Abstract: A cured cement article containing therein an organic polymer treated with an isocyanate compound has a high flexural strength and high water resistance. The cured cement can be prepared by impregnating a cured cement article containing therein a water-soluble polymer or a water-dispersible polymer with an isocyanate compound.

Abstract: A mold material for forming sandmolds for manufacturing metal castings, consisting essentially of an organic binder: 0.4-3.0 percent, a catalyst for curing the organic binder: 0.2-2.0 percent of, a ceramic binder: 0.05-2.0 percent in terms of SiO.sub.2, a catalyst for curing the ceramic binder: 0.05-2.0 percent, and foundry sand: the balance. The mold material can be formed into a sandmold which is excellent in both strength after exposure under a room temperature atmosphere and strength after pouring molten metal thereinto and requires no mold wash or a very small amount of mold wash as obtained by spraying or the like. The mold material may preferably further includes, if required, anti-infiltration fire-proof powder; 0.1-3.0 percent, a high-temperature reinforcing material: 0.1-3.0 percent, a viscosity adjuster: 0.1-2.0 percent, and/or a grannular carbon stabilizer: 0.03-0.5 percent.

Abstract: A lead base coating material containing 0.3-30.0 weight percent, preferably 3.0-4.9 weight percent of tin and 0.001-0.3 weight percent, preferably 0.001-0.02 weight percent in phosphorus content equivalent of at least one selected from the group consisting of phosphorus, tin phosphide, zinc phosphide, antimony phosphide, bismuth phosphide and lead phosphide. The coating material has an excellent wetting to the matrix of a metal plated with the coating material, can promote the formation of an alloy phase between the plating metal matrix and a plating layer, and can also form a plating layer having an improved solderability and an improved corrosion resistivity. The coating material may further contain 0.1-7.0 weight percent of zinc and/or 0.5-35.0 weight percent of antimony, the former imparting sacrificial anodicity to the plating layer, while the latter imparting an enhanced hardness to the plating layer.