Waterborne coating composition

Abstract

The present invention generally relates to the field of cross-linkable aqueous vinyl polymer dispersions, to a coating composition comprising said cross-linkable aqueous vinyl polymer dispersions; to a paint formulation comprising said cross-linkable aqueous vinyl polymer dispersions; and to an article coated with the coating composition or the paint formulation. In particular, the present invention provides an aqueous vinyl polymer dispersion PD which comprises the following polymers: —1) an aqueous dispersion of a vinyl polymer P1 obtainable by free radical emulsion polymerization of a monomers mixture comprising: a) 5 to 20 wt % acid functional ethylenically unsaturated monomers M1 or precursors thereof; b) 5 to 25 wt % ethylenically unsaturated monomers M2 containing a polyethylene glycol or monoalkoxy polyethylene glycol moiety; c) up to 90 wt % of non-ionic ethylenically unsaturated monomers M3 other than M1 or M2; d) 0 to 10 wt % ethylenically unsaturated monomers M4 with a functional group for cross-linking after film-formation; e) 0 to 10 wt % of at least one chain transfer agent CTA; where the sum of the wt. % of M1+M2+M3+M4+CTA=100 wt %; —2) an aqueous dispersion or solution of a vinyl polymer P2 obtainable by free radical copolymerization of: a) from 25 to 95 wt % of a ethylenically unsaturated monomers M5 selected from the group of N-vinyl amides with general structure (I) where R1 and R2 are alkyl from C1 to C5 and may be connected to form a ring-structure, preferably N-vinyl pyrrolidone or N-vinyl caprolactam; b) from 5 to 75 wt % of non-ionic ethylenically unsaturated monomers M3′ other than M5; c) from 0 to 5 wt % of ethylenically unsaturated monomers M4′ with a functional group for cross-linking after film-formation; d) from 0 to 10 wt % acid functional ethylenically unsaturated monomers M1′ or precursors thereof; e) from 0 to 5 wt % of at least one chain transfer agent CTA′; where the sum of the wt. % of: M5+M3′+M4′+M1′+CTA′=100 wt %; —3) a film-forming vinyl polymer P3 under the form of an aqueous dispersion comprising: i) from 20 to 60 wt % of a water-soluble or water dispersible crosslinkable vinyl oligomer OL obtained by emulsion polymerizing a monomer mixture comprising: 1) at least one acid functional ethylenically unsaturated monomer M1″; 2) at least one ethylenically unsaturated monomer M4″ with functionality for crosslinking upon film-formation, other than M1″; 3) at least one ethylenically unsaturated monomer M3″ other than M1″ and M2″, and 5) optionally, at least one chain transfer agent CTA″, and ii) from 40 to 80 wt % of a high molecular weight vinyl polymer P4 prepared by emulsion polymerizing, in the presence of the water-soluble or water-dispersible crosslinkable vinyl oligomer OL, a monomer mixture comprising: 1) optionally one acid functional ethylenically unsaturated monomer M1′″; 2) optionally one or more ethylenically unsaturated monomers M4″′ with functionality for crosslinking upon film-formation, other than M1′″; 3) at least one ethylenically unsaturated monomer M3′″ other than M1′″ and MT′ and 4) optionally, one or more multifunctional ethylenically unsaturated monomers for pre-crosslinking, M5′″, preferably in an amount less than 5 wt %, —Where the total weight of film-forming vinyl polymer P3=wt. % of the water-soluble or water dispersible crosslinkable vinyl oligomer OL+wt. % of the high molecular weight vinyl polymer P4=i)+ii)=100 wt % and—Where the total weight of the vinyl polymer in the aqueous vinyl polymer dispersion PD=wt. % of the vinyl polymer P1+wt. % of the vinyl polymer P2+wt. % of the film-forming vinyl polymer P3=100 wt %.

Dependencies are inferred from the claim text.