Polymer sheet for solar cell, process for production thereof, solar cell backsheet and solar cell module

A method of producing a polymer sheet for a solar cell, the method comprising:

• applying, on a polyester base material, a coating liquid containing a composite polymer which contains, in a molecule, 15% by mass to 85% by mass of siloxane structural units represented by the following Formula (1) and 85% by mass to 15% by mass of non-siloxane-based structural units to form at least one polymer layer, the polyester base material having a carboxyl group content of 15 eq/t or less, a minute endothermic peak temperature Tmeta (° C.) of 220° C. or lower as determined by differential scanning calorimetry, and an average elongation retention ratio of 10% or more as determined after being allowed to stand under the conditions of a temperature of 125° C. and a relative humidity of 100% RH for 72 hours:
• wherein, in Formula (1), each of R1 and R2 independently represents a hydrogen atom, a halogen atom or a monovalent organic group;
• R1 and R2 may be same or different;
• a plurality of R1 and R2 may be same or different;
• and n represents an integer of 1 or more.