EP 0029714 A1 19810603 - Method of preventing erasure of an image and a booklet of security papers.
Title (en)
Method of preventing erasure of an image and a booklet of security papers.
Title (de)
Verfahren zum Verhüten des Abkratzens eines Bildes und ein Heft mit Sicherheitspapier.
Title (fr)
Procédé pour prévenir les dommages par grattage d'une image et un carnet de papiers de sécurité.
Publication
Application
Priority
GB 7940210 A 19791121
Abstract (en)
A method of preventing erasure of an image produced from an erasable ballpoint pen or a correctable typewriter by writing or typing the image upon a surface coated with an adsorbent inorganic material, such as a montmorillonite acid clay. Such a method prevents fraudulent alteration of security papers.
IPC 1-7
IPC 8 full level
B44F 1/12 (2006.01); D21H 17/00 (2006.01); D21H 21/46 (2006.01)
CPC (source: EP)
D21H 17/00 (2013.01); D21H 21/46 (2013.01)
Citation (search report)
- US 2333979 A 19431109 - BRADT REXFORD H
- BE 523251 A
- US 2641557 A 19530609 - GREEN BARRETT K
- GB 760080 A 19561031 - NCR CO
- DE 2036892 A1 19720203
- US 2213643 A 19400903 - ALTON WILLIAM H
Designated contracting state (EPC)
DE FR GB IT
DOCDB simple family (publication)
DOCDB simple family (application)
EP 80304166 A 19801120; GB 8000200 W 19801120