JP2001295895A - Toothed belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toothed belt having high transmission force and an improved service life by improving abrasion resistance. SOLUTION: This toothed belt A has plural tooth parts 3 disposed along the lengthwise direction at a predetermined interval, and a back part 2 with core wires 1 embedded, and the surfaces of the tooth parts 3 are covered with tooth cloth 4. In the toothed belt A, at least a rubber layer constituting the tooth parts 3 is formed of rubber comprising a polymer constituent prepared by mixing hydrogenated nitrile rubber and an unsaturated carboxilic acid metallic salt at a mass ratio of 60:40-40:60, and a powdery anti-friction material containing at least fluororesin powder is impregnated and stuck in/to the front and rear surfaces and among fibers of 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 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. 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.

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 covered with a tooth cloth, at least a rubber layer constituting a tooth portion is composed of 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. In the toothed belt formed by. Further, a toothed belt in which a powdery anti-friction material containing at least a fluororesin powder is interposed between the front and back surfaces of the tooth cloth and the fibers and between the fibers is preferable.

Further, the rubber layer is formed of a hydrogenated nitrile rubber and an unsaturated metal salt of a carboxylic acid at 60:40 to 40: 6.
It is preferable that the rubber composition is formed of a crosslinked rubber in which 0.2 to 10 parts by mass of an organic peroxide is blended with 100 parts by mass of the polymer component mixed at a mass ratio of 0. More preferably, it is more preferable to mix 5 to 50 parts by mass of carbon black in addition to the organic peroxide.

The resin-based adhesive component and the rubber component are preferably formed by drying a resorcin-formalin-rubber latex treatment liquid. The fluororesin powder is used in an amount of 30 to 2 parts per 100 parts by mass of the rubber component.
00 parts by weight, the average particle size is 100 μm or less, and the mixture is 5 to 40% by weight of the fiber material.
% Impregnated is preferred. Further, it is preferable that the fluororesin powder is not bonded to the adhesive component and the rubber component. Further, it is preferable that the fiber material impregnated with the mixture is further adhered with a rubber paste containing a fluororesin powder and an antifriction material other than the fluororesin powder. The rubber component and the resin-based adhesive component impregnated and coated so that the front and back surfaces and the inside of the tooth cloth are in communication with each other, are entangled with each fiber constituting the fiber material, and the fluororesin powder is mixed with the fiber material and the fiber material. The fibers can be bundled on the front and back surfaces of each constituent fiber, and a large amount of fluororesin powder can be contained in the rubber component and the resin-based adhesive component. Here, the fiber material refers to a fiber material such as a nonwoven fabric, a knitted fabric, or a woven fabric formed by weaving yarns made of fibers.

In the above invention, it is preferable that a rubber compound containing an isocyanate compound is further formed as a first rubber layer on the fiber material impregnated with the mixture. Further, it is preferable that a rubber compound in which a fluororesin powder or a lubricating material other than a fluororesin powder is blended with the fibrous material on which the first rubber layer is formed is further formed as a second rubber layer. Further, it is preferable that the antifriction material is graphite.

[0018]

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 in 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. Here, in the present invention, at least the rubber constituting the teeth 3 is formed of a rubber composed of a polymer component obtained by mixing a hydrogenated nitrile rubber and an unsaturated metal carboxylate at a mass ratio of 60:40 to 40:60. It is preferred that

If the unsaturated carboxylic acid metal salt is less than 40, the rubber hardness does not reach a predetermined value, the rigidity of the teeth does not appear as intended, and the teeth are flexible, so that the belt rides on the pulley and jumps. 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 in at least the rubber constituting the teeth 3 must 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 comprising 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 elongation at break 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, the tooth cloth 4 of the toothed belt is made of rubber such that the fluororesin powder is bound between the front and back surfaces of the fiber material formed by weaving the weft 7 and the warp 8 and the fibers. A mixture 24 consisting of the component 21, the resin-based adhesive component 22, and the fluororesin powder 23 is impregnated and formed, preferably the first rubber layer 5 is further formed as a first layer, and more preferably the second rubber layer 5 is formed as a second layer. The rubber layer 6 is further formed.

The rubber component 21 is a rubber solid obtained by heating and drying a rubber latex obtained by emulsion polymerization.
The resin adhesive component 22 is an initial condensate of resorcinol and formalin. The rubber component 21 and the resin-based adhesive component 22
Means resorcinol-formalin-rubber latex (RF
L) Solid content remaining after drying and heating the treatment liquid.

The resin adhesive component 22 adheres to the fibers of the weft 7 and the warp 8. Further, a fluororesin powder 23 is dispersed and mixed in a matrix composed of the rubber component 21 and the resin-based adhesive component 22. Then, the fluororesin powder 23 is not bonded to the rubber component 21 and the resin-based adhesive component 22, and a gap is formed around or all around the fluororesin powder 23.

FIG. 3 is an enlarged photograph of a part of the tooth cloth of the toothed belt of the present invention. With reference to FIG. 3, the state in which the fluororesin powder is bundled around each fiber will be described in detail. FIG. 3 shows that the rubber component 2 containing the fluororesin powder 23
It can be seen that the mixture 24 composed of No. 1 and the resin-based adhesive component 22 adheres to the surface of each fiber. As a result, the fluororesin powder 23 can be focused on the front and back surfaces of the fiber material and between the fibers, and the friction coefficient of the tooth cloth 4 can be reduced.
Reference numeral 5 indicates a first rubber layer.

As the material of the fibrous material forming the weft 7, warp 8, etc. 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 fluororesin 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 fluororesin powder 23 is dispersed is in communication with each other on the front and back surfaces and inside of the fiber material.

The mixture 24 composed of the rubber component 21, the resin-based adhesive component 22, and the fluororesin 23 is obtained by dispersing and mixing fluororesin powder in a resorcin-formalin-rubber latex (hereinafter abbreviated as RFL) treatment liquid. It is preferable that the fiber material is formed by dipping, drying and heating.

The RFL treatment liquid is a mixture of an initial condensate of resorcinol and formalin and a rubber latex. In this case, the molar ratio of resorcinol to formalin is 3 /
It is preferable to make it 1 to 1/3 in order to increase the adhesive strength. The initial condensate of resorcinol and formalin is mixed with rubber latex so that the resin content is 5 to 50 parts by mass with respect to 100 parts by mass of the rubber component of the rubber latex. Solid concentration of 10
Adjust to ~ 40% concentration.

The rubber latex forming the rubber component 21 includes styrene-butadiene-vinylpyridine terpolymer (VP) and styrene-butadiene copolymer (SB)
R), chloroprene (CR), acrylonitrile butadiene copolymer (NBR), hydrogenated NBR (H-NB)
One or more blends of R), chlorosulfonated polyethylene (CSM), natural rubber and the like are used.

The aforementioned rubber component 21 and resin-based adhesive component 2
Fluororesin powder 23 that is not bonded to 2 is polytetrafluoroethylene, polytrifluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer,
It is at least one kind of tetrafluoroethylene-ethylene copolymer. The greater the ratio of the number of fluorine atoms in the fluororesin powder 23, the greater the effect of reducing the coefficient of friction. Therefore, assuming the same amount of adhesion to the fiber material, among the fluororesin powders 23, polytetrafluoroethylene is the most effective in reducing the coefficient of friction and has a long toothless life. But,
Other fluororesin powders also have the effect almost in proportion to the ratio of the number of fluorine atoms in the molecule.

Such a fluororesin powder 23 is made of the R
30 to 2 parts per 100 parts by mass of the rubber component in the FL treatment liquid
It is preferable to add 00 parts by mass (more preferably 50 to 200 parts by mass) to obtain a uniformly dispersed treatment liquid. Further, it is preferable that the fiber material is immersed in the treatment liquid and dried, and the solid mixture 24 containing the fluororesin powder is adjusted to have an adhesion amount of 5 to 40% based on the mass of the fiber material before immersion. . When the amount of the fluororesin powder is less than 30 parts by mass or less than 5%, the total amount of the fluororesin powder entangled in the fiber material is small, and the effect of reducing the friction coefficient is hardly recognized. 30
If the amount of the fluororesin powder exceeds 0 parts by mass or exceeds 40%, the total amount of the fluororesin powder entangled in the fiber material is too large, and the adhesion of the fiber material to the belt body or the like is reduced, and the belt performance is reduced. You.

Further, in the RFL treatment liquid, a powdery lubricating material other than the fluororesin powder may be used at the same time. Examples of the powdered antifriction material 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, cut yarn or powder of fiber. it can. In particular, graphite is well compatible with the rubber component, and further improves the durability of the belt. The amount of the powdered lubricating material is 30 to 200 parts by mass with respect to 100 parts by mass of the rubber component in the RFL treatment liquid, and it is preferable to increase the amount of the fluororesin powder added. However, there is no particular limitation on the mixing ratio of the fluororesin powder and the powdered lubricant.

The amount of the mixture adhering to the fiber material is measured by weighing the mass of the fiber material before the immersion treatment, measuring the mass (W1), and then RF-dispersing the fluororesin powder.
The fiber material is immersed in the L treatment solution, and the fiber material is placed in an oven and dried until the weight becomes constant.
2), and the equation ((W2−W1) / W1) × 100
(%).

In order to entangle a large amount of the fluororesin powder 23 into the interior of the fiber material, a fluororesin powder which has been pulverized by pulverization or granulation is used, and its average particle diameter is 100 μm.
m or less (more preferably 10 μm or less). If it exceeds 100 μm, RFL
This is because the fluororesin powder settles in the treatment liquid and becomes difficult to be uniformly dispersed, and further, the surface area of the fluororesin powder in the mixture decreases, and the effect of reducing the friction coefficient decreases. From such a viewpoint, the fluororesin powder preferably has a particle size as small as possible, for example, 10 μm or less.

Rubber glue can be adhered to the surface of the fiber material treated with the RFL solution in which the fluororesin powder is dispersed, if necessary. In the example of FIG. 2, a first rubber paste of a rubber compound containing an isocyanate compound is adhered as a first rubber layer 5, and further, a first compound of a rubber compound containing a fluororesin powder or a lubricant other than a fluororesin powder is mixed. 2 rubber paste is adhered as the second rubber layer 6. The first rubber layer 5 can be omitted, and the second rubber layer 6 can be formed on the surface of a fiber material treated with an RFL treatment liquid containing a fluororesin powder. Alternatively, a second rubber layer 6 of a rubber compound containing an isocyanate compound and a fluororesin powder or a lubricating material other than the fluororesin powder as the second rubber paste is formed of a fibrous material treated with an RFL treatment liquid containing a fluororesin powder. It can also be formed on the surface.

The first rubber layer 5 functions as an intermediate layer for increasing the adhesive strength, and the isocyanate compound acts as an adhesive component. Therefore, the first rubber paste having the same type of rubber component as the belt main body can be employed. This first rubber paste is obtained by mixing a rubber compound of the same type as the belt body with methyl ethyl ketone (ME
K), formed by dissolving in a solvent such as toluene, adding an isocyanate compound to form a treatment liquid, applying the treatment liquid, and then drying and solidifying. Examples of the isocyanate compound used in the treatment liquid include 4,4 ′
-Diphenylmethane diisocyanate, tolylene 2,4
-Diisocyanate, polymethylene polyphenyl diisocyanate, hexamethylene diisocyanate, polyaryl polyisocyanate (for example, PAP as trade name)
I). This isocyanate compound is also used by being mixed with an organic solvent such as toluene and methyl ethyl ketone. Further, a polyisocyanate in which an isocyanate group of the polyisocyanate is blocked by reacting a blocking agent such as a phenol, a tertiary alcohol, and a secondary alcohol with the above isocyanate compound can also be used.

The second rubber layer 6 functions as a surface layer having a friction coefficient reducing effect, and contains a fluorine resin powder or an antifriction material other than the fluorine resin powder. This second rubber layer 6
In the same manner as in the first rubber layer 5, 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. It is formed by applying a treatment liquid, drying and solidifying the liquid. 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 material of the rubber compound forming the back portion 2 may be the same rubber as that of the tooth portion 3 or an appropriate material may be appropriately selected according to the conditions of use. H-NBR, CR, CS for toothed belts used for general industrial machines
M, NBR, ethylene propylene diene monomer (EPDM), ethylene propylene copolymer (EP
R), SBR, isoprene rubber (IR), natural rubber (N
R), fluorine rubber, silicon rubber and the like can be used. In the case of such a toothed belt, the use of the tooth cloth described with reference to FIG. 2 is effective.

There is no limitation on the core wire 1 buried inside the belt body, and a glass core wire and an aramid core wire are generally used. In addition, polybenzoxazole, polyparaphenylene naphthalate, polyester, acrylic,
Any of twisted cords composed of 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.

In the belt having the above-described structure, a rubber component, a resin-based adhesive component, and a fluororesin powder that is not bonded thereto are applied to the fiber material coated on the tooth surface of the belt on the front and back surfaces of the fiber material and the internal fibers. By locating in a close position, a large amount of fluororesin powder can be dispersed in the fiber material. In addition, the resin-based adhesive component in the fiber material has an effect of improving the adhesiveness of the belt body and the like, and ensuring the retention of the fluororesin powder that is not bonded to the rubber component and the resin-based adhesive component. Therefore, the rubber component to be impregnated and attached to the fiber material does not need to be the same type as the belt main body, and can be appropriately selected according to the use conditions.

[0045]

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.

[0047]

[Table 1]

[0048]

[Table 2]

(Tooth cloth 4) A coating fiber material having the composition and composition shown in Table 3 was prepared. Further, the RFL treatment solutions shown in Table 4 were prepared. Further, a solution of the rubber paste shown in Table 5 was prepared.

[0050]

[Table 3]

[0051]

[Table 4]

[0052]

[Table 5]

Example A The fiber materials shown in Table 3 were immersed in an RFL treatment solution containing a fluororesin powder, dried at 120 ° C., and then heat-treated at 180 ° C. for 2 minutes. Next, the rubber compounds in Tables 1 and 2
K, polyaryl polyisocyanate (trade name: PAPI) as an isocyanate compound after being dissolved in toluene
The fiber material after the RFL treatment was immersed in the treatment liquid to which was added, to form a first rubber layer. Further, according to the treatment liquid composition table of Table 5, the rubber composition of Tables 1 and 2 was added to the rubber compound 10
20 parts by weight of Nocrack NBC (anti-aging agent) to 0, MEK and toluene were added to give a treatment liquid such that the rubber compound and Nocrack NBC became about 15% based on the mixed liquid. A treatment liquid was prepared by adding and mixing graphite. The fiber material having the first rubber layer formed thereon was immersed in the treatment liquid and dried to form a second rubber layer, thereby obtaining a tooth cloth for covering the belt body.

Next, the above-mentioned tooth cloth was wound around a mold for producing a belt, and a pair of SZ-twisted pairs of RFL 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 ordinary press-fitting (press vulcanization at 160 ° C. for 30 minutes to form) to obtain a cylindrical vulcanized molded product.

[0055]

[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 8 shows combinations of the materials of Examples 1 to 3 and Comparative Examples 1 to 4. 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 8. The tooth shear force was measured using the jig 13 shown in FIG.
50mm / after tightening at 9.8N · cm per mm
This was performed by pulling in the direction of the arrow at a pulling speed of min and measuring the shearing force of the tooth portion 1. In FIG. 4, reference numeral 14 denotes a fastening bolt, and reference numeral 15 denotes a claw that engages with the tooth portion 1 of the toothed belt A.

As shown in FIG. 5, the adhesive force of the tooth cloth is measured by holding the belt body A with one jig 13 and using the other jig to remove the tooth cloth 4 which has been peeled off from the belt body A in advance. After gripping, the tooth cloth 4 is pulled upward in the direction of the arrow at a tension speed of 50 mm / min, and the average value of the force with which the tooth cloth 4 is continuously peeled off from 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.

[0059]

[Table 7]

From Table 7, it is found 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.

[0061]

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, at least the rubber layer constituting the tooth portion is made of a hydrogenated nitrile rubber and an unsaturated carboxylic acid metal salt in a ratio of 60:40 to
The rubber formed of a polymer component mixed at a mass ratio of 40:60 has the effects of accurately forming the teeth and increasing the jumping torque, thereby improving the transmission power of the belt.

Further, the present invention provides a resin-based adhesive component, a rubber component, and the fluororesin powder so that a powdered lubricating material containing at least a fluororesin powder is bound between the front and back surfaces and the fibers of the tooth cloth. Since the powdered anti-friction material is impregnated and adhered to the front and back surfaces of the fiber material and between the fibers, there is an effect that the wear of the tooth cloth does not progress and the durability of the toothed belt is improved.

Further, in the present invention, the rubber layer comprises a hydrogenated nitrile rubber and a metal salt of unsaturated carboxylic acid at 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 mixed with 5 to 50 parts by mass of carbon black, the teeth are formed accurately, the jumping torque is stabilized at a high value, and the transmission power of the belt is stably improved. .

According to the present invention having the above structure, a rubber compound containing an isocyanate compound is further formed as a first rubber layer on the fiber material impregnated with the mixture, and the first rubber layer is further impregnated with the rubber compound. Since the formed rubber material was further formed with a second rubber layer containing a fluororesin powder or a lubricating material other than the fluororesin powder, a rubber component and a resin containing a large amount of fluororesin powder to the interior of the fiber material In addition to being able to position the system adhesive component, the presence of the lubricating material outside the fiber material also allows the lubricating material to be present multiple times in a continuous fashion, maintaining the friction coefficient during belt running during running. This has the effect of reducing it.

[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 First rubber layer 6 Second rubber layer 7 Weft 8 Warp 9 Rubber compound 11, 12 Boundary surface 13 Jig 14 Tightening bolt 15 Nail 21 Rubber component 22 Resin adhesive component 23 Fluororesin 24 mixture

Claims (10)

[Claims] 1. A toothed belt having a plurality of teeth arranged at predetermined intervals along a longitudinal direction and a back part having a core wire buried therein, wherein the surface of the teeth is covered with a tooth cloth. Wherein the rubber layer comprises a rubber composed of a polymer component 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. 2. A resin-based adhesive component, a rubber component, and a powdery material containing the fluororesin powder so that a powdery lubricating material containing at least a fluororesin powder is bound between the front and back surfaces and the fibers of the tooth cloth. 2. The toothed belt according to claim 1, wherein an antifriction material is impregnated and attached between the front and back surfaces of the fiber material and the fibers. 3. The organic rubber composition according to claim 1, wherein said rubber layer comprises 100 parts by mass of a polymer component obtained by mixing a hydrogenated nitrile rubber and an unsaturated carboxylic acid metal salt in a mass ratio of 60:40 to 40:60. The toothed belt according to claim 1, wherein the toothed belt is formed of a rubber crosslinked by mixing 2 to 10 parts by mass. 4. The toothed belt according to claim 3, further comprising 5 to 50 parts by mass of carbon black in addition to the organic peroxide. 5. The toothed belt according to claim 2, wherein the resin-based adhesive component and the rubber component are formed by drying a resorcin-formalin-rubber latex treatment liquid. 6. The fluororesin powder according to claim 1, wherein
3 to 200 parts by mass, the average particle size is 100 μm or less, and the mixture is impregnated with 5 to 40% of the mass of the fiber material.
6. The toothed belt according to any one of items 1 to 5. 7. The toothed belt according to claim 2, wherein the fluororesin powder is not bonded to the adhesive component and the rubber component. 8. The toothed belt according to claim 2, wherein a rubber compound further containing an isocyanate compound is formed as a first rubber layer on the fiber material impregnated with the mixture. 9. The tooth according to claim 8, wherein a second rubber layer further comprising a fluororesin powder or a lubricating material other than a fluororesin powder is formed on the fiber material impregnated with the first rubber layer. With belt. 10. The toothed belt according to claim 9, wherein the antifriction material is graphite.