| 摘要 |
1370987 Hydrophobic materials RHONEPROGIL 25 July 1972 [26 July 1971] 34768/72 Heading C1A Porous, divided or colloidal materials, e.g SiO2 gel, having surface OH groups are rendered hydrophobic by treatment with a compound of the formula R-Si-X, where R is an organic radical having a M.W. of at least 150 and containing a hydrophilic substituent, and X is a radical or atom capable of reacting with the OH groups to groups of the formula -O-Si-R. The R group may have a M.W. of up to 4000. The Si-containing compound may be prepared by the addition reaction of a compound containing a terminal vinyl or allyl group and a hydrophilic substituent with a silane. Alternatively it may be prepared by copolymerizing a vinyl monomer having a hydrophilic substituent with an unsaturated silane. The bodies may be dried before treatment or modified hydrothermally in the presence of NH3. Treatment may be carried out by contacting the bodies with the Si-compound in the vapour or liquid phase, optionally in a solvent, washing with a solvent for the Sicompound, drying and then finally heating to remove any non-bonded Si-compound. The SiO2 gel bodies may be microspheres having 0�5-4 OH groups per 100 �<2>, a diameter of 100-200 �, a surface area of 6-130 m.<2>/g., a pore volume of 0�8-1�0 ml./g., and a pore diameter of 108-5200 �. |
