Automobile glass composite heat insulation film and preparation process thereof

Abstract

The application relates to an automobile glass composite heat insulation film and a preparation process thereof, and belongs to the technical field of glass heat insulation films. The composite heat insulation film comprises a PET base material layer and a heat insulation layer; the heat insulation layer is obtained by curing coating of a high polymer base material and nano ceramic material; the formula of the heat insulation layer is as follows: 90-100 parts of water-based polyurethane emulsion, 15-20 parts of nano ceramic material, 5-7 parts of auxiliary film forming agent, 0.3-0.6 parts of wetting agent, 3-5 parts of leveling agent, 0.5-1.5 parts of silane coupling agent and 2-3 parts of defoaming agent; high-efficiency heat insulation is realized, and the adhesion is obviously improved.

Description

Technical Field

[0001] This invention belongs to the field of glass heat insulation film technology, and relates to an automotive glass composite heat insulation film and its preparation process. Background Technology

[0002] Automotive window film is a functional film applied to the surface of automotive glass. Its main functions include blocking solar radiation heat, reducing UV damage, preventing glass shattering, and improving driving comfort. With the development of the automotive industry and consumers' increasing demands for energy conservation, environmental protection, and driving comfort, the market demand for high-performance window film continues to grow.

[0003] Currently, automotive heat insulation films are mainly divided into three types: dyed films, metallic reflective films, and nano-ceramic films. Dyed films absorb heat through organic dyes, but suffer from poor durability, easy fading, and rapid degradation of heat insulation performance. Metallic reflective films (such as aluminum, silver, indium, etc.) achieve heat insulation by reflecting infrared rays, offering good heat insulation effects. However, the metal layer can shield electromagnetic signals, affecting the normal operation of devices such as GPS, ETC, and 5G communication. Furthermore, metals are prone to oxidation and corrosion, resulting in insufficient long-term reliability. Nano-ceramic heat insulation films, on the other hand, utilize the selective absorption / reflection characteristics of infrared rays to achieve highly efficient heat insulation without shielding electromagnetic signals, while also exhibiting excellent weather resistance and chemical stability.

[0004] However, existing nano-ceramic heat insulation films still face the following technical bottlenecks in practical applications: it is difficult to balance transparency and heat insulation performance, the infrared blocking band is incomplete, the nanoparticle dispersion is poor, and the coating adhesion and durability need to be improved.

[0005] Therefore, there is an urgent need to develop a composite heat insulation film for automotive glass with excellent adhesion and heat insulation effect. Summary of the Invention

[0006] The purpose of this invention is to provide an automotive glass composite heat insulation film and its preparation process. Through the hollow structure design of nano-ceramic materials, the control of structural composition, and the multi-component synergy of coating formulation, high transparency is maintained while achieving efficient heat insulation and significantly improving adhesion and durability.

[0007] The objective of this invention can be achieved through the following technical solutions: A composite heat insulation film for automotive glass, the composite heat insulation film comprising a PET substrate layer and a heat insulation layer; The heat insulation layer is obtained by curing a coating composed of a polymer substrate and nano-ceramic materials. The formula of the heat insulation layer is the following raw materials in parts by weight: 90-100 parts of water-based polyurethane emulsion, 15-20 parts of nano-ceramic materials, 5-7 parts of film-forming agent, 0.3-0.6 parts of wetting agent, 3-5 parts of leveling agent, 0.5-1.5 parts of silane coupling agent, and 2-3 parts of defoamer. The nano-ceramic material was prepared by pre-coordination, hydrolysis and heat treatment of 1,2-bis(trimethoxysilyl)ethane and organic precursor.

[0008] As a preferred embodiment of the present invention, the preparation process of the nano-ceramic material is as follows: S1. Add 1,2-bis(trimethoxysilyl ethane) to ethanol to obtain a mixture A with a concentration of 10~30 mg / mL; S2. Under nitrogen protection, add a mixed solution of organotin precursor and organoantimony precursor to mixture A, wherein the molar ratio of Sn to Sb is (90~95):(5~10), and stir at 40~60℃ for 2~4h to obtain mixture B; S3. Add deionized water to mixture B, with a molar ratio of deionized water to 1,2-bistrimethoxysilyl ethane of (1~3):1. Add hydrochloric acid to adjust the pH to 4~5. Stir at 50~70℃ for 1~2h. Continue to add 3-aminopropyltrimethoxysilane and maintain the stirring conditions for 2~4h. Then age at room temperature for 12~24h. After centrifugation, washing, and vacuum drying at 60~80℃ for 8~12h, sieve to control the particle size of the obtained solid powder to be 1~5μm to obtain the precursor powder. S4. The precursor powder is placed in a tube furnace and heat-treated to obtain the nano-ceramic non-metallic material.

[0009] In a preferred embodiment of the present invention, the film-forming agent is alcohol ester-12 and the wetting agent is BASF 4063.

[0010] As a preferred embodiment of the present invention, the leveling agent is one or more of BYK375, Tego410 and Tego450.

[0011] As a preferred embodiment of the present invention, the defoamer is one or more of BYK021, BYK022 and BYK023.

[0012] As a preferred embodiment of the present invention, the molar ratio of 1,2-bis(trimethoxysilyl ethane), organotin precursor and organoantimony precursor is 1:(2~2.5):(0.15~0.2).

[0013] As a preferred embodiment of the present invention, the organotin precursor is one of dibutyltin oxide and tetrabutyltin, and the organoantimony precursor is one of triphenylantimony and antimony acetate.

[0014] As a preferred embodiment of the present invention, the molar ratio of 3-aminopropyltrimethoxysilane to 1,2-bistrimethoxysilylethane is (0.1~0.3):1.

[0015] As a preferred embodiment of the present invention, the heat treatment conditions are as follows: under inert gas protection, the heating rate is 2~5℃ / min, the heat treatment temperature is 600~900℃, and the holding time is 2~4h.

[0016] A manufacturing process for an automotive glass composite heat insulation film is described below: By weight, 90-100 parts of waterborne polyurethane emulsion, 15-20 parts of nano-ceramic material, 5-7 parts of film-forming agent, 0.3-0.6 parts of wetting agent, 3-5 parts of leveling agent, 0.5-1.5 parts of silane coupling agent, and 2-3 parts of defoamer are mixed and stirred at 200-250 r / min for 30 min to obtain the heat insulation layer coating. The heat insulation layer coating is then applied to the PET substrate layer to a thickness of 5 μm and dried at 60-80℃ for 30-50 min to obtain the automotive glass composite heat insulation film.

[0017] This invention incorporates a heat-insulating layer onto a PET substrate and adds nano-ceramic materials to the polymer resin matrix to improve the heat insulation effect. Specifically, 1,2-bis(trimethoxysilyl)ethane serves as both a silicon source and a pore-forming agent, eliminating the need for additional template agents and simplifying the process.

[0018] The precursor is mixed with 1,2-bis(trimethoxysilyl)ethane. While the silane is still partially or completely hydrolyzed, it first forms coordination / covalent bonds with the metal precursor, followed by controlled hydrolysis and condensation to form a uniformly dispersed organic-inorganic hybrid precursor. Initially, the methoxy groups of the silane exchange with the alkoxy or carboxylic acid groups of the precursor, achieving molecular-level mixing. The amount of water added is controlled to slow the hydrolysis and condensation reaction, avoiding violent aggregation. At this point, because the metal is pre-bonded to the silane, the Si-O-Si network formed by hydrolysis... Sn and Sb atoms are uniformly distributed in the network; then a second organosiloxane, 3-aminopropyltrimethoxysilane, is added. The amino group of 3-aminopropyltrimethoxysilane reacts with the residual silanol or metal hydroxyl groups in the system to form a secondary cross-linked network. This controls the degree of hydrolysis, avoids violent agglomeration, and obtains precursor particles with uniform particle size, further improving the network structure and increasing the network flexibility, which is beneficial for maintaining the hollow structure. The introduction of amino groups improves the hydrophilicity of the precursor, making it easier to disperse in subsequent aqueous systems and helping to regulate the pore structure.

[0019] During the heat treatment process, no template removal step is required. The organic groups are pyrolyzed and volatilized. Due to the gas escape and volume shrinkage generated by the pyrolysis of the organic groups, a hollow or porous structure is formed inside the particles. The Si-O-Si network is retained and densified. Sn and Sb are transformed in situ into SnO2 and Sb-doped ATO crystal phases, forming nano-ceramic materials.

[0020] Therefore, in the obtained nano-ceramic material, Sn / Sb doping forms an ATO crystal phase, providing infrared blocking function, while the SiO2 matrix plays a supporting and refractive index regulating role. The hollow structure of the material further reduces the effective refractive index, and the hollow structure increases the multiple reflection and absorption paths of infrared light inside the particles. Therefore, it can be used as a highly transparent and highly heat-insulating nanofiller for automotive glass composite heat insulation films.

[0021] The beneficial effects of this invention are: This invention utilizes hollow-structured nano-ceramic materials as the thermal insulation functional body. Its unique hollow structure reduces the effective refractive index of the material to near that of a polyurethane resin matrix, significantly reducing light scattering at the inorganic / organic particle interface. Simultaneously, the synergistic effect of wetting agents and leveling agents in the coating formulation ensures uniform spreading of the coating on the PET substrate, avoiding additional light scattering caused by uneven coating. Furthermore, the ATO crystals in the nano-ceramic material exhibit strong absorption in the mid- and far-infrared bands, while the hollow structure of the material increases the multiple reflection paths of infrared light within the particles, further extending the interaction time between light and the material, achieving excellent infrared blocking. Using an aqueous polyurethane emulsion as the film-forming substance and water as the dispersion medium, combined with a low-VOC film-forming aid, the thermal insulation coating adheres firmly to the PET substrate through the bridging effect of a coupling agent, achieving highly efficient thermal insulation and significantly improving adhesion. Detailed Implementation

[0022] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with embodiments, is provided below.

[0023] It should be noted that, unless otherwise specified, the present invention does not specifically limit the source of the raw materials used in the following embodiments. Commercially available products or products prepared by conventional preparation methods that are well known to those skilled in the art can be used. Experimental methods that do not specify specific conditions are all conventional methods and conventional conditions well known in the art. Example 1

[0024] Preparation of nano-ceramic materials: S1. Add 1,2-bis(trimethoxysilyl ethane) to ethanol to obtain a mixture A with a concentration of 10~30 mg / mL; S2. Under nitrogen protection, a mixed solution of dibutyltin oxide and triphenylantimony was added to mixture A, wherein the molar ratio of Sn to Sb was 95:5. The mixture was stirred at 50°C for 3 hours to obtain mixture B, wherein the molar ratio of 1,2-bistrimethoxysilylethane, organotin precursor and organoantimony precursor was 1:2.2:0.18. S3. Add deionized water to mixture B, with a molar ratio of deionized water to silane of 2:1. Add hydrochloric acid to adjust the pH to 4-5. Stir at 60℃ for 1.5h. Continue to add 3-aminopropyltrimethoxysilane and maintain the stirring conditions for 3h. Then age at room temperature for 18h. After centrifugation, washing, and vacuum drying at 70℃ for 10h, sieve to control the particle size of the obtained solid powder to be 1-5μm to obtain the precursor powder. The molar ratio of 3-aminopropyltrimethoxysilane to 1,2-bistrimethoxysilylethane is 0.2:1. S4. The precursor powder is placed in a tube furnace and heat-treated to obtain the nano-ceramic non-metallic material. The heat treatment conditions are: under inert gas protection, the heating rate is 3℃ / min, the heat treatment temperature is 750℃, and the holding time is 3h.

[0025] Preparation of composite heat insulation film: By weight, 95 parts of waterborne polyurethane emulsion, 18 parts of nano-ceramic material, 6 parts of alcohol ester-12, 0.5 parts of BASF 4063, 4 parts of BYK375, 1 part of KH-560, and 2.5 parts of BYK-023 are mixed and stirred at 230 r / min for 30 min to obtain the heat insulation layer coating. The heat insulation layer coating is then applied to the PET substrate layer to a thickness of 5 μm and dried at 70°C for 40 min to obtain the automotive glass composite heat insulation film. Example 2

[0026] Preparation of nano-ceramic materials: S1. Add 1,2-bis(trimethoxysilyl ethane) to ethanol to obtain a mixture A with a concentration of 10~30 mg / mL; S2. Under nitrogen protection, a mixed solution of dibutyltin oxide and triphenylantimony was added to mixture A, wherein the molar ratio of Sn to Sb was 90:10. The mixture was stirred at 40~60℃ for 2 hours to obtain mixture B; wherein the molar ratio of 1,2-bistrimethoxysilylethane, organotin precursor and organoantimony precursor was 1:2:0.15. S3. Add deionized water to mixture B, with a molar ratio of deionized water to silane of 1:1. Add hydrochloric acid to adjust the pH to 4-5. Stir at 50°C for 2 hours. Continue to add 3-aminopropyltrimethoxysilane and maintain the stirring conditions for 2 hours. Then age at room temperature for 24 hours. After centrifugation, washing, and vacuum drying at 70°C for 12 hours, sieve to control the particle size of the obtained solid powder to be 1-5 μm to obtain the precursor powder. The molar ratio of 3-aminopropyltrimethoxysilane to 1,2-bistrimethoxysilylethane is 0.1:1. S4. The precursor powder is placed in a tube furnace and heat-treated to obtain the nano-ceramic non-metallic material. The heat treatment conditions are: under inert gas protection, the heating rate is 2℃ / min, the heat treatment temperature is 600℃, and the holding time is 2h.

[0027] Preparation of composite heat insulation film: By weight, 90 parts of waterborne polyurethane emulsion, 15 parts of nano-ceramic material, 5 parts of alcohol ester-12, 0.3 parts of BASF 4063, 3 parts of BYK375, 0.5 parts of KH-560, and 2 parts of BYK-023 are mixed and stirred at 250 r / min for 30 min to obtain the heat insulation layer coating. The heat insulation layer coating is then applied to the PET substrate layer to a thickness of 5 μm and dried at 70°C for 40 min to obtain the automotive glass composite heat insulation film. Example 3

[0028] Preparation of nano-ceramic materials: S1. Add 1,2-bis(trimethoxysilyl ethane) to ethanol to obtain a mixture A with a concentration of 30 mg / mL; S2. Under nitrogen protection, a mixed solution of dibutyltin oxide and triphenylantimony was added to mixture A, wherein the molar ratio of Sn to Sb was 92:8. The mixture was stirred at 60°C for 4 hours to obtain mixture B, wherein the molar ratio of 1,2-bis(trimethoxysilylethane), organotin precursor and organoantimony precursor was 1:2.5:0.2. S3. Add deionized water to mixture B, with a molar ratio of deionized water to silane of 3:1. Add hydrochloric acid to adjust the pH to 4-5, stir at 70℃ for 2 hours, then add 3-aminopropyltrimethoxysilane, maintain the stirring conditions for 4 hours, and then age at room temperature for 24 hours. After centrifugation, washing, and vacuum drying at 80℃ for 12 hours, sieve to control the particle size of the obtained solid powder to be 1-5 μm to obtain the precursor powder; the molar ratio of 3-aminopropyltrimethoxysilane to 1,2-bistrimethoxysilylethane is 0.3:1. S4. The precursor powder is placed in a tube furnace and heat-treated to obtain the nano-ceramic non-metallic material. The heat treatment conditions are: under inert gas protection, the heating rate is 5℃ / min, the heat treatment temperature is 900℃, and the holding time is 4h.

[0029] Preparation of composite heat insulation film: By weight, 100 parts of waterborne polyurethane emulsion, 20 parts of nano-ceramic material, 7 parts of alcohol ester-12, 0.6 parts of BASF 4063, 5 parts of BYK375, 1.5 parts of KH-560, and 3 parts of BYK-023 are mixed and stirred at 250 r / min for 30 min to obtain a heat insulation layer coating. The heat insulation layer coating is then applied to a PET substrate layer with a coating thickness of 5 μm and dried at 80°C for 50 min to obtain the automotive glass composite heat insulation film. Example 4

[0030] It is basically the same as Example 1, except that 3-aminopropyltrimethoxysilane is not added in step S3. Example 5

[0031] It is basically the same as Example 1, except that the amount of nano-ceramic material in the heat insulation coating formula is adjusted to 12 parts. Example 6

[0032] It is basically the same as Example 1, except that the amount of nano-ceramic material in the heat insulation coating formulation is adjusted to 25 parts.

[0033] Comparative Example 1 The method is basically the same as in Example 1, except that the traditional co-precipitation method is used in this comparative example: SnCl4·5H2O and SbCl3 are dissolved in dilute hydrochloric acid at a molar ratio of Sn:Sb=95:5, the pH is adjusted to 8 with ammonia water to generate a precipitate, and after aging, washing and drying, it is calcined at 700℃ for 3 hours and then ground to obtain solid nano-ceramic powder.

[0034] Comparative Example 2 This is basically the same as Example 1, except that step S2 is not performed in this comparative example: S1. Dissolve 1,2-bis(trimethoxysilylethane) in ethanol to prepare a 20 mg / mL solution; S2', Add deionized water (water / 1,2-bis(trimethoxysilylethane) = 2:1), adjust pH to 4.5, and stir at 60°C for 1.5 hours; S3' Add a mixed solution of dibutyltin oxide and triphenylantimony (Sn:Sb=95:5) to the above sol, stir at 60°C for 4 hours, then add APTMS (molar ratio of 0.12:1 to bissilane), continue stirring for 3 hours, and heat treat to obtain nano-ceramic material.

[0035] Comparative Example 3 This comparative example is essentially the same as Example 1, except that only organotin and organoantimony precursors are used, and 1,2-bistrimethoxysilylethane is not added. Dibutyltin oxide and triphenylantimony (Sn:Sb=95:5) were dissolved in ethanol, hydrolyzed with an appropriate amount of water, dried, and then heat-treated at 750℃ for 3 hours. The resulting nano-ceramic material was then ground.

[0036] Comparative Example 4 This is basically the same as Example 1, except that the silane coupling agent KH-560 is not added in this comparative example.

[0037] Performance testing: 1. The heat insulation film materials prepared in Examples 1-6 and Comparative Examples 1-4 were applied to ordinary flat glass, and the light transmittance was tested: the ultraviolet blocking rate, visible light transmittance and infrared blocking rate of the automotive glass films prepared in the Examples and Comparative Examples were tested according to GB 31849-2015 Automotive Window Film Standard. The results are shown in Table 1 below: Table 1 Based on the above data, it can be seen that the heat insulation film prepared by the present invention has excellent heat insulation and adhesion.

[0038] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A composite heat-insulating film for automotive glass, characterized in that, The composite heat insulation film includes a PET substrate layer and a heat insulation layer; The heat insulation layer is obtained by curing a coating composed of a polymer substrate and nano-ceramic materials. The formula of the heat insulation layer is the following raw materials in parts by weight: 90-100 parts of water-based polyurethane emulsion, 15-20 parts of nano-ceramic materials, 5-7 parts of film-forming agent, 0.3-0.6 parts of wetting agent, 3-5 parts of leveling agent, 0.5-1.5 parts of silane coupling agent, and 2-3 parts of defoamer. The nano-ceramic material was prepared by pre-coordination, hydrolysis and heat treatment of 1,2-bis(trimethoxysilyl)ethane and organic precursor.

2. The automotive glass composite heat insulation film according to claim 1, characterized in that, The preparation process of the nano-ceramic material is as follows: S1. Add 1,2-bis(trimethoxysilyl ethane) to ethanol to obtain a mixture A with a concentration of 10~30 mg / mL; S2. Under nitrogen protection, add a mixed solution of organotin precursor and organoantimony precursor to mixture A, wherein the molar ratio of Sn to Sb is (90~95):(5~10), and stir at 40~60℃ for 2~4h to obtain mixture B; S3. Add deionized water to mixture B, with a molar ratio of deionized water to 1,2-bistrimethoxysilyl ethane of (1~3):

1. Add hydrochloric acid to adjust the pH to 4~5. Stir at 50~70℃ for 1~2h. Continue to add 3-aminopropyltrimethoxysilane and maintain the stirring conditions for 2~4h. Then age at room temperature for 12~24h. After centrifugation, washing, and vacuum drying at 60~80℃ for 8~12h, sieve to control the particle size of the obtained solid powder to be 1~5μm to obtain the precursor powder. S4. The precursor powder is placed in a tube furnace and heat-treated to obtain the nano-ceramic non-metallic material.

3. The automotive glass composite heat insulation film according to claim 1, characterized in that, The film-forming agent is alcohol ester-12, and the wetting agent is BASF 4063.

4. The automotive glass composite heat insulation film according to claim 1, characterized in that, The leveling agent is one or more of BYK375, Tego410, and Tego450.

5. The automotive glass composite heat insulation film according to claim 1, characterized in that, The defoamer is one or more of BYK021, BYK022 and BYK023.

6. The automotive glass composite heat insulation film according to claim 2, characterized in that, The molar ratio of the 1,2-bis(trimethoxysilyl ethane), organotin precursor, and organoantimony precursor is 1:(2~2.5):(0.15~0.2).

7. The automotive glass composite heat insulation film according to claim 2, characterized in that, The organotin precursor is one of dibutyltin oxide and tetrabutyltin, and the organoantimony precursor is one of triphenylantimony and antimony acetate.

8. The automotive glass composite heat insulation film according to claim 2, characterized in that, The molar ratio of 3-aminopropyltrimethoxysilane to 1,2-bistrimethoxysilylethane is (0.1~0.3):

1.

9. The automotive glass composite heat insulation film according to claim 2, characterized in that, The heat treatment conditions are as follows: under inert gas protection, the heating rate is 2~5℃ / min, the heat treatment temperature is 600~900℃, and the holding time is 2~4h.

10. A process for preparing an automotive glass composite heat-insulating film as described in any one of claims 1-9, characterized in that, The specific process is as follows: By weight, 90-100 parts of waterborne polyurethane emulsion, 15-20 parts of nano-ceramic material, 5-7 parts of film-forming agent, 0.3-0.6 parts of wetting agent, 3-5 parts of leveling agent, 0.5-1.5 parts of silane coupling agent, and 2-3 parts of defoamer are mixed and stirred at 200-250 r / min for 30 min to obtain the heat insulation layer coating. The heat insulation layer coating is then applied to the PET substrate layer to a thickness of 5 μm and dried at 60-80℃ for 30-50 min to obtain the automotive glass composite heat insulation film.

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