Transmission belt, its manufacturing method and core wire

Abstract

The power transmission belt (B) has a core wire (12) embedded in an elastomer belt body (11). The core wire (12) is subjected to an adhesion treatment in which it is immersed in a first treating agent containing an epoxy compound and a blocked isocyanate compound and heated, and then immersed in a second treating agent containing a silane coupling agent and heated.

Description

[Technical field]

[0001] The present invention relates to a power transmission belt, a method for producing the same, and a core wire thereof. [Background technology]

[0002] The core wires embedded in the belt body of the power transmission belt are subjected to an adhesive treatment for bonding to the belt body. For example, Patent Document 1 discloses that for carbon fibers for reinforcing rubber used in power transmission belts, etc., a carbon fiber bundle is treated with a first bath liquid containing a urethane resin as a main component, and then treated with a second bath liquid of an RFL adhesive containing a polynuclear chlorophenol compound. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-241502 A Summary of the Invention

[0004] The present invention relates to a power transmission belt having a core wire embedded in an elastomer belt body, the core wire being immersed in a first treatment agent containing an epoxy compound and a blocked isocyanate compound, and then treated with a silane coupling agent. The first solution of the agent 2. The adhesive is treated by immersing the material in a treatment agent and heating it.

[0005] The present invention relates to a core wire to be embedded in an elastomer belt body of a transmission belt, the core wire being immersed in a first treatment agent containing an epoxy compound and a blocked isocyanate compound, heated, and then treated with a silane coupling agent. The first solution of the agent 2. The adhesive is treated by immersing the material in a treatment agent and heating it.

[0006] The present invention is a method for producing a power transmission belt having a core wire embedded in an elastomer belt body, the method comprising the steps of: (a) applying an adhesive treatment to the core wire; and (b) immersing and heating the core wire in a first treatment agent containing an epoxy compound and a blocked isocyanate compound, and (c) applying an adhesive to the core wire by a silane coupling agent after the first treatment step. The first solution of the agent and a second treatment step of immersing the material in a second treatment agent and heating the material. [Brief description of the drawings]

[0007] [Figure 1A] FIG. 2 is a perspective view of one piece of a toothed belt according to an embodiment. [Figure 1B] FIG. 2 is a vertical cross-sectional view of a portion of a toothed belt according to an embodiment. [Figure 2A] FIG. 2 is a first explanatory diagram of a method for producing a toothed belt according to the embodiment. [Figure 2B] FIG. 4 is a second explanatory diagram of the method for producing a toothed belt according to the embodiment. [Figure 2C] FIG. 6 is a third explanatory diagram of the method for producing a toothed belt according to the embodiment. [Diagram 3] FIG. 2 is a perspective view of an adhesive test piece. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, the embodiments will be described in detail with reference to the drawings.

[0009] 1A and 1B show a toothed belt B according to an embodiment. The toothed belt B according to the embodiment is a meshing power transmission belt, and is suitably used for high-load power transmission applications such as machine tools, printing machines, textile machines, and injection molding machines. The belt length of the toothed belt B is, for example, 500 mm or more and 3000 mm or less. The belt width is, for example, 10 mm or more and 200 mm or less. The belt thickness (maximum) is, for example, 3 mm or more and 20 mm or less.

[0010] The toothed belt B according to the embodiment includes an endless toothed belt main body 11 made of an elastomer formed from a polyurethane composition. The toothed belt main body 11 has a flat belt portion 111 having a horizontally elongated rectangular cross section, and a plurality of tooth portions 112 integrally provided on the inner peripheral side thereof. The plurality of tooth portions 112 are provided at regular intervals in the belt length direction.

[0011] Examples of the tooth shape of the toothed portion 112 in a side view include an STS tooth shape with both sides bulging outward in an arc shape and a trapezoidal tooth shape. The number of teeth in the toothed portion 112 is, for example, 30 to 400. The tooth width (maximum dimension in the belt length direction) is, for example, 2 mm to 10 mm. The tooth height is, for example, 2 mm to 8 mm. The arrangement pitch is, for example, 8 mm to 14 mm.

[0012] The polyurethane composition forming the toothed belt body 11 is a liquid urethane composition obtained by mixing a urethane prepolymer with compounding agents such as a hardener and a plasticizer, and then curing the liquid urethane composition by heating and pressurizing it.

[0013] The urethane prepolymer is a relatively low molecular weight urethane compound having multiple NCO groups at the terminals, which is obtained by the reaction of an isocyanate component with a polyol component. Examples of the isocyanate component include tolylene 2,4-diisocyanate (TDI) and 4,4'-diphenylmethane diisocyanate (MDI). Examples of the polyol component include polytetramethylene ether glycol (PTMG). The urethane prepolymer may be composed of a single urethane compound or may be composed of a mixture of multiple urethane compounds.

[0014] Examples of the curing agent include amine compounds such as 1,4-phenylenediamine, 2,6-diaminotoluene, 1,5-naphthalenediamine, 4,4'-diaminodiphenylmethane, and 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA). The curing agent preferably contains one or more of these. The amine compound curing agent is preferably blended so that the α value (NH2 group / NCO group), which is the ratio of the number of moles of NH2 group in the curing agent to the number of moles of NCO group in the urethane prepolymer, is 0.70 or more and 1.10 or less.

[0015] Examples of the plasticizer include dialkyl phthalates such as dibutyl phthalate (DBP) and dioctyl phthalate (DOP); dialkyl adipates such as dioctyl adipate (DOA); and dialkyl sebacates such as dioctyl sebacate (DOS). The plasticizer preferably contains one or more of these. The amount of the plasticizer is, for example, 3 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the urethane prepolymer.

[0016] Examples of other additives include colorants, antifoaming agents, and stabilizers.

[0017] The hardness of the polyurethane composition forming the toothed belt body 11 is, for example, not less than 70° and not more than 100°. The hardness of this polyurethane composition is measured based on JIS K7312:1996.

[0018] In the toothed belt B according to the embodiment, a core wire 12 is embedded in a flat belt portion 111 of a toothed belt main body 11. The outer diameter D of the core wire 12 is, for example, not less than 0.4 mm and not more than 2.7 mm.

[0019] From the viewpoint of obtaining high durability, the core wire 12 is preferably a twisted yarn. Examples of the twisted yarn constituting the core wire 12 include single twisted yarn, double twisted yarn, and Lang twisted yarn. The twisted yarn core wire 12 may be an S twisted yarn, a Z twisted yarn, or both.

[0020] Examples of fiber materials forming the core wire 12 include inorganic fibers such as carbon fibers, glass fibers, metal fibers, etc., and organic fibers such as aliphatic polyamide fibers, aromatic polyamide fibers, polyethylene terephthalate fibers, polyethylene naphthalate fibers, polyvinyl alcohol fibers, etc. Of these, the core wire 12 is preferably formed of carbon fibers from the viewpoint of obtaining high durability.

[0021] The core wires 12 are arranged to form a spiral having a pitch in the belt width direction. The core wires 12 may be composed of two threads, an S twisted thread and a Z twisted thread, which are arranged to form a double spiral. The core wires 12 are arranged to extend in parallel at intervals in the belt width direction, and in this case, the number of core wires 12 per 10 mm of belt width is, for example, 3 threads / 10 mm or more and 16 threads / 10 mm or less.

[0022] The core wire 12 is subjected to an adhesive treatment in which it is immersed in a first treatment agent, which is an aqueous liquid containing an epoxy compound and a blocked isocyanate compound, pulled out and heated, and then immersed in a second treatment agent, which is an aqueous liquid containing a silane coupling agent, pulled out and heated.

[0023] Examples of the epoxy compound contained in the first treatment agent include glycerol polyglycidyl ether, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, etc. The epoxy compound preferably contains one or more of these, and more preferably contains glycerol polyglycidyl ether from the viewpoint of obtaining high adhesion of the core wire 12 to the toothed belt body 11.

[0024] From the viewpoint of obtaining high adhesion of the core wire 12 to the toothed belt body 11, the epoxy compound has an epoxy equivalent of preferably from 140 to 160, more preferably from 145 to 155. From the same viewpoint, the epoxy compound has a total chlorine content of preferably from 5 to 15% by mass, more preferably from 8 to 12% by mass.

[0025] From the viewpoint of obtaining high adhesion of the core wire 12 to the toothed belt body 11, the content of the epoxy compound in the first treatment agent is preferably 3 mass % or more and 9 mass % or less, and more preferably 5 mass % or more and 7 mass % or less.

[0026] The blocked isocyanate compound contained in the first treating agent is an isocyanate compound in which the NCO group is blocked with a blocking agent.

[0027] Examples of the isocyanate compound constituting the blocked isocyanate compound include 4,4'-diphenylmethane diisocyanate (MDI), tolylene 2,4-diisocyanate (TDI), polymethylene polyphenyl diisocyanate, hexamethylene diisocyanate, and polyaryl polyisocyanate.

[0028] Examples of blocking agents include oximes such as methyl ethyl ketone oxime (MEKO), acetoxime, and cyclohexanone oxime; lactams such as ε-caprolactam and valerolactam; and phenols such as phenol, cresol, and resorcin.

[0029] The isocyanate compound constituting the blocked isocyanate compound is preferably 4,4'-diphenylmethane diisocyanate (MDI) from the viewpoint of obtaining high adhesion of the core wire 12 to the toothed belt body 11. From the same viewpoint, the blocking agent is preferably an oxime, more preferably methyl ethyl ketone oxime (MEKO). From the same viewpoint, the blocked isocyanate compound preferably contains MDI in which the NCO group is blocked with MEKO.

[0030] From the viewpoint of obtaining high adhesion of the core wire 12 to the toothed belt body 11, the dissociation temperature of the blocked isocyanate compound is preferably 160° C. or lower, and more preferably 140° C. or lower.

[0031] The content of the blocked isocyanate compound in the first treatment agent is preferably 6% by mass or more and 12% by mass or less, more preferably 8% by mass or more and 10% by mass or less, from the viewpoint of obtaining high adhesion of the core wire 12 to the toothed belt body 11. The content of the blocked isocyanate compound in the first treatment agent is preferably higher than the content of the epoxy compound. From the same viewpoint, the mass ratio of the content of the blocked isocyanate compound to the content of the epoxy compound in the first treatment agent (content of blocked isocyanate compound / content of epoxy compound) is preferably 1.1 or more and 2 or less, more preferably 1.4 or more and 1.6 or less.

[0032] The first treatment agent may contain, in addition to the epoxy compound and the blocked isocyanate compound, a curing agent for the epoxy compound, a surfactant, and the like.

[0033] From the viewpoint of obtaining high adhesion of the core wire 12 to the toothed belt body 11, the solid content concentration of the first treatment agent is preferably 5% by mass or more and 25% by mass or less, and more preferably 10% by mass or more and 20% by mass or less.

[0034] The heating temperature (set temperature in the heating furnace) after immersing the core wire 12 in the first treatment agent is preferably 140° C. or more and 200° C. or less, more preferably 160° C. or more and 180° C. or less, from the viewpoint of obtaining high adhesion of the core wire 12 to the toothed belt body 11. From the same viewpoint, the heating time is preferably 300 seconds or more and 720 seconds or less, more preferably 420 seconds or more and 600 seconds or less.

[0035] In order to obtain high adhesion of the core wire 12 to the toothed belt main body 11, the solid content of the first treatment agent adhered to the core wire 12 is preferably 2 mass% or more and 10 mass% or less, and more preferably 3 mass% or more and 6 mass% or less, relative to the mass of the core wire 12.

[0036] Examples of the silane coupling agent contained in the second treatment agent include amino-based silane coupling agents, epoxy-based silane coupling agents, vinyl-based silane coupling agents, methacrylic acid-based silane coupling agents, mercapto and sulfur-based silane coupling agents, ureido-based silane coupling agents, and isocyanate-based silane coupling agents.

[0037] Examples of amino-based silane coupling agents include 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, and 3-(N-phenyl)aminopropyltrimethoxysilane.

[0038] Examples of the epoxy-based silane coupling agent include 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropyltriethoxysilane.

[0039] Examples of the vinyl-based silane coupling agent include vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris(2-methoxyethoxy)silane, and vinylmethyldimethoxysilane.

[0040] Examples of the methacrylic acid-based silane coupling agent include 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, and the like.

[0041] Examples of mercapto and sulfur-based silane coupling agents include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and 3-octanoylthio-1-propyltriethoxysilane.

[0042] An example of the ureido-based silane coupling agent is 3-ureidopropyltriethoxysilane.

[0043] Examples of the isocyanate-based silane coupling agent include 3-isocyanatepropyltriethoxysilane, 3-isocyanatepropyltrimethoxysilane, and the like.

[0044] It is preferable that the silane coupling agent contains one or more of these, and from the viewpoint of obtaining high adhesion of the core wire 12 to the toothed belt body 11, it is more preferable that the silane coupling agent contains an amino-based silane coupling agent, and it is even more preferable that the silane coupling agent contains 3-aminopropyltriethoxysilane and / or N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane.

[0045] From the viewpoint of obtaining high adhesion of the core wire 12 to the toothed belt body 11, the content of the silane coupling agent in the second treatment agent is preferably 3% by mass or more and 15% by mass or less, and more preferably 8% by mass or more and 12% by mass or less.

[0046] The second treatment agent may contain other components in addition to the silane coupling agent.

[0047] From the viewpoint of obtaining high adhesion of the core wire 12 to the toothed belt body 11, the solid content concentration of the second treatment agent is preferably 3 mass % or more and 15 mass % or less, and more preferably 8 mass % or more and 12 mass % or less.

[0048] The heating temperature (set temperature in the heating furnace) after immersing the core wire 12 in the second treatment agent is preferably 210° C. or more and 270° C. or less, more preferably 230° C. or more and 250° C. or less, from the viewpoint of obtaining high adhesion of the core wire 12 to the toothed belt body 11. From the same viewpoint, the heating time is preferably 300 seconds or more and 720 seconds or less, more preferably 420 seconds or more and 600 seconds or less.

[0049] In order to obtain high adhesion of the core wire 12 to the toothed belt body 11, the solid content of the second treatment agent adhered to the core wire 12 is preferably 1 mass% or more and 6 mass% or less, and more preferably 2 mass% or more and 4 mass% or less, relative to the mass of the core wire 12.

[0050] In the toothed belt B according to the embodiment, a nonwoven fabric 13 is embedded along the belt length direction on the inner circumferential side of the position where the core wire 12 is embedded in the belt thickness direction in the toothed belt main body 11. The nonwoven fabric 13 may be composed of either one sheet or multiple sheets.

[0051] The nonwoven fabric 13 contains a polyurethane composition that forms the toothed belt main body 11, and is provided so as to form a layer in a side view. The portions of the nonwoven fabric 13 that correspond to the tooth portions 112 penetrate into the tooth portions 112 so as to bulge outward in a side view and spread thickly in the belt thickness direction. The portions of the nonwoven fabric 13 that correspond to the spaces between the tooth portions 112 are in contact with the core wire 12 and are compressed thin in the belt thickness direction.

[0052] Examples of fiber materials constituting the nonwoven fabric 13 include nylon fibers, polyester fibers, aramid fibers, polyketone fibers, carbon fibers, etc. It is preferable that the nonwoven fabric 13 is subjected to an adhesive treatment such as immersing it in a liquid adhesive and then drying it before molding.

[0053] According to the toothed belt B of the embodiment having the above-mentioned configuration, the core wire 12 is subjected to an adhesion treatment in which it is immersed in a first treating agent containing an epoxy compound and a blocked isocyanate compound and heated, and then immersed in a second treating agent containing a silane coupling agent and heated, thereby obtaining high adhesion of the core wire 12 to the elastomer toothed belt main body 11.

[0054] Next, a method for producing the toothed belt B according to the embodiment will be described.

[0055] The manufacturing method of the toothed belt B of the embodiment includes a urethane composition preparation process for preparing a liquid urethane composition for forming the toothed belt main body 11, a core wire bonding process for applying an adhesive treatment to the core wire 12, and a nonwoven fabric bonding process for applying an adhesive treatment to the nonwoven fabric 13.

[0056] In the urethane composition preparation step, compounding ingredients such as a curing agent and a plasticizer are mixed with the urethane prepolymer to prepare a liquid urethane composition.

[0057] In the core wire bonding process, a dipping device is used to bond the core wire 12. In the dipping device, a payout bobbin attachment section is provided on the upstream side and a take-up bobbin attachment section is provided on the downstream side, and a treatment agent tank is provided on the upstream side of the core wire running path between them and a heating furnace is provided on the downstream side.

[0058] In the first treatment step, a bobbin wound with the core wire 12 before the adhesive treatment is attached to the pay-out bobbin mounting section and an empty bobbin is attached to the take-up bobbin mounting section, respectively, and the first treatment agent is filled in the treatment agent tank, and the temperature inside the heating furnace is raised to a predetermined set temperature. The core wire 12 is paid out from the bobbin attached to the pay-out bobbin mounting section, passed through the core wire running path, and wound around the bobbin attached to the take-up bobbin mounting section. The core wire 12 is made to run from the pay-out bobbin mounting section to the take-up bobbin mounting section. As a result, the core wire 12 is immersed in the first treatment agent containing an epoxy compound and a blocked isocyanate compound in the treatment agent tank, pulled up, introduced into the heating furnace and heated, and then continuously wound around the bobbin at the take-up bobbin mounting section. The bobbin wound with the core wire 12 after the first treatment step is removed from the take-up bobbin mounting section. This first treatment step may be performed only once or may be performed repeatedly multiple times.

[0059] In the second treatment step, the bobbin on which the core wire 12 after the first treatment step is wound is attached to the pay-out bobbin mounting section, and the empty bobbin is attached to the take-up bobbin mounting section, respectively, the first treatment agent in the treatment agent tank is replaced with the second treatment agent, and the temperature inside the heating furnace is changed to a predetermined set temperature. The core wire 12 is paid out from the bobbin attached to the pay-out bobbin mounting section, passed through the core wire running path, and wound around the bobbin attached to the take-up bobbin mounting section. The core wire 12 is made to run from the pay-out bobbin mounting section to the take-up bobbin mounting section. As a result, the core wire 12 is immersed in the second treatment agent containing a silane coupling agent in the treatment agent tank, pulled up, introduced into the heating furnace and heated, and then continuously wound around the bobbin at the take-up bobbin mounting section. The bobbin on which the core wire 12 after the second treatment step is wound is removed from the take-up bobbin mounting section. This second treatment step may also be performed once or may be performed repeatedly multiple times.

[0060] In the nonwoven fabric bonding process, a bonding treatment is performed in which the nonwoven fabric 13 is immersed in a liquid adhesive and then dried.

[0061] After preparing the above-mentioned components, adhesively treated nonwoven fabric 13 is placed over cylindrical inner die 21, and adhesively treated core wire 12 is spirally wound thereon, as shown in Fig. 2A. At this time, grooves 22 extending in the axial direction and having a cross section corresponding to the tooth portion 112 are provided at regular intervals in the circumferential direction on the outer periphery of inner die 21, and ridges 23 extending in the axial direction are formed between each groove 22. Therefore, nonwoven fabric 13 and core wire 12 are supported by ridges 23.

[0062] 2B, the inner die 21 is housed in a cylindrical outer die 24. At this time, a cavity C for molding the toothed belt main body is formed between the inner die 21 and the outer die 24.

[0063] Next, as shown in FIG. 2C, a liquid urethane composition is injected into the sealed cavity C to fill it, and is heated. At this time, the urethane composition flows and hardens to form a toothed belt main body 11 of the polyurethane composition. Also, teeth 112 are formed in the grooves 22. The core wire 12 is adhered to and embedded in the toothed belt main body 11. Furthermore, the nonwoven fabric 13 is impregnated with the urethane composition and hardens, and is adhered to and embedded in the toothed belt main body 11. In this manner, the toothed belt main body 11, the core wire 12, and the nonwoven fabric 13 are integrated into a composite to form a cylindrical belt slab S.

[0064] Finally, the belt slab S is removed from the inner die 21 and the outer die 24 and cut into rings to obtain the toothed belt B according to the embodiment.

[0065] In the above embodiment, the toothed belt B is composed of the toothed belt main body 11, the core wire 12, and the nonwoven fabric 13, but this is not particularly limited, and a reinforcing cloth may be provided on the toothed portion side surface on the inner circumference side of the toothed belt main body and / or on the back surface on the outer circumference side of the toothed belt main body.

[0066] In the above embodiment, the toothed belt B has the toothed belt body 11 formed of a polyurethane composition, but the toothed belt body may be formed of a crosslinked rubber composition. In that case, after the second treatment step, the core wire 12 may be subjected to an RFL treatment step of immersing in an RFL aqueous solution and then heating, and / or a rubber cement treatment step of immersing in rubber cement and then heating.

[0067] In the above embodiment, the toothed belt B is used as the power transmission belt, but the present invention is not limited to this, and may be a flat belt, a V-belt, a V-ribbed belt, or the like. EXAMPLES

[0068] (Core) The adhesive-treated core wires of the following Examples 1 to 4 and Comparative Example were produced. The configurations of each are also shown in Table 1.

[0069] <Example 1> As the core wire, a single-twist yarn was prepared by twisting a bundle of 12,000 carbon fiber filaments with a filament diameter of 7 μm in one direction.

[0070] An aqueous first treatment agent with a solids concentration of 15 mass% was prepared, containing 5.91 mass% of the epoxy compound glycerol polyglycidyl ether (epoxy equivalent: 141, total chlorine content: 9 mass%), 8.88 mass% of MDI (dissociation temperature: 120°C or higher) in which the NCO group of a blocked isocyanate compound has been blocked with MEKO, 0.07 mass% of an imidazole-based epoxy resin curing agent, 0.15 mass% of a surfactant, and 85 mass% of water.

[0071] An aqueous second treatment agent with a solids concentration of 5 mass % was prepared, containing 5 mass % of 3-aminopropyltriethoxysilane, an amino-silane coupling agent, and 95 mass % of water.

[0072] The core wire was subjected to an adhesion treatment including a first treatment step of immersing in a first treatment agent and heating, and a second treatment step of subsequently immersing in a second treatment agent and heating. In this case, the heating temperature in the first treatment step was 170°C and the heating time was 470 seconds. In the second treatment step, the heating temperature was 240°C and the heating time was 470 seconds. The obtained core wire subjected to the adhesion treatment was designated as Example 1.

[0073] <Example 2> Example 2 was a core wire that had been subjected to an adhesive treatment in the same manner as in Example 1, except that the second treatment agent used had a solid content concentration of 10 mass %.

[0074] <Example 3> Example 3 was a core wire that had been subjected to an adhesive treatment in the same manner as in Example 1, except that N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane was used as the amino-based silane coupling agent in the second treatment agent.

[0075] <Example 4> Example 4 was a core wire that had been subjected to an adhesive treatment in the same manner as in Example 3, except that the second treatment agent used had a solid content concentration of 10 mass %.

[0076] <Comparative Example> The comparative example was a core wire that had been subjected to an adhesive treatment in the same manner as in Examples 1 to 4, except that the second treatment step was not carried out.

[0077] An attempt was made to prepare a one-liquid treatment agent containing all of the epoxy compound, blocked isocyanate compound, and amino-silane coupling agent, but it gelled, making it impossible to obtain a solution that could be used for adhesion treatment.

[0078] [Table 1]

[0079] (Urethane composition) A liquid urethane composition A was prepared by blending 16.58 parts by mass of MOCA as a curing agent and 1.6 parts by mass of a colorant with 100 parts by mass of a urethane prepolymer having TDI as an isocyanate component and PTMG as a polyol component.

[0080] (Test Method and Results) For the core wires subjected to the adhesive treatment of each of Examples 1 to 4 and the Comparative Example, adhesive test pieces T as shown in Fig. 3 were prepared. For this adhesive test piece T, a urethane block piece U of the polyurethane composition having a thickness of 5 mm and a square of 10 mm was formed by curing the urethane composition A, and a core wire V cut to a short length was embedded in the center so that one tip end penetrated through the thickness direction.

[0081] Using a tensile tester, the urethane block piece U of the adhesive test piece T was attached to one chuck and the core wire V was attached to the other chuck, and the pull-out force required to pull the core wire V from the urethane block piece U was measured at an atmospheric temperature of 25°C and a tensile speed of 500 mm / min, and this was divided by the embedded length of the core wire V, 5 mm, to calculate the pull-out adhesive strength per mm. The test results are shown in Table 1. [Industrial Applicability]

[0082] The present invention is useful in the technical fields of power transmission belts, their manufacturing methods, and core wires. [Explanation of symbols]

[0083] B Toothed belt (power transmission belt) C Cavity S Belt Slab T Adhesive test piece U Urethane block piece V core wire 11 Toothed belt body 111 Flat belt 112 Teeth 12 Core Wire 13 Nonwoven fabrics 21 Inner mold 22 Groove 23 protrusion 24 Outer mold

Claims

1. A power transmission belt having a core wire embedded in an elastomer belt body, The power transmission belt has a core wire that has been subjected to an adhesion treatment in which the core wire is immersed in a first treating agent containing an epoxy compound and a blocked isocyanate compound and heated, and then immersed in a second treating agent containing a silane coupling agent and heated.

2. The power transmission belt according to claim 1, The belt body is formed of a polyurethane composition.

3. The power transmission belt according to claim 1, A power transmission belt, the core being formed of carbon fiber.

4. The power transmission belt according to claim 1, The power transmission belt, wherein the epoxy compound comprises polyglycerol polyglycidyl ether.

5. The power transmission belt according to claim 1, A power transmission belt, wherein the content of the epoxy compound in the first treatment agent is 3% by mass or more and 9% by mass or less.

6. The power transmission belt according to claim 1, The power transmission belt, wherein the blocked isocyanate compound contains 4,4'-diphenylmethane diisocyanate in which an NCO group is blocked with methyl ethyl ketone oxime.

7. The power transmission belt according to claim 1, A power transmission belt, wherein the content of the blocked isocyanate compound in the first treatment agent is 6% by mass or more and 12% by mass or less.

8. The power transmission belt according to claim 1, A power transmission belt, wherein the content of the blocked isocyanate compound in the first treatment agent is greater than the content of the epoxy compound.

9. The power transmission belt according to claim 8, a mass ratio of a content of the blocked isocyanate compound to a content of the epoxy compound in the first treatment agent is 1.1 or more and 2 or less.

10. The power transmission belt according to claim 1, A power transmission belt, wherein an adhesion amount of the solid content of the first treatment agent to the core wire is 2 mass % or more and 10 mass % or less with respect to a mass of the core wire.

11. The power transmission belt according to claim 1, The power transmission belt, wherein the silane coupling agent comprises an amino-silane coupling agent.

12. The power transmission belt according to claim 11, The power transmission belt, wherein the silane coupling agent contains an amino-based silane coupling agent, 3-aminopropyltriethoxysilane and / or N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane.

13. The power transmission belt according to claim 1, A power transmission belt, wherein an adhesion amount of the solid content of the second treatment agent to the core wire is 1 mass % or more and 6 mass % or less with respect to a mass of the core wire.

14. A core wire embedded in an elastomer belt body of a power transmission belt, The core wire is subjected to an adhesive treatment in which the core wire is immersed in a first treating agent containing an epoxy compound and a blocked isocyanate compound and heated, and then immersed in a second treating agent containing a silane coupling agent and heated.

15. A method for manufacturing a power transmission belt having a core wire embedded in an elastomer belt body, comprising the steps of: A core wire bonding process is provided for bonding the core wire, The core wire bonding process includes: a first treatment step of immersing the core wire in a first treatment agent containing an epoxy compound and a blocked isocyanate compound and heating the core wire; a second treatment step of immersing the core wire in a second treatment agent containing a silane coupling agent and heating the core wire after the first treatment step; A method for producing a power transmission belt comprising the steps of:

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