High-toughness biaxially oriented nylon film and production method thereof

Abstract

The invention discloses a high-toughness biaxially oriented nylon film and a production method thereof. Comprising the following raw materials in parts by weight: 40-50 parts of copolymerized nylon resin, 10-20 parts of nylon 12, 15-25 parts of thermoplastic polyamide elastomer, 3-6 parts of nanofiller, 1-3 parts of coupling agent, 10-20 parts of reinforced fiber, 5-8 parts of additive, 3-7 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer and 6-10 parts of modified cellulose nanocrystal. The invention relates to a flame-retardant polyamide resin, which is prepared from the following components in parts by weight: 2-4 parts of amino-terminated hyperbranched polyamide and 1-3 parts of 3, 3 '-diamino-4, 4'-difluorodiphenyl sulfone. The film is high in tensile strength, good in tear resistance and excellent in barrier property and low-temperature impact resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of film materials, and particularly to a high-toughness biaxially oriented nylon film and a production method thereof. Background Art

[0002] The biaxially oriented nylon film has excellent puncture resistance, gas barrier property, pinhole resistance, transparency, printability, etc., and is therefore widely used in packaging fields such as food, medicine, cosmetics, and mechanical electronics. It is another major packaging material after BOPP and BOPET, and enjoys the reputation of the "queen" of films. However, the traditional biaxially oriented nylon film has certain limitations in terms of toughness and is difficult to meet some application scenarios with high requirements for material toughness.

[0003] Currently, the methods for improving the toughness of biaxially oriented nylon films mainly include adding toughening agents and changing the polymerization process of nylon. Although adding toughening agents can improve the toughness of nylon films to a certain extent, it often has an adverse impact on other properties of biaxially oriented nylon films, such as reducing the barrier property and heat resistance of biaxially oriented nylon films. At the same time, the addition of toughening agents may also lead to an increase in cost, limiting its large-scale application. For the method of changing the nylon polymerization process, although it can improve the molecular structure of nylon and enhance the toughness of the material, the existing process adjustment has limited effect on improving the toughness of biaxially oriented nylon films, and the process is complex, the production process is not easy to control, and it is difficult to achieve industrial large-scale production, unable to meet the growing market demand for high-toughness biaxially oriented nylon films.

[0004] To solve the above problems, the Chinese invention patent with the authorization announcement number CN115819960B discloses a high-toughness biaxially oriented barrier nylon film and a preparation method thereof. Among them, a high-toughness biaxially oriented barrier nylon film includes a first surface layer, a second surface layer, and a core layer; by mass percentage, the raw materials of the first surface layer and the second surface layer include 98 - 99.8% of functional nylon masterbatch, 0.1% - 1% of anti-blocking agent, and 0.1% - 1% of slip agent; the raw materials of the core layer include 100% of functional nylon masterbatch; by mass percentage, the raw materials of the functional nylon masterbatch include: 13 - 81.3% of nylon, 7.5 - 30% of copolyamide, 5 - 30% of nylon elastomer, 5 - 20% of polyketone resin, 1 - 5% of rare earth stearate, 0.1 - 1% of compatibilizer, and 0.1 - 1% of antioxidant. However, the tear strength and low-temperature impact toughness of this nylon film still need to be further improved.

[0005] It can be seen that there is still a need in this field for a high-toughness biaxially oriented nylon film with high tensile strength, good tear resistance, excellent barrier property and low-temperature impact resistance, and a production method thereof. Summary of the Invention

[0006] The main object of the present invention is to provide a high-toughness biaxially oriented nylon film with high tensile strength, good tear resistance, excellent barrier properties and low-temperature impact resistance, and a production method thereof.

[0007] To achieve the above object, the present invention provides a high-toughness biaxially oriented nylon film, which is made of the following raw materials in parts by weight: 40-50 parts of copolyamide resin, 10-20 parts of nylon 12, 15-25 parts of thermoplastic polyamide elastomer, 3-6 parts of nano filler, 1-3 parts of coupling agent, 10-20 parts of reinforcing fiber, 5-8 parts of additive, 3-7 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer, 6-10 parts of modified cellulose nanocrystals, 2-4 parts of amino-terminated hyperbranched polyamide, 1-3 parts of 3,3'-diamino-4,4'-difluorodiphenyl sulfone; the modified cellulose nanocrystals are allyl succinimidyl carbonate, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methylacrylate, 1,4-diacryloyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline, vinyltrimethoxysilane co-modified cellulose nanocrystals.

[0008] Preferably, the copolyamide resin is UBE NYLON®5033B PA6 / 66.

[0009] Preferably, the nylon 12 is Ube 3030JFX1 from Japan.

[0010] Preferably, the thermoplastic polyamide elastomer is thermoplastic polyamide elastomer KHX1040 provided by Xinyuan Chemical.

[0011] Preferably, the nano filler is a mixture of nano calcium carbonate and polymer-grade nano organic montmorillonite in a mass ratio of 1:(1-2).

[0012] Preferably, the polymer-grade nano organic montmorillonite is NANOLC-NP301 polymer-grade organic montmorillonite.

[0013] Preferably, the average particle size of the nano calcium carbonate is 10-90 nm.

[0014] Preferably, the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570.

[0015] Preferably, the reinforcing fiber is nano boron fiber, with an average diameter of 30-100 nm and an aspect ratio of (20-30):1.

[0016] Preferably, the additive is a mixture of antioxidant, lubricant, compatibilizer, and anti-sticking agent in a mass ratio of 1:(0.8-1.2):(3-5):1.

[0017] Preferably, the antioxidant is at least one of antioxidant 1010, antioxidant 1076, and antioxidant 168; the lubricant is at least one of pentaerythritol stearate, zinc stearate, and ethylene bisstearamide; the compatibilizer is maleic anhydride grafted polypropylene, and the MAH-g-PP is selected from the grade EXXELOR PO1020 provided by ExxonMobil of the United States; the anti-adhesive is at least one of silica, talcum powder, and calcium carbonate; the particle size of the anti-adhesive is 1600-2000 mesh.

[0018] Preferably, the ethylene-methyl acrylate-glycidyl methacrylate terpolymer is Arkema LOTADER AX8900.

[0019] Preferably, the preparation method of the modified cellulose nanocrystals includes the following steps: uniformly dispersing cellulose nanocrystals in an organic solvent, then adding allyl succinimidyl carbonate, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methylacrylate, 1,4-diallyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline, vinyltrimethoxysilane, and an initiator thereto, and stirring and reacting at 65-75°C for 3-6 h in an inert gas atmosphere, and then removing the solvent by rotary evaporation to obtain the modified cellulose nanocrystals.

[0020] Preferably, the mass ratio of the cellulose nanocrystals, organic solvent, allyl succinimidyl carbonate, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methylacrylate, 1,4-diallyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline, vinyltrimethoxysilane, and initiator is 3:(10-15):(0.6-1):0.5:0.3:(0.3-0.5):(0.05-0.1).

[0021] Preferably, the organic solvent is at least one of dimethyl sulfoxide, N,N-dimethylformamide, and N-methylpyrrolidone.

[0022] Preferably, the initiator is azobisisobutyronitrile; the inert gas is any one of nitrogen, helium, neon, and argon.

[0023] Preferably, the length of the cellulose nanocrystals is 100-500 nm, the diameter is 20-100 nm, and they are provided by Beijing Naxun Technology Co., Ltd.

[0024] Preferably, the amino-terminated hyperbranched polyamide is amino-terminated hyperbranched polyamide Hyper N102, provided by Wuhan Hyperbranched Resin Technology Co., Ltd.

[0025] Another object of the present invention is to provide a production method of the high-toughness biaxially stretched nylon film, comprising the following steps: Step S1: Mix a copolymer nylon resin, nylon 12, a thermoplastic polyamide elastomer, a nano filler, a coupling agent, reinforcing fibers, additives, an ethylene-methyl acrylate-glycidyl methacrylate terpolymer, and modified cellulose nanocrystals by weight parts, and stir in a high-speed mixer at a rotation speed of 1400-2000 r / min for 20-25 minutes to obtain a mixed material; extrude, cast, and sheet the mixed material through a twin-screw extruder in sequence to form a sheet; Step S2: Stretch the above sheet by a biaxial stretching process to form a nylon film; Step S3: Disperse an amino-terminated hyperbranched polyamide and 3,3'-diamino-4,4'-difluorodiphenyl sulfone in dimethyl sulfoxide to obtain a dispersion liquid, uniformly coat the surface of the nylon film, and dry at 95-105 °C for 3-5 h to obtain a high-toughness biaxially stretched nylon film.

[0026] Preferably, in step S1, the extrusion temperature of the twin-screw extruder is 240-260 °C, and the screw rotation speed is 350-400 rpm; in step S2, the biaxial stretching process is specifically: the stretching temperature is 105-120 °C, the stretching rate is 110-80 mm / s, the heat setting temperature is 180-200 °C, and the stretching ratio is (3-5):1.

[0027] Preferably, in step S3, the mass ratio of the amino-terminated hyperbranched polyamide to dimethyl sulfoxide is 1:(6-10).

[0028] Due to the application of the above technical solution, the present invention has the following beneficial effects: (1) The production method of the high-toughness biaxially stretched nylon film disclosed by the present invention has a simple process, is easy to control, and can realize large-scale industrial production. The parameter settings of each production step are reasonable, which improves the production efficiency and reduces the production cost while ensuring the product quality.

[0029] (2)The high-toughness biaxially oriented nylon film disclosed by the present invention is made of the following raw materials by weight: 40-50 parts of copolyamide resin, 10-20 parts of nylon 12, 15-25 parts of thermoplastic polyamide elastomer, 3-6 parts of nano filler, 1-3 parts of coupling agent, 10-20 parts of reinforcing fiber, 5-8 parts of additive, 3-7 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer, 6-10 parts of modified cellulose nanocrystals, 2-4 parts of amino-terminated hyperbranched polyamide, and 1-3 parts of 3,3'-diamino-4,4'-difluorodiphenyl sulfone; through the mutual cooperation and joint action of the raw materials, the prepared nylon film has high tensile strength, good tear resistance, excellent barrier performance and low-temperature impact resistance; using copolyamide resin, nylon 12, and thermoplastic polyamide elastomer as the blend substrate combines their advantages, making the prepared nylon film have greater tensile strength, better tear resistance, and more excellent barrier performance and low-temperature impact resistance; the addition of nano filler further promotes the improvement of the above properties; the ethylene-methyl acrylate-glycidyl methacrylate terpolymer forms hydrogen bonds with the nylon resin through the polar groups on the molecular chain, effectively enhancing the compatibility and flexibility of the blend system, and further improving the above properties; at the same time, the introduced epoxy group can provide reaction sites for subsequent crosslinking and curing.

[0030] (3)For the high-toughness biaxially oriented nylon film disclosed by the present invention, the addition of modified cellulose nanocrystals can construct a high-strength three-dimensional network structure framework in the nylon matrix, effectively improving the tensile strength, tear strength and toughness of the nylon film. Through modification, the dispersion uniformity of cellulose nanocrystals and their compatibility with the nylon matrix can be improved; the modified cellulose nanocrystals are allyl succinimidyl carbonate, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methylacrylate, 1,4-diacryloyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline, and vinyltrimethoxysilane co-modified cellulose nanocrystals. At the same time, the structures of succinimidyl carbonate, benzotriazole, quinoxaline and trimethoxysilane are introduced. Under the multiple effects of electronic effect, steric effect and conjugation effect, the prepared nylon film has greater tensile strength, better tear resistance, more excellent barrier performance and low-temperature impact resistance, better aging resistance and longer service life.

[0031] (4)The high-toughness biaxially oriented nylon film disclosed by the present invention. The amino groups on the terminal amino hyperbranched polyamide and 3,3'-diamino-4,4'-difluorodiphenyl sulfone can undergo epoxy ring-opening reactions with the epoxy groups introduced into the nylon film to form an interpenetrating network structure, which can effectively improve the mechanical properties, barrier properties, and low-temperature impact resistance of the nylon film. The terminal amino hyperbranched polyamide has a highly branched molecular structure, and the amide group structure thereon is the same as that of the substrate, which can quickly penetrate into the interfaces of each component, significantly improve the interfacial bonding force, and enhance the overall performance of the nylon film. The introduction of fluorinated phenyl sulfone, in cooperation with other structures, can further improve the tensile strength, tear resistance, barrier properties, and low-temperature impact resistance. Detailed Embodiments

[0032] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments in the following description are only examples, and those skilled in the art can think of other obvious variations. Example 1

[0033] A high-toughness biaxially oriented nylon film is made from the following raw materials in parts by weight: 40 parts of copolymerized nylon resin, 10 parts of nylon 12, 15 parts of thermoplastic polyamide elastomer, 3 parts of nano-fillers, 1 part of coupling agent, 10 parts of reinforcing fibers, 5 parts of additives, 3 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer, 6 parts of modified cellulose nanocrystals, 2 parts of terminal amino hyperbranched polyamide, and 1 part of 3,3'-diamino-4,4'-difluorodiphenyl sulfone; the modified cellulose nanocrystals are allyl succinimidyl carbonate, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methylacrylate, 1,4-diacryloyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline, and vinyltrimethoxysilane co-modified cellulose nanocrystals.

[0034] The copolyamide resin is UBE NYLON® 5033B PA6 / 66; the nylon 12 is Ube 3030JFX1 from Japan; the thermoplastic polyamide elastomer is thermoplastic polyamide elastomer KHX1040 provided by Xinyuan Chemical; the nano-filler is a mixture of nano-calcium carbonate and polymer-grade nano-organophilic montmorillonite in a mass ratio of 1:1; the polymer-grade nano-organophilic montmorillonite is NANOLC-NP301 polymer-grade organophilic montmorillonite; the average particle size of the nano-calcium carbonate is 10 nm; the coupling agent is silane coupling agent KH550; the reinforcing fiber is nano-boron fiber with an average diameter of 30 nm and an aspect ratio of 20:1; the additive is a mixture of antioxidant, lubricant, compatibilizer, and anti-sticking agent in a mass ratio of 1:0.8:3:1; the antioxidant is antioxidant 1010; the lubricant is pentaerythritol stearate; the compatibilizer is maleic anhydride grafted polypropylene, selected from MAH-g-PP of the grade EXXELOR PO1020 provided by ExxonMobil of the United States; the anti-sticking agent is silica; the particle size of the anti-bonding agent is 1600 mesh; the ethylene-methyl acrylate-glycidyl methacrylate terpolymer is Arkema LOTADER AX8900.

[0035] The preparation method of the modified cellulose nanocrystals includes the following steps: uniformly disperse cellulose nanocrystals in an organic solvent, then add allyl succinimidyl carbonate, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate, 1,4-diacryloyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline, vinyltrimethoxysilane, and an initiator thereto, and stir and react at 65 °C for 3 h in an inert gas atmosphere, and then remove the solvent by rotary evaporation to obtain the modified cellulose nanocrystals; the mass ratio of the cellulose nanocrystals, organic solvent, allyl succinimidyl carbonate, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate, 1,4-diacryloyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline, vinyltrimethoxysilane, and initiator is 3:10:0.6:0.5:0.3:0.3:0.05; the organic solvent is dimethyl sulfoxide; the initiator is azobisisobutyronitrile; the inert gas is nitrogen; the length of the cellulose nanocrystals is 100 - 500 nm, and the diameter is 20 - 100 nm, provided by Beijing Nasson Technology Co., Ltd.

[0036] The amino-terminated hyperbranched polyamide is amino-terminated hyperbranched polyamide Hyper N102 provided by Wuhan Hyperbranched Resin Technology Co., Ltd.

[0037] A production method of the high-toughness biaxially oriented nylon film includes the following steps: Step S1: Mix copolyamide resin, nylon 12, thermoplastic polyamide elastomer, nano filler, coupling agent, reinforcing fiber, additive, ethylene-methyl acrylate-glycidyl methacrylate terpolymer, and modified cellulose nanocrystals by weight. Stir in a high-speed mixer at a speed of 1400 r / min for 20 minutes to obtain a mixed material. Extrude, cast, and film the mixed material through a twin-screw extruder in sequence to form a sheet. Step S2: Stretch the above sheet through a biaxial stretching process to form a nylon film. Step S3: Disperse amino-terminated hyperbranched polyamide and 3,3'-diamino-4,4'-difluorodiphenyl sulfone in dimethyl sulfoxide to obtain a dispersion. Uniformly coat it on the surface of the nylon film and dry it at 95 °C for 3 h to obtain a high-toughness biaxially stretched nylon film.

[0038] In Step S1, the extrusion temperature of the twin-screw extruder is 240 °C and the screw speed is 350 rpm. In Step S2, the biaxial stretching process is specifically as follows: the stretching temperature is 105 °C, the stretching rate is 110 mm / s, the heat setting temperature is 180 °C, and the stretching ratio is 4:1. In Step S3, the mass ratio of amino-terminated hyperbranched polyamide to dimethyl sulfoxide is 1:6. Example 2

[0039] A high-toughness biaxially stretched nylon film is made from the following raw materials by weight: 43 parts of copolyamide resin, 12 parts of nylon 12, 17 parts of thermoplastic polyamide elastomer, 4 parts of nano filler, 1.5 parts of coupling agent, 13 parts of reinforcing fiber, 6 parts of additive, 4 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer, 7 parts of modified cellulose nanocrystals, 2.5 parts of amino-terminated hyperbranched polyamide, and 1.5 parts of 3,3'-diamino-4,4'-difluorodiphenyl sulfone; the modified cellulose nanocrystals are allyl succinimidyl carbonate, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methylacrylate, 1,4-diacryloyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline, and vinyltrimethoxysilane co-modified cellulose nanocrystals.

[0040] The copolymerized nylon resin is UBE NYLON® 5033B PA6 / 66; the nylon 12 is Ube 3030JFX1 from Japan; the thermoplastic polyamide elastomer is thermoplastic polyamide elastomer KHX1040 provided by Xinyuan Chemical; the nano filler is a mixture of nano calcium carbonate and polymer-grade nano organic montmorillonite in a mass ratio of 1:1.3; the polymer-grade nano organic montmorillonite is NANOLC-NP301 polymer-grade organic montmorillonite; the average particle size of the nano calcium carbonate is 30 nm; the coupling agent is silane coupling agent KH560; the reinforcing fiber is nano boron fiber with an average diameter of 50 nm and an aspect ratio of 23:1; the additive is a mixture of antioxidant, lubricant, compatibilizer, and anti-sticking agent in a mass ratio of 1:0.9:3.5:1; the antioxidant is antioxidant 1076; the lubricant is zinc stearate; the compatibilizer is maleic anhydride grafted polypropylene, selected from MAH-g-PP with the trade name EXXELOR PO1020 provided by ExxonMobil of the United States; the anti-sticking agent is talc powder; the particle size of the anti-bonding agent is 1700 mesh; the ethylene-methyl acrylate-glycidyl methacrylate terpolymer is Arkema LOTADER AX8900.

[0041] The preparation method of the modified cellulose nanocrystals includes the following steps: uniformly disperse the cellulose nanocrystals in an organic solvent, then add allyl succinimidyl carbonate, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate, 1,4-diallyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline, vinyltrimethoxysilane, and an initiator thereto, and stir and react at 67 °C for 4 h in an inert gas atmosphere, and then remove the solvent by rotary evaporation to obtain the modified cellulose nanocrystals; the mass ratio of the cellulose nanocrystals, organic solvent, allyl succinimidyl carbonate, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate, 1,4-diallyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline, vinyltrimethoxysilane, and initiator is 3:12:0.7:0.5:0.3:0.35:0.06; the organic solvent is N,N-dimethylformamide; the initiator is azobisisobutyronitrile; the inert gas is helium; the length of the cellulose nanocrystals is 100 - 500 nm, and the diameter is 20 - 100 nm, provided by Beijing Naxun Technology Co., Ltd.

[0042] The amino-terminated hyperbranched polyamide is amino-terminated hyperbranched polyamide Hyper N102 provided by Wuhan Hyperbranched Resin Technology Co., Ltd.

[0043] A production method of the high-toughness biaxially oriented nylon film includes the following steps: Step S1: Mix copolyamide resin, nylon 12, thermoplastic polyamide elastomer, nano filler, coupling agent, reinforcing fiber, additive, ethylene-methyl acrylate-glycidyl methacrylate terpolymer, and modified cellulose nanocrystals by weight. Stir in a high-speed mixer at a speed of 1600 r / min for 22 minutes to obtain a mixed material. Extrude, cast, and film the mixed material through a twin-screw extruder in sequence to form a sheet. Step S2: Stretch the above sheet through a biaxial stretching process to form a nylon film. Step S3: Disperse amino-terminated hyperbranched polyamide and 3,3'-diamino-4,4'-difluorodiphenyl sulfone in dimethyl sulfoxide to obtain a dispersion liquid. Uniformly coat it on the surface of the nylon film and dry it at 98 °C for 3.5 h to obtain a high-toughness biaxially stretched nylon film.

[0044] In Step S1, the extrusion temperature of the twin-screw extruder is 245 °C, and the screw speed is 360 rpm. In Step S2, the biaxial stretching process is specifically as follows: the stretching temperature is 109 °C, the stretching rate is 100 mm / s, the heat setting temperature is 185 °C, and the stretching ratio is 4:1. In Step S3, the mass ratio of amino-terminated hyperbranched polyamide to dimethyl sulfoxide is 1:7. Example 3

[0045] A high-toughness biaxially stretched nylon film is made from the following raw materials by weight: 45 parts of copolyamide resin, 15 parts of nylon 12, 20 parts of thermoplastic polyamide elastomer, 4.5 parts of nano filler, 2 parts of coupling agent, 15 parts of reinforcing fiber, 6.5 parts of additive, 5 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer, 8 parts of modified cellulose nanocrystals, 3 parts of amino-terminated hyperbranched polyamide, and 2 parts of 3,3'-diamino-4,4'-difluorodiphenyl sulfone; the modified cellulose nanocrystals are allyl succinimidyl carbonate, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methylacrylate, 1,4-diacryloyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline, and vinyltrimethoxysilane co-modified cellulose nanocrystals.

[0046] The copolymerized nylon resin is UBE NYLON® 5033B PA6 / 66; the nylon 12 is Ube 3030JFX1 from Japan; the thermoplastic polyamide elastomer is thermoplastic polyamide elastomer KHX1040 provided by Xinyuan Chemical; the nano filler is a mixture of nano calcium carbonate and polymer-grade nano organic montmorillonite in a mass ratio of 1:1.5; the polymer-grade nano organic montmorillonite is NANOLC-NP301 polymer-grade organic montmorillonite; the average particle size of the nano calcium carbonate is 60 nm; the coupling agent is silane coupling agent KH570; the reinforcing fiber is nano boron fiber with an average diameter of 70 nm and a length-to-diameter ratio of 25:1; the additive is a mixture of antioxidant, lubricant, compatibilizer, and anti-sticking agent in a mass ratio of 1:1:4:1; the antioxidant is antioxidant 168; the lubricant is ethylene bisstearamide; the compatibilizer is maleic anhydride grafted polypropylene, selected from MAH-g-PP of the grade EXXELOR PO1020 provided by ExxonMobil of the United States; the anti-sticking agent is calcium carbonate; the particle size of the anti-bonding agent is 1800 mesh; the ethylene-methyl acrylate-glycidyl methacrylate terpolymer is Arkema LOTADER AX8900.

[0047] The preparation method of the modified cellulose nanocrystals comprises the following steps: uniformly dispersing cellulose nanocrystals in an organic solvent, then adding allyl succinimidyl carbonate, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methylacrylate, 1,4-diallyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline, vinyltrimethoxysilane, and an initiator, and stirring and reacting at 70 °C for 4.5 h in an inert gas atmosphere, and then removing the solvent by rotary evaporation to obtain the modified cellulose nanocrystals; the mass ratio of the cellulose nanocrystals, organic solvent, allyl succinimidyl carbonate, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methylacrylate, 1,4-diallyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline, vinyltrimethoxysilane, and initiator is 3:13:0.8:0.5:0.3:0.4:0.08; the organic solvent is N-methylpyrrolidone; the initiator is azobisisobutyronitrile; the inert gas is neon; the length of the cellulose nanocrystals is 100-500 nm, and the diameter is 20-100 nm, provided by Beijing Nasson Technology Co., Ltd.

[0048] The amino-terminated hyperbranched polyamide is amino-terminated hyperbranched polyamide Hyper N102 provided by Wuhan Hyperbranched Resin Technology Co., Ltd.

[0049] A production method of the high-toughness biaxially oriented nylon film comprises the following steps: Step S1: Mix copolyamide resin, nylon 12, thermoplastic polyamide elastomer, nano filler, coupling agent, reinforcing fiber, additive, ethylene-methyl acrylate-glycidyl methacrylate terpolymer, and modified cellulose nanocrystals by weight. Stir in a high-speed mixer at a speed of 1700 r / min for 23 minutes to obtain a mixed material. Extrude, cast, and film the mixed material through a twin-screw extruder in sequence to form a sheet. Step S2: Stretch the above sheet through a biaxial stretching process to form a nylon film. Step S3: Disperse amino-terminated hyperbranched polyamide and 3,3'-diamino-4,4'-difluorodiphenyl sulfone in dimethyl sulfoxide to obtain a dispersion. Uniformly coat it on the surface of the nylon film and dry it at 100 °C for 4 h to obtain a high-toughness biaxially stretched nylon film.

[0050] In Step S1, the extrusion temperature of the twin-screw extruder is 250 °C and the screw speed is 380 rpm. In Step S2, the specific biaxial stretching process is as follows: the stretching temperature is 112 °C, the stretching rate is 95 mm / s, the heat setting temperature is 190 °C, and the stretching ratio is 4:1. In Step S3, the mass ratio of amino-terminated hyperbranched polyamide to dimethyl sulfoxide is 1:8. Example 4

[0051] A high-toughness biaxially stretched nylon film is made from the following raw materials by weight: 48 parts of copolyamide resin, 18 parts of nylon 12, 23 parts of thermoplastic polyamide elastomer, 5.5 parts of nano filler, 2.5 parts of coupling agent, 18 parts of reinforcing fiber, 7.5 parts of additive, 6 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer, 9.5 parts of modified cellulose nanocrystals, 3.5 parts of amino-terminated hyperbranched polyamide, and 2.5 parts of 3,3'-diamino-4,4'-difluorodiphenyl sulfone; the modified cellulose nanocrystals are allyl succinimidyl carbonate, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methylacrylate, 1,4-diacryloyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline, and vinyltrimethoxysilane co-modified cellulose nanocrystals.

[0052] The copolymerized nylon resin is UBE NYLON®5033B PA6 / 66; the nylon 12 is Ube 3030JFX1 from Japan; the thermoplastic polyamide elastomer is thermoplastic polyamide elastomer KHX1040 provided by Xinyuan Chemical; the nano filler is a mixture of nano calcium carbonate and polymer-grade nano organic montmorillonite in a mass ratio of 1:1.8; the polymer-grade nano organic montmorillonite is NANOLC-NP301 polymer-grade organic montmorillonite; the average particle size of the nano calcium carbonate is 80 nm; the coupling agent is a mixture of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570 in a mass ratio of 1:2:3; the reinforcing fiber is nano boron fiber with an average diameter of 90 nm and an aspect ratio of 29:1; the additive is a mixture of antioxidant, lubricant, compatibilizer, and anti-sticking agent in a mass ratio of 1:1.1:4.5:1; the antioxidant is a mixture of antioxidant 1010, antioxidant 1076, and antioxidant 168 in a mass ratio of 1:1:2; the lubricant is a mixture of pentaerythritol stearate, zinc stearate, and ethylene bis-stearamide in a mass ratio of 2:1:1; the compatibilizer is maleic anhydride grafted polypropylene, selected from MAH-g-PP with the trade name EXXELOR PO1020 provided by ExxonMobil in the United States; the anti-sticking agent is a mixture of silica, talc powder, and calcium carbonate in a mass ratio of 1:3:1; the particle size of the anti-bonding agent is 1900 mesh; the ethylene-methyl acrylate-glycidyl methacrylate terpolymer is Arkema LOTADER AX8900.

[0053] The preparation method of the modified cellulose nanocrystals comprises the following steps: uniformly dispersing cellulose nanocrystals in an organic solvent, then adding allyl succinimidyl carbonate, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate, 1,4-diallyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline, vinyltrimethoxysilane and an initiator thereto, and carrying out a stirring reaction at 73 °C for 5.5 h in an inert gas atmosphere, and then removing the solvent by rotary evaporation to obtain the modified cellulose nanocrystals; the mass ratio of the cellulose nanocrystals, the organic solvent, allyl succinimidyl carbonate, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate, 1,4-diallyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline, vinyltrimethoxysilane, and the initiator is 3:14:0.95:0.5:0.3:0.45:0.09; the organic solvent is a mixture of dimethyl sulfoxide, N,N-dimethylformamide, and N-methylpyrrolidone in a mass ratio of 1:1:1; the initiator is azobisisobutyronitrile; the inert gas is argon; the length of the cellulose nanocrystals is 100-500 nm, and the diameter is 20-100 nm, which are provided by Beijing Nasson Technology Co., Ltd.

[0054] The amino-terminated hyperbranched polyamide is amino-terminated hyperbranched polyamide Hyper N102, which is provided by Wuhan Hyperbranched Resin Technology Co., Ltd.

[0055] A production method of the high-toughness biaxially oriented nylon film comprises the following steps: Step S1: Mixing a copolymer nylon resin, nylon 12, a thermoplastic polyamide elastomer, a nano filler, a coupling agent, reinforcing fibers, an additive, an ethylene-methyl acrylate-glycidyl methacrylate terpolymer, and the modified cellulose nanocrystals by weight, and stirring at a speed of 1900 r / min in a high-speed mixer for 24 minutes to obtain a mixed material; extruding, casting, and calendaring the mixed material in sequence through a twin-screw extruder to form a sheet; Step S2: Stretching the above sheet by a biaxial stretching process to form a nylon film; Step S3: Disperse the amino-terminated hyperbranched polyamide and 3,3'-diamino-4,4'-difluorodiphenyl sulfone in dimethyl sulfoxide to obtain a dispersion liquid, uniformly coat the dispersion liquid on the surface of the nylon film, and dry at 103 °C for 4.5 h to obtain the high-toughness biaxially oriented nylon film.

[0056] In step S1, the extrusion temperature of the twin-screw extruder is 255 °C and the screw speed is 390 rpm; in step S2, the specific biaxial stretching process is as follows: the stretching temperature is 118 °C, the stretching rate is 85 mm / s, the heat setting temperature is 195 °C, and the stretching ratio is 4:1; in step S3, the mass ratio of the amino-terminated hyperbranched polyamide to dimethyl sulfoxide is 1:9.5. Example 5

[0057] A high-toughness biaxially stretched nylon film is made from the following raw materials by weight: 50 parts of copolymerized nylon resin, 20 parts of nylon 12, 25 parts of thermoplastic polyamide elastomer, 6 parts of nano filler, 3 parts of coupling agent, 20 parts of reinforcing fiber, 8 parts of additive, 7 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer, 10 parts of modified cellulose nanocrystals, 4 parts of amino-terminated hyperbranched polyamide, and 3 parts of 3,3'-diamino-4,4'-difluorodiphenyl sulfone; the modified cellulose nanocrystals are allyl succinimidyl carbonate, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methylacrylate, 1,4-diacryloyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline, and vinyltrimethoxysilane co-modified cellulose nanocrystals.

[0058] The copolymerized nylon resin is UBE NYLON®5033B PA6 / 66; the nylon 12 is Ube 3030JFX1 from Japan; the thermoplastic polyamide elastomer is thermoplastic polyamide elastomer KHX1040 provided by Xinyuan Chemical; the nano filler is a mixture of nano calcium carbonate and polymer-grade nano organic montmorillonite in a mass ratio of 1:2; the polymer-grade nano organic montmorillonite is NANOLC-NP301 polymer-grade organic montmorillonite; the average particle size of the nano calcium carbonate is 90 nm; the coupling agent is silane coupling agent KH550; the reinforcing fiber is nano boron fiber with an average diameter of 100 nm and a length-to-diameter ratio of 30:1; the additive is a mixture of antioxidant, lubricant, compatibilizer, and anti-blocking agent in a mass ratio of 1:1.2:5:1; the antioxidant is antioxidant 1076; the lubricant is zinc stearate; the compatibilizer is maleic anhydride grafted polypropylene, selected from MAH-g-PP of the grade EXXELOR PO1020 provided by Exxon in the United States; the anti-blocking agent is calcium carbonate; the particle size of the anti-blocking agent is 2000 mesh; the ethylene-methyl acrylate-glycidyl methacrylate terpolymer is Arkema LOTADER AX8900.

[0059] The preparation method of the modified cellulose nanocrystals comprises the following steps: uniformly dispersing cellulose nanocrystals in an organic solvent, then adding allyl succinimidyl carbonate, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate, 1,4-diacryloyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline, vinyltrimethoxysilane and an initiator thereto, and stirring and reacting at 75 °C for 6 h under an inert gas atmosphere, and then removing the solvent by rotary evaporation to obtain the modified cellulose nanocrystals; the mass ratio of the cellulose nanocrystals, the organic solvent, allyl succinimidyl carbonate, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate, 1,4-diacryloyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline, vinyltrimethoxysilane, and the initiator is 3:15:1:0.5:0.3:0.5:0.1; the organic solvent is dimethyl sulfoxide; the initiator is azobisisobutyronitrile; the inert gas is nitrogen; the length of the cellulose nanocrystals is 100-500 nm, the diameter is 20-100 nm, and they are provided by Beijing Nasson Technology Co., Ltd.

[0060] The amino-terminated hyperbranched polyamide is amino-terminated hyperbranched polyamide Hyper N102, which is provided by Wuhan Hyperbranched Resin Technology Co., Ltd.

[0061] A production method of the high-toughness biaxially oriented nylon film comprises the following steps: Step S1: Mixing a copolyamide resin, nylon 12, a thermoplastic polyamide elastomer, a nano filler, a coupling agent, reinforcing fibers, an additive, an ethylene-methyl acrylate-glycidyl methacrylate terpolymer, and the modified cellulose nanocrystals by weight parts, and stirring at a rotation speed of 2000 r / min in a high-speed mixer for 25 minutes to obtain a mixed material; extruding, casting, and forming the mixed material through a twin-screw extruder in sequence to form a sheet; Step S2: Stretching the above sheet through a biaxial stretching process to form a nylon film; Step S3: Disperse the amino-terminated hyperbranched polyamide and 3,3'-diamino-4,4'-difluorodiphenyl sulfone in dimethyl sulfoxide to obtain a dispersion liquid, uniformly coat the dispersion liquid on the surface of the nylon film, and dry at 105 °C for 5 h to obtain the high-toughness biaxially oriented nylon film.

[0062] In step S1, the extrusion temperature of the twin-screw extruder is 260 °C, and the screw rotation speed is 400 rpm; in step S2, the biaxial stretching process is specifically: the stretching temperature is 120 °C, the stretching rate is 80 mm / s, the heat setting temperature is 200 °C, and the stretching ratio is 4:1; in step S3, the mass ratio of the amino-terminated hyperbranched polyamide to dimethyl sulfoxide is 1:10.

[0063] Comparative Example 1 A high-toughness biaxially stretched nylon film and its production method are basically the same as those of Example 1, except that an equal amount of copolymer nylon resin is used to replace nylon 12, and 3,3'-diamino-4,4'-difluorodiphenyl sulfone and 1,4-diacryloyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline are not added.

[0064] Comparative Example 2 A high-toughness biaxially stretched nylon film and its production method are basically the same as those of Example 1, except that an equal amount of thermoplastic polyamide elastomer is used to replace the ethylene-methyl acrylate-glycidyl methacrylate terpolymer, and 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methylacrylate is not added.

[0065] To further illustrate the beneficial technical effects of the high-toughness biaxially stretched nylon film involved in each embodiment of the present invention, relevant performance tests were carried out on the high-toughness biaxially stretched nylon films involved in Examples 1-5 and Comparative Examples 1-2. The test results are shown in Table 1. The thickness of the test sample film is 20 μm. The test methods are as follows: (1) Tensile properties: The tensile strength test was carried out according to GB / T1040.1-2018. (2) Low-temperature impact resistance: Referring to ASTM D256-10 "Standard Test Method for Plastic Pendulum Impact Strength", the nylon film of the present invention and the traditional nylon film specimens were placed in a -40°C environmental chamber for 2 hours, and then tested using a pendulum impact testing machine. The specimen size is 80mm×10mm, the impact speed is 3.5m / s, and each sample is tested 8 times, and the average value is taken. (3) Tear resistance: Referring to GB / T 16578.1-2008 "Plastics - Films and Sheets - Determination of Tear Resistance - Part 1: Trouser Tear Method", trouser tear specimens were used, with a size of (200±2)mm×(75±1)mm, and the tear speed was 100mm / min. Each sample was tested 8 times, and the average value was taken. (4) Gas barrier property: The oxygen transmission rate was determined referring to GB / T 19789-2021 "Packaging Materials - Plastic Films and Sheets - Test Method for Oxygen Transmission - Coulometer Detection Method", and the test conditions were a temperature of 23°C and a relative humidity of 50%.

[0066] Table 1 Performance test results of high-toughness biaxially stretched nylon film Project Tensile strength Low temperature impact strength Tear resistance Oxygen transmission rate Unit MPa <![CDATA[kJ / m 2 > KN / m cm³ / (m²・24h・0.1MPa) Example 1 325 25 85 4.12 Example 2 329 27 87 4.00 Example 3 335 30 90 3.75 Example 4 338 31 92 3.10 Example 5 340 33 93 3.00 Comparative Example 1 310 19 80 6.35 Comparative Example 2 304 20 78 8.87 As can be seen from Table 1, the high-toughness biaxially oriented nylon film disclosed in the embodiments of the present invention has higher tensile properties and tear resistance than the products of the comparative examples, and also has more excellent low-temperature impact properties and barrier properties; the combined use of nylon 12, ethylene-methyl acrylate-glycidyl methacrylate terpolymer, 3,3'-diamino-4,4'-difluorodiphenyl sulfone, 1,4-diacryloyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline and 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate is beneficial to improving the above properties.

[0067] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification is only the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection required by the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-toughness biaxially oriented nylon film, characterized in that: The invention comprises the following raw materials in parts by weight: 40-50 parts of copolymerized nylon resin, 10-20 parts of nylon 12, 15-25 parts of thermoplastic polyamide elastomer, 3-6 parts of nano filler, 1-3 parts of coupling agent, 10-20 parts of reinforcing fiber, 5-8 parts of additive, 3-7 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer, 6-10 parts of modified cellulose nanocrystal, 2-4 parts of amino-terminated hyperbranched polyamide and 1-3 parts of 3,3'-diamino-4,4'-difluorodiphenyl sulfone; the modified cellulose nanocrystal is cellulose nanocrystal co-modified with allyl succinimidyl carbonate, 2-[3-(2H-benzotriazole-2-yl)-4-hydroxyphenyl]ethyl 2-methacrylate, 1,4-diacryl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline and vinyltrimethoxysilane.

2. The high-toughness biaxially oriented nylon film according to claim 1, characterized in that: The copolymer nylon resin is UBE NYLON®5033B PA6 / 66; the nylon 12 is Japan Ube 3030JFX1; the thermoplastic polyamide elastomer is thermoplastic polyamide elastomer KHX1040; and the nano filler is a mixture of nano calcium carbonate and polymer-grade nano organic montmorillonite in a mass ratio of 1:(1-2).

3. The high-toughness biaxially oriented nylon film according to claim 2, characterized in that: The polymer-grade nano-organic montmorillonite is NANOLC-NP301 polymer-grade organic montmorillonite; and the average particle size of the nano-calcium carbonate is 10-90 nm.

4. The high-toughness biaxially oriented nylon film according to claim 1, characterized in that: The coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570; the reinforcing fiber is nano-boron fiber with an average diameter of 30-100nm and an aspect ratio of (20-30):

1.

5. The high-toughness biaxially oriented nylon film according to claim 1, characterized in that: The additives are antioxidants, lubricants, compatibilizers, and anti-sticking agents mixed in a mass ratio of 1:(0.8-1.2):(3-5):1; the ethylene-methyl acrylate-glycidyl methacrylate terpolymer is Arkema LOTADER AX8900; and the amino-terminated hyperbranched polyamide is amino-terminated hyperbranched polyamide Hyper N102.

6. The high-toughness biaxially oriented nylon film according to claim 5, characterized in that: The antioxidant is at least one of antioxidant 1010, antioxidant 1076, and antioxidant 168; the lubricant is at least one of pentaerythritol stearate, zinc stearate, and ethylene bisstearamide; the compatibilizer is maleic anhydride grafted polypropylene, selected from MAH-g-PP with the brand EXXELOR PO1020 provided by Exxon in the United States; the anti-adhesive agent is at least one of silicon dioxide, talc, and calcium carbonate; and the particle size of the anti-adhesive agent is 1600-2000 mesh.

7. The high-toughness biaxially oriented nylon film according to claim 1, characterized in that: The preparation method of the modified cellulose nanocrystal comprises the following steps: uniformly dispersing the cellulose nanocrystal in an organic solvent, then adding allyl succinimidyl carbonate, 2-[3-(2H-benzotriazole-2-yl)-4-hydroxyphenyl]ethyl 2-methylacrylate, 1,4-diacryl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline, vinyltrimethoxysilane and an initiator thereto, stirring and reacting at 65-75° C. for 3-6 hours in an inert gas atmosphere, and then removing the solvent by rotary evaporation to obtain the modified cellulose nanocrystal.

8. The high-toughness biaxially oriented nylon film according to claim 7, characterized in that: The mass ratio of the cellulose nanocrystals, organic solvent, allyl succinimidyl carbonate, 2-[3-(2H-benzotriazole-2-yl)-4-hydroxyphenyl]ethyl 2-methylacrylate, 1,4-diacryloyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline, vinyltrimethoxysilane and initiator is 3:(10-15):(0.6-1):0.5:0.3:(0.3-0.5):(0.05-0.1); the organic solvent is at least one of dimethyl sulfoxide, N,N-dimethylformamide and N-methylpyrrolidone; the initiator is azobisisobutyronitrile; the inert gas is any one of nitrogen, helium, neon and argon; the length of the cellulose nanocrystals is 100-500nm and the diameter is 20-100nm.

9. A method for producing a high-toughness biaxially oriented nylon film according to any one of claims 1 to 8, characterized in that: The steps include: Step S1, mixing copolymerized nylon resin, nylon 12, thermoplastic polyamide elastomer, nanofiller, coupling agent, reinforcing fiber, additive, ethylene-methyl acrylate-glycidyl methacrylate terpolymer, and modified cellulose nanocrystals according to weight parts, stirring in a high-speed stirrer at a speed of 1400-2000 r / min for 20-25 minutes to obtain a mixed material; extruding the mixed material through a twin-screw extruder, casting and casting, to form a sheet; Step S2, stretching the sheet through a biaxial stretching process to form a nylon film; Step S3, dispersing the amino-terminated hyperbranched polyamide and 3,3'-diamino-4,4'-difluorodiphenyl sulfone in dimethyl sulfoxide to obtain a dispersion, uniformly coating the dispersion on the surface of the nylon membrane, and drying at 95-105° C. for 3-5 hours to obtain a high-toughness biaxially stretched nylon membrane.

10. The method for producing a high-toughness biaxially oriented nylon film according to claim 9, characterized in that: The extrusion temperature of the twin-screw extruder in step S1 is 240-260° C., and the screw speed is 350-400 rpm; the biaxial stretching process in step S2 is specifically as follows: the stretching temperature is 105-120° C., the stretching rate is 110-80 mm / s, the heat setting temperature is 180-200° C., and the stretching ratio is (3-5):1; the mass ratio of the amino-terminated hyperbranched polyamide and dimethyl sulfoxide in step S3 is 1:(6-10).