Nano-microcapsule-based heat-insulation masterbatch and preparation method therefor

Abstract

The present application discloses a nano-microcapsule-based heat-insulation masterbatch and a preparation method therefor. The nano-microcapsule-based heat-insulation masterbatch is prepared by mixing organic and inorganic composite nano-microcapsules with a polymer matrix material and adding an auxiliary agent for granulation, wherein the addition percentage of the nano-microcapsules is 1-20 wt%, the addition percentage of the auxiliary agent is 0.2-0.5 wt%, and the balance is the polymer matrix material; and the nano-microcapsules are prepared by means of emulsification pre-polymerization, polymerization, and nano-compositing. Compared with conventional heat-insulation masterbatches, the masterbatch has outstanding stability, and higher heat-insulation properties and heat preservation performance.

Description

A nano-microcapsule heat-insulating functional masterbatch and its preparation method

[0001] This application claims priority to the Chinese patent application filed with the Patent Office of China on January 10, 2024, with application number CN202410033638.9 and invention name “A Nano-microcapsule Thermal Insulation Functional Masterbatch and Its Preparation Method”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application relates to the field of nanomaterial technology, and specifically to a nano-microcapsule heat-insulating functional masterbatch and a preparation method thereof. Background Art

[0003] Thermal insulation masterbatches can be used to prepare plastic materials such as thermal insulation films and sheets, playing a vital role in a variety of fields, including construction and automotive. Conventional thermal insulation masterbatches only provide a simple thermal insulation function, leaving much room for improvement in thermal insulation performance, energy storage, and thermal insulation properties.

[0004] Chinese patent CN114752142B discloses a transparent thermal insulation masterbatch based on a cesium tungsten system. This masterbatch is constructed by modifying nano-tungsten cesium oxide to form polymer segments containing ester bonds, and then undergoing an ester exchange reaction to produce a HALS-g-EVA / PVB-g-Cs0.33WO3 composite material, achieving thermal insulation and blue light protection. This modified and composited material, based on a conventional inorganic thermal insulation masterbatch, improves aging resistance and blue light protection, but does not improve thermal insulation. Chinese patent CN108530843B discloses a thermal insulation masterbatch for BOPET window film. The thermal insulation material is a core-inner-shell-outer shell structure composed of nano-carbonized cellulose, titanium dioxide, and polyacrylamide. The thermal insulation function is achieved through the heat absorption of the core and the reflectivity of the inner shell. Its application is primarily in BOPET window film, and no further improvements have been made to its thermal insulation and other functionalities.

[0005] Summary of the Invention

[0006] In view of the above-mentioned deficiencies in the prior art, according to the embodiments of the present application, it is hoped to provide a functional masterbatch with high-efficiency, long-term thermal insulation, energy storage and heat preservation, so as to achieve the improvement of its functionality and the expansion of its application.

[0007] According to an embodiment, the present application provides a nano-microcapsule heat-insulating functional masterbatch, which is made by mixing a plastic substrate and nano-microcapsules, adding additives and granulating. The amount of nano-microcapsules added is 1-20wt% of the masterbatch, and the amount of additives added is 0.2-0.5wt% of the masterbatch, wherein: the plastic substrate is selected from polyethylene, polypropylene, polyvinyl chloride, polymethyl methacrylate, polyethylene terephthalate, polystyrene, and polycarbonate; the nano-microcapsules are nano-thermal insulation materials formed by an organic composite of nano-tungsten doped oxide and alkyd composite crystals; the additive is a complex of ethylene glycol polyoxyethylene ether, γ-aminopropyltriethoxysilane, and tetrakis-(dibutylhydroxyhydrocinnamic acid) pentaerythritol ester.

[0008] According to one embodiment, the preparation method of nanocapsules is as follows:

[0009] (1) According to the mass ratio, 0.5-1 parts of sodium lauryl sulfate are dissolved in 50-80 parts of deionized water to obtain solution A; 5-8 parts of methyl methacrylate, 1-2 parts of ethyl acrylate, 8-15 parts of alkyd composite crystals and 0.1-0.2 parts of azobisisobutyronitrile are ultrasonically mixed for 5-10 minutes to obtain solution B; solution B is added dropwise to solution A and stirred at 20-40°C for 5-30 minutes to obtain emulsion C; emulsion C is stirred and reacted at 75-85°C for 0.5-1.5 hours;

[0010] (2) Dissolve 1-2 parts of sodium lauryl sulfate and 1-5 parts of hydroxyethyl methacrylate in 120-150 parts of deionized water to obtain solution D; ultrasonically mix and disperse 7-10 parts of methyl methacrylate, 2-3 parts of pentaerythritol tetraacrylate and 0.1-0.3 parts of azobisisobutyronitrile for 5-15 minutes to obtain solution E; add solution E dropwise to solution D and stir at 20-40°C for 5-30 minutes to obtain emulsion F; add emulsion F to emulsion C and continue the reaction at 75-85°C for 5-10 hours.

[0011] (3) 5-10 parts of nano-tungsten doped oxide and 0.1-0.5 parts of polyvinyl pyrrolidone are dispersed in 50-100 parts of deionized water, hydrochloric acid is added to the pH value of 5.5-6.5, ultrasonication is performed for 0.5-1 hour, cleaning, filtration and drying are performed; the dried material is mixed with 1-2 parts of sodium lauryl sulfate in 30-50 parts of deionized water, ultrasonication is performed for 10-30 minutes to obtain dispersion G; dispersion G is added dropwise to the polymer solution obtained in step (2), and stirred until a uniform liquid phase is formed;

[0012] (4) adding 2-5 parts of silane emulsion to the uniform liquid phase obtained in step (3), stirring at 40-50° C. for 1-2 hours; filtering the reaction solution, repeatedly washing, and vacuum drying for 24-48 hours to obtain nano-microcapsules.

[0013] According to one embodiment, in step (1) of the preparation method, the alkyd composite crystals are selected from one of lauric acid / tetradecanol composite crystals and tetradecanol / heptadecanol composite crystals, the alkyd molar ratio is 1:1, and the crystals are obtained by co-melting recrystallization.

[0014] According to one embodiment, in step (1) and step (2) of the method for preparing nanocapsules, the dropping speed is 1-3 mL / min.

[0015] According to one embodiment, in step (3) of the method for preparing nanocapsules, the dropping speed is 3-5 mL / min.

[0016] According to one embodiment, in step (4) of the method for preparing nanocapsules, the silane emulsion is prepared by mixing Tween-40, KH-460, and deionized water in a mass ratio of 3:50:80 until they are uniformly mixed.

[0017] Technical Effect The thermal insulation material and energy storage material of the present application are efficiently and stably compounded in the form of nano-microcapsules to achieve higher thermal insulation and heat preservation, and to achieve the stability of the material. Specifically, the preparation of microcapsules is achieved by emulsion polymerization of alkyd composite crystals and acrylic monomers. During the polymerization process, the alkyd composite crystals are gradually coated with a shell layer mainly composed of methyl methacrylate. Among them, pentaerythritol acrylate is introduced as a cross-linking agent for the microcapsule shell to achieve the reliability and stability of the shell; ethyl acrylate is introduced to adjust the flexibility of the shell. In addition, the monomer hydroxyethyl methacrylate is additionally introduced as an active point for further compounding. At the same time, the surface of the nano-tungsten doped oxide is activated and compounded with the nano-microcapsule shell with active sites via a coupling agent. Its main characteristics are better thermal insulation and heat preservation, and it also has outstanding stability.

[0018] Compared with the prior art, the subsequent examples and test examples will prove that the nano-microcapsule thermal insulation masterbatch of the present application has the following advantages: outstanding thermal insulation performance, good stability, good transparency and clarity when preparing films, and has great application value in the field of energy-saving thermal insulation materials.

[0019] The present invention improves the functionality of the thermal insulation masterbatch and stably and effectively combines the thermal insulation and energy storage materials in the form of microcapsules. It not only increases the upper limit of the thermal insulation capacity by absorbing heat, but also achieves energy storage and thermal insulation performance. At a time when energy conservation and emission reduction are increasingly needed, it plays an important role in promoting social and economic development. DETAILED DESCRIPTION

[0020] The present application will be further described below in conjunction with specific embodiments. These embodiments should be understood to be merely illustrative of the present application and not intended to limit the scope of protection of the present application. After reading the contents of the present application, those skilled in the art may make various changes or modifications to the present application, and these equivalent variations and modifications also fall within the scope defined by the claims of the present application.

[0021] The nano-tungsten doped oxide in this application is a GTO product produced by Shanghai Huzheng Industrial Co., Ltd., code-named G-P100. Other raw materials used in the following examples are commercially available products unless otherwise specified.

[0022] Example 1 Nanocapsules were prepared by the following process:

[0023] (1) 6 g of sodium lauryl sulfate was dissolved in 750 g of deionized water to obtain solution A. 50 g of methyl methacrylate, 10 g of ethyl acrylate, 100 g of lauric acid / tetradecanol composite crystals (molar ratio of alcohol to acid was 1:1), and 1 g of azobisisobutyronitrile were ultrasonically mixed for 10 min to obtain solution B. Solution B was added dropwise to solution A at a rate of 2 mL / min and stirred at 40°C for 20 min to obtain emulsion C. Emulsion C was stirred and reacted at 75°C for 1 h.

[0024] (2) 10 g of sodium lauryl sulfate and 30 g of hydroxyethyl methacrylate were dissolved in 1200 g of deionized water to obtain solution D; 70 g of methyl methacrylate, 20 g of pentaerythritol tetraacrylate, and 1 g of azobisisobutyronitrile were ultrasonically mixed and dispersed for 10 min to obtain solution E; solution E was added dropwise to solution D at a rate of 2 mL / min and stirred at 40°C for 30 min to obtain emulsion F; emulsion F was added to emulsion C and the reaction was continued at 75°C for 7 h;

[0025] (3) 80 g of nano-tungsten doped oxide G-P100 and 2 g of polyvinyl pyrrolidone were dispersed in 800 g of deionized water, hydrochloric acid was added to pH 6.0, ultrasonicated for 0.5 h, washed, filtered and dried; the obtained material was mixed with 10 g of sodium lauryl sulfate in 300 g of deionized water, ultrasonicated for 10 min to obtain dispersion G; dispersion G was added dropwise to the polymer solution at a rate of 3 mL / min and stirred until a uniform liquid phase was formed;

[0026] (4) Tween-40, KH-460, and deionized water were mixed in a mass ratio of 3:50:80 to form a silane emulsion. 30 g of the silane emulsion was added to the polymerization solution and stirred at 40 °C for 2 h. The reaction solution was filtered, washed repeatedly for 3 times, and vacuum dried for 48 h to obtain nanocapsules.

[0027] 100g of nano-microcapsules, 897g of polyethylene glycol plastic slices, 0.8g of ethylene glycol polyoxyethylene ether, 1.2g of pentaerythritol tetrakis-(dibutylhydroxyhydrocinnamate), and 1g of γ-aminopropyltriethoxysilane were added to a plastic granulator while being fully stirred to prepare nano-microcapsule thermal insulation functional masterbatch.

[0028] Example 2 Nanocapsules were prepared by the following process:

[0029] (1) 5 g of sodium lauryl sulfate was dissolved in 800 g of deionized water to obtain solution A; 60 g of methyl methacrylate, 15 g of ethyl acrylate, 12 g of tetradecanoic acid / heptadecanol composite crystals (molar ratio of alcohol to acid was 1:1), and 1 g of azobisisobutyronitrile were ultrasonically mixed for 10 min to obtain solution B; solution B was added dropwise to solution A at a rate of 3 mL / min and stirred at 40°C for 30 min to obtain emulsion C; emulsion C was stirred and reacted at 75°C for 1 h;

[0030] (2) 10 g of sodium lauryl sulfate and 35 g of hydroxyethyl methacrylate were dissolved in 1500 g of deionized water to obtain solution D; 80 g of methyl methacrylate, 30 g of pentaerythritol tetraacrylate, and 1.5 g of azobisisobutyronitrile were ultrasonically mixed and dispersed for 15 min to obtain solution E; solution E was added dropwise to solution D at a rate of 3 mL / min and stirred at 40°C for 30 min to obtain emulsion F; emulsion F was added to emulsion C and the reaction was continued at 80°C for 9 h;

[0031] (3) 90 g of nano-tungsten doped oxide G-P100 and 3 g of polyvinyl pyrrolidone were dispersed in 1000 g of deionized water, hydrochloric acid was added to pH 5.5, ultrasonicated for 1 h, washed, filtered and dried; the obtained material was mixed with 15 g of sodium lauryl sulfate in 400 g of deionized water, ultrasonicated for 30 min to obtain dispersion G; dispersion G was added dropwise to the polymer solution at a rate of 4 mL / min and stirred until a uniform liquid phase was formed;

[0032] (4) Tween-40, KH-460, and deionized water were mixed in a mass ratio of 3:50:80 to form a silane emulsion. 35 g of the silane emulsion was added to the polymerization solution and stirred at 45 °C for 2 h. The reaction solution was filtered, washed repeatedly for 3 times, and vacuum dried for 48 h to obtain nanocapsules.

[0033] 100g of nano-microcapsules, 897g of polypropylene plastic chips, 0.7g of ethylene glycol polyoxyethylene ether, 1.5g of pentaerythritol tetrakis-(dibutylhydroxyhydrocinnamate), and 1g of γ-aminopropyltriethoxysilane were added to a plastic granulator while being fully stirred to prepare a nano-microcapsule heat-insulating masterbatch.

[0034] Example 3 Nanocapsules were prepared by the following process:

[0035] (1) 6 g of sodium lauryl sulfate was dissolved in 800 g of deionized water to obtain solution A; 65 g of methyl methacrylate, 15 g of ethyl acrylate, 14 g of tetradecanoic acid / heptadecanol composite crystals (molar ratio of alcohol to acid was 1:1), and 1 g of azobisisobutyronitrile were ultrasonically mixed for 10 min to obtain solution B; solution B was added dropwise to solution A at a rate of 3 mL / min and stirred at 40°C for 30 min to obtain emulsion C; emulsion C was stirred and reacted at 75°C for 1 h;

[0036] (2) 10 g of sodium lauryl sulfate and 40 g of hydroxyethyl methacrylate were dissolved in 1500 g of deionized water to obtain solution D; 80 g of methyl methacrylate, 30 g of pentaerythritol tetraacrylate, and 1.5 g of azobisisobutyronitrile were ultrasonically mixed and dispersed for 15 min to obtain solution E; solution E was added dropwise to solution D at a rate of 3 mL / min and stirred at 40°C for 30 min to obtain emulsion F; emulsion F was added to emulsion C and the reaction was continued at 80°C for 8 h;

[0037] (3) 80 g of nano-tungsten doped oxide G-P100 and 2 g of polyvinyl pyrrolidone were dispersed in 1000 g of deionized water, hydrochloric acid was added to pH 6.0, ultrasonicated for 1 h, washed, filtered and dried; the obtained material was mixed with 12 g of sodium lauryl sulfate in 400 g of deionized water, ultrasonicated for 30 min to obtain dispersion G; dispersion G was added dropwise to the polymer solution at a rate of 4 mL / min and stirred until a uniform liquid phase was formed;

[0038] (4) Tween-40, KH-460, and deionized water were mixed in a mass ratio of 3:50:80 to form a silane emulsion. 35 g of the silane emulsion was added to the polymerization solution and stirred at 45 °C for 2 h. The reaction solution was filtered, washed repeatedly for 3 times, and vacuum dried for 48 h to obtain nanocapsules.

[0039] 100g of nanocapsules, 897g of polymethyl methacrylate plastic chips, 0.7g of ethylene glycol polyoxyethylene ether, 1.5g of pentaerythritol tetrakis-(dibutylhydroxyhydrocinnamate), and 1g of γ-aminopropyltriethoxysilane were added to a plastic granulator while being thoroughly stirred to prepare a nanocapsule heat-insulating masterbatch.

[0040] The comparative example nano thermal insulation material was prepared by the following method:

[0041] (1) 6 g of sodium lauryl sulfate was dissolved in 800 g of deionized water to obtain solution A; 65 g of methyl methacrylate, 15 g of ethyl acrylate, 14 g of lauric acid / tetradecanol composite crystals (molar ratio of alcohol to acid was 1:1), and 1 g of azobisisobutyronitrile were ultrasonically mixed for 10 min to obtain solution B; solution B was added dropwise to solution A at a rate of 3 mL / min and stirred at 40°C for 30 min to obtain emulsion C; emulsion C was stirred and reacted at 75°C for 1 h;

[0042] (2) 10 g of sodium lauryl sulfate and 40 g of hydroxyethyl methacrylate were dissolved in 1500 g of deionized water to obtain solution D; 80 g of methyl methacrylate, 30 g of pentaerythritol tetraacrylate, and 1.5 g of azobisisobutyronitrile were ultrasonically mixed and dispersed for 15 min to obtain solution E; solution E was added dropwise to solution D at a rate of 3 mL / min and stirred at 40°C for 30 min to obtain emulsion F; emulsion F was added to emulsion C and the reaction was continued at 80°C for 8 h;

[0043] (3) 80 g of nano-tungsten-doped oxide G-P100 was added thereto, and the mixture was mixed until homogeneous. The reaction liquid was filtered, washed repeatedly for 3 times, and vacuum dried for 48 h to obtain a nano-thermal insulation material.

[0044] 100g of nano thermal insulation material, 897g of polymethyl methacrylate plastic chips, 0.7g of ethylene glycol polyoxyethylene ether, 1.5g of pentaerythritol tetrakis-(dibutyl hydroxyhydrocinnamate), and 1g of γ-aminopropyltriethoxysilane were added to a plastic granulator while fully stirring to prepare a comparative thermal insulation functional masterbatch.

[0045] In the experimental examples, the nano-microcapsule thermal insulation masterbatch prepared in each example was co-blended with the corresponding base material masterbatch at a 5% mass ratio and extruded using a biaxial stretching process to produce a 50 μm thick film. The film's performance was tested using a spectrophotometer and an optical transmittance meter to measure infrared rejection and visible light transmittance. The infrared rejection bands tested were 950 nm and 1400 nm.

[0046] Weathering resistance was tested according to the ASTM-D4329-13 accelerated weathering test method. Clarity (haze) was measured using a haze meter. The test results are shown in Table 1. As can be seen, the prepared film exhibits good visible light transmittance and excellent thermal insulation, with a barrier rate of up to 99.9%. Its thermal insulation performance is outstanding, significantly improving over conventional thermal insulation films. The film also exhibits excellent aging resistance, passing the QUV5000h test, demonstrating its outstanding weathering resistance. Regarding clarity, the haze was less than 0.5%, demonstrating excellent clarity. The comparative example used a similar nano-insulation material, but the nano-undoped oxide was not further modified to form an effective composite with the nano-microcapsules, resulting in particle phase separation and migration. This material also exhibited significant compatibility issues. Although visible light transmittance and infrared barrier properties were not significantly affected, its weathering uniformity and compatibility were significantly inferior to those of the examples, resulting in fogging after 5000h of QUV testing. The above tests show that the functional films prepared from the nano-microcapsule thermal insulation functional masterbatch of each embodiment have good transparency, clarity, outstanding stability and good thermal insulation, and have important application value in the field of thermal insulation and energy saving.

[0047] Table 1 Performance test of films prepared from nano-microcapsule thermal insulation masterbatch

[0048] The above content is a detailed description of the present application in conjunction with specific embodiments, and it cannot be considered that the specific implementation of the present application is limited to these descriptions. For those skilled in the art of the present application, without departing from the concept of the present application, they can also make several simple deductions or substitutions, which should be considered to fall within the scope of protection of the present application.

Claims

1. A nano microcapsule, characterized in that: The nano microcapsule is a nano heat insulation material formed by the organic compound of nano tungsten-doped oxide and alkyd composite crystal; The preparation method of the nano microcapsule is as follows: (1) According to the mass ratio, 0.5 - 1 part of sodium dodecyl sulfate is dissolved in 50 - 80 parts of deionized water to form solution A; 5 - 8 parts of methyl methacrylate, 1 - 2 parts of ethyl acrylate, 8 - 15 parts of alkyd composite crystal and 0.1 - 0.2 part of azobisisobutyronitrile are ultrasonically mixed for 5 - 10 min to form solution B; solution B is dropped into solution A, and stirred at 20 - 40 °C for 5 - 30 min to form emulsion C; emulsion C is stirred and reacted at 75 - 85 °C for 0.5 - 1.5 h; (2) 1 - 2 parts of sodium dodecyl sulfate and 1 - 5 parts of 2-hydroxyethyl methacrylate are dissolved in 120 - 150 parts of deionized water to form solution D; 7 - 10 parts of methyl methacrylate, 2 - 3 parts of pentaerythritol tetraacrylate and 0.1 - 0.3 part of azobisisobutyronitrile are ultrasonically mixed and dispersed for 5 - 15 min to form solution E; solution E is dropped into solution D, and stirred at 20 - 40 °C for 5 - 30 min to form emulsion F; emulsion F is added to emulsion C, and the reaction continues at 75 - 85 °C for 5 - 10 h; (3) 5 - 10 parts of nano tungsten-doped oxide and 0.1 - 0.5 part of polyvinylpyrrolidone are dispersed in 50 - 100 parts of deionized water, hydrochloric acid is added until the pH is 5.5 - 6.5, ultrasonically treated for 0.5 - 1 h, washed, filtered and dried; the dried material is mixed with 1 - 2 parts of sodium dodecyl sulfate in 30 - 50 parts of deionized water, ultrasonically treated for 10 - 30 min to form dispersion liquid G; dispersion liquid G is dropped into the polymerization liquid obtained in step (2), and stirred until a uniform liquid phase is formed; (4) 2 - 5 parts of silane emulsion are added to the uniform liquid phase obtained in step (3), stirred at 40 - 50 °C for 1 - 2 h, the reaction liquid is filtered by suction, washed repeatedly, and vacuum dried for 24 - 48 h to obtain nano microcapsules.

2. A nano-microcapsule heat insulation functional masterbatch, characterized in that: The masterbatch is made by mixing a plastic substrate and the nano microcapsule described in claim 1, and adding additives for granulation. The addition amount of the nano microcapsule is 1 - 20 wt% of the masterbatch, and the addition amount of the additive is 0.2 - 0.5 wt% of the masterbatch.

3. The nano-microcapsule heat-insulating functional masterbatch according to claim 2, wherein: In step (1), the alkyd composite crystal is selected from one of lauric acid / tetradecanol composite crystal and myristic acid / heptadecanol composite crystal, the molar ratio of alkyd is 1:1, and obtained by co-melting and recrystallization.

4. The nano-microcapsule heat-insulating masterbatch according to claim 2, wherein: In steps (1) and (2), the dropping rate is 1 - 3 mL / min.

5. The nano-microcapsule heat insulation functional masterbatch according to claim 2, characterized in that: In step (3), the dropping rate is 3 - 5 mL / min.

6. The nano-microcapsule heat insulation functional masterbatch according to claim 2, wherein: In step (4), the silane emulsion is uniformly mixed by Tween-40, KH-460 and deionized water in a mass ratio of 3:50:

80.

7. The nano-microcapsule heat insulation functional masterbatch according to claim 2, wherein: The plastic substrate is selected from polyethylene, polypropylene, polyvinyl chloride, polymethyl methacrylate, polyethylene terephthalate, polystyrene, polycarbonate.

8. The nano-microcapsule heat insulation functional masterbatch according to claim 2 or 7, characterized in that: The additive is a composite of ethylene glycol polyoxyethylene ether, γ-aminopropyltriethoxysilane and pentaerythritol tetra-(dibutylhydroxyhydrocinnamate).

9. The nano-microcapsule heat-insulating functional masterbatch according to claim 2, wherein: The addition amount of the nano microcapsule is 10 wt% of the masterbatch.

10. A heat-insulating functional film, comprising the following raw materials for preparation by mass fraction: 5% of the nano-microcapsule heat-insulating functional masterbatch according to any one of claims 2 to 9 and the balance of the base material masterbatch.

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