Hydrotalkittforbindelser med lavt uraninnhold (u) og fremgangsmÕter ved fremstilling av disse

摘要

Hydrotalcite compounds useful as additives to synthetic resins such as epoxy resins which are used as, in particular, sealant for semiconductor devices such as transister, IC, LSI and the like, which are characterized by having a composition represented by the formula (1) below:; $PTEXTPDATM/PDATHILSBPDAT1\−X/PDAT/SB/HILHILSPPDAT2\+/PDAT/SP/HILPDATAl/PDATHILSBPDATX/PDAT/SB/HILHILSPPDAT3\+/PDAT/SP/HILPDAT(OH)/PDATHILSBPDAT2/PDAT/SB/HILPDATA/PDATHILSPPDAT2\−/PDAT/SP/HILHILSBPDATX/2/PDAT/SB/HILHILITALICPDAT\·m/PDAT/ITALIC/HILPDATH/PDATHILSBPDAT2/PDAT/SB/HILPDATO\ \ (1)/PDAT/PTEXT$ ;in which M^2+ is at least one of Mg^2+ and Zn^2+,;x is a positive number in the range of 0.2≦x≦0.5,;A^2− is at least one of CO₃^2− and SO₄^2−, and;m is a number in the range of 0-2,;and having a uranium (U) content of not more than 10 ppb, an average secondary particle size of not more than about 3 &mgr;m and a BET specific surface area of not more than 30 m²/g.