CN114621657A

CN114621657A - High-temperature ablation-resistant heat-insulating coating and preparation method thereof

Info

Publication number: CN114621657A
Application number: CN202210237607.6A
Authority: CN
Inventors: 杜建华; 刘静; 董高军; 王石磊
Original assignee: Taizhou Lanjian New Material Co ltd
Current assignee: Taizhou Lanjian New Material Co ltd
Priority date: 2022-03-11
Filing date: 2022-03-11
Publication date: 2022-06-14

Abstract

The invention discloses a high-temperature ablation resistant heat insulation coating and a preparation method thereof, wherein the high-temperature ablation resistant heat insulation coating comprises the following components in percentage by mass: 30-40% of hyperbranched polymer, 3-9% of modified acrylic emulsion, 1-2% of talcum powder, 1-2% of diatomite, 20-30% of epoxy resin, 3-5% of epoxy organic silicon resin, 5-10% of reactive diluent, 10-15% of curing agent, 10-20% of flame retardant, 10-25% of reinforcing component, 2-5% of ceramic component and 2-4% of anti-settling component, wherein the hyperbranched polymer is any one or more of hydroxyl-terminated hyperbranched polyester, carboxyl-terminated hyperbranched polyester, hyperbranched epoxy and hyperbranched organic silicon resin, and the invention has the beneficial effects that: by adopting the hyperbranched polymer, the epoxy resin and the epoxy organic silicon resin as main raw materials and the modified acrylic emulsion and the diatomite as auxiliary raw materials, the heat preservation and insulation characteristics of the overall ablative insulation coating can be improved, and meanwhile, the ablative insulation coating prepared by adopting the formula and the preparation method provided by the invention has the functional characteristics of high bonding strength, high toughness and high temperature resistance.

Description

High-temperature ablation-resistant heat-insulating coating and preparation method thereof

Technical Field

The invention relates to the technical field of heat insulation coatings, in particular to a high-temperature ablation-resistant heat insulation coating and a preparation method thereof.

Background

The space vehicle is pneumatically heated under the action of air during flying, so that the mechanical property of the shell of the space vehicle is easily reduced, meanwhile, under the condition of pneumatic heating, the temperature in the cabin of the space vehicle is increased, so that precision instruments in the cabin are easily damaged, and the ablation heat-insulating coating is commonly used for thermal protection of the outer surface of the space vehicle due to the reasons of high heat-proof efficiency, simple and convenient construction, low cost and the like, so that the flying safety of the space vehicle is guaranteed.

With the development of spacecraft technology, the new generation of aircrafts have higher maneuverability, stronger accurate hit performance and more excellent penetration capability, and the aircrafts have higher flight speed and obviously increased flight time in the atmosphere. The heat flux environment encountered is much more severe, which is mainly characterized by high shear and long term high heat flux. The high-temperature-resistant and high-temperature-shear-resistant ablative heat-insulating coating has higher requirements. On the other hand, besides ablation heat-insulating property, the coating also needs to have the requirements of three prevention, high and low temperature alternation resistance and the like so as to meet the requirements of the production, transportation, storage and service environment of the spacecraft.

The ablation heat-insulating coating taking the epoxy resin as the matrix is used as an ablation-resistant heat-insulating functional coating because of the characteristics of high ablation efficiency, good adhesive property and low cost, and is widely applied to various fields of thermal protection of the outer surface of a space vehicle, thermal protection of launching ground facilities, thermal protection of petroleum and chemical pipelines and the like.

Through retrieval, publication No. CN107652827B discloses 'an anti-heat insulation coating and a preparation method thereof', the matrix of the anti-heat insulation coating is organic silicon modified phenolic resin, and compared with an epoxy resin matrix, the bonding strength of the organic silicon modified phenolic resin and the coated matrix is low; the curing temperature is 120 ℃, the curing temperature is high, and the construction process is complex. The burning and scouring are carried out by the fuel gas flow at 1000-; the publication No. CN111732871A discloses 'a light high-heat-proof coating and a preparation method thereof', the curing temperature of the heat-proof coating is 120-150 ℃, the curing temperature is high, the room-temperature curing cannot be met, and the construction process is complex; the publication No. CN109536015 discloses a heat-proof coating and a preparation method thereof, the heat-proof coating is a silicon rubber heat-proof coating which is suitable for being used in a pneumatic environment with a shearing force of more than 1200Pa, the 130s ablation amount is less than 1mm, and the long-term requirements of high shearing (the shearing strength is more than or equal to 3MPa) and long-term (more than or equal to 250s) high heat flow high-speed large-range flight period cannot be met.

However, the epoxy resin-based thermal protection coating has poor toughness, and the coating is easy to crack in a service environment, particularly in a high-temperature and low-temperature alternating environment; the resin has low temperature resistance, and the coating has high ablation and pyrolysis speed at high temperature; the problems of poor high-temperature shearing resistance, easy ablation and peeling and the like cannot meet the requirement of a new generation of aircrafts on ablation heat-insulating coatings, so that the development of novel epoxy ablation heat-insulating coating materials is urgently needed to meet the heat protection requirement of the new generation of space aircrafts.

Disclosure of Invention

The invention aims to provide a high-temperature ablation-resistant heat-insulating coating and a preparation method thereof, so as to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme of a high-temperature ablation resistant heat insulation coating, which comprises the following components in percentage by mass: 30-40% of hyperbranched polymer, 3-9% of modified acrylic emulsion, 1-2% of talcum powder, 1-2% of diatomite, 20-30% of epoxy resin, 3-5% of epoxy organic silicon resin, 5-10% of reactive diluent, 10-15% of curing agent, 10-20% of flame retardant, 10-25% of reinforcing component, 2-5% of ceramic component and 2-4% of anti-settling component, wherein the hyperbranched polymer is any one or more of hydroxyl-terminated hyperbranched polyester, carboxyl-terminated hyperbranched polyester, hyperbranched epoxy and hyperbranched organic silicon resin, the epoxy resin is any one or more of E51, E44, E20, NPPN-631 and NPPN-638 epoxy resin, and the epoxy equivalent weight of the epoxy organic silicon resin is 500-, the viscosity was 3000-7000cp @25 ℃.

Preferably, the ratio of the talcum powder to the diatomite is 1: 1.

Preferably, the reactive diluent is any one or more of ethylene glycol diglycidyl ether, 1, 4-butanediol diglycidyl ether, 1, 4-cyclohexanedimethanol diglycidyl ether, C12-14 alkyl glycidyl ether, hexanediol diglycidyl ether, and pentanediol diglycidyl ether.

Preferably, the curing agent is any one or more of aliphatic amine, alicyclic amine, polyamide, polyether amine and cashew nut shell oil modified amine.

Preferably, the flame retardant is one or more of white carbon black, tetrabromobisphenol, decabromodiphenylethane, tricresyl phosphate, aluminum diethylphosphinate, ZB flame retardant, antimony trioxide and silicone resin.

Preferably, the reinforcing component is any one or more of phenolic short fibers with the length of 0.5-1.5mm, carbon fibers with the length of 0.5-1.5mm, dialkynyl aromatic hydrocarbon spheres with the diameter of 20-100 mu m, carbon fiber reinforced polysilane aryne resin spheres with the diameter of 20-100 mu m or glass fiber reinforced polysilane aryne resin spheres with the diameter of 20-100 mu m.

Preferably, the ceramic component is any one or more of SiO2 microspheres coated with 20-100 mu mAl of diameter, ammonium polyphosphate, glass powder, mica powder, talcum powder, kaolin, 3-100nm nano alumina, titanium boride and potassium feldspar powder.

Preferably, the anti-settling agent is any one or more of organic boron moist soil, BYK-410 and BYK-431.

The preparation method of the high-temperature ablation-resistant heat-insulating coating comprises the following steps:

s1, weighing the hyperbranched polymer, the talcum powder, the diatomite, the epoxy resin, the epoxy organic silicon resin, the flame retardant, the reinforcing component, the ceramic component and the anti-settling component according to the formula proportion;

s2, preliminarily mixing the weighed components, putting the components into a stirrer, injecting water into the stirrer at the same time, setting the stirring speed at 1500-1800r/min, and stirring the components to a uniform state to obtain a semi-finished product;

s3, pouring the obtained semi-finished product into a three-roller grinding machine for grinding, setting the grinding time to be 5-12min, discharging after grinding is finished, and filling to obtain a filled semi-finished product;

s4, adding the curing agent, the modified acrylic emulsion and the reactive diluent into the filled semi-finished product according to the formula ratio, placing the mixture into the stirrer again for stirring, and stirring the mixture to be in a uniform state;

s5, after the coating is prepared, spraying the coating to a specified thickness, and finally curing at room temperature or continuously baking for 4 hours in an oven at 60-70 ℃ to obtain the high-temperature ablation-resistant heat-insulating coating.

Compared with the prior art, the invention has the beneficial effects that:

by adopting the hyperbranched polymer, the epoxy resin and the epoxy organic silicon resin as main raw materials and the modified acrylic emulsion and the diatomite as auxiliary raw materials, the heat preservation and insulation characteristics of the overall ablative insulation coating can be improved, and meanwhile, the ablative insulation coating prepared by adopting the formula and the preparation method provided by the invention has the functional characteristics of high bonding strength, high toughness and high temperature resistance.

Detailed Description

The invention provides a technical scheme that: the high-temperature ablation-resistant heat-insulating coating comprises the following components in percentage by mass: 30-40% of hyperbranched polymer, 3-9% of modified acrylic emulsion, 1-2% of talcum powder, 1-2% of diatomite, 20-30% of epoxy resin, 3-5% of epoxy organic silicon resin, 5-10% of reactive diluent, 10-15% of curing agent, 10-20% of flame retardant, 10-25% of reinforcing component, 2-5% of ceramic component and 2-4% of anti-settling component, wherein the hyperbranched polymer is any one or more of hydroxyl-terminated hyperbranched polyester, carboxyl-terminated hyperbranched polyester, hyperbranched epoxy and hyperbranched organic silicon resin, the epoxy resin is any one or more of E51, E44, E20, NPPN-631 and NPPN-638 epoxy resin, and the epoxy equivalent weight of the epoxy organic silicon resin is 500-, the viscosity was 3000-7000cp @25 ℃.

Wherein the ratio of the talcum powder to the diatomite is 1: 1.

Wherein the reactive diluent is any one or more of ethylene glycol diglycidyl ether, 1, 4 butanediol diglycidyl ether, 1, 4 cyclohexanedimethanol diglycidyl ether, C12-14 alkyl glycidyl ether, hexanediol diglycidyl ether and pentanediol diglycidyl ether.

Wherein the curing agent is any one or more of aliphatic amine, alicyclic amine, polyamide, polyether amine and cashew nut shell oil modified amine.

Wherein the flame retardant is one or a combination of more of white carbon black, tetrabromobisphenol, decabromodiphenylethane, tricresyl phosphate, aluminum diethylphosphinate, ZB flame retardant, antimony trioxide and silicone resin.

Wherein the reinforcing component is any one or more of phenolic short fibers with the length of 0.5-1.5mm, carbon fibers with the length of 0.5-1.5mm, dialkynyl aromatic hydrocarbon spheres with the diameter of 20-100 mu m, carbon fiber reinforced polysilane aryne resin spheres with the diameter of 20-100 mu m or glass fiber reinforced polysilane aryne resin spheres with the diameter of 20-100 mu m.

Wherein the ceramic component is any one or more of SiO2 microspheres coated with 20-100 mu mAl of diameter, ammonium polyphosphate, glass powder, mica powder, talcum powder, kaolin, 3-100nm nano alumina, titanium boride and potassium feldspar powder.

Wherein the anti-settling agent is any one or more of organic boron moist soil, BYK-410 and BYK-431.

Embodiment 1, a high temperature ablation resistant thermal insulation coating, comprising the following components in percentage by mass: 30% of hydroxyl-terminated hyperbranched polyester, 3% of modified acrylic emulsion, 1% of talcum powder, 1% of diatomite, 23% of NPPN-638 epoxy resin, 3% of epoxy organic silicon resin, 5% of ethylene glycol diglycidyl ether, 10% of fatty amine, 10% of white carbon black, 10% of carbon fiber reinforced polysilane aryne resin spheres, 2% of mica powder and 2% of organic boron-containing soil.

A preparation method of a high-temperature ablation-resistant heat-insulating coating comprises the following steps:

s1, weighing hydroxyl-terminated hyperbranched polyester, talcum powder, diatomite, NPPN-638 epoxy resin, epoxy organic silicon resin, white carbon black, carbon fiber reinforced polysilane aryne resin balls, mica powder and organic bentonite according to the formula proportion;

s2, preliminarily mixing the weighed components, putting the components into a stirrer, simultaneously injecting water, setting the stirring speed to be 1500r/min, and stirring to be uniform to prepare a semi-finished product;

s3, pouring the obtained semi-finished product into a three-roller grinding machine for grinding, setting the grinding time to be 5min, discharging and filling after grinding is finished, and obtaining a filled semi-finished product;

s4, adding the fatty amine, the modified acrylic emulsion and the ethylene glycol diglycidyl ether in the formula ratio into the filled semi-finished product, placing the mixture into the stirrer again for stirring, and stirring the mixture to be in a uniform state;

and S5, after the coating is prepared, spraying the coating to a specified thickness, and finally curing at room temperature or continuously baking for 4 hours in an oven at 60 ℃ to obtain the high-temperature ablation-resistant heat-insulating coating.

Embodiment 2 discloses a high-temperature ablation-resistant heat-insulating coating, which comprises the following components in percentage by mass: 31% of carboxyl-terminated hyperbranched polyester, 3% of modified acrylic emulsion, 1% of talcum powder, 1% of diatomite, 21% of NPPN-631 epoxy resin, 4% of epoxy silicone resin, 5% of hexanediol diglycidyl ether, 10% of alicyclic amine, 10% of tetrabromobisphenol, 10% of glass fiber reinforced polysilane aryne resin balls, 2% of glass powder and 2% of BYK-4102.

s1, weighing carboxyl-terminated hyperbranched polyester, talcum powder, diatomite, NPPN-631 epoxy resin, epoxy organic silicon resin, tetrabromobisphenol, glass fiber reinforced polysilane aryne resin balls, glass powder and BYK-410 according to the formula proportion;

s2, preliminarily mixing the weighed components, putting the components into a stirrer, simultaneously injecting water, setting the stirring speed to 1800r/min, and stirring to a uniform state to prepare a semi-finished product;

s3, pouring the obtained semi-finished product into a three-roller grinding machine for grinding, setting the grinding time to be 12min, discharging and filling after grinding is finished, and obtaining a filled semi-finished product;

s4, adding alicyclic amine, modified acrylic emulsion and hexanediol diglycidyl ether in the formula ratio into the filled semi-finished product, placing the mixture into the stirrer again, and stirring the mixture to be in a uniform state;

and S5, after the coating is prepared, spraying the coating to a specified thickness, and finally curing at room temperature or continuously baking in an oven at 70 ℃ for 4 hours to obtain the high-temperature ablation-resistant heat-insulating coating.

Example 3, the technical solution disclosed in CN107652827B is used as a comparative example of the present invention, and an anti-thermal insulation coating is composed of organosilicon modified phenolic resin, hollow ceramic microspheres (particle size 60 μm-100 μm), barium metaborate (300 mesh), vermiculite powder (density 200kg/m3), ammonium polyphosphate APP1000, and organobentonite, the mass ratio of which is 35%: 10%: 12%: 18%: 15%: 10 percent.

The preparation method comprises the following steps:

firstly, weighing hollow ceramic microspheres (with the particle size of 601-100 um), barium metaborate (300 meshes), vermiculite powder (with the density of 200kg/m), ammonium polyphosphate APP1000 and organic bentonite by using an electronic balance, wherein the mass ratio of the hollow ceramic microspheres to the organic bentonite is respectively 10%: 12%: 18%: 15%: 10%, and the weighed mass is respectively 100 g: 120 g: 180g_：150g：100g；

Secondly, the five powder materials are preliminarily mixed and put into a baking oven with the temperature of 60 ℃ for baking for more than 4 hours;

thirdly, weighing 350g of organic silicon modified phenolic resin by using an electronic balance;

fourthly, adding the dried powder into organic silicon modified phenolic resin, adding a small amount of acetone for multiple times, and continuously stirring and kneading to prepare a semi-finished paint product;

fifthly, filtering the semi-finished paint product through a 10-degree sieve, grinding and crushing residues, caking and the like on the sieve, and filtering the ground residues, caking and the like into the paint;

sixthly, adding a proper amount of acetone to adjust the coating to the viscosity of 16-22s (measured by coating 4 cups);

after the heat-proof coating is prepared, spraying the prepared coating on the surface of a clean part (capable of carrying out sand blasting or polishing treatment) by using a common pneumatic spray gun, wherein the spraying pressure is 0.2-0.4MPa, the distance between the spray gun and the surface of the part is 200 plus-minus 300mm, the spraying thickness of each time is controlled to be 0.1-0.2mm, airing for 60min under the normal temperature condition after the first spraying is finished, then carrying out second spraying, re-spraying after airing for 60min, repeating the spraying-airing process until the specified thickness reaches 2.0 +/-0.2 mm, finally putting the part into an oven, baking for 4h under the condition of 120 ℃, and finishing the curing and forming of the coating.

The thermal conductivity and thermal reflectance of inventive examples 1 and 2 and comparative examples were measured, and the results are shown in the following table:

as can be seen from the data presented in the above table, the thermal insulation performance of the examples of the present invention is superior to that of the comparative examples.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The high-temperature ablation-resistant heat-insulating coating is characterized by comprising the following components in percentage by mass: 30-40% of hyperbranched polymer, 3-9% of modified acrylic emulsion, 1-2% of talcum powder, 1-2% of diatomite, 20-30% of epoxy resin, 3-5% of epoxy organic silicon resin, 5-10% of reactive diluent, 10-15% of curing agent, 10-20% of flame retardant, 10-25% of reinforcing component, 2-5% of ceramic component and 2-4% of anti-settling component, wherein the hyperbranched polymer is any one or more of hydroxyl-terminated hyperbranched polyester, carboxyl-terminated hyperbranched polyester, hyperbranched epoxy and hyperbranched organic silicon resin, the epoxy resin is any one or more of E51, E44, E20, NPPN-631 and NPPN-638 epoxy resin, and the epoxy equivalent weight of the epoxy organic silicon resin is 500-, the viscosity was 3000-7000cp @25 ℃.

2. The high temperature ablation resistant thermal insulating coating of claim 1, characterized in that: the ratio of the talcum powder to the diatomite is 1: 1.

3. The high temperature ablation resistant thermal insulating coating of claim 1, characterized in that: the reactive diluent is any one or more of ethylene glycol diglycidyl ether, 1, 4-butanediol diglycidyl ether, 1, 4-cyclohexanedimethanol diglycidyl ether, C12-14 alkyl glycidyl ether, hexanediol diglycidyl ether and pentanediol diglycidyl ether.

4. The high temperature ablation resistant thermal insulating coating of claim 1, characterized in that: the curing agent is any one or more of aliphatic amine, alicyclic amine, polyamide, polyether amine and cashew nut shell oil modified amine.

5. The high temperature ablation resistant thermal insulating coating of claim 1, characterized in that: the flame retardant is one or more of white carbon black, tetrabromobisphenol, decabromodiphenylethane, tricresyl phosphate, aluminum diethylphosphinate, ZB flame retardant, antimony trioxide and silicone resin.

6. The high temperature ablation resistant thermal insulating coating of claim 1, characterized in that: the reinforcing component is any one or more of phenolic short fibers with the length of 0.5-1.5mm, carbon fibers with the length of 0.5-1.5mm, dialkynyl aromatic hydrocarbon spheres with the diameter of 20-100 mu m, carbon fiber reinforced polysilane aryne resin spheres with the diameter of 20-100 mu m or glass fiber reinforced polysilane aryne resin spheres with the diameter of 20-100 mu m.

7. The high temperature ablation resistant thermal insulating coating of claim 1, characterized in that: the ceramic component is any one or more of SiO2 microspheres coated with 20-100 mu mAl of diameter, ammonium polyphosphate, glass powder, mica powder, talcum powder, kaolin, 3-100nm nano alumina, titanium boride and potassium feldspar powder.

8. The high temperature ablation resistant thermal insulating coating of claim 1, characterized in that: the anti-settling agent is any one or more of organic boron moist soil, BYK-410 and BYK-431.

9. The preparation method of the high-temperature ablation-resistant heat-insulating coating according to claim 1, characterized in that: the method comprises the following steps:

s2, preliminarily mixing the weighed components, putting the components into a stirrer, injecting water into the stirrer at the same time, setting the stirring speed to be 1500-1800r/min, and stirring the components to a uniform state to prepare a semi-finished product;