# US 11,998,879 B2 · Semipermeable membrane support

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- Number: US 11,998,879 B2
- Document ID: US11998879B2
- Status: Granted
- Kind: B2
- Application number: 16/494,114
- Filed: 2018-03-23
- Published: 2020-03-05
- Granted: 2024-06-04
- Earliest claimed: 2017-03-24
- Assignees: Mitsubishi Paper Mills Limited
- Applicants: Mitsubishi Paper Mills Limited
- Inventors: Keisuke Oyama; Yusuke Shimizu; Takahito Ochiai; Takao Masuda
- Web page: https://patentgrep.com/patent/US11998879B2

## CPC

- B01D 71/261: {Polyethylene}
- B01D 69/02: characterised by their properties
- B01D 69/1071: {Woven, non-woven or net mesh}
- B01D 71/262: {Polypropylene}
- D01D 5/34: Core-skin structure; Spinnerette packs therefor
- D01F 8/06: with at least one polyolefin as constituent
- D04H 1/5412: {sheath-core}
- D04H 1/5418: {Mixed fibres, e.g. at least two chemically different fibres or fibre blends}
- D04H 1/544: Olefin series
- B01D 2325/24: Mechanical properties, e.g. strength
- D04H 1/5414: {side-by-side}
- D10B 2321/021: polyethylene
- D10B 2321/022: polypropylene
- D10B 2401/20: optical
- D10B 2505/04: Filters
- 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)
- D01D: MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- D01F: CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D04H: MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL (weaving D03; knitting D04B; braiding D04C; net-making D04G; sewing D05B; tufting D05C; finishing non-woven fabrics D06); FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING {; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION}(non-woven fabrics having an intermediate or external layer of a different kind, e.g. of woven fabric, B32B)
- D10B: INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
- Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE

## Abstract

A semipermeable membrane support containing polyolefin-based fibers, which can withstand repeated washing and backwashing, makes it easy for a semipermeable membrane component to permeate thereinto and difficult for the component to strike therethrough, and is excellent in adhesion to the semipermeable membrane and adhesion between a non-coating surface thereof and a resin frame. The semipermeable membrane support which is used by forming the semipermeable membrane thereon is a wet-laid nonwoven fabric containing core-sheath type conjugate fibers composed of polypropylene as a core component and polyethylene as a sheath component and has a burst strength of 300 to 1,000 kPa, or the Bekk smoothness and 75° mirror surface glossiness of the coating surface on which the semipermeable membrane is to be formed of the semipermeable membrane support being more than the Bekk smoothness and 75° mirror surface glossiness of a non-coating surface on the opposite side.

## Claims

### Claim 1

A semipermeable membrane support used by forming a semipermeable membrane thereon, which is a wet-laid nonwoven fabric consisting of core-sheath type conjugate fibers consisting of polypropylene as a core component and polyethylene as a sheath component, wherein
the core-sheath type conjugate fibers are core-sheath type conjugate fibers A having an average fiber diameter of more than 9 μm to not more than 11 μm, and a content of the core-sheath type conjugate fibers A is 100 mass %,
a Bekk smoothness and a 75° mirror surface glossiness of a coating surface on which a semipermeable member is to be formed of the semipermeable membrane support are more than a Bekk smoothness and a 75° mirror surface glossiness of a non-coating surface on an opposite side,
the Bekk smoothness of the coating surface on which the semipermeable membrane is to be formed of the semipermeable membrane support is 1.0 to 51.0 seconds and a ratio of the Bekk smoothness of the coating surface to that of the non-coating surface is 1.3:1.0 to 1.1:1.0, and
the 75° mirror surface glossiness in a MD direction of the coating surface of the semipermeable membrane support is 10 to 30%, the 75° mirror surface glossiness in a CD direction of the coating surface of the semipermeable membrane support is 8 to 25%, and a ratio of the surface glossiness in the MD direction of the coating surface to that of the non-coating surface is 1.0:0.9 to 1.0:0.7.