| 摘要 |
<p>Glaze, enamel or paint coating is formed on an article containing or consisting of calcareous cement or clay by coating the article with an alkali metal silicate, drying the coating, treating the coating with a hot soln. of an alkaline earth metal salt (which soln. may also contain an alkali metal salt) whereby reaction occurs to convert the coating into silica, and then treating the coated article with hot water or steam at superatmospheric pressure in an autoclave. When the initial alkali metal silicate coating contains a high content of pigment or other additives, the dried coating is itself coated with an alkali metal silicate layer which is free from or has only a low content of additives, before the treatment is continued with the hot salt soln. and the subsequent autoclaving.</p> |
