Patent ID: 6706805
Filing Date: 2004-03-16
Classification: C04B,C08F

Abstract:
A building material composition, comprisinga) a dry mix suitable for preparing a water-based, settable building material upon addition of water; b) a polyvinyl alcohol protective colloid-stabilized copolymer based on vinyl ester monomers, (meth)acrylic ester monomer(s) and optionally ethylene, in the form of an aqueous dispersion or in the form of a redispersible polymer powder, said copolymer prepared by the process of b)i) in a first step, polymerizing vinyl ester monomer(s) and optionally ethylene and further copolymerizable comonomer(s) in aqueous medium to a conversion of 90 to 100% by weight based on the total weight of polymerizable monomers added in said first step, in the presence of at least one polyvinyl alcohol colloidal stabilizer, wherein ethylene, when present in said first step, is present in an amount of 40 weight percent or less based on the weight of all polymerizable monomers in said first step, b)ii) in a second step, adding and polymerizing one or more (meth)acrylic acid esters, to form a copolymer dispersion, and b)iii) when the copolymer is a redispersible powder, drying said copolymer dispersion.