To obtain a polymer which can be easily converted to a powder redispersible in a neutral medium, as well as in an acidic or alkaline medium, and, by virtue of its excellent compatibility, is suitable as an additive for hydraulic binders and, at the same time, can ensure the strength, softness and water resistance of hydraulic binders.
This polymer comprises: a) a core polymer comprising 80 to 100 wt.% monomer selected from a group of acrylates or, if necessary, a combination of the above monomer with a monomer selected from a group of styrenes and 0 to 20 wt.% ethylenically unsatd. sulfonic acid compd.; and b) a shell polymer comprising 60 to 95 wt.% monomer selected from a group of acrylates or, if necessary, a combination of the monomer described just above with a monomer selected from a group of styrenes and 5 to 40 wt.% ethylenically unsatd. sulfonic acid compd., wherein the content of the sulfonic acid compd. in the shell is larger than the content of the sulfonic acid compd. in the core.
MACHIE UMINSUKII
SHIYUTEFUAN PII
