Adhesive layer composition, battery piece with protective adhesive layer and insulating adhesive layer, and photovoltaic module

Abstract

The invention provides a group of adhesive layer compositions, a battery piece with a protective adhesive layer and an insulating adhesive layer, and a photovoltaic module. The adhesive layer composition comprises a protective adhesive layer composition and an insulating adhesive layer composition, wherein the protective adhesive layer composition comprises UV curing release resin, a monomer and a photoinitiator; the insulating adhesive layer composition comprises epoxy resin and a curing agent. The UV-cured release resin disclosed by the invention still keeps stable at high temperature, is not easy to soften, has a relatively good anti-sticking effect, and is not easy to adhere to other resins. The epoxy resin in the insulating adhesive layer composition has a good insulating effect, and has high stability at high temperature. And the UV curing release resin in the protective adhesive layer composition is matched with the epoxy resin in the insulating adhesive layer composition for use, so that the bonding force of the protective adhesive layer and the insulating adhesive layer after being pressed and at high temperature is further reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic modules, in particular to a set of adhesive layer compositions, a cell with protective adhesive layer and insulating adhesive layer, and a photovoltaic module. BACKGROUND

[0002] In the manufacturing process of back contact (BC) cells, the front surfaces of the BC cells are prone to be scratched when stacked together. The existing solution strategy relies on the use of release paper or other physical isolation materials to avoid contact between the front surfaces and prevent scratching, but this not only increases the manufacturing cost, but also may introduce additional production process complexity.

[0003] In the prior art, the problem of the BC cells being prone to be scratched when stacked together is solved by coating a protective adhesive on the front surface and an insulating adhesive on the back surface of the BC cells. The protective adhesive and the insulating adhesive use polyurethane acrylate, epoxy acrylate and other polymers as the system, which is not resistant to high temperature. However, the BC cells need to undergo high-temperature passivation treatment, and therefore, the BC cells are prone to be bonded after the high-temperature passivation treatment, which seriously hinders the efficient flow and yield improvement of the BC cells in the manufacturing process. SUMMARY

[0004] The main purpose of the present application is to provide a set of adhesive layer compositions, a cell with protective adhesive layer and insulating adhesive layer, and a photovoltaic module, to solve the problem that the protective adhesive layer and the insulating adhesive layer on the stacked cells are prone to be bonded after being pressed and subjected to high temperature in the prior art.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a set of adhesive layer compositions is provided, which includes a protective adhesive layer composition and an insulating adhesive layer composition. The protective adhesive layer composition includes a UV-curable release resin, a monomer and a photoinitiator. The insulating adhesive layer composition includes an epoxy resin and a curing agent.

[0006] Further, the protective adhesive layer composition comprises 50-70 parts of UV-curable release resin, 5-10 parts of monomer and 3-7 parts of photoinitiator by weight; and / or the insulating adhesive layer composition comprises 40-70 parts of epoxy resin and 5-10 parts of curing agent by weight; preferably, the UV-curable release resin is selected from any one or more of fluorine-modified acrylate UV-curable release resin, silicone UV-curable release resin and silicone-modified acrylate UV-curable release resin; further preferably, the number average molecular weight of the fluorine-modified acrylate UV-curable release resin is 1000-4000 g / mol; and / or the mass fraction of fluorine in the fluorine-modified acrylate UV-curable release resin is 10-20%; and / or the number average molecular weight of the silicone UV-curable release resin is 2000-5000 g / mol; and / or the number average molecular weight of the silicone-modified acrylate UV-curable release resin is 1000-5000 g / mol.

[0007] Further, the general structure of the polymerized monomer of the above-mentioned fluorine-modified acrylate UV-curable release resin is R f OOC-C(R1)=CH2, wherein R1 is selected from H or -CH3; R f is a fluorine-substituted C1-C 20 alkyl; preferably, R f is selected from any one of C2F5CH2-, H(CF2)8CH2- and H(CF2)6CH2-; and / or the silicone UV-curable release resin is a resin with trimethylsiloxyethyl methacrylate as the polymerized monomer, acryloxy-terminated, and -CH2-Si(CH3)2-O- as the main chain repeating unit; and / or the mass fraction of siloxane chain segment in the silicone-modified acrylate UV-curable release resin is 10-50%.

[0008] Further, the UV-curable release resin at least contains the silicone-modified acrylate UV-curable release resin; preferably, the UV-curable release resin is a combination of the silicone-modified acrylate UV-curable release resin and the fluorine-modified acrylate UV-curable release resin, preferably the mass ratio of the silicone-modified acrylate UV-curable release resin to the fluorine-modified acrylate UV-curable release resin is 1: (1.2-1.5).

[0009] Further, the number average molecular weight of the above-mentioned epoxy resin is 1000-5000 g / mol; preferably, the epoxy resin is a benzene ring-containing epoxy resin.

[0010] Further, the epoxy resin is selected from any one or more of bisphenol A epoxy resin, phenolic epoxy resin and bisphenol F epoxy resin; preferably, the epoxy resin contains at least phenolic epoxy resin; further preferably, the epoxy resin is a combination of phenolic epoxy resin and bisphenol A epoxy resin, preferably with a mass ratio of phenolic epoxy resin to bisphenol A epoxy resin of 1: (0.5-0.8).

[0011] Further, the monomer is a hydroxyl-containing acrylate monomer; preferably, the hydroxyl-containing acrylate monomer is selected from any one or more of 1,6-hexanediol diacrylate, trimethylolpropane triacrylate and 1,4-butanediol diacrylate; and / or, the photoinitiator is a free radical photoinitiator; preferably, the free radical photoinitiator is selected from any one or more of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, 1-hydroxycyclohexyl phenyl ketone, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide and 2-hydroxy-2-methylpropiophenone; and / or, the curing agent is selected from an amine curing agent and / or a hydrazide curing agent; preferably, the amine curing agent is selected from any one or more of dicyandiamide, ethylenediamine and tetraethylenepentamine; and / or, the hydrazide curing agent is selected from any one or more of benzenesulfonyl hydrazide, adipic acid dihydrazide and succinic acid hydrazide.

[0012] Further, the protective adhesive layer composition further comprises 5-10 parts of a first filler; preferably, the first filler is selected from any one or more of barium sulfate, talc, boron nitride and polytetrafluoroethylene; and / or, the protective adhesive layer composition further comprises 0.1-0.5 parts of a first defoaming agent; and / or, the protective adhesive layer composition further comprises 0.1-0.5 parts of a first leveling agent; and / or, the protective adhesive layer composition further comprises 1-3 parts of a first thixotropic agent; and / or, the insulating adhesive layer composition further comprises 25-35 parts of a second filler; preferably, the second filler is selected from any one or more of talc, barium sulfate and bentonite; and / or, the insulating adhesive layer composition further comprises 0.1-0.5 parts of a second defoaming agent; and / or, the insulating adhesive layer composition further comprises 0.1-0.5 parts of a second leveling agent; and / or, the insulating adhesive layer composition further comprises 3-10 parts of a second thixotropic agent; and / or, the insulating adhesive layer composition further comprises 3-9 parts of a curing accelerator.

[0013] According to another aspect of the present application, there is provided a battery piece with a protective adhesive layer and an insulating adhesive layer, the insulating adhesive layer being prepared from the insulating adhesive layer composition of the aforementioned adhesive layer composition, and the protective adhesive layer being prepared from the protective adhesive layer composition of the aforementioned adhesive layer composition; preferably, the thickness of the protective adhesive layer is 8-15 μm; and / or, the thickness of the insulating adhesive layer is 25-45 μm; and / or, the protective adhesive layer is located on the front side of the battery piece, and the insulating adhesive layer is located on the back side of the battery piece.

[0014] According to another aspect of the present application, a photovoltaic module is provided, which comprises the aforementioned cell with protective and insulating adhesive layers.

[0015] By using the technical solution of the present application, the UV-curable release resin in the present application remains stable at high temperature of 260-280℃ and is not prone to softening. It has good anti-sticking effect and is not prone to sticking with other resins. Even if the cells are in close contact, they can be easily separated after cooling, reducing the production difficulty and cost increase caused by sticking. The epoxy resin in the insulating adhesive layer composition has good insulating effect and high stability at high temperature. The UV-curable release resin in the protective adhesive layer composition is used in combination with the epoxy resin in the insulating adhesive layer composition, which helps to further reduce the adhesion of the protective adhesive layer and the insulating adhesive layer after being pressed and heated. DETAILED DESCRIPTION

[0016] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments.

[0017] As analyzed in the background art of the present application, the protective and insulating adhesive layers on the stacked cells in the prior art are prone to sticking after being pressed and heated. In order to solve this problem, the present application provides a set of adhesive layer compositions, cells with protective and insulating adhesive layers, and photovoltaic modules.

[0018] In a typical embodiment of the present application, a set of adhesive layer compositions is provided, which comprises a protective adhesive layer composition and an insulating adhesive layer composition. The protective adhesive layer composition comprises a UV-curable release resin, a monomer, and a photoinitiator. The insulating adhesive layer composition comprises an epoxy resin and a curing agent.

[0019] The UV-curable release resin in the present application remains stable at high temperature of 260-280℃ and is not prone to softening. It has good anti-sticking effect and is not prone to sticking with other resins. Even if the cells are in close contact, they can be easily separated after cooling, reducing the production difficulty and cost increase caused by sticking. The epoxy resin in the insulating adhesive layer composition has good insulating effect and high stability at high temperature. The UV-curable release resin in the protective adhesive layer composition is used in combination with the epoxy resin in the insulating adhesive layer composition, which helps to further reduce the adhesion of the protective adhesive layer and the insulating adhesive layer after being pressed and heated.

[0020] In order to improve the mutual cooperation among the components, thereby further improving the stability of the protective adhesive layer and the insulating adhesive layer, and further improving the service life and light conversion efficiency of the photovoltaic module, in an embodiment of the present application, the protective adhesive layer composition comprises 50-70 parts of UV-curable release resin, 5-10 parts of monomer and 3-7 parts of photoinitiator; and / or, the insulating adhesive layer composition comprises 40-70 parts of epoxy resin and 5-10 parts of curing agent.

[0021] In an embodiment of the present application, the UV-curable release resin is selected from any one or more of fluorine-modified acrylate UV-curable release resin, silicone UV-curable release resin and silicone-modified acrylate UV-curable release resin; preferably, the number average molecular weight of the fluorine-modified acrylate UV-curable release resin is 1000-4000 g / mol; and / or, the mass fraction of fluorine in the fluorine-modified acrylate UV-curable release resin is 10-20%; and / or, the number average molecular weight of the silicone UV-curable release resin is 2000-5000 g / mol; and / or, the number average molecular weight of the silicone-modified acrylate UV-curable release resin is 1000-5000 g / mol.

[0022] Controlling the type of UV-curable release resin within the above range helps to further improve the synergistic effect between it and the epoxy resin, thereby helping to further reduce the adhesion of the protective adhesive layer and the insulating adhesive layer after being subjected to pressure and high temperature, and helping to improve the light curing efficiency. Controlling the number average molecular weight of the fluorine-modified acrylate UV-curable release resin within the above range helps to make the fluorine-modified acrylate UV-curable release resin have better flowability, heat resistance and anti-sticking effect. Controlling the mass fraction of fluorine in the fluorine-modified acrylate UV-curable release resin within the above range helps to further improve the anti-sticking effect of the fluorine-modified acrylate UV-curable release resin while maintaining its stability. Controlling the number average molecular weight of the silicone UV-curable release resin within the above range helps to further improve the curing speed and high temperature stability of the silicone UV-curable release resin.

[0023] In order to further improve the high temperature stability and anti-sticking performance of the UV-curable release resin, and the synergistic effect with the epoxy resin, thereby further reducing the adhesion of the protective adhesive layer and the insulating adhesive layer after being subjected to pressure and high temperature, in an embodiment of the present application, the structure general formula of the polymerized monomer of the fluorine-modified acrylate UV-curable release resin is R f OOC-C(R1)=CH2, wherein R1 is selected from H or -CH3; R f is a fluorine-substituted C1-C 20 alkyl group; preferably, Rf Any one selected from C2F5CH2-, H(CF2)8CH2- and H(CF2)6CH2-; and / or the silicone UV-curable release resin is a resin with trimethylsiloxylethyl methacrylate as the polymerization monomer, acryloyloxy as the end cap, and -CH2-Si(CH3)2-O- as the main chain repeating unit; and / or the mass fraction of the siloxane segment in the silicone-modified acrylic UV-curable release resin is 10-50%.

[0024] including but not limited to, the model of the above-mentioned silicone-modified acrylic UV-curable release resin is selected from Jieda 5100, Baoxing B-828 or Baorun Chemical 5706; wherein Jieda 5100 is a silicone segment on a side group, the main chain is an acrylic component, the mass fraction of the silicone segment is 10%, Baoxing B-828 is a silicone segment on a side group, the mass fraction of the silicone segment is 15%, and Baorun Chemical 5706 has a silicone segment on the main chain, and the mass fraction of the silicone segment is 50%.

[0025] In an embodiment of the present application, the above-mentioned UV-curable release resin contains at least a silicone-modified acrylic UV-curable release resin; preferably, the UV-curable release resin is a combination of a silicone-modified acrylic UV-curable release resin and a fluorine-modified acrylic ester UV-curable release resin, and preferably the mass ratio of the silicone-modified acrylic UV-curable release resin to the fluorine-modified acrylic ester UV-curable release resin is 1: (1.2-1.5).

[0026] The presence of Si-O bonds in the silicone-modified acrylic UV-curable release resin helps to improve the stability and anti-sticking effect of the protective adhesive layer, and reduces the risk of adhesion between the protective adhesive layer and the insulating adhesive layer after being subjected to pressure and high temperature. The presence of the acrylic ester group helps to improve the transparency of the protective adhesive layer, thereby helping to improve the light conversion efficiency of the photovoltaic module. The structure of the silicone-modified acrylic UV-curable release resin enables it to have excellent chemical stability in extreme environments, and when applied to a photovoltaic module, it helps to improve the service life of the photovoltaic module. The silicone-modified acrylic UV-curable release resin and the fluorine-modified acrylic UV-curable release resin can be copolymerized into one component under the action of a photoinitiator, and are connected to each other by carbon-carbon bonds, so as to further improve the high-temperature stability and release force of the protective adhesive layer, and have more excellent high-temperature resistance.

[0027] In an embodiment of the present application, the number average molecular weight of the above-mentioned epoxy resin is 1000-5000 g / mol; preferably, the epoxy resin is a benzene ring-containing epoxy resin.

[0028] Controlling the number-average molecular weight of the epoxy resin within the aforementioned range helps to achieve suitable hardness in the insulating layer, while also balancing the epoxy resin's flowability and chemical stability. Epoxy resins containing benzene rings exhibit higher heat resistance, thereby further reducing the risk of adhesion between the protective and insulating layers after pressure and high temperatures.

[0029] In one embodiment of this application, the epoxy resin is selected from any one or more of bisphenol A epoxy resin, phenolic epoxy resin and bisphenol F epoxy resin; preferably, the epoxy resin contains at least phenolic epoxy resin; more preferably, the epoxy resin is a combination of phenolic epoxy resin and bisphenol A epoxy resin, and preferably the mass ratio of phenolic epoxy resin to bisphenol A epoxy resin is 1:(0.5~0.8).

[0030] Controlling the type of epoxy resin within the aforementioned range helps improve its heat resistance and enhances its synergistic effect with UV-curable release resins, thereby further reducing the adhesion between the protective and insulating layers under pressure and high temperatures. Phenolic epoxy resins, due to the presence of multiple benzene rings in their structure, exhibit extremely high thermal stability, remaining stable even at 280°C. The phenolic structure endows the resin with excellent electrical insulation properties, maintaining stable insulation performance even under high temperature and pressure conditions. Bisphenol A has a much lower viscosity than phenolic resins and higher reactivity. Bisphenol A also contains multiple benzene rings, forming a cross-linked network structure with the phenolic resin during curing, which is beneficial for improving thermal stability.

[0031] To further improve the structural stability of the adhesive layer, in one embodiment of this application, the monomer is a hydroxyl-containing acrylate monomer; preferably, the hydroxyl-containing acrylate monomer is selected from any one or more of 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, and 1,4-butanediol diacrylate; and / or, the photoinitiator is a free radical photocuring initiator; preferably, the free radical photocuring initiator is selected from any one or more of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, 1-hydroxycyclohexylphenyl ketone, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, and 2-hydroxy-2-methylphenylacetone; and / or, the curing agent is selected from amine curing agents and / or acyl hydrazide curing agents; preferably, the amine curing agent is selected from any one or more of dicyandiamide, ethylenediamine, and tetraethylenepentamine; and / or, the acyl hydrazide curing agent is selected from any one or more of benzenesulfonyl hydrazide, adipic acid dihydrazide, and succinic acid hydrazide.

[0032] In one embodiment of this application, the protective adhesive layer composition further includes 5-10 parts of a first filler; preferably, the first filler is selected from any one or more of barium sulfate, talc, boron nitride, and polytetrafluoroethylene; and / or, the protective adhesive layer composition further includes 0.1-0.5 parts of a first defoamer; and / or, the protective adhesive layer composition further includes 0.1-0.5 parts of a first leveling agent; and / or, the protective adhesive layer composition further includes 1-3 parts of a first thixotropic agent; and / or, the insulating adhesive layer composition further includes 25-35 parts of a second filler; preferably, the second filler is selected from any one or more of talc, barium sulfate, and bentonite; and / or, the insulating adhesive layer composition further includes 0.1-0.5 parts of a second defoamer; and / or, the insulating adhesive layer composition further includes 0.1-0.5 parts of a second leveling agent; and / or, the insulating adhesive layer composition further includes 3-10 parts of a second thixotropic agent; and / or, the insulating adhesive layer composition further includes 3-9 parts of a curing accelerator.

[0033] The addition of the first filler helps to further improve the thermal stability of the UV-curable release resin, enabling it to maintain structural integrity under high-temperature conditions and reducing softening and deformation. Controlling the type of the first filler within the aforementioned range helps to enhance the synergistic effect between the first filler and the UV-curable release resin, thereby further improving the heat resistance of the protective adhesive layer. The first defoamer helps to eliminate air bubbles generated during the mixing process of the protective adhesive layer composition, while the first leveling agent improves the smoothness of the protective adhesive layer before curing, reducing pinholes and unevenness, and enhancing the appearance quality and optical properties of the protective adhesive layer. The first thixotropic agent adjusts the viscosity and thixotropy of the UV-curable release resin, ensuring uniform flow during screen printing. The addition of the second filler helps to improve the hardness and abrasion resistance of the insulating adhesive layer, and also improves its heat resistance. Controlling the type of the second filler within the aforementioned range helps to enhance the synergistic effect between the second filler and the epoxy resin, thereby further improving the heat resistance of the insulating adhesive layer. The use of the second defoamer and the second leveling agent helps to eliminate air bubbles and improve the leveling properties of the insulating adhesive layer. The second thixotropic agent can improve the processing performance of the insulating adhesive, while the curing accelerator can accelerate the curing process and improve curing efficiency.

[0034] Including but not limited to, the first defoamer is selected from any one or more of defoamer KS66, defoamer X623 and defoamer X635; the first leveling agent is selected from any one or more of leveling agent BYK358N, leveling agent WZ341 and leveling agent L378; the first thixotropic agent is selected from any one or more of fumed silica A200, fumed silica A300 and fumed silica R972; the second defoamer is selected from any one or more of defoamer X680, defoamer BYK-A500 and defoamer BYK-724; the second leveling agent is selected from any one or more of leveling agent L3580, leveling agent BYK-3540 and leveling agent BYK-3499; the second thixotropic agent is selected from any one or more of fumed silica R974, fumed silica TS530 and fumed silica TS-610; and the curing accelerator is selected from any one or more of imidazole, triethylamine and triethanolamine.

[0035] In another typical embodiment of this application, a battery cell with a protective adhesive layer and an insulating adhesive layer is provided. The insulating adhesive layer is prepared from the insulating adhesive layer combination in the aforementioned adhesive layer composition, and the protective adhesive layer is prepared from the protective adhesive layer composition in the aforementioned adhesive layer composition. Preferably, the thickness of the protective adhesive layer is 8~15μm; and / or, the thickness of the insulating adhesive layer is 25~45μm; and / or, the protective adhesive layer is located on the front side of the battery cell, and the insulating adhesive layer is located on the back side of the battery cell.

[0036] Because the aforementioned battery cell contains the protective adhesive layer and insulating adhesive layer of this application, the battery cell is easy to separate after passivation.

[0037] In one embodiment of this application, two battery cells with a protective adhesive layer on the front and an insulating adhesive layer on the back are stacked together with their front and back sides facing each other, and 7 kg of glass is placed on top. The cells are then placed in a 280°C oven for 3 hours. After cooling, the adhesion between the two battery cells is 1~13 N / cm.

[0038] In another typical embodiment of this application, a photovoltaic module is provided, which includes the aforementioned solar cells with protective and insulating adhesive layers.

[0039] Since the photovoltaic modules mentioned above include the solar cells with protective and insulating adhesive layers of this application, it helps to improve the production efficiency of photovoltaic modules.

[0040] In one embodiment of this application, the above-mentioned protective adhesive composition is sequentially mixed, ground, screen-printed on one side of the battery cell, and cured with ultraviolet light to form a protective adhesive layer on one side of the battery cell.

[0041] In one embodiment of this application, the above-mentioned insulating adhesive composition is sequentially mixed, ground, screen-printed on the other side of the battery cell, and thermally cured to form an insulating adhesive layer on the other side of the battery cell.

[0042] The beneficial effects of this application will be further illustrated below with reference to the embodiments.

[0043] Example 1

[0044] By weight, the protective adhesive layer composition comprises 60 parts of silicone-modified acrylic UV-curable release resin (model: Jieshida 5100, with a siloxane segment content of 10% and a number average molecular weight of 2500 g / mol), 7 parts of 1,6-hexanediol diacrylate, 5 parts of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, 7 parts of barium sulfate, 0.3 parts of defoamer KS66, 0.3 parts of leveling agent BYK358N, and 2 parts of fumed silica A200.

[0045] The protective adhesive layer was prepared using the above-mentioned composition. Specifically, (2,4,6-trimethylbenzoyl)diphenylphosphine oxide was first dissolved in 1,6-hexanediol diacrylate, and then silicone-modified acrylic UV-curable release resin, barium sulfate, defoamer KS66, leveling agent BYK358N, and fumed silica A200 were added and stirred evenly. The mixture was then ground to a fineness of less than 8 μm and screen-printed onto the front side of the BC solar cell. The mixture was then cured under an LED UV lamp to form a protective adhesive layer with a thickness of 12 μm on the front side of the BC solar cell.

[0046] By weight, the insulating adhesive layer composition comprises 60 parts of phenolic epoxy resin (model: Sanmu Chemical 6136, number average molecular weight: 1300 g / mol), 7 parts of dicyandiamide, 30 parts of talc, 0.3 parts of defoamer X680, 0.3 parts of leveling agent L3580, 7 parts of fumed silica A200 and 6 parts of imidazole;

[0047] The insulating adhesive layer is prepared using the above-mentioned insulating adhesive layer composition. Specifically, the above-mentioned insulating adhesive layer composition is added together, stirred evenly and ground to a fineness of less than 8μm, screen-printed onto the reverse side of the BC battery cell by screen printing, and then baked in an oven at a high temperature of 150°C for 10 minutes to cure completely, so as to form an insulating adhesive layer with a thickness of 35μm on the reverse side of the BC battery cell.

[0048] Example 2

[0049] The protective adhesive layer composition comprises 70 parts of silicone-modified acrylic UV-curable release resin (model: Boxin B-828, number average molecular weight: 1800 g / mol, mass percentage of siloxane segments: 15%), 5 parts of trimethylolpropane triacrylate, 3 parts of 1-hydroxycyclohexylphenyl ketone, 10 parts of talc, 0.5 parts of defoamer KS66, 0.5 parts of leveling agent BYK358N, and 3 parts of fumed silica A200.

[0050] The protective adhesive layer is prepared using the above-mentioned protective adhesive layer composition. Specifically, 1-hydroxycyclohexylphenyl ketone is first dissolved in trimethylolpropane triacrylate, and then silicone-modified acrylic UV-curable release resin, talc, defoamer KS66, leveling agent BYK358N and fumed silica A200 are added and stirred evenly. The mixture is then ground to a fineness of less than 8μm and screen-printed onto the front side of the BC solar cell. The mixture is then cured under an LED UV lamp to form a protective adhesive layer with a thickness of 12μm on the front side of the BC solar cell.

[0051] The insulating adhesive layer composition includes 70 parts of phenolic epoxy resin (number average molecular weight of 3000 g / mol, model SQCN703), 5 parts of dicyandiamide, 35 parts of barium sulfate, 0.5 parts of defoamer X680, 0.5 parts of leveling agent L3580, 10 parts of fumed silica A200 and 9 parts of triethylamine, ultimately yielding a BC battery cell with a protective adhesive layer on the front and an insulating adhesive layer on the back.

[0052] The insulating adhesive layer is prepared using the above-mentioned insulating adhesive layer composition. Specifically, the above-mentioned insulating adhesive layer composition is added together, stirred evenly and ground to a fineness of less than 8μm, screen-printed onto the reverse side of the BC battery cell by screen printing, and then baked in an oven at a high temperature of 150°C for 10 minutes to cure completely, so as to form an insulating adhesive layer with a thickness of 35μm on the reverse side of the BC battery cell.

[0053] Example 3

[0054] The protective adhesive layer composition comprises 50 parts of silicone-modified acrylic UV-curable release resin (model: Baojun Chemical 5706, number average molecular weight: 2000 g / mol, mass percentage of siloxane segments: 50%), 10 parts of 1,4-butanediol diacrylate, 7 parts of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, 5 parts of boron nitride, 0.1 parts of defoamer KS66, 0.1 parts of leveling agent BYK358N, and 1 part of fumed silica A200.

[0055] The protective adhesive layer was prepared using the above-mentioned protective adhesive layer composition. Specifically, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide was first dissolved in 1,4-butanediol diacrylate, and then silicone-modified acrylic UV-curable release resin, boron nitride, defoamer KS66, leveling agent BYK358N and fumed silica A200 were added and stirred evenly. The mixture was then ground to a fineness of less than 8 μm and screen-printed onto the front side of the BC solar cell. The mixture was then cured under an LED UV lamp to form a protective adhesive layer with a thickness of 12 μm on the front side of the BC solar cell.

[0056] The insulating adhesive layer composition includes 40 parts of phenolic epoxy resin (number average molecular weight of 1300 g / mol, model SQCN703), 10 parts of benzenesulfonyl hydrazine, 25 parts of talc, 0.1 parts of defoamer X680, 0.1 parts of leveling agent L3580, 3 parts of fumed silica A300 and 3 parts of imidazole, finally obtaining a BC battery cell with a protective adhesive layer on the front and an insulating adhesive layer on the back.

[0057] The insulating adhesive layer is prepared using the above-mentioned insulating adhesive layer composition. Specifically, the above-mentioned insulating adhesive layer composition is added together, stirred evenly and ground to a fineness of less than 8μm, screen-printed onto the reverse side of the BC battery cell by screen printing, and then baked in an oven at a high temperature of 150°C for 10 minutes to cure completely, so as to form an insulating adhesive layer with a thickness of 35μm on the reverse side of the BC battery cell.

[0058] Example 4

[0059] The difference from Example 1 is that the number average molecular weight of the silicone-modified acrylic UV-curable release resin is 1000 g / mol, resulting in a BC battery cell with a protective adhesive layer on the front and an insulating adhesive layer on the back.

[0060] Example 5

[0061] The difference from Example 1 is that the number average molecular weight of the silicone-modified acrylic UV-curable release resin is 5000 g / mol, resulting in a BC battery cell with a protective adhesive layer on the front and an insulating adhesive layer on the back.

[0062] Example 6

[0063] The difference from Example 1 is that the number average molecular weight of the silicone-modified acrylic UV-curable release resin is 6000 g / mol, resulting in a BC battery cell with a protective adhesive layer on the front and an insulating adhesive layer on the back.

[0064] Example 7

[0065] The difference from Example 1 is that the mass percentage of siloxane segments in the silicone-modified acrylic UV-curable release resin is 25%, resulting in a BC battery cell with a protective adhesive layer on the front and an insulating adhesive layer on the back.

[0066] Example 8

[0067] The difference from Example 1 is that the mass ratio of siloxane segments in the silicone-modified acrylic UV-curable release resin is 50%, resulting in a BC battery cell with a protective adhesive layer on the front and an insulating adhesive layer on the back.

[0068] Example 9

[0069] The difference from Example 1 is that the mass percentage of siloxane segments in the silicone-modified acrylic UV-curable release resin is 5%, resulting in a BC battery cell with a protective adhesive layer on the front and an insulating adhesive layer on the back.

[0070] Example 10

[0071] The difference from Example 1 is that a fluorinated acrylate UV-curable release resin (model: Jieshida DSP-847F) was used instead of a silicone-modified acrylate UV-curable release resin. The number-average molecular weight of the fluorinated acrylate UV-curable release resin was 2800 g / mol, the mass percentage of fluorine in the fluorinated acrylate UV-curable release resin was 10%, and the chemical formula of the monomer of the fluorinated acrylate UV-curable release resin was R. f OOC-C(R1)=CH2, where R1 is -CH3; R f The final product is a BC solar cell with a protective adhesive layer on the front and an insulating adhesive layer on the back, which is H(CF2)6CH2-.

[0072] Example 11

[0073] The difference from Example 1 is that a fluorinated acrylate UV-curable release resin (model: Jieshida PU-582) is used instead of a silicone-modified acrylate UV-curable release resin. The number-average molecular weight of the fluorinated acrylate UV-curable release resin is 2800 g / mol, the mass percentage of fluorine in the fluorinated acrylate UV-curable release resin is 20%, and the chemical formula of the monomer of the fluorinated acrylate UV-curable release resin is R. f OOC-C(R1)=CH2, where R1 is -CH3; R f The final product is a BC solar cell with a protective adhesive layer on the front and an insulating adhesive layer on the back, which is H(CF2)6CH2-.

[0074] Example 12

[0075] The difference from Example 1 is that an organosilicon UV-curable release resin (model Zhanxin 350) is used instead of the organosilicon-modified acrylic UV-curable release resin. The number average molecular weight of the organosilicon UV-curable release resin is 3500 g / mol. The organosilicon UV-curable release resin is a resin with trimethylsiloxane ethyl methacrylate as the polymer monomer, acryloyloxy end capping, and -CH2-Si(CH3)2-O- as the main chain repeating unit, and finally obtains a BC battery cell with a protective adhesive layer on the front and an insulating adhesive layer on the back.

[0076] Example 13

[0077] The difference from Example 1 is that a combination of silicone-modified acrylic UV-curable release resin and fluorinated acrylate UV-curable release resin (model: Jieshida DSP-847F) is used to replace the silicone-modified acrylic UV-curable release resin. The mass ratio of the silicone-modified acrylic UV-curable release resin to the fluorinated acrylate UV-curable release resin in the combination is 1:1.5, resulting in a BC battery cell with a protective adhesive layer on the front and an insulating adhesive layer on the back.

[0078] Example 14

[0079] The difference from Example 1 is that a combination of silicone-modified acrylic UV-curable release resin and fluorinated acrylate UV-curable release resin (model: Jieshida DSP-847F) is used to replace the silicone-modified acrylic UV-curable release resin. The mass ratio of silicone-modified acrylic UV-curable release resin to fluorinated acrylate UV-curable release resin in the combination is 1:1.2, resulting in a BC battery cell with a protective adhesive layer on the front and an insulating adhesive layer on the back.

[0080] Example 15

[0081] The difference from Example 1 is that a combination of phenolic epoxy resin and bisphenol A epoxy resin (model: Sanmu Chemical 828, number average molecular weight: 3000 g / mol) is used to replace the phenolic epoxy resin, and the mass ratio of phenolic epoxy resin to bisphenol A epoxy resin in the combination is 1:0.5, finally obtaining a BC battery cell with a protective adhesive layer on the front and an insulating adhesive layer on the back.

[0082] Example 16

[0083] The difference from Example 1 is that a combination of phenolic epoxy resin and bisphenol A epoxy resin (model: Sanmu Chemical 828, number average molecular weight: 3000 g / mol) is used to replace the phenolic epoxy resin, and the mass ratio of phenolic epoxy resin to bisphenol A epoxy resin in the combination is 1:0.8, finally obtaining a BC battery cell with a protective adhesive layer on the front and an insulating adhesive layer on the back.

[0084] Example 17

[0085] The difference from Example 1 is that the weight parts of barium sulfate, defoamer KS66, BYK358N, and fumed silica A200 in the protective adhesive layer composition are all 0; the weight parts of talc, defoamer X680, leveling agent L3580, fumed silica A200, and imidazole in the insulating adhesive layer composition are all 0, and finally a BC battery cell with a protective adhesive layer on the front and an insulating adhesive layer on the back is obtained.

[0086] Comparative Example 1

[0087] The difference from Example 1 is that polyurethane acrylate (model Yuhe New Material 6283B) is used instead of silicone-modified acrylic UV-curable release resin, resulting in a BC battery cell with a protective adhesive layer on the front and an insulating adhesive layer on the back.

[0088] Comparative Example 2

[0089] The difference from Example 1 is that polyepoxy acrylate (model Sanmu Chemical 6105) is used instead of phenolic epoxy resin, resulting in a BC battery cell with a protective adhesive layer on the front and an insulating adhesive layer on the back.

[0090] Comparative Example 3

[0091] The difference from Example 1 is that polyurethane acrylate (model Haohui New Materials 93330) is used to replace the silicone-modified acrylic UV-curable release resin, and polyepoxy acrylate (model Sanmu Chemical 6105) is used to replace the phenolic epoxy resin, ultimately resulting in a BC battery cell with a protective adhesive layer on the front and an insulating adhesive layer on the back.

[0092] Comparative Example 4

[0093] The difference from Example 1 is that polyimide (model Ningbo Jinshan Electronic Materials 36MT) was used instead of silicone-modified acrylic UV-curable release resin, resulting in a BC battery cell with a protective adhesive layer on the front and an insulating adhesive layer on the back.

[0094] Performance testing

[0095] The protective adhesive layers prepared in the examples and comparative examples were tested. The transmittance in the range of 400nm to 1150nm was measured using a Carry5000 spectrophotometer, and the transmittance in the range of 400nm to 1100nm was measured. The yellowing value was measured using a Ci7x00 colorimeter. The hardness was measured using a pencil hardness tester. The tip of a pencil was brought into contact with the coating, and the hardness tester was immediately pushed away from the operator at a speed of 0.5mm / s to 1mm / s for at least 7mm. The scratches were then observed. The adhesion grade was determined using the cross-cut adhesion test. The adhesive layer was applied to the battery cell, and 100 cross-cuts were scraped out with a cross-cut adhesion tester. The adhesion of the adhesive layer was observed. If the adhesive layer did not peel off, it was grade 0. The test results are shown in Table 1.

[0096] The insulating adhesive layers prepared in the examples and comparative examples were tested. Hardness: A pencil hardness tester was used. The tip of a pencil touched the coating, and the hardness tester was immediately pushed away from the operator at a speed of 0.5 mm / s to 1 mm / s for at least 7 mm. The scratches were observed. Adhesion grade: The adhesion test method was the cross-cut adhesion test. The adhesive layer was applied to the battery cell, and 100 cross-cuts were created with a cross-cut knife. The adhesion of the adhesive layer was observed; if it did not peel off, it was grade 0. Initial adhesion to the adhesive film: A component was constructed for testing. From bottom to top, the layers were glass, adhesive film, battery cell, separator paper, adhesive film, and backsheet. A tensile tester was used after lamination. Volume resistivity: The adhesive film was cut into 6×6 cm shapes and tested using a 6571B high-resistivity meter. The test results are shown in Table 2.

[0097] Two BC solar cells with a protective adhesive layer on the front and an insulating adhesive layer on the back were stacked face to face, with a 7kg glass plate on top. After being placed in a 280℃ oven for 3 hours, the solar cells were removed and cooled, and the adhesion between the two solar cells was tested.

[0098] The BC battery cells with a protective adhesive layer on the front and an insulating adhesive layer on the back prepared in the examples and comparative examples were subjected to the above-mentioned adhesion test. The test results are shown in Table 3.

[0099] Table 1

[0100]

[0101] Table 2

[0102]

[0103] Table 3

[0104]

[0105] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0106] The UV-curable release resin in this application remains stable at high temperatures of 260-280°C, does not easily soften, and has good anti-stick properties, making it less prone to adhesion to other resins. Even if the battery cells are in close contact, they can be easily separated after cooling, reducing the production difficulty and cost increase caused by adhesion. The epoxy resin in the insulating adhesive layer composition has good insulation properties and high stability at high temperatures. The UV-curable release resin in the protective adhesive layer composition, used in combination with the epoxy resin in the insulating adhesive layer composition, helps to further reduce the adhesion between the protective adhesive layer and the insulating adhesive layer after pressure and high temperature.

[0107] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A group of adhesive layer compositions, characterized in that, The adhesive layer composition includes a protective adhesive layer composition and an insulating adhesive layer composition. The protective adhesive layer composition includes a UV-curable release resin, a monomer, and a photoinitiator; The insulating adhesive composition includes epoxy resin and a curing agent.

2. The adhesive composition according to claim 1, characterized in that, By weight, the protective adhesive layer composition comprises 50-70 parts of the UV-curable release resin, 5-10 parts of the monomer, and 3-7 parts of the photoinitiator; And / or, by weight, the insulating adhesive layer composition comprises 40 to 70 parts of the epoxy resin and 5 to 10 parts of the curing agent; Preferably, the UV-curable release resin is selected from any one or more of fluorine-modified acrylate UV-curable release resin, silicone UV-curable release resin, and silicone-modified acrylate UV-curable release resin; More preferably, the number average molecular weight of the fluorinated acrylate UV-curable release resin is 1000~4000 g / mol; and / or, the mass percentage of fluorine in the fluorinated acrylate UV-curable release resin is 10~20%; And / or, the number average molecular weight of the organosilicon UV-curable release resin is 2000~5000 g / mol; And / or, the number average molecular weight of the silicone-modified acrylic UV-curable release resin is 1000~5000 g / mol.

3. The adhesive composition according to claim 2, characterized in that, The general structural formula of the monomer of the fluorine-modified acrylate UV-curable release resin is R. f OOC-C(R1)=CH2, where R1 is selected from H or -CH3; R f C1~C substituted with fluorine 20 alkyl; Preferably, the R f Selected from any one of C2F5CH2-, H(CF2)8CH2- and H(CF2)6CH2-; And / or, the organosilicon UV-curable release resin is a resin with trimethylsiloxane ethyl methacrylate as the polymer monomer, acryloyloxy end capping, and -CH2-Si(CH3)2-O- as the main chain repeating unit. And / or, the mass percentage of siloxane segments in the silicone-modified acrylic UV-curable release resin is 10-50%.

4. The adhesive composition according to claim 2, characterized in that, The UV-curable release resin contains at least the silicone-modified acrylic UV-curable release resin; preferably, the UV-curable release resin is a combination of the silicone-modified acrylic UV-curable release resin and the fluorinated acrylic UV-curable release resin, and preferably the mass ratio of the silicone-modified acrylic UV-curable release resin to the fluorinated acrylic UV-curable release resin is 1:(1.2~1.5).

5. The adhesive composition according to any one of claims 1 to 4, characterized in that, The number-average molecular weight of the epoxy resin is 1000~5000 g / mol; Preferably, the epoxy resin is an epoxy resin containing benzene rings.

6. The adhesive composition according to claim 5, characterized in that, The epoxy resin is selected from any one or more of bisphenol A epoxy resin, phenolic epoxy resin and bisphenol F epoxy resin; Preferably, the epoxy resin contains at least the phenolic epoxy resin; More preferably, the epoxy resin is a combination of the phenolic epoxy resin and the bisphenol A epoxy resin, and preferably the mass ratio of the phenolic epoxy resin to the bisphenol A epoxy resin is 1:(0.5~0.8).

7. The adhesive composition according to any one of claims 1 to 4, characterized in that, The monomer is a hydroxyl-containing acrylate monomer; preferably, the hydroxyl-containing acrylate monomer is selected from any one or more of 1,6-hexanediol diacrylate, trimethylolpropane triacrylate and 1,4-butanediol diacrylate. And / or, the photoinitiator is a free radical photocuring initiator; preferably, the free radical photocuring initiator is selected from any one or more of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, 1-hydroxycyclohexylphenyl ketone, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide and 2-hydroxy-2-methylphenylacetone; And / or, the curing agent is selected from amine curing agents and / or acyl hydrazide curing agents; preferably, the amine curing agent is selected from any one or more of dicyandiamide, ethylenediamine and tetraethylenepentamine; and / or, the acyl hydrazide curing agent is selected from any one or more of benzenesulfonyl hydrazide, adipic acid dihydrazide and succinic acid hydrazide.

8. The adhesive composition according to claim 2, characterized in that, The protective adhesive layer composition further includes 5 to 10 parts of a first filler; preferably, the first filler is selected from any one or more of barium sulfate, talc, boron nitride, and polytetrafluoroethylene; And / or, the protective adhesive layer composition further includes 0.1 to 0.5 parts of a first defoamer; and / or, the protective adhesive layer composition further includes 0.1 to 0.5 parts of a first leveling agent; and / or, the protective adhesive layer composition further includes 1 to 3 parts of a first thixotropic agent; And / or, the insulating adhesive layer composition further includes 25 to 35 parts of a second filler; preferably, the second filler is selected from any one or more of talc, barium sulfate, and bentonite; And / or, the insulating adhesive layer composition further includes 0.1 to 0.5 parts of a second defoamer; and / or, the insulating adhesive layer composition further includes 0.1 to 0.5 parts of a second leveling agent; and / or, the insulating adhesive layer composition further includes 3 to 10 parts of a second thixotropic agent; and / or, the insulating adhesive layer composition further includes 3 to 9 parts of a curing accelerator.

9. A battery cell with a protective adhesive layer and an insulating adhesive layer, characterized in that, The insulating adhesive layer is prepared from the insulating adhesive layer combination in the adhesive layer composition according to any one of claims 1 to 8, and the protective adhesive layer is prepared from the protective adhesive layer composition in the adhesive layer composition according to any one of claims 1 to 8; preferably, the thickness of the protective adhesive layer is 8~15μm; And / or, the thickness of the insulating adhesive layer is 25~45μm; and / or, the protective adhesive layer is located on the front side of the battery cell, and the insulating adhesive layer is located on the back side of the battery cell.

10. A photovoltaic module, characterized in that, The photovoltaic module includes the solar cells with a protective adhesive layer and an insulating adhesive layer as described in claim 9.

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