US4460439A
Expired / Lapsed
US
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Coating process
Assignee: Imperial Chemical Industries Ltd
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Filing: 1983-10-31
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Granted: 1984-07-17
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Expires: 2003-10-31
Abstract
Abstract A conductive substrate as cathode is coated by electrodeposition using a coating material which comprises a sterically stabilized dispersion of film-forming polymer particles in an aqueous medium, the polymer comprising or being associated with a stabilizing polymeric non-ionic hydrophilic moiety which is solvated by the aqueous medium and being free from stabilizing ionic charges. The dispersion of film-forming polymer particles has a critical coalescence value which is more negative than -0.3 units.
Inventors
- 👤 Alan R. Barlow
- 👤 Andrew Doroszkowski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:08
CPC Classifications
C; C09; C09D; C09D5/00; C09D5/44; C09D5/4419; C09D5/443; C09D5/4457; C09D5/4434; C09D5/4488; C09D5/4492; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
152 words
A process for coating a conductive substrate wherein the substrate is immersed in a coating composition comprising an aqueous medium and a dispersed coating material, the substrate is made a cathode in an electric circuit, and an electric current is passed between the cathode and a counter-electrode until a desired amount of coating material is deposited on the substrate, characterised in that: (a) the coating material comprises a film-forming polymer which is sterically stabilised as a dispersion of particles in the aqueous medium and is free from stabilising ionic charges. (b) the film-forming polymer comprises, or is associated with, a polymeric non-ionic hydrophilic moiety which is solvated by the aqueous medium and which contributes to the steric stabilisation of the film-forming polymer particles in the aqueous medium; and (c) the dispersion of film-forming polymer particles in the aqueous medium has a `critical coalescence value (ccv)` which is more negative than -0.3 units.
Claim 2
Dependent Claim
152 words
A process for coating a conductive substrate wherein the substrate is immersed in a coating composition comprising an aqueous medium and a dispersed coating material, the substrate is made a cathode in an electric circuit, and an electric current is passed between the cathode and a counter-electrode until a desired amount of coating material is deposited on the substrate, characterised in that: (a) the coating material comprises a film-forming polymer which is sterically stabilised as a dispersion of particles in the aqueous medium and is free from stabilising ionic charges. (b) the film-forming polymer comprises, or is associated with, a polymeric non-ionic hydrophilic moiety which is solvated by the aqueous medium and which contributes to the steric stabilisation of the film-forming polymer particles in the aqueous medium; and (c) the dispersion of film-forming polymer particles in the aqueous medium has a `critical coalescence value (ccv)` which is more negative than -0.3 units.
Claim 3
Dependent Claim
28 words
A process according to claim 1 wherein the polymeric non-ionic hydrophilic moiety solvated by the aqueous medium is derived from a water-soluble polymer which comprises repeating oxyethylene units.
Claim 4
Dependent Claim
28 words
A process according to claim 2 wherein the polymeric non-ionic hydrophilic moiety solvated by the aqueous medium is derived from a poly(ethylene glycol) or a monoalkyl ether thereof.
Claim 5
Dependent Claim
14 words
A process according to claim 1, wherein the film-forming polymer is an epoxy resin.
Claim 6
Dependent Claim
48 words
A process according to claim 1, wherein the electrophoretic mobility of the particles of film-forming polymer is not greater than 2 μ/s/V/cm when measured at very high dilution in 10 -3 M potassium chloride at 25° C. and at the pH to be employed in the coating process.
Claim 7
Dependent Claim
41 words
A process according to claim 1, wherein the electrical conductivity of the aqueous medium is less than 250 microSiemens/cm at 25° C. when the disperse phase of film-forming polymer particles constitutes 10% by weight of the total weight of the dispersion.
Claim 8
Dependent Claim
116 words
A coating composition suitable for use in the process of claim 1 which comprises an aqueous medium and a dispersed coating material characterised in that: (a) the coating material comprises a film-forming polymer which is sterically stabilised as a dispersion of particles in the aqueous medium and is substantially free from stabilising ionic charges; (b) the film-forming polymer comprises, or is associated with, a polymeric non-ionic hydrophilic moiety which is solvated by the aqueous medium and which contributes to the steric stabilisation of the film-forming polymer particles in the aqueous medium; and (c) the dispersion of film-forming polymer particles in the aqueous medium has a `critical coalescence value (ccv)` which is more negative than -0.3 units.
Claim 9
Dependent Claim
13 words
A coated substrate which has been coated by the process of claim 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) | 1987-07-17 | 1988-01-16 | 1988-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-17 | 1992-01-16 | 1992-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-17 | 1996-01-16 | 1996-07-17 | $7700.00 | Window Closed / Lapsed |