High-temperature-resistant food packaging film and preparation method thereof

Abstract

The application relates to the packaging technical field and particularly relates to a high-temperature-resistant food packaging film and a preparation method thereof, which comprises modified polypropylene, modified talcum powder, gamma-aminopropyl triethoxysilane and erucamide. By inducing polypropylene heterogeneous nucleation, the beta crystal modified polypropylene with a hexagonal spherical crystal structure is formed, and the beta crystal modified polypropylene can keep good toughness under long-term low-temperature conditions and will not be brittle and cracked to expose the contents. The maleic anhydride grafting of the modified talcum powder is tangled with the molecular chains of the modified polypropylene, the movement of the molecular chains is prevented, and the conversion of the modified polypropylene from the beta crystal to the alpha crystal is hindered. The gamma-aminopropyl triethoxysilane is combined with the modified talcum powder to form a composite structure of silane end-talcum powder-maleic anhydride grafting-modified polypropylene molecular chains, the alpha crystal nucleation sites of the modified talcum powder are completely covered, and the hindering effect of the modified talcum powder is further strengthened.

Description

Technical Field

[0001] This invention relates to the field of packaging technology, specifically to a high-temperature resistant food packaging film and its preparation method. Background Technology

[0002] Currently, polypropylene or polyethylene is widely used to make high-temperature resistant food packaging films due to its heat resistance and stable properties. These films can package oily liquids like hot pot broth. However, the focus is only on high-temperature stability, without considering whether the material properties will remain suitable under different environments during use. Unused hot pot broth after opening is usually stored in the refrigerator. Prolonged exposure to low temperatures can cause the plastic food film to harden, become brittle, and crack, exposing the contents, which is detrimental to food safety and human health. Summary of the Invention

[0003] (1) Technical problems to be solved

[0004] The purpose of this invention is to provide a high-temperature resistant food packaging film and its preparation method, which can maintain good toughness under long-term low-temperature conditions, prevent plastic food films from hardening and becoming brittle, and prevent cracking and exposing the contents, thus ensuring food safety and human health.

[0005] (2) Technical solution

[0006] To achieve the above objectives, on the one hand, the present invention provides a high-temperature resistant food packaging film, the raw materials comprising, by weight: 200-300 parts of modified polypropylene, 20-30 parts of modified talc, 0.2-0.9 parts of γ-aminopropyltriethoxysilane, and 0.2-0.9 parts of erucamide.

[0007] The modified polypropylene has a β-crystal form with a hexagonal spherical crystal structure.

[0008] The modified polypropylene is produced by physical blending polypropylene with N,N'-dinaphthyloxalamide. The rigid benzene ring structure of N,N'-dinaphthyloxalamide serves as a heterogeneous nucleation site, promoting the orderly arrangement of polypropylene molecular chains and improving the crystallinity of β crystals.

[0009] The talc-maleic anhydride graft on the surface of the modified talc is generated through esterification and acid-base reactions between the carboxyl groups of maleic anhydride and the silanol and magnesium hydroxyl groups on the surface of talc.

[0010] Furthermore, the method for preparing the modified polypropylene includes the following steps:

[0011] S11. Polypropylene granules, N,N'-dinaphthyloxalamide, antioxidant 1010 and calcium stearate are premixed in a high-speed mixer for 1 to 1.5 hours to obtain a premix.

[0012] S12. Transfer the premix to a twin-screw extruder, melt-blend for 3 hours at a temperature of 180~220℃, and then extrude and granulate to obtain modified polypropylene.

[0013] Furthermore, the premixed raw materials are composed of the following weight ratios: 92-95 parts polypropylene particles, 0.4-0.5 parts N,N'-dinaphthyloxalamide, 0.2 parts antioxidant 1010, and 0.1 parts calcium stearate.

[0014] Furthermore, the preparation method of the modified talc powder includes the following steps:

[0015] S21. Dry the talc powder in a constant temperature drying oven at 105℃ for 1.5~2h to obtain talc powder without adsorbed water;

[0016] S22. Talc powder without adsorbed water, maleic anhydride, and dicumyl peroxide are premixed in a high-speed mixer for 10-15 minutes to obtain a mixture;

[0017] S23. Transfer the mixture to a twin-screw extruder and react it at a temperature of 160~180℃ for 5~10 min. After cooling, crush it with a pulverizer and sieve it to obtain modified talc powder.

[0018] Further, the raw materials in the mixture are configured in the following weight ratio: 100-110 parts talc, 1-5 parts maleic anhydride, and 0.1-0.5 parts dicumyl peroxide.

[0019] On the other hand, based on the same inventive concept, the present invention also provides a method for preparing a high-temperature resistant food packaging film, which is applied to the aforementioned high-temperature resistant food packaging film, comprising the following steps:

[0020] S31. Preparation of modified polypropylene;

[0021] S32. Preparation of modified talc powder;

[0022] S33. Modified polypropylene, modified talc, γ-aminopropyltriethoxysilane, and erucamide are fed into a twin-screw extruder, melt-blended for 3 hours, extruded through a ring die, and shaped by a cooling air ring to obtain a high-temperature resistant food packaging film.

[0023] Furthermore, the temperature conditions for the melt blending are 180~200℃.

[0024] Furthermore, the control conditions for extrusion through the annular die are a blow-up ratio (BUR) of 2~4:1 and a traction rate of 10~15m / min.

[0025] The mechanism of action of the above raw material components is as follows:

[0026] Modified polypropylene is a thermally stable material. Through physical blending of polypropylene with N,N'-dinaphthyloxalamide, the rigid benzene ring structure of N,N'-dinaphthyloxalamide serves as a heterogeneous nucleation site, promoting the ordered arrangement of polypropylene molecular chains and increasing the crystallinity of the β-crystal form. N,N'-dinaphthyloxalamide possesses a stable conjugated structure in the polypropylene system, and its hydroxyl groups can form hydrogen bonds. These two factors work together to stabilize polypropylene segments, promote the crystallization process, and enhance nucleation ability. Furthermore, the side chains of N,N'-dinaphthyloxalamide contain conjugated π bonds, which not only stabilize polypropylene segments but also provide nucleation sites. The hydroxyl functional groups can form hydrogen bonds in the amorphous phase, thus promoting the stability of the spherulites formed by polypropylene. The resulting β-crystal modified polypropylene has a hexagonal spherical crystal structure, enhancing tensile strength and maintaining good toughness even at an ambient temperature of -20℃.

[0027] The β-form is a thermodynamically metastable crystal form, while the α-form has higher crystallinity and a more tightly packed polypropylene molecular chain, thus exhibiting better thermodynamic stability. Under normal circumstances, the β-form gradually transforms into the α-form. The α-form has poor toughness; if this transformation is not prevented, as the β-crystal content decreases, the food film will harden and become brittle at low temperatures, increasing the risk of contents exposure and posing a threat to food safety and human health.

[0028] Talc itself is a lubricant, and its surface contains silanol groups (Si-OH) and magnesium hydroxyl groups (Mg-OH). These active groups can react with the carboxyl groups (-COOH) of maleic anhydride (MAH) in the following ways: esterification with silanol groups, the reaction equation is: Si-OH + MAH → Si-O-CO-CH=CH-COOH + H2O; acid-base reaction with magnesium hydroxyl groups, the reaction equation is: Mg-OH + MAH → Mg-O-CO-CH=CH-COOH + H2O. Through esterification and acid-base reactions, talc-maleic anhydride grafts are formed on the surface of modified talc. The olefin chains (-CH=CH-) of maleic anhydride become entangled with the modified polypropylene molecular chains, preventing the movement of the molecular chains and thus hindering the transformation of the modified polypropylene from the β-phase to the α-phase.

[0029] γ-Aminopropyltriethoxysilane is an organosilicon compound with a unique structure. The silanol forms stable Si-O-Si covalent bonds with the silanol on the surface of modified talc. This forms a composite structure of silane-terminal talc-maleic anhydride-grafted modified polypropylene molecular chains, completely covering the α-crystal nucleation sites of the modified talc and further strengthening the inhibitory effect of modified talc on the transformation of the modified polypropylene from the β-crystal to the α-crystal form.

[0030] The surface of β-crystalline modified polypropylene is relatively rough. During processing, erucamide will migrate to the surface of modified polypropylene to form a monomolecular lubricating layer, which improves the smoothness of the film.

[0031] (3) Beneficial effects

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] 1. N,N'-Dinaphthyloxalamide induces heterogeneous nucleation to form β-crystalline modified polypropylene. Under long-term low-temperature conditions, the hexagonal spherical crystal structure maintains its good toughness and will not become brittle and crack to expose the contents, thus ensuring food safety and human health.

[0034] 2. The maleic anhydride grafting of modified talc powder entangles with the molecular chains of modified polypropylene, preventing the movement of the molecular chains and thus hindering the transformation of the modified polypropylene from β-crystal to α-crystal.

[0035] 3. The resulting composite structure of silane-terminated talc-maleic anhydride-grafted modified polypropylene molecular chains completely covers the α-crystal nucleation sites of modified talc, further enhancing the inhibitory effect of modified talc on crystal transformation. Attached Figure Description

[0036] Figure 1 This is a PLM diagram of the β crystals of the modified polypropylene in Example 1 of the present invention. Detailed Implementation

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

[0038] Example 1

[0039] This embodiment discloses a high-temperature resistant food packaging film, the raw materials of which include, by weight: 200 parts modified polypropylene, 20 parts modified talc, 0.2 parts γ-aminopropyltriethoxysilane, and 0.2 parts erucamide.

[0040] The modified polypropylene has a β-crystal form with a hexagonal spherical crystal structure. The β-crystal structure of the modified polypropylene is as follows: Figure 1 As shown.

[0041] The modified polypropylene is obtained by physical blending polypropylene with N,N'-dinaphthyloxalamide. The rigid benzene ring structure of N,N'-dinaphthyloxalamide serves as a heterogeneous nucleation site, promoting the orderly arrangement of polypropylene molecular chains and improving the crystallinity of β crystals.

[0042] The talc-maleic anhydride graft on the surface of the modified talc is generated through esterification and acid-base reactions between the carboxyl groups of maleic anhydride and the silanol and magnesium hydroxyl groups on the surface of talc.

[0043] The rigid benzene ring structure of N,N'-dinaphthyloxalamide serves as a heterogeneous nucleation site, promoting the ordered arrangement of polypropylene molecular chains and facilitating β-crystal crystallization. N,N'-dinaphthyloxalamide possesses a stable conjugated structure within the polypropylene system, and its hydroxyl groups can form hydrogen bonds. These two factors work together to stabilize polypropylene segments and enhance nucleation ability. Furthermore, the side chains of N,N'-dinaphthyloxalamide contain conjugated π bonds, which not only stabilize polypropylene segments but also provide nucleation sites for crystallization. The hydroxyl functional groups can form hydrogen bonds in the amorphous phase, thus promoting the stability of the spherulites formed in polypropylene. The resulting β-crystal modified polypropylene exhibits a hexagonal spherical crystal structure, enhancing tensile strength and maintaining good toughness even at ambient temperatures as low as -20°C. Since the β-crystal is a thermodynamically metastable crystal form, while the α-crystal has better thermodynamic stability, under normal circumstances, the β-crystal will gradually transform into the α-crystal form.

[0044] The silanol and magnesium hydroxyl groups on the surface of talc undergo esterification and acid-base reactions with the carboxyl groups of maleic anhydride, forming a talc-maleic anhydride graft on the modified talc surface. The olefin chains of maleic anhydride become entangled with the modified polypropylene molecular chains, preventing chain movement and thus hindering the transformation of the modified polypropylene from the β-phase to the α-phase. The silanol of γ-aminopropyltriethoxysilane combines with the silanol groups on the surface of the modified talc to form a composite structure of silane-terminal talc-maleic anhydride graft-modified polypropylene molecular chains. This structure completely covers the α-phase nucleation sites of the modified talc, further strengthening the inhibitory effect of the modified talc on the transformation of the modified polypropylene from the β-phase to the α-phase.

[0045] Furthermore, the method for preparing the modified polypropylene includes the following steps:

[0046] S11. Polypropylene granules, N,N'-dinaphthyloxalamide, antioxidant 1010 and calcium stearate are premixed in a high-speed mixer for 1 to 1.5 hours to obtain a premix.

[0047] S12. Transfer the premix to a twin-screw extruder, melt-blend for 3 hours at a temperature of 180~220℃, and then extrude and granulate to obtain modified polypropylene.

[0048] Furthermore, the premixed raw materials are composed of the following weight ratios: 92-95 parts polypropylene particles, 0.4-0.5 parts N,N'-dinaphthyloxalamide, 0.2 parts antioxidant 1010, and 0.1 parts calcium stearate.

[0049] Furthermore, the preparation method of the modified talc powder includes the following steps:

[0050] S21. Dry the talc powder in a constant temperature drying oven at 105℃ for 1.5~2h to obtain talc powder without adsorbed water;

[0051] S22. Talc powder without adsorbed water, maleic anhydride, and dicumyl peroxide are premixed in a high-speed mixer for 10-15 minutes to obtain a mixture;

[0052] S23. Transfer the mixture to a twin-screw extruder and react it at a temperature of 160~180℃ for 5~10 min. After cooling, crush it with a pulverizer and sieve it to obtain modified talc powder.

[0053] Further, the raw materials in the mixture are configured in the following weight ratio: 100-110 parts talc, 1-5 parts maleic anhydride, and 0.1-0.5 parts dicumyl peroxide.

[0054] On the other hand, based on the same inventive concept, the present invention also provides a method for preparing a high-temperature resistant food packaging film, which is applied to the aforementioned high-temperature resistant food packaging film, comprising the following steps:

[0055] S31. Preparation of modified polypropylene;

[0056] S32. Preparation of modified talc powder;

[0057] S33. Modified polypropylene, modified talc, γ-aminopropyltriethoxysilane, and erucamide are fed into a twin-screw extruder, melt-blended for 3 hours, extruded through a ring die, and shaped by a cooling air ring to obtain a high-temperature resistant food packaging film.

[0058] Furthermore, the temperature conditions for the melt blending are 180~200℃.

[0059] Furthermore, the control conditions for extrusion through the annular die are a blow-up ratio (BUR) of 2~4:1 and a traction rate of 10~15m / min.

[0060] It should be noted that the surface of β-crystalline modified polypropylene is relatively rough. During processing, erucamide will migrate to the surface of modified polypropylene to form a monomolecular lubricating layer, which improves the smoothness of the film.

[0061] Example 2

[0062] This embodiment discloses a high-temperature resistant food packaging film. The raw materials include, by weight, 300 parts of modified polypropylene, 30 parts of modified talc, 0.9 parts of γ-aminopropyltriethoxysilane, and 0.9 parts of erucamide. The modified polypropylene has a β-crystal form with a hexagonal spherical crystal structure.

[0063] The preparation methods of the modified polypropylene and modified talc in this embodiment are the same as those in Example 1. The preparation method of the high-temperature resistant food packaging film in this embodiment is also the same as that in Example 1.

[0064] Example 3

[0065] This embodiment discloses a high-temperature resistant food packaging film. The raw materials, by weight, include: 250 parts of modified polypropylene, 25 parts of modified talc, 0.5 parts of γ-aminopropyltriethoxysilane, and 0.5 parts of erucamide; the modified polypropylene has a β-crystal form with a hexagonal spherical crystal structure.

[0066] The preparation methods of the modified polypropylene and modified talc in this embodiment are the same as those in Example 1. The preparation method of the high-temperature resistant food packaging film in this embodiment is also the same as that in Example 1.

[0067] Example 4

[0068] This embodiment discloses a high-temperature resistant food packaging film. The raw materials include, by weight, 199 parts of modified polypropylene, 19 parts of modified talc, 0.1 parts of γ-aminopropyltriethoxysilane, and 0.1 parts of erucamide. The modified polypropylene has a β-crystal form with a hexagonal spherical crystal structure.

[0069] The preparation methods of the modified polypropylene and modified talc in this embodiment are the same as those in Example 1. The preparation method of the high-temperature resistant food packaging film in this embodiment is also the same as that in Example 1.

[0070] Example 5

[0071] The difference between this embodiment and Example 1 is that N,N'-dinaphthyloxalamide is not added when preparing the modified polypropylene.

[0072] This embodiment discloses a high-temperature resistant food packaging film. The raw materials, by weight, include: 200 parts of modified polypropylene, 20 parts of modified talc, 0.2 parts of γ-aminopropyltriethoxysilane, and 0.2 parts of erucamide. The modified polypropylene has a β-crystal form with a hexagonal spherical crystal structure.

[0073] Furthermore, the method for preparing the modified polypropylene includes the following steps:

[0074] S11. Polypropylene granules, antioxidant 1010 and calcium stearate are premixed in a high-speed mixer for 1 to 1.5 hours to obtain a premix.

[0075] S12. Transfer the premix to a twin-screw extruder, melt-blend for 3 hours at a temperature of 180~220℃, and then extrude and granulate to obtain modified polypropylene.

[0076] Furthermore, the premixed raw materials are composed of the following weight ratio: 92-95 parts polypropylene granules, 0.2 parts antioxidant, and 0.1 parts calcium stearate.

[0077] The preparation method of the modified talc powder in this embodiment is the same as that in Example 1. The preparation method of the high-temperature resistant food packaging film in this embodiment is the same as that in Example 1.

[0078] Example 6

[0079] The difference between this embodiment and Embodiment 1 is that maleic anhydride is not added when preparing the modified talc powder.

[0080] This embodiment discloses a high-temperature resistant food packaging film. The raw materials, by weight, include: 200 parts of modified polypropylene, 20 parts of modified talc, 0.2 parts of γ-aminopropyltriethoxysilane, and 0.2 parts of erucamide. The modified polypropylene has a β-crystal form with a hexagonal spherical crystal structure.

[0081] Furthermore, the preparation method of the modified talc powder includes the following steps:

[0082] S21. Dry the talc powder in a constant temperature drying oven at 105℃ for 1.5~2h to obtain talc powder without adsorbed water;

[0083] S22. Talc powder and dicumyl peroxide without adsorbed water are premixed in a high-speed mixer for 10-15 minutes to obtain a mixture;

[0084] S23. Transfer the mixture to a twin-screw extruder and react it at a temperature of 160~180℃ for 5~10 min. After cooling, crush it with a pulverizer and sieve it to obtain modified talc powder.

[0085] Furthermore, the raw materials in the mixture are configured in the following weight ratio: 100-110 parts talc and 0.1-0.5 parts dicumyl peroxide.

[0086] The preparation method of the modified polypropylene in this embodiment is the same as that in Example 1. The preparation method of the high-temperature resistant food packaging film in this embodiment is the same as that in Example 1.

[0087] Comparative Example 1

[0088] The difference between this comparative example and Example 1 is that it does not contain modified polypropylene.

[0089] This comparative example discloses a high-temperature resistant food packaging film, the raw materials of which include, by weight: 20 parts modified talc, 0.2 parts γ-aminopropyltriethoxysilane, and 0.2 parts erucamide.

[0090] The preparation method of the modified talc powder in this comparative example is the same as that in Example 1. The preparation method of the high-temperature resistant food packaging film in this comparative example is the same as that in Example 1.

[0091] Comparative Example 2

[0092] The difference between this comparative example and Example 1 is that it does not contain modified talc.

[0093] This comparative example discloses a high-temperature resistant food packaging film, the raw materials of which include, by weight: 200 parts of modified polypropylene, 0.2 parts of γ-aminopropyltriethoxysilane, and 0.2 parts of erucamide; the modified polypropylene has a β-crystal form with a hexagonal spherical crystal structure.

[0094] The preparation method of the modified polypropylene in this comparative example is the same as that in Example 1. The preparation method of the high-temperature resistant food packaging film in this comparative example is the same as that in Example 1.

[0095] Comparative Example 3

[0096] The difference between this comparative example and Example 1 is that it does not contain γ-aminopropyltriethoxysilane.

[0097] This comparative example discloses a high-temperature resistant food packaging film, the raw materials of which include, by weight: 200 parts modified polypropylene, 20 parts modified talc, and 0.2 parts erucamide; the modified polypropylene has a β-crystal form with a hexagonal spherical crystal structure.

[0098] The preparation methods of the modified polypropylene and modified talc in this comparative example are the same as those in Example 1. The preparation method of the high-temperature resistant food packaging film in this comparative example is the same as that in Example 1.

[0099] Experimental Example 1

[0100] The polypropylene β crystal content of the high-temperature resistant food packaging films prepared in Examples 1-6 and Comparative Examples 1-3 was detected at 0h, 24h, and 72h, respectively. The detection results are shown in Table 1.

[0101] Table 1. Detection of polypropylene β-crystal content in food packaging film

[0102] 0h 24h 72h Example 1 78~82% 78~82% 74~80% Example 2 78~81% 78~80% 75~80% Example 3 83~85% 83~85% 81~83% Example 4 70~75% 70~74% 69~74% Example 5 10~15% 5~8% 5~7% Example 6 70~73% 65~70% 63~67% Comparative Example 1 0% 0% 0% Comparative Example 2 65~69% 55~60% 40~45% Comparative Example 3 70~73% 65~70% 62~65%

[0103] Experimental Example 2

[0104] The high-temperature resistant food packaging films prepared in Examples 1-6 and Comparative Examples 2-3 were placed at -20°C and the elongation at break was tested after 0h, 24h, and 72h. The testing method is existing technology and will not be described in detail here. The test results are shown in Table 2.

[0105] Table 2. Detection of Elongation at Break of Food Packaging Film

[0106] 0h 24h 72h Example 1 440~480% 440~480% 440~480% Example 2 440~480% 430~470% 430~470% Example 3 450~500% 450~500% 450~500% Example 4 400~450% 400~440% 400~440% Example 5 100~150% 50~80% 50~70% Example 6 400~450% 390~430% 380~420% Comparative Example 2 380~420% 350~400% 250~300% Comparative Example 3 420~450% 400~440% 380~420%

[0107] Based on the data in Tables 1 and 2, Example 3 of this invention represents the optimal formulation, maintaining a balanced content of polypropylene β crystals and exhibiting good toughness at -20°C. Comparing Comparative Example 2 and Example 1, the addition of modified talc in this invention does indeed hinder the transformation of modified polypropylene from the β-crystal form to the α-crystal form. Comparing Comparative Example 3 and Example 1, the γ-aminopropyltriethoxysilane of this invention further hinders the transformation of modified polypropylene from the β-crystal form to the α-crystal form.

[0108] Finally, it should be noted that although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high temperature resistant food packaging film, characterized by, The raw materials, by weight, include: 200-300 parts modified polypropylene, 20-30 parts modified talc, 0.2-0.9 parts γ-aminopropyltriethoxysilane, and 0.2-0.9 parts erucamide; The modified polypropylene has a β-crystal form with a hexagonal spherical crystal structure. The modified polypropylene is obtained by physical blending polypropylene with N,N'-dinaphthyloxalamide. The rigid benzene ring structure of N,N'-dinaphthyloxalamide serves as a heterogeneous nucleation site, promoting the orderly arrangement of polypropylene molecular chains and improving the crystallinity of β crystals. The method for preparing the modified polypropylene includes the following steps: S11. Polypropylene granules, N,N'-dinaphthyloxalamide, antioxidant 1010 and calcium stearate are premixed in a high-speed mixer for 1 to 1.5 hours to obtain a premix. S12. The premix is ​​transferred to a twin-screw extruder and melt-blended for 3 hours at a temperature of 180~220℃. The mixture is then extruded and granulated to obtain modified polypropylene. The preparation method of the modified talc powder includes the following steps: S21. Dry the talc powder in a constant temperature drying oven at 105℃ for 1.5~2h to obtain talc powder without adsorbed water; S22. Talc powder without adsorbed water, maleic anhydride, and dicumyl peroxide are premixed in a high-speed mixer for 10-15 minutes to obtain a mixture; S23. Transfer the mixture to a twin-screw extruder and react it at a temperature of 160~180℃ for 5~10 min. After cooling, pulverize it with a pulverizer and sieve it to obtain modified talc powder. The premixed material has the following weight ratio: 92-95 parts polypropylene granules, 0.4-0.5 parts N,N'-dinaphthyloxalamide, 0.2 parts antioxidant 1010, and 0.1 parts calcium stearate; The mixture consists of the following raw materials in the following weight ratio: 100-110 parts talc, 1-5 parts maleic anhydride, and 0.1-0.5 parts dicumyl peroxide.

2. A method for preparing a high-temperature resistant food packaging film, applied to prepare the high-temperature resistant food packaging film according to any one of claims 1, characterized in that, The method includes the following steps: S31. Preparation of modified polypropylene; S32. Preparation of modified talc powder; S33. Modified polypropylene, modified talc, γ-aminopropyltriethoxysilane, and erucamide are fed into a twin-screw extruder, melt-blended for 3 hours, extruded through a ring die, and shaped by a cooling air ring to obtain a high-temperature resistant food packaging film.

3. The method for preparing a high-temperature resistant food packaging film according to claim 2, characterized in that, The temperature conditions for melt blending are 180~200℃.

4. The method for preparing a high-temperature resistant food packaging film according to claim 2, characterized in that, The control conditions for extrusion through the annular die are a blow-up ratio (BUR) of 2 to 4:1 and a traction speed of 10 to 15 m / min.

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