Phosphate-free cleaner for metallic surfaces with reduced pickling erosion
AssigneeChemetall GmbH
InventorsAndre Schaus, Dominic Weil
Life of this patent
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Abstract
Described herein is a water-based, alkaline cleaner concentrate for producing a cleaner for metallic surfaces, the concentrate including a) at least one (meth)acrylic acid homopolymer having a weight-average molar mass in the range from 3 000 to 19 000 g/mol and b) at least one (meth)acrylic acid copolymer having a weight-average molar mass in the range from 50 000 to 100 000 g/mol. Also described herein are a corresponding cleaner for metallic surfaces with reduced pickling erosion, a process for anticorrosive treatment of metallic surfaces that includes a corresponding cleaning step, a metallic surface obtained by the process, and a method of use thereof in the sector of the metalworking industries.
Claims11
A water-based, alkaline cleaner concentrate for producing a cleaner for metallic surfaces, which comprises
- a) at least one (meth)acrylic acid homopolymer, wherein the at least one (meth)acrylic acid homopolymer is polyacrylic acid having a weight-average molar mass in the range from 5000 to 15000 g/mol and
- b) at least one (meth)acrylic acid copolymer, wherein the at least one (meth)acrylic acid copolymer is poly(acrylic acid-alt-maleic acid) having a weight-average molar mass in the range from 55000 to 90000 g/mol,
- wherein the at least one (meth)acrylic acid homopolymer of component a) and the at least one (meth)acrylic acid copolymer of component b) are present in a weight ratio in the range from 1.0:1 to 2.5:1;
- and
- wherein the at least one (meth)acrylic acid homopolymer of component a) is present in a concentration of at least 1.0 wt % but of at most 2.5 wt %, whereas the at least one (meth)acrylic acid copolymer of component b) is present in a concentration of at least 0.5 wt % but of at most 1.5 wt %.
Dependencies are inferred from the claim text.