JP2001208137A - Toothed belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toothed belt coated with tooth cloth, improved in wear resistance and chipping resistance by making fluororesin in such a form as to easily exhibit a friction coefficient reducing action to be contained in a large quantity in rubber composition coated on a tooth cloth by impregnation, and containing an anti-friction material in an adhesive component between the rubber composition and the tooth cloth. SOLUTION: This toothed belt is so constructed that a rubber layer 2 constituting a back part 3 is formed in a double structure, at least an outer layer 3a of the two-layer structure uses rubber with higher hardness than an inner layer 3b, a first rubber composition 5 is coated by impregnation to put the surface and obverse of the tooth cloth 4 and the inside thereof in the mutually connecting state, and a first adhesive component 13 of the first rubber composition 5 containing at least one kind of anti-friction material selected from graphite and molybdenum disulfide is applied to a yarn constituting the tooth cloth 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camshaft of an automobile engine and a drive of an injection pump.
Synchronous conduction of general industrial machines, toothed belts coated with tooth cloth used for small-sized machines that require precise positioning accuracy, especially improved wear resistance and chipping resistance About things.

[0002]

2. Description of the Related Art Toothed belts that simultaneously drive a camshaft, an injection pump, an oil pump, and a water pump of an automobile engine have been used under ever-increasing conditions due to the high output of the engine and the compact engine rules. It has become severe, and further improvement in durability has been required. Synchronous transmission toothed belts used in general industries and transported toothed belts used in small machines that require precise positioning accuracy are also required to extend the belt replacement cycle. I have.

[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]

[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 interior 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. Also, in order to maintain the strength without fibrillating the fluororesin to form foreign matter, it can contain only about 1 to 30 parts by weight of the fluororesin per 100 parts by weight of the rubber impregnated in the tooth cloth, There is a problem that the improvement of the tooth chipping resistance is not sufficient.

The present invention has been made in view of the above-mentioned problems, and comprises a rubber composition which is impregnated and coated on a tooth cloth, in which a large amount of a fluorine resin is contained in a form in which the effect of reducing the coefficient of friction is easily exhibited. An object of the present invention is to provide a toothed belt covered with a tooth cloth with improved wear resistance and tooth chipping resistance.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a method of fabricating a warp or a weft yarn which comprises a fluororesin which is not bonded to a rubber composition to be impregnated and coated on a tooth cloth. By dispersing and dispersing to a portion close to the filament, it is possible to contain a large amount of fluororesin, and the opportunity for the fluororesin to be exposed to the friction surface is increased, and the effect of reducing the friction coefficient by the fluororesin can be surely exhibited. It was completed with the knowledge that

[0008] That is, a first invention is a toothed belt having a plurality of teeth arranged at predetermined intervals along a longitudinal direction, and a back having a core wire embedded therein, the surface of which is covered with a tooth cloth. In the above, the rubber layer constituting the back part is formed in a two-layer structure,
At least the outer layer of the two-layer structure uses a rubber of higher hardness than the inner layer, impregnated and coated with a first rubber composition so that the front and back surfaces and the inside of the tooth cloth are in communication with each other,
Fluororesin is dispersed in the first rubber composition without being bonded to the first rubber composition, and at least one of graphite and molybdenum disulfide selected from the group consisting of graphite and molybdenum disulfide An adhesive component with the first rubber component containing a kind of anti-friction material is provided, and the first rubber composition and the second rubber composition constituting the tooth portion and the back portion are integrated by vulcanization and pressurization. It is characterized by having done. Since the rubber layer constituting the back portion is formed in a two-layer structure, and at least the outer layer of the two-layer structure is made of a rubber having higher hardness than the inner layer, the outer layer of the back portion has a high hardness rubber. The abrasion resistance can be enhanced by the outer layer on the back surface. When the first rubber composition is impregnated and coated so that the front and back surfaces and the inside of the tooth cloth are in communication with each other, the fluororesin not bonded to the first rubber composition is entangled with the filament constituting the tooth cloth. And a large amount of fluororesin can be contained. When an adhesive component with the first rubber composition containing molybdenum disulfide is included in the tooth cloth, the first rubber composition holding the fluororesin penetrates around the fibers constituting the tooth cloth, resulting in a large amount of the rubber composition. Fluororesin can be entangled with the tooth cloth. Further, graphite or molybdenum disulfide is added to the first adhesive component by adding at least one kind of anti-friction material selected from graphite or molybdenum disulfide to the fiber woven fabric and the front and back surfaces of each fiber constituting the same. It can be focused, and as a result, a large amount of fluororesin and graphite or molybdenum disulfide can be entangled with the tooth cloth.

A second invention provides a toothed belt having a plurality of teeth arranged at predetermined intervals in a longitudinal direction and a back having a core wire embedded therein, the surface of the teeth being covered with a tooth cloth. In, the rubber layer constituting the back portion is formed in a two-layer structure, using a rubber of higher hardness than the inner layer at least the outer layer of the two-layer structure, on the front and back and inside of the tooth cloth, 5 parts by weight of fluororesin to 100 parts by weight of rubber in the first rubber composition
Attach the compound dispersed by adding 0 to 400 parts by weight or the compound dispersed by adding 100 to 250 parts by weight of the powdery fluororesin to 100 parts by weight of the rubber in the first rubber composition. And further applying a first adhesive component to the first rubber component containing at least one kind of anti-friction material selected from graphite or molybdenum disulfide to the yarn constituting the tooth cloth, Is characterized in that the first rubber composition is directly bonded to the second rubber composition constituting the teeth and the back without being bonded to the first rubber composition. Then, preferably, the composition is applied in an amount of 7 to 40% by weight based on the weight of the tooth cloth before the application treatment.
More preferably, the outer layer of the two-layer structure is 100%
Physical properties such that the modulus at the time of extension is 4.5 MPa or more, 1.0 MPa or more larger than that of the rubber of the inner layer, the elongation at the time of cutting is 400% or more, and the hardness of the rubber of the inner layer is at least 3 degrees. Is a toothed belt made of rubber having the following.

[0010] Further, the outer layer of the rubber layer having a two-layer structure constituting the back portion is a polymer component 100 obtained by mixing a hydrogenated nitrile rubber and an unsaturated metal carboxylate in a weight ratio of 98: 2 to 55:45. Organic peroxide 0.2 parts by weight
It is preferable that the rubber is formed of a crosslinked rubber containing 10 to 10 parts by weight. More preferably, between the first rubber composition and the first adhesive component, or between the first rubber composition and the first adhesive component.
A rubber compound containing an isocyanate compound as a second adhesive component is interposed over the adhesive component to provide an adhesive layer for a tooth cloth. More preferably, the fluororesin is made into a powder and the powder has an average powder diameter of 0.1. 1 to 500 μm. Since the rubber layer constituting the back portion is formed in a two-layer structure, and at least the outer layer of the two-layer structure is made of a rubber having higher hardness than the inner layer, the outer layer of the back portion has a high hardness rubber. The abrasion resistance can be enhanced by the outer layer on the back surface. 50 to 4 parts by weight of a fluororesin that does not bind to the first rubber composition is added to 100 parts by weight of the first rubber composition.
When it is contained in such a large amount as to be 00 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 anti-friction material other than the fluororesin, or the first rubber composition of the tooth cloth may be used. It is preferable that the second 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. Further, the inner layer of the rubber layer having the two-layer structure constituting the back surface is composed of 100 parts by weight of hydrogenated nitrile rubber having a hydrogenation rate of 90 to 98% and carbon black 1 layer.
It is preferably formed of a crosslinked rubber containing 0 to 80 parts by weight, 2 to 15 parts by weight of a plasticizer, and 0.2 to 10 parts by weight of an organic peroxide. When a friction coefficient reducing agent other than the fluororesin is added to the first rubber composition, the effect of reducing the friction coefficient by both the fluororesin and the friction coefficient reducing agent is exhibited. When the first rubber composition of the tooth cloth and the second rubber composition of the belt body are made of the same quality, even if the first rubber composition of the tooth cloth contains a large amount of unbonded fluororesin, the first rubber composition And the second rubber composition can be secured. Further, the inner layer of the rubber layer having the two-layer structure constituting the back portion is formed with a hydrogenation rate of 90 to
A rubber crosslinked by mixing 10 to 80 parts by weight of carbon black, 2 to 15 parts by weight of a plasticizer, and 0.2 to 10 parts by weight of an organic peroxide with respect to 100 parts by weight of 98% hydrogenated nitrile rubber. Therefore, the rubber having the hardness and the modulus of physical properties necessary for improving the quietness and the life can be formed, and the rubber of the inner layer on the back surface can be formed.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an enlarged sectional view of a tooth cloth,
FIG. 2 is a diagram showing the entire structure of the toothed belt of the present invention. In FIG. 2, a toothed belt A includes a plurality of tooth portions 1 arranged at predetermined intervals along a longitudinal direction, a back portion 3 continuous with the tooth portions 1, and a core wire 2 embedded in the back portion 3. It is a structure having a tooth cloth 4 coated on the surface of the tooth portion 1. The back part 3 and the teeth part 1 constitute a belt body formed of the second rubber composition 9. The tooth cloth 4 is 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 portion 3 and the tooth portion 1 are formed of a rubber layer. The rubber layer constituting the back portion 3 is formed of an outer layer (the side opposite to the tooth portion 1) 3a and an inner side (the tooth portion 1 side). Is formed in a two-layer structure of the layer 3b.

In the present invention, the rubber constituting the outer layer 3a of the back portion 3 is a mixture of hydrogenated nitrile rubber and an unsaturated metal carboxylate in a weight ratio of 98: 2 to 55:45. A rubber crosslinked by blending 0.2 to 10 parts by weight of an organic peroxide with respect to 100 parts by weight of a polymer component, and having a modulus at 100% elongation (tensile modulus M100) of 4.5 MPa or more. In addition, a rubber having an elongation at the time of cutting of 400% or more is used.

The rubber of the outer layer 3a of the back part 3 is 100
If the modulus at% elongation is less than 4.5 MPa, the rubber cannot withstand the rubber deformation due to stress when the toothed belt comes into contact with a tension pulley, an idler pulley, or the like. In addition, the wear resistance and crack resistance are reduced and the life of the belt is shortened. Further, when the elongation at the time of cutting is less than 400%, cracks due to bending are easily generated, and the life of the belt is shortened. For this reason, in the present invention, as described above, the modulus of the rubber at the time of 100% elongation is 4.5 MPa or more and the elongation at the time of cutting is 4 MPa as the rubber of the layer 3 a outside the back surface portion 3.
When the modulus at 100% elongation exceeds 10 MPa, it is difficult to adjust the elongation at cutting to 400% or more, so the modulus at 100% elongation is 4.5. It is preferable to adjust the elongation so as not to deviate from the range of 10 to 10 MPa.

The hydrogenated nitrile rubber used for the rubber constituting the outer layer 3a of the back surface 3 needs to have a hydrogenation rate of at least 90% from the viewpoint of heat resistance. ~ 98% is preferred. The modulus (tensile modulus) is increased by compounding a metal salt of an unsaturated carboxylic acid with the hydrogenated nitrile rubber. In order to ensure a higher tear strength, the hydrogenated nitrile rubber and the unsaturated metal salt of a carboxylic acid are used in a ratio of 98: 2 to 55:
It is necessary to mix at a weight ratio of 45. The unsaturated carboxylic acid metal salt is not particularly limited,
Zinc acrylate, zinc methacrylate, or the like can be used. Although it is possible to increase the modulus (tensile modulus) by reinforcing with carbon black without using a metal salt of an unsaturated carboxylic acid, the elongation at break and tear strength of rubber are reduced, and deformation and deformation of rubber are caused. It is not preferable because sufficient durability against generation of cracks due to bending cannot be provided.

The above-mentioned organic peroxide compounded in the polymer component comprising the hydrogenated nitrile rubber and the metal salt of unsaturated carboxylic acid is used as a crosslinking agent, and has a modulus (tensile modulus of elasticity) of the above-specified values. ) And breaking elongation, it is necessary to crosslink by blending 0.2 to 10 parts by weight of an organic peroxide with respect to 100 parts by weight of the polymer component as described above. Although it does not specifically limit as an organic peroxide, For example, 1,1- di-t
-Butylperoxy-3,3,5-trimethylcyclohexane, di-t-butyl peroxide, dibutylcumyl 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 the above, carbon black, a plasticizer, and the like are appropriately added within a range that ensures the modulus (tensile elastic modulus) and elongation at break to the above-specified values and secures an appropriate tear strength. You can also. It is preferable to mix 5 to 50 parts by weight of carbon black and 2 to 15 parts by weight of a plasticizer with respect to 100 parts by weight of a polymer component comprising a hydrogenated nitrile rubber and a metal salt of an unsaturated carboxylic acid.
As the plasticizer, a trimellitic acid-based, polyester-based, polyether-based, or phthalic acid-based plasticizer having excellent heat resistance can be used.

On the other hand, in the present invention, the rubber constituting the inner layer 3a of the back surface 3 is a hydrogenation rate of 90 to 98.
% Of hydrogenated nitrile rubber, 100 parts by weight of carbon black, 10 to 80 parts by weight of carbon black, 2 to 15 parts by weight of plasticizer,
A rubber cross-linked by mixing 0.2 to 10 parts by weight of an organic peroxide is used, and the tooth portion 1 is also integrally formed of the same rubber as the inner layer 3a of the back surface portion 3. .
As the plasticizer and the organic peroxide, those described above can be used.In addition to these, sulfur compounds, oxime nitroso compounds, and monomers and polymers are commonly used as co-crosslinking agents. Can be added in an appropriate amount.

Since the outer layer 3a of the back portion 3 is formed of rubber having a high modulus and a high hardness as described above, there is a possibility that the vibration of the belt may generate noise and shorten the life. For this reason, by using a rubber having a lower modulus and a lower hardness than the rubber of the outer layer 3a as the rubber constituting the inner layer 3b of the back part 3, it is possible to suppress the generation of sound and the shortening of the life due to the vibration of the belt. The hardness of the rubber constituting the inner layer 3b of the back surface portion 3 is 60 to 75.
The hardness must be in the range of degrees (the modulus at 100% elongation is 2.5 to 6.5 MPa), and the hardness is more preferably 65 to 70 degrees (the modulus at 100% elongation is 3.
0 to 5.0 MPa). If the hardness of the rubber forming the inner layer 3b of the back surface portion 3 is less than 60 degrees, the deformation of the tooth portion 1 when the toothed belt meshes with the pulley may be large, and the life may be shortened. If it exceeds 75 degrees, there is a possibility that the generation of sound due to the vibration of the belt may increase.
In the present invention, the hardness of the rubber is JIS K630.
JIS K6 using the spring hardness meter described in 1.
It is a hardness measured according to the method specified in 301.

By adopting the above rubber composition as the rubber constituting the inner layer 3b of the back part 3, the hardness and modulus (tensile elastic modulus) of the rubber of the back part 3 are set to the physical properties within the above ranges. What forms the inner layer 3b can be formed. The hardness and modulus (tensile modulus) of the rubber constituting the inner layer 3b of the back surface portion 3 are set in the above ranges. In order to obtain crack resistance, the rubber constituting the outer layer 3a of the back surface 3 has a higher modulus (tensile modulus) than the rubber of the inner layer 3b.
Is set to be higher than 1.0 MPa and the hardness is higher than 3 degrees. It is preferable to use a material in which the modulus (tensile modulus) of the rubber of the outer layer 3a and the inner layer 3b of the back portion 3 is set to be higher than 1.0 MPa and the hardness is higher than 3 degrees. The upper limit of the difference between the modulus (tensile elastic modulus) and the difference in hardness of the rubber of the outer layer 3a and the inner layer 3b of the back portion 3 is not particularly set. Upper limit is 7M
It is preferable that the upper limit of the difference in hardness is about 15 Pa or so.

As shown in FIG. 1, a first rubber composition 5 mainly composed of rubber is impregnated and coated on the front, back and inside of a tooth cloth 4 formed by weaving a weft 7 and a warp 8. A powdery fluororesin 6 is dispersed and disposed inside the rubber composition 5. And the fluororesin 6 and the 1st rubber composition 5 are not couple | bonded, and the clearance gap 10 is formed in all or one part of the circumference | surroundings. Further, the tooth portion 1 and the back surface portion 3 covered with the tooth cloth 4 are formed of a second 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 frictional action, the fluororesin 6 contained in the first rubber composition 5 is largely exposed to the friction surface, and effectively exerts a friction coefficient reducing action. Further, when the fluororesin 6 is powdered, a large amount of the fluororesin 6 is blended so as to be entangled with the weft 7 and the warp 8 constituting the tooth cloth 4, and the fluororesin 6 can be supplied in a large amount to the friction surface of the tooth cloth 4.
Further, the first rubber composition 5 of the tooth cloth 4 is chemically bonded to the second rubber composition 9 of the belt body (tooth portion 1 and back surface portion 3) by heat vulcanization or the like. Even if a large amount of the powdery fluororesin 6 is mixed with the object 5, the interface 11 between the tooth cloth 4 and the belt body is firmly joined.

Further, a large amount of graphite 12 is contained in an adhesive component 13 for adhering the tooth cloth 4 and the first rubber component. . As the action of the fluorine resin present in the first rubber component and the graphite present in the adhesive component, first, the first rubber component having the contact surface 14 with the pulley is worn by friction with the pulley. However, since the fluororesin is dispersed in the first rubber component, the friction coefficient is smaller than that in the case where no fluororesin is present, so that the first rubber composition is excellent in abrasion resistance and wear of the first rubber composition is slow. . Furthermore, even if the first rubber composition is worn out and disappears, the adhesive component 13 containing graphite 12 exists around the tooth cloth 4 and appears on the sliding surface with the pulley surface. The wear resistance of the surroundings of the toothed belt 4 is also excellent, and the wear of the tooth cloth 4 can be extremely delayed as compared with the conventional belt, and thus 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.

The weft 7 and the warp 8 constituting the tooth cloth 4 are made of nylon, aramid, polyester,
Any or a combination of polybenzoxazole fibers can be employed. 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. A spun yarn or a yarn in which filaments are gathered to such an extent that the first rubber composition 5 can be impregnated inside the fiber is preferable. In addition, since the aramid fiber or the polybenzoxazole fiber is a fiber having a low coefficient of friction itself, by including at least the weft 7 in the belt longitudinal direction, the tooth chipping resistance is improved.

The woven structure of the tooth cloth may be twill weave, satin weave, plain weave, or the like.
2 can be included in large quantities. In order for the first rubber composition 5 in which the fluororesin 6 is dispersed to be effectively impregnated and coated on the tooth cloth 4, the first rubber composition 5 is in a state of being in communication with each other on the front and back surfaces and inside of the tooth cloth 4. Select the fiber thickness and density.

First rubber composition 5 impregnated and coated on tooth cloth 4
The rubber of the same kind as that of the rubber of the second rubber composition 9 constituting the belt body of the tooth part and the back part is selected. Depending on the use environment, automotive engines and toothed belts for various types of engines include, as rubbers of the first rubber composition and the second rubber composition, hydrogenated nitrile rubber (H-NBR) having heat resistance and oil resistance, and chloroprene. (CR), chlorosulfonated polyethylene (CSM) and the like are used. Using the second rubber composition using any rubber for the back and teeth,
In addition, a toothed belt using tooth cloth treated as a treatment liquid by adding a first rubber composition using the same type of rubber to a rubber paste and adding a fluororesin as a treatment liquid, in the case of any of the rubber compositions, a fluororesin-added Great effect. However, other rubbers used for toothed belts used in other general industrial machines, such as acrylonitrile butadiene copolymer (N
BR), ethylene propylene diene monomer (EPD)
M), ethylene propylene copolymer (EPR), styrene butadiene copolymer (SBR), isoprene rubber (I
R), natural rubber (NR), acrylic rubber, fluoro rubber,
Similarly, in any case such as silicon rubber, the use of a fluororesin for the treatment of tooth cloth has the effect of improving the life of missing teeth. In particular, the hydrogenated nitrile rubber preferably has a hydrogenation rate of 80% or more, and more preferably 90% or more, in order to exhibit heat resistance and ozone resistance characteristics. A hydrogenated nitrile rubber having a hydrogenation rate of less than 80% has extremely low heat resistance and ozone resistance.

In the first rubber composition, carbon black, zinc white, stearic acid, a plasticizer, an antioxidant and the like are added to the rubber as a compounding agent, and sulfur and an organic peroxide are used as a vulcanizing agent. It is added. The content of these compounding agents, vulcanizing agents, and the like may be determined according to a conventional method, and is not particularly limited.

The fluororesin 6, which does not bind to the rubber of the first rubber composition impregnated and coated on the tooth cloth 4, is polytetrafluoroethylene, polytrifluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene. -One or more of perfluoroalkoxyethylene copolymer and tetrafluoroethylene-ethylene copolymer. These fluororesins 6 are powdered by granulation or crushing, and have an average particle diameter of 500 μm or less. The effect of attaching the fluororesin 6 to a position close to the surface of the fiber filaments constituting the weft and the warp of the tooth cloth 4 to reduce the friction coefficient at the time of engagement between the toothed belt and the pulley and extending the life of the belt is as follows. The effect increases as the ratio of the number of fluorine atoms in the film increases. Therefore, assuming the same amount of adhesion to the tooth cloth, the fluororesin 6
Among them, polytetrafluoroethylene is the most effective in reducing the friction coefficient and has a long tooth chipping life. However, other fluororesins also have an effect substantially in proportion to the ratio of the number of fluorine atoms in the molecule. The form of the powder of the fluororesin is not particularly limited, but is dispersed in the rubber composition in a state of a powder pulverized or granulated to an average diameter of 500 μm or less. If the diameter exceeds 500 μm, the surface area of the fluororesin 6 in the belt decreases and the effect is reduced. When the diameter is 0.1 μm, the powder is excessively dispersed, and the chance of exposure to the friction surface is reduced. In particular, a fluororesin having a small particle diameter of 3 to 30 μm obtained by emulsion polymerization, suspension polymerization or the like has a large effect of reducing the friction coefficient.

The specific method for attaching the fluororesin 6 to the tooth cloth 4 is as follows. After kneading the first rubber composition, the first rubber composition is mixed with methyl ethyl ketone (ME
K), and dissolved in a solvent such as toluene, and the fluororesin 6 was added in an amount of 50 to 400 with respect to 100 parts by weight of the rubber in the first rubber composition.
A part by weight is added and uniformly dispersed to obtain a treatment liquid. The cloth 4 is immersed in the treatment liquid and dried, and the amount of the mixture of the fluororesin 6 and the rubber composition is set to 7 based on the weight of the cloth 4 before the immersion treatment.
It is used for producing a belt as about 40% by weight. In addition, a dispersion of fluororesin 6 in water is mixed in a resorcinol-formalin rubber latex mixture, and the fabric for a tooth cloth is immersed, dried and heat-treated, and the surface of the tooth cloth, the back side, and the surface of the fiber filament inside the tooth cloth are mixed. Can be used.

In order for the effect of improving the performance of the toothed belt to travel under high load conditions to be recognized as the amount of fluorine added, 50 parts by weight of the fluororesin 6 is required for 100 parts by weight of the rubber in the rubber composition. The effect is small if no part is added. On the other hand, when the amount of the added fluororesin exceeds 400 parts by weight based on 100 parts by weight of the rubber of the rubber composition, the adhesiveness of the tooth cloth is reduced, and the belt performance is reduced. The preferred addition amount is rubber 1
More than 100 parts by weight and not more than 250 parts by weight with respect to 00 parts by weight.

As a method for measuring the amount of the composition comprising the fluororesin powder and the rubber composition attached to the tooth cloth,
The mass of the pretreated tooth cloth is weighed and the mass (W1) is measured. Next, the pretreated tooth cloth is immersed in the treatment solution in which the above-mentioned composition is dissolved, and then the cloth is put into an oven and dried until the weight becomes constant, and the final weight (W2) is measured. , ((W2−W1) / W1) × 100 (%).

Further, the amount of adhesion of the blend of the fluororesin and the rubber composition is at least 7% with respect to the weight of the tooth cloth before the impregnation.
If it is not more than 10% by weight, the adhesive strength is low and the total amount of the adhered amount of the fluororesin 6 is small, so that the effect of improving the belt performance is small,
If the content exceeds 0% by weight, the rigidity of the tooth cloth increases, and it becomes difficult to mold the tooth profile during vulcanization. The preferred amount of adhesion is 15 to 25% by weight based on the weight of the tooth cloth before the impregnation treatment.

Further, together with the fluororesin 6, one or more of molybdenum disulfide, layered graphite, glass beads, ceramic powder, spherical phenol resin powder and aramid, polyamide, polyester, polybenzoxazole, fiber cut yarn or powder are used. It is preferable to add the rubber composition dissolved in a solvent to the rubber paste and mix and disperse the mixture. Then, after immersing the tooth cloth and drying it, it is preferable to adhere to the tooth cloth by vulcanization at the time of producing the belt and to integrate it with the belt body. By further adding these friction coefficient reducing agents, the effect of reducing the friction coefficient is enhanced as compared with using the fluororesin 6 alone, and the durability of the belt is further improved. In particular, molybdenum disulfide and graphite having a layered structure have been conventionally used as a sliding agent. When used together with the fluororesin 6, the stress applied to the bottom of the belt tooth due to friction at the time of engagement between the pulley and the belt is further reduced. .

Further, the adhesiveness of the rubber composition impregnated and coated on the tooth cloth 4 is improved, and a fluororesin is adhered to a portion of the tooth cloth 4 close to the surface of the warp threads. In order to obtain an improved bonding property, it is preferable that the fiber used for the tooth cloth 4 is subjected to a treatment for providing an adhesive component. 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 placed in an oven adjusted to 150 to 190 ° C. for 2 to 5 minutes. Through and dry. 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 first 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 an effect of preventing 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.

As the isocyanate compound used in the above pretreatment liquid, for example, 4,4'-diphenylmethane diisocyanate, tolylene 2,4-diisocyanate, polymethylene polyphenyl diisocyanate, hexamethylene diisocyanate, 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 a polyalkylene glycol such as polyethylene glycol with a halogen-containing epoxy compound such as epichlorohydrin. And products of reaction with polyhydric phenols such as resorcin, pis (4-hydroxyphenyl) dimethylmethane, phenol, formaldehyde resin, resorcin and formaldehyde resin, and halogen-containing epoxy compounds. 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 liquid 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 weight with respect to 100 parts by weight of rubber of rubber latex, and the total solid concentration is 5 to 100 parts by weight. 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 woven fabric for a 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 first 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.

The core 1 used for the belt having the fluororesin 6 adhered to the tooth cloth 4 is not limited. Generally, a glass core and an aramid core are 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 converging filaments, and the number of strands. Further, the present invention is not limited to a sizing agent, an RFL, an overcoat agent, and the like used as an adhesive treatment agent and a protective material for a glass filament during bending. 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.

The toothed belt having the above-described structure is the first type.
Friction during running of the belt by dispersing a large amount of fluororesin powder that does not bind to the rubber composition in the rubber composition at a position very close to the surface of the tooth cloth, the back surface, and the surface of the fiber filament inside the toothed belt. The coefficient is continuously reduced during running to improve tooth chipping resistance. The shape of the fluororesin differs depending on the pulverization method or the granulation method, but any shape may be used, and it is not necessary that the fluororesin be polytetrafluoroethylene having a property of forming a fiber by mixing and kneading in rubber. Rather, a fluororesin having a small particle diameter that is difficult to form fibers has a greater effect. By adding a large amount of the rubber composition to the rubber paste dissolved in a solvent, the fluororesin is present in a large amount in the paste rubber in a state of being dispersed in the rubber composition, and the tooth cloth is immersed, dried, and added. Upon vulcanization, the adhesive strength to the belt body is increased by bonding the adhesive components such as isocyanates, epoxy resin, RFL, etc., which have been previously treated on the surface of the filament in the tooth cloth, to the rubber composition excluding the fluororesin, and the strong adhesive force to the tooth cloth Can be obtained. In this case, the fluororesin is not directly bonded to the rubber composition, but the effect is continuously exerted during running due to the presence of a large amount at a position very close to the surface of each single filament of warp and weft constituting the tooth cloth. I do.

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, in which at least one kind of anti-friction material selected from graphite or molybdenum disulfide is contained. It is present in a large amount at a position closer to the filament surface of the cloth, and is responsible for the abrasion resistance function of the tooth cloth after the fluororesin is worn out and consumed, and the life of the toothed belt is longer.

[0045]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples, and can be appropriately changed without departing from the object. (Blending of Rubber Constituting Layer 3a Outside Back Side 3) Table 1
The rubber composition 3a-1, 3a was kneaded for about 4 minutes using a Banbury mixer.
-2, 3a-3 and 3a-4 were obtained.

The obtained rubber compositions 3a-1, 3a-
2, 3a-3 and 3a-4 are rolled by open rolls,
Press vulcanization was performed at 65 ° C. for 30 minutes to obtain a vulcanized rubber sheet. JIS K 630 for this vulcanized rubber sheet
A tensile test, a tear test, and the like were performed in accordance with Example 1, and the physical properties were measured. Table 1 shows the results.

[0047]

[Table 1]

(Blending of the rubber constituting the inner layer 3b of the back part 3 and the tooth part 1) The compound shown in Table 2 was kneaded for about 4 minutes using a Banbury mixer to obtain a rubber composition 3b- 1, 3b-2, 3b-3, and 3b-4 were rolled with open rolls and press-vulcanized at 165 ° C. for 30 minutes to obtain a vulcanized rubber sheet. The vulcanized rubber sheet was subjected to a tensile test, a tear test, and the like according to JIS K6301, and the physical properties were measured. Table 2 shows the results.

[0049]

[Table 2]

(Tooth cloth 4) A coating fiber material having the composition and composition shown in Table 3 was prepared. Further, the rubber compounds shown in Table 4 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, MEK,
The fiber woven fabric after the RFL treatment was immersed in a treatment solution in which a polyaryl polyisocyanate (trade name: PAPI) was added as an isocyanate compound after being dissolved in toluene to form an adhesive layer. Further, the composition shown in Table 2 was added to MEK (H
-In the case of NBR), dissolved in toluene (in the case of other rubber components), and then mixed with a fluororesin and other molybdenum disulfide, graphite, glass beads, etc. as additives, and uniformly mixed at about 10% solids. Treatment solution. The pretreated woven fabric for a tooth cloth was immersed in the treatment liquid and dried to obtain a treated tooth cloth material for forming a belt.

[0051]

[Table 3]

[0052]

[Table 4]

[0053]

[Table 5]

[0054]

[Table 6]

Next, the above-mentioned tooth cloth was wound around a mold for forming a belt, and a core wire (glass fiber, 1.2 mm diameter) bonded to a pair of SZ twisted RFL and isocyanate shown in Table 7 was applied at a constant pitch ( (1.4 mm), and spirally wound with a constant tension.
b-2, 3b-3, and 3b-4, and the rubber compositions 3a-1, 3b-2, 3b-3, and 3
b-4, and the rubber composition 3 of Table 1
Sheets a-1, 3a-2, 3a-3, and 3a-4 were wound. Thereafter, this is pressurized by a normal press-fitting method (1).
(Pressure vulcanization at 60 ° C. for 30 minutes and molding) to obtain a cylindrical vulcanized molded product. The two types of rubber sheets shown in Tables 1 and 2 can be used by being bonded in advance.

[0056]

[Table 7]

The size of the produced belt was 15 belt widths.
mm, belt tooth shape Y (8.0 mm pitch), number of teeth 105
And usually displayed as 105Y15. Table 8 shows combinations of the materials of Examples 1 to 4 and Comparative Examples 1 to 5.
Further, the physical properties and running performance of the toothed belts obtained in Examples 1 to 4 and Comparative Examples 1 to 5 were measured, and the results are shown in Table 8. The tooth shearing force was measured by using the jig 13 shown in FIG. 5 and 9.8 N · c per 1 mm of the belt width in a direction perpendicular to the toothed belt.
After tightening at m, the pulling was performed in the upward arrow direction at a pulling speed of 50 mm / min, and the shearing force of the tooth portion 1 was measured. In FIG. 3, 14 is a tightening bolt, and 15 is a claw that engages with the tooth portion 1 of the toothed belt.

In the running performance test, the running time was
The test was performed at an ambient temperature of 100 ° C. using the tester shown in FIG. 6, and the life was defined as the point at which the function as a toothed belt such as the rubber crack on the back surface 3 and the crack at the base of the tooth portion 1 could not be performed. Table 8 shows the running times up to this point. In FIG. 6, reference numeral 16 denotes a drive pulley having 24 teeth (600
0 rpm), 17 is a driven pulley having 48 teeth, 18 is a driven pulley having 48 teeth, 19 is a driven pulley of 50 mmφ, 2
Reference numeral 8 denotes a 50 mmφ tension pulley.

The pronunciation test is carried out by collecting the sound produced by running the toothed belt A with the microphone 25 using the testing machine shown in FIG. The evaluation was determined. The larger the numerical value, the quieter the sound, and a value of 4.0 or more is a pass level. In FIG. 7, reference numeral 26 denotes a drive pulley having 24 teeth (3000 rpm), 2
7 is a driven pulley having 48 teeth, and 28 is a 50 mmφ tension pulley.

[0060]

[Table 8]

Next, as a running test device, the number of driving pulley teeth is 19, the number of driven pulley teeth is 38, the driving pulley rotation speed is 7200 rpm, the driven pulley load is 7.5 kW, the initial tension is 350 N, and the ambient temperature is shown in FIG. An endurance running test was performed under high load, high tension, and high temperature conditions set at 130 ° C. Tables 9 to 19 show the life time and the failure mode in the durability test together with the configuration of the belt.

[0062]

[Table 9]

[0063]

[Table 10]

[0064]

[Table 11]

[0065]

[Table 12]

[0066]

[Table 13]

[0067]

[Table 14]

[0068]

[Table 15]

[0069]

[Table 16]

[0070]

[Table 17]

[0071]

[Table 18]

[0072]

[Table 19]

Examples 5 to 16, 34 to 45 and Comparative Examples 6 to
8 and H-NBR latex using graphite or molybdenum disulfide
Treated with FL treatment liquid, and further treated with rubber 10
A tooth cloth treated with the above-mentioned RFL solution is impregnated and coated with a composition containing 50 to 400 parts by weight of PTFE with respect to 0 parts by weight, and is also integrated with tooth rubber and back rubber of the same rubber component. Has improved durability. Example 12, 1
According to 3, 41 and 42 and Comparative Example 9, the average particle diameter of the PTFE powder is preferably small, and if it exceeds 500 μm, the effect of improving the durability is reduced. According to Example 22, an effect of improving the durability is recognized in the case where the composition is applied in an amount of 7% by weight or more based on the weight of the tooth cloth before treatment. Further, according to Examples 9 to 11 and 38 to 40, a synergistic effect in improving durability is observed in the case where molybdenum disulfide, graphite, and aramid fiber powder are added to PTFE. In Examples 7, 15, and 16, 30 parts of graphite were added to 100 parts by weight of the rubber component of the RFL treatment liquid.
The effect is remarkable when it is added in an amount of 200 parts by weight. Further, in Examples 36, 44 and 45, 30 parts of molybdenum disulfide was added to 100 parts by weight of the rubber component of the RFL treatment liquid.
The effect is remarkable also when adding -200 parts by weight.

Examples 26 to 33, 55 to 62 and Comparative Example 1 in which the rubber composition impregnated and coated on the tooth cloth, the tooth rubber and the rubber composition of the back rubber were rubber components other than H-NBR.
About 0-13 and 14-16, the running test was implemented and the effect was confirmed. However, the running conditions were such that the heat resistance of the rubber composition was taken into consideration, and only the ambient temperature was 80 ° for three-axis running.
C, the temperature was changed to 60 ° C. in the multi-axis running test. The running test results are shown in Tables 13, 18, 18, and 19. Chloroprene (CR), chlorosulfonated polyethylene (CSM), styrene butadiene copolymer (SBR),
Acrylonitrile butadiene copolymer (NBR), EP
Even when the rubber composition is changed to a rubber composition such as DM, EPR, etc., the same effect as in Example 5 can be attained for improving the life.

[0075]

As described above, the present invention has a plurality of teeth arranged at predetermined intervals along the longitudinal direction, and a back portion in which a cord is embedded, and the surface of the teeth is covered with a tooth cloth. In the toothed belt, a rubber layer constituting a back portion is formed in a two-layer structure, and at least an outer layer of the two-layer structure is made of rubber having a higher hardness than an inner layer, and the front and back surfaces of the tooth cloth and The first rubber composition is impregnated and coated so that the inside is in communication with each other, and the fluororesin is dispersed in the first rubber composition without being bonded to the first rubber composition, and An adhesive component with the first rubber composition containing at least one kind of lubricating material selected from graphite or molybdenum disulfide is applied to a yarn constituting a cloth, and the first rubber composition and the teeth Part and the second rubber composition constituting the back part by vulcanization pressure Since the toothed belts embodied, the outer layer of the rear portion is formed of a rubber having a high hardness, it is possible to improve the wear resistance in the outer layer of the rear portion.

Further, according to the present invention, the outer layer of the rubber layer having the two-layer structure constituting the back portion has a modulus at 100% elongation of 4.5 MPa or more and an elongation at cut of 4 MPa.
Not less than 00% and a hardness of 3 more than that of the rubber in the inner layer.
The outer layer on the back is made of rubber with high modulus and hardness, and the inner layer on the back is lower modulus than the outer layer. Because it is made of low-hardness rubber, the outer layer on the back side can improve wear resistance and crack resistance, and the inner layer on the back side can improve quietness and life. You can do it.

Further, according to the present invention, the outer layer of the rubber layer having the two-layer structure constituting the back portion is prepared by mixing a hydrogenated nitrile rubber and an unsaturated carboxylic acid metal salt in a weight ratio of 98: 2 to 55:45. An organic peroxide is blended in an amount of 0.2 to 10 parts by weight with respect to 100 parts by weight of the polymer component to form a cross-linked rubber. A layer of rubber can be formed.

Further, in the present invention, in addition to the organic peroxide in claim 12, 5 to 50 parts by weight of carbon black and 2 to 15 parts by weight of a plasticizer are blended. High modulus and tear strength can be secured as the physical properties of rubber. Also, the present invention provides a rubber layer having a two-layer structure constituting a back portion,
100 parts by weight of a hydrogenated nitrile rubber having a hydrogenation rate of 90 to 98% is mixed with 10 to 80 parts by weight of carbon black, 2 to 15 parts by weight of a plasticizer, and 0.2 to 10 parts by weight of an organic peroxide. Since it is made of a cross-linked rubber, the rubber having the hardness and modulus necessary for quietness and life improvement can be used to form the rubber of the inner layer on the back side.

Further, according to the present invention having the above structure, the first rubber composition is impregnated and coated so that the front and back surfaces and the inside of the tooth cloth are in communication with each other, and the fluororesin is contained in the first rubber composition. At least one selected from graphite or molybdenum disulfide is dispersed in the yarn constituting the tooth cloth without being bonded to the first rubber composition.
An adhesive component with the first rubber component containing a kind of anti-friction material is provided, and the first rubber composition and the second rubber composition constituting the tooth portion and the back portion are integrated by vulcanization and pressurization. As a result, at least one kind of anti-friction material selected from graphite or molybdenum disulfide exists at a position very close to the surface, the back surface, and the inner surface of the fiber filament of the tooth cloth, and a large amount of fluorine resin is By dispersing and adhering in the composition, an effect of continuously reducing the friction coefficient during running of the belt during running and improving the tooth chipping resistance is exhibited.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view showing a structure of a main part of a toothed belt of the present invention.

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

3A and 3B are views showing the entire structure of the toothed belt of the present invention, wherein FIG. 3A is a partially cutaway perspective view, and FIG.

FIG. 4 is a partial cross-sectional view showing another example of the embodiment of the present invention.

FIG. 5 is a front view showing a belt shear force measuring jig.

FIG. 6 is a schematic view of an apparatus used for a running test.

FIG. 7 is a schematic diagram of an apparatus used for sound measurement.

FIG. 8 is a schematic view showing an apparatus for measuring durability of a toothed belt.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tooth part 2 Core wire 3 Back part 3a Outer layer 3b Inner layer 4 Tooth cloth 5 First rubber composition 6 Fluororesin 7 Weft 8 Warp 9 Second rubber composition 10 Gap 11 Boundary surface 12 Lubricant 13 1 Adhesive component 14 Tightening bolt 15 Claw 16 Driving pulley 17 Driving pulley 18 Driving pulley 19 Driving pulley 20 Tension pulley 22 Jig 25 Microphone 26 Driving pulley 27 Driving pulley 28 Tension pulley

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yasunori Nakai 4-1-1-21 Hamazoedori, Nagata-ku, Kobe City, Hyogo Prefecture Inside Mitsuboshi Belting Co., Ltd.

Claims (12)

[Claims] 1. A toothed belt having a plurality of teeth arranged at predetermined intervals along a longitudinal direction and a back having a core wire buried therein, wherein the surface of the teeth is covered with a tooth cloth. A rubber layer to be formed is formed in a two-layer structure, and at least an outer layer of the two-layer structure is made of a rubber having higher hardness than an inner layer,
The first rubber composition is impregnated and coated so that the front and back surfaces and the inside of the tooth cloth are in communication with each other, and the fluororesin is dispersed in the first rubber composition without being bonded to the first rubber composition. And a first adhesive component with the first rubber composition containing at least one type of lubricating material selected from graphite or molybdenum disulfide is further provided to the yarn constituting the tooth cloth, A toothed belt, wherein the first rubber composition and the second rubber composition constituting the teeth and the back are integrated by vulcanization and pressurization. 2. A toothed belt having a plurality of teeth arranged at predetermined intervals along a longitudinal direction and a back having a core wire buried therein, wherein a back surface of the tooth is covered with a tooth cloth. A rubber layer to be formed is formed in a two-layer structure, and at least an outer layer of the two-layer structure is made of a rubber having higher hardness than an inner layer,
A composition prepared by adding 50 to 400 parts by weight of a fluororesin to 100 parts by weight of the rubber in the first rubber composition and dispersing the resin is attached to the front and back surfaces and the inside of the tooth cloth. Giving a first adhesive component to the first rubber composition containing at least one kind of anti-friction material selected from graphite or molybdenum disulfide to the yarn to be formed, wherein the fluororesin is the first rubber composition A toothed belt, wherein the first rubber composition and the second rubber composition constituting the tooth portion and the back portion are directly bonded without being bonded to the first rubber composition. 3. A toothed belt having a plurality of teeth arranged at predetermined intervals along a longitudinal direction and a back having a core wire buried therein, wherein a back surface of the tooth is covered with a tooth cloth. A rubber layer to be formed is formed in a two-layer structure, and at least an outer layer of the two-layer structure is made of a rubber having higher hardness than an inner layer,
A composition prepared by adding and dispersing 100 to 250 parts by weight of a fluororesin to 100 parts by weight of the rubber in the first rubber composition is adhered to the front and back surfaces and the inside of the tooth cloth, further comprising the tooth cloth. Giving a first adhesive component to the first rubber composition containing at least one kind of lubricant selected from graphite or molybdenum disulfide to the yarn to be formed, wherein the fluororesin is used as the first rubber composition. A toothed belt, wherein the first rubber composition and the second rubber composition constituting the tooth portion and the back portion are directly bonded without being bonded to the first rubber composition. 4. The toothed belt according to claim 2, 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. 5. The outer layer of the two-layer structure has a modulus at the time of 100% elongation of 4.5 MPa or more, is larger than the rubber of the inner layer by at least 1.0 MPa, and has an elongation at the time of cutting of 4 MPa.
Not less than 00% and a hardness of 3 more than that of the rubber in the inner layer.
The toothed belt according to any one of claims 1 to 4, wherein the belt is formed of rubber having physical properties higher than a certain degree. 6. A polymer component in which the outer layer of the rubber layer having a two-layer structure constituting the back portion is a mixture of a hydrogenated nitrile rubber and an unsaturated metal carboxylate in a weight ratio of 98: 2 to 55:45. Organic peroxide 0.2 to 1 per 100 parts by weight
The toothed belt according to claim 5, which is formed of a crosslinked rubber containing 0 parts by weight. 7. Between the first rubber composition and the first adhesive component, or across the first rubber composition and the first adhesive component,
The toothed belt according to any one of claims 1 to 6, wherein a tooth cloth adhesive layer is provided by interposing a rubber compound containing an isocyanate compound as the second adhesive component. 8. The toothed belt according to claim 7, wherein the fluororesin is in a powder form, and the powder has an average diameter of 0.1 to 500 μm. 9. The toothed belt according to claim 1, wherein an anti-friction material other than the fluororesin is added to the first rubber composition of the tooth cloth. 10. The first rubber composition of the tooth cloth and the second rubber composition of the tooth portion and the back portion are the same type.
10. The toothed belt according to any one of items 1 to 9. 11. 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 1 to 10, which has a thickness of 0 µm. 12. A rubber layer having a two-layer structure constituting a back portion has a carbon black content of 10 to 80 parts by weight based on 100 parts by weight of a hydrogenated nitrile rubber having a hydrogenation rate of 90 to 98%.
Parts by weight, plasticizer 2 to 15 parts by weight, organic peroxide 0.2 to
The toothed belt according to any one of claims 1 to 11, wherein the toothed belt is formed of a crosslinked rubber containing 10 parts by weight.