JP6157876B2 - Transmission belt - Google Patents

Description

  The present invention relates to a transmission belt in which a pulley contact surface of a belt body is covered with a reinforcing cloth.

  Various techniques for improving the wear resistance of the pulley contact surface of the toothed belt have been proposed. For example, there is a method of improving the wear resistance by increasing the basis weight of the reinforcing cloth covering the tooth side surface (generally, using a thicker reinforcing cloth). Patent Document 1 discloses a toothed belt in which a wear modifying material is included in a reinforcing cloth.

Japanese Patent No. 3547403

  However, increasing the basis weight of the reinforcing cloth causes a problem of increasing the cost and reducing the durability life.

  Further, when the wear modifying material is infiltrated into the gap between the yarns of the reinforcing cloth provided on the power surface of the transmission belt as in Reference 1, the amount of the wear modifying material existing on the surface of the transmission belt is The wear due to the contact between the pulley and the yarn of the reinforcing cloth is reduced.

  Furthermore, it is conceivable that a large amount of wear modifying material is blended and a lot of wear modifying material is also present on the surface of the reinforcing cloth. However, in this case, the reinforcing property is lowered and the wear resistance is deteriorated. To do.

  In view of the above, an object of the present disclosure is to improve wear resistance, abnormal noise performance, and durability performance in a balanced manner while suppressing an increase in cost in a transmission belt.

  In order to achieve the above object, a transmission belt according to the present disclosure is a transmission belt having a belt main body formed of a rubber composition, and includes a wear modifier on at least a part of a surface portion of the belt main body. A surface layer is formed.

  According to such a transmission belt, the wear resistance can be improved by the wear modifier contained in the surface layer of the belt.

The surface layer includes a surface reinforcing cloth provided so as to cover the surface of the belt body, and the basis weight of the surface reinforcing cloth may be 10 g / m ² or more and 200 g / m ² or less.

  According to such a transmission belt, the belt can be reinforced by the surface reinforcing cloth and the wear resistance can be improved by the wear modifier. The basis weight of the surface reinforcing fabric used here is much smaller than before, and the gap between the fibers is wide. As a result, the wear modifier held at the portion of the belt surface that is not covered with the fibers of the surface reinforcing cloth acts, and the friction coefficient μ can be reduced.

  As described above, a surface layer containing an abrasion modifier is provided, and a surface reinforcing cloth is not used, or the surface weight is much smaller than the weight of the reinforcing cloth which has been conventionally considered necessary. An unexpectedly desirable effect was obtained by using the reinforcing cloth. In addition, even if a surface reinforcing cloth is not used or used, the amount of basis weight is small, which is effective in reducing costs.

  Further, the wear modifier may be dispersed in a thermoplastic resin, a thermosetting resin, or an elastomer. The wear modifier may be contained on the surface of the transmission belt in such a form.

The surface layer may be coated by wear modifiers.

  For example, an abrasion modifier dispersed in a solvent may be applied to the belt by spray coating.

  The reinforcing cloth may be coated, and the wear modifier may be contained in the coating material.

  The coating material may be rubber paste.

  Further, the transmission belt may be a toothed belt, and the surface layer may be formed on the surface of the tooth. Thus, the transmission belt of the present disclosure may be a toothed belt.

The basis weight of the surface reinforcing fabric may be 20 g / m ² or more and 80 g / m ² or less.

  When such a surface reinforcing cloth is used, a more remarkable effect can be obtained.

  The wear modifier may contain at least one of silicone oil, silicone resin, graphite, bentonite, molybdenum disulfide, nylon resin powder, methylsilicone rubber particles, fluororesin, and ultrahigh molecular weight polyethylene particles. good.

  Examples of wear modifiers can include these.

  A part of the rubber composition containing the wear modifier may protrude from the surface reinforcing cloth.

  As a result, the wear modifier acts more reliably at the contact portion between the belt and the pulley, so that the effect of the transmission belt of the present disclosure can be exhibited more reliably.

  According to the transmission belt of the present disclosure, it is possible to improve wear resistance, abnormal noise performance, and durability life in a well-balanced manner, and to reduce costs.

FIG. 1 is a perspective view illustrating an exemplary toothed belt of one embodiment of the present disclosure. FIG. 2 is a view showing the vicinity of the surface of the toothed belt of FIG. 1 on the pulley contact side. FIG. 3 is a diagram showing a pulley layout of a belt running tester used for an abrasion resistance test. FIG. 4 is a diagram showing a wear coefficient measuring apparatus. FIG. 5 is a diagram showing a pulley layout of a belt running test machine used for a noise test.

-Belt configuration-
Hereinafter, an exemplary toothed belt according to an embodiment of the present disclosure will be described with reference to the drawings.

  FIG. 1 shows a toothed belt 10 (transmission belt) of the present embodiment. The toothed belt 10 is used, for example, for general industrial uses such as an OHC drive application for automobiles, an injection molding machine application, and OA precision equipment.

  The toothed belt 10 according to the first embodiment includes a rubber endless toothed belt main body 11 constituting a belt outer shape. The toothed belt main body 11 has a configuration in which a laterally long flat belt-like back rubber portion 11b on the belt outer peripheral side and a plurality of tooth rubber portions 11a provided at regular intervals on the belt inner peripheral side are integrated. In the toothed belt main body 11, a core wire 12 is embedded on the inner peripheral side of the back rubber portion 11b so as to form a spiral extending in the belt length direction and having a pitch in the belt width direction. The toothed belt main body 11 has a belt inner peripheral surface having a tooth rubber portion 11 a, that is, a pulley contact surface covered with a reinforcing cloth 13. Further, the back rubber part 11b covered with the reinforcing cloth 13 on the belt inner peripheral side is configured as a tooth bottom part, and the tooth rubber part 11a covered with the reinforcing cloth 13 is configured as a tooth part.

  However, it is not essential to use the reinforcing cloth 13. When the reinforcing cloth 13 is not used, the tooth rubber part 11a itself is configured as a tooth part.

  The toothed belt body 11 is made of an uncrosslinked rubber composition obtained by blending a raw material rubber with a compounding agent and kneading, and is crosslinked by heating and pressurizing the rubber composition.

  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 include chlorosulfonated polyethylene rubber (CSM), hydrogenated acrylonitrile rubber (H-NBR), natural rubber (NR), styrene butadiene rubber (SBR), and nitrile rubber (NBR). The raw rubber may be composed of a single species, or may be composed of a blend of a plurality of species.

  Examples of compounding agents include reinforcing materials such as carbon black, silica, and short fibers, processing aids, anti-aging agents, vulcanization accelerators, crosslinking agents (for example, sulfur and organic peroxides), plasticizers, and fillers. Etc. Each compounding agent may be composed of a single species or a plurality of species.

  Moreover, the core wire 12 is comprised by what the adhesion | attachment process was performed to the thread | yarn main body.

  Examples of the fiber material of the yarn body constituting the core 12 include inorganic fibers such as glass fiber, carbon fiber, and metal fiber; organic fibers such as aramid fiber, polyester fiber, PBO fiber, nylon fiber, and polyketone fiber. It is done. The yarn body may be formed of a single type of fiber material or may be formed of a plurality of types of fiber material.

  Examples of the structure of the yarn main body include single-twisted yarn, plied yarn, rung-twisted yarn, twisted yarn such as core yarn, braided cord, and the like. The strand 12 of the twisted yarn may be provided so that a single yarn forms a spiral, or a pair of an S twisted yarn and a Z twisted yarn may be provided so as to form a double spiral.

  The adhesion treatment applied to the yarn body is, for example, a treatment in which the yarn body is immersed in a resorcin / formalin / latex aqueous solution (RFL aqueous solution) and then heated, and / or a treatment in which the yarn body is dried after being immersed in rubber paste.

  Next, FIG. 2 is a view schematically showing a surface portion of the toothed belt 10 covered with the reinforcing cloth 13.

As shown in FIG. 2, a reinforcing cloth 13 is at least partially embedded in the surface portion of the belt main body 11 made of a rubber composition. Reinforcing fabric 13, the basis weight (unit weight per area) is relatively small (in raw before performing the bonding process or the like described later, for example 10 to 200 g / ^{m 2,} more preferably 40 and 80 g ^{/ m} 2), Wide gap between warp and weft. Accordingly, a protruding portion 19 is formed in which a portion of the rubber constituting the belt body 11 protrudes from the reinforcing cloth 13 in the portion between the warp and the weft. The protruding portion 19 is made of a rubber composition that constitutes the belt main body 11, an adhesive rubber for bonding the reinforcing cloth 13 and the belt main body 11, a rubber related to the bonding treatment applied to the reinforcing cloth 13, and the like. As described above, the reinforcing cloth 13 covers the surface of the belt body 11, but there is a portion where the rubber is exposed in the gap between the threads constituting the reinforcing cloth 13. In addition, it does not exclude the presence of rubber that covers the yarn constituting the reinforcing cloth 13.

Conventionally, it has been considered essential to use a reinforcing cloth. Furthermore, conventionally, the basis weight of the reinforcing fabric in the toothed belt is about 100 to 700 g / m ² , and it has been considered that the reinforcing effect is insufficient when the basis weight is smaller than this.

  In addition, the reinforcing cloth 13 has a configuration in which the cloth body is subjected to an adhesion treatment, and has a thickness of, for example, 0.01 to 0.6 mm. The thickness of the reinforcing cloth in the conventional toothed belt is, for example, 0.6 to 1.6 mm, and the thickness of the reinforcing cloth 13 of the present disclosure is thinner than this.

  Examples of the fiber material of the cloth body constituting the reinforcing cloth 13 include, for example, natural fibers such as cotton and hemp, nylon fibers such as 6,6-nylon, 4,6-nylon or 6-nylon, polyester fibers, aramid fibers, Examples thereof include chemical fibers such as PBO fibers. The cloth body may be formed of a single type of fiber material or may be formed of a plurality of types of fiber material.

  Examples of the structure of the fabric body include woven fabrics such as plain weave, twill weave, and satin weave, knitted fabric, and non-woven fabric. In the woven fabric, the fabric body has a warp and weft yarn density of, for example, 10 to 500 pieces / 5 cm. The yarn constituting the fabric body of the woven fabric is a spun yarn or a filament yarn and has a thickness of, for example, 1 to 20000 dtex.

  In order to realize a desired basis weight, the thickness and density of the yarn as described above are good.

  The warps and wefts may be the same or different from each other in the yarn constituting the fabric body of the woven fabric. When the woven fabric body is used so that one of the warp and weft is in the belt length direction and the other is in the belt width direction, the woven fabric is stretchable in the belt length direction to obtain good tooth formation. It is desirable to have From this point, it is preferable that the yarn in the belt length direction is composed of, for example, a woolen yarn that has been subjected to false twisting to return twist after being heat-set by twisting.

When using the knitted fabric (knitted) or non-woven fabric as a fabric body, desirable fineness of the yarn is 1～500Dtex, desirable basis weight is 10 to 200 g / ^{m 2,} more preferably from 40 and 80 g / ^{m 2.}

  The adhesion treatment applied to the cloth body is, for example, a process of heating the cloth body after being immersed in an adhesive, a process of drying after being immersed in the adhesive, and a process of drying after coating the surface with the adhesive.

  The reinforcing cloth 13 is provided with an RFL layer and an impregnated rubber layer (not shown) so as to cover the surface of the yarn constituting the cloth body by the above-described adhesion treatment.

  The RFL layer is composed of a mixture of an RF resin component and a rubber component of L.

  Examples of L include vinylpyridine latex (VP), styrene butadiene rubber latex (SBR), chloroprene rubber latex (CR), nitrile butadiene rubber latex (NBR), hydrogenated acrylonitrile butadiene methacrylic acid terpolymer (X- NBR) latex, chlorosulfonated polyethylene rubber latex (CSM), 2,3-dichlorobutadiene polymer latex (2,3-DCB) and the like. L may be composed of a single species, or a plurality of species may be blended.

  Each of the impregnated rubber layer and the adhesive rubber layer (not shown) is constituted by an uncrosslinked rubber composition obtained by blending a raw material rubber with a compounding agent and kneading, and a rubber composition obtained by crosslinking the uncrosslinked rubber composition. .

  Examples of these raw rubbers include ethylene-α-olefin elastomers such as ethylene / propylene rubber (EPR) and ethylene propylene diene monomer rubber (EPDM), chloroprene rubber (CR), chlorosulfonated polyethylene rubber (CSM), hydrogen Addition acrylonitrile rubber (H-NBR), natural rubber (NR), styrene butadiene rubber (SBR), nitrile rubber (NBR) and the like can be mentioned. The raw rubber may be composed of a single species, or may be composed of a blend of a plurality of species.

  Examples of compounding agents include reinforcing materials such as carbon black, silica, and short fibers, processing aids, anti-aging agents, vulcanization accelerators, crosslinking agents (for example, sulfur and organic peroxides), plasticizers, and fillers. Etc. Each compounding agent may be composed of a single species or a plurality of species.

  Further, at least the surface portion of the V-ribbed belt B contains an abrasion modifier. Therefore, a layer that is covered with the reinforcing cloth and contains the wear modifier is provided on the surface portion of the belt.

  The wear modifier is included in, for example, rubber used for coating performed on the reinforcing cloth 13. Moreover, it may be contained in the whole belt 11 main body, and the layer which consists of rubber | gum containing an abrasion modifier on the surface of the belt main body 11 may be formed. Furthermore, it may be applied to the belt surface by spray coating or the like. In any case, at least the protrusion 19 contains the rubber with a wear modifier.

  The wear modifier used here is, for example, silicone oil, silicone resin, graphite, bentonite, molybdenum disulfide, nylon resin powder, methyl silicone rubber particles, fluororesin, and ultrahigh molecular weight polyethylene particles (UHMWPE, weight average molecular weight 1 million). Etc.). From the viewpoint of wear resistance and the like, silicone oil is particularly preferable in the present embodiment. The wear modifier may be composed of a single species, or a plurality of species may be mixed.

  As described above, a part of the rubber constituting the toothed belt 10 protrudes from the gap between the yarns constituting the reinforcing cloth 13 to form the protruding portion 19. Therefore, when the toothed belt 10 is wound around the pulley, the protrusion 19 containing the wear modifier contacts the pulley, so that the wear modifier functions effectively and the friction of the surface of the toothed belt 10 is reduced. The coefficient (μ) can be lowered (lower μ).

  However, it is not essential to have the protrusion 19. In the transmission belt of the present disclosure, the basis weight of the reinforcing cloth 13 is smaller than that of the conventional one, and the texture is rough. From this, the pulley contact surface of the opening area ratio, that is, the area of the gap portion between the yarns constituting the reinforcing cloth 13 (the area where the rubber (including the surface rubber) of the belt body 11 is exposed in the gap). The ratio to the whole is increasing. Therefore, even if the protruding portion 19 is not configured, the gap portion of the yarn comes into contact with the pulley, and the wear modifier is contained in the rubber in the portion, thereby realizing a low friction coefficient. A preferable opening area ratio is 30% to 90%, more preferably 50% to 90%. The opening area ratio can be set according to the fineness and density (number per dimension) of the yarn constituting the reinforcing cloth.

  Moreover, it is not essential to use the reinforcing cloth 13. In this case, as a matter of course, the rubber itself of the belt body 11 constitutes a pulley contact surface, and the wear modifier is contained in the portion, so that a low friction coefficient is realized.

-Belt manufacturing method-
Then, the manufacturing method of the exemplary toothed belt of this embodiment is demonstrated.

<Belt material preparation process>
-Uncrosslinked rubber sheet-
Each compounding agent is blended with the raw rubber while kneading with a kneader such as a kneader or a Banbury mixer, and the resulting uncrosslinked rubber composition is molded into a sheet shape by calendar molding or the like to produce an uncrosslinked rubber sheet.

-Core wire-
An adhesive treatment in which the yarn body is immersed in an RFL aqueous solution and heated and / or an adhesive treatment in which the yarn body is immersed in rubber paste and dried is performed to produce the core 12.

-Reinforcement fabric-
Reinforcement cloth 13 is produced by performing an adhesion treatment in which the cloth body is immersed in an RFL aqueous solution and then heated, an adhesion treatment in which the cloth body is dipped in rubber glue and dried, and an adhesion treatment in which the surface is coated with a high viscosity rubber glue and then dried. To do.

  Specifically, the cloth body is first immersed in an RFL aqueous solution and squeezed with a roll, and then heated in a heating furnace. Thereby, an RFL layer adheres so that the thread | yarn surface which comprises a cloth main body may be coat | covered. This process may be repeated a plurality of times.

  The RFL aqueous solution used at this time has, for example, an R / F mass ratio of 1 / 0.8 to 1/2, an RF / L mass ratio of 1/5 to 1/20, and a solid content concentration of 5 to 5. 20% by mass. The immersion time of the cloth body 14 in the RFL aqueous solution is, for example, 1 to 20 seconds. The heating temperature of the cloth body in the heating furnace is, for example, 140 to 180 ° C., and the heating time is, for example, 3 to 5 minutes. The adhesion amount (weight per unit area) of the RFL layer is, for example, 5 to 40% by mass with respect to the mass of the cloth body.

  Next, rubber paste impregnation treatment is performed. The rubber paste impregnation treatment is a treatment in which an impregnated rubber layer is formed by immersing a cloth body having an RFL film formed on the surface thereof in a rubber paste for an impregnated rubber layer and then squeezing with a squeeze roll to dry and scatter the solvent.

  The rubber paste for the impregnated rubber layer used at this time is blended with various raw rubbers such as ethylene propylene diene monomer rubber (EPDM), chloroprene rubber (CR), hydrogenated acrylonitrile rubber (H-NBR), acrylonitrile rubber (NBR), etc. An agent is blended and kneaded, and the kneaded product is dissolved in a solvent such as toluene or methyl ethyl ketone (MEK). The solid content concentration of the rubber paste for the impregnated rubber layer is, for example, 5 to 30% by mass.

  The drying temperature of the cloth body is, for example, 60 to 120 ° C., and the drying time is, for example, 3 to 10 minutes. The adhesion amount of the impregnated rubber layer 16 can be controlled by the number of times the cloth body is immersed in the impregnated rubber layer, the degree of drawing, and the like.

  Next, rubber paste application processing is performed. In the rubber paste coating process, the rubber paste for the adhesive rubber layer is applied to one surface of the cloth body on which the RFL film and the impregnated rubber layer are formed, and the solvent is dried after the rubber paste for the surface rubber layer is applied to the other surface. This is a process of scattering. Thereby, an adhesive rubber layer is formed on one surface of the cloth body, and a surface rubber layer (coating) is formed on the other surface.

  These rubber paste application processes 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 cloth body using a knife coater or the like. Then, for example, it is dried for 3 to 10 minutes under an atmospheric temperature of 60 to 120 ° C. The number of times of applying the rubber paste for the adhesive rubber layer may be one or may be repeated a plurality of times. The thickness of the adhesive rubber layer thus formed is, for example, 50 to 300 μm.

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

  Subsequently, similar to the application of the adhesive rubber layer rubber paste, the surface rubber layer rubber paste is applied to the surface of the cloth body opposite to the surface on which the adhesive rubber layer rubber paste is applied. Dry at an ambient temperature of 120 ° C. for 3 to 10 minutes. The thickness of the formed surface rubber layer is, for example, 50 to 500 μm.

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

  Here, the formation of the adhesive rubber layer is described as being performed prior to the formation of the surface rubber layer, but the adhesive rubber layer may be formed after the surface rubber layer is formed, or both may be formed in parallel. May be. Further, when a wear modifier is included in the belt main body 11 (whole or surface), it is possible not to provide a surface rubber layer.

  The adhesive rubber layer and the surface rubber layer may be formed by pasting, calendering, lapping, laminating, or the like.

  Through the above process, the reinforcing cloth 13 is prepared by performing an adhesion process on the cloth body. However, both the RFL process and the rubber paste process described above may be performed, one of them may be performed, or neither of them may be performed.

  In addition, before the process which immerses a cloth main body in RFL aqueous solution and heats, you may perform the process which immerses a cloth main body in an epoxy resin solution or an isocyanate resin solution, and heats it.

<Belt molding process>
The reinforcing cloth 13 is formed in a cylindrical shape so that the surface rubber layer is on the inside, and the cylindrical reinforcing cloth 13 is put on a cylindrical mold having a tooth portion forming groove on the mold surface. A core wire 12 is spirally wound thereon, and an uncrosslinked rubber sheet is wound thereon a predetermined number of times.

  Subsequently, the cylindrical mold on which the belt material is set is placed in a vulcanizer, and heated and pressurized for a predetermined time. As a result, the uncrosslinked rubber flows to form the toothed belt main body 11, and the core wire 12 and the reinforcing cloth 13 are bonded to the toothed belt main body 11, and the rubber is cross-linked as a whole to form a cylindrical slab. It is formed. Here, the heating temperature is, for example, 150 to 200 ° C., the heating pressure is, for example, 5 to 20 MPa, and the processing time is, for example, 10 to 30 minutes.

  Thereafter, the cylindrical mold is taken out from the vulcanizing pot, the slab is removed, the back surface thereof is polished to make the thickness uniform, and then the toothed belt 10 is obtained by cutting into a predetermined width.

  If the reinforcing cloth 13 is not used, the step of covering the cylindrical mold with the reinforcing cloth 13 is omitted. Further, the wear modifier is dispersed in a solvent and applied to the surface of the formed belt body. Application may be performed either before or after vulcanization. Moreover, as a coating method, for example, spray coating can be used.

  In the above, the case of the toothed belt has been described, and the example in which the layer containing the wear modifier coated on the reinforcing cloth is formed on the tooth surface portion has been described. However, it is not particularly limited to this. The configuration in which the layer including the reinforcing cloth and the wear modifier is provided on the pulley contact surface can be applied to the V-belt, V-ribbed belt, and flat belt, and can also be applied to the back side of the belt. is there.

<Toothed belt>
The toothed belts of Examples 1 to 7 and Comparative Examples 1 to 4 below were prepared. Each is listed in Table 1.

—Example 1—
A plain woven fabric with a basis weight of 100 g / m ² was used as the fabric body of the reinforcing fabric 13. This woven fabric has a warp yarn of warp and a woolly processed yarn using a thread of 6,6 nylon fiber with a thickness of 200 dtex and a thread of 6,6 nylon fiber with a thickness of 400 dtex, and the density of the warp yarn is 100 / 5cm. The density is 75 pieces / 5 cm.

  Further, as rubber paste for impregnated rubber, chloroprene rubber (made by Showa Denko, trade name: Shoprene GRT) is used as raw rubber, and carbon black FEF (made by Tokai Carbon Co., trade name) with respect to 100 parts by mass of the raw rubber. : Seast SO) 20 parts by mass, silica (trade name: Tokushiru GU) 15 parts by mass, stearic acid (manufactured by Nichiyu Co., Ltd., trade name: bead stearic acid) 1.5 parts by mass, anti-aging agent (Kawaguchi Chemical) Product made by Kogyo Co., Ltd., trade name: Antage NBC-F) 5 parts by mass, zinc oxide (made by Sakai Chemical Industry Co., Ltd., trade name: 2 types of zinc oxide), 6 parts by mass, magnesium oxide (made by Kamijima Chemical Co., Ltd., trade name: Starmag) H) An uncrosslinked rubber composition obtained by mixing and kneading 8 parts by mass and 3 parts by mass of a vulcanization accelerator (manufactured by Sanshin Chemical Industry Co., Ltd., trade name: Sunseller DM-G) has a solid concentration of 3 Was prepared was dissolved in toluene so that the mass%.

  Further, as the rubber paste for the surface rubber, a rubber paste similar to the rubber paste for the impregnated rubber but further containing a wear modifier was prepared. The wear modifier is silicone oil (Across Co., Ltd., trade name: α-coat), and the blending amount is 50 parts by weight with respect to 100 parts by weight of chloroprene rubber. Regarding the wear modifier, Table 1 shows this case as A.

  Furthermore, rubber paste for adhesive rubber using RFL aqueous solution and chloroprene rubber as raw material rubber was prepared.

  The cloth body was heated after being immersed in the RFL aqueous solution, and then the cloth body was immersed in rubber paste for impregnated rubber and then dried. Subsequently, a rubber paste for adhesive rubber was applied to the surface of the cloth body on the side of the toothed belt body and then dried. Subsequently, a rubber paste for the surface rubber was applied to the pulley contact side surface of the cloth body and then dried (coating). Thus, a reinforcing cloth was prepared.

  In addition, an uncrosslinked rubber sheet for forming a toothed belt body and glass fiber cords were prepared using chloroprene rubber as a raw rubber having the same composition as the rubber for the impregnated rubber (but may be a different composition). .

  Using the above uncrosslinked rubber sheet, core wire, and reinforcing cloth, a toothed belt was prepared in the same manner as in the above embodiment, and this was designated as Example 1.

  The toothed belt of Example 1 has a belt circumferential length of 840 mm and a belt thickness of 4.89 mm, a tooth profile of the tooth portion is an arc tooth profile, the number of teeth is 105, a tooth width is 19 mm, and a tooth height is The arrangement pitch was 2.89 mm and 8 mm.

—Example 2—
A woven fabric having a basis weight of 50 g / m ² was used as the fabric body of the reinforcing fabric 13. This woven fabric has a warp density of 50 yarns / 5 cm and a weft density of 37.5 yarns / 5 cm. The material and thickness of each yarn are the same as those in Example 1.

  About the point except the said cloth main body, ie, the material of rubber, the manufacturing method of a belt, etc., it is the same as Example 1.

—Example 3—
The same woven fabric as in Example 2 was used as the fabric body of the reinforcing fabric 13. Further, PTFE particles (manufactured by AGC, trade name: Lubricant L173J, average particle diameter 7 μm) were used as an abrasion modifier to be contained in the raw rubber of the surface rubber. Table 1 shows B. The compounding amount of the wear modifier is 50 parts by weight with respect to 100 parts by weight of chloroprene rubber.

  The other points are the same as in the first embodiment.

—Example 4—
The same woven fabric as in Example 2 was used as the fabric body of the reinforcing fabric 13. In addition, ultrahigh molecular weight polyethylene particles (manufactured by Mitsui Chemicals, trade name: Mipperon XM220, average particle diameter 35 μm, weight average molecular weight 2 million) were used as a wear modifier to be contained in the raw rubber of the surface rubber. Table 1 shows C. The compounding amount of the wear modifier is 50 parts by weight with respect to 100 parts by weight of chloroprene rubber.

  The other points are the same as in the first embodiment.

-Example 5-
As the cloth body of the reinforcing cloth 13, a woven cloth having a basis weight of 10 g / m ² was used. This woven fabric has a warp thickness of 50 dtex, a weft thickness of 100 dtex, a warp density of 40/5 cm, and a weft density of 30/5 cm. The material of each yarn is the same as that of the first embodiment. Further, the same ultrahigh molecular weight polyethylene particles as in Example 4 were used as the wear modifier contained in the raw rubber of the surface rubber (the blending amount is also the same as in Example 4).

  The other points are the same as in the first embodiment.

-Example 6-
In this example, the wear modifier was included in the rubber composition constituting the belt body 11 instead of being included in the rubber paste of the surface rubber layer (coating).

  The same woven fabric as in Example 2 was used as the fabric body of the reinforcing fabric 13.

  For the surface rubber formation, an uncrosslinked rubber composition containing no wear modifier (the other compounding was the same as the rubber paste for the impregnated rubber of Example 1) was prepared.

  Furthermore, an uncrosslinked rubber composition containing other silicone oil as an abrasion modifier (other compounding is the same as the rubber paste for impregnated rubber of Example 1) was prepared for the formation of a toothed belt body. The compounding amount of the wear modifier is 50 parts by weight with respect to 100 parts by weight of chloroprene rubber.

  In the same manner as in Example 1, the surface rubber was applied to the surface of the cloth body on the pulley contact side and dried after the rubber paste for the adhesive rubber to the cloth body was applied and dried.

-Example 7-
In this example, a toothed belt that does not use the reinforcing cloth 13 was created. In other respects, a toothed belt was prepared in the same manner as in the embodiment using the same uncrosslinked rubber sheet and core wire as in Example 1.

In addition, after the vulcanization of the toothed belt, the same wear modifier (A) as in Example 1 was dispersed in a solvent and applied to the tooth surface by spray coating.
-Comparative Example 1-
A woven fabric having a basis weight of 200 g / m ² was used as the fabric body of the reinforcing fabric. This woven fabric has a warp density of 200 yarns / 5 cm and a weft density of 150 yarns / 5 cm. The material, thickness, etc. of each yarn are the same as in Example 1.

  Further, rubber paste containing no wear modifier (other ingredients are the same as in Example 1) was used for forming the surface rubber layer.

  The other points are the same as in the first embodiment.

—Comparative Example 2—
A woven fabric having a basis weight of 350 g / m ² was used as the fabric body of the reinforcing fabric. This fabric has a density of warp 350 present / 5 cm, density of the weft is 262.5 / 5 cm, the material of the yarn, thickness, etc. were the same as in Example 1.

  Further, rubber paste containing no wear modifier (other ingredients are the same as in Example 1) was used for forming the surface rubber layer.

  The other points are the same as in the first embodiment.

—Comparative Example 3—
The same woven fabric as in Comparative Example 1 was used as the fabric body of the reinforcing fabric. This woven fabric is 200 g / m ² .

  Further, the same rubber paste as in Example 1 containing silicone oil as an abrasion modifier was used for forming the surface rubber layer.

  The other points are the same as in the first embodiment.

—Comparative Example 4—
The same woven fabric as in Example 1 was used as the fabric body of the reinforcing fabric 13.

  Further, rubber paste containing no wear modifier (other ingredients are the same as in Example 1) was used for forming the surface rubber layer.

  The other points are the same as in the first embodiment.

<Abrasion resistance test>
A test for evaluating the wear resistance of the toothed belts of Examples 1 to 7 and Comparative Examples 1 to 4 on the carbon steel (S45C) pulley using the belt running test machine 30 having the layout shown in FIG. Went.

  First, the weight of each belt was measured.

  As shown in FIG. 3, the belt running test machine 30 includes a large-diameter driven toothed pulley 31 (number of teeth 42) and a small-diameter driving toothed pulley (number of teeth) provided on the side (right side in the figure). 21) and an idler pulley 33 which is a flat pulley for pressing the back surface of the belt. The belt was wound around the belt running test machine 30 so as to be horizontal from the driven toothed pulley 31 toward the driving toothed pulley 32. A load torque of 29.4 N is applied to the driven toothed pulley 31, a dead weight is added to the driving toothed pulley 32 so that a belt tension of 216 N is applied, and the driving toothed pulley 32 is rotated (clockwise) at an ambient temperature of 100 ° C. 6000 rpm) and the belt was run.

  After running for 300 hours, the weight of each toothed belt was measured. Furthermore, the mass difference between the toothed belts before and after running was calculated as the amount of wear. Table 1 shows values converted into 100 for the case of Comparative Example 1 for each belt.

<Durable life test>
Using the same belt running test machine and conditions as in the test for evaluating the wear resistance, the toothed belts of Examples 1 to 7 and Comparative Examples 1 to 4 are run, and the time until tooth missing occurs Measured as the endurance life. Table 1 shows values converted into 100 for the case of Comparative Example 1 for each belt.

<Measurement of friction coefficient>
For each toothed belt of Examples 1 to 7 and Comparative Examples 1 to 4 using the friction coefficient measuring device 40 shown in FIG. 4, between the belt tooth tip and carbon steel (S45C) generally used as a pulley material. The test which calculates | requires the friction coefficient of was conducted.

  First, the test piece 41 obtained by cutting out a part of the toothed belt was bonded and fixed to the test piece fixture 42 with the belt teeth facing downward. Next, the belt tooth tip of the test piece 41 is brought into contact with the sliding plate 43 made of carbon steel (S45C), and the weight 44 is placed on the test piece mounting tool 42 to press the belt tooth tip against the sliding plate 43. I let you.

  Subsequently, the surface of the sliding plate 43 was slid on the belt tooth tip by moving the sliding plate 43 in the direction of the arrow, and the resistance load was detected by the load cell 45 connected to the test piece fixture 42. The friction coefficient was calculated by dividing this resistance load by the mass of the weight 44.

<Noise test>
Using the belt running tester 50 having the layout shown in FIG. 5, tests for evaluating noise during belt running were performed on the toothed belts of Examples 1 to 7 and Comparative Examples 1 to 4.

  First, a toothed belt is wound around a belt running test machine 50 composed of a driving pulley 51 (number of teeth 24) and a driven pulley 52 (number of teeth 24), and a load is applied to the driven pulley 52 in the rearward direction to form a toothed belt. A constant tension was applied to the.

  Next, the toothed belt is caused to travel by changing the rotational speed of the driving pulley 51 in the range of 300 to 5000 rpm, and the sound collecting microphone 53 disposed at a position 10 cm away from the position where the driving pulley 51 and the belt start to mesh with each other. Measure the sound pressure of the noise.

  The measurement results are shown in Table 1 in the unit db (decibel).

<Test evaluation results>
Table 1 shows the results of each test.

  When Examples 1 to 6 are compared with Comparative Example 1, each of them has a durability life (tooth-breaking durability life) that is twice or more higher, excellent wear resistance and sound performance, and a low friction coefficient.

  Comparing Example 1 and Comparative Example 4 in which the basis weight of the reinforcing fabric is the same and the presence or absence of the wear modifier is different, Comparative Example 4 is slightly superior in terms of durability. However, Example 1 is clearly superior in terms of wear resistance, friction coefficient, and sound performance, and it is considered that these points were improved by the wear modifier.

  Compared to Example 1, Example 2 in which the fabric weight of the reinforcing cloth is half is excellent in terms of the durability life, and is equivalent in other respects. That is, even if the fabric weight of the reinforcing cloth is reduced, the performance is not only maintained but rather improved.

  Examples 3 and 4 are examples in which the wear modifier is different from Example 2, but the performance is generally the same. That is, various wear modifiers can be used to exert the effects of the present disclosure.

  Example 5 is an example in which the same wear modifier as in Example 4 was used and the basis weight of the reinforcing cloth was reduced by 0.2 times. Example 5 has a larger coefficient of friction than Example 4, but has a significantly longer durability life and is equivalent in terms of wear resistance and sound performance. That is, the basis weight of the reinforcing cloth can be significantly reduced as compared with the prior art, which is conventional common sense.

  Example 6 is an example in which an abrasion modifier is included in the belt body, and the results are substantially the same as in Example 1 where the abrasion modifier is included in the surface rubber layer.

  However, when comparing the case where the wear modifier is included in the belt body and the case where the surface rubber is included, the amount of the wear modifier necessary to make the amount of the wear modifier on the tooth surface comparable. Is less when the surface rubber contains a wear modifier. Therefore, it is advantageous in terms of cost reduction to include a wear modifier in the surface rubber.

  Example 7 is an example in which a wear modifier was applied to the belt surface without using a reinforcing cloth. In this case, the durability life is slightly inferior to those of Examples 1 to 6 using the reinforcing cloth. However, the wear resistance, friction coefficient, and sound performance are comparable.

  Even when the wear modifier is used, when the weight of the reinforcing fabric is large as in Comparative Example 3 (twice that of Example 1), the performance of the wear modifier is lower than that of Comparative Example 1 in which the wear modifier is not used. The improvement is small. That is, in the case of using a reinforcing cloth, it is desirable to reduce the basis weight of the reinforcing cloth as compared with the conventional case.

  Further, as in Comparative Example 2, when the weight of the reinforcing cloth is further increased without using the wear modifier, the wear resistance and the friction coefficient are greatly improved, and the sound performance is excellent. Will deteriorate significantly.

As described above, wear resistance, friction coefficient, sound performance and durability can be obtained by using a wear modifier and not using a reinforcing cloth, or by setting the weight of the reinforcing cloth to a significantly smaller value than before. The life can be improved in a well-balanced manner. Considering performance such as cost reduction and coefficient of friction, it is preferably 10 g / m ² or more and 200 g / m ² or less, more preferably 40 g / m ² or more and 80 g / m ² or less.

  The toothed belt of the present disclosure has excellent balance of wear resistance, coefficient of friction, sound performance, and durability life, so it is useful as a power transmission belt for general industrial applications such as automotive OHC drive applications and injection molding machine applications. It is.

DESCRIPTION OF SYMBOLS 10 Toothed belt 11 Belt main body 11 Toothed belt main body 11a Tooth rubber part 11b Back rubber part 12 Core wire 13 Reinforcement cloth 14 Cloth main body 16 Impregnation rubber layer 19 Protrusion part 30 Belt running test machine 31 Driven toothed pulley 32 With drive tooth Pulley 33 Idler pulley 40 Coefficient of friction measurement device 41 Test piece 42 Test piece mounting tool 43 Slide plate 44 Weight 45 Load cell 50 Belt running tester 51 Drive pulley 52 Driven pulley 53 Sound collecting microphone

Claims (8)

A transmission belt having a belt body formed of a rubber composition,
A surface layer containing a wear modifier is formed on at least a part of the surface of the belt body,
The surface layer includes a surface reinforcing cloth provided to cover the surface of the belt body,
A part of the rubber composition containing the wear modifier protrudes beyond the surface reinforcing cloth. In claim 1,
The transmission belt characterized in that the basis weight of the surface reinforcing fabric is 10 g / m ² or more and 200 g / m ² or less. In claim 1 or 2,
The power transmission belt, wherein the wear modifier is dispersed in a thermoplastic resin, a thermosetting resin, or an elastomer. In any one of Claims 1-3,
The power transmission belt, wherein the surface layer is coated with the wear modifier. In claim 2,
The surface reinforcing cloth is coated,
The power transmission belt, wherein the wear modifier is contained in a material of the coating. In any one of Claims 1-5,
The transmission belt is a toothed belt,
The power transmission belt, wherein the surface layer is formed on a surface portion of the tooth. In claim 1,
The transmission belt characterized in that the basis weight of the surface reinforcing fabric is 20 g / m ² or more and 80 g / m ² or less. In any one of Claims 1-7,
The wear modifier includes at least one of silicone oil, silicone resin, graphite, bentonite, molybdenum disulfide, nylon resin powder, methyl silicone rubber particles, fluororesin, and ultrahigh molecular weight polyethylene particles. Transmission belt.

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