CN116416853A

CN116416853A - Dynamic anti-fake mark

Info

Publication number: CN116416853A
Application number: CN202111660613.4A
Authority: CN
Inventors: 请求不公布姓名
Original assignee: Quantaeye Beijing Technology Co ltd
Current assignee: Quantaeye Beijing Technology Co ltd
Priority date: 2021-12-31
Filing date: 2021-12-31
Publication date: 2023-07-11

Abstract

The application provides a dynamic anti-counterfeiting mark. The dynamic anti-counterfeiting mark comprises an anti-counterfeiting composition (1), wherein the anti-counterfeiting composition (1) comprises a photoinitiator and two or more quantum dot materials, and at least two quantum dot materials are different in emission wavelength and quenching time of emitted light generated under the same excitation condition, wherein the emission wavelength of the emitted light of the quantum dot materials is in a range of 350-780 nm; the same excitation condition at least comprises the same wavelength of excitation light, and the dynamic anti-counterfeiting mark is arranged as a label, ink, paint or condensate. The wavelength (color) of the emitted light of the dynamic anti-counterfeiting mark can show dynamic change after being stimulated, multi-dimensional information encryption (time of dynamic color change and color conversion) is realized, the dynamic anti-counterfeiting mark is difficult to imitate, and anti-counterfeiting safety is improved.

Description

Dynamic anti-fake mark

Technical Field

The application relates to the technical field of anti-counterfeiting, in particular to a dynamic anti-counterfeiting mark based on quantum dot materials.

Background

Quantum Dots (QDs) generally refer to nanocrystals having a radius less than or near the exciton bohr radius, and particularly to semiconductor nanocrystals (Semiconductor nanocrystal). The particle size of the quantum dots is typically from one nanometer to several tens of nanometers, and is usually spherical or spheroid in structure. Since electrons and holes are quantum confined, the continuous band structure becomes a discrete energy structure having molecular characteristics, and the band gap increases as the size decreases, the quantum dots may fluoresce after being excited and have various special physical effects (e.g., quantum size effect, surface effect, dielectric confinement effect, quantum tunneling effect, coulomb blockade effect, etc.).

At present, the quantum dot material is usually prepared from II-VI, IV-VI or III-V semiconductor materials, and common quantum dot materials comprise II-VI semiconductor quantum dots such as cadmium sulfide (CdS), cadmium tin (CdSe), cadmium telluride (CdTe), zinc sulfide (ZnS) and the like; IV-VI semiconductor quantum dots such as lead sulfide (PbS) and lead selenide (PbSe); III-V semiconductor quantum dots such as indium phosphide (InP) and indium arsenide (InAs). In addition, quantum dot materials based on perovskite structures and carbon quantum dot materials have also been developed.

In general, quantum dot materials can be widely applied in the fields of energy conversion, light-emitting display devices, photoelectric detection molecular probes, spectrum equipment, biological markers, development and the like. Recently, quantum dot materials are also increasingly used in the field of anti-counterfeit detection due to their fluorescent properties.

With the increasing demands of people for security documents or security articles, it is sometimes difficult to resist the risk of fraud and counterfeiting by merely relying on the detection of the characteristics of the emission wavelength of the quantum dot material after a single excitation. There is still room for further exploration of new quantum dot material-based anti-counterfeiting measures with higher security levels and more difficult imitation.

Disclosure of Invention

In order to realize anti-counterfeiting measures based on quantum dot materials with higher security level and more difficult imitation, the application provides a dynamic anti-counterfeiting mark.

The dynamic security marking comprises a security composition comprising a photoinitiator and two or more quantum dot materials, and,

at least two quantum dot materials have different emission wavelengths and quenching times of emitted light generated under the same excitation condition, wherein,

the emission wavelength of the emitted light of the quantum dot material is in the range of 350-780 nm;

the same excitation condition includes at least that the wavelengths of the excitation light are the same,

the dynamic security tag is configured as a label, ink, paint or cured.

In at least one embodiment, the dynamic security tag is configured as the label, the label further comprising a substrate, a sealing layer and a light shielding layer,

the substrate is provided with a groove, the anti-counterfeiting composition is arranged in the groove, the sealing layer covers the substrate, so that the anti-counterfeiting composition is sealed, and one surface of the sealing layer, which is far away from the substrate, is provided with the shading layer.

In at least one embodiment, the material of the substrate, the sealing layer is a flexible material, enabling the label to flex.

In at least one embodiment, the dynamic security tag is configured as a label, the label further comprising a substrate and a light shielding layer,

the anti-counterfeiting composition protrudes out of the substrate, and the shading layer is coated on the anti-counterfeiting composition.

the substrate is provided with a groove, the anti-counterfeiting composition is arranged in the groove, and the light shielding layer is arranged on one surface of the anti-counterfeiting composition, which is not contacted with the groove.

In at least one embodiment, the material of the substrate is a flexible material so that the tag can be folded.

In at least one embodiment, the dynamic security marking is configured as the ink comprising the security composition, the ink further comprising one or more of an offset base ink, a gravure base ink, a varnish, or a gloss oil.

In at least one embodiment, the dynamic security marking is configured as the coating comprising the security composition, the coating further comprising one or more of a polyester resin, a polyether resin, a vinyl chloride polymer and a vinyl chloride copolymer, a nitrocellulose resin, a cellulose acetobutyrate or cellulose levulinate resin, a maleic resin, a polyamide, a polyolefin, a polyurethane resin, a functionalized polyurethane resin, a polyurethane alkyd resin.

In at least one embodiment, the dynamic security tag is configured to include the cured product of the security composition, which is a dry product of the security composition.

In at least one embodiment, the dynamic security marking is configured to include the cured product of the security composition, the cured product further including a resin, the quantum dot material in the security composition being dispersed in the cured product.

In at least one embodiment, the dynamic anti-counterfeiting mark further comprises a shading layer coated on the outer side of the ink body, the outer side of the coating body or the outer side of the solidified body.

In at least one embodiment, the anti-counterfeiting composition comprises 2 to 10 quantum dot materials, and under the same excitation condition, the difference of emission wavelengths of the quantum dot materials is more than 15nm, and the quenching time of the quantum dot materials is more than 0.5 s.

In at least one embodiment, the anti-counterfeiting composition further comprises one or more of a photopolymerizable monomer, a photopolymer reactive oligomer, a coupling agent, a solvent;

the emitted light of the quantum dot material under the excitation condition comprises fluorescence, phosphorescence or delayed fluorescence;

the atmosphere of the anti-counterfeiting composition is an aerobic atmosphere or an anaerobic atmosphere, the solvent atmosphere of the anti-counterfeiting composition is an organic solvent or water, and the temperature of the anti-counterfeiting composition is in the range of-30-60 ℃;

the emission wavelength or quenching time of the quantum dot material has at least one of an atmosphere responsiveness, a solvent atmosphere responsiveness, or a temperature responsiveness.

The wavelength (color) of the emitted light of the dynamic anti-counterfeiting mark can show dynamic change after being stimulated, multi-dimensional information encryption (time of dynamic color change and color conversion) is realized, the dynamic anti-counterfeiting mark is difficult to imitate, and anti-counterfeiting safety is improved. The anti-counterfeiting composition has stable optical performance and chemical performance, the whole technical scheme is simple to operate, easy to popularize in a large scale, and has low requirements on detection conditions during detection.

Drawings

Fig. 1 shows a schematic structural diagram of a dynamic security tag in the form of a label according to an embodiment of the present application.

Description of the reference numerals

1 an anti-counterfeiting composition; 2 a substrate; 3, sealing layers; 4 a light shielding layer.

Detailed Description

The following is a detailed description of the present application. The following description of the technical features is based on the representative embodiments and specific examples of the present application, but the present application is not limited to these embodiments and specific examples. It should be noted that:

in the present specification, the numerical range indicated by "numerical values a to B" means a range including the end point value A, B.

In the present specification, "room temperature" means a temperature range of 10 to 35 ℃.

In the present specification, the meaning of "can" includes both the meaning of performing a certain process and the meaning of not performing a certain process.

In the present specification, "quantum dot" and "quantum dot crystal", "quantum dot material" have the same physical and chemical meanings.

In this specification, "optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

Reference throughout this specification to "some specific/preferred embodiments," "other specific/preferred embodiments," "an embodiment," and so forth, means that a particular element (e.g., feature, structure, property, and/or characteristic) described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it is to be understood that the elements may be combined in any suitable manner in the various embodiments.

The present application provides a dynamic security tag comprising a security composition 1.

The security composition 1 comprises a photoinitiator and two or more different quantum dot materials. After being excited, different quantum dot materials have different emission light quenching time and emission wavelength under the influence of a photoinitiator, and the displacement of the wavelength of the emission light or the change of the color of the emission light of the quantum dot materials can be dynamically detected or observed in the detection time.

The dynamic anti-counterfeiting mark can have various use forms.

Illustratively, as shown in FIG. 1, the dynamic security device is in the form of a label. The dynamic security marking in the form of a label comprises a security composition 1, a substrate 2, a sealing layer 3 and a light-shielding layer 4. The security composition 1 herein may be in a liquid or solid state.

The substrate 2 is provided with a recess in which the security composition 1 may be disposed. The grooves may be of any shape, and after the anti-counterfeiting composition 1 is arranged in the grooves, specific symbols, figures, letters, characters, numbers, marks, pictures and combinations thereof can be presented according to the shapes of the grooves. The present application is not limited to a particular type of material of the substrate 2, and may be polytetrafluoroethylene or other materials, for example.

A sealing layer 3 is attached to the substrate 2 and seals the security composition 1 in the groove of the substrate 2. The specific type of material of the sealing layer 3 is not limited in this application and may be, for example, plastic, quartz or other materials.

The light-shielding layer 4 is arranged on the side of the sealing layer 3 remote from the security composition 1. The light shielding layer 4 can be scraped off during use, and the failure of the anti-counterfeiting composition 1 caused by light exposure in advance can be avoided. The specific kind of material of the light shielding layer 4 is not limited in the present application, and for example, a commercially available screen printing ink may be used. When in use, the shading layer 4 is scraped off, the anti-counterfeiting composition 1 is irradiated by ultraviolet rays, and the color of the anti-counterfeiting composition 1 is dynamically changed along with illumination.

The side of the substrate 2 far away from the shading layer 4 can be provided with adhesive glue, so that the dynamic anti-counterfeiting mark in the form of a label is conveniently adhered to an article needing anti-counterfeiting.

It will be appreciated that in the case where the security composition 1 is in a solid state, the light-shielding layer 4 may be directly provided on the security composition 1 without providing the sealing layer 3.

For example, in the case where the anti-counterfeiting composition 1 is in a solid state, the anti-counterfeiting composition 1 may be disposed on the substrate 2 in a protruding manner, and the light shielding layer 4 may be coated on the anti-counterfeiting composition 1. In this embodiment, the substrate 2 need not be provided with grooves, and the sealing layer 3 may not be provided.

The material of the substrate 2 and the sealing layer 3 may be flexible, for example polyimide, so that the security tag can be attached to a curved surface.

For example, the dynamic security marking may be in the form of ink. The dynamic security marking, which is presented as an ink, optionally comprises one or more components of offset, gravure, varnish or varnish in addition to the security composition 1.

For example, the dynamic security marking may be in the form of a paint. Dynamic security markings in the form of coatings may also contain other resin components such as one or more of polyester resins, polyether resins, vinyl chloride polymers and copolymers of vinyl chloride, nitrocellulose resins, cellulose acetobutyrate or cellulose levulinate resins, maleic resins, polyamides, polyolefins, polyurethane resins, functionalized polyurethane resins, polyurethane alkyd resins, and the like. The composition of the components can be adjusted to make the dynamic security marking suitable for inkjet printing or spraying.

Illustratively, the dynamic security marking may be present as a cured product, for example as a dried product of security composition 1. Alternatively, the dynamic security device is a cured product formed by combining the security composition 1 and the resin. In particular, when the security composition 1 has a polymerizable component (for example, a photopolymerizable monomer, described later), the security composition 1 may be polymerized with a resin by irradiation to form a crosslinked or non-crosslinked resin cured product, and the quantum dot material may be uniformly dispersed in the cured product under the action of a photoinitiator, preferably, the quantum dot material and the resin component have covalent bond connection. The solidified material can be used as an anti-counterfeiting layer and is arranged on a product needing anti-counterfeiting in a printing or pasting mode.

The present application is not particularly limited to the manner of shading the ink, paint, and cured product comprising the security composition 1, and the form of combination with the product to be provided with the dynamic security marking. Illustratively, the ink, coating, and cured product provided herein further include a light shielding layer 4 that covers the body outside of the ink, the body outside of the coating, and the body outside of the cured product.

The application describes the anti-counterfeiting composition 1 in more detail according to the description logic of the quantum dot material, the anti-counterfeiting composition 1 and the anti-counterfeiting code.

(Quantum dot Material)

The inclusion of two or more different quantum dot materials in the security composition 1 means that the emitted light of the quantum dots in the security composition 1 have different emission wavelengths and quenching times under the same excitation conditions. Also, in some specific embodiments of the present application, the same excitation conditions also include at least one of an atmosphere, a solvent atmosphere, or a temperature condition when the quantum dot material is excited.

In this application, as the quantum dot material, two or more kinds of quantum dot materials may be used in combination. The quantum dot materials are in principle not particularly limited as long as the emission wavelength and the quenching time of the emitted light, which are different under the same excitation condition, of at least two quantum dot materials contained therein in the security composition 1 are satisfied.

For quantum dot materials suitable for use in the present application, in some specific embodiments may include:

group II-VI semiconductor quantum dot materials such as cadmium sulfide (CdS), cadmium stannate (CdSe), cadmium telluride (CdTe), and zinc sulfide (ZnS);

IV-VI semiconductor quantum dot materials such as lead sulfide (PbS), lead selenide (PbSe) and the like;

III-V semiconductor quantum dot materials such as indium phosphide (InP) and indium arsenide (InAs);

quantum dot materials of core-shell structure such as CdS/ZnS, cdSe/CdS, cdSe/ZnS, cdSe/CdS/ZnS, cdTe/CdS/ZnS, znSe/ZnS, inP/ZnSe, inP/ZnS, inP/ZnSe/ZnS, inP/GaP/ZnS;

precious metal simple substances such as Au, ag and other quantum dot materials;

and one or more of a perovskite structure-based quantum dot material, a carbon quantum dot material, and the like.

Further, the method for synthesizing these quantum dot materials is not particularly limited, and these methods may be organic medium-based methods or aqueous medium-based methods.

In some specific embodiments of the present application, quantum dot materials suitable for use in the present application may be selected from colloidal quantum dot materials. For such a synthesis method of quantum dot material, typically, the raw materials may be first dissolved in an organic solvent or a ligand, respectively, to form a precursor, and then mixed under heating to form quantum dots through chemical reaction.

In the above-mentioned organic solvent or ligand, the organic solvent itself may be a ligand in the preparation of the precursor, and thus the organic solvent may be generally classified into a ligand-based organic solvent and a non-ligand-based organic solvent.

In some specific embodiments of the present application, the ligand or ligand-based solvent generally has a relatively high boiling point (preferably, a boiling point above 300 ℃) and dissolves the starting material to form the quantum dot precursor. Some polar organic solvents having long-chain alkyl groups are common as the ligand or ligand-based solvent, and include acid compounds having long-chain alkyl groups, amine compounds, thiol compounds, phosphorus-containing compounds, and the like. Specific examples include oleylamine, dodecylmercaptan, oleic acid, dioctyl ether, trioctylphosphine oxide (TOPO), trioctylphosphine (TOP), hexylphosphonic acid (HPA), tetradecylphosphonic acid (TDPA), and mixtures thereof.

For non-ligand solvents, octadecene, diphenyl ether, paraffin oil, methyl pyrrolidone, etc. are generally used. When the reaction temperature is allowable, the non-ligand solvent may be a low boiling point solvent such as ethanol or toluene. For the use of non-ligand solvents, the precursor may be dissolved or dispersed in these solvents after the quantum dot precursor is obtained using the ligand or ligand-based solvent dissolution starting materials.

After preparing the precursors by means of the ligand or the ligand organic solvent respectively, two or more precursors are injected into other organic solvents simultaneously, and the growth reaction of quantum crystals is carried out under the condition of heating; alternatively, one ligand may be injected into another ligand solution, and the quantum crystal growth reaction may be performed under heating.

The above raw materials (mainly sources of various elements in the quantum dots) may be one or more of simple substances, oxides, salt compounds, organic compounds and the like thereof. For example, in some specific embodiments, in synthesizing A _x B _y In the case of the quantum dot type (wherein A may be Cd, hg, pb, zn, ag, cu, mn, sn, ni, bi, eu, etc., and B may be S, se, te), an oxide, a salt compound, or an organic compound of A may be dissolved in a ligand or a ligand-based organic solvent to obtain a precursor. In addition, the simple substance of B is dissolved in an organic solvent to form other precursors, and then the two precursors are mixed in a heating state to prepare the quantum dot.

The temperature conditions for preparing the quantum dots are not particularly limited, and for example, in the thermal injection method, the reaction temperature may be controlled to be in the range of 180 to 380 ℃ as needed.

In other specific embodiments of the present application, quantum dot materials suitable for use in the present application may be selected from aqueous medium synthesized quantum dot materials, such as perovskite-type quantum dot materials. The method for synthesizing such a quantum dot material is not particularly limited, and the quantum dot material may be obtained by dissolving a raw material in water and performing hydrothermal synthesis in the presence of a surfactant. Such a surfactant may be a compound having a bipolar head, and typically may be an alkyl acid compound having a mercapto group or the like.

In addition, carbon quantum dot materials may also be used for the quantum dot materials of the present application. The carbon source (e.g., citric acid, etc.) and the nitrogen source (e.g., amine compound) are usually heated at 150 to 300 ℃ and then dispersed in water.

In addition, without limitation, in order to adjust the optical characteristics (for example, adjust the wavelength of emitted light) required for the quantum dot material, other elements, for example, rare earth elements, may be doped in the preparation process of the various quantum dot materials, or the obtained quantum dot material may be subjected to surface modification, or the like.

There is no particular limitation on the surface modification, and for example, in order to obtain quantum dot materials with different characteristics, or to satisfy the application of quantum dots in different application fields, for example, to improve the redispersibility of quantum dot materials in different physical and chemical occasions, and to improve or enhance the photoelectric properties of quantum dot materials, it is necessary to adjust the ligand of quantum dot materials obtained from a synthesis stock solution or to surface modify the quantum dot materials. It is possible to cite that the quantum dot material obtained by a general thermal injection method has oil solubility, but if the material needs to be redispersed in an aqueous system, the ligand on the surface of the quantum dot needs to be adjusted. Therefore, the adjustment of the ligands on the surface of the quantum dots also determines the use effect. In some specific embodiments, the surface modification described above is performed by ligand exchange. Illustratively, such surface modification may be performed by introducing a second, third or more additional ligands.

In this application, the morphology of the quantum dot material is not particularly limited, and in some specific embodiments, it may be a crystalline material having a certain shape. Typically, the morphology of the quantum dot material of the present application may have, for example, a spherical or substantially spherical structure, a rod-like structure, a sheet-like structure, a cone-like structure, a tower-like structure, a polygonal structure, a cube structure, or the like. In some preferred embodiments of the present application, the resulting quantum dot crystals have a spherical or substantially spherical morphology; in other preferred embodiments, the resulting quantum dot crystals have a (spherical or substantially spherical) core-shell structure.

The particle size of the quantum dot material of the present application is not particularly limited, and in some specific embodiments of the present application, it may be 1 to 100nm, preferably, the particle size range may be 2 to 70nm, more preferably 2 to 60nm, still more preferably 2 to 50nm, still more preferably 3 to 30nm, 3 to 20nm, or 3 to 10nm.

In addition, in the present application, the quantum dot material of the present application may include at least fluorescence emission after being excited, or in other specific embodiments, the emission light species in the quantum dot material may include phosphorescence emission or (thermal) delayed fluorescence emission in addition to fluorescence.

(anti-counterfeiting composition 1)

The anti-counterfeiting composition 1 of the application primarily comprises two or more quantum dot materials. In some preferred embodiments, the anti-counterfeiting composition 1 of the present application comprises 2 to 10, more preferably 3 to 5 quantum dot materials. The security composition 1 further comprises a photoinitiator (described below).

For the composition forms of the quantum dot materials described above, in some specific embodiments, a plurality of quantum dot materials may be dispersed in a solvent to form a dispersion system. The kind of the solvent is not particularly limited, and various solvents commonly used in the art may be used. The concentration of each quantum dot in the dispersion system is not particularly limited, and may be adjusted according to the excitation characteristics, and thus the concentrations of different quantum dot materials need not be the same. In some specific embodiments, the concentration of total quantum dot material in the security composition 1 may be from 1 to 40% by volume (volume percent), preferably from 3 to 25% by volume.

In some embodiments, the emission wavelength and/or quenching time of the quantum dot material in the anti-counterfeiting composition 1 of the present application has one or more of an atmospheric atmosphere, a solvent atmosphere, or a temperature condition (which changes with changes in conditions).

In some specific embodiments, the wavelength of the emitted light of the quantum dot material in the security composition 1 may be 350 to 780nm, and from the viewpoint of recognition convenience, the preferred wavelength of the emitted light is 380 to 640nm, more preferably 440 to 570nm. For the wavelength of the excitation light, it may be 254 to 395nm, preferably 350 to 390nm, in some specific embodiments.

Further, in some preferred embodiments of the present application, 3 to 5 quantum dot materials having different emission wavelengths and quenching times of emitted light under the same excitation conditions are included in the security composition 1.

For emission wavelengths, in some specific embodiments of the present application, the difference in emission wavelength between the two quantum dot materials may be 15nm or more, preferably 30nm or more, and more preferably 60nm or more; the upper limit value of the difference in wavelength of emitted light is not particularly limited, and may be generally 200nm or less, preferably 150nm or less, to prevent the difference in wavelength of emitted light from being too small, thereby reducing the convenience of detection; and preventing the wavelength difference of the emitted light from being excessively large, and the requirement for the detection wavelength range of the detection instrument is high.

The quenching time in the present application refers to a phenomenon in which emitted light generated upon irradiation of excitation light is attenuated or terminated in the anti-counterfeit composition 1. The quenching time of the quantum dots in the anti-counterfeiting composition 1 is related to the optical characteristics of the quantum dot material, other components in the anti-counterfeiting composition 1 and the detection environment. More specifically, the present application refers to the quenching time of the quantum dot material when the emission intensity or quantum efficiency at t time after the start of excitation light irradiation is 20% or less of the emission intensity or quantum efficiency at the time of the initial irradiation. In some embodiments of the present application, the quenching time difference between the two quantum dot materials may be more than 0.5s, and in some embodiments, the quenching time difference may be from 1s to 60s, preferably from 5 to 40s, and more preferably from 15 to 30s. Further, the quenching time or the difference in quenching time of each quantum dot material may be adjusted by the selection of the quantum dot material or the composition of the anti-counterfeit composition 1, and physical, chemical, or temperature conditions at the time of detection, and the like.

For the photoinitiator of the present application, one or more cleavage type initiators may be selected, and examples include benzoin derivatives, benzil ketal derivatives, dialkoxyacetophenones, α -hydroxyalkylphenones, α -aminoalkylphenones, acylphosphine oxides, esterified oxime ketone compounds, arylperoxy ester compounds, halomethyl aryl ketones, organic sulfur compounds, benzoyl formate and the like. In addition, for the concentration of the photoinitiator, in some specific embodiments, the photoinitiator may be 0.5 to 4 weight percent (mass percent) based on the total mass of the anti-counterfeiting composition 1.

For photoinitiators, which can generate free radicals under illumination, quantum dot materials with different emission wavelengths have different efficiency of capturing free radicals, resulting in different quenching orders of quantum dots with different emission wavelengths, and a process of displaying color change with irradiation time. In addition, preferably, in the case where a monomer (photopolymerizable monomer) is present in a system as described below, the abstraction of a radical by the quantum dot material and the polymerization and curing of the monomer are performed simultaneously, and the radical is difficult to move after the curing of the monomer is completed, and thus, a change process of color can be more conveniently exhibited.

The photoinitiator can play a main role in color regulation and control, and the quenching sequence of the quantum dots is determined according to the electron gain and loss capability of the quantum dot material. In some specific embodiments, the color change time may be adjusted by the amount of photoinitiator.

For other components in the anti-counterfeiting composition 1 of the present application, in some specific embodiments, these other components may include: one or more of a photopolymerizable monomer, a photopolymer reactive oligomer, a coupling agent, a solvent, and the like.

For the photopolymerizable monomer, one or more selected from the group consisting of (meth) acrylic acid, (meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate, trifunctional or more poly (meth) acrylate, and the like may be used.

The photopolymerizable reactive oligomer may be one or more selected from oligomers or prepolymers of an acrylic monomer having terminal photoactivity, and the molecular weight thereof may be generally 2000 or less, preferably 1000 or less, and more preferably 800 or less.

The coupling agent is not particularly limited, and may be selected from one or more of silane coupling agents.

The solvent is not particularly limited, and may be an organic solvent or water. Examples of such solvents include, but are not limited to, alcohols (e.g., methanol, ethanol, isopropanol, n-propanol, ethoxypropanol, n-butanol, sec-butanol, tert-butanol, isobutanol, 2-ethylhexanol, and mixtures thereof);

polyols (e.g., glycerol, 1, 5-pentanediol, 1,2, 6-hexanetriol, and mixtures thereof);

esters (e.g., ethyl acetate, n-propyl acetate, n-butyl acetate, and mixtures thereof);

carbonates (e.g., dimethyl carbonate, diethyl carbonate, di-n-butyl carbonate, 1, 2-ethylene carbonate, 1, 2-propylene carbonate, 1, 3-propylene carbonate, and mixtures thereof);

aromatic solvents (e.g., toluene, xylene, phenylcyclohexane, and mixtures thereof);

ketones and ketoalcohols (e.g., acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, diacetone alcohol, and mixtures thereof);

amines (e.g., dimethylformamide, dimethylacetamide, and mixtures thereof);

aliphatic or alicyclic hydrocarbons;

chlorinated hydrocarbons (e.g., methylene chloride, chloroform, or mixtures thereof); nitrogen-containing heterocyclic compounds (e.g., N-methyl-2-pyrrolidone, 1, 3-dimethyl-2-imidazolidinone, and mixtures thereof);

ethers (e.g., diethyl ether, tetrahydrofuran, dioxane, and mixtures thereof);

alkyl ethers of polyols (e.g., 2-methoxyethanol, 1-methoxypropan-2-ol, and mixtures thereof);

alkylene glycol, alkylene thioglycol, polyalkylene glycol or polyalkylene thioglycol (e.g., ethylene glycol, polyethylene glycol (e.g., diethylene glycol, triethylene glycol, tetraethylene glycol), propylene glycol, polypropylene glycol (e.g., dipropylene glycol, tripropylene glycol), butylene glycol, thiodiglycol, hexylene glycol, and mixtures thereof);

nitriles (e.g., acetonitrile, propionitrile, and mixtures thereof), and sulfur-containing compounds (e.g., dimethyl sulfoxide, sulfolane, and mixtures thereof).

Preferably, the organic solvent includes a solvent having a high boiling point (boiling point 150 ℃ or more) or a polar solvent.

(anti-counterfeiting code)

By adjusting the composition of the above-described security composition 1, such as the type, content, photoinitiator concentration, etc., of the quantum dot material, encoding of the following security features can be achieved.

In some specific embodiments of the present application, when the security composition 1 is present as a solvent-containing solution, the security composition 1 is irradiated with an excitation light source. The total irradiation time of the excitation light source is T, and at the irradiation starting time point T0, the quantum dot material in the anti-counterfeiting composition 1 is stimulated to generate emission light with two or more wavelengths; upon reaching the illumination time point T1, at least one quantum dot material in the anti-counterfeiting composition 1 produces an emission light quench, and at least one additional quantum dot material has not produced an emission light quench. At this time, the observer or detector can detect a change in the wavelength or color of the emitted light of the anti-counterfeit composition 1 at the time points of T0 and T1.

In other cases, if irradiation is still continued after time point T1, at least one quantum dot material in the anti-counterfeiting composition 1 again generates emission light quenching when reaching irradiation time point T2, and at least one additional quantum dot material has not generated emission light quenching yet; further by analogy, an observer or detector can detect a change in the wavelength or color of the emitted light of the security composition 1 at the time points of T0 and T1, T2 … … Tn.

By selecting and co-using the quantum dot materials, for example, adjusting the kind and amount/concentration of the quantum dot materials, etc., two or more kinds of changes in emission wavelength or color can be dynamically observed over the entire irradiation time T as long as a suitable combination of quenching times is selected. According to such a principle, the quantum dot material composition of the anti-counterfeit composition 1 may be designed in advance, and anti-counterfeit authentication may be performed according to a change in color or according to one or more time points of the change in color when anti-counterfeit detection is performed.

Also, in other specific embodiments of the present application, where the security composition 1 is presented in the form of a dried label, feature or coating, the feature of producing a change in wavelength or color of emitted light at different illumination times may also be achieved by the selection and coordination of quantum dot materials.

In addition, as previously described, the emission wavelength and/or quenching time of the quantum dot material in the anti-counterfeiting composition 1 of the present application has one or more of the condition responsivity of the atmosphere, the solvent atmosphere, or the temperature condition. For example:

a. when the solvent type in the anti-counterfeiting composition 1 is changed, the dynamic optical change characteristic of the anti-counterfeiting composition 1 in the illumination time can be changed;

b. when a (different) solvent is applied to the solvent-free dry anti-counterfeiting composition 1, the dynamic optical change characteristics of the anti-counterfeiting composition 1 during the illumination time can be changed;

c. when changing the atmosphere of the security composition 1 (e.g., an aerobic atmosphere and an anaerobic atmosphere), the dynamic optical change characteristics of the security composition 1 during the illumination time can be changed;

d. when the detection temperature is changed (e.g., in the range of-30 to 60 ℃ or in the room temperature range), the dynamic optical change characteristics of the anti-counterfeiting composition 1 during the illumination time can be changed.

The dynamic optically variable features described above include at least the color features of dynamic light variation and the temporal features of dynamic light variation.

Accordingly, the present application may also perform security coding on the security composition 1 according to the above-described responsiveness.

The application also provides an anti-counterfeiting identification method for identifying whether the security document or the security product with the anti-counterfeiting composition 1 is true or false.

Specifically, the authentication method includes:

i) Acquiring an article with a dynamic anti-counterfeiting mark;

ii) the dynamic security marking of the article is irradiated by excitation light having a wavelength of 254 to 395nm, preferably 360 to 390nm, and in some specific embodiments, the illumination power may be 5 to 20W.

For illumination time, the luminescence or quenching characteristics of the quantum dot material in the anti-counterfeiting composition 1 are related. Generally, the illumination time is sufficient to produce quenching of at least a portion of the quantum dot material. In some preferred embodiments, the illumination time may be no more than 200s, preferably no more than 150s, more preferably no more than 120s. It can be understood that under the condition that the illumination time is enough to cause the change of the wavelength of the emitted light of the quantum dot material in the anti-counterfeiting composition 1 caused by the quenching intermittent occurrence, the shorter the illumination time, the better the illumination time, which is beneficial to improving the convenience of detection.

Detecting whether the anti-counterfeiting composition 1 generates a change of the wavelength of emitted light in the period of time of irradiation of the excitation light or detecting the time when the anti-counterfeiting composition 1 generates a change of the wavelength of emitted light in the period of time of irradiation of the excitation light, and recording the characteristics or the information, and further comparing the characteristics and the information with standard information of the anti-counterfeiting composition 1 based on the application. The standard information may be obtained in advance or detected in advance based on information provided by the supplier of the anti-counterfeit composition 1 of the present application.

For the information available for comparison, additional information obtained by changing the detection condition (excitation condition) or the like may be also used, for example:

(1) exciting a dynamic anti-counterfeiting mark (a dry object) to be detected, and recording detection information F1; further, with the addition of an additional solvent, the same excitation light was irradiated, and detection information F2 was recorded. Comparing the information of F1 and/or F2 with standard information; or (b)

(2) Exciting a dynamic anti-counterfeiting mark to be detected in an oxygen-free atmosphere, and recording detection information F1; and exciting the security mark to be detected under the oxygen atmosphere, and recording detection information F2. The information of F1 and/or F2 is compared with standard information.

Of course, the present application may perform any desired encoding and accordingly may have an identification method matching it.

In the present application, the above-described authentication method can be realized by automatic detection by various optical devices and a computer, and the present application is not particularly limited to these devices or a software program matching them.

Examples

The present application is further described below in connection with examples.

< raw materials >

(Quantum dot)

Quantum dot QD-1, laboratory synthesis: (CdSe), the wavelength of emitted light was 630nm.

Quantum dot QD-2, laboratory synthesis: (CdSe), the wavelength of emitted light is 510nm.

Quantum dot QD-3, laboratory synthesis: (CdSe), the wavelength of emitted light was 450nm.

Quantum dot QD-4, laboratory synthesis: (InP) and the wavelength of the emitted light is 630nm.

Quantum dot QD-5, laboratory synthesis: (InP) and the wavelength of the emitted light is 510nm.

Quantum dot QD-6, laboratory synthesis: (InP) and the wavelength of the emitted light is 450nm.

(photopolymerizable monomer)

Isobornyl acrylate, commercially available, analytically pure;

1, 6-hexanediol diacrylate, commercially available, analytically pure.

(solvent)

Chloroform, phenylcyclohexane, commercially available, analytically pure.

(photoinitiator)

1173: 2-hydroxy-2-methyl-1-phenyl-1-propanone, abbreviated HMPP;

TPO: (2, 4, 6-trimethylbenzoyl chloride) diphenyl phosphine oxide;

184: 1-hydroxycyclohexyl phenyl ketone.

< irradiation conditions >

Temperature: 30 ℃;

excitation light wavelength: 365nm;

power: 20W.

Examples 1 to 12 and comparative examplesExample 1:

anti-counterfeiting composition 1 was configured as follows in table 1:

table 1:

examples and comparative examples preparation procedure:

the quantum dots with different emission wavelengths are uniformly mixed according to the proportion, and the photoinitiator is dissolved in the solvent (and the monomer) according to the proportion. And then adding the photoinitiator solution into the mixed quantum dots according to a proportion, and uniformly mixing. The resulting mixture was dropped onto the surface of a cover slip and illuminated. For an anaerobic environment, the cover glass is placed in the anaerobic environment for illumination.

The compositions (anti-counterfeit composition 1) in examples 1 to 12 and comparative example 1 were irradiated under the above irradiation conditions, and the change in color was observed.

The results are shown in Table 2 below:

table 2:

comparative example 1 was irradiated under the above irradiation conditions, and the change in color was observed, and the results are shown in the following table 3:

table 3:

aerobic conditions	Anaerobic conditions
		No color change during 120s of irradiation	No color change during 120s of irradiation

In the above, in the anti-counterfeit compositions 1 of examples 1 to 12, the quenching time under the irradiation condition was different in different kinds of quantum dots under the aerobic or anaerobic condition, so that the distinguishable color (emission wavelength) was changed during the irradiation time.

In comparative example 1, although different kinds of quantum dot materials were used in the anti-counterfeit composition 1, the photoinitiator was absent, resulting in that no change in the composition color was observed.

The embodiments of the present application have been described above, the foregoing description is exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the various embodiments described. The terminology used herein was chosen in order to best explain the principles of the embodiments, the practical application, or the technical improvements in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A dynamic security marking, characterized in that it comprises a security composition (1), said security composition (1) comprising a photoinitiator and two or more quantum dot materials, and,

the dynamic security tag is configured as a label, ink, paint or cured.

2. The dynamic security marking as claimed in claim 1, characterized in that the dynamic security marking is provided as the label, which further comprises a substrate (2), a sealing layer (3) and a light-shielding layer (4),

the substrate (2) is provided with a groove, the anti-counterfeiting composition (1) is arranged in the groove, the sealing layer (3) covers the substrate (2) so that the anti-counterfeiting composition (1) is sealed, and one surface, far away from the substrate (2), of the sealing layer (3) is provided with the shading layer (4).

3. Dynamic security marking according to claim 2, characterized in that the material of the substrate (2), the sealing layer (3) is a flexible material enabling the label to be bent.

4. Dynamic security marking according to claim 1, characterized in that the dynamic security marking is provided as the label, which label further comprises a substrate (2) and a light shielding layer (4),

the anti-counterfeiting composition (1) protrudes out of the substrate (2), and the light shielding layer (4) is coated on the anti-counterfeiting composition (1).

5. Dynamic security marking according to claim 1, characterized in that the dynamic security marking is provided as the label, which label further comprises a substrate (2) and a light shielding layer (4),

the substrate (2) is provided with a groove, the anti-counterfeiting composition (1) is arranged in the groove, and the light shielding layer (4) is arranged on one surface of the anti-counterfeiting composition (1) which is not contacted with the groove.

6. Dynamic security marking according to claim 4 or 5, characterized in that the material of the substrate (2) is a flexible material, so that the label can be folded.

7. The dynamic security marking of claim 1, wherein the dynamic security marking is arranged to contain the ink of the security composition (1), the ink further comprising one or more of an offset base ink, a gravure base ink, a varnish or a gloss oil.

8. The dynamic security marking of claim 1, wherein the dynamic security marking is configured as the coating comprising the security composition (1), the coating further comprising one or more of a polyester resin, a polyether resin, a vinyl chloride polymer and a vinyl chloride copolymer, a nitrocellulose resin, a cellulose acetobutyrate or cellulose acetopropionate resin, a maleic resin, a polyamide, a polyolefin, a polyurethane resin, a functionalized polyurethane resin, a polyurethane alkyd resin.

9. Dynamic security marking according to claim 1, characterized in that the dynamic security marking is arranged to contain the cured product of the security composition (1), which is a dry product of the security composition (1).

10. The dynamic security marking of claim 1, characterized in that the dynamic security marking is arranged to comprise the cured product of the security composition (1), the cured product further comprising a resin, the quantum dot material in the security composition (1) being dispersed in the cured product.

11. The dynamic security marking of any of claims 7 to 10, further comprising a light shielding layer (4) covering the outer side of the body of the ink, the outer side of the body of the paint or the outer side of the body of the cured product.

12. The dynamic security marking of any of claims 1 to 5, 7 to 10, wherein the security composition (1) comprises 2 to 10 of the quantum dot materials, the difference in emission wavelength of each of the quantum dot materials is 15nm or more and the quenching time of each of the quantum dot materials is 0.5s or more under the same excitation condition.

13. The dynamic security marking of claim 12, wherein the security composition (1) further comprises one or more of a photopolymerizable monomer, a photopolymer reactive oligomer, a coupling agent, a solvent;

the atmosphere of the anti-counterfeiting composition (1) is an aerobic atmosphere or an anaerobic atmosphere, the atmosphere of the solvent of the anti-counterfeiting composition (1) is an organic solvent or water, and the temperature of the anti-counterfeiting composition (1) is in the range of-30-60 ℃;