Patent ID: 11965050
Assignee: COVESTRO (NETHERLANDS) B.V.
Field: Macromolecular chemistry, polymers (Chemistry)
Classification: CPC C | IPC C

Claim 0:
1. A waterborne dispersion comprising
(A) polymer P;
(B) amphiphilic block copolymer obtained with a controlled radical polymerization process and comprising at least blocks [A] and [B], whereby
block [A] comprises ethylenically unsaturated monomer(s) bearing water-soluble and/or water-dispersible functional groups (monomer(s) (i)), and
block [B] comprises ethylenically unsaturated monomer(s) different from monomer(s) (i) (monomer(s) (ii)); and

(C) crosslinker,
wherein the polymer P is crosslinkable and comprises ethylenically unsaturated monomer(s) bearing crosslinkable functional groups different from monomer(s) (i) and monomer(s) (ii) (monomer(s) (iii)) in an amount of from 2 to 7.5 wt. %, based on the total weight of monomers used to prepare the polymer P,
the amount of block copolymer is from 3 to 15 wt. %, based on the total weight of monomers used to prepare the block copolymer and polymer P and the weight average molecular weight of the block copolymer is in the range of from 7,000 to 50,000 g/mol;
and wherein
the calculated glass transition temperature of the block copolymer is from 50 to 150° C., the acid value of a composition consisting of block copolymer and polymer P is from 3 to 16 mg KOH per g of the composition consisting of block copolymer and polymer P,
and wherein
an equivalent molar ratio of crosslinkable functional groups present in the crosslinker to crosslinkable functional groups present in the block copolymer and polymer P is from 0.5 to 1.0, wherein the equivalent molar ratio is calculated by dividing the molar amount of crosslinkable functional groups present in the crosslinker by the molar amount of crosslinkable functional groups present in the block copolymer and polymer P, which molar amounts are calculated from the amount of crosslinkable functional monomers (iii) which are used for preparing the block copolymer and polymer P and from the amount of crosslinker which is added to the coating composition.