Adhesion to plastic with block copolymers obtained using RAFT

摘要

An aqueous coating composition (which optionally can coat plastic substrates) the composition comprising a block copolymer and a polymer P; where the block copolymer comprises at least blocks [A]x[B]y; where at least block [A] is obtained by a controlled radical polymerization of at least one ethylenically unsaturated monomer via a reversible addition-fragmentation chain transfer (RAFT) mechanism (optionally in solution in the presence of a control agent and a source of free radicals); and wherein block [A] comprises 20 to 100 mol % of ethylenically unsaturated monomer units bearing water-dispersing functional groups; wherein block [B] comprises 20 to 100 mol % of ethylenically unsaturated monomer units bearing plastic adhesion promoting functional groups; and wherein polymer P is prepared in the presence of blocks [A]x[B]y. The compositions may be used to coat plastic substrates, foam; surfaces having low surface energy, hydrophobic substrates and/or polyolefins.

主权项

1. A process for preparing an aqueous coating composition to coat polyolefinic substrates, the coating composition comprising a block copolymer and a polymer P; wherein the block copolymer comprises at least blocks [A]x[B]y, wherein the process comprises obtaining at least block [A] by controlled radical polymerisation via a reversible addition-fragmentation chain transfer (RAFT) mechanism of at least one ethylenically unsaturated monomer;
wherein block [A] comprises: i) 0 to 50 mol % of ethylenically unsaturated monomer units bearing crosslinking functional groups; ii) 20 to 100 mol % of ethylenically unsaturated monomer units bearing water-dispersing functional groups; iii) 0 to 50 mol % of ethylenically unsaturated monomers units selected from linear or branched C1 to C8 alkyl (meth)acrylate monomers; iv) 0 to 5 mol % of ethylenically unsaturated monomer units bearing plastic adhesion promoting functional groups; and v) 0 to 10 mol % of ethylenically unsaturated monomers units different from those from i), ii), iii)+iv); where i), ii), iii), iv)+v) add up to 100%; block [A] has an average degree of polymerisation x, where x is an integer from 3 to 80; and wherein block [B] comprises: i) 0 to 5 mol % of ethylenically unsaturated monomer units bearing crosslinking functional groups; ii) 0 to 15 mol % of ethylenically unsaturated monomer units bearing water-dispersing functional groups; iii) 0 to 50 mol % of ethylenically unsaturated monomers units selected from linear or branched C1 to C8 alkyl (meth)acrylate monomers; iv) 20 to 100 mol % of ethylenically unsaturated monomer units bearing plastic adhesion promoting functional groups; and v) 0 to 10 mol % of ethylenically unsaturated monomers units different from those from i), ii), iii)+iv); where i), ii), iii), iv)+v) add up to 100%; block [B] has an average degree of polymerisation y, where y is an integer >10, where y>x; and wherein the process further comprises obtaining the polymer P by conducting, in the presence of the block copolymer, emulsion polymerisation of emulsion polymerization monomers, wherein polymer P comprises: i) 0 to 20 wt % of ethylenically unsaturated monomer units bearing crosslinking functional groups; ii) 0 to 15 wt % of ethylenically unsaturated monomer units bearing water-dispersing functional groups; iii) 50 to 100 wt % of ethylenically unsaturated monomers units selected from linear or branched C1 to C8 alkyl (meth)acrylate monomers; iv) 0 to 50 wt % of ethylenically unsaturated monomer units bearing plastic adhesion promoting functional groups; and v) 0 to 10 mol % of ethylenically unsaturated monomers units different from those from i), ii), iii)+iv); where i), ii), iii), iv)+v) add up to 100% and wherein at least 20 wt % of polymer P is covalently bonded to the block copolymer, and wherein component iv) of Block [B] comprises at least 50 mol % of isobornyl (meth)acrylate.