JP2009248463A - Toothed belt and manufacturing method thereof - Google Patents

Abstract

The present invention provides a toothed belt having a reinforcing cloth that can provide excellent wear resistance and can provide excellent adhesion performance to a toothed belt body, and a method for manufacturing the toothed belt.
A toothed belt having a tooth-side surface coated with a reinforcing cloth and an RFL coating provided so as to cover the reinforcing cloth is exposed to an RFL liquid in a latex solid content. A treatment liquid in which 80 to 140 parts by mass of fluororesin powder and blocked isocyanate are added with respect to part by mass is prepared, and the treatment liquid is attached to the cloth and then heated at a temperature of 150 ° C. or higher to dry. Thus, the reinforcing cloth 13 having the RFL film formed on the surface thereof is formed, and the reinforcing cloth 13 having the RFL film formed on the surface and the uncrosslinked rubber composition are integrated by heating and pressing. The block isocyanate has a bond dissociation temperature equal to or higher than the heat drying temperature after the treatment liquid is attached to the cloth.
[Selection] Figure 1

Description

  The present invention relates to a toothed belt in which a tooth side surface of a rubber toothed belt main body provided with teeth at regular intervals in the belt length direction is covered with a reinforcing cloth, and a method for manufacturing the same.

  Generally, in a toothed belt made of rubber, a tooth side surface of a toothed belt body in which teeth are provided at regular intervals in the belt length direction is covered with a reinforcing cloth. And the adhesion | attachment process for making it adhere with a toothed belt main body is given to the reinforcement cloth.

  Patent Documents 1 and 2 disclose that a woven fabric is dipped in a resorcin / formalin / latex liquid (hereinafter referred to as “RFL liquid”) and then dried to be used as a reinforcing cloth for a toothed belt. ing.

Patent Document 3 discloses that a woven fabric subjected to a treatment of dipping in an RFL solution containing fluororesin powder and then dried is used as a reinforcing fabric for a toothed belt.
JP 2003-314621 A JP 2005-180589 A Japanese Patent No. 3347095

  However, when an RFL liquid containing a fluororesin powder is used as disclosed in Patent Document 3, an excellent abrasion resistance is obtained in the reinforcing cloth, but the adhesion performance to the toothed belt body by RFL is impaired. There is a problem that it will be.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a toothed belt having a reinforcing cloth that can provide excellent wear resistance and that can provide excellent adhesion performance to a toothed belt body, and a method for producing the toothed belt.

In the method for manufacturing a toothed belt according to the present invention, the tooth side surface of a rubber toothed belt main body provided with teeth at regular intervals in the belt length direction is covered with a reinforcing cloth so as to cover the reinforcing cloth. The RFL coating provided on the toothed belt exposed on the belt surface,
Preparing a treatment liquid obtained by adding 80 to 140 parts by mass of fluororesin powder and blocked isocyanate to 100 parts by mass of the latex solid content in the RFL liquid;
A step of forming the reinforcing cloth provided with an RFL film on the surface by drying by heating at a temperature of 150 ° C. or higher after the prepared treatment liquid is attached to the cloth;
Forming a toothed belt by heating and pressurizing and integrating a reinforcing cloth having an RFL film formed on the surface and a separately prepared uncrosslinked rubber composition for forming a toothed belt body; and
With
The block isocyanate is characterized in that the bond dissociation temperature is equal to or higher than the heat drying temperature after the treatment liquid is attached to the cloth.

  In the method for producing a toothed belt of the present invention, the amount of the blocked isocyanate added to the RFL liquid is preferably 5 to 70 parts by mass with respect to 100 parts by mass of the solid content of the RFL liquid.

  In the method for producing a toothed belt of the present invention, it is preferable to use a block isocyanate having a bond dissociation temperature higher than 150 ° C.

  The method for producing a toothed belt of the present invention uses hydrogenated acrylonitrile butadiene methacrylic acid terpolymer latex, chlorosulfonated polyethylene rubber latex, or 2,3-dichlorobutadiene polymer latex as the latex of the RFL solution. It is preferable.

The toothed belt of the present invention is provided so that a tooth side surface of a rubber toothed belt main body provided with teeth at regular intervals in the belt length direction is covered with a reinforcing cloth and covers the reinforcing cloth. The RFL coating exposed on the belt surface,
The RFL liquid is heated at a temperature of 150 ° C. or higher after a treatment liquid obtained by adding 80 to 140 parts by mass of fluororesin powder and blocked isocyanate to 100 parts by mass of the latex solid content is attached to the cloth. It is formed by heating and pressurizing and integrating a reinforcing cloth having an RFL coating provided on the surface thereof and a separately prepared unvulcanized rubber composition for forming a toothed belt body,
The block isocyanate is characterized in that the bond dissociation temperature is equal to or higher than the heat drying temperature after the treatment liquid is attached to the cloth.

  According to the present invention, since the treatment liquid containing 80 to 140 parts by mass of fluororesin powder is used in the RFL liquid with respect to 100 parts by mass of the latex solid content, excellent abrasion resistance can be obtained for the reinforcing cloth. In addition, since the block dissociation temperature is higher than the heat drying temperature after the treatment liquid is attached to the cloth in the treatment liquid, the blocked isocyanate is heated by drying after the treatment liquid is attached to the cloth. The dissociation and the loss of the adhesive ability due to the dissociation are suppressed, and an excellent adhesion performance to the toothed belt body can be obtained on the reinforcing cloth.

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

(Toothed belt)
FIG. 1 shows a toothed belt 10 according to an embodiment. The toothed belt 10 is preferably used for high load applications such as an OHC drive application for automobiles.

  The toothed belt 10 has a rubber toothed belt main body 11.

  The toothed belt body 11 is formed of a crosslinked rubber composition in which a non-crosslinked rubber composition obtained by mixing a compounding agent with a base rubber and kneaded is heated and pressurized to be crosslinked with a crosslinking agent. Examples of the base rubber of the rubber composition constituting the toothed belt main body 11 include ethylene-α-olefin elastomers such as ethylene / propylene rubber (EPR) and ethylene propylene diene monomer rubber (EPDM), chloroprene rubber (CR), Examples include chlorosulfonated polyethylene rubber (CSM) and hydrogenated nitrile rubber (H-NBR). Examples of the compounding agent include cross-linking agents (for example, sulfur and organic peroxides), anti-aging agents, processing aids, plasticizers, fillers, reinforcing materials such as carbon black, silica, and short fibers. . In addition, about each compounding agent, even if comprised by single type and may be comprised by multiple types, either may be sufficient.

  The toothed belt main body 11 is provided with a back surface portion 11b on the outer peripheral side, and is provided with tooth portions 11a on the inner peripheral side integrally with the back surface portion 11b at regular intervals in the belt length direction.

  The back surface portion 11b is formed in a horizontally long flat band shape. The core wire 12 is embedded in the inner peripheral side layer of the back surface portion 11b so as to form a spiral having a pitch in the belt width direction.

  The core wire 12 is composed of a twisted yarn or braid of a long fiber material. It is preferable that the strand 12 of twisted yarn is provided so that a pair of S twist and Z twist may form a double helix. Examples of the fiber material constituting the core wire 12 include glass fiber, aramid fiber, polyparaphenylene benzobisoxazole (PBO) fiber, and metal fiber. The core 12 is subjected to an adhesive treatment for heating after being immersed in an RFL liquid before molding and / or an adhesive treatment for drying after being immersed in rubber paste in order to impart adhesion to the toothed belt body 11. It is.

  The tooth portion 11a may be formed as a trapezoidal tooth whose side view is trapezoidal, may be formed as a semicircular round tooth, or may be formed in another shape. The tooth portion 11a may have a configuration provided so as to extend in the belt width direction, or may have a helical tooth configuration provided so as to extend in a direction inclined with respect to the belt width direction. Also good.

  The toothed belt body 11 is covered with a reinforcing cloth 13 on the tooth side surface.

  The reinforcing cloth 13 is made of a woven fabric such as a plain weave, a twill weave, or a satin weave, a knitted fabric, or a non-woven fabric made of a fiber material. The cloth constituting the reinforcing cloth 13 preferably has extensibility in the belt length direction from the viewpoint of tooth portion formation. Specifically, when the fabric constituting the reinforcing fabric 13 is a woven fabric, as a yarn extending in the belt length direction, a wooly yarn or a polyurethane yarn is used as a core material, and a fiber material is covered therewith, or double covering. What is necessary is just to use the thread | yarn which carried out. Examples of the fiber material constituting the reinforcing cloth 13 include nylon fibers such as 6,6-nylon, 4,6-nylon, and 6-nylon, polyester fibers, aramid fibers, and polyparaphenylene benzobisoxazole (PBO) fibers. Is mentioned. The reinforcing cloth 13 is subjected to an RFL adhesion treatment that is heated after being immersed in a predetermined treatment liquid described in detail below before forming to provide adhesion to the toothed belt body 11.

  In order to improve the adhesion to the toothed belt body 11, the reinforcing cloth 13 may be one in which an adhesion process is applied to the adhesion surface to the toothed belt body 11 in addition to the RFL adhesion process. Examples of such an adhesion treatment include an adhesion treatment in which a rubber paste is coated and then dried, and an adhesion treatment in which a sheet rubber is adhered by a lamination or top processing method. However, the surface opposite to the surface where the reinforcing cloth 13 is bonded to the toothed belt body 11, that is, the surface constituting the pulley contact portion is not subjected to any bonding process other than the RFL bonding process described in detail below. The RFL coating is exposed.

(Manufacturing method of toothed belt)
Next, a method for manufacturing the toothed belt 10 will be described.

<Reinforcing cloth preparation process>
-Preparation of treatment solution-
A treatment liquid is prepared by adding fluororesin powder and blocked isocyanate to the RFL liquid.

  The RFL liquid is a mixed liquid in which latex is mixed with an initial condensate of resorcin and formalin (formaldehyde). About solid content of RFL liquid, it shall be 10-25 mass%, for example.

  The molar ratio of resorcin (R) to formalin (F) is, for example, R / F = 1/1 to 1/3.

  Examples of the latex include vinylpyridine latex (VP), styrene butadiene rubber latex (SBR), chloroprene rubber latex (CR), nitrile butadiene rubber latex (NBR), hydrogenated acrylonitrile butadiene methacrylic acid terpolymer (X- NBR) latex, chlorosulfonated polyethylene rubber latex (CSM), 2,3-dichlorobutadiene polymer latex (2,3-DCB) and the like. Of these, X-NBR latex, CSM latex, and 2,3-DCB latex are preferable. About latex, you may comprise by single type among these, and may mix and comprise multiple types. About mass ratio of the initial condensate (RF) of resorcin and formalin, and latex (L), it is referred to as RF / L = 1/6-1/20, for example.

  Examples of the fluororesin powder include polytetrafluoroethylene (PTFE), polytrifluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkoxyethylene copolymer, tetrafluoroethylene-ethylene copolymer. Examples thereof include powders of polymers and the like. About fluororesin powder, you may comprise by single type among these, and may comprise multiple types. For example, the fluororesin powder preferably has an average particle size of 0.2 to 0.4 μm. About the addition amount of a fluororesin powder, it is 80-140 mass parts with respect to 100 mass parts of latex solid content of RFL liquid, for example, and it is preferable that it is 100-120 mass parts. When the fluororesin powder is added to the RFL liquid, it is preferable to use a dispersion in which the fluororesin powder is previously dispersed in water. Specific examples include Fullon AD911 manufactured by Asahi Glass Co., Ltd. and Lubron LDW-40 manufactured by Daikin Industries, Ltd.

  The blocked isocyanate has a bond dissociation temperature higher than the heat treatment temperature described below. Specifically, as block isocyanate, for example, Elastron BN-27 (bond dissociation temperature 180 ° C.), Elastron BN-31 (bond dissociation temperature 180 ° C.), Elastron BN-11 (bond) manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Dissociation temperature 150 ° C.). The bond dissociation temperature of the blocked isocyanate is preferably higher than 150 ° C. from the viewpoint of the reaction temperature between resorcin and formalin. About block isocyanate, you may comprise by single type among these, and may comprise multiple types. The addition amount of the blocked isocyanate is preferably 5 to 70 parts by mass and more preferably 20 to 40 parts by mass with respect to 100 parts by mass of the solid content of the RFL liquid from the viewpoint of improving the adhesive strength.

  The treatment liquid may contain a water-dispersed resin or the like as an optional component in addition to the fluororesin and the blocked isocyanate.

  Here, the water-dispersed resin refers to a resin in which water can be a dispersion medium, water-soluble resin (water-soluble polymer compound), and resin that can form an emulsion with water (latex-based polymer). Molecular compound). Examples of the water-dispersed resin include acrylic resin emulsifiers, water-based polyurethane resins, and polyvinyl alcohol. The water-dispersed resin may be composed of a single type or a plurality of types.

-Treatment liquid immersion treatment-
The cloth constituting the reinforcing cloth 13 is dipped in the treatment liquid prepared above and then pulled up and squeezed with a roll or the like. At this time, the treatment liquid adheres to the cloth in an impregnated state.

  About liquid temperature, it shall be 15-25 degreeC, for example. The immersion time is, for example, 0.5 to 10 seconds. The number of times of processing may be one time or a plurality of times.

  In addition to the treatment of immersing the cloth in the treatment liquid, the treatment liquid may be adhered to the cloth by means of brushing the treatment liquid on the cloth or impregnating the cloth with the treatment liquid using a coater. .

-Heat drying treatment-
The cloth to which the treatment liquid is attached is passed through a heating and drying furnace and dried by heating. At this time, moisture in the treatment liquid is scattered and a condensation reaction between resorcin and formalin proceeds, whereby a reinforcing cloth 13 having an RFL film formed on the surface is prepared. In addition, since the treatment liquid contains a blocked isocyanate whose bond dissociation temperature is equal to or higher than the heating and drying temperature at this time, the dissociation of the blocked isocyanate by heating and drying after the treatment liquid is attached to the cloth, and the adhesion ability thereby Loss is deterred.

  About heat drying temperature (furnace temperature), it is 150 degreeC or more, and it is preferable to set it as 150-170 degreeC. The heat drying time is preferably 1 to 3 minutes.

  The weight per unit area of the RFL film, that is, the weight of the reinforcing cloth 13 obtained after the heat drying treatment is subtracted from the weight of the cloth before immersion in the treatment liquid, and divided by the weight of the cloth before immersion in the treatment liquid. It is preferable that it is 10-40 mass%, and it is more preferable that it is 20-30 mass%. This basis weight can be controlled by the number of dipping processes of the cloth in the treatment liquid and the degree of drawing.

<Uncrosslinked rubber composition preparation step>
A sheet-like uncrosslinked rubber composition is prepared by putting a base rubber and a compounding agent into a rubber kneading apparatus such as a Banbury mixer and kneading the mixture through a calendar or the like.

<Core preparation process>
The core wire 12 is prepared by performing an adhesion treatment in which a twisted yarn or braid is immersed in an RFL solution and then heated and / or an adhesion treatment in which the yarn is dried after being immersed in rubber paste.

<Molding process>
The reinforcing cloth 13 is formed in a cylindrical shape, and thus a cylindrical mold in which tooth portion forming grooves extending in the axial direction are formed on the outer peripheral surface at equal intervals in the circumferential direction, and the core wire 12 is spirally wound thereon. Further, a sheet-like uncrosslinked rubber composition is wound thereon. In the case of the non-extensible reinforcing cloth 13, the reinforcing cloth 13 may be provided along the tooth portion forming groove.

  Subsequently, the cylindrical mold in which the reinforcing cloth 13, the core wire 12, and the uncrosslinked rubber composition are set is placed in a vulcanizer and heated and pressurized. At this time, the rubber flows to the cylindrical mold side by heating and pressurizing, and particularly in the tooth portion forming groove portion, the reinforcing cloth 13 is extended along the groove surface by pressing the rubber to form belt teeth. . In addition, the toothed belt body 11 is formed, and a cylindrical slab in which the core wire 12 and the reinforcing cloth 13 are integrated is formed.

  Then, the cylindrical mold is taken out from the vulcanizer and the slab is taken out.

  Finally, the back surface of the slab is polished to equalize the thickness and then cut into a predetermined width.

  According to the manufacturing method of the toothed belt 10 as described above, in the preparation of the reinforcing cloth 13, a treatment liquid containing 80 to 140 parts by mass of fluororesin powder with respect to 100 parts by mass of the latex solid content is added to the RFL liquid. Since it is used, the reinforcing cloth 13 has excellent wear resistance, and the treatment liquid contains a blocked isocyanate whose bond dissociation temperature is equal to or higher than the heating and drying temperature after the treatment liquid is attached to the cloth. The dissociation of the blocked isocyanate due to heat drying after the treatment liquid is attached to the cloth and the loss of the adhesive ability thereby are suppressed, and the reinforcing cloth 13 has excellent adhesion performance to the toothed belt body 11.

(Test evaluation belt)
Hereinafter, each toothed belt of Examples 1-14 and Comparative Examples 1-13 was produced. Each structure is also shown in Table 1A and Table 1B.

<Example 1>
Resorcin (product name: resorcinol, manufactured by Sumitomo Chemical Co., Ltd.) and formalin (product name: formalin, manufactured by Mitsui Chemicals, Inc.) are added in a sodium hydroxide solution at a molar ratio R / F = 1/2 and stirred. By mixing these, the initial condensate solution is obtained, and hydrogenated acrylonitrile butadiene methacrylic acid terpolymer (X-NBR) latex (trade name: ZLX-B, manufactured by Nippon Zeon Co., Ltd.) and water are added thereto. In addition, an RFL solution having a mass ratio of resorcin / formalin to latex of RF / L = 1/8 was prepared by stirring and mixing.

  Next, polytetrafluoroethylene (hereinafter referred to as “PTFE”) (trade name: Fluon AD911, manufactured by Asahi Glass Co., Ltd.) with respect to 100 parts by mass of latex solid content of the RFL solution is added to the RFL solution. 25 μm) 80 parts by mass and blocked isocyanate (Daiichi Kogyo Seiyaku Co., Ltd., trade name: Elastolon BN-27, bond dissociation temperature 180 ° C.) 30 parts by mass, mixed with stirring, and carbon black (Fuji Dye Industry Co., Ltd.). Product name: Fuji SP Black 203) was added and dispersed so as to be 5% by mass of the whole, and a treatment liquid having a solid content concentration of 15% by mass was prepared.

  After dipping a 3/3 twill weave fabric using woolly processed yarn (breaking elongation of 150% or more) of 6,6-nylon fiber with warp of 235 dtex and weft of 235 dtex × 3 in this treatment liquid The treatment liquid was adhered to the twill weave by squeezing through a pair of pressure rolls. At this time, the liquid temperature of the treatment liquid was 20 ° C., the immersion time was 2 seconds, and the number of treatments was 2. Further, the clearance of the pressure roll was adjusted so that the basis weight of the RFL film was about 30% by mass.

  The twill woven fabric to which the treatment liquid was attached was passed through a heating and drying oven and dried by heating to prepare a reinforcing fabric. At this time, the furnace temperature (heat drying temperature) of the heat drying furnace was 150 ° C., and the heat treatment time was 2 minutes.

  Using this reinforcing cloth, a toothed belt was produced in the same manner as in the above embodiment, and this was designated as Example 1.

  As an uncrosslinked rubber composition, hydrogenated nitrile rubber (H-NBR) (trade name: Zetpol 2020, manufactured by Nippon Zeon Co., Ltd.) is used as a base rubber, and zinc oxide (酸化) is added to 100 parts by mass of this base rubber. Chemical Industry Co., Ltd. product name: Zinc Oxide 3 types 5 parts by weight, stearic acid (Shin Nihon Rika Co., Ltd. product name: Stearic acid) 1 part by mass, Dioctyl Sebacate (DOS) (Dainippon Ink & Chemicals, Inc.) Product name: Monosizer W280) 5 parts by mass, carbon black FEF (manufactured by Tokai Carbon Co., Ltd., product name: Seast SO) 50 parts by mass, anti-aging agent (manufactured by Ouchi Shinsei Chemical Co., Ltd.) Nocrack MB) 3 parts by mass, crosslinking accelerator TET-G (manufactured by Sanshin Chemical Industry Co., Ltd.) Product name: Sunseller TET-G), 2 parts by mass, crosslinking accelerator TS-G (manufactured by Sanshin Chemical Industry Co., Ltd.) Product name: Suncellor TS-G) 1.2 parts by mass and sulfur (trade name: Oil Sulfur manufactured by Hosoi Chemical Industry Co., Ltd.) 0.7 parts by mass were mixed and kneaded (see Table 2).

  As the core wire, a 3/13 twisted glass fiber yarn subjected to a heating treatment after being immersed in the RFL solution was used.

  The produced toothed belt has a belt circumferential length of 840 mm, a belt width of 12.7 mm, a belt thickness of 5.2 mm, a tooth width of a tooth portion of 2.15 mm, a tooth height of 3.05 mm, a tooth width of 10 mm, and a tooth. This is an STS8M type configuration with a part arrangement pitch of 8 mm.

<Example 2>
A toothed belt having the same configuration as in Example 1 was prepared except that a treatment liquid in which the amount of PTFE added was 110 parts by mass with respect to 100 parts by mass of the latex solid content of the RFL liquid was prepared. It was.

<Example 3>
A toothed belt having the same configuration as in Example 1 was prepared except that a treatment liquid in which the amount of PTFE added was 140 parts by mass with respect to 100 parts by mass of the latex solid content of the RFL liquid was prepared. It was.

<Example 4>
A toothed belt having the same configuration as in Example 2 was prepared except that the treatment liquid in which the amount of the blocked isocyanate was 5 parts by mass with respect to 100 parts by mass of the solid content of the RFL liquid was used. It was.

<Example 5>
A toothed belt having the same configuration as in Example 2 was prepared except that a treatment liquid in which the amount of the blocked isocyanate was 20 parts by mass with respect to 100 parts by mass of the solid content of the RFL liquid was used. It was.

<Example 6>
A toothed belt having the same configuration as in Example 2 was prepared except that a treatment liquid in which the amount of blocked isocyanate was 40 parts by mass with respect to 100 parts by mass of the solid content of the RFL liquid was used. It was.

<Example 7>
A toothed belt having the same configuration as in Example 2 was prepared except that a treatment liquid in which the amount of blocked isocyanate was 60 parts by mass with respect to 100 parts by mass of the solid content of the RFL liquid was used. It was.

<Example 8>
A toothed belt having the same configuration as in Example 2 was prepared except that a treatment liquid in which the amount of blocked isocyanate was 70 parts by mass with respect to 100 parts by mass of the solid content of the RFL liquid was used. It was.

<Example 9>
A toothed belt having the same configuration as in Example 2 was prepared except that a processing solution in which the latex was chlorosulfonated polyethylene (CSM) latex (trade name: CSM450, manufactured by Sumitomo Seika Co., Ltd.) was used. Example 9 was taken.

<Example 10>
A toothed belt having the same configuration as that of Example 2 except that a latex is 2,3-dichlorobutadiene polymer (2,3-DCB) latex (trade name: LH430, manufactured by Tosoh Corporation). This was made into Example 10.

<Example 11>
Toothed teeth having the same structure as in Example 2 except that a processing liquid which is a blocked isocyanate (trade name: Elastron BN-11 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) having a bond dissociation temperature of 150 ° C. is used. A belt was produced and designated as Example 11.

<Example 12>
A toothed belt having the same configuration as in Example 2 was produced, and this was designated as Example 12.

<Example 13>
A toothed belt having the same configuration as that of Example 12 was prepared except that the heat drying temperature after the treatment liquid was attached to the twill weave was set to 170 ° C., and this was designated as Example 13.

<Example 14>
A toothed belt having the same configuration as that of Example 2 except that the twill weave is dipped in the treatment liquid and then heated and dried to perform drying once and the basis weight of the RFL coating is about 15% by mass. This was made into Example 14.

<Comparative Example 1>
A toothed belt having the same configuration as that of Example 2 was prepared except that the RFL liquid itself to which PTFE and blocked isocyanate were not added was used as a treatment liquid.

<Comparative example 2>
A toothed belt having the same configuration as in Example 2 was prepared except that the amount of PTFE added was 50 parts by mass with respect to 100 parts by mass of the latex solid content of the RFL liquid, and a treatment liquid to which no blocked isocyanate was added was used. This was designated as Comparative Example 2.

<Comparative Example 3>
A toothed belt having the same configuration as in Example 1 was prepared except that a treatment liquid to which no blocked isocyanate was added was used, and this was designated as Comparative Example 3.

<Comparative example 4>
A toothed belt having the same configuration as in Example 2 was prepared except that a treatment liquid to which no blocked isocyanate was added was used, and this was designated as Comparative Example 4.

<Comparative Example 5>
A toothed belt having the same configuration as in Example 3 was prepared except that a treatment liquid to which no blocked isocyanate was added was used, and this was designated as Comparative Example 5.

<Comparative Example 6>
A toothed belt having the same configuration as in Example 2 was prepared except that the amount of PTFE added was 150 parts by mass with respect to 100 parts by mass of the latex solid content of the RFL liquid, and a treatment liquid to which no blocked isocyanate was added was used. This was designated as Comparative Example 6.

<Comparative Example 7>
A toothed belt having the same configuration as that of Example 2 was prepared except that a treatment liquid to which PTFE was not added was used.

<Comparative Example 8>
A toothed belt having the same configuration as in Example 2 was prepared except that a treatment liquid in which the amount of PTFE added was 50 parts by mass with respect to 100 parts by mass of the latex solid content of the RFL liquid was prepared. It was.

<Comparative Example 9>
A toothed belt having the same configuration as that of Example 2 was prepared except that a treatment liquid in which the amount of PTFE added was 150 parts by mass with respect to 100 parts by mass of the latex solid content of the RFL liquid was prepared. It was.

<Comparative Example 10>
A toothed belt having the same configuration as in Example 11 was prepared except that the heating and drying temperature after the treatment liquid was attached to the twill weave was 130 ° C., and this was designated as Comparative Example 10.

<Comparative Example 11>
A toothed belt having the same configuration as in Example 11 was prepared except that the heating and drying temperature after the treatment liquid was attached to the twill weave was 130 ° C., and this was designated as Comparative Example 11.

<Comparative Example 12>
A toothed belt having the same configuration as in Example 12 was prepared except that the heating and drying temperature after the treatment liquid was attached to the twill weave was 130 ° C., and this was designated as Comparative Example 12.

<Comparative Example 13>
Teeth having the same configuration as in Example 2 except that the basis weight of the RFL coating was about 15% by mass, and the surface of the reinforcing cloth on the toothed belt main body side was coated with rubber paste and then dried by heating. An attached belt was produced and this was designated as Comparative Example 13.

(Test evaluation method)
<Static adhesion test>
About each reinforcement cloth of Examples 1-14 and Comparative Examples 1-13, the peeling adhesion test was done according to JISK6854.

  In principle, the adhesive strength was evaluated as ◯ when the adhesive strength was 60 N / 25 mm or more and x when the adhesive strength was less than 60 N / 25 mm. However, it was set as evaluation of (triangle | delta) about what was 58.2N / 25mm.

<Abrasion resistance test>
FIG. 2 shows a pulley layout of the belt running test machine 20 used for the abrasion resistance test.

  The belt running test machine 20 includes a first driven toothed pulley 21 (16 teeth) provided at the uppermost position and a second driven toothed pulley 22 provided diagonally to the left of the first driven toothed pulley 21. (The number of teeth 16), the third driven toothed pulley 23 (the number of teeth 16) provided below the first driven toothed pulley 21 and obliquely below the second driven toothed pulley 22, and the second driven Driving toothed pulley 24 (number of teeth 16) provided on the right side of the toothed pulley 22 and obliquely below the first driven toothed pulley 21, the first driven toothed pulley 21 and the second driven toothed pulley. The pulley 22, the second driven toothed pulley 22 and the third driven toothed pulley 23, the third driven toothed pulley 23 and the driving toothed pulley 24, and the driving toothed pulley 24 and the first driven pulley 21. Provided at an intermediate position so that the winding angle on the back of the belt is 90 ° Four flat pulley (idler pulley) 25, 26, 27, 28 of the pulley diameter 45 mm, and a.

  In each of Examples 1 to 14 and Comparative Examples 1 to 13 having a belt width of 12.7 mm, the tooth portions mesh with the toothed pulleys 21 to 24, and the flat pulleys 25 to 28 come into contact with the back surface of the belt. In addition, after being wound around the toothed pulleys 21 to 24 and the flat pulleys 25 to 28, the third driven toothed pulley 23 is loaded with a dead weight of 441 N downward, and the driven toothed pulley 24 under an ambient temperature of 120 ° C. Was rotated in the clockwise direction at a rotational speed of 5500 rpm to run the belt.

  And what was able to run belt for 400 hours or more was evaluated as (circle), and what was not able to be evaluated was evaluated as x.

<Separation resistance and crack resistance test>
FIG. 3 shows a pulley layout of a belt running test machine 30 for a separation resistance and crack resistance test.

  This belt running test machine 30 has a large-diameter driven toothed pulley 31 (number of teeth 36), a small-diameter driving toothed pulley 32 (number of teeth 18) provided on the right side thereof, and a driven tooth between them. And a flat pulley (idler pulley) 33 having a pulley diameter of 52 mm provided slightly diagonally to the right of the attached pulley 31.

  For the toothed belt 10 having a belt width of 10 mm in each of Examples 1 to 14 and Comparative Examples 1 to 13, the toothed portion meshes with the driven toothed pulley 31 and the drive toothed pulley 32, and the flat pulley 33 is the back surface of the belt. Then, the driven toothed pulley 31 is loaded with a load torque of 29.4 Nm, and a dead weight is loaded on the driving toothed pulley 32 so that the belt tension of 980 N is loaded. The drive toothed pulley 32 was rotated clockwise at a rotational speed of 6000 rpm at 100 ° C. to run the belt.

  Then, in principle, the belt running for 1000 hours or more was evaluated as “good”, and the case where the breakage due to separation (separation) of the reinforcing cloth or the breakage due to the crack occurred in less than 1000 hours was evaluated as “poor”. However, those traveling for 922 hours were evaluated as Δ.

(Test evaluation results)
Table 3 shows the results of Examples 1-8 and Comparative Examples 1-9.

  According to Table 3, when Examples 1 to 3 in which blocked isocyanate is blended in the treatment liquid and Comparative Examples 3 to 5 in which block isocyanate is not blended into the treatment liquid are compared, the former is adhesive and peelable. It can be seen that it is superior to the latter in that it is difficult to occur.

  When comparing Examples 1 to 3 in which the blending amount of PTFE is 80 to 140 parts by weight with respect to 100 parts by weight of the latex solid content of the treatment liquid, and Comparative Examples 7 to 8 in which the blending amount of PTFE is 50 parts by weight or less. It can be seen that the former is superior to the latter in terms of wear resistance.

  When comparing Examples 1 to 3 in which the blending amount of PTFE is 80 to 140 parts by weight with respect to 100 parts by weight of the latex solid content of the treatment liquid and Comparative Example 9 in which the blending amount of PTFE is 150 parts by weight, the former is It can be seen that it is superior to the latter in terms of adhesion and resistance to peeling.

  Table 4 shows the results of Examples 11 to 13 and Comparative Examples 10 to 12.

  According to Table 4, Examples 11 to 13 in which the bond dissociation temperature of the blocked isocyanate is equal to or higher than the heating and drying temperature after the cloth is immersed in the treatment liquid, and the bond dissociation temperature of the blocked isocyanate are in the treatment liquid. Comparing with Comparative Examples 10 to 12 using a material having a temperature lower than the heat drying temperature after dipping the cloth, it can be seen that the former is superior to the latter in terms of adhesion and resistance to peeling.

  Table 5 shows the results of Examples 9, 10 and 14 and Comparative Example 13.

表５によれば、歯付ベルトのプーリ接触部をゴム糊で表面処理していない実施例２と、 プーリ接触部にゴム糊を含浸塗布した比較例１３と、を比較すると、前者は、耐クラック性の点で後者より優れることが分かる。

According to Table 5, when Example 2 in which the pulley contact portion of the toothed belt is not surface-treated with rubber paste and Comparative Example 13 in which the pulley contact portion is impregnated with rubber paste are compared, the former is It can be seen that it is superior to the latter in terms of cracking properties.

  As described above, the present invention is useful for the toothed belt and the manufacturing method thereof.

It is a perspective view of a toothed belt concerning an embodiment. It is a figure which shows the pulley layout of the belt running test machine for an abrasion resistance test. It is a figure which shows the pulley layout of the belt running test machine for a separation resistance and crack resistance test.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Toothed belt 11 Toothed belt main body 11a Tooth part 13 Reinforcement cloth

Claims (5)

The tooth side surface of a rubber toothed belt body provided with teeth at regular intervals in the belt length direction is covered with a reinforcing cloth, and the RFL coating provided so as to cover the reinforcing cloth is exposed on the belt surface. A method for manufacturing a toothed belt, comprising:
Preparing a treatment liquid in which 80 to 140 parts by mass of fluororesin powder and blocked isocyanate are added to resorcin / formalin / latex liquid with respect to 100 parts by mass of the latex solid content;
A step of forming the reinforcing cloth provided with an RFL film on the surface by drying by heating at a temperature of 150 ° C. or higher after the prepared treatment liquid is attached to the cloth;
Forming a toothed belt by heating and pressurizing and integrating a reinforcing cloth having an RFL film formed on the surface and a separately prepared uncrosslinked rubber composition for forming a toothed belt body; and
With
A method for producing a toothed belt, wherein the blocked isocyanate has a bond dissociation temperature equal to or higher than a heat drying temperature after the treatment liquid is attached to a cloth. In the manufacturing method of the toothed belt described in Claim 1,
Manufacturing of toothed belt, wherein the amount of the blocked isocyanate added to the resorcin / formalin / latex solution is 5 to 70 parts by mass with respect to 100 parts by mass of the solid content of the resorcin / formalin / latex solution. Method. In the manufacturing method of the toothed belt according to claim 1 or 2,
A method for producing a toothed belt, wherein the block isocyanate has a bond dissociation temperature higher than 150 ° C. In the manufacturing method of the toothed belt according to any one of claims 1 to 3,
As a latex of the resorcin / formalin / latex solution, a hydrogenated acrylonitrile butadiene methacrylic acid terpolymer latex, a chlorosulfonated polyethylene rubber latex, or a 2,3-dichlorobutadiene polymer latex is used. A method for manufacturing a belt. The tooth side surface of a rubber toothed belt body provided with teeth at regular intervals in the belt length direction is covered with a reinforcing cloth, and the RFL coating provided so as to cover the reinforcing cloth is exposed on the belt surface. Toothed belt,
A temperature of 150 ° C. or higher after a treatment liquid in which 80 to 140 parts by mass of fluororesin powder and blocked isocyanate are added to a resorcin / formalin / latex liquid with respect to 100 parts by mass of the latex solid content is attached to the cloth. It is formed by heating and pressurizing and integrating a reinforcing cloth having an RFL film formed on the surface thereof by heating and an unvulcanized rubber composition for forming a toothed belt body, which is separately prepared.
A toothed belt, wherein the block isocyanate has a bond dissociation temperature equal to or higher than a heat drying temperature after the treatment liquid is attached to a cloth.

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