Industrial hose

Abstract

Provided is an industrial hose in which high interlayer adhesion can be exhibited between the wire reinforcement layer and the rubber layer without impairing the physical properties of the rubber layer and without using an adhesive. An industrial hose in which the layer of at least one of an inner surface rubber layer (1) and an outer surface rubber layer (3) is formed of a vulcanizate of a diene rubber composition containing the following components (A) to (C) and the proportion of the component (B) is 5 to 30 parts by mass relative to 100 parts by mass of the component (A), and the wire reinforcement layer (2) is formed of a wire containing copper. (A) Diene rubber. (B) Calcium carbonate having a BET specific surface area of 4.8 m 2 / g or more. (C) Sulfur.

Description

Technical Field

[0001] This invention relates to industrial hoses used in construction machinery, mining machinery, automotive oil hoses, and various high-pressure hoses with metal wire reinforcement layers. Background Technology

[0002] Industrial hoses, such as high-pressure hydraulic hoses used in construction machinery and mining machinery, are usually reinforced with metal wires to withstand high internal pressure.

[0003] For example, the layer structure of the aforementioned high-pressure hydraulic hose may include: a layer with a metal wire reinforcement layer between the inner and outer layers that are rubber layers; or a layer structure in which multiple intermediate rubber layers and metal wire reinforcement layers are alternately stacked between the inner and outer layers, and the metal wire reinforcement layer is embedded in the intermediate rubber layers.

[0004] Among the metal wires constituting the aforementioned metal wire reinforcement layer, plated metal wires are typically used to improve rust resistance.

[0005] Furthermore, to improve the durability of the hose, the metal wire reinforcement layer, which is made of braided metal wire as described above, must be firmly bonded to the rubber layer to which it is attached. This is because if the adhesion between the metal wire reinforcement layer and the rubber layer is poor, the metal wires will shift or loosen, thus adversely affecting durability.

[0006] As mentioned above, adhesives are typically used to firmly bond the metal wire reinforcement layer to the rubber layer, but this method has problems such as complicated manufacturing processes.

[0007] In order to obtain adhesion (peel durability) to the aforementioned metal wire reinforcing layer without using an adhesive (adhesive-free), for example, the following method is used: the aforementioned metal wire reinforcing layer is formed from copper-containing metal wires such as those plated with brass (copper-zinc alloy), and a diene-based rubber composition is used as the aforementioned rubber layer material. By utilizing the chemical bonding between sulfur, which is a vulcanizing agent in the rubber layer material, and copper ions (Cu) in the metal wire reinforcing layer, a copper sulfide-containing layer is formed in the rubber layer near the interface with the metal wire reinforcing layer, thereby demonstrating the adhesion between the metal wire reinforcing layer and the rubber layer.

[0008] However, during the vulcanization reaction of the aforementioned rubber layer, copper ions from the metal wire reinforcement layer diffuse throughout the entire rubber layer, resulting in a decrease in the concentration of copper ions in the rubber layer near the interface with the metal wire reinforcement layer. As a result, issues such as insufficient adhesion (peel durability) may arise.

[0009] Therefore, in order to obtain good interlayer adhesion, various methods have been studied, such as adding phenolic resin, maleic anhydride modified polymer, etc. to the aforementioned rubber layer material; or adding inorganic water-retaining materials such as silica; or modifying the vulcanization accelerator in the aforementioned rubber layer material (for example, see Patent Documents 1 to 4).

[0010] Existing technical documents

[0011] Patent documents

[0012] Patent Document 1: Japanese Patent Application Publication No. 58-72436

[0013] Patent Document 2: Japanese Patent Application Publication No. 2010-254876

[0014] Patent Document 3: Japanese Patent Application Publication No. 2014-152311

[0015] Patent Document 4: International Publication No. 2014 / 175186 Summary of the Invention

[0016] The problem the invention aims to solve

[0017] However, the existing methods described in the aforementioned patent documents have generated a number of problems, such as excessive increase in rubber hardness leading to a decrease in fatigue resistance; and adverse effects on workability and product appearance due to increased viscosity.

[0018] Therefore, it is desirable to improve the adhesion of the wire reinforcement layer without compromising the physical properties of the rubber layer by using methods different from existing methods.

[0019] The present invention was made in view of this situation and provides an industrial hose in which high interlayer adhesion can be exhibited between the wire reinforcing layer and the rubber layer of the hose without impairing the physical properties of the rubber layer, and without the use of adhesives.

[0020] Solution for solving the problem

[0021] In order to solve the aforementioned problem, the inventors conducted repeated and in-depth research. During the research process, the inventors further investigated the method described above, in which a copper sulfide layer is formed in the rubber layer near the interface with the metal wire reinforcing layer, thereby demonstrating the adhesion between the metal wire reinforcing layer and the rubber layer.

[0022] In this method, as described above, during the vulcanization reaction of the rubber layer, copper ions (Cu) from the metal wire reinforcement layer diffuse throughout the entire rubber layer. The concentration of copper ions in the portion of the rubber layer near the interface with the metal wire reinforcement layer decreases. As a result, there is a problem that a copper sulfide layer exhibiting sufficient adhesion cannot be formed.

[0023] Therefore, the inventors have studied how to improve the adhesion between the copper sulfide-based metal wire reinforcement layer and the rubber layer by using additives in the rubber layer material to suppress the diffusion of copper ions into the entire rubber layer and keeping copper ions in the rubber layer near the metal wire reinforcement layer.

[0024] To concretize this, the inventors repeated various experiments, and unexpectedly, adding a specific amount of BET to the rubber layer material resulted in a specific surface area of ​​4.8 m². 2 The presence of calcium carbonate at concentrations of 1 / g or higher confirmed that the aforementioned phenomenon was indeed caused, resulting in the formation of a copper sulfide layer exhibiting high adhesion. Furthermore, it was found that, as mentioned above, even with the addition of a specific amount of BET to the rubber layer material, the specific surface area remained at 4.8 m². 2 Calcium carbonate of 6g or more exhibits high interlayer adhesion between itself and the metal wire reinforcing layer without compromising the physical properties of the rubber layer, and no adhesive is required, thus achieving the desired purpose.

[0025] That is, the main point of this invention is the following [1] to [7].

[0026] [1] An industrial hose having a layered structure in which at least one of the inner and outer circumferential surfaces of a tubular rubber layer is laminated with a metal wire reinforcing layer.

[0027] The aforementioned metal wire reinforcement layer is formed from copper-containing metal wires.

[0028] The aforementioned rubber layer is formed from a vulcanizate of a diene-based rubber composition containing (A) to (C) below, and the proportion of (B) is 5 to 30 parts by mass relative to 100 parts by mass of (A).

[0029] (A) Diene-based rubber.

[0030] (B) The specific surface area of ​​BET is 4.8m². 2 Calcium carbonate of / g or more.

[0031] (C) Sulfur.

[0032] [2] According to the industrial hose described in [1], the aforementioned diene rubber (A) is a diene rubber with acrylonitrile butadiene rubber as the main component.

[0033] [3] According to the industrial hose described in [1] or [2], wherein the aforementioned calcium carbonate (B) has a BET specific surface area of ​​5.5 m². 2 Calcium carbonate of / g or more.

[0034] [4] The industrial hose according to any one of [1] to [3], wherein the aforementioned metal wire reinforcing layer is formed of metal wire plated with a copper-zinc alloy.

[0035] [5] The industrial hose according to any one of [1] to [4], wherein the aforementioned rubber layer is formed of a vulcanizate of a diene rubber composition further comprising (D) below.

[0036] (D) Silicon dioxide.

[0037] [6] The industrial hose according to any one of [1] to [5], wherein the aforementioned sulfur (C) is sulfur containing insoluble sulfur.

[0038] [7] The industrial hose according to any one of [1] to [6], wherein at least the outer peripheral surface of the aforementioned rubber layer is laminated with the aforementioned metal wire reinforcing layer.

[0039] The effects of the invention

[0040] The industrial hose of the present invention exhibits high interlayer adhesion between its metal wire reinforcement layer and rubber layer without impairing the physical properties of the rubber layer, and does not require the use of adhesives. Furthermore, the diffusion of copper ions from the metal wire reinforcement layer to the entire rubber layer is suppressed, thereby preventing the deterioration of the rubber layer (copper damage). Attached Figure Description

[0041] Figure 1 This is a schematic diagram illustrating an example of the industrial hose of the present invention.

[0042] Figure 2 This diagram illustrates the peel test used in evaluating the adhesion between rubber and coated metal wire. Detailed Implementation

[0043] Next, embodiments of the present invention will be described in detail. However, the present invention is not limited to these embodiments.

[0044] It should be noted that when “X~Y” (where X and Y are arbitrary numbers) are used in this invention, unless otherwise specified, they simultaneously include the meaning of “X or more and Y or less” as well as the meaning of “preferably greater than X” or “preferably less than Y”.

[0045] In addition, when expressed as "X or above" (where X is any number) or "Y or below" (where Y is any number), it also includes the meaning of "preferably greater than X" or "preferably lower than Y".

[0046] As described above, an industrial hose (hereinafter referred to as "the industrial hose") according to an embodiment of the present invention has a layer structure in which at least one of the inner and outer peripheral surfaces of the tubular rubber layer is laminated with a metal wire reinforcing layer, wherein the metal wire reinforcing layer is formed of a copper-containing metal wire, and the rubber layer is formed of a sulfide of a diene rubber composition, wherein the diene rubber composition contains (A) to (C) as described above, and the proportion of (B) is 5 to 30 parts by mass relative to 100 parts by mass of (A).

[0047] (A) Diene-based rubber.

[0048] (B) The specific surface area of ​​BET is 4.8m². 2 Calcium carbonate of / g or more.

[0049] (C) Sulfur.

[0050] Here, Figure 1 The hose shown has a metal wire reinforcement layer 2 formed on the outer peripheral surface of the inner surface rubber layer 1, and an outer surface rubber layer 3 formed on the outer peripheral surface of the aforementioned metal wire reinforcement layer 2. Therefore, it can be described as a layer structure in which the metal wire reinforcement layer 2 is stacked on the outer peripheral surface of the inner surface rubber layer 1, and the metal wire reinforcement layer 2 is stacked on the inner peripheral surface of the outer surface rubber layer 3.

[0051] In order to Figure 1 The hose shown forms the hose used in this industry, and the aforementioned metal wire reinforcing layer 2 must be made of a copper-containing metal wire. Furthermore, in order to... Figure 1 The hose shown is formed to be a hose for industrial use, and at least one of the inner surface rubber layer 1 and the outer surface rubber layer 3 must be made into a layer formed of a vulcanizate of the aforementioned specific diene rubber composition.

[0052] Furthermore, by making at least the inner surface rubber layer 1 a layer formed of a vulcanizate of the aforementioned specific diene-based rubber composition (i.e., making a layer structure in which the aforementioned wire reinforcement layer 2 is laminated at least on the outer peripheral surface of the rubber layer formed of the aforementioned specific diene-based rubber composition), problems such as the narrowing of the flow path inside the hose due to the collapse of the inner surface rubber layer 1 due to interlayer peeling are eliminated, which is therefore preferable. It should be noted that, from the viewpoint of interlayer adhesion, it is more preferable to also make the outer surface rubber layer 3 a layer formed of a vulcanizate of the aforementioned specific diene-based rubber composition.

[0053] Next, the details of each component in the aforementioned specific diene-based rubber composition will be described below.

[0054] Diene-based rubber (A)

[0055] Examples of diene-based rubbers (A) include natural rubber (NR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), isoprene rubber (IR), and butadiene rubber (BR). These can be used alone or in combination of two or more. Among these, when oil resistance is required, diene-based rubbers with NBR as the main component (NBR comprising 50% or more by mass) are preferred, and NBR alone is more preferable. It should be noted that when abrasion resistance is required, SBR and NR are preferred.

[0056] Furthermore, from the viewpoint of the adhesion of the metal wire reinforcing layer 2, the aforementioned NBR preferably has an acrylonitrile content (AN content) of 10 to 33% by mass, and more preferably an AN content of 10 to 28% by mass. That is, this is because if the AN content is too high, the vulcanization rate will be faster, and the bonding between polymers will be stronger, making it less likely for sulfur to dissolve on the surface. Therefore, there is a concern that the adhesion will be reduced. If the AN content is too low, there is a concern that the initial physical properties will be lower.

[0057] Furthermore, from the viewpoint of the adhesion of the metal wire reinforcing layer 2, the aforementioned SBR preferably has a styrene content of 10-25% by mass, and more preferably has a styrene content of 15-25% by mass. This is because if the styrene content is too high, the vulcanization rate increases, leading to stronger bonds between polymers and making it less likely for sulfur to dissolve on the surface, thus raising concerns about reduced adhesion. Conversely, if the styrene content is too low, there is a concern about lower initial physical properties.

[0058] Calcium Carbonate (B)

[0059] As for the aforementioned calcium carbonate (B), from the viewpoint of the effects of the present invention (such as inhibiting the diffusion of copper ions throughout the rubber layer, keeping copper ions within the rubber layer near the metal wire reinforcing layer 2, thereby improving the adhesion between the copper sulfide-based metal wire reinforcing layer 2 and the rubber layer), as described above, a BET specific surface area of ​​4.8 m² is used. 2 Calcium carbonate with a surface area of ​​ / g or more. From the same perspective, the BET specific surface area of ​​the aforementioned calcium carbonate (B) is preferably 5.5m². 2 / g or more, preferably 10m 2 / g or more. It should be noted that the upper limit of the BET specific surface area of ​​the aforementioned calcium carbonate (B) is typically 55m². 2 / g or less, preferably 40m 2 / g or less, more preferably 30m 2 / g or less. In addition, commercially available products of this type of calcium carbonate (B) include Shiraishi Calcium Kaisha CC, Silver W, and Shiraishi Calcium O (all manufactured by Shiraishi Calcium Kaisha, Ltd.).

[0060] It should be noted that the BET specific surface area of ​​the aforementioned calcium carbonate (B) 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 Micro Data Co., Ltd., 4232-II).

[0061] Relative to 100 parts by weight of the aforementioned diene rubber (A), the content of the aforementioned calcium carbonate (B) is, as described above, in the range of 5 to 30 parts by weight, preferably in the range of 5 to 20 parts by weight, and more preferably in the range of 10 to 20 parts by weight. This is because: if the content of the aforementioned calcium carbonate (B) is too low, the advantageous effects of the present invention as described above cannot be obtained; if the content of the aforementioned calcium carbonate (B) is too high, it hinders the effects of the present invention, and a decrease in initial physical properties, a decrease in heat resistance, and a deterioration in processability can be observed.

[0062] Sulfur (C)

[0063] From the viewpoint of advantageously obtaining an adhesion effect with the wire reinforcing layer 2 based on the effects of the present invention as described above, sulfur containing insoluble sulfur is preferred as the aforementioned sulfur (C).

[0064] Here, insoluble sulfur can be exemplified by polymeric sulfur such as μ-sulfur, π-sulfur, and ω-sulfur. These can be used alone or in combination of two or more. It should be noted that, specifically, examples of such insoluble sulfur include Sanfel (manufactured by Sanshin Chemical Industry Co., Ltd.) and Sanfel EX (manufactured by Sanshin Chemical Industry Co., Ltd.).

[0065] Furthermore, relative to 100 parts by weight of the aforementioned diene rubber (A), the content of the aforementioned insoluble sulfur is preferably in the range of 0.2 to 4.8 parts by weight, more preferably in the range of 0.5 to 4.5 parts by weight.

[0066] It should be noted that, in addition to the aforementioned insoluble sulfur, soluble sulfur can also be used as needed. Thus, by using both insoluble and soluble sulfur, the sulfur that primarily contributes to the adhesion to the metal wire reinforcing layer 2 (insoluble sulfur) and the sulfur that primarily contributes to the vulcanization of the rubber (soluble sulfur) can fully exert their respective functions.

[0067] Here, the aforementioned soluble sulfur can be exemplified by sulfur compounds with cyclic structures, such as α-sulfur, β-sulfur, γ-sulfur, and λ-sulfur. These can be used alone or in combination of two or more. Specifically, examples of such soluble sulfur compounds include SULFAX T-10 (manufactured by Tsurumi Chemical Industry Co., Ltd.), GOLDEN FLOWER micronized sulfur (manufactured by Tsurumi Chemical Industry Co., Ltd.), and powdered sulfur S (manufactured by Hosoi Chemical Industry Co., Ltd.).

[0068] Furthermore, relative to 100 parts by weight of the aforementioned diene rubber (A), the content of the aforementioned soluble sulfur is preferably in the range of 0.2 to 4.8 parts by weight, more preferably in the range of 0.5 to 4.5 parts by weight.

[0069] It should be noted that, in this invention, insoluble sulfur refers to sulfur that is insoluble in carbon disulfide by 90% or more by mass, preferably by 95% or more by mass, and more preferably by 98% or more by mass. Furthermore, soluble sulfur refers to sulfur that is soluble in carbon disulfide by 99.5% or more by mass, preferably by 99.9% or more by mass, and more preferably by 100% by mass.

[0070] Furthermore, the total amount of these sulfur (C) components relative to 100 parts by mass of the aforementioned diene rubber (A) is preferably in the range of 1.0 to 6.0 parts by mass, more preferably in the range of 1.0 to 5.0 parts by mass. That is, this is because, if it is within this range, the effects of the present invention as described above are advantageously obtained, exhibiting high interlayer adhesion and making the vulcanization of the rubber layer, etc., better.

[0071] It should be noted that, in addition to (A) to (C) mentioned above, the aforementioned specific diene rubber composition may also be mixed with any materials such as silica (D), carbon black, zinc oxide, stearic acid, processing aids, vulcanization accelerators, plasticizers, tackifiers, antioxidants, flame retardants, and scorching inhibitors as needed.

[0072] If the aforementioned specific diene-based rubber composition contains silica (D), its affinity with metal wires is improved, which is therefore preferred.

[0073] From the viewpoint of further improving affinity with metal wire, the content of the aforementioned silica (D) relative to 100 parts by weight of the aforementioned diene rubber (A) is preferably in the range of 5 to 15 parts by weight, more preferably in the range of 5 to 10 parts by weight.

[0074] From a strengthening point of view, the content of the aforementioned carbon black relative to 100 parts by weight of the aforementioned diene rubber (A) is preferably in the range of 40 to 150 parts by weight, and more preferably in the range of 60 to 130 parts by weight.

[0075] The aforementioned specific diene rubber composition can be prepared, for example, by appropriately mixing the aforementioned components (A) to (C) and various other materials as required, and then mixing them using a kneader, roller, Banbury mixer, or other mixing machine.

[0076] Here, Figure 1 In the industrial hose shown, at least one of the rubber composition for forming the inner surface rubber layer 1 and the rubber composition for forming the outer surface rubber layer 3 uses the aforementioned specific diene rubber composition, which can be made, for example, as follows.

[0077] That is, firstly, using an extrusion molding machine, the rubber composition for forming the aforementioned inner surface rubber layer 1 is extruded onto a mandrel. Next, copper-containing metal wires are woven into a blade-like or spiral shape, and a metal wire reinforcing layer 2 is formed on the outer peripheral surface of the inner surface rubber layer 1. Then, the rubber composition for forming the outer surface rubber layer 3 is extruded onto the outer peripheral surface of the aforementioned metal wire reinforcing layer 2. Finally, the resulting laminate is vulcanized (steam vulcanization, etc.) under specified conditions (e.g., 140–170°C × 10–60 minutes) to produce the aforementioned... Figure 1 Industrial hoses with a layered structure as shown.

[0078] The copper-containing metal wire used in the aforementioned metal wire reinforcing layer 2 includes, in addition to copper wire, metal wires made of iron or stainless steel plated with copper or plated with brass (copper-zinc alloy). Among these, from the viewpoints of flexibility and strength, metal wire plated with brass is preferred.

[0079] In addition, the diameter of the aforementioned metal wire is typically in the range of 0.15 to 1.00 mm, preferably in the range of 0.20 to 0.80 mm.

[0080] It should be noted that the industrial hoses used in this product are not limited to... Figure 1 The layered structure shown can also be, for example, a structure in which multiple rubber layers formed of the aforementioned specific diene rubber composition and the metal wire reinforcing layer 2 are alternately stacked; and further, in addition to these layered structures, an innermost layer and an outermost layer formed of a material different from the aforementioned specific diene rubber composition are also stacked.

[0081] As mentioned above, when the innermost layer is formed of a material different from the aforementioned specific diene-based rubber composition, rubbers with excellent oil resistance are preferred as the material. Examples include acrylonitrile butadiene rubber (NBR), hydrogenated acrylonitrile butadiene rubber (HNBR), acrylate rubber (ACM), ethylene acrylate rubber (AEM), chlorinated polyethylene (CM), chlorosulfonated polyethylene (CSM), and fluororubber (FKM). These can be used alone or in combination of two or more. Among these, NBR is preferred in terms of oil resistance, strength, and cost.

[0082] In addition, the rubber composition used to form the innermost layer can be appropriately blended with reinforcing materials (such as carbon black), white fillers, plasticizers, stearic acid, zinc oxide, vulcanizing agents, vulcanization accelerators, processing aids, etc., as needed, in addition to rubbers such as NBR.

[0083] Furthermore, as mentioned above, when the outermost layer is formed of a material different from the aforementioned specific diene-based rubber composition, rubbers with excellent weather resistance are preferred as the material. Examples include 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), acrylate rubber (ACM), ethylene-acrylate rubber (AEM), chlorinated polyethylene (CM), and chlorosulfonated polyethylene (CSM). These can be used alone or in combination of two or more. Among these, CR is preferred due to its weather resistance, cost, and oil resistance.

[0084] In addition, the rubber composition used to form the outermost layer can be appropriately blended with reinforcing materials (such as carbon black), white fillers, plasticizers, stearic acid, zinc oxide, acid absorbents (such as highly active magnesium and hydrotalcite), antioxidants, vulcanizing agents, vulcanization accelerators, processing aids, etc., as needed, in addition to rubbers such as CR.

[0085] In this industrial hose, the inner diameter of the hose is typically in the range of 5 to 85 mm, preferably in the range of 6 to 80 mm.

[0086] Furthermore, the thickness of the aforementioned inner surface rubber layer 1 is typically in the range of 0.7 to 4.0 mm, preferably in the range of 1.0 to 3.0 mm. The thickness of the aforementioned outer surface rubber layer 3 is typically in the range of 0.5 to 2.5 mm, preferably in the range of 0.8 to 2.0 mm.

[0087] This industrial hose can be used for high-pressure hydraulic hoses for construction machinery, mining machinery, industrial vehicles (forklifts, unmanned transport vehicles, etc.), and oil hoses for automobiles, as well as various oil transport hoses with metal wire reinforcement layers.

[0088] Example

[0089] Next, the embodiments will be described together with comparative examples. However, the present invention is not limited to these embodiments.

[0090] First, the materials shown below were prepared prior to the examples and comparative examples. It should be noted that the BET specific surface area of ​​calcium carbonate described below was determined according to the determination method described above.

[0091] [NBR]

[0092] Nipol DN302 (AN weight: 27.5% by mass), manufactured by Zeon Corporation

[0093] [SBR]

[0094] #1500 (Styrene content: 23.5% by mass), manufactured by Sumitomo Chemical Co., Ltd.

[0095] [NR]

[0096] RSS#3

[0097] [Calcium carbonate(i)]

[0098] Bai Yanhua CC, Shiraishi Calcium Kaisha, Ltd., BET specific surface area: 26.0 m² 2 / g

[0099] [Calcium carbonate (ii)]

[0100] Silver W, manufactured by Shiraishi Calcium Kaisha, Ltd., BET specific surface area: 5.5m² 2 / g

[0101] [Calcium carbonate (iii)]

[0102] Bai Yanhua O, Shiraishi Calcium Kaisha, Ltd., BET specific surface area: 55m² 2 / g

[0103] [Calcium carbonate (iv)]

[0104] Whiton P-30, manufactured by Shiraishi Calcium Kaisha, Ltd., BET specific surface area: 3.4 m² 2 / g

[0105] [Insoluble sulfur]

[0106] Made by Sanfel, Sanshin Chemical Industry Co., Ltd.

[0107] [Soluble sulfur]

[0108] SULFAX T-10, manufactured by Tsurumi Chemical Industry Co., Ltd.

[0109] Silicon dioxide

[0110] Nipsil VN-3, manufactured by Tosoh Silica Corporation

[0111] [Examples 1-10, Comparative Examples 1-5]

[0112] The components shown in Tables 1 and 2 (described later) were mixed in the proportions shown in the same tables. Then, 5 parts by weight of zinc oxide (two types of zinc oxide, manufactured by Sakai Chemical Industry Co., Ltd.), 1 part by weight of stearic acid (LUNAC S-70V, manufactured by Kao Corporation), 2 parts by weight of antioxidant (2,2,4-trimethyl-1,2-dihydroquinoline polymer), 80 parts by weight of carbon black (Seast SO, manufactured by Tokai Carbon Co., Ltd.), 10 parts by weight of plasticizer, and 2 parts by weight of sulfinamide accelerator (Sanceler CZ, manufactured by Sanshin Chemical Industry Co., Ltd.) were mixed in a 3L kneader to prepare a rubber composition.

[0113] It should be noted that for rubber compositions in which NBR is a polymer, an ether ester plasticizer (ADK CizerRS-107, manufactured by ADEKA Corporation) is used as the aforementioned plasticizer; for rubber compositions in which SBR is a polymer, an aromatic oil (Diana Process AC-12, manufactured by Idemitsu Showa Shell KK) is used as the aforementioned plasticizer; and for rubber compositions in which NR is a polymer, paraffin oil (Diana Process NM-280, manufactured by Idemitsu Kosan Co., Ltd.) is used as the aforementioned plasticizer.

[0114] Next, to evaluate the adhesion between the rubber layer and the metal wire reinforcement layer in the industrial hose, vulcanized adhesion samples with the metal wire were prepared using the aforementioned rubber composition according to the following criteria, and the adhesion was evaluated. The results are shown together with Tables 1 and 2 described below.

[0115] Adhesion

[0116] Using the aforementioned rubber composition, an uncured rubber sheet (100mm × 100mm, 2mm thickness) was prepared, and a plated metal wire (0.4mm diameter, 300mm length) was placed on the rubber sheet. The sheet was then subjected to pressure vulcanization at 2MPa and 150°C for 60 minutes to prepare a vulcanized bonded sample (refer to...). Figure 2 ).

[0117] Then, Figure 2 In the vulcanized adhesive sample shown, rubber 11 and coated metal wire 12 are clamped together. According to the T-type peel test of JIS K 6256, the coated metal wire 12 is peeled off in the direction of arrow X. The adhesion rate of rubber 11 on the surface of coated metal wire 12 is determined by visual measurement.

[0118] It should be noted that the aforementioned plated metal wire 12 is a stainless steel wire that has been plated in any of the following: Cu / Zn (copper / Zn = 65% by mass / 35% by mass brass), Cu (copper plating), or Ni (nickel plating) as described in Tables 1 and 2 below.

[0119] Then, the adhesion rate of the rubber 11 on the surface of the coated metal wire 12 is evaluated according to the following criteria, thereby evaluating the adhesiveness.

[0120] ○ (very good): Adhesion rate is above 80%

[0121] △(good): Adhesion rate is above 50% and below 80%.

[0122] × (poor): Adhesion rate less than 50%

[0123] [Table 1]

[0124] (parts by weight)

[0125]

[0126] [Table 2]

[0127] (parts by weight)

[0128]

[0129] The results in Tables 1 and 2 above confirm that the rubber on the surface of the coated metal wire of the vulcanized adhesive sample of the embodiment has a high adhesion rate, and therefore the adhesion between the rubber and the coated metal wire is excellent.

[0130] in addition, Figure 1In the industrial hose with the layered structure shown, at least one of the inner surface rubber layer 1 and the outer surface rubber layer 3 is formed using the rubber composition used in the examples, and the metal wire used in the metal wire reinforcement layer 2 is the plated metal wire used in the examples. As a result, even without adhesive, a strong bond is achieved between the rubber layer using the rubber composition used in the examples and the metal wire reinforcement layer, demonstrating excellent performance as an industrial hose.

[0131] In contrast, Comparative Example 1 was conducted under the same conditions as Example 2, except that the BET specific surface area of ​​calcium carbonate in the rubber did not meet the requirements of this invention, but the desired adhesion was not obtained. Comparative Examples 2-4 were conducted under the same conditions as Example 2, except that the calcium carbonate content in the rubber did not meet the requirements of this invention, but the desired adhesion was not obtained. Comparative Example 5 was conducted under the same conditions as Examples 1 and 2, except that nickel-plated metal wire was used as the plating wire (i.e., copper-containing metal wire was not used), but the desired adhesion was not obtained.

[0132] This indicates that calcium carbonate in rubber does not function as an adhesive agent. Furthermore, it is known that if the combination of the rubber layer material and the metal wire reinforcing layer material specified in this invention is not satisfied, a layer exhibiting strong adhesion at the interface of the two layers (a copper sulfide layer) cannot be formed, and the desired adhesion cannot be obtained.

[0133] The foregoing embodiments illustrate specific aspects of the present invention, but these embodiments are merely illustrative and not intended to be limiting. Various modifications that will be apparent to those skilled in the art are intended to be within the scope of this invention.

[0134] Industrial availability

[0135] The industrial hose of the present invention can be used for various oil transportation hoses with metal wire reinforcement layers, such as high-pressure hydraulic hoses for construction machinery, mining machinery, industrial vehicles (forklifts, unmanned transport vehicles, etc.) and automotive oil hoses.

[0136] Explanation of reference numerals in the attached figures

[0137] 1. Inner surface rubber layer

[0138] 2. Metal wire reinforcement layer

[0139] 3. Outer surface rubber layer

Claims

1. An industrial hose having a layered structure in which at least one of the inner and outer circumferential surfaces of a tubular rubber layer is laminated with a metal wire reinforcing layer. The metal wire reinforcing layer is formed of copper-containing metal wires. The rubber layer is formed from a sulfide of a diene-based rubber composition containing (A) to (C) below, wherein (B) is in the proportion of 5 to 30 parts by weight relative to 100 parts by weight of (A), and component (C) contains insoluble sulfur. The industrial hose does not use adhesives. (A) Diene-based rubber, (B) The specific surface area of ​​BET is 4.8 m². 2 Calcium carbonate of / g or more (C) Sulfur.

2. The industrial hose according to claim 1, wherein, The diene rubber (A) is a diene rubber with acrylonitrile butadiene rubber as the main component.

3. The industrial hose according to claim 1, wherein, The calcium carbonate (B) has a BET specific surface area of ​​5.5 m². 2 Calcium carbonate of / g or more.

4. The industrial hose according to any one of claims 1 to 3, wherein, The metal wire reinforcing layer is formed from metal wires plated with a copper-zinc alloy.

5. The industrial hose according to any one of claims 1 to 3, wherein, The rubber layer is formed from a vulcanizate of a diene-based rubber composition that also contains (D) as described below. (D) Silicon dioxide.

6. The industrial hose according to any one of claims 1 to 3, wherein, The metal wire reinforcement layer is stacked on at least the outer peripheral surface of the rubber layer.

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