| (19) |
 |
|
(11) |
EP 0 056 675 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
04.08.1982 Bulletin 1982/31 |
| (43) |
Date of publication A2: |
|
28.07.1982 Bulletin 1982/30 |
| (22) |
Date of filing: 19.01.1982 |
|
|
| (84) |
Designated Contracting States: |
|
AT BE DE FR GB IT NL SE |
| (30) |
Priority: |
19.01.1981 JP 702881
|
| (71) |
Applicant: Nippon Paint Co., Ltd. |
|
() |
|
| (72) |
Inventors: |
|
- Nakatani, Nobuo
()
- Tsuzuki, Tooru
()
- Shimizu, Hideo
()
|
|
| |
|
| (54) |
Pretreatment composition for phosphatising ferrous metals, and method of preparing
the same |
(57) An aqueous composition for the treatment of ferrous metal surfaces is a solution
comprising:
(a) titanium compound in amount from 1 to 100 parts per million by weight, measured
as titanium;
(b) phosphate and/or acid phosphate in amount totalling from 50 to 1500 parts per
million by weight, measured as PO4;
(c) pyrophosphate in amount from 10 to 300 parts per million by weight, measured as
P2O7; and
(d) carbonate and/or acid carbonate in amount totalling 20 to 1500 parts per million
by weight, measured as C03;
the solution having a pH from 8.5 to 9.5.