| 摘要 |
PROBLEM TO BE SOLVED: To solve problems in a production method of silica aerogel and silica xerogel heat insulation materials, in which nano porous materials are formed with water glass 101 as a raw material, that in-process goods build up between production steps and the production process become complicated because curing at 80 degrees for 12 hours is needed in order to grow a gel framework in which silica particles of a tens of nm size are linked.SOLUTION: The production method comprises: obtaining an acidic sol solution; and subsequently adding under stirring a basic aqueous silicic acid solution having pH of 10 to 11 and containing silicic acid particles of a size of several nm to 30 nm. Thereby, silica particles deposit around the added silica particles, which link with each other to speed up a reaction. In a conventional process, 12 hours were necessary for a gel comprising a silica framework is formed by adjusting a main raw material, water glass 101, to be acidic and basic. Post-addition of particles having a desired size can shorten the time required for particle nuclei formation and growth to 2 hours. |
