High-resolution thermal transfer ribbon capable of being used in extreme environment and preparation method of high-resolution thermal transfer ribbon

Abstract

The invention relates to a high-resolution thermal transfer ribbon capable of being used in an extreme environment. The high-resolution thermal transfer ribbon is composed of a base film, a weather-proof back coating, a chemical corrosion-resistant middle layer and an ink layer, wherein the weather-proof back coating is coated on one side of the base film; the chemical corrosion-resistant middle layer and the ink layer are sequentially coated on the other side of the base film; wherein the chemical-corrosion-resistant middle layer is mainly prepared from the following raw materials in percentage by mass: 20-35% of a solvent, 1-5% of a silane coupling agent, 1-5% of a dispersing agent and the balance of resin, and the resin is formed by mixing acrylic resin and epoxy resin according to the mass ratio of 3: 1-5: 1. The thermal transfer ribbon provided by the invention can still keep the resolution of a printed image being greater than or equal to 600dpi, the alcohol friction resistance being greater than or equal to 100 times and the light retention rate being greater than or equal to 90% in a weather resistance test (QUV 5000h) under the environments of high temperature (150 DEG C), high humidity (95% RH), strong acid (pH = 1), strong alkali (pH = 13) and low temperature (-50 DEG C), solves the problems of blurring, color fading and poor adhesion of a thermal transfer ribbon image in an extreme environment, and is suitable for the fields of aerospace, chemical identification, polar scientific investigation and the like.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of thermal transfer printing materials, and particularly relates to a high-resolution thermal transfer printing carbon ribbon applicable to extreme environments and a preparation process thereof. The thermal transfer printing carbon ribbon can maintain the stability and high resolution of printed images in high and low temperature environments (-50℃ to 150℃), high humidity environments (≤95% RH), strong acid and strong alkali environments, and is applicable to aerospace identification, chemical pipeline labels, polar scientific research instrument labels and the like. BACKGROUND

[0002] At present, the core performance defects of thermal transfer printing carbon ribbons are insufficient weather resistance and adhesion in extreme environments, which are specifically listed as follows: 1) The ink layer is prone to softening and adhesion in high temperature and high humidity environments, resulting in a decrease in resolution (the resolution of traditional carbon ribbons is ≤300 dpi); 2) Low temperature embrittlement leads to cracking of the interface between the base film and the coating (traditional carbon ribbons crack after being bent 3 times at -50℃); 3) The ink components are prone to hydrolysis or oxidation in chemical corrosion environments, causing discoloration or peeling (the mass loss rate of traditional carbon ribbons is ≥5% after being immersed in H2SO4 solution with pH=1 for 24 h); 4) Insufficient wear resistance (the alcohol rubbing resistance of traditional resin-based carbon ribbons is ≤50 times). In the prior art, the weather resistance test standard of the high-end carbon ribbon market dominated by Japanese DNP and other enterprises only reaches QUV 2000h gloss retention ≥80%. The present application significantly improves the above-mentioned performances through multi-layer composite structure design and material synergistic modification.

[0003] In addition, in view of the significant photothermal instability of the existing thermal sublimation ink, as well as the characteristics of easy sublimation at high temperature and easy condensation at low temperature, the thermal sublimation ink has poor weather resistance (fastness to light ≤3 levels) and insufficient QUV aging resistance (color difference ΔE > 5.0 after 1000 hours), and other technical defects, especially when applied to the surface of aluminum profiles, the ink layer is prone to peeling and discontinuity (complete transfer rate < 85%) and adhesion decreases after artificial accelerated aging (100% area test peeling area ≥15%) and other problems, and therefore it is urgent to develop a thermal transfer printing carbon ribbon with high resolution and strong adhesion in extreme environments. SUMMARY

[0004] The present application aims to overcome the defects of the prior art, and provides a high-resolution thermal transfer carbon ribbon applicable to extreme environments and a preparation process thereof. The thermal transfer carbon ribbon is designed with a multi-layer composite coating structure and the materials are synergistically modified, so that the thermal transfer carbon ribbon can maintain the stability and high resolution of the printed image in high and low temperature environments (-50 DEG C to 150 DEG C), high humidity (≤95% RH), strong acid (pH = 1) and strong alkali (pH = 13) environments, the resolution is ≥600 dpi, the alcohol rubbing resistance is ≥100 times, the light retention rate is ≥90% in the weather resistance test (QUV 5000h), the problems of image blurring, discoloration and poor adhesion of the thermal transfer carbon ribbon in extreme environments are solved, and the thermal transfer carbon ribbon is suitable for fields such as aerospace identification, chemical pipeline labels, polar scientific research instrument labels and the like. To achieve the above-mentioned purpose, the present application adopts the following technical solutions: A high-resolution thermal transfer carbon ribbon applicable to extreme environments is composed of a base film, a weather-resistant back coating layer coated on one side of the base film, and an anti-chemical corrosion intermediate layer and a high-adhesion ink layer successively coated on the other side of the base film. The anti-chemical corrosion intermediate layer is mainly made of raw materials in the following mass percentages: 20-35% solvent, 1-5% silane coupling agent, 1-5% dispersant, and the balance of resin. The resin is composed of acrylic resin and epoxy resin in a mass ratio of 3:1-5:1, and the two can be compounded to form a crosslinked structure. The crosslinking density of the acrylic resin and the epoxy resin in the anti-chemical corrosion intermediate layer is 85%-92% under the action of the silane coupling agent, which can effectively block the penetration of acid and alkali substances. The mass loss rate is ≤0.3% after soaking in HCl solution with pH = 1 and NaOH solution with pH = 13 for 240h in the acid and alkali resistance test.

[0005] Specifically, the high-adhesion ink layer is mainly composed of 98-99% ink and 1-2% microcapsules, and the ink is mainly made of raw materials in the following mass percentages: 10-15% SEBS resin, 10-15% acrylic resin, 5-15% polyethylene micro-wax, 1-5% nano-sized titanium dioxide TiO2, 5-15% surface pretreated nano-sized carbon black, 0.5%-3% dispersant, 2-5% adhesion promoter, and the balance of solvent.

[0006] Specifically, the weather-resistant back coating layer is mainly made of raw materials in the following mass percentages: 12-30% resin, 1%-5% H-11 crosslinking weather-resistant agent, 1-5% silicone filler, and the balance of solvent. The main components of the weather-resistant back coating layer are 10%-20% fluorocarbon resin, 5%-10% acrylic resin, 1%-5% silicone filler, 1%-5% H-11 crosslinking weather-resistant agent and solvent, which construct a "micro-scaffold" structure to reduce the high-temperature adhesion phenomenon.

[0007] Furthermore, in the carbon ribbon of the present invention, the solvent in the weather-resistant back coating, the chemical corrosion-resistant intermediate layer, and the high-adhesion ink layer can be at least one of toluene, xylene, methyl ethyl ketone, etc.

[0008] Furthermore, the nano-sized titanium dioxide particles in the ink layer have a particle size of 1-150 nm, and the surface-pretreated nano-sized carbon black particles have a particle size of 20-50 nm. The surface-pretreated nano-sized carbon black is prepared through the following steps: Nanoscale carbon black and water were mixed at a mass ratio of 1:8-9 to obtain a carbon black slurry, and the pH was adjusted to 8.0-9.0 with sodium hydroxide solution. γ-methacryloxypropyltrimethoxysilane and water were mixed at a mass ratio of 1:8-10 to obtain a silane solution. Under an inert gas atmosphere, the silane solution was added dropwise to the carbon black slurry at a rate of 0.3-0.7 mL / min, and then the mixture was stirred at room temperature (25±5℃) for 30-60 min (stirring speed 800-1200 rpm). After solid-liquid separation and drying, the final product was obtained. The amount of γ-methacryloxypropyltrimethoxysilane added is 2-5% of the mass of carbon black.

[0009] Furthermore, the microcapsules are prepared via the following steps: Sodium dodecylbenzenesulfonate, the emulsifier, and n-butanol, the co-emulsifier, are dissolved in deionized water (stirred at 500-800 rpm for 10-20 min to promote dissolution) to prepare an aqueous solution. Under conditions of 25-30℃ and stirring at 1500-2000 rpm, the ink is added dropwise to the aqueous solution (dropping rate 1-2 mL / min), and stirred to form an O / W emulsion. The emulsion is then transferred to a high-pressure homogenizer, and the pressure is set to 30-40... Under conditions of MPa and temperature of 25-30℃, homogenize the mixture 2-3 times until the particle size is stabilized at 0.5±0.05μm. Then, add dimethyl terephthalate (DMT), ethylene glycol (EG), the crosslinking monomer hexanediol diacrylate, and the polymerization inhibitor hydroquinone. Stir the mixture at 30-35℃ and 800-1000 r / min for 30-40 min to allow the monomers to fully migrate to the oil-water interface. Add cobalt acetate as a catalyst to the system and heat to 275-290℃ for vacuum polycondensation reaction for 2-3 h to obtain the final product. The mass ratio of the emulsifier to the co-emulsifier is 4-6:1; The mass ratio of dimethyl phthalate, ethylene glycol, crosslinking monomer, polymerization inhibitor, and catalyst is 2000:900-1100:80-120:3-7:15-25; The mass ratio of the ink, dimethyl terephthalate, and emulsifier is 100:10-15:2-5.

[0010] Furthermore, the particle size of the silicone filler in the weather-resistant back coating can be 0.5-1.2 μm. The fluorocarbon resin used in the weather-resistant back coating has a viscosity of 120-150 s at 25°C.

[0011] Furthermore, the base film is preferably a polyester film with a thickness of 3.0-4.5 μm, and its surface is corona-treated to achieve a surface tension of 30-42 dyn / cm² to enhance interlayer adhesion. In the preparation process of the thermal transfer ribbon of this invention, the base film pretreatment involves: firstly, corona treatment is performed, with the power set between 2-3 kW and the processing speed at 300 meters per minute, to significantly improve the adhesion of the base film surface and ensure that subsequent coatings can better adhere to the base film. During the back coating process, a 300-line ceramic anilox roller is used for precise coating. The base film coated with the back coating is then placed in a drying device with a drying temperature set at 80-130 degrees Celsius to ensure that the back coating adheres evenly and firmly to the base film. The intermediate layer coating is performed using gravure printing technology. This technology ensures uniform ink distribution and, through precise control of printing parameters, achieves ideal pattern and color effects. During the ink layer coating process, sand milling technology is used to treat the ink, ensuring that the particle size after sand milling is 0.2-0.5 μm. This significantly improves the smoothness and fineness of the ink layer, thereby enhancing the visual effect and quality of the final product.

[0012] This invention provides a method for preparing the above-mentioned high-resolution thermal transfer ribbon suitable for extreme environments, which includes the following steps: 1) In the weather-resistant back coating, fluorocarbon resin, acrylic resin and silicone filler are added to the solvent, heated and stirred until uniformly dispersed, crosslinking weather-resistant agent is added, dispersed and ground to make the particle size reach about 0.2-0.5μm, and weather-resistant back coating is obtained. 2) In the chemical corrosion resistant intermediate layer, acrylic resin and epoxy resin are added to the solvent and heated and stirred until they are evenly dispersed. Dispersant and silane coupling agent are added, dispersed, and ground to make the particle size reach about 0.1-0.3μm, thus obtaining the chemical corrosion resistant intermediate layer coating. 3) In the ink layer, acrylic resin, SEBS resin, polyethylene micro powder wax, and nano-sized titanium dioxide are added to the solvent and dispersed evenly under heating and stirring. Dispersant, adhesion promoter, and surface pretreated nano-sized carbon black are added and ground to achieve a particle size of 0.2-0.5μm. Finally, microcapsules are added and dispersed evenly to obtain the ink layer coating. 4) Perform double-sided corona treatment on the base film with a treatment power of 2-5kW and a film flow speed of 200-350m / min. The surface after corona treatment reaches 30-42dyn / cm². 5) Using a gravure coating machine, apply a weather-resistant back coating to the underside of the base film with a coating amount of 0.5-1.5 g / m². Then, dry the coating at a gradient temperature of 80-130℃ to form a weather-resistant back coating with a thickness of 1-2 μm. The first stage is drying at 80±2℃ for 30 seconds, the second stage is drying at 130±2℃ for 45 seconds, and the third stage is drying at 110±2℃ for 30 seconds. 6) Using a gravure coating machine, apply an anti-chemical corrosion intermediate layer coating to the upper surface of the base film, and dry it at a gradient temperature of 80-130℃ to form an anti-chemical corrosion intermediate layer with a thickness of 0.5-1.5μm. The first stage is drying at 80±2℃ for 30s, the second stage is drying at 130±2℃ for 45s, and the third stage is drying at 110±2℃ for 30s. 7) Using a gravure coating machine, apply an ink layer coating onto the dried chemical corrosion resistant intermediate layer, and then dry it at a gradient temperature of 80-130℃ to form an ink layer with a thickness of 1-2μm. The first stage is drying at 80±2℃ for 30s, the second stage is drying at 130±2℃ for 45s, and the third stage is drying at 110±2℃ for 30s to obtain the final product.

[0013] This invention also provides applications of the aforementioned high-resolution thermal transfer ribbons suitable for extreme environments in aerospace markings, chemical pipeline labels, polar scientific research instrument nameplates, etc.

[0014] Ordinary carbon ribbons are typically recommended for use at temperatures between 5°C and 35°C and relative humidity between 45% and 85%, and are only resistant to weak solvents. The key innovation of this invention lies in its three-coating system, each layer reinforced for different specific environments, while advanced processes are introduced in the preparation and treatment of the base film. Specifically, it consists of a chemically resistant intermediate layer, a high-adhesion ink layer, and a weather-resistant back coating. These three coatings are reinforced for different specific environments, ensuring normal use even in challenging conditions.

[0015] The innovative aspects of the high-resolution thermal transfer ribbon and its preparation process that can be used in extreme environments described in this invention are as follows: 1) A three-layer coating system was constructed, in which the carbon ribbon consists of a chemically resistant intermediate layer, a high-adhesion ink layer, and a weather-resistant back coating, ensuring transfer integrity, low-temperature printing, high-temperature printing, anti-aging, anti-scratch, acid and alkali resistance, and high and low temperature resistance.

[0016] 2) The "micro-scaffold" structure of the weather-resistant back coating: The uniform distribution of silicone filler effectively reduces the interlayer contact area, thereby reducing stress concentration and improving peel resistance in high temperature and high humidity environments.

[0017] 3) Add self-healing microcapsules to the ink layer. When the surface of the ribbon is slightly damaged due to friction or chemical erosion, the microcapsules rupture and release the repair agent, which automatically fills the damaged area, maintains the integrity and performance of the ribbon, and further enhances its wear resistance and corrosion resistance in extreme environments.

[0018] 4) Chemical corrosion resistant intermediate layer: By synthesizing an acrylic resin-epoxy resin-additive hybrid system, the penetration path of acid and alkali substances is effectively blocked, thus ensuring printing effect in strong acid and strong alkali environments.

[0019] 5) Interface enhancement technology: The film adopts integrated plasma-assisted deposition (PECVD technology) to form a film with consistent thickness and composition. Corona treatment enhances the interfacial adhesion. The ink layer is treated with silane coupling agent nano-TiO2, which significantly improves the adhesion between the ink layer and the intermediate layer, thereby improving alcohol resistance and abrasion resistance.

[0020] 6) A combination of highly stable wax and resin materials is used. The base film is made using PECVD technology and is corona treated. Polyimide labels are selected. A ceramic printhead with a resolution of 600dpi or higher is used. At the same time, the temperature and pressure of the printhead are adjusted to ensure high-resolution transfer.

[0021] This invention improves the integrity, adhesion, abrasion resistance, alcohol resistance, corrosion resistance, and weather resistance of a back coating "microscaffold" structure, self-healing microcapsules in the ink layer, and a cross-linked intermediate layer. Compared with existing technologies, the advantages and beneficial effects of this invention are as follows: This invention is particularly suitable for surface treatment of metals in harsh environments, such as aluminum alloy components in the aerospace field (e.g., skin markings) and marine engineering equipment (e.g., corrosion-resistant signs for offshore platforms). By employing a composite process of "powder coating + transfer film," the product can achieve a weather-resistant lifespan of 15-20 years, and the overall cost can be reduced by more than 40% compared to traditional electroplating processes.

[0022] After actual testing and verification, the carbon ribbon technology proposed in this application exhibits the following significant performance characteristics: after 5000 hours of QUV aging test, the color difference ΔE value does not exceed 1.5 (according to ISO 105-B02 standard), and the light retention rate is not less than 90%; it does not crack when placed at a low temperature of -50℃; in the abrasion resistance test, the surface after heat transfer is scratch-free, and it maintains stable quality in strong acids and alkalis.

[0023] Actual measurements show that the performance of the carbon ribbon of this invention is significantly better than that of existing traditional resin-based carbon ribbons. The comparative data is shown in the table below. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the high-resolution thermal transfer ribbon of the present invention, which can be used in extreme environments. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to its embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of the invention.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0027] The present invention will be further explained below with reference to the embodiments. However, before introducing the specific embodiments, the performance of some materials in the following embodiments will be briefly described as follows.

[0028] Ultra-thin polyester film, 3.5µm thick, tensile strength 320MPa, heat distortion temperature ≥150℃, is a common commercially available product.

[0029] Epoxy resin: molecular weight 80,000-90,000, glass transition temperature 110℃, using R-110S from Nissin Chemical Industry Co., Ltd.

[0030] Acrylic resin: molecular weight 80,000-100,000, acid value <3.00mgKOH / g, glass transition temperature Tg: 100℃, Mitsubishi acrylic resin Diana BR-73 is selected.

[0031] SEBS resin: molecular weight 70,000–90,000, glass transition temperature 100℃, using American Kraton model G-1657.

[0032] Polyethylene micronized wax: with a particle size of 1-1.5μm, dropping point of 122℃, penetration of 1, and melt viscosity of 200, using Weng Kai'er-120 from Weng Kai'er (Shanghai) International Trading Co., Ltd.; Nano-sized titanium dioxide: particle size 1-150nm, selected from Sigma-Aldrich (Shanghai) Trading Co., Ltd. 799289; Carbon black: particle size 20-50nm, oil absorption value 90, ash content 0.1, Cabot carbon black CSX1022A is selected; Fluorocarbon resin: molecular weight 10000-15000, viscosity: 100-2000 mPa·s. Shanghai Puvilli Special Materials Co., Ltd. FEVE TFB-G1.

[0033] The dispersant is BYK's DISPERBYK-2118. The silane coupling agent is BYK's DISPERBYK-3941. The adhesion promoter is KEPERADH-992 from Jintong, and the H-11 crosslinking and weather-resistant agent is Carboline's Carboguard-1207.

[0034] In the following embodiments, the solvent in the weather-resistant back coating, the chemical corrosion-resistant intermediate layer, and the high-adhesion ink layer is toluene.

[0035] In the examples, the surface-pretreated nanoscale carbon black used was prepared by the following steps: Nanoscale carbon black and water were mixed at a mass ratio of 1:8 to obtain a carbon black slurry, and the pH was adjusted to 8.5 with sodium hydroxide solution. γ-methacryloxypropyltrimethoxysilane and water were mixed at a mass ratio of 1:9 to obtain a silane solution. Under a nitrogen atmosphere, the silane solution was added dropwise to the carbon black slurry at a rate of 0.5 mL / min. The mixture was then stirred at room temperature (25±2℃) for 45 min (stirring speed 1000 rpm). After centrifugation, washing, and vacuum drying at 60℃ for 12 h, the final product was obtained. The amount of γ-methacryloxypropyltrimethoxysilane added is 3% of the mass of carbon black.

[0036] In the examples, the microcapsules used were prepared by the following steps: Sodium dodecylbenzenesulfonate, an emulsifier, and n-butanol, a co-emulsifier, were dissolved in deionized water at a mass ratio of 5:1 (the amount of deionized water added was 9 times the mass of the emulsifier, and the mixture was stirred at 700 r / min for 15 min to promote dissolution) to prepare an aqueous solution. Under the conditions of 25-30℃ and stirring at 1800 r / min, ink was added dropwise to the aqueous solution (dropping rate 1.5 mL / min), and stirred for 30 min to form an O / W emulsion. The emulsion was transferred to a high-pressure homogenizer, set at 35 MPa and 28℃, and homogenized three times until the particle size was stabilized at 0.5±0.05μm. Then, dimethyl terephthalate (DMT), ethylene glycol (EG), the crosslinking monomer hexanediol diacrylate, and the polymerization inhibitor hydroquinone were added. The mixture was stirred at 30-35℃ and 900 r / min for 35 min to allow the monomers to migrate fully to the oil-water interface. Cobalt acetate catalyst was added to the system, and the mixture was heated to 285℃ for vacuum polycondensation for 2.5 h to obtain the final product. The mass ratio of DMT, EG, crosslinking monomer, polymerization inhibitor, and catalyst is 2000:1000:100:5:20. The mass ratio of the ink, dimethyl terephthalate, and emulsifier is 100:13:3.

[0037] Example 1: A high-resolution thermal transfer ribbon suitable for extreme environments comprises a base film, a weather-resistant back coating applied to one side of the base film, a chemically resistant intermediate layer and a high-adhesion ink layer sequentially applied to the other side of the base film (e.g., Figure 1 (As shown).

[0038] The chemical corrosion resistant intermediate layer is mainly composed of the following raw materials in the following mass percentages: 33% solvent, 5% silane coupling agent and 2% dispersant, 45% acrylic resin and 15% epoxy resin.

[0039] By weight percentage, the high-adhesion ink layer is mainly composed of 99% ink and 1% microcapsules. The ink is mainly made of the following raw materials by weight percentage: 10% SEBS resin, 15% acrylic resin, 12% polyethylene micronized wax, 3% nano-sized titanium dioxide, 15% surface pretreatment nano-sized carbon black, 1% dispersant, 3% adhesion promoter, and 41% solvent.

[0040] The weather-resistant back coating is mainly made of the following raw materials in the following weight percentages: 15% fluorocarbon resin, 10% acrylic resin, 65% solvent, 5% H-11 crosslinking weather-resistant agent and 5% silicone filler.

[0041] The above-mentioned method for preparing high-resolution thermal transfer ribbons suitable for extreme environments includes the following steps: The base film was subjected to double-sided corona treatment with a treatment power of 3kW and a film flow rate of 300m / min. The surface of the corona-treated film reached 35dyn / cm². Back coating: Fluorocarbon resin, acrylic resin and silicone filler are added to the solvent and heated and stirred until uniformly dispersed. Crosslinking weather-resistant agent is added, dispersed and ground to achieve a particle size of 0.4μm. Gravure coating machine is used to uniformly coat the back coating on the lower surface of the base film. After drying (first stage: 80℃ for 30s, second stage: 130℃ for 45s, third stage: 110℃ for 30s), a back coating with a thickness of 1.1μm is formed. Intermediate layer: Acrylic resin and epoxy resin are added to the solvent and heated and stirred until they are evenly dispersed. Dispersant and silane coupling agent are added and dispersed and ground to make the particle size reach about 0.3μm. Gravure coating machine is used to evenly coat the substrate film. After drying (first stage 80℃ drying for 30s, second stage 130℃ drying for 45s, third stage 110℃ drying for 30s), an intermediate layer with a thickness of 0.8μm is formed. Ink layer: Acrylic resin, SEBS resin, polyethylene micron wax, and nano-sized titanium dioxide are added to the solvent and heated and stirred until uniformly dispersed. Dispersant, adhesion promoter, and surface-pretreated nano-sized carbon black are added and ground to achieve a particle size of about 0.5μm. Finally, microcapsules are added and dispersed evenly. The mixture is then coated evenly on the intermediate layer using a gravure coating machine and dried (first stage: 80℃ for 30s, second stage: 130℃ for 45s, third stage: 110℃ for 30s) to form an ink layer with a thickness of 1.5μm; thus, the carbon ribbon is obtained.

[0042] The performance test results are as follows: Resolution: The test was conducted using a 600dpi printer. The results showed that the lines were clear and there was no diffusion (the ink droplet diameter was ≤20μm as observed by SEM), which is a significant improvement compared to the 300dpi resolution of traditional ribbons.

[0043] Weather resistance: After 5000 hours of QUV testing, the coating retains 92% of its gloss, with a color difference ΔE value of less than 1.5. Chemical stability: After immersing the ribbon in hydrochloric acid solution with a pH of 1 for 24 hours, the image shows no peeling; after immersing in sodium hydroxide solution with a pH of 13 for 24 hours, the fading rate is less than 3%. Low-temperature performance: After storage at -50℃ for 24 hours, the coating shows no cracks, and the printing resolution remains ≥600 dpi. High-temperature performance: After storage at 150℃ for 24 hours, the ribbon shows no back-sticking, and the printing resolution remains ≥600 dpi.

[0044] After heat transfer printing, the abrasion resistance test showed no scratches on the pattern surface after 500 rubs with an eraser and 100 rubs with alcohol.

[0045] Example 2: A high-resolution thermal transfer ribbon suitable for extreme environments consists of a base film, a weather-resistant back coating applied to one side of the base film, and a chemically resistant intermediate layer and a high-adhesion ink layer sequentially applied to the other side of the base film.

[0046] The chemical corrosion resistant intermediate layer is mainly composed of the following raw materials in the following mass percentages: 33% solvent, 5% silane coupling agent and 2% dispersant, 50% acrylic resin and 10% epoxy resin.

[0047] By weight percentage, the high-adhesion ink layer is mainly composed of 99% ink and 1% microcapsules. The ink is mainly made of the following raw materials by weight percentage: 15% SEBS resin, 10% acrylic resin, 12% polyethylene micro powder wax, 3% nano-grade titanium dioxide, 15% surface pretreatment nano-grade carbon black, 1% dispersant, 3% adhesion promoter, and 41% solvent.

[0048] The weather-resistant back coating is mainly made of the following raw materials in the following weight percentages: 17% fluorocarbon resin, 8% acrylic resin, 65% solvent, 5% H-11 crosslinking weather-resistant agent and 5% silicone filler.

[0049] The above-mentioned method for preparing high-resolution thermal transfer ribbons suitable for extreme environments includes the following steps: The base film was subjected to double-sided corona treatment with a treatment power of 3kW and a film flow rate of 300m / min. The surface of the corona-treated film reached 35dyn / cm². Back coating: Fluorocarbon resin, acrylic resin and silicone filler are added to the solvent and heated and stirred until uniformly dispersed. Crosslinking weather-resistant agent is added and dispersed and ground to make the particle size reach about 0.4μm. Gravure coating machine is used to uniformly coat the back coating on the lower surface of the base film. After drying (first stage 80℃ drying for 30s, second stage 130℃ drying for 45s, third stage 110℃ drying for 30s), a back coating with a thickness of 1.1μm is formed. Intermediate layer: Acrylic resin and epoxy resin are added to the solvent and heated and stirred until they are evenly dispersed. Dispersant and silane coupling agent are added and dispersed and ground to make the particle size reach about 0.3μm. Gravure coating machine is used to evenly coat the substrate film. After drying (first stage 80℃ drying for 30s, second stage 130℃ drying for 45s, third stage 110℃ drying for 30s), an intermediate layer with a thickness of 0.8μm is formed. Ink layer: Acrylic resin, SEBS resin, polyethylene micron wax, and nano-sized titanium dioxide are added to the solvent and heated and stirred until uniformly dispersed. Dispersant, adhesion promoter, and surface-pretreated nano-sized carbon black are added and ground to achieve a particle size of about 0.5μm. Finally, microcapsules are added and dispersed evenly. The mixture is then coated evenly on the intermediate layer using a gravure coating machine and dried (first stage: 80℃ for 30s, second stage: 130℃ for 45s, third stage: 110℃ for 30s) to form an ink layer with a thickness of 1.5μm; thus, the carbon ribbon is obtained.

[0050] The performance test results are as follows: Resolution: The test was conducted using a 600dpi printer. The results showed that the lines were clear and there was no diffusion (the ink droplet diameter was ≤20μm as observed by SEM), which is a significant improvement compared to the 300dpi resolution of traditional ribbons.

[0051] Weather resistance: After 5000 hours of QUV testing, the coating retains 90% of its gloss, with a color difference ΔE value of less than 1.5. Chemical stability: After immersing the ribbon in hydrochloric acid solution with a pH of 1 for 24 hours, the image shows no peeling; after immersing in sodium hydroxide solution with a pH of 13 for 24 hours, the fading rate is less than 4%. Low-temperature performance: After storage at -50℃ for 24 hours, the coating shows no cracks, and the printing resolution remains ≥600 dpi. High-temperature performance: After storage at 150℃ for 24 hours, the ribbon shows no back-sticking, and the printing resolution remains ≥600 dpi.

[0052] After heat transfer printing, the abrasion resistance test showed no scratches on the pattern surface after 500 rubs with an eraser and 100 rubs with alcohol.

[0053] Example 3: A high-resolution thermal transfer ribbon suitable for extreme environments consists of a base film, a weather-resistant back coating applied to one side of the base film, and a chemically resistant intermediate layer and a high-adhesion ink layer sequentially applied to the other side of the base film.

[0054] The chemical corrosion resistant intermediate layer is mainly composed of the following raw materials in the following mass percentages: 33% solvent, 5% silane coupling agent and 2% dispersant, 48% acrylic resin and 12% epoxy resin.

[0055] By weight percentage, the high-adhesion ink layer is mainly composed of 99% ink and 1% microcapsules. The ink is mainly made of the following raw materials by weight percentage: 10% SEBS resin, 10% acrylic resin, 12% polyethylene micro powder wax, 3% nano-grade titanium dioxide, 15% surface pretreatment nano-grade carbon black, 1% dispersant, 4% adhesion promoter, and 45% solvent.

[0056] The weather-resistant back coating is mainly made of the following raw materials in the following weight percentages: 20% fluorocarbon resin, 5% acrylic resin, 65% solvent, 5% H-11 crosslinking weather-resistant agent and 5% silicone filler.

[0057] The above-mentioned method for preparing high-resolution thermal transfer ribbons suitable for extreme environments includes the following steps: The base film was subjected to double-sided corona treatment with a treatment power of 3kW and a film flow rate of 300m / min. The surface of the corona-treated film reached 35dyn / cm². Back coating: Fluorocarbon resin, acrylic resin and silicone filler are added to the solvent and heated and stirred until uniformly dispersed. Crosslinking weather-resistant agent is added and dispersed and ground to make the particle size reach about 0.4μm. Gravure coating machine is used to uniformly coat the back coating on the lower surface of the base film. After drying (first stage 80℃ drying for 30s, second stage 130℃ drying for 45s, third stage 110℃ drying for 30s), a back coating with a thickness of 1.1μm is formed. Intermediate layer: Acrylic resin and epoxy resin are added to the solvent and heated and stirred until they are evenly dispersed. Dispersant and silane coupling agent are added and dispersed and ground to make the particle size reach about 0.3μm. Gravure coating machine is used to evenly coat the substrate film. After drying (first stage 80℃ drying for 30s, second stage 130℃ drying for 45s, third stage 110℃ drying for 30s), an intermediate layer with a thickness of 0.8μm is formed. Ink layer: Acrylic resin, SEBS resin, polyethylene micron wax, and nano-sized titanium dioxide are added to the solvent and heated and stirred until uniformly dispersed. Dispersant, adhesion promoter, and surface-pretreated nano-sized carbon black are added and ground to achieve a particle size of about 0.5μm. Finally, microcapsules are added and dispersed evenly. The mixture is then coated evenly on the intermediate layer using a gravure coating machine and dried (first stage: 80℃ for 30s, second stage: 130℃ for 45s, third stage: 110℃ for 30s) to form an ink layer with a thickness of 1.5μm; thus, the carbon ribbon is obtained.

[0058] The performance test results are as follows: Resolution: The test was conducted using a 600dpi printer. The results showed that the lines were clear and there was no diffusion (the ink droplet diameter was ≤20μm as observed by SEM), which is a significant improvement compared to the 300dpi resolution of traditional ribbons.

[0059] Weather resistance: After 5000 hours of QUV testing, the coating retains 91% of its gloss and has a color difference ΔE value of less than 1.4. Chemical stability: After immersing the ribbon in hydrochloric acid solution with a pH of 1 for 24 hours, the image does not peel off; after immersing in sodium hydroxide solution with a pH of 13 for 24 hours, the fading rate is less than 3%. Low temperature performance: After storage at -50℃ for 24 hours, the coating shows no cracks and the printing resolution remains ≥600dpi; High temperature performance: After storage at 150℃ for 24 hours, the ribbon does not stick back and the printing resolution remains ≥600dpi.

[0060] After heat transfer printing, the abrasion resistance test showed no scratches on the pattern surface after 500 rubs with an eraser and 100 rubs with alcohol.

[0061] The above embodiments only illustrate several implementations of the present invention, and their descriptions are specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A high-resolution thermal transfer ribbon suitable for extreme environments, characterized in that, It consists of a base film, a weather-resistant back coating applied to one side of the base film, and a chemically resistant intermediate layer and an ink layer sequentially applied to the other side of the base film; wherein, the chemically resistant intermediate layer is mainly made of the following raw materials by mass percentage: 20-35% solvent, 1-5% silane coupling agent, 1-5% dispersant, and the balance being resin, wherein the resin is composed of acrylic resin and epoxy resin mixed in a mass ratio of 3:1-5:

1.

2. The high-resolution thermal transfer ribbon for extreme environments according to claim 1, characterized in that, By weight percentage, the ink layer mainly consists of 98-99% ink and 1-2% microcapsules. The ink is mainly made from the following raw materials by weight percentage: 10-15% SEBS resin, 10-15% acrylic resin, 5-15% polyethylene micronized wax, 1-5% nano-grade titanium dioxide, 5-15% surface pretreatment nano-grade carbon black, 0.5%-3% dispersant, 2%-5% adhesion promoter, and the balance being solvent.

3. The high-resolution thermal transfer ribbon for extreme environments according to claim 1, characterized in that, The weather-resistant back coating is mainly made of the following raw materials by weight percentage: 12-30% resin, 1%-5% crosslinking weather-resistant agent, 1-5% silicone filler, and the balance is solvent.

4. The high-resolution thermal transfer ribbon for extreme environments according to claim 1, characterized in that, The nano-sized titanium dioxide particles in the ink layer have a particle size of 1-150 nm, and the nano-sized carbon black particles in the surface pretreatment layer have a particle size of 20-50 nm.

5. The high-resolution thermal transfer ribbon for extreme environments according to claim 1, characterized in that, The surface-pretreated nano-sized carbon black was prepared by the following steps: nano-sized carbon black was mixed with water to obtain a carbon black slurry and the pH was adjusted to 8.0-9.

0. γ-methacryloxypropyltrimethoxysilane was mixed with water to obtain a silane solution. Under an inert gas atmosphere, the two were mixed and stirred at room temperature for 30-60 min. After solid-liquid separation and drying, the carbon black was obtained. The amount of γ-methacryloxypropyltrimethoxysilane added is 2-5% of the mass of carbon black.

6. The high-resolution thermal transfer ribbon for extreme environments according to claim 2, characterized in that, The microcapsules were prepared via the following steps: Sodium dodecylbenzenesulfonate, an emulsifier, and n-butanol, a co-emulsifier, are dissolved in deionized water to prepare an aqueous solution. Under stirring conditions at 25-30°C, the ink is added to the aqueous solution to form an O / W emulsion. The emulsion is transferred to a high-pressure homogenizer, set at 30-40 MPa and 25-30°C, and homogenized 2-3 times until the particle size is stabilized at 0.5±0.05 μm. Then, dimethyl terephthalate, ethylene glycol, the crosslinking monomer hexanediol diacrylate, and the polymerization inhibitor hydroquinone are added. The mixture is stirred at 30-35°C for 30-40 min. Cobalt acetate, a catalyst, is added to the system, and the mixture is heated to 275-290°C for vacuum polycondensation for 2-3 h to obtain the final product. The mass ratio of the emulsifier to the co-emulsifier is 4-6:1; The mass ratio of dimethyl phthalate, ethylene glycol, crosslinking monomer, polymerization inhibitor, and catalyst is 2000:900-1100:80-120:3-7:15-25; The mass ratio of the ink, dimethyl terephthalate, and emulsifier is 100:10-15:2-5.

7. The high-resolution thermal transfer ribbon for extreme environments according to claim 1, characterized in that, The particle size of the silicone filler in the weather-resistant back coating is 0.5-1.2μm; the base film is a polyester film with a thickness of 3.0-4.5μm.

8. The method for preparing a high-resolution thermal transfer ribbon suitable for extreme environments as described in any one of claims 1 to 7, characterized in that, Includes the following steps: 1) Perform double-sided corona treatment on the base film, with a treatment power of 2-5kW and a film flow speed of 200-350m / min; 2) A weather-resistant back coating is applied to the underside of the base film using a gravure coating machine with a coating amount of 0.5-1.5 g / m². The coating is then dried at 80-130℃ to form a weather-resistant back coating with a thickness of 1-2 μm. 3) Using a gravure coating machine, an anti-chemical corrosion intermediate layer is coated on the upper surface of the base film, and the drying temperature is 80-130℃ to form an anti-chemical corrosion intermediate layer with a thickness of 0.5-1.5μm; 4) Using a gravure coating machine, apply an ink layer onto the dried chemically resistant intermediate layer. The drying temperature is 80-130℃ to form an ink layer with a thickness of 1-2μm.

9. The application of the high-resolution thermal transfer ribbon as described in any one of claims 1 to 7, which can be used in extreme environments, in aerospace markings, chemical pipeline labels, and polar scientific research instrument labels.

Images