JPH0341593B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for gluing fiber bundles, and more particularly, to a gluing method for obtaining fiber bundles suitable for producing woven fabrics of inorganic fibers, and more specifically, to a method for gluing fiber bundles for use in inorganic fiber reinforced metals. The present invention relates to a method for sizing reinforcing fibers suitable for producing woven fabrics. In recent years, fiber-reinforced metals (hereinafter referred to as FRM) have been developed that use inorganic fibers as reinforcement and a matrix of aluminum alloy, magnesium alloy, etc.
It is used or is beginning to be used in many industrial fields. When producing FRM, inorganic fiber woven fabrics are sometimes required, but when conventional fiber glues are used, the glued inorganic fiber bundles become hard and brittle, leading to breakage during fabric production. As a result, the desired woven fabric cannot be obtained. In order to eliminate this drawback, the inventor of the present application has developed a new gluing method and is currently filing a separate application. However, even when the sizing agent according to the present invention is used, it is necessary to heat the woven fabric to a temperature of about 600°C or higher in order to remove the sizing agent before combining the woven fabric and metal. The strength of some inorganic fibers decreases, and some carbon remains on the fiber surface, which adversely affects the physical properties of the FRM after it is composited. The present inventor has arrived at the present invention as a result of intensive research into a method of gluing that can be made into a woven fabric without breaking the inorganic fibers, can be removed at low temperatures, and does not adversely affect the physical properties of FRM after being composited. The present invention is characterized in that compared to conventionally known methods, a sizing agent-treated inorganic fiber bundle can be obtained that is flexible and has excellent surface slipperiness, can be easily woven into a woven fabric, and is easily removable from the sizing agent. has. That is, in the present invention, an inorganic fiber bundle is immersed in a solution in which a methacrylic acid ester polymer and a plasticizer are dissolved in a solvent at a ratio (weight ratio) of 40:60 to 60:40, and after removing the solvent, a wax emulsion is formed. The fiber bundle is immersed in a liquid, dried, and glued so that the total amount of the methacrylic acid ester polymer, plasticizer, and wax attached to the fiber bundle is 2% by weight or more and 15% by weight or less, thereby producing an inorganic fiber bundle. This is a method for treating fibers with a sizing agent, which is characterized by imparting flexibility and surface slipperiness to fibers. The present invention will be explained in detail below. The inorganic fibers used in the present invention include carbon fibers,
These include silica fibers, silicon carbide fibers, boron fibers, and alumina fibers. These inorganic fibers are characterized by high strength and high elasticity. In particular, due to the high elasticity, the fiber itself loses its flexibility, so it tends to become hard and brittle after being treated with a general sizing agent. The elastic modulus of the inorganic fiber is preferably 15,000 to 50,000 Kg/mm ² . When the elastic modulus is less than 15,000 Kg/mm ² , the fiber bundle treated with the sizing agent of the present invention becomes too soft and difficult to handle. If it is larger than 50,000 Kg/mm ² , the rigidity becomes too high, and even if the adhesive treatment of the present invention is applied, the flexibility remains and it cannot be made into a woven fabric. The diameter of the inorganic fibers is preferably 5 to 50 μm. If it is thinner than 5 μm, it is too soft and difficult to handle. If it is thicker than 50 μm, it will be too hard and will continue to lose its flexibility even after being treated with a glue. Next, when fibers for FRM come into contact with molten aluminum alloy, etc., a moderate reaction occurs on the surface, but it is important that the fibers do not react excessively and deteriorate. For these reasons, among these inorganic fibers, the fibers that can most significantly exhibit the effects of the present invention are
It is an alumina fiber described in No.-13768. That is, the general formula

[Formula] (In the formula, Y represents one or more types of organic residues, halogens, and hydroxyl groups.) Using polyaluminoxane as a raw material and having a structural unit represented by It is an alumina fiber obtained by mixing one or more compounds containing silicon in an amount of 28% or less, and firing the precursor fiber obtained by blocking the mixture, preferably silica. (SiO ₂ ) content is 2% by weight or more, 25% by weight
The X-ray structure is α-
It is an alumina fiber that does not substantially exhibit Al ₂ O ₃ reflection. This alumina fiber contains lithium, beryllium, boron, etc. within a range that does not impair the effects of the present invention.
It may contain refractory compounds such as oxides of one or more of sodium, magnesium, phosphorus, potassium, calcium, titanium, chromium, manganese, yttrium, zirconium, lanthanum, tagsten, barium, and the like. The methacrylic acid ester polymer used in the present invention is preferably methyl, ethyl, butyl ester, etc., and may have any degree of polymerization and any form. When using liquid monomers, oligomers, etc., it is also possible to use them without a solvent by using them together with a polymerization initiator. That is, monomers or oligomers, plasticizers, and polymerization initiators such as peroxides are mixed, an inorganic fiber bundle is immersed in this mixture, taken out, and methacrylic acid ester monomers or oligomers are added by heating or other means. These methods include polymerization and sizing treatment. Generally, there is no problem as the plasticizer as long as it is a plasticizer used for methacrylic acid ester polymers, and a plasticizer for polyvinyl chloride is used as a plasticizer for methacrylic acid ester polymers. Examples include dibutyl phthalate, dioctyl phthalate, tricresyl phthalate, diethyl phthalate, dinonyl phthalate, dioctyl sebatate, and tritolylphosphate. The mixing ratio (weight ratio) of the methacrylic acid ester polymer and the plasticizer is preferably in the range of 40:60 to 60:40.
When the ratio of polymethyl methacrylate/plasticizer is less than 40/60, the glue becomes too soft and difficult to handle, and problems such as surface stickiness and decreased slipperiness occur, which is impractical. The wax used in the present invention may be of any emulsion type and has good water dispersibility and stability. The total amount of these glues attached to the inorganic fiber bundle is 2
The range is from 4% to 15% by weight, preferably from 4% to 10% by weight. If the amount of adhesion is less than 2% by weight, the convergence of the fiber bundle will decrease and the fibers will come apart, making it impossible to form a woven fabric.
If the amount of adhesion is more than 15% by weight, it is not only impractical but also loses its properties as a fiber. As the solvent for the methacrylic acid ester polymer and plasticizer used in the present invention, any solvent may be used as long as these solvents are soluble and have a relatively low boiling point. Examples include chloroform, trichlene, dichloromethane, dichloroethylene, and dichloroethane. Gluing is performed by immersing inorganic fibers in a solution containing a methacrylic acid ester polymer and a plasticizer, but this method alone does not provide sufficient surface slippage and is difficult to use for woven fabrics. After the above operation, by passing the fiber bundle through a wax emulsion liquid, a very thin wax layer is formed on the surface, and the surface slipperiness can be improved. Any method can be used to dry the fiber bundle after it has been immersed in the size solution and/or wax emulsion, but from the viewpoint of productivity, it is preferable to use hot air or a heating method. As explained above, by treating an inorganic fiber bundle by the method of the present invention, a sizing agent-treated inorganic fiber bundle that is softer and has better slipperiness than the conventional sizing agent treatment method can be obtained. It became easy to obtain woven fibers. EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited thereto. It should be noted that all percentages are by weight unless otherwise specified. Examples 1 to 5, Comparative Examples 1 to 4 Polymethyl methacrylate and dibutyl phthalate were mixed and dissolved in the amounts shown in Table 1. A dichloromethane solution was prepared. Approximately 1000 filaments of alumina fiber bundle (85% by weight alumina, 15% by weight silica, average fiber diameter 17μm, tensile strength 150Kg/mm ² , elastic modulus 23000Kg/mm ² ) were immersed in this solution, and the solid content was 20%. After immersing it in a wax emulsion solution of % by weight, it was taken out and air-dried. This glued fiber bundle was passed through a wire ring-shaped object with a diameter of 1 mm to which a load of 100 g was applied, and the fiber bundle was slid from side to side, and the number of times until the fiber broke was measured. For comparison, a similar test was conducted on fiber bundles that were not immersed in the wax emulsion solution. From Table 1, it is clear that the fiber bundles made according to the present invention are excellent in sliding frequency and surface slipperiness.

【table】

[Table] Examples 6 and 7, Comparative Examples 5 and 6 Carbon fibers (average fiber diameter 7.5 μm, tensile strength 300 Kg/mm ² , elastic modulus 23000 Kg/mm ² ) and silicon carbide fibers (average fiber diameter 15 μm) were used as inorganic fibers. , tensile strength 220Kg/
A fiber bundle of approximately 1000 filaments with ^a modulus of elasticity of 20000 Kg/mm ² ) was immersed in a dichlorometal solution of PMMA/DBP = 50/50 (solid content concentration 5%), and then a wax emulsion with a solid content concentration of 20% was immersed. After immersing it in the liquid, it was taken out and dried, and the same test as in Example 1 was conducted. For comparison, a similar test was also conducted on fiber bundles that had not been treated with a sizing agent. The results are shown in Table 2, and it can be seen that the present invention exhibits excellent effects.

[Table] Example 8 The same alumina fibers used in Examples 1 to 5 were treated with the sizing agent shown in Example 2. On the other hand, we prepared the same fibers treated with a sizing solution of polyvinyl alcohol:sodium acrylate:wax = 50:50:10 (weight ratio), and heated them at 400℃.
When heated in a furnace for one hour, the fiber bundle treated with the sizing agent of the present invention had no sizing agent remaining, whereas the fiber bundle treated with the latter method had carbon remaining in it, resulting in a black color. It was discolored. In order to use it for FRM, it is necessary to completely remove the adhesive as in the former case, and the effects of the present invention are clear.

Claims (1)

[Claims] 1 An inorganic fiber bundle is immersed in a solution in which a methacrylic acid ester polymer and a plasticizer are dissolved in a solvent at a ratio (weight ratio) of 40:60 to 60:40, and after removing the solvent, the fibers are immersed in a wax emulsion solution. Flexibility is imparted to the inorganic fiber bundle by soaking the bundle, drying, and gluing so that the total amount of methacrylic acid ester polymer, plasticizer, and wax attached to the fiber bundle is 2% by weight or more and 15% by weight or less. A method for treating fibers with a sizing agent, which is characterized by imparting surface slipperiness.