Aqueous oligomer / polymer emulsion with cationic functionality

1. An aqueous emulsion comprising at least a covalently bound vinyl oligomer and vinyl polymer, wherein said vinyl oligomer comprises 5 to 85 mol % of vinyl monomers bearing quaternary ammonium ion functional groups and is obtained by a controlled radical polymerisation of at least one vinyl monomer via a reversible addition-fragmentation chain transfer mechanism in solution in the presence of a control agent and a source of free radicals; wherein said vinyl polymer is obtained by radical emulsion polymerisation of vinyl monomers in the presence of the vinyl oligomer; wherein the weight % ratio of vinyl oligomer to vinyl polymer is in the range of from 0.5:99.5 to 65:35.

2. An aqueous emulsion comprising at least a covalently bound vinyl oligomer and vinyl polymer, wherein said vinyl oligomer comprises 5 to 85 mol % of vinyl monomers bearing quaternary ammonium ion functional groups and is obtained by a controlled radical polymerisation of at least one vinyl monomer via a reversible addition-fragmentation chain transfer mechanism in the presence of a control agent and a source of free radicals; wherein said vinyl polymer is obtained by radical emulsion polymerisation of vinyl monomers in the presence of the vinyl oligomer.

3. An aqueous emulsion according to claim 1 wherein the vinyl oligomer is a block copolymer comprising at least a block [A] comprising an ethylenically unsaturated monomer bearing quaternary ammonium ion and / or quaternisable amine functional groups and optionally other ethylenically unsaturated monomers; and a block [B] comprising ethylenically unsaturated monomers selected from the group consisting of acrylates, methacrylates or vinyl monomers; and optionally a third block or more.

4. An aqueous emulsion according to claim 1 comprising:

a) 10 to 100 wt % of covalently bound vinyl oligomer polymer;

b) 0 to 40 wt of free vinyl oligomer;

c) 0 to 90 wt % of free vinyl polymer;

wherein a)+b)+c) add up to 100%.

5. An aqueous emulsion according to claim 1 wherein the weight % ratio of vinyl oligomer to vinyl polymer, whether covalently bound or free, is in the range of from 0.5:99.5 to 65:35.

6. An aqueous emulsion according to claim 1 wherein the Tg of the vinyl oligomer is in the range of from −100° C. to 0° C.

7. An aqueous emulsion according to claim 1 where the vinyl oligomer has a number average molecular weight Mn≦50,000 g/mol.

8. An aqueous emulsion according to claim 1 wherein the vinyl oligomer is a block copolymer.

9. An aqueous emulsion according to claim 1 where the covalently bound vinyl oligomer polymer has a weight average molecular weight≧20,000 g/mol.

10. An aqueous emulsion according to claim 1 where the vinyl polymer has a calculated Tg≧0° C.

11. An aqueous emulsion according to claim 1 , said emulsion comprising a vinyl oligomer in the form of a block copolymer and a vinyl 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 in solution in the presence of a control agent and a source of free radicals; and wherein the block copolymer comprises:

5 to 90 wt % of block [A] comprising:

i) 10 to 100 mol % of ethylenically unsaturated monomers bearing quaternary ammoniumiun ion functional groups;

ii) 0 to 90 mol % of ethylenically unsaturated monomers bearing water-dispersing or potentially water-dispersing functional groups;

iii) 0 to 50 mol % of C 1 to C 18 alkyl (meth)acrylates and/or styrenic monomers;

iv) 0 to 10 mol % of ethylenically unsaturated monomers different from those from i), ii) and iii);

where i), ii), iii) and iv) add up to 100 mol %, and

10 to 85 wt % of block [B] comprising:

i) 0 to 10 mol % of ethylenically unsaturated monomers bearing quaternary ammonium ion functional groups;

ii) 0 to 5 mol % of ethylenically unsaturated monomers bearing water-dispersing or potentially water-dispersing functional groups;

iii) 50 to 100 mol % of C 1 to C 18 alkyl (meth)acrylates and/or styrenic monomers;

iv) 0 to 50 mol % of ethylenically unsaturated monomers different from those from i), ii) and iii);

where i), ii), iii) and iv) add up to 100 mol %; and

wherein vinyl polymer [P] is prepared by radical emulsion polymerisation of vinyl monomers in the presence of blocks [A] x [B] y wherein vinyl polymer [P] comprises:

i) 0 to 5 wt % of ethylenically unsaturated monomers bearing quaternary ammonium ion functional groups;

ii) 0 to 5 wt % of ethylenically unsaturated monomers bearing water-dispersing or potentially water-dispersing functional groups;

iii) 40 to 100 wt % of C 1 to C 18 alkyl (meth)acrylates and/or styrenic monomers;

iv) 0 to 60 wt % of ethylenically unsaturated monomers different from those from i), ii) and iii);

where i), ii), iii), and iv) add up to 100 wt %;

where [A] has an average degree of polymerisation x, where x is an integer in the range of from 3 to 80;

where [B] has an average degree of polymerisation y, where y is an integer ≧3.

12. An aqueous emulsion according to claim 1 wherein the control agent is selected from the group consisting of dithioesters, thioethers-thiones, trithiocarbonates, dithiocarbamates, xanthates and mixtures thereof.

13. An aqueous emulsion comprising a substantially insoluble vinyl oligomer in the form of a block copolymer comprising 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 in solution in the presence of a control agent and a source of free radicals; and wherein the block copolymer comprises:

5 to 90 wt % of block [A] comprising:

i) 10 to 100 mol % of ethylenically unsaturated monomers bearing quaternary ammonium ion functional groups;

ii) 0 to 90 mol % of ethylenically unsaturated monomers bearing water-dispersing or potentially water-dispersing functional groups;

iii) 0 to 50 mol % of C 1 to C 18 alkyl (meth)acrylates and/or styrenic monomers;

iv) 0 to 10 mol % of ethylenically unsaturated monomers different from those from i), ii) and iii);

where i), ii), iii) and iv) add up to 100 mol %, and

10 to 85 wt % of block [B] comprising:

i) 0 to 10 mol % of ethylenically unsaturated monomers bearing quaternary ammonium ion functional groups;

ii) 0 to 5 mol % of ethylenically unsaturated monomers bearing water-dispersing or potentially water-dispersing functional groups;

iii) 50 to 100 mol % of C 1 to C 18 alkyl (meth)acrylates and/or styrenic monomers;

iv) 0 to 50 mol % of ethylenically unsaturated monomers different from those from i), ii) and iii);

where i), ii), iii) and iv) add up to 100 mol %;

where [A] has an average degree of polymerisation x, where x is an integer in the range of from 3 to 80;

where [B] has an average degree of polymerisation y, where y is an integer ≧3.

14. An aqueous emulsion according to claim 1 additionally comprising a polymer [Q], wherein the solids content of the vinyl oligomer polymer is ≧1 wt % and ≦35 wt % based on total solids content of vinyl oligomer polymer and polymer [Q] together.

15. A process for preparing an aqueous emulsion according to claim 1 comprising the following steps:

1. synthesis in a solvent by means of a RAFT radical polymerisation process of an vinyl oligomer;

2. optional removal of the control agent before, during or after dispersing said vinyl oligomer in water;

3. optional removal of the solvent from said vinyl oligomer;

4. dispersion of said vinyl oligomer in water optionally containing monomers, by adding either water to the vinyl oligomer or adding the vinyl oligomer to water, optionally using surfactants;

5. optional removal of solvent from the vinyl oligomer dispersion (if solvent is still present from step 4.);

6. performing an emulsion polymerisation process of monomers in the presence of the vinyl oligomer dispersion prepared in step 4 and or step 5 to obtain vinyl polymer.

16. A coating having a permanent cationic surface comprising an aqueous emulsion according to claim 1 .

17. An antimicrobial agent comprising an aqueous emulsion according to claim 1 .

18. An antimicrobial surface obtained by coating a surface of a substrate with an aqueous emulsion according to claim 1 .

19. An antistatic surface obtained by coating a surface of a substrate with an aqueous emulsion according to claim 1 .

20. An antibleeding coating comprising an aqueous emulsion according to claim 1 .

21. A substrate coated with a primer coating comprising an aqueous emulsion according to claim 1 and at least one top coating.