CROSSLINKABLE AND FOAMING POLYESTER-POLYURETHANE (HYBRID) RESIN MOULDING COMPOSITIONS, WITH FOAMING CHARACTERISTICS FOR CLOSED MOULD APPLICATIONS
It concerns a crosslinkable and foaming polyester-polyurethane resin moulding composition, comprising : an A component, comprising : A1) at least one poly-functional isocyanate compound, and A2) at least one free radical polymerisation initiator a B component, comprising by weight : B1) 100 parts of at least one polyol resin comprising : - B11) 50 to 80 parts of at least one ethylenically unsaturated polyester polyol - B12) 20 to 50 parts of at least one ethylenically unsaturated monomer, with, B11), being the reaction product of : a) an acid component comprising : a1 ) at least one ethylenically unsaturated diacid, and a2) at least one saturated diacid with a1/a2 molar ratio so varying to have an unsaturation content in B11) from 0.25/1 to 5/1, and, b) a diol component in excess with respect to component a) B2) from 0.01 to 1.1 parts of water, B3) optionally, up to 35% of at least one hydroxy alkyl (meth)acrylate, B4) at least one catalyst of the isocyanate / hydroxyl reaction, B5) at least one accelerator for the free radical initiator decomposition, B6) at least one foam stabiliser, B7) optionally, fillers and/or other additives the said composition being free of any primary or of secondary amine and of any polyol of low Mw chain extender. The invention further relates to a process of preparation and specific uses in light weight articles in sanitary, building or automotive uses.