Spherical micro-porous silica gel and a production process thereof
AssigneeToyo Soda Manufacturing Co., Ltd.
InventorsJunji Arika, Eiji Shiota, Kazuaki Yamamoto
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Abstract
A spherical micro-porous silica gel, which is characterized by having a mean diameter of 3-20 .mu.m, a bulk density of 0.28-0.41 g/cm.sup.3, a pore size of 18,000-100,000 and a specific surface area of 1,000-1,400 m.sup.2 /g and a production process therefor is characterized by employing (a) an aqueous solution containing SiO.sub.2 in which the primary particle diameter is not larger than 6 nm and the molar ratio of SiO.sub.2 to Na.sub.2 O is not larger than 5.5, (b) either stearic acid or a mixture of stearic acid and a non-ionic surface active agent of which HLB ranges from 3.5 to 6.0 as an emulsifier and (c) an organic acid as a gelling agent.
Claims7
A spherical micro-porous silica gel, which is characterized by having a mean diameter of 3-20 .mu.m, a bulk density of 0.28-0.41 g/cm.sup.3, a pore size of 18,000-100,000, and a specific surface area of 1,000-1,400 m.sup.2 /g.
In a process for producing silica gels through gelation of aqueous solution containing SiO.sub.2 which is dispersed in an oil phase as aqueous droplets, the improvement for the production of a spherical micro-porous silica gel having a mean diameter of 3-20 .mu.m, a bulk density of 0.28-0.41 g/cm.sup.3, a pore size of 18,000-100,000, and a specific surface area of 1,000-1,400 m.sup.2 /g, which comprises employing (a) an aqueous solution containing SiO.sub.2 in which the primary particle diameter is not larger than 6 nm and the molar ratio of SiO.sub.2 /Na.sub.2 O is not larger than 5.5, (b) either stearic acid or a mixture of stearic acid and a non-ionic surface active agent of which HLB ranges from 3.5 to 6.0 as an emulsifier and (c) an organic acid as a gelling agent.
Dependencies are inferred from the claim text.