JP2001304343A - Toothed belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toothed belt, having high transmission force and improved service life by improving wear resistance. SOLUTION: This toothed belt A has a plurality of tooth parts 3, arranged at prescribed spaces along the longitudinal direction, and a back part 2 with cores 1 embedded. The surface of the tooth parts 3 is covered with tooth cloth 4. A rubber layer, constituting at least the tooth parts 3, is formed of rubber, comprising a polymer component with nitrile hydride rubber and unsaturated carboxylic acid type metal salt mixed in mass ratio of 60:40-40:60, and the tooth cloth 4 is impregnated and covered with a first adhesive component 13 to the rubber layer, so that the surface, back face and interior of the tooth cloth 4 are in a mutually communicated state. At least one kind of antifriction material selected from graphite and molybdenum disulfide is contained in the first adhesive component 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toothed belt in which a transmission surface is covered with a fiber material, and more particularly to a toothed belt in which the frictional resistance of the fiber material is reduced over a long period of time and belt failure due to reduction of tooth skipping does not occur. About.

[0002]

2. Description of the Related Art Synchronous transmission toothed belts used in general industries and conveyor toothed belts required for precise positioning accuracy used in small machines are required to have a higher transmission force and a higher load. Extension of replacement cycle is required.

[0003] The failure modes of the toothed belt are roughly classified into cutting of the belt due to fatigue of the cord, and chipping due to overload and wear of the tooth cloth. For cutting due to core wire fatigue, use of aramid core wire or small diameter core wire of high-strength glass, use of hydrogenated nitrile rubber (H-NBR) composition with excellent heat resistance, belt for improvement of engine side This has been improved by the use of an auto-tensioner that keeps the tension constant both at the time of starting and at the time of running, and the occurrence of cutting failure has been reduced.

[0004] On the other hand, as rubber constituting the toothed belt,
In response to the increasingly severe use environment, chloroprene rubber has been changed to chlorosulfonated polyethylene, and nowadays, more heat-resistant materials have been used for hydrogenated nitrile rubber. The performance is improved.

[0005] In addition, the hydrogenation rate, type of crosslinking agent, and various additives of hydrogenated nitrile rubber, which is currently most widely used as rubber for toothed belts for automobile engines, are determined by Durability has been improved. For example, JP-A-8-3374 discloses a belt using a rubber composition prepared by adding a fiberizable fluororesin containing a polyfunctional co-crosslinking agent to solid rubber.

Further, the hydrogenated nitrile rubber contains a metal salt of an unsaturated carboxylic acid to improve the abrasion resistance and the crack resistance. The improved rubber constitutes the teeth and the back of the toothed belt. Something to do is also provided. (JP-B 5-64252, JP-B-6
See JP-A-37576 and JP-B-5-262914. )

[0007]

[0005] However, the occurrence of tooth chipping has been taken, although measures such as the use of high-strength type tooth cloth using nylon 6-6 or aramid fiber have not been taken yet. . Therefore, in order to further improve the chipping resistance of the toothed belt coated with the tooth cloth, it is considered effective to reduce the friction coefficient of the tooth cloth surface. EP0
662571B1 proposes a toothed belt in which a polymer matrix layer containing a fluororesin is sprayed or coated on the outside of a woven fabric layer of a tooth cloth. This fluororesin is bound without a boundary layer in a special polymer matrix. Then, the polymer matrix is bonded to the tooth cloth. However, because the fluoropolymer is tightly bound to the polymer matrix,
There has been a problem that the fluororesin remains surrounded by the matrix and the effect of reducing the friction coefficient by the fluororesin cannot be sufficiently exhibited. In addition, due to material limitations of the polymer matrix, the amount of fluororesin that can be contained is small,
There has been a problem that the thickness of the polymer matrix layer is also reduced, and the improvement of tooth chipping resistance by the fluororesin is not sufficient.

In Japanese Patent Application Laid-Open No. Hei 7-151190, the surface and the inside of a tooth cloth are impregnated with a rubber composition containing a fibrous fluororesin, and the back surface of the tooth cloth is applied to a rubber layer of a belt body via an adhesive layer. Coupling toothed belts have been proposed. The reason why the fluororesin in the rubber composition is fiberized by the kneading step or the like is to prevent the fluororesin in the rubber composition from becoming foreign matter and reducing the strength of the rubber composition. However, there has been a problem that the fluororesin fiberized in the rubber composition has few opportunities to be exposed on the friction surface, and the effect of reducing the friction coefficient by the fluororesin is not sufficient. Further, in order to maintain the strength without converting the fluororesin into fibers to form foreign substances, only about 1 to 30 parts by weight of the fluororesin can be contained with respect to 100 parts by weight of the rubber impregnated in the tooth cloth. There is a problem that the improvement of the tooth chipping property is not sufficient.

Further, in the case of a toothed belt which is forced to transmit a high load even in the general industrial use, the above-mentioned Japanese Patent Application Laid-Open No. 8-3374 is disclosed.
With the use of the rubber composition provided in the publication, when the teeth are engaged with the pulley because the hardness of the rubber is high, the teeth rebound greatly due to the impact, and this is one of the causes of the vibration of the belt. As a result, there is a problem that noise and the life of the belt may be adversely affected. In addition, when the rubber composition provided in JP-A-8-3374 is used for the back part of a toothed belt, elongation and tensile modulus are insufficient. There is a problem that the expected effect in crack resistance cannot be obtained, and further, there is a problem that abrasion or a crack is easily caused by contact with a tension pulley, an idler pulley, or the like.

Further, in the synchronous transmission belt, when the load torque is increased, the meshing between the pulley and the belt, called jumping (tooth skipping phenomenon), is displaced, and a phenomenon occurs in which the belt rides on the pulley and the synchronous transmission cannot be performed. The load torque at which jumping occurs is called jumping torque. Further, in the case of the synchronous transmission belt, jumping occurs even when the belt is stretched after running for a long time and the tension is reduced. When jumping occurs, a shocking force is intermittently applied to the belt, which leads to damage of the belt. Conventional synchronous transmission belts use chloroprene rubber and hydrogenated nitrile rubber, and the teeth of the belt are flexible.

However, when the above rubber is used, the teeth are flexible, and when the load torque is increased, the teeth are deformed when the belt meshes with the driven pulley, and the belt rides on the pulley and jumping occurs. I was

On the other hand, in order to increase the jumping torque, reduce the deformation of the teeth, and increase the hardness of the teeth, in order to increase the hardness of the conventional chloroprene rubber or hydrogenated nitrile rubber, the amount of carbon, fillers, and rubber reinforcement such as short fibers. When the compounding amount of the material is increased, the teeth cannot be accurately formed by the conventional press-fitting method, so that the production of the toothed belt cannot be performed.

The present invention has been made in view of the above points, and has as its object to provide a toothed belt which has a high transmission force and an improved wear resistance, thereby having an improved life.

[0014]

According to the present invention, there is provided a toothed belt having a plurality of teeth arranged at predetermined intervals along a longitudinal direction, and a back having a core buried therein. In a toothed belt coated with a tooth cloth having a rubber layer, at least a rubber layer constituting a tooth portion is a polymer in which a hydrogenated nitrile rubber and an unsaturated carboxylic acid metal salt are mixed at a mass ratio of 60:40 to 40:60. A toothed belt made of rubber composed of components. Further, a first adhesive component with the rubber layer is impregnated and coated so that the front and back surfaces and the inside of the tooth cloth communicate with each other, and at least one selected from graphite or molybdenum disulfide in the first adhesive component. One kind of anti-friction material is included, and a second rubber composition is coated as the rubber layer on the tooth cloth to which the first adhesive component has been added, and the second rubber composition contains the second resin in the second rubber composition. The rubber composition is dispersed without being bonded to the rubber composition, and the second rubber composition and the first rubber composition constituting the teeth and the back are integrated by vulcanization and pressurization.

[0015] At least the rubber layer constituting the tooth portion is composed of a hydrogenated nitrile rubber and an unsaturated carboxylic acid metal salt at 60:40.
By forming the rubber composed of the polymer components mixed at a mass ratio of ４０40: 60, the teeth can be accurately formed, and the transmission force of the belt can be increased by increasing the jumping torque. A first rubber component comprising at least one anti-friction material selected from graphite or molybdenum disulfide in a yarn constituting a tooth cloth;
By providing the adhesive component, graphite or molybdenum disulfide can be focused on the front and back surfaces of the fiber fabric and each fiber constituting the fiber fabric, and a large amount of graphite or molybdenum disulfide can be entangled with the tooth cloth. Furthermore, the abrasion resistance of the rubber layer on the tooth cloth surface is also improved by attaching the second rubber composition in which the fluororesin is dispersed to the surface of the first adhesive component.

According to a second aspect of the present invention, there is provided a tooth cloth having a plurality of teeth arranged at predetermined intervals along a longitudinal direction and a back having a core wire embedded therein, and having a rubber layer on the surface of the teeth. In the toothed belt thus obtained, at least the first rubber composition constituting the tooth portion is obtained by mixing a rubber comprising a polymer component obtained by mixing a hydrogenated nitrile rubber and an unsaturated metal carboxylate in a mass ratio of 60:40 to 40:60. The first adhesive component to be used with the rubber layer containing at least one kind of anti-friction material selected from graphite or molybdenum disulfide so that the front and back surfaces and the inside of the tooth cloth are in communication with each other. Impregnated and coated, and further coated on the tooth cloth provided with the first adhesive component with a second rubber composition as the rubber layer, wherein a fluororesin is bonded to the second rubber composition in the second rubber composition. The second rubber set without 5 100 weight parts of rubber in the object
A compound added and dispersed by adding 0 to 400 parts by weight, or a compound added and dispersed by adding 100 to 250 parts by weight of a powdery fluororesin to 100 parts by weight of the rubber in the second rubber composition is adhered. The fluororesin is not bonded to the second rubber composition, but is directly bonded to the second rubber composition and the first rubber composition forming the teeth and the back. Preferably, the composition is applied in an amount of 7 to 40% by weight based on the weight of the tooth cloth before the adhesion treatment, and more preferably between the second rubber composition and the first adhesive component, or the second rubber composition. Straddling the object and the first adhesive component,
An adhesive layer for a tooth cloth is provided with a rubber compound containing an isocyanate compound as a second adhesive component, and more preferably, the fluororesin is made into a powdery form, and the powder has an average powder diameter of 0.1.
1 to 500 μm.

The fluororesin which does not bind to the second rubber composition is added in an amount of 50 to 400 parts by weight per 100 parts by weight of the second rubber composition.
When the fluorine resin is contained in a large amount such that it becomes 100 parts by weight or 100 to 250 parts by weight, the degree of exposure of the fluororesin on the friction surface is increased, and the effect of reducing the friction coefficient is exhibited.

In the first and second aspects of the present invention, the first rubber composition of the tooth cloth may further include an antifriction material other than the fluororesin, or the second rubber composition of the tooth cloth may be used. It is preferable that the first rubber composition of the tooth portion and the back portion is of the same type. Alternatively, it is preferable that graphite or molybdenum disulfide contained in the first adhesive component is in a powder form, and the particle size of the powder is 0.1 to 500 μm. When an antifriction material other than the fluororesin is added to the second rubber composition, the effect of reducing the friction coefficient by the fluororesin and both the fluororesin and the other antifriction material is exhibited. When the second composition of the tooth cloth and the first rubber composition of the belt body are made of the same quality, even if a large amount of unbonded fluororesin is contained in the second rubber composition of the tooth cloth, the second rubber composition and Bonding of the first rubber composition can be secured.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing the entire structure of a toothed belt of the present invention, FIG. 2 is an enlarged sectional view of a fiber material (tooth cloth) coated on the tooth surface of the toothed belt, and FIG. It is a figure which shows the enlarged photograph of the cross section of the fiber material (tooth cloth) coat | covered on the tooth surface of the belt.

In FIG. 1, a toothed belt A includes a plurality of teeth 1 arranged at predetermined intervals along a longitudinal direction, a back 3 continuous with the teeth 1, and a core 2 buried in the back 3. , And a tooth cloth 4 coated on the surface of the tooth portion 1. The back 3 and the teeth 1 constitute a belt body formed of a rubber compound 9. In addition, the tooth cloth 4 is configured using a fiber material formed by weaving a weft 7 extending in the longitudinal direction of the belt and a warp 8 extending in the width direction of the belt. As described above, the fiber material of the tooth cloth is coated on the transmission surface of the belt, and is entirely or partially coated on the front surface of the belt body.

The back 3 and the teeth 1 are formed by a rubber layer made of the first rubber composition. Here, in the present invention, as the rubber constituting at least the tooth portion 3, a hydrogenated nitrile rubber and a metal salt of an unsaturated carboxylic acid are 60:40.
It is preferable to be formed of a rubber composed of a polymer component mixed at a mass ratio of ４０40: 60.

If the unsaturated carboxylic acid metal salt is smaller than 40, the rubber hardness does not reach a predetermined value, the rigidity of the tooth portion does not appear as intended, and the belt is jumped on the pulley because the tooth is flexible. The problem still exists. On the other hand, when the unsaturated carboxylic acid metal salt is larger than 60, there is a problem that the adhesive force between the tooth cloth and the rubber of the tooth part becomes small, and the tooth cloth is separated from the rubber of the tooth part during belt running.

The hydrogenated nitrile rubber used for the rubber constituting at least the tooth portion 3 needs to have a hydrogenation rate of at least 90% from the viewpoint of heat resistance, and 92 to 98%. It is suitable. By blending a metal salt of an unsaturated carboxylic acid with the hydrogenated nitrile rubber, the modulus (tensile modulus) and hardness are increased, and the modulus (tensile modulus), elongation at break, and higher In order to ensure the tear strength and the hardness, it is necessary to mix the hydrogenated nitrile rubber and the unsaturated carboxylic acid metal salt at a mass ratio of 60:40 to 40:60 as described above. The unsaturated carboxylic acid metal salt is not particularly limited, but zinc acrylate, zinc methacrylate, and the like can be used. still,
It is possible to increase the modulus (tensile elastic modulus) by reinforcing with carbon black without using a metal salt of unsaturated carboxylic acid, but the cutting elongation and tear strength of the rubber are reduced, and the deformation and bending of the rubber In a manufacturing method of a press-fitting method in which sufficient durability against crack generation cannot be imparted, and further, a tooth portion is formed by press-fitting rubber, the tooth portion is not precisely formed, which is not preferable.

The above-mentioned organic peroxide compounded in the polymer component consisting of the hydrogenated nitrile rubber and the metal salt of unsaturated carboxylic acid is used as a crosslinking agent, and has a predetermined modulus (tensile modulus) and elongation at break. In order to ensure the degree, it is necessary to blend 0.2 to 10 parts by mass of the organic peroxide with respect to 100 parts by mass of the polymer component as described above to perform crosslinking. The organic peroxide is not particularly restricted but includes, for example, 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, di-t
-Butyl peroxide, dibutyl cumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,
5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne, 1,3-bis (t-butylperoxyisopropyl) benzene, t-butyl Peroxyisopropyl carbonate and the like can be used. In addition to such an organic peroxide, an appropriate amount of a sulfur compound, an oxime nitroso compound, or a monomer or polymer generally used as a co-crosslinking agent may be added.

Further, in addition to these, carbon black, a plasticizer, and the like can be appropriately added to the extent that hardness, modulus (tensile elastic modulus) and cutting elongation are secured, and appropriate tear strength is secured. It is preferable that carbon black is blended in an amount of 5 to 50 parts by mass based on 100 parts by mass of the polymer component composed of the hydrogenated nitrile rubber and the unsaturated carboxylic acid metal salt.

As shown in FIG. 2, in the tooth cloth 4 of the toothed belt, a first adhesive component for bonding the rubber layer to the tooth cloth exists between the fibers of the tooth cloth 4 and inside the fibers. By doing so, at least one kind of antifriction material selected from graphite or molybdenum disulfide powder contained in the first adhesive component is contained so as to be bundled. 8 is present in a large amount between the front surface, the back surface, and the fibers of the fibrous material obtained by weaving No.8.

Further, a second rubber composition 5 to be the rubber layer is applied to at least the surface side of the tooth cloth 4 coated with the first adhesive component. Inside the second rubber composition 5, powdery fluororesin 6 is dispersed and disposed. And the fluororesin 6 and the 2nd rubber composition 5 are not couple | bonded, and the clearance gap 10 is formed in all or one part of the circumference | surroundings. The tooth portion 1 and the back portion 3 covered with the tooth cloth 4 are formed of a first rubber composition 9 mainly composed of rubber.

The fluororesin 6 and the first rubber composition 5 are not chemically bonded to each other while the fluororesin 6 remains in a powdery state. Therefore, when the tooth cloth 4 is subjected to a friction action, the fluororesin 6 contained in the second rubber composition 5 is largely exposed to the friction surface, and effectively exerts a friction coefficient reduction action. When the second rubber composition 5 is present on both sides of the tooth cloth 4, the second rubber composition 5 is heated and vulcanized with the first rubber composition 9 of the belt body (teeth 1 and back 3). Even if a large amount of powdery fluororesin 6 is mixed with the second rubber composition 5, the boundary surface 11 between the tooth cloth 4 and the belt body
Are firmly joined.

The fluorine resin present in the second rubber component and the first adhesive component 13 contain a large amount of graphite 12, and the weft 7 and the warp 8 forming the tooth cloth 4.
It exists in connection with. The action of the fluorine resin present in the second rubber component and the graphite present in the first adhesive component is as follows.
Abrasion occurs due to friction between the second rubber component having the above-mentioned and the pulley, but the friction coefficient is smaller than the case where no fluororesin is present because the fluororesin is dispersed and present in the second rubber component. As a result, the second rubber composition is excellent in abrasion resistance, and the abrasion of the second rubber composition is slow. Furthermore, even if the second rubber composition is worn out and disappears, the graphite
2 is present and appears on the sliding surface with the pulley surface, so that the wear resistance around the tooth cloth 4 is excellent, and the wear of the tooth cloth 4 is higher than that of the conventional belt. Can be extremely slowed down, and the life of the toothed belt can be extremely extended. Here, even if molybdenum disulfide is used instead of graphite 12, the same effect is obtained.

As the material of the fiber material forming the weft 7, warp 8 and the like of the tooth cloth 4, any one of nylon, aramid, polyester, polybenzoxazole, cotton and the like, or a combination thereof can be adopted. The form of the fiber may be any of a filament yarn and a spun yarn, and may be a twisted yarn of a single composition, a mixed twisted yarn, or a mixed spun yarn. Mixture 2
Fibers in which the fluororesin powder 23, rubber component 21, and resin-based adhesive component 22 of No. 4 are so thick that they can be impregnated between the fibers are preferable. In the case of a toothed belt, nylon, aramid or the like is used depending on the use environment and required life.

The weaving structure can include a large amount of the graphite powder 12 or the molybdenum disulfide powder 23 in any of a twill weave, a satin weave, and a plain weave. The thickness and density of the yarn are selected so that the mixture 24 in which the graphite powder 12 is dispersed is in communication with each other on the front and back surfaces and inside the fiber material.

Second rubber composition 5 impregnated and coated on tooth cloth 4
For the rubber, a rubber compound of the same type as that of the belt body is dissolved in a solvent such as methyl ethyl ketone (MEK) or toluene, and a fluororesin powder or a lubricating material other than the fluororesin powder is added to form a treatment liquid. It is formed by drying and solidifying after application. Examples of the lubricating material other than the fluororesin powder include one or more of graphite having a layered structure, molybdenum disulfide, glass beads, ceramic powder, spherical phenol resin powder, and aramid, polyamide, polyester, polybenzoxazole, fiber cut yarn or powder. Can be exemplified. In particular, graphite is well compatible with rubber components, and is effective as a durable antifriction material.

The core 1 embedded in the belt body is not limited, and a glass core and an aramid core are generally used. Further, any of twisted cords composed of polybenzoxazole, polyparaphenylene naphthalate, polyester, acryl, carbon, and steel can be used. The composition of the glass core wire may be either E glass or S glass (high-strength glass), and is not limited by the thickness of the filament, the number of bundled filaments, and the number of strands. Further, a sizing agent used as a bonding material and a protective material for a glass filament during bending, RFL,
It is not limited to an overcoat agent or the like. On the other hand, the aramid core wire is not limited by the difference in the molecular structure of the material, the core wire configuration, the size of the filament, or the adhesive treatment agent. Similarly, there is no particular limitation on the twisted cord of the core wire having another composition.

In order to obtain an excellent bond between the belt body and the tooth cloth 4, it is preferable to apply a treatment for imparting an adhesive component to the fiber used for the tooth cloth 4. The following method is preferred as the method for providing the adhesive component.

The untreated tooth cloth is immersed in a pretreatment solution containing an isocyanate compound, an epoxy compound, or an RFL solution at room temperature for 0.5 to 30 seconds, and then heated at 150 to 190 ° C.
Dry in oven adjusted for 2-5 minutes. In the pretreatment liquid, at least one kind of antifriction material selected from graphite or molybdenum disulfide is previously mixed and dispersed. The graphite or molybdenum disulfide used at this time has a particle size of 0.1 to 500 μm, and more preferably a fine particle of 0.1 to 10 μm. The pretreatment liquid adheres to the untreated tooth cloth, functions as an adhesive component after drying, and has a function of adhering the tooth cloth and the second rubber composition. Then, by mixing and dispersing at least one kind of lubricating material selected from at least graphite or molybdenum disulfide in the pretreatment liquid, the pretreatment liquid adheres to the tooth cloth and is dried to form a tooth cloth. Graphite or molybdenum disulfide is present around the fibers to be formed, and has the effect of preventing the abrasion of the fibers. Furthermore, if a layered structure of graphite or molybdenum disulfide is used, even if wear of the toothed belt surface progresses, the above-mentioned anti-friction material will continuously appear on the sliding surface with the pulley, so The coefficient of friction of the sliding surface with this is low, the wear resistance is good, and the wear of the tooth cloth can be sufficiently suppressed.

Examples of the isocyanate compound used in the above pretreatment liquid include 4,4'-diphenylmethane diisocyanate, tolylene 2,4-diisocyanate, polymethylene polyphenyl diisocyanate, hexamethylene diisocyanate, and polyaryl polyisocyanate (for example, as trade names). PAPI). This isocyanate compound is also used by being mixed with an organic solvent such as toluene and methyl ethyl ketone. Further, a blocked polyisocyanate in which an isocyanate group of the polyisocyanate is blocked by reacting a blocking agent such as a phenol, a tertiary alcohol, or a secondary alcohol with the above isocyanate compound can also be used.

Examples of the epoxy compound used in the pretreatment liquid include polyhydric alcohols such as ethylene glycol, glycerin and pentaerythritol, and reaction of polyalkylene glycol such as polyethylene glycol with a halogen-containing epoxy compound such as epichlorohydrin. And a reaction product with a polyhydric phenol such as resorcin, bis (4-hydroxyphenyl) dimethylmethane, phenol, formaldehyde resin, and resorcin-formaldehyde resin, or a halogen-containing epoxy compound. The epoxy compound is used by being mixed with an organic solvent such as toluene and methyl ethyl ketone.

Further, the RFL solution used in the pretreatment solution is a mixture of an initial condensate of resorcinol and formalin, and at least one rubber latex selected from nitrile rubber latex and hydrogenated nitrile rubber latex. In this case, it is preferable that the molar ratio of resorcinol to formalin be 3/1 to 1/3 in order to increase the adhesive strength. The initial condensate of resorcinol and formalin is mixed with rubber latex such that the resin content is 5 to 100 parts by mass with respect to 100 parts by mass of rubber of rubber latex, and the total solid concentration is 5 to 100 parts by mass. Adjusted to 40% concentration.

The fluororesin 6 of the present invention is in a state of being dispersed in the rubber composition, and does not directly bond to and adhere to the fibers of the untreated tooth cloth. Therefore, after the fiber is treated in advance with any of the adhesive components of RFL, epoxy resin, and isocyanate by the above-described method, a rubber composition in which a fluororesin is dispersed is laminated, and the rubber of the belt body is subjected to pressure vulcanization. To firmly adhere the fiber and the belt body. Alternatively, an adhesive component such as an epoxy resin or an isocyanate may be added to a treatment solution obtained by dissolving a blend of a fluororesin and a rubber composition in a solvent to directly adhere to an untreated tooth cloth. This is because the rubber composition containing the fluororesin adheres to the fiber surface of the woven fabric for a tooth cloth via an epoxy resin or isocyanate adhesive component layer. Although the fluororesin does not directly adhere to the rubber composition and the fiber surface, the fluororesin is dispersed in the rubber composition and exists on the very close surface of the fiber, so that the stress applied to the tooth bottom due to friction during belt running is reduced. When the tooth cloth is reduced, the fluorine resin works effectively and contributes to the improvement of the durability of the belt.

Further, as shown in FIG. 2, a third rubber composition 30 comprising a rubber compound containing an isocyanate compound as a second adhesive component is interposed between the second rubber composition 5 and the first adhesive component 13. By providing the adhesive layer for toothpaste, the third rubber composition 30 functions as an intermediate layer for increasing the adhesive strength, and the isocyanate compound acts as an adhesive component. The rubber composition is formed by dissolving the rubber compound in a solvent such as methyl ethyl ketone (MEK) and toluene, adding an isocyanate compound to form a treatment liquid, applying the treatment liquid, and then drying and solidifying the treatment liquid. Examples of the isocyanate compound used in the treatment liquid include 4,4′-diphenylmethane diisocyanate, tolylene 2,4-diisocyanate, polymethylene polyphenyl diisocyanate, hexamethylene diisocyanate, and polyaryl polyisocyanate (for example, PAPI is a trade name). Etc. This isocyanate compound is also used by being mixed with an organic solvent such as toluene and methyl ethyl ketone. Further, a blocked polyisocyanate in which an isocyanate group of the polyisocyanate is blocked by reacting a blocking agent such as a phenol, a tertiary alcohol, or a secondary alcohol with the above isocyanate compound can also be used.

Further, the surface of the filament in the tooth cloth is treated with an adhesive component such as an isocyanate, an epoxy resin, or RFL, by incorporating at least one kind of an antifriction material selected from graphite or molybdenum disulfide. It is present in a large amount at a position closer to the filament surface of the cloth, and is responsible for the wear resistance function of the tooth cloth after the fluororesin is worn and consumed, and the service life of the toothed belt is longer.

[0042]

Next, the present invention will be described specifically with reference to examples. The present invention is not limited to the embodiments, and can be appropriately modified without departing from the purpose. (Compounding of rubber constituting back part 3 and tooth part) Tables 1 and 2
The rubber composition 3a-1, 3a was kneaded for about 4 minutes using a Banbury mixer.
-2, 3a-3, 3a-4, 3a-5, 3a-6, 3a
-7 was obtained.

The obtained rubber compositions 3a-1, 3a-
2, 3a-3, 3a-4, 3a-5, 3a-6, 3a-
7 is rolled with an open roll, and is heated at 165 ° C for 30 minutes.
Press vulcanization was performed to obtain a vulcanized rubber sheet. The vulcanized rubber sheet excluding 3a-7 was subjected to a tensile test, a tear test, and the like according to JIS K6301, and the physical properties were measured. Table 1 shows the results.

[0044]

[Table 1]

[0045]

[Table 2]

(Tooth cloth 4) A coating fiber material having the composition and composition shown in Table 3 was prepared. Further, the RFL solutions shown in Table 4 were prepared to prepare pretreatment solutions. Further, the rubber compounds shown in Table 5 were kneaded. Further, the RFL treatment solutions shown in Tables 5 and 6 were prepared as pretreatment solutions. Thereafter, the woven fabric for a tooth cloth was immersed in the above pretreatment liquid, dried at 120 ° C, and then treated at 180 ° C for 2 minutes. Next, the rubber compound of Table 2 was added to ME
K, polyaryl polyisocyanate (trade name: PAPI) as an isocyanate compound after being dissolved in toluene
The fiber woven fabric after the RFL treatment was immersed in the treatment liquid to which the was added to form an adhesive layer. Further, the composition of Table 2 was prepared by adding ME
K (in the case of H-NBR) and toluene (in the case of other rubber components), and then, as an additive, add a fluororesin and other molybdenum disulfide, graphite, glass beads, etc. and mix them to obtain about 10% solid content. Was used as a uniform processing solution. Immerse the pretreated tooth cloth in this treatment liquid,
It was dried to obtain a treated tooth cloth material for preparing a belt.

[0047]

[Table 3]

[0048]

[Table 4]

[0049]

[Table 5]

Next, the above-mentioned tooth cloth was wound around a mold for forming a belt, and a pair of SZ-twisted RFLs shown in Table 6 and a core wire (glass fiber, 1.2 mm diameter) bonded with isocyanate were applied at a constant pitch ( (1.4 mm) and spirally wound with a constant tension.
a-2, 3a-3, 3a-4, 3a-5, 3a-6, 3
The sheet of a-7 was wound. Thereafter, this was pressurized by a normal pressure (press vulcanization at 160 ° C. for 30 minutes and molded) to obtain a cylindrical vulcanized molded product.

[0051]

[Table 6]

The size of the produced belt was 15 belt widths.
mm, belt tooth profile S8M (8.0 mm pitch), number of teeth 1
05, which is normally displayed as 150S8M840. Table 7 shows combinations of the materials of Examples 1 to 3 and Comparative Examples 1 to 4. Also, combinations of the materials of Examples 1 to 3 and Comparative Examples 1 to 4 are shown. Further, physical properties and jumping torque of the toothed belts obtained in Examples 1 to 3 and Comparative Examples 1 to 4 were measured, and the results are shown in Table 7. The tooth shearing force was measured by using the jig 13 shown in FIG. 4 and tightening the toothed belt A in the vertical direction at 9.8 N · cm per 1 mm of the belt width, and then pulling it upward in the direction of the arrow at a pulling speed of 50 mm / min. This was done by measuring the shear force of part 1. In FIG. 4, 14 is a fastening bolt, and 15 is a claw that engages with the tooth portion 1 of the toothed belt A.

In order to measure the adhesive strength of the tooth cloth, as shown in FIG. 5, the belt body A is gripped by one jig 13 and the tooth cloth 4 previously peeled off the belt body A by the other jig. After gripping, the tooth cloth 4 is pulled upward in the direction of the arrow at a pulling speed of 50 mm / min, and the average value of the force with which the tooth cloth 4 is continuously peeled off the belt body A is taken.

The jumping torque was measured by suspending a toothed belt between the driving pulley and the driven pulley.
The torque was measured when the toothed belt caused a tooth skipping phenomenon when rotating at a rotation speed of 600 rpm and applying torque to the driven pulley. Table 7 shows the measurement results.
Shown in The drive pulley has 24 teeth and a rotation speed of 3600r
pm, the driven pulley had 24 teeth, and the axial load of the toothed belt A when suspended between the driving pulley and the driven pulley was 147N.

[0055]

[Table 7]

From Table 7, it can be seen that at least the rubber layer constituting the tooth portion is composed of hydrogenated nitrile rubber and unsaturated metal salt of carboxylic acid.
It can be seen that Examples 1 to 3, which are formed of rubber composed of polymer components mixed at a mass ratio of 0:40 to 40:60, have a large jumping torque and a high transmission force.
Comparative Example 1 in which the amount of the unsaturated carboxylic acid metal salt is large has a low tooth cloth adhesive strength, and it can be seen that the tooth cloth may be peeled off while the belt is running. Further, it can be seen that Comparative Examples 2 and 3 in which the amount of the unsaturated carboxylic acid metal salt is small and Comparative Example 4 in which the rubber of the tooth portion is made of chloroprene rubber have a small jumping torque and a low transmission force.

As described above, the present invention has a plurality of teeth arranged at predetermined intervals along the longitudinal direction, and a back having a core wire buried therein. In the belt, at least the rubber layer constituting the tooth portion is made of a hydrogenated nitrile rubber and an unsaturated carboxylic acid metal salt at 60:40 to 4-4.
With the rubber formed of the polymer component mixed at a mass ratio of 0:60, the teeth are accurately formed,
An increase in the jumping torque has the effect of improving the transmission force of the belt.

Further, the present invention further comprises impregnating and coating a first adhesive component with the rubber layer so that the front and back surfaces and the inside of the tooth cloth are in communication with each other, and the first adhesive component contains graphite or molybdenum disulfide. By including at least one kind of anti-friction material selected from among the above, even if the wear of the tooth cloth extends to the vicinity of the fiber, the wear of the tooth cloth does not progress further and the toothed belt There is an effect that durability is improved.

Further, the tooth cloth provided with the first adhesive component is coated with a second rubber composition as the rubber layer.
A fluororesin is dispersed in the rubber composition without being bonded to the second rubber composition, and the second rubber composition and the first rubber composition constituting the teeth and the back are vulcanized. Since it is a toothed belt integrated by pressure, there is a rubber layer containing fluorine resin on the sliding surface in contact with the pulley, so that the initial wear of the belt is small and the durability of the toothed belt is improved. There is.

Further, in the present invention, the rubber layer comprises a hydrogenated nitrile rubber and an unsaturated carboxylic acid metal salt in a ratio of 60:40.
It is formed of a rubber crosslinked by blending 0.2 to 10 parts by mass of an organic peroxide with 100 parts by mass of a polymer component mixed at a mass ratio of ４０40: 60. In addition, since it is formed of rubber compounded with 5 to 50 parts by mass of carbon black, the teeth are formed accurately, the jumping torque is stabilized at a high numerical value, and the transmission power of the belt is stably improved. .

[Brief description of the drawings]

FIG. 1 is a perspective view showing the entire structure of a toothed belt of the present invention.

FIG. 2 is an enlarged sectional view showing a structure of a main part of the toothed belt of the present invention.

FIG. 3 is an enlarged photograph of a part of a tooth cloth of the toothed belt of the present invention.

FIG. 4 is a front view showing a belt shearing force measuring jig.

FIG. 5 is a schematic view showing a state of measurement of a tooth cloth adhesive force.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tooth part 2 Core wire 3 Back part 4 Tooth cloth 5 Second rubber composition 6 Fluororesin 7 Weft 8 Warp 9 First rubber composition 10 Gap 11 Boundary surface 12 Lubricant 13 First adhesive component 14 Fastening bolt 15 Nail

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29K 19:00 B29K 19:00 35:00 35:00 F-term (Reference) 3F024 AA01 AA03 AA07 AA11 BA05 CA04 CA08 DA03 4F213 AA16 AA30 AA45 AB11 AB18 AB19 AD15 AD16 AG17 AH12 WA04 WA14 WA15 WA53 WA58 WA87 WB01 WB18

Claims (12)

[Claims] 1. A toothed belt having a plurality of tooth portions arranged at predetermined intervals along a longitudinal direction and a back portion in which a core wire is embedded, the toothed belt being covered with a tooth cloth having a rubber layer on a surface of the tooth portion. The first rubber composition constituting at least the tooth portion is composed of a hydrogenated nitrile rubber and an unsaturated metal carboxylate at 60:40.
A toothed belt made of rubber composed of polymer components mixed at a mass ratio of ４０40: 60. 2. A method of impregnating and coating a first adhesive component with the rubber layer so that the front and back surfaces and the inside of the tooth cloth communicate with each other, and the first adhesive component includes graphite or molybdenum disulfide. A second cloth composition is coated as the rubber layer on the tooth cloth to which at least one selected anti-friction material is contained and the first adhesive component is provided, and a fluororesin is contained in the second rubber composition. Are dispersed without being bonded to the second rubber composition, and the second rubber composition and the first rubber composition constituting the teeth and the back are integrated by vulcanization and pressurization. 2. The toothed belt according to 1. 3. A first adhesion to the rubber layer containing at least one kind of anti-friction material selected from graphite or molybdenum disulfide such that the front and back surfaces and the inside of the tooth cloth are in communication with each other. Component is impregnated and further coated on the tooth cloth provided with the first adhesive component as the rubber layer.
The rubber composition is coated, and 50 to 400 parts by weight of the fluororesin is added to the second rubber composition based on 100 parts by weight of the rubber in the second rubber composition without being bonded to the second rubber composition. The fluororesin is not bonded to the second rubber composition, and the second rubber composition is directly bonded to the first rubber composition constituting the teeth and the back part. 2. The toothed belt according to claim 1, wherein the belt is connected. 4. The front and back surfaces and the inside of the tooth cloth are impregnated and coated with a first adhesive component with the rubber layer, and the first adhesive component contains at least one kind selected from graphite or molybdenum disulfide. A second rubber composition is coated as the rubber layer on the tooth cloth further including the anti-friction material and further provided with the first adhesive component, and a fluororesin is added to the second rubber composition in the second rubber composition. 100 to 2 parts by weight of rubber
The fluorocarbon resin is not bonded to the second rubber composition, and the second rubber composition is combined with the second rubber composition, and the first rubber composition constituting the teeth and the back is added. The toothed belt according to claim 1, wherein the belt is directly connected to an object. 5. The toothed belt according to claim 3, wherein the composition is applied in an amount of 7 to 40% by weight based on the weight of the tooth cloth before the adhesive treatment. 6. The first rubber composition comprises a hydrogenated nitrile rubber and an unsaturated metal carboxylate in a ratio of 60:40 to 40: 6.
The rubber composition according to any one of claims 1 to 5, wherein the rubber composition is formed of a rubber crosslinked by blending 0.2 to 10 parts by mass of an organic peroxide with respect to 100 parts by mass of a polymer component mixed at a mass ratio of 0. Toothed belt. 7. The toothed belt according to claim 6, further comprising 5 to 50 parts by mass of carbon black in addition to the organic peroxide. 8. Between the second rubber composition and the first adhesive component, or across the second rubber composition and the first adhesive component,
The toothed belt according to any one of claims 2 to 7, wherein a tooth cloth adhesive layer is provided by interposing a rubber compound containing an isocyanate compound as the second adhesive component. 9. The toothed belt according to claim 8, wherein the fluororesin is in a powder form, and the powder has an average diameter of 0.1 to 500 μm. 10. The toothed belt according to claim 2, wherein a lubricant other than the fluororesin is added to the second rubber composition of the tooth cloth. 11. The second rubber composition of the tooth cloth and the first rubber composition of the tooth portion and the back portion are the same.
11. The toothed belt according to any one of items 1 to 10. 12. The graphite and molybdenum disulfide are in the form of powder, and both have a particle size of 0.01 to 50.
The toothed belt according to any one of claims 2 to 11, which has a thickness of 0 µm.