Process for manufacturing a porous transport layer

Patent metadata

Field	Value
Publication number	US-2025010370-A1
Application number	US-202218699938-A
Country	US
Kind code	A1
Filing date	Oct 7, 2022
Priority date	Oct 15, 2021
Publication date	Jan 9, 2025
Grant date	—

Abstract

The invention relates to a process for manufacturing a multilayered porous transport layer, the process comprising
(a) providing a first feedstock comprising first metal particles and a first polymer binder; and providing a second feedstock comprising second metal particles and a second polymer binder;
the first and the second feedstock having a metal powder content of 40 to 70% by volume; and the first feedstock having (i) metal particles with a smaller average particles size, (ii) a higher metal powder content, or (iii) both, metal particles with a smaller average particles size and a higher metal powder content compared to the second feedstock;
(b) coextruding the first and the second feedstock to form a film-shaped green body comprising a first layer and a second layer, the second layer being materially connected to the first layer above the melting temperature and or glass transition temperature of the first polymer binder and the second polymer binder; (c) optionally smoothening the film-shaped green body by rolling or calendering; (d) debinding the film-shaped green body to form a brown body; (e) sintering the brown body under a non-oxidative atmosphere or vacuum and a temperature of from 700 to 1300° C. to form the porous transport layer; wherein the first feedstock and the second feedstock are free of any solvents.

First claim

1 .- 16 . (canceled)

17 . A process for manufacturing a multilayered porous transport layer, the process comprising
(a) providing a first feedstock comprising first metal particles and a first polymer binder; and providing a second feedstock comprising second metal particles and a second polymer binder;
the first and the second feedstock having a metal powder content of 40 to 70% by volume; and
the first feedstock having
(i) metal particles with a smaller average particles size,
(ii) a higher metal powder content, or
(iii) both, metal particles with a smaller average particles size and a higher metal powder content
compared to the second feedstock;
(b) coextruding the first and the second feedstock to form a film-shaped green body comprising a first layer and a second layer, the second layer being materially connected to the first layer at temperatures above the melting temperature and or glass transition temperature of the first polymer binder and the second polymer binder; (c) optionally smoothing the film-shaped green body by rolling or calendering; (d) debinding the film-shaped green body to form a brown body; (e) sintering the brown body under a non-oxidative atmosphere or vacuum and a temperature of from 700 to 1100° C. to form the porous transport layer; wherein the first feedstock and the second feedstock are free of any solvents.

18 . The process according to claim 17 , wherein the first average particle size is of from 15 to 35 μm and the second average particle size is of from 25 to 45 μm.

19 . The process according to claim 17 , wherein the amount of the first metal powder in the first feedstock is from 54 to 65% by volume and the amount of the second metal powder in the second feedstock is from 48 to 56% by volume.

20 . The process according to claim 17 , wherein the first and the second metal particles consist of titanium or stainless steel.

21 . The process according to claim 17 , wherein the first feedstock and the second feedstocks have a melt flow rate between 50 to 700 g/10 min, according to ISO 1133 at 190° C. and 21.6 kg.

22 . The process according to claim 17 , wherein the first polymer binder, the second polymer binder, or both the first and the second polymer binder have a melt flow rate MFR according to ISO 1133-1 using 190° C. and 2.16 kg of 1 to 5 g/10 min.

23 . The process according to claim 17 , wherein the first polymer binder, the second polymer binder, or both the first and the second polymer binder comprise
(i) 35 to 55% by volume of a polyoxymethylene; (ii) 2 to 10% by volume of a polyolefin; (iii) optionally 2 to 20% by volume of a further polymer; and (iv) optionally 0.5 to 5% by volume of a dispersant.

24 . The process according to claim 17 , wherein the coextrusion is performed at a melt temperature of 175 to 220° C.

25 . The process according to claim 17 , wherein in the coextrusion step (c) a third layer is coextruded on top of the first or the second layer.

26 . The process according to claim 17 , wherein a smoothing is performed by rolling, calendering, or both rolling and calendering.

27 . The process according to claim 17 , wherein the debinding step (d) is performed in a gaseous acid comprising atmosphere.

28 . The process according to claim 17 , wherein the debinding step (d) comprises a catalytic debinding at a temperature of from 100 to 140° C.

29 . The process according to claim 24 , wherein the sintering step (e) is performed at temperatures of from 700 to 1000° C.

30 . A combination of a first feedstock and a second feedstock,
(a) the first feedstock comprising first metal particles and a first polymer binder; (b) the second feedstock comprising second metal particles and a second polymer binder; the first feedstock having (i) metal particles with a smaller average particles size, (ii) a higher metal powder content, or (iii) both, metal particles with a smaller average particles size and a higher metal powder content compared to the second feedstock; and wherein the melt flow rate MFR according to ISO 1133-1 using 190° C. and 2.16 kg of the first and the second polymer binder is from 1 to 5 g/10 min.

31 . A film-shaped green body obtained by performing steps (a) to (d) of the process according to claim 17 .

32 . A porous transport layer obtainable by the process according to claim 17 .

Assignees

• Basf Se

Inventors

• Madkour Sherif Aly Hassan Aly
• Malko Daniel
• Schmidt-Hansberg Benjamin

Classifications

• B32B2307/724

  Permeability to gases, adsorption · CPC title

• B32B2250/02

  2 layers · CPC title

• B32B7/02

  Physical, chemical or physicochemical properties · CPC title

• B32B5/30

  one layer {being formed of particles, e.g. chips,} granules, powder · CPC title

• B32B5/16

  characterised by features of a layer formed of particles, e.g. chips, powder {or granules (layer formed of natural mineral particles B32B19/00; layer being formed of wood fibres, chips or particles B32B21/02)} · CPC title