Composition for steel sheet surface coating and steel sheet surface-coated with same

Patent metadata

Field	Value
Publication number	US-12054643-B2
Application number	US-201917266194-A
Country	US
Kind code	B2
Filing date	Aug 7, 2019
Priority date	Aug 8, 2018
Publication date	Aug 6, 2024
Grant date	Aug 6, 2024

Abstract

Provided is a composition for steel sheet surface coating, the composition comprising colloidal silica, a silane, a monomer, an organic resin, an acidity adjuster, a long-term corrosion-resistance improver, and a solvent; and a steel sheet coated with the composition. The steel sheet has excellent acid resistance, and maintains thickness uniformity thereof even when exposed to an acid for an extended period of time.

First claim

The invention claimed is:

1. A composition for steel sheet surface coating comprising, in terms of solid content weight:
30 to 50 wt % of colloidal silica;
40 to 60 wt % of silane;
5 to 15 wt % of a monomer;
0.1 to 5.0 wt % of an organic resin;
0.01 to 1.00 wt % of an acidity regulator; and
0.01 to 12 wt % of a long-term corrosion resistance improver,
wherein the long-term corrosion resistance improver is a compound containing cerium (Ce).

2. The composition of claim 1 , wherein a particle size of the colloidal silica is 5 nm to 50 nm.

3. The composition of claim 1 , wherein the silane has three or more alkoxy groups.

4. The composition of claim 3 , wherein the silane is one or more selected from the group consisting of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, 3-methacryloxypropyltrimethoxysilane, 2-glycidyloxypropyltrimethoxysilane, 2-glycidyloxypropyltriethoxysilane, 2-aminopropyltriethoxysilane, 2-ureidoalkyltriethoxysilane, tetraethoxysilane, triethoxyphenylsilane, and trimethoxyphenylsilane.

5. The composition of claim 1 , wherein the monomer is one or more selected from the group consisting of glacial acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, isobutyl acrylate, tert-butyl acrylate, tert-butyl methacrylate, butanediol monoacrylate, lauryl acrylate, dimethylaminoethyl acrylate, and dihydrodicyclopentadienyl acrylate.

6. The composition of claim 1 , wherein the organic resin is one or more selected from the group consisting of polyvinyl alcohol, poly(meth)acrylic acid, a copolymer of acrylic acid and methacrylic acid, a copolymer of ethylene and (meth)acrylic acid, a copolymer of ethylene and (meth)acrylate, a copolymer of ethylene and vinyl acetate, polyurethane, an amino-modified phenolic resin, a polyester resin, and an epoxy resin.

7. The composition of claim 1 , wherein the acidity regulator is one or more selected from the group consisting of acetic acid, formic acid, lactic acid, gluconic acid, sulfuric acid, nitric acid, hydrochloric acid, and hydrofluoric acid.

8. The composition of claim 1 , wherein the long-term corrosion resistance improver is one or more selected from the group consisting of cerium(III) nitrate, hydronium cerium nitrate hydrate, cerium nitrate hexahydrate, cerium(IV) nitrate, dipotassium diaquapentanitratocerate, dipotassium hexanitratocerate, tripotassium dicerium nitrate, diammonium diaquapentanitratocerate dihydrate, dirubidium diaquapentanitratocerate dihydrate, dicesium diaquapentanitratocerate dihydrate, ditalum diaquapentanitratocerate dihydrate, bis-4-(4H-1,2,4-triazol-4-yl)iminomethyl pyridinium diaquapentanitratocerate, 1,10-phenanthroline-H-diaquapentanitratocerate, hydronium cerium nitrate hydrate, ceric magnesium nitrate, ceric zinc nitrate, ceric nickel nitrate, ceric cobalt nitrate, and ceric manganese nitrate.

9. The composition of claim 1 , further comprising a solvent,
wherein the solvent is contained in an amount of 1 to 15 wt % with respect to a total weight of the composition containing the solvent.

10. The composition of claim 9 , wherein the solvent is one or more selected from the group consisting of methanol, ethanol, 2-propanol, 2-methoxypropanol, and 2-butoxyethanol.

11. A surface-coated steel sheet having a coating layer formed on a surface coated with the composition of claim 1 .

12. The surface-coated steel sheet of claim 11 , wherein a thickness of the coating layer is 0.1 to 50 μm.

13. The surface-coated steel sheet of claim 11 , wherein after the steel sheet is immersed in an aqueous solution of 50 vol % sulfuric acid at 70° C. for 6 hours, corrosion loss of the steel sheet is less than 15 mg/cm 2 ·hr.

14. The surface-coated steel sheet of claim 11 , wherein after the steel sheet is immersed in a mixed aqueous solution of 16.9 vol % sulfuric acid and 0.35 vol % hydrochloric acid at 60° C. for 6 hours, corrosion loss of the steel sheet is less than 3 mg/cm 2 ·hr.

15. The surface-coated steel sheet of claim 11 , wherein after the steel sheet is immersed in an aqueous solution of 50 vol % sulfuric acid at 70° C. for 96 hours, the thinnest thickness of a specimen is 25% or more of an initial thickness.

Assignees

• Posco
• Noroo Coil Coatings Co Ltd
• Posco Co Ltd

Inventors

• Choi Chang-Hoon
• Kim Dong-Yun
• Son Won-Ho
• Eun Hee-Jea
• Ko Jae-Duck

Classifications

• C09D4/00 Primary

  Coating compositions, e.g. paints, varnishes or lacquers, based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond {; Coating compositions, based on monomers of macromolecular compounds of groups C09D183/00 - C09D183/16} · CPC title

• C09D5/084

  Inorganic compounds · CPC title

• C09D4/06

  {Organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond} in combination with a macromolecular compound other than an unsaturated polymer of groups C09D159/00 - C09D187/00 · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title