| abstract |
An infrared shield that satisfactorily transmits visible light, not having any half mirror appearance and does not need any large-scale production apparatus in the film formation on base material, and that not requiring any high temperature heat treatment after film formation, efficiently blocks invisible near-infrared rays of 780 nm or above wavelength and is transparent and free from color tone changes. An infrared shielding film of transmission profile shown was obtained by a process comprising providing a starting material resulting from weighing of given amount of tungsten compounds and mixing thereof; heating the starting material in a reducing atmosphere at 550˚C for 1 hr, lowering the temperature to room temperature once and thereafter heating the material in an argon atmosphere for 1 hr to thereby obtain powder of W18O49; mixing the powder with a solvent and a dispersant and dispersing them into a dispersion liquid; mixing this dispersion liquid with an ultraviolet curable resin for hard coat to thereby obtain an infrared shielding material microparticle dispersion liquid; coating a PET resin film with this infrared shielding material microparticle dispersion liquid so as to effect film formation; and curing the coating film. |