Industrial hose

Abstract

Provided is an industrial hose having excellent heat resistance and excellent adhesion between a plating wire layer 4 and an intermediate rubber layer 3. An industrial hose includes a layer structure in which an inner surface rubber layer 1, an organic fiber layer 2, an intermediate rubber layer 3, and a plating wire layer 4 are sequentially stacked, wherein the inner surface rubber layer 1 is formed from a rubber composition containing (A) to (D) components, the total content (B+C) of (B) and (C) components is 0.8 to 2.2 parts by mass with respect to 100 parts by mass of the (A) component, the mass ratio (B / C) of the (B) component to the (C) component is 1.8 to 18, (A) is a rubber component containing acrylonitrile butadiene rubber, (B) is at least one of a sulfenamide-based vulcanization accelerator and a thiazole-based vulcanization accelerator, (C) is a thiuram-based vulcanization accelerator, and (D) is N-phenyl-N-(trichloromethylthio)benzenesulfonamide.

Description

Technical Field

[0001] This invention relates to hoses having a cylindrical flow path for fluid passage, and more particularly to industrial hoses. Specifically, it relates to high-pressure hydraulic hoses for industrial machinery such as construction machinery and mining machinery, as well as various hoses for automobiles. Background Technology

[0002] From the perspective of pressure resistance, industrial hoses used in construction machinery, mining machinery, and other industrial machinery are equipped with reinforcing layers such as coated wire layers. For example, Patent Document 1 discloses an industrial hose comprising a layer structure in which an inner surface rubber layer, an organic fiber layer (reinforcing wire layer), an intermediate rubber layer, a coated wire layer, and an outer surface rubber layer are sequentially stacked to form a cylindrical flow path for the flow of fluids such as working oil.

[0003] For industrial hoses, heat resistance is required to prevent thermal degradation caused by the flow of high-temperature fluids (such as working oil at temperatures above 100°C). Additionally, for industrial hoses, good adhesion between the plated wire layer and the intermediate rubber layer is required to prevent pressure degradation caused by factors such as relaxation of the plated wire layer.

[0004] Existing technical documents Patent documents Patent document 1: Japanese Patent Application Publication No. 2014-185758. Summary of the Invention

[0005] The problem that the invention aims to solve The present invention was made in view of the following circumstances, providing an industrial hose with excellent heat resistance and excellent adhesion between the plated wire layer and the intermediate rubber layer.

[0006] means for solving problems In order to solve the above problems, the inventors of this invention conducted repeated and in-depth research and unexpectedly discovered that by using at least one of sulfenamide-based vulcanization accelerators and thiazole-based vulcanization accelerators, a thiuram-based vulcanization accelerator, and N-phenyl-N-(trichloromethylthio)benzenesulfonamide as the constituent materials of the inner surface rubber layer, and controlling the total content and mass ratio of the above vulcanization accelerators within a specific range, an industrial hose with excellent heat resistance and excellent adhesion between the coated wire layer and the intermediate rubber layer can be obtained.

[0007] That is, the main idea of ​​the present invention is in the following [1] to [8]. [1] An industrial hose comprises a layered structure consisting of an inner surface rubber layer, an organic fiber layer, an intermediate rubber layer, and a wire-plated layer, stacked sequentially. The inner surface rubber layer is formed of a rubber composition containing components (A) to (D), wherein the total content (B+C) of components (B) and (C) is 0.8 to 2.2 parts by mass relative to 100 parts by mass of component (A), and the mass ratio of component (B) to component (C) (B / C) is 1.8 to 18. (A) Rubber components containing acrylonitrile butadiene rubber, (B) At least one of sulfenamide-based vulcanization accelerators and thiazole-based vulcanization accelerators. (C) Thiuram-based vulcanization accelerators, (D) N-phenyl-N-(trichloromethylthio)benzenesulfonamide. [2] According to the industrial hose described in [1], the mass ratio (B / C) of component (B) to component (C) is 2 to 10. [3] The industrial hose according to [1] or [2], wherein the (A) component is a rubber component comprising acrylonitrile butadiene rubber and butadiene rubber. [4] The industrial hose according to any one of [1] to [3], wherein the acrylonitrile content of the acrylonitrile butadiene rubber is 18 to 35%. [5] The industrial hose according to any one of [1] to [4], wherein the rubber composition further contains carbon black, the content of which is 80 to 150 parts by weight relative to 100 parts by weight of component (A). [6] The industrial hose according to any one of [1] to [5], wherein the content of component (D) is 0.3 to 1.0 parts by mass relative to 100 parts by mass of component (A). [7] The industrial hose according to any one of [1] to [6], wherein the thickness of the inner surface rubber layer is 0.6 to 4.0 mm, and the thickness of the intermediate rubber layer is 0.1 to 1.0 mm. [8] The industrial hose according to any one of [1] to [7], wherein the organic fiber layer is a layer woven from threads formed of at least one of polyamide fibers and polyester fibers, and the plated wire layer is a layer woven from brass-plated wire.

[0016] Invention Effects According to the present invention, an industrial hose with excellent heat resistance and excellent adhesion between the plated wire layer and the intermediate rubber layer can be provided. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view showing an example of an industrial hose according to an embodiment of the present invention.

[0018] Figure 2 It is a graph (chart) showing the reaction force (torque)-time curve obtained in the reaction force (torque) evaluation test of the embodiment.

[0019] Figure 3 This is an explanatory diagram (top view) of the test sample used in the adhesion evaluation test of the embodiment.

[0020] Figure 4 This is an explanatory diagram of the test sample used in the adhesion evaluation test of the embodiment. Figure 3 (AA-line sectional view). Detailed Implementation

[0021] Next, embodiments of the present invention will be described in detail. However, the present invention is not limited to these embodiments.

[0022] An industrial hose (hereinafter, sometimes referred to as "this hose") according to one embodiment of the present invention is an industrial hose comprising a layer structure having an inner surface rubber layer, an organic fiber layer, an intermediate rubber layer and a wire-plated layer stacked sequentially, characterized in that the inner surface rubber layer is a rubber layer formed using a rubber composition containing components (A) to (D).

[0023] (A) A rubber component containing acrylonitrile butadiene rubber.

[0024] (B) At least one of sulfenamide-based accelerators and thiazole-based accelerators.

[0025] (C) Thiuram-based vulcanization accelerator.

[0026] (D) N-phenyl-N-(trichloromethylthio)benzenesulfonamide.

[0027] For industrial hoses, heat resistance is an important characteristic from the viewpoint of suppressing thermal degradation of the inner surface rubber layer that forms the flow path for high-temperature fluids. On the other hand, from the viewpoint of suppressing the degradation of pressure resistance caused by the relaxation of the plating line layer, the interlayer adhesion between the plating line layer and the intermediate rubber layer is an important characteristic. It is preferable to have both heat resistance and adhesion.

[0028] From the perspective of heat resistance, for example, the following method is sometimes used: vulcanization is carried out by using a thiuram-based vulcanization accelerator as a vulcanization accelerator, thereby forming a large number of monosulfide bonds and disulfide bonds, inhibiting re-crosslinking during heat aging, thereby improving heat resistance. However, from the perspective of the adhesion between the plated line layer and the intermediate rubber layer, this method cannot satisfy both heat resistance and adhesion.

[0029] On the other hand, when using sulfenamide-based vulcanization accelerators for vulcanization, although the adhesion between the coated line layer and the intermediate rubber layer can be satisfied, the large number of polysulfide bonds formed makes it prone to re-crosslinking during heat aging, which cannot be satisfied from the perspective of heat resistance, and it is impossible to balance heat resistance and adhesion.

[0030] Thus, in industrial hoses, heat resistance and adhesion tend to be contradictory properties, and it is not easy to achieve both.

[0031] In exploring a method that balances heat resistance and adhesion, the inventors of this invention focused on the behavior of the intermediate rubber layer and the inner surface rubber layer during vulcanization to analyze the principle or mechanism of strong adhesion between the plated line layer and the intermediate rubber layer. Starting from this perspective, the inventors conducted repeated and in-depth research and concluded that controlling the expansion characteristics of the inner surface rubber layer during vulcanization to impart a radially outward pressing effect on the inner rubber layer is effective in improving the adhesion between the plated line layer and the intermediate rubber layer.

[0032] In other words, the inventors of this invention, after conducting various studies, speculate that during the vulcanization process in the manufacturing process of an industrial hose comprising a layered structure consisting of an inner surface rubber layer, an organic fiber layer, an intermediate rubber layer, and a coated wire layer, the intermediate rubber layer sags within the organic fiber layer. This phenomenon is a major cause of impaired adhesion between the outer peripheral surface of the intermediate rubber layer and the inner peripheral surface of the coated wire layer. Specifically, for example, during the vulcanization process in the manufacturing process of the industrial hose, in recesses formed on the outer peripheral surface of the organic fiber layer through weaving (recesses having depth in the thickness direction of the organic fiber layer, such as recesses formed between openings in the mesh fabric constituting the organic fiber layer), a portion of the intermediate rubber layer sags radially inward towards the hose (a portion of the intermediate rubber layer flows into the recess). As a result, this causes a partial separation between the outer peripheral surface of the intermediate rubber layer and the inner peripheral surface of the coated wire layer, such as a reduction in the contact area between the outer peripheral surface of the intermediate rubber layer and the inner peripheral surface of the coated wire layer, thus reducing interlayer adhesion.

[0033] Based on this investigation, the inventors of this invention, from the viewpoint of suppressing the phenomenon of the intermediate rubber layer sagging locally into the aforementioned recesses of the organic fiber layer, developed a method to control the expansion characteristics of the inner surface rubber layer during vulcanization, to impart a pressing effect on the inner rubber layer to the radially outward side of the hose, and to further develop a method for forming a large number of monosulfide bonds and disulfide bonds.

[0034] The inventors of this invention have repeatedly conducted various experiments and found that, as with this hose, if the inner surface rubber layer is formed using a rubber composition containing components (A) to (D), and the total content of components (B) and (C) (B+C) is in a specific range of 0.8 to 2.2 parts by mass relative to 100 parts by mass of component (A), and the mass ratio of component (B) to component (C) (B / C) is in a specific range of 1.8 to 18, then the vulcanization rate is moderately suppressed, the expansion of the inner surface rubber layer can be appropriately controlled, and a large number of monosulfide bonds and disulfide bonds can be formed, thus achieving both heat resistance and adhesion.

[0035] The following is a detailed description of each layer that makes up this flexible tube.

[0036] <<Inner Surface Rubber Layer>> The inner surface rubber layer is the innermost layer of this hose, forming a cylindrical flow path for fluid passage. The inner surface rubber layer is formed of a rubber composition. The aforementioned rubber composition (hereinafter, sometimes referred to as the "inner surface rubber composition") contains at least (A) a rubber component comprising acrylonitrile butadiene rubber, (B) at least one of a sulfenamide-based vulcanization accelerator and a thiazole-based vulcanization accelerator, (C) a thiuram-based vulcanization accelerator, and (D) N-phenyl-N-(trichloromethylthio)benzenesulfonamide.

[0037] <(A) Rubber components containing acrylonitrile butadiene rubber> The content of the rubber component containing acrylonitrile butadiene rubber is not limited to the following, but is preferably 30 to 80% by mass relative to the total amount (100% by mass) of the inner surface rubber composition, more preferably 32 to 70% by mass, and even more preferably 35 to 55% by mass.

[0038] (Acrylonitrile butadiene rubber (NBR)) The aforementioned acrylonitrile butadiene rubber (NBR) is a copolymer of acrylonitrile and butadiene, or a hydrogenated copolymer of acrylonitrile and butadiene. They can be used alone or in combination of two or more.

[0039] The acrylonitrile content (AN content) of NBR is not particularly limited, but from the viewpoint of heat resistance and adhesion, it is preferably 18 to 35% by mass, and more preferably 18 to 30% by mass. The above-mentioned AN content can be determined by the Kjeldahl method according to JIS K6451-2:2016.

[0040] From the viewpoint of adhesion, the coefficient of linear expansion of NBR is preferably, for example, 2 to 2.5

[10] -4 / ℃]. The linear expansion coefficient mentioned above is more preferably 2.2~2.5

[10] -4 / ℃], and more preferably 2.3~2.5

[10] -4 [ / ℃]. Furthermore, the aforementioned coefficient of linear expansion is the rate of change of length relative to a unit temperature change, for example, measured within a predetermined temperature range (> glass transition temperature (Tg)) according to JIS K7197:2012.

[0041] The Mooney viscosity of NBR is not particularly limited, but is preferably 40 to 82, more preferably 48 to 80, and even more preferably 50 to 78.

[0042] The Mooney viscosity was measured according to JIS K6300-1:2013, using an L-shaped rotor, under the conditions of a preheating time of 1 minute, a rotor rotation time of 4 minutes, and a test temperature of 100°C.

[0043] The inner surface rubber composition contains a rubber component including NBR as the main component. Specifically, from the viewpoint of oil resistance, the NBR content is preferably 60% by mass or more, more preferably 70 to 100% by mass, relative to the total amount of rubber components contained in the inner surface rubber composition (total 100% by mass).

[0044] In addition, the content of NBR can be appropriately set within the above range, relative to the total amount of rubber components contained in the inner surface rubber composition (total 100% by mass), for example, it can be 80~100% by mass, 85~95% by mass, 88~92% by mass, etc.

[0045] (Other ingredients) The inner surface rubber composition may contain rubber components other than acrylonitrile butadiene rubber (NBR) (hereinafter, sometimes referred to as "other rubber components"). Examples of other rubber components include, but are not limited to, butadiene rubber (BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), etc. They may be used alone or in combination of two or more.

[0046] From the viewpoint of oil resistance and adhesion, the content of other rubber components is, for example, 1 to 20% by mass, relative to the total amount (100% by mass) of rubber component (A) contained in the inner surface rubber composition, such as 4 to 18% by mass, 6 to 15% by mass, 8 to 12% by mass, etc.

[0047] From the viewpoint of appropriately controlling the expansion of the inner surface rubber layer during vulcanization, the coefficient of linear expansion of other rubber components is preferably, for example, 2.0 to 2.5

[10] -4 / ℃]. The linear expansion coefficient is more preferably 2.1~2.5

[10] -4 / ℃], and more preferably 2.2~2.5

[10] -4 [ / ℃]. By keeping the coefficient of linear expansion of other rubber components within the above range, there is a tendency to further improve the adhesion between the intermediate rubber layer and the coated line layer. Furthermore, the above-mentioned coefficient of linear expansion is the rate of change of length with respect to a unit temperature change, and is measured, for example, within a predetermined temperature range (> glass transition temperature (Tg)) according to JIS K7197:2012.

[0048] As other rubber components, butadiene rubber (BR) is preferred. By combining NBR and BR, for example, there is a tendency to allow the inner surface rubber layer to expand appropriately, to further improve the adhesion between the intermediate rubber layer and the coated line layer, and to improve extrusion molding properties and productivity.

[0049] As a BR, various butadiene rubbers that have been used as hose materials in the past can be appropriately used, such as BR with high cis content, BR with low cis content, and BR containing isotactic polybutadiene crystals.

[0050] Furthermore, the microstructure of BR is not particularly limited; for example, a high-cis-butadiene rubber with a cis-1,4 bond content of 90% or more is preferred. The aforementioned cis-1,4 bond content can be 95% or more, or 96% or more.

[0051] Furthermore, the content of the aforementioned cis-1,4 can be used 1 H-NMR, 13 Measurements were performed using C-NMR, FT-IR, and other methods.

[0052] The Mooney viscosity of BR is not particularly limited, but is preferably 30 to 60, more preferably 30 to 55, and even more preferably 30 to 50.

[0053] The Mooney viscosity was measured according to JIS K6300-1:2013, using an L-shaped rotor, under the conditions of a preheating time of 1 minute, a rotor rotation time of 4 minutes, and a test temperature of 100°C.

[0054] From the viewpoint of adhesion and oil resistance, the total content of butadiene rubber (BR) and acrylonitrile butadiene rubber (NBR) (BR+NBR) is preferably 80 to 100% by mass relative to the total amount (100% by mass) of rubber component (A) contained in the inner surface rubber composition. More preferably, it is 85 to 100% by mass.

[0055] In addition, the total content mentioned above can be appropriately set within the above range, for example, it can be 90~100% by mass, 95~100% by mass, or 88~95% by mass, 88~92% by mass, etc.

[0056] From the viewpoint of adhesion and oil resistance, the mass ratio of butadiene rubber (BR) to acrylonitrile butadiene rubber (NBR) (BR / NBR) is preferably 0.01 to 10, more preferably 0.03 to 0.4, and even more preferably 0.05 to 0.25.

[0057] The content of BR relative to the total amount (100% by mass) of rubber component (A) contained in the inner surface rubber composition is, for example, 1 to 30% by mass, or 4 to 20% by mass, 6 to 15% by mass, 8 to 10% by mass, etc.

[0058] <(B) at least one of sulfenamide-based vulcanization accelerators and thiazole-based vulcanization accelerators, and (C) thiuram-based vulcanization accelerators> The inner surface rubber composition contains at least one of (B) a sulfenamide-based vulcanization accelerator and a thiazole-based vulcanization accelerator, and (C) a thiuram-based vulcanization accelerator as vulcanization accelerators. Importantly, the total content of components (B) and (C) (B+C) is 0.8 to 2.2 parts by mass relative to 100 parts by mass of component (A), and the mass ratio of component (B) to component (C) (B / C) is 1.8 to 18.

[0059] ((B) At least one of sulfenamide-based vulcanization accelerators and thiazole-based vulcanization accelerators) Examples of sulfenamide-based vulcanization accelerators include N-oxodiethylene-2-benzothiazole sulfenamide (NOBS), N-cyclohexyl-2-benzothiazole sulfenamide (CBS), N-tert-butyl-2-benzothiazole sulfenamide (BBS), and N,N'-dicyclohexyl-2-benzothiazole sulfenamide. They can be used alone or in combination of two or more.

[0060] Examples of thiazole-based vulcanization accelerators include dibenzothiazole disulfide (MBTS), 2-mercaptobenzothiazole (MBT), sodium 2-mercaptobenzothiazole (NaMBT), and zinc 2-mercaptobenzothiazole (ZnMBT). These can be used alone or in combination of two or more.

[0061] As described above, at least one of a sulfenamide-based vulcanization accelerator and a thiazole-based vulcanization accelerator is used as component (B). That is, as component (B), only a sulfenamide-based vulcanization accelerator may be used, or only a thiazole-based vulcanization accelerator may be used, or both a sulfenamide-based vulcanization accelerator and a thiazole-based vulcanization accelerator may be used.

[0062] From the viewpoint of significantly maximizing the effects of the present invention, a sulfenamide-based vulcanization accelerator is preferred. Specifically, an industrial hose is preferably provided in which the inner surface rubber layer is composed of a rubber composition containing components (A) to (D), component (B) is a sulfenamide-based vulcanization accelerator, the total content of components (B) and (C) (B+C) is 0.8 to 2.2 parts by mass relative to 100 parts by mass of component (A), and the mass ratio of component (B) to component (C) (B / C) is 1.8 to 18.

[0063] In addition, N-cyclohexyl-2-benzothiazole sulfenamide is preferred as a sulfenamide-based sulfidation accelerator.

[0064] (C) Thiuram-based vulcanization accelerator) Examples of thiuram-based curing accelerators include tetrabenzylthiuram disulfide (TBzTD), tetramethylthiuram monosulfide (TMTM), tetramethylthiuram disulfide (TMTD), tetraethylthiuram disulfide (TETD), tetrabutylthiuram disulfide (TBTD), tetra(2-ethylhexyl)thiuram disulfide, bis(pentamethylenethiuram) tetrasulfide (DPTT), and bis(pentamethylenethiuram) hexasulfide. These can be used alone or in combination of two or more. Tetramethylthiuram monosulfide (TMTM) is preferred.

[0065] (Total content of component (B) and component (C)) From the viewpoint of maximizing the effects of the present invention, it is important that the total content (B+C) of components (B) and (C) be controlled within the range of 0.8 to 2.2 parts by mass relative to 100 parts by mass of component (A). When the total content is outside this range, there is a tendency for insufficient expansion of the inner surface rubber layer during vulcanization, making it difficult to balance adhesion and heat resistance.

[0066] The total content of component (B) and component (C) can be appropriately set within the above range. For example, relative to 100 parts by mass of component (A), it can be 1.0 to 2.1 parts by mass or 1.0 to 2.0 parts by mass.

[0067] (The mass ratio of component (B) to component (C)) From the viewpoint of maximizing the effects of the present invention, it is important to control the mass ratio (B / C) of component (B) to component (C) within the range of 1.8 to 18. When the mass ratio is outside this range, there is a tendency for insufficient expansion of the inner surface rubber layer during vulcanization, making it difficult to balance adhesion and heat resistance.

[0068] The mass ratio (B / C) of component (B) to component (C) can be appropriately set within the above range, for example, preferably 2 to 12, more preferably 2 to 10.

[0069] The content of component (B) is preferably 0.4 to 3.0 parts by mass relative to 100 parts by mass of component (A), more preferably 0.6 to 2.5 parts by mass, and even more preferably 0.8 to 2.0 parts by mass.

[0070] Furthermore, the content of component (C) is preferably 0.1 to 1.2 parts by mass relative to 100 parts by mass of component (A), more preferably 0.2 to 0.8 parts by mass, and even more preferably 0.1 to 0.6 parts by mass.

[0071] <(D)N-phenyl-N-(trichloromethylthio)benzenesulfonamide> The inner surface rubber composition contains (D)N-phenyl-N-(trichloromethylthio)benzenesulfonamide. By using component (D) in a specific ratio with components (B) and (C), the vulcanization rate can be moderately suppressed while promoting the expansion of the inner surface rubber layer, and a large number of monothioether bonds and dithioether bonds are formed.

[0072] The content of component (D) is not particularly limited. From the viewpoint of significantly exerting the effect of the present invention, it is preferably 0.3 to 1.0 parts by mass relative to 100 parts by mass of component (A), and more preferably 0.4 to 0.8 parts by mass.

[0073] <Other Ingredients> In the inner surface rubber composition, in addition to the components (A) to (D) above, any materials such as sulfur vulcanizing agents, vulcanization accelerators other than components (B) and (C), fillers, plasticizers, anti-aging agents, vulcanization aids, and tackifying resins may be added as needed without impairing the effects of the present invention.

[0074] (sulfur) Sulfur can be categorized into insoluble sulfur and soluble sulfur. They can be used alone or in combination of two or more. Examples of insoluble sulfur include polymeric forms such as μ-sulfur, π-sulfur, and ω-sulfur. Commercially available products include SANFEL (manufactured by Sanshin Chemical Industry Co., Ltd.) and SANFEL EX (manufactured by Sanshin Chemical Industry Co., Ltd.).

[0075] In addition, soluble sulfur can include, for example, α-sulfur, β-sulfur, γ-sulfur, λ-sulfur, and other sulfurs with cyclic structures. Commercially available products include Kinka Ink Micronized Sulfur (manufactured by Tsurumi Chemical Industry Co., Ltd.) and Powdered Sulfur S (manufactured by Hosoi Chemical Industry Co., Ltd.).

[0076] Furthermore, insoluble sulfur refers to sulfur that is insoluble with respect to carbon disulfide by more than 90% by mass. Conversely, soluble sulfur refers to sulfur that is soluble with respect to carbon disulfide by more than 99.5% by mass.

[0077] Regarding the sulfur content, from the viewpoint of balancing heat resistance and adhesion, for example, it is preferably 0.5 to 2.5 parts by mass relative to 100 parts by mass of component (A), more preferably 0.8 to 2.2 parts by mass, and even more preferably 1 to 1.6 parts by mass. When the sulfur content is too high, there is a tendency for the heat resistance to become insufficient.

[0078] (filler) Examples of fillers include carbon black, silica, and calcium carbonate. They can be used alone or in combination of two or more.

[0079] The content of the filler is not particularly limited, for example, it is 80 to 180 parts by mass relative to 100 parts by mass of component (A).

[0080] Among the fillers mentioned above, carbon black is preferred from the viewpoint of improving durability. Examples of carbon black include various grades such as SAF, ISAF, HAF, MAF, FEF, GPF, SRF, FT, and MT. These can be used alone or in combination of two or more.

[0081] The average particle size of the carbon black is not particularly limited, but is preferably 20-130 nm, more preferably 20-80 nm, and even more preferably 20-70 nm. Furthermore, the average particle size of the carbon black is the number-average particle size, measured by transmission electron microscopy.

[0082] The preferred BET specific surface area of ​​carbon black is 10~150m². 2 / g, more preferably 15~100m 2 / g, more preferably 20~80m 2 / g.

[0083] In addition, the BET specific surface area of ​​carbon black can be determined, 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 adsorbed gas, and the BET specific surface area is measured using a BET specific surface area measuring device (manufactured by Microdata, 4232-II).

[0084] The iodine adsorption capacity of carbon black is preferably 10-150 mg / g, more preferably 10-75 mg / g, and even more preferably 20-65 mg / g. Furthermore, the DBP (dibutyl phthalate) absorption capacity of carbon black is preferably 20-180 mL / 100g, more preferably 20-150 mL / 100g.

[0085] In addition, the iodine adsorption capacity of carbon black was determined according to JIS K6217-1:2008 (Method A), and the DBP adsorption capacity of carbon black was determined according to JIS K6217-4:2017.

[0086] The content of carbon black is not particularly limited, for example, it is 80 to 150 parts by mass relative to 100 parts by mass of component (A). In addition, the content of carbon black can be appropriately set within the above range. From the viewpoint of heat resistance, for example, it is preferred to be 115 to 150 parts by mass, and more preferably 120 to 150 parts by mass.

[0087] (Plasticizer) Examples of plasticizers include ester-based plasticizers, aromatic hydrocarbon oils, and processing oils. They can be used alone or in combination of two or more.

[0088] Examples of ester-based plasticizers include dioctyl phthalate and bis[2-(2-butoxyethoxy)ethyl adipate]. Examples of aromatic hydrocarbon oils include Diana Process AC-12, Diana Process AC-460, Diana Process AH-16 (manufactured by Idemitsu Showa Shell), JSO Aromatic 790 (manufactured by Taiyo Oil Co., Ltd.), Aromax1, and Aromax3 (manufactured by Fuji Kosan Co., Ltd.). Additionally, examples of processing oils include cycloalkanes and paraffinic hydrocarbons.

[0089] The content of plasticizer is not particularly limited, but is, for example, 5 to 20 parts by mass relative to 100 parts by mass of component (A), preferably 5 to 18 parts by mass, and more preferably 8 to 15 parts by mass.

[0090] (Anti-aging agent) Examples of anti-aging agents include carbamate-based anti-aging agents, phenylenediamine-based anti-aging agents, phenolic anti-aging agents, phenylamine-based anti-aging agents, diphenylamine-based anti-aging agents, quinoline-based anti-aging agents, imidazole-based anti-aging agents, and waxes. They can be used alone or in combination of two or more.

[0091] The content of the anti-aging agent is not particularly limited, but is preferably 1 to 8 parts by mass, and more preferably 1.5 to 6 parts by mass, relative to 100 parts by mass of component (A).

[0092] (Vulcanization aids) Examples of vulcanizing aids include zinc oxide, zinc oxide (ZnO), stearic acid, and magnesium oxide. They can be used alone or in combination of two or more.

[0093] The content of the vulcanizing aid is not particularly limited, but is, for example, 1 to 12 parts by mass relative to 100 parts by mass of component (A), preferably 2 to 10 parts by mass, and more preferably 3 to 8 parts by mass.

[0094] <Preparation of Inner Surface Rubber Composition> The inner surface rubber composition can be prepared, for example, by appropriately combining the above-mentioned components (A) to (D) and any of the above-mentioned components as needed, and mixing them using a kneader, roller, Banbury mixer or other mixing machine.

[0095] From the viewpoint of improving the adhesion between the coated line layer and the intermediate rubber layer, the inner surface rubber composition preferably possesses a predetermined reaction force. Specifically, for an uncured sheet-like inner surface rubber composition (cylindrical in shape with a diameter of 29.0 mm and a thickness of 12.5 mm), the torque (T) after 30 minutes is obtained from the reaction force (torque [MPa])-time [s] curve measured under the conditions of 5% compression, 150°C, and 30 minutes. 30 Torque relative to the base value (T) B (Minimum torque) ratio (T) 30 / T B Preferably, the value is 1.1 or higher, more preferably 1.5 or higher, and even more preferably 2 or higher. There is no particular upper limit, but it can be 2.5 or lower, 3.0 or lower, etc.

[0096] <<Organic Fiber Layer>> The organic fiber layer in this hose is located radially outside the inner surface rubber layer and is formed on the outer peripheral surface of the inner surface rubber layer. The organic fiber layer, also known as the underlay reinforcement layer, is a layer between the outer peripheral surface of the inner surface rubber layer and the inner peripheral surface of the intermediate rubber layer (described later).

[0097] The organic fiber layer is formed by threads composed of organic fibers, similar to existing technologies. The organic fibers are not particularly limited, and examples include polyester fibers, polyamide fibers, aramid fibers, vinylon fibers, rayon fibers, PBO (poly(p-phenylenebenzodioxazole)) fibers, polyketone fibers, and polyarylate fibers. From the viewpoint of heat resistance and strength, polyester fibers and polyamide fibers are preferred, and polyamide fibers are more preferred.

[0098] There are no particular limitations on the method for forming the organic fiber layer. For example, in addition to the weaving method of weaving threads made of organic fibers using a weaving machine and the spiral method of winding into a spiral shape using a spiral machine, other methods include winding a strip-shaped sheet (such as a mesh fabric) obtained by weaving threads made of organic fibers into a spiral shape using a winding machine.

[0099] The diameter of the thread made of the aforementioned organic fibers is not particularly limited, but is, for example, 0.2 to 1.5 mm, preferably 0.3 to 1.0 mm.

[0100] The weaving density of the organic fiber layer is not particularly limited, for example, it is 20-100%, preferably 30-90%, and more preferably 45-80%.

[0101] Furthermore, weaving density refers to the percentage (%) of the area occupied by the thread made of organic fibers relative to the area of ​​the organic fiber layer. The weaving density is 100% when the gaps between the threads are zero. Specifically, it can be calculated, for example, by the following formula.

[0102] (Formula) Line width (diameter) [mm] × number of lines / (2 × π × outer diameter of inner surface rubber layer [mm] × cosθ [rad]) × 100 (where θ is the weaving angle of the line).

[0103] <<Intermediate Rubber Layer>> The intermediate rubber layer is located radially outside the organic fiber layer in this hose and is formed on the outer peripheral surface of the organic fiber layer. The intermediate rubber layer is a layer between the outer peripheral surface of the organic fiber layer and the inner peripheral surface of the wire-plated layer, which will be described later.

[0104] The intermediate rubber layer is formed from a rubber composition (hereinafter sometimes referred to as "intermediate rubber composition"). The intermediate rubber composition is the same as in the prior art and is not particularly limited, and can be prepared appropriately. The intermediate rubber composition may contain, for example, rubber components, phenolic resins, vulcanization accelerators, vulcanizing agents such as sulfur, fillers, plasticizers, anti-aging agents, vulcanization aids, etc.

[0105] Examples of the aforementioned rubber components include, for example, natural rubber (NR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), isoprene rubber (IR), butadiene rubber (BR), and ethylene propylene diene rubber (EPDM). These components can be used individually or in combination of two or more. Among these, NBR is preferred when oil resistance is required, while SBR and NR are preferred when abrasion resistance is required.

[0106] When NBR is included as a rubber component, the acrylonitrile content (AN content) of NBR is not particularly limited, and can be, for example, less than 33% by mass, less than 28% by mass, or 18 to 25% by mass.

[0107] The content of the above-mentioned rubber component is not limited to the following, for example, it is preferably 30 to 80% by mass relative to the total amount (100% by mass) of the intermediate rubber composition, more preferably 32 to 70% by mass, and even more preferably 35 to 55% by mass.

[0108] As for the aforementioned phenolic resins, any well-known phenolic resins may be used, without particular limitation. Examples include cashew nut shell oil-modified phenolic varnish resins, cashew nut shell oil-modified phenolic resins, and oil-modified phenolic resins. They can be used alone or in combination of two or more.

[0109] The content of phenolic resin relative to 100 parts by weight of the above-mentioned rubber components is preferably 2 to 15 parts by weight, and particularly preferably 2 to 8 parts by weight.

[0110] As the aforementioned vulcanization accelerator, any known vulcanization accelerator can be used, without any particular limitation. Examples include 2-(4′-morpholinodithio)benzothiazole and N-oxadiethylene-2-benzothiazole sulfenamide.

[0111] Intermediate rubber compositions can be prepared by appropriately combining the above-mentioned components and mixing them using a kneader, roller, Banbury mixer, or other mixing machine.

[0112] Furthermore, the intermediate rubber composition may include, for example, cobalt-based adhesives, melamine-based adhesives, and resorcinol-based adhesives. However, from the viewpoint of heat resistance, the content of the aforementioned adhesives relative to the total amount (100% by mass) of the intermediate 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.

[0113] <<Wire Plating Layer>> The wire-coated layer, also known as the wire reinforcement layer, is a layer located radially outside the intermediate rubber layer and formed on the outer peripheral surface of the intermediate rubber layer.

[0114] The wire plating layer is the same as in the prior art and is not particularly limited, and can be formed appropriately. The wire plating layer is a layer formed by the plating wire, and the plating wire is preferably a steel wire to which the plating treatment is performed. In addition, the plating treatment can be exemplified by, for example, copper plating, zinc plating, brass plating (copper-zinc alloy), nickel plating, tin plating, cobalt plating, etc. Among these, brass plating (copper-zinc alloy) is preferred. The copper to zinc content ratio (Cu / Zn) in the brass plating (copper-zinc alloy) is not particularly limited, for example, it is 70 / 30 to 55 / 45, preferably 70 / 30 to 60 / 40.

[0115] The diameter of the plating line is usually 0.15~1mm, preferably 0.2~0.8mm.

[0116] There are no particular limitations on the method for forming the plated line layer, and well-known braiding methods can be listed, such as spiral braiding and other braided methods. Among these, spiral braiding is preferred.

[0117] <<Outer Surface Rubber Layer>> In addition to the layers described above, this hose also has an outer surface rubber layer. This outer surface rubber layer is located radially outside the wire-plated layers and is typically the outermost layer of the hose.

[0118] The outer surface rubber layer is formed from a rubber composition (hereinafter sometimes referred to as the "outer surface rubber composition"). The outer surface rubber composition is the same as in the prior art and is not particularly limited, and can be prepared appropriately. The outer surface rubber composition may contain, for example, rubber components, vulcanization accelerators, vulcanizing agents such as sulfur, fillers, plasticizers, anti-aging agents, vulcanization aids, etc.

[0119] From a weather resistance perspective, the aforementioned rubber components can include, for example, chloroprene rubber (CR), styrene-butadiene rubber (SBR), ethylene-propylene-diene rubber (EPDM), blends of SBR and EPDM, blends of NBR and EPDM, blends of NBR and vinyl chloride (PVC), acrylic rubber (ACM), ethylene acrylate rubber (AEM), chlorinated polyethylene (CM), and chlorosulfonated polyethylene (CSM). These can be used individually or in combination of two or more. Among these, CR is preferred from the perspectives of weather resistance, cost, and oil resistance.

[0120] The content of the above-mentioned rubber component is not limited to the following, for example, it is preferably 30 to 80% by mass relative to the total amount (100% by mass) of the outer surface rubber composition, more preferably 32 to 70% by mass, and even more preferably 35 to 55% by mass.

[0121] The outer surface rubber composition can be prepared by appropriately combining the above-mentioned components and mixing them using a kneader, roller, Banbury mixer, or other mixing machine.

[0122] <<The layered structure of this flexible tube, etc.>> This flexible hose is simply a hose comprising a layered structure consisting of an inner surface rubber layer, an organic fiber layer, an intermediate rubber layer, and a wire-plated layer stacked sequentially. For example, it may also include other intermediate rubber layers, other wire-plated layers, an outer surface rubber layer, and other layers. Specifically, for example, a hose comprising at least a first intermediate rubber layer, a second intermediate rubber layer, a first wire-plated layer, and a second wire-plated layer can be listed. As a preferred embodiment of this flexible hose, an example, but not limited to, a hose composed of a seven-layer structure consisting of "inner surface rubber layer / organic fiber layer / first intermediate rubber layer / first wire-plated layer / second intermediate rubber layer / second wire-plated layer / outer surface rubber layer" can be listed.

[0123] In addition, as an example of a preferred embodiment of this hose, a hose consisting of, but not limited to, a layer structure (nine layers) of “inner surface rubber layer / organic fiber layer / first intermediate rubber layer / first coated wire layer / second intermediate rubber layer / second coated wire layer / third intermediate rubber layer / third coated wire layer / outer surface rubber layer” can be listed.

[0124] Furthermore, as an example of a preferred embodiment of this hose, it can be listed as, but is not limited to, a hose consisting of an eleven-layer structure of “inner surface rubber layer / organic fiber layer / first intermediate rubber layer / first coated wire layer / second intermediate rubber layer / second coated wire layer / third intermediate rubber layer / third coated wire layer / fourth intermediate rubber layer / fourth coated wire layer / outer surface rubber layer”.

[0125] The inner diameter of this hose is not particularly limited, and is usually 5~85mm, preferably 6~80mm. Additionally, the outer diameter of this hose is usually 9~100mm, preferably 10~85mm.

[0126] The thickness of the inner surface rubber layer is not particularly limited, for example, it is 0.6~4.0 mm, preferably 1.0~2.0 mm.

[0127] The thickness of the intermediate rubber layer is, for example, 0.1 to 1.0 mm, preferably 0.2 to 0.6 mm. If the thickness of the intermediate rubber layer is too thick, there is a tendency for bulging to occur, which is not preferred. Furthermore, the aforementioned bulging refers to the following phenomenon: at the root of the connecting metal part of the hose (the end on the side where the hose is inserted), in the balance between the retraction force of the pressed portion of the inner surface rubber layer and the resistance of the unpressed portion, the change in rubber properties caused by heat increases the retraction force. As a result, the inner surface rubber layer peels off from the organic fiber layer, and the peeled portion of the inner surface rubber breaks due to thermal flow.

[0128] The ratio of the thickness of the inner surface rubber layer to the thickness of the intermediate rubber layer (thickness of the inner surface rubber layer / thickness of the intermediate rubber layer) is not particularly limited, but is, for example, 2 to 20, preferably 3 to 12. If the ratio is within the above range, the intermediate rubber layer will not hinder the expansion of the inner surface rubber layer during vulcanization, and the adhesion between the intermediate rubber layer and the plated wire layer can be further improved.

[0129] The thickness of the organic fiber layer is not particularly limited, for example, it is 0.2~1.5 mm, preferably 0.3~0.5 mm.

[0130] The thickness of the wire plating layer is not particularly limited, for example, it is 0.2~1.0mm, preferably 0.3~0.8mm.

[0131] The thickness of the outer surface rubber layer is not particularly limited, for example, it is 0.5~2.5mm, preferably 0.8~2mm.

[0132] Reference Figure 1 One embodiment of this flexible tube will be described. However, the present invention is not limited to this. Figure 1 The structure. Figure 1 This is a schematic cross-sectional view of a hose with a five-layer structure, in which an organic fiber layer 2 is formed on the outer periphery of an inner surface rubber layer 1, an intermediate rubber layer 3 is formed on the outer periphery of an organic fiber layer 2, a coated line layer 4 is formed on the outer periphery of an intermediate rubber layer 3, and an outer surface rubber layer 5 is formed on the outer periphery of a coated line layer 4.

[0133] In this hose, as an embodiment having a layer structure in which the above-mentioned intermediate rubber layer 3 and plated wire layer 4 are alternately repeated, examples can be listed as "inner surface rubber layer 1 / organic fiber layer 2 / intermediate rubber layer 3 / plated wire layer 4 / intermediate rubber layer 3 / plated wire layer 4 / outer surface rubber layer 5", "inner surface rubber layer 1 / organic fiber layer 2 / intermediate rubber layer 3 / plated wire layer 4 / intermediate rubber layer 3 / plated wire layer 4 / intermediate rubber layer 3 / plated wire layer 4 / outer surface rubber layer 5", etc.

[0134] <<Manufacturing Methods>> by Figure 1An example of the manufacturing method of this hose will be described using one embodiment of the present invention. First, using an extrusion molding machine, an inner surface rubber composition is extruded onto a mandrel to form an inner surface rubber layer 1. Next, using a winding machine, a strip made of organic fiber yarn (e.g., yarn made of polyamide fiber) is spirally wound onto the outer periphery of the inner surface rubber layer 1 to form an organic fiber layer 2. Next, an intermediate rubber composition is extruded onto the outer periphery of the organic fiber layer 2 to form an intermediate rubber layer 3. Next, using a brass-plated wire, brass-plated wire is spirally braided onto the outer periphery of the intermediate rubber layer 3 to form a wire-plated layer 4. Next, an outer surface rubber composition is extruded onto the outer periphery of the wire-plated layer 4 to form an outer surface rubber layer 5.

[0135] Next, on the outer periphery of the aforementioned outer surface rubber layer 5, a polyamide canvas is woven into a spiral shape using a braiding machine. After steam vulcanizing the laminate (for example, 150°C for 60 minutes), the polyamide canvas is removed, and a five-layer hose can be produced.

[0136] <<Applications>> This hose is used as a high-pressure hydraulic hose for construction machinery, and various hoses for automobiles (e.g., oil hoses, fuel hoses, air hoses, water hoses, etc.).

[0137] Example Next, the embodiments will be described together with comparative examples. However, the present invention is not limited to these embodiments.

[0138] <<Inner Surface Rubber Layer>> The following materials are prepared as materials for the rubber composition that forms the inner surface rubber layer.

[0139] <(A) Rubber Composition> • NBR1 (Acrylonitrile butadiene rubber, Nipol DN302, manufactured by Zeon Corporation, Japan, AN weight: 28% by mass, Mooney viscosity: 62.5 (mL) 1+4 ,100℃) • NBR2 (Acrylonitrile butadiene rubber, Nipol DN401, manufactured by Zeon Corporation, Japan, AN weight: 18% by mass, Mooney viscosity: 77.5 (mL) 1+4 ,100℃) • NBR3 (Acrylonitrile butadiene rubber, Nipol DN3350, manufactured by Zeon Corporation, Japan, AN content: 33% by mass, Mooney viscosity: 50 (mL) 1+4 ,100℃) BR (Butadiene Rubber, UBEPOL BR-150, manufactured by Ube Industries, Inc., Mooney viscosity: 43 (ml)1+4 ,100℃) <(B) Sulphamide-based vulcanization accelerators, thiazole-based vulcanization accelerators> ·N-Cyclohexyl-2-benzothiazole sulfenamide (Sanceler CM, manufactured by Sanxin Chemical Industry Co., Ltd.) • Dibenzothiazole disulfide (Sanceler DM, manufactured by Sanxin Chemical Industry Co., Ltd.) <(C) Thiuram-based vulcanization accelerators> Tetramethylthiuram monosulfide (Sanceler TS, manufactured by Sanxin Chemical Industry Co., Ltd.) <(D)N-phenyl-N-(trichloromethylthio)benzenesulfonamide> Vulkalent E / C, manufactured by Lanxess. <filler> • Carbon black (SEAST S, manufactured by Tokai Carbon Co., Ltd., nitrogen adsorption specific surface area: 27m²) 2 / g, Iodine adsorption capacity: 26mg / g, DBP absorption capacity: 68mL / 100g) <Vulcanizing Agent> • Sulfur (Jinhua Yinwei powder sulfur, manufactured by Tsurumi Chemical Industry Co., Ltd.) Anti-aging agents • Phenylamine-based anti-aging agent (2,2,4-trimethyl-1,2-dihydroquinoline, NONFLEX RD, manufactured by Seiko Chemical Co., Ltd.) <Plasticizer> • Ester-based plasticizers (dioctyl phthalate (DOP, manufactured by Taoka Chemical Co., Ltd.)) <Processing aids> • Stearic acid (Lunac S-70V, manufactured by Kao Corporation) • Zinc oxide (two types of zinc oxide, manufactured by Sakai Chemical Co., Ltd.) The above-mentioned components were mixed in the proportions shown in Table 1 and kneaded using a kneader to prepare unvulcanized rubber compositions for each inner surface.

[0140] Heat Resistance Evaluation Test Using the inner surface rubber composition obtained above, cylindrical vulcanized rubber specimens (29.0 mm in diameter and 12.5 mm in height) were prepared by pressure vulcanization at 150 °C for 30 minutes. Using these vulcanized rubber specimens, the compression set was measured according to JIS K 6262:2013 at a temperature of 120 °C, a test time of 72 hours, and a compression ratio of 25%, and evaluated according to the following criteria. The results are shown in Table 1.

[0141] (Evaluation Criteria) ◎ (Excellent): Less than 30% 〇 (Good): 30% or more but less than 40% × (poor): more than 40% Evaluation Test of Reaction Force (Torque) Uncured cylindrical rubber sheets (29.0 mm in diameter and 12.5 mm in thickness) were prepared using the inner surface rubber composition obtained above. Under thickness-direction compression (5% compression ratio), a heat treatment was performed at 150°C for 30 minutes, and the reaction force (torque) was measured. The resulting reaction force (torque [MPa])-time curve was obtained (refer to...). Figure 2 The torque (T) after 30 minutes 30 Torque relative to the base value (T) B The ratio of (T) 30 / T B The following criteria are used for evaluation. This ratio is an indicator that the expansion of the inner surface rubber layer within an appropriate range contributes to improved adhesion.

[0142] The results of the above tests indicate that the inner surface rubber composition of Example 2 was rated as "◎" (refer to...). Figure 2 ).

[0143] (Evaluation Criteria) ◎ (Excellent): 1.5 or higher 〇 (Good): 1.1 or higher and less than 1.5 × (difference): less than 1.1 Next, in order to evaluate the adhesion, the following test samples were prepared.

[0144] <<Methods for preparing experimental samples>> Using the above-described inner surface rubber composition, an uncured inner surface rubber sheet 1s (100mm long × 100mm wide, 2.5mm thick) was prepared.

[0145] Using nylon mesh (wire diameter: 0.5mm, thickness: 0.5mm, opening (distance between wires): 1.2mm, opening area (space ratio): 50%), make 2s of nylon mesh (length: 100mm × width: 100mm, thickness: 0.5mm).

[0146] Use the following intermediate rubber composition to produce uncured intermediate rubber sheet 3s (100mm long × 100mm wide, 0.40mm thick).

[0147] (Intermediate rubber composition) An intermediate rubber composition was prepared by mixing 100 parts by weight of NBR (Nipol DN401 manufactured by Zeon Corporation, Japan), 8 parts by weight of phenolic resin (SUMILITERESIN PR-12686 manufactured by Sumitomo Bakelite Corporation), 1 part by weight of thiazole vulcanization accelerator (NOCCELER MDB manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.), 0.5 parts by weight of guanidine vulcanization accelerator (NOCCELER D manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.), 5 parts by weight of zinc oxide (two types of zinc oxide, manufactured by Mitsui Metal Mining Co., Ltd.), 1 part by weight of stearic acid (Lunac S30 manufactured by Kao Corporation), 80 parts by weight of carbon black (SEAST SO manufactured by Tokai Carbon Co., Ltd.), 15 parts by weight of plasticizer (ADK CIZER RS-107 manufactured by ADEKA Corporation), and 2 parts by weight of sulfur (Karuizawa Refining Co., Ltd.) using a kneader according to conventional methods.

[0148] Using brass sheet (CP2801, 0.25mm thick), make brass sheet 4a and brass sheet 4b, which are roughly rectangular when viewed from above (25mm long, 100mm wide, 2.5mm thick).

[0149] The aforementioned nylon mesh 2s is layered on the inner surface rubber sheet 1s, and the intermediate rubber sheet 3s is layered on the nylon mesh 2s. Brass plates 4a and 4b (see reference) are then layered on the intermediate rubber sheet 3s. Figure 3 , Figure 4 ), to prepare test samples. In addition, Figure 4 yes Figure 3 A sectional view along line AA.

[0150] In addition, the above-mentioned test sample is a sample in which a chuck film (90cm long and 30cm wide) is stacked between the intermediate rubber sheet 3s and the brass plates 4a and 4b for the peel test described later (the chuck film is not shown in the figure).

[0151] Adhesion Evaluation Test The test samples were subjected to pressure vulcanization at 2.0 MPa, 150°C, and 30 minutes. The adhesion between the intermediate rubber sheet 3s and the brass plates 4a and 4b was evaluated using the vulcanized test samples.

[0152] Specifically, the clamping film used to hold the intermediate rubber sheet 3s between the brass plates 4a and 4b was subjected to a T-type peel test (peeling speed 50 mm / min) according to JIS K6256-1:2013. The adhesion between the intermediate rubber layer and the plated line layer was evaluated based on the adhesion rate of the intermediate rubber sheet 3s relative to the brass plates 4a and 4b after peeling. Furthermore, a higher adhesion rate indicates better adhesion between the two layers.

[0153] (Evaluation Criteria) ◎ (Excellent): The adhesion rate of the intermediate rubber sheet in the brass plate is over 90%. 〇 (Good): The adhesion rate of the intermediate rubber sheet in the brass plate is less than 90% and more than 80%. × (Poor): The adhesion rate of the intermediate rubber sheet in the brass plate is less than 80%.

[0154] As can be seen from the results in Table 1 above, if the inner surface rubber layer is composed of a rubber composition containing component (A) and components (B) to (D), the total content of components (B+C) is 0.8 to 2.2 parts by mass relative to 100 parts by mass of component (A), and the mass ratio of component (B) to component (C) (B / C) is 1.8 to 18, then the heat resistance is excellent, and the adhesion between the coated wire layer and the intermediate rubber layer is also excellent.

[0155] In contrast, it can be seen that when the rubber composition forming the inner surface rubber layer, as in Comparative Example 1, does not contain component (C), the heat resistance is insufficient. Furthermore, it can be seen that when the rubber composition forming the inner surface rubber layer, as in Comparative Example 2, does not contain component (B), the adhesion is insufficient. Moreover, it can be seen that when the rubber composition forming the inner surface rubber layer, as in Comparative Example 3, does not contain component (D), the heat resistance is insufficient.

[0156] Furthermore, it is known that in cases such as Comparative Example 4, where the rubber composition forming the inner surface rubber layer contains components (B) to (D), but the total content of components (B) and (C) (B+C) is high, the adhesion is insufficient.

[0157] Furthermore, it is known that in rubber compositions that form an inner surface rubber layer, such as Comparative Example 5, although they contain components (B) to (D), the mass ratio (B / C) of component (B) to component (C) is small, resulting in insufficient adhesion.

[0158] Furthermore, it is known that even though the rubber composition forming the inner surface rubber layer contains components (B) to (D), as in Comparative Example 6, the total content of components (B) and (C) (B+C) is high, and the mass ratio of component (B) to component (C) (B / C) is low, the adhesion is also insufficient.

[0159] <<Hose Making>> First, using an extrusion molding machine, the inner surface rubber composition described in the above embodiment is extruded onto a mandrel to form an inner surface rubber layer. Next, using a winding machine, a strip of fabric woven from organic fibers (e.g., the aforementioned nylon mesh) is wound into a spiral shape on the outer periphery of the inner surface rubber layer to form an organic fiber layer. Next, the intermediate rubber composition used in the above experiment is extruded onto the outer periphery of the organic fiber layer to form an intermediate rubber layer. Next, brass-plated wire (0.4 mm in diameter) is woven into a spiral shape on the outer periphery of the intermediate rubber layer to form a plated wire layer. This operation is repeated to form an inner surface rubber layer / organic fiber layer / intermediate rubber layer / plated wire layer / intermediate rubber layer / plated wire layer / intermediate rubber layer / plated wire layer. Then, the following outer surface rubber composition is extruded onto the outer periphery of the plated wire layer to form an outer surface rubber layer. Further, a polyamide canvas is spirally wound onto the outer periphery of the outer surface rubber layer. Finally, after steam vulcanizing the laminate at 150°C for 60 minutes, the polyamide canvas was removed to produce an eleven-layer high-pressure hydraulic hose (inner diameter: 19mm).

[0160] (Outer surface rubber composition) The following ingredients were added: 100 parts by weight of CR (DENKA CHLOROPRENE M-40, non-sulfur modified type, manufactured by Denka Kagaku Kogyo Co., Ltd.), 50 parts by weight of carbon black (SEAST SO, manufactured by Tokai Carbon Co., Ltd.), 25 parts by weight of calcium carbonate (Whiton SB, manufactured by White Stone Calcium Co., Ltd.), 20 parts by weight of plasticizer (rapeseed oil, manufactured by Ajinomoto Co., Ltd.), 1 part by weight of stearic acid (LUNAC S30, manufactured by Kao Corporation), 10 parts by weight of zinc oxide (two types of zinc oxide, manufactured by Mitsui Metals Co., Ltd.), 5 parts by weight of acid acceptor (Kyowa Mag#150, manufactured by Kyowa Chemical Co., Ltd.), and acid acceptor [Mg... 4.5 Al2(OH) 13The mixture is prepared by kneading together 5 parts by weight of CO3·3.5H2O (manufactured by Kyowa Chemical Industry Co., Ltd., DHT-4A), 1 part by weight of anti-aging agent (manufactured by Seiko Chemical Co., Ltd., OZONONE 3C), 0.5 parts by weight of vulcanizing agent (manufactured by Sanshin Chemical Industry Co., Ltd., Sanceler 22C), 0.5 parts by weight of vulcanizing agent (manufactured by Ouchi Shinshin Chemical Industry Co., Ltd., NOCRAC MB), and 0.5 parts by weight of vulcanization accelerator (manufactured by Sanshin Chemical Industry Co., Ltd., Sanceler TT).

[0161] In addition, as a brass-plated wire, we use brass-plated wire manufactured by TOKUSEN (electroplated, plating composition: Cu / Zn = 65 / 35 by mass, plating amount: 4 g / kg).

[0162] Furthermore, while nylon mesh is used as the organic fiber layer in the above description, it is not a limitation. The type of organic fiber, the opening area (space ratio), and other values ​​can be appropriately selected. For example, the opening area (space ratio) of the organic fiber layer is preferably 30-90%, more preferably 40-80%, and even more preferably 40-70%.

[0163] Furthermore, the opening area (%) is a standard value used in this technical field, via "OP". 2 / (OP + wire diameter) 2 To calculate (OP = distance between lines).

[0164] The above embodiments illustrate specific aspects of the present invention, but these embodiments are merely examples and not intended to be limiting. Various modifications that will be apparent to those skilled in the art are within the scope of the present invention.

[0165] Industrial applicability The industrial hose of the present invention is useful as a high-pressure hydraulic hose for construction machinery, mining machinery, industrial vehicles (forklifts, unmanned transport vehicles, etc.), and engine oil hose for automobiles, etc., and has a plated line layer (reinforcing layer).

[0166] Explanation of reference numerals in the attached figures 1: Inner surface rubber layer; 2: Organic fiber layer; 3: Intermediate rubber layer; 4: Plating line layers; 5: Outer surface rubber layer.

Claims

1. An industrial hose, comprising a layered structure consisting of an inner surface rubber layer, an organic fiber layer, an intermediate rubber layer, and a wire-plated layer stacked sequentially, wherein, The inner surface rubber layer is formed of a rubber composition containing components (A) to (D), wherein the total content (B+C) of components (B) and (C) is 0.8 to 2.2 parts by mass relative to 100 parts by mass of component (A), and the mass ratio of component (B) to component (C) (B / C) is 1.8 to 18. (A) Rubber components containing acrylonitrile butadiene rubber, (B) At least one of sulfenamide-based vulcanization accelerators and thiazole-based vulcanization accelerators. (C) Thiuram-based vulcanization accelerators, (D) N-phenyl-N-(trichloromethylthio)benzenesulfonamide.

2. The industrial hose according to claim 1, wherein, The mass ratio (B / C) of component (B) to component (C) is 2 to 10.

3. The industrial hose according to claim 1 or 2, wherein, The component (A) is a rubber component comprising acrylonitrile butadiene rubber and butadiene rubber.

4. The industrial hose according to any one of claims 1 to 3, wherein, The acrylonitrile content of the acrylonitrile butadiene rubber is 18-35%.

5. The industrial hose according to any one of claims 1 to 4, wherein, The rubber composition also contains carbon black, the amount of which is 80 to 150 parts by weight relative to 100 parts by weight of component (A).

6. The industrial hose according to any one of claims 1 to 5, wherein, The content of component (D) is 0.3 to 1.0 parts by mass relative to 100 parts by mass of component (A).

7. The industrial hose according to any one of claims 1 to 6, wherein, The thickness of the inner surface rubber layer is 0.6~4.0mm, and the thickness of the middle rubber layer is 0.1~1.0mm.

8. The industrial hose according to any one of claims 1 to 7, wherein, The organic fiber layer is a layer woven from threads formed of at least one of polyamide fibers and polyester fibers, and the plated wire layer is a layer woven from brass-plated wires.

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