Abstract: Occurrence of EMI is reduced without a sharp increase of the manufacturing cost by suppressing a common mode current stably. There is provided a disclosed printed-circuit board being adapted such that a width of an outer edge section of a T-shaped pattern is widened so as to surround a recessed section with a frame-shaped additional electric conductor by electrically connecting the frame-shaped additional electric conductor with the T-shaped pattern making up a ground pattern so as to close the recessed section.

Abstract: There is provided a method for obtaining a target organic compound such as an alkyladamantyl ester efficiently by purifying a crude organic compound which contains, as impurities, sublimable materials which start to sublime at temperatures lower than a boiling point of the target organic compound by use of such a simple method as distillation during its production process, without being adversely affected by adherence of the sublimable materials.

Abstract: This invention discloses a process for preparing an 2-alkyl-2-adamantyl ester comprising the steps of combining a solution or suspension of 2-adamantanone and an alkyl halide with lithium metal for reacting them to generate an lithium 2-alkyl-2-adamantyl alcoholate, and then reacting the lithium 2-alkyl-2-adamantyl alcoholate with an acid halide.

Abstract: A high-purity alicyclic ketone which is a raw material for an alkyl-substituted alicyclic ester such as an alkyl adamantyl ester compound which is useful as a resist raw material can be obtained by a simple operation such as extraction without a special purification step such as distillation or recrystallization. In this process, when an alicyclic hydrocarbon is oxidized with concentrated sulfuric acid or fuming sulfuric acid, the reaction solution after oxidation is poured into water and a solid is extracted with an organic solvent, the concentration of sulfuric acid in the water layer at the time of extraction is adjusted to 60 to 90 wt % to carry out extraction so as to obtain an alicyclic ketone.

Abstract: Occurrence of EMI is reduced without a sharp increase of the manufacturing cost by suppressing a common mode current stably. There is provided a disclosed printed-circuit board being adapted such that a width of an outer edge section of a T-shaped pattern is widened so as to surround a recessed section with a frame-shaped additional electric conductor by electrically connecting the frame-shaped additional electric conductor with the T-shaped pattern making up a ground pattern so as to close the recessed section.

Abstract: Proposed is a flame-retardant heat-curable flowable epoxy resin composition suitable for use in case potting of film capacitors exhibiting very little settling of the particulate ingredients in storage and excellent impregnability in case potting as well as excellent flame retardancy, moisture resistance and tracking resistance of the composition after curing. The composition comprises, as a uniform blend:(a) 100 parts by weight of a bisphenol-based epoxy resin which is liquid at a temperature of working in case potting;(b) from 10 to 40 parts by weight of an alkyleneglycol diglycidyl ether or cycloalkyleneglycol diglycidyl ether;(c) from 80 to 120 parts by weight of a polycarboxylic acid anhydride;(d) from 4 to 20 parts by weight of a powder of red phosphorus; and(e) from 100 to 200 parts by weight of a powder of hydrated alumina which characteristically is a combination of (e1) from 80 to 95% by weight of a first powder of hydrated alumina having an average particle diameter in the range from 10 to 25 .mu.