TW201348320A - Rubber composition molded roller using the same - Google Patents

Abstract

This invention provides a rubber composition which is obtained by blending a vulcanizing agent, carbon black, and an anti-aging agent in an ethylene propylene-diene copolymerization rubber, wherein a Mooney viscosity of the ethylene-propylene-diene copolymerization rubber is 80 or more, an arithmetic average particle diameter of the carbon black is 25nm or less, and the anti-aging agent is a benzimidazole-based compound.

Description

Rubber composition and roll molded article using the same

The present invention relates to a rubber composition containing an ethylene-propylene-diene copolymerized rubber as a main component and a roll molded article using the rubber composition.

As a polarizing film, conventionally, a dichroic dye is used to adsorb and align a polyvinyl alcohol-based film. In other words, an iodine-based polarizing film in which iodine is used as a dichroic dye or a dye-based polarizing film in which a dichroic dye is used as a dichroic dye is known. The polarizing film is usually formed by bonding a protective film such as cellulose triacetate to an adhesive layer made of an aqueous solution of a polyvinyl alcohol resin on one or both sides thereof to form a polarizing plate.

As a method for producing a polarizing film, it is known that a polyvinyl alcohol-based film is immersed in water using a nip roll or a guide roll, and then dyed with a dichroic dye and stretched, and then a polyvinyl alcohol-based film is subjected to boric acid. A method of fixing iodine to a film, followed by washing with water and drying. At this time, a peripheral speed difference is applied to the nip rolls before and after the treatment bath to extend the film, and the conveyance direction of the film is changed by the guide rolls, and the film is introduced into and taken out of the treatment liquid (for example, refer to Japanese Patent Application Laid-Open No. Hei 10- Bulletin No. 170721 (patent Literature 1)).

In the wet stretching of the above polyvinyl alcohol-based film, there is a problem that the film is easily cut. One of the causes of the film cutting is the deterioration of the nip rolls used. When the surface layer composed of the rubber composition of the nip rolls is affected by adhesion of iodine, boric acid, potassium iodide or the like to the film, deterioration is likely to occur (especially, the surface of the roll becomes hard).

Japanese Laid-Open Patent Publication No. 2011-110819 (Patent Document 2) discloses a nip roller for producing a polarizing film which is excellent in durability. Such a nip roll is composed of a rubber layer containing at least carbon black on the surface and EPDM (ethylene-propylene-diene rubber) which has been vulcanized with an oxide as a main component.

(previous technical literature)

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 10-170721

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2011-110819

The surface layer of the nip roll composed of the rubber composition causes wear when it continues to be used for a long period of time. An object of the present invention is to provide a rubber composition, a roll molded article using the rubber composition, and a method for producing a polarizing film using the roll molded article, wherein the rubber composition is formed by using EPDM as a main component. A roll molded article having excellent drug resistance liquid properties and excellent wear resistance and long life of the drug used in the production process of the polarizing film.

The present invention provides a rubber composition which is a rubber composition obtained by blending a vulcanizing agent, a carbon black, and an anti-aging agent in an ethylene-propylene-diene copolymer rubber, wherein the ethylene-propylene-diene copolymerized rubber is Mooney The viscosity is 80 or more, the arithmetic mean particle diameter of carbon black is 25 nm or less, and the anti-aging agent is a benzimidazole-based compound.

Moreover, the present invention provides a rubber composition which is a rubber composition obtained by blending a vulcanizing agent, a carbon black, and an anti-aging agent in an ethylene-propylene-diene copolymerized rubber, wherein the ethylene-propylene-diene copolymerized rubber The Mooney viscosity is 80 or more, the carbon black has an average particle diameter of 25 nm or less, and the anti-aging agent is a reactive anti-aging agent.

The rubber composition of the present invention described above contains 1 to 10 parts by weight of a vulcanizing agent, 30 to 90 parts by weight of carbon black, and 0.5 to 3.0 parts by weight based on 100 parts by weight of the ethylene-propylene-diene copolymer rubber. The composition of the anti-aging agent is preferred.

Moreover, the present invention is a roll molded article used in the production step of a polarizing film, which has a rubber layer formed of the above rubber composition on the surface.

Further, the present invention is a method for producing a polarizing film by sequentially performing a swelling treatment, a dyeing treatment, a boric acid treatment, and a washing treatment on a polyvinyl alcohol-based film, and performing the treatment in parallel with any of the processes. In addition to the above-described processes, the uniaxial stretching process using the circumferential speed difference of the two nip rolls is performed, and at least one of the roll molded articles constituting the nip rolls is the above-described roll molded article of the present invention.

The rubber composition of the present invention is excellent in resistance to liquid chemicals used in a production process of a polarizing film, and is excellent in abrasion resistance, and is useful for producing a surface layer of a roll molded article used for a polarizing film. .

1‧‧‧Phenol alcohol film

2‧‧‧ nip rollers

2'‧‧‧ nip rollers

4‧‧‧Processing solution

5‧‧‧guide roller

10‧‧‧Processing tank

Fig. 1 is an explanatory view showing an embodiment of the uniaxial stretching process in the case where the uniaxial stretching treatment is performed in parallel with the swelling treatment, the dyeing treatment, or the boric acid treatment.

[Rubber composition]

The present invention relates to a rubber composition obtained by blending a vulcanizing agent, carbon black, and an anti-aging agent in an ethylene-propylene-diene copolymer rubber. Ethylene-propylene-diene copolymerized rubber (EPDM) is known as a copolymer of ethylene and propylene in ethylene-propylene rubber (EPM), and a small amount of a third component (diene component) is introduced to cause a main chain. There are double keys in the middle. Examples of the third component include ethylene norbornene (ENB), 1,4-hexadiene (1,4-HD), and dicyclopentadiene (DCP). The EPDM system uses a Mooney viscosity of 80 or more. The Mooney viscosity of EPDM is 80 or more, which improves wear resistance. The iodine value of EPDM is preferably from 5 to 24.

The rubber composition of the present invention contains EPDM as a main component and may contain other rubber components. As such other rubber components, examples Examples thereof include EPM, butyl rubber, styrene-butadiene rubber, and chloroprene rubber, but are not limited thereto. In this case, the rubber composition of the present invention preferably contains EPDM in a ratio of 70 to 100% by weight, and when the amount of the EPDM is less than 70% by weight, there is a concern that abrasion resistance or resistance to liquidity is lowered.

The rubber composition of the present invention contains a vulcanizing agent which vulcanizes (crosslinks) EPDM. As the vulcanizing agent, for example, benzamidine peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 1,1'-di A peroxide such as t-butylperoxy-3,3,5-trimethylenecyclohexane or 1,3-bis-(t-butylperoxy)-diisopropylbenzene is preferred. The amount of the vulcanizing agent to be added is preferably from 1 to 10 parts by weight, more preferably from 5 to 10 parts by weight, per 100 parts by weight of the EPDM.

The rubber composition of the present invention contains carbon black having an arithmetic mean particle diameter of 25 nm or less as a reinforcing agent. When the arithmetic mean particle diameter of carbon black is more than 25 nm, the abrasion resistance is low. As the carbon black used in the present invention, SEAST 3 manufactured by Tokai CARBON Co., Ltd. can be exemplified. The amount of carbon black added is preferably from 30 to 90 parts by weight, more preferably from 40 to 70 parts by weight, per 100 parts by weight of the EPDM. When the amount of carbon black added is less than 30 parts by weight, the abrasion resistance is not improved and the formability is also poor. When the amount of carbon black added is more than 90 parts by weight, it is difficult to form.

The rubber composition of the present invention contains an anti-aging agent. In the present invention, as the anti-aging agent, a benzimidazole-based compound and/or a reactive anti-aging agent is used. Examples of the benzimidazole-based compound include 2-hydrothiomethylbenzimidazole and 2-hydrothiobenzimidazole. Further, the reactive anti-aging agent can be exemplified by N-phenyl-N'-(3-methylpropoxy-2-hydroxypropyl)-p-phenylenediamine, N- (4-anilinophenyl)methacrylamide. The amount of the anti-aging agent added is preferably 0.5 to 3.0 parts by weight, more preferably 0.8 to 2.0 parts by weight, per 100 parts by weight of the EPDM.

Further, in the rubber composition of the present invention, various additives may be blended in addition to the above-mentioned vulcanizing agent, carbon black, and anti-aging agent. Examples of such an additive include, but are not limited to, a reinforcing agent other than carbon black, a filler, a paraffin-based, a naphthenic-based, an aromatic-based operating oil agent, and a vulcanization accelerator such as stearic acid or zinc white. These are the same. Further, as the reinforcing agent or the filler, an additive having acid resistance such as ceria or clay can be exemplified.

The rubber composition of the present invention can be used, for example, in the production of various molded articles such as roll molded articles. The rubber composition of the present invention is excellent in resistance to liquid and abrasion resistance to a drug used for producing a polarizing film, and a roll molded article in which a surface layer is formed using the rubber composition of the present invention is suitable for use as a polarizing film. Roller.

[Roll molded product]

An example of a method of producing a roll molded article of the present invention will be described. After the rubber composition of the present invention described above is mixed and sufficiently kneaded, the rubber layer is coated on the outer peripheral surface of the core bar of the roll by a predetermined extrusion molding, and then, vulcanized by pressurization. And grinding, a roll molded product can be obtained. The vulcanization temperature is higher than the decomposition temperature of the vulcanizing agent used. It is also possible to have the adhesive layer interposed between the mandrel and the rubber layer. The hardness of the adhesive layer is not particularly limited, but the rubber hardness of the surface rubber layer is equal to or higher than the rubber hardness of the surface rubber layer. The pressure resistance during use and the prevention of peeling of the adhesive layer by the drug are preferred. In the subsequent layer, a rubber species excellent in adhesion to a mandrel such as an epoxidized rubber is used, but it is not particularly limited.

The obtained roll-formed product is suitable as a nip roll used in the manufacturing process of a polarizing film. In the roll molded article for nip rolls used in the production step of the polarizing film, the hardness (JIS Type A) of the surface of the rubber layer is preferably 60 to 85 as measured by a rubber hardness meter. When the rubber hardness of the surface is less than 60, the life and wear resistance of the roller are deteriorated. On the other hand, when the rubber hardness of the surface is more than 85, the cushioning property is deteriorated and there is a concern that the film to be treated is adversely affected. The rubber hardness (JIS Type A) of the surface is preferably 65 to 80.

[Method of Manufacturing Polarized Film]

The method for producing a polarizing film of the present invention is a method for producing a polarizing film by sequentially performing a swelling treatment, a dyeing treatment, a boric acid treatment, and a washing treatment on a polyvinyl alcohol-based film. Further, the uniaxial stretching process is performed in parallel with at least one of the above processes or in addition to the processes. When uniaxial stretching is additionally performed in addition to the above treatment, a wet stretching treatment step for performing uniaxial stretching may be added between the above treatments. The uniaxial stretching process can be performed in one step or in a plurality of steps. Further, the polyvinyl alcohol-based film may be subjected to uniaxial stretching treatment in a gas such as air or an inert gas before the swelling treatment. The final cumulative stretching ratio is 4.5 to 7.0 times, preferably 5.0 to 6.5 times.

In the manufacturing method of the present invention, the uniaxial stretching process is up to One step is to perform the uniaxial stretching step by using the circumferential speed difference between the nip roller disposed on the upstream side and the nip roller disposed on the downstream side. Further, at least one of the roll molded articles constituting the nip rolls used on the upstream side and the downstream side is a rubber layer on the surface of which the rubber composition of the present invention is used, and preferably all of the roll molded articles constituting the nip rolls are formed. The rubber composition of the present invention is used to form a rubber layer on the surface thereof. The details of the roll molded article obtained by forming the rubber layer on the surface of the rubber composition of the present invention are as described above. A roll-formed product obtained by forming a rubber layer on the surface of the rubber composition of the present invention is excellent in resistance to liquidity and abrasion resistance, even in an environment in which a drug for boron treatment or a drug for dyeing adheres. It is also possible to continue to use for a long period of time and to have less deterioration, and it is possible to satisfactorily hold the polarizing film.

The polyvinyl alcohol-based resin which is formed in the polyvinyl alcohol-based film of the present invention is usually saponified by a polyvinyl acetate-based resin. The degree of saponification is usually 85 mol% or more, preferably 90 mol% or more, and preferably 99 mol% to 100 mol%. As the polyvinyl acetate-based resin, in addition to polyvinyl acetate, which is a homopolymer of vinyl acetate, a copolymer of vinyl acetate and another monomer copolymerizable therewith, such as ethylene-vinyl acetate, may also be mentioned. Ester copolymers and the like. Examples of the other monomer capable of copolymerization include unsaturated carboxylic acids, olefins, vinyl ethers, and unsaturated sulfonic acids. The degree of polymerization of the polyvinyl alcohol-based resin is usually from 1,000 to 10,000, preferably from about 1,500 to 5,000.

These polyvinyl alcohol-based resins may be modified, and for example, polyvinyl formal, polyvinyl acetal, polyvinyl butyral or the like modified with an aldehyde may be used. Usually used as the starting point for the manufacture of polarizing films As the material, an unstretched film of a polyvinyl alcohol-based film having a thickness of from 20 μm to 100 μm, preferably from 30 μm to 80 μm, is used. Industrially, the width of the film is practical from 1500 mm to 6000 mm.

The unstretched film is treated in the order of swelling treatment, dyeing treatment, boric acid treatment (crosslinking treatment), and washing treatment, and finally, the thickness of the polyvinyl alcohol-based polarizing film obtained by drying is, for example, about 5 to 50 μm. .

The swelling treatment is carried out for the purpose of removing foreign matter on the surface of the film, removing the plasticizer in the film, imparting dyeability in the next step, and plasticizing the film. The processing conditions are selected in a range in which the above-described objects can be achieved, and the substrate film does not cause extreme dissolution or loss of transparency. When the film which has been previously extended in the gas is swollen, for example, the film is immersed in an aqueous solution of 20 ° C to 70 ° C, preferably 30 ° C to 60 ° C. The immersion time of the film is preferably from 30 seconds to 300 seconds, more preferably from about 60 seconds to 240 seconds. When the raw film which has not been stretched at the beginning is swollen, for example, the film is immersed in an aqueous solution of 10 ° C to 50 ° C, preferably 20 ° C to 40 ° C. The immersion time of the film is preferably from 30 seconds to 300 seconds, more preferably from about 60 seconds to 240 seconds. It is also possible to perform uniaxial stretching in parallel with the swelling treatment, and as the stretching ratio at this time, it is usually 1.2 to 3.0 times, preferably 1.3 to 2.5 times.

In the swelling treatment, since the film is swollen in the width direction and there is a problem that wrinkles are likely to occur in the film, an expanding roller, a spiral roll, a crown roll, a guide, a bending roll are used. a well-known expansion device such as a tenter clip removes the wrinkles of the film and It is better to carry the film. In order to stabilize the film transport in the treatment bath, the water flow in the swelling bath is controlled by spraying in water, or an EPC device (Edge Position Control device: detecting the end of the film to prevent the film from snaking) is used in combination. It is also useful. In this process, since the film is swollen and expanded in the moving direction of the film, when the film is not actively extended, for example, the speed of the conveyance roller before and after the treatment tank is controlled, and the film sagging for eliminating the conveyance direction is preferable. . Further, the swelling treatment bath to be used may be a boric acid, a chloride, an inorganic acid, an inorganic salt, a water-soluble organic solvent or an alcohol, in an amount of 0.01% by weight to 10% by weight, in addition to pure water. Aqueous solution.

The dyeing step of the dichroic dye is used, and the purpose is to cause the dichroic dye to be adsorbed and aligned in a film or the like. The processing conditions are selected within a range that can achieve such a purpose and does not cause extreme dissolution or loss of transparency. When iodine is used as the dichroic dye, for example, a temperature of 10 ° C to 45 ° C, preferably 20 ° C to 35 ° C, and a weight ratio of iodine / KI / water = 0.003 to 0.2 / 0.1 to 10/100 The immersion treatment is carried out for 30 seconds to 600 seconds, preferably 60 seconds to 300 seconds. Other iodides, such as zinc iodide, may be used instead of potassium iodide. Further, other iodides may be used in combination with potassium iodide. Further, a compound other than the iodide, for example, boric acid, zinc chloride, cobalt chloride or the like may be allowed to coexist. When boric acid is added, it can be distinguished from the following boric acid treatment in terms of containing iodine. It can be regarded as a dyeing tank as long as it contains 0.003 part by weight or more of iodine with respect to 100 parts by weight of water.

When a water-soluble dichroic dye is used as the dichroic dye, For example, the temperature is from 20 ° C to 80 ° C, preferably from 30 ° C to 70 ° C, and the immersion treatment is carried out at a concentration of dichroic dye / water = 0.001 to 0.1 / 100 by weight for 30 seconds to 600 seconds, preferably 60 seconds to 300 seconds. The aqueous solution of the dichroic dye to be used may further contain a dyeing assistant or the like, and may contain, for example, an inorganic salt such as sodium sulfate or a surfactant. The dichroic dye can be used alone or in combination of two or more kinds of dichroic dyes.

When the polyvinyl alcohol-based film is treated in the order of swelling treatment, dyeing treatment, or boric acid treatment, the film is usually stretched using a dyeing tank. The cumulative stretching ratio until the dyeing treatment (the stretching ratio in the treatment until the treatment is not performed) is usually 1.6 to 4.5 times, preferably 1.8 to 4.0 times. Moreover, when the cumulative stretching ratio until the dyeing treatment is less than 1.6 times, the frequency of film breakage tends to increase and the yield tends to be deteriorated.

The boric acid treatment is carried out by impregnating a polyvinyl alcohol-based film dyed with a dichroic dye in an aqueous solution containing, for example, 1 to 10 parts by weight of boric acid per 100 parts by weight of water. When the dichroic dye is iodine, it is preferred to contain 1 to 30 parts by weight of iodide. Examples of the iodide include potassium iodide, zinc iodide, and the like. Further, a compound other than the iodide such as zinc chloride, cobalt chloride, zirconium chloride, sodium thiosulfate, potassium sulfite, sodium sulfate or the like may be allowed to coexist.

This boric acid treatment is carried out in order to achieve water resistance, adjust hue (to prevent bluing, etc.), etc. by crosslinking. In order to achieve water resistance by crosslinking, a crosslinking agent such as glyoxal or glutaraldehyde may be used in addition to or in addition to boric acid. Also, there are also boric acid treatments that are resistant to hydration. It is called the name of water resistance treatment, cross-linking treatment, and immobilization treatment. Further, there is a case where the boric acid treatment for adjusting the hue is used, and the name is called a complementary color treatment or a re-dye treatment.

This boric acid treatment can be carried out by appropriately changing the concentration of boric acid and iodide and the temperature of the treatment bath in accordance with the purpose. The boric acid treatment for hydration resistance and the boric acid treatment for adjusting the hue are not particularly distinguished, and can be carried out under the following conditions. When the raw material film is subjected to swelling, dyeing, or boric acid treatment, the boric acid treatment is carried out by crosslinking to make the water resistant, and 3 to 10 parts by weight of boric acid and 1 to 20 parts by weight are used with respect to 100 parts by weight of water. The boric acid treatment bath of iodide is usually carried out at a temperature of from 50 ° C to 70 ° C, preferably from 53 ° C to 65 ° C. The immersion time is usually from about 10 to 600 seconds, preferably from 20 to 300 seconds, preferably from 20 to 200 seconds. Further, in the case of dyeing or boric acid treatment of the previously stretched film, the temperature of the boric acid treatment bath is usually from 50 ° C to 85 ° C, preferably from 55 ° C to 80 ° C.

After treatment with boric acid which is resistant to hydration, boric acid treatment for adjusting the hue can also be carried out. For example, when the dichroic dye is iodine, for this purpose, a boric acid treatment bath containing 1 to 5 parts by weight of boric acid and 3 to 30 parts by weight of iodide relative to 100 parts by weight of water is used, usually at 10 ° C to 45 ° C. The temperature is carried out. The immersion time is usually from about 1 to 300 seconds, preferably from 2 to 100 seconds.

These boric acid treatments can also be carried out a plurality of times, usually for 2 to 5 times. In this case, the aqueous solution composition and temperature of each of the boric acid treatment tanks used may be the same or different. The above-mentioned boric acid treatment for hydration resistance and boric acid treatment for adjusting the hue can also be used. Each of them performs a plurality of steps.

After the boric acid treatment, it is washed. The washing treatment is carried out, for example, by immersing a polyvinyl alcohol-based film treated with boric acid which is resistant to hydration and/or adjusting the color tone in water, spraying by spraying water, or immersing and spraying together. The temperature of the water to be washed is usually about 2 to 40 ° C, and the immersion time may be about 2 to 120 seconds. Subsequently, a polarizing film can be obtained by drying the polyvinyl alcohol-based film in a drying oven at a temperature of about 40 to 100 ° C for about 60 to 600 seconds.

The cumulative cumulative stretching ratio at the end of the stretching of the polarizing film of the present 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 the first drawing, the nip rolls 2, 2' are provided on the upstream side and the downstream side of the processing tank 10, respectively, and the peripheral speed of the nip roller 2' on the downstream side is compared with the peripheral speed of the nip roller 2 on the upstream side. The control is relatively fast, and the polyvinyl alcohol-based film 1 is uniaxially stretched. The treatment tank 10 is any one of a treatment tank for swelling treatment, a treatment tank for dyeing treatment, and a treatment tank for boric acid treatment, and the inside of the treatment tank 10 is filled with the treatment solution 4 for impregnation. In the first embodiment, it is preferable that all of the roll molded articles constituting the nip rolls 2, 2' are rubber layers which form the surface thereof using the rubber composition of the present invention. Since the rubber composition of the present invention is excellent in resistance to liquidity and abrasion resistance, the nip rolls 2, 2' composed of the roll molded articles formed using the same, even in the environment in which the dyeing solution and the boric acid treatment solution adhere. Continue to use, can also withstand long-term use.

The polyvinyl alcohol-based film 1 is guided by a plurality of guide rolls 5 Up to the treatment solution 4. In the present invention, a rubber layer composed of the rubber composition of the present invention may be formed on the surface of the guide roller 5. Since the rubber composition of the present invention is excellent in liquid resistance and abrasion resistance, the guide roller 5 formed using the same can be used for a long period of time even if it is immersed in, for example, the treatment solution 4.

In Fig. 1, an embodiment in which both the upstream and downstream nip rolls 2, 2' are disposed in a gas is shown, but one or both of the nip rolls 2, 2' may be disposed in the treatment solution 4 Inside.

On at least one surface of the polarizing film produced in this manner, a polarizing plate was obtained by bonding a protective film with an adhesive. The protective film may, for example, be a film composed of a cellulose acetate resin such as cellulose triacetate or cellulose diacetate; for example, polyethylene terephthalate, polyethylene naphthalate, polypair A film composed of a polyester resin of butylene phthalate; a film composed of a polycarbonate resin; and a film composed of a cycloolefin resin. As a commercially available thermoplastic cycloolefin resin, for example, "Topas (registered trademark) sold by Ticona Co., Ltd., "ARTON" (registered trademark) sold by JSR (share), and by Japanese ZEON (share) "ZEONOR" and "ZEONEX" (all of which are registered trademarks), "APEL" (registered trademark) sold by Mitsui Chemicals Co., Ltd., etc. A film formed of these cycloolefin-based resins is used as a protective film, and a well-known method such as a solvent casting method or a melt extrusion method can be suitably used for the film formation. The cycloolefin-based resin film which is formed into a film is also commercially available, for example, "S-SINA" or "SCA40" which are sold by Sekisui Chemical Industry Co., Ltd.

In the present invention, it is also possible to have the protective film as a phase The function of the difference film, the function as a brightness enhancement film, the function of a reflective film, the function as a semi-transmissive reflection film, the function as a diffusion film, and the function as an optical compensation film. In this case, in addition to the optical functional film such as a surface layer retardation film, a brightness enhancement film, a reflective film, a transflective film, a diffusion film, or an optical compensation film on the surface of the protective film, it is possible to have such a function. It is also possible to impart such a function to the protective film itself. Further, the protective film itself may have a plurality of functions such as a diffusion film having a function of brightness enhancement film.

[Examples]

Hereinafter, the present invention will be more specifically described by way of examples, but the present invention is not limited by the examples.

[Example 1]

"3090EM" (diene species: ethylene norbornene, Mooney viscosity: 87) manufactured by Mitsui Chemicals Co., Ltd. as EPDM (ethylene-propylene-diene copolymer rubber), "SEAST6" manufactured by Tokai CARBON Co., Ltd. (Arithmetic mean particle diameter: 22 nm, DBP absorption amount: 114 cm ³ /100 g) As a carbon black, a benzimidazole-based compound "Vulkanox MB2" (2-hydrothiomethylbenzimidazole) manufactured by LANXESS Co., Ltd. was used as an anti-aging product. Agent, organic peroxide "PERHEXA 25B40" (2,5-dimethyl-2,5-di(t-butylperoxy)hexane) manufactured by Nippon Oil & Fat Co., Ltd. as a vulcanizing agent, and will be produced "PW380" (paraffin oil) manufactured by the company is used as a plasticizer, and stearic acid manufactured by Nippon Seiki Co., Ltd. is used as a vulcanization accelerator, and zinc oxide manufactured by HAKUSUITECH Co., Ltd. is used as an inorganic filler. "SUNESTER TMP" (trimethylolpropane trimethacrylate) manufactured by Chemicals Co., Ltd. is used as a crosslinking assistant.

The rubber composition of Example 1 was formulated using the following formulation: 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

1 part by weight of vulcanization accelerator (stearic acid)

Inorganic filler (zinc oxide) 5 parts by weight

Crosslinking aid (trimethylolpropane trimethacrylate) 3.4 parts by weight

The rubber composition to which each of the above components was added was sufficiently kneaded by a rubber blender, and then placed on a calender to prepare an unvulcanized rubber sheet having a thickness of 1.5 mm. The mandrel which has been subjected to sand blasting in advance and applied with an adhesive agent is laminated on the rubber sheet several times to coat the rubber. Thereby, a rubber roller having a rubber layer having a thickness of 35 mm on the surface was formed. Subsequently, the rubber was subjected to vulcanization at a pressure of 0.5 MPa and a temperature of 160 ° C for 480 minutes and subjected to cooling and then to obtain a rubber roll of Example 1 having a rubber layer having a thickness of 25 mm on the surface of the roll.

[Embodiment 2]

The same material as in Example 1 was used except that the reactive anti-aging agent "APMA" (N-(4-anilinophenyl)methacrylamide) manufactured by Seiko Chemical Co., Ltd. was used as the anti-aging agent.

The rubber composition of Example 2 was formulated using the following formulation: 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

1 part by weight of vulcanization accelerator (stearic acid)

Inorganic filler (zinc oxide) 5 parts by weight

Crosslinking aid (trimethylolpropane trimethacrylate) 3.4 parts by weight

The rubber roller of Example 2 was obtained in the same manner as in Example 1 except that the rubber composition containing the above components was added.

[Comparative Example 1]

In addition to "EP65" (diene species: ethylene norbornene, Mooney viscosity: 74) manufactured by JSR AG, EPDM (ethylene-propylene-diene copolymer rubber), "SEAST3" manufactured by Tokai CARBON Co., Ltd. "(Arithmetic mean particle size: 28 nm, DBP absorption: 101 cm ³ / 100 g) as carbon black, "TMDQ" (2,2,4-trimethyl-1,2-dihydrogen manufactured by Ouchi Revituction Chemical Co., Ltd.) The same material as in Example 1 was used as the anti-aging agent.

The rubber composition of Comparative Example 1 was formulated using the following formulation: 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

1 part by weight of vulcanization accelerator (stearic acid)

Inorganic filler (zinc oxide) 5 parts by weight

Crosslinking aid (trimethylolpropane trimethacrylate) 3.4 parts by weight

The rubber roller of Comparative Example 1 was obtained in the same manner as in Example 1 except that the rubber composition containing the above components was added.

[Comparative Example 2]

In addition to "SEAST3" (arithmetic average particle size: 28 nm, DBP absorption: 101 cm ³ /100 g) manufactured by Tokai CARBON Co., Ltd. as "carbon black", "TMDQ" manufactured by Ouchi Revital Chemical Co., Ltd. (2, 2, 4- The same material as in Example 1 was used as the anti-aging agent other than the trimethyl-1,2-dihydroquinoline polymer.

The rubber composition of Comparative Example 2 was formulated using the following formulation: 100 parts by weight of EPDM

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

1 part by weight of vulcanization accelerator (stearic acid)

Inorganic filler (zinc oxide) 5 parts by weight

Crosslinking aid (trimethylolpropane trimethacrylate) 3.4 parts by weight

Using a rubber composition to which the above components are added, In the same manner as in Example 1, the rubber roller of Comparative Example 2 was obtained.

[Comparative Example 3]

The same procedure as in Example 1 was carried out except that "EP65" (diene species: ethylene norbornene, Mooney viscosity: 74) manufactured by JSR AG was used as EPDM (ethylene-propylene-diene copolymer rubber). material.

The rubber composition of Comparative Example 3 was formulated using the following formulation: 100 parts by weight of EPDM

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

1 part by weight of vulcanization accelerator (stearic acid)

Inorganic filler (zinc oxide) 5 parts by weight

Crosslinking aid (trimethylolpropane trimethacrylate) 3.4 parts by weight

The rubber roller of Comparative Example 3 was obtained in the same manner as in Example 1 except that the rubber composition containing the above components was added.

[Comparative Example 4]

The same material as in Example 1 was used except that "SEAST3" (arithmetic average particle diameter: 28 nm, DBP absorption: 101 cm ³ / 100 g) manufactured by Tokai Carbon Co., Ltd. was used as the carbon black.

The rubber composition of Comparative Example 4 was formulated using the following formulation: 100 parts by weight of EPDM

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

1 part by weight of vulcanization accelerator (stearic acid)

Inorganic filler (zinc oxide) 5 parts by weight

Crosslinking aid (trimethylolpropane trimethacrylate) 3.4 parts by weight

The rubber roller of Comparative Example 4 was obtained in the same manner as in Example 1 except that the rubber composition containing the above components was added.

[Comparative Example 5]

In addition to the use of "EP65" (diene species: ethylene norbornene, Mooney viscosity: 74) manufactured by JSR AG, EPDM (ethylene-propylene-diene copolymer rubber), manufactured by Ouchi Revitalization Chemical Co., Ltd. "TMDQ" (2,2,4-trimethyl-1,2-dihydroquinoline polymer) was used as the anti-aging agent in the same manner as in Example 1.

The rubber composition of Comparative Example 5 was formulated using the following formulation: 100 parts by weight of EPDM

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

1 part by weight of vulcanization accelerator (stearic acid)

Inorganic filler (zinc oxide) 5 parts by weight

Crosslinking aid (trimethylolpropane trimethacrylate) 3.4 parts by weight

The rubber roller of Comparative Example 5 was obtained in the same manner as in Example 1 except that the rubber composition containing the above components was added.

[Comparative Example 6]

In addition to "EP65" (diene species: ethylene norbornene, Mooney viscosity: 74) manufactured by JSR AG, EPDM (ethylene-propylene-diene copolymer rubber), "SEAST3" manufactured by Tokai CARBON Co., Ltd. (Arithmetic mean particle diameter: 28 nm, DBP absorption amount: 101 cm ³ /100 g) The same material as in Example 1 was used as carbon black.

The rubber composition of Comparative Example 6 was formulated using the following formulation: 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

1 part by weight of vulcanization accelerator (stearic acid)

Inorganic filler (zinc oxide) 5 parts by weight

Crosslinking aid (trimethylolpropane trimethacrylate) 3.4 parts by weight

The rubber roller of Comparative Example 6 was obtained in the same manner as in Example 1 except that the rubber composition containing the above components was added.

<EPIM Mooney Viscosity Measurement>

The Mooney viscosity of EPDM is based on JIS K 6300 and is produced by Shimadzu. The L rotor of the Mooney viscometer "SMV-300" manufactured by the company was measured by preheating for 1 minute, measuring temperature at 100 ° C, and measuring time for 4 minutes.

<Abrasion resistance test>

The rubber composition of the above-mentioned Example 1 and Comparative Examples 1 to 6 was sufficiently kneaded using a rubber blending machine, and then placed on a calender to produce an unvulcanized rubber sheet having a thickness of 2.2 mm, in accordance with JIS K 6299 "Rubber Test Specimen" The production method was carried out by vulcanization at a vulcanization temperature of 170 ° C to obtain a rubber sheet having a thickness of 2 mm. The rubber sheet was subjected to grinding for 6 minutes at a load of 3.62 kg in accordance with JIS K 6264, and the mass before and after the polishing was measured, and the grinding mass was divided by the density of the rubber to obtain the abrasion volume.

<Drug resistance test>

From the rubber sheets composed of the compositions of the above Examples 1 and 2 and Comparative Examples 2 to 6, a test piece of 20 mm × 50 mm and a dumbbell-shaped No. 3 shape was produced. Subsequently, the test piece was immersed in an aqueous solution containing 95 parts by weight of boric acid and 12 parts by weight of potassium iodide at 95 ± 1 ° C for 28 days, and the abrasion volume was determined using a test tube aging tester manufactured by Toyo Seiki Seisakusho Co., Ltd.

Further, as long as there were no particular obstacles, each test piece was set to be the same as Examples 1 and 2 and Comparative Examples 1 to 6 which are the same as the respective rubber rolls. The compositions and test results of the rubber compositions of Examples 1 and 2 and Comparative Examples 1 to 6 are shown in Table 1.

As described above, it was found that Examples 1 and 2 were superior in abrasion resistance as compared with Comparative Examples 1 to 6.

[Example 3] (Manufacture of polarizing film)

A polyvinyl alcohol film (KURARAY VINYLON VF-PS #7500, polymerization degree 2,400, saponification degree: 99.9 mol% or more) having a thickness of 75 μm was kept in a state of tension without being loosened, and immersed in pure water at 30 ° C. The film was fully swelled for 130 seconds. Next, the aqueous solution immersed in iodine/potassium iodide/water at a weight ratio of 0.02/1.5/100 was subjected to uniaxial stretching while performing dyeing treatment.

Subsequently, the film was immersed in a boric acid crosslinking treatment liquid having a composition of 4.0 parts by weight of boric acid, 12 parts by weight of potassium iodide, 100 parts by weight of water, and a temperature of 54 ° C for about 39 seconds, and uniaxially stretched while performing crosslinking treatment. The cumulative stretching ratio from the green film was 5.9 times. At this time, a nip roll composed of the rubber roller obtained in Example 1 was placed in front of and behind the boric acid crosslinking treatment tank to perform uniaxial stretching. Subsequently, the washing treatment was carried out 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.

The polarizing film was continuously produced for 12 weeks using the manufacturing procedure of Example 3, and problems such as film breakage did not occur. On the other hand, when the nip rolls of the comparative example 1 were used, film fracture often occurred in the operation of the same period.

(industrial use possibility)

The rubber composition of the present invention is used in the formation. A rubber roller that produces a polarizing film is useful.

1‧‧‧Phenol alcohol film

2‧‧‧ nip rollers

2'‧‧‧ nip rollers

4‧‧‧Processing solution

5‧‧‧guide roller

10‧‧‧Processing tank

Claims (5)

A rubber composition obtained by blending a vulcanizing agent, a carbon black, and an anti-aging agent in an ethylene-propylene-diene copolymer rubber, wherein the Mooney viscosity of the ethylene-propylene-diene copolymer rubber is In the case of 80 or more, the arithmetic mean particle diameter of the carbon black is 25 nm or less, and the anti-aging agent is a benzimidazole-based compound. A rubber composition obtained by blending a vulcanizing agent, a carbon black, and an anti-aging agent in an ethylene-propylene-diene copolymer rubber, wherein the Mooney viscosity of the ethylene-propylene-diene copolymer rubber is The carbon black has an average particle diameter of 25 nm or less, and the anti-aging agent is a reactive anti-aging agent. The rubber composition according to claim 1 or 2, which contains 1 to 10 parts by weight of the above-mentioned vulcanizing agent and 30 to 90 parts of the aforementioned carbon black with respect to 100 parts by weight of the above ethylene-propylene-diene copolymer rubber. Parts by weight, the aforementioned anti-aging agent, is 0.5 to 3.0 parts by weight. A roll-formed article used in the production step of the polarizing film is a rubber layer formed on the surface of the rubber composition according to any one of claims 1 to 3. A method for producing a polarizing film, which is a method for producing a polarizing film by sequentially performing a swelling treatment, a dyeing treatment, a boric acid treatment, and a washing treatment on a polyvinyl alcohol-based film, wherein, in parallel with any of the processes Performing, or performing, in addition to the processes, at least one of the roll forming products of the nip rolls, which are uniaxially stretched by the circumferential speed difference of the two nip rolls, A roll molded article as described in claim 4 of the patent application.