Wear-resistant UV-curable polyacrylate coating as well as preparation method and application thereof

Abstract

The invention discloses a wear-resistant UV-curable polyacrylate coating, which is prepared from the following raw materials in parts by weight: 55 to 60 parts of hyperbranched polyurethane acrylate, 15 to 20 parts of modified hydrogen-containing silicone oil, 8 to 12 parts of modified nano silicon dioxide, 10 to 20 parts of hexanediol diacrylate and 2 to 4 parts of photoinitiator, wherein in the preparation process of the modified hydrogen-containing silicone oil, in an inert gas atmosphere, hydrogen-containing silicone oil, octavinyl silsesquioxane, a catalyst, a polymerization inhibitor and an organic solvent are uniformly mixed for reaction, the organic solvent is removed, and the modified hydrogen-containing silicone oil is obtained. The invention also discloses a preparation method of the wear-resistant UV-cured polyacrylate coating and application of the wear-resistant UV-cured polyacrylate coating in photovoltaic cells. The coating provided by the invention has good hardness and wear resistance, and has good transmittance.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, and in particular to a wear-resistant UV-cured polyacrylate coating and a preparation method and application thereof. Background Art

[0002] Solar photovoltaic cells have been widely used in various fields, especially back-contact cells. As a new generation of battery technology, its outstanding battery efficiency has been favored by the market and has become a hot development direction. Back-contact cells require special protection due to the special characteristics of the front of the battery.

[0003] However, the surface hardness of existing coatings is low and not scratch-resistant. They are easily scratched and fogged during use and preparation, resulting in reduced transmittance, which in turn affects the photoelectric conversion of photovoltaic cells. At present, the hardness of the coating is often increased by adding a large amount of inorganic fillers, but inorganic fillers are not easy to disperse in organic matter, and agglomerated fillers will reduce the transmittance of the coating. In addition, inorganic fillers are prone to sedimentation during storage; and the introduction of fillers will make the coating rough, causing light reflection and reducing the utilization rate of light energy; in addition, the fillers are easily scratched and fall off during use, reducing its wear resistance. Therefore, it is urgent to provide a coating with both transmittance and wear resistance. Summary of the invention

[0004] Based on the technical problems existing in the background technology, the present invention proposes a wear-resistant UV-cured polyacrylate coating and a preparation method and application thereof. The coating of the present invention has good hardness and wear resistance, and has good transmittance.

[0005] The invention provides a wear-resistant UV-curing polyacrylate coating, wherein the raw materials thereof include, by weight: 55-60 parts of hyperbranched polyurethane acrylate, 15-20 parts of modified hydrogen-containing silicone oil, 8-12 parts of modified nano-silicon dioxide, 10-20 parts of hexanediol diacrylate, and 2-4 parts of a photoinitiator;

[0006] In the preparation process of the modified hydrogenated silicone oil, the hydrogenated silicone oil, octavinylsilsesquioxane, a catalyst, a polymerization inhibitor and an organic solvent are mixed in an inert gas atmosphere, reacted, and the organic solvent is removed to obtain the modified hydrogenated silicone oil.

[0007] Preferably, in the preparation process of the modified hydrogen-containing silicone oil, the catalyst is a platinum catalyst.

[0008] The platinum catalyst is a Custer catalyst, which can be purchased from the market.

[0009] Preferably, in the preparation process of the modified hydrogen-containing silicone oil, the polymerization inhibitor is 2,6-di-tert-butylphenol.

[0010] Preferably, in the preparation process of the modified hydrogen-containing silicone oil, the organic solvent is toluene.

[0011] Preferably, in the preparation process of the modified hydrogen-containing silicone oil, the mass fraction of active hydrogen in the hydrogen-containing silicone oil is 0.2-0.3 wt %.

[0012] Preferably, during the preparation of the modified hydrogen-containing silicone oil, the reaction is carried out at 75-85° C. for 4-5 hours.

[0013] Preferably, in the preparation process of the modified hydrogenated silicone oil, the weight ratio of the hydrogenated silicone oil to octavinylsilsesquioxane is 1:0.75-0.8.

[0014] Preferably, in the preparation process of the modified hydrogen-containing silicone oil, the weight ratio of the hydrogen-containing silicone oil to the catalyst is 1:5-10 ppm.

[0015] Preferably, in the preparation process of the modified hydrogen-containing silicone oil, the weight ratio of the hydrogen-containing silicone oil to the polymerization inhibitor is 1:0.001-0.003.

[0016] Preferably, in the preparation process of hyperbranched polyurethane acrylate, in an inert gas atmosphere, diisocyanate, diol, pentaerythritol triacrylate, and a catalyst are mixed and reacted, and then a terminal hydroxyl hyperbranched polyester solution is added, the reaction is continued, and the solvent is removed to obtain hyperbranched polyurethane acrylate.

[0017] Preferably, in the preparation process of the hyperbranched polyurethane acrylate, the diisocyanate is at least one of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate and hexamethylene diisocyanate.

[0018] Preferably, in the preparation process of the hyperbranched polyurethane acrylate, the diol is at least one of polyethylene glycol and polypropylene glycol.

[0019] Preferably, in the preparation process of hyperbranched polyurethane acrylate, the catalyst is an organotin.

[0020] Preferably, in the preparation process of the hyperbranched polyurethane acrylate, the molecular weight of the terminal hydroxyl hyperbranched polyester is 400-600, and the number of hydroxyl groups of the terminal hydroxyl hyperbranched polyester is 5-7 mol.

[0021] The hydroxyl number of the above-mentioned hydroxyl-terminated hyperbranched polyester refers to the number of hydroxyl groups (—OH) contained at each molecular end.

[0022] The above-mentioned hydroxyl-terminated hyperbranched polyester can be purchased from the market, such as hydroxyl-terminated hyperbranched polyester HyPer H101.

[0023] Preferably, in the preparation process of the hyperbranched polyurethane acrylate, the molar ratio of diisocyanate, diol and pentaerythritol triacrylate is 1:0.35-0.4:0.3-0.4.

[0024] Preferably, in the preparation process of the hyperbranched polyurethane acrylate, the molar ratio of diisocyanate to terminal hydroxyl hyperbranched polyester is 1:0.14-0.18.

[0025] Preferably, in the preparation process of the hyperbranched polyurethane acrylate, the molar ratio of diisocyanate to catalyst is 1:0.001-0.002.

[0026] Preferably, in the preparation process of the hyperbranched polyurethane acrylate, the reaction is carried out at 40-50° C. for 2-3 hours.

[0027] Preferably, during the preparation of the hyperbranched polyurethane acrylate, the reaction is continued at 40-50° C. for 2-3 hours.

[0028] Preferably, in the preparation process of the hyperbranched polyurethane acrylate, the solvent of the hydroxyl-terminated hyperbranched polyester solution is acetone.

[0029] Preferably, the modified nano-silica is nano-silica grafted with unsaturated double bonds.

[0030] The modified nano-silica can be obtained by grafting and modifying a silane coupling agent containing an unsaturated double bond, and the silane coupling agent containing an unsaturated double bond can be γ-methacryloxypropyltrimethoxysilane or the like.

[0031] The present invention also provides a method for preparing the wear-resistant UV-curing polyacrylate coating, which comprises the following steps: mixing various raw materials under light-proof conditions to obtain the wear-resistant UV-curing polyacrylate coating.

[0032] The photoinitiator is stored separately from other raw materials and is mixed with other raw materials when used.

[0033] The photoinitiator may be 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylacetone, or the like.

[0034] The present invention also proposes the application of the wear-resistant UV-curing polyacrylate coating in photovoltaic cells.

[0035] The invention selects octavinyl silsesquioxane to react with hydrogen-containing silicone oil, and introduces carbon-carbon double bonds and cage-type silsesquioxane into the hydrogen-containing silicone oil; selects diisocyanate, diol, pentaerythritol triacrylate and terminal hydroxyl hyperbranched polyester to react to prepare hyperbranched polyurethane acrylate, and introduces carbon-carbon double bonds into the hyperbranched structure; the long chain of hydrogen-containing silicone oil can be interspersed in the hyperbranched structure, so that the two are uniformly dispersed and the fluidity of the coating is improved, the processing operation is convenient, and the amount of nano silicon dioxide is reduced; the nano silicon dioxide is grafted with unsaturated double bonds, so that the nano silicon dioxide and the hyperbranched polyurethane acrylate can be uniformly dispersed, and can participate in UV curing cross-linking, so that no use occurs during storage. The problem of easy precipitation of inorganic fillers; when cross-linked with hexanediol diacrylate by UV curing, on the one hand, the hyperbranched structure and the long chains of hydrogenated silicone oil interspersed therein can greatly increase the cross-linking density, thereby improving the toughness and wear resistance of the coating, and the hyperbranched polyurethane acrylate contains multiple active groups, which can improve the adhesion of the coating; on the other hand, the Si-O chains of the modified hydroxyl silicone oil are evenly interspersed in the cross-linked network, and the cage-type silsesquioxane and nano-silica are evenly distributed in the cross-linked network, which can greatly improve the hardness and wear resistance of the coating, and the introduction of hydroxyl silicone oil and cage-type silsesquioxane does not reduce the transmittance of the coating, so that the coating has both high transmittance and good wear resistance. DETAILED DESCRIPTION

[0036] The technical solution of the present invention is described in detail below through specific embodiments.

[0037] Example 1

[0038] A wear-resistant UV-curable polyacrylate coating, the raw materials of which include, by weight: 55 parts of hyperbranched polyurethane acrylate, 15 parts of modified hydrogen-containing silicone oil, 10 parts of γ-methacryloxypropyltrimethoxysilane-modified nano-silicon dioxide, 20 parts of hexanediol diacrylate, and 2 parts of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide;

[0039] In the preparation process of the modified hydrogen-containing silicone oil, under nitrogen protection, 0.2wt% of hydrogen-containing silicone oil, octavinyl silsesquioxane, platinum catalyst (Cast catalyst KP32), and 2,6-di-tert-butylphenol are added to toluene in a weight ratio of 1:0.75:5ppm:0.001, and the mixture is evenly mixed. The mixture is heated to 85°C and stirred for 4h, filtered, and the toluene is removed by evaporation under reduced pressure to obtain a clear and transparent modified hydrogen-containing silicone oil.

[0040] In the preparation process of hyperbranched polyurethane acrylate, toluene diisocyanate, polyethylene glycol 1000, pentaerythritol triacrylate, and dibutyltin dilaurate are mixed in a molar ratio of 1:0.35:0.4:0.001 under nitrogen protection, heated to 50° C. and stirred for reaction for 2 hours, and then an acetone solution of terminal hydroxyl hyperbranched polyester HyPer H101 with a solid content of 30wt% (the molecular weight of the terminal hydroxyl hyperbranched polyester HyPer H101 is 500, and the number of hydroxyl groups of the terminal hydroxyl hyperbranched polyester is 6 mol) is added to make the molar ratio of toluene diisocyanate and terminal hydroxyl hyperbranched polyester 1:0.18, and the reaction is continued at 50° C. for 2 hours, and the acetone is removed by reduced pressure evaporation to obtain clear and transparent hyperbranched polyurethane acrylate.

[0041] Example 2

[0042] A wear-resistant UV-curable polyacrylate coating, the raw materials of which include, by weight: 60 parts of hyperbranched polyurethane acrylate, 20 parts of modified hydrogen-containing silicone oil, 10 parts of γ-methacryloxypropyltrimethoxysilane-modified nano-silica, 10 parts of hexanediol diacrylate, and 4 parts of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide;

[0043] In the preparation process of the modified hydrogen-containing silicone oil, under nitrogen protection, 0.3wt% of hydrogen-containing silicone oil, octavinyl silsesquioxane, platinum catalyst (Cast catalyst KP32), and 2,6-di-tert-butylphenol are added to toluene in a weight ratio of 1:0.8:10ppm:0.003, and the mixture is evenly mixed, the mixture is heated to 75°C and stirred for reaction for 5h, filtered, and the toluene is removed by evaporation under reduced pressure to obtain a clear and transparent modified hydrogen-containing silicone oil;

[0044] In the preparation process of hyperbranched polyurethane acrylate, under nitrogen protection, hexamethylene diisocyanate, polypropylene glycol 1000, pentaerythritol triacrylate, and dibutyltin dilaurate are mixed in a molar ratio of 1:0.4:0.3:0.002, heated to 40° C. and stirred for reaction for 3 hours, and then an acetone solution of a 30wt% solid content of a terminal hydroxyl hyperbranched polyester HyPer H101 (the molecular weight of the terminal hydroxyl hyperbranched polyester HyPer H101 is 500, and the number of hydroxyl groups of the terminal hydroxyl hyperbranched polyester is 6 mol) is added to make the molar ratio of hexamethylene diisocyanate to the terminal hydroxyl hyperbranched polyester be 1:0.15, and the reaction is continued at 40° C. for 3 hours, and the acetone is removed by reduced pressure evaporation to obtain a clear and transparent hyperbranched polyurethane acrylate.

[0045] Example 3

[0046] A wear-resistant UV-curable polyacrylate coating, the raw materials of which include, by weight: 60 parts of hyperbranched polyurethane acrylate, 20 parts of modified hydrogen-containing silicone oil, 8 parts of γ-methacryloxypropyltrimethoxysilane-modified nano-silicon dioxide, 12 parts of hexanediol diacrylate, and 3 parts of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide;

[0047] In the preparation process of the modified hydrogen-containing silicone oil, under nitrogen protection, 0.3wt% of hydrogen-containing silicone oil, octavinyl silsesquioxane, platinum catalyst (Cast catalyst KP32), and 2,6-di-tert-butylphenol are added to toluene in a weight ratio of 1:0.8:7ppm:0.002, and the mixture is heated to 80°C and stirred for 4.5h, filtered, and toluene is removed by evaporation under reduced pressure to obtain a clear and transparent modified hydrogen-containing silicone oil;

[0048] In the preparation process of hyperbranched polyurethane acrylate, under nitrogen protection, isophorone diisocyanate, polyethylene glycol 1000, pentaerythritol triacrylate, and dibutyltin dilaurate are mixed in a molar ratio of 1:0.4:0.4:0.001, heated to 45° C. and stirred for reaction for 2.5 hours, and then an acetone solution of terminal hydroxyl hyperbranched polyester HyPer H101 with a solid content of 30wt% is added (the molecular weight of the terminal hydroxyl hyperbranched polyester HyPer H101 is 500, and the number of hydroxyl groups of the terminal hydroxyl hyperbranched polyester is 6 mol) so that the molar ratio of isophorone diisocyanate to the terminal hydroxyl hyperbranched polyester is 1:0.14, and the reaction is continued at 45° C. for 2.5 hours, and the acetone is removed by reduced pressure evaporation to obtain clear and transparent hyperbranched polyurethane acrylate.

[0049] Comparative Example 1

[0050] A wear-resistant UV-curable polyacrylate coating, wherein "hyperbranched polyurethane acrylate" is replaced with "ordinary polyurethane acrylate resin", and the rest is the same as Example 3.

[0051] Comparative Example 2

[0052] A wear-resistant UV-curable polyacrylate coating, wherein "modified hydrogen-containing silicone oil" is replaced by "hydrogen-containing silicone oil", and the rest is the same as Example 3.

[0053] Comparative Example 3

[0054] A wear-resistant UV-curable polyacrylate coating, wherein "60 parts of hyperbranched polyurethane acrylate and 25 parts of modified hydrogen-containing silicone oil" are replaced with "85 parts of hyperbranched polyurethane acrylate", and the rest is the same as Example 3.

[0055] Comparative Example 4

[0056] A wear-resistant UV-curable polyacrylate coating, wherein "60 parts of hyperbranched polyurethane acrylate and 25 parts of modified hydrogen-containing silicone oil" are replaced with "85 parts of modified hydrogen-containing silicone oil", and the rest is the same as Example 3.

[0057] Comparative Example 5

[0058] A wear-resistant UV-curing polyacrylate coating, wherein "25 parts of modified hydrogen-containing silicone oil" is replaced with "silicon dioxide with a particle size of 5 μm", and the rest is the same as Example 3.

[0059] The raw materials of Examples 1-3 and Comparative Examples 1-5 were mixed under light-proof conditions to obtain coatings, and coatings of the same thickness were prepared in the same manner (cured by ultraviolet light for 5 minutes), and the hardness, wear resistance, toughness, and adhesion of the coatings of each group were tested. The results are shown in Table 1.

[0060] The hardness is tested according to GB / T 6739-2022, the wear resistance is tested according to GB / T1768-2006, and the adhesion is tested according to GB / T9286-2021.

[0061] Table 1 Test results

[0062]

[0063]

[0064] It can be seen from Table 1 that the coating of the present invention has good hardness, wear resistance, transmittance and adhesion.

[0065] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A wear-resistant UV-curable polyacrylate coating, characterized in that: The raw materials include, by weight: 55-60 parts of hyperbranched polyurethane acrylate, 15-20 parts of modified hydrogen-containing silicone oil, 8-12 parts of modified nano silicon dioxide, 10-20 parts of hexanediol diacrylate, and 2-4 parts of photoinitiator; In the preparation process of the modified hydrogenated silicone oil, the hydrogenated silicone oil, octavinylsilsesquioxane, a catalyst, a polymerization inhibitor and an organic solvent are mixed in an inert gas atmosphere, reacted, and the organic solvent is removed to obtain the modified hydrogenated silicone oil.

2. The wear-resistant UV-curable polyacrylate coating according to claim 1, characterized in that: In the preparation process of the modified hydrogen-containing silicone oil, the catalyst is a platinum catalyst; preferably, in the preparation process of the modified hydrogen-containing silicone oil, the inhibitor is 2,6-di-tert-butylphenol; preferably, in the preparation process of the modified hydrogen-containing silicone oil, the organic solvent is toluene.

3. The wear-resistant UV-curable polyacrylate coating according to claim 1 or 2, characterized in that: In the preparation process of the modified hydrogen-containing silicone oil, the mass fraction of active hydrogen in the hydrogen-containing silicone oil is 0.2-0.3wt%; preferably, in the preparation process of the modified hydrogen-containing silicone oil, the reaction is carried out at 75-85°C for 4-5h.

4. The wear-resistant UV-curable polyacrylate coating according to any one of claims 1 to 3, characterized in that: In the preparation process of the modified hydrogen-containing silicone oil, the weight ratio of hydrogen-containing silicone oil to octavinylsilsesquioxane is 1:0.75-0.8; preferably, in the preparation process of the modified hydrogen-containing silicone oil, the weight ratio of hydrogen-containing silicone oil to catalyst is 1:5-10ppm; preferably, in the preparation process of the modified hydrogen-containing silicone oil, the weight ratio of hydrogen-containing silicone oil to inhibitor is 1:0.001-0.

003.

5. The wear-resistant UV-curable polyacrylate coating according to any one of claims 1 to 4, characterized in that: In the preparation process of hyperbranched polyurethane acrylate, diisocyanate, diol, pentaerythritol triacrylate and catalyst are mixed in an inert gas atmosphere to react, and then a terminal hydroxyl hyperbranched polyester solution is added to continue the reaction, and the solvent is removed to obtain hyperbranched polyurethane acrylate.

6. The wear-resistant UV-curable polyacrylate coating according to any one of claims 1 to 6, characterized in that: In the preparation process of hyperbranched polyurethane acrylate, the diisocyanate is at least one of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate; preferably, in the preparation process of hyperbranched polyurethane acrylate, the diol is at least one of polyethylene glycol and polypropylene glycol; preferably, in the preparation process of hyperbranched polyurethane acrylate, the catalyst is organic tin.

7. The wear-resistant UV-curable polyacrylate coating according to any one of claims 1 to 6, characterized in that: In the preparation process of hyperbranched polyurethane acrylate, the molecular weight of the terminal hydroxyl hyperbranched polyester is 400-600, and the number of hydroxyl groups of the terminal hydroxyl hyperbranched polyester is 5-7 mol; preferably, in the preparation process of hyperbranched polyurethane acrylate, the molar ratio of diisocyanate, diol and pentaerythritol triacrylate is 1:0.35-0.4:0.3-0.4; preferably, in the preparation process of hyperbranched polyurethane acrylate, the molar ratio of diisocyanate and terminal hydroxyl hyperbranched polyester is 1:0.14 -0.18; preferably, in the preparation process of hyperbranched polyurethane acrylate, the molar ratio of diisocyanate to catalyst is 1:0.001-0.002; preferably, in the preparation process of hyperbranched polyurethane acrylate, the reaction is carried out at 40-50°C for 2-3h; preferably, in the preparation process of hyperbranched polyurethane acrylate, the reaction is continued at 40-50°C for 2-3h; preferably, in the preparation process of hyperbranched polyurethane acrylate, the solvent of the terminal hydroxyl hyperbranched polyester solution is acetone.

8. The wear-resistant UV-curable polyacrylate coating according to any one of claims 1 to 7, characterized in that: The modified nano-silica is nano-silica grafted with unsaturated double bonds.

9. A method for preparing the wear-resistant UV-curable polyacrylate coating according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: mixing various raw materials evenly under light-proof conditions to obtain a wear-resistant UV-curing polyacrylate coating.

10. Use of the wear-resistant UV-curable polyacrylate coating according to any one of claims 1 to 8 in photovoltaic cells.

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