Insulating paste for photovoltaic BC battery and preparation method and application thereof

Abstract

The invention belongs to the technical field of photovoltaic insulation paste, and provides insulation paste for a photovoltaic BC battery as well as a preparation method and application of the insulation paste. The insulating glue for the photovoltaic BC battery comprises a component A and a component B which are mixed according to the weight ratio of (10-40): 1, the component A comprises polyfunctionality acrylic resin (the solid content of the polyfunctionality acrylic resin is 80-100%, the molecular weight of the polyfunctionality acrylic resin is 20000-60000, and the hydroxyl value of the polyfunctionality acrylic resin is 50-120mgKOH / g), pigment, an ultraviolet absorber, a dispersing agent, a flatting agent, a defoaming agent and a coupling agent in specific parts by weight; and the component B comprises an isocyanate curing agent and a coupling agent in specific parts by weight. The insulating glue can be quickly cured, is low in curing temperature, does not cause warping of a battery piece, also has the advantages of cost and performance (high hardness, high volume resistivity, excellent insulating property, ultraviolet aging and yellowing resistance and excellent PID resistance), and is particularly suitable for being applied to a photovoltaic BC battery.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic insulating adhesives, and in particular to an insulating adhesive for photovoltaic BC cells, and a preparation method and application thereof. Background Art

[0002] With the development of photovoltaic industry technology, XBC cell (cross-finger back contact cell) technology has gradually become one of the mainstream technologies. Among them, BC cells (back contact cells) will inevitably use insulating glue to avoid contact short circuits between the positive and negative electrodes. However, existing insulating glues such as epoxy resins generally have a long curing time (such as more than 10 minutes for thermal curing) and a high curing temperature (>200°C), which can easily damage sensitive electronic components (for example, when the insulating glue is heated at high temperature, the cell will also be affected by the high temperature and warp, thereby affecting the yield of subsequent photovoltaic modules). It is difficult to match the efficient process of photovoltaic cell production lines, resulting in limited production efficiency and is not suitable for use in photovoltaic cells such as BC cells.

[0003] In this regard, publication number CN117327453A provides a fluorescent transparent UV-curable insulating adhesive for solar cells, which comprises, by weight, 65-80 parts of an acrylate oligomer, 10-20 parts of an inorganic filler, 1-4 parts of a fluorescent agent, 0.5-3 parts of a photoinitiator, 0.1-2 parts of a silane coupling agent, 0.1-1 parts of a co-initiator, 0.1-1 parts of a polymerization inhibitor, and 5-15 parts of an active monomer. By selecting the components and controlling the content of the components, the fluorescent transparent UV-curable insulating adhesive can be UV-cured when used in solar cells. The warpage of the cell prepared with the fluorescent transparent UV-curable insulating adhesive is zero, which can effectively avoid the problems of cell bending deformation, as well as hidden cracks and fragments. However, existing fluorescent transparent UV-curable insulating adhesives for solar cells still have the disadvantages of low hardness, low volume resistivity, poor insulation performance, and poor resistance to UV aging, yellowing, and PID (potential-induced degradation) performance, making it difficult to further improve the stability and reliability of photovoltaic modules for long-term outdoor use. Summary of the Invention

[0004] The purpose of the present invention is to provide an insulating adhesive for photovoltaic BC cells and a preparation method and application thereof in view of the deficiencies in the prior art.

[0005] Based on this, the present invention discloses an insulating adhesive for photovoltaic BC cells, comprising component A and component B mixed in a weight ratio of 10-40:1;

[0006] Wherein, the component A comprises the following raw materials in parts by weight: 50-100 parts of multifunctional acrylic resin, 0-10 parts of pigment, 0-5 parts of ultraviolet light absorber, 0-0.5 parts of dispersant, 0.1-0.5 parts of leveling agent, 0.1-0.5 parts of defoaming agent and 5-10 parts of coupling agent;

[0007] The multifunctional acrylic resin has a solid content of 80-100%, a molecular weight of 20,000-60,000, and a hydroxyl value of 50-120 mgKOH / g;

[0008] Wherein, the B component comprises the following raw materials in parts by weight: 95-99 parts of isocyanate curing agent and 1-5 parts of coupling agent.

[0009] Preferably, the multifunctional acrylic resin is one or more of acrylic resin AC-166B and acrylic resin SK6328.

[0010] Preferably, the isocyanate curing agent is one or more of dicyclohexylmethane diisocyanate (HMDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and hexamethylene diisocyanate isocyanurate trimer.

[0011] Preferably, the coupling agent is one or more of a silane coupling agent (such as organosilicon silane coupling agent S3613, KH570, KH560), a silane oligomer, and a titanate coupling agent.

[0012] Further preferably, the curing temperature of the insulating adhesive layer is 175-180° C., and the curing time is 2-8 minutes.

[0013] Preferably, the pigment is one or more of titanium dioxide, barium sulfate, carbon black, copper chrome black, iron chrome black, cobalt chrome blue, phthalocyanine blue, malachite green, and phthalocyanine green.

[0014] Preferably, the ultraviolet light absorber is a triazine-type ultraviolet light absorber (such as triazine-type ultraviolet light absorbers TINUVIN400, UV479, UV5405) and / or a benzophenone-type ultraviolet light absorber (such as benzophenone-type ultraviolet light absorber UV531).

[0015] Preferably, the dispersant is one or more of anionic dispersants (such as sodium dodecylbenzenesulfonate, sodium polyacrylate dispersants), nonionic dispersants (such as polyether dispersants TPE-1000, PPE-1500, GPE-3000; and fatty acid ester dispersants PEG400MS, PEG400MO);

[0016] The leveling agent is an organosilicon-modified polyether leveling agent (such as organosilicon-modified polyether leveling agent BYK330, BYK331, BYK332) and / or an organosilicon leveling agent (such as organosilicon leveling agent DC11, DC29);

[0017] The defoaming agent is a polyether defoaming agent (such as polyether defoaming agent BD3-3016, SGR1800) and / or an organosilicon defoaming agent (such as organosilicon defoaming agent KSZ-108, DS-4040, 4080).

[0018] The present invention also discloses a method for preparing an insulating adhesive for photovoltaic BC cells, comprising the following preparation steps:

[0019] S1. Mix 0-10 parts of pigment, 0-5 parts of UV absorber, 50-60 parts of multifunctional acrylic resin and 0-0.5 parts of dispersant by weight, disperse evenly, and grind to a fineness of 5-15 μm to prepare a color paste mixture;

[0020] S2. Take the color paste mixture from step S1, add 0-40 parts of multifunctional acrylic resin, 0.1-0.5 parts of leveling agent, 0.1-0.5 parts of defoaming agent, and 5-10 parts of coupling agent, and disperse evenly (preferably using a disperser at 500-1500 rpm for 1-3 hours) to obtain component A;

[0021] S3. Mix 95-99 parts of isocyanate and 1-5 parts of coupling agent by weight, and disperse them uniformly (preferably using a disperser at 500-1500 r / min for 0.5-1 h) to obtain component B;

[0022] S4. Component A and component B are mixed in a weight ratio of 10-40:1, and dispersed evenly (preferably using a disperser at 500-1500 r / min for 0.5-1 h) to obtain the insulating adhesive.

[0023] The present invention also discloses an application of an insulating adhesive for photovoltaic BC cells, wherein the insulating adhesive for photovoltaic BC cells described above is applied to the surface of the photovoltaic BC cells.

[0024] Compared with the prior art, the present invention has at least the following beneficial effects:

[0025] The insulating adhesive for photovoltaic BC cells of the present invention requires that component A and component B be evenly mixed in a weight ratio of 10-40:1 before use; the insulating adhesive can quickly form a dense insulating adhesive layer with strong bonding to the photovoltaic cell sheet at a relatively low curing temperature, and the insulating adhesive layer also has strong bonding to the welding ribbon and photovoltaic packaging film (such as EVA packaging film, EPE packaging film, POE packaging film, etc.), which helps to firmly bond the welding ribbon, photovoltaic packaging film, etc. to the photovoltaic cell sheet through the insulating adhesive layer. Moreover, since the rapid curing temperature of the insulating adhesive layer applied to the surface of the photovoltaic BC cell is lower than 200°C, it will not cause adverse effects such as warping of the photovoltaic cell and can match the efficient process of the photovoltaic cell production line; moreover, the insulating adhesive layer applied to the surface of the photovoltaic BC cell also has the following performance advantages: high hardness (hardness up to 5H), high volume resistivity, excellent insulation performance (volume resistivity can be as high as 1.4×10^16Ω·cm), good resistance to UV500KwH aging and yellowing, and excellent anti-PID performance (PID test (-1500V, 85°C) 96 hours without leakage), etc.; therefore, the insulating adhesive for photovoltaic BC cells of the present invention has both cost and performance advantages, is particularly suitable for application on the surface of photovoltaic BC cells, and can effectively improve the stability and reliability of photovoltaic modules for long-term outdoor use. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with specific embodiments.

[0027] Example 1

[0028] The method for preparing an insulating adhesive for photovoltaic BC cells of this embodiment includes the following preparation steps:

[0029] Step S1: 8 parts (by weight, the same below) of titanium dioxide, 30 parts of acrylic resin AC-166B, 20 parts of acrylic resin SK6328, and 0.5 parts of anionic dispersant sodium dodecylbenzenesulfonate were mixed and dispersed continuously for 1 hour using a disperser at 1000 r / min. The mixture was transferred to a ball mill and ground to a fineness of 10 μm. The mixture was filtered through a 250-mesh filter cloth to prepare a color paste mixture, which was then allowed to stand for use.

[0030] Step S2: Take the color paste mixture of step S1, add 35 parts of acrylic resin AC-166B, 0.25 parts of silicone modified polyether leveling agent BYK332, 0.25 parts of silicone defoaming agent KSZ-108, and 6 parts of silicone coupling agent KH570, and use a disperser at 800 r / min to continuously disperse for 2 hours. After uniform dispersion, component A of the insulating adhesive can be obtained.

[0031] Step S3: Take 97 parts of an isocyanate curing agent mixture (the isocyanate curing agent mixture includes dicyclohexylmethane diisocyanate HMDI, hexamethylene diisocyanate HDI and hexamethylene diisocyanate isocyanurate trimer mixed in a weight ratio of 2:3:5) and 3 parts of an organosilicon coupling agent (such as the silane coupling agent S3613 of Shandong Sike New Materials Co., Ltd.), mix them, and use a disperser at 1000 r / min to continuously disperse for 0.5 h. After uniform dispersion, component B of the insulating adhesive can be obtained.

[0032] Step S4: Mix component A in step S2 and component B in step S3 in a weight ratio of 20:1 (i.e., component A: component B = 20), and use a disperser at 1000 r / min to continuously disperse for 0.5 h. After uniform dispersion, the insulating adhesive of this embodiment can be obtained.

[0033] The application of the insulating adhesive for photovoltaic BC cells prepared in this embodiment is to apply the insulating adhesive to photovoltaic BC cells. The specific application method is as follows:

[0034] Step S5: Lay the customized 300-mesh silk screen on the surface of the photovoltaic BC cell, print the insulating glue prepared in step S4 of this embodiment on the surface of the photovoltaic BC cell, and bake it at 180°C for 4 minutes to obtain an insulating glue layer on the surface of the photovoltaic BC cell.

[0035] The performance test of the insulating adhesive layer on the surface of the photovoltaic BC cell of this embodiment was carried out, and the test results are as follows:

[0036] The thickness of the insulating adhesive layer on the surface of the photovoltaic BC cell is 25 microns, its hardness is 5H, and its volume resistivity is 1.3×10^16Ω·cm.

[0037] Furthermore, the photovoltaic BC cells with an insulating adhesive layer on their surfaces, prepared in step S5 of this example, were laminated with various encapsulating films (e.g., EVA, EPE, and POE) to produce photovoltaic modules. Aging performance testing of the photovoltaic modules produced in this example revealed the following test results: After a UV500KwH aging test, the yellowing value of the insulating adhesive layer region was ≤4.2, and the photovoltaic modules showed no leakage after a PID test (-1500V, 85°C) for 96 hours.

[0038] Example 2

[0039] The method for preparing an insulating adhesive for photovoltaic BC cells of this embodiment includes the following preparation steps:

[0040] Step S1: 5 parts (by weight, the same below) of ultraviolet absorber (the ultraviolet absorber includes TINUVIN400, UV531 and UV5405 mixed in a weight ratio of 1:8:1), 25 parts of acrylic resin AC-166B, 25 parts of acrylic resin SK6328, and 0.5 parts of anionic dispersant sodium dodecylbenzenesulfonate are mixed, and then dispersed continuously for 1 hour using a disperser at 1000 r / min. The mixture is transferred to a ball mill and ground to a fineness of 10 microns. After filtering through a 250-mesh filter cloth, a color paste mixture is prepared and allowed to stand for use.

[0041] Step S2: Take the color paste mixture of step S1, add 39 parts of acrylic resin AC-166B, 0.25 parts of silicone modified polyether leveling agent BYK332, 0.25 parts of silicone defoaming agent KSZ-108, and 5 parts of silicone coupling agent (such as silane coupling agent S3613 from Shandong Sike New Materials Co., Ltd.), and use a disperser at 800 r / min to continuously disperse for 2 hours. After uniform dispersion, component A of the insulating adhesive can be obtained.

[0042] Step S3: Take 96 parts of an isocyanate curing agent mixture (the isocyanate curing agent mixture includes HMDI, HDI, and hexamethylene diisocyanate isocyanurate trimer mixed in a weight ratio of 3:1:6) and 4 parts of an organosilicon coupling agent KH560, mix them, and use a disperser at 1000 r / min to continuously disperse for 0.5 h. After uniform dispersion, component B of the insulating adhesive can be obtained.

[0043] Step S4: Mix component A in step S2 and component B in step S3 in a weight ratio of 10:1 (i.e., component A: component B = 10), and use a disperser at 1000 r / min to continuously disperse for 0.5 h. After uniform dispersion, the insulating adhesive of this embodiment can be obtained.

[0044] The application of the insulating adhesive for photovoltaic BC cells prepared in this embodiment is to apply the insulating adhesive to photovoltaic BC cells. The specific application method is as follows:

[0045] Step S5: Lay the customized 200-mesh silk screen on the surface of the photovoltaic BC cell, print the insulating glue prepared in step S4 of this embodiment on the surface of the photovoltaic BC cell, and bake it at 180°C for 3 minutes to obtain an insulating glue layer on the surface of the photovoltaic BC cell.

[0046] The performance test of the insulating adhesive layer on the surface of the photovoltaic BC cell of this embodiment was carried out, and the test results are as follows:

[0047] The thickness of the insulating adhesive layer on the surface of the photovoltaic BC cell is 32 microns, its hardness is 5H, and its volume resistivity is 1.4×10^16Ω·cm.

[0048] The photovoltaic BC cells with an insulating adhesive layer on their surfaces, prepared in step S5 of this example, were laminated with various encapsulating films (e.g., EVA, EPE, and POE) to produce photovoltaic modules. Aging performance testing of the photovoltaic modules produced in this example revealed the following test results: After a UV500KwH aging test, the yellowing value of the insulating adhesive layer region was ≤5.0. The photovoltaic modules showed no leakage after a PID test (-1500V, 85°C) for 96 hours.

[0049] Comparative Example 1

[0050] The preparation method of an insulating adhesive for photovoltaic BC cells in this comparative example includes the following preparation steps:

[0051] In step S1 of this comparative example, 30 parts of acrylic resin AC-166B and 20 parts of acrylic resin SK6328 in Example 1 were replaced with 50 parts of acrylic resin 7364-S-60 (solid content 60%, hydroxyl value 45 mgKOH / g) in this comparative example; the remaining raw material formula and process of step S1 of this comparative example were the same as step S1 of Example 1, to obtain the color paste mixture of this comparative example.

[0052] In step S2 of this comparative example, 35 parts of acrylic resin AC-166B in Example 1 are replaced with 35 parts of acrylic resin 7364-S-60 in this comparative example. The remaining raw material formula and process of step S2 of this comparative example are the same as those of step S2 of Example 1, thereby obtaining component A of the insulating adhesive of this comparative example.

[0053] Step S3 of this comparative example refers to step S3 of Example 1, so as to obtain component B of the insulating adhesive of this comparative example.

[0054] In step S4 of this comparative example, according to the same cyanide-hydroxyl ratio as in Example 1, component A of step S2 of this comparative example and component B of step S3 are mixed, and then dispersed continuously for 0.5 h using a disperser at 1000 r / min. After uniform dispersion, the insulating adhesive of this comparative example can be obtained.

[0055] The application of the insulating adhesive for photovoltaic BC cells prepared in this comparative example is to apply the insulating adhesive to photovoltaic BC cells. The specific application method is the same as step S5 of Example 1, and the insulating adhesive layer of this comparative example can be prepared on the surface of the photovoltaic BC cells.

[0056] The performance test of the insulating adhesive layer on the surface of the photovoltaic BC cell of this comparative example was carried out, and the test results are as follows:

[0057] The thickness of the insulating adhesive layer on the surface of the photovoltaic BC cell is 25 microns, its hardness is 2H, and its volume resistivity is 0.5×10^16Ω·cm.

[0058] The photovoltaic BC cells with an insulating adhesive layer on their surfaces, prepared in step S5 of this comparative example, were laminated with various encapsulating films (e.g., EVA, EPE, and POE). Aging performance testing of the photovoltaic modules prepared in this comparative example was performed, and the test results were as follows: After a UV500KwH aging test, the yellowing value of the insulating adhesive layer region was ≤5.0. After a PID test (-1500V, 85°C) for 96 hours, the photovoltaic modules exhibited a positive and negative short circuit.

[0059] Comparative Example 2

[0060] The preparation method of an insulating adhesive for photovoltaic BC cells in this comparative example includes the following preparation steps:

[0061] In step S1 of this comparative example, 30 parts of acrylic resin AC-166B and 20 parts of acrylic resin SK6328 in Example 1 were replaced by: 50 parts of acrylic resin (solid content 70%, hydroxyl value 165 mgKOH / g) synthesized according to the preparation method of Example 1 of CN118546488A in this comparative example; the remaining raw material formula and process of step S1 of this comparative example were referred to step S1 of Example 1, to obtain the color paste mixture of this comparative example.

[0062] In step S2 of this comparative example, 35 parts of acrylic resin AC-166B in Example 1 are replaced with: 35 parts of acrylic resin synthesized according to the preparation method of Example 1 of CN118546488A in this comparative example; the remaining raw material formula and process of step S2 of this comparative example are the same as those of step S2 of Example 1, to obtain component A of the insulating adhesive of this comparative example.

[0063] Step S3 of this comparative example refers to step S3 of Example 1, so as to obtain component B of the insulating adhesive of this comparative example.

[0064] In step S4 of this comparative example, according to the same cyanide-hydroxyl ratio as in Example 1, component A of step S2 of this comparative example and component B of step S3 are mixed, and then dispersed continuously for 0.5 h using a disperser at 1000 r / min. After uniform dispersion, the insulating adhesive of this comparative example can be obtained.

[0065] The application of the insulating adhesive for photovoltaic BC cells prepared in this comparative example is to apply the insulating adhesive to photovoltaic BC cells. The specific application method is the same as step S5 of Example 1, and the insulating adhesive layer of this comparative example can be prepared on the surface of the photovoltaic BC cells.

[0066] The performance test of the insulating adhesive layer on the surface of the photovoltaic BC cell of this comparative example was carried out, and the test results are as follows:

[0067] The thickness of the insulating adhesive layer on the surface of the photovoltaic BC cell is 25 microns, its hardness is H, and its volume resistivity is 0.8×10^16Ω·cm.

[0068] The photovoltaic BC cells with an insulating adhesive layer on their surfaces, prepared in step S5 of this comparative example, were laminated with various encapsulating films (e.g., EVA, EPE, and POE). The photovoltaic modules prepared in this comparative example were subjected to aging performance testing. The test results were as follows: After UV500KwH aging testing, the yellowing value of the insulating adhesive layer area was ≤5.0. Bubbles were observed in the insulating adhesive layer on the surface of the photovoltaic BC cells in this comparative example. However, the photovoltaic modules showed no leakage after 96 hours of PID testing (-1500V, 85°C).

[0069] In summary, combined with the test data of Examples 1-2, it can be seen that: the insulating glue for photovoltaic BC cells in Examples 1-2 can be quickly cured into a film, and the curing temperature is relatively low (below 200°C), which will not cause adverse effects such as warping of photovoltaic cells, and can match the efficient process of photovoltaic cell production lines; moreover, the insulating glue for photovoltaic BC cells in Examples 1-2 has the performance advantages of high hardness, high volume resistivity, excellent insulation performance, resistance to UV aging and yellowing, and excellent anti-PID performance.

[0070] Combining the test data of Example 1 and Comparative Example 1, it can be seen that: compared with Example 1, the insulating adhesive for photovoltaic BC cells in Comparative Example 1 is replaced with an acrylic resin with a low solid content and hydroxyl value while keeping the other raw material formulas unchanged. The crosslinking density of the insulating adhesive layer is reduced, and the solvent volatilization during the baking and curing process will also cause holes of varying degrees to appear in the insulating adhesive layer. Therefore, compared with Example 1, the insulating adhesive layer on the surface of the photovoltaic BC cell in Comparative Example 1 has a lower hardness and a lower volume resistivity. Moreover, compared with Example 1, the yellowing value of the insulating adhesive layer area of ​​the photovoltaic module of Comparative Example 1 after the UV500KwH aging test is slightly increased, and its photovoltaic module has a short circuit after the PID test.

[0071] Furthermore, combining the test data of Example 1 and Comparative Example 2, it can be seen that: compared with Example 1, the insulating adhesive for photovoltaic BC cells in Comparative Example 2, while maintaining the same raw material formula, is replaced with an acrylic resin with excessively high solid content and hydroxyl value. This results in a longer curing time for the insulating adhesive layer. Baking at 180°C for 4 minutes does not completely cure the insulating adhesive layer. Incomplete curing also easily causes the remaining material in the insulating adhesive layer to react with the encapsulating adhesive film, producing bubbles, which in turn leads to poor reliability of the photovoltaic module. Therefore, compared with Example 1, the insulating adhesive layer on the surface of the photovoltaic BC cell in Comparative Example 2 has a lower hardness and lower volume resistivity. Moreover, compared with Example 1, the yellowing value of the insulating adhesive layer area of ​​the photovoltaic module in Comparative Example 2 after UV500KwH aging test is slightly increased.

[0072] Therefore, the insulating adhesive for photovoltaic BC cells of the present invention is combined with an acrylic resin with a specific solid content and hydroxyl value (the solid content and hydroxyl value of the acrylic resin cannot be too low or too high) on the basis of keeping other raw material formulas unchanged; it can not only improve the hardness and volume resistivity of the insulating adhesive layer printed on the surface of the photovoltaic BC cell, but also improve the UV500KwH aging and yellowing resistance and PID resistance of the prepared photovoltaic module, and can effectively improve the stability and reliability of the photovoltaic module in long-term outdoor use.

[0073] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic creative concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0074] The technical solution provided by the present invention is introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An insulating adhesive for photovoltaic BC cells, characterized in that: The method comprises mixing component A and component B in a weight ratio of 10-40:1; Wherein, the component A comprises the following raw materials in parts by weight: 50-100 parts of multifunctional acrylic resin, 0-10 parts of pigment, 0-5 parts of ultraviolet light absorber, 0-0.5 parts of dispersant, 0.1-0.5 parts of leveling agent, 0.1-0.5 parts of defoaming agent and 5-10 parts of coupling agent; The multifunctional acrylic resin has a solid content of 80-100%, a molecular weight of 20,000-60,000, and a hydroxyl value of 50-120 mgKOH / g; Wherein, the B component comprises the following raw materials in parts by weight: 95-99 parts of isocyanate curing agent and 1-5 parts of coupling agent.

2. The insulating adhesive for photovoltaic BC cells according to claim 1, characterized in that: The multifunctional acrylic resin is one or more of acrylic resin AC-166B and acrylic resin SK6328.

3. The insulating adhesive for photovoltaic BC cells according to claim 1, characterized in that: The isocyanate curing agent is one or more of dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate isocyanurate trimer.

4. The insulating adhesive for photovoltaic BC cells according to claim 1, characterized in that: The coupling agent is one or more of a silane coupling agent, a silane oligomer, and a titanate coupling agent.

5. The insulating adhesive for photovoltaic BC cells according to any one of claims 1 to 4, characterized in that: The curing temperature of the insulating adhesive layer is 175-180° C., and the curing time is 2-8 minutes.

6. The insulating adhesive for photovoltaic BC cells according to claim 1, characterized in that: The pigment is one or more of titanium dioxide, barium sulfate, carbon black, copper chrome black, iron chrome black, cobalt chrome blue, phthalocyanine blue, malachite green, and phthalocyanine green.

7. The insulating adhesive for photovoltaic BC cells according to claim 1, characterized in that: The ultraviolet light absorber is a triazine type ultraviolet light absorber and / or a benzophenone type ultraviolet light absorber.

8. The insulating adhesive for photovoltaic BC cells according to claim 1, characterized in that: The dispersant is one or more of sodium dodecylbenzene sulfonate, sodium polyacrylate dispersant, polyether dispersant, and fatty acid ester dispersant; The leveling agent is an organosilicon-modified polyether leveling agent and / or an organosilicon leveling agent; The defoamer is a polyether defoamer and / or an organosilicon defoamer.

9. The method for preparing an insulating adhesive for photovoltaic BC cells according to any one of claims 1 to 8, characterized in that: The method comprises the following preparation steps: S1. Mix 0-10 parts of pigment, 0-5 parts of UV absorber, 50-60 parts of multifunctional acrylic resin and 0-0.5 parts of dispersant by weight, disperse evenly, and grind to a fineness of 5-15 μm to prepare a color paste mixture; S2. Take the color paste mixture from step S1, add 0-40 parts of multifunctional acrylic resin, 0.1-0.5 parts of leveling agent, 0.1-0.5 parts of defoaming agent and 5-10 parts of coupling agent, and disperse evenly to obtain component A; S3. Mix 95-99 parts of isocyanate and 1-5 parts of coupling agent by weight and disperse them evenly to obtain component B; S4. Mix component A and component B in a weight ratio of 10-40:1 and disperse them evenly to obtain the insulating adhesive.

10. Application of the insulating adhesive for photovoltaic BC cells according to any one of claims 1 to 8, characterized in that: The insulating glue is applied to the surface of the photovoltaic BC cell.