Preparation method and application of high-barrier PET material
By using composite barrier agents and optimizing process conditions to prepare high-barrier PET materials, the problems of insufficient barrier properties of PET materials and poor bonding of barrier agents were solved, achieving efficient barrier properties and mechanical strength.
Patent Information
- Application Number
- CN202510887325.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-27
- Publication Date
- 2025-10-21
AI Technical Summary
The gas barrier properties, transparency and heat resistance of existing PET materials cannot fully meet market demand, and the poor bonding between the barrier agent and the PET matrix leads to reduced performance of the finished product.
A composite barrier agent including modified nano-silica and ethylene-vinyl alcohol copolymer is used. By optimizing the process conditions, a high-barrier PET material is prepared using a twin-screw extruder. Combined with a lubricant, dispersant and antioxidant, a good combination of the barrier agent and the PET matrix is achieved.
It improves the barrier properties of PET materials, reduces the amount of barrier agent added, and achieves the best barrier performance of PET materials, with good mechanical strength and transparency.
Smart Images
Figure BDA0005474159200000081
Abstract
Description
Technical Field
[0001] The present application relates to a preparation method and application of a high-barrier PET material, belonging to the technical field of polymer materials. Background Art
[0002] High-barrier PET (polyethylene terephthalate) material has good barrier and mechanical properties, low cost, and high cost-effectiveness. It is widely used in food packaging, pharmaceutical storage and other fields, effectively increasing shelf life and improving economic benefits.
[0003] Existing methods for improving the barrier properties of PET primarily include surface coating, multi-layer lamination, blending, or copolymerization. While blending is simple and suitable, the gas barrier properties, transparency, and heat resistance of PET materials produced under current process conditions cannot fully meet market demand, and production processes still need to be improved.
[0004] Meanwhile, in the prior art, a barrier agent is usually added to improve the barrier properties of PET materials. However, when the barrier agent is poorly bonded to the PET matrix, the barrier properties of the finished product may be reduced. Summary of the Invention
[0005] The purpose of the present invention is to provide a preparation method and application of a high-barrier PET material, which can achieve the best barrier performance of the high-barrier PET material by improving the bonding performance between the barrier agent and the PET matrix and optimizing the process conditions.
[0006] According to one aspect of the present application, a method for preparing a high-barrier PET material is provided, comprising the following steps: S1, uniformly mixing 90-95 parts by weight of PET resin, 0.05-5 parts by weight of a composite barrier agent, 0.1-0.5 parts by weight of a lubricant, 0.5-5 parts by weight of a dispersant, and 1-5 parts by weight of an antioxidant, surface crystallizing the mixture, and drying the mixture to obtain a pretreated raw material; S2, adding the pretreated raw material to a twin-screw extruder for melt extrusion and granulation to obtain the high-barrier PET material; the composite barrier agent comprises modified nano-silica and ethylene-vinyl alcohol copolymer.
[0007] Optionally, the lubricant is selected from at least one of oleamide, erucamide, calcium stearate, and silicone.
[0008] Optionally, the dispersant is selected from polyethylene wax, polypropylene wax, nano SO4 2- / At least one of ZrO2 powder.
[0009] Optionally, the antioxidant is selected from at least one of hindered phenol antioxidants, thioester antioxidants, and phosphite antioxidants.
[0010] Optionally, the preparation of the composite barrier includes the following steps: adding nano-silica to a mixed solution of ethanol and water, stirring, dripping a silane coupling agent, adjusting the pH value, heating, drying, and heat treating to obtain modified nano-silica; dispersing the modified nano-silica in an ethylene-vinyl alcohol copolymer matrix to obtain the composite barrier.
[0011] Optionally, the particle size of the nano-silicon dioxide is 10 to 50 nm.
[0012] Optionally, the particle size of the nano-silica is independently selected from any value among 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, or a range between any two of the above points.
[0013] Optionally, the volume concentration of ethanol in the mixed solution is 45% to 75%.
[0014] Optionally, the mass concentration of nano-silicon dioxide is 0.5-10 wt%.
[0015] Optionally, the silane coupling agent is selected from at least one of KH-570, KH-550, A-174, and A-1100.
[0016] Optionally, the mass concentration of the silane coupling agent is 0.5-10 wt %.
[0017] Optionally, the mass concentration of the silane coupling agent is independently selected from any value among 0.5wt%, 0.75wt%, 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt% or the range value between any two of the above points.
[0018] Optionally, the mass concentration of the modified nano-silica is 5 to 30 wt%.
[0019] Optionally, the mass concentration of the modified silica is independently selected from any value of 5wt%, 7.5wt%, 10wt%, 12wt%, 15wt%, 20wt%, 22wt%, 25wt%, 30wt% or a range between any two of the above points.
[0020] Optionally, the stirring is mechanical stirring and / or ultrasonic stirring.
[0021] Optionally, the rotation speed of the mechanical stirring is 100 to 400 rpm.
[0022] Optionally, the frequency of the ultrasonic stirring is 30 to 50 kHz.
[0023] Optionally, the pH value is 4-6.
[0024] Optionally, the heating temperature is 40-70°C.
[0025] Optionally, the heating temperature is independently selected from any value among 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C or a range between any two of the above points.
[0026] Optionally, the heating time is 0.5 to 3 hours.
[0027] Optionally, the heating time is independently selected from any value among 0.5h, 1h, 1.5h, 2h, 2.5h, 3h or a range value between any two of the above points.
[0028] Optionally, the drying temperature is 70-90°C.
[0029] Optionally, the drying temperature is independently selected from any value among 70°C, 75°C, 80°C, 85°C, 90°C or a range between any two of the above points.
[0030] Optionally, the drying time is 2 to 24 hours.
[0031] Optionally, the drying time is independently selected from any value among 2h, 5h, 10h, 15h, 20h, 24h or a range value between any two of the above points.
[0032] Optionally, the heat treatment temperature is 80-200°C.
[0033] Optionally, the temperature of the heat treatment is independently selected from any value among 80°C, 100°C, 150°C, 200°C, or a range between any two of the above points.
[0034] Optionally, the heat treatment time is 0.5 to 2 hours.
[0035] Optionally, the heat treatment time is independently selected from any value among 0.5h, 1h, 1.5h, 2h or a range value between any two of the above points.
[0036] Optionally, the surface crystallization temperature is 120-150°C.
[0037] Optionally, the surface crystallization temperature is independently selected from any value among 120°C, 130°C, 140°C, 150°C, or a range between any two of the above points.
[0038] Optionally, the drying temperature is 160-180°C.
[0039] Optionally, the temperature of the drying treatment is independently selected from any value among 160°C, 165°C, 170°C, 175°C, 180°C, or a range between any two of the above points.
[0040] Optionally, the drying process takes 4 to 8 hours.
[0041] Optionally, the drying time is independently selected from any value among 4h, 5h, 6h, 7h, 8h or a range between any two of the above points.
[0042] Optionally, the temperature of the melt extrusion is 255-280°C.
[0043] Optionally, the melt extrusion temperature is independently selected from any value among 255°C, 260°C, 265°C, 270°C, 275°C, 280°C, or a range between any two of the above points.
[0044] Optionally, the screw aspect ratio of the twin-screw extruder is 25 to 30:1, the main engine speed is 250 to 350 r / min, and the vacuum degree is -0.1 to -0.05 MPa.
[0045] Optionally, the screw aspect ratio of the twin-screw extruder is independently selected from any ratio among 25:1, 26:1, 27:1, 28:1, 29:1, 30:1 or a range between any two of the above ratios.
[0046] Optionally, the main engine speed of the twin-screw extruder is independently selected from any value among 250r / min, 275r / min, 300r / min, 325r / min, 350r / min or a range between any two of the above points.
[0047] Optionally, the vacuum degree of the twin-screw extruder is independently selected from any value among -0.1 MPa, -0.09 MPa, -0.08 MPa, -0.07 MPa, -0.06 MPa, -0.05 MPa, or a range value between any two of the above points.
[0048] According to another aspect of the present application, an application of the high-barrier PET material obtained by the above-mentioned preparation method is provided, comprising the following steps: adding the pre-dried high-barrier PET material into an injection molding machine, injection molding, and obtaining a high-barrier PET finished product.
[0049] Optionally, the pre-drying temperature is 160-180°C.
[0050] Optionally, the pre-drying temperature is independently selected from any value among 160°C, 165°C, 170°C, 175°C, 180°C or a range between any two of the above points.
[0051] Optionally, the pre-drying time is 4 to 6 hours.
[0052] Optionally, the pre-drying time is independently selected from any value among 4h, 4.5h, 5h, 5.5h, 6h or a range between any two of the above points.
[0053] Optionally, the water content of the pre-dried high-barrier PET material is less than 0.03%.
[0054] Optionally, the barrel temperature of the injection molding machine is 200-300°C.
[0055] Optionally, the barrel temperature of the injection molding machine is independently selected from any value among 200°C, 220°C, 240°C, 260°C, 280°C, 300°C or a range between any two of the above points.
[0056] Optionally, the injection molding injection pressure is 60-100 bar.
[0057] Optionally, the injection molding injection pressure is independently selected from any value among 60 bar, 70 bar, 80 bar, 90 bar, 100 bar, or a range between any two of the above points.
[0058] Optionally, the mold temperature of the injection molding is 80-100°C.
[0059] Optionally, the mold temperature for the injection molding is independently selected from any value among 80°C, 85°C, 90°C, 95°C, 100°C, or a range between any two of the above points.
[0060] The beneficial effects of this application include:
[0061] 1) The preparation method of the high-barrier PET material provided in this application uses a composite barrier agent with high barrier efficiency, which not only can reduce the amount added to the functional PET material, but also the ethylene-vinyl alcohol copolymer (EVOH) in the composite barrier agent has good compatibility with the PET matrix, and the barrier agent can achieve good bonding with the matrix.
[0062] 2) The preparation method of the high-barrier PET material provided in this application can achieve the best performance of the barrier properties of the high-barrier PET material by optimizing the design of process parameters and combining the use of a composite barrier agent. DETAILED DESCRIPTION
[0063] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.
[0064] Unless otherwise specified, the raw materials and reagents in the examples of this application were purchased through commercial channels.
[0065] The analysis method in the examples of this application is as follows:
[0066] Tensile strength: tested according to GB / T1040-2006 standard, where the stretching rate is 50 mm / min and the stretching temperature is 25°C.
[0067] Bending strength: tested according to GB / T9341-2008 standard, where the specific test conditions are: sample size 80×10×4mm, pressing speed 2mm / min.
[0068] Oxygen barrier performance analysis: Use Y110 oxygen transmission rate tester to test the oxygen barrier performance of the sample in accordance with GB / T 1038-2000, and record the oxygen transmission rate of the sample.
[0069] Water barrier performance analysis: Use TC-03 water vapor transmission meter to test the water barrier performance of the sample in accordance with GB / T 1037-2021, and record the water vapor transmission rate of the sample.
[0070] Example 1
[0071] (1) Preparation of composite barrier agent: 2 wt% nano-silica (particle size 20 nm) was added to a mixed solution of ethanol and water (ethanol: water = 1:1), and stirred uniformly by mechanical stirring and ultrasonic stirring, wherein the mechanical stirring speed was 300 rpm and the ultrasonic stirring frequency was 40 kHz, 2 wt% KH-570 was added dropwise, the pH value was adjusted to 5.5, the mixture was reacted at 70 ° C for 2 h, dried at 80 ° C for 6 h, and heat treated at 120 ° C for 1 h to obtain modified nano-silica. The modified nano-silica was dispersed in ethylene-vinyl alcohol copolymer, and the mass ratio of modified nano-silica to ethylene-vinyl alcohol copolymer was 1:5. The mixture was added to a twin-screw extruder, and the mixture was blended, melted, extruded, and pelletized by the twin-screw extruder to obtain a composite barrier agent.
[0072] (2) Preparation of high barrier PET material: 93 parts by weight of PET resin, 0.25 parts by weight of composite barrier agent, 0.5 parts by weight of oleic acid amide, 1.25 parts by weight of polyethylene wax and 5 parts by weight of hindered phenol antioxidant were mixed evenly, surface crystallized at 125°C, and dried at 160°C for 6 hours to obtain pretreated raw materials; the pretreated raw materials were added to a twin-screw extruder for melt extrusion and granulation to obtain the high barrier PET material, the melt extrusion temperature was 260°C, the screw aspect ratio of the twin-screw extruder was 30:1, the main engine speed was 350r / min, and the vacuum degree was -0.06MPa.
[0073] (3) Preparation of high-barrier PET finished product: The high-barrier PET material pre-dried at 160°C for 5 hours was added to an injection molding machine and injection molded. The barrel temperature of the injection molding machine was 220°C, the injection pressure was 60 bar, and the mold temperature was 80°C to obtain a high-barrier PET sample A.
[0074] Example 2
[0075] The difference between Example 2 and Example 1 is that the particle size of the nano-silica is 50 nm. The other operating steps are the same, and a high-barrier PET sample B is prepared.
[0076] Example 3
[0077] The difference between Example 3 and Example 1 is that the amount of nano-silicon dioxide used is 5 wt %. The other operating steps are the same, and a high-barrier PET sample C is prepared.
[0078] Example 4
[0079] The difference between Example 4 and Example 1 is that the amount of KH-570 used is 5 wt %. The other operating steps are the same, and a high-barrier PET sample D is prepared.
[0080] Example 5
[0081] The difference between Example 5 and Example 1 is that the surface crystallization temperature is 150° C., and the other operating steps are the same, and a high-barrier PET sample E is prepared.
[0082] Example 6
[0083] The difference between Example 6 and Example 1 is that the melt extrusion temperature is 280° C., and the other operating steps are the same, and a high-barrier PET sample F is obtained.
[0084] Example 7
[0085] The difference between Example 7 and Example 1 is that the barrel temperature of the injection molding machine is 250° C., and the other operating steps are the same to prepare a high-barrier PET sample G.
[0086] Example 8
[0087] The difference between Example 8 and Example 1 is that oleamide is replaced by erucamide, and the other operating steps are the same to prepare a high-barrier PET sample H.
[0088] Comparative Example 1
[0089] The difference between Comparative Example 1 and Example 1 is that nano-silica is used instead of the composite barrier agent, and the remaining operating steps are the same to prepare a high-barrier PET sample I.
[0090] Comparative Example 2
[0091] The difference between Comparative Example 2 and Example 1 is that ethylene-vinyl alcohol copolymer is used instead of the composite barrier agent, and the remaining operating steps are the same to prepare a high-barrier PET sample J.
[0092] Comparative Example 3
[0093] The difference between Comparative Example 3 and Example 1 is that the melt extrusion temperature is 350° C., and the remaining operating steps are the same, to obtain a high-barrier PET sample K.
[0094] Comparative Example 4
[0095] The difference between Comparative Example 5 and Example 1 is that the barrel temperature of the injection molding machine is 400° C., and the remaining operating steps are the same to prepare a high-barrier PET sample L.
[0096] Test Example 1
[0097] The high barrier PET samples A to L prepared in Examples 1 to 8 and Comparative Examples 1 to 4 were subjected to performance tests. The test results of tensile strength, flexural strength, oxygen barrier performance, and water barrier performance of the high barrier PET samples are shown in Table 1.
[0098] Table 1 Performance test results
[0099]
[0100] As shown in Table 1, the high-barrier PET materials prepared according to the preparation methods described herein in Examples 1-8 exhibit excellent barrier properties. The composite barrier agent exhibits high barrier efficiency and excellent compatibility with the PET matrix. Optimizing the process parameters also achieves optimal barrier performance for the high-barrier PET material.
[0101] The barrier effects of nano-silica and ethylene-vinyl alcohol copolymer alone in Comparative Examples 1 and 2 were significantly worse than those of the samples in Examples 1 to 8. In Comparative Examples 3 and 4, excessively high barrel temperatures during melt extrusion and injection molding resulted in yellowing of the samples and decreased mechanical strength.
[0102] Unless otherwise specified, all numbers appearing in the specification and claims of this application, such as active components, temperature and time, conversion rate, etc., should not be understood as absolutely precise values. Due to the standard deviation of the measurement technology, the measured values inevitably have certain experimental errors.
[0103] The above descriptions are merely a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application discloses the preferred embodiments as above, they are not intended to limit the present application. Any technical personnel familiar with the present profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.
Claims
1. A method for preparing a high barrier PET material, characterized in that: The following steps are involved: S1. Evenly mix 90-95 parts by weight of PET resin, 0.05-5 parts by weight of composite barrier agent, 0.1-0.5 parts by weight of lubricant, 0.5-5 parts by weight of dispersant and 1-5 parts by weight of antioxidant, perform surface crystallization and dry treatment to obtain pretreated raw material; S2, adding the pretreated raw materials into a twin-screw extruder for melt extrusion and granulation to obtain the high barrier PET material; The composite barrier comprises modified nano silicon dioxide and ethylene-vinyl alcohol copolymer.
2. The preparation method according to claim 1, characterized in that The lubricant is selected from at least one of oleamide, erucamide, calcium stearate, and silicone; Preferably, the dispersant is selected from polyethylene wax, polypropylene wax, nano SO4 2- / at least one of ZrO2 powder; Preferably, the antioxidant is selected from at least one of hindered phenol antioxidants, thioester antioxidants, and phosphite antioxidants.
3. The preparation method according to claim 1, characterized in that The preparation of the composite barrier comprises the following steps: adding nano-silica to a mixed solution of ethanol and water, stirring, dripping a silane coupling agent, adjusting the pH value, heating, drying, and heat treating to obtain modified nano-silica; and dispersing the modified nano-silica in an ethylene-vinyl alcohol copolymer matrix to obtain the composite barrier.
4. The preparation method according to claim 3, characterized in that The particle size of the nano-silicon dioxide is 10 to 50 nm; Preferably, the volume concentration of ethanol in the mixed solution is 45% to 75%; Preferably, the mass concentration of nano-silicon dioxide is 0.5 to 10 wt%; Preferably, the silane coupling agent is selected from at least one of KH-570, KH-550, A-174, and A-1100; Preferably, the mass concentration of the silane coupling agent is 0.5 to 10 wt%; Preferably, the mass concentration of the modified nano-silica is 5 to 30 wt%.
5. The preparation method according to claim 3, characterized in that The stirring is mechanical stirring and / or ultrasonic stirring; Preferably, the rotation speed of the mechanical stirring is 100 to 400 rpm; Preferably, the frequency of the ultrasonic stirring is 30 to 50 kHz.
6. The preparation method according to claim 3, characterized in that The pH value is 4 to 6; Preferably, the heating temperature is 40-70°C; The heating time is 0.5 to 3 hours; Preferably, the drying temperature is 70-90°C; The drying time is 2 to 24 hours; Preferably, the temperature of the heat treatment is 80-200°C; The heat treatment time is 0.5 to 2 hours.
7. The preparation method according to claim 1, characterized in that In step S1, The surface crystallization temperature is 120-150°C; Preferably, the drying temperature is 160-180°C; The drying time is 4 to 8 hours.
8. The preparation method according to claim 1, characterized in that In step S2, The temperature of the melt extrusion is 255-280°C; Preferably, the screw aspect ratio of the twin-screw extruder is 25 to 30:1, the main engine speed is 250 to 350 r / min, and the vacuum degree is -0.1 to -0.05 MPa.
9. Use of a high barrier PET material prepared by the preparation method according to claims 1 to 8, characterized in that: The following steps are involved: The pre-dried high-barrier PET material is added to an injection molding machine and injection molded to obtain a high-barrier PET finished product.
10. The use according to claim 9, characterized in that The pre-drying temperature is 160-180°C; The pre-drying time is 4 to 6 hours; Preferably, the barrel temperature of the injection molding machine is 200-300°C; Preferably, the injection molding injection pressure is 60 to 100 bar; The mold temperature of the injection molding is 80-100°C.