Coating composition comprising autoxidisable component

Abstract

There is described (pref. non-adhesive) coating compositions (which may be either water or solvent borne) that comprise an autoxidisable vinyl polymer, the autoxidisable polymer having a vinyl polymer backbone 25% to 75% by wt of the autoxidisable polymer; fatty acid residue 25% to 75% by wt of the autoxidisable polymer; T g from −6O° C. to +2O° C., M w from 3500 to 50000 g/mol; and polydispersity from 2 to 10; the autoxidisable polymer obtained by a process of: (A) polymerising ethylenically unsaturated vinyl monomers comprising: at least one epoxy functional vinyl monomer 15% to 100% by wt total monomers in (A); 0 to 85% of at least one other ethylenically unsaturated vinyl monomer, (preferably other than styrenic monomers) by wt total monomers in (A); (B) reacting the epoxy functional polymer from (A) with fatty acids having an average iodine value from 30 to 250 g I 2 /100 g fatty acid; where composition has: a) a opt. co-solvent content ≦40% by wt of the composition; b) a solids content either ≧30% (aqueous) ≧60% (solvent based) by wt of the composition, the composition as a coating film having a telegraphing value of less than 10 gloss units (difference between an initial smooth gloss minus an initial rough gloss of the film).

1 . A coating composition that comprises an autoxidisable vinyl polymer, said composition being selected from the group consisting of aqueous coating compositions and solvent-based coating compositions, where;
 I) said autoxidisable vinyl polymer has:   i) vinyl polymer backbone in an amount from 25% to 75% by weight of said autoxidisable vinyl polymer;   ii) fatty acid residue in an amount from 25% to 75% by weight of said autoxidisable vinyl polymer;   iii) a T 9  from −60° C. to +20° C.,   iv) a weight average molecular weight (M w ) from 3,500 to 50,000 g/mol; and   v) a PDi from 2 to 10;   II) said autoxidisable vinyl polymer is obtained or obtainable by a process comprising the steps of:   (A) polymerising ethylenically unsaturated vinyl monomers comprising:   i) at least one epoxy functional vinyl monomer in an amount from 15% to 100% by weight of the total monomers in step (A); and   ii) at least one other ethylenically unsaturated vinyl monomer in an amount from 0% to 85% by weight of the total monomers in step (A);   to obtain an epoxy functional vinyl polymer   (B) reacting said epoxy functional vinyl polymer obtained in step (A) with fatty acids having an average iodine value from 30 to 250 g I 2 /100 g fatty acid; and   III) said composition has:   a) optionally a co-solvent content less than or equal to 40% by total weight of said composition;   b1) when aqueous has a solids content greater than or equal to 30% by total weight of said aqueous composition;   b2) when solvent-based has a solids content greater than or equal to 60% by total weight of said solvent-based composition; and   IV) said composition when in the form of the film has a telegraphing value of less than 10 gloss units,   where the telegraphing value is the difference between an initial smooth gloss value minus an initial rough gloss value of the film, where   the initial smooth gloss value is the gloss when the film is cast on smooth PVC (R z =1 μm [±0.25 μm]);   the initial rough gloss value is the gloss when the film is cast on rough PVC (R z =25 microns [μm] [±5 μm]); and where   each film has a dry film thickness of 52 μm [±6 μm]; and   each initial gloss value is measured at a 20° angle, one day (24 hours) after the film has been cast.   
     
     
         2 . A coating composition according to  claim 1 , which is a non-adhesive composition. 
     
     
         3 . A coating composition according to  claim 1 , in which the epoxy functional vinyl polymer prepared in step (II)(A) has a M n  from 1,500 to 10,000 g/mol. 
     
     
         4 . A coating composition according to  claim 1 , in which the epoxy functional vinyl polymer prepared in step (II)(A) comprises 0 to 1% of acid functional vinyl monomers by weight of the epoxy vinyl functional polymer. 
     
     
         5 . A coating composition according to  claim 1 , in which the epoxy functional vinyl polymer prepared in step (II)(A) comprises less than 5% of hydroxy functional monomer(s) by weight of the epoxy vinyl functional polymer. 
     
     
         6 . A coating composition according to  claim 1 , in which the epoxy functional vinyl polymer prepared in step (II)(A) comprises less than 40% of styrenic monomer(s) by weight of the epoxy vinyl functional polymer. 
     
     
         7 . A coating composition according to  claim 1 , in which the fatty acid residue is substantially free of fatty acid glycidyl esters. 
     
     
         8 . A coating composition according to  claim 1 , which is aqueous. 
     
     
         9 . An aqueous coating composition according to  claim 8 , comprising no more than 13% N-methylpyrrolidone by weight of the total composition. 
     
     
         10 . An aqueous coating composition according to  claim 8 , comprising no more than 13% of nitrogen containing molecules with an evaporation rate <0.1 the molecules being aromatic, heterocyclic or aliphatic primary and secondary di-amines where the weight % of nitrogen is >5% by weight of the molecule. 
     
     
         11 . A coating composition according to  claim 1 , which is solvent based. 
     
     
         12 . A process for obtaining a polymer that contains at least one autoxidisable vinyl polymer where:
 said autoxidisable vinyl polymer is capable of forming a coating composition that when in the form of the film has a telegraphing value of less than 10 gloss units (as defined in  claim 1 );   the process comprising the steps of:   I) polymerising ethylenically unsaturated vinyl monomers comprising:   i) at least one epoxy functional vinyl monomer in an amount from 15% to 100% by weight of the total monomers in step I); and   ii) at least one other ethylenically unsaturated vinyl monomer in an amount from 0% to 85% by weight of the total monomers in step I);   to obtain an epoxy functional vinyl polymer; and   II) reacting said epoxy functional vinyl polymer obtained in step I) with fatty acids having an average iodine value from 30 to 250 g I 2 /100 g fatty acid;   where the resultant autoxidisable vinyl polymer has   i) vinyl polymer backbone in an amount from 25% to 75% by weight of said autoxidisable vinyl group containing polymer;   ii) fatty acid residue in an amount from 28% to 75% by weight of said autoxidisable vinyl polymer;   iii) a T g  from −60° C. to +20° C.,   iv) a weight average molecular weight (M w ) from 3,500 to 50,000 g/mol; and   v) a PDi from 2 to 10.   
     
     
         13 . A polymer obtained and/or obtainable by a process as claimed in  claim 12 . 
     
     
         14 . A coating composition comprising a polymer as claimed in  claim 13 . 
     
     
         15 . A coating obtained and/or obtainable by a coating composition as claimed in  claim 1  and having a telegraphing value (as defined in  claim 1 ) of less than 10 gloss units. 
     
     
         16 . A substrate coated with a coating as claimed in  claim 15 . 
     
     
         17 . A method of coating a substrate comprising the steps of
 i) applying a coating composition as claimed in  claim 1  to a substrate;   ii) drying the substrate to form a coating thereon;   where the coating has a telegraphing value (as defined in  claim 1 ) of less than 10 gloss units.   
     
     
         18 . Use of an autoxidisable vinyl polymer and/or a coating composition as claimed in  claim 1 , for the purpose of obtaining coatings having a telegraphing value (as defined in  claim 1 ) of less than 10 gloss units. 
     
     
         19 . A method of manufacture of an autoxidisable vinyl polymer and/or a coating composition as claimed in  claim 1 , for the purpose of obtaining coatings having a telegraphing value (as defined in  claim 1 ) of less than 10 gloss units.