# US 5,344,560 A · Process for producing filtration membranes having amino acids that are capable of adsorbing proteins > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,344,560 A - Document ID: US5344560A - Status: Granted - Kind: A - Application number: 08/135,423 - Filed: 1993-10-12 - Granted: 1994-09-06 - Earliest claimed: 1990-05-10 - Assignees: Japan Atomic Energy Research Institute - Inventors: Takanobu Sugo; Kyoichi Saito - Web page: https://patentgrep.com/patent/US5344560A ## CPC - B01D 15/00: Separating processes involving the treatment of liquids with solid sorbents; Apparatus therefor - B01D 15/1896: {Membrane chromatography or membrane adsorbers} - B01D 67/00931: {by introduction of specific groups after membrane formation, e.g. by grafting} - B01J 20/261: {obtained by reactions only involving carbon to carbon unsaturated bonds (macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds per se C08F)} - B01J 20/264: {derived from different types of monomers, e.g. linear or branched copolymers, block copolymers, graft copolymers} - B01J 20/265: {modified or post-treated polymers (polymer carriers or substrates subjected to further impregnating or coating B01J20/3208)} - B01J 20/28038: {Membranes or mats made from fibers or filaments} - B01J 20/28078: {Pore diameter} - B01J 20/321: {consisting of a polymer obtained by reactions involving only carbon to carbon unsaturated bonds} - B01J 20/3278: {Polymers being grafted on the carrier} - B01J 20/328: {Polymers on the carrier being further modified} - B01D 15/3804: {Affinity chromatography} - B01D 2323/385: involving radiation - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS ## Abstract There is described a process for producing a filtration membrane that is also capable of adsorbing proteins. The process comprises the steps of subjecting a porous polymeric substrate to a graft polymerization reaction with a polymerizable monomer under exposure to an ultraviolet radiation or an ionizing radiation and thereafter bringing an amino acid into contact with the resulting graft membrane for immobilization. The amino acid is contained in an amount of 0.01-1 millimole per gram of the porous polymeric substrate. The polymerizable monomer to be grafted onto the porous polymeric substrate contains an epoxy group. ## Claims ### Claim 1 A process for producing a filtration membrane that is also capable of adsorbing proteins, comprising: subjecting a porous polymeric substrate made of a homo- or copolymer of an olefin or a halogenated olefin and a polymerizable epoxy group containing monomer to a graft polymerization reaction to form graft chains on the substrate, said graft polymerization reaction occurring upon exposure to ultraviolet or ionizing radiation, and immobilizing an amino acid to the graft chains by forming a covalent bond between the epoxy group of the graft chains and the amino group of the amino acid. ### Claim 2 (depends on 1) A process according to claim 1 wherein said porous polymeric substrate is in the form of either a flat membrane or an assembly of hollow fibers and has an average pore size of 0.01-10 .mu.m. ### Claim 3 (depends on 1) A process according to claim 1 wherein the amino acid is contained in an amount of 0.01-1 millimole per gram of the porous polymeric substrate. ### Claim 4 (depends on 1) A process according to claim 1 wherein the polymerizable epoxy group-containing monomer is selected from the group consisting of glycidyl methacrylate, glycidyl acrylate, glycidyl metaitaconate, ethylglydicyl maleate and glycidyl vinyl sulfonate. ### Claim 5 (depends on 1) A process according to claim 1 wherein the amino acid is selected from the group consisting of phenylalanine, tryptophan and histidine. ### Claim 6 (depends on 1) A process according to claim 1 wherein the homopolymer or halogenated homopolymer is selected from the group consisting of polyethylene, polypropylene and polytetrafluoroethylene, and wherein the copolymer or halogenated copolymer is a copolymer of monomers selected from the group consisting of ethylene, propylene, tetrafluoroethylene and chlorotrifluoroethylene. ### Claim 7 (depends on 1) The process of claim 1 wherein the amino acid is immobilized on the graft membrane by contacting the graft membrane with an aqueous solution of amino acids. ### Claim 8 A filtration membrane prepared by a process comprising: subjecting a porous polymeric substrate made of a homo- or copolymer of an olefin or a halogenated olefin and a polymerizable epoxy group-containing monomer to a graft polymerization reaction to form graft chains on the substrate, said graft polymerization reaction occurring upon exposure to ultraviolet or ionizing radiation, and immobilizing an amino acid to the graft chains by forming a covalent bond between the epoxy group of the graft chains and the amino group of the amino acid. ### Claim 9 (depends on 8) A filtration membrane according to claim 8 wherein said porous polymeric substrate is in the form of a flat membrane or an assembly of hollow fibers and has an average pore size of 0.01-10 .mu.m. ### Claim 10 (depends on 8) A filtration membrane according to claim 8 wherein the amino acid is contained in an amount of 0.01-1 millimole per gram of the porous polymeric substrate. ### Claim 11 (depends on 8) A filtration membrane according to claim 8 wherein the polymerizable epoxy group-containing monomer is selected from the group consisting of glycidyl methacrylate, glycidyl acrylate, glycidyl metaitaconate, ethylglydicyl maleate and glycidyl vinyl sulfonate. ### Claim 12 (depends on 8) A filtration membrane according to claim 8 wherein the amino acid is selected from the group consisting of phenylalanine, tryptophan and histidine. ### Claim 13 (depends on 8) A filtration membrane according to claim 8 wherein the homopolymer or halogenated homopolymer is selected from the group consisting of polyethylene, polypropylene and polytetrafluoroethylene and wherein the copolymer or halogenated copolymer is a copolymer of monomers selected from the group consisting of ethylene, propylene, tetrafluoroethylene and chlorotrifluoroethylene.