JP2009275781A - Driving belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain strong adhesion between a belt body and a core wire without deteriorating durability. <P>SOLUTION: A driving belt B keeps a core wire 16 embedded via adhesion layer 17 in the rubber belt body 10. The adhesion layer 17 has a thin layer 18 provided such as to surround the core wire and containing polybutadiene formed by 1,2-addition of 20 to 90 mol% of 1,3-butadiene monomer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a transmission belt in which a core wire is embedded in a rubber belt main body through an adhesive layer.

  In power transmission belts used for automobiles and the like, a core wire is embedded in a rubber belt body, and a reinforcing cloth for covering the surface is provided in some cases. Therefore, a technique for bonding a rubber material and a fiber material is indispensable.

  For example, Patent Documents 1 to 4 disclose that the core wire is bonded with a resin adhesive containing maleic acid-modified or maleic anhydride-modified liquid polybutadiene.

Patent Documents 5 to 9 disclose that a maleic acid-modified liquid polybutadiene is contained in the rubber composition constituting the belt body in order to improve the adhesive force between the belt body and the core wire.
JP 2007-154382 A JP 2006-300026 A JP 2005-519182 A JP 2005-511904 A JP 2007-40363 A JP 2005-315415 A JP 2006-161926 A JP 2006-22917 A JP 2001-173728 A

  In recent years, transmission belts are often used under conditions of higher temperature and higher load than before, and accordingly, shear strain and shear stress generated between the core wire and the belt main body are also increased. A problem that the core wire peels off from the belt body and jumps out becomes a problem.

  An object of the present invention is to obtain high adhesion between a belt body and a core wire without impairing durability.

The present invention is a transmission belt in which a core wire is embedded through an adhesive layer in a rubber belt body,
The adhesive layer has a thin layer containing 1,2-polybutadiene which is 1,2-added polybutadiene having 20 to 90 mol% of 1,3-butadiene monomer provided so as to surround the core wire.

The present invention is a transmission belt in which a core wire is embedded through an adhesive layer in a rubber belt body,
The core wire is subjected to a treatment of dipping in a rubber paste containing 1,2-polybutadiene, which is a polybutadiene in which 20 to 90 mol% of 1,3-butadiene monomer is 1,2-added, and then dried.

  According to the present invention, high adhesion between the belt body and the core wire can be obtained without impairing durability.

  Hereinafter, embodiments will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a V-ribbed belt B according to the first embodiment. The V-ribbed belt B is used, for example, in an accessory drive belt transmission device provided in an engine room of an automobile, and has a belt circumferential length of 700 to 3000 mm, a belt width of 10 to 36 mm, and a belt thickness of 4. 0.0 to 5.0 mm.

  In the V-ribbed belt B according to the first embodiment, a core wire 16 is embedded in the rubber V-ribbed belt main body 10 via an adhesive layer 17 so as to form a spiral having a pitch in the belt width direction. The adhesive layer 17 has a thin layer 18 containing 1,2-polybutadiene provided so as to surround the core wire 16. Here, in the present application, “1,2-polybutadiene” refers to polybutadiene in which 20 to 90 mol% of 1,3-butadiene monomer is 1,2-added. The molar fraction of 1,2-added 1,3-butadiene monomer in 1,2-polybutadiene is referred to as “1,2-vinyl content”.

  The V-ribbed belt main body 10 has a plurality of Vs constituting a belt-shaped portion having a horizontally long rectangular cross section and a belt contacting portion on the inner side of the belt. The rib 13 has a portion provided so as to hang down. The plurality of V ribs 13 are each formed in a ridge having a substantially inverted triangular cross section extending in the belt length direction, and arranged in parallel in the belt width direction. Each V rib 13 is formed, for example, with a rib height of 2.0 to 3.0 mm and a width between base ends of 1.0 to 3.6 mm. The number of ribs is, for example, 3 to 6 (in FIG. 1, the number of ribs is 6). The V-ribbed belt body 10 is formed of a rubber composition in which various compounding agents are blended with a rubber component.

  Examples of the rubber component of the rubber composition constituting the V-ribbed belt body 10 include ethylene-α-olefin elastomer rubbers such as ethylene / propylene rubber (EPR) and ethylene propylene diene monomer rubber (EPDM), chloroprene rubber (CR), Examples include chlorosulfonated polyethylene rubber (CSM) and hydrogenated acrylonitrile rubber (H-NBR). Of these, ethylene-α-olefin elastomer rubber is preferred from the viewpoint of environmental considerations and performance such as wear resistance and crack resistance. The rubber component may be composed of a single species or a blend of a plurality of species. However, the rubber component does not contain 1,2-polybutadiene.

  As a compounding agent of the rubber composition constituting the V-ribbed belt main body 10, for example, a crosslinking agent (for example, sulfur, organic peroxide), an anti-aging agent, a processing aid, a plasticizer, carbon black (iodine adsorption amount is 40 mg) Reinforcing materials such as carbon black having a large particle size of / g or less), fillers, ultrahigh molecular weight polyethylene particles (weight average molecular weight of 1 million or more), short fibers 14 and the like.

  Although the rubber composition constituting the V-ribbed belt main body 10 may contain 30 parts by mass or less, more preferably 10 parts by mass or less of 1,2-polybutadiene with respect to 100 parts by mass of the rubber component, Most preferably, it is 5 parts by mass or less and is substantially free of 1,2-polybutadiene or no 1,2-polybutadiene.

  The rubber composition forming the V-ribbed belt main body 10 is obtained by crosslinking an uncrosslinked rubber composition obtained by blending a rubber component with a compounding agent and kneading the mixture with a crosslinking agent.

  As described above, the short fiber 14 may be blended in the rubber composition forming the V-ribbed belt main body 10, but the short fiber 14 is preferably provided so as to be oriented in the belt width direction. . A part of the short fibers 14 is exposed on the pulley contact surface, that is, the surface of the V rib 13, but it is preferable that the short fibers 14 exposed on the surface of the V rib 13 protrude from the surface of the V rib 13. In addition, the structure by which the short fiber was planted on the V rib 13 surface may be sufficient.

  Examples of the short fibers 14 include nylon short fibers, aramid short fibers, polyester short fibers, vinylon short fibers, and cotton short fibers.

  The short fiber 14 is obtained by, for example, cutting a long fiber that has been subjected to an adhesive treatment to be heated after being immersed in a resorcin / formalin / latex aqueous solution (hereinafter referred to as “RFL aqueous solution”) into a predetermined length along the length direction. Manufactured. The short fiber 14 has a length of 0.2 to 5.0 mm and a fiber diameter of 10 to 50 μm, for example.

  The short fiber 14 has a content of, for example, 5 to 25 parts by mass with respect to 100 parts by mass of the rubber component.

  The core wire 16 is composed of, for example, a twisted yarn, a braided string, or the like, and has a thickness of 2000 to 11000 dtex and a core wire diameter of 0.60 to 1.25 mm.

  Examples of the fiber material constituting the core 16 include polyester fiber (PET), aromatic polyamide fiber (aramid fiber), nylon fiber, glass fiber, carbon fiber, polyketone fiber, polyethylene naphthalate fiber (PEN), and vinylon fiber. , PBO fiber, cotton yarn and the like.

  The core wire 16 is subjected to an adhesive treatment before molding in order to provide adhesion to the V-ribbed belt body 10.

  Examples of the bonding process include a first process (ground process), a second process (RFL process), and a third process (rubber paste process). By this adhesion treatment, an adhesive layer 17 is provided so as to surround the core wire 16 as shown in FIG. The layer thickness of the adhesive layer 17 is, for example, 1 to 10 μm. The cord 16 has been subjected to at least a third treatment, so that the adhesive layer 17 has a thin layer 18 containing 1,2-polybutadiene. The layer thickness of the thin layer 18 is preferably 0.1 to 200 μm, for example. Thus, since the adhesive layer 17 has the thin layer 18 containing 1,2-polybutadiene, high adhesiveness between the V-ribbed belt main body 10 and the core wire 16 can be obtained without impairing durability. The third treatment is preferably performed on the core wire 16 that has been subjected to the first treatment and / or the second treatment. In this case, the ground and / or the RFL between the core wire 16 and the thin layer 18 is preferable. There will be intervening layers.

  Hereinafter, the first to third processes will be described.

-First treatment (ground treatment)-
The first process is a process of heating the core wire 16 after immersing it in the base treatment liquid.

  Examples of the base treatment liquid include a solution in which a base treatment agent is dissolved in a solvent.

  Examples of the base treatment agent include an epoxy compound, an isocyanate compound, and a blocked isocyanate compound. The ground treatment agent may be composed of a single species, or may be composed of a mixture of a plurality of species.

  Examples of the solvent include water and organic solvents such as toluene and methyl ethyl ketone (MEK).

  In addition, the surface treatment liquid may contain a surfactant, a component for improving adhesiveness, and the like.

  The solid content concentration of the base treatment liquid varies depending on the type of the base treatment agent, but is, for example, 3 to 25% by mass. The viscosity of the ground treatment liquid is, for example, 0.5 to 50 cP.

  The immersion time in the ground treatment liquid in the first treatment is, for example, 0.5 to 5 seconds. The heating temperature in the first treatment is, for example, 180 to 270 ° C., although it varies depending on the type of the base treatment agent. The heating time in the first treatment varies depending on the type of the base treatment agent, but is, for example, 30 seconds to 2 minutes. The tension at the time of heating in the first treatment varies depending on the type of fiber material constituting the core wire 16, but is, for example, 0.002 to 0.030 N / dtex.

  The solid content of the ground treatment agent with respect to the core wire 16 is, for example, 1.0 to 7.0% by mass with respect to the dry mass of the core wire 16.

  This first treatment may be performed a single time or may be repeated a plurality of times.

-Second process (RFL process)-
The second treatment is a treatment in which the unbonded core wire 16 or the core wire 16 subjected to the first treatment is immersed in the RFL aqueous solution and then heated.

  The RFL aqueous solution is a mixed aqueous solution of an initial condensate of resorcin (R) and formalin (F) and latex (L).

  Examples of the latex (L) include styrene / butadiene / vinylpyridine terpolymer rubber latex, chlorosulfonated polyethylene rubber latex, nitrile rubber latex, hydrogenated acrylonitrile rubber latex, epichlorohydrin rubber latex, styrene butadiene rubber latex, chloroprene. Examples thereof include rubber latex, chlorinated butadiene rubber latex, olefin-vinyl ester copolymer rubber latex, and natural rubber latex. Latex (L) may be composed of a single species or may be composed of a mixture of a plurality of species.

  R / L (molar ratio) is, for example, 1/1 to 1/4. RF / L (mass ratio) is, for example, 1 / 1.5 to 1/20.

  In addition, the RFL aqueous solution may contain a surfactant, ZnO, blocked isocyanate, and the like.

  The solid content concentration of the RFL aqueous solution is, for example, 3 to 25% by mass. The viscosity of the RFL aqueous solution is, for example, 1 to 200 cP.

  The immersion time in the RFL aqueous solution in the second treatment is, for example, 1 to 25 seconds. The heating temperature in the second treatment is, for example, 150 to 280 ° C. The heating time in the second treatment is, for example, 30 seconds to 2 minutes. The tension at the time of heating in the second treatment varies depending on the type of the fiber material constituting the core wire 16, but is, for example, 0.002 to 0.040 N / dtex.

  The solid content adhesion amount of RFL to the core wire 16 is, for example, 0.5 to 8% by mass with respect to the dry mass of the core wire 16.

  This second treatment may be performed a single time or may be repeated a plurality of times, but is preferably repeated 2-3 times in order to obtain uniform adhesion.

-Third treatment (rubber paste treatment)-
The third treatment is a treatment in which the unbonded core wire 16 or the core wire 16 subjected to the first treatment and / or the second treatment is dipped in rubber paste and then dried.

  The rubber paste is a solution obtained by dissolving 1,2-polybutadiene in an organic solvent such as toluene or methyl ethyl ketone (MEK).

  1,2-polybutadiene is a polybutadiene having a 1,2-vinyl content of 20 to 90 mol%, and more preferably a 1,2-vinyl content of 60 to 90 mol%.

  The 1,2-polybutadiene may be maleic acid-modified 1,2-polybutadiene containing a maleic acid-modified moiety, or may be maleic anhydride-modified 1,2-polybutadiene containing a maleic anhydride-modified moiety. Further, both of them may be included. In this case, the acid monomer content (acid content) is preferably 4 to 25% by mass.

  Specific examples of 1,2-polybutadiene include Ricon (registered trademark) series and Ricobond (registered trademark) series manufactured by Sartomer Technology Company.

  The content of 1,2-polybutadiene in the rubber paste is, for example, 10 to 100% by mass.

  The rubber paste may additionally contain a rubber composition or the like.

  The solid content concentration of the rubber paste is, for example, 3 to 25% by mass. The viscosity of the rubber paste is, for example, 0.5 to 100 cP.

  The immersion time in the rubber paste in the third treatment is, for example, 0.2 to 5 seconds. The drying temperature in the third treatment is, for example, 55 to 120 ° C. The drying time in the third treatment is, for example, 30 seconds to 21 minutes. Although the tension | tensile_strength at the time of drying in a 3rd process changes also with the kind of fiber material which comprises the core wire 16, it is 0.002-0.030 N / dtex, for example.

  The solid content adhesion amount with the rubber paste to the core wire 16 is, for example, 0.5 to 10% by mass with respect to the dry mass of the core wire 16.

  Next, a method for manufacturing the V-ribbed belt B according to Embodiment 1 will be described with reference to FIGS. 3 (a) and 3 (b).

  In the manufacture of the V-ribbed belt B according to the first embodiment, an inner mold having a molding surface that forms the back surface of the belt in a predetermined shape on the outer periphery, and a rubber sleeve having a molding surface that forms the inner side of the belt in a predetermined shape on the inner periphery. And are used.

  First, an uncrosslinked rubber sheet 10a ′ for forming an outer portion of the inner die from the core 16 of the V-ribbed belt main body 10 is wound, and then an adhesive-treated thread 16 that becomes the core 16 is wound thereon. After 'is spirally wound, an uncrosslinked rubber sheet 10b' for forming an inner portion of the core wire 16 is further wound thereon. When the uncrosslinked rubber sheets 10a 'and 10b' include the short fibers 14, those in which the short fibers 14 are oriented in the direction orthogonal to the winding direction are used.

  After that, cover the molded body on the inner mold with a rubber sleeve, set it in the molding pot, heat the inner mold with high-temperature steam, etc., and press the rubber sleeve radially inward by applying high pressure To do. At this time, the rubber component flows and the crosslinking reaction proceeds. In addition, the adhesion reaction of the adhesion-treated yarn 16 ′ to the rubber also proceeds. Thereby, a cylindrical belt slab (belt body preform) is formed.

  Then, after removing the belt slab from the inner mold and dividing the belt slab into several pieces in the length direction, the outer periphery of each is polished and cut to form the V rib 13, that is, the pulley contact portion. At this time, the short fibers 14 exposed on the pulley contact surface may be protruded from the pulley contact surface, that is, the V rib 13 surface.

  Finally, the belt slab, which is divided and formed with the V ribs 13 on the outer periphery, is cut into a predetermined width and turned upside down to obtain the V-ribbed belt B according to the first embodiment.

  Next, an auxiliary machine drive belt transmission 40 provided in the engine room of an automobile using the V-ribbed belt B will be described.

  FIG. 4 shows a pulley layout of the accessory drive belt transmission 40. The accessory drive belt transmission 40 is of a serpentine drive type wound around six pulleys of four rib pulleys and two flat pulleys.

  The layout of the auxiliary drive belt transmission device 40 includes a power steering pulley 41 at the uppermost position, an AC generator pulley 42 disposed below the power steering pulley 41, and a flat pulley disposed at the lower left side of the power steering pulley 41. Tensioner pulley 43, flat pulley water pump pulley 44 disposed below tensioner pulley 43, crankshaft pulley 45 disposed on the lower left side of tensioner pulley 43, and disposed on the lower right side of crankshaft pulley 45. The air conditioner pulley 46 is configured. Among these, all except the tensioner pulley 43 and the water pump pulley 44 which are flat pulleys are rib pulleys. Then, the V-ribbed belt B is wound around the power steering pulley 41 so that the V-rib 13 side contacts, and then wound around the tensioner pulley 43 so that the belt rear surface comes into contact, and then the V-rib 13 side contacts. Are wound around the crankshaft pulley 45 and the air conditioner pulley 46 in turn, and further wound around the water pump pulley 44 so that the back surface of the belt contacts, and then wound around the AC generator pulley 42 so that the V rib 13 side contacts. Finally, it is provided so as to return to the power steering pulley 41.

(Embodiment 2)
FIG. 5 shows a V-ribbed belt B according to the second embodiment. In addition, the part of the same name as Embodiment 1 is shown with the same code | symbol as Embodiment 1. FIG.

  In the V-ribbed belt B according to the second embodiment, the V-ribbed belt main body 10 is configured as a double layer of an adhesive rubber layer 11 on the belt outer peripheral side and a compression rubber layer 12 on the belt inner peripheral side. A reinforcing cloth 15 is affixed to the belt outer peripheral surface, and a core wire 16 is embedded in the adhesive rubber layer 11 via an adhesive layer 17 so as to form a spiral having a pitch in the belt width direction. The adhesive layer 17 has a thin layer 18 containing 1,2-polybutadiene provided so as to surround the core wire 16.

  The adhesive rubber layer 11 is configured in a band shape having a horizontally long cross section, and has a thickness of, for example, 1.0 to 2.5 mm. The adhesive rubber layer 11 is formed of a rubber composition in which various compounding agents are blended with a rubber component.

  Examples of the rubber component of the rubber composition constituting the adhesive rubber layer 11 include ethylene-α-olefin elastomer rubbers such as ethylene / propylene rubber (EPR) and ethylene propylene diene monomer rubber (EPDM), chloroprene rubber (CR), Examples include chlorosulfonated polyethylene rubber (CSM) and hydrogenated acrylonitrile rubber (H-NBR). Of these, ethylene-α-olefin elastomer rubber is preferred from the viewpoint of environmental considerations and performance such as wear resistance and crack resistance. The rubber component may be composed of a single species or a blend of a plurality of species.

  Examples of the compounding agent for the rubber composition constituting the adhesive rubber layer 11 include a crosslinking agent (for example, sulfur and organic peroxide), an anti-aging agent, a processing aid, a plasticizer, and carbon black (iodine adsorption amount is 40 mg). And reinforcing materials such as a large particle size carbon black of / g or less) and fillers.

  The rubber composition forming the adhesive rubber layer 11 is obtained by heating and pressurizing an uncrosslinked rubber composition obtained by blending a rubber component with a compounding agent and kneading, and then crosslinking with a crosslinking agent.

  The compression rubber layer 12 is provided such that a plurality of V ribs 13 constituting a pulley contact portion hang down to the belt inner peripheral side. Each of the plurality of V ribs 13 is formed in a ridge having a substantially inverted triangular cross section extending in the belt length direction, and arranged in parallel in the belt width direction. Each V rib 13 is formed, for example, with a rib height of 2.0 to 3.0 mm and a width between base ends of 1.0 to 3.6 mm. The number of ribs is, for example, 3 to 6 (in FIG. 5, the number of ribs is 6). The compressed rubber layer 12 is formed of a rubber composition similar to the rubber composition forming the V-ribbed belt body 10 of the first embodiment.

  The reinforcing cloth 15 is composed of, for example, a woven cloth woven into plain weave, twill weave, satin weave or the like formed of yarns such as cotton, polyamide fiber, polyester fiber, and aramid fiber. In order to give the reinforcing cloth 15 an adhesive property to the V-ribbed belt main body 10, an adhesive treatment in which it is immersed in an RFL aqueous solution and heated before molding and / or a surface of the V-ribbed belt main body 10 side is coated with rubber paste. Adhesive treatment for drying is applied. In addition, the belt outer peripheral side surface portion may be made of a rubber composition instead of the reinforcing cloth 15. Further, the reinforcing cloth 15 may be composed of a knitted fabric.

  Next, a method for manufacturing the V-ribbed belt B according to the second embodiment will be described with reference to FIGS. 6 (a) and 6 (b).

  In the manufacture of the V-ribbed belt B according to the second embodiment, an inner mold having a molding surface for forming the back surface of the belt in a predetermined shape on the outer periphery, and a rubber sleeve having a molding surface for forming the inner side of the belt in a predetermined shape on the inner periphery. And are used.

  First, after coating the outer periphery of the inner mold with an adhesive-treated cloth 15 ′ to be a reinforcing cloth 15, an uncrosslinked rubber sheet 11b ′ for forming the outer portion 11b of the adhesive rubber layer 11 is wound thereon, Next, the adhesive-treated thread 16 ′ to be the core wire 16 is spirally wound thereon, and then an uncrosslinked rubber sheet 11 a ′ for forming the inner portion 11 a of the adhesive rubber layer 11 is wound thereon. Further, an uncrosslinked rubber sheet 12 ′ for forming the compressed rubber layer 12 is wound thereon. When the uncrosslinked rubber sheet 12 ′ forming the compressed rubber layer 12 includes the short fibers 14, the one in which the short fibers 14 are oriented in a direction orthogonal to the winding direction is used.

  After that, cover the molded body on the inner mold with a rubber sleeve, set it in the molding pot, heat the inner mold with high-temperature steam, etc., and press the rubber sleeve radially inward by applying high pressure To do. At this time, the rubber component flows and the crosslinking reaction proceeds. In addition, the adhesion reaction of the adhesion-treated yarn 16 ′ and the adhesion-treated cloth 15 ′ to the rubber also proceeds. Thereby, a cylindrical belt slab (belt body preform) is formed.

  Then, after removing the belt slab from the inner mold and dividing the belt slab into several pieces in the length direction, the outer periphery of each is polished and cut to form the V rib 13, that is, the pulley contact portion. At this time, the short fibers 14 exposed on the pulley contact surface may be protruded from the pulley contact surface, that is, the V rib 13 surface.

  Finally, the belt slab which is divided and formed with the V ribs 13 on the outer periphery is cut into a predetermined width, and the V-ribbed belt B according to the second embodiment is obtained by turning each side upside down.

  Other configurations, operations, and effects are the same as those of the first embodiment.

(Other embodiments)
In the first and second embodiments, the V-ribbed belt B is used. However, the present invention is not particularly limited thereto, and may be a low-edge type V-belt, a toothed belt, a flat belt, or the like.

(Adhesive treatment liquid)
The following adhesion treatment liquid was prepared. Each formulation is also shown in Table 1.

<Pretreatment liquid>
A solution obtained by mixing in a mass ratio of toluene 840 to isocyanate (trade name: Sumidur 44V20 manufactured by Sumika Bayer Urethane Co., Ltd.) 160 was prepared as a base treatment solution. This base treatment liquid had a solid content concentration of 16% by mass and a viscosity of 0.84 cP.

<RFL aqueous solution>
Resorcin (R) 9.2, 37% formalin (F) 13.5, sodium hydroxide (NaOH) 0.5, 2,3-dichlorobutadiene (2,3-DCB) rubber latex (manufactured by Tosoh Corporation) LH430) 266.7, and an RFL aqueous solution mixed at a mass ratio of water 710.1 were prepared. This RFL aqueous solution had a solid content concentration of 10% by mass and a viscosity of 10 cP.

  When preparing the RFL aqueous solution, resorcin (R), formalin (F) and sodium hydroxide (NaOH) are dissolved in water to prepare an aqueous solution, which is stirred for 2 hours to undergo a condensation reaction. Was added to a mixture of 2,3-dichlorobutadiene (2,3-DCB) rubber latex with the remaining water.

<Rubber glue 1>
Maleic acid-modified 1,2-polybutadiene (trade name: Ricobond 1756, manufactured by Sartomer Technology Company, 1,2-vinyl content 70 mol%, acid content 17% by mass) is mixed at a mass ratio of toluene 850 with respect to 150. The obtained solution was prepared as rubber paste 1. This rubber paste 1 had a solid content concentration of 15% by mass and a viscosity of 1.2 cP.

<Rubber paste 2>
1,2-polybutadiene (trade name: Ricon130, 1,2-vinyl content 28 mol%, acid content 0% by mass, manufactured by Sartomer Technology Company) 150 and a solution obtained by mixing at a mass ratio of toluene 850 Was adjusted as rubber paste 2. This rubber paste 2 had a solid content concentration of 15% by mass and a viscosity of 1.5 cP.

<Rubber paste 3>
1,2-polybutadiene (trade name: Ricon157, manufactured by Sartomer Technology Company, Inc., 150 mol% of 1,2-vinyl content, 0 mass% of acid content) 150 and a solution obtained by mixing at a mass ratio of toluene 850 Was adjusted as rubber paste 3. This rubber paste 3 had a solid content concentration of 15% by mass and a viscosity of 1.1 cP.

<Rubber paste 4>
Maleic acid-modified 1,2-polybutadiene (trade name: Ricobond1031, 1,2-vinyl content 25 mol%, acid content 10 mass%) manufactured by Sartomer Technology Company 150 was mixed at a mass ratio of toluene 850. The obtained solution was adjusted as rubber paste 4. This rubber paste 4 had a solid content concentration of 15% by mass and a viscosity of 1.6 cP.

<Rubber paste 5>
A solution obtained by mixing at a mass ratio of toluene 850 with 150 1,4-polybutadiene (trade name: BR01, 1,2-vinyl content 4 mol% or less, acid content 0 mass%) manufactured by JSR Corporation. The rubber paste 5 was adjusted. This rubber paste 5 had a solid content concentration of 15% by mass and a viscosity of 4.0 cP.

(Rubber composition)
The following rubber compositions A to C were prepared. Each formulation is also shown in Table 2.

<Rubber composition A>
EPDM (trade name: EP24 manufactured by JSR Corporation) is used as a rubber component, and 5 parts by mass of zinc oxide (trade name: Zinc Hana No. 1 manufactured by Sakai Chemical Industry Co., Ltd.) and stearic acid (NOF) Product name: Beads stearic acid 椿) 1 part by weight, anti-aging agent (trade name: NOCRACK MB, manufactured by Ouchi Shinsei Chemical Co., Ltd.) 1 part by weight, FEF carbon black (trade name: Seast SO, manufactured by Tokai Carbon Co., Ltd.) 60 parts by weight Part, Oil 1 (Nippon Sun Oil Co., Ltd., trade name: Thamper 2280) 10 parts by mass, Oil Sulfur (Tsurumi Chemical Co., Ltd., trade name: Oil Sulfur) 0.5 parts by mass, Organic peroxide cross-linking agent (NOF Corporation) Product name: Park Mill D) 4 parts by mass, co-crosslinking agent (trade name: High Cloth M, manufactured by Seiko Chemical Co., Ltd.) 2 parts by mass, and short fiber (Teijin Limited product name: Technora, fiber length 3 mm, bonded) 10 quality Parts were blended and kneaded, and it was rubber composition A.

<Rubber composition B>
A blend rubber obtained by mixing zinc methacrylate reinforced H-NBR (trade name: Zeoforte ZSC2295CX, manufactured by Nippon Zeon Co., Ltd.) and H-NBR (trade name: Zetpol 2020, manufactured by Nippon Zeon Co., Ltd.) at a mass ratio of the former / the latter = 70/30. As a rubber component, 5 parts by mass of zinc oxide (trade name: Zinc Hana 1 manufactured by Sakai Chemical Industry Co., Ltd.) and stearic acid (product name: manufactured by NOF Corporation: 1) 1 part by mass, anti-aging agent (trade name: NOCRACK MB, manufactured by Ouchi Shinsei Chemical Co., Ltd.), 40 parts by mass of FEF carbon black (trade name: Seast SO, manufactured by Tokai Carbon Co., Ltd.) Name: Adeka Sizer RS107) 10 parts by weight, oil sulfur (manufactured by Tsurumi Chemical Co., Ltd., trade name: oil sulfur) 0.5 parts by weight, organic peroxide crosslinking agent NOF Corporation, trade name: Percumyl D) 4 parts by weight, and a co-crosslinking agent (Seiko Chemical Co., Ltd. trade name: High Cross M) were blended and kneaded with 2 parts by weight, which was the rubber composition B.

<Rubber compounding C>
Rubber composition A except that 40 parts by mass of maleic acid-modified 1,2-polybutadiene (trade name: Ricobond1756, manufactured by Sartomer Technology Company) is blended with 100 parts by mass of the rubber component, and short fibers are not blended. The same rubber composition as above was compounded and kneaded to obtain rubber composition C.

(Test evaluation core)
The core wires of Examples 1 to 8 and Comparative Examples 1 to 4 below were produced. Each configuration is also shown in Table 3.

<Example 1>
The above ground treatment liquid is used for the core wire of a twisted yarn of an aromatic polyamide fiber (trade name: Technora manufactured by Teijin Ltd.) having a configuration of 1100 dtex / 1 × 3 (twisting number 20 times / 10 cm and upper twisting number 20 times / 10 cm). Example 1 in which the first treatment (primary treatment), the second treatment (RFL treatment) using the RFL aqueous solution, and the third treatment (rubber paste treatment) using the rubber paste 1 were performed. It was.

  In the first treatment, the immersion time in the base treatment solution was 1.2 seconds, the heating temperature was 245 ° C., the heating time was 60 seconds, and the tension during heating was 0.005 N / dtex. The solid content of the ground treatment agent with respect to the core wire was 3.4% by mass with respect to the dry mass of the core wire.

  In the second treatment, the immersion time in the RFL aqueous solution was 8 seconds, the heating temperature was 230 ° C., the heating time was 60 seconds, and the tension during heating was 0.006 N / dtex. In addition, the number of times of the second process is set to two. The solid content of RFL on the core wire was 5.4% by mass with respect to the dry mass of the core wire.

  In the third treatment, the immersion time in the rubber paste 1 was 1.2 seconds, the drying temperature was 100 ° C., the drying time was 60 seconds, and the tension during drying was 0.006 N / dtex. The solid content of rubber cord 1 with respect to the core wire was 2.5% by mass with respect to the dry mass of the core wire.

<Example 2>
A core wire subjected to the same adhesion treatment as in Example 1 except that rubber paste 2 was used in the third treatment was produced, and this was designated as Example 2. The solid content of rubber cord 2 with respect to the core wire was 3.0% by mass with respect to the dry mass of the core wire.

<Example 3>
A core wire subjected to the same adhesion treatment as in Example 1 except that rubber paste 3 was used in the third treatment was produced, and this was designated as Example 3. The solid content of rubber cord 3 on the core wire was 2.8% by mass relative to the dry mass of the core wire.

<Example 4>
A core wire subjected to the same adhesion treatment as in Example 1 except that rubber paste 4 was used in the third treatment was produced, and this was designated as Example 4. The amount of solid content adhered to the core wire by the rubber paste 4 was 4.5% by mass with respect to the dry mass of the core wire.

<Example 5>
A core wire subjected to the same adhesion treatment as that in Example 1 except that the second treatment was not applied was produced. The solid content of rubber cord 1 on the core wire was 3.6% by mass with respect to the dry mass of the core wire.

<Example 6>
A core wire that was subjected to the same adhesion treatment as in Example 1 except that the first and second treatments were not applied was produced. The amount of solid content adhered by the rubber paste 1 to the core wire was 5.8% by mass with respect to the dry mass of the core wire.

<Example 7>
Example 5 except that a strand of polyester fiber (trade name: Tetoron, manufactured by Teijin Co., Ltd.) with a configuration of 1100 dtex / 1 × 3 (the number of twists of 12 times / 10 cm and the number of twists of 12 times / 10 cm) was used. A core wire subjected to the same adhesion treatment as in Example 6 was produced and designated as Example 7. The solid content of the ground treatment agent with respect to the core wire was 3.1% by mass with respect to the dry mass of the core wire. The solid content of rubber cord 1 on the core wire was 2.3% by mass relative to the dry mass of the core wire.

<Example 8>
Except for the use of a strand of nylon 6,6 fiber (trade name: Leona, manufactured by Asahi Kasei Co., Ltd.) with a strand of 1400 dtex / 1 × 3 (15 twists / 10 cm and 15 twists / 10 cm). A core wire subjected to the same adhesion treatment as in Example 5 was produced, and this was designated as Example 8. The solid content of the ground treatment agent with respect to the core wire was 4.2% by mass relative to the dry mass of the core wire. The amount of solid content adhered to the core wire by the rubber paste 1 was 4.1% by mass with respect to the dry mass of the core wire.

<Comparative Example 1>
A core wire subjected to the same adhesion treatment as that of Example 1 except that the third treatment was not performed was produced, and this was designated as Comparative Example 1.

<Comparative Example 2>
A core wire subjected to the same adhesion treatment as in Example 7 except that the second treatment was applied instead of the third treatment was produced, and this was designated as Comparative Example 2. The amount of solid content of RFL attached to the core wire was 4.8% by mass relative to the dry mass of the core wire.

<Comparative Example 3>
A core wire subjected to the same adhesion treatment as in Example 8 except that the second treatment was applied instead of the third treatment was produced, and this was designated as Comparative Example 3. The solid content of RFL attached to the core wire was 5.5% by mass with respect to the dry mass of the core wire.

<Comparative example 4>
A core wire subjected to the same adhesion treatment as in Example 1 except that rubber paste 5 was used in the third treatment was produced, and this was designated as Comparative Example 4. The amount of solid content adhered by the rubber paste 5 to the core wire was 4.0% by mass with respect to the dry mass of the core wire.

(Test evaluation method)
<Dynamic adhesion evaluation>
For the core wires subjected to the adhesion treatments of Examples 1 to 8 and Comparative Examples 1 to 4, the rubber composition A is used as a rubber to be adhered, and a 1 cm × 1 cm × 2 cm rectangular rubber block as shown in FIG. A test piece 70 having a core wire 72 penetrating at the center of the long side surface of 71 and bonded thereto was press-molded.

  About the core wire which performed each adhesion process of Examples 1-4 and Comparative Examples 1 and 4, the rubber composition B was made into the rubber | gum and the same test piece was press-molded.

  For the core wire subjected to the adhesion treatment of Example 1, a similar test piece was press-molded using the rubber composition C as the adherend rubber. The combination of the core wire of Example 1 and the rubber composition C is referred to as Comparative Example 5.

  Then, as shown in FIG. 8, a rubber block 71 is attached to a C-shaped rubber fixing jig 82 attached to the load cell 81 provided above so as to open downward so that the core wire hangs from the opening. While fixing, the test piece 70 was set by fixing the tip of the core wire 72 to the chuck 83 provided below. Under a temperature atmosphere of 130 ° C., load vibration with a load width of 0 to 58.8 N and a frequency of 10 Hz was applied to the core wire 72 by the chuck 83, and the number of vibrations until the core wire 72 pulled out from the rubber block 71 was measured.

<Belt running evaluation>
Using the cores of Examples 1 to 6 and Comparative Examples 1 and 4, a V-ribbed belt having the same configuration as that of Embodiment 1 in which the V-ribbed belt body was formed of the rubber composition A was produced. The belt peripheral length was 1000 mm, the belt width was 10.68 mm, the belt thickness was 4.8 mm, and the number of ribs was three.

  Using the core wire of Example 1, an adhesive rubber layer is formed of rubber composition C and a compression rubber layer is formed of rubber composition A, respectively, and a V-ribbed belt having the same configuration as in Embodiment 2 in which no reinforcing cloth is provided is manufactured. (Comparative Example 5). The belt peripheral length was 1000 mm, the belt width was 10.68 mm, the belt thickness was 4.8 mm, and the number of ribs was three.

  FIG. 9 shows a pulley layout of the belt running test machine 90.

  The belt running test machine 90 includes a driving rib pulley 91 having a pulley diameter of 120 mm provided at the lowermost portion, a driven rib pulley 92 having a pulley diameter of 120 mm provided thereon, and a pulley diameter provided in the middle in the vertical direction thereof. A 70 mm idler flat pulley 93 and a tension rib pulley 94 having a pulley diameter of 55 mm, which is provided on the right side of the idler flat pulley 93 and is movable to the left and right.

  The V-ribbed belt B is wound around the belt running tester 90 around each of the drive rib pulley 91, the driven rib pulley 92, and the tension rib pulley 94 so that the rib portions are in contact with each other, and the idler flat surface is provided so that the back surface of the belt is in contact with the belt running tester 90. The pulley 93 is wound around, and a load of 11.8 kW is applied to the driven rib pulley 92 and a tension of 834 N is applied to the left side of the tension rib pulley 94 and fixed. The belt was rotated at a rotational speed of 4900 rpm to run the V-ribbed belt B, and the running time until the core wire peeled off from the V-ribbed belt body and jumped out was measured as the belt running life. In Comparative Example 5 only, the running time when a crack occurred in the adhesive rubber layer was defined as the belt running life.

  In addition, the initial strength of the unrunned V-ribbed belt was measured, and the strength of the V-ribbed belt that was run for 200 hours (72 hours for Comparative Example 4) in the running test similar to the above was measured. The strength maintenance ratio of the strength after running the belt with respect to the strength was calculated.

(Test evaluation results)
Table 4 shows the test evaluation results.

  According to Table 4, when the rubber to be adhered is rubber composition A, the dynamic adhesiveness is 20980 times in Example 1, 15230 times in Example 2, 16570 times in Example 3, and 17420 times in Example 4. Example 5 is 16730 times, Example 6 is 14170 times, Example 7 is 58640 times, and Example 8 is 35120 times, while Comparative Example 1 is 2460 times, Comparative Example 2 is 9860 times, Comparative Example 3 was 9080 times and Comparative Example 4 was 4110 times. When the rubber to be adhered is the rubber composition B, Example 1 is 46200 times, Example 2 is 23340 times, Example 3 is 27110 times, and Example 4 is 30190 times, while Comparative Example 1 is 6050 times and 4920 times of Comparative Example 4. Further, when the adherend rubber was the rubber composition C, the comparative example 5 was 25110 times.

  The belt running life is 1000 hours for Example 1, 513 hours for Example 2, 502 hours for Example 3, 678 hours for Example 4, 606 hours for Example 5, and 453 hours for Example 6. On the other hand, Comparative Example 1 was 192 hours, Comparative Example 4 was 72 hours, and Comparative Example 5 was 514 hours.

  The strength maintenance ratio is 91% in Example 1, 83% in Example 2, 88% in Example 3, 84% in Example 4, 85% in Example 5, and 80% in Example 6. On the other hand, Comparative Example 1 was 61%, Comparative Example 4 was 63%, and Comparative Example 5 was 55%.

  The thicknesses of the thin layers are 2.1 μm in Example 1, 1.5 μm in Example 2, 1.1 μm in Example 3, 1.8 μm in Example 4, 1.8 μm in Example 5, and Example 6 was 2.3 μm, while Comparative Example 1 was 1.9 μm and Comparative Example 4 was 1.7 μm.

  INDUSTRIAL APPLICABILITY The present invention is useful for a transmission belt in which a core wire is embedded in a rubber belt main body through an adhesive layer.

3 is a perspective view of a V-ribbed belt according to Embodiment 1. FIG. It is the elements on larger scale of the cross section of a V ribbed belt. (A) And (b) is explanatory drawing which shows the manufacturing method of the V-ribbed belt which concerns on Embodiment 1. FIG. It is a figure which shows the pulley layout of an auxiliary machine drive belt transmission. 6 is a perspective view of a V-ribbed belt according to Embodiment 2. FIG. (A) And (b) is explanatory drawing which shows the manufacturing method of the V ribbed belt which concerns on Embodiment 2. FIG. It is a perspective view which shows the test piece of dynamic adhesive evaluation. It is explanatory drawing which shows the test method of dynamic adhesiveness evaluation. It is a figure which shows the pulley layout of a belt running test machine.

Explanation of symbols

B V-ribbed belt 10 V-ribbed belt body 16 Core wire 17 Adhesive layer 18 Thin layer

Claims (5)

A transmission belt in which a core wire is embedded in a rubber belt body via an adhesive layer,
The adhesive layer has a thin layer containing 1,2-polybutadiene, which is a polybutadiene in which 20 to 90 mol% of 1,3-butadiene monomer is 1,2-added and is provided so as to surround the core wire. belt. The power transmission belt according to claim 1,
A transmission belt having a thickness of the thin layer of 0.1 to 200 μm. A transmission belt in which a core wire is embedded in a rubber belt body via an adhesive layer,
The core wire is subjected to a treatment to be dried after being immersed in a rubber paste containing 1,2-polybutadiene, which is a 1,2-added polybutadiene of 20 to 90 mol% of 1,3-butadiene monomer. belt. The power transmission belt according to any one of claims 1 to 3,
A transmission belt wherein the 1,2-polybutadiene is maleic acid-modified 1,2-polybutadiene or maleic anhydride-modified 1,2-polybutadiene. The transmission belt according to claim 4,
The 1,2-polybutadiene is a transmission belt having an acid monomer content of 4 to 25% by mass.

Images