JP-7854687-B2 - Scaling agent for long glass fibers

Inventors

• 林 哲也
• 宮崎 崇治

Assignees

• ユニチカ株式会社
• ユニチカグラスファイバー株式会社

Dates

Publication Date

20260507

Application Date

20240410

Claims (2)

1. A glass cloth formed from glass yarn made by bundling long glass fibers, The glass material constituting the long glass fibers is E-glass or a glass composition having a relative permittivity of less than 5.0 at a frequency of 1 MHz. The tensile strength of the glass yarn is 0.50 N/tex or more, and the ignition loss of the glass cloth is 0.10 mass% or less. Glass cloth, wherein the aforementioned glass cloth has undergone heat cleaning treatment.
2. The glass cloth according to claim 1, used as a component material for printed circuit boards .

Description

This invention relates to a sizing agent for glass fibers. More specifically, this invention relates to a glass fiber sizing agent containing an acrylic resin as a film-forming component, which provides excellent lint suppression and excellent heat-cleaning properties even at low temperatures below 400°C. Furthermore, this invention relates to glass yarn prepared using this glass fiber sizing agent, glass cloth using this glass yarn, and a method for manufacturing this glass cloth. Glass cloth is composed of glass yarn, which is made up of multiple glass filaments bundled together. Glass yarn and glass cloth for printed circuit boards are primarily manufactured through a glass yarn manufacturing process, including a spinning process, and a glass cloth manufacturing process, including warp preparation, weaving, de-oiling, and surface treatment processes. The operations in each process are as follows: (1) Glass Yarn Manufacturing Process (1-1) Spinning Process Glass raw materials are melted in a glass melting furnace and drawn out as multiple glass long fibers. A sizing agent is applied to these multiple glass long fibers to bundle them together, forming a glass strand into a wound yarn body called a cake. (1-2) Twisting process: Glass strands are drawn from the cake and twisted in a twisting machine to make glass yarn. (2) Glass cloth manufacturing process (2-1) Preparation process Using glass yarn, the warp threads of the glass cloth are prepared by processes such as warping, sizing, and threading. (2-2) Weaving process Using the warp threads prepared above and the glass yarn to be used as the weft thread, weaving is carried out on an air jet loom or the like to produce raw cloth. (2-3) Heat cleaning process (heating and de-oiling process) Sizing agents and other substances applied to the surface of glass fibers during the spinning process can hinder the adhesion between the glass fibers and the matrix resin during prepreg manufacturing. Therefore, a heat cleaning treatment (heat de-oiling treatment) is performed to remove organic components such as sizing agents adhering to the glass cloth by heating. (2-4) Surface treatment process In prepreg manufacturing, in order to improve the adhesion between the matrix resin and the glass fibers, the heat-cleaned glass cloth is treated with a silane coupling agent. In the glass yarn and glass cloth manufacturing processes described above, the glass fibers may be partially cut, resulting in fuzzing. Fuzzing in glass cloth can lead to defects such as poor insulation when used in printed circuit boards, making it desirable to minimize fuzzing. The scrubbing agents used in the processing of glass fibers play a significant role in suppressing fuzzing in glass cloth. In sizing agents for glass fibers, starch or synthetic resins are frequently used as film-forming components. Furthermore, various glass fiber sizing agents have been proposed to improve the efficiency or eliminate the need for heat cleaning, and to enhance the suppression of fluff generation. For example, Patent Document 1 reports that using a sizing agent for glass fiber yarn containing a calcium compound can shorten the heat cleaning time and enable uniform heat cleaning. Specifically, Patent Document 1 shows that using a sizing agent for glass fiber yarn containing starch and calcium acetate can promote oxidation or decomposition so that organic matter does not remain, even with a slow oxygen supply rate, and further shorten the time required for heat cleaning. Patent Document 2 reports that by using a water-soluble epoxy resin sizing agent for glass fiber yarn to treat yarns of 1.5 to 50 tex, oil can be removed by water flow processing without heat cleaning, and it becomes possible to manufacture ultra-thin treated glass fiber fabrics with a single weight of 6 to 30 g/ m² . Patent Document 3 reports that by using a glass fiber sizing agent containing starch and an acrylic copolymer with a degree of polymerization of 3 × 10² to 1 × 10⁵ , glass fibers that are less prone to fuzzing and have excellent flight properties and hydrophilicity can be obtained, and that oil can be removed by washing with water. Japanese Patent Application Publication No. 11-106241Japanese Patent Application Publication No. 9-67757Japanese Patent Publication No. 2007-217252 1. Sizing Agent for Long Glass Fibers The sizing agent for long glass fibers of the present invention is characterized by comprising (A) an acrylic resin, (B) an oil or fat, and (C) cationized cellulose and/or polyoxyethylene alkyl ether. By incorporating the above three components as an integral part of the sizing agent for long glass fibers of the present invention, it is possible to achieve an excellent effect in suppressing fluff generation, as well as good heat cleaning properties at low temperatures below 400°C, and it is possible to avoid a decrease in strength due to heat cleaning treatment at high temperatures. The sizing agent for long glass fibers of