Patent GB-424015-A (GB)
Title: A process of producing a composition of matter for use as a vehicle for other substances
IPC: C01B7/19
Filed: 1933-09-14
Abstract: A silica gel suitable for use as a vehicle for other substances, e.g. in therapeutic or cosmetic preparations, is obtained by introducing silicon fluoride into an aqueous solution of hydrofluosilicic acid having a specific gravity of at least 1,14, separating the gel formed, and washing the gel with water, the washing being discontinued when the gel ceases to have a hydrofluosilicic acid reaction.  The gel contains hydrofluoric acid in adsorptive combination and has disinfectant properties. A high hydrofluoric acid content is obtained by using a hydrofluosilicic acid of a high concentration and operating at a high temperature and vice versa. Temperatures of 0--50 DEG  C. may be employed.  During the reaction, water or steam may be added to keep the concentration of the hydrofluosilicic acid constant. Specification 267,907, [Class 1 (ii)], is referred to.  The Specification as open to inspection under Sect. 91 comprises also the production of a vehicle by reacting fluorine compounds with silicic acid or by associating colloidal silicic acid with fluorine compounds, e.g. complex fluohydroxy salts such as SiF4.2HF.H2O, SiF4.2HF.4H2O, CaF2.2HF.6H2O, TiO2F2.2HF, ZrOF2.H2O, ZrOF2.2HF.2H2O, HSi2O4F, SiO2F2.2HF, and Si(OH)2.F2 (SiO2.2HF).  These vehicles yield hydrofluoric acid when in the presence of moisture.  This subject-matter does not appear in the Specification as accepted.ALSO:A silica gel suitable for use as a vehicle for other substances, e.g. in therapeutic or cosmetic preparations, is obtained by introducing silicon fluoride into an aqueous solution of hydrofluosilicic acid having a specific gravity of at least 1,14, separating the gel formed and washing the gel with water, the washing being discontinued when the gel ceases to have a hydrofluosilic acid reaction.  The gel contains hydrofluoric acid in adsorptive combination and has disinfectant properties.  A high hydrofluoric acid content is obtained by using hydrofluosilicic acid of a high concentration and operating at a high temperature and vice versa.  Temperatures of 0-50 DEG  C., may be employed. During the reaction, water or steam may be added to keep the concentration of the hydrofluosilicic acid constant. Specification 267,907, [Class 1 (ii)], is referred to.  The Specification as open to inspection under Sect. 91 comprises also the production of a vehicle by reacting fluorine compounds with silicic acid or by associating colloidal silicic acid with fluorine compounds, e.g. complex fluohydroxy salts such as SiF4,2HF,H2O, SiF4,2HF.4H2O, CaF2.2HF.6H2O, TiO2F2.2HF, ZrOF2,H2O, ZrOF2,2HF,2H2O, HSi2O4F, SiO2F2,2HF, and Si(OH)2,F2(SiO2,2HF).  These vehicles yield hydrofluoric acid when in the presence of moisture.  In addition, the vehicles may be used in the preparation of powders, pastes or lotions for the treatment of the skin or body, or intestines or other internal organs, substances such as the following being added thereto, viz., salts of zinc, mercury, silver, gold, and copper, colloid metals or metalloids or compounds thereof such as sulphur or boric acid, diatomite earth, albumen preparations, milk albumen, milk albumen fat or partly decomposed, unstable milk albumen, &c.  This subject-matter does not appear in the Specification as accepted.