JP2009203573A - Method for producing polyester fiber cord for reinforcing rubber and rubber hose - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a polyester fiber cord for reinforcing rubber, excellent in adhesiveness to acrylic rubbers and in flexibility, and to provide a rubber hose reinforced with the fiber cords obtained by the production method and having good adhesiveness. <P>SOLUTION: Provided is the method for producing the polyester fiber cord for reinforcing the rubber, characterized by imparting a first treating agent containing an epoxy resin to a polyester fiber twisted cord prepared by melt-spinning a polyester and drawing and twisting the spun fibers and executing thermal treatment, and then imparting a second treating agent containing an acrylate-based latex and executing thermal treatment. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a polyester fiber cord for reinforcing rubber having excellent adhesion to acrylic rubber and flexibility, and a rubber hose having good adhesion reinforced with a fiber cord obtained by the production method.

  Synthetic fibers such as polyamide fibers, polyester fibers, polyvinyl alcohol fibers, and rayon fibers have been commonly used as reinforcing materials for rubber products for various industrial applications such as tire cords, power transmission belts, conveyor belts, and rubber hoses. It has been.

  Among them, polyester fibers represented by polyethylene terephthalate have physical properties such as high strength and modulus, low elongation, low creep and excellent fatigue resistance. It is used as a product, and specific uses of rubber hoses include automobile hoses such as brake hoses, air conditioner hoses, fuel hoses, and oil hoses.

  On the other hand, with the recent increase in the humidity and maintenance-freeness of automobile engine rooms, there has been a demand for further improvements in heat resistance and durability of rubber hoses for automobiles, and the transition to rubber materials with excellent heat resistance is progressing. For example, even in applications where acrylonitrile butadiene rubber (NBR) has been mainly used in the past, studies have been made on using acrylic rubber (ACM) having further excellent heat resistance.

  By the way, when using a fiber as a reinforcing material for rubber products such as a rubber hose for automobiles, it is necessary to firmly bond the fiber and the rubber in order to sufficiently perform the function. In general, when bonding fibers and rubber, a mixture (RFL) of resorcin / formaldehyde initial condensate (RF) and rubber latex (L), which is an adhesive treatment agent, is applied to the fibers, and then dried and baked. After obtaining the treatment cord, a method of vulcanizing and bonding the treatment cord and rubber is used (Patent Documents 1 and 2).

However, it has been difficult to obtain strong adhesion to acrylic rubber with the conventional fiber provided with RFL. As a technique for solving this problem, a prescription for treating polyester fibers using a special chlorophenol compound has been disclosed (Patent Document 3), but it was actually impossible to obtain a practically sufficient adhesive force. .
JP-A-11-350356 (Claims) JP-A-5-148770 (Claims) JP-A-7-304879 (Claims)

  The present invention has been achieved as a result of studying the solution of the problems in the prior art described above as an issue. Accordingly, an object of the present invention is to provide a method for producing a polyester fiber cord for reinforcing rubber having excellent adhesion and flexibility with acrylic rubber, and a rubber hose having good adhesion reinforced with the fiber cord obtained by the production method. It is to provide.

The present invention employs the following means in order to solve such problems. That is,
(1) Heat treatment by applying a first treatment agent containing an epoxy resin to a twisted cord of polyester fiber obtained by melt spinning, drawing and twisting polyester, followed by heat treatment by applying a second treatment agent containing an acrylate latex. A method for producing a polyester fiber cord for rubber reinforcement, characterized by comprising:
(2) The method for producing a polyester fiber cord for rubber reinforcement as described in (1) above, wherein the second treating agent contains a blocked isocyanate compound having a dissociation temperature of 130 ° C to 180 ° C.
(3) The method for producing a polyester fiber cord for rubber reinforcement as described in (2) above, wherein the heat treatment after applying the second treating agent is performed at a temperature lower than the dissociation temperature of the blocked isocyanate compound.
(4) The rubber fiber-reinforced polyester fiber as described in (2) or (3) above, wherein the content of the blocked isocyanate compound in the total solid content of the second treating agent is 20 to 50% by weight Code manufacturing method.
(5) The second treating agent contains 10 to 50% by weight of the epoxy resin in the total solid content of the second treating agent, for rubber reinforcement as described in any one of (1) to (4) above A method for producing a polyester fiber cord.
(6) A rubber hose in which acrylic rubber is reinforced with a polyester fiber cord for rubber reinforcement obtained by the production method according to any one of (1) to (5) above.

  According to the method for producing a polyester fiber cord for rubber reinforcement of the present invention, a flexible reinforced rubber product having excellent adhesion between acrylic rubber and polyester fiber can be efficiently produced, and the obtained reinforced rubber The product demonstrates excellent performance when applied to power transmission belts, conveyor belts, and rubber hoses, especially automobile hoses such as oil hoses and fuel hoses.

  The present invention is described in detail below. The acrylic rubber (ACM) referred to in the present invention is obtained by copolymerizing an arbitrary monomer component described later by any known method such as emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization and the like. As a monomer component of the acrylic rubber, a monomer for introducing a crosslinking group is included, and ethyl acrylate, n-butyl acrylate, ethylene, methyl acrylate, and the like can be arbitrarily used. The acrylic rubber can contain an appropriate type of monomer component in addition to the above monomer components. Examples of such monomer components include carboxyl group-containing compounds such as acrylic acid, methacrylic acid, crotonic acid, 2-pentenoic acid, maleic acid, fumaric acid, and itaconic acid. As the vulcanization method, any method such as sulfur vulcanization, amine crosslinking, and epoxy crosslinking can be selected.

  The polyester fiber used in the present invention is a multifilament made of a polyester composed of dicarboxylic acid and glycol having ethylene terephthalate as the main repeating unit, and more than 90 mol% of the dicarboxylic acid component is composed of terephthalic acid, and the glycol component Polyethylene terephthalate in which 90 mol% or more of ethylene glycol consists of is preferable. Further, polyethylene terephthalate that does not copolymerize an isophthalic acid component or the like and polyethylene terephthalate that does not substantially contain additives such as inorganic particles are preferable. Furthermore, in order to ensure the strength of the polyester fiber and the deterioration characteristics in the rubber, those having an intrinsic viscosity of 0.80 or more and a carboxyl group terminal amount of 20 equivalent / ton or less, and further 18 equivalent / ton or less. In view of excellent heat resistance and hydrolysis resistance, it is preferable. The upper limit of the intrinsic viscosity is not particularly limited as long as melt spinning is possible, but is usually preferably 1.2 or less. The spinning method of the polyester fiber may be a method in which spinning and drawing are performed in two steps, or a method in which both steps are performed in one step.

  In order to improve the adhesiveness of the polyester fiber, an epoxy compound, a blocked isocyanate compound, an amine compound, or the like may be imparted in the spinning process.

  The polyester fiber used in the present invention includes not only filament yarns made from the above fibers but also cords, woven fabrics, woven fabrics, and the like made from the filament yarns, and improves the convergence of the fibers. Therefore, it is preferable to apply twist. What is necessary is just to give the process by the adhesion processing agent mentioned later to the fiber of the arbitrary forms.

  In the polyester fiber cord manufacturing method of the present invention, a polyester fiber twisted cord is provided with a first treatment agent containing an epoxy resin and heat-treated, and subsequently a second treatment agent containing an acrylate latex is applied and heat-treated. is required.

  The epoxy resin that can be used in the present invention has two or more epoxy groups in one molecule.

  The compound having two or more epoxy groups in the molecule includes, for example, a glycidyl ether type epoxy resin obtained from a compound having a hydroxyl group in the molecule, a glycidyl amine type epoxy resin obtained from a compound having an amino group in the molecule, A glycidyl ester type epoxy resin obtained from a compound having a carboxyl group, a cyclic aliphatic epoxy resin obtained from a compound having an unsaturated bond in the molecule, a heterocyclic epoxy resin such as triglycidyl isocyanate, or the like. An epoxy resin in which two or more types are mixed in the molecule.

  Specific examples of glycidyl ether type epoxy resins include bisphenol A type epoxy resins obtained by reaction of bisphenol A and halogen-containing epoxides such as epichlorohydrin, and bisphenol F obtained by reaction of halogen-containing epoxides. Bisphenol F-type epoxy resin, biphenyl-type epoxy resin obtained by reaction of biphenyl with the halogen-containing epoxide, resorcinol-type epoxy resin obtained by reaction of resorcinol with the halogen-containing epoxide, bisphenol S and the halogen-containing epoxide Bisphenol S-type epoxy resin obtained by reaction with polyhydric acid, polyethylene glycol type epoxy resin which is a reaction product of polyhydric alcohols and the above halogen-containing epoxides, Epoxy resins obtained by oxidizing unsaturated bonds such as pyrene glycol type epoxy resin, bis- (3,4-epoxy-6-methyl-dicyclohexylmethyl) adipate, 3,4-epoxycyclohexene epoxide, and other naphthalene type epoxies Resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, and their halogen or alkyl-substituted products can be used.

  The first treating agent of the present invention contains at least one component selected from the group consisting of a chloro-modified resorcin, a blocked isocyanate compound, and a rubber latex in addition to an epoxy compound from the viewpoint of improving adhesiveness. As a result, the effect can be further improved.

  The chloro-modified resorcin that can be used in the present invention is a compound obtained by condensing parachlorophenol with formalin and resorcin, and is a phenol compound represented by the following general formula.

In the formula, W represents CH ₂ or Sn, X and Y represent groups selected from Cl, Br, I, H, OH and C _{1 to} C ₆ alkyl groups, and n represents 1 to 10 It is an integer. The phenol compound represented by the general formula is an initial condensate of a halogenated phenol compound and formaldehyde, an initial condensate of sulfur-modified resorcinol and formaldehyde, or an initial condensate of sulfur halide-modified resorcin and formaldehyde.

  The method for preparing these chloro-modified resorcins is not particularly limited, and examples thereof include parachlorophenol, orthochlorophenol, parabromophenol, paraiodophenol, orthocresol, paracresol, para-tertiary butylphenol and 2,5-dimethylphenol. Of these, parachlorophenol, parabromophenol, paracresol, and paratertiary butylphenol are used, and parachlorophenol is particularly preferably used.

  By condensing such a starting material with formaldehyde in the presence of an alkali catalyst, or by reacting a condensate obtained by previously reacting the starting material in the presence of an acid catalyst with formaldehyde in the presence of an alkali catalyst. A phenolic compound can be obtained.

  Specific examples of the chloro-modified resorcinol include 2,6-bis (2 ′, 4′-dihydroxy-phenylmethyl) -4-chlorophenol (“Kasabond” manufactured by Thomas One Co., Ltd., “Nagase Kasei Kogyo Co., Ltd.” Among them, those mainly composed of a chlorophenol compound having 3 or more benzene nuclei are preferably used from the viewpoint of adhesion and processability.

  The blocked isocyanate compound that can be used in the present invention is an addition compound of a polyisocyanate compound and a blocking agent, and the blocking agent component is liberated by heating to produce an active polyisocyanate compound. is there. Examples of the polyisocyanate compound include polyisocyanates such as tolylene diisocyanate, metaphenylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, polymethylene polyphenyl isocyanate, triphenylmethane triisocyanate, or two or more of these polyisocyanates and active hydrogen atoms. Terminal isocyanate group-containing polyol adduct polyisocyanate obtained by reacting a compound having, for example, trimethylolpropane, pentaerythritol, etc. with a molar ratio of isocyanate group (—NCO) to hydroxyl group (—OH) exceeding 1. Is mentioned. In particular, aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate and polymethylene polyphenyl isocyanate are preferable because they exhibit excellent performance.

  Examples of blocking agents include phenols such as phenol, thiophenol, cresol, and resorcin, aromatic secondary amines such as diphenylamine and xylidine, phthalimides, lactams such as caprolactam and valerolactam, acetoxime, and methyl ethyl ketone. Examples include oximes such as oxime and cyclohexanone oxime, and acidic sodium sulfite.

  Such blocked isocyanate compounds are usually used as emulsions, dispersions or aqueous solutions. In order to obtain an emulsified liquid or a dispersion liquid, for example, such a blocked polyisocyanate is dissolved as it is or in a small amount of a solvent as necessary, and then a known emulsifier such as sodium alkylbenzenesulfonate, dioctylsulfosuccinate sodium salt, nonylphenol. What is necessary is just to emulsify or disperse | distribute using an ethylene oxide adduct etc.

  Further, the rubber latex that can be used in the present invention is, for example, natural rubber latex, butadiene rubber latex, styrene / butadiene rubber latex, vinylpyridine / styrene / butadiene rubber latex, nitrile rubber latex, hydrogenated nitrile rubber latex, chloroprene rubber latex. Chlorosulfonated rubber latex, ethylene / propylene / diene rubber latex, acrylate latex and the like, and these can be used alone or in combination. Among them, it is preferable to use acrylate latex alone or in combination with another. The acrylate latex is an emulsion obtained by emulsifying an acrylic ester with a surfactant.

  The first treatment agent used in the present invention must contain an epoxy resin, but when mixing other components, the total solid content of the first treatment agent is mixed with 20 to 100% by weight of the epoxy resin. Preferably, it is 40 to 100% by weight. If it is out of this range, the adhesiveness may decrease.

  The second treating agent used in the present invention must contain an acrylate latex, but preferably contains a blocked isocyanate compound having a dissociation temperature of 130 ° C. to 180 ° C. from the viewpoint of improving adhesiveness. More preferably, a blocked isocyanate having a dissociation temperature of 140 ° C. to 180 ° C. is preferable. When the dissociation temperature is lower than 130 ° C, the adhesiveness may be deteriorated. When the dissociation temperature is higher than 180 ° C, the fiber cord becomes hard and flexibility may be insufficient. As the blocked isocyanate compound, the above-mentioned compounds can be used.

  The blocked isocyanate compound is preferably mixed in an amount of 20 to 50% by weight relative to the total solid content of the second treatment agent, more preferably 25 to 40% by weight. If it is out of this range, the adhesiveness may decrease.

  Moreover, it is preferable that the 2nd processing agent used by this invention contains the epoxy resin from a viewpoint of adhesive improvement. The epoxy resin is preferably mixed in an amount of 10 to 50% by weight relative to the total solid content of the second treatment agent, and more preferably 20 to 40% by weight. If it is out of this range, the adhesiveness may decrease.

  Furthermore, the second treating agent used in the present invention preferably contains a resorcin / formaldehyde initial condensate from the viewpoint of improving adhesiveness. The resorcin / formaldehyde is particularly preferably prepared using a resorcin / formaldehyde initial condensate obtained by initial condensation in the presence of an alkali catalyst. For example, it is prepared by a method in which resorcin and formaldehyde are added and mixed in an alkaline aqueous solution containing an alkaline compound such as sodium hydroxide and allowed to stand at room temperature for several hours, so that resorcin and formaldehyde are initially condensed.

  As the resorcin / formaldehyde initial condensate, a resorcin / formaldehyde molar ratio of 1: 0.3 to 1: 5, preferably 1: 0.75 to 1: 2.0 is used. If the molar ratio of formaldehyde is less than the above range, the treatment cord may become sticky and may cause the processing machine to become dirty.On the other hand, if the molar ratio of formaldehyde is above this range, the adhesion will be insufficient. May be.

  Although the mechanism by which the adhesiveness between the polyester fiber and the acrylic rubber is improved by the present invention is not clear, the epoxy resin contained in the first treatment agent increases the functional group on the surface of the polyester fiber, thereby increasing the adhesion rubber. It is presumed that the acrylate latex contained in the second treating agent has a high affinity with the adherend rubber and has the effect of obtaining a flexible cord. Furthermore, by mixing blocked isocyanate with the second treating agent, it is presumed that the reactivity with both the polyester fiber and acrylic rubber is increased, and strong adhesiveness is expressed.

  Next, the processing method of the polyester fiber cord for rubber reinforcement of the present invention will be described. The polyester fiber cord for reinforcing rubber of the present invention is obtained by applying a heat treatment by applying a first treatment agent containing an epoxy resin, and applying a heat treatment by applying a second treatment agent containing an acrylate latex.

  In the method of applying the first treatment agent containing an epoxy resin, the polyester fiber raw cord or the raw cord bran is immersed in a dip solution prepared by treating the treatment agent containing the component as an aqueous solution or water dispersion, and then dried and heat-treated. Is done by. The total solid concentration of the first treatment agent is 0.5 to 5% by weight, preferably 1 to 4% by weight. If the solid content concentration is too low, the adhesive surface tension increases, the uniform adhesion to the polyester fiber surface decreases, and the adhesion decreases due to a decrease in the solid content, and the solid content concentration decreases. If it is too high, the amount of solid content will be too large, the cord will become hard, and fatigue resistance may be reduced, which is not preferable.

  In addition, it is preferable to use a dispersant, that is, a surfactant in the first treatment agent at 10% by weight or less, preferably 5% by weight or less based on the total solid content of the dip liquid. If it exceeds 10% by weight, the adhesiveness is lowered.

    The solid content of the first treatment agent with respect to the polyester fiber is preferably in the range of 0.1 to 3% by weight, more preferably in the range of 0.3 to 2% by weight, based on the fiber weight. When the solid content is too low, the adhesiveness is lowered. On the other hand, when the solid content is too high, the cord becomes hard and fatigue resistance is lowered, which is not preferable.

  In order to control the solid content adhesion amount to the polyester fiber, for example, a method of squeezing with a pressure roller, scraping with a scrubber, etc., blowing with pressurized air, suction or the like after being immersed in a dip solution can be used. Moreover, in order to increase the amount of adhesion, it can also be made to adhere several times.

  The polyester fiber cord provided with the first treatment agent is dried at 70 to 120 ° C. for 0.5 to 3 minutes, and then heat treated at 200 to 255 ° C. for 0.5 to 5 minutes to form an adhesive film on the fiber surface. However, in some cases, drying can be omitted.

  When the temperature of the heat treatment is less than 200 ° C., the adhesive force may be insufficient, while at a high temperature exceeding 255 ° C., the treatment agent film formed on the fiber deteriorates and the adhesive force decreases, This is not preferable because the polyester fiber is thermally deteriorated and the strength is reduced.

  After the first treatment agent is applied as described above, a second treatment agent containing an acrylate latex is subsequently adhered.

  The second treatment agent containing the acrylate latex has a solid content concentration of 5 to 20% by weight, preferably 7 to 15% by weight. If it is less than 5% by weight, the solid content of the second treatment agent may be insufficient, and the adhesive strength may not be sufficient. When the solid content concentration exceeds 20% by weight, the storage stability of the treatment agent deteriorates, the solid content aggregates and the concentration changes, and it becomes difficult to uniformly attach the solid content to the polyester fiber cord surface. .

    The solid content adhesion amount of the second treating agent to the polyester fiber is in the range of 1 to 10% by weight, and preferably in the range of 1.5 to 7% by weight. If the solid content is too low, the adhesiveness will be reduced, while if the solid content is too high, the cord will be hard and fatigue resistance will be reduced, or the solid content will be gummed up in the roll during the process. However, operational stability deteriorates.

  In order to control the solid content adhesion amount to the polyester fiber, for example, a method such as squeezing with a pressure roller, scraping with a scrubber, blowing off with compressed air, suction, or the like can be used. Moreover, you may make it adhere several times in order to increase the adhesion amount.

  The polyester fiber cord provided with the second treatment agent is dried at 70 to 120 ° C. for 0.5 to 3 minutes, and then heat-treated at 200 to 255 ° C. for 0.5 to 5 minutes, whereby an adhesive coating is applied to the fiber surface. In some cases, drying can be omitted. When the temperature of the heat treatment is less than 200 ° C., the formation of the adhesive film on the fiber and the adhesion with the rubber may be insufficient. On the other hand, when the temperature is higher than 255 ° C., the treatment film formed on the fiber. Is deteriorated and the adhesive strength is reduced, or the polyester fiber is thermally deteriorated to be strongly reduced.

  Here, when a blocked isocyanate having a dissociation temperature of 130 ° C. to 180 ° C. is mixed with the second treatment agent, after drying at 70 to 120 ° C. for 0.5 to 3 minutes, the dissociation temperature of the blocked isocyanate or less It is preferable to heat-treat at a temperature of 0.5 to 5 minutes. In some cases, drying can be omitted. When the second treating agent mixed with the blocked isocyanate is heat-treated at a temperature exceeding the dissociation temperature, the cord becomes hard and the flexibility becomes poor, and the adhesion to the acrylic rubber may be insufficient. The cause of this is not clear, but by performing a heat treatment at a temperature higher than the dissociation temperature, the blocked agent of the blocked isocyanate is removed, the reaction between the isocyanates proceeds, and / or the reaction with the epoxy resin of the first treatment agent proceeds. Therefore, it is considered that the functional group effective for adhesion with the acrylic rubber is lost.

  Next, the rubber hose of the present invention will be described. As the shape of the rubber hose of the present invention, conventionally known ones can be applied, but one or two or more layers of reinforcing fibers are wound on the inner layer rubber and the outer layer rubber is coated thereon. Is preferred.

  The reinforcing fiber winding method includes a blade method in which one fiber and the other fiber are alternately wound up and down, a spiral method in which one fiber is wound and the other fiber is wound, and the like. Are shapes spaced apart from each other, but are not specified.

  The rubber hose vulcanization method includes vulcanization under dry heat and vulcanization under steam, and is usually performed at 150 ° C. to 170 ° C. for 30 minutes to 1 hour. The vulcanization method, vulcanization time and vulcanization are performed. Conditions such as sulfur humidity may be selected as appropriate.

  In the hose of the present invention, it is only necessary that the acrylic rubber is disposed in a state of touching the reinforcing fiber.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In addition, each measured value in a following example is calculated | required with the following method.

(1) Adhesive strength <rubber compounding prescription>
Acrylic rubber (Nippol AR31) 100 (parts by weight)
HAF carbon black 50 (parts by weight)
Stearic acid 2 (parts by weight)
Liquid paraffin 1 (parts by weight)
4,4'-methylenedianiline 1 (parts by weight)
The fiber cord was wound around an aluminum plate so that there was no gap, and acrylic rubber having the composition shown above was attached to one side of the aluminum plate, and press vulcanized at 150 ° C. for 30 minutes. At this time, the thickness of the rubber was 3 mm, and the press pressure was adjusted so that the surface pressure of the rubber and the fiber cord was 30 kgf / cm ² . The size of the aluminum plate and the area around which the fiber cord is wound may be arbitrary, and the tension at the time of winding is not required as long as the cord does not loosen when wound. After standing to cool, the peeling force when peeling the fiber cord from the rubber is displayed in N / inch while keeping the rubber and the fiber cord at an angle of 90 ° at a speed of 50 mm / min in an environment of 20 ° C. did.

(2) Cord hardness The Gurley bending index was used as an index. The sample was left in a temperature-controlled room at 20 ° C. and 65% RT for 24 hours or more, and then the fiber was cut into a 1-inch length, and “Gurley's stiffness tester” manufactured by Yasuda Seiki Co., Ltd. was used. Year), 6.20.1 (A method (Gurley method)), and the Gurley bending hardness was calculated using the following formula. The number of bendings was one reciprocation. The smaller the value, the more flexible.
S (Gurley bending hardness (mg)) = R × (W ₁ × 1 + W ₂ × 2 + W ₄ × 4) × L ₂ /W×3.96
W ₁ , W ₂ , W ₄ = Load (g) and mounting position, R = Scale reading, L = Cord length−0.5 (inch), W = Thread width (inch).

(3) Flexibility of hose The rubber compound described in the above adhesive strength evaluation is extruded with an extruder to form an inner tube, and a processing cord is densely braided on the outer tube. The article was extruded and coated as an outer tube. It was wound into a long shape and vulcanized in a steam can at 150 ° C. for 30 minutes to prepare a hose having an inner diameter of 16 mm and an outer diameter of 24 mm. The hose was cut to a length of 300 mm, both ends of the hose were held with both hands, and the hose was bent. The bent one was evaluated as “◯”, and the one not bent or bent was evaluated as “x”.

(4) With hose adhesive rubber JIS K 6330-6 (1998) cuts the hose after vulcanization into a 1-inch wide ring to form a test piece, and the interface between the treated cord and the outer rubber is 50 cm / min. It peeled at the speed of. The peeled surface was visually observed, and “も の” indicates that the state of rubber adhesion to the fiber is extremely good, “◯” indicates that it is good, and “×” indicates that the rubber is poor.

(Examples 1-6, Comparative Examples 1, 2, 5, 6)
Polyethylene terephthalate having a viscosity of 0.95 is melt-spun by a conventional method, and two 1100 dTex multifilament yarns obtained by drawing are drawn and twisted at a twist number of 10 times / 10 cm to obtain an untreated cord. . Polyepoxide (“Denacol” EX313 (manufactured by Nagase Kasei Co., Ltd.)) and acrylate latex (“Nippol” LX854E (manufactured by ZEON)) were mixed at a solid content weight ratio shown in Table 1 to give a total solid content of 3.0 weight. % Of the first treatment agent was obtained. Further, polyepoxide (“Denacol” EX313 (manufactured by Nagase Kasei Co., Ltd.)), acrylate latex (“Nippol” LX854E (manufactured by Nippon Zeon)), and blocked isocyanate compound (manufactured by Meisei Chemical Co., Ltd.) are shown in Table 1. To obtain a second treating agent having a total solid content of 10.0% by weight.

  The untreated code was immersed in the first treating agent using a computer treater processor (CA Ritzler Co., Ltd.), dried at 100 ° C. for 2 minutes, and subsequently heat treated at 230 ° C. for 1 minute. Subsequently, after immersing in the second treatment agent, drying was performed at 100 ° C. for 2 minutes, and subsequently heat treatment was performed at the temperature shown in Table 1 for 1 minute. The obtained treatment cord had a solid content of the first treatment agent of 1.0% and a solid content of the second treatment agent of 4.0%.

  The obtained treatment code was embedded in unvulcanized rubber, and the items shown in Table 1 were evaluated.

(Comparative Example 3)
The same treatment as in Example 1 was performed except that the first treatment agent was not applied. The solid content of the second treatment agent was 4.0%.

(Comparative Example 4)
The same treatment as in Example 1 was performed except that the second treatment agent was not applied. The solid content of the first treatment agent was 1.0%.

  As shown in Tables 1 and 2, the rubber fiber-reinforced polyester fiber cords according to the production method of the present invention have good adhesive strength and cord hardness, such as a hose with good adhesive strength and a flexible and easy to handle hose. It turns out that it is obtained.

Claims (6)

  Applying a first treatment agent containing an epoxy resin to a twisted cord of a polyester fiber obtained by melt spinning, stretching and twisting polyester, followed by heat treatment, and subsequently applying a second treatment agent containing an acrylate latex A method for producing a polyester fiber cord for reinforcing rubber, which is characterized.   The method for producing a rubber-reinforced polyester fiber cord according to claim 1, wherein the second treatment agent contains a blocked isocyanate compound having a dissociation temperature of 130C to 180C.   The method for producing a polyester fiber cord for reinforcing rubber according to claim 2, wherein the heat treatment after the second treatment agent is applied is performed at a temperature equal to or lower than the dissociation temperature of the blocked isocyanate compound.   The method for producing a rubber fiber-reinforced polyester fiber cord according to claim 2 or 3, wherein the content of the blocked isocyanate compound in the total solid content of the second treating agent is 20 to 50% by weight.   The method for producing a polyester fiber cord for rubber reinforcement according to any one of claims 1 to 4, wherein the second treatment agent contains 10 to 50% by weight of an epoxy resin in the total solid content of the second treatment agent. .   A rubber hose comprising acrylic rubber reinforced with a polyester fiber cord for rubber reinforcement obtained by the production method according to claim 1.