JP2012232517A - Molding member for vulcanization - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding member (molding member for vulcanization) in which tear resistance and release properties are remarkably improved even in the vulcanization of an unvulcanized molded body formed of a rubber composition containing an organic peroxide.SOLUTION: A jacket 10 as the molding member is formed of the cross-linked body of the rubber composition which contains butyl rubber, an ethylene-α-olefin elastomer and a cross-linking agent (sulfur and a resin cross-linking agent) and in which the ratio of the butyl rubber to the ethylene-α-olefin elastomer is 10/90-60/40 (by mass) and thereby, the tear resistance and the release properties to a belt sleeve 7 as the vulcanized molding are improved and the usage count (life) is remarkably improved. The resin cross-linking agent can contain an alkyl phenol-formaldehyde resin and a cross-linking assistant.

Description

  The present invention relates to a molded member (vulcanized molded member) useful for vulcanizing an unvulcanized molded body (such as a belt sleeve). More specifically, an unvulcanized molded body in which the rubber layer is formed of a rubber composition containing an organic peroxide [cylindrical belt sleeve (power transmission belt such as V-ribbed belt, low-edge belt, conveyor belt, etc.) ] Is used for vulcanization (or cross-linking), and is not easily damaged even after repeated use (a vulcanization molding member such as a belt sleeve vulcanization jacket).

  In recent years, due to social demands for energy saving and downsizing, the ambient temperature around the engine compartment of automobiles has risen compared to the prior art, and as the ambient temperature rises, the operating temperature of the power transmission belt has also increased. I came. Conventionally, natural rubber, styrene-butadiene rubber, chloroprene rubber and the like have been mainly used for power transmission belts. However, as demand for materials that do not include environmentally hazardous substances increases, α-olefin elastomers have been adopted, and organic peroxides have been used as crosslinking agents for the polymers.

  The power transmission belt is formed by winding each member constituting the belt around a cylindrical mold in order, and vulcanizing the molded unvulcanized belt sleeve with a rubber jacket on the outer peripheral side. It is manufactured by extracting (or releasing) the jacket after vulcanization. In this manufacturing process, the work of removing the jacket after vulcanization is a very heavy labor, and particularly when the release property of the jacket is inferior, the workability, particularly the workability of an automated production line is significantly reduced. In addition, since the jacket is repeatedly used for vulcanization of the belt sleeve many times, there is a problem of breakage due to deterioration over time and releasability due to repeated use.

  Conventionally, butyl rubber having excellent heat resistance and low gas permeability has been used as the rubber material used for the jacket. However, when a rubber composition in which an organic peroxide is blended with butyl rubber as a crosslinking agent is used as the rubber layer of the belt sleeve, the butyl rubber is attacked by radicals generated by the decomposition of the organic peroxide and mainly undergoes a decomposition reaction. Wake up. In particular, when a rubber layer made of a rubber composition containing an organic peroxide directly adheres to a jacket made of butyl rubber, the butyl rubber of the jacket is damaged. Therefore, as compared with a belt sleeve made of a conventional sulfur-crosslinked rubber composition, the inner peripheral surface of the jacket (the surface to which the rubber layer of the belt sleeve is in close contact) is significantly deteriorated and the number of usable repetitions is shortened. Furthermore, since the outer peripheral surface of the jacket is directly exposed to pressurized steam during vulcanization, the butyl rubber is softened or deteriorated to develop adhesiveness, thereby impairing workability.

  Therefore, in JP 2009-34979 A (Patent Document 1), in order to improve the releasability of the jacket and increase the number of uses, butyl rubber and an ethylene-α-olefin elastomer (EPDM having an iodine value of 10 or less) are disclosed. It has been proposed to form a vulcanization jacket using a rubber composition obtained by mixing a mixture of styrene and the like at a ratio of 65:30 to 90: 5. The jacket of this document can improve the releasability from the belt sleeve, and is hard to break and can improve durability (life).

  However, when this jacket is used to vulcanize a belt sleeve formed of a rubber composition containing an organic peroxide as a cross-linking agent, there is a problem in that the tear resistance due to thermal aging is low and sudden cracks occur. . Such a problem occurs not only in the vulcanization of the belt sleeve, but also in a vulcanized molded member that vulcanizes in contact with an unvulcanized molded body of a rubber composition containing an organic peroxide.

JP 2009-34979 A (Claims, [Effects of the Invention])

  Therefore, the object of the present invention is that the tear resistance and releasability are greatly improved even when subjected to vulcanization of an unvulcanized molded body (such as a belt sleeve) formed of a rubber composition containing an organic peroxide. Another object of the present invention is to provide a method for improving mold release property or tearability of a molded member (a vulcanized molded member such as a vulcanization jacket) and an unvulcanized molded body (such as a belt sleeve).

  Another object of the present invention is to provide a molded member for vulcanization (such as a vulcanization jacket) that can be repeatedly used for vulcanization of an unvulcanized molded body (such as a belt sleeve) over a long period of time and can greatly improve the number of uses (life). ) To provide.

  Still another object of the present invention is to provide a molded member for vulcanization (a jacket for vulcanization) that can maintain predetermined rubber characteristics and tear resistance even without being repeatedly used under vulcanization conditions and does not generate cracks. Etc.).

  Another object of the present invention is to provide a molded member for vulcanization (such as a vulcanization jacket) that can ensure high hardness in addition to the above characteristics.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have found that the ratio of butyl rubber to ethylene-α-olefin elastomer is a vulcanized molded member (vulcanized jacket) for a vulcanized molded body (such as a belt sleeve). Etc.), if the ratio of α-olefin elastomer to butyl rubber is increased, vulcanized molded parts (vulcanized jackets, etc.) for vulcanized molded bodies (belt sleeves, etc.) The releasability and tear resistance of the resin are greatly improved, especially when cross-linking with a specific cross-linking system, the above characteristics are greatly improved, and the number of times the vulcanized molded member (such as a vulcanizing jacket) is used (life) The present invention has been completed.

  That is, the vulcanized molded member (jacket or the like) of the present invention is a molded member (tubular jacket or the like) for vulcanizing the unvulcanized molded body in a state of being in contact with the unvulcanized molded body (belt sleeve or the like). Vulcanized molded member), which contains butyl rubber, an ethylene-α-olefin elastomer, sulfur and a resin cross-linking agent, and butyl rubber and ethylene-α-olefin elastomer are the former / the latter = 10 / 90-60 / 40 ( It is formed of a crosslinked product of a rubber composition contained at a ratio of (mass ratio). Since this vulcanized molded member (such as a vulcanized jacket) has a large proportion of ethylene-α-olefin elastomer relative to butyl rubber, the vulcanized molded body (such as an unvulcanized belt sleeve) is vulcanized. The resistance of the molded member (vulcanized molded member) to the action of the organic peroxide can be improved (tear resistance, release property, softening deterioration, etc.), and the number of use can be greatly increased. In addition, since the sulfur and the resin crosslinking agent are used as a crosslinking agent, the rubber composition can be crosslinked in a complex manner, and physical properties (hardness, elongation, etc.) and resistance to repeated use under vulcanization (high temperature environment) conditions. The tearing force can be maintained, and early breakage due to cracking can be prevented. The resin crosslinking agent may contain an alkylphenol / formaldehyde resin and a crosslinking aid (such as a halogen-containing compound). By using an alkylphenol / formaldehyde resin and a crosslinking aid in combination, sufficient hardness can be secured even if an alkylphenol / formaldehyde resin is used.

  More specifically, the molded member (molded member for vulcanization) of the present invention covers an unvulcanized molded body having an unvulcanized rubber layer as an outer layer or is in contact with the unvulcanized molded body. A molded member for vulcanization (a molded member for vulcanization) comprising butyl rubber, an ethylene-α-olefin elastomer, sulfur as a crosslinking agent and a resin crosslinking agent, and butyl rubber, an ethylene-α-olefin elastomer, The ratio of the former is the former / the latter = 10/90 to 60/40 (mass ratio), and the resin crosslinking agent is a crosslinked product of a rubber composition containing an alkylphenol / formaldehyde resin and a crosslinking aid (such as a halogen-containing compound). It may be formed. The molded member of the present invention is useful as a cylindrical jacket for covering and vulcanizing an unvulcanized belt sleeve as an unvulcanized molded body.

  The molded member (a molded member for vulcanization such as a jacket) of the present invention is a rubber layer in which an outer layer of an unvulcanized molded body (such as an unvulcanized belt sleeve) is formed of a rubber composition containing an organic peroxide. Even if it exists, it can be used repeatedly for a long period of time, maintaining high mold release property and tear resistance. Therefore, the present invention also includes a method for improving the releasability of a molded member (vulcanized molded member) from a vulcanized molded body (such as a belt sleeve) or the tearability of the molded member (vulcanized molded member). To do. In this method, an unvulcanized molded body (such as an unvulcanized belt sleeve) having an unvulcanized rubber layer formed of a rubber composition containing an organic peroxide as an outer layer and a molded member (such as a cylindrical jacket) The unvulcanized molded body is placed in contact with the molded member for vulcanization or by covering the unvulcanized molded body (such as an unvulcanized belt sleeve) with a molded member (a vulcanized molding member such as a cylindrical jacket). Vulcanization is performed to improve the releasability of the molded member (vulcanized molded member) from the vulcanized molded body or the tearability of the molded member (vulcanized molded member). And the said shaping | molding member (molding member for vulcanization | cure) contains butyl rubber, ethylene-alpha-olefin elastomer, and a crosslinking agent, and the ratio of butyl rubber and ethylene-alpha-olefin elastomer is the former / the latter = 10 / 90-60. The release property or tearability is improved by forming the rubber composition with a crosslinked composition of / 40 (mass ratio).

  In the present invention, since a molded member (vulcanized molded member) is formed from a rubber composition having a large proportion of ethylene-α-olefin elastomer relative to butyl rubber, it is not formed from a rubber composition containing an organic peroxide. Even when subjected to vulcanization of a vulcanized molded body (belt sleeve, etc.), the tear resistance and release properties can be greatly improved. Moreover, even if it repeatedly uses for vulcanization | cure of an unvulcanized molded object (belt sleeve etc.), the number of times of use (life) can be improved significantly, maintaining high tear resistance and mold release property. In addition, when sulfur and a resin crosslinking agent are used in combination as a crosslinking agent and the rubber composition is crosslinked in a complex manner, physical properties (rubber properties such as hardness and elongation) in repeated use under vulcanization (high temperature environment) conditions, The tear resistance can be maintained, and early breakage due to cracking can be prevented. Furthermore, if the resin crosslinking agent is composed of an alkylphenol / formaldehyde resin and a crosslinking aid (halogen-containing compound), sufficient hardness can be secured even if a resin crosslinking agent is used.

FIG. 1 is a schematic view showing a belt sleeve formed on a mold surface. FIG. 2 is a sectional view showing a state in which the belt sleeve shown in FIG. 1 is accommodated in the jacket according to the present invention. FIG. 3 is a schematic cross-sectional view showing a V-ribbed belt.

  Hereinafter, an embodiment of the present invention will be described with reference to an example of a jacket used for vulcanization of a belt sleeve for obtaining a V-ribbed belt shown in FIG. FIG. 1 is a schematic view showing a state where a belt sleeve is formed on a cylindrical mold surface, and FIG. 2 is a schematic longitudinal sectional view showing a state where a belt sleeve formed on the mold surface of FIG. 1 is covered with a jacket. is there.

  The V-ribbed belt shown in FIG. 3 includes a rubberized canvas (reinforcing cloth) 3, an adhesive rubber layer 5 laminated on the rubberized canvas (reinforcing cloth), and a compressed rubber layer 6 laminated on the adhesive rubber layer. A V-shaped groove is formed in the compressed rubber layer 6. Further, the core 4 is embedded in the adhesive rubber layer 5 in a spiral shape, and the compressed rubber layer 6 contains reinforcing short fibers.

  In the illustrated example, a release agent is applied to a molding surface 2 of a cylindrical mold 1 attached to a molding machine (not shown) and dried, and then a canvas with rubber (reinforcement) is applied to the release agent application surface. After winding the cloth 3), the core wire 4 is spun into a spiral shape, and a belt sleeve 7 is formed by winding a laminated sheet in which a sheet-like adhesive rubber layer 5 and a sheet-like compressed rubber layer 6 are laminated in advance. ing. In this example, the sheet-like adhesive rubber layer 5 and the sheet-like compressed rubber layer 6 are each formed of a rubber composition containing an ethylene-α-olefin elastomer.

  After the mold 1 is detached from the molding machine, the outer peripheral surface of the compressed rubber layer 6 of the belt sleeve 7 is covered with a jacket 10 that is a hollow cylindrical body made of a rubber composition, and the belt sleeve 7 is covered with the jacket 10. Covered with. That is, the belt sleeve 7 is accommodated in the hollow jacket 10 with the inner wall of the jacket 10 in contact with the compressed rubber layer 6 of the belt sleeve 7. The belt sleeve 7 is attached to a vulcanization unit (vulcanization can) in a state where the jacket 10 is covered (in a state where the belt sleeve 7 is accommodated or attached in the jacket 10), and is vulcanized under normal conditions. In this example, flanges 11 are provided at both end edges in the axial direction of the jacket 10 for sealing the inside during vulcanization by a sealing lid or the like. The flange 11 is not always necessary.

  When the vulcanization process is completed with the unvulcanized belt sleeve 7 accommodated in the jacket 10, the jacket 10 is extracted from the vulcanized belt sleeve 7 and the belt sleeve 7 is obtained. At that time, the jacket 10 is required to have high tear resistance, releasability from the vulcanized belt sleeve 7, deterioration resistance in the vulcanization process, and the like. Hereinafter, the belt sleeve and the jacket will be described in detail.

[Belt sleeve]
The rubber composition forming the outer layer (compressed rubber layer 6) of the belt sleeve 7 is not particularly limited, but usually a rubber composition containing a rubber component and a vulcanizing agent or a crosslinking agent is used. In particular, the present invention forms an outer layer (unvulcanized rubber layer) of an unvulcanized belt sleeve with a rubber composition (peroxide vulcanized rubber composition) containing a peroxide, Useful for vulcanizing or crosslinking the outer layer.

  Examples of the rubber component of the rubber composition include rubbers that can be vulcanized or crosslinked with peroxides, such as diene rubbers (natural rubber, isoprene rubber, butadiene rubber, chloroprene rubber, styrene butadiene rubber (SBR), acrylonitrile butadiene rubber ( Nitrile rubber), ethylene-α-olefin elastomer, etc.), acrylic rubber, silicone rubber, urethane rubber, fluorine rubber and the like. These rubber components can be used alone or in combination of two or more.

A preferable rubber component of the compressed rubber layer 6 is an ethylene-α-olefin elastomer (ethylene-α-olefin rubber), for example, ethylene-α-olefin rubber, ethylene-α-olefin-diene rubber. Examples of the α-olefin include chain α-C _3-12 olefins such as propylene, butene, pentene, methylpentene, hexene, and octene. The α-olefin can be used alone or in combination of two or more. Of these α-olefins, α-C _3-4 olefins (particularly propylene) such as propylene are preferred. Examples of the diene monomer usually include non-conjugated diene monomers such as dicyclopentadiene, methylene norbornene, ethylidene norbornene, 1,4-hexadiene, and cyclooctadiene. These diene monomers can be used alone or in combination of two or more. As typical ethylene-α-olefin elastomer (ethylene-α-olefin rubber), for example, ethylene-α-olefin rubber (ethylene-propylene rubber (EPR)), ethylene-α-olefin-diene rubber (ethylene-propylene) -A diene monomer (EPDM etc.) etc. can be illustrated etc. A preferable ethylene-alpha-olefin elastomer is EPDM.

  In the ethylene-α-olefin rubber, the ratio (mass ratio) of ethylene and α-olefin is the former / the latter = 40/60 to 90/10, preferably 45/55 to 85/15 (for example, 50/50 to 82/18), more preferably 55/45 to 80/20 (for example, 55/45 to 75/25). The proportion of diene can be selected from a range of about 4 to 15% by mass, for example, 4.2 to 13% by mass (for example, 4.3 to 12% by mass), preferably 4.4 to 11.5% by mass. % (For example, 4.5-11 mass%) may be sufficient. The iodine value of the ethylene-α-olefin rubber containing the diene component may be, for example, about 3 to 30 (preferably 5 to 25, more preferably 10 to 20).

  The rubber composition of the compressed rubber layer 6 contains an organic peroxide as a crosslinking agent. As the organic peroxide, a peroxide usually used for crosslinking of rubber and resin, for example, hydroperoxide (t-butyl hydroperoxide, 1,1,3,3-tetrabutyl hydroperoxide, t-amyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, etc.); diacyl peroxide (dilauroyl peroxide, dibenzoyl peroxide, etc.); alkyl peroxy ester (t-butyl peroxyacetate, t- Butyl peroxybenzoate, t-amyl peroxybenzoate, etc.), peroxycarbonate (eg, t-butylperoxy 2-ethylhexyl carbonate); dialkyl peroxide [di-t-butyl peroxide, dicarbonate Ruperoxide, t-butylcumyl peroxide, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di (t-butylperoxy) Hexane, 1,3-di (2-t-butylperoxyisopropyl) benzene, di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, di- t-amyl peroxide, 1,3-bis (t-butylperoxyisopropyl) benzene, etc.]; peroxyketal (ethyl-3,3-di (t-butylperoxy) butyrate, etc.); ketone peroxide (methyl ethyl ketone) And peroxide). These organic peroxides can be used alone or in combination of two or more. Among these organic peroxides, diacyl peroxide, peroxyester, dialkyl peroxide (for example, dicumyl peroxide, t-butylcumyl peroxide, 1,1-di-butylperoxy-3,3,5) -Trimethylcyclohexane 2,5-dimethyl-2,5-di (t-butylperoxy) -hexane, 1,3-bis (t-butylperoxy-isopropyl) benzene, di-t-butyl peroxide, etc.) Is often used. In addition, the organic peroxide is preferably a peroxide having a half-life of about 150 to 250 ° C. (for example, 175 to 225 ° C.) by thermal decomposition.

  The amount of the organic peroxide added is about 1 to 8 parts by weight, preferably 1.2 to 5 parts by weight, more preferably 1.5 to 100 parts by weight of the rubber component (such as ethylene-α-olefin elastomer). It is about -4.5 mass parts (for example, 2-4.5 mass parts).

  The rubber composition may contain a co-crosslinking agent (cross-linking aid or co-vulcanizing agent). Examples of the co-crosslinking agent (crosslinking aid) include known crosslinking aids such as polyfunctional (iso) cyanurates [eg, triallyl isocyanurate (TAIC), triallyl cyanurate (TAC), etc.], polydienes (eg, 1,2-polybutadiene, etc.), unsaturated carboxylic acid metal salts [eg, zinc (meth) acrylate, magnesium (meth) acrylate, etc.], oximes (eg, quinone dioxime), guanidines (eg, Diphenylguanidine, etc.), polyfunctional (meth) acrylate [eg, ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, etc.], bismaleimides (aliphatic bismaleimide, For example, N, N′-1,2-ethylene bismaleimi 1,6′-bismaleimide- (2,2,4-trimethyl) cyclohexane and the like; arene bismaleimide or aromatic bismaleimide such as NN′-m-phenylene bismaleimide, 4-methyl-1,3 -Phenylalesmaleimide, 4,4'-diphenylmethane bismaleimide, 2,2-bis [4- (4-maleimidophenoxy) phenyl] propane, 4,4'-diphenyl ether bismaleimide, 4,4'-diphenylsulfone bismaleimide 1,3-bis (3-maleimidophenoxy) benzene), sulfur and the like. These crosslinking aids can be used alone or in combination of two or more. Of these crosslinking aids, bismaleimides (arene bismaleimides such as N, N′-m-phenylene dimaleimide or aromatic bismaleimides) are preferable. The addition of bismaleimides can increase the degree of crosslinking and prevent adhesive wear and the like.

  The ratio of the co-crosslinking agent (crosslinking aid) is, for example, 0.01 to 10 parts by mass (for example, 0.05 to 8 parts by mass), preferably 0 with respect to 100 parts by mass of the rubber component in terms of solid content. 0.1 to 5 parts by mass (for example, 0.5 to 4 parts by mass), more preferably about 1 to 3 parts by mass.

Further, the compressed rubber layer 6 may contain short fibers. Examples of short fibers include natural fibers (cotton, hemp, etc.), regenerated fibers (rayon, acetate, etc.), inorganic fibers (metal fibers, glass fibers, carbon fibers, etc.), synthetic fibers, etc. , Polyolefin fibers (polyethylene fibers, polypropylene fibers, etc.), styrene fibers, polyfluoroethylene fibers, acrylic fibers, vinyl alcohol fibers, polyester fibers (poly C _2-4 alkylene such as polyethylene terephthalate, polyethylene naphthalate) Arylate fibers, wholly aromatic polyester fibers such as liquid crystal polyester fibers), polyamide fibers (aliphatic polyamide fibers such as polyamide 6 and polyamide 66, wholly aromatic polyamide fibers such as aramid fiber), polyurethane fibers, etc. Etc. These fibers can be used alone or in combination of two or more. Among these fibers, cellulose fibers such as cotton and rayon, polyester fibers (polyethylene terephthalate fibers, etc.), polyamide fibers (aliphatic polyamide fibers such as polyamide 6, aramid fibers, etc.) are widely used.

  By mixing the short fibers, the side pressure resistance of the compression rubber layer of the transmission belt can be improved, and the surface of the compression rubber layer that becomes the contact surface with the pulley is ground with a grinder so that the short fibers protrude. The friction coefficient on the surface of the compressed rubber layer can be reduced, and noise during belt running can be reduced. Among these short fibers, an aramid short fiber having an aromatic ring in the molecule, being rigid and having high strength, and having high wear resistance is preferable. Aramid fibers are commercially available, for example, under the trade names “Conex”, “Nomex”, “Kevlar”, “Technola”, “Twaron”, and the like.

  The average fiber length of short fibers (such as aramid fibers) may be, for example, 1 to 20 mm, preferably 2 to 15 mm, and more preferably about 5 to 10 mm. The content of the short fiber is, for example, 1 to 50 parts by mass (for example, 1 to 30 parts by mass), preferably 5 to 40 parts by mass, and more preferably about 10 to 35 parts by mass with respect to 100 parts by mass of the rubber component. It is.

  Furthermore, the compressed rubber layer 6 may be provided with a vulcanization aid, a vulcanization accelerator, a vulcanization retarder, a reinforcing agent (such as silicon oxide such as carbon black and hydrous silica), and a filler (clay, carbonic acid) as necessary. Calcium, talc, mica, etc.), metal oxides (eg, zinc oxide, magnesium oxide, calcium oxide, barium oxide, iron oxide, copper oxide, titanium oxide, aluminum oxide), softeners (paraffin oil, process oil, etc.) Oils, etc.), processing agents or processing aids (stearic acid, metal stearates, waxes, paraffins, etc.), anti-aging agents, colorants, tackifiers, plasticizers, coupling agents (silane coupling agents, etc.) , Stabilizers (ultraviolet absorbers, antioxidants, ozone degradation inhibitors, thermal stabilizers, etc.), flame retardants, antistatic agents, and the like may be included. The metal oxide may act as a crosslinking agent.

  The addition amount of these components can be selected from a conventional range depending on the type. For example, the use amount of a reinforcing agent (carbon black, silica, etc.) is 10 to 100 mass with respect to 100 mass parts of the total amount of rubber components. Part (preferably 20 to 80 parts by mass, more preferably 30 to 70 parts by mass). Moreover, the usage-amount of a metal oxide (for example, zinc oxide etc.) is 1-15 mass parts with respect to 100 mass parts of total amounts of a rubber component, Preferably it is 2-10 mass parts, More preferably, it is 3-7. The amount used of the softener (oils such as paraffin oil) may be, for example, 1 to 30 parts by mass, preferably 5 to 25 parts by mass with respect to 100 parts by mass of the total amount of rubber components. More preferably, it may be about 10 to 20 parts by mass.

  A rubber composition similar to that of the compressed rubber layer 6 (a rubber composition containing a rubber component such as an ethylene-α-olefin elastomer) can also be used for the adhesive rubber layer 5. The rubber composition of the adhesive rubber layer 5 does not need to contain the short fibers, organic peroxides, crosslinking aids, and the like. If necessary, the content of the filler may be reduced. . Furthermore, the rubber composition of the adhesive rubber layer 5 may contain the vulcanization accelerator. Examples of the vulcanization accelerator include thiuram accelerators [for example, tetramethylthiuram monosulfide (TMTM), tetramethylthiuram disulfide (TMTD), tetraethylthiuram disulfide (TETD), tetrabutylthiuram disulfide (TBTD). ), Dipentamethylene thiuram tetrasulfide (DPTT), N, N′-dimethyl-N, N′-diphenyl thiuram disulfide, etc.], thiazole-based accelerators [for example, 2-mercaptobenzothiazol, 2 -Zinc salts of mercaptobenzothiazol, 2-mercaptothiazoline, dibenzothiazyl disulfide, 2- (4'-morpholinodithio) benzothiazole, etc.], sulfenamide accelerators [for example, N-cyclohexyl-2 -Benzothiazylsulfene Mido (CBS), N, N′-dicyclohexyl-2-benzothiazylsulfenamide, etc.], bismaleimide accelerators (for example, N, N′-m-phenylenebismaleimide, N, N′-1,2) -Ethylene bismaleimide etc.), guanidines (diphenyl guanidine, di-tolyl guanidine etc.), urea or thiourea accelerators (eg ethylene thiourea etc.), dithiocarbamates, xanthates and the like. These vulcanization accelerators can be used alone or in combination of two or more. Of these vulcanization accelerators, TMTD, DPTT, CBS and the like are widely used.

  The proportion of the vulcanization accelerator is, for example, 0.5 to 15 parts by mass, preferably 1 to 10 parts by mass, and more preferably 1.5 to 5 parts by mass with respect to 100 parts by mass of the rubber component in terms of solid content. It may be a degree.

Examples of the fibers constituting the core wire include the same fibers as described above. Among the fibers, from the viewpoint of reinforcing properties, synthesis of polyester fibers (polyalkylene arylate fibers), aramid fibers, etc. mainly comprising C _2-4 alkylene arylates such as ethylene terephthalate and ethylene-2,6-naphthalate. Inorganic fibers such as fibers, glass fibers, and carbon fibers are widely used, and polyester fibers (polyethylene terephthalate fibers, ethylene naphthalate fibers) and polyamide fibers are preferable because the belt slip ratio can be reduced. The fiber may be a multifilament yarn. The fineness of the multifilament yarn may be, for example, about 2000 to 10000 denier (particularly 4000 to 8000 denier).

  As the core wire, a twisted cord using multifilament yarn (for example, various twists, single twists, rung twists, etc.) can be used. The average wire diameter (fiber diameter of the twisted cord) of the core wire may be, for example, about 0.5 to 3 mm, preferably about 0.6 to 1 mm, and more preferably about 0.7 to 0.8 mm.

  In order to improve the adhesion to rubber, the core wire may be subjected to an adhesion treatment. In the adhesion treatment, generally, the fibers can be immersed in a resorcin-formalin-latex liquid (RFL liquid) and then dried by heating to form a uniform adhesive layer on the surface. In addition to this adhesion treatment, the core fiber is pretreated with a conventional adhesive component, for example, an epoxy compound (epoxy resin, etc.), a reactive compound (adhesive compound) such as an isocyanate compound, and then RFL. You may process with a liquid. The RFL liquid is a composition in which an initial condensate (prepolymer) of resorcin and formalin is mixed with latex. Examples of the latex include chloroprene, styrene-butadiene-vinylpyridine terpolymer, hydrogenated nitrile rubber (H-NBR), and NBR. The core wire may be embedded in the rubber layer after the adhesion treatment.

  When used as a power transmission belt, a core wire extending in the belt longitudinal direction may be embedded in the adhesive rubber layer 5. The core wire (or cord) is approximately the center in the thickness direction of the rubber layer 5, near the interface between the compressed rubber layer 6 and the adhesive rubber layer 5, and near the interface between the rubberized canvas (reinforcing fabric) 3 and the adhesive rubber layer 5. It may be embedded in the belt or at equal intervals in the width direction of the belt. The space | interval (spinning pitch) of the adjacent core wire is 0.5-2 mm, for example, Preferably it is 0.8-1.5 mm, More preferably, it is about 1-1.3 mm.

  The rubberized canvas 3 is obtained by treating a cloth material (preferably a woven cloth) such as a woven cloth, a wide-angle canvas, a knitted cloth, and a non-woven cloth with an RFL solution (such as a dipping treatment), followed by a rubber composition. (A rubber composition similar to that of the adhesive rubber layer 5 and the compressed rubber layer 6) can be obtained by friction coating or laminating.

[Jacket (Vulcanizing Jacket)]
The jacket 10 includes a rubber layer 13 made of a rubber composition containing butyl rubber and an ethylene-α-olefin elastomer. The degree of unsaturation (isoprene content) of butyl rubber (isobutylene-isoprene copolymer) is, for example, 0.1 to 3.5 mol% (for example, 0.5 to 2.5 mol%, preferably 0.7 to About 2 mol%). The Mooney viscosity (ML _{1 + 8} (125 ° C.)) of butyl rubber may be, for example, about 10 to 100 (eg, 20 to 75, preferably 25 to 65, more preferably 30 to 55). Furthermore, if necessary, the butyl rubber may be halogenated or partially crosslinked. The halogenated butyl rubber may be, for example, a chlorinated or brominated butyl rubber having a halogen content of about 0.5 to 2.5% by mass (for example, 1 to 2.2% by mass).

  Examples of the ethylene-α-olefin elastomer include the same ethylene-α-olefin elastomer as the compression rubber layer 6 of the belt sleeve (a copolymer of ethylene and the above-mentioned α-olefin, ethylene and the above-described α-olefin). Copolymers with the above-exemplified diene monomers can be used. Usually, ethylene-α-olefin rubber (such as ethylene-propylene rubber (EPR)), ethylene-α-olefin-diene rubber (ethylene-propylene-diene monomer (EPDM)) ) Etc.) are used. Moreover, the ratio (mass ratio) of ethylene and α-olefin and the ratio of diene are the same as described above. The iodine value of the ethylene-α-olefin rubber containing the diene component may be about 3 to 30 (preferably 5 to 25, more preferably 10 to 20) as described above. In the present invention, even an ethylene-α-olefin rubber having an iodine value exceeding 10 (for example, about 12 to 30, preferably about 15 to 20) can be used effectively, and is resistant to tearing, release, and repetition. The number of uses can be increased.

  In the vulcanization process in which the unvulcanized belt sleeve is accommodated in the jacket and the belt sleeve is vulcanized, the unvulcanized belt sleeve and the jacket are usually in contact with each other, and the rubber composition of the belt sleeve contains an organic peroxide. The jacket is decomposed by the attack of radicals generated by the decomposition of the organic peroxide, is deteriorated by curing, and the jacket tearability and the releasability of the jacket from the vulcanized belt sleeve are lowered. Therefore, in the present invention, by increasing the ratio of the ethylene-α-olefin elastomer to the butyl rubber, the ratio of the polymer chain that is decomposed by the attack of radicals generated by the decomposition of the organic peroxide in the vulcanization process is increased. This reduces the deterioration of the jacket (deterioration of the inner peripheral surface of the jacket), and improves the tear resistance of the jacket, the releasability of the jacket from the vulcanized belt sleeve, and the number of times the jacket is used (lifetime).

  The ratio (mass ratio) of butyl rubber to ethylene-α-olefin elastomer is the former / the latter = 10/90 to 60/40, preferably 15/85 to 55/45, more preferably about 20/80 to 50/50. It is. When the proportion of the ethylene-α-olefin elastomer is less than 40 parts by mass with respect to 100 parts by mass of the total amount of butyl rubber and ethylene-α-olefin elastomer, it is decomposed by the attack of radicals generated by the decomposition of the organic peroxide. The ratio of the polymer chain to be increased increases, and it becomes easy to break due to curing deterioration, and softening (adhesion) of the outer peripheral surface of the jacket occurs. On the other hand, when the amount of the ethylene-α-olefin elastomer is more than 90 parts by mass, the degradation of the polymer chain by the organic peroxide and the adhesion of the outer peripheral surface of the jacket due to the softening deterioration are suppressed, but the manufacture (moldability) of the jacket becomes difficult. Become.

  The rubber composition of the rubber layer 13 contains a crosslinking agent. The cross-linking agent may be various cross-linking agents, for example, the organic peroxide, metal oxide, quinone dioxime, etc., but sulfur (sulfur vulcanizing agent) and resin cross-linking agent are used in combination. Is preferred. In order to improve the use frequency (life) of the rubber composition for jackets, it is necessary to maintain physical properties (hardness, elongation) and tear resistance even when used repeatedly under vulcanization (high temperature environment) conditions. . When a resin crosslinking agent is used alone as a crosslinking agent for this rubber composition, the tear resistance due to thermal deterioration is reduced, and when it is repeatedly used under high temperature environmental conditions, it may be suddenly damaged. On the other hand, if sulfur is used alone, the tear resistance during heating can be ensured, but the elongation is reduced, and it becomes weak against repeated deformation against pressing. That is, during vulcanization, pressure is applied to the jacket by pressurized steam from the outer peripheral side to deform the jacket, and after vulcanization, the jacket is restored to its original shape, but is weak against repeated deformation due to pressing and pressing release. . On the other hand, when both are used in combination, they can be cross-linked to maintain their physical properties (hardness, elongation) and tear resistance even when used repeatedly under vulcanization (high temperature environment) conditions. Can be prevented.

  In general, sulfur crosslinking, organic peroxide crosslinking, quinoid crosslinking, resin crosslinking, and the like are known as rubber crosslinking methods. On the other hand, when two different types of rubbers are mixed at an arbitrary ratio and cross-linked by a common cross-linking agent (co-cross-linking), the characteristics of each rubber can be imparted. For this reason, if a common cross-linking agent can be used even for different types of rubber, a cross-linking reaction with the same chemical occurs between different types of rubber, and stabilization of performance can be expected. In the present invention, sulfur crosslinking and resin crosslinking are used as a common crosslinking agent between butyl rubber and ethylene-α-olefin elastomer (EPDM or the like), and butyl rubber and ethylene-α-olefin elastomer (EPDM or the like) are co-crosslinked.

  Examples of the sulfur-based vulcanizing agent include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, sulfur chloride (sulfur monochloride, sulfur dichloride, etc.), and the like. These sulfur vulcanizing agents can be used alone or in combination of two or more. Of these sulfur vulcanizing agents, colloidal sulfur and highly dispersible sulfur are preferred.

  The amount of sulfur (sulfur vulcanizing agent) used is 0.1 to 1 part by mass (for example, 0.2 to 0) with respect to 100 parts by mass of the total amount of butyl rubber and ethylene-α-olefin elastomer (such as EPDM). .8 parts by mass), preferably about 0.2 to 0.6 parts by mass.

As the resin crosslinking agent, an alkylphenol / formaldehyde resin (for example, an alkylphenol resin having a methylol group) is used. Examples of alkylphenols include linear or branched o-, p- or m-cresol, 3,5-xylenol, pt-butylphenol, p-octylphenol, pt-octylphenol, amylphenol, nonylphenol and the like. Examples thereof include linear C _1-20 alkyl-phenol (for example, linear or branched C _1-18 alkyl-phenol, particularly linear or branched C _1-12 alkyl-phenol). These phenols can be used alone or in combination of two or more. Formaldehyde can also be used in the form of a condensate of formaldehyde such as paraformaldehyde. The alkylphenol-formaldehyde resin in which alkylphenols and formaldehyde are co-condensed may be a resol type or a novolac type. Furthermore, if necessary, halogenated (for example, brominated) alkylphenol / formaldehyde resins can be used. The weight average molecular weight of the alkylphenol-formaldehyde resin by gel permeation chromatography may be, for example, 300 to 10000, preferably 500 to 8000, and more preferably about 750 to 5000 in terms of polystyrene.

  As the alkylphenol / formaldehyde resin as the resin crosslinking agent, any resin can be used as long as it is effective for resin crosslinking of the rubber composition, and is not particularly limited, but a compound having a relatively low molecular weight methylol group is preferable. Such compounds (alkylphenol / formaldehyde resins) are, for example, trade names TACKIROL 201 (product of Taoka Chemical Co., Ltd.), HITANOL 2501 (product of Hitachi Chemical Co., Ltd.), SP-1045, SP- 1055 [product of Schenectady Chem.] And the like.

  The usage-amount of a resin crosslinking agent is 5-25 mass parts with respect to 100 mass parts of butyl rubber, Preferably it is 7.5-20 mass parts, More preferably, it is about 10-15 mass parts.

  The usage-amount of the resin crosslinking agent with respect to 100 mass parts of total amounts of a rubber component is 1-10 mass parts, for example, Preferably it is 2-8 mass parts, More preferably, it is about 2-7 mass parts.

  The resin crosslinking agent is advantageously used in combination with a crosslinking aid (or activator). Examples of the crosslinking aid (or activator) include halogen-containing compounds such as inorganic halogen compounds such as tin chloride and ferric chloride, and halogen-containing elastomers such as chloroprene rubber and chlorosulfonated polyethylene. If necessary, halogenated alkylphenol / formaldehyde resins can also be used. In general, it is difficult to increase the hardness of the resin crosslinking agent alone although the crosslinking reaction occurs. Sufficient hardness can be secured by the combined use of an alkylphenol / formaldehyde resin and a crosslinking aid.

  The usage-amount of a crosslinking adjuvant (or activator) is 1-75 mass parts with respect to 100 mass parts of resin crosslinking agents, Preferably it is 5-60 mass parts, More preferably, it is 10-50 mass parts (for example, 20 to 40 parts by mass).

  The rubber composition of the rubber layer 13 is similar to the rubber composition of the compressed rubber layer 6 and the adhesive rubber layer 5 described above, such as a crosslinking accelerator (vulcanization accelerator), a vulcanization retarder, and an enhancer (carbon black, hydrous silica). Etc.), metal oxides (eg zinc oxide, magnesium oxide, calcium oxide, barium oxide, iron oxide, copper oxide, titanium oxide, aluminum oxide etc.), plasticizers or softeners (paraffin oil, process oil) In addition to oils, etc., various additives (for example, anti-aging agents, tackifiers, crosslinking accelerators, accelerating aids, fillers, colorants, stabilizers, flame retardants, antistatic agents) Agent) and the like.

  As the crosslinking accelerator (vulcanization accelerator), a thiuram accelerator, a thiazol accelerator, a sulfenamide accelerator, a bismaleimide accelerator, a guanidine, a urea or a thiourea, as described above. Accelerators, dithiocarbamates and xanthates can be exemplified. These crosslinking accelerators (vulcanization accelerators) can be used alone or in combination of two or more. As the crosslinking accelerator (vulcanization accelerator), thiuram accelerators, sulfenamide accelerators and the like are generally used. The proportion of the vulcanization accelerator is, for example, 0.1 to 15 parts by mass, preferably 0.5 to 10 parts by mass, and more preferably 0.5 to 100 parts by mass of the total amount of the rubber component in terms of solid content. About 5 mass parts may be sufficient.

  An enhancer, particularly carbon black, is useful for maintaining high physical properties such as jacket hardness and modulus. Although the usage-amount of an enhancer (carbon black etc.) is not restrict | limited in particular, For example, 30-100 mass parts with respect to 100 mass parts of total amounts of a rubber component (Butyl rubber and ethylene-alpha-olefin elastomer), Preferably 40-80 It is about a mass part (for example, 45 to 65 mass parts). If the amount of the reinforcing agent (such as carbon black) used is too small, physical properties such as hardness and modulus are lowered, and when a plasticizer is included, the bleed-out of the plasticizer tends to become obvious.

  In addition, the usage-amount of a metal oxide (for example, zinc oxide etc.) is 1-15 mass parts with respect to 100 mass parts of total amounts of a rubber component, Preferably it is 2-10 mass parts, More preferably, it is 3-7. The amount of softener (oils such as process oil) used may be, for example, 0.1 to 10 parts by weight, preferably 0.5 to 100 parts by weight of the total amount of rubber components. -7 mass parts, More preferably, about 1-5 mass parts may be sufficient.

  The jacket 10 is a laminated impregnated body including a rubber layer 13 and a reinforcing material 14 (a cloth material made of at least one fiber material selected from a woven fabric, a knitted fabric, and a non-woven fabric) laminated on the rubber layer. It may be formed. The reinforcing material 14 may be laminated on the surface (inner peripheral surface and / or outer peripheral surface) of the rubber layer 13 or may be embedded in the rubber layer 13.

Examples of the reinforcing material 14 include the fibers exemplified above, such as natural fibers (cotton, etc.), regenerated fibers (rayon, etc.), polyolefin fibers (polyethylene fibers, polypropylene fibers, etc.), acrylic fibers, vinyl alcohol fibers, and polyester fibers. Fiber materials such as fibers (poly C _2-4 alkylene arylate fibers such as polyethylene terephthalate) and polyamide fibers (aliphatic polyamide fibers such as polyamide 6 and polyamide 66, aramid fibers) can be used. These fibers can be used alone or in combination of two or more, and may be a blended fiber. The reinforcing material 14 may be a woven fabric woven in the form of plain weave, twill weave, satin weave, or may be a wide angle canvas or knitted fabric in which the crossing angle between the warp and the weft is about 90 to 120 °. . Furthermore, the reinforcing material 14 may be a non-woven fabric. These reinforcing materials may be formed of long fibers and / or short fibers. Further, the woven fabric may be treated with the resorcin-formalin-latex solution (RFL solution) (immersion treatment or the like) and then friction coated or rubbed with the rubber composition to form a canvas with rubber.

  The jacket of the present invention is formed of a crosslinked body in which the rubber composition is crosslinked. Such a jacket 10 has an unvulcanized rubber layer 13 and a reinforcing material 14 having a predetermined thickness, and a cylindrical drum (molding of the inner peripheral surface) with the reinforcing material 14 interposed between the unvulcanized rubber layers 13. Mold), a method of winding a plurality of layers sequentially, a method of laminating an unvulcanized rubber layer 13 and a reinforcing material 14, and a method of positioning the reinforcing material 14 on the outside, thereby unvulcanized in a predetermined shape in which the reinforcing material 14 is laminated or embedded. A step of forming a rubber layer, a step of attaching flanges 11 to both ends of the molded body as required, and extending the flange 11 outward, and a hollow for forming the outer peripheral surface of the jacket on the outer peripheral portion of the hollow cylindrical molded body Inserting or mounting a cylindrical mold (a mold that covers the unvulcanized jacket to mold and vulcanize the unvulcanized jacket) and vulcanize the mold in a vulcanized can with the mold mounted Process and molded body from cylindrical drum after vulcanization It can be obtained through a process taking out.

  The hollow cylindrical jacket thus obtained is repeatedly used for vulcanization in a state of contact with the outer layer of the cylindrical unvulcanized belt sleeve (with the cylindrical unvulcanized belt sleeve accommodated). Is done. That is, even if the rubber composition of the cylindrical unvulcanized belt sleeve contains a peroxide, the jacket can be prevented from being damaged during the vulcanization process, and the releasability of the vulcanized belt sleeve can be improved. In particular, even when repeatedly used for vulcanization or crosslinking of an unvulcanized belt sleeve over a long period of time, it has high release properties and tear resistance, and can greatly improve the service life (number of uses).

  The present invention is not limited to the vulcanization of the belt sleeve, and the non-vulcanized rubber composition formed of a peroxide vulcanization type (or an unvulcanized rubber layer forming an outer layer) is in contact with the unvulcanized rubber composition. It is useful as a molding member (or molding die) for vulcanizing and molding a vulcanized molded body (or unvulcanized rubber layer) and producing the molded body for a long period of time. For example, the molded member (vulcanized molded member) of the present invention is used as a rubber mold (rubber mold) and can be applied to the production of various rubber mold products, not limited to belt sleeves. Further, the molded member (vulcanized molded member) of the present invention may be hard, or may be soft or flexible like a flexible jacket (bladder). When a flexible jacket (bladder) is used, it can be vulcanized in close contact with the unvulcanized rubber molded body.

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

[Production of jacket]
The rubber composition containing each component in the ratio shown in Table 1 was kneaded with a Banbury mixer, and the kneaded product was rolled to a thickness of 0.5 mm with a calendar roll to obtain a rolled sheet. After a plurality of rolled sheets are stacked to a predetermined thickness, an RFL-treated knitted fabric (made of 75d Woolley polyester) is laminated, and this laminated sheet is wound around a cylindrical drum having an outer diameter of 1,280 mm several times. An unvulcanized molded product having a thickness of 5 mm was formed. A flange formed of the same rubber composition as described above is attached to the molded body and extended outward from both end edges of the molded body, and then a hollow cylindrical tube (jacket) is fitted into the vulcanized can And vulcanized, the vulcanized molded body was extracted from the cylindrical drum to produce a jacket. The vulcanization conditions were 170 ° C. × 20 minutes and a pressure of 1.0 MPa.

  Moreover, about the obtained jacket, while measuring the hardness based on JISK6253 and the tensile strength based on JISK6251, the heat aging test was done based on JISK6257. The results are shown in Table 1.

[Preparation of belt sleeve]
On the molding surface of the mold, an RFL solution (100 parts by mass of a styrene-butadiene-vinylpyridine terpolymer, 14.6 parts by mass of resorcin, 9.2 parts by mass of formalin, 1.5 parts by mass of caustic soda, 262.5 parts of water) 1 ply of cotton canvas treated only by mass part), wrapped with a cord made of polyester fiber rope, 3 plies (laminated sheet with a three-layer structure) formed of compressed rubber layer sheets shown in Table 2 A belt sleeve was prepared by winding a laminate (a laminated sheet having a four-layer structure) in which one ply of the adhesive rubber layer sheet shown in Table 2 was laminated on the three-ply laminated sheet. As the compressed rubber layer sheet, a 1 mm thick sheet obtained by kneading the rubber composition shown in Table 2 with a Banbury mixer and then rolling with a calender roll was used. Further, as the adhesive rubber layer sheet, a 0.5 mm sheet obtained by rolling the rubber composition shown in Table 2 in the same manner was used.

  Then, vulcanization of the belt sleeve (170 ° C. × 40 minutes, pressure 1.0 MPa) was repeated with the various jackets covered, and after 10 times of use, the releasability after 100 times of use and the number of lifetimes were evaluated.

  As the resin crosslinking agent, an alkylphenol / formaldehyde resin (trade name: SP-1055, manufactured by Schenectady Chem) was used. As the vulcanization accelerator, thiuram accelerator (TMTD) and sulfenamide accelerator (CBS) were used. Jacket formability and jacket releasability were evaluated according to the following criteria.

Jacket formability ○: Can be molded smoothly Δ: Can be molded somehow ×: Cannot be molded Jacket releasability ○: Can be smoothly released Δ: Somehow can be released ×: Cannot be released Table 1 shows the results.

  In Table 2, the following components were used as vulcanization accelerators.

Vulcanization accelerator ¹ : Tetramethylthiuram disulfide (TMTD)
Vulcanization accelerator ² : Dipentamethylene thiuram tetrasulfide (DPTT)
Vulcanization accelerator ³ : N-cyclohexylbenzothiazole-2-sulfenamide (CBS)
Organic peroxide ⁴ : Dicumyl peroxide (content 40%)
Crosslinking aid ⁵ : N, N′-m-phenylene dimaleimide As is clear from Table 1, in Examples 1 to 3, when the proportion of the ethylene-α-olefin elastomer increases, the tearing force and the tensile strength increase. The tendency was remarkable also in the physical property after heat aging. Further, even when the jacket was used at least 200 times, abnormalities such as deterioration of the inner peripheral surface of the jacket and deterioration of softening of the outer peripheral surface of the jacket did not occur.

  In Comparative Examples 1 and 2, since the ratio of butyl rubber was high, the releasability was poor and the life was shortened. In Comparative Example 2, the life reached 200 times due to abnormalities such as deterioration of the inner peripheral surface of the jacket peculiar to butyl rubber and softening deterioration of the outer peripheral surface of the jacket, and the releasability was poor immediately after the start of use of the jacket. In Comparative Example 1, the service life was reached after 210 times, and the releasability deteriorated within 100 times.

  In Comparative Examples 3 and 4, the blending ratio of the ethylene-α-olefin elastomer is relatively high, but since the crosslinking agent is not a combined use of sulfur and a thermosetting resin, the service life is less than 100 times and breaks early due to cracking. did.

  In Comparative Example 5, since the ratio of the ethylene-α-olefin elastomer was increased, the rubber composition was not tacky, and it was difficult to form the jacket, so that the jacket could not be manufactured.

  In the present invention, an unvulcanized molded body (such as an unvulcanized belt sleeve) is accommodated in a molded member (a molded member for vulcanization such as a jacket) and vulcanized to obtain a vulcanized molded body (such as a vulcanized belt sleeve). It is useful for repeatedly producing.

DESCRIPTION OF SYMBOLS 1 ... Mold 3 ... Canvas with rubber 4 ... Core wire 5 ... Adhesive rubber layer 6 ... Compression rubber layer 7 ... Belt sleeve 10 ... Jacket 13 ... Rubber layer 14 ... Reinforcement material

Claims (6)

  A molded member for vulcanizing an unvulcanized molded body in contact with the unvulcanized molded body, comprising butyl rubber, an ethylene-α-olefin elastomer, sulfur and a resin cross-linking agent, and butyl rubber and ethylene- A molded member formed of a crosslinked product of a rubber composition in which the ratio to the α-olefin elastomer is the former / the latter = 10/90 to 60/40 (mass ratio).   The molded member according to claim 1, wherein the resin crosslinking agent contains an alkylphenol-formaldehyde resin and a crosslinking aid.   The molded member according to claim 1 or 2, wherein the outer layer of the unvulcanized molded body is a rubber layer formed of a rubber composition containing an organic peroxide.   The molded member according to claim 1, which is a cylindrical jacket for covering and vulcanizing an unvulcanized belt sleeve.   Vulcanizing the unvulcanized molded body in a state where the molded body and the unvulcanized molded body formed of the rubber composition containing the organic peroxide are in contact, and releasing the molded member from the vulcanized molded body Or a method of improving the tearability of a molded member, the molded member comprising butyl rubber, an ethylene-α-olefin elastomer, a crosslinking agent, sulfur and a resin crosslinking agent, and butyl rubber and an ethylene-α-olefin elastomer. And a ratio of the former / the latter = 10/90 to 60/40 (mass ratio) to form a crosslinked product of the rubber composition to improve the releasability or tearability.   A belt obtained by vulcanizing the unvulcanized belt sleeve by covering a non-vulcanized belt sleeve having an unvulcanized rubber layer formed of a rubber composition containing an organic peroxide on an outer layer with a cylindrical jacket. A method for improving the releasability of a jacket from a sleeve or the tearability of a jacket, the jacket comprising butyl rubber, an ethylene-α-olefin elastomer, a crosslinking agent, sulfur and a resin crosslinking agent, A method of improving the releasability or tearability by forming a crosslinked product of a rubber composition in which the ratio of the ethylene-α-olefin elastomer is the former / the latter = 10/90 to 60/40 (mass ratio).

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