Patent ID: 10688758

Abstract:
The present invention provides an intermediate film for laminated glass which can improve sound insulation. The intermediate film has a layered structure including at least two layers, comprising: a first layer containing a polyvinyl acetal resin and a plasticizer; and a second layer positioned on a first surface of the first layer. In a phase diagram of three values including a degree of acetalization, a degree of acetylation, and a hydroxyl group content of the polyvinyl acetal resin contained in the first layer, the values of the degree of acetalization, the degree of acetylation, and the hydroxyl group content each fall within a region surrounded by a line including four straight lines connecting first, second, third, and fourth coordinates, which respectively have a degree of acetalization:degree of acetylation:hydroxyl group content of 70 mol %:30 mol %:0 mol %, 34 mol %:30 mol %:36 mol %, 94 mol %:0 mol %:6 mol %, and 100 mol %:0 mol %:0 mol %.