A laser-engravable anti-static polycarbonate film for identification cards and a method of making and using the same

Abstract

The present application belongs to the technical field of laser etching polycarbonate film, and particularly relates to a laser etching antistatic polycarbonate film for ID card, a preparation method and application thereof. The laser etching antistatic polycarbonate film for ID card comprises the following components in parts by mass: functional particles 1-20 parts, and base polyester 100 parts; the functional particles comprise the following components: laser sensitive agent 2-7 parts, antistatic agent 10-20 parts, and carrying agent 22-30 parts. The antistatic polycarbonate film prepared by the present application has antistatic function, can effectively reduce the dust adsorbed by the film, improve the production efficiency, and the image after laser etching is clear, color steps are rich, and no ink immersion and flash phenomenon occurs.

Description

Technical Field

[0001] This invention belongs to the field of laser etching polycarbonate film technology, specifically relating to an antistatic polycarbonate film that can be used for laser etching of ID cards, its preparation method, and its application. Background Technology

[0002] In the field of document manufacturing and personalization, laser etching (including laser ablation / reduction and etching) technology has become an important means of recording personalized information on high-security cards. Laser etching can create irreversible, wear-resistant, and tamper-proof patterns, which can be used to write data such as the cardholder's photo, personal information, micro-characters, and anti-counterfeiting patterns. It is often used in combination with various security features such as optical anti-counterfeiting ink, embedded chips, and holographic anti-counterfeiting to improve the document's resistance to tampering and forgery.

[0003] Meanwhile, with the increasing frequency of international circulation, higher performance requirements are being placed on card materials. Polycarbonate offers overall performance advantages over previous generations of card materials such as PVC and PETG, including high-quality laser etching performance, long lifespan, high temperature resistance, high impact resistance, bending resistance, and high adhesion. As a result, many governments and card manufacturers have adopted polycarbonate as the primary substrate for issuing long-term valid information security documents (such as ID cards, driver's licenses, passport data pages, and voter registration cards) and other personal information documents. Furthermore, the design of new-generation document structures has entered the era of multi-layered, all-polycarbonate structures, and laser etching has been introduced into the document manufacturing process as an essential means of personal information entry.

[0004] However, despite the unique advantages of laser-etched polycarbonate film materials in anti-counterfeiting and personal information entry, several key shortcomings still exist in actual production and long-term use. First, laser etching on polycarbonate films can produce etching defects such as "flash / ink splatter" and ink splatter (including rough edges of patterns, uneven carbonization, and color differences), resulting in reduced image or character clarity and affecting the generation and verification of optical anti-counterfeiting features. "Flash / ink splatter" refers to the phenomenon where, during laser etching of polycarbonate films, the polycarbonate at the edge of the etched area melts instantaneously due to heat but does not completely vaporize or dissipate in time. Under the influence of surface tension, cooling rate, or laser scanning trajectory, the molten material accumulates along the etching boundary and re-solidifies, forming microscale protrusions, ridges, or burr-like structures at the edge of the etched contour. "Ink immersion" refers to the phenomenon where, during the laser etching process of polycarbonate films, due to excessively high local laser energy density or incomplete thermal decomposition of the material, carbonized products, dust particles, or thermal decomposition residues generated in the etched area penetrate or adhere to the etched area and its surrounding substrate or microporous structure after etching. This results in graying or blackening of the etched pattern boundaries, decreased contrast, or contamination of transparent areas. Secondly, polycarbonate is an insulating material that easily generates and accumulates static electricity, especially during printing, lamination, laser etching, card cutting, and document use, where static charge accumulation is highly likely. Static charge accumulation can lead to the following problems: adsorption of dust and airborne particles, causing printing defects during the printing process; further, it can lead to contamination and defects in the etched area, reducing overall production yield; it can also cause lamination misalignment, unstable paper feeding, and misjudgments in online detection, affecting production stability and document reliability, reducing production efficiency and yield; electrostatic discharge may interfere with or damage the transmission signals of embedded RF chips, contact modules, or antennas during use.

[0005] To address the issue of static electricity, current methods typically employ surface antistatic coatings, antistatic inks, or external conductive layers. However, these methods suffer from poor durability, easy migration of antistatic agents, or attenuation of antistatic effects. More seriously, these methods can lead to insufficient bonding strength after polycarbonate lamination and reduce the quality of laser etching. Alternatively, adding conductive fillers, quaternary ammonium salt antistatic agents, or hydrophilic additives to the substrate can solve the static electricity problem, but this can result in issues such as decreased thermal stability, filler precipitation and atomization, attenuation and loss of antistatic effects, or incompatibility with laser-sensitive agent systems.

[0006] In summary, while laser-etched polycarbonate offers significant advantages in enhancing the anti-counterfeiting capabilities of security cards, it still faces pressing challenges in addressing two key aspects: laser etching quality and antistatic properties. Therefore, developing a polycarbonate card material that combines antistatic properties with high-quality laser etching has significant engineering value and promising industrial application prospects for improving the stability of industrialized document manufacturing processes (such as production efficiency and yield, and the safety and reliability of laser etching). Summary of the Invention

[0007] The purpose of this invention is to provide an antistatic polycarbonate film for laser etching of identification cards, its preparation method, and its application. The polycarbonate film prepared by this invention has antistatic properties, which can effectively reduce the dust adsorbed on the film and improve production efficiency; the image after laser etching is clear, with rich color gradation, and no ink bleed or flash.

[0008] To achieve the above objectives, the present invention provides the following technical solution: An antistatic polycarbonate film for laser etching of ID cards, comprising, by weight, the following components: 1-20 parts of functional particles and 100 parts of polyester matrix.

[0009] Preferably, by mass, the functional particles comprise the following components: 2-7 parts laser sensitizer, 10-20 parts antistatic agent, and 22-30 parts carrier.

[0010] Preferably, the functional particles, by mass, comprise the following components: 5 parts laser sensitizer, 15 parts antistatic agent, and 25 parts carrier agent.

[0011] Preferably, the base polyester is polycarbonate, and the polycarbonate comprises polycarbonate A, polycarbonate B and polycarbonate C in a mass ratio of (1.2-1.4):1:(0.3-0.5).

[0012] Preferably, under test conditions of 300°C / 1.2kg, the melt flow rate of polycarbonate A is 14-16 g / 10min; the melt flow rate of polycarbonate B is 8-11 g / 10min; and the melt flow rate of polycarbonate C is 20-23 g / 10min.

[0013] Preferably, under test conditions of 300°C / 1.2kg, the melt flow rate of polycarbonate A is 15g / 10min; the melt flow rate of polycarbonate B is 10g / 10min; and the melt flow rate of polycarbonate C is 22g / 10min.

[0014] This invention combines three polycarbonates with different melt flow rates in a mass ratio of (1.2-1.4):1:(0.3-0.5). The three compounds synergistically form a melt system with a wide molecular weight distribution, which not only significantly improves the extrusion quality and thickness uniformity of the film, but more importantly, provides an excellent matrix environment with low interfacial tension and high dispersion for functional particles (carrier, laser sensor, and antistatic agent). This matrix environment facilitates the formation of a continuous thermally conductive network by the carrier, thereby enabling the heat generated by the laser sensor during laser etching to dissipate uniformly and quickly. At the same time, it also imparts uniform distribution and inhibits migration of the antistatic agent, thus simultaneously solving the problems of ink immersion / flash defects and electrostatic adsorption, ultimately achieving excellent etching quality and uniform low surface resistance.

[0015] Preferably, the laser sensor is any one or a mixture of at least two of antimony-doped tin oxide, indium tin oxide, basic copper molybdate, and tungsten oxide.

[0016] The laser sensitizer refers to a functional additive that can significantly improve the material's ability to respond to laser energy. It can change the material's absorption behavior to lasers of a specific wavelength, promote the generation of local high temperature after the material absorbs the laser, and cause carbonization, foaming, color development, ablation and other effects when the material is etched under high temperature, thereby forming a high-contrast and permanent marking pattern.

[0017] Preferably, the antistatic agent is an ionic liquid.

[0018] This invention uses ionic liquid as an antistatic agent and, with the synergistic effect of the carrier and the composite polycarbonate matrix, achieves nanoscale uniform dispersion and appropriate surface migration in the film. During the melt processing, the ionic liquid can form a stable conductive network that runs through the entire polymer matrix (film), effectively suppressing the generation and accumulation of static charge. At the same time, due to its good compatibility with the matrix, it will not precipitate white frost or cause the surface to become sticky, and it does not affect the photothermal conversion efficiency of the laser sensor. This invention achieves the best balance between antistatic performance and high-quality laser etching patterns (high resolution, contrast, and no defects) by precisely controlling the total amount and internal ratio of functional particles.

[0019] Preferably, the carrier is any one or a mixture of at least two of polyethylene terephthalate, polybutylene terephthalate, polymethyl methacrylate, cyclic olefin copolymer, ethylene-vinyl alcohol, and polyimide.

[0020] This invention selects a general-purpose polymer with a thermal conductivity higher than polycarbonate as a carrier and pre-blends it with a laser sensor and an antistatic agent to form functional particles. During laser etching, the carrier utilizes its excellent thermal conductivity to rapidly conduct and dissipate the localized high-temperature heat generated instantaneously after the laser sensor absorbs light energy along the horizontal and vertical directions, avoiding heat accumulation and excessive carbonization in non-ideal areas. This fundamentally solves the two major problems in traditional laser etching: molten material buildup (flash) and carbonized residue penetration into the substrate (inking), caused by heat accumulation, while maintaining high contrast and edge sharpness in the etched area. Experiments show that using a carrier can achieve ink-free / flash-free etching, while without a carrier, severe flash and inking occur.

[0021] The carrier can be one or a mixture of several of the substances listed in Table 1 below: Table 1 Types of Carriers

[0022] This invention provides a method for preparing the aforementioned antistatic polycarbonate film that can be used for laser etching of identification cards, comprising the following steps: (1) Blending granulation: Laser sensitizer, antistatic agent and carrier are mixed to obtain functional particles; (2) Melt extrusion: The functional particles and the matrix polyester are mixed and then melt extruded to obtain an antistatic polycarbonate film.

[0023] Preferably, the total thickness of the antistatic polycarbonate film that can be used for laser etching of ID cards is 30-800 μm.

[0024] This invention provides the application of laser-etched antistatic polycarbonate films for use in the preparation of information security materials such as passports, ID cards, and driver's licenses.

[0025] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: 1. The laser-etched antistatic polycarbonate film for ID cards prepared by this invention has antistatic properties (surface resistance 10 Ω·cm). 9 -10 12 (Ohms / square), which can effectively reduce the dust adsorbed by the ester film, improve production efficiency and product yield. At the same time, the image after laser etching is clear, has high image resolution, rich color gradation, high image contrast, and no ink smearing or flash phenomenon.

[0026] 2. This invention uses a blend of high, medium and low melt index polycarbonates as the base polyester, which can work synergistically with functional particles to help provide stable melt rheological properties, effectively avoid melt fracture and surface defects, ensure the uniformity of functional particle dispersion in the matrix, and improve the extrusion film quality and thickness uniformity. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the layer structure of the laser-etched antistatic polycarbonate film used in the fabrication of ID cards according to Embodiment 1 of the present invention; wherein, the reference numerals are as follows: A - transparent polycarbonate film, from Suzhou Aomei Materials Technology Co., Ltd.; B - laser-etched polycarbonate film; C - white polycarbonate film, from Suzhou Aomei Materials Technology Co., Ltd.; Figure 2 This is an image of the etched pattern prepared in Example 1 of the present invention, which can be used for card manufacturing using laser etching of antistatic polycarbonate film; Figure 3 This is a magnified 200x photograph of the etching pattern prepared in Example 1 of the present invention, which can be used for card manufacturing using laser etching of antistatic polycarbonate film. Figure 4 This is the grayscale histogram of the etching pattern (maximum grayscale 249, minimum grayscale 65) prepared in Example 1 of the present invention and used for card making of antistatic polycarbonate film by laser etching. Figure 5 This is a photograph of the etched pattern prepared in Comparative Example 1 of the present invention, which can be used for card manufacturing using laser etching of antistatic polycarbonate film. Figure 6 This is a magnified 200x photograph of the etching pattern prepared in Comparative Example 1 of this invention, which can be used for card manufacturing using laser etching of antistatic polycarbonate film. Figure 7 is a grayscale histogram of the etching pattern prepared in Comparative Example 1 of the present invention after the card is made using laser etching of antistatic polycarbonate film for ID card manufacturing (maximum grayscale 247, minimum grayscale 10). Figure 8 This is a photograph of the etched pattern prepared in Comparative Example 2 of the present invention, which can be used for card manufacturing using laser etching of antistatic polycarbonate film. Figure 9 This is a photograph of the etched pattern prepared in Comparative Example 3 of the present invention, which can be used for printing antistatic polycarbonate films by laser etching on ID cards. Figure 10 This is a photograph of the etched pattern prepared in Comparative Example 7 of the present invention, which can be used for printing antistatic polycarbonate films by laser etching on ID cards. Figure 11 This is a photograph of the etched pattern prepared in Comparative Example 10 of the present invention, which can be used for printing antistatic polycarbonate films by laser etching on ID cards.

[0028] Figure 12 This is a photograph of the etched pattern prepared in Example 1 of the present invention, which can be used for printing antistatic polycarbonate films by laser etching on ID cards. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] All raw materials used in the following embodiments of the present invention are commercially available products: Unless otherwise specified, all raw materials used in this invention are commercially available or can be prepared using conventional methods in the art.

[0031] Packaging agents: PET from SABIC; PBT from KH2100 / Kanghui New Materials, SK601NC010 / Celanes, 110G30 / Nantong Zhonglan, 357M / SABIC, B4520 / BASF, B4500 / BASF; PMMA from 8N / Evonik Degussa, P80N / Asahi Kasei, IF850 / LG; COC from 5013L-10 / TAP, 8007F-04 from Ticona, 6013S-04 from Polyplastics; EVOH from E105B / Kuraray, F101A / Kuraray, GH3804B / Mitsubishi, 4405 / Chang Chung, Taiwan; PI from PL450A / Mitsui, PIPI-6200 / Mitsui. The laser-sensitive agents are antimony-doped tin oxide (Nanjing Haitai Nanomaterials Co., Ltd.), basic copper molybdate (Hunan Yuxi Ling New Material Technology Co., Ltd.), Irasorb BITO (Keelingwalker), and HN-WO80 tungsten oxide (Hangzhou Hengna New Material Co., Ltd.); the antistatic agent is PC2512 (Moni Chemical Technology (Shanghai) Co., Ltd.), and SY-8801 is Tianjin Shiyue Hengxin Technology Co., Ltd.

[0032] In the embodiments of the present invention, performance testing is performed using the following method: The CPL300 desktop laser etching machine for ID cards is from Shenyang Pairtech Technology Co., Ltd.

[0033] The WL-FA3000-8 laminator is from Wuhan Wenlin Technology Co., Ltd.

[0034] Example 1 This embodiment provides an antistatic polycarbonate film that can be used for laser etching of ID cards. The preparation method includes the following steps: (1) Functional particles: Functional particles containing carriers, laser sensitizers and antistatic agents were prepared by using a twin-screw compound extruder under the conditions that the first temperature in the granulation processing zone 1-5 was 105, 220, 260, 260 and 270℃ respectively.

[0035] The functional particles will contain the following components: by mass, Carrier: 25 parts polyethylene terephthalate; Laser-sensitive agent: 5 parts of antimony-doped tin oxide (Nanjing Haitai Nanomaterials Co., Ltd.); Antistatic agent: 15 parts of PC2512 (Shanghai Moni Chemical Co., Ltd.).

[0036] (2) Laser-etched antistatic polycarbonate film for ID cards: The installation used includes: The screw has a diameter of D105 mm and a length of 41×D, and the screw has a devolatileization zone; Crosshead; Special extrusion die, 1500mm wide; A three-roll polishing calender equipped with a horizontal roll: the third roll can rotate ±45° relative to the horizontal, along with a roller conveyor and a winding device.

[0037] The granules are fed into the hopper of the extruder. Material conveying and melting are completed in the barrel / screw plasticizing system. The molten material is extruded from the die and then to the polishing calender. Final shaping and cooling of the material take place on the polishing calender (consisting of three rollers). The ester film is then conveyed through a conveyor and finally wound up. Specific processing parameters are as follows: Table 2 Processing Parameters

[0038] The material composition is as follows: by weight, 5 functional particles; 100 parts of a base polyester, wherein the base polyester is polycarbonate; the polycarbonate comprises polycarbonate A, polycarbonate B, and polycarbonate C in a mass ratio of 1.3:1:0.4; under test conditions of 300°C / 1.2kg, the melt flow rate of polycarbonate A is 15 g / 10 min; grade name: KSD2421H; the melt flow rate of polycarbonate B is 10 g / 10 min; grade name: KSD1443R; and the melt flow rate of polycarbonate C is 22 g / 10 min; grade name: KSD6521ML. Dongguan Koside Plastics Technology Co., Ltd.

[0039] On the apparatus described above, a polycarbonate film with two structural surfaces and a layer thickness of 100 μm is extruded.

[0040] Example 2 The preparation method of the antistatic polycarbonate film for laser etching of ID cards in this embodiment is the same as that in embodiment 1, except that, by mass parts, in step 1: the carrier (25 parts), laser sensitive agent (5 parts), and antistatic agent (15 parts) are replaced with PBT from KH2100 (Kanghui New Materials), basic copper molybdate (Hunan Yuxi Ling New Materials Technology Co., Ltd.), and SY-8801 (Moni Chemical Technology (Shanghai) Co., Ltd.). Step 2: 1 part functional particles, 100 parts polyester matrix, and a polycarbonate film with a thickness of 30 μm.

[0041] Example 3 The preparation method of the antistatic polycarbonate film for laser etching of ID cards in this embodiment is the same as that in Embodiment 1, except that, by mass parts, in step 1: the carrier (25 parts), laser sensitizer (5 parts), and antistatic agent (15 parts) are replaced with SK601NC010 (Celanis), IrasorbBITO (Keelingwalker), and PC2512 (Moni Chemical Technology (Shanghai) Co., Ltd.); in step 2: 2 parts of functional particles, 100 parts of polyester matrix, and the polycarbonate film thickness is 50 μm.

[0042] Example 4 The preparation method of the antistatic polycarbonate film for laser etching of ID cards in this embodiment is the same as that in Embodiment 1, except that, by mass parts, in step 1: the carrier (25 parts), laser sensitizer (5 parts), and antistatic agent (15 parts) are replaced with COC from 5013L-10 (TAP, Germany), antimony-doped tin oxide (Nanjing Haitai Nanomaterials Co., Ltd.), and PC2512 (Moni Chemical Technology (Shanghai) Co., Ltd.), respectively; in step 2: 8 parts of functional particles, 100 parts of polyester matrix, and the polycarbonate film thickness is 100 μm.

[0043] Example 5 The preparation method of the antistatic polycarbonate film for laser etching of ID cards in this embodiment is the same as that in Embodiment 1, except that, by mass parts, in step 1: the carrier (25 parts), laser sensitizer (5 parts), and antistatic agent (15 parts) are replaced with EVOH from E105B (Kuraray, Japan), basic copper molybdate (Hunan Yuxi Lingxin New Material Technology Co., Ltd.), and SY-8801 from Tianjin Shiyue Hengxin Technology Co., Ltd., respectively; in step 2: 10 parts of functional particles, 100 parts of polyester matrix, and the polycarbonate film thickness is 200 μm.

[0044] Example 6 The preparation method of the antistatic polycarbonate film for laser etching of ID cards in this embodiment is the same as that in Embodiment 1, except that, by mass parts, in step 1: the carrier (25 parts), laser sensitizer (5 parts), and antistatic agent (15 parts) are replaced with PI from PL450A (Mitsui, Japan), antimony-doped tin oxide (Nanjing Haitai Nanomaterials Co., Ltd.), and PC2512 (Moni Chemical Technology (Shanghai) Co., Ltd.); in step 2: 15 parts of functional particles, 100 parts of polyester matrix, and the polycarbonate film thickness is 600 μm.

[0045] Example 7 The preparation method of the antistatic polycarbonate film for laser etching of ID cards in this embodiment is the same as that in Embodiment 1, except that, by mass parts, in step 1: the carrier (25 parts), laser sensitizer (5 parts), and antistatic agent (15 parts) are replaced with PET from PET PCG60 (Saudi Basic Industries Corporation), Irasorb BITO (Keelingwalker), and PC2512 (Moni Chemical Technology (Shanghai) Co., Ltd.); in step 2: 20 parts of functional particles, 100 parts of matrix polyester (LEXAN™ HPS6), and the polycarbonate film thickness is 800 μm.

[0046] Comparative Example 1 This comparative example is an antistatic polycarbonate film that can be used for laser etching of ID cards. The difference between this example and Example 1 is that it does not contain a carrier agent, but all other aspects are the same as those in Example 1.

[0047] Comparative Example 2 This comparative example is an antistatic polycarbonate film that can be used for laser etching of ID cards. The difference between this example and Example 1 is that it does not contain a laser-sensitive agent, but otherwise it is the same as Example 1.

[0048] Comparative Example 3 This comparative example provides an antistatic polycarbonate film that can be used for laser etching of ID cards. The difference between this example and Example 1 is that it does not contain an antistatic agent; otherwise, they are the same as in Example 1.

[0049] Comparative Example 4 This comparative example provides an antistatic polycarbonate film suitable for laser etching of identification cards. The difference between this example and Example 1 is that the MVR of the polycarbonate is 10 g / 10 min (300). o C / 1.2kg), and everything else is the same as in Example 1.

[0050] Comparative Example 5 This comparative example provides an antistatic polycarbonate film suitable for laser etching of ID cards. The difference between this example and Example 1 is that the base polyester is polycarbonate; the polycarbonate has a melt flow rate of 15 g / 10 min under test conditions of 300°C / 1.2 kg; Grade Name: KSD2421H; Dongguan Koside Plastics Technology Co., Ltd.

[0051] Comparative Example 6 This comparative example presents an antistatic polycarbonate film suitable for laser etching of identification cards. The difference between this example and Example 1 is that the base polyester is polycarbonate; the polycarbonate comprises polycarbonate A and polycarbonate C in a 1:1 mass ratio; under test conditions of 300°C / 1.2kg, the melt flow rate of polycarbonate A is 15g / 10min; grade name: KSD2421H, and the melt flow rate of polycarbonate C is 22g / 10min; grade name: KSD6521ML. Dongguan Koside Plastics Technology Co., Ltd.

[0052] Comparative Example 7 This comparative example presents an antistatic polycarbonate film suitable for laser etching of identification cards. The difference between this example and Example 1 is that the base polyester is polycarbonate; the polycarbonate comprises polycarbonate A, polycarbonate B, and polycarbonate C in a mass ratio of 1:1.2:0.7; under test conditions of 300°C / 1.2kg, the melt flow rate of polycarbonate A is 15g / 10min; grade name: KSD2421H; the melt flow rate of polycarbonate B is 10g / 10min; grade name: KSD1443R; and the melt flow rate of polycarbonate C is 22g / 10min; grade name: KSD6521ML. Dongguan Koside Plastics Technology Co., Ltd.

[0053] Comparative Example 8 This comparative example presents an antistatic polycarbonate film suitable for laser etching of identification cards. The difference between this example and Example 1 is that the base polyester is polycarbonate. The polycarbonate comprises polycarbonate A, polycarbonate B, and polycarbonate C in a mass ratio of 1.6:0.7:0.2. Under test conditions of 300°C / 1.2kg, the melt flow rate of polycarbonate A is 15g / 10min; grade name: KSD2421H; the melt flow rate of polycarbonate B is 10g / 10min; grade name: KSD1443R; and the melt flow rate of polycarbonate C is 22g / 10min; grade name: KSD6521ML. Dongguan Koside Plastics Technology Co., Ltd.

[0054] Comparative Example 9 This comparative example is an antistatic polycarbonate film that can be used for laser etching of ID cards. The difference between this example and Example 1 is that it does not contain functional particles, but everything else is the same as Example 1.

[0055] Comparative Example 10 This comparative example is an antistatic polycarbonate film that can be used for laser etching of ID cards. The difference between this example and Example 1 is that the functional particles are 200 parts, while the rest are the same as in Example 1.

[0056] Comparative Example 11 This comparative example is an antistatic polycarbonate film that can be used for laser etching of ID cards. The difference between this example and Example 1 is that the thickness is 1000 μm, while the rest are the same as in Example 1.

[0057] Application examples ID card production: The antistatic polycarbonate films prepared in all Examples 1-7 and Comparative Examples 1-11 that can be used for laser etching of ID cards are laminated with transparent polycarbonate films and white polycarbonate films at high temperature.

[0058] The following is a laminated stacking structure: Layer (A): Transparent polycarbonate film, 100 micrometers; Layer (B): Laser-etched antistatic polycarbonate film, 100 micrometers; Layer (C): White polycarbonate film, 150 micrometers; Lamination process: Perform the following parameters on the WL-FA3000-8 laminator; Preheat the press to 175°C; press for 20 minutes at a pressure of 7 MPa; Press for 15 minutes at a pressure of 7 MPa; Cool the press to 18°C ​​and then turn it on.

[0059] Laser Personalization: Laser engraving was performed on thin-film ID cards using a CPL300 desktop ID card laser etching machine, with the following parameters: Laser medium: Nd:YAG Wavelength: 1064nm Power: 40 watts Current: 30A Q frequency: 100kHz Forward speed: 1300 mm / s.

[0060] Laser Etching: Personal information and a complete, high-contrast black-and-white portrait of a woman are laser-engraved onto a laser-writable layer on a laser-etched antistatic polycarbonate film (B layer). After card production, the card is scanned, and then an image analysis program is used to measure the horizontal intensity profile on the gray wedge to obtain a color gradation histogram.

[0061] The laser-etched antistatic polycarbonate films prepared in Example 1 and Comparative Examples 1, 2, 3, 7, and 10 were then printed with patterns, pressed into cards, and finally subjected to laser-etched personal information processing to verify the antistatic effect against dust adsorption. Performance test results are shown in Table 3 and... Figure 1-12 .

[0062] Table 3 Performance Test Results

[0063] Note: Contrast ratio: The ratio of the gray value intensity at the coordinate with the maximum gray-level gradient to the gray value intensity at the coordinate with the minimum gray-level gradient. The higher the value (quotient), the better the contrast ratio.

[0064] :pass; Failed In Comparative Example 1, there was no carrier agent, and the heat could not be dissipated quickly during laser etching, resulting in excessively high temperature, severe carbonization, and improved contrast, but also severe ink smearing and flash. Figure 5 , Figure 6 (and Figure 7).

[0065] In Comparative Example 2, the absence of a laser-sensitive agent reduces laser absorption, resulting in a significant decrease in contrast and unclear etched images. Figure 8 ).

[0066] In Comparative Example 3, the absence of an antistatic agent leads to increased dust accumulation during laser etching of the polycarbonate film, resulting in more dust particles and a deterioration in the appearance of the identification card. Figure 9 ).

[0067] In Comparative Examples 4-8, the improper melt index ratio of the base polyester resulted in poor B-layer quality of the laser-etched polycarbonate film. Comparative Examples 4, 6, and 8 even failed to form a film, while Comparative Examples 5 and 7 exhibited uneven thickness, uneven dispersion of the antistatic agent, and large variations in surface resistance. This also caused uneven cumulative thickness during card making, unstable laser etching focus, and the appearance of ink splatter / flash phenomena. Figure 10 (For comparison example 7, card etching photograph).

[0068] In Comparative Example 9, the absence of functional particles reduces laser absorption, resulting in no etching effect.

[0069] In Comparative Example 10, 200 parts of functional particles were present, but the laser sensitizer was excessive, resulting in excessively high laser etching temperature, severe ablation and carbonization, and significant ink penetration and flash. Figure 11 ).

[0070] The difference in Comparative Example 11 is that the thickness is 1000μm, which exceeds the card thickness requirement.

[0071] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A type of antistatic polycarbonate film that can be used for laser etching of ID cards, characterized in that, By weight, the antistatic polycarbonate film for laser etching of ID cards comprises the following components: 1-20 parts of functional particles and 100 parts of polyester matrix.

2. The antistatic polycarbonate film for laser etching of ID cards according to claim 1, characterized in that, By weight, the functional particles comprise the following components: 2-7 parts laser sensitizer, 10-20 parts antistatic agent, and 22-30 parts carrier.

3. The antistatic polycarbonate film for laser etching of ID cards according to claim 1, characterized in that, The base polyester is polycarbonate, which includes polycarbonate A, polycarbonate B and polycarbonate C in a mass ratio of (1.2-1.4):1:(0.3-0.5).

4. The antistatic polycarbonate film for laser etching of ID cards according to claim 3, characterized in that, Under test conditions of 300°C / 1.2kg, the melt flow rate of polycarbonate A was 14-16 g / 10 min; the melt flow rate of polycarbonate B was 8-11 g / 10 min; and the melt flow rate of polycarbonate C was 20-23 g / 10 min.

5. The antistatic polycarbonate film for laser etching of ID cards according to claim 2, characterized in that, The laser sensor is any one or a mixture of at least two of the following: antimony-doped tin oxide, indium tin oxide, basic copper molybdate, and tungsten oxide.

6. The antistatic polycarbonate film for laser etching of ID cards according to claim 2, characterized in that, The antistatic agent is an ionic liquid.

7. The antistatic polycarbonate film for laser etching of ID cards according to claim 2, characterized in that, The carrier is any one or a mixture of at least two of the following: polyethylene terephthalate, polybutylene terephthalate, polymethyl methacrylate, cyclic olefin copolymer, ethylene-vinyl alcohol, and polyimide.

8. The method for preparing an antistatic polycarbonate film for laser etching of identification cards according to any one of claims 1-7, characterized in that, Includes the following steps: (1) Blending granulation: Laser sensitizer, antistatic agent and carrier are mixed to obtain functional particles; (2) Melt extrusion: The functional particles and the matrix polyester are mixed and then melt extruded to obtain an electrostatic polycarbonate film that can be used for laser etching of ID cards.

9. The method for preparing an antistatic polycarbonate film for laser etching of identification cards according to claim 8, characterized in that, The total thickness of the antistatic polycarbonate film that can be used for laser etching of ID cards is 30-800 μm.

10. The application of the laser-etched antistatic polycarbonate film for ID cards according to any one of claims 1-7 in the preparation of information security materials for passports, identity documents and driver's licenses.

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