Binder composition for powder coatings for use as a top coat in the automotive industry and top-coated automotive substrates

摘要

PCT No. PCT/NL93/00097 Sec. 371 Date Feb. 21, 1995 Sec. 102(e) Date Feb. 21, 1995 PCT Filed May 12, 1993 PCT Pub. No. WO93/23447 PCT Pub. Date Nov. 25, 1993The invention relates to a binder composition for powder coatings for use as a topcoat in the automotive industry. The invention also relates to top-coated automotive substrates. The binder composition includes a polyester containing hydroxyl groups and a polyacrylate containing hydroxyl groups and a blocked hexamethylenediisocyanate trimer. The polyester has a hydroxyl number of between 20 and 100 mg KOH/g resin and an acid number of less than 10 mg KOH/g resin and the polyacrylate has a hydroxyl number of between 40 and 150 mg KOH/g resin and an acid number of less than 20 mg KOH/g resin. The trimer is blocked with 1,2,4-triazole.