JP2012154005A - Rubber-reinforcing fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide rubber-reinforcing fibers which maintain high adhesion to rubber even after being exposed to high temperatures.SOLUTION: The rubber-reinforcing fibers include a surface treatment agent which contains a perchlorate ion-type layered double hydroxide and is adhered to the fiber surfaces. Furthermore, it is preferable that the layered double hydroxide contains divalent and trivalent metals, that the surface treatment agent contains a resorcin-formalin-latex-based adhesive (RFL adhesive) or contains an epoxy compound, and that at least part of the fibers are polyester fibers. It is also preferable that the layered double hydroxide contains at least one divalent metal selected from the group consisting of Mg, Mn, Fe, Co, Ni, Cuand Zn, and that the layered double hydroxide contains at least one trivalent metal selected from the group consisting of Al, Fe, Cr, Coand In.

Description

  The present invention relates to a rubber reinforcing fiber, and more particularly to a rubber reinforcing fiber that is suitably used for a rubber fiber composite and has excellent adhesion after being exposed to a high temperature for a long time.

  The fibers have excellent physical properties such as high strength and high Young's modulus, and are used as rubber reinforcing fibers for tires, hoses, belts, and the like that make use of this. However, the surface of these fibers is often relatively inactive, and as such, the adhesiveness with a matrix such as rubber or resin is insufficient, and the physical properties of the fibers cannot be fully exhibited. Absent.

  For this reason, after the surface of the fiber is treated with various chemicals, for example, after treatment with a highly reactive chemical such as an aliphatic epoxy compound, ethylene urea, or a blocked isocyanate compound, the adhesion is imparted. A so-called two-bath treatment method using resorcin / formalin / rubber latex (RFL) has been proposed and put into practical use (for example, Patent Document 1). However, this traditional treatment method has insufficient peel adhesion at a high temperature of 100 ° C. or higher, and cannot be used in applications where demands are severe.

  On the other hand, Patent Document 2 discloses a technique for improving adhesiveness at a high temperature by using a chlorophenol compound having good compatibility with a polymer constituting a fiber as a carrier. However, when the chlorophenol compound is simply used, there is a problem that the condensation of the chlorophenol compound occurs and the surface film made of the treatment agent becomes hard. As a result, the flexibility of the processing cord was lowered, which caused the adhesiveness and fatigue to deteriorate.

  As another method, a method of suppressing the permeation of amine by adding a component having low substance permeability to the adhesive layer has been devised. For example, Patent Document 3 proposes a prescription in which polyvinyl chloride is added to one bath agent. However, this method has a problem that when the adhesive amount is small, the cord hardness is low and fatigue characteristics and the like are good, but the resistance to aminolysis is not yet sufficient, and the durability at high temperature is poor. there were.

JP-A-54-73994 JP 2006-322083 A JP 2000-234275 A

  The present invention has been made against the background of the above circumstances, and it is an object of the present invention to provide a rubber reinforcing fiber that maintains high adhesion between rubber and fiber even after being exposed to a high temperature.

The rubber reinforcing fiber of the present invention is characterized in that a surface treatment agent containing a perchlorate ion type layered double hydroxide is adhered to the fiber surface.
Further, the layered double hydroxide contains a divalent metal and a trivalent metal, or the surface treatment agent contains a resorcin / formalin / latex adhesive (RFL adhesive) or It is preferable that the surface treatment agent contains an epoxy compound and that at least a part of the fiber is a polyester fiber.

The layered double hydroxide contains at least one divalent metal selected from the group consisting of Mg ²⁺ , Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , Cu ²⁺ and Zn ^2+. The layered double hydroxide preferably contains at least one trivalent metal selected from the group consisting of Al ³⁺ , Fe ³⁺ , Cr ³⁺ , Co ³⁺ and In ³⁺ .

  ADVANTAGE OF THE INVENTION According to this invention, the fiber for rubber reinforcement which maintains the high adhesiveness of rubber | gum and fiber even after exposed to high temperature is provided.

  Although there is no restriction | limiting in particular as a fiber used for this invention, It uses especially preferable for synthetic fibers, such as a polyester fiber and an aromatic polyamide fiber. Especially this invention is effective with respect to a polyester fiber, and it is preferable that a polyester fiber is contained in at least one part with respect to all the fibers. Here, as the 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 preferably used. The denier of the fiber, the number of filaments, the cross-sectional shape, the fiber properties, the fine structure, the polymer properties (terminal carboxyl group concentration, molecular weight, etc.), the presence or absence of additives in the polymer, and the like are not limited at all.

  The form of the fiber subjected to the treatment of the present invention includes various fiber aggregate forms such as yarn, cord, non-woven fabric, woven or knitted fabric, and in particular, the cord has a twisted yarn, and the strength of the fiber Is preferable in order to exhibit more effectively.

And the fiber for rubber reinforcement of this invention makes it essential that the surface treating agent containing the perchlorate ion type layered double hydroxide adheres to the surface of the fiber. Here, the layered double hydroxide has a layered structure in which the main skeleton is composed of a double hydroxide, and is a mineral in which hydroxides of elements such as magnesium, calcium, zinc, aluminum, bismuth and iron are crystallized. It is. Examples of the perchlorate ion type layered double hydroxide used in the present invention include hydrotalcite compounds represented by the following general formula (1).
^{_{[M 2+ 1-x M 3+}} x (OH) 2] x + [ClO 4 - · mH 2 O] x (1)
( ^Wherein M ²⁺ is a divalent metal ion such as Mg, Mn, Fe, Co, Ni, Cu and Zn, and M ³⁺ is a trivalent metal ion such as Al, Fe, Cr, Co and In. And x is in the range of 0 <x ≦ 0.33 and m is in the range of 0 ≦ m.)

As described above, the layered double hydroxide contains at least one divalent metal selected from the group consisting of Mg ²⁺ , Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , Cu ²⁺ , and Zn ^2+. Or at least one trivalent metal selected from the group consisting of Al ³⁺ , Fe ³⁺ , Cr ³⁺ , Co ³⁺ , and In ³⁺ is preferable. In particular, the divalent metal is preferably magnesium and the trivalent metal is preferably aluminum because of its stability. Further, natural or synthetic hydrotalcite is preferable, but in the present invention, perchlorate ions must be contained as interlayer anions.

  In the perchlorate ion type layered double hydroxide used in the present invention, perchlorate ions are incorporated into the layer structure of the metal ion hydroxide sheet having a layered structure. This perchlorate ion reacts only with molecules of a size that can enter the layer, and exhibits an effect. That is, it is considered that the perchlorate in the layered double hydroxide selectively oxidizes and decomposes only harmful organic substances that induce adhesion deterioration. When a general mere perchlorate compound is added to the surface treatment agent, the other active ingredients in the surface treatment agent are also decomposed, so that the adhesive force is reduced and the rubber reinforcement of the present invention is reduced. An effect like a fiber cannot be exhibited.

  The surface treatment agent containing a perchlorate ion type layered double hydroxide used in the present invention is not particularly limited, and contains a resorcin / formalin / latex adhesive (RFL adhesive). It is preferable that it is what to do or contains an epoxy compound.

  In addition, the content of the perchlorate ion type layered double hydroxide in these surface treatment agents ranges from 0.01 wt% to 5 wt% with respect to the solid component weight of other adhesives and the like. More preferably, it is preferably in the range of 0.03 wt% to 3 wt%. When the amount of the layered double hydroxide added is too low, the adsorption and resolution of harmful organic substances such as amines are lowered, and it is difficult to obtain a sufficient performance improvement effect. On the other hand, when the added amount is too large, the dispersion state of other adhesives and the like deteriorates, and it tends to be difficult to process and the adhesive performance also decreases.

  Further, the surface treatment agent used in the present invention will be described in detail. In the surface treatment agent used as a treatment solution for so-called one-bath adhesion treatment for rubber and fiber or a treatment solution for the second bath of two-bath adhesion treatment, -It is preferable to contain a formalin latex adhesive (RFL adhesive) with a perchlorate ion type layered double hydroxide. In the surface treatment agent used as the first bath treatment liquid in the two-bath adhesion treatment, the epoxy compound is contained together with the perchlorate ion type layered double hydroxide in the surface treatment agent not containing the RFL adhesive. It is preferable that Furthermore, it is preferable to contain a layered double hydroxide in both the surface treatment agent of the first bath containing no RFL adhesive and the second bath containing the RFL adhesive.

  When the surface treatment agent for the first bath of the two-bath adhesion treatment contains a perchlorate ion type layered double hydroxide, it is preferable that the pretreatment liquid as the surface treatment agent contains an epoxy compound. Furthermore, it is preferable to contain an isocyanate compound and / or a rubber latex.

  As the epoxy compound that is preferably used, a compound containing at least 2 g equivalent or more of epoxy group in 1 molecule per 1 kg of the compound is preferable. Specifically, reaction products of polyhydric alcohols such as ethylene glycol, glycerol, sorbitol, pentaerythritol, polyethylene glycol and halogen-containing epoxides such as epichlorohydrin, resorcin, pis (4-hydroxyphenyl) dimethylmethane, phenol -Reaction products of polyhydric phenols such as formaldehyde resin, resorcinol-formaldehyde resin, and the above halogen-containing epoxides, polyepoxide compounds obtained by oxidizing unsaturated compounds with peracetic acid or hydrogen peroxide, ie 3, 4 -Epoxycyclohexene epoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylene carboxylate, bis (3,4-epoxy-6-methyl-cyclohexylmethyl) adipate, etc. Rukoto can. Among these, a reaction product of a polyhydric alcohol and epichlorohydrin, that is, a polyglycidyl ether compound of a polyhydric alcohol is preferable because it exhibits excellent performance.

  Similarly, the isocyanate compound preferably used is preferably a blocked polyisocyanate compound in which an isocyanate group is blocked. This blocked polyisocyanate compound is an addition compound of a polyisocyanate compound and a blocking agent, and releases a block component by heating to produce an active polyisocyanate compound.

  More specifically, as the polyisocyanate compound, for example, polyisocyanate such as tolylene diisocyanate, metaphenylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, polymethylene polyphenyl isocyanate, triphenylmethane triisocyanate, or these polyisocyanates and A terminal isocyanate group obtained by reacting a compound having two or more active hydrogen atoms, such as trimethylolpropane, pentaerythritol, etc., at a molar ratio of isocyanate group (—NCO) to hydroxyl group (—OH) exceeding 1. Examples thereof include polyol adduct polyisocyanate. In particular, aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate and polymethylene polyphenyl isocyanate are preferable because they exhibit excellent performance.

  Examples of the blocking agent for the blocked polyisocyanate compound include phenols such as phenol, thiophenol, cresol, and resorcinol, aromatic secondary amines such as diphenylamine and xylidine, phthalimides, caprolactam, and valerolactam. Examples include lactams, acetoximes, oximes such as methyl ethyl ketone oxime, cyclohexane oxime, and acidic sodium sulfite.

  Furthermore, it is preferable to contain a rubber latex in addition to the polyepoxide compound and / or the blocked isocyanate compound in the pretreatment liquid for the surface treatment agent in the first bath of the two-bath adhesion treatment. The presence of the rubber latex causes co-vulcanization with the rubber as the adherend, and this is confirmed, for example, from the fact that high rubber is achieved during the peel test.

  Examples of the rubber latex preferably used include natural rubber latex, styrene / butadiene rubber latex, vinylpyridine / styrene / butadiene copolymer latex, acrylonitrile / butadiene rubber latex, and chloroprene rubber latex. Use in combination. Among them, it is preferable to use vinylpyridine / styrene / butadiene copolymer latex alone or in combination. In the case of combined use, particularly excellent performance is exhibited when it is used in an amount of 1/3 or more of the total latex weight including polyvinyl chloride latex.

  Such a surface treatment agent can be used as a pretreatment liquid in which each component is usually blended in the composition as an emulsion, an aqueous dispersion, or an aqueous solution. In order to make the agent component into an emulsified liquid or an aqueous dispersion, for example, the compound 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, What is necessary is just to emulsify or disperse | distribute using a nonylphenol ethylene oxide adduct etc.

  When the matrix component of the surface treatment agent used in the present invention is used as an aqueous dispersion, the appropriate amount of the dispersant, that is, the surfactant, is 0 to 15 wt%, preferably It is 10 wt% or less, and when it exceeds the above range, the adhesiveness tends to decrease. The addition of a surface tension reducing agent such as alkylene glycol or water-soluble silicone is also effective, and these additions improve the wettability during processing, thereby improving the performance when processed at a low concentration.

  Moreover, in order to adhere such a surface treating agent to a 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 to the rubber reinforcing fiber is preferably in the range of 0.1 to 3% by weight. In order to control the amount of solids adhering to the fiber, it can be done by means of squeezing with a pressure roller, scraping with a scrubber, etc., blowing off with air blowing, suction, means of beater, and the amount of adhesion increases. For this purpose, it may be attached a plurality of times.

  In the present invention, when a surface treatment agent containing a perchlorate ion type layered double hydroxide is used in a treatment solution for a one-bath adhesion treatment or a treatment solution for a second bath of a two-bath adhesion treatment, The agent preferably contains a resorcin / formalin / latex adhesive (RFL adhesive).

  As the resorcin / formalin / rubber latex (RFL) which is an adhesive component preferably used for the surface treatment agent, a resorcin / formaldehyde molar ratio in the range of 1: 0.8 to 1: 5 is preferably used. More preferably, it is used 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. Therefore, the adhesive strength may be lowered by reducing the cohesive force of the adhesive layer. If the amount of addition is too large, the resorcin / formalin condensate becomes hard due to an increase in the crosslinking density, and compatibilization of the RFL with the rubber is inhibited during co-vulcanization with the adherend rubber, resulting in a decrease in adhesion and after treatment. There is a tendency for the fiber to become extremely hard and to have a problem of reduced strength and fatigue.

  The blending ratio of resorcin / formalin and rubber latex in the adhesive is preferably a solid content ratio of resorcin / formalin: rubber latex (RFL) in the range of 1: 3 to 1:20. In particular, those in the range of 1: 5 to 1:15 are preferably used. If the ratio of the rubber latex is too small, the treated polyester fiber becomes hard and the fatigue resistance tends to decrease, and the co-vulcanization with the rubber as the adherend becomes insufficient, and the adhesion may be lowered. On the contrary, if the ratio of rubber latex is too large, sufficient strength as an adhesive film cannot be obtained, so that not only satisfactory adhesive strength and rubber adhesion rate may not be obtained, but also the processing code Of the dip treatment process and dirt in the product manufacturing process tend to be caused.

  It is also preferable to use a cross-linking agent in combination with the surface treatment agent containing the resorcin / formalin / latex (RFL) adhesive. Examples of the crosslinking agent to be preferably added include amines, ethylene urea, blocked polyisocyanate compounds, etc., but in view of the stability of the treatment agent over time, the interaction with the pretreatment agent in the first bath, etc. A polyisocyanate compound is preferably used.

  The addition rate of a crosslinking agent such as a blocked polyisocyanate compound in this surface treatment agent is 0.5 to 40% by weight, preferably 10 to 30% by weight, based on resorcin / formalin / rubber latex (RFL). Some are preferred. Increasing the amount added usually improves the adhesion, but conversely if the amount added is too large, the compatibility of the surface treatment agent with the rubber decreases, the adhesion with the rubber decreases, and the fibers after treatment Tends to be extremely hard, and the strength and fatigue tend to decrease.

  The total solid concentration before application of the surface treatment agent containing the RFL adhesive to the fibers is preferably in the range of 1 to 30% by weight. When the total solid content concentration of the surface treatment agent before application is lower than the above range, the surface tension of the treatment agent increases, the uniform adhesion to the fiber surface decreases, and the solid content adhesion amount decreases. In contrast, if the total solid content concentration is higher than the above range, the viscosity of the treatment agent becomes high, so that the solid content is too much, and the dip treatment process In addition to causing contamination in the manufacturing process of products and products, the processing cords become hard and the fatigue resistance tends to decrease.

  In order to adhere this surface treatment agent to the 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 to the fiber is preferably in the range of 0.1 to 10% by weight, more preferably in the range of 1.0 to 5.0% by weight. In order to control the amount of solids adhering to the fiber, it can be done by means of squeezing with a pressure roller, scraping with a scrubber, etc., blowing off with air blowing, suction, means of beater, and the amount of adhesion increases. For this purpose, it may be attached a plurality of times.

  Furthermore, in the rubber reinforcing fiber of the present invention, the surface treatment agent preferably contains a polyvinyl chloride latex. By adding polyvinyl chloride latex to the surface treatment agent, it is possible to impart the ability to prevent the permeability of amine, and it is possible to further enhance the effect of the present invention. Aminolysis that occurs when the amine present in the rubber passes through the adhesive layer is further suppressed, preventing a decrease in adhesion that occurs after the rubber / fiber composite is exposed to high temperatures, and also exhibits sufficient performance in terms of initial adhesion. It becomes possible to do.

  The rubber reinforcing fiber of the present invention can be obtained by heating and drying a fiber to which the above surface treatment agent is attached. Heating and drying are preferably performed at a temperature of 50 ° C. or higher and 10 ° C. or lower than the melting point of the fiber. More preferably, it is dried and heat-treated in a temperature range of 220 to 270 ° C. for 0.5 to 5 minutes, and more preferably for 1 to 3 minutes. In general, 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 fibers tend to melt and melt, leading to a decrease in strength. is there.

  Such a rubber reinforcing fiber of the present invention is excellent in heat resistance, and is preferably used as a rubber reinforcing fiber for tires, hoses, belts, etc., maintaining high performance even at high temperatures.

  The mechanism by which the rubber reinforcing fiber of the present invention exhibits a preferable effect is not clear. However, the perchlorate ion type layered double hydroxide, which is an essential component in the present invention, has perchlorate ions incorporated into the layer structure of the metal ion hydroxide sheet having a layered structure, The perchlorate ion reacts only with molecules that can enter the layer. And other components such as other adhesives in the surface treatment agent do not enter the layer, and only the amines that degrade the adhesion are captured and decomposed in the layer, resulting in an effect of improving durability. it is conceivable that.

  In particular, when a fiber reinforced rubber is left for a long time in a state exposed to a high temperature, an adhesive interface (especially an amine compound) contained in the rubber deteriorates the adhesive interface, and a mechanism that lowers the adhesion is considered. When the rubber reinforcing fiber of the present invention is used, the perchlorate in the layered double hydroxide oxidizes and decomposes organic matter, and particularly amines with high reducing ability are easily captured and decomposed. Excellent durability.

  The present invention will be further described in the following examples. Various characteristics were measured by the following methods.

(1) Initial peel adhesive strength This indicates 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 are stacked so as to be orthogonal, vulcanized at a temperature of 150 ° C. for 30 minutes at a pressing pressure of 50 kg / cm ² , and then cut into strips along the cord direction. The force required to peel off the sheet along the strip of the prepared sample at a speed of 200 mm / min in the direction of 90 degrees with respect to the rubber sheet surface is shown by N / 2.54 cm (1 inch). . This initial peel adhesive strength was measured at room temperature.

(2) Heat-resistant adhesive strength A sample was prepared in the same manner as the peel-off adhesive strength in (1) except that vulcanization conditions were performed at 180 ° C. for 40 minutes (heat-resistant conditions), and the peel adhesive strength was measured at room temperature. The heat-resistant adhesive strength was used.

[Example 1]
Polyepoxide compound having a sorbitol polyglycidyl ether structure (Denacol EX-614B, manufactured by Nagase ChemteX Corporation), methylethylketoxime block, blocked polyisocyanate having a dimethyldiphenyl diisocyanate structure (DM-6400, manufactured by Meisei Chemical Industry Co., Ltd.), vinylpyridine Styrene-butadiene rubber latex (Nippol 2518FS manufactured by Nippon Zeon Co., Ltd.), PVC latex (VYCar 460X104 manufactured by Nihon Lubrizol Co., Ltd.) and hydrotalcite which is a perchlorate ion type layered double hydroxide (Kyowa Chemical Industry Co., Ltd.) Manufactured by Alkamizer 5, magnesium aluminum hydroxyperchlorate hydrotalcite) in solid content of 6.0 parts by weight, 4 parts by weight, 45 parts by weight, 45 The amount unit, were mixed at a ratio of 0.1 parts by weight, and a total solids concentration of 10.0 wt%. The obtained compounded liquid was used as the pretreatment liquid for the first bath treatment (surface treatment 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. 99% by weight and 87% by weight of 41% vinylpyridine / styrene / butadiene turbolimer latex (Pyratex, manufactured by Nippon A & L Co., Ltd.) and water are added to 57% by weight of the 9% resorcin / formalin aqueous solution, respectively. To this solution was added 3 parts by weight of formalin, 30 parts by weight of 33 wt% acetoxime blocked diphenylmethane diisocyanate dispersion (DM 6011 manufactured by Meisei Chemical Industry Co., Ltd.), and aged for 48 hours. An adhesion treatment liquid for bath treatment was obtained (surface 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. To obtain a cord of 3340 dtex / 768 filament.
The cord was immersed in the surface treatment agent (1) using a contributor processing machine (tire code processing machine manufactured by CA Ritzler Co., Ltd.), then dried at a temperature of 130 ° C. for 2 minutes, and then 240 1 minute heat treatment is performed at a temperature of 0 ° C., followed by drying for 2 minutes at a temperature of 170 ° C. after immersion in the surface treatment agent (2), followed by a heat treatment of 1 minute at a temperature of 240 ° C. It was. The resulting tire cord had 1.4% by weight of the agent derived from the surface treating agent (1) and 2.5% by weight of the agent derived from the surface treating agent (2) as the solid content of the treating agent. . The obtained treated cord was embedded in an unvulcanized rubber containing carcass containing natural rubber as a main component and evaluated by the above method after vulcanization. The results are shown in Table 1.

[Examples 2 and 3]
The amount of hydrotalcite, which is a perchlorate ion type layered double hydroxide, in the surface treatment agent (1) of Example 1 is changed from 0.1 parts by weight (Example 1, agent (1)) to 1 The same treatment as in Example 1 was performed except that the content was changed to 0.0 parts by weight (Example 2, agent (1 ′)) and 0.05 parts by weight (Example 3, agent (1 ″)). The evaluation results are also shown in Table 1.

[Example 4]
Total solids, which is a composition obtained by removing hydrotalcite, which is a perchlorate ion type layered double hydroxide, from the pretreatment liquid for the first bath treatment (surface treatment agent (1)) used in Example 1 A pretreatment liquid (surface treatment agent (3)) for the first bath treatment having a partial concentration of 10.0% by weight was prepared.
Next, perchlorate ion type layered double water was used for the second bath treatment adhesive treatment liquid (surface treatment agent (2)) having a solid content concentration of 20% by weight which was aged for 48 hours, which was also used in Example 1. Hydrotalcite (produced by Kyowa Chemical Industry Co., Ltd., Alkamizer 5), which is an oxide, was added to a solid content ratio of 0.1% by weight, and an adhesion treatment liquid (surface treatment agent (surface treatment agent ( 4)) was obtained.
Instead of the surface treatment agent (1) of Example 1, the surface treatment agent (3) was used as the pretreatment liquid for the first bath treatment, and the surface treatment agent (4) was used instead of the surface treatment agent (2) of Example 1. ) Was used as the adhesion treatment liquid for the second bath treatment, and the same treatment as in Example 1 was performed. The evaluation results are shown in Table 2.

[Examples 5 and 6]
The addition amount of hydrotalcite, which is a perchlorate ion type layered double hydroxide, in the surface treatment agent (4) of Example 4 is from 0.1 part by weight (Example 4, agent (4)) to 1 The same treatment as in Example 4 was performed, except that the amount was changed to 0.0 parts by weight (Example 5, agent (4 ′)) and 0.05 parts by weight (Example 6, agent (4 ″)). The evaluation results are also shown in Table 2.

[Comparative Example 1]
Hydrotall which is a perchlorate ion type layered double hydroxide used in Example 4 instead of the pretreatment liquid (surface treatment agent (1)) for the first bath treatment used in Example 1 The same adhesion treatment as in Example 1 was performed, except that a pretreatment liquid (surface treatment agent (3)) which was a composition with the site removed was used. The evaluation results are also shown in Table 1.

[Example 7]
In place of the polyethylene terephthalate fiber of Example 1, the same adhesion treatment as in Example 1 was performed except that polyethylene naphthalate fiber was used.
That is, as the fiber, a 1670 dtex / 384 filament multifilament yarn made of polyethylene naphthalate having an intrinsic viscosity of 0.76 is used, and the multifilament yarn is twisted at 35 T / 10 cm. A synthetic fiber cord of 3340 dtex / 768 filament was obtained by twisting at / cm.
The surface treatment agent (1) containing hydrotalcite, which is a perchlorate ion type layered double hydroxide, was processed by the same treatment as in Example 1 except that this agent was used. %, And 2.6% by weight of the surface treatment agent (2) was adhered. The evaluation results are shown in Table 3.

[Example 8]
In place of the polyethylene terephthalate fiber of Example 4, the same adhesion treatment as in Example 4 was performed except that the polyethylene naphthalate fiber used in Example 7 was used. The evaluation results are also shown in Table 3.

[Comparative Example 2]
Hydrotall which is a perchlorate ion type layered double hydroxide used in Example 4 instead of the pretreatment liquid for the first bath treatment (surface treatment agent (1)) used in Example 7 The polyethylene naphthalate fiber was subjected to the same adhesion treatment as in Example 7 except that the pretreatment liquid (surface treatment agent (3)), which was a composition with the site removed, was used. The evaluation results are also shown in Table 3.

[Comparative Example 3]
Instead of the perchlorate ion type layered double hydroxide in the pretreatment liquid (surface treatment agent (1)) for the first bath treatment of Example 1, the same amount of sodium perchlorate was added. A pretreatment liquid (surface treatment agent (5)) having the same composition was obtained.
However, this pretreatment liquid (surface treatment agent (5)) gelled and could not be processed into fibers.

[Comparative Example 4]
Instead of the perchlorate ion type layered double hydroxide in the adhesion treatment liquid (surface treatment agent (4)) for the second bath treatment of Example 4, the same amount of sodium perchlorate was added. The adhesion treatment liquid (surface treatment agent (6)) having the same composition was obtained.
However, this adhesion treatment liquid (surface treatment agent (6)) was gelled and could not be processed into fibers.

[Comparative Example 5]
Instead of the perchlorate ion type layered double hydroxide (counter ion is ClO ₄ ⁻ ) in the pretreatment liquid (surface treatment agent (1)) for the first bath treatment of Example 1, the counter ion is CO 2. ₃ is a ^2-synthetic hydrotalcite (Kyowa chemical industry Co., Ltd., DHT-4) except that was added in the same amount, to obtain a pretreatment liquid of the same formulation (surface treatment agent (7)). The same treatment as in Example 1 was performed except that the surface treatment agent (1) was changed to this surface treatment agent (7) as a pretreatment liquid. The evaluation results are shown in Table 4.

[Comparative Example 6]
Instead of the perchlorate ion type layered double hydroxide (counter ion is ClO ₄ ⁻ ) in the adhesion treatment liquid (surface treatment agent (4)) for the second bath treatment of Example 4, the counter ion is CO 2. ₃ ² a is synthetic hydrotalcite (Kyowa chemical industry Co., Ltd., DHT-4) except that the added the same amount, to obtain an adhesive treating solution of the same formulation (surface treatment agent (8)). The same treatment as in Example 4 was performed except that the surface treatment agent (4) was changed to this surface treatment agent (8) as the adhesion treatment liquid. The evaluation results are also shown in Table 4.

Claims (7)

  A fiber for reinforcing rubber, wherein a surface treatment agent containing a perchlorate ion type layered double hydroxide is adhered to the fiber surface.   The rubber reinforcing fiber according to claim 1, wherein the layered double hydroxide contains a divalent metal and a trivalent metal.   The rubber reinforcing fiber according to claim 1 or 2, wherein the surface treatment agent contains a resorcin / formalin / latex adhesive (RFL adhesive).   The fiber for rubber reinforcement according to any one of claims 1 to 3, wherein the surface treatment agent contains an epoxy compound. 2. The layered double hydroxide contains at least one divalent metal selected from the group consisting of Mg ²⁺ , Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , Cu ²⁺ and Zn ^2+. The fiber for rubber reinforcement according to any one of -4. The layered double hydroxide contains at least one trivalent metal selected from the group consisting of Al ³⁺ , Fe ³⁺ , Cr ³⁺ , Co ³⁺ , and In ^3+. The rubber reinforcing fiber according to item.   The fiber for rubber reinforcement according to any one of claims 1 to 6, wherein at least a part of the fiber is a polyester fiber.