A heat-insulating and ultraviolet-resistant polyester film for automobiles and a preparation method thereof

Abstract

The application discloses an automobile heat-insulating anti-ultraviolet polyester film and a preparation method thereof, and belongs to the technical field of automobile films, and is used for solving the problems of the decline of the mechanical properties of the prepared polyester film and the technical problem of how to improve the heat-insulating property of the prepared polyester when the characteristic master batch with the organic ultraviolet absorber is added to improve the ultraviolet resistance of the polyester in the prior art. The preparation method of the automobile heat-insulating anti-ultraviolet polyester film comprises the following steps: an anti-ultraviolet adhesive is coated on one side of a modified PET film and one side of a fluororesin layer in sequence, and a first adhesive surface and a second adhesive surface are obtained; and the first adhesive surface and the second adhesive surface are laminated and hot-pressed and cured to obtain the automobile heat-insulating anti-ultraviolet polyester film. The modified PET film, the fluororesin layer and the anti-ultraviolet adhesive are prepared, the prepared polyester film has excellent mechanical properties, and the ultraviolet resistance and the heat-insulating property of the prepared polyester film are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of automobile film, and particularly relates to a heat-insulating and ultraviolet-proof polyester film for automobiles and a preparation method thereof. BACKGROUND

[0002] As a commonly used semi-crystalline thermoplastic material, the polyester (polyethylene terephthalate) film is a high molecular compound generated by polycondensation of terephthalic acid and ethylene glycol. The polyester film has good mechanical properties, gas barrier properties and good optical properties, and can be directly used as a packaging material for food and medicine. In recent years, with the large use of fluorocarbons, the ozone layer is damaged, the amount of ultraviolet radiation reaching the earth's surface is increased, and the problem of film ultraviolet aging is increasingly prominent. Therefore, the development of the polyester film with heat insulation and ultraviolet-proof properties can not only improve the service life of the film, but also improve the comprehensive performance of the film and the protection of the packaging contents.

[0003] Patent application CN104015452A discloses an ultraviolet-resistant automobile film, which comprises a metallized polyester film, an ultraviolet-resistant anti-dazzle coating, a dyed polyester film and the like. The metallized polyester film has a heat insulation effect; the dyed polyester film is sprayed with a pigment added with an ultraviolet absorber, a photosensitizer and a sensitizer. However, the above-mentioned prior art does not disclose the specific components and synthesis process of each film layer and functional additive.

[0004] CN105924905A discloses a polyester film; in the preparation of the above-mentioned polyester film, a characteristic master batch with an organic ultraviolet absorber is added, so that the polyester film has strong ultraviolet absorption capacity; however, the addition of the characteristic master batch in the polyester film will cause the mechanical properties of the prepared polyester film to decrease; in addition, how to improve the heat insulation performance of the automobile polyester film is also a technical problem to be solved.

[0005] In view of the above technical defects, a solution is proposed. SUMMARY

[0006] The application aims to provide a preparation method of a heat-insulating and ultraviolet-proof polyester film for automobiles, and aims to solve the technical problems that the addition of a characteristic master batch with an organic ultraviolet absorber to improve the ultraviolet resistance of the polyester will cause the mechanical properties of the prepared polyester film to decrease, and how to improve the heat insulation of the prepared polyester.

[0007] The object of the application can be achieved by the following technical scheme:

[0008] A preparation method of a heat-insulating and ultraviolet-proof polyester film for automobiles, comprising the following steps:

[0009] S1, the modified PET film is used as the first substrate layer, and the fluororesin layer is used as the second substrate layer; the anti-ultraviolet adhesive is coated on one side of the first substrate layer and one side of the second substrate layer in sequence, and first and second adhesive surfaces are obtained, respectively;

[0010] S2, the first and second adhesive surfaces are overlapped to form a composite film layer; the composite film layer is hot-pressed and cured to prepare the automobile heat insulation and ultraviolet protection polyester film.

[0011] Further, in step S1, the preparation method of the modified PET film comprises the following steps:

[0012] According to parts by weight, 60-70 parts of polyethylene terephthalate and 10-20 parts of 4, 4'-diphenyl ether dicarboxylic acid are blended, and then melt extruded at 260-280 DEG C for 3-5 min to obtain the modified PET film.

[0013] Further, in step S1, the preparation method of the fluororesin layer comprises the following steps:

[0014] B1, four fluorinated ethylene and trifluorochloroethylene are introduced into a pressure reaction kettle, and then perfluorodimethylcyclobutane, perfluoroethyl vinyl ether, an initiator and a chain transfer agent are added into the pressure reaction kettle to obtain a reaction system; the pressure reaction kettle is heated, and then a polymerization reaction occurs; the pressure reaction kettle is cooled to room temperature, emptied, and the solvent is separated, and the solid polymer is taken out; the solid polymer is dried to obtain the prepared composite fluororesin;

[0015] The non-aqueous medium polymerization method is used to prepare the composite fluororesin, perfluorodimethylcyclobutane is used as a solvent, and perfluoroethyl vinyl ether, tetrafluoroethylene and trifluorochloroethylene are used as monomers to occur a polymerization reaction, and then the composite fluororesin with a block perfluoroalkyl, tetrafluoroethylene-trifluorochloroethylene structure is prepared.

[0016] B2, the composite fluororesin is melt extruded to obtain the fluororesin layer.

[0017] Further, in step B1, the amount ratio of tetrafluoroethylene, trifluorochloroethylene, perfluorodimethylcyclobutane, perfluoroethyl vinyl ether, an initiator and a chain transfer agent is 15-20 mL:10-20 mL:200-300 mL:20-30 mL:0.1-0.2 g:0.3-0.5 g; the polymerization reaction temperature is

[0018] 55-65 DEG C, the polymerization reaction pressure is 1.5-2.2 MPa, the polymerization reaction time is 60-100 min; the drying temperature is 95-100 DEG C, and the drying time is 20-30 min.

[0019] Further, in step B2, the temperature for melt extrusion of the composite fluororesin is 320-340℃, and the melt extrusion time is 10-15 min.

[0020] Further, in step S1, the preparation method of the anti-ultraviolet adhesive comprises the following steps:

[0021] A1, titanium tetrachloride is added dropwise into deionized water at 0-5℃, and then zinc oxide is added and mixed to obtain a mixture; ammonia water is added dropwise into the mixture to adjust the pH value of the mixture to 9-10; hydrogen peroxide is added dropwise, and the mixture is aged at 22-25℃ for 20-24h to form a nano-titanium dioxide-zinc oxide hybrid sol;

[0022] Titanium dioxide sol is prepared by a solution-gel method using titanium tetrachloride as a titanium source, ammonia water as a pH regulator, and hydrogen peroxide as a complexing agent.

[0023] A2, ammonia gas is introduced into 3-chloropropylmethyldichlorosilane, and the mixture is reacted at 25-35℃ for 4-6h to obtain the synthesized aminated silane; ammonia gas is introduced again into the aminated silane at 55-65℃ to synthesize a polar coupling agent through polycondensation reaction;

[0024] The reaction formula for synthesizing the aminated silane by reacting 3-chloropropylmethyldichlorosilane with ammonia gas is as follows:

[0025]

[0026] The reaction formula for synthesizing the polar coupling agent by continuously polycondensing the aminated silane with ammonia gas is as follows:

[0027]

[0028] A3, the nano-titanium dioxide-zinc oxide hybrid sol, the water-based polyurethane, and the polar coupling agent are mixed and aged at 30-35℃ for 20-30min to form the anti-ultraviolet adhesive.

[0029] Further, in step A1, the concentration of the ammonia water is 0.1mol / L, and the concentration of the hydrogen peroxide is 60-70wt%; the amount ratio of titanium tetrachloride, deionized water, zinc oxide, and hydrogen peroxide is

[0030] 5-10mL:20-30mL:0.5-1.5g:5-8mL.

[0031] Further, in step A2, the amount ratio of 3-chloropropylmethyldichlorosilane, the introduced ammonia gas, and the introduced ammonia gas again is 10-20mL:100-300mL:150-500mL; in step A3, the weight ratio of the nano-titanium dioxide-zinc oxide hybrid sol, the water-based polyurethane, and the polar coupling agent is 10-20:5-10:3-10.

[0032] Further, in step S1, the anti-ultraviolet adhesive is coated on the first substrate layer and the second substrate layer with a thickness of 1-2 mm; in step S2, the temperature of the heat pressing and curing is 65-85 DEG C, the pressure of the heat pressing and curing is 0.3-0.5 MPa, and the time of the heat pressing and curing is 20-30 min.

[0033] As another aspect of the present application, the automobile heat insulation anti-ultraviolet polyester film is prepared by the preparation method of the automobile heat insulation anti-ultraviolet polyester film.

[0034] The present application has the following advantages:

[0035] 1, the polyester film prepared by the present application is obtained by compounding a first substrate layer and a second substrate layer, anti-ultraviolet adhesive is coated on one side of the first substrate layer and one side of the second substrate layer in turn, and then heat pressing and curing process is carried out, and then the automobile heat insulation anti-ultraviolet polyester film is prepared. The second substrate layer is obtained by compounding fluororesin melt extrusion; the synthesized composite fluororesin contains block structure perfluoroalkyl, tetrafluoroethylene-trifluorochloroethylene, using trifluorochloroethylene, perfluorodimethylcyclobutane and perfluoroethyl vinyl ether as reaction monomer. The C-F bond in the structure of the composite fluororesin has very high bond energy and almost does not absorb ultraviolet rays, so it has strong anti-ultraviolet performance. The present application synthesizes multi-block fluororesin and selects chain transfer agent methanol, and then reduces the melt viscosity of the synthesized composite fluororesin, and the composite fluororesin is easy to injection molding and has narrower chain length distribution. The present application uses 4,4'-diphenyl ether dicarboxylic acid modified polyethylene terephthalate, and then melt extrusion is carried out to prepare modified PET film. The introduction of 4,4'-diphenyl ether dicarboxylic acid in the thermoplastic resin polyethylene terephthalate can improve the chemical resistance and polarity of the prepared modified PET film, and then improve the compatibility of the first substrate layer, the second substrate layer and the coated anti-ultraviolet adhesive, and improve the mechanical properties and mechanical properties of the synthesized polyester film as a whole.

[0036] 2, The anti-ultraviolet adhesive prepared by the application is composed of nano-titanium dioxide-zinc oxide hybrid sol, polar coupling agent and water-based polyurethane. When preparing the nano-titanium dioxide-zinc oxide hybrid sol, titanium tetrachloride is used as a titanium source to prepare nano-titanium dioxide sol; before adding ammonia and hydrogen peroxide, zinc oxide particles are added in advance to form a nano-titanium dioxide-zinc oxide blended hybrid sol; the nano-titanium dioxide sol and the zinc oxide sol both have strong ultraviolet resistance and heat insulation performance. 3-chloropropylmethyldichlorosilane is pre-reacted with ammonia to obtain aminated silane with multiple amino groups; the aminated silane is continuously reacted with ammonia, and the condensate thereof is the prepared polar coupling agent. The silane in the polar coupling agent can be hydrolyzed by the water-based polyurethane; the hydroxyl groups on the surface of the nano-titanium dioxide-zinc oxide hybrid sol have good compatibility with the polar coupling agent, so that the adhesion of the anti-ultraviolet adhesive prepared by the application is further enhanced; the anti-ultraviolet adhesive with nano inorganic particles is coated between two substrate layers to form a heat insulation and ultraviolet resistant polyester film for automobiles, which has good heat insulation performance. DETAILED DESCRIPTION

[0037] The technical solutions of the application will be described clearly and completely below with reference to the embodiments. Obviously, the described embodiments are only some of the embodiments of the application, but not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0038] The zinc oxide used in the embodiments 4-6 is purchased from Henan Yaojin Chemical Co., Ltd., and the particle size is 100-200 mesh; the water-based polyurethane used in the embodiments 4-6 is purchased from Jinan Anying Trading Co., Ltd., and the content of the water-based polyurethane is 50wt%.

[0039] Embodiment 1

[0040] The embodiment provides a preparation method of a fluororesin layer of a heat insulation and ultraviolet resistant polyester film for automobiles, which comprises the following steps:

[0041] B1, select 500 mL, with magnetic drive stirring pressure reaction kettle, into the pressure reaction kettle 15 mL of tetrafluoroethylene and 10 mL of chlorotrifluoroethylene, then add 200 mL of perfluorodimethylcyclobutane, 20 mL of perfluoroethyl vinyl ether, 0.1 g of initiator azobisisobutyronitrile and 0.3 g of chain transfer agent methanol to the reaction kettle, to obtain the reaction system. The pressure reaction kettle is closed, and then the pressure reaction kettle is heated to 55 DEG C, and then the stirring is started, and the polymerization reaction occurs at 300 r / min; the polymerization reaction pressure is set to 1.5 MPa, and the polymerization reaction time is 60 min, which is regarded as the end of the polymerization reaction. Then cool the pressure reaction kettle to room temperature, vent, separate the solvent, and take out the solid polymer; the solid polymer is dried at 95 DEG C for 20 min, which is the prepared composite fluororesin.

[0042] B2, the composite fluororesin is added to the twin screw extruder for melt extrusion, the melt extrusion temperature is 320 DEG C, and the melt extrusion time is 10 min, to prepare the fluororesin layer.

[0043] Example 2

[0044] The embodiment provides a preparation method of a fluororesin layer for a heat insulation and ultraviolet resistant polyester film for a car, comprising the following steps:

[0045] B1, select 500 mL, with magnetic drive stirring pressure reaction kettle, into the pressure reaction kettle 15 mL of tetrafluoroethylene and 10 mL of chlorotrifluoroethylene, then add 200 mL of perfluorodimethylcyclobutane, 20 mL of perfluoroethyl vinyl ether, 0.1 g of initiator azobisisobutyronitrile and 0.3 g of chain transfer agent methanol to the reaction kettle, to obtain the reaction system. The pressure reaction kettle is closed, and then the pressure reaction kettle is heated to 55 DEG C, and then the stirring is started, and the polymerization reaction occurs at 300 r / min; the polymerization reaction pressure is set to 1.5 MPa, and the polymerization reaction time is 60 min, which is regarded as the end of the polymerization reaction. Then cool the pressure reaction kettle to room temperature, vent, separate the solvent, and take out the solid polymer; the solid polymer is dried at 95 DEG C for 20 min, which is the prepared composite fluororesin.

[0046] B2, the composite fluororesin is added to the twin screw extruder for melt extrusion, the melt extrusion temperature is 320 DEG C, and the melt extrusion time is 10 min, to prepare the fluororesin layer.

[0047] Example 3

[0048] The embodiment provides a preparation method of a fluororesin layer for a heat insulation and ultraviolet resistant polyester film for a car, comprising the following steps:

[0049] B1, select 500 mL, with magnetic drive stirring pressure reaction kettle, into the pressure reaction kettle 20 mL of tetrafluoroethylene and 20 mL of chlorotrifluoroethylene, then add 300 mL of perfluorodimethylcyclobutane, 30 mL of perfluoroethyl vinyl ether, 0.2 g of initiator azobisisobutyronitrile and 0.5 g of chain transfer agent methanol to the pressure reaction kettle, to obtain the reaction system. The pressure reaction kettle is closed, and then the pressure reaction kettle is heated to 65 DEG C, and then the stirring is started, and the polymerization reaction occurs at 600 r / min; the polymerization reaction pressure is set to 2.2 MPa, and the polymerization reaction occurs for 100 min, and then the polymerization reaction is considered to be completed. Then cool the pressure reaction kettle to room temperature, vent, then separate the solvent, and take out the solid polymer; the solid polymer is dried at 100 DEG C for 30 min, and the prepared composite fluororesin is obtained.

[0050] B2, the composite fluororesin is added to the twin-screw extruder for melt extrusion, the temperature of melt extrusion is 340 DEG C, and the time of melt extrusion is 15 min, to obtain the fluororesin layer.

[0051] Example 4

[0052] The embodiment provides a preparation method of an anti-ultraviolet adhesive for a heat-insulating and ultraviolet-resistant polyester film for automobiles, comprising the following steps:

[0053] A1, measure 20 mL of deionized water into a beaker, then transfer the beaker to a water bath for cold water bath, and the temperature of the cold water bath is 5 DEG C. Then slowly add 5 mL of titanium tetrachloride to the beaker, and the total time of dropping is controlled within 3 min, then stand for 15 min to form a clear and transparent solution; then add 0.5 g of zinc oxide to the beaker and mix uniformly to obtain a mixture. Add 0.1 mol / L of ammonia water to the above-mentioned mixture until the pH value of the mixture is 9; then add 5 mL of 60 wt% hydrogen peroxide, and age at 22 DEG C for 24 h to form a nano titanium dioxide-zinc oxide hybrid sol.

[0054] A2, 10 mL of 3-chloropropylmethyldichlorosilane is added to a 150 mL three-necked flask, then ammonia gas is introduced into the three-necked flask, the flow rate of the introduced ammonia gas is 5 mL / min, and the amount of the introduced ammonia gas is 100 mL; then the three-necked flask is closed, and the reaction is carried out at 25 DEG C for 4 h, and the liquid is collected, which is the synthesized aminated silane. Heat the above-mentioned three-necked flask to 55 DEG C, then introduce ammonia gas into the three-necked flask again for polycondensation, the flow rate of the introduced ammonia gas is 5 mL / min, the amount of the introduced ammonia gas is 150 mL, and the total time of the polycondensation reaction is 2 h, finally the polar coupling agent is synthesized.

[0055] A3, according to weight parts, mix 10 parts of the nano titanium dioxide-zinc oxide hybrid sol, 5 parts of the water-based polyurethane and 3 parts of the polar coupling agent uniformly, and stand at 30 DEG C for 20 min to form the anti-ultraviolet adhesive.

[0056] Example 5

[0057] The embodiment provides a preparation method of an anti-ultraviolet adhesive of a heat-insulating ultraviolet-proof polyester film for an automobile.

[0058] A1, 25 mL of deionized water is weighed and transferred into a beaker, and then the beaker is transferred into a water bath kettle for cold water bath, and the temperature of the cold water bath is 2 ℃. Then 8 mL of titanium tetrachloride is slowly added into the beaker, the total time of dropping is controlled to be 4 min, and then the beaker is placed for 20 min to form a clear and transparent solution. Then 1 g of zinc oxide is added into the beaker, and the mixture is uniformly mixed to obtain a mixture. 0.1 mol / L of ammonia water is added into the mixture drop by drop until the pH value of the mixture is 9.5. Then 7 mL of 65 wt% hydrogen peroxide is added, and the nanometer titanium dioxide-zinc oxide hybrid sol is formed after aging at 23 ℃ for 22 h.

[0059] A2, 13 mL of 3-chloropropylmethyldichlorosilane is added into a three-necked flask, then ammonia gas is introduced into the three-necked flask, the flow rate of the ammonia gas is 6 mL / min, and the amount of the ammonia gas is 200 mL. Then the three-necked flask is closed, and the reaction is carried out at 30 ℃ for 5 h, and the liquid is collected, which is the synthesized aminated silane. The three-necked flask is heated to 60 ℃, then ammonia gas is introduced into the three-necked flask again for polycondensation reaction, the flow rate of the ammonia gas is 8 mL / min, the amount of the ammonia gas is 300 mL, and the total time of the polycondensation reaction is 3 h, and finally the polar coupling agent is synthesized.

[0060] A3, according to weight parts, 15 parts of the nanometer titanium dioxide-zinc oxide hybrid sol material, 8 parts of the water-based polyurethane and 6 parts of the polar coupling agent are uniformly mixed and placed at 32 ℃ for 22 min to form the anti-ultraviolet adhesive.

[0061] Example 6

[0062] The embodiment provides a preparation method of an anti-ultraviolet adhesive of a heat-insulating ultraviolet-proof polyester film for an automobile.

[0063] A1, 25 mL of deionized water is weighed and transferred into a beaker, and then the beaker is transferred into a water bath kettle for cold water bath, and the temperature of the cold water bath is 2 ℃. Then 8 mL of titanium tetrachloride is slowly added into the beaker, the total time of dropping is controlled to be 4 min, and then the beaker is placed for 20 min to form a clear and transparent solution. Then 1 g of zinc oxide is added into the beaker, and the mixture is uniformly mixed to obtain a mixture. 0.1 mol / L of ammonia water is added into the mixture drop by drop until the pH value of the mixture is 9.5; then 7 mL of 65 wt% hydrogen peroxide is added, and the nanometer titanium dioxide-zinc oxide hybrid sol is formed after aging at 23 ℃ for 22 h.

[0064] A2, 20 mL of 3-chloropropylmethyldichlorosilane is added into a 150 mL three-necked flask, then ammonia gas is introduced into the three-necked flask, the flow rate of the introduced ammonia gas is 10 mL / min, and the amount of the introduced ammonia gas is 300 mL; then the three-necked flask is closed, and reaction is carried out at 35℃ for 6 h, and the liquid is collected, which is the synthesized aminosilane. The above three-necked flask is heated to 65℃, then ammonia gas is introduced into the three-necked flask again for polycondensation reaction, the flow rate of the introduced ammonia gas is 10 mL / min, the amount of the introduced ammonia gas is 500 mL, and the total time of the polycondensation reaction is 4 h, and finally the polar coupling agent is synthesized.

[0065] A3, 20 parts of nanometer titanium dioxide-zinc oxide hybrid sol material, 10 parts of water-based polyurethane and 10 parts of the polar coupling agent are uniformly mixed, and are placed at 35℃ for 30 min to form the anti-ultraviolet adhesive.

[0066] Example 7

[0067] The embodiment provides a preparation method of a heat-insulating and anti-ultraviolet polyester film for automobiles, and the method comprises the following steps:

[0068] S1, 60 parts of polyethylene terephthalate and 10 parts of 4,4'-diphenyl ether dicarboxylic acid are blended and melt-extruded at 260℃ for 5 min to obtain a modified PET film.

[0069] S2, the modified PET film is cut into a size of 20 cm*20 cm to obtain a first base material layer; the fluororesin layer prepared in Example 1 is cut into a size of 20 cm*20 cm to obtain a second base material layer. The anti-ultraviolet adhesive prepared in Example 4 is coated on one side of the first base material layer and one side of the second base material layer in sequence, and the coating thickness of the two sides of the first base material layer and the second base material layer is 1 mm, and the coating surfaces are marked as a first adhesive surface and a second adhesive surface respectively.

[0070] S3, the first adhesive surface and the second adhesive surface are overlapped to obtain a composite film layer. The composite film layer is heat-pressed and cured at a temperature of 65℃, a pressure of 0.3 MPa and for a time of 20 min to obtain the heat-insulating and anti-ultraviolet polyester film for automobiles.

[0071] Example 8

[0072] The embodiment provides a preparation method of a heat-insulating and anti-ultraviolet polyester film for automobiles, and the method comprises the following steps:

[0073] S1, 66 parts of polyethylene terephthalate and 15 parts of 4,4'-diphenyl ether dicarboxylic acid are blended and melt-extruded at 270℃ for 4 min to obtain a modified PET film.

[0074] S2, the modified PET film is cut into a size of 22 cm x 22 cm to obtain a first substrate layer; the fluororesin layer prepared in Example 2 is cut into a size of 22 cm x 22 cm to obtain a second substrate layer. The anti-ultraviolet adhesive prepared in Example 5 is coated on one side of the first substrate layer and one side of the second substrate layer in sequence, and the coating thickness on both sides of the first substrate layer and the second substrate layer is 1.5 mm, and the coating surfaces are marked as a first adhesive surface and a second adhesive surface, respectively.

[0075] S3, the first adhesive surface and the second adhesive surface are overlapped to obtain a composite film layer. The composite film layer is hot-pressed and cured, the temperature of hot-pressing and curing is 75℃, the pressure of hot-pressing and curing is 0.4 MPa, and the time of hot-pressing and curing is 25 min, to obtain an automobile heat insulation and ultraviolet resistant polyester film.

[0076] Example 9

[0077] The embodiment provides a preparation method of an automobile heat insulation and ultraviolet resistant polyester film, comprising the following steps:

[0078] S1, 70 parts of polyethylene terephthalate and 20 parts of 4,4'-diphenyl ether dicarboxylic acid are blended and melt-extruded at 280℃ for 3 min to obtain a modified PET film.

[0079] S2, the modified PET film is cut into a size of 25 cm x 25 cm to obtain a first substrate layer; the fluororesin layer prepared in Example 3 is cut into a size of 25 cm x 25 cm to obtain a second substrate layer. The anti-ultraviolet adhesive prepared in Example 6 is coated on one side of the first substrate layer and one side of the second substrate layer in sequence, and the coating thickness on both sides of the first substrate layer and the second substrate layer is 2 mm, and the coating surfaces are marked as a first adhesive surface and a second adhesive surface, respectively.

[0080] S3, the first adhesive surface and the second adhesive surface are overlapped to obtain a composite film layer. The composite film layer is hot-pressed and cured, the temperature of hot-pressing and curing is 85℃, the pressure of hot-pressing and curing is 0.5 MPa, and the time of hot-pressing and curing is 30 min, to obtain an automobile heat insulation and ultraviolet resistant polyester film.

[0081] Comparative Example 1

[0082] The difference between the comparative example and Example 9 is that 40 mL of tetrafluoroethylene is used instead of 20 mL of tetrafluoroethylene and 20 mL of chlorotrifluoroethylene when preparing the composite fluororesin.

[0083] Comparative Example 2

[0084] The difference between the comparative example and Example 9 is that the method for preparing the nano-titanium dioxide-zinc oxide hybrid sol is different, which comprises the following steps:

[0085] 30 mL of deionized water was measured into a beaker, and then the beaker was transferred to a water bath for cold water bath, the temperature of the cold water bath was 0 ℃; 10 mL of titanium tetrachloride was slowly added into the beaker, the total time of the dropwise addition was controlled within 5 min, and a clear transparent solution was formed; 0.1 mol / L of ammonia water was added into the above clear transparent solution until the pH value of the mixture was 10; 8 mL of 70 wt% hydrogen peroxide was added, and the aging was carried out at 25 ℃ for 20 h to obtain an aging product. 1.5 g of zinc oxide was added into the aging product, and the mixture was uniformly mixed to obtain the prepared nano titanium dioxide-zinc oxide hybrid sol.

[0086] Comparative Example 3

[0087] The difference between the present comparative example and Example 9 is that the same mass of aminosilane is used to replace the prepared polar coupling agent in step A2 when preparing the anti-ultraviolet adhesive.

[0088] Comparative Example 4

[0089] The difference between the present comparative example and Example 9 is that the same mass of polyethylene terephthalate is used to replace the prepared modified PET film.

[0090] Performance test:

[0091] 1. First, the automobile heat insulation and anti-ultraviolet polyester film prepared in Examples 7-9 and Comparative Examples 1-4 was cut into a 15 mm x 10 mm rectangular sample; according to GB / T 13022-91 “Plastic Film Tensile Property Test Method”, the mechanical properties were measured (in the transverse direction) by using an electronic universal material testing machine; the mechanical properties of the film were characterized by two parameters of elongation at break and tensile strength. Each group of samples was measured five times, and the average value was calculated.

[0092] 2. The automobile heat insulation and anti-ultraviolet polyester film prepared in Examples 7-9 and Comparative Examples 1-4 was cut into a 5 cm x 5 cm sample in advance; then the sample was tested by using an ultraviolet-visible spectrophotometer. Air was used as the reference; through data analysis, the average ultraviolet transmittance of the sample at 325 nm-400 nm was detected in turn.

[0093] 3. The automobile heat insulation and anti-ultraviolet polyester film prepared in Examples 7-9 and Comparative Examples 1-4 was cut into a 5 cm x 5 cm sample in advance; based on the evaporation hot plate method, a thermal insulation tester was used to test the thermal resistance value of the sample. The specific test results are shown in Table 1:

[0094] Table 1. Performance test data of the sample

[0095]

[0096]

[0097] Data analysis: the automobile heat insulation and ultraviolet resistant polyester film prepared by the examples 7-9 of the present application all have excellent mechanical properties, which are represented by high tensile strength and elongation at break. In the comparative example 4, the polyethylene terephthalate is used to replace the modified PET film; the polarity of the modified PET film is higher, and the compatibility with the ultraviolet resistant adhesive and the second substrate layer is good, so that the overall mechanical properties of the automobile heat insulation and ultraviolet resistant polyester film prepared are better. Therefore, compared with the examples 7-9, the tensile strength and elongation at break of the polyester film prepared in the comparative example 4 are significantly reduced.

[0098] The automobile heat insulation and ultraviolet resistant polyester film prepared by the examples 7-9 of the present application all have excellent ultraviolet resistant properties, which are represented by low ultraviolet transmittance at 325-400 nm. However, in the comparative example 2, the zinc oxide is directly doped into the nano-titanium dioxide sol, and a uniform mixture of nano-titanium dioxide-zinc oxide sol is not formed. The two kinds of sol particles have a synergistic effect in absorbing and scattering ultraviolet light, so that the ultraviolet resistant properties of the polyester film prepared in the comparative example 2 are reduced, and the ultraviolet transmittance at a specific wavelength is increased.

[0099] The automobile heat insulation and ultraviolet resistant polyester film prepared by the examples 7-9 of the present application all have excellent heat insulation properties, which are represented by high thermal resistance. However, in the comparative example 1, the number of block monomers is reduced when the composite fluororesin is prepared; in the comparative example 4, the pure PET film is used to replace the modified PET film; both of which will reduce the polarity, compatibility and crosslinking degree of each component of the first substrate layer, the second substrate layer and the ultraviolet resistant adhesive, thereby reducing the heat insulation properties and thermal resistance of the prepared polyester film. In the comparative example 3, the uncondensed aminated silane is used to replace the synthesized polar coupling agent, which will reduce the heat insulation properties and thermal resistance of the automobile heat insulation and ultraviolet resistant polyester film prepared.

[0100] The above content is only an example and description of the structure of the present application, and those skilled in the art can make various modifications or supplements or use similar ways to replace the described specific embodiments, as long as they do not deviate from the structure of the present application or exceed the scope defined by the present claims, which shall belong to the protection scope of the present application.

[0101] In the description of the present specification, the description referring to the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are contained in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0102] The preferred embodiments of the application disclosed above are only to help explain the application. The preferred embodiments are not intended to limit the application to specific embodiments. Obviously, many modifications and variations are possible in light of the above teachings. The preferred embodiments are chosen and described in order to provide the best explanation of the principles and their applications. Those skilled in the art will understand and appreciate that the application is practiced with the claimed scope and equivalents thereof.

Claims

1. A method for preparing a heat-insulating and UV-protective polyester film for automobiles, characterized in that, The method comprises the following steps: S1, the modified PET film is used as a first substrate layer, and the fluororesin layer is used as a second substrate layer; the anti-ultraviolet adhesive is coated on one side of the first substrate layer and one side of the second substrate layer in sequence to obtain a first adhesive surface and a second adhesive surface respectively; S2, the first adhesive surface and the second adhesive surface are overlapped to form a composite film layer; the composite film layer is hot-pressed and cured to prepare the heat-insulating and ultraviolet-proof polyester film for automobiles; The preparation method of the modified PET film comprises the following steps: According to the weight parts, 60-70 parts of polyethylene terephthalate and 10-20 parts of 4,4'-diphenyl ether dicarboxylic acid are blended, and then melted and extruded at 260-280 DEG C for 3-5 min to obtain the modified PET film. The preparation method of the fluororesin layer comprises the following steps: B1, tetrafluoroethylene and trifluorochloroethylene are introduced into a pressure reactor, and then perfluorodimethylcyclobutane, perfluoroethyl vinyl ether, an initiator and a chain transfer agent are added into the pressure reactor to obtain a reaction system; the pressure reactor is heated, and then polymerization reaction occurs; the pressure reactor is cooled to room temperature, emptied, and the solvent is separated to obtain a solid polymer; the solid polymer is dried to obtain the prepared composite fluororesin; B2, the composite fluororesin is melted and extruded to obtain the fluororesin layer; The preparation method of the anti-ultraviolet adhesive comprises the following steps: A1, titanium tetrachloride is added dropwise into deionized water at 0-5 DEG C, and then zinc oxide is added and mixed to obtain a mixture; ammonia water is added dropwise into the mixture to adjust the pH value of the mixture to 9-10; hydrogen peroxide is added dropwise, and the mixture is aged at 22-25 DEG C for 20-24 h to form a nano-titanium dioxide-zinc oxide hybrid sol; A2, ammonia gas is introduced into 3-chloropropylmethyldichlorosilane to react at 25-35 DEG C for 4-6 h, and then the liquid is collected to obtain the synthesized ammoniated silane; the ammoniated silane is introduced into ammonia gas again to perform polycondensation reaction at 55-65 DEG C to synthesize a polar coupling agent; A3, the nano-titanium dioxide-zinc oxide hybrid sol, the water-based polyurethane and the polar coupling agent are mixed and uniformly stirred at 30-35 DEG C for 20-30 min to form the anti-ultraviolet adhesive.

2. The preparation method of the heat-insulating and ultraviolet-resistant polyester film for automobiles according to claim 1, characterized in that, In step B1, the amount ratio of tetrafluoroethylene, trifluorochloroethylene, perfluorodimethylcyclobutane, perfluoroethyl vinyl ether, the initiator and the chain transfer agent is 15-20 mL:10-20 mL:200-300 mL:20-30 mL:0.1-0.2 g:0.3-0.5 g; the temperature of the polymerization reaction is 55-65 DEG C, the pressure of the polymerization reaction is 1.5-2.2 MPa, and the time of the polymerization reaction is 60-100 min; the drying temperature is 95-100 DEG C, and the drying time is 20-30 min.

3. The preparation method of the heat-insulating and ultraviolet-resistant polyester film for automobiles according to claim 1, characterized in that, In step B2, the temperature of the melting and extrusion of the composite fluororesin is 320-340 DEG C, and the time of the melting and extrusion is 10-15 min.

4. The preparation method of the heat-insulating and ultraviolet-resistant polyester film for automobiles according to claim 1, characterized in that, In step A1, the concentration of the ammonia water is 0.1 mol / L, and the concentration of the hydrogen peroxide is 60-70 wt%; the amount ratio of titanium tetrachloride, deionized water, zinc oxide and hydrogen peroxide is 5-10 mL:20-30 mL:0.5-1.5 g:5-8 mL.

5. The method for preparing a heat-insulating and ultraviolet-resistant polyester film for a car according to claim 1, characterized in that, In step A2, the amount ratio of 3-chloropropylmethyldichlorosilane, ammonia and again ammonia is 10-20 mL:100-300 mL:150-500 mL; in step A3, the weight ratio of nano titanium dioxide-zinc oxide hybrid sol, aqueous polyurethane and polar coupling agent is 10-20:5-10:3-10.

6. The preparation method of the heat-insulating and ultraviolet-resistant polyester film for automobiles according to claim 1, characterized in that, In step S1, the coating thickness of the anti-ultraviolet adhesive on the first substrate layer and the second substrate layer is 1-2 mm; in step S2, the temperature of heat pressing and curing is 65-85 DEG C, the pressure of heat pressing and curing is 0.3-0.5 MPa, and the time of heat pressing and curing is 20-30 min.

7. A heat-insulating and anti-ultraviolet polyester film for automobile prepared by the preparation method of any one of claims 1-6.

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