Patent ID: 7696265

Claim:
A process for the manufacturing a roof or a face of a building, comprising: constructing said roof from a plastic element which comprises an impact-resistant, thermoplastic plastic, and from 0.01 to 2 wt. % of IR-reflective particles comprising lamellar-shaped carrier pigments coated with a metal oxide, wherein said element is a double-web plate; wherein the plastic element is made by a process comprising: mixing said IR-reflective particles with a melt of a low-viscosity thermoplastic plastic at a temperature of at least 280° C. in a pressure-free, non-shearing zone of a twin-screw extruder to form a pre-mixture comprising from 5 to 40 wt. % of said IR-reflective particles; extruding said pre-mixture; converting said pre-mixture to granulate form or a melt; mixing said granulate or melt of the premixture with a granulate or a melt of a polymethyl methacrylate modified to be impact-resistant to form a plastic mixture wherein said polymethyl methacrylate comprises a polymer matrix and an agent to modify impact resistance; extruding or co-extruding the resultant plastic mixture with a melt of a thermoplastic plastic into an extrudate having a desired shape; and cooling said extrudate.