US3971708A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrocoating process
Assignee: SCM Corp
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Filing: 1971-07-08
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Granted: 1976-07-27
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Expires: 1991-07-08
Abstract
Abstract Advantageously controlled paint film flow during curing of the film at elevated temperature for avoidance of inadequately coated areas is obtained in an electrocoating operation of an electrode workpiece employing as paint vehicle a mixture of electrodepositable resin and water-dispersible aminoplast or phenoplast resin crosslinkable therewith by incorporating into said vehicle, or into the bath containing same, a small proportion of curing accelerator acid such as a sulfonic acid which is codepositable with said paint film in concentration sufficient for yielding a substantially continuous cured film on the resulting coated substrate. The degree of cure of the deposited coating is monitored by monitoring a property of cured coating which is a function of the degree of cure, and the concentration of the curing accelerator in the bath is adjusted in response thereto to maintain the monitored property at a predetermined value.
Inventors
- 👤 Gerald G. Davis
- 👤 Joan M. Keough
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:11
CPC Classifications
C; C09; C09D; C09D5/00; C09D5/44; C09D5/448; C09D5/4419; C09D5/4469
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
186 words
In a continuous process for coating continuous electrode stock by electrodeposition of a paint film thereon from an aqueous bath containing a dispersion of cationic or anionic resinous vehicle, a dispersant for said resinous vehicle and a water-dispersible resin which is crosslinkable with said resinous vehicle upon curing, said water-dispersible resin being an aminoplast or phenoplast resin, wherein wet coated electrode stock is withdrawn continuously from said bath and force cured to make finished coated stock, the improvement for regulating flow of the freshly electrodeposited film before and during said force curing and thereby continuously producing finished coated stock virtually free from defects related to said flow which comprises: establishing in said bath a dispersion of curing accelerator acid codepositable with said resinous vehicle, the pKa of said acid being not substantially above about 1 and the proportion of said acid being about that for yielding a substantially continuous cured film; monitoring completeness of the resulting coating on the finished coated stock; and, in response to said monitoring, adjusting concentration of said acid in said bath adequately for maintaining substantially completely coated finished coated stock output.
Claim 2
Dependent Claim
186 words
In a continuous process for coating continuous electrode stock by electrodeposition of a paint film thereon from an aqueous bath containing a dispersion of cationic or anionic resinous vehicle, a dispersant for said resinous vehicle and a water-dispersible resin which is crosslinkable with said resinous vehicle upon curing, said water-dispersible resin being an aminoplast or phenoplast resin, wherein wet coated electrode stock is withdrawn continuously from said bath and force cured to make finished coated stock, the improvement for regulating flow of the freshly electrodeposited film before and during said force curing and thereby continuously producing finished coated stock virtually free from defects related to said flow which comprises: establishing in said bath a dispersion of curing accelerator acid codepositable with said resinous vehicle, the pKa of said acid being not substantially above about 1 and the proportion of said acid being about that for yielding a substantially continuous cured film; monitoring completeness of the resulting coating on the finished coated stock; and, in response to said monitoring, adjusting concentration of said acid in said bath adequately for maintaining substantially completely coated finished coated stock output.
Claim 3
Dependent Claim
25 words
The process of claim 1 wherein said electrode stock is the anode, said resinous vehicle is an anodic resin and said dispersant is a base.
Claim 4
Dependent Claim
25 words
The process of claim 1 wherein said electrode stock is the cathode, said resinous vehicle is a cathodic resin and said dispersant is an acid.
Claim 5
Dependent Claim
14 words
The process of claim 1 wherein said curing accelerator acid is a sulfonic acid.
Claim 6
Dependent Claim
52 words
The process of claim 1 wherein the cured paint film is monitored for completeness of coverage by monitoring dielectric strength and the proportion of said curing accelerator acid in said bath is established and maintained to sustain the monitored dielectric strength above about 500 volts per mil of cured paint film thickness.
Claim 7
Dependent Claim
34 words
The process of claim 1 wherein said curing accelerator acid is maintained in a concentration in said bath between about 0.01 and about 1 meq. of acid per gram of total resin solids present.
Claim 8
Dependent Claim
23 words
The process of claim 1 wherein the curing accelerator acid is rendered substantially homogeneous in the coating film by use of a solvent.
Claim 9
Dependent Claim
19 words
The process of claim 1 wherein said aqueous bath is replenished by paint concentrate containing said curing accelerator acid.
Claim 10
Dependent Claim
30 words
The process of claim 1 wherein said cationic or anionic resinous vehicle contains about 1 to 30% by weight of carboxyl groups, alcoholic hydroxyl groups, amide groups and mixtures thereof.
Claim 11
Dependent Claim
27 words
The process of claim 1 wherein said aminoplast resin is a water-dispersible condensation reaction product of an aldehyde with urea, melamine, aniline, ammidine, guanidine, dicyandiamide or benzoguanamine.
Claim 12
Dependent Claim
23 words
The process of claim 1 wherein said phenoplast resin is a water-dispersible condensation product of an aldehyde with a phenol or substituted phenol.
Claim 13
Dependent Claim
27 words
The process of claim 1 wherein the weight proportion of cationic or anionic resinous vehicle to aminoplast or phenoplast resin is between about 9:1 and about 2:1.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-07-27 | 1980-01-26 | 1980-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-27 | 1984-01-26 | 1984-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-27 | 1988-01-26 | 1988-07-27 | $7700.00 | Window Closed / Lapsed |