GB720778A - A process of rendering materials hydrophobic - Google Patents

Abstract

The surfaces of materials such as metals, ceramics and glass are rendered hydrophobic by treatment with an aqueous silicone oil emulsion, followed by a thermal treatment. An especially good hydrophobic effect is obtained when using an emulsion of about 0.1 to 1.0 per cent of a methylsilicone oil of a viscosity of about 50 centistokes at 20 DEG C. and thermal treatment at about 250 DEG to 300 DEG C. for half-an-hour. In examples, an emulsion is prepared by dispersing 40 parts of silicone oil (methylpolysiloxane) of viscosity 50 centistokes at 20 DEG C. in 100 parts of water containing 1 part of the polyglycol ether of oleyl alcohol, the emulsion then being diluted with water to a silicone content of 0.5 per cent. Glass plates or flasks are dipped in the diluted emulsion and heated to 300 DEG C. for half an hour.ALSO:The surfaces of materials such as metals, ceramics and glass are rendered hydrophobic by by treatment with an aqueous silicone oil emulsion, followed by a thermal treatment. The process may be applied to glass containers or ampoules intended for the storage of pharmaceutical preparations, especially penicillin. An especially good hydrophobic effect is obtained when using an emulsion of about 0.1 to 1.0 per cent of a methylsilicone oil of a viscosity of about 50 centistokes at 20 DEG C. and thermal treatment at about 250 to 300 DEG C. for half an hour. In Examples, an emulsion is prepared by dispersing 40 parts of silicone oil (methylpolysiloxane) of viscosity 50 centistokes at 20 DEG C. in 100 parts of water containing 1 part of the polyglycolether of oleyl alcohol, the emulsion then being diluted with water to a silicone content of 0.5 per cent. Glass plates or flasks are dipped in the diluted emulsion and heated to 300 DEG C. for half an hour. A comparative table is given showing the effects on the contact angle of water drops with glass plates treated (a) according to the invention, (b) with a solution of a silicone oil in chloroform, and baked at 300 DEG C. for half an hour, (c) with vaporous dimethyldichlorosilane, (d) with a methylphenylsilicone lacquer, and baked at 230 DEG C for one hour, (e) with a silicone grease.ALSO:The surfaces of glass containers or ampoules intended for the storage of pharmaceutical preparations, are rendered hydrophobic by treatment with an aqueous silicone oil emulsion, followed by a thermal treatment. In an example, flasks intended for the storage of penicillin are dipped in a silicone oil emulsion prepared by dispersing 40 parts of silicone oil (methyl-polysiloxane) of viscosity 50 centistopes at 20 DEG C. in 100 parts of water containing 1 part of the polyglycol-ether of oleyl alcohol, and diluting to a silicone content of 0.5 per cent. The flasks are then heated to 300 DEG C for half an hour.