Method for manufacturing molded resin product and plastic mirror

A method for manufacturing a molded product of resin, comprising a blank molding process and an aging process separated from each other;

• said blank molding process including the step of:
• preprocessing a plastic base material approximately in a final shape in advance by injection molding,
• said aging process including the steps of:
• inserting said preprocessed plastic base material and a plastic film having a metallic reflecting film into a cavity of an aging die having a plurality of cavities and having at least one mirror face for each of said cavities, in such a manner that the metallic reflecting film of the plastic film comes in contact with the mirror face in the cavity and the plastic base material is located on a rear face side of the plastic film opposite to the metallic reflecting film;
• heating the aging die to a temperature equal to or higher than the glass transition temperature of the plastic material and keeping the cavity of the aging die under a vacuum to eliminate air bubbles during the heating;
• holding the aging die for a predetermined time at the temperature equal to or higher than the glass transition temperature so that an internal resin pressure is generated within the cavity by expansion of the plastic material, thereby to form an integral molded product by melting and joining the plastic base material and the plastic film with each other;
• and
• gradually cooling the aging die to a temperature equal to or lower than a thermal deforming temperature of the plastic material by a cooling means having a plurality of heat pipes arranged in a die plate of a press machine, said die plate being of high thermal conductivity material, and transferring the mirror face to the metallic reflecting film of the plastic film.