Method of making thrombo-resistant non-thrombogenic objects formed from a uniform mixture of a particulate resin and colloidal graphite

Claim 2

In a method of preparing thrombo-resistant non-thrombogenic objects, the steps of; preparing a uniform mixture of resin in particulate form and colloidal graphite; processing said mixture into an object of predetermined size and configuration and having exposed surfaces; etching the exposed surfaces of said object to expose surface areas of the colloidal graphite particles at or immediately underlying the exposed surfaces of said object; cleaning the etched object; coating the cleaned object with a cationic surface active agent; and applying a coating of Heparin over the cationic surface active agent coating.

Claim 3

The method of claim 1 in which said mixture comprises a major portion of said resin and a minor portion of said colloidal graphite.

Claim 4

The method of claim 1 in which said mixture comprises from about 99% to about 70% resin and from about 1% to about 30% colloidal graphite; and in which said resin is selected from the group consisting of halogonated bydrocarbons, polyolefins, polyurethanes, silicones and vinyls.

Claim 5

The method of claim 3 in which said resin is a fluoropolymer.

Claim 6

The method of claim 3 in which said resin is polyethylene.

Claim 7

The method of claim 3 in which said resin is polypropylene.

Claim 8

The method of claim 3 in which said resin is polyvinylchloride.

Claim 9

The method of claim 3 in which said etching is effected by a dispersion of metallic sodium when said resin is a halogenated hydrocarbon.

Claim 10

The method of claim 3 in which said etching is effected by a hot oxidizing acid selected from the group consisting of a combination of sulfuric and chromic acids and a combination of sulfuric acid and sodium dichromate.

Claim 11

In a method of preparing Heparin-receptive surfaces on objects intended for retention in the vascular systems of animate beings, the steps of; preparing a uniform mixture of resin in particulate form and colloidal graphite; processing said mixture into an object of predetermined size and configuration and having exposed surfaces; etching the exposed surfaces of said object to expose surface areas of the colloidal graphite particles at or immediately underlying the exposed surfaces of said object; cleaning the etched object; and coating the cleaned object with a cationic surface active agent.

Claim 12

In a method of preparing Heparin-receptive surfaces on objects intended for retention in the vascular systems of animate beings, the steps of; preparing a uniform mixture of resin in particulate form and colloidal graphite; processing said mixture into an object of predetermined size and configuration and having exposed surfaces; etching the exposed surfaces of said object to expose surface areas of the colloidal graphite particles at or immediately underlying the exposed surfaces of said object; cleaning the etched object; and coating the cleaned object with a cationic surface active agent.

Claim 13

The method of claim 3 in which said resin is silicone.

Claim 14

In a method of forming a flexible tubular object having thrombo-resistant non-thromboginic exterior surfaces the steps of; providing a flexible tubular inner body of predetermined length: preparing an outer flexible tubular sheath having a length at least coextensive with said inner body and formed from a uniform mixture of colloidal graphite and a particulate resin selected from the group comprising halogenated hydrocarbons, polyolefins and polyvinyls; fitting said outer sheath over said inner body; heat shrinking said outer sheath into firmly bonded contact with said inner body; etching the exterior surfaces of said outer sheath to expose a multitude of particles of said colloidal graphite; coating the etched surfaces of said outer sheath with a cationic surface active agent; and applying a coating of heparin over said cationic surface active agent coating.

Claim 15

In a method of forming a flexible tubular object having thrombo-resistant non-thromboginic exterior surfaces the steps of; providing a flexible tubular inner body of predetermined length: preparing an outer flexible tubular sheath having a length at least coextensive with said inner body and formed from a uniform mixture of colloidal graphite and a particulate resin selected from the group comprising halogenated hydrocarbons, polyolefins and polyvinyls; fitting said outer sheath over said inner body; heat shrinking said outer sheath into firmly bonded contact with said inner body; etching the exterior surfaces of said outer sheath to expose a multitude of particles of said colloidal graphite; coating the etched surfaces of said outer sheath with a cationic surface active agent; and applying a coating of heparin over said cationic surface active agent coating.