Abstract: A prepreg including: a thermosetting resin composition (C) containing a thermosetting resin (A) and an inorganic filler (B); and a glass cloth (D) impregnated or coated with the thermosetting resin composition (C); wherein the glass cloth (D) satisfies the following expressions (I) to (III), (x+y)?95??(I) 1.9<(X+Y)/(x+y)??(II) t<20??(III) wherein the glass cloth (D) is defined by X (threads/inch) representing number of warp yarn per inch; Y (threads/inch) representing number of weft yarn per inch; x (threads) representing number of filament per the warp yarn; y (threads) representing number of filament per the weft yarn; and t (?m) representing a thickness, and wherein the content of the inorganic filler (B) in the thermosetting resin composition (C) is from 110 to 700 parts by mass based on 100 parts by mass of the thermosetting resin (A).

Abstract: To provide a prepreg that achieves a low dielectric loss tangent, despite the use of a polar solvent. A prepreg produced by impregnating or coating a base material with a varnish comprising an inorganic filler, a polar solvent, and a resin composition principally comprising polyphenylene ether, and subjecting the base material treated to a drying step, wherein the polar solvent content of the prepreg is 3 mass % or less, and a dielectric loss tangent at 10 GHz of a laminated board produced using this prepreg is 0.001-0.007.

Abstract: Provided is an industrially superior method for producing cyclohexyl alkyl ketones, which solves the problems in process reduction and in disposal of wastes such as metals. An aromatic ketone represented by a formula (1) is nuclear-hydrogenated with pressurized hydrogen and in the presence of a solvent at a temperature of from 20 to 120° C., in the presence of a catalyst that carries from 0.

Abstract: The present invention provides an industrially available method for efficiently producing high-purity S-(?)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid excellent in solid-liquid separability from an S-(?)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid ester, and also provides products obtained by the method. Under a temperature condition of 50-80° C. in an aqueous solvent, (A) an S-(?)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid ester represented by the general formula (1) is hydrolyzed under a basic condition for 1-3 hours; then (B) the insoluble matters contained in the reaction solution resulting from the hydrolysis are removed; and (C) an acid is added to the resulting solution to effect crystallization; provided that R in the general formula (1) represents an alkyl or aryl group.