KR20140134650A - Rubber composition and roll-shaped molding using said rubber composition - Google Patents

Abstract

The rubber composition of the present invention is obtained by blending a vulcanizing agent, carbon black and an antioxidant in an ethylene-propylene-diene copolymer rubber, wherein the ethylene-propylene-diene copolymer rubber has a Mooney viscosity of 80 or more, The diameter is 25 nm or less, and the antioxidant is a benzimidazole-based compound.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a rubber composition,

The present invention relates to a rubber composition comprising an ethylene-propylene-diene copolymer rubber as a main component, and a roll formed article using the rubber composition.

As a polarizing film, conventionally, a polyvinyl alcohol film having a dichroic dye adsorbed and oriented has been used. That is, an iodine-based polarizing film using iodine as a dichroic dye or a dye-based polarizing film using a dichroic dye as a dichroic dye are known. These polarizing films are usually polarized by adhering a protective film such as triacetylcellulose through an adhesive composed of an aqueous solution of a polyvinyl alcohol resin to one surface or both surfaces thereof.

As a method for producing a polarizing film, a polyvinyl alcohol film is dipped in water to swell by using a nip roll or a guide roll, dyed with a dichroic dye, stretched, and then fixed on the film There is known a method 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 imparting a difference in peripheral speed to the nip rolls before and after the treatment bath (processing bath), and the direction of transporting the film is changed by the guide roll to introduce and take out the film to the processing liquid (See, for example, Japanese Patent Application Laid-Open No. 10-170721 (Patent Document 1)).

There has been a problem that the film is likely to be cut in the wet stretching of the polyvinyl alcohol-based film. One of the causes of film cutting is deterioration of the nip roll used. The surface layer made of the rubber composition of the nip roll is liable to deteriorate (particularly, the surface of the roll becomes hard) when it is affected by iodine, boric acid, potassium iodide or the like attached to the film.

Japanese Patent Laying-Open No. 2011-110819 (Patent Document 2) discloses a nip roll for producing a polarizing film excellent in durability. Such a nip roll is composed of a rubber layer composed mainly of EPDM (ethylene-propylene-diene rubber) whose surface contains carbon black and is vulcanized with peroxide.

Patent Document 1: JP-A-10-170721 Patent Document 2: Japanese Patent Laid-Open Publication No. 2011-110819

The surface layer made of the rubber composition of the nip roll is worn out if it continues to be used over a long period of time. The present invention relates to a rubber composition containing EPDM as a main component capable of forming a roll formed product excellent in resistance to chemicals and having excellent resistance to abrasion with respect to chemicals used in the production process of a polarizing film, And a process for producing a polarized film using the roll-formed product.

The present invention relates to a rubber composition comprising an ethylene-propylene-diene copolymer rubber and a vulcanizing agent, carbon black and an antioxidant, wherein the ethylene-propylene-diene copolymer rubber has a Mooney viscosity of 80 or more and an arithmetic mean particle diameter Is 25 nm or less, and the antioxidant is a benzimidazole-based compound.

The present invention also provides a rubber composition comprising an ethylene-propylene-diene copolymer rubber blended with a vulcanizing agent, carbon black and an antioxidant, wherein the ethylene-propylene-diene copolymer rubber has a Mooney viscosity of 80 or more, A rubber composition having a diameter of 25 nm or less and an antioxidant as a reactive antioxidant.

1 to 10 parts by weight of a vulcanizing agent, 30 to 90 parts by weight of carbon black, and 0.5 parts by weight of an antioxidant, based on 100 parts by weight of an ethylene-propylene-diene copolymer rubber, To 3.0 parts by weight is preferable.

Further, the present invention is a roll formed article used in the production process of a polarizing film having a rubber layer formed on the surface thereof.

The present invention also provides a production method for producing a polarizing film by performing a swelling treatment, a dyeing treatment, a boric acid treatment, and a cleaning treatment on a polyvinyl alcohol-based film in this order, wherein in parallel with at least one of these treatments , Or in addition to these treatments, uniaxial stretching is performed using the main speed difference of the two nip rolls, and at least one of the roll formed articles constituting the nip roll is the roll molded article of the present invention.

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

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an explanatory view showing one embodiment of a uniaxial stretching treatment method in which uniaxial stretching treatment is carried out in parallel with swelling treatment, dyeing treatment or boric acid treatment.

[Rubber composition]

The present invention relates to a rubber composition comprising an ethylene-propylene-diene copolymer rubber and a vulcanizing agent, carbon black and an antioxidant. As is well known, an ethylene-propylene-diene copolymer rubber (EPDM) is produced by introducing a small amount of a third component (diene component) into an ethylene-propylene rubber (EPM), which is a copolymer of ethylene and propylene, ) Having a double bond. Examples of the third component include ethylidene norbornene (ENB), 1,4-hexadiene (1,4-HD), dicyclopentadiene (DCP) and the like. The EPDM has a Mooney viscosity of 80 or more. When the Mooney viscosity of the EPDM is 80 or more, the abrasion resistance is improved. The iodine value of EPDM is preferably 5 to 24.

The rubber composition of 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, it is preferable that the rubber composition of the present invention contains EPDM in a proportion of 70 to 100% by weight, and if the amount of EPDM is less than 70% by weight, there is a fear that the abrasion resistance and the medicine liquidity are lowered .

The rubber composition of the present invention includes 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'- 5-trimethylenecyclohexane, and 1,3-di- (t-butylperoxy) -diisopropylbenzene. The addition amount of the vulcanizing agent is preferably 1 part by weight to 10 parts by weight, more preferably 5 parts by weight to 10 parts by weight, based on 100 parts by weight of EPDM.

The rubber composition of the present invention includes carbon black having an arithmetic average particle diameter of 25 nm or less as a reinforcing agent. When the arithmetic average particle diameter of carbon black exceeds 25 nm, abrasion resistance is lowered. Examples of the carbon black used in the present invention include Syst 3 manufactured by Tokai Carbon Kabushiki Kaisha. The addition amount of carbon black is preferably 30 parts by weight to 90 parts by weight, more preferably 40 parts by weight to 70 parts by weight, based on 100 parts by weight of EPDM. When the amount of the carbon black to be added is less than 30 parts by weight, the abrasion resistance is not improved and the moldability is inferior. If the amount of the carbon black is more than 90 parts by weight, molding becomes difficult.

The rubber composition of the present invention includes an antioxidant. In the present invention, a benzimidazole-based compound and / or a reactive antioxidant are used as the antioxidant. Examples of the benzimidazole-based compound include 2-mercaptomethylbenzimidazole and 2-mercaptobenzimidazole. The reactive antioxidant may be at least one selected from the group consisting of N-phenyl-N'- (3-methacryloyloxy-2-hydroxypropyl) -p-phenylenediamine and N- (4-anilinophenyl) do. The amount of the antioxidant added is preferably 0.5 to 3.0 parts by weight, more preferably 0.8 to 2.0 parts by weight, based on 100 parts by weight of the EPDM.

In addition, in the rubber composition of the present invention, various additives may be added in addition to the above vulcanizing agent, carbon black and anti-aging agent. Examples of such additives include, but are not limited to, process oils such as reinforcing agents other than carbon black, fillers, paraffin, naphthene, and aromatics, and vulcanization accelerators such as stearic acid and zincification. On the other hand, examples of the reinforcing agent and filler include additives having acid resistance such as silica and clay.

The rubber composition of the present invention can be used, for example, in the production of various molded articles such as a roll formed article. Since the rubber composition of the present invention is excellent in chemical resistance and abrasion resistance to drugs used in the production of polarizing films, a roll formed article having a surface layer formed using the rubber composition of the present invention is excellent in transparency, .

[Roll shaped article]

An example of a method for producing a roll formed article of the present invention will be described. The rubber composition of the present invention is mixed and sufficiently kneaded, and then the rubber layer is coated on the outer peripheral surface of the core of the roll by a predetermined extrusion molding or the like, followed by vulcanization under pressure and polishing, . The vulcanization temperature is not lower than the decomposition temperature of the vulcanizing agent to be used. An adhesive layer may be interposed between the core layer and the rubber layer. The hardness of the adhesive layer is not particularly limited, but it is preferable that the rubber hardness of the surface rubber layer is not less than the rubber hardness of the surface rubber layer in preventing the pressure resistance at the time of using the roll or peeling of the adhesive layer by chemicals. The adhesive layer may be an epoxy rubber or the like, which is excellent in adhesion to the core, but is not particularly limited.

The resulting roll-shaped article is suitable for use in a nip roll used in a production process of a polarizing film. It is preferable that the hardness (JIS Type A) of the surface of the rubber layer is from 60 to 85 as a rubber hardness meter for the nip roll used in the production process of the polarizing film. If the rubber hardness of the surface is less than 60, the life and abrasion resistance of the roll become poor. On the other hand, when the rubber hardness of the surface exceeds 85, the cushion property is deteriorated, and there is a fear that the film to be treated is adversely affected. The rubber hardness (JIS Type A) of the surface is more preferably 65 to 80.

[Production method of polarizing film]

A production method of a polarizing film of the present invention is a production method for producing a polarizing film by performing a swelling treatment, a dyeing treatment, a boric acid treatment and a cleaning treatment on a polyvinyl alcohol film in this order. In addition, the uniaxial stretching process is performed in parallel with or in addition to at least one of the above processes. When uniaxial stretching is carried out separately from the above-mentioned treatment, a wet stretching treatment step for performing uniaxial stretching is added between the above-mentioned treatments. The uniaxial stretching treatment may be performed in one step, but may be performed in a plurality of steps. In addition, before the swelling treatment, the polyvinyl alcohol film may be subjected to uniaxial stretching treatment in a gas such as air or an inert gas in advance. The final integrated (integrated) 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 using the peripheral speed difference between the upstream side nip roll and the downstream side nip roll. At least one of the roll formed articles constituting the nip roll used for the upstream side and the downstream side is a rubber layer formed on the surface thereof by the rubber composition of the present invention. More preferably, The rubber layer on the surface thereof is formed. The details of the roll formed article having the rubber layer on its surface formed by the rubber composition of the present invention are as described above. The roll formed article having the rubber layer on its surface formed by the rubber composition of the present invention is excellent in the liquid medicine resistance and abrasion resistance and can be used even under long-term use under an environment in which a chemical for treating boron or a chemical for dyeing is adhered, The polarizing film can be held well.

The polyvinyl alcohol-based resin forming the polyvinyl alcohol-based film in the present invention is usually one obtained by saponifying a polyvinyl acetate-based resin. The saponification degree is usually 85 mol% or more, preferably 90 mol% or more, and more preferably 99 mol% to 100 mol%. Examples of the polyvinyl acetate resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, as well as copolymers of vinyl acetate and other monomers copolymerizable therewith, such as ethylene-vinyl acetate copolymer. 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 10000, and preferably about 1500 to 5,000.

These polyvinyl alcohol resins may be modified, and examples thereof include polyvinyl formal modified with aldehydes, polyvinyl acetal, polyvinyl butyral, and the like. Usually, an unoriented film of a polyvinyl alcohol film having a thickness of 20 mu m to 100 mu m, preferably 30 mu m to 80 mu m is used as a starting material for polarizing film production. The width of the film is practically 1500 to 6000 mm industrially.

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

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

In the swelling process, the film tends to swell in the width direction and wrinkles are likely to occur on the film. Therefore, a wider width roll (expander roll), a spiral roll, a crown roll, a cloth guider, a bend bar, It is preferable to transport the film while removing the wrinkles of the film with a known widening apparatus such as a wiping apparatus. In order to stabilize the film transportation in the treatment bath, a water stream in a swirling bath is controlled by an underwater shower or an EPC apparatus (Edge Position Control apparatus: detecting the end of the film to prevent meandering of the film) Device) or the like may be used in combination. In this process, since the film swells and expands even in the running direction of the film, in order not to elongate the film in the carrying direction when the film is not actively stretched, for example, the speed of the transport roll before and after the treatment tank is controlled It is desirable to take measures such as the following. The swelling treatment bath to be used may be an aqueous solution in which boric acid, a chloride, an inorganic acid, an inorganic salt, a water-soluble organic solvent, alcohols and the like are added in the range of 0.01 wt% to 10 wt% It is possible.

The dyeing step with the dichroic dye is carried out for the purpose of adsorbing and orienting a 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 melting of the substrate film, When iodine is used as the dichroic dye, for example, the temperature is 10 ° C to 45 ° C, preferably 20 ° C to 35 ° C, and the concentration of iodine / KI / water is 0.003 to 0.2 / 0.1 to 10/100 And the immersion treatment is performed 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. In addition, other iodides may be used in combination with potassium iodide. Further, compounds other than iodide such as boric acid, zinc chloride, cobalt chloride, etc. may be coexistent. When boric acid is added, it is distinguished from the following boric acid treatment in that it contains iodine. If it contains iodine in an amount of 0.003 part by weight or more based on 100 parts by weight of water, it 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 concentration of the dichroic dye / water is 0.001 to 0.1 / To 600 seconds, preferably 60 seconds to 300 seconds. The aqueous solution of the dichroic dye to be used may have a dyeing assistant and the like, and may contain an inorganic salt such as sodium sulfate, a surfactant, and the like. The dichroic dye may be used singly or two or more dichroic dyes may be used at the same time.

In the case of treating the polyvinyl alcohol film in the order of the swelling treatment, the dyeing treatment and the boric acid treatment, the film is usually stretched in a dyeing bath. The stretching magnification of the totalization up to the dyeing treatment (in the case of no stretching treatment until this treatment, the stretching magnification in this treatment) is usually 1.6 to 4.5 times, preferably 1.8 to 4.0 times. In addition, when the stretching magnification of the integration up to the dyeing treatment is less than 1.6 times, the frequency of breakage of the film is increased, and the yield tends to deteriorate.

The boric acid treatment is carried out by immersing a polyvinyl alcohol-based film dyed with a dichroic dye into an aqueous solution containing boric acid in an amount of, for example, 1 to 10 parts by weight per 100 parts by weight of water. When the dichroic dye is iodine, iodide is preferably contained in an amount of 1 to 30 parts by weight. Examples of the 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 and the like may be coexistent.

This boric acid treatment is carried out for water resistance and color adjustment (such as preventing blue light) by crosslinking. In the case of water resistance by crosslinking, a crosslinking agent such as glyoxal, glutaraldehyde and the like may be used in addition to boric acid or boric acid, if necessary. On the other hand, the boric acid treatment for water resistance is often referred to as a water resistance treatment, a cross-link treatment, an immobilization treatment or the like. The boric acid treatment for color adjustment may also be referred to as a complementary coloring treatment or a re-dyeing treatment.

This boric acid treatment is carried out by suitably changing the concentration of boric acid and iodide and the temperature of the treatment bath, depending on the purpose. The boric acid treatment for moisture resistance and the boric acid treatment for color adjustment are not particularly discriminated but are carried out under the following conditions. In the case where the original film is subjected to swelling, dyeing or boric acid treatment. When the boric acid treatment is aimed at water resistance by crosslinking, 3 parts by weight to 10 parts by weight of boric acid and 1 part by weight By weight of boric acid treatment bath containing 20 parts by weight or less of boric acid is usually used at a temperature of 50 to 70 캜, preferably 53 to 65 캜. The immersion time is usually about 10 seconds to 600 seconds, preferably 20 seconds to 300 seconds, and more preferably 20 seconds to 200 seconds. On the other hand, when dyeing and boric acid treatment are carried out in advance in the stretched film, the temperature of the boric acid treatment bath is usually 50 ° C to 85 ° C, preferably 55 ° C to 80 ° C.

After boric acid treatment for moisture resistance, boric acid treatment for color adjustment may be performed. For example, when a 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 per 100 parts by weight of water is used for this purpose. , And at a temperature of 10 ° C to 45 ° C. The immersion time is usually about 1 second to about 300 seconds, preferably about 2 seconds to about 100 seconds.

These boric acid treatments may be performed a plurality of times, usually in two to five times. In this case, the composition and temperature of the aqueous solution of each boric acid treatment tank to be used may be the same or different from each other within the above-mentioned range. The boric acid treatment for water resistance and the boric acid treatment for color adjustment may be performed in a plurality of steps, respectively.

After the boric acid treatment, it is cleaned. The cleaning treatment is carried out, for example, by immersing a polyvinyl alcohol-based film treated with boric acid for water resistance and / or color tone adjustment in water, spraying water as a shower, or using immersion and spray in combination. The temperature of the water in the washing treatment is usually about 2 to 40 占 폚 and the immersion time is preferably about 2 to 120 seconds. Thereafter, the polarizing film can be obtained by drying the polyvinyl alcohol-based film in a drying furnace at a temperature of about 40 ° C to 100 ° C for about 60 seconds to 600 seconds.

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

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an explanatory view showing one embodiment of a uniaxial stretching treatment method in a case where a uniaxial stretching treatment is carried out in parallel with a swelling treatment, a dyeing treatment or a boric acid treatment. 1, the 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 downstream side nip roll 2' is higher than the peripheral speed of the upstream side nip roll 2 So that 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 treating boric acid, and the treatment tank 10 is filled with treatment solution 4 for dipping . In Fig. 1, it is preferable that all of the roll formed products constituting the nip rolls 2, 2 'are formed with the rubber layer 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 nip rolls 2 and 2 'made of a roll formed product using the rubber composition can continue to be used under an environment in which a dyeing solution or a boric acid treatment solution adheres It can withstand long-term use.

The polyvinyl alcohol film (1) is introduced into the treatment solution (4) by a plurality of guide rolls (5). In the present invention, the guide roll 5 may be formed with a rubber layer made of the rubber composition according to the present invention on its surface. Since the rubber composition according to the present invention is excellent in chemical resistance and abrasion resistance, the guide roll 5 formed by using the rubber composition according to the present invention can withstand long-term use even if it is immersed in the treatment solution 4 .

1, both of the upstream and downstream nip rolls 2 and 2 'are provided in the gas. However, even if one or both of the nip rolls 2 and 2' are installed in the treatment solution 4 good.

A polarizing plate is obtained by bonding a protective film to at least one surface of the thus prepared polarizing film with an adhesive. As the protective film, for example, a film comprising an acetylcellulose resin such as triacetylcellulose or diacetylcellulose, a film comprising a polyester resin such as polyethylene terephthalate, polyethylene naphthalate or polybutylene terephthalate, a film of a polycarbonate resin A film made of a cycloolefin resin, and the like. Examples of commercially available thermoplastic cycloolefin resins include "Topas" (trademark registered) sold by Ticona of Germany, "Aton" (registered trademark) sold by JSR Corporation, "Zeonoa" and "Zeonex" (All trademark registered) sold by Nippon Zeon Co., Ltd. and "Apel" (Trademark registered) sold by Mitsui Gagaku Co., Such a cycloolefin-based resin is formed into a protective film, and known methods such as a solvent casting method and a melt extrusion method are suitably used for the film formation. The formed cycloolefin resin film is also commercially available, and examples thereof include "Essen" and "SCA40" sold by Sekisui Chemical Co., Ltd.

In the present invention, the protective film may have an optical function such as a function as a retardation film, a function as a luminance enhancement film, a function as a reflective film, a function as a transflective film, a function as a diffusion film, have. In this case, for example, by laminating an optical functional film such as a retardation film, a luminance enhancement film, a reflection film, a transflective film, a diffusion film, and an optical compensation film on the surface of a protective film, This function may be imparted to the protective film itself. Further, the protective film itself may have a plurality of functions such as a diffusion film having the function of a brightness enhancement film.

Example

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[Example 1]

"3090EM" (diene type: ethylidene norbornene, Mooney viscosity: 87) manufactured by Mitsui Chemicals, Inc. as the EPDM (ethylene-propylene-diene copolymer rubber) Vulkanox MB2 " (2-mercaptomethylbenzimidazole) manufactured by LANXESS, which is a benzimidazole-based compound, as an antioxidant, a vulcanizing agent (trade name: (2,5-dimethyl-2,5-di (t-butylperoxy) hexane) manufactured by Idemitsu Kosan Co., Ltd., which is an organic peroxide, manufactured by Nippon Oil Co., Quot; PW380 " (paraffin oil) as a plasticizer, stearic acid manufactured by Nippon Seika Kogyo Co., Ltd. as a vulcanization accelerator, zinc oxide as an inorganic filler manufactured by HAKUSUITECH KABUSHIKI KAISHA, s Ter-TMP " (trimethylolpropane trimethacrylate) was used as the crosslinking aid.

The following prescription:

EPDM 100 parts by weight

Carbon black 50 parts by weight

Aging inhibitor 1 part by weight

Vulcanization 7 parts by weight

Plasticizer (paraffin oil) 10 parts by weight

1 part by weight of a vulcanization accelerator (stearic acid)

5 parts by weight of inorganic filler (zinc oxide)

Crosslinking aid (trimethylolpropane trimethacrylate) 3.4 parts by weight

≪ tb > < tb >

The rubber composition to which each of the above components was added was sufficiently kneaded with a rubber kneader, and the kneaded product was placed on a calendar machine to prepare an unvulcanized rubber sheet having a thickness of 1.5 mm. The surface was blast-treated in advance, and the rubber sheet was laminated several times on the core coated with an adhesive to cover the rubber. Thus, a rubber roll having a rubber layer having a thickness of 35 mm was formed on the surface. Subsequently, the roll was vulcanized at a pressure of 0.5 MPa and a temperature of 160 DEG C for 480 minutes, and after cooling, polishing was performed to obtain rubber roll of Example 1 having a rubber layer of 25 mm thickness on the roll surface.

[Example 2]

APMA "(N- (4-anilinophenyl) methacrylamide) manufactured by Seiko Kagaku Co., Ltd., which is a reactive antioxidant, was used as the antioxidant, the same materials as in Example 1 were used.

The following prescription:

EPDM 100 parts by weight

Carbon black 50 parts by weight

Antioxidant 2 parts by weight

Vulcanization 7 parts by weight

Plasticizer (paraffin oil) 10 parts by weight

1 part by weight of a vulcanization accelerator (stearic acid)

5 parts by weight of inorganic filler (zinc oxide)

Crosslinking aid (trimethylolpropane trimethacrylate) 3.4 parts by weight

, The rubber composition of Example 2 was blended.

The rubber roll of Example 2 was obtained in the same manner as in Example 1, except that the rubber composition to which each component was added was used.

[Comparative Example 1]

EP65 "(diene type: ethylidene norbornene, Mooney viscosity: 74) manufactured by JSR Corporation as EPDM (ethylene-propylene-diene copolymer rubber)," Syst 3 " TMDQ " (2,2,4-trimethyl-1,2-dihydroquinoline (product name) manufactured by Ouchi Shinko Chemical Co., Ltd.) as an antioxidant The same material as in Example 1 was used.

The following prescription:

EPDM 100 parts by weight

Carbon black 55 parts by weight

Aging inhibitor 1 part by weight

Vulcanization 7 parts by weight

Plasticizer (paraffin oil) 10 parts by weight

1 part by weight of a vulcanization accelerator (stearic acid)

5 parts by weight of inorganic filler (zinc oxide)

Crosslinking aid (trimethylolpropane trimethacrylate) 3.4 parts by weight

, The rubber composition of Comparative Example 1 was blended.

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

[Comparative Example 2]

(Arithmetic mean particle diameter: 28 nm, DBP absorption amount: 101 cm 3/100 g) manufactured by Tokai Carbon Kabushiki Kaisha, and TMDQ (manufactured by Ouchi Shinko Chemical Co., Ltd.) as an antioxidant 2,2,4-trimethyl-1,2-dihydroquinoline polymer) was used, the same material as in Example 1 was used.

The following prescription:

EPDM 100 parts by weight

Carbon black 55 parts by weight

Aging inhibitor 1 part by weight

Vulcanization 7 parts by weight

Plasticizer (paraffin oil) 10 parts by weight

1 part by weight of a vulcanization accelerator (stearic acid)

5 parts by weight of inorganic filler (zinc oxide)

Crosslinking aid (trimethylolpropane trimethacrylate) 3.4 parts by weight

, The rubber composition of Comparative Example 2 was blended.

The rubber composition of Comparative Example 2 was obtained in the same manner as in Example 1, using the rubber composition to which each of the above components was added.

[Comparative Example 3]

The same material as in Example 1 was used except that "EP65" (diene type: 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

Aging inhibitor 1 part by weight

Vulcanization 7 parts by weight

Plasticizer (paraffin oil) 10 parts by weight

1 part by weight of a vulcanization accelerator (stearic acid)

5 parts by weight of inorganic filler (zinc oxide)

Crosslinking aid (trimethylolpropane trimethacrylate) 3.4 parts by weight

, The rubber composition of Comparative Example 3 was blended.

The rubber composition of Comparative Example 3 was obtained in the same manner as in Example 1, except that the rubber composition to which each of the above components was added was used.

[Comparative Example 4]

The same materials as in Example 1 were used, except that "Syst 3" (Arithmetic mean particle diameter: 28 nm, DBP absorption amount: 101 cm 3/100 g) manufactured by Tokai Carbon Co., Ltd. was used as the carbon black.

The following prescription:

EPDM 100 parts by weight

Carbon black 55 parts by weight

Aging inhibitor 1 part by weight

Vulcanization 7 parts by weight

Plasticizer (paraffin oil) 10 parts by weight

1 part by weight of a vulcanization accelerator (stearic acid)

5 parts by weight of inorganic filler (zinc oxide)

Crosslinking aid (trimethylolpropane trimethacrylate) 3.4 parts by weight

, The rubber composition of Comparative Example 4 was blended.

The rubber composition of Comparative Example 4 was obtained in the same manner as in Example 1 by using the rubber composition to which each component was added.

[Comparative Example 5]

"EP65" (diene type: ethylidene norbornene, Mooney viscosity: 74) manufactured by JSR Corporation as EPDM (ethylene-propylene-diene copolymer rubber), "TMDQ Quot; (2,2,4-trimethyl-1,2-dihydroquinoline polymer) was used.

The following prescription:

EPDM 100 parts by weight

Carbon black 50 parts by weight

Aging inhibitor 1 part by weight

Vulcanization 7 parts by weight

Plasticizer (paraffin oil) 10 parts by weight

1 part by weight of a vulcanization accelerator (stearic acid)

5 parts by weight of inorganic filler (zinc oxide)

Crosslinking aid (trimethylolpropane trimethacrylate) 3.4 parts by weight

, The rubber composition of Comparative Example 5 was blended.

The rubber composition of Comparative Example 5 was obtained in the same manner as in Example 1 by using the rubber composition to which each of the above components was added.

[Comparative Example 6]

EP65 "(diene type: ethylidene norbornene, Mooney viscosity: 74) manufactured by JSR Corporation as EPDM (ethylene-propylene-diene copolymer rubber)," Syst 3 " The average particle size of the particles: 28 nm, the DBP absorption: 101 cm < 3 > / 100 g) was used.

The following prescription:

EPDM 100 parts by weight

Carbon black 55 parts by weight

Aging inhibitor 1 part by weight

Vulcanization 7 parts by weight

Plasticizer (paraffin oil) 10 parts by weight

1 part by weight of a vulcanization accelerator (stearic acid)

5 parts by weight of inorganic filler (zinc oxide)

Crosslinking aid (trimethylolpropane trimethacrylate) 3.4 parts by weight

, The rubber composition of Comparative Example 7 was blended.

The rubber composition of Comparative Example 6 was obtained in the same manner as in Example 1 by using the rubber composition to which the respective components were added.

<Measurement of Mooney Viscosity of EPDM>

The Mooney viscosity of the EPDM was measured using a L-rotor of Muni Biscometer SMV-300 manufactured by Shimadzu Seisakusho Co., Ltd. in accordance with JIS K 6300, and the preheating temperature was 1 minute, the measurement temperature was 100 占 폚, .

&Lt; Abrasion resistance test &

The rubber compositions of Example 1 and Comparative Examples 1 to 6 were thoroughly kneaded with a rubber kneader and then hooked to a calendar machine to prepare an unvulcanized rubber sheet having a thickness of 2.2 mm and a rubber sheet of JIS K 6299 , Vulcanization was carried out at a vulcanization temperature of 170 占 폚 to obtain a rubber sheet having a thickness of 2 mm. The rubber sheet was polished for 6 minutes at a press load of 3.62 kg using a polishing cloth AA-240 according to JIS K 6264, and the mass before and after polishing was measured. Density, and the wear volume was determined.

<Liquid drug test>

Test specimens of 20 mm x 50 mm and a dumbbell-shaped three-arc type were prepared from the rubber sheet composed of the compositions of Examples 1 and 2 and Comparative Examples 2 to 6. Subsequently, the test piece was immersed in an aqueous solution at 95 ± 1 ° C. 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 Co., Respectively.

On the other hand, unless otherwise noted, each test piece is the same as Examples 1 and 2 and Comparative Examples 1 to 6, which are the same as the corresponding rubber rolls. 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 can be seen that Examples 1 and 2 are superior to Comparative Examples 1 to 6 in abrasion resistance.

[Example 3]

(Production of polarizing film)

A polyvinyl alcohol film (Kurarabinetron VF-PS # 7500, degree of polymerization: 2,400, degree of saponification: 99.9 mol% or more) having a thickness of 75 탆 was immersed in pure water at 30 캜 for about 130 seconds while keeping the film stretched The film was sufficiently swollen. Next, uniaxial stretching was carried out while dying in an aqueous solution of iodine / potassium iodide / water in a weight ratio of 0.02 / 1.5 / 100.

Thereafter, the film was immersed in a boric acid cross-linking 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 54 DEG C for about 39 seconds, and subjected to cross-linking treatment, Uniaxial stretching was carried out until the film was stretched. At that time, the nip rolls made up of the rubber roll obtained in Example 1 were provided before and after the boric acid crosslinking treatment tank, respectively, and uniaxial stretching was carried out. Subsequently, cleaning treatment was performed for 9 seconds in pure water at 15 占 폚. Next, the film was dried at a temperature of 60 DEG C for 2 minutes to obtain a polarizing film.

The polarizing film was produced continuously for 12 weeks by using the manufacturing process of Example 3, but no trouble such as film breakage occurred. On the other hand, when the nip roll of Comparative Example 1 was used, film breakage often occurred during the same period of operation.

[Industrial Availability]

The rubber composition of the present invention is useful for the formation of rubber rolls used in the production of polarizing films.

1: polyvinyl alcohol film 2, 2 ': nip roll
4: Treatment solution 10: Treatment tank

Claims (5)

A rubber composition comprising a vulcanizing agent, carbon black, and an antioxidant in combination with an ethylene-propylene-diene copolymer rubber,
Wherein the ethylene-propylene-diene copolymer rubber has a Mooney viscosity of 80 or more,
Wherein the carbon black has an arithmetic average particle diameter of 25 nm or less,
Wherein the antioxidant is a benzimidazole-based compound. A rubber composition comprising a vulcanizing agent, carbon black, and an antioxidant in combination with an ethylene-propylene-diene copolymer rubber,
Wherein the ethylene-propylene-diene copolymer rubber has a Mooney viscosity of 80 or more,
Wherein the carbon black has an average particle diameter of 25 nm or less,
Wherein the anti-aging agent is a reactive anti-aging agent. The vulcanizing agent according to claim 1 or 2, wherein the vulcanizing agent is used in an amount of 1 part by weight to 10 parts by weight, the carbon black is used in an amount of 30 parts by weight to 90 parts by weight based on 100 parts by weight of the ethylene-propylene- And 0.5 to 3.0 parts by weight of an antioxidant. A roll formed article used in a production process of a polarizing film having a rubber layer formed on the surface of the rubber composition according to any one of claims 1 to 3. A manufacturing method for producing a polarizing film by performing a swelling treatment, a dyeing treatment, a boric acid treatment, and a cleaning treatment on a polyvinyl alcohol film in this order,
The uniaxial stretching process is performed in parallel with at least one of these processes or separately from these processes using the difference in peripheral speed of the two nip rolls,
Wherein at least one of the roll formed articles constituting the nip roll is the roll shaped article according to claim 4.

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