MULTILAYER PROTECTIVE DEVICE AND ITS MANUFACTURING METHOD Russian patent published in 2020 - IPC B42D15/00 

FIELD: means of counterfeit protection of valuable documents.

SUBSTANCE: invention relates to means of counterfeit protection of valuable documents, in particular, to multilayer protective device and method of its manufacturing. Device comprises at least one protective element (9) located between polyethylene terephthalate (PET) carrier film and PET film (7). At that, at least one protective element is made in the form of various visually-visible multi-color images formed on and / or in the transparent surface in the visible spectrum, isotropic, thermoplastic polycarbonate layer (PL) on the side of PET film (7). Each of visually visible image images forming corresponding protective element is provided with corresponding set ξi (x,y) of spatially spaced diffraction gratings, each of which is characterized by different and / or identical for each grid predetermined parameters, comprising: spatial frequency ωi strokes, angular orientation θi strokes in space, depth hi and shape of strokes, partially reflecting layer (5) located above at least one protective element (9), and adhesive layer (6) provided between partially reflecting layer (5) and PET film (7). PET carrier film (1) is configured to be removable when the protective device is applied to the object to be protected.

EFFECT: good interlayer adhesion, mechanical strength, absence of deformation during high-temperature bonding of the relief structure, high heat resistance, reinforcement of the protective element, high wear resistance.

29 cl, 4 dwg