# US 2021/0275974 A1 · Reverse osmosis membrane and manufacturing method therefor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0275974 A1 - Document ID: US20210275974A1 - Status: Published application - Kind: A1 - Application number: 16/332,622 - Filed: 2017-09-11 - Published: 2021-09-09 - Earliest claimed: 2016-09-12 - Assignees: SK Innovation Co., Ltd. - Applicants: SK Innovation Co., Ltd. - Inventors: Min Sang PARK; Sang Hyun PARK - Web page: https://patentgrep.com/patent/US20210275974A1 ## CPC - B01D 71/26: Polyalkenes - B01D 61/025: {Reverse osmosis; Hyperfiltration} - B01D 67/0006: {by chemical reactions (in-situ polymerisation, polycondensation, cross-linking or reaction for manufacturing composite membranes B01D69/125)} - B01D 69/02: characterised by their properties - B01D 69/107: {Organic support material} - B01D 69/1071: {Woven, non-woven or net mesh} - B01D 69/1251: {by interfacial polymerisation} - B01D 71/261: {Polyethylene} - B01D 71/262: {Polypropylene} - B01D 71/56: Polyamides, e.g. polyester-amides - C02F 1/441: {by reverse osmosis} - B01D 2325/02834: more than 0.1 and up to 1 µm - B01D 2325/04: Characteristic thickness - B01D 2325/24: Mechanical properties, e.g. strength - B01D 2325/36: Hydrophilic membranes - Y02A 20/131: Reverse-osmosis - 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) - C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) - Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE ## Abstract The present invention relates to a reverse osmosis membrane using a polyolefin-based microporous membrane and a production method therefor. The present invention relates to a method for forming a polyamide layer by interfacial polymerization on a polyolefin-based microporous membrane without separate hydrophilization treatment, wherein reaction solutions are fed in a specified order upon the interfacial polymerization to effectively form the polyamide layer on a polyolefin-based microporous membrane having hydrophobicity. ## Claims ### Claim 1 A production method for a reverse osmosis membrane comprising: contacting a polyolefin-based microporous membrane with a polyfunctional acyl halide organic solution, and then contacting the polyolefin-based microporous membrane with a polyfunctional amine aqueous solution to form a polyamide active layer. ### Claim 2 (depends on 1) The production method of claim 1, wherein the polyolefin-based microporous membrane has a water contact angle of more than 90 degrees. ### Claim 3 (depends on 1) The production method of claim 1, wherein the contacting is coating or immersion. ### Claim 4 (depends on 1) The production method of claim 1, wherein the polyolefin-based microporous membrane has a porosity of 20 to 70%, a maximum pore size measured by a bubble point method of 0.1 μm or less, and a multiplication of tensile strength and thickness in at least one of a transverse direction and a longitudinal direction is 0.3 kgf/cm or more. ### Claim 5 (depends on 1) The production method of claim 1, wherein the polyolefin-based microporous membrane is a film or a sheet. ### Claim 6 (depends on 1) The production method of claim 1, wherein the polyolefin-based microporous membrane is selected from: a single-layered microporous membrane made of any one selected from polyethylene, polypropylene, and a mixture thereof; a composite microporous membrane having two or more layers in which polyethylene and polypropylene are alternately stacked; and a multilayer microporous membrane in which two or more layers of polyethylene or polypropylene are stacked. ### Claim 7 (depends on 1) The production method of claim 1, wherein the polyfunctional acyl halide organic solution is obtained by dissolving a polyfunctional acyl halide compound in an aliphatic hydrocarbon-based organic solution, and the polyfunctional amine aqueous solution is obtained by dissolving a polyfunctional amine in water. ### Claim 8 A reverse osmosis membrane comprising: a polyamide active layer formed on a polyolefin-based microporous membrane, wherein the polyolefin-based microporous membrane has a water contact angle of more than 90 degrees. ### Claim 9 (depends on 8) The reverse osmosis membrane of claim 8, wherein the polyolefin-based microporous membrane has a porosity of 20 to 70%, a maximum pore size measured by a bubble point method of 0.1 μm or less, and a multiplication of tensile strength and thickness in at least one of a transverse direction and a longitudinal direction is 0.3 kgf/cm or more. ### Claim 10 (depends on 8) The reverse osmosis membrane of claim 8, wherein the polyolefin-based microporous membrane is selected from: a single-layered microporous membrane made of any one selected from polyethylene, polypropylene, and a mixture thereof; a composite microporous membrane having two or more layers in which polyethylene and polypropylene are alternately stacked; and a multilayer microporous membrane in which two or more layers of polyethylene or polypropylene are stacked.