Waterborne coating for photovoltaic ribbon and method of making same

Abstract

The present application belongs to the technical field of water-based coating for photovoltaic welding strip, and particularly relates to a water-based coating for photovoltaic welding strip and a preparation method thereof, which comprises, by mass fraction, 30-40 parts of water-based acrylic emulsion, 15-30 parts of water-based fluorocarbon resin, 5-10 parts of water-based silicon resin, 1-5 parts of amino resin, 1-5 parts of blocking curing agent, 1-5 parts of dispersing agent, 0.2-1.5 parts of substrate wetting agent, 0.2-1.5 parts of defoaming agent, 0.2-1.5 parts of leveling agent, 5-10 parts of carbon black, 5-10 parts of glass microbead, 5-10 parts of zinc phosphate, 10-15 parts of deionized water, and the like. After the conventional water-based acrylic, fluorocarbon resin and amino resin are cured with the blocking isocyanate, the water-based silicon resin is further used for secondary curing to form a three-dimensional network structure, so that the compactness of the paint film and the adhesion to the substrate are greatly improved, and the long-term stable operation of the photovoltaic welding strip is ensured.

Description

Technical Field

[0001] This invention belongs to the field of water-based coatings for photovoltaic welding strips, specifically relating to a water-based coating for photovoltaic welding strips and its preparation method. Background Technology

[0002] Photovoltaic solder ribbon, also known as photovoltaic tin-coated solder ribbon, tin-immersed solder ribbon for photovoltaic modules, or tin-coated solder ribbon for solar cells, is a composite conductive material formed by coating a certain thickness of tin-based solder onto the surface of a copper strip of a specific size. Photovoltaic solder ribbon is an important component of photovoltaic modules, belonging to electrical connection parts. It is used in the series or parallel connection of photovoltaic cells, playing a crucial role in conductivity and electricity concentration to improve the output voltage and power of the photovoltaic module.

[0003] Existing technologies typically coat both sides of photovoltaic solder ribbons with tin. However, tin-coated solder ribbons have poor weather resistance and are prone to aging and peeling off during long-term use. There is an urgent need for a coating material for photovoltaic solder ribbons that can replace tin. Summary of the Invention

[0004] This invention provides a water-based coating for photovoltaic solder ribbon and its preparation method to solve the problem of poor aging resistance of existing photovoltaic solder ribbons with tin coating.

[0005] To address the aforementioned technical problems, this invention provides a water-based coating for photovoltaic welding ribbons, comprising, by weight parts: 30-40 parts of water-based acrylic emulsion; 15-30 parts of water-based fluorocarbon resin; 5-10 parts of water-based silicone resin; 1-5 parts of amino resin; 1-5 parts of blocked curing agent; 1-5 parts of dispersant; 0.2-1.5 parts of substrate wetting agent; 0.2-1.5 parts of defoamer; 0.2-1.5 parts of leveling agent; 5-10 parts of carbon black; 5-10 parts of glass microspheres; 5-10 parts of zinc phosphate; and 10-15 parts of deionized water.

[0006] In another aspect, the present invention provides a method for preparing a water-based coating for photovoltaic welding ribbon, comprising the following steps: Step S1, grinding carbon black, glass microspheres and zinc phosphate, and stirring with dispersant, substrate wetting agent, defoamer, leveling agent and deionized water to obtain a color paste; Step S2, sequentially adding water-based acrylic emulsion, water-based fluorocarbon resin, water-based silicone resin, amino resin and blocking curing agent to the color paste, stirring evenly to obtain a water-based coating for photovoltaic welding ribbon.

[0007] The beneficial effects of this invention are that the photovoltaic solder ribbon water-based coating and its preparation method of this invention, after curing conventional water-based acrylic resin with fluorocarbon resin, amino resin with blocked isocyanate, and then further curing with water-based silicone resin to form a three-dimensional network structure, greatly improves the density of the coating film and its adhesion to the substrate. On the basis of realizing the basic functions of existing solder ribbons, it provides high weather resistance protection for tin-plated solder ribbons, so that the coating film does not change under high temperature, electric welding and other environments, and ensures the long-term stable operation of photovoltaic solder ribbons.

[0008] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention.

[0009] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below. Detailed Implementation

[0010] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0011] This invention provides a water-based coating for photovoltaic welding ribbons, comprising, by weight parts: 30-40 parts of water-based acrylic emulsion; 15-30 parts of water-based fluorocarbon resin; 5-10 parts of water-based silicone resin; 1-5 parts of amino resin; 1-5 parts of blocked curing agent; 1-5 parts of dispersant; 0.2-1.5 parts of substrate wetting agent; 0.2-1.5 parts of defoamer; 0.2-1.5 parts of leveling agent; 5-10 parts of carbon black; 5-10 parts of glass microspheres; 5-10 parts of zinc phosphate; and 10-15 parts of deionized water.

[0012] In this embodiment, specifically, the aqueous acrylic emulsion includes any one or more combinations of pure acrylic emulsion, silicone acrylic emulsion, styrene acrylic emulsion, and vinyl acetate acrylic emulsion.

[0013] In this embodiment, specifically, the waterborne fluorocarbon resin includes any one or more combinations of PVDF, FEVE, PTFE, FEP, and PFA.

[0014] In this embodiment, specifically, the aqueous silicone resin includes any one or more combinations of methyltrichlorosilane, dimethyldichlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, and methylphenyldichlorosilane.

[0015] In this embodiment, specifically, the amino resin includes any one or a combination of urea-formaldehyde resin, melamine-formaldehyde resin, benzo-melamine resin, and polyamide-polyamine epichlorohydrin resin.

[0016] In this embodiment, specifically, the blocked curing agent includes one or more of the following: blocked HDI trimer, blocked H6XDI adduct, and blocked XDI adduct.

[0017] In this embodiment, specifically, the dispersant includes one or more of the following: anionic wetting and dispersing agents, cationic wetting and dispersing agents, nonionic wetting and dispersing agents, amphoteric wetting and dispersing agents, polymeric superdispersants, and controlled free radical superdispersants.

[0018] In this embodiment, specifically, the substrate wetting agent is at least one of BYK-345, BYK-346, BYK-349, TEGO-Wet240, TEGO-Twin 4100, TEGO-Wet 270, and DYNOL-360.

[0019] In this embodiment, the defoamer is specifically at least one of Tego-810, BYK-024, and Tego-902w.

[0020] In this embodiment, specifically, the leveling agent includes one or more of the following: acrylic leveling agent, silicone leveling agent, fluorosilicone leveling agent, and high-boiling-point solvent.

[0021] In another aspect, the present invention provides a method for preparing a water-based coating for photovoltaic welding ribbon, comprising the following steps: Step S1, grinding carbon black, glass microspheres and zinc phosphate, and stirring with dispersant, substrate wetting agent, defoamer, leveling agent and deionized water to obtain a color paste; Step S2, sequentially adding water-based acrylic emulsion, water-based fluorocarbon resin, water-based silicone resin, amino resin and blocking curing agent to the color paste, stirring evenly to obtain a water-based coating for photovoltaic welding ribbon.

[0022] In this embodiment, specifically, the grinding fineness of carbon black, glass microspheres and zinc phosphate in step S1 is no greater than 15 mesh.

[0023] Example 1

[0024] A water-based coating for photovoltaic welding ribbon comprises, by weight parts: 35 parts water-based acrylic emulsion; 15 parts water-based fluorocarbon resin FEVE; 6 parts water-based silicone resin methyltrichlorosilane; 3 parts amino resin urea-formaldehyde resin; 2 parts blocked curing agent HDI; 3 parts dispersant 5040; 1 part substrate wetting agent BYK-345; 1 part defoamer Tego-810; 1 part leveling agent BYK-333; 6 parts carbon black; 6 parts glass microspheres; 5 parts zinc phosphate; and 15 parts deionized water.

[0025] The prepared photovoltaic ribbon was coated with a water-based coating on one side of the photovoltaic ribbon for testing.

[0026] Example 2

[0027] A water-based coating for photovoltaic welding ribbon comprises, by weight parts: 30 parts water-based acrylic emulsion; 20 parts water-based fluorocarbon resin FEVE; 8 parts water-based silicone resin methyltrichlorosilane; 3 parts amino resin urea-formaldehyde resin; 3 parts blocked curing agent HDI; 2 parts dispersant 5040; 1 part substrate wetting agent BYK-345; 1 part defoamer Tego-810; 1 part leveling agent BYK-333; 6 parts carbon black; 6 parts glass microspheres; 5 parts zinc phosphate; and 15 parts deionized water.

[0028] The prepared photovoltaic ribbon was coated with a water-based coating on one side of the photovoltaic ribbon for testing.

[0029] Example 3

[0030] A water-based coating for photovoltaic welding ribbon comprises, by weight parts: 30 parts water-based acrylic emulsion; 30 parts water-based fluorocarbon resin FEVE; 8 parts water-based silicone resin methyltrichlorosilane; 5 parts amino resin urea-formaldehyde resin; 3 parts blocked curing agent HDI; 2 parts dispersant 5040; 1 part substrate wetting agent BYK-345; 1 part defoamer Tego-810; 1 part leveling agent BYK-333; 6 parts carbon black; 6 parts glass microspheres; 5 parts zinc phosphate; and 15 parts deionized water.

[0031] The prepared photovoltaic ribbon was coated with a water-based coating on one side of the photovoltaic ribbon for testing.

[0032] Example 4

[0033] A water-based coating for photovoltaic welding ribbon comprises, by weight parts: 40 parts water-based acrylic emulsion; 15 parts water-based fluorocarbon resin FEVE; 10 parts water-based silicone resin methyltrichlorosilane; 1 part amino resin urea-formaldehyde resin; 5 parts blocked curing agent HDI; 1 part dispersant 5040; 1 part substrate wetting agent BYK-345; 1 part defoamer Tego-810; 1 part leveling agent BYK-333; 6 parts carbon black; 6 parts glass microspheres; 5 parts zinc phosphate; and 15 parts deionized water.

[0034] The prepared photovoltaic ribbon was coated with a water-based coating on one side of the photovoltaic ribbon for testing.

[0035] Example 5

[0036] A water-based coating for photovoltaic welding ribbon comprises, by weight parts: 40 parts water-based acrylic emulsion; 25 parts water-based fluorocarbon resin FEVE; 10 parts water-based silicone resin methyltrichlorosilane; 1 part amino resin urea-formaldehyde resin; 5 parts blocked curing agent HDI; 1 part dispersant 5040; 1 part substrate wetting agent BYK-345; 1 part defoamer Tego-810; 1 part leveling agent BYK-333; 6 parts carbon black; 6 parts glass microspheres; 5 parts zinc phosphate; and 15 parts deionized water.

[0037] The prepared photovoltaic ribbon was coated with a water-based coating on one side of the photovoltaic ribbon for testing.

[0038] Comparative Example 1

[0039] The conventional double-sided tin-coated photovoltaic solder ribbon was tested.

[0040]

[0041]

[0042] Specifically, double-sided tin-coated solder strips are not only more expensive, but more importantly, during continuous spot welding at high temperatures (around 400℃), the melting point of tin is low (231.89℃), and it is in a molten state during spot welding, which causes the coating film to wrinkle and crack, damaging the coating's protective function for the substrate.

[0043] In summary, the photovoltaic solder ribbon waterborne coating and its preparation method of the present invention, after curing conventional waterborne acrylic resin with fluorocarbon resin and amino resin with blocked isocyanate, further achieve secondary curing with waterborne silicone resin to form a three-dimensional network structure, greatly improves the density of the coating film and its adhesion to the substrate. On the basis of realizing the basic functions of existing solder ribbons, it provides high weather resistance protection for tin-plated solder ribbons, so that the coating film does not change under high temperature, electric welding and other environments, ensuring the long-term stable operation of photovoltaic solder ribbons.

[0044] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A water-based coating for photovoltaic welding ribbons, characterized in that, Included by weight parts: 30-40 parts of water-based acrylic emulsion; 15-30 parts of waterborne fluorocarbon resin; 5-10 parts of water-based silicone resin; 1-5 parts of amino resin; 1-5 parts of a sealed curing agent; 1-5 parts of dispersant; Substrate wetting agent: 0.2–1.5 parts; Defoamer 0.2–1.5 parts; Leveling agent 0.2–1.5 parts; 5-10 parts carbon black; 5-10 parts of glass microspheres; Zinc phosphate, 5-10 parts; 10-15 parts deionized water; The aqueous silicone resin includes any one or more combinations of methyltrichlorosilane, dimethyldichlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, and methylphenyldichlorosilane; The aqueous fluorocarbon resin is FEVE; The amino resin includes any one or more combinations of urea-formaldehyde resin, melamine-formaldehyde resin, benzo-melamine resin, and polyamide-polyamine epichlorohydrin resin. The method for preparing the water-based coating for the photovoltaic welding ribbon includes the following steps: Step S1: Grind carbon black, glass microspheres and zinc phosphate, and stir with dispersant, substrate wetting agent, defoamer, leveling agent and deionized water to prepare color paste; Step S2: Waterborne acrylic emulsion, waterborne fluorocarbon resin, waterborne silicone resin, amino resin and blocking curing agent are added to the color paste in sequence and stirred evenly to obtain waterborne coating for photovoltaic welding ribbon.

2. The water-based coating for photovoltaic welding strips as described in claim 1, characterized in that, The aqueous acrylic emulsion includes any one or more combinations of pure acrylic emulsion, silicone acrylic emulsion, styrene acrylic emulsion, and vinyl acetate acrylic emulsion.

3. The water-based coating for photovoltaic welding strips as described in claim 1, characterized in that, The blocked curing agent includes one or more of the following: blocked HDI trimer, blocked H6XDI adduct, and blocked XDI adduct; The dispersant includes one or more of the following: anionic wetting and dispersing agents, cationic wetting and dispersing agents, nonionic wetting and dispersing agents, and amphoteric wetting and dispersing agents; The substrate wetting agent is at least one of the following: BYK-345, BYK-346, BYK-349, TEGO-Wet 240, TEGO-Twin 4100, TEGO-Wet 270, and DYNOL-360; The defoamer is at least one of Tego-810, BYK-024, and Tego-902w; The leveling agent includes one or more of the following: acrylic leveling agent, silicone leveling agent, fluorosilicone leveling agent, and high-boiling-point solvent.

4. The water-based coating for photovoltaic welding strips as described in claim 1, characterized in that, In step S1, the grinding fineness of carbon black, glass microspheres, and zinc phosphate is no greater than 15 mesh.

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