Novel anti-ultraviolet heat-insulating transparent composite coating and preparation method thereof

Abstract

The invention discloses a novel anti-ultraviolet heat-insulating transparent composite coating and a preparation method thereof. The novel anti-ultraviolet heat-insulating transparent composite coating is prepared from macromolecular resin, phenylbenzimidazole sulfonic acid, an infrared absorbent, chitosan, polytetrafluoroethylene, a flatting agent, a defoaming agent, a coalescing agent, a thickening agent and a diluent. The preparation method comprises the following steps: dissolving chitosan powder in a dilute acid solution at 40-60 DEG C, uniformly stirring until the chitosan powder is completely dissolved, adding an infrared absorbent, uniformly stirring, and drying the dilute acid solution to obtain a chitosan-coated infrared absorbent material; and mixing the infrared absorbent material, phenylbenzimidazole sulfonic acid, polymer resin, polytetrafluoroethylene, a flatting agent, a defoaming agent, a coalescing agent and a thickening agent to obtain the composite coating. The heat-insulating composite coating disclosed by the invention not only has an excellent heat-insulating function, but also has an anti-ultraviolet function, and can achieve double effects of heat insulation and ultraviolet prevention when being applied to external coating of automobiles and buildings; in addition, a coating layer formed by the transparent heat-insulating composite coating is high in hardness, strong in adhesive force and excellent in aging resistance.

Description

Technical Field

[0001] The invention belongs to the field of coatings, and in particular relates to a novel transparent UV-proof heat-insulating transparent composite coating and a preparation method thereof. Background Art

[0002] Transparent thermal insulation coatings can be applied to glass, resin, metal, and cement surfaces to enhance thermal insulation in cars and homes. However, most thermal insulation films currently on the market can only be applied internally due to ageing issues and are unable to achieve the high thermal insulation and heat dissipation effects of external applications. The solar spectrum can be divided into three wavelength bands: ultraviolet, visible light, and infrared. Infrared light has the highest radiation energy, so blocking infrared light while ensuring visible light transmittance is a fundamental requirement for thermal insulation glass.

[0003] Existing infrared absorbers can be ITO, FTO, WO3, Cs x WO3 or ATO has good visible light transmittance and infrared blocking properties. It can be added as functional powder to water-based PU (polyurethane) to prepare transparent thermal insulation coatings. x WO3 or ATO metal nanomaterials have poor dispersibility and their thermal insulation properties are difficult to fully exert.

[0004] Based on this, a new type of heat-insulating transparent composite coating is studied to improve the dispersion of infrared absorbers with heat-insulating function and achieve high heat insulation and high heat dissipation for external application. Summary of the Invention

[0005] Purpose of the invention: The technical problem to be solved by the present invention is to provide a new type of thermal insulation transparent composite coating system, which can not only improve the dispersibility of nano-indium tin oxide, but also achieve UV protection when applied to automotive films and building exterior coatings.

[0006] Technical solution: The novel UV-proof heat-insulating transparent composite coating of the present invention comprises the following raw materials in parts by weight: 30-40 parts of polymer resin, 12-18 parts of phenylbenzimidazole sulfonic acid, 10-15 parts of infrared absorber, 3-5 parts of chitosan, 0.1-0.3 parts of polytetrafluoroethylene, 0.1-0.3 parts of leveling agent, 0.1-0.3 parts of defoaming agent, 0.1-0.3 parts of film-forming aid, 0.1-0.3 parts of thickener and 31.5-33.7 parts of diluent water.

[0007] The invention is based on a system consisting of a polymer resin, an infrared absorber, a leveling agent, a defoaming agent, a film-forming aid and a thickener. Phenylbenzimidazole sulfonic acid and chitosan are introduced, and the infrared absorber is wrapped by chitosan, thereby improving the dispersibility of the infrared absorber in the overall waterborne polyurethane system. In addition, electrostatic interaction exists between the sulfonic acid group of the phenylbenzimidazole sulfonic acid and the protonated amino group of the chitosan, and hydrogen bonds are formed between the hydroxyl groups of the phenylbenzimidazole sulfonic acid and the hydroxyl groups of the chitosan, thereby promoting the mixing and dispersion of the two in the system, improving the dispersion stability of the overall system, and further improving the heat insulation and UV protection properties of the coating.

[0008] At the same time, polytetrafluoroethylene is introduced into the composite coating system. This substance can migrate to the surface due to its low surface energy during the drying and film-forming process, thereby increasing the surface hydrophobicity of the coating material and its aging resistance.

[0009] Furthermore, the polymer resin used in the composite coating of the present invention can be a waterborne polyurethane resin, a waterborne acrylic resin or a polysiloxane resin.

[0010] Furthermore, the leveling agent used in the composite coating of the present invention may include a silicone leveling agent or an acrylate leveling agent, and more preferably, Silway 450, Tech-2754, JS-3018, DH-3187, GS-1665, or Tech-180W.

[0011] Furthermore, the defoamer used in the composite coating of the present invention is a silicone defoamer, a polyether defoamer, or a mineral oil defoamer, and more preferably BYK-088, TEGO Foamex 810, or TEGO Foamex 808.

[0012] Furthermore, the film-forming aid used in the composite coating of the present invention includes benzyl alcohol, dodecyl alcohol ester or 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate.

[0013] Furthermore, the thickener used in the composite coating of the present invention includes sodium polyacrylate, hydroxymethyl cellulose, hydroxyethyl cellulose and carboxymethyl cellulose.

[0014] The method for preparing the novel UV-proof heat-insulating composite coating of the present invention comprises the following steps:

[0015] (1) dissolving chitosan powder in a dilute acid solution at 40-60° C., stirring uniformly until completely dissolved, adding an infrared absorber, stirring uniformly, and drying the dilute acid solution to obtain a chitosan-coated infrared absorber material;

[0016] (2) The composite coating is prepared by mixing an infrared absorber material, phenylbenzimidazole sulfonic acid, polytetrafluoroethylene, a polymer resin, a leveling agent, a defoaming agent, a film-forming aid and a thickener.

[0017] Beneficial effects: Compared with the existing technology, the significant advantages of the present invention are: the thermal insulation composite coating not only has excellent thermal insulation function, but also has UV protection function. When used for automobile and building exterior coating, it can achieve the dual effects of thermal insulation and UV protection; in addition, the coating formed by the thermal insulation composite coating has high hardness, strong adhesion and excellent aging resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a picture showing the effect of the coating prepared in Example 1 of the present invention being applied on ordinary glass;

[0019] Figure 2 Schematic diagram of UV protection testing of the coating prepared in Example 1 of the present invention applied on ordinary glass. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is further described in detail below with reference to the embodiments.

[0021] It should be noted that the raw materials used in the present invention can be purchased from the market. In addition, the dilute acid solution used in the preparation of the composite coating described below is a hydrochloric acid solution with a mass fraction of about 3.6%.

[0022] Example 1

[0023] The components and contents of the thermal insulation composite coating of Example 1 are shown in Table 1 below.

[0024] Table 1 Component contents of thermal insulation composite coatings of Example 1

[0025] Serial number raw material Content / portion 1 Waterborne polyurethane resin 35 2 Phenylbenzimidazole sulfonic acid 15 3 Nano-indium tin oxide 12 4 Chitosan 4 5 polytetrafluoroethylene 0.2 6 Leveling agent Silway450 0.2 7 Defoamer BYK-088 0.2 8 Benzyl alcohol 0.3 9 Sodium polyacrylate 0.3 10 water 32.8

[0026] The thermal insulation composite coating of Example 1 is prepared by the following steps:

[0027] (1) dissolving chitosan powder in a dilute acid solution at 50° C., stirring uniformly until completely dissolved, adding nano-indium tin oxide, stirring uniformly, and then steaming and drying the dilute acid solution to obtain a chitosan-coated infrared absorber material;

[0028] (2) Adding waterborne polyurethane resin, phenylbenzimidazole sulfonic acid, polytetrafluoroethylene, leveling agent Silway 450, defoaming agent BYK-088, benzyl alcohol and sodium polyacrylate to the mixture, mixing to obtain the composite coating.

[0029] Example 2

[0030] The component contents of the thermal insulation composite coating of Example 2 are shown in Table 2 below.

[0031] Table 2 Component contents of thermal insulation composite coatings of Example 2

[0032] Serial number raw material Content / portion 1 Waterborne polyurethane resin 40 2 Phenylbenzimidazole sulfonic acid 12 3 Nano-indium tin oxide 10 4 Chitosan 3 5 polytetrafluoroethylene 0.3 6 Leveling agent Silway450 0.3 7 Defoamer BYK-088 0.3 8 Benzyl alcohol 0.2 9 Sodium polyacrylate 0.2 10 water 33.7

[0033] The thermal insulation composite coating of Example 2 is prepared by the following steps:

[0034] (1) dissolving chitosan powder in a dilute acid solution at 50° C., stirring uniformly until completely dissolved, adding nano-indium tin oxide, stirring uniformly, and drying the dilute acid solution to obtain a chitosan-coated infrared absorber material;

[0035] (2) adding waterborne polyurethane resin, phenylbenzimidazole sulfonic acid, polytetrafluoroethylene, leveling agent Silway 450, defoaming agent BYK-088, benzyl alcohol and sodium polyacrylate to the mixture and aging the mixture to obtain the composite coating.

[0036] Example 3

[0037] The component contents of the thermal insulation composite coating of Example 3 are shown in Table 3 below.

[0038] Table 3 Component contents of thermal insulation composite coatings of Example 3

[0039]

[0040]

[0041] The thermal insulation composite coating of Example 3 is prepared by the following steps:

[0042] (1) dissolving chitosan powder in a dilute acid solution at 50° C., stirring uniformly until completely dissolved, adding nano-indium tin oxide, stirring uniformly, and drying the dilute acid solution to obtain a chitosan-coated infrared absorber material;

[0043] (2) Adding waterborne polyurethane resin, phenylbenzimidazole sulfonic acid, polytetrafluoroethylene, leveling agent Silway 450, defoaming agent BYK-088, benzyl alcohol and sodium polyacrylate to the mixture, mixing to obtain the composite coating.

[0044] Performance testing-mechanical properties

[0045] The heat-insulating composite coating is applied on ordinary glass, such as Figure 1 As shown, the mechanical properties were tested and the results were shown in Table 4 below.

[0046] Table 4 Mechanical properties of the coating prepared in Example 1

[0047]

[0048] From Table 4, it can be seen that the mechanical properties of the coatings prepared in the present invention can meet the corresponding national standards.

[0049] Performance testing-thermal insulation performance

[0050] The coating of the present invention was applied to a square sealed ordinary glass box (3 mm thick), and a temperature sensor was placed inside the square sealed glass box. The glass box was placed in a box and irradiated with a 250 W infrared lamp. A temperature sensor was also placed inside the box to detect the temperature inside and outside the glass box. After 2 hours, the results are shown in Table 5 below.

[0051] Table 5 Temperature difference table of thermal insulation composite coating

[0052] Example Temperature inside the box Temperature inside the glass box ΔT Example 1 65℃ 52℃ 13℃ Example 2 65℃ 58℃ 7℃ Example 3 65℃ 50℃ 15℃

[0053] As can be seen from Table 5, the thermal insulation composite coating of the present invention can make the temperature difference between the inside and outside of the coating reach more than 5°C, or even reach a difference of 15°C, thereby effectively improving the thermal insulation performance.

[0054] Performance test 3-UV protection performance test

[0055] Use an anti-UV tester to test the UV transmittance under light transmission conditions, such as Figure 2 The results obtained are shown in Table 6 below.

[0056] Table 6 Anti-ultraviolet performance of Examples 1-3

[0057] Example Average UV absorption rate at 290-320nm Example 1 99.8％ Example 2 99.4％ Example 3 99.9％

[0058] From Table 6, it can be seen that the thermal insulation composite coating prepared by the present invention can effectively absorb ultraviolet rays, thereby achieving effective ultraviolet protection effect.

[0059] Comparative Example 1

[0060] The basic steps are the same as those in Example 1, except that chitosan is not added.

[0061] The coating prepared in Comparative Example 1 was tested for heat insulation and UV protection, and the results obtained are shown in Table 7.

[0062] Table 7 Heat insulation and UV protection properties of Example 1 and Comparative Example 1

[0063]

[0064]

[0065] From Table 7, it can be seen that although raw materials with heat insulation and UV protection functions are used, without the help of chitosan and phenylbenzimidazole sulfonic acid to improve the dispersibility of nano-indium tin oxide, the agglomeration of nano-indium tin oxide in the system cannot be avoided, which ultimately affects its heat insulation and mechanical properties.

[0066] In addition to the above examples, it should be noted that the specific raw materials and preparation processes defined in the present invention can achieve the technical effects claimed in the present invention. For example, the infrared absorber can also be FTO, WO3, Cs x WO3 or ATO. Leveling agents can include silicone or acrylate leveling agents, specifically Tech-2754, JS-3018, DH-3187, GS-1665, or Tech-180W. Defoamers can be silicone, polyether, or mineral oil defoamers, specifically TEGO Foamex 810 or TEGO Foamex 808. Coagulants can also include lauryl alcohol esters or 2,2,4-trimethylpentanediol monoisobutyrate. Thickeners can also include hydroxymethyl cellulose, hydroxyethyl cellulose, and carboxymethyl cellulose.

Claims

1. A new type of UV-proof heat-insulating transparent composite coating, characterized in that: The raw materials include the following in parts by weight: 30-40 parts of polymer resin, 12-18 parts of phenylbenzimidazole sulfonic acid, 10-15 parts of infrared absorber, 3-5 parts of chitosan, 0.1-0.3 parts of polytetrafluoroethylene, 0.1-0.3 parts of leveling agent, 0.1-0.3 parts of defoaming agent, 0.1-0.3 parts of film-forming aid, 0.1-0.3 parts of thickener and 31.5-33.7 parts of diluent water.

2. The novel UV-proof heat-insulating transparent composite coating according to claim 1, characterized in that: The infrared absorber is ITO, FTO, WO3, Cs x WO3 or ATO.

3. The novel UV-proof heat-insulating transparent composite coating according to claim 1, characterized in that: The polymer resin is water-based polyurethane resin, water-based acrylic resin or polysiloxane resin.

4. The novel UV-proof heat-insulating transparent composite coating according to claim 1, characterized in that: The leveling agent includes an organic silicon leveling agent or an acrylate leveling agent.

5. The novel UV-proof heat-insulating transparent composite coating according to claim 4, characterized in that: The leveling agent is Silway 450, Tech-2754, JS-3018, DH-3187, GS-1665 or Tech-180W.

6. The novel UV-proof heat-insulating transparent composite coating according to claim 1, characterized in that: The defoaming agent is an organosilicon defoaming agent, a polyether defoaming agent or a mineral oil defoaming agent.

7. The novel UV-proof heat-insulating transparent composite coating according to claim 6, characterized in that: The defoaming agent is BYK-088, TEGO Foamex 810 or TEGO Foamex 808.

8. The novel UV-proof heat-insulating transparent composite coating according to claim 1, characterized in that: The film-forming aid includes benzyl alcohol, dodecyl alcohol ester or 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate.

9. The novel UV-proof heat-insulating transparent composite coating according to claim 1, characterized in that: The thickeners include sodium polyacrylate, hydroxymethyl cellulose, hydroxyethyl cellulose and carboxymethyl cellulose.

10. A method for preparing the novel UV-proof heat-insulating transparent composite coating according to claim 1, characterized in that: The steps include: (1) dissolving chitosan powder in a dilute acid solution at 40-60° C., stirring uniformly until completely dissolved, adding an infrared absorber, stirring uniformly, and drying the dilute acid solution to obtain a chitosan-coated infrared absorber material; (2) The composite coating is prepared by mixing an infrared absorber material, phenylbenzimidazole sulfonic acid, polytetrafluoroethylene, a polymer resin, a leveling agent, a defoaming agent, a film-forming aid and a thickener.

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