Preparation process of environment-friendly high-reflectivity photovoltaic backboard glass coating ink

Abstract

The invention relates to the technical field of preparation of photovoltaic backboard glass coating ink, and discloses a preparation process of environment-friendly high-reflectivity photovoltaic backboard glass coating ink, which comprises the following steps: preparing a glass flux; preparing functional whitening powder; preparing water-soluble varnish; the invention relates to ink mixing preparation and coating application. The method is simple and convenient in technological process, stable in operation, reasonable in cost control and convenient to popularize and apply in the photovoltaic industry, and performance improvement and industrial upgrading of the photovoltaic module are promoted. In the future, along with continuous attention to green energy and continuous development of an efficient photovoltaic technology, the coating material and the process provided by the invention can provide powerful technical support for the photovoltaic industry, assist in realizing green transformation and sustainable development targets of an energy structure, and make a positive contribution to global new energy undertaking.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic backplane glass coating ink preparation, and in particular to a preparation process of an environmentally friendly high-reflectivity photovoltaic backplane glass coating ink. Background Art

[0002] With the global energy transition and growing awareness of environmental protection, photovoltaic power generation, as a clean, renewable energy technology, has garnered widespread attention and rapid development. As core components of photovoltaic systems, the performance and stability of photovoltaic modules directly impact the power generation efficiency and service life of photovoltaic power plants. As a crucial component of photovoltaic modules, photovoltaic backsheet glass not only provides mechanical protection but also significantly impacts light reflection and utilization efficiency. Therefore, developing photovoltaic backsheet coating materials with high reflectivity, excellent weather resistance, and environmentally friendly properties is a key approach to improving the overall performance of photovoltaic modules.

[0003] Existing photovoltaic backsheet coating technologies mostly utilize organic solvent-based inks or simple inorganic coatings, which suffer from low reflectivity, poor adhesion, insufficient weather resistance, and environmental pollution. On the one hand, the reflectivity of traditional coating materials often fails to meet the optical performance requirements of high-efficiency photovoltaic modules, limiting the utilization of light energy. On the other hand, coatings are prone to degradation such as blistering, flaking, and discoloration during long-term outdoor use, affecting the stability and lifespan of photovoltaic modules. Furthermore, the organic solvents used in many coating preparation processes evaporate, generating large amounts of VOCs (volatile organic compounds), which pose potential hazards to the environment and human health, and are inconsistent with current trends in green manufacturing and sustainable development.

[0004] In recent years, with the advancement of melting technology and nano-surface modification techniques for inorganic non-metallic mineral materials, the use of high-reflectivity functional whitening powders and environmentally friendly water-based resin systems has become a research hotspot. By rationally designing glass flux formulations, optimizing the particle size and surface coating structure of the functional whitening powders, and employing water-based varnish systems, the optical properties and weather resistance of coatings can be effectively improved while simultaneously reducing environmental pollution and achieving environmental sustainability. However, current related technologies still face challenges such as uneven powder dispersion, insufficient coating adhesion, and complex processes that hinder scalability, limiting their widespread application in photovoltaic backsheets.

[0005] Therefore, there is an urgent need for a simple, environmentally friendly, efficient, and high-performance technology for preparing high-reflectivity photovoltaic backplane glass coating inks that can meet the needs of long-term stable operation of photovoltaic modules while also taking into account environmental protection and the feasibility of industrial production. This is precisely the technical problem to be solved by the present invention. Summary of the Invention

[0006] (1) Technical problems solved

[0007] In view of the deficiencies in the prior art, the present invention provides a process for preparing an environmentally friendly high-reflectivity photovoltaic backplane glass coating ink to solve the above problems.

[0008] (2) Technical solution

[0009] To achieve the above object, the present invention provides the following technical solution: a process for preparing an environmentally friendly high-reflectivity photovoltaic backplane glass coating ink, comprising the following steps:

[0010] (1) Preparation of glass flux: Mix various inorganic non-metallic minerals and chemical raw materials in a predetermined proportion, melt them at high temperature in a converter, quench them in water, and then grind them into fine powder;

[0011] (2) Preparation of functional whitening powder: titanium dioxide is used for surface modification to form a functional whitening powder with high reflectivity, excellent hiding power, weather resistance and anti-PID performance;

[0012] (3) Preparation of water-soluble varnish: using high molecular weight environmentally friendly resin and aqueous solvent as the main components, adding dispersants, defoamers, leveling agents, thickeners, curing agents and other additives;

[0013] (4) Ink mixing preparation: glass flux powder and functional whitening powder are mixed in a certain proportion, water-soluble varnish is added, and the mixture is dispersed using a high-speed disperser, and then ground using a three-roll mill to obtain a finished coating ink product;

[0014] (5) Coating application: The prepared ink is applied to the surface of the double-glass photovoltaic backplane glass, and after pre-drying and tempering treatment, a functional coating with high adhesion and high reflectivity is formed.

[0015] As a preferred technical solution of the present invention, the inorganic non-metallic minerals in step (1) include silicon dioxide, boron oxide, sodium oxide, potassium oxide and aluminum oxide, the melting temperature is controlled at 900°C to 1200°C, preferably 950°C to 1100°C, and the glass flux powder after grinding in step (1) has a D50 particle size of less than 10 μm, preferably 5 μm to 8 μm.

[0016] As a preferred technical solution of the present invention, the surface modification treatment of titanium dioxide in step (2) adopts metal oxide coating technology, the coating material is selected from aluminum oxide or zirconium oxide, the coating layer thickness is 5nm to 15nm, the particle size of titanium dioxide in step (2) is controlled in the range of 200nm to 300nm, and the hiding power index is greater than 30.

[0017] As a preferred technical solution of the present invention, the polymer environmentally friendly resin in step (3) is selected from acrylic resin or polyurethane resin, and the resin content is 20wt% to 35wt%; the amount of dispersant in step (3) is 0.5wt% to 2wt%, and the total amount of defoaming agent and leveling agent does not exceed 3wt%.

[0018] As a preferred technical solution of the present invention, the mass ratio of the glass flux powder to the functional whitening powder in step (4) is 30:70 to 70:30, preferably 40:60 to 60:40; the dispersion speed of the high-speed disperser in step (4) is 2000 rpm to 4000 rpm, and the dispersion time is not less than 30 minutes; the grinding gap of the three-roll grinder in step (4) is adjusted between 10 μm and 20 μm, and the number of grinding times is 3 to 5 times.

[0019] As a preferred technical solution of the present invention, the pre-drying temperature in step (5) is 120°C to 140°C, and the pre-drying time is 5 minutes to 10 minutes; the tempering treatment temperature in step (5) is controlled at 600°C to 650°C, and the tempering time is 10 minutes to 20 minutes; the thickness of the coating formed in step (5) is controlled in the range of 20 μm to 50 μm.

[0020] As a preferred technical solution of the present invention, the reflectivity of the prepared coating ink is not less than 88%, the glossiness reaches above 60GU, and the coating adhesion grade reaches level 0 of the ISO 2409 standard.

[0021] As the preferred technical solution of the present invention, the prepared coating ink passes the 1000-hour damp heat test and UV aging test, has excellent anti-PID performance, and meets the 25-year service life requirement of photovoltaic modules.

[0022] Compared with the prior art, the present invention provides a preparation process for an environmentally friendly high-reflectivity photovoltaic backplane glass coating ink, which has the following beneficial effects:

[0023] High reflectivity and excellent optical properties are achieved through the use of special glass flux powder and functional whitening powder, combined with scientific ratios and process control. The resulting coating has a reflectivity exceeding 88%, with some examples exceeding 92%, far exceeding that of traditional coatings. This significantly enhances the reflectivity of the photovoltaic backsheet, effectively improving light utilization and thus the power generation efficiency of the photovoltaic module.

[0024] Excellent adhesion and weather resistance: Surface-modified titanium dioxide and high-performance water-based resin, combined with a comprehensive additive system, ensure the coating's exceptional adhesion, reaching ISO 2409 Class 0. The coating also exhibits excellent resistance to heat and humidity, UV aging, and PID, enabling it to operate stably for extended periods in complex outdoor environments, ensuring the long-term reliability of photovoltaic modules.

[0025] Environmentally friendly, safe, and compliant with green manufacturing requirements, this process utilizes a water-based varnish system, avoiding the use of organic solvents and reducing VOC (volatile organic compound) emissions, complying with national environmental protection policies. The raw materials used are primarily inorganic non-metallic minerals and environmentally friendly resins, resulting in a green, low-pollution production process that aligns with the industry's sustainable development trends.

[0026] The present invention's preparation process is scientifically and rationally designed, encompassing the steps of fine grinding, dispersion, grinding, and coating of the powder. It is simple to operate, requires minimal equipment, and is readily adaptable to large-scale industrial production. Furthermore, the process parameters are highly stable and repeatable, facilitating stable and consistent production.

[0027] Significantly improve the service life of photovoltaic backsheets. After rigorous aging tests such as humidity, heat, and UV aging, the coating still maintains excellent performance under environmental simulation conditions for more than 1,000 hours, without blistering, shedding, or discoloration. This ensures the stable performance of photovoltaic modules within a service life of more than 25 years, greatly improving the overall economy and reliability of the photovoltaic system.

[0028] Broad Application Prospects: The coating of this invention is suitable for all types of photovoltaic backplane glass, particularly for photovoltaic power generation systems with stringent requirements for high reflectivity, environmental friendliness, and weather resistance, contributing to the green development of the photovoltaic industry. Its excellent performance also provides a solid material foundation for emerging applications such as smart photovoltaics and building-integrated photovoltaics.

[0029] In summary, this invention successfully produces a photovoltaic backsheet glass coating ink with high reflectivity, excellent adhesion, and outstanding weather resistance through the innovative combination of high-temperature melting technology for inorganic non-metallic minerals, an advanced coating process for surface-modified titanium dioxide, and an environmentally friendly water-based varnish system. This technical solution not only significantly improves the optical performance and service life of photovoltaic backsheets, but also fully considers environmental protection and sustainable development requirements, promising broad market application prospects.

[0030] Furthermore, the present invention's simple process, stable operation, and reasonable cost control facilitate its widespread application in the photovoltaic industry, driving performance improvements and industrial upgrades for photovoltaic modules. In the future, with the increasing emphasis on green energy and the continuous development of high-efficiency photovoltaic technology, the coating material and process of the present invention will provide strong technical support for the photovoltaic industry, helping to achieve the green transformation of energy structure and sustainable development goals, and making a positive contribution to the global new energy industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of the preparation method of the present invention. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Obviously, the embodiments described are only some embodiments of the invention, not all embodiments. In the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. Based on the embodiments of the invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the invention.

[0033] In addition, "multiple" means more than two. Furthermore, the technical solutions of the various embodiments may be combined with each other, but this must be based on the premise that they can be implemented by a person of ordinary skill in the art. If the combination of technical solutions is mutually inconsistent or cannot be implemented, it shall be deemed that such combination of technical solutions does not exist and is not within the scope of protection claimed in the invention.

[0034] See also Figure 1 :

[0035] Example 1

[0036] This embodiment provides a process for preparing an environmentally friendly high-reflectivity photovoltaic backplane glass coating ink, and the specific steps are as follows:

[0037] (1) Preparation of glass flux

[0038] 45wt% silicon dioxide, 15wt% boron oxide, 12wt% sodium oxide, 8wt% potassium oxide, and 20wt% aluminum oxide were weighed and mixed uniformly, then melted in a converter at 1050°C for 2 hours. Once the molten material became transparent and homogeneous, it was quickly poured into cold water for quenching to produce a glass frit. The glass frit was then crushed and ground in a ball mill for 24 hours to obtain a glass flux powder with a D50 particle size of 6.5μm.

[0039] (2) Preparation of functional whitening powder

[0040] Rutile titanium dioxide with a particle size of 250nm was used. Alumina coating technology was used to modify the titanium dioxide surface: the titanium dioxide was dispersed in deionized water, the pH was adjusted to 8-9, and aluminum sulfate solution was slowly added dropwise. The reaction temperature was controlled at 60°C. After reacting for 2 hours, the product was filtered, washed, and dried to obtain a functional whitening powder with an alumina coating layer 10nm thick. Testing showed that this functional whitening powder had a hiding power index of 35.

[0041] (3) Preparation of water-soluble varnish

[0042] Dissolve 28wt% of acrylic resin in deionized water. Add 1.2wt% of dispersant (sodium polyacrylate), 0.8wt% of defoamer, 1.0wt% of leveling agent, and 0.5wt% of thickener. Stir at 40°C for 30 minutes to fully dissolve and mix. Finally, add 2wt% of curing agent and continue stirring for 15 minutes to obtain a water-soluble varnish.

[0043] (4) Mixing and preparation of ink

[0044] Mix glass flux powder and functional whitening powder in a 50:50 mass ratio. Add the aforementioned water-soluble varnish to a solids content of 65%. Use a high-speed disperser at 3000 rpm for 45 minutes to ensure thorough dispersion. Then, grind the dispersed slurry on a three-roll mill with a grinding gap set at 15 μm for four passes to obtain a finished coating ink with a fineness of ≤15 μm.

[0045] (5) Coating application

[0046] The ink is evenly applied to the double-glazed photovoltaic backplane glass using screen printing, with a coating thickness of 35μm. The coated glass is pre-dried at 130°C for 8 minutes, then tempered in a tempering furnace at 625°C for 15 minutes. After cooling, the resulting photovoltaic backplane glass features a high-reflectivity functional coating.

[0047] Performance test results: Coating reflectivity: 90.5%; Gloss: 65 GU; Adhesion: ISO 2409 standard level 0; 1000-hour humidity and heat test: no blistering or peeling; UV aging test: color difference ΔE<2.

[0048] Example 2

[0049] The difference between this embodiment and embodiment 1 is that:

[0050] (1) The glass flux composition was adjusted to: 40 wt% silicon dioxide, 18 wt% boron oxide, 10 wt% sodium oxide, 10 wt% potassium oxide, and 22 wt% aluminum oxide. The melting temperature was 980 °C, and the D50 particle size after grinding was 7.8 μm.

[0051] (2) The functional whitening powder is coated with zirconium oxide, the coating thickness is 12nm, and the titanium dioxide particle size is 280nm.

[0052] (3) The water-soluble varnish is made of polyurethane resin with a resin content of 32 wt% and a dispersant dosage of 1.5 wt%.

[0053] (4) The mass ratio of glass flux powder to functional whitening powder is 40:60, the high-speed dispersion speed is 3500 rpm, the three-roll grinding gap is 12 μm, and the grinding is performed 5 times.

[0054] (5) The coating thickness is controlled at 40 μm, the pre-drying temperature is 125 ° C, the time is 10 minutes; the tempering temperature is 640 ° C, the time is 12 minutes.

[0055] Performance test results: coating reflectivity: 92.3%; gloss: 68 GU; adhesion: ISO 2409 standard level 0.

[0056] Example 3

[0057] The difference between this embodiment and embodiment 1 is that:

[0058] (1) The melting temperature was raised to 1100°C, and the D50 particle size after grinding was controlled at 5 μm.

[0059] (2) The particle size of titanium dioxide is 200nm, the thickness of the alumina coating is 15nm, and the hiding power index reaches 38.

[0060] (3) The acrylic resin content is reduced to 25wt%, and the total amount of defoamer and leveling agent is 2.5wt%.

[0061] (4) The mass ratio of glass flux powder to functional whitening powder is 60:40, the dispersion speed is 2500 rpm, and the grinding gap is 18 μm.

[0062] (5) The coating thickness is 25 μm, the pre-drying temperature is 140 °C, and the tempering temperature is 610 °C.

[0063] Performance test results: coating reflectivity: 88.8%; gloss: 62 GU; adhesion: ISO 2409 standard level 0.

[0064] Comparative Example 1

[0065] A traditional solvent-based ink system was used, and no titanium dioxide surface modification treatment was performed. Other conditions were the same as in Example 1.

[0066] Performance test results: Coating reflectivity: 82.5%; Gloss: 55 GU; Adhesion: ISO 2409 standard Level 1; 1000-hour damp heat test: slight bubbling occurred.

[0067] It can be seen from the above embodiments that the environmentally friendly high-reflectivity photovoltaic backplane glass coating ink preparation process provided by the present invention optimizes key technologies such as glass flux composition, surface modification of functional whitening powder, and water-soluble varnish formulation. The prepared coating has excellent reflectivity, adhesion and weather resistance, fully meets the 25-year service life requirement of photovoltaic modules, and has good application prospects.

[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0069] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0070] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A process for preparing an environmentally friendly high-reflectivity photovoltaic backplane glass coating ink, characterized in that: The following steps are involved: (1) Preparation of glass flux: Mix various inorganic non-metallic minerals and chemical raw materials in a predetermined proportion, melt them at high temperature in a converter, quench them in water, and then grind them into fine powder; (2) Preparation of functional whitening powder: titanium dioxide is used for surface modification to form a functional whitening powder with high reflectivity, excellent hiding power, weather resistance and anti-PID performance; (3) Preparation of water-soluble varnish: using high molecular weight environmentally friendly resin and aqueous solvent as the main components, adding dispersants, defoamers, leveling agents, thickeners and curing agents; (4) Ink mixing preparation: glass flux powder and functional whitening powder are mixed in a certain proportion, water-soluble varnish is added, and the mixture is dispersed using a high-speed disperser, and then ground using a three-roll mill to obtain a finished coating ink product; (5) Coating application: The prepared ink is applied to the surface of the double-glass photovoltaic backplane glass, and after pre-drying and tempering treatment, a functional coating with high adhesion and high reflectivity is formed.

2. The process for preparing an environmentally friendly high-reflectivity photovoltaic backsheet glass coating ink according to claim 1, characterized in that: The inorganic non-metallic minerals in step (1) include silicon dioxide, boron oxide, sodium oxide, potassium oxide and aluminum oxide, and the melting temperature is controlled at 900°C to 1200°C, preferably 950°C to 1100°C. The glass flux powder after grinding in step (1) has a D50 particle size of less than 10 μm, preferably 5 μm to 8 μm.

3. The process for preparing an environmentally friendly high-reflectivity photovoltaic backsheet glass coating ink according to claim 1, characterized in that: In step (2), the surface modification treatment of titanium dioxide adopts metal oxide coating technology, the coating material is selected from aluminum oxide or zirconium oxide, the coating layer thickness is 5nm to 15nm, the particle size of titanium dioxide in step (2) is controlled in the range of 200nm to 300nm, and the hiding power index is greater than 30.

4. The process for preparing an environmentally friendly high-reflectivity photovoltaic backsheet glass coating ink according to claim 1, characterized in that: In step (3), the polymer environmentally friendly resin is selected from acrylic resin or polyurethane resin, and the resin content is 20wt% to 35wt%; the amount of dispersant used in step (3) is 0.5wt% to 2wt%, and the total amount of defoaming agent and leveling agent does not exceed 3wt%.

5. The process for preparing an environmentally friendly high-reflectivity photovoltaic backsheet glass coating ink according to claim 1, characterized in that: In step (4), the mass ratio of the glass flux powder to the functional whitening powder is 30:70 to 70:30, preferably 40:60 to 60:40; the dispersion speed of the high-speed disperser in step (4) is 2000 rpm to 4000 rpm, and the dispersion time is not less than 30 minutes; the grinding gap of the three-roll grinder in step (4) is adjusted between 10 μm and 20 μm, and the number of grinding times is 3 to 5 times.

6. The process for preparing an environmentally friendly high-reflectivity photovoltaic backsheet glass coating ink according to claim 1, characterized in that: In step (5), the pre-drying temperature is 120° C. to 140° C., and the pre-drying time is 5 minutes to 10 minutes; in step (5), the tempering treatment temperature is controlled at 600° C. to 650° C., and the tempering time is 10 minutes to 20 minutes; and the thickness of the coating formed in step (5) is controlled within the range of 20 μm to 50 μm.

7. The process for preparing an environmentally friendly high-reflectivity photovoltaic backsheet glass coating ink according to claim 1, characterized in that: The reflectivity of the prepared coating ink is not less than 88%, the glossiness reaches above 60 GU, and the coating adhesion grade reaches grade 0 of the ISO 2409 standard.

8. The process for preparing an environmentally friendly high-reflectivity photovoltaic backsheet glass coating ink according to claim 1, characterized in that: The prepared coating ink passed the 1000-hour damp heat test and UV aging test, has excellent anti-PID performance, and meets the 25-year service life requirement of photovoltaic modules.

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