PVC film containing wormwood essence and preparation method thereof

Abstract

The invention relates to a PVC film containing wormwood essence and a preparation method thereof.The PVC film containing wormwood essence comprises a film material body and microcapsule essence particles dispersed in the film material body, the film material body mainly contains PVC, each microcapsule essence particle comprises a capsule wall and an essence mixture wrapped by the capsule wall, and the microcapsule essence particles are dispersed in the film material body. The essence mixture contains wormwood essence. The PVC film containing the wormwood essence can have antibacterial and insect-repelling effects for a long time (within 68 months), is safe and environment-friendly, and is suitable for the fields of medical packaging, home decoration and agricultural greenhouses.

Description

Technical Field

[0001] The present invention relates to the technical field of thin films, and in particular to a PVC film containing mugwort essence and a preparation method thereof. Background Art

[0002] PVC film is a thin film material made from polyvinyl chloride (PVC) resin. Its excellent physical and chemical properties, such as flexibility, durability, chemical resistance, water resistance, and electrical insulation, have led to its widespread use in industries such as packaging, construction, agriculture, and healthcare. Currently, PVC film can be applied to medical packaging, home decoration, and agricultural greenhouses, where antibacterial and insect repellent properties are often required. Adding antibacterial and insect repellent properties to PVC film would greatly enhance its value.

[0003] In the existing technology, antibacterial and insect repellents for plastics often use chemically synthesized insect repellents. Some of these insect repellents have certain environmental pollution and may be toxic to non-target organisms. There are also technical solutions that use silver nanoparticles or silver ions for antibacterial purposes. However, silver ions are expensive, difficult to recycle, and can cause soil pollution.

[0004] Mugwort is a common plant in the Asteraceae family with medicinal value. Modern research has found that its volatile oils possess antibacterial and antiviral properties, inhibiting a variety of bacteria and viruses, including Bacillus anthracis, Staphylococcus aureus, Escherichia coli, Salmonella typhi, and Shigella dysenteriae. Mugwort's volatile oils also have insect repellent properties, significantly repelling mosquitoes and cockroaches. However, mugwort essential oils are easily volatile, making their long-term antibacterial and insect repellent effects difficult to achieve. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the first purpose of the present invention is to provide a PVC film containing mugwort essence, which can have long-term antibacterial and insect repellent effects (within 68 months), is safe and environmentally friendly, and is suitable for medical packaging, home decoration and agricultural greenhouse fields.

[0006] The second object of the present invention is to provide a method for preparing the PVC film containing wormwood essence.

[0007] To achieve the first purpose of the present invention, the present invention provides a PVC film containing mugwort flavor, comprising a film material body and microcapsule flavor particles dispersed in the film material body, wherein the film material body mainly contains PVC, and the microcapsule flavor particles include a capsule wall and a flavor mixture wrapped by the capsule wall, and the flavor mixture contains mugwort flavor.

[0008] In some embodiments of the present invention, the mugwort essence is a natural essence extracted from mugwort.

[0009] In some embodiments of the present invention, the particle size of the microcapsule flavor particles is 50-200 nm.

[0010] In some embodiments of the present invention, the film body further contains a first plasticizer, and the mass ratio of the first plasticizer to the PVC is (0.8-1.2):100.

[0011] In some embodiments of the present invention, the film body further contains a silane coupling agent, and the mass ratio of the silane coupling agent to the PVC is (0.01-0.05):100.

[0012] In some embodiments of the present invention, the flavor mixture further contains a second plasticizer, which is the same as or different from the first plasticizer.

[0013] In some embodiments of the present invention, the first plasticizer and the second plasticizer are independently selected from at least one of dioctyl terephthalate, dioctyl phthalate, and dibutyl phthalate.

[0014] In some embodiments of the present invention, the mass ratio of the second plasticizer to the mugwort essence is (0.05-0.1):1.

[0015] In some embodiments of the present invention, the silane coupling agent is γ-chloropropyltriethoxysilane.

[0016] In some embodiments of the present invention, the capsule wall is a copolymer of acrylate and chlorine-containing acrylate.

[0017] In some embodiments of the present invention, the acrylate is selected from at least one of ethyl acrylate, propyl acrylate, and butyl acrylate.

[0018] In some embodiments of the present invention, the chlorine-containing acrylate is selected from chloroethyl acrylate.

[0019] In some embodiments of the present invention, the acrylic acid ester is a mixture of ethyl acrylate and butyl acrylate in a mass ratio of 1:(0.5-0.8).

[0020] In some embodiments of the present invention, in the capsule wall, the mass ratio of the acrylate to the chlorine-containing acrylate is 1:(0.1-0.2).

[0021] In some embodiments of the present invention, the mass ratio of the capsule wall to the mugwort essence is 1:(1.5-2).

[0022] In some embodiments of the present invention, the mass ratio of the PVC to the microcapsule fragrance particles is 100:(1-10).

[0023] In some embodiments of the present invention, the thickness of the PVC film containing mugwort essence is 0.08-0.15 mm.

[0024] In some embodiments of the present invention, the light transmittance of the PVC film containing mugwort essence is above 88%.

[0025] To achieve the second object of the present invention, the present invention also provides a method for preparing a PVC film containing wormwood essence according to any of the above schemes, comprising the following steps:

[0026] Step 1: extracting mugwort leaf powder by supercritical extraction or steam distillation to separate and obtain mugwort essence;

[0027] Step 2: Mixing wormwood essence, a second plasticizer, an initiator, and an emulsifier to obtain an oil phase, dispersing the oil phase in an aqueous phase prepared by mixing ethanol and water in a volume ratio of 1:6 to obtain an oil-in-water emulsion, adding acrylate and chlorine-containing acrylate dropwise to the oil-in-water emulsion, stirring and heating to react, filtering, washing, and drying after the reaction to obtain microcapsule essence particles;

[0028] Step 3: Mix the microcapsule flavor particles, PVC, the first plasticizer and the silane coupling agent, extrude them, and calender them into a film.

[0029] In some embodiments of the present invention, in step 1, fresh mugwort leaves are selected, dried at a low temperature of 50°C, and then crushed to 60 mesh; then, essential oil is extracted by steam distillation at 100°C for 3 hours, and then concentrated by molecular distillation to obtain mugwort essence with a purity of ≥95%, or the essential oil is extracted using supercritical CO2.

[0030] In some embodiments of the present invention, in step 2, the emulsifier is at least one of sodium lauryl sulfate and sodium alkyl sulfonate; the initiator is at least one of azobisisobutyronitrile and azobisisoheptanenitrile; and the temperature of the heating reaction is 50-60°C.

[0031] In some embodiments of the present invention, in step three, the extrusion is carried out on a twin-screw extruder, and the processing temperature is controlled in the range of 160-180°C; the calendering is carried out on a four-roll calender, and the temperature of the cooling roller is maintained at 45+2°C.

[0032] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0033] The present invention disperses microencapsulated mugwort essence in a PVC substrate. The microencapsulated essence particles are evenly distributed within the film, forming a sustained-release structure. This allows the finished film to continuously release mugwort active substances for 8-12 months at room temperature. Leveraging the properties of mugwort essence, the PVC film achieves antibacterial and insect repellent properties while being safe and environmentally friendly. This environmentally friendly functional film is suitable for medical packaging, furniture decorative films, toy films, raincoat films, outdoor products, and other fields. DETAILED DESCRIPTION

[0034] The present invention provides a PVC film containing mugwort essence. This PVC film can release mugwort active substances for a long period of time (8-12 months), thereby exerting long-term antibacterial and insect repellent effects. It is suitable for outdoor use, such as agricultural greenhouse film, and is also suitable for use in scenarios with direct or indirect human contact, such as medical packaging and furniture decoration. Of course, the PVC film of this embodiment is also applicable to other fields.

[0035] Specifically, the PVC film of this embodiment includes a film body and microcapsule fragrance particles dispersed in the film body. The microcapsule fragrance particles can be evenly dispersed in the film body.

[0036] The film material mainly contains PVC, that is, PVC is the main component of the film material. For example, PVC accounts for more than 90% of the total mass of the film material, preferably more than 95%, and more preferably more than 98%. PVC has good mechanical strength, corrosion resistance and flame retardancy, and can be used in various packaging, decoration and protective films.

[0037] The microcapsule flavor particles include a capsule wall and a flavor mixture wrapped by the capsule wall. The capsule wall can protect the flavor mixture, achieve a slow release of the flavor, and prevent the flavor from being fully released or oxidized prematurely.

[0038] The flavor mixture contains mugwort flavor, which mainly contains eucalyptol, α-pinene, β-caryophyllene, sabinene, camphor, flavonoids, flavonols, tetracyclic triterpenes and pentacyclic triterpenes, etc. It can be separated from mugwort extract and can play an antibacterial and antiparasitic role.

[0039] It can be seen that this embodiment, by mixing microcapsule flavor particles into the PVC film, enables the PVC film containing mugwort flavor to achieve long-term antibacterial and insect repellent properties, and is environmentally friendly and safe, complying with 32P, ROHS and REACH environmental protection standards.

[0040] In some examples, the mugwort essence is a natural essence extracted from mugwort, which has little pollution to the environment, and its source and subsequent processing are environmentally friendly and safe to humans.

[0041] In some examples, the particle size of the microcapsule fragrance particles is 50-200 nm. When the particle size of the microcapsule fragrance particles is within the above range, they can be evenly dispersed in the PVC film and evenly exert the antibacterial and insect repellent effects.

[0042] In some examples, the film material further comprises a first plasticizer, with the mass ratio of the first plasticizer to PVC being (0.8-1.2):100. The first plasticizer can improve the flexibility, thermal stability, and processing plasticity of the PVC. The amount of the first plasticizer used can be 0.8 parts, 0.9 parts, 1 part, 1.1 parts, 1.2 parts, etc., relative to 100 parts by mass of PVC.

[0043] In some examples, the film also contains a silane coupling agent in a mass ratio of 0.01-0.05 to 100 parts per PVC. This silane coupling agent can further enhance the adhesion between the microcapsule fragrance particles and the film. The amount of silane coupling agent used can be 0.01, 0.02, 0.03, 0.04, 0.05, etc., relative to 100 parts by mass of PVC.

[0044] In some examples, the silane coupling agent is γ-chloropropyltriethoxysilane, which contains siloxane bonds and chlorine atoms and can improve the bonding strength with the polar groups of PVC and microcapsule fragrance particles through intermolecular forces.

[0045] In some examples, the flavor mixture further comprises a second plasticizer, which may be the same as or different from the first plasticizer, but is preferably the same. The second plasticizer can plasticize the capsule wall and the PVC film and diffuse between the capsule wall and the PVC film, thereby regulating the release rate of the flavor active ingredient from the capsule wall.

[0046] In some examples, the first plasticizer and the second plasticizer are independently selected from at least one of dioctyl terephthalate, dioctyl phthalate, and dibutyl phthalate. The raw materials of the above plasticizers are easily available and have good plasticizing effects.

[0047] In some examples, the mass ratio of the second plasticizer to the mugwort essence is (0.05-0.1):1, that is, for 1 part by mass of the mugwort essence, the second plasticizer is 0.05 part, 0.06 part, 0.07 part, 0.08 part, 0.09 part, 0.1 part, etc.

[0048] In some examples, the capsule wall is a copolymer of acrylate and chlorine-containing acrylate. By using the copolymer of chlorine-containing acrylate, the molecular anchoring of the fragrance and the PVC matrix is ​​achieved, the stable bonding is improved, and the microcapsule fragrance particles are prevented from collectively precipitating from the PVC as the temperature rises.

[0049] In some examples, the acrylate is selected from at least one of ethyl acrylate, propyl acrylate, and butyl acrylate. The above acrylate has the characteristics of good reactivity and good protection effect on flavors.

[0050] In some examples, the chlorine-containing acrylate is selected from chloroethyl acrylate, which contains chlorine and has good compatibility with the PVC matrix.

[0051] In some examples, the acrylate is a mixture of ethyl acrylate and butyl acrylate in a mass ratio of 1:(0.5-0.8). Using a mixed acrylate can adjust the toughness of the capsule wall, facilitating the long-term, stable release of the wormwood active ingredient. For every 1 part by mass of ethyl acrylate, the mass of butyl acrylate is 0.5, 0.6, 0.7, 0.8, etc.

[0052] In some examples, the mass ratio of acrylate to chlorine-containing acrylate in the capsule wall is 1:(0.1-0.2), resulting in a moderate chlorine content in the capsule wall, good adhesion between the capsule wall and the PVC substrate, and good toughness of the capsule wall. The mass of chlorine-containing acrylate is 0.1 part, 0.15 part, 0.2 part, etc. per 1 part by mass of acrylate.

[0053] In some examples, the mass ratio of the capsule wall to the mugwort essence is 1:(1.5-2), so that the capsule wall can provide better protection for the essence mixture. For every 1 part by weight of the capsule wall, the mass of the essence mixture can be 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, 2 parts, etc.

[0054] In some examples, the mass ratio of PVC to microcapsule fragrance particles is 100:(1-10), allowing the PVC film to maintain a high essential oil release rate. The mass of the microcapsule fragrance particles is 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, etc., relative to 100 parts by mass of PVC.

[0055] In some examples, the thickness of the PVC film containing mugwort essence is 0.08-0.15 mm, which makes the film have good mechanical properties and meets the application requirements of packaging, agricultural greenhouses, etc.

[0056] In some examples, the light transmittance of the PVC film containing mugwort essence is greater than 85%, preferably greater than 88%. To maintain a high light transmittance, the mass ratio of PVC to microcapsule essence particles is 100:(15).

[0057] In some examples, the method for preparing the PVC film containing mugwort essence includes the following steps:

[0058] Step 1: Extract the mugwort leaf powder by supercritical extraction or steam distillation to separate the mugwort essence. The desired mugwort essence can be obtained by fractionation according to the boiling point of the extraction / extract.

[0059] Step 2: Mix the mugwort essence, a second plasticizer, an initiator, and an emulsifier to form an oil phase. This oil phase is dispersed in an aqueous phase composed of ethanol and water in a volume ratio of 1:6 to form an oil-in-water emulsion. Acrylate and chlorinated acrylate are dropwise added to the oil-in-water emulsion, stirred, and heated for reaction. After the reaction, the particles are filtered, washed, and dried to form microcapsule fragrance particles. Microcapsule fragrance particles with the essence mixture as the core and the acrylate copolymer as the wall are formed by emulsion polymerization. Using ethanol and water in a volume ratio of 1:6 as the aqueous phase allows the acrylate and chlorinated acrylate to be slightly soluble in the aqueous phase, improving their dispersibility and allowing them to diffuse evenly throughout the emulsion. Furthermore, the initiator easily diffuses to the interface between the aqueous and oil phases, allowing the polymerization reaction of the capsule wall to proceed around the essence mixture.

[0060] Step 3: Mix and extrude the microcapsule fragrance particles, PVC, the first plasticizer, and the silane coupling agent, and then calender the mixture into a film. This process ensures that the microcapsule fragrance particles are evenly dispersed in the substrate containing PVC, the first plasticizer, and the silane coupling agent, and forms a formed film. This process complies with the QB / T 4878-2022 industry standard.

[0061] In some examples, in step 1, fresh mugwort leaves are dried at 50°C and then crushed to a 60-mesh size, facilitating the subsequent extraction of the mugwort essence. The essential oil is then extracted by steam distillation at 100°C for 3 hours, followed by molecular distillation and concentration to obtain a mugwort essence with a purity of ≥95%. Alternatively, supercritical CO2 extraction can be used to effectively extract the essential oil.

[0062] In some examples, the emulsifier is at least one of sodium lauryl sulfate and sodium alkyl sulfonate, which is beneficial for improving the dispersion of the oil phase in the water phase.

[0063] In some examples, the initiator is at least one of azobisisobutyronitrile and azobisisoheptanenitrile, and the heating reaction temperature is 50-60° C., which is conducive to polymerization at a lower temperature and avoids volatilization of the flavor.

[0064] In some examples, in step three, extrusion is performed on a twin-screw extruder, with the processing temperature controlled within the range of 160-180°C to prevent thermal decomposition. Calendering is performed on a four-roll calender, with the cooling roll temperature maintained at 45 ± 2°C to minimize flavor volatilization. GC-MS analysis of the resulting product reveals an active ingredient retention rate exceeding 92%.

[0065] The present invention will be further described in detail below through specific examples. In the following examples, the raw materials with the same name have the same substance type and substance source.

[0066] The preparation steps of Examples 1 to 8 are as follows:

[0067] (1) Fresh mugwort leaves were selected, dried at 50°C, and then crushed to 60 mesh. The essential oil was extracted by steam distillation (100°C / 3h), and the flavor components with a purity of about 98% were obtained by molecular distillation and concentration.

[0068] (2) Mixing mugwort essence, plasticizer, initiator azobisisobutyronitrile and emulsifier sodium lauryl sulfate to obtain an oil phase, adding the oil phase dropwise and dispersing it in an aqueous phase prepared by mixing ethanol and water in a volume ratio of 1:6 with high-speed stirring to obtain an oil-in-water emulsion, slowly adding acrylate and chlorine-containing acrylate dropwise to the oil-in-water emulsion, stirring and heating to 60°C for reaction, filtering, washing and drying after the reaction is completed to obtain microcapsule essence particles.

[0069] (3) The microcapsule flavor particles, PVC, plasticizer and silane coupling agent are mixed evenly in a high-speed mixer, extruded by a twin-screw extrusion process at a temperature range of 160-180°C in each section, and calendered into a film by a four-roll calender. The temperature of the cooling roller is maintained at 45+2°C, and the film thickness is 0.15mm.

[0070] The preparation steps of Comparative Example 1 are as follows:

[0071] (1) Fresh mugwort leaves were selected, dried at 50°C, and then crushed to 60 mesh. The essential oil was extracted by steam distillation (100°C / 3h), and the flavor components with a purity of about 98% were obtained by molecular distillation and concentration.

[0072] (2) The flavor component, PVC, plasticizer and silane coupling agent were mixed evenly in a high-speed mixer, extruded by a twin-screw extrusion process at a temperature range of 160-180°C in each section, and calendered into a film by a four-roll calender. The temperature of the cooling roller was maintained at 45+2°C, and the film thickness was 0.15 mm.

[0073] The dosage ratios of the components in the microcapsule flavor particles of Examples 1 to 8 are shown in Table 1 below.

[0074] Table 1 Example microcapsule essence particle component dosage ratio

[0075]

[0076] The usage ratios of the components in the films of Examples 1 to 8 and Comparative Example 1 are shown in Table 2 below.

[0077] Table 2 The proportion of each component in the film

[0078]

[0079] Performance Testing

[0080] The following tests were performed on the PVC films obtained in the above examples and comparative examples.

[0081] (1) Antibacterial effect: The prepared PVC film was tested with Escherichia coli upon production, after being placed outdoors for 4 months, and after being placed outdoors for 8 months, respectively, in accordance with GB / T 21510-2008;

[0082] (2) Insect repellent effect: When the prepared PVC film was made, and after being placed outdoors for 4 months and 8 months, 30 aphids were placed in the center of the film cut into 5 cm*5 cm, with an empty area around the film. After 3 hours, the number of insects remaining on the film was observed.

[0083] (3) Visible light transmittance: When the prepared PVC film is made, it is tested with reference to GB / T 2410-2008.

[0084] (4) Heat resistance stability: Place the film in a water bath for 100 h, then bend and swing the film repeatedly 40 times to observe whether there is any particle precipitation on the film surface.

[0085] The test results are shown in Table 3 below.

[0086] Table 3 Test results

[0087]

[0088] Finally, it should be emphasized that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A PVC film containing wormwood essence, characterized in that It includes a film body and microcapsule flavor particles dispersed in the film body, the film body mainly contains PVC, the microcapsule flavor particles include capsule walls and a flavor mixture wrapped by the capsule walls, and the flavor mixture contains mugwort flavor.

2. The PVC film containing wormwood essence according to claim 1, characterized in that The wormwood essence is a natural essence extracted from wormwood; The particle size of the microcapsule flavor particles is 50-200nm: The film body further contains a first plasticizer, and the mass ratio of the first plasticizer to the PVC is (0.8-1.2):100; The membrane body further contains a silane coupling agent, and the mass ratio of the silane coupling agent to the PVC is (0.01-0.05):

100.

3. The PVC film containing wormwood essence according to claim 2, characterized in that The flavor mixture further comprises a second plasticizer, which is the same as or different from the first plasticizer; The first plasticizer and the second plasticizer are independently selected from at least one of dioctyl terephthalate, dioctyl phthalate, and dibutyl phthalate; The mass ratio of the second plasticizer to the wormwood essence is (0.05-0.1):1; The silane coupling agent is γ-chloropropyltriethoxysilane.

4. A PVC film containing wormwood essence according to any one of claims 1 to 3, characterized in that The capsule wall is a copolymer of acrylate and chlorine-containing acrylate; The acrylate is selected from at least one of ethyl acrylate, propyl acrylate, and butyl acrylate; The chlorine-containing acrylate is selected from chloroethyl acrylate.

5. The PVC film containing wormwood essence according to claim 4, characterized in that The acrylic acid ester is a mixture of ethyl acrylate and butyl acrylate in a mass ratio of 1: (0.50.8); In the capsule wall, the mass ratio of the acrylate to the chlorine-containing acrylate is 1:(0.1-0.2); The mass ratio of the capsule wall to the mugwort essence is 1:(1.5-2).

6. The PVC film containing wormwood essence according to claim 5, characterized in that The mass ratio of the PVC to the microcapsule fragrance particles is 100:(1-10); The thickness of the PVC film containing wormwood essence is 0.08-0.15 mm; The light transmittance of the PVC film containing mugwort essence is above 88%.

7. The method for preparing a PVC film containing wormwood essence according to any one of claims 1 to 6, characterized in that The following steps are involved: Step 1: extracting mugwort leaf powder by supercritical extraction or steam distillation to separate and obtain mugwort essence; Step 2: Mixing wormwood essence, a second plasticizer, an initiator, and an emulsifier to obtain an oil phase, dispersing the oil phase in an aqueous phase prepared by mixing ethanol and water in a volume ratio of 1:6 to obtain an oil-in-water emulsion, adding acrylate and chlorine-containing acrylate dropwise to the oil-in-water emulsion, stirring and heating to react, filtering, washing, and drying after the reaction to obtain microcapsule essence particles; Step 3: Mix the microcapsule flavor particles, PVC, the first plasticizer and the silane coupling agent, extrude them, and calender them into a film.

8. The preparation method according to claim 7, characterized in that In the step 1, fresh mugwort leaves are selected, dried at 50° C., and then crushed into 60 mesh; Then, the essential oil is extracted by steam distillation at 100° C. for 3 hours, and then concentrated by molecular distillation to obtain wormwood essence with a purity of ≥95%, or the essential oil is extracted by supercritical CO2.

9. The preparation method according to claim 7, characterized in that In the step 2, the emulsifier is at least one of sodium lauryl sulfate and sodium alkyl sulfonate; The initiator is at least one of azobisisobutyronitrile and azobisisoheptanenitrile; The temperature of the heating reaction is 50-60°C.

10. The preparation method according to any one of claims 7 to 9, characterized in that In the step three, the extrusion is carried out on a twin-screw extruder, and the processing temperature is controlled within the range of 160-180°C; the calendering is carried out on a four-roll calender, and the temperature of the cooling roller is maintained at 45+2°C.

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