Abstract: Resin sheets which includes a support and a resin composition layer in contact on the support, and which are characterized in that an extracted water conductivity A of a cured product of the resin composition layer when extracted at 120° C. for 20 hours is 50 ?S/cm or less and an extracted water conductivity B of the cured product of the resin composition layer when extracted at 160° C. for 20 hours is 200 ?S/cm or less, can provide a thin insulating layer having excellent insulating properties.

Abstract: Resin sheets which includes a support and a resin composition layer in contact on the support, and which are characterized in that an extracted water conductivity A of a cured product of the resin composition layer when extracted at 120° C. for 20 hours is 50 ?S/cm or less and an extracted water conductivity B of the cured product of the resin composition layer when extracted at 160° C. for 20 hours is 200 ?S/cm or less, can provide a thin insulating layer having excellent insulating properties.

Abstract: Resin sheets which includes a support and a resin composition layer in contact on the support, and which are characterized in that an extracted water conductivity A of a cured product of the resin composition layer when extracted at 120° C. for 20 hours is 50 ?S/cm or less and an extracted water conductivity B of the cured product of the resin composition layer when extracted at 160° C. for 20 hours is 200 ?S/cm or less, can provide a thin insulating layer having excellent insulating properties.

Abstract: Resin sheets which includes a support and a resin composition layer in contact on the support, and which are characterized in that an extracted water conductivity A of a cured product of the resin composition layer when extracted at 120° C. for 20 hours is 50 ?S/cm or less and an extracted water conductivity B of the cured product of the resin composition layer when extracted at 160° C. for 20 hours is 200 ?S/cm or less, can provide a thin insulating layer having excellent insulating properties.

Abstract: Resin compositions containing (A) an epoxy resin, (B) a curing agent, and (C) an inorganic filler in which the content of (C) the inorganic filler is 55% by mass or higher with respect to 100% by mass of a non-volatile component within the resin composition, the average particle diameter of (C) the inorganic filler is 0.05 to 0.35 ?m, the product of the specific surface area (m2/g) of (C) the inorganic filler and the true density of (C) the inorganic filler is 1 to 77 m2/g and the moisture permeation of a cured product obtained by thermally cured the resin composition is 0.05 to 2.8 g·mm/m2·24 h are useful for making printed wiring boards.

Abstract: Resin compositions containing (A) an epoxy resin, (B) a curing agent, and (C) an inorganic filler in which the content of (C) the inorganic filler is 55% by mass or higher with respect to 100% by mass of a non-volatile component within the resin composition, the average particle diameter of (C) the inorganic filler is 0.05 to 0.35 ?m, the product of the specific surface area (m2/g) of (C) the inorganic filler and the true density of (C) the inorganic filler is 1 to 77 m2/g and the moisture permeation of a cured product obtained by thermally cured the resin composition is 0.05 to 2.8 g˜mm/m2·24 h are useful for making printed wiring boards.

Abstract: A method of technical education comprising an educational process of simulating behaviors of a flying object through a simulation program of flight functions based on basic equations of hydrodynamics, an educational process of designing the flying object and manufacturing the same, an educational process of confirming behaviors of the flying object through experimentation, and an educational process of optimizing the flying object to present targeted functions. Creative activities for obtaining an improved flying object can be performed during an educational process of experiencing effective and proper designing, manufacturing and test flying of a flying object as a teaching material. With this arrangement, the level of comprehension of hydrodynamics can be heightened from a level of passive comprehension to a level with which intellectual productive activities in the sense of creative activities can be achieved. A technical educational system and a flying object are also disclosed.