TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The copolymer in layer (B) has the formula (I).R=Si-linked hydrocarbyl (optionally halogenated and/or containing in-chain oxygen);X=1-20C alkylene (optionally with non-adjacent CH 2 groups replaced by O);A, Z=O or NR';R'=H or 1-10C alkyl;Y=1-20C hydrocarbylene (optionally halogenated and/or containing in-chain oxygen);D=hydrocarbylene (optionally substituted with halogen or 1-6C alkyl and optionally with non-adjacent CH2 groups replaced by -O-, -COO-, -OCO- or -OCOO-);n=1-4000;a=at least 1;b, c=0 or 1-1000.This copolymer shows a softening point (Ts) of at least 40 (preferably 100-180) degrees C at atmospheric pressure, i.e. 900-1100 hPa, and a tensile modulus (at 100% elongation at room temperature) of up to 3 N/mm 2.Layer (D) comprises metallic or mineral materials, organic or organosilicon polymers and their mixtures, copolymers or laminates; at least one layer (D) is present.Preferred Method: The third stage (lamination) is carried out at a temperature which is 10-50 degrees C above Ts and at a pressure between 1000 hPa and 20000 hPa. EXAMPLE - Film with a thickness of 0.38 mm (B1) was produced by the chill-roll method from Geniomer 140 (RTM: siloxane copolymer with urea groups; Mw 120000; softening point 125 degrees C), by extrusion through a sheet die at 170 degrees C and 50 kg/hour, using a chill-roll at 15 degrees C and a draw-off speed of 3.5 m/min. A commercial solar cell (polycrystalline silicon; 10 x 10 cm) was completely covered with B1 which was lightly pressed to remove air bubbles and then covered and pressed in the same way with a 0.4-cm layer of AFG Solatex (RTM: low-iron float glass). The sandwich was then heated for 15 minutes at 160 degrees C under a 500-g load to form a composite solar cell. The final laminate showed a current conduction of 94%, compared with 95% for the solar cell plus low-iron glass and 100% for the pure solar cell; it was completely transparent (copolymer film transparency= 99%), with no cracks or breaks in the copolymer/glass joint and no bubbles, and showed a high strength.