Patent ID: 7700671

Claim:
A cement composition for extrusion molding comprising: 100 weight parts of a blend comprising a hydraulic material, an aggregate and a fiber, wherein the fiber comprises pulp; 0.1 to 1.5 weight parts of an extrusion aid; 15 to 25 weight parts of water; and 0.01 to 2.0 weight parts of a copolymer, wherein said copolymer comprises 50 to 99 weight percent of a unit (a) derived from a polyoxyalkylene derivative represented by the following formula (1) wherein R 1 , R 2 and R 3 are each, independently, a hydrogen atom or methyl group, AO comprises an oxyethylene group and an oxypropylene group, a ratio of the oxyethylene group to the oxypropylene group being 90 to 99:10 to 1, R 4 is a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms, q is an integer of 0 to 2, and p is 130-400; 1 to 50 weight percent of a unit (b) derived from maleic anhydride or a dicarboxylic acid represented by the following formula (2) wherein V is —OM 2 or —W-(AO)rR 5 , W is an ether group or imino group, AO is at least one oxyalkylene group having 2 to 4 carbon atoms and may be copolymerized in random or block in the case that two or more different AO are included, R 5 is a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms, M 1 and M 2 each, independently, a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium or an organic ammonium group, and r is 1 to 150; and 0 to 30 weight percent of a unit (c) derived from an additional copolymerizable monomer.