adhesive composition

Abstract

The present invention pertains to: an adhesive composition for organic fiber cord, that has little environmental load as a result of not containing resorcin or formalin and has good adhesiveness; a production method for the adhesive composition for organic fiber cord; and a rubber reinforcing member (organic fiber cord–rubber complex) and tire using these. In addition, the adhesive composition for organic fiber cord is characterized by including a first bath treatment fluid and a second bath treatment fluid. The first bath treatment fluid is a composition including an epoxide and an isocyanate compound. The second bath treatment fluid is a composition including a polyphenol compound (excluding resorcin) and an aldehyde compound having an aromatic ring.

Description

[Technical Field]

[0001] The present invention relates to an adhesive composition for organic fiber cords that is environmentally friendly and therefore does not contain resorcinol or formalin and therefore has good adhesion, a method for producing the adhesive composition for organic fiber cords, and a rubber reinforcing member (organic fiber cord-rubber composite) and a tire that use the adhesive composition or the composition. [Background technology]

[0002] In rubber articles such as tires, belts, air springs, and rubber hoses, organic fibers such as polyester fibers are used in the form of filaments, cords, cables, woven cords, canvas, and the like as reinforcing materials to supplement the strength of the articles.

[0003] When the organic fiber is used as a reinforcing material in the form of an organic fiber cord, the organic fiber cord is first adhered to a rubber coating using an adhesive composition for organic fiber cords to form an organic fiber cord-rubber composite, which is then used as a reinforcing member for rubber articles such as tires.

[0004] Conventionally, RFL (resorcinol, formalin, latex) organic fiber cord adhesives containing resorcinol, formalin, and rubber latex have been used as adhesive compositions for organic fiber cords to ensure adhesive strength through heat curing (see Patent Documents 1 to 3).

[0005] In addition, in order to further improve the adhesive strength, it is known to use a resorcinol-formalin resin obtained by precondensing resorcinol and formalin (see Patent Documents 4 and 5), or to pretreat organic fiber cords made of polyester fibers or the like with an epoxy resin.

[0006] However, although formalin is an important raw material for cross-linking resorcinol, in recent years, there has been a demand to reduce the amount of formalin used in consideration of the working environment, and similarly, there has also been a demand to reduce the amount of resorcinol used in consideration of the environment.

[0007] In this context, adhesive compositions for organic fiber cords that do not contain resorcinol or formalin and are more favorable in terms of both the environment and working environment and adhesiveness, methods for producing such adhesive compositions, and organic fiber cord-rubber composites and tires that use them have been proposed (Patent Documents 6 and 7). However, these have not been put to practical use due to the slow curing of the adhesive, which results in significant adhesion to the drying and curing equipment and low productivity, and furthermore, there is the problem that the adhesive has weak adhesive strength. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 58-2370 [Patent Document 2] Japanese Patent Application Publication No. 60-92371 [Patent Document 3] Japanese Patent Application Publication No. 60-96674 [Patent Document 4] Japanese Patent Application Publication No. 63-249784 [Patent Document 5] Special Publication No. 63-61433 [Patent Document 6] Japanese Patent Publication No. 2010-255153 [Patent Document 7] Patent No. 5990825 Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an adhesive composition for organic fiber cords that does not contain resorcinol or formalin and therefore has a low environmental impact and good adhesion, a method for producing the adhesive composition for organic fiber cords, and a rubber reinforcing member (organic fiber cord-rubber composite) and a tire that use the adhesive composition or the adhesive composition. [Means for solving the problem]

[0010] In order to solve the above problems, the present inventors conducted extensive research into the composition of the adhesive for organic fiber cords. As a result, they discovered an adhesive composition for organic fiber cords that contains a first-bath treatment liquid and a second-bath treatment liquid, where the first-bath treatment liquid is a composition containing an epoxy compound and an isocyanate compound, and the second-bath treatment liquid is a composition containing a polyphenol compound (excluding resorcinol) and an aldehyde compound having an aromatic ring, and that, because the adhesive composition does not contain resorcinol or formalin, it has a low environmental impact and good adhesion, and thus they have completed the present invention.

[0011] That is, the adhesive composition for organic fiber cords of the present invention comprises: [Section 1] An adhesive composition for organic fiber cords, comprising a first bath treatment liquid and a second bath treatment liquid, where: the first bath treatment liquid is a composition containing an epoxy compound and an isocyanate compound, The second bath treatment liquid is a composition containing a polyphenol compound (excluding resorcinol) and an aldehyde compound having an aromatic ring. Adhesive composition for organic fiber cords, is. Such an adhesive composition for organic fiber cords does not contain resorcinol or formalin, and therefore has a low environmental impact and good adhesive properties.

[0012] The adhesive composition for organic fiber cords of the present invention comprises: [Section 2] Item 1. The adhesive composition for organic fiber cords according to Item 1, wherein the second bath treatment liquid further contains latex. It is preferable that: Such an adhesive composition for organic fiber cords provides good bonding between the adhesive layer of the adhesive composition for organic fiber cords and the rubber coating. Latex also has the advantage of being relatively soft and flexible, allowing the adhesive layer to accompany deformation of the organic fiber cord without splitting.

[0013] Furthermore, the adhesive composition for organic fiber cords of the present invention is [Section 3] Item 3. The adhesive composition for organic fiber cords according to Item 1 or 2, wherein the aldehyde compound having an aromatic ring has two or more aldehyde groups in one molecule. It is preferable that: Such an adhesive composition for organic fiber cords has superior adhesive properties.

[0014] Furthermore, the adhesive composition for organic fiber cords of the present invention comprises: [Section 4] 4. The adhesive composition for organic fiber cords according to any one of items 1 to 3, wherein the epoxy compound is selected from the group consisting of diethylene glycol diglycidyl ether, polyethylene diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythrityl polyglycidyl ether, diglycerol polyglycidyl ether, and sorbitol polyglycidyl ether. It is preferable that: Such an adhesive composition for organic fiber cords has superior adhesive properties.

[0015] In addition, the adhesive composition for organic fiber cords of the present invention has [Section 5] 5. The adhesive composition for organic fiber cords according to any one of items 1 to 4, wherein the isocyanate compound is diphenylmethane diisocyanate or polyphenylene polymethylene polyisocyanate. It is preferable that: Such an adhesive composition for organic fiber cords has superior adhesive properties.

[0016] In addition, the adhesive composition for organic fiber cords of the present invention comprises: [Section 6] Item 6. The adhesive composition for an organic fiber cord according to any one of Items 1 to 5, wherein the latex contains at least one selected from natural rubber (NR), polyisoprene rubber (IR), styrene-butadiene copolymer rubber (SBR), polybutadiene rubber (BR), ethylene-propylene-diene rubber (EPDM), chloroprene rubber (CR), halogenated butyl rubber, acrylonitrile-butadiene rubber (NBR), and vinylpyridine-styrene-butadiene copolymer rubber (Vp); It is preferable that: Such an adhesive composition for organic fiber cords provides better bonding between the adhesive layer formed by the adhesive composition for organic fiber cords and the rubber coating. The latex exhibits the advantage of being softer and more flexible, allowing the adhesive layer to accompany deformation of the organic fiber cord without splitting.

[0017] In addition, the adhesive composition for organic fiber cords of the present invention further comprises: [Section 7] 7. The adhesive composition for organic fiber cords according to any one of items 1 to 6, wherein the first bath treatment liquid contains an epoxy compound in a range of more than 5% by mass and not more than 95% by mass, and an isocyanate compound in a range of more than 5% by mass and not more than 95% by mass, as a ratio of solid contents contained in a dried product of the first bath treatment liquid. It is preferable that: Such an adhesive composition for organic fiber cords has superior adhesive properties.

[0018] Furthermore, the adhesive composition for organic fiber cords of the present invention comprises: [Section 8] 8. The adhesive composition for organic fiber cords according to any one of items 1 to 7, wherein the mass ratio of the polyphenol compound (excluding resorcinol) to the aldehyde compound having an aromatic ring in the second-bath treatment liquid, as a ratio of solid contents contained in a dried product of the second-bath treatment liquid, is 0.1 or more and 3 or less. It is preferable that: Such an adhesive composition for organic fiber cords has superior adhesive properties.

[0019] The method for producing the adhesive composition for organic fiber cords of the present invention includes the steps of: [Section 9] A step of preparing the first bath treatment liquid by dissolving an epoxy compound and an isocyanate compound in a solvent; and Item 9. A method for producing an adhesive composition for organic fiber cords according to any one of Items 1 to 8, comprising a step of preparing the second bath treatment solution by adding a basic solution to a solution in which a polyphenol compound (excluding resorcinol) has been dissolved, and then adding an aldehyde compound having an aromatic ring, followed by dissolution and aging; is. The method for producing an adhesive composition for organic fiber cords increases the solubility of polyphenol compounds (excluding resorcinol) and aldehyde compounds having an aromatic ring, thereby enabling stable and efficient production of the adhesive composition for organic fiber cords according to the present invention.

[0020] The organic fiber cord-rubber composite of the present invention comprises: [Section 10] An organic fiber cord-rubber composite using an organic fiber cord treated with the adhesive composition for organic fiber cords according to any one of items 1 to 8. is. Such an organic fiber cord-rubber composite is produced using materials and methods that impart little environmental load, and is excellent in imparting performance such as strength and durability as a reinforcing member for rubber articles such as tires.

[0021] The tire of the present invention is [Section 11] A tire using the organic fiber cord-rubber composite of item 10. is. Such a tire is manufactured using materials and methods that place less strain on the environment, and is excellent in performance such as strength and durability as a tire. [Effects of the Invention]

[0022] According to the present invention, there are provided an adhesive composition for organic fiber cords that does not contain resorcinol or formalin and therefore has a low environmental impact and good adhesion, a method for producing the adhesive composition for organic fiber cords, and a rubber reinforcing member (organic fiber cord-rubber composite) and a tire that use the adhesive composition or the adhesive composition. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a cross-sectional view showing an example of an organic fiber cord (adhesive-coated fiber) treated with the adhesive composition for organic fiber cords of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, embodiments of the present invention will be described in detail. These descriptions are for the purpose of illustrating the present invention and are not intended to limit the present invention in any way.

[0025] <Mass%> In this specification, unless otherwise specified, the mass % representing the content of a component in the first bath treatment liquid or the second bath treatment liquid represents the mass % as a ratio of the solid content contained in the dried product of the first bath treatment liquid or the dried product of the second bath treatment liquid, respectively.

[0026] <Organic fiber cord> The organic fiber cord of the adhesive composition for organic fiber cords according to the present invention is used to supplement the strength of rubber articles such as tires. When using the organic fiber cord as a reinforcing material, organic fibers are first twisted to form an organic fiber cord. The organic fiber cord is then adhered to a rubber coating using the adhesive composition for organic fiber cords to form an organic fiber cord-rubber composite, and this organic fiber cord-rubber composite is used as a reinforcing member for rubber articles such as tires.

[0027] Examples of materials for the organic fiber cord include polyethylene terephthalate (PET) fibers, polyethylene naphthalate fibers, polyamide fibers such as nylon, polyketone fibers, aromatic polyamide fibers, polyparaphenylene benzobisoxazole fibers, rayon fibers, and lyocell fibers. The organic fiber cord can also be used as an assembly of a plurality of single fibers, but the average diameter of the single fibers must be 2 μm or more. Since the fibers constituting the organic fiber cord are intended for use as cord reinforcements for rubber articles such as tires, belts, air springs, and rubber hoses, the average filament diameter of the single fibers is preferably 2 μm or more, and more preferably in the range of 15 μm to 50 μm.

[0028] When the organic fiber cord is intended to be used as, for example, a tire cord, it is preferable that the organic fiber cord be used in the form of an organic fiber cord in which the organic fiber constituting the organic fiber cord is formed by twisting together a plurality of monofilament filaments.

[0029] <First bath processing solution and second bath processing solution> The adhesive composition for organic fiber cords according to the present invention is characterized by comprising a first bath treatment liquid and a second bath treatment liquid.

[0030] Here, the first bath treatment liquid refers to a treatment liquid used to form an adhesive layer on the outer surface in the radial direction of the organic fiber cord in a step prior to treatment with a second bath treatment liquid, which will be described later, in the step of bonding an organic fiber cord to a rubber coating using the adhesive composition for organic fiber cords.

[0031] On the other hand, the second bath treatment liquid refers to a treatment liquid used in a step following treatment with the first bath treatment liquid in the step of bonding an organic fiber cord to a rubber coating using the adhesive composition for organic fiber cords, for forming another adhesive layer on the outer radially outer surface of the organic fiber cord on which an adhesive layer formed by the first bath treatment liquid has been formed.

[0032] In the process of bonding an organic fiber cord to a rubber coating using the adhesive composition for organic fiber cords according to the present invention, the organic fiber cord may be optionally subjected to any treatment at any time including before treating the organic fiber cord with the first bath treatment liquid, after treating with the first bath treatment liquid but before treating with the second bath treatment liquid, or after treating with the second bath treatment liquid. <Composition of first bath treatment solution> The first bath treatment liquid in the adhesive composition for organic fiber cords according to the present invention is a composition containing an epoxy compound and an isocyanate compound.

[0033] <<Epoxy compounds>> The epoxy compound is a compound having at least one epoxy group in one molecule. The epoxy compound acts as a crosslinking agent for the adhesive composition and has excellent adhesive properties, heat resistance, durability, strength, flexibility, electrical insulation, etc.

[0034] The epoxy compound in the present invention is not particularly limited, but is preferably a compound having two or more epoxy groups in one molecule, and more preferably a compound having four or more epoxy groups. When an epoxy compound has two or more epoxy groups in one molecule, the compound effectively functions as a crosslinking agent via the epoxy groups, and when there are four or more epoxy groups, crosslinking occurs more densely and greater flexibility is imparted. Furthermore, although the epoxy compound in the present invention is not particularly limited, it is preferable that one molecule contains 10 or less epoxy groups, because this prevents excessive crosslink density and also provides toughness.

[0035] Specific examples of the epoxy compound include reaction products of epichlorohydrin with polyhydric alcohols such as diethylene glycol diglycidyl ether, polyethylene diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythrityl polyglycidyl ether, diglycerol polyglycidyl ether, and sorbitol polyglycidyl ether. Use of these compounds as the epoxy compound can improve the adhesive properties of the adhesive composition for organic fiber cords.

[0036] The content of the epoxy compound is not particularly limited, but is preferably greater than 5% by mass and less than 95% by mass, more preferably greater than 15% by mass and less than 85% by mass, and even more preferably greater than 15% by mass and less than 50% by mass, as a ratio of the solid content in the first-bath treatment solution and the dried product of the first-bath treatment solution. A content of more than 5% by mass allows for more crosslinking by the epoxy resin in the adhesive layer of the adhesive composition for organic fiber cords, resulting in improved cohesive fracture resistance and adhesive strength at high temperatures and greater flexibility. A content of 95% by mass or less ensures sufficient resin crosslinking in the adhesive layer, providing greater toughness.

[0037] <<Isocyanate compounds>> The isocyanate compound is a compound having at least one isocyanate group as a polar functional group in one molecule. The isocyanate compound has the effect of promoting adhesion of the adhesive composition to a resin material (e.g., an organic fiber material) that is an adherend. In this specification, the term "isocyanate group" refers to a blocked isocyanate group or an isocyanate group, and includes, in addition to an isocyanate group, a blocked isocyanate group formed by reaction with a blocking agent for an isocyanate group, an isocyanate group that has not reacted with a blocking agent for an isocyanate group, or an isocyanate group formed by dissociation of the blocking agent of a blocked isocyanate group.

[0038] The isocyanate compound preferably has a molecular structure in which aromatics are bonded by an alkylene chain, more preferably a molecular structure in which aromatics are bonded by a methylene chain, such as those found in diphenylmethane diisocyanate, polyphenylene polymethylene polyisocyanate, or condensates of phenols and formaldehyde.

[0039] Examples of the isocyanate compound include a compound containing an aromatic polyisocyanate and a thermally dissociable blocking agent, a water-dispersible compound containing a component in which diphenylmethane diisocyanate or an aromatic polyisocyanate is blocked with a thermally dissociable blocking agent, and an aqueous urethane compound.

[0040] Suitable examples of compounds containing aromatic polyisocyanates and thermally dissociable blocking agents include blocked isocyanate compounds containing diphenylmethane diisocyanate and a known isocyanate blocking agent. Examples of water-dispersible compounds containing components in which diphenylmethane diisocyanate or aromatic polyisocyanates are blocked with a thermally dissociable blocking agent include reaction products in which diphenylmethane diisocyanate or polyphenylene polymethylene polyisocyanates are blocked with a known blocking agent that blocks isocyanate groups. Specifically, commercially available blocked polyisocyanate compounds such as Elastron BN69 and Elastron BN77 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and Meikanate TP-10 (manufactured by Meisei Chemical Industry Co., Ltd.) can be used.

[0041] The aqueous urethane compound is obtained by reacting an organic polyisocyanate compound (α) having a molecular structure in which aromatics are bonded by alkylene chains, preferably a molecular structure in which aromatics are bonded by methylene groups, with a compound (β) having multiple active hydrogen groups, and a thermally dissociable blocking agent (γ) for isocyanate groups. Due to its flexible molecular structure, the aqueous urethane compound not only functions as an adhesion improver, but also as a flexible crosslinking agent, preventing the adhesive from fluidizing at high temperatures. The term "aqueous" refers to water-soluble or water-dispersible, and "water-soluble" does not necessarily mean completely water-soluble, but rather means partially water-soluble or does not undergo phase separation in an aqueous solution of the adhesive composition of the present invention.

[0042] Here, the aqueous urethane compound may be, for example, a compound represented by the following general formula (I): [ka] (wherein A represents a residue resulting from the elimination of an active hydrogen group from an organic polyisocyanate compound (α) containing a molecular structure in which aromatics are bonded by alkylene chains; Y represents a residue resulting from the elimination of an active hydrogen group from a thermally dissociable blocking agent (γ) for an isocyanate group; Z represents a residue resulting from the elimination of an active hydrogen group from a compound (δ); X represents a residue resulting from the elimination of an active hydrogen group from a compound (β) having a plurality of active hydrogen groups; n represents an integer of 2 or more and 4 or less; and p+m represents an integer of 2 or more and 4 or less (m≧0.25).)

[0043] Examples of the organic polyisocyanate compound (α) containing a molecular structure in which aromatics are bonded by alkylene chains include methylene diphenyl polyisocyanate and polyphenylene polymethylene polyisocyanate. The compound (β) having a plurality of active hydrogen groups is preferably a compound having 2 to 4 active hydrogen groups and an average molecular weight of 5,000 or less. Examples of such compound (β) include (i) polyhydric alcohols having 2 to 4 hydroxyl groups, (ii) polyhydric amines having 2 to 4 primary and / or secondary amino groups, (iii) amino alcohols having 2 to 4 primary and / or secondary amino groups and hydroxyl groups, (iv) polyester polyols having 2 to 4 hydroxyl groups, (v) polybutadiene polyols having 2 to 4 hydroxyl groups and copolymers thereof with other vinyl monomers, (vi) polychloroprene polyols having 2 to 4 hydroxyl groups and copolymers thereof with other vinyl monomers, and (vii) olefin copolymers having 2 to 4 hydroxyl groups. Examples of polyether polyols having not more than 10 hydroxyl groups include polyhydric amines, polyhydric phenols, and C2-C4 alkylene oxide polyadducts of amino alcohols, C2-C4 alkylene oxide polyadducts of C3 or higher polyhydric alcohols, C2-C4 alkylene oxide copolymers, and C3-C4 alkylene oxide polymers. Furthermore, the thermally dissociable blocking agent (γ) for the isocyanate group is a compound capable of liberating an isocyanate group by heat treatment, and examples thereof include known isocyanate blocking agents. Furthermore, the compound (δ) is a compound having at least one active hydrogen group and an anionic and / or nonionic hydrophilic group. Examples of compounds having at least one active hydrogen group and an anionic hydrophilic group include taurine, N-methyltaurine, N-butyltaurine, aminosulfonic acids such as sulfanilic acid, and aminocarboxylic acids such as glycine and alanine. On the other hand, examples of compounds having at least one active hydrogen group and a nonionic hydrophilic group include compounds having a hydrophilic polyether chain.

[0044] The content of the isocyanate compound is not particularly limited, but is preferably greater than 5% by mass and less than 95% by mass, more preferably greater than 15% by mass and less than 85% by mass, and even more preferably greater than 15% by mass and less than 70% by mass, as a ratio of the solid content in the first-bath treatment solution and the dried product of the first-bath treatment solution. A content of greater than 5% by mass improves the strength and chemical resistance of the adhesive layer formed by the adhesive composition for organic fiber cords, and also improves the adhesion and bonding to the substrate. Furthermore, a content of 95% by mass or less ensures sufficient cohesive fracture resistance of the adhesive layer at high temperatures, and also ensures sufficient adhesive strength at high temperatures.

[0045] <Composition of second bath processing solution> The second bath treatment liquid in the adhesive composition for organic fiber cords according to the present invention is a composition containing a polyphenol compound (excluding resorcinol) and an aldehyde compound having an aromatic ring.

[0046] <<Polyphenol compounds (excluding resorcinol)>> The polyphenol compound (excluding resorcinol) refers to a compound other than resorcinol that has two or more phenolic hydroxyl groups in one molecule. The polyphenol compound (excluding resorcinol) contains a phenolic hydroxyl group, so that the polyphenol compound or a condensate of the polyphenol is soluble in water and uniformly distributed in a water-containing adhesive composition liquid. Furthermore, by not using resorcinol, a relatively inexpensive resin can be formed that has a low environmental impact and excellent mechanical strength, electrical insulation, acid resistance, water resistance, heat resistance, etc.

[0047] The polyphenol compounds (excluding resorcinol) are preferably water-soluble. If the polyphenol compound is water-soluble, the second bath treatment solution for the adhesive composition for organic fiber cords according to the present invention can be prepared by dissolving the polyphenol compound (excluding resorcinol) in an aqueous solvent, with less environmental impact, at more reasonable cost, and in an easier method. Here, the term "water-soluble" does not necessarily mean completely water-soluble, but also means partially water-soluble or does not undergo phase separation in an aqueous solution of the adhesive composition of the present invention.

[0048] Specific examples of the polyphenol compounds (excluding resorcinol) include, but are not limited to, phloroglucinol having the following chemical formula: [ka] Morin (2',4',3,5,7-pentahydroxyflavone) has the following chemical formula: [ka] Examples include novolac-type resorcinol-formaldehyde condensation types and derivatives of these compounds, as well as mixtures of these compounds. The polyphenol compound (excluding resorcinol) is preferably phloroglucinol. These polyphenol compounds have a lower environmental impact than resorcinol and can be used as materials for adhesive compositions for organic fiber cords that have good adhesive properties at reasonable cost.

[0049] The content of the polyphenol compound (excluding resorcinol) is not particularly limited, but from the viewpoint of ensuring better adhesion, it is preferably 3.0% by mass or more, and more preferably 3.5% by mass or more, as a ratio of solids contained in the second-bath treatment solution and in the dried product of the second-bath treatment solution. Furthermore, the content of the polyphenol compound (excluding resorcinol) is not particularly limited, but from the viewpoint of ensuring that the polyphenol compound (excluding resorcinol) dissolves reliably and achieving better workability, it is preferably 13% by mass or less, and more preferably 11% by mass or less, as a ratio of solids contained in the second-bath treatment solution and in the dried product of the second-bath treatment solution.

[0050] <<Aldehyde compounds with aromatic rings>> The aldehyde compound having an aromatic ring is an aromatic aldehyde containing at least one aromatic ring and carrying at least one aldehyde functional group in one molecule. The aldehyde compound having an aromatic ring has a lower environmental impact than formaldehyde. Furthermore, it can form a relatively inexpensive resin that has excellent mechanical strength, electrical insulation, acid resistance, water resistance, heat resistance, etc.

[0051] The aldehyde compound having an aromatic ring in the present invention is preferably an aromatic polyaldehyde compound having two or more aldehyde functional groups in one molecule. When the aromatic polyaldehyde compound has two or more aldehyde groups in one molecule, the compound effectively functions as a crosslinking agent using the aldehyde groups. Furthermore, the aromatic ring is preferably an aromatic ring having an aldehyde functional group, and the aldehyde functional group may be present at the ortho-, meta-, or para-position on the aromatic ring.

[0052] Preferably, the aromatic ring of the aldehyde compound having an aromatic ring is a benzene ring or a furan ring.More preferably, the polyaldehyde is selected from the group consisting of 1,2-benzenedicarbaldehyde, 1,3-benzenedicarbaldehyde, 1,4-benzenedicarbaldehyde, 2-hydroxybenzene-1,3,5-tricarbaldehyde, and mixtures of these compounds.

[0053] Even more preferably, the aldehyde compound having an aromatic ring is 1,4-benzenedicarbaldehyde (also known as terephthalaldehyde) having the following chemical formula: [ka]

[0054] Furthermore, examples of aldehyde compounds having a furan ring include compounds having the following chemical formula: [ka] (wherein X is O; R represents -CHO, methylol).

[0055] These aldehyde compounds having an aromatic ring have a lower environmental impact than formaldehyde and can be used as materials for adhesive compositions for organic fiber cords that have good adhesive properties at reasonable cost.

[0056] The content of the aldehyde compound having an aromatic ring is not particularly limited, but from the viewpoint of ensuring better adhesion, it is preferably 1.0% by mass or more, and more preferably 2.5% by mass or more, in terms of the ratio of solids contained in the second-bath treatment solution and the dried product of the second-bath treatment solution. Furthermore, the content of the aldehyde compound having an aromatic ring is not particularly limited, but from the viewpoint of ensuring the dissolution of the aldehyde compound having an aromatic ring and obtaining better workability, it is preferably 10% by mass or less, and more preferably 9% by mass or less, in terms of the ratio of solids contained in the second-bath treatment solution and the dried product of the second-bath treatment solution.

[0057] In the adhesive composition for organic fiber cords of the present invention, the mass ratio of the polyphenol compound (excluding resorcinol) to the aldehyde compound having an aromatic ring in the second bath treatment solution (the ratio of the solid content contained in the dried product of the second bath treatment solution) is preferably 0.1 or more and 3 or less, and more preferably 0.25 or more and 2 or less. A condensation reaction occurs between a polyphenol compound (excluding resorcinol) and an aldehyde compound having an aromatic ring, and the resulting resin has better hardness and adhesive properties.

[0058] <<Latex>> The adhesive composition for organic fiber cords of the present invention preferably further contains latex in the second bath treatment liquid. The adhesive composition for organic fiber cords of the present invention further contains latex in the second treatment bath, thereby providing good bonding between the adhesive layer of the adhesive composition for organic fiber cords and the rubber substrate. Latex also has the advantage of being relatively soft and flexible, allowing the adhesive layer to accompany deformation of the organic fiber cord without splitting.

[0059] The adhesive composition for organic fiber cords of the present invention preferably further contains latex in the second bath treatment liquid.

[0060] The latex is not particularly limited, and in addition to natural rubber (NR), synthetic rubbers such as polyisoprene rubber (IR), styrene-butadiene copolymer rubber (SBR), polybutadiene rubber (BR), ethylene-propylene-diene rubber (EPDM), chloroprene rubber (CR), halogenated butyl rubber, acrylonitrile-butadiene rubber (NBR), vinylpyridine-styrene-butadiene copolymer rubber (Vp) can be used. These rubber components may be used alone or in a blend of two or more.

[0061] The content of the latex is not particularly limited, but is preferably 40% by mass or more, more preferably 70% by mass or more, in terms of ensuring better adhesion, as a ratio of the solid content contained in the second-bath treatment solution and in the dried product of the second-bath treatment solution. Furthermore, in order to ensure that the relative amounts of resin components and other components other than the latex contained in the adhesive composition for organic fiber cords are at least a certain level, thereby ensuring sufficient cohesive fracture resistance of the adhesive layer, the content is not particularly limited, but is preferably 99% by mass or less, more preferably 95% by mass or less.

[0062] <Method of manufacturing adhesive composition for organic fiber cords> The adhesive composition for organic fiber cords of the present invention is characterized by comprising a first bath treatment liquid and a second bath treatment liquid.

[0063] <<First bath treatment solution preparation process>> The method for producing an adhesive composition for organic fiber cords in the present invention includes a step of preparing the first bath treatment liquid by dissolving an epoxy compound and an isocyanate compound in a solvent.

[0064] The solvent is not particularly limited, and in addition to water, organic solvents such as various alcohols, toluene, xylene, n-hexane, cyclohexane, chloroform, and methyl ethyl ketone can be used. These solvents may be used alone or in combination of two or more. The solvent is preferably water, as this has a low environmental impact.

[0065] The constitutions, contents, etc. of the epoxy compound and isocyanate compound are the same as those explained above in <<Epoxy Compound>> and <<Isocyanate Compound>>, respectively.

[0066] <<Preparation process of the second bath treatment solution>> The method for producing an adhesive composition for organic fiber cords in the present invention includes a step of preparing the second bath treatment liquid by adding a basic solution to a solution in which a polyphenol compound (excluding resorcinol) has been dissolved, and then adding an aldehyde compound having an aromatic ring, followed by dissolution and aging.

[0067] The preparation process of the second bath treatment liquid increases the solubility of the polyphenol compound (excluding resorcinol) and the aldehyde compound having an aromatic ring, thereby enabling the adhesive composition for organic fiber cords of the present invention to be uniformly dispersed without gelation, etc., and thus can be produced stably and efficiently.

[0068] The components of the second bath treatment solution, particularly aldehydes having an aromatic ring, have a problem in that they are poorly soluble in water and disperse in water when simply blended, making them unusable as components of aqueous adhesive compositions. Therefore, in the manufacturing method of the present invention, an aldehyde compound having an aromatic ring is added to a basic solution in which a polyphenol compound (excluding resorcinol) has been dissolved, and then dissolved. The mixing order is not particularly limited as long as (A) a polyphenol compound (excluding resorcinol) is dissolved in a basic solvent, (B) a basic solution is further added as needed, and an aldehyde compound having an aromatic ring is added, and (C) the solutes, the polyphenol compound (excluding resorcinol) and the aldehyde compound having an aromatic ring, are finally dissolved. In the present invention, a preferred mixing order is: (A1) first dissolve the polyphenol compound (excluding resorcinol) in water as a solvent, (A2) add a required amount of base to make a basic solvent and convert the polyphenol compound into a phenolate, thereby maintaining the solubility of the solute, (B1) then, if needed, add additional basic solvent, and then gradually add the aldehyde compound having an aromatic ring, and (C1) dissolve the phenolate ion of the polyphenol compound (excluding resorcinol) and the aldehyde compound having an aromatic ring while causing a chemical reaction change. As a result, according to the method for producing an adhesive composition for organic fiber cords of the present invention, the polyphenol compound (excluding resorcinol) is sufficiently phenolated and dissolved, resulting in a homogeneous state in the adhesive composition liquid for organic fiber cords, and the aldehyde compound having an aromatic ring can be reliably dissolved, thereby improving the productivity of the adhesive composition for organic fiber cords of the present invention, which has excellent adhesive properties.

[0069] The solution in which the polyphenol compound (excluding resorcinol) is dissolved is a solution obtained by dissolving the polyphenol compound (excluding resorcinol) in a predetermined solvent. The composition and content of the polyphenol compound (excluding resorcinol) added to the adhesive composition are the same as those described above in <<Polyphenol Compounds (excluding resorcinol)>>.

[0070] The solvent for dissolving the polyphenol compound (excluding resorcinol) is not particularly limited, but examples thereof include basic solvents such as water and sodium hydroxide solution. From the viewpoint of more reliably dissolving the polyphenol compound (excluding resorcinol), it is preferable for the solvent to contain both water and sodium hydroxide solution. The temperature of the water is preferably 40° C. or higher, and more preferably 60° C. or higher, from the viewpoint of more reliably dissolving the polyphenol compounds (excluding resorcinol).

[0071] The pH of the sodium hydroxide solution is preferably 9 or more and 13 or less, more preferably 10 or more and 12 or less, from the viewpoint of more reliably dissolving the polyphenol compound (excluding resorcinol) and increasing productivity.

[0072] Furthermore, in the method for producing an adhesive composition for organic fiber cords of the present invention, a basic solution is added as needed to the solution containing the polyphenol compound (excluding resorcinol) before adding the aldehyde compound having an aromatic ring. This basic solution may dissolve the aldehyde compound having an aromatic ring, which will be described later, and allow the adhesive composition to be produced.

[0073] The basic solution is preferably aqueous ammonia, since this increases the solubility of the aldehyde compound having an aromatic ring that is subsequently added. The pH of the ammonia water is preferably 9 or more and 13 or less, and more preferably 10 or more and 12 or less, from the viewpoint of more reliably dissolving the aldehyde compound having an aromatic ring and increasing productivity.

[0074] In the method for producing an adhesive composition for organic fiber cords of the present invention, the basic solution is added, and then an aldehyde compound having an aromatic ring is added. The composition and content of the aldehyde compound having an aromatic ring to be added are the same as those explained above in <<Aldehyde compound having an aromatic ring>>.

[0075] Furthermore, from the viewpoint of more reliably dissolving the aldehyde compound having an aromatic ring in the adhesive composition while suppressing a decrease in productivity, it is preferable to gradually add the aldehyde compound having an aromatic ring.

[0076] In the method for producing an adhesive composition for organic fiber cords of the present invention, after the polyphenol compound (excluding resorcinol) and the aldehyde compound having an aromatic ring are mixed in a solvent, the solution is preferably stirred and aged at a desired temperature for a desired time period, because the stirring and aging further enhances the adhesiveness of the adhesive composition for organic fiber cords. The stirring and aging temperature (resin aging temperature) is not particularly limited, but is preferably 20°C or higher, and more preferably 40°C or higher. This is because a temperature of 20°C or higher further enhances the adhesive properties of the adhesive composition for organic fiber cords. The resin aging temperature is also not particularly limited, but is preferably 80°C or lower, and more preferably 60°C or lower. This is because a temperature of 60°C or lower can further suppress an increase in viscosity due to evaporation of the solution. The stirring and aging time (resin aging time) is not particularly limited, but is preferably 30 minutes or more, and more preferably 1 hour or more. This is because 1 hour or more further enhances the adhesiveness of the adhesive composition for organic fiber cords. The resin aging time is also not particularly limited, but is preferably 6 hours or less, and more preferably 4 hours or less. This is because it is estimated that if it is 6 hours or less, all the solutes are dissolved and condensation has progressed.

[0077] In the method for producing an adhesive composition for organic fiber cords of the present invention, after the aldehyde compound having an aromatic ring is added, latex can be further added to the second bath treatment liquid. By adding a latex containing a rubber component, better adhesion can be obtained between the resulting adhesive composition for organic fiber cords and the rubber to be adhered. The composition, content, etc. of the latex are the same as those explained in the above section "Latex".

[0078] Furthermore, in the method for producing an adhesive composition for organic fiber cords of the present invention, when the latex is added, it is more preferable to allow the composition to age after the addition of the latex, because this allows the latex to be more reliably solidified, improving the ease of handling of the adhesive composition and also improving the adhesive properties. Here, the term "aging of latex" refers to a process of adding and mixing latex and then allowing it to stand for a certain period of time in order to improve the properties of the latex. The conditions for this process are not particularly limited. For example, the adhesive composition can be aged by aging it at about 25°C for one hour to several days.

[0079] <Organic fiber cord-rubber composite> The organic fiber cord-rubber composite of the present invention uses an organic fiber cord treated with the adhesive composition for organic fiber cords of the present invention.

[0080] Next, the organic fiber cord-rubber composite of the present invention will be described in detail with reference to the drawings.

[0081] Fig. 1 is a cross-sectional schematic diagram of an example of an organic fiber cord (adhesive-coated fiber) 1 treated with the adhesive composition for organic fiber cords of the present invention. In the adhesive-coated fiber 1 shown in Fig. 1, the surface of an organic fiber cord 2 is coated with an adhesive layer 3 made from a first bath treatment liquid. The outer periphery of the organic fiber cord 2 is further coated with an adhesive layer 4 made from a second bath treatment liquid.

[0082] The organic fiber cord constituting the organic fiber cord-rubber composite of the present invention is as described in <Organic fiber cord>.

[0083] In the organic fiber cord-rubber composite of the present invention, the mass of the adhesive composition for organic fiber cords used is preferably 0.2 mass % or more and 6.0 mass % or less, expressed as the ratio of the solid content contained in the dry product to the mass of the organic fiber cord as an adherend.

[0084] In the present invention, the method for coating the surface of an organic fiber cord with an adhesive layer of an adhesive composition for organic fiber cords is not particularly limited, and examples thereof include a method of immersing the organic fiber cord in the adhesive composition for organic fiber cords, a method of applying the adhesive composition for organic fiber cords to the surface of an organic fiber cord, and a method of spraying the adhesive composition for organic fiber cords onto an organic fiber cord. The adhesive composition for organic fiber cords of the present invention is also characterized by comprising a first-bath treatment liquid and a second-bath treatment liquid. In this method, the outer diameter surface of the organic fiber cord is first coated with the first-bath treatment liquid using one of the coating methods. Then, the outer diameter surface of the organic fiber cord coated with the adhesive layer of the first-bath treatment liquid is coated with the second-bath treatment liquid using one of the coating methods. The method of coating the outer diameter direction surface of an organic fiber cord with an adhesive layer made from a first bath treatment liquid and the method of coating the outer diameter direction surface of an organic fiber cord coated with an adhesive layer made from the first bath treatment liquid with an adhesive layer made from a second bath treatment liquid may be the same or different.

[0085] Furthermore, in the case where the adhesive composition for organic fiber cords used in this coating treatment has a high viscosity, an adhesive liquid containing the adhesive composition for organic fiber cords and a solvent may be used instead of using the adhesive composition for organic fiber cords alone. The adhesive liquid may be a solution in which the components constituting the adhesive composition for organic fiber cords are completely or partially dissolved in a solvent, or a dispersion in which the components constituting the adhesive composition for organic fiber cords are distributed in a solvent.

[0086] The solvent is not particularly limited, and in addition to water, organic solvents such as various alcohols, toluene, xylene, n-hexane, cyclohexane, chloroform, and methyl ethyl ketone can be used. These solvents may be used alone or in combination of two or more. Water is preferably used as the solvent because it has a low environmental impact.

[0087] On the other hand, the rubber constituting the organic fiber cord-rubber composite of the present invention is preferably prepared by blending a rubber component with compounding agents commonly used in the rubber industry. The rubber component is not particularly limited, and examples thereof include natural rubber, conjugated diene-based synthetic rubbers such as polyisoprene rubber (IR), polybutadiene rubber (BR), styrene-butadiene copolymer rubber (SBR), acrylonitrile butadiene rubber (NBR), chloroprene rubber (CR), and butyl rubber (IIR), as well as ethylene-propylene copolymer rubber (EPM), ethylene-propylene-diene copolymer rubber (EPDM), and polysiloxane rubber. Among these, natural rubber and conjugated diene-based synthetic rubber are preferred. These rubber components may be used alone or in combination of two or more.

[0088] The rubber component can be vulcanized using, for example, sulfur, thiralium polysulfide compounds such as tetramethylthiralium disulfide and dipentamethylenethiralium tetrasulfide, 4,4-dithiomorpholine, p-quinone dioxime, p,p'-dibenzoquinone dioxime, cyclic sulfur imide, or peroxide as a vulcanizing agent, and sulfur is preferably used as the vulcanizing agent.

[0089] The rubber component may also be appropriately blended with various additives commonly used in the rubber industry, such as fillers such as carbon black, silica, and aluminum hydroxide, vulcanization accelerators, antioxidants, and softeners. Furthermore, the rubber component may be made into a composite with particles, fibers, cloth, and the like made of various materials.

[0090] <Tires> The tire of the present invention uses the organic fiber cord-rubber composite of the present invention.

[0091] The tire of the present invention includes components such as a carcass ply, a belt layer, a belt reinforcing layer, and a belt-periphery reinforcing layer such as a flipper, and also includes a tire in which the organic fiber cord-rubber composite according to the present invention is used for these components. [Example]

[0092] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples in any way.

[0093] In a two-bath treatment liquid system adhesive composition for organic fiber cords, which contains a first-bath treatment liquid (containing an epoxy compound) and a second-bath treatment liquid (containing a polyphenol compound (excluding resorcinol) and an aldehyde compound having an aromatic ring), but which does not contain resorcinol or formaldehyde in order to reduce the environmental impact, the first-bath treatment liquid was prepared in the following manner: (Comparative Example) or (Example) the first-bath treatment liquid did not contain an isocyanate compound; (Example) the first-bath treatment liquid contained different amounts of epoxy compound (1% by mass and 3% by mass in the first-bath treatment liquid); and (Example) the second-bath treatment liquid was prepared at different resin aging temperatures (25°C and 50°C) and for different resin aging times (0 hours, 2 hours, and 4 hours). Organic fiber cord-rubber composites were produced using these adhesive compositions, and their adhesion properties were measured and compared.

[0094] <Preparation of first bath treatment solution> For comparative examples containing no isocyanate compound, solutions were prepared by diluting Denacol EX614B (Nagase ChemteX Corporation) as an epoxy compound with water to 1% by mass (Comparative Examples 1-4) or 3% by mass (Comparative Examples 5-8). For examples containing an isocyanate compound, solutions were prepared by diluting Denacol EX614B with water to 1% by mass, Elastron BN77 (Dai-ichi Kogyo Seiyaku Co., Ltd.) as an isocyanate compound with 3% by mass, and Isoban (Kuraray Co., Ltd.) with water to 6% by mass (Examples 1-4). The mass percentages given above refer to the mass percentages of the components when blended as liquid or solid in the first-bath treatment solution. The formulations of the above first-bath treatment solutions are summarized in the table below. [Table 1] Mixing ratio in liquid +a % by mass when each component is blended as a liquid or solid in the liquid of the first bath treatment liquid Dry matter solids ratio +b % by mass as the ratio of solid content contained in the dried product of the liquid when the "blending ratio in the liquid" is as shown on the left in the table

[0095] <Preparation of second bath processing solution> In both the comparative examples and the examples, the formulation of the second bath treatment liquid was as follows, with the total mass being 100 (each mass % value is the mass % as the ratio when each component is blended as a liquid or solid in the liquid of the second bath treatment liquid). [Table 2]

[0096] Specific details of the ingredients marked with * in Tables 1 and 2 above are shown in Table 3. [Table 3]

[0097] When the ingredients of each second-bath treatment liquid are blended as shown in Table 2, the mass % of the solid content in the dried product of the second-bath treatment liquid is as shown in Table 4. [Table 4] ++ In Table 4, the ammonia immobilized in the dried material is considered to be the solid content.

[0098] Phloroglucinol (PG) was dissolved in water at 40°C or higher to a concentration of 10% by mass, to which 4% by mass of NaOH, water, and 25% by mass of aqueous ammonia were added in that order, followed by the gradual addition of 1,4-benzenedicarbaldehyde (TA) in small amounts. The addition was carried out at a temperature between 40°C and 60°C, with constant stirring. After stirring until the PG and TA were dissolved, the resin was aged to form a PG / TA resin. To investigate the optimum adhesive properties of an organic fiber cord adhesive composition, the resin aging process, which is a manufacturing process for the organic fiber cord adhesive composition, was carried out at room temperature (ambient temperature) of 25±1°C (Comparative Examples 1, 2, 5, and 6, Examples 1 and 2) or 50°C (Comparative Examples 3, 4, 7, and 8, Examples 3 and 4), with the resin aging time being 0 hours (Comparative Example 1 and 5, Example 1), 2 hours (Comparative Examples 2, 3, 6, and 7, Examples 2 and 3), or 4 hours (Comparative Example 4, 8, Example 4).

[0099] To the PG / TA resin that had been subjected to the specified resin aging, latex (compositions shown in Table 2 above, natural rubber (NR), styrene-butadiene copolymer rubber (SBR), and vinylpyridine-styrene-butadiene copolymer rubber (VP)) was added while stirring at room temperature (ambient temperature) of 27±1°C, and the adhesive composition was then aged at 27±1°C for 24 hours to obtain each second bath treatment solution.

[0100] <Adhesion treatment of organic fiber cords (PET cords for tires) using the first bath treatment solution> After stirring the components in each of the first-bath treatment solutions to uniformly disperse them, an organic fiber cord (PET cord for tires) with a cord fineness of 1670 dtex / 2, a first twist of 39 turns / 10 cm, and a second twist of 39 turns / 10 cm was immersed in each of the first-bath treatment solutions. The solvent in the first-bath treatment solution adhering to the PET cord for tires was then dried, and the cord was subjected to a bonding treatment by heating to obtain a PET cord for tires that had been bonded with the first-bath treatment solution. The drying conditions were a dry temperature of 160°C and a dry time of 80 seconds, and the heating conditions were a hot temperature of 205°C and a hot time of 60 seconds.

[0101] <Adhesion treatment of organic fiber cords (PET cords for tires) using the second bath treatment solution> The tire PET cords that had been subjected to the adhesion treatment using each of the first bath treatment solutions were immersed in each of the second bath treatment solutions, and then the solvent in the second bath treatment solution adhering to the tire PET cords was dried, followed by a heat adhesion treatment to obtain tire PET cords having the structure shown in Figure 1. Here, the drying treatment conditions were a dry temperature of 160°C and a dry time of 80 seconds, and the heat adhesion treatment conditions were a hot temperature of 245°C and a hot time of 60 seconds.

[0102] <Preparation of organic fiber cord-rubber composites and evaluation of adhesive performance> The PET cord for tires, which had been subjected to the first and second bath treatments, was embedded in an unvulcanized rubber composition containing natural rubber, a rubber component made of styrene-butadiene copolymer, carbon black, and a crosslinking agent. This was used as a test piece and subjected to a test at 160°C for 20 minutes at 20 kgf / cm. 2 The obtained vulcanizate was cooled to 23°C, and the cord was excavated from the vulcanizate. The resistance when the cord was peeled from the vulcanizate at a speed of 30 cm / min was measured at room temperature (ambient temperature) of 23±1°C.

[0103] <Adhesion evaluation results> Table 5 shows the results of evaluating the adhesiveness of Comparative Examples 1 to 8 and Examples 1 to 4.

[0104] [Table 5] Contains isocyanate compounds *1 : - means that the first bath treatment liquid does not contain an isocyanate compound; + indicates that the first bath treatment liquid contains an isocyanate compound. Epoxy compound content *2 % by mass as the content of the epoxy compound blended as a liquid or solid in the liquid of the first bath treatment liquid. average adhesion *3 : The average value of the measured adhesiveness values ​​for Comparative Examples 1-4, Comparative Examples 5-8, and Examples 1-4, which have the same epoxy compound content. Index *4 : The average adhesiveness of Comparative Examples 5-8 and Examples 1-4 is relative to the average adhesiveness of Comparative Examples 1-4, which is set to 100.

[0105] In a two-bath treatment liquid system adhesive composition for organic fiber cords containing a first-bath treatment liquid (containing an epoxy compound) and a second-bath treatment liquid (containing a polyphenol compound (excluding resorcinol) and an aldehyde compound having an aromatic ring), which does not contain resorcinol or formaldehyde in order to reduce the environmental impact, in which the first-bath treatment liquid does not contain an isocyanate compound (Comparative Example), organic fiber cord-rubber composites were produced using each adhesive composition for organic fiber cords prepared by changing the epoxy compound content of the first-bath treatment liquid to 1% by mass or 3% by mass, setting the resin aging temperature during preparation of the second-bath treatment liquid to 25°C or 50°C, and setting the resin aging time to 0, 2, or 4 hours, and measuring the adhesion properties thereof. As a result, the adhesion of the organic fiber cord-rubber composites prepared using the adhesive compositions for organic fiber cords of Comparative Examples 1 to 8 was in the range of 19.2 N / cord to 20.0 N / cord, respectively. The average adhesion of the organic fiber cord-rubber composites prepared using the adhesive compositions for organic fiber cords of Comparative Examples 1-4 was 19.3 N / cord (the index for this value was 100), and the average adhesion of the organic fiber cord-rubber composites prepared using the adhesive compositions for organic fiber cords of Comparative Examples 5-8 was 19.8 N / cord (the index was 102). On the other hand, when the first-bath treatment liquid contained an isocyanate compound (Examples), the adhesive compositions for organic fiber cords were prepared with an epoxy compound content of 1 mass %, and the resin aging temperature during preparation of the second-bath treatment liquid was 25°C or 50°C, and the resin aging time was 0, 2, or 4 hours. The adhesive strength of the organic fiber cord-rubber composites produced using these adhesive compositions ranged from 21.2 N / cord to 21.5 N / cord. The average adhesive strength of the organic fiber cord-rubber composites produced using the adhesive compositions of Examples 1-4 was 21.4 N / cord (Index: 111), which was improved over the average adhesive strength of Comparative Examples 1-4 (19.3 N / cord (Index: 100)) and Comparative Examples 5-8 (19.8 N / cord (Index: 102)).

[0106] From the above, the present invention "An adhesive composition for organic fiber cords, comprising a first bath treatment liquid and a second bath treatment liquid, where: the first bath treatment liquid is a composition containing an epoxy compound and an isocyanate compound, The second bath treatment liquid is a composition containing a polyphenol compound (excluding resorcinol) and an aldehyde compound having an aromatic ring. Adhesive composition for organic fiber cords It was confirmed that the adhesive composition for organic fiber cords contains no resorcinol or formalin, which reduces the environmental impact and also provides good adhesive properties. [Industrial Applicability]

[0107] The present invention provides an adhesive composition for organic fiber cords that is environmentally friendly and has good adhesion because it does not contain resorcinol or formalin, a method for producing the adhesive composition for organic fiber cords, and a rubber reinforcing member (organic fiber cord-rubber composite) and tire that use the same. Because the organic fiber cord-rubber composite is used as a reinforcing member for rubber articles such as tires, the present invention can be used in industries that manufacture rubber articles such as tires. [Explanation of symbols]

[0108] 1: Organic fiber cord treated with adhesive composition for organic fiber cord (adhesive-coated fiber) 2: Organic fiber cord 3: Adhesive layer formed by first bath treatment liquid 4: Adhesive layer formed by second bath treatment liquid

Claims

1. A method for producing an organic fiber cord-rubber composite using an organic fiber cord treated with an adhesive composition for organic fiber cords, the method comprising: In the production of the adhesive composition for organic fiber cords, A step of preparing the first bath treatment liquid by dissolving an epoxy compound and an isocyanate compound in a solvent; and a step of preparing the second bath treatment solution, which comprises adding a basic solution to a solution in which a polyphenol compound (excluding resorcinol) has been dissolved, and then adding an aldehyde compound having a benzene ring, followed by dissolution and aging; where: the first bath treatment liquid is a composition containing an epoxy compound and an isocyanate compound, the second bath treatment solution is a composition containing a polyphenol compound (excluding resorcinol) and an aldehyde compound having a benzene ring, the isocyanate compound is diphenylmethane diisocyanate or polyphenylene polymethylene polyisocyanate, the content of the isocyanate compound is in the range of 15% by mass or more and 70% by mass or less, as a ratio of a solid content contained in the first bath treatment solution to a dried product of the first bath treatment solution, The content of the polyphenol compound (excluding resorcinol) in the second bath treatment solution is 3.0% by mass or more and 13% by mass or less, as a ratio of the solid content contained in the dried product of the second bath treatment solution. A method for producing an organic fiber cord-rubber composite using an organic fiber cord treated with an adhesive composition for organic fiber cords.

2. 2. A method for producing an organic fiber cord-rubber composite using an organic fiber cord treated with the adhesive composition for organic fiber cords according to claim 1, wherein the second bath treatment liquid further contains latex.

3. 3. A method for producing an organic fiber cord-rubber composite using an organic fiber cord treated with the adhesive composition for organic fiber cords according to claim 1 or 2, wherein the aldehyde compound having a benzene ring has two or more aldehyde groups in one molecule.

4. 4. A method for producing an organic fiber cord-rubber composite using an organic fiber cord treated with the adhesive composition for organic fiber cord according to claim 1, wherein the epoxy compound is selected from the group consisting of diethylene glycol diglycidyl ether, polyethylene diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythrityl polyglycidyl ether, diglycerol polyglycidyl ether, and sorbitol polyglycidyl ether.

5. 3. A method for producing an organic fiber cord-rubber composite using an organic fiber cord treated with the adhesive composition for organic fiber cord according to claim 2, wherein the latex contains at least one selected from natural rubber (NR), polyisoprene rubber (IR), styrene-butadiene copolymer rubber (SBR), polybutadiene rubber (BR), ethylene-propylene-diene rubber (EPDM), chloroprene rubber (CR), halogenated butyl rubber, acrylonitrile-butadiene rubber (NBR), and vinylpyridine-styrene-butadiene copolymer rubber (Vp).

6. 6. A method for producing an organic fiber cord-rubber composite using an organic fiber cord treated with the adhesive composition for organic fiber cords according to claim 1, wherein the first bath treatment solution contains an epoxy compound in an amount of more than 5 mass % and not more than 95 mass %, as a ratio of the solid content contained in the dried substance of the first bath treatment solution.

7. 7. A method for producing an organic fiber cord-rubber composite using an organic fiber cord treated with the adhesive composition for organic fiber cord according to claim 1, wherein the mass ratio of the polyphenol compound (excluding resorcinol) to the aldehyde compound having a benzene ring, as a ratio of solids contained in the second bath treatment solution and in a dried product of the second bath treatment solution, is 0.1 or more and 3 or less.

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