JP2000297847A - Transmitting belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve heat resistance and cold resistance, to improve durability of a belt at the time of a traveling under a high temperature atmosphere and a low temperature atmosphere and to prevent sound production due to adhesion also at the time of a back face driving. SOLUTION: In this transmitting belt, cover canvas 5 is laminated on a surface and a compressed rubber layer 4 is arranged adjacently to an adhesive rubber layer 3 in which a core wire 2 is buried along a belt longitudinal direction. In this case, the belt is constituted by using a vulcanized material of a sulfur-crosslinking rubber composition using ethylene-α-olefin elastomer as the adhesive rubber layer 3, a crosslinking material of an organic peroxide crosslinking rubber composition using ethylene-α-olefin elastomer as the compressed rubber layer 4 and resorcinol-formalin-latex processed canvas as the cover canvas 5.

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, and more particularly to a power transmission belt including a friction transmission type such as a V-ribbed belt, a cut-edge type V belt, and the like under a high-temperature atmosphere and a low-temperature atmosphere. The present invention relates to a power transmission belt which has improved belt running life, excellent weather resistance, and further prevents sound due to sticking during rear driving.

[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. As a result, the operating temperature of the power transmission belt has been increasing. Conventionally, natural rubber, styrene-butadiene rubber, and chloroprene rubber have been mainly used for power transmission belts. However, in a high-temperature atmosphere, a problem has occurred in that a crack is generated in a cured compressed rubber layer at an early stage.

[0003] In response to such an early breakage phenomenon of the belt,
Improvements in the heat resistance of chloroprene rubber have been studied, and although some improvements have been made, there is a limit as long as chloroprene rubber is used, and no sufficient effect has been obtained at present.

[0004] For this reason, the use of rubbers having a highly saturated or completely saturated main chain, such as chlorosulfonated polyethylene rubber, hydrogenated nitrile rubber, and fluoro rubber, which are excellent in heat resistance, has been studied. . Of these, chlorosulfonated polyethylene is generally equivalent to chloroprene rubber in terms of dynamic fatigue, abrasion resistance, and oil resistance, but is known to have a large effect on vulcanization, especially the acid acceptor, in water resistance. ing. Usually, oxides such as MgO and PbO have been used as acid acceptors for chlorosulfonated polyethylene.

However, PbO, Pb_ThreeO_FourEtc. of lead compounds
If an acid acceptor is used, a belt with good water resistance can be obtained.
However, use of lead compounds is preferred due to pollution and hygiene issues.
Absent. When MgO is used as an acid acceptor,
MgCl generated during the bridge reaction _TwoSignificantly impairs water resistance
In short, adaptation to the belt was inappropriate. Meanwhile, metal
Use epoxy acid acceptors as acid acceptors other than oxides
If it is, it is possible to obtain a composition having good water resistance
However, there is a problem that odor is generated and the human body is uncomfortable.

[0006]

However, this power transmission belt has a significantly improved belt running life in a high-temperature atmosphere as compared with a belt using chloroprene rubber, and has excellent heat resistance. It became clear that the running life of the belt in a low temperature atmosphere of -30 ° C or less was significantly 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-alpha-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. V
In the case of dry friction transmission such as a ribbed belt, slippage occurs when a large amount of oil is applied, and the transmission function is impaired. Thus, it has not been used much in the past, but recently disclosed in, for example, JP-A-6-345948. like,
It is being considered.

However, the ethylene-propylene rubber has a low tearing power, and the use of a peroxide cross-linking system further lowers the tearing power, so that there is a problem that the cord tends to pop out during running. On the other hand, in the case of using a sulfur cross-linking system, it is difficult to sufficiently increase the degree of vulcanization, so that the abrasion increases during running. This was a major problem that caused pronunciation. In addition, when EPDM having an extremely large amount of double bonds in the molecule is used to increase the degree of vulcanization, adhesive wear can be improved to some extent, but heat resistance decreases.

[0009] Further, after the cover canvas is subjected to RFL treatment as is usually performed with a belt using chloroprene rubber, rubber is further adhered in order to improve moldability and adhesion to the adhesive rubber layer. However, when power is transmitted using the back surface of the belt, there is a problem that the rubber attached to the cover canvas easily sticks due to frictional wear between the pulley and the cover canvas.

The present invention addresses such a problem and improves the heat resistance and cold resistance to improve the durability of the belt when running in a high-temperature atmosphere and a low-temperature atmosphere. Another object of the present invention is to provide a power transmission belt in which sound generation due to adhesion is prevented.

[0011]

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 placed power transmission belt, the sulfur-crosslinked vulcanized ethylene-alpha-olefin elastomer is used as the adhesive rubber layer, and the ethylene-alpha-olefin elastomer crosslinked with an organic peroxide is used as the compression rubber layer. Further, a transmission belt using a resorcin-formalin-latex-treated canvas as a cover canvas.

According to a second aspect of the present invention, the transmission belt according to the first aspect has an adhesive rubber having a core buried along a longitudinal direction of the belt and a compressed rubber layer having a plurality of rib portions extending in a circumferential direction of the belt. Is a V-ribbed belt.

According to the invention of claim 3 of the present application, in a power transmission belt composed of an adhesive rubber layer having a core wire buried along the belt longitudinal direction and an elastic layer including a compression rubber layer, at least the compression rubber layer has A rubber layer obtained by adding 0.2 to 10 parts by weight of N, N'-m-phenylenedimaleimide to 100 parts by weight of an α-olefin elastomer, using a peroxide-cured rubber layer, and further using resorcinol-formalin as a cover canvas In a transmission belt using latex-treated canvas.

According to the invention of claim 4 of the present application, there is provided a power transmission belt in which 0.01 to 1.0 part by weight of sulfur is added to 100 parts by weight of an ethylene-α-olefin elastomer in a compressed rubber layer.

According to a fifth aspect of the present invention, there is provided a power transmission belt using a sulfur-crosslinked vulcanized ethylene-alpha-olefin elastomer for the adhesive rubber layer.

According to a sixth aspect of the present invention, in the transmission belt according to the third aspect, an adhesive rubber having a core buried in a longitudinal direction of the belt and a compressed rubber layer having a plurality of rib portions extending in a circumferential direction of the belt. Is a V-ribbed belt.

[0017]

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.

The ethylene-α-olefin elastomer used for the compressed rubber layers 4 and 26 is a rubber composed of ethylene-propylene rubber (EPR) or ethylene-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 preferable, and the addition of N, N'-m-phenylenedimaleimide can increase the degree of crosslinking and 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 into 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 fiber to sufficiently exhibit the above-mentioned effects, the fiber length of the aramid fiber 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.

The fine short fiber reinforced rubber is composed of an ethylene-α-olefin elastomer which is completely the same as 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.

In the above micro-short fiber reinforced rubber, the interface between the micro-short fibers and the ethylene-α-olefin elastomer is a coupling agent such as vinyltris (β-methoxyethoxy) silane, vinyltriethoxysilane, 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 or 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 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.

Hydrogenated nitrile rubber has a hydrogenation rate of 80% or more, and exhibits heat resistance and ozone resistance.
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 the 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.

The bonding process of the above-mentioned core wire is carried out by (1) impregnating the untreated cord into a tank containing a treatment liquid selected from an epoxy compound and an isocyanate compound and pre-dipping it; 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 obtained by mixing a latex with an initial condensate of resorcinol and formalin, and the latex used here includes chloroprene, styrene / butadiene / vinylpyridine terpolymer, hydrogenated nitrile, NBR, etc. It is.

As shown in FIGS. 3 and 4, the cover canvases 5 and 22 are prepared by woven plain, twill, satin or the like using yarns made of cotton, polyamide, polyethylene terephthalate, and aramid fibers. Then, the cloth is RFL
In the spinning process, the wrinkles of the tubular belt canvas are prevented from being formed by an adhesive treatment. The RFL treatment is performed by dipping in the RFL solution for 0.1 to 20 seconds,
Dry at 0 ° C. for 30-600 seconds.

The RFL solution used here is a mixture of an initial condensate of resorcinol and formalin and a rubber latex. In this case, the molar ratio of resorcinol to formalin should be 1: 0.5 to 3 and the adhesive strength It is suitable for increasing the value. The initial condensate of resorcinol and formalin is
This is mixed with the latex so that the resin content is 10 to 100 parts by weight with respect to 100 parts by weight of the rubber content of the latex, and the total solid content is adjusted to a concentration of 5 to 40%.

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 1.0.
% By weight.

The latex is styrene-butadiene-
Vinylpyridine terpolymer, chlorosulfonated polyethylene, hydrogenated nitrile rubber, epichlorohydrin,
Latex such as natural rubber, SBR, chloroprene rubber, and olefin-vinyl ester copolymer.

Subsequently, as shown in FIG. 5, the width ends of the canvas 10 are abutted irrespective of the front and the back, and along the longitudinal direction (a), for example, a monofilament or a multifilament such as cotton yarn, nylon, vinylon, or polyester is applied. A tubular canvas 14 having one joint portion 13 is formed by sewing using overlock or the like.

As shown in FIGS. 6 and 7, the tubular canvas 14 is cut spirally at 45 ° with respect to the longitudinal direction (a) as shown by a cutting line 15 so that the warp yarns 12a and the weft yarns 12b are elongated. A continuous open canvas 17 arranged at an equal angle to the direction (a) is produced and wound around a reel 16.
The open cloth 17 maintains the crossing angle between the warp yarns 12a and the weft yarns 12b at 90 °, but each of the yarns 12a and 12b extends in the 45 ° direction with respect to the longitudinal direction (A), and the joint 1
3 are also arranged at predetermined intervals in the 45 ° direction.

FIG. 8 shows a process of producing a tubular belt canvas 18 from the open canvas 17 in which the warp 12a and the weft 12b intersect at an angle of 90 °. The open canvas 17 is cut to a predetermined length. Thereafter, the cut ends are joined to form a tubular belt canvas 18 having joint portions 19 and 13 of one right-angle joint line and a bias joint line.

FIG. 9 shows a warp 12a positioned parallel to the longitudinal direction (a) and a crossing angle of 120 ° with respect thereto.
The wide and angled canvas 10 is composed of weft yarns 12b arranged in such a manner. This wide-angle canvas 10 is a warp 1
It is obtained by performing a tenter process for forcibly increasing the crossing angle between 2a and the weft 12b. Even when the canvas 10 is used, the wide-angle canvas 10 is butt-stitched together with a sewing machine to form an elongated tubular canvas 40 as shown in FIGS. On the other hand, after the spiral cloth is cut in the direction of 60 ° to form the open canvas 17 in which the warp 12a and the weft 12b are arranged at an equal angle to the longitudinal axis, the open canvas 17 is cut into a predetermined length. The canvas can be cut and the cut ends of the canvas can be joined to form the cover canvas 18.

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 further, the rotated grinding wheel is moved so as to come into contact with 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 drive roll and the driven roll, and the vulcanization sleeve is hung on another drive roll and the driven roll to travel and cut into a predetermined width by a cutter. To make individual V-ribbed belts.

[0050]

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

Examples 1 to 3 and Comparative Examples 1 to 3 In the V-ribbed belts manufactured in this example, a core made of a polyester fiber rope was embedded in an adhesive rubber layer, and an RFL solution (styrene-butadiene) 1 ply of cotton canvas treated only with 100 parts by weight of vinylpyridine terpolymer, 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 On the other hand, a compression rubber layer is provided below the adhesive rubber layer, and has three ribs in the belt longitudinal direction. 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 2.9 mm, the belt thickness is 5.3 mm, and the rib angle is 40 °.

Here, the compressed rubber layer and the adhesive rubber layer were prepared from the rubber compositions shown in Table 1, respectively, kneaded with a Banbury mixer, and then rolled with calender rolls. The compressed rubber layer contains short fibers and is oriented in the belt width direction.

In the cover canvas treatment of Comparative Example 3, the cover canvas in which the above-mentioned RFL solution was applied was immersed in rubber paste obtained by diluting the C1 compounded rubber with 10% with toluene, and then sufficiently squeezed.
It was dried in an oven at ℃. The rubber adhesion amount was 30 g / m ² .

[0054]

[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 peeling test of adhesive rubber and core wire, heat-resistant running test, and evaluation of the presence or absence of adhesive wear of the rib portion and the presence or absence of back surface adhesion by running test at room temperature. Was. The results are shown in Tables 2 and 3.
Is shown in

First, in the peeling test, two core wires of the above-mentioned V-ribbed belt were peeled off at a speed of 50 mm / min at an ambient temperature of 23 ° C. and 120 ° C. using a strograph T.

The traveling tester used for the evaluation of the heat resistant traveling test includes a driving pulley (120 mm in diameter), a driven pulley (120 mm in diameter), and an idler pulley (70 m in diameter).
m) and a tension pulley (diameter: 45 mm). A belt is hung on each pulley of the testing machine, the ambient temperature is 120 ° C., and the number of rotations of the driving pulley is 49.
The driven pulley was driven at 12 horsepower at 00 rpm, and the tension pulley was run with an initial tension of 57 kgf.

The idler pulley is engaged on the back surface of the V-ribbed belt 1, and its winding angle is about 90 degrees. By this running test method, the time until cracks occurred in the rib portions of the belt was measured, and the heat resistance performance was compared.

In the evaluation of the presence or absence of adhesive wear of the rib portion by a running test at room temperature, a driving pulley (120 mm in diameter), a driven pulley (120 mm in diameter), and a tension pulley (45 mm in diameter) were combined as a running tester. Using the arrangement, the driven pulley was applied with a load of 12 hp, the driving pulley was rotated at 4900 rpm, and the tension pulley was run with an initial tension of 85 kgf.

In the evaluation of the presence or absence of the back surface adhesion, as a running test, a driving pulley (diameter 70 mm) and a driven pulley (diameter 120 mm) were used.
mm), a load of 11.2 hp is applied to the driven pulley, and a dead weight of 12 mm is applied.
The tension was applied by applying 0 kgf, and the drive pulley was rotated at a rotational speed of 700 to 2000 rpm in about 15 ± 5 seconds to run. Both the driving and driven pulleys used here had crowns in the surface shape, and were mounted so that the back surface of the belt was in contact with the pulley.

[0062]

[Table 2]

[0063]

[Table 3]

As is clear from the results of Tables 2 and 3, the rubber composition of an organic peroxide-crosslinkable ethylene-propylene rubber was used for the rib portion, and the sulfur-crosslinkable ethylene-propylene rubber was used for the adhesive rubber layer. The rubber composition of the present invention provides a belt of the present invention, which has an increased adhesive force between the core wire and the adhesive rubber layer as compared with a conventional belt, has a longer belt life under a high-temperature atmosphere, and further has an adhesive wear and a back surface adhesive at a rib portion. It turns out that it is hard to generate.

Examples 4 to 7, Comparative Examples 4 to 10 In the same manner as in Examples 1 to 3, a core wire made of a polyester fiber rope was embedded in an adhesive rubber layer, and an RFL solution (styrene) was -Butadiene-vinylpyridine terpolymer 100 parts by weight, resorcin 14.6 parts by weight, formalin 9.2 parts by weight, caustic soda 1.5 parts by weight, water 2
62.5 parts by weight), and a V-ribbed belt having a compression rubber layer below the adhesive rubber layer and having three ribs in the belt longitudinal direction was prepared. The obtained V-ribbed belt is a K-type 3-ribbed belt having a length of 975 mm according to the RMA standard, a rib pitch of 3.56 mm, a rib height of 2.9 mm, and a belt thickness of 5.3.
mm, and the rib angle is 40 °.

In Comparative Example 10, a cord made of a polyester fiber rope was buried in the adhesive rubber layer, treated with the above RFL solution, and then mixed with the adhesive rubber shown in Table 5 with toluene. The cotton canvas, which was immersed in a solution diluted to a concentration of 10% and dried sufficiently in an oven at 80 ° C., was adjusted to have a rubber adhesion of 30% by weight.
A ply was used. The same compressed rubber layer as in Example 4 was used.

Here, a compressed rubber layer was prepared from the rubber composition shown in Table 4, kneaded with a Banbury mixer, and then rolled with a calender roll. The compressed rubber layer contains short fibers and is oriented in the belt width direction.

The rubber composition shown in Table 5 was used as the adhesive rubber layer.

[0069]

[Table 4]

[0070]

[Table 5]

The V-ribbed belt thus obtained was subjected to the adhesive wear test on the rib portion and the back surface by the above-mentioned method, and further, the heat-resistant running test and the cold-resistant running test were performed by the following methods.
The results are shown in Table 4.

The traveling tester used for the evaluation of the heat-resistant traveling test includes a driving pulley (120 mm in diameter), a driven pulley (120 mm in diameter), and an idler pulley (45 m in diameter).
m) and a tension pulley (70 mm in diameter). A belt is hung on each pulley of the testing machine, the ambient temperature is 120 ° C., and the number of rotations of the driving pulley is 49.
The driven pulley was driven at 12 horsepower at 00 rpm, and the tension pulley was run with an initial tension of 57 kgf. The idler pulley engages on the back of the V-ribbed belt, and its wrap angle is about 120 degrees. By this running test method, the time until cracks occurred in the rib portions of the belt was measured, and the heat resistance performance was compared.

Further, the evaluation method of the cold-tolerant running test includes a driving pulley (140 mm in diameter) and a driven pulley (45 mm in diameter).
And a back idler pulley (diameter 75 mm) with a belt, apply a load of 85 kgf to the driven pulley, and apply -40 ° C
After being left for 18 hours at 700 rpm under the atmosphere described above, it was allowed to run for 1 minute, then stopped for 2 minutes, and this was repeated to measure the time until the belt was cracked.

As is clear from the results of the running test shown in Table 4, the belt of this embodiment using the rubber composition of ethylene-propylene rubber as the rib portion and the cover canvas treated only by the RFL treatment on the back surface of the belt was There is no sticking and abrasion of the ribs and the cover canvas compared to conventional belts, and the belt life in high-temperature and low-temperature atmospheres is improved compared to belts using chloroprene rubber, and excellent heat resistance and cold resistance It turns out that it has sex.

Comparative Example 11 A compressed rubber layer was prepared using the CR rubber compound shown in Table 6,
After kneading with a Banbury mixer, what was rolled with a calendar roll was used. The compressed rubber layer contains short fibers and is oriented in the belt width direction. As the adhesive rubber layer, a rubber compounding excluding the nylon cut yarn and the aramid cut yarn in the compounding of the compressed rubber layer was used.

As the cover canvas, a cotton canvas was prepared by using an RFL solution (styrene-butadiene-vinylpyridine terpolymer 100 parts by weight, resorcinol 14.6 parts by weight, formalin 9.2 parts by weight, caustic soda 1.5 parts by weight, Water 262.5
Parts by weight) and then immersed in a 10% dilution of the CR rubber compound shown in Table 3 in toluene, and dried sufficiently in an oven at 80 ° C. so that the rubber adhesion amount becomes 30% by weight. The prepared one was used.

Using the above materials, V
A ribbed belt was prepared, and an adhesive wear test, a heat resistance test and a cold resistance test of the rib portion and the back surface of the belt were performed.
Table 6 shows the results.

[0078]

[Table 6]

As a result, it can be seen that the belt using the CR rubber compound has no adhesive wear, but is inferior in heat resistance and cold resistance as compared with the examples.

[0080]

As described above, according to the present invention,
Vulcanizate of sulfur crosslinkable rubber composition using ethylene-alpha-olefin elastomer as adhesive rubber layer, and organic peroxide crosslinkable rubber composition using ethylene-alpha-olefin elastomer as compression rubber layer The resorcinol was used as a cover canvas.
Formalin-a power transmission belt using latex-treated canvas, which increases the adhesive force between the core wire and the adhesive rubber layer,
In addition, the belt life in a high-temperature atmosphere is improved, and adhesive abrasion hardly occurs. Further, since rubber is not adhered to the surface of the cover canvas, there is an effect that sound generation due to the adhesive can be prevented even in the case of rear driving.

Further, at least the compressed rubber layer contains 0.2 to 10 parts by weight of N, N'-m-phenylenedimaleimide per 100 parts by weight of the ethylene-α-olefin elastomer.
In a power transmission belt using a rubber layer which is added by weight and peroxide-vulcanized, and further a resorcin-formalin-latex-treated canvas is used as a cover canvas, the transmission rubber belt has excellent heat resistance, cold resistance and a compressed rubber portion. This has the effect of improving the abrasion resistance of the cover canvas and improving the durability of the belt.

[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.

FIG. 3 is a plan view of a plain-woven canvas before an adhesive treatment used in the present invention.

FIG. 4 is a cross-sectional view of the plain-woven canvas after the plain-woven canvas of FIG. 3 has been subjected to RFL treatment.

FIG. 5 shows a method of manufacturing a canvas for a power transmission belt according to the present invention.
It is a figure which shows the process which was the process and produced the cylindrical canvas by butt-joining the width edge of the plain-woven canvas.

FIG. 6 is a diagram showing a tubular canvas cut spirally in the longitudinal direction.

FIG. 7 is a view showing a state in which the open canvas is being finished.

FIG. 8 is a perspective view of a transmission belt canvas obtained by cutting the open canvas into a predetermined length and joining the ends of the canvas.

FIG. 9 is a plan view of a wide-angle canvas in which a crossing angle between a warp and a weft is 120 °.

[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 21 V belt

Claims (6)

[Claims] 1. A power transmission belt in which a cover canvas is laminated on the surface and a compression rubber layer is arranged adjacent to an adhesive rubber layer having a core wire buried along the longitudinal direction of the belt. The cured vulcanizate of the ethylene-alpha-olefin elastomer, the crosslinked product of the ethylene-alpha-olefin elastomer crosslinked with an organic peroxide as a compression rubber layer, and the resorcinol-formalin-latex-treated canvas as a cover canvas A power transmission belt characterized by using: 2. The transmission according to claim 1, wherein the transmission belt is a V-ribbed belt comprising an adhesive rubber having a core buried in a longitudinal direction of the belt and a compression rubber layer having a plurality of rib portions extending in a circumferential direction of the belt. belt. 3. A transmission belt comprising an adhesive rubber layer having a core buried along the belt longitudinal direction and an elastic layer including a compression rubber layer, wherein at least the compression rubber layer has ethylene-
N, 100 parts by weight of α-olefin elastomer
A rubber layer obtained by adding 0.2 to 10 parts by weight of N'-m-phenylenedimaleimide, using a peroxide-vulcanized rubber layer, and using a resorcinol-formalin-latex-treated canvas as a cover canvas. And transmission belt. 4. The compressed rubber layer contains 0.01 parts by weight of sulfur based on 100 parts by weight of an ethylene-α-olefin elastomer.
The power transmission belt according to claim 3, wherein the transmission belt is added in an amount of 1.0 to 1.0 parts by weight. 5. The power transmission belt according to claim 3, wherein a vulcanized product of an ethylene-alpha-olefin elastomer cross-linked with sulfur is used for the adhesive rubber layer. 6. The transmission belt according to claim 3, wherein the transmission belt is a V-ribbed belt comprising 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 a circumferential direction of the belt. Or the transmission belt according to 5.