JP2001146942A - Transmission belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmission belt for exhibiting high transmitting force even if water is stuck on a transmitting surface, for improving a belt traveling life under a high temperature environment and low temperature environment, and for improving weatherability by laminating layers capable of roughly holding a surface roughness of a belt thickness direction of the transmitting surface which is brought into contact with a pulley. SOLUTION: In a V-ribbed belt 1 wherein a cover sail cloth 5 is laminated on a surface and a compression rubber layer 4 is disposed adjacently to a bonding rubber layer 3 in which a core wire 2 is buried along a belt longitudinal direction, a particle dispersion rubber layer 8 having at least one layer, wherein organic material particles are dispersed in the rubber, is interposed between the rubber layer 4 and a short fiber mixing rubber layer 9 wherein short fiber is dispersed in the rubber.

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,
Specifically, it is a power transmission belt including a friction transmission type such as a V-ribbed belt and a cut edge type V belt,
By laminating a layer that can roughly maintain the surface roughness of the transmission surface in contact with the pulley in the belt thickness direction, high power transmission can be achieved even if water adheres to the transmission surface. Also, the present invention relates to a power transmission belt having an improved belt running life in a low-temperature atmosphere and excellent weatherability.

[0002]

2. Description of the Related Art In recent years, due to social demands for energy saving and compactness, the ambient temperature around an engine room of an automobile has been increasing as compared with the related art. Along with this, the operating environment temperature of the V-ribbed belt has been increased.
Conventionally, V-ribbed belts are mainly made of natural rubber, styrene-
Butadiene rubber and chloroprene rubber have been used, but under a high-temperature atmosphere, there has been a problem that cracks occur early in the cured compressed rubber layer. For this reason, chlorosulfonated polyethylene rubber has been used instead of chloroprene rubber.

A V-ribbed belt using chlorosulfonated polyethylene rubber has a significantly improved belt running life in a high-temperature atmosphere and excellent heat resistance as compared with a belt using chloroprene rubber. It became clear that the belt running life under the following low temperature atmosphere was remarkably inferior. The reason for this is that conventional chlorosulfonated polyethylene rubber is a chlorosulfonated polyethylene, which contains chlorine, so that the cohesive energy of chlorine increases at low temperatures and the rubber hardens in the low temperature range, causing the rubber to harden. This is presumed to be due to lack of elasticity and easy cracking.

On the other hand, ethylene-α-olefin elastomers such as ethylene-propylene rubber (EPR) and ethylene-propylene-diene rubber (EPDM) have excellent heat resistance and cold resistance, and Although it is an inexpensive polymer, it does not have oil resistance, so it is not actively used for such applications. In dry friction transmission such as a V-ribbed belt, slippage occurs when a large amount of oil is applied, and the transmission function is impaired.
As disclosed in JP-A-345948, a transmission belt using an ethylene-α-olefin elastomer is also being studied.

Also, when the V-ribbed belt is subjected to a condition of large rotation fluctuation or a high load condition, the compressed rubber layer causes adhesive wear, and as a result, the adhesive rubber adheres to the groove bottom between the ribs to increase the slip ratio. If the desired transmission horsepower cannot be obtained or the adhesive rubber is excessively adhered, there has been a problem that the compressed rubber layer peels off. For this reason, the amount of short fibers such as cotton, nylon and polyester has been increased in the compressed rubber layer, and the amount of carbon black and the like has been increased. In addition, ceramics powder was mixed into the compressed rubber layer to cope with adhesive wear.

[0006]

However, if short fibers, carbon black, etc. are added to the compressed rubber layer, or if ceramics powder is uniformly mixed, the modulus in the belt width direction increases, and the elongation in the belt longitudinal direction increases. Will be reduced. As a result, the bending resistance of the V-ribbed belt deteriorated, and cracks occurred in the compression rubber layer at an early stage particularly during reverse bending. In addition, when water adheres to the rib surface, the friction coefficient is reduced, slipping is likely to occur, and the transmission capacity may be reduced.

The present invention addresses such a problem, and by stacking layers capable of roughly maintaining the roughness of the transmission surface in contact with the pulley in the belt thickness direction,
An object of the present invention is to provide a power transmission belt that can exhibit high power transmission even if water adheres to the transmission surface, has an improved belt running life under high-temperature atmosphere and low-temperature atmosphere, and has excellent weather resistance. I do.

[0008]

That is, in the invention of claim 1 of the present application, a cover canvas is laminated on the surface, and a compressed rubber layer is formed adjacent to an adhesive rubber layer in which a cord is embedded along the longitudinal direction of the belt. In the transmission belt arranged, in the compression rubber layer, at least one fine particle dispersion rubber layer in which inorganic material fine particles are dispersed in rubber is interposed in a short fiber mixed rubber layer in which short fibers are dispersed in rubber. Yes, the fine particle-dispersed rubber layer has a rough surface roughness and can maintain high power even if water adheres to the transmission surface by maintaining it for a long time. Locally, the modulus in the belt width direction does not increase, the elongation in the belt longitudinal direction is maintained, and the bending resistance is not hindered.

According to a second aspect of the present invention, there is provided a power transmission belt in which the inorganic material fine particles of the fine particle dispersed rubber layer are ceramic powder.

According to a third aspect of the present invention, there is provided a power transmission belt in which the fine particles of the inorganic material in the fine particle dispersed rubber layer are diatomaceous earth.

According to a fourth aspect of the present invention, there is provided a power transmission belt in which the rubber of the compressed rubber layer is a crosslinked product of an ethylene-α-olefin elastomer crosslinked with an organic peroxide.

According to the invention of claim 5 of the present application, the transmission belt is a V-ribbed belt composed of an adhesive rubber having a core buried along the belt longitudinal direction and a compression rubber layer having a plurality of rib portions extending in the circumferential direction of the belt. is there.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A V-ribbed belt 1 shown in FIG.
A core wire 2 made of a high-strength, low-elongation cord made of polyester fiber, aramid fiber, or glass fiber is embedded in an adhesive rubber layer 3, and a compression rubber layer 4 as an elastic layer is provided below the core wire. are doing. The compressed rubber layer 4 is provided with a plurality of ribs 7 having a substantially triangular cross section extending in the longitudinal direction of the belt, and a cover canvas 5 attached to the surface of the belt.

As another belt, a cut edge type V
Also used for the belt 21. As shown in FIG. 2, the belt 21 is composed of an adhesive rubber layer 24 in which a cord 23 is embedded and a compressed rubber 26, and a cover canvas 22 is further provided on each surface layer of the adhesive rubber layer 24 and the compressed rubber layer 26. Laminated.

Thus, in the compressed rubber layers 4 and 26 shown in FIGS. 1 and 2, one layer of fine particle-dispersed rubber layers 8 and 28 in which fine particles of an inorganic material are dispersed in rubber has a short fiber in which short fibers are dispersed in rubber. It is interposed in the fiber-containing rubber layers 9 and 29. The thickness of the fine particle dispersed rubber layers 8 and 28 is 0.15 to 1.0.
mm and less than 0.15 mm, it is difficult not only to manufacture the rubber layer but also to make the surface roughness of the transmission surface rough, while if it exceeds 1.0 mm, the belt lengthwise Not only does the modulus of elasticity increase, but also the elongation in the belt longitudinal direction decreases, so that the bending resistance is impaired.

The inorganic material fine particles of the fine particle dispersed rubber layers 8 and 28 are made of 001 to 100 μm silicon carbide, titanium carbide,
Carbides such as boron carbide and tungsten carbide, silicon nitride,
Nitride such as aluminum nitride, boron nitride, and titanium nitride; and oxides such as alumina, zirconia, and bevelia, and most preferably, silicon carbide and silicon nitride. Also,
A porous material such as diatomaceous earth can also be used. The addition amount of the inorganic material fine particles is 5 to 100 parts by weight of rubber.
If it is less than 5 parts by weight, there is no effect of increasing the surface roughness in the belt thickness direction.
When the amount is more than the weight part, not only the workability is deteriorated but also the durability is lowered, and even if added more, the surface roughness in the belt thickness direction does not change.

The rubber used for the compressed rubber layers 4 and 26 includes nitrile rubber, hydrogenated nitrile rubber, hydrogenated nitrile rubber to which unsaturated carboxylic acid metal salt is added together with ethylene-α-olefin elastomer, Sulfonated polyethylene, chloroprene, urethane rubber, epichlorohydrin rubber, natural rubber, CSM, A
CSM and SBR are used. Among them, ethylene-α
-Olefin elastomers are preferred.

The ethylene-α-olefin elastomer is ethylene-propylene rubber (EPR) or ethylene-propylene rubber.
A rubber composed of a propylene-diene monomer (EPDM). Examples of diene monomers include dicyclopentadiene, methylene norbornene, ethylidene norbornene, 1,4-hexadiene, cyclooctadiene, and the like.

The compressed rubber layers 4 and 26 have ethylene-
A peroxide is added as a vulcanizing agent for the α-olefin elastomer. Also, a co-crosslinking agent (co-agent)
Normal peroxides such as TIAC, TAC, 1,2 polybutadiene, metal salts of unsaturated carboxylic acids, oximes, guanidine, trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, N-N'-m-phenylenebismaleimide, and sulfur It is used for crosslinking.

Of these, N, N'-m-phenylenedimaleimide is preferred, and the addition of N, N'-m-phenylenedimaleimide increases the degree of cross-linking and can prevent adhesive abrasion and the like. N,
The addition amount of N'-m-phenylenedimaleimide is 0.2 to 10 parts by weight with respect to 100 parts by weight of the ethylene-α-olefin elastomer. The effect of improving the abrasion resistance and the adhesive abrasion resistance is small. On the other hand, if it exceeds 10 parts by weight, the elongation of the vulcanized rubber is remarkably reduced, causing a problem in the bending resistance. Furthermore,
The compressed rubber layers 4 and 26 contain sulfur in an amount of 0.01 to 100 parts by weight based on the ethylene-α-olefin elastomer.
By adding 1 part by weight, a decrease in elongation of the vulcanized rubber can be controlled. If the amount exceeds 1 part by weight, the degree of crosslinking does not improve as expected, so that the non-wear resistance and adhesive wear resistance of the vulcanized rubber also do not improve.

As the above-mentioned organic peroxide, usually, rubber,
Diacyl peroxide used for crosslinking of resin,
Peroxyester, diallyl peroxide, di-t
-Butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, 2.5-dimethyl-2
.5-di (t-butylperoxy) -hexane-3,1
• 3-bis (t-butylperoxy-isopropyl) benzene, 1,1-di-butylperoxy-3,3,5-
Trimethylcyclohexane and the like, and those having a one-minute half-life by thermal decomposition of 150 to 250 ° C. are preferable.

The addition amount is about 1 to 8 parts by weight, preferably 1.5 to 4 parts by weight, based on 100 parts by weight of the ethylene-α-olefin elastomer.

Short fibers made of nylon 6, nylon 66, polyester, cotton, and aramid are mixed in the compressed rubber layers 4 and 26 to improve the lateral pressure resistance of the compressed rubber layer 4 and to make contact with the pulley. The surface of the compressed rubber layer 4 is polished by a grinder to project the short fibers. The coefficient of friction of the surface of the compressed rubber layer 4 is reduced, and noise during belt running is reduced. Of these short fibers,
Aramid short fibers, which are rigid and strong and have abrasion resistance, are most effective.

In order for the aramid short fibers to sufficiently exhibit the above-mentioned effects, the fiber length of the aramid fibers should be 1 to 20.
mm, the amount is 1 to 30 parts by weight based on 100 parts by weight of the ethylene-α-olefin elastomer. This aramid fiber has an aramid having an aromatic ring in the molecular structure,
For example, brand names Conex, Nonex, Kevlar,
Technora, Twaron, etc.

The compressed rubber layers 4 and 26 have an ethylene-α-olefin elastomer 1 as a matrix rubber.
With respect to 00 parts by weight, an ethylene-α-olefin elastomer and a fiber diameter of 1.0 μm or less, preferably 0.05 to
1 to 50 parts by weight, preferably 5 to 5 parts by weight of a micro-short fiber reinforced rubber graft-bonded with 0.8 μm micro-short fibers
25 parts by weight may be contained. If the blending amount of the short microfiber reinforced rubber is less than 1 part by weight, abrasion resistance is not sufficient, and if it exceeds 50 parts by weight, elongation of the rubber composition is reduced, and heat resistance and bending resistance are reduced.

In the micro-short fiber reinforced rubber, the ethylene-α-olefin elastomer constituting it is completely the same or similar to the ethylene-α-olefin elastomer of the matrix rubber of the compressed rubber layers 4 and 26. Good bonding with matrix rubber. For this reason, since the ethylene-α-olefin elastomer and the short microfiber are chemically bonded between the short microfiber reinforced rubber and the matrix rubber, or even in the short microfiber reinforced rubber, cracks are formed in the compressed rubber layers 4 and 26. Difficult to penetrate, even if cracks occur.

[0027] In the above short fiber reinforced rubber, the interface between the short fibers and the ethylene-α-olefin elastomer is a coupling agent such as vinyl tris (β-methoxyethoxy) silane, vinyl triethoxy silane, γ.
-Silane coupling agents such as methacryloxypropyltrimethoxysilane, titanate coupling agents including isopropyl triisostearoyl titanate,
Acrylic acid, methacrylic acid, unsaturated carboxylic acid such as maleic acid, or grafted via an adhesive such as novolak type phenol resin, ethylene-
It is obtained by kneading and extruding an adhesive such as an α-olefin elastomer, micro short fibers, and a coupling agent at a temperature at which the short fibers melt.

The short microfiber reinforced rubber has a rubber component as a continuous phase in which the short microfibers are dispersed in a fine form, and the short microfibers form a strong chemical bond or interaction with the rubber component at the interface. ing. For this reason, the rubber layer containing this hardly cracks, and even if the cracks do not easily propagate. Moreover, the belt using this also has excellent heat resistance, cold resistance, bending resistance, and abrasion resistance.

The compressed rubber layers 4 and 26 may further include a reinforcing agent such as carbon black and silica, clay,
Various agents such as a filler such as calcium carbonate, a softener, a processing aid, an antioxidant, and a co-crosslinking agent such as TAIC may be added.

The above-mentioned compressed rubber layers 4 and 26 are made of nitrile rubber, hydrogenated nitrile rubber, hydrogenated nitrile rubber to which an unsaturated carboxylic acid metal salt is added together with ethylene-α-olefin elastomer, chlorosulfonated polyethylene. , Chloroprene, urethane rubber, epichlorohydrin rubber, natural rubber, CSM, ACSM, SBR
Is used.

The hydrogenated nitrile rubber has a hydrogenation rate of 80% or more, and exhibits heat resistance and ozone resistance characteristics.
Preferably, 90% or more is good. A hydrogenated nitrile rubber having a hydrogenation rate of less than 80% has extremely low heat resistance and ozone resistance. In consideration of oil resistance and cold resistance, the amount of bound acrylonitrile is preferably in the range of 20 to 45%.

The chlorosulfonated polyethylene has a chlorine content of 15 to 35% by weight, preferably 25 to 32% by weight.
And a chlorosulfonated linear low-density polyethylene having a sulfur content in the range of 0.5 to 2.5% by weight.

For the adhesive rubber layers 3 and 24, the same ethylene-α-olefin elastomer composition as that for the compressed rubber layers 4 and 26 is used. However, in order to adhere well to the polyester fiber, aramid fiber, glass fiber, etc., which is the core wire, an ethylene-α-olefin elastomer composition by sulfur vulcanization containing no peroxide, a chlorosulfonated polyethylene composition or hydrogen Nitrile rubber compositions can also be used.

For the cords 2 and 23, ropes made of polyethylene terephthalate fiber, polyester fiber having ethylene-2,6-naphthalate as a main constituent unit, and polyamide fiber are used, and are bonded for the purpose of improving adhesion to rubber. Processing is performed. As such an adhesive treatment, it is common to immerse the fiber in resorcin-formalin-latex (RFL solution) and then heat and dry to form an adhesive layer uniformly on the surface. However, without being limited to this, after pretreatment with an epoxy or isocyanate compound, R
There is also a method of treating with an FL solution.

The ethylene-2,6-naphthalate used in the present invention is usually prepared by condensation polymerization of naphthalene-2,6-dicarboxylic acid or an ester-forming derivative thereof with ethylene glycol in the presence of a catalyst under appropriate conditions. To be synthesized. At this time, if one or more appropriate third components are added before the completion of the polymerization of ethylene-2,6-naphthalate, a copolymer polyester is synthesized.

First, the unbonded cord is impregnated into a tank containing a treatment liquid selected from an epoxy compound and an isocyanate compound and pre-dip, and then (2) 160 to 200 °. C through a drying oven set at a temperature of 30 to 600 seconds for drying.
(4) 21
30 to the stretching heat setting processor set at a temperature of 0 to 260 ° C.
Stretching is performed for １〜３1 to 3% for ６００600 seconds to obtain a stretched cord.

The RFL solution is prepared by mixing a latex with an initial condensate of resorcinol and formalin, and the latex used herein includes chloroprene, styrene / butadiene / vinylpyridine terpolymer, hydrogenated nitrile, NBR, etc. It is.

The cover canvases 5 and 22 are made of a cloth woven in a plain weave, a twill weave, a satin weave, or the like using a thread made of cotton, polyamide, polyethylene terephthalate, or aramid fiber.
Adhesion treatment is performed by FL treatment to prevent wrinkling of the tubular belt canvas in the spinning process. The RFL treatment is performed by immersing in the RFL solution for 0.1 to 20 seconds and then at 100 to 200 ° C. for 30 minutes.
After drying for about 600 seconds, a tubular canvas having at least one joint is formed by sewing with an overlock or the like. In some cases, a carbon black liquid is appropriately mixed with the RFL liquid to blacken the treated material. In the case of cotton fabric, a known surfactant is added to the RFL solution in an amount of 0.1 to 0.1%.
It is advisable to add 1.0% by weight.

An example of a method for manufacturing the V-ribbed belt 1 is as follows. First, on the peripheral surface of the cylindrical forming drum,
After winding a plurality of cover canvases and a cushion rubber layer, a cord made of a rope is spirally spun on this, and a compressed rubber layer is sequentially wound thereon to obtain a laminate,
This is vulcanized to obtain a vulcanized sleeve.

Next, the vulcanization sleeve is hung between a driving roll and a driven roll and travels under a predetermined tension, and the rotated grinding wheel is moved so as to abut the traveling vulcanization sleeve to perform vulcanization. 3 to 100 on the surface of the compression rubber layer of the sleeve
The plurality of groove portions are ground at one time.

The vulcanization sleeve obtained in this manner is removed from the driving roll and the driven roll, and the vulcanization sleeve is hung on another driving roll and the driven roll to travel, and cut into a predetermined width by a cutter. To make individual V-ribbed belts.

[0042]

The present invention will be described in more detail with reference to the following examples.

Example 1 and Comparative Example 1 In the V-ribbed belt manufactured in this example, a core wire made of a polyester fiber rope was embedded in an adhesive rubber layer, and an RFL solution (styrene-butadiene-vinylpyridine triethyl) was placed on the upper side thereof. 1 ply of cotton canvas treated only with 100 parts by weight of the original copolymer, 14.6 parts by weight of resorcinol, 9.2 parts by weight of formalin, 1.5 parts by weight of caustic soda, and 262.5 parts by weight of water A compressed rubber layer is provided below the rubber layer and has three ribs in the longitudinal direction of the belt. The obtained V-ribbed belt is a K-type 3-ribbed belt having a length of 975 mm according to the RMA standard and a rib pitch of 3.56 mm.
The rib height is 2.0 mm, the belt thickness is 4.3 mm, and the rib angle is 40 °.

Here, a compressed rubber layer was prepared from two types of rubber compositions, a short fiber mixed rubber layer and a fine particle dispersed rubber layer shown in Table 1, kneaded with a Banbury mixer, and then rolled with calender rolls. Was. The compressed rubber layer contains short fibers and is oriented in the belt width direction. Example 1
In the compressed rubber layer, one rubber layer mixed with short fibers having a length of 3 mm is provided in the rubber layer mixed with short fibers, while in Comparative Example 2, only the rubber layer mixed with short fibers is used.

[0045]

[Table 1]

The belt is manufactured in the usual manner. First, a cotton cylindrical cover canvas treated only with the RFL solution, which has been subjected to one ply sewing machine joint, is inserted into a smooth cylindrical mold, and then the adhesive rubber layer is wound thereon. After spinning the core wire and further arranging the compressed rubber layer, a crosslinking jacket is inserted on the compressed rubber layer. Next, the mold is placed in a vulcanizing can, and after crosslinking, the tubular cross-linked sleeve is removed from the mold, the compressed rubber layer of the sleeve is formed into ribs by a grinder, and the individual molded product is cut into individual belts. Has become.

The V-ribbed belt thus obtained was subjected to a water injection running test to measure the torque at the time of 2% slip and the roughness of the rib surface in the belt thickness direction. The results are shown in Table 2.

In the water injection running test, a drive pulley (120 mm diameter) was used.
mm), a driven pulley (120 mm in diameter), and a tension pulley (80 mm in diameter) in combination. A belt is hung on each pulley of the tester, and water is injected into the entrance side of the driving pulley at a water injection rate of 10 cc / sec. At room temperature, the number of rotations of the driving pulley is 2000 rpm, and the belt tension is 1
The vehicle was run for 200 hours on a 47N / 3 rib.

[0049]

[Table 2]

As is clear from these results, it is understood that high power transmission can be achieved even when water adheres to the transmission surface.

[0051]

As described above, according to the present invention,
The fine particle-dispersed rubber layer has a rough surface roughness in the belt thickness direction of the transmission surface, and can maintain high power even if water adheres to the transmission surface by maintaining it for a long time. By intervening locally in the rubber layer, the modulus in the belt width direction does not increase, the elongation in the belt longitudinal direction is maintained, and the bending resistance is not hindered. In addition, by using an ethylene-alpha-olefin elastomer for the compressed rubber layer, the running life of the belt in a high-temperature atmosphere and a low-temperature atmosphere is improved, and the weather resistance is also excellent.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a V-ribbed belt according to the present invention.

FIG. 2 is a vertical sectional view of a V-cut edge type V-belt according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 V-ribbed belt 2, 23 core wire 3, 24 Adhesive rubber layer 4, 26 Compressed rubber layer 5, 22 Cover canvas 7 Rib portion 8, 28 Fine particle dispersed rubber layer 9, 29 Short fiber mixed rubber layer 21 V belt

Claims (5)

[Claims] 1. A power transmission belt in which a cover canvas is laminated on the surface and a compression rubber layer is disposed adjacent to an adhesive rubber layer in which a core wire is embedded along the longitudinal direction of the belt. At least one in which material fine particles are dispersed
A power transmission belt, wherein the fine particle-dispersed rubber layer is interposed in a short fiber-mixed rubber layer in which short fibers are dispersed in rubber. 2. The power transmission belt according to claim 1, wherein the fine particles of the inorganic material in the fine particle dispersed rubber layer are ceramic powder. 3. The power transmission belt according to claim 1, wherein the inorganic material fine particles of the fine particle dispersed rubber layer are diatomaceous earth. 4. The power transmission belt according to claim 1, wherein the rubber of the compression rubber layer is a crosslinked product of an ethylene-α-olefin elastomer crosslinked with an organic peroxide. 5. The transmission belt according to claim 1, wherein the transmission belt is a V-ribbed belt comprising an adhesive rubber having a core buried along the longitudinal direction of the belt and a compression rubber layer having a plurality of rib portions extending in the circumferential direction of the belt. Transmission belt.