PAPER WITH SECRET INCLUDING DYED FIBRES WITH SECRET HAVING CHANGES OF COLORIMETRIC CHARACTERISTIC DEPENDENT ON WAVE LENGTH AND METHOD OF ITS PRODUCTION Russian patent published in 2010 - IPC D21H15/00 

FIELD: textile, paper.

SUBSTANCE: paper with a secret and method of its production are intended for production of, for instance secured papers with agents that facilitate authentication or preventing counterfeit detected by radiation. Paper with a secret contains multiple dyed fibres with a secret, having wave length that depends on their colour. Fibres with a secret include fluorescent balls formed from the first fluorescent substance. On outer surface of multiple dyed fibres with a secret, there is a dyed layer from a different fluorescent substance. The first fluorescent substance is infrared fluorescent material, and the second one is ultraviolet fluorescent material. Fluorescent balls are excited and radiate light at any one wave length selected from group containing visible wave lengths, infrared wave lengths and ultraviolet wave lengths. Dyed layer radiates light at any one wave length selected from above specified group of wave lengths. Method for production of paper with a secret includes the following stages. Mixing of synthetic resin to produce fibres with a secret and fluorescent balls formed from the first fluorescent substance. Thus produced mix is spun to make fibre with a secret, i.e. fibre containing fluorescent balls. Then fibres with a secret are cut to specified length, thus forming multiple cut fibres with a secret. Dyeing whole outer surface of multiple cut fibres with a secret by the second fluorescent substance, to make dyed fibres with a secret. Introduction of dyed fibres with a secret into pulp and paper solution to make paper with a secret.

EFFECT: improved reliability of working properties of paper with a secret by prevention of counterfeit and improvement of secret effect without occurrence of structural or technological problems.

7 cl, 4 dwg