CN114806295A

CN114806295A - Weather-proof heat insulation coating and heat insulation structure under high-temperature, high-humidity and high-salt environment

Info

Publication number: CN114806295A
Application number: CN202210276997.8A
Authority: CN
Inventors: 吴仲岿; 成保拓
Original assignee: Wuhan University of Technology WUT; Sanya Science and Education Innovation Park of Wuhan University of Technology
Current assignee: Wuhan University of Technology WUT; Sanya Science and Education Innovation Park of Wuhan University of Technology
Priority date: 2022-03-21
Filing date: 2022-03-21
Publication date: 2022-07-29

Abstract

The invention discloses a weather-proof heat insulation coating and a heat insulation structure in a high-temperature, high-humidity and high-salt environment. The heat insulation coating comprises the following components: water-based organic adhesive, heat insulation filler, heat insulation reinforcing fiber and coating auxiliary agent. Adopt adiabatic fibre as reinforcing material among this technical scheme for even if the content of silica aerogel reaches more than 15% in the coating, still do not take place the fracture after the coating solidification is dry, more importantly has better heat-proof quality under the high temperature and high humidity high salt environment, can be applicable to high temperature and high humidity high salt environment completely.

Description

Weather-proof heat insulation coating and heat insulation structure under high-temperature, high-humidity and high-salt environment

Technical Field

The application relates to the technical field of coatings, in particular to a heat insulation coating and a heat insulation structure which are resistant to weather in a high-temperature, high-humidity and high-salt environment.

Background

The heat insulation and preservation of buildings is an important method for saving energy and improving the living environment. The proportion of building energy consumption in the whole human energy consumption is generally 30-40%, and most of the building energy consumption is energy consumption of heating and air conditioning, so that the building energy saving significance is great. The common heat insulation means of the building is to spray or brush a layer of heat insulation coating on the periphery of the building, so that on one hand, the energy consumption of the building can be reduced, and on the other hand, the surface of a base body of the building can be protected to a certain extent.

There are three main types of thermal insulation coatings commonly used at present: reflective thermal insulation coating, radiant thermal insulation coating, and barrier thermal insulation coating. The function mechanism of the barrier type heat insulation coating is to add a filler with heat insulation and preservation functions into an organic or inorganic continuous phase. The silica aerogel becomes an ideal heat insulation functional filler because of the characteristics of small density, good heat insulation, high porosity and the like, and the silica aerogel is added into a coating system as the filler to prepare the silica aerogel composite coating, so that the heat insulation effect of the heat insulation coating can be greatly improved. The hollow glass microspheres are closed glass spheres and have a good reflection effect on sunlight, and the hollow glass microspheres are added into the coating, so that the reflection effect of the coating on the sunlight can be greatly improved, and the heat insulation effect is achieved.

The Hainan island belongs to tropical monsoon marine climate, the annual average temperature of 1780-2600 hours of sunshine hours is 22-27 ℃, and the Hainan island belongs to a high-heat area; the annual precipitation in Hainan is between 1000 mm and 2600 mm, the annual average precipitation is 1639 mm, and the high-humidity area belongs to; the salt fog atmosphere is easy to deposit in coastal areas, such as Wenchang area, and the Cl concentration is increased ^- The content of (A) is 0.056-0.225 mg/m ³ And at a high level nationwide. The high-temperature, high-humidity and high-salt environment of Hainan puts higher requirements on the heat-insulating property of the building coating.

Therefore, it is necessary to provide a heat insulating coating material which can be applied to a high-temperature, high-humidity and high-salt environment.

Disclosure of Invention

In view of this, the present application provides a heat insulating coating and a heat insulating structure that are resistant to weather in a high-temperature, high-humidity, high-salt environment, and can be effectively applied to a high-temperature, high-humidity, high-salt environment, and have a good heat insulating property.

Has become commonIt is recognized that under the high temperature, high humidity and high salt environment, unlike the ordinary environment, it has a great influence on the heat insulating property of the coating: the coating using the water-based resin as the adhesive has the advantages of environmental protection, low cost and the like. However, the annual average high-temperature in Hainan is close to 30 ℃, the temperature of the outer wall of a building is usually over 50 ℃, and resin in the coating is softened at a higher temperature. The heat insulation principle of the heat insulation coating is that a good heat insulation effect is formed by utilizing a hole structure in air filling coating with extremely low heat conductivity. Hainan belongs to a high-humidity area, the relative humidity of air can reach more than 90%, so that the high-humidity environment is difficult to avoid in the construction process of the heat-insulating coating, under the high-humidity environment, water vapor in the air easily enters a pore structure in a coating without the protection of a waterproof layer, and is condensed into water drops to exist in the coating when meeting condensation, so that the heat-insulating property of the coating is seriously influenced. Meanwhile, Cl in Hainan air ^- The content of (A) is 0.056-0.225 mg/m ³ At this salt spray concentration, Cl ^- The salt solution penetrates into the interior of the coating to be combined with water drops to form a salt solution, so that the base material is corroded, and the heat insulation performance of the coating is further reduced due to the higher heat conductivity coefficient of the salt solution.

In the related art, in the heat insulating coating under ordinary environment, while pursuing high heat insulating performance, a measure is generally adopted in which the kind or amount of the heat insulating filler is used. Although the contribution of these measures to the insulating properties is direct or significant. Due to the special requirement of the heat insulation effect in the high-temperature, high-humidity and high-salt environment, the obtained heat insulation performance is obviously lower than that in the common environment aiming at some conventional heat insulation fillers adopted by the heat insulation coating in the common environment. That is, the conventional means adopted in the ordinary environment appears to be "malfunctioning" in the high-temperature, high-humidity and high-salt environment.

The present inventors have unexpectedly found that the heat-insulating properties exhibited by the high-temperature, high-humidity and high-salt environment are different from those exhibited by the ordinary environment. The inventor finally discovers that salt (in the form of salt solution) can easily permeate into the coating body under the environment of high temperature, high humidity and high salt, and salt can relatively easily adhere to the surface of the heat-insulating filler and continuously enrich because the inherent hydrophilicity of the heat-insulating filler is obviously higher than that of organic resin, namely the existence of the heat-insulating filler can provide a powerful condition for the heat-insulating filler to adhere to the coating body. The salt is concentrated on the outer surface of the heat insulation filler, and the normal performance of heat insulation mechanisms such as heat conduction or light reflection of the heat insulation particles can be damaged. Specifically, when the salt content is concentrated on the outer surface of the insulating filler, it is apparent that the insulating particles depending on the light reflection insulating mechanism cause the light reflection layer originally included in the insulating particles to be covered, and thus the light reflection mechanism is significantly damaged. For the heat-insulating particles depending on the heat-conduction heat-insulation mechanism, the salt fills the original pores of the heat-insulating particles and the high heat-conduction effect is formed by the enrichment of the salt (namely, the heat-conduction coefficient of the salt is obviously greater than that of air, and the heat-insulating particles depending on the heat-conduction heat-insulation mechanism achieve the heat-insulation purpose by utilizing the air heat conduction), so that the heat conduction is promoted and the heat insulation is reduced.

In order to solve the above problems, the present inventors have surprisingly proposed a heat insulating coating material having excellent heat insulating properties under a high-temperature, high-humidity, high-salt environment. The heat insulation process comprises the following steps: by adding the modified reinforced fiber modified by low-temperature plasma, the hydroxyl content of the fiber surface can be obviously increased compared with that of the unmodified reinforced fiber due to the low-temperature plasma modification, namely the modified reinforced fiber has better hydrophilicity. When salt penetrates into the coating body phase, the modified reinforcing fiber has a more granular "fibrous" characteristic, which makes it easier to contact with salt and to trap salt. More importantly, the modified reinforced fiber has the hydrophilicity obviously higher than that of the heat insulation filler, and is easier to be compatible with salt. The two inherent advantages promote the modified reinforced fibers to preferentially attach salt which may be attached to the heat insulation particles, so that the attachment probability of the salt to the heat insulation particles is reduced, and the heat insulation function of the heat insulation particles is prevented from being damaged by the salt. Based on the above, the invention is created.

In a first aspect, the present application provides a thermal insulation coating resistant to weather in a high-temperature, high-humidity and high-salt environment, comprising the following components:

A. an aqueous organic binder;

B. a thermally insulating filler;

C. modifying the reinforcing fiber;

and, D, a coating adjuvant;

the modified reinforced fiber is obtained by performing low-temperature plasma modification on a reinforced fiber; the dosage of the modified reinforced fiber accounts for 2-6% of the total mass of all the components of the heat insulation coating.

Optionally, the discharge power of the low-temperature plasma modification is 250-300W, the discharge time is 2-10 s, and the discharge pressure is 20-30 Pa.

Optionally, the reinforcing fibers are selected from at least one of aluminum silicate fibers, glass fibers and basalt fibers.

Optionally, the diameter of the aluminum silicate fiber is 10-20 μm, the diameter of the glass fiber is 20-30 μm, and the diameter of the polypropylene fiber is 20-30 μm.

Optionally, the thermal insulation filler is silica aerogel in nanometer scale and hollow glass micro-beads in micrometer scale.

Optionally, the ratio of the mass parts of the silica aerogel to the hollow glass beads is (1-1.5): (0.5 to 1.2).

Optionally, the thermal conductivity of the reinforcing fiber is 0.025-0.046 w/mk.

Optionally, the composition comprises the following components in percentage by mass:

30-40% of water-based organic adhesive, 10-15% of silicon dioxide aerogel, 5-10% of hollow glass beads, 2-6% of modified reinforcing fibers, 30-40% of diluent and 1-2% of coating auxiliary agent, wherein the total mass of all the components is 100%.

Optionally, the hollow glass beads have a mesh number of 60-80 meshes.

The aqueous organic adhesive can be a combination of more than two of aqueous acrylic resin, aqueous polyurethane and vinyl polyester resin, and the compounding ratio of the organic adhesives is that the aqueous acrylic resin: aqueous polyurethane ═ (1-1.5): 1, aqueous acrylic resin: vinyl polyester resin ═ (1 to 1.6): 0.5, waterborne polyurethane: vinyl polyester resin ═ (1 to 1.5): (0.8 to 1.2).

A diluent can be added into the paint auxiliary agent. The diluent is at least one of deionized water and Tianna water; the dispersant is anionic dispersant, specifically at least one of sodium oleate, sulfate ester salt and sulfonate; the thickener is at least one of bentonite, aluminum silicate and hydroxypropyl methyl cellulose; the defoaming agent is at least one of DA-1230 and digao 810, and the preservative is at least one of 5-chloro-2-methyl-4-isothiazoline-3-ketone, 2-benzisothiazolin-3-ketone and hexahydro-1, 3, 5-triethyl-S-triazine.

A method of preparing the thermal barrier coating described above in the present application is easily conceivable. Exemplarily, the preparation method of the weather-proof heat-insulating coating in the high-temperature, high-humidity and high-salt environment comprises the following steps: (1) modifying the silica aerogel and the hollow glass microspheres by using a silane coupling agent, and performing low-temperature plasma modification on the heat-insulating reinforced fibers; (2) adding modified silicon dioxide aerogel, partial diluent, dispersant and defoamer into the aqueous organic binder, and stirring at the rotating speed of 400-500 r/min for 10-30 min to obtain viscous slurry 1; (3) adding the modified hollow glass microspheres into the viscous slurry 1, and stirring at a rotating speed of 100-200 r/min for 60-80 min to obtain viscous slurry 2; (4) and adding the modified heat-insulation reinforcing fiber, part of the diluent and the preservative into the viscous slurry 2, and stirring at the rotating speed of 200-300 r/min for 60-80 min to obtain the weather-resistant heat-insulation coating in the high-temperature, high-humidity and high-salt environment.

In a second aspect, the present application provides a thermal insulation structure of a building body, including a thermal insulation coating layer formed by the thermal insulation coating material as described above.

The formation process for the thermal barrier coating is conventional in any form. For example, the thermal insulation coating is coated on a substrate at one time, the thickness of the thermal insulation coating is 1-2 mm, the thermal insulation coating is cured at the room temperature of 26 ℃ for 2-3 hours, dried for 6-8 hours, cured at the temperature of 80-100 ℃ for 20-40 min, and dried for 2-3 hours.

Drawings

FIG. 1 is an appearance view of the modified fiber composite thermal barrier coating prepared in example 1 after curing and drying.

FIG. 2 is a view of the modified fiber composite thermal barrier coating prepared in example 2 after curing and drying.

FIG. 3 is a view showing the cured and dried appearance of the modified fiber composite thermal barrier coating prepared in example 3.

FIG. 4 is a view showing the cured and dried appearance of the modified fiber composite thermal barrier coating prepared in comparative example 1.

FIG. 5 is a view showing the cured and dried appearance of the modified fiber composite thermal barrier coating prepared in comparative example 2.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example 1

(1) Modifying the silica aerogel and the hollow glass microspheres by using a silane coupling agent, and performing low-temperature plasma modification on the heat-insulating reinforced fiber

(2) Mixing 15-25% of water-based acrylic emulsion, 15-20% of water-based polyurethane emulsion, 13-15% of modified silica aerogel, 16-20% of deionized water, 1-2% of sodium oleate and 1-2% of defoamer DA-1230, and stirring at the rotating speed of 400-500 r/min for 10-30 min to obtain viscous slurry 1

(3) Adding 4-6% of modified hollow glass microspheres into the viscous slurry 1, and stirring at the rotating speed of 100-200 r/min for 60-80 min to obtain viscous slurry 2

(4) Adding 2-4% of modified aluminum silicate fiber, 16-20% of diluent and 0.5-1% of preservative 2-benzisothiazolin-3-one into the viscous slurry 2, and stirring at the rotating speed of 200-300 r/min for 60-80 min to obtain the weather-proof heat-insulating coating under the high-temperature, high-humidity and high-salt environment

(5) Coating the weather-resistant heat-insulating coating prepared in the step (3) on a glass sheet with the thickness of 1-2 mm, curing and drying at 80-100 ℃ for 1-2 hours, placing the cured coating in a high-temperature high-humidity high-salt environment for 25-35 days, observing the appearance change of the coating, and obtaining the implementation result shown in figure 1

Example 2

(2) Mixing 20-25% of water-based acrylic emulsion, 10-20% of vinyl polyester resin, 10-12% of modified silica aerogel, 16-20% of deionized water, 1-2% of sodium sulfonate and 1-2% of defoamer DA-1230, and stirring at the rotating speed of 400-500 r/min for 10-30 min to obtain viscous slurry 1

(3) Adding 3-5% of modified hollow glass microspheres into the viscous slurry 1, and stirring at the rotating speed of 100-200 r/min for 60-80 min to obtain viscous slurry 2

(4) Adding 3-5% of modified aluminum silicate fiber, 16-20% of deionized water and 0.5-1% of preservative 2-benzisothiazolin-3-one into the viscous slurry 2, and stirring at the rotating speed of 200-300 r/min for 60-80 min to obtain the weather-proof heat-insulating coating in the high-temperature, high-humidity and high-salt environment

(5) And (4) coating the weather-resistant heat-insulating coating prepared in the step (3) on a glass sheet with the thickness of 1-2 mm, curing and drying at 80-100 ℃ for 1-2 hours, placing the cured coating in a high-temperature, high-humidity and high-salt environment for 25-35 days, and observing the appearance change of the coating, wherein the weather-resistant heat-insulating coating in the high-temperature, high-humidity and high-salt environment is coated on the glass sheet with the thickness of 1-2 mm, and the implementation result is shown in figure 2.

Example 3

(1) Modifying the silica aerogel and the hollow glass microspheres by using a silane coupling agent, and performing low-temperature plasma modification on the heat insulation reinforced fiber

(2) Mixing 20-25% of waterborne polyurethane, 15-20% of vinyl polyester resin, 10-12% of modified silica aerogel, 16-20% of deionized water, 1-2% of sodium sulfonate and 1-2% of defoamer DA-1230, and stirring at a rotating speed of 400-500 r/min for 10-30 min to obtain viscous slurry 1

(4) Adding 3-5% of modified glass fiber, 16-20% of deionized water and 0.5-1% of preservative 2-benzisothiazolin-3-one into the viscous slurry 2, and stirring at the rotating speed of 200-300 r/min for 60-80 min to obtain the weather-proof heat-insulating coating in the high-temperature, high-humidity and high-salt environment

(5) Coating the weather-resistant heat-insulating coating prepared in the step (3) on a glass sheet with the thickness of 1-2 mm, curing and drying at 80-100 ℃ for 1-2 hours, placing the cured coating in a high-temperature high-humidity high-salt environment for 25-35 days, observing the appearance change of the coating, and obtaining the implementation result shown in figure 3

Comparative example 1

The same as example 1, except that the alumina silicate fiber added in step (4) was not modified, the results were shown in FIG. 4

Comparative example 2

The method is the same as example 1, except that the aluminum silicate fibers added in the step (4) are modified by the following method: adding aluminum silicate fiber into ethanol (10 wt%) mixed ethylene glycol (5 wt%) water solution, adjusting pH to 8-9, ultrasonic dispersing (power is 1000w, ultrasonic time is 30min), drying, and oven drying at 120 deg.C. The results are shown in FIG. 5

< evaluation >

1. Evaluation procedure

After the paint prepared in each example is brushed and cured, a coating test block meeting the test conditions is prepared, and the coating test block is treated for 24 hours in a high-temperature, high-humidity and high-salt environment for performance test.

(1) And (3) testing the heat conductivity coefficient: the coatings were made into thin sheets (50mm 30mm 5mm) and tested using a Hot Disk thermal constant analyzer.

(2) Testing the heat insulation performance: the coating was applied to a 10mm x 10mm iron plate to prepare a sample plate, and the heat insulating effect of the sample plate was tested under the same conditions.

(3) Tensile Strength the coating was formed into a 60mm by 10mm by 3mm sheet and the tensile strength was measured according to the GB/T5281992 "determination of tensile stress strain Properties of vulcanized rubber or thermoplastic rubber".

(4) And (3) hardness testing: the hardness of the coating was measured according to the regulations of GB/T6739-2006 Pencil test method for coating hardness.

(5) And (3) observing the cracking condition of the coating: the prepared weather-resistant heat-insulating coating in the high-temperature high-humidity high-salt environment is coated on a glass sheet with the thickness of 1-2 mm, the glass sheet is cured and dried for 1-2 hours at the temperature of 80-100 ℃, the cured coating is placed in the high-temperature high-humidity high-salt environment for treatment for 25-35 days, and appearance change of the surface of the coating is observed.

2. Evaluation results

The data in the table show that the heat insulation coating prepared by the invention still has stronger heat insulation effect and better mechanical property after being treated in high-temperature, high-humidity and high-salt environment.

Referring to fig. 1 to 5, it can be seen from the results of these figures that whether the thermal insulation reinforcing fibers are modified or not has a significant effect on the crack resistance of the coating material in a high-temperature, high-humidity and high-salt environment, and when the modified thermal insulation reinforcing fibers are added to the coating material system, the coating layers of the three examples are not cracked, and when the unmodified thermal insulation reinforcing fibers are added to the coating material system, the coating layers are cracked.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.

Claims

1. The heat insulation coating with weather resistance in a high-temperature, high-humidity and high-salt environment is characterized by comprising the following components:

A. an aqueous organic binder;

B. a thermally insulating filler;

C. modifying the reinforcing fiber;

and, D, a coating adjuvant;

2. The thermal insulation coating of claim 1, wherein the low-temperature plasma modification has a discharge power of 250-300W, a discharge time of 2-10 s, and a discharge pressure of 20-30 Pa.

3. The thermal insulating coating according to claim 1, wherein the reinforcing fibers are at least one selected from the group consisting of aluminum silicate fibers, glass fibers, and basalt fibers.

4. The heat-insulating coating as claimed in claim 3, wherein the aluminum silicate fibers have a diameter of 10 to 20 μm, the glass fibers have a diameter of 20 to 30 μm, and the polypropylene fibers have a diameter of 20 to 30 μm.

5. The thermal insulation coating of claim 1, wherein the thermal insulation filler is silica aerogel in nanometer scale and hollow glass micro beads in micrometer scale.

6. The thermal insulation coating as claimed in claim 5, wherein the ratio of the mass parts of the silica aerogel to the hollow glass beads is (1-1.5): (0.5 to 1.2).

7. The thermal insulating coating according to claim 1, wherein the thermal conductivity of the reinforcing fibers is 0.025-0.046 w/mk.

8. The heat-insulating coating according to claim 5, comprising the following components in percentage by mass:

9. The heat-insulating coating according to claim 5, wherein the hollow glass beads have a mesh size of 60 to 80 meshes.

10. A heat insulating structure of a building body, characterized by comprising a heat insulating coating formed of the heat insulating coating according to any one of claims 1 to 9.