Rinsing coated metallic surfaces

Claim 3

A method according to claim 1 wherein said rinse solution contains also formaldehyde-reduced forms of Cr.sup. +6 .

Claim 4

A method according to claim 1 wherein said resinous coating has a glossy surface and wherein said hexavalent chromium is present in said rinse solution in an amount at least sufficient to reduce the gloss of said surface.

Claim 5

A method according to claim 3 wherein said rinse solution contains also formaldehyde-reduced forms of Cr.sup. +6 .

Claim 8

A method according to claim 5 wherein said rinse solution contains also formaldehyde-reduced forms of Cr.sup. +6 .

Claim 9

A method according to claim 5 wherein said resinous coated surface has a glossy appearance and wherein said hexavalent chromium is present in said rinse solution in an amount at least sufficient to reduce the gloss of said surface.

Claim 10

A method according to claim 7 wherein said rinse solution contains also formaldehyde-reduced forms of Cr.sup. +6 .

Claim 11

A method according to claim 8 wherein the molar ratio of hexavalent chromium/reduced chromium in the rinse solution is within the range of about 0.6 to about 20 and wherein the total chromium concentration in the rinse solution is at least about 4 g/l.

Claim 12

A method according to claim 8, wherein the molar ratio of hexavalent chromium/reduced chromium in the rinse solution is about 1 and wherein the total chromium concentration in the rinse solution is at least about 0.5 g/l.

Claim 13

A process for applying a coating to a metallic surface comprising: a. immersing a metallic surface in an aqueous acidic organic coating composition comprising, in coating-forming proportions, water, hydrogen ion, an oxidizing agent which contains oxygen, and an organic coating material selected from the group consisting of water-soluble, water-dispersible and water-emulsifiable film-forming polymeric resinous materials; b. depositing said resinous material on said surface to form thereon a resinous coating while said surface is immersed in said composition; c. maintaining said surface in said composition and depositing thereon additional resinous material to thereby produce a resinous coating, the thickness of of which increases during at least a portion of the time said surface is immersed in said composition; and d. withdrawing the resinous-coated surface from said composition after the desired amount of resinous coating has been deposited on said surface; wherein said composition will produce said coating on said metallic surface in the absence of any electrical charge on said metallic surface other than that imparted thereto by said composition; and wherein said composition is sufficiently acidic to effect an increase in the amount of resinous coating deposited within at least about 10 minutes from the time said metallic surface is immersed in said composition; and wherein said resinous coating is initially adherent and resists being removed from said surface when it is rinsed after it is withdrawn from said composition; and e. thereafter treating the resinous coated surface with an aqueous rinse solution containing chromium in an amount at least sufficient to improve the corrosion resistant properties of said coating.

Claim 14

A process for applying a coating to a metallic surface comprising: a. immersing a metallic surface in an aqueous acidic organic coating composition comprising, in coating-forming proportions, water, hydrogen ion, an oxidizing agent which contains oxygen, and an organic coating material selected from the group consisting of water-soluble, water-dispersible and water-emulsifiable film-forming polymeric resinous materials; b. depositing said resinous material on said surface to form thereon a resinous coating while said surface is immersed in said composition; c. maintaining said surface in said composition and depositing thereon additional resinous material to thereby produce a resinous coating, the thickness of of which increases during at least a portion of the time said surface is immersed in said composition; and d. withdrawing the resinous-coated surface from said composition after the desired amount of resinous coating has been deposited on said surface; wherein said composition will produce said coating on said metallic surface in the absence of any electrical charge on said metallic surface other than that imparted thereto by said composition; and wherein said composition is sufficiently acidic to effect an increase in the amount of resinous coating deposited within at least about 10 minutes from the time said metallic surface is immersed in said composition; and wherein said resinous coating is initially adherent and resists being removed from said surface when it is rinsed after it is withdrawn from said composition; and e. thereafter treating the resinous coated surface with an aqueous rinse solution containing chromium in an amount at least sufficient to improve the corrosion resistant properties of said coating.

Claim 15

A method according to claim 11 wherein said rinse solution contains hexavalent chromium.

Claim 16

A method according to claim 12 wherein said rinse solution contains also formaldehyde-reduced forms of Cr.sup. +6 .

Claim 17

A method according to claim 13 wherein said rinse solution includes polyacrylic acid.

Claim 18

A method according to claim 14 wherein the concentration of said polyacrylic acid is about 2.5 g/l to about 50 g/l.

Claim 19

A method according to claim 11 wherein the concentration of said chromium in said rinse solution is at least about 0.1 g/l.

Claim 20

A method according to claim 11 wherein the concentration of said chromium in said rinse solution is at least about 0.25 g/l.

Claim 21

A method according to claim 11 wherein said resinous coating has a glossy surface and wherein said chromium is present in said rinse solution in an amount at least sufficient to reduce the gloss of said surface.

Claim 22

A method according to claim 18 wherein said rinse solution contains hexavalent chromium.

Claim 23

A method according to claim 19 wherein said rinse solution contains also formaldehyde-reduced forms of Cr + 6 .

Claim 24

A method according to claim 20 wherein the molar ratio of hexavalent/reduced chromium in the rinse solution is within the range of about 0.6 to about 20 and wherein the total chromium concentration in the rinse solution is at leat about 4 g/l.

Claim 25

A method according to claim 20 wherein the molar ratio of hexavalent/reduced chromium in the rinse solution is about 1 and wherein the total chromium concentration in the rinse solution is at least about 0.5 g/l.

Claim 26

A method according to claim 19 wherein the concentration of hexavalent chromium is at least about 3 g/l.

Claim 27

A method according to claim 11 wherein said coating composition comprises fluoride ion, an oxidizing agent selected from the class consisting of hydrogen peroxide and dichromate, and particles of resin dispersed in the composition.

Claim 28

A method according to claim 24 wherein said rinse solution contains hexavalent chromium.

Claim 29

A method according to claim 25 wherein said rinse solution contains also formaldehyde-reduced forms of Cr - 6 .

Claim 30

A method according to claim 26 wherein said rinse solution includes polyacrylic acid.

Claim 31

A method according to claim 26 wherein the concentration of said polyacrylic acid is about 2.5 g/l to about 50 g/l.

Claim 32

A method according to claim 24 wherein the concentration of said chromium in said rinse solution is at least about 0.1 g/l.

Claim 33

A method according to claim 24 wherein the concentration of said chromium in said rinse solution is at least about 0.25 g/l.

Claim 34

A method according to claim 24 wherein said resinous coating has a glossy surface and wherein said chromium is present in said rinse solution in an amount at least sufficient to reduce the gloss of said surface.

Claim 35

A method according to claim 31 wherein said rinse solution contains hexavalent chromium.

Claim 36

A method according to claim 32 wherein said rinse solution contains also formaldehyde-reduced forms of Cr + 6 .

Claim 37

A method according to claim 33 wherein the molar ratio of hexavalent/reduced chromium in the rinse solution is within the range of about 0.6 to about 20 and wherein the total chromium concentration in the rinse solution is at least about 4 g/l.

Claim 38

A method according to claim 33 wherein the molar ratio of hexavalent/reduced chromium in the rinse solution is about 1 and wherein the total chromium concentration in the rinse solution is at least about 0.5 g/l.

Claim 39

A method according to claim 32 wherein the concentration of hexavalent chromium is at least about 3 g/l.

Claim 40

An improvement in the process of coating metallic articles by acidic deposition which comprises: contacting an unbaked or uncured acidic deposited coating of a synthetic film-forming resin on a metallic article with a solution comprising a material selected from the group consisting of chromium trioxide, and water or acid soluble chromates and dichromates, wherein said material is present in said solution in an amount at least sufficient to improve the corrosion resistant properties of said coating.

Claim 41

An improvement in the process of coating metallic articles by acidic deposition which comprises: contacting an unbaked or uncured acidic deposited coating of a synthetic film-forming resin on a metallic article with a solution comprising a material selected from the group consisting of chromium trioxide, and water or acid soluble chromates and dichromates, wherein said material is present in said solution in an amount at least sufficient to improve the corrosion resistant properties of said coating.

Claim 42

The process of claim 37 wherein said solution includes phosphoric acid, wherein the concentration of phosphoric acid is such that for each gram of total Cr present in the solution, the amount of phosphoric acid present is equal to or greater than the amount of phosphoric acid present in 0.05 ml of 75% phosphoric acid.

Claim 43

The process of claim 37 wherein said solution is aqueous.

Claim 44

The process of claim 37 wherein said material is selected from the group consisting of chromium trioxide and an acid soluble chromate.

Claim 45

The process of claim 37 wherein said solution comprises at least about 0.1 g/l of Cr added as chromium trioxide.

Claim 46

The process of claim 37 wherein said solution comprises at least about 0.25 g/l of Cr added as an acid soluble dichromate.

Claim 47

The process of claim 37 wherein said material is present in an amount such that the Cr concentration is about 0.25 g/l to about 10 g/l.

Claim 48

The coated article obtained by the process of claim 37.

Claim 49

An improvement in the process of coating metallic articles by acidic deposition which comprises: contacting an unbaked or uncured acidic deposited coating of a synthetic film-forming resin on a metallic article with a solution comprising a material selected from the group consisting of chromium trioxide, and water or acid soluble chromates and dichromates; and baking said article for a time sufficient to cure the coating thereon; wherein said material is present in said solution in an amount at least sufficient to improve the corrosion resistant properties of said coating.

Claim 50

An improvement in the process of coating metallic articles by acidic deposition which comprises: contacting an unbaked or uncured acidic deposited coating of a synthetic film-forming resin on a metallic article with a solution comprising a material selected from the group consisting of chromium trioxide, and water or acid soluble chromates and dichromates; and baking said article for a time sufficient to cure the coating thereon; wherein said material is present in said solution in an amount at least sufficient to improve the corrosion resistant properties of said coating.

Claim 51

The coated article obtained by the process of claim 45.