JP2009068673A - Transmission belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission belt capable of extremely reducing a slip sound. <P>SOLUTION: This transmission belt has a surface layer in contact with a pulley when wound around the pulley, and is formed by including short fibers in the surface layer. The transmission belt is characterized in that the surface layer contains an urethane resin as a base material constituent; and, as the short fiber, at least one kind selected from a group comprising a para-type aramid fiber, a polyethylene terephthalate fiber, a super-high-molecular polyethylene fiber, a polypropylene fiber, a polyparaphenylenebenzobisoxazole fiber and a polyarylate is used. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a transmission belt that is wound so as to contact a pulley and transmits power.

2. Description of the Related Art Conventionally, as a means for transmitting rotational power of an engine, a motor, or the like, a method of providing pulleys on rotating shafts on a power source side and a rotating object side and spanning a transmission belt around each pulley has been widely used.
Such a transmission belt is known to cause a phenomenon called stick-slip when water adheres due to water exposure or condensation, and generates slip noise due to slip between the pulley and the pulley. It is known.
Such slip noise of the transmission belt causes the noise of the device, and particularly when used in an automobile, it causes indoor noise during operation. Therefore, various countermeasures have been conventionally studied.
As one of the countermeasures, a countermeasure has been proposed in which short fibers are contained in the surface layer of the belt in contact with the pulley in order to reduce friction.
Specifically, Patent Document 1 below proposes a transmission belt in which polyamide short fibers are contained in a rubber surface layer.
However, such a transmission belt has a problem that the effect of reducing slip noise is still not sufficient.

JP 2004-316787 A

  Therefore, in view of the above problems, an object of the present invention is to provide a transmission belt that can have extremely low slip noise.

As a result of diligent investigation focusing on the above-mentioned problems, the present inventors have found that a remarkable slip reduction effect is achieved by setting the base material component and short fibers of the surface layer to a predetermined one, and the present invention has been completed. It came to do.
That is, the present invention is a transmission belt having a surface layer that comes into contact with the pulley when wound on a pulley, and the surface layer includes short fibers,
The surface layer includes a urethane resin as a base material component, and the short fibers include para-aramid fibers, polyethylene terephthalate fibers, ultra-high molecular polyethylene fibers, polypropylene fibers, polyparaphenylene benzobisoxazole fibers, polyarylate. The present invention provides a transmission belt characterized in that at least one selected from the group consisting of fibers is used.
In such a transmission belt, urethane resin is included as a base material component of the surface layer, and as the short fiber, para-type aramid fiber, polyethylene terephthalate fiber, ultra-high molecular polyethylene fiber, polypropylene fiber, polyparaphenylene By using at least one selected from the group consisting of benzobisoxazole fibers and polyarylate fibers, slip noise can be extremely small.

In the present invention, the short fiber length is preferably 0.3 to 1.5 mm, and the short fiber L / D ratio (aspect ratio) is preferably 20 to 150.
In such a range, the slip noise can be reduced.
In addition, the length of these short fibers is obtained by calculating | requiring the average value of arbitrary 50 short fibers to be used.
Similarly, the L / D ratio is obtained by obtaining an average value of 50 arbitrary lines.

  Furthermore, in the present invention, it is preferable that the content of the short fibers in the surface layer is 10 to 60% by volume. In such a range, the slip noise can be reduced.

  As described above, the transmission belt of the present invention can have extremely low slip noise.

Embodiments of the present invention will be described below with reference to the drawings.
Examples of the transmission belt of the present invention include a V-ribbed belt and a V-belt that are used for transmitting engine rotation.
In FIG. 1, a preferred embodiment of a V-ribbed belt 1 is shown as a transmission belt of one embodiment.
The transmission belt 1 of the present embodiment is formed in an endless shape, and the belt cross section has a plurality of ribs 6 formed in a trapezoidal shape with a narrower width toward the inner peripheral side as shown in FIG. (Specifically, three) are formed continuously on the inner peripheral side.
A compression layer 5 as an inner rubber layer is formed on the inner peripheral side of the V-ribbed belt 1, that is, the inner side when wound around a pulley, and the adhesive layer 3 is formed on the outer peripheral side of the compression layer 5. A cover layer 2 that is the outermost layer of the V-ribbed belt 1 is formed on the outer peripheral side of the adhesive layer 3.
Furthermore, the power transmission belt of the present embodiment has a surface layer 7 that comes into contact with the pulley when wound around the pulley, on the inner side of the compression layer 5, and the surface layer 7 includes a base material component (surface layer 7 The resin component and the short fibers for reducing friction are included, the short fibers are mixed in the layer, and a part thereof is exposed from the surface.

  Examples of the short fibers include at least one selected from the group consisting of para-aramid fibers, polyethylene terephthalate fibers, ultra-high molecular weight polyethylene fibers, polypropylene fibers, polyparaphenylene benzobisoxazole fibers, and polyarylate fibers. These short fibers preferably have a tensile strength of 5 to 40 cN / dtex in terms of reducing friction in the surface layer 7 and reducing the amount of wear of the surface layer 7. In addition, about these short fibers, what is marketed can be used.

  Examples of the material of the para-type aramid fiber include polyamide whose molecular skeleton is aromatic (benzene ring), and in particular, a para-type whose molecular skeleton is linear. The para type is preferable in that it has high strength and excellent wear resistance, and therefore the transmission belt is less likely to be worn for a long time and slip noise is less likely to occur.

  Examples of the material of the polyethylene terephthalate fiber include polyethylene terephthalate containing 90 mol% or more, preferably 95 mol% or more of ethylene terephthalate repeating units in the molecular chain. Such a configuration is preferable in terms of elastic modulus and strength because a fiber with good crystallinity can be obtained. Such polyethylene terephthalate may also contain other copolymer components in a proportion of less than 10 mol%, preferably less than 5 mol%.

Examples of the material of the ultrahigh molecular weight polyethylene fiber include polyethylene having a viscosity average molecular weight of 1,000,000 to 7,000,000 and a melting point of 130 to 145 ° C. by a viscosity method. Such polyethylene is generally referred to as so-called ultrahigh molecular weight polyethylene. According to the polyethylene in such a range, even when a high temperature atmosphere is formed by frictional heat when the belt is used, the slip noise is sufficiently small and the wear resistance of the surface layer 7 is high. The reason for this is not clear, but there is almost no thermal deformation due to frictional heat generated when using the belt, and as in the case of using ordinary polyethylene, the portion in contact with the pulley increases and friction increases due to thermal deformation. This is thought to be due to the fact that it is suppressed.
Further, for example, as in the case of using ordinary polyethylene fine particles having a number average molecular weight of 1,000,000 or less, it dissolves in rubber at the time of kneading, and does not exist as particles on the rib surface, and cannot be brought into contact with the pulley as fine particles. There is no such a fear.
The melting point of polyethylene is measured by the DSC method. Specifically, the melting peak temperature (Tpm) is read at a heating rate of 10 ° C./min during the measurement, and the others are measured in accordance with JIS K 7121. Is.

  Examples of the ultra-high molecular weight polyethylene fiber include those having a tensile strength of 25 to 40 cN / dtex, an elongation of 3.5 to 4.5%, and a tensile modulus of 800 to 1200 cN / dtex.

  Examples of the polypropylene fiber include those having a breaking strength of 8 to 12 cN / dtex, a breaking elongation of 10 to 40%, a Young's modulus of 60 to 140 cN / dtex, and a heat shrinkage of 5 to 15% (140 ° C.). .

  Examples of the polyparaphenylene benzobisoxazole fiber include those having a strength of 30 to 50 cN / dtex, a breaking elongation of 2 to 4%, and an elastic modulus of 1000 to 2500 cN / dtex.

  As a material of the polyarylate fiber, polyester made of diphenol is preferable. Examples of the polyarylate fibers include those having a tensile strength of 20 to 30 cN / dtex, a breaking elongation of 2 to 5%, and an initial elastic modulus of 500 to 750 cN / dtex.

As the short fibers, those having a length of 0.3 to 1.5 mm and an L / D ratio of 20 to 150 are preferably used.
If it is a short fiber of such a range, there will be a more excellent slip noise reduction effect.

  As the short fiber, the para-aramid fiber, the polyethylene terephthalate fiber, and the ultra-high molecular weight polyethylene fiber are preferable from the viewpoint of obtaining a more excellent slip noise reduction effect and a surface layer 7 wear resistance improvement effect. .

The content of the short fiber in the surface layer is preferably 10 to 60% by volume, more preferably 30 to 60% by volume from the viewpoint of more sufficient slip noise reduction.
The content of the short fibers in the surface layer includes the volume of the solid content of the resin composition containing the resin component used for forming the surface layer, and the volume of the short fibers added to the resin composition. It is calculated by the ratio of the volume of the short fiber to the sum of. The solid content of the resin composition represents all components that can react during the curing reaction to form a surface layer. Therefore, in principle, the volume of the solid content of the resin composition becomes the volume of the resin component.
The volume of the resin component is determined by dividing the weight after leaving the resin composition at 120 ° C. for 5 minutes by the specific gravity of the resin composition. The volume of the short fiber to be added is determined by dividing the weight by the specific gravity of the fiber material.

  As the resin component, one containing at least a urethane resin can be used.

  Examples of the urethane resin include a reaction product of a polyol component and a polyisocyanate component. Examples of the polyol component include polyester polyols, polyolefin polyols, polyether polyols, polycarbonate polyols, and polyacrylic polyols. Examples of the urethane resin include a reaction product obtained by reacting a urethane prepolymer composition containing a urethane prepolymer obtained from a polyol component and a polyisocyanate component and a polyisocyanate component during a curing reaction.

  Here, examples of the polyester-based polyol include compounds having two or more ester bonds and two or more hydroxyl groups in the molecule. Specifically, for example, one or more of ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, cyclohexanedimethanol, glycerin, 1,1,1-trimethylolpropane, and other low molecular polyols. And a condensation polymer of glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, terephthalic acid, isophthalic acid, dimer acid, other low molecular carboxylic acid or oligomeric acid, or Examples thereof include ring-opening polymers such as propionlactone, valerolactone and caprolactone.

  Examples of the polyolefin-based polyol include compounds having 4 or more olefins and 2 or more hydroxyl groups in the molecule. Specifically, for example, diene compounds such as butadiene and isoprene and, if necessary, styrene and acrylonitrile are polymerized in the presence of an anionic polymerization catalyst such as metal lithium, metal potassium and metal sodium, and then ethylene oxide and propylene. Polyols obtained by addition polymerization of alkylene oxides such as oxides, or polyols obtained by radical polymerization of the diene compound with a radical initiator having a hydroxyl group such as hydrogen peroxide, or those obtained by hydrogenation of these. Etc.

  Examples of the polyether polyol include compounds having two or more ether bonds and two or more hydroxyl groups in the molecule. Specifically, for example, an alkylene oxide such as ethylene oxide, propylene oxide or butylene oxide, or a mixture thereof is added to ethylene glycol, propylene glycol, glycerin, trimethylolpropane or the like in the presence of an alkali catalyst. And polytetramethylene glycol obtained by polymerizing tetrahydrofuran under a cationic catalyst, or a mixture thereof.

  Examples of the polycarbonate polyol include 1,6-hexanediol polycarbonate polyol, 1,6-hexanediol and 1,4-butanediol polycarbonate polyol, 1,6-hexanediol and 1,5-pentanediol. Examples include polycarbonate polyol, polycarbonate polyol of 1,6-hexanediol and 3-methyl-1,5-pentanediol.

  Examples of the polyacrylic polyol include a polymer compound obtained by polymerizing an acrylic acid derivative monomer or a polymer compound obtained by copolymerizing an acrylic acid derivative monomer and other monomers, with a hydroxyl group at the terminal. There are things you have. Among them, those obtained by polymerizing acrylic acid derivative monomers such as ethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and hydroxybutyl methacrylate alone, and acrylic polyols copolymerized by adding other monomers such as styrene are preferably used. .

  The polyisocyanate component can be defined as a compound having two or more isocyanate groups in the molecule. Specifically, for example, 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), 4,4′-diphenylmethane diisocyanate (4,4′- Fragrances such as MDI), 2,4′-diphenylmethane diisocyanate (2,4′-MDI), 1,4-phenylene diisocyanate, polymethylene polyphenylene polyisocyanate, tolidine diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI) Group polyisocyanate, hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, norbornene diisocyanate methyl (NBDI), xylylene diisocyanate (XDI), tetramethyl Aliphatic polyisocyanates such as xylylene diisocyanate (TMXDI), transcyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), H6XDI (hydrogenated XDI), alicyclic polyisocyanates such as H12MDI (hydrogenated MDI), and the above Carbodiimide-modified polyisocyanates of these polyisocyanates, or isocyanurate-modified polyisocyanates thereof. These isocyanate components can be used alone or in combination.

  Examples of the urethane prepolymer include a polyurethane compound obtained by reacting the polyol component and the polyisocyanate component by a well-known general method.

The urethane resin is preferably at least one of a polyester-based urethane resin using a polyester-based polyol and a polyolefin-based urethane resin using a polyolefin-based polyol, from the viewpoint of reducing slip noise due to a low friction coefficient. Can be included.
More preferably, examples of the urethane resin include those using a urethane prepolymer composition containing a urethane prepolymer comprising a polyol component containing at least one of a polyester-based polyol and a polyolefin-based polyol and a polyisocyanate component. be able to. The molecular weight of the urethane prepolymer is not particularly limited. However, if the molecular weight of the urethane prepolymer becomes too large, the viscosity when the urethane prepolymer is dissolved in a solvent becomes too large, so that it is dissolved in the solvent to a concentration of 30 to 50% by weight. It is preferable that the molecular weight be such that the viscosity is 1000 mPa · s or less. The urethane prepolymer composition thus prepared is preferably used as a composition for adhering to the surface layer because it has a relatively low viscosity and can be easily applied to the surface layer.
Moreover, a commercial item can also be used as said urethane prepolymer.

  The surface layer 7 is formed by adhering a resin composition in which an uncured resin component and the short fibers are kneaded to the inner surface of the compression layer 5 by application, for example, and curing the adhering resin composition. Has been.

For example, the surface layer 7 is prepared by mixing a urethane prepolymer solution in which a urethane prepolymer and a polyisocyanate component are dispersed in an organic solvent or the like to prepare a urethane resin composition, It can be formed by polymerizing the urethane prepolymer by mixing the short fibers to form a coating solution for the surface layer, applying the coating solution for the surface layer to the surface of the compression layer 5 and heating.
The surface layer 7 is prepared, for example, by preparing a one-component urethane resin composition in which a urethane prepolymer whose polymerization amount is adjusted by the presence of a blocking agent is dispersed in a solvent such as water. It is possible to form a surface layer coating solution by mixing the short fibers, and apply the surface layer coating solution to the surface of the compression layer 5 and heat it to polymerize the urethane prepolymer.

  Although it does not specifically limit as said hardening | curing agent, For example, the 1 type chosen from the polyhydric amine and polyhydric alcohol containing an aliphatic or aromatic ring, or 2 or more types of mixtures can be mentioned.

  As the organic solvent, those not reactive with an isocyanate group are preferable, and examples thereof include toluene, xylene, ethyl acetate, methylene chloride, acetone, methyl ethyl ketone, dioxane, cyclohexanone, propylene carbonate, and the like.

  The blocking agent is not particularly limited, and examples thereof include oxime blocking agents such as methyl ethyl ketoxime, acetoxime, cyclohexanone oxime, acetophenone oxime, and benzophenone oxime, and phenols such as m-cresol and xylenol. Blocking agents, alcohol-based blocking agents such as methanol, ethanol, butanol, 2-ethylhexanol, cyclohexanol, ethylene glycol monoethyl ether, and the like are used.

  The compression layer 5 is formed of a rubber composition, and the adhesive layer 3 is formed by embedding a plurality of tensile bodies 4 in rubber at intervals in the width direction. The cover layer 2 is formed by using a conventionally known rubber sheet as the cover layer 2.

The rubber used for the rubber composition of the compression layer 5 is a rubber generally used for the compression layer of the V-ribbed belt, for example, natural rubber, polyisoprene rubber, epoxidized natural rubber, styrene-butadiene copolymer rubber, polybutadiene rubber. , Acrylonitrile-butadiene copolymer rubber, hydrogenated acrylonitrile-butadiene copolymer rubber, ethylene-α-olefin elastomer, butyl rubber, chlorosulfonated polyethylene, alkylated chlorosulfonated polyethylene, chlorinated polyethylene, etc. alone or in combination Can be used.
Of these, ethylene-α-olefin elastomers are preferred because they are excellent in heat resistance and cold resistance and are relatively inexpensive.
As this ethylene-α-olefin elastomer, for example, ethylene-propylene copolymer, ethylene-propylene-diene terpolymer, ethylene-octene copolymer, ethylene-butene copolymer can be used. It is suitable for its low cost and excellent processability and high crosslinking efficiency.

  In the rubber composition, carbon black, a plasticizer, an anti-aging agent, a processing aid, a vulcanizing agent, a vulcanization accelerator, which are usually used in a rubber composition for a transmission belt, as long as the effects of the present invention are not impaired. A crosslinking aid, an inorganic filler, etc. can be contained.

  As the vulcanizing agent, a sulfur-based vulcanizing agent or an organic peroxide-based vulcanizing agent can be used. Examples of the sulfur vulcanizing agent include powdered sulfur, precipitated sulfur, highly dispersible sulfur, surface-treated sulfur, insoluble sulfur, dimorpholine disulfide, alkylphenol disulfide and the like. Examples of the organic peroxide vulcanizing agent include di-t-butyl peroxide, dicumyl peroxide, t-butyl cumyl peroxide, 1,1-t-butylperoxy-3,3,5-trimethyl. Cyclohexane, 2,5-dimethyl-2,5-di- (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di-t-butylperoxy) hexyne-3, bis (t-butyl) Peroxy-diisopropyl) benzene, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxybenzoate, t-butylperoxy-2-ethyl-hexyl carbonate, and the like.

As the vulcanization accelerator, those of thiazole, thiuram, and sulfenamide can be used. As the thiazole vulcanization accelerator, 2-mercaptobenzothiazole, 2-mercaptothiazoline, dibendhiazyl disulfide, Examples thereof include zinc salts of 2-mercaptobenzothiazole, and examples of the thiuram vulcanization accelerator include tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, N, N′-dimethyl. -N, N'-diphenylthiuram disulfide can be exemplified, and examples of the sulfamide vulcanization accelerator include N-cyclohexyl-2-benzothiazylsulfenamide, N, N'-cyclohexyl-2- Benzothiazylsulfenamide, etc. It can be exemplified.
In addition, bismaleimide, ethylenethiourea and the like can be used as other vulcanization accelerators.
These vulcanization accelerators may be used alone or in combination of two or more.

  Examples of the crosslinking aid include triallyl isocyanurate, 1,2-polybutadiene, metal salt of unsaturated carboxylic acid, oximes, guanidine, trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, NN′-m-phenylene. Bismaleimide or the like can be used.

  As said inorganic filler, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, zinc hydroxide, hydrotalcite etc. can be used, for example.

  The V-ribbed belt of this embodiment can be manufactured by the following method, for example. First, various materials contained in the rubber composition of the compression layer 5 are kneaded by a general rubber kneading means such as a kneader, a Banbury mixer, a roll, a biaxial kneader, and the unvulcanized rubber composition. To do. Next, this unvulcanized rubber composition is formed into a sheet by a sheeting means such as a calender roll. Further, the unvulcanized rubber composition formed into a sheet is laminated on the cylindrical mold together with the rubber sheet of the cover layer, the rubber of the adhesive layer, the tensile body, and the like. Subsequently, a cylindrical preform is prepared by crosslinking and integration using a vulcanizing can or the like. Then, after a predetermined rib is formed on the cylindrical preform using a grinding wheel or the like, it is cut into a predetermined number of ribs. Further, a surface layer coating solution for forming the surface layer is applied to the surface and cured. The surface layer coating solution can be prepared by mixing a urethane resin composition containing urethane prepolymer, polyisocyanate, solvent, and the like and short fibers.

The power transmission belt of the present embodiment is as described above, but the power transmission belt of the present invention can also use a rubber-coated canvas as a cover layer. Further, as the rubber sheet of the cover layer, the rubber-coated canvas, the rubber of the adhesive layer, and the tensile body, general rubber, canvas, and tensile body used for the transmission belt can be used.
The power transmission belt of the present invention is not limited to the V-ribbed belt, and may be a general V-belt, flat belt, round belt, or the like.

  EXAMPLES Next, although an Example is given and this invention is demonstrated in more detail, this invention is not limited to these.

  First, each urethane prepolymer was prepared to prepare each urethane resin composition, and each surface layer coating solution was further prepared. Each V-ribbed belt was manufactured using the prepared coating liquid for each surface layer.

(Preparation of urethane prepolymer)
Urethane prepolymer of Preparation Examples 1 to 5 by adding 74% by weight of toluene with respect to the weight of the mixture of the polyol component and diisocyanate component (isocyanate A and isocyanate B) shown in Table 1 and reacting at 100 ° C. for 4 hours. Was prepared. As shown in Table 1, 1.1 times (mole) of isocyanate A and 0.41 times (mole) of isocyanate B were added to 1.0 mol of OH group mole of the polyol component.

(Preparation of urethane resin composition)
Next, after the toluene solution of the urethane prepolymer was cooled to 70 ° C., 74% of butyl acetate and 18% of methyl ethyl ketone (MEK) were added to the weight of the urethane prepolymer and stirred for 30 minutes. The amount of solvent added was such that the sum of the polyol component and the diisocyanate component would be a concentration of 37.6% by weight. Thus, each urethane resin composition was prepared.

(Preparation of coating solution for surface layer)
The following short fibers were added to the urethane resin composition so as to have a desired amount, and the mixture was stirred and mixed in a beaker to prepare each surface layer coating solution. The details of the composition are shown in Tables 2-4.

(Type of short fiber)
UHMWPE: Toyobo's ultra high molecular weight polyethylene fiber “Dyneema”
PET: Toray polyethylene terephthalate fiber “T900”
PP: Ube Nitto Kasei High Strength Polypropylene Fiber "Symtex HT"
PBO: Toyobo polyparaphenylene benzobisoxazole fiber "Zylon HT"
Polyarylate: Kuraray polyarylate fiber "Vectran HT"
Aramid: Para-aramid fiber “Technora” manufactured by Teijin Techno Products
Acrylic: Toray acrylic fiber "Toreron"
Vinylon: Unitika made vinylon fiber “Unitika Vinylon”
Rayon: Made of Ohmiken Rayon fiber nylon 66: Rhodia made nylon 66 fiber

[Example 1]
(Preparation of unvulcanized sheet of rubber composition for compression layer)
A rubber composition for a compression layer was prepared by kneading using a Banbury mixer with the following composition, and the prepared rubber composition was formed into a sheet by a calender roll.
<Composition of rubber composition for compression layer>
EPDM (manufactured by Dow Chemical Company, trade name “Nodel IP4725”): 100 parts by weight,
Carbon black (product name “Seast 3” manufactured by Tokai Carbon Co., Ltd.): 75 parts by weight
Paraffin oil (trade name “Sunflex 2280” manufactured by Nihon Sun Co., Ltd.): 14 parts by weight, zinc oxide (trade name “Zinc Hana 1” manufactured by Sakai Chemical Industry Co., Ltd.): 5 parts by weight,
Stearic acid (manufactured by NOF Corporation, trade name “bead stearic acid candy”): 1 part by weight,
Anti-aging agent (manufactured by Ouchi Shinsei Chemical Co., Ltd., “NOCRACK 224”): 2.5 parts by weight
Tackifier (petroleum resin manufactured by Nippon Zeon Co., Ltd., trade name “Quinton A-100”): 5 parts by weight, sulfur (manufactured by Tsurumi Chemical Co., Ltd., trade name “oil sulfur”): 2 parts by weight,
Vulcanization accelerator (manufactured by Ouchi Shinsei Chemical Co., Ltd., “Noxeller MSA”): 4 parts by weight

(Preparation of unvulcanized sheet of adhesive layer rubber composition)
The following composition was kneaded using a Banbury mixer to prepare a rubber composition for an adhesive layer, and the prepared rubber composition was formed into a sheet by a calendar roll.
<Formulation of adhesive layer rubber composition>
EPDM (Mitsui Chemicals, trade name “3085”, ethylene content 62% by weight,
Propylene content 33.5 wt%, diene content 4.5 wt%): 100 parts by weight,
Carbon black (product name “IP600” manufactured by Showa Cabot Co., Ltd.): 50 parts by weight,
Silica (manufactured by Tokuyama Corporation, trade name “Tokushiru Gu”): 20 parts by weight,
Paraffin oil (Nippon Sun Co., Ltd., trade name “Sunflex 2280”): 10 parts by weight, Vulcanizing agent (Nippon Yushi Co., Ltd., DCP, trade name “Park Mill D”): 2.5 parts by weight,
Vulcanization aid (stearic acid manufactured by Kao Corporation): 1 part by weight,
Vulcanization aid (Zinc oxide manufactured by Sakai Chemical Industry Co., Ltd.): 5 parts by weight
Tackifier (petroleum resin manufactured by Nippon Zeon Co., Ltd., trade name “Quinton A-100”): 5 parts by weight
Short fiber (cotton powder): 2 parts by weight

(Preparation of RFL adhesive composition)
7.31 parts by weight of resorcin and 10.77 parts by weight of formalin (37% by weight concentration) are mixed, an aqueous sodium hydroxide solution (solid content 0.33% by weight) is added and stirred, and then water 160.91 is added. A part by weight was added and aged for 5 hours to prepare an aqueous solution of resorcin-formalin resin (resorcin-formalin initial condensate, hereinafter referred to as “RF”, resorcin / formalin ratio = 0.5).
Next, chlorosulfonated polyethylene latex (solid content 40%) is mixed with the RF aqueous solution so that the RF / latex ratio = 0.25 (solid content 45.2 parts by weight), and water is further added to obtain a solid content concentration of 20 After adjusting to be%, the RFL adhesive composition was prepared by stirring while aging for 12 hours.

(Production of tensile body (core wire))
After immersing Teijin's polyester cord (1000 denier / 2 × 3, upper twist 9.5 T / 10 cm (Z), lower twist 2.19 T / 10 cm) in a toluene solution of isocyanate (isocyanate solid content 20 wt%), It was dried with hot air at 240 ° C. for 40 seconds and pretreated. The core wire after this pretreatment was immersed in the RFL adhesive composition, and then dried with hot air at 200 ° C. for 80 seconds. Further, EPDM (trade name “3085” manufactured by Mitsui Chemicals, Inc., ethylene content: 62% by weight, propylene It was immersed in a toluene solution having a content of 33.5% by weight and a diene content of 4.5% by weight, followed by hot air drying at 60 ° C. for 40 seconds.

(Preparation of rubber coated canvas)
Polyester cotton canvas as canvas ((characteristic when processed into wide angle) Yarn material: blended canvas of polyester and cotton; weight ratio of polyester to cotton 50:50; Yarn composition Warp: 20S / 2 Meaning of two pieces combined), weft: 20 S / 2 (meaning two pieces from 20 pieces); Number of twists: warp S twist 59 times / 10 cm, weft: 59 times / 10 cm; Weave: plain weave The product was processed so that the crossing angle between the warp and the weft was 120 ° (90 ° is also acceptable); yarn density: warp: 85 / 5cm, weft: 85 / 5cm]. This polyester cotton canvas was immersed in the above RFL adhesive composition and dried by heating at 150 ° C. for 3 minutes. The polyester cotton canvas thus treated is immersed in an adhesive rubber solution prepared by dissolving the same composition as the above adhesive layer rubber composition in toluene, and then heated and dried at 60 ° C. for 10 seconds to be processed into a polyester cotton canvas. The rubber coat canvas which gave was obtained.

(Manufacture of V-ribbed belt)
First, a rubber-coated canvas, an adhesive layer rubber, a tensile body, and an adhesive layer rubber were sequentially laminated on the outer periphery of the cylindrical mold, and finally a rubber sheet for a compression layer was laminated. Next, this cylindrical mold was inserted into a cylindrical vulcanizing can and steam vulcanized under conditions of a temperature of 160 ° C. × 20 minutes to produce a preform (cylindrical body).
The outer periphery of the preform is ground along the circumferential direction so that three ribs are formed per 10 mm in width, and this cylindrical body is cut into three ribs, and the width is 10 mm and the circumference is about A 1100 mm V-ribbed belt body was produced.
(Formation of surface layer)
Next, the surface layer was added to the urethane resin composition using the polyester-based urethane prepolymer shown in Preparation Example 1 of Table 1 so that the short fibers were 30% by volume with respect to the solid content of the urethane resin composition. A coating solution was prepared. As the short fibers, Toyobo's ultra high molecular weight polyethylene fiber “Dyneema” (length 0.6 mm, diameter 12 μm) (hereinafter also referred to as UHMWPE) was used. The surface layer coating solution thus prepared was applied to the surface of the compression layer and heated at 90 ° C. for 30 minutes to cure the coating solution, whereby the V-ribbed belt of Example 1 was produced.

[Example 2]
As in Example 1, except that Toray polyethylene terephthalate fiber “T900” (length: 0.6 mm, diameter: 12 μm) (hereinafter also referred to as PET) was used as the short fiber to be blended in the surface layer coating solution. A V-ribbed belt of Example 2 was manufactured.

[Example 3]
Example 1 except that a high-strength polypropylene fiber “Shimtex” (length 0.6 mm, diameter 12 μm) (hereinafter also referred to as PP) manufactured by Ube Nitto Kasei was used as the short fiber to be blended in the surface layer coating solution. In the same manner as described above, the V-ribbed belt of Example 3 was manufactured.

[Example 4]
Example 1 except that Toyobo polyparaphenylenebenzobisoxazole fiber “Zylon” (length 0.6 mm, diameter 12 μm) (hereinafter also referred to as PBO) was used as a short fiber to be blended in the surface layer coating solution. In the same manner as described above, the V-ribbed belt of Example 4 was manufactured.

[Example 5]
As in Example 1, except that Kuraray polyarylate fiber “Vectran” (length: 0.6 mm, diameter: 12 μm) (hereinafter also referred to as polyarylate) was used as the short fiber to be blended in the surface layer coating solution. Thus, a V-ribbed belt of Example 5 was manufactured.

[Example 6]
Example 6 was the same as Example 1 except that Tarajin Techno Products para-type aramid fiber “Technola” (length 0.2 mm, diameter 12 μm) was used as the short fiber to be blended in the surface layer coating solution. V-ribbed belts were manufactured.

[Example 7]
Example 7 was the same as Example 1 except that Tarajin Techno Products' para-aramid fiber “Technola” (length 0.4 mm, diameter 12 μm) was used as the short fiber to be blended in the surface layer coating solution. V-ribbed belts were manufactured.

[Example 8]
Example 8 was the same as Example 1 except that Tarajin Techno Products' para-aramid fiber “Technola” (length 1.5 mm, diameter 10 μm) was used as the short fiber to be blended in the surface layer coating solution. V-ribbed belts were manufactured.

[Example 9]
In the same manner as in Example 1, except that para-aramid fiber “Technola” (length: 2 mm, diameter: 24 μm) manufactured by Teijin Techno Products was used as the short fiber to be blended in the coating solution for the surface layer, V of Example 9 A ribbed belt was produced.

[Example 10]
Example 10 is the same as Example 1 except that Tarajin Techno Products' para-aramid fiber “Technola” (length 0.5 mm, diameter 24 μm) is used as the short fiber to be blended in the surface layer coating solution. V-ribbed belts were manufactured.

[Example 11]
In the same manner as in Example 1 except that para-aramid fiber “Technola” (length: 2 mm, diameter: 12 μm) manufactured by Teijin Techno Products was used as the short fiber to be blended in the surface layer coating solution. A ribbed belt was produced.

[Example 12]
Para-aramid fiber “Technola” (length: 0.6 mm, diameter: 12 μm) manufactured by Teijin Techno Products is used as the short fiber to be blended in the coating solution for the surface layer, and the short fiber relative to the solid content of the urethane resin composition A V-ribbed belt of Example 12 was produced in the same manner as in Example 1 except that the amount was 5% by volume.

[Example 13]
Para-aramid fiber “Technola” (length: 0.6 mm, diameter: 12 μm) manufactured by Teijin Techno Products is used as the short fiber to be blended in the coating solution for the surface layer, and the short fiber relative to the solid content of the urethane resin composition A V-ribbed belt of Example 13 was produced in the same manner as in Example 1 except that the amount was 10% by volume.

[Example 14]
Para-aramid fiber “Technola” (length: 0.6 mm, diameter: 12 μm) manufactured by Teijin Techno Products is used as the short fiber to be blended in the coating solution for the surface layer, and the short fiber relative to the solid content of the urethane resin composition A V-ribbed belt of Example 14 was produced in the same manner as in Example 1 except that the amount was 60% by volume.

[Example 15]
Para-aramid fiber “Technola” (length: 0.6 mm, diameter: 12 μm) manufactured by Teijin Techno Products is used as the short fiber to be blended in the coating solution for the surface layer, and the short fiber relative to the solid content of the urethane resin composition A V-ribbed belt of Example 15 was produced in the same manner as in Example 1 except that the amount was adjusted to 70% by volume.

[Example 16]
Example 16 is the same as Example 1 except that para-aramid fiber “Technola” (length 0.5 mm, diameter 24 μm) manufactured by Teijin Techno Products is used as the short fiber to be blended in the surface layer coating solution. V-ribbed belts were manufactured.

[Example 17]
As the urethane prepolymer blended in the surface layer coating liquid, the polyolefin urethane prepolymer of Preparation Example 2 in Table 1 was used. As the short fiber blended in the surface layer coating liquid, Tarajin Techno Products Para-aramid fiber Except for using “Technola” (length: 0.5 mm, diameter: 24 μm) and blending short fibers at 31% by volume with respect to the solid content of the urethane resin composition, the same as in Example 1. A V-ribbed belt of Example 17 was produced.

[Example 18]
As the urethane prepolymer blended in the surface layer coating liquid, the polyether urethane prepolymer of Preparation Example 3 in Table 1 was used. As the short fiber blended in the surface layer coating liquid, Tarajin Techno Products' para-aramid Example 1 except that the fiber “Technola” (length: 0.5 mm, diameter: 24 μm) was used, and the short fibers were blended so as to be 32% by volume with respect to the solid content of the urethane resin composition. Thus, a V-ribbed belt of Example 18 was manufactured.

[Example 19]
As the urethane prepolymer blended in the surface layer coating liquid, the polycarbonate-based urethane prepolymer of Preparation Example 4 in Table 1 was used. As the short fiber blended in the surface layer coating liquid, Tarajin Techno Products' para-aramid fiber Except for using “Technola” (length: 0.5 mm, diameter: 24 μm) and blending the short fibers at 33% by volume with respect to the solid content of the urethane resin composition, the same as in Example 1. A V-ribbed belt of Example 19 was produced.

[Example 20]
As the urethane prepolymer blended in the surface layer coating liquid, the polyacrylic urethane prepolymer of Preparation Example 5 in Table 1 was used. As the short fiber blended in the surface layer coating liquid, Tarajin Techno Products' para-aramid Example 1 except that the fiber “Technola” (length: 0.5 mm, diameter: 24 μm) was used, and the short fibers were blended in an amount of 34% by volume with respect to the solid content of the urethane resin composition. Thus, a V-ribbed belt of Example 20 was manufactured.

[Comparative Example 1]
Without forming a surface layer, para-aramid fiber “Technola” (length 0.5 mm, diameter 24 μm) manufactured by Teijin Techno Products was adjusted so that the content in the rubber composition for the compression layer was 10% by volume, A V-ribbed belt of Comparative Example 1 was produced.

[Comparative Example 2]
As short fibers blended in the surface layer coating solution, Toray acrylic fiber “Trelon” (length 0.6 mm, diameter 12 μm) (hereinafter also referred to as acrylic) was used in the same manner as in Example 1, A V-ribbed belt of Comparative Example 2 was produced.

[Comparative Example 3]
As in Example 1, except that Unitika vinylon fiber “Unitika Vinylon” (length: 0.6 mm, diameter: 14 μm) (hereinafter also referred to as “vinylon”) was used as the short fiber to be blended in the surface layer coating solution. A V-ribbed belt of Comparative Example 3 was produced.

[Comparative Example 4]
Comparative Example 4 was carried out in the same manner as in Example 1 except that Rayon fibers (length: 0.6 mm, diameter: 12 μm) (hereinafter also referred to as rayon) manufactured by Ohmichi were used as the short fibers to be blended in the surface layer coating solution. V-ribbed belts were manufactured.

[Comparative Example 5]
Comparison was made in the same manner as in Example 1 except that Rhodia nylon fiber 66 (length 0.6 mm, diameter 12 μm) (hereinafter also referred to as nylon 66) was used as the short fiber to be blended in the surface layer coating solution. The V-ribbed belt of Example 5 was manufactured.

[Comparative Example 6]
As the surface layer coating solution, an adhesive rubber solution in which the adhesive layer rubber composition shown in Example 1 is dissolved is used. As a short fiber to be blended in the surface layer coating solution, Toyobo's ultrahigh molecular weight polyethylene fiber “Dyneema” A V-ribbed belt of Comparative Example 6 was produced in the same manner as in Example 1 except that (length 0.6 mm, diameter 12 μm) was used.

Test Examples Using the V-ribbed belts of the examples and comparative examples, the following (evaluation of abnormal noise during belt running) and (rib surface wear rate measurement) were performed, and the results are shown in Tables 2 to 4.
(Evaluation of abnormal noise during belt running)
As shown in FIG. 2, a V-ribbed belt is wound around each of a driving pulley 51 and a driven pulley 52 each having a diameter of 120 mm, and an idler pulley 54 having a diameter of 45 mm and a diameter 45 mm so that the belt running direction changes substantially at right angles. A tension pulley 55 is disposed, and a sound level meter 56 (made by RION, model name “NA-40”) is located in the vicinity of the drive pulley 51 (about 10 cm outward from the position where the drive pulley 51 and the belt are in contact). ). Using such a belt running test apparatus, a set load 979N is applied to the tension pulley 55 in the horizontal direction, and no load is applied to the driven pulley 52. The drive pulley 51 is driven at 4900 rpm, and the drive pulley 51 is driven during belt running. The sound pressure (dB) of the slip sound when water was injected into the water (2000 cc / min for 1 minute) was measured at the time of running for 30 minutes.
Then, the sound pressure of less than 70 dB was evaluated as ◎, 70 dB or more and less than 80 dB was evaluated as ◯, 80 dB or more and less than 90 dB was evaluated as Δ, and 90 dB or more was evaluated as ×.

(Measurement of rib surface wear rate)
FIG. 3 shows a layout of a belt running tester 60 for evaluating the abrasion resistance test of the V-ribbed belt. This belt durability evaluation tester includes a pair of rib pulleys 61 and 62 having a pulley diameter of 60 mm arranged on the left and right sides (the left side is a driving pulley and the right side is a driven pulley).
For each of the V-ribbed belts of the examples and comparative examples, after measuring the belt weight, it is wound around both rib pulleys 61 and 62 so that the rib side comes into contact, and the left rib pulley that is the driving pulley is loaded with a 1177N dead weight. A belt running test was conducted by pulling 61 to the side and applying a rotational load of 7 W to the right rib pulley 62, which is a driven pulley, and rotating the left pulley 61, which is a left driving pulley, at room temperature for 24 hours at room temperature. It was. Then, the belt weight after running the belt was measured, and the wear rate was calculated based on the following equation.
Abrasion rate = {(initial weight−weight after running) / (initial weight)} × 100 [%]

Sectional drawing which shows the power transmission belt of one Embodiment. Schematic which shows the belt running test apparatus for abnormal noise evaluation. Schematic which shows a belt running test machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... V ribbed belt 2 ... Canvas 3 ... Adhesive layer 4 ... Tensile body (core wire)
5 ... Compressed layer 6 ... Rib 7 ... Surface layer

Claims (4)

A power transmission belt having a surface layer that comes into contact with the pulley when wound on a pulley, the surface layer including short fibers;
The surface layer includes a urethane resin as a base material component, and the short fibers include para-aramid fibers, polyethylene terephthalate fibers, ultra-high molecular polyethylene fibers, polypropylene fibers, polyparaphenylene benzobisoxazole fibers, polyarylate. A power transmission belt comprising at least one selected from the group consisting of fibers.   The transmission belt according to claim 1, wherein the length of the short fibers is 0.3 to 1.5 mm.   The power transmission belt according to claim 1 or 2, wherein the short fibers have an L / D ratio of 20 to 150.   The power transmission belt according to any one of claims 1 to 3, wherein the content of the short fibers in the surface layer is 10 to 60% by volume.

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