Patent ID: 7265166

Claim:
An aqueous polymer composition comprising: a) first polymer particles comprising at least one pendant group selected from the group consisting of phosphorus acid groups, phosphorus acid full-ester groups, polyacid sidechain groups, and mixtures thereof; wherein said first polymer particles comprise, based on weight of said first polymer particles: i) from 40 to 100 weight % first hard polymer particles having a glass transition temperature of at least 20° C., ii) from 0 to 60 weight % first soft polymer particles having a glass transition temperature in the range of from −20° C. to 5° C.; and iii) from 0 to 60 weight % first hard-soft polymer particles comprising first soft polymer phase having a glass transition temperature in the range of from −20° C. to 5° C., and first hard polymer phase having a glass transition temperature of at least 20° C.; b) optionally, second polymer particles comprising: i) second soft polymer particles having a glass transition temperature in the range of from −20° C. to 5° C., ii) second hard polymer particles having a glass transition temperature of at least 20° C.; or iii) second hard-soft polymer particles comprising second soft polymer phase having a glass transition temperature in the range of from −20° C. to 5° C., and second hard polymer phase having a glass transition temperature of at least 20° C.; and c) composite particles, wherein each of said composite particles comprises a pigment particle and a plurality of said first polymer particles attached to said pigment particle; wherein said aqueous polymer composition comprises, based on total weight of said first polymer particles and said second polymer particles: a total weight % of said first soft polymer particles, said first soft polymer phase, said second soft polymer particles, and said second soft polymer phase in the range of from 60 to 98 weight %, and a total weight % of said first hard polymer particles, said first hard polymer phase, said second hard polymer particles, and said second hard polymer phase in the range of from 2 to 40 weight %.