| (19) |
 |
|
(11) |
EP 1 336 669 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
30.06.2004 Bulletin 2004/27 |
| (43) |
Date of publication A2: |
|
20.08.2003 Bulletin 2003/34 |
| (22) |
Date of filing: 04.02.2003 |
|
|
| (84) |
Designated Contracting States: |
|
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT SE SI SK TR |
|
Designated Extension States: |
|
AL LT LV MK RO |
| (30) |
Priority: |
15.02.2002 IT MI20020307
|
| (71) |
Applicant: FABBRICA D'ARMI PIETRO BERETTA S.p.A. |
|
25122 Brescia (IT) |
|
| (72) |
Inventor: |
|
- Gussalli Beretta, Ugo
25063 Gardone Val Trompia (Brescia) (IT)
|
| (74) |
Representative: Coppo, Alessandro |
|
Ing. Barzanò & Zanardo Milano S.p.A., Via Borgonuovo, 10
20121 Milano
20121 Milano (IT) |
|
| |
|
| (54) |
Process for providing a tortoise-shell chromatic effect to metallic substrates |
(57) The present invention relates to a chemical process for providing a tortoise-shell
chromatic effect to nickelated metallic substrates, which comprises heating the metallic
substrate to 100-110°C and subsequent buffering at a temperature of 40-110°C with
an oxidizing solution based on sodium thiosulfate, a reagent metal and an acidifying
compound.