JP2009019760A - Power transmission belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission belt in which an ethylene-α-olefin rubber composition adheres to a fiber cord. <P>SOLUTION: In this power transmission belt, a core wire 2 is buried in an adhesive rubber layer 3 along a belt longitudinal direction, a compressed rubber layer 4 is arranged on the side of a transmission surface adjacently to the adhesive rubber layer, and an expansion rubber layer is arranged on the side of a back surface. The adhesive layer consists of the ethylene-α-olefin rubber composition. The fiber cord forming the core wire is treated with a first treatment liquid consisting of an isocyanate composition or an epoxy composition. Next, the fiber cord is treated with a second treatment liquid consisting of a resorcinol-formalin-rubber latex in which a latex contains at least styrene and vinyl pyridine and the content of the styrene is 30-60 parts by mass to 100 parts by mass of the latex. Further, the fiber cord is treated with a third treatment liquid with a vulcanizing agent added to the ethylene-α-olefin rubber composition. After that, the fiber cord is subjected to contact-vulcanization with and adheres to an unvulcanized composition of ethylene-α-olefin rubber. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power transmission belt used for power transmission of a drive device or the like.

  In recent years, the ambient temperature around the engine room has risen compared to the conventional environment due to social demands for energy saving and downsizing of automobiles. Along with this, the operating environment temperature of the transmission belt has also increased. Conventionally, natural rubber, styrene-butadiene rubber, and chloroprene rubber have been mainly used as the rubber for the transmission belt, but there has been a problem that cracks occur early in the cured compressed rubber layer under a high temperature atmosphere.

In order to cope with such an early failure phenomenon of the transmission belt, improvement of the heat resistance of the chloroprene rubber has been studied conventionally, but recently, for example, as disclosed in Patent Document 1, it has been improved. The use of ethylene-α-olefin elastomers such as ethylene-propylene rubber (EPR) or ethylene-propylene-diene rubber (EPDM), which are relatively inexpensive polymers having heat resistance and cold resistance, is also being studied. is there.
JP-A-6-345948

  However, ethylene-propylene rubber has a low tear resistance, and when a peroxide vulcanization system is used, there is a problem in that the tear resistance is further lowered and the core wire is easily ejected during running. On the other hand, it is difficult to sufficiently increase the degree of vulcanization in the case of using a sulfur vulcanizing system, and thus wear increases during traveling. Particularly in the case of a V-ribbed belt, the abrasion powder accumulates at the bottom between the rib portions and adheres. It was prone to wear, and this was a big 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, although the adhesive wear can be improved to some extent, there is a problem that the heat resistance is lowered.

  Furthermore, in addition to the problem of the rubber composition alone, there is a problem of the method for bonding the ethylene-α-olefin elastomer and the fiber cord serving as the core wire. Specific measures include a method in which the fiber cord is dipped in a dip solution containing resorcin-formalin-NBR latex and then vulcanized and bonded to the EPDM rubber composition, or an adhesion treatment with a resorcin-formalin-rubber latex adhesive solution. A method of vulcanizing and adhering an EPDM rubber composition blended with the above-described fiber cord and a methylene donor, a methylene acceptor and a silicic acid compound has been studied.

  In addition, ethylene / α-olefin rubber has low reactivity in the adhesion between canvas and ethylene / α-olefin rubber, and when treated with resorcin / formalin / rubber latex using latex with low polarity on the canvas, it is vulcanized. Occasionally, an amine compound and radical generated from a vulcanization accelerator or an anti-aging agent blended in the rubber caused the interface peeling of the canvas-adhesion treatment layer, resulting in a decrease in adhesion.

  However, in the method using a dip solution containing resorcin-formalin-NBR latex, there is a problem that even if the adhesive force is improved, it is lowered early due to repeated bending fatigue. Further, even when an EPDM rubber composition blended with a methylene donor, a methylene acceptor and a silicate compound is used, there is a problem that the core wire or the canvas and the adhesive rubber layer peel off at an early stage.

  The present invention pays attention to these problems, and an ethylene / α-olefin rubber composition capable of satisfactorily bonding an ethylene / α-olefin rubber composition and a fiber cord or canvas serving as a core of a transmission belt; It is an object of the present invention to provide a power transmission belt which is subjected to an adhesive formulation with a fiber cord or canvas.

  In the invention according to claim 1, the core wire is embedded in the adhesive rubber layer along the longitudinal direction of the belt, the compression rubber layer is disposed on the transmission surface side adjacent to the adhesive rubber layer, and the back surface is expanded. In a power transmission belt having a rubber layer disposed thereon, the adhesive rubber layer is an ethylene / α-olefin rubber composition, and the fiber cord forming the core wire is treated with a first treatment liquid comprising an isocyanate compound or an epoxy compound. Next, the second latex of the resorcin-formalin-rubber latex in which the latex is a latex containing at least styrene and vinylpyridine, and the styrene content is 30 to 60 parts by mass with respect to 100 parts by mass of the latex. After treatment with a treatment liquid, and further treatment with a third treatment liquid in which a vulcanizing agent is added to the ethylene / α-olefin rubber composition, ethylene / α-olefin is obtained. In power transmission belts obtained by bonding the unvulcanized composition and the adhesion vulcanization brought ethylene · alpha-olefin rubber composition and fiber cord Ngomu.

  The invention according to claim 2 is a 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. The adhesive rubber layer or the compressed rubber layer is an ethylene / α-olefin rubber composition, and the cover canvas is a latex containing at least styrene and vinylpyridine, and the styrene content is 100 parts by mass of the latex. The power transmission belt has a resorcin-formalin-rubber latex treatment solution contained in an amount of 30 to 60 parts by mass, and then an ethylene / α-olefin rubber composition and a cover canvas bonded to each other.

  According to a third aspect of the present invention, there is provided a power transmission belt in which a cover canvas is laminated on a surface, and a compression rubber layer is disposed adjacent to an adhesive rubber layer in which a core wire is embedded along a longitudinal direction of the belt. , An ethylene / α-olefin rubber composition, wherein the fiber cord forming the core is treated with a first treatment liquid comprising an isocyanate compound or an epoxy compound, and then the latex comprises at least styrene and vinylpyridine The styrene content is 30 to 60 parts by mass with respect to 100 parts by mass of the latex, and then treated with a second treatment solution of resorcin-formalin-rubber latex, and then ethylene / α-olefin rubber. After treatment with a third treatment liquid in which a vulcanizing agent is added to the composition, it is closely vulcanized with an unvulcanized composition of ethylene / α-olefin rubber. The ethylene / α-olefin rubber composition and the fiber cord are bonded, and at least the adhesive rubber layer or the compressed rubber layer contacting the cover canvas is an ethylene / α-olefin rubber composition, and latex is applied to the cover canvas. After treatment with a treatment solution of resorcin-formalin-rubber latex containing at least 30 to 60 parts by mass of the styrene with respect to 100 parts by mass of the latex, the latex containing at least styrene and vinylpyridine, A power transmission belt in which an α-olefin rubber composition and a cover canvas are bonded.

The invention according to claim 4 is the power according to any one of claims 1 to 3, wherein the breaking strength in the film state of the rubber latex used for the resorcin-formalin-rubber latex is 5 to 60 kgf / cm ^2. Located on the transmission belt.

  According to the first aspect of the present invention, the core wire is embedded in the adhesive rubber layer along the longitudinal direction of the belt, the compression rubber layer is disposed on the transmission surface side adjacent to the adhesive rubber layer, and on the back surface side. In the power transmission belt provided with the stretch rubber layer, the adhesive rubber layer is an ethylene / α-olefin rubber composition, and the fiber cord forming the core wire is a first treatment liquid made of an isocyanate compound or an epoxy compound. Treatment, and then the latex is a latex containing at least styrene and vinyl pyridine, and the content of the styrene is 30-60 parts by mass with respect to 100 parts by mass of the latex. After the treatment with the second treatment liquid, and further with the third treatment liquid in which the vulcanizing agent is added to the ethylene / α-olefin rubber composition, the ethylene / α-olefin is treated. Because it is a power transmission belt in which an unvulcanized composition of rubber, an adhesively vulcanized ethylene / α-olefin rubber composition, and a fiber cord are bonded together, the breaking strength of the latex film of resorcin-formalin-rubber latex is increased. And adhesion with EPDM is improved.

  According to the second aspect of the present invention, at least the adhesive rubber layer or the compressed rubber layer in contact with the cover canvas is an ethylene / α-olefin rubber composition, and the latex includes at least styrene and vinylpyridine in the cover canvas. After processing with a processing solution of resorcin-formalin-rubber latex containing 30-60 parts by mass of styrene with respect to 100 parts by mass of latex, an ethylene / α-olefin rubber composition and Since the power transmission belt is bonded to the cover canvas, the breaking strength of the latex film of resorcin-formalin-rubber latex can be increased, and the adhesiveness between EPDM and the canvas is improved.

  According to the invention described in claim 3, the adhesive rubber layer is an ethylene / α-olefin rubber composition, and the fiber cord forming the core wire is treated with a first treatment liquid comprising an isocyanate compound or an epoxy compound. Next, the second latex of the resorcin-formalin-rubber latex in which the latex is a latex containing at least styrene and vinylpyridine, and the styrene content is 30 to 60 parts by mass with respect to 100 parts by mass of the latex. After treatment with a treatment liquid and further treatment with a third treatment liquid in which a vulcanizing agent is added to the ethylene / α-olefin rubber composition, adhesion vulcanization with the unvulcanized composition of ethylene / α-olefin rubber is performed. Adhesive rubber layer or compression that adheres ethylene / α-olefin rubber composition and fiber cord, and at least comes into contact with cover canvas The rubber layer is an ethylene / α-olefin rubber composition, and the cover canvas is a latex containing at least styrene and vinylpyridine, and the content of the styrene is 30 to 60 parts by mass with respect to 100 parts by mass of the latex. The resorcin-formalin-rubber latex is a power transmission belt in which the ethylene / α-olefin rubber composition and the cover canvas are bonded after being treated with the resorcin-formalin-rubber latex treatment liquid contained in parts by mass. It is possible to increase the breaking strength of the latex film and to improve the adhesion between EPDM and the core wire and canvas.

According to invention of Claim 4, the breaking strength in the film state of the rubber latex used for the said resorcinol-formalin-rubber latex is 5-60 kgf / cm < ² >. Since it is a power transmission belt, it is possible to prevent amine compounds and radicals generated during vulcanization from permeating through the latex film, and there is an effect of improving the adhesion between EPDM and the core wire.

  A typical example of the ethylene / α-olefin rubber composition used in the present invention is a rubber made of ethylene-propylene-diene monomer (EPDM). Examples of the diene monomer include dicyclopentadiene, methylene norbornene, ethylidene norbornene, 1,4-hexadiene, and cyclooctadiene. Also, ethylene-propylene rubber (EPR) can be used.

  For rubber vulcanization, sulfur or organic peroxide is used. Examples of the organic peroxide include dicumyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, benzoyl peroxide, 1,3-bis (t-butylperoxyisopropyl) benzene, 2,5 -Dimethyl-2,5-di (t-butylperoxy) hexyne-3,2,5-dimethyl-2,5- (benzoylperoxy) hexane, 2,5-dimethyl-2,5-mono (t- Butyl peroxy) hexane and the like. This organic peroxide is usually used alone or as a mixture in the range of 0.005 to 0.02 mol g with respect to 100 g of the ethylene-α-olefin elastomer.

  Further, by adding a crosslinking aid, the degree of crosslinking can be increased to prevent problems such as adhesive wear. Examples of the crosslinking aid include TIAC, TAC, 1,2 polybutadiene, metal salt of unsaturated carboxylic acid, oximes, guanidine, trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, NN′-m- Usually used for peroxide vulcanization such as phenylene bismaleimide and sulfur. The cogged V-belt 3 in FIG. 2 that is a power transmission belt has a configuration in which a compression rubber layer 13 on the inner peripheral side, an extension rubber layer 15 on the outer peripheral side, and an adhesive rubber layer 18 are laminated between the rubber layers 13 and 15. A core wire 19 extending in the longitudinal direction of the belt is embedded in the adhesive rubber layer 18. Further, the compression rubber layer 13 and the stretch rubber layer 15 are formed with cog peaks 16 and cog valleys 14 extending in the belt width direction alternately along the belt longitudinal direction.

  In addition, other rubber compounds such as enhancers such as carbon black and silica, fillers such as calcium carbonate and talc, plasticizers, stabilizers, processing aids, and colorants are used as necessary. What is used is used.

The twisted yarn cord to be used is processed by the following method.
(1) First, an untreated twisted cord is immersed in a first treatment solution set at room temperature with an isocyanate compound or / and an epoxy resin for 0.5 to 30 seconds, and then placed in an oven adjusted to 150 to 190 ° C. in an amount of 2 to 5 Dry through for a minute.

  Examples of the isocyanate compound used in the first treatment liquid include 4,4′-diphenylmethane diisocyanate, tolylene 2,4-diisocyanate, polymethylene polyphenyl diisocyanate, hexamethylene diisocyanate, and polyaryl polyisocyanate (for example, PAPI is a trade name). There is). This isocyanate compound is also used by mixing with an organic solvent such as toluene or methyl ethyl ketone.

  In addition, blocked polyisocyanates in which the isocyanate group of the polyisocyanate is blocked by reacting the isocyanate compound with a blocking agent such as phenols, tertiary alcohols, and secondary alcohols can also be used.

  Examples of the epoxy compound used in the first treatment liquid include reaction products of polyhydric alcohols such as ethylene glycol, glycerin and pentaerythritol, polyalkylene glycols such as polyethylene glycol and halogen-containing epoxy compounds such as epichlorohydrin, , Resorcinol, bis (4-hydroxyphenyl) dimethylmethane, phenol-formaldehyde resin, reaction products with halogen-containing epoxy compounds such as resorcin-formaldehyde resin and the like. The epoxy compound is used by mixing with an organic solvent such as toluene or methyl ethyl ketone.

  Here, the adhesion rate of the isocyanate compound or the epoxy compound to the twisted cord is preferably 8% or less. If the adhesion rate exceeds 8%, the rigidity of the processing cord increases, and the core wire is likely to jump out due to the bending of the belt. The adhesion rate of the isocyanate compound or the epoxy compound to the twisted cord is calculated from the ratio of the mass of the cord before and after the treatment with the first treatment liquid.

  (2) Subsequently, it is processed with a second processing liquid that is an RFL liquid. The RFL liquid is obtained by mixing an initial condensate of resorcin and formalin with a rubber latex. In this case, it is preferable to increase the adhesive force by setting the molar ratio of resorcin and formalin to 3/1 to 1/3. Here, the rubber latex is preferably a latex containing at least styrene and vinylpyridine in order to improve the adhesive strength of the core wire to the ethylene / α-olefin rubber composition. The adhesive rubber layers 4 and 18 may further contain resorcin formalin resin or hexamethoxymethylmelamine resin. It is preferable that a compounding quantity is 1-10 mass parts, respectively with respect to 100 mass parts of rubber components. By blending resorcin formalin resin or hexamethoxymethylmelamine resin, the adhesiveness between the core wire and the belt body can be maintained at a high level even at high temperatures.

  The amount of styrene in the rubber latex of the RFL solution is preferably 30 to 60 parts by mass with respect to 100 parts by mass of the latex rubber. When the amount of styrene is less than 30 parts by mass, amine compounds and radicals generated from the vulcanization accelerator and anti-aging agent compounded in the rubber during belt vulcanization pass through the latex rubber film and adhere to the core wire. Interfacial peeling with the rubber layer occurs, and the adhesion between the core wire and the adhesive rubber is reduced.

  On the other hand, when the amount of the styrene is added in an amount exceeding 60 parts by mass in 100 parts by mass of the latex rubber, the latex rubber becomes hard due to styrene, the rope bending rigidity after the treatment is increased, and the bending fatigue resistance is increased. Get smaller.

  The initial condensate of resorcin and formalin is mixed so that the resin content is 5 to 100 parts by mass with respect to 100 parts by mass of the rubber content of the rubber latex, so that the total solid concentration becomes 5 to 40%. Adjusted to.

  The cord treated with the first treatment liquid is immersed in the RFL liquid for 0.5 to 30 seconds, and then heat treated by passing it through an oven adjusted to 200 to 250 ° C. for 1 to 3 minutes.

  (3) The third treatment liquid is obtained by dissolving an adhesive rubber composed of ethylene / α-olefin rubber and a vulcanizing agent in a solvent such as toluene, methyl ethyl ketone, and preferably ethylene / α- such as EPDM and EPT. Olefin rubber. The concentration of the third treatment liquid is preferably 10% by mass or less of the polymer component.

  Further, as vulcanizing agents, dibenzothiazyl disulfide (MBTS), tetramethylthiuram disulfide (TMTD), N-cyclohexyl-2-benzothiazylsulfenamide (CBS), tetramethylthiuram monosulfide (TMTM), mercapto Examples include benzothiazole (MBT), PZ (ZnMDC), and sulfur. This vulcanizing agent improves the adhesive force by heating and pressing the treated fiber cord and the ethylene / α-olefin rubber composition at 140 to 180 ° C.

  The twisted yarn cord subjected to the above-mentioned adhesion treatment is used as a core wire of the V-ribbed belt shown in FIG. 1 as a power transmission belt, for example. The V-ribbed belt 1 has a core wire 2 made of a high strength and low elongation twisted yarn cord embedded in an adhesive rubber layer 3 and has a compression rubber layer 4 below it. 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 rubberized canvas 5 attached to the belt surface.

  The rubber used for the compressed rubber layer 4 is 1 to 50 parts by mass, preferably 5 to 25 parts by mass of short fibers such as aramid, nylon, polyester, vinylon and cotton with respect to 100 parts by mass of the ethylene-α-olefin elastomer. Part may be contained.

  On the other hand, the rubber composition of the ethylene-α-olefin elastomer, which has heat resistance and good adhesion to the core, is used as the adhesive rubber layer 3 and can be vulcanized with sulfur. To do. Other than that, those used for normal rubber compounding such as carbon black and reinforcing agents such as silica, fillers such as calcium carbonate and talc, plasticizers, stabilizers, processing aids, and coloring agents are used. Is done.

  The addition amount of sulfur in the adhesive rubber layer 3 is 0.5 to 3.0 parts by mass with respect to 100 parts by mass of the ethylene-α-olefin elastomer.

  Of the ethylene-α-olefin elastomers used in the adhesive rubber layer 3, EPDM preferably has an iodine value of 4 or more and less than 40. When the iodine value is less than 4, the rubber composition is not sufficiently vulcanized with sulfur, and the problem of the core wire popping out occurs. On the other hand, if it exceeds 40, the scorch of the rubber composition becomes short and handling becomes difficult, and the heat resistance deteriorates.

  The canvas to be used is treated by the following method. It is treated with a treatment liquid which is an RFL liquid similar to the core wire. Also in the case of canvas, it is preferable that the molar ratio of resorcin to formalin is 3/1 to 1/3 in order to increase the adhesive strength, as in the case of the core wire treatment. Here, the rubber latex is preferably a latex containing at least styrene and vinylpyridine in order to improve the adhesive strength of the core wire to the ethylene / α-olefin rubber composition.

  The amount of styrene in the rubber latex of the RFL solution is preferably 30 to 60 parts by mass with respect to 100 parts by mass of the latex rubber. When the amount of styrene is less than 30 parts by mass, amine compounds and radicals generated from vulcanization accelerators and anti-aging agents blended in the rubber during belt vulcanization pass through the latex rubber film, and the canvas and adhesion-treated rubber Interfacial peeling with the layer occurs, and the adhesion between the canvas and the adhesive rubber decreases.

  On the other hand, when the amount of styrene exceeds 60 parts by mass in 100 parts by mass of latex rubber, the latex rubber becomes hard due to styrene, the canvas bending rigidity after treatment increases, and bending fatigue resistance increases. Get smaller.

The breaking strength of the rubber latex in the film state is preferably 5 to 60 kgf / cm ² . As a method for measuring the breaking strength, the latex was naturally dried to produce a film (film thickness of about 0.35 mm). This film was heat-treated in a 120 ° C. drying oven for 20 minutes. The heat-treated film is punched with a No. 3 dumbbell and left in a temperature-controlled room at 22 ° C. and 65% for one day. And a tensile test (autograph, model number AGS-10KND) is performed at a tensile speed of 500 mm / min in a thermostatic chamber. Here, when the breaking strength is less than 5 kgf / cm ² , interface peeling between the canvas and the adhesion-treated rubber layer occurs, and the adhesion between the canvas and the adhesion rubber is lowered.

On the other hand, when the breaking strength is greater than 60 kgf / cm ² , the latex rubber becomes too hard, the rope bending rigidity or the canvas bending rigidity after processing becomes too high, and the bending fatigue resistance becomes low.

  The initial condensate of resorcin and formalin is mixed so that the resin content is 5 to 100 parts by mass with respect to 100 parts by mass of the rubber content of the rubber latex, so that the total solid concentration becomes 5 to 40%. Adjusted to.

  The RFL treatment is immersed in the RFL solution for 0.1 to 30 seconds, followed by heat treatment by passing through an oven adjusted to 100 to 200 ° C. for 1 to 3 minutes.

  An example of the manufacturing method of the V-ribbed belt is as follows. First, after winding one or more cover canvases and a rubber sheet forming an adhesive rubber layer around the circumferential surface of a cylindrical molding drum, a cord made of a rope is spirally wound on this, and further compressed rubber After the layers are wound to obtain a laminate, this is vulcanized with a vulcanizing can to obtain a vulcanized sleeve.

  Next, the vulcanization sleeve is hung on a drive roll and a driven roll, and is run under a predetermined tension. The rotated grinding wheel is brought into contact with the running vulcanization sleeve, and the compressed rubber layer surface of the vulcanization sleeve 3 to 100 grooves are formed at a time.

  The obtained vulcanization sleeve is removed from the drive roll and the driven roll, the vulcanization sleeve is hung on another drive roll and the follower roll, traveled, cut into a predetermined width by a cutter, and finished into individual V-ribbed belts. .

  Another example of use of the fiber cord of the present invention is a V-belt. A V-belt 21 shown in FIG. 2 has a core wire 23 embedded in an adhesive rubber layer 24 and a compressed rubber layer 26 that is an elastic layer on the lower side. The compressed rubber layer 26 may be provided with cogs at predetermined intervals along the longitudinal direction.

  Hereinafter, a description will be given with specific examples.

Example 1
A 1,100 dtex / 1 × 5 PET twisted cord was immersed in the first treatment liquid shown in Table 1, and then heat treated at 180 ° C. for 4 minutes.

  Next, after immersing in the RFL liquid (RFL1) shown in Table 3 using the latex 1 in Table 2, the film was heat treated at 230 ° C. for 2 minutes, and then immersed in the soaking rubber liquid shown in Table 4 at 4 at 150 ° C. Heat treated for minutes. As shown in Table 5, the soaking rubber liquid was prepared by dissolving an EPDM compound in toluene.

  A strip-shaped sample (width 10 mm × length 70 mm) was prepared by arranging the treated core wires. And it was allowed to stand for 8 hours in an atmosphere of temperature and humidity of 23 ° C. and 65% to adjust the state. Further, as shown in FIG. 3, the sample was set in an Olzen bending tester 30 to obtain a test piece 31. Then, as shown in FIG. 3, the test piece gripping tool 33 was driven to bend the test piece 31 with respect to the fulcrum 35. The bending moment of the test piece 31 was calculated from the bending angle of the test piece 31 at that time and the force applied to the test piece 31, and was defined as the core bending rigidity. Table 6 shows the values at that time.

  Further, the processing cords arranged in a 25 mm width with no gaps and the EPDM adhesive rubber blended as shown in Table 5 were press vulcanized at 160 ° C. for 30 minutes and 180 ° C. for 60 minutes, and they were peeled flat at room temperature. The force was measured and the adhesion between the treated cord and the adhesive rubber was evaluated. The results are shown in Table 6.

Example 2
The same treatment as in Example 1 was performed using the first treatment liquid shown in Table 1, and then immersed in the RFL liquid (RFL2) shown in Table 3 using the latex 2 in Table 2, followed by 2 at 230 ° C. Heat treated for minutes. A PET treatment cord was prepared, and the flat peeling force and the cord bending rigidity were measured in the same manner as in Example 1. In addition, a V-ribbed belt having a size of 3PK1100 was produced using the treatment cord. The obtained V-ribbed belt was set in a running test machine including a driving pulley having a diameter of 120 mm, a driven pulley, and a tension pulley having a diameter of 45 mm. The driving pulley was driven at 4,900 rpm while applying a load of 8.8 kW to the driven pulley and a load of 834 N to the tension pulley. After running for 500 hours, the peel force of two arbitrary cores was measured and compared with the peel force of two cores of a V-ribbed belt before running prepared under the same conditions. The results are also shown in Table 6.

Comparative Examples 1-3
After the same treatment as in Example 1 was performed using the first treatment liquid shown in Table 1, and then immersed in the RFL liquid (RFL3-5) shown in Table 3 using the latexes 3-5 in Table 2, 230 Heat treatment was performed at ° C for 2 minutes. A PET treatment cord is prepared, and the flat peeling force and the core bending bending rigidity are measured in the same manner as in Example 1. In addition, a belt having the same size as in Examples 1 and 2 is prepared, and a running test is performed under the same conditions. Then, the flat peel force was measured under the same conditions as in the example. The results are also shown in Table 6.

Examples 1 and 2 in which a vinylpyridine latex having a breaking strength of 5 kgf / cm ² or more of a film prepared by drying the latex as the latex of the RFL solution was used in Comparative Example 1 (breaking strength 2.4 kgf / cm ² ). Compared with Comparative Example 2 (breaking strength 3.6 kgf / cm ² ), the adhesive strength (press vulcanization adhesive strength, peel strength of two belt core wires) was high. This is presumably because the use of latex with high breaking strength prevented the permeation of amine compounds and radicals generated during vulcanization and the RFL coating of radicals (up barrier properties), resulting in improved adhesion.

Example 3
Next, the canvas made of cotton was immersed in the RFL solution (RFL1) shown in Table 3 using the latex 1 in Table 2, and then dried at 143 ° C. for 90 seconds.

  The dried canvas was arranged in a width of 25 mm, and the EPDM adhesive rubber shown in Table 5 was press vulcanized at 160 ° C. for 30 minutes, and a peel test was performed in a room temperature atmosphere and a 120 ° C. atmosphere to measure the adhesive strength. The results are shown in Table 7.

Example 4
A canvas made of the same material as in Example 3 was dipped in the RFL solution (RFL2) shown in Table 3 using the latex 2 in Table 2, and then dried at 143 ° C. for 90 seconds. Further, the flat peeling force was measured in the same manner as in Example 3. The results are shown in Table 7.

  In addition, the retention stability of the RFL solutions of Example 3 and Example 4 was evaluated. When it was allowed to stand for 30 days under a temperature condition of 30 ° C. and the appearance became a pudding shape, it was deemed unusable (×). The results are shown in Table 7.

Comparative Examples 4-6
After immersing in the RFL liquid (RFL3-5) shown in Table 3 using the latex 3-5 of Table 2, it was dried at 143 ° C for 90 seconds. Further, the flat peeling force was measured in the same manner as in Example 3. The results are shown in Table 7.

Examples 1 and 2 in which a vinylpyridine latex having a breaking strength of 5 kgf / cm ² or more of a film prepared by drying the latex as the latex of the RFL solution was used in Comparative Example 1 (breaking strength 2.4 kgf / cm ² ). Compared with Comparative Example 2 (breaking strength 3.6 kgf / cm ² ), the adhesive strength (press vulcanization adhesive strength, peel strength of two belt core wires) was high. This is presumably because the use of latex with high breaking strength prevented the permeation of amine compounds and radicals generated during vulcanization and the RFL coating of radicals (up barrier properties), resulting in improved adhesion. Further, Comparative Example 6 was inferior in the storage stability of the treatment liquid.

  The power transmission belt according to the present invention can be attached to a drive device for automobiles or general industries.

It is sectional drawing of the V-ribbed belt which concerns on this invention. It is sectional drawing of the V belt which concerns on this invention. It is the schematic which showed the method of measuring a core wire bending rigidity.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 V ribbed belt 2 Core wire 3 Adhesive rubber layer 4 Compression rubber layer 5 Reinforcement cloth 7 Rib 21 V belt 22 Reinforcement cloth 23 Core wire 24 Adhesive rubber layer 30 Olsen-type bending test machine 31 Test piece 33 Test piece grip 35

Claims (4)

  In a power transmission belt in which a core wire is embedded in an adhesive rubber layer along the longitudinal direction of the belt, a compression rubber layer is disposed on the transmission surface side adjacent to the adhesion rubber layer, and an extension rubber layer is disposed on the back surface side. The adhesive rubber layer is an ethylene / α-olefin rubber composition, and the fiber cord forming the core wire is treated with a first treatment liquid comprising an isocyanate compound or an epoxy compound, and then the latex is at least styrene. And a latex containing vinyl pyridine, wherein the content of the styrene is 30 to 60 parts by mass with respect to 100 parts by mass of the latex and is treated with a second treatment solution of resorcin-formalin-rubber latex, After treatment with a third treatment liquid in which a vulcanizing agent is added to the ethylene / α-olefin rubber composition, the ethylene / α-olefin rubber composition is densely bonded to the unvulcanized composition of ethylene / α-olefin rubber. Power transmission belt, characterized in that the vulcanization brought ethylene · alpha-olefin rubber composition and the fiber cords were bonded.   In a 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 the adhesive rubber layer or the compression rubber layer that contacts the cover canvas An ethylene / α-olefin rubber composition, wherein the cover canvas is a latex containing at least styrene and vinylpyridine, and the content of the styrene is 30 to 60 parts by mass with respect to 100 parts by mass of the latex. A power transmission belt comprising an ethylene / α-olefin rubber composition and a cover canvas adhered after treatment with a resorcin-formalin-rubber latex treatment solution.   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, wherein the adhesive rubber layer is an ethylene / α-olefin rubber composition The fiber cord forming the core wire is treated with a first treatment liquid comprising an isocyanate compound or an epoxy compound, and then the latex is a latex containing at least styrene and vinylpyridine, and the content of the styrene Is treated with a second treatment solution of resorcin-formalin-rubber latex containing 30-60 parts by mass with respect to 100 parts by mass of latex, and then a vulcanizing agent is added to the ethylene / α-olefin rubber composition. After the treatment with the third treatment liquid, the ethylene / α-olefin rubber is closely vulcanized with the unvulcanized composition of ethylene / α-olefin rubber. An adhesive rubber layer or a compressed rubber layer that adheres the rubber composition and the fiber cord and is in contact with the cover canvas is an ethylene / α-olefin rubber composition, and the latex includes at least styrene and vinyl pyridine on the cover canvas. An ethylene / α-olefin rubber composition after treatment with a treatment solution of resorcin-formalin-rubber latex containing 30-60 parts by mass of styrene with respect to 100 parts by mass of latex. A power transmission belt characterized by bonding an object and a cover canvas. The resorcinol - formaldehyde - strong fracture at the film state of the rubber latex used for rubber latex, power transmission belt according to any of claims 1 to 3 is 5~60kgf / cm ^2.

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