Thin film hydrophilic coatings

• US 5,688,855 A
• Filed: 05/01/1995
• Issued: 11/18/1997
• Est. Priority Date: 05/01/1995
• Status: Expired due to Fees

• Current Assignee: S.K.Y. Polymers Inc.
• Original Assignee: S.K.Y. Polymers Inc.
• Inventors: Stoy, Patrick, Stoy, Vladimir A., Gontarz, Gerald A. Jr.
• Primary Examiner(s): Szekely, Peter A.
• Application Number:
  US08/434,573
• Time in Patent Office: 932 Days
• Field of Search: 524/113, 524/360, 524/361, 524/323, 524/378, 524/379, 524/462, 524/464, 524/505
• US Class Current: 524/505
• CPC Class Codes: A61L 29/085 Macromolecular materials
• CPC Class Codes: A61L 29/145 Hydrogels or hydrocolloids
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: A61L 31/145 Hydrogels or hydrocolloids
• CPC Class Codes: C08G 18/4833 Polyethers containing oxyethylene units
• CPC Class Codes: C08G 18/6674 with compounds of group C08G18/3203
• CPC Class Codes: C08G 18/7825 containing ureum groups
• CPC Class Codes: C08G 18/8038 with compounds of C08G18/3225
• CPC Class Codes: C08G 2210/00 Compositions for preparing hydrogels
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C08L 51/08 grafted on to macromolecular compounds obtained otherwise than by reactions only involving unsaturated carbon-to-carbon bonds
• CPC Class Codes: C08L 75/04 Polyurethanes
• CPC Class Codes: C09D 121/02 Latex
• CPC Class Codes: C09D 175/04 Polyurethanes
• CPC Class Codes: C09D 5/00 Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced electrically insulating plastics, resins or waxes H01B3/30; Filling pastes

Abstract

A hydrophilic coating composition used to impart increased lubricity and wettability to the surface of a hydrophobic substrate which is comprised of three essential components:

1) Hydrogel-forming polymer component A

2) Water-soluble polymer component B

3) Common solvent C for the components A and B

The water-insoluble, hydrogel-forming component A consists of a segmented copolymer with long, hydrophilic terminal blocks and the essentially hydrophobic central section. The two polymer components A and B have a limited miscibility in the absence of a common solvent C. Therefore, their blend tends to separate spontaneously into two polymer phases. The phase separation takes place during the solvent evaporation or extraction. A gradient of hydrophilicity and swelling within the coating layer is thus spontaneously created achieving a good adhesion to the substrate and high surface hydrophilicity at the same time.

Claims

1. A hydrophilic coating composition for hydrophobic substrates, comprising:

A mixture of a hydrogel-forming polymeric component A and a polymeric water-soluble component B in a common solvent C, wherein the said polymer component A is capable of forming a hydrogel containing 50% to 99% water in equilibrium, and wherein the said component A is a segmented copolymer of a general formula

space="preserve" listing-type="equation">T.sub.1 --X--T.sub.2

wherein T₁, T₂ are terminal hydrophilic segments and the central section X comprises at least one hydrophobic polymer sequence.

2. A hydrophilic coating composition for hydrophobic substrate according to claim 1 wherein at least one of the said terminal sequence T₁ and/or T₂ is a hydrophilic sequence comprising at least 25 hydrophilic monomer units selected from the group consisting of acrylic acid, methacrylic acid, hydrophilic esters of acrylic or methacrylic acid, hydrophilic amides of acrylic or methacrylic acids, alkylene oxide, ethylene oxide, maleic acid, styrenesulfonic acid, vinylsulfonic acid, vinylpyrrolidone, methylvinylether and saccharide units.

3. A hydrophilic coating composition for hydrophobic substrates according to claim 1 wherein the said central section X of the component A is a water-insoluble polymer chain described by the formula

4. A hydrophilic coating composition for hydrophobic substrates according to claim 1 wherein the said polymeric components A and B are present in a weight ratio between 9:

1 and 1;

3.

5. A hydrophilic coating composition for hydrophobic substrates according to claim 3 wherein the said hydrophobic blocks HB are polymers and copolymers selected from the group consisting of polymers of esters, N-alkylacrylamides, nitriles of acrylic acid, nitriles of methacrylic acid, styrene, methyl styrene, vinyl acetate, vinyl formal, and vinylbutyral, and polyamides, polyesters, polyepoxides, aliphatic polyurethanes, cycloaliphatic polyurethanes, aromatic polyurethanes, aliphatic polyureas, cycloaliphatic polyureas and aromatic polyureas.

6. A hydrophilic coating composition for hydrophobic substrates according to claim 1 wherein the number average of molecular weight of the individual block HB is between about 250 and about 50,000 Daltons.

7. A hydrophilic coating composition for hydrophobic substrates according to claim 3 wherein the linking sequences L are either hydrophobic or hydrophilic chemical moieties having a number average of molecular weight lower than 25,000 Daltons.

8. A hydrophilic coating composition for hydrophobic substrates according to claim 3 wherein the said linking sequences L are chemical moieties having radicals selected from the group consisting of ester, ether, amide, urethane, urea, imide and imine radicals.

9. A hydrophilic coating composition for hydrophobic substrates according to claim 5 wherein the said hydrophobic segments HB are of the general formula

10. A hydrophilic coating composition for hydrophobic substrates according to claim 9 wherein at least one of the said substituents R₁, R₂ and R₄ are of the formula ##STR6##

11. A hydrophilic coating composition for hydrophobic substrates according to claim 1 wherein said component B comprises a water-soluble polymer having polar radicals selected from the group consisting of hydroxyl, ether, carboxyl, amine, imine, amide, lactam, lactone, amidine, quaternary ammonium salt, sulfonic acid and sulphate radicals.

12. A hydrophilic coating composition for hydrophobic substrates according to claim 1 wherein the said water-soluble component B comprises a polymer selected from the group consisting of polyalkylene oxide, poly(vinylpyrrolidone), poly(vinyl methyl ether), poly(N-alkylacrylamides), poly(methacrylamide), poly(acrylic acid), poly(methacrylic acid), poly(ethyleneglycol), copolymers of poly(ethyleneoxide-propyleneoxide), poly(ethyleneoxide), copolymers of maleic acid, poly(vinylalcohol), poly(ethyleneimine), carboxymethylcellulose, polyvinylsulfonic acid, polystyrene sulfonic acid, hyaluronic acid, heparin, dextran, dextran sulphate and chondroitin sulphate.

13. A hydrophilic coating composition for hydrophobic substrates according to claim 1 wherein the said water-soluble component B comprises a water-soluble polymer composed from 100 to 20,000 monomer units.

14. A hydrophilic coating composition for hydrophobic substrates according to claim 1 wherein the said common solvent component C comprises a liquid selected from the group consisting of tetrahydrofuran, dioxane, dialkylether, acetone, methylethylketone, lower halogenated hydrocarbons C1-C6, lower aliphatic alcohols C1-C6, benzene, toluene, xylene, cyclohexanone, acetonitrile, alkylacetate, tetramethylene sulfone, dimethylsulfoxide, g-butyrolactone, phenols, formic acid and acetic acid.

15. A hydrophilic coating composition for hydrophobic substrates according to claim 1 wherein the said common solvent comprises between 0.25% and 15% of water.

16. A hydrophilic coating composition for hydrophobic substrates according to claim 1 wherein the said common solvent component C is an aqueous solution of a substance selected from the group consisting of sodium thiocyanate, potassium thiocyanate, calcium thiocyanate, zinc chloride, lithium bromide, magnesium perchlorate, phosphoric acid, nitric acid and sulfuric acid.

17. A hydrophilic coating composition for hydrophobic substrates according to claim 1 wherein the said common solvent component C constitutes more than 95% by weight.

18. A hydrophilic coating composition for hydrophobic substrates according to claim 1 comprising in addition to the components A, B and C also another component selected from the group consisting of a surfactant, a pigment, a dyestuff, an antibiotic, a disinfectant, a bactericide, a biocide, a UV absorber, a coagulant and a biologically active peptide or protein.