JP2012072291A - Rubber composition for water hose, and water hose obtained by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber composition for a water hose for obtaining an inexpensive, thin and light-weight hose causing no uneven thickness (formation of wrinkles or bumps) by reducing a coating weight of a material derived from fossil fuels per unit weight.SOLUTION: The rubber composition for the water hose includes a components (A), (B) and (C). In the component (B), a melt flow rate (MFR) at 190°C under a load of 2.16 kg is 1.0 g/10 min, and a density is 0.870-0.908 g/cm. In the component (C), a pH is 5.5 or higher and an average particle diameter is 3.5 μm or more. The component (A) is an ethylene-propylene rubber. The component (B) is an ethylene-octene resin. The component (C) is clay.

Description

  The present invention relates to a rubber composition for an aqueous hose used for an aqueous hose such as a radiator hose used for connecting an engine and a radiator in a vehicle such as an automobile, and an aqueous hose obtained using the rubber composition.

  Conventionally, water-based hoses for vehicles used to connect engines to radiators and heater cores are mainly composed of synthetic rubber such as ethylene-propylene-diene terpolymer rubber (EPDM), and carbon black. A rubber composition containing oil or oil is used (see Patent Document 1).

  Synthetic rubber such as EPDM, carbon black, oil and other materials are derived from fossil fuels, and therefore it is necessary to save resources from the viewpoint of fossil fuel depletion.

  Therefore, in order to reduce the basis weight of the material derived from fossil fuel per unit volume, the combined use of natural minerals has been studied. In addition, in order to reduce the amount of material used for the hose, a method of reducing the thickness of the hose, for example, reducing the thickness of the hose from the conventional 5 mm to 3.5 mm has been studied.

Japanese Patent Laid-Open No. 11-293053

  However, if natural minerals are used instead of fossil fuel-derived materials such as carbon black in order to reduce the basis weight of fossil fuel-derived materials per unit weight, the processability (formability) when unvulcanized Deterioration and problems of insufficient hose strength occur.

  In addition, when trying to make a conventional thick-walled (about 5 mm thick) hose thin (about 3.5 mm thick), as shown in FIG. 1, the inside of the bent portion 1a of the hose 1 is easily compressed. In the bent part 1a of the hose 1, there also arises a problem that uneven thickness (wrinkles) 2 occurs.

  The present invention has been made in view of such circumstances, and enables a reduction in the thickness of the hose constituent material while reducing the basis weight of the material derived from fossil fuel per unit volume and reducing the basis weight of the material constituting the hose. An object of the present invention is to provide a rubber composition for an aqueous hose and an aqueous hose capable of obtaining an aqueous hose free from occurrence of meat (wrinkles).

In order to achieve the above object, the present invention contains (B) and (C) components together with the following component (A), and the melt flow rate of component (B) at a temperature of 190 ° C. and a load of 2.16 kg. (MFR) is 1.0 g / 10 min, the density is 0.870 to 0.908 g / cm ³ , the pH of the component (C) is 5.5 or more, and the average particle size is 3.5 μm or more. The rubber composition for water-based hoses which is the first gist.
(A) Ethylene-propylene rubber.
(B) Ethylene-octene resin.
(C) Clay.

  The present invention also relates to an aqueous hose having a bent shape obtained by vulcanizing an unvulcanized hose inserted in a bent tube-shaped mandle, wherein the aqueous hose is the rubber composition for an aqueous hose. A water-based hose formed by using is used as a second gist.

That is, the present inventors have repeated experiments by paying particular attention to clay among natural minerals in order to reduce the basis weight of the material derived from fossil fuel per unit capacity. The present inventors have found that the hose strength is maintained when a clay having a pH of 5.5 or more and an average particle diameter of 3.5 μm or more is used. In addition, the present inventors also examined the use of an ethylene-olefin resin, which is an organic filler, for the purpose of thinning the wall, but can sufficiently suppress the occurrence of uneven thickness (wrinkles) due to the hose thinning. There wasn't. Therefore, when the cause of uneven thickness (wrinkles) was repeatedly studied, the strength of the unvulcanized hose was insufficient, and it was found that uneven thickness (wrinkles) was likely to occur when the mandle was inserted. Therefore, in order to solve this problem, the ethylene-olefin resin used as the organic filler is particularly focused on the ethylene-octene resin, and research has been repeated focusing on the melt flow rate (MFR) and density. The higher the melt flow rate (MFR) that is an index of molecular weight, the higher the molecular weight, the higher the unvulcanized rubber strength, and the higher the density that is an index of molecular chain branching, the less the molecular chain branching. Therefore, the knowledge that the mixing property with ethylene-propylene rubber was improved was obtained. Therefore, as a result of repeated experiments on the optimum melt flow rate (MFR) and density of ethylene-octene resin, the melt flow rate (MFR) at a temperature of 190 ° C. and a load of 2.16 kg was 1.0 g / 10 min. The inventors have found that the intended purpose can be achieved by using an ethylene-octene resin having a density of 0.870 to 0.908 g / cm ³ , and the present invention has been achieved. The reason for this is not clear, but if an ethylene-octene resin with a melt flow rate (MFR) and density set in a specific range is used, the side chain of the ethylene-octene resin tends to be entangled with the ethylene-propylene rubber. As a result, it is surmised that the unvulcanized strength is improved and the occurrence of uneven thickness (wrinkles) at the time of inserting the mandle can be suppressed.

  As described above, the rubber composition for water hoses of the present invention is an ethylene-octene resin (B component) having a predetermined melt flow rate (MFR) and density among ethylene-olefin resins used as organic fillers. ), It is possible to obtain a water-based hose such as a radiator hose that is thin and lightweight without causing uneven thickness (wrinkles). Moreover, since the clay having a pH of 5.5 or more and an average particle diameter of 3.5 μm or more is used, the hose strength is not lowered. In this way, the use of specific clay can reduce the amount of a fossil fuel-derived material (carbon black or the like) used, so that the resource amount per product unit can be saved.

  Further, when the clay (component C) is a surface-treated clay surface-treated with a polyhydric alcohol such as diethylene glycol (DEG), a vulcanized material (such as a vulcanizing agent or a vulcanization accelerator) is added to the surface of the clay. It is possible to prevent the loss of the vulcanized material due to the adsorption, and the sealing performance and breaking strength are further improved.

  And the content of the clay (C component) is 30 to 150 parts by weight relative to 100 parts by weight of the ethylene-propylene rubber (A component), the hose strength can be kept within an allowable range. In addition, high-filling clay (C component) with high insulating properties increases the volume resistivity and improves the electrochemical stability, so that it is possible to take measures against pipe contact.

  Further, when the content of the ethylene-octene resin (component B) is 5 to 30 parts by weight with respect to 100 parts by weight of the ethylene-propylene rubber (component A), the ethylene-propylene rubber (component A) The unvulcanized strength due to the entanglement with the rubber is further improved, and the mixing property with the ethylene-propylene rubber (component A) is further improved.

  Since the water-based hose of the present invention is formed using the above-mentioned special water-based hose rubber composition, the strength of the unvulcanized hose is improved, and the bent portion of the hose has no uneven thickness (wrinkles), thickness 3 A lightweight hose with a uniform thickness of 5 mm or less can be obtained.

It is a schematic diagram explaining the generation | occurrence | production state of the uneven thickness (wrinkle) in a thin hose.

  Next, embodiments of the present invention will be described in detail. However, the present invention is not limited to this embodiment.

The rubber composition for water hoses of the present invention (hereinafter sometimes referred to simply as “rubber composition”) includes an ethylene-propylene rubber (component A), an ethylene-octene resin (component B), clay (C Component).
In the present invention, the ethylene-octene resin (component B) has a melt flow rate (MFR) of 1.0 g / 10 min at a temperature of 190 ° C. and a load of 2.16 kg, and a density of 0.870 to 0.00. was 908 g / cm ^3, pH of the clay (C component) 5.5 or more, an average particle size of 3.5μm or more. In the present invention, these are the greatest features.

  Next, these components will be described.

<< Ethylene-propylene rubber (component A) >>
Examples of the ethylene-propylene rubber (component A) include ethylene-propylene-diene terpolymer rubber (EPDM), ethylene-propylene copolymer rubber (EPM), and the like, alone or in combination of two or more. Used.

  The ethylene-propylene rubber (component A) is preferably one having an iodine value in the range of 6 to 30 and an ethylene ratio in the range of 48 to 70% by weight from the viewpoint of excellent stability at high temperature and pressure. Preferably, the iodine value is in the range of 10 to 24, and the ethylene ratio is in the range of 50 to 60% by weight.

  The diene monomer (third component) contained in the EPDM is preferably a diene monomer having 5 to 20 carbon atoms, specifically 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene. 2,5-dimethyl-1,5-hexadiene, 1,4-octadiene, 1,4-cyclohexadiene, cyclooctadiene, dicyclopentadiene (DCP), 5-ethylidene-2-norbornene (ENB), 5- Butylidene-2-norbornene, 2-methallyl-5-norbornene, 2-isopropenyl-5-norbornene and the like. Among these diene monomers (third component), dicyclopentadiene (DCP) and 5-ethylidene-2-norbornene (ENB) are preferable.

<< Ethylene-octene resin (component B) >>
Examples of the ethylene-octene resin (component B) include those obtained by copolymerizing ethylene and octene-1.

  The ethylene-octene resin (component B) has a melt flow rate (MFR) (190 ° C., 2.16 kg load) in the range of 1.0 g / 10 min. That is, if the MFR of the B component is too small, the molecular weight is too small and the unvulcanized strength is inferior, resulting in uneven thickness (wrinkles) when inserting the mandle, and conversely if the MFR of the B component is too large. This is because the molecular weight is too large and the unvulcanized strength is too high, so that the mandle insertion property is deteriorated.

  In the present specification, “melt flow rate (MFR)” means a melt flow rate (MFR) at a temperature of 190 ° C. and a load of 2.16 kg unless otherwise specified. Melt flow rate (MFR) is synonymous with melt index.

The ethylene-octene resin (component B) has a density in the range of 0.870 to 0.908 g / cm ³ . That is, if the density of the B component is too small, there are many molecular chain branches, so the compatibility with the ethylene-propylene rubber (A component) deteriorates. Conversely, if the density of the B component is too high, molecular chain branching occurs. This is because the amount of entanglement with the ethylene-propylene rubber (component A) is small, the unvulcanized strength is insufficient, and uneven thickness (wrinkles) occurs when the mandle is inserted.

  The content of the ethylene-octene resin (component B) is preferably in the range of 5 to 30 parts by weight, particularly preferably in the range of 10 to 20 parts by weight with respect to 100 parts by weight of the ethylene-propylene rubber (component A). It is. That is, if the B component is too small, the effect of improving the unvulcanized strength due to the entanglement with the ethylene-propylene rubber (A component) is poor. Conversely, if the B component is too large, the processability tends to deteriorate. Because it is.

《Clay (C component)》
The clay (component C) has a pH of 5.5 or higher, preferably a pH of 5.8 or higher, and particularly preferably a pH of 5.8 to 8.2. That is, if the pH of the clay (component C) is less than 5.5, the compression set and the breaking strength are inferior. The clay (component C) has an average particle size of 3.5 μm or more, preferably 3.8 μm or more, and particularly preferably 3.8 to 8.7 μm. That is, if the average particle size of the clay (C component) is too small, the compression set and the breaking strength are inferior.

  The pH of the clay (component C) is, for example, by putting 2.5 g of clay in a glass conical Erlenmeyer flask, adding water (50 ml), heating, and immediately boiling to cool to room temperature. It can be obtained by measuring with.

  Moreover, the average particle diameter of the clay (component C) can be calculated by, for example, particle size distribution measurement. In the present invention, the average particle size of the clay (component C) (hereinafter sometimes simply referred to as “particle size”) means the primary particle size.

  As the clay (component C) in the present invention, a surface-treated clay whose surface is treated with a polyhydric alcohol such as diethylene glycol (DEG) may be used. In the present invention, a clay that has not been surface-treated and a surface-treated clay can be used in combination.

  The surface-treated clay can be produced by kneading a polyhydric alcohol such as diethylene glycol (DEG) and clay with a Banbury mixer or kneader at the time of kneading A.

  The content of the clay (component C) is preferably in the range of 30 to 150 parts by weight, particularly preferably in the range of 40 to 100 parts by weight with respect to 100 parts by weight of the ethylene-propylene rubber (component A). That is, if the C component is too small, it will be difficult to reduce the cost by reducing the basis weight of the material derived from fossil fuel per unit weight. Conversely, if the C component is too large, the processability during unvulcanization will be reduced. This is because (formability) deteriorates and the hose strength tends to decrease.

  In addition to the ethylene-propylene rubber (component A), ethylene-octene resin (component B) and clay (component C), the rubber composition of the present invention includes carbon black, a vulcanizing agent, a vulcanization accelerator, Vulcanizing aids, process oils, co-crosslinking agents, anti-aging agents, thickeners, white fillers such as calcium carbonate, talc, etc. may be appropriately blended as necessary. These may be used alone or in combination of two or more.

"Carbon black"
As the carbon black, those excellent in extrudability and reinforcing properties are preferable. For example, those of SAF class, ISAF class, HAF class, MAF class, FEF class, GPF class, SRF class, FT class, MT class, etc. Is given. These may be used alone or in combination of two or more.

  The content of the carbon black is preferably in the range of 20 to 150 parts by weight, particularly preferably in the range of 60 to 120 parts by weight with respect to 100 parts by weight of the ethylene-propylene rubber (component A). That is, if the carbon black content is too low, the effect of reinforcing properties is poor, and it is difficult to increase the hardness. Conversely, if the carbon black content is too high, the volume resistivity decreases and the electrical insulation property This is because there is a tendency to become worse.

《Vulcanizing agent》
As the vulcanizing agent, for example, sulfur, peroxide vulcanizing agent (peroxide vulcanizing agent) or the like is used alone or in combination. Among these, sulfur is preferable in terms of storage stability and cost.

  Examples of the peroxide vulcanizing agent include 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) -3,3. , 5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) cyclododecane, 1,1-bis (t-butylperoxy) cyclohexane, , 2-bis (t-butylperoxy) octane, n-butyl-4,4-bis (t-butylperoxy) butane, n-butyl-4,4-bis (t-butylperoxy) valerate, etc. Peroxyketals, di-t-butyl peroxide, dicumyl peroxide, t-butylcumyl peroxide, α, α'-bis (t-butylperoxy-m-iso Propyl) benzene, α, α′-bis (t-butylperoxy) diisopropylbenzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-bis Dialkyl peroxides such as (t-butylperoxy) hexyne-3, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl Diacyl peroxides such as peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, m-trioyl peroxide, t-butyl peroxyacetate, t-butyl peroxyisobutyrate, t-butyl peroxide Oxy-2-ethylhexanoate , T-butyl peroxylaurate, t-butyl peroxybenzoate, di-t-butyl peroxyisophthalate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butyl peroxymalein Peroxyesters such as acid, t-butylperoxyisopropyl carbonate, cumylperoxyoctate, t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2, And hydroperoxides such as 5-dihydroperoxide and 1,1,3,3, -tetramethylbutyl peroxide. These may be used alone or in combination of two or more.

  The content of the vulcanizing agent is preferably in the range of 0.5 to 15.0 parts by weight, particularly preferably 1.0 to 10.0 with respect to 100 parts by weight of the ethylene-propylene rubber (component A). The range is parts by weight.

《Vulcanization accelerator》
Examples of the vulcanization accelerator include vulcanization accelerators such as thiazole, sulfenamide, thiuram, aldehyde ammonia, aldehyde amine, guanidine, and thiourea. These may be used alone or in combination of two or more. Of these, sulfenamide-based vulcanization accelerators are preferred because they are excellent in vulcanization reactivity.

  The content of the vulcanization accelerator is preferably in the range of 0.1 to 10.0 parts by weight, particularly preferably 0.5 to 5.0 parts per 100 parts by weight of ethylene-propylene rubber (component A). The range is parts by weight.

  Examples of the thiazole vulcanization accelerator include dibenzothiazyl disulfide (DM), 2-mercaptobenzothiazole (M), 2-mercaptobenzothiazole sodium salt (NaMBT), and 2-mercaptobenzothiazole zinc salt (ZnMBT). Etc. These may be used alone or in combination of two or more. Among these, dibenzothiazyl disulfide (DM) and 2-mercaptobenzothiazole (M) are preferable in terms of excellent vulcanization reactivity.

  Examples of the sulfenamide-based vulcanization accelerator include N-oxydiethylene-2-benzothiazolylsulfenamide (NOBS), N-cyclohexyl-2-benzothiazolylsulfenamide (CM), and Nt. -Butyl-2-benzothiazoylsulfenamide (BBS), N, N'-dicyclohexyl-2-benzothiazoylsulfenamide and the like. These may be used alone or in combination of two or more.

  Examples of the thiuram vulcanization accelerator include tetramethylthiuram disulfide (TT), tetraethylthiuram disulfide (TET), tetrabutylthiuram disulfide (TBTD), tetrakis (2-ethylhexyl) thiuram disulfide (TOT), and tetrabenzylthiuram. And disulfide (TBZTD). These may be used alone or in combination of two or more.

《Vulcanization aid》
Examples of the vulcanization aid include zinc white (ZnO), stearic acid, magnesium oxide and the like. These may be used alone or in combination of two or more.

  The content of the vulcanization aid is preferably in the range of 1 to 25 parts by weight, particularly preferably in the range of 3 to 10 parts by weight, with respect to 100 parts by weight of the ethylene-propylene rubber (component A).

<Process oil>
Examples of the process oil include naphthenic oil, paraffinic oil, and aroma oil. These may be used alone or in combination of two or more.

  The content of the process oil is preferably in the range of 5 to 100 parts by weight, particularly preferably in the range of 20 to 80 parts by weight with respect to 100 parts by weight of the ethylene-propylene rubber (component A).

《Co-crosslinking agent》
As the co-crosslinking agent, for example, divinylbenzene, triallyl isocyanurate (TAIC) is preferably used, and together with these, triallyl cyanurate, diacetone diacrylamide, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, trimethylol. Propane trimethacrylate, trimethylolpropane triacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, diisopropenylbenzene, p-quinonedioxime, p, p-dibenzoylquinonedioxime, phenylmaleimide, allyl Methacrylate, N, Nm-phenylene bismaleimide, diallyl phthalate, tetraallyloxyethane, 1,2 Polybutadiene and the like. These may be used alone or in combination of two or more.

  The content of the co-crosslinking agent is preferably in the range of 0.1 to 10.0 parts by weight, particularly preferably 0.5 to 5.0 parts by weight with respect to 100 parts by weight of the ethylene-propylene rubber (component A). Part range.

《Anti-aging agent》
Examples of the anti-aging agent include carbamate-based, phenylenediamine-based, phenol-based, diphenylamine-based, quinoline-based anti-aging agents, waxes, and the like. These may be used alone or in combination of two or more.

  The content of the antioxidant is preferably in the range of 0.1 to 10.0 parts by weight, particularly preferably 0.5 to 5.0 parts by weight with respect to 100 parts by weight of the ethylene-propylene rubber (component A). Part range.

  The rubber composition for water-based hoses of the present invention, for example, blends ethylene-propylene rubber (component A) with ethylene-octene resin (component B) and clay (component C) as an organic filler, as necessary. Carbon black, a vulcanizing agent, a process oil, a vulcanization accelerator, and the like can be blended and kneaded using a kneader such as a kneader, a Banbury mixer, or a roll.

  The aqueous hose of the present invention can be produced, for example, as follows using the rubber composition prepared as described above. That is, the rubber hose composition prepared as described above is extruded to produce an unvulcanized hose. It is also possible to produce an unvulcanized hose by extruding a rubber composition on a straight mandle. Next, a predetermined bent pipe-shaped mandrel is prepared, and the unvulcanized hose is inserted on the mandrel with an insertion machine or an operator's finger, and the predetermined condition (140 to 160 ° C. × 30 to 60 minutes). ) And then pulling out the mandle, a radiator hose having a desired bent shape can be produced. The water-based hose of the present invention thus obtained has an inner diameter of usually 5 to 50 mm, a thickness of 3.5 mm or less, and no bending (wrinkle) in the bent portion of the hose. It is a feature.

  The water-based hose of the present invention is characterized in that it is thinner than a conventional thick (about 5 mm thick) hose, and the thickness is preferably in the range of 0.5 to 3.5 mm, particularly preferably 1.5 to The range is 3.5 mm.

  The rubber composition for aqueous hoses of the present invention can be used for aqueous hoses such as radiator hoses, heater hoses, drain hoses and the like. An aqueous hose such as a radiator hose usually has an inner layer and an outer layer, and a reinforcing yarn layer is formed at the interface between the inner layer and the outer layer as necessary. The rubber composition for aqueous hoses of the present invention can be used for both the inner layer and the outer layer of the aqueous hoses.

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

  First, prior to the examples and comparative examples, the following materials were prepared.

[EPDM (component A)]
Esprene 505 manufactured by Sumitomo Chemical Co., Ltd.

[EPM (component A)]
Esplen 201 manufactured by Sumitomo Chemical Co., Ltd.

[Ethylene-octene resin (component B)]
<Ethylene-octene resin (B1)>
Dow Chemical Company, Engagement 8480 [Melt Flow Index (MFR) 1.0 g / 10 min, density 0.902 g / cm ³ ]

<Ethylene-octene resin (B2)>
Dow Chemical Company, Engagement 8110 [Melt Flow Index (MFR) 1.0 g / 10 min, density 0.870 g / cm ³ ]

<Ethylene-octene resin (B3)>
Engage 8540 manufactured by Dow Chemical Co., Ltd. [Melt Flow Index (MFR) 1.0 g / 10 min, density 0.908 g / cm ³ ]

[Ethylene-octene resin (for comparative example)]
<Ethylene-octene resin (B'1)>
Dow Chemical Company, Engage 8180 [Melt Flow Index (MFR) 0.5 g / 10 min, Density 0.863 g / cm ³ ]

<Ethylene-octene resin (B'2)>
Dow Chemical Co., Engage 8842 [Melt Flow Index (MFR) 1.0 g / 10 min, density 0.857 g / cm ³ ]

<Ethylene-octene resin (B'3)>
Dow Chemical Co., Engage 8402 [Melt Flow Index (MFR) 30.0 g / 10 min, Density 0.902 g / cm ³ ]

[Clay (component C)]
<Clay (C1)>
JIAOZOU TONGXING CHEMICAL, M212 clay (pH 7.1, particle size 4.5 μm)

<Clay (C2)>
RAY TC-400 (pH 8.2, particle size 8.7 μm), manufactured by Toyo Kasei Co., Ltd.

<Clay (C3)>
Iceberg K (pH 5.8, particle size 3.8 μm) manufactured by Shiraishi Calcium

[Clay (for comparative example)]
<Clay (C'1)>
Burgess # 10 (pH 5.0, particle size 1.5 μm)

<Clay (C'2)>
Kaolin TC-1000 (pH 9.3, particle size 1.1 μm), manufactured by Toyo Kasei Co., Ltd.

<Clay (C'3)>
HA Kaolin clay (pH 4.1, particle size 5.5 μm), manufactured by Maruo Calcium

[Surface treatment agent]
Diethylene glycol (DEG) (Mitsubishi Chemical Corporation, DEG)

[Vulcanization aid]
Made by Nippon Oil & Fats Co., Ltd. Beads stearic acid sakura

[Vulcanization aid]
Zinc oxide (Mitsui Mining & Mining, 2 types of zinc oxide)

〔Carbon black〕
FEF grade carbon black (manufactured by Tokai Carbon Co., Seast SO)

[Paraffin oil]
Sunflex 2280, manufactured by Nippon Oil Corporation

[Anti-aging agent]
2,2,4-trimethyl-1,2-dihydroquinoline (TMDQ) (Seiko Chemical Co., Ltd., Nonflex RD)

[Vulcanization accelerator]
Made by Sanshin Chemical Industry Co., Ltd., Sunseller TT-G
Sunseller TET-G, manufactured by Sanshin Chemical Industry Co., Ltd.
Sunseller CZ-G, manufactured by Sanshin Chemical Industry Co., Ltd.
Sunseller BZ-G, manufactured by Sanshin Chemical Industry Co., Ltd.

[Peroxide crosslinking agent]
Dicumyl peroxide (manufactured by NOF Corporation, Park Mill D-40)

[Co-crosslinking agent]
Ethylene glycol dimethacrylate (Seiko Chemical Co., Ltd., High Cloth ED)

[Vulcanizing agent (sulfur)]
Sulfax T-10, manufactured by Tsurumi Chemical Co., Ltd.

[Examples 1-11, Comparative Examples 1-8]
The components shown in Table 1 and Table 2 below were blended in the proportions shown in the same table, and kneaded using a Banbury mixer and a roll to prepare a rubber composition.

  Using the rubber compositions of Examples and Comparative Examples thus obtained, each characteristic was evaluated according to the following criteria. These results are shown in Tables 1 to 3 below.

[Processability]
When each rubber composition was used and inserted into a mandle, the processability was evaluated based on whether or not knitted meat (wrinkles) was generated.
<Evaluation>
○: No knitted meat (wrinkles) occurred. △: Knitted meat (wrinkles) occurred, but was in an acceptable range. X: Knitted meat (wrinkles) exceeded an allowable range.

[Amount of non-fossil fuel-derived material used]
About each rubber composition, the usage-amount of the non-fossil fuel origin material per material volume was evaluated according to the following reference | standard.
<Evaluation>
X: The amount of non-chemical stone fuel-derived material used per volume is less than 5 vol% ○: The amount of non-chemical stone fuel-derived material used per volume is 5 vol% or more

[Compression set]
Based on JIS K 6262, the compression set after thermal loading at 125 ° C. for 168 hours was evaluated.
<Evaluation>
○: Less than 75% Δ: More than 75%, less than 85% ×: More than 85%

[Tensile strength (TS)]
Each rubber composition was press vulcanized at 150 ° C. for 30 minutes to prepare a vulcanized rubber sheet having a thickness of 2 mm. Subsequently, a JIS No. 5 dumbbell was punched out and the tensile strength (TS) was evaluated according to JIS K 6251.
<Evaluation>
○: 12.0 MPa or more Δ: less than 12.0 MPa, 10.0 MPa or less x: less than 10.0 MPa

[Volume resistivity]
Each rubber composition was press vulcanized at 150 ° C. for 30 minutes to prepare a vulcanized rubber sheet having a thickness of 2 mm. Subsequently, the volume resistivity was measured according to JIS K 6271.
<Evaluation>
○: 1 × 10 ⁵ Ω · cm or more Δ: 1 × 10 ⁴ Ω · cm or more and less than 1 × 10 ⁵ Ω · cm ×: 1 × 10 ⁴ Ω · cm or less

  From the result of the said table | surface, all the Example products were favorable in workability, the usage-amount of a non-fossil fuel origin material, compression set, tensile strength, and volume resistivity.

  On the other hand, since the comparative example product does not use a specific ethylene-octene resin and a specific clay together with the ethylene-propylene rubber, the workability, the amount of non-fossil fuel-derived material used, and the compression set Any of tensile strength and volume resistivity was inferior.

  The rubber composition for aqueous hoses of the present invention can be used as a rubber composition for aqueous hoses such as radiator hoses, heater hoses, drain hoses and the like.

1 Hose 1a Bending part 2 Uneven thickness (Siwakobu)

Claims (7)

The component (B) and the component (C) are contained together with the following component (A), and the melt flow rate (MFR) at a temperature of 190 ° C. and a load of 2.16 kg of the component (B) is 1.0 g / 10 minutes. The rubber composition for an aqueous hose, wherein the density is 0.870 to 0.908 g / cm ³ , the pH of the component (C) is 5.5 or more, and the average particle size is 3.5 μm or more. object.
(A) Ethylene-propylene rubber.
(B) Ethylene-octene resin.
(C) Clay.   The rubber composition for an aqueous hose according to claim 1, wherein the component (C) is a surface-treated clay surface-treated with a polyhydric alcohol.   The rubber composition for an aqueous hose according to claim 1 or 2, wherein the content of the component (C) is 30 to 150 parts by weight with respect to 100 parts by weight of the component (A).   The rubber composition for an aqueous hose according to any one of claims 1 to 3, wherein the content of the component (B) is 5 to 30 parts by weight with respect to 100 parts by weight of the component (A).   A water-based hose having a bent shape obtained by vulcanization in a state where an unvulcanized hose is inserted into a bent pipe-shaped mandrel, wherein the water-based hose is according to any one of claims 1 to 4. An aqueous hose characterized by being formed using a rubber composition for an aqueous hose.   The water-based hose according to claim 5, wherein the thickness is equal to or less than 3.5 mm, and there is no uneven thickness (wrinkle) at the bent portion of the hose.   The water-based hose according to claim 5 or 6, wherein the water-based hose is any one selected from the group consisting of a radiator hose, a heater hose, and a drain hose.

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