| 摘要 |
Aqueous silica sol stabilised against freezing, containing 25 to 50% by weight of SiO2 and 2 to 10% by weight of urea and/or urea derivatives of the general formula
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in which X and Y can be an NH2 or NHR group, and R denotes an alkyl radical having 1 to 4 carbon atoms, and its use in phosphate-based investments in dental technology. |
