CN-121991447-A - Light-oxygen dual-response anti-counterfeiting composition, anti-counterfeiting film and application thereof

CN121991447ACN 121991447 ACN121991447 ACN 121991447ACN-121991447-A

Abstract

The invention discloses an anti-counterfeiting composition with light-oxygen dual response and application thereof, and belongs to the technical field of anti-counterfeiting. The composition consists of a polymer matrix, fluorescent probe molecules with free radical response color change function and RAFT reagent serving as a free radical source. Aiming at the technical pain point of the prior anti-counterfeiting material, the invention utilizes a RAFT reagent and a fluorescent probe to construct an oxygen-dependent photochemical response mechanism, wherein fluorescent probe molecules keep chemical stability to illumination under the condition of no oxygen sealing, after packaging is opened to contact oxygen, the RAFT reagent in the system is subjected to ultraviolet irradiation to homolytic cleavage to generate free radicals, and oxygen in the environment is synchronously activated to generate Reactive Oxygen Species (ROS). The ROS and the free radicals cooperatively induce the probe molecules to generate irreversible chemical structure transformation, so that a pi conjugated system of the probe molecules is expanded and a HOMO-LUMO band gap of the probe molecules is reduced, and further, the obvious red shift of an emission spectrum is generated, and the irreversible visual color change is realized. The invention has the advantages of high environmental stability, accurate response, irreversible record and the like, and can be widely applied to anti-counterfeiting tracing and opening state record of high-value products.

Inventors

HUANG WEIGUO
FENG SHIYU
XU SHIHUI

Assignees

中国科学院福建物质结构研究所

Dates

Publication Date: 20260508
Application Date: 20260127

Claims (10)

1. A light-oxygen dual response anti-counterfeiting composition, wherein the composition comprises the following three parts: A) A polymer matrix; B) Fluorescent probe molecules with free radical response color change function, wherein the fluorescent probe molecules are compounds containing phenanthridine functional groups; C) A free radical modulator selected from reversible addition-fragmentation chain transfer (RAFT) agents, the composition having an oxygen-dependent photochemical response property, the composition having chemical stability to ultraviolet light or ambient light under anaerobic or very low oxygen sealing conditions, maintaining a color unchanged; Under the anaerobic condition, the fluorescent probe molecules have chemical stability to illumination, under the aerobic condition, the RAFT reagent is homolytic to generate sulfur-containing free radicals and cyano-containing free radicals under the ultraviolet illumination, and meanwhile, oxygen in the environment is activated into active oxygen species which act on the fluorescent probe molecules in a synergistic way with the free radicals to induce irreversible color change.
2. The anti-counterfeiting composition according to claim 1, wherein, The RAFT reagent is selected from at least one of dithiobenzoate and trithiocarbonate compounds, and the molar ratio of the RAFT reagent to the fluorescent probe is (5-50): 1.
3. The anti-counterfeiting composition according to claim 2, wherein the RAFT agent is cumene dithiobenzoate (CPDTB).
4. The anti-counterfeiting composition according to claim 1, wherein the fluorescent probe molecule has a structure represented by formula P: Wherein R 1 is selected from at least one of H, C-20 alkyl, C1-6 alkyl halo, C1-6 alkyl primary amine, C1-6 alkyl secondary amine, C1-6 alkyl tertiary amine, C1-6 quaternary amine salt; Preferably, R 1 is C1-20 alkyl; R 2 is at least one selected from H, benzylamino, C1-20 alkyl, benzylamino, cyano, halogen, amino, C1-6 alkyl primary amine, C1-6 alkyl secondary amine, C1-6 alkyl tertiary amine and C1-6 quaternary amine salt; Preferably, R 2 is 4-cyanobenzylamine, n-butylamine, 4-methylbenzylamine, 4-methoxybenzylamine.
5. The anti-counterfeiting composition according to claim 1, wherein the polymer is selected from at least one of polymethyl methacrylate (PMMA), poly pentafluorophenyl acrylate (pPFPA), polybutadiene (PB), epoxy resin (EP), polydimethylsiloxane (PDMS), polystyrene (PS) derivatives.
6. A security film prepared on the basis of the security composition of any one of claims 1 to 5, characterized in that the thickness of the film is 100 μm to 1000 μm; The film has anaerobic light stability, namely, under the condition of inert atmosphere, the film is stored for at least 24 hours under the anaerobic sealing condition and is irradiated by ultraviolet light with the wavelength of 320-420 nm and the light power of more than or equal to 22W, and no irreversible color change visible to naked eyes occurs; the film has aerobic photosensitivity, and can generate irreversible color change visible to naked eyes in the same condition of ultraviolet irradiation for 0.1s-5min in an oxygen-containing environment.
7. A method of making an anti-counterfeiting film according to claim 6, comprising the steps of: s1, under the light-shielding condition, dissolving the polymer, the fluorescent probe molecules and the RAFT reagent in a solvent and uniformly mixing; S2, coating the mixed solution on a substrate, and drying the substrate to form a film under the conditions of no oxygen and light shielding.
8. Use of the anti-counterfeiting film according to claim 6 for preparing a packaging recycling prevention or secondary opening prevention label.
9. Use according to claim 8, wherein the label is configured to be integrated inside a sealing structure of a light-transmissive packaging container (e.g. a glass bottle); when the packaging container is in a sealed state, the label is in an anaerobic or hypoxia environment, and the label keeps stable color, so that the error color is prevented from being caused by ambient light penetrating through the packaging container; When the packaging container is opened, external oxygen enters into contact with the label, and the cascade reaction of the free radical and the active oxygen is triggered under illumination, so that the active oxygen and the fluorescent probe are subjected to cycloaddition and combined with the free radical addition, and the label is subjected to irreversible color change under illumination to indicate an opening event.
10. Use of the anti-counterfeiting composition according to claim 1 for preparing a smart monitoring label, wherein the smart label is used for indicating whether an oxygen leakage or an opening of a packaging container occurs.

Description

Light-oxygen dual-response anti-counterfeiting composition, anti-counterfeiting film and application thereof Technical Field The application relates to the fields of anti-counterfeiting technology and intelligent materials, in particular to a photo-oxygen dual-response anti-counterfeiting composition based on a free radical photo-oxidation mechanism, an anti-counterfeiting film prepared from the composition, and application of the film in package illegal opening prevention and package recovery prevention. Background The circulation of counterfeit and inferior products seriously damages the market order, especially in the fields of high-grade wines, cosmetics and medicines. Counterfeiters recover the genuine product packaging containers (such as wine bottles and medicine bottles), and re-fill the inferior products and sell the inferior products again. Because the appearance of the packaging container is true, the traditional externally-attached anti-counterfeiting label (such as a laser holographic label and a two-dimensional code) is difficult to effectively identify the counterfeiting behavior of the internal replacement. To address this problem, industry has begun to attempt to make "tamper-evident/tamper-evident labels" from irreversible color change materials that are placed inside packaging containers (e.g., at bottle cap seals). Ideally, when the product is opened, the label is exposed to the environment and changes color, thereby indicating that the package has been tampered with, preventing reuse. Among them, photochromatic materials (such as photochromic molecules and photopolymerisable materials) are attracting attention because of their remarkable color change and easy detection. However, when the existing photochromic anti-counterfeiting technology is applied to transparent or semitransparent packaging containers (such as glass wine bottles and transparent plastic bottles), a great technical challenge is faced: 1. False positive risk (poor shelf life stability) existing photochromic materials typically respond only to a single factor of illumination. However, common packaging materials (such as soda lime glass and PET plastic) can block short wave ultraviolet (UVB/UVC) but have high transmittance (generally more than 70%) to long wave ultraviolet (UVA, 320-420 nm) and visible light. This means that the product containing such a security tag is susceptible to false discoloration by irradiation of ambient light (containing UVA components) transmitted through the packaging container even when in an unopened state during storage, transportation or supermarket shelf display. The false positive phenomenon of 'unsealing and color changing first' causes the anti-counterfeiting label to lose efficacy before the product is sold, and severely limits the practical application of the anti-counterfeiting label. 2. The traditional single light response material cannot distinguish between the light transmitted through glass and the light after opening, so that the specific action of opening cannot be responded accurately. 3. The reversibility causes the safety to be insufficient, and part of the existing photochromic materials can recover or fade after being protected from light, or the color changing process is reversible, so that a counterfeiter can recover the color of the label through light-resistant treatment or chemical means, and the recovered package is reused. Although there are techniques using similar fluorescence molecule induction polymerization degree in the prior art (such as CN115168884 a), it relies on the physical free volume change of the polymer chain, and cannot distinguish the normal polymerization caused by illumination from the oxygen leakage caused by package breakage. Such techniques are prone to false positives (false positives) when exposed to light during anaerobic shelf life. Therefore, an intelligent gate control material is urgently needed in the anti-counterfeiting field. The material should have "environmental recognition" capability, i.e., remain color stable (to overcome false positives) even when exposed to light transmitted through the package within a sealed package (typically an oxygen deficient/anaerobic environment), and be able to quickly respond to light to undergo an irreversible color change upon opening of the package to contact an oxygen containing environment (including but not limited to air, pure oxygen, etc.). At present, the prior art does not provide a low cost solution capable of perfectly balancing the "shelf life photophobic stability" with the "post-opening color change sensitivity". Disclosure of Invention First, the technical problem to be solved The prior art light response anti-counterfeiting materials generally have the defect of single response factor (only responding to illumination). When the material is applied to the inside of transparent or semitransparent packaging containers (such as glass wine bottles and transparent PET bottles), long-wav