A PET packaging material

Abstract

The application relates to a PET packaging material and belongs to the technical field of packaging materials; the application is characterized in that the surface of nano-silicon dioxide is grafted with polymerizable anhydride groups through modification, the anhydride groups can react with the terminal hydroxyl groups of PET oligomers, the chemical bonding between the nano-silicon dioxide and the PET groups is established, the compatibility of the nano-silicon dioxide in the PET is effectively improved, the crystallization distribution is optimized, the stress transmission efficiency in the material is improved, the tensile strength and the impact resistance of the PET packaging material are effectively improved, in addition, the surface of the modified nano-silicon dioxide also has a positively charged pyridine group quaternary ammonium salt structure, the surface resistance of the PET packaging material can be effectively reduced, the electrostatic hazard is reduced, and the PET packaging material is provided with good antibacterial performance.

Description

Technical Field

[0001] This invention belongs to the field of packaging material technology, specifically, it relates to a PET packaging material, and more specifically, it relates to a medical antibacterial and antistatic packaging material. Background Technology

[0002] Polyethylene terephthalate (PET) is widely used in medical packaging materials due to its excellent physical and mechanical properties, chemical stability, and good gas barrier properties. Compared with traditional glass packaging, PET has the advantages of being lightweight and impact-resistant. However, PET is a polar insulating material with high surface resistance. During processing, transportation, or use, it is prone to static electricity due to friction. The static electricity generated on the surface can attract dust, bacteria, and other contaminants, which not only affects the cleanliness of the packaging but may also lead to the risk of microbial contamination of pharmaceuticals. Although the surface resistance of PET material can be reduced and its antistatic properties improved by adding antistatic agents, the migration of antistatic agents can damage the chemical stability of PET, which may affect the safety performance of pharmaceuticals. In addition, PET does not have antibacterial properties and cannot inhibit the growth of microorganisms. In humid environments, the surface of PET is more susceptible to microbial contamination. To solve the above technical defects, this invention prepares a PET packaging material with good antibacterial and antistatic properties. Summary of the Invention

[0003] The purpose of this invention is to provide a PET packaging material to solve the problems mentioned in the background art.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] A PET packaging material is prepared by the following steps:

[0006] S1. Mix silane coupling agent KH-431, nano-silica, and ethanol solution in a three-necked flask, attach a condenser and a thermometer, turn on magnetic stirring, add glacial acetic acid to the three-necked flask to adjust the pH of the system to 4-5, and then react at a temperature of 40-80℃ for 4-24 hours. After the reaction is completed, filter out the nano-silica and wash it with anhydrous ethanol and deionized water in sequence, and then dry it to obtain chloropropylated nano-silica.

[0007] S2. Chloropropylated nano silica, 4-methylfurano[3,4-b]pyridine-5,7-dione, and acetonitrile were mixed in a three-necked flask, fitted with a condenser and a thermometer, and magnetic stirring was turned on. The mixture was reacted at 60-82℃ for 8-16 hours. After the reaction was completed, the nano silica was filtered out and washed with anhydrous ethanol and deionized water in sequence, and then dried to obtain modified nano silica.

[0008] S3. Terephthalic acid, ethylene glycol, catalyst, and heat stabilizer are added to a stainless steel reactor under nitrogen protection and polymerized at 220-240℃ for 4-5 hours to obtain PET oligomers. Then, modified nano-silica is added to the stainless steel reactor, and the pressure inside the stainless steel reactor is reduced to below 1 kPa. Polycondensation is completed at 270-290℃ for 4-6 hours. After the reaction is completed, the product is cooled to room temperature, granulated, and dried to obtain modified PET masterbatch.

[0009] S4. Modified PET masterbatch and antioxidant are mixed and added to a twin-screw extruder for melt extrusion, followed by blow molding to obtain the PET packaging material.

[0010] Furthermore, the silane coupling agent kh-431 is 3-chloropropyltrimethoxysilane.

[0011] Furthermore, the particle size of the nano-silica is 50–150 nm.

[0012] Furthermore, the ethanol solution is an aqueous solution of ethanol with a volume fraction of 60-80%.

[0013] Furthermore, the catalyst is one of antimony glycolate or antimony trioxide.

[0014] Furthermore, the heat stabilizer is one of triethyl phosphate or triphenyl phosphate.

[0015] Furthermore, the antioxidant is one of antioxidant 1010 and antioxidant 168.

[0016] Furthermore, the mass ratio of silane coupling agent KH-431, nano-silica, and ethanol solution in S1 is 8–12:10–12:250–400.

[0017] Furthermore, the mass ratio of chloropropylated nano-silica, 4-methylfurano[3,4-b]pyridine-5,7-dione, and acetonitrile in S2 is 12-15:7.2-9.4:100-160.

[0018] Furthermore, the mass ratio of terephthalic acid, ethylene glycol, catalyst, heat stabilizer, and modified nano-silica in S3 is 83–99: 42–66: 0.025–0.08: 0.125–0.625: 12–16.

[0019] Furthermore, the mass ratio of modified PET masterbatch to antioxidant in S4 is 100–120: 0.2–0.5.

[0020] Furthermore, the extrusion temperature of the twin-screw extruder in S4 is 270–290°C.

[0021] The beneficial effects of this invention are:

[0022] 1) This invention grafts silane coupling agent KH-431 onto the surface of nano-silica, introduces chloropropyl groups onto the surface of nano-silica, and then utilizes the chlorine atoms of the chloropropylated nano-silica and the nitrogen atoms on the pyridine ring of 4-methylfurano[3,4-b]pyridine-5,7-dione to undergo a quaternary ammonium salt reaction to obtain a modified nano-silica. The surface of unmodified nano-silica is rich in hydrophilic hydroxyl groups, which have poor compatibility with hydrophobic PET. Direct addition to PET may lead to agglomeration and stress concentration due to poor dispersibility, which significantly reduces the tensile properties and impact strength of PET. However, this invention modifies the surface of nano-silica by grafting polymerizable anhydride groups, which can react with the terminal hydroxyl groups of PET oligomers to establish chemical bonds between nano-silica and PET groups, optimize crystal distribution, improve stress transfer efficiency inside the material, and effectively improve the tensile strength and impact resistance of PET packaging materials.

[0023] 2) The modified nano-silica of the present invention has a pyridyl quaternary ammonium salt structure grafted on its surface. The pyridyl quaternary ammonium salt has a good bactericidal effect, which can give PET packaging materials long-lasting antibacterial properties. It can also form a conductive path in the PET substrate by utilizing its own positive charge, reducing the surface resistance of the material and improving the antistatic properties of PET packaging materials. Moreover, the antibacterial and antistatic components are combined in the PET material in the form of chemical bonds, so there is no risk of migration during use and it will not damage the chemical stability of PET. Detailed Implementation

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0025] In this article, the technical features described in an open-ended manner include both closed technical solutions composed of the listed features and open technical solutions that include the listed features.

[0026] As used herein, the term "and / or" includes any and all combinations of one or more of the related listed items.

[0027] In this document, numerical ranges are referred to as continuous unless otherwise specified, and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when a range refers to an integer, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0028] In this article, when referring to units for data ranges, if the unit is only followed by the right endpoint, it indicates that the units for the left and right endpoints are the same. For example, 220~240℃ means that the units for the left endpoint "220" and the right endpoint "240" are both in degrees Celsius.

[0029] This document only specifically discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, just as any upper limit can be combined with any other upper limit to form an unspecified range. Furthermore, each individually disclosed point or single value can itself serve as a lower or upper limit and be combined with any other point or single value or with other lower or upper limits to form an unspecified range.

[0030] Example 1

[0031] A PET packaging material is prepared by the following steps:

[0032] S1. By mass, 12 parts of silane coupling agent KH-431, 12 parts of nano-silica with a particle size of 50-150 nm, and 400 parts of 60% ethanol aqueous solution were mixed in a three-necked flask. A condenser and a thermometer were installed, and a magnetic stirrer was turned on. Glacial acetic acid was added to the three-necked flask to adjust the pH of the system to 4. The reaction was then carried out at 40°C for 24 hours. After the reaction was completed, the nano-silica was filtered out and washed with anhydrous ethanol and deionized water in sequence, and then dried to obtain chloropropylated nano-silica.

[0033] S2. By mass, 15 parts of chloropropylated nano silica, 9.4 parts of 4-methylfurano[3,4-b]pyridine-5,7-dione, and 160 parts of acetonitrile were mixed in a three-necked flask, fitted with a condenser and a thermometer, and the magnetic stirring was turned on. The mixture was reacted at 60°C for 16 hours. After the reaction was completed, the nano silica was filtered out and washed with anhydrous ethanol and deionized water in sequence, and then dried to obtain modified nano silica.

[0034] S3. By mass, 99 parts of terephthalic acid, 66 parts of ethylene glycol, 0.08 parts of antimony trioxide, and 0.625 parts of triphenyl phosphate were added to a stainless steel reactor under nitrogen protection and polymerized at 220°C for 5 hours to obtain PET oligomers. Then, 16 parts of modified nano-silica were added to the stainless steel reactor, and the pressure inside the stainless steel reactor was evacuated to 900 Pa. Polycondensation was completed at 270°C for 6 hours. After the reaction was completed, the product was cooled to room temperature, granulated, and dried to obtain modified PET masterbatch.

[0035] S4. By mass, 120 parts of modified PET masterbatch and 0.5 parts of antioxidant 1010 are mixed and added to a twin-screw extruder. After melt extrusion at a temperature of 270°C, the mixture is blow-molded to obtain the PET packaging material.

[0036] Example 2

[0037] A PET packaging material is prepared by the following steps:

[0038] S1. By mass, 10 parts of silane coupling agent KH-431, 11 parts of nano-silica with a particle size of 50-150 nm, and 325 parts of 70% ethanol aqueous solution were mixed in a three-necked flask. A condenser and a thermometer were installed, and a magnetic stirrer was turned on. Glacial acetic acid was added to the three-necked flask to adjust the pH of the system to 4.5. The reaction was then carried out at 60°C for 12 hours. After the reaction was completed, the nano-silica was filtered out and washed with anhydrous ethanol and deionized water in sequence, and then dried to obtain chloropropylated nano-silica.

[0039] S2. By mass, 13.5 parts of chloropropylated nano silica, 8.3 parts of 4-methylfurano[3,4-b]pyridine-5,7-dione, and 130 parts of acetonitrile were mixed in a three-necked flask, fitted with a condenser and a thermometer, and the magnetic stirring was turned on. The mixture was reacted at 71°C for 12 hours. After the reaction was completed, the nano silica was filtered out and washed with anhydrous ethanol and deionized water in sequence, and then dried to obtain modified nano silica.

[0040] S3. By mass, 91 parts of terephthalic acid, 54 parts of ethylene glycol, 0.0525 parts of antimony glycolate or antimony trioxide, and 0.375 parts of triethyl phosphate or triphenyl phosphate were added to a stainless steel reactor under nitrogen protection and polymerized at 230℃ for 4.5 h to obtain PET oligomer. Then, 14 parts of modified nano-silica were added to the stainless steel reactor, and the pressure inside the stainless steel reactor was reduced to 500 Pa. Polycondensation was completed at 280℃ for 5 h. After the reaction was completed, the product was cooled to room temperature, granulated and dried to obtain modified PET masterbatch.

[0041] S4. By mass, 110 parts of modified PET masterbatch and 0.35 parts of antioxidant 168 are mixed and added to a twin-screw extruder. After melt extrusion at a temperature of 280°C, the PET packaging material is obtained by blow molding.

[0042] Example 3

[0043] A PET packaging material is prepared by the following steps:

[0044] S1. By mass, 8 parts of silane coupling agent KH-431, 10 parts of nano-silica with a particle size of 50-150 nm, and 250 parts of 80% ethanol aqueous solution were mixed in a three-necked flask, a condenser and a thermometer were installed, and a magnetic stirrer was turned on. Glacial acetic acid was added to the three-necked flask to adjust the pH of the system to 5. The reaction was then carried out at 80°C for 4 hours. After the reaction was completed, the nano-silica was filtered out and washed with anhydrous ethanol and deionized water in sequence and then dried to obtain chloropropylated nano-silica.

[0045] S2. By mass, 12 parts of chloropropylated nano silica, 7.2 parts of 4-methylfurano[3,4-b]pyridine-5,7-dione, and 100 parts of acetonitrile were mixed in a three-necked flask, fitted with a condenser and a thermometer, and the magnetic stirring was turned on. The mixture was reacted at 82°C for 8 hours. After the reaction was completed, the nano silica was filtered out and washed with anhydrous ethanol and deionized water in sequence, and then dried to obtain modified nano silica.

[0046] S3. By mass, 83 parts of terephthalic acid, 42 parts of ethylene glycol, 0.025 parts of antimony glycolate, and 0.125 parts of triethyl phosphate were added to a stainless steel reactor under nitrogen protection and polymerized at 240°C for 4 hours to obtain PET oligomers. Then, 12 parts of modified nano-silica were added to the stainless steel reactor, and the pressure inside the stainless steel reactor was reduced to 100 Pa. Polycondensation was completed at 290°C for 4 hours. After the reaction was completed, the product was cooled to room temperature, granulated, and dried to obtain modified PET masterbatch.

[0047] S4. By mass, 100 parts of modified PET masterbatch and 0.2 parts of antioxidant 1010 are mixed and added to a twin-screw extruder. After melt extrusion at a temperature of 290°C, the mixture is blow-molded to obtain the PET packaging material.

[0048] Comparative Example 1

[0049] A PET packaging material is made by the following steps:

[0050] S1. By mass, 83 parts of terephthalic acid, 42 parts of ethylene glycol, 0.025 parts of antimony glycolate, and 0.125 parts of triethyl phosphate were added to a stainless steel reactor under nitrogen protection and polymerized at 240°C for 4 hours to obtain PET oligomer. Then, 12 parts of untreated nano-silica with a particle size of 50-150 nm were added to the stainless steel reactor. The pressure inside the stainless steel reactor was then reduced to 100 Pa, and the reaction was carried out at 290°C for 4 hours to complete the polycondensation. After the reaction was completed, the product was cooled to room temperature, granulated, and dried to obtain PET masterbatch.

[0051] S2. By mass, 100 parts of PET masterbatch and 0.2 parts of antioxidant 1010 are mixed and added to a twin-screw extruder. After melt extrusion at a temperature of 290°C, the mixture is blow-molded to obtain the PET packaging material.

[0052] Experimental Example

[0053] Tensile properties, antibacterial properties, and surface resistivity were tested in Examples 1-3 and Comparative Example 1, respectively. Tensile properties were tested according to GB / T 1040.2-2006 "Determination of Tensile Properties of Plastics". Antibacterial properties were tested according to GB / T 31402-2015 "Test Method for Antibacterial Properties of Plastic Surfaces" to measure the inhibition rate against Escherichia coli and Staphylococcus aureus. Comparative Example 1 served as the control group. Surface resistivity was tested according to GB / T 1410-2006 "Test Method for Volume Resistivity and Surface Resistivity of Solid Insulating Materials". Lower surface resistivity indicates better antistatic ability. The test results are shown in Table 1.

[0054] Table 1

[0055]

[0056]

[0057] As can be seen from Table 1, the PET packaging material of the present invention in Examples 1 to 3 has good antibacterial properties and better tensile strength and surface resistance than Comparative Example 1, indicating that the modified nano silica of the present invention can effectively improve the tensile strength, antibacterial properties and antistatic properties of the material.

[0058] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are merely for the purpose of helping those skilled in the art to understand the method and core ideas of the present invention, including the best mode, and also to enable those skilled in the art to practice the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention. The scope of protection of this patent is defined by the claims and may include other embodiments that those skilled in the art can conceive of. If these other embodiments have structural elements similar to the wording of the claims, or if they include equivalent structural elements that are not substantially different from the wording of the claims, then these other embodiments should also be included within the scope of the claims.

Claims

1. A PET packaging material, characterized in that, It is prepared by the following steps: Preparation of modified nano-silica: Silane coupling agent KH-431 was grafted onto the surface of nano-silica to obtain chloropropylated nano-silica, and then 4-methylfurano[3,4-b]pyridine-5,7-dione was grafted onto the surface of chloropropylated nano-silica via a quaternary ammonium salt reaction to obtain modified nano-silica. Preparation of PET packaging materials: Terephthalic acid, ethylene glycol, catalyst and heat stabilizer are polymerized under nitrogen protection to obtain PET oligomers. Then, nano-silica is added to the PET oligomers. After polycondensation, cooling, pelletizing and drying, modified PET masterbatch is obtained. The modified PET masterbatch and antioxidant are mixed and then melt extruded and blow molded to obtain PET packaging materials. The mass ratio of silane coupling agent KH-431 to nano-silica is 8–12:10–12; The mass ratio of chloropropylated nano-silica to 4-methylfurano[3,4-b]pyridine-5,7-dione is 12–15: 7.2～9.4； The mass ratio of terephthalic acid, ethylene glycol, catalyst, heat stabilizer, and modified nano-silica is 83–99: 42–66: 0.025–0.08: 0.125–0.625: 12–16.

2. The PET packaging material according to claim 1, characterized in that, The particle size of the nano-silica is 50–150 nm.

3. The PET packaging material according to claim 1, characterized in that, The catalyst is one of antimony glycolate or antimony trioxide.

4. A PET packaging material according to claim 1, characterized in that, The heat stabilizer is one of triethyl phosphate or triphenyl phosphate.

5. A PET packaging material according to claim 1, characterized in that, The antioxidant is one of antioxidant 1010 and antioxidant 168.

6. A PET packaging material according to claim 1, characterized in that, The mass ratio of modified PET masterbatch to antioxidant is 100-120:0.2-0.

5.

7. A PET packaging material according to claim 1, characterized in that, The polymerization conditions are a reaction at 220–240℃ for 4–5 hours, the polycondensation conditions are a reaction at 270–290℃ for 4–6 hours, and the melt extrusion temperature is 270–290℃.

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