JP6100239B2 - Roll molded product using rubber composition - Google Patents

Description

  The present invention relates to a rubber composition containing ethylene-propylene-diene copolymer rubber as a main component, and a roll molded product using the rubber composition.

  Conventionally, a polarizing film in which a dichroic dye is adsorbed and oriented on a polyvinyl alcohol film has been used. That is, an iodine polarizing film using iodine as a dichroic dye, a dye polarizing film using a dichroic dye as a dichroic dye, and the like are known. These polarizing films are usually used as polarizing plates by attaching a protective film such as triacetyl cellulose to one or both sides of the polarizing film via an adhesive made of an aqueous solution of a polyvinyl alcohol resin.

  As a method for producing a polarizing film, a nip roll and a guide roll are used. A polyvinyl alcohol film is immersed in water to swell, then dyed with a dichroic dye, stretched, and then fixed with iodine to the film. Therefore, a method is known in which a polyvinyl alcohol film is treated with boric acid, washed with water and then dried. At this time, the film is stretched by giving a peripheral speed difference to the nip rolls before and after the treatment bath, the film transport direction is changed by the guide roll, and the film is introduced into and taken out of the treatment liquid (for example, Japanese Patent Laid-Open 10-170721 gazette (refer patent document 1)).

  The wet stretching of the polyvinyl alcohol film as described above has a problem that the film is easily cut. One cause of film cutting is deterioration of the nip roll used. The surface layer made of the rubber composition of the nip roll is likely to deteriorate when affected by iodine, boric acid, potassium iodide, etc. adhering to the film (particularly the roll surface becomes hard).

  Japanese Unexamined Patent Publication No. 2011-110819 (Patent Document 2) discloses a nip roll for manufacturing a polarizing film having excellent durability. Such a nip roll is composed of a rubber layer whose main component is EPDM (ethylene-propylene-diene rubber) having at least a surface containing carbon black and vulcanized with a peroxide.

JP-A-10-170721 JP 2011-110819 A

  The surface layer made of the rubber composition of the nip roll is worn out when it is used for a long time. The present invention is a rubber composition mainly composed of EPDM, which is excellent in chemical resistance to chemicals used in the production process of a polarizing film, and further has excellent wear resistance and can form a roll molded product having a long life, and An object of the present invention is to provide a roll molded product using the roll molded product and a method for producing a polarizing film using the roll molded product.

  The present invention relates to a rubber composition comprising an ethylene-propylene-diene copolymer rubber blended with a vulcanizing agent, carbon black, and an antioxidant, and the Mooney viscosity of the ethylene-propylene-diene copolymer rubber is 80 or more. There is provided a rubber composition in which the arithmetic average particle diameter of carbon black is 25 nm or less and the anti-aging agent is a benzimidazole compound.

  The present invention also relates to a rubber composition obtained by blending an ethylene-propylene-diene copolymer rubber with a vulcanizing agent, carbon black, and an antioxidant, and the ethylene-propylene-diene copolymer rubber has a Mooney viscosity of 80. There is provided a rubber composition in which the average particle size of carbon black is 25 nm or less and the anti-aging agent is a reactive anti-aging agent.

  In the rubber composition of the present invention, the vulcanizing agent is 1 to 10 parts by weight, the carbon black is 30 to 90 parts by weight, and the anti-aging agent is 0.5 parts with respect to 100 parts by weight of the ethylene-propylene-diene copolymer rubber. A composition containing ˜3.0 parts by weight is preferred.

  Moreover, this invention is a roll molded article used in the manufacturing process of a polarizing film which has the rubber layer formed from the said rubber composition on the surface.

  Further, the present invention is a production method for producing a polarizing film by subjecting a polyvinyl alcohol film to swelling treatment, dyeing treatment, boric acid treatment and washing treatment in this order, and producing a polarizing film, wherein at least one of these treatments In parallel with the process or separately from these processes, a uniaxial stretching process is performed using the difference in peripheral speed between the two nip rolls, and at least one of the roll molded products constituting the nip roll is the roll molding of the present invention. It is a product.

  The rubber composition of the present invention is excellent in chemical resistance to chemicals used in the manufacturing process of a polarizing film, and further excellent in wear resistance, and is useful for the surface layer of a roll molded product used for manufacturing a polarizing film. It is.

It is explanatory drawing which shows one Embodiment of the uniaxial stretching process method in case a uniaxial stretching process is performed in parallel with a swelling process, a dyeing | staining process, or a boric acid process.

[Rubber composition]
The present invention is a rubber composition obtained by blending an ethylene-propylene-diene copolymer rubber with a vulcanizing agent, carbon black, and an antioxidant. As is well known, ethylene-propylene-diene copolymer rubber (EPDM) is obtained by adding a small amount of a third component (diene component) to ethylene-propylene rubber (EPM), which is a copolymer of ethylene and propylene. Introduced and provided with a double bond in the main chain. Examples of the third component include ethylidene norbornene (ENB), 1,4-hexadiene (1,4-HD), dicyclopentadiene (DCP), and the like. EPDM having a Mooney viscosity of 80 or more is used. When the Mooney viscosity of EPDM is 80 or more, the wear resistance is improved. The iodine value of EPDM is preferably 5-24.

  The rubber composition in the present invention may contain EPDM as a main component and other rubber components. Examples of such other rubber components include, but are not limited to, EPM, butyl rubber, styrene-butadiene rubber, chloroprene rubber, and the like. In this case, the rubber composition according to the present invention preferably contains 70 to 100% by weight of EPDM. When the blending amount of EPDM is less than 70% by weight, the wear resistance and chemical resistance are improved. May decrease.

  The rubber composition of the present invention contains a vulcanizing agent for vulcanizing (crosslinking) EPDM. Examples of the vulcanizing agent include benzoyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 1,1′-di-t-butylperoxy-3,3, Peroxides such as 5-trimethylenecyclohexane and 1,3-di- (t-butylperoxy) -diisopropylbenzene are preferred. The addition amount of the vulcanizing agent is preferably 1 to 10 parts by weight and more preferably 5 to 10 parts by weight with respect to 100 parts by weight of EPDM.

  The rubber composition of the present invention contains carbon black having an arithmetic average particle size of 25 nm or less as a reinforcing agent. When the arithmetic average particle diameter of carbon black exceeds 25 nm, the wear resistance decreases. An example of carbon black used in the present invention is Seest 3 manufactured by Tokai Carbon Co., Ltd. The amount of carbon black added is preferably 30 to 90 parts by weight and more preferably 40 to 70 parts by weight with respect to 100 parts by weight of EPDM. When the added amount of carbon black is less than 30 parts by weight, the wear resistance is not improved and the moldability is also inferior, and when the added amount of carbon black exceeds 90 parts by weight, it becomes difficult to mold, which is not preferable.

  The rubber composition of the present invention contains an anti-aging agent. In the present invention, a benzimidazole compound and / or a reactive antiaging agent is used as an antiaging agent. Examples of the benzimidazole compound include 2-mercaptomethylbenzimidazole and 2-mercaptobenzimidazole. Examples of the reactive anti-aging agent include N-phenyl-N ′-(3-methacryloyloxy-2-hydroxypropyl) -p-phenylenediamine and N- (4-anilinophenyl) methacrylamide. The addition amount of the antioxidant is preferably 0.5 to 3.0 parts by weight, and more preferably 0.8 to 2.0 parts by weight with respect to 100 parts by weight of EPDM.

  In the rubber composition of the present invention, various additives can be blended in addition to the vulcanizing agent, carbon black, and antiaging agent described above. Examples of such additives include reinforcing agents other than carbon black, fillers, paraffinic, naphthenic and aromatic process oils, and vulcanization accelerators such as stearic acid and zinc white. However, it is not limited to these. Examples of the reinforcing agent and filler include acid-resistant additives such as silica and clay.

  The rubber composition of the present invention can be used for production of various molded products such as roll molded products. Since the rubber composition of the present invention is excellent in chemical resistance and abrasion resistance to chemicals used in the production of a polarizing film, a roll molded product in which a surface layer is formed using the rubber composition of the present invention is a polarizing film. It is suitable as a roll used for production.

[Roll molding product]
An example of the manufacturing method of the roll molded product of this invention is demonstrated. After mixing and sufficiently kneading the rubber composition of the present invention described above, a rubber layer is coated on the outer peripheral surface of the core metal of the roll by a predetermined extrusion molding, and then vulcanized under pressure and polished. A roll molded product is obtained. The vulcanization temperature is equal to or higher than the decomposition temperature of the vulcanizing agent used. An adhesive layer may be interposed between the core metal and the rubber layer. The hardness of the adhesive layer is not particularly limited, but is preferably equal to or higher than the rubber hardness of the surface rubber layer in terms of pressure resistance when using a roll and prevention of peeling of the adhesive layer due to chemicals. Examples of the adhesive layer include, but are not particularly limited to, rubber types such as epoxidized rubber that have excellent adhesion to the core metal.

  The obtained roll molded product is suitable for nip rolls used in the manufacturing process of a polarizing film. As a roll molded product for a nip roll used in the manufacturing process of the polarizing film, the rubber layer surface hardness (JIS Type A) is preferably 60 to 85 as a rubber hardness meter. When the rubber hardness of the surface is less than 60, the life and wear resistance of the roll are deteriorated. On the other hand, when the rubber hardness of the surface exceeds 85, the cushioning property is deteriorated, which may adversely affect the film to be processed. The rubber hardness (JIS Type A) of the surface is more preferably 65-80.

[Production method of polarizing film]
The method for producing a polarizing film of the present invention is a method for producing a polarizing film by subjecting a polyvinyl alcohol film to swelling treatment, dyeing treatment, boric acid treatment and washing treatment in this order. Furthermore, a uniaxial stretching process is performed in parallel with at least one of the processes described above or separately from these processes. When performing uniaxial stretching separately from the above-mentioned process, the process of the wet extending process for performing uniaxial stretching is added between the above-mentioned processes. The uniaxial stretching process may be performed in one step, but may be performed in a plurality of steps. Moreover, you may uniaxially stretch a polyvinyl alcohol-type film in gas, such as air or an inert gas, before a swelling process. The final cumulative draw ratio is 4.5 to 7.0 times, preferably 5.0 to 6.5 times.

  In the production method of the present invention, at least one step of the uniaxial stretching treatment is a step of performing uniaxial stretching by utilizing a peripheral speed difference between the nip roll disposed on the upstream side and the nip roll disposed on the downstream side. And at least 1 of the roll molded product which comprises the nip roll used for an upstream side and a downstream is the rubber layer of the surface formed with the rubber composition of this invention, More preferably, it comprises a nip roll. All of the roll molded products have the rubber layer formed on the surface thereof by the rubber composition of the present invention. The details of the roll molded product having the rubber layer formed on the surface thereof by the rubber composition of the present invention are as described above. The roll molded product in which the rubber layer on the surface is formed by the rubber composition of the present invention is excellent in chemical resistance and abrasion resistance, and is an environment where chemicals for boron treatment or chemicals for dyeing adhere. Even if it is used for a long time below, there is little deterioration and the polarizing film can be clamped satisfactorily.

  Examples of the polyvinyl alcohol-based resin that forms the polyvinyl alcohol-based film in the present invention include those obtained by saponifying a polyvinyl acetate-based resin. The degree of saponification is usually 85 mol% or more, preferably 90 mol% or more, more preferably 99 mol% to 100 mol%. Polyvinyl acetate resins include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith, such as ethylene-vinyl acetate copolymer. Examples include coalescence. Examples of other copolymerizable monomers include unsaturated carboxylic acids, olefins, vinyl ethers, and unsaturated sulfonic acids. The degree of polymerization of the polyvinyl alcohol-based resin is usually about 1000 to 10,000, preferably about 1500 to 5,000.

  These polyvinyl alcohol resins may be modified. For example, polyvinyl formal modified with aldehydes, polyvinyl acetal, polyvinyl butyral, and the like may be used. Usually, as a starting material for manufacturing a polarizing film, an unstretched film of a polyvinyl alcohol film having a thickness of 20 μm to 100 μm, preferably 30 μm to 80 μm is used. Industrially, the width of the film is practically 1500 mm to 6000 mm.

  The unstretched film is processed in the order of swelling treatment, dyeing treatment, boric acid treatment (crosslinking treatment) and washing treatment, and finally dried to obtain a polyvinyl alcohol polarizing film having a thickness of, for example, about 5 to 50 μm. .

  The swelling treatment is performed for the purpose of removing foreign substances on the film surface, removing the plasticizer in the film, imparting easy dyeability in the next step, and plasticizing the film. The treatment conditions are determined within a range in which these objects can be achieved and within a range in which problems such as extreme dissolution and devitrification of the base film do not occur. When the film previously stretched in the gas is swollen, for example, the film is immersed in an aqueous solution at 20 ° C. to 70 ° C., preferably 30 ° C. to 60 ° C. The immersion time of the film is preferably about 30 seconds to 300 seconds, more preferably about 60 seconds to 240 seconds. In order to swell the unstretched raw film from the beginning, the film is immersed in an aqueous solution at 10 ° C. to 50 ° C., preferably 20 ° C. to 40 ° C., for example. The immersion time of the film is preferably about 30 seconds to 300 seconds, more preferably about 60 seconds to 240 seconds. Uniaxial stretching may be performed in parallel with the swelling treatment, and the stretching ratio in that case is usually 1.2 to 3.0 times, preferably 1.3 to 2.5 times.

  In the swelling treatment, problems such as swelling of the film in the width direction and wrinkling of the film are likely to occur, so known widening devices such as widening rolls (expander rolls), spiral rolls, crown rolls, cross guiders, bend bars, tenter clips It is preferable to transport the film while removing the wrinkles of the film. For the purpose of stabilizing the film transport in the treatment bath, the water flow in the swelling bath is controlled by an underwater shower, or an EPC device (Edge Position Control device: a device that detects the edge of the film and prevents the film from meandering) ) Etc. are also useful. In this process, since the film swells and expands in the film running direction, if the film is not actively stretched, for example, the speed of the transport roll before and after the processing tank is set to eliminate sagging of the film in the transport direction. It is preferable to take measures such as control. In addition to pure water, boric acid, chlorides, inorganic acids, inorganic salts, water-soluble organic solvents, alcohols, and the like were added to the swelling treatment bath used in the range of 0.01 wt% to 10 wt%. It is also possible to use an aqueous solution.

  The dyeing step with the dichroic dye is performed for the purpose of adsorbing and orienting the dichroic dye on the film. The treatment conditions are determined within a range in which these objects can be achieved and within a range in which problems such as extreme dissolution and devitrification of the base film do not occur. When iodine is used as the dichroic dye, for example, iodine / KI / water = 0.003 to 0.2 / 0.1 at a temperature of 10 ° C. to 45 ° C., preferably 20 ° C. to 35 ° C. and in a weight ratio. The immersion treatment is performed at a concentration of 10/100 for 30 seconds to 600 seconds, preferably 60 seconds to 300 seconds. Instead of potassium iodide, other iodides such as zinc iodide may be used. Other iodides may be used in combination with potassium iodide. In addition, compounds other than iodide, such as boric acid, zinc chloride, and cobalt chloride, may coexist. When boric acid is added, it is distinguished from the following boric acid treatment in that it contains iodine. Any dye containing 0.003 parts by weight or more of iodine with respect to 100 parts by weight of water can be regarded as a dyeing tank.

  When a water-soluble dichroic dye is used as the dichroic dye, for example, the temperature is 20 ° C. to 80 ° C., preferably 30 ° C. to 70 ° C., and the dichroic dye / water = 0.001 to. An immersion treatment is performed at a concentration of 1/100 for 30 seconds to 600 seconds, preferably 60 seconds to 300 seconds. The aqueous solution of the dichroic dye to be used may have a dyeing assistant or the like, and may contain, for example, an inorganic salt such as sodium sulfate, a surfactant or the like. The dichroic dye may be used alone, or two or more dichroic dyes may be used at the same time.

  When a polyvinyl alcohol film is treated in the order of swelling treatment, dyeing treatment, and boric acid treatment, the film is usually stretched in a dyeing tank. The cumulative draw ratio up to the dyeing treatment (the draw ratio in the treatment when there is no drawing treatment before the treatment) is usually 1.6 to 4.5 times, preferably 1.8 to 4.0 times. . Moreover, when the draw ratio of integration up to the dyeing process is less than 1.6 times, the frequency of film breakage increases, and the yield tends to deteriorate.

  The boric acid treatment is performed by immersing a polyvinyl alcohol film dyed with a dichroic dye in an aqueous solution containing, for example, 1 to 10 parts by weight of boric acid with respect to 100 parts by weight of water. When the dichroic dye is iodine, it is preferable to contain 1 to 30 parts by weight of iodide. Examples of iodide include potassium iodide and zinc iodide. Further, compounds other than iodide, such as zinc chloride, cobalt chloride, zirconium chloride, sodium thiosulfate, potassium sulfite, sodium sulfate, etc. may coexist.

  This boric acid treatment is carried out for water resistance, hue adjustment (preventing bluishness, etc.) by crosslinking, and the like. In the case of water resistance by cross-linking, a cross-linking agent such as glyoxal or glutaraldehyde can be used in addition to or together with boric acid, if necessary. In addition, the boric acid treatment for water resistance may be referred to by names such as water resistance treatment, crosslinking treatment, and immobilization treatment. In addition, boric acid treatment for hue adjustment may be referred to by a name such as complementary color treatment or re-dyeing treatment.

  This boric acid treatment is performed by appropriately changing the concentrations of boric acid and iodide and the temperature of the treatment bath according to the purpose. The boric acid treatment for water resistance and the boric acid treatment for hue adjustment are not particularly distinguished, but are carried out under the following conditions. When the raw film is swollen, dyed, and boric acid treated, and the boric acid treatment is aimed at water resistance by cross-linking, 3 to 10 parts by weight of boric acid and iodide are added to 100 parts by weight of water. A boric acid treatment bath containing 1 to 20 parts by weight is used, and is usually performed at a temperature of 50 ° C to 70 ° C, preferably 53 ° C to 65 ° C. The immersion time is usually about 10 to 600 seconds, preferably 20 to 300 seconds, and more preferably 20 to 200 seconds. In addition, when dye | staining and boric-acid-treat the film extended | stretched previously, the temperature of a boric-acid treatment bath is 50 to 85 degreeC normally, Preferably it is 55 to 80 degreeC.

  After boric acid treatment for water resistance, boric acid treatment for hue adjustment may be performed. For example, when the dichroic dye is iodine, a boric acid treatment bath containing 1 to 5 parts by weight of boric acid and 3 to 30 parts by weight of iodide for 100 parts by weight of water is used for this purpose. Usually, it is performed at a temperature of 10 ° C to 45 ° C. The immersion time is usually about 1 to 300 seconds, preferably 2 to 100 seconds.

  These boric acid treatments may be performed a plurality of times and are usually performed 2 to 5 times in many cases. In this case, the aqueous solution composition and temperature of each boric acid treatment tank to be used may be the same or different within the above range. The boric acid treatment for water resistance and the boric acid treatment for hue adjustment may be performed in a plurality of steps, respectively.

  After boric acid treatment, it is washed. The washing treatment is performed, for example, by immersing a polyvinyl alcohol film treated with boric acid for water resistance and / or color tone adjustment in water, spraying water as a shower, or using both immersion and spraying. The temperature of water in the washing treatment is usually about 2 to 40 ° C., and the immersion time is preferably about 2 to 120 seconds. Then, a polarizing film can be obtained by drying a polyvinyl alcohol-type film for about 60 to 600 seconds at the temperature of about 40-100 degreeC in a drying furnace.

  The final integrated draw ratio of the polarizing film in the invention is usually 4.5 to 7 times, preferably 5 to 6.5 times.

  FIG. 1 is an explanatory view showing an embodiment of a uniaxial stretching treatment method in which uniaxial stretching treatment is performed in parallel with swelling treatment, dyeing treatment, or boric acid treatment. In FIG. 1, nip rolls 2 and 2 ′ are provided on the upstream side and the downstream side of the treatment tank 10, respectively, and the peripheral speed of the nip roll 2 ′ on the downstream side is controlled to be higher than the peripheral speed of the nip roll 2 on the upstream side. The polyvinyl alcohol film 1 is uniaxially stretched. The treatment tank 10 is one of a treatment tank for swelling treatment, a treatment tank for dyeing treatment, and a treatment tank for boric acid treatment, and the treatment tank 10 is filled with a treatment solution 4 for immersion. In FIG. 1, it is preferable that all of the roll molded products constituting the nip rolls 2 and 2 'have a rubber layer formed on the surface thereof by the rubber composition of the present invention. Since the rubber composition according to the present invention is excellent in chemical resistance and abrasion resistance, the dye solution and the boric acid treatment solution adhere to the nip rolls 2 and 2 'made of a roll molded product formed using the rubber composition. It can withstand long-term use even if used continuously in an environment.

  The polyvinyl alcohol film 1 is guided into the treatment solution 4 by a plurality of guide rolls 5. In the present invention, the guide roll 5 may also have a rubber layer formed on the surface thereof made of the rubber composition according to the present invention. Since the rubber composition according to the present invention is excellent in chemical resistance and wear resistance, the guide roll 5 formed using the rubber composition may be used by being immersed in the treatment solution 4, for example. It can withstand long-term use.

  Although FIG. 1 shows an embodiment in which both the upstream and downstream nip rolls 2 and 2 ′ are installed in the gas, one or both of these nip rolls 2 and 2 ′ are installed in the processing solution 4. Also good.

  A polarizing plate is obtained by bonding a protective film with an adhesive on at least one side of the polarizing film thus produced. Examples of protective films include films made of acetyl cellulose resins such as triacetyl cellulose and diacetyl cellulose, films made of polyester resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, and films made of polycarbonate resins. And a film made of a cycloolefin resin. Examples of commercially available thermoplastic cycloolefin-based resins include “Topas” (registered trademark) sold by Ticona of Germany and “Arton” (trademark) sold by JSR Co., Ltd. Registered), “ZEONOR” and “ZEONEX” (both registered trademarks) sold by Nippon Zeon Co., Ltd., and “APEL” (trademark registered) sold by Mitsui Chemicals, Inc. A film formed from such a cycloolefin-based resin is used as a protective film. For the film formation, a known method such as a solvent casting method or a melt extrusion method is appropriately used. The formed cycloolefin resin film is also commercially available, for example, “Essina” and “SCA40” sold by Sekisui Chemical Co., Ltd.

  In the present invention, the protective film has a function as a retardation film, a function as a brightness enhancement film, a function as a reflection film, a function as a transflective film, a function as a diffusion film, a function as an optical compensation film, etc. It can also have an optical function. In this case, for example, by laminating an optical functional film such as a retardation film, a brightness enhancement film, a reflection film, a transflective film, a diffusion film, an optical compensation film on the surface of the protective film, it has such a function. In addition, the protective film itself can be provided with such a function. Further, the protective film itself may have a plurality of functions such as a diffusion film having the function of a brightness enhancement film.

  EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated further more concretely, this invention is not limited by these examples.

[Example 1]
EPDM (ethylene-propylene-diene copolymer rubber) "3090EM" (diene species: ethylidene norbornene, Mooney viscosity: 87) manufactured by Mitsui Chemicals, and "Seast 6" (arithmetic average) manufactured by Tokai Carbon Co., Ltd. as carbon black particle size: 22 nm, DBP absorption ^amount: 114 cm 3/100 g), a benzimidazole compound as an anti-aging agent LANXESS Corp. "Vulkanox MB2 '(2-mercaptomethyl-benzimidazole), an organic peroxide as a vulcanizing agent "Perhexa 25B40" (2,5-dimethyl-2,5-di (t-butylperoxy) hexane) manufactured by Nippon Oil & Fats Co., Ltd., and "PW380" (paraffin oil manufactured by Idemitsu Kosan Co., Ltd.) ) As a plasticizer, made by Nippon Seika Co., Ltd. Phosphoric acid as a vulcanization accelerator, an inorganic filler zinc oxide manufactured by Hakusui Tech Co., was used Sanshin Chemical Co., Ltd. of "Sun ester TMP" (trimethylolpropane trimethacrylate) as a crosslinking agent.

The following prescription:
EPDM 100 parts by weight Carbon black 50 parts by weight Anti-aging agent 1 part by weight Vulcanizing agent 7 parts by weight Plasticizer (paraffin oil) 10 parts by weight Vulcanization accelerator (stearic acid) 1 part by weight Inorganic filler (zinc oxide) 5 parts by weight Part Crosslinking aid (trimethylolpropane trimethacrylate) The rubber composition of Example 1 was blended in 3.4 parts by weight.

  The rubber composition to which the above components were added was sufficiently kneaded with a rubber kneader, and then applied to a calender to prepare and prepare an unvulcanized rubber sheet having a thickness of 1.5 mm. The rubber sheet was laminated several times on a metal core which had been previously blasted and coated with an adhesive to cover the rubber. Thus, a rubber roll having a rubber layer with a thickness of 35 mm on the surface was molded. Subsequently, vulcanization was performed at a pressure of 0.5 MPa and a temperature of 160 ° C. for 480 minutes, and after cooling, polishing was performed to obtain a rubber roll of Example 1 having a rubber layer with a thickness of 25 mm on the roll surface.

[Example 2]
The same material as in Example 1 was used except that “APMA” (N- (4-anilinophenyl) methacrylamide) manufactured by Seiko Chemical Co., Ltd., which is a reactive anti-aging agent, was used as the anti-aging agent.

The following prescription:
EPDM 100 parts by weight Carbon black 50 parts by weight Anti-aging agent 2 parts by weight Vulcanizing agent 7 parts by weight Plasticizer (paraffin oil) 10 parts by weight Vulcanization accelerator (stearic acid) 1 part by weight Inorganic filler (zinc oxide) 5 parts by weight Part Crosslinking aid (trimethylolpropane trimethacrylate) The rubber composition of Example 2 was blended in 3.4 parts by weight.

  A rubber roll of Example 2 was obtained in the same manner as Example 1 by using the rubber composition to which the above components were added.

[Comparative Example 1]
"EP65" (diene species: ethylidene norbornene, Mooney viscosity: 74) manufactured by JSR Corporation as EPDM (ethylene-propylene-diene copolymer rubber), and "Seast 3" (arithmetic average particle) manufactured by Tokai Carbon Co., Ltd. as carbon black diameter: 28nm, DBP absorption ^amount: 101cm 3 / 100g), using "TMDQ" Ouchi Shinko chemical Co., Ltd. as an anti-aging agent (2,2,4-trimethyl-1,2-dihydroquinoline polymer) Except for this point, the same material as in Example 1 was used.

The following prescription:
EPDM 100 parts by weight Carbon black 55 parts by weight Anti-aging agent 1 part by weight Vulcanizing agent 7 parts by weight Plasticizer (paraffin oil) 10 parts by weight Vulcanization accelerator (stearic acid) 1 part by weight Inorganic filler (zinc oxide) 5 parts by weight Part Crosslinking aid (trimethylolpropane trimethacrylate) The rubber composition of Comparative Example 1 was blended in 3.4 parts by weight.

  A rubber roll of Comparative Example 1 was obtained in the same manner as in Example 1 using the rubber composition to which the above components were added.

[Comparative Example 2]
Carbon black manufactured by Tokai Carbon Co. Ltd. "Seast 3 '(arithmetic average particle diameter: 28nm, DBP absorption ^amount: 101cm 3 / 100g), manufactured by Ouchi Shinko Chemical Co., Ltd. as an anti-aging agent" TMDQ "(2,2 , 4-trimethyl-1,2-dihydroquinoline polymer), the same material as in Example 1 was used.

The following prescription:
EPDM 100 parts by weight Carbon black 55 parts by weight Anti-aging agent 1 part by weight Vulcanizing agent 7 parts by weight Plasticizer (paraffin oil) 10 parts by weight Vulcanization accelerator (stearic acid) 1 part by weight Inorganic filler (zinc oxide) 5 parts by weight Part Crosslinking aid (trimethylolpropane trimethacrylate) The rubber composition of Comparative Example 2 was blended in 3.4 parts by weight.

  A rubber roll of Comparative Example 2 was obtained in the same manner as in Example 1 using the rubber composition to which the above components were added.

[Comparative Example 3]
The same material as in Example 1 was used except that “EP65” (diene species: ethylidene norbornene, Mooney viscosity: 74) manufactured by JSR Corporation was used as EPDM (ethylene-propylene-diene copolymer rubber).

The following prescription:
EPDM 100 parts by weight Carbon black 50 parts by weight Anti-aging agent 1 part by weight Vulcanizing agent 7 parts by weight Plasticizer (paraffin oil) 10 parts by weight Vulcanization accelerator (stearic acid) 1 part by weight Inorganic filler (zinc oxide) 5 parts by weight Part Crosslinking aid (trimethylolpropane trimethacrylate) The rubber composition of Comparative Example 3 was blended in 3.4 parts by weight.

  A rubber roll of Comparative Example 3 was obtained in the same manner as in Example 1 using the rubber composition to which the above components were added.

[Comparative Example 4]
Tokai Carbon Co., Ltd. of "SEAST 3" as the carbon black (arithmetic average particle diameter: 28nm, DBP absorption ^amount: 101 cm 3/100 g) except using the using the same materials as in Example 1.

The following prescription:
EPDM 100 parts by weight Carbon black 55 parts by weight Anti-aging agent 1 part by weight Vulcanizing agent 7 parts by weight Plasticizer (paraffin oil) 10 parts by weight Vulcanization accelerator (stearic acid) 1 part by weight Inorganic filler (zinc oxide) 5 parts by weight Part Crosslinking aid (trimethylolpropane trimethacrylate) The rubber composition of Comparative Example 4 was blended in 3.4 parts by weight.

  A rubber roll of Comparative Example 4 was obtained in the same manner as in Example 1 using the rubber composition to which the above components were added.

[Comparative Example 5]
As EPDM (ethylene-propylene-diene copolymer rubber), “E” manufactured by JSR Corporation
"P65" (diene species: ethylidene norbornene, Mooney viscosity: 74), "TMDQ" (2,2,4-trimethyl-1,2-dihydroquinoline polymer) manufactured by Ouchi Shinko Chemical Co., Ltd. as an anti-aging agent The same material as in Example 1 was used except for the points described above.

The following prescription:
EPDM 100 parts by weight Carbon black 50 parts by weight Anti-aging agent 1 part by weight Vulcanizing agent 7 parts by weight Plasticizer (paraffin oil) 10 parts by weight Vulcanization accelerator (stearic acid) 1 part by weight Inorganic filler (zinc oxide) 5 parts by weight Part Crosslinking aid (trimethylolpropane trimethacrylate) The rubber composition of Comparative Example 6 was blended in 3.4 parts by weight.

A rubber roll of Comparative Example 5 was obtained in the same manner as in Example 1 using the rubber composition to which the above components were added.

[Comparative Example 6]
As EPDM (ethylene-propylene-diene copolymer rubber), “E” manufactured by JSR Corporation
“P65” (diene species: ethylidene norbornene, Mooney viscosity: 74), “Seast 3” (arithmetic average particle diameter: 28 nm, DBP) manufactured by Tokai Carbon Co., Ltd. as carbon black
^Absorption: 101cm 3 / 100g) except using the using the same materials as in Example 1.

The following prescription:
EPDM 100 parts by weight Carbon black 55 parts by weight Anti-aging agent 1 part by weight Vulcanizing agent 7 parts by weight Plasticizer (paraffin oil) 10 parts by weight Vulcanization accelerator (stearic acid) 1 part by weight Inorganic filler (zinc oxide) 5 parts by weight Part Crosslinking aid (trimethylolpropane trimethacrylate) The rubber composition of Comparative Example 7 was blended in 3.4 parts by weight.

A rubber roll of Comparative Example 6 was obtained in the same manner as in Example 1 using the rubber composition to which each of the above components was added.

<Measurement of Mooney Viscosity of EPDM>
According to JIS K 6300, the Mooney viscosity of EPDM is 1 minute preheating, 100 ° C. measurement time, 4 minutes measurement time using Mooney Viscometer “SMV-300” manufactured by Shimadzu Corporation. It is a measured value.

<Abrasion resistance test>
The rubber compositions of Example 1 and Comparative Examples 1 to 6 were sufficiently kneaded with a rubber kneader, and then applied to a calender machine to produce a 2.2 mm thick unvulcanized rubber sheet. According to K 6299 “Rubber—Method for Preparing Test Sample”, vulcanization was carried out at a vulcanization temperature of 170 ° C. to obtain a rubber sheet having a thickness of 2 mm. The rubber sheet is polished for 6 minutes using a polishing cloth AA-240 in accordance with JIS K 6264 with a pressing load of 3.62 kg, the mass before and after polishing is measured, the polishing mass is divided by the density of the rubber, and wear is performed. The volume was determined.

<Chemical resistance test>
Test pieces of 20 mm × 50 mm and dumbbell shape No. 3 were prepared from the rubber sheets made of the compositions of Examples 1 and 2 and Comparative Examples 2 to 6. Next, the test piece was immersed in a 95 ± 1 ° C. aqueous solution containing 4 parts by weight of boric acid and 12 parts by weight of potassium iodide for 28 days, and the wear volume was measured using a test tube type aging tester manufactured by Toyo Seiki Seisakusho. Asked.

  In addition, as long as there is no trouble in particular, each test piece shall be the same Example 1, 2, and Comparative Examples 1-6 as a rubber roll to respectively correspond. Table 1 shows the compositions and test results of the rubber compositions of Examples 1 and 2 and Comparative Examples 1 to 6.

  From the above, it was found that Examples 1 and 2 were superior to Comparative Examples 1 to 6 in wear resistance.

[Example 3]
(Manufacture of polarizing film)
A 75-μm-thick polyvinyl alcohol film (Kurarevinylone VF-PS # 7500, polymerization degree 2,400, saponification degree 99.9 mol% or more) is kept in pure water at 30 ° C. so that the film does not loosen. The film was immersed for about 130 seconds to fully swell the film. Next, the film was immersed in an aqueous solution of iodine / potassium iodide / water in a weight ratio of 0.02 / 1.5 / 100 and dyed to perform uniaxial stretching.

  Then, the film was immersed in a boric acid crosslinking treatment solution having a composition of 4.0 parts by weight of boric acid, 12 parts by weight of potassium iodide, and 100 parts by weight of water at a temperature of 54 ° C. Uniaxial stretching was performed until the cumulative stretching ratio from the original fabric reached 5.9 times. In that case, the nip roll comprised with the rubber roll obtained in Example 1 was each installed before and after the boric-acid bridge | crosslinking treatment tank, and uniaxial stretching was performed. Subsequently, a washing treatment was performed in pure water at 15 ° C. for 9 seconds. Next, it was dried at a temperature of 60 ° C. for 2 minutes to obtain a polarizing film.

  Although the polarizing film was manufactured continuously for 12 weeks using the manufacturing process of Example 3, troubles such as film breakage did not occur. On the other hand, when the nip roll of Comparative Example 1 was used, film breakage often occurred during the same period of operation.

  The rubber composition of the present invention is useful for forming a rubber roll used for producing a polarizing film.

  1 polyvinyl alcohol film, 2,2 'nip roll, 4 treatment solution, 10 treatment tank.

Claims (4)

A roll molded product used in the manufacturing process of a polarizing film having a rubber layer formed on a surface formed from a rubber composition in which a vulcanizing agent, carbon black, and an antioxidant are blended with an ethylene-propylene-diene copolymer rubber. There,
The ethylene-propylene-diene copolymer rubber has a Mooney viscosity of 80 or more,
The arithmetic average particle diameter of the carbon black is 25 nm or less,
A roll molded product , wherein the anti-aging agent is a benzimidazole compound. A roll molded product used in the manufacturing process of a polarizing film having a rubber layer formed on a surface formed from a rubber composition in which a vulcanizing agent, carbon black, and an antioxidant are blended with an ethylene-propylene-diene copolymer rubber. There,
The ethylene-propylene-diene copolymer rubber has a Mooney viscosity of 80 or more,
The carbon black has an average particle size of 25 nm or less,
A roll molded product , wherein the anti-aging agent is a reactive anti-aging agent. In the rubber composition , 1 to 10 parts by weight of the vulcanizing agent, 30 to 90 parts by weight of the carbon black, and 0 to 0.06 part of the anti-aging agent with respect to 100 parts by weight of the ethylene-propylene-diene copolymer rubber. The roll molded product according to claim 1, comprising 5 to 3.0 parts by weight. A polyvinyl alcohol film is subjected to swelling treatment, dyeing treatment, boric acid treatment and washing treatment in this order to produce a polarizing film,
In parallel with at least one of these processes, or separately from these processes, a uniaxial stretching process is performed using the difference in peripheral speed between the two nip rolls,
The method for producing a polarizing film, wherein at least one of the roll molded products constituting the nip roll is the roll molded product according to any one of claims 1 to 3 .

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