ACTIVE IRON POWDER, EXOTHERMAL COMPOSITION AND EXOTHERMAL ARTICLE

摘要

There is provided an active iron powder which is suitable for a heat generating composition of a heat generating body, is excellent in rising properties and is excellent in economy by using an iron powder which is generally produced at present and modifying its function into an active iron powder suitable as a raw material of a heat generating body. The invention is concerned with an active iron powder to be contained in a heat generating composition capable of generating heat upon contact with air, characterized in that in the active iron powder, a part of the surface of the iron powder is covered by an iron oxide film; and that a thickness of the iron oxide film is from 3 nm to 100 µm and is not more than 50 % of the total thickness of the active iron powder.