Cement setting retarder and cement setting retarder film

摘要

A cement setting retarder comprising a polyester produced by the reaction of a polycarboxylic acid component containing a polycarboxylic acid having a main chain bearing 2 to 6 carbon atoms (e.g. maleic anhydride) with a polyol component containing a polyhydric alcohol bearing 2 to 4 carbon atoms or a condensate thereof. The unsaturated polyester is usable also as a polymerizable composition containing a polymerization initiator, a polymerizable vinyl monomer, and other components. The setting retarder may comprise particles of a cured unsaturated polyester. A setting retarder sheet can be formed by coating or impregnating a base sheet with a composition containing the retarder and a pressure-sensitive adhesive. It is possible to form patterns on the surface of a concrete product or to conduct exposed-aggregate finish thereon by forming given patterns in the form by using the retarder or sheet, placing a mortar composition thereon, and washing the surface of a set concrete to thereby expose an unset mortar.