JP2014025188A - Reinforcing fiber cord and method for producing same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reinforcing fiber cord having substantially improved fray resistance, and excellent adhesion with a matrix and an anti-fatigue property (durability) and to provide a method for producing the same.SOLUTION: There is provided a reinforcing fiber cord containing, in an inner layer, a compound Ahaving a molecular weight of less than 1000 and a compound Bof less amount than the compound A, wherein the compound Ais an aromatic compound or a compound containing an α-dicarboxylic acid component and the compound Bis an aliphatic compound or an alicyclic compound other than the compound A, and having an adhesion treating agent adhered on the surface. Furthermore, it is preferable that the adhesion treating agent is a resorcin-formalin latex (RFL) adhesive, that the fiber cord is a multifilament fiber having been subjected to twisting or comprises a synthetic fiber, and that the aromatic compound is a heterocyclic compound. Further, it is preferable that the compound Aexists unevenly only in the inner layer of the fiber cord, that a compound having a structure of hexamethylene diisocyanate (HDI) trimer exists in the inner layer of the fiber cord, and that a latex is not present in the inner layer of the fiber cord. In addition, the method for producing a reinforcing fiber cord of the present invention comprises a two-step treatment of the fiber cord with a pretreatment liquid and an adhesive treatment liquid, wherein the pretreatment liquid contains a blocked isocyanate compound Aand a blocked isocyanate compound Bof less amount than this, the block dissociation temperature of the compound Ais lower than the block dissociation temperature of the compound B, and after heat-treating once the fiber cord having the pretreatment liquid adhered thereto, the adhesive treatment liquid is adhered and the fiber cord is subjected to a drying treatment.

Description

  TECHNICAL FIELD The present invention relates to a reinforcing fiber cord, and more particularly to a reinforcing fiber cord having greatly improved hot-skin properties and a method for manufacturing the same.

  In recent years, with respect to issues such as the destruction of the global environment and the depletion of petroleum resources, energy savings and energy substitution, including automobiles and electrical equipment, have attracted considerable attention, especially with the reduction in weight of automobiles to improve fuel efficiency, The need for compactness is growing rapidly. As such members, composite materials reinforced with fibers are widely used.

  However, the composite material containing such reinforcing fibers has a problem that the fibers are loosened at the cut surface once cut after being molded. In particular, this phenomenon is remarkable in fiber reinforced rubber composite materials such as belts, and the rubber constituting the matrix of the composite is easily deformed. There was a problem that it was exposed from the end face and easily frayed.

  One technique for reducing such fraying is to treat the fiber with a solvent-based adhesive. (For example, Patent Document 1 and Patent Document 2). However, such organic solvent-based adhesion treatment has a problem of high load on safety and work environment, and extremely high costs for the adhesion treatment equipment, recovery / waste liquid treatment and its peripheral equipment.

  In view of the above-described problems, a method for producing an adhesion-treated fiber using an aqueous adhesive has been attempted. For example, in Japanese Patent Application Laid-Open No. 2003-221787 (Patent Document 3), the first layer of the fiber cord is treated with an aqueous adhesive composed of an aqueous urethane resin, an epoxy compound, blocked polyisocyanate, and rubber latex, and the second layer is resorcinol. A reinforcing fiber cord treated with a formalin latex (RFL) adhesive has been proposed.

  However, in these water-based technologies, at present, the required level of high adhesiveness, anti-glare property and fatigue resistance required for automobile transmission belts, etc. has not reached the level of solvent systems. It was.

JP-A-9-158989 JP-A-11-81152 JP 2003-221787 A

  The present invention has been made in view of the above-mentioned background problems and technology, and the purpose thereof is a fiber cord for reinforcement, which is greatly improved in hot properties and excellent in adhesion to the matrix and fatigue (durability), and its It is to provide a manufacturing method.

Reinforcing fiber cord of the present invention is a reinforcing fiber cord adhesive treatment agent is adhered to the surface, the inner layer portion of the fiber cord, compounds having a molecular weight of less than 1000 A _1, and small amounts of the compound from the compounds A ₁ B ₁ is included, Compound A ₁ is an aromatic compound or a compound containing an α-dicarboxylic acid component, and Compound B ₁ is an aliphatic compound other than Compound A ₁ or an alicyclic compound.

Furthermore, the adhesive treatment agent is a resorcin / formalin / latex (RFL) adhesive, the fiber cord is a twisted multifilament fiber, or is made of synthetic fiber, aromatic The group compound is preferably a heterocyclic compound. Moreover, and be unevenly distributed inner layer only in compounds A ₁ of fiber cord, the presence of compounds containing hexamethylene diisocyanate (HDI) trimer structure fiber cords inner layer portion, there is a latex in the inner layer portion of the fiber cord Preferably not.

The reinforcing fiber cord manufacturing method of the present invention is a manufacturing method of a reinforcing fiber cord in which the fiber cord is subjected to two-stage treatment with a pretreatment liquid and an adhesive treatment liquid, and the pretreatment liquid is a blocked isocyanate compound. A compound A ₂ and a smaller amount of the blocked isocyanate compound B ₂ , the block dissociation temperature of the compound A ₂ is lower than the block dissociation temperature of the compound B ₂ , and the fiber to which the pretreatment liquid is adhered The cord is once heat-treated, and then an adhesion treatment liquid is attached and dried.

Furthermore, and that the isocyanate group of compound A ₂ is one that was blocked by a compound containing an aromatic compound or an α- dicarboxylic acid component is preferably an aromatic compound is a heterocyclic compound, a compound A ₂ It is preferable to have a hexamethylene diisocyanate (HDI) trimer structure. Further, it is preferable that the isocyanate group of the compound B ₂ is one that was blocked by an aliphatic compound or an alicyclic compound.

  ADVANTAGE OF THE INVENTION According to this invention, the fiber code | cord | chord for reinforcement and the manufacturing method which were excellent in the fray property and excellent in the adhesiveness with a matrix and fatigue property (durability) are provided.

  The reinforcing fiber cord of the present invention has an adhesive treatment agent attached to the surface. Here, as the adhesive treatment agent, one suitable for a structure (matrix) reinforced by fibers is adopted, and there is no particular limitation. More specifically, for example, when the matrix is rubber, the adhesion treatment agent is preferably a resorcin / formalin / latex (RFL) adhesive.

  The fibers constituting the reinforcing fiber cord used in the present invention take a fibrous form in order to reinforce the matrix of the structure, and the fibers are preferably synthetic fibers. More specifically, it is preferably at least one synthetic fiber selected from polyester, polyarylate, aliphatic polyamide, vinylon, wholly aromatic polyamide, polyparabenzobisoxazole, and carbon fiber. Of these, organic fibers are preferable, and polyester fibers are particularly preferable. Furthermore, the fiber constituting the fiber cord is preferably at least one polyester fiber selected from polyethylene terephthalate, polyethylene-2,6-naphthalate, and the like.

  The use of the reinforcing fiber cord of the present invention is preferably used as a core of a rubber fiber composite, particularly a rubber belt, but when used as a belt core, by using the above fiber, It is more optimal in terms of tensile strength, dimensional stability, durability and versatility.

  Here, the reinforcing fiber cord of the present invention is preferably an aggregate of one or a plurality of yarns (sometimes referred to as “fiber cords”), and further, one piece constituting the reinforcing fiber cord. The yarn is an aggregate of a plurality of fiber filaments, and is preferably a bundle. The fineness of the single yarn (fiber cord) is preferably 500 to 4,000 dtex. Such a yarn is particularly preferable in terms of handling properties in twisted yarn, adhesion treatment and molding process, and more preferably 1,000 to 3,000 dtex. The total fineness of the reinforcing fiber cord of the present invention, which is an assembly of such yarns, is preferably 500 to 15,000 dtex. The number of filament filaments, cross-sectional shape, fiber properties, microstructure, polymer properties (molecular weight, terminal functional group concentration, etc.), additives in the polymer, etc. are not particularly limited. The fiber yarn is preferably pretreated with an epoxy resin, a urethane resin or the like in advance during or after the yarn production.

The reinforcing fiber cord used in the present invention is an aggregate composed of one or more of such yarns (fiber cords), and is preferably a cord that is further twisted. Furthermore, it is preferable that the yarn is a fiber cord in which one or a plurality of these yarns are aligned and twisted (bottom twist), and then a plurality of these yarns are aligned and twisted (upper twist). In particular, bending fatigue resistance and the like are improved by twisting. Here, the number of twists in the range satisfying the twisting coefficient K = 300 to 1,200 represented by the following formula (1) maintains the permeability of the adhesive into the fiber cord and exhibits the anti-flaw resistance while exhibiting the anti-fatigue resistance. It is preferable at the point which satisfy | fills, More preferably, it is K = 500-1,000.
K = T × √D (1)
(Where K: twist coefficient, T: number of twists per meter [times / m], D: total fineness [dtex])

When the twist coefficient K is less than 300, the bending fatigue resistance and the adhesion tend to be lowered. On the other hand, when K exceeds 1,200, the strength is lowered and the treatment agent (first Adhesive treatment agent) does not sufficiently permeate, and the anti-glare property tends to decrease.
In addition, as described above, the reinforcing fiber cord of the present invention is twisted by arranging one or a plurality of fiber yarns and then twisting (primary twisting), and then twisting and twisting a plurality of these yarns (upper twisting). When applied, it is preferable to satisfy the twist coefficient K = 300 to 1,200 in both the lower twist and the upper twist, and the twist coefficients of the upper twist and the lower twist may be the same or different. Good.

The reinforcing fiber cord of the present invention is a reinforcing fiber cord having an adhesive treatment agent attached to the surface of such a fiber cord, and the inner layer of the fiber cord has a compound A ₁ having a molecular weight of less than 1000, and comprises a compound a quantity of compound B ₁ less than _1, compound a ₁ is an aromatic compound or a compound containing an α- dicarboxylic acid component, a compound B ₁ is an aliphatic compounds other than compound a ₁ or alicyclic compound There is something.

Here, the compound A ₁ present in the inner layer portion of the fiber cord of the present invention is a compound having a molecular weight of less than 1000, and is an aromatic compound or a compound containing an α-dicarboxylic acid component. These compounds are double bonds. It has a structure that easily resonates due to the presence of. Here, the aromatic compound is not only a general aromatic compound consisting of only carbon atoms, but also a heterocyclic compound in which a nitrogen atom in addition to the carbon atom constitutes a cyclic structure, It is also preferable that it is a formula aromatic compound. Specific examples of compounds particularly preferred as the compound A ₁ include phenols such as phenol, thiophenol, cresol and resorcinol, aromatic secondary amines such as diphenylamine and xylidine, and heterocyclic compounds such as dimethylpyrazole. And α-dicarboxylic acids such as diethylmalonic acid. Among them, dimethylpyrazole which is a heterocyclic aromatic compound is particularly preferable.

As smaller amount than the compounds A ₁ (weight ratio), Compound B ₁ present inside the fiber cords is the above Compound A ₁ other than the compounds, aliphatic compounds having no aromatic or It is an alicyclic compound. These compounds B ₁ are ordinary compounds that do not have a resonance structure like the compound A ₁ , but are less than 1000 in terms of molecular weight, like the compound A ₁ . More specifically, particularly preferable compounds as the compound B ₁ are listed, lactams such as phthalimide, caprolactam and valerolactam, oximes such as methyl ethyl ketone oxime, and aliphatic compounds such as acidic sodium sulfite are particularly preferable. Can be mentioned. Particularly preferably ε- caprolactam is inter alia lactams, more in the case of using dimethyl pyrazole as Compound A _1, when combined with lactams as compounds B _1, excellent impregnation of the agent to internal fibers, The code performance is particularly improved.

The inner layer portion of the reinforcing fiber cord of the present invention contains the compound A ₁ and the compound B ₁ having a molecular weight of less than 1000 as described above. Furthermore, the molecular weight of these compounds is 60 or more and less than 600. It is preferable.
Further, the content of the compound A _{1 in} the fiber cord inner layer portion needs to be larger (weight ratio) than the content of the compound B ₁ , and further, the abundance ratio of the compound A ₁ and the compound B ₁ ( by _weight) a 1 / _{B 1} ratio is preferably in the range of 60/40 95/5.

Here, when the weight ratio of the solid content of compound A ₁ / compound B ₂ is increased, film formation inside the fiber bundle tends to be performed more effectively, and a strong film is formed. When the fiber cord is used for the composite, the anti-glare property tends to be improved. Resonance structure easy to take Compound A ₁ and has a high reactivity, because effective film formation. That is, the specific abundance ratio is preferably 60/40 or more. On the other hand, when the weight ratio of the solid content of compound A ₁ / compound B ₂ is too high, the coating inside the fiber tends to be hard and brittle, and the bending fatigue resistance and durability tend to decrease. . The solid content weight ratio is preferably 95/5 or less. The adhesion amount of the compound A ₁ and the compound B _{1 to} the fiber is preferably in the range of 0.0001 to 0.2% by weight.

In addition to the relatively low molecular weight compound, it is preferable that a polymer compound derived from an epoxy compound coexists in the inner layer portion of the reinforcing fiber cord of the present invention. Furthermore, the total adhesion amount of Compound A ₁ and Compound B ₁ existing in the fiber bundle is 0.01% by weight to 2% with respect to the component amount (weight) attached to other fibers such as a polymer compound. It is preferably in the range of% by weight. A high convergence can be obtained by the presence of a large amount of such a resinous substance as a polymer compound in the inner layer of the fiber bundle. If the abundance of the compounds A ₁ and B ₁ is too high, the adhesiveness to the matrix tends to be reduced, whereas if it is too low, the fiber cords are difficult to converge and the anti-fogging property tends to be lowered.

Here, as the polymer compound present in the inner layer of the fiber bundle of the present invention, an epoxy compound or latex rubber is preferable. The epoxy compound is preferably one in which an epoxy compound having an epoxy group is attached to the fiber surface and made high molecular weight by heat treatment or the like. Specifically, ethylene glycol, glycerol, sorbitol, pentaerythritol, polyethylene glycol, etc. Reaction products of polyhydric alcohols with halogen-containing epoxides such as epichlorohydrin, polyphenols such as resorcin, bis (4-hydroxyphenyl) dimethylmethane, phenol-formaldehyde resin, resorcin-formaldehyde resin and the above-mentioned halogen-containing products Reaction products with epoxides, polyepoxide compounds obtained by oxidizing unsaturated compounds with peracetic acid or hydrogen peroxide, ie 3,4-epoxycyclohexene epoxide, 3,4-epoxycyclohexylme Le-3,4-epoxy cyclohexene carboxylate, bis - such as (3,4-epoxy-6-methylcyclohexyl methyl) Ajibeto can be exemplified. Among these, a reaction product of a polyhydric alcohol and epichlorohydrin, that is, a polyglycidyl ether compound of a polyhydric alcohol is preferable because it exhibits excellent performance. An epoxy compound, it is preferred that as the ratio of the total amount of Compound A ₁ and Compound B ₁ is in the range of 1 / 2-6 / 1.

  Furthermore, the inner layer of the fiber cord preferably contains an isocyanate component so that it can be easily adhered to the surface adhesive layer and the matrix component of the final composite material. In particular, it is preferable to contain an isocyanate component derived from a blocked polyisocyanate compound so that it is difficult to deactivate in the middle of the process.

  Furthermore, in the present invention, the isocyanate component is preferably derived from a compound having a hexamethylene diisocyanate (HDI) trimer structure represented by the following chemical structural formula (I).

  This compound is a compound having, as its basic structure, a trimer structure in which three NCO groups at the ends of hexamethylene diisocyanate (HDI) have a cyclic structure as shown in the chemical structural formula (I). It is also preferable that the structure is a compound that is further polyfunctionalized by condensation as shown in the following chemical structural formula (II), for example. Here, R in the chemical structural formula (II) can be selected within a range that does not impair the affinity and heat resistance with water, such as polyglycol such as polyethylene glycol.

Moreover, as said isocyanate component, it is preferable that three or more NCO functional groups exist in a molecule | numerator, and it becomes possible to improve adhesiveness more.
The other isocyanate component is preferably a component derived from a diphenylmethane diisocyanate (MDI) compound. The component derived from the compound having the hexamethylene diisocyanate (HDI) trimer structure is flexible, whereas the component derived from the diphenylmethane diisocyanate (MDI) compound is rigid and the two components coexist. As a result, a strong, dense and flexible film can be formed on the inner layer portion of the fiber cord, and the bending fatigue resistance and adhesion can be significantly improved along with the fraying property.

As described above, the reinforcing fiber cord of the present invention includes the compound A ₁ and the compound B ₁ in the inner layer portion of the fiber cord, and an adhesive treatment agent is attached to the surface of the fiber cord. Here, the adhesive treatment agent can be appropriately changed depending on the object to be reinforced by the fiber cord, but when the rubber represented by the belt or the like is reinforced by the fiber cord of the present invention, as the adhesive treatment agent, It is preferable to use a resorcin / formalin / latex (RFL) adhesive.

  The RFL adhesive preferably used here will be described. The molar ratio of resorcin to formaldehyde in resorcin / formalin rubber latex (RFL) is preferably in the range of 1: 0.6 to 1: 8. More preferably, it is in the range of 1: 0.8 to 1: 6. If the amount of formaldehyde added is too small, the crosslink density of the resorcin / formalin condensate will decrease and the molecular weight will decrease, and the adhesive layer cohesive force will decrease, resulting in a decrease in adhesion and bending fatigue. If the amount of formaldehyde added is too large, the resorcin / formalin condensate becomes hard due to an increase in cross-linking density, and the compatibility between the RFL and the rubber is inhibited during co-vulcanization with the adherend rubber. Tends to decrease.

  The blending ratio of resorcin / formalin (RF) and latex (L) in the adhesive is a solid content ratio, and RF / L is 1/3 to 1/16, more preferably 1/4 to 1. / 10. If the ratio of rubber latex is too small, the co-vulcanized component with rubber is small and the adhesive force tends to decrease. On the other hand, if the ratio of rubber latex is too large, sufficient strength as an adhesive film cannot be obtained. There is a tendency that the strength and durability tend to decrease, and the adhesiveness of the fiber cord subjected to the adhesion treatment is remarkably increased, and there is a possibility that process passability such as cam-up and handling properties may be lowered in the adhesion treatment process and the molding process.

Furthermore, various latexes such as vinylpyridine / styrene / butadiene (VpSBR) latex, chlorosulfonated polyethylene (CSM) latex, and polybutadiene (PB) latex can be used as the latex constituting the RFL.
In particular, VpSBR latex and / or CSM latex (hereinafter, the total weight of the “VpSBR latex and / or CSM latex” may be referred to as L ₁ ) and PB latex (hereinafter, the “PB latex” is referred to as L consists sometimes referred to as ₂₎ is preferably _L 1 / _{L 2} in a solid content weight ratio is not less 25 / 75-75 / 25.

In particular, it is optimal to use such a latex when the reinforcing fiber cord of the present invention is used for a transmission belt among rubber reinforcements. Usually, high-performance synthetic rubbers with low adhesion such as ethylene-α-olefin-diene rubber, chloroprene rubber, hydrogenated nitrile rubber, chlorosulfonated polyethylene rubber, styrene-butadiene rubber are used for the compression rubber layer of the transmission belt. However, the reinforcing fiber cord of the present invention adopts the composition as described above, so that it has high affinity and co-vulcanizability, as well as a polymer and other agents constituting the fiber cord. It was possible to have a high affinity between them, and at a higher level, it was possible to improve the fraying resistance, bending fatigue resistance and adhesion. Here, as the solid content weight ratio of L ₁ / L ₂ , when L ₁ is too low, the affinity with the polymer constituting the fiber cord and the rubber constituting the transmission belt is lowered, so that the adhesive strength is low. There is a tendency to decrease, and bending fatigue and adhesion tend to decrease. On the other hand, if L ₁ is too large, because the unsaturated bonds of the latex in the adhesive treatment agent is less, the co-vulcanizable decreases bending fatigue strength and adhesion decrease in the rubber constituting the transmission belt Tend to. Furthermore, it is more preferable that the solid content weight ratio of L ₁ / L ₂ is 30/70 to 70/30.

  As the resorcin compound used in the adhesive treatment agent, a pre-oligomerized resorcin-formalin initial condensate or a polynuclear chlorophenol-based resorcin-formalin initial condensate obtained by oligomerizing chlorophenol and resorcin with formalin alone or as necessary May be used in combination.

  Moreover, it is also preferable to use a crosslinking agent in combination with this adhesive treatment agent. Preferred examples of the crosslinking agent to be added include amines, ethylene urea, block polyisocyanate compounds, etc., but blocked polyisocyanate compounds are preferred in view of the stability of the treatment agent over time and the interaction with the pretreatment agent. Can be used.

  The addition rate of a crosslinking agent such as blocked polyisocyanate in this adhesive treatment agent is in the range of 0.5 to 40% by weight, preferably 10 to 30% by weight with respect to resorcin / formalin / rubber latex (RFL). Those are preferred. This is because increasing the amount added usually improves the adhesive strength, but conversely if the amount added is too large, the compatibility of the adhesive with the rubber tends to decrease and the adhesive strength with the rubber tends to decrease.

  Furthermore, it is preferable that the reinforcing fiber cord of the present invention does not contain an organic solvent. By not containing it, in addition to not having an adverse effect on the environment, it was possible to prevent deterioration of performance over time. Such a reinforcing fiber cord can be obtained by using, for example, an aqueous processing solution instead of an organic solvent processing solution.

As described above, the reinforcing fiber cord of the present invention has the adhesive treatment agent attached to the surface of the fiber cord, and the inner layer portion of the fiber cord contains the compound A ₁ and the compound B ₁ . And in reinforcing fiber cord of the present invention, compounds wherein A ₁ in the absence on the surface of the fiber cord, it is preferred to unevenly distributed only in the inner layer portion of the fiber cord. By Compound A ₁ is unevenly distributed only on fiber cords inner layer portion, is improved, which is preferable convergence improves adhesion of the internal fiber cord. Especially this effect when the epoxy compound within the fiber bundle is present is significant, which is believed to be due to the affinity of the epoxy compound and Compound A _1. Further, it is preferable that a compound containing a hexamethylene diisocyanate (HDI) trimer structure is present in the inner portion of the fiber cord, and that no latex is present in the inner portion of the fiber cord. Undesirably inhibit the affinity of the compound A ₁ and epoxy latex is present in the fiber cord inner layer portion. Further, the compound B ₁ is unevenly distributed in the inner portion of the fiber cord, which is preferable because the interaction between the latex and the compound A ₁ is weakened. By adopting such a configuration of the inner layer portion, it becomes possible to appropriately maintain the bonding between the fiber filaments of the inner layer of the fiber cord, and particularly to improve the anti-fogging property.

Such a reinforcing fiber cord of the present invention can be obtained by another method of manufacturing a reinforcing fiber cord according to the present invention. That is, a method for producing a reinforcing fiber cord of two-stage treatment in the pretreatment liquid and an adhesive treatment liquid fiber cords, pretreatment liquid and Compound A ₂ is a blocked isocyanate compound, lesser amounts of it Compound B ₂ which is a blocked isocyanate compound, the block dissociation temperature of compound A ₂ is lower than the block dissociation temperature of compound B ₂ and the fiber cord to which the pretreatment liquid is attached is once heat treated, and then the adhesion treatment liquid is attached. It can be obtained by a drying method.

The fiber constituting the fiber cord used in the production method of the present invention may be a fibrous material for reinforcing the matrix of the structure as described above, and is preferably a synthetic fiber.
Further, as described above, the reinforcing fiber cord of the present invention is preferably an aggregate of one or a plurality of yarns, and this fiber is preliminarily made at the stage of yarn production or after yarn production with epoxy resin, urethane resin. It is also preferable that pretreatment is performed by the above. Further, the cord is preferably a twisted cord, and as described above, the fiber cord is twisted by arranging one or more fiber yarns (primary twisting), and then twisting by twisting a plurality of them. It is preferable to apply (upper twist).

The manufacturing method of the reinforcing fiber cord of the present invention is a method of first treating a pretreatment liquid on such a fiber cord. Here, the pretreatment liquid contains blocked isocyanate compound A ₂ (hereinafter also referred to as compound A ₂ ) and block isocyanate compound B ₂ (hereinafter also referred to as compound B ₂ ) having a block dissociation temperature lower than the block dissociation temperature thereof. a is the content of compound a ₂ are those less than the content of the compound B _2.

  Here, the blocked polyisocyanate compound used in the production method of the present invention is an addition reaction product of a polyisocyanate compound and a blocking agent which is a protecting group for an isocyanate group. A new polyisocyanate compound. More specifically, a polyisocyanate containing a terminal isocyanate group obtained by reacting the isocyanate group (—NCO) and hydroxyl group (—OH) at a molar ratio exceeding 1 exhibits excellent performance. Therefore, it is preferable. Examples of the blocking agent include phenols such as phenol, thiophenol, cresol, and resorcinol, aromatic secondary amines such as diphenylamine and xylidine, heterocyclic compounds such as dimethylpyrazole, and α such as diethylmalonic acid. Dicarboxylic acids, phthalimides, lactams such as caprolactam and valerolactam, aliphatic compounds of acidic sodium sulfite phenols such as phenol, thiophenol, cresol and resorcinol, aromatic secondary amines such as diphenylamine and xylidine And lactams such as phthalimides, caprolactam and valerolactam, oximes such as acetoxime, methyl ethyl ketoxime and cyclohexanone oxime, and acidic sodium sulfite.

Then, both as a blocked polyisocyanate compound used in the manufacturing method, the lower block dissociation temperature blocked polyisocyanate compound A ₂ and the block dissociation temperature higher blocked polyisocyanate compound B ₂ reinforcing fiber cord of the present invention It contains. More preferably, the compound is a block dissociation temperature of the _{A 2} is less than 160 ° C., particularly preferably in a range of 100 to 150 ° C.. The 160 ° C. or higher as a block dissociation temperature of the compounds _{B 2,} particularly preferably in a range of 160 to 200 ° C.. Further, it is preferable abundance of Compound _{A 2} is larger than the present amount of the compound _{B 2,} and it is more preferred solid weight ratio of the compound _{A 2} / Compound _{B 2} is 99 / 1-60 / 40.

Here, the block dissociation temperature is a temperature at which a blocking group is liberated from the blocked isocyanate by heat and expresses isocyanate activity. In the production method of the present invention, the first compound A ₂ is subjected to block dissociation and crosslinking by the first stage low-temperature heat treatment, and then the compound B ₂ is block-dissociated by the second stage high-temperature heat treatment to obtain the isocyanate of the compound A ₂ allowed to crosslink the compound B ₂ to crosslinked. By crosslinking in two stages in this way, it becomes possible to form a strong and dense pretreatment liquid (first bath adhesive) film inside and on the surface of the fiber cord, particularly when used as a core for a transmission belt. In addition, it is possible to improve the flaw resistance, the bending fatigue resistance and the adhesiveness of the fiber cord.

Furthermore the difference in the block dissociation temperature of the compounds A ₂ and the compound B ₂ is it is preferably greater, Compound A ₂ and the block dissociation temperature difference of B ₂ (= block dissociation temperature of the compounds B ₂ - Compound A ₂ block dissociation temperature) is 30 It is preferable that the temperature is not lower than ° C. A sufficient temperature difference made it possible to carry out a two-stage isocyanate crosslinking reaction. When the temperature difference is too small, it becomes a competitive reaction in which the crosslinking reaction of the compound A ₂ and the compound B ₂ occurs at the same time, so that it is difficult to control the crosslinked structure. In addition, the difference in strength of the first bath adhesive film becomes obvious due to the difference in heat distribution between the inner and outer layers of the fiber cord, and the fraying property and the bending fatigue property tend to decrease. More specifically, the block dissociation temperature of the compounds _{A 2} is 110-130 ° C., block dissociation temperature of the compounds _{B 2} is preferably 160 ° C. to 180 ° C..

More specifically, as the compound A ₂ used in the production method of the present invention, the isocyanate group of the compound A ₂ is blocked with an aromatic compound or a compound containing an α-dicarboxylic acid component. Is preferred. The aromatic compound is also preferably a heterocyclic compound containing a nitrogen atom or the like in the cyclic structure in addition to the carbon atom. Particularly, the aromatic compound is a heterocyclic fragrance such as dimethylpyrazole (DMP). A group compound is preferred. The compound containing an α-dicarboxylic acid component is preferably a compound blocked with diethylmalonic acid. Such a compound A ₂ can easily have a resonance structure, and the block body can be dissociated at a lower temperature.

As compound B ₂ to be used in the production method of the present invention, the isocyanate group of the compound B ₂ is preferably one that is blocked by an aliphatic compound or an alicyclic compound. More specifically, it is preferably blocked with an oxime such as methyl ethyl ketone oxime or a lactam such as ε-caprolactam.
Although the block dissociation temperature is to greatly affected by the compound structure to form a block, Compound A ₂ as the block structure dimethylpyrazole (DMP) block structure, a block structure of Compound B ₂ .epsilon.-caprolactam block structure It is particularly preferred that

In the present invention, it is preferable that the blocked polyisocyanate compound A ₂ is made of a compound having a hexamethylene diisocyanate (HDI) trimer structure represented by the following chemical structural formula (I).

  This blocked polyisocyanate compound is a compound having, as its basic structure, a trimer structure in which three NCO groups at the end of hexamethylene diisocyanate (HDI) have a cyclic structure, as in the chemical structural formula (I). However, it is also preferable that each trimer structure is a compound which is further polyfunctionalized by condensation as shown in the following chemical structural formula (II), for example. Here, R in the chemical structural formula (II) can be selected within a range that does not impair the affinity and heat resistance with water, such as polyglycol such as polyethylene glycol.

In the present invention, the blocked isocyanate compound A ₂ preferably has 3 or more functional groups in the molecule after the block is dissociated. When the number of functional groups is 2 or less, crosslinking reactivity in the pretreatment liquid and reactivity with the adhesive treatment liquid tend to be insufficient. In particular, when the reinforcing fiber cord of the present invention is used for reinforcing a rubber such as a belt core material, a resorcin / formalin / latex (RFL) -based adhesive is used as an adhesion treatment liquid, but a small amount derived from resorcinol contained in RFL. Hydroxyl groups tend to lack reactivity.

On the other hand, diphenylmethane diisocyanate (MDI) compounds of particular ε- caprolactam-blocked body as blocked polyisocyanate compound B ₂ is particularly preferred. In the present invention, the epoxy compound and the flexible blocked polyisocyanate compound A ₂ are crosslinked by the first heat treatment, and then the blocked polyisocyanate compound B ₂ having a more rigid MDI structure is crosslinked by the second heat treatment. By forming a coating film of pretreatment liquid that is particularly strong, dense, and flexible on the inside and on the surface of the fiber cord, the fraying resistance, bending fatigue resistance, and adhesiveness that were difficult to achieve with conventional water-based adhesive treatment Improvement can be achieved.

Moreover, in the manufacturing method of the fiber cord for reinforcement of this invention, it is preferable to contain an epoxy compound other than said 2 types of blocked isocyanate compounds as a pre-processing liquid.
Here, the epoxy compound used in the present invention is preferably a compound having at least two epoxy groups in one molecule, and particularly preferably a compound containing 2 g equivalents or more of epoxy groups per 1 kg of the compound. More specifically, reaction products of polyhydric alcohols such as ethylene glycol, glycerol, sorbitol, pentaerythritol, polyethylene glycol and halogen-containing epoxides such as epichlorohydrin, resorcin, bis (4-hydroxyphenyl) dimethylmethane, Reaction products of polyhydric phenols such as phenol / formaldehyde resin and resorcin / formaldehyde resin with the halogen-containing epoxides, polyepoxide compounds obtained by oxidizing unsaturated compounds with peracetic acid or hydrogen peroxide, ie 3, 4-epoxycyclohexylene epoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexenecarboxylate, bis (3,4-epoxy-6-methyl-cyclohexylmethyl) adipate, etc. It can gel. Among these, a reaction product of a polyhydric alcohol and epichlorohydrin, that is, a polyglycidyl ether compound of a polyhydric alcohol is preferable because it exhibits excellent performance.
In addition, the pretreatment agent used in the present invention preferably contains a component such as latex.

In the production method of the present invention, the fiber cord is preferably a fiber cord obtained by twisting the fiber, and the pretreatment liquid penetrates more effectively into the interior by twisting the fiber cord. In addition to the two types of blocked polyisocyanate compounds, the pretreatment liquid preferably contains an epoxy compound. By using an epoxy compound and two types of blocked polyisocyanate compounds in combination, two types of blocked polyisocyanate compounds are used. The effect of the dissociation temperature difference of the isocyanate compound is more exhibited.
Furthermore, when using an epoxy compound together with the pretreatment liquid of the present invention, the epoxy compound / blocked polyisocyanate compound is preferably 5/95 to 30/70 in terms of solid content weight ratio.

  The blocked polyisocyanate compound used in the present invention has a high affinity for the polymer constituting the fiber and has excellent permeability and cohesion, but adhesion to the fiber surface and acceleration of the polyisocyanate crosslinking reaction, and In order to obtain a strong adhesive film, it is preferable to use an epoxy compound in combination. Furthermore, it is preferable to use an epoxy compound / blocked polyisocyanate compound at a solid content weight ratio of 5/95 to 30/70, more preferably 10/90 to 25/75, and particularly 15/85 to 25/75. .

  When an epoxy compound is used in combination, the epoxy compound and the blocked polyisocyanate compound are thermally diffused into the fiber cord over a sufficient amount of time by distilling off water from the attached fibers and performing a heat treatment. By releasing the agent, a crosslinking reaction is caused and a high interface reinforcing ability is obtained. In this thermal diffusion, the epoxy compound and the blocked polyisocyanate compound are preferably reactive low molecular weight components. Therefore, it is preferable that the pretreatment liquid does not contain a hydroxyl group or an alkali component that crosslinks or deactivates the epoxy compound or the blocked polyisocyanate compound with water.

  Here, when the epoxy compound / blocked polyisocyanate compound has an epoxy composition ratio that is too small in the solid content weight ratio, the curing reaction rate of the isocyanate compound tends to decrease, and a strong crosslinked film is obtained. It is easy to reduce the hotness. On the other hand, when the composition ratio of the epoxy compound becomes excessive, the crosslinked film tends to be hard and brittle, and the bending fatigue resistance and durability are likely to be lowered.

  In the present invention, when the epoxy compound and the blocked isocyanate compound are used in combination, the pretreatment liquid (first adhesive treatment agent) is preferably an aqueous dispersion, and when applied to the fiber, the solid content concentration It is desirable to use it as an aqueous dispersion of 2 to 20% by weight, more preferably 5 to 15% by weight.

  In the production method of the present invention, in order to apply the aqueous dispersion as the pretreatment liquid to the fiber, means such as contact with a roller, application by spraying from a nozzle, or immersion in a solution is employed. it can. Moreover, it is preferable that the solid content adhesion amount with respect to the fiber of a pretreatment liquid is the range of 0.5 to 5.0 weight%. If the adhesion amount is too small, the filaments constituting the fiber cord cannot be sufficiently converged and the hotness is lowered. In particular, when the reinforcing fiber cord of the present invention is used for a belt core material, it is difficult to obtain a sufficient and uniform pretreatment liquid film to protect the fiber interface from rubber vulcanization during belt molding or aminolysis during belt use. It is in. On the other hand, when there is too much adhesion amount, gum-up etc. generate | occur | produce in a subsequent adhesion treatment process and a shaping | molding process, and it exists in the tendency for process passability to fall. Therefore, the solid content of the pretreatment liquid on the fibers is preferably 1.0 to 3.0% by weight. In order to control the solid content adhesion amount, it can be performed by means of squeezing with a pressure roller, scraping with a scrubber, etc., blowing off with air blowing, suction, beater, etc. You may let them.

  In the production method of the present invention, heat treatment is performed after applying a pretreatment liquid to the fiber cord. The preferable heat treatment conditions here are preferably two-stage heat treatment. Specifically, for example, it is preferable that drying is performed at a temperature of 80 to 150 ° C. for 60 to 120 seconds, and then heat treatment is performed at a temperature of 180 to 240 ° C. for 60 to 180 seconds.

  First, the moisture on the cord surface and inside the cord is distilled off by the first heat treatment, and the pretreatment liquid containing the blocked polyisocyanate compound is thermally diffused to the inside of the fiber cord. When the treatment conditions are low temperature or short time, the water tends to remain without being distilled off, and the isocyanate compound or the like is deactivated by the high temperature heat treatment, and a strong cross-linked film tends not to be obtained. Conversely, in the case of high-temperature treatment, the crosslinking reaction of the isocyanate compound or the like becomes a competitive reaction with hydrolysis, so that the coating tends to become brittle, and further, the moisture remaining inside the fiber cord is suddenly boiled. There is a tendency that the penetration of the pretreatment liquid (first adhesive treatment agent) into the cord is inhibited. Further, when the heat treatment time is long, the isocyanate compound tends to be oxidized by air and the film performance tends to be lowered. The first stage heat treatment condition is more preferably 90 to 120 ° C. and 60 to 120 seconds.

  Subsequent to this drying heat treatment, it is preferable to perform a second-stage heat treatment at a temperature of 180 to 240 ° C. for 60 to 180 seconds. The crosslinking reaction is carried out in a state where water is sufficiently distilled off from the fiber cord and the blocked polyisocyanate compound and the like are uniformly permeated into the fiber cord. In the case of low temperature or short time treatment, the crosslinking reaction does not proceed sufficiently and the film tends to become brittle. On the contrary, in the case of high temperature or long time treatment, the isocyanate compound or the like is thermally decomposed or air-oxidized, and the performance tends to be difficult to be exhibited. The second stage heat treatment condition is more preferably 200 to 235 ° C. and 60 to 120 seconds.

In the reinforcing fiber cord manufacturing method of the present invention, the pretreatment liquid (first adhesive treatment agent) is adhered to the fiber cord as described above, and the fiber cord to which the pretreatment liquid is adhered is once heat-treated, and then the adhesion treatment liquid. Attaching and drying treatment.
Here, the adhesion treatment liquid is appropriately changed according to the matrix in which the reinforcing fiber cord of the present invention is used. For example, when used for a rubber structure such as a belt, the adhesion treatment liquid (second adhesion treatment agent) is resorcinol. It is preferable to use a formalin latex (RFL) adhesive.
This RFL adhesive has the above-mentioned formulation, and preferably has a molar ratio of resorcin to formaldehyde in the range of 1: 0.6 to 1: 8, and various latexes are used. Is possible.

  Moreover, it is also preferable to use a crosslinking agent in combination with the treatment agent that is the resorcin / formalin / latex (RFL) adhesion treatment agent, and examples thereof include amines, ethylene urea, and block polyisocyanate compounds. A blocked polyisocyanate compound can be preferably used in consideration of stability over time, interaction with a pretreatment agent, and the like. The addition rate of the crosslinking agent is preferably in the range of 0.5 to 40% by weight with respect to the RFL component. This is because increasing the amount added usually improves the adhesive strength, but conversely if the amount added is too large, the compatibility of the adhesive with the rubber tends to decrease and the adhesive strength with the rubber tends to decrease.

  In the present invention, an adhesive liquid (second adhesive treatment agent) is used as a treatment liquid comprising an aqueous dispersion, and the total solid content concentration of the aqueous dispersion is preferably in the range of 5 to 30% by weight. . When the total solid concentration of the treatment liquid is lower than the above range, the adhesive surface tension increases, the uniform adhesion to the fiber surface decreases, and the adhesion amount decreases due to the decrease in the solid adhesion amount. On the contrary, when the total solid content concentration is higher than the above range, the viscosity of the treatment agent becomes high, so that the solid content is too much, and in the adhesion treatment process and the molding process. Process passability such as gum-up tends to decrease.

  Thus, in order to adhere the adhesion treatment liquid (second adhesion treatment agent) to the fibers, means such as contact with a roller, application by spraying from a nozzle, or immersion in a solution can be employed. Moreover, the solid content adhesion amount with respect to the fiber cord is preferably in the range of 1.0 to 10.0% by weight, and more preferably in the range of 1.5 to 8.0% by weight. In order to control the amount of solid matter adhering to the fiber cord, as described above, it can be carried out by means of squeezing with a pressure roller, scraping with a scrubber, etc., blowing off with air blowing, suction, beater means, etc. In order to do so, it may be attached multiple times.

In the production method of the present invention, the adhesion treatment liquid is attached to the fiber cord and dried. As heat treatment conditions for drying, it is preferable to perform two or more stages of drying and heat treatment at a temperature of 100 ° C. to 250 ° C. for 60 to 240 seconds. More preferably, drying is performed at a temperature range of 120 to 180 ° C. for 60 to 180 seconds, and then heat treatment is performed at a temperature of 200 to 245 ° C. for 60 to 180 seconds. If this drying / heat treatment temperature is too low, adhesion to rubber tends to be insufficient, and if the drying / heat treatment temperature is too high, the air oxidation of the adhesive component at high temperature is promoted, resulting in adhesion activity. There is a tendency to decrease.

  In the manufacturing method of the reinforcing fiber cord of the present invention, since the organic solvent-based adhesive treatment prescription of an isocyanate compound having a free isocyanate group is not used as in the conventional solvent treatment, the environment is gentle to the working environment. This is a manufacturing method with less influence. A pretreatment liquid that easily penetrates into the fiber cord is preferably applied as an aqueous adhesive treatment agent, that is, an aqueous dispersion, and the block groups of the two blocked polyisocyanate compounds are sequentially dissociated to suppress deactivation. The fiber surface layer and the fiber inner layer impregnated with the pretreatment liquid (first adhesive treatment agent layer), and further the fiber inner layer (first adhesive treatment agent layer) and adhesive layer By increasing the interfacial adhesive strength with the (second adhesive treatment agent layer), it has become possible to achieve both improvement in anti-glare property and resistance to bending fatigue while ensuring high adhesiveness.

  Hereinafter, the present invention will be described with reference to examples. However, the examples are for illustrative purposes and the present invention is not limited thereto. In addition, evaluation in the Example of this invention was performed with the following measuring method.

(1) Ratio measurement of compound in inner layer of fiber cord (pyrolysis GC-MS)
The adhesive layer of the outermost layer portion was peeled off from the obtained reinforcing fiber cord to obtain a fiber cord in which the fiber was exposed on the surface. Further, the outer 1/4 of the fiber cord was shaved, and a 5 mg measurement sample was taken from the inner layer portion having a diameter of 75% of the original fiber cord diameter.
Using this sample, a pyrolyzer (Nippon Analytical Chemical Industries, Ltd., Curie Point Pyrolyzer “CCP JHP-5”) and a gas chromatograph mass spectrometer (Shimadzu Corporation, “GC-MS QP2010”) compound a ₁ and compound B ₁ compound ratio using cut-and-wait method from the peak area (weight ratio) was determined.
(Measurement condition)
CCP (pyrolysis device)
Oven temperature; 250 ° C., Needle temperature; 250 ° C., sample heating; 590 ° C. × 15 seconds GC (gas chromatograph)
Vaporization chamber temperature: 250 ° C., column: DB-5 ms, split ratio: 1/100,
Column open program: The temperature was increased from 180 ° C. to 320 ° C. at 60 ° C. × 2 minutes at a temperature increase rate of 10 ° C./min.
MS (mass spectrometer)
Ion source temperature: 200 ° C., interface temperature: 250 ° C.
Mass range; 29-600

(2) Block dissociation temperature of blocked polyisocyanate 10 mg of blocked polyisocyanate from which water has been distilled off is nitrogenated using a differential type differential thermal balance apparatus (TG / DTA, manufactured by Rigaku Corporation, “TAS-200”). Under the atmosphere, the sample was heated from room temperature at a heating rate of 10 ° C./min, and the temperature at which the sample was reduced by 10% by weight was determined as the block dissociation temperature.

(3) Tensile strength of the cord, cutting elongation, 150N load elongation (intermediate elongation), 150 ° C. dry heat shrinkage Measured according to JIS L1017 and determined.

(4) Cord hardness It measured according to JISL1096-6.20 using the Gurley type hardness measuring machine (made by a tester industry company).

(5) Peeling adhesive strength of cord This shows the peeling adhesive strength between the adhesion treated fiber cord and rubber. Seven cords were embedded in the surface layer of an unvulcanized sheet of sulfur-based EPDM rubber, and vulcanized by applying a press pressure of 90 kg / cm ² at a temperature of 150 ° C. for 30 minutes. Next, a total of four cords were removed from every other end, and the average of the force required to peel the remaining three cords simultaneously from the rubber sheet at a speed of 200 mm / min (N / 3 cords) was obtained. The peel adhesive strength per book (N / book) was determined.

(6) Bending fatigue resistance and fraying of cords After embedding the adhesive-treated fiber cords in two unvulcanized rubber sheets with a width of 50 mm, a length of 500 mm and a thickness of 2 mm of sulfur-based EPDM rubber at equal intervals Then, vulcanization was performed at a temperature of 150 ° C. for 30 minutes with a pressing pressure of 50 kg / cm ² to obtain a belt-like rubber molded product. Next, a load of 30 kg is applied to the belt-shaped rubber molded product and attached to a roller having a diameter of 20 mm, and a reciprocating motion of 100 rpm is performed at a roller bending (contact) distance of 100 mm under an atmosphere of 100 ° C., and 10,000 times of repeated bending is performed. After the test, the cord was taken out and the remaining strength was measured to determine the strength maintenance rate after bending fatigue. In addition, the belt was cut in the vertical direction of the fiber cord embedded with the belt-shaped rubber molded body after bending fatigue, and the converging state of the fiber cord exposed in the cross section was observed visually and with an optical microscope to evaluate the hotness. . The hotness was evaluated and judged in three stages as follows.
[Shot properties (after bending fatigue test)]
○: The filaments of the fiber cord are bundled, and no abnormal appearance is observed at all.
Δ: Some unfocused spots are found on some filaments of the fiber cord, but good.
X: The fiber cord filaments are not properly focused and are not focused.

[Example 1]
A polyepoxide compound having a sorbitol polyglycidyl ether structure (“Denacol EX-614B” manufactured by Nagase ChemteX Corporation, concentration 100%) 22.8 g, a dialkylsulfosuccinate sodium salt aqueous solution (“Neocol SW-C” No. 8.8 g (manufactured by Ichiko Pharmaceutical Co., Ltd., concentration 70%) was added and stirred, and this was stirred and added to 723.7 g of water and dissolved. Here, the blocked polyisocyanate compound _A is a functional group is 3 or more is dimethyl pyrazole blocked -HDI condensates of trimers as ₂ ( "Trixene 327", British Baxenden Co., block dissociation temperature 115 ° C., concentration 38%) (Table 226.5 g (represented as a in 1) and ε-caprolactam blocked diphenylmethane diisocyanate (“GRILBOND IL-6”, manufactured by EMS, block dissociation temperature 170 ° C., concentration, as blocked polyisocyanate compound B ₂ 50%) (expressed as b in Table 1) 18.2 g was added stirring, epoxy compound / blocked polyisocyanate compound (the sum of the blocked polyisocyanate compound a ₂ and blocked polyisocyanate compound B ₂₎ is solid 20/80 by weight, bro Kud polyisocyanate compound A _{2 /} blocked polyisocyanate compound solid weight ratio of B ₂ pretreatment solution 90/10 (aqueous dispersion of the first adhesive treatment agent, solid concentration 12%) was adjusted.

  Resorcin / formalin (R / F) molar ratio of 1 / 0.6 resorcin-formalin initial condensate (“SUMIKANOL 700S” manufactured by Sumitomo Chemical Co., Ltd., concentration 65%) 19.8 g in 154.5 g water 10% Dissolved in an alkaline aqueous solution containing 5.0 g of caustic soda water and 19.9 g of 20% ammonia water, 138.3 g of vinylpyridine / styrene / butadiene latex (“Pyratex” manufactured by Nippon A & L, concentration 41%), polybutadiene latex ( 206.2 g of “Nippol LX111NF” (manufactured by Nippon Zeon Co., Ltd., concentration 55%) and 363.6 g of water were added. To this solution, 16.8 g of 37% formalin water and 75.9 g of methyl ethyl ketoxime blocked diphenylmethane diisocyanate (“DM6400” manufactured by Meisei Chemical Co., Ltd., concentration 40%) were added and aged at 20 ° C. for 48 hours to a solid content concentration of 22%. The adhesion treatment liquid (RFL type second adhesion treatment agent for the second treatment bath) was prepared.

Using two 1,100 dtex / 192 filament untreated polyethylene terephthalate fibers ("P904B" made by Teijin Fibers), a twisting of 220 times / m in the S direction was performed, and then using these three twisted cords A polyester fiber cord was obtained by top twisting in the Z direction with a twist number of 120 times / m. The fiber cord is fed at a speed of 22 m / min using a computer treater processor (dip code processor manufactured by CA Ritzler), immersed in the pretreatment liquid (first adhesive treatment agent), and then at a constant length. After drying at 120 ° C. for 60 seconds, followed by heat treatment at a constant length of 235 ° C. for 60 seconds, and subsequently dipping in the above-mentioned adhesion treatment liquid (second treatment bath), drying at a constant length of 160 ° C. for 120 seconds, Subsequently, heat treatment was performed at 230 ° C. for 150 seconds under a 3.5% stretch condition to obtain a polyester (polyethylene terephthalate) bonded fiber cord. In this adhesion treated fiber cord, 2.6% by weight of pretreatment liquid (first bath adhesion treatment agent) in terms of solid content with respect to the weight of the polyester fiber cord, adhesion treatment liquid (second bath adhesion treatment agent) Was 4.8% by weight.
When the ratio measurement (pyrolysis GC-MS) of the compound in the inner layer part of the obtained fiber cord was performed, the ratio between the compound A ₁ resulting from dimethylpyrazole (DMP) and the compound B ₁ resulting from ε-caprolactam Was A ₁ / B ₁ = 80/20. The performance evaluation results of the obtained fiber cord are summarized in Table 1.

[Examples 2, 3, 4 and Comparative Example 1]
The solid content weight ratio of blocked polyisocyanate compound A ₂ / blocked polyisocyanate compound B _{2 in} the pretreatment liquid (first adhesive treatment agent) was changed from 90/10 in Example 1 as shown in Table 1. The polyester fiber cord was subjected to adhesion treatment in the same manner as in Example 1 except that the adjustment was performed. Table 1 summarizes the performance evaluation results of the obtained polyester bonded fiber cords.

[Comparative Example 2]
In the pretreatment liquid (first adhesive treatment agent), blocked polyisocyanate compound A ₂ only using, except for not using the blocked polyisocyanate compound B _2, likewise adhesion of the polyester fiber cord as in Example 1 Processed. Table 1 summarizes the performance evaluation results of the obtained polyester bonded fiber cords.

[Examples 5, 6, and 7]
The solid content weight ratio of the epoxy compound / blocked polyisocyanate compound (total amount) in the pretreatment liquid (first adhesive treatment agent) was adjusted as shown in Table 1 from 20/80 in Example 1. Except for the above, the polyester fiber cord was bonded in the same manner as in Example 1. Table 2 summarizes the performance evaluation results of the obtained polyester bonded fiber cords.

[Example 8]
In the pretreatment liquid (first adhesive treatment agent), the blocked polyisocyanate compound A ₂ is replaced with the condensate of dimethylpyrazole block-HDI trimer used in Example 1, and diethyl malonic acid having a functional group of 3 or more A polyester fiber cord was subjected to adhesion treatment in the same manner as in Example 1 except that it was changed to a condensate of HDI trimer (block dissociation temperature 120 ° C., concentration 25%) (indicated as a ′ in Table 1). Table 2 summarizes the performance evaluation results of the obtained polyester bonded fiber cords.

[Example 9]
138.3 g of VpSBR (concentration 41%) in the vinyl pyridine styrene butadiene latex (VpSBR) and polybutadiene latex (PB) of Example 1 in the adhesion treatment liquid (RFL type second adhesion treatment agent for the second treatment bath). Was replaced with 127.5 g of chlorosulfonated polyethylene (CSM) latex (Sepolex CSM, manufactured by Sumitomo Seika Chemical Co., Ltd., concentration 40%) (L1), and the polyester fiber cord was subjected to adhesion treatment in the same manner as in Example 1. . Table 2 summarizes the performance evaluation results of the obtained polyester bonded fiber cords.

  In Examples 1 to 9 of the present invention, the cord hardness was higher than that of the comparative example, the bending fatigue property was excellent, and there was no fraying property after bending fatigue. Moreover, although the Example had a tendency that the cord strength and the cut elongation were lower than the comparative example inferior in converging property, the pretreatment liquid (first adhesive treatment agent) penetrated into the inside of the fiber cord and was strong. This indicates that the film has been formed and the convergence has increased, but the strength retention after bending fatigue is high, and the modulus (intermediate elongation) and dry heat shrinkage, which are important for the belt core, are maintained. This is not a problem.

However, the ratio of the rigid high-temperature dissociated blocked isocyanate compound B ₂ out of the blocked isocyanate compound in the pretreatment liquid as in Example 4 increases, or the epoxy compound in the pretreatment liquid as in Example 7 increases. When the ratio is high, the adhesive film is slightly weakened, and the cord hardness, fraying property and adhesiveness tend to be slightly lowered.
In Comparative Example 1, it was only blocked isocyanate compound bifunctional hot dissociation diisocyanate compound B _2, code hardness than Example, fray resistance, adhesion, with poorer results both bending fatigue strength there were.

  According to the present invention, it is possible to obtain a reinforcing fiber cord which is greatly improved in the fraying property and is excellent in adhesion to rubber, bending fatigue property and durability. In particular, the reinforcing fiber cord of the present invention is suitably used for rubber reinforcement, especially for transmission belt core wires, and is particularly suitable for automobiles that require weight reduction. In the production method of the present invention, water-based adhesion treatment can also be adopted, and as a method for producing an adhesion-treated fiber cord in consideration of the environment, it can be very effective in terms of environmental load and cost reduction.

Claims (13)

A reinforcing fiber cord adhesive treatment agent is adhered to the surface, the inner layer portion of the fiber cord, compounds having a molecular weight of less than 1000 A ₁ and comprises a compound B ₁ of smaller amount than the compounds A _1, compound A ₁ A reinforcing fiber cord, which is an aromatic compound or a compound containing an α-dicarboxylic acid component, and wherein the compound B ₁ is an aliphatic compound other than the compound A ₁ or an alicyclic compound.   The reinforcing fiber cord according to claim 1, wherein the adhesive treatment agent is a resorcin / formalin / latex (RFL) adhesive.   The reinforcing fiber cord according to claim 1 or 2, wherein the fiber cord is a multifilament fiber twisted.   The reinforcing fiber cord according to any one of claims 1 to 3, wherein the fiber cord is made of a synthetic fiber.   The reinforcing fiber cord according to any one of claims 1 to 4, wherein the aromatic compound is a heterocyclic compound. Reinforcing fiber cord of any one of claims 1 to 5, only the inner layer of the fiber cord Compound A ₁ unevenly distributed.   The reinforcing fiber cord according to any one of claims 1 to 6, wherein a compound containing a hexamethylene diisocyanate (HDI) trimer structure is present in an inner layer portion of the fiber cord.   The reinforcing fiber cord according to any one of claims 1 to 7, wherein no latex is present in an inner layer portion of the fiber cord. A method of manufacturing a reinforcing fiber cord of two-stage treatment in the pretreatment liquid and an adhesive treatment liquid fiber cords, pretreatment liquid and Compound A ₂ is a blocked isocyanate compound, a small amount of blocked than comprise a compound B ₂ is an isocyanate compound, compound block dissociation temperature of the a ₂ is lower than the block dissociation temperature of the compounds B _2, after the pretreatment liquid is once heat treated fiber cord attached, adhered to adhesion treatment liquid, dried A method for manufacturing a reinforcing fiber cord, characterized by comprising: Isocyanate group of compound A ₂ is an aromatic compound or a method for producing a reinforcing fiber cord according to claim 9, wherein those that are blocked by compounds containing α- dicarboxylic acid component.   The method for producing a reinforcing fiber cord according to claim 10, wherein the aromatic compound is a heterocyclic compound. Compound A ₂ are provided methods for producing the reinforcing fiber cord of any one of claims 9 to 11 and has a hexamethylene diisocyanate (HDI) trimer structure. Compound isocyanate groups B ₂ is an aliphatic compound or any one method of manufacturing a reinforcing fiber cord as claimed in claim 9 to 12 in which is blocked by an alicyclic compound.