Copolymers and non-porous, semi-permeable membrane thereof and its use for permeating molecules of predetermined molecular weight range
Patent 5428123 Issued on June 27, 1995. Estimated Expiration Date: 
April 23, 2013. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
April 23, 2013. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3804786 3826768 3852090 Thermoplastic polyurethane elastomer Aqueous polyurethane dispersions Water-dispersible polyurethanes Delivery means for biologically active agents comprising hydrophilic polyurethane Thermoplastic polyurethane elastomers from polyoxypropylene polyoxyethylene block copolymers Polyurethanes prepared with tetrahydrofuran-alkylene oxide polymerizates having low oligomeric cyclic ether content Breathable, non-porous polyurethane film prepared from a low molecular weight difunctional compound, a polyethylene glycol and a diisocyanate InventorsAssigneeApplicationNo. 052361 filed on 04/23/1993US Classes:528/28, Organic Si-free reactant is a nitrogen-containing compound210/500.21, Semipermeable membrane210/500.23, Hollow fiber or cylinder525/453, Solid polymer derived from -N=C=X reactant and polyhydroxy reactant525/459, Solid polymer derived from -N=C=X reactant and polyhydroxy reactant also derived from polyamine reactant525/460, Solid polymer derived from -N=C=X reactant and polyhydroxy reactant derived from polyhydroxy reactant containing an ether group528/10, FROM SILICON REACTANT HAVING AT LEAST ONE SILICON-TO-HYDROGEN OR -CARBON BOND528/25, With organic silicon-free reactant528/34With silicon reactant containing a single silicon atomExaminersPrimary: Michl, Paul R.Assistant: Truong, Duc Attorney, Agent or FirmForeign Patent References
International ClassC08G 077/04AbstractA biocompatible, hydrophilic, segmented block polyurethane copolymer which comprises 5 to 45 wt % of a hard segment and 95 to 55 wt % of a soft segment selected from a hydrophilic, hydrophobic and amphipathic oligomer is disclosed. The copolymer is capable of forming a non-porous, semi-permeable film of a tensile strength greater than 300 and up to 10,000 psi, and has an ultimate elongation greater than 300% and up to 1,500% and a water absorption such that the sum of the volume fraction of absorbed water and the hydrophilic volume fraction of the soft segment exceeds about 100% and is up to about 2,000% of the dry polymer volume. The film is permeable to cell nutrients and waste molecules of up to about 6,000 to 600,000 molecular weight and is substantially impermeable to cells and particulate matter. A non-porous, semi-permeable, biocompatible film is formed from the block copolymer of the invention in the form of a flexible sheet or a hollow fiber. Also disclosed is a method of permeating molecules of a predetermined molecular weight range while preventing the passage of larger molecular weight molecules, cells, and condensed phases of matter between two fluids comprising interposing between the two fluids the non-porous film of the invention.Other References
Field of SearchSolid polymer derived from -N=C=X reactant and polyhydroxy reactantSolid polymer derived from -N=C=X reactant and polyhydroxy reactant also derived from polyamine reactant Solid polymer derived from -N=C=X reactant and polyhydroxy reactant derived from polyhydroxy reactant containing an ether group Semipermeable membrane Hollow fiber or cylinder | |
