A lightweight flexible topcon weather-resistant water-resistant pre-film, and a preparation method and application thereof

Abstract

The present application relates to a kind of lightweight flexible Topcon weather-resistant water-blocking front film and its preparation method and application, including the following components: aliphatic polyurethane modified acrylate, fluorine-containing acrylate, phosphorus-containing acrylate, hydroxy acrylate B, initiator, latent polyurethane curing agent, antioxidant, UV absorber, light stabilizer.The front film of the present application reduces the problem of partial coating peeling caused by excessive stress between the water-blocking PET layer for packaging, solves the problem of long-term waterproofing of lightweight flexible photovoltaic modules outdoors.

Description

Technical Field

[0001] The present invention belongs to the technical field of lightweight flexible photovoltaic modules, and in particular relates to a lightweight flexible Topcon weather-resistant and water-blocking front film, a preparation method thereof, and an application thereof. Background Art

[0002] Lightweight flexible photovoltaic modules are lightweight, with a gram weight of <3kg / m 2 , widely used in areas such as factory roofs where weight is limited. With the advancement of cell technology, N-type cells such as Topcon have gradually become mainstream, with advantages in power generation efficiency and raw material sources. Water penetrates between the Al Ag paste in the electrode grid of Topcon cells and the interface of the passivation structure, which will induce electrochemical corrosion. Even PET and PEN with good water resistance have a water resistance of 1~10g / m 2 *d (Infrared method 38℃*90RH%). According to the test results of lightweight flexible Topcon module DH3000, PET should maintain 10~20g / m at least at 85℃ / 85%RH for 3000h. 2 *d water barrier can effectively prevent Topcon batteries from premature aging and reduce power loss due to grid line corrosion.

[0003] The typical method for water-blocking PET for encapsulation is to physically or chemically deposit a nano-AlOx / SiOx metal film on the PET surface, followed by a post-coating treatment. The current problem is that both physical and chemical deposition methods have low surface energy, making corona discharge difficult to achieve without breaking through the coating. Direct pressure bonding using coupling agents and glue can partially address the low surface energy issue, but the intermediate layer has low molecular weight and, consequently, low strength. Furthermore, pure thermosetting resins can delaminate the interface between the coating and the PET under high and low temperature conditions ranging from -40°C to 75°C. Consequently, the reliability of the water-blocking pre-coating is currently limited.

[0004] CN119241785A Jiangsu Xinchengrui Material Technology Co., Ltd. synthesizes a resin containing a coupling agent as a polymer protective layer and adhesive layer to protect the inorganic oxide coating, thereby solving the problem of increased water vapor transmittance after moisture and heat aging. However, its resin is all cured resin. After high and low temperature impact or PCT, the glue may partially peel off the coating and PET, thereby reducing the water barrier performance.

[0005] CN104868003A Hangzhou Foster Photovoltaic Materials Co., Ltd. achieves the purpose of water-blocking and weather-resistant through a three-layer structure of PET-metal foil-weather-resistant coating. However, because the metal film is not light-transmitting, this product cannot be used in Topcon water-blocking front film products. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a lightweight and flexible Topcon weather-resistant and water-blocking front film, as well as its preparation method and application. The front film reduces the problem of partial coating shedding caused by excessive stress between the front film and the water-blocking PET layer used for encapsulation, thereby solving the problem of long-term outdoor waterproofing of lightweight and flexible photovoltaic modules.

[0007] The present invention provides a lightweight, flexible Topcon weather-resistant and water-blocking front membrane, which comprises the following components in parts by mass:

[0008] 70-85 parts of aliphatic polyurethane modified acrylate;

[0009] 3-6 parts of fluorinated acrylate;

[0010] 3-6 parts of phosphorus-containing acrylate;

[0011] 5-10 parts of hydroxy acrylate B;

[0012] 5-10 parts of initiator;

[0013] 5-8 parts of latent polyurethane curing agent;

[0014] 0.5~1 part of antioxidant;

[0015] 0.5~1 part of UV absorber;

[0016] Light stabilizer 0.5~1 part;

[0017] The aliphatic polyurethane-modified acrylate is obtained by reacting polycarbonate diol, polyethylene oxide polyol, caprolactone-modified acrylate, isocyanate and hydroxy acrylate A in a mass ratio of (0.1-1):(0.1-1):(0.1-1):(2-3):(1-2).

[0018] Preferably, the polycarbonate diol is one or more of polycarbonate ethylene diol, polycarbonate-1,6-hexanediol ester diol, and polycarbonate-1,5-pentanediol-1,6-hexanediol ester diol.

[0019] Preferably, the polyoxyethylene polyol is polyoxyethylene triol with trimethylol as the initiator or polyoxyethylene tetraol with pentaerythritol as the initiator.

[0020] Preferably, the isocyanate is one or more of IPDI trimer, HDI trimer, and MDI, preferably IPDI trimer.

[0021] Preferably, the hydroxyacrylate A and hydroxyacrylate B are one or more of hydroxyethyl acrylate and hydroxypropyl acrylate, preferably hydroxyethyl acrylate.

[0022] Preferably, the fluorine-containing acrylate is a fluorine-containing acrylate having 3, 4 or 8 fluorine atoms, preferably a fluorine-containing acrylate having 3 fluorine atoms, which has both reactive activity and hydrophobicity and weather resistance.

[0023] Preferably, the phosphorus-containing acrylate is one or more of diethyl methyl phosphonate, diethyl ethyl phosphate, dimethyl ethyl phosphonate, and diethyl methyl phosphonate, preferably diethyl methyl phosphonate.

[0024] Preferably, the initiator is hydroxyethyl acrylate containing 0.5 wt % to 3 wt % of benzoyl peroxide (BPO).

[0025] Preferably, the antioxidant includes one or more of the hindered phenol antioxidants 1076, 1098, and 1010.

[0026] Preferably, the UV absorber includes one or more of hindered phenol or triazine UV absorbers UV1164, UV1577, and UV400.

[0027] Preferably, the light stabilizer includes one or more of benzotriazole light stabilizers UV1130, UV928, and UV123.

[0028] The present invention also provides a method for preparing a lightweight and flexible Topcon weather-resistant and water-blocking front film, comprising the following steps:

[0029] (1) polycarbonate diol, polyethylene oxide polyol, caprolactone modified acrylate, isocyanate and hydroxy acrylate A are mixed in a mass ratio, a polymerization inhibitor and a catalyst are added, and the temperature is raised to 75-80°C for reaction to obtain aliphatic polyurethane modified acrylate;

[0030] (2) According to the mass ratio, aliphatic polyurethane modified acrylate, fluorine-containing acrylate, phosphorus-containing acrylate, hydroxy acrylate B, initiator, latent polyurethane curing agent, antioxidant, UV absorber and light stabilizer are mixed in an organic solvent, stirred at 60-70° C., and the organic solvent is vacuum-evacuated to obtain the lightweight flexible Topcon weather-resistant and water-blocking front film.

[0031] Preferably, the polymerization inhibitor in step (1) is hydroquinone or p-methoxyphenol, and the amount added is 0.05% to 0.1% of the total mass of the reaction system.

[0032] Preferably, the catalyst in step (1) is an organic tin catalyst, which can be one of dibutyltin dilaurate, stannous octoate, and dibutyltin didodecylsulfide, preferably dibutyltin dilaurate, and the amount added is 0.05% to 0.1% of the total mass of the reaction system.

[0033] Preferably, the organic solvent in step (2) is n-butyl acetate, and the amount added is 40 wt% to 50 wt% of the total mass fraction of the raw materials.

[0034] The present invention also provides an application of a lightweight flexible Topcon weather-resistant and water-blocking front film in a lightweight flexible photovoltaic module.

[0035] Beneficial effects

[0036] (1) The front film of the present invention reduces the problem of partial coating shedding caused by excessive stress between the front film and the water-blocking PET layer used for packaging, thereby solving the problem of long-term outdoor waterproofing of lightweight flexible photovoltaic modules.

[0037] (2) The present invention improves the UV weather resistance of the front film outdoors by adding fluorinated acrylate, while reducing the amount of UV absorber added, thereby increasing the weather resistance of the front film itself and preventing the problem of reduced weather resistance caused by too low a Tg point.

[0038] (3) The present invention improves the adhesion between the front film and the coating by adding phosphorus-containing acrylate.

[0039] (4) The present invention can improve the adhesion stability of the front film after high and low temperature impact and saturated steam test PCT by adding hydroxy acrylate.

[0040] (5) The present invention increases the molecular weight of the product by adding hydroxyethyl acrylate containing benzoyl peroxide (BPO) as an initiator, thereby ensuring the stability of the anti-UV performance.

[0041] (6) The present invention helps to improve the degree of curing between the coating and the coating by adding a latent polyurethane curing agent, so that the adhesion and water resistance are well maintained. DETAILED DESCRIPTION

[0042] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0043] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0044] The preparation method of aliphatic polyurethane modified acrylate is as follows:

[0045] Polycarbonate diol, polyethylene oxide polyol, caprolactone-modified acrylate, isocyanate, and hydroxy acrylate A were mixed according to the mass fractions in Table 1. 0.05% of p-methoxyphenol and 0.1% of dibutyltin dilaurate were added to the mixture. The mixture was heated to 75-80°C for reaction to obtain aliphatic polyurethane-modified acrylate.

[0046] Table 1 Aliphatic polyurethane modified acrylate formula (mass fractions)

[0047]

[0048] Table 2 Lightweight and flexible Topcon weather-resistant and water-blocking front film formula (Example, mass fraction)

[0049]

[0050] Table 3 Lightweight and flexible Topcon weather-resistant and water-blocking front film formula (comparative example, parts by mass)

[0051]

[0052] The preparation method of lightweight and flexible Topcon weather-resistant and water-blocking front membrane is as follows:

[0053] Aliphatic polyurethane-modified acrylate, fluorine-containing acrylate, phosphorus-containing acrylate, hydroxy acrylate B, initiator, latent polyurethane curing agent, antioxidant, UV absorber, and light stabilizer are mixed in n-butyl acetate (accounting for 50wt% of the total mass fraction of the raw materials) in parts by mass, stirred at 60-70°C, and the n-butyl acetate is vacuum-evacuated to obtain the lightweight and flexible Topcon weather-resistant and water-blocking front membrane.

[0054] The test method for lightweight and flexible Topcon weather-resistant and water-blocking front membrane is as follows:

[0055] The front film was evenly applied to the coated side of the PET film and compounded using a continuous roller press to obtain a PET film with a front film; the process parameters of the continuous roller press were: hot pressing at 70°C and 0.2 MPa for 10 minutes, and then hot pressing at 150°C and 0.2 MPa for 20 minutes.

[0056] Table 4 Test results of lightweight and flexible Topcon weather-resistant and water-blocking front membrane performance (Example)

[0057]

[0058] Table 5 Test results of lightweight flexible Topcon weather-resistant and water-blocking front membrane performance (comparative example)

[0059]

[0060] From the above results, it can be seen that:

[0061] 1. Example 2, Comparative Example 1, compared to illustrate that phosphorus-containing acrylate can improve the adhesion of two-layer water-resistant PET. If phosphorus-containing acrylate is not used, the initial adhesion is also low, resulting in easy water ingress between the layers. Under long-term aging, the PET surface is damaged, and the water resistance of the plated layer is poor.

[0062] 2. Example 3, Comparative Example 2, compared to illustrate that hydroxyl acrylate can improve the adhesion stability of the material after high and low temperature impact and PCT.

[0063] 3. Example 3 and Example 4, compared to illustrate that the more the amount of initiator added, the more low molecular weight products, although the initial adhesion is close, but after high and low temperature impact and PCT, the lower the molecular weight, the more the adhesion decreases.

[0064] 4. Example 4 and Comparative Example 3, compared to illustrate that latent polyurethane curing agent helps to improve the curing degree of the adhesive layer, so that the adhesion and water resistance are well maintained.

[0065] 5. Example 4 and Comparative Example 4, compared to illustrate that the addition of initiator can improve the viscosity of the adhesive layer matrix and increase the molecular weight of acrylate, so that the aging performance can be well maintained. Pure isocyanate curing can also be used as an adhesive, but the high and low temperature impact resistance and high temperature and humidity resistance are poor.

[0066] 6. Example 4 and Example 5, compared to illustrate that more latent polyurethane curing agent will increase the overall molecular weight of the product, and the adhesion will be well maintained after high and low temperature and high temperature and humidity. The increase of crosslinking phase will reduce the light transmittance of the material.

[0067] 7. Example 4 and Example 6, compared to illustrate that more caprolactone-modified acrylate improves the flexibility of PUA-1, and the adhesion is general, but the adhesion decreases less after high and low temperature impact.

[0068] 8. Example 5 and Example 7, compared to illustrate that more caprolactone-modified acrylate improves the flexibility of PUA-2, and the adhesion is general, but the adhesion decreases less after high and low temperature impact.

[0069] 9. Example 7 and Example 8, compared to illustrate that the hydroxyl group of polyethylene oxide polyol can improve the adhesion between the plated PET layers.

[0070] 10. Example 4 and Comparative Example 5, compared to illustrate that fluorine-containing acrylate can improve the wet heat resistance of the material. Because the water-repellent performance of F element is excellent, it can improve the hydrolysis resistance of the resin and improve the performance retention of the material after PCT high temperature and humidity.

Claims

1. A lightweight, flexible Topcon weather-resistant, water-blocking front membrane, characterized by: By mass, it includes the following components: The aliphatic polyurethane-modified acrylate is obtained by reacting polycarbonate diol, polyethylene oxide polyol, caprolactone-modified acrylate, isocyanate and hydroxy acrylate A in a mass ratio of (0.1-1):(0.1-1):(0.1-1):(2-3):(1-2); the preparation method comprises: mixing polycarbonate diol, polyethylene oxide polyol, caprolactone-modified acrylate, isocyanate and hydroxy acrylate A in a mass ratio, adding a polymerization inhibitor and a catalyst, heating to 75-80°C for reaction, and obtaining the aliphatic polyurethane-modified acrylate; The fluorine-containing acrylate is a fluorine-containing acrylate with 3, 4 or 8 fluorine atoms; the phosphorus-containing acrylate is one or more of diethyl methyl phosphonate, diethyl ethyl phosphonate, dimethyl ethyl phosphonate and diethyl methyl phosphonate of methacrylate.

2. The lightweight, flexible Topcon weather-resistant, water-blocking front membrane according to claim 1, characterized in that: The polycarbonate diol is one or more of polycarbonate ethylene diol, polycarbonate-1,6-hexanediol ester diol, and polycarbonate-1,5-pentanediol-1,6-hexanediol ester diol.

3. The lightweight, flexible Topcon weather-resistant, water-blocking front membrane according to claim 1, characterized in that: The polyoxyethylene polyol is polyoxyethylene triol with trimethylol as an initiator or polyoxyethylene tetraol with pentaerythritol as an initiator.

4. The lightweight, flexible Topcon weather-resistant, water-blocking front membrane according to claim 1, characterized in that: The isocyanate is one or more of IPDI trimer, HDI trimer and MDI.

5. The lightweight, flexible Topcon weather-resistant, water-blocking front membrane according to claim 1, characterized in that: The hydroxy acrylate A and hydroxy acrylate B are one or more of hydroxy ethyl acrylate and hydroxy propyl acrylate.

6. The lightweight, flexible Topcon weather-resistant, water-blocking front membrane according to claim 1, characterized in that: The initiator is hydroxyethyl acrylate containing 0.5wt% to 3wt% of benzoyl peroxide.

7. The lightweight, flexible Topcon weather-resistant, water-blocking front membrane according to claim 1, characterized in that: The antioxidant includes one or more of the hindered phenol antioxidants 1076, 1098, and 1010; the UV absorber includes one or more of the hindered phenol or triazine UV absorbers UV1164, UV1577, and UV400; and the light stabilizer includes one or more of the benzotriazole light stabilizers UV1130, UV928, and UV123.

8. A method for preparing the lightweight, flexible Topcon weather-resistant, water-blocking front membrane according to any one of claims 1 to 7, comprising the following steps: (1) polycarbonate diol, polyethylene oxide polyol, caprolactone modified acrylate, isocyanate and hydroxy acrylate A are mixed in a mass ratio, a polymerization inhibitor and a catalyst are added, and the temperature is raised to 75-80° C. to react to obtain aliphatic polyurethane modified acrylate; (2) According to the mass ratio, aliphatic polyurethane modified acrylate, fluorine-containing acrylate, phosphorus-containing acrylate, hydroxy acrylate B, initiator, latent polyurethane curing agent, antioxidant, UV absorber and light stabilizer are mixed in an organic solvent, stirred at 60-70° C., and the organic solvent is vacuum-evacuated to obtain the lightweight flexible Topcon weather-resistant and water-blocking front film.

9. Use of the lightweight, flexible Topcon weather-resistant and water-blocking front film according to any one of claims 1 to 7 in a lightweight, flexible photovoltaic module.

Images