Support substrate for separation membrane
AssigneeAsahi Kasei Fibers Corporation
InventorsMinoru Yoshida, Ryuji Suzuka
Life of this patent
Estimating the term…
Abstract
A separation membrane support substrate comprising (1) a front layer having at least one layer comprising thermoplastic resin filaments with a single filament diameter of 7-30 μm; (2) a middle layer having at least one layer comprising melt blown fibers with a single fiber diameter of no greater than 5 μm, and a fiber basis weight of at least 1 g/m2 and comprising no more than 30 wt % of the total fiber basis weight; (3) a back layer having at least one layer comprising thermoplastic resin filaments with a single filament diameter of 7-20 μm, and has a fiber basis weight of 3-40 g/m2; (4) the laminated nonwoven fabric has an apparent density of 0.67-0.91 g/cm3; and (5) the laminated nonwoven fabric has a thickness of 45-110 μm.
Claims3
1-8. (canceled)
A process for production of a separation membrane support substrate comprising
- (a) spinning a thermoplastic resin filament on a conveyor using a thermoplastic resin with a melting point of 180° C. or higher to form at least one nonwoven fabric layer,
- (b) laminating at least one layer of fibers with a crystallinity of 15-40% and a fiber diameter of no greater than 5 μm, composed of a thermoplastic resin with a melting point of 180° C. or higher by melt blowing said fibers over said at least one nonwoven fabric layer,
- (c) laminating to said at least one layer formed by melt blowing, at least one layer of nonwoven fabric of thermoplastic resin filaments composed of a thermoplastic resin with a melting point of 180° C. or higher, and
- (d) heat bonding at a temperature of 50-120° C. below the melting point of the thermoplastic resin filaments using a flat roll at a line pressure of 100-1000 N/cm, after which a calender treatment is carried out at a temperature of at least 10° C. higher than the temperature of said heat bonding and 10-100° C. lower than the melting point of the thermoplastic resin filaments, at a line pressure of 100-1000 N/cm.
Dependencies are inferred from the claim text.