| 摘要 |
[Problem] To provide a polyvinyl acetal film with which fine position adjustments during lay-up are easy, which does not contract during lamination, and with which there is no spillage of resin from the end of a member such as a glass plate; and also to provide an interlayer for laminated glass and a sealant for a solar cell, formed from the polyvinyl acetal film, and to provide a solar cell module and laminated glass using the polyvinyl acetal film. [Solution] A polyvinyl acetal film formed using polyvinyl acetal containing 8-30 mass% vinyl alcohol units, wherein the film has a three layer structure in which a core layer (C) is present between two outer skin layers (A, B), and satisfies the following formulas (I)-(III). DeltanMDA>=DeltanMDB (I) DeltanMDB-DeltanMDC>=0.1×10-3 (II) DeltanMDC@0.2×10-3 (III) (In the formulas, DeltanMDA represents the birefringence of the one skin layer (A) in the machine direction, DeltanMDB represents the birefringence of the other skin layer (B) in the machine direction, and DeltanMDC represents the birefringence of the core layer (C) in the machine direction.) |
