CN105176296A - High temperature resistant coating based on polysilsesquioxane modification and its application - Google Patents

Abstract

The invention discloses a high-temperature-resistant coating based on polysilsesquioxane modification and application thereof. In some embodiments, the high temperature resistant coating comprises the following components in percentage by mass: 15-30% of modified organic resin, 25-50% of modified pigment filler, 1-5% of dispersant, 0.1-3% of flatting agent, 0.2-3% of composite additive and 3-20% of solvent. According to the invention, the polysilsesquioxane is used as a modifier to modify the film-forming resin and the pigment filler, so that the quality of the high-temperature-resistant coating can be further improved, the comprehensive performance of the coating can be effectively improved, and particularly, the hardness, stability, scratch resistance, compactness and cracking resistance of the coating under a high-temperature condition can be greatly improved.

Description

High temperature resistant coating based on polysilsesquioxane modification and its application

technical field

The invention belongs to the field of materials and relates to a special functional coating, in particular to a polysilsesquioxane-based modified high temperature resistant coating and its application.

Background technique

High temperature resistant coatings generally refer to coatings with a temperature resistance above 200°C, the paint film does not change color, does not fall off, and can still maintain appropriate physical and mechanical properties. It is a special functional coating that enables the protected object to function normally in a high temperature environment. . With the rapid development of industries such as aviation, aerospace, automobiles and household appliances, the requirements for the performance of metal or glass materials are getting higher and higher, and high-temperature resistant coatings are also receiving more and more attention and can be used more and more widely. . Due to the harsh service environment requirements, not only the coating needs to be able to be used in a higher service temperature and a more harsh environment, but also requires the coating to have good hardness, adhesion, wear resistance, etc. at high temperatures. However, the existing high-temperature-resistant coatings generally have disadvantages such as poor adhesion, easy cracking, pulverization, and rapid hardness drop under high-temperature conditions, especially in use environments exceeding 200°C.

Contents of the invention

Aiming at the deficiencies of the prior art, the object of the present invention is to provide a polysilsesquioxane-based modified high temperature resistant coating and its application.

In order to realize the aforementioned object of the invention, the technical solutions adopted in the present invention include:

A high temperature resistant coating based on polysilsesquioxane modification, comprising:

Modified organic resins selected from organic resins modified by polysilsesquioxanes,

Modified pigments and fillers, including pigments and/or fillers modified by polysilsesquioxanes,

You can choose to add or not add coalescents,

And, you can choose to add or not add solvent;

Moreover, at least one component in the high temperature resistant coating is fluid, and the at least one component can be uniformly mixed with other components in the high temperature resistant coating to form the high temperature resistant coating in a fluid state.

In some embodiments, the high temperature resistant coating includes 15wt%-30wt% modified organic resin.

Preferably, the organic resin includes any one or a combination of two or more of polyether ether ketone resins, fluorocarbon resins, polyphenylene sulfide resins, silicone resins, and polyimide resins.

The high temperature resistant paint includes 25wt%-50wt% of modified pigments and fillers.

Preferably, the pigment includes any one or both of carbon black, cobalt black, cobalt blue, cobalt green, copper chrome black, titanium nickel yellow, titanium white, cadmium red, titanium chrome brown, iron oxide red, and zirconia. more than one combination.

Preferably, the filler includes any one or a combination of two or more of calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, wollastonite, mica, and quartz powder.

Preferably, the mass ratio of the pigment to the filler is 2:1˜1:3.

In some embodiments, the film-forming aids include any one or a combination of two or more of dispersants, leveling agents, and compounding aids.

Preferably, the high-temperature-resistant coating includes: 1wt%-5wt% of dispersant, 0.1wt%-3wt% of leveling agent, and 0.2wt%-3wt% of compounding aid.

Among them, the dispersant (Dispersant) is a substance that can reduce the aggregation of solid or liquid particles in the dispersion system, for example, it can be selected from a surfactant with two opposite properties of lipophilicity and hydrophilicity in the molecule, which can be uniform Disperse solid and liquid particles of inorganic and organic pigments that are difficult to dissolve in liquid, and at the same time prevent the particles from settling and agglomerating to form a stable suspension.

Preferably, the dispersants include but are not limited to polyamides, fatty acid polyalcohol esters, silicones and other commercially available varieties, such as BYK-164, BYK-174 (Bick, Germany), Silok-714 ( Guangzhou Sloco Chemical Co., Ltd.), any one or a combination of two or more, but not limited thereto.

Among them, leveling agent (Leveling agent), leveling agent is a kind of commonly used coating additive, it can promote coating to form a level off, smooth, uniform coating film in the drying film-forming process. A class of substances that can effectively reduce the surface tension of coating fluids and improve their leveling and uniformity.

Described leveling agents include but are not limited to acrylates, urea-formaldehyde resins, silicone resins and other commercially available varieties, such as BYK-313, BYK-300 (German BYK), DC-57 (U.S. Dow Corning ), Silok-810 (Guangzhou Silok Chemical Co., Ltd.).

The auxiliary agents are preferably suitable leveling agents, defoamers, thickeners and other auxiliary solvents commonly used in high temperature resistant coatings known in the industry, and are not limited thereto.

Preferably, the composite auxiliary agent includes a polymer adhesion promoter with an epoxy group and a silane coupling agent with an amino or epoxy group at a mass ratio of 1:1 to 1:5.

In some embodiments, the high temperature resistant coating based on polysilsesquioxane modification further includes 3wt%-20wt% solvent.

Preferably, the solvent includes any one of benzene, toluene, xylene, normal hexane, dioxane, DBE (high boiling point solvent mixed dibasic acid ester), naphtha, ethyl acetate or butyl acetate Or a combination of two or more, but not limited thereto.

In some embodiments, the general chemical formula of the polysilsesquioxane is (RSiO _3/2 )n; wherein, if R is a reactive group, the R group includes alkenyl, epoxy or any one of amino groups or a combination of two or more; if R is an inert group, the R group includes any one or a combination of two or more of C1-C4 alkyl, alkylene or aryl groups ; n is any integer within 20-40.

In some more specific embodiments, the preparation method of the modified organic resin comprises: feeding polysilsesquioxane and organic resin at a mass ratio of 1:5 to 1:10, and adding a catalyst and an organic solvent, After uniform mixing, react at 45-85° C. for 2-4 hours to obtain a modified organic resin containing silsesquioxane.

Preferably, the catalyst is used in an amount of 0.15%-0.3% of the total mass of the modified organic resin preparation reaction system.

Preferably, the amount of the organic solvent used is 20% of the mass of the organic resin.

Preferably, the catalyst includes tetramethylammonium hydroxide, tetrabutylammonium hydroxide, tetrabutylphosphonium acetate, triethanolamine, triphenylphosphine, benzyldimethylamine, dibutyltin dilaurate, triethylene Any one or a combination of two or more of the base diamines, but not limited thereto.

Preferably, the organic solvent includes toluene and/or xylene, but not limited thereto.

In some embodiments, the preparation method of the modified pigment and filler includes:

Disperse the pigments and fillers in the coupling agent solution, reflux and stir for 0.5h-2h at a temperature of 40°C to 80°C, then separate the crude pigments and fillers, and then mix polysilsesquioxane and crude pigments The filler and the organic solvent are mixed at a mass ratio of 1:5:6 to 1:10:11, and then reflux reaction is carried out at a temperature of 40°C to 85°C for 0.5h to 2h to obtain the modified pigment and filler.

Preferably, the coupling agent solution is selected from ethanol solutions with a concentration of 1wt%-10wt% coupling agent.

Preferably, the coupling agent includes any one or a combination of two or more of KH550, KH560, KH570 or KH590, but is not limited thereto.

Preferably, the organic solvent includes toluene and/or xylene.

The invention also proposes the application of the polysilsesquioxane-based modified high-temperature-resistant coating.

For example, some embodiments provide a high-temperature-resistant coating, which is mainly formed by curing the high-temperature-resistant coating based on polysilsesquioxane modification.

For example, a method for preparing a high temperature resistant coating is provided in some embodiments, comprising: coating the high temperature resistant coating based on polysilsesquioxane modification on a substrate, and then coating the substrate at a temperature of 150 The coating is cured under the condition of ℃-300℃ to form the coating.

For example, in some embodiments there is provided a device comprising the high temperature resistant coating described above.

The high-temperature-resistant coating based on polysilsesquioxane modification can be widely used in industries such as aviation, automobiles, and civil electrical appliances.

The invention uses polysilsesquioxane as a modifier to physically and chemically modify the film-forming resin and pigments and fillers, and utilizes the chemical reaction between the polysilsesquioxane and the surfaces of organic resins and inorganic pigments and fillers. On the one hand, the problem of sudden drop in hardness of the coating at high temperature can be improved by introducing polysilsesquioxane with a rigid three-dimensional structure, which greatly improves the hardness of the existing high-temperature resistant coating and solves the problem of low scratch resistance of the coating And the problem of poor stability under high temperature of the existing high temperature resistant coating. On the other hand, polysilsesquioxane reacts with the surface groups of inorganic pigments and fillers, which effectively inhibits the agglomeration of pigments and fillers and improves the dispersibility of pigments and fillers. In particular, the chemical crosslinking reaction between the organic resin and polysilsesquioxane also greatly improves the compatibility between the resin and the inorganic pigments and fillers, thereby further improving the compactness of the coating, thereby improving the high temperature resistance of the coating. The high crack resistance effectively reduces the problem of cracks in the coating under high temperature.

In a word, compared with the prior art, the advantages of the present invention include: it can further improve the quality of the high-temperature-resistant coating, and effectively improve the overall performance of the coating, especially the hardness, stability, and Scratch resistance, compactness and crack resistance, so it has good application prospects.

Detailed ways

In view of the deficiencies in the prior art, the inventor of this case was able to propose the technical solution of the present invention after long-term research and extensive practice. The technical solution, its implementation process and principle will be further explained in conjunction with several embodiments as follows.

Example 1

(1) Feed trimethylsilyl clathrate polysilsesquioxane and polyetheretherketone resin into the reactor at a mass ratio of 1:5, and add 0.15% of catalyst tetramethylhydrogen according to the total mass of the reaction system Amine oxide and toluene accounting for 20% of the total mass of the resin are uniformly mixed; reacted at 45°C for 4 hours to obtain an organic resin modified with silsesquioxane;

(2) Place cobalt black and mica respectively in an ethanol solution containing 1% (unless specified below, all are wt%) of coupling agent KH550, reflux and stir for 0.5h at a temperature of 40°C, and then cool , filter, and dry for later use.

(3) Mix the trimethylsilyl clathrate polysilsesquioxane with the pigment, filler, and toluene obtained in step (2) at a ratio of 1:5:6, and carry out a reflux reaction at a temperature of 40°C for 2 hours , and then cooled for later use.

(4) Mix the adhesion promoter 7130 with epoxy group, silane coupling agent KH550, and xylene at a ratio (mass ratio) of 1:1:1 to prepare a compounding aid.

(5) Prepare high-temperature-resistant coatings according to the following formula, disperse and mix evenly: modified organic resin 15%; modified pigment and filler 45%; BYK-164 dispersant 5%; BYK-313 leveling agent 1%; compound additive 1 %; toluene 10%. Apply the paint to the base material and cure it at 250°C for 1 hour, and then measure the hardness after calcination at 400°C for 1 hour, which is 4H. The coating has a small amount of cracks under the SEM electron microscope, and the length is between 1 and 3 microns.

Example 2

(1) Feed tetramethylammonium clathrate polysilsesquioxane and fluorocarbon resin in the reaction kettle at a mass ratio of 1:7, and add 0.2% catalyst tetrabutylammonium hydroxide and accounted for by the total mass of the reaction system Xylene with 20% of the total mass of the resin, uniformly mixed; reacted at 55°C for 2.5 hours to obtain an organic resin modified with silsesquioxane;

(2) Place copper chromium black and barium sulfate in ethanol solution containing 3% coupling agent KH560 respectively, reflux and stir at 50°C for 1 hour, then cool, filter, and dry for later use.

(3) Mix the tetramethylammonium clathrate polysilsesquioxane with the pigment, filler, and xylene obtained in step (2) in a ratio of 1:6:8, and carry out reflux reaction at a temperature of 50°C 1.5h, then cooled for later use.

(4) Mix the adhesion promoter HSM-900 with epoxy group, the silane coupling agent KH560, and xylene in a ratio of 1:3:1 to prepare a composite auxiliary agent.

(5) Prepare high-temperature resistant coatings according to the following formula, disperse and mix evenly: 20% modified organic resin; 50% modified pigment and filler; 3% BYK-174 dispersant; 0.1% BYK-300 leveling agent; %; ethyl acetate 8%. Apply the paint to the base material and cure it at 150°C for 1 hour, and then measure the hardness after calcination at 400°C for 1 hour, which is 3H. The coating has almost no cracks under the SEM electron microscope.

Example 3

(1) Feed dimethyl-diphenyl-methylvinyl polysilsesquioxane and silicone resin into the reactor at a mass ratio of 1:8, and add 0.25% of catalyst three by the total mass of the reaction system Ethanolamine and toluene accounting for 20% of the total mass of the resin are uniformly mixed; reacted at 60° C. for 2.5 hours to obtain an organic resin modified with silsesquioxane;

(2) Place red iron oxide and quartz powder in ethanol solution containing 5% coupling agent KH570, reflux and stir at 60°C for 1 hour, then cool, filter, and dry for later use.

(3) Mix dimethyl-diphenyl-methylvinyl polysilsesquioxane with the pigment, filler, and xylene obtained in step (2) at a ratio of 1:8:9, and heat the mixture at a temperature of 65°C The reflux reaction was carried out under the conditions for 1.5h, and then cooled for later use.

(4) Mix the adhesion promoter D-6040 with epoxy group, silane coupling agent KH550, and xylene at a ratio of 1:5:1 to prepare a compounding aid.

(5) Prepare high-temperature resistant coatings according to the following formula, disperse and mix evenly: 25% modified organic resin; 30% modified pigment and filler; 1% Silok-714 dispersant; 1.5% DC-57 leveling agent; %; Butyl acetate 3%. Apply the paint to the base material and cure it at 300°C for 1 hour, and then measure the hardness after calcination at 400°C for 1 hour, which is 4H. The coating has no cracks under the SEM electron microscope.

Example 4

(1) Dimethylsilyl clathrate polysilsesquioxane and polyimide resin are fed into the reactor at a mass ratio of 1:10, and 0.15% of the catalyst triethylene diethylene glycol by the total mass of the reaction system is added. Amine neutralizes 10% of toluene and 10% of xylene accounting for the total mass of the resin; react at 80°C for 2 hours to obtain a modified organic resin containing silsesquioxane;

(2) Put zirconia and mica respectively in ethanol solution containing 8% coupling agent KH590, reflux and stir at 80°C for 0.5h, then cool, filter, and dry for later use.

(3) Mix dimethylsilyl clathrate polysilsesquioxane with pigments and fillers obtained in step (2) and toluene solvent at a ratio of 1:10:11, and carry out reflux reaction at a temperature of 50°C for 2 hours , and then cooled for later use.

(4) Mix the adhesion promoter D-6040 with epoxy group, silane coupling agent KH560, and xylene in a ratio of 1:2:1 to prepare a compounding aid.

(5) Prepare high-temperature-resistant coatings according to the following formula, disperse and mix evenly: 30% modified organic resin; 25% modified pigment and filler; 4% BYK-174 dispersant; 3% Silok-8100 leveling agent; compound additive 3 %; naphtha 20%. Apply the paint to the base material and cure it at 200°C for 1 hour, and then measure the hardness after calcination at 400°C for 1 hour, which is 3H. The coating has no cracks under the SEM electron microscope.

Comparative example 1:

Mix according to the formula of step (5) in the above-mentioned 4 examples to prepare high-temperature-resistant coatings, but the resins and pigments and fillers used are all raw materials that have not been modified by polysilsesquioxane, and then the coatings are applied to the base After the materials are cured according to the curing temperature in the examples, the hardness after calcination at 400°C for 1 hour is measured to be less than or equal to 1H. There are many cracks in the coating under the SEM electron microscope, and the lengths are all above 10 microns.

Comparative example 2:

Mix according to the formula of step (5) in the above 4 examples to prepare high-temperature resistant coatings, but use resin modified by polysilsesquioxane, and the pigments and fillers are not modified, and then apply the coating on the substrate After curing according to the curing temperature in the example, the hardnesses after calcination at 400° C. for 1 hour are measured to be 2H, 1H, 2H, and 1H, respectively. The coating has many cracks under the SEM electron microscope, and the length is between 3 and 9 microns.

Comparative example 3:

Mix according to the formula of step (5) in the above four examples to prepare high temperature resistant coatings, but use polysilsesquioxane modified pigments and fillers, and the resin is not modified, and then apply the coating to the substrate After curing according to the curing temperature in the above example, the hardness after calcination at 400°C for 1 hour is measured to be 1H, 1H, 2H, and 1H respectively. The coating has many cracks under the SEM electron microscope, and the length is between 3 and 9 microns.

It can be seen from the above-mentioned hardness value after high-temperature calcination and the occurrence of cracks at high temperature that the performance of the high-temperature-resistant coating prepared by using the treated resin and pigments and fillers is significantly improved.

It should be noted that the various products and related parameters, various reaction participants and process conditions used in the above examples are all typical examples, but after a large number of experiments by the inventor of this case, the other listed above Different types of reaction participants and other process conditions are also applicable, and all can achieve the claimed technical effect of the present invention.

It should be understood that the above-mentioned embodiments are only to illustrate the technical concept and features of the present invention, the purpose of which is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and not to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention shall fall within the protection scope of the present invention.

Claims (10)

1. A modified high temperature resistant coating based on polysilsesquioxane, characterized in that it comprises: Modified organic resins selected from organic resins modified by polysilsesquioxanes, Modified pigments and fillers, including pigments and/or fillers modified by polysilsesquioxanes, You can choose to add or not add coalescents, And, you can choose to add or not add solvent; Moreover, at least one component in the high temperature resistant coating is fluid, and the at least one component can be uniformly mixed with other components in the high temperature resistant coating to form the high temperature resistant coating in a fluid state. 2. the high temperature resistant coating based on polysilsesquioxane modification according to claim 1, is characterized in that: The high temperature resistant coating includes 15wt%-30wt% modified organic resin; Preferably, the organic resin includes any one or a combination of two or more of polyether ether ketone resins, fluorocarbon resins, polyphenylene sulfide resins, silicone resins, and polyimide resins; And/or, the high temperature resistant coating includes 25wt%-50wt% modified pigments and fillers; Preferably, the pigment includes any one or both of carbon black, cobalt black, cobalt blue, cobalt green, copper chrome black, titanium nickel yellow, titanium white, cadmium red, titanium chrome brown, iron oxide red, and zirconia. more than one combination; Preferably, the filler includes any one or a combination of two or more of calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, wollastonite, mica, and quartz powder; Preferably, the mass ratio of the pigment to the filler is 2:1˜1:3. 3. the high temperature resistant coating based on polysilsesquioxane modification according to claim 1, is characterized in that: The film-forming aids include any one or a combination of two or more of dispersants, leveling agents, and compounding aids; Preferably, the high temperature resistant coating includes: dispersant 1wt%-5wt%, leveling agent 0.1wt%-3wt%, compounding additive 0.2wt%-3wt%; Preferably, the dispersant includes polyamides, fatty acid polyalcohol esters or silicone dispersants; Preferably, the leveling agent includes acrylate, urea-formaldehyde resin or silicone resin leveling agent; Preferably, the composite auxiliary agent includes a polymer adhesion promoter with an epoxy group and a silane coupling agent with an amino or epoxy group at a mass ratio of 1:1 to 1:5. 4. The high temperature resistant coating based on polysilsesquioxane modification according to claim 1, characterized in that it also includes 3wt%～20wt% solvent; Preferably, the solvent includes any one or a combination of two or more of benzene, toluene, xylene, n-hexane, dioxane, DBE, naphtha, ethyl acetate or butyl acetate. 5. according to the described polysilsesquioxane modified high-temperature resistant coating based on claim 1, it is characterized in that the chemical general formula of described polysilsesquioxane is (RSiO _3/2 )n; Wherein, if R If it is a reactive group, the R group includes any one or a combination of two or more of alkenyl, epoxy or amino groups; if R is an inert group, then the R group includes C1-C4 alkyl Any one or a combination of two or more of radical, alkylene or aryl; n is any integer within 20-40. 6. according to claim 1,2 or 5 described based on polysilsesquioxane modified high temperature resistant coating, it is characterized in that the preparation method of described modified organic resin comprises: polysilsesquioxane and organic resin Feed materials at a mass ratio of 1:5 to 1:10, add a catalyst and an organic solvent, mix evenly, and react at 45 to 85°C for 2 to 4 hours to obtain a modified organic resin containing silsesquioxane; Preferably, the amount of the catalyst is 0.15% to 0.3% of the total mass of the modified organic resin preparation reaction system; Preferably, the amount of the organic solvent is 20% of the mass of the organic resin; Preferably, the catalyst includes tetramethylammonium hydroxide, tetrabutylammonium hydroxide, tetrabutylphosphonium acetate, triethanolamine, triphenylphosphine, benzyldimethylamine, dibutyltin dilaurate, triethylene Any one or a combination of two or more of the base diamines; Preferably, the organic solvent includes toluene and/or xylene. 7. according to claim 1 based on polysilsesquioxane modified high temperature resistant coating, it is characterized in that the preparation method of described modified pigment and filler comprises: Disperse the pigments and fillers in the coupling agent solution, reflux and stir for 0.5h-2h at a temperature of 40°C to 80°C, then separate the crude pigments and fillers, and then mix polysilsesquioxane and crude pigments The filler and the organic solvent are mixed at a mass ratio of 1:5:6 to 1:10:11, and then reflux reaction is carried out at a temperature of 40°C to 85°C for 0.5h to 2h to obtain the modified pigment and filler; Preferably, the coupling agent solution is selected from ethanol solutions with a concentration of 1wt% to 10wt% coupling agent; Preferably, the coupling agent includes any one or a combination of two or more of KH550, KH560, KH570 or KH590; Preferably, the organic solvent includes toluene and/or xylene. 8. A high temperature resistant coating, mainly formed by curing the high temperature resistant coating based on polysilsesquioxane modification according to any one of claims 1-7. 9. A preparation method for a high-temperature-resistant coating, characterized in that it comprises: coating the high-temperature-resistant coating based on polysilsesquioxane modification described in any one of claims 1-7 on a substrate, The coating is then cured at a temperature of 150° C. to 300° C. to form the coating. 10. A device characterized by comprising the high temperature resistant coating according to claim 8.