A welding wire adhesive for photovoltaic OBB modules, its preparation method and application

Abstract

This invention relates to the field of solar photovoltaic technology, and more particularly to a welding wire adhesive for photovoltaic OBB modules, its preparation method, and its application. The welding wire adhesive for photovoltaic OBB modules, by weight, comprises the following components: 20-50 parts vinyl silicone resin, 20-50 parts vinyl silicone oil, 10-20 parts octavinyldimethylsiloxycage polysilsesquioxane, 1-10 parts heptaisobutyltrisilyl alcoholcage polysilsesquioxane, 0.5-3 parts methacryloyloxypropylcyclotetrasiloxane, 0.5-3 parts acryloyloxypropylcage polysilsesquioxane, 5-20 parts thixotropic agent, 1-10 parts hydrogen-containing silicone oil, and 0.05-2 parts anti-poisoning microcapsule catalyst. The welding wire adhesive for photovoltaic OBB modules prepared by this invention exhibits excellent adhesion to low-temperature welding wires, resistance to yellowing, low volatility at high temperatures, and good high and low temperature impact resistance.

Description

Technical Field

[0001] This invention relates to the field of solar photovoltaic technology, and in particular to a welding wire adhesive for photovoltaic OBB modules, its preparation method and application. Background Technology

[0002] Traditional PERC, new TOPcon, and HJT (heterojunction) batteries, especially HJT batteries, require a large amount of silver paste. Under the premise of energy saving and cost reduction, reducing the use of silver paste has become one of the important ways to reduce costs.

[0003] Gridless modules, also known as OBB technology, are an innovative photovoltaic (PV) module technology. This technology eliminates the traditional grid of solar cells, instead using solder ribbons to conduct current in the module assembly. Specifically, gridless cells use solder ribbons to collect current through a fine grid and interconnect cells; the width of the solder ribbons is smaller than that of traditional grids. Furthermore, gridless cells typically use copper solder ribbons, completely replacing the original silver electrode grid, thus realizing the function of base metals in place of traditional silver grids. The advantages of OBB are: 1) reduced silver loss; 2) enhanced conductivity; 3) low-temperature encapsulation processes that can accommodate thinner silicon wafers.

[0004] Currently, OBB solder ribbon bonding mainly uses UV adhesives, thermosetting epoxy adhesives, and thermosetting silicone adhesives. Among them, UV-curable materials have been widely studied and rapidly promoted in various industries due to their numerous outstanding advantages such as fast curing speed, environmental friendliness, low energy consumption, and no solvent evaporation. However, UV-curable adhesives also have their limitations. Conventional UV-curable adhesives have significant limitations in applications involving yellowing resistance and small molecule migration, and UV curing can cause some damage to the solar cells. Epoxy adhesives have high adhesion to solder wires, but they are brittle and prone to yellowing. Silicone systems have natural aging resistance, but their adhesion strength to solder ribbons is low. In OBB packaging applications, the solder wire used is tin-plated copper low-temperature solder wire. To ensure good adhesion between the solder wire and the grid line during lamination, flux is usually added, but this flux can affect the curing of the adhesive and the adhesion strength. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a welding wire adhesive for photovoltaic OBB modules, its preparation method and application.

[0006] To achieve the above objectives, the technical solution adopted is:

[0007] One objective of this invention is to provide a welding wire adhesive for photovoltaic OBB modules, comprising the following components by weight: 20-50 parts vinyl silicone resin, 20-50 parts vinyl silicone oil, 10-20 parts octavinyldimethylsiloxycage polysilsesquioxane, 1-10 parts heptaisobutyltrisilyl alcoholcage polysilsesquioxane, 0.5-3 parts methacryloyloxypropylcyclotetrasiloxane, 0.5-3 parts acryloyloxypropylcage polysilsesquioxane, 5-20 parts thixotropic agent, 1-10 parts hydrogen-containing silicone oil, and 0.05-2 parts anti-poisoning microcapsule catalyst.

[0008] Preferably, the vinyl silicone resin is an MQ silicone resin containing vinyl groups, with a vinyl content of 1%-2% by mass and a viscosity of 4000-8000 mPa·s.

[0009] Preferably, the vinyl silicone oil is a vinyl dual-sealed silicone oil with a viscosity of 5000-10000 mPa·s and a vinyl content of 0.15%-0.17% by mass.

[0010] More preferably, the viscosity of the vinyl silicone oil is 5000-6000 mPa·s.

[0011] Preferably, the octavinyldimethylsiloxycage polysilsesquioxane ( POSS106 is an organic-inorganic hybrid cage-like polysilsesquioxane with a molecular size of 1.5 nm, and its structure is as follows:

[0012] .

[0013] Preferably, the heptaisobutyltrisilyl alcohol cage-like polysilsesquioxane ( POSS201 is an organic-inorganic hybrid cage-like polysilsesquioxane with a molecular size of 1.5 nm, and its structure is as follows:

[0014] .

[0015] Preferably, the methacryloyloxypropylcyclotetrasiloxane ( CTS102 is an organic-inorganic hybrid cyclotetrasiloxane with a viscosity of 100-300 mPa·s and the following structure:

[0016] .

[0017] Preferably, the acryloyloxypropyl cage-type polysilsesquioxane ( POSS1013 is an organic-inorganic hybrid cage-like polysilsesquioxane with a molecular size in the nanometer range, a viscosity of 1800-2200 mPa·s, and a structure as follows:

[0018]

[0019] Preferably, the hydrogen-containing silicone oil is a silicone oil with H-terminated and drooping H functional bonds, and has a hydrogen content of 5.0-10.0 mmoles / g, with the following structure:

[0020]

[0021] Where M = 1 to 10, D = 1 to 10.

[0022] Preferably, the anti-poisoning microcapsule catalyst is a microcapsule-type platinum catalyst;

[0023] Preferably, the thixotropic agent is a hydrophobic fumed silica or a hydrophilic fumed silica. The hydrophilic fumed silica is at least one of Wacker's T40, Evonik's A300, and A380; the hydrophobic fumed silica is at least one of Wacker's H30, Evonik's R202, R972, and R974, and more preferably a hydrophobic fumed silica.

[0024] The second objective of this invention is to provide a method for preparing a welding wire adhesive for photovoltaic OBB modules, comprising the following steps: adding 20-50 parts of vinyl silicone resin, 20-50 parts of vinyl silicone oil, 10-20 parts of octavinyldimethylsiloxycage polysilsesquioxane, 1-10 parts of heptaisobutyltrisilyl alcoholcage polysilsesquioxane, 0.5-3 parts of methacryloyloxypropylcyclotetrasiloxane, and 0.5-3 parts of acryloyloxypropylcage polysilsesquioxane to a reaction vessel and stirring, setting the temperature to 80°C, stirring for 3 hours, then naturally cooling to room temperature, adding 5-20 parts of a thixotropic agent, and continuing to stir at room temperature for 1 hour, adding 1-10 parts of hydrogen-containing silicone oil and 0.05-2 parts of an anti-poisoning microcapsule catalyst, and stirring at room temperature for 1 hour to obtain the welding wire adhesive for photovoltaic OBB modules.

[0025] The third objective of this invention is to provide an application of the aforementioned welding wire adhesive for photovoltaic OBB modules in the field of photovoltaic OBB modules.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows: The adhesive for welding wire in photovoltaic OBB modules described in this invention primarily provides strength to the silicon system. The vinyl content is controlled at 1%-2%. Too low a viscosity will cause brittleness, while too high a viscosity will cause problems with processability. Therefore, controlling the viscosity of the vinyl silicone oil to 5000-6000 mPa·s is most suitable. The introduction of octavinyldimethylsiloxy cage-like polysilsesquioxane mainly improves the wear resistance and hardness of the product. Secondly, the introduction of the cage-like polysilsesquioxane structure provides excellent adhesion to the welding wire. The introduction of heptaisobutyltrisilyl alcohol cage-like polysilsesquioxane mainly benefits the viscosity stability of addition-cure silicone due to the presence of hydroxyl groups in its structure. Secondly, it also greatly helps the adhesion of the welding wire; the introduction of methacryloyloxypropylcyclotetrasiloxane and acryloyloxypropyl cage-type polysilsesquioxane mainly improves the adhesion of the welding wire. The structure of cage-type polysilsesquioxane has good wettability with metal, especially after the addition of flux, its strength decay is low; the addition of thixotropic agent must ensure a certain glue height after printing, as well as its transparency and printing process characteristics; the introduction of anti-poisoning catalyst mainly ensures its curing speed and stability. The flux on the surface of the welding wire will affect the platinum catalyst, but the anti-poisoning catalyst will not be affected by this. Detailed Implementation

[0027] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0028] Example 1

[0029] 30 parts of vinyl silicone resin with a viscosity of 6000 mPa·s and a vinyl content of 1.2%, 40 parts of vinyl silicone oil with a viscosity of 7000 mPa·s and a vinyl content of 0.15%, 10 parts of octavinyldimethylsiloxycage polysilsesquioxane, 5 parts of heptaisobutyltrisilyl alcohol cage polysilsesquioxane, 2 parts of methacryloyloxypropylcyclotetrasiloxane, and 2 parts of acryloyloxypropylcage polysilsesquioxane were added to a reaction vessel and stirred. The temperature was set to 80℃ and stirred for 3 hours. Then, the mixture was allowed to cool naturally to room temperature. 10 parts of H30 thixotropic agent were added, and stirring was continued at room temperature for 1 hour. 5 parts of 6.0 mmoles / g hydrogen-containing silicone oil and 1 part of Jiangmen Kejunchi PT-2500D anti-poisoning microcapsule catalyst were added, and the mixture was stirred at room temperature for 1 hour to obtain the OBB component welding wire adhesive, which was then sealed and stored.

[0030] Example 2

[0031] 40 parts of vinyl silicone resin with a viscosity of 7000 mPa·s and a vinyl content of 1.2%, 30 parts of vinyl silicone oil with a viscosity of 6000 mPa·s and a vinyl content of 0.15%, 15 parts of octavinyldimethylsiloxycage polysilsesquioxane, 5 parts of heptaisobutyltrisilyl alcohol cage polysilsesquioxane, 2 parts of methacryloyloxypropylcyclotetrasiloxane, and 2 parts of acryloyloxypropylcage polysilsesquioxane were added to a reaction vessel and stirred. The temperature was set to 80℃ and stirred for 3 hours. Then, the mixture was allowed to cool naturally to room temperature. 10 parts of H30 thixotropic agent were added, and stirring was continued at room temperature for 1 hour. 5 parts of 6.0 mmoles / g hydrogen-containing silicone oil and 1 part of Jiangmen Kejunchi PT-2500D anti-poisoning microcapsule catalyst were added, and the mixture was stirred at room temperature for 1 hour to obtain the OBB component welding wire adhesive, which was then sealed and stored.

[0032] Example 3

[0033] 30 parts of vinyl silicone resin with a viscosity of 6000 mPa·s and a vinyl content of 1.2%, 40 parts of vinyl silicone oil with a viscosity of 7000 mPa·s and a vinyl content of 0.15%, 15 parts of octavinyldimethylsiloxycage polysilsesquioxane, 8 parts of heptaisobutyltrisilyl alcohol cage polysilsesquioxane, 2 parts of methacryloyloxypropylcyclotetrasiloxane, and 2 parts of acryloyloxypropylcage polysilsesquioxane were added to a reaction vessel and stirred. The temperature was set at 80℃ and stirred for 3 hours. Then, the mixture was allowed to cool naturally to room temperature. 10 parts of H30 thixotropic agent were added, and stirring was continued at room temperature for 1 hour. 5 parts of 6.0 mmoles / g hydrogen-containing silicone oil and 1 part of Jiangmen Kejunchi PT-2500D anti-poisoning microcapsule catalyst were added, and the mixture was stirred at room temperature for 1 hour to obtain the OBB component welding wire adhesive, which was then sealed and stored.

[0034] Comparative Example 1

[0035] 30 parts of vinyl silicone resin with a viscosity of 6000 mPa·s and a vinyl content of 1.2%, 40 parts of vinyl silicone oil with a viscosity of 7000 mPa·s and a vinyl content of 0.15%, 10 parts of ordinary type DY-VMQ102 vinyl dimethyl silicone resin, 5 parts of heptaisobutyltrisilyl alcohol cage-like polysilsesquioxane, 2 parts of methacryloyloxypropylcyclotetrasiloxane, and 2 parts of acryloyloxypropyl cage-type polysilsesquioxane were added to a reaction vessel and stirred. The temperature was set at 80℃ and stirred for 3 hours. Then, the mixture was allowed to cool naturally to room temperature. 10 parts of H30 thixotropic agent were added and the mixture was stirred at room temperature for another hour. 5 parts of 6.0 mmoles / g hydrogen-containing silicone oil and 1 part of Jiangmen Kejunchi PT-2500D anti-poisoning microcapsule catalyst were added and stirred at room temperature for another hour to obtain the OBB component welding wire adhesive, which was then sealed and stored.

[0036] Comparative Example 2

[0037] 30 parts of vinyl silicone resin with a viscosity of 6000 mPa·s and a vinyl content of 1.2%, 40 parts of vinyl silicone oil with a viscosity of 7000 mPa·s and a vinyl content of 0.15%, 10 parts of octavinyldimethylsiloxy cage-like polysilsesquioxane, 5 parts of heptaisobutyltrisilyl alcohol cage-like polysilsesquioxane, and 4 parts of commercially available KH-570 siloxane were added to a reaction vessel and stirred. The temperature was set to 80℃ and stirred for 3 hours. Then, the mixture was allowed to cool naturally to room temperature. 10 parts of H30 thixotropic agent were added, and the mixture was stirred at room temperature for another hour. 5 parts of 6.0 mmoles / g hydrogen-containing silicone oil and 1 part of Jiangmen Kejunchi PT-2500D anti-poisoning microcapsule catalyst were added, and the mixture was stirred at room temperature for another hour to obtain the OBB component welding wire adhesive. The adhesive was then sealed and stored.

[0038] Comparative Example 3

[0039] 30 parts of vinyl silicone resin with a viscosity of 6000 mPa·s and a vinyl content of 1.2%, 40 parts of vinyl silicone oil with a viscosity of 7000 mPa·s and a vinyl content of 0.15%, 15 parts of octavinyldimethylsiloxy cage-like polysilsesquioxane, and 4 parts of commercially available KH-570 siloxane were added to a reaction vessel and stirred. The temperature was set to 80℃ and stirred for 3 hours. Then, the mixture was allowed to cool naturally to room temperature. 10 parts of H30 thixotropic agent were added, and stirring was continued at room temperature for 1 hour. 5 parts of 6.0 mmoles / g hydrogen-containing silicone oil and 1 part of Jiangmen Kejunchi PT-2500D anti-poisoning microcapsule catalyst were added, and the mixture was stirred at room temperature for 1 hour to obtain the OBB component welding wire adhesive, which was then sealed and stored.

[0040] Comparative Example 4

[0041] 30 parts of vinyl silicone resin with a viscosity of 6000 mPa·s and a vinyl content of 1.2%, 40 parts of vinyl silicone oil with a viscosity of 7000 mPa·s and a vinyl content of 0.15%, 10 parts of octavinyldimethylsiloxycage polysilsesquioxane, 5 parts of heptaisobutyltrisilyl alcohol cage polysilsesquioxane, 2 parts of methacryloyloxypropylcyclotetrasiloxane, and 2 parts of acryloyloxypropylcage polysilsesquioxane were added to a reaction vessel and stirred. The temperature was set to 80℃ and stirred for 3 hours. Then, the mixture was allowed to cool naturally to room temperature. 10 parts of Evonik R972 thixotropic agent were added and the mixture was stirred at room temperature for another 1 hour. 5 parts of 6.0 mmoles / g hydrogen-containing silicone oil and 1 part of Jiangmen Kejunchi PT-2500D anti-poisoning microcapsule catalyst were added and stirred at room temperature for another 1 hour to obtain the OBB component welding wire adhesive, which was then sealed and stored.

[0042] Comparative Example 5

[0043] 30 parts of vinyl silicone resin with a viscosity of 6000 mPa·s and a vinyl content of 1.2%, 40 parts of vinyl silicone oil with a viscosity of 7000 mPa·s and a vinyl content of 0.15%, 10 parts of octavinyldimethylsiloxycage polysilsesquioxane, 5 parts of heptaisobutyltrisilyl alcohol cage polysilsesquioxane, 2 parts of methacryloyloxypropylcyclotetrasiloxane, and 2 parts of acryloyloxypropylcage polysilsesquioxane were added to a reaction vessel and stirred. The temperature was set at 80℃ and stirred for 3 hours. Then, the mixture was allowed to cool naturally to room temperature. 10 parts of H30 thixotropic agent were added, and stirring was continued at room temperature for 1 hour. 5 parts of 6.0 mmoles / g hydrogen-containing silicone oil, 1 part of Heraeus Pt=5000ppm catalyst, and 0.5 parts of alkynyl alcohol inhibitor were added, and the mixture was stirred at room temperature for 1 hour to obtain the OBB component welding wire adhesive, which was then sealed and stored.

[0044] The performance of a photovoltaic OBB technology encapsulant of the present invention was tested through the following experiments, and the results are shown in Table 1.

[0045] Table 1. Performance Indicators of Examples and Comparative Examples

[0046]

[0047]

[0048] The results above show that the welding wire adhesive for photovoltaic OBB modules of the present invention has excellent adhesion to welding ribbons. In Comparative Examples 1 and 3, the adhesion strength is lower when octavinyldimethylsiloxycage polysilsesquioxane or heptaisobutyltrisilyl alcoholcage polysilsesquioxane is not added, and the strength is even lower after adding flux. Secondly, the addition of heptaisobutyltrisilyl alcoholcage polysilsesquioxane has a good effect on viscosity stability. Meanwhile, the transparency of Comparative Examples 2 and 3 decreases when other silane coupling agents are added. In Comparative Example 4, different thixotropic agents are mainly selected, resulting in significant differences in transparency. In Comparative Example 5, it is found that the use of an anti-poisoning capsule structure catalyst significantly improves the side effects of flux on the catalyst, meeting the welding ribbon adhesion performance requirements for photovoltaic OBB technology.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A soldering paste for a photovoltaic OBB module, characterized by, According to the weight parts, the following components are included: 20-50 parts of vinyl silicone resin, 20-50 parts of vinyl silicone oil, 10-20 parts of octavinyl dimethyl siloxy cage polysilsesquioxane, 1-10 parts of heptaisobutyl trisilanol cage polysilsesquioxane, 0.5-3 parts of methacryloyloxypropyl cyclotetrasiloxane, 0.5-3 parts of acryloyloxypropyl cage polysilsesquioxane, 5-20 parts of thixotropic agent, 1-10 parts of hydrogen-containing silicone oil, 0.05-2 parts of anti-poisoning microcapsule catalyst, and the thixotropic agent is Wacker H30.

2. The soldering paste for a photovoltaic OBB module according to claim 1, wherein The vinyl silicone resin is an MQ silicone resin containing vinyl groups, with a vinyl mass content of 1-2% and a viscosity of 4000-8000 mpa.s.

3. The soldering paste for a photovoltaic OBB module according to claim 1, wherein The vinyl silicone oil is vinyl bis-terminated silicone oil, with a viscosity of 5000-10000 mpa.s and a vinyl mass content of 0.15-0.17%.

4. The soldering paste for a photovoltaic OBB module according to claim 3, wherein The viscosity of the vinyl silicone oil is 5000-6000 mpa.s.

5. The soldering paste for a photovoltaic OBB module according to claim 1, wherein The structure of the octavinyl dimethyl siloxy cage polysilsesquioxane is: 。 6. The soldering paste for a photovoltaic OBB module according to claim 1, wherein The structure of the heptaisobutyl trisilanol cage polysilsesquioxane is: 。 7. The soldering paste for a photovoltaic OBB module according to claim 1, wherein The viscosity of the methacryloyloxypropyl cyclotetrasiloxane is 100-300 mpa.s, and the structure is: 。 8. The soldering paste for a photovoltaic OBB module according to claim 1, wherein the soldering paste is characterized by The structure of the acryloyloxypropyl cage polysilsesquioxane is: The hydrogen-containing silicone oil is a silicone oil with H-terminated and pendant H functional groups, with a hydrogen content of 5.0-10.0 mmoles / g; and the anti-poisoning microcapsule catalyst is a microcapsule platinum catalyst.

9. A method for preparing a soldering paste for a solder wire for a photovoltaic module according to any one of claims 1 to 8, characterized by, The following steps are included: The following components are added to a reaction vessel and stirred: 20-50 parts of vinyl silicone resin, 20-50 parts of vinyl silicone oil, 10-20 parts of octavinyl dimethyl siloxy cage polysilsesquioxane, 1-10 parts of heptaisobutyl trisilanol cage polysilsesquioxane, 0.5-3 parts of methacryloyloxypropyl cyclotetrasiloxane, 0.5-3 parts of acryloyloxypropyl cage polysilsesquioxane, and the temperature is set to 80℃ and stirred for 3h, then naturally cooled to room temperature. After adding 5-20 parts of thixotropic agent, the room temperature continues to be stirred for 1h. Then 1-10 parts of hydrogen-containing silicone oil and 0.05-2 parts of anti-poisoning microcapsule catalyst are added, and stirred at room temperature for 1h to obtain the soldering adhesive for photovoltaic 0BB modules.

10. The use of the soldering adhesive for photovoltaic 0BB modules according to any one of claims 1-8 in the field of photovoltaic 0BB modules.

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