Preparation method and application of blocking agent
By preparing a core-shell structured nano-silica-polyacrylic acid barrier agent, the problem of the barrier agent affecting the light transmittance of PET materials was solved, achieving high light transmittance barrier performance, which is suitable for functional PET materials.
Patent Information
- Application Number
- CN202510846156.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-23
- Publication Date
- 2025-11-14
AI Technical Summary
While existing barrier agents improve the barrier properties of PET materials, they also reduce light transmittance, affecting subsequent processing and use.
A core-shell barrier agent was prepared by polymerizing nano-silica with acrylic acid solution. By modifying the compatibility of silica with PET material and the polyacrylic acid shell, light scattering was reduced and light transmittance was improved.
The prepared barrier agent has a light transmittance of over 95% in functional PET materials, and the preparation method is simple and easy to operate.
Smart Images
Figure BDA0005463891410000061
Abstract
Description
Technical Field
[0001] This application relates to a method for preparing and applying a barrier agent, belonging to the field of barrier agent technology. Background Technology
[0002] PET (polyethylene terephthalate) is a common packaging material widely used in food, pharmaceuticals, and cosmetics. With the continuous development of modern packaging technology, the functional requirements of packaging materials are increasing, leading to a growing demand for functional PET materials.
[0003] Existing technologies often employ the addition of barrier agents to improve the barrier properties of functional PET materials, thereby reducing the permeation of gases (such as oxygen and carbon dioxide) and water vapor. However, the use of barrier agents can also lead to a decrease in the light transmittance of functional PET materials, affecting subsequent processing and use.
[0004] Therefore, the development of novel barrier agents that do not affect the light transmittance of functional PET materials remains an urgent problem to be solved in the industry. Summary of the Invention
[0005] To address the shortcomings of existing technologies, this application provides a method for preparing a barrier agent and its application. The barrier agent prepared by the method described in this application can achieve a light transmittance of over 95% when applied to functional PET materials, and the preparation method is simple and easy to operate.
[0006] According to one aspect of this application, a method for preparing a barrier agent is provided, comprising the following steps:
[0007] S1: Add nano-silica to a mixed solution of ethanol and water, stir, and obtain solution A;
[0008] S2: Add silane coupling agent dropwise to solution A, adjust the pH value, heat, dry, and heat treat to obtain modified silica;
[0009] S3: The modified silica is mixed with an acrylic acid solution, an initiator is added, and a polymerization reaction is carried out to obtain the barrier agent.
[0010] Optionally, the barrier agent is a core-shell structured microsphere.
[0011] Optionally, the particle size of the barrier agent is 80-150 nm.
[0012] Optionally, the particle size of the barrier agent is independently selected from any value of 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm or a range between any two of the above.
[0013] Optionally, the particle size of the nano-silica is 10-50 nm.
[0014] Optionally, the particle size of the nano-silica is independently selected from any value among 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, and 50nm, or a range between any two of the above.
[0015] Optionally, the volume concentration of ethanol in the mixed solution is 45% to 75%.
[0016] Optionally, the mass concentration of nano-silica in solution A is 0.5–10 wt%.
[0017] Optionally, solution A can be prepared by a combination of mechanical stirring and ultrasonication.
[0018] Optionally, the frequency of the ultrasonic wave is 30 to 50 kHz.
[0019] Optionally, the silane coupling agent is selected from at least one of KH-570, KH-550, A-174, and A-1100.
[0020] Optionally, the mass concentration of the silane coupling agent is 0.5 to 10 wt%.
[0021] 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%, and 10wt%, or a range between any two of the above points.
[0022] Optionally, the mass concentration of the modified silica is 5–30 wt%.
[0023] 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.
[0024] Optionally, the solvent in the acrylic acid solution is at least one of ethanol and water.
[0025] Optionally, the mass concentration of acrylic acid in the acrylic acid solution is 20–40 wt%.
[0026] Optionally, the mass concentration of acrylic acid in the acrylic acid solution is independently selected from any value among 20wt%, 25wt%, 30wt%, 35wt%, and 40wt%, or a range between any two of the above points.
[0027] Optionally, the initiator is selected from at least one of ammonium persulfate and potassium persulfate.
[0028] Optionally, the initiator has a mass concentration of 0.05–2 wt%.
[0029] Optionally, the mass concentration of the initiator is independently selected from any value among 0.05wt%, 0.1wt%, 0.15wt%, 0.25wt%, 0.5wt%, 0.75wt%, 1wt%, 1.25wt%, 1.5wt%, 1.75wt%, and 2wt%, or a range between any two of the above points.
[0030] Optionally, the stirring speed is 100 to 400 rpm.
[0031] Optionally, the pH value is 4 to 6.
[0032] Optionally, the heating temperature is 40–70°C.
[0033] Optionally, the heating temperature is independently selected from any value among 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, and 70°C, or a range between any two of the above points.
[0034] Optionally, the heating time is 0.5 to 3 hours.
[0035] Optionally, the drying temperature is 70–90°C.
[0036] Optionally, the drying time is 2 to 24 hours.
[0037] Optionally, the temperature of the heat treatment is 80–200°C.
[0038] Optionally, the temperature of the heat treatment is independently selected from any value among 80°C, 100°C, 120°C, 140°C, 160°C, 180°C, and 200°C, or a range between any two of the above points.
[0039] Optionally, the heat treatment time is 0.5 to 2 hours.
[0040] Optionally, the polymerization reaction is carried out at a temperature of 25–75°C.
[0041] Optionally, the temperature of the polymerization reaction is independently selected from any value of 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, or a range between any two of the above points.
[0042] Optionally, the polymerization reaction takes 0.5 to 4 hours.
[0043] Optionally, the polymerization reaction time is independently selected from any value among 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, and 4h, or a range between any two of the above points.
[0044] According to another aspect of this application, the application of the barrier agent prepared by the above preparation method in functional PET is provided.
[0045] Optionally, the process includes the following steps: mixing 98-99.5 parts by weight of PET resin and 0.5-2 parts by weight of barrier agent by vibration, extruding the mixture through a twin-screw extruder for melt blending, cooling with a cooling roller, and then winding it into a film.
[0046] Optionally, flame retardants, light stabilizers, and other additives can be added according to actual needs to prepare different functional PET materials.
[0047] Optionally, the raw materials are shaken and mixed during the above application process to reduce the aggregation of nanoparticles.
[0048] Optionally, the extrusion temperature is 260–280°C.
[0049] Optionally, the cooling temperature is 80–100°C.
[0050] Optionally, the resulting functional PET film has a light transmittance of over 95%.
[0051] The beneficial effects that this application can produce include:
[0052] 1) The barrier agent prepared by the method described in this application is a core-shell structured nanosphere with modified silica as the core and polyacrylic acid as the shell. The barrier agent prepared by the method described in this application has good dispersibility and high compatibility with PET materials. At the same time, the polyacrylic acid shell can reduce light scattering, thereby improving light transmittance.
[0053] 2) The method for preparing the barrier agent provided in this application has the advantages of being simple and easy to operate. The prepared barrier agent does not affect the light transmittance of functional PET materials, and the light transmittance can reach more than 95%. Detailed Implementation
[0054] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.
[0055] Unless otherwise specified, the raw materials and reagents used in the embodiments of this application were all purchased commercially.
[0056] The analysis method in the embodiments of this application is as follows:
[0057] Transmittance analysis: The transmittance of the samples was tested using a BYK transmission haze meter from Germany.
[0058] Oxygen barrier performance analysis: The oxygen barrier performance of the samples was tested using a Y110 oxygen permeability tester in accordance with GB / T 1038-2000, and the oxygen permeability of the samples was recorded.
[0059] Water barrier performance analysis: The water barrier performance of the samples was tested using a TC-03 water vapor transmission rate tester according to GB / T 1037-2021, and the water vapor transmission rate of the samples was recorded.
[0060] Example 1
[0061] 2 wt% of nano-silica (particle size 20 nm) was added to a mixed solution of ethanol and water (ethanol:water = 1:1), and stirred until homogeneous using a combination of mechanical stirring and ultrasonication at 300 rpm and 40 kHz, yielding solution A. 2 wt% of KH-570 was added dropwise to solution A, the pH was adjusted to 5.5, the reaction was carried out at 70℃ for 2 h, dried at 80℃ for 6 h, and heat-treated at 120℃ for 1 h to obtain modified nano-silica. 5 wt% of the modified nano-silica was mixed with an acrylic acid solution, and 0.1 wt% ammonium persulfate solution was added dropwise, reacting at 40℃ for 2 h. After the reaction was complete, the mixture was washed and dried to obtain barrier agent A.
[0062] Example 2
[0063] The difference between Example 2 and Example 1 is that the particle size of the nano-silica is 50nm, while the other operation steps are the same, and barrier agent B is obtained.
[0064] Example 3
[0065] The difference between Example 3 and Example 1 is that the amount of nano-silica used is 5wt%, while the other operation steps are the same, and barrier agent C is obtained.
[0066] Example 4
[0067] The difference between Example 4 and Example 1 is that the silane coupling agent used is A-174, while the other operation steps are the same, and the barrier agent D is obtained.
[0068] Example 5
[0069] The difference between Example 5 and Example 1 is that the amount of KH-570 used is 5wt%, while the other operation steps are the same, and the barrier agent E is obtained.
[0070] Example 6
[0071] The difference between Example 6 and Example 1 is that the pH value is adjusted to 4, while the other operation steps are the same, and the barrier agent F is obtained.
[0072] Example 7
[0073] The difference between Example 7 and Example 1 is that the amount of ammonium persulfate solution used is 1 wt%, while the other operation steps are the same, and the barrier agent G is obtained.
[0074] Comparative Example 1
[0075] The difference between Comparative Example 1 and Example 1 is that the amount of KH-570 used is 20wt%, while the other operation steps are the same, and the barrier agent H is obtained.
[0076] Comparative Example 2
[0077] The difference between Comparative Example 2 and Example 1 is that the reaction temperature after adding the silane coupling agent is 100°C, while the other operation steps are the same, and barrier agent I is obtained.
[0078] Test Example 1
[0079] The raw materials, 1.5 parts of the barrier agent and 98.5 parts of PET resin prepared in Examples 1-7 and Comparative Examples 1-2, were mixed by vibration. The mixture was then melt-blended and extruded through a twin-screw extruder, cooled by a cooling roller, and wound into a film to obtain samples A-I. Performance tests were performed on samples A-I, and the test results of light transmittance, oxygen barrier properties, and water barrier properties are shown in Table 1.
[0080] Table 1 Performance Test Results
[0081]
[0082] As shown in Table 1, the barrier agents in Examples 1-7 exhibit excellent barrier properties when applied to PET materials, without affecting the light transmittance of functional PET materials, with a transmittance exceeding 95%. The barrier agent prepared by the method described in this application has good dispersibility and high compatibility with PET materials. Furthermore, the polyacrylic acid shell reduces light scattering, thereby improving light transmittance.
[0083] Unless otherwise specified, all figures appearing in this application specification and claims, such as temperature and time, light transmittance, etc., should not be construed as absolutely precise values. Due to the standard deviation of measurement techniques, the measured values inevitably contain a certain degree of experimental error.
[0084] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.
Claims
1. A method for preparing a barrier agent, characterized in that, Includes the following steps: S1: Add nano-silica to a mixed solution of ethanol and water, stir, and obtain solution A; S2: Add silane coupling agent dropwise to solution A, adjust the pH value, heat, dry, and heat treat to obtain modified nano-silica; S3: The modified nano-silica is mixed with an acrylic acid solution, an initiator is added, and a polymerization reaction is carried out to obtain the barrier agent.
2. The preparation method according to claim 1, characterized in that, The barrier agent is a core-shell structured microsphere; Preferably, the particle size of the barrier agent is 80–150 nm.
3. The preparation method according to claim 1, characterized in that, In step S1, The particle size of the nano-silica is 10–50 nm; Preferably, the volume concentration of ethanol in the mixed solution is 45% to 75%; Preferably, the mass concentration of nano-silica in solution A is 0.5–10 wt%.
4. The preparation method according to claim 1, characterized in that, In step S2, 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 0.5–10 wt%.
5. The preparation method according to claim 1, characterized in that, In step S3, The modified nano-silica has a mass concentration of 5–30 wt%. Preferably, the solvent in the acrylic acid solution is at least one of ethanol and water; Preferably, the mass concentration of acrylic acid in the acrylic acid solution is 20-40 wt%. Preferably, the initiator is selected from at least one of ammonium persulfate and potassium persulfate; Preferably, the initiator has a mass concentration of 0.05–2 wt%.
6. The preparation method according to claim 1, characterized in that, In step S1, The stirring speed is 100-400 rpm.
7. The preparation method according to claim 1, characterized in that, In step S2, The pH value is 4–6; 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.
8. The preparation method according to claim 1, characterized in that, In step S3, The polymerization reaction is carried out at a temperature of 25–75°C. The polymerization reaction takes 0.5 to 4 hours.
9. The application of a barrier agent prepared by the preparation method according to claims 1 to 8 in functional PET.
10. The application according to claim 9, characterized in that, Includes the following steps: The raw materials of 98-99.5 parts by weight of PET resin and 0.5-2 parts by weight of barrier agent are mixed by vibration. The mixture is then melt-blended and extruded through a twin-screw extruder, cooled by cooling rollers, and wound into a film. Preferably, the extrusion temperature is 260–280°C; Preferably, the cooling temperature is 80–100°C.