Patent ID: 8497316

Claim:
A crosslinkable and foaming polyester-polyurethane resin moulding composition, comprising: an A component, comprising: A1) at least one aromatic poly-functional isocyanate compound, and A2) at least one free radical polymerisation initiator; and 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 with hydroxyl value ranging from 80 to 170, and B12) 20 to 50 parts of at least one ethylenically unsaturated monomer, copolymerisable with the unsaturation of said unsaturated polyester polyol, with, said polyester polyol B11), being the reaction product of: a) an acid component comprising: a1) at least one ethylenically unsaturated diacid selected from the group consisting of dicarboxylic acid, dianhydride, anhydride and derivatives thereof, and a2) at least one saturated diacid selected from the group consisting of dicarboxylic acid, dianhydride, anhydride and derivatives thereof, with an a1/a2 molar ratio from 0.25/1 to 5/1, and, b) a diol component in excess with respect to component a) with said polyester polyol B11) having Mn ranging from 700 to 1,250; B2) from 0.35 to 1.1 parts of water as the foam generating component, B3) optionally, at least one hydroxy alkyl (meth)acrylate in an amount up to 35% by weight, with respect to the unsaturated monomers B12+B3, B4) at least one catalyst of an isocyanate/hydroxyl reaction, B5) at least one accelerator for free radical initiator decomposition, B6) at least one foam stabiliser, B7) optionally, a filler, other additive or both, with, said composition being free of any primary or secondary amine, any polyol having Mw lower than 200, and any other polyurethane chain extender, and with a ratio in equivalents of water to a total of reactive hydroxyls being lower than 0.30.