Antimicrobial compositions, process for preparing the same and use
AssigneeE. I. Du Pont de Nemours and Company
InventorsHoward W. Jacobson, Michael H. Scholla, Sam L. Samuels
Life of this patent
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Abstract
An antimicrobial composition comprising an inorganic particle with a first coating providing antimicrobial properties and a second coating providing a protective function, method for preparing the same and uses; further processes for producing polymeric articles and a method for controlling microorganisms.
Claims20
An antimicrobial composition comprising tens of microns to submicron inorganic core particles selected form the group consisting of the oxides of titanium, aluminum, zinc and copper, sulfates of calcium, strontium and barium, zinc sulfide, copper sulfide, zeolites, mica, talc, kaolin, mullite and silica, said core particles having a primary surface coating, comprising 0.05 to 20% by weight based on the core particles, of a metal or metal compound having antimicrobial properties selected from the group consisting of silver, silver oxide, silver halides, copper, copper (I) oxide, copper (II) oxide, copper sulfide, zinc oxide, zinc sulfide, zinc silicate and mixtures thereof, which are coated with a secondary protective layer comprising 0.5 to 20% by weight and is selected from the group consisting of silica, silicates, borosilicates, aluminosilicates, alumina, aluminum phosphate and mixtures thereof.
An antimicrobial composition comprising tens of micron to submicron inorganic core particles selected form the group consisting of titanium dioxide and barium sulfate;
- said core particles having a coating comprising a primary layer of about 0.1 to 5.0% by weight based on the core particles and is selected from the group consisting of mixtures of silver with zinc silicate and silver with copper (II) oxide, and further comprising, a secondary protective layer selected form the group consisting of silica, silicates, borosilicates, aluminosilicates, alumina, aluminum phosphate or mixtures thereof, wherein the secondary layer comprises 0.5 to 20% by weight based on the core particles.
A process for preparing antimicrobial powder compositions comprising the steps of:
- (a) forming an aqueous suspension of inorganic core particles selected from the group consisting of oxides of Ti, Al, Zn and Cu, the sulfates of Ca, Sr and Ba, zinc sulfide, copper sulfide, zeolite, mica, talc, kaolin and silica;
- (b) precipitating a layer of an antimicrobial coating on said core particles, wherein said precipitated antimicrobial coating results in 0.05 to 20% by weight based on the core particles and said precipitated antimicrobial coating is selected from the group consisting of Ag, Ag.sub.2 O, AgCl, AgBr, AgI, Cu, CuO, Cu.sub.2 O, CuS, ZnO, ZnS, ZnSiO.sub.3 and their combinations;
- (c) adding an alkali metal silicate or aluminate and maintaining the pH between 5 to 9, to deposit a secondary coating in amounts of 0.5 to 20% by weight based on the core particles, wherein said secondary coating is selected form the group consisting of silica, silicates, borosilicates, aluminosilicates, alumina, aluminum phosphate and mixtures thereof;
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- (d) recovering the powder and removing soluble salts.
Dependencies are inferred from the claim text.