Security thread, a film and a method of manufacture of a security thread
First Claim
1. A method for manufacturing a security thread for use in security articles including security paper, said security thread comprising a polymeric substrate supporting a pattern of magnetic metal that provides a visually discernable security feature and a magnetically detectable security feature, said method comprising the steps of:
- (a) providing a continuous polymeric web substrate,(b) applying a catalytic material comprising palladium on a surface of said web substrate in a manner that defines said pattern,(c) passing said web substrate with said pattern of catalytic material thereon through a solution containing magnetic metal comprising cobalt or cobalt alloy such that said magnetic metal will be electrolessly deposited on portions of the web substrate provided with said catalytic material so as to appear in said pattern,(d) applying a transparent protective layer over said pattern of magnetic metal, and(e) cutting said web substrate to provide said security thread.
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Accused Products
Abstract
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 μm. 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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Citations
23 Claims
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1. A method for manufacturing a security thread for use in security articles including security paper, said security thread comprising a polymeric substrate supporting a pattern of magnetic metal that provides a visually discernable security feature and a magnetically detectable security feature, said method comprising the steps of:
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(a) providing a continuous polymeric web substrate, (b) applying a catalytic material comprising palladium on a surface of said web substrate in a manner that defines said pattern, (c) passing said web substrate with said pattern of catalytic material thereon through a solution containing magnetic metal comprising cobalt or cobalt alloy such that said magnetic metal will be electrolessly deposited on portions of the web substrate provided with said catalytic material so as to appear in said pattern, (d) applying a transparent protective layer over said pattern of magnetic metal, and (e) cutting said web substrate to provide said security thread. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method for manufacturing a security thread for use in security articles including security paper, said security thread comprising a polymeric substrate supporting a pattern of magnetic metal that provides a visually discernable security feature and a magnetically detectable security feature, said method comprising the steps of:
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(a) providing a continuous polymeric web substrate, (b) applying a layer of catalytic material comprising palladium on a surface of said web substrate, (c) applying blocking means to said layer of catalytic material to define said pattern, (d) passing said web substrate with said pattern of catalytic material thereon through a solution containing magnetic metal comprising cobalt or cobalt alloy such that said magnetic metal will be electrolessly deposited on portions of the web substrate provided with said catalytic material so as to appear in said pattern, (e) applying a transparent protective layer over said pattern of magnetic metal, and (f) cutting said web substrate to provide said security thread. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23)
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Specification