Exposed high-temperature-resistant oxygen-carbon modified waterproof coating

Abstract

The invention relates to an exposed high-temperature-resistant oxygen-carbon modified waterproof coating, and belongs to the technical field of coatings. The preparation method comprises the following steps: firstly, reacting amino on an amino silane coupling agent with 1, 3, 5-triazine-2, 4, 6-triacyl chloride to obtain a triazine silane coupling agent, then reacting diethoxysilane on the triazine silane coupling agent with hydroxyl on hydroxyethyl cellulose to convert the hydroxyl into hydrophobic and heat-resistant Si-O-C bonds, and thus obtaining the hydrophobic and heat-resistant hydroxyethyl cellulose. Meanwhile, the triazine ring with good thermal stability is utilized, so that the heat resistance and the water resistance of the hydroxyethyl cellulose are effectively improved. The modified cellulose has a large number of tertiary amino groups which can form hydrogen bonds with hydroxyl groups on the surfaces of kaolin, heavy calcium carbonate and rutile type titanium dioxide in the coating, so that the stability of the kaolin, the heavy calcium carbonate and the rutile type titanium dioxide in the coating is improved; in the drying process, a coating film with good compactness can be formed through a hydrogen bond and a molecular group embedding effect, so that the heat resistance, the water resistance and the weather resistance of the coating film are improved.

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] Acrylic emulsion is obtained by emulsion polymerization of acrylic monomers such as methyl methacrylate, butyl acrylate, methacrylic acid, etc., with the addition of emulsifiers, initiators, etc. Acrylic emulsion can be mixed with appropriate amounts of pigments, fillers, thickeners and other additives to produce water-based acrylic paint.

[0003] Waterborne acrylic paint has the advantages of low VOC emission, good gloss, high solid content and low price, and has gradually developed into one of the important paint varieties in the fields of decoration and construction market. At present, the focus of waterborne acrylic paint is on the research and development of environmentally friendly products and high-performance products, such as weather resistance, scrub resistance, acid and alkali resistance, high temperature resistance, and corrosion resistance.

[0004] The performance of water-based acrylic paint is determined by the performance of acrylic emulsion and additives such as pigments, fillers and thickeners added when preparing water-based acrylic paint. Therefore, in addition to pigments and fillers with good heat and water resistance, the heat and water resistance of thickeners and other additives are also crucial. However, thickeners such as hydroxyethyl cellulose commonly used in water-based acrylic paints currently have poor heat and water resistance, resulting in deviations in the overall heat and water resistance of water-based acrylic paints. 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 coating using thickeners such as hydroxyethyl cellulose has 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 heavy calcium carbonate, 155-185 parts of rutile titanium dioxide, 9-15 parts of film-forming aids, 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 and reacting 1,3,5-triazine-2,4,6-trichloride and N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane in 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 to 10° C., a dichloromethane solution of 1,3,5-triazine-2,4,6-triacyl chloride with a mass fraction of 15 to 25% is added to a dichloromethane solution of N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane with a mass fraction of 20 to 30%, and then an acid binding agent is added, and the mixture is reacted for 4 to 6 hours to obtain a 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 isopropanol 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 isopropanol to obtain a triazine silane coupling agent solution; the hydroxyethyl cellulose solution and the triazine silane coupling agent solution are stirred evenly, an appropriate amount of hydrochloric acid is added, the pH of the system is adjusted to 3 to 4, and a mixed 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: add water into a mixer, add 32-36% of modified cellulose under stirring, and then add rutile titanium dioxide, kaolin and heavy calcium carbonate in sequence, stir evenly, and grind with a sand mill to a fineness of less than 20 μm to obtain a slurry; then stir the slurry, all-propylene emulsion, propylene glycol, film-forming aid and the remaining modified cellulose 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 firstly utilizes 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 utilizes 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 utilized to effectively improve the heat-resistant and waterproof properties of the hydroxyethyl cellulose, thereby giving the water-based coating good heat-resistant and waterproof properties.

[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 hydrophobic triazine ring molecular core, and carries a large number of hydrophilic tertiary amino groups and hydrophobic amide groups on the side chains. 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 precipitation 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. In addition, 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 element 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 It is a schematic diagram of the storage stability test results of the exposed high temperature resistant oxygen-carbon modified waterproof coatings of various embodiments of the present invention and comparative examples;

[0025] Figure 2 It is a 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 It is a schematic diagram of the water resistance test results of the 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 It is a schematic diagram of the weather resistance test results of the 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 rather than 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 the modified cellulose is as follows:

[0032] (1) At 0°C, a 25% by mass solution of 1,3,5-triazine-2,4,6-trichloride in dichloromethane was added dropwise to a 30% 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 acid binding agent was added. 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 degree is 1.4-1.8) is fully dissolved in a mixed solvent consisting of 250 g of isopropanol and 100 g of water to obtain a hydroxyethyl cellulose solution; 3 g of triazine silane coupling agent is fully dissolved in 300 g of isopropanol to obtain a triazine silane coupling agent solution; the hydroxyethyl cellulose solution and the triazine silane coupling agent solution are stirred evenly, an appropriate amount of hydrochloric acid is added to adjust the pH of the system to 3, and then the reaction system is heated to 90° C. and stirred for 8 h. After the reaction is completed, the reaction system is cooled to room temperature, the solvent is 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, and then 15% of a polymerization monomer solution is added to the reactor, stirred for reaction for 25 minutes, and then the remaining polymerization monomer solution and an initiator solution are added to the reactor, stirred for reaction for 5 hours, cooled to 45°C, and the pH is adjusted to 10 with aqueous ammonia to obtain the all-acrylic emulsion; the polymerization monomer solution consists of 50g of water, 5g of sodium dodecyl sulfonate, 130g of methyl methacrylate, 130g of butyl acrylate and 5g of methacrylic acid; the initiator solution consists 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: add water into a mixer, add 36% of modified cellulose under stirring, and then add rutile titanium dioxide, kaolin and heavy calcium carbonate in sequence, stir evenly, and grind with a sand mill to a fineness of less than 20 μm to obtain a slurry; then stir the slurry, all-propylene emulsion, propylene glycol, film-forming aid and the remaining modified cellulose 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 the 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 acid binding agent was added. 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 degree is 1.4-1.8) is fully dissolved in a mixed solvent consisting of 250 g of isopropanol and 100 g of water to obtain a hydroxyethyl cellulose solution; 4 g of triazine silane coupling agent is fully dissolved in 300 g of isopropanol to obtain a triazine silane coupling agent solution; the hydroxyethyl cellulose solution and the triazine silane coupling agent solution are stirred evenly, an appropriate amount of hydrochloric acid is added to adjust the pH of the system to 3, and then the reaction system is heated to 95° C. and stirred for 6 h. After the reaction is completed, the reaction system is cooled to room temperature, the solvent is removed by rotary evaporation at 60° C., and then vacuum dried at 60° C. for 24 h 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 for reaction for 23 minutes, and then the remaining polymerization monomer solution and the initiator solution are added to the reactor, stirred for reaction 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: add water into a mixer, add 34% of modified cellulose under stirring, and then add rutile titanium dioxide, kaolin and heavy calcium carbonate in sequence, stir evenly, and grind with a sand mill to a fineness of less than 20 μm to obtain a slurry; then stir the slurry, all-propylene emulsion, propylene glycol, film-forming aid and the remaining modified cellulose 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 the modified cellulose is as follows:

[0046] (1) At 10° C., a 15% by mass solution of 1,3,5-triazine-2,4,6-trichloride in dichloromethane was added dropwise to a 20% 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 acid binding agent was added. The mixture was stirred for 4 h, 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 isopropanol 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 isopropanol 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 4, and then the reaction system was heated to 100° C. and stirred for 4 h. 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 h 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, and then 5% of the polymerization monomer solution is added to the reactor, stirred for reaction for 20 minutes, and then the remaining polymerization monomer solution and the initiator solution are added to the reactor, stirred for reaction for 9 hours, cooled to 45°C, and the pH is adjusted to 8 with ammonia water to obtain the all-acrylic emulsion; the polymerization monomer solution is composed 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 is composed 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: add water into a mixer, add 32% of modified cellulose under stirring, and then add rutile titanium dioxide, kaolin and heavy calcium carbonate in sequence, stir evenly, and grind with a sand mill to a fineness of less than 20 μm to obtain a slurry; then stir the slurry, all-propylene emulsion, propylene glycol, film-forming aid and the remaining modified cellulose evenly to obtain an exposed high-temperature resistant oxygen-carbon modified waterproof coating.

[0050] Comparative Example 1

[0051] The 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] In order to evaluate the comprehensive performance of the exposed high temperature resistant oxygen-carbon modified waterproof coatings of each embodiment and comparative example, the storage stability, sag, adhesion, heat resistance, water resistance and weather resistance of the waterproof coatings were tested respectively. Among them, the storage stability was tested according to the method specified in the standard GB / T 6753.3-1986 "Test method for storage stability of coatings", specifically, the sample was placed in an electric blast drying oven at (50±2)℃, and then the time when the pigment sedimentation of the coating appeared was recorded, and the initial time when the pigment sedimentation of the coating appeared was used as an index for quantitative evaluation of storage stability. Adhesion was tested and rated according to the method specified in the standard GBT9286-1998 "Scratching test of paint and varnish film", and the substrate used in the test was tinplate. 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 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 coating 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 shown in FIG. 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 performance of exposed high temperature resistant oxygen-carbon modified waterproof coatings of various embodiments and comparative examples

[0061]

[0062] As can be seen from Table 1, the exposed high temperature resistant oxygen-carbon modified waterproof coatings of Examples 1-3 of the present invention all have good storage stability, sag, adhesion, heat resistance, water resistance and weather resistance. Compared with unmodified hydroxyethyl cellulose, the use of triazine silane coupling agent to modify hydroxyethyl cellulose can give the coating film good heat resistance and waterproof properties 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 a long hydrophobic siloxane chain coated on the surface of hydroxyethyl cellulose, resulting in an imbalance in the surface activity of the modified cellulose, affecting the bonding between the modified cellulose and kaolin, heavy calcium carbonate and rutile titanium dioxide, and further 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 weight: 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 heavy 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 of 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.

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 to 10° C., a dichloromethane solution of 1,3,5-triazine-2,4,6-triacyl chloride with a mass fraction of 15 to 25% is added to a dichloromethane solution of N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane with a mass fraction of 20 to 30%, and then an acid binding agent is added, and the mixture is reacted for 4 to 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 isopropanol 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 isopropanol 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, the pH of the system is adjusted 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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