Synthetic resin emulsion paint for interior and exterior walls having good alkali resistance and a method for producing the same

Abstract

This invention relates to the field of coating technology and discloses a synthetic resin emulsion paint for interior and exterior walls with good alkali resistance and its preparation method. The invention involves adding modified polyurethane, modified vanillin, dispersant, synthetic resin emulsion, defoamer, leveling agent, and water to a mixer and stirring until homogeneous. The resulting synthetic resin emulsion paint for interior and exterior walls exhibits good alkali resistance. During the mixing process, the hydroxyl groups in the modified vanillin react with the terminal isocyanates in the modified polyurethane to form urethane, increasing interfacial compatibility. Furthermore, the branches become entangled, forming an interpenetrating network that can withstand most of the energy under external force, thus improving the paint's wear resistance. The large amount of sulfonic acid groups not only provides good alkali resistance but also exhibits good flame retardancy, synergistically enhancing flame retardancy with silicon and phosphorus elements.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to a synthetic resin emulsion paint for interior and exterior walls with good alkali resistance and its preparation method. Background Technology

[0002] Coatings are applied to the surface of objects that need protection and form a continuous film that adheres firmly to the object. They are usually based on resins, oils, or emulsions. However, long-term exposure to air can cause surface peeling and reduced alkali resistance. How to avoid this phenomenon is the key to solving the problem. For example, the literature "Preparation and Performance Study of Vanillin-based Epoxy Resin" reported the synthesis of vanillin Schiff base curing agent by vanillin modification and dehydration condensation reaction of 4,4-diaminodiphenylmethane. Inspired by this, flame-retardant groups were further introduced on this basis to achieve the purpose of flame retardancy. Summary of the Invention

[0003] (a) Technical problems to be solved

[0004] To address the shortcomings of existing technologies, this invention provides a synthetic resin emulsion paint for interior and exterior walls with good alkali resistance and its preparation method, exhibiting good alkali resistance and flame retardancy.

[0005] (II) Technical Solution

[0006] To achieve the above objectives, the present invention provides the following technical solution: a synthetic resin emulsion paint for interior and exterior walls with good alkali resistance, comprising the following weight components: 6-8 parts by weight of modified polyurethane, 3-5 parts by weight of modified vanillin, 1-2 parts by weight of dispersant, 20-40 parts by weight of synthetic resin emulsion, 2-3 parts by weight of defoamer, 0.8-2 parts by weight of leveling agent, and 10-20 parts by weight of water;

[0007] The dispersant is sodium polyacrylate;

[0008] The synthetic resin emulsion is a copolymer of styrene and acrylic acid;

[0009] The defoamer is silica;

[0010] The leveling agent is butyl acrylate.

[0011] Preferably, the method for preparing the modified polyurethane includes the following steps:

[0012] (1) Add 1,3-propanesulfonyl lactone and 4,4-diaminodiphenylmethane to acetone solvent, stir evenly, and then continue to add sodium hydroxide solution with a mass fraction of 4-5%. React at 70-100℃ for 7-10h. After the reaction is completed, remove the solvent by vacuum distillation and recrystallize from ethanol to obtain intermediate 1.

[0013] (2) Add intermediate 1 and sodium 3-chloro-2-hydroxypropanesulfonate to N,N-dimethylformamide, stir, continue to add triethylamine catalyst, react at 2-5℃ for 1-2 h, after which distill under reduced pressure, filter, wash and dry to obtain sulfonic acid chain extender.

[0014] (3) Add hexamethylene diisocyanate and polyether polyol to the reactor, then add dibutyltin dilaurate catalyst, purge with nitrogen, and react at 60-80℃ for 3-6h. Continue to add sulfonic acid chain extender and react at 50-80℃ for 4-8h. After the reaction is completed, cool to room temperature and discharge to obtain modified polyurethane.

[0015] Preferably, the mass ratio of 1,3-propanesulfonyl lactone and 4,4-diaminodiphenylmethane in (1) is 1:1.1-1.3.

[0016] Preferably, the mass ratio of intermediate 1, sodium 3-chloro-2-hydroxypropanesulfonate, and triethylamine catalyst in (2) is 1:1.2-1.5:0.02-0.03.

[0017] Preferably, the mass ratio of hexamethylene diisocyanate, polyether polyol, dibutyltin dilaurate catalyst, and sulfonic acid chain extender in (3) is 1.3-1.6:1:0.01-0.02:0.8-1.

[0018] Preferably, the method for preparing the modified vanillin includes the following steps:

[0019] S1. Add 4,4-diaminodiphenylmethane to ethanol solvent, stir and dissolve at room temperature, then add vanillin dissolved in ethanol solvent under constant pressure, react at 50-70℃ for 6-8h, cool to room temperature after reaction, remove solvent by rotary evaporation, recrystallize, filter and dry to obtain olefin vanillin.

[0020] S2. Add olefin vanillin, diethyl phosphite, and hexamethyldisilazane to N,N-dimethylformamide solvent, react at 60-90℃ for 7-10 h, distill under reduced pressure after reaction, wash and dry to obtain modified vanillin.

[0021] Preferably, the mass ratio of 4,4-diaminodiphenylmethane to vanillin in S1 is 1.1-1.4:1.

[0022] Preferably, the mass ratio of vanillin, diethyl phosphite, and hexamethyldisilazane in S2 is 1:0.7-0.9:0.5-1.

[0023] Preferably, the preparation method of the synthetic resin emulsion paint for interior and exterior walls with good alkali resistance includes the following steps: adding modified polyurethane, modified vanillin, dispersant, synthetic resin emulsion, defoamer, leveling agent, and water into a stirrer, stirring evenly at a stirring speed of 300-400 r / min for 20-40 min, and obtaining the synthetic resin emulsion paint for interior and exterior walls with good alkali resistance.

[0024] (III) Beneficial Technical Effects

[0025] This invention involves adding modified polyurethane, modified vanillin, dispersant, synthetic resin emulsion, defoamer, leveling agent, and water to a mixer and stirring until homogeneous. The result is a synthetic resin emulsion paint for interior and exterior walls with good alkali resistance.

[0026] During the mixing process, the hydroxyl groups in the modified vanillin react with the terminal isocyanates in the modified polyurethane to form urethane, which increases the interfacial compatibility between them. The branches also become entangled, forming an interpenetrating network. When subjected to external forces, it can withstand most of the energy, thus improving the wear resistance of the coating. The large number of sulfonic acid groups and the positive and negative charge centers formed by the adjacent carbon atoms, as well as the electrostatic attraction and repulsion, give the sulfonic acid groups not only good alkali resistance but also good flame retardancy, and synergistically enhance the flame retardancy with silicon and phosphorus elements. Detailed Implementation

[0027] The dispersant is sodium polyacrylate;

[0028] The synthetic resin emulsion is a copolymer of styrene and acrylic acid;

[0029] The defoamer is silica;

[0030] The leveling agent is butyl acrylate.

[0031] Example 1

[0032] (1) Add 1,3-propanesulfonyl lactone and 4,4-diaminodiphenylmethane to acetone solvent, wherein the mass ratio of 1,3-propanesulfonyl lactone and 4,4-diaminodiphenylmethane is 1:1.1. Stir until homogeneous, then add 4% sodium hydroxide solution by mass and react at 70°C for 7 hours. After the reaction is completed, remove the solvent by vacuum distillation and recrystallize from ethanol to obtain intermediate 1.

[0033] (2) Intermediate 1 and sodium 3-chloro-2-hydroxypropanesulfonate were added to N,N-dimethylformamide and stirred. Triethylamine catalyst was then added. The mass ratio of intermediate 1, sodium 3-chloro-2-hydroxypropanesulfonate and triethylamine catalyst was 1:1.2:0.02. The reaction was carried out at 2°C for 1 h. After the reaction was completed, the mixture was distilled under reduced pressure, filtered, washed and dried to obtain a chain extender containing sulfonic acid groups.

[0034] (3) Hexamethylene diisocyanate and polyether polyol were added to a reaction vessel, and then dibutyltin dilaurate catalyst was added. The mass ratio of hexamethylene diisocyanate, polyether polyol, dibutyltin dilaurate catalyst and sulfonic acid chain extender was 1.3:1:0.01:0.8. Nitrogen gas was introduced for protection, and the reaction was carried out at 60°C for 3 hours. Sulfonic acid chain extender was added, and the reaction was carried out at 50°C for 4 hours. After the reaction was completed, the mixture was cooled to room temperature and discharged to obtain modified polyurethane.

[0035] (4) Add 4,4-diaminodiphenylmethane to the ethanol solvent, stir and dissolve at room temperature, then add vanillin dissolved in the ethanol solvent under constant pressure, wherein the mass ratio of 4,4-diaminodiphenylmethane to vanillin is 1.1:1, react at 50°C for 6 hours, cool to room temperature after the reaction, remove the solvent by rotary evaporation, recrystallize, filter and dry to obtain olefin vanillin;

[0036] (5) Add olefin vanillin, diethyl phosphite and hexamethyldisilazane to N,N-dimethylformamide solvent, wherein the mass ratio of olefin vanillin, diethyl phosphite and hexamethyldisilazane is 1:0.7:0.5. React at 60℃ for 7h. After the reaction is completed, distill under reduced pressure, wash and dry to obtain modified vanillin.

[0037] (6) Add 6 parts by weight of modified polyurethane, 3 parts by weight of modified vanillin, 1 part by weight of dispersant, 20 parts by weight of synthetic resin emulsion, 2 parts by weight of defoamer, 0.8 parts by weight of leveling agent and 10 parts by weight of water to a mixer, stir evenly, stir at 300 r / min for 20 min, and after the stirring is completed, a synthetic resin emulsion paint for interior and exterior walls with good alkali resistance is obtained.

[0038] Example 2

[0039] (1) Add 1,3-propanesulfonyl lactone and 4,4-diaminodiphenylmethane to acetone solvent, wherein the mass ratio of 1,3-propanesulfonyl lactone and 4,4-diaminodiphenylmethane is 1:1.3. Stir evenly, then continue to add 5% sodium hydroxide solution by mass, and react at 100℃ for 10h. After the reaction is completed, remove the solvent by vacuum distillation, and recrystallize from ethanol to obtain intermediate 1.

[0040] (2) Intermediate 1 and sodium 3-chloro-2-hydroxypropanesulfonate were added to N,N-dimethylformamide and stirred. Triethylamine catalyst was added, wherein the mass ratio of intermediate 1, sodium 3-chloro-2-hydroxypropanesulfonate and triethylamine catalyst was 1:1.5:0.03. The reaction was carried out at 5°C for 2 hours. After the reaction was completed, the mixture was distilled under reduced pressure, filtered, washed and dried to obtain a chain extender containing sulfonic acid groups.

[0041] (3) Hexamethylene diisocyanate and polyether polyol were added to a reaction vessel, and then dibutyltin dilaurate catalyst was added. The mass ratio of hexamethylene diisocyanate, polyether polyol, dibutyltin dilaurate catalyst and sulfonic acid chain extender was 1.6:1:0.02:1. Nitrogen gas was introduced for protection, and the reaction was carried out at 80°C for 6 hours. Sulfonic acid chain extender was added, and the reaction was carried out at 80°C for 8 hours. After the reaction was completed, the mixture was cooled to room temperature and discharged to obtain modified polyurethane.

[0042] (4) Add 4,4-diaminodiphenylmethane to the ethanol solvent, stir and dissolve at room temperature, then add vanillin dissolved in the ethanol solvent under constant pressure, wherein the mass ratio of 4,4-diaminodiphenylmethane to vanillin is 1.4:1, react at 70℃ for 8 hours, cool to room temperature after the reaction, remove the solvent by rotary evaporation, recrystallize, filter and dry to obtain olefin vanillin;

[0043] (5) Add olefin vanillin, diethyl phosphite and hexamethyldisilazane to N,N-dimethylformamide solvent, wherein the mass ratio of olefin vanillin, diethyl phosphite and hexamethyldisilazane is 1:0.9:1. React at 90℃ for 10h. After the reaction is completed, distill under reduced pressure, wash and dry to obtain modified vanillin.

[0044] (6) Add 8 parts by weight of modified polyurethane, 5 parts by weight of modified vanillin, 2 parts by weight of dispersant, 40 parts by weight of synthetic resin emulsion, 3 parts by weight of defoamer, 2 parts by weight of leveling agent and 20 parts by weight of water to a mixer, stir evenly, stir at 400 r / min for 40 min, and after the stirring is completed, a synthetic resin emulsion paint for interior and exterior walls with good alkali resistance is obtained.

[0045] Example 3

[0046] (1) Add 1,3-propanesulfonyl lactone and 4,4-diaminodiphenylmethane to acetone solvent, wherein the mass ratio of 1,3-propanesulfonyl lactone and 4,4-diaminodiphenylmethane is 1:1.2. Stir until homogeneous, and then continue to add sodium hydroxide solution with a mass fraction of 4.5%. React at 85°C for 8.5 h. After the reaction is completed, remove the solvent by vacuum distillation and recrystallize from ethanol to obtain intermediate 1.

[0047] (2) Intermediate 1 and sodium 3-chloro-2-hydroxypropanesulfonate were added to N,N-dimethylformamide and stirred. Triethylamine catalyst was then added. The mass ratio of intermediate 1, sodium 3-chloro-2-hydroxypropanesulfonate and triethylamine catalyst was 1:1.35:0.05. The reaction was carried out at 3.5℃ for 1.5 h. After the reaction was completed, the mixture was distilled under reduced pressure, filtered, washed and dried to obtain a chain extender containing sulfonic acid groups.

[0048] (3) Hexamethylene diisocyanate and polyether polyol were added to a reaction vessel, and then dibutyltin dilaurate catalyst was added. The mass ratio of hexamethylene diisocyanate, polyether polyol, dibutyltin dilaurate catalyst and sulfonic acid chain extender was 1.45:1:0.015:0.9. Nitrogen gas was introduced for protection, and the reaction was carried out at 70°C for 4.5 h. Sulfonic acid chain extender was added, and the reaction was carried out at 65°C for 6 h. After the reaction was completed, the mixture was cooled to room temperature and discharged to obtain modified polyurethane.

[0049] (4) Add 4,4-diaminodiphenylmethane to the ethanol solvent, stir and dissolve at room temperature, then add vanillin dissolved in the ethanol solvent under constant pressure, wherein the mass ratio of 4,4-diaminodiphenylmethane to vanillin is 1.25:1, react at 60℃ for 7h, cool to room temperature after the reaction, remove the solvent by rotary evaporation, recrystallize, filter and dry to obtain olefin vanillin;

[0050] (5) Add olefin vanillin, diethyl phosphite and hexamethyldisilazane to N,N-dimethylformamide solvent, wherein the mass ratio of olefin vanillin, diethyl phosphite and hexamethyldisilazane is 1:0.8:0.75, react at 75℃ for 8.5 h, after which vacuum distillation is performed, and the product is washed and dried to obtain modified vanillin.

[0051] (6) Add 7 parts by weight of modified polyurethane, 4 parts by weight of modified vanillin, 1.5 parts by weight of dispersant, 30 parts by weight of synthetic resin emulsion, 2.5 parts by weight of defoamer, 1.4 parts by weight of leveling agent and 15 parts by weight of water to a mixer, stir evenly, stir at 350 r / min for 30 min, and after the stirring is completed, a synthetic resin emulsion paint for interior and exterior walls with good alkali resistance is obtained.

[0052] Comparative Example 1

[0053] The difference between this comparative example and Example 3 is that no modified polyurethane was added.

[0054] Comparative Example 2

[0055] The difference between this comparative example and Example 3 is that no modified vanillin was added.

[0056] The synthetic resin emulsion paints for interior and exterior walls with good alkali resistance prepared in the above examples and comparative examples were subjected to alkali resistance tests.

[0057] Table 1: Alkali resistance test.

[0058] project Alkali resistance Example 1 No abnormalities Example 2 No abnormalities Example 3 No abnormalities Comparative Example 1 Mild loss of light Comparative Example 2 Mild loss of light

[0059] As shown in Table 1, the synthetic resin emulsion paints for interior and exterior walls prepared in Examples 1-3 of the present invention have better alkali resistance than the synthetic resin emulsion paints for interior and exterior walls prepared in Comparative Examples 1-2.

[0060] The limiting oxygen index of water-based paints was tested using an oxygen index meter; the flammability rating of water-based paints was tested using a horizontal and vertical burner.

[0061] Table 2: Flame retardancy test.

[0062] project Limiting oxygen index (%) flammability rating Example 1 28 V-0 Example 2 32 V-0 Example 3 31 V-0 Comparative Example 1 21 V-1 Comparative Example 2 20 V-1

[0063] As shown in Table 2, the synthetic resin emulsion paints for interior and exterior walls prepared in Examples 1-3 of the present invention have better flame retardant effects compared with the synthetic resin emulsion paints for interior and exterior walls prepared in Comparative Examples 1-2, which have good alkali resistance.

[0064] Abrasion resistance was tested according to GB / T 23988-2009 "Determination of Abrasion Resistance of Coatings - Falling Sand Method".

[0065] Table 3: Abrasion resistance test.

[0066] project Abrasion resistance (L / um) Example 1 3.17 Example 2 3.22 Example 3 3.21 Comparative Example 1 1.65 Comparative Example 2 1.63

[0067] As shown in Table 2, the synthetic resin emulsion paints for interior and exterior walls prepared in Examples 1-3 of the present invention have better wear resistance than the synthetic resin emulsion paints for interior and exterior walls prepared in Comparative Examples 1-2.

[0068] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A synthetic resin emulsion paint for interior and exterior walls with good alkali resistance, characterized in that, It includes the following components by weight: 6-8 parts by weight of modified polyurethane, 3-5 parts by weight of modified vanillin, 1-2 parts by weight of dispersant, 20-40 parts by weight of synthetic resin emulsion, 2-3 parts by weight of defoamer, 0.8-2 parts by weight of leveling agent, and 10-20 parts by weight of water. The preparation method of the modified polyurethane includes the following steps: (1) Add 1,3-propanesulfonyl lactone and 4,4-diaminodiphenylmethane to acetone solvent, stir evenly, and then continue to add sodium hydroxide solution with a mass fraction of 4-5%. React at 70-100℃ for 7-10h. After the reaction is completed, remove the solvent by vacuum distillation and recrystallize from ethanol to obtain intermediate 1. (2) Add intermediate 1 and sodium 3-chloro-2-hydroxypropanesulfonate to N,N-dimethylformamide, stir, continue to add triethylamine catalyst, react at 2-5℃ for 1-2 h, after which distill under reduced pressure, filter, wash and dry to obtain sulfonic acid chain extender. (3) Add hexamethylene diisocyanate and polyether polyol to the reactor, then add dibutyltin dilaurate catalyst, purge with nitrogen for protection, and react at 60-80℃ for 3-6h. Continue to add sulfonic acid chain extender, and react at 50-80℃ for 4-8h. After the reaction is completed, cool to room temperature and discharge to obtain modified polyurethane. The preparation method of the modified vanillin includes the following steps: S1. Add 4,4-diaminodiphenylmethane to ethanol solvent, stir and dissolve at room temperature, then add vanillin dissolved in ethanol solvent under constant pressure, react at 50-70℃ for 6-8h, cool to room temperature after reaction, remove solvent by rotary evaporation, recrystallize, filter and dry to obtain olefin vanillin. S2. Add olefin vanillin, diethyl phosphite, and hexamethyldisilazane to N,N-dimethylformamide solvent, react at 60-90℃ for 7-10 h, distill under reduced pressure after reaction, wash and dry to obtain modified vanillin.

2. The synthetic resin emulsion paint for interior and exterior walls with good alkali resistance according to claim 1, characterized in that, The mass ratio of 1,3-propanesulfonyl lactone and 4,4-diaminodiphenylmethane in (1) is 1:1.1-1.

3.

3. The synthetic resin emulsion paint for interior and exterior walls with good alkali resistance according to claim 1, characterized in that, In (2), the mass ratio of intermediate 1, sodium 3-chloro-2-hydroxypropanesulfonate, and triethylamine catalyst is 1:1.2-1.5:0.02-0.

03.

4. The synthetic resin emulsion paint for interior and exterior walls with good alkali resistance according to claim 1, characterized in that, The mass ratio of hexamethylene diisocyanate, polyether polyol, dibutyltin dilaurate catalyst, and sulfonic acid chain extender in (3) is 1.3-1.6:1:0.01-0.02:0.8-1.

5. The synthetic resin emulsion paint for interior and exterior walls with good alkali resistance according to claim 1, characterized in that, The mass ratio of 4,4-diaminodiphenylmethane to vanillin in S1 is 1.1-1.4:

1.

6. The synthetic resin emulsion paint for interior and exterior walls with good alkali resistance according to claim 1, characterized in that, The mass ratio of vanillin, diethyl phosphite, and hexamethyldisilazane in S2 is 1:0.7-0.9:0.5-1.

7. A method for preparing a synthetic resin emulsion paint for interior and exterior walls with good alkali resistance as described in any one of claims 1-6, characterized in that, The preparation method of the synthetic resin emulsion paint for interior and exterior walls with good alkali resistance includes the following steps: adding modified polyurethane, modified vanillin, dispersant, synthetic resin emulsion, defoamer, leveling agent, and water into a stirrer, stirring evenly at a stirring speed of 300-400 r / min for 20-40 min, and obtaining the synthetic resin emulsion paint for interior and exterior walls with good alkali resistance.