Low-temperature pre-coating colorant composition and preparation method, low-temperature colored pre-coating welding strip and preparation method

Abstract

The present invention provides a low-temperature pre-coating colorant composition, which includes, by mass fraction, 15-20% film former, 3.5-5% active agent, 1.2-2.9% surfactant, 3-6% dye, 15-20% cosolvent, 0.5-2% corrosion inhibitor, and the balance is solvent, wherein the film former includes hydrogenated rosin. The present invention also provides a method for preparing a low-temperature pre-coating colorant, wherein the film former is added to the cosolvent to obtain a first solution; the dye is added to the first solution to obtain a second solution; the active agent, the surfactant, and the corrosion inhibitor are added to the solvent to obtain a third solution; the third solution is added to the second solution to obtain a low-temperature pre-coating colorant. The present invention also provides a low-temperature colored pre-coated welding strip and a preparation method thereof. The low-temperature pre-coating colorant in the embodiment of the present invention can be applied to low-temperature or ultra-low-temperature photovoltaic welding strips to meet the production requirements of black 0BB components.

Description

Technical Field

[0001] The present invention belongs to the technical field of photovoltaic welding strips, and in particular relates to a low-temperature pre-coating colorant composition and a preparation method thereof, a low-temperature colored pre-coating welding strip and a preparation method thereof. Background Art

[0002] As the demand for cost reduction in the photovoltaic industry intensifies, reducing silver paste is an important means of reducing battery costs, and the iconic product is the 0BB type battery. This type of battery adopts a busbar-free or ultra-fine busbar design, eliminates or reduces the pad area, and greatly reduces the amount of silver paste used, thereby achieving material cost reduction. However, it also brings problems. For example, too fine silver paste grid lines cannot withstand high welding temperatures, and are prone to problems such as broken grids and cold solder joints. The welding temperature needs to be greatly reduced to avoid this. Therefore, low-temperature or ultra-low-temperature solder strips for low-temperature welding are derived, which are suitable for welding conditions where the liquidus temperature of the solder is below 150°C and the welding temperature is below 170°C.

[0003] Due to the significant changes in welding conditions, the existing room temperature pre-coating dyeing materials cannot be used in low temperature welding environments, and conventional black pre-coating solder strips cannot be used on black 0BB components. Therefore, for 0BB type black components, it is necessary to develop matching low temperature pre-coating colorants to match the requirements of low temperature welding processes. Summary of the invention

[0004] In order to solve at least one technical problem in the prior art, a low-temperature pre-coating colorant composition and a preparation method, a low-temperature colored pre-coated solder strip and a preparation method are provided, and the low-temperature colored pre-coated solder strip meets the use requirements. In order to achieve the above technical objectives, the technical solution adopted in the embodiment of the present invention is: In a first aspect, an embodiment of the present invention provides a low-temperature pre-coating colorant composition, which comprises the following components by mass fraction: The film-forming agent comprises 15-20%, an activating agent 3.5-5%, a surfactant 1.2-2.9%, a dye 3-6%, a cosolvent 15-20%, a corrosion inhibitor 0.5-2%, and the balance is a solvent. The film-forming agent comprises hydrogenated rosin.

[0005] Furthermore, the film-forming agent also includes a tackifying phase, a reinforcing phase, and a slip agent; The tackifying phase includes terephthalate tackifying resin; and / or, the reinforcing phase includes thermoplastic acrylic resin; and / or, the slip agent includes silicone slip agent; The softening point of the hydrogenated rosin is 120-125°C; and / or the softening point of the tackifying phase is 100-110°C; and / or the softening point of the reinforcing phase is 125-135°C; In the film-forming agent, the ratio of the hydrogenated rosin, the tackifying phase, the reinforcing phase, and the slip agent is (5-7): (1-3): (3-5): (0.5-1.5).

[0006] Further, the active agent includes an organic acid; The active agent includes at least one of glutaric acid, methylsuccinic acid, and maleic acid; The active agent includes glutaric acid, methylsuccinic acid, and maleic acid; In the active agent, the ratio of the glutaric acid, the methylsuccinic acid and the maleic acid to the low-temperature pre-coating colorant composition is (0.5-1%): (1-1.5%): (2-2.5%).

[0007] Further, the surfactant includes at least one of cyclohexylamine adipate, acetylenic glycol, and fatty alcohol alkoxylate; The surfactant includes cyclohexylamine adipate, acetylenic glycol, and fatty alcohol alkoxy compounds; Among the surfactants, the proportions of the cyclohexylamine adipate, the acetylene glycol, and the fatty alcohol alkoxy compound in the low-temperature pre-coating colorant composition are (0.2-0.4%): (0.6-1.5%): (0.4-1.0%).

[0008] Further, the dye comprises an alcohol-soluble dye; The dyes include organic dyes and / or metal complex dyes.

[0009] Further, the cosolvent includes ethers; The cosolvent comprises at least one of diethylene glycol butyl ether, diethylene glycol dibutyl ether, and diethylene glycol mono-2-ethylhexyl ether; The solvent includes alcohols and esters; The solvent includes at least one of ethanol, isopropanol and ethyl acetate.

[0010] Further, the corrosion inhibitor includes imidazoles; The corrosion inhibitor comprises at least one of benzotriazole, 2-phenyl-4-5-methylimidazole and 2-pentylbenzimidazole.

[0011] In a second aspect, an embodiment of the present invention further provides a method for preparing a low-temperature pre-coating colorant, using the above-mentioned low-temperature pre-coating colorant composition, comprising the following steps: Step S1, adding each component of the film-forming agent to the co-solvent in sequence, stirring sufficiently to completely dissolve the solid components, and obtaining a first solution; Step S2, adding dye to the first solution, and grinding using a grinder for at least 2 hours to obtain a second solution; Step S3, adding the active agent, the surfactant, and the corrosion inhibitor to the solvent in sequence to obtain a third solution; Step S4, adding the third solution into the second solution, keeping the grinder running during the adding process, and continuing grinding for at least 1 hour after the two solutions are basically mixed to obtain the low-temperature pre-coating colorant.

[0012] In a third aspect, an embodiment of the present invention further provides a low-temperature colored pre-coated solder strip, comprising a conductive substrate and a low-temperature pre-coating colorant coated on the conductive substrate, wherein the low-temperature pre-coating colorant is prepared by the above-mentioned method for preparing the low-temperature pre-coating colorant; The conductive substrate comprises a low-temperature tin-coated solder strip with copper, aluminum or a copper-aluminum composite material as a base and a low-temperature solder as a wrapping layer.

[0013] In a fourth aspect, an embodiment of the present invention further provides a method for preparing a low-temperature colored pre-coated solder strip, comprising the following steps: Step a, coating a low-temperature pre-coating colorant, uniformly coating the low-temperature pre-coating colorant on the surface of the conductive substrate to form a low-temperature pre-coating colorant wet film, wherein the thickness of the low-temperature pre-coating colorant wet film is 5 to 10 μm; Step b, drying, preheating and drying the low-temperature pre-coated colorant wet film on the surface of the conductive substrate in step a through a drying tunnel to form a low-temperature pre-coated colorant layer, setting the preheating section temperature of the drying tunnel to 70-80° C., the constant temperature section temperature to 100-120° C., and the drying time to 2-5 min to obtain a low-temperature colored pre-coated welding strip; The thickness of the low-temperature pre-coating colorant layer is 2 to 5 μm.

[0014] The technical solution provided by the embodiment of the present invention has the following beneficial effects: The low-temperature pre-coated colorant in the embodiment of the present invention can be applicable to low-temperature or ultra-low-temperature photovoltaic welding strips, and low-temperature and ultra-low-temperature welding scenarios where the welding temperature is lower than 170°C or the lamination temperature is used for welding. It is used in conjunction with ultra-low-temperature welding strips with a solder liquidus temperature point lower than 150°C to meet the production needs of black 0BB components, solve the problem that room-temperature black pre-coated welding strips and colored pre-coated welding strips cannot be used in 0BB low-temperature welding processes, and enable low-temperature welding components represented by 0BB batteries to achieve consistency in appearance between the welding strip and the component, making them truly all-black components, greatly improving the appearance of black components and promoting the development of 0BB components for civil power stations. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0016] In addition, it should be understood that after reading the contents disclosed in the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the protection scope defined by the present invention.

[0017] The embodiment of the present invention provides a low-temperature pre-coating colorant composition, which comprises the following components by mass fraction: The film-forming agent comprises 15-20%, an activating agent 3.5-5%, a surfactant 1.2-2.9%, a dye 3-6%, a cosolvent 15-20%, a corrosion inhibitor 0.5-2%, and the balance is a solvent. The film-forming agent comprises hydrogenated rosin.

[0018] Furthermore, the film-forming agent also includes a tackifying phase, a reinforcing phase, and a slip agent; The tackifying phase includes terephthalate tackifying resin; and / or, the reinforcing phase includes thermoplastic acrylic resin; and / or, the slip agent includes silicone slip agent; The softening point of the hydrogenated rosin is 120-125°C; and / or the softening point of the tackifying phase is 100-110°C; and / or the softening point of the reinforcing phase is 125-135°C; In the film-forming agent, the ratio of the hydrogenated rosin, the tackifying phase, the reinforcing phase, and the slip agent is (5-7): (1-3): (3-5): (0.5-1.5).

[0019] It should be noted that there are many types of hydrogenated rosin. If the softening point of the hydrogenated rosin is too low, the low-temperature pre-coated colorant will be completely melted during the lamination process. If the softening point of the hydrogenated rosin is too high, the low-temperature pre-coated colorant will not be able to melt. Both situations will make the solder strip unusable. Therefore, the present application uses the hydrogenated rosin with a softening point of 120°C to 125°C to ensure the normal use of the solder strip. More specifically, in the lamination process, the temperature of the first temperature zone is 100°C to 115°C, and the temperature of the second temperature zone is about 140°C. When in the first temperature zone, if the pre-coated coloring layer on the surface of the solder strip melts, the film layer will spread and detach from the solder strip as the packaging film flows, thereby causing contamination of other parts. Therefore, the present application uses hydrogenated rosin with a softening point of 120°C to 125°C as the main carrier in the pre-coated coloring layer, which can ensure that the pre-coated coloring layer and the film layer on the surface of the solder strip will not flow with the packaging film in the first temperature zone. When entering the second temperature zone, the fluidity of the packaging film decreases, and the pre-coated color layer on the surface of the solder strip begins to melt, which can play a role in flux and will not spread, but can stably adhere to the surface of the solder strip.

[0020] The low-temperature pre-coating colorant composition described in the present application can be used for 0BB type ultra-low temperature solder strips. On the one hand, the diameter of this type of solder strip is relatively thin, usually less than 0.2 mm, so the ability of the surface to adhere to the pre-coating coloring layer is weaker than that of the solder strip of conventional size, and the thickness of the adhesion layer is relatively low, so it is necessary to increase a certain viscosity to maintain the smoothness and film thickness of the pre-coating coloring layer. By adding a tackifying phase, the deposition of the low-temperature pre-coating colorant on the surface of the solder strip during the coating process can be improved, and the bonding strength between the pre-coating coloring layer film and the metal substrate of the solder strip can be improved. Since the softening point of the terpenoid tackifying resin is 100-110°C, which is the lowest among the film-forming agents, it will be concentrated on the metal surface of the solder strip when cooled, which has the effect of increasing adhesion.

[0021] On the other hand, the strength and wear resistance of the low-temperature pre-coated color layer of the welding ribbon need to meet the use standards, and it is necessary to avoid the film layers of the welding ribbon from sticking to each other when winding. The present application can ensure that the film layer obtains good surface hardness after curing by adding a reinforcing phase resin, and reduce the surface viscosity of the pre-coated color layer after curing, and avoid the film layers from sticking to each other when the welding ribbon is wound, which is beneficial for storage. The reinforcing phase described in the present application is a thermoplastic acrylic resin, which has a softening point of 125 to 135°C, and a softening temperature slightly higher than that of hydrogenated rosin. Therefore, during the cooling process, a solid film is first formed on the surface of the film layer. After being completely dried, the thermoplastic acrylic resin will be enriched on the surface of the film layer, which can effectively increase the hardness of the surface of the pre-coated color layer and reduce the surface viscosity. In combination with the lubricant, a smooth and flat pre-coated color layer can be obtained.

[0022] Furthermore, in the film-forming agent, the ratio of the hydrogenated rosin, the tackifying phase, the reinforcing phase and the slip agent is 6:2:4:1.

[0023] Further, the active agent includes an organic acid; The active agent includes at least one of glutaric acid, methylsuccinic acid and maleic acid.

[0024] The active agent includes glutaric acid, methylsuccinic acid, and maleic acid; In the active agent, the ratio of the glutaric acid, the methylsuccinic acid and the maleic acid to the low-temperature pre-coating colorant composition is (0.5-1%): (1-1.5%): (2-2.5%).

[0025] Among the activators, the melting point of glutaric acid is 100°C, the melting point of methylsuccinic acid is 115°C, and the melting point of maleic acid is 135°C. The activator adopts a compounded organic acid, which is stable and non-volatile at room temperature. The active range is 100°C to 140°C, which meets the actual welding conditions of low-temperature solder strips and ensures the soldering effect during the entire heating process.

[0026] Further, the surfactant includes at least one of cyclohexylamine adipate, acetylenic glycol, and fatty alcohol alkoxylate; The surfactant includes cyclohexylamine adipate, acetylenic glycol, and fatty alcohol alkoxy compounds; Among the surfactants, the proportions of the cyclohexylamine adipate, the acetylene glycol, and the fatty alcohol alkoxy compound in the low-temperature pre-coating colorant composition are (0.2-0.4%): (0.6-1.5%): (0.4-1.0%).

[0027] Further, the dye comprises an alcohol-soluble dye; The dyes include organic dyes and / or metal complex dyes.

[0028] Alcohol-soluble dyes can increase the solubility of dyes. Among them, black dyes can be selected from aniline black, or copper complex black, iron-manganese complex dyes, etc. with a mesh size of 3000 or more.

[0029] Further, the cosolvent includes ethers; The cosolvent comprises at least one of diethylene glycol butyl ether, diethylene glycol dibutyl ether, and diethylene glycol mono-2-ethylhexyl ether; The solvent includes alcohols and esters; The solvent includes at least one of ethanol, isopropanol and ethyl acetate.

[0030] Further, the corrosion inhibitor includes imidazoles; The corrosion inhibitor comprises at least one of benzotriazole, 2-phenyl-4-5-methylimidazole and 2-pentylbenzimidazole.

[0031] The corrosion inhibitor can slow down the reaction between the activator and tin, thereby preventing the solder strip from deteriorating during long-term storage.

[0032] In a second aspect, an embodiment of the present invention further provides a method for preparing a low-temperature pre-coating colorant, comprising the following steps: Step S1, adding each component of the film-forming agent to the co-solvent in sequence, stirring sufficiently to completely dissolve the solid components, and obtaining a first solution; Step S2, adding a dye to the first solution, and grinding using a grinder for at least 2 hours to obtain a second solution; this step allows the dye and the film-forming agent to be completely and fully mixed.

[0033] Step S3, adding the active agent, the surfactant, and the corrosion inhibitor to the solvent in sequence to obtain a third solution; Step S4, adding the third solution into the second solution, keeping the grinder running during the adding process, and continuing grinding for at least 1 hour after the two solutions are basically mixed to obtain the low-temperature pre-coating colorant.

[0034] Furthermore, the solvent can be divided into two parts and added separately, which can increase the mixing effect of each component in the solvent. In step S3, the active agent, the surfactant, and the corrosion inhibitor are added to part of the solvent in sequence, and the dissolution of the active agent, the surfactant, and the corrosion inhibitor is ensured; in step S4, after the third solution is added to the second solution, the remaining solvent is continued to be added to ensure sufficient mixing of the components.

[0035] Furthermore, in step S1 to step S4, the grinding is performed in a closed environment to reduce the volatilization of the solvent. For example, a sealing cover can be added to the container during grinding.

[0036] In a third aspect, an embodiment of the present invention further provides a low-temperature colored pre-coated solder strip, comprising a conductive substrate and a low-temperature pre-coating colorant coated on the conductive substrate, wherein the low-temperature pre-coating colorant is prepared by the above-mentioned method for preparing the low-temperature pre-coating colorant; The conductive substrate comprises a low-temperature tin-coated solder strip with copper, aluminum or a copper-aluminum composite material as a base and a low-temperature solder as a wrapping layer.

[0037] In a fourth aspect, an embodiment of the present invention further provides a method for preparing a low-temperature colored pre-coated solder strip, comprising the following steps: Step a, coating a low-temperature pre-coating colorant, uniformly coating the low-temperature pre-coating colorant on the surface of the conductive substrate to form a low-temperature pre-coating colorant wet film, wherein the thickness of the low-temperature pre-coating colorant wet film is 5 to 10 μm; Step b, drying, preheating and drying the low-temperature pre-coated colorant wet film on the surface of the conductive substrate in step a through a drying tunnel to form a low-temperature pre-coated colorant layer, setting the preheating section temperature of the drying tunnel to 70-80° C., the constant temperature section temperature to 100-120° C., and the drying time to 2-5 min to obtain a low-temperature colored pre-coated welding strip; The thickness of the low-temperature pre-coating colorant layer is 2 to 5 μm.

[0038] In the following specific examples and comparative examples, the operations involved, if the conditions are not specified, are all carried out under conventional conditions or under conditions recommended by the manufacturer. All raw materials, if the manufacturers and specifications are not specified, are conventional products that can be obtained from the market.

[0039] Example 1 A low-temperature pre-coating colorant composition comprises the following components: Film former 15g, active agent 5g, surfactant 2.9g, manganese iron black 6g, diethylene glycol butyl ether 15g, benzotriazole 0.5g, anhydrous ethanol 54.1g; The film-forming agent includes 6.9 g of hydrogenated rosin, 2.3 g of terephthalate tackifying resin, 4.6 g of acrylic resin, and 1.2 g of lubricant; The active agent includes 1g of glutaric acid, 1.5g of methylsuccinic acid, and 2.5g of maleic acid; The surfactant comprises 0.4 g of cyclohexylamine adipate, 1.5 g of acetylene glycol and 1 g of fatty alcohol alkoxy compound.

[0040] Example 2 A low-temperature pre-coating colorant composition comprises the following components: Film former 17g, active agent 4.1g, surfactant 2g, copper complex black 4.5g, diethylene glycol butyl ether 17g, benzotriazole 1g, anhydrous ethanol 54.2g; The film-forming agent includes 7.9 g of hydrogenated rosin, 2.6 g of terephthalate tackifying resin, 5.2 g of acrylic resin, and 1.3 g of lubricant; The active agent includes 0.7g glutaric acid, 1.2g methylsuccinic acid, and 2.2g maleic acid; The surfactant comprises 0.3 g of cyclohexylamine adipate, 1 g of acetylene glycol and 0.7 g of fatty alcohol alkoxy compound.

[0041] Example 3 A low-temperature pre-coating colorant composition comprises the following components: Film former 18.5g, active agent 3.5g, surfactant 1.2g, carbon black dye 3g, diethylene glycol butyl ether 20g, benzotriazole 2g, anhydrous ethanol 51.8g; The film-forming agent includes 9.2 g of hydrogenated rosin, 3.1 g of terephthalate tackifying resin, 6.2 g of acrylic resin, and 1.5 g of lubricant; The active agent includes 0.5g glutaric acid, 1g methylsuccinic acid, and 2g maleic acid; The surfactant is 0.2 g of cyclohexylamine adipate, 0.6 g of acetylene glycol, and 0.4 g of fatty alcohol alkoxy compound.

[0042] Example 4 A method for preparing a low-temperature pre-coating colorant, using the formula of the low-temperature pre-coating colorant composition in Example 1, comprises the following steps: Step S1, weighing 6.9 g of hydrogenated rosin, 2.3 g of terephthalate tackifying resin, 4.6 g of acrylic resin, and 1.2 g of lubricant in sequence, adding them to 15 g of diethylene glycol butyl ether, stirring them sufficiently to completely dissolve the solid components, and obtaining a first solution; Step S2, adding 6 g of manganese iron black dye to the first solution, and grinding it with a grinder for 2 hours to obtain a second solution; Step S3, weigh 1 g of glutaric acid, 1.5 g of methylsuccinic acid, and 2.5 g of maleic acid in sequence, add them to 30 g of anhydrous ethanol, stir thoroughly to dissolve the solids, then add 0.4 g of cyclohexylamine adipate, 1.5 g of acetylene glycol, 1 g of fatty alcohol alkoxy compound, and 0.5 g of benzotriazole in sequence, stir for 20 min, and obtain a third solution; Step S4, slowly add the third solution to the second solution and keep the grinder running. After the two solutions are basically mixed, add the remaining 24.1g of anhydrous ethanol and continue grinding in a closed state for 1 hour to obtain a low-temperature pre-coating colorant.

[0043] Example 5 A method for preparing a low-temperature pre-coating colorant, using the formula of the low-temperature pre-coating colorant composition in Example 2, comprises the following steps: Step S1, weighing 7.9 g of hydrogenated rosin, 2.6 g of terephthalate tackifying resin, 5.2 g of acrylic resin, and 1.3 g of lubricant in sequence, adding them to 17 g of diethylene glycol butyl ether, stirring them sufficiently to completely dissolve the solid components, and obtaining a first solution; Step S2, adding 4.5 g of copper complex black to the first solution, and grinding with a grinder for 2 h to obtain a second solution; Step S3, weigh 0.7 g of glutaric acid, 1.2 g of methylsuccinic acid, and 2.2 g of maleic acid in sequence, add them to 30 g of anhydrous ethanol by mass fraction, stir well to dissolve the solids, then add 0.3 g of cyclohexylamine adipate, 1 g of acetylene glycol, 0.7 g of fatty alcohol alkoxy compound, and 1 g of benzotriazole in sequence, stir for 20 min, and obtain a third solution; Step S4, adding the third solution into the second solution and keeping the grinder running continuously, after the two solutions are basically mixed, adding the remaining 24.2g of anhydrous ethanol, and continuing grinding in a closed state for 1 hour to obtain a low-temperature pre-coating colorant.

[0044] Example 6 A method for preparing a low-temperature pre-coating colorant, using the formula of the low-temperature pre-coating colorant composition in Example 3, comprises the following steps: Step S1, weighing 9.2 g of hydrogenated rosin, 3.1 g of terephthalate tackifying resin, 6.2 g of acrylic resin, and 1.5 g of lubricant in sequence, adding them to 20 g of diethylene glycol butyl ether, stirring them sufficiently to completely dissolve the solid components, and obtaining a first solution; Step S2, adding 3 g of carbon black dye to the first solution, and grinding for 2 h using a grinder to obtain a second solution; Step S3, weigh 0.5 g of glutaric acid, 1 g of methylsuccinic acid, and 2 g of maleic acid in sequence, add them to 25 g of anhydrous ethanol, stir thoroughly to dissolve the solids, then add 0.2 g of cyclohexylamine adipate, 0.6 g of acetylene glycol, 0.4 g of fatty alcohol alkoxy compound, and 2 g of benzotriazole, stir for 20 min, and obtain a third solution; Step S4, adding the third solution into the second solution and keeping the grinder running continuously, after the two solutions are basically mixed, adding the remaining 26.8g of anhydrous ethanol, and continuously grinding in a closed state for 1 hour to obtain a low-temperature pre-coating colorant.

[0045] Example 7 A method for preparing a low-temperature colored pre-coated solder strip comprises the following steps: Step a, coating a low-temperature pre-coating colorant, uniformly coating the low-temperature pre-coating colorant prepared in Example 4 on the surface of the conductive substrate to form a low-temperature pre-coating colorant wet film, wherein the thickness of the low-temperature pre-coating colorant wet film is 6 μm; Step b, drying, preheating and drying the low-temperature pre-coating colorant wet film on the surface of the conductive substrate in step a through a drying tunnel to form a low-temperature pre-coating colorant layer, setting the preheating section temperature of the drying tunnel to 75°C, the constant temperature section temperature to 110°C, and the drying time to 3 minutes to obtain a low-temperature colored pre-coated solder strip, the thickness of the low-temperature pre-coating colorant layer is 2.5 μm.

[0046] Example 8 A method for preparing a low-temperature colored pre-coated solder strip comprises the following steps: Step a, coating a low-temperature pre-coating colorant, uniformly coating the low-temperature pre-coating colorant prepared in Example 5 on the surface of the conductive substrate to form a low-temperature pre-coating colorant wet film, wherein the thickness of the low-temperature pre-coating colorant wet film is 7 μm; Step b, drying, preheating and drying the low-temperature pre-coating colorant wet film on the surface of the conductive substrate in step a through a drying tunnel to form a low-temperature pre-coating colorant layer, setting the preheating section temperature of the drying tunnel to 75°C, the constant temperature section temperature to 110°C, and the drying time to 3 min to obtain a low-temperature colored pre-coated solder strip, the thickness of the low-temperature pre-coating colorant layer is 3.5 μm.

[0047] Example 9 A method for preparing a low-temperature colored pre-coated solder strip comprises the following steps: Step a, coating a low-temperature pre-coating colorant, uniformly coating the low-temperature pre-coating colorant prepared in Example 6 on the surface of the conductive substrate to form a low-temperature pre-coating colorant wet film, wherein the thickness of the low-temperature pre-coating colorant wet film is 9.5 μm; Step b, drying, preheating and drying the low-temperature pre-coating colorant wet film on the surface of the conductive substrate in step a through a drying tunnel to form a low-temperature pre-coating colorant layer, setting the preheating section temperature of the drying tunnel to 75°C, the constant temperature section temperature to 110°C, and the drying time to 4 minutes to obtain a low-temperature colored pre-coated solder strip, the thickness of the low-temperature pre-coating colorant layer is 4.5μm.

[0048] Comparative Example 1 A method for preparing a pre-coating colorant comprises the following steps: Step S1, weighing 3.5 g of hydrogenated rosin, 1.1 g of terephthalate tackifying resin, 2.3 g of acrylic resin, and 0.5 g of lubricant in sequence, adding them to 15 g of diethylene glycol butyl ether, stirring them sufficiently to completely dissolve the solid components, and obtaining a first solution; Step S2, adding 6 g of manganese iron black dye to the first solution, and grinding it with a grinder for 2 hours to obtain a second solution; Step S3, weigh 1 g of glutaric acid, 1.5 g of methylsuccinic acid, and 2.5 g of maleic acid in sequence, add them to 30 g of anhydrous ethanol, stir thoroughly to dissolve the solids, then add 0.4 g of cyclohexylamine adipate, 1.5 g of acetylene glycol, 1 g of fatty alcohol alkoxy compound, and 0.5 g of benzotriazole in sequence, stir for 20 min, and obtain a third solution; Step S4, slowly add the third solution to the second solution and keep the grinder running. After the two solutions are basically mixed, add the remaining 24.1g of anhydrous ethanol and continue grinding in a closed state for 1 hour to obtain a pre-coated colorant.

[0049] Comparative Example 2 A method for preparing a pre-coating colorant comprises the following steps: Step S1, weighing 18 g of hydrogenated rosin, 6 g of terephthalate tackifying resin, 12 g of acrylic resin, and 3 g of lubricant in sequence, and adding them to 20 g of diethylene glycol butyl ether, stirring them sufficiently to completely dissolve the solid components, and obtaining a first solution; Step S2, adding 3 g of carbon black dye to the first solution, and grinding for 2 h using a grinder to obtain a second solution; Step S3, weigh 0.5 g of glutaric acid, 1 g of methylsuccinic acid, and 2 g of maleic acid in sequence, add them to 25 g of anhydrous ethanol, stir thoroughly to dissolve the solids, then add 0.2 g of cyclohexylamine adipate, 0.6 g of acetylene glycol, 0.4 g of fatty alcohol alkoxy compound, and 2 g of benzotriazole, stir for 20 min, and obtain a third solution; Step S4, adding the third solution into the second solution and keeping the grinder running continuously, after the two solutions are basically mixed, adding the remaining 26.8g of anhydrous ethanol, and continuously grinding in a closed state for 1 hour to obtain a pre-coated colorant.

[0050] Comparative Example 3 A method for preparing a pre-coating colorant comprises the following steps: Step S1, weighing 9.2 g of hydrogenated rosin, 3.1 g of terephthalate tackifying resin, 6.2 g of acrylic resin, and 1.5 g of lubricant in sequence, adding them to 20 g of diethylene glycol butyl ether, stirring them sufficiently to completely dissolve the solid components, and obtaining a first solution; Step S2, adding 3 g of carbon black dye to the first solution, and grinding for 2 h using a grinder to obtain a second solution; Step S3, weigh 0.2 g of glutaric acid, 0.5 g of methylsuccinic acid, and 1 g of maleic acid in sequence, add them to 25 g of anhydrous ethanol, stir thoroughly to dissolve the solids, then add 0.2 g of cyclohexylamine adipate, 0.6 g of acetylene glycol, 0.4 g of fatty alcohol alkoxy compound, and 2 g of benzotriazole, stir for 20 min, and obtain a third solution; Step S4, adding the third solution into the second solution and keeping the grinder running continuously, after the two solutions are basically mixed, adding the remaining 26.8g of anhydrous ethanol, and continuously grinding in a closed state for 1 hour to obtain a pre-coated colorant.

[0051] Comparative Example 4 A method for preparing a pre-coating colorant comprises the following steps: Step S1, weighing 6.9 g of hydrogenated rosin, 2.3 g of terephthalate tackifying resin, 4.6 g of acrylic resin, and 1.2 g of lubricant in sequence, adding them to 15 g of diethylene glycol butyl ether, stirring them sufficiently to completely dissolve the solid components, and obtaining a first solution; Step S2, adding 6 g of manganese iron black dye to the first solution, and grinding it with a grinder for 2 hours to obtain a second solution; Step S3, weigh 2 g of glutaric acid, 3 g of methylsuccinic acid, and 5 g of maleic acid in sequence, add them to 30 g of anhydrous ethanol, stir thoroughly to dissolve the solids, then add 0.4 g of cyclohexylamine adipate, 1.5 g of acetylene glycol, 1 g of fatty alcohol alkoxy compound, and 0.5 g of benzotriazole in sequence, stir for 20 min, and obtain a third solution; Step S4, slowly add the third solution to the second solution and keep the grinder running. After the two solutions are basically mixed, add the remaining 24.1g of anhydrous ethanol and continue grinding in a closed state for 1 hour to obtain a pre-coated colorant.

[0052] Comparative Example 5 A method for preparing a pre-coating colorant comprises the following steps: Step S1, weighing 6.9 g of hydrogenated rosin, 2.3 g of terephthalate tackifying resin, 4.6 g of acrylic resin, and 1.2 g of lubricant in sequence, adding them to 15 g of diethylene glycol butyl ether, stirring them sufficiently to completely dissolve the solid components, and obtaining a first solution; Step S2, adding 6 g of manganese iron black dye to the first solution, and grinding it with a grinder for 2 hours to obtain a second solution; Step S3, weigh 1 g of glutaric acid, 1.5 g of methylsuccinic acid, and 2.5 g of maleic acid in sequence, add them to 30 g of anhydrous ethanol, stir thoroughly to dissolve the solids, then add 0.4 g of cyclohexylamine adipate, 1.5 g of acetylene glycol, 1 g of fatty alcohol alkoxy compound, and 0.2 g of benzotriazole in sequence, stir for 20 min, and obtain a third solution; Step S4, slowly add the third solution to the second solution and keep the grinder running. After the two solutions are basically mixed, add the remaining 24.1g of anhydrous ethanol and continue grinding in a closed state for 1 hour to obtain a pre-coated colorant.

[0053] Comparative Example 6 A method for preparing a pre-coated welding strip comprises the following steps: Step a, coating a pre-coating colorant, uniformly coating the pre-coating colorant prepared in Comparative Example 1 on the surface of the conductive substrate to form a pre-coating colorant wet film, the thickness of the pre-coating colorant wet film is 6 μm; Step b, drying, preheating and drying the pre-coated colorant wet film on the surface of the conductive substrate in step a through a drying tunnel to form a pre-coated colorant layer, setting the preheating section temperature of the drying tunnel to 75°C, the constant temperature section temperature to 110°C, and setting the drying time to 3 minutes.

[0054] Compared with Example 7, the overall proportion of the film-forming agent in Comparative Example 6 is too low, and the pre-coated colorant layer on the surface of the solder strip after drying is too thin to completely cover the metal base color of the conductive substrate, thereby being an unqualified product.

[0055] Comparative Example 7 A method for preparing a pre-coated welding strip comprises the following steps: Step a, coating a pre-coating colorant, uniformly coating the pre-coating colorant prepared in Comparative Example 2 on the surface of the conductive substrate to form a pre-coating colorant wet film, the thickness of the pre-coating colorant wet film is 9.5 μm; Step b, drying, preheating and drying the pre-coated colorant wet film on the surface of the conductive substrate in step a through a drying tunnel to form a pre-coated colorant layer, and setting the preheating section temperature of the drying tunnel to 75°C and the constant temperature section temperature to 110°C.

[0056] Compared with Example 9, the overall proportion of the film-forming agent in Comparative Example 7 is too high, the pre-coated color film layer on the surface of the solder strip after drying is too thick, the drying time requires longer, and the pre-coated color film layer on the surface of the solder strip is very sticky. After the solder strip is rolled up, there will be a back-sticking phenomenon, resulting in partial shedding of the pre-coated color film layer, which is not conducive to storage and is an unqualified product.

[0057] Comparative Example 8 A method for preparing a pre-coated welding strip comprises the following steps: Step a, coating a pre-coating colorant, uniformly coating the pre-coating colorant prepared in Comparative Example 3 on the surface of the conductive substrate to form a pre-coating colorant wet film, the thickness of the pre-coating colorant wet film is 9.5 μm; Step b, drying, preheating and drying the pre-coated colorant wet film on the surface of the conductive substrate in step a through a drying tunnel to form a pre-coated colorant layer, setting the preheating section temperature of the drying tunnel to 75°C, the constant temperature section temperature to 110°C, and the drying time to 4 min to obtain a pre-coated solder strip, the thickness of the pre-coated colorant layer is 4.5 μm.

[0058] Comparative Example 9 A method for preparing a pre-coated welding strip comprises the following steps: Step a, coating a pre-coating colorant, uniformly coating the pre-coating colorant prepared in Comparative Example 4 on the surface of the conductive substrate to form a pre-coating colorant wet film, the thickness of the pre-coating colorant wet film is 6 μm; Step b, drying, preheating and drying the pre-coated colorant wet film on the surface of the conductive substrate in step a through a drying tunnel to form a pre-coated colorant layer, setting the preheating section temperature of the drying tunnel to 75°C, the constant temperature section temperature to 110°C, and the drying time to 3 min to obtain a pre-coated solder strip, the thickness of the pre-coated colorant layer is 2.5 μm.

[0059] Comparative Example 10 A method for preparing a pre-coated welding strip comprises the following steps: Step a, coating a pre-coating colorant, uniformly coating the pre-coating colorant prepared in Comparative Example 5 on the surface of the conductive substrate to form a pre-coating colorant wet film, the thickness of the pre-coating colorant wet film is 6 μm; Step b, drying, preheating and drying the pre-coated colorant wet film on the surface of the conductive substrate in step a through a drying tunnel to form a pre-coated colorant layer, setting the preheating section temperature of the drying tunnel to 75°C, the constant temperature section temperature to 110°C, and the drying time to 3 minutes to obtain a pre-coated solder strip, the thickness of the pre-coated colorant layer is 2.5 μm.

[0060] Application Examples This application example is to laminate and weld the low-temperature colored pre-coated solder strips using the low-temperature pre-coated colorant in Examples 7-9, the pre-coated solder strips using the pre-coated colorant in Comparative Examples 6-10, and the ordinary solder strips without pre-coated flux respectively with 0BB solar cells through the film lamination welding process, and perform EL power-on test, DH1000 and TC200 related tests. Among them, the EL power-on test is performed on the solder strip according to the method provided in the "NB / T 11080-2023 Photovoltaic Module Electroluminescence (EL) Detection Technical Specification" standard, and the DH1000 and TC200 related tests are performed on the solder strip according to the "IEC61215-2 Module Test Standard" standard. The test results are as follows: In Comparative Example 6, the overall proportion of the film-forming agent in the pre-coating colorant is too low, and the pre-coating coloring film layer on the surface of the solder strip after drying is too thin to completely cover the metal base color of the solder strip, and is an unqualified product.

[0061] In Comparative Example 7, the overall proportion of the film-forming agent in the pre-coating colorant is too high, the pre-coating color film layer on the surface of the solder strip after drying is too thick, the drying time requires longer, and the pre-coating color film layer on the surface of the solder strip is very sticky. After the solder strip is rolled up, there will be a back-sticking phenomenon, resulting in partial shedding of the pre-coating color film layer, which is not conducive to storage and is an unqualified product.

[0062] In Comparative Example 8, the overall proportion of the active agent in the pre-coated colorant is too low, which leads to poor soldering effect of the corresponding pre-coated solder strip product and a high rate of false solder joints after welding.

[0063] In Comparative Example 9, the overall proportion of the active agent in the pre-coating colorant is too high, and in Comparative Example 10, the proportion of the corrosion inhibitor in the pre-coating colorant is too low, both of which cause the corresponding pre-coated solder strip products to have a lot of residue after welding and pitting corrosion after reliability testing.

[0064] In the low-temperature colored pre-coated solder strips prepared in Examples 7-9 of the present application, the low-temperature pre-coated colorant layer can maintain a complete black color and completely cover the metal base color of the low-temperature solder strip, thereby maintaining the consistency of the appearance of the battery cell assembly. The EL test also shows that the cold solder joint rate is low, and is also lower than that of ordinary solder strips that do not use pre-coated flux. At the same time, DH1000 and TC200 tests show that the appearance of the assembly remains unchanged and the power attenuation of the assembly is less than 2%. The low-temperature colored pre-coated solder strips in Examples 7-9 can pass the reliability test and meet the use requirements.

[0065] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A low-temperature pre-coating colorant composition, characterized in that: By mass fraction, it includes the following components: Film former 15-20%, active agent 3.5-5%, surfactant 1.2-2.9%, dye 3-6%, cosolvent 15-20%, corrosion inhibitor 0.5-2%, the balance is solvent; The film former includes hydrogenated rosin.

2. The low-temperature pre-coating colorant composition according to claim 1, characterized in that The film-forming agent also includes a tackifying phase, a reinforcing phase, and a slip agent; The tackifying phase includes terephthalate tackifying resin; and / or, the reinforcing phase includes thermoplastic acrylic resin; and / or, the slip agent includes silicone slip agent; The softening point of the hydrogenated rosin is 120-125°C; and / or the softening point of the tackifying phase is 100-110°C; and / or the softening point of the reinforcing phase is 125-135°C; In the film-forming agent, the ratio of the hydrogenated rosin, the tackifying phase, the reinforcing phase, and the slip agent is (5-7): (1-3): (3-5): (0.5-1.5).

3. The low-temperature pre-coating colorant composition according to claim 1, characterized in that The active agent includes an organic acid; The active agent includes at least one of glutaric acid, methylsuccinic acid, and maleic acid; The active agent includes glutaric acid, methylsuccinic acid, and maleic acid; In the active agent, the ratio of the glutaric acid, the methylsuccinic acid and the maleic acid to the low-temperature pre-coating colorant composition is (0.5-1%): (1-1.5%): (2-2.5%).

4. The low-temperature pre-coating colorant composition according to claim 1, characterized in that The surfactant comprises at least one of cyclohexylamine adipate, acetylenic glycol, and fatty alcohol alkoxylate; The surfactant includes cyclohexylamine adipate, acetylenic glycol, and fatty alcohol alkoxy compounds; Among the surfactants, the proportions of the cyclohexylamine adipate, the acetylene glycol, and the fatty alcohol alkoxy compound in the low-temperature pre-coating colorant composition are (0.2-0.4%): (0.6-1.5%): (0.4-1.0%).

5. The low-temperature pre-coating colorant composition according to claim 1, characterized in that The dye comprises an alcohol-soluble dye; The dyes include organic dyes and / or metal complex dyes.

6. The low-temperature pre-coating colorant composition according to claim 1, characterized in that The cosolvent includes ethers; The cosolvent comprises at least one of diethylene glycol butyl ether, diethylene glycol dibutyl ether, and diethylene glycol mono-2-ethylhexyl ether; The solvent includes alcohols and esters; The solvent includes at least one of ethanol, isopropanol and ethyl acetate.

7. The low-temperature pre-coating colorant composition according to claim 1, characterized in that The corrosion inhibitor includes imidazoles; The corrosion inhibitor comprises at least one of benzotriazole, 2-phenyl-4-5-methylimidazole and 2-pentylbenzimidazole.

8. A method for preparing a low-temperature pre-coating colorant, characterized in that: Using the low-temperature pre-coating colorant composition as described in any one of claims 1 to 7, comprising the following steps: Step S1, adding each component of the film-forming agent to the co-solvent in sequence, stirring sufficiently to completely dissolve the solid components, and obtaining a first solution; Step S2, adding dye to the first solution, and grinding using a grinder for at least 2 hours to obtain a second solution; Step S3, adding the active agent, the surfactant, and the corrosion inhibitor to the solvent in sequence to obtain a third solution; Step S4, adding the third solution into the second solution, keeping the grinder running during the adding process, and continuing grinding for at least 1 hour after the two solutions are basically mixed to obtain the low-temperature pre-coating colorant.

9. A low temperature colored pre-coated solder strip, characterized in that: It comprises a conductive substrate and a low-temperature pre-coating colorant coated on the conductive substrate, wherein the low-temperature pre-coating colorant is prepared by the preparation method of the low-temperature pre-coating colorant according to claim 8; The conductive substrate comprises a low-temperature tin-coated solder strip with copper, aluminum or a copper-aluminum composite material as a base and a low-temperature solder as a wrapping layer.

10. A method for preparing a low-temperature colored pre-coated solder strip, characterized in that: The following steps are involved: Step a, coating a low-temperature pre-coating colorant, uniformly coating the low-temperature pre-coating colorant according to claim 9 on the surface of the conductive substrate to form a low-temperature pre-coating colorant wet film, wherein the thickness of the low-temperature pre-coating colorant wet film is 5 to 10 μm; Step b, drying, preheating and drying the low-temperature pre-coated colorant wet film on the surface of the conductive substrate in step a through a drying tunnel to form a low-temperature pre-coated colorant layer, setting the preheating section temperature of the drying tunnel to 70-80° C., the constant temperature section temperature to 100-120° C., and the drying time to 2-5 min to obtain a low-temperature colored pre-coated welding strip; The thickness of the low-temperature pre-coating colorant layer is 2 to 5 μm.