Roll coating-based preparation methods for adhesive bonding of aluminum alloys, and products relating to the same
Methods for preparing an aluminum alloy sheet product for adhesive bonding are disclosed. A method may include preparing an aluminum alloy product for roll coating and roll coating an aqueous functionalization solution onto the prepared aluminum alloy product. For the roll coating step, the aqueous functionalization solution may include from 0.1 to 5.0 wt. % of active ingredients. The active ingredients may include a first monomer component and a second polymer component. The amount of second polymer component in the aqueous functionalization solution may be greater than an amount of the first monomer component in the aqueous functionalization solution.
1 . A method comprising:
(a) preparing an aluminum alloy product for roll coating having an upper surface and a lower surface, wherein the preparing comprises:
(i) contacting the aluminum alloy product with an alkaline cleaning solution;
(ii) first rinsing the aluminum alloy product;
(iii) contacting the aluminum alloy product with an acidic solution; and
(iv) second rinsing the aluminum alloy product;
(b) roll coating an aqueous functionalization solution onto the upper surface and the lower surface of the prepared aluminum alloy product, wherein the roll coating comprises:
(i) contacting an upper surface of the prepared aluminum alloy product with a first roller, wherein the first roller is in liquid communication with a first bath comprising a first aqueous functionalization solution having a first concentration of active ingredients; and
(ii contacting a lower surface of the prepared aluminum alloy product with a second roller, wherein the second roller is in liquid communication with a second bath comprising a second aqueous functionalization solution having a second concentration of the active ingredients;
(c) drying the roll coated aluminum alloy product, wherein the drying includes maintaining a peak metal temperature from 150° F. to 300° F.;
wherein the active ingredients comprises a monomer component and a copolymer component;
wherein the first concentration of the active ingredients of the first aqueous functionalization solution is from 0.1-4.75 wt. %;
wherein the second concentration of the active ingredients of the second aqueous functionalization solution is from 0.35-5.0 wt. %;
wherein the first concentration is at least 0.25 wt. % less than the second concentration of active ingredients;
wherein, at least partially due to the first concentration, the upper surface of the aluminum alloy product realizes a post-drying coating weight of from 0.21 to 3.55 mg/m 2 ;
wherein, at least partially due to the second concentration, the lower surface of the aluminum alloy product realizes a post-drying coating weight of from 0.21 to 3.55 mg/m 2 ;
wherein the first aqueous functionalization solution comprises a first ratio of the monomer component to the copolymer component, wherein the first ratio of the monomer component to the copolymer component is from 1:19 to 7:13 (monomer component: copolymer component);
wherein the second aqueous functionalization solution comprises a second ratio of the monomer component to the copolymer component, wherein the second ratio of the monomer component to the copolymer component is different than the first ratio.
2 . The method of claim 1 , wherein the contacting step (a) (iii) comprises maintaining the acidic solution at a temperature of from 130 to 185° F.
3 . The method of claim 1 , wherein the contacting step (a) (iii) comprises maintaining the acidic solution at a temperature of at least 165° F.
4 . The method of claim 1 , wherein the drying step (c) is performed in the absence of rinsing after the roll coating step (b).
5 . The method of claim 1 , wherein the alkaline cleaning solution of step (a) (i) is maintained at a temperature of from 125° F. to 175° F.
6 . The method of claim 1 , wherein the alkaline cleaning solution of step (a) (i) comprises potassium hydroxide.
7 . The method of claim 1 , wherein the contacting step (a) (i) is completed without etching of the aluminum alloy product.
8 . The method of claim 7 , wherein the contacting step (a) (i) duration is from 1 second to 4 minutes.
9 . The method of claim 1 , wherein the aluminum alloy product is a 5xxx, 6xxx, or 7xxx aluminum alloy product.
10 . The method of claim 9 , wherein the aluminum alloy product is a 5xxx aluminum alloy product.
11 . The method of claim 10 , wherein the 5xxx aluminum alloy product is a 5754 aluminum alloy product.
12 . The method of claim 9 , wherein the aluminum alloy product is a 6xxx aluminum alloy product.
13 . The method of claim 12 , wherein the 6xxx aluminum alloy product is a 6111 aluminum alloy product.
14 . The method of claim 12 , wherein the 6xxx aluminum alloy product is a 6022 aluminum alloy product.