Polyester-acrylic dispersions with reactive diluent based on lactone-containing compounds

摘要

Preparation of aqueous, hydroxy-functional polyester-polyacrylate dispersion involves polymerizing mixture of vinyl monomers in the presence of oligoester(s) prepared from compounds containing lactone groups; mixing polymer with polyester polyol(s) ; and dispersing the resulting polymer mixture in water before or after the addition of a neutralizing agent. The dispersion has a cosolvent content of 0-5 wt.%. Preparation of aqueous, hydroxy-functional polyester-polyacrylate dispersion involves preparing a polymer (P) in a first step by polymerizing a mixture of vinyl monomers (A) that are capable of free-radical copolymerization, in the presence of oligoester(s) (B) prepared from compounds containing lactone groups and having a hydroxyl number of 145-710 mg potassium hydroxide/g, an acid number of =0.5 mg KOH/g solids and an average OH functionality of 2.5-5 mg KOH/g solids; mixing polymer (P) in a second step with polyester polyol(s) (C) having a hydroxyl number of 10-500 mg KOH/g solids and an acid number of greater than 0.5-=30 mg KOH/g solids; and dispersing the resulting polymer mixture in water before or after the addition of a neutralizing agent. The dispersion has a cosolvent content of 0-5 wt.%. Independent claims are also included for: (1) aqueous coating composition comprising the polyester-polyacrylate dispersion; (2) multi-coat coating comprising topcoat obtained by curing the polyester-polyacrylate dispersion; and (3) polyester-polyacrylate dispersion.