PRODUCTION OF CERAMIC BUILDING MATERIAL HAVING TORTOISESHELL PATTERN

摘要

PURPOSE:To enable formation of a glazed film of tortoiseshell pattern having different sizes on various ceramic substrates, by using a glassy powder material having a larger coefficient of cubic expansion than that of a ceramic substrate as a spraying material. CONSTITUTION:A glassy powder material is sprayed upon a ceramic substrate having a smaller coefficient of cubic expansion than that of the glassy powder material and a glazed film having a tortoiseshell pattern is formed to give a ceramic building material having a tortoiseshell pattern. Borosilicate glass, lead glass and phosphate glass are used as the glassy powder material. An inorganic ceramic molded article selected from cement block, fiber-reinforced concrete block, various ceramic burnt plates and brick may be used as the ceramic substrate. Preferably the tortoiseshell pattern part of the ceramic building material is subjected to water-repellent treatment with a water repellent material to prevent water permeation. Consequently peeling of the glazed film can be prevented.