JP2008169504A - Adhesion-treating agent for rubber and fiber, synthetic fiber cord for reinforcing rubber, and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesion-treating agent for fiber and rubber, which has reduced deterioration in adhesion under a high temperature in a state of being buried in rubber of a tire, belt, hose, etc., for a long period of time, and also inhibits fatigue deterioration in a state of being buried in the rubber and receiving repeated stretch and compression, a synthetic fiber cord for reinforcing the tire, and a method for producing the same. <P>SOLUTION: This adhesion-treating agent for the fiber and rubber is obtained by blending a polyepoxide compound, a blocked polyisocyanate compound, a silicate compound, and rubber latex of an ethylenically unsaturated acid-modified styrene-butadiene which has a glass transition point (Tg) of 0-35°C. The synthetic fiber cord for reinforcing the rubber is obtained by treating a twisted yarn cord obtained by twisting synthetic fibers, with the treating agent. The method for producing the synthetic fiber cord for reinforcing the rubber includes treating the twisted yarn cord obtained by twisting the synthetic fibers, with the treating agent, then drying and heat-treating the cord. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an adhesive treatment agent for rubber / fiber which improves the adhesion between rubber and synthetic fiber, a synthetic fiber cord for rubber reinforcement whose adhesion to rubber is improved by coating with this treatment agent, and its It relates to a manufacturing method. In more detail, there is little adhesion deterioration under high temperature for a long time when embedded in rubber such as tires, rubber hoses and belts, and it suppresses fatigue deterioration when embedded in rubber and repeatedly stretched and compressed. The present invention relates to an adhesive treatment agent for rubber and fibers, a synthetic fiber cord for rubber reinforcement, and a method for producing the same.

  Polyester fibers have been widely used as a reinforcing material for rubber products such as tires, belts and hoses because they have excellent mechanical strength and low extensibility.

  These rubber reinforcing polyester fibers are used by being embedded in a rubber product as a reinforcing material, so that the durability is also affected by various compounds blended in the rubber.

  For example, rubber is often compounded with vulcanization accelerators such as tyrium-based, sulfenamide-based, or guanidine-based compounds, and amine-based anti-aging agents. These additive compounds are used in automobile tires. For the reinforcement of rubber by inducing deterioration of polyester fibers during vulcanization process during high-speed production, during high-speed running, and during vulcanization process during hose production or when used in a high-temperature atmosphere in the engine room. There has been a problem that the performance as a fiber tends to be significantly reduced.

  In particular, when rubber is vulcanized using steam, the polyester fiber in the rubber is also affected by hydrolysis by steam, so that there is a problem that the fiber is significantly deteriorated.

  For this reason, in recent years, various studies have been made for the purpose of improving the above-mentioned drawbacks. For example, a technique of blending rubber with a vulcanization accelerator or an anti-aging agent that causes little deterioration to the polyester fiber. However, such a method has a problem in that it is difficult to obtain a vulcanized rubber satisfying various performances because the composition of the rubber is remarkably restricted.

  On the other hand, many attempts have been made to improve the above-mentioned drawbacks by improving the polyester fiber itself. For example, a method for reducing the amount of terminal carboxyl groups contained in the polyester fiber has been proposed. In fact, it is difficult to obtain the effect of suppressing the deterioration of the fibers to a practical level.

  In addition, for the purpose of improving the above-described drawbacks, various studies mainly from the viewpoint of the fiber treatment agent have been conducted, and disclosed techniques include, for example, Patent Documents 1 to 4.

  In Patent Document 1, a linear aromatic polyester pretreated with a polyepoxide compound is treated with a first treating agent containing a polyepoxide compound and N-methoxymethyl nylon, and then an ethylene urea compound is added to resorcin / formalin latex. A method for treating polyester fiber treated with a second treating agent comprising a cresol novolac type epoxy compound is disclosed.

  Patent Document 2 discloses a formulation in which polyester fibers are treated with a resorcin / formalin latex and a treatment liquid containing a reaction product of a resorcin sulfide compound, a parachlorophenol compound, and a formaldehyde resin.

  Patent Document 3 is a one-step process combining (A) a treatment liquid containing a carrier, (B) a blocked isocyanate aqueous solution, (C) a dispersion of an epoxy compound, and (D) a resorcin-formaldehyde-latex mixed liquid. Alternatively, a technique for treating a polyester fiber material by multistage treatment of two or more stages is disclosed.

  In Patent Document 4, a polyester fiber is treated with a first treatment liquid containing a polyepoxide compound, a blocked isocyanate compound, a rubber latex, and a silicate compound, and then modified with a resorcin / formalin initial condensate and an ethylenically unsaturated acid. A method of treating with a second treating agent containing a rubber latex is disclosed.

Although the above-mentioned patent literature techniques are not sufficient, although improvement in heat-resistant adhesion and heat-resistant strength retention at high temperatures is recognized as compared with conventional polyester fiber bonding methods.
JP 62-21875 A (Claims) Japanese Patent Laid-Open No. 6-341062 (Claims) JP 2006-2327 A (Claims) JP-A-9-209277 (Claims)

  The present invention has been made as a result of studying the solution of the above-described problems in the prior art as an issue.

  Therefore, the main object of the present invention is to reduce fatigue deterioration under high temperature for a long time when embedded in rubber such as tires, belts and hoses, and fatigue when repeatedly embedded in rubber and subjected to repeated compression. An object of the present invention is to provide an adhesive treatment agent for rubber and fibers, a synthetic fiber cord for reinforcing rubber, and a method for producing the same.

  The present invention employs the following means in order to solve such problems. That is, the present invention includes a polyepoxide compound, a blocked polyisocyanate compound, a silicate compound, and an ethylenically unsaturated acid-modified styrene / butadiene rubber latex having a glass transition temperature (Tg) of 0 ° C. to 35 ° C. An adhesive treatment agent for rubber and fibers.

  In the adhesive treatment agent for rubber / fiber of the present invention, the following (1) to (3) are preferable conditions, and further excellent effects can be expected by applying these conditions.

  (1) The breaking elongation of the dry latex film of the ethylenically unsaturated acid-modified styrene / butadiene rubber latex is 5% to 400%.

  (2) The treating agent is a treating agent containing another rubber latex in addition to the ethylenically unsaturated acid-modified styrene / butadiene rubber latex, wherein the ethylenically unsaturated acid-modified styrene / butadiene rubber latex and the other rubber The total amount of latex is 100 parts by weight, and the ethylenically unsaturated acid-modified styrene / butadiene rubber latex is 20 to 50 parts by weight (dry part by weight).

  (3) In addition to (a) a conjugated diene monomer 40 to 50% by weight, (b) a vinylpyridine monomer 13 to 20% by weight, and (c) a styrene monomer 25 to 35. It contains a terpolymer rubber latex consisting of% by weight and having a glass transition temperature (Tg) of -40 ° C to -10 ° C.

  Moreover, this invention is a synthetic fiber cord for rubber reinforcement by which the said processing agent is coat | covered by the surface layer of the twisted-yarn cord of a synthetic fiber.

  In addition, in the synthetic fiber cord for rubber reinforcement of the present invention, the following (1) and (2) are preferable conditions, and further excellent effects can be expected by applying these conditions.

  (1) The cord surface layer is further coated with a treating agent containing a resorcin / formalin initial condensate and an ethylenically unsaturated acid-modified styrene / butadiene rubber latex having a glass transition temperature (Tg) of 0 ° C. to 35 ° C. Being.

  (2) The synthetic fiber is a polyester fiber or an aromatic polyamide fiber.

  Further, the present invention provides a rubber-reinforcing composition characterized in that a twisted cord obtained by twisting synthetic fibers is treated with the treatment agent, dried at 100 to 150 ° C, and heat-treated at 200 to 245 ° C. It is a manufacturing method of a fiber cord.

  In the method for producing a polyester fiber cord for reinforcing rubber according to the present invention, the cord surface layer is continuously composed of a resorcin / formalin initial condensate and an ethylenically unsaturated acid-modified styrene / glass transition temperature (Tg) of 0 ° C. to 35 ° C. Treatment with a treatment agent containing butadiene rubber latex, drying at 100 to 150 ° C., and heat treatment at 220 to 250 ° C. are preferable conditions. By applying these conditions, further excellent effects can be expected.

  According to the rubber / fiber adhesive treatment agent, rubber reinforcing synthetic fiber cord of the present invention, and a method for producing the same, there is little adhesion deterioration under high temperature for a long time when embedded in rubber, and embedded in rubber. Thus, a synthetic fiber cord for rubber reinforcement that suppresses fatigue deterioration when repeatedly subjected to stretch compression is obtained.

  The rubber / fiber adhesive treatment agent of the present invention comprises a polyepoxide compound, a blocked polyisocyanate compound, a silicate compound, and an ethylenically unsaturated acid-modified styrene / butadiene having a glass transition temperature (Tg) of 0 ° C. to 35 ° C. The rubber latex is an essential component, and even if any of these is missing, the effect of the present invention is not exhibited.

  Although it does not specifically limit as a polyepoxide compound used for this invention, Reaction of polyhydric alcohols, such as pentaerythritol, sorbitol, ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, and halogen-containing epoxides such as epichlorohydrin Products, resorcinol, bis (4-hydroxyphenyl) dimethylmethane, phenol / formaldehyde resins, reaction products of polyphenols such as resorcin / formaldehyde resins with the halogen-containing epoxides, bis- (3,4-epoxy) And polyepoxide compounds obtained by oxidizing unsaturated bond moieties such as -6-methyl-dicyclohexylmethyl) adipate and 3,4-epoxycyclohexene epoxide.

  Among these, a reaction product of polyhydric alcohols and epichlorohydrin (polyglycidyl ether compound of polyhydric alcohol) is preferable.

  In addition, the blocked polyisocyanate compound used in the present invention is one in which a blocking agent is released by heating to produce an active isocyanate compound. Specifically, tolylene diisocyanate, metaphenylene diisocyanate, diphenylmethane diisocyanate. , Polyisocyanate compounds such as hexamethyline diisocyanate and triphenylmethane triisocyanate and phenols such as phenol, cresol and resorcin, lactams such as ε-caprolactam and valerolactam, oximes such as acetoxime, methyl ethyl ketoxime and cyclohexane oxime, etc. The reaction product with the blocking agent is mentioned.

  Among these blocked polyisocyanate compounds, aromatic polyisocyanate compounds blocked with ε-caprolactam and aromatic compounds of diphenylmethane diisocyanate give good results.

  The silicate compound used in the adhesive treatment agent for rubber / fiber of the present invention is an inorganic compound containing silicon, magnesium, sodium and lithium as constituent elements, and further contains fluorine and / or aluminum. Generally, it is a synthetic inorganic compound called smectite.

  The content ratio of silicon / magnesium in the silicate compound is preferably 1 / (0.1 to 1.0) from the viewpoint of developing adhesiveness. Further, it is important that the light transmittance T of the 1% aqueous dispersion is 50% or more, particularly 60% or more, and the thixotropic index of the 1% aqueous dispersion is 2.0 to 10.0, particularly It is preferably in the range of 3.0 to 9.0, and more preferably in the range of specific surface area of 100 to 500, particularly 150 to 400.

  The light transmittance T, the thixotropy index, and the specific surface area as used in the present invention are values obtained by the following method.

  [Light transmittance] After thoroughly stirring a 1% aqueous dispersion of a silicate compound, the mixture was allowed to stand for one day and night, and only the aqueous dispersion not precipitated and separated was placed in a 10 mm cell, and a U-3000 type spectrophotometer. It is the value which measured the light transmittance in wavelength 500nm using (made by Hitachi, Ltd.).

[Thixotropic index] After thoroughly stirring a 2% aqueous dispersion of a silicate compound, the mixture was allowed to stand for a day and night, and the viscosity of the aqueous dispersion that had not settled and separated was measured with a B-type viscometer (manufactured by Shibaura System). Is a value calculated by the following equation. The rotor is no. No. 3 and 6 rpm and 60 rpm are both left for 2 minutes before measurement, and read the instructions after 1 minute rotation.
TI = (viscosity at 6 rpm) / (viscosity at 60 rpm)

[Specific surface area] After weighing a specific cell of a specific surface area simple soap (manufactured by Yuasa Ionics Co., Ltd.), about 1/2 (about 0.15 g) of a silicate compound was packed in this cell, and weighed by a conventional method. It is a value calculated by the following equation after measurement with a soap.
Specific surface area (m ² /g)=(A/AC)×(V×2.81/sample amount g)
A: Accumulator value after the cell is removed from liquid nitrogen and immersed in room temperature water AC: Accumulator value after injection of pure liquid nitrogen gas V: A / 1300

  When the silicate compound, especially synthetic smectite, is dispersed in water, it becomes a thixotropic dispersion, has a function of obtaining a stable viscosity and increasing the specific surface area.

  Therefore, the silicate compound acts as a permeation suppressor and a softening agent, and the rubber / fiber adhesive treatment agent containing the silicate compound is stable and excellent even when the amount of adhesion to the synthetic fiber is reduced. Not only can the adhesiveness with the rubber be obtained, but the treated cord becomes flexible, and a reduction in cord strength is effectively prevented.

  That is, since the silicate compound has a large number of hydroxyl groups on the surface, it adsorbs water molecules in the adhesive composition and penetrates into the fiber cord, and is used as a treatment agent such as an epoxy compound, an isocyanate compound and a rubber latex. Since the penetration into the fiber cord is suppressed, when the fiber cord is heat treated in this state, the treatment agent component is solidified in the surface layer portion of the fiber cord, and the silicate compound is mainly contained in the inner layer portion of the fiber cord. As a result, the flexibility between the fiber single yarns in the inner layer of the cord is increased, so that the flexibility of the fiber cord is improved and the high strength of the fiber cord itself is maintained.

  In addition, the formulation of silicate compounds suppresses the aggregation of adhesive matrix components such as rubber latex in the adhesive composition, and each adhesive matrix component is uniformly mixed and stabilized. Since it adheres evenly to the fiber surface under force, even with a small amount of adhesion, excellent adhesion to rubber can be obtained.

  It is necessary to mix | blend the ethylenically unsaturated acid modified styrene butadiene rubber latex whose glass transition temperature (Tg) is 0 degreeC-35 degreeC with the adhesion treatment agent for rubber | gum and fiber of this invention. The latex adheres to the surface of the polyester fiber through a polyepoxide compound, isocyanate compound, silicate compound, and forms strong bonds between the fiber and rubber to form hydrogen bonds with the polar groups of the rubber material. It is interpreted that

  Examples of ethylenically unsaturated acids used for the modification of styrene / butadiene rubber latex include acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, itaconic acid, fumaric acid, maleic acid, butenetricarboxylic acid and other unsaturated carboxylic acids, Unsaturated monocarboxylic esters of unsaturated dicarboxylic acids such as itaconic acid monoethyl ester, fumaric acid monobutyl ester and maleic acid monobutyl ester, sulfoethyl sodium acrylate, sulfopropyl sodium methacrylate, acrylamide propane sulfonic acid, etc. A sulfonic acid or its alkali salt etc. are mentioned, These can be used 1 type or in combination of 2 or more types. The content of the unsaturated acid monomer in the latex is preferably 0.5 to 8% by weight.

  In addition, you may introduce | transduce into a rubber latex by hydrolyzing a carboxyl group after copolymerizing an ethylenically unsaturated ester monomer or an ethylenically unsaturated acid anhydride monomer. In this case, the ethylenically unsaturated acid ester monomer and the ethylenically unsaturated acid anhydride monomer include acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, itaconic acid, fumaric acid, maleic acid, butenetricarboxylic acid. Illustrative are mono-, di- and triesters of unsaturated carboxylic acids such as acids, maleic anhydride and the like, and one or more of these are used.

  Further, the glass transition temperature (Tg) of the ethylenically unsaturated acid-modified styrene / butadiene rubber latex needs to be 0 to 35 ° C., and more preferably 5 to 30 ° C. If it is lower than 0 ° C, the adhesion to rubber may be insufficient, and if it exceeds 35 ° C, the cord becomes hard and the bending fatigue property may be deteriorated.

  The ethylenically unsaturated acid-modified styrene / butadiene rubber latex preferably has a breaking elongation of a dry latex film of 5% to 400%, more preferably 10% to 300%. If it is less than 5%, the cord becomes hard and the fatigue resistance may deteriorate. If it exceeds 400%, sufficient adhesive strength may not be exhibited.

  In addition to the ethylenically unsaturated acid-modified styrene / butadiene rubber latex, other rubber latex can be added to the rubber / fiber adhesion treating agent of the present invention as required. When other rubber latex is added, the total amount of the ethylenically unsaturated acid-modified styrene / butadiene rubber latex and the other rubber latex is 100 parts by weight, and the ethylenically unsaturated acid-modified styrene / butadiene rubber latex is 20 to 50 weights. It is preferable to add so that a part (dry weight part) may be contained. If it is out of this range, the heat-resistant adhesive strength may decrease.

  Specific examples of rubber latex that can be added include styrene butadiene rubber latex, polybutadiene rubber latex, vinylpyridine styrene butadiene rubber latex, acrylonitrile butadiene rubber latex, chloroprene rubber latex, chlorosulfonated polyethylene rubber latex, and acrylate rubber. Examples thereof include latex and natural rubber latex.

  Among these, vinylpyridine styrene butadiene rubber latex is preferably blended from the viewpoint of adhesiveness. More preferably, (B) conjugated diene monomer is 40 to 50% by weight, (B) vinylpyridine monomer is 13 to 20% by weight, and (C) styrene monomer is 25 to 35% by weight. Ternary copolymer vinylpyridine styrene butadiene rubber latex is preferred. When it is within this range, the adhesive strength to rubber is high, and the cost of raw materials is advantageous. As such a latex, for example, “Pilatex-LB” (manufactured by Nippon A & L Co., Ltd.) is available as a commercial product.

  More preferably, the glass transition temperature (Tg) of the vinylpyridine styrene butadiene rubber latex is preferably −40 ° C. to −10 ° C. If it is out of this range, both the adhesive strength and heat resistant adhesive strength may deteriorate.

  The rubber / fiber adhesive treatment agent of the present invention comprises a polyepoxide compound, a blocked polyisocyanate compound, a silicate compound, and an ethylenically unsaturated acid-modified styrene / butadiene having a glass transition temperature (Tg) of 0 ° C. to 35 ° C. The total amount of rubber latex is preferably 100 to 25 parts by weight, preferably 12 to 25 parts by weight of polyepoxide compound, more preferably 15 to 20 parts by weight, and preferably 25 to 45 parts by weight of blocked polyisocyanate compound, more preferably 30 to 30 parts by weight. An ethylenically unsaturated acid-modified styrene / butadiene rubber latex containing 40 parts by weight of a polyepoxide compound, a blocked polyisocyanate compound, and a glass transition temperature (Tg) of 0 ° C. to 35 ° C. For 100 parts by weight of the total amount of 1-10 parts by weight Lee acid salt compound, and it is more preferred to be in a proportion of 2 to 5 parts by weight. In the case of the above ratio, the adhesiveness of the rubber reinforcing cord is excellent.

  Since the adhesive treatment agent for rubber / fiber of the present invention having the above-described structure is capable of uniformly adhering the adhesive matrix component to the surface of the synthetic fiber by adding the silicate compound, the adhesive for synthetic fiber Even if the adhesion amount is reduced, it is possible to exhibit excellent adhesion to rubber, and it is possible to obtain a high-quality rubber reinforcing cord that is flexible and has excellent fatigue resistance. Moreover, the addition of the styrene / butadiene rubber latex modified with an ethylenically unsaturated acid makes it possible to obtain a rubber reinforcing cord having good heat-resistant adhesive strength.

  The synthetic fiber cord for reinforcing rubber according to the present invention is formed on the surface layer of the twisted cord of the synthetic fiber. The treatment agent for rubber / fiber according to the present invention (polyepoxide compound, blocked isocyanate compound, silicate compound, and glass rearrangement) The temperature (Tg) is coated with a treatment agent containing an ethylenically unsaturated acid-modified styrene / butadiene rubber latex having a temperature of 0 to 35 ° C. Here, the preferred embodiments of the polyepoxide compound, the blocked isocyanate compound, the silicate compound, and the ethylenically unsaturated acid-modified styrene / butadiene rubber latex are used in the rubber / fiber adhesive treatment agent of the present invention described above. Can be used.

  As the synthetic fiber that can be used in the present invention, either a polyester fiber or an aromatic polyamide fiber is preferably used.

  The polyester fiber that can be used in the present invention is preferably a fiber obtained by melt spinning and drawing a polyester having terephthalic acid as a main bifunctional carboxylic acid and ethylene glycol as a main glycol component. Part or all of 2,6-naphthalenedicarboxylic acid, 4,4-dicarboxyphenoxyethane, an isocyanate group or the like, or a part or all of ethylene glycol replaced with diethylene glycol, propylene glycol, butanediol, or the like Even fibers can be used.

  The polyester may be a copolymer of trifunctional compounds such as trimesic acid, trimellitic acid, boric acid, phosphoric acid, glycerin, and trimethylolpropane as long as the amount is small.

  The polyester fiber may be modified with various modifiers, for example, terminal carboxyl group blocking agents such as carbodiimide compounds, epoxy compounds, isocyanate compounds, and oxazoline compounds.

  The polyester fiber spinning method may be a method in which spinning and drawing are performed in two stages, or a method in which both processes are performed in one stage.

  The polyester fiber used in the present invention includes not only filament yarns made of the above polyester but also cords, woven fabrics, woven fabrics, and the like made of the filament yarns. May be applied to any form of polyester fiber.

  The aromatic polyamide fiber of the present invention is preferably made of poly-P-phenylene terephthalamide, poly-P-phenylene-3-4′diphenyl ether terephthalamide, and a copolymer mainly composed of these. used.

  The synthetic fiber used in the present invention is not restricted by the fineness, the number of filaments, the cross-sectional shape, etc., but usually the fineness is preferably 200 to 5000 dtex, and more preferably 250 to 3000 dtex. The number of filaments is preferably 30 to 1000 filaments, more preferably 50 to 500 filaments. Furthermore, the cross-sectional shape is preferably circular.

  The synthetic fiber cord for rubber reinforcement of the present invention is obtained by twisting the above fiber into a raw cord, and woven the raw cord as it is or directly into a raw fabric, followed by an adhesive treatment. Raw cords used for ordinary tire cords are twisted in the S or Z direction, and then two or three lower twisted cords are combined and the same number of upper twists are applied in the opposite direction to the lower twisted to form various twisted cords. Is. Next, the raw cord is used as a warp, and the weft is covered with a cotton yarn or the synthetic fiber is covered with a cotton yarn to obtain a weft, which is woven into a raw fabric. Next, the ginger fabric is treated with an adhesive to obtain a dip fabric.

  On the other hand, in the case of a hose or belt, apply the lower twist and keep the lower twist cord, or, as described above, apply two or three of them together and apply the same number of upper twists in the opposite direction to the lower twist, and then the various twist cords Then, the adhesive is treated in the form of a cord to obtain a dip cord.

  Further, the polyester fiber cord for rubber reinforcement of the present invention is treated with the treatment agent (hereinafter abbreviated as “first treatment agent”), and then the resorcin / formalin initial condensate and the glass transition temperature (Tg) are 0. It is preferable from the viewpoint of improving adhesiveness that it is treated with a treating agent (hereinafter abbreviated as “second treating agent”) containing an ethylenically unsaturated acid-modified styrene / butadiene rubber latex having a temperature of ˜35 ° C. .

  The resorcin / formalin initial condensate is obtained by condensing resorcin and formalin in the presence of an alkali catalyst, and the molar ratio of resorcin to formalin is 1.00: 0.75-1.00: 3.00. Preferably, the range of 1.00: 1.00 to 1.00: 2.00 is good.

  In addition, in order to further improve the adhesive force with rubber, the above-mentioned second treatment agent is blended with the blocked polyisocyanate compound, or 2,6-bis (2 ′, 4′-dihydroxyphenylmethyl). ) It is preferably used as a blend of a reaction product of a halogenated phenol such as -4-chlorophenol and resorcin / formaldehyde.

  In addition to the ethylenically unsaturated acid-modified styrene / butadiene rubber latex, the second treating agent of the present invention may contain other rubber latex as required. When other rubber latex is added, the total amount of the ethylenically unsaturated acid-modified styrene / butadiene rubber latex and the other rubber latex as the second treating agent is 100 parts by weight, and the ethylenically unsaturated acid-modified styrene / butadiene rubber latex is used. Is preferably added so as to contain 20 to 50 parts by weight (dry part by weight). If it is out of this range, the heat-resistant adhesive strength may decrease.

  Specific examples of rubber latex that can be added include styrene butadiene rubber latex, polybutadiene rubber latex, vinylpyridine styrene butadiene rubber latex, acrylonitrile butadiene rubber latex, chloroprene rubber latex, chlorosulfonated polyethylene rubber latex, and acrylate rubber. Examples thereof include latex and natural rubber latex.

  Resorcin / formalin initial condensate and rubber latex in this second treating agent (total amount of ethylenically unsaturated acid-modified styrene / butadiene rubber latex having a glass transition temperature (Tg) of 0 to 35 ° C. and other rubber latex) Is preferably in the range of 1: 3 to 1:12, and more preferably 1: 4 to 1: 9 in terms of solid content.

  When a blocked polyisocyanate compound is added to the second treating agent, the amount added is a resorcin / formalin initial condensate which is a solid content of the second treating agent, ethylene having a glass transition temperature (Tg) of 0 to 35 ° C. The range of 5 to 25 parts by weight, more preferably 10 to 20 parts by weight, is preferable with respect to 100 parts by weight of the total amount of the unsaturated acid-modified styrene / butadiene rubber latex and other rubber latex. In addition, when a reaction product of a co-condensate of parachlorophenol, resorcin, and formaldehyde is added to the second treating agent, the amount added is a resorcin / formalin initial condensate that is a solid content of the second treating agent, glass The range of 20 to 40 parts by weight is preferable with respect to 100 parts by weight of the total amount of the ethylenically unsaturated acid-modified styrene / butadiene rubber latex and other rubber latex having a rearrangement temperature (Tg) of 0 to 35 ° C.

  The adhesion amount of the first treating agent of the present invention is preferably 0.8 to 3.0 parts by weight, particularly 1.0 to 2.5 parts by weight with respect to 100 parts by weight of the synthetic fiber twisted cord. If it is less than 0.8 part by weight, the adhesion to rubber may be lowered, and if it exceeds 3.0 parts by weight, the cord becomes hard and fatigue resistance may be deteriorated.

  Moreover, the adhesion amount of the 2nd processing agent of this invention is 0.8-3.0 weight part with respect to 100 weight part of synthetic fiber twisted cords, Especially 1.0-2.5 weight part is preferable. If it is less than 0.8 part by weight, the adhesion to rubber may be lowered, and if it exceeds 3.0 parts by weight, the cord becomes hard and fatigue resistance may be deteriorated.

  Hereafter, the manufacturing method of the synthetic fiber cord for rubber reinforcement of this invention is explained in full detail.

  In the method for producing a synthetic fiber cord for reinforcing rubber according to the present invention, the first treatment agent is applied to a twisted cord of synthetic fiber, followed by drying preferably at a temperature of 100 to 150 ° C, and subsequently 200 to 245 ° C. The synthetic fiber cord of the present invention can be obtained by performing a heat treatment at. Further, from the viewpoint of improving adhesiveness, following the treatment step, the second treatment agent is applied, preferably dried at a temperature of 100 to 150 ° C., and subsequently heat treated at 200 to 250 ° C. It is possible to obtain a rubber reinforcing cord having extremely excellent adhesive strength.

  In addition, as a method for applying the first treatment agent and the second treatment agent to the synthetic fiber, any method such as contact with a roller, application by spraying from a nozzle, or immersion in a liquid bath may be employed. Can do.

  Moreover, in order to control the solid content adhesion amount of each processing agent to the synthetic fiber, means such as squeezing by a pressure roller, scraping by a scraper, blowing by air blowing, and suction may be used.

  Furthermore, a braiding softening process for obtaining an arbitrary cord stiffness can be performed by sliding the cord against the edge after the drying and heat treatment.

  This first bath treatment agent is usually used at a total solid concentration of 2 to 12% by weight, preferably 4 to 8% by weight, and the amount of adhesion to the synthetic fiber is 0% by weight with respect to 100 parts by weight of the synthetic fiber. It is optimal to set it to 8 to 3.0 parts by weight. When the solid content concentration of the first treatment agent and the amount of adhesion to the synthetic fiber are within the preferred ranges, the adhesion rate to the synthetic fiber does not become excessive, and the fatigue resistance is excellent, while the synthetic fiber and the rubber are bonded to each other. It will be excellent in power.

  Further, the second treatment agent is usually used at a total solid content concentration of 5 to 20% by weight, preferably 7 to 15% by weight, and the amount attached to the polyester fiber is 0 by dry weight with respect to 100 parts by weight of the synthetic fiber. It is optimal to set it to 8 to 3.0 parts by weight. When the solid content concentration of the second treatment agent and the amount of adhesion to the synthetic fiber are in the preferred range, the adhesion rate to the synthetic fiber does not become excessive and the fatigue resistance is excellent, while the synthetic fiber and the rubber are bonded to each other. It will be excellent in power.

  The synthetic fiber cord for rubber reinforcement of the present invention thus obtained has excellent adhesion to rubber and superior heat-resistant adhesive strength compared to those treated with a conventional adhesive composition, for example, for automobiles. In fields such as tires, conveyor belts, V-belts and hoses, it is possible to provide extremely high-grade rubber-reinforced products.

  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 the examples specifically described below, each measured value is obtained by the following method.

(1) Cord strength Measured by the method of JIS L1017 (2002) 8.5a) standard time test using a “Tensilon UTL-4L” type tensile tester (Orientec Co., Ltd.).
The descending speed was 300 mm / min, the number n was 8, and the average value was the cord strength.

(2) T-initial adhesive strength and T-heat resistant adhesive strength This indicates the adhesive strength between the treatment cord and rubber. In accordance with JIS L-1017 (1983) Adhesive Strength-A method, the treated cord is embedded in unvulcanized rubber, the initial adhesive strength under pressure is 150 ° C. for 30 minutes, and the heat resistant adhesive strength is 170 ° C. for 70 minutes. Press vulcanization was performed, and after cooling, the cord was pulled out from the rubber block at a speed of 300 mm / min, and the load required for the drawing was displayed in N / cm.

(3) Fatigue resistance (Goodrich disc fatigue)
According to JIS L 1017 (1983), after a fatigue was repeatedly given at 1705 rpm for 24 hours at an elongation rate of 5% and a compression rate of 15%, the strong residual rate was shown as 100 minutes.

(4) Glass transition point (Tg) of latex
It measured using the differential scanning calorimeter apparatus (DSC-50: Shimadzu Corporation make). 10 mg of latex dried at room temperature in advance was sealed in a predetermined aluminum pan, heated from -50 ° C. to 100 ° C. at a rate of 5 ° C./min, and the glass transition point of each latex was measured.

(5) Breaking elongation of dried latex film Sodium polyacrylate is added to the latex at a ratio of 0.5% D / D, mixed, coated on a glass plate, and dried at room temperature for 1 day. A film-like sample (thickness of about 0.5 mm) was further heated at 120 ° C. for 15 minutes to obtain a dry latex film. This was subjected to a tensile test using Tensilon to determine the elongation at break.

In addition, the composition of the rubber compound used for the measurement of (2) T-adhesive strength and (3) fatigue resistance is as follows.
Natural rubber (RSS # 1): 80 (parts by weight)
SBR (JSR1501): 30 (parts by weight)
SRF carbon black: 40 (parts by weight)
Stearic acid: 2 (parts by weight)
Sulfur: 2 (parts by weight)
Zinc flower: 5 (parts by weight)
2,2′-dithiobenzothiazole: 2 (parts by weight)
Naphthenic acid process oil: 3 (parts by weight).

The polyepoxide compound, blocked polyisocyanate compound, silicate compound, and rubber latex used in the present invention are as follows.
(Polyepoxide compound)
Sorbitol polyglycidyl ether: “Denacol” (registered trademark) EX-614B (manufactured by Nagase Kasei Co., Ltd.)
(Blocked polyisocyanate compound)
Diphenylmethane bis 4,4-ethylene urea: FS-50 (manufactured by Meisei Chemical Co., Ltd.)
(Silicate compound)
Synthetic smectite: “Lucentite” (registered trademark) SWF (manufactured by Coop Chemical Co., Ltd.)
(Rubber latex)
Vinylpyridine-styrene-butadiene rubber latex: “Pilatex” (registered trademark) (manufactured by Nippon A & L Co., Ltd.), solid content concentration: 41%, Tg: −55 ° C.
Vinylpyridine-styrene-butadiene rubber latex: “Pilatex-LB” (registered trademark) (manufactured by Nippon A & L Co., Ltd.), solid content concentration: 38%, Tg; −25 ° C.
Styrene-butadiene rubber latex: J9049 (manufactured by Nippon A & L Co., Ltd.), solid content concentration: 49%, Tg; -40 ° C
Ethylenically unsaturated acid-modified styrene-butadiene butadiene rubber latex: “Nalstar” (registered trademark) SR-100 (manufactured by Nippon A & L Co., Ltd.), solid content concentration: 51.0%, Tg 25 ° C., elongation at break; 25 %
Ethylenically unsaturated acid modified styrene-butadiene butadiene rubber latex: “Nalstar” (registered trademark) SR-102 (manufactured by Nippon A & L Co., Ltd.), solid content concentration: 48.0%, Tg; 21 ° C., elongation at break 390%
Ethylenically unsaturated acid modified styrene-butadiene butadiene rubber latex: “Nalstar” (registered trademark) SR-103 (manufactured by Nippon A & L Co., Ltd.), solid content concentration: 48.0%, Tg; 5 ° C., elongation at break ; 420%
Ethylenically unsaturated acid modified styrene-butadiene butadiene rubber latex: “Nalstar” (registered trademark) SR-104 (manufactured by Nippon A & L Co., Ltd.), solid content concentration: 48.0%, Tg; 3 ° C., elongation at break 450%
Ethylenically unsaturated acid modified styrene-butadiene butadiene rubber latex: “Nalstar” (registered trademark) SR-108 (manufactured by Nippon A & L Co., Ltd.), solid content concentration: 46.0%, Tg: −9 ° C., elongation at break Degree; 300%
Ethylenically unsaturated acid modified styrene-butadiene butadiene rubber latex: “Nalstar” (registered trademark) SR-110 (manufactured by Nippon A & L Co., Ltd.), solid content concentration: 47.0%, Tg: −27 ° C., elongation at break Degree; 940%

(Examples 1-10, Comparative Examples 1-10)
As the first bath treatment liquid, mixed liquids having a solid content concentration of 5.5% shown in Tables 1 and 2 were prepared.

  As the RFL of the second bath treatment liquid, an initial condensate obtained by reacting 1.50 mol of formalin with 1 mol of resorcin in the presence of alkali and a rubber latex mixture shown in Tables 1 and 2 The mixture was mixed at a weight ratio of 1/8 and aged for 24 hours. Next, 10 parts by weight of methyl ethyl ketoxime blocked diphenyl diisocyanate dispersion was mixed with 100 parts by weight of the RFL to prepare a second bath treatment liquid having a solid concentration of 10%.

  On the other hand, melt-spun and stretched 1670 dtex with a yarn viscosity of 0.95, two polyester fibers of 360 filaments were twisted at a twist number of 40 twists / 10 cm and 40 twists / 10 cm to obtain a raw cord .

Then, using a compute Lee coater single dipping Machine (manufactured by US Rittsura Ltd.), with respect to the raw cord, and applying the first treatment liquid, air wiper pressure performs the liquid cut under the conditions of 0.2 kg / cm ^2, Subsequently, the film was dried at 120 ° C. for 100 seconds, and subsequently heat-treated at 240 ° C. for 45 seconds.

Next, the second treatment liquid was applied, the air wiper pressure was 0.3 kg / cm ² , the liquid was drained, dried at 100 ° C. for 100 seconds, and then heat treated at 240 ° C. for 60 seconds.

  The obtained adhesive-treated cord has a solid content of 1.5 parts by weight with respect to 100 parts by weight of the synthetic fiber twisted cord in the first bath treatment liquid, and the second treatment liquid has a solid content of the synthetic fiber of 100% by weight. It was 1.0 weight part with respect to 100 weight part of twisted-yarn cords.

  Tables 1 and 2 show the characteristic evaluation results of the rubber reinforcing cords of Examples 1 and 2 and Comparative Example obtained as described above.

  As shown in Tables 1 and 2, in the case of Examples 1 to 10 according to the present invention, it can be seen that deterioration in rubber can be significantly improved as compared with the conventional polyester fibers for rubber reinforcement (Comparative Examples 1 to 10). .

Claims (9)

  A polyepoxide compound, a blocked polyisocyanate compound, a silicate compound, and an ethylenically unsaturated acid-modified styrene / butadiene rubber latex having a glass transition temperature (Tg) of 0 ° C. to 35 ° C. Adhesive treatment for rubber and fiber.   The adhesive treatment agent for rubber / fiber according to claim 1, wherein the ethylenically unsaturated acid-modified styrene-butadiene rubber latex has a dry latex film breaking elongation of 5% to 400%.   In the treatment agent, in addition to the ethylenically unsaturated acid-modified styrene / butadiene rubber latex, the treatment agent further contains another rubber latex, and is a total of the ethylenically unsaturated acid-modified styrene / butadiene rubber latex and the other rubber latex. The rubber / fiber bonding treatment according to claim 1 or 2, wherein the amount of the ethylenically unsaturated acid-modified styrene / butadiene rubber latex is 20 to 50 parts by weight (dry part by weight) based on 100 parts by weight. Agent.   In addition to (a) 40-50% by weight of conjugated diene monomer, (b) 13-20% by weight of vinylpyridine monomer, and (c) 25-35% by weight of styrene monomer. And a terpolymer rubber latex having a glass transition temperature (Tg) of -40 ° C to -10 ° C. Agent.   A synthetic fiber cord for reinforcing rubber, wherein the surface layer of the twisted cord of synthetic fiber is coated with the treatment agent according to any one of claims 1 to 4.   The surface layer of the cord is further coated with a treating agent containing a resorcin / formalin initial condensate and an ethylenically unsaturated acid-modified styrene / butadiene rubber latex having a glass transition temperature (Tg) of 0 ° C. to 35 ° C. 6. A synthetic fiber cord for reinforcing rubber according to claim 5.   The synthetic fiber cord for rubber reinforcement according to claim 5 or 6, wherein the synthetic fiber is a polyester fiber or an aromatic polyamide fiber.   A twisted yarn cord obtained by twisting a synthetic fiber is dried at 100 to 150 ° C and heat-treated at 200 to 245 ° C after the treatment agent according to any one of claims 1 to 4 is applied. A method for producing a synthetic fiber cord for rubber reinforcement.   In the method for producing the cord, the cord surface layer is subsequently treated with a treating agent containing a resorcin / formalin initial condensate and an ethylenically unsaturated acid-modified styrene / butadiene rubber latex having a glass transition temperature (Tg) of 0 ° C. to 35 ° C. The method for producing a synthetic fiber cord for reinforcing rubber according to claim 8, wherein the synthetic fiber cord is dried at 100 to 150 ° C. and heat-treated at 220 to 250 ° C.