An ultraviolet light-cured superhydrophobic self-cleaning polyurethane acrylate and a method of manufacturing the same

Abstract

The application belongs to the field of resin synthesis and relates to a kind of ultraviolet light curing super-hydrophobic self-cleaning polyurethane acrylate and its manufacturing method.The manufacturing method of the ultraviolet light curing resin specifically includes the following steps: (1) adding perfluorosilane, water and solvent into a reaction bottle and stirring, hydrolyzing into perfluorosilanol at room temperature, and distilling organic solvent under reduced pressure; (2) adding diisocyanate, catalyst and organosilicon dihydric alcohol to obtain an intermediate product; (3) adding monohydroxy acrylate and polymerization inhibitor to obtain the ultraviolet light curing super-hydrophobic self-cleaning polyurethane acrylate diluted by acrylate active diluent diluent.The application uses organosilicon dihydric alcohol as the main chain of the ultraviolet light curing resin, introduces a large number of high-energy C-F bonds on the main chain, and the molecular structure is extremely stable, the surface energy is reduced, and the ultraviolet light curing resin with super-hydrophobic and self-cleaning properties is manufactured.

Description

Technical Field

[0001] This invention relates to a UV-curable superhydrophobic self-cleaning polyurethane acrylate and its manufacturing method, belonging to the field of resin synthesis. Background Technology

[0002] Superhydrophobic materials, resembling the surface of a lotus leaf, possess inherent natural properties such as waterproofing, moisture resistance, salt spray resistance, mildew resistance, dust resistance, corrosion resistance, and short-circuit protection due to their unique repulsive characteristics towards water or water vapor. Inspired by the lotus leaf in nature, a biomimetic superhydrophobic coating technology has attracted widespread attention. A coating with a water droplet contact angle greater than 150° and a roll-off angle less than 10° is called a superhydrophobic coating. The surface of a superhydrophobic coating has a rough micro / nano structure and low surface energy. Based on the "cushion effect" and "self-cleaning effect," water on its surface can condense into droplets, reducing the contact area between corrosive liquids and the coating, and the residence time of corrosive substances on the coating surface, thus achieving superhydrophobic and self-cleaning effects. Summary of the Invention

[0003] This invention relates to a UV-curable superhydrophobic self-cleaning polyurethane acrylate and its manufacturing method, which has the following advantages and innovations compared with the prior art: This invention utilizes an organosilicon diol as the main chain of a UV-curable resin, introducing a large number of high-bond-energy CF bonds into the main chain, resulting in an extremely stable molecular structure and significantly reduced surface energy. This produces a UV-curable resin with superhydrophobic and self-cleaning properties. UV-curable coatings prepared using this resin can be used not only for coating various common boards but also for coating building materials requiring high weather resistance, such as metal coils, aluminum profiles, aluminum composite panels, and exterior wall decorative panels, to obtain a protective coating with superhydrophobic and self-cleaning properties.

[0004] The resin synthesis process referred to in this invention includes the following reaction steps: (1) Add perfluorosilane, water and solvent to a reaction flask and stir. Hydrolyze to perfluorosilanol at room temperature. Distill off the organic solvent and excess water under reduced pressure. (2) Add diisocyanate and organosilicon diol, stir and heat to 50-80 degrees for 2 hours, add catalyst and react for 3-5 hours. The content of NCO groups in the system is basically stable by acetone-di-n-butylamine method, and the intermediate product is obtained. (3) Add monohydroxy acrylate and polymerization inhibitor, stir and heat to 70-80 degrees Celsius for 5 hours, and use the acetone-di-n-butylamine method to track and detect the NCO group content in the system. When the content is less than 0.3%, stop the reaction to obtain UV-cured superhydrophobic self-cleaning polyurethane acrylate.

[0005] The perfluorosilanes mentioned above are any one of perfluorooctyltrimethoxysilane, perfluorooctyltriethoxysilane, dodecylfluoroalkyltrimethoxysilane, dodecylfluoroalkyltriethoxysilane, tridecylfluoroalkyltrimethoxysilane, tridecylfluoroalkyltriethoxysilane, and heptadecafluoroalkyltrimethoxysilane.

[0006] To ensure complete hydrolysis, water must be in excess. The molar ratio is selected to be 1:1.5 to 1:3. Hydrolysis yields a trihydroxy perfluorosilanol.

[0007] The organic solvents mentioned above include methanol, ethanol, isopropanol, acetone, etc.

[0008] The diisocyanates mentioned above are toluene-2,4-diisocyanate (TDI), isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (HMDI), hexamethylene diisocyanate (HDI), etc. To obtain relatively low viscosity and prepare a stable resin, diisocyanates with significantly different activities of the two isocyanate groups are preferred, with toluene-2,4-diisocyanate (TDI) and isophorone diisocyanate (IPDI) being the most preferred. To obtain better weather resistance in the resin, isophorone diisocyanate (IPDI) is preferred.

[0009] The organosilicon diols mentioned above are polysiloxane copolymers with hydroxyl-terminated ends, and there are different products with number average molecular weights of 1000, 2000, and 3000.

[0010] The molar ratio of the perfluorosilane, diisocyanate, organosilicon diol, and monohydroxy acrylate described above is 1:6:3:3.2. Monohydroxy acrylate is in excess to ensure complete reaction of the isocyanate. Finally, a polyurethane acrylate with the structure perfluorosilane-(diisocyanate-organosilicon diol-diisocyanate-monohydroxy acrylate)3 is obtained.

[0011] The monohydroxy acrylates mentioned above are selected from hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, trimethylolpropane diacrylate, and pentaerythritol triacrylate. End-capping with monofunctional hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxybutyl acrylate yields trifunctional UV-curable superhydrophobic self-cleaning polyurethane acrylates; end-capping with trifunctional pentaerythritol triacrylate yields nonfunctional UV-curable superhydrophobic self-cleaning polyurethane acrylates. High-functionality polyurethane acrylates can be used to prepare more robust coatings, and blends of different high-functionality polyurethane acrylates can be used to prepare coatings of various hardnesses.

[0012] The above-mentioned polymerization inhibitors include p-hydroxyanisole and 2,6-di-tert-butyl-p-cresol, or one or a mixture thereof.

[0013] The amount of polymerization inhibitor added as described above is 0.2%-1% of the acrylate monomer.

[0014] The catalysts described above are selected from one of the organotin or organobismuth catalysts, such as dibutyltin dilaurate and bismuth isooctanoate.

[0015] The catalyst added as described above is 0.02-0.1% of the total amount of reactants.

[0016] Detailed implementation method.

[0017] Example 1: (1) Add 51 g of 0.1 mol perfluorooctyltriethoxysilane, 10.8 g of 0.6 mol water and 100 mL of ethanol to a reaction flask and stir. Hydrolyze at room temperature to perfluorosilanol. Distill off the organic solvent and excess water under reduced pressure. (2) Add 133.2 g of 0.6 mol isophorone diisocyanate and 300 g of 0.3 mol organosilicon diol with a molecular weight of 1000, stir and heat to 50-80 degrees for 2 hours, add 0.3 g of catalyst and react for 3-5 hours. The content of NCO groups in the system is basically stable by acetone-di-n-butylamine method, and the intermediate product is obtained. (3) Add 41.76 g of 0.36 mol hydroxyethyl acrylate and 0.3 g of polymerization inhibitor, stir and heat to 70-80 degrees for 5 hours, and use the acetone-di-n-butylamine method to track and detect the NCO group content in the system. Stop the reaction when the content is less than 0.3% to obtain trifunctional UV-cured superhydrophobic self-cleaning polyurethane acrylate.

[0018] Example 2: (1) Add 51 g of 0.1 mol perfluorooctyltriethoxysilane, 10.8 g of 0.6 mol water and 100 mL of ethanol to a reaction flask and stir. Hydrolyze at room temperature to perfluorosilanol. Distill off the organic solvent and excess water under reduced pressure. (2) Add 133.2 g of 0.6 mol isophorone diisocyanate and 300 g of 0.3 mol organosilicon diol with a molecular weight of 1000, stir and heat to 50-80 degrees for 2 hours, add 0.3 g of catalyst and react for 3-5 hours. The content of NCO groups in the system is basically stable by acetone-di-n-butylamine method, and the intermediate product is obtained. (3) Add 107.28 g of 0.36 mol pentaerythritol triacrylate and 0.3 g of polymerization inhibitor, stir and heat to 70-80 degrees for 5 hours, and use the acetone-di-n-butylamine method to track and detect the NCO group content in the system. Stop the reaction when the content is less than 0.3% to obtain a nine-functional UV-curable superhydrophobic self-cleaning polyurethane acrylate.

[0019] Example 3: (1) Add 51 g of 0.1 mol perfluorooctyltriethoxysilane, 10.8 g of 0.6 mol water and 100 mL of ethanol to a reaction flask and stir. Hydrolyze at room temperature to perfluorosilanol. Distill off the organic solvent and excess water under reduced pressure. (2) Add 133.2 g of 0.6 mol isophorone diisocyanate and 600 g of 0.3 mol organosilicon diol with a molecular weight of 2000, stir and heat to 50-80 degrees for 2 hours, add 0.3 g of catalyst and react for 3-5 hours. The content of NCO groups in the system is basically stable by acetone-di-n-butylamine method, and the intermediate product is obtained. (3) Add 41.76 g of 0.36 mol hydroxyethyl acrylate and 0.3 g of polymerization inhibitor, stir and heat to 70-80 degrees for 5 hours, and use the acetone-di-n-butylamine method to track and detect the NCO group content in the system. Stop the reaction when the content is less than 0.3% to obtain trifunctional UV-cured superhydrophobic self-cleaning polyurethane acrylate.

[0020] Example 4: (1) Add 51 g of 0.1 mol perfluorooctyltriethoxysilane, 10.8 g of 0.6 mol water and 100 mL of ethanol to a reaction flask and stir. Hydrolyze at room temperature to perfluorosilanol. Distill off the organic solvent and excess water under reduced pressure. (2) Add 133.2 g of 0.6 mol isophorone diisocyanate and 600 g of 0.3 mol organosilicon diol with a molecular weight of 2000, stir and heat to 50-80 degrees for 2 hours, add 0.3 g of catalyst and react for 3-5 hours. The content of NCO groups in the system is basically stable by acetone-di-n-butylamine method, and the intermediate product is obtained. (3) Add 107.28 g of 0.36 mol pentaerythritol triacrylate and 0.3 g of polymerization inhibitor, stir and heat to 70-80 degrees for 5 hours, and use the acetone-di-n-butylamine method to track and detect the NCO group content in the system. Stop the reaction when the content is less than 0.3% to obtain a nine-functional UV-curable superhydrophobic self-cleaning polyurethane acrylate.

[0021] The UV-curable superhydrophobic self-cleaning polyurethane acrylate obtained from the above-synthesized examples was UV-cured under specified conditions, and relevant performance tests were conducted. The test results are as follows: Example Resin Adhesion (Grade) Water droplet contact angle Resistance to artificial weathering (2000h) Salt spray resistance (2000h) Example 1 1 157° No change No change Example 2 1 159° No change No change Example 3 1 153° No change No change Example 4 1 151° No change No change Test methods GB / T9286-2021 GB / T 24368-2009 GB1865-1997 GB / T1771-1991 .

[0022] The embodiments described herein are merely preferred embodiments of the invention and are not intended to limit the concept and scope of the invention. Any modifications and improvements made by those skilled in the art to the technical solutions of the invention without departing from the design concept of the invention should fall within the protection scope of the invention. The technical content for which protection is sought in this invention has been fully described in the claims.

Claims

1. The present invention relates to a UV-cured superhydrophobic self-cleaning polyurethane acrylate, characterized in that: The synthesis process includes the following reaction steps: (1) Add perfluorosilane, water and solvent to a reaction flask and stir. Hydrolyze to perfluorosilanol at room temperature. Distill off the organic solvent and excess water under reduced pressure. (2) Add diisocyanate and organosilicon diol, stir and heat to 50-80 degrees for 2 hours, add catalyst and react for 3-5 hours. The content of NCO groups in the system is basically stable by acetone-di-n-butylamine method, and the intermediate product is obtained. (3) Add monohydroxy acrylate and polymerization inhibitor, stir and heat to 70-80 degrees Celsius for 5 hours, and use the acetone-di-n-butylamine method to track and detect the NCO group content in the system. When the content is less than 0.3%, stop the reaction to obtain UV-cured superhydrophobic self-cleaning polyurethane acrylate.

2. As described in claim 1, characterized in that The perfluorosilane is any one of perfluorooctyltrimethoxysilane, perfluorooctyltriethoxysilane, dodecylfluoroalkyltrimethoxysilane, dodecylfluoroalkyltriethoxysilane, tridecylfluoroalkyltrimethoxysilane, tridecylfluoroalkyltriethoxysilane, and heptadecafluoroalkyltrimethoxysilane.

3. According to claim 1, the characteristic is that The organic solvents used are methanol, ethanol, isopropanol, acetone, etc.

4. As described in claim 1, characterized in that The diisocyanate mentioned is toluene-2,4-diisocyanate (TDI), isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (HMDI), hexamethylene diisocyanate (HDI), etc.

5. According to claim 1, the characteristic is that The organosilicon diol is a polysiloxane copolymer with hydroxyalkyl ends and a number average molecular weight of 1000, 2000, 3000, etc.

6. As described in claim 1, characterized in that The monohydroxy acrylate is selected from hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, trimethylolpropane diacrylate, and pentaerythritol triacrylate.

7. As described in claim 1, characterized in that The polymerization inhibitor is one or a mixture of p-hydroxyanisole and 2,6-di-tert-butyl-p-cresol.

8. The feature of claim 1, wherein... The catalyst is selected from one of the organotin or organobismuth catalysts, such as dibutyltin dilaurate and bismuth isooctanoate.