JP5292212B2 - Friction transmission belt and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a friction drive belt obtaining an excellent noise suppressing effect when submerged. <P>SOLUTION: The friction drive belt B transmits power with a belt body 10 wound to contact a pulley. At least a pulley contact portion 15 of the belt body 10 of the friction transmission belt B is formed of a rubber composition containing layer silicate blended in a raw material rubber and having a moisture content of 0.70 mass% or more. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a friction transmission belt in which a belt main body is wound so as to contact a pulley and transmits power, and a method for manufacturing the same.

  In recent years, there has been an increasing need to prevent the generation of abnormal noise in a V-ribbed belt while driving a car. There are many types of abnormal noise of the V-ribbed belt, and one of them is a belt slip noise when wet.

In contrast, Patent Document 1, a rib portion which is a friction transmission surface with respect to 100 parts by weight of ethylene -α- olefin elastomer, solubility parameter ^{8.3~10.7 (cal / cm 3) 1} / It is disclosed that the rubber composition is composed of 10 to 25 parts by weight of a plasticizer ² and 60 to 110 parts by weight of an inorganic filler.

  Patent Document 2 discloses that the transmission surface is formed of a rubber composition containing 5 parts by weight or more of a hydrophilic inorganic filler with respect to 100 parts by weight of rubber.

  In Patent Document 3, the compressed rubber layer is composed of 10 to 40 parts by weight of polyamide short fibers, 30 to 60 parts by weight of carbon black with respect to 100 parts by weight of an ethylene-α-olefin elastomer having an ethylene content of 50 to 70% by weight, Tan δ obtained by measuring dynamic viscoelasticity in tensile mode at a frequency of 10 Hz and a temperature of 0 ° C. is 0.080 or more by blending 10 to 60 parts by weight of an inorganic filler composed of metal carbonate and / or metal silicate. It is disclosed to form with a rubber composition.

  Patent Document 4 discloses that a rib portion serving as a friction transmission surface is composed of a rubber composition in which 1 to 25 parts by weight of a surfactant is blended with 100 parts by weight of an ethylene-α-olefin elastomer. Yes.

  Patent Document 5 discloses that the rib portion serving as the friction transmission surface is composed of a rubber composition in which 5 to 25 parts by weight of an ether ester plasticizer is blended with 100 parts by weight of the ethylene-α-olefin elastomer. Has been.

JP 2007-232205 A JP 2007-120526 A JP 2006-64174 A JP 2008-185162 A JP 2008-195914 A

  However, in the configuration of Patent Document 1, there is a problem that abnormal noise is likely to be generated when the plasticizer is bleeded and adhesive wear or water is not applied. In the configuration of Patent Document 2, the wettability of the hydrophilic inorganic filler with water is not sufficient, and it cannot be said that the noise suppression effect is sufficient under high load conditions. With the configuration of Patent Document 3, a sufficient noise suppression effect cannot be exhibited in a state in which the slip rate is very large as in the case of flooding. In patent documents 4 and 5, since the affinity with water on the rubber surface is insufficient, a sufficient noise suppression effect cannot be exhibited.

  An object of the present invention is to obtain an excellent noise suppressing effect when the friction transmission belt is wet.

  The present invention is a friction transmission belt that is wound around a belt body so as to be in contact with a pulley and transmits power, and at least the pulley contact portion of the belt body includes a raw material rubber mixed with layered silicate and a moisture content. It is formed with the rubber composition which is 0.70 mass% or more.

  The present invention relates to a method for producing a friction transmission belt, in which at least a pulley contact portion of the belt body is formed from a rubber composition in which a layered silicate is mixed with a raw rubber, and a post-molding friction transmission belt is formed in a steam atmosphere or underwater. The method includes a step of putting in a predetermined time.

  According to the present invention, at least the pulley contact portion of the belt body is formed of the rubber composition in which the layered silicate is blended with the raw rubber and the moisture content is 0.70% by mass or more. An excellent noise suppression effect can be obtained.

It is a perspective view which shows the V-ribbed belt which concerns on embodiment. It is a figure which shows the pulley layout of the auxiliary machine drive belt transmission of a motor vehicle. It is a figure which shows the pulley layout of the belt running test machine for abnormal noise evaluation at the time of flooding. It is a figure which shows the pulley layout of the belt running test machine for abrasion evaluation.

  Hereinafter, embodiments will be described in detail with reference to the drawings.

  FIG. 1 shows a V-ribbed belt B (friction transmission belt) according to this embodiment. The V-ribbed belt B is used, for example, to constitute an auxiliary machine drive belt transmission provided in an engine room of an automobile, and has a belt circumferential length of 700 to 3000 mm, a belt width of 10 to 36 mm, and a belt thickness. 4.0-5.0 mm.

  The V-ribbed belt B includes a V-ribbed belt main body 10 configured as a triple layer of a compression rubber layer 11 on the inner peripheral side of the belt, an intermediate adhesive rubber layer 12 and a back rubber layer 13 on the outer peripheral side of the belt. A core wire 14 is embedded in the layer 12 so as to form a spiral having a pitch in the belt width direction.

  The compressed rubber layer 11 constitutes a pulley contact portion, and is provided so that a plurality of V ribs 15 hang down to the belt inner peripheral side. Each of the plurality of V ribs 15 is formed in a ridge having a substantially inverted triangular cross section extending in the belt length direction, and arranged in parallel in the belt width direction. Each V rib 15 is formed, for example, with a rib height of 2.0 to 3.0 mm and a width between base ends of 1.0 to 3.6 mm. The number of ribs is, for example, 3 to 6 (in FIG. 1, the number of ribs is 6). The compressed rubber layer 11 is formed of a rubber composition obtained by heating and pressurizing an uncrosslinked rubber composition in which various compounding agents are blended and mixed with raw rubber to be crosslinked with a crosslinking agent.

  Examples of the raw rubber of the rubber composition forming the compressed rubber layer 11 include, for example, ethylene-α-olefin elastomer, chloroprene rubber (CR), chlorosulfonated polyethylene rubber (CSM), hydrogenated acrylonitrile rubber (H-NBR), Examples include natural rubber. The raw rubber may be composed of a single species, or may be composed of a blend of a plurality of species.

  It is preferable that raw material rubber contains an ethylene-alpha-olefin elastomer among the above. Examples of the ethylene-α-olefin elastomer include ethylene-propylene-diene rubber (EPDM), ethylene-propylene copolymer (EPM), ethylene-butene copolymer (EBM), and ethylene-octene copolymer (EOM).

  Examples of the compounding agent include reinforcing materials such as layered silicate and carbon black, vulcanization accelerators, crosslinking agents, anti-aging agents, softening agents and the like.

  The layered silicate is composed of at least one selected from the smectite group, the vermiculite group, and the kaolin group. Therefore, the layered silicate may be composed of a single species of smectite group, vermiculite group, and kaolin group, and more than one of smectite group, vermiculite group, and kaolin group. It may be composed of seeds, and may be composed of a plurality of kinds selected from at least one kind of smectite group, at least one kind of vermiculite group, and at least one kind of kaolin group.

  As the layered silicate, examples of the smectite group include montmorillonite, beidellite, saponite, and hectorite. Of these, montmorillonite is preferred.

  The layered silicate is water swellable and preferably has a swelling power of 20 ml / 2 g or more, more preferably 40 ml / 2 g or more. The swelling power of the layered silicate is measured by the Japan Bentonite Industry Association standard test method. Specifically, 2 g of a layered silicate sample is weighed, and a graduated cylinder (with a capacity of 200 ml or more) containing water (about 150 ml) is prepared. The layered silicate sample is then gradually added to the graduated cylinder. At this time, it does not shake or vibrate and waits for the layered silicate to settle due to water absorption and swelling. Also, the layered silicate sample should be added after the previous one has sunk to some extent. When all 2 g of the layered silicate sample has been added, the sample is allowed to stand for 24 hours. The scale of the graduated cylinder at the boundary between the layered silicate sample that has swelled and settled and the supernatant is read, and the value is taken as the swelling power.

  The layered silicate preferably has a cation exchange capacity (CEC) of 70 meg / 100 g or more, more preferably 90 meg / 100 g or more. The cation exchange capacity of the layered silicate is measured by a standard test method of the Japan Bentonite Industry Association. Specifically, 0.4 to 0.5 g of a layered silicate sample is weighed and placed in a brewing tube. Next, put the 1N ammonium acetate solution into the leaching tube little by little, and when the sample has completely penetrated, set the brewing tube to the apparatus, add 100 ml of 1N ammonium acetate solution to the leaching solution container, and complete the leaching in 4 to 24 hours Adjust the cock to let it flow down. After thoroughly washing the leachate container with water, 50 ml of 80 mass% ethyl alcohol is added to the leachate container and allowed to flow down to wash the layered silicate sample. Subsequently, after thoroughly washing the leachate container and the receiver, 100 ml of a 10% by mass potassium chloride solution is added to the leachate container and allowed to flow down to exchange ammonium ions in the layered silicate sample with potassium ions. Then, the potassium chloride solution of heavy equipment is transferred to a distillation apparatus, and ammonia is distilled according to the Kjeldahl method (at this time, a small amount of zinc particles is added to prevent bumping), and the distillate is subjected to 0.1 N sulfuric acid, and excess Of sulfuric acid is titrated with 0.1N sodium hydroxide solution. At the same time, a blank test is performed, and the cation exchange capacity is calculated based on the following formula.

Cation exchange capacity = ((A−B) × f × 10) / (S × (100−M) / 100)
A: ml number of 0.1N sodium hydroxide required for the blank test B: ml number of 0.1N sodium hydroxide actually required f: factor of 0.1N sodium hydroxide S: sampling amount (g)
M: moisture content of the sample (% by mass)
The layered silicate preferably has a particle size of 0.05 to 120 μm, and more preferably 0.5 to 80 μm.

  The amount of the layered silicate based on 100 parts by mass of the raw rubber is preferably 10 to 80 parts by mass, more preferably 30 to 60 parts by mass, and even more preferably 30 to 45 parts by mass.

  Since the rubber composition forming the compressed rubber layer 11 includes the layered silicate as described above, the X-ray diffraction measurement has a detection peak at 2θ = 9 ° or less when the measurement range is 2θ = 0.2 to 15 °. It is preferable that 2θ = 8 ° or less.

  The occupied area ratio of the layered silicate exposed on the surface of the V rib 15 is preferably 12% or more, and more preferably 16% or more. The occupation area ratio of the layered silicate exposed on the surface of the V rib 15 is obtained by calculating the area ratio of the bright spot of the Si element in the mapping image of the Si element in the scanning electron microscope observation (for example, 300 times magnification). Can do. Examples of the scanning electron microscope include a scanning electron microscope S-4800 manufactured by Hitachi High-Technologies Corporation, and examples of the elemental analysis apparatus include an X-ray analyzer EMAX EX-250 manufactured by Horiba, Ltd.

  As carbon black, for example, channel black; furnace black such as SAF, ISAF, N-339, HAF, N-351, MAF, FEF, SRF, GPF, ECF, N-234; FT, MT, etc. Thermal black; acetylene black. Silica is also mentioned as a reinforcing agent. The reinforcing agent may be composed of a single species or a plurality of species. The reinforcing material preferably has a blending amount of 30 to 80 parts by mass with respect to 100 parts by mass of the raw rubber from the viewpoint that the balance between wear resistance and flex resistance becomes good.

  Examples of the vulcanization accelerator include metal oxides such as magnesium oxide and zinc oxide (zinc white), fatty acids such as metal carbonates and stearic acid, and derivatives thereof. The vulcanization accelerator may be composed of a single species or a plurality of species. The amount of the vulcanization accelerator based on 100 parts by mass of the raw rubber is, for example, 0.5 to 8 parts by mass.

  Examples of the crosslinking agent include sulfur and organic peroxides. As the crosslinking agent, sulfur may be used, organic peroxide may be used, or both of them may be used in combination. In the case of sulfur, the cross-linking agent is preferably 0.5 to 4.0 parts by mass with respect to 100 parts by mass of the raw rubber, and in the case of organic peroxide, the amount of the cross-linking agent is 100 parts by mass of the raw rubber. .5 to 8 parts by mass.

  Antiaging agents include amine-based, quinoline-based, hydroquinone derivatives, phenol-based, and phosphite-based agents. The anti-aging agent may be composed of a single species or a plurality of species. The amount of the anti-aging agent is, for example, 0 to 8 parts by mass with respect to 100 parts by mass of the raw rubber.

  Examples of the softener include petroleum softeners, mineral oil softeners such as paraffin wax, castor oil, cottonseed oil, sesame oil, rapeseed oil, soybean oil, palm oil, palm oil, fallen raw oil, waxy wax, rosin And vegetable oil-based softeners such as pine oil. The softener may be composed of a single species or a plurality of species. The amount of the softener other than the petroleum softener is 2 to 30 parts by mass with respect to 100 parts by mass of the raw rubber.

  Short fibers 16 may be blended in the rubber composition forming the compressed rubber layer 11. In that case, it is preferable that the short fiber 16 is provided so as to be oriented in the belt width direction, and a part of the short fiber 16 is exposed and protrudes from the surface of the V rib 15.

  Examples of the short fibers 16 include nylon short fibers, vinylon short fibers, aramid short fibers, polyester short fibers, and cotton short fibers. The short fiber 16 is obtained by, for example, cutting a long fiber that has been subjected to an adhesion treatment to be heated after being immersed in a resorcin / formalin / latex aqueous solution (hereinafter referred to as “RFL aqueous solution”) into a predetermined length along the length direction. Manufactured. For example, the short fibers 16 have a length of 0.2 to 5.0 mm and a fiber diameter of 10 to 50 μm. The amount of the short fiber 16 is 3 to 50 parts by mass with respect to 100 parts by mass of the raw rubber. In addition, the structure by which the short fiber 16 was not planted in the rubber composition, and the short fiber was planted on the V rib 15 surface may be sufficient.

  In the V-ribbed belt B according to the present embodiment, the moisture content of the compressed rubber layer 11 which is a pulley contact portion is 0.70% by mass or more, preferably 0.70 to 3.0% by mass, 0.70 More preferably, it is -1.5 mass%. Thus, in the V-ribbed belt B according to the present embodiment, the compressed rubber layer 11 includes a layered silicate and has a moisture content of 0.70% by mass or more, including when it is wet. Excellent noise suppression effect can be obtained.

  The adhesive rubber layer 12 is formed in a band shape having a horizontally long cross section, and is formed to have a thickness of 1.0 to 2.5 mm, for example. The back rubber layer 13 is also formed in a band shape having a horizontally long cross section, and has a thickness of 0.4 to 0.8 mm, for example. The adhesive rubber layer 12 and the back rubber layer 13 are formed of a rubber composition obtained by heating and pressurizing an uncrosslinked rubber composition in which various compounding agents are blended and mixed with raw rubber and then crosslinking with a crosslinking agent. . In addition, instead of the back rubber layer 13, for example, a reinforcing cloth made of a woven fabric, a knitted fabric, a non-woven fabric, or the like formed of yarn such as cotton, polyamide fiber, polyester fiber, or aramid fiber may be provided.

  Examples of the raw rubber for the rubber composition forming the adhesive rubber layer 12 and the back rubber layer 13 include ethylene-α-olefin elastomer, chloroprene rubber (CR), chlorosulfonated polyethylene rubber (CSM), hydrogenated acrylonitrile rubber ( H-NBR) and the like. The raw rubber for the adhesive rubber layer 12 is preferably the same as the raw rubber for the compressed rubber layer 11.

  Examples of the compounding agent include a reinforcing material such as carbon black, a vulcanization accelerator, a crosslinking agent, an anti-aging agent, a softening agent and the like, as in the case of the compressed rubber layer 11.

  The compressed rubber layer 11, the adhesive rubber layer 12, and the back rubber layer 13 may be formed of a rubber composition having a different composition, or may be formed of a rubber composition having the same composition.

  The core wire 14 is composed of twisted yarns such as polyester fiber (PET), polyethylene naphthalate fiber (PEN), aramid fiber, and vinylon fiber. The core wire 14 is subjected to an adhesive treatment that is heated after being immersed in an RFL aqueous solution before molding and / or an adhesive treatment that is dried after being immersed in rubber paste in order to impart adhesion to the V-ribbed belt main body 10. .

  The V-ribbed belt B according to the present embodiment can be manufactured by putting a post-molding V-ribbed belt molded by a known method in a steam atmosphere or water for a predetermined time. The time in the water vapor atmosphere or water is preferably 8 hours or more, and more preferably 12 to 24 hours.

  The V-ribbed belt B according to the present embodiment is used by being wound around, for example, a crankshaft pulley, a power steering pulley, an AC generator pulley, a tensioner pulley, a water pump pulley, and an air conditioner pulley in an accessory drive belt transmission.

  FIG. 2 shows a pulley layout of an auxiliary drive belt transmission device 20 for an automobile using a V-ribbed belt B according to the present embodiment. The accessory drive belt transmission device 20 is of a serpentine drive type in which a V-ribbed belt B is wound around six pulleys of four rib pulleys and two flat pulleys to transmit power.

  This auxiliary machine drive belt transmission 20 includes a power steering pulley 21 at the uppermost position, an AC generator pulley 22 arranged below the power steering pulley 21, and a flat pulley tensioner pulley arranged below the left side of the power steering pulley 21. 23, a flat water pump pulley 24 disposed below the tensioner pulley 23, a crankshaft pulley 25 disposed on the lower left side of the tensioner pulley 23, and a lower right side of the crankshaft pulley 25. And an air conditioner pulley 26. Among these, all except the tensioner pulley 23 and the water pump pulley 24 which are flat pulleys are rib pulleys. These rib pulleys and flat pulleys are made of, for example, a metal press-worked product, a casting, a resin molded product such as a nylon resin, a phenol resin, and the diameter of the pulley is 50 to 150 mm.

  In this auxiliary machine drive belt transmission 20, after the V-ribbed belt B is wound around the power steering pulley 21 so that the V-rib 15 side comes into contact, and then around the tensioner pulley 23 so that the back surface of the belt comes into contact. Further, the crankshaft pulley 25 and the air conditioner pulley 26 are wound in order so that the V rib 15 side contacts, and further, the water pump pulley 24 is wound so that the back surface of the belt contacts, and the V rib 15 side contacts. Is wound around the AC generator pulley 22 and finally returned to the power steering pulley 21. The belt span length, which is the length of the V-ribbed belt B spanned between the pulleys, is, for example, 50 to 300 mm. Misalignment that can occur between pulleys is 0-2 °.

  In this embodiment, the V-ribbed belt B is used. However, the present invention is not limited to this, and a low-edge type V-belt may be used.

[Test Evaluation 1]
(V-ribbed belt)
V-ribbed belts after molding of Examples 1 to 6 and Comparative Examples 1 to 4 below were produced. The rubber composition of each compressed rubber layer is also shown in Table 1.

<Example 1>
EPDM (trade name: EPT3045 manufactured by Mitsui Chemicals) is used as a raw rubber, and 60 parts by weight of HAF carbon black (trade name: Seast SO manufactured by Tokai Carbon Co., Ltd.) and montmorillonite (manufactured by Hojun Co., Ltd.) with respect to 100 parts by weight of the raw rubber. Name: Wengel HVP, swelling power 44 ml / 2 g, cation exchange capacity 96 meg / 100 g) 30 parts by mass, zinc oxide (manufactured by Sakai Chemical Industry Co., Ltd., trade name: Zinc Hana 2), 5 parts by mass, anti-aging agent (Emerging Ouchi) Product name: NOCRACK MB) 2 parts by mass, paraffinic oil (product name: Diana Process Oil PS-90) 10 parts by mass, sulfur (product name: Oil Sulfer) 2.3 by paraffinic oil Part by mass, vulcanization accelerator (trade name: TET, EZ, MSA manufactured by Sanshin Chemical Co., Ltd.) 1.4 parts by mass, and short fiber (product name: Leo Asahi Kasei) 66, to obtain a fiber length 1mm) 30 parts by mass were blended and kneaded for about 5 minutes in an internal kneader with uncrosslinked rubber composition. A molded V-ribbed belt in which a compressed rubber layer was formed using this uncrosslinked rubber composition was defined as Example 1.

  The adhesive rubber layer and the back rubber layer are composed of another EPDM rubber composition, and the core is composed of a twisted yarn made of polyethylene terephthalate fiber (PET). The belt circumference is 1200 mm, the belt width is 21.36 mm, and the belt. The thickness was 4.3 mm, and the number of ribs was six.

<Example 2>
Implemented except that montmorillonite-containing material (trade name: Super Clay, swelling power 24 ml / 2 g, cation exchange capacity 65 meg / 100 g) made of montmorillonite instead of montmorillonite was blended with 30 parts by mass with respect to 100 parts by mass of raw rubber. An uncrosslinked rubber composition having the same structure as that of Example 1 was obtained. A post-molded V-ribbed belt similar to Example 1 in which a compressed rubber layer was formed using this uncrosslinked rubber composition was defined as Example 2.

<Example 3>
Example except that 30 parts by mass of montmorillonite-containing material (trade name: Hodaka, swelling height 16 ml / 2 g, cation exchange capacity 86 meg / 100 g) was mixed with 100 parts by mass of the raw rubber instead of montmorillonite. An uncrosslinked rubber composition having the same structure as that of No. 1 was obtained. A post-molded V-ribbed belt similar to Example 1 in which a compressed rubber layer was formed using this uncrosslinked rubber composition was designated as Example 3.

<Example 4>
An uncrosslinked rubber composition having the same structure as that of Example 1 was obtained except that the blending amount of montmorillonite was 5 parts by mass with respect to 100 parts by mass of the raw rubber. A post-molded V-ribbed belt similar to Example 1 in which a compressed rubber layer was formed using this uncrosslinked rubber composition was designated as Example 4.

<Example 5>
An uncrosslinked rubber composition having the same configuration as that of Example 1 was obtained except that the blending amount of montmorillonite was 10 parts by mass with respect to 100 parts by mass of the raw rubber. A molded V-ribbed belt similar to Example 1 in which a compressed rubber layer was formed using this uncrosslinked rubber composition was designated as Example 5.

<Example 6>
Except that the blending amount of HAF carbon black is 45 parts by weight with respect to 100 parts by weight of the raw rubber and the blending amount of montmorillonite is 80 parts by weight with respect to 100 parts by weight of the raw rubber, it has the same configuration as that of Example 1. An uncrosslinked rubber composition was obtained. A post-molded V-ribbed belt similar to Example 1 in which a compressed rubber layer was formed using this uncrosslinked rubber composition was designated as Example 6.

<Comparative Example 1>
An uncrosslinked rubber composition having the same structure as that of Example 1 was obtained except that montmorillonite was not blended. And the after-molding V ribbed belt similar to Example 1 which formed the compression rubber layer using this uncrosslinked rubber composition was made into the comparative example 1.

<Comparative example 2>
Example except that 30 parts by mass of montmorillonite-containing material (trade name: Haruna, swellability 10 ml / 2 g, cation exchange capacity 69 meg / 100 g) was mixed with 100 parts by mass of the raw rubber instead of montmorillonite. An uncrosslinked rubber composition having the same structure as that of No. 1 was obtained. Then, a post-molded V-ribbed belt similar to Example 1 in which a compressed rubber layer was formed using this uncrosslinked rubber composition was used as Comparative Example 2.

<Comparative Example 3>
An uncrosslinked rubber composition having the same configuration as that of Example 1 except that 30 parts by mass of calcium carbonate (trade name: Shiraka Hana CC, manufactured by Shiroishi Calcium Industry Co., Ltd.) is blended with 100 parts by mass of the raw rubber instead of montmorillonite. Got. And the after-molding V ribbed belt similar to Example 1 which formed the compression rubber layer using this uncrosslinked rubber composition was made into the comparative example 3.

<Comparative example 4>
An uncrosslinked rubber having the same configuration as that of Example 1 except that 10 parts by mass of a surfactant (trade name: Afflux 54, manufactured by Rhein Chemie Japan Co., Ltd.) is blended with 100 parts by mass of the raw rubber instead of montmorillonite. A composition was obtained. And the after-molding V ribbed belt similar to Example 1 which formed the compression rubber layer using this uncrosslinked rubber composition was made into the comparative example 4.

(Test evaluation method)
<Moisture content of the compressed rubber layer of the V-ribbed belt after molding>
About the test piece of the compression rubber layer cut out from each of Examples 1-6 and Comparative Examples 1-4, the mass of a test piece was measured in advance (W0 (0.040-0.060g)), and with a moisture vaporizer. After heating at 120 ° C. for 20 minutes, the amount of water contained in the volatile components was measured with a Karl Fischer moisture meter (m). Then, (m / W0) × 100 (mass%) was taken as the moisture content of the compressed rubber layer of the V-ribbed belt after molding.

<Water absorption evaluation>
About the test piece of the compression rubber layer cut out from each of Example 1, Example 6, Comparative Example 1, Comparative Example 3, and Comparative Example 4, the mass after performing water immersion processing for 12 hours based on JIS K6258 Was measured (W12). Then, ((W12−W0) / W0) × 100 (%) was defined as the mass change rate.

  About the test piece of the compression rubber layer cut out from each of Examples 1 to 6 and Comparative Example 1, Comparative Example 2, and Comparative Example 4, based on JIS K6258, the mass after performing water immersion processing for 24 hours. Measurement (W24), and the mass change rate was calculated in the same manner as described above.

<Evaluation of abnormal noise when wet>
In the belt running test evaluation for evaluating the wet noise, in Examples 1 and 6 and Comparative Examples 1 and 4, the V-ribbed belt after molding which was not subjected to water immersion processing, V which was subjected to water immersion processing for 12 hours About the ribbed belt and the V-ribbed belt subjected to the water immersion process for 24 hours, and the comparative example 3 for the V-ribbed belt subjected to the water immersion process for 12 hours. Further, in Examples 2 to 6 and Comparative Example 2, 24 hours Each of the V-ribbed belts subjected to water immersion processing was performed.

  FIG. 3 shows a pulley layout of the belt running test machine 30 for evaluating abnormal noise when wet.

  The belt running test machine 30 for evaluating abnormal noise when wet is provided with a drive pulley 31 that is a rib pulley having a pulley diameter of 140 mm, and a first driven pulley 32 that is a rib pulley having a pulley diameter of 75 mm is provided to the right of the drive pulley 31. A second driven pulley 33, which is a rib pulley having a pulley diameter of 50 mm, is provided above the first driven pulley 32 and diagonally right above the driving pulley 31. Further, the driving pulley 31 and the second driven pulley 33 An idler pulley 34, which is a flat pulley having a pulley diameter of 75 mm, is provided in the middle. In this wet running noise evaluation belt running test machine 30, the V-rib side of the evaluation belt B is in contact with the driving pulley 31 which is a rib pulley, the first and second driven pulleys 32 and 33, and the back side is a flat pulley. It is configured to be wound around in contact with a certain idler pulley 34.

  The evaluation belt B is set on the belt running test machine 30 for evaluating abnormal noise when wet, and pulley positioning is performed so that a belt tension of 49 N per rib is applied, and the pulley is attached to the second driven pulley 33. A resistance is applied to the alternator so that a current of 60 A flows, and the drive pulley 31 is rotated at a rotation speed of 800 rpm at room temperature, and the evaluation belt B enters the drive pulley 31 at a portion of the evaluation belt B toward the V-rib side of the evaluation belt B every minute. Water was added dropwise at a rate of 1000 ml.

  Abnormal noise generation during belt running: A: No abnormal noise is generated. B: Almost no abnormal noise is generated. C: Abnormal noise occurs rarely. D: An abnormal noise of 75 dB or more and less than 82 dB is generated. E: An abnormal noise of 82 dB or more is generated. It was evaluated in five stages.

<Abrasion resistance evaluation>
Belt running test evaluations for wear resistance evaluation were conducted in Examples 1 and 6 and Comparative Examples 1 and 4, respectively, a V-ribbed belt subjected to 12 hours of water immersion and a V-ribbed belt subjected to 24 hours of water immersion. In Comparative Example 3, a V-ribbed belt subjected to water immersion for 12 hours was used, and in Examples 2 to 6 and Comparative Example 2, a V-ribbed belt subjected to water immersion for 24 hours was used.

  FIG. 4 shows a pulley layout of the belt running test machine 40 for evaluating wear.

  The wear test belt running test machine 40 includes a drive pulley 41 and a driven pulley 42 that are rib pulleys having a pulley diameter of 60 mm, which are arranged on the left and right sides. The wear evaluation belt running test machine 40 is configured such that the V-rib side of the evaluation belt B is wound around the drive pulley 41 and the driven pulley 42 that are rib pulleys.

  The evaluation belt B is set on the wear evaluation belt running test machine 40, a rotational load of 3.82 kW is applied to the driven pulley 42, and a dead weight of 1177N is applied to the side so that the belt tension is applied, Under normal temperature, the driving pulley 41 was rotated at a rotational speed of 3500 rpm and the belt was run for 24 hours.

  Then, the surface of the pulley after running the belt was visually observed and evaluated as ○ when there was adhesive wear and × when there was not.

(Test evaluation results)
Table 2 shows the test results.

  The moisture content of the compressed rubber layer of the V-ribbed belt after molding was 0.38% by mass in Example 1, 0.33% by mass in Example 2, 0.27% by mass in Example 3, and 0.2% in Example 4. 26 mass%, Example 5 is 0.31 mass%, Example 6 is 0.90 mass%, Comparative Example 1 is 0.21 mass%, Comparative Example 2 is 0.24 mass%, and Comparative Example 3 is 0.21 mass% and the comparative example 4 were 0.23 mass%.

  The mass change rate of the compressed rubber layer when subjected to water immersion processing for 12 hours is 0.52% in Example 1, 0.95% by mass in Example 6, and 0.08% in Comparative Example 1, compared. Example 3 was 0.18% and Comparative Example 4 was 0.15%.

  The mass change rate of the compressed rubber layer when subjected to water immersion treatment for 24 hours is 0.89% in Example 1, 0.62% in Example 2, 0.51% in Example 3, and Example 4 0.52%, Example 5 0.63%, and Example 6 1.65%, and Comparative Example 1 0.30%, Comparative Example 2 0.39%, and Comparative Example 4 0 32%.

  From the mass (W0) before the test of the test piece of the compressed rubber layer of the V-ribbed belt after the molding, the water content (m), and the mass (W12) after the water immersion process ((m + (W12−W0)) / The water content of the compressed rubber layer of the V-ribbed belt subjected to the water immersion process for 12 hours calculated from W12) × 100 (mass%) is 0.90 mass% in Example 1 and 1.85 in Example 6. % By mass, Comparative Example 1 is 0.29% by mass, Comparative Example 3 is 0.39% by mass, and Comparative Example 4 is 0.38% by mass. Further, the moisture content of the compressed rubber layer of the V-ribbed belt subjected to the water immersion process for 24 hours is 1.26% by mass in Example 1, 0.94% by mass in Example 2, and 0.78% by mass in Example 3. %, Example 4 is 0.78% by mass, Example 5 is 0.94% by mass, Example 6 is 2.55% by mass, Comparative Example 1 is 0.51% by mass, and Comparative Example 2 is 0.2% by mass. 63 mass% and the comparative example 4 are 0.55 mass%.

  Examples 1 and 6 were C, and Comparative Example 1 was E, and Comparative Example 4 was B. As for the abnormal noise evaluation of the V-ribbed belt subjected to water immersion processing for 12 hours, Example 1 is B, Example 6 is A, Comparative Example 1 is E, Comparative Example 3 is D, and Comparative Example 4 is B. The abnormal noise evaluation of the V-ribbed belt subjected to the water immersion process for 24 hours is as follows. Example 1 is A, Example 2 is B, Example 3 is B, Example 4 is C, Example 5 is B, And Example 6 was A, and Comparative Example 1 was D, Comparative Example 2 was D, and Comparative Example 4 was B.

  The abrasion resistance evaluation of the V-ribbed belt subjected to the water immersion process for 12 hours was ○ in Example 1, Comparative Example 1 and Comparative Example 2, Δ in Example 6, and × in Comparative Example 4. The abrasion resistance evaluation of the V-ribbed belt subjected to the water immersion process for 24 hours was ○ in Examples 1 to 5 and Comparative Examples 1 to 3, Δ in Example 6, and × in Comparative Example 2.

  From the above results, in Examples 1 to 6 in which the compressed rubber layer contains montmorillonite which is a layered silicate, the moisture content of the compressed rubber layer of the V-ribbed belt subjected to any water immersion process for 12 hours and 24 hours is also shown. It is 0.78% by mass or more, and it can be seen that the abnormal noise evaluation during water immersion after water immersion processing is A to C, and the wear resistance evaluation is ○ to Δ.

  On the other hand, in Comparative Examples 1 to 3, the moisture content of the V-ribbed belt subjected to water immersion processing for 12 hours and 24 hours is 0.63% or less, and the difference in water after the water immersion processing is different. In the sound evaluation, although Comparative Example 4 is B, all of Comparative Examples 1 to 3 are D, while the abrasion resistance evaluation is Comparative Example 1 is ○, but Comparative Example 4 is ×. I understand that there is.

  Further, when Examples 1 and 6 are compared with Comparative Examples 1 and 4, in the former, the effect of suppressing abnormal noise when wet is improved by performing water immersion and absorbing water, whereas in the latter, It turns out that the effect improvement is not recognized. This is presumably because the layered silicate exposed on the pulley contact surface swells by retaining water between the layers, thereby stabilizing the friction coefficient of the pulley contact surface.

[Test evaluation 2]
(V-ribbed belt)
V-ribbed belts after molding of Examples 7 to 10 and Comparative Examples 5 to 9 below were produced. The rubber composition of each compressed rubber layer is also shown in Table 3.

<Example 7>
EPDM (trade name: EPT3045 manufactured by Mitsui Chemicals) is used as a raw rubber, and 60 parts by weight of HAF carbon black (trade name: Seast SO manufactured by Tokai Carbon Co., Ltd.) and montmorillonite (manufactured by Hojun Co., Ltd.) with respect to 100 parts by weight of the raw rubber. Name: Bengel A, swelling power 46 ml / 2 g, cation exchange capacity 94 meg / 100 g) 30 parts by mass, zinc oxide (manufactured by Sakai Chemical Industry Co., Ltd., trade name: Zinc Hana 2), 5 parts by mass, anti-aging agent (Emerging Ouchi) Product name: NOCRACK MB) 2 parts by mass, paraffinic oil (product name: Diana Process Oil PS-90) 10 parts by mass, sulfur (product name: Oil Sulfer) 2.3 by paraffinic oil Part by mass, vulcanization accelerator (trade name: TET, EZ, MSA manufactured by Sanshin Chemical Co., Ltd.) 1.4 parts by mass, and short fiber (product name: manufactured by Asahi Kasei Co., Ltd .: Leona 6) To give a fiber length 1mm) 30 parts by mass were blended and kneaded for about 5 minutes in an internal kneader with uncrosslinked rubber composition. A molded V-ribbed belt in which a compressed rubber layer was formed using this uncrosslinked rubber composition was designated as Example 7. This Example 7 differs from Example 1 of Test Evaluation 1 in the part number of montmorillonite.

  The adhesive rubber layer and the back rubber layer are composed of another EPDM rubber composition, and the core is composed of a twisted yarn made of polyethylene terephthalate fiber (PET). The belt circumference is 1200 mm, the belt width is 21.36 mm, and the belt. The thickness was 4.3 mm, and the number of ribs was six.

<Example 8>
An uncrosslinked rubber composition having the same configuration as that of Example 5 except that 30 parts by mass of hectorite (trade name: Smecton HE, manufactured by Kunimine Industries Co., Ltd.) is mixed with 100 parts by mass of the raw rubber instead of montmorillonite. Obtained. A molded V-ribbed belt similar to that of Example 7 in which a compressed rubber layer was formed using this uncrosslinked rubber composition was designated as Example 8.

<Example 9>
An uncrosslinked rubber composition having the same configuration as that of Example 7 was obtained except that 30 parts by mass of talc (trade name: Simgon manufactured by Nippon Talc Co., Ltd.) was blended with 100 parts by mass of the raw rubber instead of montmorillonite. . A post-molded V-ribbed belt similar to Example 7 in which a compressed rubber layer was formed using this uncrosslinked rubber composition was designated as Example 9.

<Example 10>
An uncrosslinked rubber having the same structure as that of Example 7 except that swellable mica (trade name: Somasif ME-100, manufactured by Coop Chemical Co., Ltd.) instead of montmorillonite was blended in 30 parts by mass with respect to 100 parts by mass of the raw rubber. A composition was obtained. A molded V-ribbed belt similar to Example 7 in which a compressed rubber layer was formed using this uncrosslinked rubber composition was designated as Example 10.

<Comparative Example 5>
An uncrosslinked rubber composition having the same structure as that of Example 7 was obtained except that montmorillonite was not blended. Then, a V-ribbed belt after molding similar to Example 5 in which a compressed rubber layer was formed using this uncrosslinked rubber composition was used as Comparative Example 5. The comparative example 5 is a lot difference of the comparative example 1 of the test evaluation 1.

<Comparative Example 6>
An uncrosslinked rubber composition having the same structure as that of Example 7 was obtained except that 30 parts by mass of halloysite (trade name: Hallysite nanoclay manufactured by Aldrich) was blended with 100 parts by mass of the raw rubber instead of montmorillonite. . And the after-molding V ribbed belt similar to Example 7 which formed the compression rubber layer using this uncrosslinked rubber composition was made into the comparative example 6.

<Comparative Example 7>
Non-swelling mica (trade name: Micromica MK-200, manufactured by Coop Chemical Co., Ltd.) instead of montmorillonite was blended in an amount of 30 parts by mass with respect to 100 parts by mass of the raw rubber. A crosslinked rubber composition was obtained. And the after-molding V ribbed belt similar to Example 7 which formed the compression rubber layer using this uncrosslinked rubber composition was made into Comparative Example 7.

<Comparative Example 8>
An uncrosslinked rubber composition having the same configuration as that of Example 7 except that 30 parts by mass of calcium carbonate (trade name: Shiraka Hana CC, manufactured by Shiroishi Calcium Industry Co., Ltd.) is blended with 100 parts by mass of the raw rubber instead of montmorillonite. Got. A post-molded V-ribbed belt similar to Example 7 in which a compressed rubber layer was formed using this uncrosslinked rubber composition was used as Comparative Example 8. The comparative example 5 is a lot difference of the comparative example 4 of the test evaluation 1.

<Comparative Example 9>
An uncrosslinked rubber having the same configuration as that of Example 7 except that 10 parts by mass of a surfactant (trade name: Areflux 54, manufactured by Rhein Chemie Japan) is blended with 100 parts by mass of the raw rubber instead of montmorillonite. A composition was obtained. A post-molded V-ribbed belt similar to Example 7 in which a compressed rubber layer was formed using this uncrosslinked rubber composition was used as Comparative Example 9. The comparative example 9 is a lot difference from the comparative example 2 of the test evaluation 1.

(Test evaluation method)
<Moisture content of V-ribbed belt after molding>
About each of Examples 7-10 and Comparative Examples 5-9, it carried out similarly to the test evaluation 1, and calculated | required the moisture content of the compression rubber layer of a V-ribbed belt after shaping | molding.

<Water absorption evaluation>
About each of Examples 7-10 and Comparative Examples 5-9, it carried out similarly to the test evaluation 1, and calculated | required the mass change rate after giving the water immersion process for 24 hours of the compression rubber layer of the V-ribbed belt after shaping | molding.

<X-ray diffraction measurement evaluation>
About the post-molding V-ribbed belt that was not subjected to the water immersion process of each of Examples 7 to 10 and Comparative Examples 5 to 9 and the V-ribbed belt that was subjected to the water immersion process for 24 hours, a plurality of V-ribs along the length direction A sample obtained by cutting out and arranging them in parallel was used as a test piece, and a detection peak at a measurement range of 2θ = 0.2 to 15 ° in the X-ray diffraction measurement was measured with a powder X-ray diffractometer Ultima III manufactured by Rigaku Corporation.

<Evaluation of abnormal noise when wet>
For each of Examples 7 to 10 and Comparative Examples 5 to 9 which were not subjected to the water immersion process, the molded V-ribbed belt and the V-ribbed belt which was subjected to the water immersion process for 24 hours were subjected to abnormal noise when wet as in Test Evaluation 1. Belt running test evaluation for evaluation was performed.

<Abrasion resistance evaluation>
For each of Examples 7 to 10 and Comparative Examples 5 to 9 which were not subjected to the water immersion process, the molded V-ribbed belt and the V-ribbed belt which was subjected to the water immersion process for 24 hours were evaluated for wear resistance in the same manner as in Test Evaluation 1. The belt running test evaluation was performed.

(Test evaluation results)
Table 4 shows the test results.

  The moisture content of the compressed rubber layer of the V-ribbed belt after molding was 0.40% by mass in Example 7, 0.41% by mass in Example 8, 0.29% by mass in Example 9, and 0 in Example 10. .31% by mass, and Comparative Example 5 is 0.21% by mass, Comparative Example 6 is 0.27% by mass, Comparative Example 7 is 0.29% by mass, Comparative Example 8 is 0.21% by mass, and Comparative Example 9 Was 0.23% by mass.

  The mass change rate of the compressed rubber layer when subjected to water immersion for 24 hours is 0.89% in Example 7, 0.92% in Example 8, 0.58% in Example 9, and Example. 10 is 0.78%, and Comparative Example 5 is 0.30%, Comparative Example 6 is 0.38%, Comparative Example 7 is 0.34%, Comparative Example 8 is 0.39%, and Comparative Example 9 is 0. 32%.

  The moisture content of the V-ribbed belt subjected to water immersion processing for 24 hours calculated from the moisture content of the compressed rubber layer of the molded V-ribbed belt and the mass change rate after immersion processing is 1.28% by mass in Example 7. Example 8 was 1.32% by mass, Example 9 was 0.86% by mass, Example 10 was 1.08% by mass, Comparative Example 5 was 0.51% by mass, and Comparative Example 6 was 0.65%. % By mass, Comparative Example 7 is 0.63% by mass, Comparative Example 8 is 0.60% by mass, and Comparative Example 9 is 0.55% by mass.

  As for the abnormal noise evaluation of the V-ribbed belt after molding without water immersion processing, Example 7 is B, Example 8 is B, Example 9 is C, Example 10 is C, and Comparative Example 5 is E, Comparative Example 6 was C, Comparative Example 7 was D, Comparative Example 8 was D, and Comparative Example 9 was C. As for the abnormal noise evaluation of the V-ribbed belt subjected to the water immersion processing for 24 hours, Example 7 is A, Example 8 is A, Example 9 is B, Example 10 is A, and Comparative Example 5 is E, Comparative Example 6 was C, Comparative Example 7 was D, Comparative Example 8 was D, and Comparative Example 9 was C.

  The abrasion resistance evaluation of the post-molded V-ribbed belt that was not subjected to water immersion processing was ○ in Examples 7 to 10 and Comparative Examples 5 to 8, and × in Comparative Example 9. As for the abrasion resistance evaluation of the V-ribbed belt subjected to the water immersion process for 24 hours, Examples 7 to 10 and Comparative Examples 5 to 8 were ○, and Comparative Example 9 was ×.

  From the above results, in Examples 7 to 10 in which a layered silicate was contained in the compressed rubber layer, the water content of the compressed rubber layer of the V-ribbed belt subjected to water immersion processing was 0.86% by mass or more, and water The X-ray diffraction peak detection angle after immersion processing is 5.40 to 8.70 °, and the evaluation of abnormal noise when wet after water immersion processing is A or B, and the wear resistance evaluation is any It turns out that it is ○.

  On the other hand, in Comparative Examples 5 to 9, the water content of the compressed rubber layer of the V-ribbed belt subjected to the water immersion process is 0.65% by mass or less, and the X-ray diffraction peak detection angle after the water immersion process is 8 .60 to 12.3 °, and the abnormal noise evaluation during water immersion after water immersion processing is C or D, and the abrasion resistance evaluation is Comparative Example 5-8, where Comparative Example 5 is ○ It can be seen that 9 is x.

  Moreover, when Examples 7-10 are compared with Comparative Examples 5-9, as in the case of Test Evaluation 1, in the former, the effect of suppressing abnormal noise when wet is improved by absorbing water by water immersion processing. On the other hand, it can be seen that the latter does not improve the effect.

[Test Evaluation 3]
(V-ribbed belt)
V-ribbed belts after molding of Example 11 and Comparative Example 10 below were produced. The rubber composition of each compressed rubber layer is also shown in Table 5.

<Example 11>
EPDM (trade name: EPT3045 manufactured by Mitsui Chemicals) is used as a raw rubber, and 60 parts by weight of HAF carbon black (trade name: Seast SO manufactured by Tokai Carbon Co., Ltd.) and montmorillonite (manufactured by Hojun Co., Ltd.) with respect to 100 parts by weight of the raw rubber. Name: 30 parts by weight of Bengel A), 5 parts by weight of zinc oxide (manufactured by Sakai Chemical Industry Co., Ltd., trade name: Zinc Hana 2), 1 part by weight of stearic acid (trade name: manufactured by NOF Corporation, bead stearic acid soot), anti-aging 2 parts by weight of agent (trade name: Nocrack MB, manufactured by Ouchi Shinsei Chemical Co., Ltd.), 10 parts by weight of paraffinic oil (trade name: Diana Process Oil PS-90, manufactured by Idemitsu Kosan Co., Ltd., trade name: oil, manufactured by Hosoi Chemical Co., Ltd.) Sulfur) 2.3 parts by mass, vulcanization accelerator (trade name: EP-150, manufactured by Ouchi Shinsei Chemical Co., Ltd.), and short fibers (trade name: Leona 66, manufactured by Asahi Kasei Co., Ltd.) (Steel length 1 mm) 30 parts by mass were blended and kneaded for about 5 minutes in a closed kneader to obtain an uncrosslinked rubber composition. A molded V-ribbed belt in which a compressed rubber layer was formed using this uncrosslinked rubber composition was designated as Example 11.

  The adhesive rubber layer and the back rubber layer are composed of another EPDM rubber composition, and the core is composed of a twisted yarn made of polyethylene terephthalate fiber (PET). The belt circumference is 1200 mm, the belt width is 21.36 mm, and the belt. The thickness was 4.3 mm, and the number of ribs was six.

<Comparative Example 10>
An uncrosslinked rubber composition having the same structure as that of Example 9 was obtained except that montmorillonite was not blended. A post-molded V-ribbed belt similar to Example 9 in which a compressed rubber layer was formed using this uncrosslinked rubber composition was used as Comparative Example 10.

(Test evaluation method)
<Moisture content of the compressed rubber layer of the V-ribbed belt after molding>
For each of Example 11 and Comparative Example 10, the moisture content of the compressed rubber layer of the V-ribbed belt after molding was determined in the same manner as in Test Evaluation 1.

<Belt water absorption evaluation>
For each of Example 11 and Comparative Example 10, the rate of mass change after the 24-hour water immersion process of the compressed rubber layer of the V-ribbed belt after molding was determined in the same manner as in Test Evaluation 1.

<Area share of layered silicate>
For each of the post-molded V-ribbed belts that were not subjected to the water immersion process of Example 11 and Comparative Example 10, and the V-ribbed belts that were subjected to the water immersion process for 24 hours of Example 9 and Comparative Example 10, respectively, The area occupancy of the layered silicate on the surface of the V-ribs was measured at 300 times magnification using a scanning electron microscope (scanning electron microscope S-48209 manufactured by Hitachi High-Technologies Corporation). It calculated | required by calculating the area ratio of the bright spot of Si element in the mapping image of Si element using apparatus EMAX EX-250).

<Evaluation of abnormal noise when wet>
For each of the molded V-ribbed belts that were not subjected to the water immersion process of Example 11 and Comparative Example 10 and the V-ribbed belts that were subjected to the 24-hour water immersion process of Example 11 and Comparative Example 10, respectively, test evaluation 1 and Similarly, a belt running test evaluation for evaluating abnormal noise when wet was performed.

<Abrasion resistance evaluation>
For the post-molded V-ribbed belts that were not subjected to the water immersion processing in Example 11 and Comparative Example 10, belt running test evaluation for wear resistance evaluation was performed in the same manner as in Test Evaluation 1.

(Test evaluation results)
Table 6 shows the test results.

  The moisture content of the compressed rubber layer of the V-ribbed belt after molding was 0.39% by mass in Example 11 and 0.22% by mass in Comparative Example 10.

  The mass change rate of the compressed rubber layer when subjected to water immersion treatment for 24 hours was 0.88% in Example 11 and 0.31% in Comparative Example 10.

  The moisture content of the V-ribbed belt subjected to water immersion processing for 24 hours calculated from the moisture content of the compressed rubber layer of the molded V-ribbed belt and the mass change rate after immersion processing is 1.26% by mass in Example 11. And the comparative example 10 was 0.53 mass%.

  The area occupancy of the layered silicate in the compressed rubber layer of the V-ribbed belt after molding was 12% in Example 11. The area occupancy ratio of the layered silicate in the compressed rubber layer of the V-ribbed belt subjected to the water immersion process for 24 hours was 16% in Example 11.

  As for the abnormal noise evaluation of the V-ribbed belt after molding, which was not subjected to water immersion processing, Example B was B and Comparative Example 10 was E. As for the abnormal noise evaluation of the V-ribbed belt subjected to the water immersion process for 24 hours, A in Example 11 and E in Comparative Example 10.

  As for the abrasion resistance evaluation of the post-molding V-ribbed belt that was not subjected to water immersion processing, Example 11 and Comparative Example 10 were “good”.

  From the above results, in Example 11 in which the layered silicate was contained in the compressed rubber layer, the moisture content of the compressed rubber layer of the V-ribbed belt subjected to water immersion processing was 1.26% by mass, and in the compressed rubber layer It can be seen that the area occupancy ratio of the layered silicate is 16%, and the abnormal noise evaluation when wet after water immersion processing is A.

  On the other hand, in Comparative Example 10, the moisture content of the compressed rubber layer of the V-ribbed belt subjected to the water immersion process was 0.53% by mass, and no layered silicate was detected in the compressed rubber layer, and the water immersion It can be seen that the evaluation of abnormal noise when wet after processing is E.

  In addition, when Example 11 and Comparative Example 10 are compared, as in the case of Test Evaluations 1 and 2, in the former, the V-ribbed belt itself absorbs water, and the effect of suppressing abnormal noise during water is improved. It can be seen that the latter does not improve the effect.

  INDUSTRIAL APPLICABILITY The present invention is useful for a friction transmission belt in which a belt body is wound so as to come into contact with a pulley to transmit power and a method for manufacturing the same.

B V-ribbed belt (friction drive belt)
10 V-ribbed belt body 15 V-rib (pulley contact part)

Claims (8)

A friction transmission belt that is wound around the belt body so as to contact the pulley and transmits power;
At least a pulley contact portion of the belt body is a friction transmission belt formed of a rubber composition in which a layered silicate is blended with a raw rubber and a moisture content is 0.70% by mass or more. In the friction transmission belt according to claim 1,
A friction transmission belt in which the swelling force of the layered silicate is 20 ml / 2 g or more. In the friction transmission belt according to claim 1 or 2,
A friction transmission belt in which the cation exchange capacity of the layered silicate is 70 meg / 100 g or more. In the friction transmission belt according to any one of claims 1 to 3,
The rubber composition forming at least the pulley contact portion of the belt body is a friction transmission belt having a detection peak of 2θ = 9 ° or less in a measurement range of 2θ = 0.2-15 ° in X-ray diffraction measurement. The friction transmission belt according to any one of claims 1 to 4,
A friction transmission belt in which the area occupancy of the layered silicate exposed on the pulley contact surface of the belt body is 12% or more. In the friction transmission belt according to any one of claims 1 to 5,
A friction transmission belt, wherein the layered silicate contains montmorillonite. The friction transmission belt according to any one of claims 1 to 6,
The rubber composition for forming at least a pulley contact portion of the belt main body contains 10 to 80 parts by mass of the layered silicate with respect to 100 parts by mass of the raw rubber. In the manufacturing method of the friction transmission belt according to any one of claims 1 to 7,
At least a pulley contact portion of the belt body includes a step of putting a post-molding friction transmission belt formed of a rubber composition in which a raw material rubber is mixed with a layered silicate into a steam atmosphere or water for a predetermined time. A method for manufacturing a friction transmission belt.

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