KR20000022468A - Treatment for rubber-reinforcing fibers, reinforcing fibers, and reinforced rubbers - Google Patents

Abstract

PURPOSE: A reinforcing fiber for a rubber product is provided to have excellent heat resistance, water resistance and resistance to flex fatigue without undergoing a complicated production process and a treatment agent. CONSTITUTION: A rubber-reinforcing fiber treatment agent comprises a rubber latex, a resorcin-formaldehyde water-soluble condensate, triazine thiol and oxidizing agent. The rubber-reinforcing fiber treatment agent contains 50-95wt% of the rubber latex, 2 -25wt% of the resorcin-formaldehyde water-soluble condensate, 0.5-20wt% of triazine thiol and 0-10wt% of the oxidizing agent as solid contents, based on the total weight of all the solid contents.

Description

Textile treatment agent for rubber reinforcement, fiber and rubber reinforcement products for reinforcement

As reinforcing materials for rubber products such as rubber belts, tires and the like, reinforcing fibers such as glass fibers, polyester fibers, polyamide fibers and the like are widely used.

Since rubber products such as rubber belts are repeatedly subjected to bending stress, their performance deteriorates due to bending fatigue, so that the reinforcing fibers can be separated or worn out from the rubber matrix, and as a result, their strength is likely to be low. This phenomenon tends to be particularly promoted by heat and moisture. In order to prevent such separation due to bending fatigue and to obtain a sufficient reinforcing effect, the adhesion and drape of the reinforcing fibers and rubber should be increased, and heat resistance and water resistance should be provided to the reinforcing fibers. For this purpose, various treatment agents are coated on the surface of the reinforcing fibers.

JP-A 1-221433 is a treatment agent comprising a combination of resorcin-formaldehyde water soluble condensate, vinylpyridine-butadiene-styrene trimer latex, dicarboxylated butadiene-styrene copolymer latex and chlorosulfonated polyethylene latex Various treatments are proposed.

The use of the treatment agent, although reinforcing to some extent the adhesion between the reinforcing fibers and the rubber matrix, the heat resistance and the flex resistance of the treatment agent itself, is not satisfactory. Therefore, when a reinforcing fiber treated with the treatment agent is used, a rubber product having excellent heat resistance, water resistance and flex fatigue resistance is difficult to be obtained.

To reinforce the adhesion between the reinforcing fibers and the rubber matrix, JP-B 5-71710 also contains a second layer containing halogen-containing polymers and isocyanates for reinforcing containing resorcin-formaldehyde water-soluble condensates and latexes. A rubber-reinforcing fiber formed by laminating on a first layer formed on a fiber and additional laminating a third layer containing the same rubber as the matrix rubber on the second layer is proposed. However, this type of rubber reinforcing fiber manufacturing method is complicated and uneconomical since a second and third layer forming step is required following the first layer forming step.

Disclosure of the Invention

It is a first object of the present invention to solve the problems of the prior art, and to provide a treatment agent for reinforcing fibers which can provide a reinforced rubber product having excellent heat resistance, water resistance and flex fatigue resistance without complicated manufacturing processes.

A second object of the present invention is to provide the reinforcing fibers treated with the fiber treatment agent of the present invention.

It is a third object of the present invention to provide a reinforcement product reinforced with the reinforcing fibers of the present invention.

Other objects and advantages of the present invention will become apparent from the following detailed description.

First, according to the present invention, the objects and advantages of the present invention can be achieved by a rubber reinforcing fiber treatment agent containing rubber latex, resorcin-formaldehyde water soluble condensate and triazine thiol.

Secondly, according to the present invention, the above can provide a reinforcing fiber treated with the fiber treatment agent of the present invention, and third, can provide a rubber reinforcing product reinforced with the rubber reinforcing fiber of the present invention.

The present invention is described in detail below.

(Fiber reinforcing agent for rubber reinforcement)

Rubber latex which is one of the components of the rubber reinforcing fiber treatment agent of the present invention, butadiene-styrene copolymer latex, decarboxylated butadiene-styrene copolymer latex, vinylpyridine-butadiene-styrene trimer latex, fluoroprene latex, butadiene Rubber latex, chlorosulfonated polyethylene latex, acrylonitrile-butadiene copolymer latex, nitrile group-containing high saturated copolymer rubber latex and the like can be preferably used. The latex can be used alone or as a mixture of two or more. As the rubber latex contained in the rubber reinforcing fiber treatment agent, a preferable result can often be obtained by selecting a latex of the same or similar rubber as the kind of the reinforced rubber. Particularly preferable results can be obtained by applying a fiber treating agent containing a nitrile group-containing high saturated copolymer rubber latex to a fiber for reinforcing a rubber blend containing a nitrile group-containing high saturated copolymer rubber.

As butadiene-styrene copolymer rubber latex, it is particularly suitable to use a copolymer prepared by copolymerizing butadiene and styrene in a weight ratio of 60:40 to 90:10, for example. Preferred examples of such latex are JSR 2108 (trade name, Japan Synthetic Rubber Co., Ltd.), BASTAL S60 (Baystal S60; trade name, Bayer AG), J9040 (trade name, Sumika ABS Latex Co., Ltd.), Nipole LX110 (Nipol LX110; trade name, Nippon Zeon Co., Ltd.) and the like.

As the dicarboxylated butadiene-styrene copolymer latex, a copolymer containing, for example, 20 to 80 wt% butadiene, 5 to 70 wt% styrene and 1 to 10 wt% ethylenically unsaturated dicarboxylic acid is particularly suitable. . Preferred examples of the latex include Nipol 2570X5 (trade name, Nippon Zeon Co., Ltd.) JSR 0668 (trade name, Japan Synthetic Rubber Co., Ltd.) and the like.

As the vinylpyridine-butadiene-styrene trimer latex, for example, many of the above trimers known to those skilled in the art can be used. For example, trimers containing vinylpyridine, butadiene and styrene in a weight ratio of 10:80:10 to 20:60:20 are particularly suitable. Preferred examples of such trimers are Nipol 2518FS (trade name, Nippon Zeon Co., Ltd.), JSR 0650 (trade name, Japan Synthetic Rubber Co., Ltd.), Pyratex (trade name, Sumika ABS Latex Co., Ltd.). .) And the like.

As chlorosulfonated polyethylene latex, polymers having a chlorine content of 25 to 43 wt% and a sulfur content of 1.0 to 1.5 wt% are particularly suitable. Preferred examples of such trimers include CSM-450 (trade name, Sumitomo Seika Chemicals Co., Ltd.) and the like.

As the acrylonitrile-butadiene copolymer latex, copolymers containing 30 to 43% of bound acrylonitrile are particularly suitable. Preferred examples of such latexes include Nipol 1561 (trade name, Nippon Zeon Co., Ltd.) and the like.

The nitrile group-containing highly saturated polymer rubber latex preferably has an iodine valance of 120 or less in terms of the strength of the rubber film and the adhesive strength to the matrix rubber. Preferably, the iodine number is 0-100. The content of unsaturated nitrile units (amount of bound acrylonitrile) in the nitrile group-containing high saturated polymer rubber is preferably 10 to 60 wt% in terms of drape and adhesion to the matrix rubber. Examples of the nitrile group-containing high saturated polymer rubber include hydrides of butadiene-acrylonitrile copolymer rubber, isoprene-butadiene-acrylonitrile copolymer rubber and isoprene-acrylonitrile copolymer rubber; Butadiene-methylacrylate-acrylonitrile copolymer rubber, butadiene acrylic acid-acrylonitrile copolymer rubber and hydrides thereof; Butadiene-ethylene-acrylonitrile copolymer rubber, butyl acrylate-ethoxyethyl acrylate-vinyl chloroacetate-acrylonitrile copolymer rubber, butyl acrylate ethoxyethyl acrylate-vinylnorbornene-acrylonitrile aerial Coalescing rubber and the like. As the latex, "Zetpol Latex" (trade name, Nippon Zeon Co., Ltd.) can be preferably used. Iodine number is determined according to JIS K0070.

The second component of the rubber reinforcing fiber treatment agent of the present invention, resorcin-formaldehyde water-soluble condensate (hereinafter referred to as RF), is preferably used in combination with resorcin in the presence of an alkali catalyst such as alkali hydroxide or amine, for example. Resol type water-soluble addition condensate obtained by reacting formaldehyde, particularly preferably a reaction product obtained by reacting resorcin with formaldehyde in a molar ratio of 1: 0.5 to 3.

Examples of the triazine thiol which is the most characteristic component of the rubber reinforcing fiber treatment agent of the present invention are 1,3,5-triazine-2,4,6-tritriol, 6-amino-1,3,5-triazine -2,4-dithiol, 6-dibutylamino-1,3,5-triazine-2,4-dithiol and the like. Among these, 1,3,5-triazine-2,4,6-tritriol is preferable. Triazine thiols are ground to a particle size of 0.1 to 1.0 μm by a ball mill or the like and dispersed in a dispersion medium such as water at a concentration of 10 to 50 wt%, for example, before use. The dispersion medium used is not particularly limited, but other dispersion mediums such as alcohol may be used in addition to water.

As the oxidizing agent, organic peroxides, chloranyl, benzoquinone, resorcinol and the like can be used. Of these, chloranyl is particularly preferred.

In the present invention, the ratio of rubber latex, RF, triazine thiol and oxidizing agent is preferably 50 to 95 wt% (more preferably 65 to 85 wt%), 2 to 25 wt% (more preferably based on the ratio of solids content). Preferably 5 to 20 wt%), 0.5 to 20 wt% (more preferably 2 to 10 wt%) and 0 to 10 wt% (more preferably 0 to 5 wt%). To this, water is added as necessary, and the resulting mixture is uniformly mixed to prepare an aqueous treatment solution. When the solids content of the triazine thiol contained in the rubber reinforcing fiber treatment agent of the present invention thus obtained is outside the above range, no improvement in heat resistance, water resistance and flex fatigue resistance is observed, and the effects of the present invention are not sufficiently obtained. Do not. The effect of the present invention is still obtained even if no oxidizing agent is added, but heat resistance, water resistance and flex fatigue resistance are further improved when added. In this case, if the ratio of the oxidant is out of the above, the effect remains unchanged. If the ratio of RF is too large, the reinforcing fiber is cured by curing the coating film of the treatment agent of the present invention, and sufficient bending fatigue resistance is hardly obtained. If the ratio of RF is too small, sufficient adhesion to the rubber matrix is difficult to be obtained.

The solids content of the aqueous treatment agent of the present invention is 10 to 40 wt%, preferably 20 to 30 wt%. If the solids content is too small, the adhesion to the reinforcing fibers becomes insufficient, while if the solids content is too large, it becomes difficult to control the adhesion amount on the reinforcing fibers, thereby obtaining a rubber reinforcing fiber having a uniform amount of adhesion. it's difficult.

Although the treating agent of the present invention contains the rubber latex, RF and triazine thiol as essential components, it may also contain a substrate, such as ammonia for adjusting its pH, in addition to the oxidizing agent, and additionally sulfur, stabilizer, oxidation An inhibitor etc. can be added as needed.

(Fiber Reinforcement Fiber)

Fibers for the rubber reinforcing fibers useful in the present invention are not particularly limited. Specific examples of the fibers include glass fibers; Polyvinyl alcohol fibers typified by vinylon fibers; Polyester fibers; Polyamide fibers such as nylon and aramid (aromatic polyamide); Carbon fiber; Polyparaphenylene benzoxazole fibers and the like. Among these, glass fiber and aramid fiber are particularly preferable. The fibers can also be in various forms, embodiments of which include staples, filaments, cords, ropes, canvases, and the like. Glass compositions of the glass fibers are not limited, such as E-glass, high strength glass, and the like. The filament diameter of the glass fiber is not particularly limited and is generally 5 to 13 mu m. Aramid fibers of 500 to 5,000 denier are generally used.

(Processing of Fiber for Rubber Reinforcement)

The method for treating the fibers is not particularly limited in the present invention. Before the fiber is treated with the treating agent of the present invention, depending on the type of fiber, it may be suitably treated with an epoxy, polyisocyanate or silane coupling agent. An example is as follows.

The glass fiber strands as fibers are immersed in the treatment agent of the present invention, the excess treatment agent is removed, and the strands are heated at 200 to 300 ° C. for 0.5 to 3 minutes as necessary to attach the treatment agent on the surface of the glass fiber strands. At this time, the glass fiber strand may or may not be treated with a binding agent during spinning. The desired number of glass fiber strands is tied and twisted in a conventional manner to obtain a rubber reinforcing fiber (cord). This rubber reinforcing fiber was buried in an unvulcanized rubber matrix according to a known method, and vulcanized by heating the unvulcanized rubber matrix at 120 to 180 ° C. under pressure for 1 to 120 minutes.

In the process, the treating agent of the present invention is coated on the fiber in an amount of 10 to 30 wt% as a solid content, based on the weight of the fiber treated with the fiber treating agent. The type of rubber to be reinforced with the rubber reinforcing fiber treated with the treatment agent of the present invention is not particularly limited, and various types of rubbers such as chloroprene rubber, chlorosulfonated polyethylene rubber, nitrile group-containing high saturated copolymer rubber, and the like can be used. have. In particular, when a nitrile group-containing high unsaturated copolymer rubber is used, very desirable results can be obtained. When the rubber reinforcing fiber cord coated with the treatment agent of the present invention is buried in the rubber to be vulcanized, an additive may be added to the rubber, for example, a vulcanizing agent, a vulcanizing accelerator, a pigment, a fat and oil and a stabilizer may be added according to the purpose. Can be. The content of the rubber reinforcing fiber in the rubber product obtained after vulcanization and molding is determined depending on the type of the rubber product, but is generally 10 to 70 wt%, preferably 20 to 40 wt%.

The rubber product obtained by the present invention is excellent in heat resistance, water resistance and flex fatigue resistance. Thus, the rubber reinforcing fibers treated with the fiber treating agent of the present invention can advantageously be used as reinforcing fibers for rubber reinforcing products such as automatic tie-man belts that perform flexural tensioning in environments affected by heat and moisture. have.

The following examples are intended to further illustrate the invention. In the examples below, "parts" and "%" are by weight unless otherwise noted.

The present invention relates to a rubber reinforcing fiber treatment agent, reinforcing fibers and rubber reinforcing products. More specifically, the present invention is used to reinforce rubber products, such as rubber belts, tires, etc., the treatment agent for the rubber reinforcing fibers excellent in adhesion, heat resistance, flex resistance and water resistance; Rubber reinforcing fibers coated with the treatment agent; And a rubber reinforcement product reinforced with the reinforcing fiber.

(Manufacture of rubber blends)

A rubber blend was prepared according to the formulation shown in Table 1. In the table, "Jetpol 2020" is a nitrile group-containing highly saturated copolymer rubber (trade name, Nippom Zeon Co., Ltd.) having an iodine of 28 and having 36% of bound acrylonitrile.

combination part Jetpole 2020 100.0 Zinc white No.1 5.0 Stearic acid 1.0 Trioctyl Trimellitate 10.0 SRF carbon 60.0 4,4- (α, α-dimethylbenzyl) diphenylamine 1.5 Mercaptobenzothiazole zinc salt 1.5 Tetramethylthiuram disulfide 1.5 sulfur 0.5 Cyclohexylbenzothiazyl sulfenamide 1.0

(Preparation of RF Solution)

RF solutions were prepared according to the formulations shown in Table 2.

Resorcin 7.8 parts Formalin (37%) 6.9 parts Sodium hydroxide aqueous solution (10%) 2.0 parts water 115.2 parts

(Production of Treatment)

Seven treatments from A to G were prepared using the RF solutions shown in Table 2 according to the formulations shown in Table 3 (the following units of each treatment are "parts"). In the table, "Nipole 2518FS" is vinylpyridine-butadiene-styrene trimer latex (Nippon Zeon Co., Ltd .; solid content 40%) and "CSM-450" is chlorosulfonated polyethylene rubber latex (Sumitomo Seika Chemicals Co ., Ltd .; Solid content 40%), "Jetpole latex" is a nitrile group-containing highly saturated copolymer rubber latex (Nippon Zeon Co., Ltd .; 28 iodines, 36% bonded acrylonitrile and 40 solids content) %) to be. The solids content of each treatment is 25 to 27 wt%.

Treatment A B C D E F G RF solution 35.0 35.0 35.0 30.0 35.0 35.0 30.0 Nepol 2518FS - - 10.0 45.0 - 10.0 45.0 CSM-450 - - - 20.0 - - 20.0 Jetpole Latex 60.0 60.0 50.0 - 60.0 50.0 - 1,3,5-triazine-2,4,6-tritriol 3.0 3.0 2.0 1.5 - - - Chloranil 1.0 - 1.0 0.8 - - - 25% ammonia water 1.0 1.0 1.0 1.0 1.0 1.0 1.0 water 4.0 4.0 4.0 4.0 4.0 4.0 4.0

(Product of treated fiber)

The treatment agent was treated with a non-alkali glass composition (SiO ₂ 64.4 wt%, Al ₂ O ₃ 25.0 wt%, CaO 0.3 wt%, MgO 10.0 wt%, B ₂ O ₃ 0.1 wt% and Na ₂ O + K ₂ O 0.2 wt% ) Was coated on a glass fiber strand (filament having a diameter of 9 µm, 101 tex (600 filament)) to have a solid content adhesion rate of about 19%. The coated glass fiber strands were heated at 280 ° C. for 1 minute and then twisted 2.1 times per inch in one direction to provide a glass fiber cord. Thereafter, the 11 strands were combined to twist 2.1 times per inch in the opposite direction to give a glass fiber cord.

Similarly, the treatment was coated on aramid fiber strands (Technora T202, Teijin Ltd., 1,500 d) to give an adhesion rate of solids content of about 12%. After the coated aramid strands were heated at 250 ° C. for 1 minute, the two strands were joined together to twist 3.1 times per inch to give an aramid fiber cord.

(Assessment Methods)

The treated cords thus obtained were arranged so as to have a length of 12 cm and a width of 25 mm on the sheet of the rubber blend, and vulcanized at a pressure of 5 MPa and 150 ° C. for 30 minutes to obtain an adhesive strength test piece. The peeling test was done about the obtained test piece and the initial stage adhesive force was measured. In addition, the content rate of the said processing cord in the said test piece was 30 wt%.

The peeling test after heat-treating the test piece similarly obtained at 120 degreeC for 168 hours in air was done, and the heat resistant adhesive force was measured. Similarly obtained test pieces were heated in water for 1 hour to measure their adhesion (water resistance). The results are shown in Tables 4 to 7 for each rubber latex component of the fiber treatment agent.

In addition, a toothed belt having a width of 19 mm and a length of 980 mm was prepared using a similarly obtained treated fiber cord and a nitrile group-containing high saturated copolymer rubber blend described in Table 1. This toothed belt was attached to the traveling test machine provided with the drive motor of 6000 rpm, and the heat-resistant running test was performed for 600 hours in 120 degreeC environment. Moreover, the toothed belt obtained similarly was attached to the water injection driving test machine provided with the drive motor of 6000 rpm, and the water injection running test of 24 hours was performed at room temperature. The tensile strength of the belt after the test of this heat-resistant running and water injection run was measured, respectively, and the ratio with respect to the tensile strength before a running test, ie, tensile strength retention (%), was calculated | required. The results are shown in Tables 4 to 7 as the tensile strength retention rates of the heat resistant run and the water injection run, respectively.

Example Comparative Example 1 One 2 Code type Fiberglass cord Fiberglass cord Treatment No. 1 A B E Adhesive force (kg / 25 ㎜) Initial heat resistance Water resistance 28.625.528.3 26.923.327.4 21.517.820.5 Tensile strength retention rate after running test (%) Heat-resistant running water injection run 86.476.0 80.574.7 72.565.8

Example 3 Comparative Example 2 Code types Fiberglass cord Fiberglass cord Treatment No. 1 C F Adhesive force (kg / 25 ㎜) Initial heat resistance Water resistance 27.421.526.6 16.712.514.8 Tensile strength retention rate after running test (%) Heat-resistant running water injection run 76.768.4 63.654.5

Example 4 Comparative Example 3 Code type Fiberglass cord Fiberglass cord Treatment No. 1 D G Adhesive force (kg / 25 ㎜) Initial heat resistance Water resistance 26.520.720.2 19.515.613.7 Tensile strength retention rate after running test (%) Heat-resistant running water injection run 73.366.5 58.741.3

Example 5 Comparative Example 4 Code types Aramid Fiber Cord Aramid Fiber Cord Treatment No. 1 A E Adhesive force (kg / 25 ㎜) Initial heat resistance Water resistance 15.013.510.5 8.54.56.0 Tensile strength retention rate after running test (%) Heat-resistant running water injection run 82.774.5 71.866.2

The rubber product reinforced with the rubber reinforcing fiber of the present invention is inexpensive, and excellent in heat resistance, water resistance and flex fatigue resistance, compared with the conventional treatment agent. The rubber reinforcing fibers of the present invention can very advantageously be used as reinforcing fibers for rubber reinforcing products such as toothed belts, belts such as V belts.

Claims (13)

A fiber treating agent for rubber reinforcement containing rubber latex, resorcin-formaldehyde water soluble condensate and triazine thiol. The fiber reinforcing agent for rubber reinforcement according to claim 1, comprising rubber latex, resorcin-formaldehyde water soluble condensate, triazine thiol and oxidizing agent. The rubber latex according to claim 1 or 2, based on the total weight of the solids content, 50 to 95 wt% of rubber latex, 2 to 25 wt% of resorcin-formaldehyde water-soluble condensate, 0.5 to 20 triazine thiol A fiber reinforcing agent for rubber reinforcement containing wt% and oxidant 0 to 10 wt%. The fiber treatment agent for rubber reinforcement according to any one of claims 1 to 3, wherein the triazine thiol is 1,3,5-triazine-2,4,6-tritriol. The fiber reinforcing agent for rubber reinforcement according to claim 2 or 3, wherein the oxidizing agent is chloranyl. The fiber reinforcing agent for rubber reinforcement according to any one of claims 1 to 3, wherein the rubber latex is a nitrile group-containing highly saturated copolymer rubber latex. 4. The rubber reinforcing fiber treatment agent according to claim 3, which contains 10 to 40 wt% of rubber latex, resorcin-formaldehyde water-soluble condensate, triazine thiol and oxidizing agent. A rubber reinforcing fiber treated with the fiber treating agent of any one of claims 1 to 7. 9. The rubber reinforcing fiber according to claim 8, wherein the fiber treating agent is coated on the fiber in an amount of 10 to 30 wt% as a solid content based on the weight of the fiber treated with the fiber treating agent. 10. The rubber reinforcing fiber according to claim 9, wherein the fiber is glass fiber or aramid fiber. A rubber reinforcement product reinforced with the rubber reinforcing fiber of any one of claims 8 to 10. The rubber reinforcing product according to claim 11, wherein the rubber reinforcing fiber is a nitrile group-containing high saturated copolymer rubber latex, and the rubber fiber is glass fiber or aramid fiber. The rubber reinforcing product according to claim 11 or 12, wherein the rubber reinforcing fiber is contained in an amount of 10 to 70 wt% based on the rubber reinforcing product.