Patent ID: 6935793
Filing Date: 2005-08-30
Classification: G03B

Abstract:
1. A manufacturing method of a light shielding blade material for use in an optical apparatus, comprising the steps of: preparing a prepreg sheet being comprised of an epoxy resin of a thermosetting type as a matrix resin and containing a fiber drawn in an alignment direction within the matrix resin, initially no carbon black being added to the matrix resin; superposing at least three prepreg sheets upon each other so that the alignment directions of the fibers of the prepeg sheets disposed adjacent to each other cross at right angles to each other; disposing two or more films being comprised of an epoxy resin of a non-cured state as a base resin and containing greater than 15 weight % but less than or equal to 40 weight % of carbon black in the epoxy resin so that the prepreg sheets contact one surface or both surfaces of each film, the base resin of the film having a compatibility to the matrix resin of the prepreg sheet; and applying pressure and heat to a laminate of the prepreg sheets and the films to cure the epoxy resin, such that the epoxy resin constituting the base resin of the film is diffused and integrated into the matrix resin of the prepreg sheet so that an interface between the base resin and the matrix resin disappears due to the compatibility of the resins, and that the carbon black is dispersed from the base resin of the film to the matrix resin of the prepreg sheet, whereby the carbon black is finally added to the matrix resin.