A multilayer film with high antibacterial resistance and preparation method thereof

Abstract

The present invention discloses a multilayer film with high antibacterial resistance and a preparation method thereof. The key points of the technical scheme are that the multilayer film with high antibacterial resistance consists of three layers, namely an antibacterial layer, a barrier layer and a support layer, wherein the antibacterial layer is located at the outermost layer of the film and adopts a material containing antibacterial components, the barrier layer is located below the antibacterial layer, and the support layer is located below the barrier layer; the present invention solves the problem that the antibacterial effect of traditional antibacterial films decays over time by adopting self-repairing materials and sustained-release technology; the sustained-release agent is designed to control the release rate of the antibacterial components so that it maintains a stable antibacterial effect during long-term use, and by selecting a high-strength support layer material and adopting an optimized processing technology, the tensile strength, tear resistance and wear resistance of the film are significantly improved, and the peeling or damage of the antibacterial layer caused by the influence of the external environment (such as friction, ultraviolet radiation, etc.) is avoided, thereby improving the long-term stability and service life of the film, and having strong market potential.

Description

Technical Field

[0001] The invention relates to the technical field of antibacterial high-resistance multilayer films, and in particular to a multilayer film with antibacterial high resistance and a preparation method thereof. Background Art

[0002] With the widespread application of antibacterial high-resistance films in food packaging, medical and health care, personal care and other fields, the market's requirements for such films are constantly increasing. Especially in the food industry, consumers' attention to food safety and hygiene is increasing. Antibacterial films are widely used to extend the shelf life of food and inhibit bacterial growth, thereby effectively reducing the risk of food contamination and deterioration. At the same time, with the improvement of people's living standards, personal care products have also put forward higher demands on antibacterial films, especially in the fields of skin care, sanitary products, medical equipment packaging, etc. Antibacterial films not only need to have the ability to prevent the spread of bacteria, but also should have good breathability, comfort and adaptability.

[0003] However, the antibacterial high-resistance film of the prior art still has some defects, which are mainly manifested in the following aspects:

[0004] 1. The antibacterial effect of most antibacterial films is difficult to maintain for a long time. Especially in harsh environments, the antibacterial performance will gradually weaken. The release rate of common antibacterial materials (such as nanosilver) is unstable and cannot provide lasting protection.

[0005] 2. Antibacterial ingredients often change the structure of the film, affecting its gas and water vapor barrier properties. In applications with high barrier requirements, how to balance the antibacterial effect and barrier properties is a technical challenge.

[0006] 3. The antibacterial layer of the antibacterial film is easily damaged, resulting in a decrease in the durability and mechanical strength of the film. Especially in applications requiring high mechanical properties, the wear resistance and strength of the antibacterial film are insufficient, affecting its overall function;

[0007] To solve the above problems, we propose a multilayer film with high antibacterial resistance and a preparation method thereof. Summary of the invention

[0008] In view of the deficiencies in the prior art, the present invention provides a multilayer film with high antibacterial resistance and a preparation method thereof, which solves the problems raised in the background technology.

[0009] The above technical objectives of the present invention are achieved through the following technical solutions:

[0010] A multilayer film with high antibacterial resistance, the multilayer film with high antibacterial resistance consists of three layers, namely an antibacterial layer, a barrier layer and a support layer, wherein the antibacterial layer is located at the outermost layer of the film and adopts a material containing antibacterial components, the barrier layer is located below the antibacterial layer, and the support layer is located below the barrier layer.

[0011] Preferably, the antibacterial layer is prepared by the following steps:

[0012] a. Select antibacterial ingredients, which are metal ions such as silver, copper, zinc, natural plant extracts or their complexes, and can effectively inhibit the growth of bacteria, fungi and other pathogenic microorganisms to ensure the antibacterial effect. The mass fraction of the antibacterial ingredients is 1-10% to ensure the antibacterial effect;

[0013] b. Encapsulating the antibacterial component by a nano-encapsulation technology or a cross-linked polymer encapsulation technology, the specific steps are as follows:

[0014] The antibacterial component is mixed with a polymer material (such as polyethylene, polypropylene, polyurethane, etc.) at a ratio of 1:5-1:10 to prepare an antibacterial solution;

[0015] The antibacterial ingredients are encapsulated in micron- or nano-scale polymer particles by solvent evaporation, sol-gel method or other encapsulation techniques to ensure uniform distribution of the antibacterial ingredients and control their release rate. The particle size is 50-200nm;

[0016] Removing the solvent by freeze drying or vacuum drying, the residual solvent content after removal is controlled below 0.5%, ensuring the stability of the encapsulated antibacterial components and preventing volatilization;

[0017] The encapsulated antibacterial component is mixed with a base polymer material (such as polyethylene, polypropylene, etc.) to form a coating material with antibacterial function, and the concentration of the coating material is 10-50%;

[0018] The coating material is uniformly coated on the outer surface of the film by a solvent coating method, a blade coating method or a spray coating method, and the uniformity and thickness of the coating are controlled during the coating process, and the coating thickness is 0.1-10 μm;

[0019] The coated film is heat treated or UV cured at a temperature of 100-180°C for 10-30 minutes, or UV cured at an intensity of 100-200 mJ / cm 2 , to further improve the adhesion and stability of the coating, ensuring that the antibacterial layer can be effective for a long time during the use of the membrane.

[0020] Preferably, the barrier layer is prepared by the following steps:

[0021] a. Select polymer materials, such as polyester (PET), polypropylene (PP), polyvinyl chloride (PVC), polyamide (PA) or their composite materials, with good gas and vapor barrier properties. The specific selection should be based on the application scenario of the film, and high barrier materials should be given priority. The selective barrier permeability of oxygen, carbon dioxide and water vapor is 0.01-0.5g / m2 day;

[0022] b. Forming the barrier material into a film by solution impregnation, coextrusion or hot pressing;

[0023] Among them, the solution impregnation method: dissolve the barrier polymer material in a solvent, soak the substrate, and then remove the solvent by hot air drying, vacuum drying, etc. to obtain a uniform film; the solvent concentration is 5-15%;

[0024] Co-extrusion method: different polymer materials are co-extruded through an extruder at high temperature to form a multi-layer composite film, which includes a barrier layer, an antibacterial layer and a support layer. This method can ensure that the thickness of the barrier layer is uniform and firmly combined with other layer materials. The thickness of the barrier layer is 1-100μm;

[0025] Hot pressing method: The barrier layer material and other layer materials are heated to a plastic state, and formed into a film through a pressing process, and good adhesion between the layers is ensured;

[0026] C. The prepared barrier layer is combined with the antibacterial layer and the support layer by heat pressing, laminating or bonding. The bonding temperature is controlled at 150-200°C and the pressing pressure is 5-10MPa to ensure the bonding strength between the three layers of materials and avoid delamination or structural instability.

[0027] Preferably, the support layer is prepared by the following steps:

[0028] a. Select high-strength polymer materials, such as polyethylene (PE), polyester (PET), polypropylene (PP), polyamide (PA) or their composite materials, to ensure that the film has sufficient tensile strength, tear resistance, impact resistance and wear resistance during use, with a tensile strength of 50-150MPa and a tear strength of 10-40N;

[0029] b. preparing the support layer material into a film by melt extrusion, hot pressing or lamination;

[0030] Among them, melt extrusion method: heating the support material to a molten state, extruding it through an extrusion die to obtain a thin film support layer, the support layer thickness is 5-100 μm;

[0031] Hot pressing method: the support material is heated to a softened state, and then formed into a thin film by mechanical pressure, and the thickness of the film is ensured to be uniform;

[0032] Lamination method: stacking the support material with other layer materials and bonding them into a multi-layer structure by high-temperature pressing;

[0033] c. Combine the support layer with the antibacterial layer and the barrier layer by a process of hot pressing, lamination or bonding. The bonding temperature is controlled at 150-200°C and the pressing pressure is 5-10MPa to ensure that the support layer provides the necessary mechanical strength for the multilayer film to prevent the film from breaking or deforming during use.

[0034] Preferably, the thickness of the multilayer film with antibacterial high resistance is 10-200 μm, wherein:

[0035] The thickness of the antimicrobial layer is 0.1-10 μm, which can provide a long-lasting antimicrobial effect while maintaining the flexibility of the film;

[0036] The thickness of the barrier layer is 1-100 μm, ensuring that the film has sufficient gas and water vapor barrier properties;

[0037] The thickness of the support layer is 5-100 μm, which can provide the membrane with the required mechanical strength and ensure the durability of the membrane in practical applications.

[0038] Preferably, the antibacterial layer is enhanced by a self-repairing material, and the self-repairing material is selected from a polymer material with a self-healing function, which can automatically repair the antibacterial layer during the use of the membrane, so that the antibacterial layer maintains an antibacterial effect for a long time during use. The specific steps are as follows:

[0039] a. Selecting polymer materials with self-healing function, including but not limited to polyurethane (PU), epoxy resin (EP), polyvinyl alcohol (PVA), etc., which have self-healing function;

[0040] The selection range of the self-healing polymer is 1-5% by mass, and it is properly formulated according to the needs;

[0041] b. Compounding the self-healing polymer with the antibacterial component, the compounding ratio is: the mass ratio of the self-healing polymer to the antibacterial component is 1:10 to 1:20, wherein the antibacterial component includes metal ions (such as silver, copper, zinc) or plant extracts (such as tea polyphenols, ginkgo leaf extract), etc., and the mass fraction of the antibacterial component is controlled in the range of 2-5% to ensure its good antibacterial effect;

[0042] c. Fully mix the self-healing polymer and the antibacterial component by physical mixing or solution mixing to form a self-healing antibacterial composite material, and control the mixing temperature between 80-120°C to ensure that the two are fully combined without affecting the activity of the antibacterial component;

[0043] d. Hot-melt fusion of the self-repairing antibacterial composite material and a film substrate polymer (such as polyethylene or polypropylene) to form an antibacterial layer. In this step, the hot-melt fusion temperature is 180-220° C. and the pressure is controlled at 1-3 MPa to ensure that the composite material is evenly distributed on the film surface and has good adhesion.

[0044] e. Optimizing the self-healing properties of the antibacterial layer through an annealing or curing process at a temperature of 100-150°C for 10-30 minutes to enhance the microstructure of the self-healing polymer and thus improve the self-healing ability of the membrane. Through this process, the membrane can restore its original antibacterial properties using the self-healing material after scratches or damage on the surface;

[0045] f. In actual application, when the antibacterial layer is damaged externally, the self-healing material automatically restores its original antibacterial properties through chemical reactions (such as reconnection of polyurethane chain segments) or physical processes (such as changes in temperature or humidity activating the self-healing function), ensuring that the antibacterial layer can function for a long time. The self-healing cycle can reach 10-50 times, and the repair process will not significantly reduce the antibacterial performance.

[0046] Preferably, the antibacterial layer is designed with a sustained-release agent to ensure that the release rate of the antibacterial component is stable over a long period of time, to avoid the rapid loss of the antibacterial component, and to ensure the sustainability of the antibacterial effect. The specific steps are as follows:

[0047] a. Selecting a suitable sustained-release agent material, which is a polymer material or inorganic material with controlled-release properties, capable of slowly releasing antibacterial components over a long period of time, specifically including but not limited to natural polymer materials: such as chitosan, alginate, gelatin, etc. These natural polymer materials have good biocompatibility and sustained-release properties;

[0048] Synthetic polymer materials: such as polylactic acid (PLA), polyvinyl alcohol (PVA), polyurethane (PU), etc. These synthetic polymer materials form a network structure through physical or chemical cross-linking, which can control the release of antibacterial components;

[0049] Inorganic materials: such as silicon dioxide (SiO2), bentonite, etc., as carriers, can effectively regulate the release rate of antibacterial ingredients;

[0050] b. Compounding the sustained-release agent with the antibacterial component, the compounding ratio is: the mass ratio of the sustained-release agent to the antibacterial component is 2:1 to 5:1, wherein the mass fraction of the antibacterial component is controlled at 1-10% to ensure its antibacterial effect, and at the same time, through the presence of the sustained-release agent, the release rate of the antibacterial component is controlled to prolong its effectiveness;

[0051] c. uniformly mixing the sustained-release agent and the antibacterial component using a solution method, a melt blending method or an impregnation method to obtain a sustained-release antibacterial composite material;

[0052] d. Hot-melt the sustained-release antibacterial composite material and the film substrate polymer (such as polyethylene, polypropylene) to form an antibacterial layer. In this step, the hot-melt fusion temperature is 180-220° C. and the pressure is controlled at 1-3 MPa to ensure that the composite material is evenly distributed on the film surface and has good adhesion;

[0053] e. Control the release rate of the antimicrobial component by adjusting the content and structure of the sustained-release agent to ensure that the antimicrobial effect can last for 30 days to 12 months, depending on the type of antimicrobial component, the application environment of the membrane and the characteristics of the sustained-release agent. The sustained-release rate can be further adjusted by changing the cross-linking degree or particle size of the material;

[0054] f. By optimizing the design of sustained-release agents, the release of antibacterial ingredients can be kept stable during the use of the membrane, avoiding the antibacterial ingredients from being released too quickly in a short period of time, ensuring that the antibacterial effect remains long-lasting and evenly distributed throughout the entire use cycle. For example, antibacterial ingredients can be coated with polymer microspheres, or antibacterial ingredients can be slowly released in different layers through a layered structure to extend the service life of the membrane;

[0055] g. By controlling the release curve of the antibacterial ingredients, the continuity of the antibacterial effect can be ensured and the rapid loss of antibacterial ingredients can be avoided. The specific implementation methods are:

[0056] Dynamic release control: sustained-release agents activate or regulate the release rate of antimicrobial ingredients through external environmental stimuli (such as temperature, humidity or pH);

[0057] Static release control: The sustained-release agent regulates the release rate of the antimicrobial ingredients through its inherent physical or chemical structure (such as micropores, cross-linking points, etc.).

[0058] The present invention also provides a method for preparing a multilayer film with high antibacterial resistance, comprising the following steps:

[0059] S1. selecting and preparing an antibacterial component, encapsulating the antibacterial component using a nano-encapsulation technology or a cross-linked polymer encapsulation technology, and controlling the release rate of the antibacterial component;

[0060] S2. Select a suitable polymer material and prepare a barrier layer material, and prepare the barrier layer by a solution impregnation method, a co-extrusion method or a hot pressing method;

[0061] S3, selecting a material for the support layer and preparing the support layer by a melt extrusion method, a hot pressing method or a lamination method;

[0062] S4, arranging the antibacterial layer, the barrier layer and the support layer in a predetermined order by a co-extrusion method, a hot pressing method or a lamination method, and combining them into a shape;

[0063] S5. Cooling, cutting and winding the prepared multilayer film to obtain a multilayer film with antibacterial effect, excellent barrier properties and high mechanical strength.

[0064] Preferably, the release rate of the antibacterial component is adjusted by a sustained-release control agent so that the antibacterial component is continuously released during use to maintain a long-term effective antibacterial effect. The specific steps are as follows:

[0065] a. Selecting a sustained-release control agent, which is a polymer material or inorganic material that can adjust the release rate of the antibacterial component. Common sustained-release control agents include chitosan, polylactic acid, polyvinyl alcohol, etc.;

[0066] b. Compounding the sustained-release control agent with the antibacterial component at a ratio of 1:5 to 1:10 to ensure that the antibacterial component can be continuously released over a long period of time;

[0067] c. coating or embedding the composite material into the membrane substrate by a solution method, melt blending method or impregnation method to form an antibacterial layer;

[0068] d. Adjust the structure of the sustained-release control agent (such as cross-linking degree, pore structure, etc.) according to demand, so as to control the release rate of the antibacterial component and ensure the continuity of the antibacterial effect;

[0069] e. Through antibacterial performance testing and antibacterial ingredient release testing, ensure that the antibacterial effect can be sustained and remain stable to avoid the rapid loss of antibacterial ingredients.

[0070] In summary, the present invention mainly has the following beneficial effects:

[0071] 1. By adopting self-healing materials and sustained-release technology, the present invention can effectively prolong the antibacterial effect of the antibacterial film. The self-healing polymer can automatically repair when damage or scratches occur on the surface of the film, maintain the integrity of the antibacterial layer, and avoid rapid attenuation of the antibacterial effect due to damage. The sustained-release agent design can control the release rate of the antibacterial component, so that it maintains a continuous and stable antibacterial effect during long-term use, thereby solving the problem of the antibacterial effect decreasing over time in the prior art.

[0072] 2. The present invention maintains the excellent barrier properties of the film while ensuring the antibacterial function by precisely designing the multi-layer structure of the film. The antibacterial layer and the barrier layer are optimized through co-extrusion, solution impregnation and other processes to ensure that the antibacterial components will not excessively affect the microstructure or porosity of the film, thereby avoiding a significant decrease in the barrier properties of the film when the antibacterial components are added. Especially in applications such as food packaging that have high requirements for gas and water vapor barrier, the present invention can balance the antibacterial function with high barrier properties and improve the comprehensive performance of the film.

[0073] 3. By strengthening the mechanical properties of the supporting layer material, the present invention significantly improves the durability and resistance to external physical damage of the antibacterial film. The supporting layer of the membrane has high tensile strength, tear resistance and wear resistance through the selection of high-strength materials and optimization of processing technology (such as melt extrusion, hot pressing molding, etc.). This design effectively avoids the peeling or damage of the antibacterial layer caused by the external environment (such as friction, ultraviolet radiation, etc.) during long-term use, thereby ensuring the long-term stability and overall function of the membrane. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Figure 1 It is a schematic diagram of the cross-sectional structure of the antibacterial high-resistance multilayer film of the product of the present invention.

[0075] In the figure: 1. antibacterial layer; 2. barrier layer; 3. support layer. DETAILED DESCRIPTION

[0076] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0077] The following examples are used to illustrate the present invention, but they cannot be used to limit the scope of protection of the present invention. The conditions in the examples can be further adjusted according to specific conditions. Simple improvements to the method of the present invention under the premise of the concept of the present invention belong to the scope of protection claimed in the present invention.

[0078] refer to Figure 1 , a multilayer film with antibacterial high resistance, the multilayer film with antibacterial high resistance consists of three layers, namely an antibacterial layer, a barrier layer and a support layer, wherein:

[0079] Antibacterial layer: located at the outermost layer of the film, using materials containing antibacterial ingredients, which can effectively inhibit the growth of pathogenic microorganisms such as bacteria and fungi, ensuring that the film maintains antibacterial effects for a long time during use. The present invention can effectively extend the antibacterial effect of the antibacterial film by using self-healing materials and sustained-release technology. The self-healing polymer can automatically repair when damage or scratches occur on the surface of the film, maintain the integrity of the antibacterial layer, and avoid rapid attenuation of the antibacterial effect due to damage; the sustained-release agent design can control the release rate of the antibacterial ingredients, so that it maintains a continuous and stable antibacterial effect during long-term use, thereby solving the problem of the antibacterial effect decreasing over time in the prior art;

[0080] Barrier layer: located below the antibacterial layer, using materials with excellent gas and water vapor barrier properties, and accurately designing the multi-layer structure of the film to ensure the antibacterial function while maintaining the excellent barrier properties of the film. The antibacterial layer and the barrier layer are optimized by co-extrusion, solution impregnation and other processes to ensure that the antibacterial component does not excessively affect the microstructure or porosity of the film, thereby avoiding a significant decrease in the barrier properties of the film when the antibacterial component is added. Especially in applications such as food packaging that have high requirements for gas and water vapor barrier, the present invention can balance the antibacterial function and high barrier properties, and improve the comprehensive performance of the film;

[0081] Support layer: located below the barrier layer, as the core support layer of the membrane, it gives the membrane sufficient mechanical strength, tear resistance, impact resistance and wear resistance, ensuring the stability and durability of the membrane during use. By strengthening the mechanical properties of the support layer material, the present invention significantly improves the durability and resistance to external physical damage of the antibacterial membrane. The support layer of the membrane has high tensile strength, tear resistance and wear resistance through the selection of high-strength materials and optimization of processing technology (such as melt extrusion, hot pressing molding, etc.), avoiding the peeling or damage of the antibacterial layer due to external environmental factors such as friction and ultraviolet radiation, thereby ensuring the long-term stability and overall function of the membrane.

[0082] A method for preparing a multilayer film with high antibacterial resistance comprises the following steps:

[0083] S1. selecting and preparing an antibacterial component, encapsulating the antibacterial component using a nano-encapsulation technology or a cross-linked polymer encapsulation technology, and controlling the release rate of the antibacterial component;

[0084] S2. Select a suitable polymer material and prepare a barrier layer material, and prepare the barrier layer by a solution impregnation method, a co-extrusion method or a hot pressing method;

[0085] S3, selecting a material for the support layer and preparing the support layer by a melt extrusion method, a hot pressing method or a lamination method;

[0086] S4, arranging the antibacterial layer, the barrier layer and the support layer in a predetermined order by a co-extrusion method, a hot pressing method or a lamination method, and combining them into a shape;

[0087] S5. Cooling, cutting and winding the prepared multilayer film to obtain a multilayer film with antibacterial effect, excellent barrier properties and high mechanical strength.

[0088] Example 1: Food packaging application

[0089] 1. The multilayer film with antibacterial high resistance is composed of three layers, namely, an antibacterial layer, a barrier layer and a support layer:

[0090] Antibacterial layer: It uses polyethylene material containing silver ion antibacterial ingredients. Through self-repair technology and slow-release design, it ensures the antibacterial effect of the membrane in long-term use. The self-healing polymer can automatically repair when the membrane surface is damaged, maintain the integrity of the antibacterial layer, and avoid the attenuation of the antibacterial effect due to external damage;

[0091] Barrier layer: The polyester (PET) material with high gas and water vapor barrier properties is used to ensure that the film has excellent barrier properties, and is particularly suitable for food packaging fields that have high requirements for gas and water vapor;

[0092] Support layer: Polypropylene (PP) material is selected, and the tensile strength and durability of the film are enhanced through the melt extrusion film-forming process to prevent the film from being damaged due to external physical impact during use.

[0093] 2. Preparation of antibacterial layer

[0094] Silver ions are used as antibacterial ingredients and are encapsulated in a polyethylene substrate using nano-encapsulation technology, with a silver ion mass fraction of 5%;

[0095] Add sustained-release agents (such as cyclodextrin complexes) to control the release rate of antibacterial ingredients to ensure that the antibacterial effect of the membrane is stable during long-term use;

[0096] Self-healing polymers add microcapsule materials to the membrane surface, allowing the membrane to automatically repair itself when scratched or damaged, thereby maintaining the membrane's antibacterial function and structural integrity.

[0097] 3. Preparation of barrier layer

[0098] Made of polyester (PET) material, oxygen permeability is 0.03g / m 2 ·day, water vapor transmission rate is 0.2g / m 2 day, meeting the strict barrier performance requirements of food packaging;

[0099] The barrier layer was prepared by solution dipping method with a film thickness of 50 μm.

[0100] 4. Preparation of support layer

[0101] Polypropylene (PP) material is used, and the film is formed by melt extrusion technology, with a film thickness of 40μm;

[0102] The support layer strengthens the tensile strength, tear resistance and abrasion resistance of the film, ensuring the stability of the film during packaging, transportation and use.

[0103] 5. Performance Testing

[0104] Antibacterial effect: After 30 days of bacterial inhibition test, the membrane can still effectively inhibit the growth of Escherichia coli and Staphylococcus aureus;

[0105] Barrier performance: The test results show that the oxygen permeability is 0.03g / m 2 ·day, water vapor transmission rate is 0.2g / m 2 day, in line with food packaging requirements;

[0106] Mechanical properties: tensile strength is 85MPa and tear strength is 18N, ensuring the durability of the film.

[0107] Example 2: Application in the medical and health field

[0108] 1. The antibacterial film is designed for use in the medical and health field and adopts a multi-layer structure:

[0109] Antibacterial layer: A self-healing polymer containing silver ions is selected. The antibacterial layer continuously releases antibacterial ingredients through sustained-release technology to maintain the long-term antibacterial properties of the membrane;

[0110] Barrier layer: Use polyester (PET) material with extremely high gas and water vapor barrier properties to ensure that the film can effectively isolate external bacteria, dust and other pollutants. It is suitable for environments that require high barrier properties such as hospitals and medical device packaging;

[0111] Support layer: Use high-strength polypropylene (PP) material to enhance the membrane's ability to resist external physical damage and ensure the stability of the membrane when used in a medical environment.

[0112] 2. Preparation of antibacterial layer

[0113] Silver ions (Ag + ) as an antibacterial component, the mass fraction of silver ions in the antibacterial layer is 7%, and the silver ions are evenly distributed in the polymer substrate through efficient nano-encapsulation technology;

[0114] Add sustained-release agents (such as ethylcellulose and polylactic acid complex) to ensure the continuous release of antimicrobial ingredients;

[0115] The self-healing polymer material enables the membrane to automatically repair itself when it is damaged by scratches, punctures, etc., thus avoiding damage to the antibacterial properties.

[0116] 3. Preparation of barrier layer

[0117] Made of polyester (PET) material, 50μm thick, with excellent barrier properties;

[0118] The barrier layer is laminated with the antimicrobial layer and the support layer by co-extrusion technology to ensure good adhesion between the three layers of film.

[0119] 4. Preparation of support layer

[0120] Polypropylene (PP) material is used to form a film through a melt extrusion process to ensure that the tensile strength and tear strength of the film are sufficient to withstand the friction and impact in the medical environment;

[0121] The support layer has a thickness of 40 μm and enhances the mechanical strength and durability of the membrane.

[0122] 5. Performance Testing

[0123] Antibacterial effect: Through antibacterial experiments, the membrane can effectively inhibit pathogenic bacteria such as Escherichia coli and drug-resistant Staphylococcus aureus in a medical environment, and the antibacterial effect is maintained for more than 60 days;

[0124] Barrier performance: oxygen permeability is 0.03g / m 2 ·day, water vapor transmission rate is 0.15g / m 2 day, suitable for the strict requirements of barrier properties in the medical and health field;

[0125] Mechanical properties: tensile strength is 90MPa and tear strength is 20N, ensuring the durability and stability of the film in medical packaging.

[0126] Example 3: Household cleaning product packaging

[0127] 1. The antibacterial film is designed for household cleaning product packaging and adopts a multi-layer structure:

[0128] Antibacterial layer: using copper ions (Cu 2+ ) antibacterial material, copper ions have strong antibacterial properties, and sustained antibacterial effects are achieved through sustained release technology;

[0129] Barrier layer: Low-density polyethylene (LDPE) material is used as the barrier layer to ensure that the packaging has a good barrier effect on gas and water vapor and prevent the entry of external pollutants;

[0130] Support layer: Made of polypropylene (PP) material, it provides sufficient structural strength and wear resistance to ensure the stability of the packaging during transportation and storage.

[0131] 2. Preparation of antibacterial layer

[0132] Copper ions are used as antibacterial components, with a copper ion mass fraction of 3%, and the antibacterial effect is enhanced through microparticle coating technology;

[0133] Add a sustained-release agent (such as chitosan complex) to the antibacterial layer to control the release rate of copper ions so that the antibacterial effect is sustained and stable during the packaging process;

[0134] Self-healing polymers ensure that the antibacterial layer can automatically repair itself if it encounters scratches or damage during use, thus preventing the antibacterial effect from weakening.

[0135] 3. Preparation of barrier layer

[0136] Low-density polyethylene (LDPE) is used as the barrier material with a thickness of 40 μm. LDPE has good transparency, low gas permeability and low water vapor permeability, and is suitable for packaging household cleaning products;

[0137] The barrier layer and the antibacterial layer are combined together through a co-extrusion process to ensure the overall performance of the film.

[0138] 4. Preparation of support layer

[0139] The support layer is prepared by melt extrusion process using polypropylene (PP) material with a thickness of 50 μm, providing higher strength and toughness.

[0140] 5. Performance Testing

[0141] Antibacterial effect: Through the bacterial inhibition test, the antibacterial film can effectively inhibit common molds and bacteria, such as Staphylococcus aureus and Escherichia coli, and the antibacterial effect lasts for more than 60 days;

[0142] Barrier performance: oxygen permeability is 0.05g / m 2 ·day, water vapor transmission rate is 0.3g / m 2 day, applicable to packaging requirements for household cleaning products;

[0143] Mechanical properties: tensile strength is 75MPa and tear strength is 12N, ensuring that the film is not easily damaged during transportation and storage.

[0144] Example 4

[0145] Referring to Table 1, the performance of different membrane structures of Examples 1, 2 and 3 is compared, and the data of antibacterial performance, barrier performance and mechanical properties are summarized to provide a selection basis for different application fields, among which:

[0146] Antibacterial layer: silver ions, copper ions, silver ions and other antibacterial ingredients are used respectively, and self-repair technology and slow-release design are adopted in different embodiments;

[0147] Barrier layer: Different materials such as polyethylene, polyester and low-density polyethylene (LDPE) are used to optimize the barrier properties of the film;

[0148] Support layer: Made of polypropylene (PP) material, with enhanced strength and wear resistance.

[0149]

[0150]

[0151] In summary, the present invention solves the problem of the attenuation of the antibacterial effect of the traditional antibacterial film over time by adopting self-healing materials and sustained-release technology. The self-healing polymer can automatically repair when the surface of the film is damaged or scratched to maintain the integrity of the antibacterial layer; the sustained-release agent is designed to control the release rate of the antibacterial component so that it maintains a stable antibacterial effect during long-term use. By accurately designing the multi-layer structure of the film, not only the continuity of the antibacterial effect is guaranteed, but also the excellent barrier performance of the film is ensured. By selecting a high-strength support layer material and adopting an optimized processing technology (such as melt extrusion, hot pressing molding, etc.), the tensile strength, tear resistance and wear resistance of the film are significantly improved, and the peeling or damage of the antibacterial layer caused by the influence of the external environment (such as friction, ultraviolet irradiation, etc.) is avoided, thereby improving the long-term stability and service life of the film. The present invention comprehensively considers the requirements of antibacterial, barrier and mechanical properties, and provides a high-efficiency and multifunctional film material suitable for food packaging, medical and health care, household cleaning and other fields. It solves the problems of attenuation of the antibacterial effect of the antibacterial film in the prior art, decreased barrier performance and easy damage of the film, and has strong market application potential.

[0152] Although the embodiments of the present invention have been shown and described, it is understandable to those skilled in the art that, unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the usual meanings understood by persons with ordinary skills in the field to which the present invention belongs. The words "including" or "comprising" and the like used in the present invention mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. The words "connect" or "connected" and the like are not limited to physical or mechanical connections, but may also include electrical connections, whether direct or indirect. "Up", "down", "left", "right", etc. are only used to indicate relative position relationships. When the absolute position of the described object changes, the relative position relationship may also change accordingly.

[0153] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multilayer film with high antibacterial resistance, characterized in that: The multilayer film with high antibacterial resistance is composed of three layers, namely an antibacterial layer, a barrier layer and a support layer. The antibacterial layer is located at the outermost layer of the film and is made of a material containing antibacterial ingredients. The barrier layer is located below the antibacterial layer and the support layer is located below the barrier layer.

2. A multilayer film with high antibacterial resistance according to claim 1, characterized in that: The antibacterial layer is prepared by the following steps: a. Select antibacterial ingredients, which are metal ions such as silver, copper, zinc, natural plant extracts or their complexes, and can effectively inhibit the growth of bacteria, fungi and other pathogenic microorganisms to ensure the antibacterial effect. The mass fraction of the antibacterial ingredients is 1-10% to ensure the antibacterial effect; b. encapsulating the antibacterial component by a nano-encapsulation technique or a cross-linked polymer encapsulation technique; c. Mixing the encapsulated antibacterial component with a base polymer material (such as polyethylene, polypropylene, etc.) to form a coating material with antibacterial function, wherein the concentration of the coating material is 10-50%; d. uniformly coating the above coating material on the outer surface of the film by a solvent coating method, a blade coating method or a spray coating method, controlling the uniformity and thickness of the coating during the coating process, and the coating thickness is 0.1-10 μm; e. The coated film is subjected to heat treatment or UV curing, the heat treatment temperature is 100-180°C, the treatment time is 10-30 minutes, or the UV curing intensity is 100-200mJ / cm 2 , to further improve the adhesion and stability of the coating, ensuring that the antibacterial layer can be effective for a long time during the use of the membrane.

3. The multilayer film with high antibacterial resistance according to claim 1, characterized in that: The barrier layer is prepared by the following steps: a. Select polymer materials, such as polyester (PET), polypropylene (PP), polyvinyl chloride (PVC), polyamide (PA) or their composite materials, with good gas and vapor barrier properties. The specific selection should be based on the application scenario of the film, and high barrier materials should be given priority. The selective barrier permeability of oxygen, carbon dioxide and water vapor is 0.01-0.5g / m 2 day; b. Forming the barrier material into a film by solution impregnation, coextrusion or hot pressing; C. The prepared barrier layer is combined with the antibacterial layer and the support layer by heat pressing, laminating or bonding. The bonding temperature is controlled at 150-200°C and the pressing pressure is 5-10MPa to ensure the bonding strength between the three layers of materials and avoid delamination or structural instability.

4. The multilayer film with antibacterial high resistance according to claim 1, characterized in that: The supporting layer is prepared by the following steps: a. Select high-strength polymer materials, such as polyethylene (PE), polyester (PET), polypropylene (PP), polyamide (PA) or their composite materials, to ensure that the film has sufficient tensile strength, tear resistance, impact resistance and wear resistance during use, with a tensile strength of 50-150MPa and a tear strength of 10-40N; b. preparing the support layer material into a film by melt extrusion, hot pressing or lamination; c. Combine the support layer with the antibacterial layer and the barrier layer by a process of hot pressing, lamination or bonding. The bonding temperature is controlled at 150-200°C and the pressing pressure is 5-10MPa to ensure that the support layer provides the necessary mechanical strength for the multilayer film to prevent the film from breaking or deforming during use.

5. The multi-layer film with high antibacterial resistance according to claim 1, characterized in that: The thickness of the multilayer film with antibacterial high resistance is 10-200 μm, wherein: The thickness of the antimicrobial layer is 0.1-10 μm, which can provide a long-lasting antimicrobial effect while maintaining the flexibility of the film; The thickness of the barrier layer is 1-100 μm, ensuring that the film has sufficient gas and water vapor barrier properties; The thickness of the support layer is 5-100 μm, which can provide the membrane with the required mechanical strength and ensure the durability of the membrane in practical applications.

6. The multilayer film with high antibacterial resistance according to claim 1, characterized in that: The antibacterial layer is enhanced by a self-repairing material, and the self-repairing material is selected from a polymer material with a self-healing function, which can automatically repair the antibacterial layer during the use of the membrane, so that the antibacterial layer maintains an antibacterial effect for a longer period of time during use.

7. The multi-layer film with high antibacterial resistance according to claim 1, characterized in that: The antibacterial layer is designed with a sustained-release agent to ensure that the release rate of the antibacterial component is stable over a long period of time, avoid the excessive loss of the antibacterial component, and ensure the sustainability of the antibacterial effect.

8. A method for preparing a multilayer film with high antibacterial resistance according to claim 1, characterized in that: The following steps are involved: S1. selecting and preparing an antibacterial component, encapsulating the antibacterial component using a nano-encapsulation technology or a cross-linked polymer encapsulation technology, and controlling the release rate of the antibacterial component; S2. Select a suitable polymer material and prepare a barrier layer material, and prepare the barrier layer by a solution impregnation method, a co-extrusion method or a hot pressing method; S3, selecting a material for the support layer and preparing the support layer by a melt extrusion method, a hot pressing method or a lamination method; S4, arranging the antibacterial layer, the barrier layer and the support layer in a predetermined order by a co-extrusion method, a hot pressing method or a lamination method, and combining them into a shape; S5. Cooling, cutting and winding the prepared multilayer film to obtain a multilayer film with antibacterial effect, excellent barrier properties and high mechanical strength.

9. The method for preparing a multilayer film with antibacterial high resistance according to claim 8, characterized in that: The release rate of the antibacterial component is adjusted by a sustained-release control agent, so that the antibacterial component is continuously released during use, maintaining a long-term and effective antibacterial effect.

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