Water-borne antimicrobial formulations with hydrogen peroxide
Inventors
Toreki, William • Kanga, Rustom S.
Assignees
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Publication Number
US-9999226-B2
Publication Date
2018-06-19
Expiration Date
Abstract
This invention relates to regenerable antimicrobial coatings with long-lasting efficacy for use in medical applications including implants, medical instruments or devices, and hospital equipment. The same coatings would also have broad utility in the consumer, industrial, and institutional markets. The coating technology would be based on sequestration of hydrogen peroxide (HP) by zinc oxide binders incorporated into the coatings.
Core Innovation
The disclosure relates to regenerable antimicrobial coatings and water-borne formulations that provide durable antimicrobial activity to a substrate. The formulations use an aqueous dispersion comprising a metal derivative and a polymer with defined water absorbency, together with hydrogen peroxide.
The metal derivative is selected from a hydroxide, an oxide, or a peroxide of a metal selected from zinc, magnesium, titanium, and zirconium. The polymer is doped with 1% to 50% (w/w) of the metal derivative and has water absorbency between 0.5% and 20% (w/w).
The antimicrobial activity is enabled by sequestered hydrogen peroxide associated with the polymer doped with the metal derivative. When the polymer is exposed to an aqueous hydrogen peroxide source, the antimicrobial activity of the doped polymer can be regenerated on subsequent exposure to aqueous hydrogen peroxide.
In coating form, the regenerable antimicrobial water-borne coating provides antimicrobial performance after preparation and enhanced performance relative to a corresponding coating that has not been exposed to hydrogen peroxide. The coating is tested using ASTM Standard Method E2180 at least 24 hours after preparation and provides at least a 3-log reduction of viable Escherichia coli greater than that of a corresponding coating that has not been exposed to hydrogen peroxide.
Claims Coverage
The independent claims cover three main inventive concepts: a water-borne antimicrobial formulation for imparting durable antimicrobial activity, a method of enhancing and regenerating durable antimicrobial activity using the formulation and drying, and a regenerable antimicrobial water-borne coating that contains sequestered hydrogen peroxide and regenerates antimicrobial activity upon subsequent exposure to aqueous hydrogen peroxide. Across these, the inventive features are the defined aqueous dispersion/composition, the polymer water absorbency and doping/loading constraints, and the regeneration/relative antimicrobial test outcome recited for the coating.
A water-borne formulation with metal derivative, polymer water absorbency, and hydrogen peroxide
A water-borne formulation for imparting durable antimicrobial activity to a substrate, wherein said water-borne formulation is an aqueous dispersion comprising: a metal derivative selected from a hydroxide, an oxide, or a peroxide of a metal selected from zinc, magnesium, titanium, and zirconium; a polymer with water absorbency between 0.5% and 20% (w/w); and hydrogen peroxide, wherein the metal derivative comprises up to 10% (w/w) of the formulation, wherein the polymer comprises up to 36% (w/w) of the formulation, and wherein the hydrogen peroxide concentration is between 0.5% and 10% (w/w).
Enhancing and regenerating durable antimicrobial activity by applying a water-borne formulation and drying
A method of enhancing and regenerating durable antimicrobial activity of the surface of a substrate, wherein said method comprises: providing, on the surface of a substrate, a water-borne formulation comprising an aqueous dispersion of a metal derivative (hydroxide/oxide/peroxide of zinc, magnesium, titanium, and zirconium), a polymer with water absorbency between 0.5% and 20% (w/w), and hydrogen peroxide; and drying said substrate, wherein the metal derivative comprises up to 10% of the aqueous dispersion, the polymer comprises up to 36% of the aqueous dispersion, and the aqueous hydrogen peroxide has a concentration between 0.5% and 10%.
A regenerable antimicrobial water-borne coating with doped polymer and sequestered hydrogen peroxide
A regenerable antimicrobial water-borne coating on a substrate comprising: a metal derivative selected from a hydroxide, an oxide, or a peroxide of a metal selected from zinc, magnesium, titanium, and zirconium; a polymer doped with 1% to 50% (w/w) of said metal derivative; sequestered hydrogen peroxide; and wherein the water absorbency of said polymer is between 0.5% and 20% (w/w), wherein said polymer doped with said metal derivative has been determined to be capable of sequestering hydrogen peroxide when exposed to said source of aqueous hydrogen peroxide, and wherein the antimicrobial activity of said doped polymer can be regenerated on subsequent exposure to aqueous hydrogen peroxide, whereby said antimicrobial coating, when tested using ASTM Standard Method E2180 at least 24 hours after preparation, provides at least a 3-log reduction of viable Escherichia coli greater than that of a corresponding coating which has not been exposed to hydrogen peroxide.
Overall, the claim coverage centers on aqueous water-borne systems that combine a specified metal derivative class, a polymer having specified water absorbency (and in the coating, doped with 1% to 50% of the metal derivative), and hydrogen peroxide or sequestered hydrogen peroxide, with regeneration of antimicrobial activity upon subsequent exposure to aqueous hydrogen peroxide. The coating claim additionally ties the composition and regeneration concept to an ASTM E2180 relative antimicrobial reduction outcome against viable Escherichia coli.
Stated Advantages
Provides durable antimicrobial activity imparted to a substrate via the recited water-borne formulation and/or coating.
Antimicrobial activity can be regenerated on subsequent exposure to aqueous hydrogen peroxide.
When tested using ASTM Standard Method E2180 at least 24 hours after preparation, provides at least a 3-log reduction of viable Escherichia coli greater than a corresponding coating that has not been exposed to hydrogen peroxide.
Documented Applications
Enhancing and regenerating durable antimicrobial activity of a substrate surface by applying the water-borne formulation and drying.
Providing a regenerable antimicrobial water-borne coating on a substrate, including application to a textile article made from cotton, rayon, polyester, nylon, or acrylic.
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