Avspaltningsfri polyuretanpulverlakk med lav innbrenningstemperatur

摘要

Polyurethane powder lacquer contains (A) a binder component with a hydroxyl (OH) number of 25-200 and an average molecular weight of 400-10000 (calculated from the functionality and OH content), which is solid below 40 degrees C and liquid above 130 degrees C; (B) a polyaddition component containing uretdione groups and optionally free isocyanate (NCO) groups based on aliphatic and/or cycloaliphatic diisocyanates, which is solid below 40 degrees C and liquid above 125 degrees C; (C) catalyst containing N,N,N'-tri-substituted amidine structures, which contains 12.0-47.0 wt.% amidine (CN2) groups; optionally (D) other known catalysts; and optionally (E) other usual ancillaries and additives. The mixture contains 0.6-1.4 dimeric NCO (uretdione) and free NCO groups in (B) per OH group in (A) and the amount of (C) is 0.05-5 wt.% of the total amounts of components (A) to (E).