Single-dip process for achieving a layer-by-layer-like coating
AssigneeNovartis AG
InventorsLynn Cook Winterton, John Martin Lally, Michael Rubner, Yongxing Qiu
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Abstract
A method of forming a coating of polyionic materials in a layer-by-layer-like manner onto a polymeric material is provided. A polymeric material, such as a contact lens, can be dipped once into a solution of polyionic materials such that layers of polyionic material can be formed thereon. A single dip solution of the present invention typically contains a polyanionic material and a polycationic material in a non-stoichiometric amount and maintained within a certain pH range.
Claims25
A method of coating a polymeric substrate comprising the steps of:
- forming a solution, said solution containing a polyanionic material having a plurality of negatively charged groups along a polymer chain and a polycationic material having a plurality of positively charged groups along a polymer chain in an amount such that the molar charge ratio of said solution is from about 3:1 to about 100:1;
- maintaining the pH of said solution within a range so that said polyanionic material and said polycationic material remain stable within said solution;
- and
- applying said solution to said substrate to form a coating thereon, said coating on said substrate having at least two layers so that one of said layers comprises said polyanionic material and another of said layers comprises said polycationic material.
A method of coating a polymeric material comprising the steps of:
- forming a polyionic solution, said polyionic solution containing a polyanionic material and a polycationic material in an amount such that the molar charge ratio of said solution is less than about 10:1;
- maintaining the pH of said solution within a range so that said polyanionic and polycationic materials remain stable within said polyionic solution;
- providing a substrate;
- applying a solvent to said substrate, said solvent being capable of forming a stable solution when combined with said solution containing said palyanionic and said polycationic materials;
- allowing said substrate to swell in said solvent;
- removing said substrate from said solvent after swelling said substrate therein;
- and
- dipping said substrate into said solution to form a coating thereon, said coated substrate having at least two layers with one of said layers comprising said polyanionic material and another of said layers comprising said polycationic material.
Dependencies are inferred from the claim text.