Production of moulded parts, e.g. bumpers or tailgates for cars, involves in-mould plastic injection onto a preformed carrier film coated with a pigmented basecoat and a special, urethane-acrylate based clearcoat

摘要

Moulded parts, especially for cars, are made by an in-mould injection process using a carrier film coated with a pigmented basecoat and a crosslinkable clearcoat based on urethane-(meth)acrylate material with branching points, cyclic units and aliphatic units, which also contains carbamate, biuret, allophanate, urea and/or amide groups : A method for the production of moulded parts, especially for cars, involves (I) making a film (F) with a coating (B) by (1) applying a pigmented coating material (P) to an optionally pretreated surface (T1) of a carrier film (T), (2) applying a crosslinkable coating material (K) which contains a radically-crosslinkable component (KK) and gives a transparent coating (KE) after final crosslinking, and (3) drying and/or partly crosslinking material (K) to give a coating which is not finally crosslinked (KT), (II) placing the film (F) in an open mould, (III) closing the mould, contacting the other side (T2) of the carrier (T) with a fluid or softened plastic material (KM) and allowing the material (KM) to set, (IV) demoulding the part and (V) finally crosslinking the coating (KT). The crosslinkable component (KK) contains oligo- and/or poly-urethane (meth)acrylate(s), shows on average more than 1 ethylenic double bonds per molecule, a number-average mol. wt. (M n) of 1000-10000, a double bond content of 1.0-5.0 mols/1000 g KK and on average more than one branching point per molecule, contains 5-50 wt% cyclic structural units and contains at least one aliphatic structural unit with at least 6 carbons in the chain. Component (KK) also contains carbamate and/or biuret and/or allophanate and/or urea and/or amide groups (C/B/A/U/A groups), and (P) is a solvent-containing or aqueous coating material. Independent claims are also included for (1) film (F) with a coating (B), obtained by the above method (2) moulded parts consisting of material (KM) coated with film (F) .