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

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

A kind of high temperature ablation heat insulation coating and preparation method thereof

technical field

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

Background technique

During flight, the spacecraft interacts with the air to generate aerodynamic heating, which can easily lead to the decline of the mechanical properties of the aircraft shell. At the same time, under the condition of aerodynamic heating, the temperature in the aircraft cabin will increase, which will easily lead to damage to the precision instruments in the cabin. High thermal protection efficiency, simple construction, low cost and other reasons are often used for thermal protection of the outer surface of space vehicles to ensure their flight safety.

With the development of space vehicle technology, a new generation of aircraft has higher maneuverability, stronger precision strike, and better penetration capability. The aircraft flies faster and the flight time in the atmosphere increases significantly. The heat flow environment faced is more severe, which is mainly characterized by high shear and long-term high heat flow. This places higher requirements on the high temperature resistance and high temperature shear resistance of ablative thermal insulation coatings. On the other hand, in addition to the ablation and heat insulation properties, the coating also needs to have "three defenses" properties, high and low temperature resistance and other requirements to meet the requirements of the production, transportation, storage and service environment of space vehicles.

The ablative thermal insulation coating based on epoxy resin has the characteristics of high ablation efficiency, good adhesion performance and low cost. Protection, thermal protection of launch ground facilities, thermal protection of petroleum and chemical pipelines and many other fields.

After retrieval, the publication number is CN107652827B, which discloses "a kind of anti-thermal insulation coating and its preparation method". The matrix of the anti-thermal insulation coating is organosilicon modified phenolic resin. The bonding strength between the resin and the coated substrate is low; the curing temperature is 120°C, the curing temperature is high, and the construction process is complicated. The gas flow ablation and scouring at 1000-1200 ℃ lasts for 200s, which cannot meet the long-term requirements of high-speed and large-range flight periods; the publication number is CN111732871A, which discloses "a light-weight high heat-resistant coating and its preparation method". The curing temperature of the thermal insulation coating is 120 ℃ - 150 ℃, the curing temperature is high, can not meet the room temperature curing, and the construction process is complicated; the publication number is CN109536015 discloses "a heat protection coating and its preparation method", the heat protection coating is A silicone rubber heat-resistant coating, suitable for use in aerodynamic environments with a shear force of more than 1200Pa, the ablation amount in 130s is less than 1mm, which cannot meet high shear (shear strength ≥3MPa) and long-term (≥250s) high Long-term requirements for high-speed and long-range flight periods of heat flow.

However, the epoxy resin-based thermal protective coating has poor toughness, and the coating is easy to crack in the service environment, especially in the high and low temperature alternating environment; the resin has low temperature resistance, and the coating has a fast high temperature ablation and pyrolysis rate; Problems such as poor performance and easy ablative peeling cannot meet the needs of the new generation of aircraft for ablative thermal insulation coatings. Therefore, it is urgent to develop new epoxy-based ablative thermal insulation coating materials to meet the thermal protection needs of the new generation of space vehicles.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a high-temperature ablation heat-insulating paint and a preparation method thereof, so as to solve the problems raised in the above-mentioned background technology.

In order to achieve the above purpose, the present invention provides the following technical solutions: a high-temperature ablation-resistant heat-insulating paint, the high-temperature ablation-resistant heat insulating paint comprises the following components by mass percentage: hyperbranched polymer 30%-40%, Modified acrylic emulsion 3%-9%, talc 1%-2%, diatomaceous earth 1%-2%, epoxy resin 20%-30%, epoxy silicone resin 3%-5%, reactive diluent 5%-10%, curing agent 10%-15%, flame retardant 10%-20%, reinforcing component 10%-25%, ceramicizing component 2%-5% and anti-settling component 2%-4 %, the hyperbranched polymer is any one or more of hydroxyl-terminated hyperbranched polyester, carboxyl-terminated hyperbranched polyester, hyperbranched epoxy, and hyperbranched silicone resin, and the epoxy resin is E51, Any one or more of E44, E20, NPPN-631, and NPPN-638 epoxy resins, the epoxy silicone resin has an epoxy equivalent weight of 500-800 g/eq and a viscosity of 3000-7000cp@25°C.

Preferably, the ratio of the talc to the diatomaceous earth is 1:1.

Preferably, the active diluent is ethylene glycol diglycidyl ether, 1,4 butanediol diglycidyl ether, 1,4 cyclohexane dimethanol diglycidyl ether, and carbon 12-14 alkyl glycidyl ether , any one or more of hexanediol diglycidyl ether and pentanediol diglycidyl ether.

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

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

Preferably, the reinforcing components are short phenolic fibers with a length of 0.5-1.5 mm, carbon fibers with a length of 0.5-1.5 mm, diynyl aromatic hydrocarbon balls with a diameter of 20-100 μm, carbon fiber reinforced polysilane aryne resin balls with a diameter of 20-100 μm or a diameter of 20 μm. - Any one or more of 100 μm glass fiber reinforced polysilane aryne resin balls.

Preferably, the ceramic components are Al-coated SiO2 microspheres with a diameter of 20-100 μm, ammonium polyphosphate, glass powder, mica powder, talc powder, kaolin, 3-100 nm nano-alumina, titanium boride, potassium feldspar powder any one or more.

Preferably, the anti-settling agent is any one or more of organoboronite, BYK-410 and BYK-431.

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

S1, weigh hyperbranched polymer, talc, diatomite, epoxy resin, epoxy silicone resin, flame retardant, reinforcing component, ceramizing component and anti-settling component according to the formula ratio;

S2. Preliminarily mix the weighed ingredients, put them into the mixer and inject water at the same time, set the stirring speed to 1500-1800r/min, stir to a uniform state, and make semi-finished products;

S3. Pour the obtained semi-finished product into a three-roll mill for grinding, set the grinding time to 5-12 min, and perform discharging and filling after grinding to obtain a filling semi-finished product;

S4. Add the curing agent, modified acrylic emulsion and reactive diluent in the proportion of the formula to the filling semi-finished product, and place it in the mixer again for stirring until it is uniform;

S5. After the coating is prepared, spray it to the specified thickness, and finally cure it at room temperature or put it in an oven for 4 hours at 60-70 °C to obtain a high-temperature ablation-resistant thermal insulation coating.

Compared with the prior art, the beneficial effects of the present invention are:

By using hyperbranched polymer, epoxy resin and epoxy silicone resin as the main raw materials, and using modified acrylic emulsion and diatomite as auxiliary raw materials, the thermal insulation properties of the overall ablative thermal insulation coating can be improved. The ablative thermal insulation coating prepared by the formula and the preparation method of the invention has the functional characteristics of high bonding strength, high toughness and high temperature resistance.

Detailed ways

The present invention provides a technical solution: a high temperature ablation and heat insulation coating, each component is calculated by mass percentage as follows: hyperbranched polymer 30%-40%, modified acrylic emulsion 3%-9%, talc powder 1%-2%, diatomite 1%-2%, epoxy resin 20%-30%, epoxy silicone resin 3%-5%, reactive diluent 5%-10%, curing agent 10%-15 %, flame retardant 10%-20%, reinforcing component 10%-25%, ceramicizing component 2%-5% and anti-settling component 2%-4%, the hyperbranched polymer is hydroxyl-terminated hyperbranched Any one or more of polyester, carboxyl-terminated hyperbranched polyester, hyperbranched epoxy, and hyperbranched silicone resin, the epoxy resin is E51, E44, E20, NPPN-631, NPPN-638 ring Any one or more of the oxygen resins, the epoxy equivalent of the epoxy silicone resin is 500-800 g/eq, and the viscosity is 3000-7000cp@25°C.

Wherein, the ratio of described talc and diatomite is 1:1.

Wherein, the active diluent is ethylene glycol diglycidyl ether, 1,4 butanediol diglycidyl ether, 1,4 cyclohexane dimethanol diglycidyl ether, carbon 12-14 alkyl glycidyl ether, Any one or more of hexanediol diglycidyl ether and pentanediol diglycidyl ether.

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

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

The reinforcing components are short phenolic fibers with a length of 0.5-1.5 mm, carbon fibers with a length of 0.5-1.5 mm, diynyl aromatic hydrocarbon balls with a diameter of 20-100 μm, carbon fiber reinforced polysilane aryne resin balls with a diameter of 20-100 μm or a diameter of 20-100 μm. Any one or more of 100 μm glass fiber reinforced polysilane aryne resin balls.

Wherein, the ceramization component is a medium of Al-coated SiO2 microspheres with a diameter of 20-100 μm, ammonium polyphosphate, glass powder, mica powder, talc powder, kaolin, 3-100 nm nano-alumina, titanium boride, potassium feldspar powder any one or more.

Wherein, the anti-settling agent is any one or more of organoboronite, BYK-410 and BYK-431.

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

S1, weigh hyperbranched polymer, talc, diatomite, epoxy resin, epoxy silicone resin, flame retardant, reinforcing component, ceramizing component and anti-settling component according to the formula ratio;

S2. Preliminarily mix the weighed ingredients, put them into the mixer and inject water at the same time, set the stirring speed to 1500-1800r/min, stir to a uniform state, and make semi-finished products;

S3. Pour the obtained semi-finished product into a three-roll mill for grinding, set the grinding time to 5-12 min, and perform discharging and filling after grinding to obtain a filling semi-finished product;

S4. Add the curing agent, modified acrylic emulsion and reactive diluent in the proportion of the formula to the filling semi-finished product, and place it in the mixer again for stirring until it is uniform;

S5. After the coating is prepared, spray it to the specified thickness, and finally cure it at room temperature or put it in an oven for 4 hours at 60-70 °C to obtain a high-temperature ablation-resistant thermal insulation coating.

Example 1. A high-temperature ablation heat-insulating coating, each component is calculated by mass percentage: 30% of hydroxyl-terminated hyperbranched polyester, 3% of modified acrylic emulsion, 1% of talc, 1% of diatomaceous earth , NPPN-638 epoxy resin 23%, epoxy silicone resin 3%, ethylene glycol diglycidyl ether 5%, aliphatic amine 10%, silica 10%, carbon fiber reinforced polysilane aryne resin ball 10%, Mica powder 2% and organoboronite 2%.

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

S1, weigh the hydroxyl-terminated hyperbranched polyester, talc, diatomaceous earth, NPPN-638 epoxy resin, epoxy silicone resin, silica, carbon fiber reinforced polysilane aryne resin balls, mica powder and Organoboronite;

S2. Preliminarily mix the weighed ingredients, put them into the mixer and inject water at the same time, set the stirring speed to 1500r/min, stir to a uniform state, and make semi-finished products;

S3. Pour the obtained semi-finished product into a three-roll mill for grinding, set the grinding time to 5 min, and perform discharging and filling after grinding to obtain a filling semi-finished product;

S4. Add the fatty amine, modified acrylic acid emulsion and ethylene glycol diglycidyl ether in the proportion of the formula to the filling semi-finished product, and place it in the mixer again for stirring, and stir to a uniform state;

S5. After the coating is prepared, spray it to the specified thickness, and finally cure it at room temperature or put it in an oven for 4 hours at 60°C to obtain a high-temperature ablation-resistant thermal insulation coating.

Example 2. A high-temperature ablation heat-insulating coating, each component is calculated by mass percentage: 31% of carboxyl-terminated hyperbranched polyester, 3% of modified acrylic emulsion, 1% of talc, 1% of diatomaceous earth , NPPN-631 epoxy resin 21%, epoxy silicone resin 4%, hexanediol diglycidyl ether 5%, alicyclic amine 10%, tetrabromobisphenol 10%, glass fiber reinforced polysilane aryne resin ball 10%, glass frit 2% and BYK-4102%.

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

S1, weigh the carboxyl-terminated hyperbranched polyester, talc, diatomaceous earth, NPPN-631 epoxy resin, epoxy silicone resin, tetrabromobisphenol, glass fiber reinforced polysilane aryne resin ball, glass fiber according to the formula proportion powder and BYK-410;

S2. Preliminarily mix the weighed ingredients, put them into a mixer and inject water at the same time, set the stirring speed to 1800r/min, stir to a uniform state, and make a semi-finished product;

S3. Pour the obtained semi-finished product into a three-roll mill for grinding, set the grinding time to 12 min, and perform discharging and filling after grinding to obtain a filling semi-finished product;

S4. Add alicyclic amine, modified acrylic acid emulsion and hexanediol diglycidyl ether in the proportion of the formula to the filling semi-finished product, and place it in a mixer again for stirring, and stir to a uniform state;

S5. After the coating is prepared, spray it to a specified thickness, and finally cure it at room temperature or put it in an oven for 4 hours at 70°C to obtain a high-temperature ablation-resistant thermal insulation coating.

Example 3. Taking the technical solution disclosed in CN107652827B as a comparative example of the present invention, an anti-heat-insulation coating is composed of silicone-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 organic bentonite, the mass ratios are 35%: 10%: 12%: 18%: 15%: 10% respectively.

Its preparation method is:

The first step is to weigh hollow ceramic microspheres (particle size 601m-100um), barium metaborate (300 mesh), vermiculite powder (density 200kg/m), ammonium polyphosphate APP1000 and organic bentonite with an electronic balance. 10%: 12%: 18%: 15%: 10%, respectively, the weighing mass is 100g: 120g: 180g _: 150g: 100g;

In the second step, the five kinds of powders are preliminarily mixed and baked in an oven at 60°C for more than 4 hours;

The third step is to weigh 350g of silicone-modified phenolic resin with an electronic balance;

In the fourth step, the dried powder is added to the organosilicon modified phenolic resin, and acetone is added in a small amount for many times and continuously stirred and kneaded to prepare a semi-finished paint;

The 5th step, the above-mentioned coating semi-finished product is filtered through a 10o mesh sieve, and the residue, agglomeration, etc. remaining on the sieve are ground and pulverized and filtered into the coating;

The sixth step, adding an appropriate amount of acetone to modulate the above coating into a viscosity of 16-22s (measured with -4 cups);

After the heat-resistant paint is prepared, spray the prepared paint on the surface of the clean parts with an ordinary pneumatic spray gun (sandblasting or grinding can be performed), the spraying pressure is 0.2-0.4MPa, and the distance between the spray gun and the surface of the part is 200-300mm, and each pass The thickness of spraying is controlled to 0.1-0.2mm. After the first spraying is completed, it is left to dry for 60 minutes at room temperature, and then the second spraying is carried out. After drying for 60 minutes, the spraying is repeated. ±0.2mm, and finally put the parts into the oven, bake at 120 ℃ for 4 hours, and the coating is cured and formed.

Embodiments 1 and 2 of the present invention and the comparative example were subjected to the measurement of thermal conductivity and thermal reflectivity, and the measurement results were as follows:

It can be seen from the data shown in the above table that the thermal insulation performance of the embodiment of the present invention is better than that of the comparative example.

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

Claims (9)

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:

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 to be 1500-1800r/min, and stirring the components 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 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.