Light-transmitting and heat-insulating water-based ink, preparation method and application thereof

Abstract

The application relates to the technical field of high polymer materials, in particular to a light-transmitting and heat-insulating water-based ink as well as a preparation method and application thereof. Steps: S1. Preparing a pre-dispersion liquid: mixing deionized water, an emulsifier, an initiator, a defoaming agent, zirconium acrylate and transparent near-infrared shielding nano-oxide to uniformly disperse, and preparing the pre-dispersion liquid; S2. Preparing a seed emulsion: mixing deionized water, an emulsifier, a pH buffer and at least one polymerization monomer selected from acrylic monomers, acrylate monomers, vinyl ester monomers and acid anhydride monomers to prepare the seed emulsion; S3. Under the protection of inert gas, the seed emulsion prepared in S2 is added into a reaction kettle and heated; then the pre-dispersion liquid prepared in S1 is added dropwise into the reaction system to perform emulsion polymerization reaction, and a hybrid emulsion is prepared; S4. Preparing a water-based ink, and the light-transmitting and heat-insulating water-based ink is prepared. The application has good dispersion stability and storage stability.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a light-transmitting and heat-insulating water-based ink, its preparation method, and its application. Background Technology

[0002] With the development of building energy conservation, transportation energy saving, and lightweight electronic displays and packaging, the demand for coating / ink materials with comprehensive "light transmission + heat insulation" properties is rapidly increasing. "Light transmission and heat insulation" generally refers to materials that maintain high transmittance in the visible light band (approximately 400-700 nm) to ensure visual transparency or graphic presentation, while simultaneously having reflective or absorption shielding capabilities in the near-infrared band (NIR, approximately 780-2500 nm), which significantly contributes heat to solar radiation. This reduces the temperature rise of the coated substrate (glass, plastic film, metal surface, paper, etc.), achieving energy saving and cooling.

[0003] In the ink industry, in addition to traditional colored inks, transparent or light-colored functional inks (such as transparent overprinting, window area printing, functional protective layers, and visual signage) are increasingly taking on the role of "functional coatings." Especially in water-based systems, the requirements for material design and preparation processes are higher than those for low VOCs, safe application, and compliance with environmental regulations, as well as achieving high light transmittance, low haze, water and abrasion resistance, and significant heat insulation effects after film formation.

[0004] The existing technologies for light-transmitting and heat-insulating coatings / inks can be broadly categorized as follows:

[0005] 1. Metal Oxide Transparent Conductive / Heat-Reflective Thin Film Route: Thin films represented by transparent conductive oxides such as ITO can be formed into dense layers through sputtering, evaporation, etc., exhibiting a certain degree of infrared reflectivity while remaining transparent to visible light. This route offers relatively stable thermal insulation performance, but typically relies on vacuum equipment or high-energy deposition processes, resulting in high equipment investment, a narrow process window, and difficulty in adapting to roll-to-roll printing and conventional water-based ink application. Furthermore, it has limitations in adhesion and folding resistance to complex substrates and flexible substrates. Therefore, this route cannot directly meet the low-cost, large-scale demand for a "water-based ink system + conventional printing process."

[0006] 2. Organic Infrared Absorbing Dye / Auxiliary Agent Route: Some organic molecules have the ability to absorb near-infrared radiation, and certain heat insulation or thermal management effects can be achieved by adding infrared absorbers. However, organic absorbing materials often suffer from: insufficient resistance to light and heat aging, easy fading or performance degradation; the absorption mechanism may lead to energy being converted into heat within the film layer, resulting in problems such as "localized heating" and heat accumulation; and compatibility, migration, and long-term stability with waterborne resin systems are difficult to balance. Therefore, the applicability of this route is limited in applications requiring long-term outdoor weather resistance or high transparency.

[0007] 3. Transparent Near-Infrared Shielding Nanomaterial Filling Route: In recent years, materials such as ATO (antimony-doped tin oxide), ITO nanoparticles, and CsxWO3 (cesium tungsten bronze / tungsten oxide) have been widely used in transparent heat-insulating coating systems due to their near-infrared reflection / absorption shielding capabilities and their ability to maintain high visible light transmittance under certain conditions. This route has stronger compatibility with the formulation logic of coatings / inks, and theoretically, a transparent heat-insulating coating film can be formed by directly adding it to an aqueous resin after dispersion.

[0008] However, when introducing the aforementioned nanomaterials into water-based inks using only the "post-addition physical mixing" method, the following problems are still commonly encountered:

[0009] (1) The contradiction between transparency and haze is prominent: If nanoparticles agglomerate, increase in particle size, or form secondary structures, light scattering will increase significantly, leading to increased haze, decreased transparency, and even graying or whitening.

[0010] (2) Insufficient dispersion stability of aqueous systems: The surface charge, ionic strength, pH, and additive system of particles in aqueous media are complex, which can easily induce flocculation, sedimentation or coarsening, resulting in shortened storage period and unstable construction.

[0011] (3) Weak compatibility and interfacial bonding with film-forming resin: If the interfacial bonding between nanoparticles and emulsion polymer is insufficient, micro-phase separation or interfacial voids are likely to occur after film formation, resulting in decreased mechanical properties, insufficient scrub resistance / water resistance, and fluctuations in thermal insulation efficiency.

[0012] (4) Insufficient durability and environmental reliability: Under humid heat, ultraviolet, and cold and heat cycling conditions, nanoparticles may migrate, re-aggregate, or age at the interface, resulting in a decrease in light transmittance and heat insulation performance over time.

[0013] Current Status and Bottlenecks of Waterborne Ink Resin Systems: Commonly used film-forming materials for waterborne inks include waterborne acrylic emulsions, waterborne polyurethane dispersions, and their compounding systems. Among them, waterborne acrylic emulsions have advantages in cost and process maturity, but to achieve "high light transmittance + high heat insulation," the traditional approach is to add functional powders or additives during the ink formulation stage. The key bottleneck of this approach is that there is a lack of "structural binding" between the particle structure of waterborne acrylic emulsions and functional particles, relying more on dispersants and physical embedding; to ensure dispersion stability, a large amount of surfactants or dispersing aids are often required, which may cause problems such as decreased water resistance, foaming, and surface defects; when it is necessary to increase the amount of nanomaterials to enhance NIR shielding, transparency and application stability often deteriorate first, making it difficult for the system to achieve a balance between "heat insulation effect" and "light transmittance appearance." In addition, some applications require coatings with higher refractive index control, hardness, scratch resistance, or adhesion to inorganic / metallic substrates and resistance to damp heat. Traditional acrylic monomer systems mainly adjust film-forming properties by adjusting Tg, particle size, and crosslinking agents, but there is still room for improvement in optical properties (such as refractive index and haze control) and the stability of nanofiller interfaces.

[0014] Therefore, the industry urgently needs a new water-based ink technology solution: under the premise of meeting environmental protection and printability requirements, it is possible to improve the stable existence form and interfacial bonding of transparent NIR shielding nanomaterials in the emulsion system at the material structure level, so as to obtain water-based inks and their preparation methods that have both high transparency and significant heat insulation effect, as well as good storage stability and durability. Summary of the Invention

[0015] The purpose of this invention is to address the problems of existing technologies by grafting / introducing zirconium acrylate and transparent NIR-shielding nano-oxides into an acrylate emulsion via emulsion polymerization to prepare a hybrid emulsion, which in turn allows for the formulation of a water-based ink coating. While meeting environmental protection and printability requirements, this invention enhances the stable existence and interfacial bonding of transparent NIR-shielding nanomaterials in the emulsion system at the material structure level, thereby obtaining a water-based ink with high transparency and significant thermal insulation effects, as well as good storage stability and durability, along with its preparation method and applications.

[0016] To achieve the above objectives, the present invention provides a method for preparing a light-transmitting and heat-insulating water-based ink, comprising the following steps:

[0017] S1. Preparation of pre-dispersion: Deionized water, emulsifier, initiator, defoamer, zirconium acrylate and transparent near-infrared shielding nano-oxide are mixed and dispersed evenly to obtain a pre-dispersion;

[0018] S2. Preparation of seed emulsion: Deionized water, emulsifier, pH buffer and at least one polymerizable monomer selected from acrylic monomers, acrylate monomers, vinyl ester monomers and acid anhydride monomers are mixed to prepare seed emulsion;

[0019] S3. Synthesis of hybrid emulsion: Under inert gas protection, the seed emulsion obtained in step S2 is added to the reaction vessel and heated to 70℃~90℃; the seed emulsion contains all or part of the polymerizable monomers; then, the pre-dispersion liquid (containing an initiator) obtained in step S1 is added to the reaction system dropwise to initiate the emulsion polymerization reaction, and the reaction is maintained for 1~8 hours to obtain the hybrid emulsion;

[0020] S4. Preparation of water-based ink: The hybrid emulsion obtained in S3 is mixed with defoamer, leveling agent, water-based pigment, abrasion resistant agent and deionized water, and dispersed evenly to obtain the light-transmitting and heat-insulating water-based ink.

[0021] In S1, the mass percentage of each component is as follows: deionized water 55.00%~85.00%, emulsifier 1.00%~10.00%, initiator 0.10%~1.00%, defoamer 0.10%~0.50%, zirconium acrylate 7.00%~15.00%, and transparent near-infrared shielding nano-oxide 5.00%~20.00%;

[0022] In S2, the mass percentages of each component are as follows: deionized water 40.00%~60.00%, emulsifier 1.00%~3.00%, pH buffer 0.10%~1.00%, and the total amount of the polymerized monomers is 30.00%~58.00%.

[0023] In S4, the mass percentage of each component is as follows: hybrid emulsion 60.00%~85.00%, defoamer 0.10%~1.00%, leveling agent 0.10%~1.00%, water-based pigment 10.00%~30.00%, abrasion resistant agent 1.00%~5.00%, and deionized water 2.00%~6.00%.

[0024] In step S3, the polymerization temperature is controlled at 70℃~90℃, and the reaction time is 1~8 hours.

[0025] The zirconium content in the zirconium acrylate in S1 is 5wt%~40wt% (calculated as Zr); and the impurity content in the zirconium acrylate meets the following requirements: iron content (calculated as Fe) ≤200 mg / kg, sodium content (calculated as Na) ≤500 mg / kg, and calcium content (calculated as Ca) ≤500 mg / kg.

[0026] The transparent near-infrared shielding nano-oxide in S1 is selected from at least one of ATO (CAS: 128221-48-7), ITO (CAS: 50926-11-9), IZO (CAS: 117944-65-7), GZO (CAS: 52934-06-2), and CsxWO3 (CAS: 189619-69-0).

[0027] The polymerizing monomer may be selected from acrylic monomers, acrylate monomers, vinyl ester monomers, and acid anhydride monomers, and the polymerizing monomer is selected from at least one of the following monomers: acrylic acid, methacrylic acid, dimethylolpropionic acid, dimethylolbutyric acid, hydroxyethyl methacrylate, hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, glycidyl methacrylate, β-hydroxypropyl methacrylate, vinyl acetate, maleic anhydride, itaconic acid, dimethylaminoethyl methacrylate, ethyl acrylate, butyl acrylate, methyl acrylate, methyl methacrylate, and acetylacetoethyl methacrylate.

[0028] The emulsifiers in S1 and S2 are each independently selected from at least one of sodium dodecylbenzenesulfonate (SDBS), polyoxyethylene sorbitan monooleate (Tween 80), polyoxyethylene cetyl ether (Brij 58), alkylphenol polyoxyethylene ether (Triton X-100), polyglycerol monolaurate (PGFE), sodium lauryl ether sulfate (AES), and soybean lecithin (LHP).

[0029] The initiator in S1 is selected from at least one of ammonium persulfate, potassium persulfate, benzoyl peroxide, di-tert-butyl hydroperoxide, azobisisobutyronitrile, and dilauryl peroxide.

[0030] The wear-resistant agent in S4 is an aqueous polyethylene wax emulsion, wherein the laser particle size of the aqueous polyethylene wax emulsion satisfies D50≤0.3μm and D90≤0.6μm, and the sun resistance rating is ≥7 (according to GB / T 250-2008).

[0031] The aqueous pigment paste in S4 is an aqueous concentrate made from at least one pure organic pigment selected from Pigment Red 254, Pigment Red 146, Pigment Red 176, Pigment Red 101, Pigment Yellow 83, Pigment Yellow 150, Pigment Yellow 151, Pigment Yellow 154, Pigment Yellow 43, Pigment Blue 15:3, Pigment Green 7, Pigment Orange 34, Pigment Orange 43, Pigment Orange 64, Pigment Violet 19, and Pigment Violet 23.

[0032] The present invention also provides a light-transmitting and heat-insulating water-based ink, which is prepared by any one of the above methods.

[0033] The present invention also provides an application of the light-transmitting and heat-insulating water-based ink in the printing of transparent heat-insulating coatings, wherein the water-based ink is coated or printed on the surface of a glass substrate or a plastic film substrate.

[0034] The beneficial effects of this invention are as follows:

[0035] 1. In this invention, an emulsion polymerization method of "pre-adding monomers to seed emulsions and adding initiators dropwise with pre-dispersion liquids" is preferred. This method can effectively control the polymerization reaction rate and exothermic process, avoid side reactions or safety risks caused by excessively high local monomer concentrations, and facilitate the in-situ introduction and stable dispersion of nanofunctional components during the polymerization process.

[0036] 2. Balancing high light transmittance and significant heat insulation: While maintaining high transmittance and low haze in the visible light band, it effectively shields the near-infrared band, thereby reducing the temperature rise of the substrate.

[0037] 3. Reduce agglomeration and improve haze: By improving the stable existence of nano-shielding materials in emulsions at the material structure level, light scattering caused by agglomeration is reduced, avoiding graying and whitening.

[0038] 4. Improve the dispersion and storage stability of water-based systems: By grafting and polymerizing the core raw materials into the emulsion, problems such as easy flocculation, sedimentation, and coarsening in water-based media are alleviated, thereby improving storage period and construction stability.

[0039] 5. Enhanced interfacial bonding and overall resistance: Improves the compatibility and interfacial bonding between functional nanomaterials and film-forming resins, thereby enhancing the water resistance, scrub resistance, and mechanical property stability of the film after formation.

[0040] 6. Improved durability and environmental reliability: Under complex conditions such as damp heat, ultraviolet radiation, and thermal cycling, it slows down migration and re-agglomeration and interface aging, reducing the decay of light transmission / heat insulation performance over time.

[0041] 7. While maintaining high visible light transmittance and low haze, this invention has a significant shielding and heat insulation effect in the near-infrared band, and has good dispersion stability, storage stability, water resistance, abrasion resistance and aging resistance. It is suitable for transparent heat insulation coating and printing on substrates such as glass and plastic film.

[0042] 8. This invention achieves structural bonding between functional components and resin through in-situ polymerization, rather than simple physical mixing, thereby significantly improving the system stability and optical performance consistency. Detailed Implementation

[0043] The terms used in this invention, unless otherwise stated, generally have the meanings commonly understood by those skilled in the art.

[0044] The present invention will be further described in detail below with reference to specific embodiments. The following embodiments are only used to illustrate the technical solutions of the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0045] The method for preparing the light-transmitting and heat-insulating water-based ink of the present invention comprises the following steps: The first step is to prepare a pre-dispersion; the second step is to prepare a seed emulsion; the third step is to synthesize a hybrid emulsion; and the fourth step is to prepare the water-based ink. The process conditions for these four steps are as follows:

[0046] Step 1: Pre-dispersion liquid

[0047] A pre-dispersion was prepared by uniformly dispersing deionized water, emulsifier, initiator, defoamer, zirconium acrylate, and transparent NIR shielding nano-oxide at high speed using a homogenizing emulsifier.

[0048] Component mass percentage %

[0049] Deionized water 55.00%~85.00%

[0050] Emulsifier 1.00%~10.00%

[0051] Initiator 0.10%~1.00%

[0052] Defoamer 0.10%~0.50%

[0053] Zirconium acrylate 7.00%~15.00%

[0054] Transparent NIR shielding nano-oxides 5.00%~20.00%

[0055] Step 2: Seed emulsion

[0056] Deionized water, emulsifier, pH buffer, and at least one polymerizable monomer selected from acrylic monomers, acrylate monomers, vinyl ester monomers, and acid anhydride monomers are added to a stirred tank and mixed evenly until a milky white homogeneous solution is obtained, thus preparing the seed emulsion.

[0057] Component mass percentage %

[0058] Deionized water 40.00%~60.00%

[0059] Emulsifier 1.00%~3.00%

[0060] pH buffer 0.10%~1.00%

[0061] Monomer content: 30.00%~58.00%

[0062] Step 3: Hybrid Emulsion

[0063] The seed emulsion obtained in step two is added to an emulsion polymerization apparatus, nitrogen is introduced to purge oxygen, and the temperature is raised to 70°C~90°C; the seed emulsion already contains all or part of the polymerizable monomers. Subsequently, the pre-dispersion obtained in step one is added dropwise to the reaction system to initiate the emulsion polymerization reaction, and the reaction time is controlled to be 1~8 hours. After the reaction is completed, the mixture is cooled and filtered to obtain a hybrid emulsion.

[0064] Step 4: Water-based ink

[0065] The hybrid emulsion, defoamer, leveling agent, water-based pigment, abrasion resistant agent, and deionized water prepared in the third step are mixed, dispersed evenly, and filtered to obtain water-based ink.

[0066] Component mass percentage %

[0067] Hybrid emulsions 60.00%~85.00%

[0068] Defoamer 0.10%~1.00%

[0069] Leveling agent 0.10%~1.00%

[0070] Water-based color paste 10.00%~30.00%

[0071] Wear-resistant agent 1.00%~5.00%

[0072] Deionized water 2.00%~6.00%.

[0073] Example 1

[0074] Step 1: Add the materials in the table below in order, totaling 100g, and simultaneously use a homogenizer at 3000rpm for 3 hours to disperse evenly. Then filter through a 1000-mesh filter to prepare 98g of pre-dispersion liquid.

[0075]

[0076] Step 2: Add 100g of the materials listed in the table below to a beaker and mix at 1500rpm for 45 minutes until a milky white, homogeneous solution is formed and does not separate into layers when left to stand.

[0077]

[0078] Step 3: Pour the 98g seed emulsion from Step 2 into a four-necked flask for emulsion polymerization, purge with nitrogen to purge oxygen, then add the 98g pre-dispersion prepared in Step 1 dropwise into the seed emulsion, while simultaneously heating to 80°C. o C±2 o C, polymerization time 4.5 hours. After the reaction was completed, the mixture was cooled to room temperature and filtered through a 100-mesh filter to obtain 192g of hybrid emulsion.

[0079] Step 4: Add the ingredients listed in the table below, totaling 100g, to a glass beaker. Disperse the mixture at 300 rpm for 10 minutes, then filter through a 100-mesh filter. At 25°C... o The viscosity was measured at room temperature using a Zahn Cup 4# for 15 seconds, and the pH value was measured to be 8.6 using a pH meter.

[0080]

[0081] Test Example 1

[0082] Printing conditions: A coating sampler manufactured by Zhongshan Nuobang was used, with 3μm OSP line bars for coating. The substrate was commercially available glass. A self-prepared, conventional high-transparency, heat-insulating water-based ink was selected as a reference sample. The specific formulation and test results are as follows:

[0083]

[0084] Coating abrasion resistance test [ASTM D4060-25] Solvent resistance test for coatings [ISO 2836:2021] Automotive window sunshade film [GA / T 744-2013] Haze and transmittance test [ASTM D1003] Xenon lamp aging test [ISO 4892-2] Water-based ink coating 1 [Example 1 Scheme] 18 mg / 1000 cycles Solvent resistance rating: Level 5 (no visible change) Total Solar Rejection Rate (TSER) = 62% Light transmittance = 88.5%; Haze = 1.2% Δ transmittance = −1.0%; Δ haze = +0.2% Water-based ink coating 2 [Standard comparison scheme] 42 mg / 1000 cycles Solvent wiping resistance level 3 (slight fogging / marking) Total Solar Rejection Rate (TSER) = 45% Light transmittance = 86.0%; Haze = 2.6% Δ transmittance = −3.5%; Δ haze = +0.8%

[0085] Storage stability test method and results: According to GB / T 6753.3-1986 "Test Method for Storage Stability of Coatings", approximately 90g of the water-based ink prepared in Example 1 was placed in a 100ml plastic bottle, sealed, and then placed in a 50ml container. o After being stored in a constant temperature incubator at 25°C for 30 days, the samples were removed and cooled to room temperature. No visible sedimentation or stratification was observed. o At room temperature, the viscosity was measured to be 15.78 seconds using a Zahn Cup 4#, and the pH value was 8.51, with minimal fluctuation and within the normal range. Using the same testing method and conditions, a self-prepared conventional system, as a reference for the control ink, showed an increase in viscosity from 13.2 seconds to 48.1 seconds and a decrease in pH from 8.8 to 7.9 after heat storage. Furthermore, severe stratification occurred, resulting in a hard precipitate that could not be re-dispersed.

[0086] Under the premise of not significantly sacrificing visible light transmittance, and with the same ATO content, water-based pigment, and abrasion resistant agent, the overall performance of the ink coating 1 (Example 1) is significantly better than that of the ink coating 2 (conventional physical mixing comparison sample). This is mainly reflected in its better abrasion resistance, better solvent resistance, stronger heat insulation effect (higher TSER), better transparency, and higher aging stability (lower haze and smaller changes in light transmittance / haze after aging).

[0087] Example 2

[0088] Step 1: Add the materials in the table below in order, totaling 100g, and simultaneously use a homogenizer at 3000rpm for 3 hours to disperse evenly. Then filter through a 1000-mesh filter to prepare 97g of pre-dispersion liquid.

[0089]

[0090] Step 2: Add 100g of the materials listed in the table below to a beaker and mix at 1800rpm for 55 minutes until a milky white, homogeneous solution is formed and does not separate into layers when left to stand.

[0091]

[0092] Step 3: Pour 100g of the seed emulsion from Step 2 into a four-necked flask for emulsion polymerization, purge with nitrogen to purge oxygen, then add dropwise the 97g of the pre-dispersion prepared in Step 1 to the seed emulsion, while simultaneously raising the temperature to 83°C. o C±2 o C, polymerization time 6.5 hours. After the reaction was completed, the mixture was cooled to room temperature and filtered through a 100-mesh filter to obtain 190g of hybrid emulsion.

[0093] Step 4: Add the ingredients listed in the table below, totaling 100g, to a glass beaker. Disperse the mixture at 300 rpm for 10 minutes, then filter through a 100-mesh filter. At 25°C... o At room temperature, the viscosity was measured to be 14 seconds using a Zahn Cup 4#, and the pH value was measured to be 8.5 using a pH meter.

[0094]

[0095] Test Example 2

[0096] Printing conditions: A coating sampler manufactured by Zhongshan Nuobang was used, with 3μm OSP line bars for coating. The substrate was commercially available glass. A self-prepared, conventional high-transparency, heat-insulating water-based ink was selected as a reference sample. The specific formulation and test results are as follows:

[0097]

[0098] Coating abrasion resistance test [ASTM D4060-25] Solvent resistance test for coatings [ISO 2836:2021] Automotive window sunshade film [GA / T 744-2013] Haze and transmittance test [ASTM D1003] Xenon lamp aging test [ISO 4892-2] Water-based ink coating 3 [Example 2 scheme] 22 mg / 1000 cycles Level 5 (No visible changes) Total Solar Rejection Rate (TSER) = 58% 87.8% / 1.4% Δ transmittance = −1.2%; Δ haze = +0.25% Water-based ink coating 4 [Standard comparison scheme] 48 mg / 1000 cycles Level 3 (Slight fogging / marking) Total Solar Rejection Rate (TSER) = 43% 85.5% / 2.9% Δ transmittance = −3.8%; Δ haze = +0.9%

[0099] Storage stability test method and results: According to GB / T 6753.3-1986 "Test Method for Storage Stability of Coatings", approximately 90g of the water-based ink prepared in Example 2 was placed in a 100ml plastic bottle, sealed, and then placed in a 50ml container. o After being stored in a constant temperature incubator at 25°C for 30 days, the samples were removed and cooled to room temperature. No visible sedimentation or stratification was observed. oAt room temperature, the viscosity was measured using Zahn Cup 4#, and the viscosity was 14.78 seconds. The pH value was measured to be 8.43, with minimal fluctuation, within the normal range. Under the same test methods and conditions, a self-prepared conventional system, as a reference for the control ink, showed an increase in viscosity from 17.3 seconds to 38.7 seconds and a decrease in pH value from 8.6 to 7.8 after heat storage. Furthermore, it exhibited clear stratification, indicating a soft sediment state that could be further dispersed.

[0100] Under the premise of not significantly sacrificing visible light transmittance, the ink coating 3 (Example 2) with the same IZO content, water-based pigment, and abrasion resistant agent has significantly better overall performance than the ink coating 4 (conventional physical mixing comparison sample). This is mainly reflected in better abrasion resistance, better solvent resistance, stronger heat insulation effect (higher TSER), better transparency, and higher aging stability (lower haze and smaller changes in light transmittance / haze after aging).

[0101] The above is a detailed description of the embodiments, which is intended to enable those skilled in the art to correctly understand and use the present invention. Any improvements or modifications to technical solutions obtained by those skilled in the art based on the present invention and on the existing technology, without innovative effort but only through analysis, analogy, or limited enumeration, should be within the scope of protection defined by the claims.

Claims

1. A method for preparing a light-transmitting and heat-insulating water-based ink, characterized in that, Includes the following steps: S1. Preparation of pre-dispersion: Deionized water, emulsifier, initiator, defoamer, zirconium acrylate and transparent near-infrared shielding nano-oxide are mixed and dispersed evenly to obtain a pre-dispersion; S2. Preparation of seed emulsion: Deionized water, emulsifier, pH buffer and at least one polymerizable monomer selected from acrylic monomers, acrylate monomers, vinyl ester monomers and acid anhydride monomers are mixed to prepare seed emulsion; S3. Synthesis of hybrid emulsion: Under inert gas protection, the seed emulsion obtained in step S2 is added to the reactor and heated to 70℃~90℃; then, the pre-dispersion obtained in step S1 is added to the reaction system dropwise to initiate the emulsion polymerization reaction and maintain the reaction for 1~8 hours to obtain the hybrid emulsion. S4. Preparation of water-based ink: The hybrid emulsion obtained in S3 is mixed with defoamer, leveling agent, water-based pigment, abrasion resistant agent and deionized water, and dispersed evenly to obtain the light-transmitting and heat-insulating water-based ink.

2. The method according to claim 1, characterized in that, In S1, the mass percentage of each component is as follows: deionized water 55.00%~85.00%, emulsifier 1.00%~10.00%, initiator 0.10%~1.00%, defoamer 0.10%~0.50%, zirconium acrylate 7.00%~15.00%, and transparent near-infrared shielding nano-oxide 5.00%~20.00%; In S2, the mass percentages of each component are as follows: deionized water 40.00%~60.00%, emulsifier 1.00%~3.00%, pH buffer 0.10%~1.00%, and the total amount of the polymerized monomers is 30.00%~58.00%. In S4, the mass percentage of each component is as follows: hybrid emulsion 60.00%~85.00%, defoamer 0.10%~1.00%, leveling agent 0.10%~1.00%, water-based pigment 10.00%~30.00%, abrasion resistant agent 1.00%~5.00%, and deionized water 2.00%~6.00%.

3. The method according to claim 1, characterized in that, In step S3, the polymerization temperature is controlled at 70℃~90℃, and the reaction time is 1~8 hours.

4. The method according to claim 1, characterized in that, The zirconium content in the zirconium acrylate in S1 is 5wt%~40wt% (calculated as Zr); and the impurity content in the zirconium acrylate meets the following requirements: iron content (calculated as Fe) ≤200 mg / kg, sodium content (calculated as Na) ≤500 mg / kg, and calcium content (calculated as Ca) ≤500 mg / kg. The transparent near-infrared shielding nano-oxide in S1 is selected from at least one of ATO, ITO, IZO, GZO, and CsxWO3.

5. The method according to claim 1, characterized in that, The polymerizable monomer is selected from at least one of the following monomers: acrylic acid, methacrylic acid, hydroxyethyl methacrylate, hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, glycidyl methacrylate, β-hydroxypropyl methacrylate, vinyl acetate, maleic anhydride, dimethylaminoethyl methacrylate, ethyl acrylate, butyl acrylate, methyl acrylate, methyl methacrylate, and acetylacetoethyl methacrylate.

6. The method according to claim 1, characterized in that, The emulsifiers in S1 and S2 are each independently selected from at least one of sodium dodecylbenzenesulfonate, polyoxyethylene sorbitan monooleate, polyoxyethylene cetyl ether, alkylphenol polyoxyethylene ether, decaglycerol monolaurate, sodium lauryl ether sulfate, and soybean lecithin. The initiator in S1 is selected from at least one of ammonium persulfate, potassium persulfate, benzoyl peroxide, di-tert-butyl hydroperoxide, azobisisobutyronitrile, and dilauryl peroxide.

7. The method according to claim 1, characterized in that, The wear-resistant agent in S4 is an aqueous polyethylene wax emulsion, wherein the laser particle size of the aqueous polyethylene wax emulsion satisfies D50≤0.3μm and D90≤0.6μm, and the sun resistance rating is ≥7. The aqueous pigment paste in S4 is an aqueous concentrate made from at least one pure organic pigment selected from Pigment Red 254, Pigment Red 146, Pigment Red 176, Pigment Red 101, Pigment Yellow 83, Pigment Yellow 150, Pigment Yellow 151, Pigment Yellow 154, Pigment Yellow 43, Pigment Blue 15:3, Pigment Green 7, Pigment Orange 34, Pigment Orange 43, Pigment Orange 64, Pigment Violet 19, and Pigment Violet 23.

8. A light-transmitting and heat-insulating water-based ink, characterized in that, It is prepared by any one of the preparation methods described in claims 1 to 7.

9. The application of a water-based ink for light transmission and heat insulation as described in claim 8 in the printing of a transparent heat-insulating coating, characterized in that, The water-based ink is applied or printed onto the surface of a glass substrate or a plastic film substrate.

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