JP2010053480A - Synthetic fiber for reinforcing rubber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a synthetic fiber for reinforcing rubber which can achieve excellent adhesion between the rubber and the synthetic fiber at high temperature. <P>SOLUTION: There is provided the synthetic fiber for reinforcing the rubber, to which a pretreatment agent comprising a blocked polyisocyanate, an epoxy resin and a rubber latex, and an adhesion treating agent based on a recorcinol-formalin-latex are applied, wherein the rubber latex is a soap-free acrylonitrile-butadiene latex. In addition, it is preferable that the adhesion treating agent contains a blocked polyisocyanate, and that the pretreatment agent contains a vinylpyridine-styrene-butadiene-terpolymer latex. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a synthetic fiber for rubber reinforcement, and more particularly to a synthetic fiber for rubber reinforcement excellent in heat-resistant adhesion at high temperatures.

  Polyester fibers typified by polyethylene terephthalate and polyethylene naphthalate fibers, and synthetic fibers such as aromatic polyamide fibers have excellent physical properties such as high strength and high Young's modulus. Widely used as a rubber reinforcing fiber for hoses and belts. However, since the surface of these synthetic fibers is relatively inactive, the adhesiveness with a matrix such as rubber or resin is insufficient as it is, and the physical properties of the fibers are fully exhibited. Absent.

  For this reason, a chemical treatment method for treating the surface of the fiber with various chemicals, for example, Patent Document 1, includes a compound containing a vinyl halide group having a film formation temperature of 200 ° C. or less, a polyepoxide compound, and / or one bath. A treatment agent containing a blocked polyisocyanate compound, which is treated with a treatment agent (1) in which the content of the compound containing a vinyl halide group is in the range of 3 to 85% by weight relative to the solid content of the treatment agent. Subsequently, a two-bath treatment method for polyester fibers for rubber reinforcement, characterized by further treatment with a treatment agent (2) containing resorcin, formalin, and rubber latex is disclosed. This method can dramatically reduce the adhesion amount of the adhesive and is economically excellent.

However, this treatment method has a problem that the peel adhesiveness at high temperature is insufficient, and the treatment method cannot be used in severe applications.
JP 2000-234275 A

  The present invention has been made against the background of the above circumstances, and is to provide a synthetic fiber for rubber reinforcement capable of realizing excellent adhesion between rubber and synthetic fibers at high temperatures.

  The synthetic fiber for reinforcing rubber of the present invention is a synthetic fiber for reinforcing rubber, to which a pretreatment agent containing block polyisocyanate, epoxy and rubber latex, and a resorcin / formalin / latex adhesive treatment agent are adhered, The latex is a soap-free acrylonitrile-butadiene latex.

  Furthermore, the adhesive treatment agent preferably contains a block polyisocyanate, and the pretreatment agent preferably contains a vinyl pyridine / styrene / butadiene / terpolymer latex. It is also preferable that the epoxy component is a polyglycidyl ether of any one of sorbitol, glycerin, and ethylene glycol, and the synthetic fiber is a polyester fiber.

  ADVANTAGE OF THE INVENTION According to this invention, the synthetic fiber for rubber reinforcement which can implement | achieve the adhesion | attachment excellent in rubber | gum and synthetic fiber at high temperature is provided.

  Examples of the rubber reinforcing synthetic fiber of the present invention include polyester fiber and aromatic polyamide fiber. More specifically, for example, as a polyester fiber, a fiber made of polyester having terephthalic acid or naphthalenedicarboxylic acid as a main acid component and ethylene glycol, 1,3-propanediol, or tetramethylene glycol as a main glycol component is used. Preferably used. Representative examples of the aromatic polyamide fiber include polyparaaminobenzamide, polyparaphenylene terephthalamide, polyparaaminobenzhydrazide terephthalamide, polyterephthalic acid hydrazide, polymetaphenylene isophthalamide, and copolymers thereof. Can be mentioned.

  The synthetic fiber of the present invention includes various fiber aggregate forms such as yarns, cords, nonwoven fabrics, woven and knitted fabrics, and in particular, cords with twisted yarns exhibit the strength of the synthetic fibers more effectively. It is preferable for this purpose. There are no particular limitations on synthetic fiber denier, filament count, cross-sectional shape, fiber properties, microstructure, polymer properties (terminal carboxyl group concentration, molecular weight, etc.), presence or absence of additives in the polymer, etc. In order to make effective use of strength, it is preferable to have a circular cross-sectional shape.

  The synthetic fiber for rubber reinforcement of the present invention is a synthetic fiber for rubber reinforcement in which a pretreatment agent containing block polyisocyanate, epoxy and rubber latex and an adhesion treatment agent of resorcin / formalin / latex are attached. At this time, it is essential that the rubber latex in the pretreatment agent is soap-free acrylonitrile-butadiene latex.

  The blocked polyisocyanate used in the present invention is a blocked polyisocyanate compound which is generally an addition reaction product of a polyisocyanate compound and a blocking agent. It gives rise to compounds. Examples of the polyisocyanate compound include polyisocyanates such as tolylene diisocyanate, metaphenylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, polymethylene polyphenyl isocyanate, and triphenylmethane triisocyanate. The blocked polyisocyanate compound used in the present invention is one in which the polyisocyanate as described above is blocked by a compound having one or more active hydrogen atoms. As a compound having one or more active hydrogen atoms, For example, phenols such as phenol, thiophenol, cresol and resorcinol, aromatic secondary amines such as diphenylamine and xylidine, lactams such as phthalimide, caprolactam and valerolactam, acetoxime, methylethylketoxime, cyclohexanone oxime, etc. Examples include oximes and acidic sodium sulfite.

  Further, the pretreatment agent of the present invention is required to contain an epoxy, and the epoxy here is a polyepoxide compound, and in particular, at least 2 epoxy groups in 1 molecule are equivalent to 2 g equivalent per kg of the compound. A compound containing the above is preferable. Specific examples of epoxies include reaction products of polyhydric alcohols such as ethylene glycol, glycerol, sorbitol, pentaerythritol, and polyethylene glycol with halogen-containing epoxides such as epichlorohydrin, resorcin, bis (4-hydroxyphenyl) Reaction products of polyhydric phenols such as dimethylmethane, phenol-formaldehyde resin, resorcinol-formaldehyde resin and the above halogen-containing epoxides, polyepoxide compounds obtained by oxidizing unsaturated compounds with peracetic acid or hydrogen peroxide, 3,4-epoxycyclohexylene epoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylenecarboxylate, bis (3,4-epoxy-6-methyl-cyclohexylmethyl) a Or the like can be mentioned Bate. Of these, reaction products of polyhydric alcohols such as ethylene glycol, glycerol, sorbitol, pentaerythritol, and polyethylene glycol and epichlorohydrin, that is, polyglycidyl ether compounds of polyhydric alcohols are preferable because they exhibit excellent performance.

  In the present invention, it is essential that the pretreatment agent contains soap-free acrylonitrile-butadiene latex. Here, soap-free means that a low molecular weight surfactant is not used as a method of dispersing in a solvent, and includes not only the case where no emulsifier is used, but also latex using a high molecular weight surfactant. To do. Among them, soap-free acrylonitrile rubber latex suitable for mass production is Nipol SX, manufactured by Nippon Zeon Co., Ltd., which is emulsion-polymerized using an oligomer-type acrylic alkali-soluble resin instead of the usual low molecular weight surfactant. You can list the series.

  Commonly used low molecular weight surfactants adsorb on the surface of a hydrophobic substance and work to increase the polarity of the surface. For this reason, the reaction and adhesion at the interface are affected, and in products such as the present invention in which the adhesion between fibers and rubber is essential, there is often a negative effect. The latex used in the present invention is emulsified by improving the polymer polarity without containing such a low molecular weight surfactant, and does not inhibit adhesion.

  In the present invention, the soap-free latex needs to be acrylonitrile-butadiene latex. Acrylonitrile butadiene rubber has little deterioration in physical properties at high temperatures, and in the improvement of adhesiveness when exposed to high temperatures, which is the object of the present invention, there is little deterioration in physical properties of the adhesive film, minimizing the decrease in adhesion between fibers and rubber. It is working. Moreover, the interaction with various polar groups is good due to the polarity of the nitrile group, and the adhesiveness in the initial state also has a good performance. Thus, by being soap-free and acrylonitrile butadiene latex, high adhesiveness can be exhibited in any state from the initial stage to the high temperature exposure.

  In addition to the acrylonitrile-butadiene latex as described above, the latex component in the pretreatment agent includes vinylpyridine-styrene-butadiene terpolymer latex, natural rubber latex, styrene-butadiene copolymer latex, chlorobrene rubber latex, ethylene It is also preferable to use propylene / diene monomer latex in combination. In particular, when high adhesion performance is required, it is optimal to use a vinylpyridine / styrene / butadiene terpolymer latex in combination. However, when used in combination, the ratio of the acrylonitrile-butadiene latex is preferably 20% by weight or more of the total latex components in the pretreatment agent, and the optimum range is 20 to 50% by weight. is there. When the amount of the soap-free acrylonitrile-butadiene latex is too small, the adhesiveness at high temperature tends to decrease. On the other hand, if it is too high, the compatibility of the adherend with rubber tends to decrease, and the initial adhesion tends to decrease.

  In general, the pretreatment agent attached to the surface of the synthetic fiber in the present invention is processed into a synthetic fiber as a solution. At this time, when the solution of the pretreatment agent contains the blocked polyisocyanate compound (A), the polyepoxide compound (B), and the rubber latex (L) as described above, the polyepoxide compound (B ), Blocked polyisocyanate compound (A), and rubber latex (L) with respect to the blending weight ratio of each component, (A) / (B) is 5/5 to 1/9, (L) / {(A) It is preferable to use such that + (B)} is 1/100 to 10/1, more preferably 1/5 to 1/2. In particular, by setting (A) / (B) in the range of 5/5 to 1/9, the adhesiveness at high temperature is further improved.

  In addition, by setting the (L) / {(A) + (B)} to 1/100 or more, the treated fiber can be kept flexible, and the fatigue resistance is reduced due to the cord becoming hard. Adhesiveness improves by preventing co-vulcanization with the latex of the adhesive agent and the rubber | gum which are to be adhered while preventing. On the other hand, when this ratio becomes too high, for example, (L) / {(A) + (B)} exceeds 10/1, the physical properties of the adhesive film at high temperature are lowered, and the adhesiveness at high temperature is lowered. It becomes a trend.

  In order to attach such a solution of the pretreatment agent to the synthetic fiber, means such as contact with a roller, application by spraying from a nozzle, or immersion in a solution can be employed. Further, the solid content adhesion amount to the synthetic fiber is exemplified by a range of 1 to 30% by weight, and preferably 2 to 15% by weight. In order to control the amount of solids adhering to the synthetic fiber, 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. It may be attached once.

  The synthetic fiber for rubber reinforcement of the present invention has a resorcin / formalin / latex adhesive treatment agent attached to the surface in addition to the pretreatment agent containing block polyisocyanate, epoxy and rubber latex as described above. is there.

  Examples of the latex component used herein include vinylpyridine / styrene / butadiene terpolymer latex, natural rubber latex, styrene / butadiene copolymer latex, chlorobrene rubber latex, ethylene / propylene / diene monomer latex, and the like. More preferably, soap-free acrylonitrile / butadiene latex is used in combination. Most preferably, soap-free acrylonitrile / butadiene latex and vinylpyridine / styrene / butadiene terpolymer latex are used in combination. When used in combination, the proportion of acrylonitrile-butadiene latex is preferably 20 to 50% by weight of the total latex components in the adhesive treatment agent. When the amount of the soap-free acrylonitrile-butadiene latex is too small, the adhesiveness at high temperature tends to decrease. On the other hand, if it is too high, the compatibility of the adherend with rubber tends to decrease, and the initial adhesion tends to decrease.

  The adhesive of the present invention is preferably applied to the synthetic fiber as a solution, but the resorcin / formalin / rubber latex (RFL) adhesive solution used at that time has a molar ratio of resorcin to formaldehyde of 1: Those in the range of 0.8 to 1: 5 are preferable, and more preferably in the range of 1: 1 to 1: 4. If the amount of formaldehyde added is too small, the crosslink density of the condensate of resorcin / formalin is lowered and the molecular weight is lowered, so that the adhesive strength may be lowered by reducing the cohesive force of the adhesive layer. If too much formaldehyde is added, the resorcin / formalin condensate becomes hard due to an increase in crosslink density, and the compatibility between the RFL and the rubber is inhibited during co-vulcanization with the adherend rubber, resulting in a decrease in adhesion and after treatment. There is a tendency that the fibers of the present invention are remarkably hard and the strength and fatigue properties are lowered.

  The adhesive treatment agent used in the present invention preferably contains a blocked polyisocyanate compound. The addition ratio of the blocked polyisocyanate compound to the adhesive treatment agent is within the range of 0.5 / 9.5 to 4/6 with respect to the total amount of resorcin / formalin / rubber latex (RFL). Those in the range of 3/7 are preferably used. If the added amount is too small, the effect of improving the adhesive strength is small, and if the added amount is too large, the viscosity of the adhesive is remarkably increased and the fiber processing operation becomes difficult, and the treated fiber becomes extremely hard, It is not preferable because strength and fatigue tend to decrease.

  The optimum blending ratio of resorcin / formalin and rubber latex in the solution of the adhesive treatment agent varies depending on the addition ratio of the blocked polyisocyanate compound. However, in the solid content ratio, resorcin / formalin: rubber latex (RFL). ) Is preferably in the range of 1: 3 to 1:12, particularly preferably in the range of 1: 3 to 1: 6. If the ratio of the rubber latex is too small, the treated polyester fiber tends to be hard and fatigue resistance tends to decrease, and co-vulcanization with the latex in the pretreatment solution and the rubber as the adherend is difficult. Insufficient adhesion may result. On the contrary, when the ratio of the rubber latex in the adhesive is too large, the strength as an adhesive film is reduced, and the adhesive force and the rubber adhesion rate tend to be reduced.

  The solution to be treated as the adhesion treating agent of the present invention is preferably in the range of 1 to 30% by weight, more preferably 2 to 25% by weight, further preferably 5 to 20% by weight as the total solid content concentration. % Can be used. When the total solid concentration of the adhesive treatment solution is lower than the above range, the surface tension of the adhesive solution increases, the uniform adhesion to the polyester fiber surface decreases, and the solid adhesion amount decreases. When the total solid content concentration is higher than the above range, on the contrary, the solid content is excessively increased, and the hardness becomes hard and the fatigue resistance tends to decrease.

  Moreover, in order to adhere such a solution of the adhesion treatment agent to the synthetic fiber, 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 synthetic fiber is exemplified by a range of 0.1 to 10% by weight, preferably a range of 0.2 to 7% by weight, and more preferably 0.5 to 6% by weight. The thing in the range of is good. In order to control the amount of solids adhering to the synthetic fiber, as described above, it can be performed by means of squeezing with a pressure roller, scraping with a scrubber, etc., blowing off with air blowing, suction, beater means, and the amount of adhesion is large. In order to do so, it may be attached multiple times.

  In order to obtain the synthetic fiber for rubber reinforcement of the present invention, the synthetic fiber is treated using the pretreatment agent solution and the adhesive solution as described above, and then the melting point of the synthetic fiber is 10 or more at 50 ° C. or higher. Dry and heat-treat in a temperature range lower than ℃. More preferably, for example, when the fiber is a polyester fiber, drying and heat treatment are performed at a temperature range of 220 to 250 ° C. for 0.5 to 5 minutes, preferably 1 to 3 minutes. If the 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 synthetic fiber melts and melts, resulting in a decrease in fiber strength. There is.

  The synthetic fiber for reinforcing rubber of the present invention thus obtained is excellent in heat resistance, and as a synthetic fiber for reinforcing rubber for tires, hoses, belts, etc., maintains high performance even in a particularly severe state. Are preferably used.

  Hereinafter, the present invention will be described in more detail with reference to examples. In addition, the characteristic in an Example was performed with the following measuring method.

(1) Cord peeling adhesive force I
It shows the adhesive strength between the treatment cord and rubber. The cords are arranged at 30 / 2.54 cm (1 inch) and sandwiched between uncured rubber sheets containing a carcass composed mainly of 0.5 mm thick natural rubber. These sheets were stacked so as to be orthogonal, and at a temperature of 150 ° C. for 30 minutes, a pressing pressure of 50 kg / cm ² (initial value), or at a temperature of 180 ° C. for 40 minutes, a pressing pressure of 50 kg / cm ² ( Vulcanized at a heat resistance value, and then cut into strips along the cord direction. In an atmosphere at room temperature of 25 ° C., the force required to peel the sheet along the strip in the direction of 90 degrees with respect to the rubber sheet surface at a speed of 200 mm / min is N / 2.54 cm (1 inch). It is shown.

(2) Cord peeling adhesion at high temperature I
The sample prepared for measuring the initial adhesive strength was measured under the same measurement conditions as above, except that the measurement ambient temperature was changed to 150 ° C., and the cord peeling adhesive strength I at high temperature was obtained.

(3) Cord peel adhesion II
It shows the adhesive strength between the treatment cord and rubber. 7 cords are buried near the surface layer of an unvulcanized rubber sheet composed of natural rubber as a main component and carcass is mixed, and at a temperature of 150 ° C. for 30 minutes, a pressing pressure of 50 kg / cm ² (initial value) or 180 ° C. Vulcanization was performed at a pressing pressure (heat resistance value) of 50 kg / cm ² for 40 minutes at a temperature. The force required to peel at a speed of 200 mm / min in the direction of the degree is indicated by N / 3.

(4) Adhesive strength of cord peeling at high temperature II
The sample prepared for measuring the initial adhesive strength was measured under the same measurement conditions as above, except that only the measurement ambient temperature was changed to 150 ° C., and the cord peeling adhesive strength II at high temperature was obtained.

[Example 1]
A sorbitol-based polyepoxide compound (SR-SEP manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.), ε-caprolactam blocked MDI (manufactured by Meisei Chemical Co., Ltd. S3), and soap-free acrylonitrile butadiene rubber latex (SX1503 manufactured by Nippon Zeon Co., Ltd.) A compounded liquid having a total solid content of 10% by weight mixed at a solid content of 80% by weight, 10% by weight, and 10% by weight was obtained (pretreatment agent (1)).

  An initial condensate having a resorcin / formalin (R / F) molar ratio of 1 / 0.6 and a solid concentration of 65% by weight is dissolved under alkaline conditions to obtain a 9% by weight aqueous solution. To this, 99 parts by weight and 104 parts by weight of 41% vinylpyridine / styrene / butadiene terpolymer latex (Pyratex manufactured by Nippon A & L Co., Ltd.) and water are added to 57 parts by weight of the 9% resorcin / formalin aqueous solution, respectively. To this solution was added 3 parts by weight of formalin and 30 parts by weight of a 33% by weight acetoxime blocked diphenylmethane diisocyanate dispersion (DM 6011 manufactured by Meisei Chemical Industry Co., Ltd.), and aged for 48 hours. An agent was obtained (adhesive treatment agent (1)).

  A multi-filament yarn of 1670 dtex / 384 filament made of polyethylene terephthalate with an intrinsic viscosity of 0.95 is used. The multi-filament yarn is subjected to a lower twist at 40 T / 10 cm, and two of these are twisted together to give an upper twist at 40 T / cm. And a synthetic fiber cord of 3340 dtex / 768 filament was obtained.

  The cord was immersed in the pretreatment agent (1) using a contributor treatment machine (CA Ritzler Co., Ltd., tire cord treatment machine), dried at a temperature of 130 ° C. for 2 minutes, and subsequently 240 ° C. Then, after being immersed in the adhesive treatment agent (1), it was dried at a temperature of 170 ° C. for 2 minutes, and subsequently subjected to a heat treatment at a temperature of 240 ° C. for 1 minute. The resulting tire cord had 2.1% by weight of the pretreatment agent (1) and 2.2% by weight of the adhesion treatment agent (1) as the solid content of the treatment agent. The obtained treated cord was embedded in an unvulcanized rubber containing carcass containing natural rubber as a main component, and evaluated by the methods of cord peel adhesion I after vulcanization and cord peel adhesion I at high temperature. The results are shown in Table 1.

[Example 2]
Instead of the pretreatment agent (1) of Example 1, a sorbitol polyepoxide compound (SR-SEP manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.), ε caprolactam blocked MDI (S3 manufactured by Meisei Chemical Co., Ltd.), soap-free acrylonitrile butadiene Each of rubber latex (SX1503 manufactured by Nippon Zeon Co., Ltd.) and vinylpyridine / styrene / butadiene terpolymer latex (Pyratex manufactured by Nippon A & L Co., Ltd.) in solid content is 70% by weight, 10% by weight, 10% by weight, 10% by weight. %, The same procedure as in Example 1 was performed except that a mixed solution (pretreatment agent (2)) having a total solid content of 10% by weight was mixed. The results are also shown in Table 1.

[Comparative Example 1]
In the pretreatment agent (1) of Example 1, in place of the soap-free acrylonitrile / butadiene rubber latex, a pretreatment agent (3) using an acrylonitrile / butadiene rubber latex containing a surfactant (Nipol 1562 manufactured by Nippon Zeon Co., Ltd.) ) Was carried out in the same manner as in Example 1. The results are also shown in Table 1.

[Comparative Example 2]
In the pretreatment agent (1) of Example 1, a pretreatment agent (4) using soap-free styrene-butadiene rubber latex (SX1105 manufactured by Nippon Zeon Co., Ltd.) was used instead of soap-free acrylonitrile-butadiene rubber latex. Except for this, the same procedure as in Example 1 was performed. The results are also shown in Table 1.

[Example 3]
A sorbitol-based polyepoxide compound (EX611 manufactured by Nagase ChemteX Corporation), ε caprolactam blocked MDI (S3 manufactured by Meisei Chemical Co., Ltd.), vinylpyridine / styrene / butadiene terpolymer latex (Pyratex manufactured by Nippon A & L Co., Ltd.), and Soap-free acrylonitrile butadiene rubber latex (SX1503, manufactured by Nippon Zeon Co., Ltd.) was mixed at a solid content of 10% by weight, 10% by weight, 50% by weight and 30% by weight, respectively, and the total solid content was 5% by weight. A liquid was obtained (pretreatment agent (5)).

  An initial condensate having a resorcin / formalin (R / F) molar ratio of 1 / 0.6 and a solid concentration of 65% by weight is dissolved under alkaline conditions to obtain a 9% by weight aqueous solution. To this, 41 parts by weight and 488 parts by weight of 41% vinylpyridine / styrene / butadiene terpolymer latex (Pyratex, manufactured by Nippon A & L Co., Ltd.) and water are added to 57 parts by weight of the 9% resorcin / formalin aqueous solution, respectively. Formalin 3 parts by weight, 40% by weight cresol novolak type aromatic epoxy compound dispersion (ECN1400 manufactured by Asahi Ciba Co., Ltd.) 24 parts by weight, 33% by weight acetoxime blocked diphenylmethane diisocyanate dispersion (Meisei Chemical Industries) DM6011) 12 parts by weight was added, and an RFL adhesive having a solid content concentration of 20% by weight aged for 48 hours was obtained (adhesive treatment agent (2)).

  A multi-filament yarn of 1670 dtex / 384 filament made of polyethylene terephthalate with an intrinsic viscosity of 0.95 is used. The multi-filament yarn is subjected to a lower twist at 40 T / 10 cm, and two of these are twisted together to give an upper twist at 40 T / cm. And a synthetic fiber cord of 3340 dtex / 768 filament was obtained.

  The cord was immersed in the pretreatment agent (5) using a contributor processing machine (CA Ritzler Co., Ltd., tire cord processing machine), dried at a temperature of 130 ° C. for 2 minutes, and subsequently 240 Heat treatment was performed at a temperature of 1 ° C. for 1 minute, followed by immersion in the adhesive treatment agent (2), followed by drying at a temperature of 170 ° C. for 2 minutes, followed by heat treatment at a temperature of 240 ° C. for 1 minute. . The resulting tire cord had 2.1% by weight of the pretreatment agent (5) and 2.2% by weight of the adhesion treatment agent (2) as the solid content of the treatment agent. The obtained treated cord was embedded in an unvulcanized rubber containing carcass containing natural rubber as a main component, and evaluated by the methods of cord peeling adhesion II after vulcanization and cord peeling adhesion II at high temperature. The results are shown in Table 2.

[Example 4]
Instead of the pretreatment agent (5) of Example 3, a sorbitol-based polyepoxide compound (EX611 manufactured by Nagase ChemteX Corporation), ε caprolactam blocked MDI (S3 manufactured by Meisei Chemical Industry Co., Ltd.), vinylpyridine / styrene / butadiene terter Polymer latex (Pyratex manufactured by Nippon A & L Co., Ltd.) and soap-free acrylonitrile butadiene rubber latex (SX1503 manufactured by Nippon Zeon Co., Ltd.) are each 60% by weight, 20% by weight, 10% by weight, 10% by weight. This was carried out in the same manner as in Example 3 except that a blended liquid (pretreatment agent (6)) having a total solid content of 10% by weight mixed at a ratio of The results are also shown in Table 2.

[Example 5]
Instead of the adhesion treating agent (2) of Example 3, an initial condensate having a resorcin / formalin (R / F) molar ratio of 1 / 0.6 and a solid content concentration of 65% by weight was dissolved under alkaline conditions to give 9%. A 41% vinyl pyridine styrene butadiene terpolymer latex (Pyratex manufactured by Nippon A & L Co., Ltd.), soap-free acrylonitrile butadiene rubber latex (SX1503 manufactured by Nippon Zeon Co., Ltd.) and water and the above 9% resorcin 99 parts by weight, 52 parts by weight and 48 parts by weight are added to 57 parts by weight of the formalin aqueous solution, respectively. Formalin 3 parts by weight, 40% by weight cresol novolak type aromatic epoxy compound dispersion (ECN1400 manufactured by Asahi Ciba Co., Ltd.) 24 parts by weight, 33% by weight acetoxime blocked diphenylmethane diisocyanate dispersion (Meisei Chemical Industries) The same procedure as in Example 3 was performed except that 12 parts by weight of DM6011 manufactured by Co., Ltd. was added and an RFL adhesive (adhesive treatment (3)) having a solid content concentration of 20% by weight that was aged for 48 hours was used. The results are also shown in Table 2.

[Comparative Example 3]
In the pretreatment agent (5) of Example 3, a sorbitol-based polyepoxide compound (EX611 manufactured by Nagase ChemteX Corporation), ε caprolactam blocked MDI (S3 manufactured by Meisei Chemical Industry Co., Ltd.), and vinylpyridine / styrene / butadiene terpolymer Each of latex (Pyratex manufactured by Nippon A & L Co., Ltd.) was mixed at a ratio of 10% by weight, 10% by weight, and 80% by weight of a solid content, and a total liquid content of 5% by weight (pretreatment agent (7) ) Was used in the same manner as in Example 3. The results are also shown in Table 2.

Claims (5)

  A synthetic fiber for reinforcing rubber to which a pre-treatment agent containing block polyisocyanate, epoxy and rubber latex and an adhesion treatment agent of resorcin / formalin / latex are attached, and the rubber latex is soap-free acrylonitrile / butadiene latex A synthetic fiber for reinforcing rubber characterized by the above.   The synthetic fiber for rubber reinforcement according to claim 1, wherein the adhesive treatment agent contains a blocked polyisocyanate.   The synthetic fiber for reinforcing rubber according to claim 1 or 2, wherein the pretreatment agent contains vinylpyridine, styrene, butadiene, terpolymer latex.   The synthetic fiber for reinforcing rubber according to any one of claims 1 to 3, wherein the epoxy component is a polyglycidyl ether of any one of sorbitol, glycerin and ethylene glycol.   The synthetic fiber for rubber reinforcement according to any one of claims 1 to 4, wherein the synthetic fiber is a polyester fiber.