JP2016011387A - Rubber composition and rubber product using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber composition which is excellent in cold resistance and extrusion moldability and can be suitably used as a cover rubber for an oil fence, and to provide a rubber product using the same.SOLUTION: The rubber composition of the present invention contains 10 to 30 pts.mass (inclusive) of a high styrene rubber and 5 to 20 pts.mass (inclusive) of a plasticizer, based on 100 pts.mass of a chloroprene rubber. The plasticizer has a freezing point of -50°C or lower and a solubility parameter of 8.0 to 10.0 (inclusive).

Description

  The present invention relates to a rubber composition and a rubber product using the rubber composition, and more particularly to a rubber composition suitably used as a cover rubber for an oil fence and a rubber product using the rubber composition.

  Conventionally, an oil fence membrane material (cover rubber) for an oil fence that is deployed in a water area in order to prevent diffusion of spilled oil in oil storage facilities such as refineries and tanker mooring facilities has been proposed (for example, patent literature) 1). This oil fence membrane material has a glass fiber composite cloth coated with Teflon (registered trademark) as a core material, and has a coating layer made of a rubber layer colored in orange around the core material. In this oil fence membrane material, by forming a rubber layer mainly composed of chloroprene rubber, which is excellent in elasticity, incombustibility, oil resistance and weather resistance, oil resistance, cold resistance, and resistance to oil fence membrane material are required. Various properties such as ozone and impact resistance are improved.

Japanese Patent Laid-Open No. 1-124839

  However, an oil fence cover rubber using chloroprene rubber is excellent in oil resistance and ozone resistance, but sufficient cold resistance may not always be obtained due to the crystallinity of chloroprene rubber. In general, the cover rubber for the oil fence is colored orange from the viewpoint of ensuring visibility. Therefore, as a reinforcing material for the cover rubber for the oil fence, white silica and carbon black can be used instead of carbon black. Clay or the like is used. However, silica and clay have weaker cover rubber reinforcing performance than carbon black, and there is a case in which the surface of the rubber is crushed during the production of the cover rubber by extrusion molding, and sufficient extrusion moldability may not be obtained.

  The present invention has been made in view of such circumstances, and has a rubber composition that is excellent in cold resistance and extrusion moldability and can be suitably used as a cover rubber for an oil fence, and a rubber product using the same. The purpose is to provide.

  The rubber composition of the present invention contains 10 to 30 parts by mass of a high styrene rubber and 5 to 20 parts by mass of a plasticizer with respect to 100 parts by mass of the chloroprene rubber. Has a freezing point of −50 ° C. or lower and a solubility parameter of 8.0 or higher and 10.0 or lower.

  According to this rubber composition, high styrene rubber excellent in heat resistance, aging resistance, and wear resistance compared to chloroprene rubber excellent in heat resistance, aging resistance, ozone resistance, weather resistance and heat resistance. Is contained in a predetermined amount, the hardness of the rubber composition is improved and the extrusion moldability is improved. In this rubber composition, since the freezing point and solubility parameter contain a plasticizer having a predetermined range, the compatibility between the plasticizer and the chloroprene rubber in the rubber composition is improved, and crystallization of the chloroprene rubber is prevented. It becomes possible to improve cold resistance. Therefore, it is possible to realize a rubber composition that is excellent in cold resistance and extrusion moldability and can be suitably used as a cover rubber for an oil fence.

  In the rubber composition of the present invention, the high styrene rubber is preferably at least one selected from the group consisting of a styrene butadiene copolymer and a butadiene / styrene / divinylbenzene copolymer.

  In the rubber composition of the present invention, the high styrene rubber preferably has a bound styrene content of 50% by mass or more and 70% by mass or less.

In the rubber composition of the present invention, the high styrene rubber preferably has a Mooney viscosity ML _{1 + 4} (100 ° C.) at 100 ° C. of 50 or more and 60 or less.

  In the rubber composition of the present invention, the plasticizer is preferably an adipic acid ester.

（式（１）中、Ｒ_１及びＲ_２は、それぞれ独立して炭素数５以上１２以下のアルキル基を表す。） In the rubber composition of the present invention, the plasticizer is preferably a compound represented by the following general formula (1).

(In Formula (1), R ₁ and R ₂ each independently represents an alkyl group having 5 to 12 carbon atoms.)

  In the rubber composition of the present invention, the chloroprene rubber is preferably a non-staining chloroprene rubber.

  The rubber product of the present invention is obtained by using the above rubber composition.

  In the rubber product of the present invention, an oil fence cover rubber is preferable.

  The rubber product of the present invention preferably contains a coloring component.

  ADVANTAGE OF THE INVENTION According to this invention, it is excellent in cold resistance and extrusion moldability, The rubber composition which can be used suitably as cover rubber for oil fences, and a rubber product using the same are realizable.

FIG. 1 is a schematic cross-sectional view of an oil fence in which a rubber composition according to an embodiment of the present invention is used.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited to the following embodiment, It can implement by changing suitably.

  First, a rubber product manufactured using the rubber composition according to the present embodiment will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view of an oil fence in which the rubber composition according to the present embodiment is used. As shown in FIG. 1, an oil fence 1 according to the present embodiment is deployed in a water area such as the ocean and is used for preventing the diffusion of oil such as heavy oil that has flowed into the water area. The oil fence 1 includes a float portion 11 that floats on the water surface, a skirt portion 12 that is connected to the lower end of the float portion 11 via a tension belt (not shown), extends downward from the float portion 11, and is disposed in the sea. Is provided. A chain 13 or the like is disposed at the lower end of the skirt portion 12, and the skirt portion 12 is deployed in water by the chain 13.

  The float unit 11 includes a core material 111 such as a glass fiber composite cloth coated with Teflon (registered trademark), and a cover rubber 112 that covers the core material 111. The rubber composition according to the present embodiment is suitably used as the cover rubber 112 of the oil fence 1. Since the cover rubber 112 is exposed on the surface of the water and is in contact with seawater and heavy oil, impact resistance, ozone resistance, water resistance, and oil resistance are required. Moreover, since the oil fence 1 is used also in a cold region etc., the cover rubber 112 needs to be cold resistant. The rubber composition according to the present embodiment can be applied to various rubber products other than the cover rubber 112 of the oil fence 1. Hereinafter, the rubber composition according to the present embodiment will be described.

The rubber composition according to the present embodiment contains 10 to 30 parts by mass of a high styrene rubber and 5 to 20 parts by mass of a plasticizer with respect to 100 parts by mass of the chloroprene rubber. The plasticizer has a freezing point of −50 ° C. or lower and a solubility parameter of 8.0 or higher and 10.0 or lower. Here, the freezing point is a freezing point measured by a measuring method based on JIS K6750: 1999. The solubility parameter (SP) is a value calculated using the following formula (A).
SP = dΣG / M (d: density, G: molecular attractive constant, M: molecular weight) Formula (A)

  According to this rubber composition, high styrene rubber excellent in heat resistance, aging resistance, and wear resistance compared to chloroprene rubber excellent in heat resistance, aging resistance, ozone resistance, weather resistance and heat resistance. Therefore, the hardness of the rubber composition is improved and the extrusion moldability is improved. In this rubber composition, since the freezing point and the solubility parameter contain a plasticizer having a predetermined range, the compatibility between the plasticizer and the chloroprene rubber in the rubber composition is improved, and the rubber composition can be used even at low temperatures. It is possible to prevent chloroprene rubber from being crystallized at the same time, and the cold resistance is improved. Therefore, it is possible to realize a rubber composition excellent in cold resistance extrusion moldability and a rubber product using the rubber composition. Hereinafter, the components of the rubber composition according to the present embodiment will be described in detail.

<Chloroprene rubber>
As the chloroprene rubber (CR), various chloroprene rubbers can be used as long as the effects of the present invention are exhibited. As the chloroprene rubber, non-contaminating chloroprene rubber is preferable from the viewpoint of ensuring the visibility of a rubber product obtained using the rubber composition. Here, the non-contaminating chloroprene rubber is a rubber which does not cause discoloration of the vulcanized rubber due to the anti-aging agent added in the polymer production stage under the environment of heat, pressure or sunlight irradiation. In addition, as non-contaminating chloroprene rubber, for example, Denkachloroprene (registered trademark) S-41 may be mentioned. Examples of the contaminating chloroprene rubber include Denkachloroprene (registered trademark) PM-40.

  As a compounding quantity of chloroprene rubber, 20 mass% or more and 70 mass% or less are preferable with respect to the whole rubber composition from heat resistance, aging resistance, ozone resistance, a weather resistance, and a heat resistant viewpoint.

  The rubber composition according to the present embodiment may contain a diene polymer other than chloroprene rubber as long as the effects of the present invention are exhibited. Examples of the diene polymer include those capable of being vulcanized with sulfur having the property of forming a crosslinked structure through sulfur. Examples of the diene polymer include natural rubber (NR), isoprene rubber (IR), styrene butadiene rubber (SBR) other than high styrene rubber, acrylonitrile-butadiene rubber (NBR), and ethylene-propylene-diene rubber (EPDM). Is mentioned. By using these, various physical properties required for a cover rubber for an oil fence using a rubber composition can be exhibited at a high level. Among these, from the viewpoint of heat resistance, aging resistance, ozone resistance, weather resistance, and heat resistance, styrene butadiene rubber (SBR) other than high styrene rubber, acrylonitrile-butadiene rubber (NBR), ethylene-propylene-diene rubber (EPDM) is preferred. These diene polymers may be used alone or in combination of two or more.

<High styrene rubber>
The rubber composition according to the present embodiment contains a high styrene rubber. High styrene rubber is a copolymer of styrene and conjugated diene and has a bound styrene content of 40% by mass or more. Examples of styrene include o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1,3-dimethylstyrene, and α-methylstyrene. Examples of conjugated dienes include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, and the like. Of these, 1,3-butadiene is preferred. By containing this high styrene rubber, the hardness of the rubber composition is improved and the impact resistance and extrusion moldability are improved. The high styrene rubber is at least one high styrene rubber selected from the group consisting of a styrene butadiene copolymer and a butadiene-styrene-divinylbenzene copolymer from the viewpoint of impact resistance and extrusion moldability of the rubber composition. Is preferred.

  The content of the high styrene rubber is 10 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the chloroprene rubber from the viewpoint of impact resistance and extrusion moldability of the rubber composition. If the content of the high styrene rubber is 10 parts by mass or more with respect to 100 parts by mass of the chloroprene rubber, the impact resistance of the rubber composition is good, and if it is 30 parts by mass or less, the extrudability of the rubber composition. Becomes better. The content of the high styrene rubber is preferably 12.5 parts by mass or more, more preferably 15 parts by mass or more, and 17.5 parts by mass with respect to 100 parts by mass of the chloroprene rubber from the viewpoint of further improving the above-described effects. The above is more preferable, 27.5 parts by mass or less is preferable, 25 parts by mass or less is more preferable, and 22.5 parts by mass or less is still more preferable. Considering the above, the content of the high styrene rubber is preferably 12.5 parts by mass or more and 27.5 parts by mass or less, more preferably 15 parts by mass or more and 25 parts by mass or less, with respect to 100 parts by mass of the chloroprene rubber. 17.5 parts by mass or more and 22.5 parts by mass or less is more preferable.

  The amount of bound styrene of the high styrene rubber is preferably 50% by mass or more, more preferably 55% by mass or more, and preferably 70% by mass or less, from the viewpoint of improving the impact resistance of the rubber composition, and 67.5% by mass. % Or less is more preferable.

From the viewpoint of improving the impact resistance of the rubber composition, the high styrene rubber preferably has a Mooney viscosity ML _{1 + 4} (100 ° C.) at 100 ° C. of 50 or more, more preferably 52.5 or more, and 60 The following are preferable, and those of 57.5 or less are more preferable. Mooney viscosity ML _{1 + 4} (100 ° C.) at 100 ° C. is measured at 100 ° C. according to JIS K 6300-1: 2013.

<Plasticizer>
The rubber composition according to the present embodiment contains a plasticizer having a freezing point of −50 ° C. or lower and a solubility parameter of 8.0 or higher and 10.0 or lower. When the freezing point of a plasticizer is -50 degrees C or less, the embrittlement temperature of a rubber composition falls and the cold resistance of a rubber composition improves. Further, since the solubility parameter of the plasticizer is 8.0 or more and 10.0 or less, compatibility between the rubber component such as chloroprene rubber and the plasticizer is improved, so that the embrittlement temperature of the rubber composition is lowered and cold resistance is reduced. Improves. The freezing point of the plasticizer is preferably −55 ° C. or lower, preferably −60 ° C. or lower, more preferably −100 ° C. or higher, and more preferably −80 ° C. or higher. The solubility parameter of the plasticizer is preferably 8.2 or more, more preferably 8.5 or more, and preferably 9.75 or less, more preferably 9.5 or less.

  Examples of the plasticizer include adipic acid esters, azelaic acid esters, and sebacic acid ester compounds. Among these, as the plasticizer, an adipic acid ester is preferable from the viewpoint of cold resistance and extrusion moldability of the rubber composition.

（式（１）中、Ｒ_１及びＲ_２は、それぞれ独立して炭素数５以上１２以下のアルキル基を表す。） In the rubber composition according to the present embodiment, the plasticizer is preferably a compound represented by the following general formula (1) from the viewpoint of cold resistance and extrusion moldability of the rubber composition.

(In Formula (1), R ₁ and R ₂ each independently represents an alkyl group having 5 to 12 carbon atoms.)

In the general formula (1), R ₁ is more preferably an alkyl group having 7 to 11 carbon atoms. Examples of R ₁ include a pentyl group, hexyl group, 2-ethylhexyl group, heptyl group, octyl group, nonyl group, isononyl group, decyl group, isodecyl group, undecyl group, and dodecyl group. Among these, 2-ethylhexyl group, heptyl group, octyl group, nonyl group, isononyl group, decyl group and isodecyl group are preferable, 2-ethylhexyl group, octyl group, isononyl group and isodecyl group are more preferable, and 2-ethylhexyl. Groups are even more preferred.

In the general formula (1), R ₂ is more preferably an alkyl group having 7 to 11 carbon atoms. Examples of R ₂ include a pentyl group, hexyl group, 2-ethylhexyl group, heptyl group, octyl group, nonyl group, isononyl group, decyl group, isodecyl group, undecyl group, and dodecyl group. Among these, 2-ethylhexyl group, heptyl group, octyl group, nonyl group, isononyl group, decyl group and isodecyl group are preferable, 2-ethylhexyl group, octyl group, isononyl group and isodecyl group are more preferable, and 2-ethylhexyl. Groups are more preferred.

  Examples of the compound represented by the general formula (1) include dipentyl adipate, dihexyl adipate, bis-2-ethylhexyl adipate (DOA), diheptyl adipate, dioctyl adipate, dinonyl adipate, diisononyl adipate , Didecyl adipate, diisodecyl adipate, dipentyldiundecyl adipate, didodecyl adipate, and the like. Among these, bis-2-ethylhexyl adipate, diheptyl adipate, dioctyl adipate, dinonyl adipate, diisononyl adipate, didecyl adipate, and diisodecyl adipate are preferred, bis-2-ethylhexyl adipate, dioctyl adipate , Diisononyl adipate and diisodecyl adipate are more preferable, and bis-2-ethylhexyl adipate is still more preferable. These plasticizers may be used alone or in combination of two or more.

  The content of the plasticizer is 5 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the chloroprene rubber from the viewpoint of cold resistance and extrusion moldability of the rubber composition. If the content of the plasticizer is 5 parts by mass or more with respect to 100 parts by mass of the chloroprene rubber, the cold resistance of the rubber composition is good, and if it is 20 parts by mass or less, the extrudability of the rubber composition is good. It becomes. The content of the plasticizer is preferably 6 parts by mass or more, more preferably 7 parts by mass or more, still more preferably 8 parts by mass or more with respect to 100 parts by mass of the chloroprene rubber, from the viewpoint of further improving the above-described effects. Moreover, 18 mass parts or less are preferable, 17.5 mass parts or less are more preferable, and 15 mass parts or less are still more preferable. Considering the above, the content of the plasticizer is preferably 6 parts by mass or more and 18 parts by mass or less, more preferably 7 parts by mass or more and 17.5 parts by mass or less, and 8 parts by mass with respect to 100 parts by mass of the chloroprene rubber. More preferred is 15 parts by mass or less.

  In the rubber composition which concerns on this Embodiment, you may contain other plasticizers other than the plasticizer mentioned above in the range with the effect of this invention. Examples of other plasticizers include dioctyl phthalate (DOP), dibutyl phthalate (DBP), isodecyl succinate, diethylene glycol dibenzoate, pentaerythritol ester, butyl oleate, methyl acetylricinoleate, tricresyl phosphate, trioctyl phosphate, Examples include trimellitic acid ester, propylene glycol adipate polyester, butylene glycol adipate polyester, and naphthene oil. These may be used alone or in combination of two or more.

<Coloring ingredients>
In the rubber composition which concerns on this Embodiment, it is preferable to contain a coloring component from a viewpoint which the visibility at the time of setting it as rubber products, such as cover rubber | gum for oil fences, improves. As the coloring component, an orange coloring component such as Pigment Orange 16 (trade name: PIGMOTEX (registered trademark) ORANGE, manufactured by Sanyo Dye) is preferable from the viewpoint of visibility.

<Vulcanizing agent>
The rubber composition according to the present embodiment preferably contains a metal oxide as a vulcanizing agent and sulfur. Examples of metal oxides include oxides such as beryllium, magnesium, zinc, calcium, barium, germanium, titanium, tin, zirconium, antimony, vanadium, bismuth, molybdenum, tungsten, tellurium, selenium, iron, nickel, cobalt, and osmium. Hydroxides and the like can be used. Among these metal compounds, calcium oxide, zinc oxide, antimony dioxide, antimony trioxide, and magnesium oxide are particularly preferable because of their high vulcanization effect. In addition, you may use these vulcanizing agents in combination of 2 or more types. Sulfur includes powdered sulfur, precipitated sulfur, highly dispersible sulfur, surface treated sulfur, and insoluble sulfur.

  The content of sulfur is preferably 0.5 parts by mass or more and 5.0 parts by mass or less, and 0.55 parts by mass or more with respect to 100 parts by mass of the chloroprene rubber, from the viewpoint of extrusion moldability and cold resistance of the rubber composition. 3.0 mass parts or less are more preferable, and 0.6 mass part or more and 2.0 mass parts or less are still more preferable.

  The rubber composition according to the present embodiment may contain a vulcanizing agent other than metal oxide and sulfur within the range where the effects of the present invention are exhibited. Examples of the vulcanizing agent other than the metal oxide and sulfur include vulcanizing agents such as sulfur-based, organic peroxide-based, phenolic resin, and quinonedioxime. These may be used alone or in combination of two or more. Examples of the sulfur-based vulcanizing agent include tetramethyl thiuram disulfide (TMTD), tetraethyl thiuram disulfide (TETD), tetrabutyl thiuram disulfide (TBTD), dipentamethylene thiuram tetrasulfide (DPTT), tetrabenzyl thiuram disulfide, and Examples thereof include organic sulfur-containing compounds such as dimorpholine disulfide and alkylphenol disulfide.

  Examples of the organic peroxide vulcanizing agent include dicumyl peroxide, benzoyl peroxide, t-butyl hydroperoxide, 2,4-dichlorobenzoyl peroxide, 2,5-dimethyl-2,5-di ( t-butylperoxy) hexane, 2,5-dimethylhexane-2,5-di (peroxylbenzoate).

  Examples of other vulcanizing agents include resins such as phenol resins, p-quinonedioxime, p-dibenzoylquinonedioxime, poly-p-dinitrosobenzene, and methylenedianiline.

<Vulcanization accelerator>
The rubber composition according to the present embodiment preferably further contains a vulcanization accelerator. Examples of the vulcanization accelerator include an aldehyde-ammonia vulcanization accelerator, an aldehyde-amine vulcanization accelerator, a thiourea vulcanization accelerator, a guanidine vulcanization accelerator, a thiazole vulcanization accelerator, and sulfene. Examples include amide vulcanization accelerators, thiuram vulcanization accelerators, dithiocarbamate vulcanization accelerators, and xanthate vulcanization accelerators. These may be used alone or in combination of two or more.

  Examples of the thiuram vulcanization accelerator include tetramethylthiuram monosulfide (TS) and tetramethylthiuram disulfide (TT). Examples of the guanidine vulcanization accelerator include diphenyl guanidine. Examples of the sulfenamide vulcanization accelerator include Nt-butylbenzothiazole-2-sulfenamide. Examples of the thiourea vulcanization accelerator include ethylene thiourea.

  The content of the vulcanization accelerator is preferably 0.5 parts by mass or more and 3.5 parts by mass or less, based on 100 parts by mass of the chloroprene rubber, from the viewpoint of extrusion moldability and cold resistance of the rubber composition, and is preferably 0.75. The mass is more preferably no less than 3.0 parts by mass and even more preferably no less than 1.0 parts by mass and no greater than 2.5 parts by mass.

[Other additives]
Moreover, the rubber composition can contain other additives as necessary within the range where the effects of the present invention are exhibited. Other additives include, for example, fillers, softeners, anti-aging agents, organic activators, antioxidants, antistatic agents, flame retardants, crosslinking accelerators, vulcanization retarders, ozone degrading agents, processes An oil (aroma oil) and an adhesion aid are mentioned.

  Examples of the filler include carbon black, silica (white carbon), clay, talc, mica (mica), and diatomaceous earth. These may be used alone or in combination of two or more. As carbon black, it can select suitably according to a use and can be used. As the carbon black, ISAF class, FEF class and the like are preferable. Examples of the silica include crystalline silica, precipitated silica, amorphous silica (for example, high-temperature treated silica), fumed silica, calcined silica, precipitated silica, pulverized silica, and fused silica. In particular, silica is known to produce carbon gel (bound rubber) like carbon black, and can be suitably used as necessary. Examples of the clay include hard clay, waxite clay, kaolin clay, and calcined clay.

  Specific examples of the softener include aroma oil, naphthene oil, paraffin oil, petroleum resin, vegetable oil, and liquid rubber. These may be used alone or in combination of two or more.

  Examples of the antioxidant include N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine (6PPD), N, N′-dinaphthyl-p-phenylenediamine (DNPD), and N-isopropyl. Amine-based antioxidants such as —N′-phenyl-p-phenylenediamine (IPPD) and 2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD), and styrenated phenol (SP), 2, Phenolic anti-aging agents such as 6-di-t-butyl-4-methylphenol, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2,5-di-t-butylhydroquinone Can be mentioned. These may be used alone or in combination of two or more. Further, from the viewpoint of improving the visibility when a rubber product such as a cover rubber for an oil fence is improved, a non-fouling phenol-based anti-aging agent is preferable.

  Examples of the organic active agent include stearic acid, oleic acid, lauric acid, and zinc stearate. These may be used alone or in combination of two or more.

  Examples of the antistatic agent include quaternary ammonium salts; hydrophilic compounds such as polyglycols and ethylene oxide derivatives.

  Examples of the flame retardant include chloroalkyl phosphate, dimethyl / methylphosphonate, bromine / phosphorus compound, ammonium polyphosphate, neopentyl bromide-polyether, and brominated polyether. Examples of non-halogen flame retardants include tricresyl phosphate and diphenyl cresyl phosphate.

  As the crosslinking accelerating aid, general rubber auxiliaries can be used together. As the rubber aid, for example, stearic acid, oleic acid, or a Zn salt thereof can be used.

  Examples of the adhesion assistant include triazine thiol compounds (for example, 2,4,6-trimercapto-1,3,5-triazine, 6-butylamino-2,4-dimercapto-1,3,5-triazine). ), Resorcin, cresol, resorcin-formalin latex, monomethylol melamine, monomethylol urea, ethylene maleimide, cobalt naphthenate, cobalt stearate, cobalt versatate, and cobalt dodecanoate. These may be used alone or in combination of two or more.

<Method for producing rubber composition>
The rubber composition according to the present embodiment can be produced by a conventionally known production method. As a manufacturing method of the rubber composition according to the present embodiment, for example, first, the chloroprene rubber, the high styrene rubber, the plasticizer, and the various additives as necessary are blended. And the manufacturing method knead | mixed using a Banbury mixer, closed mixers, such as a kneader, kneading roll machines, such as a roll, an extruder, a twin screw extruder, etc. are mentioned.

  Hereinafter, the present invention will be described in more detail with reference to examples made to clarify the effects of the present invention. In addition, this invention is not limited at all by the following examples and comparative examples.

<1. Preparation of rubber composition>
(Example 1)
To 100 parts by mass of chloroprene rubber (trade name “Denka Chloroprene (registered trademark), model number: S-41”, manufactured by Denki Kagaku Kogyo Co., Ltd.), 20 parts by mass of high styrene rubber (trade name “NIPOL (registered trademark), Model No .: 2057-S ”, manufactured by Nippon Zeon Co., Ltd., bound styrene content 60% by mass), 0.9 part by mass of sulfur (manufactured by Hosoi Chemical Co., Ltd.), and 8 parts by mass of adipic acid as a plasticizer-2- Ethylhexyl (trade name “DIACIZER DOA”, manufactured by Mitsubishi Kasei Vinyl Co., Ltd.) and 0.75 part by mass of thiuram vulcanization accelerator (tetramethylthiuram monosulfide, trade name: Sunseller TS-G, manufactured by Sanshin Chemical Industry Co., Ltd.) ), 0.75 part by mass of a guanidine vulcanization accelerator (di-o-tolylguanidine, trade name “Soccinol (registered trademark), model number: DT-O”, manufactured by Sumitomo Chemical Co., Ltd.), and 30 Part by weight of silica (trade name “Nippseal AQ”, manufactured by Tosoh Silica Co.), 30 parts by weight of clay (trade name “Suprex Clay”, manufactured by Kentucky Tennessee Clay Company), and 20 parts by weight of heavy Calcium carbonate (trade name “Super 1500”, manufactured by Maruo Calcium Co., Ltd.), 2 parts by mass of magnesium oxide (trade name “Kyowa Mag 150”, manufactured by Kyowa Chemical Industry Co., Ltd.), and 1.5 parts by weight of anti-aging agent (product) Name "NOCRACK SP", manufactured by Ouchi Shinsei Chemical Industry Co., Ltd., 3 parts by weight of coloring components (trade name "PIGMOTEX (registered trademark) ORANGE", manufactured by Sanyo Dye) and 3 parts by weight of stearic acid (trade name) "Stearic acid YR" (manufactured by NOF Corporation) and 5 parts by mass of zinc oxide (3 types of zinc oxide, manufactured by Shodo Chemical Industry Co., Ltd.) are blended and kneaded with a Banbury Chemiser to produce a rubber composition It was produced. The amount of each component is shown in Table 1 below.

(Example 2)
A rubber composition was prepared in the same manner as in Example 1 except that the high styrene rubber was changed to (trade name “JSR 0061”, manufactured by JSR Corporation, 66% by mass of bound styrene). The amount of each component is shown in Table 1 below.

(Example 3)
A rubber composition was produced in the same manner as in Example 2 except that the amount of the plasticizer was 15 parts by mass. The amount of each component is shown in Table 1 below.

(Comparative Example 1)
For 100 parts by mass of chloroprene rubber (trade name “Denka Chloroprene (registered trademark), model number: EM-40”, manufactured by Denki Kagaku Kogyo Co., Ltd., non-sulfur modified chloroprene rubber, Mooney viscosity (ML _{1 + 4} , 100 ° C.) 48), 15 parts by mass of a tricresyl phosphate (made by Daihachi Chemical Industry Co., Ltd.) as a plasticizer and 0.5 parts by mass of an imidazoline-based vulcanization accelerator (2-mercaptoimidazoline, trade name “Sunmix 22-80E”, Sanshin Chemical Co., Ltd.), 80 parts by mass of clay (trade name “Suprex Clay”, manufactured by Kentucky Tennessee Clay Company), 2 parts by weight of magnesium oxide (trade name “Kyowa Mag 150 (registered trademark)”, Kyowa Chemical Industry Co., Ltd.), 1.5 parts by mass of an anti-aging agent (trade name “NOCRACK SP”, manufactured by Ouchi Shinsei Chemical Co., Ltd.), and 1 part by mass 3 parts by weight or less of coloring components (trade name “PIGMOTEX (registered trademark) ORANGE” manufactured by Sanyo Dye Co., Ltd.) and 0.5 parts by weight of stearic acid (trade name “stearic acid YR” manufactured by NOF Corporation) 5 parts by mass of zinc oxide (three types of zinc oxide, manufactured by Shodo Chemical Industry Co., Ltd.) were blended and kneaded with a Banbury Kimiser to prepare a rubber composition. The amount of each component is shown in Table 1 below.

(Comparative Example 2)
0.9 parts by mass of sulfur (made by Hosoi Chemical Co., Ltd.) and 8 parts per 100 parts by mass of chloroprene rubber (trade name “Denka Chloroprene (registered trademark), model number: S-41”, manufactured by Denki Kagaku Kogyo) Butyl oleate (manufactured by Wako Pure Chemical Industries, Ltd.) as a plasticizer in parts by mass and 0.75 part by mass of a thiuram vulcanization accelerator (tetramethylthiuram monosulfide, trade name: Sunseller TS-G, Sanshin Chemical) Kogyo Co., Ltd.), 0.75 part by mass of a guanidine vulcanization accelerator (di-o-tolylguanidine, trade name “Soccinol (registered trademark), model number: DT-O”, manufactured by Sumitomo Chemical Co., Ltd.), 100 Part by mass of talc (trade name “MISTORON VAPOR”, manufactured by Nippon Mystron), 2 parts by weight of magnesium oxide (trade name “Kyowa Mag 150 (registered trademark)”, manufactured by Kyowa Chemical Industry Co., Ltd.), 1.5 mass Anti-aging agent (trade name “NOCRACK SP”, Ouchi Shinsei Chemical Co., Ltd.), 3 parts by weight of coloring components (trade name “PIGMOTEX (registered trademark) ORANGE”, manufactured by Sanyo Dye) and 3 parts by weight of stearin An acid (manufactured by NOF Corporation) and 5 parts by mass of zinc oxide (3 types of zinc oxide, manufactured by Shodo Chemical Industry Co., Ltd.) were blended and kneaded with a Banbury Kimiser to prepare a rubber composition. The amount of each component is shown in Table 1 below.

(Comparative Example 3)
A rubber composition was prepared in the same manner as in Example 1 except that the plasticizer was replaced with tricresyl phosphate (manufactured by Daihachi Chemical Industry Co., Ltd.). The amount of each component is shown in Table 1 below.

(Comparative Example 4)
A rubber composition was produced in the same manner as in Comparative Example 3 except that the blending amount of the high styrene rubber was 40 parts by mass. The amount of each component is shown in Table 1 below.

(Comparative Example 5)
A rubber composition was prepared in the same manner as in Comparative Example 2 except that 40 parts by mass of high styrene rubber (trade name “JSR 0061”, manufactured by JSR Corporation, 66 mass% of bound styrene) was blended. The amount of each component is shown in Table 1 below.

(Comparative Example 6)
A rubber composition was produced in the same manner as in Example 2 except that the blending amount of the high styrene rubber was 40 parts by mass. The amount of each component is shown in Table 1 below.

なお、表１に記載した各成分の詳細は以下のとおりである。
・クロロプレンゴムＡ：商品名「デンカクロロプレン（登録商標）、型番：Ｓ−４１」、電気化学工業社製
・クロロプレンゴムＢ：商品名「デンカクロロプレン（登録商標）、型番：ＥＭ−４０」、電気化学工業社製、非硫黄変性クロロプレンゴム、ムーニー粘度（ＭＬ１＋４，１００℃）４８
・ハイスチレンゴムＡ：商品名「ＮＩＰＯＬ（登録商標）、型番：２０５７−Ｓ」、日本ゼオン社製、結合スチレン量６０質量％
・ハイスチレンゴムＢ：商品名「ＪＳＲ ００６１」、ＪＳＲ社製、結合スチレン量６６質量％
・可塑剤Ａ：アジピン酸−２−エチルヘキシル、商品名「ＤＩＡＣＩＺＥＲ ＤＯＡ」、三菱化成ビニル社製
・可塑剤Ｂ：トリクレジルホスフェート、商品名「ＴＣＰ」、大八化学工業社製
・可塑剤Ｃ：オレイン酸ブチル、和光純薬工業社製
・硫黄：細井化学工業社製
・加硫促進剤Ａ：テトラメチルチウラムモノスルフィド、商品名：サンセラーＴＳ−Ｇ、三新化学工業社製)
・加硫促進剤Ｂ：ジ−ｏ−トリルグアニジン、商品名「ソクシノール（登録商標） ＤＴ−Ｏ」、住友化学社製
・加硫促進剤Ｃ：２−メルカプトイミダゾリン、商品名「サンミックス 型番：２２−８０Ｅ」、三新化学工業社製
・シリカ：商品名「ニツプシールＡＱ」、東ソ−・シリカ社製
・クレー：商品名「Ｓｕｐｒｅｘ Ｃｌａｙ」、ケンタッキーテネシークレイカンパニー社製
・タルク：商品名：「ＭＩＳＴＲＯＮ ＶＡＰＯＲ」、日本ミストロン社製
・重質炭酸マグネシウム：商品名「スーパー１５００」、丸尾カルシウム社製
・酸化マグネシウム：商品名「キョーワマグ１５０（登録商標）」、協和化学工業社製
・老化防止剤：商品名：「ノクラックＳＰ」、大内新興化学工業社製
・着色成分：商品名「ＰＩＧＭＯＴＥＸ ＯＲＡＮＧＥ（登録商標）」、山陽色素社製
・ステアリン酸：商品名「ステアリン酸ＹＲ」、日油社製
・酸化亜鉛：酸化亜鉛３種、正同化学工業社製

In addition, the detail of each component described in Table 1 is as follows.
Chloroprene rubber A: Trade name “Denka Chloroprene (registered trademark), model number: S-41”, manufactured by Denki Kagaku Kogyo Co., Ltd. • Chloroprene rubber B: Trade name “Denka Chloroprene (registered trademark), model number: EM-40”, Electric Chemical industry, non-sulfur modified chloroprene rubber, Mooney viscosity (ML1 + 4,100 ° C.) 48
High styrene rubber A: trade name “NIPOL (registered trademark), model number: 2057-S”, manufactured by Nippon Zeon Co., Ltd., bound styrene content 60% by mass
High styrene rubber B: Trade name “JSR 0061”, manufactured by JSR, 66% by mass of bound styrene
・ Plasticizer A: 2-ethylhexyl adipate, trade name “DIACIZER DOA”, manufactured by Mitsubishi Kasei Vinyl Co., Ltd. ・ Plasticizer B: tricresyl phosphate, trade name “TCP”, manufactured by Daihachi Chemical Industries, Ltd. ・ Plasticizer C : Butyl oleate, manufactured by Wako Pure Chemical Industries, Ltd., sulfur: manufactured by Hosoi Chemical Co., Ltd., vulcanization accelerator A: tetramethylthiuram monosulfide, trade name: Sunseller TS-G, manufactured by Sanshin Chemical Industry Co., Ltd.)
・ Vulcanization accelerator B: Di-o-tolylguanidine, trade name “Soccinol (registered trademark) DT-O”, manufactured by Sumitomo Chemical Co., Ltd. ・ Vulcanization accelerator C: 2-mercaptoimidazoline, trade name “Sunmix Model number: 22-80E ”, manufactured by Sanshin Chemical Industry Co., Ltd., silica: trade name“ Nippseal AQ ”, manufactured by Tosoh Silica Co., Ltd., clay: trade name“ Suprex Clay ”, manufactured by Kentucky Tennessee Clay Company, Inc., talc: trade name: “MISTON VAPOR”, manufactured by Nippon Mystron Co., Ltd., heavy magnesium carbonate: trade name “Super 1500”, manufactured by Maruo Calcium Co., Ltd., magnesium oxide: trade name “Kyowa Mag 150 (registered trademark)”, manufactured by Kyowa Chemical Industry Co., Ltd. : Product name: “NOCRACK SP”, manufactured by Ouchi Shinsei Chemical Co., Ltd./Coloring component: Product name “PIGMOTEX ORANGE” Registered trademark) ", Sanyo Color Works Co., Ltd. Stearic acid: trade name" stearic acid YR ", manufactured by NOF Corporation Zinc oxide: or zinc oxide 3, Seido Chemical Industry Co., Ltd.

<2. Evaluation of rubber composition>
Each rubber composition obtained in Examples 1 to 3 and Comparative Examples 1 to 6 was evaluated as follows.

<Hardness>
The rubber composition was vulcanized for 45 minutes under a surface pressure of 3.0 MPa using a press molding machine at 148 ° C. to prepare a vulcanized sheet having a thickness of 2 mm. Using this vulcanized sheet, the hardness was measured using a type A durometer in accordance with JIS K 6253-3: 2012. The evaluation results are shown in Table 2 below.
Good: 65 or more and 80 or less Defect: Less than 65 and over 80

<Tensile strength (TB)>
The rubber composition was vulcanized for 45 minutes under a surface pressure of 3.0 MPa using a press molding machine at 148 ° C. to prepare a vulcanized sheet having a thickness of 2 mm. From this sheet, a JIS No. 3 dumbbell-shaped test piece (2 mm dumbbell-shaped test piece (dumbbell-shaped No. 3 type)) was punched out to produce a dumbbell-shaped test piece. Tensile strength was measured at a tensile speed of 500 mm / min according to JIS K6251: 2010 using the produced dumbbell-shaped test piece. The evaluation criteria are shown below, and the evaluation results are shown in Table 2 below.
Good: 11.0 MPa or more Poor: Less than 11.0 MPa

<Elongation at break (EB)>
The elongation at break (%) was measured according to JIS K6251-2010 using the dumbbell-shaped test piece. The evaluation criteria are shown below, and the evaluation results are shown in Table 2 below.
Good: 550% or more Bad: Less than 550%

<Cold resistance>
In accordance with “Low Temperature Impact Embrittlement Test” in JIS K6261-2006 “Vulcanized Rubber and Thermoplastic Rubber—How to Obtain Low Temperature Properties”, a test piece was prepared from the vulcanized rubber of each rubber composition. The temperature at which 50% of the total number of specimens breaks (embrittlement temperature) was measured when the specimen was subjected to impact bending under the conditions. The evaluation criteria are shown below, and the evaluation results are shown in Table 2 below.
Good: −30 ° C. or lower Poor: Over −30 ° C.

<Extrudability>
Extrudability was evaluated by a garbage die extrusion test. The vulcanized rubber composition was extruded using an extruder (single-axis barrel diameter 20 mm, rotation speed 30 rpm, barrel temperature 60 ° C., head temperature 80 ° C.) with a garbage die attached to the tip. And according to ASTM D2230-77 A method (garbe die extrusion test, scoring method A), the state of the obtained extruded product was evaluated. Obtained die swell (%) for the obtained extruded product, as well as swell / bubble, smoothness of the surface of the extruded product, sharpness of corners other than 30 ° edge, and continuity of 30 ° edge Each was evaluated with a maximum of 4 points and a minimum of 1 point. The evaluation criteria are shown below, and the evaluation results are shown in Table 2 below.
Good: 3.0 or more Poor: Less than 3.0

<Oil resistance>
The test piece of vulcanized rubber composition was used in accordance with the method described in the immersion test of JIS K 6258: 2003, and immersed in the test fuel oil B to change the volume (%). Was measured. The evaluation criteria are shown below, and the evaluation results are shown in Table 2 below.
○: Volume change rate is 150 or less ×: Volume change rate exceeds 150

<Ozone resistance>
After vulcanizing the rubber composition, a strip-shaped test piece was punched out to prepare a test piece. In accordance with JIS K6259: 2004, the test piece was placed under the conditions of an elongation strain of 20%, an ozone concentration of 100 pphm, and a temperature of 40 ° C. for 168 hours, and the appearance of the test piece was visually confirmed after 168 hours. The evaluation criteria are shown below, and the evaluation results are shown in Table 2 below.
○: No cracking,
X: Crack of 3 mm or more occurred

  As can be seen from Tables 1 and 2, when the chloroprene rubber contains a predetermined amount of high styrene rubber and also contains the plasticizer A having a freezing point and a solubility parameter within a predetermined range, both the hardness and tensile strength It turns out that the rubber composition which satisfy | fills the various characteristics required as cover rubber | gum for oil fences, such as intensity | strength, breaking elongation, cold resistance, extrusion moldability, oil resistance, and ozone resistance is obtained (Example 1-Example). 3). On the other hand, when no high styrene rubber is contained, the hardness tends to decrease (Comparative Example 1 and Comparative Example 2). Moreover, when there is too much content of high styrene rubber, it turns out that there exists a tendency for break elongation to fall (Comparative Example 4 to Comparative Example 6). In addition, it can be seen that in the case of containing a plasticizer whose freezing point and solubility parameter are outside the predetermined ranges, elongation at break and cold resistance are both reduced (Comparative Examples 1 to 5). This result is considered to be because the plasticizers whose freezing point and solubility parameters are outside the predetermined ranges have low compatibility with the chloroprene rubber in the rubber composition and could not sufficiently prevent crystallization of the chloroprene rubber. (Comparative Examples 1 to 5).

DESCRIPTION OF SYMBOLS 1 Oil fence 11 Float part 111 Core material 112 Cover rubber 12 Skirt part 13 Chain

Claims (10)

For 100 parts by mass of chloroprene rubber,
10 to 30 parts by mass of high styrene rubber,
Containing 5 parts by mass or more and 20 parts by mass or less of a plasticizer,
The plasticizer has a freezing point of −50 ° C. or lower and a solubility parameter of 8.0 or higher and 10.0 or lower.   The rubber composition according to claim 1, wherein the high-styrene rubber is at least one selected from the group consisting of a styrene-butadiene copolymer and a butadiene-styrene-divinylbenzene copolymer.   The rubber composition according to claim 1 or 2, wherein the high styrene rubber has a bound styrene content of 50 mass% or more and 70 mass% or less.   The rubber composition according to any one of claims 1 to 3, wherein the high-styrene rubber has a Mooney viscosity at 100 ° C of 50 or more and 60 or less.   The rubber composition according to any one of claims 1 to 4, wherein the plasticizer is an adipic acid ester. The rubber composition according to any one of claims 1 to 5, wherein the plasticizer is a compound represented by the following general formula (1).

(In Formula (1), R ₁ and R ₂ each independently represents an alkyl group having 5 to 12 carbon atoms.)   The rubber composition according to any one of claims 1 to 6, wherein the chloroprene rubber is non-contaminating chloroprene rubber.   A rubber product obtained by using the rubber composition according to any one of claims 1 to 7.   The rubber product according to claim 8, which is a cover rubber for an oil fence.   The rubber product according to claim 9, comprising a coloring component.

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