Intelligent temperature control polyester for intelligent window and preparation method

Abstract

The invention belongs to the field of functional polyester, particularly relates to polyester with higher visible light transmittance, lower haze and infrared light transmittance capable of being adjusted along with temperature, and relates to intelligent temperature control polyester for an intelligent window and a preparation method. The problems that the phase change temperature of a traditional material is uncontrollable and the process is complex are solved. The intelligent temperature control polyester is composed of terephthalic acid, ethylene glycol, nano vanadium dioxide and derivatives thereof, and germanium dioxide; the mass fraction of the terephthalic acid is 100 parts, the mass fraction of the ethylene glycol is 45-55 parts, the mass fraction of the nano titanium dioxide and the derivative is 0.1-1 part, and the mass fraction of the germanium dioxide is 0.05-0.12 part. The polyester prepared by the invention has higher visible light transmittance, lower haze and infrared light transmittance capable of being adjusted along with temperature, so that the purpose of intelligently adjusting the total amount of solar radiation entering an area is achieved.

Description

Technical Field

[0001] The present invention belongs to the field of functional polyesters, and particularly relates to a polyester with high visible light transmittance, low haze, and infrared light transmittance adjustable with temperature, and to an intelligent temperature-controlled polyester for intelligent windows and a preparation method thereof. Background Art

[0002] Intelligent windows refer to a type of window that uses dynamic regulation, including conditions such as electricity, force, light, and heat, to cause the light transmittance to change as needed. It can save building energy consumption by controlling the total amount of solar radiation indoors and is a technology with a recognized broad prospect. From the classification of building energy consumption, heating, ventilation, and air conditioning (HVAC) systems account for approximately 50% of it. As the main channel for heat exchange between a building and the external environment, windows can account for more than half of the heat flowing into or out of the room. Therefore, how to reduce the heat loss of windows is one of the keys to HVAC energy conservation.

[0003] Existing intelligent temperature control materials (such as electrochromic glass and photochromic coatings) can achieve dynamic regulation, but they rely on external power sources or complex light activation mechanisms, and have defects such as high energy consumption, slow response speed, and high cost. In addition, the phase change temperature window of some materials (such as liquid crystal materials) is uncontrollable, making it difficult to adapt to the usage requirements under different climate conditions.

[0004] Traditional heat insulation films reflect infrared rays through metal coatings, but at the same time, they will significantly reduce the visible light transmittance (usually lower than 70%), resulting in a dim interior and affecting the user experience. Existing intelligent materials need to achieve state switching through current, light, or chemical triggering, cannot autonomously respond to environmental temperature changes, and have high maintenance costs. The phase change thresholds of some temperature control materials are fixed, making it difficult to adapt to the different needs of different regions (such as tropical and temperate regions).

[0005] Therefore, there is an urgent need to propose an intelligent temperature-controlled polyester for intelligent windows and a preparation method thereof to solve the above technical problems. Summary of the Invention

[0006] The present invention is to solve the problems of uncontrollable phase change temperature and complex processes of traditional materials. A brief overview of the present invention is given below to provide a basic understanding of certain aspects of the present invention. It should be understood that this overview is not an exhaustive overview of the present invention. It is not intended to identify the key or important parts of the present invention, nor is it intended to limit the scope of the present invention.

[0007] Technical solution of the present invention:

[0008] An intelligent temperature-controlled polyester for intelligent windows, said intelligent temperature-controlled polyester is composed of terephthalic acid, ethylene glycol, nano-vanadium dioxide and its derivatives, and germanium dioxide;

[0009] The mass fraction of terephthalic acid is 100 parts, the mass fraction of ethylene glycol is 45 - 55 parts, the mass fraction of nano-vanadium dioxide and its derivatives is 0.1 - 1 part, and the mass fraction of germanium dioxide is 0.05 - 0.12 part.

[0010] In some embodiments, the average particle size of nano-vanadium dioxide and its derivatives is not higher than 150 nm, preferably 100 nm, the purity of the nano-vanadium dioxide and its derivatives is greater than 99.5%, and the nano-vanadium dioxide and its derivatives exhibit a monoclinic crystal structure at room temperature. When the temperature exceeds its phase transition temperature, the crystal structure will transform into a tetragonal rutile structure.

[0011] In some embodiments, the nano-vanadium dioxide and its derivatives are one of nano-vanadium dioxide, 1% tungsten-doped nano-vanadium dioxide, 1.5% tungsten-doped nano-vanadium dioxide, and 1% molybdenum-doped nano-vanadium dioxide.

[0012] The phase transition temperature of the pure nano-vanadium dioxide is about 68 °C, that of 1% tungsten-doped nano-vanadium dioxide is about 43 °C, that of 1.5% tungsten-doped nano-vanadium dioxide is about 30 °C, and that of 1% molybdenum-doped nano-vanadium dioxide is about 58 °C.

[0013] In some embodiments, the particle size of germanium dioxide is not higher than 75 μm, and the average particle size is 50 μm, and the purity of germanium dioxide is greater than 99.99%.

[0014] A preparation method of an intelligent temperature-controlled polyester for intelligent windows, comprising the following steps:

[0015] Step 1: Add terephthalic acid, ethylene glycol, nano-vanadium dioxide and its derivatives, and germanium dioxide into a reaction kettle, and purge and discharge nitrogen to remove all air;

[0016] Step 2: Charge nitrogen into the reaction kettle until the pressure reaches 90 - 150 kPa;

[0017] Step 3: Rapidly heat the reaction kettle to 210 - 230 °C, and start stirring to make the pressure in the reaction kettle reach 340 - 360 kPa;

[0018] Step 4: Keep stirring for the esterification reaction and relieve the pressure, and reduce the pressure to 0 kPa within 10 - 130 min;

[0019] Step 5: Under the protection of nitrogen atmosphere, continue stirring and raise the temperature to 270 - 290 °C;

[0020] Step 6: Use a vacuum device to make the pressure in the reaction kettle reach an absolute pressure of 150 - 80 Pa within 50 - 70 min;

[0021] Step 7: Maintain the vacuum condition for polycondensation reaction until the intrinsic viscosity of the polycondensation product reaches 0.7 dL / g. Stop heating, keep stirring, and introduce nitrogen to press out the molten product, and obtain a linear material by water cooling and drawing at 0 - 10 °C;

[0022] Step 8: Granulate and dry the obtained wire material to prepare an intelligent temperature - controlled polyester material.

[0023] In some embodiments, the rate of rapid heating in Step 3 is 3 - 5 °C / min, the stirring speed is 300 - 500 rpm, and nitrogen is added in three equal - gradient supplements during the heating process to maintain the pressure.

[0024] In some embodiments, the pressure - relief process adopts a linear pressure - relief curve, the pressure - relief rate is 2.5 - 3.5 kPa / min, and the fractionating column is opened to recover ethylene glycol when the pressure drops to 50 kPa.

[0025] In some embodiments, the pure water is deionized water with a resistivity ≥ 15 MΩ·cm.

[0026] In some embodiments, underwater pelletizing is used for granulation. The temperature of the pelletizing water is maintained at 5 - 8 °C, the particle size of the obtained particles is 0.2 - 2 mm, and the underwater pelletizing system is preferably a GALA underwater pelletizing system.

[0027] In some embodiments, the granulated material is dried under a vacuum of 80 - 100 Pa at 60 - 80 °C for 6 - 8 h to make the water content ≤ 50 ppm.

[0028] The present invention has the following beneficial effects:

[0029] The polyester prepared by the present invention has a high visible - light transmittance, a low haze, and an infrared - light transmittance that can be adjusted with temperature, so as to achieve the purpose of intelligently adjusting the total amount of solar radiation entering the area, that is, the infrared - light transmittance is high at low temperatures and low at high temperatures, thereby achieving the purpose of adjusting the temperature in the area and reducing the energy consumption for heating or cooling. Specific Embodiments

[0030] To make the purpose, technical solutions, and advantages of the present invention clearer, the present invention is described below through specific examples. However, it should be understood that these descriptions are only exemplary and do not limit the scope of the present invention. In addition, in the following description, the descriptions of well - known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0031] Example 1

[0032] This embodiment discloses a preparation method of intelligent temperature-controlled polyester for intelligent windows, and the specific content is as follows:

[0033] Add 100 parts of terephthalic acid, 50 parts of ethylene glycol, 0.1 part of nano-vanadium dioxide, and 0.05 part of germanium dioxide into a special polyester reaction kettle, and purge nitrogen three times to remove all air; add nitrogen until the pressure in the reaction kettle reaches 120 kPa; stir and quickly heat up to 220 °C and the pressure reaches 350 kPa; keep stirring and start the esterification reaction and slowly relieve the pressure, and reduce the pressure to 0 kPa within 120 min; under the protection of a nitrogen atmosphere, stir and quickly heat up to 280 °C; use a vacuum pumping device to make the absolute pressure in the reaction kettle reach 80 Pa within 60 min; keep the vacuum degree until the intrinsic viscosity at the end of polycondensation is ≥ 0.7 dL / g, keep heating and turn off the stirring, introduce nitrogen to press out the product, and the product flows into pure water at 0 °C for wire drawing; granulate and dry the wire material to obtain the polyester.

[0034] Example 2

[0035] This embodiment discloses a preparation method of intelligent temperature-controlled polyester for intelligent windows, and the specific content is as follows:

[0036] Add 100 parts of terephthalic acid, 50 parts of ethylene glycol, 1 part of nano-vanadium dioxide, and 0.12 part of germanium dioxide into a special polyester reaction kettle, and purge nitrogen three times to remove all air; add nitrogen until the pressure in the reaction kettle reaches 90 kPa; stir and quickly heat up to 210 °C and the pressure reaches 340 kPa; keep stirring and start the esterification reaction and slowly relieve the pressure, and reduce the pressure to 0 kPa within 110 min; under the protection of a nitrogen atmosphere, stir and quickly heat up to 270 °C; use a vacuum pumping device to make the absolute pressure in the reaction kettle reach 150 Pa within 50 min; keep the vacuum degree until the intrinsic viscosity at the end of polycondensation is ≥ 0.7 dL / g, keep heating and turn off the stirring, introduce nitrogen to press out the product, and the product flows into pure water at 10 °C for wire drawing; granulate and dry the wire material to obtain the polyester.

[0037] Example 3

[0038] This embodiment discloses a preparation method of intelligent temperature-controlled polyester for intelligent windows, and the specific content is as follows:

[0039] Add 100 parts of terephthalic acid, 50 parts of ethylene glycol, 1 part of nano-vanadium dioxide, and 0.075 part of germanium dioxide into a special polyester reaction kettle, and purge nitrogen three times to remove all air; add nitrogen until the pressure in the reaction kettle reaches 150 kPa; stir and quickly heat up to 230 °C and the pressure reaches 360 kPa; keep stirring and start the esterification reaction and slowly release the pressure, and reduce the pressure to 0 kPa within 130 min; under the protection of a nitrogen atmosphere, stir and quickly heat up to 290 °C; use a vacuum pumping device to make the absolute pressure in the reaction kettle reach 100 Pa within 70 min; keep the vacuum degree until the intrinsic viscosity at the end of polycondensation is ≥ 0.7 dL / g, keep heating and turn off the stirring, introduce nitrogen to press out the product, and let the product flow into pure water at 5 °C for wire drawing; granulate and dry the wire material to obtain the polyester.

[0040] Example 4

[0041] This example discloses a preparation method of an intelligent temperature-controlled polyester for intelligent windows, and the specific content is as follows:

[0042] Add 100 parts of terephthalic acid, 50 parts of ethylene glycol, 0.5 part of nano-vanadium dioxide, and 0.075 part of germanium oxide into a special polyester reaction kettle, and purge nitrogen three times to remove all air; add nitrogen until the pressure in the reaction kettle reaches 120 kPa; stir and quickly heat up to 220 °C and the pressure reaches 350 kPa; keep stirring and start the esterification reaction and slowly release the pressure, and reduce the pressure to 0 kPa within 120 min; under the protection of a nitrogen atmosphere, stir and quickly heat up to 280 °C; use a vacuum pumping device to make the absolute pressure in the reaction kettle reach 80 Pa within 60 min; keep the vacuum degree until the intrinsic viscosity at the end of polycondensation is ≥ 0.7 dL / g, keep heating and turn off the stirring, introduce nitrogen to press out the product, and let the product flow into pure water at 0 °C for wire drawing; granulate and dry the wire material to obtain the polyester.

[0043] Example 5

[0044] This example discloses a preparation method of an intelligent temperature-controlled polyester for intelligent windows, and the specific content is as follows:

[0045] 100 parts of terephthalic acid, 50 parts of ethylene glycol, 0.5 part of 1% tungsten-doped nanometer vanadium dioxide, and 0.075 part of germanium oxide are added into a special polyester reaction kettle. Nitrogen is purged three times to remove all air. Nitrogen is added until the pressure in the reaction kettle reaches 120 kPa. Stir and rapidly heat up to 220 °C and the pressure reaches 350 kPa. Keep stirring to start the esterification reaction and slowly relieve the pressure, and reduce the pressure to 0 kPa within 120 min. Under the protection of a nitrogen atmosphere, stir and rapidly heat up to 280 °C. Use a vacuum pumping device to make the absolute pressure in the reaction kettle reach 80 Pa within 60 min. Keep the vacuum degree until the intrinsic viscosity at the end of polycondensation is ≥ 0.7 dL / g. Keep heating and turn off the stirring, and introduce nitrogen to press out the product. The product flows into pure water at 0 °C for wire drawing. The wire material is granulated and dried to obtain the polyester.

[0046] Example 6

[0047] This example discloses a preparation method of an intelligent temperature-controlled polyester for intelligent windows, and the specific content is as follows:

[0048] 100 parts of terephthalic acid, 50 parts of ethylene glycol, 0.5 part of 1% molybdenum-doped nanometer vanadium dioxide, and 0.075 part of germanium oxide are added into a special polyester reaction kettle. Nitrogen is purged three times to remove all air. Nitrogen is added until the pressure in the reaction kettle reaches 120 kPa. Stir and rapidly heat up to 220 °C and the pressure reaches 350 kPa. Keep stirring to start the esterification reaction and slowly relieve the pressure, and reduce the pressure to 0 kPa within 120 min. Under the protection of a nitrogen atmosphere, stir and rapidly heat up to 280 °C. Use a vacuum pumping device to make the absolute pressure in the reaction kettle reach 80 Pa within 60 min. Keep the vacuum degree until the intrinsic viscosity at the end of polycondensation is ≥ 0.7 dL / g. Keep heating and turn off the stirring, and introduce nitrogen to press out the product. The product flows into pure water at 0 °C for wire drawing. The wire material is granulated and dried to obtain the polyester.

[0049] Comparative Example 1

[0050] This example discloses a preparation method of a polyester, and the specific content is as follows:

[0051] Add 100 parts of terephthalic acid, 50 parts of ethylene glycol, and 0.03 part of germanium oxide into a special polyester reaction kettle, and purge nitrogen three times to remove all air; add nitrogen until the pressure in the reaction kettle reaches 120 kPa; stir and quickly heat up to 220 °C and the pressure reaches 350 kPa; keep stirring and start the esterification reaction and slowly release the pressure, and reduce the pressure to 0 kPa within 120 min; under the protection of a nitrogen atmosphere, stir and quickly heat up to 280 °C; use a vacuum pumping device to make the absolute pressure in the reaction kettle reach 80 Pa within 60 min; maintain the vacuum until the intrinsic viscosity at the end of polycondensation is ≥ 0.7 dL / g, keep heating and turn off the stirring, introduce nitrogen to press out the product, and the product flows into pure water at 0 °C for drawing; granulate and dry the wire material to obtain the polyester.

[0052] Comparative Example 2

[0053] This example discloses a method for preparing polyester, and the specific content is as follows:

[0054] Add 100 parts of phthalic acid, 50 parts of ethylene glycol, and 0.03 part of germanium oxide into a special polyester reaction kettle, and purge nitrogen three times to remove all air; add nitrogen until the pressure in the reaction kettle reaches 120 kPa; stir and quickly heat up to 220 °C and the pressure reaches 350 kPa; keep stirring and start the esterification reaction and slowly release the pressure, and reduce the pressure to 0 kPa within 120 min; under the protection of a nitrogen atmosphere, stir and quickly heat up to 280 °C; use a vacuum pumping device to make the absolute pressure in the reaction kettle reach 80 Pa within 60 min; maintain the vacuum until the intrinsic viscosity at the end of polycondensation is ≥ 0.7 dL / g, keep heating and turn off the stirring, introduce nitrogen to press out the product, and the product flows into pure water at 0 °C for drawing; granulate and dry the wire material to obtain the polyester.

[0055] Comparative Example 3

[0056] This example discloses a method for preparing polyester, and the specific content is as follows:

[0057] Add 100 parts of phthalic acid, 50 parts of ethylene glycol, 4 parts of nano-vanadium dioxide, and 0.03 part of germanium oxide into a special polyester reaction kettle, and purge nitrogen three times to remove all air; add nitrogen until the pressure in the reaction kettle reaches 120 kPa; stir and quickly heat up to 220 °C and the pressure reaches 350 kPa; keep stirring and start the esterification reaction and slowly release the pressure, and reduce the pressure to 0 kPa within 120 min; under the protection of a nitrogen atmosphere, stir and quickly heat up to 280 °C; use a vacuum pumping device to make the absolute pressure in the reaction kettle reach 80 Pa within 60 min; maintain the vacuum until the intrinsic viscosity at the end of polycondensation is ≥ 0.7 dL / g, keep heating and turn off the stirring, introduce nitrogen to press out the product, and the product flows into pure water at 0 °C for drawing; granulate and dry the wire material to obtain the polyester.

[0058] Performance tests were conducted on the polyester films provided in the examples and comparative examples. The test methods are as follows:

[0059] 1. Total light transmittance / haze test: A stainless-steel mold was used for hot pressing at 280 °C in a molten state, and then quenched with ice water to form a film with a thickness of 1 mm. After drying it in a vacuum at 40 °C for 5 h, a sapphire flat mold was used in a flat vulcanizer preheated to 80 °C, and pressed at a pressure of 5 MPa for 10 min, and then cooled naturally to room temperature under this pressure to obtain a polyester optical property test film with a high-precision optical plane. The total light transmittance and haze were tested at 25 °C using a WGT-2S light transmittance / haze meter, in the C light source mode.

[0060] 2. Full-spectrum transmittance test: The copolyester was dried at 40 °C for 8 h, and the transmittance in the wavelength range of 200 nm to 1000 nm was tested at 25 °C using a UV-3600 ultraviolet-visible-near-infrared spectrophotometer (Shimadzu, Japan), with a wavelength interval of 0.5 nm.

[0061] The performance test results are shown in Table 1

[0062]

[0063] As can be seen from Table 1, when vanadium dioxide nanometer and germanium dioxide act synergistically, the prepared polyester film has a high visible light transmittance, a low haze, and an infrared light transmittance that can be adjusted with temperature. Moreover, after returning to room temperature from above the phase transition temperature, it can still maintain a good infrared light transmittance and has good repeatability.

[0064] In summary, when the polyester product provided by this invention is used in the field of intelligent window films, such as: building window films, automotive glass films, etc., it can achieve the purpose of intelligently adjusting the total amount of solar radiation entering the area, that is, the infrared light transmittance is high at low temperatures and low at high temperatures, thereby achieving the purpose of adjusting the temperature in the area and reducing the energy consumption for heating or cooling.

[0065] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be arranged and combined. Those skilled in the art can exhaust all possibilities based on the mathematical knowledge of permutations and combinations. Therefore, this invention will no longer explain the technical solutions after permutation and combination one by one, but it should be understood that the technical solutions after permutation and combination have been disclosed by this invention.

[0066] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An intelligent temperature-controlled polyester for intelligent windows, characterized in that: The intelligent temperature-controlled polyester is composed of terephthalic acid, ethylene glycol, nano-vanadium dioxide and its derivatives, and germanium dioxide; The mass fraction of terephthalic acid is 100 parts, the mass fraction of ethylene glycol is 45 - 55 parts, the mass fraction of nano-vanadium dioxide and its derivatives is 0.1 - 1 part, and the mass fraction of germanium dioxide is 0.05 - 0.12 part.

2. The intelligent temperature control polyester for intelligent windows according to claim 1, wherein: The average particle size of the nano-vanadium dioxide and its derivatives is 100 nm, the purity of the nano-vanadium dioxide and its derivatives is greater than 99.5%, the nano-vanadium dioxide and its derivatives present a monoclinic crystal structure at room temperature, and when the temperature exceeds its phase transition temperature, the crystal structure will transform into a tetragonal rutile structure.

3. The intelligent temperature-controlled polyester for intelligent windows according to claim 1 is characterized in that: The nano-vanadium dioxide and its derivatives are one of nano-vanadium dioxide, 1% tungsten-doped nano-vanadium dioxide, 1.5% tungsten-doped nano-vanadium dioxide, and 1% molybdenum-doped nano-vanadium dioxide.

4. The intelligent temperature-controlled polyester for intelligent windows according to claim 1, wherein: The average particle size of the germanium dioxide is 50 μm, and the purity of the germanium dioxide is greater than 99.99%.

5. A preparation method of intelligent temperature-controlled polyester for intelligent windows, characterized in that, It includes the following steps: Step 1: Add terephthalic acid, ethylene glycol, nano-vanadium dioxide and its derivatives, and germanium dioxide into the reaction kettle, and purge nitrogen to remove all air; Step 2: Charge nitrogen into the reaction kettle until the pressure reaches 90 - 150 kPa; Step 3: Heat up the reaction kettle and start stirring to make the pressure in the reaction kettle reach 340 - 360 kPa; Step 4: Keep stirring for the esterification reaction and relieve the pressure to reduce the pressure to atmospheric pressure; Step 5: Under the protection of nitrogen atmosphere, continue stirring and raise the temperature to 270 - 290 °C; Step 6: Use a vacuum pumping device to make the pressure in the reaction kettle reach the absolute pressure; Step 7: Maintain the vacuum condition for the polycondensation reaction until the intrinsic viscosity of the polycondensation product reaches 0.7 dL / g, stop heating, keep stirring and introduce nitrogen to extrude the molten product, and obtain a linear material through pure water cooling and drawing; Step 8: Granulate and dry the obtained wire material to produce the intelligent temperature-controlled polyester material.

6. The preparation method of an intelligent temperature control polyester for intelligent windows according to claim 5, characterized in that: In Step 3, the reaction kettle is heated to 210 - 230 °C.

7. The preparation method of an intelligent temperature control polyester for intelligent windows according to claim 5, characterized in that: In Step 4, the pressure in the reaction kettle is reduced to atmospheric pressure within 10 - 130 min.

8. The preparation method of an intelligent temperature-controlled polyester for intelligent windows according to claim 5, characterized in that: In Step 6, the pressure in the reaction kettle reaches the absolute pressure within 50 - 70 min, and the absolute pressure is 150 - 80 Pa.

9. The preparation method of an intelligent temperature control polyester for an intelligent window according to claim 5, characterized in that: In Step 7, the temperature of the pure water is 0 - 10 °C.

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