	US 12,203,173 B2
	Alternative composition and alternative method for effectively phosphating metal surfaces
Timo Christoph Ceglarek, Frankfurt am Main (DE); and Hardy Wietzoreck, Frankfurt am Main (DE)
Assigned to CHEMETALL GMBH, Frankfurt (DE)
Appl. No. 17/425,042
Filed by Chemetall GmbH, Frankfurt (DE)
PCT Filed Jan. 23, 2020, PCT No. PCT/EP2020/051585 § 371(c)(1), (2) Date Jul. 22, 2021, PCT Pub. No. WO2020/156913, PCT Pub. Date Aug. 6, 2020.
Claims priority of application No. 19154196 (EP), filed on Jan. 29, 2019.
Prior Publication US 2022/0119957 A1, Apr. 21, 2022
Int. Cl. C23C 22/12 (2006.01); C23C 22/18 (2006.01); C23C 22/36 (2006.01); C23C 22/82 (2006.01); C23C 22/07 (2006.01)

CPC C23C 22/365 (2013.01) [C23C 22/82 (2013.01)]

20 Claims

1. An acidic, aqueous composition for phosphating metallic surfaces, which comprises zinc ions, manganese ions, phosphate ions, at least one accelerator of a formula (I) below,

R₁R₂R₃C—NO₂ (I),

and optionally nickel ions,

wherein each of the substituents R₁, R₂and R₃on the carbon atom is selected, independently of the others, from the group consisting of hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 1-hydroxypropyl, 2-hydroxypropyl, 3-hydroxypropyl, 1-hydroxy-1-methylethyl and 2-hydroxy-1-methylethyl.