| (19) |
 |
|
(11) |
EP 0 786 539 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
20.08.1997 Bulletin 1997/34 |
| (43) |
Date of publication A2: |
|
30.07.1997 Bulletin 1997/31 |
| (22) |
Date of filing: 22.01.1997 |
|
|
| (84) |
Designated Contracting States: |
|
BE DE ES FR GB IT |
| (30) |
Priority: |
26.01.1996 US 592439
|
| (71) |
Applicant: ELF ATOCHEM NORTH AMERICA, INC. |
|
Philadelphia,
Pennsylvania 19103-3222 (US) |
|
| (72) |
Inventors: |
|
- Martyak, Nicholas M.
Doylestown, PA 18901 (US)
- Corsentino, John A.
Hazlet, NJ 07730 (US)
- Rohling, Frederik L.
2023 SM Haarlem (NL)
- Kasper, Marie M.
Redbank, NJ 07701 (US)
|
| (74) |
Representative: Weisert, Annekäte, Dipl.-Ing. Dr.-Ing. et al |
|
Patentanwälte
Kraus Weisert & Partner
Thomas-Wimmer-Ring 15
80539 München
80539 München (DE) |
|
| |
|
| (54) |
High current density zinc organosulfonate electrogalvanizing process and composition |
(57) The inventors disclose a process for reducing high current density edge buildup dendrite
formation, edge burn, controlling high current density roughness, grain size, and
orientation of a zinc coating obtained from an aqueous zinc acidic electrogalvanic
coating bath comprising passing a high density current from a zinc anode in the bath
to a metal cathode in the bath for a period of time sufficient to deposit a zinc coating
on the cathode. The bath contains greater than about 5g/l of a water soluble zinc
organosulfonate. A random or block polyoxyalkylene glycol homopolymer or copolymer
based on 2 to about 4 carbon atom alkylene oxides. The inventors employ current densities
from about 250 to about 4,000 ASF, and optionally, a sulfonated condensation product
of naphthalene and formaldehyde, a boron oxide compound, and a lignin compound. The
invention also comprises bath compositions.