Single-component thermocuring insulation paste for photovoltaic BC battery and preparation method of single-component thermocuring insulation paste

Abstract

The invention relates to the technical field of solar cells, and particularly discloses a single-component thermocuring insulation paste for a photovoltaic BC cell and a preparation method of the single-component thermocuring insulation paste. Comprising the following components: 70-95 wt% of polyfunctional acrylate resin, 1-3 wt% of an adsorption filler, 1-3 wt% of an acid absorption filler, 1-4 wt% of a reaction acid filler, 0.5-2 wt% of a leveling defoaming aid, 0.1-1 wt% of an initiator, 0-2 wt% of a photoprotective agent and 0-10 wt% of a pigment. According to the insulating glue for the photovoltaic BC battery, the pigment, the adsorption filler, the acid absorption filler, the reaction acid filler and the photoprotective agent are used as fillers in the insulating glue, a film formed by curing is a micro-nano coating, and compared with the currently used common insulating glue, the insulating glue has the functions of efficiently adsorbing and fixing acetic acid generated in a reaction glue film; the effect of preventing the positive and negative electrodes in the BC battery from being contacted is achieved, the function of adsorbing and reacting acetic acid is achieved, and the service life of the assembly is further prolonged.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of solar cells, and particularly discloses a single-component heat-curable insulating glue for a photovoltaic BC cell and a preparation method thereof. BACKGROUND

[0002] In current photovoltaic modules, the BC cell needs to be isolated by insulating glue to avoid short circuit due to structural characteristics, and the insulating glue is crucial in the BC cell module.

[0003] Nowadays, various manufacturers inevitably use EVA glue film in the packaging process to reduce the cost of modules. It is well known that EVA glue film inevitably produces acetic acid in the long-term use process, which causes corrosion of the solder strip, further shortens the service life of the photovoltaic module, although some manufacturers select acid-resistant glue film, the corrosion of the solder strip by acetic acid is still inevitable. The solder strip of the BC cell is more prone to electrochemical corrosion caused by local acetic acid aggregation due to the small distance between the positive and negative electrodes and the thin insulating layer, and finally leads to the formation of ion migration channels between the positive and negative electrodes, and the failure rate of the module is significantly higher than that of the conventional structure. The traditional insulating glue is mainly single epoxy resin or silicone, which has insulation but lacks active acid absorption mechanism and cannot cope with the dynamic acid corrosion environment generated by the long-term aging of the glue film, resulting in a 10%-15% reduction in the service life of the module.

[0004] Some single-component heat-curable adhesives known at present cannot be directly applied to the BC cell, such as a single-component heat-curable acrylate adhesive precursor and a preparation method thereof proposed in patent 201880046490.5, the curing temperature is 120 DEG C and the time is 30 minutes, which seriously restricts the production efficiency of the existing module. In addition, if the single-component heat-curable acrylate adhesive precursor and the preparation method thereof are applied to the insulating glue of the BC cell in the photovoltaic module, the methyl methacrylate acid (the pKa of methyl methacrylate acid is 4.44, between acetic acid (4.76) and acrylic acid (4.26), and belongs to a medium-strength organic acid) in the adhesive is stronger than the acid and will seriously corrode the solder strip.

[0005] Therefore, the application aims to develop an insulating glue with high weather resistance and high efficiency in absorbing acetic acid and applied to the BC cell, which can efficiently absorb acetic acid near the positive and negative electrodes to avoid corrosion of the solder strip and improve the service life of the BC cell module. SUMMARY

[0006] The application aims to overcome the shortcomings of the prior art and provide a single-component heat-curable insulating glue for a photovoltaic BC cell and a preparation method thereof.

[0007] In one aspect, the application discloses a single-component heat-curable insulating glue for a photovoltaic BC cell, which adopts the following technical scheme: A single-component heat-curable insulating glue for a photovoltaic BC cell, which comprises the following components in percentage by mass: 70-95wt% of multifunctional acrylate resin Adsorption filler 1~3wt% Acid-absorbing filler 1~3wt% Reactive acid filler 1~4wt% Leveling and defoaming additive 0.5~2wt% Initiator 0.1~1wt% Light protection agent 0~2wt% Pigment 0~10wt%.

[0008] Preferably, the adsorption filler is one or more of zeolite molecular sieve, kaolin molecular sieve, zirconium powder, nano-silica, and graphene carbon molecular sieve. Preferably, the acid-absorbing filler is a metal-organic framework material.

[0009] Preferably, the reactive acid filler is one or more of magnesium hydroxide, calcium hydroxide, magnesium oxide, zinc oxide, calcium oxide, and metal-organic framework materials.

[0010] Preferably, the mass ratio of the adsorption filler, the acid absorption filler and the reaction acid filler is (1-2): (1-2): 3.

[0011] Preferably, the functionality of the multifunctional acrylate resin is 2 to 6; the multifunctional acrylate resin is one or more of 1,9-nonanediol diacrylate, neopentyl glycol diacrylate, tricyclodecane methanol diacrylate, trimethylolpropane triacrylate, epoxidized trimethylolpropane triacrylate, pentaerythritol acrylate, dipentaerythritol polyacrylate, and epoxidized dipentaerythritol polyacrylate.

[0012] Preferably, the leveling and defoaming aid includes one or both of a leveling agent and a defoaming agent; the leveling agent accounts for 0.25~1wt% of the total weight of the insulating glue, and the defoaming agent accounts for 0.25~1.5wt% of the total weight of the insulating glue; the leveling agent is one or both of an organosilicon-modified polyether leveling agent and an organosilicon leveling agent; the defoaming agent is one or both of a polyether defoaming agent and an organosilicon defoaming agent.

[0013] Preferably, the initiator is one or more of benzoyl peroxide (BPO), dicumyl peroxide (DCP), tert-butyl perbenzoate (TBPB), and tert-butyl peroxycarbonate-2-ethylhexyl ester (TBEC).

[0014] Preferably, the light protection agent includes one or both of an ultraviolet light absorber or a light stabilizer; the ultraviolet light absorber accounts for 0-0.75 wt% of the total weight of the insulating glue, and the light stabilizer accounts for 0-1.35 wt% of the total weight of the insulating glue; the ultraviolet light absorber is one or more of benzophenone, benzotriazole, triazine, zinc oxide, and nano titanium dioxide; and the light stabilizer is a hindered amine light stabilizer.

[0015] Preferably, the pigment is one or more of titanium dioxide, barium sulfate, cadmium red, iron red, 3132 big red powder, carbon black, copper-chromium black, iron-chromium black, cobalt-chromium blue, phthalocyanine blue, stone green, and phthalocyanine green.

[0016] In another aspect, the present application discloses a preparation method of a single-component thermally cured insulating glue for a photovoltaic BC cell, which adopts the following technical scheme: A preparation method of a single-component thermally cured insulating glue for a photovoltaic BC cell, comprising the following steps: S1, taking 0-10 parts of pigment, 1-3 parts of adsorbing filler, 1-3 parts of acid-absorbing filler, 1-3 parts of reaction acid filler, 0-2 parts of light protection agent, 30-50 parts of multifunctional acrylate resin, and 1-2 parts of dispersing agent, putting them into a ball mill to mix and grind uniformly to a fineness of 5-15 μm, and preparing a color paste; S2, taking the color paste in step S1, 0.1-1 parts of initiator, 25-65 parts of multifunctional acrylate resin, and 0.5-2 parts of leveling and defoaming auxiliary agent, mixing uniformly to prepare an insulating glue; S3, taking the insulating glue in step S2, selecting a mesh screen plate with different mesh numbers according to the size of the cell sheet, printing on the surface of the cell sheet, and placing it in a curing oven at 150-180 ℃ for 2-5 min, so as to be cured to a film thickness of 10-100 μm.

[0017] Compared with the prior art, the present application has at least the following beneficial effects: The insulating glue for a photovoltaic BC cell uses pigment, adsorbing filler, acid-absorbing filler, reaction acid filler, and light protection agent as fillers in the insulating glue, and the cured film is a micro-nano coating. Compared with the commonly used insulating glue, the insulating glue has the functions of high-efficiency adsorption, fixation, and reaction of acetic acid generated in the glue film. The main function of the light protection agent is to absorb ultraviolet rays to protect the structure of the insulating glue and improve the weather resistance of the insulating glue. The main function of the adsorbing filler is to adsorb acetic acid near the welding strip at the positive and negative contact position. The main function of the acid-absorbing filler is to fix acetic acid molecules near the welding strip through coordination reaction. The main function of the reaction acid filler is to react with acetic acid molecules to reduce the content of acetic acid near the welding strip to protect the welding strip. The obtained insulating glue not only plays a role in preventing the contact between the positive and negative electrodes in the BC cell, but also has the function of adsorbing and reacting acetic acid, further improving the service life of the module. DETAILED DESCRIPTION

[0018] In order to make the above objectives, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with specific embodiments.

[0019] Example 1 A single-component heat-curable insulating adhesive for a photovoltaic BC cell is prepared by the following method: S1, color paste preparation: take 5 parts of pigment titanium white, 2 parts of adsorbing filler ZSM-5 molecular sieve, 1 part of acid-absorbing filler metal-organic framework material (MOF-801), 3 parts of reactive acid filler magnesium hydroxide, 0.4 parts of ultraviolet light absorber nano titanium dioxide, 0.6 parts of light stabilizer (Tinuvin 770), 10 parts of 2-functional acrylic resin (A-DCP Shin-Nakamura Chemical Co., Ltd.), 20 parts of 4-functional acrylate resin (A-TMMT Shin-Nakamura Chemical Co., Ltd.), 10 parts of 6-functional acrylate resin (A-DPH-12E Shin-Nakamura Chemical Co., Ltd.), 1 part of BYK-W9010 dispersant, use a ball mill for grinding operation, grind for 6 times, use a doctor blade fineness agent to test the grinding fineness of 8 μm, and place the color paste at room temperature for use; S2, insulating adhesive preparation, take the color paste in step 1, 0.5 parts of benzoyl peroxide (BPO) initiator, 20 parts of 4-functional acrylate resin (A-TMMT Shin-Nakamura Chemical Co., Ltd.), 25 parts of 6-functional acrylate resin (A-DPH-12E Shin-Nakamura Chemical Co., Ltd.), 0.75 parts of silicone-modified polyether BYK330 leveling agent, 0.75 parts of polyether BD3-3016 defoaming agent, high-speed dispersion by a disperser, and place the uniformly dispersed insulating adhesive at room temperature for use; S3, take the insulating adhesive in step 2, select different mesh screens according to the size of the cell sheet, print on the surface of the cell sheet, and place it at 160°C for 5 min for curing; S4, use ordinary EVA adhesive film to prepare the cell sheet in step 3 into a photovoltaic module marked as module 1, and at the same time use the commonly used insulating adhesive (without adding adsorbing filler, acid-absorbing filler, and reactive acid filler) on the market to process according to the method in step 3, and use ordinary EVA adhesive film to prepare a photovoltaic module at the same time, which is marked as module 2; S5, place the modules 1 and 2 prepared in step 4 in a damp heat aging test, observe the appearance of the solder strips of the two modules, and after DH1000h test, there is no obvious difference in appearance, after DH2000h, it is obviously observed that the solder strip at the position coated with insulating adhesive in module 1 has no obvious change, and the position not coated with insulating adhesive appears slight blackening corrosion, the corrosion area of the solder strip of module 1 is 0.8 mm 2 , and the positions coated with and not coated with insulating adhesive in module 2 both appear the same degree of blackening corrosion, and the corrosion area of the solder strip of module 2 is 15.7 mm 2The power attenuation of the test assembly 1 is -0.5% of the original, and the power attenuation of the assembly 2 is -2.63% of the original after DH2000h.

[0020] Example 2 A single-component heat-curing insulation glue for a photovoltaic BC cell is prepared by the following method: S1, color paste preparation: take 5 parts of pigment iron chromium black, 1.5 parts of adsorbing filler ZSM-5 molecular sieve, 1.5 parts of acid-absorbing filler metal-organic framework material (MOF-801), 3 parts of reaction acid filler calcium hydroxide, 0.4 parts of ultraviolet light absorber nano titanium dioxide, 0.6 parts of light stabilizer (Tinuvin 770), 10 parts of 2-functional acrylic resin (A-DCP Shin-Nakamura Chemical Co., Ltd.), 10 parts of 3-functional acrylate resin (A-TMM-3 Shin-Nakamura Chemical Co., Ltd.), 10 parts of 4-functional acrylate resin (A-TMMT Shin-Nakamura Chemical Co., Ltd.), 10 parts of 6-functional acrylate resin (A-DPH-12E Shin-Nakamura Chemical Co., Ltd.), 1 part of BYK-W9010 dispersant, use a ball mill for grinding operation, grind for 6 times, use a doctor blade fineness agent to test the grinding fineness, which is 9μm, and place the color paste at room temperature for use; S2, insulation glue preparation, take the color paste in step 1, 0.5 parts of benzoyl peroxide (BPO) initiator, 20 parts of 4-functional acrylate resin (A-TMMT Shin-Nakamura Chemical Co., Ltd.), 25 parts of 6-functional acrylate resin (A-DPH-12E Shin-Nakamura Chemical Co., Ltd.), 0.75 parts of silicone-modified polyether BYK330 leveling agent, and 0.75 parts of polyether BD3-3016 defoaming agent, disperse uniformly by a high-speed disperser, and place the uniformly dispersed insulation glue at room temperature for use; S3, take the insulation glue in step 2, select different mesh screens according to the size of the cell sheet, print on the surface of the cell sheet, and place it at 160℃ for 5min for curing; S4, prepare the cell sheet in step 3 using ordinary EVA film to prepare a photovoltaic assembly marked as assembly 3, and simultaneously use a commonly used insulation glue (without adding adsorbing filler, acid-absorbing filler, and reaction acid filler) according to the method in step 3 to process the cell sheet, and simultaneously prepare a photovoltaic assembly using ordinary EVA film, which is marked as assembly 4; S5, place the assemblies 3 and 4 prepared in step 4 in a damp heat aging test, observe the appearance of the solder strips of the two assemblies, and after DH1000h, there is no obvious difference in the appearance, and after DH2000h, it is obviously observed that the solder strip at the position coated with insulation glue in assembly 3 has no obvious change, and the position not coated with insulation glue appears slight blackening corrosion, and the corrosion area of the solder strip of assembly 3 is 1.5mm 2, the same degree of blackening corrosion occurred in the position coated with insulating glue and the position not coated with insulating glue in the assembly 4, and the corrosion area of the solder strip of the assembly 4 was 15.7mm 2 After DH2000h, the power attenuation of the test assembly 3 was-0.8% of the original, and the power attenuation of the test assembly 4 was-2.8% of the original.

[0021] Example 3 A single-component heat-curable insulating glue for a photovoltaic BC cell is prepared by the following method: S1, color paste preparation: take 5 parts of pigment titanium white, 3 parts of adsorbed filler ZSM-5 molecular sieve, 1 part of acid-absorbing filler metal-organic framework material (MOF-801), 1 part of reaction acid filler magnesium hydroxide, 0.4 part of ultraviolet light absorber nano titanium dioxide, 0.6 part of light stabilizer (Tinuvin 770), 10 parts of 2-functional acrylic resin (A-DCP Shin-Nakamura Chemical Co., Ltd.), 20 parts of 4-functional acrylate resin (A-TMMT Shin-Nakamura Chemical Co., Ltd.), 10 parts of 6-functional acrylate resin (A-DPH-12E Shin-Nakamura Chemical Co., Ltd.), 1 part of BYK-W9010 dispersant, use a ball mill for grinding operation, grind for 6 times, use a doctor blade fineness agent to test the grinding fineness, which is 8μm, and place the color paste at room temperature for use; S2, insulating glue preparation: take the color paste in step 1, 0.5 parts of benzoyl peroxide (BPO) initiator, 20 parts of 4-functional acrylate resin (A-TMMT Shin-Nakamura Chemical Co., Ltd.), 25 parts of 6-functional acrylate resin (A-DPH-12E Shin-Nakamura Chemical Co., Ltd.), 0.75 parts of silicone-modified polyether BYK330 leveling agent, and 0.75 parts of polyether BD3-3016 defoaming agent, disperse at high speed by a disperser, and place the uniformly dispersed insulating glue at room temperature for use; S3, take the insulating glue in step 2, select different mesh screens according to the size of the cell sheet, print on the surface of the cell sheet, and place it at 160℃ for 5min for curing; S4, prepare the cell sheet obtained in step 3 into a photovoltaic assembly using ordinary EVA adhesive film, which is marked as assembly 5; S5, place the assembly 5 prepared in step 4 in a damp heat aging test, observe the appearance of the solder strip of the assembly, after DH1000h, there is no obvious difference in the appearance, after DH2000h, it is obviously observed that the solder strip in the position coated with insulating glue in the assembly 5 has no obvious change, and the corrosion area of the solder strip of the assembly 5 is 3.1mm 2 After DH2000h, the power attenuation of the test assembly 5 is-0.58% of the original.

[0022] Example 4 A single-component heat-curable insulating glue for a photovoltaic BC cell is prepared by the following method: S1, color paste preparation: take 5 parts of pigment titanium dioxide, 2 parts of adsorbed filler ZSM-5 molecular sieve, 1 part of acid absorbing filler metal-organic framework material (MOF-801), 4 parts of reaction acid filler magnesium hydroxide, 0.4 parts of ultraviolet light absorber nano titanium dioxide, 0.6 parts of light stabilizer (Tinuvin 770), 10 parts of 2 functional acrylic resin (A-DCP Shin-Nakamura Chemical Industry Co., Ltd.), 20 parts of 4 functional acrylic resin (A-TMMT Shin-Nakamura Chemical Industry Co., Ltd.), 10 parts of 6 functional acrylic resin (A-DPH-12E Shin-Nakamura Chemical Industry Co., Ltd.), 1 part of BYK-W9010 dispersant, use ball mill for grinding operation, 6 times, use scraper fineness agent test grinding fineness is 8um, the color paste is placed at room temperature for standby; S2, insulation glue preparation, take the color paste in step 1, 0.5 parts of benzoyl peroxide (BPO) initiator, 20 parts of 4 functional acrylic resin (A-TMMT Shin-Nakamura Chemical Industry Co., Ltd.), 25 parts of 6 functional acrylic resin (A-DPH-12E Shin-Nakamura Chemical Industry Co., Ltd.), 0.75 parts of silicone modified polyether BYK330 leveling agent, 0.75 parts of polyether BD3-3016 defoaming agent, high speed dispersion by disperser, the uniformly dispersed insulation glue is placed at room temperature for standby; S3, take the insulation glue in step 2, select different mesh screen plate according to the size of battery piece, print on the surface of battery piece, place in 160℃ for 5min curing can be; S4, the battery piece prepared in step 3 is prepared into photovoltaic module using ordinary EVA adhesive film, which is marked as module 6; S5, the module 6 prepared in step 4 is placed in wet heat aging test, the appearance of the welding strip is observed, after DH1000h test, there is no obvious difference in the appearance, after DH2000h, it is obviously observed that there is no obvious change in the welding strip at the position of the insulation glue coated in the module 6, the corrosion area of the welding strip of the module 6 is 0.83mm 2 After DH2000h test, the power attenuation of module 5 is-0.52% of the original.

[0023] It can be seen that the single-component thermal curing insulation glue for photovoltaic BC battery can greatly reduce the corrosion area of the welding strip and improve the service life of the BC battery module compared with the insulation glue on the market.

[0024] In order to verify the effect of the adsorbed filler, the acid absorbing filler and the reaction acid filler in the insulation glue, and the influence of the preparation method of the scheme on the performance of the insulation glue, the following performance detection comparison experiments are carried out: Comparative examples 1-4 S1, color paste preparation: take 5 parts of pigment titanium dioxide, different proportions of adsorbed filler ZSM-5 molecular sieve in table 1, acid absorbing filler metal-organic framework material (MOF-801) and reaction acid filler magnesium hydroxide, 0.4 parts of ultraviolet light absorber nano titanium dioxide, 0.6 parts of light stabilizer (Tinuvin 770), 10 parts of 2 functionality propylene resin (A-DCP Shin Nakamura Chemical Co., Ltd.), 20 parts of 4 functionality acrylate resin (A-TMMT Shin Nakamura Chemical Co., Ltd.), 10 parts of 6 functionality acrylate resin (A-DPH-12E Shin Nakamura Chemical Co., Ltd.), 1 part of BYK-W9010 dispersant, use ball mill for grinding operation, grind 6 times, use scraper fineness agent test grinding fineness is 8 μm, place the color paste at room temperature for standby; S2, insulation glue preparation, take the color paste in step 1, 0.5 parts of benzoyl peroxide (BPO) initiator, 20 parts of 4 functionality acrylate resin (A-TMMT Shin Nakamura Chemical Co., Ltd.), 25 parts of 6 functionality acrylate resin (A-DPH-12E Shin Nakamura Chemical Co., Ltd.), 0.75 parts of BYK330 leveling agent, 0.75 parts of polyether BD3-3016 defoaming agent, disperse by high speed dispersion machine, place the uniformly dispersed insulation glue at room temperature for standby; S3, take the insulation glue in step 2, select different mesh screens according to the size of the battery sheet, print on the surface of the battery sheet, and place it in 160℃ for 5min for curing; S4, the battery sheet prepared in step 3 is prepared into photovoltaic module using ordinary EVA adhesive film, marked as comparative example 1 / 2 / 3 / 4; S5, place the comparative example prepared in step 4 in the hygrothermal aging test, test 1000h / 2000h, observe the appearance of the solder strip of the two groups of components, and the results are shown in table 1.

[0025] Table 1

[0026] Note: 1, film light transmittance is detected by ultraviolet spectrophotometry, the prepared insulation glue is coated on the release film by scraper, the thickness is 10 microns, after drying at 160℃ for 5min, the insulation film is torn off and placed in LAMBDA750 Perkin Elmer ultraviolet-visible spectrophotometer for detection; 2, the power attenuation of hygrothermal aging test is detected by IEC61215 standard, IEC61215 detects 1000h, while the market generally requires to detect to 2000h; 3. The corrosion area of the solder strip is measured according to the IEC61215 standard as a damp heat aging environment, and the result measurement is supplemented as follows: after the solder strip is tested for 2000 hours, a high-definition image is taken, and a clear photo of the solder strip is taken under uniform illumination using a high-definition camera or a microscope. A ruler must be placed in the photo to enable the software to convert pixels to actual size. The "polygon selection" or "free lasso" tool in the software is used to manually and accurately outline the profile of all corrosion areas. The software automatically calculates the area of the outlined region according to the set scale.

[0027] As can be seen from the test results in Table 1, only two of the adsorption filler, the acid absorption filler and the reaction acid filler are added (Comparative Examples 1-3), compared with Comparative Example 4 without the adsorption filler, the acid absorption filler and the reaction acid filler, the corrosion prevention effect of the insulating adhesive on the solder strip is only slightly improved, while the performance of Example 1 with the adsorption filler, the acid absorption filler and the reaction acid filler is significantly improved compared with Comparative Example 4, the corrosion area of the solder strip is reduced from 14.3 mm 2 to 0.8 mm 2 , and the power attenuation is increased from -2.35% to -0.5%. Therefore, the adsorption filler, the acid absorption filler and the reaction acid filler are indispensable to each other and have a synergistic effect on the significant improvement of the electrochemical corrosion of the solder strip.

[0028] In addition, as can be seen from the comparison of Examples 1-4, when the amount ratio of the adsorption filler, the acid absorption filler and the reaction acid filler changes, the film transmittance will be affected to a certain extent. For example, when the amount ratio of the three fillers in Examples 3-4 is compounded, the difference between the refractive index of the fillers and the main body resin is large, which affects the film transmittance. The reduction of the transmittance will undoubtedly reduce the light absorption of the battery piece, affecting its power generation efficiency. As can be seen from the comparison of Examples 1-2, when the mass ratio of the adsorption filler, the acid absorption filler and the reaction acid filler is (1-2):(1-2):3, the prepared insulating adhesive not only maintains good corrosion prevention performance of the solder strip, but also has higher film transmittance, which is more conducive to the power generation efficiency of the photovoltaic module.

[0029] Comparative Example 5 S1, insulation glue preparation: take 5 parts of pigment titanium dioxide, 2 parts of adsorption filler ZSM-5 molecular sieve, 1 part of acid absorption filler metal-organic framework material (MOF-801) and 3 parts of reaction acid filler magnesium hydroxide, 0.4 parts of ultraviolet light absorber nano titanium dioxide, 0.6 parts of light stabilizer (Tinuvin 770), 10 parts of 2 functionality propylene resin (A-DCP Shin Nakamura Chemical Corporation), 40 parts of 4 functionality acrylate resin (A-TMMT Shin Nakamura Chemical Corporation), 35 parts of 6 functionality acrylate resin (A-DPH-12E Shin Nakamura Chemical Corporation), 1 part of BYK-W9010 dispersant, 0.5 part of benzoyl peroxide (BPO) initiator, 0.75 part of polyether BYK330 leveling agent, 0.75 part of polyether BD3-3016 defoaming agent, high-speed dispersion by dispersion machine, and the uniformly dispersed insulation glue is placed at room temperature for standby; S2, take the insulation glue in step 1, select different mesh screens according to the size of the battery sheet, and print on the surface of the battery sheet, and place it at 160℃ for 5min; S3, the battery sheet prepared in step 2 is laminated by using ordinary EVA adhesive film.

[0030] Comparative example 5 uses the traditional insulation glue preparation process. Because heat is generated during the grinding process, the temperature is relatively high, which can cause polymerization during the grinding process, affect the performance of the insulation glue, and form clumps that are difficult to print and apply. Therefore, comparative example 5 cannot be ground in step 1. After testing, the fineness of the coating prepared in step 1 is 50μm. The insulation glue prepared in comparative example 5 has pigment sedimentation after the same storage time as the insulation glue prepared in example 1, which does not meet the shelf life of the insulation glue. Because the particle size of the insulation glue is large, the printing process in step 2 has a grainy and uneven surface. In addition, during the lamination process in step 3, the insulation glue printing problem causes partial battery sheet cracking and appearance problems, which do not meet the requirements.

[0031] As can be seen, the present application uses a two-step method. First, part of the acrylic resin is mixed with pigments, fillers, light protection agents and other additives to prepare a fine color paste after grinding. Then, the remaining acrylic resin is mixed and dispersed with initiators, leveling and defoaming aids and color paste. The coating prepared in this way has stable properties and uniform pigment distribution. The insulation glue formed after heat curing has a smooth and delicate surface, which can better protect the battery sheet.

[0032] The technical solutions provided by the present application are described in detail above. In this paper, specific examples are used to explain the principles and implementation methods of the present application. The above examples are only used to help understand the method and core idea of the present application; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation and application range will be changed; in view of the above, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A single-component heat-curing insulating adhesive for photovoltaic BC cells, characterized in that: Calculated by mass percentage, it includes the following components: Multifunctional acrylate resin 70~95wt% Adsorption filler 1~3wt% Acid-absorbing filler 1~3wt% Reactive acid filler 1~4wt% Leveling and defoaming additive 0.5~2wt% Initiator 0.1~1wt% Light protection agent 0~2wt% Pigment 0~10wt%.

2. The single-component heat-curing insulating adhesive for photovoltaic BC cells according to claim 1, characterized in that: The adsorption filler is one or more of zeolite molecular sieve, kaolin molecular sieve, zirconium powder, nano silicon dioxide, and graphene carbon molecular sieve.

3. The single-component heat-curing insulating adhesive for photovoltaic BC cells according to claim 1, characterized in that: The acid-absorbing filler is a metal-organic framework material.

4. The single-component heat-curing insulating adhesive for photovoltaic BC cells according to claim 1, characterized in that: The reactive acid filler is one or more of magnesium hydroxide, calcium hydroxide, magnesium oxide, zinc oxide, calcium oxide, and metal-organic framework materials.

5. The single-component heat-curing insulating adhesive for photovoltaic BC cells according to claim 1, characterized in that: The mass ratio of the adsorption filler, the acid absorption filler and the reaction acid filler is (1-2): (1-2):

3.

6. The one-component heat-curing insulating adhesive for photovoltaic BC cells according to claim 1, characterized in that: The functionality of the multifunctional acrylate resin is 2 to 6; the multifunctional acrylate resin is one or more of 1,9-nonanediol diacrylate, neopentyl glycol diacrylate, tricyclodecane methanol diacrylate, trimethylolpropane triacrylate, epoxidized trimethylolpropane triacrylate, pentaerythritol acrylate, dipentaerythritol polyacrylate, and epoxidized dipentaerythritol polyacrylate.

7. The single-component heat-curing insulating adhesive for photovoltaic BC cells according to claim 1, characterized in that: The leveling and defoaming aid includes one or both of a leveling agent and a defoaming agent; the leveling agent accounts for 0.25~1wt% of the total weight of the insulating glue, and the defoaming agent accounts for 0.25~1.5wt% of the total weight of the insulating glue; the leveling agent is one or both of an organosilicon-modified polyether leveling agent and an organosilicon leveling agent; the defoaming agent is one or both of a polyether defoaming agent and an organosilicon defoaming agent.

8. The single-component heat-curing insulating adhesive for photovoltaic BC cells according to claim 1, characterized in that: The initiator is one or more of benzoyl peroxide (BPO), dicumyl peroxide (DCP), tert-butyl peroxybenzoate (TBPB), and tert-butyl peroxycarbonate-2-ethylhexyl ester (TBEC).

9. The single-component heat-curing insulating adhesive for photovoltaic BC cells according to claim 1, characterized in that: The light protection agent includes one or both of an ultraviolet light absorber and a light stabilizer; the ultraviolet light absorber accounts for 0-0.75wt% of the total weight of the insulating glue, and the light stabilizer accounts for 0-1.35wt% of the total weight of the insulating glue; the ultraviolet light absorber is one or more of benzophenone, benzotriazole, triazine, zinc oxide, and nano titanium dioxide; and the light stabilizer is a hindered amine light stabilizer.

10. A method for preparing a single-component heat-curing insulating adhesive for photovoltaic BC cells according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Take 0-10 parts of pigment, 1-3 parts of adsorbent filler, 1-3 parts of acid-absorbing filler, 1-3 parts of reactive acid filler, 0-2 parts of light-protective agent, and 30-50 parts of multifunctional acrylate resin, put them into a ball mill, mix them evenly, and grind them to a fineness of 5-15 μm to prepare a color paste; S2. Take the color paste in step S1, 0.1-1 parts of initiator, 25-65 parts of multifunctional acrylate resin, and 0.5-2 parts of leveling and defoaming agent, mix them evenly to form an insulating adhesive; S3. Take the insulating glue prepared in step S2, select different mesh screens according to the size of the battery cell, print it on the surface of the battery cell, and cure it at 150-180°C for 2-5 minutes. The cured film thickness is 10-100 μm.

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