Surface-treatment solution composition containing trivalent chromium and inorganic compound, zinc-based plated steel sheet surface-treated using same, and method for producing same

Patent metadata

Field	Value
Publication number	US-10822705-B2
Application number	US-201716339888-A
Country	US
Kind code	B2
Filing date	Sep 29, 2017
Priority date	Oct 10, 2016
Publication date	Nov 3, 2020
Grant date	Nov 3, 2020

Abstract

Provided is a surface-treating solution composition, a zinc-based plated steel sheet surface-treated using the same, and a method for producing the same, wherein the surface-treatment solution composition includes: 10 wt % to 20 wt % of a trivalent chromium compound containing chromium phosphate (A) and chromium nitrate (B), the content ratio thereof, A/(A+B), satisfying 0.3 to 0.6; 20 wt % to 40 wt % of a silane-based sol-gel resin in which three types of silane compounds are crosslinked; 0.2 wt % to 0.4 wt % of a rust-inhibiting and corrosion-resistant agent; 0.1 wt % to 0.3 wt % of a molybdenum-based compound; 5 wt % to 10 wt % of a water-soluble cationic urethane resin; 0.5 wt % to 2.0 wt % of a silane coupling agent; 0.5 wt % to 2.0 wt % of an Al compound; and 25.3 wt % to 63.7 wt % of water. The zinc-based plated steel sheet surface-treated with the surface-treatment solution composition containing trivalent chromium has an excellent effect on corrosion resistance, blackening resistance, fingerprint resistance, piping oil infiltration, and alkali resistance.

First claim

The invention claimed is:

1. A surface-treatment solution composition for a zinc-based plated steel sheet, comprising:
10 wt % to 20 wt % of a trivalent chromium compound containing chromium phosphate (A) and chromium nitrate (B);
20 wt % to 40 wt % of a silane-based sol-gel resin in which three types of silane compounds are crosslinked;
0.2 wt % to 0.4 wt % of a rust-inhibiting and corrosion-resistant agent;
0.1 wt % to 0.3 wt % of a molybdenum-based compound;
5 wt % to 10 wt % of a water-soluble cationic urethane resin;
0.5 wt % to 2.0 wt % of a silane coupling agent;
0.5 wt % to 2.0 wt % of an Al compound; and
25.3 wt % to 63.7 wt % of water.

2. The surface-treatment solution composition according to claim 1 , wherein the chromium phosphate (A) and the chromium nitrate (B) satisfy a content ratio A/(A+B) of 0.3 to 0.6.

3. The surface-treatment solution composition according to claim 1 , wherein the rust-inhibiting and corrosion-resistant agent is one or more selected from the group consisting of a fluorine-based rust inhibitor (excluding molybdenum fluoride), a vanadium-based rust inhibitor (excluding a fluorine compound), a cerium salt-based rust inhibitor (excluding a fluorine compound), and a cobalt-based rust inhibitor (excluding a fluorine compound).

4. The surface-treatment solution composition according to claim 1 , wherein the molybdenum-based compound is one or more selected from the group consisting of molybdenum oxide, molybdenum sulfide, molybdenum acetate, molybdenum phosphate, molybdenum carbide, molybdenum chloride, molybdenum fluoride, and molybdenum nitride.

5. The surface-treatment solution composition according to claim 1 , wherein the silane coupling agent is one or more selected from the group consisting of 2-(3,4-epoxycyclohexyl)-ethyl trimethoxysilane, 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl methyldiethoxysilane, 3-glycidoxypropyl triethoxysilane, N-2-(aminoethyl)-3-aminopropyl methyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyl trimethoxysilane, N-2-(amino ethyl)-3-aminopropyl triethoxysilane, 3-aminopropyl trimethoxysilane, 3-aminopropyl triethoxysilane, 3-ureidopropyl trimethoxysilane, and 3-ureidopropyl trialkoxysilane.

6. The surface-treatment solution composition according to claim 1 , wherein the three types of silane compounds comprise:
one type of first silane selected from the group consisting of tetraethylorthosilicate, tetramethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, and dimethyldiethoxysilane;
one type of second silane selected from the group consisting of 3-glycidoxypropyl trimethoxysilane, 2-(3,4-epoxycyclohexyl)-ethyl trimethoxysilane, 3-glycidoxypropyl trimethoxysilane, and 3-glycidoxypropyl methyldiethoxysilane; and
one type of third silane selected from the group consisting of 3-aminopropyl triethoxysilane, N-2-(aminoethyl)-3-aminopropyl methyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyl trimethoxysilane, and N-2-(aminoethyl)-3-aminopropyl triethoxysilane.

7. A surface-treated zinc-based plated steel sheet comprising:
a steel sheet;
a zinc-based plated layer formed on at least one surface of the steel sheet; and
a trivalent chromate film layer formed on the zinc-based plated layer,
wherein the trivalent chromate film layer comprises:
31.47 wt % to 35.23 wt % of a trivalent chromium compound containing chromium phosphate (A) and chromium nitrate (B);
32.49 wt % to 36.36 wt % of a silane-based sol-gel resin in which three types of silane compounds are crosslinked;
2.03 wt % to 2.27 wt % of a rust-inhibiting and corrosion-resistant agent;
1.14 wt % to 1.52 wt % of a molybdenum-based compound;
12.18 wt % to 13.64 wt % of a urethane resin;
5.68 wt % to 10.15 wt % of a silane coupling agent; and
5.68 wt % to 10.15 wt % of an Al compound.

8. The surface-treated zinc-based plated steel sheet according to claim 7 , wherein the chromium phosphate (A) and chromium nitrate (B) satisfy a content ratio A/(A+B) of 0.89 to 0.95.

9. The surface-treated zinc-based plated steel sheet according to claim 7 , wherein the rust-inhibiting and corrosion-resistant agent is one or more selected from the group consisting of a fluorine-based rust inhibitor (excluding molybdenum fluoride), a vanadium-based rust inhibitor (excluding a fluorine compound), a cerium salt-based rust inhibitor (excluding a fluorine compound), and a cobalt-based rust inhibitor (excluding a fluorine compound).

10. The surface-treated zinc-based plated steel sheet according to claim 7 , wherein the molybdenum-based compound is one or more selected from the group consisting of molybdenum oxide, molybdenum sulfide, molybdenum acetate, molybdenum phosphate, molybdenum carbide, molybdenum chloride, molybdenum fluoride, and molybdenum nitride.

11. The surface-treated zinc-based plated steel sheet according to claim 7 , wherein the silane coupling agent is one or more selected from the group consisting of 2-(3,4-epoxycyclohexyl)-ethyl trimethoxysilane, 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl methyldiethoxysilane, 3-glycidoxypropyl triethoxysilane, N-2-(aminoethyl)-3-aminopropyl methyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyl trimethoxysilane, N-2-(aminoethyl)-3-aminopropyl triethoxysilane, 3-aminopropyl trimethoxysilane, 3-aminopropyl triethoxysilane, 3-ureidopropyl trimethoxysilane, and 3-ureidopropyl trialkoxysilane.

12. The surface-treated zinc-based plated steel sheet according to claim 7 , wherein the trivalent chromate film layer has a thickness of 0.3 μm to 0.5 μm.

13. The surface-treated zinc-based plated steel sheet according to claim 7 , wherein the three types of silane compounds comprise:
one type of first silane selected from the group consisting of tetraethylorthosilicate, tetramethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, and dimethyldiethoxysilane;
one type of second silane selected from the group consisting of 3-glycidoxypropyl trimethoxysilane, 2-(3,4-epoxycyclohexyl)-ethyl trimethoxysilane, 3-glycidoxypropyl trimethoxysilane, and 3-glycidoxypropyl methyldiethoxysilane; and
one type of third silane selected from the group consisting of 3-aminopropyl triethoxysilane, N-2-(aminoethyl)-3-aminopropyl methyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyl trimethoxysilane, and N-2-(aminoethyl)-3-aminopropyl triethoxysilane.

14. A method for producing a surface-treated zinc-based plated steel sheet, comprising:
coating a surface-treatment solution composition on a zinc-based plated steel sheet on which a zinc-based plated layer is formed; and
drying the coated surface-treatment solution composition to form a trivalent chromate film layer,
wherein the surface-treatment solution composition comprises:
10 wt % to 20 wt % of a trivalent chromium compound containing chromium phosphate (A) and chromium nitrate (B);
20 wt % to 40 wt % of a silane-based sol-gel resin in which three types of silane compounds are crosslinked;
0.2 wt % to 0.4 wt % of a rust-inhibiting and corrosion-resistant agent;
0.1 wt % to 0.3 wt % of a molybdenum-based compound;
5 wt % to 10 wt % of a water-soluble cationic urethane resin;
0.5 wt % to 2.0 wt % of a silane coupling agent;
0.5 wt % to 2.0 wt % of an Al compound; and
25.3 wt % to 63.7 wt % of water.

15. The method according to claim 14 , wherein the chromium phosphate (A) and the chromium nitrate (B) satisfy a content ratio A/(A+B) of 0.3 to 0.6.

16. The method according to claim 14 , wherein the rust-inhibiting and corrosion-resistant agent is one or more selected from the group consisting of a fluorine-based ru

Assignees

• Posco

Inventors

• Cho Soo-Hyoun
• Son Won-Ho
• Choi Chang-Hoon

Classifications

• C23C2222/10

  Use of solutions containing trivalent chromium but free of hexavalent chromium · CPC title

• C23C22/42 Primary

  containing also phosphates · CPC title

• C23C28/345

  with at least one oxide layer · CPC title

• C23C28/3225

  with at least one zinc-based layer · CPC title

• 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