| (19) |
 |
|
(11) |
EP 0 097 220 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
22.05.1985 Bulletin 1985/21 |
| (43) |
Date of publication A2: |
|
04.01.1984 Bulletin 1984/01 |
| (22) |
Date of filing: 23.02.1983 |
|
|
| (84) |
Designated Contracting States: |
|
DE FR GB |
| (30) |
Priority: |
18.06.1982 US 389833
|
| (71) |
Applicant: International Business Machines Corporation |
|
() |
|
| (72) |
Inventors: |
|
- Gendler, Paul Lewis
()
- Jaffe, Annette Bronkesh
()
- Twieg, Robert James
()
- Bernier, William Emmett
()
|
|
| |
|
| (54) |
The stabilization of leucomethylene blue dyes on a printing substrate |
(57) Substrates for printing are provided by stabilizing the leucomethylene blue dye contained
therein with an additive selected from the group consisting of citric acid, aspartic
acid, malonic acid, oxalic acid, ascorbic acid, tartaric acid, ketomalonic acid monohydrate,
glucose and methionine.