| 摘要 |
<p>The invention relates to a security paper for document protection against counterfeiting and to a process for obtaining the same. According to the invention, the paper comprises 50...70% sulphate of bleached cellulose from resinous trees, 50...30% sulphate of bleached cellulose from deciduous trees, 10% calcium carbonate and 1.5%, as compared with the total amount of material, sizing agent, 0.5% retention agent and 0.025% ferromagnetic microfibres of an alloy containing Fe, Si, B, and Co, Fe, Cr, Mn, Si, B, respectively, with a saturation magnetic induction Bs=0.2...0.7 T and a magnetic permeability of u=100...65000. The process claimed by the invention consists in mixing the components with 0.025% ferromagnetic microfibres, after which the mixture is treated with an oxidated starch solution in a concentration of 6...8% and subjected to a drying thermal condition at a temperature of 70...110°C, wherefrom there results a security paper with magnetic microfibres having 80...89 g/m, a thickness of 0.10...0.12 mm and a humidity of 5%.</p> |
