Multi-layer products comprising acrylate containing coatings
View Patent ↗The present invention relates to a method for producing a multi-layer product comprising a) a substrate containing at least one thermoplastic substrate layer and b) at least one protective layer made of a coating composition comprising compounds with at least two functional groups, characterized in that the protective layer(s) are/is applied inline after the production of the substrate containing the substrate layer.
1. A method of producing a multi-layer product comprising a) a substrate comprising at least one substrate layer and b) at least one protective layer, wherein the substrate layer(s) comprise a thermoplastic polymer, and the protective layer(s) is a coating composition obtained from
A. 30 to 80% by weight of one or more compounds selected from the group consisting of compounds which possess a molar mass of more than 450 g/mol and possess at least two functional groups that react by exposure to actinic radiation with ethylenically unsaturated compounds, with polymerization, and which have no isocyanate groups and wherein the one or more compounds is/are selected from urethane acrylates, which have at least one allophanate group, hexamethylene diisocyanate (HDI) trimer group, biuret group, uretdione group and/or isocyanurate group in the molecule;
B. 15 to 50% by weight of reactive diluents comprising at least two ethylenically unsaturated groups;
C. 0 to 50% by weight of one or more compounds selected from the group consisting of isocyanates having at least one ethylenically unsaturated double bond in the molecule,
D. 0.01 to 10% by weight of light stabilizers based on a triazine derivative;
E. 1 to 10% by weight of photoinitiators; and
F. further coatings additives;
wherein the amount of all of the aforementioned components used in the coating composition being 100% by weight, and the coating composition, following application, being cured by actinic radiation to form a thermoset protective layer, and wherein the protective layer(s) is/are applied in-line directly following the production of the substrate comprising the substrate layers and has an extrusion rate of 1 to 7 m/min.
2. The method according to claim 1 , wherein the substrate layer(s) are produced by (co)extrusion.
3. The method according to claim 1 , wherein the protective layer(s) are applied by knifecoating, pouring or rolling.
4. The method according to claim 1 , wherein the substrate, before the application of the protective layer(s), possesses a temperature of 60-90° C.
5. The method according to claim 4 , wherein the extrusion rate is 1 to 2.5 m/min.
6. The method according to claim 1 , wherein the coated substrate, in the course of curing with actinic radiation with a UV cure dose of 500 to 4000 mJ/cm 2 , does not exceed a temperature of 90° C.
7. The method according to claim 1 for producing films and sheets.
8. The method according to claim 7 , wherein the sheets are solid sheets or sandwich sheets.
9. The method according to claim 8 , wherein said sandwich sheets have 2 to 8 struts.
10. The method according to claim 1 , wherein the coating is free from solvent residues.
11. The method according to claim 1 , wherein the thermoplastic polymers of the substrate layer(s) are selected from the group consisting of poly(meth)acrylates, homopolycarbonates, copolycarbonates, thermoplastic polyestercarbonates, and combinations thereof.