In the rubber composition of the present invention, the vulcanization accelerator is more than 0.1 parts by mass and 1.0 parts by mass or less with respect to 100 parts by mass of the diene polymer of the present invention. As the vulcanization accelerator, a thiuram vulcanization accelerator or a sulfenamide vulcanization accelerator is preferably used, and a thiuram vulcanization accelerator is particularly preferably used. Specific examples of the thiuram vulcanization accelerator include tetramethylthiuram monosulfide (TS) and tetramethylthiuram disulfide (TT). When a thiuram vulcanization accelerator is used as the vulcanization accelerator, the addition amount of the thiuram vulcanization accelerator is more than 0.1 parts by mass and less than 0.5 parts by mass with respect to 100 parts by mass of the diene polymer. It is preferable to set it to 0.2 parts by mass or more and 0.4 parts by mass or less. The reason why the addition amount of the thiuram vulcanization accelerator is less than 0.5 parts by mass is to add all the vulcanization characteristics, initial adhesiveness and heat resistance with a small addition amount.

  Moreover, the rubber composition of this invention can contain various additives as needed in the range which does not impair the objective of this invention. Examples of additives include fillers, plasticizers, softeners, anti-aging agents, organic activators, antioxidants, antistatic agents, flame retardants, vulcanizing agents, vulcanization accelerators, and vulcanization retarders. And an adhesion aid.

  Examples of the filler include carbon black, silica (white carbon), clay, talc, iron oxide, zinc oxide (ZnO), titanium oxide, barium oxide, magnesium oxide, calcium carbonate, magnesium carbonate, zinc carbonate, barium sulfate and mica. (Mica) and diatomaceous earth. These may be used alone or in combination of two or more. As the carbon black, so-called soft carbon having a large particle size such as FTF grade, GPF grade, SRF grade and the like is preferable from the viewpoint of the ultra-thin sheet rolling processability of the rubber composition of the present invention to be obtained. The silica is not particularly limited, and examples thereof include crystalline silica, precipitated silica, amorphous silica (for example, high-temperature treated silica), fumed silica, calcined silica, precipitated silica, pulverized silica, and fused silica. In particular, silica is known to produce carbon gel (bound rubber) like carbon black, and can be suitably used as necessary. Examples of the clay include wax stone clay, kaolin clay, and calcined clay.

  Examples of the plasticizer include dioctyl phthalate (DOP), dibutyl phthalate (DBP), dioctyl adipate (DOA), isodecyl succinate, diethylene glycol dibenzoate, pentaerythritol ester, butyl oleate, methyl acetylricinoleate, tricresyl phosphate, Examples include trioctyl phosphate, trimellitic acid ester, propylene glycol adipate polyester, butylene glycol adipate polyester, and naphthene oil. These may be used alone or in combination of two or more.

  Specific examples of the softener include aroma oils, naphthenic oils, paraffin oils, petroleum resins, vegetable oils, liquid rubbers, etc., and these may be used alone or in combination of two or more. May be.

  Examples of the antioxidant include N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine (6PPD), N, N′-dinaphthyl-p-phenylenediamine (DNPD), and N-isopropyl. -N'-phenyl-p-phenylenediamine (IPPD), styrenated phenol (SP), 2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD), etc., and these may be used alone. Two or more types may be used in combination.

  Specific examples of the organic activator include stearic acid, oleic acid, lauric acid, and zinc stearate. These may be used alone or in combination of two or more.

  Examples of the antioxidant include butylhydroxytoluene (BHT) and butylhydroxyanisole (BHA).

  Examples of the antistatic agent include quaternary ammonium salts; hydrophilic compounds such as polyglycols and ethylene oxide derivatives.

  Examples of the flame retardant include chloroalkyl phosphate, dimethyl / methylphosphonate, bromine / phosphorus compound, ammonium polyphosphate, neopentyl bromide-polyether, and brominated polyether. Examples of non-halogen flame retardants include aluminum hydroxide, magnesium hydroxide, tricresyl phosphate, and diphenyl cresyl phosphate.

  Examples of the vulcanizing agent include vulcanizing agents such as sulfur-based, organic peroxide-based, metal oxide-based, phenol resin, and quinone dioxime. These may be used alone or in combination of two or more. Examples of sulfur-based vulcanizing agents include organic sulfur-containing compounds such as sulfur, tetramethylthiuram disulfide (TMTD), tetraethylthiuram disulfide (TETD), dipentamethylene thiuram disulfide (DPTT), dimorpholine disulfide, and alkylphenol disulfide. Compounds. Examples of sulfur include powdered sulfur, precipitated sulfur, highly dispersible sulfur, surface-treated sulfur, and insoluble sulfur. Examples of the organic peroxide vulcanizing agent include dicumyl peroxide, benzoyl peroxide, t-butyl hydroperoxide, 2,4-dichlorobenzoyl peroxide, 2,5-dimethyl-2,5-di ( t-butylperoxy) hexane, 2,5-dimethylhexane-2,5-di (peroxylbenzoate). Other vulcanizing agents include, for example, resins such as zinc white, magnesium oxide, lisage, phenol resin, p-quinonedioxime, p-dibenzoylquinonedioxime, poly-p-dinitrosobenzene, and methylenedianiline. Can be mentioned.

  As the Kahashi accelerating aid, general rubber auxiliaries can be used together. For example, zinc white; stearic acid, oleic acid, and Zn salts thereof can be used.

  Examples of the vulcanization retarder include organic acids such as phthalic anhydride, benzoic acid, salicylic acid, acetylsalicylic acid; N-nitrosodiphenylamine, N-nitrosophenyl-β-naphthylamine, N-nitroso-trimethyl-dihydroquinoline. Nitroso compounds such as polymers; Halides such as trichloromelanin; 2-mercaptobenzimidazole, N- (cyclohexylthio) phthalimide (PVI) and the like. These may be used alone or in combination of two or more.

  Adhesion aids are triazine thiol compounds (for example, 2,4,6-trimercapto-1,3,5-triazine, 6-butylamino-2,4-dimercapto-1,3,5-triazine), naphthene Examples include cobalt acid, resorcin, cresol, resorcin-formalin latex, monomethylol melamine, monomethylol urea, and ethylene maleimide.

  Each of the various additives described above may be used alone or in combination of two or more.

<Method for producing rubber composition>
The method for producing the rubber composition of the present invention is not particularly limited, and a conventionally known method can be used. Other than the above-mentioned diene polymer and other diene polymer or diene polymer as necessary. Can be produced by blending the above polymer with the above-mentioned various additives. For example, the diene polymer, if necessary, other diene polymers or polymers other than diene polymers and the above various additives, closed mixers such as Banbury mixers, kneaders, rolls, etc. And a method of producing a rubber composition by kneading using a kneading roll machine, an extruder, a twin screw extruder or the like.

  Thus, the rubber composition of the present invention can provide a rubber composition and a hydraulic hose that can obtain a hose with good heat resistance while maintaining good adhesion to a brass-plated wire.

<Hose>
The hose of the present invention is a hose having a rubber layer formed using the rubber composition of the present invention and a reinforcing layer adjacent to the rubber layer. An example of a preferred embodiment of the hose of the present invention will be described with reference to FIG. FIG. 1 is a perspective view of each hose layer cut away. As shown in FIG. 1, the hydraulic hose 11 has a rubber inner layer 12 as an inner tube, and has a reinforcing layer 13 and a rubber outer layer 14 as an outer tube on the upper layer. The rubber layer (rubber inner layer and rubber outer layer) and the reinforcing layer constituting the hose of the present invention will be described in detail.

<Rubber layer>
The rubber layer is a layer adjacent to the reinforcing layer 13, and the hose of the present invention includes the rubber inner layer 12 and the rubber outer layer 14. In the present invention, at least one of the rubber layers is formed using the rubber composition of the present invention. From the viewpoint of weather resistance of the hose, at least the rubber outer layer 14 is formed of the rubber composition of the present invention. It is preferable to form by using. Thus, by forming a rubber layer using the rubber composition of the present invention, even when a fiber material is used as the reinforcing layer, the adhesiveness with the reinforcing layer 13 is maintained satisfactorily. A hose excellent in storage stability during extrusion and extrudability can be obtained.

  In the present invention, the thickness of the rubber inner layer is preferably, for example, from 0.2 mm to 4.0 mm, and more preferably from 0.5 mm to 2.0 mm. Similarly, the thickness of the rubber outer layer is preferably, for example, 0.2 mm or more and 4.0 mm or less, and more preferably 0.5 mm or more and 2.0 mm or less.

<Reinforcing layer>
The reinforcing layer 13 is a layer provided outside the rubber inner layer 12 as desired from the viewpoint of maintaining strength. In the present invention, the reinforcing layer 13 is formed by braiding a reinforcing material such as a reinforcing yarn or a wire. The reinforcing layer 13 is not particularly limited in its meshing method, and may be formed in a blade shape or a spiral shape, and may be appropriately selected depending on pressure resistance. Further, the reinforcing layer 13 may be formed of a single layer or a plurality of layers. Examples of the reinforcing yarn include polyester fiber, polyamide fiber, aramid fiber, vinylon fiber, rayon fiber, PBO (polyparaphenylene benzobisoxazole) fiber, polyketone fiber, and polyarylate fiber. As a wire, the hard steel wire normally used for a hose is mentioned, for example. Specifically, it is preferable to use a brass-plated wire or a galvanized wire, and more preferably a brass-plated wire, for rust prevention and adhesion imparting.

  The manufacturing method of the hose of the present invention having the rubber layer and the reinforcing layer 13 is not particularly limited, and a conventionally known method can be used. Specifically, after laminating the rubber inner layer 12, the reinforcing layer 13, and the rubber outer layer 14 in this order on the mandrel, the layers are pressed under conditions of, for example, 140 ° C. or higher and 190 ° C. for 30 minutes to 180 minutes. Preferable examples include a method of vulcanization bonding by vulcanization, steam vulcanization, oven vulcanization (hot air vulcanization) or hot water vulcanization.

  Accordingly, the field of use of the hydraulic hose of the present invention is not particularly limited and can be applied to various uses. For example, the hydraulic pressure hose used in automobiles, power steering hoses, hydraulic systems for construction vehicles, etc. It can be suitably used as a hose or the like.

  In the present embodiment, the hydraulic hose is used as the rubber laminate, but the present invention is not limited to this, and can be used in other rubber laminates such as a conveyor belt. .

Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to these.
<1. Preparation of rubber composition>
The raw materials shown below were charged into the closed mixer at the mass ratios shown in Tables 1 and 2, respectively, and the rubber compositions shown in Tables 1 and 2 were obtained. Each component in Examples 1-11 and the addition amount (part by mass) are shown in “Table 1”. Each component in Comparative Examples 1 to 10 and the addition amount (parts by mass) are shown in “Table 2”. Moreover, the amount of organic acid salt in the diene polymer and the amount of organic acid salt in the rubber composition are shown. The compounding amount of the organic acid salt in the diene polymer is shown by mass%, and the compounding amount of the organic acid salt in the rubber composition is shown by parts by mass.

  In Example 5, E-SBR containing rosin acid soap (5.38% by mass) in advance was blended with S-SBR in the ratio shown in Table 1, and the rosin acid soap in the diene polymer was used. A rubber composition containing 0.8% by mass and 0.8 parts by mass of rosin acid soap was obtained. In Example 6, E-SBR containing rosin acid soap (5.38% by mass) in advance was blended with S-SBR in the ratio shown in Table 1, and the rosin acid soap in the diene polymer was used. A rubber composition containing 1.0% by mass and 1.0 part by mass of rosin acid soap was obtained. In Example 7, E-SBR containing rosin acid soap (5.38% by mass) in advance was blended in S-SBR in the ratio shown in Table 1, and the rosin acid soap in the diene polymer was used. The rubber composition contained 1.5% by mass and 1.5 parts by mass of rosin acid soap. In Example 10, E-SBR containing rosin acid soap (5.38% by mass) in advance was blended with S-SBR in the ratio shown in Table 1, and the rosin acid soap in the diene polymer was used. A rubber composition containing 1.5 parts by mass of organic acid salt by adding 1.0 mass% and adding rosin acid Na.

[Raw materials used]
-S-SBR: Toughden 2000R, manufactured by Asahi Kasei Chemicals Corporation-Solution polymerization BR (S-BR): Nipol BR 1220, manufactured by Nippon Zeon Co., Ltd.-EPDM: ESPRENE 505, manufactured by Sumitomo Chemical Co., Ltd.-E-SBR: Nipol 1500 , Nippon Zeon Co., Ltd., sodium rosinate (Na rosinate): Dresinate, HERCULES Co., naphthenic acid cobalt (naphthenic acid Co): 10% cobalt naphthenate, DIC Corporation, cobalt stearate (Co stearate) : Cobalt stearate, manufactured by DIC Corporation ・ Carbon black: HTC # G, manufactured by Nippon Kayaku Carbon Corporation ・ Zinc oxide (ZnO): Three types of zinc oxide, manufactured by Shodo Chemical Co., Ltd. ・ Aroma oil: Diana process oil AH-58, Idemitsu Kosan Co., Ltd.・ Sulfur: Oil-treated sulfur, manufactured by Hosoi Chemical Co., Ltd. ・ Thiuram vulcanization accelerator (TS): Sunseller TS-G, manufactured by Sanshin Chemical Industry Co., Ltd. ・ Thiuram vulcanization accelerator (TT): Sunseller TT- PO, manufactured by Sanshin Chemical Industry Co., Ltd. ・ Vulcanization retarder (PVI): N-cyclohexylthiophthalimide, manufactured by Toray Fine Chemical Co., Ltd.

  A hose-shaped wire adhesion test was performed using each of the obtained rubber compositions. The vulcanization conditions were 30 minutes at 148 ° C.

<2. Evaluation of rubber composition>
Each hose-like wire adhesive obtained as described above was evaluated for unvulcanized characteristics, vulcanized characteristics, initial adhesiveness, and heat resistance.

[Unvulcanized properties]
For the obtained rubber composition, vulcanization of the unvulcanized rubber composition was performed at 148 ° C. using a vulcanization tester in accordance with JIS K6300-2 (How to obtain vulcanization characteristics using a vibration vulcanization tester). The minimum torque (ML) and the maximum torque (MH) were detected from the rheometer curve, and t (95) was obtained. T (95) obtained from the test results was evaluated as follows. The test results are shown in Tables 1 and 2.
○: t (95) is 45 minutes or less x: t (95) is more than 45 minutes

[Vulcanization characteristics]
The obtained rubber composition was vulcanized at a surface pressure of 3.0 MPa for 30 minutes using a press molding machine at 148 ° C. to prepare a vulcanized sheet having a thickness of 2 mm. A JIS3 dumbbell-shaped test piece is punched from this sheet, and a tensile test is conducted according to “JIS K6251-2004” at a pulling speed of 500 mm / min. Tensile strength (TB), elongation at break (EB), tensile stress The 100% modulus (M100) was determined and the vulcanization characteristics were evaluated. The vulcanization characteristics obtained from the test results were evaluated as follows. The test results are shown in Tables 1 and 2. The tensile strength (TB) is judged to be good if it is 10 MPa or more, the elongation at break (EB) is judged to be good if it is 170% or more, and the tensile stress 100% modulus (M100) is It was judged to be good if it was above 7 MPa.
(Tensile strength (TB))
Double circle: 15 MPa or more ○: 10 MPa or more and less than 15 MPa x: Less than 10 MPa (Elongation at cutting (EB))
Double circle: 200% or more ○: 170% or more and less than 200% x: Less than 170% (tensile stress 100% modulus (M100))
Double circle: 10 MPa or more ○: 7 MPa or more and less than 10 MPa x: Less than 7 MPa

[Heat aging resistance]
As a heat aging resistance test, an aging test (120 ° C. × 72 hr) was carried out, and after vulcanized rubber was heated at a specified temperature for a specified time using an aging tester, ΔTB · ΔEB · ΔM100 was measured, and before heat treatment The change in value was determined and the aging property of the vulcanized rubber was examined to evaluate the heat resistance. The heat resistance determined from the test results was evaluated as follows. The test results are shown in Tables 1 and 2. ΔTB is judged to be good if it is −40% or more and −10% or less, 10% or more and 40% or less, and ΔEB is good if it is −50% or more and −30% or less, or 30% or more and 50% or less. It was judged that ΔM100 was good when it was −60% to −30% and 30% to 60%.
(ΔTB)
Double circle: ± 10% or less ○: −40% ≦ ΔTB <−10%, 10% <ΔTB ≦ 40%
X: ΔTB <−40%, 40% <ΔTB
(ΔEB)
Double circle: ± 30% or less ○: −50% ≦ ΔEB <−30%, 30% <ΔEB ≦ 50%
X: ΔEB <−50%, 50% <ΔEB
(ΔM100)
Double circle: ± 30% or less ○: −60% ≦ ΔM100 <−30%, 30% <ΔM100 ≦ 60%
X: ΔM100 <−60%, 60% <ΔM100

[Adhesiveness]
Adhesiveness was evaluated by peel strength and rubber attachment.
(1) Peel strength Each rubber composition obtained was formed into a sheet having a thickness of 2.5 mm by a laboratory roll, combined with a brass plate, and pressure-bonded. However, cellophane paper was placed on the part to be gripped by the chuck when peeling, so as not to bond. Then, using a laboratory press molding machine, pressure vulcanization was performed at 142 ° C. for 95 minutes at a surface pressure of 3.0 MPa to obtain a composite of brass and rubber. The composite was allowed to stand at room temperature for 24 hours, and then cut into a width of 25 mm to obtain a test piece. In accordance with JIS K6256-1999 “90 degree peeling test between metal piece and vulcanized rubber”, using a tensile tester specified in JIS K6256, the obtained test piece was subjected to a tensile speed of 50 mm / min. Then, a peel test was performed between the rubber composition and the brass plate, and the peel strength was measured.
(Peeling force)
Double circle: 100 N / 25 mm or more ○: 80 N / 25 mm or more and less than 100 x: 80 N / 25 mm or less (2) With rubber Peel test was performed in the same manner as above, and peeled according to JIS K6256-1999 Rubber coverage was measured by the percentage of rubber coating on the sample brass plate.

When the peel strength value is 80 N / 25 mm or more and the rubber attachment is 75% or more, it can be said that the adhesiveness is good.
(With rubber)
Double circle: 90% or more ○: 75% or more and less than 90% ×: less than 75%

  The results of the unvulcanized characteristics, vulcanized characteristics, initial adhesiveness and heat resistance were comprehensively determined, and the unvulcanized characteristics, vulcanized characteristics, initial adhesiveness and heat resistance were determined, and comprehensive evaluation was performed.

  As shown in Tables 1 and 2, the rubber compositions of Comparative Examples 1 to 10 are inferior in at least one of unvulcanized physical properties, vulcanized physical properties, initial adhesive properties, and heat resistance. The composition had poor initial adhesion. On the other hand, the rubber compositions of Examples 1 to 11 of the present invention were all excellent in unvulcanized physical properties, vulcanized physical properties, initial adhesive properties, and heat resistance. In particular, for the rubber composition of Example 5, as described above, E-SBR containing rosin acid soap (5.38% by mass) in advance was blended with S-SBR, and the diene polymer contained in the diene polymer. The rosin acid soap content is 0.8% by mass and is blended in a rubber composition containing 0.8 parts by mass of rosin acid soap, but unvulcanized physical properties, vulcanized physical properties, initial adhesiveness, heat resistance Both were good. Further, in Examples 8 and 9 in which 0.5 parts by mass or 1.5 parts by mass of rosin acid Na was added separately, unvulcanized physical properties, vulcanized physical properties, initial adhesiveness, and heat resistance were all good. Therefore, according to the rubber compositions of Examples 1 to 11 of the present invention, it was found that even with the addition of a small amount of vulcanization accelerator, the heat aging property was improved and the wire adhesion was good.

  As described above, according to the rubber composition for bonding a brass plating wire of the present invention, a rubber composition for bonding a brass plating wire with improved heat aging can be provided. Therefore, the rubber composition for bonding a brass plating wire of the present invention can be suitably used for a hydraulic hose or the like.

11 Hydraulic hose 12 Rubber inner layer 13 Reinforcement layer 14 Rubber outer layer

Claims (4)

A rubber composition for bonding a brass plated wire reinforcing layer of a hose,
A diene polymer having a content of at least one selected from an organic acid, a fatty acid salt and an organic acid salt of 1.5% by mass or less, and a thiuram vulcanization accelerator,
The organic acid is one or more of rosin acid, stearic acid, palmitic acid and oleic acid, the organic acid salt is sodium rosinate, and the fatty acid salt is fatty acid potassium soap, oleic acid potassium soap, stearic acid One or more of sodium and ammonium stearate,
The total content of the organic acid, the fatty acid salt, and the organic acid salt is 1.5 parts by mass or less with respect to 100 parts by mass of the diene polymer.
A rubber composition for bonding a brass plating wire, wherein a content of the thiuram vulcanization accelerator is more than 0.1 parts by weight and less than 0.5 parts by weight with respect to 100 parts by weight of the diene polymer. object.   2. The brass-plated wire according to claim 1, wherein the total content of the organic acid, the fatty acid salt, and the organic acid salt contained in the diene polymer is 1.0% by mass or less. Adhesive rubber composition. The diene polymer is mainly composed of at least one selected from solution polymerized styrene-butadiene rubber (S-SBR), solution polymerized butadiene rubber (S-BR), and ethylene-propylene-diene copolymer rubber (EPDM). The rubber composition for bonding a brass plated wire according to claim 1 or 2 , wherein: It has a rubber layer formed using the rubber composition for brass plating wire adhesion according to any one of claims 1 to 3 , and a brass plating wire reinforcement layer adjacent to the rubber layer. Hydraulic hose.

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