# US 5,344,504 A · Treatment for galvanized metal

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,344,504 A
- Document ID: US5344504A
- Status: Granted
- Kind: A
- Application number: 08/080,901
- Filed: 1993-06-22
- Granted: 1994-09-06
- Earliest claimed: 1993-06-22
- Assignees: Betz Laboratories, Inc.
- Inventors: Philip D. Deck; Jeffrey I. Melzer; William L. Harpel
- Web page: https://patentgrep.com/patent/US5344504A

## CPC

- C23C 22/34: containing fluorides or complex fluorides
- C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04)

## Abstract

An aqueous coating solution for zinc containing metals such as galvanized iron and steel. The coating solution is resistent to the formation of zinc induced sludge and can be operated with little or no overflow. The aqueous treatment solution contains from 0.1 to 10 grams per liter of a fluorometallic acid, from 0.015 to 6 grams per liter of a salt of a transition metal, from 1 to 30 grams per liter zinc; and optionally from 0.1 to 3 grams per liter a polymer of acrylic acid, methacrylic acid, or an ester thereof with a C1 to C8 alkanol.

## Claims

### Claim 1

A method of forming a coating on a zinc galvanized metal, said coating having increased resistance to corrosion and having good adherence to a subsequently applied siccative coating in which said zinc galvanized metal is exposed to a coating solution bath comprising from about 0.1 to above 10 grams per liter, based on fluoride, a fluorometallic acid selected from the group consisting of HBF.sub.4, H.sub.2 SiF.sub.6, H.sub.2 TiF.sub.6, H.sub.2 ZrF.sub.6, the ammonium or alkali metal salts thereof; hydrofluoric acid or salts thereof; and mixtures thereof; from about 0.015 to about 6 grams per liter, based on metal content, of a salt of cobalt, copper, iron, manganese, nickel, strontium, zinc, or mixtures thereof; and optionally, from about 0 to about 3.0 grams per liter of a polymer selected from the group consisting of polyacrylic acid, polymethacrylic acid, and C1 to C8 alkanol esters thereof; wherein the pH of the solution is from about 4.0 to about 5.0 wherein the improvement comprises limiting overflow from said coating solution bath such that the concentration of zinc in said coating solution bath ranges from about 1.0 to about 30 grams per liter.