SE310064

1,127,152. A silicone latex. DOW CORNING CORP. 12 Jan., 1966 [21 Jan., 1965; 7 Sept., 1965], No. 1489/66. Heading C3T. A silicone latex comprises an aqueous colloidal suspension of (1) a curable linear polysiloxane having at least 10 units per molecule, and (2) a silsesquioxane of unit formula R11Si...

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Main Author CEKADA J
Format Patent
LanguageEnglish
Published 14.04.1969
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Summary:1,127,152. A silicone latex. DOW CORNING CORP. 12 Jan., 1966 [21 Jan., 1965; 7 Sept., 1965], No. 1489/66. Heading C3T. A silicone latex comprises an aqueous colloidal suspension of (1) a curable linear polysiloxane having at least 10 units per molecule, and (2) a silsesquioxane of unit formula R11SiO 3/2 , where R11 is a methyl, ethyl, vinyl, phenyl or 3,3,3- trifluoropropyl radical, and having a particle size in the range of 10 to 1000 Š. Suitable polymers (1) are polysiloxanes or siloxane-silcarbane polymers having terminal Si-bonded OH or hydrocarbonoxy radicals, those which have been made by emulsion polymerization being preferred. The latex may also contain a cross-linking agent, e.g. a methylhydrogensiloxane or a silane of the formula wherein A is H or a monovalent hydrocarbon (h.c.) radical of 1-6 C atoms, with or without halogen substituents, m is 0 or 1, and R111 is H, an alkyl radical of 1-4 C atoms, -OCOCH 3 , -OCOC 2 H 5 , -CH 2 CH 2 OH, -CH 2 CH 2 OCH 3 or -CH 2 .CH 2 OC 2 H 5 , and a condensation catalyst which can be added as a solution, emulsion or undiluted liquid. Pigments, fillers, heat stabilizers and other additives may also be added. Usually 100 pts. (by wt.) of polymer (1), 1-100 pts. of polymer (2), 0À25 to 50 pts. of crosslinking agent and 0À25 to 5 pts. of catalyst are used for making the latices which preferably contain a total solids content of 5 to 20% by wt. The latices are made by first making a colloidal suspension of polymer (1), if not already in this form; the dispersing agent can be added per se or it can be the one used and present in the emulsion polymer or colloidal silsesquioxane, the silsesquioxane, cross-linker, catalyst and additives are then mixed with the suspension of polymer (1) to form the latex. The latices are stable on standing, but when applied to a substrate and the water evaporated, a film of silicone rubber or plastic is left behind, and curing by heat or irradiation will be necessary in some instances. Examples of the above latices are given. Uses.-For depositing insulating coatings on wires, coatings on medical devices, release coatings on papers, metals and moulds, coatings on fabrics, and protective and decorative coatings on wood, metal and concrete.
Bibliography:Application Number: SE19660000281