JP2009250293A - V-ribbed belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber composition capable of continuously maintaining wettability with water and a V-ribbed belt capable of providing high transmission torque even under a high slip condition when the same is covered by water during the pouring of water. <P>SOLUTION: The V-ribbed belt 1 includes an adhesion layer 3 having core wire 2 embedded therein along a belt longitudinal direction, and a compression layer 4 which is a rib 6 adjoining to the adhesion layer 3 and extending in the belt longitudinal direction. The rib 6 is composed of a rubber composition combining plasticizing ether ester and short fibers with an ethylene-α-olefin elastomer. The short fibers project out of and plasticizing ether ester bleeds on a friction transmission surface 40 of a rib surface. A contact angle of water and the friction transmission surface 40 after water is dropped on the friction transmission surface 40 is 2-50°. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a V-ribbed belt having a rubber layer in which a core wire is embedded along the longitudinal direction of the belt and a rib portion extending in the longitudinal direction of the belt adjacent to the rubber layer.

  Conventionally, rubbers such as natural rubber, styrene / butadiene rubber, and chloroprene rubber have been generally used as power transmission belts used in automobile engines and the like. However, in recent years, with the social demand for energy saving and downsizing, parts in the engine room of automobiles tend to be densely arranged, and as a result, the ambient temperature in the engine room is higher than in the past. It is rising.

  It has been pointed out that the rubber constituting the power transmission belt is cured under such a high temperature atmosphere and cracks occur early. In addition, as the energy is saved, the rotational fluctuation of the engine increases, and the influence thereof causes an increase in the tension fluctuation of the power transmission belt, causing problems such as early wear and sound generation. Furthermore, since a rubber containing halogen such as chloroprene leads to generation of dioxins, a belt made of a rubber not containing halogen, which is an environmental load substance, has recently been demanded.

Recently, ethylene / α-olefin rubbers such as ethylene / propylene rubber (EPM) or ethylene / propylene / diene copolymer rubber (EPDM) have excellent heat resistance. At the same time, it is a relatively inexpensive polymer and is expected to be promising because it satisfies the requirement of dehalogenation. Specifically, a power transmission belt using an ethylene / α-olefin elastomer reinforced with a metal salt of an α-β-unsaturated organic acid has been proposed (for example, see Patent Document 1).
Japanese National Patent Publication No. 9-500930

  However, since the ethylene / α-olefin elastomer has poor wettability with water compared to chloroprene rubber and easily repels water, the infiltration state of water between the belt and the pulley is not uniform when wet. And, in a place where water does not enter, the friction coefficient does not decrease and the belt is in close contact with the pulley, but in a part where water enters, the friction coefficient partially decreases and the belt and pulley There is a problem that stick-slip noise is likely to occur because slip occurs between the two.

  On the other hand, since the friction coefficient of the belt surface is high, it has been pointed out that abnormal noise is generated even during normal running. On the other hand, it was required to keep the friction coefficient low to some extent. However, for example, when a large amount of lubricant was added to lower the friction coefficient, there was a problem that adhesive wear occurred.

  An object of the present invention is to provide a rubber composition in which wettability with water is continuously maintained, and a V-ribbed belt capable of obtaining a high transmission torque even in a high slip state at the time of water injection.

  The invention described in claim 1 is a V-ribbed belt having a rubber layer in which a core wire is embedded along the longitudinal direction of the belt, and a compression layer which is a rib portion extending in the longitudinal direction of the belt adjacent to the rubber layer. The part is composed of a rubber composition in which an ether ester plasticizer and short fibers are blended with an ethylene / α-olefin elastomer. On the frictional transmission surface of the rib surface, the short fibers protrude and the ether ester plasticizer The contact angle between the friction transmission surface and water after bleeding and dropping water onto the friction transmission surface is 2 to 50 °. Since the ether ester plasticizer has a characteristic that it is difficult to adapt to the ethylene / α-olefin elastomer, the contact angle between the friction transmission surface and water is as small as 2 to 50 ° by constantly bleeding to the surface. The friction transmission surface continuously maintains the wettability with water, and a high transmission torque can be obtained even in a high slip state when the water is poured.

  In the invention according to claim 2, the contact angle between the friction transmission surface and water after 60 seconds has elapsed after dropping water on the friction transmission surface is 2 to 15 °, and the wettability with water is continuously maintained. It is maintained, and a high transmission torque can be obtained even in a high slip state at the time of water injection.

  The invention according to claim 3 of the present application includes 5 to 25 parts by weight of an ether ester plasticizer with respect to 100 parts by weight of the ethylene / α-olefin elastomer, and continuously wets the surface by bleed to the surface. Maintained.

  The invention of claim 4 of the present application is in a V-ribbed belt in which a surfactant is further added to the ethylene / α-olefin elastomer, and the friction transmission surface can be improved by adding a surfactant. Affinity with water can be improved. That is, the surfactant improves the hydrophilicity of the friction transmission surface, and as a result, noise due to rubbing such as misalignment is reduced.

  In the V-ribbed belt according to the present invention, the plasticizer always bleeds to the surface, and the contact angle between the friction transmission surface and water after dropping water on the friction transmission surface is 2 to 50 °. The wettability with water is continuously maintained, the friction transmission surface continuously maintains the wettability with water, and a high transmission torque can be obtained even in a high slip state when the water is poured. Further, by adding a surfactant, the hydrophilicity of the friction transmission surface is improved, and as a result, abnormal noise due to rubbing such as misalignment is reduced.

  A V-ribbed belt having a plurality of rib portions extending in the longitudinal direction of the belt according to an embodiment of the present invention will be described.

  As shown in FIG. 1, the V-ribbed belt 1 includes an adhesive layer 3 in which a core wire 2 is embedded in the longitudinal direction of the belt, a compression layer 4 provided on one surface of the adhesive layer 3, and the other of the adhesive layer 3. And a stretch layer 5 made of a cover canvas covering the surface of the cover. The compressed layer 4 is provided with a plurality of rib portions 6 having a substantially triangular cross section extending in the belt longitudinal direction. Here, the friction transmission surface refers to the surface layer of the compression layer 4.

  The core wire 2 used in the present invention includes polyethylene terephthalate (PET) fiber, polyethylene naphthalate (PEN) fiber, polytrimethylene terephthalate (PTT) fiber, polybutylene terephthalate (PBT) fiber, polyparaphenylene benzobisoxazole (PBO). ) Twisted cords composed of fibers, polyamide fibers, glass fibers, aramid fibers, or the like can be used.

  The core wire is preferably subjected to an adhesive treatment. For example, (1) After impregnating the untreated cord into a tank containing a treatment liquid selected from an epoxy compound and an isocyanate compound, and pre-dip (2) 160 Dry in a drying oven set at a temperature of ~ 200 ° C for 30-600 seconds, (3) then immerse in a tank containing an adhesive solution consisting of RFL, and (4) set the temperature at 210-260 ° C The stretched heat fixing processor can be stretched by −1 to 3% for 30 to 600 seconds to form a stretched cord.

  The RFL treatment liquid is a mixture of resorcin and formaldehyde precondensate with rubber latex. In this case, the molar ratio of resorcin and formaldehyde is preferably 1: 2 to 2: 1 in order to increase the adhesive force. . If the molar ratio is less than 1/2, the three-dimensional reaction of resorcin-formaldehyde resin proceeds too much and gels, while if it exceeds 2/1, the reaction between resorcin and formaldehyde does not progress so much, resulting in a decrease in adhesive strength. To do.

  The canvas constituting the stretch layer 5 is a fiber base selected from woven fabric, knitted fabric, non-woven fabric, and the like. Examples of the constituent fiber materials include natural fibers such as cotton and hemp, inorganic fibers such as metal fibers and glass fibers, and polyamides, polyesters, polyethylenes, polyurethanes, polystyrenes, polyfluoroethylenes, polyacryls, polyvinyl alcohols, and aromatics. Organic fibers such as Aripolyester and Aramid. In the case of a woven fabric, these yarns are woven by plain weaving, twill weaving, satin weaving or the like.

  The canvas is preferably immersed in the RFL liquid according to a known technique. In addition, after being immersed in the RFL solution, it is possible to perform an immersion treatment in friction in which unvulcanized rubber is rubbed into a canvas or in a soaking solution in which rubber is dissolved in a solvent. The RFL solution may be mixed with a carbon black solution as appropriate to blacken the treatment, and a known surfactant may be added in an amount of 0.1 to 5.0% by mass.

  The adhesive layer 3 is desirably made of a blend rubber obtained by mixing ethylene / α-olefin rubber alone or a partner rubber made of other kinds of rubber as a rubber component. As the other rubber blended with ethylene / α-olefin rubber, butadiene rubber (BR), styrene / butadiene rubber (SBR), nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), chloroprene rubber (CR), Mention may be made of at least one rubber of butyl rubber (IIR) and natural rubber (NR). Of course, it is also possible to use the same rubber composition as described above.

  Here, a rubber composition which is a feature of the present invention is used for the compression layer 4 (rib portion 6). As this rubber composition, 5 to 25 parts by weight of an ether ester plasticizer is blended with 100 parts by weight of an ethylene / α-olefin elastomer. If the added amount of the plasticizer is less than 5 parts by weight, it is insufficient as an amount to cover the belt surface, so it is difficult to ensure uniform water wettability, and the effect as a lubricant is poor. . On the other hand, when the blending amount exceeds 25 parts by weight, there is a problem that, on the contrary, the surface friction coefficient is remarkably lowered and the wear resistance is extremely lowered.

  Examples of the ethylene / α-olefin elastomer include a copolymer of ethylene and α-olefin (propylene, butene, hexene, or octene), a copolymer of ethylene, the α-olefin, and a nonconjugated diene, and the like. Examples of the diene component include non-conjugated dienes having 5 to 15 carbon atoms such as ethylidene norbornene, dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, and methylene norbornene. Specifically, it refers to rubber such as EPM and EPDM.

  The ether ester plasticizer is not particularly limited with respect to its production method, but can be easily obtained by reacting 2-ethylhexyl acid and ether glycol in a molar ratio of 2: 1. It can be obtained by reacting a mixed ether glycol containing a predetermined amount of pentaethylene glycol, hexaethylene glycol or heptaethylene glycol with 2-ethylhexyl acid by a conventional method, but pentaethylene glycol, hexaethylene glycol or heptaethylene glycol. Etc., respectively, can be produced by mixing them so that the average polymerization degree of polyethylene glycol using diester obtained by reacting 2-ethylhexylic acid with 2-ethylhexylic acid is 5-10. Specifically, Adekasizer RS-107, RS-735, RS-700 manufactured by Asahi Denka Kogyo Co., Ltd. are applicable. The plasticizer preferably has an average molecular weight of 200 to 2,000. If the average molecular weight is within this range, an appropriate bleed effect is obtained and wettability with water is good.

  A nonionic surfactant is used as the surfactant. Nonionic surfactants include polyoxyethylene derivatives and polyhydric alcohol derivatives.

  Examples of the polyoxyethylene derivative include polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene polyoxypropylene block copolymer, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene Examples include fatty acid esters, polyoxyethylene / alkylamines, and polyoxyethylene alkylamides.

  The polyhydric alcohol type nonionic surfactant is a nonionic surfactant obtained by bonding a hydrophobic group such as a higher fatty acid to a polyhydric alcohol such as glycerol or pentaerythritol. Examples of the polyhydric alcohol type nonionic surfactant include fatty acid esters of glycerol such as glycerol monostearate and glycerol monooleate, fatty acid esters of pentaerythritol such as pentaerythritol beef tallow fatty acid ester, polyoxyethylene sorbitan mono Examples include sorbitol such as laurate and polyoxyethylene sorbitan monostearate, fatty acid esters of sorbitan, fatty acid esters of sucrose, alkyl ethers of polyhydric alcohols, fatty acid amides of alkanolamines such as coconut fatty acid diethanolamide, and the like.

  The surfactant is added in an amount of 1 to 20 parts by weight, more preferably 2 to 10 parts by weight of the surfactant with respect to 100 parts by weight of the ethylene / α-olefin elastomer. The modification of is not fully demonstrated. On the other hand, when the amount exceeds 20 parts by weight, a tendency of a decrease in physical properties, particularly a decrease in modulus appears.

  The rubber composition can be used in combination with a paraffinic and / or naphthenic petroleum softening agent which is a petroleum softening agent. The above softeners have a characteristic that is easy to adapt to elastomers and ether ester plasticizers, but ether ester plasticizers have a characteristic that is difficult to adapt to the above softeners and elastomers. In particular, it tends to move away from the elastomer and the softening agent, which continuously generates bleed.

  The blending amount is preferably 3 to 20 parts by weight, more preferably 5 to 15 parts by weight with respect to 100 parts by weight of the ethylene / α-olefin elastomer. If it is less than 3 parts by weight, the effect of bleeding the ether ester plasticizer is poor. On the other hand, if it exceeds 20 parts by weight, there is a problem that the adhesive wear resistance is lowered.

  Examples of the paraffinic petroleum softener include paraffinic compounds having 4 to 155 carbon atoms, preferably paraffinic compounds having 4 to 50 carbon atoms. Specifically, n-paraffins (linear saturated hydrocarbons) such as butane, pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, etc., isobutane, isopentane, Isoparaffins (branched saturated hydrocarbons) such as neopentane, isohexane, isopentane, neohexane, 2,3-dimethylbutane, 2-methylhexane, 3-methylhexane, 3-ethylpentane, and derivatives of these saturated hydrocarbons Can be mentioned. These paraffins are used in a mixture and are preferably liquid at room temperature.

  Commercially available products of the above-mentioned paraffinic petroleum softeners include NA Solvent (isoparaffinic hydrocarbon oil) manufactured by Nippon Oil & Fats, PW-90 (n-paraffinic process oil) manufactured by Idemitsu Kosan Co., Ltd., and Idemitsu Petrochemical Co., Ltd. Examples include IP-solvent 2835 (synthetic isoparaffinic hydrocarbon, 99.8 wt% or more isoparaffin) manufactured by company, Neothiozol (n-paraffinic process oil) manufactured by Sanko Chemical Co., Ltd., and the like.

  The rubber composition improves the water wettability of the friction transmission surface, improves the quietness by increasing the adhesion to the pulley of the belt even during water injection, and exhibits moderate bleeding and acts as a lubricant. As a result, sound generation during traveling can be suppressed, and cracking of the friction transmission surface can be prevented to improve belt durability.

  An organic peroxide can be blended in the rubber composition as a crosslinking agent. 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 preferably used alone or as a mixture in the range of 0.5 to 8 parts by weight with respect to 100 parts by weight of the elastomer.

  Further, the rubber composition may contain 0.5 to 13 parts by weight of N, N′-m-phenylene dimaleimide and / or quinonedioxime with respect to 100 parts by weight of the elastomer component. N, N′-m-phenylene dimaleimide and / or quinonedioxime acts as a co-crosslinking agent, and if less than 0.5 part by weight, the effect of addition is not significant, and if it exceeds 13 parts by weight, tearing force and adhesion The force drops sharply. At this time, when N, N′-m-phenylene dimaleimide is selected as the co-crosslinking agent, the cross-linking density is high, the wear resistance is high, and the difference in transmission performance between water injection and drying is small. is there. Further, when quinone dioximes are selected, there is a feature that the adhesiveness with the fiber base material is excellent.

  In addition to that, those used in ordinary rubber compounds such as short fibers, anti-aging agents, stabilizers, processing aids, and colorants are used as necessary. There are no particular limitations on the method of mixing these compounding components into the rubber composition, and the kneading can be appropriately carried out by known means and methods using, for example, a Banbury mixer, a kneader or the like.

  The V-ribbed belt is not limited to the configuration shown in FIG. 1, and for example, a V-ribbed belt in which no adhesive layer is disposed, a V-ribbed belt in which rubber is exposed without attaching a canvas to the back, and the like belong to the technical scope of the present invention. . Hereinafter, these embodiments will be described with reference to the drawings.

  The V-ribbed belt 21 shown in FIG. 2 has a stretch layer 25 formed of a rubber composition with a back surface 28 provided with a flocking layer 24, and an adhesive layer 22 disposed below the stretch layer 25. The layer 26 is arranged. The core wire 23 is embedded in the main body along the longitudinal direction of the belt, and a part thereof is in contact with the stretched layer 25 and the remaining part is in contact with the adhesive layer 22. The compressed layer 26 is provided with a plurality of ribs 27 having a substantially triangular cross section extending in the belt longitudinal direction. Here, the short fibers contained in the compressed layer 26 exhibit a flow state along the rib shape, and the short fibers near the surface are oriented along the rib shape.

  A V-ribbed belt 31 shown in FIG. 3 has a configuration in which a back surface 38 is formed of a rubber layer containing a short fiber 34 and a compression layer 36 is disposed below the stretch layer 35. The core wire 33 is embedded in the main body along the longitudinal direction of the belt, and a part thereof is in contact with the stretch layer 35 and the remaining part is in contact with the compression layer 36. The compression layer 35 is provided with a plurality of ribs 37 having a substantially triangular cross section extending in the belt longitudinal direction, and a flocking layer 39 is provided on the rib surface. Here, the short fibers contained in the stretched layer 35 are oriented in a random direction.

  Here, FIG. 3 shows a configuration in which the stretch layer 35 is not formed of a canvas and is formed of a rubber composition containing short fibers, but at this time, in order to suppress abnormal noise during driving of the back surface, An uneven pattern can be provided. Examples of the concavo-convex pattern include a knitted fabric pattern, a woven fabric pattern, a suede woven fabric pattern, and the like, and most preferably a woven fabric pattern. Moreover, as a short fiber, polyester, aramid, nylon, cotton, etc. can be mix | blended as desired. In addition, the same rubber composition as that described above can be used for the rubber composition and the core wire constituting the stretch layer, the compression layer, and the adhesive layer.

  In FIG. 3, the short fibers contained in the stretched layer 35 are oriented in a random direction, but may be oriented in one direction such as in the belt width direction. In addition, when oriented in a random direction, there is a feature that the generation of cracks and cracks from multiple directions can be suppressed. At this time, if a short fiber (for example, a milled fiber) having a bent portion is selected as the short fiber, more It has a feature that it can withstand the force acting from the direction.

  In the case where the adhesive layer is not disposed as shown in FIG. 3, the core wire 33 is embedded in the belt main body at the boundary region between the stretch layer 35 and the compression layer 36. At this time, considering the adhesiveness between the core wire 33 and the belt body, it is desirable that one of the stretched layer 35 and the compressed layer 36 is made of a rubber composition containing no short fibers.

  In FIG. 2, the stretch layer 25 has a structure in which the flocked layer 24 is provided on the surface of the rubber composition that does not contain short fibers, but a flocked layer is provided on the surface of the rubber composition that contains short fibers. It is also possible.

  In FIG. 2, the short fibers contained in the compressed layer 26 are in a flow state along the rib shape, but the short fibers may be oriented in the width direction.

  When the V-ribbed belt performs back surface transmission, the surface of the stretch layer can also be a friction transmission surface. Therefore, the stretch layer may be composed of the rubber composition of the present invention.

As shown in FIG. 4, the contact angle between the friction transmission surface and the water is determined by the contact angle φ = 2 tan ⁻¹ (h / r) ( Here, φ is the contact angle, h is the height of the water droplet, and r is the radius of the water droplet.) In the present invention, water is dropped on the friction transmission surface 40 from which the short fibers protrude. The contact angle between the friction transmission surface 40 and water is 2 to 50 °. That is, the contact angle between the friction transmission surface 40 and water immediately after dropping water on the friction transmission surface 40 (after 1 second) is 20 to 50 °, and after 60 seconds have passed since water was dropped on the friction transmission surface 40. The contact angle between the friction transmission surface 40 and water is 2 to 15 °. If it is this range, the wettability with water will be maintained continuously.

  Next, the present invention will be specifically described with reference to examples.

Examples 1-7, Comparative Examples 1-4
In the V-ribbed belts of Examples 1 to 7 and Comparative Examples 1 to 4 below, a cord made of polyester fiber rope is embedded in an adhesive rubber layer, and two plies of rubber cotton canvas are applied to one surface of the adhesive rubber layer. The compressed rubber layer provided on the other side of the adhesive rubber layer is laminated and three rib portions are arranged in the longitudinal direction of the belt.

  Here, as a compression layer, EPDM 100 parts by weight, zinc white 5 parts by weight, stearic acid 1 part by weight, HAF carbon black 65 parts by weight, anti-aging agent 2 parts by weight, co-crosslinking agent (N, N′-m-phenylene diene) Maleimide), 8 parts by weight of organic peroxide, 0.3 part by weight of sulfur, and a predetermined amount (parts by weight) of short fibers, polyether ester plasticizer, polyether plasticizer, paraffin oil, as shown in Table 1. A product prepared from a surfactant, kneaded with a Banbury mixer, and rolled with a calender roll was used. Here, the compressed layer contains short fibers, and the short fibers are oriented in the belt width direction. On the other hand, the adhesive layer has a rubber composition obtained by removing short fibers from the rubber composition shown in Table 1.

  As a belt manufacturing method, the following known methods were used. First, a 2-ply cotton canvas with rubber and an adhesive rubber layer are wrapped around a flat cylindrical molding mold, a core wire is spun, a compressed rubber layer is wound around, and a vulcanization jacket is placed on the compressed rubber layer. Insert. Next, after the molding mold is placed in a vulcanizing can and vulcanized, the cylindrical vulcanizing sleeve is taken out from the molding mold. Then, the compressed rubber layer of the vulcanization sleeve was ground by a grinder to form a plurality of rib portions, and then cut into individual belts by a cutter to finish a V-ribbed belt.

  Next, as described below, the contact angle between the friction transmission surface (short fiber protruding surface) of the V-ribbed belt and water, the contact angle between the vulcanized rubber sheet surface and water, and the transmission torque in the submerged transmission performance test And the slip rate. The results are shown in Table 1.

  In the measurement of the contact angle with water, water is dropped on the surface, and a φ / 2 method is used from a projection photograph of the dropped water using a fully automatic contact angle (CA-W type) manufactured by Kyowa Interface Science Co., Ltd. as a measuring instrument. The contact angle was calculated. The measurement calculated the contact angle immediately after dropping (after 1 second) and after 60 seconds.

  In the above-described transmission performance test under water, a driving pulley (diameter 120 mm), a driven pulley (diameter 160 mm), an idler pulley (diameter 80 mm), and a tension pulley (diameter 120 mm) are arranged in this order as a running test machine. A ribbed belt was hung, and the winding angle of the belt around the driving pulley was adjusted to 90 °, and the winding angle of the driven pulley was adjusted to 160 °. The running conditions were room temperature, the rotational speed of the driving pulley was 2,000 rpm, the belt tension was 5 kgf / rib, and a load was applied to the driven pulley to promote slip. Further, the slip ratio and transmission torque when water was injected (200 cc) between the driving pulley and the driven pulley were obtained.

  From the results in Table 1, it can be seen that Examples 1-4 and 6-7 have a small contact angle with water and are superior in affinity. Further, it can be seen that even when a surfactant is used in combination as in Example 5, the contact angle with water is small and the affinity is superior. On the other hand, in Comparative Examples 1, 2, and 4, the contact angle with water is large, indicating that the wettability with water is poor. Since Comparative Example 3 contains an excessive amount of ether ester plasticizer, it can be seen that the contact angle with water is extremely small, that is, the bleed amount is excessive.

  Further, in Examples 1 to 7 in the transmission performance test, the belt has a high transmission torque even in a high slip state. This indicates that the transmission performance is maintained even in a slip state when wet, and that the belt is less likely to be in a full slip state that contributes to the generation of slip noise.

  On the other hand, in Comparative Examples 1 and 2, the transmission torque is high, but the slip ratio is low, and it can be seen that compared to the Example, it is likely to be in a state of total slip, and abnormal noise is likely to occur. In Comparative Example 3, the transmission torque was low because the bleed amount was excessive. In Comparative Example 4, only the paraffin oil was blended and the wettability with water was poor, and as a result, a satisfactory transmission performance was not obtained.

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

It is a section perspective view of the V ribbed belt which is a friction transmission belt concerning the present invention. It is sectional drawing of another V-ribbed belt which is a friction transmission belt which concerns on this invention. It is sectional drawing of another V-ribbed belt which is a friction transmission belt which concerns on this invention. Indicates the contact angle between the friction transmission surface and water.

Explanation of symbols

1 V-ribbed belt 2 Core wire 3 Adhesive layer 4 Compression layer 5 Stretch layer 6 Rib part

Claims (4)

  In a V-ribbed belt having a rubber layer in which a core wire is embedded along the longitudinal direction of the belt and a compression layer that is a rib portion extending in the longitudinal direction of the belt adjacent to the rubber layer, the rib portion is an ethylene / α-olefin elastomer. It is composed of a rubber composition containing an ether ester plasticizer and short fibers, and on the friction transmission surface of the rib surface, the short fibers protrude and the ether ester plasticizer bleeds, and water is supplied to the friction transmission surface. A V-ribbed belt, wherein a contact angle between the frictional transmission surface after dropping and water is 2 to 50 °.   2. The V-ribbed belt according to claim 1, wherein the contact angle between the friction transmission surface and water after 60 seconds have passed after dropping water on the friction transmission surface is 2 to 15 °.   The V-ribbed belt according to claim 1 or 2, wherein the ether ester plasticizer is contained in an amount of 5 to 25 parts by weight based on 100 parts by weight of the ethylene / α-olefin elastomer.   The V-ribbed belt according to any one of claims 1 to 4, wherein a surfactant is further added to the ethylene / α-olefin elastomer.

Images