Abstract: The invention provides a photopolymerizable composition comprising: flame-retardant particles which contains a hydrated metal and have an average diameter of about 1 to 500 nm; and a photopolymerization reactive material. The hydrated metal preferably includes at least one selected from the group consisting of a hydrated magnesium, hydrated calcium, hydrated aluminum, hydrated zinc, hydrated barium, hydrated copper and hydrated nickel. A cover layer which comprises an organic compound or a polysilicone is preferably formed on surfaces of the flame-retardant particles. The invention provides a flame-retardant resin-formed article which is formed of the photopolymerized photopolymerizable composition. A flame retardancy of the article measured in accordance with the UL-94 test preferably scores HB or higher.

Abstract: A flame-retardant epoxy resin composition, as well as an electronic device, a laminated circuit board, a multilayered circuit board and a printed circuit board employing the flame-retardant epoxy resin composition are disclosed. The flame-retardant epoxy resin composition contains: an epoxy resin; an epoxy resin curing agent; and flame-retardant particles containing a metal hydrate. The flame-retardant particles are provided with a coating layer on the surfaces thereof and have a volume average particle diameter in a range from 1 to 500 nm.

Abstract: A sheath composition and a cable using the sheath composition are disclosed. The sheath composition contains a polyolefine resin and flame-retardant particles containing a metal hydrate. The flame-retardant particles are provided with a coating layer on the surfaces thereof and have a volume average particle diameter in a range from 1 to 500 nm.

Abstract: Disclosed are an electronic material composition, an electronic device to be obtained through the employment of this electronic material composition, and a method of using this electronic material composition, wherein the electronic material composition is featured in that, even if the electronic material composition is employed as one-pack type, the changes with time of viscosity would be such that would not bring about any substantial problem in practical use, and even if the electronic material composition is exposed to fluctuations in ambient temperature, there is little possibility of generating cohesive failure or peeling fracture, thereby making it possible to enhance the handling properties of the electronic material composition in a packaging step without any possibility of giving damage to the external appearance and to prevent the deterioration of magnetic/electric properties that can be improved through the provision of a packaging body to an electronic device even if the content of an inorganic f