| 摘要 |
PROBLEM TO BE SOLVED: To enable use of an inorganic material having insufficient plasticity as a roofing tile raw material and to reduce weight of the tile while maintaining its strength by mixing a gel of water-swellable water absorbing resin (component (a)) contg. absorbed water with a roofing tile raw material, forming the resulting mixture into a formed body and firing the formed body, in the manufacture. SOLUTION: In this manufacture, the component (a) used has a 100 to 1,000g/g water absorbency with respect to pure water and is a powdery or particulate material having a 5 to 550μm average particle size, and also preferably, the gel used of the component (a) has 10,000 to 50,000dyne/cm<2> gel strength. The component (a) is obtained by subjecting e.g. starch or cellulose, a water-soluble monomer having a hydrophilic group such as carboxyl or sulfonic acid group and/or a monomer capable of becoming water-soluble by hydrolyzing it and a crosslinking agent, each of which is used as an essential polymerization reactant, to polymerization and, if necessary, further hydrolyzing the resulting polymer. As the roofing tile raw material, clay or a plastic ceramic powder can be used and, moreover, a nonplastic material or low plasticity material, each of which is unsuitable for manufacturing a roofing tile, (such as gairome clay (occurs in Japan), silica sand or waste incineration ash), alone or as a mixture of it with another plastic material, can also be used. |
