High-barrier antibacterial multilayer polymeric membrane and preparation method thereof
By using chemical encapsulation and multi-layer co-extrusion film technology to prepare multi-layer polymer films, the balance problem between antibacterial and barrier properties of traditional packaging films is solved, the sustained and controlled release of antibacterial substances and the improvement of water vapor barrier properties are achieved, and a highly efficient food preservation material is provided.
Patent Information
- Application Number
- CN202510876920.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-27
- Publication Date
- 2025-10-03
AI Technical Summary
Traditional single-layer or simple composite packaging films are difficult to achieve a balance between antibacterial and barrier properties. There are problems such as high migration rate of inorganic antibacterial substances, easy decomposition of organic antibacterial substances when heated, and sudden release of antibacterial substances, which make fresh food easy to spoil.
The chemical encapsulation method is used to prepare loaded antibacterial nanoparticles, which are then combined with the grafting modification method and multi-layer co-extrusion film technology to form a multi-layer polymer film, including a modified polyethylene functional antibacterial sustained-release layer, to improve the antibacterial performance through the synergistic release path of antibacterial substances and water vapor barrier properties.
It achieves the sustained and controlled release of antibacterial substances, enhances the water vapor barrier and food preservation properties, has strong antibacterial ability, and provides a highly efficient antibacterial packaging material.
Smart Images
Figure CN120735446A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of fresh food packaging, and more particularly to a high-barrier and antibacterial multilayer polymer film and a preparation method thereof. Background Art
[0002] Fresh food generally has a high water content and is rich in nutrients, which makes it suitable for the growth and reproduction of microorganisms. It is very easy to cause corruption and spoilage, resulting in color deterioration and loss of nutrients, seriously affecting the shelf life of the product and restricting the product's circulation radius.
[0003] High-barrier antibacterial packaging technology has become one of the effective means to slow down the spoilage of fresh foods such as livestock and poultry meat by inhibiting the activity of microorganisms and blocking the penetration of external oxygen and water vapor. However, although traditional single-layer or simple composite packaging films such as polyethylene, polypropylene or a composite of the two have certain barrier properties, they still face the problems of high migration rate of inorganic antibacterial substances, easy decomposition of organic antibacterial substances when heated, and sudden release of antibacterial substances, making it difficult to achieve a balance between the antibacterial function and barrier performance of the packaging material.
[0004] Therefore, a high-barrier antibacterial multilayer polymer film and a preparation method thereof are proposed to solve the above problems. Summary of the Invention
[0005] In view of the shortcomings of the prior art, the object of the present invention is to provide a high-barrier and antibacterial multilayer polymer film with strong water vapor barrier capability and good antibacterial performance and a preparation method thereof.
[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: a high-barrier antibacterial multilayer polymer film comprises a first modified polyethylene functional antibacterial sustained-release layer, a second modified polyethylene functional antibacterial sustained-release layer, a third modified polyethylene functional antibacterial layer, and other functional layers; wherein, the first modified polyethylene functional antibacterial sustained-release layer, the second modified polyethylene functional antibacterial sustained-release layer, and the third modified polyethylene functional antibacterial layer are all made of antibacterial nanoparticles and modified polyethylene.
[0007] A method for preparing a high-barrier antibacterial multilayer polymer film, according to the above-mentioned high-barrier antibacterial multilayer polymer film, comprises the following steps: S1. A functional antibacterial substance and mesoporous nanoparticles are chemically encapsulated to prepare antibacterial nanoparticles; wherein the functional antibacterial substance is one or more of tannic acid, citric acid, tartaric acid, and fumaric acid; the mass ratio of the functional antibacterial substance to the mesoporous nanoparticles is 1:(0.01-3); and the mesoporous nanoparticles are one or two of mesoporous zinc oxide and mesoporous titanium dioxide.
[0008] By adopting the above-mentioned chemical embedding method to prepare antibacterial nanoparticles loaded with antibacterial substances, the sudden release of the antibacterial substances can be avoided.
[0009] S2, polyethylene and graft modified substances are grafted and modified by a method combining a precision screw extrusion process to prepare a modified polyethylene masterbatch; the polyethylene density is 0.90-0.96 g / cm 3 , melt index is 0.2-1.0g / min; precision screw extrusion granulation temperature control accuracy does not exceed ±1°C; granulation temperature is 160-200°C; screw speed is 180-400rpm; grafted modification substances include one or two of maleic anhydride, acrylic acid, and vinyltrimethoxysilane; the grafting rate of modified polyethylene masterbatch is 0.6-1.5%.
[0010] By using the above-mentioned maleic anhydride, acrylic acid, etc. as grafted modified substances, modified polyethylene masterbatch is prepared to increase the bonding ability between different packaging layers.
[0011] S3. Physically blending the antibacterial nanoparticles and modified polyethylene masterbatch in different proportions to prepare multiple groups of modified polyethylene antibacterial sustained-release masterbatch; wherein the vacuum drying temperature of the antibacterial nanoparticles and the modified polyethylene masterbatch is 50-80°C, and the mass ratio is 1:(10-100); the twin-screw granulation temperature is 160-200°C; the screw speed is 250-450rpm; and the dispersant is one or two of polyethylene wax, zinc stearate, and calcium stearate.
[0012] S4. The modified polyethylene antibacterial slow-release masterbatch and other functional raw materials are subjected to multi-layer co-extrusion film-making technology to form a high-barrier antibacterial multilayer polymer film having a first modified polyethylene functional antibacterial slow-release layer, a second modified polyethylene functional antibacterial slow-release layer, a third modified polyethylene functional antibacterial layer, and other functional layers. The high-barrier antibacterial multilayer polymer film has 4-13 layers; the thickness of the first modified polyethylene functional antibacterial slow-release layer, the second modified polyethylene functional antibacterial slow-release layer, and the third modified polyethylene functional antibacterial layer in the high-barrier antibacterial multilayer polymer film are all 10-50 μm.
[0013] By adopting the above three groups of modified polyethylene functional antibacterial layers, the antibacterial substance content and the antibacterial substance release path work together to achieve the sustained and controlled release of antibacterial substances, improve water vapor barrier properties, antibacterial activity and food preservation performance, and have strong antibacterial ability, providing new antibacterial packaging materials for the food processing industry.
[0014] Application of a high-barrier and antibacterial multilayer polymer film: The high-barrier and antibacterial multilayer polymer film can be used for food packaging.
[0015] In summary, this application includes at least one of the following beneficial technical effects: 1. The antibacterial nanoparticles loaded with antibacterial substances are prepared by chemical encapsulation method, which can avoid the sudden release of antibacterial substances.
[0016] 2. Prepare modified polyethylene masterbatch by using maleic anhydride, acrylic acid, etc. as grafting modification substances to increase the bonding ability between different packaging layers.
[0017] 3. Through three groups of modified polyethylene functional antibacterial layers, the antibacterial substance content and the antibacterial substance release path work together to achieve sustained and controlled release of antibacterial substances, improve water vapor barrier properties, antibacterial activity and food preservation performance, and have strong antibacterial ability, providing new antibacterial packaging materials for the food processing industry. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 Schematic diagram of the structure of the antibacterial nanoparticles in Example 1 of the present invention; Figure 2 Schematic diagram of the structure of the grafted modified polyethylene molecule in Example 1 of the present invention; Figure 3 This is a schematic structural diagram of the high-barrier and antibacterial multilayer polymer film in Example 1 of the present invention; Figure 4 This is a diagram of the migration path of antibacterial substances in the high-barrier antibacterial multilayer polymer film of the present invention. DETAILED DESCRIPTION
[0019] 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 disclosure pertains. In the event of a conflict, the definitions in this specification shall prevail.
[0020] Unless otherwise indicated, all percentages, parts, ratios, etc. are by weight.
[0021] As used herein, the terms "comprises," "includes," "has," "having," "containing," or any other variations thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may also include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.
[0022] When quantity, weight part or other numerical value or parameter is given as range, preferred range or a series of upper preferred value and lower preferred value, it should be understood that it specifically discloses all ranges formed by any pair of numerical values of any larger range limit or preferred value and any smaller range limit or preferred value, and no matter whether scope is disclosed respectively.For example, when describing the scope of "1 to 5", described scope should be understood as including the scope of "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5" etc.Unless otherwise stated, when describing numerical range herein, described range is intended to include range end value and all integers, fractions, decimals etc. within the range.
[0023] The present invention provides a high-barrier and antibacterial multilayer polymer film, which is characterized in that antibacterial nanoparticles loaded with functional antibacterial substances are prepared by a chemical embedding method, modified polyethylene masterbatch is prepared by a grafting modification method, and the antibacterial nanoparticles and the modified polyethylene masterbatch are physically blended to form a modified polyethylene functional antibacterial sustained-release masterbatch; a high-barrier and antibacterial multilayer polymer film is obtained by multi-layer gradient structure design combined with multi-layer co-extrusion film making technology, and its multi-layer structure is composed of a first modified polyethylene functional antibacterial sustained-release layer, a second modified polyethylene functional antibacterial sustained-release layer, a third modified polyethylene functional antibacterial layer, and other functional layers from the inside to the outside.
[0024] Furthermore, the antibacterial nanoparticles are prepared by chemically encapsulating functional antibacterial substances within mesoporous nanoparticles to produce the antibacterial nanoparticles. The pores of the mesoporous nanoparticles can carry more antibacterial substances. Based on pore diffusion theory, the release rate of antibacterial substances embedded in the pores is slower than that of unencapsulated antibacterial substances, facilitating long-term sustained release of the antibacterial substances.
[0025] Among them, the functional antibacterial substance includes one or two of organic phenolic acids such as tannic acid and salicylic acid; the mass ratio of organic phenolic acid to mesoporous nanoparticles is 1: (0.01-3); the mesoporous nanoparticles include one or two of mesoporous zinc oxide and mesoporous titanium dioxide.
[0026] Furthermore, the modified polyethylene masterbatch is prepared using a grafting modification method combined with a precision screw extrusion process to obtain the modified polyethylene masterbatch. Grafting modified polyethylene with organic molecules such as maleic anhydride can increase the bonding strength between polyethylene layers, facilitating the blending and modification of antibacterial nanoparticles. This increases the dispersibility of the nanoparticles in the polyethylene masterbatch, laying the foundation for the preparation of functional antibacterial masterbatches containing modified polyethylene with uniformly dispersed antibacterial substances.
[0027] The polyethylene has a density of 0.90-0.96 g / cm3 and a melt index of 0.2-1.0 g / min; the temperature control accuracy of the precision screw extrusion granulation does not exceed ±1°C; the granulation temperature is 160-200°C; the screw speed is 180-400 rpm; the grafted modification substance includes one or two of maleic anhydride, acrylic acid, and vinyltrimethoxysilane; and the grafting rate of the modified polyethylene masterbatch is 0.6-1.5%.
[0028] Furthermore, the modified polyethylene antibacterial sustained-release masterbatch is prepared by physically blending dried antibacterial nanoparticles with modified polyethylene masterbatch, followed by a precision screw extrusion granulation process to produce the modified polyethylene functional antibacterial sustained-release masterbatch. Active functional groups, such as carboxyl groups, on the surface of the antibacterial nanoparticles react with organic molecules, such as maleic anhydride, grafted onto the surface of the modified polyethylene masterbatch, reducing the dissolution of the antibacterial nanoparticles and achieving long-term controlled release.
[0029] The vacuum drying temperature of the antibacterial nanoparticles and the modified polyethylene masterbatch is 50-80°C, and the mass ratio is 1:(10-100); the twin-screw granulation temperature is 160-200°C; the screw speed is 250-450rpm; and the dispersant is one or two of polyethylene wax, zinc stearate, and calcium stearate.
[0030] Furthermore, the method for preparing the high-barrier, antibacterial multilayer polymer film utilizes a multilayer gradient structure design combined with multilayer co-extrusion film-making technology to produce a multilayer polymer film with high barrier and antibacterial properties. By adjusting the antibacterial substance content and the film structure, the antibacterial substance content gradually increases from the inside out of the multilayer structure, thereby extending the migration distance of the antibacterial substance, reducing the sudden release of the antibacterial substance, and improving the safety of the antibacterial substance application.
[0031] Among them, the multi-layer gradient structure is composed of the first modified polyethylene functional antibacterial sustained-release layer, the second modified polyethylene functional antibacterial sustained-release layer, the third modified polyethylene functional antibacterial layer, and other functional layers from the inside to the outside. The overall number of layers of the polymer film is 4-13 layers; the thickness of the single modified polyethylene functional antibacterial sustained-release layer is 10-50μm; the temperature of the feeding section of the multi-layer co-extrusion film is 90-120℃, the temperature of the compression section is 130-170℃, the temperature of the homogenization section is 180-210℃, and the die head pressure is 8-15Mpa.
[0032] Furthermore, the mass ratio of antibacterial nanoparticles to modified polyethylene in the first modified polyethylene functional antibacterial sustained-release layer is 1:(100-200); the first modified polyethylene functional antibacterial sustained-release layer accounts for 3-10% of the mass of the high-barrier antibacterial multilayer polymer film.
[0033] Furthermore, the mass ratio of antibacterial nanoparticles to modified polyethylene in the second modified polyethylene functional antibacterial sustained-release layer is 1:(66-100); the second modified polyethylene functional antibacterial sustained-release layer accounts for 5-15% of the mass of the high-barrier antibacterial multilayer polymer film.
[0034] Furthermore, the mass ratio of antibacterial nanoparticles to modified polyethylene in the third modified polyethylene functional antibacterial sustained-release layer is 1:(20-65); the third modified polyethylene functional antibacterial sustained-release layer accounts for 5-10% of the mass of the high-barrier antibacterial multilayer polymer film.
[0035] Furthermore, the other functional layers are one or more of polyamide, polyethylene, polypropylene, ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, polyethylene terephthalate, polyvinylidene chloride, polyester, and polyolefin elastomer.
[0036] A second aspect of the present invention provides a method for preparing a high-barrier antibacterial multilayer polymer film, comprising: S1. Loading functional antibacterial substances into mesoporous nanoparticles through chemical encapsulation technology to obtain antibacterial nanoparticles; S2. Using graft modification method combined with precision screw extrusion granulation technology to prepare modified polyethylene masterbatch; S3, physically blending the antibacterial nanoparticles and modified polyethylene masterbatch, and then granulating them by precision screw extrusion to obtain modified polyethylene functional antibacterial sustained-release masterbatch; S4. Based on the multi-layer gradient structure design, the modified polyethylene functional antibacterial sustained-release masterbatch is added into the melt extruder, and combined with the multi-layer co-extrusion film making technology, a high-barrier antibacterial multi-layer polymer film is obtained.
[0037] In step S1, the functional antibacterial substance includes one or more organic phenolic acids such as tannic acid, citric acid, tartaric acid, and fumaric acid; the mass ratio of the functional antibacterial substance to the mesoporous nanoparticles is 1:(0.01-3); the mesoporous nanoparticles include one or two of mesoporous zinc oxide and mesoporous titanium dioxide.
[0038] In step S2, the polyethylene density is 0.90-0.96 g / cm 3 , melt index is 0.2-1.0g / min; precision screw extrusion granulation temperature control accuracy does not exceed ±1°C; granulation temperature is 160-200°C; screw speed is 180-400rpm; grafted modification substances include one or two of maleic anhydride, acrylic acid, and vinyltrimethoxysilane; the grafting rate of modified polyethylene masterbatch is 0.6-1.5%.
[0039] In step S3, the vacuum drying temperature of the antibacterial nanoparticles and the modified polyethylene masterbatch is 50-80°C, and the mass ratio is 1:(10-100); the twin-screw granulation temperature is 160-200°C; the screw speed is 250-450rpm; and the dispersant is one or two of polyethylene wax, zinc stearate, and calcium stearate.
[0040] In step S4, the multilayer gradient structure of the high-barrier antibacterial multilayer polymer membrane is, from the inside to the outside, the first modified polyethylene functional antibacterial sustained-release layer, the second modified polyethylene functional antibacterial sustained-release layer, the third modified polyethylene functional antibacterial layer, and other functional layers. The overall number of layers of the polymer membrane is 4-13 layers.
[0041] The high barrier and antibacterial multilayer polymer film is used for food packaging and preservation. The food can be livestock, poultry, aquatic products, eggs, dairy products, vegetables and the like.
[0042] Example 1 The method for preparing the high-barrier antibacterial multilayer polymer film according to the first embodiment of the present invention comprises the following steps: S1. Loading functional antibacterial substances into mesoporous nanoparticles through chemical encapsulation technology to obtain antibacterial nanoparticles; More specifically, 100 parts of mesoporous nano zinc oxide were weighed and uniformly dispersed in a reactor containing 500 parts of anhydrous ethanol solution, magnetically stirred for 30 minutes at a stirring speed of 350 r / min, and then 1 part of concentrated ammonia water was added. Stirring was continued for 30 minutes, and 2 parts of tannic acid, 1 part of tartaric acid, and 1.5 parts of fumaric acid were added in sequence. Ultrasonic treatment was performed for 20 minutes, and the mixture was heated at 45°C for 3 hours. The precipitate was removed by centrifugation to obtain antibacterial nanoparticles.
[0043] S2. Using graft modification method combined with precision screw extrusion granulation technology to prepare modified polyethylene masterbatch; More specifically, 100 parts of a melt index of 1.0 g / min and a density of 0.92 / cm 3 The polyethylene masterbatch, 10 parts of maleic anhydride, 5 parts of acrylic acid and 2 parts of dicumyl peroxide were added into the granulation equipment in sequence. The granulation temperature was 180°C, the screw speed was set to 400 rpm, and vacuum devolatilization was performed to remove unreacted organic molecules to obtain modified polyethylene masterbatch.
[0044] S3, physically blending the antibacterial nanoparticles and modified polyethylene masterbatch, and then granulating them by precision screw extrusion to obtain modified polyethylene functional antibacterial sustained-release masterbatch; More specifically, the antibacterial nanoparticles obtained by S1 and the modified polyethylene masterbatch prepared by S2 were vacuum dried at 55°C for 8 hours to obtain a dry product; 5 parts of antibacterial nanoparticles, 100 parts of modified polyethylene masterbatch, 5 parts of polyethylene wax, and 1 part of calcium stearate were weighed and added to the granulation equipment respectively, the twin-screw granulation temperature was set to 180°C, the screw speed was set to 450rpm, and vacuum devolatilization was performed to remove unreacted organic molecules to obtain modified polyethylene functional antibacterial masterbatch.
[0045] S4. Based on the multi-layer gradient structure design, the modified polyethylene functional antibacterial slow-release masterbatch is added to the melt extruder, and combined with the multi-layer co-extrusion film-making technology, a high-barrier antibacterial multi-layer polymer film is obtained; More specifically, 350 parts of modified polyethylene functional antibacterial masterbatch obtained in S3, 300 parts of polyamide masterbatch and 400 parts of modified polyethylene masterbatch were weighed and added into the melt extruder respectively. The temperature of the multi-layer co-extrusion film feed section was set to 95°C, the compression section temperature was set to 150°C, the homogenization section temperature was set to 200°C, and the die pressure was set to 10 MPa. A high-barrier antibacterial multilayer polymer film was obtained by the upblowing process. The multilayer structure is, from the inside to the outside, 0.5% of the first modified polyethylene functional antibacterial sustained-release layer, 1.5% of the second modified polyethylene functional antibacterial sustained-release layer, 2.0% of the third modified polyethylene functional antibacterial sustained-release layer, the polyamide barrier layer, and the modified polyethylene layer, and the mass ratio is 1:1.2:1:3:4.
[0046] Example 2 The preparation method of the high-barrier and antibacterial multilayer polymer film described in this embodiment differs from that in Example 1 only in that: in step S4, the multilayer structure is composed of a first modified polyethylene functional antibacterial sustained-release layer of 0.5%, a second modified polyethylene functional antibacterial sustained-release layer of 1.0%, and a third modified polyethylene functional antibacterial sustained-release layer of 1.5% from the inside to the outside; the rest are consistent with Example 1.
[0047] Comparative Example 1 The preparation method of the high-barrier antibacterial multilayer polymer film described in this comparative example differs from that in Example 1 only in that: in step S4, the multilayer structure is composed of a first modified polyethylene functional antibacterial sustained-release layer of 0.5%, a second modified polyethylene functional antibacterial sustained-release layer of 0.5%, and a third modified polyethylene functional antibacterial sustained-release layer of 0.5% from the inside to the outside; the rest are consistent with Example 1.
[0048] Comparative Example 2 S1. Use graft modification method combined with precision screw extrusion granulation technology to prepare modified polyethylene masterbatch; Specifically, 2.0 kg of a melt index of 1.0 g / min and a density of 0.92 / cm 3 The polyethylene masterbatch, 200g maleic anhydride, 100g acrylic acid and 20g dicumyl peroxide were added to the granulation equipment in sequence. The granulation temperature was 180°C, the screw speed was set to 400rpm, and vacuum devolatilization was performed to remove unreacted organic molecules to obtain modified polyethylene masterbatch.
[0049] S2. Based on the multi-layer gradient structure design, the modified polyethylene masterbatch is added to the melt extruder and combined with the multi-layer co-extrusion film-making technology to obtain a high-barrier multi-layer polymer film; Specifically, 300 parts of polyamide masterbatch and 400 parts of modified polyethylene masterbatch were weighed and added into the melt extruder respectively. The temperature of the multi-layer co-extrusion film feed section was set to 95°C, the compression section temperature was set to 150°C, the homogenization section temperature was set to 200°C, and the die pressure was set to 10Mpa. A high-barrier and antibacterial multi-layer polymer film was obtained through the upblowing process. The multi-layer structure consists of the first modified polyethylene layer, the second modified polyethylene layer, the third modified polyethylene layer, the polyamide barrier layer, and the modified polyethylene layer from the inside to the outside, and the mass ratio is 1:1.2:1:3:4.
[0050] Comparative Example 3 S1. Loading functional antibacterial substances into mesoporous nanoparticles through chemical encapsulation technology to obtain antibacterial nanoparticles; Weigh 100 parts of mesoporous nano-zinc oxide and evenly disperse them in a reactor containing 500 parts of anhydrous ethanol solution. Stir magnetically for 30 minutes at a stirring speed of 350 r / min. Then add 1 part of concentrated ammonia water and continue stirring for 30 minutes. Then add 2 parts of tannic acid, 1 part of tartaric acid, and 1.5 parts of fumaric acid in sequence. Ultrasonic treatment for 20 minutes, heat at 45°C for 3 hours, and centrifuge to remove the precipitate to obtain antibacterial nanoparticles.
[0051] S2. Based on a multi-layer gradient structure design, antibacterial nanoparticles and polyethylene masterbatch are added to a melt extruder, combined with multi-layer co-extrusion film-making technology to obtain a high-barrier multi-layer polymer film; Specifically, 16 parts of antibacterial nanoparticles obtained in S1, 300 parts of polyamide masterbatch and 400 parts of polyethylene masterbatch were weighed and added into the melt extruder respectively. The temperature of the multi-layer co-extrusion film feed section was set to 95°C, the compression section temperature was set to 150°C, the homogenization section temperature was set to 200°C, and the die pressure was set to 10 MPa. A high-barrier antibacterial multilayer polymer film was obtained by the upblowing process. The multilayer structure was composed of a 0.5% polyethylene antibacterial sustained-release layer, a 1.0% polyethylene antibacterial sustained-release layer, a 1.5% antibacterial sustained-release layer, a polyamide barrier layer, and a modified polyethylene layer from the inside to the outside, and the mass ratio was 1:1.2:1:3:4.
[0052] The high-barrier multilayer polymer films prepared in the above examples and comparative examples were tested, and the following data were obtained: Table 1 Antibacterial rate and water vapor permeability of high barrier antibacterial multilayer polymer films
[0053] The above results show that mesoporous nanoparticles loaded with antibacterial substances can be dispersed in polyethylene masterbatch modified with organic molecules such as maleic anhydride. After a multi-layer gradient design, three layers of modified polyethylene functional antibacterial layers with different antibacterial substance contents are obtained from the inside to the outside. The synergistic regulation of the release path length of the antibacterial substance achieves a balance between high-efficiency antibacterial and high barrier requirements. It has application potential in inhibiting food spoilage bacteria, especially Pseudomonas, the dominant spoilage bacteria in livestock and poultry meat, and provides a material basis for food processing, packaging and preservation technology.
[0054] The number of equipment and processing scales described here are used to simplify the description of the present invention. Applications, modifications and variations of the nano-titanium dioxide antibacterial packaging material with high tannic acid loading and its preparation method and use will be obvious to those skilled in the art.
[0055] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.
Claims
1. A high-barrier antibacterial multilayer polymer film, characterized by: The high barrier and antibacterial multilayer polymer film comprises a first modified polyethylene functional antibacterial sustained-release layer, a second modified polyethylene functional antibacterial sustained-release layer, a third modified polyethylene functional antibacterial layer, and other functional layers; The first modified polyethylene functional antibacterial sustained-release layer, the second modified polyethylene functional antibacterial sustained-release layer, and the third modified polyethylene functional antibacterial layer are all made of antibacterial nanoparticles and modified polyethylene.
2. The high-barrier and antibacterial multilayer polymer film according to claim 1, characterized in that: The mass ratio of antibacterial nanoparticles to modified polyethylene in the first modified polyethylene functional antibacterial sustained-release layer is 1:(100-200); the first modified polyethylene functional antibacterial sustained-release layer accounts for 3-10% of the mass of the high-barrier antibacterial multi-layer polymer film.
3. The high-barrier and antibacterial multilayer polymer film according to claim 1, characterized in that: The mass ratio of antibacterial nanoparticles to modified polyethylene in the second modified polyethylene functional antibacterial sustained-release layer is 1:(66-100); the second modified polyethylene functional antibacterial sustained-release layer accounts for 5-15% of the mass of the high-barrier antibacterial multilayer polymer film.
4. The high-barrier and antibacterial multilayer polymer film according to claim 1, characterized in that: The mass ratio of antibacterial nanoparticles to modified polyethylene in the third modified polyethylene functional antibacterial sustained-release layer is 1:(20-65); the third modified polyethylene functional antibacterial sustained-release layer accounts for 5-10% of the mass of the high-barrier antibacterial multilayer polymer film.
5. A method for preparing a high-barrier and antibacterial multilayer polymer film, according to any one of claims 1 to 4, characterized in that: S1. preparing antibacterial nanoparticles by chemically encapsulating functional antibacterial substances and mesoporous nanoparticles; S2, polyethylene and graft modified substances are grafted and modified by a method combined with a precision screw extrusion process to prepare a modified polyethylene masterbatch; S3, physically blending the antibacterial nanoparticles with modified polyethylene masterbatch in different proportions, and adding a dispersant to prepare multiple groups of modified polyethylene antibacterial sustained-release masterbatch; S4. The modified polyethylene antibacterial sustained-release masterbatch and other functional raw materials are subjected to multi-layer co-extrusion film-making technology to produce a high-barrier antibacterial multi-layer polymer film having a first modified polyethylene functional antibacterial sustained-release layer, a second modified polyethylene functional antibacterial sustained-release layer, a third modified polyethylene functional antibacterial layer, and other functional layers.
6. The method for preparing a high-barrier antibacterial multilayer polymer film according to claim 5, characterized in that: In S1: the functional antibacterial substance is one or more of tannic acid, citric acid, tartaric acid, and fumaric acid; the mass ratio of the functional antibacterial substance to the mesoporous nanoparticles is 1:(0.01-3); the mesoporous nanoparticles are one or two of mesoporous zinc oxide and mesoporous titanium dioxide.
7. The method for preparing a high-barrier antibacterial multilayer polymer film according to claim 5, characterized in that: In S2: the polyethylene density is 0.90-0.96 g / cm 3 , melt index is 0.2-1.0g / min; precision screw extrusion granulation temperature control accuracy does not exceed ±1°C; granulation temperature is 160-200°C; screw speed is 180-400rpm; grafted modification substances include one or two of maleic anhydride, acrylic acid, and vinyltrimethoxysilane; the grafting rate of modified polyethylene masterbatch is 0.6-1.5%.
8. The method for preparing a high-barrier antibacterial multilayer polymer film according to claim 5, characterized in that: In S3: the vacuum drying temperature of the antibacterial nanoparticles and the modified polyethylene masterbatch is 50-80°C, and the mass ratio is 1:(10-100); the twin-screw granulation temperature is 160-200°C; the screw speed is 250-450rpm; the dispersant is one or two of polyethylene wax, zinc stearate, and calcium stearate.
9. The method for preparing a high-barrier antibacterial multilayer polymer film according to claim 5, characterized in that: In S4: the number of layers of the high-barrier antibacterial multilayer polymer film is 4-13; the thickness of the first modified polyethylene functional antibacterial sustained-release layer, the second modified polyethylene functional antibacterial sustained-release layer and the third modified polyethylene functional antibacterial layer in the high-barrier antibacterial multilayer polymer film are all 10-50 μm.
10. Use of a high-barrier and antibacterial multilayer polymer film, the high-barrier and antibacterial multilayer polymer film according to any one of claims 1 to 4, characterized in that: The high-barrier and antibacterial multi-layer polymer film is used for food packaging.