A room temperature curing water-based high temperature resistant silicone resin emulsion and its preparation method and application

Abstract

The invention discloses a room temperature curing water-based high temperature resistant silicone resin emulsion and a preparation method and application thereof, and relates to the technical field of high temperature resistant coatings. The preparation comprises the following steps: S1, mixing an organic siloxane monomer containing a primary amine or a secondary amine and a methyl siloxane monomer, performing a hydrolysis reaction under acidic conditions to generate a siloxane prepolymer containing an amino group, and neutralizing and removing alcohol byproducts by adding a base; S2, stirring and dispersing an emulsifier and water, uniformly adding the siloxane prepolymer containing an amino group, and emulsifying at a high speed to generate a prepolymer emulsion; S3, dripping an alkaline catalyst and a phenyl siloxane monomer to obtain a water-based high temperature resistant silicone resin emulsion, neutralizing and removing alcohol byproducts by adding an acid; S4, adding an epoxy silane hydrolyzate curing agent to the silicone resin emulsion, stirring evenly, and obtaining a room temperature curing water-based high temperature resistant silicone resin emulsion. The whole preparation process of the invention is stable, the process flow is short, and it is easy to control, and the prepared product meets the application requirements of environmentally friendly high temperature resistant water-based coatings.

Description

Technical Field

[0001] The invention relates to the technical field of high temperature resistant coatings, and in particular to a room temperature curing water-based high temperature resistant silicone resin emulsion and a preparation method and application thereof. Background Art

[0002] With the development of modern industry, more and more equipment needs to serve under high temperature conditions, such as high temperature furnaces, high temperature pipelines, aircraft engines, exhaust pipes, etc. Compared with the development of expensive alloy materials to resist high temperature corrosion, it is simpler and more efficient to apply high temperature protective coatings on the surface of materials. Therefore, high temperature resistant coatings used in different temperatures and different fields are constantly being developed. High temperature resistant coatings are generally composed of high temperature resistant resins, pigments and fillers, and related additives. At present, the most widely used in the market is silicone high temperature resistant coatings, but its film-forming base material is usually solvent-based silicone resin, which has a high VOC content and poses a great safety hazard to people and the environment during construction. It does not conform to the current green and low-carbon development trend, and the paint film generally requires high temperature curing (150~250℃ curing for 0.5~1h) to achieve the best performance, resulting in limitations in the scope of application and increased resource and energy consumption. Therefore, in actual use, silicone resin, the base material of silicone high temperature resistant coatings, is gradually developing towards water-based and low curing temperature.

[0003] As a new type of green and environmentally friendly material, silicone resin emulsion can be used in the field of environmentally friendly high-temperature resistant coatings due to its excellent high and low temperature resistance, weather resistance, physiological inertness and flame retardancy. At present, the preparation methods of silicone resin emulsion mainly include mechanical emulsification method and emulsion polymerization method.

[0004] Mechanical emulsification is a method of forming a polymer emulsion by mechanically stirring a highly cross-linked silicone resin under the action of an external emulsifier or a hydrophilic group. After being water-based, the VOC content of the silicone resin product can be greatly reduced, giving it good environmentally friendly properties. In Chinese patent CN108641097A, epoxy-modified silicone resin, anionic nonionic emulsifier, and cosolvent are stirred evenly, slowly added to deionized water, and a water-based silicone emulsion is prepared by a high-speed emulsification phase inversion method. However, the silicone resin emulsion prepared by this method generally has the problem of large emulsifier dosage and high VOC content. In the synthesis of silicone resin, hydrophilic polyether segments, carboxylate or sulfonate groups are introduced, and a stable silicone resin emulsion can be prepared by self-emulsification. For example, in Chinese patent CN109400913B, a pre-dispersion of polyether-modified polysiloxane and silicone polymer is added to an emulsifying kettle containing a nonionic emulsifier, an emulsifier and water, and a thickener is added after rapid emulsification by heating to obtain a silicone resin emulsion product.

[0005] Emulsion polymerization is the most studied method for preparing silicone resin emulsion in recent years. It is a polymerization method in which silicone monomers are polymerized by emulsion polymerization under the action of catalysts, initiators, surfactants, etc. to prepare silicone resin emulsion. Compared with the mechanical emulsification method of solvent-based silicone resin, this method does not require complex processes such as water separation, water washing, concentration, polycondensation, desolventization and emulsification after the reaction. It can achieve polymerization and emulsification in one step, avoid the introduction of harmful organic solvents, and has the advantages of short process, low cost and low VOC. Chinese patent CN 118185014 A prepares water-based high-temperature resistant methylphenyl silicone resin emulsion by dropping siloxane monomers of different functionalities into a mixture of anionic non-ionic surfactants, catalysts and deionized water, and heating and stirring to perform emulsion polymerization. However, due to the large differences in the solubility of alkoxysilanes with different functionalities in water and the different hydrolysis and condensation rates of the monomers, homogeneous nucleation and droplet nucleation of the silane monomer occur simultaneously during the emulsion polymerization process, and a part of the siloxane prepolymer is easily gelled when polymerized in the aqueous phase, resulting in poor emulsion stability and increasing the difficulty of large-scale preparation.

[0006] From the above-mentioned reported patent information, it can be known that water-based silicone resin emulsion can be prepared by emulsion polymerization of alkoxysilane, but the emulsion is not very stable, and high temperature curing is required in the preparation of high temperature resistant coatings, resulting in limited application scope and increased resource and energy consumption. At the same time, existing silicone resin emulsion products basically have high VOC problems caused by organic solvents or alcohols, which seriously restricts their application and promotion in the field of green and low carbon. Summary of the invention

[0007] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a room temperature curing water-based high temperature resistant silicone resin emulsion and a preparation method and application thereof.

[0008] The objective of the present invention is achieved through the following technical solutions:

[0009] A method for preparing a room temperature curable water-based high temperature resistant silicone resin emulsion comprises the following steps:

[0010] S1. At room temperature, an organosiloxane monomer containing a primary amine or a secondary amine and an organosiloxane monomer containing a methyl group are mixed, and an acid is added dropwise to control the pH of the reaction system to be 4-5. After the acid is added dropwise, the temperature is raised to 40-50°C, and the reaction is kept warm for 2-3 hours to generate a siloxane prepolymer containing an amino group, which is then neutralized with a base and the alcohol by-product is removed;

[0011] S2. At room temperature, the emulsifier and water are stirred and dispersed uniformly, and then the aminosilicone prepolymer is added, the dropping time is controlled to 1-2 h, and the emulsification is stirred at a high speed for 1-2 h to obtain a prepolymer emulsion;

[0012] S3, raising the temperature to 50-70°C, respectively dropping the alkaline catalyst and phenylsiloxane monomer into the prepolymer emulsion, controlling the pH of the reaction system to be 11-13, the phenylsiloxane monomer dropping time to be 2-3 h, stirring and keeping the reaction temperature for 2-3 h to obtain a water-based high temperature resistant silicone resin emulsion, adding acid to neutralize and remove alcohol by-products;

[0013] S4, adding epoxy silane hydrolyzate curing agent to the water-based high temperature resistant silicone resin emulsion, stirring evenly, to obtain a room temperature curing water-based high temperature resistant silicone resin emulsion.

[0014] Specifically, the primary amine or secondary amine-containing organosiloxane monomer described in S1 includes one or more mixtures of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, (3-aminopropyl)triethoxysilane, (3-aminopropyl)trimethoxysilane, [3-(methylamino)propyl]trimethoxysilane and diethylenetriaminopropyltrimethoxysilane; the methyl-containing organosiloxane monomer includes one or more mixtures of methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane and dimethyldiethoxysilane; the acid is any one of hydrochloric acid, formic acid and acetic acid aqueous solution; the base is any one of sodium hydroxide, tetramethylammonium hydroxide and ammonia water.

[0015] The emulsifier includes any one or a combination of a cationic emulsifier and a nonionic emulsifier. The cationic emulsifier is a mixture of one or more of dodecyltrimethylammonium bromide, dodecyltrimethylammonium chloride, dodecyldimethylbenzylammonium chloride, dodecyldimethylbenzylammonium bromide, hexadecyltrimethylammonium bromide and hexadecyltrimethylammonium chloride; the nonionic emulsifier is a mixture of one or more of an octylphenol polyoxyethylene ether series and an isomeric tridecanol polyoxyethylene ether series.

[0016] The alkaline catalyst described in S3 is a 0.1 mol / L ammonia aqueous solution; the phenylsiloxane monomer is a mixture of one or more of phenyltrimethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane and diphenyldiethoxysilane; and the acid is any one of hydrochloric acid, formic acid and acetic acid aqueous solution.

[0017] The epoxysilane hydrolyzate curing agent is any one of 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 1,3-bis(3-glycidyloxypropyl)tetramethyldisiloxane and 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane hydrolyzate or a combination thereof.

[0018] The alcohol by-products are removed by vacuum distillation. During the vacuum distillation, the material temperature is 50-60 °C, the vacuum degree is -0.08 MPa, the vacuum distillation time is 1-2 h, and the distillation is stopped when the alcohol content in the emulsion is ≤1g / L as detected by gas chromatography.

[0019] The molar ratio of the organic siloxane monomer containing primary amine or secondary amine, the organic siloxane monomer containing methyl, and the organic siloxane monomer containing phenyl is 1-2:4-6:10-15; the mass ratio of the emulsifier to water is 1-2:70-90; the mass of the epoxy silane hydrolyzate curing agent accounts for 5% to 10% of the total mass of the overall siloxane monomer; wherein the total mass of the overall siloxane monomer is the total mass of the epoxy siloxane monomer, the siloxane monomer containing methyl, the siloxane monomer containing phenyl, and the organic siloxane monomer containing amino.

[0020] The second aspect of the present invention provides a room temperature curing water-based high temperature resistant silicone resin emulsion, which is prepared by the above preparation method.

[0021] The third aspect of the present invention provides the use of the room temperature curing water-based high temperature resistant silicone resin emulsion as a high temperature resistant water-based coating.

[0022] The beneficial effects of the present invention are:

[0023] In the present invention, silane monomers with different hydrophilicities are added dropwise to a water-emulsifier system in batches, so that during the emulsion polymerization process, siloxane oligomers produced by hydrolysis of siloxane monomers with good hydrophilicity and siloxane oligomers formed by droplet nucleation of siloxane monomers with poor hydrophilicity enter micelles for co-condensation, and the charge repulsion stabilization effect of the composite emulsification system is utilized to prepare an amino-containing silicone resin emulsion with excellent emulsion stability;

[0024] No organic solvent is added during the reaction, and the alcohol byproduct content in the silicone resin emulsion is ≤0.1% through reduced pressure distillation and online monitoring, so that the silicone resin emulsion has low VOC and environmentally friendly characteristics;

[0025] After the silicone resin emulsion is cured at room temperature to form a film, the 5% weight loss temperature exceeds 370°C, and it has excellent high temperature resistance. The performance test after room temperature curing is good, which is better than similar products at home and abroad. The entire preparation process is stable, the process flow is short, the operation is convenient, and it is easy to control. The prepared product meets the application requirements of environmentally friendly high temperature resistant water-based coatings.

[0026] The organic silicone resin emulsion with amino groups can undergo a ring-opening reaction with epoxy silane hydrolyzate curing agent to form an organic silicone resin with high curing activity, thereby achieving room temperature curing of the silicone resin emulsion;

[0027] Since the resin emulsion contains two heat-resistant elements, nitrogen and silicon, it can also be used in environmentally friendly polymer flame retardants, expanding its scope of application. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention. Example

[0029] At room temperature, 10.0 g N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 10.0 g methyltrimethoxysilane, 5 g dimethyldimethoxysilane, 5.0 g water and 0.5 g 0.01 mol / L HCl were stirred and reacted for 2 h to generate a siloxane prepolymer containing amino groups. Alkali was added to neutralize the reaction and the silicone resin emulsion was transferred to a distillation device. Low-boiling alcohol by-products were removed under reduced pressure and then filtered. (2) 100 g water, 2.3 g dodecyltrimethylammonium bromide and 3.7 g isomeric tridecanol polyoxyethylene ether 1307 were stirred evenly, and the synthesized siloxane prepolymer containing amino groups was added dropwise. The addition time was controlled to be 1 h. At the same time, high-speed shear emulsification was performed for 2 h to generate a prepolymer emulsion. (3) The temperature was raised to 50°C, and 0.5 ml ammonia water and 20.0 g phenyltrimethoxysilane were added dropwise to the prepolymer emulsion. The monomer addition time was controlled to be 2 h, continue stirring and heat-insulating the reaction for 2 h to obtain a water-based high-temperature resistant silicone resin emulsion. After cooling to room temperature, add hydrochloric acid to neutralize and transfer the silicone resin emulsion to a distillation device. After decompression to remove low-boiling point alcohol by-products, filter; (4) add 10 g of 3-glycidyloxypropyltrimethoxysilane hydrolyzate curing agent to the filtered silicone resin emulsion, stir and disperse evenly, and obtain a room temperature curing water-based high-temperature resistant silicone resin emulsion. Example

[0030] At room temperature, 10.0 g (3-aminopropyl) triethoxysilane, 10.0 g methyltrimethoxysilane, 5 g dimethyldimethoxysilane, 5.0 g water and 0.5 g 0.01 mol / L HCl were stirred and reacted for 2 h to generate a siloxane prepolymer containing amino groups. Alkali was added to neutralize the reaction and the silicone resin emulsion was transferred to a distillation device. Low-boiling alcohol by-products were removed under reduced pressure and then filtered. (2) 100 g water, 2.7 g dodecyltrimethylammonium chloride and 3.9 g isomeric tridecanol polyoxyethylene ether 1309 were stirred evenly, and the synthesized siloxane prepolymer containing amino groups was added dropwise. The total dropping time was controlled to be 1 h. At the same time, high-speed shear emulsification was performed for 2 h to generate a prepolymer emulsion. (3) The temperature was raised to 50°C, and 0.5 ml ammonia water and 20.0 g diphenyldimethoxysilane were added dropwise to the prepolymer emulsion at the same time. The monomer dropping time was controlled to be 2 h, continue stirring and heat-insulating the reaction for 2 h to obtain a water-based high-temperature resistant silicone resin emulsion. After cooling to room temperature, add hydrochloric acid to neutralize and transfer the silicone resin emulsion to a distillation device. After decompression to remove low-boiling point alcohol by-products, filter; (4) add 10 g of 3-glycidyloxypropylmethyldimethoxysilane hydrolyzate curing agent to the filtered silicone resin emulsion, stir and disperse evenly, and obtain a room temperature curing water-based high-temperature resistant silicone resin emulsion. Example

[0031] At room temperature, 10.0 g (3-aminopropyl) trimethoxysilane, 10.0 g methyl trimethoxysilane, 5 g dimethyl dimethoxysilane, 5.0 g water and 0.5 g 0.01 mol / L HCl were stirred and reacted for 2 h to generate a siloxane prepolymer containing amino groups. Alkali was added to neutralize the reaction and the silicone resin emulsion was transferred to a distillation apparatus. Low-boiling alcohol by-products were removed under reduced pressure and then filtered. (2) 100 g water, 2.2 g dodecyl dimethyl benzyl ammonium bromide and 3.2 g isomeric tridecanol polyoxyethylene ether 1303 were stirred evenly, and the synthesized siloxane prepolymer containing amino groups was added dropwise. The total dropping time was controlled to be 1 h. At the same time, high-speed shear emulsification was performed for 2 h to generate a prepolymer emulsion. (3) The temperature was raised to 50 °C, and 0.5 ml ammonia water and 20.0 g phenyl triethoxysilane were added dropwise to the prepolymer emulsion. The monomer dropping time was controlled to be 2 h, continue stirring and heat-insulating the reaction for 2 h to obtain a water-based high-temperature resistant silicone resin emulsion. After cooling to room temperature, add hydrochloric acid to neutralize and transfer the silicone resin emulsion to a distillation device. After decompression to remove low-boiling point alcohol by-products, filter; (4) add 10 g of 3-glycidyl ether oxypropyl methyl diethoxy silane hydrolyzate curing agent to the filtered silicone resin emulsion, stir and disperse evenly, and obtain a room temperature curing water-based high-temperature resistant silicone resin emulsion. Example

[0032] At room temperature, 10.0 g [3-(methylamino)propyl]trimethoxysilane, 10.0 g methyltriethoxysilane, 5 g dimethyldiethoxysilane, 5.0 g water and 0.5 g 0.01 mol / L HCl were stirred and reacted for 2 h to generate a siloxane prepolymer containing amino groups. Alkali was added to neutralize the reaction and the silicone resin emulsion was transferred to a distillation device. Low-boiling alcohol by-products were removed under reduced pressure and then filtered. (2) 100 g water, 2.3 g hexadecyltrimethylammonium bromide and 3.7 g octylphenol polyoxyethylene ether OP-10 were stirred evenly, and the synthesized siloxane prepolymer containing amino groups was added dropwise. The total dropping time was controlled to be 1 h. At the same time, high-speed shear emulsification was performed for 2 h to generate a prepolymer emulsion. (3) The temperature was raised to 50 ° C, and 0.5 ml ammonia water and 20.0 g phenyltrimethoxysilane were added to the prepolymer emulsion at the same time. The monomer dropping time was controlled to be 2 h, continue stirring and heat-insulating the reaction for 2 h to obtain a water-based high-temperature resistant silicone resin emulsion. After cooling to room temperature, add hydrochloric acid to neutralize and transfer the silicone resin emulsion to a distillation device. After decompression to remove low-boiling point alcohol by-products, filter; (4) add 10 g of 1,3-bis(3-glycidyloxypropyl)tetramethyldisiloxane hydrolyzate curing agent to the filtered silicone resin emulsion, stir and disperse evenly, and obtain a room temperature curing water-based high-temperature resistant silicone resin emulsion.

[0033] The room temperature curable water-based high temperature resistant silicone resin emulsion prepared in the example was subjected to performance tests, and the results are shown in Table 1.

[0034] Table 1

[0035]

[0036] Note: T 5% It indicates the temperature at which the silicone resin emulsion loses 5% of its mass after curing, and is defined as the initial decomposition temperature to judge the high temperature resistance of the silicone resin emulsion.

[0037] The prepared silicone resin emulsion was compounded with related additives such as high temperature resistant pigments and fillers, dispersants, wetting agents and defoamers, and the viscosity of the system was adjusted by a thickener. After filtering, a water-based silicone resin coating was obtained. The water-based silicone resin coating was coated on a stainless steel plate and cured at room temperature to obtain a water-based silicone resin coating sample (thickness: 20-30 μm). The performance of the coating was tested, as shown in Table 2:

[0038] Table 2

[0039]

[0040] In summary, the room temperature curable water-based high temperature resistant silicone resin emulsion prepared by the present invention has good stability, can be cured at room temperature, has excellent high temperature resistance, is safe and environmentally friendly, and has high application value.

[0041] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. A method for preparing a room temperature curing water-based high temperature resistant silicone resin emulsion, characterized in that: The following steps are involved: S1. At room temperature, an organosiloxane monomer containing a primary amine or a secondary amine and an organosiloxane monomer containing a methyl group are mixed, and an acid is added dropwise to control the pH of the reaction system to be 4-5. After the acid is added dropwise, the temperature is raised to 40-50°C, and the reaction is kept warm for 2-3 hours to generate a siloxane prepolymer containing an amino group, which is then neutralized with a base and the alcohol by-product is removed; S2. At room temperature, the emulsifier and water are stirred and dispersed uniformly, and then the aminosilicone prepolymer is added, the dropping time is controlled to 1-2 h, and the emulsification is stirred at a high speed for 1-2 h to obtain a prepolymer emulsion; S3, raising the temperature to 50-70°C, respectively dropping the alkaline catalyst and phenylsiloxane monomer into the prepolymer emulsion, controlling the pH of the reaction system to be 11-13, the phenylsiloxane monomer dropping time to be 2-3 h, stirring and keeping the reaction temperature for 2-3 h to obtain a water-based high temperature resistant silicone resin emulsion, adding acid to neutralize and remove alcohol by-products; S4, adding epoxy silane hydrolyzate curing agent to the water-based high temperature resistant silicone resin emulsion, stirring evenly, to obtain a room temperature curing water-based high temperature resistant silicone resin emulsion; The molar ratio of the primary or secondary amine-containing organosiloxane monomer, the methyl-containing organosiloxane monomer, and the phenyl-containing organosiloxane monomer is 1-2:4-6:10-15; The mass of the epoxysilane hydrolyzate curing agent accounts for 5% to 10% of the total mass of the overall siloxane monomers; wherein the total mass of the overall siloxane monomers is the total mass of the epoxysiloxane monomers, the methyl-containing siloxane monomers, the phenyl-containing siloxane monomers and the amino-containing organic siloxane monomers.

2. The preparation method according to claim 1, characterized in that: The primary or secondary amine-containing organosiloxane monomer described in S1 includes one or more mixtures of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, (3-aminopropyl)triethoxysilane, (3-aminopropyl)trimethoxysilane, [3-(methylamino)propyl]trimethoxysilane and diethylenetriaminopropyltrimethoxysilane; the methyl-containing organosiloxane monomer includes one or more mixtures of methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane and dimethyldiethoxysilane; the acid described in S1 is any one of hydrochloric acid, formic acid and acetic acid aqueous solution; the base described in S1 is any one of sodium hydroxide, tetramethylammonium hydroxide and ammonia water.

3. The preparation method according to claim 1, characterized in that: The emulsifier described in S2 includes any one or a combination of cationic emulsifiers and non-ionic emulsifiers, wherein the cationic emulsifier is a mixture of one or more of dodecyltrimethylammonium bromide, dodecyltrimethylammonium chloride, dodecyldimethylbenzylammonium chloride, dodecyldimethylbenzylammonium bromide, hexadecyltrimethylammonium bromide and hexadecyltrimethylammonium chloride; and the non-ionic emulsifier is a mixture of one or more of octylphenol polyoxyethylene ether series and isomeric tridecyl alcohol polyoxyethylene ether series.

4. The preparation method according to claim 1, characterized in that: The alkaline catalyst described in S3 is a 0.1 mol / L ammonia aqueous solution; the phenylsiloxane monomer is a mixture of one or more of phenyltrimethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane and diphenyldiethoxysilane; the acid described in S3 is any one of hydrochloric acid, formic acid and acetic acid aqueous solution.

5. The preparation method according to claim 1, characterized in that: The epoxy silane hydrolyzate curing agent described in S4 is any one of 3-glycidyloxypropyl trimethoxysilane, 3-glycidyloxypropyl methyl dimethoxysilane, 3-glycidyloxypropyl methyl diethoxysilane, 1,3-bis(3-glycidyloxypropyl)tetramethyldisiloxane and 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane hydrolyzate or a combination thereof.

6. The preparation method according to claim 1, characterized in that: The alcohol by-products described in S1 and S3 are removed by vacuum distillation. During the vacuum distillation, the material temperature is 50-60°C, the vacuum degree is -0.08 MPa, the vacuum distillation time is 1-2h, and the distillation is stopped when the alcohol content in the emulsion is ≤1g / L detected by gas chromatography.

7. The preparation method according to claim 1, characterized in that: The mass ratio of the emulsifier to water is 1-2:70-90.

8. A room temperature curing water-based high temperature resistant silicone resin emulsion, characterized in that: The method is prepared by any one of claims 1 to 7.

9. Use of the room temperature curing water-based high temperature resistant silicone resin emulsion as claimed in claim 8 as a high temperature resistant water-based coating.

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