| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To continuously obtain hollow particles of desired size while preventing generation and aggregation of coarse particles, coarsening of shell compound-coated core particles and formation of aggregates at the stage of coating a core particle surface by a hydrolysis-condensation polymerization reaction of an alkoxide, so that clogging of pore flow paths in a wet particle dispersion device with the coarse particles and aggregates is prevented. <P>SOLUTION: Calcium carbonate fine particles 2 are mixed in ethanol 3 and distilled water 4 and subjected to ultrasonic dispersion (S10), tetraethoxysilane (TEOS) 5, urea 6 and urease 7 are added, and they are stirred by shaking at 25°C (S11), whereby the TEOS 5 is converted to silica by hydrolysis- condensation polymerization and the silica coats a surface of the calcium carbonate fine particles 2. Since ammonia catalyzing the condensation polymerization of the TEOS 5 is gradually generated by decomposition of the urea 6, generation and aggregation of coarse particles and formation of aggregates of shell compound-coated core particles are prevented. The calcium carbonate fine particles 2 are then removed by acid treatment (S16) to thereby obtain hollow particles 1 comprising a silica shell. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
