Multi-layered tubing

Abstract

Tubing comprising an inner layer, an outer layer and a middle layer, wherein the inner layer comprises a polyethylene, the outer layer comprises a thermoplastic polyurethane and the middle layer comprises an ethylene ethyl acrylate copolymer or an ethylene methyl acrylate copolymer or an anhydride grafted ethylene methyl acrylate copolymer, a copolymer of two or more of the acrylate copolymers or a mixture of two or more thereof.

1 . A tube comprising an inner layer, an outer layer and a middle layer, wherein the inner layer comprises a polyethylene, the outer layer comprises a thermoplastic polyurethane and the middle layer comprises an ethylene ethyl acrylate copolymer or an ethylene methyl acrylate copolymer or an anhydride grafted ethylene methyl acrylate copolymer, a copolymer of two or more of said acrylates or a mixture of two or more of the foregoing. 
     
     
         2 . The tube of  claim 1  where the inner layer comprises more than about 90% by weight of a polyethylene, the outer layer comprises more than about 90% by weight of an aromatic or aliphatic polyether based polyurethane and the middle layer comprises more than about 90% by weight of an ethylene ethyl acrylate copolymer. 
     
     
         3 . The tube of  claim 2  where the polyethylene comprises one or more of a low density polyethylene, a linear low density polyethylene and a high density polyethylene, the aromatic polyether based polyurethane comprises a polytetramethyleneglycol-based polyurethane and the ethylene ethyl acrylate copolymer comprises at least about 19.5 percent ethyl acrylate content by weight. 
     
     
         4 . The tube of  claim 1  wherein the inner layer comprises more than about 90% by weight of polyethylene, the outer layer comprises more than about 90% by weight of a aromatic polyether based polyurethane and the middle layer comprises more than about 90% by weight of an ethylene methyl acrylate copolymer. 
     
     
         5 . The tube of  claim 4  where the polyethylene comprises one or more of a low density polyethylene, a linear low density polyethylene and a high density polyethylene, the aromatic polyether based polyurethane comprises a polytetramethyleneglycol-based polyurethane and the ethylene methyl acrylate copolymer comprises at least about 19.5 percent by weight methyl acrylate content. 
     
     
         6 . The tube of  claim 1  where the inner layer comprises more than about 90% by weight of low density polyethylene (LDPE), the outer layer comprises more than about 90% by weight of a polytetramethyleneglycol-based polyurethane and the middle layer comprises more than about 90% an anhydride grafted ethylene methyl acrylate copolymer. 
     
     
         7 . The tube of  claim 1  wherein the thickness of the polyurethane outer layer is between about 0.001″ and about 0.025″, the thickness of the inner polyethylene layer is between about 0.001″ and about 0.025″ and the thickness of the intermediate acrylate copolymer layer is between about 0.001″ and about 0.025″. 
     
     
         8 . The tube of  claim 1  wherein the inner and outer layers do not visually delaminate from each other at a stress up to of about 55 MPa and a strain up to about 900-950%. 
     
     
         9 . The tube of  claim 1  wherein the tube does not visually delaminate when submersed in water at 60° C. for 36 hours. 
     
     
         10 . The tube of  claim 1  wherein the tube has a central axial fluid flow passage through which aqueous fluid is routed, the inner layer having a radially inner wall surface that contacts the aqueous fluid the outer and inner layers resisting delamination from each other at a stress of up to about 55 MPa and a strain of up to about 900-950%. 
     
     
         11 . The tube of  claim 10  wherein the tube does not visually delaminate after being submersed in water at 60° C. for 36 hours. 
     
     
         12 . A medical tube for transport of aqueous fluid comprising:
 an inner layer comprising more than about 90% by weight of a polyethylene   an outer layer comprising more than about 90% by weight of an aromatic polyether-based polyurethane and,   a middle layer disposed between the outer and inner layers comprising more than about 90% by weight of an ethylene ethyl acrylate copolymer or an ethylene methyl acrylate copolymer or an anhydride grafted ethylene methyl acrylate copolymer, a copolymer of two or more of said acrylates or a mixture of two or more of the foregoing.   
     
     
         13 . The medical tube of  claim 12  wherein the inner and outer layers do not visually delaminate from each other at a stress of up to about 55 MPa and a strain of up to about 900-950%. 
     
     
         14 . The tube of  claim 13  wherein the tube does not visually delaminate after being submersed in water at 60° C. for 36 hours. 
     
     
         15 . A medical tube for transport of an aqueous fluid comprising:
 an inner layer comprised of at least about 90% by weight of a polyethylene.   an outer layer comprised of at least about 90% by weight of an aromatic polyether-based polyurethane,   a middle layer disposed between the inner and outer layers comprised of at least about 90% by weight of an ethylene ethyl acrylate copolymer, an ethylene methyl acrylate copolymer, an anhydride grafted ethylene methyl acrylate copolymer, a copolymer of two or more of said acrylates or a mixture of two or more of the foregoing,   wherein said tubing does not visually delaminate after being submersed in water at 60° C. for 36 hours.   
     
     
         16 . A medical tube for transport of an aqueous fluid comprising:
 an inner layer comprised of at least about 90% by weight of a low density polyethylene,   an outer layer comprised of at least about 90% by weight of a polytetramethyleneglycol-based polyurethane,   a middle layer comprised of at least about 90% by weight of an ethylene ethyl acrylate copolymer, an ethylene methyl acrylate copolymer, an anhydride grafted ethylene methyl acrylate copolymer, a copolymer of said acrylates or a mixture of two or more of the foregoing,   wherein the tubing does not visually delaminate at a stress of up to about 55 MPa and a strain of up to about 900-950%, and,   wherein the tubing does not visually delaminate after being submersed in water at 60° C. for 36 hours.   
     
     
         17 . Method of forming a medical tube comprising an outer layer, an innermost layer and an intermediate layer disposed between the outer layer and the innermost layer, the method comprising:
 selecting a first polymeric material having a selected structural stability;   selecting a second polymeric material that is inert to aqueous fluids;   selecting a third polymeric material that readily bonds and adheres to the first and second polymeric materials on co-extrusion and cooling of the materials;   co-extruding the selected first, second and third polymeric materials to form the medical tubing in a configuration such that the outer layer comprises at least about 90% by weight of the first polymeric material, the inner layer comprises at least about 90% weight of the second polymeric material and the intermediate layer comprises at least about 90% by weight of the third polymeric material.   
     
     
         18 . The method of  claim 17  wherein the first polymeric material is selected to be a polyurethane, the second polymeric material is selected to be a polyethylene and the third polymeric material is selected from the group consisting of an ethylene ethyl acrylate copolymer, an ethylene methyl acrylate copolymer, an anhydride grafted ethylene methyl acrylate copolymer, a copolymer of said acrylates or a mixture of two or more of the foregoing. 
     
     
         19 . Method of delivering an aqueous fluid to a subject comprising;
 selecting a tube comprising an inner layer, an outer layer and a middle layer, wherein the inner layer comprises a polyethylene, the outer layer comprises a thermoplastic polyurethane and the middle layer comprises an ethylene ethyl acrylate copolymer or an ethylene methyl acrylate copolymer or an anhydride grafted ethylene methyl acrylate copolymer, a copolymer of two or more of said acrylates or a mixture of two or more of the foregoing;   wherein the tube has a central fluid flow passage surrounded by the layers;   routing an aqueous fluid through the central fluid flow passage of the tube, and,   delivering the aqueous fluid routed through the central fluid flow passage into a blood vessel of the subject.   
     
     
         20 . The method of  claim 19  wherein the step of selecting comprises:
 Co-extruding the outer, inner and middle layers to form the tube such that the outer layer comprises at least about 90% by weight of the polyurethane, the inner layer comprises at least about 90% weight of the polyethylyene and the intermediate layer comprises at least about 90% by weight of one or more of the arcylate copolymers.