	US 12,454,503 B2
	Process for producing superabsorbents
Monte Alan Peterson, Freeport, TX (US); Ronny De Kaey, Antwerp (BE); Karl Possemiers, Antwerp (BE); Juergen Schroeder, Ludwigshafen (DE); Ruediger Funk, Ludwigshafen (DE); and Matthias Weismantel, Ludwigshafen (DE)
Assigned to BASF SE, Ludwigshafen (DE)
Appl. No. 17/289,302
Filed by BASF SE, Ludwigshafen (DE)
PCT Filed Nov. 4, 2019, PCT No. PCT/EP2019/080013 § 371(c)(1), (2) Date Apr. 28, 2021, PCT Pub. No. WO2020/099154, PCT Pub. Date May 22, 2020.
Claims priority of application No. 18206122 (EP), filed on Nov. 14, 2018.
Prior Publication US 2021/0402373 A1, Dec. 30, 2021
Int. Cl. C07C 51/41 (2006.01); B01J 19/00 (2006.01); B01J 19/24 (2006.01); B01J 20/26 (2006.01); B01J 20/30 (2006.01)

CPC C07C 51/412 (2013.01) [B01J 19/0053 (2013.01); B01J 19/24 (2013.01); B01J 19/2435 (2013.01); B01J 19/2465 (2013.01); B01J 20/267 (2013.01); B01J 20/3021 (2013.01); B01J 2204/005 (2013.01); B01J 2219/185 (2013.01); B01J 2219/1942 (2013.01); B01J 2219/1945 (2013.01); B01J 2220/68 (2013.01)]

18 Claims

1. A process for producing superabsorbent polymer particles, comprising polymerizing a monomer solution, comprising

a) partly neutralized acrylic acid,

b) at least one crosslinker, and

c) at least one initiator,

drying a resulting polymer gel, optionally grinding and optionally classifying a resulting dried polymer gel and optionally thermally post-crosslinking and cooling resulting polymer particles, wherein the partly neutralized acrylic acid is formed by continuous mixing of acrylic acid, an aqueous solution of a base, and optionally water, an apparatus for preparing the partly neutralized acrylic acid comprises a ring line (R), a vessel (B), a heat exchanger (W), and a pump (P), wherein the vessel (B) has a cylindrical shape having a diameter d and a torispherical bottom, and the torispherical bottom has a dish having a radius r₁of 0.8 to 1.2 d and a toroidal shaped knuckle having a radius r₂of 0.06 to 0.17 d.