Rubber composition for hose and hose

Abstract

To provide a rubber composition for hoses and the like excellent in oil resistance and low-temperature properties.SOLUTION: The rubber composition for hoses contains a hydrogenated acrylonitrile-butadiene rubber having an acrylonitrile content of 24 mass% or less, carbon black, a peroxide, and triallyl isocyanurate. The content of the peroxide is 2.4 pts.mass or more based on 100 pts.mass of the hydrogenated acrylonitrile-butadiene rubber. The content of the triallyl isocyanurate is 1.9 pts.mass or more based on 100 pts.mass of the hydrogenated acrylonitrile-butadiene rubber. There is also provided a hose formed using the rubber composition for hoses.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a rubber composition for a hose and a hose. [Background technology]

[0002] BACKGROUND ART Conventionally, a rubber composition containing HNBR (hydrogenated acrylonitrile butadiene rubber) has been used as a material for forming the inner pipe of an automotive power steering hose. For example, Patent Document 1 discloses a rubber composition having high heat resistance and high vibration absorbing performance, suitable for use in power steering hoses, etc., which comprises: (1) 90 to 20 parts by weight of a copolymer rubber having, in the polymer chain, 10 to 45% by weight of a unit portion derived from an unsaturated nitrile (Y portion; VCN), 0 to 5% by weight of a unit portion derived from a conjugated diene (Z portion; C=C), and 90 to 50% by weight of a unit portion derived from an ethylenically unsaturated monomer other than the unsaturated nitrile and / or a unit portion derived from a conjugated diene (X portion; CC); (2) 10 to 80 parts by weight of chlorinated polyethylene rubber with a chlorination rate of 25% or more; (3) A rubber composition containing an organic peroxide and characterized in that the loss tangent (tan δ) when subjected to forced extension vibration at 5 Hz is 0.23 or more in a temperature range of 0 to 10°C is described. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-96241 Summary of the Invention [Problem to be solved by the invention]

[0004] The inner pipe of an automotive power steering hose is required to have oil resistance in addition to heat resistance, etc., so the HNBR contained in the rubber composition is a high-nitrile HNBR, such as one containing 34% or 36% acrylonitrile by mass. However, there is a trade-off in that the higher the acrylonitrile content of HNBR, the poorer its ability to exhibit viscoelasticity under low-temperature conditions (hereinafter, this may be referred to as "low-temperature properties").

[0005] Therefore, an object of the present invention is to provide a rubber composition for a hose that has excellent oil resistance and low-temperature properties. Another object of the present invention is to provide a hose that has excellent oil resistance and low-temperature properties. [Means for solving the problem]

[0006] As a result of intensive research to solve the above problems, the present inventors have found that a desired effect can be obtained by a rubber composition containing hydrogenated acrylonitrile-butadiene rubber having an acrylonitrile amount of 24 mass% or less, carbon black, a peroxide, and triallyl isocyanurate, wherein the contents of peroxide and triallyl isocyanurate are each within a specific range, and have arrived at the present invention. The present invention is based on the above findings and solves the above problems by specifically providing the following configurations.

[0007] [1] A rubber composition comprising hydrogenated acrylonitrile butadiene rubber having an acrylonitrile content of 24% by mass or less, carbon black, a peroxide, and triallyl isocyanurate, the content of the peroxide is 2.4 parts by mass or more relative to 100 parts by mass of the hydrogenated acrylonitrile-butadiene rubber, The rubber composition for hoses has a content of the triallyl isocyanurate of 1.9 parts by mass or more based on 100 parts by mass of the hydrogenated acrylonitrile butadiene rubber. [2] The rubber composition for a hose according to [1], wherein the hydrogenated acrylonitrile butadiene rubber has a hydrogenation rate of 95 to 100%. [3] The rubber composition for a hose according to [1] or [2], wherein the content of the carbon black is 40 to 150 parts by mass per 100 parts by mass of the hydrogenated acrylonitrile butadiene rubber. [4] The rubber composition for a hose according to any one of [1] to [3], wherein the amount of acrylonitrile in the hydrogenated acrylonitrile butadiene rubber is 18 to 22% by mass. [5] The rubber composition for a hose according to any one of [1] to [4], wherein the content of the peroxide is 2.8 to 6 parts by mass per 100 parts by mass of the hydrogenated acrylonitrile butadiene rubber. [6] The rubber composition for hoses according to any one of [1] to [5], wherein the content of the triallyl isocyanurate is 2.5 to 5.0 parts by mass per 100 parts by mass of the hydrogenated acrylonitrile butadiene rubber. [7] The rubber composition for a hose according to any one of [1] to [6], further comprising a diallyl compound.

[0008] [8] A hose formed using the rubber composition for a hose according to any one of [1] to [7]. [9] The hose according to [8], which has an inner tube formed using the rubber composition for a hose.

[10] A hose according to [8] or [9], which allows the passage of a fluid having an aniline point of 105°C or higher.

[11] The hose according to any one of [8] to

[10] , which is for use in an automobile.

[12] The hose according to any one of [8] to

[11] , which is a piping for a power steering system of an automobile. [Effects of the Invention]

[0009] The rubber composition for a hose of the present invention has excellent oil resistance and low temperature properties. The hose of the present invention has excellent oil resistance and low-temperature properties. [Brief explanation of the drawings]

[0010] [Figure 1]FIG. 1 is a perspective view showing cutaway layers of a hose according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described in detail below. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. In this specification, unless otherwise specified, each component may be used alone or in combination of two or more substances. When a component contains two or more substances, the content of the component means the total content of the two or more substances. In this specification, when at least one of oil resistance and low temperature property is superior, it may be said that the effect of the present invention is superior.

[0012] [Rubber composition for hoses] The rubber composition for a hose of the present invention (the rubber composition of the present invention) is The rubber composition contains hydrogenated acrylonitrile butadiene rubber having an acrylonitrile content of 24% by mass or less, carbon black, a peroxide, and triallyl isocyanurate, the content of the peroxide is 2.4 parts by mass or more relative to 100 parts by mass of the hydrogenated acrylonitrile-butadiene rubber, The rubber composition for hoses has a content of the triallyl isocyanurate of 1.9 parts by mass or more relative to 100 parts by mass of the hydrogenated acrylonitrile butadiene rubber.

[0013] The rubber composition of the present invention has such a structure, and is therefore believed to achieve the desired effects. The reason for this is not clear, but is presumed to be as follows. That is, by using a peroxide as a crosslinking agent and triallyl isocyanurate as a co-crosslinking agent in specific amounts for low-nitrile HNBR, which has a low acrylonitrile content (AN content), and increasing the crosslink density of the rubber after crosslinking, it is believed that the volume swelling of the rubber due to oil after crosslinking can be prevented (oil resistance) and viscoelasticity can be exhibited at low temperatures (low-temperature resistance). The above mechanism is a conjecture of the inventor, and the mechanism of the present invention is not limited to the above. Each component contained in the rubber composition of the present invention will be described in detail below.

[0014] <<Hydrogenated acrylonitrile butadiene rubber>> The rubber composition of the present invention contains hydrogenated acrylonitrile butadiene rubber (HNBR) having an acrylonitrile amount (AN amount) of 24 mass % or less. The HNBR contained in the rubber composition of the present invention is a hydrogenated copolymer of acrylonitrile and butadiene. The HNBR has an acrylonitrile group. The hydrogenation in the HNBR is hydrogenation in the main chain, and the hydrogenation may be partial or complete.

[0015] <Acrylonitrile content> In the present invention, the amount of acrylonitrile (AN amount) contained in the HNBR is 24 mass % or less in the HNBR.

[0016] The AN amount of the HNBR is preferably 18 to 22 mass % in the HNBR, from the viewpoint of achieving better effects of the present invention. In the present invention, the acrylonitrile content of HNBR can be measured in accordance with the semi-micro Kjeldahl method based on JIS K6384.

[0017] (hydrogenation rate) From the viewpoint of achieving better effects of the present invention, the hydrogenation rate of the HNBR is preferably 95 to 100% of the double bonds (present in repeating units derived from butadiene) that the NBR has before hydrogenation. In the present invention, the hydrogenation rate of HNBR can be measured in accordance with JIS K6235.

[0018] From the viewpoint of achieving superior effects of the present invention, the rubber composition of the present invention preferably contains only the above-mentioned HNBR as the rubber component.

[0019] From the viewpoint of achieving superior effects of the present invention, the rubber composition of the present invention preferably does not substantially contain alloyed HNBR. The rubber composition of the present invention being substantially free of alloyed HNBR means that the amount of alloyed HNBR is 0 to 1.0% by mass of the total amount of the rubber composition of the present invention.

[0020] <Carbon black> In the present invention, the carbon black is not particularly limited. (Nitrogen adsorption specific surface area of ​​carbon black) The nitrogen adsorption specific surface area of ​​the carbon black is preferably 5 to 50 m from the viewpoint of obtaining a more excellent effect of the present invention. 2 / g is preferred. In the present invention, the nitrogen adsorption specific surface area of ​​carbon black can be measured in accordance with JIS K 6217-2:2001.

[0021] (Dibutyl phthalate oil absorption of carbon black) From the viewpoint of achieving a better effect of the present invention, the dibutyl phthalate oil absorption of the carbon black is preferably from 25 to 130 ml / 100 g, and more preferably from 50 to 120 ml / 100 g. The dibutyl phthalate oil absorption of carbon black can be measured in accordance with JIS K 6217-4:2008.

[0022] Examples of carbon black include FTF grade (Fine Thermal Furnace), FEF grade (Fast Extruding Furnace), GPF grade (General Purpose Furnace), and SRF grade (Semi-Reinforcing Furnace) carbon black. The carbon blacks can be used either alone or in combination of two or more.

[0023] The combination of carbon black is preferably a combination of FEF grade and SRF grade carbon black, from the viewpoint of achieving a better effect of the present invention.

[0024] (Carbon black content) The content of carbon black (when two or more types of carbon black are used in combination, the total amount of these) is preferably 40 to 150 parts by mass, more preferably 80 to 120 parts by mass, relative to 100 parts by mass of hydrogenated acrylonitrile butadiene rubber, from the viewpoint of achieving better effects of the present invention.

[0025] <Peroxide> The peroxide contained in the rubber composition of the present invention is not particularly limited as long as it is a peroxide that can abstract protons from HNBR.

[0026] Examples of peroxides include benzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 1,3-bis(t-butylperoxypropyl)benzene, di-t-butylperoxy-diisopropylbenzene, t-butylperoxybenzene, 2,4-dichlorobenzoyl peroxide, and 1,1-dibutylperoxy-3,3,5-trimethylsiloxane.

[0027] The peroxide can function as a crosslinking agent, and from the viewpoint of achieving superior effects of the present invention, it is preferable that the peroxide contains an organic peroxide having multiple peroxy groups, and more preferable that the peroxide contains di-t-butyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 1,3-bis(t-butylperoxypropyl)benzene, or di-t-butylperoxy-diisopropylbenzene.

[0028] <Peroxide content> In the present invention, the content of the peroxide is 2.4 parts by mass or more based on 100 parts by mass of the hydrogenated acrylonitrile butadiene rubber.

[0029] From the viewpoint of achieving better effects of the present invention, the content of the peroxide is preferably 2.8 to 6 parts by mass, more preferably 3.0 to 5.0 parts by mass, relative to 100 parts by mass of the hydrogenated acrylonitrile butadiene rubber.

[0030] <Triallyl isocyanurate> The triallyl isocyanurate contained in the rubber composition of the present invention is a compound having the following structure: Triallyl isocyanurate functions as a co-crosslinking agent and can crosslink HNBR. [ka]

[0031] <Triallyl isocyanurate content> In the present invention, the content of triallyl isocyanurate is 1.9 parts by mass or more based on 100 parts by mass of the hydrogenated acrylonitrile butadiene rubber.

[0032] From the viewpoint of achieving better effects of the present invention, the content of triallyl isocyanurate is preferably 2.5 to 5.0 parts by mass, more preferably 3.0 to 4.0 parts by mass, relative to 100 parts by mass of the hydrogenated acrylonitrile butadiene rubber.

[0033] (diallyl compounds) The rubber composition of the present invention preferably further contains a diallyl compound, from the viewpoint of achieving better effects of the present invention and excellent elongation of the resulting rubber. The diallyl compound is not particularly limited as long as it is a compound having two allyl groups, and examples thereof include aromatic compounds having two allyl groups such as diallyl phthalate. The diallyl compound preferably contains diallyl phthalate, from the viewpoint of achieving better effects of the present invention and excellent elongation of the resulting rubber.

[0034] Diallyl compound content From the viewpoint of achieving better effects of the present invention, the content of the diallyl compound is preferably 3.0 to 20 parts by mass, more preferably 5.0 to 10.0 parts by mass, and even more preferably 7.0 to 10.0 parts by mass, relative to 100 parts by mass of the hydrogenated acrylonitrile-butadiene rubber.

[0035] (additives) The rubber composition of the present invention may further contain additives such as plasticizers, antioxidants, antioxidants, antistatic agents, flame retardants, and adhesion promoters, as long as the object of the present invention is not impaired. The various additives are not particularly limited. For example, conventionally known additives can be used. The content of the various additives is not particularly limited and can be selected appropriately.

[0036] The rubber composition of the present invention may be substantially free of sulfur. The rubber composition of the present invention being substantially free of sulfur means that the amount of sulfur is 0 to 0.5% by mass of the total amount of the rubber composition of the present invention.

[0037] (Manufacturing method, usage, etc.) The rubber composition of the present invention may be produced without any particular limitation, for example, by mixing the above-mentioned HNBR, carbon black, peroxide, triallyl isocyanurate, and optionally a diallyl compound and additives at 40 to 200°C using an internal mixer such as a Banbury mixer or a kneader, or a kneading roll mill.

[0038] The conditions for crosslinking the rubber composition of the present invention are not particularly limited. For example, the rubber composition of the present invention can be crosslinked under pressure at a temperature of 110 to 160°C.

[0039] <Rubber composition for hoses> The rubber composition of the present invention can be used to produce a hose. In particular, one preferred embodiment is to use the rubber composition of the present invention for the inner tube of a hose.

[0040] [hose] The hose of the present invention is a hose formed using the rubber composition for a hose of the present invention. The rubber composition for a hose used in the hose of the present invention is not particularly limited as long as it is the rubber composition for a hose of the present invention.

[0041] One of the preferred embodiments of the hose of the present invention has an inner tube formed using the above-mentioned rubber composition for a hose. In one preferred embodiment, the hose of the present invention has the inner pipe, a reinforcing layer on the inner pipe, and an outer pipe on the reinforcing layer.

[0042] The hose of the present invention will be described below with reference to the accompanying drawings, but the hose of the present invention is not limited thereto. FIG. 1 is a perspective view showing cutaway layers (tubes) of a hose according to an embodiment of the present invention. In Fig. 1, a hose 1 has an inner tube 2, an upper layer of which is a reinforcing layer 3, and an upper layer of which is an outer tube 4. The inner tube 2 is preferably formed from the rubber composition of the present invention.

[0043] The inner pipe 2 preferably forms the innermost layer of the hose. The thickness of the inner pipe 2 may be arbitrarily designed according to need, but is preferably about 0.5 to 5.0 mm, and more preferably 0.8 to 3.0 mm, for example.

[0044] The hose of the present invention may also optionally have a reinforcing layer 3. It is preferable for the hose of the present invention to have a reinforcing layer, as this improves the tensile breaking strength, usable pressure range, and metal fitting attachability of the hose. Examples of reinforcing layers include braided, spiral, net, and film structures. Examples of materials for the reinforcing layer include organic threads (reinforcing threads) such as aramid fiber, nylon, rayon, vinylon, and polyester; and metal wires such as brass-plated or zinc-plated steel wire.

[0045] The outer pipe 4 is the outermost layer of the hose. Examples of materials that can be used to form the outer pipe 4 include rubber compositions containing butyl rubber, halogenated butyl rubber, ethylene propylene rubber, brominated isobutylene-p-methylstyrene copolymer rubber (BIMS), ethylene-acrylic ester copolymer rubber (AEM), etc. The thickness of the outer pipe is preferably 0.5 to 3 mm, and more preferably 0.8 to 2 mm.

[0046] The hose of the present invention can be produced, for example, by placing the unvulcanized rubber composition of the present invention in a cylindrical shape around a mandrel or the like, placing a reinforcing layer on the cylindrical shape, and then placing a rubber composition for an outer tube in a cylindrical shape around the reinforcing layer, and then heating the entire hose. The heating temperature is preferably 120°C or higher, more preferably 140 to 170°C. After sufficient cooling, the hose of the present invention can be obtained by removing it from the mandrel.

[0047] A preferred embodiment of the hose of the present invention is to use it as an automobile hose, for example.

[0048] The above-mentioned automobile hoses include, for example, piping for power steering systems of automobiles.

[0049] The fluid to be passed through the inside of the hose of the present invention is not particularly limited. Examples of the fluid include a fluid containing an oil having an aniline point of 90°C or higher, and in a preferred embodiment, a fluid containing an oil having an aniline point of 105°C or higher. [Example]

[0050] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0051] <Production of Rubber Composition> Each rubber composition was produced by mixing the components in the composition (parts by mass) shown in Table 1 below with a stirrer. In the crosslinking agent column of Table 1, the number in the upper row is the amount of product (PO 14-40) used as the crosslinking agent, and the number in the lower row is the amount of net peroxide in the product used as described above.

[0052] <Evaluation> The rubber compositions produced as described above were subjected to the following evaluations, and the results are shown in Table 1. <Low temperature> Sample preparation Each rubber composition obtained as described above was vulcanized for 60 minutes using a press molding machine at 148°C under a surface pressure of 3.0 MPa to prepare a vulcanized sheet having a thickness of 2 mm, and an I-shaped sample was cut out from the sheet.

[0053] Low temperature elastic recovery test Using each sample prepared as described above, a low-temperature elastic recovery test was carried out in accordance with ASTM D1329 to measure the temperature at which each sample recovered 10% of its elongation (TR-10).

[0054] Evaluation criteria When the result of the low-temperature elastic recovery test was −25° C. or lower, the low-temperature properties were evaluated as excellent. In the above case, the lower the result of the low-temperature elastic recovery test, the better the low-temperature properties. On the other hand, when the result of the low-temperature elastic recovery test exceeded -25°C, the low-temperature properties were evaluated as poor.

[0055] <Oil resistance> Preparation of test specimens Each rubber composition obtained as described above was vulcanized for 60 minutes using a press molding machine at 148°C under a surface pressure of 3.0 MPa to prepare a vulcanized sheet having a thickness of 2 mm. Test specimens were prepared from the vulcanized sheet in accordance with JIS K6258:2016.

[0056] Immersion test An immersion test was carried out in which each of the above test pieces was immersed in test oils 1 to 3 having respective aniline points at 135°C for 168 hours. The volume of the test piece was measured before and after immersion in each test oil, and the volume swelling ratio was calculated from the measured values ​​using the following formula. Volume swelling rate (%) = [(volume after immersion - volume before immersion) / (volume before immersion)] × 100

[0057] Evaluation criteria If the volume swelling rate for test oil 1 was 13% or less, the volume swelling rate for test oil 2 was 10% or less, and the volume swelling rate for test oil 3 was 3% or less, the oil resistance was evaluated as excellent. In the above case, the smaller any one of the volume swelling ratios for test oil 1, test oil 2, and test oil 3, the better the oil resistance. On the other hand, if the volume swelling rate for test oil 1 exceeded 13%, if the volume swelling rate for test oil 2 exceeded 10%, or if the volume swelling rate for test oil 3 exceeded 3%, the oil resistance was evaluated as poor.

[0058] [Table 1]

[0059] The details of each component shown in Table 1 are as follows: (HNBR) HNBR1: Hydrogenated acrylonitrile butadiene rubber. Product name: THERBANLT2007, manufactured by ARLANXEO. AN content: 21% by mass, hydrogenation rate: 99% HNBR2: Hydrogenated acrylonitrile butadiene rubber. Product name: THERBAN LT2057, manufactured by ARLANXEO. AN content: 21% by mass, hydrogenation rate: 95%

[0060] Comparative HNBR: Hydrogenated acrylonitrile butadiene rubber. Product name: ZETPOL2000L, manufactured by Zeon Corporation. AN content: 36% by mass, hydrogenation rate: 99%

[0061] (carbon black) Carbon Black 1 (FEF): FEF carbon black (manufactured by Nippon Steel Carbon Co., Ltd.), nitrogen adsorption specific surface area 41 m 2 / g, dibutyl phthalate oil absorption 121ml / 100g Carbon Black 2 (SRF): SRF carbon black (product name Niteron #S, manufactured by Shin-Nichika Carbon Co., Ltd.), nitrogen adsorption specific surface area 25 m 2 / g, dibutyl phthalate oil absorption 72ml / 100g

[0062] ·silica Adhesion promoter: MgO (magnesium oxide) Anti-aging agent: MBZ (2-mercaptobenzimidazole) manufactured by Ouchi Shinko Chemical Co., Ltd., Nocrac MBZ Crosslinking agent: ZnO (zinc oxide) manufactured by Seido Chemical Industry Co., Ltd., Zinc Oxide No. 3 Processing aid: stearic acid. Kao Corporation, Lunac YA

[0063] Co-crosslinking agent 1: TAIC (pure product). Triallyl isocyanurate. Manufactured by Nippon Kasei Co., Ltd., product name: TAIC Co-crosslinking agent 2: DAP (diallyl phthalate), manufactured by Daiso Co., Ltd.

[0064] (peroxide) Crosslinking agent: PO 14-40, manufactured by Kayaku Akzo Co., Ltd. It is a mixture of di-t-butylperoxydiisopropylbenzene and calcium carbonate, and the di-t-butylperoxydiisopropylbenzene content in the product is 40% by mass.

[0065] The results shown in Table 1 show that Comparative Example 1, which did not contain the specified HNBR but instead contained HNBR with an AN content exceeding 24% by mass, had poor low-temperature properties. Comparative Examples 2 and 3, in which the peroxide content was lower than the specified amount, had poor oil resistance. Comparative Example 4, in which the content of triallyl isocyanurate was lower than the predetermined value, had poor oil resistance.

[0066] In contrast, the rubber composition of the present invention is excellent in low temperature properties and oil resistance. [Explanation of symbols]

[0067] 1 hose 2 Inner tube 3 Reinforcement layer 4 Outer tube

Claims

1. The present invention comprises a hydrogenated acrylonitrile butadiene rubber having an acrylonitrile content of 18 to 24 mass%, carbon black, a peroxide, and triallyl isocyanurate, The content of the peroxide is 2.4 parts by mass or more and 6 parts by mass or less based on 100 parts by mass of the hydrogenated acrylonitrile butadiene rubber, The rubber composition for hoses has a content of the triallyl isocyanurate of 2.5 to 4.0 parts by mass based on 100 parts by mass of the hydrogenated acrylonitrile butadiene rubber.

2. The rubber composition for a hose according to claim 1, wherein the hydrogenation rate of the hydrogenated acrylonitrile butadiene rubber is 95 to 100%.

3. The rubber composition for a hose according to claim 1 or 2, wherein the content of the carbon black is 40 to 150 parts by mass based on 100 parts by mass of the hydrogenated acrylonitrile butadiene rubber.

4. The rubber composition for a hose according to any one of claims 1 to 3, wherein the amount of acrylonitrile in the hydrogenated acrylonitrile butadiene rubber is 18 to 22 mass%.

5. The rubber composition for a hose according to any one of claims 1 to 4, wherein a content of the peroxide is 2.8 to 6 parts by mass based on 100 parts by mass of the hydrogenated acrylonitrile butadiene rubber.

6. The rubber composition for a hose according to any one of claims 1 to 5, further comprising a diallyl compound.

7. A hose formed by using the rubber composition for a hose according to any one of claims 1 to 6.

8. The hose according to claim 7, which has an inner tube formed using the rubber composition for a hose.

9. 9. The hose according to claim 7 or 8, which allows a fluid having an aniline point of 105° C. or higher to flow therethrough.

10. The hose according to any one of claims 7 to 9, which is for use in automobiles.

11. The hose according to any one of claims 7 to 10, which is used for piping in a power steering system of an automobile.

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