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You can use Global Patent Index (GPI) to carry out detailed searches in the EPO's worldwide bibliographic (DOCDB), legal event (INPADOC) and full-text data sets, and download or visualise the search results for statistical analysis.

Current content: 156 632 791 patent documents

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121 162 new documents added

981 197 documents amended

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EP 0072481 B1 19861230 - TAMPERPROOF PAPER

Title (en)

TAMPERPROOF PAPER

Publication

EP 0072481 B1 19861230 (DE)

Application

EP 82106954 A 19820802

Priority

DE 3132146 A 19810814

Abstract (en)

[origin: US4478681A] Forgery-proof paper, which exhibits a distinct coloration when treated with an oxidizing agent and, if appropriate, a reducing agent, contains, as the reagent, a compound of the formula <IMAGE> I wherein A represents N or C, B represents NR, O or S, R represents hydrogen or alkyl, X and Y represent hydrogen or customary substituents and n and m represent the numbers 1 or 2.

IPC 1-7

D21H 5/10

IPC 8 full level

B44F 1/12 (2006.01); D21H 19/10 (2006.01); D21H 21/28 (2006.01); D21H 21/40 (2006.01); D21H 21/46 (2006.01)

CPC (source: EP US)

D21H 21/46 (2013.01 - EP US); Y10S 428/916 (2013.01 - EP US)

Designated contracting state (EPC)

CH DE FR GB LI

DOCDB simple family (publication)

EP 0072481 A1 19830223; EP 0072481 B1 19861230; DE 3132146 A1 19830303; DE 3274888 D1 19870205; JP H0149840 B2 19891026; JP S5836298 A 19830303; US 4478681 A 19841023

DOCDB simple family (application)

EP 82106954 A 19820802; DE 3132146 A 19810814; DE 3274888 T 19820802; JP 13806582 A 19820810; US 40083482 A 19820722