摘要 |
PROBLEM TO BE SOLVED: To provide a highly dispersible, highly hydrophobic silica powder and its manufacturing process. SOLUTION: The silica powder has a degree of hydrophobicity to water of≥95%, preferably≥98%, a degree of hydrophobicity to a methanol solution of≥70%, preferably≥76%, and a particle size distribution comprising≥10% particles falling within a particle size range of 10-70μm and≤2% particles outside this range. The treated powder is manufactured by performing e.g. primary surface treatment using a silicone oil treatment agent, disintegrating and secondary surface treatment using an alkylsilazane treatment agent and adjusting the condition for each treatment step so that the powder achieves the hydrophobicity and the particle size distribution profile. COPYRIGHT: (C)2004,JPO |