SURFACE-TREATED SUBSTRATE, LIGHT-RECEIVING-SIDE PROTECTIVE SHEET INCLUDING SAME FOR SOLAR CELL, AND SOLAR CELL MODULE

摘要

There is provided a surface-treated substrate obtained by forming a cured material layer composed of a resin composition on a surface of a substrate and then treating a surface of the cured material layer composed of the resin composition with a sulfur trioxide-containing gas, wherein the resin composition contains a composite resin (A) obtained by bonding a polysiloxane segment (a1) having a structural unit represented by general formula (1) and/or general formula (2) and a silanol group and/or a hydrolyzable silyl group to a vinyl-based polymer segment (a2) through a bond represented by general formula (3). There are also provided a light-receiving-side protective sheet for solar cells that uses the surface-treated substrate having a sheet shape and a solar cell module. The surface-treated substrate has good long-lasting antifouling properties.