Photovoltaic modules with a thermoplastic adhesive layer and method for fabricating the same

摘要

Thermoplastic aliphatic polyurethane with a hardness of 75 Shore A to 70 Shore D, a softening point of 90-150 degrees C and a tensile modulus of 2 MPa is used as the embedding material for solar cells in the middle layer of a photovoltaic module. A photovoltaic module comprises: (A) an outer layer facing the energy source, consisting of glass or impact-resistant, UV-resistant, weathering-resistant, transparent plastic with low water vapor permeability; (B) a synthetic adhesive interlayer with one or more embedded, electrically interconnected solar cells; and (C) a backing layer of glass or weather-resistant plastic with low water vapor permeability. The adhesive in (B) consists of an aliphatic thermoplastic polyurethane with a hardness of 75 Shore A to 70 Shore D, a softening point of 90-150 degrees C and an E' modulus of 2 MPa (by the DMS method), which is the reaction product of: (a) an aliphatic di-isocyanate; (b) Zerewitinoff-reactive polyol(s) with 1.8-3.0 reactive hydrogen atoms on average and a number-average molecular weight (Mn) of 600-10000; and (c) chain-extender polyol(s) with 1.8-3.0 reactive H atoms and an Mn of 60-500, using a mol ratio of (NCO groups):(reactive H atoms) = 0.85-1.2, preferably 0.9-1.1. An Independent claim is also included for a method for the production of a photovoltaic module as described in a vacuum hot press laminator.