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CN-120842918-B - Preparation method of EVA waterproof coating

CN120842918BCN 120842918 BCN120842918 BCN 120842918BCN-120842918-B

Abstract

The invention relates to the technical field of paint, and discloses a preparation method of EVA waterproof paint, wherein activated montmorillonite reacts with toluene diisocyanate to obtain isocyanate modified montmorillonite. EVA is hydrolyzed under the catalysis of potassium hydroxide to obtain hydroxylated EVA. The epoxy trisiloxane intermediate reacts with terephthalic acid under the ring-opening esterification of benzyl triethyl ammonium chloride to obtain the p-hydroxy trisiloxane benzoate. And (3) performing crosslinking reaction on the p-hydroxy trisiloxane benzoate, hydroxylated EVA, isocyanate modified montmorillonite and toluene diisocyanate under the catalysis of stannous octoate, adding a defoaming agent and a dispersing agent into the mixture, and uniformly stirring to obtain the EVA waterproof coating. The EVA waterproof coating prepared by the invention has good mechanical property and waterproof property.

Inventors

  • CHEN LIYUN

Assignees

  • 江苏梵品新材料有限公司

Dates

Publication Date
20260508
Application Date
20250120

Claims (7)

  1. 1. The preparation method of the EVA waterproof coating is characterized by comprising the following steps of: (1) Placing 1,3, 5-heptamethyltrisiloxane and allyl glycidyl ether in a molar ratio of 1:1.05 into isopropanol solution, adding an alcohol solution of chloroplatinic acid into the isopropanol solution under nitrogen atmosphere, reacting for 5 hours at 90 ℃, evaporating out a solvent, removing low-boiling substances in vacuum for 30 minutes at 85 ℃ and 60kPa, and cooling to room temperature to obtain an epoxy trisiloxane intermediate; (2) Placing the epoxy trisiloxane intermediate, terephthalic acid and benzyl triethylammonium chloride in 1, 2-dichloroethane, reacting for 2.5-4h at 75-90 ℃, cooling to room temperature, filtering under reduced pressure, recrystallizing, and drying to obtain the p-hydroxy trisiloxane benzoate; (3) Placing p-hydroxy trisiloxane benzoate, hydroxylated EVA, isocyanate modified montmorillonite, stannous octoate and tetrahydrofuran solvent into a flask, uniformly stirring, adding toluene diisocyanate into the mixture, heating the mixture to 60-70 ℃, reacting the mixture for 2-4 hours, cooling the mixture to room temperature, adding water into the mixture, distilling the mixture under reduced pressure to remove tetrahydrofuran, adding a defoaming agent and a dispersing agent, and uniformly stirring the mixture to obtain the EVA waterproof coating; The preparation method of the hydroxylated EVA in the step (3) comprises the following steps: placing EVA in toluene solution, adding isopropanol solution of potassium hydroxide at 50-70 ℃, stirring and reacting for 5-8h, precipitating with ethanol, filtering, washing with ethanol, and drying to obtain hydroxylated EVA; The preparation method of the isocyanate modified montmorillonite in the step (3) comprises the following steps: Under the protection of nitrogen, the activated montmorillonite and toluene diisocyanate are placed in a toluene solvent to be stirred and dispersed for 20-40min, the temperature is raised for reaction, the reaction product is cooled to room temperature, and the isocyanate modified montmorillonite is obtained through suction filtration, washing and vacuum drying.
  2. 2. The method for preparing EVA waterproof paint according to claim 1, wherein the mass ratio of the epoxy trisiloxane intermediate to terephthalic acid in the step (2) is 1:0.2-0.3.
  3. 3. The method for preparing EVA waterproof paint according to claim 1, wherein the benzyl triethyl ammonium chloride in the step (2) is used in an amount of 1-1.5% of the total mass of the epoxy trisiloxane intermediate and terephthalic acid.
  4. 4. The method for preparing EVA waterproof paint according to claim 1, wherein the mass ratio of the parahydroxy trisiloxane benzoate, the hydroxylated EVA, the isocyanate modified montmorillonite, the stannous octoate and the toluene diisocyanate in the step (3) is 5-30:100:0.5-8:0.02-0.12:3-20.
  5. 5. The method for preparing EVA waterproof paint according to claim 1, wherein the mass ratio of EVA to potassium hydroxide in the step (3) is 100:5-7.
  6. 6. The method for preparing EVA waterproof paint according to claim 1, wherein the mass ratio of the activated montmorillonite to the toluene diisocyanate in the step (3) is 1:0.2-0.5.
  7. 7. The method for preparing EVA waterproof paint according to claim 1, wherein the heating reaction time in the step (3) is 60-100min, and the temperature is 70-90 ℃.

Description

Preparation method of EVA waterproof coating The application relates to a divisional application of an application with the application number 202510086452.4 and the name of 'a preparation method of EVA waterproof coating' which is filed in 2024, 01 and 20 days. Technical Field The invention relates to the technical field of coatings, in particular to a preparation method of an EVA waterproof coating. Background Water, chloride ions and other harmful ions can enter the concrete and some materials with porous structures through gaps, so that the durability of the materials is affected, the maintenance cost of the materials is increased, and therefore, waterproof paint needs to be brushed on the surfaces of the materials, so that the materials have the properties of water resistance, wear resistance and the like, and the service time of the materials is prolonged. Therefore, research and development of new waterproof coatings is now the focus of research by researchers. EVA is an ethylene-vinyl acetate copolymer material, has excellent elasticity, flexibility, insulativity and chemical corrosion resistance, and is widely applied to the fields of wires and cables, films, adhesives, coatings and the like. Montmorillonite is a silicate natural mineral substance with a layer of aluminum oxide octahedron sandwiched between two layers of silicon oxygen tetrahedrons and negatively charged surface, and has better dispersibility, impact resistance and other properties. For example, patent application publication number CN113930169B discloses a heat-resistant EVA film and a preparation method thereof, and the film prepared by the method has better tensile strength, tear strength and wet heat resistance, but has poorer water resistance. Disclosure of Invention The invention solves the technical problem of providing a preparation method of EVA waterproof coating, and the prepared EVA waterproof coating has good mechanical property and waterproof property. The technical scheme of the invention is as follows: a preparation method of EVA waterproof paint comprises the following steps: (1) Placing the epoxy trisiloxane intermediate, terephthalic acid and benzyl triethylammonium chloride in 1, 2-dichloroethane, reacting for 2.5-4h at 75-90 ℃, cooling to room temperature, filtering under reduced pressure, recrystallizing, and drying to obtain the p-hydroxy trisiloxane benzoate; (2) Placing p-hydroxy trisiloxane benzoate, hydroxylated EVA, isocyanate modified montmorillonite, stannous octoate and tetrahydrofuran solvent into a flask, uniformly stirring, adding toluene diisocyanate into the flask, heating to 60-70 ℃, reacting for 2-4h, cooling to room temperature, adding water into the flask, distilling under reduced pressure to remove tetrahydrofuran, adding a defoaming agent and a dispersing agent, and uniformly stirring to obtain the EVA waterproof coating. Further, the mass ratio of the epoxy trisiloxane intermediate to the terephthalic acid in the step (1) is 1:0.2-0.3. Further, the amount of the benzyl triethyl ammonium chloride in the step (1) is 1 to 1.5 percent of the total mass of the epoxy trisiloxane intermediate and the terephthalic acid. Further, in the step (2), the mass ratio of the parahydroxy trisiloxane benzoate, the hydroxylated EVA, the isocyanate modified montmorillonite, the stannous octoate and the toluene diisocyanate is 5-30:100:0.5-8:0.02-0.12:3-20. Further, the preparation method of the hydroxylated EVA in the step (2) comprises the following steps: (3) Placing EVA in toluene solution, adding isopropanol solution of potassium hydroxide at 50-70 ℃, stirring and reacting for 5-8h, precipitating with ethanol, filtering, washing with ethanol, and drying to obtain hydroxylated EVA. Further, in the step (3), the mass ratio of EVA to potassium hydroxide is 100:5-7. Further, the preparation method of the isocyanate modified montmorillonite in the step (2) comprises the following steps: (4) Under the protection of nitrogen, the activated montmorillonite and toluene diisocyanate are placed in a toluene solvent to be stirred and dispersed for 20-40min, the temperature is raised for reaction, the reaction product is cooled to room temperature, and the isocyanate modified montmorillonite is obtained through suction filtration, washing and vacuum drying. Further, the mass ratio of the activated montmorillonite to the toluene diisocyanate in the step (4) is 1:0.2-0.5. Further, the temperature rise reaction time in the step (4) is 60-100min, and the temperature is 70-90 ℃. The beneficial technical effects of the invention are as follows: the activated montmorillonite reacts with toluene diisocyanate to obtain isocyanate modified montmorillonite. EVA is hydrolyzed under the catalysis of potassium hydroxide to obtain hydroxylated EVA. The epoxy trisiloxane intermediate reacts with terephthalic acid under the ring-opening esterification of benzyl triethyl ammonium chloride to obtain the p-hydroxy trisiloxane benzoate. A