发明名称 |
Security thread, a film and a method of manufacture of a security thread |
摘要 |
The present invention relates in one aspect to a method of manufacture of a security thread suitable for use in security articles including security paper such as that used for banknotes. In the method a magnetic metal is deposited on a film of polymeric substrate as the substrate passes through a solution containing the magnetic metal and a preparatory operation is carried out on a surface of the substrate prior to immersion of the substrate in the solution. The preparatory operation ensures that magnetic metal is deposited on the substrate in a pattern such that when the security thread is produced from the film by cutting the film the magnetic metal on the security thread has a specific pattern and provides both a visually discernible security feature and a magnetically detectable security feature. In a second aspect the present invention provides a security thread for security paper such as banknotes, the security thread comprising a polymeric substrate catalytic material covering at least a portion of one surface at the polymeric substrate and a layer of electrolessly deposited magnetic metal covering at least a portion of the catalytic material with a depth in the range 0.01-3.0 mu m. The layer of magnetic material has a specific pattern and provides the security thread with both a visually discernible security feature and a magnetically detectable security feature, the security thread having an average magnetic remanence in the range 0.001-0.05 emu cm-2.
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申请公布号 |
US5631039(A) |
申请公布日期 |
1997.05.20 |
申请号 |
US19940289440 |
申请日期 |
1994.08.12 |
申请人 |
PORTALS LIMITED |
发明人 |
KNIGHT, MALCOLM R. M.;REID, DUNCAN H.;HARRISON, JEFFREY A. |
分类号 |
B42D15/00;D21H21/42;G07D7/04;(IPC1-7):B41M3/14;B05D5/12 |
主分类号 |
B42D15/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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