JP2007032753A - Transmission belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission belt of high adhesion property to a core wire and high durability. <P>SOLUTION: A V-ribbed belt 31 has an extension portion 35 having a back face composed of a rubber composition including short fiber 34, and a compression portion 36 as a lower layer of the extension portion 35. The core wire 33 is buried in a main body along the belt longitudinal direction, partially kept into contact with the extension portion 35, and kept into contact with the compression portion 36 as concerns the remaining part. The compression portion 35 has a plurality of approximately triangular ribs 37 extending in the belt longitudinal direction, and a bristle burying layer 39 is formed on the rib surface. Here, the extension portion 35 and the compression portion 36 are composed of organic peroxide cross-linked product of a rubber composition obtained by blending ethylene-α-olefin rubber and polyethylene imine at 99.9/0.1-85/15 weight ratio. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power transmission belt used for power transmission.

  In belts used for power transmission, deterioration of rubber in an ozone atmosphere is regarded as a problem, and belts composed of conventional natural rubber, styrene / butadiene rubber, chloroprene rubber, etc., crack early due to this rubber deterioration. Has been pointed out. Further, since rubber containing halogen such as chloroprene leads to generation of dioxins, a belt made of rubber not containing halogen which is an environmental load substance has been demanded in recent years.

Recently, ethylene / α-olefin rubber such as ethylene / propylene rubber (EPM) or ethylene / propylene / diene copolymer rubber (EPDM) has excellent ozone resistance, heat resistance, It is a promising material because it is a cold resistant and relatively inexpensive polymer and meets the requirements for dehalogenation. (For example, see Patent Document 1)
JP-A-6-345948

  However, the adhesiveness of ethylene / α-olefin rubbers including EPM is low, and in particular, it has been a problem with respect to adhesiveness to fiber base materials such as core wires. In addition, the tearing force is low in combination with the poor adhesion, and the use of a peroxide crosslinking system further reduces the tearing force, causing a problem that the core wire tends to pop out during running.

  The present invention solves such problems, and an object of the present invention is to provide a transmission belt having excellent adhesion and high durability.

  The invention according to claim 1 of the present invention is an organic peroxidation of a rubber composition in which at least a part of a main body is blended with ethylene / α-olefin rubber and polyethyleneimine in a weight ratio of 99.9 / 0.1 to 85/15. It is a transmission belt characterized by comprising a physical cross-linked product.

  The invention according to claim 2 of the present application is characterized in that, in the transmission belt according to claim 1, the polyethyleneimine is a branched polymer containing a primary amine, a secondary amine, and a tertiary amine.

  The invention according to claim 3 of the present application is the transmission belt according to claim 1 or 2, wherein the transmission belt is a transmission belt in which a core wire is embedded along the longitudinal direction of the belt, and at least the rubber layer in which the core wire is embedded is provided. It is the organic peroxide-based crosslinked product.

  The invention according to claim 4 of the present application is the transmission belt according to any one of claims 1 to 3, wherein the transmission belt is a friction transmission belt, and at least the rubber layer constituting the friction transmission surface is the organic belt. It is an oxide-based cross-linked product.

  The invention according to claim 5 of the present application is the transmission belt according to any one of claims 1 to 4, wherein the transmission belt is a V-ribbed belt.

  In the invention according to claim 1 of the present application, a part of the main body is made of an organic peroxide-based cross-linked product of a specific rubber composition, whereby a structure excellent in adhesiveness and durability can be obtained. Polyethyleneimine and ethylene / α-olefin rubbers do not contain halogens and therefore do not cause environmental impact.

  In the invention according to claim 2 of the present application, it is considered that a cross-linked product that is well-cross-linked can be obtained by selecting a polyethyleneimine having high reactivity.

  In the invention according to claim 3 of the present application, the rubber layer in which the core wire is embedded is composed of the organic peroxide-based cross-linked product, whereby the adhesive property between the core wire and the main body is good, and the core wire is peeled off or popped out. Can be suppressed.

  In the invention according to claim 4 of the present application, the rubber layer constituting the friction transmission surface is composed of the organic peroxide-based cross-linked product, so that the wettability is improved, and the excellent transmission property and sound resistance even during water injection. It becomes possible to play sex. Moreover, cracks can be suppressed and belt durability can be improved.

  In the invention according to claim 5 of the present application, it is possible to provide a V-ribbed belt that exhibits excellent transmission and sound-proofing properties even during water injection. Moreover, cracks can be suppressed and belt durability can be improved.

  As an example of the transmission belt according to the present invention, a sectional perspective view of a toothed belt 1 is shown in FIG. 1, and a sectional perspective view of a V-ribbed belt 10 is shown in FIG.

  The toothed belt 1 in FIG. 1 has a belt body composed of a plurality of tooth portions 2 and a back portion 4 in which a core wire 3 is embedded along the belt longitudinal direction (arrow in the figure). A tooth cloth 5 is attached to the surface as necessary. Here, the rubber layer in which the core wire 3 is embedded refers to the rubber layer constituting the back portion 4.

  In addition, when the toothed belt 1 is produced by the press-fitting molding method, the tooth portion 2 and the back portion 4 are formed from the same rubber composition sheet, and thus the tooth portion 2 also has the same rubber layer as the back portion 4.

  The V-ribbed belt 10 shown in FIG. 2 includes an extended portion 12 made of a cover canvas 15, an adhesive layer 14 in which a core wire 13 is embedded, and a compression portion 16 below the adhesive layer 14. The compression portion 16 has a plurality of trapezoidal ribs having a substantially triangular cross section extending in the belt longitudinal direction. Here, the rubber layer in which the core wire 13 is embedded refers to a rubber layer constituting the adhesive layer 14. The friction transmission surface is the surface layer of the compression portion 16.

  The core wires 3 and 13 used in the present invention are polyethylene terephthalate (PET) fiber, polyethylene naphthalate (PEN) fiber, polytrimethylene terephthalate (PTT) fiber, polybutylene terephthalate (PBT) fiber, polyparaphenylene benzobisoxazole. A cord composed of (PBO) fiber, polyamide fiber, glass fiber, or aramid fiber can be used. The composition of the glass fiber may be either E glass or S glass (high-strength glass), and is not limited to the thickness of the filament, the number of converging filaments, and the number of strands.

  The core wire is preferably subjected to an adhesive treatment. For example, (1) After impregnating the untreated cord into a tank containing a treatment liquid selected from an epoxy compound and an isocyanate compound, and pre-dip (2) 160 Dry in a drying oven set at a temperature of ~ 200 ° C for 30-600 seconds, (3) then immerse in a tank containing an adhesive solution consisting of RFL, and (4) set the temperature at 210-260 ° C The stretched heat fixing processor can be stretched by −1 to 3% for 30 to 600 seconds to form a stretched cord.

  Examples of the isocyanate compound used in this pretreatment liquid include 4,4′-diphenylmethane diisocyanate, tolylene 2,4-diisocyanate, polymethylene polyphenyl diisocyanate, hexamethylene diisocyanate, and polyaryl polyisocyanate (for example, PAPI as a trade name) ) Etc. This isocyanate compound is used by mixing with an organic solvent such as toluene or methyl ethyl ketone.

  In addition, blocked polyisocyanates in which the isocyanate group of the polyisocyanate is blocked by reacting the isocyanate compound with a blocking agent such as phenols, tertiary alcohols, and secondary alcohols can also be used.

  Examples of the epoxy compound include reaction products of polyhydric alcohols such as ethylene glycol, glycerin and pentaerythritol, polyalkylene glycols such as polyethylene glycol and halogen-containing epoxy compounds such as epichlorohydrin, resorcin, bis (4-hydroxy Phenyl) dimethylmethane, phenol. Formaldehyde resin, resorcin. Reaction products with polyhydric phenols such as formaldehyde resins and halogen-containing epoxy compounds. The epoxy compound is used by mixing with an organic solvent such as toluene or methyl ethyl ketone.

  The RFL treatment liquid is a mixture of resorcin and formaldehyde precondensate with rubber latex. In this case, the molar ratio of resorcin and formaldehyde is preferably 1: 2 to 2: 1 in order to increase the adhesive force. . If the molar ratio is less than 1/2, the three-dimensional reaction of resorcin-formaldehyde resin proceeds too much and gels, while if it exceeds 2/1, the reaction between resorcin and formaldehyde does not progress so much, resulting in a decrease in adhesive strength. To do.

  Examples of rubber latex include styrene / butadiene / vinylpyridine terpolymers, hydrogenated nitrile rubber, chloroprene rubber, and nitrile rubber.

  Further, the solid content mass ratio between the resorcin-formaldehyde initial condensate and the rubber latex is preferably 1: 2 to 1: 8, and if this range is maintained, it is suitable for enhancing the adhesive force. When the above ratio is less than 1/2, the resin content of resorcin-formaldehyde increases, the RFL film becomes hard and dynamic adhesion deteriorates. On the other hand, when the ratio exceeds 1/8, the resin content of resorcin-formaldehyde Therefore, the RFL film becomes soft and the adhesive strength decreases.

  Further, a vulcanization accelerator or a vulcanizing agent may be added to the RFL liquid, and the vulcanization accelerator to be added is a sulfur-containing vulcanization accelerator. Specifically, 2-mercaptobenzothiazole (M ) And salts thereof (for example, zinc salts, sodium salts, cyclohexylamine salts, etc.) thiazoles such as dibenzothiazyl disulfide (DM), sulfenamides such as N-cyclohexyl-2-benzothiazylsulfenamide (CZ) , Thiurams such as tetramethylthiuram monosulfide (TS), tetramethylthiuram disulfide (TT), dipentamethylenethiuram tetrasulfide (TRA), sodium di-n-butyldithiocarbamate (TP), zinc dimethyldithiocarbamate ( PZ) Dithiocarbamine such as zinc diethyldimethyldithiocarbamate (EZ) There are salts and the like.

  Examples of the vulcanizing agent include sulfur, metal oxides (zinc oxide, magnesium oxide, lead oxide), peroxides, and the like, which are used in combination with the above vulcanization accelerator.

  As the tooth cloth 5 that covers the tooth surface of the toothed belt 1, a canvas made of a plain woven fabric, a twill woven fabric, a satin woven fabric, or the like is used. As the wefts arranged in the belt longitudinal direction of these woven fabrics, for example, multifilament yarns obtained by converging filament base yarns of para-aramid fibers of 0.3 to 1.2 deniers are 20 to 80 of the total amount of wefts in the belt longitudinal direction. Those containing wt% are preferred.

  That is, the weft is a yarn including a multi-filament yarn of para-aramid fiber, and the multi-filament yarn of the para-aramid fiber can include a yarn made of a meta-aramid fiber. The specific configuration of the weft is a combination of three types of yarns, a multi-filament yarn of para-aramid fiber, a spun yarn made of meta-aramid fiber, and a urethane elastic yarn.

  Other specific wefts are composed of three types of yarns: multi-filament yarns of para-aramid fibers, aliphatic fiber yarns (6 nylon, 66 nylon, polyester, polyvinyl alcohol, etc.), and urethane elastic yarns. It may be twisted.

  The warp of the tooth cloth 5 is composed of filament yarns of aramid fibers made of para-type aramid fibers and meta-type aramid fibers, polyamide yarns such as 6 nylon, 6.6 nylon and 12 nylon, and filament yarns of polyvinyl alcohol and polyester. Preferably, if the filament yarn of aramid fiber is a multifilament yarn in which the filament yarn of para-aramid fiber is converged for the weft yarn 5, the rigidity balance is achieved and the tooth cloth becomes uniform in thickness.

  However, the materials of the warp and weft are not limited to these, and other forms include cords, non-woven fabrics, knitted fabrics and the like, and are not particularly limited. In addition, it is desirable that the tooth cloth is adhered with an adhesive rubber by soaking, spreading, coating, or the like.

  The cover canvas 15 used for the V-ribbed belt 10 is a fiber base selected from woven fabric, knitted fabric, non-woven fabric, and the like. Known and publicly used fiber materials can be used. For example, natural fibers such as cotton and hemp, inorganic fibers such as metal fibers and glass fibers, and polyamide, polyester, polyethylene, polyurethane, polystyrene, and polyfluoroethylene. , Organic fibers such as polyacryl, polyvinyl alcohol, wholly aromatic polyester, and aramid. In the case of a woven fabric, these yarns are woven by plain weaving, twill weaving, satin weaving or the like.

  The cover canvas 15 is preferably immersed in a resorcin-formaldehyde-latex liquid (RFL liquid) according to a known technique. Further, after being immersed in the RFL solution, friction can be performed by rubbing the unvulcanized rubber into the cover canvas 15 or immersion can be performed in a soaking solution in which the rubber is dissolved in a solvent. The RFL solution may be appropriately mixed with a carbon black solution to blacken the treatment, or a known surfactant may be added in an amount of 0.1 to 5.0% by mass.

  In the present invention, it is essential that at least a part of the belt body is composed of an organic peroxide-based crosslinked product of the following rubber composition. That is, at least a part of the belt body is composed of an organic peroxide-based cross-linked product of a rubber composition in which ethylene / α-olefin rubber and polyethyleneimine are blended in a weight ratio of 99.9 / 0.1 to 85/15. The A rubber composition containing a specific proportion of ethylene / α-olefin rubber and polyethyleneimine is cross-linked in the presence of an organic peroxide, so that it can be used well with ethylene / α-olefin rubber due to the high reactivity of polyethyleneimine. It is considered that a crosslinked organic peroxide-based crosslinked product is obtained.

  When the ratio of polyethyleneimine is less than the above range, no improvement in adhesion can be seen and belt durability cannot be improved. In addition, since water wettability is not improved, improvement in transmission and sound resistance during water injection is not observed. On the other hand, when the ratio of polyethyleneimine exceeds the above range, there is a problem that the hardness and modulus are extremely lowered and the belt life is shortened.

  Examples of the ethylene / α-olefin rubber include a copolymer of ethylene and α-olefin (propylene, butene, hexene, or octene), or a copolymer of ethylene, the α-olefin, and the nonconjugated diene. Specifically, it refers to rubber such as EPM and EPDM. Examples of the diene component include non-conjugated dienes having 5 to 15 carbon atoms such as ethylidene norbornene, dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, and methylene norbornene.

  Polyethyleneimine is, for example, a linear polymer such as polyethyleneimine obtained by polycondensation reaction of ethylene dichloride and ethylenediamine, polyethyleneimine obtained by heat-opening 2-oxazoline, or ring opening of ethyleneimine. Examples include linear polymer such as polymer of polyethyleneimine obtained by polymerization, and branched polymer such as branched polymer containing primary amine, secondary amine, and tertiary amine. be able to. Of these, branched polymers containing primary amines, secondary amines, and tertiary amines are desirable because of their high reactivity. The ratio of primary amine: secondary amine: tertiary amine is not limited, but it is assumed that, for example, primary amine: secondary amine: tertiary amine = 1: 2: 1 amine ratio. There is "Epomin" made by Nippon Shokubai. Those having a number average molecular weight of 300 to 100,000 are preferably used.

  The rubber composition is blended with an organic peroxide as a crosslinking agent. Examples of the organic peroxide include dicumyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, benzoyl peroxide, 1,3-bis (t-butylperoxyisopropyl) benzene, 2,5 -Dimethyl-2,5-di (t-butylperoxy) hexyne-3,2,5-dimethyl-2,5- (benzoylperoxy) hexane, 2,5-dimethyl-2,5-mono (t- Butyl peroxy) hexane and the like. This organic peroxide is preferably used alone or as a mixture in the range of 0.5 to 8 parts by weight with respect to 100 parts by weight of the polymer component.

  Further, the rubber composition may contain 0.5 to 13 parts by weight of N, N'-m-phenylene dimaleimide and / or quinonedioxime with respect to 100 parts by weight of the polymer component. N, N′-m-phenylene dimaleimide and / or quinonedioxime acts as a co-crosslinking agent, and if less than 0.5 part by weight, the effect of addition is not significant, and if it exceeds 13 parts by weight, tearing force and adhesion The force drops sharply. At this time, when N, N′-m-phenylene dimaleimide is selected as the co-crosslinking agent, the cross-linking density is high, the wear resistance is high, and the difference in transmission performance between water injection and drying is small. is there. Further, when quinone dioximes are selected, there is a feature that the adhesiveness with the fiber base material is excellent.

  Examples of quinone dioximes include p-benzoquinone dioxime, p, p'-dibenzoquinone dioxime, and tetrachlorobenzoquinone poly (P-dinitrobenzoquinone). In view of adhesiveness and crosslink density, benzoquinone dioximes such as p-benzoquinone dioxime and p, p'-dibenzoquinone dioxime are preferred.

  And other than that, normal fibers such as short fiber, carbon black, reinforcing agents such as silica, fillers such as calcium carbonate and talc, plasticizers, stabilizers, processing aids, colorants, etc. Those used in rubber compounds are used.

  Next, a transmission belt in which a part of the transmission belt main body is formed of the above-described crosslinked material will be described with a specific example.

  (1) The rubber layer in which at least the core wires 3 and 13 of the transmission belt main body are embedded can be constituted by the crosslinked product. In addition, when a core wire is in contact with a plurality of rubber layers, it means that at least one rubber layer is composed of the crosslinked product. Thereby, the power transmission belt excellent in durability while being excellent in adhesiveness with the core wires 3 and 13 is obtained.

  In the toothed belt 1, the rubber layer in which the core wire 3 is embedded refers to the rubber layer constituting the back portion 4. In addition, when the toothed belt 1 is produced by the press-fitting molding method, the tooth portion 2 and the back portion 4 are formed from the same rubber composition sheet, and thus the tooth portion 2 also has the same rubber layer as the back portion 4.

  In the V-ribbed belt 10, the rubber layer in which the core wire 13 is embedded refers to the rubber layer constituting the adhesive layer 14.

  In addition, since the rubber composition is excellent in adhesiveness to fibers, the rubber layer that is in contact with the fiber member other than the core wire is also composed of the rubber composition, so that the belt main body and the fiber member are well bonded. Is obtained. For example, in the toothed belt 1, if the rubber layer in contact with the tooth cloth 5, that is, the tooth portion 2 is formed of the rubber composition, peeling of the tooth cloth 5 can be suppressed.

  (2) At least the friction transmission surface of the friction transmission belt main body can be composed of the cross-linked product. In addition, when there are a plurality of friction transmission surfaces, it means that at least one friction transmission surface is composed of the crosslinked product. Thereby, it is possible to achieve excellent transmission and quietness even during water injection.

  In the V-ribbed belt 10 that is a friction transmission belt, the friction transmission surface is a surface layer of the compression portion 16.

  Generally, the SP value of polyethyleneimine is higher than the SP value of ethylene / α-olefin rubber. Therefore, if the friction transmission surface, that is, the surface layer of the compression portion 16 is composed of the cross-linked product, water wettability is higher than conventional belts composed only of ethylene / α-olefin rubber, and slip and sound generation during water injection are suppressed. There is an effect to. The SP value is a solubility parameter defined by the square root of the cohesive energy density CED (the amount of energy required to evaporate 1 cc).

  In addition, although it is mentioned as an essential condition of the present invention that at least a part of the transmission belt body is composed of the crosslinked product, it is needless to say that all the rubber layers constituting the transmission belt body are composed of the crosslinked product. Is also possible.

  When a rubber composition other than the above rubber composition is used for the belt body, for example, a blend rubber obtained by mixing ethylene / α-olefin rubber alone or a partner rubber made of other kinds of rubber as a rubber component can be used. As the other rubber blended with ethylene / α-olefin rubber, butadiene rubber (BR), styrene / butadiene rubber (SBR), nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), chloroprene rubber (CR), Mention may be made of at least one rubber of butyl rubber (IIR) and natural rubber (NR).

  The compression part 16 of the V-ribbed belt 10 is mixed with short fibers made of polyamide, polyester, cotton, aramid, PBO or the like to improve the side pressure resistance of the compression part 16 and to be a surface in contact with the pulley. The short fibers can be protruded from the surface to reduce the friction coefficient of the compression portion, thereby reducing noise during belt running. The aramid fiber has an aromatic ring in the molecular structure, and examples thereof include trade names Conex, Nomex, Kevlar, Technora and Twaron.

  The short fiber has a fiber length of 1 to 20 mm, and the addition amount is preferably 5 to 50 parts by weight with respect to 100 parts by weight of rubber. If the amount of short fibers added is less than 1 part by weight, the rubber of the compression part 16 tends to stick and wear, and if it exceeds 40 parts by weight, the short fibers are uniformly in the rubber. Difficult to disperse. In order to improve the adhesion of the short fibers to the rubber of the compression part 16, it is preferable that the short fibers are subjected to an adhesion treatment with a treatment liquid containing an epoxy compound, an isocyanate compound or the like.

  The V-ribbed belt is not limited to the configuration shown in FIG. 2, and for example, a V-ribbed belt in which no adhesive layer is disposed, a V-ribbed belt in which rubber is exposed without attaching a cover canvas on the back surface, and the like are also within the technical scope of the present invention. Belongs. Hereinafter, these embodiments will be described with reference to the drawings.

  The V-ribbed belt 21 shown in FIG. 3 has a stretched portion 25 formed of a rubber composition with a back surface 28 provided with a flocking layer 24, and an adhesive layer 22 disposed below the stretched portion 25, and further compressed under the lower layer. The portion 26 is arranged. The core wire 23 is embedded in the main body along the longitudinal direction of the belt, and a part thereof is in contact with the extending portion 25 and the remaining portion is in contact with the adhesive layer 22. The compression portion 26 is provided with a plurality of ribs 27 having a substantially triangular cross section extending in the belt longitudinal direction. Here, the short fiber contained in the compression part 26 exhibits the flow state along the rib shape, and the short fiber near the surface is oriented along the rib shape.

  A V-ribbed belt 31 shown in FIG. 4 has a configuration in which a back surface 38 is formed of a stretch portion 35 formed of a rubber composition containing short fibers 34, and a compression portion 36 is disposed below the stretch portion 35. The core wire 33 is embedded in the main body along the longitudinal direction of the belt, and a part thereof is in contact with the extension part 35 and the remaining part is in contact with the compression part 36. The compression section 35 is provided with a plurality of ribs 37 having a substantially triangular cross section extending in the belt longitudinal direction, and a flocking layer 39 is provided on the rib surface. Here, the short fibers contained in the extending portion 25 are oriented in a random direction.

  Here, FIG. 4 shows a configuration in which the extending portion 35 is not made of a cover canvas but is made of a rubber composition containing short fibers. A concavo-convex pattern can be provided on the surface. Examples of the concavo-convex pattern include a knitted fabric pattern, a woven fabric pattern, a suede woven fabric pattern, and the like, and most preferably a woven fabric pattern. Moreover, as short fiber, polyester, aramid, nylon, cotton, etc. can be mix | blended as desired, It is desirable to orientate in a belt width direction. As the rubber composition and the core wire constituting the stretched part, the compressed part and the adhesive layer, the same ones as described above can be used.

  In FIG. 4, the short fibers contained in the stretched portion 35 are oriented in a random direction, but may be oriented in one direction, such as in the belt width direction. In addition, when oriented in a random direction, there is a feature that the generation of cracks and cracks from multiple directions can be suppressed. At this time, if a short fiber (for example, a milled fiber) having a bent portion is selected as the short fiber, more It has a feature that it can withstand the force acting from the direction.

  4, the core wire 33 is embedded in the belt main body at the boundary region between the extending portion 35 and the compressing portion 36. At this time, in consideration of the adhesiveness between the core wire 33 and the belt body, it is desirable that the compression portion 36 is made of a rubber composition not containing short fibers.

  In addition, in FIG. 3, although the extending | stretching part 25 is set as the structure which provided the flocked layer 24 on the rubber composition surface which does not contain a short fiber, it is set as the structure which provided the flocked layer on the rubber composition surface containing a short fiber. It is also possible.

  In FIG. 3, the short fibers contained in the compression part 26 are in a flow state along the rib shape, but the short fibers may be oriented in the width direction.

  When the V-ribbed belt performs rear transmission, the surface of the extension portion also becomes a friction transmission surface.

  Next, a method for manufacturing these V-ribbed belts will be described. Although it does not limit as a manufacturing method, For example, there exist the following methods.

  As a first method, first, a member constituting an extension portion and an adhesive rubber sheet constituting an adhesive layer are wound around a circumferential surface of a cylindrical molding drum, and then a cord made of a cord is spirally wound thereon. Then, a compressed rubber sheet constituting the compression portion is wound in order to form an unvulcanized sleeve, and then vulcanized to obtain a vulcanized sleeve. Next, the vulcanization sleeve is hung on a driving roll and a driven roll and travels under a predetermined tension. Further, the rotated grinding wheel is moved so as to abut on the traveling vulcanization sleeve to compress the sleeve. A surface of 3 to 100 grooves is polished on the surface at a time to form a friction transmission surface. The sleeve thus obtained is removed from the driving roll and the driven roll, the sleeve is hung on the other driving roll and the driven roll, traveled, cut into a predetermined width by a cutter, and finished into individual V-ribbed belts. .

  As a second method, after winding a compression rubber sheet constituting a compression part and an adhesive rubber sheet constituting an adhesive layer around a cylindrical molding drum provided with rib markings on the peripheral surface, spinning a core wire, An unvulcanized sleeve is arranged by winding a member constituting the extension portion. Thereafter, the unvulcanized sleeve is vulcanized while being pressed against the molding drum, whereby a rib is formed on the compression portion. The obtained vulcanized sleeve is formed with ribs. The rib surface is polished if necessary, and cut into a predetermined width to obtain individual V-ribbed belts.

  As a third method, after winding a member constituting an extension portion and an adhesive rubber sheet constituting an adhesive layer on a flexible jacket mounted on a cylindrical molding drum, spinning a core wire thereon Further, the compressed rubber sheets constituting the compression part are sequentially wound endlessly to form an unvulcanized sleeve. Then, the flexible jacket is expanded, and the unvulcanized sleeve is pressed against an outer mold having an inscription corresponding to the rib portion, and vulcanized. The obtained vulcanized sleeve is formed with ribs. The rib surface is polished if necessary, and cut into a predetermined width to obtain individual V-ribbed belts.

  As a fourth method, after forming the first unvulcanized sleeve in which the compressed rubber sheet constituting the compression portion is arranged on the flexible jacket mounted on the cylindrical molding drum, the flexible jacket is used. The first unvulcanized sleeve is expanded and pressed against an outer mold having an inscription corresponding to the rib portion to produce a preform having the rib portion. Then, the inner mold is separated from the outer mold to which the preformed body is in close contact, and then the member constituting the extension part and the adhesive rubber sheet constituting the adhesive layer are arranged on the inner mold, and the core wire is spun. A second unvulcanized sleeve is formed. Then, the flexible jacket is expanded, and the second unvulcanized sleeve is pressed from the inner peripheral side to the outer mold to which the preform is in close contact, and is vulcanized integrally with the preform. Ribs are formed on the obtained vulcanized belt sleeve, but the rib surface is polished if necessary and cut into a predetermined width to obtain individual V-ribbed belts.

  When the compression part of the V-ribbed belt is composed of two layers, a surface layer and an inner layer, a compression rubber sheet having a two-layer structure of the surface layer and the inner layer is wound, or the compression rubber sheet for the surface layer and the compression rubber sheet for the inner layer are sequentially wound It is necessary to form an unvulcanized sleeve in which a compression portion having a two-layer structure of a surface layer and an inner layer is arranged by winding or the like. At this time, since the rib is formed by polishing in the first method, it is considered that the surface layer exists on the rib crest of the obtained V-ribbed belt, but the inner layer is exposed on the rib side surface and the rib bottom. Therefore, it is desirable that the V-ribbed belt composed of two layers of the surface layer and the inner layer is manufactured by the second method, the third method, or the fourth method.

  Further, the V-ribbed belt having no adhesive layer as shown in FIG. 4 can be obtained by manufacturing without the adhesive rubber sheet in the above method. Further, as shown in FIG. 3, the V-ribbed belt in which the short fibers contained in the compression portion 26 are in a flow state along the rib shape is manufactured by, for example, the second method, the third method, or the fourth method. Can be obtained. And the V-ribbed belt in which the short fibers contained in the compression part are oriented in the width direction can be obtained by, for example, the first method.

  The power transmission belt is not limited to the above-described toothed belt and V-ribbed belt, and a V belt, a flat belt, and the like also belong to the technical scope of the present invention.

  Hereinafter, a description will be given with specific examples.

  The physical properties of vulcanized rubber obtained by press vulcanizing the rubber composition shown in Table 1 for 30 minutes at 165 ° C. were measured. The hardness (JIS-A) of the obtained vulcanized rubber is set to JIS K6253, the elongation EB during cutting (perpendicular to the orientation direction of the short fibers) is set to JIS K6251 and the strength TB (MPa) when cutting is set. It measured according to JIS K6251. In addition, the polyester fiber cords subjected to adhesion treatment are arranged in a 25 mm width on a 4 mm thick rubber sheet having the composition shown in Table 1, and vulcanized at 165 ° C. for 30 minutes under a pressure of 2.0 MPa with a press plate. A sample for an adhesion test was prepared. The adhesion strength of each sample was measured according to JIS K6256. These results are shown in Table 2.

  Next, a V-ribbed belt was produced using the rubber composition shown in Table 1. In the V-ribbed belt manufactured in this example, a stretched portion is formed of a rubber composition in which short fibers are oriented in the belt width direction, and a compression portion in which short fibers are oriented in the belt width direction is provided below the stretched portion. And the core wire which consists of a rope of a polyester fiber was embed | buried between the expansion | extension part and the compression part. Note that the compression portion is formed with three ribs in the longitudinal direction of the belt. Here, the stretched portion and the compressed portion were prepared from the rubber composition shown in Table 1, kneaded with a Banbury mixer, and then rolled with a calendar roll.

  The manufacturing method of the belt is a known method. First, an unvulcanized stretched rubber sheet is wound around a flat cylindrical mold, and then a polyester core wire is spun. Next, after winding an unvulcanized compressed rubber sheet, a vulcanization jacket is extrapolated on the compressed rubber sheet. Next, the molding mold is placed in a vulcanizing can and vulcanized. Then, the cylindrical vulcanizing sleeve is taken out of the mold, the compressed portion of the sleeve is molded into a rib by a grinder, and the molded body is cut into individual belts. It consists of a process.

The V-ribbed belt thus obtained was subjected to a heat resistance flexibility test.
The running test machine used for the evaluation of the heat-resistant bending test includes a driving pulley (diameter 60 mm), an idler pulley (diameter 50 mm), a driven pulley (diameter 50 mm), a tension pulley (diameter 50 mm), and an idler pulley (diameter 50 mm). Are arranged in order. A V-ribbed belt is hung on each pulley of the test machine, the wrapping angle of the belt around the idler pulley is 90 °, the ambient temperature is 130 ° C, the rotational speed of the drive pulley is 3300 rpm, and the belt tension is 800 N / rib. After applying a load to the driving pulley, the time until six cracks reaching the core wire after running was examined. The test was terminated after 400 hours. Table 2 shows the results of failure phenomenon and travel time.

  As a result, it can be seen that the example is a V-ribbed belt having excellent durability between the core wire and the main body and high durability. On the other hand, in Comparative Example 1 in which polyethyleneimine was excessively blended, the hardness was extremely lowered and the elongation at break was extremely increased, and it was confirmed that many cracks were generated in the running test. Further, in Comparative Example 2 in which EPDM alone was used as the rubber component, it was confirmed that the core wire was peeled off from the belt body, although the adhesion was poor and traveling was possible until the end time. Further, Comparative Example 3 composed of chloroprene rubber had extremely low adhesiveness with the core wire, and it was impossible in practical use.

  The transmission belt according to the present invention can be attached to a drive device for automobiles or general industries.

It is a section perspective view of a toothed belt which is a power transmission belt concerning the present invention. It is a cross-sectional perspective view of the V-ribbed belt which is a power transmission belt which concerns on this invention. It is sectional drawing of another V-ribbed belt which is a power transmission belt which concerns on this invention. It is sectional drawing of another V-ribbed belt which is a transmission belt which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Toothed belt 2 Tooth part 3 Core wire 4 Back part 5 Tooth cloth 10 V-ribbed belt 12 Extension part 13 Core wire 14 Adhesive layer 15 Cover canvas 16 Compression part

Claims (5)

  At least a part of the main body is composed of an organic peroxide-based crosslinked product of a rubber composition in which ethylene / α-olefin rubber and polyethyleneimine are blended at a weight ratio of 99.9 / 0.1 to 85/15. A transmission belt characterized by   The power transmission belt according to claim 1, wherein the polyethyleneimine is a branched polymer containing a primary amine, a secondary amine, and a tertiary amine.   The power transmission belt according to claim 1 or 2, wherein the power transmission belt is a power transmission belt having a core wire embedded in the longitudinal direction of the belt, and at least a rubber layer in which the core wire is embedded is the organic peroxide-based crosslinked product.   The transmission belt according to any one of claims 1 to 3, wherein the transmission belt is a friction transmission belt, and at least a rubber layer constituting the friction transmission surface is the organic peroxide-based crosslinked product. The power transmission belt according to any one of claims 1 to 4, wherein the power transmission belt is a V-ribbed belt.

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