WO2010047121A1

WO2010047121A1 - Power transmission belt

Info

Publication number: WO2010047121A1
Application number: PCT/JP2009/005566
Authority: WO
Inventors: 草野隆行; 中本雄二; 中嶋栄二郎
Original assignee: バンドー化学株式会社
Priority date: 2008-10-23
Filing date: 2009-10-22
Publication date: 2010-04-29
Also published as: CN102177363B; CN102748428B; JPWO2010047121A1; DE112009002487B4; CN102748428A; CN102177363A; JP5432916B2; DE112009002487T5

Abstract

A power transmission belt (10), wherein the power transmission belt comprises a belt body (11) consisting of a rubber composite and wherein that portion of the belt body (11) which makes contact with a pulley is covered with reinforcing cloth (13). The reinforcing cloth (13) is provided with a reinforcing cloth body (14), an RFL coating (15) provided to cover the surface of threads constituting the reinforcing cloth body (14), an impregnated rubber layer (16) provided between the threads constituting the reinforcing cloth body (14), the surface of which is covered with the RFL coating (15), and a surface rubber layer (18) provided to cover that side of the reinforcing cloth body (14) which is exposed at the surface of the belt. The surface rubber layer (18) contains more amount of a wear resistant material relative to 100 parts by mass of raw material rubber than the impregnated rubber layer (16).

Description

Transmission belt

The present invention relates to a transmission belt.

In order to perform the adhesion treatment of the reinforcing cloth provided on the surface of the belt body, an adhesion treatment agent in which an abrasion resistant material such as a fluororesin is dispersed is widely used. When the pulley contact part of the reinforcing fabric is treated with an adhesive treatment compounded with an abrasion resistant material, the friction coefficient of the pulley contact part is maintained at a low state to obtain good wear resistance, while reinforcing There is a possibility that the adhesiveness between the cloth and the belt main body is deteriorated.

In Patent Document 1, in a toothed belt, an RFL adhesion treatment is performed while leaving a gap portion on the surface of the tooth cloth, and then a large amount of a wear-resistant composite material containing a friction modifying component on one surface of the tooth cloth. It is described that the dispersed rubber paste is coated, and the other surface of the tooth cloth is coated with a rubber paste that does not contain an abrasion-resistant composite material.

Patent Document 2 discloses that a toothed belt is subjected to an RFL adhesion treatment and an impregnation treatment with glue rubber in which a large amount of fluororesin is dispersed on the filament surface in the tooth cloth, and the fluororesin is passed through the RFL adhesive component. In other words, it is described that it is dispersed in a large amount at a position very close to the fiber surface.

In Patent Document 3 and Patent Document 4, in the transmission belt, a first treatment in which an RFL treatment liquid in which a powdered antifriction material containing fluororesin powder is dispersed in a fiber material covering the surface of the transmission belt is impregnated, rubber The second treatment for impregnating the paste and the third treatment for impregnating the rubber paste in which the powdered antifriction material containing the fluororesin powder is dispersed are applied, whereby a large amount of the fluororesin powder is passed through the RFL component to the fiber material. It is described that it converges on or near the surface.

JP-T 2002-542078 JP 2000-310293 A Japanese Patent Laid-Open No. 2001-40582 JP 2001-38819 A

The present invention is a transmission belt in which a reinforcing cloth is provided on a portion of the belt main body that comes into contact with a pulley, and can maintain excellent wear resistance even when the belt runs for a long time. The object is to obtain excellent adhesion to the body.

The power transmission belt of the present invention is a belt body formed of a rubber composition that is in contact with a pulley and is coated with a reinforcing cloth.
The reinforcing cloth is provided between the reinforcing cloth main body, the RFL coating provided to cover the surface of the constituent yarn of the reinforcing cloth main body, and the constituent yarn of the reinforcing cloth main body surface-coated with the RFL coating. An impregnated rubber layer, and a surface rubber layer provided so as to cover the belt surface exposed side of the reinforcing fabric body,
The surface rubber layer is characterized in that the content of the wear-resistant material with respect to 100 parts by mass of the raw rubber is larger than that of the impregnated rubber layer.

The wear-resistant material is preferably polytetrafluoroethylene powder.

The impregnated rubber layer preferably contains an isocyanate compound.

In the transmission belt of the present invention, the impregnated rubber layer includes 5 to 100 parts by mass of the wear resistant material with respect to 100 parts by mass of the raw rubber, and the surface rubber layer includes the wear resistant material of the raw rubber. It is preferably contained in an amount of 20 to 230 parts by mass per 100 parts by mass.

In the transmission belt of the present invention, the belt body may be a toothed belt body.

According to the above configuration, the reinforcing cloth provided to cover the surface of the belt main body includes the reinforcing cloth main body, the RFL film provided to cover the surface of the constituent yarn of the reinforcing cloth main body, and the RFL film. An impregnated rubber layer provided between constituent yarns of the reinforcing cloth body surface-coated with a surface rubber layer provided so as to cover the belt surface exposed side of the reinforcing cloth body, and The surface rubber layer has a higher wear resistance material content relative to 100 parts by mass of the raw rubber than the impregnated rubber layer, so that it can maintain excellent wear resistance even for long-time belt running, Excellent adhesion between the reinforcing cloth and the belt body can be obtained.

It is a perspective view of the toothed belt of this embodiment. It is a principal part enlarged view of the cross section of a toothed belt. It is a pulley layout of the belt running test machine in the test evaluation.

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

(Toothed belt)
FIG. 1 shows a toothed belt 10 according to the present embodiment. The toothed belt 10 is suitably used for high load applications such as OHC driving applications for automobiles.

The toothed belt 10 has a rubber toothed belt main body 11, and the pulley contact side surface thereof is covered with a reinforcing cloth 13.

The toothed belt body 11 is formed of a rubber composition in which an uncrosslinked rubber composition obtained by blending a raw material rubber with a compounding agent and kneaded is heated and pressurized to be crosslinked with the crosslinking agent. Examples of the raw rubber of the rubber composition constituting the toothed belt main body 11 include ethylene-α-olefin elastomers such as ethylene / propylene rubber (EPR) and ethylene propylene diene monomer rubber (EPDM), chloroprene rubber (CR), Examples thereof include chlorosulfonated polyethylene rubber (CSM) and hydrogenated acrylonitrile rubber (H-NBR). The raw rubber may be composed of a single kind or a plurality of kinds. Examples of the compounding agent include cross-linking agents (for example, sulfur and organic peroxides), anti-aging agents, processing aids, plasticizers, fillers, reinforcing materials such as carbon black, silica, and short fibers. About each compounding agent, even if comprised by single type and may be comprised by multiple types, either may be sufficient.

The toothed belt main body 11 has a back surface portion 11b on the outer peripheral side, and tooth portions 11a on the inner peripheral side integrally with the back surface portion 11b at regular intervals in the belt length direction.

The back part 11b is formed in a horizontally long flat band shape. On the inner peripheral side of the back surface portion 11b, the core wire 12 is embedded so as to form a spiral having a pitch in the belt width direction.

The core wire 12 is composed of a twisted yarn or braid of a long fiber material. It is preferable that the strand 12 of twisted yarn is provided so that a pair of S twist and Z twist may form a double helix. Examples of the fiber material constituting the core wire 12 include glass fiber, aramid fiber, polyparaphenylene benzobisoxazole (PBO) fiber, and metal fiber. The core 12 is subjected to an adhesive treatment for heating after being immersed in an RFL aqueous solution before molding and / or an adhesive treatment for drying after being immersed in rubber paste in order to impart adhesion to the toothed belt body 11. It is.

The tooth portion 11a may be formed as a trapezoidal tooth having a trapezoidal shape in a side view, or may be formed into a semicircular round tooth, or may be formed in another shape. The tooth portion 11a may have a configuration provided so as to extend in the belt width direction, or may have a helical tooth configuration provided so as to extend in a direction inclined with respect to the belt width direction. Also good.

The toothed belt body 11 has a tooth portion 11 a surface covered with a reinforcing cloth 13. FIG. 2 shows a cross section of the reinforcing cloth 13.

The reinforcing cloth 13 includes a reinforcing cloth main body 14, an RFL coating 15, an impregnated rubber layer 16, an adhesive rubber layer 17, and a surface rubber layer 18 provided by performing a predetermined bonding process on the reinforcing cloth main body 14. , With. The reinforcing cloth 13 has a thickness of 0.8 to 1.8 mm, for example.

The reinforcing fabric body 14 is a component yarn made of nylon fiber such as 6,6-nylon, 4,6-nylon, 6-nylon, polyester fiber, aramid fiber, polyparaphenylene benzobisoxazole (PBO) fiber, or the like. It is composed of a woven fabric such as plain weave, twill weave, satin weave, knitted fabric, or non-woven fabric. The reinforcing fabric body 14 preferably has extensibility in the belt length direction from the viewpoint of tooth portion formation.

The RFL coating 15 is provided so as to cover the entire surface of the constituent yarn of the reinforcing fabric body 14. The RFL coating 15 is formed by immersing the reinforcing fabric body 14 in the RFL aqueous solution and then heating and drying. From the viewpoint of adhesion to the reinforcing fabric body 14, the RFL coating 15 preferably does not contain an abrasion resistant material.

The impregnated rubber layer 16 is provided so as to penetrate between the constituent yarns of the reinforcing cloth body 14 whose surface is coated with the RFL coating 15. As a result, the constituent yarn surface of the reinforcing fabric body 14 is covered with the impregnated rubber layer 16 via the RFL coating 15. The impregnated rubber layer 16 is formed by immersing and drying the reinforcing cloth body 14 having the surface coated with the RFL coating 15 in the rubber paste for the impregnated rubber layer.

Examples of the rubber composition forming the impregnated rubber layer 16 include ethylene-α-olefin elastomers such as ethylene / propylene rubber (EPR) and ethylene propylene diene monomer rubber (EPDM), chloroprene rubber (CR), and chlorosulfonated polyethylene rubber. (CSM), hydrogenated acrylonitrile rubber (H-NBR) or the like is used as a raw rubber, and various compounding agents are blended in the raw rubber.

The compounding agent blended in the rubber composition of the impregnated rubber layer 16 includes at least the wear resistant material P. Examples of the wear resistant material P include polytetrafluoroethylene (PTFE), ultrahigh molecular weight polyethylene (UHMWPE), high density polyethylene (HDPE), ethylene-tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene par Fluoro (alkyl-vinyl ether) copolymer (PFA), polyvinylidene fluoride (PVDF) and the like. Of these, polytetrafluoroethylene (PTFE) is preferable from the viewpoint of wear resistance. The wear-resistant material P is preferably blended in an amount of 5 to 100 parts by mass, more preferably 40 to 80 parts by mass, and 60 to 70 parts by mass with respect to 100 parts by mass of the raw rubber of the rubber composition. More preferably it is. From the viewpoint of dispersibility in the impregnated rubber layer 16, the wear resistant material P is preferably powdery, and has a particle size of 0.5 to 50 μm, for example.

Further, the compounding agent compounded in the rubber composition of the impregnated rubber layer 16 preferably contains an isocyanate compound from the viewpoint of adhesiveness. Examples of the isocyanate compound include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), and the like. The isocyanate compound is preferably blended in an amount of 5 to 40 parts by weight, more preferably 10 to 20 parts by weight, based on 100 parts by weight of the raw rubber of the rubber paste for the impregnated rubber layer.

The adhesive rubber layer 17 is formed on the surface of the reinforcing fabric body 14 on which the RFL coating 15 and the impregnated rubber layer 16 are formed on the belt body adhesion side. The adhesive rubber layer 17 has a thickness of 50 to 300 μm, for example. The adhesive rubber layer 17 is formed, for example, by applying rubber glue for an adhesive rubber layer to the reinforcing cloth body 14 and drying it.

Examples of the rubber composition for forming the adhesive rubber layer 17 include ethylene-α-olefin elastomers such as ethylene / propylene rubber (EPR) and ethylene propylene diene monomer rubber (EPDM), chloroprene rubber (CR), and chlorosulfonated polyethylene rubber. (CSM), hydrogenated acrylonitrile rubber (H-NBR) or the like is used as a raw rubber, and various compounding agents are blended in the raw rubber. It is preferable that the compounding agent blended in the rubber composition forming the adhesive rubber layer 17 does not contain an abrasion-resistant material, whereby excellent adhesion between the toothed belt body 11 and the reinforcing cloth 13 is obtained. can get.

The surface rubber layer 18 is provided so as to cover the surface of the reinforcing fabric body 14 on which the RFL coating 15 and the impregnated rubber layer 16 are formed, on the belt surface exposed side. The surface rubber layer 18 has a thickness of 50 to 500 μm, for example. The surface rubber layer 18 is formed, for example, by applying a rubber paste for the surface rubber layer to the reinforcing fabric body 14 and drying it.

The rubber composition for forming the surface rubber layer 18 is, for example, an ethylene-α-olefin elastomer such as ethylene / propylene rubber (EPR) or ethylene propylene diene monomer rubber (EPDM), chloroprene rubber (CR), chlorosulfonated polyethylene rubber. (CSM), hydrogenated acrylonitrile rubber (H-NBR) or the like is used as a raw rubber, and various compounding agents are blended in the raw rubber.

The compounding agent blended in the rubber composition of the surface rubber layer 18 includes at least the wear resistant material P. Examples of the wear resistant material P include polytetrafluoroethylene (PTFE), ethylene / tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene / perfluoro (alkyl-vinyl ether) copolymer (PFA), and polyfluoride. And vinylidene chloride (PVDF). Of these, polytetrafluoroethylene (PTFE) is preferable from the viewpoint of wear resistance. The wear-resistant material P is preferably blended in an amount of 20 to 230 parts by weight, more preferably 70 to 120 parts by weight, and more preferably 80 to 100 parts by weight with respect to 100 parts by weight of the raw rubber of the rubber composition. More preferably it is. In the rubber composition forming the surface rubber layer 18, the content of the wear-resistant material P with respect to 100 parts by mass of the raw rubber is larger than that of the impregnated rubber layer 16, and thereby the surface exposed portion of the toothed belt 10, that is, The wear resistance at the pulley contact portion is enhanced. The wear-resistant material P is preferably in the form of powder from the viewpoint of dispersibility in the surface rubber layer 18, and has a particle size of 0.5 to 50 μm, for example.

According to the reinforcing cloth 13 configured as described above, the impregnated rubber layer 16 includes the wear-resistant material P, and the surface of the constituent yarn of the reinforcing cloth main body 14 is covered with the impregnated rubber layer 16 via the RFL coating 15. As described above, since the impregnated rubber layer 16 is formed between the constituent yarns of the reinforcing cloth main body 14, the surface of the constituent yarns of the reinforcing cloth main body 14 is subjected to wear resistance via the RFL coating 15. The material P is present, and excellent wear resistance is obtained on the surface of the reinforcing fabric body 14. In other words, even if the belt surface exposed portion of the reinforcing fabric 13, that is, the pulley contact portion is worn by running the belt for a long time, the state where the wear resistant material P exists on the surface of the reinforcing fabric body 14 is maintained. As a result, high wear resistance can be maintained for a long time.

Further, since the rubber composition of the surface rubber layer 18 has a higher content of the wear resistant material P with respect to 100 parts by mass of the raw rubber than the impregnated rubber layer 16, the wear resistance at the pulley contact portion of the reinforcing fabric 13 is further improved. Can be obtained. On the other hand, since the adhesive rubber layer not including the wear-resistant material is provided on the surface of the reinforcing fabric body 14 on the belt body 11 adhesion side, the adhesion to the belt body 11 is also improved.

Although not shown in the drawings, a back-side reinforcing cloth may be provided on the surface of the back surface portion 11b of the toothed belt main body 11. The back side reinforcing fabric is made of a fiber material such as nylon fiber such as 6,6-nylon, 4,6-nylon or 6-nylon, polyester fiber, aramid fiber, polyparaphenylene benzobisoxazole (PBO) fiber, for example. The woven fabric such as plain weave, twill weave, satin weave, knitted fabric, or non-woven fabric is used. The back side reinforcing cloth is dried by applying rubber paste to the surface on the side of the toothed belt body 11 and / or an adhesion treatment in which it is immersed and heated in an RFL aqueous solution in order to impart adhesion to the toothed belt body 11. Adhesive treatment is applied.

According to the toothed belt 10 having the above-described configuration, it is possible to maintain excellent wear resistance even for a long time running while the toothed belt body 11 and the reinforcing cloth 13 are well bonded. It becomes.

(Manufacturing method of toothed belt)
Next, a method for manufacturing the toothed belt 10 will be described. This manufacturing method is roughly divided into a reinforcing cloth preparation step, an uncrosslinked rubber sheet / twist yarn preparation step, and a toothed belt molding step.

<Preparation of reinforcing fabric>
First, the reinforcement cloth 13 is prepared by forming the RFL coating 15, the impregnation rubber layer 16, the adhesion rubber layer 17, and the surface rubber layer 18 on the reinforcement cloth main body 14 by performing an adhesion process described below. Specifically, the adhesion treatment is performed by RFL aqueous solution impregnation treatment, rubber paste impregnation treatment, and rubber paste application treatment.

-RFL aqueous solution impregnation-
The RFL aqueous solution impregnation treatment is a treatment in which the reinforcing fabric body 14 is immersed in the RFL aqueous solution and then heated and dried. As a result, the constituent yarns of the reinforcing fabric body 14 are surface-coated with the RFL coating 15.

The RFL aqueous solution is a mixed liquid in which an initial condensate of resorcin and formalin is mixed with latex such as chloroprene rubber latex (CR) and hydrogenated acrylonitrile rubber latex (X-NBR). The solid content of the RFL aqueous solution is, for example, 5 to 25% by mass. The molar ratio of resorcin (R) to formalin (F) is, for example, R / F = 1 / 0.8 to 1 / 2.0. The mass ratio of the initial condensate (RF) of resorcin and formalin to latex (L) is, for example, RF / L = 1/5 to 1/20. When the RFL aqueous solution is attached to the reinforcing fabric body 14 and then dried by heating, the moisture of the RFL aqueous solution scatters and the condensation reaction between resorcin and formalin proceeds, and the RFL coating 15 is formed on the surface of the reinforcing fabric body 14. .

After the reinforcing cloth main body 14 is immersed in the RFL aqueous solution, the reinforcing cloth main body 14 is impregnated with the RFL aqueous solution by squeezing with a squeeze roll. The drying temperature of the reinforcing fabric body 14 is, for example, 140 to 180 ° C., and the drying time is, for example, 3 to 5 minutes. The number of times of processing may be one time or a plurality of times. For example, the RFL coating 15 has an adhesion amount of 5 to 40 parts by mass with respect to 100 parts by mass of the mass of the reinforcing fabric body 14. The adhesion amount of the RFL coating 15 can be controlled by the number of dipping treatments of the reinforcing fabric body 14 in the RFL aqueous solution and the degree of drawing.

-Rubber paste impregnation treatment-
In the rubber paste impregnation treatment, the reinforcing cloth body 14 having the RFL coating 15 formed on the surface is immersed in the rubber paste for the impregnation rubber layer, then squeezed with a squeeze roll, and the solvent is dried and scattered to form the impregnation rubber layer 16. It is.

The rubber paste for the impregnated rubber layer is made by blending various compounding agents with raw rubber such as ethylene propylene diene monomer rubber (EPDM), chloroprene rubber (CR), hydrogenated acrylonitrile rubber (H-NBR), acrylonitrile rubber (NBR). The kneaded mixture is dissolved in a solvent such as toluene or methyl ethyl ketone (MEK). The rubber paste for the impregnated rubber layer has, for example, a solid content concentration of 5 to 30% by mass.

The drying temperature of the reinforcing fabric body 14 is, for example, 60 to 120 ° C., and the drying time is, for example, 3 to 10 minutes. The amount of the impregnated rubber layer 16 attached can be controlled by the number of dipping processes of the reinforcing fabric body 14 in the impregnated rubber layer 16 and the degree of drawing.

By this rubber paste impregnation treatment, the impregnated rubber layer 16 is formed between the constituent yarns of the reinforcing cloth main body 14, so that the surface of the constituent yarns of the reinforcing cloth main body 14 is abrasion-resistant with the RFL coating 15 interposed therebetween. Material P can be present.

-Rubber paste application process-
The rubber paste coating treatment is performed after the adhesive rubber layer rubber paste is applied to one surface of the reinforcing cloth body 14 on which the RFL coating 15 and the impregnated rubber layer 16 are formed, and the surface rubber layer rubber paste is applied to the other surface. This is a process of drying and scattering the solvent. As a result, the adhesive rubber layer 17 is formed on one surface of the reinforcing fabric body 14, and the surface rubber layer 18 is formed on the other surface.

This rubber paste application process will be specifically described. First, a rubber paste for an adhesive rubber layer dissolved in a solvent such as toluene or methyl ethyl ketone (MEK) is applied to one surface of the reinforcing fabric body 14, and then dried for 3 to 10 minutes at an ambient temperature of 60 to 120 ° C., for example. Let The number of times of applying the adhesive rubber layer rubber paste may be one or may be repeated a plurality of times. The adhesive rubber layer 17 thus formed has a thickness of 50 to 300 μm, for example.

The rubber paste for the adhesive rubber layer is prepared by blending various compounding ingredients in raw rubber and kneading them in a solvent such as toluene or methyl ethyl ketone (MEK). The rubber paste for the adhesive rubber layer has a solid content concentration of 20 to 45% by mass, for example.

Subsequently, similarly to the application of the adhesive rubber layer rubber paste, the surface rubber layer rubber paste is applied to the surface of the reinforcing fabric body 14 opposite to the surface to which the adhesive rubber layer rubber paste is applied. Dry at ambient temperature of ~ 120 ° C for 3-10 minutes. The formed surface rubber layer 18 has a thickness of 50 to 500 μm, for example.

The rubber paste for the surface rubber layer is obtained by mixing and kneading various compounding agents including the wear-resistant material P in raw rubber and dissolving them in a solvent such as toluene or methyl ethyl ketone (MEK). The rubber paste for the surface rubber layer has, for example, a solid content concentration of 20 to 45% by mass.

Here, the adhesive rubber layer 17 is formed before the surface rubber layer 18 is formed, but the adhesive rubber layer 17 may be formed after the surface rubber layer 18 is formed. May be formed.

Further, the adhesive rubber layer 17 and the surface rubber layer 18 may be formed by glueing, calendering, lapping, or laminating.

Through the above steps, the reinforcing cloth body 14 is subjected to an adhesion treatment to prepare the reinforcing cloth 13.

<Preparation of uncrosslinked rubber sheet and twisted yarn>
An uncrosslinked rubber sheet for forming the toothed belt body 11 is prepared by a known method.

Also, an adhesive treatment that is heated after being immersed in an RFL aqueous solution in a twisted yarn for forming the core wire 12 and / or an adhesive treatment that is dried after being immersed in rubber paste is performed.

<Formation of toothed belt>
An uncrosslinked rubber sheet serving as a toothed belt main body 11, a twisted yarn serving as a core wire 12, and a reinforcing cloth 13 prepared by performing the above-described adhesion treatment are prepared, and the toothed belt 10 is formed by a known method. In this molding operation, a cylindrical mold and a vulcanizing pot for fitting it are used. On the outer peripheral surface of the cylindrical mold, concave grooves for forming the tooth portions 11a of the toothed belt 10 are formed so as to extend in the axial direction and be arranged at equal intervals in the circumferential direction.

First, the cylindrical mold is covered with the reinforcing cloth 13. At this time, the surface of the reinforcing cloth 13 to which the surface rubber layer 18 is applied is in contact with the mold and the extending direction of the reinforcing cloth 13 coincides with the circumferential direction (belt length direction) of the cylindrical mold. Wrap. Then, a twisted yarn is wound spirally on the reinforcing cloth 13 on the cylindrical mold, and an uncrosslinked rubber sheet is further wound thereon.

Subsequently, a cylindrical mold on which the reinforcing cloth 13, the twisted yarn and the uncrosslinked rubber sheet are set is placed in a vulcanizing pot and heated and pressurized. At this time, the rubber flows to the cylindrical mold side by heating and pressurization, and particularly at the concave groove portion, the reinforcing cloth 13 is stretched along the concave groove surface by pressing the rubber to form belt teeth. In addition, the toothed belt main body 11 is formed, and a cylindrical slab in which the toothed belt main body 11, the core wire 12, and the reinforcing cloth 13 are integrated is formed. Then, the adhesive rubber layer 17 and the surface rubber layer 18 formed on the surface of the reinforcing cloth 13 are diffused on the surface of the reinforcing cloth main body 14, and the adhesive rubber layer 17 is attached to the belt main body bonding side of the reinforcing cloth 13. A surface rubber layer 18 is positioned on each of the 10 pulley contact portions.

Next, after cooling the slab, the cylindrical mold is taken out from the vulcanizer and the slab is removed from the cylindrical mold.

Finally, after polishing the back surface of the slab to make the thickness uniform, the toothed belt 10 is obtained by cutting into a predetermined width.

In the present embodiment, the toothed belt has been described. However, the present invention is not particularly limited to this, and any transmission belt in which the belt body surface is covered with the reinforcing cloth 13 may be used.

Further, in this embodiment, the reinforcing cloth 13 subjected to the bonding treatment of the present invention is provided on the inner side of the belt. However, the present invention is not limited to this, and the above-mentioned bonding is applied to the back-side reinforcing cloth provided on the outer peripheral side of the belt. Processing may be performed.
[Test evaluation]
The test evaluation performed on the toothed belt will be described.

(Test evaluation belt)
The toothed belts of Examples 1 to 5 and Comparative Examples 1 to 5 were produced.

<Example 1>
-Preparation of reinforcing fabric-
A reinforcing cloth body was prepared by performing the following series of adhesion treatments in advance on a reinforcing cloth body made of 6,6-nylon (manufactured by Asahi Kasei Co., Ltd., trade name: Leona 66).

First, the reinforcing cloth main body was immersed in an RFL aqueous solution whose latex component is H-NBR and applied to a squeeze roll, followed by drying by heating to form an RFL coating on the surface of the reinforcing cloth main body. This RFL coating was 20 parts by mass with respect to 100 parts by mass of the reinforcing fabric body.

Next, the reinforcing cloth body having the RFL film formed on the surface was immersed in the rubber paste for the impregnated rubber layer, applied to a squeeze roll, and then dried to form an impregnated rubber layer. This rubber paste for the impregnated rubber layer is obtained by dissolving a kneading agent obtained by blending a cross-linking agent or the like with H-NBR (manufactured by Nippon Zeon Co., Ltd., trade name: Zetpol 2000) in a MEK solvent. 70 parts by mass of PTFE (manufactured by AGC, trade name: L1737, average particle size 7 μm) and 20 parts by weight of isocyanate compound (trade name: Chemlock 233X) by 100 parts by weight of the solid component of the paste It was what was done.

Subsequently, the rubber paste for the adhesive rubber layer is applied to one surface of the reinforcing cloth main body having the RFL film and the impregnated rubber layer formed on the surface, and the rubber paste for the surface rubber layer is applied to the other surface, and the adhesive rubber layer And a surface rubber layer were formed.

The rubber paste for the adhesive rubber layer was obtained by dissolving a kneaded mixture of a crosslinking agent and the like in H-NBR in a MEK solvent. The rubber paste for the adhesive rubber layer had a raw rubber concentration of 35% by mass. The formed adhesive rubber layer had a layer thickness of 150 μm.

The rubber paste for the surface rubber layer is obtained by mixing H-NBR with a crosslinking agent and kneading it and dissolving it in MEK solvent. 100 parts by weight of PTFE is added to 100 parts by weight of the solid component of the rubber paste. It was what was done. The rubber paste for the surface rubber layer had a raw rubber concentration of 35% by mass. The formed surface rubber layer had a layer thickness of 200 μm.

-Toothed belt molding-
A toothed belt body is formed of a rubber composition formed by mixing and kneading a cross-linking agent using H-NBR as a raw material rubber, and a high-strength glass twisted yarn (manufactured by Nippon Sheet Glass Co., Ltd., filament diameter: 7 μm, number of strands: 3 Using the number of ropes 11) as a core wire and using the reinforcing fabric prepared above, a toothed belt was produced and used as Example 1. This toothed belt had a belt width of 10 mm, a belt length of 840 mm, a belt tooth pitch of 8 mm, and 105 teeth.

<Example 2>
-Preparation of reinforcing fabric-
A reinforcing cloth was prepared by carrying out the same adhesive treatment as in Example 1 except that the blending amount of PTFE was 5 parts by mass with respect to 100 parts by mass of the solid component of the rubber paste of the rubber paste for the impregnated rubber layer.

-Toothed belt molding-
A toothed belt having the same configuration as that of Example 1 was produced except that a reinforcing cloth prepared by performing the above-described adhesion treatment was used.

<Example 3>
-Preparation of reinforcing fabric-
A reinforcing cloth was prepared by performing the same adhesive treatment as in Example 1 except that the blending amount of PTFE with respect to 100 parts by mass of the raw rubber of the rubber paste for the surface rubber layer was 230 parts by mass.

-Toothed belt molding-
A toothed belt having the same configuration as in Example 1 was produced except that the reinforcing cloth prepared by performing the above-described adhesion treatment was used, and this was designated as Example 3.

<Example 4>
-Adjustment of reinforcing fabric-
The blending amount of PTFE with respect to 100 parts by weight of the solid component of the rubber paste of the rubber paste for the impregnated rubber layer was 50 parts by weight, and the blending amount of PTFE with respect to 100 parts by weight of the raw rubber of the rubber paste for the surface rubber layer was 70 parts by weight. A reinforcing fabric was prepared by performing the same adhesive treatment as in Example 1 except for.

-Toothed belt molding-
A toothed belt having the same configuration as that of Example 1 was prepared except that the reinforcing cloth prepared by performing the above-described adhesion treatment was used.

<Example 5>
-Adjustment of reinforcing fabric-
A reinforcing cloth was prepared by carrying out the same adhesive treatment as in Example 4 except that the blending amount of PTFE was 60 parts by mass with respect to 100 parts by mass of the solid component of the rubber paste of the rubber paste for the impregnated rubber layer.

<Comparative Example 1>
-Preparation of reinforcing fabric-
A reinforcing cloth was prepared by performing the following series of adhesion treatments in advance on a reinforcing cloth body made of 6,6-nylon.

First, as in Example 1, an RFL film was formed on the surface of the reinforcing cloth body.

Next, the reinforcing cloth body having the RFL film formed on the surface was dipped in the rubber paste for the impregnated rubber layer and dried to form an impregnated rubber layer. This rubber paste for impregnated rubber layer is obtained by dissolving a kneaded mixture of H-NBR and a crosslinking agent in MEK solvent, and blending PTFE with 100 parts by mass of the solid component of the rubber paste. The amount was 1 part by mass, and the compounding amount of the isocyanate compound was 20 parts by mass.

Subsequently, rubber paste was applied to the surface to be bonded to the teeth of the reinforcing fabric body to form a rubber composition layer. This rubber composition layer corresponds to the adhesive rubber layer in the present invention. This rubber paste had the same composition as the rubber paste for the adhesive rubber layer of Example 1.

-Toothed belt molding-
A toothed belt having the same configuration as in Example 1 was prepared except that the reinforcing cloth prepared by performing the above-described adhesion treatment was used, and this was designated as Comparative Example 1.

<Comparative example 2>
-Preparation of reinforcing fabric-
A reinforcing cloth was prepared by performing the same adhesion treatment as in Comparative Example 1 except that the isocyanate compound was not blended in the rubber paste for the impregnated rubber layer on the reinforcing cloth body. The rubber paste for the impregnated rubber layer had a raw rubber concentration of 15% by mass.

-Toothed belt molding-
A toothed belt having the same configuration as in Example 1 was prepared except that the reinforcing cloth prepared by performing the above-described adhesion treatment was used, and this was designated as Comparative Example 2.

<Comparative Example 3>
-Preparation of reinforcing fabric-
Comparative Example 1 except that the amount of PTFE is 70 parts by weight and the amount of isocyanate compound is 20 parts by weight with respect to 100 parts by weight of the solid component of the rubber paste of the rubber paste for the impregnated rubber layer on the reinforcing cloth body. The same adhesive treatment was performed to prepare a reinforcing fabric.

-Toothed belt molding-
A toothed belt having the same configuration as that of Example 1 was prepared except that the reinforcing cloth prepared by performing the above-described adhesion treatment was used, and this was designated as Comparative Example 3.

<Comparative example 4>
-Preparation of reinforcing fabric-
The blending amount of PTFE with respect to 100 parts by weight of the solid component of the rubber paste of the rubber paste for the impregnated rubber layer is 100 parts by weight, the blending amount of the isocyanate compound is 0 part by weight, and the raw rubber of the rubber paste for the surface rubber layer A reinforcing cloth was prepared by performing the same adhesive treatment as in Example 1 except that the blending amount of PTFE with respect to 100 parts by mass was 70 parts by mass.

-Toothed belt molding-
A toothed belt having the same configuration as that of Example 1 was prepared except that the reinforcing cloth prepared by performing the above-described adhesion treatment was used, and this was designated as Comparative Example 4.

<Comparative Example 5>
-Preparation of reinforcing fabric-
A reinforcing cloth was prepared by carrying out the same adhesive treatment as in Comparative Example 4 except that the blending amount of PTFE was 80 parts by mass with respect to 100 parts by mass of the solid component of the rubber paste of the rubber paste for the impregnated rubber layer.

-Toothed belt molding-
A toothed belt having the same configuration as that of Example 1 was prepared except that the reinforcing cloth prepared by performing the above-described adhesion treatment was used, and this was designated as Comparative Example 5.

(Test evaluation method)
<Table load durability test>
FIG. 3 shows a pulley layout of the belt running test machine 30 in the bench load endurance test.

This belt running test machine 30 includes a large-diameter driven toothed pulley 31 (42 teeth), a small-diameter driving toothed pulley 32 (21 teeth) provided on the right side thereof, a driven toothed pulley 31 and A flat pulley (idler pulley) 33 having a pulley diameter of 52 mm is provided in the middle of the drive toothed pulley 32 and slightly diagonally below the driven toothed pulley 31. The belt is positioned so as to be horizontal from the driven toothed pulley 31 to the driving toothed pulley 32.

The toothed belts of Examples 1 to 5 and Comparative Examples 1 to 5 are wound so that the toothed portion is engaged with the driven toothed pulley 31 and the driving toothed pulley 32 and the flat pulley 33 is in contact with the back surface of the belt. After that, a load torque of 29.4 Nm is applied to the driven toothed pulley 31 and a dead weight is applied to the driving toothed pulley 32 so that a belt tension of 216 N is applied. The attached pulley 32 was rotated clockwise at a rotational speed of 6000 rpm to run the belt.

(Test evaluation results)
The results of the test evaluation are shown in Tables 1 and 2.

According to these results, Example 1 in which the surface rubber layer containing more wear-resistant material than the impregnated rubber layer was provided, and Comparative Examples 1 to 3 in which the surface rubber layer was not provided, By comparison, it can be seen that the former travels significantly longer.

Examples 1 to 5 in which the compounding amount of the wear-resistant material of the surface rubber layer is larger than that of the impregnated rubber layer, Comparative Examples 4 and 5 in which the compounding amount of the wear-resistant material of the surface rubber layer is smaller than that of the impregnated rubber layer, Compared to the latter, the belt running time is short due to peeling of the tooth cloth, so the amount of wear-resistant material in the surface rubber layer is greater than that of the impregnated rubber layer to increase the adhesion between the reinforcing cloth and the belt body. Can be seen to improve.

Comparing Comparative Examples 1 to 3 in which the surface rubber layer is not formed, Comparative Example 3 in which the wear-resistant material is blended in the impregnated rubber layer has a slightly longer running time in the bench load durability test. I understand.

As described above, the present invention is useful for a transmission belt in which a portion of the belt body that contacts the pulley is covered with a reinforcing cloth.

10 Toothed belt (power transmission belt)
11 Toothed belt body (belt body)
13 Reinforcing cloth 14 Reinforcing cloth body 15 RFL coating 16 Impregnated rubber layer 18 Surface rubber layer

Claims

A portion of the belt main body formed of the rubber composition that contacts the pulley is a transmission belt covered with a reinforcing cloth,
The reinforcing cloth is provided between the reinforcing cloth main body, the RFL coating provided to cover the surface of the constituent yarn of the reinforcing cloth main body, and the constituent yarn of the reinforcing cloth main body surface-coated with the RFL coating. An impregnated rubber layer, and a surface rubber layer provided so as to cover the belt surface exposed side of the reinforcing fabric body,
The power transmission belt according to claim 1, wherein the surface rubber layer has a higher content of an abrasion-resistant material relative to 100 parts by mass of the raw rubber than the impregnated rubber layer.
The power transmission belt according to claim 1,
A power transmission belt, wherein the wear-resistant material is polytetrafluoroethylene powder.
The power transmission belt according to claim 1 or 2,
The transmission belt, wherein the impregnated rubber layer contains an isocyanate compound.
The transmission belt according to any one of claims 1 to 3,
The impregnated rubber layer contains 5 to 100 parts by mass of the wear-resistant material with respect to 100 parts by mass of the raw rubber, and the surface rubber layer has 20 parts of the wear-resistant material with respect to 100 parts by mass of the raw rubber. A transmission belt characterized by containing ~ 230 parts by mass.
In the transmission belt according to any one of claims 1 to 4,
The transmission belt according to claim 1, wherein the belt body is a toothed belt body.