Preparation method and application of heat-resistant halogen-free flame-retardant modified polycarbonate film

Abstract

The invention discloses a preparation method and application of a heat-resistant halogen-free flame-retardant modified polycarbonate film, and belongs to the technical field of polycarbonate films. Comprising the following raw materials in parts by weight: 80-97 parts of a polycarbonate raw material, 0.05-2 parts of a dispersing agent, 0.3-0.6 part of a sulfonate flame retardant, 0.5-2 parts of an organic silicon flame retardant, 0.2-0.5 part of an anti-dripping agent, 0.05-0.2 part of a dispersing agent, 0.1-1 part of a release agent, 0.05-1 part of an antioxidant and 1-4 parts of black masterbatch. Wherein the dispersing agent and the release agent can improve the processing stability and film forming; the antioxidant can play a synergistic role, so that the oxidation resistance of the film is improved; the black master batch ensures that the film product is lightproof; the organic silicon flame retardant can improve the heat resistance and mechanical property of the film, can play a synergistic role with the sulfonate flame retardant and the anti-dripping agent, enhances the flame retardant property of the film, is stable in performance and not prone to falling off, and has application value in the new energy battery and energy storage industry.

Description

Technical Field

[0001] The invention belongs to the technical field of polycarbonate films, and in particular relates to a preparation method and application of a heat-resistant halogen-free flame-retardant modified polycarbonate film. Background Art

[0002] The application areas of polycarbonate films in electronic products, new energy batteries and energy storage materials are constantly expanding. In these fields, since the use environment has high heat and is related to people's daily life and travel, in order to improve its safety performance, it is necessary to improve its flame retardant properties on the basis of its original performance. The use of halogen-based flame retardant modifiers to improve its flame retardancy can achieve excellent flame retardant properties, but there are great safety hazards to human health. The use of phosphorus-based flame retardants will reduce the temperature resistance of polycarbonate materials, limit some usage scenarios and have safety hazards.

[0003] CN116769292A discloses a halogen-free flame-retardant polycarbonate composition and its preparation method and application, and its specific components are: 42-93 parts of polycarbonate, 2-20 parts of ABS, 4-18 parts of flame retardant, 0.1-3 parts of hydrophobic agent, 1-15 parts of toughening agent, and 0.2-1 parts of anti-dripping agent. Although the thin-walled flame-retardant polycarbonate material provided by the technical solution can reach the UL-94 flame retardant V0 level at 1mm, it cannot reach the UL-94 flame retardant V0 level after 0.25mm-0.5mm film molding, resulting in safety risks at the application level, and its flame retardant performance still needs to be improved. In addition, with the continuous development of the electric vehicle industry, the requirements for new energy batteries are also constantly increasing. Polycarbonate films are often used as insulating protective films for new energy batteries. Therefore, it is also necessary to enhance the performance of polycarbonate films to meet their application in new energy batteries and energy storage industries. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a method for preparing a heat-resistant halogen-free flame-retardant modified polycarbonate film and its application.

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

[0006] A method for preparing a heat-resistant halogen-free flame-retardant modified polycarbonate film comprises the following steps:

[0007] A1. Drying the polycarbonate raw material, the sulfonate flame retardant, the silicone flame retardant and the anti-dripping agent;

[0008] A2, the polycarbonate raw material dried in step A1 is stirred in a high-speed mixer at a speed of 200-500 rpm for 3-8 minutes, and then a dispersant is added, and the stirring is continued for 1-4 minutes, and then added into a twin-screw extruder with a sulfonate flame retardant, a silicone flame retardant, and an anti-dripping agent, melt blended, extruded, and granulated to obtain a masterbatch;

[0009] A3. After drying the release agent and antioxidant, stir them in a high-speed mixer at a speed of 200-700 rpm for 3-5 minutes, and then melt-extrude them with the masterbatch prepared in step A2 and the black masterbatch in a casting extruder, and cast them on a cold roller at 80-110° C., cool them, and blow dry them to obtain a heat-resistant halogen-free flame-retardant modified polycarbonate film.

[0010] Furthermore, the raw materials are calculated in parts by weight as follows: 80-97 parts of polycarbonate raw material, 0.05-2 parts of dispersant, 0.3-0.6 parts of sulfonate flame retardant, 0.5-2 parts of silicone flame retardant, 0.2-0.5 parts of anti-dripping agent, 0.05-0.2 parts of dispersant, 0.1-1 parts of release agent, 0.05-1 parts of antioxidant, and 1-4 parts of black masterbatch.

[0011] Furthermore, in step A1, the polycarbonate raw material is prepared by mixing polycarbonate granules and polycarbonate powder at a mass ratio of 15-25:1.

[0012] Furthermore, in step A1, the particle size of the polycarbonate powder material is 10um-500um.

[0013] Furthermore, in step A1, the drying temperature of the polycarbonate raw material is 100-130°C, and the drying temperature of the sulfonate flame retardant, the silicone flame retardant and the anti-drip agent is 80-110°C.

[0014] Furthermore, in step A2, the dispersant is one or both of hydroxy silicone oil and dimethyl silicone oil, and the viscosity of the silicone oil at 25° C. ranges from 50 to 500 cSt.

[0015] Furthermore, in step A2, the anti-dripping agent is one or more of powdered polytetrafluoroethylene, polytetrafluoroethylene wax and silicone-coated polytetrafluoroethylene.

[0016] Furthermore, in step A3, the toner content in the black masterbatch is 20%-30%.

[0017] Furthermore, the antioxidant in step A3 is prepared by compounding a hindered phenol antioxidant and a phosphite antioxidant in a mass ratio of 1-5:1.

[0018] Furthermore, in step A3, the release agent is one or more of silicone, PPA and pentaerythritol stearate.

[0019] With polycarbonate as the matrix, the film is endowed with certain heat resistance and mechanical properties; the added sulfonate flame retardant, silicone flame retardant and anti-dripping agent can play a synergistic role to greatly enhance the flame retardant properties of the film; the added dispersant and release agent can improve processing stability and film forming; in addition, the added antioxidants are hindered phenol antioxidants and phosphite auxiliary antioxidants, the two can play a synergistic role to greatly enhance the antioxidant properties of the film; finally, the added black masterbatch can ensure that the film product is opaque.

[0020] Furthermore, the organosilicon flame retardant is prepared by the following steps:

[0021] S1. In a three-necked flask equipped with a stirring device, iminodiacetic acid, n-decanol and N,N-dimethylformamide (DMF) were stirred and mixed uniformly, dibutyltin oxide (catalyst) and dicyclohexylcarbodiimide (DCC, dehydrating agent) were added, the reaction temperature was controlled to 80° C., and the reaction was kept warm for 6 hours. Stirring was continued during the reaction. After the reaction was completed, the reaction was filtered, the solvent was removed by rotary evaporation, and vacuum drying was performed to obtain intermediate 1; the ratio of iminodiacetic acid, n-decanol, N,N-dimethylformamide, dibutyltin oxide and DCC was 15.2 g:15.8 g:100 mL:0.2 g:20.6 g;

[0022] Under the catalysis of dibutyltin oxide and DCC, the carboxyl group on the iminodiacetic acid and the hydroxyl group on the n-decanol undergo esterification reaction. By controlling the molar ratio of the two to be close to 1:1 and the iminodiacetic acid to be slightly excessive, only one carboxyl group on the iminodiacetic acid participates in the reaction to obtain intermediate 1. The specific reaction process is as follows:

[0023]

[0024] S2. At room temperature, in a three-necked flask equipped with a stirring device, the intermediate 1, dichlorodiphenylsilane, triethylamine and toluene were mixed and stirred uniformly under nitrogen protection, the reaction temperature was controlled to 75°C, and the reaction was kept warm for 5 hours. After the reaction was completed, the mixture was filtered, and part of the solvent was removed by vacuum distillation. The mixture was purified by column chromatography (the eluent was a mixed solvent of benzene / ethyl acetate in a volume ratio of 2:3), and the eluent was removed by rotary evaporation to obtain the intermediate 2; the ratio of the amount of the intermediate 1, dichlorodiphenylsilane, triethylamine and DMF was 58.1 g:25.1 g:15 mL:150 mL;

[0025] Intermediate 1 and dichlorodiphenylsilane undergo nucleophilic substitution, and the molar ratio of the two is controlled to be close to 2:1 and intermediate 1 is slightly excessive, and triethylamine removes the hydrogen chloride generated by the reaction to obtain intermediate 2; the specific reaction process is as follows:

[0026]

[0027] S3. In a three-necked flask equipped with a stirring device, the intermediate 2, ethanolamine, DCC (dehydrating agent) and toluene were mixed and stirred uniformly, and reacted for 6 hours under a 40°C water bath condition. After the reaction was completed, the mixture was filtered and purified by column chromatography (the eluent was a mixed solvent of petroleum ether / ethyl acetate in a volume ratio of 5:1), and the eluent was removed by rotary evaporation to obtain an organosilicon flame retardant; the ratio of the amount of intermediate 2, ethanolamine, DCC and toluene was 72.6 g:12.2 g:41.2 g:200 mL;

[0028] Under the action of the dehydrating agent, the carboxyl group on the intermediate 2 reacts with ethanolamine. Due to the mild conditions and the better activity of the amino group, the carboxyl group first undergoes an amidation reaction with the amino group, and the molar ratio of the intermediate 2 and ethanolamine is controlled to be close to 1:2 to obtain an organosilicon flame retardant. The specific reaction process is as follows:

[0029]

[0030] The prepared organosilicon flame retardant molecule contains Si-N flame retardant components, long carbon chains, benzene rings and hydroxyl groups, among which the Si-N flame retardant component has the synergistic flame retardant effect of silicon-based and nitrogen-based flame retardants, and compared with general silicon-based flame retardants in which silicon and oxygen are directly connected, Si-N is a covalent bond, has stable physical and chemical properties, and generates a dense Si-C or Si-Si layer during combustion, has a better flame retardant effect, and can synergize with sulfonate flame retardants and anti-dripping agents to greatly enhance the flame retardant properties of the matrix; not only that, the introduction of silicon elements can also enhance the heat resistance of the matrix; in addition, the introduced long carbon chain belongs to a methylene chain segment, which is a flexible chain segment, can improve the mechanical properties of the matrix, and can be interspersed in the macromolecular chain of the matrix to improve stability; the introduction of benzene rings can enhance the compatibility of organosilicon flame retardants with polycarbonate, so that the performance of organosilicon flame retardants can be fully exerted; finally, the two hydroxyl groups of the organosilicon flame retardant molecules can chemically bond with the polycarbonate matrix to further enhance the stability of the organosilicon flame retardant.

[0031] Beneficial effects of the present invention:

[0032] 1. The film prepared by the present invention uses polycarbonate as a matrix, which gives the film certain heat resistance and mechanical properties;

[0033] 2. The added dispersant and release agent can improve processing stability and film forming;

[0034] 3. The added antioxidant can play a synergistic role and greatly improve the antioxidant properties of the film;

[0035] 4. The added black masterbatch can ensure that the film product is opaque;

[0036] 5. The added organosilicon flame retardant can improve the heat resistance and mechanical properties of the film, and can also work synergistically with the sulfonate flame retardant and anti-dripping agent to significantly enhance the flame retardant properties of the film, and the performance is stable and not easy to fall off;

[0037] Therefore, the film prepared by the present invention is halogen-free and environmentally friendly, easy to form, opaque, has excellent mechanical properties and antioxidant properties, and has stable and efficient flame retardant and heat-resistant properties, and has important application value in the field of polycarbonate film technology. DETAILED DESCRIPTION

[0038] 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.

[0039] Example 1

[0040] Preparation of silicone flame retardant:

[0041] S1. In a three-necked flask equipped with a stirring device, 15.2 g of iminodiacetic acid, 15.8 g of n-decanol and 100 mL of N,N-dimethylformamide were stirred and mixed uniformly, and 0.2 g of dibutyltin oxide and 20.6 g of dicyclohexylcarbodiimide were added. The reaction temperature was controlled to 80° C. and the reaction was kept warm for 6 h. Stirring was continued during the reaction. After the reaction was completed, the reaction was filtered, the solvent was removed by rotary evaporation, and vacuum drying was performed to obtain intermediate 1.

[0042] S2. At room temperature, 58.1 g of intermediate 1, 25.1 g of dichlorodiphenylsilane, 15 mL of triethylamine and 150 mL of toluene were mixed and stirred evenly in a three-necked flask equipped with a stirring device under nitrogen protection. The reaction temperature was controlled to 75° C. and the reaction was kept warm for 5 hours. After the reaction was completed, the product was filtered and partially distilled off under reduced pressure. The product was then purified by column chromatography (the eluent was a mixed solvent of benzene / ethyl acetate in a volume ratio of 2:3), and the eluent was removed by rotary evaporation to obtain intermediate 2.

[0043] S3. In a three-necked flask equipped with a stirring device, 72.6 g of intermediate 2, 12.2 g of ethanolamine, 41.2 g of DCC and 200 mL of toluene were mixed and stirred evenly. The mixture was reacted for 6 h in a 40°C water bath. After the reaction was completed, the mixture was filtered and purified by column chromatography (the eluent was a mixed solvent of petroleum ether / ethyl acetate in a volume ratio of 5:1). The eluent was removed by rotary evaporation to obtain an organosilicon flame retardant.

[0044] Example 2

[0045] Preparation of silicone flame retardant:

[0046] S1. In a three-necked flask equipped with a stirring device, 30.4 g of iminodiacetic acid, 31.6 g of n-decanol and 200 mL of N,N-dimethylformamide were stirred and mixed uniformly, and 0.4 g of dibutyltin oxide and 41.2 g of dicyclohexylcarbodiimide were added. The reaction temperature was controlled to 80° C. and the reaction was kept warm for 6 h. Stirring was continued during the reaction. After the reaction was completed, the reaction was filtered, the solvent was removed by rotary evaporation, and vacuum drying was performed to obtain intermediate 1.

[0047] S2. At room temperature, 116.2 g of intermediate 1, 50.2 g of dichlorodiphenylsilane, 30 mL of triethylamine and 300 mL of toluene were mixed and stirred evenly in a three-necked flask equipped with a stirring device under nitrogen protection. The reaction temperature was controlled to 75° C. and the reaction was kept warm for 5 h. After the reaction was completed, the product was filtered and partially distilled off under reduced pressure. The product was then purified by column chromatography (the eluent was a mixed solvent of benzene / ethyl acetate in a volume ratio of 2:3), and the eluent was removed by rotary evaporation to obtain intermediate 2.

[0048] S3. In a three-necked flask equipped with a stirring device, 145.2 g of intermediate 2, 24.4 g of ethanolamine, 82.4 g of DCC and 400 mL of toluene were mixed and stirred evenly. The mixture was reacted for 6 h in a 40°C water bath. After the reaction was completed, the mixture was filtered and purified by column chromatography (the eluent was a mixed solvent of petroleum ether / ethyl acetate in a volume ratio of 5:1). The eluent was removed by rotary evaporation to obtain an organosilicon flame retardant.

[0049] Example 3

[0050] A1, 78g of polycarbonate raw material (mixed with 75g of polycarbonate granules and 3g of polycarbonate powder, the powder particle size is 10um) was dried at 120°C for 4 hours, and then 0.4g of sulfonate flame retardant, 0.8g of the organosilicon flame retardant prepared in Example 1 and 0.4g of polytetrafluoroethylene wax were dried at 80°C for 4 hours;

[0051] A2, the polycarbonate raw material dried in step A1 was stirred at a speed of 200 rpm for 3 minutes in a high-speed mixer, and then 0.1 g of hydroxy silicone oil (viscosity of 50 cSt at 25° C.) was added, and the mixture was stirred for 1 minute, and then added into a twin-screw extruder with a sulfonate flame retardant, an organosilicon flame retardant, and an anti-dripping agent, and melt-blended, extruded, and granulated to obtain a masterbatch;

[0052] A3. After drying, 0.2 g silicone and 0.1 g antioxidant (compounded with 0.05 g antioxidant 1010 and 0.05 g antioxidant 168) were stirred in a high-speed mixer at a speed of 200 rpm for 3-5 min, and then melt-extruded with the masterbatch prepared in step A2 and 2.5 g black masterbatch (color powder content of 20%) in a casting extruder, and then cast on a cold roller at 80° C., cooled, and blown dry to obtain a heat-resistant halogen-free flame-retardant modified polycarbonate film with a thickness of 0.5 mm.

[0053] Example 4

[0054] The main difference from Example 3 is that the amount of the organic silicon flame retardant is increased to 1 g, and the remaining steps are the same as Example 1.

[0055] Example 5

[0056] The main difference from Example 3 is that the amount of the organic silicon flame retardant is reduced to 0.5 g, and the remaining steps are the same as Example 1.

[0057] Example 6

[0058] The main difference from Example 3 is that the anti-dripping agent is increased to 0.5 g, and the remaining steps are the same as Example 1.

[0059] Example 7

[0060] A1, 78g of polycarbonate raw material (mixed with 75g of polycarbonate granules and 3g of polycarbonate powder, the powder particle size is 10um) was dried at 120°C for 4 hours, and then 0.4g of sulfonate flame retardant, 0.8g of the organosilicon flame retardant prepared in Example 2 and 0.4g of organosilicon-coated polytetrafluoroethylene were dried at 80°C for 4 hours;

[0061] A2, the polycarbonate raw material dried in step A1 was stirred at a speed of 500 rpm for 8 minutes in a high-speed mixer, and then 0.1 g of dimethyl silicone oil (viscosity of 500 cSt at 25° C.) was added, and the mixture was stirred for 4 minutes, and then added into a twin-screw extruder with a sulfonate flame retardant, an organosilicon flame retardant, and an anti-dripping agent, and melt-blended, extruded, and granulated to obtain a masterbatch;

[0062] A3. After drying 0.2 g of pentaerythritol stearate and 0.1 g of antioxidant (compounded with 0.05 g of antioxidant 1010 and 0.05 g of antioxidant 168), stir in a high-speed mixer at a speed of 700 rpm for 5 min, and then melt-extrude with the masterbatch obtained in step A2 and 2.5 g of black masterbatch (color powder content is 20%) in a casting extruder, and cast on a cold roller at 110° C., cool, and blow dry to obtain a heat-resistant halogen-free flame-retardant modified polycarbonate film with a thickness of 0.5 mm.

[0063] Example 8

[0064] The main difference from Example 7 is that the addition of the anti-dripping agent is eliminated, and the remaining steps are the same as Example 7.

[0065] Example 9

[0066] The main difference from Example 7 is that the amount of dispersant is increased to 0.2 g, and the remaining steps are the same as Example 7.

[0067] Example 10

[0068] The main difference from Example 7 is that the amount of release agent is increased to 0.3 g, and the remaining steps are the same as Example 7.

[0069] Comparative Example 1

[0070] The components were kept consistent with those in Example 3, but without preparing the masterbatch, all the raw material components were directly stirred in a high-speed mixer at 500 rpm for 5 minutes, extruded through a twin-screw extruder at a processing temperature of 250° C., and then cooled and dried to obtain a film.

[0071] Comparative Example 2

[0072] The main difference from Example 3 is that the amount of sulfonate flame retardant is increased to 1 g, and the remaining steps are the same as Example 3.

[0073] Comparative Example 3

[0074] The main difference from Example 3 is that the sulfonate flame retardant is reduced to 0.1 g, and the remaining steps are the same as Example 3.

[0075] Comparative Example 4

[0076] The main difference from Example 3 is that the addition of the organosilicon flame retardant is cancelled and replaced with 7g of phosphazene flame retardant. The remaining steps are the same as Example 3.

[0077] Comparative Example 5

[0078] The main difference from Example 7 is that the amount of anti-dripping agent used is 1.2 g, and the remaining steps are the same as Example 5.

[0079] Comparative Example 6

[0080] The main difference from Example 7 is that the anti-dripping agent is reduced to 0.1 g, and the remaining steps are the same as Example 5.

[0081] Comparative Example 7

[0082] The amount of black masterbatch used in Example 7 was reduced to 1 g, and the remaining steps were the same as in Example 7.

[0083] The performance tests of Examples 3-10 and Comparative Examples 1-7 were carried out, and the results are shown in the following table:

[0084]

[0085]

[0086] As can be seen from the above table, the film obtained in Examples 3-10 of the present invention has no problem in processing and forming feasibility, the tensile strength is greater than 60MPa, the elongation at break is above 90%, the prepared film product has no light transmission problem, the UL-94 flame retardant test can reach V0 level flame retardant, and the film product will not deform when tested at 140°C for 30min. It has important application value in the new energy battery and energy storage industry.

[0087] In addition, when the comparative example 1 is compared with the example 3, the flame retardant performance cannot reach the flame retardant V0 level when the organosilicon flame retardant and the anti-dripping agent are not prepared into a masterbatch;

[0088] Comparison between Example 2 and Example 3 shows that when the amount of sulfonate is too high, the molding performance of the overall material will be reduced;

[0089] Comparative Example 3 is compared with Example 3. When the amount of sulfonate flame retardant added is too low, the flame retardant performance of the material will drop to V2 level;

[0090] Comparative Example 4 is compared with Example 3. When the organosilicon flame retardant is replaced with a phosphazene flame retardant, the temperature resistance of the material decreases, and obvious deformation occurs at 130-135°C, and both the mechanical properties and the flame retardant properties decrease.

[0091] Comparison between Example 5 and Example 7 shows that when the overall content of the anti-drip agent is increased too much, the film will face the problem of difficult molding and cannot adapt to the cast film extrusion process;

[0092] Comparison between Example 6 and Example 7 shows that when the overall content of the anti-dripping agent is increased too little, the flame retardant performance will be significantly reduced;

[0093] Comparison between Comparative Example 7 and Example 7 shows that when the amount of black masterbatch added is too low, the film product will have a light transmittance problem.

[0094] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation 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.

[0095] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A method for preparing a heat-resistant halogen-free flame-retardant modified polycarbonate film, characterized in that: The following steps are involved: A1. Drying the polycarbonate raw material, the sulfonate flame retardant, the silicone flame retardant and the anti-dripping agent; A2, adding a dispersant to the polycarbonate raw material dried in step A1 after stirring, continuing stirring, and then adding it with a sulfonate flame retardant, a silicone flame retardant, and an anti-dripping agent into a twin-screw extruder, melt blending, extruding, and granulating to obtain a masterbatch; A3. After drying the release agent and antioxidant, stir them, and then melt-extrude them with the masterbatch and black masterbatch prepared in step A2 in a casting extruder, and then cast, cool and dry them on a cold roller to obtain a heat-resistant halogen-free flame-retardant modified polycarbonate film.

2. The method for preparing a heat-resistant halogen-free flame-retardant modified polycarbonate film according to claim 1, characterized in that: The organosilicon flame retardant is prepared by the following steps: S1, mixing iminodiacetic acid, n-decyl alcohol and N,N-dimethylformamide, adding dibutyltin oxide and dicyclohexylcarbodiimide, reacting at 80°C for 6h, stirring continuously during the reaction, filtering, rotary evaporating, and vacuum drying after the reaction is completed to obtain intermediate 1; S2, at room temperature, under nitrogen protection, the intermediate 1, dichlorodiphenylsilane, triethylamine and toluene were mixed and stirred evenly, reacted at 75°C for 5 hours, and after the reaction was completed, filtered, distilled under reduced pressure, purified by column chromatography, and rotary evaporated to obtain the intermediate 2; S3. Mix the intermediate 2, ethanolamine, DCC and toluene and stir them evenly. React them in a water bath at 40°C for 6 hours. After the reaction is completed, filter, purify by column chromatography, and rotary evaporate to obtain an organosilicon flame retardant.

3. The method for preparing a heat-resistant halogen-free flame-retardant modified polycarbonate film according to claim 2, characterized in that: In step S1, the ratio of the amount of iminodiacetic acid, n-decanol, N,N-dimethylformamide, dibutyltin oxide, and DCC is 15.2 g:15.8 g:100 mL:0.2 g:20.6 g.

4. The method for preparing a heat-resistant halogen-free flame-retardant modified polycarbonate film according to claim 2, characterized in that: In step S2, the ratio of the amount of intermediate 1, dichlorodiphenylsilane, triethylamine and DMF is 58.1 g: 25.1 g: 15 mL: 150 mL.

5. The method for preparing a heat-resistant halogen-free flame-retardant modified polycarbonate film according to claim 2, characterized in that: In step S3, the ratio of the amount of intermediate 2, ethanolamine, DCC, and toluene is 72.6 g: 12.2 g: 41.2 g: 200 mL.

6. The method for preparing a heat-resistant halogen-free flame-retardant modified polycarbonate film according to claim 1, characterized in that: The raw materials are calculated in parts by weight as follows: 80-97 parts of polycarbonate raw material, 0.05-2 parts of dispersant, 0.3-0.6 parts of sulfonate flame retardant, 0.5-2 parts of silicone flame retardant, 0.2-0.5 parts of anti-dripping agent, 0.05-0.2 parts of dispersant, 0.1-1 parts of release agent, 0.05-1 parts of antioxidant, and 1-4 parts of black masterbatch.

7. The method for preparing a heat-resistant halogen-free flame-retardant modified polycarbonate film according to claim 1, characterized in that: In step A1, the polycarbonate raw material is prepared by mixing polycarbonate granules and polycarbonate powder at a mass ratio of 15-25:

1.

8. The method for preparing a heat-resistant halogen-free flame-retardant modified polycarbonate film according to claim 1, characterized in that: In step A2, the dispersant is one or both of hydroxy silicone oil and dimethyl silicone oil, and the viscosity of the silicone oil at 25° C. ranges from 50 to 500 cSt.

9. The method for preparing a heat-resistant halogen-free flame-retardant modified polycarbonate film according to claim 1, characterized in that: The antioxidant in step A3 is prepared by compounding a hindered phenol antioxidant and a phosphite antioxidant in a mass ratio of 1-5:

1.

10. Application of the film obtained by the preparation method according to claim 1 in the new energy battery and energy storage industries.

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