| 摘要 |
PURPOSE:To obtain the subject cement composition improved in shape retention by blending an inorganic additive containing cement with ground pulp fibers, an alkyl cellulose and/or hydroxylalkylalkyl cellulose and a formalin condensate of a specific allylsulfonate. CONSTITUTION:100 pts.wt. cement is blended with 10-60 pts.wt. inorganic additive such as silica sand to give an extrusion molding material. Then the molding material is blended with 3-15wt.% ground pulp fibers having 5-20mum diameter and 1-10mm length, 0.2-0.5wt.% alkyl cellulose and/or hydroxylalkylalkyl cellulose such as methyl cellulose or hydroxypropylmethyl cellulose having >=800cps viscosity in 2% aqueous solution at 20 deg.C as a binder and 1/3-2 times as much an anionic surfactant such as formalin condensate of alkyl-substituted or nonsubstituted allylsulfonate as the binder to give a cement composition for extrusion molding. |
