JP2012067412A - Coating liquid for coating glass fiber and glass fiber for reinforcing rubber using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating liquid for coating a glass fiber which can impart durabilities such as heat resistance and water resistance in a balanced manner to a transmission belt and a conveyor belt comprising a chloroprene rubber as a base material and is formed by embedding a glass fiber for reinforcing rubber for reinforcement and impart a coating layer having excellent adhesiveness to a chloroprene rubber, and to provide a glass fiber for reinforcing rubber using the same.SOLUTION: There is provided a glass fiber for reinforcing rubber 3 that is embedded in a transmission belt comprising a chloroprene rubber 2 as a base material, and is formed by providing a coating layer containing a monohydroxybenzene-formaldehyde condensate (A), a vinylpyridine-styrene-butadiene copolymer (B), and a chloroprene rubber (C) on a strand composed of a plurality of glass fiber filaments bundled together.

Description

  The present invention relates to a glass fiber for reinforcing rubber for embedding as a core wire in a base material rubber when reinforcing a transmission belt or a conveyor belt.

  Specifically, when a coating layer is provided on a strand obtained by further combining glass fiber filaments and bundling with a bundling material to obtain a glass fiber for reinforcing rubber, a glass fiber coating coating solution for providing a coating layer and The present invention relates to a rubber reinforcing glass fiber used and a rubber transmission belt or conveyor belt in which the rubber reinforcing glass fiber is embedded as a core wire for reinforcement.

  In particular, a glass fiber coating coating solution for providing a coating layer on a glass fiber for reinforcing rubber embedded in a transmission belt or conveyor belt using chloroprene rubber as a base material, and a glass for reinforcing rubber using the same The present invention relates to a fiber transmission belt or a conveyor belt made of rubber, in which the glass fiber for rubber reinforcement is embedded as a core wire for reinforcement.

    In order to give tensile strength and dimensional stability to rubber products such as transmission belts and tires, rubber reinforcing fibers, which are cords made of high tensile strength fibers such as glass fibers, nylon fibers, aramid fibers, and polyester fibers, are used as mother materials. Embedding as a reinforcing material in rubber, which is a material, is generally performed, and a rubber reinforcing fiber embedded in a base rubber is required to have a strong interface with the base rubber and not peel off. However, a glass fiber cord in which a sizing agent containing a silane coupling agent and a resin or the like is dispersed and focused on a number of glass fiber filaments, in other words, even if the strand is embedded in the base rubber as it is, the interface peels off. Do not use as a reinforcing material. Therefore, the glass fiber cord is coated with a glass fiber coating coating solution to adhere to the base rubber on the glass fiber for rubber reinforcement that is embedded in the base rubber when using the transmission belt. Provide a layer.

  For example, a coating solution made of a resorcin-formaldehyde condensate and a latex has been used for a coating material such as a nylon cord as an automobile tire cord. Resorcin-formaldehyde condensates are highly reactive and provide excellent adhesion, and more than half of the total demand is the raw material for tire cord adhesives. Usually, a vinylpyridine-styrene-butadiene copolymer is used for the latex.

  However, the coating layer composed of the coating solution containing only the resorcin-formaldehyde condensate and the vinylpyridine-styrene-butadiene copolymer is sticky even when dried, and the quality of the rubber reinforcing fiber is not stable. Inferior workability when coated on rubber reinforcing fiber. Therefore, latexes such as chlorosulfonated polyethylene and acrylonitrile-butadiene copolymer have been added to the components of the coating layer.

  For example, Patent Document 1 discloses a rubber in which a layer containing a water-soluble condensate of resorcin formaldehyde, a vinylpyridine-styrene-butadiene copolymer latex and an acrylonitrile-butadiene copolymer latex is formed on a core made of glass fiber. A reinforcing fiber is disclosed.

    In addition, for the purpose of improving water resistance when used as a transmission belt, Patent Document 2 relating to the applicant's patent application includes monohydroxybenzene-formaldehyde condensate and vinylpyridine- for coating on a glass fiber cord. A coating solution for coating glass fiber is disclosed in which a styrene-butadiene copolymer and chlorosulfonated polyethylene are dispersed in water to form an emulsion. The glass fiber coating coating solution is particularly suitable for use in rubber reinforcing glass fibers embedded in a timing belt whose base material is hydrogenated nitrile rubber, and a primary coating layer is used for the glass fiber coating coating solution. In order to improve adhesion and durability, an organic diisocyanate compound, a bisallylnadiimide compound, a maleimide compound, a triazine compound, or the like is used for the secondary coating layer.

  Normal industrial transmission belts have excellent durability such as weather resistance, ozone resistance, heat aging resistance, chemical resistance, etc., oil resistance, flame resistance, performance balance, and ease of use. Rubber mainly composed of rubber (simply referred to as chloroprene rubber in the present invention) is widely used as a base material for transmission belts and conveyor belts.

JP-A-4-103634 JP 2006-104595 A

  As described above, the resorcin-formaldehyde condensate is highly reactive and has excellent adhesive strength. However, in the timing belt in which the base material is hydrogenated nitrile rubber, the hydrogen of the aromatic ring is converted into a hydroxy group from the resorcin-formaldehyde condensate obtained by reacting resorcin in which two hydrogens of the aromatic ring are substituted with hydroxy group with formaldehyde. Using a glass fiber for rubber reinforcement having a coating layer containing a monohydroxybenzene-formaldehyde condensate obtained by reacting one substituted monohydroxybenzene with formaldehyde is more resistant to heat and water when used as a timing belt. Excellent.

  The superior water resistance is due to the fact that the monohydroxybenzene-formaldehyde condensate is more hydrophobic than the resorcin-formaldehyde condensate.

  For the purpose of improving heat resistance and water resistance, monohydroxybenzene-formaldehyde is formed by applying a glass fiber coating coating solution described in Patent Document 2 to a strand formed by applying a bundling material onto a glass fiber filament and bundling it, and then drying. An attempt was made to embed a glass fiber for rubber reinforcement provided with a coating layer containing a condensate, a vinylpyridine-styrene-butadiene copolymer and chlorosulfonated polyethylene in a transmission belt or conveyor belt based on chloroprene rubber. However, the adhesive strength between the glass fiber for reinforcing rubber and the chloroprene rubber was so weak that it could not be put into practical use.

  The present invention provides a power transmission belt comprising a chloroprene rubber as a base material and embedded glass fibers for reinforcement for reinforcement, a conveyor belt with good balance of durability such as heat resistance and water resistance, and adhesion to chloroprene rubber. An object of the present invention is to provide a glass fiber coating coating solution that provides a coating layer excellent in the thickness and a glass fiber for rubber reinforcement using the same.

    As a result of intensive studies by the present inventors in order to solve the above-described problems, the sizing is performed after applying a sizing agent containing a silane coupling agent and a resin to a plurality of glass fiber filaments, specifically a large number of glass fiber filaments. A coating obtained by coating and coating a glass fiber coating coating solution containing a monohydroxybenzene-formaldehyde condensate (A), a vinylpyridine-styrene-butadiene copolymer (B), and a chloroprene rubber (C) on the strands thus formed. It was found that the glass fiber for reinforcing rubber provided with the layer has excellent adhesion with the base material chloroprene rubber.

  The coating solution for coating glass fiber contains monohydroxybenzene-formaldehyde condensate (A) to form a coating layer of glass fiber for reinforcing rubber, so that the glass fiber for reinforcing rubber is embedded in chloroprene rubber. The heat resistance and water resistance of the transmission belt and conveyor belt are improved.

  A power transmission belt and a conveyor belt in which a glass fiber for rubber reinforcement is embedded by adding a vinylpyridine-styrene-butadiene copolymer (B) to the glass fiber coating liquid and forming a coating layer of the glass fiber for rubber reinforcement. The mechanical durability is maintained.

  By including chloroprene rubber (C) in the glass fiber coating liquid to form a coating layer of glass fiber for rubber reinforcement, an adhesive force between the glass fiber for rubber reinforcement and chloroprene rubber as a base material is developed.

  That is, the present invention is a glass fiber coating coating solution for providing a coating layer on a glass fiber for rubber reinforcement embedded in a transmission belt having chloroprene rubber as a base material, and the monohydroxybenzene-formaldehyde condensate (A) It is a coating solution for glass fiber coating, comprising a vinylpyridine-styrene-butadiene copolymer (B) and a chloroprene rubber (C).

  Further, in the coating solution for covering glass fibers of the present invention, the composition ratio of monohydroxybenzene-formaldehyde condensate (A), vinylpyridine-styrene-butadiene copolymer (B), and chloroprene rubber (C), which are contained By adjusting the above, it was possible to obtain a favorable adhesive force for the glass fiber for rubber reinforcement and the chloroprene rubber as the base material, and to have a good balance between heat resistance and water resistance.

  Furthermore, the present invention represents the mass percentage based on 100% of the total mass of monohydroxybenzene-formaldehyde condensate (A), vinylpyridine-styrene-butadiene copolymer (B) and chloroprene rubber (C). The monohydroxybenzene-formaldehyde condensate (A) is A / (A + B + C) = 3% or more and 20% or less, and the vinylpyridine-styrene-butadiene copolymer (B) is B / (A + B + C) = 15%. The glass fiber coating coating liquid described above, which contains 85% or less of chloroprene rubber (C) in a range of C / (A + B + C) = 5% or more and 50% or less.

  Furthermore, the present invention contains a styrene-butadiene copolymer, and is a mass percentage based on 100% of the total mass of the vinylpyridine-styrene-butadiene copolymer (B) and the styrene-butadiene copolymer. In other words, the glass fiber coating coating liquid described above contains a styrene-butadiene copolymer in a range of 5% to 70%.

  In this way, the glass fiber coating coating solution of the present invention is applied to the strands that have been bundled after the bundling agent containing a silane coupling agent and a resin is applied to a plurality of glass fiber filaments, specifically a large number of glass fiber filaments. The glass fiber for rubber reinforcement provided with a coating layer containing a coating layer containing a monohydroxybenzene-formaldehyde condensate (A), a vinylpyridine-styrene-butadiene copolymer (B) and a chloroprene rubber (C) is chloroprene rubber. It was found to have excellent adhesion.

  By including the monohydroxybenzene-formaldehyde condensate (A) in the coating layer of the rubber reinforcing glass fiber, the heat resistance and water resistance of the transmission belt and the conveyor belt in which the rubber reinforcing glass fiber is embedded are improved. By including the vinylpyridine-styrene-butadiene copolymer (B) in the glass fiber coating layer for rubber reinforcement, the mechanical durability of the power transmission belt and the conveyor belt in which the glass fiber for rubber reinforcement is embedded is maintained. It is. By including the chloroprene rubber (C) in the coating layer of the glass fiber for reinforcing rubber, a preferable adhesive force between the glass fiber for reinforcing rubber and the chloroprene rubber as the base material is developed.

  Furthermore, the present invention is a glass fiber for reinforcing rubber embedded in a transmission belt having chloroprene rubber as a base material, and a monohydroxybenzene-formaldehyde condensate (A) is formed on a strand obtained by bundling a plurality of glass fiber filaments. A glass fiber for reinforcing rubber, which is provided with a coating layer containing a vinylpyridine-styrene-butadiene copolymer (B) and chloroprene (C).

    The composition ratio of the monohydroxybenzene-formaldehyde condensate (A), the vinylpyridine-styrene-butadiene copolymer (B) and the chloroprene rubber (C) contained in the coating layer of the rubber reinforcing glass fiber of the present invention is By adjusting, it became possible to obtain a preferable adhesive force between the glass fiber for rubber reinforcement and the chloroprene rubber as the base material, and to have a good balance between heat resistance and water resistance.

  In the present invention, the total mass of monohydroxybenzene-formaldehyde condensate (A), vinylpyridine-styrene-butadiene copolymer (B) and chloroprene (C) contained in the coating layer is based on 100%. Expressed in mass percentage, monohydroxybenzene-formaldehyde condensate (A), A / (A + B + C) = 3% to 20%, vinylpyridine-styrene-butadiene copolymer (B) in the primary coating layer. B / (A + B + C) = 15% or more and 85% or less, and chloroprene rubber (C) is contained in the range of C / (A + B + C) = 5% or more and 50% or less. Glass fiber.

  Further, in the present invention, the coating layer contains a styrene-butadiene copolymer, and the total mass of the vinylpyridine-styrene-butadiene copolymer (B) and the styrene-butadiene copolymer is based on 100%. The above glass fiber for reinforcing rubber, characterized by containing a styrene-butadiene copolymer in a range of 5% to 70% in terms of mass percentage.

  Furthermore, the present invention is a power transmission belt characterized in that the rubber reinforcing glass fiber is embedded in rubber mainly composed of chloroprene rubber.

    Moreover, the present invention is a conveyor belt characterized in that the glass fiber for rubber reinforcement is embedded in rubber mainly composed of chloroprene rubber.

  According to the present invention, a power transmission belt in which chloroprene rubber is used as a base material and rubber reinforcing glass fibers for reinforcement are embedded, and durability such as heat resistance and water resistance is provided in a balanced manner to the conveyor belt, and in addition, chloroprene rubber and A glass fiber coating coating solution that gives a coating layer having excellent adhesive strength and rubber reinforcing glass fibers using the same were obtained.

It is a schematic diagram of the test piece of a MIT bending test. It is a schematic diagram of the test condition of a MIT bending test.

  The present invention relates to a glass fiber coating coating solution for providing a coating layer on a glass fiber for rubber reinforcement for embedding in a transmission belt having chloroprene rubber as a base material, and the monohydroxybenzene-formaldehyde condensate (A) And a vinylpyridine-styrene-butadiene copolymer (B) and chloroprene (C).

  The composition ratio of the monohydroxybenzene-formaldehyde condensate (A), the vinylpyridine-styrene-butadiene copolymer (B), and the chloroprene rubber (C), which are contained in the coating solution for coating glass fibers of the present invention, is adjusted. Thus, it is possible to obtain a preferable adhesive force between the glass fiber for reinforcing rubber and the chloroprene rubber which is the base material, and to have a good balance between heat resistance and water resistance.

  When the content of monohydroxybenzene-formaldehyde condensate (A) in the coating solution for glass fiber coating is less than A / (A + B + C) = 3%, the glass for rubber reinforcement provided with a coating layer by the coating solution for glass fiber coating The heat resistance and water resistance of the transmission belt and conveyor belt in which the fibers are embedded are lowered. Further, when the content of the monohydroxybenzene-formaldehyde condensate (A) is more than A / (A + B + C) = 20%, the rubber reinforcing glass provided with a coating layer formed by coating and coating the glass fiber coating coating solution. The adhesion between the fiber and chloroprene rubber is reduced.

  Further, when the content of the vinylpyridine-styrene-butadiene copolymer (B) in the coating solution for glass fiber coating is less than B / (A + B + C) = 15%, the coating solution for glass fiber coating is coated. The flexibility of the glass fiber for rubber reinforcement provided with the coating layer is lowered, and the mechanical durability is lowered. When the content of vinylpyridine-styrene-butadiene copolymer (B) in the coating solution for glass fiber coating is more than B / (A + B + C) = 85%, rubber reinforcement provided with a coating layer by the coating solution for glass fiber coating The heat resistance and oil resistance of the transmission belt and conveyor belt in which the glass fiber is embedded are reduced.

  Further, when the content of chloroprene rubber (C) in the glass fiber coating solution is less than C / (A + B + C) = 5%, rubber reinforcement provided with a coating layer formed by coating and coating the glass fiber coating solution Adhesive strength between glass fiber and chloroprene rubber is reduced. Further, when the content of chloroprene rubber (C) is more than C / (A + B + C) = 50%, the heat resistance of the transmission belt and the conveyor belt embedded with the rubber reinforcing glass fiber provided with the coating layer by the coating solution for glass fiber coating. And mechanical durability is reduced.

  That is, the present invention represents the mass percentage based on 100% of the total mass of monohydroxybenzene-formaldehyde condensate (A), vinylpyridine-styrene-butadiene copolymer (B), and chloroprene rubber (C). Then, monohydroxybenzene-formaldehyde condensate (A) is added to the primary coating layer, A / (A + B + C) = 3% or more and 20% or less, vinylpyridine-styrene-butadiene copolymer (B), B / ( A + B + C) = 15% or more, 85% or less, and chloroprene rubber (C) in the range of C / (A + B + C) = 5% or more and 50% or less. is there.

  In the glass fiber coating coating solution of the present invention, a part of the vinylpyridine-styrene-butadiene copolymer (B) can be used in place of the styrene-butadiene copolymer. In the coating solution for glass fiber coating of the present invention, the total mass of the vinylpyridine-styrene-butadiene copolymer (B) and the styrene-butadiene copolymer is expressed as a mass percentage based on 100%, and the styrene-butadiene copolymer The polymer is used in the range of 5% to 70%.

When the content of the styrene-butadiene copolymer is less than 5%, the coating layer of the glass fiber for reinforcing rubber is tacky, and there is no effect of suppressing the coating layer from being easily transferred. Preferably, it is 25% or more. When it exceeds 70%, the adhesiveness with chloroprene as a base material and the heat resistance when embedded in chloroprene rubber and used as a transmission belt or a conveyor belt are lost. Preferably, it is 55% or less.

  That is, the present invention further contains a styrene-butadiene copolymer, and the mass percentage based on 100% of the total mass of the vinylpyridine-styrene-butadiene copolymer (B) and the styrene-butadiene copolymer. In the above-mentioned coating solution for coating glass fibers, the styrene-butadiene copolymer is contained in the range of 5% to 70%.

  In addition, in the glass fiber coating coating liquid of the present invention, when a resorcin-formaldehyde condensate is contained, a transmission belt and a conveyor belt embedded with rubber reinforcing glass fibers provided with a coating layer by the glass fiber coating coating liquid. Since heat resistance and water resistance fall, it is preferable not to contain.

  Moreover, since the adhesive force of the glass fiber for rubber reinforcement and chloroprene rubber will fall when the coating liquid for glass fiber coating of this invention contains chlorosulfonated polyethylene, it is preferable not to contain chlorosulfonated polyethylene.

  The glass fiber coating coating solution is applied by means of, for example, heating and drying after the strand is bent and forcibly adhered in the glass fiber coating coating solution.

    The present invention also relates to a rubber fiber reinforcing glass fiber embedded in a transmission belt having chloroprene rubber as a base material, and a monohydroxybenzene-formaldehyde condensate (A) on a strand in which a plurality of glass fiber filaments are bundled. A glass fiber for reinforcing rubber, which is provided with a coating layer containing vinyl pyridine-styrene-butadiene copolymer (B) and chloroprene rubber (C).

    When the content of the monohydroxybenzene-formaldehyde condensate (A) contained in the coating layer is less than A / (A + B + C) = 3%, the heat resistance and water resistance of the transmission belt and the conveyor belt in which the glass fiber for rubber reinforcement is embedded are reduced. descend. On the other hand, when the content of the monohydroxybenzene-formaldehyde condensate (A) is more than A / (A + B + C) = 20%, the adhesive force between the rubber reinforcing glass fiber and the chloroprene rubber is lowered.

  Further, if the content of the vinylpyridine-styrene-butadiene copolymer (B) contained in the coating layer is less than B / (A + B + C) = 15%, the water resistance of the transmission belt and the conveyor belt embedded with glass fibers for rubber reinforcement And mechanical durability is reduced.

  Further, when the content of the vinylpyridine-styrene-butadiene copolymer (B) contained in the coating layer is more than B / (A + B + C) = 85%, the heat resistance of the transmission belt and the conveyor belt embedded with the reinforcing glass fiber and Oil resistance is reduced.

  On the other hand, when the content of the chloroprene rubber (C) contained in the coating layer is less than C / (A + B + C) = 5%, the adhesive strength between the rubber reinforcing glass fiber and the chloroprene rubber is lowered.

  On the other hand, if the content of chloroprene rubber (C) is more than C / (A + B + C) = 50%, the heat resistance and mechanical durability of the transmission belt and the conveyor belt in which the rubber fibers for rubber reinforcement are embedded are lowered. That is, in the present invention, the total mass of the monohydroxybenzene-formaldehyde condensate (A), the vinylpyridine-styrene-butadiene copolymer (B) and the chloroprene rubber (C) contained in the coating layer is based on 100%. In the primary coating layer, A / (A + B + C) = 3% or more and 20% or less, vinylpyridine-styrene-butadiene copolymer (B) B / (A + B + C) = 15% or more and 85% or less, and chloroprene rubber (C) in the range of C / (A + B + C) = 5% or more and 50% or less. Glass fiber.

  Moreover, in the coating layer of the glass fiber for rubber reinforcement of the present invention, a part of the vinylpyridine-styrene-butadiene copolymer (B) can be used in place of the styrene-butadiene copolymer. In the coating layer of the glass fiber for reinforcing rubber of the present invention, the mass of vinyl pyridine-styrene-butadiene copolymer (B) and styrene-butadiene copolymer combined is expressed as a mass percentage based on 100%, and styrene- A butadiene copolymer is used in the range of 5% to 70%. When the content of the styrene-butadiene copolymer is less than 5%, the coating layer of the glass fiber for reinforcing rubber is tacky, and there is no effect of suppressing the coating layer from being easily transferred. Preferably, it is 25% or more. When it exceeds 70%, the adhesiveness with chloroprene as a base material and the heat resistance when embedded in chloroprene rubber and used as a transmission belt or a conveyor belt are lost. Preferably, it is 55% or less.

    That is, the present invention further contains a styrene-butadiene copolymer, and the mass percentage based on 100% of the total mass of the vinylpyridine-styrene-butadiene copolymer (B) and the styrene-butadiene copolymer. The rubber reinforcing glass fiber is characterized by containing a styrene-butadiene copolymer in a range of 5% to 70%.

  In addition, if the glass fiber for reinforcing rubber of the present invention contains a resorcin-formaldehyde condensate in the coating layer, the heat resistance and water resistance of the power transmission belt and conveyor belt embedded with the glass fiber for reinforcing rubber are reduced. Preferably not.

  In addition, when chlorosulfonated polyethylene is contained in the rubber-reinforced glass fiber coating layer of the present invention, the adhesive force between the rubber-reinforced glass fiber and chloroprene rubber is reduced, so it is preferable not to contain chlorosulfonated polyethylene. .

  The glass fiber for reinforcing rubber according to the present invention is embedded in chloroprene rubber and molded into various transmission belts and conveyor belts. Heat is applied during molding to the transmission belt and conveyor belt, and vulcanization and curing are performed at that time.

  Monohydroxybenzene-formaldehyde condensate (A), vinylpyridine-styrene-butadiene copolymer (B), styrene-butadiene copolymer used in the glass fiber coating coating solution and rubber reinforcing glass fiber using the same of the present invention The polymer will be described.

  The monohydroxybenzene-formaldehyde condensate (A) is a resol-type monohydroxybenzene-formaldehyde condensate reacted in the presence of alkali at a molar ratio of formaldehyde to monohydroxybenzene of 0.5 to 3.0. It is preferable to use the product (A) because it has the effect of stabilizing the coating solution for coating glass fibers without precipitation of solids. If the molar ratio of formaldehyde is less than 0.5, the adhesion strength between the glass fiber for rubber reinforcement and the heat-resistant rubber is inferior, and if it exceeds 3.0, the glass fiber coating coating solution tends to gel. By using the resol type monohydroxybenzene-formaldehyde condensate (A), the liquid stability of the coating solution for glass fiber coating is improved. Examples of the alkali include lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, and barium hydroxide.

  Examples of the monohydroxybenzene-formaldehyde condensate (A) include a product name, cash register top, model number PL-4667, manufactured by Gunei Chemical Industry Co., Ltd., which is commercially available as an industrial phenol resin.

    The monohydroxybenzene-formaldehyde condensate is water-soluble. When preparing the coating solution for coating glass fibers of the present invention, the vinylpyridine-styrene-butadiene copolymer (B) is added to the aqueous solution of these condensates. Add emulsion and emulsion of chloroprene rubber (C).

  Examples of the vinylpyridine-styrene-butadiene copolymer (B) include Nippon A & L Co., Ltd., trade names, and pilatex.

  The styrene-butadiene copolymer includes Nippon A & L Co., Ltd., trade name, J-9049, manufactured by JSR Corporation, model number 2108, Nipol LX112, manufactured by Nippon Zeon Co., Ltd., trade name, L-1432, etc. Is mentioned.

Examples of the chloroprene rubber (C) include trade names LC-501, LM-61, LV-60N, and LT-50 manufactured by Denki Kagaku Kogyo Co., Ltd.

  When an acrylonitrile butadiene copolymer is contained in the glass fiber coating solution of the present invention and the glass fiber coating layer for rubber reinforcement, the adhesion between the glass fiber for rubber reinforcement and the chloroprene rubber as the base rubber is improved. Further, oil resistance is imparted to a transmission belt or a conveyor belt in which the rubber reinforcing glass fiber of the present invention is embedded. The glass fiber for rubber reinforcement is made more chloroprene by adding an acrylonitrile-butadiene-styrene terpolymer obtained by adding styrene to the polymerization monomer as an acrylonitrile-butadiene copolymer instead of an acrylonitrile-butadiene binary copolymer. Water resistance is obtained without lowering the heat resistance and oil resistance of the transmission belt and conveyor belt embedded in rubber, and it is easy to obtain an excellent transmission belt.

    Examples of the acrylonitrile-butadiene copolymer include trade names, Nipol L1561, Nipol L1562, and Nipol SX1503 manufactured by Nippon Zeon Co., Ltd.

    Examples of the acrylonitrile-butadiene-styrene terpolymer include ZEON Corporation, trade names, Nipol L1577K, and Nipol L1571CL.

  Further, the coating layer of the glass fiber for reinforcing rubber of the present invention may contain an anti-aging agent, a pH adjuster, a stabilizer and the like. Examples of the anti-aging agent include diphenylamine compounds, and examples of the pH adjusting agent include ammonia.

    In the glass fiber for rubber reinforcement of the present invention, the glass fiber for rubber reinforcement has sufficient adhesive strength with the chloroprene rubber as the base material due to the coating layer, so that the timing belt whose base material is hydrogenated nitrile rubber is used. There is no need to provide a secondary coating layer as in the case of embedding.

Example 1
(Preparation of coating solution for glass fiber coating)
To the monohydroxybenzene-formaldehyde condensate (A), an emulsion of vinylpyridine-styrene-butadiene copolymer (B), an emulsion of chloroprene rubber (C), aqueous ammonia, and water are added to cover the glass fiber of the present invention. A coating solution was prepared.

  Specifically, an aqueous solution of a commercially available monohydroxybenzene-formaldehyde condensate (A) (manufactured by Gunei Chemical Industry Co., Ltd., trade name, cash register top, model number PL-4667, solid content, 50% by mass, used in Examples below) The aqueous solution of monohydroxybenzene-formaldehyde condensate (A) was diluted with an aqueous sodium hydroxide solution having a concentration of 1% by mass at a twice mass ratio. An aqueous solution of the monohydroxybenzene-formaldehyde condensate (A), 63 parts by weight, and an emulsion of vinylpyridine-styrene-butadiene copolymer (B) (manufactured by Nippon A & L Co., Ltd., trade name, pilatex, solid content, 41 0.0 mass%, used in the examples below), 330 parts by weight, and emulsion of chloroprene rubber (C) (manufactured by Denki Kagaku Kogyo Co., Ltd., trade name, LC-501, solid content, 50%) 137 parts by weight Then, 22 parts by weight of ammonia water (concentration: 25.0% by mass) was added as a pH adjuster, and water was added so as to be 1000 parts by weight as a whole to prepare a coating solution for coating glass fibers.

  The content ratio of each component in the coating solution for glass fiber coating is the sum of monohydroxybenzene-formaldehyde condensate (A), vinylpyridine-styrene-butadiene copolymer (B), and acrylonitrile-butadiene copolymer (C). The monohydroxybenzene-formaldehyde condensate (A) is A / (A + B + C) = 7.2%, and the vinylpyridine-styrene-butadiene copolymer (B) is expressed as a mass percentage based on 100%. B / (A + B + C) = 61.7% and chloroprene rubber (C) is C / (A + B + C) = 31.1%. The mass of monohydroxybenzene-formaldehyde condensate (A), vinylpyridine-styrene-butadiene copolymer (B) and chloroprene rubber (C) in the glass fiber coating solution is converted from solid content to solid content. And asked. The coating layer of the glass fiber for reinforcing rubber becomes almost the same as it is.

(Production of glass fiber for rubber reinforcement)
After aligning three strands in which 200 strands of glass fiber filaments having a diameter of 9 μm are bundled using a sizing agent containing an acrylic silane coupling agent and a resin, the coating solution for coating glass fibers prepared in the above-described procedure is used. After coating, the coating layer was provided by drying at a temperature of 280 ° C. for 22 seconds to produce one rubber reinforcing glass fiber.

  At this time, the solid content adhesion rate, that is, the mass ratio of the coating layer was 19.0 mass% with respect to the total mass of the glass fiber for rubber reinforcement.

Example 2
Monohydroxybenzene-formaldehyde condensate (A), vinylpyridine-styrene-butadiene copolymer (B) emulsion, chloroprene rubber (C) emulsion, acrylonitrile-butadiene-styrene terpolymer emulsion and aqueous ammonia And water were added to prepare a coating solution for coating glass fibers of the present invention.

  The above-mentioned aqueous solution of a monohydroxybenzene-formaldehyde condensate obtained by diluting an aqueous solution of a commercially available monohydroxybenzene-formaldehyde condensate with a sodium hydroxide aqueous solution having a concentration of 1% by mass at a double mass ratio was used. An aqueous solution of the monohydroxybenzene-formaldehyde condensate, 63 parts by weight, an emulsion of the vinylpyridine-styrene-butadiene terpolymer (B), 280 parts by weight, and an emulsion of chloroprene rubber (C), 100 parts by weight And an emulsion of acrylonitrile-butadiene-styrene terpolymer (made by Nippon Zeon Co., Ltd., trade name, Nipol L1577K solid content concentration, 38.0 mass%), 102 parts by weight, and aqueous ammonia as a pH adjuster ( Concentration, 25.0% by mass) 22 parts by weight was added, and water was added so that the total amount was 1000 parts by weight to prepare a coating solution for fiber coating.

  The content ratio of each component in the glass fiber coating solution is as follows: monohydroxybenzene-formaldehyde condensate (A), vinylpyridine-styrene-butadiene copolymer (B), chloroprene rubber (C), and acrylonitrile- Expressed as a mass percentage based on 100% of the total mass of the butadiene-styrene terpolymer, the monohydroxybenzene-formaldehyde condensate (A) is 7.2%, the vinylpyridine-styrene-butadiene copolymer ( B) is 52.3%, chloroprene rubber (C) is 22.8%, and acrylonitrile-butadiene-styrene terpolymer (C) is 17.7%. Monohydroxybenzene-formaldehyde condensate (A), vinylpyridine-styrene-butadiene copolymer (B), chloroprene rubber (C) and acrylonitrile-butadiene-styrene terpolymer in the coating solution for glass fiber coating The mass of was determined by converting solid content concentration to solid content. The coating layer of the glass fiber for reinforcing rubber becomes almost the same as it is. Next, a glass fiber for rubber reinforcement was produced in the same manner as in Example 1.

  At this time, the solid content adhesion rate, that is, the mass ratio of the coating layer was 19.0 mass% with respect to the total mass of the glass fiber for rubber reinforcement.

Comparative Example 1
An emulsion of vinylpyridine-styrene-butadiene copolymer (B), an emulsion of chloroprene rubber (C), aqueous ammonia and water were added to the resorcin-formaldehyde condensate to prepare a coating solution for glass fiber coating.

  The content ratio of each component in the coating solution for coating glass fiber is a mass based on 100% based on the total mass of resorcin-formaldehyde condensate, vinylpyridine-styrene-butadiene copolymer (B) and chloroprene rubber (C). Expressed as a percentage, the resorcin-formaldehyde condensate is adjusted to 7.2%, the vinylpyridine-styrene-butadiene polymer (B) is 61.7%, and the chloroprene rubber (C) is 31.1%. Subsequently, p-dinitrosobenzene as a vulcanizing agent and carbon black as an inorganic filler were added in the same manner as in Example 1 to prepare a coating solution for glass fiber coating. The coating layer of the glass fiber for reinforcing rubber becomes almost the same as it is. Next, a glass fiber for rubber reinforcement was produced in the same manner as in Example 1.

  At this time, the solid content adhesion rate, that is, the mass ratio of the coating layer was 19.0 mass% with respect to the total mass of the glass fiber for rubber reinforcement.

Comparative Example 2
Addition of emulsion of vinylpyridine-styrene-butadiene copolymer (B), emulsion of chlorosulfonated polyethylene, ammonia water and water to monohydroxybenzene-formaldehyde condensate (A) to prepare a coating solution for glass fiber coating did. In addition, commercially available Sumitomo Seika Co., Ltd. make, brand name, CSM-450, solid content, 40.0 mass% was used for chlorosulfonated polyethylene.

  The content ratio of each component in the coating solution for glass fiber coating is 100% of the total mass of monohydroxybenzene-formaldehyde condensate (A), vinylpyridine-styrene-butadiene copolymer (B) and chlorosulfonated polyethylene. Expressed as a percentage by mass, the monohydroxybenzene-formaldehyde condensate is 7.2%, the vinylpyridine-styrene-butadiene polymer (B) is 61.7%, and the chlorosulfonated polyethylene is 31.1%. Thus, a glass fiber coating coating solution was prepared. The coating layer of the glass fiber for reinforcing rubber becomes almost the same as it is. Next, a glass fiber for rubber reinforcement was produced in the same manner as in Example 1.

  At this time, the solid content adhesion rate, that is, the mass ratio of the coating layer was 19.0 mass% with respect to the total mass of the glass fiber for rubber reinforcement.

(Evaluation test of bond strength between glass fiber for reinforcing rubber and chloroprene rubber)
Before describing the adhesive strength evaluation test, the heat resistant rubber used in the test will be described.

    Chloroprene rubber as a base material, 100 parts by weight, carbon black, 40 parts by weight, zinc white, 5 parts by weight, stearic acid, 0.5 parts by weight, sulfur, 0.4 parts by weight, A sulfur accelerator, 2.5 parts by weight, and an antioxidant, 1.5 parts by weight were blended.

The test piece is a 3 mm thick, 25 mm wide rubber sheet made of chloroprene rubber, and 20 rubber reinforcing glass fibers (Examples 1 and 2 and Comparative Examples 1 and 2) are arranged on top of each other. Under the condition of 150 ° C. under the condition of 196 Newton / cm ² , the end portion was pressed and molded while vulcanizing for 35 minutes to obtain a test piece for evaluating the adhesive strength. For the measurement of the adhesive strength of the test piece, each rubber sheet and rubber reinforcing glass fiber are individually clamped at the end, the peeling speed is 50 mm / min, and the rubber reinforcing glass fiber is peeled off from the rubber sheet. The maximum resistance value at the time was measured to determine the adhesive strength. The greater the adhesive strength, the better the adhesive strength.

(Adhesion strength evaluation results)
Table 1 shows the evaluation results of the adhesive strength. In Table 1, the destruction state in which the glass fiber and the chloroprene rubber were not peeled from the interface was defined as rubber failure, and the destruction state in which only a part of the glass fiber and chloroprene rubber were separated from the interface was defined as interface peeling. Rubber destruction is superior in adhesion strength to interfacial peeling. Table 1 shows the adhesion strength of each glass fiber for reinforcing rubber to chloroprene rubber.

  As shown in Table 1, the rubber reinforcing glass fibers of the present invention (Examples 1 and 2), the rubber reinforcing glass fibers not within the scope of the present invention (Comparative Example 1), and the chloroprene rubber have the same adhesive strength (338 N). ˜345N), the peeled state was rubber breakdown, and showed good adhesion. Adhesion of chloroprene rubber and glass fiber for reinforcing rubber containing monohydroxybenzene-formaldehyde condensate (A), vinylpyridine-styrene-butadiene copolymer (B) and chlorosulfonated polyethylene to the coating layer of Comparative Example 2 The strength was as weak as 112N, and the peeling state was also interfacial peeling. This is due to the chlorosulfonated polyethylene contained in the coating layer of the glass fiber for reinforcing rubber of Comparative Example 2.

(Evaluation results of water resistance, heat resistance and oil resistance by MIT bending test of glass fibers for rubber reinforcement)
Using the glass fiber for rubber reinforcement produced in Examples 1 and 2 and Comparative Example 1 as a reinforcing material, the chloroprene rubber is used as a base material, and two cords are provided in rubber having a thickness of 2 mm, a width of 5 mm, and a length of 250 mm. After being embedded, it was cured while being vulcanized at 150 ° C. for 35 minutes to prepare test piece samples for the MIT flex test, and the heat resistance, water resistance and oil resistance were evaluated.

  For heat resistance, the test piece was heated to 150 ° C. for 240 hours in a heating furnace and returned to room temperature, and then the end of the test piece was attached with a 3 kg weight and bent at an angle of 210 degrees 1200 times, and then Tensile strength was measured.

  For water resistance, immerse the test piece in a beaker containing water, boil it over a gas burner for 2 hours, remove it, wipe off the water, attach a 3 kg weight to the end of the test piece, and place it at an angle of 210 degrees. Then, bending was repeated 1200 times, and then the tensile strength was measured.

  Also, for oil resistance, after immersing the test piece in automotive engine oil heated to 120 ° C. for 100 hours and taking it out, wiping off the engine oil and attaching a 3 kg weight to the end of the test piece, an angle of 210 degrees Then, bending was repeated 1200 times, and then the tensile strength was measured.

  As described above, in order to evaluate heat resistance, water resistance, and oil resistance, after accelerating the deterioration, the MIT bending test was repeated 1200 times at an angle of 210 degrees, and the heat resistance when the transmission belt was formed. It was used as an index for evaluation of water resistance, water resistance and oil resistance.

  FIG. 1 is a schematic view of a test piece of the MIT flex test.

  The size of the test piece 1 is 2 mm in height, 5 mm in width, and 250 mm in length, and the glass fibers 3 for rubber reinforcement according to Examples 1 and 2 and Comparative Example 1 are embedded inside the chloroprene rubber 2.

  FIG. 2 is a schematic diagram of the test situation of the MIT flex test.

  The bending angle of the clamp is 120 degrees, and the test piece 1 is bent 1200 times with the weight 4 attached.

  Table 2 shows the evaluation results of water resistance, heat resistance, and oil resistance by the MIT bending test of the test piece 1 using each glass fiber 3 for reinforcing rubber. In order to evaluate water resistance, heat resistance, and oil resistance, the tensile strength retention rate of each test piece 1 after the MIT flex test was measured.

The numerical values in Table 2 are tensile strength retention ratios, and were obtained by the following equation (1).

  As shown in Table 2, the heat resistance was such that the tensile strength retention ratios of the glass fibers for rubber reinforcement of the present invention shown in Examples 1 and 2 were 74% and 77%, respectively. The tensile strength retention rate of the glass fiber for rubber reinforcement not within the scope of the invention was 48%. This is the effect of the monohydroxybenzene-formaldehyde condensate contained in the coating layer in the rubber reinforcing glass fibers of Examples 1 and 2 of the present invention. The glass fiber for rubber reinforcement of Comparative Example 1 contains resorcin-formaldehyde condensate in the coating layer.

  Further, the water resistance is that the rubber reinforcing glass fiber tensile strength retention ratios of the present invention shown in Examples 1 and 2 are 80% and 82%, respectively, and the rubber that is not in the category of the present invention shown in Comparative Example 1 The reinforcing glass fiber tensile strength retention was 62%. This is the effect of the monohydroxybenzene-formaldehyde condensate contained in the coating layer in the rubber reinforcing glass fibers of Examples 1 and 2 of the present invention. The glass fiber for rubber reinforcement of Comparative Example 1 contains resorcin-formaldehyde condensate in the coating layer.

  In comparison, in terms of oil resistance, the tensile strength retention of the rubber reinforcing glass fiber of the present invention shown in Example 1 is 73%, and the tensile strength of the rubber reinforcing glass fiber of the present invention shown in Example 2 is The strength retention was 80%, and the tensile strength retention of the glass fiber for rubber reinforcement not included in the scope of the present invention shown in Comparative Example 1 was 72%. This is the effect of the acrylonitrile-butadiene-styrene terpolymer contained in the coating layer in the glass fiber for rubber reinforcement of Example 2 of the present invention.

1 Test piece 2 Chloroprene rubber 3 Glass fiber for rubber reinforcement 4 Weight

Claims (8)

A glass fiber coating coating solution for providing a coating layer on a glass fiber for reinforcing rubber embedded in a transmission belt having chloroprene rubber as a base material, which is a monohydroxybenzene-formaldehyde condensate (A) and vinylpyridine-styrene- A glass fiber coating coating solution comprising a butadiene copolymer (B) and a chloroprene rubber (C). The monohydroxybenzene-formaldehyde condensate (A), the vinylpyridine-styrene-butadiene copolymer (B), and the chloroprene rubber (C) are expressed in terms of mass percentage based on 100%. The formaldehyde condensate (A) is A / (A + B + C) = 3% or more and 20% or less, and the vinylpyridine-styrene-butadiene copolymer (B) is B / (A + B + C) = 15% or more and 85% or less. The glass fiber coating coating solution according to claim 1, wherein the chloroprene rubber (C) is contained in a range of C / (A + B + C) = 5% or more and 50% or less. Furthermore, it contains a styrene-butadiene copolymer, and is expressed as a mass percentage based on 100% of the total mass of the vinylpyridine-styrene-butadiene copolymer (B) and the styrene-butadiene copolymer. The glass fiber coating coating solution according to claim 1 or 2, which contains a butadiene copolymer in a range of 5% to 70%. A glass fiber for reinforcing rubber embedded in a transmission belt using chloroprene rubber as a base material, and a monohydroxybenzene-formaldehyde condensate (A) and vinylpyridine-styrene- A glass fiber for reinforcing rubber, which is provided with a coating layer containing a butadiene copolymer (B) and a chloroprene rubber (C). Expressed as a mass percentage based on 100% of the total mass of monohydroxybenzene-formaldehyde condensate (A), vinylpyridine-styrene-butadiene copolymer (B) and chloroprene rubber (C) contained in the coating layer. In the coating layer, monohydroxybenzene-formaldehyde condensate (A), A / (A + B + C) = 3% to 20%, vinylpyridine-styrene-butadiene copolymer (B), B / (A + B + C) = The glass fiber for rubber reinforcement according to claim 4, comprising 15% or more and 85% or less of chloroprene rubber (C) in a range of C / (A + B + C) = 5% or more and 50% or less. Furthermore, it contains a styrene-butadiene copolymer, and is expressed as a mass percentage based on 100% of the total mass of the vinylpyridine-styrene-butadiene copolymer (B) and the styrene-butadiene copolymer. The glass fiber for rubber reinforcement according to claim 4 or 5, comprising a butadiene copolymer in a range of 5% to 70%. A power transmission belt, wherein the glass fiber for rubber reinforcement according to any one of claims 4 to 6 is embedded in rubber mainly composed of chloroprene rubber. A conveyor belt, wherein the rubber reinforcing glass fiber according to any one of claims 4 to 6 is embedded in rubber mainly composed of chloroprene rubber.

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