Novel eavesdropping protective film and preparation method thereof

Abstract

The invention relates to the technical field of laser eavesdropping protection, in particular to a novel eavesdropping protective film and a preparation method thereof, and the specific technical scheme is as follows: the novel eavesdropping protective film sequentially comprises a scratch-resistant layer, a laser barrier protective layer, an anti-ultraviolet mounting adhesive layer and a release film; wherein the laser barrier protective layer comprises a base material layer and a laser infrared absorption layer, and the base material layer is in contact with the scratch-resistant layer and the anti-ultraviolet mounting adhesive layer; the laser infrared absorption layer comprises glue and a laser infrared barrier material, and the laser infrared barrier material is formed by compounding a phthalocyanine compound and modified cesium tungsten bronze nanoparticles. According to the invention, the phthalocyanine compound is matched with the modified cesium tungsten bronze nano material, so that the ultra-wide and ultra-high barrier effect on 780-2500nm infrared light can be realized; the protective film has strong adaptability and broadband protection capability, and can cope with laser eavesdropping equipment of different wavebands.

Description

Technical Field

[0001] The invention relates to the technical field of laser eavesdropping protection, and in particular to a novel eavesdropping protection film and a preparation method thereof. Background Art

[0002] Among the many methods of stealing secrets, "laser eavesdropping" has become one of the main methods of stealing secrets due to its advantages of high concealment, long transmission distance, and wide applicability. Laser eavesdropping is achieved by emitting lasers that are invisible to the human eye, capturing and analyzing the vibrations of surrounding objects caused by the sound source, obtaining vibration information, and restoring the vibration information.

[0003] Among the existing laser eavesdropping protective film technologies, there are solutions that use a combination of multiple comprehensive infrared absorbers to achieve the effect of laser eavesdropping protection, targeting the main band of laser eavesdropping, 900-1800nm, but the combination of multiple absorbers is usually accompanied by agglomeration, and the near-infrared protection band is insufficient. There is also a solution that uses ITO materials with cesium tungsten bronze materials. Through the combination of the two coatings, a high infrared light blocking rate of 900-2500nm can be achieved. However, due to the shortcomings of the ITO material itself, such as certain brittleness, the use of the material is limited.

[0004] Many traditional materials have high shielding performance only in specific infrared bands (such as 780-1400nm or 1400-2500nm), but the shielding effect in other bands is poor, making it difficult to achieve full-spectrum shielding of infrared light. Many high-efficiency infrared shielding materials will significantly reduce visible light transmittance, thus affecting the transparency and application scenarios of the materials.

[0005] Some shielding materials require high loads to achieve the ideal shielding effect, which results in thick coatings and affects mechanical properties and processing performance. In addition, the dispersion and compatibility issues of different functional materials also restrict the performance of the materials. Summary of the invention

[0006] The purpose of the present invention is to provide a new type of eavesdropping protection film and a preparation method thereof, which utilizes phthalocyanine compounds in combination with modified cesium tungsten bronze nanomaterials to achieve ultra-wide and ultra-high blocking effects on 780-2500nm infrared light; the protective film has strong adaptability, and its wide-band protection capability can cope with laser eavesdropping equipment of different bands, thereby reducing the security risks caused by technological updates and iterations; at the same time, it has excellent scratch resistance and UV blocking protection performance, and the protective film has no difference in appearance from ordinary films, cannot be distinguished by the naked eye, does not affect the appearance, and ensures the concealment of privacy protection.

[0007] The above technical objectives of the present invention are achieved through the following technical solutions:

[0008] The present invention provides a novel eavesdropping protection film, which comprises in order: a scratch-resistant layer, a laser blocking protection layer, an anti-ultraviolet mounting adhesive layer and a release film;

[0009] Wherein, the laser blocking protective layer comprises a substrate layer and a laser infrared absorption layer, and the substrate layer is in contact with the scratch-resistant layer and the anti-ultraviolet mounting adhesive layer respectively;

[0010] The laser infrared absorption layer comprises glue and laser infrared blocking material, and the laser infrared blocking material is composed of a compound of phthalocyanine compounds and modified cesium tungsten copper nanoparticles.

[0011] The modified cesium tungsten bronze is modified by using a silane coupling agent.

[0012] Further, the scratch-resistant layer is prepared from the following components calculated by mass percentage:

[0013] Polyurethane resin 30-60%, toluene 20-50% and butanone 10-40%.

[0014] Furthermore, the anti-ultraviolet mounting adhesive layer is prepared from the following components calculated by mass percentage:

[0015] Acrylate adhesive 40-60%, curing agent 0.1-3%, UV absorber 0.1-5% and solvent A 40-60%.

[0016] Furthermore, according to the mass percentage, the addition amount of the phthalocyanine compound and the modified cesium tungsten copper nanoparticles is calculated by the following formula:

[0017]

[0018] Wherein, R is the mass ratio of the phthalocyanine compound to the modified cesium tungsten copper nanoparticles, and the unit is 1;

[0019] W1 represents the weight factor of phthalocyanine compounds, reflecting their contribution to near-infrared absorption, and the unit is 1;

[0020] W2 represents the weight factor of modified cesium tungsten bronze, reflecting its contribution to near-infrared shielding, and the unit is 1;

[0021] S NIR Characterizes the near-infrared light shielding rate in the wavelength range of 780-900nm, the unit is 1;

[0022] S IR Characterizes the near-infrared light shielding rate in the wavelength range of 900-2500nm, the unit is 1;

[0023] k1 is the absorption coefficient of phthalocyanine compounds to visible light;

[0024] α2 is the shielding efficiency coefficient of modified cesium tungsten bronze against near infrared.

[0025] Furthermore, calculated by mass percentage, the laser infrared blocking material includes the following components:

[0026] Acrylic adhesive 40-60%, curing agent 0.1-3%, ultraviolet absorber 0.1-10%, phthalocyanine compound and modified cesium tungsten bronze 1-50% and mixed solvent 40-60%.

[0027] Further, the mixed solvent includes toluene, methyl isobutyl ketone and ethyl acetate, and the volume ratio satisfies the following formula:

[0028]

[0029] Wherein, R is the mass ratio of phthalocyanine compound to modified cesium tungsten bronze, and the unit is 1;

[0030] S1 is the ability of toluene to dissolve phthalocyanine compounds, in g / mL;

[0031] S2 is the ability of methyl isobutyl ketone and ethyl acetate to synergistically disperse modified cesium tungsten bronze, the unit is g / mL;

[0032] γ is the ratio of methyl isobutyl ketone to ethyl acetate + methyl isobutyl ketone, the unit is 1;

[0033] V1 is the volume of toluene added, in L;

[0034] V2 is the volume of methyl isobutyl ketone added, in L

[0035] V3 is the volume of ethyl acetate added, in L.

[0036] Furthermore, the substrate layer and the release film are made of PET, PC, PVC, PE or PP.

[0037] Furthermore, the phthalocyanine compound is a metal phthalocyanine derivative, wherein the metal is selected from any one or more of copper, magnesium or zinc.

[0038] Furthermore, the particle size of the modified cesium tungsten bronze is 10-60 nm.

[0039] The present invention also provides a method for preparing a novel eavesdropping protection film, comprising the following steps:

[0040] A scratch-resistant layer is coated on one side of the substrate layer, and the scratch-resistant layer is obtained by UV curing;

[0041] The laser infrared blocking material is dispersed in a solvent, and an acrylic adhesive is added to form a mixed glue of a laser blocking protective layer;

[0042] Apply mixed glue on the other side of the substrate layer and laminate it with one side of the other substrate layer;

[0043] A layer of UV-resistant mounting adhesive layer is coated on the other side of the other substrate layer and laminated with a transparent release film.

[0044] In summary, the present invention has the following beneficial effects:

[0045] (1) The present invention provides a new type of eavesdropping protection film and its preparation method, which utilizes phthalocyanine compounds to have good light absorption characteristics in the near-infrared region of 700-900nm, and is matched with modified cesium tungsten bronze nanomaterials to achieve ultra-wide and ultra-high blocking effects for 780-2500nm infrared light. The protective film has strong adaptability, and its wide-band protection capability can cope with laser eavesdropping devices of different bands, reducing the security risks caused by technological updates and iterations.

[0046] (2) The present invention provides a new type of eavesdropping protection film and its preparation method. Through the combination of organic compounds and nanomaterials, it can achieve ultra-wide and ultra-high blocking effects on infrared light while having the characteristics of high definition and high light transmittance, ensuring the entry of normal light, and has excellent scratch resistance and UV blocking protection performance.

[0047] (3) The protective film preparation process provided by the present invention is simple and efficient, and its appearance is no different from that of ordinary films, which cannot be distinguished by the naked eye and does not affect the appearance, thereby ensuring the concealment of privacy protection. In addition, the construction environment takes into account both straight surfaces and curved surfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a schematic diagram of the structure of the laser eavesdropping protection film according to an embodiment of the present invention;

[0049] Figure 2 This is a schematic structural diagram of a laser blocking protective layer according to Example 1 of the present invention;

[0050] Figure 3 This is a schematic diagram of the structure of the laser blocking protective layer of Example 2 of the present invention.

[0051] Reference numerals

[0052] Scratch-resistant layer 1; laser blocking protective layer 2; UV protection mounting adhesive layer 3; release film layer 4; substrate layer 21; laser infrared absorption layer 22. DETAILED DESCRIPTION

[0053] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, an eavesdropping protection film and a preparation method thereof proposed according to the present invention, its specific implementation method, characteristics and effects are described in detail as follows.

[0054] The present specific embodiment provides a novel eavesdropping protection film, which comprises, in order: a scratch-resistant layer, a laser blocking protection layer, an anti-ultraviolet mounting adhesive layer and a release film;

[0055] Wherein, the laser blocking protective layer comprises a substrate layer and a laser infrared absorption layer, and the substrate layer is in contact with the scratch-resistant layer and the anti-ultraviolet mounting adhesive layer respectively;

[0056] The laser infrared absorption layer comprises glue and laser infrared blocking material, and the laser infrared blocking material is composed of a compound of phthalocyanine compounds and modified cesium tungsten bronze nanoparticles.

[0057] It is understandable that phthalocyanine compounds: phthalocyanine and its metal derivatives (such as copper phthalocyanine, magnesium phthalocyanine, etc.) have excellent near-infrared absorption capabilities, and their absorption peaks are located in the range of 700-900nm. At the same time, this type of compound exhibits a high transmittance in the visible light region and has good thermal and chemical stability, making it an ideal near-infrared shielding material.

[0058] Cesium tungsten bronze nanoparticles: Cesium tungsten bronze (Cs x WO3) is a new type of wide-spectrum infrared shielding material, which shows good infrared shielding efficiency in the range of 780-2500nm. Its shielding principle comes from the plasma resonance effect of cesium tungsten bronze, which can effectively reflect or absorb infrared light. Its transparency and stability are better than traditional metal oxide materials, and the modified cesium tungsten bronze will enhance the laser infrared shielding performance.

[0059] By combining phthalocyanine compounds with modified cesium tungsten bronze nanoparticles, full-band shielding of 780-2500nm infrared light can be achieved while maintaining high visible light transmittance. In order to achieve the synergistic effect of the two materials, the selection of the solvent system and its uniform distribution in the coating are also crucial. The optimized solvent system can solve the compatibility problem between materials and improve the stability and processability of coating preparation.

[0060] In some preferred embodiments, the laser blocking protective layer may include multiple substrate layers and laser infrared absorption layers, and the substrate layers and the laser infrared absorption layers are arranged at intervals, and the outermost substrate layers are in contact with the scratch-resistant layer and the anti-UV mounting adhesive layer respectively.

[0061] In some preferred embodiments, the scratch-resistant layer is prepared from the following components calculated by mass percentage:

[0062] Polyurethane resin 30-60%, toluene 20-50% and butanone 10-40%.

[0063] In some preferred embodiments, the anti-ultraviolet mounting adhesive layer is prepared from the following components calculated by mass percentage:

[0064] Acrylate adhesive 40-60%, curing agent 0.1-3%, UV absorber 0.1-5% and solvent A 40-60%.

[0065] In some preferred embodiments, the addition amount of the phthalocyanine compound and the modified cesium tungsten bronze nanoparticles is calculated by the following formula in terms of mass percentage:

[0066]

[0067] Wherein, R is the mass ratio of the phthalocyanine compound to the modified cesium tungsten bronze nanoparticles, and the unit is 1;

[0068] W1 represents the weight factor of phthalocyanine compounds, reflecting their contribution to near-infrared absorption, and the unit is 1;

[0069] W2 represents the weight factor of modified cesium tungsten bronze, reflecting its contribution to near-infrared shielding, and the unit is 1;

[0070] S NIR Characterizes the near-infrared light shielding rate in the wavelength range of 780-900nm, the unit is 1;

[0071] S IR Characterizes the near-infrared light shielding rate in the wavelength range of 900-2500nm, the unit is 1;

[0072] k1 is the absorption coefficient of phthalocyanine compounds to visible light;

[0073] α2 is the shielding efficiency coefficient of modified cesium tungsten bronze against near infrared.

[0074] It can be understood that the derivation process of the formula provided in this specific implementation is as follows:

[0075] In order to achieve high visible light transmittance and high infrared shielding rate, that is, to maximize the visible light transmittance T vis , while maintaining the infrared shielding rate S NIR and S IR At a higher level.

[0076] maxT vis Satisfy S NIR ≥S NIR,min ,S IR ≥S IR,min ;

[0077] Among them, S NIR,min and S IR,min is the minimum shielding rate threshold;

[0078] Visible light transmittance model:

[0079] T vis =T baseexp(-k1·C1-k2·C2)

[0080] Wherein, k1 is the absorption coefficient of phthalocyanine compounds to visible light, and the unit is 1;

[0081] k2 is the absorption coefficient of modified cesium tungsten bronze to visible light, and its unit is 1;

[0082] C1 is the amount of phthalocyanine compound added, in g;

[0083] C2 is the amount of modified cesium tungsten bronze added, the unit is g.

[0084] Near infrared shielding rate model:

[0085] S NIR =1-exp(-W1·C1-W2·C2)

[0086] Among them, W1 represents the weight factor of phthalocyanine compounds, reflecting their contribution to near-infrared absorption, and the unit is 1;

[0087] W2 characterizes the weight factor of modified cesium tungsten bronze, reflecting its contribution to near-infrared shielding, and the unit is 1.

[0088] Near infrared shielding rate model:

[0089] S IR =1-exp(-α2·C2)

[0090] Among them, α1 is the shielding efficiency coefficient of modified cesium tungsten bronze against near infrared.

[0091] Then, R is: R = C1 / C2; that is

[0092] The formula provided in this specific embodiment provides effective shielding for near infrared light (780-900nm) and near infrared light (900-2500nm) respectively by precisely controlling the mass ratio of the phthalocyanine compound to the modified cesium tungsten bronze.

[0093] Phthalocyanine compounds (such as copper phthalocyanine) have strong absorption characteristics in the near-infrared band of 780 to 900 nm, and can effectively absorb infrared laser light and prevent the laser from penetrating the material. This material property is quantified by the weight factor W1, which determines the contribution of phthalocyanine compounds in this band.

[0094] Modified cesium tungsten bronze nanoparticles (Cs x WO3) has a strong infrared light shielding ability in the near-infrared band of 900-2500nm, and is particularly suitable for shielding high-energy near-infrared lasers. Its shielding efficiency is described by α2 and weight factor W2, and it can provide effective optical protection in this band.

[0095] By optimizing the mass ratio R of phthalocyanine compounds and modified cesium tungsten bronze, the absorption and shielding effects of each material in its specific band are ensured to be optimal, thereby achieving efficient protection against full-band infrared light.

[0096] It should be pointed out that the weighting factor is generally a quantitative estimate based on the light absorption capacity and optical shielding efficiency of the material in a specific spectral range. The specific steps are as follows:

[0097] Step 1: Calculate the optical performance contribution of each material

[0098] For each material, its contribution to the optical performance can be quantified by its absorption coefficient or shielding efficiency coefficient over a specified wavelength range.

[0099] Contribution of phthalocyanine compounds (near-infrared light absorption): Calculate their near-infrared absorption capacity (for example, the absorption coefficient k1 of near-infrared light). For phthalocyanine compounds, the larger the k1 value, the stronger their light absorption capacity in the near-infrared range, so the weight factor W1 will be higher.

[0100] Contribution of modified cesium tungsten bronze (near-infrared shielding): Calculate its near-infrared light shielding ability (for example, shielding efficiency coefficient α2). For modified cesium tungsten bronze, the larger the α2 value, the stronger its shielding ability against near-infrared light, so the weight factor W2 will be higher.

[0101] In some preferred embodiments, the laser infrared blocking material comprises the following components calculated by mass percentage:

[0102] Acrylic adhesive 40-60%, curing agent 0.1-3%, ultraviolet absorber 0.1-10%, phthalocyanine compound and modified cesium tungsten bronze 1-50% and mixed solvent 40-60%.

[0103] In some preferred embodiments, the mixed solvent includes toluene, methyl isobutyl ketone and ethyl acetate, and the volume ratio satisfies the following formula:

[0104]

[0105] Wherein, R is the mass ratio of phthalocyanine compound to modified cesium tungsten bronze, and the unit is 1;

[0106] S1 is the ability of toluene to dissolve phthalocyanine compounds, in g / mL;

[0107] S2 is the ability of methyl isobutyl ketone and ethyl acetate to synergistically disperse modified cesium tungsten bronze, the unit is g / mL;

[0108] γ is the ratio of methyl isobutyl ketone to ethyl acetate + methyl isobutyl ketone, the unit is 1;

[0109] V1 is the volume of toluene added, in L;

[0110] V2 is the volume of methyl isobutyl ketone added, in L

[0111] V3 is the volume of ethyl acetate added, in L.

[0112] It can be understood that the derivation process of the above formula is as follows:

[0113] Assume that the total volume of the mixed solvent is V, and the solvent includes:

[0114] Toluene (V1): mainly dissolves phthalocyanine compounds;

[0115] Methyl isobutyl ketone (MIBK, V2): used to balance polarity and improve solubility;

[0116] Ethyl Acetate (V3): Disperse and modify cesium tungsten bronze and adjust the miscibility.

[0117] Dissolution requirements of phthalocyanine compounds:

[0118] The ability of toluene to dissolve phthalocyanine compounds is S1 (unit: g / mL), so the required volume of toluene is:

[0119]

[0120] Dispersion requirements of modified cesium tungsten bronze:

[0121] The synergistic effect of ethyl acetate and methyl isobutyl ketone in dissolving the modified cesium tungsten bronze is S2 (unit: g / mL), then the total volume of ethyl acetate and methyl isobutyl ketone is:

[0122]

[0123] Distribute V4 to methyl isobutyl ketone and ethyl acetate in the following proportions:

[0124] V2=γ · V4, V3 = (1-γ) · V4;

[0125] but,

[0126] In this specific embodiment, toluene has a relatively low polarity and is suitable for dissolving phthalocyanine compounds. It can be used as the main solvent in the mixed solvent system to improve the dissolution efficiency of phthalocyanine compounds. Methyl isobutyl ketone (MIBK) has a medium polarity and can form good miscibility with toluene, has good dispersibility for modified cesium tungsten bronze particles, and improves the viscosity control ability of the system. Ethyl acetate has a relatively high polarity and is suitable for adjusting the overall polarity of the solvent system, which helps to improve the miscibility uniformity of phthalocyanine compounds and modified cesium tungsten bronze and prevent phase separation.

[0127] The formula ensures the best distribution of the two materials (phthalocyanine compounds and modified cesium tungsten bronze) in the solvent by accurately calculating the ratio of toluene and MIBK + ethyl acetate mixed solvent. Phthalocyanine compounds need to be dissolved in toluene, so the volume of toluene needs to be calculated based on the amount of phthalocyanine compounds (C1) and the solubility of toluene (S1). The modified cesium tungsten bronze needs to be dispersed through the synergistic effect of MIBK and ethyl acetate, and the distribution of this part of the solvent volume (V2 and V3) is calculated based on the amount of modified cesium tungsten bronze (C2) and the synergistic solubility (S2). Through these calculations, the volume of each solvent can be accurately obtained, so that the solvent ratio can meet the dissolution requirements and ensure dispersibility. Through the solvent ratio calculation provided by the above formula, the amount of toluene, methyl isobutyl ketone (MIBK), and ethyl acetate added can be accurately adjusted according to the mass ratio R of phthalocyanine compounds and modified cesium tungsten bronze, thereby ensuring the best dissolution and dispersion effect at the minimum solvent volume. By adjusting the volume ratio of each solvent, the phthalocyanine compounds can be fully dissolved in toluene to meet the requirements of near-infrared light absorption; under the synergistic effect of methyl isobutyl ketone and ethyl acetate, the modified cesium tungsten bronze nanoparticles are effectively dispersed to ensure their uniform dispersion and avoid particle agglomeration.

[0128] It should be pointed out that the solvency is actually equivalent to solubility, which is defined as: S tol =Solubility = m max / V solvent ;

[0129] in:

[0130] S tol : Solubility of solvent in solute (unit: g / mL);

[0131] m max : The maximum solubility mass of the solvent in the solvent (unit: g);

[0132] V solvent : The volume of the solvent (unit: mL).

[0133] In some preferred embodiments, the substrate layer and the release film are made of PET, PC, PVC, PE or PP.

[0134] In some preferred embodiments, the phthalocyanine compound is a metal phthalocyanine derivative, wherein the metal is selected from any one or more of copper, magnesium or zinc.

[0135] In some preferred embodiments, the particle size of the modified cesium tungsten bronze is 10-60 nm.

[0136] In some preferred embodiments, the thickness of the scratch-resistant layer is 0.1-10 μm, the thickness of the UV protection adhesive layer is 1-3 μm, the thickness of the release film and the substrate layer is 10-100 μm, and the thickness of the laser blocking protective layer is 5-30 μm.

[0137] This specific embodiment also provides a method for preparing a novel eavesdropping protection film, comprising the following steps:

[0138] S1, coating a scratch-resistant layer material on one side of the substrate layer, and curing the scratch-resistant layer by UV light;

[0139] S2, dispersing the laser infrared blocking material in a solvent, and adding an acrylic adhesive to form a mixed glue of a laser blocking protective layer;

[0140] S3, coating the mixed glue on the other side of the substrate layer and compounding it with one side of the other substrate layer;

[0141] S4. Coat a layer of UV-resistant mounting adhesive layer on the other side of the other substrate layer and laminate it with a transparent release film.

[0142] In some preferred embodiments, the specific operations of step S2 are as follows:

[0143] First, mix toluene and MIBK and stir until uniform;

[0144] Then slowly add ethyl acetate and continue stirring to ensure that the three are completely miscible;

[0145] The phthalocyanine compound is first dissolved in the mixed solvent and stirred until completely dissolved;

[0146] Then, the modified cesium tungsten bronze nanoparticles are gradually added and evenly distributed through ultrasonic or high-speed dispersion treatment.

[0147] Through the above proportion adjustment and operation, the solubility of phthalocyanine compounds and the dispersion of modified cesium tungsten bronze can be effectively balanced to ensure that the optical properties and coating quality of the final material are in the best state.

[0148] The present invention will be further described below in conjunction with specific embodiments.

[0149] Example 1

[0150] This embodiment 1 provides a new type of eavesdropping protection film, such as Figure 1 As shown, the order is scratch-resistant layer 1, laser blocking protective layer 2, UV protection mounting adhesive layer 3 and release film layer 4.

[0151] The laser blocking protective layer 2 has the following structural components: substrate layer 21, laser infrared absorption layer 22 and substrate layer 21;

[0152] The scratch-resistant layer 1 is composed of 45% polyurethane resin, 30% toluene and 5% butanone in terms of mass percentage, and the thickness of the scratch-resistant layer 1 is 5 μm;

[0153] The anti-ultraviolet installation adhesive layer 3 is composed of the following components in terms of mass percentage: 48% acrylate adhesive, 1% curing agent, 1% ultraviolet absorber and 50% toluene. The thickness of the anti-ultraviolet installation adhesive layer 3 is 8 μm.

[0154] The material of the substrate layer 21 and the release film 4 is high-definition PET, and the thickness of the substrate layer 21 is 23 μm;

[0155] The laser infrared absorption layer 22 is composed of the following components by mass percentage: 46% acrylate adhesive, 1% curing agent, 1% UV absorber, 3.3% copper phthalocyanine and modified cesium tungsten bronze, and 48.7% mixed solvent. The coating thickness of the laser infrared absorption layer 22 is 10 μm.

[0156] Among them, the addition ratio of copper phthalocyanine and modified cesium tungsten bronze is calculated according to the following formula:

[0157]

[0158] Wherein, R is the mass ratio of copper phthalocyanine and modified cesium tungsten bronze nanoparticles, and the unit is 1;

[0159] W1 represents the weight factor of copper phthalocyanine, reflecting its contribution to near-infrared absorption, with a unit of 1 and a value of 0.1;

[0160] W2 represents the weight factor of modified cesium tungsten bronze, reflecting its contribution to near-infrared shielding, the unit is 1, and the value is 0.9;

[0161] S NIR Characterizes the near-infrared light shielding rate in the wavelength range of 780-900nm, the unit is 1, and the value is 0.85;

[0162] S IR Characterizes the near-infrared light shielding rate in the wavelength range of 900-2500nm, the unit is 1, and the value is 0.90;

[0163] k1 is the absorption coefficient of copper phthalocyanine to visible light, which is 0.3;

[0164] α2 is the shielding efficiency coefficient of modified cesium tungsten bronze to near infrared, and its value is 1.2.

[0165] According to calculation, R=0.33.

[0166] The mixed solvent includes toluene, methyl isobutyl ketone and ethyl acetate, and the volume ratio satisfies the following formula:

[0167]

[0168] Wherein, R is the mass ratio of copper phthalocyanine to modified cesium tungsten bronze, and the unit is 1;

[0169] S1 is the ability of toluene to dissolve copper phthalocyanine, the unit is g / mL, and the value is 0.02;

[0170] S2 is the ability of methyl isobutyl ketone and ethyl acetate to synergistically disperse modified cesium tungsten bronze, the unit is g / mL, and the value is 0.05;

[0171] γ is the ratio of methyl isobutyl ketone to ethyl acetate + methyl isobutyl ketone, the unit is 1, and the value is 0.6;

[0172] V1 is the added volume of toluene, in L;

[0173] V2 is the volume of methyl isobutyl ketone added, in L

[0174] V3 is the volume of ethyl acetate added, in L.

[0175] Calculation shows that the volume ratio of toluene, methyl isobutyl ketone and ethyl acetate is 16.5:12:8.

[0176] A method for making a novel eavesdropping protection film in this embodiment 1 is as follows:

[0177] S1, coating a scratch-resistant layer 1 on one side of the substrate layer 21, and curing by UV light;

[0178] S2, dispersing the laser infrared blocking material in a solvent, and adding an acrylic adhesive to form the laser infrared absorption layer 22;

[0179] S3 , coating a layer of laser infrared absorption layer 22 material on the other side of the substrate layer 21 and compounding it with one side of the second substrate layer 21 .

[0180] S4 , coating a layer of UV protection mounting adhesive layer 3 on the other side of the second substrate layer 21 , and compounding it with a transparent release film 4 .

[0181] The specific operation of step S2 is as follows:

[0182] First, mix toluene and MIBK and stir until uniform;

[0183] Then slowly add ethyl acetate and continue stirring to ensure that the three are completely miscible;

[0184] Copper phthalocyanine is first dissolved in the mixed solvent and stirred until completely dissolved;

[0185] Then, the modified cesium tungsten bronze nanoparticles are gradually added and evenly distributed through ultrasonic or high-speed dispersion treatment.

[0186] Example 2

[0187] This embodiment 2 provides a new type of eavesdropping protection film, such as Figure 1 As shown, the order is scratch-resistant layer 1, laser blocking protective layer 2, UV protection mounting adhesive layer 3 and release film layer 4.

[0188] Among them, the laser blocking protective layer 2 is as follows Figure 3 As shown, the structural composition order is: substrate layer 21, laser infrared absorption layer 22, substrate layer 21, laser infrared absorption layer 22 and substrate layer 21;

[0189] The scratch-resistant layer 1 is composed of 45% polyurethane resin, 30% toluene and 5% butanone in terms of mass percentage, and the thickness of the scratch-resistant layer 1 is 5 μm;

[0190] The anti-ultraviolet installation adhesive layer 3 is composed of the following components in terms of mass percentage: 48% acrylate adhesive, 1% curing agent, 1% ultraviolet absorber and 50% toluene. The thickness of the anti-ultraviolet installation adhesive layer 3 is 8 μm.

[0191] The material of the substrate layer 21 and the release film 4 is high-definition PET, and the thickness of the substrate layer 21 is 23 μm;

[0192] The laser infrared absorption layer 22 is composed of the following components by mass percentage: 46% acrylate adhesive, 1% curing agent, 1% UV absorber, 4.0% copper phthalocyanine and modified cesium tungsten bronze, and 48% mixed solvent. The coating thickness of the laser infrared absorption layer 22 is 10 μm.

[0193] Among them, the addition ratio of copper phthalocyanine and modified cesium tungsten bronze is calculated according to the following formula:

[0194]

[0195] Wherein, R is the mass ratio of copper phthalocyanine and modified cesium tungsten bronze nanoparticles, and the unit is 1;

[0196] W1 represents the weight factor of copper phthalocyanine, reflecting its contribution to near-infrared absorption, with a unit of 1 and a value of 0.2;

[0197] W2 represents the weight factor of modified cesium tungsten bronze, reflecting its contribution to near-infrared shielding, the unit is 1, and the value is 0.8;

[0198] S NIR Characterizes the near-infrared light shielding rate in the wavelength range of 780-900nm, the unit is 1, and the value is 0.85;

[0199] S IR Characterizes the near-infrared light shielding rate in the wavelength range of 900-2500nm, the unit is 1, and the value is 0.90;

[0200] k1 is the absorption coefficient of copper phthalocyanine to visible light, which is 0.3;

[0201] α2 is the shielding efficiency coefficient of modified cesium tungsten bronze to near infrared, and its value is 1.2.

[0202] According to calculation, R=0.74.

[0203] The mixed solvent includes toluene, methyl isobutyl ketone and ethyl acetate, and the volume ratio satisfies the following formula:

[0204]

[0205] Wherein, R is the mass ratio of copper phthalocyanine to modified cesium tungsten bronze, and the unit is 1;

[0206] S1 is the ability of toluene to dissolve copper phthalocyanine, the unit is g / mL, and the value is 0.02;

[0207] S2 is the ability of methyl isobutyl ketone and ethyl acetate to synergistically disperse modified cesium tungsten bronze, the unit is g / mL, and the value is 0.05;

[0208] γ is the ratio of methyl isobutyl ketone to ethyl acetate + methyl isobutyl ketone, the unit is 1, and the value is 0.7;

[0209] V1 is the added volume of toluene, in L;

[0210] V2 is the volume of methyl isobutyl ketone added, in L

[0211] V3 is the volume of ethyl acetate added, in L.

[0212] Calculation shows that the volume ratio of toluene, methyl isobutyl ketone and ethyl acetate is 37:14:6.

[0213] A method for making a novel eavesdropping protection film in this embodiment 2 is as follows:

[0214] S1, coating a scratch-resistant layer 1 on one side of the substrate layer 21, and curing by UV light;

[0215] S2, dispersing the laser infrared blocking material in a solvent, and adding an acrylic adhesive to form the laser infrared absorption layer 22;

[0216] S3, coating the material of the laser infrared absorption layer 22 on the other side of the substrate layer 21 according to the structure of substrate layer 21 / laser infrared absorption layer 22 / substrate layer 21 / laser infrared absorption layer 22 / substrate layer 21;

[0217] S4 , coating a layer of UV protection mounting adhesive layer 3 on the other side of the substrate layer 21 and compounding it with the transparent release film 4 .

[0218] The specific operation of step S2 is as follows:

[0219] First, mix toluene and MIBK and stir until uniform;

[0220] Then slowly add ethyl acetate and continue stirring to ensure that the three are completely miscible;

[0221] Copper phthalocyanine is first dissolved in the mixed solvent and stirred until completely dissolved;

[0222] Then, the modified cesium tungsten bronze nanoparticles are gradually added and evenly distributed through ultrasonic or high-speed dispersion treatment.

[0223] Comparative Example 1

[0224] This comparative example 1 provides a novel eavesdropping protection film and a preparation method thereof, such as Figure 1 As shown, the order is scratch-resistant layer 1, laser blocking protective layer 2, UV protection mounting adhesive layer 3 and release film layer 4.

[0225] The laser blocking protective layer 2 has the following structural components: substrate layer 21, laser infrared absorption layer 22 and substrate layer 21;

[0226] The scratch-resistant layer 1 is composed of 45% polyurethane resin, 30% toluene and 5% butanone in terms of mass percentage, and the thickness of the scratch-resistant layer 1 is 5 μm;

[0227] The anti-ultraviolet installation adhesive layer 3 is composed of the following components in terms of mass percentage: 48% acrylate adhesive, 1% curing agent, 1% ultraviolet absorber and 50% toluene. The thickness of the anti-ultraviolet installation adhesive layer 3 is 8 μm.

[0228] The material of the substrate layer 21 and the release film 4 is high-definition PET, and the thickness of the substrate layer 21 is 23 μm;

[0229] The laser infrared absorption layer 22 is composed of the following components by mass percentage: 46% acrylate adhesive, 1% curing agent, 1% UV absorber, 3.3% copper phthalocyanine and modified cesium tungsten bronze, and 48.7% mixed solvent. The coating thickness of the laser infrared absorption layer 22 is 10 μm.

[0230] Among them, the addition ratio of copper phthalocyanine and modified cesium tungsten bronze is calculated according to the following formula:

[0231]

[0232] Wherein, R is the mass ratio of copper phthalocyanine and modified cesium tungsten bronze nanoparticles, and the unit is 1;

[0233] W1 represents the weight factor of copper phthalocyanine, reflecting its contribution to near-infrared absorption, with a unit of 1 and a value of 0.1;

[0234] W2 represents the weight factor of modified cesium tungsten bronze, reflecting its contribution to near-infrared shielding, the unit is 1, and the value is 0.9;

[0235] S NIR Characterizes the near-infrared light shielding rate in the wavelength range of 780-900nm, the unit is 1, and the value is 0.85;

[0236] S IR Characterizes the near-infrared light shielding rate in the wavelength range of 900-2500nm, the unit is 1, and the value is 0.90;

[0237] k1 is the absorption coefficient of copper phthalocyanine to visible light, which is 0.3;

[0238] α2 is the shielding efficiency coefficient of modified cesium tungsten bronze to near infrared, and its value is 1.2.

[0239] According to calculation, R=0.33.

[0240] The mixed solvent includes toluene, methyl isobutyl ketone and ethyl acetate, and the volume ratio satisfies the following formula:

[0241]

[0242] Wherein, R is the mass ratio of copper phthalocyanine to modified cesium tungsten bronze, and the unit is 1;

[0243] S1 is the ability of toluene to dissolve copper phthalocyanine, the unit is g / mL, and the value is 0.02;

[0244] S2 is the ability of methyl isobutyl ketone and ethyl acetate to synergistically disperse modified cesium tungsten bronze, the unit is g / mL, and the value is 0.05;

[0245] γ is the ratio of methyl isobutyl ketone to ethyl acetate + methyl isobutyl ketone, the unit is 1, and the value is 0.6;

[0246] V1 is the added volume of toluene, in L;

[0247] V2 is the volume of methyl isobutyl ketone added, in L

[0248] V3 is the volume of ethyl acetate added, in L.

[0249] Calculation shows that the volume ratio of toluene, methyl isobutyl ketone and ethyl acetate is 16.5:12:8.

[0250] A method for preparing a novel eavesdropping protection film in this comparative example 1 is as follows:

[0251] S1, coating a scratch-resistant layer 1 on one side of the substrate layer 21, and curing by UV light;

[0252] S2, dispersing the laser infrared blocking material in a solvent, and adding an acrylic adhesive to form the laser infrared absorption layer 22;

[0253] S3 , coating a layer of laser infrared absorption layer 22 material on the other side of the substrate layer 21 and compounding it with one side of the second substrate layer 21 .

[0254] S4 , coating a layer of UV protection mounting adhesive layer 3 on the other side of the second substrate layer 21 , and compounding it with a transparent release film 4 .

[0255] The specific operation of step S2 is as follows:

[0256] First, mix toluene, MIBK and ethyl acetate and stir until uniform;

[0257] Copper phthalocyanine and modified cesium tungsten bronze nanoparticles are added into a mixed solvent and uniformly distributed by ultrasonic treatment.

[0258] Comparative Example 2

[0259] This comparative example 2 provides a new type of eavesdropping protection film, such as Figure 1 As shown, the order is scratch-resistant layer 1, laser blocking protective layer 2, UV protection mounting adhesive layer 3 and release film layer 4.

[0260] The laser blocking protective layer 2 has the following structural components: substrate layer 21, laser infrared absorption layer 22 and substrate layer 21;

[0261] The scratch-resistant layer 1 is composed of 45% polyurethane resin, 30% toluene and 5% butanone in terms of mass percentage, and the thickness of the scratch-resistant layer 1 is 5 μm;

[0262] The anti-ultraviolet installation adhesive layer 3 is composed of the following components in terms of mass percentage: 48% acrylate adhesive, 1% curing agent, 1% ultraviolet absorber and 50% toluene. The thickness of the anti-ultraviolet installation adhesive layer 3 is 8 μm.

[0263] The material of the substrate layer 21 and the release film 4 is high-definition PET, and the thickness of the substrate layer 21 is 23 μm;

[0264] The laser infrared absorption layer 22 is composed of the following components by mass percentage: 46% acrylate adhesive, 1% curing agent, 1% UV absorber, 2% copper phthalocyanine, 1.3% modified cesium tungsten bronze and 48.7% mixed solvent. The coating thickness of the laser infrared absorption layer 22 is 10 μm.

[0265] The mixed solvent includes toluene, methyl isobutyl ketone and ethyl acetate, and the volume ratio satisfies the following formula:

[0266]

[0267] Wherein, R is the mass ratio of copper phthalocyanine to modified cesium tungsten bronze, and the unit is 1;

[0268] S1 is the ability of toluene to dissolve copper phthalocyanine, the unit is g / mL, and the value is 0.02;

[0269] S2 is the ability of methyl isobutyl ketone and ethyl acetate to synergistically disperse modified cesium tungsten bronze, the unit is g / mL, and the value is 0.05;

[0270] γ is the ratio of methyl isobutyl ketone to ethyl acetate + methyl isobutyl ketone, the unit is 1, and the value is 0.6;

[0271] V1 is the added volume of toluene, in L;

[0272] V2 is the volume of methyl isobutyl ketone added, in L

[0273] V3 is the volume of ethyl acetate added, in L.

[0274] Calculation shows that the volume ratio of toluene, methyl isobutyl ketone and ethyl acetate is 76.9:12:8.

[0275] A method for preparing a novel eavesdropping protection film in this comparative example 2 is as follows:

[0276] S1, coating a scratch-resistant layer 1 on one side of the substrate layer 21, and curing by UV light;

[0277] S2, dispersing the laser infrared blocking material in a solvent, and adding an acrylic adhesive to form the laser infrared absorption layer 22;

[0278] S3 , coating a layer of laser infrared absorption layer 22 material on the other side of the substrate layer 21 and compounding it with one side of the second substrate layer 21 .

[0279] S4 , coating a layer of UV protection mounting adhesive layer 3 on the other side of the second substrate layer 21 , and compounding it with a transparent release film 4 .

[0280] The specific operation of step S2 is as follows:

[0281] First, mix toluene and MIBK and stir until uniform;

[0282] Then slowly add ethyl acetate and continue stirring to ensure that the three are completely miscible;

[0283] Copper phthalocyanine is first dissolved in the mixed solvent and stirred until completely dissolved;

[0284] Then, the modified cesium tungsten bronze nanoparticles are gradually added and evenly distributed through ultrasonic or high-speed dispersion treatment.

[0285] Comparative Example 3

[0286] This comparative example 3 provides a new type of eavesdropping protection film, such as Figure 1 As shown, the order is scratch-resistant layer 1, laser blocking protective layer 2, UV protection mounting adhesive layer 3 and release film layer 4.

[0287] The laser blocking protective layer 2 has the following structural components: substrate layer 21, laser infrared absorption layer 22 and substrate layer 21;

[0288] The scratch-resistant layer 1 is composed of 45% polyurethane resin, 30% toluene and 5% butanone in terms of mass percentage, and the thickness of the scratch-resistant layer 1 is 5 μm;

[0289] The anti-ultraviolet installation adhesive layer 3 is composed of the following components in terms of mass percentage: 48% acrylate adhesive, 1% curing agent, 1% ultraviolet absorber and 50% toluene. The thickness of the anti-ultraviolet installation adhesive layer 3 is 8 μm.

[0290] The material of the substrate layer 21 and the release film 4 is high-definition PET, and the thickness of the substrate layer 21 is 23 μm;

[0291] The laser infrared absorption layer 22 is composed of the following components by mass percentage: 46% acrylate adhesive, 1% curing agent, 1% UV absorber, 0.1% copper phthalocyanine, 3.2% modified cesium tungsten bronze and 48.7% mixed solvent. The coating thickness of the laser infrared absorption layer 22 is 10 μm.

[0292] The mixed solvent includes toluene, methyl isobutyl ketone and ethyl acetate, and the volume ratio satisfies the following formula:

[0293]

[0294] Wherein, R is the mass ratio of copper phthalocyanine to modified cesium tungsten bronze, and the unit is 1;

[0295] S1 is the ability of toluene to dissolve copper phthalocyanine, the unit is g / mL, and the value is 0.02;

[0296] S2 is the ability of methyl isobutyl ketone and ethyl acetate to synergistically disperse modified cesium tungsten bronze, the unit is g / mL, and the value is 0.05;

[0297] γ is the ratio of methyl isobutyl ketone to ethyl acetate + methyl isobutyl ketone, the unit is 1, and the value is 0.6;

[0298] V1 is the added volume of toluene, in L;

[0299] V2 is the volume of methyl isobutyl ketone added, in L

[0300] V3 is the volume of ethyl acetate added, in L.

[0301] Calculation shows that the volume ratio of toluene, methyl isobutyl ketone and ethyl acetate is 1.57:12:8.

[0302] A method for preparing a novel eavesdropping protection film in this comparative example 3 is as follows:

[0303] S1, coating a scratch-resistant layer 1 on one side of the substrate layer 21, and curing by UV light;

[0304] S2, dispersing the laser infrared blocking material in a solvent, and adding an acrylic adhesive to form the laser infrared absorption layer 22;

[0305] S3 , coating a layer of laser infrared absorption layer 22 material on the other side of the substrate layer 21 and compounding it with one side of the second substrate layer 21 .

[0306] S4 , coating a layer of UV protection mounting adhesive layer 3 on the other side of the second substrate layer 21 , and compounding it with a transparent release film 4 .

[0307] The specific operation of step S2 is as follows:

[0308] First, mix toluene and MIBK and stir until uniform;

[0309] Then slowly add ethyl acetate and continue stirring to ensure that the three are completely miscible;

[0310] Copper phthalocyanine is first dissolved in the mixed solvent and stirred until completely dissolved;

[0311] Then, the modified cesium tungsten bronze nanoparticles are gradually added and evenly distributed through ultrasonic or high-speed dispersion treatment.

[0312] Comparative Example 4

[0313] This comparative example 4 provides a new type of eavesdropping protection film, such as Figure 1 As shown, the order is scratch-resistant layer 1, laser blocking protective layer 2, UV protection mounting adhesive layer 3 and release film layer 4.

[0314] The laser blocking protective layer 2 has the following structural components: substrate layer 21, laser infrared absorption layer 22 and substrate layer 21;

[0315] The scratch-resistant layer 1 is composed of 45% polyurethane resin, 30% toluene and 5% butanone in terms of mass percentage, and the thickness of the scratch-resistant layer 1 is 5 μm;

[0316] The anti-ultraviolet installation adhesive layer 3 is composed of the following components in terms of mass percentage: 48% acrylate adhesive, 1% curing agent, 1% ultraviolet absorber and 50% toluene. The thickness of the anti-ultraviolet installation adhesive layer 3 is 8 μm.

[0317] The material of the substrate layer 21 and the release film 4 is high-definition PET, and the thickness of the substrate layer 21 is 23 μm;

[0318] The laser infrared absorption layer 22 is composed of the following components by mass percentage: 46% acrylate adhesive, 1% curing agent, 1% UV absorber, 3.3% copper phthalocyanine and modified cesium tungsten bronze, and 48.7% mixed solvent. The coating thickness of the laser infrared absorption layer 22 is 10 μm.

[0319] Among them, the addition ratio of copper phthalocyanine and modified cesium tungsten bronze is calculated according to the following formula:

[0320]

[0321] Wherein, R is the mass ratio of copper phthalocyanine and modified cesium tungsten bronze nanoparticles, and the unit is 1;

[0322] W1 represents the weight factor of copper phthalocyanine, reflecting its contribution to near-infrared absorption, with a unit of 1 and a value of 0.1;

[0323] W2 represents the weight factor of modified cesium tungsten bronze, reflecting its contribution to near-infrared shielding, the unit is 1, and the value is 0.9;

[0324] S NIR Characterizes the near-infrared light shielding rate in the wavelength range of 780-900nm, the unit is 1, and the value is 0.85;

[0325] S IR Characterizes the near-infrared light shielding rate in the wavelength range of 900-2500nm, the unit is 1, and the value is 0.90;

[0326] k1 is the absorption coefficient of copper phthalocyanine to visible light, which is 0.3;

[0327] α2 is the shielding efficiency coefficient of modified cesium tungsten bronze to near infrared, and its value is 1.2.

[0328] According to calculation, R=0.33.

[0329] The mixed solvent includes toluene, methyl isobutyl ketone and ethyl acetate, and the volume ratio satisfies 1:1:1.

[0330] A method for preparing a novel eavesdropping protection film in this comparative example 4 is as follows:

[0331] S1, coating a scratch-resistant layer 1 on one side of the substrate layer 21, and curing by UV light;

[0332] S2, dispersing the laser infrared blocking material in a solvent, and adding an acrylic adhesive to form the laser infrared absorption layer 22;

[0333] S3 , coating a layer of laser infrared absorption layer 22 material on the other side of the substrate layer 21 and compounding it with one side of the second substrate layer 21 .

[0334] S4 , coating a layer of UV protection mounting adhesive layer 3 on the other side of the second substrate layer 21 , and compounding it with a transparent release film 4 .

[0335] The specific operation of step S2 is as follows:

[0336] First, mix toluene and MIBK and stir until uniform;

[0337] Then slowly add ethyl acetate and continue stirring to ensure that the three are completely miscible;

[0338] Copper phthalocyanine is first dissolved in the mixed solvent and stirred until completely dissolved;

[0339] Then, the modified cesium tungsten bronze nanoparticles are gradually added and evenly distributed through ultrasonic or high-speed dispersion treatment.

[0340] Performance Testing

[0341] The spectral transmittance performance of the protective films prepared in Examples 1 to 2 and Comparative Examples 1 to 4 was tested using a spectrophotometer, and the test results are shown in the following table.

[0342]

[0343]

[0344]

[0345] According to the comparison of the results of Example 1 and Comparative Example 1, when copper phthalocyanine and modified cesium tungsten bronze are not added in batches, the dispersion is poor, which affects the spectral transmittance to a certain extent.

[0346] According to the comparison of the results of Example 1 with Comparative Examples 2 and 3, it can be seen that when the formula provided by the present invention is not used to accurately calculate the ratio of the addition amounts of copper phthalocyanine and modified cesium tungsten bronze, excessive or insufficient addition amounts of copper phthalocyanine will affect the spectral transmittance.

[0347] According to the comparison of the results of Example 1 and Comparative Example 4, when the volume ratio of each solvent in the mixed solvent is not calculated using the formula provided by the present invention, the dispersibility of copper phthalocyanine and modified cesium tungsten bronze is very poor, which has a serious impact on the spectral transmittance.

[0348] The above description is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been presented as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A new type of eavesdropping protection film, characterized in that: The sequence includes: Scratch-resistant layer, laser blocking protective layer, UV-resistant mounting adhesive layer and release film; Wherein, the laser blocking protective layer comprises a substrate layer and a laser infrared absorption layer, and the substrate layer is in contact with the scratch-resistant layer and the anti-ultraviolet mounting adhesive layer respectively; The laser infrared absorption layer comprises glue and laser infrared blocking material, and the laser infrared blocking material is composed of a compound of phthalocyanine compounds and modified cesium tungsten bronze nanoparticles; The modified cesium tungsten bronze is modified by using a silane coupling agent.

2. A novel eavesdropping protection film according to claim 1, characterized in that: The scratch-resistant layer is prepared from the following components calculated by mass percentage: Polyurethane resin 30-60%, toluene 20-50% and butanone 10-40%.

3. The novel eavesdropping protection film according to claim 1 is characterized in that: The anti-ultraviolet mounting adhesive layer is prepared from the following components calculated by mass percentage: Acrylic adhesive 40-60%, curing agent 0.1-3%, UV absorber 0.1-5% and solvent 40-60%.

4. The novel eavesdropping protection film according to claim 1 is characterized in that: Calculated by mass percentage, the addition amount of the phthalocyanine compound and the modified cesium tungsten bronze nanoparticles is calculated by the following formula: Wherein, R is the mass ratio of the phthalocyanine compound to the modified cesium tungsten copper nanoparticles, and the unit is 1; W1 represents the weight factor of phthalocyanine compounds, reflecting their contribution to near-infrared absorption, and the unit is 1; W2 represents the weight factor of modified cesium tungsten bronze, reflecting its contribution to near-infrared shielding, and the unit is 1; S NIR Characterizes the near-infrared light shielding rate in the wavelength range of 780-900nm, the unit is 1; S IR Characterizes the near-infrared light shielding rate in the wavelength range of 900-2500nm, the unit is 1; k1 is the absorption coefficient of phthalocyanine compounds to visible light; α2 is the shielding efficiency coefficient of modified cesium tungsten bronze against near infrared.

5. The novel eavesdropping protection film according to claim 4 is characterized in that: Calculated by mass percentage, the laser infrared blocking material includes the following components: Acrylic adhesive 40-60%, curing agent 0.1-3%, ultraviolet absorber 0.1-10%, phthalocyanine compound and modified cesium tungsten bronze 1-50% and mixed solvent 40-60%.

6. A novel eavesdropping protection film according to claim 5, characterized in that: The mixed solvent includes toluene, methyl isobutyl ketone and ethyl acetate, and the volume ratio satisfies the following formula: Wherein, R is the mass ratio of phthalocyanine compound to modified cesium tungsten bronze, and the unit is 1; S1 is the ability of toluene to dissolve phthalocyanine compounds, in g / mL; S2 is the ability of methyl isobutyl ketone and ethyl acetate to synergistically disperse modified cesium tungsten bronze, the unit is g / mL; γ is the ratio of methyl isobutyl ketone to ethyl acetate + methyl isobutyl ketone, the unit is 1; V1 is the added volume of toluene, in L; V2 is the volume of methyl isobutyl ketone added, in L V3 is the volume of ethyl acetate added, in L.

7. The novel eavesdropping protection film according to claim 1 is characterized in that: The material of the substrate layer and the release film is PET, PC, PVC, PE or PP.

8. The novel eavesdropping protection film according to claim 1 is characterized in that: The phthalocyanine compound is a metal phthalocyanine derivative, wherein the metal is selected from any one or more of copper, magnesium or zinc.

9. The novel eavesdropping protection film according to claim 1 is characterized in that: The particle size of the modified cesium tungsten bronze is 10-60 nm.

10. A method for preparing a novel eavesdropping protection film according to any one of claims 1 to 9, characterized in that: The steps include: A scratch-resistant layer is coated on one side of the substrate layer, and the scratch-resistant layer is obtained by UV curing; The laser infrared blocking material is dispersed in a solvent, and an acrylic adhesive is added to form a mixed glue of a laser blocking protective layer; Apply mixed glue on the other side of the substrate layer and laminate it with one side of the other substrate layer; A layer of UV-resistant mounting adhesive layer is coated on the other side of the other substrate layer and laminated with a transparent release film.

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