JP2000310295A - V belt for high-load transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability of a transmission belt by improving adhesion treatment of a conductor. SOLUTION: This V belt is constituted by engaging and fixing a large number of blocks 8, 8, etc., on a pair of endless tension bands 1, 1, on both sides with a specified pitch and with specified intervals in the belt length direction. In this case, each of the tension bands 1 is constituted of automorphic rubber 2, conductors 3, 3, etc., buried in this automorphic rubber 2 in a state, where they are arranged with a specified pitch and with specific prescribed intervals in the cross direction of the tension band 1 and spirally wound around it in the length direction of the tension band 1, upper reinforcing cloth 4 to cover an upper surface of the automorphic rubber 2 and lower reinforcing cloth 5 to cover a lower surface of the automorphic rubber 2. Additionally, latex of carboxylated nitryl hydride rubber or nitril hydride rubber as latex of RFL to be used for adhesion treatment of the conductor, a ratio of weight of latex against weight of RF resin of an RFL solution is specified in a specified region, and density of a solid part of the RFL solution is prescribed in a prescribed region.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission belt in which a bonded core wire is embedded in the belt length direction.
A high-load transmission V-belt used in a belt transmission such as a belt-type continuously variable transmission in a general-purpose agricultural machine or an automobile, in which an adhesive-coated core is embedded in a tension band. Including technical fields.

[0002]

2. Description of the Related Art In recent years, belt type continuously variable transmissions have been developed as transmissions for agricultural machines such as combines and tractors, automobiles, and the like, from the viewpoint of improving operability during shifting and improving fuel consumption rate. Is underway. As a high-load transmission V-belt used in this type of transmission, for example, one described in Japanese Patent Application Laid-Open No. 60-49151 is known.

In this device, a large number of blocks are locked and fixed at a predetermined pitch and a predetermined interval in a belt length direction in a pair of endless tension bands on both sides, as shown in FIG. On the upper and lower surfaces of each of the tension bands A, a number of upper surface grooves a and lower surface grooves b provided so as to extend in the belt width direction are respectively provided in the belt length direction (the left-right direction in the figure).
Are arranged at predetermined pitches and at predetermined intervals.
On both sides of each of the blocks B, a slit-shaped fitting portion c penetrating in the belt length direction is provided so as to extend in the belt width direction, and an upper edge d of the fitting portion c is provided.
Are engaged with the upper surface groove a of each of the tension bands A, and the lower edge portion e is engaged with the lower surface groove b.
Are locked and fixed to both tension bands A, A. And FIG.
As shown in FIG. 7, each of the tension bands A has a shape-retaining layer f, and a core wire g subjected to an adhesive treatment is embedded in the shape-retaining layer f so as to extend in the belt length direction, and The upper and lower surfaces of the shape-retaining layer f are covered with an upper reinforcing cloth k and a lower reinforcing cloth i, respectively, as reinforcing cloths, which can withstand high-load transmission.

An aromatic polyamide fiber is used as the fiber material of the cord g, but the aromatic polyamide fiber is difficult to adhere to rubber because the fiber surface is inactive. JP-A-5-339548 discloses a polymer containing 2,3-dichloro-1,3-butadiene (hereinafter referred to as "2,3-butadiene"), which has a high affinity for aromatic polyamide fibers and excellent wettability. D
It describes that an aromatic polyamide fiber is adhered by a resorcinol-formalin latex (hereinafter, referred to as “RFL”) solution containing a latex of “CB”.

[0005]

However, there are a few problems.
-Since the DCB itself is a hard polymer, the bonded core wire g is very hard and highly rigid. Therefore, when the V belt is wound around the pulley and the tension band A is bent, the core g is bent in multiple steps inside the tension band A, and the core g is broken from the bent portion. There is. Also, when the block B locked and fixed by the locking portion of the tension band A swings in the length direction of the tension band A,
The tension band A receives a shearing force in the thickness direction by the upper edge d and the lower edge e of the block B, whereby bending deformation is applied to the core wire g, and the above problem may occur. further,
If the RFL coating covering the core wire is hard, the RFL coating cannot cope with the rubber distortion which undergoes severe bending deformation, and there is a problem that the RFL coating may be cracked.

SUMMARY OF THE INVENTION The present invention has been made in view of the foregoing, and it is an object of the present invention to improve the durability of a power transmission belt by improving a bonding process of a cord.

[0007]

According to the present invention, hydrogenated nitrile rubber or carboxylated hydrogenated nitrile rubber latex is used as the latex of RFL used for the bonding process of the core wire of the power transmission belt.
The ratio of the weight of the latex to the weight of the formaldehyde resin is within a predetermined range, and the concentration of the solid content of the RFL solution is within a predetermined range.

More specifically, the invention according to claim 1 includes an endless tension band, and a number of blocks fixed to the tension band at a predetermined pitch in a belt length direction, wherein the tension band has a lengthwise direction. Embedded therein is a core wire formed of an organic fiber and subjected to an adhesive treatment. The core wire is immersed in a first solution containing an epoxy compound or an isocyanate compound, and the first solution is 1st to pull up and heat
Dipping into a second solution (RFL solution) containing a first coating formed on the fiber surface by the treatment, an initial condensate of resorcinol and formaldehyde, and a latex of hydrogenated nitrile rubber or carboxylated hydrogenated nitrile rubber; Second
A second coating (RFL coating) formed on the first coating by the second process of pulling up from the solution (RFL solution) and heating
The second solution (RFL solution) has a solid content of latex of 150 parts by weight or more and 200 parts by weight of 100 parts by weight of the initial condensate of resorcinol and formaldehyde.
Wherein the solid content of the second solution (RFL solution) is not less than 10% by weight and not more than 15% by weight. It is a belt.

In the above structure, the first coating containing the epoxy compound or the isocyanate compound is formed on the surface of the organic fiber forming the core wire, thereby improving the wettability of the surface of the fiber. Becomes easier.

Further, since the latex component of RFL is a latex of hydrogenated nitrile rubber or carboxylated hydrogenated nitrile rubber, the latex component is 2,2.
The second coating (RFL coating) formed on the fiber is softer than when 3-DCB is used. Therefore, the bending stiffness of the core wire can be kept low, and even if the tension band is bent by winding the belt around the pulley, the core wire is bent in multiple steps inside the tension band as in the related art. There is no. In addition, even if the core wire embedded in the tension band is subjected to bending deformation by swinging the block locked and fixed by the locking portion of the tension band in the length direction of the tension band, as in the prior art, the bending is performed. It does not take the form in which the core wire is bent at the part. Further, since the second coating (RFL coating) is soft, it can cope with the rubber distortion which undergoes severe bending deformation, and the second coating (RFL coating) does not crack as in the prior art. .

The ratio between the weight of the initial condensate of resorcinol and formaldehyde and the weight of the solid content of the latex is in an appropriate range, and the concentration of the solid content in the second solution (RFL solution) is also in an appropriate range. In addition, the amount of adhesive attached to the core wire can be reduced. Therefore, by lowering the bending rigidity of the core wire, it is possible to prevent the breakage of the core wire due to refraction. That is, if the solid content of the latex is less than 150 parts by weight based on 100 parts by weight of the initial condensate of resorcinol and formaldehyde, the resin component of the second coating (RFL coating) formed on the fiber surface increases, and this is When the thermosetting is performed during the traveling, the rigidity of the core wire is increased. On the other hand, if it is higher than 200 parts by weight, the latex component of the second solution (RFL solution) is increased, so that the viscosity of the solution is increased, and thereby the RF to the core wire is increased.
As the amount of L attached increases, the rigidity of the core wire also increases. If the concentration of the solid content of the second solution (RFL solution) is lower than 10% by weight, the amount of RFL adhered to the core wire is reduced, which hinders the adhesion between the core wire and the shape-retaining rubber of the tension band. Become.
On the other hand, if the content is higher than 15% by weight, the amount of RFL attached to the core wire increases, and the rigidity of the core wire increases.

Here, the organic fibers forming the core wire are not particularly limited, but mainly include synthetic fibers such as polyester fibers, aromatic polyamide fibers, and polybenzobisoxazole fibers (PBO). be able to.

The isocyanate compound to be used in the first treatment is not particularly limited. Isocyanates can be suitably used. Further, a polyhydric alcohol-added polyisocyanate obtained by reacting such a polyisocyanate with a compound having two or more active hydrogens in the molecule, such as trimethylolpropane, pentaneerythritol, or the like; A blocked polyisocyanate obtained by reacting a blocking agent such as an alcohol or a secondary amine to block an isocyanate group of the polyisocyanate can also be suitably used as the polyisocyanate compound.

Similarly, the epoxy compound is preferably a polyepoxy compound having two or more epoxy groups in the molecule. Examples thereof include polyhydric alcohols such as ethylene glycol, glycerin, sorbitol and pentaerythritol, and polyepoxy compounds such as polyethylene glycol. Reaction products of alkylene glycol with halogen-containing epoxy compounds such as epichlorohydrin, and polyhydric phenols such as resorcinol, bis (4-hydroxyphenyl) dimethylethane, phenol / formamide resin, resorcin / formamide resin, and phenolic resin A reaction product of a compound with a halogen-containing epoxy compound such as epichlorohydrin is preferably used.

Further, a mixture of the above isocyanate compound and epoxy compound or a mixture of rubber latex may be used.

The molar ratio of resorcinol to formaldehyde is preferably in the range of 1: 0.5 to 3,
Considering the balance between the rigidity of the core wire and the adhesiveness, 1: 1 to 1
More preferably, it is in the range of 1.5.

The hydrogenated nitrile rubber used as the latex component of the RFL is obtained by hydrogenating a conjugated diene unit of an unsaturated nitrile-conjugated diene copolymer rubber. Similarly, the carboxylated hydrogenated nitrile rubber is a conjugated diene unit portion of an unsaturated nitrile-conjugated diene-ethylenically unsaturated monomer three-dimensional copolymer rubber or an unsaturated nitrile-ethylenically unsaturated monomer-based copolymer rubber. Is hydrogenated. These nitrile group-containing highly saturated rubbers can be obtained by using ordinary polymerization methods and ordinary hydrogenation methods, but the present invention does not particularly limit the production method.

The type of the shape-retaining rubber constituting the tension band is not particularly limited, but may be natural rubber, styrene / butadiene rubber, chloroprene rubber, acrylonitrile / butadiene rubber, ethylene / propylene rubber, chlorinated polyethylene. And chlorosulfonated polyethylene, epichlorohydrin rubber, fluororubber, and a hydrogenated rubber composed of an ethylenically unsaturated nitrile-conjugated diene polymer mixed with zinc methacrylate. These rubbers are blended with various reinforcing fillers, anti-aging agents, plasticizers, vulcanization aids, processing aids and the like.

According to a second aspect of the present invention, in the high-load transmission V-belt according to the first aspect, the tension band is at least a rubber composition mainly containing a hydrogenated nitrile rubber cross-linked by an organic peroxide. The core wire is formed on the second coating (RFL coating) by a third treatment in which the core wire is dipped in a third solution containing rubber and a thermosetting resin compound, pulled up from the third solution and heated. A high-load transmission V-belt comprising a third coating to be applied.

According to the above configuration, the resin component contained in the third coating reacts with the resorcinol-formaldehyde resin of RFL, whereby the third coating and the second coating (RFL coating) are firmly adhered to each other. Further, the rubber component contained in the third coating is diffused into the shape-retaining rubber layer forming the tension band, so that the third coating and the shape-retaining rubber layer are firmly adhered to each other. Therefore, by providing the third coating, the adhesiveness of the core wire to the shape-retaining rubber of the tension band can be improved.

Further, since the third coating is formed on the second coating (RFL coating) of the core wire, the second coating (RFL coating) is protected by the third coating, and the organic coating contained in the shape-retaining rubber. It is not degraded by peroxide.

Here, the organic peroxide is not particularly limited, but may be di-t-butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy). ) Hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne and the like.

The rubber contained in the third solution includes:
There is no particular limitation, and nitrile rubber, chloroprene, chlorinated polyethylene, chlorosulfonated polyethylene and the like are preferably used.

The initial condensate of the thermosetting resin compound contained in the third solution is not particularly limited, and a phenol resin, an isocyanate resin, an epoxy resin or the like is preferably used.

According to a third aspect of the present invention, there is provided a power transmission belt in which a core wire formed of organic fibers and subjected to an adhesive treatment is embedded in the belt length direction, wherein the core wire contains an epoxy compound or an isocyanate compound. A first coating formed on the fiber surface by a first treatment in which the core wire is immersed in a first solution, pulled up from the first solution and heated, a precondensate of resorcinol and formaldehyde, and a hydrogenated nitrile rubber or carboxyl A second coating formed on the first coating by a second treatment of immersing in a second solution (RFL solution) containing a latex of hydride nitrile rubber and pulling up from the second solution (RFL solution) and heating (RFL coating), and the second solution (RFL solution) is a latex based on 100 parts by weight of an initial condensate of resorcinol and formaldehyde. Shape content has been formulated so that 200 parts by weight or less to 150 parts by weight and the second solution concentration of solids (RFL solution) is 10 wt% or more 15
The transmission belt is characterized in that the weight is not more than% by weight.

With the above configuration, the operation and effect of the invention described in claim 1 are similarly exhibited in the power transmission belt in which the core wire subjected to the adhesive treatment is embedded, and the durability of the power transmission belt is improved. That is, since the latex component of the RFL used for the bonding process of the core wire is a latex of a hydrogenated nitrile rubber or a carboxylated hydrogenated nitrile rubber, the second coating (RFL coating) formed on the fiber becomes soft. Therefore, the bending rigidity of the core wire can be suppressed low,
Even if the belt is wound around the pulley and bent, the core wire does not take a form bent in multiple steps inside the belt. Further, since the second coating (RFL coating) is soft, the second coating (RFL coating) can cope with the distortion of rubber which is subjected to severe bending deformation.
There is no occurrence of cracking of the coating (RFL coating). Further, the ratio of the weight of the initial condensate of resorcinol and formaldehyde to the weight of the solid content of the latex is set in an appropriate range, and the concentration of the solid content of the second solution (RFL solution) is also set in an appropriate range. The amount of adhesive applied to the core can be suppressed to a small value, and the core is not bent and damaged by lowering the bending rigidity of the core.

As described above, according to the first aspect of the present invention, the first coating containing the epoxy compound or the isocyanate compound is formed on the surface of the organic fiber forming the core wire, whereby the wettability of the fiber surface is reduced. The improved properties facilitate RFL deposition on the fibers. Further, since the latex component of the RFL is a latex of a hydrogenated nitrile rubber or a carboxylated hydrogenated nitrile rubber, the RFL coating formed on the fibers becomes soft. Therefore, the bending rigidity of the core wire can be suppressed low, and even if the tension band is bent by wrapping the belt around the pulley, the core wire does not take a multi-stage bent inside the tension band. Furthermore, even if the core wire embedded in the tension band is subjected to bending deformation due to the block locked and fixed by the locking portion of the tension band swinging in the length direction of the tension band, the core wire is formed at that portion. It does not take a bent form. And
Since the second coating (RFL coating) is soft, the second coating (RFL coating) can cope with the distortion of rubber subjected to severe bending deformation, and the second coating (RFL coating) does not crack. Also, since the ratio of the weight of the initial condensate of resorcinol and formaldehyde to the weight of the solid content of the latex is in an appropriate range, and the concentration of the solid content in the second solution (RFL solution) is also in an appropriate range, The amount of the adhesive adhered to the core is suppressed to a small value, and the bending rigidity of the core is reduced to prevent breakage due to refraction of the core. From the above, the durability of the high load transmission V-belt is improved.

According to the second aspect of the present invention, the resin component contained in the third coating reacts with the resorcinol-formaldehyde resin of RFL to form the third coating and the second coating (R).
FL coating), and the rubber component contained in the third coating diffuses into the shape-retaining rubber layer forming the tension band, whereby the third coating and the shape-retaining rubber layer are firmly adhered to each other. .
Therefore, by providing the third coating, the adhesiveness of the core wire to the shape-retaining rubber of the tension band can be improved. Further, since the third coating is formed on the second coating (RFL coating) of the core wire, the second coating (RFL coating) is protected by the third coating, and the organic peroxide contained in the shape-retaining rubber. It is not degraded. From the above, the durability of the high load transmission V-belt is further improved.

According to the third aspect of the present invention, in the transmission belt in which the core wire is embedded, the bending rigidity of the core wire is suppressed to be low, so that even if the belt is wound around a pulley and bent, the core wire is formed inside the belt. Does not take the form of being bent in multiple steps. Further, since the second coating (RFL coating) is soft, the second coating (RFL coating) can cope with the distortion of the rubber which undergoes severe bending deformation, and the second coating (RFL coating) does not crack. Further, the ratio of the weight of the initial condensate of resorcinol and formaldehyde to the weight of the solid content of the latex is set in an appropriate range, and the concentration of the solid content of the second solution (RFL solution) is also set in an appropriate range. The amount of the adhesive adhered to the core is suppressed to a small value, and the bending rigidity of the core is reduced to prevent breakage due to refraction of the core. From the above, the durability of the transmission belt is improved.

[0029]

Embodiments of the present invention will be described below in detail with reference to the drawings. (Embodiment 1) FIG. 1 shows a high load transmission V-belt A according to Embodiment 1 of the present invention. Although not shown, the V-belt A is used when constructing a belt-type continuously variable transmission that is wound around two drive pulleys on the driving side and the driven side, each of which includes a fixed sheave and a movable sheave. A large number of blocks 8, 8,... Are locked and fixed at a predetermined pitch and at a predetermined interval in the belt length direction on a pair of endless tension bands 1, 1 on both sides.

Each of the tension bands 1 is embedded in a shape-retaining rubber 2 and is arranged in the shape-retaining rubber 2 at a predetermined pitch and a predetermined interval in the width direction of the tension band 1. ., An upper reinforcing cloth 4 covering the upper surface of the shape-retaining rubber 2, and a lower reinforcing cloth 5 covering the lower surface of the shape-retaining rubber 2.

The shape-retaining rubber 2 is made of a rubber composition mainly composed of hydrogenated nitrile rubber (H-NBR) using dicumyl peroxide as a crosslinking agent, and the upper reinforcing cloth 4 and the lower reinforcing cloth 5 It is a woven woven fabric,
Adhesion treatment with rubber glue is performed.

The core wire 3 is made of four 1000-de aramid fibers (trade name: Technora, Teijin Co., Ltd.) at 10 c.
It is a braided cord configured to allow 30 braids per m, and various physical properties are as shown in Table 1. And
The core wire 3 has been subjected to the following bonding treatment.

[0033]

[Table 1] First, a first solution in which polyglycerin polyglycidyl ether (epoxy resin compound) and 1-cyanoethyl-2-ethyl-4-methylimidazole (catalyst) were mixed with toluene as a solvent so as to have a composition shown in Table 2 was used. After the core wire 3 is immersed and pulled up, the core wire 3 is held at a temperature of 250 ° C. for 72 seconds to form a film (first film) of an epoxy resin compound on the surface of the aromatic polyamide fiber.

[0034]

[Table 2] Next, an initial condensate of resorcinol-formaldehyde (resorcinol and formalin are dissolved in water and mixed with sodium hydroxide as a catalyst) and a carboxylated hydrogenated nitrile rubber having a solid content of 40% so as to have the composition shown in Table 3. The core wire 3 is immersed in a second solution (RFL solution) in which latex and sodium dialkylsulfosuccinate (surfactant) are mixed with water as a solvent, pulled up, and then held at a temperature of 245 ° C. for 72 seconds. Forming a second coating (RFL coating) on the first coating; In addition, RFL to the fiber
This second solution (RFL solution) in order to eliminate uneven adhesion of
The immersion and heating processes are performed twice.

[0035]

[Table 3] Finally, the core wire 3 is immersed in a third solution obtained by diluting an adhesive containing a phenol resin, an epoxy resin, and a nitrile rubber (manufactured by Toyo Kagaku Kenkyusho Co., Ltd .: Metalok N20) with methyl ethyl ketone so as to have the composition shown in Table 4. And then pull it up,
The solution is kept for 72 seconds in an atmosphere at a temperature of 100 ° C. to disperse the solvent.

[0036]

[Table 4] At this time, the heat treatment temperature after immersion in the first solution is 240 ° C.
The temperature is preferably set to not less than 260 ° C. Heat treatment temperature is 24
If the temperature is lower than 0 ° C., the first coating is not sufficiently formed on the fiber surface, and if the temperature is higher than 260 ° C., the epoxy resin compound is decomposed by heat. From such a viewpoint, it is more preferable to set the heat treatment temperature to 245 ° C or higher and 250 ° C or lower. And the heat treatment time is 60 seconds or more and 80
It is good to be less than seconds. If the heat treatment time is shorter than 60 seconds, the formation of the first coating on the fiber surface is not sufficient, and if it is longer than 80 seconds, the reaction of the epoxy resin compound proceeds excessively, and the effect of activating the fiber surface is weak. Because it becomes. The temperature of the heat treatment after immersion in the second solution (RFL solution) is preferably 235 ° C. or more and 255 ° C. or less. If the heat treatment temperature is lower than 235 ° C, the second coating (RFL coating)
The crosslinking reaction of the resin component does not proceed sufficiently and
If it is higher, the rubber component of the second coating (RFL coating) is deteriorated by heat. From such a viewpoint, it is more preferable to set the heat treatment temperature to 240 ° C. or higher and 250 ° C. or lower. The heat treatment time is preferably set to 60 seconds or more and 80 seconds or less. If the heat treatment time is shorter than 60 seconds, the second
This is because the crosslinking reaction of the resin component of the coating (RFL coating) does not proceed sufficiently, and if it is longer than 80 seconds, the rubber component of the second coating (RFL coating) is deteriorated by heat. Further, the temperature of the heat treatment after immersion in the third solution is 90 ° C. or more.
The temperature is preferably set to 0 ° C. or lower. If the heat treatment temperature is lower than 90 ° C., the formation of the third coating is not sufficient, and if it is higher than 110 ° C., the crosslinking reaction of the resin component of the third coating excessively progresses, and the adhesive performance with rubber deteriorates. It is. From such a viewpoint, the heat treatment temperature is more preferably set to 95 ° C. or more and 105 ° C. or less. The heat treatment time is preferably set to 60 seconds or more and 80 seconds or less. If the heat treatment time is shorter than 60 seconds, the formation of the third film is not sufficiently performed, and if the heat treatment time is shorter than 80 seconds, the crosslinking reaction of the resin component of the third film excessively proceeds, and the adhesive performance with rubber is deteriorated. It is.

On the upper surface of each tension band 1, a number of upper surface grooves 6, 6,...
On the lower surface, a plurality of lower grooves 7, 7,... Each having an arc-shaped cross section corresponding to the upper grooves 6, 6,. Further, they are provided so as to extend in the belt width direction at predetermined intervals.

On the other hand, each of the blocks 8 has a substantially inverted trapezoidal plate shape, and both side surfaces thereof are slidable contact portions 9, 9 slidably contacting the groove surface of the speed change pulley. On both sides of each block 8, slit-shaped fitting portions 10, 10 penetrating in the belt length direction and extending in the belt width direction are provided in a state opened to the side. I have. The upper edge portion of each fitting portion 10 has a convex cross section projecting downward, and is formed as a downward protruding ridge 11 as an engaging portion that engages with the upper surface groove 6 of the tension band 1. ing. The lower edge of each of the fitting portions 10 has an arc-shaped cross section that protrudes upward, and has an upwardly projecting ridge 12 as an engaging portion that engages with the lower surface groove 7 of the tension band 1. Have been.

Next, the operation and effect will be described.

The aromatic polyamide fiber forming the core wire 3 has a poor affinity for an RFL solution or the like because the fiber surface is inactive. Therefore, the first surface containing an epoxy compound on the fiber surface
The formation of the coating improves the wettability of the fiber surface and facilitates the attachment of RFL.

Since the latex component of the RFL solution as the second solution is a latex of carboxylated hydrogenated nitrile rubber, 2,3-D is used as the latex component.
The second coating (RFL coating) formed on the fiber is softer than when CB is used. Therefore, the bending rigidity of the core wire 3 can be suppressed low, and even if the tension band 1 is bent by winding the belt around the pulley, the core wire 3 is bent in multiple steps inside the tension band 1 as in the related art. It does not take any form. In addition, even if the core wire 3 embedded in the tension band 1 is bent by the block 8 locked and fixed by the locking portion of the tension band 1 swinging in the length direction of the tension band 1, the conventional method is used. Neither does the core 3 take a bent form at that portion as in the technology. Then, the second coating (RFL
Since the film is soft, it is possible to cope with the distortion of the shape-retaining rubber 2 which is subjected to severe bending deformation, and the second film (RFL film) is not cracked unlike the related art.

Further, the solid content of the latex is 158 parts by weight based on 100 parts by weight of the initial condensate of resorcinol and formaldehyde, and the second solution (RFL solution)
Has a solid content of 11.2%, so that the R on the core wire 3 is maintained within a range that does not impair the adhesiveness of the core wire 3 to the shape-retaining rubber 2.
The amount of FL attached is reduced. Therefore, the bending rigidity of the core wire 3 is reduced, and the core wire 3 is not bent and damaged.

The phenolic resin component contained in the third coating reacts with the resorcin-formaldehyde resin of RFL to form the third coating and the second coating (RFL coating).
And firmly adhere. In addition, the nitrile rubber component contained in the third coating is diffused into the two rubber layers forming the tension band 1, so that the third coating and the two rubber layers are firmly adhered to each other. Therefore, the adhesiveness of the core wire 3 to the shape retaining rubber 2 of the tension band 1 is improved by the third coating.

Then, the second coating (RFL coating) of the core wire 3
Since the third coating is formed thereon, the second coating (RFL
The third coating is protected by the third coating, and is less likely to be degraded by the organic peroxide contained in the rubber 2.

By improving the bonding process of the core wire 3, the high load transmission V-belt A becomes excellent in durability. <Example> The high-load transmission V-belt A according to Embodiment 1 was used as Example 1 and the second solution (RFL
Example 2 was a high load transmission V-belt B having the same configuration as in Example 1 except that the latex component of the solution) was a latex of hydrogenated nitrile rubber having a solid content of 40% (Table 5, Table 5).
6, 7). A high-load transmission V-belt C having the same configuration as in Example 1 except that the formulations of the first solution and the second solution (RFL solution) in the bonding process of the core wire were the treatment solutions shown in Tables 5 and 6, respectively. Was used as a comparative example (see Tables 5, 6, and 7).

[0046]

[Table 5]

[0047]

[Table 6]

[0048]

[Table 7] -Bending rigidity test of core wire-The bending stiffness of the bonded core wire used in Examples 1, 2 and Comparative Example was measured (using a pure bending tester KES manufactured by Kato Tech Co., Ltd.). The measurement was performed for (a) a sample without heat treatment, (b) a sample with heat treatment at 120 ° C. for 168 hours, and (c) a sample with heat treatment at 150 ° C. for 168 hours. Figure 2 shows the result.
Shown in

As is apparent from FIG.
It can be seen that the core wire of the comparative example has lower rigidity than the core wire of the comparative example. That is, the first solution of the bonding process of the core wire is a solution of an epoxy resin compound, and the latex component of the second solution (RFL solution) is a carboxylated hydrogenated nitrile rubber or a latex of a hydrogenated nitrile rubber.
The solution was a solvent-based isocyanate resin compound solution, and the latex component of the second solution (RFL solution) was 2,3-DC
It was confirmed that the rigidity of the core wire could be made lower than that of B. In addition, it was also confirmed that the rigidity of the core wires of Examples 1 and 2 was increased by performing the heat treatment, but the absolute value could be suppressed lower than the rigidity of the core wire of the comparative example. -Core wire pull-out adhesion test-Each core wire used in Examples 1 and 2 and Comparative Example was subjected to a pull-out adhesion test. The rubber to be adhered was a compound of hydrogenated nitrile rubber using dicumyl peroxide as a crosslinking agent. As shown in FIG. 3, four molds 15 were prepared in which rectangular grooves 13 for rubber filling and narrow grooves 14, 14,... For core set on both sides of each rectangular groove 13 were prepared. . A plurality of slit-shaped grooves provided on one of the opposed side frames of the rectangular mold frame 16 are wrapped with core wires subjected to an adhesive treatment, and the core wires set in the rectangular mold frame 16 as shown in FIG. Was sandwiched between a pair of molds 15 and 15. At this time,
The narrow grooves 14, 14 of the pair of dies 15, 15 were set to face each other, and the cores were set so as to pass through the holes formed. The rectangular grooves 13, 13 were filled with an unvulcanized hydrogenated nitrile rubber composition, and the whole was sandwiched between a pair of plate-shaped dies, and press-vulcanized at 160 ° C. for 25 minutes. Subsequently, each of the molds 15 is removed from the mold frame 16 and, as shown in FIG. 5A, a rectangular parallelepiped test piece 18 (11 cm) embedded so that a plurality of core wires 17, 17,. ×
2 cm × 1 cm). Then, as shown in FIG. 5 (b), the cords 17, 1 protruding to one side of the test piece 11 are provided.
After cutting off 7,..., The protruding length from the test piece 18 was adjusted to 7 cm. The test piece 18 thus obtained was set on a drawing jig 19 as shown in FIG. 6, and the upper end of the drawing jig 19 and the core wire 17 were sandwiched between upper and lower chucks of a tensile tester, respectively. The core wire was pulled out from the rubber piece at 50 mm / min. The maximum tension at this time is
The shear adhesive strength of the core wire 17 per 1 cm which is the thickness of the test piece 18 is obtained. The measurement was performed at 25 ° C. in a 1
The measurement was performed 0 times, 10 times in a 120 ° C. temperature atmosphere, and the average value was used as data. FIG. 7 shows the result.

According to FIG. 7, the core wire pull-out adhesive strength of each of the core wire of Example 1, the core wire of Example 2, and the core wire of Comparative Example was almost constant at either 25 ° C. or 120 ° C. ambient temperature. It was confirmed that they exhibited the same level of adhesive strength. -Flat belt running test-Flat belts of the same configuration in which the core wires of the high-load transmission V-belts according to Example 1, Example 2, and Comparative Example were embedded were prepared, and running tests under the following three conditions were performed. (See FIG. 8).
The matrix rubber of the flat belt was a rubber composition of hydrogenated nitrile rubber using dicumyl peroxide as a cross-linking agent, and three core wires were embedded at a pitch of 0.75 mm in the belt width direction.

Condition (a): A flat belt is wound around two pulleys having a diameter of 40 mm, and tension is applied to the belt by pulling the driven pulley at 1373 N.
And run until the belt is cut.

Condition (b): A flat belt is wound around two pulleys having a diameter of 60 mm, and tension is applied to the belt by pulling the driven pulley at 1177 N.
Run until the belt cuts at ℃. Note that 11
The ambient temperature of 0 ° C. is close to the actual use condition of the high load transmission V-belt.

Condition (c): A flat belt is wound around two pulleys having a diameter of 60 mm, and tension is applied to the belt by pulling the driven pulley at 981 N.
After running for 100 hours, the residual strength of the belt is measured. Note that this condition is closer to the actual use condition of the high load transmission V-belt than the conditions (a) and (b).

FIG. 9 shows the results of the running life of the belt under the conditions (a) and (b). According to this, under the condition (a), the running life of the belt is almost the same level in each of Example 1, Example 2, and Comparative Example. This is because, because the ambient temperature was 25 ° C., the matrix rubber of the flat belt did not soften due to heat, and the difference in the bonding process of the core wire did not become a factor that governs the belt running life.

On the other hand, under the condition (b), the flat belt using the core of Example 1 and the flat belt using the core of Example 2 run as compared with the flat belt using the core of the comparative example. Life is remarkably long. In other words, it was confirmed that under the actual use temperature atmosphere of the high-load transmission V-belt, the belt's bending fatigue resistance was significantly improved by suppressing the rigidity of the core wire even when the adhesive strength was the same level. Was done.

FIG. 10 shows the result of the condition (c) regarding the strength of the belt before and after the running of the belt. In addition, the power is the core 1
It is converted to the strength per book, and the residual strength ratio of the belt after running is calculated and also shown. As shown in FIG. 10, in the flat belt using the core wire of the comparative example, the residual strength ratio was 72.0.
%, On the other hand, the flat belt using the core of Example 1 has a residual strength rate of 97.5%, and the flat belt using the core of Example 2 has an extremely high rate of 82.4%. That is, it was confirmed that the result of the flat belt running test under the condition (b) was also satisfied under the condition (c).

Under the conditions (b) and (c), the flat belt using the core of Example 1 is more excellent in bending fatigue resistance than the flat belt using the core of Example 2. This is because carboxylated hydrogenated nitrile rubber contains a carboxyl group showing polarity, so that it has higher affinity for both the fiber side and the third coating layer side than hydrogenated nitrile rubber, and has high adhesiveness. It is. -V-belt running test for high load transmission- V-belt A according to the first embodiment, V-belt B according to the second embodiment
A belt running test was performed on the V belt C according to the comparative example. The belt running tester has a drive pulley 20 having a diameter of 118.7 mm and a diameter of 67.7 mm as shown in FIG.
Driven pulley 21 is provided. In addition, a load is applied to the driven pulley in the horizontal direction, whereby tension is applied to the belt. These two pulleys are housed in a thermostat 22, which is provided with an air outlet 23 having a diameter of 40 mm and an air outlet 24 having a diameter of 90 mm. The running test was performed by winding the V belt 25 around both pulleys, applying a load of 1108 N to the driven pulley, and running the driven pulley until the belt was cut. In addition, the rotation speed of the drive shaft was set to 6000 rpm, and air at 145 to 150 ° C. was blown into the constant temperature bath from the air outlet so that the belt temperature became 130 ° C. FIG. 12 shows the running life of each belt.

As can be seen from FIG. 12, the belt running life of Examples 1 and 2 is significantly longer than that of Comparative Example. That is, it was confirmed that even when the adhesive force was the same level, the durability of the high-load transmission V-belt could be improved by suppressing the rigidity of the core wire to be low.

The reason why Example 1 is superior in bending fatigue resistance to Example 2 is for the same reason as the result of the above-mentioned flat belt. (Embodiment 2) FIG. 13 shows a toothed belt D according to Embodiment 2 of the present invention. The toothed belt D has a tooth rubber 31 disposed at an equal pitch inside the belt and a back rubber 3 outside the belt.
2. Consisting of a core wire 33 buried in the longitudinal direction of the belt, a reinforcing cloth 34 covering the tooth rubber 31 and the tooth bottom 32.

Here, as the tooth rubber 31 and the back rubber 32, a rubber compound mainly composed of hydrogenated nitrile rubber (H-NBR) using dicumyl peroxide as a crosslinking agent is used. Further, the reinforcing cloth 34 is a woven nylon fabric subjected to a wooly process, and is subjected to an adhesive treatment with RFL and rubber paste. And as the core wire 33, 1
It is formed of an aromatic polyamide fiber (trade name: Tecnora, Inc., Technora) having a configuration of 500 de / 2, and is subjected to the same adhesive treatment as in the first embodiment.

Next, the operation and effect will be described.

The aromatic polyamide fiber forming the core wire 33 has a poor affinity for an RFL solution or the like because the fiber surface is inactive. Therefore, by forming the first coating containing the epoxy compound on the fiber surface, the wettability of the fiber surface is improved, and the adhesion of the RFL is facilitated.

In the bonding process of the core wire 33, RF
Since the latex component of L is a latex of carboxylated hydrogenated nitrile rubber, RF formed on the fiber
The L film becomes soft. Therefore, the bending rigidity of the core wire 33 can be suppressed low, and even if the belt is wound around the pulley and bent, the core wire 33 does not take a form in which the core wire 33 is bent in multiple steps inside the belt. In addition, the second coating (R
Since the FL coating is soft, it can cope with the distortion of the tooth rubber 31 and the back rubber 32 which undergo severe bending deformation.
The second coating (RFL coating) is not cracked.

Since the solid content of the latex is set to 170 parts by weight based on 100 parts by weight of the initial condensate of resorcinol and formaldehyde, and the solid content of the second solution (RFL solution) is set to 10.8%. The amount of RFL adhered to the core wire 33 is reduced within a range that does not impair the adhesiveness of the core wire 33 to the tooth rubber 31 and the back rubber 32. Therefore,
The bending rigidity of the core wire 33 is reduced, and the core wire 33 is not bent and damaged. That is, the operation and effect of the high-load transmission V-belt of the first embodiment are described below.
Plays similarly. Therefore, by improving the bonding process of the core wire 33, the toothed belt D becomes excellent in durability. (Other Embodiments) In the above embodiment, the high load transmission V belt and the toothed belt are used. However, the present invention is not limited to these belts.
Wrapped V-belts, V-ribbed belts and other V-belts,
It can also be obtained in other types of power transmission belts in which a bonded core wire such as a flat belt is embedded.

The high-load transmission V-belt is not limited to the one according to the first embodiment, but is shown in FIG.
A tension band 42 is provided on one side of the block 41 as shown in FIG.
A high-load transmission V-belt D40 in which a large number of C-shaped blocks provided with fitting grooves 43 for fitting therein are locked and fixed at a predetermined pitch to a tension band 42, or as shown in FIG.
Also included is a high-load transmission V-belt E50 in which an upper block 52 and a lower block 53 are respectively arranged above and below and fixed with a fastening member 54 such as a bolt or a rivet.

[Brief description of the drawings]

FIG. 1 is a perspective view of a high-load transmission V-belt A according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing a result of a bending rigidity test of a core wire.

FIG. 3 is a perspective view of a mold for obtaining a test piece used in a core wire pull-out adhesion test.

FIG. 4 is a plan view showing a state in which a mold for obtaining a test piece used for a core wire pull-out adhesion test is set in a mold frame, and a core wire is set.

FIG. 5 (a) is a perspective view of a test piece for a core wire adhesion test in a state where the core wires protrude on both sides of a rubber piece, and FIG.
(B) is a perspective view of the test piece for bonding a core wire in a state where one core wire is cut off.

FIG. 6 is a perspective view showing a state where a test piece for bonding a core wire is mounted on a test jig.

FIG. 7 is a view showing a result of an adhesive force in a core wire pull-out adhesive test.

FIG. 8 is a diagram showing a layout of a flat belt running tester.

FIG. 9 is a diagram showing the results of a belt running life under conditions (a) and (b) of a flat belt running test.

FIG. 10 is a diagram showing a result of belt residual strength under a condition (c) of a flat belt running test.

FIG. 11A is a top view showing a layout of a traveling tester for a high-load transmission V-belt, and FIG.
Is a side view of the same.

FIG. 12 is a diagram showing a result of a belt running life of a high load transmission V-belt running test.

FIG. 13 is a perspective view of a toothed belt D according to Embodiment 2 of the present invention.

FIG. 14 is a perspective view of a V-belt D for high-load transmission.

FIG. 15 is a sectional view of a high-load transmission V-belt E;

FIG. 16 is a side view showing a state of a block force applied to a lower surface groove of the tension band.

FIG. 17 is a side view showing a configuration of a conventional tension band.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 tension band 2 shape-retaining rubber 3 core wire 4 upper reinforcing cloth 5 lower reinforcing cloth 6 upper groove 7 lower groove 8 block 9 sliding contact part 10 fitting part 11 downward protruding strip 12 upward protruding strip 13 rectangular groove 14 narrow groove 15 gold Mold 16 Rectangular mold frame 17 Core wire 18 Test piece 19 Test jig 20 Drive pulley 21 Follower pulley 22 Constant temperature bath 23 Ventilation port 24 Ventilation port 25 V belt 31 Tooth rubber 32 Back rubber 33 Core wire 34 Reinforcement cloth 40 High load Transmission V-belt D 41 Block 42 Tension band 43 Fitting groove 50 High-load transmission V-belt E 51 Tension band 52 Upper block 53 Lower block 54 Fastening material a Upper surface groove b Lower surface groove c Fitting part d Upper edge e Lower edge f Shape retaining layer g Core wire i Lower reinforcing cloth k Upper reinforcing cloth

Continued on the front page (72) Inventor Hiroyuki Sakanaka 3-2-1-15 Meiwadori, Hyogo-ku, Kobe-shi, Hyogo Inside BANDO CHEMICAL CO., LTD. No. 15 Inside Bando Chemical Co., Ltd. (72) Inventor Masaaki Ogino 3-2-15 Meiwadori, Hyogo-ku, Kobe-shi, Hyogo F-term inside Bando Chemical Co., Ltd. 4F071 AA13A AA34A AA41A AA42A AA56 AC12A AH17 CA03 CB02 CC06

Claims (3)

[Claims] 1. An endless tension band, and a number of blocks fixed to the tension band at a predetermined pitch in a belt length direction, wherein the tension band is formed of organic fibers in a length direction and A core wire subjected to an adhesive treatment is embedded, and the core wire is immersed in a first solution containing an epoxy compound or an isocyanate compound, and is pulled up from the first solution and heated to perform a first process. Dipping in a second solution containing a first coating formed on the fiber surface, a precondensate of resorcinol and formaldehyde and a latex of hydrogenated nitrile rubber or carboxylated hydrogenated nitrile rubber,
The first treatment is carried out by the second treatment of pulling up from the second solution and heating.
A second coating formed on the coating, wherein the second solution has a latex solid content of 1 part by weight based on 100 parts by weight of the initial condensate of resorcinol and formaldehyde.
Characterized in that the second solution has a solids content of 10 to 15% by weight, wherein the solid content of the second solution is 50 to 200 parts by weight. V belt. 2. The V-belt for high-load transmission according to claim 1, wherein the tension band is a rubber composition mainly composed of a hydrogenated nitrile rubber cross-linked by at least an organic peroxide. The wire is provided with a third coating formed on the second coating by a third treatment of dipping in a third solution containing rubber and a thermosetting resin compound, pulling up from the third solution, and heating. A high-load transmission V-belt characterized by the following: 3. A power transmission belt in which a core wire made of organic fibers and subjected to an adhesive treatment is embedded in a belt length direction, wherein the core wire is attached to a first solution containing an epoxy compound or an isocyanate compound. A first coating formed on the fiber surface by a first treatment in which the wire is dipped, pulled up from the first solution, and heated, and an initial condensate of resorcinol and formaldehyde and a hydrogenated nitrile rubber or a carboxylated hydrogenated nitrile rubber. Dipped in a second solution containing latex and
The first treatment is carried out by the second treatment of pulling up from the second solution and heating.
A second coating formed on the coating, wherein the second solution has a latex solid content of 1 part by weight based on 100 parts by weight of the initial condensate of resorcinol and formaldehyde.
A power transmission belt which is blended so as to be 50 parts by weight or more and 200 parts by weight or less, and wherein the solid content of the second solution is 10% by weight or more and 15% by weight or less.