Photovoltaic profile and preparation method and application thereof

Abstract

The invention belongs to the technical field of photovoltaic materials, and provides a photovoltaic profile and a preparation method and application thereof. The preparation method comprises the following steps: carrying out surface conditioning and phosphorization on a steel substrate (carbon steel or recycled steel or low alloy steel), carrying out electrophoretic deposition by using epoxy thermosetting electrophoretic primer, and pre-drying; the outer surface of a workpiece is coated with fluorocarbon finish paint (the fluorocarbon finish paint comprises the following raw materials in specific content: polyester resin with a certain viscosity hydroxyl value, fluorocarbon resin with a certain viscosity hydroxyl value, pigment filler, an organic solvent, a wetting leveling agent, a dispersing agent, a defoaming agent, an adhesion promoter and an aliphatic isocyanate curing agent), and curing is performed. And an electrophoretic primer layer with the thickness of 15-25 microns and a fluorocarbon finish layer with the thickness of 20-30 microns are formed on the outer surface of the steel substrate through curing. According to the photovoltaic profile, the electrophoretic primer layer and the fluorocarbon finish paint layer are formed on the low-cost steel substrate through one-time curing, the process can be simplified, the cost can be reduced, the paint layer is thin, and the photovoltaic profile further has long-term excellent adhesive force, aging resistance, corrosion resistance, weather resistance, gloss retention and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic materials, and in particular to a photovoltaic profile and a preparation method and application thereof. Background Art

[0002] Currently, the metal profiles commonly used in photovoltaic modules (such as photovoltaic brackets, photovoltaic frames, etc.) are made of aluminum (as shown in publication number CN110218923A) or galvanized aluminum-magnesium steel (i.e., a zinc-aluminum-magnesium coating is applied to the outer surface of bare steel). However, aluminum profiles need to be anodized before they can be used as photovoltaic frames, which makes the overall cost relatively high (6-9 times the price of carbon steel, recycled steel, or low-alloy steel). The current market price of photovoltaic modules continues to decline, and the high price of aluminum profiles makes it difficult for them to fit into the current industry's cost structure and pricing logic. Moreover, the thermal expansion coefficient of aluminum is 2.67 times that of glass, and the thermal expansion coefficient of steel is 1.3 times that of glass. Compared with steel, aluminum increases the risk of glass cracking due to thermal expansion, causing immeasurable damage to photovoltaic modules. At the same time, aluminum has poor mechanical properties, making it difficult to safely survive extreme outdoor weather (strong winds, hail, etc.).

[0003] When galvanized aluminum-magnesium steel is used as a photovoltaic bracket or photovoltaic frame outdoors, it will have the following disadvantages:

[0004] (1) The cost of galvanized aluminum-magnesium steel is higher than that of carbon steel, recycled steel or low alloy steel (2-4 times the price of carbon steel, recycled steel or low alloy steel).

[0005] (2) Black spots (black oxides such as magnesium oxide) will appear on the zinc-aluminum-magnesium coating in a short period of time during outdoor use, so its appearance quality is poor and customers have low acceptance of it, which affects the promotion of zinc-aluminum-magnesium steel products. It is only suitable for some low-end projects that have no requirements for appearance.

[0006] (3) When galvanized aluminum-magnesium steel is cold-bent, the zinc-magnesium-aluminum coating is prone to cracking or even falling off, affecting the service life of the product (it is difficult to meet the 25-year outdoor service life requirement of photovoltaic modules).

[0007] (4) Due to its electrical conductivity, when installing electrical equipment in a photovoltaic power station, the original galvanized aluminum-magnesium steel frame needs to be insulated or sprayed with an insulating protective coating during production and use to prevent safety hazards.

[0008] (5) The corrosion resistance and aging resistance of the zinc-aluminum-magnesium coating itself are not enough to meet the requirements of 25 years. It needs to be protected by a protective coating to extend its service life to meet the use requirements of photovoltaic modules.

[0009] (6) The chemical activity of zinc-aluminum-magnesium alloy is too high, black oxides such as magnesium oxide are easily produced on the surface, the density is not high, and there are impurities on the surface, which makes it difficult for the coating to adhere to its surface. Especially in the aging tests such as boiling water resistance, high temperature cooking PCT, double 85 humidity and heat, and humidity and freezing cycles, the paint film is very easy to bubble and delaminate, making it difficult to meet the comprehensive performance requirements of high-quality photovoltaic profiles.

[0010] Therefore, it is a more reasonable choice to select carbon steel, recycled steel, or low-alloy steel as the common metal material for photovoltaic brackets and photovoltaic frames due to its low cost, excellent strength, good processing performance, and strong coating adhesion. However, the corrosion resistance and weather resistance of carbon steel, recycled steel, or low-alloy steel itself do not meet the requirements of photovoltaic modules and require corresponding protective coating protection. However, the film thickness of the heavy-duty anti-corrosion coating protection system for carbon steel, recycled steel, or low-alloy steel on the market is generally above 200μm, generally including a primer to increase sealing and adhesion, a topcoat to improve weather resistance and surface decoration, and even a midcoat to improve durability. It must undergo two or three spraying processes. The coating process is cumbersome and the film thickness is high, which is not conducive to installation and has high costs. Summary of the Invention

[0011] The purpose of the present invention is to provide a photovoltaic profile and a preparation method and application thereof in view of the deficiencies in the prior art.

[0012] Based on this, the present invention discloses a method for preparing a photovoltaic profile, comprising the following preparation steps:

[0013] Step S1: After the steel substrate is subjected to surface conditioning and phosphating in sequence, it is placed in an electrophoretic tank containing an electrophoretic primer for electrophoretic deposition and pre-drying;

[0014] Wherein, the steel substrate is carbon steel, recycled steel or low alloy steel; the electrophoretic primer is epoxy thermosetting electrophoretic paint;

[0015] Step S2: applying a fluorocarbon topcoat on the outer surface of the pre-dried workpiece and curing the workpiece to form an electrophoretic primer layer with a dry film thickness of 15-25 μm and a fluorocarbon topcoat layer with a dry film thickness of 20-30 μm on the outer surface of the steel substrate;

[0016] The fluorocarbon topcoat comprises the following raw materials in parts by weight: 25-40 parts of polyester resin, 20-30 parts of fluorocarbon resin, 5-10 parts of pigments and fillers, 5-15 parts of organic solvents, 1-2 parts of wetting and leveling agents, 1.5-2.5 parts of dispersants, 0.5-1.5 parts of defoaming agents, 2-4 parts of adhesion promoters, and 8-15 parts of aliphatic isocyanate curing agents;

[0017] The polyester resin has a viscosity of 1000-2000 mPa·s and a hydroxyl value of 60-80 mgKOH / g; the fluorocarbon resin has a viscosity of 500-1500 mPa·s and a hydroxyl value of 40-80 mgKOH / g.

[0018] Preferably, step S1 specifically includes: conditioning the degreased steel substrate in a conditioning liquid at room temperature for 50-80 seconds, then phosphating in a phosphating liquid at 35-40°C for 180-300 seconds, washing twice with water, and then immersing in an electrophoresis tank liquid at 30-35°C for 100-200 seconds for electrophoretic deposition, and then pre-drying after ultrafiltration cleaning and water washing.

[0019] Further preferably, the pH value of the surface conditioning solution is controlled at 7-8; the total acidity of the phosphating solution is 20-25pt, the free acid point is 1-1.5pt, the accelerator point is 2-4pt, and the pH is controlled at 3.0-3.2.

[0020] Preferably, the epoxy thermosetting electrophoretic paint has a solid content of 13-17%, a pigment-to-binder ratio of 8-12, a pH of 5.2-6.2, and a reaction voltage of 150-240 V (such as PPG's CR681-1000K-C1).

[0021] Preferably, in step S1, the pre-drying conditions include: pre-drying at 100-120°C for 10-20 minutes;

[0022] In step S2, the fluorocarbon topcoat is a one-component fluorocarbon coating (which is prepared according to a conventional method; for example, the raw materials of the one-component fluorocarbon coating are mixed evenly. Preferably, the raw materials are mixed in a stainless steel container with a safety device, and the stirring speed during mixing is preferably 2500-3500 r / min, and the mixing time is preferably 40-60 min to obtain a one-component fluorocarbon coating), and the coating method is spraying; the curing conditions include: baking at 150-180°C for 12-20 min.

[0023] Preferably, the polyester resin is at least one of KN9282P polyester resin from KELISEN, WF-P220 polyester resin from WANBO New Materials, and NL387-6-70 polyester resin from KANGMING Chemical.

[0024] The fluorocarbon resin is at least one of Wanbo New Materials' fluorocarbon resin WH-Q212, Wanbo New Materials' fluorocarbon resin WF-J318, and Futang New Materials' fluorocarbon resin FC-5510.

[0025] Preferably, the adhesion promoter is Weina New Material Adhesion Promoter SY-5621 and / or Nengde New Material Adhesion Promoter ADP-s472;

[0026] The aliphatic isocyanate curing agent is at least one of blocked isophorone diisocyanate, blocked hexamethylene diisocyanate, blocked 4,4'-dicyclohexylmethane diisocyanate, blocked methylcyclohexyl diisocyanate, blocked trimethylhexamethylene diisocyanate, and blocked xylylene diisocyanate;

[0027] The wetting and leveling agent is Weina New Material Wetting and Leveling Agent SY-245 and / or Wuse Stone New Material Wetting and Leveling Agent WSS-707W;

[0028] The dispersant is at least one of Changxing Xiehe polymer SD-2400, Lida chemical dispersant LD-124 and LD-1651;

[0029] The defoaming agent is Xintike Chemical Defoamer 690, Xianchuang Chemical Defoamer At least one of PL and BYK defoamer BYK141;

[0030] The pigment filler is at least one of titanium dioxide, matting powder, fumed silica, carbon black, copper chrome black, aluminum silver paste, cobalt green, and cobalt chrome green;

[0031] The organic solvent is at least one of butyl acetate, propylene glycol methyl ether acetate, butyl acetate, ethylene glycol monoethyl ether, and ethylene glycol butyl ether.

[0032] Further preferably, the steel matrix comprises the following components by weight: 0.25-0.6% carbon, 0.1-1% silicon, 1.5-2.5% metal elements other than iron, and the remainder being iron.

[0033] The present invention also discloses a photovoltaic profile, which is prepared by the method for preparing the photovoltaic profile described above in the present invention.

[0034] The present invention also discloses an application of a photovoltaic profile, wherein the photovoltaic profile is used as a photovoltaic frame and / or a photovoltaic bracket in a photovoltaic module.

[0035] Compared with the prior art, the present invention has at least the following beneficial effects:

[0036] (1) The photovoltaic profile of the present invention has a significant cost advantage: existing photovoltaic profiles (such as photovoltaic brackets and photovoltaic frames) are commonly made of aluminum or galvanized aluminum-magnesium steel. The cost of aluminum is 6-9 times the price of carbon steel / recycled steel / low-alloy steel, and the cost of galvanized aluminum-magnesium steel is 2-4 times the price of carbon steel / recycled steel / low-alloy steel;

[0037] (2) Reduce the risk of glass cracking in photovoltaic modules: The thermal expansion coefficient of aluminum is 2.67 times that of glass, while the thermal expansion coefficient of steel is 1.3 times that of glass. The present invention uses steel (carbon steel, recycled steel, or low-alloy steel) as the base material, which can effectively reduce the risk of glass cracking due to thermal expansion compared to aluminum, and better protect photovoltaic modules.

[0038] (3) Better mechanical properties: Aluminum has poor mechanical properties and is difficult to withstand extreme weather conditions such as strong winds and hail. The carbon steel, recycled steel, or low-alloy steel used in the present invention has better mechanical properties and can ensure the safety of photovoltaic modules in extreme weather conditions.

[0039] (4) Good appearance quality: Galvanized aluminum-magnesium steel will develop black spots in the short term when used outdoors, resulting in poor appearance quality and low customer acceptance, making it only suitable for low-end projects. The present invention, by applying a special coating treatment (i.e., a functional coating of an electrophoretic primer layer + a fluorocarbon topcoat layer) to the outer surface of the steel substrate (carbon steel, recycled steel, or low-alloy steel), will not have appearance problems such as black spots, making it more easily accepted by the market.

[0040] (5) Good processing performance: The zinc-magnesium-aluminum coating of galvanized aluminum-magnesium steel is prone to cracking or even falling off during cold bending, which affects the service life of photovoltaic modules. The photovoltaic profile of the present invention has better processing performance and will not affect the service life due to processing.

[0041] (6) Higher safety: Galvanized aluminum-magnesium steel is conductive, and when installing electrical equipment in photovoltaic power plants, it needs to be insulated or sprayed with an insulating protective coating, which poses a safety hazard. The photovoltaic profile of the present invention is equipped with a functional coating of an electrophoretic primer layer and a fluorocarbon topcoat layer on the outer surface of the steel substrate (carbon steel, recycled steel, or low-alloy steel), which is completely insulated, thus avoiding this safety hazard through material selection.

[0042] (7) Excellent comprehensive performance such as corrosion resistance and weather resistance: The corrosion resistance and aging resistance of galvanized aluminum-magnesium steel itself are not enough to meet the requirements of 25 years, and protective coating protection is required; the corrosion resistance and weather resistance of carbon steel, recycled steel or low-alloy steel itself cannot meet the requirements of photovoltaic modules, and the film thickness of the heavy-duty anti-corrosion coating protection system on the market is generally above 200μm, and the coating process is cumbersome and costly. The photovoltaic profile of the present invention is equipped with a functional coating of an electrophoretic primer layer + a fluorocarbon topcoat layer on the outer surface of the steel substrate (carbon steel, recycled steel or low-alloy steel). By means of two coatings and one baking, while reducing the total film thickness of the functional coating (total film thickness is 35-55μm), the photovoltaic profile has more long-term excellent adhesion, aging resistance, corrosion resistance, weather resistance and light retention, etc., meeting the outdoor service life of 25-30 years; and it simplifies the coating process and reduces costs.

[0043] (8) High production efficiency: The present invention realizes one-time baking and curing of the electrophoretic primer layer and the fluorocarbon topcoat layer, which saves baking and curing time. Compared with the traditional process of multiple spraying and multiple curing, it greatly improves production efficiency and meets low-carbon requirements. DETAILED DESCRIPTION

[0044] 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.

[0045] A photovoltaic profile of the present invention comprises a steel substrate, wherein the steel substrate is carbon steel, recycled steel or low alloy steel, and an electrophoretic primer layer and a fluorocarbon topcoat layer are sequentially provided on the outer surface of the steel substrate.

[0046] The steel matrix (carbon steel or recycled steel or low alloy steel) comprises the following raw materials by weight percentage: carbon content 0.25-0.6%, silicon content 0.1-1%, metal element (excluding iron) content 1.5-2.5%, and the rest is iron.

[0047] The single-component fluorocarbon coating used in the fluorocarbon topcoat layer comprises the following raw materials, by weight: 25-40 parts polyester resin, 20-30 parts fluorocarbon resin, 5-10 parts pigments and fillers, 5-15 parts organic solvents, 5-10 parts additives, and 8-15 parts aliphatic isocyanate curing agent. The polyester resin has a viscosity of 1000-2000 mPa·s (25°C) and a hydroxyl value of 60-80 mgKOH / g; the fluorocarbon resin has a viscosity of 500-1500 mPa·s (25°C) and a hydroxyl value of 40-80 mgKOH / g. Additives include 1-2 parts wetting and leveling agent, 1.5-2.5 parts dispersant, 0.5-1.5 parts defoaming agent, and 2-4 parts adhesion promoter.

[0048] A method for preparing a photovoltaic profile of the present invention comprises the following steps:

[0049] Step 1, the degreased steel substrate is sequentially subjected to surface conditioning at room temperature (the pH value of the surface conditioning liquid is controlled at 7-8, and the surface conditioning time is 50-80s), phosphating (the total acidity of the phosphating liquid is 20-25pt, the free acid point is 1-1.5pt, the accelerator point is 2-4pt, the pH is controlled at 3.0-3.2, the phosphating temperature is 35-40°C, and the phosphating time is 180-300s) and two water washings, and then enters the electrophoresis tank liquid at 30-35°C (the electrophoretic primer is an epoxy thermosetting electrophoretic paint with a solid content of 13-17%, a pigment-to-base ratio of 8-12, and a pH of 5.2-6.2), soaked for 100-200s under a reaction voltage of 150-240V for electrophoretic deposition, and after ultrafiltration cleaning and water washing, pre-dried at 100-120°C for 10-20min.

[0050] Step 2: spray a layer of one-component fluorocarbon coating directly on the outer surface of the pre-dried workpiece; cure at 150-180° C. for 12-20 min (complete one-time curing of the electrophoretic primer layer and the fluorocarbon topcoat layer) to form an electrophoretic primer layer with a dry film thickness of 15-25 μm on the outer surface of the steel substrate, and cure on the outer surface of the electrophoretic primer layer to form a fluorocarbon topcoat layer with a dry film thickness of 20-30 μm, with the total film thickness controlled at 35-55 μm.

[0051] The photovoltaic profile of the present invention is used as a photovoltaic frame and / or a photovoltaic bracket in a photovoltaic module.

[0052] Specific embodiments of a photovoltaic profile, a preparation method, and an application thereof of the present invention are shown below.

[0053] Example 1

[0054] A photovoltaic profile of this embodiment includes a steel substrate, which is carbon steel, recycled steel, or low-alloy steel. The outer surface of the steel substrate is sequentially provided with an electrophoretic primer layer and a fluorocarbon topcoat layer.

[0055] Specifically, the steel matrix composition of this embodiment includes the following raw materials, calculated by weight percentage: carbon content 0.4%, silicon content 0.3%, metal element (except iron) content 2%, and the rest iron.

[0056] Specifically, the single-component fluorocarbon coating used for the fluorocarbon topcoat layer of this embodiment includes the following raw materials, by weight: 35 parts of Wanbo New Materials polyester resin WF-P220, 25 parts of Wanbo New Materials fluorocarbon resin WF-J318, 2.0 parts of matting powder, 1.0 part of fumed silica, 4 parts of aluminum silver paste, 10 parts of propylene glycol methyl ether acetate, 1 part of Wuse Stone New Materials wetting and leveling agent WSS-707W, 2 parts of Changxing Xiehe polymer dispersant SD-2400, 0.7 parts of Xintike Chemical defoaming agent 690, 3 parts of Nengde New Materials adhesion promoter ADP-s472, and 12 parts of blocked hexamethylene diisocyanate.

[0057] Specifically, the electrophoretic primer of this embodiment uses PPG's CR681-1000K-C1.

[0058] A method for preparing a photovoltaic profile in this embodiment includes the following steps:

[0059] Step 1: After degreasing, the steel substrate is subjected to surface conditioning at room temperature for 60 seconds, with the surface conditioning solution having a pH of 7.5; then phosphating at 38°C for 240 seconds, controlling the total acidity of the phosphating solution to 22pt, the free acid point to 1.5pt, the accelerator point to 3.5pt, and the pH to 3.1; after two water washes, the substrate is placed in a 35°C electrophoresis tank (PPG's CR681-1000K-C1 is used as the electrophoretic primer), immersed for 200 seconds at a reaction voltage of 200V for electrophoretic deposition, and the wet film thickness is controlled to 135μm (the dry film thickness of the electrophoretic primer layer is 20μm). After ultrafiltration cleaning and water washing, the substrate is pre-dried at 110°C for 15 minutes.

[0060] Step 2: spray a layer of one-component fluorocarbon coating directly on the outer surface of the pre-dried workpiece; cure at 150° C. for 12 minutes (complete one-time curing of the electrophoretic primer layer and the fluorocarbon topcoat layer) to form an electrophoretic primer layer with a dry film thickness of 20 μm on the outer surface of the steel substrate, and cure on the outer surface of the electrophoretic primer layer to form a fluorocarbon topcoat layer with a dry film thickness of 30 μm, and the total film thickness is controlled at 50 μm.

[0061] In one application of the photovoltaic profile of this embodiment, the photovoltaic profile is used as a photovoltaic frame and / or a photovoltaic bracket in a photovoltaic module.

[0062] Example 2

[0063] The photovoltaic profile, preparation method, and application of this embodiment refer to Example 1. The difference between this embodiment and Example 1 is that:

[0064] In step 1 of this embodiment, the phosphating temperature is 40° C., the phosphating time is 200 s, the total acidity of the phosphating solution is controlled to be 24 pt, the accelerator point is 4 pt, and the pH is controlled at 3.0; the remaining process parameters, raw materials, and weight parts of this embodiment are all referenced to Example 1.

[0065] Example 3

[0066] The photovoltaic profile, preparation method, and application of this embodiment refer to Example 1. The difference between this embodiment and Example 1 is that:

[0067] In step 1 of this embodiment, the reaction voltage in the electrophoretic tank liquid is 240 V, and the wet film thickness is 170 μm (the dry film thickness of the electrophoretic primer layer is 25 μm); the remaining process parameters, raw materials and weight parts of this embodiment are all referenced to Example 1.

[0068] Example 4

[0069] The photovoltaic profile, preparation method, and application of this embodiment refer to Example 1. The difference between this embodiment and Example 1 is that:

[0070] In step 1 of this embodiment, the reaction voltage in the electrophoretic tank liquid is 160 V, and the wet film thickness is 100 μm (the dry film thickness of the electrophoretic primer layer is 15 μm); the remaining process parameters, raw materials and weight parts of this embodiment are all referenced to Example 1.

[0071] Example 5

[0072] The photovoltaic profile, preparation method, and application of this embodiment refer to Example 1. The difference between this embodiment and Example 1 is that:

[0073] In the one-component fluorocarbon coating of this embodiment, the weight fraction of Wanbo New Materials polyester resin WF-P220 is 30 parts and the weight fraction of Wanbo New Materials fluorocarbon resin WF-J318 is 30 parts; the remaining process parameters, raw materials and weight parts of this embodiment are all referenced to Example 1.

[0074] Example 6

[0075] The photovoltaic profile, preparation method, and application of this embodiment refer to Example 1. The difference between this embodiment and Example 1 is that:

[0076] In the one-component fluorocarbon coating of this embodiment, 35 parts of Wanbo New Materials polyester resin WF-P220 and 25 parts of Wanbo New Materials fluorocarbon resin WF-J318 in Example 1 are replaced by 40 parts of Colison polyester resin KN9282P and 20 parts of Futang New Materials fluorocarbon resin FC-5510, respectively; the remaining process parameters, raw materials and weight parts of this embodiment are all referenced to Example 1.

[0077] Example 7

[0078] The photovoltaic profile, preparation method, and application of this embodiment refer to Example 6. The difference between this embodiment and Example 6 is that:

[0079] In the one-component fluorocarbon coating of this embodiment, 1 part of Wuse Stone New Material wetting and leveling agent WSS-707W and 2 parts of Changxing Xiehe polymer dispersant SD-2400 in Example 6 are replaced by 1 part of Weiner New Material wetting and leveling agent SY-245 and 2 parts of Lida Chemical dispersant LD-124 respectively; the remaining process parameters, raw materials and weight parts of this embodiment are all referred to Example 6.

[0080] Example 8

[0081] The photovoltaic profile, preparation method, and application of this embodiment refer to Example 7. The difference between this embodiment and Example 7 is that:

[0082] In the one-component fluorocarbon coating of this embodiment, 0.7 parts of Xintek Chemical Defoamer 690 and 3 parts of Nengde New Material Adhesion Promoter ADP-s472 in Example 7 are replaced by 0.7 parts of Xianchuang Chemical Defoamer PL and 3 parts of Weiner New Material Adhesion Promoter SY-5621; the remaining process parameters, raw materials and weight parts of this embodiment are all referenced to Example 7.

[0083] Example 9

[0084] The photovoltaic profile, preparation method, and application of this embodiment refer to Example 8, and the difference between this embodiment and Example 8 is that:

[0085] In the one-component fluorocarbon coating of this embodiment, 12 parts of blocked hexamethylene diisocyanate in Example 8 are replaced by 15 parts of blocked isophorone diisocyanate; the remaining process parameters, raw materials and weight parts of this embodiment are all referenced to Example 8.

[0086] Example 10

[0087] The photovoltaic profile, preparation method, and application of this embodiment refer to Example 9, and the difference between this embodiment and Example 9 is that:

[0088] In step 2 of this embodiment, the dry film thickness of the fluorocarbon topcoat layer is 20 μm, and the total film thickness is 40 μm; the remaining process parameters, raw materials and weight parts of this embodiment are all referenced to Example 9.

[0089] Comparative Example 1

[0090] A photovoltaic profile, a preparation method thereof, and an application thereof in this comparative example are described with reference to Example 1. The difference between this comparative example and Example 1 is that:

[0091] In step 1 of this comparative example, the electrophoretic primer was pre-dried at 110°C for 15 minutes and then directly cured at 150°C for 12 minutes, without using a single-component fluorocarbon coating. The remaining process parameters, raw materials and weight parts of this comparative example were all referenced to Example 1.

[0092] Comparative Example 2

[0093] A photovoltaic profile, a preparation method thereof, and an application thereof in this comparative example are described with reference to Example 1. The difference between this comparative example and Example 1 is that:

[0094] In step 1 of this comparative example, the steel substrate is phosphated and not subjected to electrophoretic deposition treatment. After ultrafiltration cleaning, water washing and pre-drying at 110°C for 15 minutes, it directly enters step 2 (i.e., directly spraying a layer of single-component fluorocarbon coating and then curing); the remaining process parameters, raw materials and weight parts of this comparative example are all referred to Example 1.

[0095] Comparative Example 3

[0096] A photovoltaic profile, a preparation method thereof, and an application thereof in this comparative example are described with reference to Example 1. The difference between this comparative example and Example 1 is that:

[0097] In step 1 of the present comparative example, the total acidity of the phosphating solution used for phosphating is 18 pt, the free acid point is 0.84 pt, and the promoter point is 1.5 pt; the remaining process parameters, raw materials and weight parts of the present comparative example are all referred to Example 1.

[0098] Comparative Example 4

[0099] The photovoltaic profile, the preparation method and the application of the present comparative example are referred to Example 1, and the difference between the present comparative example and Example 1 is that:

[0100] In step 1 of the present comparative example, the reaction voltage of the electrophoresis tank is 260 V, and the soaking time is 180 s; the remaining process parameters, raw materials and weight parts of the present comparative example are all referred to Example 1.

[0101] Comparative Example 5

[0102] The photovoltaic profile, the preparation method and the application of the present comparative example are referred to Example 1, and the difference between the present comparative example and Example 1 is that:

[0103] In the single-component fluorocarbon paint of the present comparative example, the weight fraction of Wanbo New Material polyester resin WF-P220 is 20 parts, and the weight fraction of Wanbo New Material fluorocarbon resin WF-J318 is 36 parts; the remaining process parameters, raw materials and weight parts of the present comparative example are all referred to Example 1.

[0104] Comparative Example 6

[0105] The photovoltaic profile, the preparation method and the application of the present comparative example are referred to Example 1, and the difference between the present comparative example and Example 1 is that:

[0106] In the single-component fluorocarbon paint of the present comparative example, the weight fraction of Wanbo New Material polyester resin WF-P220 is 45 parts, and the weight fraction of Wanbo New Material fluorocarbon resin WF-J318 is 18 parts; the remaining process parameters, raw materials and weight parts of the present comparative example are all referred to Example 1.

[0107] Comparative Example 7

[0108] The photovoltaic profile, the preparation method and the application of the present comparative example are referred to Example 1, and the difference between the present comparative example and Example 1 is that:

[0109] In the single-component fluorocarbon paint of the present comparative example, the weight fraction of Wusishixin Material wetting and leveling agent WSS-707W is 0.6 parts, and the weight fraction of Changxinghehe High Polymer dispersant SD-2400 is 1 part; the remaining process parameters, raw materials and weight parts of the present comparative example are all referred to Example 1.

[0110] Comparative Example 8

[0111] The photovoltaic profile, the preparation method and the application of the present comparative example are referred to Example 1, and the difference between the present comparative example and Example 1 is that:

[0112] In the one-component fluorocarbon coating of this comparative example, the weight portion of Nengde New Material Adhesion Promoter ADP-s472 is 1.2 parts; the remaining process parameters, raw materials and weight portions of this comparative example are all referenced to Example 1.

[0113] Comparative Example 9

[0114] A photovoltaic profile, a preparation method thereof, and an application thereof in this comparative example are described with reference to Example 1. The difference between this comparative example and Example 1 is that:

[0115] In the one-component fluorocarbon coating of this comparative example, the weight portion of blocked hexamethylene diisocyanate is 6 parts; the remaining process parameters, raw materials and weight portions of this comparative example are all referenced to Example 1.

[0116] Comparative Example 10

[0117] A photovoltaic profile, a preparation method thereof, and an application thereof in this comparative example are described with reference to Example 1. The difference between this comparative example and Example 1 is that:

[0118] In step 2 of this comparative example, the curing condition is to maintain the temperature at 130° C. for 12 minutes; the remaining process parameters, raw materials and weight parts of this comparative example are all referenced to Example 1.

[0119] Performance Testing

[0120] The functional coating of the electrophoretic primer layer + fluorocarbon topcoat layer in the photovoltaic profiles of Examples 1 to 10 and Comparative Examples 1 to 10, and the ordinary outdoor heavy-duty anti-corrosion coating in the existing photovoltaic profiles, were subjected to the following performance tests: boiling water aging resistance (100-grid strict test) test was performed with reference to GB / T1733; high temperature cooking aging resistance (PCT, 100-grid strict test) test was performed with reference to JESD22-A102-C; impact resistance test was performed with reference to GB / T1732-2020; and The product was tested for acid and alkali resistance and butanone wipe resistance according to GB / T 9274; neutral salt spray testing according to GB / T 2423.17-2024; high temperature and humidity aging testing (DH, a 100-grid test, a more stringent test) according to GB / T 2423.3-2016; humidity freeze testing (HF, a 100-grid test, a more stringent test) and thermal cycling testing (TC, a 100-grid test, a more stringent test) according to GB / T 2423.34-2024, where one HF cycle lasts 24 hours and one TC cycle lasts 9 hours; and ultraviolet aging (UV) resistance and ultraviolet high temperature and humidity aging (UV+DH) resistance testing according to IEC TS 62788-7-2-2017. The test results are shown in Table 1-2 below.

[0121] Table 1

[0122]

[0123]

[0124] Table 2

[0125]

[0126]

[0127]

[0128] As can be seen from Table 1-2:

[0129] If, in the photovoltaic profile and the preparation method thereof, only an electrophoretic primer layer is prepared on the outer surface of the steel substrate (such as in Comparative Example 1), or only a fluorocarbon topcoat layer is prepared on the outer surface of the steel substrate (such as in Comparative Example 2), or the phosphating process parameters of step 1 exceed the protection scope of the present invention (such as in Comparative Example 3), or the electrophoretic reaction voltage is too high (such as in Comparative Example 4), or the polyester resin in the one-component fluorocarbon coating is too little and the fluorocarbon resin is too much (such as in Comparative Example 5), or the wetting and leveling agent and dispersant in the one-component fluorocarbon coating are too little (such as in Comparative Example 7), or the amount of adhesion promoter in the one-component fluorocarbon coating is too little (such as in Comparative Example 8), Or the amount of aliphatic isocyanate curing agent in the one-component fluorocarbon coating is too small (such as in Comparative Example 9), or the curing temperature in step 1 is too low (such as in Comparative Example 10); then the boiling water boiling aging adhesion, high temperature cooking aging PCT adhesion, humidity and freeze aging HF adhesion, high temperature and humidity aging DH, neutral salt spray resistance, UV aging resistance and UV+DH aging resistance of the functional coating composed of the electrophoretic primer layer + fluorocarbon topcoat layer of the photovoltaic profile will be deteriorated, and thus it will be impossible to effectively protect photovoltaic profiles (such as photovoltaic frames and photovoltaic brackets) with carbon steel, recycled steel or low alloy steel as the steel matrix in the long term.

[0130] However, if the single-component fluorocarbon coating in the photovoltaic profile contains too much polyester resin and too little fluorocarbon resin (such as in Comparative Example 6), the functional coating composed of the electrophoretic primer layer + fluorocarbon topcoat layer of the photovoltaic profile will have poor resistance to wet-freeze aging HF adhesion, acid and alkali resistance, butanone wiping resistance, neutral salt spray resistance, UV aging resistance and UV+DH aging resistance, and will not be able to effectively protect photovoltaic profiles with carbon steel, recycled steel or low-alloy steel as the steel matrix in the long term.

[0131] In conclusion, the photovoltaic profile of the present application is obtained by the following steps: after the carbon steel or recycled steel or low alloy steel is degreased, surface adjusted and phosphorized, the workpiece is pre-dried after electrophoretic deposition and water washing; then the single-component fluorocarbon paint is sprayed on the outer surface of the pre-dried workpiece, and the functional coating with high anti-aging adhesion, high weather resistance and high corrosion resistance is formed after curing; compared with the common two-coat two-bake or three-coat three-bake heavy anti-corrosion system (total film thickness ≥200μm) on the market, the total film thickness of the functional coating (electrophoretic primer layer + fluorocarbon topcoat layer) of the present application is significantly thinned (total film thickness is only 35-55μm), and the paint construction is simpler, and the material cost and construction cost are lower. Moreover, the functional coating of the electrophoretic primer layer + fluorocarbon topcoat layer of the present application has a longer-term excellent adhesion, anti-aging, corrosion resistance and weather resistance on the outer surface of the carbon steel or recycled steel or low alloy steel, which can simultaneously improve the boiling water resistance of the photovoltaic profile of the present application, the PCT adhesion of high temperature cooking aging, the HF adhesion of wet freezing aging, the impact resistance, the acid and alkali resistance, the butanone wiping resistance, the DH of high temperature and high humidity aging, the neutral salt spray resistance, the UV aging resistance and the UV+DH aging resistance, and the functional coating of the electrophoretic primer layer + fluorocarbon topcoat layer has good gloss retention performance, which can effectively protect the photovoltaic profile (such as photovoltaic frame and photovoltaic support) with carbon steel or recycled steel or low alloy steel as the steel substrate for a long time, and meet the long-term outdoor use requirements.

[0132] Although the preferred embodiments of the embodiments of the present application have been described, those skilled in the art can make further changes and modifications to the embodiments once they know the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including all changes and modifications falling within the scope of the embodiments of the present application.

[0133] The above describes the technical solutions provided by the present application in detail, and the principles and implementation modes of the present application are described by applying specific examples; the above description of the embodiments is only used to help understand the method of the present application and its core idea; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation modes and application ranges can be changed; in conclusion, the content of the present description should not be understood as a limitation of the present application.

Claims

1. A method for preparing a photovoltaic profile, characterized in that: The method comprises the following preparation steps: Step S1: After the steel substrate is subjected to surface conditioning and phosphating in sequence, it is placed in an electrophoretic tank containing an electrophoretic primer for electrophoretic deposition and pre-drying; Wherein, the steel substrate is carbon steel, recycled steel or low alloy steel; the electrophoretic primer is epoxy thermosetting electrophoretic paint; Step S2: applying a fluorocarbon topcoat on the outer surface of the pre-dried workpiece and curing the workpiece to form an electrophoretic primer layer with a dry film thickness of 15-25 μm and a fluorocarbon topcoat layer with a dry film thickness of 20-30 μm on the outer surface of the steel substrate; The fluorocarbon topcoat comprises the following raw materials in parts by weight: 25-40 parts of polyester resin, 20-30 parts of fluorocarbon resin, 5-10 parts of pigments and fillers, 5-15 parts of organic solvents, 1-2 parts of wetting and leveling agents, 1.5-2.5 parts of dispersants, 0.5-1.5 parts of defoaming agents, 2-4 parts of adhesion promoters, and 8-15 parts of aliphatic isocyanate curing agents; The polyester resin has a viscosity of 1000-2000 mPa·s and a hydroxyl value of 60-80 mgKOH / g; the fluorocarbon resin has a viscosity of 500-1500 mPa·s and a hydroxyl value of 40-80 mgKOH / g.

2. The method for preparing a photovoltaic profile according to claim 1, characterized in that: Step S1 specifically includes: conditioning the degreased steel substrate in a conditioning solution at room temperature for 50-80 seconds, then phosphating in a phosphating solution at 35-40°C for 180-300 seconds, washing twice with water, and then immersing in an electrophoresis tank at 30-35°C for 100-200 seconds for electrophoretic deposition, and then cleaning with ultrafiltration and washing with water, followed by pre-drying.

3. The method for preparing a photovoltaic profile according to claim 2, characterized in that: The pH value of the surface conditioning solution is controlled at 7-8; the total acidity of the phosphating solution is 20-25pt, the free acid point is 1-1.5pt, the accelerator point is 2-4pt, and the pH is controlled at 3.0-3.

2.

4. The photovoltaic profile according to claim 1, characterized in that: The epoxy thermosetting electrophoretic paint has a solid content of 13-17%, a pigment-to-binder ratio of 8-12, a pH of 5.2-6.2, and a reaction voltage of 150-240V.

5. The method for preparing a photovoltaic profile according to claim 1, characterized in that: In step S1, the pre-drying conditions include: pre-drying at 100-120°C for 10-20 minutes; In step S2, the fluorocarbon topcoat is a single-component fluorocarbon coating, and the coating method is spraying; the curing conditions include: baking at 150-180°C for 12-20 minutes.

6. The method for preparing a photovoltaic profile according to claim 1, characterized in that: The polyester resin is at least one of Kelison polyester resin KN9282P, Wanbo New Materials polyester resin WF-P220, and Kangming Chemical polyester resin NL387-6-70; The fluorocarbon resin is at least one of Wanbo New Materials' fluorocarbon resin WH-Q212, Wanbo New Materials' fluorocarbon resin WF-J318, and Futang New Materials' fluorocarbon resin FC-5510.

7. The method for preparing a photovoltaic profile according to claim 1, characterized in that: The adhesion promoter is Weina New Material Adhesion Promoter SY-5621 and / or Nengde New Material Adhesion Promoter ADP-s472; The aliphatic isocyanate curing agent is at least one of blocked isophorone diisocyanate, blocked hexamethylene diisocyanate, blocked 4,4'-dicyclohexylmethane diisocyanate, blocked methylcyclohexyl diisocyanate, blocked trimethylhexamethylene diisocyanate, and blocked xylylene diisocyanate; The wetting and leveling agent is Weina New Material Wetting and Leveling Agent SY-245 and / or Wuse Stone New Material Wetting and Leveling Agent WSS-707W; The dispersant is at least one of Changxing Xiehe polymer SD-2400, Lida chemical dispersant LD-124 and LD-1651; The defoaming agent is Xintike Chemical Defoamer 690, Xianchuang Chemical Defoamer At least one of 561PL and BYK defoamer BYK141; The pigment filler is at least one of titanium dioxide, matting powder, fumed silica, carbon black, copper chrome black, aluminum silver paste, cobalt green, and cobalt chrome green; The organic solvent is at least one of butyl acetate, propylene glycol methyl ether acetate, butyl acetate, ethylene glycol monoethyl ether, and ethylene glycol butyl ether.

8. The method for preparing a photovoltaic profile according to any one of claims 1 to 7, characterized in that: The steel matrix comprises the following components by weight percentage: carbon content 0.25-0.6%, silicon content 0.1-1%, metal element content excluding iron 1.5-2.5%, and the rest being iron.

9. A photovoltaic profile, characterized in that: The photovoltaic profile is prepared by the method for preparing the photovoltaic profile according to any one of claims 1 to 8.

10. The application of the photovoltaic profile according to claim 9, characterized in that: The photovoltaic profile is used as a photovoltaic frame and / or a photovoltaic bracket in a photovoltaic module.

Images