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US4174980A Expired / Lapsed US ⏱️ 0.0 years remaining

Melamine-formaldehyde and tannin treatment of metal surfaces

Assignee: Henkel Corp
•
Filing: 1978-07-24
•
Granted: 1979-11-20
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Expires: 1998-07-24
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Abstract

Abstract Disclosed is a single-application non-electrolytic method for the treatment of bare metal surfaces to form a corrosion-resistant coating. The clean metal surfaces are treated with an aqueous composition containing a melamine-formaldehyde resin and a vegetable tannin. The resulting dried coating exhibits superior qualities for a single-application coating process when used as a paint base and the process does not require the use of environmentally objectionable chromium compounds. Application to ferrous, zinc or aluminum surfaces may be by any known technique designed to provide a deposited layer of desired uniformity.

Inventors

  • 👤 John K. Howell, Jr.
  • 👤 Leonard Kulick

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 22:53
CPC Classifications
B; B05; B05D; B05D7/00; B05D7/14; B05D7/16; C; C09; C09D; C09D5/00; C09D5/08; C23; C23C; C23C22/00; C23C22/05; C23C22/68

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 86 words
A process for treating a bare aluminum surface to impart improved corrosion resistance and adhesion of subsequently-applied paint comprising contacting the surface with a chromium-free aqueous composition exhibiting a pH value of from 8 to 11 and containing at least 0.01 g/l of a melamine-formaldehyde resin and at least 0.01 g/l of a vegetable tannin in a weight ratio of resin:tannin of 1:30 to 30:1 and thereafter drying the composition on the surface to yield a coating weight, of from 1 to 400 mg/ft 2 .
Claim 2
Dependent Claim 86 words
A process for treating a bare aluminum surface to impart improved corrosion resistance and adhesion of subsequently-applied paint comprising contacting the surface with a chromium-free aqueous composition exhibiting a pH value of from 8 to 11 and containing at least 0.01 g/l of a melamine-formaldehyde resin and at least 0.01 g/l of a vegetable tannin in a weight ratio of resin:tannin of 1:30 to 30:1 and thereafter drying the composition on the surface to yield a coating weight, of from 1 to 400 mg/ft 2 .
Claim 3
Dependent Claim 14 words
The process of claim 1, wherein the surface is subsequently dried at elevated temperature.
Claim 4
Dependent Claim 21 words
The process of claim 1, wherein the composition additionally contains a conductive component selected from pulverulent metals and conductive carbon compounds.
Claim 5
Dependent Claim 86 words
A process for treating a bare iron surface to impart improved corrosion resistance and adhesion of subsequently applied paint comprising contacting the surface with a chromium-free aqueous composition exhibiting a pH value of from 1 to 4 and containing at least 0.01 g/l of melamine-formaldehyde resin and at least 0.01 g/l of a vegetable tannin in a weight ratio of resin:tannin of 1:30 to 30:1 and therefore drying the composition on the surface to yield a coating weight of from 1 to 400 mg/ft 2 .
Claim 6
Dependent Claim 86 words
A process for treating a bare iron surface to impart improved corrosion resistance and adhesion of subsequently applied paint comprising contacting the surface with a chromium-free aqueous composition exhibiting a pH value of from 1 to 4 and containing at least 0.01 g/l of melamine-formaldehyde resin and at least 0.01 g/l of a vegetable tannin in a weight ratio of resin:tannin of 1:30 to 30:1 and therefore drying the composition on the surface to yield a coating weight of from 1 to 400 mg/ft 2 .
Claim 7
Dependent Claim 14 words
The process of claim 4 wherein the surface is subsequently dried at elevated temperature.
Claim 8
Dependent Claim 21 words
The process of claim 4 wherein the composition additionally contains a conductive component selected from pulverulent metals and conductive carbon compounds.

References Cited (Backward Citations)

US2383589A Cited
US2854368A Cited
DE1192487B Cited
US3397077A Cited
US3671331A Cited
US3877998A Cited
US4017334A Cited
US4039353A Cited
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US4111722A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1982-11-19 1983-05-21 1983-11-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1986-11-19 1987-05-21 1987-11-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1990-11-19 1991-05-21 1991-11-20 $7700.00 Window Closed / Lapsed

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