High-temperature polyamide cast film and preparation method thereof

Abstract

The invention provides a high-temperature polyamide cast film. The raw material of the high-temperature polyamide cast film comprises high-temperature polyamide resin. Therefore, the high-temperature polyamide cast film disclosed by the invention not only has excellent mechanical properties, chemical resistance, dimensional stability, thickness uniformity, high temperature resistance and the like, but also can be endowed with different functions, such as low oxygen permeability, uniform color, flame retardance and the like; the method has important significance in expanding the application of polyamide in the fields of packaging, automobiles, new energy and the like.

Description

Technical Field

[0001] The invention belongs to the field of polymer materials, and in particular relates to a high-temperature polyamide cast film and a preparation method thereof. Background Art

[0002] At present, plastic products are widely used in various industries and in various forms. Among them, plastic film products have become one of the plastic products with the largest output and the most varieties in my country, and are widely used in packaging, electronics, automobiles, construction, new energy and other fields. In addition to the common PE, PVC, and PS films, biaxially oriented films are new film materials that have developed rapidly in recent years, but the common disadvantage of these materials is poor temperature resistance. Summary of the invention

[0003] In one aspect of the present invention, the present invention provides a high temperature polyamide cast film. According to an embodiment of the present invention, the raw material of the high temperature polyamide cast film includes a high temperature polyamide resin.

[0004] In some specific embodiments, the relative viscosity of the high temperature polyamide resin is 2.4-2.8, such as 2.45, 2.50, 2.55, 2.60, 2.65, 2.70, 2.75, etc. The relative viscosity is measured by an Ubbelohde viscometer with concentrated sulfuric acid (concentration 96%) method.

[0005] In some embodiments, the water content of the high temperature polyamide resin is not greater than 2000 ppm, preferably not greater than 500 ppm. The drying method is adjusted according to actual application, and the drying method is not particularly limited.

[0006] In some embodiments, the high temperature polyamide resin has a melting point of 260-300°C, such as 270°C, 280°C, 290°C, 300°C, etc.

[0007] In some embodiments, the high temperature polyamide resin is prepared using diamine monomer A1, aliphatic diacid monomer A2 and aromatic diacid monomer A3. Preferably, the bio-based high temperature polyamide resin contains repeating structural units from bio-based pentamethylenediamine, has the advantage of being renewable, and can be commercially available, provided by Cathay Biotech Inc. A series of materials, such as wait.

[0009] In some embodiments, the diamine monomer A1 includes at least one of butanediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecanediamine, dodecamethylenediamine, tridecanediamine, tetradecanediamine, pentamethylenediamine, and hexadecanediamine. Preferably, the diamine monomer A1 contains at least pentamethylenediamine.

[0010] In some embodiments, the pentamethylenediamine is derived from bio-based pentamethylenediamine, which refers to pentamethylenediamine synthesized from biomass-derived compounds such as glucose and lysine by enzyme reaction, yeast reaction or fermentation reaction in a monomer synthesis process. The biobased content of bio-based pentamethylenediamine can be determined by a method for measuring the radioactive C14 content, such as the American Society for Testing and Materials standard ASTM-D6866 method.

[0011] In some embodiments, the molar percentage of pentamethylenediamine in all diamine units A1 is 20-70%.

[0012] In some embodiments, the aliphatic diacid monomer A2 is derived from an aliphatic short-chain diacid, an aliphatic long-chain diacid or a combination thereof. The aliphatic short-chain diacid can be, for example, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid or a combination thereof; the aliphatic long-chain diacid can be, for example, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecane dibasic acid, hexadecanedioic acid, heptadecanedioic acid, octadecane dibasic acid or a combination thereof.

[0013] In some embodiments, the aliphatic diacid unit is derived from a combination of an aliphatic short-chain diacid and an aliphatic long-chain diacid, wherein the aliphatic short-chain diacid is, for example, adipic acid, and the aliphatic long-chain diacid is, for example, selected from sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecane dicarboxylic acid, hexadecanedioic acid, or a combination thereof.

[0014] In some embodiments, the aromatic diacid unit A3 is derived from an aromatic diacid or a derivative thereof, such as terephthalic acid, isophthalic acid, phthalic acid or a combination of esters thereof. For example, terephthalic acid esters include dimethyl terephthalate and diethyl terephthalate.

[0015] In some embodiments, at least one of the diamine monomer A1, the aliphatic diacid monomer A2, and the aromatic diacid monomer A3 is prepared by a biological method.

[0016] In some embodiments, the molar ratio of the diamine monomer A1 to the sum of the aliphatic diacid monomer A2 and the aromatic diacid monomer A3 is 0.9 to 1.2, or further 0.95 to 1.1.

[0017] In some embodiments, the molar ratio of the aliphatic diacid monomer A2 to the aromatic diacid monomer A3 is (10-50):(50-90), or further is (20-50):(50-75).

[0018] In some embodiments, the high temperature polyamide cast film further includes an additive, wherein the additive includes at least one of an antioxidant, a dye inhibitor, a filler, a masterbatch, an antistatic agent, and a lubricant.

[0019] In some embodiments, the mass ratio of the high temperature polyamide resin to the additive is (85-99):(1-15).

[0020] In a second aspect of the present invention, the present invention describes a method for preparing the high temperature polyamide cast film described in the first aspect of the present invention. According to an embodiment of the present invention, the method comprises: melting the high temperature polyamide resin through an extruder, casting it onto a cooling roller through a T-die, and finally obtaining the high temperature polyamide cast film by traction and winding.

[0021] In some specific embodiments, the relative viscosity of the high temperature polyamide resin is 2.4-2.8, such as 2.45, 2.50, 2.55, 2.60, 2.65, 2.70, 2.75, etc. The relative viscosity is measured by an Ubbelohde viscometer with concentrated sulfuric acid (concentration 96%) method.

[0022] In some embodiments, the high temperature polyamide resin has a melting point of 260-300°C, such as 260°C, 270°C, 280°C, 290°C, 300°C, etc.

[0023] In some embodiments, the water content of the high temperature polyamide resin is not greater than 2000 ppm, preferably not greater than 500 ppm. The drying method is adjusted according to actual application, and the drying method is not particularly limited.

[0024] In some embodiments, the melting is performed in a twin-screw extruder. The inventors have found that high-temperature polyamide resin can be better mixed and plasticized in a twin-screw system, thereby improving defects such as crystal points on the surface of the formed film.

[0025] In some embodiments, an additive is added during the melting process, and the mass ratio of the high temperature polyamide resin to the additive is (85-99): (1-15).

[0026] In some embodiments, the processing temperature of the twin-screw extruder is 160-310°C.

[0027] In some embodiments, the twin-screw extruder is heated in 9 zones, and the temperature of one zone of the twin-screw extruder is 160-250°C.

[0028] In some embodiments, the temperature of the second zone of the twin-screw extruder is 220-300°C.

[0029] In some embodiments, the temperature of the three zones of the twin-screw extruder is 240-305°C.

[0030] In some embodiments, the temperature of the four zones of the twin-screw extruder is 260-310°C.

[0031] In some embodiments, the temperature of the fifth zone of the twin-screw extruder is 260-310°C.

[0032] In some embodiments, the temperature of zone 6 of the twin-screw extruder is 260-310°C.

[0033] In some embodiments, the temperature of zone 7 of the twin-screw extruder is 260-310°C.

[0034] In some embodiments, the temperature of zone eight of the twin-screw extruder is 260-310°C.

[0035] In some embodiments, the temperature of the ninth zone of the twin-screw extruder is 260-310°C.

[0036] In some embodiments, the screw speed of the twin-screw extruder is 10-30 r / min, and the aspect ratio is 1:(36-44).

[0037] In some embodiments, the processing temperature of the T-die is 240-310°C.

[0038] In some embodiments, the T-shaped mold is heated in five zones, and the temperature of one zone of the T-shaped mold is 260-310°C.

[0039] In some embodiments, the temperature of the second zone of the T-die is 240-305°C.

[0040] In some embodiments, the temperature of the three zones of the T-die is 240-305°C.

[0041] In some embodiments, the temperature of the four zones of the T-die is 260-305°C.

[0042] In some embodiments, the temperature of the five zones of the T-die is 260-310°C.

[0043] In some embodiments, the pulling speed is 6 m / min to 18 m / min, for example, 7 m / min, 8 m / min, 9 m / min, 10 m / min, 11 m / min, 12 m / min, 13 m / min, 14 m / min, 15 m / min, 16 m / min, 17 m / min, etc.

[0044] In some embodiments, the lip opening of the T-die is 0.02 mm to 0.2 mm, for example, 0.04 mm, 0.06 mm, 0.08 mm, 0.1 mm, 0.12 mm, 0.14 mm, 0.16 mm, 0.18 mm, etc.

[0045] The beneficial effects of the present invention are as follows: the high-temperature polyamide cast film of the present invention not only has excellent mechanical properties, chemical resistance, dimensional stability, thickness uniformity, and high temperature resistance, but also can give the cast film different functions by adding additives, such as low oxygen permeability, uniform color, flame retardancy, etc., which is of great significance for expanding the application of polyamide in packaging, automotive fields, new energy and other fields. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are 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.

[0047] Commercially available PA66 resin (melting point of 220°C, relative viscosity of 2.7, purchased from Pingdingshan Shenma Engineering Plastics Co., Ltd.) and commercially available PA6 resin (melting point of 220°C, relative viscosity of 2.5, purchased from Guangzhou Xinhui Meida Nylon Co., Ltd.), red masterbatch and gray masterbatch were purchased from Xiamen Yixingxing Plastic Raw Materials Co., Ltd., antioxidants were purchased from Dover Chemical Company, and flame retardants were purchased from Clariant Chemicals (China) Co., Ltd.

[0048] Bio-based high temperature polyamide resin A: For raw materials and preparation methods, refer to Example 4 of the patent publication CN 112029090 A, and obtain bio-based high temperature polyamide resin A (number average molecular weight of 30,000, relative viscosity of 2.7, water content of 850 ppm after drying, melting point of 282°C).

[0049] Bio-based high temperature polyamide resin B: 10.2 mol of bio-based pentamethylenediamine, 2.9 mol of dodecanedioic acid and 6.9 mol of terephthalic acid are used as raw materials. The preparation method is as shown in Example 7 of the patent publication CN 112029090 A, and a bio-based high temperature polyamide resin B (number average molecular weight of 25,800, relative viscosity of 2.43, water content of 690 ppm after drying, melting point of 302° C.) is obtained;

[0050] Bio-based high temperature polyamide resin C: 7.05 mol bio-based pentamethylenediamine, 7 mol terephthalic acid, 3 mol 1,6-hexanodioic acid, 3 mol 1,6-hexanediamine, 0.03% sodium hypophosphite and water were mixed evenly, the stirring speed was set to 80 rpm, the temperature was raised to 80°C in a nitrogen atmosphere and maintained at the temperature for 1 hour to obtain a 50wt% polyamide salt solution, the temperature was raised to 130°C, the water was drained and concentrated to a concentration of 65wt%; the temperature was raised to 240°C again, and the pressure was maintained at 2.5MPa for reaction for 1 hour; the pressure in the reaction system was reduced to 0MPa by draining water, and the temperature of the reaction system was 340°C after the pressure reduction was completed; the vacuum was evacuated to -0.08MPa and maintained for 40s to obtain a polyamide melt; the polyamide melt was water-cooled and pelletized to obtain a bio-based high-temperature polyamide resin C (number average molecular weight of 21,000, relative viscosity of 2.23, water content of 1045ppm after drying, melting point of 308°C).

[0051] Example 1

[0052] (1) drying bio-based high temperature polyamide resin A chips to 500 ppm, with a melting point of 282° C. and a viscosity of 2.7;

[0053] (2) The dry chips obtained in step (1) are melted by an extruder, wherein 99 parts of bio-based high temperature polyamide resin A and 1 part of antioxidants 1098 and 168 are compounded, and then the melt is cast through a T-die onto a cooling roller with a surface temperature of 36° C., and finally the corresponding high temperature polyamide cast film is obtained by traction and winding, wherein the traction rate is 6 m / min, the die lip opening is 0.1 mm,

[0054] The twin-screw extruder and T-die adopt 9-zone and 5-zone heating modes, the temperature of the twin-screw extruder is 220℃, 275℃, 280℃, 280℃, 285℃, 285℃, 285℃, 285℃, 285℃; the temperature of the T-die is 280℃, 275℃, 275℃, 275℃, 280℃; the screw speed is 27r / min; the aspect ratio of the twin-screw extruder is 1:40. Water cooling is used for cooling.

[0055] Example 2

[0056] (1) drying bio-based high temperature polyamide resin C chips to 500 ppm, with a melting point of 308°C and a viscosity of 2.23;

[0057] (2) The dry chips obtained in step (1) are melted by an extruder, wherein 99 parts of bio-based high temperature polyamide resin C and 1 part of antioxidants 1098 and 9228 are compounded, and then the melt is cast through a T-die onto a cooling roller with a surface temperature of 40° C., and finally the corresponding high temperature polyamide cast film is obtained by traction and winding, wherein the traction rate is 6 m / min, the die lip opening is 0.1 mm,

[0058] The twin-screw extruder and T-die adopt 9-zone and 5-zone heating modes. The temperature of the twin-screw extruder is 250℃, 280℃, 300℃, 305℃, 305℃, 305℃, 305℃, 305℃, 305℃; the temperature of the T-die is 305℃, 300℃, 300℃, 300℃, 305℃; the screw speed is 27r / min; the aspect ratio of the twin-screw extruder is 1:40. Water cooling is used for cooling.

[0059] Example 3

[0060] (1) drying bio-based high temperature polyamide resin C chips to 500 ppm, with a melting point of 308°C and a viscosity of 2.23;

[0061] (2) The dry chips obtained in step (1) are melted by an extruder, wherein 96 parts of bio-based high temperature polyamide resin C, 1 part of antioxidant 1098 and 9228, and 3 parts of red masterbatch are added, and then the melt is cast through a T-die onto a cooling roller with a surface temperature of 50° C., and finally the corresponding high temperature polyamide cast film is obtained by traction and winding, wherein the traction rate is 6 m / min, the die lip opening is 0.1 mm,

[0062] The twin-screw extruder and T-die adopt 9-zone and 5-zone heating modes. The temperature of the twin-screw extruder is 250℃, 280℃, 300℃, 305℃, 305℃, 305℃, 305℃, 305℃, 305℃; the temperature of the T-die is 305℃, 300℃, 300℃, 300℃, 305℃; the screw speed is 27r / min; the aspect ratio of the twin-screw extruder is 1:40. Water cooling is used for cooling.

[0063] Example 4

[0064] (1) drying bio-based high temperature polyamide resin C chips to 500 ppm, with a melting point of 308°C and a viscosity of 2.23;

[0065] (2) The dry chips obtained in step (1) are melted by an extruder, wherein 96 parts of bio-based high temperature polyamide resin C, 1 part of antioxidant 1098 and 9228 are compounded, and 3 parts of gray masterbatch are added, and then the melt is cast through a T-die onto a cooling roller with a surface temperature of 50° C., and finally the corresponding high temperature polyamide cast film is obtained by traction and winding, wherein the traction rate is 6 m / min, the die lip opening is 0.1 mm,

[0066] The twin-screw extruder and T-die adopt 9-zone and 5-zone heating modes. The temperature of the twin-screw extruder is 250℃, 280℃, 300℃, 305℃, 305℃, 305℃, 305℃, 305℃, 305℃; the temperature of the T-die is 305℃, 300℃, 300℃, 300℃, 305℃; the screw speed is 27r / min; the aspect ratio of the twin-screw extruder is 1:40. Water cooling is used for cooling.

[0067] Example 5

[0068] (1) drying bio-based high temperature polyamide resin B chips to a moisture content of 500 ppm, a melting point of 302° C., and a viscosity of 2.43;

[0069] (2) The dry chips obtained in step (1) are melted by an extruder, wherein 99 parts of the resin and 1 part of the antioxidants 1098 and 9228 are compounded, and then the melt is cast through a T-die onto a cooling roller with a surface temperature of 50° C., and finally the corresponding high-temperature polyamide cast film is obtained by traction and winding, wherein the traction rate is 6 m / min and the die lip opening is 0.1 mm.

[0070] The twin-screw extruder and T-die adopt 9-zone and 5-zone heating modes. The temperature of the twin-screw extruder is 250℃, 295℃, 305℃, 310℃, 310℃, 310℃, 310℃, 305℃, 305℃; the temperature of the T-die is 310℃, 300℃, 300℃, 300℃, 310℃; the screw speed is 27r / min; the aspect ratio of the twin-screw extruder is 1:40. Water cooling is used for cooling.

[0071] Example 6

[0072] (1) drying bio-based high temperature polyamide resin B chips to a moisture content of 500 ppm, a melting point of 302° C., and a viscosity of 2.43;

[0073] (2) The dry chips obtained in step (1) are melted by an extruder, wherein 88 parts of resin, 1 part of antioxidant 1098 and 9228 are compounded, and 11 parts of flame retardant (ADP) are added; then the melt is cast through a T-die onto a cooling roller with a surface temperature of 50° C., and finally the corresponding high-temperature polyamide cast film is obtained by traction and winding, wherein the traction rate is 6 m / min, the die lip opening is 0.1 mm,

[0074] The twin-screw extruder and T-die adopt 9-zone and 5-zone heating modes. The temperature of the twin-screw extruder is 250℃, 295℃, 305℃, 310℃, 310℃, 310℃, 310℃, 305℃, 305℃; the temperature of the T-die is 310℃, 300℃, 300℃, 300℃, 310℃; the screw speed is 27r / min; the aspect ratio of the twin-screw extruder is 1:40. Water cooling is used for cooling.

[0075] Comparative Example 1

[0076] PA66 film, preparation method is as follows:

[0077] (1) Dry PA66 resin chips to a moisture content of 500 ppm and a viscosity of 2.7;

[0078] (2) The dry chips obtained in step (1) are melted by an extruder, wherein the resin is 99 parts, and the antioxidants 1098 and 168 are compounded to 1 part, and then the melt is cast through a T-die to a cooling roller with a surface temperature of 30° C., and finally the corresponding high-temperature polyamide cast film is obtained by traction and winding, wherein the traction rate is 6 m / min and the die lip opening is 0.1 mm;

[0079] The twin-screw extruder and T-die adopt 9-zone and 5-zone heating modes, the temperature of the twin-screw extruder is 240℃, 280℃, 290℃, 290℃, 290℃, 290℃, 290℃, 290℃, 290℃; the temperature of the T-die is 285℃, 280℃, 280℃, 280℃, 285℃; the screw speed is 27r / min; the aspect ratio of the twin-screw extruder is 1:40. Water cooling is used for cooling.

[0080] Comparative Example 2

[0081] PA6 film, preparation method is as follows:

[0082] (1) Dry PA6 resin chips to a moisture content of 500 ppm and a viscosity of 2.3;

[0083] (2) The dry chips obtained in step (1) are melted by an extruder, wherein the resin is 99 parts, and the antioxidants 1098 and 168 are compounded to 1 part, and then the melt is cast through a T-die to a cooling roller with a surface temperature of 30° C., and finally the corresponding high-temperature polyamide cast film is obtained by traction and winding, wherein the traction rate is 6 m / min and the die lip opening is 0.1 mm;

[0084] The twin-screw extruder and T-die adopt 9-zone and 5-zone heating modes. The temperature of the twin-screw extruder is 160℃, 200℃, 245℃, 250℃, 250℃, 250℃, 250℃, 250℃, 245℃; the temperature of the T-die is 245℃, 240℃, 240℃, 240℃, 245℃; the screw speed is 27r / min; the aspect ratio of the twin-screw extruder is 1:40. Water cooling is used for cooling.

[0085] The cast films obtained in the above embodiments and comparative examples were subjected to performance tests, wherein the relevant tests involved are as follows:

[0086] 1. Relative viscosity: measured by the concentrated sulfuric acid method with an Ubbelohde viscometer, accurately weigh 0.25±0.0002 g of the dried polyamide resin, add 50 mL of concentrated sulfuric acid (96 wt%) to dissolve; measure and record the time t of the concentrated sulfuric acid flowing through in a 25°C constant temperature water bath. 0 and polyamide sample solution flow time t; viscosity calculation formula: relative viscosity = t / t 0 ; t—solution flow time; t 0 —Solvent flow time.

[0087] 2. Melting point: refer to ASTM D3418-2003.

[0088] 3. Water absorption rate: The test refers to the standard ASTM-D570-2005 test method for water absorption of plastics, and the test time is 24 hours.

[0089] 4. Mechanical properties: The tensile test refers to the standard GB / T 1040.3-2006; the elongation at break test refers to the standard GB / T 1040.3-2006; MD (machine direction) refers to the mechanical tensile direction or longitudinal direction; TD (transverse direction) refers to the direction perpendicular to the machine direction or transverse direction.

[0090] 5. Oxygen permeability: measured in accordance with ASTM D-3985.

[0091] 6. Haze: measured in accordance with standard GB / T2410-2008.

[0092] 7. Resistance to UV yellowing: measured in accordance with ASTM G154-2016.

[0093] The data obtained are shown in Table 1.

[0094] Table 1

[0095]

[0096] From the results in Table 1, it can be seen that the high-temperature polyamide cast film obtained by the present invention not only has excellent mechanical properties, but also has low oxygen permeability, and can be applied to various engineering plastic fields that have high requirements on film mechanical properties, barrier properties and thickness. In addition, the present invention can be used to develop various functional films for the needs of other fields, and has better high temperature resistance.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high temperature polyamide cast film, characterized in that: The raw material of the high-temperature polyamide cast film includes a high-temperature polyamide resin. The high-temperature polyamide resin has a relative viscosity of 2.4 to 2.8, a melting point of 260-300° C., and a water content of no more than 2000 ppm.

2. The high temperature polyamide cast film according to claim 1, characterized in that: The high temperature polyamide resin is prepared by using diamine monomer A1, aliphatic diacid monomer A2 and aromatic diacid monomer A3; and / or, The diamine monomer A1 includes at least one of butanediamine, pentanediamine, hexanediamine, heptanediamine, octanediamine, nonanediamine, decanediamine, undecanediamine, dodecanediamine, tridecanediamine, tetradecanediamine, pentadecanediamine and hexadecanediamine; and / or, The aliphatic diacid monomer A2 includes at least one of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedicarboxylic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedicarboxylic acid, hexadecanedioic acid, heptadecanedioic acid, and octadecanedicarboxylic acid; and / or, the aromatic diacid monomer A3 includes at least one of terephthalic acid, isophthalic acid, and phthalic acid; and / or, At least one of the diamine monomer A1, the aliphatic diacid monomer A2 and the aromatic diacid monomer A3 is prepared by a biological method.

3. The high temperature polyamide cast film according to claim 2, characterized in that: The molar ratio of the diamine monomer A1 to the total of the aliphatic diacid monomer A2 and the aromatic diacid monomer A3 is 0.9 to 1.2, and further 0.95 to 1.1; and / or, The molar ratio of the aliphatic diacid monomer A2 to the aromatic diacid monomer A3 is (10-50):(50-90), preferably (20-50):(50-75).

4. The high temperature polyamide cast film according to claim 1, characterized in that: The high temperature polyamide cast film further comprises additives, wherein the additives comprise at least one of an antioxidant, a dye inhibitor, a filler, a masterbatch, an antistatic agent and a lubricant.

5. The high temperature polyamide cast film according to claim 5, characterized in that: The mass ratio of the high temperature polyamide resin to the additive is (85-99):(1-15).

6. A method for preparing a high temperature polyamide cast film as claimed in any one of claims 1 to 5, characterized in that: The method comprises: melting the high-temperature polyamide resin through an extruder, casting the resin onto a cooling roller through a T-shaped die, and finally obtaining a high-temperature polyamide cast film by traction and winding.

7. The method according to claim 6, characterized in that The high temperature polyamide resin has a relative viscosity of 2.4 to 2.8, a melting point of 260 to 300° C., and a water content of no more than 2000 ppm; and / or, Additives are added during the melting process, and the mass ratio of the high-temperature polyamide resin to the additive is (85-99): (1-15).

8. The method according to claim 6, characterized in that The melting is carried out in a twin-screw extruder, the processing temperature of the twin-screw extruder is 160-310° C.; and / or, the screw speed of the twin-screw extruder is 10-30 r / min; and / or, The length-to-diameter ratio of the twin-screw extruder is 1:(36-44).

9. The method according to claim 6, characterized in that The processing temperature of the T-shaped die is 240-310°C.

10. The method according to claim 6, characterized in that The pulling speed is 6m / min to 18m / min, and the die lip opening is 0.02mm to 0.2mm.

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