Continuous coil pretreatment process
AssigneeArconic Technologies LLC
InventorsMichael Bull, Theresa Elizabeth MacFarlane
Life of this patent
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Abstract
Described herein is a continuous coil pretreatment process used to treat the surface of an aluminum alloy sheet or coil for subsequent deposition of an acidic organophosphorus compound. The process can include applying a cleaner to a surface of an aluminum sheet or a coil; etching the surface of the aluminum sheet or the coil with an acidic solution; rinsing the surface of the aluminum sheet or the coil with deionized water; applying to the surface of the aluminum sheet or the coil a solution of an acidic organophosphorus compound; rinsing the surface of the aluminum sheet or the coil with deionized water; and drying the surface of the aluminum sheet or the coil.
Claims25
A continuous coil pretreatment process, the process comprising:
- (a) uncoiling a coil of an aluminum alloy sheet, wherein the aluminum alloy sheet comprises a 5xxx aluminum alloy or a 6xxx aluminum alloy;
- (b) removing residual oils from the aluminum alloy sheet;
- (c) heat treating of the aluminum alloy sheet, wherein, after the heat treating step and due to the removing step, surfaces of the aluminum alloy sheet are devoid of burnt oils;
- (d) applying a pretreatment solution to the heat treated aluminum alloy sheet, wherein the applying step occurs for up to 20 seconds, wherein the pretreatment solution comprises from 0.1 wt. % to 10 wt. % of a vinylphosphonic acid-acrylic acid copolymer, and wherein the applying step comprises producing a monolayer on the surface of the aluminum alloy sheet;
- (e) drying the aluminum alloy sheet;
- and
- (f) recoiling the aluminum alloy sheet.
A continuous coil pretreatment process, the process comprising:
- (a) applying a cleaner to a surface of an aluminum alloy sheet, wherein the applying comprises removing residual oils from the aluminum alloy sheet;
- (b) heat treating of the aluminum alloy sheet, wherein, after the heat treating step and due to the removing step, surfaces of the aluminum alloy sheet are devoid of burnt oils;
- and
- (c) applying a pretreatment solution to the heat treated aluminum alloy sheet, wherein the pretreatment solution comprises from 0.1 wt. % to 10 wt. % of a vinylphosphonic acid-acrylic acid copolymer.
A continuous coil pretreatment process, the process comprising:
- (a) uncoiling a coil of an aluminum alloy sheet, wherein the aluminum alloy sheet comprises a 5xxx aluminum alloy or a 6xxx aluminum alloy;
- (b) removing residual oils from the aluminum alloy sheet;
- (c) heat treating of the aluminum alloy sheet, wherein, after the heat treating step and due to the removing step, surfaces of the aluminum alloy sheet are devoid of burnt oils;
- (d) etching surfaces of the aluminum alloy sheet with an acid etch solution, thereby removing undesired oxide phases, wherein:
- (I) a dwell time of the etching step is not greater than 15 seconds;
- (II) the acid etch solution is at a temperature of from 55° C. to 85° C.,
- (III) the acid etch solution comprises from 1 to 15 vol. % of sulfuric acid, from 0.1 vol. % to 10 vol. % of a surfactant and from about 0.05 vol. % to 4 vol. % of an accelerator,
- (IV) the etching step comprises maintaining the acid etch solution to contain less than 1,000 ppm of aluminum (Al) and magnesium (Mg) ions;
- (e) first rinsing surfaces of the aluminum alloy sheet with a solvent, wherein the solvent comprises water, and wherein the first rinsing step is performed at a temperature ranging from 37° C. to 70° C.;
- (f) applying a pretreatment solution to the heat treated aluminum alloy sheet, wherein the applying step occurs for up to 20 seconds, wherein the pretreatment solution comprises from 0.1 wt. % to 10 wt. % of a vinylphosphonic acid-acrylic acid copolymer, and wherein the applying step comprises producing a monolayer on the surface of the aluminum alloy sheet, wherein the monolayer has a thickness of from 0.1 nm to 20 nm;
- (g) second rinsing the surface of the aluminum alloy sheet with an aqueous solution;
- (h) drying the aluminum alloy sheet;
- and
- (i) recoiling the aluminum alloy sheet;
- wherein a line speed of the continuous coil pretreatment process is in the range of from 15 to 100 meters per minute (mpm);
- and
- wherein between the drying step (h) and the recoiling step (i) the process is absent of any curing or chemical reaction steps.
Dependencies are inferred from the claim text.