Crosslinking agent composition, rubber reinforcing fiber treatment agent, rubber reinforcing fiber treatment agent kit, and method for manufacturing rubber reinforcing fiber.

Abstract

The present invention aims to provide a crosslinking agent composition for a resorcinol- and formaldehyde-free rubber reinforcing fiber treatment agent, a rubber reinforcing fiber treatment agent and a rubber reinforcing fiber treatment agent kit, as well as rubber reinforcing fibers and rubber articles with excellent adhesion to rubber compositions. The present invention relates to a crosslinking agent composition for a resorcinol- and formaldehyde-free rubber reinforcing fiber treatment agent, comprising a capped isocyanate compound having a structure containing carbon-carbon double bonds in its molecule.

Description

Crosslinking Agent Composition, Fiber Treatment Agent for Reinforcing Rubber, Fiber Treatment Agent Kit for Reinforcing Rubber, and Method for Manufacturing Reinforcing Fiber for Rubber The present invention relates to a crosslinking agent composition for a fiber treatment agent for reinforcing rubber that does not contain resorcinol and formaldehyde, a fiber treatment agent for reinforcing rubber that does not contain resorcinol and formaldehyde, a fiber treatment agent kit for reinforcing rubber that does not contain resorcinol and formaldehyde, a method for manufacturing reinforcing fiber for rubber using the same, reinforcing fiber for rubber obtained thereby, and a rubber product. In the past, in high-strength rubber products such as tires and power transmission belts, it has been known that by using reinforcing fibers for rubber having an adhesive composition containing resorcinol, or a resorcinol-formaldehyde initial condensate obtained by condensing resorcinol and formaldehyde, and formaldehyde and rubber latex attached to the surface of fibers formed of polyester fibers or the like, a high-strength rubber product having excellent adhesion between the reinforcing fiber for rubber and the rubber composition can be obtained. However, although formaldehyde is an effective raw material for crosslinking with resorcinol, there are concerns about its harmfulness to the human body, so a reduction in its usage amount is required. Even for adhesive compositions for reinforcing fibers for rubber, various attempts have been made not to use resorcinol and formaldehyde (Patent Documents 1 to 10). [Prior Art Documents] [Patent Documents] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-274494 [Patent Document 2] International Publication No. 2010 / 125992 [Patent Document 3] Japanese Patent Application Laid-Open No. 2012-224962 [Patent Document 4] Japanese Patent Application Laid-Open No. 2013-64037 [Patent Document 5] International Publication No. 2014 / 091376 [Patent Document 6] International Publication No. 2014 / 175844 [Patent Document 7] International Publication No. 2015 / 188939 [Patent Document 8] International Publication No. 2019 / 015792 [Patent Document 9] International Publication No. 2018 / 003572 [Patent Document 10] International Publication No. 2020 / 129939 [Problems to be Solved by the Invention] As an attempt to avoid using resorcinol and formaldehyde, including not using resorcinol-formaldehyde initial condensates, Patent Document 1 discloses an adhesive solution for reinforcing rubber products that adheres to cellulose used in contact with a rubber layer and contains tris(2-mercaptoethyl)amine and a diene rubber. Patent Documents 2 and 3 disclose an adhesive composition for organic cellulose containing a blocked isocyanate compound, an epoxy compound, and a rubber latex. Patent Document 4 discloses an adhesive composition for organic cellulose containing a urethane resin having a thermally dissociable blocked isocyanate group, an epoxy compound, a polymer having an oxazoline group, polyethyleneimine, and a rubber latex. Patent Documents 5 to 8 disclose an impregnation composition containing an acrylic polymer, an epoxy compound, a blocked isocyanate compound, and a rubber latex. Patent Document 9 discloses an adhesive for organic fibers containing at least one component selected from the group consisting of polyphenols, chlorophenol resins, and lignin resins, and other polymer components. Patent Document 10 discloses an easy-adhesion treatment liquid containing a thermoplastic elastomer, a blocked isocyanate compound, and a rubber latex. However, in these attempts to avoid using resorcinol and formaldehyde, it has not been possible to obtain a high-strength rubber product with excellent adhesion between the rubber-reinforcing fiber and the rubber composition, which is equivalent to the case of using a rubber-reinforcing fiber with an adhesive composition containing resorcinol, or a resorcinol-formaldehyde initial condensate condensed from resorcinol and formaldehyde, and formaldehyde and a rubber latex. Here, an object of the present invention is to provide a crosslinking agent composition for a rubber-reinforcing fiber treatment agent without resorcinol and formaldehyde, a rubber-reinforcing fiber treatment agent without resorcinol and formaldehyde, and a rubber-reinforcing fiber treatment agent set, as well as a rubber-reinforcing fiber and a rubber product having excellent adhesion to a rubber composition. [Means for Solving the Problem] The above problem is basically solved by a crosslinking agent composition for a rubber-reinforcing fiber treatment agent without resorcinol and formaldehyde, which is a crosslinking agent composition containing a blocked isocyanate compound having a structure containing a carbon-carbon double bond in the molecule. Here, the structure containing a carbon-carbon double bond is preferably a structure selected from a polybutadiene structure and a polyisoprene structure. Furthermore, the above problem is basically solved by a rubber-reinforcing fiber treatment agent without resorcinol and formaldehyde, which is a rubber-reinforcing fiber treatment agent containing a rubber latex and the above crosslinking agent composition. Among the above-mentioned fiber treating agents for rubber reinforcement, it is preferred to further contain an epoxy compound and / or a blocked isocyanate compound having no carbon-carbon double bond-containing structure in the molecule. Also, the content of the blocked isocyanate compound having a carbon-carbon double bond-containing structure in the above molecule is preferably 0.5 to 25 parts by mass relative to 100 parts by mass of the content of the above rubber latex. Also, for the fiber treating agent for rubber reinforcement (solid component concentration Z 1 mass %), the amount of epoxy groups and the amount of blocked isocyanate groups are preferably such that the following formula (1) is satisfied: -30 ≦ (X 1 -Y 1 ) × 20 / Z 1 ≦ 10 (1) [In the formula, X 1 : the amount of epoxy groups (mmol) contained in the treating agent (1 kg) Y 1 : the amount of blocked isocyanate groups (mmol) contained in the treating agent (1 kg)]. Also, the above problem is basically solved by a kit of fiber treating agents for rubber reinforcement that does not contain resorcinol and formaldehyde, which includes: treating agent 1 containing an epoxy compound and a blocked isocyanate compound having no carbon-carbon double bond-containing structure in the molecule, and treating agent 2 containing rubber latex and the above crosslinking agent composition. Also, it is basically solved by a method for manufacturing fiber for rubber reinforcement, which has the steps of: using the kit of fiber treating agents for rubber reinforcement, performing a treatment of attaching a processing liquid containing the treating agent 1 to the fiber, and then performing a treatment of attaching a processing liquid containing the treating agent 2. Here, in the treating agent 2, the content of the blocked isocyanate compound having a carbon-carbon double bond-containing structure in the above molecule is preferably 0.5 to 20 parts by mass relative to 100 parts by mass of the content of the above rubber latex. Also, the amount of epoxy groups and the amount of blocked isocyanate groups contained in the above treating agent 1 (solid component concentration Z 2 mass %) and the above treating agent 2 (solid component concentration Z 3 mass %) are preferably such that the following formula (2) is satisfied: 20 ≦ [X 2 × 2 / Z 2 -(Y 2 × 2 / Z 2 +Y 3 ×20 / Z 3 )]≦70 (2) [wherein, X 2 : the amount (mmol) of epoxy groups contained in the above-mentioned treating agent 1 (1 kg) Y 2 : the amount (mmol) of blocked isocyanate groups contained in the above-mentioned treating agent 1 (1 kg) Y 3 : the amount (mmol) of blocked isocyanate groups contained in the above-mentioned treating agent 2 (1 kg)]. Furthermore, the above problem is basically solved by a set of fiber treating agents for rubber reinforcement that does not contain resorcinol and formaldehyde, which includes: a treating agent 3 containing an epoxy compound and the above cross-linking agent composition, and a treating agent 4 containing a rubber latex and a blocked isocyanate compound that does not have a structure containing a carbon-carbon double bond in the molecule. The above problem is also basically solved by a method for manufacturing rubber-reinforcing fibers, which has the steps of: using the set of fiber treating agents for rubber reinforcement, performing a treatment to attach a processing liquid containing the treating agent 3 to the fibers, and then performing a treatment to attach a processing liquid containing the treating agent 4. Furthermore, the above problem is basically solved by rubber-reinforcing fibers having an adhesive composition obtained by heat-treating a composition and attached to the fiber surface, the composition containing a rubber latex and the above cross-linking agent composition. Also, it is preferable that the composition containing a rubber latex and a cross-linking agent composition further contains an epoxy compound and / or a blocked isocyanate compound that does not have a structure containing a carbon-carbon double bond in the molecule. It is preferable that the above fibers include any one of polyester, nylon, and aramid. Also, the above problem is basically solved by a rubber product containing the above rubber-reinforcing fibers. [Advantages of the Invention] According to the present invention, a cross-linking agent composition for a fiber treating agent for rubber reinforcement that does not contain resorcinol and formaldehyde, a fiber treating agent for rubber reinforcement that does not contain resorcinol and formaldehyde and a set of fiber treating agents for rubber reinforcement, and rubber-reinforcing fibers and rubber products having excellent adhesiveness to a rubber composition can be provided. The cross-linking agent composition of the present invention is a cross-linking agent composition for a fiber treating agent for rubber reinforcement that does not contain resorcinol and formaldehyde, and it includes a blocked isocyanate compound having a structure containing a carbon-carbon double bond in the molecule. It is preferable that the above structure containing a carbon-carbon double bond is a structure selected from a polybutadiene structure and a polyisoprene structure. A blocked isocyanate compound having a structure containing a carbon-carbon double bond in the molecule. A blocked isocyanate compound having a structure containing a carbon-carbon double bond in the molecule is a compound having a structure containing a carbon-carbon double bond and a blocked isocyanate group in the molecule (excluding the epoxy compound used in the present invention). For example, it can be obtained by an addition reaction of a blocked agent to the isocyanate group of a polyisocyanate compound having a structure containing a carbon-carbon double bond in the molecule. Specifically, for example, it can be synthesized by reacting the following raw material components (a) to (c) and, if necessary, (d). (a) Polyisocyanate compound (b) Polyol compound having a structure containing a carbon-carbon double bond in the molecule (c) Blocking agent (d) Compound containing an active hydrogen group (however, excluding the above components (a) to (c)) Hereinafter, each raw material component will be described in more detail. (a) Polyisocyanate compound (hereinafter referred to as "polyisocyanate compound (a)") The polyisocyanate compound (a) is not particularly limited. For example, aromatic polyisocyanates, araliphatic polyisocyanates, aliphatic polyisocyanates, alicyclic polyisocyanates, polyisocyanate derivatives containing derivatives of such polyisocyanates, etc. can be mentioned. Examples of aromatic polyisocyanates include tolylene diisocyanate (2,4-, 2,6-tolylene diisocyanate or a mixture thereof) (TDI), phenylene diisocyanate (m-, p-phenylene diisocyanate or a mixture thereof), 4,4'-biphenyl diisocyanate, 1,5-naphthylene diisocyanate (NDI), diphenylmethane diisocyanate (4,4'-, 2,4'-, 2,2'-diphenylmethane diisocyanate or a mixture of two or more thereof) (MDI), o-toluidine diisocyanate (TODI), 4,4'-diphenyl ether diisocyanate, etc. Examples of araliphatic polyisocyanates include xylylene diisocyanate (1,3-, 1,4-xylylene diisocyanate or a mixture thereof) (XDI), tetramethylxylylene diisocyanate (1,3-, 1,4-tetramethylxylylene diisocyanate or a mixture thereof) (TMXDI), ω,ω'-diisocyanate-1,4-diethylbenzene, etc. As the aliphatic polyisocyanate, examples thereof include trimethylene diisocyanate, 1,2-propylene diisocyanate, butylene diisocyanate (tetramethylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate or 1,3-butylene diisocyanate), 1,5-pentamethylene diisocyanate (PDI), 1,6-hexamethylene diisocyanate, 2,6-diisocyanate methyl caproate, etc. As the alicyclic polyisocyanate, examples thereof include 1,3-cyclopentane diisocyanate, 1,3-cyclopentene diisocyanate, cyclohexane diisocyanate (1,4-cyclohexane diisocyanate or 1,3-cyclohexane diisocyanate), 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate) (IPDI), methylene bis(cyclohexyl isocyanate) (4,4’-, 2,4’-, 2,2’-methylene bis(cyclohexyl isocyanate), its trans,trans-isomer, trans,cis-isomer, cis,cis-isomer, a mixture of two or more thereof) (H12MDI), methylcyclohexane diisocyanate (methyl-2,4-cyclohexane diisocyanate or methyl-2,6-cyclohexane diisocyanate), norbornane diisocyanate (various isomers or a mixture of two or more thereof) (NBDI), bis(isocyanatomethyl)cyclohexane (1,3-, 1,4-bis(isocyanatomethyl)cyclohexane or a mixture thereof) (H6XDI), etc. As polyisocyanate derivatives, examples include polymers (e.g., dimers, trimers (e.g., isocyanurate-modified products, iminooxadiazinedione-modified products), pentamers, heptamers, etc.) of the above polyisocyanates (monomers), urethane-modified products (e.g., urethane-modified products formed by further adding the isocyanate groups of the polyisocyanates (monomers) to the urethane groups formed by reacting the above polyisocyanates (monomers) with low molecular weight polyols described below), adducts (e.g., adducts (alcohol adducts) formed by reacting the above polyisocyanates (monomers) with low molecular weight polyols described below), biurea-modified products (e.g., biurea-modified products formed by reacting the above polyisocyanates (monomers) with water or amines), urea-modified products (e.g., urea-modified products formed by further adding the isocyanate groups of the polyisocyanates (monomers) to the urea groups formed by reacting the above polyisocyanates (monomers) with diamines), oxadiazinetrione-modified products (e.g., oxadiazinetriones formed by reacting the above polyisocyanates (monomers) with carbon dioxide gas), carbodiimide-modified products (carbodiimide-modified products formed by the decarboxylative condensation reaction of the above polyisocyanates (monomers)), uretdione-modified products, uretonimine-modified products, etc. Furthermore, polymethylene polyphenyl polyisocyanates (crude MDI, polymeric MDI) etc. may also be mentioned. The polyisocyanate compound (a) may be used alone or in combination of two or more. When two or more polyisocyanate compounds (a) are used in combination, for example, in the production of blocked isocyanates, two or more polyisocyanate compounds can be reacted simultaneously, or the blocked isocyanates obtained by using each polyisocyanate compound individually can also be mixed. In order to obtain a rubber reinforcing fiber treatment agent with excellent adhesion between the rubber reinforcing fiber and the rubber composition, as the polyisocyanate compound (a), aliphatic polyisocyanates and their derivatives, alicyclic polyisocyanates and their derivatives, and aromatic polyisocyanates and their derivatives are preferred. (b) Polyol compound having a structure containing a carbon-carbon double bond in the molecule (hereinafter referred to as "polyol compound (b)") As the polyol compound (b), a compound having a structure containing a carbon-carbon double bond in the molecule and having 1 to 10 hydroxyl groups per molecule can be cited. In this specification, even when there is 1 hydroxyl group per molecule, it is also referred to as a polyol. As such a compound, an unsaturated aliphatic hydrocarbon having a hydroxyl group, and polyol polyolefins having an unsaturated skeleton are preferred. As the unsaturated skeleton, polybutadiene, polyisoprene, isoprene-butadiene copolymer, or polyfarnesene having a long-chain alkyl group in the side chain can be cited. Further, these may include any of structural isomers such as 1,2-repeat units or 1,4-repeat units, and stereoisomers such as cis-forms and trans-forms. Among these, polybutadiene having a hydroxyl group and polyisoprene having a hydroxyl group are preferred. Furthermore, the structure of the aromatic compound does not correspond to the structure containing a carbon-carbon double bond in the present invention. As the polybutadiene having a hydroxyl group, hydroxyl-terminated polybutadiene mainly having 1,4-repeat units (as commercial products, for example, Poly bd R-15HT, Poly bd R-45HT (manufactured by Idemitsu Kosan Co., Ltd.)), and hydroxyl-terminated polybutadiene mainly having 1,2-repeat units (as commercial products, for example, NISSO-PB (registered trademark) G-1000, G-2000, G-3000 (manufactured by Nippon Soda Co., Ltd.)) can be cited. Here, the so-called "1,4-repeat unit" refers to the repeat unit represented by the following formula (1t) or (1c), and the so-called "1,2-repeat unit" refers to the repeat unit represented by the following formula (2). [Chemical formula 1] As the polyisoprene having a hydroxyl group, hydroxyl-terminated polyisoprene (as a commercial product, for example, Poly ip (manufactured by Idemitsu Kosan Co., Ltd.)) can be cited. Among them, it is preferred to use hydroxyl-terminated polybutadiene mainly having 1,2-repeat units or hydroxyl-terminated polyisoprene. Further, when considering gelation during the reaction with isocyanate or the heat resistance of the product, etc., a polyol having hydroxyl groups at both ends is preferred. Regarding the molecular weight, if it is too low, there is a possibility that the physical property values expected for the fiber treating agent for rubber reinforcement cannot be exhibited, and conversely, if it is too high, there is a possibility of poor properties in terms of viscosity, etc. during the manufacture of the blocked isocyanate compound. Therefore, the number average molecular weight range of the polyol compound (b) is preferably 500 to 5000, more preferably 1000 to 4000. The number of hydroxyl groups per molecule is 1 to 10, preferably 2 to 4, more preferably 2. Further, only 1 kind of the polyol compound (b) can be used, or 2 or more kinds can be used in combination. The polyol compound (b) can be obtained, for example, by a method of hydrolyzing an unsaturated aliphatic hydrocarbon after hydration or epoxidation, a method of polymerizing a conjugated diene monomer such as 1,3-butadiene, isoprene, 1,3-pentadiene, chloroprene alone, or a mixture of two or more conjugated diene monomers, or a mixture of a conjugated diene monomer and a copolymerizable monomer such as styrene, acrylonitrile, acrylic acid, methacrylic acid, acrylate, methacrylate using a reaction initiator such as hydrogen peroxide or an azo compound having a functional group, and further by anionically polymerizing a conjugated diene monomer using a catalyst such as an alkali metal such as sodium or lithium, or a complex of an alkali metal and a polycyclic aromatic compound, and then reacting with an alkylene oxide, epichlorohydrin, etc., and treating with a protonic acid such as hydrochloric acid, sulfuric acid, acetic acid as needed. (c) Blocking agent (hereinafter referred to as "blocking agent (c)") The blocking agent refers to a compound having a function of inactivating (protecting) an isocyanate group by addition reaction to the isocyanate group to form a blocked isocyanate group, and on the other hand, detaching (deprotecting) from the blocked isocyanate group by heating etc. to regenerate the reaction activity to reform the isocyanate group. Examples of the blocking agent (c) include alcohol compounds, alkylphenol compounds, phenol compounds, active methylene compounds, thiol compounds, acid amide compounds, acid imide compounds, imidazole compounds, imidazoline compounds, pyrimidine compounds, guanidine compounds, triazole compounds, carbamine compounds, urea compounds, oxime compounds, amine compounds, imide compounds, imine compounds, pyrazole compounds, bisulfite salts, etc. Among them, acid amide compounds, active methylene compounds, oxime compounds, and pyrazole compounds are preferred, and ε-caprolactam, acetylacetone, diethyl malonate, methyl ethyl ketone oxime, cyclohexanone oxime, 3-methylpyrazole, 3,5-dimethylpyrazole, etc. are more preferred. The blocking agent (c) can be used alone or in combination of two or more. (d) Active hydrogen group-containing compound (hereinafter referred to as "active hydrogen group-containing compound (d)") The active hydrogen group-containing compound (d) is not particularly limited, and various alcohols, polyols, and amines containing an active hydrogen group can be cited. The active hydrogen group-containing alcohol is not particularly limited. For example, polyether monohydric alcohols obtained by adding an alkylene oxide (e.g., ethylene oxide, propylene oxide, butylene oxide, etc.) to methanol, ethanol, propanol, butanol, hexanol, octanol, etc. can be cited. These active hydrogen group-containing alcohols can be used alone or in combination of two or more. The polyol containing an active hydrogen group is not particularly limited, and examples thereof include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,2,2-trimethylpentanediol, 3,3-dihydroxymethylheptane, alkane (C7-20) diol, 1,3-, 1,4-cyclohexanedimethanol or a mixture thereof, 1,3-, 1,4-cyclohexanediol or a mixture thereof, hydrogenated bisphenol A, bisphenol A, diethylene glycol, triethylene glycol, dipropylene glycol and other divalent alcohols; glycerol, trimethylolpropane, triisopropanolamine and other trivalent alcohols; tetramethylolmethane (pentaerythritol), diglycerol and other tetravalent alcohols; xylitol and other pentavalent alcohols; sorbitol, mannitol, allitol, iditol, dulcitol, altritol, inositol, dipentaerythritol and other hexavalent alcohols; pyranose alcohol and other heptavalent alcohols; sucrose and other octavalent alcohols; polyoxyethylene glycol, polyoxyethylene triol, random and / or block copolymers of alkylene oxides such as ethylene oxide and propylene oxide (for example, polypropylene glycol-polyethylene glycol copolymer diol or triol, polypropylene glycol-polyethylene glycol block polymer diol or triol, Pluronic (registered trademark) type polypropylene glycol or triol obtained by adding ethylene oxide to the end of polypropylene glycol, etc.), polyoxyethylene bisphenol A ether, polyoxypropylene trimethylolpropane ether, polytetramethylene ether polyol and other polyether polyols; adipic acid-based polyester polyol, phthalic acid-based polyester polyol, lactone-based polyester polyol and other polyester polyols; polycarbonate polyol, polyurethane polyol (polyol modified with urethane by polyisocyanate such as polyether polyol, polyester polyol, polycarbonate polyol, etc.), epoxy polyol, vegetable oil polyol, acrylic polyol, vinyl monomer-modified polyol and the like. These polyols containing an active hydrogen group may be used alone or in combination of two or more. The amine containing an active hydrogen group is not particularly limited, and diamine or polyamine can be specifically used. Examples of the diamine include ethylenediamine, trimethylenediamine, piperazine, isophorone diamine, etc., and examples of the polyamine include diethylenetriamine, dipropylenetriamine, triethylenetetramine, etc. These amines containing an active hydrogen group may be used alone or in combination of two or more. Among these active hydrogen group-containing compounds, hydrophilic compounds such as polyether monohydric alcohols obtained by adding ethylene oxide to methanol, ethanol, propanol, butanol, hexanol, octanol, etc., polyethylene glycol, polyoxyethylene triol, random and / or block copolymers of alkylene oxides such as ethylene oxide and propylene oxide (for example, polypropylene glycol-polyethylene glycol copolymer diol or triol, polypropylene glycol-polyethylene glycol block polymer diol or triol, Pluronic (registered trademark)-type polypropylene glycol or triol obtained by adding ethylene oxide to the end of polypropylene glycol, etc.) are used to introduce a hydrophilic group (such as oxyethylene group) into the molecular structure of a blocked isocyanate compound having a structure containing a carbon-carbon double bond in the molecule, so as to preferably impart self-emulsifying property (dispersion in water). Also, anionic or cationic hydrophilic groups can be used. The number average molecular weight of these hydrophilic compounds is preferably 300 to 5000. These hydrophilic compounds can be used alone or in combination of two or more. The introduction amount of these compounds for imparting self-emulsifying property is preferably not less than 1 mol% and preferably not more than 50 mol%, more preferably not more than 40 mol%, still more preferably not more than 30 mol% based on the total amount of isocyanate groups for reaction. The reaction conditions for synthesizing the blocked isocyanate compound having a structure containing a carbon-carbon double bond in the molecule are not particularly limited. For example, it can be carried out at a reaction temperature of 0 °C or higher and 150 °C or lower, preferably 30 °C or higher and 100 °C or lower, under atmospheric pressure, under pressure conditions, or in an inert gas (such as nitrogen, argon, etc.) atmosphere. Also, the reaction time is, for example, 0.5 hours or more and 120 hours or less, preferably 1 hour or more and 72 hours or less. The reaction can also be carried out without a solvent during synthesis, or in solvents such as ketones (e.g., acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone), nitriles (e.g., acetonitrile), alkyl esters (e.g., methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate), aliphatic hydrocarbons (e.g., n-hexane, n-heptane, octane), cycloaliphatic hydrocarbons (e.g., cyclohexane, methylcyclohexane), aromatic hydrocarbons (e.g., toluene, xylene, ethylbenzene), glycol ether esters (e.g., methyl cellosolve acetate, ethyl cellosolve acetate, methyl carbitol acetate, ethyl carbitol acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, 3-methyl-3-methoxybutyl acetate, ethyl 3-ethoxypropionate), ethers (e.g., diethyl ether, tetrahydrofuran, dioxane, 1,2-dimethoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether), halogenated aliphatic hydrocarbons (e.g., chloromethane, dichloromethane, chloroform, carbon tetrachloride, bromomethane, diiodomethane, dichloroethane), polar aprotic solvents (e.g., N-methylpyrrolidone, dimethylformamide, N,N'-dimethylacetamide, dimethyl sulfoxide, hexamethyl phosphonylamide), and conventional solvents such as propylene glycol 1-monomethyl ether 2-acetate. Additionally, a synthetic catalyst can be used as needed. By reacting the raw material components under such conditions, a part of the isocyanate groups of the polyisocyanate compound (a) is reacted with the polyol compound (b) and, if necessary, the active hydrogen-containing compound (d) to obtain a prepolymer with unreacted isocyanate groups remaining. Subsequently, the resulting prepolymer is subjected to an addition reaction with the blocking agent (c) in a manner that inactivates the remaining isocyanate groups, thereby obtaining a blocked isocyanate. Furthermore, the reaction sequence is not limited to the above. For example, a blocked isocyanate compound can be obtained by first reacting the polyisocyanate compound (a) with the active hydrogen-containing compound (d) and the blocking agent (c) in a ratio that leaves unreacted isocyanate groups, and then reacting with the polyol compound (b). Or, for example, a blocked isocyanate compound can also be obtained by first reacting the polyisocyanate compound (a) with the blocking agent (c) in a ratio that leaves unreacted isocyanate groups, and then reacting with the polyol compound (b) and the active hydrogen-containing compound (d). In this way, the polyisocyanate compound (a), the polyol compound (b), the blocking agent (c), and, if necessary, the active hydrogen-containing compound (d) can be reacted in various sequences to obtain a blocked isocyanate compound. Moreover, at the end of the reaction, it can be determined by measuring and confirming the isocyanate group concentration in the reaction solution according to Method A of JIS K 1603-1:2007, for example. The crosslinking agent composition of the present invention containing a blocked isocyanate compound having a structure containing a carbon-carbon double bond in the molecule preferably has the characteristics of a water-dispersible blocked isocyanate. As described above, when a hydrophilic compound is used as the active hydrogen-containing compound (d), a hydrophilic group can be introduced into the molecular structure of the blocked isocyanate compound having a structure containing a carbon-carbon double bond in the molecule, and self-emulsifying properties (dispersibility in water) can be imparted. Such a self-emulsifying blocked isocyanate compound can be made into a water-dispersible blocked isocyanate by a method of dispersing it in the following aqueous medium in the presence of an emulsifier or the like as needed. Also, the blocked isocyanate compound having a structure containing a carbon-carbon double bond in the molecule can be dispersed in an aqueous medium by applying mechanical shear force in the presence of an emulsifier or the like as needed to obtain a water-dispersible blocked isocyanate. Furthermore, the blocked isocyanate compound as the dispersoid exists as a solid at room temperature or as a liquid at room temperature depending on its chemical structure. Generally, "suspension (suspended matter)" or "emulsion (emulsified product)" is used as the name for its dispersion state in an aqueous medium, but in the present invention, it is not distinguished and is called "water-dispersible blocked isocyanate". The method for obtaining a water-dispersible blocked isocyanate is not particularly limited. For example, a method of stirring and mixing the blocked isocyanate compound and water or the following aqueous medium using a stirring base such as a homomixer, a homogenizer, a homogenizing machine, a magnetic stirrer, etc., or a method of filling glass beads, zirconia beads, etc. into a dispersing machine such as a ball mill, a horizontal sand mixer, a vertical sand mixer, a grinder, a bead mill, etc. and performing high-speed stirring to disperse it, etc. Thereafter, if necessary, when the aqueous dispersion of the blocked isocyanate compound contains an unwanted volatile organic solvent, the organic solvent can also be volatilized and removed by, for example, reducing the pressure or heating under reduced pressure of the aqueous dispersion of the blocked isocyanate. For the water-dispersible blocked isocyanate obtained as such and used as the crosslinking agent composition of the present invention, the solid content concentration of the blocked isocyanate compound is not particularly limited, and examples thereof include 5 to 70% by mass. Also, the particle size of the dispersed particles of the blocked isocyanate compound is not particularly limited. For example, the volume average particle size is 10,000 nm or less, preferably 1,000 nm or less, more preferably 700 nm or less, still more preferably 500 nm or less, and usually 50 nm or more. When the particle size of the dispersed particles of the blocked isocyanate compound is within this range, excellent dispersion stability can be ensured. Also, in the crosslinking agent composition of the present invention, additives such as a dispersant and an antifoaming agent can be appropriately added as needed. The crosslinking agent composition of the present invention is used for the production of a rubber-reinforcing fiber treatment agent containing no resorcinol and formaldehyde. Therefore, the crosslinking agent composition also contains no resorcinol and formaldehyde. The fiber treating agent for rubber reinforcement of the present invention (hereinafter, also referred to as "the treating agent of the present invention") contains a rubber latex and the crosslinking agent composition of the present invention, and does not contain resorcinol and formaldehyde. It is preferable that the treating agent of the present invention further contains an epoxy compound and / or a blocked isocyanate compound having no structure containing a carbon-carbon double bond in the molecule. Moreover, it is preferable to contain a liquid medium and to be in a liquid state. By subjecting the surface of the fiber to an adhesion treatment using the treating agent of the present invention, a fiber for rubber reinforcement can be obtained. Furthermore, the treating agent of the present invention may also be a kit of two treating agents. The first aspect of the kit of the fiber treating agent for rubber reinforcement of the present invention (hereinafter, also referred to as "the treating agent kit 1 of the present invention") includes: treating agent 1 containing an epoxy compound and a blocked isocyanate compound having no structure containing a carbon-carbon double bond in the molecule, and treating agent 2 containing a rubber latex and the crosslinking agent composition of the present invention, and does not contain resorcinol and formaldehyde. It is preferable that treating agents 1 and 2 further contain a liquid medium respectively. The second aspect of the kit of the treating agent of the present invention (hereinafter, also referred to as "the treating agent kit 2 of the present invention") includes: treating agent 3 containing an epoxy compound and the crosslinking agent composition of the present invention, and treating agent 4 containing a rubber latex and a blocked isocyanate compound having no structure containing a carbon-carbon double bond in the molecule, and does not contain resorcinol and formaldehyde. It is preferable that treating agents 3 and 4 further contain a liquid medium respectively. Hereinafter, both "the treating agent kit 1 of the present invention" and "the treating agent kit 2 of the present invention" are referred to as "the treating agent kit of the present invention". The crosslinking agent composition, the fiber treating agent for rubber reinforcement, and the kit of the fiber treating agent for rubber reinforcement of the present invention do not contain resorcinol and formaldehyde. "Not containing resorcinol and formaldehyde" in the present invention means that in addition to substantially not containing resorcinol or formaldehyde, or both of them, it also substantially does not contain a resorcinol-formaldehyde initial condensate obtained by condensing resorcinol and formaldehyde. "Substantially not containing" these compounds means that the content of each compound is less than 0.1% by mass. It is preferably less than 0.01% by mass, and most preferably 0% by mass (not detected). The crosslinking agent composition, the treating agent, and the treating agent kit that substantially do not contain resorcinol, formaldehyde, and the resorcinol-formaldehyde initial condensate obtained by condensing resorcinol and formaldehyde can be produced by using raw materials that substantially do not contain resorcinol, formaldehyde, and the resorcinol-formaldehyde initial condensate, or that do not generate them in the manufacturing process. The liquid medium is preferably an aqueous medium. An aqueous medium refers to a liquid medium containing 50% by mass or more of water. As the water used, purified water from which impurities have been removed is preferred, but as long as the effects of the present invention can be produced, industrial water or tap water, etc. can also be used. In addition to water, the aqueous medium may also contain other liquid media. In addition to water, the liquid medium may also contain water-soluble organic solvents such as monoalcohols, polyols, alcohol ethers, and glycol esters, and can be selected as needed from media with low toxicity and whose working environment will not deteriorate due to volatile vapors, etc. Rubber latex Rubber latex has the characteristic that the rubber component is emulsified and dispersed in an aqueous medium. Examples thereof include natural rubber latex, styrene-butadiene copolymer rubber latex, carboxyl-modified styrene-butadiene copolymer rubber latex, vinylpyridine-styrene-butadiene copolymer rubber latex, nitrile rubber latex, chloroprene rubber latex, etc. Among these, styrene-butadiene copolymer rubber latex, carboxyl-modified styrene-butadiene copolymer rubber latex, and vinylpyridine-styrene-butadiene copolymer rubber latex are preferred, and vinylpyridine-styrene-butadiene copolymer rubber latex is more preferred. Also, only one kind can be used, or two or more kinds can be used in combination. As for the vinylpyridine-styrene-butadiene copolymer latex, the content of the monomers used in the polymerization is preferably 0.5 to 30% by mass of vinylpyridine, 10 to 60% by mass of styrene, and 30 to 80% by mass of butadiene. Preferably, a vinylpyridine-styrene-butadiene copolymer latex having a double structure can also be used, which can be obtained by polymerizing a monomer mixture composed of 0.5 to 15% by mass of vinylpyridine, 30 to 60% by mass of styrene, and less than 60% by mass of butadiene, and then polymerizing a monomer mixture composed of 5 to 20% by mass of vinylpyridine, 10 to 40% by mass of styrene, and 45 to 75% by mass of butadiene. Also, it can be a copolymer latex further using monomers other than vinylpyridine, styrene, and butadiene. When two rubber latexes are used in combination, it is preferred to use vinylpyridine-styrene-butadiene copolymer rubber latex and styrene-butadiene copolymer latex. In this case, the mixing ratio of the two latexes is not particularly limited. For example, the mass ratio of the solid components of vinylpyridine-styrene-butadiene copolymer rubber latex and styrene-butadiene copolymer latex is preferably 40:60 to 95:5, and more preferably 60:40 to 90:10. Epoxy compounds As epoxy compounds, examples include glycidyl ethers such as ethylene glycol glycidyl ether, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, bisphenol A diglycidyl ether, bisphenol S diglycidyl ether, novolac glycidyl ether, brominated bisphenol A diglycidyl ether; glycidyl esters such as hexahydrophthalic acid glycidyl ester, dimer acid glycidyl ester; glycidyl amines such as triglycidyl isocyanurate, glycidyl hydantoins, tetraglycidyl diaminodiphenylmethane, triglycidyl para-aminophenol, triglycidyl meta-aminophenol, diglycidyl aniline, diglycidyl toluidine, tetraglycidyl meta-xylene diamine, diglycidyl tribromoaniline, tetraglycidyl bisaminomethyl cyclohexane; alicyclic or aliphatic epoxides such as 3,4-epoxycyclohexylmethyl carboxylate, epoxidized polybutadiene, epoxidized soybean oil. Among these, ethylene glycol glycidyl ether, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, sorbitol polyglycidyl ether, and polyglycerol polyglycidyl ether, which are compounds with good solubility in aqueous media, are preferred. As commercially available products, it is preferable to use the DENACOL (registered trademark) series manufactured by Nagase ChemteX Corporation, etc. Also, it can be used alone or in combination of two or more kinds. Blocked isocyanate compounds having no structure containing a carbon-carbon double bond in the molecule A blocked isocyanate compound having no structure containing a carbon-carbon double bond in the molecule is a compound having a blocked isocyanate group in the molecule and having no structure containing a carbon-carbon double bond (excluding the epoxy compounds used in the present invention). For example, it can be obtained by an addition reaction of the isocyanate group of a polyisocyanate compound having no structure containing a carbon-carbon double bond in the molecule with a conventional blocking agent. It is preferable that the blocked isocyanate compound has a plurality of blocked isocyanate groups in the molecule. The blocked isocyanate compound having no structure containing a carbon-carbon double bond in the molecule is synthesized in the same steps except that component (b) is not used in the synthesis of the blocked isocyanate compound having a structure containing a carbon-carbon double bond in the molecule described above. Specifically, for example, it is synthesized by reacting the following raw material components (a), (c), and, if necessary, (d). (a) Polyisocyanate compound (c) Blocking agent (d) Active hydrogen-containing compound (however, excluding the above components (a) and (c)) For each raw material component, the same components as those used in the synthesis of the blocked isocyanate compound having a structure containing a carbon-carbon double bond in the molecule described above can be used, and the following are preferred. As the polyisocyanate compound (a), aliphatic polyisocyanates and their derivatives, aromatic polyisocyanates and their derivatives are preferred, and 1,6 - hexamethylene diisocyanate and its derivatives, diphenylmethane diisocyanate (4,4'- , 2,4'- , 2,2'- diphenylmethane diisocyanate or a mixture of two or more thereof) (MDI) and its derivatives, polymethylene polyphenyl polyisocyanate (crude MDI, polymeric MDI), etc. are more preferred. As the blocking agent (c), amide - based compounds, oxime - based compounds, pyrazole - based compounds are preferred, and ε - caprolactam, methyl ethyl ketoxime, cyclohexanone oxime, 3 - methylpyrazole, 3,5 - dimethylpyrazole, etc. are more preferred. As the active hydrogen - containing compound (d), polyether polyols are preferred, and polyoxyethylene bisphenol A ether, etc. are more preferred. Further, as the hydrophilic compound, for example, it is possible to use amine sulfonic acids such as taurine, N - methyltaurine, N - butyltaurine, sulfanilic acid, amine carboxylic acids such as glycine, alanine, etc. The anionic - forming groups are converted into bases by organic bases such as primary, secondary and tertiary amines such as ethylamine, triethylamine, dimethylamine, pyridine, hydroxyalkylated amines such as ethanolamine, diethanolamine, triethanolamine, etc. or ammonia; hydroxides of monovalent metals such as potassium hydroxide, sodium hydroxide; carbonates of monovalent metals such as sodium bicarbonate, potassium carbonate, etc. Among them, the sodium salt of taurine is more preferred. When using the blocked isocyanate compound synthesized from these raw material components, a fiber - treating agent for rubber reinforcement with excellent adhesion between the rubber - reinforcing fiber and the rubber composition can be obtained. As the reaction conditions for manufacturing the blocked isocyanate compound that does not have a structure containing a carbon - carbon double bond in the molecule, the reaction conditions and methods for manufacturing the blocked isocyanate compound that has a structure containing a carbon - carbon double bond in the molecule can be applied mutatis mutandis. Also, the blocked isocyanate compound that does not have a structure containing a carbon - carbon double bond in the molecule preferably has the characteristics of a water - dispersible blocked isocyanate. For the method of obtaining a water - dispersible blocked isocyanate, the method of obtaining the water - dispersible blocked isocyanate of the blocked isocyanate compound that has a structure containing a carbon - carbon double bond in the molecule can be applied mutatis mutandis. The treating agent of the present invention can be obtained, for example, by mixing a rubber latex and the cross - linking agent composition of the present invention in an aqueous medium, further adding an epoxy compound and / or a blocked isocyanate compound that does not have a structure containing a carbon - carbon double bond in the molecule, or the following additives as needed, and additionally adding an aqueous medium, etc. The mixing order or addition order of these can be appropriately adjusted. The treating agent of the present invention can be directly used as a processing liquid when performing an adhesion treatment on the fiber, or can be appropriately diluted from a high - concentration stock solution state when performing the adhesion treatment to be used as a processing liquid. When the treating agent of the present invention is used in a processing liquid for adhesion treatment of fibers, the concentration of the solid components (non-volatile components other than the aqueous medium) can be appropriately adjusted according to the processing method or the desired adhesion amount of the solid components to the fibers. For example, it is about 0.1 to 50% by mass, preferably 1 to 30% by mass, and more preferably 5 to 25% by mass. The content ratio of each constituent component in the solid components contained in the treating agent of the present invention can be appropriately adjusted according to the type of fibers used, the composition of the rubber composition, the resulting adhesiveness, etc. For example, the amount of rubber latex (solid component) in the solid components is preferably 50 to 95% by mass, and the amounts of the blocked isocyanate compound (solid component) having a structure containing a carbon-carbon double bond in the molecule, the epoxy compound, and the blocked isocyanate compound (solid component) not having a structure containing a carbon-carbon double bond in the molecule are each preferably 0.1 to 30% by mass. In order to exert the effects of the object of the present invention, in the treating agent of the present invention, the content of the blocked isocyanate compound having a structure containing a carbon-carbon double bond in the molecule is preferably 0.5 to 25 parts by mass relative to 100 parts by mass of the content of the rubber latex. In the treating agent of the present invention, when the epoxy group of the epoxy compound, the blocked isocyanate group of the blocked isocyanate compound having a structure containing a carbon-carbon double bond in the molecule, and the blocked isocyanate group of the blocked isocyanate compound not having a structure containing a carbon-carbon double bond in the molecule are contained as the functional groups of the constituent components, the relative contents thereof have a preferred range. In 1 kg of the treating agent when the solid component concentration of the treating agent of the present invention is converted to 20% by mass, the amount (mmol) of the epoxy group and the amount (mmol) of the blocked isocyanate group contained therein are calculated, and the value obtained by subtracting the amount of the blocked isocyanate group from the amount of the epoxy group is preferably -30 to 10 mmol. That is, for the fiber treating agent for rubber reinforcement (solid component concentration Z 1 % by mass), the amount of the epoxy group and the amount of the blocked isocyanate group are preferably such that the following formula (1) is satisfied: -30 ≦ (X 1 - Y 1 ) × 20 / Z 1 ≦ 10 (1) [In the formula, X 1 : the amount (mmol) of the epoxy group contained in the treating agent (1 kg) Y 1 : the amount (mmol) of the blocked isocyanate group contained in the treating agent (1 kg)]. The amount X of the epoxy group contained in 1 kg of the treating agent 1(mmol) is the value calculated from the amount of the epoxy compound contained in 1 kg of the self-treating agent and its epoxy equivalent, and the amount Y of the blocked isocyanate group 1 (mmol) is the value calculated from the amount of each blocked isocyanate compound contained in 1 kg of the self-treating agent and its blocked isocyanate group content rate. The treating agent 1 included in the treating agent set 1 of the present invention can be obtained, for example, by mixing an epoxy compound and a blocked isocyanate compound having no structure containing a carbon-carbon double bond in its molecule in an aqueous medium, further adding the following additives as needed, and additionally adding an aqueous medium, etc. The treating agent 2 included in the treating agent set 1 of the present invention can be obtained, for example, by mixing a rubber latex and the crosslinking agent composition of the present invention in an aqueous medium, further adding the following additives as needed, and additionally adding an aqueous medium, etc. The mixing order or addition order of these can be appropriately adjusted. The treating agent 1 and the treating agent 2 included in the treating agent set 1 of the present invention can be directly used as a processing liquid when performing an adhesion treatment on fibers, or can be appropriately diluted from a high-concentration stock liquid state when performing the adhesion treatment to be used as a processing liquid. When the treating agent 1 is used as a processing liquid for performing an adhesion treatment on fibers, the concentration of its solid components (non-volatile components other than the aqueous medium) can be appropriately adjusted according to the processing method or the desired adhesion amount of the solid components to the fibers, for example, it is about 0.1 to 20% by mass, preferably 1 to 5% by mass. The content ratio of each constituent component in the solid components contained in the treating agent 1 can be appropriately adjusted according to the type of fiber used, the composition of the rubber composition, the adhesiveness obtained, etc. For example, the amount of the epoxy compound in the solid components is preferably 10 to 90% by mass, and the amount of the blocked isocyanate compound (solid components) having no structure containing a carbon-carbon double bond in its molecule is preferably 10 to 90% by mass. When the treating agent 2 is used as a processing liquid for performing an adhesion treatment on fibers, the concentration of its solid components (non-volatile components other than the aqueous medium) can be appropriately adjusted according to the processing method or the desired adhesion amount of the solid components to the fibers, for example, it is about 0.1 to 50% by mass, preferably 10 to 30% by mass. The content ratio of each constituent component in the solid components contained in the treating agent 2 can be appropriately adjusted according to the type of fiber used, the composition of the rubber composition, the adhesiveness obtained, etc. For example, the amount of the rubber latex (solid components) in the solid components is preferably 70 to 99.95% by mass, and the amount of the blocked isocyanate compound (solid components) having a structure containing a carbon-carbon double bond in its molecule is preferably 0.05 to 30% by mass. In order to achieve the effects of the present invention, in the treating agent 2, the content of the blocked isocyanate compound having a structure containing a carbon-carbon double bond in the molecule is preferably 0.5 to 20 parts by mass relative to 100 parts by mass of the content of the rubber latex. In the treating agent 1, an epoxy group of an epoxy compound and a blocked isocyanate group of a blocked isocyanate compound having no structure containing a carbon-carbon double bond in the molecule are contained as functional groups of the constituent components. When the treating agent 2 contains a blocked isocyanate group of a blocked isocyanate compound having a structure containing a carbon-carbon double bond in the molecule as a functional group of the constituent component, the relative content thereof has a preferable range. In a total of 2 kg obtained by combining 1 kg of the treating agent 1 converted to a solid content concentration of 2% by mass and 1 kg of the treating agent 2 converted to a solid content concentration of 20% by mass, the amount (mmol) of the epoxy group and the amount (mmol) of the blocked isocyanate group contained therein are calculated, and the value obtained by subtracting the amount of the blocked isocyanate group from the amount of the epoxy group is preferably 20 to 70 mmol. That is, for the treating agent 1 (solid content concentration Z 2 % by mass) and the treating agent 2 (solid content concentration Z 3 % by mass), the amount of the epoxy group and the amount of the blocked isocyanate group are preferably such that the following formula (2) is satisfied: 20 ≦ [X 2 ×2 / Z 2 -(Y 2 ×2 / Z 2 +Y 3 ×20 / Z 3 )] ≦ 70 (2) [In the formula, X 2 : the amount (mmol) of the epoxy group contained in the treating agent 1 (1 kg) Y 2 : the amount (mmol) of the blocked isocyanate group contained in the treating agent 1 (1 kg) Y 3 : the amount (mmol) of the blocked isocyanate group contained in the treating agent 2 (1 kg)]. Here, the solid content concentration or amount of the treating agent 1 or the treating agent 2 is only set for calculating the amount of each functional group, and in fact, it is not necessary to mix the treating agent 1 and the treating agent 2. The amount of the epoxy group or the amount of the blocked isocyanate group is a value calculated in the same manner as in the case of the treating agent of the present invention described above. The treating agent 3 included in the treating agent set 2 of the present invention can be obtained, for example, by mixing an epoxy compound with the crosslinking agent composition of the present invention in an aqueous medium, further adding the following additives as needed, and additionally adding an aqueous medium, etc. The treating agent 4 included in the treating agent set 2 of the present invention can be obtained, for example, by mixing a rubber latex with a blocked isocyanate compound having no carbon-carbon double bond-containing structure in its molecule in an aqueous medium, further adding the following additives as needed, and additionally adding an aqueous medium, etc. The mixing order or addition order of these can be appropriately adjusted. The treating agent 3 and treating agent 4 included in the treating agent set 2 of the present invention can be directly used as a processing liquid for attaching to fibers, or can be appropriately diluted from a high-concentration stock solution state during the attaching treatment to be used as a processing liquid. When the treating agent 3 is used as a processing liquid for attaching to fibers, the concentration of its solid components (non-volatile components other than the aqueous medium) can be appropriately adjusted according to the processing method or the desired amount of solid components to be attached to the fibers. For example, it is about 0.1 to 20% by mass, preferably 1 to 5% by mass. The content ratio of each constituent component in the solid components contained in the treating agent 3 can be appropriately adjusted according to the type of fiber used, the composition of the rubber composition, the resulting adhesiveness, etc. For example, the amount of the epoxy compound in the solid components is preferably 10 to 90% by mass, and the amount of the blocked isocyanate compound having a carbon-carbon double bond-containing structure in its molecule (solid component) is preferably 10 to 90% by mass. When the treating agent 4 is used as a processing liquid for attaching to fibers, the concentration of its solid components (non-volatile components other than the aqueous medium) can be appropriately adjusted according to the processing method or the desired amount of solid components to be attached to the fibers. For example, it is about 0.1 to 50% by mass, preferably 10 to 30% by mass. The content ratio of each constituent component in the solid components contained in the treating agent 4 can be appropriately adjusted according to the type of fiber used, the composition of the rubber composition, the resulting adhesiveness, etc. For example, the amount of the rubber latex (solid component) in the solid components is preferably 70 to 99.95% by mass, and the amount of the blocked isocyanate compound having no carbon-carbon double bond-containing structure in its molecule (solid component) is preferably 0.05 to 30% by mass. As long as the effects of the present invention can be produced, the treating agent of the present invention, or the treating agents 1 to 4 of the treating agent set may also contain arbitrary additives. Examples of additives include resin components or crosslinking agents other than the essential constituent components of the present invention, surfactants, antioxidants, ultraviolet absorbers, pigments, metal powder pigments, rheology control agents, curing accelerators, plasticizers, flame retardants, antistatic agents, deodorants, antibacterial agents, etc. The fiber for reinforcing rubber of the present invention has an adhesive composition obtained by heat-treating a composition adhered to the fiber surface. The composition contains a rubber latex and the crosslinking agent composition of the present invention. It is preferable that the composition containing the rubber latex and the crosslinking agent composition of the present invention further contains an epoxy compound and / or a blocked isocyanate compound having no structure containing a carbon-carbon double bond in the molecule. Furthermore, in the present invention, the "adhesive composition" refers to a composition that can impart good adhesion performance between the fiber for reinforcing rubber and the rubber composition when it becomes the final rubber product, and it does not necessarily need to have adhesiveness such as an adhesive or a tackifier itself. Also, although the rubber latex has the property that the rubber component can be emulsified and dispersed in an aqueous medium as described above, in the adhesive composition, the aqueous medium is volatilized and removed, so the rubber latex in the adhesive composition does not need to maintain such a property. In addition, since it is currently impossible or almost impractically difficult to completely specify the structure of the "adhesive composition", the invention of the fiber for reinforcing rubber is specified by the manufacturing method. As the fiber used as the fiber for reinforcing rubber of the present invention, when used in rubber products with high strength requirements such as tires, power transmission belts, or high-pressure hoses, it is preferable to have an organic fiber twisted into a cord-like shape. Also, when used in sheet-shaped rubber products such as building rubber sheets, a shape in which ropes are arranged in a net shape or a woven shape can be used. The material of the organic fiber is not particularly limited, and examples include polyolefins such as nylon, polyester, aramid (aromatic polyamide), rayon, polypropylene, or polyethylene, polycarbonate, polyacrylate, ABS resin, vinyl chloride resin, etc. Among these, it is preferable that the fiber contains any one of polyester, nylon, and aramid. In the case of using polyester or aramid, which is difficult to adhere to the rubber composition by the usual method, the effect of the present invention can be more significantly exhibited. Also, when the fiber used in the fiber for reinforcing rubber of the present invention contains aramid, as the additive contained in the treatment agent or treatment agents 1 to 4 of the treatment agent set of the present invention, by using the synthetic bentonite described in Japanese Patent Laid-Open No. 9-21073 or the carbon black described in Japanese Patent Laid-Open No. 2009-127149, the effect of the present invention can be more significantly exhibited. The fiber for rubber reinforcement of the present invention can be manufactured by attaching a processing liquid containing the treating agent of the present invention to the fiber and then applying a drying treatment and a heating treatment. As the attachment treatment method, for example, dipping, brushing, casting, spraying, roll coating, knife coating, etc. can be mentioned, and among them, dipping treatment is preferably used. The temperature during the drying treatment is preferably 60 to 200 °C, more preferably 80 to 150 °C. The drying time is preferably 20 seconds to 10 minutes, more preferably 30 seconds to 5 minutes. The temperature during the heating treatment is preferably 100 to 280 °C, more preferably 150 to 260 °C. The heating time is preferably 20 seconds to 10 minutes, more preferably 30 seconds to 5 minutes. A single treatment combining the drying treatment and the heating treatment can also be carried out. The device used for the drying treatment or the heating treatment is not particularly limited, and a heating device with warm air, infrared rays, or high frequency can be used, etc. By manufacturing the fiber for rubber reinforcement of the present invention in this way, it becomes a state where an adhesive composition generated from the constituent components of the treating agent of the present invention adheres to the fiber surface. The adhesion amount of the solid component of the adhesive composition to the fiber can be appropriately adjusted according to the type of fiber used, the composition of the rubber composition, the desired adhesiveness, etc. When expressed as an adhesion rate (the ratio of the mass of the solid component of the adhered adhesive composition to the mass of the fiber before treatment), for example, 1 to 20% by mass can be mentioned. In the case of using the treating agent set 1 of the present invention, the manufacturing method of the fiber for rubber reinforcement of the present invention has a two-stage step of first performing a treatment of attaching a processing liquid containing treating agent 1 to the fiber and then performing a treatment of attaching a processing liquid containing treating agent 2. After the treatment of attaching the processing liquid containing treating agent 1 and before the treatment of attaching the processing liquid containing treating agent 2, a drying treatment and a heating treatment are applied, and it is preferable to apply a drying treatment and a heating treatment also after the treatment of attaching the processing liquid containing treating agent 2. The methods, devices, conditions, etc. of the attachment treatment, drying treatment, heating treatment, etc. are the same as those described above. In the case of using the treating agent set 2 of the present invention, the manufacturing method of the fiber for rubber reinforcement of the present invention has a two-stage step of first performing a treatment of attaching a processing liquid containing treating agent 3 to the fiber and then performing a treatment of attaching a processing liquid containing treating agent 4. After the treatment of attaching the processing liquid containing treating agent 3 and before the treatment of attaching the processing liquid containing treating agent 4, a drying treatment and a heating treatment are applied, and it is preferable to apply a drying treatment and a heating treatment also after the treatment of attaching the processing liquid containing treating agent 4. The methods, devices, conditions, etc. of the attachment treatment, drying treatment, heating treatment, etc. are the same as those described above. The rubber product of the present invention contains the fiber for reinforcing rubber of the present invention. Such a rubber product can be obtained, for example, by embedding the fiber for reinforcing rubber of the present invention in unvulcanized rubber and subjecting the unvulcanized rubber to a vulcanization treatment to form a rubber composition, and has excellent adhesion between the rubber composition and the fiber for reinforcing rubber. Such a rubber product can itself be a final product such as a tire, a power transmission belt, a hose, or a rubber sheet for a building, or the rubber composition can be attached to the surface of the fiber for reinforcing rubber to form a cord or sheet shape and used as an element for reinforcing the final rubber product. The rubber component contained in the rubber composition is not particularly limited, and examples thereof include natural rubber (NR), polyisoprene rubber (IR), polybutadiene rubber (BR), styrene-butadiene copolymer rubber (SBR), acrylonitrile-butadiene rubber (NBR), chloroprene rubber (CR), butyl rubber (IIR) and other conjugated diene synthetic rubbers, ethylene-propylene copolymer rubber (EPM), ethylene-propylene-diene copolymer rubber (EPDM), polysiloxane rubber and the like. It can be used alone or in combination of two or more. Examples of the vulcanizing agent used for the vulcanization treatment of the unvulcanized rubber include sulfur, tetramethylthiuram disulfide, thiuram polysulfide compounds such as dipentamethylenethiuram tetrasulfide, 4,4-dithiomorpholine, p-benzoquinone dioxime, p,p'-dibenzoquinone dioxime, cyclic sulfimide, peroxide and the like. Furthermore, the rubber composition can be appropriately compounded with various compounding agents such as fillers such as carbon black, silica, and aluminum hydroxide, colorants, vulcanization accelerators, antioxidants, and softeners. The following is disclosed in this specification. [1] A crosslinking agent composition which is a crosslinking agent composition for a rubber reinforcing fiber treatment agent that does not contain resorcinol and formaldehyde, and which contains a blocked isocyanate compound having a structure containing a carbon-carbon double bond in the molecule. [2] The crosslinking agent composition as described in [1] above, wherein the structure containing a carbon-carbon double bond is a structure selected from a polybutadiene structure and a polyisoprene structure. [3] A rubber reinforcing fiber treatment agent which is a rubber reinforcing fiber treatment agent that does not contain resorcinol and formaldehyde, and which contains a rubber latex and the crosslinking agent composition as described in [1] or [2] above. [4] The rubber reinforcing fiber treatment agent as described in [3] above, which further contains an epoxy compound and / or a blocked isocyanate compound having no structure containing a carbon-carbon double bond in the molecule. [5] The rubber reinforcing fiber treatment agent as described in [3] or [4] above, wherein the content of the blocked isocyanate compound having a structure containing a carbon-carbon double bond in the molecule is 0.5 to 25 parts by mass relative to 100 parts by mass of the content of the rubber latex. [6] The rubber reinforcing fiber treatment agent as described in [4] or [5] above, wherein the amount of epoxy groups and the amount of blocked isocyanate groups contained in the rubber reinforcing fiber treatment agent (solid component concentration Z 1 % by mass) satisfy the following formula (1): -30 ≦ (X 1 -Y 1 ) × 20 / Z 1 ≦ 10 (1) [In the formula, X 1 : the amount of epoxy groups (mmol) contained in 1 kg of the treatment agent Y 1 : the amount of blocked isocyanate groups (mmol) contained in 1 kg of the treatment agent]. [7] A rubber reinforcing fiber treatment agent kit which is a rubber reinforcing fiber treatment agent kit that does not contain resorcinol and formaldehyde, and which includes: treatment agent 1 containing an epoxy compound and a blocked isocyanate compound having no structure containing a carbon-carbon double bond in the molecule, and treatment agent 2 containing a rubber latex and the crosslinking agent composition as described in [1] or [2] above. [8] The rubber reinforcing fiber treatment agent kit as described in [7] above, wherein in treatment agent 2, the content of the blocked isocyanate compound having a structure containing a carbon-carbon double bond in the molecule is 0.5 to 20 parts by mass relative to 100 parts by mass of the content of the rubber latex. [9] The rubber reinforcing fiber treatment agent kit as described in [7] or [8] above, wherein in treatment agent 1 (solid component concentration Z 2Mass %) and the amount of epoxy groups and blocked isocyanate groups in the above-mentioned treating agent 2 (solid component concentration Z 3 Mass %) satisfy the following formula (2): 20 ≦ [X 2 ×2 / Z 2 -(Y 2 ×2 / Z 2 +Y 3 ×20 / Z 3 )] ≦ 70 (2) [In the formula, X 2 : The amount (mmol) of epoxy groups contained in the above-mentioned treating agent 1 (1 kg) Y 2 : The amount (mmol) of blocked isocyanate groups contained in the above-mentioned treating agent 1 (1 kg) Y 3: The amount (mmol) of the blocked isocyanate groups contained in the above-mentioned treating agent 2 (1 kg).

[10] A method for producing a fiber for reinforcing rubber, which comprises the following steps: using the fiber treating agent kit for reinforcing rubber described in any one of the above [7] to [9], after performing the treatment of attaching the processing liquid containing the above-mentioned treating agent 1 to the fiber, performing the treatment of attaching the processing liquid containing the above-mentioned treating agent 2.

[11] A fiber treating agent kit for reinforcing rubber, which is a kit of fiber treating agents for reinforcing rubber that does not contain resorcinol and formaldehyde, and comprises: a treating agent 3 containing an epoxy compound and a crosslinking agent composition described in the above [1] or [2], and a treating agent 4 containing a rubber latex and a blocked isocyanate compound having no structure containing a carbon-carbon double bond in the molecule.

[12] A method for producing a fiber for reinforcing rubber, which comprises the following steps: using the fiber treating agent kit for reinforcing rubber described in the above

[11] , after performing the treatment of attaching the processing liquid containing the above-mentioned treating agent 3 to the fiber, performing the treatment of attaching the processing liquid containing the above-mentioned treating agent 4.

[13] A fiber for reinforcing rubber, on the surface of which an adhesive composition obtained by heat-treating a composition is attached, the composition containing a rubber latex and the crosslinking agent composition described in the above [1] or [2].

[14] The fiber for reinforcing rubber described in the above

[13] , wherein the composition containing the rubber latex and the crosslinking agent composition further contains an epoxy compound and / or a blocked isocyanate compound having no structure containing a carbon-carbon double bond in the molecule.

[15] The fiber for reinforcing rubber described in the above

[13] or

[14] , wherein the fiber comprises any one of polyester, nylon, and aramid.

[16] A rubber product containing the fiber for reinforcing rubber described in any one of the above

[13] to

[15] . [Examples] Hereinafter, the present invention will be further specifically described by way of examples, but the present invention is not limited by these examples. Furthermore, in the examples, unless otherwise specified, "parts" means parts by mass, and "%" means mass %. <Description of Raw Materials> (Those without the solid component concentration indicated are at a concentration of 100%) - DURANATE (registered trademark) 24A-100: Biuret of hexamethylene diisocyanate, concentration (content rate) of isocyanate group 23.5%, manufactured by Asahi Kasei Corporation - NISSO-PB G-1000: Polybutadiene glycol, number average molecular weight 1400, manufactured by Nippon Soda Co., Ltd. - Poly ip: Liquid polyisoprene with a hydroxyl group at the end, number average molecular weight 2500, manufactured by Idemitsu Kosan Co., Ltd. - NEOSTANN (registered trademark) U-600: Bismuth-based catalyst, manufactured by Nitto Kasei Co., Ltd. - 3,5-Dimethylpyrazole: Manufactured by Otsuka Chemical Co., Ltd. - JEFFAMINE (registered trademark) M-1000: Methoxypoly(oxyethylene / oxypropylene)-2-propylamine, number average molecular weight 1000, manufactured by Huntsman - EPAN (registered trademark) 680: Pluronic (registered trademark) type nonionic surfactant, number average molecular weight 8750, weight fraction of ethylene oxide 80%, manufactured by Daiichi Kogyo Seiyaku Co., Ltd. - Millionate (registered trademark) MR-200: Polymethylene polyphenyl polyisocyanate, concentration (content rate) of isocyanate group 31.5%, manufactured by Tosoh Corporation - NEWPOL (registered trademark) BPE-40: Ethylene oxide 4-mole adduct of bisphenol A, manufactured by Sanyo Chemical Industries, Ltd. - Butyl glycol ether: Ethylene glycol monobutyl ether, manufactured by Tokyo Chemical Industry Co., Ltd. - Disponil (registered trademark) SUS87: Sodium sulfosuccinate, manufactured by BASF - DENACOL EX-313: Glycerol polyglycidyl ether, epoxy equivalent 141 g / eq, manufactured by Nagase ChemteX Corporation - DENACOL EX-614: Sorbitol polyglycidyl ether, epoxy equivalent 167 g / eq, manufactured by Nagase ChemteX Corporation - PYRATEX (registered trademark)-LB: Vinylpyridine-styrene-butadiene copolymer latex, solid component concentration 38.8%, manufactured by NIPPON A&L Co., Ltd. - Nipol (registered trademark) LX-112: styrene-butadiene copolymer latex, solid content concentration 41%, manufactured by ZEON Corporation, Japan - NEOCOL (registered trademark) P: dioctyl sulfosuccinate, manufactured by Daiichi Kogyo Seiyaku Co., Ltd. - SUMIKANOL (registered trademark) 700S: resorcinol-formaldehyde initial condensate, solid content concentration 65%, manufactured by Sumitomo Chemical Co., Ltd. - DM-6400: MDI-type blocked isocyanate (no structure containing carbon-carbon double bond in the molecule), solid content concentration 42%, concentration of regenerated isocyanate group (isocyanate group when the blocking agent is removed from the water-dispersible blocked isocyanate) 7.90%, manufactured by Meisei Chemical Industry Co., Ltd. - SUMECTON (registered trademark)-ST: synthetic bentonite, manufactured by KUNIMINE Industries Co., Ltd. - FUJI SP BLACK 203: carbon black dispersion, solid content concentration 23.5%, manufactured by Fuji Pigment Co., Ltd. <Production of a water-dispersible blocked isocyanate compound having a structure containing a carbon-carbon double bond in the molecule> Production Example 1 200 g (amount of isocyanate group 1.119 mol) of DURANATE 24A-100, 261.1 g (amount of hydroxyl group 0.373 mol) of NISSO-PB G-1000, 37.3 g (amount of hydroxyl group 0.019 mol) of polyoxyethylene monomethyl ether (number average molecular weight 2000), 7.0 g (amount of hydroxyl group 0.050 mol) of polyoxypropylene trimethylolpropane ether (hydroxyl value 398 mgKOH / g), and 380 g of acetone were placed in a separable flask equipped with a stirrer, a condenser, and a thermometer, and mixed by stirring at room temperature. Next, the liquid temperature was raised to 60°C, 0.253 g of NEOSTANN U-600 was added, and the reaction was carried out until the concentration (content rate) of the isocyanate group in the reaction liquid measured by Method A of JIS K 1603-1:2007 became 3.2% (28.5 g). After the liquid temperature was cooled to 40°C, 65.1 g (amount of NH group 0.677 mol) of 3,5-dimethylpyrazole was added, and the reaction was carried out until the concentration of the isocyanate group became 0%. The liquid temperature was cooled to 30°C, and 1400 g of ion-exchanged water was dropped in with strong stirring to disperse it. Thereafter, acetone was distilled off under reduced pressure, and ion-exchanged water was added to make the concentration of the solid content (570.8 g) 30%, obtaining the water-dispersible blocked isocyanate of Production Example 1, which is an aspect of the crosslinking agent composition of the present invention. The concentration of the regenerated isocyanate group (isocyanate group when the blocking agent is removed from the water-dispersible blocked isocyanate) in the water-dispersible blocked isocyanate of Production Example 1 was 1.50%. Production Example 2: 35 g (amount of isocyanate group: 0.196 mol) of DURANATE 24A-100, 81.6 g (amount of hydroxyl group: 0.065 mol) of Poly ip, 6.5 g (amount of hydroxyl group: 0.003 mol) of polyoxyethylene monomethyl ether (number-average molecular weight 2000), 1.2 g (amount of hydroxyl group: 0.009 mol) of polyoxypropylene trimethylolpropane ether (hydroxyl value 398 mgKOH / g), and 90 g of acetone were charged into a separable flask equipped with a stirrer, a condenser, and a thermometer, and mixed by stirring at room temperature. Next, the liquid temperature was raised to 60 °C, 0.062 g of NEOSTANN U-600 was added, and the reaction was carried out until the concentration of the isocyanate group in the reaction liquid became 2.3%. After the liquid temperature was cooled to 40 °C, 11.4 g (amount of NH group: 0.119 mol) of 3,5-dimethylpyrazole was added, and the reaction was carried out until the concentration of the isocyanate group became 0%. The liquid temperature was cooled to 30 °C, and 300 g of ion-exchanged water was added dropwise with strong stirring to disperse it. Thereafter, acetone was distilled off under reduced pressure, and ion-exchanged water was added to make the solid content concentration 30%, thereby obtaining the water-dispersed blocked isocyanate of Production Example 2, which is an aspect of the crosslinking agent composition of the present invention. The concentration of the regenerated isocyanate group in the water-dispersed blocked isocyanate of Production Example 2 was 1.10%. <Production of a blocked isocyanate compound having no structure containing a carbon-carbon double bond in the molecule of a water-dispersed type> Production Example 3: 100 parts (amount of isocyanate group: 0.800 mol) of 4,4'-diphenylmethane diisocyanate, 100 parts (amount of NH group: 0.884 mol) of ε-caprolactam, and 200 parts of dioxane were charged into a separable flask equipped with a stirrer, a condenser, and a thermometer. While continuously stirring, the liquid temperature was slowly raised and maintained at 85 °C. After reacting for 120 minutes, dioxane was distilled off to obtain a blocked isocyanate compound. Next, 100 parts of the obtained blocked isocyanate compound and 10.7 parts of EPAN 680 were added to 94.3 parts of ion-exchanged water and dispersed with a wet disperser to obtain the water-dispersed blocked isocyanate of Production Example 3 having a solid content concentration of 54%. The concentration of the regenerated isocyanate group in the water-dispersed blocked isocyanate of Production Example 3 was 8.60%. Production Example 4: 152 parts (amount of isocyanate groups: 1.140 mol) of Millionate MR-200 and 83.4 parts (amount of hydroxyl groups: 0.412 mol) of NEWPOL BPE-40 were charged into a separable flask equipped with a stirrer, a condenser tube, and a thermometer. While continuously stirring, the liquid temperature was slowly raised and maintained at 85°C, and the reaction was carried out for 30 minutes to obtain a polyurethane prepolymer with a concentration of isocyanate groups of 13.0%. Then, 100 parts of dioxane, 50 parts (amount of NH groups: 0.442 mol) of ε-caprolactam, and 0.2 part of triethylamine were added, and the reaction was carried out at 75°C for 120 minutes to obtain a partially blocked prepolymer with a concentration of isocyanate groups of 3.1%. Then, 140 parts (amount of NH 2 groups: 0.285 mol) of a 30% aqueous solution of sodium taurine were added at 40°C, and the reaction was carried out at 40 - 45°C for 30 minutes. Thereafter, dilution with ion-exchanged water and distillation of dioxane were carried out to make the solid content concentration 30%, and the water-dispersed blocked isocyanate of Production Example 4 was obtained. The concentration of regenerated isocyanate groups in the water-dispersed blocked isocyanate of Production Example 4 was 1.70%. Production Example 5: 30 parts (amount of isocyanate groups: 0.168 mol) of DURANATE 24A-100 were charged into a separable flask equipped with a stirrer, a condenser tube, and a thermometer. While continuously stirring, 1 part (amount of NH 2 groups: 0.001 mol) of JEFFAMINE M-1000 was slowly added, and the liquid temperature was raised to 60 - 70°C. When the concentration of isocyanate groups reached 22.6%, 16.1 parts (amount of NH groups: 0.167 mol) of 3,5-dimethylpyrazole were slowly added while maintaining the liquid temperature at 60 - 70°C. When the concentration of isocyanate groups reached zero, 7 parts of butyl glycol ether and 0.72 part of Disponil SUS87 were added and mixed for 5 minutes. Then, 104.59 parts of ion-exchanged water were added, and a dispersion was formed using a high-speed stirrer to obtain the water-dispersed blocked isocyanate of Production Example 5 with a solid content concentration of 30%. The concentration of regenerated isocyanate groups in the water-dispersed blocked isocyanate of Production Example 5 was 4.40%. Production Example 6: 76.00 parts (amount of isocyanate groups: 0.873 mol) of 2,4-toluene diisocyanate, 25.6 parts (amount of hydroxyl groups: 0.572 mol) of trimethylolpropane, and 250 parts of ethyl acetate were charged into a separable flask equipped with a stirrer, a condenser, and a thermometer. While continuously stirring, the liquid temperature was slowly raised and maintained at 40 °C for 2 hours to obtain an isocyanate compound having an isocyanate group concentration of 3.6%. Then, 26.1 parts (amount of hydroxyl groups: 0.300 mol) of methyl ethyl ketoxime were added, and stirring was further continued for 1 hour to obtain a blocked isocyanate compound. 22.14 parts of EPAN680 were added thereto, and 190.7 parts of ion-exchanged water were slowly added. Thereafter, ethyl acetate was distilled off under reduced pressure, and ion-exchanged water was added to make the solid content concentration 44% to obtain the water-dispersed blocked isocyanate of Production Example 6. The concentration of the regenerated isocyanate groups in the water-dispersed blocked isocyanate of Production Example 6 was 3.70%. <Production of Rubber Reinforcing Fiber Treatment Agent and Rubber Reinforcing Fiber> Example 1-1: 11.6 parts of DENACOL EX-313 were added to 588.0 parts of water and dissolved uniformly. Then, 36.3 parts (solid content: 19.6 parts) of the water-dispersed blocked isocyanate of Production Example 3 were added and mixed uniformly. Then, 360.8 parts (solid content: 140.0 parts) of PYRATEX-LB were added and mixed uniformly. Finally, while slowly stirring, 3.33 parts (solid content: 1.0 part) of the water-dispersed blocked isocyanate of Production Example 1 were added and mixed uniformly to obtain a rubber reinforcing fiber treatment agent of Example 1-1 having a solid content concentration of 17.2% (Z in the above formula (1) 1 ). In the rubber reinforcing fiber treatment agent of Example 1-1, the solid content of the blocked isocyanate compound having a structure containing a carbon-carbon double bond in the molecule was 0.71 part relative to 100 parts of the solid content of the rubber latex. Also, in 1 kg of the rubber reinforcing fiber treatment agent of Example 1-1 (solid content concentration: 17.2%), the amount of epoxy groups (X in the above formula (1) 1 ) was 82.27 mmol contained in DENACOL EX-313, and the amount of blocked isocyanate groups (Y in the above formula (1) 1 ) was 75.53 mmol in total, which was the sum of 74.34 mmol contained in the water-dispersed blocked isocyanate of Production Example 3 and 1.19 mmol contained in the water-dispersed blocked isocyanate of Production Example 1. Therefore, in the above formula (1), (X 1 - Y 1 )×20 / Z 1 The value is 7.84 mmol. The rubber reinforcement fiber treatment of Examples 1-1 thus obtained was used directly as a processing fluid, the fibers (polyester cable, HL line, 1670 dtex, double stranded) were impregnated, dried at 130°C for 2 min, followed by heating at 240°C2 The amount of solid component adhesion of the adhesive composition to the fiber was obtained for the fibers for rubber reinforcement of embodiments 1-1 with adhesive compositions attached to the fiber surface for 9.2%. Examples 1-2 to 1-17, Comparative Examples 1-1 to 1-7 Examples 1-2~1-17, Comparative Examples 1-2~1-17, Comparative Examples 1-1~1- are obtained in the same manner as in Examples 1-1, in addition to substituting the raw materials, fibers (polyester cables labeled "PET", nylon cables (1400dtex, double-stranded) labeled "Ny") into the ingredients and amounts contained in Tables 1~4 in the same way as in Examples 1-1 7 Respective fiber treatments for rubber reinforcement as well as fiber treatments for rubber reinforcement The content of capped isocyanate compounds (solid components) having structures containing carbon-carbon double bonds in the molecule relative to the content of rubber latex (solid component) 100 parts (in the table, as “BI / GL amount”), (X) in (1) above 1 -Y 1 )×20 / Z 1 values ​​of (in the table, as “amount of EP-BI”), and the solid component attachment of the adhesive composition to the fiber (attachment rate) are also shown in Tables 1~4. 300.7 parts (116.7 parts of solid composition) of PYRATEX-LB, and 125.0 parts (51.3 parts of solid composition) of Nipol were placed in Reference Example 1 LX-112 was added to 384.7 parts of water and mixed evenly as a latex dilution. On the other hand, 7.0 parts of a concentration of 10% sodium hydroxide aqueous solution were added to 126.5 parts of water and mixed to add 45.0 parts (29.3 parts of solid component) of SUMIKANOL 700S, dissolved uniformly and as the initial condensate solution of resorcinol / formaldehyde Then, with slow stirring, the initial condensate solution of resorcinol / formaldehyde was added to the latex dilution, and 11.1 parts of formalin (concentration 37% aqueous solution) were further mixed to obtain a rubber reinforcement with a solid component concentration of 20.0% The fiber treatment agent was used directly as a processing fluid, and the fiber (nylon cable, 1400dtex, double-stranded jig) was impregnated and treated by drying at 130°C for 2 min, followed by a heating treatment at 240°C for 2 min to obtain the adhesive composition of the rubber reinforcement with an adhesive composition attached to the fiber surface to the fiber with an adhesion rate of 72%. <Preparation and Evaluation of Rubber Products> Combine 70 parts of natural rubber, 30 parts of styrene-butadiene copolymer rubber, 60 parts of carbon black powder, 4 parts of zinc oxide powder, 1.5 parts of stearic acid, 8 parts of aromatic oil, 2.5 parts of sulfur, and vulcanization accelerator (N-cyclohex-2) -benzothiazole hyposulfenamide (N-cyclohexyl-2-benzothiazolylsulfenamide)) 1.1 parts after sufficient mixing to form unsulfurized as flakes Rubber sheets. Seven rubber reinforcing fibers of Example 1-1 are embedded near the surface of the unvulcanized rubber sheets, and sulfurization is performed at 150°C for 30 min at a pressure of 4.7 MPa, thereby obtaining surface attachment of the rubber reinforcing fibers The rubber product of flaky embodiments 1-1 having a rubber composition is also obtained in the same manner for each rubber reinforcement fiber of Examples 1-2~1-17, Comparative Examples 1-1~1-7, and Reference Example 1. Evaluation of Adhesion The required force at this time was determined using a precision universal testing machine (Autograph AG-X, Shimadzu Manufacturing Co., Ltd.) using a flat clamp, leaving the ropes at both ends and fixing 5 ropes at a speed of 300 mm / min relative to the rubber one-sided side. Evaluation of Rubber Adhesion Amount In the above evaluation of adhesion, the surface of the rubber-reinforcing fiber peeled from the rubber sheet was visually observed and evaluated according to the following criteria. The results are shown in Tables 1 to 4. ◎: A large amount of the attached black rubber composition, and there is no part with visible cords. ○: A large amount of the attached black rubber composition, and there is a part with visible cords. △: A small amount of the attached black rubber composition as a whole, and there are many parts with visible cords. ×: No black rubber composition is attached, or almost no attachment. [Table 1] [Table 2] [Table 3] [Table 4] <Production of Rubber-Reinforcing Fiber Treatment Agent Kit and Rubber-Reinforcing Fiber>Example 2-1 13.3 parts of DENACOL EX-614 and 0.7 part of NEOCOL P were added to 973.6 parts of water and dissolved uniformly. Then, 12.4 parts (solid content: 6.7 parts) of the water-dispersible blocked isocyanate of Production Example 3 was added and mixed uniformly to obtain Treatment Agent A with a solid content concentration of 2.07% (Z in the above formula (2) 2 ). On the other hand, 301.3 parts (solid content: 116.9 parts) of PYRATEX-LB and 125.3 parts (solid content: 51.4 parts) of NipolLX-112 were added to 570.1 parts of water and mixed uniformly. Then, while stirring slowly, 3.33 parts (solid content: 1.0 part) of the water-dispersible blocked isocyanate of Production Example 1 was added and mixed uniformly to obtain Treatment Agent B with a solid content concentration of 16.9% (Z in the above formula (2) 3 ). The obtained Treatment Agent A and Treatment Agent B were used as the rubber-reinforcing fiber treatment agent kit of Example 2-1. In Treatment Agent B of the rubber-reinforcing fiber treatment agent kit of Example 2-1, the content of the blocked isocyanate compound having a structure containing a carbon-carbon double bond in the molecule is 0.59 part relative to 100 parts of the content of the rubber latex. Also, in 1 kg of Treatment Agent A (solid content concentration: 2.07%), the amount of epoxy groups (X in the above formula (2) 2 ) is 79.64 mmol contained in DENACOL EX-614, and the amount of blocked isocyanate groups (Y in the above formula (2) 2 ) is 25.39 mmol contained in the water-dispersible blocked isocyanate of Production Example 3. In 1 kg of Treatment Agent B (solid content concentration: 16.9%), the amount of blocked isocyanate groups (Y in the above formula (2) 3) in order to make 1.19 mmol contained in the water-dispersed capped isocyanate of Example 1, and therefore [X in formula (2) above 2 ×2 / Z 2 -(Y 2 ×2 / Z 2 +Y 3 ×20 / Z 3 )] of 51.02 mmol. The treatment agent A of the fiber treatment agent sleeve for rubber reinforcement of Example 2-1 thus obtained was used directly as a processing fluid, the fibers (polyester cable, HL line, 1670dtex, double-stranded jig) were impregnated, dried at 130°C for 2 min, followed by heating at 240°C for 2 min. Then, the treatment agent B of the fiber treatment agent sleeve for rubber reinforcement of Example 2-1 is used directly as a processing fluid, and the fibers treated with the treatment agent A are subjected to impregnation treatment, dry treatment at 130°C for 2 minutes, followed by heating treatment at 240°C for 2 minutes to obtain rubber reinforcement fibers of Example 2-1 with adhesive compositions attached to the fiber surface. The amount of attachment of the adhesive composition to the solid component of the fiber was 6.3%. Examples 2-2 to 2-15, Comparative Examples 2-1, 2-2 In addition to substituting the raw materials used for fiber treatments for rubber reinforcement with the ingredients and amounts contained in Tables 5, 6, the respective sets of fiber treatments for rubber fiber reinforcement, as well as the respective sets of fiber treatments for rubber fiber reinforcement, in the same manner as in Examples 2-1 are obtained. The fibers are all using polyester cables. The content of capping isocyanate compound (solid component) having a structure containing a carbon-carbon double bond in the molecule (in the table, as “BI / GL amount”), [X in the above formula (2), relative to the content of 100 parts of the rubber latex (solid component) in the treatment agent B of the fiber treatment agent set for rubber reinforcement 2 ×2 / Z 2 -(Y 2 ×2 / Z 2 +Y 3 ×20 / Z 3 )] values ​​(in the table, as “amount of EP-BI”), and the solid component attachment of the adhesive composition to the fiber (attachment rate) are also shown in Tables 5 and 6 . 13.3 copies of DENACOL EX-614, and 0.7 copies of NEOCOL are included in Reference Example 2 P was added to 973.6 parts of water and dissolved uniformly. Then, 12.4 parts (6.7 parts of solid component) of the water-dispersed capped isocyanate of Fabrication Example 3 were added and mixed uniformly to obtain a pretreatment with a solid component concentration of 2.07% LX-112 was added to 384.7 parts of water and mixed evenly as a latex dilution. On the other hand, 7.0 parts of a concentration of 10% sodium hydroxide aqueous solution were added to 126.5 parts of water and mixed to add 45.0 parts (29.3 parts of solid component) of SUMIKANOL 700S, dissolved uniformly and as the initial condensate solution of resorcinol / formaldehyde Then, with slow stirring, the initial condensate solution of resorcinol / formaldehyde was added to the latex dilution, and 11.1 parts of formalin (concentration 37% aqueous solution) were further added and mixed evenly to obtain a solid component concentration of 20 0% of the aftertreatment agent.The resulting pretreatment and posttreatment agent was used as a fiber treatment agent sleeve for rubber reinforcement of Reference Example 2. The processing conditions for the polyester cable were implemented in the same manner as in Example 2-1 (replacing treatment agent A with pretreatment agent and replacing treatment agent B with posttreatment agent use) to obtain fibers for rubber reinforcement. Examples 2-16, 2-17, Reference Examples 3, 4 In addition to substituting the raw materials used in the fiber treatments for rubber reinforcement with the ingredients and amounts contained in Table 7 , the fiber treatment agent sets for Examples 2-16, 2-17, References 3, 4 and the fibers for rubber reinforcement using aramid cables (1110dtex, double) were obtained in the same manner as in Example 2-1 or Reference Example 2 strands, labeled “Ara” in the table) 2 ×2 / Z 2 -(Y 2 ×2 / Z 2 +Y 3 ×20 / Z 3 )] values ​​(in the table, as “amount of EP-BI”), and the solid component attachment of the adhesive composition to the fiber (attachment rate) are also shown in Table 7 . <Production and Evaluation of Rubber Products> Using the respective rubber reinforcing fibers obtained, rubber products were produced in the same manner as in Example 1-1, and the adhesion and rubber adhesion amount were evaluated in the same manner as in Example 1-1. The results are shown in Tables 5 to 7. [Table 5] [Table 6] [Table 7] From the results in Tables 1 to 7, by comparing the examples and comparative examples, it can be seen that rubber products containing rubber reinforcing fibers obtained by using the rubber reinforcing fiber treatment agent or the rubber reinforcing fiber treatment agent set of the present invention have excellent adhesion between the rubber reinforcing fibers and the rubber composition, and also have a large rubber adhesion amount, which reflects the interfacial toughness between the rubber reinforcing fibers and the rubber composition. None None

Claims

1. A crosslinking agent composition for use as a crosslinking agent composition for treating rubber reinforcing fibers without resorcinol and formaldehyde, comprising a capped isocyanate compound having a structure containing carbon-carbon double bonds in the molecule and a structure derived from an active hydrogen-containing compound having oxyethylene groups, wherein the aforementioned structure containing carbon-carbon double bonds does not contain an aromatic compound.

2. The crosslinking agent composition as claimed in claim 1, wherein the aforementioned active hydrogen-containing compound having an oxyethylene group is a polyether monohydric alcohol formed by adding ethylene oxide to an alcohol selected from methanol, ethanol, propanol, butanol, hexanol, and octanol.

3. The crosslinking agent composition as claimed in claim 1 or 2, wherein the aforementioned structure containing carbon-carbon double bonds is selected from polybutadiene and polyisoprene structures.

4. A fiber treatment agent for rubber reinforcement, which is free of resorcinol and formaldehyde, and contains rubber latex and a crosslinking agent composition as described in claim 1.

5. The fiber treatment agent for rubber reinforcement as described in claim 4, further comprising an epoxy compound and / or a capped isocyanate compound whose molecule does not contain a carbon-carbon double bond.

6. The fiber treatment agent for rubber reinforcement as described in claim 4 or 5, wherein the content of the end-capped isocyanate compound having a structure containing carbon-carbon double bonds in the aforementioned molecule is 0.5 to 25 parts by mass relative to 100 parts by mass of the aforementioned rubber latex.

7. The rubber reinforcing fiber treatment agent as claimed in claim 5, wherein the amount of epoxy groups and the amount of end-capped isocyanate groups contained in the rubber reinforcing fiber treatment agent (solid component concentration Z1 mass%) satisfy the following formula (1): -30≦(X1-Y1)×20 / Z1≦10 (1) [where, X1: the amount of epoxy groups contained in the treatment agent (1kg) (mmol) Y1: the amount of end-capped isocyanate groups contained in the treatment agent (1kg) (mmol)].

8. A method for manufacturing a rubber reinforcing fiber, comprising the step of: attaching a rubber reinforcing fiber treatment agent as described in claim 4 or 5 to a fiber comprising any one of polyester, nylon and aramid.

9. A rubber reinforcing fiber treatment agent kit, which is a rubber reinforcing fiber treatment agent kit that does not contain resorcinol and formaldehyde, comprising: a treatment agent 1 containing a capped isocyanate compound whose molecule does not have a structure containing carbon-carbon double bonds, and a treatment agent 2 containing rubber latex and a crosslinking agent composition as described in claim 1.

10. The fiber treatment agent kit for rubber reinforcement as described in claim 9, wherein the aforementioned treatment agent 1 further contains an epoxy compound.

11. The fiber treatment agent kit for rubber reinforcement as described in claim 9 or 10, wherein in the aforementioned treatment agent 2, the content of the end-capped isocyanate compound having a structure containing carbon-carbon double bonds in the aforementioned molecule is 0.5 to 20 parts by mass relative to 100 parts by mass of the aforementioned rubber latex.

12. The rubber reinforcing fiber treatment agent kit as claimed in claim 10, wherein the amount of epoxy groups and the amount of end-capped isocyanate groups contained in the aforementioned treatment agent 1 (solid component concentration Z2 mass%) and the aforementioned treatment agent 2 (solid component concentration Z3 mass%) satisfy the following formula (2): 20≦[X2×2 / Z2-(Y2×2 / Z2+Y3×20 / Z3)]≦70 (2) [where, X2: the amount of epoxy groups (mmol) contained in the aforementioned treatment agent 1 (1kg) Y2: the amount of end-capped isocyanate groups (mmol) contained in the aforementioned treatment agent 1 (1kg) Y3: the amount of end-capped isocyanate groups (mmol) contained in the aforementioned treatment agent 2 (1kg).

13. A method for manufacturing a rubber reinforcing fiber, comprising the following steps: using a rubber reinforcing fiber treatment agent kit as described in claim 9 or 10, performing a treatment to attach a processing liquid containing the aforementioned treatment agent 1 to the fiber, followed by a treatment to attach a processing liquid containing the aforementioned treatment agent 2.

14. A method for manufacturing rubber reinforcing fibers as described in claim 13, wherein the aforementioned fibers comprise any one of polyester, nylon, and aramid.

15. A rubber reinforcing fiber treatment agent kit, which is a rubber reinforcing fiber treatment agent kit that does not contain resorcinol and formaldehyde, comprising: a treatment agent 3 containing a crosslinking agent composition as described in claim 1, and a treatment agent 4 containing rubber latex and a capped isocyanate compound whose molecule does not have a structure containing carbon-carbon double bonds.

16. The fiber treatment agent kit for rubber reinforcement as described in claim 15, wherein the aforementioned treatment agent 3 further contains an epoxy compound.

17. A method for manufacturing a rubber reinforcing fiber, comprising the following steps: using a rubber reinforcing fiber treatment agent kit as described in claim 15 or 16, performing a treatment to attach a processing liquid containing the aforementioned treatment agent 3 to the fiber, followed by a treatment to attach a processing liquid containing the aforementioned treatment agent 4.

18. A method for manufacturing rubber reinforcing fibers as described in claim 17, wherein the aforementioned fibers comprise any one of polyester, nylon, and aramid.