| 摘要 |
Provided is an inexpensive solar cell rear surface protective sheet having flame-retardant properties that satisfy the UL-1703 spread of flame test, and excellent long-term resistance to moist heat and long-term resistance to outdoor weather. This solar cell rear surface protective sheet is equipped with a film-thickness (t), weather-resistant, flame-retardant resin layer (1), a plastic film (2), and an easy-adhesion layer (3). Therein, the weather-resistant, flame-retardant resin layer (1) comprises the surface on one side of the solar cell rear surface protective sheet, while the easy-adhesion layer (3) comprises the surface on the other side thereof. The weather-resistant, flame-retardant resin layer (1) contains: a phosphorous-based flame retardant (A) selected from a group consisting of a phosphazene compound, a phosphinic acid compound, and a melamine (poly)phosphate; and a weather-resistant resin (B) selected from a group consisting of a fluorine resin, a urethane resin, and a polyester resin. The film thickness (t) of the weather-resistant, flame-retardant resin layer (1) is set at 2.5-20% of the total thickness, while the total phosphorous concentration deriving from the phosphorous-based flame retardant (A) contained in the weather-resistant, flame-retardant resin layer (1) is set at 2.1-14.2 wt%. |
