High-barrier packaging material and preparation method thereof

Abstract

The invention discloses a high-barrier packaging material and a preparation method thereof, and relates to the technical field of packaging materials. When the high-barrier packaging material is prepared, 5, 12-tetrabenzoquinone and tetrabromomethane react to prepare an intermediate; reacting the intermediate with 4-(benzyl acrylate) phenylboronic acid to obtain a stilbene-based cross-linking agent; the preparation method comprises the following steps: carrying out a reaction on polyethylene glycol terephthalate, 3-amino propylene and allyl tri (trimethylsiloxy) silane to prepare functional polyester; reacting the pre-modified nano mica sheet with methyl iodide to obtain a modified nano mica sheet; the preparation method comprises the following steps: uniformly mixing functional polyester, a stilbene-based cross-linking agent, a modified nano mica sheet and 7-methyl-1, 5, 7-triazabicyclo [4.4. 0] dec-5-ene, and carrying out blow molding to obtain the high-barrier packaging material. The high-barrier packaging material prepared by the invention has excellent flame-retardant, antibacterial, anti-aging and high-barrier properties.

Description

Technical Field

[0001] The present invention relates to the technical field of packaging materials, in particular to a high-barrier packaging material and a preparation method thereof. Background Art

[0002] The development of modern industrialization has enabled the mass production of food, medicine, medical devices, electronic equipment, and more, providing people with a wide variety of goods. This has led to increased demand for food preservation and quality assurance, guaranteed shelf life for medicines, antibacterial and antifouling measures for medical devices, and leak and erosion prevention for electronic equipment. High-barrier packaging materials, with their excellent oxygen, water, and permeation resistance, are widely used in food, medicine, precision instruments, and other fields to extend product shelf life and ensure quality stability. When used as packaging materials for food, medicine, and medical devices, high-barrier packaging materials also need to have good antibacterial properties. Currently, commonly used packaging materials on the market include polymers such as PET, PP, PE, PVC, and EVOH, which are generally flammable, antibacterial, and have poor barrier properties. Therefore, it is necessary to develop a high-barrier packaging material with both antibacterial and flame-retardant properties. Summary of the Invention

[0003] The object of the present invention is to provide a high barrier packaging material and a preparation method thereof, so as to solve the problems existing in the prior art.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions: A high-barrier packaging material is prepared by reacting an intermediate and 4-(benzene acrylate)phenylboronic acid to obtain a distyryl crosslinking agent; reacting pre-modified nanomica sheets and methyl iodide to obtain modified nanomica sheets; and uniformly mixing functionalized polyester, the distyryl crosslinking agent, the modified nanomica sheets, and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, and blow molding the mixture. The intermediate is prepared by reacting 5,12-tetraacenoquinone and tetrabromomethane; The functionalized polyester is prepared by reacting polyethylene terephthalate, 3-aminopropylene, and allyl tris(trimethylsiloxy)silane; The pre-modified nano-mica sheet is prepared by reacting pre-treated nano-mica sheet, di(2-bromomethyl)phenylphosphine oxide and piperazine; The pretreated nano-mica sheet is prepared by reacting the nano-mica sheet and (3-bromopropyl)triethoxysilane.

[0005] A method for preparing a high-barrier packaging material, comprising the following steps: (1) The intermediate and 4-(benzene acrylate)phenylboronic acid are added to a mixed solvent with a molar ratio of 1:(5-6) to 24-26 times the mass of the intermediate, and potassium carbonate with a mass of 2-2.2 times the mass of the intermediate and tetrakis(triphenylphosphine)palladium with a mass of 0.1-0.12 times the mass of the intermediate are added. The mixture is stirred and refluxed at 78-82°C and 300-400 r / min for 22-24 hours. The mixture is cooled to room temperature and filtered. The filtrate is dried under vacuum at 60-70°C for 10-12 hours to obtain a distyryl crosslinking agent. (2) Polyethylene terephthalate, 3-aminopropylene, allyl tris(trimethylsiloxy)silane, and N,N-dimethylformamide are mixed uniformly in a mass ratio of 1:(0.4~0.5):(0.3~0.4):(6~8). Under stirring conditions of 70~80℃ and 100~200r / min, an initiator solution of 1~1.2 times the mass of polyethylene terephthalate is added dropwise at a uniform rate within 30min. After the addition is completed, the stirring reaction is continued for 2~3h. N,N-dimethylformamide is removed by rotary evaporation, and the mixture is washed with anhydrous ethanol for 3~5 times. The mixture is dried at 50~60℃ under vacuum conditions for 8~10h to obtain a functionalized polyester. (3) The pre-modified nano-mica flakes, iodomethane and chloroform were mixed uniformly in a mass ratio of 1:(2-3):(20-24), stirred at 200-300 r / min at 20-30 ° C under light-proof conditions for 33-35 h, filtered, washed with anhydrous ethanol and deionized water 3-5 times each, and dried at 60-70 ° C under vacuum conditions for 10-12 h to obtain modified nano-mica flakes; (4) Weigh 98-100 parts of functionalized polyester, 8-10 parts of distyryl crosslinking agent, 2-3 parts of modified nano-mica flakes, and 1-1.4 parts of 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene by mass; mix the functionalized polyester, distyryl crosslinking agent, modified nano-mica flakes, and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene evenly, place the mixture in an injection blow molding machine for blow molding, cool it to room temperature, and demould it to obtain a high barrier packaging material.

[0006] As an optimization, the preparation method of the intermediate in step (1) is as follows: tetrabromomethane and triphenylphosphine are added in a molar ratio of 1:2 to toluene with a mass of 10 to 12 times that of tetrabromomethane, stirred at 10 to 30°C and 300 to 400 r / min for 50 to 60 min, 5,12-tetrabenzoquinone with a mass of 0.3 to 0.4 times that of tetrabromomethane is added, the temperature is raised to 108 to 110°C, stirred and refluxed at 300 to 400 r / min for 22 to 24 h, cooled to room temperature, filtered, and the filtrate is dried at 60 to 70°C under vacuum conditions for 10 to 12 h to obtain the intermediate.

[0007] As an optimization, the preparation method of the mixed solvent in step (1) is: deionized water, anhydrous ethanol, and toluene are uniformly mixed in a volume ratio of 1:1:(19~21) to prepare a mixed solvent.

[0008] As an optimization, the CAS number of the 4-(benzene acrylate)phenylboronic acid in step (1) is 2187511-79-9; the structural formula is: .

[0009] As an optimization, the reaction process of the distyryl crosslinking agent in step (1) is as follows: .

[0010] As an optimization, the polyethylene terephthalate model in step (2) is PETG Eastman GN119 from the United States, purchased from Shabit Plastic Trading (Suzhou) Co., Ltd.

[0011] As an optimization, the preparation method of the initiator solution in step (2) is: benzoyl peroxide and N,N-dimethylformamide are uniformly mixed in a mass ratio of 1:(4~5) to prepare an initiator solution.

[0012] As an optimization, the CAS number of allyl tris(trimethylsilyloxy)silane in step (2) is 7087-21-0; the structural formula is: .

[0013] As an optimization, the preparation method of the pre-modified nano-mica sheet in step (3) is as follows: pre-treated nano-mica sheet, triethylamine and tetrahydrofuran are mixed uniformly in a mass ratio of 1: (0.05-0.07): (30-40), stirred at 10-30°C and 200-300 r / min for 20-30 min, and a monomer mixture of 20-22 times the mass of the pre-treated nano-mica sheet is added dropwise at a uniform speed within 30 min. After the addition is completed, the temperature is raised to 40-50°C, and the stirring reaction is continued for 5-6 h. The pre-modified nano-mica sheet is filtered, washed with anhydrous ethanol and deionized water for 3-5 times each, and dried at 60-70°C under vacuum conditions for 10-12 h to obtain the pre-modified nano-mica sheet.

[0014] As an optimization, the monomer mixture is prepared by adding di(2-bromomethyl)phenylphosphine oxide and piperazine at a molar ratio of 1:(1.2-1.3) to tetrahydrofuran (6-8 times the mass of piperazine) to prepare a monomer mixture.

[0015] As an optimization, the CAS number of the bis(2-bromomethyl)phenylphosphine oxide is 37912-68-8; the structural formula is .

[0016] As an optimization, the preparation method of the pretreated nano-mica sheet is as follows: (3-bromopropyl) triethoxysilane, a 10% hydrochloric acid aqueous solution, deionized water, and anhydrous ethanol are mixed uniformly in a mass ratio of 1: (2~3): (26~30): (30~34), stirred at 10~30°C and 300~500r / min for 20~30min, nano-mica sheets with a mass of 0.6~0.8 times that of (3-bromopropyl) triethoxysilane are added, stirred at 50~60°C and 300~500r / min for 2~3h, filtered, and dried at 65~75°C under vacuum conditions for 9~11h to obtain pretreated nano-mica sheets.

[0017] As an optimization, the nano-mica sheet has a silicon dioxide content of 42.63%, a magnesium content of 28.45%, and an active ingredient content of 99%, and was purchased from Lingshou County Xinjian Mineral Products Processing Plant.

[0018] As an optimization, the process parameters of the blow molding in step (4) are as follows: during the injection process, the material temperature is set to 255~265℃, the injection pressure is set to 110~120MPa, the holding pressure is set to 50~60MPa, the holding time is set to 8~10s, and the mold temperature is set to 85~95℃.

[0019] Compared with the prior art, the present invention has the following beneficial effects: When preparing a high-barrier packaging material, the present invention comprises the following steps: reacting 5,12-tetraacenoquinone and tetrabromomethane to obtain an intermediate; reacting the intermediate and 4-(benzene acrylate)phenylboronic acid to obtain a distyryl crosslinking agent; reacting polyethylene terephthalate, 3-aminopropylene, and allyl tris(trimethylsiloxy)silane to obtain a functionalized polyester; reacting nanomica sheets and (3-bromopropyl)triethoxysilane to obtain a pretreated nanomica sheet; reacting the pretreated nanomica sheet, di(2-bromomethyl)phenylphosphine oxide, and piperazine to obtain a premodified nanomica sheet; reacting the premodified nanomica sheet and methyl iodide to obtain a modified nanomica sheet; and uniformly mixing the functionalized polyester, the distyryl crosslinking agent, the modified nanomica sheet, and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, and blow molding the mixture to obtain the high-barrier packaging material.

[0020] First, 5,12-tetrabenzoquinone and tetrabromomethane are reacted to produce an intermediate. The intermediate is then reacted with 4-(benzene acrylate)phenylboronic acid to produce a distyryl crosslinker. An α-β unsaturated carbonyl compound carbon-carbon double bond is introduced into the distyryl crosslinker. The α-β unsaturated carbonyl compound carbon-carbon double bond can undergo a Michael addition reaction with the amino group introduced on the side chain of the functionalized polyester molecule to form a crosslinked network structure. The crosslinked network structure can make the molecular chains more tightly arranged, inhibit the relative movement between the molecular chains, reduce the mobility of the molecular chains, thereby hindering the permeation of gas or liquid and improving the barrier properties of the high-barrier packaging material. The (5,12-distyryl) tetraacene structure in the distyryl crosslinker undergoes a photocyclization reaction under the action of ultraviolet light and a reverse ring-opening reaction under the action of visible light. This reversible ring-switching reaction can absorb the ultraviolet energy acting on the material and convert the ultraviolet energy into chemical energy, thereby improving the anti-aging properties of the high-barrier packaging material. The mechanism of action is as follows: .

[0021] Secondly, under the action of an initiator, 3-aminopropylene and allyl tris(trimethylsiloxy)silane are grafted onto the molecular side chains of polyethylene terephthalate through a free radical grafting reaction to produce a functionalized polyester, and siloxane chains and amino groups are introduced into the molecular side chains of the functionalized polyester. The siloxane chains decompose at high temperatures to produce silicon-oxygen free radicals, interrupting the combustion chain reaction and promoting carbonization. During combustion, a dense carbon layer is formed to isolate oxygen and improve the flame retardant properties of the barrier packaging material. The amino groups introduced into the molecular side chains of the functionalized polyester can undergo a Michael addition reaction with the carbon-carbon double bond of the α-β unsaturated carbonyl compound on the distyryl crosslinker to form a cross-linked network structure. The cross-linked network structure can make the molecular chains more tightly arranged, inhibit the relative movement between the molecular chains, reduce the activity of the molecular chains, thereby hindering the penetration of gas or liquid and improving the barrier properties of the high-barrier packaging material.

[0022] Finally, nanomica sheets and (3-bromopropyl)triethoxysilane were reacted to prepare pretreated nanomica sheets, and bromine atoms were introduced into the pretreated nanomica sheets. The bromine atoms on di(2-bromomethyl)phenylphosphine oxide reacted with piperazine and polymerized and grew on the pretreated nanomica sheets to prepare pre-modified nanomica sheets. Phosphorus and substituted piperazine were introduced into the pre-modified nanomica sheets. Existing research has shown that piperazine and its derivatives can be used for flame retardant modification of oxygen-rich polymers, which can promote condensation phase crosslinking and the formation of a carbon layer. In addition, piperazine contains nitrogen, which can serve as a potential source of non-flammable gas. The synergistic effect of phosphorus and substituted piperazine further improves the flame retardant properties of high-barrier packaging materials. The modified nanomica sheets are prepared by reacting the substituted piperazine on the pre-modified nanomica sheets with iodomethane, converting the substituted piperazine into a piperazine-based quaternary ammonium salt, and also improving the antibacterial properties of the high-barrier packaging material; the nanomica sheets have a lamellar structure, and the surface of the nanomica sheets is modified to enhance the compatibility of the nanomica sheets with polyester materials, so that the nanomica sheets can be evenly dispersed in the polyester matrix to form a parallel nano-level layered structure, forcing gas or water vapor molecules to diffuse along a tortuous path, significantly extending the penetration time, and further improving the barrier properties of the high-barrier packaging material. DETAILED DESCRIPTION

[0023] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] The polyethylene terephthalate used in the following examples and comparative examples is PETG Eastman GN119 from the United States, purchased from Shabit Plastic Trading (Suzhou) Co., Ltd.; the nano-mica flakes used have a silicon dioxide content of 42.63%, a magnesium content of 28.45%, and an active ingredient content of 99%, and were purchased from Lingshou County Xinjian Mineral Products Processing Plant.

[0025] Example 1: A method for preparing a high-barrier packaging material, comprising the following steps: (1) Tetrabromomethane and triphenylphosphine were added to toluene with a molar ratio of 1:2, stirred at 10°C and 300 r / min for 60 min, 5,12-tetrabenzoquinone with a molar ratio of 0.3 times the mass of tetrabromomethane was added, the temperature was raised to 108°C, stirred at 300 r / min and refluxed for 24 h, cooled to room temperature, filtered, and the filtrate was dried at 60°C for 12 h under vacuum to obtain an intermediate; deionized water, anhydrous ethanol, and toluene were added in a volume ratio of The intermediate and 4-(benzene acrylate)phenylboronic acid were evenly mixed in a molar ratio of 1:1:19 to prepare a mixed solvent; the intermediate and 4-(benzene acrylate)phenylboronic acid were added to a mixed solvent 24 times the mass of the intermediate in a molar ratio of 1:5, and potassium carbonate 2 times the mass of the intermediate and tetrakis(triphenylphosphine)palladium 0.1 times the mass of the intermediate were added, and the mixture was stirred and refluxed at 78°C and 300 r / min for 24 hours. The mixture was cooled to room temperature and filtered. The filtrate was dried at 60°C under vacuum conditions for 12 hours to prepare a distyryl crosslinker; (2) Benzoyl peroxide and N,N-dimethylformamide were mixed in a mass ratio of 1:4 to prepare an initiator solution; polyethylene terephthalate, 3-aminopropylene, allyl tris(trimethylsiloxy)silane, and N,N-dimethylformamide were mixed in a mass ratio of 1:0.4:0.3:6, and the initiator solution (1 times the mass of polyethylene terephthalate) was added dropwise at a constant speed within 30 minutes at 70°C and 100 r / min. After the addition was completed, the stirring reaction was continued for 3 hours, and N,N-dimethylformamide was removed by rotary evaporation. The mixture was washed with anhydrous ethanol for 3 times and dried at 50°C for 10 hours under vacuum conditions to obtain a functionalized polyester. (3) (3-Bromopropyl) triethoxysilane, 10% hydrochloric acid aqueous solution, deionized water and anhydrous ethanol were mixed in a mass ratio of 1:2:26:30, stirred at 10 ° C, 300 r / min for 30 min, added with nano-mica flakes 0.6 times the mass of (3-bromopropyl) triethoxysilane, stirred at 50 ° C, 300 r / min for 3 h, filtered, and dried at 65 ° C under vacuum conditions for 11 h to prepare pretreated nano-mica flakes; di(2-bromomethyl)phenylphosphine oxide and piperazine were added in a molar ratio of 1:1.2 to tetrahydrofuran 6 times the mass of piperazine to prepare a monomer mixture; pretreated mica flakes, triethylamine and tetrahydrofuran were mixed in a mass ratio of 1:1.2 to prepare a monomer mixture; :0.05:30 and evenly mixed, stirred at 10 ° C, 200r / min for 30min, and a monomer mixture of 20 times the mass of the pretreated mica sheet was uniformly added dropwise within 30min. After the addition was completed, the temperature was raised to 40 ° C, and the stirring reaction was continued for 6h, filtered, washed with anhydrous ethanol and deionized water 3 times each, and dried at 60 ° C for 12h under vacuum conditions to obtain a pre-modified nano mica sheet; the pre-modified nano mica sheet, iodomethane, and chloroform were mixed in a mass ratio of 1:2:20, stirred at 20 ° C, 200r / min for 35h under light-proof conditions, filtered, washed with anhydrous ethanol and deionized water 3 times each, and dried at 60 ° C for 12h under vacuum conditions to obtain a modified nano mica sheet; (4) According to the mass ratio, 98 parts of functionalized polyester, 8 parts of distyryl crosslinking agent, 2 parts of modified nano-mica flakes and 1 part of 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene were weighed; the functionalized polyester, distyryl crosslinking agent, modified nano-mica flakes and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene were mixed evenly and placed in an injection blow molding machine for blow molding. During the injection process, the material temperature was set to 255°C, the injection pressure was set to 110 MPa, the holding pressure was set to 50 MPa, the holding time was set to 10 s, the mold temperature was set to 85°C, and the mold was demoulded after cooling to room temperature to obtain a high barrier packaging material.

[0026] Example 2: A method for preparing a high-barrier packaging material, comprising the following steps: (1) Tetrabromomethane and triphenylphosphine were added to toluene (11 times the mass of tetrabromomethane) in a molar ratio of 1:2, stirred at 20°C and 350 r / min for 55 min, 5,12-tetrabenzoquinone (0.35 times the mass of tetrabromomethane) was added, the temperature was raised to 109°C, stirred at 350 r / min and refluxed for 23 h, cooled to room temperature, filtered, and the filtrate was dried at 65°C under vacuum for 11 h to obtain an intermediate; deionized water, anhydrous ethanol, and toluene were added in a volume ratio of 1:2. :1:20 and mixed evenly to prepare a mixed solvent; the intermediate and 4-(acrylic acid benzyl)phenylboronic acid were added to a mixed solvent 25 times the mass of the intermediate in a molar ratio of 1:5.5, and potassium carbonate 2.1 times the mass of the intermediate and tetrakis(triphenylphosphine)palladium 0.11 times the mass of the intermediate were added, and the mixture was stirred and refluxed at 80°C and 350r / min for 23h, cooled to room temperature, filtered, and the filtrate was dried at 65°C under vacuum for 11h to obtain a distyryl crosslinker; (2) Benzoyl peroxide and N,N-dimethylformamide were mixed evenly at a mass ratio of 1:4.5 to prepare an initiator solution; polyethylene terephthalate, 3-aminopropylene, allyl tris(trimethylsiloxy)silane, and N,N-dimethylformamide were mixed evenly at a mass ratio of 1:0.45:0.35:7, and under stirring conditions of 75°C and 150 r / min, the initiator solution of 1.1 times the mass of polyethylene terephthalate was added dropwise at a constant speed within 30 minutes. After the addition was completed, the stirring reaction was continued for 2.5 hours, and N,N-dimethylformamide was removed by rotary evaporation. The mixture was washed with anhydrous ethanol 4 times and dried at 55°C under vacuum conditions for 9 hours to obtain a functionalized polyester. (3) (3-Bromopropyl) triethoxysilane, 10% hydrochloric acid aqueous solution, deionized water and anhydrous ethanol were mixed in a mass ratio of 1:2.5:28:32, stirred at 20 ° C, 400 r / min for 25 min, and nano-mica flakes with a mass of 0.7 times that of (3-bromopropyl) triethoxysilane were added. The mixture was stirred at 55 ° C, 400 r / min for 2.5 h, filtered, and dried at 70 ° C under vacuum conditions for 10 h to obtain pretreated nano-mica flakes; di(2-bromomethyl)phenylphosphine oxide and piperazine were added in a molar ratio of 1:1.25 to tetrahydrofuran with a mass of 7 times that of piperazine to prepare a monomer mixture; the pretreated mica flakes, triethylamine and tetrahydrofuran were mixed in a mass ratio of 1:1.25 ... :0.06:35 and mixed evenly, stirred at 20 ° C, 250r / min for 25 minutes, and the monomer mixture of 21 times the mass of the pretreated mica sheet was uniformly added dropwise within 30 minutes. After the addition was completed, the temperature was raised to 45 ° C, and the stirring reaction was continued for 5.5 hours. Filtered, washed with anhydrous ethanol and deionized water 4 times each, and dried at 65 ° C for 11 hours under vacuum conditions to obtain pre-modified nano mica sheets; the pre-modified nano mica sheets, iodomethane, and chloroform were mixed evenly in a mass ratio of 1:2.5:22, stirred at 25 ° C, 250r / min for 34 hours under light-proof conditions, filtered, washed with anhydrous ethanol and deionized water 4 times each, and dried at 65 ° C for 11 hours under vacuum conditions to obtain modified nano mica sheets; (4) According to the mass ratio, 99 parts of functionalized polyester, 9 parts of distyryl crosslinking agent, 2.5 parts of modified nano-mica flakes and 1.2 parts of 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene were weighed; the functionalized polyester, distyryl crosslinking agent, modified nano-mica flakes and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene were mixed evenly and placed in an injection blow molding machine for blow molding. During the injection process, the material temperature was set to 260°C, the injection pressure was set to 115 MPa, the holding pressure was set to 55 MPa, the holding time was set to 9 s, the mold temperature was set to 90°C, and the mold was demoulded after cooling to room temperature to obtain a high barrier packaging material.

[0027] Example 3: A method for preparing a high-barrier packaging material, comprising the following steps: (1) Tetrabromomethane and triphenylphosphine were added to toluene (12 times the mass of tetrabromomethane) in a molar ratio of 1:2, stirred at 30°C and 400 r / min for 50 min, 5,12-tetrabenzoquinone (0.4 times the mass of tetrabromomethane) was added, the temperature was raised to 110°C, stirred and refluxed at 400 r / min for 22 h, cooled to room temperature, filtered, and the filtrate was dried at 70°C for 10 h under vacuum to obtain an intermediate; deionized water, anhydrous ethanol, and toluene were added in a volume ratio of 1:2. The intermediate and 4-(benzene acrylate)phenylboronic acid were evenly mixed in a molar ratio of 1:1:21 to prepare a mixed solvent; the intermediate and 4-(benzene acrylate)phenylboronic acid were added to a mixed solvent 26 times the mass of the intermediate in a molar ratio of 1:6, and potassium carbonate 2.2 times the mass of the intermediate and tetrakis(triphenylphosphine)palladium 0.12 times the mass of the intermediate were added, and the mixture was stirred and refluxed at 82°C and 400 r / min for 22 hours. The mixture was cooled to room temperature and filtered. The filtrate was dried under vacuum at 70°C for 10 hours to prepare a distyryl crosslinker; (2) Benzoyl peroxide and N,N-dimethylformamide were mixed in a mass ratio of 1:5 to prepare an initiator solution; polyethylene terephthalate, 3-aminopropylene, allyl tris(trimethylsiloxy)silane, and N,N-dimethylformamide were mixed in a mass ratio of 1:0.5:0.4:8, and the initiator solution (1.2 times the mass of polyethylene terephthalate) was added dropwise at a constant speed within 30 minutes at 80°C and 200 r / min stirring conditions. After the addition was completed, the stirring reaction was continued for 2 hours, and N,N-dimethylformamide was removed by rotary evaporation. The mixture was washed with anhydrous ethanol for 5 times and dried at 60°C under vacuum conditions for 8 hours to obtain a functionalized polyester. (3) (3-Bromopropyl) triethoxysilane, 10% hydrochloric acid aqueous solution, deionized water and anhydrous ethanol were mixed in a mass ratio of 1:3:30:34, stirred at 30°C and 500 r / min for 20 min, and nano-mica flakes with a mass fraction of 0.8 times that of (3-bromopropyl) triethoxysilane were added, stirred at 60°C and 500 r / min for 2 h, filtered, and dried at 75°C under vacuum for 9 h to obtain pretreated nano-mica flakes; di(2-bromomethyl)phenylphosphine oxide and piperazine were added in a molar ratio of 1:1.3 to tetrahydrofuran with a mass fraction of 8 times that of piperazine to prepare a monomer mixture; pretreated mica flakes, triethylamine and tetrahydrofuran were mixed in a mass ratio of 1: 0.07:40 was mixed evenly, stirred at 30°C and 300r / min for 20min, and a monomer mixture of 22 times the mass of the pretreated mica sheet was uniformly added dropwise within 30min. After the addition was completed, the temperature was raised to 50°C, and the stirring reaction was continued for 5h. The mixture was filtered, washed with anhydrous ethanol and deionized water 5 times each, and dried at 70°C for 10h under vacuum conditions to obtain a pre-modified nano mica sheet; the pre-modified nano mica sheet, iodomethane, and chloroform were mixed evenly in a mass ratio of 1:3:24, stirred at 30°C and 300r / min for 33h under light-proof conditions, filtered, washed with anhydrous ethanol and deionized water 5 times each, and dried at 70°C for 10h under vacuum conditions to obtain a modified nano mica sheet; (4) According to the mass parts, 100 parts of functionalized polyester, 10 parts of distyryl crosslinking agent, 3 parts of modified nano-mica flakes, and 1.4 parts of 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene were weighed; the functionalized polyester, distyryl crosslinking agent, modified nano-mica flakes, and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene were mixed evenly, placed in an injection blow molding machine for blow molding, and the injection process was set to have a material temperature of 265°C, an injection pressure of 120 MPa, a holding pressure of 60 MPa, a holding time of 8 s, and a mold temperature of 95°C. After cooling to room temperature, the mold was demoulded to obtain a high barrier packaging material.

[0028] Comparative Example 1: The method for preparing the high-barrier packaging material of Comparative Example 1 differs from that of Example 2 in that step (1) is omitted and step (4) is modified as follows: 99 parts by mass of functionalized polyester, 2.5 parts of modified nano-mica flakes, and 1.2 parts of 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene are weighed; the functionalized polyester, modified nano-mica flakes, and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene are uniformly mixed, and the mixture is placed in an injection blow molding machine for blow molding. During the injection process, the material temperature is set to 260°C, the injection pressure is set to 115 MPa, the holding pressure is set to 55 MPa, the holding time is set to 9 s, the mold temperature is set to 90°C, and the mixture is demoulded after cooling to room temperature to obtain the high-barrier packaging material. The remaining steps are the same as those of Example 2.

[0029] Comparative Example 2: The method for preparing the high-barrier packaging material in Comparative Example 2 differs from that in Example 2 in that step (2) is omitted and step (4) is modified as follows: 99 parts of polyethylene terephthalate, 9 parts of distyryl crosslinking agent, 2.5 parts of modified nano-mica flakes, and 1.2 parts of 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene are weighed by mass; the polyethylene terephthalate, distyryl crosslinking agent, modified nano-mica flakes, and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene are uniformly mixed and placed in an injection blow molding machine for blow molding. During the injection process, the material temperature is set to 260°C, the injection pressure is set to 115 MPa, the holding pressure is set to 55 MPa, the holding time is set to 9 s, the mold temperature is set to 90°C, and the mold is demoulded after cooling to room temperature to obtain the high-barrier packaging material. The remaining steps are the same as those in Example 2.

[0030] Comparative Example 3: The preparation method of the high barrier packaging material of Comparative Example 3 differs from that of Example 2 only in step (3). Step (3) is modified as follows: (3-bromopropyl) triethoxysilane, a 10% hydrochloric acid aqueous solution, deionized water, and anhydrous ethanol are uniformly mixed in a mass ratio of 1:2.5:28:32, stirred at 20°C and 400 r / min for 25 min, nano-mica flakes with a mass 0.7 times that of (3-bromopropyl) triethoxysilane are added, stirred at 55°C and 400 r / min for 2.5 h, filtered, and dried at 70°C under vacuum for 10 h to obtain pretreated nano-mica flakes. Di(2-bromomethyl)phenylphosphine oxide and piperazine were added to tetrahydrofuran (7 times the mass of piperazine) at a molar ratio of 1:1.25 to prepare a monomer mixture. Pretreated mica flakes, triethylamine, and tetrahydrofuran were mixed uniformly at a mass ratio of 1:0.06:35, stirred at 250 rpm at 20°C for 25 minutes, and the monomer mixture (21 times the mass of the pretreated mica flakes) was added dropwise at a constant rate over 30 minutes. After the addition was complete, the temperature was raised to 45°C, and the reaction was continued with stirring for 5.5 hours. The mixture was filtered, washed four times with anhydrous ethanol and four times with deionized water, and dried at 65°C under vacuum for 11 hours to produce modified nano-mica flakes. The remaining steps were the same as in Example 2.

[0031] Comparative Example 4: The method for preparing the high-barrier packaging material in Comparative Example 4 differs from that in Example 2 in that step (3) is omitted and step (4) is modified as follows: 99 parts of functionalized polyester, 9 parts of distyryl crosslinking agent, 2.5 parts of nano-mica flakes, and 1.2 parts of 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene are weighed by mass; the functionalized polyester, distyryl crosslinking agent, nano-mica flakes, and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene are uniformly mixed and placed in an injection blow molding machine for blow molding. During the injection process, the material temperature is set to 260°C, the injection pressure is set to 115 MPa, the holding pressure is set to 55 MPa, the holding time is set to 9 s, the mold temperature is set to 90°C, and the mold is demoulded after cooling to room temperature to obtain the high-barrier packaging material. The remaining steps are the same as those in Example 2.

[0032] Test Example 1 Barrier performance testing Test Method: Water Vapor Transmission Rate (WVTR) tests were conducted on the Examples and Comparative Examples using an AQUATRAN 3 / 38H system. Test conditions were 38.0°C and 90.0% relative humidity. Results are shown in Table 1.

[0033] Table 1

[0034] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 4 in Table 1, it can be found that the high barrier packaging material prepared in the present invention has good barrier properties.

[0035] By comparison, the water vapor transmission rates of Examples 1 to 3 are lower than that of Comparative Example 1, indicating that an intermediate is prepared by reacting 5,12-tetraacenoquinone and tetrabromomethane; a distyryl crosslinker is prepared by reacting the intermediate with 4-(benzene acrylate)phenylboronic acid; and an α-β-unsaturated carbonyl compound carbon-carbon double bond is introduced into the distyryl crosslinker. The α-β-unsaturated carbonyl compound carbon-carbon double bond can undergo a Michael addition reaction with the amino group introduced on the side chain of the functionalized polyester molecule to form a crosslinked network structure. The crosslinked network structure can make the molecular chains more densely arranged, inhibit the relative movement between the molecular chains, reduce the mobility of the molecular chains, thereby hindering the permeation of gas or liquid, and improving the barrier properties of the high-barrier packaging material.

[0036] By comparison, the water vapor transmission rates of Examples 1 to 3 are lower than that of Comparative Example 2, indicating that, under the action of an initiator, 3-aminopropylene and allyltris(trimethylsiloxy)silane are grafted onto the molecular side chains of polyethylene terephthalate via a free radical grafting reaction to produce a functionalized polyester, introducing amino groups into the molecular side chains of the functionalized polyester. The amino groups introduced into the molecular side chains of the functionalized polyester can undergo a Michael addition reaction with the carbon-carbon double bonds of the α-β unsaturated carbonyl compound on the distyryl crosslinker to form a crosslinked network structure. This crosslinked network structure can more densely arrange the molecular chains, inhibit relative movement between the molecular chains, and reduce the mobility of the molecular chains, thereby hindering the permeation of gases or liquids and improving the barrier properties of the high-barrier packaging material.

[0037] By comparison, the water vapor transmission rates of Examples 1 to 3 are lower than that of Comparative Example 4, indicating that the nano-mica flakes have a lamellar structure, but are prone to agglomeration and uneven dispersion when directly added to the polyester material. Surface modification of the nano-mica flakes enhances their compatibility with the polyester material, allowing them to be evenly dispersed in the polyester matrix, forming a parallel nano-scale layered structure. This forces gas or water vapor molecules to diffuse along a tortuous path, significantly prolonging the permeation time and further improving the barrier properties of the high-barrier packaging material.

[0038] Test Example 2 Flame retardant performance test Test method: The examples and comparative examples were prepared into standard specimens according to GB / T 2406, and the limiting oxygen index of the standard specimens was tested. The results are shown in Table 2.

[0039] Table 2

[0040] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 4 in Table 2, it can be found that the high barrier packaging material prepared in the present invention has good flame retardant properties.

[0041] By comparison, the limiting oxygen index of Examples 1-3 is greater than that of Comparative Example 2, indicating that, under the action of an initiator, 3-aminopropylene and allyltris(trimethylsiloxy)silane are grafted onto the molecular side chains of polyethylene terephthalate via a free radical grafting reaction to produce a functionalized polyester, introducing siloxane chains onto the molecular side chains of the functionalized polyester. Siloxane chains decompose at high temperatures to produce silicon-oxygen free radicals, interrupting the combustion chain reaction and promoting carbonization. During combustion, a dense carbon layer is formed to isolate oxygen, thereby improving the flame retardant properties of the barrier packaging material.

[0042] By comparison, the limiting oxygen index of Examples 1 to 3 is greater than that of Comparative Example 4, indicating that bromine atoms are introduced into the pretreated nanomica sheets by reacting the nanomica sheets with (3-bromopropyl)triethoxysilane; the bromine atoms on di(2-bromomethyl)phenylphosphine oxide react with piperazine, and polymerize and grow on the pretreated nanomica sheets to prepare pre-modified nanomica sheets; phosphorus and substituted piperazine are introduced into the pre-modified nanomica sheets; existing research indicates that piperazine and its derivatives can be used for flame retardant modification of oxygen-rich polymers, promoting crosslinking of the condensation phase and the formation of a char layer. In addition, piperazine contains nitrogen, which can serve as a potential source of non-flammable gas. The synergistic effect of phosphorus and substituted piperazine further enhances the flame retardant properties of the high-barrier packaging material.

[0043] Test Example 3 Antibacterial performance testing Test Method: The antibacterial properties of the Examples and Comparative Examples were tested according to the method of QB / T2591-2003. The test bacteria was Escherichia coli. The results are shown in Table 3.

[0044] Table 3

[0045] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 4 in Table 3, it can be found that the high barrier packaging material prepared in the present invention has good antibacterial properties.

[0046] By comparison, the antibacterial rates of Examples 1 to 3 are greater than those of Comparative Examples 3 to 4, indicating that a pretreated nanomica sheet is prepared by reacting the nanomica sheet and (3-bromopropyl)triethoxysilane, and a bromine atom is introduced into the pretreated nanomica sheet; the bromine atom on di(2-bromomethyl)phenylphosphine oxide reacts with piperazine, and polymerizes and grows on the pretreated nanomica sheet to prepare a pre-modified nanomica sheet; a substituted piperazine is introduced into the pre-modified nanomica sheet; the substituted piperazine on the pre-modified nanomica sheet is reacted with methyl iodide to prepare a modified nanomica sheet, and the substituted piperazine is converted into a piperazine-based quaternary ammonium salt. The piperazine-based quaternary ammonium salt has a structure similar to that of a cationic antibacterial agent and can improve the antibacterial properties of high-barrier packaging materials.

[0047] Test Example 4 Anti-aging performance test Test method: According to GB / T1040, the examples and comparative examples were prepared into standard specimens, and the tensile strength P of the standard specimens was tested. The standard specimens were placed in a UV lamp aging test box and irradiated with UV lamp for 21 days with a radiation intensity of 0.51W / m 2 (340nm), the tensile strength Q was tested, and the performance retention rate of the embodiment and the comparative example after UV aging treatment was calculated: performance retention rate = Q / P × 100%. The results are shown in Table 4.

[0048] Table 4

[0049] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 4 in Table 3, it can be found that the high barrier packaging material prepared in the present invention has good anti-aging performance.

[0050] By comparison, the performance retention rates of Examples 1 to 3 are greater than that of Comparative Example 1, indicating that an intermediate is prepared by reacting 5,12-tetrabenzoquinone and tetrabromomethane; and a distyryl crosslinker is prepared by reacting the intermediate and 4-(benzene acrylate)phenylboronic acid. The (5,12-distyryl)tetraacene structure in the distyryl crosslinker undergoes a photocyclization reaction under the action of ultraviolet light and a reverse ring-opening reaction under the action of visible light. This reversible ring-opening reaction can absorb ultraviolet energy acting on the material and convert the ultraviolet light energy into chemical energy, thereby improving the anti-aging properties of the high-barrier packaging material.

[0051] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A high barrier packaging material, characterized in that: The high-barrier packaging material is prepared by reacting an intermediate with 4-(benzene acrylate)phenylboronic acid to obtain a distyryl crosslinking agent; reacting pre-modified nanomica sheets with methyl iodide to obtain modified nanomica sheets; and uniformly mixing functionalized polyester, the distyryl crosslinking agent, the modified nanomica sheets, and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, and blow molding the mixture. The intermediate is prepared by reacting 5,12-tetraacenoquinone and tetrabromomethane; The functionalized polyester is prepared by reacting polyethylene terephthalate, 3-aminopropylene, and allyl tris(trimethylsiloxy)silane; The pre-modified nano-mica sheet is prepared by reacting pre-treated nano-mica sheet, di(2-bromomethyl)phenylphosphine oxide and piperazine; The pretreated nano-mica sheet is prepared by reacting the nano-mica sheet and (3-bromopropyl)triethoxysilane.

2. A method for preparing a high barrier packaging material, characterized in that: The preparation method of the high barrier packaging material comprises the following preparation steps: (1) The intermediate and 4-(benzene acrylate)phenylboronic acid are added to a mixed solvent with a molar ratio of 1:(5-6) to 24-26 times the mass of the intermediate, and potassium carbonate with a mass of 2-2.2 times the mass of the intermediate and tetrakis(triphenylphosphine)palladium with a mass of 0.1-0.12 times the mass of the intermediate are added. The mixture is stirred and refluxed at 78-82°C and 300-400 r / min for 22-24 hours. The mixture is cooled to room temperature and filtered. The filtrate is dried under vacuum at 60-70°C for 10-12 hours to obtain a distyryl crosslinking agent. (2) Polyethylene terephthalate, 3-aminopropylene, allyl tris(trimethylsiloxy)silane, and N,N-dimethylformamide are mixed uniformly in a mass ratio of 1:(0.4~0.5):(0.3~0.4):(6~8). Under stirring conditions of 70~80℃ and 100~200r / min, an initiator solution of 1~1.2 times the mass of polyethylene terephthalate is added dropwise at a uniform rate within 30min. After the addition is completed, the stirring reaction is continued for 2~3h. N,N-dimethylformamide is removed by rotary evaporation, and the mixture is washed with anhydrous ethanol for 3~5 times. The mixture is dried at 50~60℃ under vacuum conditions for 8~10h to obtain a functionalized polyester. (3) The pre-modified nano-mica flakes, iodomethane and chloroform were mixed uniformly in a mass ratio of 1:(2-3):(20-24), stirred at 200-300 r / min at 20-30 ° C under light-proof conditions for 33-35 h, filtered, washed with anhydrous ethanol and deionized water 3-5 times each, and dried at 60-70 ° C under vacuum conditions for 10-12 h to obtain modified nano-mica flakes; (4) Weigh 98-100 parts of functionalized polyester, 8-10 parts of distyryl crosslinking agent, 2-3 parts of modified nano-mica flakes, and 1-1.4 parts of 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene by mass; mix the functionalized polyester, distyryl crosslinking agent, modified nano-mica flakes, and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene evenly, place the mixture in an injection blow molding machine for blow molding, and demold after cooling to room temperature to obtain a high barrier packaging material.

3. The method for preparing a high barrier packaging material according to claim 2, characterized in that: The preparation method of the intermediate in step (1) is as follows: tetrabromomethane and triphenylphosphine are added in a molar ratio of 1:2 to toluene with a mass of 10 to 12 times that of tetrabromomethane, stirred at 10 to 30°C and 300 to 400 r / min for 50 to 60 min, 5,12-tetrabenzoquinone with a mass of 0.3 to 0.4 times that of tetrabromomethane is added, the temperature is raised to 108 to 110°C, stirred and refluxed at 300 to 400 r / min for 22 to 24 h, cooled to room temperature, filtered, and the filtrate is dried at 60 to 70°C under vacuum conditions for 10 to 12 h to obtain the intermediate.

4. The method for preparing a high barrier packaging material according to claim 2, characterized in that: The preparation method of the mixed solvent in step (1) is as follows: deionized water, anhydrous ethanol and toluene are uniformly mixed in a volume ratio of 1:1:(19-21) to prepare a mixed solvent.

5. The method for preparing a high barrier packaging material according to claim 2, characterized in that: The polyethylene terephthalate model in step (2) is PETG Eastman GN119 from the United States.

6. The method for preparing a high barrier packaging material according to claim 2, characterized in that: The preparation method of the initiator solution in step (2) is as follows: benzoyl peroxide and N,N-dimethylformamide are uniformly mixed in a mass ratio of 1:(4~5) to prepare an initiator solution.

7. The method for preparing a high barrier packaging material according to claim 2, characterized in that: The preparation method of the pre-modified nano-mica sheet in step (3) is as follows: pre-treated nano-mica sheet, triethylamine and tetrahydrofuran are mixed uniformly in a mass ratio of 1: (0.05-0.07): (30-40), stirred at 10-30°C and 200-300 r / min for 20-30 min, and a monomer mixture of 20-22 times the mass of the pre-treated nano-mica sheet is added dropwise at a uniform rate within 30 min. After the addition is completed, the temperature is raised to 40-50°C, the stirring reaction is continued for 5-6 h, filtered, washed with anhydrous ethanol and deionized water for 3-5 times each, and dried at 60-70°C under vacuum conditions for 10-12 h to obtain the pre-modified nano-mica sheet.

8. The method for preparing a high barrier packaging material according to claim 7, characterized in that: The monomer mixture is prepared by adding di(2-bromomethyl)phenylphosphine oxide and piperazine in a molar ratio of 1:(1.2-1.3) to tetrahydrofuran (6-8 times the mass of piperazine) to prepare the monomer mixture.

9. The method for preparing a high barrier packaging material according to claim 7, characterized in that: The preparation method of the pretreated nano-mica sheet comprises the following steps: uniformly mixing (3-bromopropyl)triethoxysilane, a hydrochloric acid aqueous solution with a mass fraction of 10%, deionized water, and anhydrous ethanol in a mass ratio of 1:(2-3):(26-30):(30-34), stirring at 10-30° C. and 300-500 r / min for 20-30 min, adding nano-mica sheets with a mass of 0.6-0.8 times that of (3-bromopropyl)triethoxysilane, stirring at 50-60° C. and 300-500 r / min for reaction for 2-3 h, filtering, and drying at 65-75° C. under vacuum conditions for 9-11 h to obtain the pretreated nano-mica sheet.

10. The method for preparing a high barrier packaging material according to claim 2, characterized in that: The process parameters of the blow molding in step (4) are as follows: during the injection process, the material temperature is set to 255~265℃, the injection pressure is set to 110~120MPa, the holding pressure is set to 50~60MPa, the holding time is set to 8~10s, and the mold temperature is set to 85~95℃.

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