Adhesion to plastic with block copolymers obtained using raft

Abstract

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 polymerisation 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.

1 . A process for preparing an aqueous coating composition comprising a block copolymer and a polymer P; wherein the block copolymer comprises at least blocks [A] x [B] y , where at least block [A] is obtained by a controlled radical polymerisation of at least one ethylenically unsaturated monomer via a reversible addition-fragmentation chain transfer (RAFT) mechanism;
 where 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 C 1  to C 8  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;   where 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 C 1  to C 8  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   where polymer P is obtained in the presence of the block copolymer by an emulsion polymerisation process, and 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 C 1  to C 8  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%.   
     
     
         2 . A process according to  claim 1 , where block [A] is obtained and/or obtainable by a controlled radical polymerisation of at least one ethylenically unsaturated monomer via a reversible addition-fragmentation chain transfer mechanism in solution in the presence of a control agent and a source of free radicals. 
     
     
         3 . A process according to  claim 2 , in which the aqueous coating composition is capable of being applied to plastic substrates to form a coating thereon. 
     
     
         4 . A process according to  claim 1 , where block [B] is obtained and/or obtainable by a controlled radical polymerisation of at least one ethylenically unsaturated monomer via a reversible addition-fragmentation chain transfer mechanism in solution in the presence of a control agent and a source of free radicals. 
     
     
         5 . A process according to  claim 1 , wherein the ethylenically unsaturated monomer units bearing plastic adhesion promoting functional groups are selected from the group consisting of C 6  to C 20  (preferably C 6  to C 15 ) optionally substituted alkyl, cyclo alkyl and or aryl(meth)acrylate monomers, styrenic monomers, C 6  to C 20  (preferably C 6  to C 15 ) optionally substituted alkyl(meth)acrylamide monomers, vinylic monomers and mixtures thereof. 
     
     
         6 . A process according to  claim 1 , where, when the substrate is polyolefinic, then component iv) of Block [B] comprises at least 50 mol % of isobornyl(meth)acrylate. 
     
     
         7 . A process according to  claim 1 , wherein the control agent is selected from the group consisting of dithioesters, thioethers-thiones, trithiocarbonates, dithiocarbamates, xanthates and mixtures thereof. 
     
     
         8 . A process according to  claim 1  where polymer P is at least partially grafted to blocks [A][B]. 
     
     
         9 . An aqueous coating composition obtained and/or obtainable by a process as claimed in  claim 1 . 
     
     
         10 . An aqueous coating composition as claimed in  claim 9 , which is capable of being applied to plastic substrates to form a coating thereon. 
     
     
         11 . A mixture of i) block copolymer comprising at least blocks [A] x [B] y , and ii) polymer P; where said mixture is obtained and/or obtainable by a process as claimed in  claim 1 . 
     
     
         12 . A block copolymer-polymer comprising as components thereof i) block copolymer comprising at least blocks [A] x [B] y  and ii) polymer P, where said blockcopolymer-polymer is obtained and/or obtainable by a process as claimed in  claim 1 . 
     
     
         13 . A coating obtained and/or obtainable from a coating composition as claimed in  claim 9  and/or block copolymer-polymer. 
     
     
         14 . A substrate and/or article coated with a coating as claimed in  claim 13 . 
     
     
         15 . A coated substrate and/or coated article as claimed in  claim 14 , where the substrate and/or article comprises hydrophobic plastic. 
     
     
         16 . A method of coating a substrate and/or article comprising the steps of
 i) applying a coating composition as claimed in  claim 9  and/or block copolymer-polymer to the substrate and/or article; and   ii) drying the substrate and/or article to form a coating thereon.   
     
     
         17 . A method as claimed in  claim 16 , where the substrate and/or article comprises hydrophobic plastic. 
     
     
         18 . A coated substrate and/or coated article obtained and/or obtainable by a method as claimed in  claim 16 . 
     
     
         19 . Use of a coating composition as claimed in  claim 9  and/or block copolymer-polymer to coat a substrate and/or article. 
     
     
         20 . Use of a coating composition as claimed in  claim 9  and/or a substrate and/or article to provide coatings on at least one material selected from the group consisting of:
 plastic substrates 
 foams; 
 surfaces having low surface energy; 
 hydrophobic substrates; 
 polyolefins; 
 any combinations thereof; and 
 any mixtures thereof. 
 
     
     
         21 . A use as claimed in  claim 20 , where the coating is applied to at least one article selected from the group consisting of:
 vehicles;   consumer electronic articles;   furniture;   household articles,   biomedical articles,   any combinations thereof and   any mixtures thereof.   
     
     
         22 . A method of manufacture of a coating composition as claimed in  claim 9  and/or a substrate and/or article for the purpose of being used in at least one of the applications.