An anti-adhesion polyamide film and its preparation method

Abstract

This invention belongs to the field of flexible packaging materials technology, specifically relating to an anti-adhesion polyamide film and its preparation method. The anti-adhesion polyamide film comprises a three-layer structure, consisting of an anti-adhesion layer, a core layer, and a corona layer from the outside in. The anti-adhesion layer comprises 5%–8% polybutylene succinate resin, 10%–15% functional masterbatch, and 77%–85% copolymer polyamide resin. The core layer comprises 100% polyamide 6 resin, and the corona layer comprises 97%–99% polyamide 6 resin and 3%–5% anti-adhesion masterbatch. This invention utilizes the crystallization property of polybutylene succinate resin and the ability of silica to accelerate crystallization in the molten state of the polymer, refining the grain structure. By combining these properties, micro-nano protrusions are formed on the surface of the anti-adhesion layer, creating a lotus leaf-like effect. Simultaneously, the synergistic effect of the amide silicone resin ultimately reduces the surface energy of the polyamide, thereby achieving the anti-adhesion effect.

Description

Technical Field

[0001] This invention belongs to the field of flexible packaging materials technology, specifically relating to an anti-adhesion polyamide film and its preparation method. Background Technology

[0002] Spout stand-up pouches are a stylish new type of packaging bag, commonly used for packaging fruit juices, beverages, sauces, and other foods. They boast a high-end, sophisticated, and novel appearance, offering excellent shelf display. They are easy to use; simply twist the spout cap to open, and close the cap after use for convenient storage. The materials used in spout pouches are more environmentally friendly than those in conventional bottles or containers. Data shows that compared to bottles of the same capacity, spout pouches reduce raw material consumption by over 30%, packaging material storage and transportation costs by over 60%, and overall waste disposal volume by up to 5 times. Furthermore, they are cleaner and more hygienic than ordinary stand-up pouches.

[0003] The body of spout stand-up pouches is often made of polyamide because polyamide makes the bag body softer and more flexible, and the polyamide layer can protect the aluminum foil layer, making the bag less likely to break, especially for large-capacity packaging. Choosing polyamide as the bottom layer as the middle layer can ensure the pressure resistance of the packaging bag. If the sterilization method of the spout pouch is high-temperature retort, then polyamide material is even more necessary because polyamide is more heat-resistant.

[0004] Polyamide is a polar material with good affinity. Untreated polyamide films have low surface tension, which can easily lead to sticky food residue and affect product quality. If sticky foods such as ketchup, sauces, honey, and cheese adhere to the surface of polyamide packaging, they are not easy to wipe off, which not only affects the appearance of the product, but also causes mold and other quality problems if sauces are left on the packaging surface for a long time. Summary of the Invention

[0005] To address the problem of low surface tension in polyamide films in the prior art, which easily leads to sticky food residue, this invention provides an anti-adhesion polyamide film and its preparation method, wherein the film structure consists of an anti-adhesion layer, a core layer, and a corona layer from the outside to the inside.

[0006] The anti-adhesion layer comprises polybutylene succinate resin, functional masterbatch, and copolyamide resin.

[0007] The functional masterbatch comprises the following components by weight percentage: 3%–15% amide silicone resin, 1%–5% silica and 80%–94% copolyamide resin;

[0008] The mass ratio of polybutylene succinate resin to functional masterbatch is 5-8:10-15.

[0009] The core layer is composed of 100% polyamide 6 resin;

[0010] The corona layer comprises 95%–97% polyamide 6 resin and 3%–5% anti-sticking masterbatch.

[0011] The anti-stick masterbatch comprises the following components by weight percentage: 1%–5% opening agent, 1%–5% slip agent and 90%–98% polyamide 6 resin.

[0012] In one embodiment, the anti-adhesion layer component comprises, by weight percentage, 5%–8% polybutylene succinate resin, 10%–15% functional masterbatch, and 77%–85% copolyamide resin.

[0013] In one embodiment, the amide silicone resin is a silicone resin modified with amide anchoring groups;

[0014] Its chemical formula is: CH3(CH2) n CONH(R2SiO) m NHCO(CH2) n CH3, where n is 6 to 16, R is CH3, and the molecular weight is 10,000 to 100,000.

[0015] In one embodiment, the silica is porous, with a porosity of 1.5 to 3.0 ml / g.

[0016] In one embodiment, the copolymer polyamide resin is copolymerized from at least two monomers selected from polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 1010, polyamide 1212 and polyamide MXD6.

[0017] In one embodiment, the melting point of the copolyamide is between 160 and 190 °C.

[0018] In one embodiment, the opening agent is one or more of talc, calcium carbonate, and acrylic; the slip agent is one or more of erucamide, oleamide, ethylene bis-stearamide, polyethylene wax, and polypropylene wax.

[0019] In one embodiment, the thickness of the anti-adhesion layer is 2–5 μm; the thickness of the core layer is 10–60 μm; and the thickness of the corona layer is 1–2 μm.

[0020] The present invention also provides a method for preparing the anti-adhesion polyamide film as described above, the steps of which are as follows:

[0021] Preparation of S100 and functional masterbatches:

[0022] Step 1: Pour silica into a mixing tank equipped with a stirring device, and continuously drip amide silicone resin into the mixing tank at multiple locations to mix thoroughly and form a powdery mixture.

[0023] Step 2: Using a precise loss-in-weight scale, the copolyamide and powder mixture are fed into the pellets according to the specified ratio, melt-blended by a twin-screw extruder, filtered through a screen, extruded through a die, and then water-cooled and pelletized.

[0024] Preparation of S200 and anti-sticking masterbatch:

[0025] Polyamide 6 resin, opening agent and slip agent are fed into the material in proportion using a precise loss-in-weight scale, melt-blended by a twin-screw extruder, filtered, extruded through a die, and then water-cooled and pelletized.

[0026] Preparation of S300 polyamide films:

[0027] Step 1: The copolyamide resin and functional masterbatch of the anti-adhesion layer, the polyamide 6 resin of the core layer, the polyamide 6 resin and anti-adhesion masterbatch of the corona layer are fed in proportion by a feeder and melted through their respective extruders. After being uniformly discharged through a T-die, they are cooled on a quenching roller to form an unstretched sheet.

[0028] The temperature of the cold roller is 25–55℃; the thickness of the unstretched sheet is 150–500μm.

[0029] Step 2: After washing the unstretched sheet with water to remove small molecules and plasticize it, stretch it in stages under heating.

[0030] The longitudinal stretching temperature is 45–65℃, and the stretching ratio is 2.8–3.5 times; the transverse stretching temperature is 75–85℃, and the stretching ratio is 3.0–3.5 times.

[0031] Step 3: Heat set the stretched film to obtain a polyamide film;

[0032] The setting temperature is 160–220℃, and the setting time is 40–120 seconds.

[0033] Step 4: Perform corona treatment on the heat-set corona layer, then roll it up and slit it to obtain an anti-adhesion polyamide film.

[0034] In one embodiment, the surface tension of the polyamide film after corona treatment is 50–54 dny.

[0035] Based on the above, compared with the prior art, the beneficial effects of the present invention are as follows:

[0036] In the anti-adhesion layer of this invention, polybutylene succinate resin has the property of crystallization. Silica can provide the required crystal nuclei in the polymer molten state, causing the polymer to change from homogeneous nucleation to heterogeneous nucleation, thereby accelerating the crystallization rate and refining the grain structure. Silica also has the function of adsorbing amide silicone resin. This invention combines the properties of both to form micro-nano protrusions on the surface of the anti-adhesion layer, creating a lotus leaf-like effect. At the same time, the amide silicone resin synergistically reduces the surface energy of the polyamide, thereby achieving the anti-adhesion effect.

[0037] In the preferred embodiment, the amide silicone resin is a silicone wax powder modified with amide anchoring groups to prevent excessive migration of the amide silicone resin, which would affect the ink printing and adhesive bonding strength of the corona-treated surface.

[0038] In the preferred embodiment, the melting point of the copolyamide resin is controlled at 160-190°C. This is to prevent the melt index of polybutylene succinate resin from decreasing significantly due to high-temperature processing, and to reduce the polarity of the polyamide material, thereby improving its compatibility with silicone.

[0039] In a preferred embodiment, the surface tension of the polyamide film is adjusted to 50–54 dny by corona treatment to improve its compatibility with inks, coatings or other materials.

[0040] The anti-adhesion polyamide film provided by this invention has good mechanical properties, optical properties and barrier properties. At the same time, the anti-adhesion layer has low surface adhesion, which can solve the problem of sticky foods such as tomato sauce, syrup, honey and cheese sticking to the packaging surface, avoiding consumer inconvenience and food waste.

[0041] Other features and beneficial effects of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other beneficial effects of the invention can be realized and obtained by means of the structures particularly pointed out in the description, claims and drawings. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Unless otherwise specified, the positional relationships shown in the drawings in the following description are based on the direction in which the components are drawn in the figure.

[0043] Figure 1 This is a schematic diagram of the structure of an embodiment of the anti-adhesion polyamide film layer provided by the present invention.

[0044] Figure label:

[0045] Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, not all embodiments. The technical features designed in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0047] In the description of this invention, it should be noted that all terms used in this invention (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains, and should not be construed as limiting the invention; it should be further understood that the terms used in this invention should be understood to have the same meaning as those in the context of this specification and in the relevant field, and should not be understood in an idealized or overly formal sense, except as expressly defined in this invention.

[0048] The present invention also provides the following embodiments and comparative examples:

[0049] Example 1

[0050] The anti-adhesion layer 100 components by mass percentage are: 6% polybutylene succinate, 12% functional masterbatch, and 82% copolyamide 6 / 12;

[0051] The core layer 200 component by mass percentage is: 100% polyamide 6 resin;

[0052] The corona layer 300 has the following components by mass percentage: 4% anti-sticking masterbatch and 96% polyamide 6 resin.

[0053] The functional masterbatch components are as follows by mass percentage: 9% amide silicone resin, 3% silica, and 88% copolyamide 6 / 12 resin.

[0054] The anti-sticking masterbatch components are: 3% talc, 3% ethylene bis-stearamide, and 94% polyamide 6 resin by mass percentage.

[0055] The anti-adhesion layer has a thickness of 3.3μm.

[0056] The core layer 200 has a thickness of 20.0 μm.

[0057] The corona layer 300 has a thickness of 1.7 μm.

[0058] Example 2

[0059] The anti-adhesion layer has the following components by mass percentage: 8% polybutylene succinate, 15% functional masterbatch, and 77% copolyamide 6 / 12 resin.

[0060] The core layer 200 component by mass percentage is: 100% polyamide 6 resin;

[0061] The corona layer 300 has the following composition by mass percentage: 5% anti-sticking masterbatch and 95% polyamide 6 resin.

[0062] The functional masterbatch components are as follows by mass percentage: 15% amide silicone resin, 5% silica, and 80% copolyamide 6 / 12 resin.

[0063] The anti-sticking masterbatch components are: 5% talc, 5% ethylene bis-stearamide, and 90% polyamide 6 resin by mass percentage.

[0064] The anti-adhesion layer has a thickness of 5μm.

[0065] The core layer 200 has a thickness of 18.3 μm.

[0066] The corona layer 300 has a thickness of 1.7 μm.

[0067] Example 3

[0068] The anti-adhesion layer has the following components by mass percentage: 5% polybutylene succinate, 10% functional masterbatch, and 85% copolyamide 6 / 12 resin.

[0069] The core layer 200 component by mass percentage is: 100% polyamide 6 resin;

[0070] The corona layer 300 has the following composition by mass percentage: 3% anti-sticking masterbatch and 97% polyamide 6 resin.

[0071] The functional masterbatch components are as follows by mass percentage: 3% amide silicone resin, 1% silica, and 96% copolyamide 6 / 12 resin.

[0072] The anti-sticking masterbatch components are: 1% talc, 1% ethylene bis-stearamide, and 98% polyamide 6 resin by mass percentage.

[0073] The anti-adhesion layer has a thickness of 2.0 μm.

[0074] The core layer 200 has a thickness of 21.3 μm.

[0075] The corona layer 300 has a thickness of 1.7 μm.

[0076] Example 4

[0077] The difference between Example 4 and Example 1 is that in Example 4, the copolyamide 6 / 12 resin in Example 1 is replaced with copolyamide 10 / 12 resin, and the talc in the anti-sticking masterbatch component is replaced with calcium carbonate. All other aspects are the same as in Example 1.

[0078] The anti-adhesion layer 100 components by mass percentage are: 6% polybutylene succinate, 12% functional masterbatch, and 82% copolyamide 10 / 12 resin.

[0079] The core layer 200 component by mass percentage is: 100% polyamide 6 resin;

[0080] The corona layer 300 has the following composition by mass percentage: 4% anti-sticking masterbatch and 96% polyamide 6 resin.

[0081] The functional masterbatch components are as follows by mass percentage: 9% amide silicone resin, 3% silica, and 88% copolyamide 10 / 12 resin.

[0082] The anti-sticking masterbatch components are: 3% calcium carbonate, 3% ethylene bis-stearamide, and 94% polyamide 6 resin by mass percentage.

[0083] The anti-adhesion layer has a thickness of 3.3μm.

[0084] The core layer 200 has a thickness of 20.0 μm.

[0085] The corona layer 300 has a thickness of 1.7 μm.

[0086] Comparative Example 1

[0087] The difference between Comparative Example 1 and Example 1 is that: Comparative Example 1 did not add polybutylene succinate, replaced the copolyamide 6 / 12 resin with polyamide 6 resin, and replaced the ethylene bis-stearamide in the anti-sticking masterbatch component with erucamide. All other aspects were the same as in Example 1.

[0088] The anti-adhesion layer consists of the following components by mass percentage: 4% functional masterbatch and 96% polyamide 6 resin.

[0089] The core layer 200 component by mass percentage is: 100% polyamide 6 resin;

[0090] The corona layer 300 has the following components by mass percentage: 4% anti-sticking masterbatch and 96% polyamide 6 resin.

[0091] The functional masterbatch components are as follows by mass percentage: 9% amide silicone resin, 3% silica, and 88% copolyamide 6 / 12 resin.

[0092] The anti-sticking masterbatch components are: 3% talc, 3% erucamide, and 94% polyamide 6 resin by mass percentage.

[0093] The anti-adhesion layer has a thickness of 3.3μm.

[0094] The core layer 200 has a thickness of 20.0 μm.

[0095] The corona layer 300 has a thickness of 1.7 μm.

[0096] Comparative Example 2

[0097] The difference between Comparative Example 2 and Example 1 is that no functional masterbatch was added in Comparative Example 2, and the copolyamide 6 / 12 resin was replaced with polyamide 6 resin. All other aspects are the same as in Example 1.

[0098] The anti-adhesion layer 100 has the following components by mass percentage: 6% polybutylene succinate and 94% polyamide 6 resin.

[0099] The core layer 200 component by mass percentage is: 100% polyamide 6 resin;

[0100] The corona layer 300 has the following components by mass percentage: 4% anti-sticking masterbatch and 96% polyamide 6 resin.

[0101] The anti-sticking masterbatch components are: 3% talc, 3% ethylene bis-stearamide, and 94% polyamide 6 resin by mass percentage.

[0102] The anti-adhesion layer has a thickness of 3.3μm.

[0103] The core layer 200 has a thickness of 20.0 μm.

[0104] The corona layer 300 has a thickness of 1.7 μm.

[0105] Comparative Example 3

[0106] The difference between Comparative Example 3 and Example 1 is that: Comparative Example 3 did not add polybutylene succinate, replaced the copolymer polyamide 6 / 12 resin with polyamide 6 resin, and replaced the amide silicone resin in the functional masterbatch of Example 1 with methyl silicone wax. All other aspects are the same as in Example 1.

[0107] The anti-adhesion layer has the following components by mass percentage: 12% functional masterbatch and 88% polyamide 6 resin.

[0108] The core layer 200 component by mass percentage is: 100% polyamide 6 resin;

[0109] The corona layer 300 has the following components by mass percentage: 4% anti-sticking masterbatch and 96% polyamide 6 resin.

[0110] The functional masterbatch components by mass percentage are: 9% methyl silicone wax, 3% silica, and 88% polyamide 6 resin;

[0111] The anti-sticking masterbatch components are: 3% talc, 3% ethylene bis-stearamide, and 94% polyamide 6 resin by mass percentage.

[0112] The anti-adhesion layer 100 has a thickness of 3.3 μm.

[0113] The core layer 200 has a thickness of 20.0 μm.

[0114] The corona layer 300 has a thickness of 1.7 μm.

[0115] Comparative Example 4

[0116] The difference between Comparative Example 4 and Example 1 is that Comparative Example 4 did not contain polybutylene succinate, while all other aspects were the same as in Example 1.

[0117] Comparative Example 5

[0118] The difference between Comparative Example 5 and Example 1 is that no functional masterbatch was added to Comparative Example 5, while everything else is the same as Example 1.

[0119] Comparative Example 6

[0120] The difference between Comparative Example 6 and Example 1 is that the copolyamide 6 / 12 resin in Comparative Example 6 is replaced with polyamide 6 resin, while the rest is the same as in Example 1.

[0121] Comparative Example 7

[0122] The difference between Comparative Example 7 and Example 1 is that Comparative Example 7 did not add silicon dioxide to the functional masterbatch components, while the rest were the same as Example 1.

[0123] Examples 1-4 and Comparative Examples 1-7 were all prepared using the following steps:

[0124] Preparation of S100 and functional masterbatches:

[0125] Step 1: Pour silica into a mixing tank equipped with a stirring device, and continuously drip amide silicone resin into the mixing tank at multiple locations to mix thoroughly and form a powdery mixture.

[0126] Step 2: Using a precise loss-in-weight scale, the copolyamide and powder mixture are fed into the pellets according to the specified ratio, melt-blended by a twin-screw extruder, filtered, extruded through a die, and then water-cooled and pelletized.

[0127] Preparation of S200 and anti-sticking masterbatch:

[0128] Polyamide 6 resin, opening agent and slip agent are fed into the material in proportion using a precise loss-in-weight scale, melt-blended by a twin-screw extruder, filtered, extruded through a die, and then water-cooled and pelletized.

[0129] Preparation of S300 polyamide films:

[0130] Step 1: The copolyamide resin and functional masterbatch of the anti-adhesion layer, the polyamide 6 resin of the core layer, the polyamide 6 resin and anti-adhesion masterbatch of the corona layer are fed in proportion by a feeder and melted through their respective extruders. After being uniformly discharged through a T-die, they are cooled on a quenching roller to form an unstretched sheet.

[0131] The temperature of the cold roller is 25–55℃; the thickness of the unstretched sheet is 150–500μm.

[0132] Step 2: After washing the unstretched sheet with water to remove small molecules and plasticize it, stretch it in stages under heating.

[0133] The longitudinal stretching temperature is 45–65℃, and the stretching ratio is 2.8–3.5 times; the transverse stretching temperature is 75–85℃, and the stretching ratio is 3.0–3.5 times.

[0134] Step 3: Heat set the stretched film to obtain a polyamide film;

[0135] The setting temperature is 160–220℃, and the setting time is 40–120 seconds.

[0136] Step 4: Perform corona treatment on the heat-set corona layer to make its surface tension 50-54 dny, and then roll it up and slit it to obtain an anti-adhesion polyamide film.

[0137] Various performance tests were conducted on each embodiment and comparative example, and the test standards are as follows:

[0138] Thickness: GB / T20220-2006 Average thickness of plastic film and sheet samples, average thickness of rolls and surface area per unit mass;

[0139] Surface tension: The surface tension of the thin film was tested according to GB / T 14216-2008;

[0140] Moisture absorption elongation: The initial size of the film is L0. After being placed in an environment of 23℃ / 55% humidity for 48 hours, the size is L1. The rate of no change in film size is measured as: [(L1-L0) / L0]*100%;

[0141] Heat shrinkage rate: GB / T12027-2004 Test method for dimensional change rate of plastic films and sheets upon heating;

[0142] Tensile strength and elongation at break: Tested according to GB / T1040.3-2006 "Determination of tensile properties of plastic films" Part 3: Test conditions for films and sheets.

[0143] The performance test results of each embodiment and comparative example are shown in Table 1.

[0144] Table 1 Performance Test Results

[0145]

[0146] The surface tension of the adhesive surface of a polyamide film is a parameter that measures the surface free energy of a material. It determines the wettability of the surface and thus affects adhesion performance. High surface tension generally means high surface energy, making such surfaces more likely to adhere to other substances. Conversely, low surface tension reduces adhesion because they have lower free energy and are less likely to interact with other substances.

[0147] As can be seen from Table 1, the surface tension of the adhesive surfaces of the polyamide films prepared in Examples 1-4 is much lower than that in Comparative Examples 1-7, indicating that the anti-adhesion effect of Examples 1-4 is significantly higher than that of Comparative Examples 1-7. Although the anti-adhesion surface of the polyamide film in Comparative Example 3 has a lower surface tension, the corona decay of Comparative Example 3 is severe after curing, which will affect the printing and lamination effect of the film.

[0148] Moisture absorption elongation refers to the percentage increase in size of a material after absorbing moisture, and it is an important parameter for measuring the dimensional stability of a material in a humid environment. The polyamide films of Examples 1-4 have lower moisture absorption elongation than those of Comparative Examples 1-3, indicating that the polyamide films of Examples 1-4 have higher reliability and stability in practical applications.

[0149] Tensile strength and elongation at break are two important indicators for evaluating the mechanical properties of materials. Tensile strength refers to the maximum stress a material can withstand under tensile force without breaking. Elongation at break is the ratio of the elongation at break to the original length of the material. The polyamide films of Examples 1-4 exhibit higher tensile strength and elongation at break than those of Comparative Examples 1-3, indicating that the polyamide films of Examples 1-4 possess good flexibility and extensibility, while also being able to withstand greater mechanical forces, thus providing better protection for spout stand-up pouches.

[0150] In summary, compared with the prior art, the anti-adhesion polyamide film provided by the present invention, while possessing excellent anti-adhesion properties, also has good moisture absorption elongation, tensile strength and elongation at break, and excellent mechanical properties, thus expanding the application range of polyamide films and having high application value.

[0151] Furthermore, those skilled in the art should understand that although many problems exist in the prior art, each embodiment or technical solution of the present invention can be improved in only one or a few aspects, without necessarily solving all the technical problems listed in the prior art or the background art simultaneously. Those skilled in the art should understand that any content not mentioned in a claim should not be construed as a limitation on that claim.

[0152] Although this document frequently uses terms such as anti-adhesion layer, core layer, and corona layer, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention. The terms "first," "second," etc. (if present) in the specification, claims, and accompanying drawings of the embodiments of the invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0153] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions 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 polyamide film for preventing adhesion, characterized in that: Its membrane structure, from the outside to the inside, consists of an anti-adhesion layer, a core layer, and a corona layer. The anti-adhesion layer comprises polybutylene succinate resin, functional masterbatch, and copolyamide resin. The functional masterbatch comprises the following components by weight percentage: 3%–15% amide silicone resin, 1%–5% silica and 80%–94% copolyamide resin; The mass ratio of polybutylene succinate resin to functional masterbatch is 5-8:10-15. The core layer is composed of 100% polyamide 6 resin; The corona layer comprises 95%–97% polyamide 6 resin and 3%–5% anti-sticking masterbatch. The anti-sticking masterbatch comprises the following components by weight percentage: 1%–5% opening agent, 1%–5% slip agent and 90%–98% polyamide 6 resin; The amide silicone resin is a silicone resin modified with amide anchoring groups; Its chemical formula is: CH3(CH2) n CONH(R2SiO) m NHCO(CH2) n CH3, where n is 6 to 16, R is CH3, and the molecular weight is 10,000 to 100,000.

2. The anti-adhesion polyamide film according to claim 1, characterized in that: The anti-adhesion layer components, by weight percentage, comprise 5%–8% polybutylene succinate resin, 10%–15% functional masterbatch, and 77%–85% copolyamide resin.

3. The anti-adhesion polyamide film according to claim 1, characterized in that: The silica has pores with a porosity of 1.5 to 3.0 ml / g.

4. The anti-adhesion polyamide film according to claim 1, characterized in that: The copolymer polyamide resin is copolymerized from at least two monomers selected from polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 1010, polyamide 1212 and polyamide MXD6.

5. The anti-adhesion polyamide film according to claim 1, characterized in that: The melting point of the copolyamide is between 160 and 190 °C.

6. The anti-adhesion polyamide film according to claim 1, characterized in that: The opening agent is one or more of talc, calcium carbonate, and acrylic; the slip agent is one or more of erucamide, oleamide, ethylene bis-stearamide, polyethylene wax, and polypropylene wax.

7. The anti-adhesion polyamide film according to claim 1, characterized in that: The thickness of the anti-adhesion layer is 2-5 μm; the thickness of the core layer is 10-60 μm; and the thickness of the corona layer is 1-2 μm.

8. A method for preparing an anti-adhesion polyamide film as described in any one of claims 1 to 7, characterized in that, The steps are as follows: Preparation of S100 and functional masterbatches: Step 1: Pour silica into a mixing tank equipped with a stirring device, and continuously drip amide silicone resin into the mixing tank at multiple locations to mix thoroughly and form a powdery mixture. Step 2: Using a precise loss-in-weight scale, the copolyamide and powder mixture are fed into the pellets according to the specified ratio, melt-blended by a twin-screw extruder, filtered through a screen, extruded through a die, and then water-cooled and pelletized. Preparation of S200 and anti-sticking masterbatch: Polyamide 6 resin, opening agent and slip agent are fed into the material in proportion using a precise loss-in-weight scale, melt-blended by a twin-screw extruder, filtered, extruded through a die, and then water-cooled and pelletized. Preparation of S300 polyamide films: Step 1: The copolyamide resin and functional masterbatch of the anti-adhesion layer, the polyamide 6 resin of the core layer, the polyamide 6 resin and anti-adhesion masterbatch of the corona layer are fed in proportion by a feeder and melted through their respective extruders. After being uniformly discharged through a T-die, they are cooled on a quenching roller to form an unstretched sheet. Step 2: After washing the unstretched sheet with water to remove small molecules and plasticize it, stretch it in stages under heating. The longitudinal stretching temperature is 45–65℃, and the stretching ratio is 2.8–3.5 times; the transverse stretching temperature is 75–85℃, and the stretching ratio is 3.0–3.5 times. Step 3: Heat set the stretched film to obtain a polyamide film; The setting temperature is 160–220℃, and the setting time is 40–120 seconds. Step 4: Perform corona treatment on the heat-set polyamide film, then roll it up and slit it to obtain an anti-adhesion polyamide film.

9. The method for preparing the anti-adhesion polyamide film according to claim 8, characterized in that: The surface tension of the polyamide film after corona treatment is 50-54 dny.

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