High-temperature-resistant coating, PVC (polyvinyl chloride) common permeable membrane containing high-temperature-resistant coating and production process

Abstract

The invention discloses a high-temperature-resistant coating, a PVC common permeable membrane containing the high-temperature-resistant coating and a production process, and belongs to the technical field of functional polymer materials, PVC resin, a methyl tin stabilizer and zinc stearate are pressed and molded, then the high-temperature-resistant coating is sprayed on the surface, silicon dioxide is used as a sacrificial template on the surface of polystyrene microspheres, and the high-temperature-resistant coating is prepared. The hollow macroporous carbon microspheres with large aperture are obtained, the repairing agent and the curing agent are fixed in the hollow macroporous carbon microspheres to form a microcapsule structure, and microcapsules have good thermal conductivity and strength, so that the thermal conductivity and the overall strength of the material can be remarkably improved; the microcapsule is coated with a cellulose modified polycaprolactone layer, cellulose is a natural polymer material and has rich hydroxyl groups, the functional groups can enhance the interface bonding with a PVC matrix, when the microcapsule is in contact with high temperature, the polycaprolactone layer loses the structural integrity, but the structure of the microcapsule is not damaged, so that the microcapsule is not prone to cracking, and the service life of the microcapsule is prolonged. And the long-term stability of the coating strength can be maintained.

Description

Technical Field

[0001] The invention belongs to the technical field of functional polymer materials, and in particular relates to a high temperature resistant coating, a PVC normal transparent film containing the coating and a production process. Background Art

[0002] PVC normal transparent film is a film made of polyvinyl chloride as the main material. It has light transmittance and certain air permeability. This film is widely used in packaging, agriculture, construction, medical and other fields. At present, PVC normal transparent film is usually used in dining tables, desks or coffee tables and other occasions. It has excellent waterproof and oil-proof properties, and can effectively prevent soup, grease and other liquids from eroding the surface of the dining table and protecting the dining table from damage. PVC normal transparent film can withstand a temperature of 60°C and is not easily deformed or damaged by hot food or hot drinks. However, if it is in contact with hot plates and pots just out of the oven for a long time, the local temperature will reach 85°C, causing the PVC normal transparent film to soften and deform, reducing its service life.

[0003] A Chinese patent with announcement number CN116716042B announces a high-temperature resistant coating and a preparation method thereof. By performing specific pretreatment / surface modification on hollow glass microspheres, the dispersibility and stability of the hollow glass microspheres in the coating system are improved, and the method of introducing a metal bonding layer in the prior art is abandoned. The property of organic polysilazane reacting with the hydroxyl groups on the surface of the substrate to form a strong chemical bond is utilized to improve the bonding strength and compatibility between the coating and the substrate. However, in this scheme, the substrate is a sandpaper-ground carbon fiber reinforced epoxy resin composite material. Although grinding can increase the roughness of the composite material, it will cause local peeling of the interface between the carbon fiber and the epoxy resin to form a weak bonding area, and the surface hydroxyl density of the cured epoxy resin is low, and it relies on the reaction of organic polysilazane with the hydroxyl groups on the surface of the epoxy resin to form a strong chemical bond, thereby failing to achieve good bonding between the coating and the substrate. Summary of the invention

[0004] The purpose of the present invention is to provide a high-temperature resistant coating, a PVC permeable film containing the coating and a production process. The high-temperature resistant coating of a thermally responsive two-component microcapsule is obtained by spraying the surface with silicon dioxide after pressing and forming a PVC resin, a methyl tin stabilizer and zinc stearate, depositing silicon dioxide on the surface of a micron-sized polystyrene microsphere, and then using silicon dioxide as a macroporous sacrificial template to obtain a hollow macroporous carbon microsphere with a large pore size. The hollow macroporous carbon microsphere is used as a first-layer structure, and a repair agent and a curing agent are fixed in the hollow macroporous carbon microsphere to form a microcapsule structure. The microcapsule has good thermal conductivity and strength, can significantly increase the thermal conductivity of the coating in the PVC permeable film, and improve the overall strength of the material; a layer of cellulose-modified polycaprolactone is wrapped outside the microcapsule as a second-layer structure. Cellulose is a natural polymer material with rich hydroxyl functional groups, and these functional groups can enhance the interface bonding with the PVC matrix.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A high temperature resistant coating is prepared by the following steps:

[0007] Add 1-butyl-3-methylimidazole chloride to the reactor, stir and melt, then add cellulose microcrystals under a nitrogen atmosphere, continue stirring for 1-2 hours, then add ε-caprolactone and stannous octoate, heat in an oil bath, continue to react for 2-4 hours, then add microcapsule repair agent and microcapsule curing agent, continue stirring for 1-2 hours, add sodium dodecylbenzene sulfonate and polyethylene glycol to the reactor, continue stirring for 3-4 hours, centrifuge, discard the supernatant, wash, and vacuum dry to obtain a high temperature resistant coating of thermally responsive two-component microcapsules with a particle size of 40-60 μm.

[0008] Furthermore, the usage ratio of 1-butyl-3-methylimidazole chloride, cellulose microcrystals, ε-caprolactone, stannous octoate, microcapsule repair agent, microcapsule curing agent, sodium dodecylbenzene sulfonate and polyethylene glycol is 3-4kg: 1-2kg: 800-900mL: 30-35g: 1-2kg: 500-600g: 25-28g: 50-60mL.

[0009] Further, the microcapsule repair agent is prepared by the following steps:

[0010] Add hollow macroporous carbon microspheres, sodium dodecylbenzene sulfonate, polyethylene glycol and deionized water into a reactor, ultrasonically disperse for 40-60 minutes, stir at 20-25°C and 400-500r / min for 5-6 hours, filter, wash the filter cake with deionized water and anhydrous ethanol for 2-3 times respectively, and vacuum dry to obtain dispersed hollow macroporous carbon microspheres; add dispersed hollow macroporous carbon microspheres, epoxy resin and acetone into a reactor, ultrasonically disperse for 40-60 minutes, seal, immerse for 30-40 minutes at 20-25°C and 500-600r / min, heat to 70-80°C and continue stirring for 1-2 hours, remove acetone, and obtain a microcapsule repair agent.

[0011] Furthermore, the usage ratio of the hollow macroporous carbon microspheres, sodium dodecylbenzene sulfonate, polyethylene glycol and deionized water is 5-6 kg: 80-90 g: 50-60 mL: 4-5 L.

[0012] Furthermore, the usage ratio of the dispersed hollow macroporous carbon microspheres, epoxy resin and acetone is 1-1.2 kg: 500-600 g: 4-5 L.

[0013] Further, the microcapsule curing agent is prepared by the following steps:

[0014] Dispersed hollow macroporous carbon microspheres, anhydrous ethanol and 2-methylimidazole are added into a reaction kettle, ultrasonically dispersed for 40-60 minutes, sealed, immersed for 30-40 minutes at 20-25°C and 500-600r / min, heated to 70-80°C and stirred for 1-2 hours, and anhydrous ethanol is removed to obtain a microcapsule curing agent.

[0015] Furthermore, the usage ratio of dispersed hollow macroporous carbon microspheres, anhydrous ethanol and 2-methylimidazole is 1-1.2 kg: 3-4 L: 400-500 g.

[0016] Further, the hollow macroporous carbon microspheres are prepared by the following steps:

[0017] Phenolic resin, acetylacetone, polyoxyethylene-polyoxypropylene copolymer as a macropore directing agent and ethanol solution with a mass fraction of 20-30% are added to the reaction kettle, stirred at 20-25°C and 500-600r / min for 20-30min, then silicon dioxide / carbon microspheres are added, sealed, immersed at 50-65°C and 500-600r / min for 12-14h, filtered, and the filter cake is washed with deionized water and anhydrous The mixture was washed with ethanol for 2-3 times, vacuum dried at 60-80°C for 1-2h, heated to 100-110°C for curing for 24-26h, heated to 350-360°C in an argon atmosphere, kept warm for 2-3h, heated to 900-920°C at a rate of 5-6°C / min, kept warm for 2-3h, and the product was washed 2-3 times with a hydrofluoric acid solution with a mass fraction of 5-6% to obtain hollow macroporous carbon microspheres with a pore size of 250-300nm.

[0018] Furthermore, the usage ratio of phenolic resin, acetylacetone, polyoxyethylene-polyoxypropylene copolymer, ethanol solution and silicon dioxide / carbon microspheres is 1-2 kg: 700-800 mL: 300-320 mL: 4-6 L: 2-3 kg.

[0019] Further, the silicon dioxide / carbon microspheres are prepared by the following steps:

[0020] Add polystyrene microspheres with a particle size of 20-30 μm and deionized water into a reactor, stir for 2-3 hours at 20-25° C. and 500-600 r / min, then add tetraethyl orthosilicate, anhydrous ethanol and 50-60% ammonia water by mass, stir for 12-14 hours at 40-45° C. and 500-600 r / min, filter, wash the filter cake with deionized water and anhydrous ethanol for 2-3 times respectively, vacuum dry at 60-80° C. for 1-2 hours, transfer to a muffle furnace, and calcine at 750-800° C. for 12-14 hours under an argon atmosphere to obtain silica / carbon microspheres.

[0021] Furthermore, the usage ratio of polystyrene microspheres, deionized water, tetraethyl orthosilicate, anhydrous ethanol and ammonia water is 3-4 kg: 5-6 L: 500-600 mL: 800-900 mL: 850-900 mL.

[0022] A production process of a PVC ordinary transparent film with a high temperature resistant coating is prepared by the following steps:

[0023] The PVC resin, methyl tin stabilizer and zinc stearate were mixed evenly in a mass ratio of 60-80:1-3:2-3, and then mixed and plasticized for 10-12 minutes at 180-190°C using a double-roll open mill. The obtained sheet was pressed and formed using a four-roll calender at 180-190°C, cooled naturally to 40-45°C, and the high temperature resistant coating was coated at 200-300mL / m 2 The amount of the coating is sprayed on the formed material, dried at 40-45°C for 50-80 minutes, cooled and rolled up to obtain a high temperature resistant coating and a PVC ordinary transparent film containing the coating.

[0024] Beneficial effects of the present invention:

[0025] 1. The PVC ordinary transparent film prepared by the present invention is obtained by pressing and pasting PVC resin, methyl tin stabilizer and zinc stearate and then spraying a high-temperature resistant coating of thermally responsive two-component microcapsules on the surface. It has good heat resistance, high overall strength, close bonding with the matrix and is not easy to peel off.

[0026] 2. The hollow macroporous carbon microspheres of the present invention are prepared by depositing silica on the surface of micron-sized polystyrene microspheres, using silica as a macroporous template, using a nonionic surfactant polyoxyethylene-polyoxypropylene copolymer as a mesopore directing agent, and using a phenolic resin as a carbon source to obtain hollow macroporous carbon microspheres with a pore size of 250-300 nm. The repair agent and the curing agent are fixed in the hollow macroporous carbon microspheres to form a microcapsule structure, which can prevent the migration of the curing agent in the coating due to environmental factors, resulting in uneven local curing agent concentration and affecting the repair effect. The curing agent is often sensitive to external environmental conditions, and the microencapsulation technology can effectively isolate the curing agent from direct contact with the external environment.

[0027] 3. A layer of cellulose-modified polycaprolactone is wrapped around the microcapsule as the second layer structure. Cellulose is a natural polymer material with rich hydroxyl functional groups. These functional groups can enhance the interfacial bonding with the PVC matrix. During use, long-term contact with hot plates just out of the pot will cause the outermost polycaprolactone layer to lose its structural integrity, thereby releasing the epoxy resin repair agent in the pores of the hollow carbon balls to repair the coating and extend the service life of the PVC normal transparent film; the surface of the microcapsule is rich in hydroxyl and carboxyl functional groups. Even if the outer layer of polycaprolactone loses its structural integrity, these functional groups can still ensure good bonding between the microcapsule and the matrix material.

[0028] 4. The thermally responsive two-component microcapsule of the present invention uses hollow macroporous carbon microspheres as the first layer structure to fix the repair agent and the curing agent in the microcapsule core. The hollow macroporous carbon microspheres have good thermal conductivity and strength, can significantly increase the thermal conductivity of the coating in the PVC ordinary transparent film, and improve the overall strength of the material. When exposed to high temperature, the polycaprolactone layer loses its structural integrity, but the structure of the hollow macroporous carbon microspheres will not be destroyed, thereby maintaining the stability of the material strength and extending the service life. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Embodiment 1: A production process of a PVC transparent film containing a high temperature resistant coating, comprising the following steps:

[0031] S1: Add 3 kg of polystyrene microspheres with a particle size of 20-30 μm and 5 L of deionized water into a reactor, stir at 20°C and 500 r / min for 2 h, then add 500 mL of tetraethyl orthosilicate, 800 mL of anhydrous ethanol and 850 mL of 50% ammonia water, stir at 40°C and 500 r / min for 12 h, filter, wash the filter cake with deionized water and anhydrous ethanol twice respectively, dry it in vacuum at 60°C for 1 h, transfer it to a muffle furnace, and calcine it at 750°C for 12 h under argon atmosphere to obtain silica / carbon microspheres.

[0032] S2: 1 kg of phenolic resin, 700 mL of acetylacetone, 300 mL of polyoxyethylene-polyoxypropylene copolymer as a macropore directing agent and 4 L of 20% ethanol solution were added into the reactor, stirred at 20°C and 500 r / min for 20 min, then 2 kg of silica / carbon microspheres were added, sealed, immersed at 50°C and 500 r / min for 12 h, filtered, the filter cake was washed twice with deionized water and anhydrous ethanol respectively, vacuum dried at 60°C for 1 h, heated to 100°C for curing for 24 h, heated to 350°C under argon atmosphere, kept warm for 2 h, heated to 900°C at a rate of 5°C / min, kept warm for 2 h, and the product was washed twice with 5% hydrofluoric acid solution to obtain hollow macroporous carbon microspheres with a pore size of 250-300 nm.

[0033] Silica is deposited on the surface of micron-sized polystyrene microspheres through carboxyl and hydroxyl functional groups, and then silica is used as a macroporous template, non-ionic surfactant polyoxyethylene polyoxypropylene copolymer is used as a mesopore directing agent, and phenolic resin is used as a carbon source to obtain hollow macroporous carbon microspheres with a pore size of 250-300nm.

[0034] S3: Add 5 kg of hollow macroporous carbon microspheres, 80 g of sodium dodecylbenzene sulfonate, 50 mL of polyethylene glycol with a molecular weight of 500 and 4 L of deionized water into a reactor, ultrasonically disperse for 40 min, stir for 5 h at 20 ° C and 400 r / min, filter, wash the filter cake with deionized water and anhydrous ethanol twice respectively, and vacuum dry at 60 ° C for 1 h to obtain dispersed hollow macroporous carbon microspheres; add 1 kg of dispersed hollow macroporous carbon microspheres, 500 g of epoxy resin and 4 L of acetone into a reactor, ultrasonically disperse for 40 min, seal, immerse for 30 min at 20 ° C and 500 r / min, heat to 70 ° C and continue stirring for 1 h, remove acetone, and obtain a microcapsule repair agent.

[0035] S4: 1 kg of dispersed hollow macroporous carbon microspheres, 3 L of anhydrous ethanol and 400 g of 2-methylimidazole were added to the reactor, ultrasonically dispersed for 40 min, sealed, immersed for 30 min at 20 ° C and 500 r / min, heated to 70 ° C, continued stirring for 1 h, removed anhydrous ethanol, and obtained a microcapsule curing agent.

[0036] S5: Add 3kg of 1-butyl-3-methylimidazole chloride into the reactor, stir and melt at 70°C and 500r / min, then add 1kg of cellulose microcrystals under nitrogen atmosphere, continue stirring for 1h, then add 800mL of ε-caprolactone and 30g of catalyst stannous octoate, heat the oil bath to 95°C, continue reacting for 2h, then add 1kg of microcapsule repair agent and 500g of microcapsule curing agent, stir at 20°C and 800r / min for 1h, add 25g of sodium dodecylbenzene sulfonate and 50mL of polyethylene glycol with a molecular weight of 500 into the reactor, continue stirring for 3h, centrifuge at 3500r / min for 5min, discard the supernatant, wash the product with deionized water and anhydrous ethanol twice respectively, and dry it in vacuum at 60°C for 1h to obtain a high temperature resistant coating of thermally responsive two-component microcapsules with a particle size of 40μm.

[0037] 1-Butyl-3-methylimidazole chloride was used as a solvent for dissolving and chemically modifying cellulose microcrystals, and polycaprolactone was modified by cellulose microcrystals through ring-opening polymerization catalyzed by stannous octoate.

[0038] S6: PVC resin, methyl tin stabilizer and zinc stearate were mixed uniformly in a mass ratio of 60:1:2, and then mixed and plasticized at 180°C for 10 minutes using a two-roll open mill. The obtained sheet was pressed and formed using a four-roll calender at 180°C, cooled naturally to 40°C, and the high temperature resistant coating of the thermal responsive two-component microcapsule was coated at 200mL / m 2 The amount of the coating is sprayed on the formed material, dried at 40°C for 50 minutes, cooled and rolled up to obtain a high temperature resistant coating and a PVC ordinary transparent film containing the coating.

[0039] Embodiment 2: A production process of a PVC transparent film containing a high temperature resistant coating, comprising the following steps:

[0040] S1: 3.5 kg of polystyrene microspheres with a particle size of 20-30 μm and 5.5 L of deionized water were added into a reactor, stirred at 22.5°C and 550 r / min for 2.5 h, then 550 mL of tetraethyl orthosilicate, 850 mL of anhydrous ethanol and 875 mL of 55% ammonia water were added, stirred at 42.5°C and 550 r / min for 13 h, filtered, and the filter cake was washed twice with deionized water and anhydrous ethanol respectively, dried under vacuum at 70°C for 1.5 h, transferred to a muffle furnace, and calcined at 775°C for 13 h under an argon atmosphere to obtain silica / carbon microspheres.

[0041] S2: 1.5 kg phenolic resin, 750 mL acetylacetone, 310 mL polyoxyethylene polyoxypropylene copolymer as a macropore directing agent and 5 L ethanol solution with a mass fraction of 25% were added to the reactor, stirred at 22.5 ° C and 550 r / min for 25 minutes, and then 2.5 kg silica / carbon microspheres were added, sealed, immersed at 57.5 ° C and 550 r / min for 13 hours, filtered, the filter cake was washed twice with deionized water and anhydrous ethanol respectively, vacuum dried at 70 ° C for 1.5 hours, heated to 105 ° C for curing for 25 hours, heated to 355 ° C in an argon atmosphere, kept warm for 2.5 hours, heated to 910 ° C at a rate of 5.5 ° C / min, kept warm for 2.5 hours, and the product was washed twice with a hydrofluoric acid solution with a mass fraction of 5.5% to obtain hollow macroporous carbon microspheres with a pore size of 250-300 nm.

[0042] S3: Add 5.5 kg of hollow macroporous carbon microspheres, 85 g of sodium dodecylbenzene sulfonate, 55 mL of polyethylene glycol with a molecular weight of 600 and 4.5 L of deionized water into a reactor, ultrasonically disperse for 50 min, stir for 5.5 h at 22.5 ° C and 450 r / min, filter, wash the filter cake with deionized water and anhydrous ethanol for 2.5 times respectively, and vacuum dry at 70 ° C for 1.5 h to obtain dispersed hollow macroporous carbon microspheres; add 1.1 kg of dispersed hollow macroporous carbon microspheres, 550 g of epoxy resin and 4.5 L of acetone into a reactor, ultrasonically disperse for 50 min, seal, immerse for 35 min at 22.5 ° C and 550 r / min, heat to 75 ° C and continue stirring for 1.5 h, remove acetone, and obtain a microcapsule repair agent.

[0043] S4: 1.1 kg of dispersed hollow macroporous carbon microspheres, 3.5 L of anhydrous ethanol and 450 g of 2-methylimidazole were added to the reactor, ultrasonically dispersed for 50 min, sealed, immersed for 35 min at 22.5 ° C and 550 r / min, heated to 75 ° C, continued stirring for 1.5 h, removed anhydrous ethanol, and obtained a microcapsule curing agent.

[0044] S5: Add 3.5 kg of 1-butyl-3-methylimidazole chloride into the reactor, stir and melt at 75°C and 550 r / min, then add 1.5 kg of cellulose microcrystals under a nitrogen atmosphere, continue stirring for 1.5 h, then add 850 mL of ε-caprolactone and 32.5 g of catalyst stannous octoate, heat the oil bath to 97.5°C, continue reacting for 3 h, then add 1.5 kg of microcapsule repair agent and 550 g of microcapsule curing agent, stir at 22.5°C and 850 r / min for 1.5 h, add 26.5 g of sodium dodecylbenzene sulfonate and 55 mL of polyethylene glycol with a molecular weight of 600 into the reactor, continue stirring for 3.5 h, centrifuge at 3750 r / min for 5.5 min, discard the supernatant, wash the product twice with deionized water and anhydrous ethanol respectively, and dry it in vacuum at 70°C for 1.5 h to obtain a high temperature resistant coating of thermally responsive two-component microcapsules with a particle size of 50 μm.

[0045] S6: PVC resin, methyl tin stabilizer and zinc stearate were mixed evenly in a mass ratio of 70:2:2.5, and then mixed and plasticized at 185°C for 11 minutes using a two-roll open mill. The obtained sheet was pressed and formed using a four-roll calender at 185°C, cooled naturally to 42.5°C, and the high temperature resistant coating of the thermal responsive two-component microcapsule was coated at 250 mL / m 2 The amount of the coating is sprayed on the formed material, dried at 42.5°C for 65 minutes, cooled and rolled up to obtain a high temperature resistant coating and a PVC ordinary transparent film containing the coating.

[0046] Embodiment 3: A production process of a PVC transparent film containing a high temperature resistant coating, comprising the following steps:

[0047] S1: 4 kg of polystyrene microspheres with a particle size of 20-30 μm and 6 L of deionized water were added into a reactor, stirred at 25 ° C and 600 r / min for 3 h, then 600 mL of tetraethyl orthosilicate, 900 mL of anhydrous ethanol and 900 mL of 60% ammonia water were added, stirred at 45 ° C and 600 r / min for 14 h, filtered, and the filter cake was washed with deionized water and anhydrous ethanol for 3 times respectively, vacuum dried at 80 ° C for 2 h, transferred to a muffle furnace, and calcined at 800 ° C for 14 h under argon atmosphere to obtain silica / carbon microspheres.

[0048] S2: 2 kg of phenolic resin, 800 mL of acetylacetone, 320 mL of polyoxyethylene-polyoxypropylene copolymer as a macropore directing agent and 6 L of 30% ethanol solution were added into the reactor, stirred at 25 ° C and 600 r / min for 30 min, then 3 kg of silica / carbon microspheres were added, sealed, immersed at 65 ° C and 600 r / min for 14 h, filtered, and the filter cake was washed with deionized water and anhydrous ethanol for 3 times respectively, vacuum dried at 80 ° C for 2 h, heated to 110 ° C for curing for 26 h, heated to 360 ° C in an argon atmosphere, kept warm for 3 h, heated to 920 ° C at a rate of 6 ° C / min, kept warm for 3 h, and the product was washed 3 times with a 6% hydrofluoric acid solution to obtain hollow macroporous carbon microspheres with a pore size of 250-300 nm.

[0049] S3: Add 6 kg of hollow macroporous carbon microspheres, 90 g of sodium dodecylbenzene sulfonate, 60 mL of polyethylene glycol with a molecular weight of 700 and 5 L of deionized water into a reactor, ultrasonically disperse for 60 min, stir for 6 h at 25 °C and 500 r / min, filter, wash the filter cake with deionized water and anhydrous ethanol for 3 times respectively, and vacuum dry at 80 °C for 2 h to obtain dispersed hollow macroporous carbon microspheres; add 1.2 kg of dispersed hollow macroporous carbon microspheres, 600 g of epoxy resin and 5 L of acetone into a reactor, ultrasonically disperse for 60 min, seal, immerse for 40 min at 25 °C and 600 r / min, heat to 80 °C and continue stirring for 2 h, remove acetone, and obtain a microcapsule repair agent.

[0050] S4: 1.2 kg of dispersed hollow macroporous carbon microspheres, 4 L of anhydrous ethanol and 500 g of 2-methylimidazole were added to the reactor, ultrasonically dispersed for 60 min, sealed, immersed for 40 min at 25 ° C and 600 r / min, heated to 80 ° C, continued stirring for 2 h, removed anhydrous ethanol, and obtained a microcapsule curing agent.

[0051] S5: Add 4kg of 1-butyl-3-methylimidazole chloride into the reactor, stir and melt at 80°C and 600r / min, then add 2kg of cellulose microcrystals under nitrogen atmosphere, continue stirring for 2h, then add 900mL of ε-caprolactone and 35g of catalyst stannous octoate, heat the oil bath to 100°C, continue reacting for 4h, then add 2kg of microcapsule repair agent and 600g of microcapsule curing agent, stir at 25°C and 900r / min for 2h, add 28g of sodium dodecylbenzene sulfonate and 60mL of polyethylene glycol with a molecular weight of 700 into the reactor, continue stirring for 4h, centrifuge at 4000r / min for 6min, discard the supernatant, wash the product with deionized water and anhydrous ethanol three times respectively, and dry it in vacuum at 80°C for 2h to obtain a high temperature resistant coating of thermally responsive two-component microcapsules with a particle size of 60μm.

[0052] S6: PVC resin, methyl tin stabilizer and zinc stearate were mixed evenly in a mass ratio of 80:3:3, and then mixed and plasticized at 190°C for 12 minutes using a two-roll open mill. The obtained sheet was pressed and formed using a four-roll calender at 190°C, cooled naturally to 45°C, and the high temperature resistant coating of the thermal responsive two-component microcapsule was coated at 300mL / m 2 The amount of the coating is sprayed on the formed material, dried at 45°C for 80 minutes, cooled and rolled up to obtain a high temperature resistant coating and a PVC ordinary transparent film containing the coating.

[0053] Comparative Example 1: Based on Example 3, the hollow macroporous carbon microspheres in step S3 are replaced with commercially available hollow mesoporous carbon spheres of equal quality, and the remaining steps remain unchanged to prepare a high temperature resistant coating and a PVC normal transparent film containing the coating.

[0054] Comparative Example 2: Based on Example 3, the microcapsule curing agent in step S5 is replaced with 2-methylimidazole of equal mass in step S4, and the other steps remain unchanged to prepare a high temperature resistant coating and a PVC ordinary transparent film containing the coating.

[0055] Comparative Example 3: Based on Example 3, the cellulose microcrystals in step S5 are discarded, and the other steps remain unchanged to prepare a high temperature resistant coating and a PVC normal transparent film containing the coating.

[0056] In the embodiments and comparative examples:

[0057] Polystyrene microspheres were purchased from Beijing Zhongke Keyou Technology Co., Ltd.

[0058] Polyoxyethylene-polyoxypropylene copolymer was purchased from Yisheng Biotechnology Shanghai Co., Ltd.

[0059] Hollow mesoporous carbon spheres (CAS number: 1333-86-4) were purchased from Hangzhou Jikang New Materials Co., Ltd.

[0060] 1-Butyl-3-methylimidazole chloride was purchased from Wuhan Lanabai Pharmaceutical Chemical Co., Ltd.

[0061] The performance of the PVC ordinary transparent films containing high temperature resistant coatings prepared in Examples 1 to 3 and Comparative Examples 1 to 3 was tested.

[0062] 1. Adhesion test: Refer to the ASTM D3359 standard to measure the adhesion of the coating to the PVC plain film.

[0063] 2. Mechanical properties test: Refer to GB / T1040-2006 standard to test and measure the tensile strength and elongation at break of PVC normal transparent film to evaluate the overall strength of PVC normal transparent film.

[0064] 3. Heat sealing performance: A heat sealer was used to heat seal for 0.4s at 100°C and a pressure of 0.2MPa to observe the heat sealing fastness and knife sticking between the coating and the PVC ordinary transparent film to evaluate the thermal stability of the coating; the results are shown in Table 1:

[0065] Table 1 Performance test table of PVC ordinary transparent films with high temperature resistant coatings

[0066]

[0067]

[0068] It can be seen from Table 1 that the adhesion, mechanical properties, heat sealing firmness and knife sticking of the PVC ordinary transparent film prepared in Examples 1 to 3 are significantly better than those of the comparative example, indicating that the PVC ordinary transparent film prepared by the present invention has good heat resistance, high overall strength, close bonding with the substrate and is not easy to peel off.

[0069] In Comparative Example 1, the hollow macroporous carbon microspheres were replaced with hollow mesoporous carbon spheres. Silica was deposited on the surface of polystyrene microspheres, and then silica was used as a sacrificial template for the macropores. Non-ionic surfactant polyoxyethylene-polyoxypropylene copolymer was used as a mesopore directing agent, and phenolic resin was used as a carbon source to obtain hollow macroporous carbon microspheres with a pore size of 250-300nm. These microspheres were replaced with hollow mesoporous carbon spheres, which resulted in the epoxy resin repair agent and curing agent 2-methylimidazole being unable to effectively enter the pores and thus being unable to function effectively.

[0070] In Comparative Example 2, the microcapsule curing agent is replaced with 2-methylimidazole. 2-methylimidazole is dispersed in the coating only in the form of physical mixing, and no chemical bonding is formed. During long-term use, migration will occur and migrate to the surface of the coating to form crystals or precipitates, resulting in defects such as white spots and atomization on the surface, thereby affecting the life and use effect of the coating.

[0071] In Comparative Example 3, cellulose microcrystals are discarded and polycaprolactone is grafted with cellulose. Cellulose is a natural polymer material with abundant hydroxyl functional groups, which can form a strong interface bond with the PVC matrix through chemical or physical action, thereby avoiding shedding of the coating.

[0072] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0073] While the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that many changes, modifications, substitutions and variations can be made to the embodiments without departing from the principles and spirit of the invention.

Claims

1. A high temperature resistant coating, characterized in that: Prepared by the following steps: Add 1-butyl-3-methylimidazole chloride to the reactor, stir and melt, then add cellulose microcrystals under a nitrogen atmosphere, continue stirring for 1-2 hours, then add ε-caprolactone and stannous octoate, heat in an oil bath, continue to react for 2-4 hours, then add microcapsule repair agent and microcapsule curing agent, continue stirring for 1-2 hours, add sodium dodecylbenzene sulfonate and polyethylene glycol to the reactor, continue stirring for 3-4 hours, centrifuge, discard the supernatant, wash, and vacuum dry to obtain a high temperature resistant coating.

2. A high temperature resistant coating according to claim 1, characterized in that: The dosage ratio of the 1-butyl-3-methylimidazole chloride, cellulose microcrystals, ε-caprolactone, stannous octoate, microcapsule repair agent, microcapsule curing agent, sodium dodecylbenzene sulfonate and polyethylene glycol is 3-4kg: 1-2kg: 800-900mL: 30-35g: 1-2kg: 500-600g: 25-28g: 50-60mL.

3. A high temperature resistant coating according to claim 1, characterized in that: The microcapsule repair agent is prepared by the following steps: Hollow macroporous carbon microspheres, sodium dodecylbenzene sulfonate, polyethylene glycol and deionized water are added into a reactor, ultrasonically dispersed for 40-60 minutes, stirred at 20-25°C and 400-500r / min for 5-6 hours, filtered, and the filter cake is washed with deionized water and anhydrous ethanol for 2-3 times respectively, and vacuum dried to obtain dispersed hollow macroporous carbon microspheres; dispersed hollow macroporous carbon microspheres, epoxy resin and acetone are added into a reactor, ultrasonically dispersed for 40-60 minutes, sealed, immersed at 20-25°C and 500-600r / min for 30-40 minutes, heated to 70-80°C and stirred for 1-2 hours, and acetone is removed to obtain a microcapsule repair agent.

4. A high temperature resistant coating according to claim 3, characterized in that: The usage ratio of the hollow macroporous carbon microspheres, sodium dodecylbenzene sulfonate, polyethylene glycol and deionized water is 5-6kg:80-90g:50-60mL:4-5L; the usage ratio of the dispersed hollow macroporous carbon microspheres, epoxy resin and acetone is 1-1.2kg:500-600g:4-5L.

5. A high temperature resistant coating according to claim 1, characterized in that: The microcapsule curing agent is prepared by the following steps: Add dispersed hollow macroporous carbon microspheres, anhydrous ethanol and 2-methylimidazole into a reaction kettle, perform ultrasonic dispersion for 40-60 minutes, seal, immerse for 30-40 minutes at 20-25°C and 500-600 r / min, heat to 70-80°C and continue stirring for 1-2 hours, remove anhydrous ethanol, and obtain a microcapsule curing agent; The usage ratio of the dispersed hollow macroporous carbon microspheres, anhydrous ethanol and 2-methylimidazole is 1-1.2 kg: 3-4 L: 400-500 g.

6. A high temperature resistant coating according to claim 3, characterized in that: The hollow macroporous carbon microspheres are prepared by the following steps: Phenolic resin, acetylacetone, polyoxyethylene polyoxypropylene copolymer and 20-30wt% ethanol solution are added to a reaction kettle, stirred at 20-25°C and 500-600r / min for 20-30min, then silicon dioxide / carbon microspheres are added, sealed, immersed at 50-65°C and 500-600r / min for 12-14h, filtered, the filter cake is washed 2-3 times with deionized water and anhydrous ethanol respectively, vacuum dried, heated to 100-110°C and cured for 24-26h, heated to 350-360°C in an argon atmosphere, kept warm for 2-3h, heated to 900-920°C at a rate of 5-6°C / min, kept warm for 2-3h, and the product is washed 2-3 times with 5-6wt% hydrofluoric acid solution to obtain hollow macroporous carbon microspheres with a pore size of 250-300nm.

7. A high temperature resistant coating according to claim 6, characterized in that: The usage ratio of the phenolic resin, acetylacetone, polyoxyethylene-polyoxypropylene copolymer, ethanol solution and silicon dioxide / carbon microspheres is 1-2kg: 700-800mL: 300-320mL: 4-6L: 2-3kg.

8. A high temperature resistant coating according to claim 6, characterized in that: The silicon dioxide / carbon microspheres are prepared by the following steps: Add polystyrene microspheres with a particle size of 20-30 μm and deionized water into a reaction kettle, stir at 20-25° C. and 500-600 r / min for 2-3 hours, then add tetraethyl orthosilicate, anhydrous ethanol and 50-60wt% ammonia water, stir at 40-45° C. and 500-600 r / min for 12-14 hours, filter, wash the filter cake with deionized water and anhydrous ethanol for 2-3 times respectively, vacuum dry, transfer to a muffle furnace, and calcine at 750-800° C. for 12-14 hours under an argon atmosphere to obtain silicon dioxide / carbon microspheres; The usage ratio of the polystyrene microspheres, deionized water, tetraethyl orthosilicate, anhydrous ethanol and ammonia water is 3-4kg: 5-6L: 500-600mL: 800-900mL: 850-900mL.

9. A PVC transparent film containing a high temperature resistant coating, characterized in that: Contains a high temperature resistant coating as described in any one of claims 1 to 8.

10. The production process of a PVC normal transparent film with a high temperature resistant coating according to claim 9, characterized in that: The steps include: The PVC resin, methyl tin stabilizer and zinc stearate were mixed evenly in a mass ratio of 60-80:1-3:2-3, and then mixed and plasticized for 10-12 minutes at 180-190°C using a double-roll open mill. The obtained sheet was pressed and formed using a four-roll calender at 180-190°C, cooled naturally to 40-45°C, and the high temperature resistant coating was coated at 200-300mL / m 2 The amount of the coating agent is sprayed on the formed material, dried at 40-45°C for 50-80 minutes, cooled and rolled up to obtain a PVC ordinary transparent film with a high temperature resistant coating.

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