US 11,752,702 B2
Method for welding membranes
Martin Weber, Ludwigshafen (DE); Juergen Ahlers, Ludwigshafen (DE); Frank Prissok, Lemfoerde (DE); and Oliver Gronwald, Ludwigshafen (DE)
Assigned to BASF SE, Ludwigshafen am Rhein (DE)
Appl. No. 16/640,505
Filed by BASF SE, Ludwigshafen am Rhein (DE)
PCT Filed Aug. 30, 2018, PCT No. PCT/EP2018/073352
§ 371(c)(1), (2) Date Feb. 20, 2020,
PCT Pub. No. WO2019/043100, PCT Pub. Date Mar. 7, 2019.
Claims priority of application No. 17189070 (EP), filed on Sep. 1, 2017.
Prior Publication US 2020/0353697 A1, Nov. 12, 2020
Int. Cl. B29D 99/00 (2010.01); B29C 65/00 (2006.01); A43B 7/12 (2006.01); B29C 65/38 (2006.01); B29C 65/82 (2006.01); B32B 25/04 (2006.01); B32B 25/14 (2006.01); B29L 7/00 (2006.01); B29L 31/50 (2006.01)
CPC B29C 66/71 (2013.01) [A43B 7/125 (2013.01); B29C 65/38 (2013.01); B29C 65/8253 (2013.01); B29C 66/00141 (2013.01); B29C 66/1122 (2013.01); B29C 66/727 (2013.01); B29C 66/7352 (2013.01); B29C 66/919 (2013.01); B29C 66/949 (2013.01); B29D 99/005 (2013.01); B32B 25/042 (2013.01); B32B 25/14 (2013.01); B29L 2007/005 (2013.01); B29L 2031/501 (2013.01); B32B 2307/724 (2013.01); B32B 2437/00 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A process for welding porous membranes, the process comprising:
i) providing a first porous membrane and a second porous membrane;
ii) at least partially superimposing the first and second porous membranes to obtain an at least partial superimposition region;
iii) welding the first and second porous membranes at least in a portion of the at least one superimposition region at a temperature in the range from 100 to 300° C. and at a pressure in the range from 1 to 10 bar to obtain an at least partially welded composite of the first and second porous membranes;
wherein a material of the first and second porous membranes comprises at least one thermoplastic elastomer selected from the group consisting of a polyurethane elastomer, a polyester elastomer, a polyetherester elastomer, a polyesterester elastomer, a polyamide elastomer, a polyetheramide elastomer, a polystyrene elastomer, and an ethylene-vinyl acetate elastomer
the first and second porous membranes have pores having an average pore diameter of less than 2000 nm, determined by means of Hg porosimetry in accordance with DIN 66133 and
said first porous membrane and said second porous membrane are at least partially superimposed and are joined to one another in the form of a weld seam at least in a portion of said at least one superimposition region,
wherein said first and second porous membranes each have a pore size distribution between a first surface and a second surface of the respective membranes, wherein the pore size distribution is a gradient wherein a ratio of a pore diameter of pores at or close to the first surface to a pore diameter of pores at or close to the second surface is 1:5 to 1:10,000, and
an area of said weld seam has a water vapor permeability of 75% to 100% of a water vapor permeability of said first porous membrane.