An exposed high-temperature resistant oxygen-carbon modified waterproof coating

Abstract

The present invention relates to a kind of exposed high temperature resistant oxygen-carbon modified waterproof coating, belong to the technical field of coatings. The present invention first utilizes the amino group on aminosilane coupling agent and 1,3,5 triazine 2,4,6 triacyl chloride to react, obtain triazine silane coupling agent, then utilizes the diethoxysilane on triazine silane coupling agent and the hydroxyl on hydroxyethyl cellulose to react, hydroxyl is converted into hydrophobic and heat-resistant Si O C key, while utilizing the triazine ring with good thermal stability, effectively improves the heat-resistant and waterproof performance of hydroxyethyl cellulose. There are a large number of tertiary amino groups on modified cellulose, hydrogen bonds can be formed with the hydroxyl groups on the surfaces of kaolin, heavy calcium carbonate and rutile titanium dioxide in coating, improve the stability of kaolin, heavy calcium carbonate and rutile titanium dioxide in coating, and can form a film with good compactness by hydrogen bond and molecular group embedding effect in drying process, improve the heat resistance, water resistance and weather resistance of coating.

Description

Technical Field

[0001] The invention relates to an exposed high-temperature resistant oxygen-carbon modified waterproof coating, belonging to the technical field of coatings. Background Art

[0002] Acrylate emulsions are produced by emulsion polymerization of acrylic monomers such as methyl methacrylate, butyl acrylate, and methacrylic acid, along with emulsifiers and initiators. Water-based acrylic coatings can be produced by mixing the acrylate emulsion with appropriate amounts of pigments, fillers, and additives such as thickeners.

[0003] Waterborne acrylic coatings, with their advantages of low VOC emissions, excellent gloss, high solids content, and low price, have gradually become a key coatings category in the interior decoration and construction markets. Currently, the focus of waterborne acrylic coatings development is on environmentally friendly and high-performance products, such as those with enhanced weather resistance, scrub resistance, acid and alkali resistance, high temperature resistance, and corrosion resistance.

[0004] The performance of water-based acrylic coatings is determined by the combined properties of the acrylic emulsion and additives such as pigments, fillers, and thickeners added during the preparation of the coating. Therefore, in addition to pigments and fillers with excellent heat and water resistance, the heat and water resistance of additives such as thickeners is also crucial. However, thickeners such as hydroxyethyl cellulose, commonly used in water-based acrylic coatings, currently have poor heat and water resistance, resulting in variations in the overall heat and water resistance of water-based acrylic coatings. Summary of the Invention

[0005] The purpose of the present invention is to provide an exposed high-temperature resistant oxygen-carbon modified waterproof coating to solve the problem that the current water-based coatings using thickeners such as hydroxyethyl cellulose have poor heat resistance and waterproof performance.

[0006] The invention provides an exposed high-temperature resistant oxygen-carbon modified waterproof coating, comprising the following components in parts by mass: 100-120 parts of all-acrylic emulsion, 10-12 parts of propylene glycol, 25-45 parts of modified cellulose, 40-55 parts of kaolin, 65-85 parts of ground calcium carbonate, 155-185 parts of rutile titanium dioxide, 9-15 parts of a film-forming aid, and 240-270 parts of water; the modified cellulose is prepared by mixing a triazine silane coupling agent and hydroxyethyl cellulose at 90-100° C. for 4-8 hours, wherein the mass ratio of the triazine silane coupling agent to the hydroxyethyl cellulose is 30:(3-6); and the triazine silane coupling agent is prepared by mixing 1,3,5-triazine-2,4,6-trichloride and N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane at a molar ratio of 1:3.

[0007] Preferably, the temperature for the mixed reaction of 1,3,5-triazine-2,4,6-trichloride and N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane is 0-10° C., and the time is 4-6 hours.

[0008] Preferably, the preparation method of the triazine silane coupling agent is as follows: at 0-10° C., a dichloromethane solution of 1,3,5-triazine-2,4,6-triacyl chloride with a mass fraction of 15-25% is added to a dichloromethane solution of N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane with a mass fraction of 20-30%, and then an acid binding agent is added, and the mixture is mixed and reacted for 4-6 hours to obtain the triazine silane coupling agent.

[0009] Preferably, the molar substitution degree of the hydroxyethyl cellulose is 1.4 to 1.8.

[0010] Preferably, the method for the mixed reaction of the triazine silane coupling agent and hydroxyethyl cellulose is as follows: 30 to 35 parts by mass of hydroxyethyl cellulose is fully dissolved in a mixed solvent consisting of 250 to 260 parts by mass of isopropyl alcohol and 100 to 110 parts by mass of water to obtain a hydroxyethyl cellulose solution; the triazine silane coupling agent is fully dissolved in 300 to 350 parts by mass of isopropyl alcohol to obtain a triazine silane coupling agent solution; the hydroxyethyl cellulose solution and the triazine silane coupling agent solution are uniformly stirred, an appropriate amount of hydrochloric acid is added to adjust the pH of the system to 3 to 4, and a mixing reaction is carried out.

[0011] Preferably, the film-forming aid is propylene glycol methyl ether acetate.

[0012] Preferably, the all-acrylic emulsion is prepared by emulsion polymerization of polymerization monomers; the polymerization monomers are composed of methyl methacrylate, butyl acrylate and methacrylic acid in a mass ratio of (130-135):(130-135):(5-8).

[0013] Preferably, the preparation method of the all-acrylic emulsion is as follows: water, an emulsifier and a first initiator are mixed to obtain a mixed solution, the mixed solution is heated to 80-85° C., mixed and reacted for 20-25 minutes, then 5-15% of a polymerization monomer solution is added at 80-85° C., and finally a second initiator solution and the remaining polymerization monomer solution are added at 80-85° C., mixed and reacted for 5-9 hours, and after cooling, the pH is adjusted to 8-10 to obtain the all-acrylic emulsion.

[0014] Preferably, the polymerization monomer solution consists of water, an emulsifier and polymerization monomers.

[0015] Preferably, the first initiator and the second initiator are independently persulfate; and the persulfate is ammonium persulfate.

[0016] Preferably, the preparation method of the exposed high-temperature resistant oxygen-carbon modified waterproof coating is as follows: water is added to a blender, 32 to 36% of modified cellulose is added while stirring, and then rutile titanium dioxide, kaolin and heavy calcium carbonate are added in sequence. After stirring evenly, a sand mill is used to grind the mixture to a fineness of less than 20 μm to obtain a slurry; then the slurry, all-propylene emulsion, propylene glycol, film-forming aid and the remaining modified cellulose are stirred evenly to obtain an exposed high-temperature resistant oxygen-carbon modified waterproof coating.

[0017] The beneficial effects of the present invention are as follows:

[0018] (1) The present invention first uses the amino group on the aminosilane coupling agent to react with 1,3,5-triazine-2,4,6-trichloride to obtain a triazine silane coupling agent, and then uses the diethoxysilane on the triazine silane coupling agent to react with the hydroxyl group on the hydroxyethyl cellulose to convert the hydroxyl group into a hydrophobic and heat-resistant Si-OC bond. At the same time, the triazine ring with good thermal stability is used to effectively improve the heat and water resistance of the hydroxyethyl cellulose, thereby giving the water-based coating good heat and water resistance.

[0019] (2) While modifying the hydroxyethyl cellulose with the hydrophobic and heat-resistant Si-OC bond, the triazine silane coupling agent has a heat-resistant and hydrophobic triazine ring molecular core, and the side chains carry a large number of hydrophilic tertiary amino groups and hydrophobic amide groups. In addition, the large number of unreacted hydrophilic hydroxyl groups on the hydroxyethyl cellulose can give the modified cellulose good surface activity. At the same time, the triazine silane coupling agent with a branched structure can further increase the steric hindrance of the modified cellulose, improve the dispersion performance of pigments and fillers in the coating, prevent the sedimentation of pigments and fillers with a larger specific gravity, and thus improve the storage stability of the coating.

[0020] (3) While modifying the hydroxyethyl cellulose with hydrophobic and heat-resistant Si-OC bonds, a large number of tertiary amino nitrogen atoms and triazine ring nitrogen atoms are introduced. Therefore, when the modified cellulose comes into contact with water, it still has good solubility and dispersibility, and a large number of nitrogen atoms can be used to form hydrogen bonds with water, giving it good thixotropic properties, thereby improving the stability of the coating under static conditions without hindering the construction performance of the coating.

[0021] (4) While kaolin, heavy calcium carbonate, and rutile titanium dioxide provide good heat and water resistance, these pigment fillers also have good resistance to UV discoloration, which can effectively improve the weather resistance of the coating. In addition, the triazine ring and Si-OC bond on the modified cellulose also give the coating good light stability and weather resistance.

[0022] (5) The modified cellulose used in the present invention has a large number of tertiary amino groups, which can form hydrogen bonds with the hydroxyl groups on the surface of kaolin, heavy calcium carbonate and rutile titanium dioxide in the coating, thereby improving the stability of kaolin, heavy calcium carbonate and rutile titanium dioxide in the coating. In addition, during the drying process, a coating film with good density can be formed through hydrogen bonding and molecular group encapsulation, thereby improving the heat resistance, water resistance and weather resistance of the coating film.

[0023] (6) The exposed high-temperature resistant oxygen-carbon modified waterproof coating of the present invention does not contain fluorine elements and has good storage stability, heat resistance, waterproofness and weather resistance, and can meet the requirements for outdoor coating use. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of storage stability test results of exposed high-temperature resistant oxygen-carbon modified waterproof coatings of various embodiments of the present invention and comparative examples;

[0025] Figure 2 Schematic diagram of the test results of heat resistance and water resistance at room temperature of the exposed high-temperature resistant oxygen-carbon modified waterproof coatings of various embodiments of the present invention and comparative examples;

[0026] Figure 3 Schematic diagram of water resistance test results of exposed high-temperature resistant oxygen-carbon modified waterproof coatings of various embodiments of the present invention and comparative examples at 95°C;

[0027] Figure 4 Schematic diagram of weather resistance test results of exposed high-temperature resistant oxygen-carbon modified waterproof coatings of various embodiments of the present invention and comparative examples. DETAILED DESCRIPTION

[0028] The following examples are intended to further illustrate the present invention, but not to limit the scope of protection of the present invention.

[0029] Example 1

[0030] The exposed high-temperature resistant oxygen-carbon modified waterproof coating of this embodiment includes the following components in parts by mass: 100 parts of all-acrylic emulsion, 12 parts of propylene glycol, 25 parts of modified cellulose, 40 parts of kaolin, 75 parts of heavy calcium carbonate, 185 parts of rutile titanium dioxide, 9 parts of film-forming aid, and 270 parts of water.

[0031] Wherein, the film-forming aid is propylene glycol methyl ether acetate; the preparation method of modified cellulose is as follows:

[0032] (1) At 0°C, a 25% mass fraction dichloromethane solution of 1,3,5-triazine-2,4,6-trichloride was added dropwise to a 30% mass fraction dichloromethane solution of N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane (the molar ratio of 1,3,5-triazine-2,4,6-trichloride to N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane was 1:3), and then triethylamine was added as an acid-binding agent. The mixture was stirred for 6 hours, filtered, and the filtrate was evaporated to dryness to obtain a triazine silane coupling agent.

[0033] (2) 30 g of hydroxyethyl cellulose (molar substitution of 1.4 to 1.8) was fully dissolved in a mixed solvent consisting of 250 g of isopropyl alcohol and 100 g of water to obtain a hydroxyethyl cellulose solution; 3 g of triazine silane coupling agent was fully dissolved in 300 g of isopropyl alcohol to obtain a triazine silane coupling agent solution; the hydroxyethyl cellulose solution and the triazine silane coupling agent solution were stirred evenly, and an appropriate amount of hydrochloric acid was added to adjust the pH of the system to 3, and then the reaction system was heated to 90 ° C and stirred for 8 h. After the reaction was completed, the reaction was cooled to room temperature, the solvent was removed by rotary evaporation at 60 ° C, and then vacuum dried at 60 ° C for 24 h to obtain modified cellulose.

[0034] The preparation method of the all-acrylic emulsion is as follows: 140g of water, 0.4g of ammonium persulfate, 1.4g of sodium bicarbonate and 1.8g of sodium dodecyl sulfonate are added to a reactor, the reactor is heated to 80°C, 15% of a polymerization monomer solution is added to the reactor, and the mixture is stirred and reacted for 25 minutes. The remaining polymerization monomer solution and an initiator solution are then added to the reactor, the mixture is stirred and reacted for 5 hours, the mixture is cooled to 45°C, and the pH is adjusted to 10 with aqueous ammonia to obtain the all-acrylic emulsion; the polymerization monomer solution is composed of 50g of water, 5g of sodium dodecyl sulfonate, 130g of methyl methacrylate, 130g of butyl acrylate and 5g of methacrylic acid; and the initiator solution is composed of 1g of ammonium persulfate and 7g of water.

[0035] The preparation method of the exposed high-temperature resistant oxygen-carbon modified waterproof coating is as follows: water is added to a mixer, 36% of modified cellulose is added under stirring, and then rutile titanium dioxide, kaolin and heavy calcium carbonate are added in sequence. After stirring evenly, the mixture is ground with a sand mill to a fineness of less than 20 μm to obtain a slurry; the slurry, all-propylene emulsion, propylene glycol, film-forming aid and the remaining modified cellulose are stirred evenly to obtain an exposed high-temperature resistant oxygen-carbon modified waterproof coating.

[0036] Example 2

[0037] The exposed high-temperature resistant oxygen-carbon modified waterproof coating of this embodiment includes the following components in parts by mass: 110 parts of all-acrylic emulsion, 11 parts of propylene glycol, 35 parts of modified cellulose, 50 parts of kaolin, 85 parts of heavy calcium carbonate, 170 parts of rutile titanium dioxide, 12 parts of film-forming aid, and 250 parts of water.

[0038] Wherein, the film-forming aid is propylene glycol methyl ether acetate; the preparation method of modified cellulose is as follows:

[0039] (1) At 5°C, a 20% by mass solution of 1,3,5-triazine-2,4,6-trichloride in dichloromethane was added dropwise to a 25% by mass solution of N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane in dichloromethane (the molar ratio of 1,3,5-triazine-2,4,6-trichloride to N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane was 1:3), and then triethylamine was added as an acid-binding agent. The mixture was stirred for 5 h, filtered, and the filtrate was evaporated to dryness to obtain a triazine silane coupling agent.

[0040] (2) 30 g of hydroxyethyl cellulose (molar substitution of 1.4 to 1.8) was fully dissolved in a mixed solvent consisting of 250 g of isopropyl alcohol and 100 g of water to obtain a hydroxyethyl cellulose solution; 4 g of triazine silane coupling agent was fully dissolved in 300 g of isopropyl alcohol to obtain a triazine silane coupling agent solution; the hydroxyethyl cellulose solution and the triazine silane coupling agent solution were stirred evenly, an appropriate amount of hydrochloric acid was added to adjust the pH of the system to 3, and then the reaction system was heated to 95°C and stirred for 6 hours. After the reaction was completed, the reaction was cooled to room temperature, the solvent was removed by rotary evaporation at 60°C, and then vacuum dried at 60°C for 24 hours to obtain modified cellulose.

[0041] The preparation method of the all-acrylic emulsion is as follows: 140g of water, 0.4g of ammonium persulfate, 1.4g of sodium bicarbonate and 1.8g of sodium dodecyl sulfonate are added to a reactor, the reactor is heated to 82°C, and then 8% of the polymerization monomer solution is added to the reactor, stirred and reacted for 23 minutes, and then the remaining polymerization monomer solution and the initiator solution are added to the reactor, stirred and reacted for 7 hours, cooled to 45°C, and the pH is adjusted to 9 with ammonia water to obtain the all-acrylic emulsion; the polymerization monomer solution is composed of 50g of water, 5g of sodium dodecyl sulfonate, 132g of methyl methacrylate, 134g of butyl acrylate and 6g of methacrylic acid; the initiator solution is composed of 1g of ammonium persulfate and 7g of water.

[0042] The preparation method of the exposed high-temperature resistant oxygen-carbon modified waterproof coating is as follows: water is added to a blender, 34% of modified cellulose is added under stirring, and then rutile titanium dioxide, kaolin and heavy calcium carbonate are added in sequence. After stirring evenly, the mixture is ground with a sand mill to a fineness of less than 20 μm to obtain a slurry; the slurry, all-propylene emulsion, propylene glycol, film-forming aid and the remaining modified cellulose are stirred evenly to obtain an exposed high-temperature resistant oxygen-carbon modified waterproof coating.

[0043] Example 3

[0044] The exposed high-temperature resistant oxygen-carbon modified waterproof coating of this embodiment includes the following components in parts by mass: 120 parts of all-acrylic emulsion, 10 parts of propylene glycol, 45 parts of modified cellulose, 55 parts of kaolin, 65 parts of heavy calcium carbonate, 155 parts of rutile titanium dioxide, 15 parts of film-forming aid, and 240 parts of water.

[0045] Wherein, the film-forming aid is propylene glycol methyl ether acetate; the preparation method of modified cellulose is as follows:

[0046] (1) At 10°C, a 15% mass fraction of 1,3,5-triazine-2,4,6-trichloride in dichloromethane solution was added dropwise to a 20% mass fraction of N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane in dichloromethane solution (the molar ratio of 1,3,5-triazine-2,4,6-trichloride to N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane was 1:3), and then triethylamine was added as an acid binding agent. The mixture was stirred for 4 hours, filtered, and the filtrate was evaporated to dryness to obtain a triazine silane coupling agent.

[0047] (2) 30 g of hydroxyethyl cellulose (molar substitution of 1.4 to 1.8) was fully dissolved in a mixed solvent consisting of 250 g of isopropyl alcohol and 100 g of water to obtain a hydroxyethyl cellulose solution; 6 g of triazine silane coupling agent was fully dissolved in 300 g of isopropyl alcohol to obtain a triazine silane coupling agent solution; the hydroxyethyl cellulose solution and the triazine silane coupling agent solution were stirred evenly, and an appropriate amount of hydrochloric acid was added to adjust the pH of the system to 4, and then the reaction system was heated to 100 ° C and stirred for 4 hours. After the reaction was completed, the reaction system was cooled to room temperature, the solvent was removed by rotary evaporation at 60 ° C, and then vacuum dried at 60 ° C for 24 hours to obtain modified cellulose.

[0048] The preparation method of the all-acrylic emulsion is as follows: 140g of water, 0.4g of ammonium persulfate, 1.4g of sodium bicarbonate and 1.8g of sodium dodecyl sulfonate are added to a reactor, the reactor is heated to 85°C, 5% of a polymerization monomer solution is added to the reactor, and the mixture is stirred and reacted for 20 minutes. The remaining polymerization monomer solution and an initiator solution are then added to the reactor, and the mixture is stirred and reacted for 9 hours. The mixture is cooled to 45°C, and the pH is adjusted to 8 with aqueous ammonia to obtain the all-acrylic emulsion. The polymerization monomer solution consists of 50g of water, 5g of sodium dodecyl sulfonate, 135g of methyl methacrylate, 135g of butyl acrylate and 8g of methacrylic acid. The initiator solution consists of 1g of ammonium persulfate and 7g of water.

[0049] The preparation method of the exposed high-temperature resistant oxygen-carbon modified waterproof coating is as follows: water is added to a blender, 32% of modified cellulose is added under stirring, and then rutile titanium dioxide, kaolin and heavy calcium carbonate are added in sequence. After stirring evenly, the mixture is ground with a sand mill to a fineness of less than 20 μm to obtain a slurry; the slurry, all-propylene emulsion, propylene glycol, film-forming aid and the remaining modified cellulose are stirred evenly to obtain an exposed high-temperature resistant oxygen-carbon modified waterproof coating.

[0050] Comparative Example 1

[0051] The only difference between the exposed high-temperature resistant oxygen-carbon modified waterproof coating of this comparative example and the exposed high-temperature resistant oxygen-carbon modified waterproof coating of Example 1 is that in the exposed high-temperature resistant oxygen-carbon modified waterproof coating of this comparative example, the modified cellulose is replaced by hydroxyethyl cellulose (molar substitution degree is 1.4 to 1.8).

[0052] Comparative Example 2

[0053] The only difference between the exposed high-temperature resistant oxygen-carbon modified waterproof coating of this comparative example and the exposed high-temperature resistant oxygen-carbon modified waterproof coating of Example 1 is that in the exposed high-temperature resistant oxygen-carbon modified waterproof coating of this comparative example, the N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane used in the preparation of modified cellulose is replaced by N-(β-aminoethyl)-γ-aminopropyltriethoxysilane.

[0054] Comparative Example 3

[0055] The only difference between the exposed high-temperature resistant oxygen-carbon modified waterproof coating of this comparative example and the exposed high-temperature resistant oxygen-carbon modified waterproof coating of Example 1 is that in the exposed high-temperature resistant oxygen-carbon modified waterproof coating of this comparative example, the N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane used in the preparation of modified cellulose is replaced by γ-aminopropyltriethoxysilane.

[0056] Comparative Example 4

[0057] The only difference between the exposed high-temperature resistant oxygen-carbon modified waterproof coating of this comparative example and the exposed high-temperature resistant oxygen-carbon modified waterproof coating of Example 1 is that in the exposed high-temperature resistant oxygen-carbon modified waterproof coating of this comparative example, the N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane used in the preparation of modified cellulose is replaced by γ-aminopropylmethyldiethoxysilane.

[0058] Experimental example

[0059] To evaluate the comprehensive performance of the exposed, high-temperature-resistant, oxygen-carbon-modified waterproof coatings of each example and comparative example, the coatings were tested for storage stability, sag resistance, adhesion, heat resistance, water resistance, and weather resistance. Storage stability was tested according to the method specified in GB / T 6753.3-1986, "Test Method for Storage Stability of Coatings." Specifically, samples were placed in an electric forced-air drying oven at (50±2)°C, and the time until pigment sedimentation occurred was recorded. The initial time of pigment sedimentation was used as a quantitative indicator for evaluating storage stability. Adhesion was tested and rated according to the method specified in GBT 9286-1998, "Cross-cut Test for Paints and Varnishes," using tinplate as the substrate. The test method for heat resistance is as follows: apply the coating on a cement board, dry it at 80°C to form a film, place it in a 350°C oven, observe the blistering, wrinkling, peeling, and cracking of the coating, and record the time when the coating just starts to bubble, peel, wrinkle, or crack. The test method for water resistance is as follows: apply the coating on a cement board, dry it at 80°C to form a film, and soak it in room temperature water and 95°C water respectively, observe the blistering, wrinkling, and peeling of the coating, and record the time when the coating just starts to bubble, wrinkle, or peel at different water temperatures. Weather resistance is tested according to the method specified in the standard GB / T1865-1997 "Artificial Weathering and Artificial Radiation Exposure of Paints and Varnishes (Filtered Xenon Arc Radiation)". During the test, the absolute value of the color difference between the coating before the test and the test time of 2000h is detected and calculated, and the absolute value of the color difference is used as a quantitative indicator for evaluating weather resistance. The comprehensive performance of the exposed high-temperature resistant oxygen-carbon modified waterproof coatings of each embodiment and comparative example is shown in Table 1 and Figure 1-4 shown. Figure 1 The storage stability of the exposed high temperature resistant oxygen-carbon modified waterproof coatings of each embodiment and comparative example is shown in FIG. Figure 2 The heat resistance and water resistance at room temperature of the exposed high temperature resistant oxygen-carbon modified waterproof coating of each embodiment and comparative example are as follows: Figure 3 The water resistance of the exposed high temperature resistant oxygen-carbon modified waterproof coatings of each embodiment and comparative example at 95°C is shown in FIG. Figure 4 The weather resistance test results of the exposed high-temperature resistant oxygen-carbon modified waterproof coatings of various embodiments and comparative examples are shown.

[0060] Table 1 Comprehensive properties of exposed high temperature resistant oxygen-carbon modified waterproof coatings of various embodiments and comparative examples

[0061]

[0062] As shown in Table 1, the exposed high-temperature-resistant oxygen-carbon modified waterproof coatings of Examples 1-3 of the present invention all exhibit excellent storage stability, sag resistance, adhesion, heat resistance, water resistance, and weather resistance. Compared to unmodified hydroxyethyl cellulose, the modification of hydroxyethyl cellulose with a triazine silane coupling agent imparts excellent heat-resistant and waterproof properties to the coating film through the grafted hydrophobic and heat-resistant Si-OC bonds and triazine rings. Compared with Comparative Example 2 or Comparative Example 4, when N-(β-aminoethyl)-γ-aminopropyltriethoxysilane or γ-aminopropylmethyldiethoxysilane is used to replace N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane, the ethoxysilane groups on the silane coupling agent increase, resulting in the ethoxysilane groups on the triazine silane coupling agent being too dense, which may cause excessive reaction of hydroxyl groups on hydroxyethyl cellulose or excessive unreacted silanol groups on hydroxyethyl cellulose to form long hydrophobic siloxane chains coated on the surface of hydroxyethyl cellulose, resulting in an imbalance in the surface activity of the modified cellulose, affecting the binding between the modified cellulose and kaolin, heavy calcium carbonate and rutile titanium dioxide, and thus affecting the storage stability, heat resistance and water resistance of the coating. Compared with Comparative Example 3, when γ-aminopropyltriethoxysilane is used to replace N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane, the number of hydrophilic tertiary amino groups and nitrogen atoms in the molecular chain is reduced, resulting in a decrease in the number of hydrogen bonds formed with the hydroxyl groups on the surface of kaolin, heavy calcium carbonate and rutile titanium dioxide in the coating, which in turn leads to a decrease in the storage stability, heat resistance, weather resistance and water resistance of the coating.

Claims

1. An exposed high temperature resistant oxygen-carbon modified waterproof coating, characterized in that: The invention comprises the following components in parts by mass: 100-120 parts of all-acrylic emulsion, 10-12 parts of propylene glycol, 25-45 parts of modified cellulose, 40-55 parts of kaolin, 65-85 parts of ground calcium carbonate, 155-185 parts of rutile titanium dioxide, 9-15 parts of film-forming aid, and 240-270 parts of water; the modified cellulose is prepared by mixing a triazine silane coupling agent and hydroxyethyl cellulose at 90-100° C. for 4-8 hours, and the mass ratio of the triazine silane coupling agent to the hydroxyethyl cellulose is 30:(3-6); the triazine silane coupling agent is prepared by mixing 1,3,5-triazine-2,4,6-trichloride and N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane in a molar ratio of 1:

3.

2. The exposed high temperature resistant oxygen-carbon modified waterproof coating according to claim 1, characterized in that: The temperature for the mixed reaction of 1,3,5-triazine-2,4,6-triacyl chloride and N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane is 0-10° C., and the reaction time is 4-6 hours.

3. The exposed high temperature resistant oxygen-carbon modified waterproof coating according to claim 2, characterized in that: The preparation method of the triazine silane coupling agent is as follows: at 0-10° C., a dichloromethane solution of 1,3,5-triazine-2,4,6-triacyl chloride with a mass fraction of 15-25% is added to a dichloromethane solution of N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane with a mass fraction of 20-30%, and then an acid binding agent is added, and the mixture is mixed and reacted for 4-6 hours to obtain the triazine silane coupling agent.

4. The exposed high temperature resistant oxygen-carbon modified waterproof coating according to claim 1, characterized in that: The molar substitution degree of the hydroxyethyl cellulose is 1.4 to 1.

8.

5. The exposed high temperature resistant oxygen-carbon modified waterproof coating according to claim 1, characterized in that: The method for the mixed reaction of the triazine silane coupling agent and hydroxyethyl cellulose is as follows: 30 to 35 parts by mass of hydroxyethyl cellulose is fully dissolved in a mixed solvent consisting of 250 to 260 parts by mass of isopropyl alcohol and 100 to 110 parts by mass of water to obtain a hydroxyethyl cellulose solution; the triazine silane coupling agent is fully dissolved in 300 to 350 parts by mass of isopropyl alcohol to obtain a triazine silane coupling agent solution; the hydroxyethyl cellulose solution and the triazine silane coupling agent solution are uniformly stirred, an appropriate amount of hydrochloric acid is added to adjust the pH of the system to 3 to 4, and a mixed reaction is carried out.

6. The exposed high temperature resistant oxygen-carbon modified waterproof coating according to any one of claims 1 to 5, characterized in that: The film-forming aid is propylene glycol methyl ether acetate.

7. The exposed high temperature resistant oxygen-carbon modified waterproof coating according to any one of claims 1 to 5, characterized in that: The all-acrylic emulsion is prepared by emulsion polymerization of polymerization monomers; the polymerization monomers are composed of methyl methacrylate, butyl acrylate and methacrylic acid in a mass ratio of (130-135):(130-135):(5-8).

8. The exposed high temperature resistant oxygen-carbon modified waterproof coating according to claim 7, characterized in that: The preparation method of the all-acrylic emulsion is as follows: water, an emulsifier and a first initiator are mixed to obtain a mixed solution, the mixed solution is heated to 80-85° C., mixed and reacted for 20-25 minutes, then 5-15% of a polymerization monomer solution is added at 80-85° C., and finally a second initiator solution and the remaining polymerization monomer solution are added at 80-85° C., mixed and reacted for 5-9 hours, and after cooling, the pH is adjusted to 8-10 to obtain the all-acrylic emulsion.

9. The exposed high temperature resistant oxygen-carbon modified waterproof coating according to claim 8, characterized in that: The polymerization monomer solution consists of water, an emulsifier and polymerization monomers.

10. The exposed high temperature resistant oxygen-carbon modified waterproof coating according to claim 8, characterized in that: The first initiator and the second initiator are independently persulfate; the persulfate is ammonium persulfate.

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