Process for manufacture of decorative intermediate films for use in laminated glass sheets

Abstract

A process for the manufacture of decorative intermediate films used in laminated glass sheets which comprises the following steps: (a) forming a transfer sheet with a desired printed pattern printed over a transfer sheet substrate with an ink capable of dyeing an intermediate film made of a thermoplastic resin and used in a laminated glass sheet; (b) applying over the printed pattern surface of the transfer sheet thus obtained and/or the surface of the intermediate film, a solvent composition capable of softening to some extent the vehicle of the printing ink and the intermediate film; (c) superposing the surface of the printed pattern over the surface of the intermediate film through the solvent-composition-coated surface and then pressing them against each other at a low temperature less than the glass transition point of the intermediate film, thereby transferring and impregnating the printed pattern over and into the surface of the intermediate film; and (d) separating the transfer sheet substrate from the intermediate film and drying the intermediate film, thereby obtaining a decorative intermediate film for use in a laminated glass sheet. When the decorative intermediate film manufactured through the above-described steps is laminated between glass plates, no air bubbles remain and a uniform coloring effect can be attained so that the glass products having an attractive outer appearance can be obtained.