CN113913031A

CN113913031A - Safety unit and application thereof

Info

Publication number: CN113913031A
Application number: CN202111243686.3A
Authority: CN
Inventors: 李云虎; 李奂实
Original assignee: Xi'an Shengda Hengxin Optical Technology Co ltd
Current assignee: Xi'an Shengda Hengxin Optical Technology Co ltd
Priority date: 2021-10-25
Filing date: 2021-10-25
Publication date: 2022-01-11
Anticipated expiration: 2041-10-25
Also published as: CN113913031B

Abstract

The invention discloses a safety unit and application thereof, and the safety unit comprises an optical interference structure layer, wherein the outer side of the optical interference structure layer is coated with a continuous bearing layer, functional particles are fused in the continuous bearing layer, and the functional particles comprise one, two or more of fluorescent particles, noctilucent particles, phosphorescent particles, magnetic particles, infrared absorption particles, ultraviolet absorption particles, thermosensitive discoloring particles and pressure-sensitive discoloring particles; a first color when viewed from a first angle and a second color when viewed from a second angle, the first color being different from the second color; the continuous bearing layer can effectively connect the angle-dependent color units and the particles with specific performance into a stable whole, and the prepared pigment can reduce the phenomenon that the consistency of the display effect is deteriorated due to uneven stirring or different material layering formed by material density difference when the pigment is added into carriers such as printing ink, coating and the like for application; the transparent bearing layer can play the role of angle-dependent color variation effect and the effect of functional particles without shielding.

Description

Safety unit and application thereof

Technical Field

The invention belongs to the field of anti-counterfeiting technology and pigment, and particularly relates to a safety unit and application thereof.

Background

In the prior art, angle-dependent color pigments or cholesteric liquid crystal mixtures are often used to produce security pigments.

Optically variable pigments are pigments for security and decorative purposes which are formed by physically or chemically depositing metal and dielectric materials in the form of 3, 5 or 7 thin films of symmetrical interference structures and then by processes of comminution, surface treatment, etc., such structures and effects being described, for example, in patent CN 1211437C. The effect of the angle-dependent heterochrosis pigment is obvious, but the anti-counterfeiting effect is single, so that the pigment is mainly used for decoration, and is mainly used for one-line anti-counterfeiting in the anti-counterfeiting application field, and the anti-counterfeiting function tends to weaken.

The chiral cholesteric liquid crystal mixture is a pigment for anti-counterfeiting and decoration purposes, which is formed by adding fluorescent, magnetic and other particles into a chiral cholesteric liquid crystal material and then carrying out processes of film making, crushing, surface treatment and the like, and the functional material is described in patent CN 101087864A for example. Although the chiral cholesteric liquid crystal mixture is added with a two-line anti-counterfeiting means which can be identified by means of equipment and tools, such as fluorescence, magnetism and the like, due to the limitation of materials of the chiral cholesteric liquid crystal, the effect of the color-dependent color is strong without physical deposition or chemical deposition of metal and a medium material, the consistency is poor, and functional materials, such as fluorescence, magnetism and the like, are completely wrapped in the liquid crystal material with the color, so that the function of the materials, such as fluorescence, phosphorescence, light absorption and the like, is greatly influenced.

It is a good solution to mix the effect pigment and the specific functional pigment directly in the coating or to superpose the above two pigments as separate coatings, as described in patent CN101171099A, the specific functional materials are: the spectral absorption material, the luminescent material and the angle dependent color pigment independently exist in a coating at the same time, so that the process is simple and easy to realize, but the defect is obvious, two materials with different densities do not form a whole, layering is easy to generate during the manufacturing of the coating, especially, special function particles can not generate due effect when most of the angle dependent color pigment is on the upper part, or more special function particles can shield the angle dependent color pigment when most of the angle dependent color pigment is on the upper part, so that the angle dependent color effect can not be well displayed. The patent also provides another implementation mode, the effect pigment and the specific functional material are respectively made into layers and then are superposed, but the effect pigment and the specific functional material are superposed as two independent coatings, the printing and manufacturing process is complex, the cost is high, the more the types of the functional material layers are used, the more the printing times are, and the higher the cost is.

Therefore, it is desirable to provide a novel anti-counterfeit material having a color effect with specific properties, a stable anti-counterfeit effect, and controllable specific properties, so as to solve the above problems.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a safety unit, wherein a flip-flop structural unit and particles with specific properties are connected or fused into a whole safety unit through a bearing layer, and the safety unit has excellent flip-flop and specific property effects. The pigment prepared by the safety unit can be added into ink or other carriers to play a role in anti-counterfeiting.

In order to achieve the purpose, the invention adopts the technical scheme that: a safety unit comprises an optical interference structure layer, wherein a continuous bearing layer is coated on the outer side of the optical interference structure layer, functional particles are fused in the continuous bearing layer, and the functional particles comprise one, two or more of fluorescent particles, luminous particles, phosphorescent particles, magnetic particles, infrared absorption particles, ultraviolet absorption particles, thermosensitive discoloration particles and pressure-sensitive discoloration particles; has a first color when viewed from a first angle and a second color when viewed from a second angle, the first color being different from the second color.

The number of layers of the symmetrical optical interference structure layer is an odd number, and the symmetrical optical interference structure layer is an optical interference structure which is symmetrical about the middle layer.

The optical interference structure layer is a thin-film optical interference structure layer with three, five or seven symmetrical interference structures formed by means of physical deposition or chemical deposition of metal and dielectric materials.

The continuous bearing layer is transparent, and the thickness of the continuous bearing layer is 1 nm-50 mu m.

The material of the continuous bearing layer is oxide, inorganic salt, organic salt, resin or the composition of the above substances.

The continuous bearing layer adopts silicon dioxide, silicate, titanium dioxide, titanate, alumina, aluminate, resin or the combination of the above substances.

The functional particles are completely wrapped by the continuous bearing layer, partially wrapped by the continuous bearing layer, on the surface of the continuous bearing layer, and have two or three states simultaneously.

The functional particles are spherical, flaky or irregular, the particle size range of the functional particles is 1 nm-120 mu m, and the mass of the functional particles accounts for 0.01-70% of the total mass of the safety unit.

Based on the application of the security element of the invention, the security element is manufactured as a pigment and added to ink or a vehicle for spraying, injection molding, printing or labeling for forgery prevention and decoration.

Compared with the prior art, the invention has at least the following beneficial effects:

1. the continuous bearing layer can effectively connect the angle-dependent color units and the particles with specific performance into a stable whole, and the prepared pigment can reduce the phenomenon that the consistency of the display effect is deteriorated due to uneven stirring or different material layering formed by material density difference when the pigment is added into carriers such as printing ink, coating and the like for application;

2. the transparent bearing layer can play the effect of the angle-dependent color variation and the effect of the specific functional particles without shielding, such as: fluorescence, phosphorescence, noctilucence, infrared absorption, ultraviolet absorption, thermochromic, pressure sensitive color change, and the like;

3. the safety unit can design the addition amount of the functional particles according to the preset function, and the addition amount of the functional particles is used for controlling the strength, the shielding efficiency and the uniformity of the special functional effect, so that the anti-counterfeiting effect is more flexible, and the consistency is better.

4. The safety unit can simultaneously have multiple functions, such as color variation along with angles and simultaneous existence of functions of optical absorption, fluorescence, noctilucence, magnetism and the like, has higher safety, and can adjust the adding proportion of different functional materials during the manufacturing of the safety unit, thereby adjusting the strength of different effects.

Drawings

FIG. 1 is a schematic diagram of a security unit of the present invention having a predetermined capability;

fig. 2 shows a security element with two functional particles a and B, wherein a and B are completely surrounded by a carrier layer, partially surrounded by a carrier layer and on the surface of the carrier layer.

Fig. 3 is a schematic illustration of embodiment 1.

1-continuous bearing layer, 2-optical interference structure layer and 3-functional particle.

FIG. 4 is a schematic illustration of embodiment 2

FIG. 5 is a schematic illustration of embodiment 3

Detailed Description

The present invention will be described in detail with reference to the following embodiments.

A transparent continuous bearing layer is wrapped on a 3, 5 or 7-layer symmetrical optical structure unit with an angle dependent color effect formed by physically or chemically depositing metal and a medium material, and single specific performance particles or a combination of multiple specific performance particles are embedded on the surface of or in the bearing layer, so that a firm safety unit whole body is formed. Wherein the effect of flop is provided by the symmetrical optical building blocks and the specific properties are provided by the specific properties particles or their combinations.

Example 1: and the 5 symmetrical optical interference structure layers 2 comprise a first layer of metal titanium, a second layer of silicon dioxide medium, a third layer of metal aluminum, a fourth layer of silicon dioxide medium and a fifth layer of metal titanium, wherein the interference structure layers are red interference colors when observed by human eyes from 0-15 degrees and green interference colors when observed from 60-90 degrees. And a 1-micron silicon dioxide bearing layer 1 is wrapped on the outer surface of the symmetrical optical interference structure layer. Fluorescent particles 3 with the mass fraction accounting for 10-50% of the safety unit and the particle size range of 50-500 nm are embedded in the bearing layer, and the fluorescent particles can emit yellow fluorescent light under the excitation of light with the wavelength of 365 nm. As shown in fig. 3, under natural light conditions, when human eyes observe from 0 to 15 °, natural light irradiates a portion which is not shielded by fluorescent particles, and passes through the silica bearing layer 1, and finally the symmetric optical interference structure layer 2 generates a red interference color, and the red interference color presents a green interference color when observing from 60 to 90 °, when light with a wavelength of 365nm is irradiated, the light with the wavelength of 365nm irradiates on the fluorescent particles 3 to excite bright yellow fluorescence, and human eyes can see the yellow fluorescence at any angle, while light with the wavelength of 365nm irradiates on other portions to generate no interference color and no fluorescence which can be recognized by human eyes, so that the human eyes cannot recognize the light.

As an alternative embodiment, the continuous carrier layer 1 may be silica, silicate, titania, titanate, alumina, aluminate, resin or a combination thereof.

With silica, silicates, titania, titanates, alumina, aluminates, resins, or combinations thereof.

Particularly, the 10-50% of addition proportion can flexibly adjust the relative strength of the effect of changing color along with the angle and the fluorescence effect, and meet the requirements under different scenes; the fluorescent particles can also be partially wrapped by the bearing layer and arranged on the surface of the bearing layer, and the same effect can be generated.

When two or more functions are required, the types of functional particles are increased according to the characteristics of the functions.

The present case only discloses one specific application, and the effect of the flip-flop is various, such as: red to green, green to blue, orange to green, yellow to green, green to red, gold to green, etc., the fluorescent particles can also be made of various materials and present various colors, such as: green, yellow, blue, purple and yellow, and in addition, the wavelength of the excitation light source also has a large bandwidth, but the wavelength does not influence the anti-counterfeiting effect of the color along with the angle and the fluorescence while the protection of the invention is realized.

In addition, the pigment prepared by the safety unit with the effect of angle dependent color change and fluorescence is added into ink or other compositions for injection molding, spraying, printing and preparing into printing or sticking paper, and the same effect can be generated.

When two or more different special functional particles are added, the binding firmness with the carrier layer is different due to the difference in surface properties caused by the difference in material characteristics, surface roughness, particle size and the like. Therefore, the use of the composite support layer composed of silica and sodium silicate can increase the bonding strength with the special functional particles, as in example 2.

Example 2: and the 5 symmetrical optical interference structure layers 2 comprise a first layer of metal titanium, a second layer of silicon dioxide medium, a third layer of metal aluminum, a fourth layer of silicon dioxide medium and a fifth layer of metal titanium, wherein the interference structure layers are green interference colors when observed by human eyes from 0-15 degrees and blue interference colors when observed at 60-90 degrees. The outer surface of the symmetrical optical interference structure layer is coated with a silicon dioxide and sodium silicate bearing layer 1 with the thickness of 0.5-2 mu m, wherein the silicon dioxide accounts for 75-95% of the mass of the bearing layer, and the sodium silicate accounts for 5-25% of the mass of the bearing layer. Fluorescent particles 3 with the mass fraction of 15 percent of the safety unit and the particle size range of 10-200 nm are embedded in the carrier layer, the fluorescent particles can emit yellow green fluorescence under the excitation of light with the wavelength of 365nm, and infrared absorption particles 4 with the mass fraction of 30 percent of the safety unit and the particle size range of 10-50 nm can absorb infrared rays with the wavelength of 850-1250 nm. As shown in fig. 4, under natural light conditions, when human eyes observe from 0 to 15 °, natural light irradiates a portion which is not shielded by fluorescent particles and infrared absorption particles, and passes through a silica bearing layer, and finally a green interference color is generated by the symmetric optical interference structure layer 2, and a blue interference color appears when observing from 60 to 90 °, when light with a wavelength of 365nm is irradiated, the light with the wavelength of 365nm irradiates on the fluorescent particles to excite bright yellow-green fluorescence, and human eyes can see yellow fluorescence at any angle, while light with the wavelength of 365nm irradiates on other portions to generate no interference color and no fluorescence which can be recognized by human eyes, so that the light cannot be recognized by the human eyes. When the reflectivity of the safety unit is detected by a spectrometer, light in an infrared band with the wavelength of 850-1250 is absorbed by the infrared absorption particles, so that an absorption effect of obvious reflectivity reduction is achieved. The safety unit has the three functional characteristics of color variation along with angles, ultraviolet fluorescence excitation and infrared absorption, and the functional particles are good in combination firmness with the bearing layer, and can be widely applied to safety printing affairs such as brand protection, finance and government when being added into ink.

Example 3: the optical interference structure layer 2 comprises 5 symmetrical optical interference structure layers, wherein the first layer is metal titanium, the second layer is a silicon dioxide medium, the third layer is metal aluminum, the fourth layer is a silicon dioxide medium, and the fifth layer is metal titanium, and the interference structure layer is orange interference color when observed by human eyes from 0-15 degrees and green interference color when observed from 60-90 degrees. And a 1-micron silicon dioxide bearing layer 1 is wrapped on the outer surface of the symmetrical optical interference structure layer. The metal nickel particles 3 with the mass fraction accounting for 25-50% of the safety unit and the particle size range of 50-200 nm are embedded in the bearing layer. As shown in fig. 5, under natural light conditions, when human eyes observe from 0 to 15 °, natural light irradiates the portion which is not shielded by nickel particles, and transmits through the silica bearing layer 1, and finally the symmetric optical interference structure layer 2 generates an orange interference color, and the interference color appears green when observed from 60 to 90 °. The safety unit is placed in a magnetic field, and the nickel particles are magnetized under the action of the magnetic field, so that the safety unit has the magnetic property and the optical optically variable color property of the magnetic material.

Claims

1. A safety unit is characterized by comprising an optical interference structure layer (2), wherein the outer side of the optical interference structure layer (2) is coated with a continuous bearing layer (1), functional particles (3) are fused in the continuous bearing layer (1), and the functional particles (3) comprise one, two or more of fluorescent particles, noctilucent particles, phosphorescent particles, magnetic particles, infrared absorbing particles, ultraviolet absorbing particles, thermosensitive discoloring particles and pressure-sensitive discoloring particles; has a first color when viewed from a first angle and a second color when viewed from a second angle, the first color being different from the second color.

2. A security element according to claim 1, characterized in that the number of layers of the symmetric optical interference structure layer (2) is an odd number, the symmetric optical interference structure layer (2) being an optical interference structure which is symmetric with respect to the intermediate layer.

3. A security element according to claim 1, characterized in that the optical interference structure layer (2) is a thin-film optical interference structure layer forming a three-, five-or seven-layer symmetrical interference structure by means of physical or chemical deposition of metal and dielectric materials.

4. A security element according to claim 1, characterized in that the continuous carrier layer (1) is transparent, the thickness of the continuous carrier layer (1) being 1nm to 50 μm.

5. A security element according to claim 1, characterized in that the material of the continuous carrier layer (1) is an oxide, an inorganic salt, an organic salt, a resin or a combination thereof.

6. A security element according to claim 1, characterized in that the continuous carrier layer (1) is made of silica, silicate, titanium dioxide, titanate, alumina, aluminate, resin or a combination thereof.

7. A security element according to claim 1, characterized in that the functional particles (3) are completely enveloped by the continuous carrier layer, partially enveloped by the continuous carrier layer, on the surface of the continuous carrier layer, having two or three of the above states simultaneously.

8. A security element according to claim 1, characterized in that the functional particles (3) are spherical or platelet-shaped or irregularly shaped, the particle size of the functional particles being in the range of 1nm to 120 μm, the mass of the functional particles representing 0.01% to 70% of the total mass of the security element.

9. Use of a security element according to any of claims 1 to 8, characterized in that the security element is manufactured as a pigment and added to an ink or vehicle for spraying, injection moulding, printing or labeling, for security and decoration.