An acrylic resin-based nano thermal insulation coating material, a preparation method and application thereof

Abstract

The application discloses an acrylic resin-based nano thermal insulation coating as well as a preparation method and application thereof. The coating comprises the following components: component A, 100 parts by mass of acrylic resin; 1-20 parts by mass of thermal insulation slurry; 0.125-0.5 parts by mass of ester exchange catalyst; 0-200 parts by mass of solvent; 0.5-5 parts by mass of leveling agent; component B, 1-15 parts by mass of curing agent. An ester compound with an ester functional group is used as a dispersion medium of the nano thermal insulation slurry, the compatibility of the dispersion medium of the thermal insulation slurry and the acrylic resin is improved based on an ester exchange reaction, the dispersibility of the nano thermal insulation filler in the polymer resin is improved, the spectral effect of good near-infrared selective absorption is achieved at a lower filler content, and excellent shielding effect on the near-infrared wave band is achieved.

Description

Technical Field

[0001] This invention relates to the field of multifunctional resin coatings, and in particular to acrylic resin-based nano-thermal insulating coatings, their preparation methods and applications, especially to a method for preparing a thermal insulating coating based on acrylic resin combined with transesterification reaction to improve the compatibility of nano-functional slurry. Background Technology

[0002] In fields such as architectural glass curtain walls, agricultural greenhouses, and automotive glass, internal temperature needs to be regulated. However, traditional methods for balancing temperature and humidity environments mostly rely on high-energy-consuming cooling technologies such as central air conditioning and electric fans. These methods are clearly contrary to the modern society that advocates for "dual-carbon" sustainable development.

[0003] Nearly 50% of solar radiation energy comes from the infrared band. Therefore, blocking near-infrared radiation in an appropriate manner can achieve the purpose of cooling and heat insulation. Adding inorganic heat-insulating fillers to prepare composite materials is a relatively economical and convenient method. Due to their absorption / reflection properties in the near-infrared band, inorganic heat-insulating fillers have excellent near-infrared shielding performance and are widely used in fields with high cooling and heat insulation requirements, such as buildings, agricultural films, and automobiles. Commonly used inorganic heat-insulating fillers include cesium-doped tungsten bronze, ATO, ITO, and lanthanum hexaboride. Chinese patent "CN202311577067 A Waterborne Transparent Heat-Insulating Coating and Its Preparation Method" uses nano-cesium tungsten bronze and nano-alumina as synergistic heat-insulating fillers, compounded with waterborne polyurethane, and with the addition of various functional additives to obtain a waterborne transparent heat-insulating coating. This coating features low VOCs, strong heat insulation performance, significantly improved mechanical properties, and environmental friendliness. Chinese patent "CN202311304966 A composite material with high infrared shielding performance and its preparation method and application" describes the process of ball milling and blending cesium tungsten bronze nanoparticles with acrylate-hydroxypropyl acrylate copolymer, while adding various additives to obtain a composite material with high infrared absorption and transparent visible wavelength.

[0004] Nano-insulating coatings with heat insulation and cooling properties can achieve temperature control and heat insulation without the need for external energy input. However, most inorganic heat insulation fillers have poor compatibility with polymer resins and are prone to agglomeration, which prevents the heat insulation fillers from exhibiting their intrinsic properties. Summary of the Invention

[0005] Purpose of the invention: To solve the problem of poor dispersibility of the above-mentioned nano-insulating inorganic fillers in polymer resins, this invention proposes an acrylic resin-based nano-insulating coating, its preparation method and application. Through transesterification, the small molecule dispersion medium in the insulation slurry is grafted onto the polymer resin backbone. After adding a curing agent, a stable dispersion medium-polymer resin network is formed to avoid the agglomeration of nano-inorganic fillers.

[0006] To address the aforementioned technical problems, this invention discloses an acrylic resin-based nano-thermal insulating coating, comprising the following components in parts by weight:

[0007] Component A: 100 parts acrylic resin; 1-20 parts heat insulation slurry; 0.125-0.5 parts transesterification catalyst; 0-200 parts solvent; 0.5-5 parts leveling agent;

[0008] Component B: 1-15 parts by weight of curing agent;

[0009] Wherein, at least one structural unit of the acrylic resin contains a hydroxyl side group functional group;

[0010] The thermal insulation slurry is composed of nano-thermal insulation fillers and a dispersion medium, wherein the nano-thermal insulation fillers are nano-cesium tungsten bronze (Cs). x WO3), with a particle size of 50-200 nm and a solid content of 20-30%; the dispersion medium is an ester compound with ester functional groups.

[0011] Preferably, the dispersion medium is any one or more of the following ester compounds: triethylene glycol diisooctanoate, triethylene glycol dimethacrylate, ethyl acetate, isobutyl acetate, etc.

[0012] Preferably, the transesterification catalyst is any one or more of dibutyltin oxide (DBTO) and zinc acetate (C4H6O4Zn).

[0013] The solvent is ethanol (C2H5OH) or xylene (C8H5OH). 10 ), toluene (C7H8), sec-butyl acetate (C6H8) 12 O2) and butanone (C4H8O) are any one or more of these.

[0014] The leveling agent is any one or more of Efka FL 3777, Efka FL 3600, BYK-333, BYK-346, BYK-310, and BYK-331.

[0015] The curing agent is a polyurethane curing agent with NCO groups. Specifically, the curing agent is any one or more of toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymethylene polyphenyl polyisocyanate (PAPI), hexamethylene diisocyanate (HDI), and phenylmethylene diisocyanate (XDI).

[0016] This invention further proposes a method for preparing the above-mentioned acrylic resin-based nano-thermal insulating coating, comprising the following steps:

[0017] (1) The acrylic resin is divided into two parts. One part is used to undergo transesterification reaction with the heat insulation slurry, and the other part is used for dilution. Component 1 is 12.5-50 parts by mass, and component 2 is the remaining 87.5-50 parts by mass. Component 1 is mixed with the heat insulation slurry and 0.125-0.5 parts by mass of transesterification catalyst is added. The mixture is heated and stirred to obtain the acrylic heat insulation raw slurry after transesterification reaction.

[0018] (2) Add the heat insulation slurry to the remaining component 2 in step (1), and add leveling agent and solvent according to the mass fraction. Stir mechanically at room temperature until uniformly dispersed to obtain acrylic heat insulation coating.

[0019] (3) When using, add the curing agent to the heat insulation coating obtained in step (2) according to the mass ratio.

[0020] Preferably, in step (1), when the acrylic resin undergoes an ester exchange reaction with the solvent in the heat insulation slurry, the temperature is set to 65-85℃.

[0021] In step (1), the heating and stirring time is 4-8 hours.

[0022] This application further proposes the application of the above-mentioned acrylic resin-based nano-insulating coating in the preparation of heat-insulating and cooling materials.

[0023] Beneficial effects: Compared with existing technologies, this invention uses ester compounds with ester functional groups as the dispersion medium for nano-insulating slurries. By combining transesterification, the ester dispersion medium is grafted onto the side groups of the acrylic resin main chain containing hydroxyl / ester functional groups, improving the compatibility of the dispersion medium with the acrylic resin. This enhances the dispersibility of the nano-insulating filler in the polymer resin, reduces the filler addition amount, and allows the intrinsic spectral characteristics of the nano-filler to be fully utilized. Furthermore, this invention does not use energy-intensive dispersion methods such as ball milling, and the lack of heating during dilution further reduces energy consumption. Attached Figure Description

[0024] Figure 1 The transmission spectra of the heat-insulating coating on the PO membrane in Examples 1-3 are shown.

[0025] Figure 2 The transmission spectra of the heat-insulating coatings on the membranes of Examples 5-7 and Comparative Example 1PO are shown.

[0026] Figure 3 The transmission spectra of the heat-insulating coatings on the glass slides in Examples 3 and 4 are shown.

[0027] Figure 4 The diagram shows the thermal insulation performance of the thermal insulation coatings in Example 3 and Comparative Example 1. Detailed Implementation

[0028] This specific embodiment discloses a method for preparing an acrylic resin-based nano-thermal insulation coating based on transesterification-assisted dispersion, comprising the following components: Component A, 100 parts by weight of acrylic resin; 1-20 parts by weight of thermal insulation slurry; 0.125-0.5 parts by weight of transesterification catalyst; 0-200 parts by weight of solvent; 0.5-5 parts by weight of leveling agent; Component B, 1-15 parts by weight of curing agent. The nano-thermal insulation filler in the thermal insulation slurry is nano-cesium tungsten bronze (Cs). x WO3), the dispersion medium is any one of solvents carrying ester functional groups, such as triethylene glycol diisooctanoate (3GO) and ethyl acetate (EAC). The transesterification catalyst is any one of dibutyltin oxide (DBTO) and zinc acetate (C4H6O4Zn). The solvent is ethanol (C2H5OH) or xylene (C8H5OH). 10 ), toluene (C7H8), sec-butyl acetate (C6H8) 12 The leveling agent is any one of Efka FL 3777, Efka FL 3600, BYK-333, BYK-346, BYK-310, and BYK-331. The curing agent is any one of toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymethylene polyphenyl polyisocyanate (PAPI), hexamethylene diisocyanate (HDI), and phenylenediamine diisocyanate (XDI).

[0029] Examples 1-3 describe heat-insulating coatings with different contents of heat-insulating slurry; Examples 1, 4, and 5 describe heat-insulating coatings with different reaction times; Examples 1, 6, and 7 describe heat-insulating coatings with different amounts of catalyst; Examples 1, 8, and 9 describe heat-insulating coatings with different types of solvents; Examples 1, 10, and 11 describe heat-insulating coatings with different contents of curing agent; Examples 1, 12, and 13 describe heat-insulating coatings with different contents of leveling agent; Examples 1, 14-16 describe heat-insulating coatings with different contents of solvent.

[0030] Example 1:

[0031] (1) 100 parts by weight of acrylic resin (Shandong Aohui Paint Co., Ltd., AH-838-65) were divided into two components: component 1 was 25 parts by weight and component 2 was 75 parts by weight. 25 parts by weight of acrylic resin were mixed with 10 parts by weight of triethylene glycol diisooctanoate heat insulation slurry, and 0.25 parts by weight of dibutyltin oxide were added. The mixture was reacted at 80℃ and 300 rpm for 4 hours to obtain acrylic resin heat insulation slurry.

[0032] (2) Mix the heat insulation slurry with the remaining 75 parts by weight of acrylic resin in step (1), and add 50 parts by weight of ethanol and 2.5 parts by weight of leveling agent (BASF, Efka FL 3777). Stir evenly at 500 rpm at room temperature to obtain acrylic resin-based heat insulation coating.

[0033] (3) Add 10 parts by weight of TDI curing agent (WANNATE TL-75E) to the acrylic resin-based heat insulation coating obtained in step (2), and apply it to the PO film substrate by scraping with a 70μm coating rod, and cure at room temperature to form a heat insulation coating.

[0034] Example 2:

[0035] (1) 100 parts by weight of acrylic resin (Shandong Aohui Paint Co., Ltd., AH-838-65) were divided into two components: component 1 was 12.5 parts by weight and component 2 was 87.5 parts by weight. 12.5 parts by weight of acrylic resin and 5 parts by weight of triethylene glycol diisooctanoate heat insulation slurry were mixed, and 0.125 parts by weight of dibutyltin oxide were added. The mixture was reacted at 80℃ and 300 rpm for 4 hours to obtain acrylic resin heat insulation slurry.

[0036] (2) Mix the heat insulation slurry with the remaining 75 parts by weight of acrylic resin in step (1), and add 50 parts by weight of ethanol and 2.5 parts by weight of leveling agent (BASF, Efka FL 3777). Stir evenly at 500 rpm at room temperature to obtain acrylic resin-based heat insulation coating.

[0037] (3) Add 10 parts by weight of TDI curing agent (WANNATE TL-75E) to the acrylic resin-based heat insulation coating obtained in step (2), and apply it to the PO film substrate by scraping with a 70μm coating rod, and cure at room temperature to form a heat insulation coating.

[0038] Example 3:

[0039] (1) 100 parts by weight of acrylic resin (Shandong Aohui Paint Co., Ltd., AH-838-65) were divided into 37.5 parts by weight and 62.5 parts by weight. 37.5 parts by weight of acrylic resin were mixed with 15 parts by weight of triethylene glycol diisooctanoate heat insulation slurry, and 0.375 parts by weight of dibutyltin oxide were added. The mixture was reacted at 80℃ and 300 rpm for 4 hours to obtain acrylic resin heat insulation slurry.

[0040] (2) Mix the heat insulation slurry with the remaining 62.5 parts by weight of acrylic resin in step (1), and add 30 parts by weight of ethanol and 2.5 parts by weight of leveling agent (BASF, Efka FL 3777). Stir evenly at 500 rpm at room temperature to obtain acrylic resin-based heat insulation coating.

[0041] (3) Add 10 parts by weight of TDI curing agent (WANNATE TL-75E) to the acrylic resin-based heat insulation coating obtained in step (2), and apply it to the PO film substrate by scraping with a 70μm coating rod, and cure at room temperature to form a heat insulation coating.

[0042] Example 4:

[0043] (1) 100 parts by weight of acrylic resin (Shandong Aohui Paint Co., Ltd., AH-838-65) were divided into 50 parts by weight and 50 parts by weight. 50 parts by weight of acrylic resin were mixed with 20 parts by weight of triethylene glycol diisooctanoate heat insulation slurry, and 0.5 parts by weight of dibutyltin oxide were added. The temperature was 80℃, the rotation speed was 300rpm, and the reaction was carried out for 4h to obtain acrylic resin heat insulation slurry.

[0044] (2) Mix the heat insulation slurry with the remaining 50 parts by weight of acrylic resin in step (1), and add 50 parts by weight of ethanol and 2.5 parts by weight of leveling agent (BASF, Efka FL 3777). Stir evenly at 500 rpm at room temperature to obtain acrylic resin-based heat insulation coating.

[0045] (3) Add 10 parts by weight of TDI curing agent (WANNATE TL-75E) to the acrylic resin-based heat insulation coating obtained in step (2), and apply it to the PO film substrate by scraping with a 70μm coating rod, and cure at room temperature to form a heat insulation coating.

[0046] Example 5:

[0047] The heat-insulating coating was prepared according to the steps of Example 1, except that the transesterification reaction time in step (1) was 6 hours.

[0048] Example 6:

[0049] The heat-insulating coating was prepared according to the steps of Example 1, except that the transesterification reaction time in step (1) was 8 hours.

[0050] Example 7:

[0051] The heat-insulating coating was prepared according to the steps of Example 1, except that 0.375 parts by mass of dibutyltin oxide were added in step (1).

[0052] Example 8:

[0053] The heat-insulating coating was prepared according to the steps of Example 1, except that 0.5 parts by mass of dibutyltin oxide were added in step (1).

[0054] Example 9:

[0055] The heat-insulating coating was prepared according to the steps of Example 1, except that: in step (2), sec-butyl acetate was selected as the solvent and 50 parts by mass of sec-butyl acetate were added and stirred.

[0056] Example 10:

[0057] The heat-insulating coating was prepared according to the steps of Example 1, except that in step (2), xylene was selected as the solvent and 50 parts by mass of xylene were added and mixed.

[0058] Example 11:

[0059] The heat-insulating coating was prepared according to the steps of Example 1, except that 5 parts by mass of TDI curing agent (WANNATE TL-75E, Wanhua Chemical Group) were added in step (3).

[0060] Example 12:

[0061] The heat-insulating coating was prepared according to the steps of Example 1, except that 15 parts by weight of TDI curing agent (WANNATE TL-75E) was added in step (3).

[0062] Example 13:

[0063] The heat-insulating coating was prepared according to the steps of Example 1, except that 0.5 parts by weight of leveling agent (BASF, Efka FL 3777) was added in step (2).

[0064] Example 14:

[0065] The heat-insulating coating was prepared according to the steps of Example 1, except that 5 parts by weight of leveling agent (BASF, Efka FL 3777) was added in step (3).

[0066] Example 15:

[0067] The heat-insulating coating was prepared according to the steps of Example 1, except that in step (2), no solvent was added, only a leveling agent (BASF, Efka FL 3777) was added.

[0068] Example 16:

[0069] The heat-insulating coating was prepared according to the steps of Example 1, except that 100 parts by mass of ethanol were added in step (2).

[0070] Example 17:

[0071] The heat-insulating coating was prepared according to the steps of Example 1, except that 200 parts by mass of ethanol were added in step (2).

[0072] Comparative Example 1:

[0073] 15 parts by weight of triethylene glycol diisooctanoate thermal insulation slurry were added to 100 parts by weight of acrylic resin (Shandong Aohui Paint Co., Ltd., AH-838-65), and the mixture was stirred until homogeneous. Then, 30 parts by weight of ethanol and 2.5 parts by weight of leveling agent (BASF, Efka FL 3777) were added to prepare a comparative thermal insulation coating. 10 parts by weight of TDI curing agent (Wanhua Chemical Group, WANNATE TL-75E) were added to the obtained comparative thermal insulation coating, and the coating was applied to a PO film substrate using a 70μm coating rod by scraping. The coating was then cured at room temperature to form a thermal insulation coating.

[0074] In Examples 1-17, the coating was applied immediately after adding the curing agent, with an interval of no more than 2 hours. The PO film substrate was 80 mm long, 30 mm wide, and 150 μm thick. Examples 3 and 4 were also coated onto glass slides using the same method to observe their aggregation. The slide dimensions were 76.2 × 25.4 × 1 mm. The transmittance curves of the coatings were obtained using a UV-Vis spectrophotometer (Cary 5000 spectrophotometer, Agilent, USA) at wavelengths of 200-2500 nm. After the heat-insulating coatings obtained in Examples 1-17 were formed, their heat insulation curves were tested using a WACOM WXL-155SS solar simulator for 2 hours at a light power density of 1000 W / m². 2 .

[0075] Figure 2 The images show the transmittance spectra of the heat-insulating coatings on the films of Examples 5-7 and Comparative Example 1PO. Figure 3 This is a transmission spectrum of the heat-insulating coating on the glass slide. Since the variables adjusted in the embodiments after Example 7 are mainly set to meet different application scenarios and process conditions, their impact on the optical performance of the coating is negligible. Therefore, the results of representative embodiments are given by way of example.

[0076] Combination Figure 1 , 2 It can be seen that the heat insulation coating contains nano-cesium tungsten bronze filler, which reduces the transmission of infrared bands, especially the 880-2500nm band, while ensuring a high transmittance in the visible part. By comparing the spectra of the examples and the comparative examples, it can be found that the heat insulation coating prepared by transesterification can achieve the same or even lower infrared transmittance with less heat insulation slurry added. This shows that the coating of the present invention can effectively reduce the use of heat insulation slurry and obtain better heat insulation effect.

[0077] Depend on Figure 3As can be seen, the coating of this invention has high transmittance in the visible band. In the coating industry, filler agglomeration can affect the optical properties of the coating. Filler agglomeration can lead to unevenness or micro-unevenness on the coating surface, thereby reducing its transparency and gloss. This invention grafts the dispersion medium onto the resin through an ester exchange reaction, preventing further agglomeration of the filler and thus achieving high transparency. The figure shows that the coating has high transparency, proving that ester exchange grafting can effectively prevent the agglomeration of the insulating filler. In practical applications, different insulation requirements can be achieved by adjusting the content of cesium tungsten bronze.

[0078] Figure 4 The thermal insulation performance test of the thermal insulation coating shows that the acrylic resin-based thermal insulation coating of the present invention can effectively reduce the temperature by 7.5℃; the use of ester exchange reaction improves the dispersibility of the thermal insulation filler, and compared with the control group without ester exchange, there is still a temperature reduction of 1-2℃.

[0079] This invention provides a concept and method for developing an acrylic resin-based nano-thermal insulating coating. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technologies.

Claims

1. An acrylic resin-based nano-thermal insulating coating, characterized in that, It contains the following components in parts by weight: Component A: 100 parts acrylic resin; 1-20 parts heat insulation slurry; 0.125-0.5 parts transesterification catalyst; 0-200 parts solvent; 0.5-5 parts leveling agent, wherein the amount of solvent is not 0; Component B: 1-15 parts by weight of curing agent; Wherein, at least one structural unit of the acrylic resin contains a hydroxyl side group functional group; The thermal insulation slurry is composed of nano-thermal insulation fillers and a dispersion medium, wherein the nano-thermal insulation fillers are nano-cesium tungsten bronze (Cs). x WO3), with a particle size of 50-200 nm and a solid content of 20-30%; the dispersion medium is an ester compound with an ester functional group, wherein the ester compound with the ester functional group is any one or more of triethylene glycol diisooctanoate, triethylene glycol dimethacrylate, ethyl acetate, and isobutyl acetate; The preparation method of the acrylic resin-based nano-thermal insulating coating includes the following steps: (1) Divide the acrylic resin into two parts, with component 1 being 12.5-50 parts by weight and component 2 being the remaining 87.5-50 parts by weight. Mix component 1 with the heat insulation slurry and add 0.125-0.5 parts by weight of the transesterification catalyst. Heat and stir to obtain the acrylic heat insulation slurry after the transesterification reaction. (2) Add the acrylic heat insulation paste to the remaining component 2 in step (1), and add leveling agent and solvent according to the mass parts. Stir mechanically at room temperature until uniformly dispersed to obtain acrylic heat insulation coating. (3) When using, add the curing agent to the heat insulation coating obtained in step (2) according to the mass ratio.

2. The acrylic resin-based nano-thermal insulating coating according to claim 1, characterized in that, The transesterification catalyst is any one or more of dibutyltin oxide (DBTO) and zinc acetate (C4H6O4Zn).

3. The acrylic resin-based nano-thermal insulating coating according to claim 1, characterized in that, The solvent is ethanol (C2H5OH) or xylene (C8H5OH). 10 ), toluene (C7H8), sec-butyl acetate (C6H8) 12 O2) and butanone (C4H8O) are any one or more of these.

4. The acrylic resin-based nano-thermal insulating coating according to claim 1, characterized in that, The leveling agent is any one or more of EfkaFL 3777, Efka FL 3600, BYK-333, BYK-346, BYK-310, and BYK-331.

5. The acrylic resin-based nano-thermal insulating coating according to claim 1, characterized in that, The curing agent is any one or more of toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymethylene polyphenyl polyisocyanate (PAPI), hexamethylene diisocyanate (HDI), and phenyl diisocyanate (XDI).

6. The method for preparing the acrylic resin-based nano-thermal insulating coating according to any one of claims 1-5, characterized in that, Includes the following steps: (1) Divide the acrylic resin into two parts, with component 1 being 12.5-50 parts by weight and component 2 being the remaining 87.5-50 parts by weight. Mix component 1 with the heat insulation slurry and add 0.125-0.5 parts by weight of the transesterification catalyst. Heat and stir to obtain the acrylic heat insulation slurry after the transesterification reaction. (2) Add the acrylic heat insulation paste to the remaining component 2 in step (1), and add leveling agent and solvent according to the mass parts. Stir mechanically at room temperature until uniformly dispersed to obtain acrylic heat insulation coating. (3) When using, add the curing agent to the heat insulation coating obtained in step (2) according to the mass ratio.

7. The preparation method according to claim 6, characterized in that, In step (1), the heating and stirring temperature is set to 65-85℃.

8. The preparation method according to claim 6, characterized in that, In step (1), the heating and stirring time is 4-8 hours.

9. The application of the acrylic resin-based nano-insulating coating according to any one of claims 1-5 in the preparation of heat-insulating and cooling materials.

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