CEMENT HARDENING RETARDER AND CEMENT HARDENING RETARDING SHEET

摘要

PROBLEM TO BE SOLVED: To obtain a cement hardening retarder capable of manifesting a high ability to retard the hardening for a long period and forming a decorative pattern on the surface of a concrete product with a good accuracy according to an aggregate exposed finish method by washing by composing the retarder of a polymer having specific anionic groups and specified hydrophilic segments. ;SOLUTION: This hardening retarder is composed of a polymer having anionic groups, which are composed of preferably one or more selected from acid anhydride groups, COOH groups and sulfonic acid groups, more preferably groups, represented by formula I and capable of forming chelates for a bivalent metallic ion and hydrophilic segments having preferably a structure represented by formula II [R¹ is a 2-4C alkylene; R² is H, a (cyclo)alkyl, an aryl or an aralkyl; R³ is H or CH₃; X is a 1-10C alkylene or carbonyl; (m) is 0 or 1; (n) is 1-100] [e.g. a copolymer prepared from maleic anhydride and CH₂=CHCH₂O (CH₂CH₂O)₅CH₃].;COPYRIGHT: (C)1998,JPO