Zinc oxide photoactive material
AssigneeCape Cod Research, Inc.
InventorsRobert S. Morris, Myles A. Walsh, IV
Life of this patent
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Abstract
A non-toxic, antifouling coating composition is provided which comprises zinc oxide contacted with photosensitizer(s) which increase the capability of zinc oxide to absorb visible light.
Claims17
A material useful for producing antifouling activity when incorporated into a carrier comprising:
- about between 20 wt. % and 60 wt. % of the total material weight of zinc oxide containing less than about 0.001% by weight of lead, cadmium and sulphur oxides and being obtained from colloidal zinc oxide so as to have a mean particle size of between 0.1 to 0.5 microns and a surface area between 1 to 10 square meters per gram;
- a photosensitizer in photoelectric contact with zinc oxide and being present in a ratio of one part by weight or less of photosensitizer to four parts by weight zinc oxide, said photosensitizer having a solubility below five parts per million by weight in water and wherein said photosensitizer is contacted by said zinc oxide and is selected from the group consisting of fumed anatase, strontium titanate, bianthrone, azulene, zinc pyrithione, terthiophene, hypericin and mixtures thereof.
An antifouling paint composition comprising:
- paint, said paint containing zinc oxide in an amount of about between 20 wt. % and 60 wt. % of the total composition weight and having a mean particle size of about between 0.1 to 0.5 microns and a surface area of about between 1 to 10 square meters per gram and contacted with a photosensitizer selected from the group consisting of fumed anatase, strontium titanate, bianthrone, azulene, zinc pyrithione, terthiophene, hypericin and mixtures thereof.
A method of protecting a surface comprising coating said surface with an antifouling paint composition comprising about 40 to about 75 wt % paint, about 20 to about 60 wt % of the total composition weight of zinc oxide having a mean particle size of about between 0.1 and 0.5 microns and a surface area of about between 1 to 10 square meters per gram, and about 0.01 to about 5 wt % of the total composition weight of a photosensitizer which is contacted with said zinc oxide and is selected from the group consisting of fumed anatase, strontium titanate, bianthrone, azulene, zinc pyrithione, terthiophene and hypericin and mixtures thereof.
A method of preventing unwanted organic growth on a surface comprising:
- treating the surface with a composition containing 20-60 wt. % of the total composition weight of zinc oxide containing less than about 0.001% by weight of lead, cadmium and sulphur oxides and being obtained from colloidal zinc oxide so as to have a mean particle size of between 0.1 to 0.5 microns and a surface area between 1 to 10 square meters per gram;
- and
- about 5 wt. % of the total composition weight of a photosensitizer, wherein the photosensitizer is an inorganic pigment which is contacted with said zinc oxide and is selected from the group consisting of anatase, strontium titanate and mixtures thereof.
A method of preventing unwanted organic growth on a surface comprising:
- treating the surface with a composition containing 20-60 wt. % of the total composition weight of zinc oxide containing less than about 0.001% by weight of lead, cadmium and sulphur oxides and being obtained from colloidal zinc oxide so as to have a mean particle size of between 0.1 to 0.5 microns and a surface area between 1 to 10 square meters per gram;
- and about 5 wt. % of the total composition weight of a photosensitizer which contacts said zinc oxide, wherein the photosensitizer is an organic pigment selected from the group consisting of hypericin, azulene, and porphyrinatozinc and mixtures thereof.
Dependencies are inferred from the claim text.