| 摘要 |
1499557 Laminated glass HOECHST AG 12 Nov 1975 [13 Nov 1974] 46689/75 Heading B5N [Also in Division C3] Laminated safety glass comprises a plurality of glass plates having disposed therebetween a sheet of a polyvinyl butyral composition comprising (1) 70 to 97À5 weight per cent of a polyvinyl butyral having a viscosity of 60 to 120 cp. in 5% ethanol solution at 23‹ C. and (2) 2À5 to 30 weight per cent of a polyvinyl butyral having a viscosity of 2 to 30 cp. in 5% ethanol solution at 23‹ C., the ratio of the weight average molecular weight to number average molecular weight, determined by gel permeation chromatography, being no more than 5 : 1 for each polymer, together with 20 to 60 parts by weight per 100 parts of the polyvinyl butyrals of a plasticizer, optional together with a stabilizer and/or adhesion promoter such as a carboxylic acid salt, a fluoride, leicithin or an alkylene urea. |
