| 摘要 |
<p>Stabilised sodium percarbonate mfr - by precipitating in presence of silicate, then increasing the silicate content of the mother liquor. Prepn. of sodium percarbonate (I) comprises precipitating (I) from a soln. (pref. of sodium carbonate and hydrogen peroxide) contg. silicate, to obtain particles with a limited quantity (pref. 0.1-2.0 wt %) of silicate distributed in and through them. Sufficient silicate is then deposited on the surface of the particles to improve their resistance to external contaminants. (I) is stabilised against both its intrinsic instability (e.g due to Fe present in reactants) and instability due to external causes. Loss of active oxygen content, agglomeration and corrosion are prevented. (I) can be stored in bulk, safely for several months or even weeks, e.g. prior to in corporation into detergent compsns. Only small amts. of stabiliser, and no special appts. are required.</p> |
