Flaky Optical Pigment, Preparation Method thereof and Anti-Counterfeiting Element
AssigneesZhongchao Special Security Technology Co., Ltd, China Banknote Printing and Minting Corp.
InventorKai Sun
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Abstract
The disclosure provides a flaky optical pigment, a preparation method thereof and an anti-counterfeiting element. Wherein at least part of area of the flaky optical pigment includes a subwavelength structure covered with at least one metal layer and at least one dielectric support layer, and the at least one metal layer and the at least one dielectric support layer are alternately stacked up and down, so that the flaky optical pigment produces different colors in a reflection direction and a transmission direction. The flaky optical pigment has a plurality of color features, such as reflection and transmission, is an optical anti-counterfeiting pigment with an attractive visual appearance, and has a low manufacturing cost.
Claims20
A flaky optical pigment, wherein at least part of area of the flaky optical pigment comprises a subwavelength structure covered with at least one metal layer and at least one dielectric support layer, and the at least one metal layer and the at least one dielectric support layer are alternately stacked up and down, so that the flaky optical pigment produces different colors in a reflection direction and a transmission direction.
The flaky optical pigment according to claim 1 or 11, wherein a characteristic size of the subwavelength structure is less than 0.6 μm.
The flaky optical pigment according to claim 1 or 11, wherein the wavelength structure forms a character feature on the flaky optical pigment.
A preparation method of a flaky optical pigment, comprising:
- preparing a subwavelength structure on a first surface of a substrate;
- coating or vacuum evaporating a peeled layer on a surface of the subwavelength structure;
- vacuum evaporating at least one dielectric support layer and at least one metal layer on the surface of the subwavelength structure, and the at least one metal layer and the at least one dielectric support layer are alternately stacked up and down;
- and
- dissolving the peeled layer to obtain the flaky optical pigment.
Dependencies are inferred from the claim text.