JP2010077302A - Rubber composition for hose and hose - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber composition for a hose which exhibits a high modulus, good compression set and excellent durability of a caulking part between the hose and a clasp, and to provide a hose. <P>SOLUTION: The rubber composition for a hose contains chlorinated polyethylene whose calcium stearate content is lower than a normal content, preferably chlorinated polyethylene containing no calcium stearate, wherein calcium stearate is blended as an aggregation inhibitor in a process of producing chlorinated polyethylene. The hose is also provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rubber composition containing chlorinated polyethylene suitable for a material of a hose, particularly an oil resistant hose, and a hose composed of the composition, particularly an oil resistant hose comprising an inner tube and / or an outer tube.

  Conventionally, NBR, HNBR, chlorosulfonated polyethylene, chlorinated polyethylene, acrylic rubber, and the like have been used as rubber for oil-resistant hoses. Among them, chlorinated polyethylene is often used for automobile power steering hoses. However, commercially available chlorinated polyethylene usually contains a fatty acid metal salt in order to prevent aggregation of the chlorinated polyethylene by adding a fatty acid metal salt such as calcium stearate in the production process. is there. On the other hand, it is generally well known to add a fatty acid metal salt as an acid acceptor for halogen-containing polymers such as chlorinated polyethylene and vinyl chloride resin.

When a rubber composition for a hose is produced using a commercially available ordinary chlorinated polyethylene, the aforementioned fatty acid metal salt inhibits the crosslinking reaction, so that the modulus is low and the compression set resistance is poor, resulting in the hose. Since the durability of the caulking portion of the metal fitting is inferior, there is a problem that sufficient hose durability cannot be obtained. Conventionally, as a method for increasing the modulus, a method of blending a large amount of an organic peroxide as a crosslinking agent, a method of blending a co-crosslinking agent or a large amount, or a method of blending a large amount of carbon black has been adopted. ing.
However, when a large amount of an organic peroxide or a co-crosslinking agent is blended, the modulus is improved, but the strength such as tensile strength is lowered, and the workability is also deteriorated. In addition, when a large amount of carbon black is blended, the compression set resistance decreases. Thus, a chlorinated polyethylene hose rubber composition for hose having a high modulus, good compression set resistance, good workability, and good durability of the crimped portion of the hose and metal fitting is strongly desired.

  An object of the present invention is to provide a rubber composition for a hose having a high modulus, good compression set resistance, and excellent durability of a caulked portion of a hose and a metal fitting, and a hose using the same. It is.

  The present inventor has surprisingly found that a rubber composition using chlorinated polyethylene that does not contain calcium stearate or is contained in a small amount even if it is contained in a rubber production process is a normal amount of calcium stearate. As compared with a rubber composition using a chlorinated polyethylene containing bismuth, it has been found that the modulus is high, the compression set resistance is good, and the durability of the caulking portion is excellent, and the present invention has been completed. .

Accordingly, the present invention is a rubber composition for a hose containing the following chlorinated polyethylene, and a hose using the composition.
(1) A rubber composition for a hose excellent in modulus including chlorinated polyethylene substantially free from fatty acid metal salt and compression set resistance.
(2) The rubber composition for a hose according to the above (1), wherein the content of the fatty acid metal salt is 0.5 parts by mass or less with respect to 100 parts by mass of the chlorinated polyethylene.
(3) The rubber composition for a hose according to the above (1), comprising a chlorinated polyethylene not containing a fatty acid metal salt.
(4) The rubber composition for a hose according to any one of (1) to (3), wherein the fatty acid metal salt is calcium stearate.
(5) The rubber composition for a hose according to any one of (1) to (4), wherein the chlorine content of the chlorinated polyethylene is 20 to 50% by mass.

(6) The rubber composition for a hose according to any one of (1) to (5), wherein the reinforcing agent and / or the filler is contained in an amount of 30 to 120 parts by mass with respect to 100 parts by mass of the chlorinated polyethylene.
(7) The rubber composition for hoses according to any one of (1) to (6), wherein the organic peroxide is contained in an amount of 1 to 5 parts by mass with respect to 100 parts by mass of chlorinated polyethylene.
(8) The hose according to (7), wherein in the rubber composition for a hose containing an organic peroxide, triallyl isocyanurate (TAIC) is co-containing 1 to 15 parts by mass with respect to 100 parts by mass of chlorinated polyethylene. Rubber composition.
(9) The rubber composition for hoses containing an organic peroxide is selected from the group consisting of triallyl cyanurate, diallyl phthalate (DAP), 1,2-polybutadiene, and N, N′-m-phenylene dimaleimide. The rubber composition for a hose according to the above (7) or (8), which contains 1 to 15 parts by mass of at least one compound with respect to 100 parts by mass of chlorinated polyethylene.

(10) The rubber composition for a hose according to (6), wherein the reinforcing agent and / or filler is at least one compound selected from the group consisting of silica, talc and clay.
(11) The group further comprising tri-2-ethylhexyl trimellitate (C-8), isononyl trimellitate (C-9N), di-2-ethylhexyl phthalate, dioctyl adipate (DOA) and tricresyl phosphate The rubber composition for hoses according to any one of the above (1) to (10), wherein 2 to 50 parts by mass of at least one compound selected from 1 to 100 parts by mass of chlorinated polyethylene is contained.
(12) The above (1) to (3) further containing 3 to 20 parts by mass of at least one acid acceptor selected from the group consisting of magnesium oxide, calcium oxide, calcium hydroxide and epoxy resin with respect to 100 parts by mass of chlorinated polyethylene. The rubber composition for a hose according to any one of (11).
(13) A hose using the rubber composition according to any one of (1) to (12).
(14) An oil resistant hose using the rubber composition according to any one of (1) to (12) above.

  The rubber composition for hoses containing chlorinated polyethylene of the present invention has higher modulus and excellent compression set resistance than conventional rubber compositions for hoses containing chlorinated polyethylene. It is possible to provide an oil resistant hose excellent in durability of the caulking portion of the metal fitting. Further, since it is not necessary to add a large amount of a crosslinking agent or a reinforcing agent, the cost, the mixing processability of the rubber composition, and the extrusion processability are excellent.

  The chlorinated polyethylene used in the present invention has a chlorine content of 20 to 50% by mass, preferably 25 to 40% by mass, out of 100% by mass of chlorinated polyethylene. If the chlorine content is less than 20% by mass, the oil resistance is poor. Moreover, rubber elasticity will fall that it is more than 50 mass%. In particular, the low temperature characteristics deteriorate and rubber elasticity is lost at low temperatures.

  The chlorinated polyethylene used in the present invention contains substantially no fatty acid metal salt. Here, substantially not containing means that the content of the fatty acid metal salt is 0.5 parts by mass or less, preferably 0.4 parts by mass or less, more preferably 0 parts by mass, relative to 100 parts by mass of chlorinated polyethylene. That is, it is a case where no aliphatic metal salt is contained. When the content exceeds 0.5 parts by mass, the modulus decreases and the compression set resistance deteriorates.

  The fatty acid metal salt is a linear or branched fatty acid unit having 14 to 18 carbon atoms and a metal unit such as magnesium, calcium, barium, group 1 potassium, group 12 zinc, group 14 lead, etc. And a calcium salt, a magnesium salt, a barium salt, a potassium salt, or the like of a linear fatty acid such as stearic acid, palmitic acid, myristic acid, or a branched fatty acid such as neodecanoic acid.

  The rubber composition for hoses containing the chlorinated polyethylene of the present invention can contain other compounding agents in addition to the fatty acid metal salt. Examples of other compounding agents include a crosslinking agent, a co-crosslinking agent, an acid acceptor, a reinforcing agent, a filler, a plasticizer, and a softening agent. The specific example of a compounding agent and the compounding quantity with respect to 100 mass parts of chlorinated polyethylene of each compounding agent are shown below.

As the crosslinking agent, an organic peroxide is preferable. Organic peroxides include di-tert-butylhydroxyperoxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, 2,5-dimethyl-2,5-di (benzoyloxy) ) Hexane, benzoyl peroxide, 1,3-bis (tertiarybutylperoxyisopropyl) benzene, etc., with 1,3-bis (tertiarybutylperoxyisopropyl) benzene being preferred.
The compounding quantity of an organic peroxide is 1.0-5.0 mass parts as a net quantity of an organic peroxide, Preferably it is 1.5-3.0 mass parts.

  As the co-crosslinking agent, triallyl isocyanurate (TAIC), triallyl cyanurate, diallyl phthalate (DAP), 1,2-polybutadiene, N, N′-m-phenylene dimaleimide and the like are preferable, and TAIC is particularly preferable. The compounding quantity of a co-crosslinking agent is 1-15 mass parts, Preferably it is 3-10 mass parts.

  Non-fatty acid metal salts such as magnesium oxide, calcium oxide, and calcium hydroxide, and epoxy resins can be cited as acid acceptors that capture hydrochloric acid generated from chlorinated polyethylene. The compounding quantity of an acid acceptor is 3-20 mass parts, Preferably it is 5-10 mass parts.

Carbon black and silica are preferred as the reinforcing agent. Both can be used together. Also, other reinforcing agents can be blended.
If carbon black is furnace black, a grade will not be limited, However, Soft grade GPF, SRF, and FTF are especially preferable. The compounding quantity of carbon black is 30-120 mass parts, Preferably it is 50-90 mass parts.
Silica is preferably wet silica, and the amount of silica is 5 to 80 parts by mass, preferably 10 to 10 parts by mass.
40 parts by mass.

  Examples of the filler include inorganic compounds such as calcium carbonate, clay, talc, calcium silicate, titanium oxide, aluminum hydroxide, and zinc oxide. A filler may be used in combination. The filler may be used in combination with a reinforcing agent such as carbon black or silica. The blending amount of the filler is 5 to 150 parts by mass, preferably 20 to 100 parts by mass. Of course, the filler may act as a reinforcing agent.

  Examples of the plasticizer include trimellitic acid ester plasticizer, phthalic acid ester plasticizer, adipic acid ester plasticizer, and phosphoric acid ester plasticizer. Specifically, tri-2-ethylhexyl trimellitate ( C-8), isononyl trimellitate (C-9N), dioctyl phthalate (DOP), dibutyl phthalate (DBP), dioctyl adipate (DOA), tricresyl phosphate (TCP) and the like. The compounding quantity of a plasticizer is 2-50 mass parts, Preferably it is 5-30 mass parts.

  Aroma oils, naphthenic oils, paraffin oils, etc., called softeners (process oils) can also be blended. Moreover, liquid paraffin and chlorinated paraffin can also be mix | blended. The compounding quantity of a softening agent is 2-30 mass parts, Preferably it is 5-10 mass parts. The softener can be used in combination with a plasticizer.

  The rubber composition for hoses containing the chlorinated polyethylene of the present invention is produced by a usual kneading method of chlorinated polyethylene.

  A hose using the rubber composition for a hose of the present invention includes at least an inner tube, a reinforcing layer including a reinforcing fiber disposed adjacent to the outer peripheral side of the inner tube, and an outer peripheral side of the reinforcing layer. And a hose having an outer pipe arranged. At least one of the inner tube and the outer tube, preferably both, of the hose is a hose composed of the rubber composition for a hose of the present invention.

An example of a preferred embodiment of the hose of the present invention will be described with reference to FIG. FIG. 1 is a perspective view of each hose layer cut away.
As shown in FIG. 1, the hose 1 includes an inner tube 2, a reinforcing layer 3 disposed adjacent to the outer peripheral side of the inner tube 2, and an outer tube 4 disposed adjacent to the outer peripheral side of the reinforcing layer 3. And have.

The inner tube 2 and the outer tube 4 are provided adjacent to the reinforcing layer 3. In the present invention, the rubber composition for a hose of the present invention is formed on either the inner tube 2 or the outer tube 4, preferably both. Moreover, when the rubber composition for hoses of this invention is used, since the deterioration of the fiber of the reinforcement layer 3 is little and adhesion | attachment is also favorable, durability of a hose improves.
In addition to the three-layer structure, the hose of the present invention may have, for example, a five-layer structure in which two reinforcing layers are provided and an interlayer rubber layer is provided between these reinforcing layers.

  The hose is not used as a single unit, but is always used with metal fittings attached at both ends. The durability of the mounting (caulking) portion is a very important characteristic because it determines the life of the hose. In order to improve the durability of the caulking portion, it is effective to make the modulus of the rubber composition generally used for the inner tube 2 and the outer tube 4 close to the modulus of the metal fitting. Therefore, it is necessary to increase the modulus of the rubber composition used for the inner tube 2. In addition, it is necessary to reduce the compression set of the rubber composition, which is an index of hose sagability. The rubber composition for a hose of the present invention has a high modulus and a low compression set resistance. Therefore, when used as a material for the inner tube 2 and the outer tube 4 of the hose, the durability of the caulking portion is improved, and the hose The durability can be further improved.

The thickness of the inner tube 2 is preferably 0.2 to 4.0 mm, and more preferably 0.5 to 2.0 mm.
The thickness of the outer tube 4 is preferably 0.2 to 4.0 mm, and more preferably 0.5 to 2.0 mm.

  The reinforcing layer 3 may be formed in a blade shape or a spiral shape. As the fiber constituting the reinforcing layer 3, polyamide fiber, particularly 66-nylon, is suitable.

The manufacturing method of the hose of this invention is not specifically limited, A conventionally well-known method can be used.
Specifically, after laminating an inner tube, a reinforcing layer, and an outer tube in this order on a mandrel, these layers are subjected to press vulcanization, steam vulcanization under conditions of 140 to 190 ° C. and 30 to 180 minutes, Preferred examples include a method of vulcanizing and bonding by oven vulcanization (hot air vulcanization) or hot water vulcanization.

  Since the hose of the present invention uses the rubber composition for a hose of the present invention, the hose is excellent in heat resistance, excellent in modulus and compression set, and more excellent in the durability of the caulked portion.

Next, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these.
(Examples 1-4, Comparative Examples 1-7)
A rubber composition was manufactured by mixing 100 parts by mass of the chlorinated polyethylene shown in Table 1 with the compounding agent shown in Table 1 at a ratio (parts by mass) shown in Table 1 using a B-type Banbury mixer. For each rubber composition obtained, the following methods were used to determine the Mooney viscosity, minimum torque (ML), maximum torque (MH) of the rubber composition before vulcanization, and the breaking strength of the rubber composition after vulcanization ( Tb), elongation at break (Eb), 50% modulus (M50), 100% modulus (M100), hardness (HS) and compression set (PS) were measured. Further, generally, the durability of the caulking portion is preferably higher in rubber hardness and smaller in PS, so that the smaller the numerical value represented by (PS / HS) × 100, the better. Specifically, the chlorine content of chlorinated polyethylene is preferably 39% or less when the chlorine content is less than 33% by mass, and 47% or less when the chlorine content of chlorinated polyethylene is 33% by mass or more. The measurement results and calculation results are shown in Table 1.
The details of the chlorinated polyethylene and the compounding agent in Table 1 are as follows.

(Chlorinated polyethylene)
“Tyrin CM730”: Mooney viscosity (ML _{1 + 4} , 121 ° C.) 65, manufactured by Dow Chemical Co. Ltd.
Chlorine content 30% by mass, calcium stearate content 0% by mass
“Tyrin CM0136”: Mooney viscosity (ML _{1 + 4} , 121 ° C.) 88 manufactured by Dow Chemical Co. Ltd.
Chlorine content 36% by mass, calcium stearate content 0% by mass
"Eraslen 301": Mooney viscosity (ML _{1 + 4} , 121 ° C) 85, manufactured by Showa Denko KK
Chlorine content 32% by mass, calcium stearate content 0.6% by mass
"Daisolac C-123": Mooney viscosity (MS _{1 + 4} , 100 ° C) 41 manufactured by Daiso Corporation
Chlorine content 30% by mass, calcium stearate content 0.9% by mass
-“Daisolac H-135”: Mooney viscosity (MS _{1 + 4} , 100 ° C.) 45.5, manufactured by Daiso Corporation
Chlorine content 35% by mass, calcium stearate content 2.7% by mass

(Combination agent)
・ 1,3-bis (tert-butylperoxyisopropyl) benzene manufactured by Kayaku Akzo Co., Ltd .: “Perkadox 14/40” (net amount of peroxide 40% by mass)
・ Triallyl isocyanate (TAIC): “PARKA LINK 301-70DPD” manufactured by Akzo Chemicals Co., Ltd.
・ Epoxy resin: Sumitomo Chemical Co., Ltd. “Sumiepoxy ELA-115”
-SRF carbon black: Asahi 50 manufactured by Asahi Carbon Co., Ltd.
-Tri-2-ethylhexyl trimellitate (C-8): "Monocizer W-700" manufactured by Dainippon Ink & Chemicals, Inc.
・ Calcium stearate: Made by Shodo Chemical Co., Ltd., reagent grade 1

(Mooney viscosity)
In accordance with JIS K6300-1, for chlorinated polyethylene, an L-shaped rotor or an S-shaped rotor is used, the temperature is measured at 121 ° C. for an L-shaped (large type) rotor, and 100 for an S-shaped (small type) rotor. Measured at ° C. Here, ML _{1 + 4} means measurement with an L-shaped rotor, and MS _{1 + 4} means measurement with an S-shaped rotor.

(ML, MH)
In accordance with JIS K6300-2, the unvulcanized rubber composition was vulcanized with a vulcanization tester, and the minimum torque (ML) and the maximum torque (MH) were detected from the rheometer curve.

(Breaking strength, breaking elongation, 50% modulus, 100% modulus)
In accordance with JIS K6251, vulcanized rubber obtained by vulcanizing each composition at 153 ° C. for 60 minutes was cut into a dumbbell shape (No. 3 type) having a thickness of 2 mm, and used as a test piece. Under the condition of min, the breaking strength, breaking elongation, 50% modulus (M50) and 100% modulus (M100) were measured. The breaking strength is preferably 18 MPa or more, and the breaking elongation depends on the balance with the modulus, but is preferably 150% or more. Further, M50 is preferably 4.0 MPa or more when the chlorine content of chlorinated polyethylene is less than 33% by mass, and 3.6 MPa or more when the chlorine content of chlorinated polyethylene is 33% by mass or more. When the chlorine content of the chlorinated polyethylene is less than 33% by mass, it is preferably 11.0 MPa or more, and when the chlorine content of the chlorinated polyethylene is 33% by mass or more, it is preferably 10.0 MPa or more.

(Hardness HS)
In accordance with JIS K6253, each composition was vulcanized at 153 ° C. for 60 minutes to prepare a test piece having a thickness of 6 mm and measured using a durometer (type A). HS is preferably 75 or more.

(Compression set PS)
In accordance with JIS K6262, each composition was vulcanized at 153 ° C. for 60 minutes to produce a test piece having a diameter of 13.0 mm and a thickness of 6.3 mm. Next, the obtained test piece was compressed with a compression strain of 25% at 150 ° C. for 72 hours. PS was calculated by measuring the thickness of the test piece after compression was stopped and allowed to stand for 30 minutes. PS is preferably 30% or less when the chlorine content of chlorinated polyethylene is less than 33% by mass, and 35% or less when the chlorine content of chlorinated polyethylene is 33% by mass or more. For Example 6 and Comparative Example 9, each test piece was compressed at 120 ° C. for 72 hours with a compression strain of 25%.

  From the comparison between Example 1 and Comparative Example 4, chlorinated polyethylene having a calcium stearate content of 0% by mass (chlorine content of 30% by mass) and chlorinated polyethylene having a calcium stearate content of 0.9% by mass are shown. There are 4.4 to 2.9 differences for M50, 12.1 to 9.9 differences for M100, and 79 to 72 differences for HS. Furthermore, when (PS / HS) × 100 is compared, there is a difference of 35.6 vs. 40.0. That is, it is clear that a slight difference in the content of calcium stearate causes an unexpected difference in the durability of the modulus, HS and caulking portion.

  Further, from comparison between Example 3 and Comparative Example 7, chlorinated polyethylene having a calcium stearate content of 0 mass% (chlorine content of 36 mass%) and chlorine having a calcium stearate content of 2.7 mass% Difference between the chlorinated polyethylene (chlorine content 35% by mass) for M50: 3.7 vs. 2.9, for M100: 10.5: 9.2, for HS: 75:72 , There is a difference of 34.0 vs. 35.7 for PS. Furthermore, when (PS / HS) × 100 is compared, there is a difference of 45.3 vs. 49.6. That is, it is clear that a slight difference in the content of calcium stearate leads to an unexpected difference in hardness, modulus, PS and durability of the caulking portion.

(Examples 5-6, Comparative Examples 8-9)
A rubber composition was produced by mixing 100 parts by mass of the chlorinated polyethylene shown in Table 2 with the compounding agent shown in Table 2 at a ratio (parts by mass) shown in Table 2 using a B-type Banbury mixer. About each obtained rubber composition, ML and MH of the rubber composition before vulcanization, and HS and PS of the rubber composition after vulcanization were measured by the same method as Example 1. The measurement results are shown in Table 2.
Details of the compounding agents in Table 2 are as follows. Details of the chlorinated polyethylene and other compounding agents are as described in Example 1.

(Combination agent)
Magnesium oxide: “Kyowa Mag 150” manufactured by Kyowa Chemical Co., Ltd.
・ Isononyl trimellitate (C-9N): “ADEKA SIZER C-9N” manufactured by ADEKA Corporation

  From a comparison between Example 6 and Comparative Example 9, Example 6 in which calcium stearate was not added after blending into chlorinated polyethylene having a calcium stearate content of 0% by mass (chlorine content 36% by mass) and the content of calcium stearate Compared to Comparative Example 9 in which calcium stearate was blended after 2% by mass with 0% by mass of chlorinated polyethylene (chlorine content: 36% by mass), the difference in ML was 25.7 vs. 15.8, MH There is a difference of 146.5 vs. 111.8 for PS, and a difference of 8.2 vs. 11.1 for PS. That is, it is clear that a large amount of calcium stearate after blending causes an unexpected difference in PS.

(Example 7, Comparative Example 10)
Using the rubber composition of Example 1 for the inner tube and the rubber composition of Example 3 for the outer tube, the hose of Example 7 was produced by the following method.
The rubber composition of Example 1 was extruded onto a mandrel previously coated with a release agent to form an inner tube having a thickness of 2 mm. On this inner tube, a 66-polyamide fiber [manufactured by Asahi Kasei Co., Ltd., “Leona 66”] was braided to form a reinforcing layer. Further, the rubber composition of Example 3 was extruded outside the reinforcing layer to form an outer tube having a thickness of 1.5 mm. Next, after vulcanizing by heating at 154 ° C. for 90 minutes, the mandrel was pulled out to produce a power steering hose. A predetermined metal fitting was attached to the hose, and the following test was performed.
Similarly, the hose of Comparative Example 10 was produced in the same manner using the rubber composition of Comparative Example 4 for the inner tube and the rubber composition of Comparative Example 5 for the outer tube, and the following tests were performed.

(Oil leakage test from the caulked part after heat aging)
The oil [Idemitsu Kosan Co., Ltd., “Toughney Hydro Super”] was sealed in the obtained power steering hose and allowed to stand in an oven at 150 ° C. for 240 hours, cooled to room temperature, and 3 MPa at room temperature. The oil leakage from the caulked portion when pressure was applied was visually observed. The hose of Example 7 had no oil leakage and no abnormal appearance. The hose of Comparative Example 10 had some oil bleeding and the caulked portion expanded. In short, the power steering hose using the rubber composition using the chlorinated polyethylene not containing calcium stearate of the present invention for the outer tube material and the inner tube material showed excellent durability of the caulked portion.

The perspective view which notched each layer of an example of the hose of this invention.

Explanation of symbols

1 Hose 2 Inner pipe 3 Reinforcement layer 4 Outer pipe

Claims (9)

  A rubber composition for a hose which is excellent in modulus and compression set resistance, including chlorinated polyethylene substantially free of fatty acid metal salt.   The rubber composition for a hose according to claim 1, wherein the content of the fatty acid metal salt is 0.5 parts by mass or less with respect to 100 parts by mass of the chlorinated polyethylene.   The rubber composition for hoses according to claim 1, comprising chlorinated polyethylene that does not contain a fatty acid metal salt.   The rubber composition for hoses according to any one of claims 1 to 3, wherein the fatty acid metal salt is calcium stearate.   The rubber composition for hoses according to any one of claims 1 to 4, wherein the chlorinated polyethylene has a chlorine content of 20 to 50% by mass.   The rubber composition for a hose according to any one of claims 1 to 5, comprising a reinforcing agent and / or a filler in an amount of 30 to 120 parts by mass with respect to 100 parts by mass of chlorinated polyethylene.   The rubber composition for hoses according to any one of claims 1 to 6, comprising 1 to 5 parts by mass of an organic peroxide with respect to 100 parts by mass of chlorinated polyethylene.   The rubber composition for hoses according to claim 7, wherein the rubber composition for hoses containing an organic peroxide contains 1 to 15 parts by mass of triallyl isocyanurate per 100 parts by mass of chlorinated polyethylene.   The oil-resistant hose using the rubber composition in any one of Claims 1-8.

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