# US 11,999,837 B2 · Modified porous polyolefin film and method of making > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,999,837 B2 - Document ID: US11999837B2 - Status: Granted - Kind: B2 - Application number: 17/045,061 - Filed: 2019-04-08 - Published: 2021-06-03 - Granted: 2024-06-04 - Earliest claimed: 2018-04-13 - Assignees: Dsm IP Assets B.V. - Applicants: DSM IP Assets B.V. - Inventors: Nicolaes Hubertus Maria De Bont; Mandy Maria Jozefina Wiermans; Marc Linssen - Web page: https://patentgrep.com/patent/US11999837B2 ## CPC - C08J 9/42: with macromolecular compounds - C08J 5/18: Manufacture of films or sheets - C08L 23/06: Polyethylene - C08L 75/08: from polyethers - C08J 2207/10: Medical applications, e.g. biocompatible scaffolds - C08J 2323/06: Polyethene - C08J 2475/04: Polyurethanes - C08J 2475/08: from polyethers - C08L 2203/02: for biomedical use - C08L 2207/04: Thermoplastic elastomer - C08L 2207/068: Ultra high molecular weight polyethylene - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) ## Abstract Disclosed herein is a porous hybrid elastomer/polyolefin film, which is a porous polyolefin film wherein at one or more isolated areas of the film pores are at least partly filled with an elastomer. This hybrid film shows improved resistance to tearing, whereas other properties like porosity, polarity, thickness, flexibility, and non-stickiness of the film are substantially retained. Other advantages include improved suture retention. The invention also provides a method to increase tear resistance of a porous polyolefin film comprising steps of providing a porous polyolefin film; identifying one or more locations on the film, at which locations tearing is likely to occur during intended use of the film; applying at the identified locations of the film an amount of a solution of an elastomer in solvent; and substantially removing the solvent; to result in a hybrid elastomer/polyolefin film having one or more isolated areas where pores in the film are at least partly filled with the elastomer. Further aspects concern uses of these hybrid films as a component of a medical implant or device, especially for use in contact with body tissue or fluids, such as in vascular applications like a vascular graft, a stent cover or a catheter balloon; and medical devices or implants comprising said porous hybrid films. ## Claims ### Claim 1 A porous hybrid film, comprising a porous polyolefin film wherein at one or more isolated areas forming 0.02-40 area % of the surface of the film, pores in a volume segment of the film across its thickness are at least partly filled with an elastomer at an amount of at least 20 vol % of the volume of the pores, and wherein outside said isolated areas the polyolefin film is substantially devoid of the elastomer, wherein the polyolefin is ultra-high molar mass polyethylene (UHMWPE) and wherein the elastomer is a thermoplastic polyurethane (TPU). ### Claim 2 (depends on 1) The porous hybrid film according to claim 1, wherein the polyolefin film is a microporous ultra-high molar mass polyethylene (UHMWPE) film having a thickness of 0.5-50 μm. ### Claim 3 (depends on 1) The porous hybrid film according claim 1, wherein an isolated area is a substantially circular spot on the film with a diameter of at most 5 mm or an elongated stripe with a width of at most 5 mm. ### Claim 4 (depends on 1) The porous hybrid film according to claim 1, wherein the pores at an isolated area are at least 50 vol % filled with elastomer. ### Claim 5 (depends on 1) The porous hybrid film according to claim 1, wherein the isolated areas constitute 0.2-25 area % of the surface of the film. ### Claim 6 (depends on 1) The porous hybrid film according to claim 1, wherein the elastomer is a thermoplastic polyurethane comprising an aliphatic polyether and/or an aliphatic polycarbonate as soft block. ### Claim 7 (depends on 6) The porous hybrid film according to claim 6, wherein the thermoplastic polyurethane comprises an apolar endgroup. ### Claim 8 (depends on 7) The porous hybrid film according to claim 7, wherein the apolar endgroup comprises a C2-C20 alkyl, a C2-C16 fluoroalkyl, a C2-C16 fluoroalkyl ether, a poly(alkylene oxide) or a polysiloxane. ### Claim 9 (depends on 1) The porous hybrid film according to claim 1, wherein the hybrid film has a porosity of 30-95 vol %. ### Claim 10 (depends on 1) The porous hybrid film according to claim 1, wherein the pores at an isolated area are at least 80 vol % filled with elastomer. ### Claim 11 (depends on 1) A medical device or implant comprising a porous hybrid film according to claim 1. ### Claim 12 (depends on 11) The medical device or implant according to claim 11, wherein the device or implant is a vascular graft, a vascular occlusion device, a stent cover, or a catheter balloon. ### Claim 13 (depends on 11) The medical device or implant according to claim 11, wherein the polyolefin film has a multitude of pores with maximum pore size of 50 μm as determined with a capillary flow porometer. ### Claim 14 (depends on 11) The medical device or implant according to claim 11, wherein the TPU contains a combination of an aliphatic polycarbonate and a polysiloxane as soft blocks. ### Claim 15 A method to increase tear resistance of a porous polyolefin film comprising steps of: a. providing a porous polyolefin film; b. identifying one or more locations on the film, at which locations tearing is likely to occur during intended use of the film; c. applying at the identified locations of the film an amount of a solution of an elastomer in solvent; and d. substantially removing the solvent; to result in a porous hybrid film having one or more isolated areas forming 0.02-40 area % of the surface of the film, in which areas pores in a volume segment across the thickness of the film are at least partly filled with the elastomer, wherein outside said areas the original porosity of the polyolefin film is substantially unchanged and wherein the polyolefin is ultra-high molar mass polyethylene (UHMWPE) and the elastomer is a thermoplastic polyurethane (TPU). ### Claim 16 (depends on 15) The method according to claim 15, wherein the TPU comprises one or more apolar endgroups. ### Claim 17 (depends on 16) The method according to claim 16, wherein the apolar endgroup comprises a C2-C20 alkyl, a C2-C16 fluoroalkyl, a C2-C16 fluoroalkyl ether, a poly(alkylene oxide) or a polysiloxane. ### Claim 18 (depends on 15) The method according to claim 15, wherein the solution of elastomer has a Brookfield viscosity of 1-500 mPa·s. ### Claim 19 (depends on 15) The method according to claim 15, further comprising the step of compressing the film as obtained at a temperature below the melting temperature of the polyolefin. ### Claim 20 (depends on 15) The method according to claim 15, wherein the TPU comprises an aliphatic polyether and/or an aliphatic polycarbonate as soft block. ### Claim 21 (depends on 15) The method according to claim 15, wherein the isolated area is a substantially circular spot with a diameter of at most 5 mm or an elongated stripe with a width of at most 5 mm. ### Claim 22 (depends on 15) A medical device or implant comprising a porous hybrid film obtained by the method according to claim 15. ### Claim 23 (depends on 22) The medical device or implant according to claim 22, wherein the device or implant is a vascular graft, a vascular occlusion device, a stent cover, or a catheter balloon.