| 摘要 |
PROBLEM TO BE SOLVED: To improve the extrusion moldability of a cement material and to make the resultant inorg. molding excellent in shape retentivity by using a PVA polymer in combination with a condensation product of an alkali metallic salt of an arom. sulfonic acid and formaldehyde. SOLUTION: A PVA polymer is blended with a condensation product of an alkali metallic salt of an arom. sulfonic acid and formaldehyde and the blend is used as the objective extrusion molding aid. When the polymn. degree of the PVA polymer is >=1,500, particularly >=2,000, good water retentivity and excellent extrusion moldability are ensured. When 0.1-45% monomeric units contg. a hydrophilic functional group other than vinyl alcohol units are incorporated into the PVA polymer, the dispersibility of the PVA polymer in an inorg. material is improved and the extrusion moldability of the inorg. material can be improved. The condensation product, is usually a condensation product of sodium naphthalenesulfonate and formaldehyde. |
