Photovoltaic module backsheet comprising polyolefin layers

A photovoltaic module backsheet comprising:

• a functional layer located at a first face of the backsheet and adapted to being positioned adjacent photovoltaic cells of a photovoltaic module;
• a weather-resistant layer located at a second face of the backsheet opposite the first face and adapted to being exposed to air;
• and
• a connecting layer which connects the functional layer to the weather-resistant layer, wherein
• (i) the functional layer comprises a ternary blend which comprises, based on the weight of the functional layer:
• (ia) 5 to 30 wt. % of polypropylene,
• (ib) at least 50 wt. % of polyethylene, and
• (ic) 20 to 40 wt. % of an ethylene methacrylate copolymer;
• and wherein
• (ii) the weather-resistant layer comprises, based on the weight of the weather-resistant layer:
• (iia) at least 50 to at most 95 wt. % of polypropylene;
• (iib) a UV stabilizer;
• (iic) a primary antioxidant which is selected from the group consisting of phenolic antioxidants and aromatic amine antioxidants;
• and
• (iid) a secondary antioxidant which is selected from the group consisting of trivalent phosphorus containing antioxidants and thioether containing antioxidants, wherein
• the primary and secondary antioxidants are each present in a wt. % amount such that a ratio of the wt. % of the primary antioxidant to the wt. % of the secondary antioxidant is from 0.1 to 1.0, and wherein
• (iii) the connecting layer comprises:
• (iiia) at least 50 wt. % to at most 95 wt. % of polyethylene, and
• (iiib) a maleic anhydride grafted polyolefin, wherein
• the backsheet is free of fluorinated polymers.