JP2021021184A - Method for manufacturing core wire for transmission belt and method for manufacturing transmission belt, and treatment agent and kit for treatment - Google Patents

Abstract

To manufacture a core wire for transmission belt that contains no halogen and is excellent in heat-resistant adhesion to an elastomer embedding the core wire with a small environmental load.SOLUTION: A core wire for transmission belt is manufactured through a first treatment step of treating untreated yarns of a core wire for transmission belt with a first treatment agent containing a resin component (A) and obtaining a first treated yarn; and a second treatment step of treating the first treated yarn with a second treatment agent containing a condensate (B1) of resorcin and formaldehyde, an unmodified latex (B2) and an acid-modified diene-based polymer (3) and obtaining a second treated yarn. The resin component (A) may contain a modified epoxy resin (A1-1) modified with an elastic polymer, and may contain a condensate (A2-1) of resorcin and formaldehyde, a latex (A2-2) and a curing agent (A2-3) containing a polycarbodiimide resin having a plurality of carbodiimide groups.SELECTED DRAWING: None

Description

The present invention relates to a method for manufacturing a core wire used for a transmission belt, a method for manufacturing a transmission belt, a treatment agent, and a treatment kit.

As a means of power transmission, a transmission belt is used because of its quietness and high degree of freedom in layout. Examples of the transmission belt include a toothed belt which is an meshing transmission belt, a V belt which is a friction transmission belt, a V ribbed belt, and a flat belt. The V-belt is further classified into a wrapped V-belt in which the circumference of the belt is coated with a cloth, and a low-edge V-belt in which the friction transmission surface (V-shaped side surface) is formed of a rubber composition. As the low-edge V-belt, a low-edge cogged V-belt having irregularities on the inner peripheral side to improve flexibility, and a low-edge double-cogged V-belt having irregularities on the inner peripheral side and the outer peripheral side are also known. All transmission belts have a common structure in which a core wire (twisted cord in which fibers are twisted) is embedded in an elastomer. The core wire is usually subjected to an adhesive treatment and has an adhesive layer in order to improve the adhesiveness with the elastomer.

When these transmission belts are attached to an automobile engine or CVT (continuously variable transmission) and used, heat resistance may become a problem. In recent years, it has become difficult to dissipate heat due to the compact layout and simplification of the cooling mechanism, and the transmission belt is also required to have a high degree of heat resistance. Styrene butadiene rubber (SBR), chloroprene rubber (CR), hydride acrylonitrile butadiene rubber (HNBR), etc. have been widely used as elastomers constituting the transmission belt, but ethylene is particularly used in applications requiring high heat resistance. The use of -propylene-diene ternary copolymers (EPDM) is also increasing. Since EPDM does not contain a double bond in the main chain, it has excellent heat resistance, but vulcanization with sulfur is difficult, and cross-linking with an organic peroxide is usually performed.

EPDM crosslinked with an organic peroxide exhibits particularly high heat resistance, but has a problem that it is difficult to sufficiently improve the adhesiveness with the core wire. Therefore, it is customary to provide a plurality of adhesive layers on the core wire through a plurality of adhesive treatment steps. Typically, the first bath is impregnated with a resin component such as epoxy or isocyanate, the second bath is attached with a resorcin / formalin / latex mixture (RFL), which is a mixture of the resin component and the rubber component, and the third bath. A method of overcoating a rubber component with a rubber paste dissolved in an organic solvent is used. That is, the adhesive strength between the fiber and the elastomer is improved by gradually changing the adhesive layer from the resin component to the rubber component. However, when such a plurality of times of the bonding treatment is performed, the productivity is lowered and the influence on the environment due to the use of the organic solvent has become a problem, and improvement is required.

Therefore, maleic acid-modified polybutadiene and polycarbodiimide have been proposed as new adhesive components.

Japanese Patent Application Laid-Open No. 2005-511904 (Patent Document 1) describes a step of treating a fiber with a primer agent containing a ring-opened maleinated polybutadiene and a phenol derivative containing an electron-withdrawing group as a method for adhering the fiber to rubber. , A method including a step of treating with resorcin / formalin / latex preparation (RFL) is disclosed. Further, it is disclosed that the primer agent may be in the state of an aqueous solution or an organic solution, and that the primer agent may be added to RFL. As the rubber, HNBR, SBR, and standard Malaysian rubber are described, and in the examples, HNBR and SBR are used. Examples of the phenol derivative include 4-chlorophenol and 4-bromophenol, and a condensate of these substituted phenols with resorcin / formaldehyde and ethoxylated resorcin / formaldehyde.

Japanese Patent Application Laid-Open No. 2019-504130 (Patent Document 2) describes an aqueous adhesive composition containing water, an epoxy resin, a maleated polybutadiene polymer electrolyte, and a curing agent with respect to the adhesive treatment between the polymer matrix and the reinforcing fiber. It is disclosed (claim 15).

Japanese Unexamined Patent Publication No. 2017-82377 (Patent Document 3) describes a rubber composition containing a condensate of resorcin and formaldehyde, a rubber component containing a carboxyl-modified latex, and a curing agent containing a polycarbodiimide resin having a plurality of carbodiimide groups. A method for producing a transmission belt core wire treated with a treatment agent consisting of a hydrophilic solvent and a hydrophilic solvent is disclosed.

JP-A-2005-511904 (Claims 1, 17 and 19, paragraphs [0013] [0019], Examples) JP-A-2019-504130 (Claims 1 and 15) JP-A-2017-82377 (Claim 1)

In Patent Document 1, HNBR or SBR having relatively excellent adhesiveness is used as the elastomer, and EPDM having poor adhesiveness may not have sufficient adhesive strength. In addition, phenol derivatives containing electron-withdrawing groups, which are essential components, also contain halogens, which have a large environmental load. Patent Document 2 does not use a resorcin / formalin condensate (RF) or a resorcin / formalin / latex mixed solution (RFL), and is a one-bath treatment to smooth the difference in elastic modulus between the core wire and rubber. Since it cannot be connected and the mediation between the resin component and the rubber component is insufficient, sufficient adhesive strength cannot be obtained. Patent Document 3 has succeeded in improving the adhesive strength between the aramid fiber and EPDM, but it is still not sufficient for the recent demand for high heat-resistant adhesiveness.

An object of the present invention is to provide a method for manufacturing a transmission belt core wire having excellent heat-resistant adhesiveness to an elastomer in which a core wire is embedded with a small environmental load, a method for manufacturing the transmission belt, and a treatment agent and a treatment kit used for this method. There is.

Another object of the present invention is to provide a method for manufacturing a transmission belt core wire, a method for manufacturing a transmission belt, a treatment agent, and a treatment kit capable of improving the durability of the transmission belt.

As a result of diligent studies to achieve the above problems, the present inventors have treated the untreated yarn of the transmission belt core wire with the first treatment agent containing a resin component, and then the condensate of elastomer and formaldehyde, the unmodified latex. The present invention has been completed by finding that the treatment with a second treatment agent containing an acid-modified diene polymer has a small load on the environment and can improve the heat-resistant adhesiveness to the elastomer in which the core wire is embedded.

That is, the method for producing a transmission belt core wire of the present invention is the first processing step of treating the untreated yarn of the transmission belt core wire with the first treatment agent containing the resin component (A) to obtain the first treated yarn, resorcin. A second treatment yarn is obtained by treating the first treatment yarn with a second treatment agent containing a condensate of formaldehyde (B1), an unmodified latex (B2) and an acid-modified diene polymer (B3). Includes processing steps.

The production method of the present invention contains a modified epoxy resin (A1-1) in which the resin component (A) is modified with an elastic polymer, and the total ratio (solid content conversion) of the condensate (B1) and the unmodified latex (B2). ) Is 8 to 25% by mass in the second treatment agent, and the ratio (in terms of solid content) of the acid-modified diene polymer (B3) is 2.5 to 15% by mass in the second treatment agent. You may.

Further, the production method of the present invention is a curing agent (A2) in which the resin component (A) contains a condensate of resorcin and formaldehyde (A2-1), a latex (A2-2), and a polycarbodiimide resin having a plurality of carbodiimide groups. -3) is contained, and the total ratio (in terms of solid content) of the condensate (B1) and the unmodified latex (B2) is 5 to 25% by mass in the second treatment agent, and the acid-modified diene polymer (B3) The production method may be such that the ratio (in terms of solid content) is 1 to 15% by mass in the second treatment agent.

In the production method of the present invention, the acid-modified diene polymer (B3) may be carboxylic acid-modified polybutadiene. The mass (solid content equivalent) of the acid-modified diene polymer (B3) is 0.05 to 2 times the total mass (solid content equivalent) of the condensate (B1) and the unmodified latex (B2). You may. The first treatment agent and the second treatment agent may be halogen-free treatment agents. The production method of the present invention may be a method that does not include a step of overcoating with rubber glue.

In the present invention, it is a treatment agent for treating the untreated yarn of the transmission belt core wire, which is a condensate of resorcin and formaldehyde (B1), an unmodified latex (B2) and an acid-modified diene polymer (B3). ) Is also included. In this treatment agent, the transmission belt core wire may be a core wire in contact with a rubber layer containing an ethylene-α-olefin elastomer.

The present invention is a treatment kit for treating untreated yarn of a transmission belt core wire, wherein a first treatment agent containing a resin component (A), a condensate of resorcin and formaldehyde (B1), and not yet. A treatment kit containing a modified latex (B2) and a second treatment agent containing an acid-modified diene polymer (B3) is also included.

The present invention also includes a method for manufacturing a transmission belt, which includes a burying step of burying the core wire obtained by the manufacturing method in a rubber layer along the longitudinal direction of the belt. The rubber layer may contain an ethylene-α-olefin elastomer. The transmission belt may be a low edge V belt.

In the present invention, the untreated yarn of the transmission belt core wire is treated with a first treatment agent containing a resin component, and then a second treatment containing a condensate of resorcin and formaldehyde, an unmodified latex and an acid-modified diene-based polymer. Since it is treated with an agent, a transmission belt core wire having excellent heat-resistant adhesiveness to the elastomer in which the core wire is embedded can be manufactured with a small environmental load (for example, by reducing the amount of an organic solvent used). Therefore, it is possible to provide a core wire capable of improving the durability of the transmission belt by a method having a small load on the environment in which the amount of the organic solvent used is reduced.

FIG. 1 is a schematic cross-sectional view showing an example of a transmission belt including a transmission belt core wire obtained by the manufacturing method of the present invention. FIG. 2 is a schematic cross-sectional view showing another example of the transmission belt including the transmission belt guard wire obtained by the manufacturing method of the present invention. FIG. 3 is a schematic perspective view of the peeling test sample used in the peeling test of the example. FIG. 4 is a schematic view for explaining a measuring method of a peeling test of an example. FIG. 5 is a schematic view showing the layout of the endurance running test of the example.

<Manufacturing method of core wire>
In the present invention, the core wire is a condensate of resorcin and formaldehyde in the first treatment step of treating the untreated yarn of the transmission belt core wire with the first treatment agent containing the resin component (A) to obtain the first treated yarn. Manufactured through a second treatment step of treating the first treated yarn with a second treated agent containing (B1), an unmodified latex (B2) and an acid-modified diene polymer (B3) to obtain a second treated yarn. To.

[First processing step]
(Unprocessed thread for transmission belt core wire)
The raw material fibers constituting the untreated yarn for treatment with the first treatment agent include, for example, natural fibers (cotton, linen, etc.), recycled fibers (rayon, acetate, etc.), synthetic fibers (polyolefin fibers such as polyethylene and polypropylene). , Polystyrene fiber such as polystyrene, Fluorine fiber such as polytetrafluoroethylene, Acrylic fiber, Vinyl alcohol fiber such as polyvinyl alcohol, Polyamide fiber, Polyester fiber, Total aromatic polyester fiber, Aramid fiber, etc.), Inorganic fiber (Carbon fiber, glass fiber, etc.) and the like. These fibers can be used alone or in combination of two or more.

Among these fibers, polyester fibers whose main constituent unit is C _2-4 alkylene arylate such as ethylene terephthalate and ethylene-2,6-naphthalate [polyethylene terephthalate fiber (PET fiber), polyethylene na) from the viewpoint of high modulus. Polyalkylene allylate fibers such as phthalate fibers (PEN fibers) and polytrimethylene terephthalate fibers (PTT fibers)], synthetic fibers such as aramid fibers, and inorganic fibers such as carbon fibers are widely used, and have high tensile strength and high tensile strength. It is preferable to contain aramid fibers (aromatic polyamide fibers), and para-aramid fibers are particularly preferable, from the viewpoint of being able to meet the demands of tension and high load. Examples of the para-aramid fiber include polyparaphenylene terephthalamide fiber (for example, "Twaron (registered trademark)" of Teijin Limited, "Kevlar (registered trademark)" of Toray DuPont Co., Ltd.), and polypara. Examples thereof include copolymer fibers of phenylene terephthalamide and 3,4'-oxydiphenylene terephthalamide (for example, "Technora (registered trademark)" of Teijin Limited).

The untreated yarn for treatment with the first treatment agent may be in the state of untwisted yarn or in the state of twisted yarn (untreated twisted cord). Good. In the present invention, even a twisted cord has excellent impregnation property into the twisted cord (between monofilaments and / or multifilaments) of the first treatment agent, so that the adhesiveness between fibers can be improved.

In the raw yarn, the multifilament yarn preferably contains a monofilament yarn of a para-aramid fiber, and may contain a monofilament yarn of another fiber (polyester fiber or the like) if necessary. The ratio of the para-aramid fiber is 50% by mass or more (particularly 80 to 100% by mass) with respect to the entire monofilament yarn (multifilament yarn), and usually even if all the monofilament yarn is composed of the para-aramid fiber. Good.

The multifilament yarn may contain a plurality of monofilament yarns, and from the viewpoint of durability of the transmission belt, for example, 100 to 5000 yarns, preferably 300 to 2000 yarns, more preferably 600 to 1500 yarns, and most preferably 800 yarns. It may contain up to 1200 monofilament yarns.

The average fineness of the monofilament yarn may be, for example, 0.8 to 10 dtex, preferably 0.8 to 5 dtex, more preferably 1.1 to 3 dtex, and most preferably 1.3 to 2 dtex.

The twisted yarn cord may be a twisted yarn cord (single twisted yarn) in which at least one yarn is right-twisted (S-twisted) or left-twisted (Z-twisted), but from the viewpoint of strength, a plurality of yarns are twisted. A combined twisted cord is preferred.

The twisted cord obtained by twisting a plurality of raw yarns may be a twisted yarn cord (for example, various twisted yarns, piece twisted yarns, rung twisted yarns, etc.) obtained by twisting a plurality of single twisted yarns as a lower twisted yarn, and the single twisted yarn and the raw yarn may be used. It may be a twisted cord (for example, wall twisted yarn) in which (non-twisted yarn) is aligned and twisted. Further, the single twist direction (lower twist direction) and the upper twist direction may be either the same direction (lang twist) or the opposite direction (various twists). Of these, from the viewpoint of suppressing untwisting and being excellent in bending fatigue resistance, a twisted cord (twisted yarn or rung twisted yarn) in which a plurality of single-twisted yarns are top-twisted as a lower-twisted yarn is preferable, and the various-twisted yarn is particularly preferable. preferable.

The number of lower twisted yarns constituting these twisted yarn cords may be, for example, 2 to 5, preferably 2 to 4, and more preferably 2 to 3 yarns. The number of twists of the lower twist may be, for example, 20 to 300 times / m, preferably 30 to 200 times / m, more preferably 50 to 180 times / m, and most preferably 100 to 160 times / m. In the lower twist, the twist coefficient (TF) represented by the following formula (1) can be selected from the range of, for example, about 0.01 to 10, preferably about 1 to 6 for various twisted yarns and 0 for rung twisted yarns. .2 to 2 is preferable.

Twist coefficient (TF) = [number of twists (times / m) x √ total fineness (tex)] / 960 (1)

The number of twists of the upper twist is not particularly limited, and is, for example, 30 to 300 times / m, preferably 50 to 250 times / m, more preferably 150 to 230 times / m, and most preferably 180 to 220 times / m. You may. In the upper twist, the twist coefficient (TF) represented by the formula (1) can be selected from the range of, for example, about 0.01 to 10, preferably about 1 to 6 for various twisted yarns, and 2 to 2 for rung twisted yarns. About 5 is preferable.

The average diameter of the untreated twisted cord of the top-twisted transmission belt core wire is, for example, 0.2 to 3.5 mm, preferably 0.4 to 3 mm, and more preferably about 0.5 to 2.5 mm. May be good.

When the twisting structure of a twisted cord obtained by twisting a plurality of yarns is represented by (the number of yarns drawn in the lower twist) x (the number of yarns drawn in the lower twist at the time of upper twist), 1 x 2, 1 x 3, It may be a twisted yarn cord having a structure of 1 × 5, 2 × 3, 2 × 5, 3 × 5.

(First treatment agent)
The first treatment agent (or pretreatment agent) may be any treatment agent containing the resin component (A), and may be a treatment agent containing a conventional adhesive resin, but the heat resistance between the core wire and the elastomer From the viewpoint of improving adhesiveness, the first treatment agent (A1) containing a modified epoxy resin (A1-1) modified with an elastic polymer as the resin component (A), or resorcin and formaldehyde as the resin component (A) A first treatment agent (A2) containing a curing agent (A2-3) containing a condensate (A2-1), a latex (A2-2) and a polycarbodiimide resin having a plurality of carbodiimide groups is preferable.

(A1) First Treatment Agent The first treatment agent (A1) is a curing agent (A1-2) and an organic solvent (A1) in addition to a modified epoxy resin (A1-1) modified (toughened) with an elastic polymer. It is preferable to further contain -3).

(A1-1) Modified Epoxy Resin The modified epoxy resin (A1-1) is an epoxy resin obtained by modifying an epoxy group (glycidyl group or the like) derived from an epoxy resin having two or more epoxy groups in the molecule with an elastic polymer. It may be present, and a modified epoxy resin in which the end of the epoxy resin is modified with an elastic polymer is particularly preferable.

In such a modified epoxy resin, the elastic polymer is not particularly limited as long as it is a polymer softer than the epoxy resin, and various rubbers, elastomers, soft resins and the like can be used. For example, polybutadiene and nitrile rubber (NBR) can be used. , Carboxyl group-terminated NBR, polyurethane elastomer and the like. These elastic polymers can be used alone or in combination of two or more. Among these elastic polymers, NBR, carboxyl group-terminated NBR, and polyurethane elastomer are preferable, and NBR, which is a copolymer of butadiene and acrylonitrile, is particularly preferable from the viewpoint of adhesion to the elastomer in which the core wire is embedded.

The epoxy resin that is the base of the modified epoxy resin is not particularly limited, and is an aliphatic epoxy resin [diols such as aliphatic polyols (for example, ethylene glycol, propylene glycol, neopentyl glycol, polyethylene glycol, polypropylene glycol, glycerin, etc.). Triols, etc.) and halogen-containing epoxy compounds (eg, epichlorohydrin, etc.)], alicyclic epoxy resins (dicyclopentadiene type epoxy resins, etc.), aromatic epoxy resins, etc. May be good.

Examples of the aromatic epoxy resin include a bisphenol type epoxy resin [a reaction product of bisphenols (or an alkylene oxide adduct thereof) and a halogen-containing epoxy compound (such as epichlorohydrin)], and a naphthalene type epoxy resin (for example,). Diglycidyloxynaphthalene, etc.), benzenediol (eg, hydroquinone) and halogen-containing epoxy compound (epichlorohydrin, etc.), novolak-type epoxy resin [novolak resin (phenol novolak, cresol novolak, etc.) and halogen-containing epoxy Reactants with compounds (such as epichlorohydrin)] and the like.

In the bisphenol type epoxy resin, examples of bisphenols include biphenols (4,4'-dihydroxybiphenyl, etc.), bis (hydroxyphenyl) alkanes [for example, bis (4-hydroxyphenyl) methane (bisphenol F), 1 , 1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), 2,2-bis (4-hydroxy-3-methylphenyl) propane, 2,2- Bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) octane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, 2,2-bis (3-cyclohexyl) -4-Hydroxyphenyl) propane, bis (4-hydroxyphenyl) diphenylmethane, 2,2-bis (3,5-dichloro-4-hydroxyphenyl) propane, 2,2-bis (3,5-dibromo-4-) Bis (hydroxyphenyl) C _1-10 alcans such as hydroxyphenyl) propane], bis (hydroxyphenyl) cycloalcans (eg, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4) -Hydroxyphenyl) -3,3,5-trimethylcyclohexane), bis (hydroxyphenyl) ethers (eg 4,4'-dihydroxydiphenyl ether), bis (hydroxyphenyl) sulfones (eg 4) , 4'-dihydroxydiphenylsulfone, etc.), Bis (hydroxyphenyl) sulfoxides (eg, 4,4'-dihydroxydiphenylsulfoxide, etc.), Bis (hydroxyphenyl) sulfides (eg, 4,4'-dihydroxydiphenylsulfide, etc.) ) And so on.

These epoxy resins can be used alone or in combination of two or more. Among these epoxy resins, aromatic epoxy resins (reactants of polyhydric phenols and halogen-containing epoxy compounds, etc.) are preferable, and bisphenol type epoxy resins (bisphenol type epoxy resins) are particularly excellent in adhesion to para-aramid fibers. Bisphenol F type epoxy resin and / or bisphenol A type epoxy resin) is preferable.

A modified epoxy resin (A1-1) in which such an epoxy resin is modified with the elastic polymer can also be used alone or in combination of two or more.

The modified epoxy resin (A1-1) may usually have two or more epoxy groups in the molecule. The epoxy equivalent of such a modified epoxy resin depends on the type of epoxy resin, but is, for example, 100 to 1000 g / eq, preferably 120 to 800 g / eq, and more preferably 150 to 600 g / eq (particularly 200 to 500 g / eq). ) May be. If the epoxy equivalent is too small, the force for adhering the fibers may decrease, and if it is too large, the bending fatigue resistance of the belt may decrease.

The molecular weight of the modified epoxy resin [in the case of a polymer type, the average molecular weight (mass, weight average molecular weight, etc.)] is not particularly limited, and can be selected from, for example, about 300 to 3000. In the present invention, the weight average molecular weight may be measured in terms of polystyrene by, for example, gel permeation chromatography (GPC).

Examples of commercially available rubber (NBR) -modified epoxy resins include EPR-2000 (manufactured by ADEKA Corporation), EPR-4030 (manufactured by ADEKA Corporation), and EPR-4033 (manufactured by ADEKA Corporation). EPB-13 (manufactured by Nippon Soda Co., Ltd.) and the like can be mentioned.

(A1-2) Curing Agent The curing agent (A1-2) may be a curing agent commonly used as a curing agent for epoxy resins. Moreover, the curing agent may be a latent curing agent.

Of these curing agents, tertiary amines are preferable from the viewpoint of handleability and the like. Examples of tertiary amines include aliphatic amines such as triethylamine, triethanolamine, and dimethylaminoethanol, benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl) phenol, and 1,8-diazabicyclo [5]. .4.0] Amine having an aromatic ring such as undecene-1 can be mentioned. These tertiary amines can be used alone or in combination of two or more. Among these tertiary amines, tertiary amines having an aromatic ring such as 2,4,6-tris (dimethylaminomethyl) phenol are particularly preferable.

The ratio of the curing agent may be 10 parts by mass or less with respect to 100 parts by mass of the modified epoxy resin, for example, 1 to 10 parts by mass, preferably 2 to 8 parts by mass, and more preferably 3 to 6 parts by mass. .. If the proportion of the curing agent is too small, the adhesiveness between fibers may be lowered, and if it is too large, the adhesiveness to the elastomer and the flexibility of the core wire may be lowered.

(A1-3) Organic Solvent The first treatment agent (A1) can reduce the viscosity of the treatment agent by containing the organic solvent (A1-3), and the modified epoxy resin (A1-1) and the curing agent (A1). Since -2) can be dissolved or uniformly dispersed in an organic solvent, the modified epoxy resin (A1-1) and the curing agent (A1-2) can be uniformly impregnated between the fibers of the twisted cord.

Examples of the organic solvent (A1-3) include chain ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), cyclic ketones (cyclohexanone, etc.), chain ethers (diethyl ether, etc.), and cyclic ethers (dioxane). , Tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons (cyclohexane, etc.), aromatic hydrocarbons (toluene, xylene, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.) ), aliphatic alcohols (ethanol, isopropanol, butanol, etc.), alicyclic alcohols (cyclohexanol, etc.), polyhydric alcohols (ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, etc.), cellosolves (methylcellosolve, ethyl, etc.) Examples thereof include cellosolves (such as propylene glycol monomethyl ether), cellosolve acetates, sulfoxides (such as dimethyl sulfoxide), and amides (such as dimethylformamide and dimethylacetamide).

These organic solvents can be used alone or in combination of two or more. Among these organic solvents, aromatic hydrocarbons such as toluene are widely used.

The solid content (active ingredient) concentration of the first treatment agent may be, for example, 1 to 70% by mass, preferably 3 to 50% by mass, more preferably 4 to 40% by mass, and most preferably 5 to 30% by mass. Good. If the solid content concentration is too low, the adhesive force between the fibers may decrease, and if it is too high, the impregnation property of the treatment agent between the fibers may decrease.

(A1-4) Other Additives The first treatment agent (A1) is a general-purpose epoxy resin that has not been modified with an elastic polymer as another additive (A1-4) as long as the effects of the present invention are not impaired. (Bisphenol type epoxy resin, etc.), reactive diluents (hardening accelerator, low viscosity polyglycidyl ether, monoglycidyl ether, etc.), conventional additives (adhesive improver, filler, antiaging agent, lubricant, adhesive It may contain an excipient, a stabilizer, a coupling agent, a plasticizer, a colorant, etc.).

The ratio of the other additive (A1-4) may be 30% by mass or less with respect to the entire first treatment agent (A1), for example, 0.01 to 30% by mass, preferably 0.05 to 20%. It is by mass, more preferably 0.1 to 10% by mass.

The first treatment agent (A1) preferably contains no halogen, and particularly preferably does not contain halogen, from the viewpoint of reducing the environmental load. In the present application, "substantially free of halogen" means that halogen is not intentionally contained, and specifically, 0.5% by mass of the first treatment agent (A1) as an unavoidable impurity. If it is as follows, it means that the mixing of halogen is allowed.

(A2) First Treatment Agent The first treatment agent (A2) is a curing agent containing a condensate of resorcin and formaldehyde (A2-1), a latex (A2-2), and a polycarbodiimide resin having a plurality of carbodiimide groups (A2). In addition to A2-3), it is preferable to further contain a hydrophilic solvent (A2-4).

(A2-1) Condensate of resorcin and formaldehyde (RF condensate)
The first treatment agent (A2) contains a condensate (RF condensate) (A2-1) of resorcin (R) and formaldehyde (F). The RF condensate (A2-1) has excellent compatibility with latex, particularly carboxyl-modified latex, and can form a flexible film.

The RF condensate (A2-1) is not particularly limited, and examples thereof include a novolak type, a resol type, and a combination thereof.

The RF condensate (A2-1) can be obtained, for example, by reacting resorcin with formaldehyde in the presence of water and a base catalyst (alkali metal salt such as sodium hydroxide; alkaline earth metal salt; ammonia, etc.). It may be a reaction product (eg, initial condensate or prepolymer). Aromatic monools such as phenol and cresol may be used in combination with resorcin, and aromatic diols such as catechol and hydroquinone or aromatic polyols may be used in combination with resorcin, as long as the effects of the present invention are not impaired. Further, as the formaldehyde, a condensate of formaldehyde (for example, trioxane, paraformaldehyde, etc.) may be used, or an aqueous solution of formaldehyde (formalin, etc.) may be used.

The ratio (usage ratio) of resorcin and formaldehyde can be selected from the range of, for example, the former / the latter (molar ratio) = 1 / 0.1 to 1/5, and when a mixture of resorcin type and novolak type is produced. The molar ratio of the two is, for example, the former / the latter = 1 / 0.3 to 1/1, preferably 1 / 0.4 to 1 / 0.95, and more preferably 1 / 0.5 to 1/0. It may be about 9. If the proportion of formaldehyde is too high, there is a risk of contamination by residual formaldehyde, and conversely, if it is too low, the content of the resol-type RF condensate may be insufficient and the mechanical properties of the cured product may deteriorate.

The ratio of the RF condensate (A2-1) (including latex, solid content equivalent ratio, the same applies hereinafter) is, for example, 1 to 100 parts by mass, preferably 3 to 100 parts by mass with respect to 100 parts by mass of latex (A2-2). It is 80 parts by mass, more preferably 5 to 50 parts by mass, more preferably 10 to 40 parts by mass, and most preferably 20 to 30 parts by mass. If the proportion of the RF condensate (A2-1) is too large, the produced cured product tends to be rigid, and the flexibility may decrease. On the other hand, if the proportion of the RF condensate (A2-1) is too small, the mechanical properties of the cured product may deteriorate.

(A2-2) Latex Latex (A2-2) can utilize a conventional rubber component. The conventional rubber component is not particularly limited, and for example, diene rubber [natural rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber (SBR latex), styrene-butadiene-vinylpyridine ternary copolymer latex (VP latex). ), Acrylonitrile butadiene rubber (NBR latex), hydride nitrile rubber (H-NBR latex), etc.], olefin rubber [for example, ethylene-propylene copolymer (EPM), ethylene-propylene-diene ternary copolymer ( Ethylene-α-olefin rubber (ethylene-α-olefin elastomer) such as EPDM); polyoctenylene rubber; olefin-vinyl ester copolymer such as ethylene-vinyl acetate copolymer rubber (EAM)], acrylic Examples include rubber, silicone-based rubber, and urethane-based rubber.

Further, the latex (A2-2) may be a carboxyl-modified latex in which these rubber components are modified with a carboxyl group. The method for introducing a carboxyl group into the rubber component is not particularly limited, but usually, a method for copolymerizing an unsaturated carboxylic acid having an ethylenically unsaturated bond is used. Examples of such unsaturated carboxylic acids include unsaturated monocarboxylic acids such as (meth) acrylic acid and crotonic acid; and unsaturated polyvalent carboxylic acids such as fumaric acid, maleic acid, itaconic acid, and butentricarboxylic acid; Examples thereof include partial esterified products of unsaturated polyvalent carboxylic acids such as monoethyl acid and monomethyl itaconic acid. These unsaturated carboxylic acids can be used alone or in combination of two or more.

Specific examples of the carboxyl-modified latex include carboxyl-modified acrylonitrile-butadiene copolymer latex (XNBR latex), carboxyl-modified hydrogenated acrylonitrile-butadiene copolymer latex (XHNBR latex), and carboxyl-modified styrene-butadiene copolymer latex. (XSBR latex), carboxyl-modified styrene-butadiene-vinylpyridine copolymer latex (XVP latex) and the like can be mentioned.

These latexes can be used alone or in combination of two or more. Of these, carboxyl-modified latex is preferable because it can improve the strength of the film formed by the first treatment agent (A2) and the flexibility of latex can also be improved, and XNBR is excellent in adhesiveness to the elastomer. Latex is particularly preferred.

(A2-3) Curing Agent The curing agent (A2-3) contains a polycarbodiimide resin having a plurality of carbodiimide groups. In particular, when the latex (A2-2) is a carboxyl-modified latex, the polycarbodiimide resin is used as a curing agent to crosslink and reinforce the latex by a cross-linking reaction between the carboxyl group and the carbodiimide group of the latex. The coating can be toughened. Furthermore, when the core wire contains aramid fibers, the following chemical structural adhesions (chemical bonds and intermolecular interactions) act between the polycarbodiimide resin and the aramid fibers to firmly fix the aramid fibers. it can.

(1) Chemical adhesion in which the carbodiimide group of the polycarbodiimide resin chemically reacts with the residual amino group and / or the carboxyl group of the aramid fiber (2) The molecule of the carbodiimide group of the polycarbodiimide resin and the amide bond of the aramid fiber Chemical adhesion due to interaction (hydrogen bond).

The polycarbodiimide resin may have a plurality of carbodiimide groups (-N = C = N-) and is not particularly limited, but for example, a resin having a repeating unit represented by the following formula (I) (or a resin). Oligomer) and the like.

-(N = C = N-R)-(I)
(In the formula, R indicates a divalent hydrocarbon group which may have a substituent)

In R of the formula (I), the divalent hydrocarbon group includes an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group and the like.

Examples of the aliphatic hydrocarbon group include an alkylene group, an alkenylene group, and an alkynylene group. Examples of the alkylene group include C ₁ such as methylene group, ethylene group, propylene group, trimethylene group, butylene group, tetramethylene group, hexamethylene group, isohexylene group, octamethylene group, isooctylene group, decamethylene group and dodecamethylene group. _-20 alkylene group and the like can be mentioned. Examples of the alkenylene group include a C _2-20 alkenylene group such as a vinylene group, an arylene group, a metalylene group, a 1-propenylene group, an isopropenylene group, a butenylene group, a pentenylene group and a hexenylene group. Examples of the alkynylene group include a C _2-20 alkynylene group such as an ethynylene group and a propynylene group.

Examples of the alicyclic hydrocarbon group include C _3-12 cycloalkylene groups such as cyclopropylene group, cyclobutylene group, cyclopentylene group, cyclohexylene group and cyclododecane-diyl group; C such as cyclohexenylene group. _3-12 Cycloalkenylene group; C _4-15 crosslinked cyclic hydrocarbon group such as bicycloheptanylene group, bicycloheptenylene group and the like can be mentioned.

Examples of the aromatic hydrocarbon group include a C _6-14 arylene group such as a phenylene group and a naphthylene group.

Further, the hydrocarbon group may be, for example, a group in which two or more kinds selected from an aliphatic hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group are bonded. Examples of the group in which the aliphatic hydrocarbon group and the alicyclic hydrocarbon group are bonded include a cyclohexylene methylene group, a methylenecyclohexylene group, a dicyclohexylmethane-4,4'-diyl group, and a dicyclohexylpropane-4,4. Examples thereof include a dicycloalkylalkane-diyl group such as a'-diyl group. Examples of the group in which the aliphatic hydrocarbon group and the aromatic hydrocarbon group are bonded include a diaryl such as a trilene group, a xylylene group, a diphenylmethane-4,4'-diyl group, and a diphenylpropane-4,4'-diyl group. Examples thereof include an alkane-diyl group.

Among these hydrocarbon groups, C _1-10 alkylene groups such as methylene group and hexamethylene group, C _5-8 cycloalkylene group such as cyclohexylene group, C _6-10 arylene group such as phenylene group, and these A combination of hydrocarbon groups (eg, a combination of a C _1-10 alkylene group such as a dicyclohexylmethane-4,4'-diyl group and a C _5-8 cycloalkylene group) is preferred.

Examples of the substituent of these hydrocarbon groups include an alkyl group (C _1-10 alkyl group such as methyl group, ethyl group, propyl group, isopropyl group and butyl group), alkenyl group, cycloalkyl group and aryl group. Halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), oxo group, hydroxyl group, carbonyl group, carboxyl group, amino group, alkoxy group (C _1-6 alkoxy group such as methoxy group, ethoxy group, etc.) , Acyl group, mercapto group, sulfonic acid (salt) group, alkylthio group, epoxy group, cyano group, phosphoric acid group and the like. These substituents can be used alone or in combination of two or more. Among these substituents, C _1-4 alkyl groups such as isopropyl groups and hydrophilic groups such as hydroxyl groups, carboxyl groups, amino groups and sulfonic acid (salt) groups are widely used.

The polycarbodiimide resin may be a homopolymer in which the group R constituting the repeating unit is the same hydrocarbon group, or may be a copolymer in which different hydrocarbon groups are used.

The polycarbodiimide resin is preferably a resin capable of forming micelles in the first treatment agent (A2) containing a hydrophilic solvent (A2-4) (particularly water) described later.

Since the polycarbodiimide resin is usually produced by condensation of an isocyanate compound, the terminal group of the polycarbodiimide resin may be an isocyanate group, and at least a part of the isocyanate group is sealed with a sequestering agent. There may be. The sequestering agent may be a compound having a reactive group with an isocyanate group (amine, alcohol, etc.), but a sequestering agent having a hydrophilic group is preferable from the viewpoint of imparting hydrophilicity to the polycarbodiimide resin. Such sequestering agents, for example, di _{C 1-4} alkylamino _{C 1-4} alkanols such as dimethylaminoethanol, di _{C 1-4} alkylamino _{C 1-4} alkyl amines such as dimethylaminopropylamine, hydroxy propane Examples thereof include hydroxy C _1-4 alkane sulfonates such as sodium sulfonate and C _2-4 alkylene glycol mono C _1-4 alkyl ethers such as ethylene glycol monoethyl ether.

Among these polycarbodiimide resins, they are water-based (water-soluble or water-soluble) because they have excellent dispersibility in the first treatment agent (A2) containing a hydrophilic solvent (A2-4) (particularly water) and can form micelles. Dispersibility) Polycarbodiimide resin is preferable. In the aqueous polycarbodiimide resin, the repeating unit may have the hydrophilic group, or the terminal group may be sealed with the hydrophilic group, but the terminal group is excellent in the reactivity of the carbodiimide group. May be a polycarbodiimide resin sealed with a hydrophilic group. When an aqueous polycarbodiimide resin is used as the polycarbodiimide resin, the aqueous polycarbodiimide resin can form micelles in the treatment agent, can suppress the reactivity of the carbodiimide group in a hydrophilic solvent (particularly in water), and is dried. The reactivity is restored by this, and it can also function as a cross-linking agent.

Even if the polycarbodiimide resin does not have a hydrophilic group, micelles can be formed in the first treatment agent by combining with a surfactant. As the surfactant, conventional anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants and the like can be used.

The polycarbodiimide resin preferably has a carbodiimide group in a predetermined ratio in the molecule because it enhances the reactivity of the carboxyl-modified latex with the carboxyl group and can efficiently crosslink the carboxyl-modified latex. Specifically, the chemical formula amount (NCN equivalent) per mole of the carbodiimide group of the polycarbodiimide resin may be 600 or less, for example, 200 to 600, preferably 250 to 500, more preferably 300 to 450, and most preferably 350. ~ 450. If the NCN equivalent is too large, the reactivity with the carboxyl-modified latex may decrease.

The degree of polymerization of the polycarbodiimide resin may be, for example, 2 or more, for example, 2 to 100, preferably 3 to 50, more preferably 5 to 30, and most preferably 6 to 10.

As the polycarbodiimide resin, a commercially available polycarbodiimide resin can be used. For example, a commercially available "carbodilite (registered trademark)" series (E-02, E-03A) manufactured by Nisshinbo Chemical Co., Ltd. as a cross-linking agent for an aqueous resin can be used. E-05 etc.) can be used.

The curing agent (A2-3) may contain other conventional curing agents as long as the effects of the present invention are not impaired. As the other curing agent, a curing agent having a plurality of groups capable of reacting with a carboxyl group is preferable, and polyisocyanates, polyols, polyamines and the like can be mentioned. Of these, blocked isocyanate (blocked polyisocyanate), which is a compound in which the isocyanate group of the polyisocyanate is masked with a blocking agent to suppress the reaction, is preferable from the viewpoint of excellent permeability of the treatment agent between fibers. As the blocked isocyanate, conventional blocked isocyanate can be used, and an aliphatic polyisocyanate or a derivative thereof [for example, hexamethylene diisocyanate (HDI) or a trimer thereof, etc.], an aromatic polyisocyanate [tolylene diisocyanate (TDI), xylyl) Range isocyanate (XDI), etc.] are widely used. As the blocking agent (protective agent), for example, oximes and lactams are widely used. The dissociation temperature of the blocked isocyanate may be higher than the temperature (normal temperature) in the dipping treatment with the first treatment agent and lower than the heat treatment temperature after the dipping treatment, but is, for example, 80 to 220 ° C, preferably 100 to 200 ° C. More preferably, it is 120 to 180 ° C. The ratio of the blocked isocyanate may be 1000 parts by mass or less with respect to 100 parts by mass of the polycarbodiimide resin, for example, 10 to 500 parts by mass, preferably 30 to 300 parts by mass, and more preferably 50 to 200 parts by mass. ..

The ratio of the polycarbodiimide resin to the whole curing agent (A2-3) is, for example, 10% by mass or more, preferably 50% by mass or more, and more preferably 80% by mass or more (particularly 90% by mass or more). , 100% by mass (polycarbodiimide resin only).

The ratio (ratio in terms of solid content) of the curing agent (A2-3) (particularly polycarbodiimide resin) is about 0.1 to 20 parts by mass with respect to 100 parts by mass of latex (A2-2) (particularly carboxyl-modified latex). It can be selected from the range of, for example, 0.2 to 10 parts by mass, preferably 0.3 to 8 parts by mass, more preferably 0.5 to 5 parts by mass, and most preferably 0.8 to 3 parts by mass. If the proportion of the curing agent (A2-3) is too small, the adhesive force between the fibers may decrease, and if it is too large, the flexibility may decrease.

(A2-4) Hydrophilic solvent In the present invention, since the solvent of the first treatment agent (A2) is the hydrophilic solvent (A2-4), the load on the environment is higher than that of the organic solvent (particularly, the hydrophobic solvent). Is small. Examples of the hydrophilic solvent (A2-4) include water, lower aliphatic alcohols (eg, C _1-4 alkyl alcohols such as ethanol and isopropanol), alkylene glycols (eg, ethylene glycol, diethylene glycol, propylene glycol and the like). ), Ketones (acetone, etc.) and the like. These hydrophilic solvents can be used alone or in combination of two or more. Of these, a hydrophilic solvent containing water is preferable, and water alone is particularly preferable.

The solid content (active ingredient) concentration in the first treatment agent (A2) is, for example, 1 to 70% by mass, preferably 5 to 60% by mass, more preferably 10 to 50% by mass, and most preferably 15 to 40% by mass. It may be. If the solid content concentration is too low, the fibers may not be firmly adhered to each other, and if the solid content concentration is too high, solid content may be formed on the surface of the core wire after the treatment.

(A2-5) Other Additives The first treatment agent (A2) is a reactive binder resin (epoxy compound, etc.) as another additive (A2-5) as long as the effects of the present invention are not impaired. Organic solvents (such as reactive diluents such as monocarbodiimide compounds), conventional additives (hardening accelerators, adhesive improvers, fillers, anti-aging agents, lubricants, tackifiers, stabilizers, coupling agents, plastics Agents, colorants, etc.) may be included.

The ratio of the other additive (A2-5) may be 30% by mass or less with respect to the entire first treatment agent (A2), for example, 0.01 to 30% by mass, preferably 0.05 to 20%. It is by mass, more preferably 0.1 to 10% by mass.

The first treatment agent (A2) preferably contains no halogen, and particularly preferably does not contain halogen, from the viewpoint of reducing the environmental load.

(Processing method)
The method for preparing the first treatment agent is not particularly limited, and both the first treatment agent (A1) and the first treatment agent (A2) may be prepared, for example, by stirring and mixing all at once, or may be divided. It may be prepared by stirring and mixing.

The method of treating the untreated yarn of the transmission belt core wire with the first treatment agent is not particularly limited, and examples thereof include spraying, coating, and dipping. Of these treatment methods, immersion is widely used. The immersion time is, for example, 1 to 120 seconds, preferably 10 to 60 seconds, and more preferably 20 to 40 seconds.

After treating the untreated yarn of the transmission belt core wire with the first treatment agent, it may be dried if necessary. The drying temperature can be selected from the range of, for example, about 100 to 250 ° C., and the drying temperature of the first treatment agent (A1) may be preferably 150 to 240 ° C., more preferably 170 to 210 ° C., and the first The drying temperature of the treatment agent (A2) may be preferably 120 to 200 ° C., more preferably 130 to 180 ° C. The drying time may be, for example, 5 seconds to 10 minutes, preferably 10 seconds to 5 minutes, and more preferably 20 seconds to 1 minute. Further, the drying may be performed by applying tension to the untreated yarn of the transmission belt core wire. The tension may be, for example, about 5 to 15 N, preferably about 10 to 15 N. When it is dried under the action of tension, the treatment agent can be easily adapted to the untreated yarn of the transmission belt core wire, the twisting unevenness can be reduced, and the variation in the diameter of the twisted yarn cord caused by the twisting unevenness can be reduced.

The average thickness of the film formed by the first treatment agent can be selected from the range of, for example, about 0.001 to 20 μm, and the average thickness of the film formed by the first treatment agent (A1) is, for example, 0.001 to 5 μm. It may be preferably 0.01 to 3 μm, more preferably 0.05 to 2 μm, and the average thickness of the coating film formed by the first treatment agent (A2) is, for example, 0.1 to 15 μm, preferably 1. It is ~ 12 μm, more preferably 5-10 μm. If the thickness is too thin, the adhesive strength between the core wire and the elastomer may decrease, and if the thickness is too thick, the shear adhesive strength between the core wire and the elastomer may decrease.

In the present application, the thickness of the coating film can be measured by a method using a scanning electron microscope. Specifically, it can be measured by observing the cross section of the processing cord of the core wire treated with the processing agent using a scanning electron microscope, measuring the thickness of the coating film at arbitrary 10 points, and obtaining the average value.

[Second processing step]
In the second treatment step, when the first treated yarn is a twisted yarn cord, the second treated agent forms a film on the film of the first treated agent, and the binding property of the twisted yarn cord and the adhesion with the first treated yarn In addition to improving the property, the adhesiveness with the elastomer constituting the belt can also be improved. In the present invention, since the two-bath treatment is a combination of the first treatment agent and the second treatment agent, it is one factor that the adhesive strength can be improved by being able to gently connect the difference in elastic modulus between the core wire and the rubber. It can be estimated that it is.

(Second treatment agent)
The second treatment agent contains a condensate of resorcin and formaldehyde (B1), an unmodified latex (B2) and an acid-modified diene polymer (B3).

(B1) Condensate of resorcin and formaldehyde The condensate of resorcin and formaldehyde (B1) is an RF condensate exemplified as the RF condensate (A2-1) of the first treatment agent (A2), including preferred embodiments. You can choose from.

The ratio of the RF condensate (B1) (ratio in terms of solid content) is, for example, 1 to 100 parts by mass, preferably 10 to 80 parts by mass, and more preferably 20 to 100 parts by mass with respect to 100 parts by mass of the unmodified latex (B2). It is 70 parts by mass, more preferably 30 to 60 parts by mass, and most preferably 40 to 50 parts by mass. If the proportion of the RF condensate (B1) is too large, the produced cured product tends to be rigid, and the flexibility may decrease. On the other hand, if the proportion of the RF condensate (B1) is too small, the mechanical properties of the cured product may deteriorate.

(B2) Unmodified Latex As the unmodified latex (B2), a conventional rubber component exemplified as the latex (A2-2) of the first treatment agent (A2) can be used. The rubber component can be used alone or in combination of two or more. Among the rubber components, a diene-based rubber is preferable, and a diene-based rubber having a vinylpyridine skeleton is particularly preferable, from the viewpoint of excellent adhesiveness to the first treatment agent and the elastomer.

As the diene rubber having a vinylpyridine skeleton, in addition to butadiene and vinylpyridine, conventional copolymerization components [styrene, α-methylstyrene, chlorostyrene, (meth) acrylonitrile, (meth) acrylic acid, (meth) acrylic Acid alkyl ester, etc.] may be included. Of these, aromatic vinyl-based monomers such as styrene are widely used. That is, as the vinylpyridine-butadiene copolymer, for example, a butadiene-vinylpyridine copolymer, a styrene-butadiene-vinylpyridine ternary copolymer (VP latex), and the like are widely used.

The total concentration of the RF condensate (B1) and the unmodified latex (B2) in the second treatment agent can be selected from the range of about 5 to 25% by mass.

When the first treatment agent is the first treatment agent (A1), the total concentration (concentration in terms of solid mass) of the RF condensate (B1) and the unmodified latex (B2) in the second treatment agent is, for example, 7. ~ 30% by mass (for example, 8 to 25% by mass), preferably 10 to 25% by mass, more preferably 11 to 20% by mass (for example, 11.5 to 18% by mass), more preferably 13 to 20% by mass, most preferably. It is preferably 15 to 18% by mass. If the total concentration is too low, the adhesiveness may decrease, and if it is too high, the film may be too thick, or the film may peel off due to friction with the rollers during the core wire bonding process, resulting in slag. It may occur and it may be difficult to continue the process.

When the first treatment agent is the first treatment agent (A2), the total concentration (concentration in terms of solid mass) of the RF condensate (B1) and the unmodified latex (B2) in the second treatment agent is, for example, 5. It is ~ 25% by mass, preferably 5.2 to 15% by mass, more preferably 5.5 to 10% by mass, more preferably 6 to 8% by mass, and most preferably 6.5 to 7% by mass. If the total concentration is too low, the adhesiveness may decrease, and if it is too high, the film may be too thick, or the film may peel off due to friction with the rollers during the core wire bonding process, resulting in slag. It may occur and it may be difficult to continue the process.

Although the detailed mechanism is unknown, the interaction between the first treatment agent (A2) and the second treatment agent contained in the first treatment yarn is larger than that of the first treatment agent (A1). The first treatment agent (A2) has a greater effect of improving the adhesive strength than the first treatment agent (A1). Therefore, regarding the total concentration of the RF condensate (B1) and the unmodified latex (B2), even if the first treatment agent (A2) is lower than the first treatment agent (A1), sufficient adhesive strength can be obtained, and the total concentration. The lower limit value of can be lowered to 5% by mass, and the material cost can be reduced. Further, as the first treatment agent (A2), a hydrophilic solvent can be used for both the first treatment agent and the second treatment agent, and no organic solvent is used, so that the effect of reducing the environmental load is large.

(B3) Acid-Modified Diene Polymer The second treatment agent further contains an acid-modified diene polymer (B3) in addition to the RF condensate (B1) and the unmodified latex (B2), and these components are specified. By combining at the ratio of, the adhesion to the first treated yarn (particularly, the coating film formed by the first treated agent) can be improved, and the adhesiveness of the belt to the elastomer can also be improved.

The acid-modified diene-based polymer (B3) may be any diene-based polymer modified with a carboxylic acid or acid anhydride, and more particularly, a diene-based polymer having a carboxyl group and / or an acid anhydride group. Just do it. The method of modification with an acid may be such that a carboxyl group and / or an acid anhydride group is introduced into the skeleton of the diene polymer, and is not particularly limited, but from the viewpoint of mechanical properties and the like, the carboxyl group and / or acid anhydride is used. A method of introducing a monomer having a physical group by copolymerization is preferable. The form of copolymerization may be random copolymerization, block copolymerization, or the like, but graft copolymerization is preferable from the viewpoint of improving the adhesiveness with the elastomer.

Examples of the diene polymer include polybutadiene, polyisoprene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer and the like. These diene-based polymers can be used alone or in combination of two or more. Of these, a polybutadiene polymer containing a butadiene unit is preferable, and polybutadiene (1,4-butadiene homopolymer) is particularly preferable.

Examples of the monomer having a carboxyl group and / or an acid anhydride group include unsaturated monocarboxylic acids [for example, (meth) acrylic acid, crotonic acid, isocrotonic acid, angelic acid, etc.], unsaturated dicarboxylic acids or the like. Acid anhydrides [eg, (anhydrous) maleic acid, fumaric acid, (anhydrous) citraconic acid, (anhydrous) itaconic acid, mesaconic acid, etc.] and the like can be mentioned. These monomers can be used alone or in combination of two or more. Among these monomers, unsaturated monocarboxylic acids such as (meth) acrylic acid, unsaturated dicarboxylic acids such as (maleic anhydride) maleic anhydride, or acid anhydrides thereof are preferable from the viewpoint of improving adhesiveness, and (anhydrous). Maleic anhydride is particularly preferred. Further, the diene-based polymer modified with a dicarboxylic acid may be a polymer obtained by opening the acid anhydride group of the diene-based polymer modified with an anhydride carboxylic acid. Further, the carboxyl group may be in the form of a salt neutralized with an alkali (for example, an alkali metal such as lithium, sodium or potassium, or an alkaline earth metal such as calcium or magnesium).

The ratio of the monomer (monomer unit in the acid-modified diene polymer) may be 1 mol or more, for example, 1 to 30 mol, preferably 3 to 3 to 1 mol of the diene polymer. It is 25 mol, more preferably 5 to 20 mol, more preferably 7 to 15 mol, and most preferably 9 to 13 mol. If the proportion of the monomer is too small, the adhesiveness with the elastomer may decrease.

The acid value of the acid-modified diene polymer (B3) may be 10 mgKOH / g or more, for example, 10 to 500 mgKOH / g, preferably 20 to 300 mgKOH / g, more preferably 30 to 200 mgKOH / g, and most preferably. It is 35 to 150 mgKOH / g. If the acid value is too low, the adhesiveness with the elastomer may decrease.

The number average molecular weight of the acid-modified diene polymer (B3) is, for example, 1000 to 300,000, preferably 1500 to 10000, more preferably 2000 to 10000, and more preferably 3000 in terms of polystyrene in gel permeation chromatography (GPC). ~ 8000, most preferably 4000-6000. If the molecular weight of the acid-modified diene polymer is too small, the adhesiveness to the elastomer may be deteriorated, and conversely, if it is too large, the mechanical properties may be deteriorated.

As the acid-modified diene-based polymer (B3), a (anhydrous) maleic-modified diene-based polymer is preferable, (anhydrous) maleic anhydride-based polybutadiene is more preferable, and maleic acid-modified polybutadiene is most preferable.

In the second treatment agent, the concentration of the acid-modified diene polymer (B3) can be selected from the range of about 1 to 15% by mass.

When the first treatment agent is the first treatment agent (A1), the concentration (concentration in terms of solid content) of the acid-modified diene polymer (B3) in the second treatment agent is, for example, 2.5 to 15 mass by mass. %, preferably 3 to 10% by mass, more preferably 3.5 to 10% by mass, more preferably 3.5 to 8% by mass, and most preferably 4 to 5% by mass. If the concentration of the acid-modified diene polymer (B3) is too low, the adhesiveness may decrease, and if it is too high, the film may become too thick, or friction with the roller during the bonding process of the core wire. As a result, the film may peel off and slag may be generated, making it difficult to continue the treatment.

When the first treatment agent is the first treatment agent (A2), the concentration (concentration in terms of solid content) of the acid-modified diene polymer (B3) in the second treatment agent is, for example, 1 to 15% by mass. It is preferably 3 to 14% by mass, more preferably 5 to 13% by mass, more preferably 8 to 12% by mass, and most preferably 9 to 11% by mass. If the concentration of the acid-modified diene polymer (B3) is too low, the adhesiveness may decrease, and if it is too high, the film may become too thick, or friction with the roller during the bonding process of the core wire. As a result, the film may peel off and slag may be generated, making it difficult to continue the treatment.

The mass of the acid-modified diene polymer (B3) can be selected from a range of about 0.05 to 2 times the total mass of the condensate (B1) and the unmodified latex (B2).

When the first treatment agent is the first treatment agent (A1), the mass (mass in terms of solid content) of the acid-modified diene polymer (B3) is the sum of the condensate (B1) and the unmodified latex (B2). For example, 0.05 to 2 times, preferably 0.05 to 1.5 times, more preferably 0.1 to 1 times (for example, 0.2 to 0.9 times) the mass (mass in terms of solid content). ), More preferably 0.15 to 0.5 times, most preferably 0.2 to 0.3 times. If the ratio of the acid-modified diene polymer (B3) is too low, the adhesiveness may decrease, and if it is too high, the film may become too thick, or friction with the roller during the bonding process of the core wire. As a result, the film may peel off and slag may be generated, making it difficult to continue the treatment.

When the first treatment agent is the first treatment agent (A2), the mass (mass in terms of solid content) of the acid-modified diene polymer (B3) is the sum of the condensate (B1) and the unmodified latex (B2). For example, 0.1 to 2 times, preferably 0.3 to 1.8 times, more preferably 0.5 to 1.7 times, and more preferably 1 to 1. times the mass (mass in terms of solid content). It is 6 times, most preferably 1.3 to 1.5 times. If the ratio of the acid-modified diene polymer (B3) is too low, the adhesiveness may decrease, and if it is too high, the film may become too thick, or friction with the roller during the bonding process of the core wire. As a result, the film may peel off and slag may be generated, making it difficult to continue the treatment.

(B4) Hydrophilic solvent In the present invention, the solvent of the second treatment agent may be a hydrophilic solvent (B4), and the load on the environment is smaller than that of an organic solvent (particularly, a hydrophobic solvent). The hydrophilic solvent (B4) can be selected from the hydrophilic solvents exemplified as the hydrophilic solvent (A2-4) of the first treatment agent (A2), including the preferred embodiment.

The solid content (active ingredient) concentration in the second treatment agent is, for example, 1 to 70% by mass, preferably 5 to 60% by mass, more preferably 10 to 50% by mass, and most preferably 15 to 40% by mass. May be good. If the solid content concentration is too low, the adhesiveness may be lowered, and if it is too high, solid content may be formed on the surface of the core wire after the treatment.

(B5) Other Additives The second treatment agent may be a reactive binder resin (epoxy compound or the like) or a conventional additive (crosslinking agent) as another additive (B5) as long as the effect of the present invention is not impaired. , Curing accelerator, co-crosslinking agent, adhesive improver, filler, anti-aging agent, lubricant, tackifier, stabilizer, coupling agent, plasticizer, colorant, etc.) and the like may be contained.

The ratio of the other additive (B5) may be 30% by mass or less with respect to the entire second treatment agent, for example, 0.01 to 30% by mass, preferably 0.05 to 20% by mass, more preferably. Is 0.1 to 10% by mass.

The second treatment agent preferably contains substantially no halogen, and particularly preferably does not contain halogen, from the viewpoint of reducing the environmental load.

(Processing method)
The method for preparing the second treatment agent is not particularly limited, and for example, it may be prepared by stirring and mixing all at once, or by dividing and mixing by stirring.

The method of treating the first treated yarn with the second treated agent is not particularly limited, and examples thereof include spraying, coating, and dipping. Of these treatment methods, immersion is widely used. The immersion time is, for example, 1 to 120 seconds, preferably 5 to 60 seconds, and more preferably 10 to 30 seconds.

After treating the first treated yarn with the second treated agent, it may be dried if necessary. The drying temperature is, for example, 100 to 250 ° C., preferably 150 to 240 ° C., more preferably 170 to 220 ° C. The drying time is, for example, 10 seconds to 10 minutes, preferably 30 seconds to 5 minutes, and more preferably 1 to 3 minutes. Further, the drying may be performed by applying tension to the first treated yarn. The tension may be, for example, about 5 to 15 N, preferably about 10 to 15 N. When the yarn is dried under the action of tension, the treatment agent becomes more familiar with the first treated yarn, twisting unevenness can be reduced, and variations in the diameter of the twisted yarn caused by twisting unevenness can be reduced.

The average thickness of the coating film formed by the second treatment agent is, for example, 0.05 to 30 μm, preferably 0.1 to 10 μm, more preferably 0.3 to 5 μm, more preferably 1 to 4.5 μm, and most preferably. It is 3 to 4 μm. If the thickness of the film formed by the second treatment agent is too thin, the adhesive strength between the core wire and the elastomer may decrease, and if it is too thick, the shear adhesive strength between the core wire and the elastomer may decrease. ..

The production method of the present invention may include the first treatment step and the second treatment step, and preferably does not include the step of overcoating with rubber glue. The manufacturing method of the present invention can improve the adhesiveness between the core wire and the elastomer without including the step of overcoating, which causes an increase in man-hours and an increase in environmental load due to the use of an organic solvent. The environmental load can be reduced.

<Belt for transmission belt>
The transmission belt core wire obtained by the production method of the present invention is a transmission belt core wire to which a resin component is added between the surface and the fiber by the production method, and at least the resin component (A) is provided between the surface and the fiber. And a condensate of resorcin and formaldehyde (B1), an unmodified latex (B2) and an acid-modified diene polymer (B3).

The core wire obtained by the production method of the present invention is suitable for transmission belt applications, and is usually used in contact with the rubber layer of the transmission belt, and is preferably embedded in the rubber layer for use. The rubber layer may be formed of a rubber composition containing an elastomer and can be appropriately selected depending on the intended use of the transmission belt. For example, in a low-edge cogged V-belt, an adhesive rubber formed of the rubber composition is used. It may be a layer.

As the elastomer, vulverable or crosslinkable rubber may be used, for example, diene rubber [natural rubber, isoprene rubber, butadiene rubber, chloroprene rubber, styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (nitrile rubber), hydrogen. Chemicalized nitrile rubber, etc.], ethylene-α-olefin elastomer, chlorosulfonated polyethylene rubber, alkylated chlorosulfonated polyethylene rubber, epichlorohydrin rubber, acrylic rubber, silicone rubber, urethane rubber, fluororubber, and the like. These elastomers can be used alone or in combination of two or more.

Of these, ethylene-propylene copolymer (EPM) and ethylene-propylene-diene ternary copolymer (EPDM) are excellent in ozone resistance, heat resistance, cold resistance, and weather resistance, and can reduce the weight of the belt. Ethylene-α-olefin elastomer such as EPDM is preferable, and EPDM is particularly preferable. In the present invention, even if the elastomer is an ethylene-α-olefin elastomer, the adhesiveness between the rubber layer and the core wire can be improved.

In EPDM, the ratio (mass ratio) of ethylene to propylene is the former / latter = 35/65 to 90/10, preferably 40/60 to 80/20, more preferably 45/55 to 70/30, most preferably. Is 50/50 to 60/40.

The diene content of the ethylene-α-olefin elastomer (particularly, ethylene-α-olefin-diene ternary copolymer rubber such as EPDM) may be 10% by mass or less, preferably 0.1 to 10% by mass, for example. Is 0.5 to 8% by mass, more preferably 1 to 7% by mass, and most preferably 2 to 6% by mass. If the diene content is too high, the heat resistance may decrease.

In the present application, the diene content means the mass ratio of the diene monomer unit in all the units constituting the ethylene-α-olefin elastomer, and can be measured by a conventional method, but may be a monomer ratio.

When the elastomer contains an ethylene-α-olefin elastomer, the proportion of the ethylene-α-olefin elastomer in the elastomer may be 50% by mass or more (particularly about 80 to 100% by mass), and 100% by mass (ethylene-α). − Olefin elastomer only) is particularly preferred.

The rubber composition may contain a conventional vulcanizing agent or cross-linking agent in addition to the elastomer. When the elastomer is an ethylene-α-olefin elastomer, the cross-linking agent may be an organic peroxide.

Examples of the organic peroxide include diacyl peroxide (dilauroyl peroxide, dibenzoyl peroxide, etc.), peroxyketal [1,1-di (t-butylperoxy) cyclohexane, 2,2-di (t). -Butyl peroxy) butane, etc.], alkyl peroxy ester (t-butyl peroxybenzoate, etc.), dialkyl peroxide [di-t-butyl peroxide, dicumyl peroxide, t-butyl cumyl peroxide, 2,5 -Dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexin-3,1,1-di (t-butylperoxy) ) -3,3,5-trimethylcyclohexane, 1,3-bis (2-t-butylperoxyisopropyl) benzene, 2,5-di-methyl-2,5-di (benzoylperoxy) hexane, etc.], Peroxycarbonate (t-butylperoxyisopropyl carbonate, t-butylperoxy-2-ethyl-hexyl carbonate, t-amylperoxy-2-ethyl-hexyl carbonate, etc.) and the like can be mentioned. These organic peroxides can be used alone or in combination of two or more. Of these, dialkyl peroxides such as 1,3-bis (2-t-butylperoxyisopropyl) benzene are preferable.

The ratio of the vulcanizing agent or the cross-linking agent (particularly, the organic peroxide) is, for example, 0.1 to 30 parts by mass, preferably 1 to 20 parts by mass, and more preferably 3 to 15 parts by mass with respect to 100 parts by mass of the elastomer. Parts, most preferably 5 to 10 parts by mass.

The rubber composition may further contain a conventional reinforcing agent. Conventional reinforcing agents include, for example, carbon black, silica, clay, calcium carbonate, talc, mica, short fibers and the like. These reinforcing agents can be used alone or in combination of two or more.

The ratio of the reinforcing agent is, for example, 10 to 200 parts by mass, preferably 20 to 150 parts by mass, more preferably 30 to 100 parts by mass, and most preferably 50 to 80 parts by mass with respect to 100 parts by mass of the elastomer.

The rubber composition of the present invention may further contain a conventional additive used as a rubber compounding agent. Conventional additives include, for example, co-crosslinking agents (such as bismaleimides), vulcanization aids or vulcanization accelerators (such as thiuram-based accelerators), vulcanization retarders, and metal oxides (zinc oxide, magnesium oxide). , Calcium oxide, barium oxide, iron oxide, copper oxide, titanium oxide, aluminum oxide, etc.), softeners (such as paraffin oil and oils such as naphthenic oil), processing agents or processing aids (stearic acid, stearic acid, etc.) Metal salts, waxes, paraffins, fatty acid amides, etc.), silane coupling agents, anti-aging agents (antioxidants, heat anti-aging agents, bending crack inhibitors, ozone deterioration inhibitors, etc.), coloring agents, tackifiers, Examples include stabilizers (ultraviolet absorbers, heat stabilizers, etc.), flame retardants, antistatic agents, and the like. These additives can be used alone or in combination of two or more. The metal oxide may act as a cross-linking agent.

The total ratio of the conventional additives is, for example, 5 to 50 parts by mass, preferably 10 to 30 parts by mass, and more preferably 15 to 25 parts by mass with respect to 100 parts by mass of the elastomer.

The transmission belt core wire may be an aramid core wire obtained by the above-mentioned manufacturing method. That is, the aramid core wire for the transmission belt may be an aramid-based multifilament yarn (for example, a twisted yarn cord) treated (for example, coated or impregnated) with the first treatment agent and the second treatment agent.

The average diameter of the transmission belt core wire is, for example, 0.3 to 3.6 mm, preferably 0.5 to 3.1 mm, and more preferably 0.6 to 2.7 mm.

<Transmission belt and its manufacturing method>
The transmission belt may include the transmission belt core wire, and usually, a rubber layer in which the transmission belt core wire (particularly, a plurality of transmission belt core wires) is embedded along the longitudinal direction (or the circumferential direction) of the belt. In many cases, it is a transmission belt equipped with. The distance between adjacent core wires (spinning pitch) is, for example, 0.5 to 4 mm, preferably 0.6 to 2.5 mm, and more preferably 0.7 to 2.3 mm.

Typically, the transmission belt may be a transmission belt having an adhesive rubber layer and a compression rubber layer on one surface of the adhesive rubber layer, and the adhesive rubber layer embeds a transmission belt core wire. An stretch rubber layer may be provided on the other surface of the adhesive rubber layer. Further, the transmission belt may have a part (for example, the surface of the stretch rubber layer and / or the compressed rubber layer) or the whole of the belt body made of the rubber layer covered (or laminated) with the reinforcing cloth.

Examples of such a transmission belt include a V-belt such as a wrapped V-belt and a low-edge V-belt, a V-ribbed belt, a flat belt, and a toothed belt.

FIG. 1 is a schematic cross-sectional view showing a V-ribbed belt which is an example of a transmission belt including a transmission belt core wire obtained by the manufacturing method of the present invention. In this example, an adhesive rubber layer 2 in which a transmission belt core wire 1 is embedded in the longitudinal direction of the belt, a compressed rubber layer 3 formed on one surface (inner peripheral surface) of the adhesive rubber layer, and the adhesive rubber layer. A stretch rubber layer 4 formed on the other surface (outer peripheral surface or back surface) of the rubber layer 3 is provided, and a rib 5 having a V-shaped groove is formed on the compression rubber layer 3. The compressed rubber layer 3 contains short fibers 6 in order to improve the lateral pressure resistance of the transmission belt. The adhesive rubber layer 2, the compressed rubber layer 3, and the stretched rubber layer 4 are preferably formed of a rubber composition containing an ethylene-α-olefin elastomer or the like. Further, a reinforcing cloth made of a woven fabric, a non-woven fabric, a knitted fabric, or the like may be laminated on the back surface of the stretch rubber layer 4.

FIG. 2 is a schematic cross-sectional view showing a low-edge V-belt which is another example of a transmission belt including a transmission belt core wire obtained by the manufacturing method of the present invention. The belt shown in FIG. 2 is a V-ribbed belt shown in FIG. 1 except that the rib 5 is not formed on the compressed rubber layer 3 and the belt width decreases from the outer peripheral surface to the inner peripheral surface. It is configured in the same way as. A plurality of cogs (convex portions) may be formed on the compressed rubber layer 3 along the longitudinal direction of the belt at predetermined intervals. Further, a reinforcing cloth made of a woven fabric, a non-woven fabric, a knitted fabric or the like may be laminated on the surface (inner peripheral surface) of the compressed rubber layer 3 and the surface (outer peripheral surface) of the stretched rubber layer 4.

In these transmission belts, for example, a sheet for a compression rubber layer and a sheet for a first adhesive rubber layer are sequentially wound around a cylindrical molded drum, and a transmission belt core wire is spirally spun on the sheet, and further, a first 2 A sheet for an adhesive rubber layer and a sheet for an stretch rubber layer are sequentially wound to form a laminated body, and the laminated body is vulcanized to produce a vulcanized belt sleeve, and the cylindrical vulcanized belt sleeve is placed in the circumferential direction. It is formed by cutting into rubber. At the time of this cutting, the transmission belt core wires arranged or oriented in the circumferential direction are also cut, and the transmission belt core wires are exposed on the side surface (cut surface) of the transmission belt. If the transmission belt core wire is exposed on the side surface of the transmission belt, the thread of the core wire is easily unraveled, and the transmission belt core wire protrudes from the side surface of the transmission belt starting from the thread unraveled from the side surface of the transmission belt. Out may occur and the pop-out transmission belt core wire may wind around the rotating pulley shaft and the transmission belt may break. However, in the transmission belts shown in FIGS. 1 and 2, the transmission belt core wire treated with a specific treatment agent is embedded in the adhesive rubber layer, and the filaments of the transmission belt core wire have high cohesiveness with each other. Since the transmission belt core wire does not come loose on the side surface of the belt, pop-out of the transmission belt core wire can be effectively prevented, and the durability of the transmission belt can be significantly improved.

The transmission belt is not limited to the V-ribbed belt and the low-edge V-belt, and can also be used for toothed belts, flat belts, and the like.

The method for manufacturing the transmission belt is not limited to the above method, and is a conventional method including an embedding step of embedding a core wire in a rubber layer along the longitudinal direction of the belt, for example, a pair of unfinished belts, depending on the type of belt. A transmission belt precursor (vulcanization) is obtained by vulcanizing a cylindrical laminate in which an aramid core wire treated with a specific treatment agent is sandwiched between vulcanized rubber sheets (including unvulcanized laminated rubber sheets). A method of producing a belt sleeve) and cutting the cylindrical transmission belt precursor in the circumferential direction can be mentioned. In the present invention, even if the cutting is performed in this way, fluffing or fraying of the aramid core wire is not generated on the side surface of the transmission belt. The pair of unvulcanized rubber sheets may be the same or different, and are often formed of a rubber composition containing an ethylene-α-olefin elastomer.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

Examples 1-9, Reference Examples 1-4 and Comparative Examples 1-5
(Making a twisted cord)
Two raw yarns (Teijin Co., Ltd. "Twaron 1014", 1680 dtex, 1000 filaments) are aligned and twisted down in the S direction at 15 times / 10 cm to make a bottom twisted yarn, and three bottom twisted yarns are used. A multi-twisted yarn in which the twisting directions of the lower twist and the upper twist are opposite to each other is produced by pulling and twisting upward in the Z direction at a number of twists of 20 times / 10 cm.

(Preparation of first treatment agent A1)
The modified epoxy resin, curing agent and toluene were mixed at the ratios shown in Table 1 and stirred at room temperature for 10 minutes to prepare the first treatment agent A1.

Details of the modified epoxy resin and curing agent in Table 1 are as follows.

Modified Epoxy Resin: NBR Modified Epoxy Resin, "EPR-2000" manufactured by ADEKA CORPORATION
Hardener: 2,4,6, -tris (dimethylaminomethyl) phenol, "Daitoclar HD-Acc43" manufactured by Daito Sangyo Co., Ltd.

(Preparation of first treatment agent A2)
Solution C was mixed with the mixture of solutions A and B at the ratios shown in Table 2 and stirred at room temperature for 10 minutes to prepare the first treatment agent A2.

Details of Latex 1 and Carbodiimide in Table 2 are as follows.

Latex 1: Carboxylation-modified NBR latex, "Nipol 1571CL" manufactured by Nippon Zeon Corporation, 38% by mass of active ingredient
Carbodiimide: Polycarbodiimide dispersion, "Carbodilite E-05" manufactured by Nisshinbo Chemical Co., Ltd., active ingredient 40% by mass, NCN equivalent 310.

(Preparation of second treatment agent)
Solution D and solution E are mixed at the ratios shown in Table 3 and stirred at room temperature for 10 minutes to prepare an RFL solution. The obtained RFL solution contains a maleic acid-modified polybutadiene dispersion and water shown in Tables 6 to 8. The second treatment was prepared by adding in proportion and stirring at room temperature for 10 minutes.

Details of the latex 2 in Table 3 and the maleic acid-modified polybutadiene dispersion in Tables 6 to 8 are as follows.

Latex 2: Styrene-butadiene-vinylpyridine latex, "Nipol 2518FS" manufactured by Zeon Corporation, active ingredient 40.5% by mass
Maleic acid-modified polybutadiene dispersion: "Ricobond 7004" manufactured by Clay Valley, solid content concentration 30% by mass.

(Dip treatment of twisted cord)
For Examples 1 to 5, Reference Examples 1 and 2, and Comparative Examples 1 and 2, the obtained twisted cords were sequentially subjected to two bath treatments of the first treatment agent A1 and the second treatment agent as shown below. , Got the processing code.

That is, the untreated twisted cord was immersed in the first treatment agent A1 for 30 seconds and dried under the conditions of 190 ° C. for 1 minute to obtain a first treatment yarn (first treatment step). Next, the first treated yarn was immersed in the second treatment agent for 15 seconds and dried at 200 ° C. for 2 minutes to obtain a second treated yarn (second treatment step).

On the other hand, with respect to Examples 6 to 9, Reference Examples 3 to 4 and Comparative Examples 3 to 4, in the first treatment step, the first treatment agent A2 was used instead of the first treatment agent A1 and then immersed for 30 seconds. The second treated yarn was obtained in the same manner as in Examples 1 to 5, Reference Examples 1 and 2 and Comparative Examples 1 and 2, except that the first treated yarn was obtained by drying at 150 ° C. for 1 minute.

In Comparative Example 5, the untreated twisted cord was immersed in the second treatment agent for 15 seconds without going through the first treatment step, and dried at 200 ° C. for 2 minutes to obtain the second treated yarn. Obtained.

(Preparation of sheet for adhesive rubber layer)
The adhesive rubber layer sheet was prepared by kneading the compositions having the formulations shown in Table 4 with a Banbury mixer and rolling them to a predetermined thickness with a calender roll.

The details of the components in Table 4 are as follows.

EPDM1: "EP24" manufactured by JSR Corporation, ethylene content 54% by mass, diene content 4.5% by mass
Carbon Black FEF: "N550" manufactured by Cabot Japan Co., Ltd.
Silica: "Ultrasil VN3" manufactured by Evonik Degussa Japan, BET specific surface area 175m ² / g
Paraffin oil: "Diana Process Oil PW-90" manufactured by Idemitsu Kosan Co., Ltd.
Anti-aging agent: 4,4'-bis (α, α-dimethylbenzyl) diphenylamine, "Nocrack CD" manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.
Zinc oxide: "Zinc oxide 2 types" manufactured by Sakai Chemical Industry Co., Ltd.
Organic peroxide: α, α'-bis (t-butylperoxy) diisopropylbenzene, "P-40MB (K)" manufactured by NOF CORPORATION, 40% by mass of active ingredient.

(Preparation of compressed rubber layer and stretch rubber layer sheet)
The compressed rubber layer and the stretched rubber layer sheet were prepared by kneading the compositions having the formulations shown in Table 5 with a Banbury mixer and rolling them to a predetermined thickness with a calender roll.

The details of the components in Table 5 are as follows.

EPDM2: "EP93" manufactured by JSR Corporation, ethylene content 55% by mass, diene content 2.7% by mass
Polyamide short fiber: "Twaron" manufactured by Teijin Limited, average fiber length 3 mm
Carbon Black HAF: "N330" manufactured by Cabot Japan Co., Ltd.
Paraffin oil: "Diana Process Oil PW-90" manufactured by Idemitsu Kosan Co., Ltd.
Anti-aging agent: 4,4'-bis (α, α-dimethylbenzyl) diphenylamine, "Nocrack CD" manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.
Zinc oxide: "Zinc oxide 2 types" manufactured by Sakai Chemical Industry Co., Ltd.
Stearic acid: "Beads stearic acid camellia" manufactured by NOF CORPORATION
Co-crosslinking agent: N, N'-m-phenylenedimaleimide, "Barnock PM" manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.
Organic peroxide: α, α'-bis (t-butylperoxy) diisopropylbenzene, "P-40MB (K)" manufactured by NOF CORPORATION, 40% by mass of active ingredient.

(Making a transmission belt)
A laminated body of a reinforcing cloth (thickness 0.5 mm, composition 2/2 twill weave polyamide canvas) and a sheet for a compressed rubber layer (unvulcanized rubber) is alternately placed with the reinforcing cloth facing down. A cog pad (not completely vulcanized and in a semi-vulcanized state) in which the cog portion was molded was produced by placing it in a flat cogged mold arranged and pressing and pressing at 75 ° C. Next, both ends of the cog pad were cut vertically from the top of the cog ridge.

A cylindrical mold is covered with an inner mother mold in which teeth and grooves are arranged alternately, and the cog pad is wound by engaging the teeth and the groove and jointed at the top of the cog ridge. After laminating the adhesive rubber layer sheet (unvulcanized rubber) on top, the core wire is spun in a spiral shape, and the adhesive rubber layer sheet (same as the above adhesive rubber layer sheet) and the stretch rubber layer are on top of this. Sheets (unvulcanized rubber) were sequentially wound to prepare a molded product. Then, the mold was placed in a vulcanizing can by covering with an outer mother mold and a jacket in which tooth portions and grooves were alternately arranged, and vulcanized at a temperature of 170 ° C. for 40 minutes to obtain a belt sleeve. This sleeve is cut into a V shape with a cutter, and a low-edge double-cogged V-belt (size: upper width 35.0 mm, thickness (inner circumference side cog ridge)) is a speed change belt with cogs on the inner and outer circumferences of the belt. (Distance from to outer circumference side cog peak) 15.0 mm, V angle 28 °, cog height (inner circumference side) 6.0 mm, cog height (outer circumference side) 2.8 mm, belt outer circumference length 1100 mm) did.

(Peeling test)
The processing cord was spirally wound around the outer circumference of a cylinder having an outer diameter of 150 mm until the width became 30 mm. After sticking the adhesive tape on the wound processing cord, it was cut to a length of 150 mm. The laminated body of the adhesive tape and the processing cord was inserted into a mold having a width of 30 mm, a length of 150 mm, and a depth of 4 mm so that the surface of the adhesive tape was facing down (contacting the bottom surface of the mold). Then, an unvulcanized rubber sheet for the compressed rubber layer was filled on the processing cord so that the length direction of the short fibers and the length direction of the processing cord were parallel to each other. A reinforcing cloth was placed on it, and vulcanized at a surface pressure of 2 MPa and a temperature of 170 ° C. for 40 minutes. The vulcanized laminate was cut to a width of 25 mm, and as shown in FIG. 3, a sample for a peeling test having a width of 25 mm, a length of 150 mm, and a thickness of 4 mm was prepared.

As shown in FIG. 4, at one end of the prepared peeling test sample in the length direction, a notch is made at the interface between the processing cord 12 and the vulcanized rubber 13 with a cutting tool, and the adhesive tape 11 and the processing cord 12 are formed. Was separated into a grip portion A in which the vulcanized rubber 13 and the reinforcing cloth 14 were laminated, and a grip portion B (the length of the grip portion was about 30 mm) in which the vulcanized rubber 13 and the reinforcing cloth 14 were laminated.

The upper gripper of the tensile tester (“AGS-J10kN” manufactured by Shimadzu Corporation)) grips the grip part A and the lower gripper grips the grip part B, and raises the upper gripper at a speed of 50 mm / min. , The tensile force was recorded. The measurement time was set to 2 minutes so that the moving distance of the upper gripper and the peeled portion were about 100 mm. The test temperature (atmospheric temperature) was measured at two levels of 23 ° C. and 120 ° C., and the peeling test sample was measured after being left at the test temperature for 3 hours or more. The tensile force shows a wavy curve, and the average value was calculated according to the E method of JIS K6274 (2018). That is, the average value of the maximum value and the minimum value among all the peaks of the wavy curve was obtained by ignoring the initial rising curve at the start of the test. The obtained average value was divided by the width of the sample to obtain the peeling force per 1 cm of width.

(An endurance test)
As shown in FIG. 5, the durability test was performed on the drive pulley 21 (outer diameter 110 mm, V-groove width 35 mm, V-groove angle 26 °) and the driven pulley 22 (outer diameter 240 mm, V-groove width 35 mm, V-groove angle 26 °). ) And a two-axis running tester. A low-edge double cogged V-belt 23 was hung on each pulley, the rotation speed of the drive pulley was 6000 rpm, the load of the driven pulley was 25 kW, the axial load (dead weight) was 2000 N, and the vehicle was run at an ambient temperature of 80 ° C. for 70 hours. .. After the durability test, the side surface of the compressed rubber (the surface in contact with the pulley) was visually observed to confirm the presence or absence of peeling between the core wire and the elastomer, and if peeling was observed, the length of peeling was measured. The peeling length means the length extending in the peripheral length direction of the belt. When peeling was confirmed at multiple points, the maximum length was taken as the peeling length.

The evaluation results of Examples, Reference Examples and Comparative Examples are shown in Tables 6-8. In Tables 6 to 8, the blending amount, solid content and concentration are all based on mass.

Table 6 shows the results of applying the first treatment agent A1 as the first treatment step, Table 7 shows the results of applying the first treatment agent A2 as the first treatment step, and Table 8 shows the untreated twisted cord. Is the result of being subjected to the second treatment step without going through the first treatment step.

In Table 6, when the RFL concentration in the second treatment agent is 8.0 to 18.2% by mass and the concentration of maleic acid-modified polybutadiene is 2.7 to 13.2% by mass, the peeling force is high and the durability is high. There was no or small peeling after the test, and good results were shown. Among them, Examples 2 and 3 having an RFL concentration of 11.6 to 17.0% by mass and a maleic acid-modified polybutadiene concentration of 4.2 to 9.6% by mass showed high peeling power. Reference Example 1 is an example in which the concentration of maleic acid-modified polybutadiene is low, and Reference Example 2 is an example in which the concentration of maleic acid-modified polybutadiene and RFL is low, but the peeling power was low in both cases. Further, in Comparative Example 1 containing no RFL, the coating was peeled off during the treatment and slag was generated, so that the treatment could not be continued. Comparative Example 2 containing no maleic acid-modified polybutadiene had a low peeling force and a long peeling length after the durability test.

In Table 7, when the RFL concentration in the second treatment agent is 5.2 to 15% by mass and the concentration of maleic acid-modified polybutadiene is 1.2 to 9.7% by mass, the peeling power is high and after the durability test. There was no or small peeling, and good results were shown. Among them, Examples 7 and 8 having an RFL concentration of 6.7 to 10.0% by mass and a maleic acid-modified polybutadiene concentration of 6.2 to 9.7% by mass showed high peeling power. Reference Example 3 is an example in which the concentration of maleic acid-modified polybutadiene is low, and Reference Example 4 is an example in which the concentration of RFL is low, but the peeling force was low in both cases. Further, Comparative Example 3 is an example in which the second treatment liquid does not contain RFL, but the peeling force is further reduced. Further, Comparative Example 4 is an example in which the second treatment liquid does not contain acid-modified polybutadiene, but the result was the same as that of Comparative Example 3.

Since the second treatment agent is a mixture of RFL and maleic acid-modified polybutadiene, paying attention to these ratios, when the first treatment agent A1 is used, the ratio of maleic acid-modified polybutadiene / RFL (mass of solid content). Good results were obtained when the ratio) was between 0.17 and 1.66, and when the first treatment agent A2 was used, good results were obtained when the ratio was between 0.08 and 1.45. ..

Table 8 shows the results of Comparative Example 5 which was subjected to the second treatment step without going through the first treatment step, but the peeling force was not improved as in the results of Comparative Examples 3 and 4.

Since the transmission belt core wire obtained by the manufacturing method of the present invention has excellent durability, the transmission belt (for example, a friction transmission belt such as a V-belt or a V-ribbed belt, a toothed belt, a meshing transmission belt such as a double-sided toothed belt) Etc.) suitable for applications. Further, the transmission belt core wire obtained by the manufacturing method of the present invention is also suitable for a low-edge V-belt because it has excellent adhesiveness to rubber, and is used for a transmission whose gear ratio changes steplessly during running. It is particularly suitable for belts to be used (for example, low edge cogged V belts such as low edge double cogged V belts).

1 ... Transmission belt core wire 2 ... Adhesive rubber layer 3 ... Compressed rubber layer 4 ... Stretch rubber layer 5 ... Rib 6 ... Short fiber

Claims (13)

The first treatment step of treating the untreated yarn of the transmission belt core wire with the first treatment agent containing the resin component (A) to obtain the first treated yarn, the condensate of resorcin and formaldehyde (B1), the unmodified latex ( A method for producing a transmission belt core wire, which comprises a second treatment step of treating the first treated yarn with a second treated agent containing B2) and an acid-modified diene polymer (B3) to obtain a second treated yarn. The second treatment agent contains a modified epoxy resin (A1-1) in which the resin component (A) is modified with an elastic polymer, and the total ratio (solid content conversion) of the condensate (B1) and the unmodified latex (B2) is contained in the second treatment agent. The production method according to claim 1, wherein the content is 8 to 25% by mass, and the proportion (in terms of solid content) of the acid-modified diene polymer (B3) is 2.5 to 15% by mass in the second treatment agent. The resin component (A) contains a condensate of resorcin and formaldehyde (A2-1), a latex (A2-2), and a curing agent (A2-3) containing a polycarbodiimide resin having a plurality of carbodiimide groups, and the condensate. The total ratio (solid content conversion) of (B1) and the unmodified latex (B2) is 5 to 25% by mass in the second treatment agent, and the ratio (solid content conversion) of the acid-modified diene polymer (B3) is the second. 2. The production method according to claim 1, wherein the content is 1 to 15% by mass in the treatment agent. The production method according to any one of claims 1 to 3, wherein the acid-modified diene polymer (B3) is a carboxylic acid-modified polybutadiene. Claim that the mass (solid content equivalent) of the acid-modified diene polymer (B3) is 0.05 to 2 times the total mass (solid content equivalent) of the condensate (B1) and the unmodified latex (B2). Item 8. The production method according to any one of Items 1 to 4. The production method according to any one of claims 1 to 5, wherein the first treatment agent and the second treatment agent do not contain halogen. The production method according to any one of claims 1 to 6, which does not include a step of overcoating with rubber glue. A treatment agent for treating untreated yarn of a transmission belt core wire, which contains a condensate of resorcin and formaldehyde (B1), an unmodified latex (B2), and an acid-modified diene polymer (B3). .. The treatment agent according to claim 8, wherein the transmission belt core wire is a core wire in contact with a rubber layer containing an ethylene-α-olefin elastomer. A treatment kit for treating untreated yarn of the transmission belt core wire, which is a first treatment agent containing a resin component (A), a condensate of resorcin and formaldehyde (B1), and an unmodified latex (B2). And a treatment kit containing a second treatment agent containing an acid-modified diene polymer (B3). A method for manufacturing a transmission belt, which comprises an embedding step of embedding a core wire obtained by the manufacturing method according to any one of claims 1 to 7 in a rubber layer along the longitudinal direction of the belt. The production method according to claim 11, wherein the rubber layer contains an ethylene-α-olefin elastomer. The manufacturing method according to claim 11 or 12, wherein the transmission belt is a low-edge V-belt.

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