Polymer composition comprising a polymer having a gradient polymeric morphology

1. An aqueous composition comprising water and no more than 15 wt. % of co-solvent based on the weight of the below-named components (A) and (B), in admixture with components:

(A) 70 to 90 wt. % of a vinyl polymer(s) having a gradient polymeric morphology; and

(B) 10 to 30 wt. % of at least one polymer not having a gradient polymeric morphology;

wherein component (A) is separately prepared and thereafter blended with component (B) and components (A) and (B) add up to 100%.

2. An aqueous composition according to claim 1 wherein component (A) is obtained by the polymerisation of at least a first monomer feed and a different second monomer feed.

3. An aqueous composition according to claim 2 wherein component (A) is obtained from a process comprising introducing a first monomer feed to a reactor, where the first monomer feed continually varies in its composition due to the addition of a different second monomer feed to the first monomer feed and polymerising the monomers introduced into the reactor.

4. An aqueous composition according to claim 2 wherein component (A) is obtained from a process comprising simultaneously introducing a first monomer feed and a different second monomer feed into a reactor where the rate of introduction of the first monomer feed varies with respect to the rate of introduction of the second monomer feed and polymerising the monomers introduced into the reactor.

5. An aqueous composition according to claim 2 where the weight ratio of the first monomer feed to the different second monomer feed is in the range of from 70:30 to 30:70.

6. An aqueous composition according to claim 5 where either the first monomer feed and/or the second monomer feed comprises composition (a):

i) 10 to 90 wt. % of CH 2 ═R 1 COOR 2 where R 1 is H or methyl and R 2 is optionally substituted alkyl or cycloalkyl of 4 to 20 carbons atoms;

ii) 0 to 40 wt. % of styrene;

iii) 0 to 15 wt. % of acid functional vinyl monomer(s);

iv) 0 to 10 wt. % of crosslinking functional vinyl monomer(s);

v) 0 to 5 wt. % of chain transfer agent(s)

vi) 0 to 20 wt. % of vinyl monomer(s) not in i) to vi)

where i)+ii)+iii)+iv)+v)+vi) add up to 100%;

and wherein said second monomer feed is different from said first monomer feed.

7. An aqueous composition according to claim 5 where either the first monomer feed and/or the second monomer feed comprises composition (b):

i) 10 to 90 wt. % of CH 2 ═CR 1 —COOR 2 where R 1 is H or methyl and R 2 is optionally substituted alkyl or cycloalkyl of 1 to 20 carbon atoms;

ii) 0 to 40 wt. % of styrene;

iii) 2 to 20 wt. % of acid functional monomer(s);

iv) 0 to 30 wt. % of crosslinking functional monomer(s);

v) 0 to 10 wt. % of chain transfer agent(s);

vi) 0 to 20 wt. % of vinyl monomer(s) not in i) to vi);

where i)+ii)+iii)+iv)+v)+vi) add up to 100%; and

wherein said second monomer feed is different from said first monomer feed.

8. An aqueous composition according to claim 1 wherein component (A) is obtained from a seeded polymerisation process.

9. An aqueous composition according to claim 6 or claim 7 where component (B) is selected from the group comprising:

(i) vinyl polymer(s) having a Tg≧50° C. and a particle size≦150 nm;

(ii) water-dissipatable polyurethane(s);

(iii) UV curable polymer(s); and

(iv) autoxidisably crosslinkable polymer(s).

10. A coating composition comprising an aqueous composition according to claim 1 .

11. A coating obtained from an aqueous composition according to claim 1 .

12. An adhesive obtained from an aqueous composition according to claim 1 .

13. A substrate coated with an aqueous composition according to claim 1 .

14. An aqueous composition according to claim 1 containing not more than 1% by weight of co-solvent based on the weight of components (A) and (B).

15. An aqueous composition according to claim 14 having a solids content of about 20 to 60% by weight.