Coatings appropriate for medical devices
AssigneeBiocoat Incorporated
InventorsEllington M. Beavers, William James Work
Life of this patent
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Abstract
Biocompatible, lubricious, highly durable coatings for medical devices are formed from a highly adherent base coat and a hydrophilic top-coat which is chemically grafted to the base coat. The base coat includes an aqueous acrylic emulsion polymer, having one or more monomers having alkyl groups of varying number. The monomers are combined such that the “Equivalent Alkyl Number”, essentially a weighted average number of carbon atoms, for the resulting polymer or copolymer, is in a range of about 3.5-4.5. The coating is prepared without using any organic solvents, and thus the final product contains no residue of such solvents. The coated products display an unmatched combination of adhesion, abrasion resistance, water resistance, biocompatibility, and lubricity.
Claims41
In a system comprising a substrate having a bilaminar coating, the bilaminar coating comprising a base coat which is firmly adhered to the substrate, and a top-coat, the top-coat being chemically grafted to the base coat, the top-coat being hydrophilic, lubricious, and biocompatible,
- the improvement wherein the base coat comprises an aqueous acrylic emulsion polymer, the polymer comprising at least one monomer having an alkyl group, wherein the polymer has an Equivalent Alkyl Number in a range of about 3.5 to about 4.5, the Equivalent Alkyl Number being defined by EAN = n 1 N 1 + n 2 N 2 + … + n m N m N 1 + N 2 + … + N m
- where ni is a number of carbon atoms in an alkyl group of monomer i, and Ni is a number of moles of monomer i in the polymer, and where m is a positive integer,
- the base coat also comprising functional groups capable of grafting the emulsion polymer to the top-coat.
In a system comprising a substrate having a bilaminar coating, the bilaminar coating comprising a base coat which is firmly adhered to the substrate, and a top-coat, the top-coat being chemically grafted to the base coat, the top-coat being hydrophilic, lubricious, and biocompatible,
- the improvement wherein the base coat comprises an aqueous acrylic emulsion polymer, the polymer comprising at least one monomer having an alkyl group, wherein the polymer has an Equivalent Alkyl Number in a range of about 3.5 to about 4.5, the Equivalent Alkyl Number being defined by EAN = n 1 N 1 + n 2 N 2 + … + n m N m N 1 + N 2 + … + N m
- where ni is a number of carbon atoms in an alkyl group of monomer i, and Ni is a number of moles of monomer i in the polymer, and where m is a positive integer,
- the base coat also comprising functional groups capable of grafting the emulsion polymer to the top-coat,
- wherein the emulsion polymer is free of any organic solvents,
- wherein said functional groups comprise at least one acidic monomer, in an amount of about 3-11 mole percent of the total monomer composition of the emulsion polymer, wherein said acidic monomer is selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, acryloxypropionic acid, and any acidic monomer capable of copolymerization with said at least one monomer of said acrylic emulsion polymer.
A substrate having a bilaminar coating, the bilaminar coating including a base coat which is firmly adhered to the substrate, and a top-coat which is chemically grafted to the base coat,
- the base coat comprising an aqueous acrylic emulsion polymer, the polymer comprising at least one monomer having an alkyl group, wherein the polymer has an Equivalent Alkyl Number in a range of about 3.5 to about 4.5, the Equivalent Alkyl Number being defined by EAN = n 1 N 1 + n 2 N 2 + … + n m N m N 1 + N 2 + … + N m
- where ni is a number of carbon atoms in an alkyl group of monomer i, and Ni is a number of moles of monomer i in the polymer, and where m is a positive integer,
- the top-coat comprising functional groups capable of grafting the top-coat to the base coat.
A method of applying a biocompatible coating to a substrate, comprising:
- a) assembling an emulsion polymer from at least one acrylic monomer, the acrylic monomer having an alkyl group, such that the emulsion polymer has an Equivalent Alkyl Number (EAN) in a range of about 3.5 to about 4.5, where EAN = n 1 N 1 + n 2 N 2 + … + n m N m N 1 + N 2 + … + N m
- where ni is a number of carbon atoms in an alkyl group of monomer i, and Ni is a number of moles of monomer i in the polymer, and where m is a positive integer,
- b) coating the substrate with the emulsion polymer made in step (a), to form a base coat, and
- c) applying a hydrophilic top-coat to the coated substrate, and causing the top-coat to become grafted to the coated substrate,
- wherein steps (a) through (c) are performed without using any organic solvents.
Dependencies are inferred from the claim text.