LAMINATED GLASS HAVING PHOTOCHROMIC COLORED REGION

摘要

PURPOSE:To obtain the laminated glass with the boundary between the colored and uncolored regions kept unclear by providing a concn. gradient around the boundary between the region having a photochromic composition of a transparent support interposed between two transparent supports and the region free of the composition. CONSTITUTION:A polyvinyl butyral sheet 3 and a polyvinyl butyral sheet 4 contg. 0.5wt.% photochromic composition are interposed between the transparent supports 1 of inorg. glass to form the laminated glass. In this case, the tapered sheet 4 is welded to the sheet 3 at the weld zone (B region). When the content of the photochromic composition of the sheet 4 is controlled to an appropriate value (preferably to 0.01-5.0wt.%) and the thickness of the sheet 4 to an appropriate value (preferably to 10-400mum), the visible light transmittance is continuously increased at the region B. Namely, the laminated glass with the photochromic colored region made unclear at the region B is obtained.