Photovoltaic glass spacer paper coating and method of making same

Abstract

This invention discloses a photovoltaic glass spacer paper coating and its preparation method, belonging to the field of coating technology. The coating includes an anti-mold layer and a hydrophobic antistatic layer. The anti-mold layer contains an anti-mold agent and a water-based adhesive, effectively inhibiting mold growth. The hydrophobic antistatic layer is composed of a silicon-based precursor, an acidic catalyst, and an antistatic agent. The silicon-based precursor forms a cross-linked network, giving the coating hydrophobic and moisture-proof properties. The antistatic agent is a nano-conductive metal oxide dispersion, which can conduct static electricity and reduce dust adsorption. This dual-layer coating design achieves multiple protective functions of anti-mold, moisture-proof, antistatic, and anti-adhesion, effectively preventing surface contamination and damage to photovoltaic glass during storage and transportation caused by moisture absorption, mold growth, electrostatic adsorption, or coating reactions. This significantly improves the environmental adaptability of the spacer paper and the reliability of photovoltaic glass storage and transportation quality.

Description

Technical Field

[0001] This invention belongs to the field of coating technology, specifically relating to a photovoltaic glass spacer paper coating and its preparation method. Background Technology

[0002] As the core encapsulation material for photovoltaic modules, photovoltaic glass is typically coated with an anti-reflective film to enhance light transmittance and thus improve the photoelectric conversion efficiency of the photovoltaic modules. Throughout the entire process of photovoltaic glass production, storage, transportation, and downstream module encapsulation, interlayer spacers are a crucial technological means to ensure both the glass's appearance and the performance of the film layers. They effectively prevent scratches and abrasions caused by direct contact between glass sheets, while also blocking dust and moisture intrusion, ensuring the cleanliness and integrity of the glass during its handling. Therefore, they are an indispensable supporting material in the photovoltaic glass supply chain.

[0003] Currently, glass spacers (also known as separators or interlayer paper) are commonly used as the physical separation medium between photovoltaic glass layers. These spacers are typically made from bleached chemical wood pulp, possessing a certain strength and flatness, and can act as a buffer, preventing scratches and dust during packaging, handling, and transportation. However, existing glass spacers exhibit several shortcomings when dealing with complex storage and transportation environments. First, their moisture-proof performance is limited. In high-humidity environments or under long-term storage and transportation conditions, the paper easily absorbs moisture, leading to a decrease in its strength, and even softening, deformation, and adhesion to the glass surface, severely affecting the separation and surface integrity of the glass. Second, traditional glass spacers often have wet-strength agents, sizing agents, and other chemical additives added during the papermaking process. Unreacted active groups in these additives or their hydrolysis products in humid environments may chemically react with the anti-reflective coating on the photovoltaic glass surface, causing film corrosion, structural damage, or interface contamination, leading to irreversible damage such as decreased light transmittance and deterioration of optical performance. Finally, in high temperature and high humidity environments, microbial growth may also become a potential problem. If the spacer paper lacks anti-mildew properties, it is very easy for mold to grow during storage and transportation, further contaminating the glass surface and affecting the product's appearance and performance.

[0004] In summary, existing photovoltaic glass spacer paper has significant shortcomings in terms of moisture and mildew prevention, making it difficult to meet the high standards of quality stability required for photovoltaic glass during storage and transportation. Therefore, there is an urgent need to develop a spacer paper coating that combines moisture and mildew prevention to comprehensively improve the environmental adaptability of the spacer paper and ensure the quality reliability of photovoltaic glass under complex storage and transportation conditions. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a photovoltaic glass spacer paper coating and its preparation method.

[0006] The objective of this invention can be achieved through the following technical solutions: A photovoltaic glass spacer coating includes an anti-mildew layer and a hydrophobic antistatic layer.

[0007] Furthermore, the anti-mildew layer comprises the following raw materials by mass fraction: 0.1-2% anti-mildew agent, 0.5-1% water-based adhesive, and the balance being water.

[0008] Furthermore, the hydrophobic antistatic layer comprises the following raw materials by mass fraction: 8-15% silicon source precursor, 3-10% water, 70-85% dispersion medium, 0.004-0.1% acidic catalyst and 0.1-5% antistatic agent.

[0009] Furthermore, the antifungal agent is one of polyhexamethylene biguanide hydrochloride, polyhexamethylene biguanide, and polyhexamethylene guanidine.

[0010] Furthermore, the water-based adhesive is polyvinyl alcohol (PVA), water-based polyurethane (PU), or modified starch.

[0011] Furthermore, the silicon source precursor includes methyltriethoxysilane and tetraethyl orthosilicate.

[0012] Furthermore, the dispersion medium is at least one of ethanol, isopropanol, and n-propanol.

[0013] Furthermore, the acidic catalyst is at least one selected from nitric acid, acetic acid, oxalic acid, and citric acid.

[0014] Furthermore, the antistatic agent is added in the form of a nano-conductive metal oxide dispersion with a mass concentration of 30-60%.

[0015] Furthermore, the nano-conductive metal oxide is one of antimony-doped tin dioxide (ATO), tin-doped indium oxide (ITO), aluminum-doped zinc oxide (AZO), and zinc oxide (ZnO).

[0016] Furthermore, the dispersion medium of the dispersion is at least one selected from water, ethanol, ethylene glycol, and isopropanol.

[0017] A method for preparing a photovoltaic glass spacer paper coating includes the following steps: A1. First, use water as the dispersion medium, then add the antifungal agent and water-based adhesive in sequence. After stirring evenly, a coating liquid is obtained. Apply the liquid evenly to the surface of the spacer paper substrate and dry it to allow the antifungal agent to adhere to the substrate surface and form an antifungal layer. A2. Then, the silicon source precursor, water, dispersion medium, acid catalyst and antistatic agent are thoroughly mixed, the pH is adjusted to 6-7, and the mixture is stirred at high speed and aged to allow partial hydrolysis and pre-reaction, forming a stable coating liquid. This liquid is then evenly coated onto the surface of the anti-mildew layer and cured to allow the surface layer to fully cross-link into a film, forming a hydrophobic and antistatic layer, thus obtaining the photovoltaic glass spacer paper coating.

[0018] Furthermore, the spacer paper substrate is bleached chemical wood pulp paper with a basis weight of 50-60 g / m³. 2 The smoothness is 20-70s.

[0019] Furthermore, the coating method is roller coating, blade coating, dip coating, or spray coating.

[0020] Furthermore, the drying conditions are as follows: drying at 50-100°C for 5-30 minutes.

[0021] Furthermore, the aging time is 240-300 minutes.

[0022] Furthermore, the curing conditions are as follows: curing at 120-150℃ for 5-30 minutes.

[0023] The beneficial effects of this invention are: This invention achieves the following effects through a dual-layer functional design of an anti-mildew layer and a hydrophobic antistatic layer: 1. The anti-mold layer contains an anti-mold agent, which can effectively prevent the growth of mold on photovoltaic glass in high temperature and high humidity storage and transportation environments, and avoid mold stains on the glass surface; 2. The cross-linked network formed by the silicon source precursor in the hydrophobic antistatic layer can reduce the surface energy of the spacer paper, improve its hydrophobicity, and effectively prevent the paper from losing strength, softening and deforming, or sticking to the glass after absorbing moisture. 3. Nano-conductive metal oxides form a conductive network in the coating, which effectively conducts away static electricity, reduces dust adsorption, and avoids the interference of static electricity accumulation on automated wafer picking, cleaning and other processes. In summary, the coating structure of this invention achieves multiple protective functions such as mildew prevention, moisture prevention, antistatic properties, and anti-adhesion, and has significant application value in the field of spacer paper coating. Attached Figure Description

[0024] The invention will now be further described with reference to the accompanying drawings.

[0025] Figure 1 This is a cross-sectional schematic diagram of the coating and its photovoltaic glass spacer obtained in Example 1 of the present invention, wherein 1 is the spacer substrate, 2 is the anti-mildew layer, and 3 is the hydrophobic antistatic layer. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention. Example 1

[0027] A method for preparing a photovoltaic glass spacer paper coating includes the following steps: A1. By mass fraction, mix 98.9% water, 0.5% polyhexamethylene biguanide hydrochloride, and 0.6% polyvinyl alcohol (PVA) water-based adhesive until homogeneous to obtain a coating solution. Apply this solution evenly to a spacer paper substrate (basis weight 50 g / m²). 2 Smoothness is 30s, which is attached. Figure 1 The surface of the spacer paper substrate 1) shown is dried at 80°C for 10 minutes to allow the anti-mildew agent to adhere to the substrate surface and form an adhesive. Figure 1 Anti-mildew layer 2 is shown; A2. By mass fraction, add 4.0% methyltriethoxysilane, 6.0% tetraethyl orthosilicate, 8.0% deionized water, 81.45% ethanol, 0.05% nitric acid, and 0.50% nano-tin-doped indium oxide (ITO) (ITO added as an ethanol dispersion with an average particle size of 20 nm and a mass concentration of 30%). After thorough mixing, adjust the pH to 6.0, stir at high speed, and age for 240 minutes to allow partial hydrolysis and pre-reaction, forming a stable coating liquid. Then, evenly coat the coating liquid onto the surface of the anti-mildew layer and cure at 120°C for 10 minutes to allow the surface layer to completely cross-link and form a film. Figure 1 The hydrophobic antistatic layer 3 shown is used to obtain a photovoltaic glass spacer paper coating. Example 2

[0028] A method for preparing a photovoltaic glass spacer paper coating includes the following steps: A1. By mass fraction, mix 98.2% water, 1.0% polyhexamethylene biguanide hydrochloride mildew inhibitor, and 0.8% modified starch water-based binder (quaternary ammonium cationic etherified starch) evenly to obtain a coating solution. Apply this solution evenly to the spacer paper substrate (basis weight 50 g / m²). 2 The surface with a smoothness of 30s is dried at 90℃ for 10 minutes to fix the anti-mold agent on the substrate surface and form an anti-mold layer. A2. By mass fraction, add 5.0% methyltriethoxysilane, 5.0% tetraethyl orthosilicate, 6.0% deionized water, 83.19% isopropanol as dispersion medium, 0.01% acetic acid, and 0.80% nano-antimony-doped tin dioxide (ATO) (ATO is added in the form of an isopropanol dispersion with an average particle size of 20 nm and a mass concentration of 30%). After thorough mixing, adjust the pH to 7.0, stir at high speed and age for 300 min to allow partial hydrolysis and pre-reaction, forming a stable coating liquid. Then, evenly coat the coating liquid onto the surface of the anti-mildew layer and cure at 120℃ for 10 min to allow the surface layer to completely cross-link into a film, forming a hydrophobic and antistatic layer, thus obtaining the photovoltaic glass spacer paper coating. Example 3

[0029] A method for preparing a photovoltaic glass spacer paper coating includes the following steps: A1. By mass fraction, mix 97.5% water, 1.5% polyhexamethylene biguanide mildew inhibitor, and 1.0% water-based polyurethane (PU) adhesive evenly to obtain a coating solution. Apply this solution evenly to the spacer paper substrate (basis weight 60 g / m²). 2 The surface with a smoothness of 50s is dried at 90℃ for 15 minutes to fix the anti-mold agent on the substrate surface and form an anti-mold layer. A2. By mass fraction, add 10.0% methyltriethoxysilane, 5.0% tetraethyl orthosilicate, 10.0% deionized water, 72.38% ethanol as dispersion medium, 0.12% citric acid, and 2.50% nano-aluminum-doped zinc oxide (AZO) (AZO is added in the form of an ethanol dispersion with an average particle size of 30nm and a mass concentration of 50%). After thorough mixing, adjust the pH to 6.5, stir at high speed and age for 300 minutes to allow partial hydrolysis and pre-reaction, forming a stable coating liquid. Then, evenly coat the coating liquid onto the surface of the anti-mildew layer and cure at 130℃ for 5 minutes to allow the surface layer to completely cross-link into a film, forming a hydrophobic and antistatic layer, thus obtaining the photovoltaic glass spacer paper coating.

[0030] Comparative Example 1 Two antireflective glass films (with both film surfaces facing upwards) were directly stacked as Comparative Example 1.

[0031] Comparative Example 2 As a comparative example 2, a layer of ordinary uncoated glass spacer was placed between two pieces of antireflective glass (with the film surface facing up).

[0032] The coated spacer paper prepared in Examples 1-3 and the ordinary uncoated glass spacer paper in Comparative Example 2 were used as samples to measure their surface resistivity and Cobb water absorption value (Cobb method, GB / T1540). Their anti-mildew properties were then determined according to the following method: A spacer paper of the same size as the glass plane was placed between two clean, dry anti-reflective glass pieces (200mm × 200mm, film side up). The coating of the spacer paper was in contact with the anti-reflective film on the glass below. Two turns of PE plastic wrap were wrapped around each piece, and this was labeled Group A. The same procedure was repeated, and this was labeled Group B. The samples from Groups A and B were placed in a constant temperature and humidity chamber at (60±2)℃ and (90±5)% relative humidity. Group A was stored for 168 hours, and Group B for 400 hours. After the specified storage time, the test samples were removed, the plastic wrap and spacer paper were removed, and the samples were ultrasonically cleaned for 15 minutes. The glass surfaces were then rinsed with a water-filled wash bottle. After cleaning, the surface condition of each glass piece was observed under side lighting. The test result with the highest number among the two anti-mold grades of each group was taken as the anti-mold grade of that group. When observed under side lighting, no mold spots are observed, indicating a mold resistance level of 0; when observed under side lighting, a small number of mold spots (≤5) are observed, indicating a mold resistance level of 1; when observed under side lighting, a small number of mold spots (6-10) are observed, indicating a mold resistance level of 2; when observed under side lighting, a large number of mold spots (>10) are observed, indicating a mold resistance level of 3; when observed under side lighting, the mold appears foggy, indicating a mold resistance level of 4. Finally, the decrease in photovoltaic transmittance of the antireflective films in Examples 1-3 and Comparative Examples 1-2 was measured in the 380-1100 nm wavelength range. Relevant test items and data are shown in Table 1.

[0033] Table 1 As shown in Table 1, the coated spacer paper obtained in this embodiment of the invention exhibits significantly improved antistatic, hydrophobic, and mildew-resistant properties, and provides significant protection for the antireflective film. In summary, the coating of this invention is significantly superior to ordinary spacer paper in terms of antistatic properties, hydrophobicity, mildew resistance, and film protection. It has significant application value in the field of spacer paper coatings.

[0034] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0035] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A photovoltaic glass spacer coating, comprising an anti-mildew layer and a hydrophobic antistatic layer, characterized in that, The hydrophobic antistatic layer comprises the following raw materials by mass fraction: 8-15% silicon source precursor, 3-10% water, 70-85% dispersion medium, 0.004-0.1% acidic catalyst and 0.1-5% antistatic agent.

2. The photovoltaic glass spacer coating according to claim 1, characterized in that, The anti-mildew layer comprises the following raw materials by mass fraction: 0.1-2% anti-mildew agent, 0.5-1% water-based adhesive, and the balance being water.

3. The photovoltaic glass spacer coating according to claim 2, characterized in that, The antifungal agent is one of polyhexamethylene biguanide hydrochloride, polyhexamethylene biguanide, and polyhexamethylene guanidine.

4. The photovoltaic glass spacer coating according to claim 1, characterized in that, The silicon source precursor includes methyltriethoxysilane and tetraethyl orthosilicate.

5. The photovoltaic glass spacer paper coating according to claim 1, characterized in that, The dispersion medium is at least one of ethanol, isopropanol, and n-propanol.

6. The photovoltaic glass spacer coating according to claim 1, characterized in that, The acidic catalyst is at least one of nitric acid, acetic acid, oxalic acid, and citric acid.

7. The photovoltaic glass spacer coating according to claim 1, characterized in that, The antistatic agent is added in the form of a nano-conductive metal oxide dispersion with a mass concentration of 30-60%.

8. The photovoltaic glass spacer coating according to claim 7, characterized in that, The nano-conductive metal oxide is one of antimony-doped tin dioxide (ATO), tin-doped indium oxide (ITO), aluminum-doped zinc oxide (AZO), and zinc oxide (ZnO).

9. A method for preparing a photovoltaic glass spacer coating, characterized in that, The preparation of a photovoltaic glass spacer paper coating according to any one of claims 1-8 includes the following steps: A1. First, use water as the dispersion medium, then add the antifungal agent and water-based adhesive in sequence, stir evenly to obtain the coating liquid, apply it to the surface of the spacer paper substrate, dry it to form an antifungal layer; A2. Then, the silicon source precursor, water, dispersion medium, acid catalyst and antistatic agent are thoroughly mixed, the pH is adjusted to 6-7, and the mixture is stirred at high speed and aged to form a coating liquid. This liquid is then coated on the surface of the anti-mildew layer and cured to form a hydrophobic antistatic layer, thus obtaining the photovoltaic glass spacer paper coating.

10. The method for preparing a photovoltaic glass spacer coating according to claim 9, characterized in that, The spacer paper substrate is bleached chemical wood pulp paper with a basis weight of 50-60 g / m². 2 The smoothness is 20-70s.

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