Preparation method of a high-strength light-emitting transparent coating

Abstract

The present invention relates to the technical field of coatings, and discloses a preparation method of a high-strength luminous transparent coating. In the present invention, modified polyurethane, epoxidized methyl silicate pentaerythritol ester, high-gloss transparent polyurethane emulsion, propylene glycol film-forming aid, polysiloxane defoamer, zinc sulfide pigment, ammonium acrylate wetting agent, and water are mixed and stirred. After stirring evenly, it is allowed to stand at room temperature to obtain a high-strength luminous transparent coating. During the stirring process, the terminal hydroxyl groups in the modified polyurethane will undergo a ring-opening reaction with the epoxy groups in the epoxidized methyl silicate pentaerythritol ester, increasing the compatibility between them. At the same time, crosslinking occurs between them to form a crosslinked network, increasing its mechanical properties; the quaternary ammonium salt groups and imidazole groups in the modified polyurethane have good antibacterial effects. The silicon element, sulfur element, and sodium sulfonate groups in the modified polyurethane and methyl silicate pentaerythritol ester have good flame retardant effects and jointly constitute a flame retardant system.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and specifically to a preparation method of a high-strength luminous transparent coating. Background Art

[0002] A high-strength luminous transparent coating is a coating with special functions. It can emit bright light while maintaining transparency. This coating is usually made of specific materials, such as fluorescent pigments, photoluminescent materials, or other substances that can absorb and re-emit light. For example, Patent CN105152546B discloses a transparent anti-fouling coating material for glass, a transparent anti-fouling coating and its preparation method. The hydrophobic coating material and its preparation method provided by this invention require few equipment, the raw materials are non-toxic, the use cost is low, and the preparation of a large-area transparent anti-fouling coating can be carried out; the obtained coating has excellent hydrophobicity, transparency, anti-fouling property and repeated wiping property; however, its flame retardant and antibacterial effects have not been improved. Summary of the Invention

[0003] (1) Technical Problems to be Solved

[0004] In view of the deficiencies of the prior art, the present invention provides a preparation method of a high-strength luminous transparent coating, which has good flame retardant, tensile and antibacterial effects.

[0005] (2) Technical Solutions

[0006] To achieve the above object, the present invention provides the following technical solutions: A preparation method of a high-strength luminous transparent coating, and the preparation method of the high-strength luminous transparent coating is as follows:

[0007] (1) Add diallylbisphenol A to N,N-dimethylformamide solvent, stir and disperse, then add mercaptosuccinic acid and benzoin dimethyl ether photoinitiator thereto, irradiate with ultraviolet light of 365 nm at 30 - 50 °C for 3 - 4 h, after completion, centrifuge, wash and dry to obtain Intermediate 1;

[0008] (2) Add Intermediate 1 and 1-(2-hydroxyethyl)imidazole to N,N-dimethylformamide solvent, stir to dissolve, continue to add p-toluenesulfonic acid catalyst, carry out an esterification reaction at 75 - 100 °C, the reaction time is 6 - 8 h, after completion, carry out vacuum distillation, wash and dry to obtain Intermediate 2;

[0009] (3) Add Intermediate 2 and 3-chloro-2-hydroxypropylsulfonate to an aqueous sodium hydroxide solution with a mass fraction of 5 - 7%, carry out a quaternization reaction, react at 40 - 65 °C for 6 - 8 h, after the reaction, cool, add dilute hydrochloric acid dropwise to adjust the pH to 7, and then evaporate to obtain an imidazole-based chain extender;

[0010] (4) After dehydrating the polyether diol, mix it evenly with hexamethylene diisocyanate, introduce nitrogen, then dropwise add dibutyltin dilaurate catalyst, and react at 55 - 80 °C for 2 - 4 h for prepolymerization. Then add an imidazole-based chain extender and stir to continue the chain extension reaction, reacting at 40 - 60 °C for 1 - 2 h. After the reaction is completed, cool and discharge to obtain the modified polyurethane;

[0011] (5) Add magnolol, pentaerythritol methyl silicate, and adipoyl chloride to the N,N-dimethylacetamide solvent, stir and mix. Then continue to add pyridine catalyst and react at 60 - 80 °C for 1 - 3 h to obtain the modified magnolol after the reaction ends;

[0012] (6) Add 3 - 6 parts by weight of the modified magnolol to the acetone solvent, stir evenly, then add 10 - 14 parts by weight of aqueous hydrogen peroxide solution and react. After the reaction ends, perform vacuum distillation, filter and dry to obtain epoxidized pentaerythritol methyl silicate.

[0013] (7) Mix 8 - 12 parts by weight of the modified polyurethane, 6 - 10 parts by weight of epoxidized pentaerythritol methyl silicate, 12 - 15 parts by weight of high-gloss transparent polyurethane emulsion, 1 - 2 parts by weight of propylene glycol film-forming aid, 0.2 - 0.3 parts by weight of polysiloxane defoamer, 1 - 2 parts by weight of zinc sulfide pigment, 0.3 - 0.5 parts by weight of ammonium acrylate wetting agent, and 10 - 14 parts by weight of water and stir. After stirring evenly, let it stand at room temperature for 3 - 5 h to obtain the high-strength luminous transparent coating.

[0014] Preferably, in the (1), the mass ratio of diallyl bisphenol A, mercaptosuccinic acid, and benzoin dimethyl ether photoinitiator is 1:1.3 - 1.5:0.01 - 0.03.

[0015] Preferably, in the (2), the mass ratio of intermediate 1, 1-(2-hydroxyethyl)imidazole, and p-toluenesulfonic acid catalyst is 1:1.1 - 1.3:0.02 - 0.03.

[0016] Preferably, in the (3), the mass ratio of intermediate 2 and 3-chloro-2-hydroxypropanesulfonate is 1:1.2 - 1.4.

[0017] Preferably, in the (4), the mass ratio of polyether diol, hexamethylene diisocyanate, dibutyltin dilaurate catalyst, and imidazole-based chain extender is 1.2 - 1.5:1:0.01 - 0.02:0.4 - 0.7.

[0018] Preferably, in the (5), the mass ratio of magnolol, pentaerythritol methyl silicate, adipoyl chloride, and pyridine catalyst is 1:1.6 - 1.8:0.8 - 1.2:0.01 - 0.03.

[0019] Preferably, the reaction temperature in (6) is 30 - 45°C.

[0020] Preferably, the reaction time in (6) is 4 - 7 h.

[0021] (III) Beneficial technical effects

[0022] In the present invention, a high-strength light-emitting transparent coating is obtained by mixing and stirring modified polyurethane, epoxidized pentaerythritol methyl silicate, high-gloss transparent polyurethane emulsion, propylene glycol film-forming aid, polysiloxane defoamer, zinc sulfide pigment, ammonium acrylate wetting agent, and water, and then standing at room temperature after stirring evenly.

[0023] During the stirring process, the terminal hydroxyl groups in the modified polyurethane will undergo a ring-opening reaction with the epoxy groups in the epoxidized pentaerythritol methyl silicate, increasing the compatibility between them. At the same time, crosslinking occurs between them to form a crosslinked network, enhancing its mechanical properties; the quaternary ammonium salt groups and imidazole groups in the modified polyurethane have good antibacterial effects, and intermediate 1 reacts with 1-(2-hydroxyethyl)imidazole to increase the substitution degree of imidazole, making its antibacterial effect better. The silicon element, sulfur element, and sodium sulfonate groups in the modified polyurethane and pentaerythritol methyl silicate have good flame retardant effects and jointly constitute a flame retardant system. Specific embodiments

[0024] Example 1

[0025] (1) Diallylbisphenol A is added to N,N-dimethylformamide solvent and stirred for dispersion. Then, mercaptosuccinic acid and benzoin dimethyl ether photoinitiator are added thereto. The mass ratio of diallylbisphenol A, mercaptosuccinic acid, and benzoin dimethyl ether photoinitiator is 1:1.3:0.01. Under ultraviolet light irradiation at 365 nm for 3 h at 30°C, after completion, centrifugation separation, washing, and drying are carried out to obtain intermediate 1;

[0026] (2) Intermediate 1 and 1-(2-hydroxyethyl)imidazole are added to N,N-dimethylformamide solvent and stirred for dissolution. Then, p-toluenesulfonic acid catalyst is continuously added. The mass ratio of intermediate 1, 1-(2-hydroxyethyl)imidazole, and p-toluenesulfonic acid catalyst is 1:1.1:0.02. Esterification reaction is carried out at 75°C for 6 h. After completion, distillation under reduced pressure, washing, and drying are carried out to obtain intermediate 2;

[0027] (3) Intermediate 2 and 3-chloro-2-hydroxypropylsulfonate sodium are added to a 5% sodium hydroxide aqueous solution. The mass ratio of intermediate 2 and 3-chloro-2-hydroxypropylsulfonate sodium is 1:1.2. The reaction is carried out at 40°C for 6 h. After the reaction, it is cooled, and dilute hydrochloric acid is added dropwise to adjust the pH to 7, and then evaporation is carried out to obtain an imidazole-based chain extender;

[0028] (4) After dehydrating the polyether diol, it is mixed evenly with hexamethylene diisocyanate, nitrogen is introduced, and then dibutyltin dilaurate catalyst is added dropwise. The reaction is carried out at 55 °C for 2 h for prepolymerization, and then an imidazole-based chain extender is added. The mass ratio of polyether diol, hexamethylene diisocyanate, dibutyltin dilaurate catalyst, and imidazole-based chain extender is 1.2:1:0.01:0.4. Stirring continues for chain extension reaction, and the reaction is carried out at 40 °C for 1 h. After the reaction is completed, it is cooled and discharged to obtain the modified polyurethane;

[0029] (5) Add magnolol, pentaerythritol methyl silicate, and adipoyl chloride to the N,N-dimethylacetamide solvent, stir and mix, and continue to add pyridine catalyst to it. The mass ratio of magnolol, pentaerythritol methyl silicate, adipoyl chloride, and pyridine catalyst is 1:1.6:0.8:0.01. The reaction is carried out at 60 °C for 1 h, and after completion, the modified magnolol is obtained;

[0030] (6) Add 3 parts by weight of the modified magnolol to the acetone solvent, stir evenly, and then add 10 parts by weight of hydrogen peroxide aqueous solution. The reaction is carried out at 30 °C for 4 h. After completion, it is distilled under reduced pressure, filtered and dried to obtain epoxidized pentaerythritol methyl silicate;

[0031] (7) Mix 8 parts by weight of the modified polyurethane, 6 parts by weight of epoxidized pentaerythritol methyl silicate, 12 parts by weight of high-gloss transparent polyurethane emulsion, 1 part by weight of propylene glycol film-forming aid, 0.2 part by weight of polysiloxane defoamer, 1 part by weight of zinc sulfide pigment, 0.3 part by weight of ammonium acrylate wetting agent, and 10 parts by weight of water by stirring. After stirring evenly, let it stand at room temperature for 3 h to obtain the high-strength luminous transparent coating.

[0032] Example 2

[0033] (1) Add diallyl bisphenol A to the N,N-dimethylformamide solvent, stir and disperse, and then add mercaptosuccinic acid and benzoin dimethyl ether photoinitiator to it. The mass ratio of diallyl bisphenol A, mercaptosuccinic acid, and benzoin dimethyl ether photoinitiator is 1:1.5:0.03. Under ultraviolet light irradiation at 365 nm at 50 °C for 4 h, after completion, centrifuge, wash and dry to obtain Intermediate 1;

[0034] (2) Add Intermediate 1 and 1-(2-hydroxyethyl)imidazole to the N,N-dimethylformamide solvent, stir and dissolve, and continue to add p-toluenesulfonic acid catalyst. The mass ratio of Intermediate 1, 1-(2-hydroxyethyl)imidazole, and p-toluenesulfonic acid catalyst is 1:1.3:0.03. The esterification reaction is carried out at 100 °C for 8 h. After completion, distill under reduced pressure, wash and dry to obtain Intermediate 2;

[0035] (3) Add intermediate 2 and sodium 3-chloro-2-hydroxypropanesulfonate to an aqueous sodium hydroxide solution with a mass fraction of 7%, where the mass ratio of intermediate 2 to sodium 3-chloro-2-hydroxypropanesulfonate is 1:1.4. React at 65 °C for 8 h. After the reaction, cool, add dilute hydrochloric acid dropwise to adjust the pH to 7, and then evaporate to obtain an imidazole-based chain extender;

[0036] (4) After dehydrating the polyether diol, mix it evenly with hexamethylene diisocyanate, introduce nitrogen, and then add dibutyltin dilaurate catalyst dropwise. React at 80 °C for 4 h for prepolymerization, and then add the imidazole-based chain extender. The mass ratio of polyether diol, hexamethylene diisocyanate, dibutyltin dilaurate catalyst, and imidazole-based chain extender is 1.5:1:0.02:0.7. Stir to continue the chain extension reaction and react at 60 °C for 2 h. After the reaction is completed, cool and discharge to obtain a modified polyurethane;

[0037] (5) Add magnolol, pentaerythritol methyl silicate, and adipoyl chloride to an N,N-dimethylacetamide solvent, stir and mix, and then continue to add pyridine catalyst. The mass ratio of magnolol, pentaerythritol methyl silicate, adipoyl chloride, and pyridine catalyst is 1:1.8:1.2:0.03. React at 80 °C for 3 h, and after completion, obtain modified magnolol;

[0038] (6) Add 6 parts by weight of modified magnolol to an acetone solvent, stir evenly, and then add 14 parts by weight of an aqueous hydrogen peroxide solution. React at 45 °C for 7 h. After completion, perform vacuum distillation, filter, and dry to obtain epoxidized pentaerythritol methyl silicate;

[0039] (7) Mix and stir 12 parts by weight of the modified polyurethane, 10 parts by weight of the epoxidized pentaerythritol methyl silicate, 15 parts by weight of a high-gloss transparent polyurethane emulsion, 2 parts by weight of a propylene glycol film-forming aid, 0.3 parts by weight of a polysiloxane defoamer, 2 parts by weight of zinc sulfide pigment, 0.5 parts by weight of an ammonium acrylate wetting agent, and 14 parts by weight of water. After stirring evenly, let it stand at room temperature for 5 h to obtain a high-strength light-emitting transparent coating.

[0040] Example 3

[0041] (1) Add diallylbisphenol A to an N,N-dimethylformamide solvent, stir and disperse, and then add mercaptosuccinic acid and benzoin dimethyl ether photoinitiator. The mass ratio of diallylbisphenol A, mercaptosuccinic acid, and benzoin dimethyl ether photoinitiator is 1:1.4:0.02. Under ultraviolet light irradiation at 365 nm at 40 °C for 3 h, after completion, perform centrifugal separation, washing, and drying to obtain intermediate 1;

[0042] (2) Add intermediate 1 and 1-(2-hydroxyethyl)imidazole into N,N-dimethylformamide solvent, stir to dissolve, and then continue to add p-toluenesulfonic acid catalyst. The mass ratio of intermediate 1, 1-(2-hydroxyethyl)imidazole, and p-toluenesulfonic acid catalyst is 1:1.2:0.03. Carry out the esterification reaction at 100 °C for 6 h. After completion, perform vacuum distillation, wash, and dry to obtain intermediate 2;

[0043] (3) Add intermediate 2 and sodium 3-chloro-2-hydroxypropanesulfonate into an aqueous sodium hydroxide solution with a mass fraction of 6%. The mass ratio of intermediate 2 and sodium 3-chloro-2-hydroxypropanesulfonate is 1:1.3. React at 55 °C for 7 h. After the reaction, cool, add dilute hydrochloric acid dropwise to adjust the pH to 7, and then evaporate to obtain the imidazole-based chain extender;

[0044] (4) After dehydrating the polyether diol, mix it evenly with hexamethylene diisocyanate, introduce nitrogen, and then add dibutyltin dilaurate catalyst dropwise. React at 65 °C for 3 h for prepolymerization, and then add the imidazole-based chain extender. The mass ratio of polyether diol, hexamethylene diisocyanate, dibutyltin dilaurate catalyst, and imidazole-based chain extender is 1.4:1:0.01:0.6. Stir to continue the chain extension reaction and react at 50 °C for 1 h. After the reaction is completed, cool and discharge to obtain the modified polyurethane;

[0045] (5) Add magnolol, pentaerythritol methyl silicate, and adipoyl chloride into N,N-dimethylacetamide solvent, stir and mix, and then continue to add pyridine catalyst. The mass ratio of magnolol, pentaerythritol methyl silicate, adipoyl chloride, and pyridine catalyst is 1:1.7:1.0:0.02. React at 70 °C for 2 h. After completion, obtain the modified magnolol;

[0046] (6) Add 5 parts by weight of the modified magnolol into acetone solvent, stir evenly, and then add 12 parts by weight of hydrogen peroxide aqueous solution. React at 35 °C for 6 h. After completion, perform vacuum distillation, filter, and dry to obtain epoxidized pentaerythritol methyl silicate;

[0047] (7) Mix 10 parts by weight of the modified polyurethane, 8 parts by weight of the epoxidized pentaerythritol methyl silicate, 14 parts by weight of the high-gloss transparent polyurethane emulsion, 1 part by weight of the propylene glycol film-forming aid, 0.3 part by weight of the polysiloxane defoamer, 1 part by weight of the zinc sulfide pigment, 0.4 part by weight of the ammonium acrylate wetting agent, and 12 parts by weight of water and stir. After stirring evenly, let it stand at room temperature for 4 h to obtain the high-strength luminous transparent coating.

[0048] Comparative Example 1

[0049] The difference between this comparative example and Example 3 is that the modified polyurethane is not added.

[0050] Comparative Example 2

[0051] Compared with Example 3, the difference in this comparative example is that epoxidized pentaerythritol methyl silicate was not added.

[0052] The limiting oxygen index of the coating was tested using an oxygen index meter; the combustion grade of the coating was tested using a horizontal and vertical burning tester.

[0053] Table 1: Flame retardancy test.

[0054] Project Limiting oxygen index (%) Combustion rating Example 1 30 V-0 Example 2 32 V-0 Example 3 31 V-0 Comparative example 1 20 V-1 Comparative example 2 21 V-1

[0055] As can be seen from Table 1, Examples 1 - 3 have better flame retardancy than Comparative Examples 1 - 2, indicating that the coating prepared by the present invention has good flame retardancy.

[0056] The mechanical properties of the coating were tested using a universal electronic testing machine, and the tensile rate was 100 mm / min.

[0057] Table 2: Tensile strength test.

[0058]

[0059]

[0060] As can be seen from Table 2, Examples 1 - 3 have better tensile properties than Comparative Examples 1 - 2, and the coating prepared by the present invention has good tensile strength.

[0061] Antibacterial performance: The coating was carefully torn and cut into circular pieces with a diameter of 10 mm, sterilized with a UV lamp, added to 10 mL of solid agar medium, and cultured with Staphylococcus aureus (10 μL, 106 CFU / mL) in an incubator at 37°C for 12 hours. The experiment was carried out with three parallel controls and the average value was taken. The blank control was carried out without the coating, and then CFU counting was measured. The calculation formula for the antibacterial rate is shown as follows: Antibacterial rate (%) = (1 - C / N) × 100%. Where N is the average number of viable bacteria in the blank control group after 12 hours, and C is the average number of viable bacteria in the experimental group after 12 hours. The test results are shown in Table 2.

[0062] Table 3: Antibacterial rate test.

[0063] Project Antibacterial rate (%) Example 1 96.5 Example 2 99.6 Example 3 98.8 Comparative example 1 72.1 Comparative example 2 83.2

[0064] As can be seen from Table 3, Examples 1 - 3 of the present invention have better antibacterial properties than Comparative Examples 1 - 2.

[0065] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A preparation method of a high-strength light-emitting transparent coating, characterized in that, The preparation method of the high-strength light-emitting transparent coating is as follows: (1) Add diallylbisphenol A to N,N-dimethylformamide solvent, stir and disperse it, then add mercaptosuccinic acid and benzoin dimethyl ether photoinitiator to it. Under 30-50 °C, irradiate it with ultraviolet light of 365 nm for 3-4 h. After completion, centrifuge, wash and dry to obtain intermediate 1; (2) Add intermediate 1 and 1-(2-hydroxyethyl)imidazole to N,N-dimethylformamide solvent, stir to dissolve, continue to add p-toluenesulfonic acid catalyst, and carry out an esterification reaction at 75-100 °C for 6-8 h. After completion, carry out vacuum distillation, wash and dry to obtain intermediate 2; (3) Add intermediate 2 and 3-chloro-2-hydroxypropylsulfonate sodium to an aqueous sodium hydroxide solution with a mass fraction of 5-7%, react at 40-65 °C for 6-8 h, cool after the reaction, add dilute hydrochloric acid dropwise to adjust the pH to 7, and then evaporate to obtain an imidazole-based chain extender; (4) After dehydrating the polyether diol, mix it evenly with hexamethylene diisocyanate, introduce nitrogen, then add dibutyltin dilaurate catalyst dropwise, react at 55-80 °C for 2-4 h for prepolymerization, then add the imidazole-based chain extender, stir to continue the chain extension reaction, react at 40-60 °C for 1-2 h. After the reaction is completed, cool and discharge to obtain a modified polyurethane; (5) Add magnolol, pentaerythritol methyl silicate, and adipoyl chloride to N,N-dimethylacetamide solvent, stir and mix, continue to add pyridine catalyst to it, react at 60-80 °C for 1-3 h, and obtain modified magnolol after completion; (6) Add 3-6 parts by weight of modified magnolol to acetone solvent, stir evenly, then add 10-14 parts by weight of hydrogen peroxide aqueous solution to it for reaction. After completion, carry out vacuum distillation, filter and dry to obtain epoxidized pentaerythritol methyl silicate; (7) Mix 8-12 parts by weight of the modified polyurethane, 6-10 parts by weight of the epoxidized pentaerythritol methyl silicate, 12-15 parts by weight of the high-gloss transparent polyurethane emulsion, 1-2 parts by weight of the propylene glycol film-forming aid, 1-2 parts by weight of the zinc sulfide pigment, 0.2-0.3 parts by weight of the polysiloxane defoamer, 0.3-0.5 parts by weight of the ammonium acrylate wetting agent, and 10-14 parts by weight of water and stir. After stirring evenly, let it stand at room temperature for 3-5 h to obtain the high-strength light-emitting transparent coating.

2. The preparation method of the high-strength light-emitting transparent coating according to claim 1, wherein In the above (1), the mass ratio of diallylbisphenol A, mercaptosuccinic acid, and benzoin dimethyl ether photoinitiator is 1:1.3-1.5:0.01-0.

03.

3. The preparation method of the high-strength light-emitting transparent coating according to claim 1, characterized in that, In the above (2), the mass ratio of intermediate 1, 1-(2-hydroxyethyl)imidazole, and p-toluenesulfonic acid catalyst is 1:1.1-1.3:0.02-0.

03.

4. The preparation method of the high-strength light-emitting transparent coating according to claim 1, characterized in that, In the above (3), the mass ratio of intermediate 2 and 3-chloro-2-hydroxypropylsulfonate sodium is 1:1.2-1.

4.

5. The preparation method of the high-strength light-emitting transparent coating according to claim 1, characterized in that, In the above (4), the mass ratio of polyether diol, hexamethylene diisocyanate, dibutyltin dilaurate catalyst, and imidazole-based chain extender is 1.2-1.5:1:0.01-0.02:0.4-0.

7.

6. The preparation method of the high-strength light-emitting transparent coating according to claim 1, wherein In the above (5), the mass ratio of magnolol, pentaerythritol methyl silicate, adipoyl chloride, and pyridine catalyst is 1:1.6 - 1.8:0.8 - 1.2:0.01 - 0.

03.

7. The preparation method of the high-strength light-emitting transparent coating according to claim 1, characterized in that In the above (6), the reaction temperature is 30 - 45 °C.

8. The preparation method of the high-strength light-emitting transparent coating according to claim 1, wherein In the above (6), the reaction time is 4 - 7 h.

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