JP3128460B2 - Toothed belt - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toothed belt for transmitting torque of each shaft between a crankshaft, a camshaft, a balancer shaft and the like of an engine in an internal combustion engine, for example.

[0002]

2. Description of the Related Art A conventional toothed belt has, for example, a structure in which a tooth portion is formed on one surface of a belt body and a core wire is embedded in the belt body. In recent years, as the performance of an internal combustion engine has improved, the rotational speed of a crankshaft has increased, and a large load has been generated to drive various accessories. For this reason, the temperature around the installation of the toothed belt is becoming higher.

[0003] As a raw material rubber used for the belt body, hydrogenated nitrile rubber has recently been used as a high-performance heat-resistant belt for internal combustion engines instead of chloroprene rubber.

[0004] Hydrogenated nitrile rubber has heat resistance due to hydrogenation. On the other hand, in the case of vulcanization with sulfur and a sulfur-based vulcanization accelerator, the vulcanized rubber is increased as the rate of hydrogenation is increased. Cross-linking point decreases. Therefore, even if it shows excellent heat resistance under a static environment, the rubber itself generates heat under a dynamic environment, for example, where the rubber repeatedly expands and contracts at a high speed (hereinafter, referred to as “
Internal heat generation), and the rebound resilience (hereinafter referred to as a permanent set) for restoring rubber deformation under a load is adversely affected. That is, the heat resistance of the toothed belt does not elongate as expected even when the raw material rubber with an increased amount of hydrogen added is used, and it has become difficult to meet the above-mentioned requirements of the internal combustion engine.

In order to solve such a problem, for example, Japanese Patent Application Laid-Open No. 63-270753 discloses a method in which a hydrogenated nitrile rubber is mixed with a metal salt of an ethylenically unsaturated carboxylic acid such as zinc methacrylate having a different vulcanization method. A rubber crosslinked with a peroxide such as dicumyl peroxide is disclosed. However, although this rubber is slightly improved in terms of increasing heat resistance and rigidity with elasticity, it cannot be said that it is still sufficient in suppressing internal heat generation.

On the other hand, when peroxide vulcanization is performed, the surface of the canvas deteriorates due to radicals generated from the peroxide vulcanizing agent, and the durability of the canvas covering the belt teeth deteriorates. In some cases, adhesion to rubber may be hindered, and thus a problem arises in that the running life is shortened.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the internal heat generation of the belt body can be suppressed to a low level even during high-speed running under a high load. Even without this, it is possible to keep the adhesion between the rubber and the core wire and between the rubber and the canvas high, and by maintaining the performance of the canvas covering the teeth, the teeth are not easily chipped and the running life is long. The purpose is to obtain a toothed belt.

[0008]

A toothed belt according to the present invention has a tooth portion formed on at least one surface, the surface of the tooth portion is covered with canvas, and the core wire extends along the longitudinal direction. has a belt body embedded Te, 0.8 the belt body, the hydrogenation ratio is 91% or more hydrogenated nitrile rubber and raw rubber, relative to the raw material rubber 100 parts
A sulfur-based vulcanizing agent parts, 0.3-2 parts of the Periodic Table VIa
Dialkyldithiocarbamic acid metal salt formed with a group III metal and 0.5 to 5 parts of thiuram and N-cyclo
It is characterized by being formed of a rubber to which a vulcanization accelerator containing hexyl-2-benzothiazyl sulfenamide and a vulcanization acceleration aid are added.

The hydrogenated nitrile rubber has a hydrogenation rate of 80.
%, The hydrogenation rate exceeds 91%, but when the hydrogenation rate exceeds 91%, vulcanization is not completely performed on the remaining double bonds, and the rubber has a sufficient heat resistance under a dynamic environment. Does not stretch. Therefore, in the power transmission belt of the present invention, the belt body is made of a hydrogenated nitrile rubber having a hydrogenation ratio of 91% or more as a raw material, and a sulfur-based vulcanizing agent and a periodic rate of 1 to 3 parts with respect to 100 parts of the raw rubber. It is formed of a vulcanization acceleration aid containing a dialkyldithiocarbamic acid as a metal salt of Table VIa group, and a rubber to which a vulcanization acceleration aid is further added. A core wire is embedded in the belt main body along the longitudinal direction of the belt.

[0010] In the present specification, the hydrogenation rate relative to the raw rubber is indicated by a value measured by an iodine value method. Further, in the present specification, the high molecular weight type hydrogen nitrile rubber refers to a raw material rubber having a Mooney viscosity of 91 or more at 100 ° C., and is usually a raw material rubber at the same temperature as the molecular weight type hydrogen nitrile rubber. Has a Mooney viscosity of less than 91.

The hydrogenation rate of the raw rubber is preferably 91.5 to 93.5%.

The sulfur vulcanizing agent is at least one of powdered sulfur and insoluble sulfur.

The alkyl group of the metal dialkyldithiocarbamate contained in the vulcanization accelerator may be either a methyl group or an ethyl group. The metal of the metal dialkyldithiocarbamate is Group VIa which is the same as sulfur used in the vulcanizing agent in the periodic table. The Group VIa metal may be selenium or tellurium.

The vulcanization accelerator is, for example, zinc white.

[0015] The core wire is made of high strength glass fiber.

The canvas covering the surface of the belt body is, for example, a woven fabric having nylon yarn and / or aramid yarn.

Hereinafter, the toothed belt of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view in which a part of a toothed belt 11 according to an embodiment of the present invention is partially cut away. A tooth portion 14 is formed on one surface of the belt body 12, and a core wire 13 having an S twist and a core wire 13 having a Z twist are arranged in parallel on a pitch line of the belt body 12. (However, the S-twisted and Z-twisted cores 13 are not distinguished in FIG. 1). The surfaces of the teeth 14 are covered with a canvas 16 made of aramid fiber and / or nylon fiber.

In the embodiment, an ethylenically unsaturated nitrile-conjugated diene-based highly saturated copolymer rubber (hydrogenated nitrile rubber) is used as a raw material rubber constituting the belt body 12. Ethylenically unsaturated nitrile is defined as having a nitrile group (-C at one end of adjacent carbon having an ethylenically unsaturated bond.
N) is a compound to which acrylonitrile and the like are added. A conjugated diene is a compound in which two double bonds are adjacent to each other, such as butadiene and isoprene.

In an embodiment, the raw material hydrogenated nitrile rubber has a sulfur-based vulcanizing agent and at least one of tetramethylthiuram disulfide, dipentamethylenethiuram tetrasulfide and N-cyclohexyl-2-benzothiazyl sulfenamide. And a vulcanization accelerator containing tellurium diethyl dithiocarbamate, and zinc vulcanization as a vulcanization acceleration aid, carbon black, trimellitate isonolyl, stearic acid, N-isopropyl-N'-phenyl-p -A rubber to which phenylenediamine is added is used. The vulcanization accelerator preferably contains all of tellurium diethyl dithiocarbamate, tetramethylthiuram disulfide, dipentamethylenethiuram tetrasulfide and N-cyclohexyl-2-benzothiazyl sulfenamide.

A high-strength glass fiber is used for the core wire 13.

The canvas 16 is twill-woven with an aramid yarn 17 provided along the belt longitudinal direction and a nylon yarn 18 provided along the belt width direction. However, the configuration of these yarns and the weave of the canvas 16 need not be limited to these. For example, the yarn in the belt longitudinal direction may be a nylon yarn having excellent rigidity and heat resistance, or a crimped yarn made of a nylon yarn. The aramid yarn may have a covering specification. The canvas 16 may be satin weave, plain weave, or various modified weaves depending on the purpose.

The canvas 16 formed as described above is used.
Is treated with a resorcinol / formaldehyde / latex aqueous solution containing carboxylic nitrile rubber as a latex component, and adheres to the belt body 12. If necessary, it may be treated with rubber glue.

[0024]

【Example】

[Example rubber, comparative example rubber and conventional rubber] Table 1 shows the composition of the example rubber, and Table 2 shows the composition of the comparative example rubber and the conventional rubber.

[0025]

[Table 1]

In Table 1, the unit of * 1 is%, the unit of * 2 is an anonymous number, the unit of * 3 is parts by weight, * 4 is the abbreviation for N-isopropyl-N'-phenyl-p-phenylesodiamine,
* 5: Tetramethylthiuram disulfide, dipentamethylenethiuram tetrasulfide and N-cyclohexyl-2-benzothiazyl sulfenamide, * 6: Tellurium diethyldithiocarbamate, * 7: JI
Measured value at room temperature by SA hardness tester, * 8: Measured value by JIS-A hardness tester at room temperature after 280 hours in 140 ° C thermal environment, * 9: Room temperature rubber physical hardness The value of the difference from the heat-resistant rubber physical hardness (anonymous number), * 10 is based on the Goodrich Flexo Test (ASTM D 623-62).
As a result of measurement under a temperature condition of 100 ° C. (unit is degrees Celsius), the measurement method of * 11 is the same as that of * 10 (unit is%). *** indicates not blended, and ---- indicates that there is no description.

[0027]

[Table 2]

In Table 2, the unit of * 1 is%, the unit of * 2 is an anonymous number, the unit of * 3 is part by weight, * 4 is an abbreviation of N-isopropyl-N'-phenyl-p-phenylene diamine,
* 5: Tetramethylthiuram disulfide, dipentamethylenethiuram tetrasulfide and N-cyclohexyl-2-benzothiazyl sulfenamide, * 6: Tellurium diethyldithiocarbamate, * 7: JI
Measured value at room temperature by SA hardness meter, * 8: Measured by JIS-A hardness meter at room temperature after 280 hours in a 140 ° C thermal environment, * 9: Room temperature rubber physical property hardness The value of the difference from the heat-resistant rubber physical hardness (anonymous number), * 10 is based on the Goodrich Flexo Test (ASTM D 623-62).
The result of measurement under the temperature condition of 100 ° C. (unit is degree Celsius), the measurement method of * 11 is the same as * 10 (unit is%). *** indicates not blended, and ---- indicates that there is no description.

Example Rubber 1 had a hydrogenation rate of 93.5%.
100 parts of the starting hydrogenated nitrile rubber, 60 parts of carbon black and 10 parts of trimellitate isonolyl
Parts, 1.0 part of stearic acid, N-isopropyl-N-
1.0 part of phenyl-p-phenylenediamine, 0.8 part of sulfur, 2.7 parts of tetramethylthiuram disulfide, dipentamethylenethiuram tetrasulfide and 2.7 parts of N-cyclohexyl-2-benzothiazyl sulfenamide, Tellurium diethyl dithiocarbamate
It is a compounded rubber with 0 parts added.

Example Rubber 2 is a hydrogenated nitrile rubber 1 having a hydrogenation rate of 92.3%, which is lower than that of Example Rubber 1.
To 00 parts, 60 parts of carbon black, 10 parts of trimellitate-isononyl, 1.0 part of stearic acid, 1.0 part of N-isopropyl-N-phenyl-p-phenylenediamine, 0.8 parts of sulfur, Tetramethylthiuram
It is a compounded rubber obtained by adding 2.7 parts of disulfide, dipentamethylenethiuram tetrasulfide, N-cyclohexyl-2-benzothiazyl sulfenamide, and 1.0 part of tellurium diethyldithiocarbamate.

Example Rubber 3 is a hydrogenated nitrile rubber 1 having a hydrogenation rate of 91.5%, which is lower than that of Example Rubber 2.
To 00 parts, 60 parts of carbon black, 10 parts of trimellitate-isononyl, 1.0 part of stearic acid, 1.0 part of N-isopropyl-N-phenyl-p-phenylenediamine, 0.8 parts of sulfur, Tetramethylthiuram
It is a compounded rubber obtained by adding 2.7 parts of disulfide, dipentamethylenethiuram tetrasulfide, N-cyclohexyl-2-benzothiazyl sulfenamide, and 1.0 part of tellurium diethyldithiocarbamate.

Example rubber 4 was prepared by adding 60 parts of carbon black to 100 parts of a hydrogenated nitrile rubber having a hydrogenation ratio of 92.5% between those of Example rubber 1 and Example rubber 2.
Parts, 10 parts of trimellitate isonolyl, 1.0 part of stearic acid, 1.0 part of N-isopropyl-N-phenyl-p-phenylenediamine, 0.8 part of sulfur, tetramethylthiuram disulfide, dipentane Methylenethiuram tetrasulfide and N-cyclohexyl-2-
It is a compounded rubber containing 2.7 parts of benzothiazyl sulfenamide and 1.0 part of tellurium diethyldithiocarbamate.

The rubber used for the comparative rubber was 100 parts of a hydrogenated nitrile rubber having a hydrogenation rate of 93.5% which is the same as that of the rubber of Example 1, 60 parts of carbon black, 10 parts of trimellitate toisonolyl, and stearin. 1.0 part acid,
1.0 part of N-isopropyl-N-phenyl-p-phenylenediamine, 0.5 part of sulfur, tetramethylthiuram disulfide, dipentamethylenethiuram tetrasulfide and N-cyclohexyl-2-benzothiazyl sulfenamide Is a compounded rubber consisting of 2.7 parts. The difference is that the amount of sulfur is reduced and that tellurium diethyldithiocarbamate is not added as compared with the rubbers of Examples 1 to 4.

The rubber used in the conventional rubber has a hydrogenation rate of 9
It is a hydrogenated nitrile rubber having a hydrogenation rate of 0.5%, which is lower than that of the rubbers of Examples 1-4. The compounding is 100 parts of hydrogenated nitrile rubber, 60 parts of carbon black,
10 parts of trimellitate isonolyl, 1.0 part of stearic acid, 1.0 part of N-isopropyl-N-phenyl-p-phenylenediamine, 0.5 part of sulfur, tetramethylthiuram disulfide, dipentamethylenethiuram A compounded rubber composed of 2.7 parts of tetrasulfide and N-cyclohexyl-2-benzothiazyl sulfenamide. As in the comparative rubber, tellurium diethyl dithiocarbamate was not added.

The sulfur of the vulcanizing agent may be powdered sulfur or insoluble sulfur.

[Method for Measuring and Evaluating Rubber Hardness Under Thermal Environment] A dumbbell-type rubber sample whose hardness was measured at room temperature was
It was placed in a thermostat in which hot air at 140 ° C. circulated, and was allowed to elapse for 280 hours under a thermal environment. After returning to room temperature, the hardness was measured again. A rubber sample having a small difference in hardness before and after being put in a thermostat has excellent heat resistance, but a rubber sample having a large difference in hardness has not excellent heat resistance. Table 1 and Table 2 show the results.
Of "normal rubber physical properties / rubber hardness", "heat-resistant rubber physical properties / rubber hardness", and "heat-resistant rubber physical properties / hardness increase".

[Method of Measuring and Evaluating Internal Heat Generation] The internal heat generation is measured by a Goodrich Flexo Test (ASTM D6).
23-62 Standard Methods of Test for COMPRESSIO
N FATIGUE OF VULCANIZED RUBBER). As a rubber test piece, 0.77 inch (1
(9.6 mm) was used. Celsius 10
0 degrees, the frequency of pressing is 1800 times / minute, and the pressing distance is 0.
121 inches (3.07 mm) with a load of 23 pounds (10
2 Newton), the temperature rise of the test piece was measured using a thermocouple. A small measured value means that the internal heat generation of the rubber sample is small, and a large measured value means that the internal heat generation of the rubber sample is large. The results are shown in Table 1 and Table 2 in the column of “Dynamic physical properties / internal heat generation”.

[Measurement Method and Evaluation Method of Permanent Set] As for the permanent set, the rate of deformation accompanying the Goodrich Flexo test was measured and expressed as a percentage. A small value means that the percentage of deformation remaining after the load is removed is small, and a large value means that the percentage of deformation is large. The results are shown in Tables 1 and 2
Permanent set ".

[Example: increase in hardness of rubber] As shown in Table 3, the degree of increase in hardness (measured by a JIS-A hardness tester, the same applies hereinafter) after a heat resistance test at 140 ° C for 280 hours is determined by the hydrogenation rate. Is 91.5% in Example Rubber 3, plus 13,
Example rubber 2 having a hydrogenation rate of 92.5% was plus 12, and Example rubber 4 having a hydrogenation rate of 92.5% was plus 12 and example rubber 1 having a hydrogenation rate of 93.5%. Then, it is an increase of +11. The degree of increase in hardness of the conventional rubber having a hydrogenation rate of 90.5% shown in Table 2 is plus one.
7, which indicates that the heat resistance under a static environment is excellent.

[Internal Heat Generation of Example Rubber] As shown in Table 1, under a dynamic environment, the internal heat generation of the sample of Example Rubber 3 having a hydrogenation rate of 91.5% was 10.5 °. C,
The sample of Example Rubber 2 having a hydrogenation rate of 92.3% was plus 9.5 ° C., and the Example Rubber 4 having a hydrogenation rate of 92.3% was added.
In the sample of 9.5 ° C, the hydrogenation rate was 93.5%.
The sample of Example Rubber 1 shows a value of plus 9.5 ° C. This is smaller than the internal heat generation value of the conventional rubber sample shown in Table 2 of 11 ° C., which indicates that the rubbers of the examples have excellent heat resistance under a dynamic environment.

[Example: Permanent set of rubber] A permanent set under such a dynamic environment is as follows.
The value of Example Rubber 3 having a hydrogenation rate of 91.5% was 0.6.
%, And the value of Example Rubber 2 having a hydrogenation rate of 92.3% was 0.1%.
The value of Example Rubber 4 having 7% and a hydrogenation rate of 92.3% is 0.7%, and the value of Example Rubber 1 is 0.8%. This value is smaller than the value of 0.9% of the conventional permanent set, and has better heat resistance than conventional rubber in a dynamic environment.
It shows that the performance of restoring the original shape is excellent.

[Comparison of Example Rubber, Comparative Example Rubber, and Conventional Rubber] As shown in Table 2, the heat resistance test was 140 ° C. × 28.
The degree of increase in hardness after 0 hour is 13 in the comparative example rubber having a hydrogenation rate of 93.5%, and the degree of hydrogenation is 9%.
It is smaller than the plus 17 of the conventional rubber of 0.5%, which indicates that the heat resistance of the comparative rubber is improved in the static environment of the rubber. However, the heat resistance of the rubber of Comparative Example is lower than that of each of the rubbers of Examples.

As shown in Table 2, the values of both the internal heat generation and the permanent set are larger in the comparative rubber than in the conventional rubber. This indicates that, in the dynamic environment of the comparative rubber and the conventional rubber, merely increasing the hydrogenation rate does not increase the number of crosslinking points, and the restoring force against an external load is poor.

[Comparison with high-molecular-weight type] As shown in Table 3, the high-molecular-weight type hydrogenated nitrile rubber also had a hydrogenation amount of 92.5% and the same vulcanization system as the rubber of Example. In the case of using, under a dynamic environment, both internal heat generation and permanent set were excellent. However,
The adhesive strength per 25 mm between the hydrogenated nitrile rubber and the core wire was 196 Newton in the case of the rubber of the conventional molecular weight, but was only 127 Newton in the case of the rubber of the high molecular weight type.

[0045]

[Table 3]

In Table 4, the unit of * 1 is%, the unit of * 2 is an anonymous number, the unit of * 3 is part by weight, and * 4 is N-isopropyl-N'-phenyl-p-phenylene diamine.
* 5 is tetramethylthiuram disulfide, dipentamethylenethiuram tetrasulfide and N-cyclohexyl-2-benzothiazyl sulfenamide, * 6 is abbreviation of tellurium diethyldithiocarbamate, * 10 is Goodrich Flexo Test (ASTM) D 623-6
Based on 2), the result of measurement under a temperature condition of 100 ° C. (unit is degree Celsius), the measurement method of * 11 is the same as * 10 (unit is%).

[Example Belt, Comparative Example Belt, and Conventional Belt] In order to confirm the performance of the belt, Example Rubber 1, Example Rubber 4, Comparative Example Rubber, and Conventional Rubber shown in Tables 1 and 2 were selected. Then, a toothed belt was prepared using these rubbers. These are referred to as an example belt 1, an example belt 2, a comparative example belt, and a conventional belt, respectively.

[0048]

[Table 4]

In Table 4, the unit of * 1 is%, the unit of * 2 is an anonymous number, and * 14 is a belt that extends over two axes.
JIS- before and after running for 1000 hours at a rotation speed of 6000 rpm for 1 minute under a temperature environment of 0 ° C.
Difference of measured value at room temperature by hardness meter of A, * 15 is * 14
These are the results when the same test as that described above was performed in a temperature environment of 140 ° C.

[Test Method and Evaluation Method for Running Belt Hardness in Thermal Environment] A running test in a thermal environment was performed to evaluate the performance of the example belt, the comparative example belt and the conventional belt at an early stage. Since the deterioration of the rubber constituting the belt is represented by an increase in the hardness of the rubber, the thermal environment is set to 120 ° C., the number of revolutions is set to 6,000 revolutions per minute, and the running is performed for 1000 hours. Was measured, and the hardness change was evaluated. When the difference in hardness is small, it can be evaluated as having excellent heat resistance, and when the difference in hardness is large, it cannot be evaluated as having excellent heat resistance. The rubber hardness was measured on the back of the running belt. The results are shown in the column of “Belt Back Hardness Increase” in Table 4.

[Test Method and Evaluation Method of Belt Life in Thermal Environment] The belt was run at a rotation speed of 6000 rpm for 1 minute in a temperature environment of 140 ° C. surrounded by a heat insulating material. The belt life was measured by measuring the running time from the start of running to the occurrence of missing teeth, and the number of hours was evaluated. The results are shown in the column of "Time until missing of teeth" in Table 4.

[Increasing rubber hardness of conventional belt] A core made of high-strength glass fiber is embedded in a belt body made of a conventional hydrogenated nitrile rubber having a hydrogenation rate of 90.5%, and sulfur vulcanization is performed. When the conventional belt in which the formed tooth portion is covered with canvas made of nylon 6, 6 was run for 1000 hours under a heat environment of 120 ° C., the hardness of the rubber constituting the belt increased by +15. .

[Increasing Rubber Hardness of Comparative Example Belt] On the other hand, a core made of high-strength glass was embedded in a belt body made of a comparative rubber whose hydrogenation rate was increased to 93.5%.
The comparative belt, in which the teeth formed by sulfur vulcanization were covered with a canvas made of nylon 6,6, was run for 1000 hours in a 120 ° C. heat environment. It was smaller than the increase in rubber hardness of the belt.

[Increasing Rubber Hardness of Example Belt 1] Using Example Rubber 1 which is a hydrogenated nitrile rubber having a hydrogenation rate of 93.5%, a core made of high-strength glass is embedded, and made of nylon. In the example belt 1 in which the tooth portion was covered with the canvas, the hardness of the rubber after running for 1000 hours under a heat environment of 120 ° C. was plus 12, which was smaller than that of the comparative example belt. However, there was not much difference.

[Increasing Rubber Hardness of Example Belt 2] A core wire made of high-strength glass was buried in a belt body made of Example Rubber 4 having a hydrogenation rate of 92.5%, and formed by sulfur vulcanization. In Example Belt 2 in which the tooth portion was covered with a canvas made of aramid fiber and nylon fiber, the hardness of the rubber after running for 1000 hours under a heat environment of 120 ° C. was plus 10, which was a difference between the conventional belt and the conventional belt. It was found that the increase in hardness was lower than that of the example belt.

[Belt Life of Conventional Belt and Comparative Example Belt] A conventional belt using a hydrogenated nitrile rubber having a hydrogenation rate of 90.5% was run at a temperature of 140 ° C. It led to chipping. The comparative example belt made of a conventional rubber having a hydrogenation rate of 93.5%, which is higher than that of the conventional belt, and combined with a nylon canvas, suffered tooth loss after 700 hours of running under the same thermal environment. When running underneath, the life extension is small.

[Belt Life of Example Belt 1] A hydrogenated nitrile rubber having a hydrogenation rate of 93.5%, which is the same as that of the comparative example belt, was used. As a vulcanization accelerator, tellurium diethyl dithiocarbamate, tetramethylthiuram disulfide,
Dipentamethylenethiuram tetrasulfide and N
-Example belt using cyclohexyl-2-benzothiazylsulfenamide-Example belt 1 using rubber 1
Had tooth loss after running for 900 hours in a temperature environment of 140 ° C. Compared with the conventional belt, the heat-resistant life is considerably extended.

Example 1 Belt Life of Belt 1 A hydrogenated nitrile rubber having a hydrogenation rate of 92.5% was used. Diethyldithiocarbamate tellurium was used as a vulcanization accelerator.
Example using tetramethylthiuram disulfide, dipentamethylenethiuram tetrasulfide and N-cyclohexyl-2-benzothiazylsulfenamide Example using rubber 2 and canvas made of aramid fiber and nylon fiber After running for 1200 hours, the belt 2 had tooth loss. Along with the effect of covering the teeth with a canvas made of aramid fiber having excellent heat resistance, the belt has a longer heat-resistant life.

The toothed belt of the present invention can be applied to a double toothed belt having belt teeth on both sides.

[0060]

As described above, according to the present invention, even in sulfur vulcanization, since the internal heat generation of the rubber is small, the deterioration of the rubber itself and the deterioration of the adhesion in a belt used in a thermal environment are suppressed. You. Further, since the permanent set is good, chipping of the belt teeth is suppressed. Furthermore, since the deterioration of the canvas and the inhibition of adhesion between the cord and the rubber due to peroxide vulcanization do not occur, the performance of the canvas covering the belt teeth is maintained. Further, since a high molecular weight type of the hydrogenated nitrile rubber is not used, the rubber and the canvas, the rubber and the core wire are securely bonded, and a long life belt can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a toothed belt according to one embodiment of the present invention.

[Explanation of symbols]

 11 Toothed belt 12 Belt body 13 Core wire

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-143681 (JP, A) JP-A-8-118507 (JP, A) JP-A-6-26553 (JP, A) JP-A-5-265 222242 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B29D 29/00-29/08 F16G 1/28

Claims (12)

(57) [Claims] Claims: 1. A tooth is formed on at least one surface,
The surface of the tooth portion is covered with a canvas, and has a belt body in which a core wire is embedded along a longitudinal direction, and the belt body is made of a hydrogenated nitrile rubber having a hydrogenation rate of 91% or more. Rubber, 0.8 part of sulfur-based vulcanizing agent and 100 parts of this raw rubber, and 0.3 to 2 parts of cycle
Dialkyl dithiocarbamic acid metal salt to form a salt in Table VIa group metals and 0.5 to 5 parts thiuram and
N-cyclohexyl-2-benzothiazyl sulfene
A toothed belt formed of a rubber to which a vulcanization accelerator containing an amide and a vulcanization accelerator are added. 2. The hydrogenation rate is 91.5 to 93.5%.
The toothed belt according to claim 1, wherein: 3. The toothed belt according to claim 1, wherein the sulfur- based vulcanizing agent is at least one of powdered sulfur and insoluble sulfur. 4. The toothed belt according to claim 1, wherein the alkyl group of the metal dialkyldithiocarbamate is any one of a methyl group and an ethyl group. 5. The toothed belt according to claim 1, wherein the metal of the metal salt of dialkyldithiocarbamic acid is one of selenium and tellurium. 6. The toothed belt according to claim 1, wherein the metal dialkyldithiocarbamate is tellurium diethyldithiocarbamate. 7. The toothed belt according to claim 1, wherein the thiuram vulcanization accelerator is tetramethylthiuram disulfide and dipentamethylenethiuram tetrasulfide. 8. The method according to claim 1, wherein the vulcanization accelerator is zinc white.
The toothed belt according to claim 1, wherein: 9. The method according to claim 1, wherein the core is made of high-strength glass fiber.
The toothed belt according to claim 1, wherein: 10. The canvas is a woven fabric having nylon yarns.
The toothed belt according to claim 1, wherein: 11. The canvas is a woven fabric having aramid yarn.
The toothed belt according to claim 1, wherein: 12. The canvas according to claim 1, wherein the canvas is a nylon yarn and an aramid yarn.
2. The woven fabric according to claim 1, wherein
Toothed belt.