CN104441899B - Meet water sensitivity, the preparation method of high-efficiency antimicrobial laminated film - Google Patents

Abstract

The invention provides a preparation method of a water-sensitive, high-efficiency antibacterial composite film. The present invention adopts natural essential oil as an antibacterial agent, which effectively keeps the antibacterial film safe and non-toxic; through the introduction of the atmosphere type antibacterial effect, the antibacterial efficiency is effectively improved; in order to further improve the antibacterial efficiency, slow-release solid chlorine dioxide is used as an antibacterial agent , Effectively improve the antibacterial efficiency and antibacterial cycle. The multi-layer co-extrusion method is used to prepare the antibacterial film, which fully realizes the various functions of the antibacterial film. It not only blocks the escape of the antibacterial atmosphere to the outside world, but also prolongs the antibacterial cycle. The antibacterial efficiency of chlorine responds to water, effectively regulates the concentration of antibacterial agents, and ensures the antibacterial effect in high humidity environments. According to different types of antibacterial agents, the antibacterial efficiency of the antibacterial film is basically maintained: the antibacterial efficiency against Escherichia coli is 73-100%, and the antibacterial efficiency against Staphylococcus aureus is 86-100%.

Description

Preparation method of water-sensitive, high-efficiency antibacterial composite film

technical field

This application relates to a high-efficiency, water-responsive antimicrobial film.

Background technique

Microorganisms are everywhere, and they multiply quickly. They exist in the air, water, soil, and everything we touch every day. When bacteria contaminate our food, they can easily cause various diseases and even threaten our lives. . For cooked food and fruits and vegetables packaged with ordinary plastic wrap that does not have antibacterial function, due to its rich nutrition and poor air circulation, due to the existence of respiration, it provides a warm environment for bacteria, yeast and actinomycetes. The humid environment leads to the easy production of microorganisms and accelerates the spoilage process of food, which brings huge economic losses to human beings and threatens human health at the same time.

The problem of food storage, especially fruits and vegetables, has become a global problem, which brings huge economic losses to human beings every year. In countries with relatively backward refrigeration equipment, the corruption rate of fruits and vegetables even reaches 40-50%. to reach about 20%. If the antibacterial properties of the antibacterial film can be used to extend the storage period of fruits and vegetables to meet the needs of long-term storage and long-distance transportation, very considerable economic effects can be obtained. The long-standing method is to use sterilizing agents while refrigerating, but chemical sterilizing agents cause great harm to the human body. Inorganic antibacterial agents based on active metals have limited their wide application due to the harm of heavy metals to the human body and their high cost. Therefore, it is urgent to develop a natural, harmless antibacterial agent to prepare antibacterial film, so as to achieve the purpose of antibacterial and fresh-keeping.

Antibacterial agents can be divided into inorganic antibacterial agents, organic antibacterial agents, polymer antibacterial agents and natural antibacterial agents according to their source and composition.

There are two types of inorganic antimicrobial agents. One is to use metal ions such as silver, copper, zinc, etc., loaded on the inorganic carrier, and they all have a bactericidal effect, so as to obtain an inorganic antibacterial agent with antibacterial properties. Minerals that can be used as inorganic carriers include zeolite, phosphate, bentonite, montmorillonite, and silica gel; the other is an inorganic antibacterial agent that utilizes the photocatalytic activity of oxides such as titanium dioxide to achieve antibacterial. Natural ores, shells, etc. also have this property.

The active metal itself and its ions have an inhibitory effect on the biological activity of microorganisms. The principle is that the heavy metals combine with the proteins of microorganisms, and the biological proteins in microorganisms will denature, which will promote the failure of normal metabolism of microorganisms, resulting in the reduction of microbial activity and even death. , so as to achieve the effect of sterilization or antibacterial. When heavy metal inorganic antibacterial agents are added to the antibacterial film, there are two explanations for the antibacterial mechanism. One is the ordinary contact type, which is the same as the antibacterial mechanism when microorganisms directly contact the antibacterial agent, and the other is the active oxygen mechanism. It is believed that the metal ions dispersed in the antibacterial film absorb the surrounding energy and activate the adsorption on the surface of the film. Oxygen ions and free hydroxyl groups are generated from the water and oxygen, and the oxidation-reduction ability of the two effectively plays the role of sterilization or bacteriostasis. Photocatalytically active semiconductor materials are mainly TiO2. Under the irradiation of light, this type of material can also catalyze oxygen and water to generate hydroxyl radicals and active oxygen ions, which react with biologically active substances in microorganisms and affect their normal physiological activities, thereby achieving Purpose.

For inorganic antibacterial agents, a relatively low addition amount can achieve a good antibacterial effect, and it has the characteristics of spectral antibacterial properties, long antibacterial time and high temperature resistance, and is suitable for adding to materials that require higher processing temperatures. However, due to its high production cost, slow antibacterial speed, poor compatibility with resins, unfavorable dispersion, easy discoloration and other reasons, and only contact antibacterial, its wide application is limited.

The mechanism of organic antibacterial agents is that organic molecules combine with anionic groups on the surface of bacterial cell membranes, and then gradually enter the cells to undergo biochemical reactions, or react with groups such as sulfhydryl groups on the surface of bacteria, destroying the physiological system of microorganisms, thereby inhibiting or even killing them. microorganism. There are mainly quaternary ammonium salts, quaternary phosphonium salts, biguanides, organic halides, organic metals, tin compounds and other antibacterial agents, thiabendazole, imidazole anti-mold and anti-algae agents, and thiazoline preservatives and so on. Organic antibacterial agents are easy to use, have good compatibility with plastics, are quick to take effect, and have strong specificity. However, some organic antibacterial agents are carcinogenic to humans and easily denatured, and microorganisms are also prone to drug resistance, and the antibacterial cycle is short. , so there are still big problems in practical applications.

Another class of antibacterial agents is polymer antibacterial agents. The antibacterial principle of polymer antibacterial agents is also similar to other antibacterial agents, which react with microorganisms through their own charges to inhibit their activity. Compared with low-molecular-weight antibacterial agents, high-molecular antibacterial agents have better high temperature resistance, better compatibility with resin matrix, less oozing, and have the advantages of broad-spectrum resistance and long-lasting antibacterial effect. There is the problem of secondary pollution to food. For polymer antibacterial agents, due to the large molecular weight of the polymer, the antibacterial agent is not easy to penetrate the cell wall, its migration speed is relatively slow, and its antibacterial efficiency is low, resulting in poor dispersion on the surface, resulting in a decline in antibacterial effect, while high Molecular antibacterial agents are contact antibacterial, and only when they are in contact can they exert their antibacterial effect.

The main sources of natural antibacterial agents are various Chinese herbal medicines and other natural plants, mainly including castor oil, peppermint, lemon leaf and other extracts, chitosan, sorbic acid, turmeric root alcohol, vanillin, hinokitiol, behenyl, mongolica , Essential oils. Natural antibacterial agents (such as mustard essential oil, garlic essential oil, oregano oil), acid-base substances, aloe vera, pomegranate peel, tea, licorice, houttuynia cordata, Radix Isatidis, etc.; chitosan, chitin, and Insect antibacterial protein, etc.; bile alum, realgar, etc. are extracted from minerals. It mainly enters the cell by breaking the cell wall, and chemically reacts with the metabolites of the bacterial body, destroying its biological activity and affecting its survival and reproduction. Research by Zhang Na and others found that when the concentration of mustard essential oil is only 2 μL in a 1L space, the inhibitory effect on the four pathogenic bacteria can reach 100%. Natural antibacterial agents are not chemical products, they come from natural plants, so they can be used directly.

No matter what kind of antibacterial agent is used, it must meet the basic requirements of high efficiency and non-toxicity. But the main mode of action of antibacterial agents at present is mainly contact antibacterial, therefore, its antibacterial efficiency is on the low side. On the other hand, due to the low antibacterial efficiency, it is necessary to increase the dosage of antibacterial agents, resulting in increased toxic and side effects of antibacterial agents, which seriously affects the normal use function of antibacterial films. Therefore, the development of a highly efficient and non-toxic antibacterial film material has become an urgent need for the development of antibacterial films, and it has an important role in promoting food preservation, fruit and vegetable preservation. Moreover, in many cases, in order to maintain a high antibacterial effect, it is often necessary to add a large amount of antibacterial materials, which increases the difficulty of controlling the cost and side effects of the product. In the actual use process, the growth of many strains is often inseparable from water. Therefore, it is hoped that the development of water-sensitive antibacterial materials will not only effectively reduce product costs, but also effectively adjust the antibacterial effect according to the external humidity. For the development of intelligent antibacterial films Products have important promotional value. Therefore, the present invention fully integrates the above characteristics, and develops a polyethylene antibacterial film material that is safe, non-toxic, high in antibacterial efficiency, and sensitive to water.

Contents of the invention

The purpose of the present invention is to provide a technology that can be used to prepare high-efficiency antibacterial films, which can fully improve the antibacterial efficiency by using the atmosphere antibacterial method, and ensure the safety process of the antibacterial films without polluting food.

Another object of the present invention is to provide a method for preparing a water-sensitive solid antibacterial agent, and effectively realize the sustained release of the solid antibacterial agent.

Technical scheme of the present invention is as follows:

A method for preparing a water-sensitive, high-efficiency antibacterial composite film, comprising the following steps:

1) Melt and blend natural essential oils and polymers with a melting point below 100°C on an extruder according to the mass ratio range of 15-25:70-90, and control the processing temperature below 100°C to prepare high-concentration natural essential oil bases grain;

2) Utilize slow-release agent, sodium hypochlorite and ethanol according to the ratio of mass ratio range 2-15:80-95:5-15 to prepare slow-release solid sodium hypochlorite granules; Prepare slow-release solid citric acid granules with a mass ratio range of 2-18: 90-100: 3-8: 5-15; pass the above two granules through an 80-mesh sieve, and arrange them for later use;

3) The polyethylene resin, calcium carbonate, the slow-release sodium chlorite particles prepared in step 2) and the slow-release citric acid particles are in a weight ratio of 80-95:10-30:0.05-1:0.05-1 Stir evenly and granulate;

4) The polyethylene resin, calcium carbonate, the slow-release sodium chlorite particles prepared in step 2), the slow-release citric acid particles and the natural essential oil masterbatch prepared in step 1) are in a weight ratio of 80-95:10-30 : 0.05-1: 0.05-1: 0.50-2 ratio range Stir evenly and granulate;

5) Utilize film blowing machine or casting machine to prepare high-efficiency antibacterial film, the basic structure is

a) the surface layer is an airtight polymer layer, the middle layer is the solid chlorine dioxide slow-release matrix layer prepared in step 3), and the food contact layer is the natural essential oil matrix layer prepared in step 1); or

b) The surface layer is an airtight polymer layer, the middle layer is the solid chlorine dioxide slow-release matrix layer prepared in step 3), and the food contact layer is the natural essential oil and solid chlorine dioxide matrix layer prepared in step 4).

Wherein, it also includes step 6) after the functional film is produced by a film blowing machine or a casting machine, it is sealed and packaged online. Sealed packaging is preferably made of aluminum foil as the packaging substrate to fully inhibit gas circulation and prolong the storage time of the antibacterial film.

Wherein, the slow-release agent includes at least one of resin materials such as acrylic resin, hydroxypropyl methylcellulose or polyacrylamide.

Wherein, the low melting point polymer includes: at least one of ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, ethylene copolymer or propylene copolymer.

Wherein, the blocking agent includes at least one of citric acid esters, castor oil or paraffin.

Wherein, the sodium hypochlorite is replaced by sodium chlorate, and/or the citric acid is replaced by oxalic acid or acetic acid organic acid.

Wherein, the natural essential oils include lavender essential oil, mugwort oil, clove oil, linoleum oil, oregano oil, tea tree oil, citronella oil, cinnamon oil, eucalyptus oil, artemisia oil, mustard oil, sweet orange oil, etc. at least one of .

The thickness of the surface layer ranges from 2 μm to 5 μm, the thickness of the middle layer ranges from 3 μm to 6 μm, and the thickness of the food contact layer ranges from 2 μm to 5 μm.

6) After the functional film is produced by a film blowing machine or a casting machine, it is required to realize online sealing and packaging.

As can be seen from the above description, the present invention provides a method for preparing a water-sensitive, high-efficiency antibacterial composite film. The main indicators of the antibacterial effect of the antibacterial film prepared by the present invention are as follows:

(1) For different essential oils and proportions, the antibacterial efficiency of Escherichia coli is 73-100%.

(2) For different essential oils and proportions, the antibacterial efficiency of Staphylococcus aureus is 86-100%.

(3) Under normal temperature (25°C) conditions, the antibacterial cycle is maintained at 8-12 days.

(4) When the ambient humidity increases, the release of chlorine dioxide is automatically increased to maintain the antibacterial effect in the sealed system. In a humid environment, when the humidity is 90%, on the basis of keeping the antibacterial efficiency higher than 80%, the antibacterial efficiency is maintained for 4-7 days. The basic mechanical strength index of the polyethylene antibacterial film prepared by the invention: the tensile strength is higher than 10MPa. The fracture productivity is higher than 80%. The right-angle tear strength is higher than 300N/cm.

detailed description

The following examples are just to better illustrate the present invention, but the protection scope of the present invention is not limited thereto.

The preparation of embodiment 1 natural essential oils polyethylene antibacterial film:

Realize the immobilization of natural essential oils in polyethylene films, rely on the volatilization of natural essential oils, and effectively improve the antibacterial efficiency of antibacterial films through the atmosphere-type antibacterial effect; due to the use of natural essential oils as antibacterial agents, their own safety and stability More reliable, and then realized the non-toxic characteristics of the antibacterial film.

The specific implementation steps are as follows:

(1) Preparation of high-concentration natural essential oil masterbatch with natural essential oil and low melting point polymer:

In this example, mustard oil is used as a typical natural essential oil for description:

Mix the antioxidant into 20 kg of mustard oil and stir evenly; add 70 kg of ethylene-vinyl acetate copolymer and 10 kg of ethylene-propylene copolymer into the kneader, and then add the mustard oil into the kneader batch by batch. Knead well until the mustard oil is absorbed into the polymer resin matrix.

(2) Preparation of natural essential oil masterbatch (granule 0): Add the above-prepared resin directly into a single-screw extruder, extrude and granulate below 120°C, and use air cooling as the main cooling method to prepare a concentration of 20% natural essential oil masterbatch.

(3) Preparation of antibacterial polyethylene particles (particle 1): 6.5 kilograms of polyethylene resin, 2 kilograms of calcium carbonate and 1 kilogram of natural essential oil masterbatch (particle 0) were mixed on a high-speed mixer for 10 minutes, and then extruded on a twin-screw On-machine extrusion granulation. The melting temperature is controlled below 140°C, and air cooling is used as the main cooling method.

(4) Preparation of antibacterial film: on a three-layer co-extrusion film blowing machine, prepare a three-layer antibacterial film. The surface layer is set as a polyethylene layer (thickness is 3 μm), which effectively inhibits the outward diffusion of the natural essential oil atmosphere, and the middle layer is an antibacterial polyethylene layer with a low concentration of natural essential oils (thickness is 4 μm, prepared from particle 1 in step 3) , and the food contact layer (thickness is 3 μ m, prepared by the particle 0 of step 2), is the antibacterial polyethylene layer of the natural essential oil of high concentration. During the film blowing process, the stretch ratio is strictly controlled to realize the air permeability of the antibacterial film layer, which is conducive to the volatilization of natural essential oils and forms an antibacterial atmosphere.

(5) Antibacterial effect:

experimental method

Refer to the standard QB/T 2591-2003, ISO 22196, ASTM G21-96 for the experiment, the simple process is as follows:

A. Drop 0.4ml of bacterial liquid on a 50×50mm antibacterial film, because the water and the film are incompatible, and the effect of surface tension makes the bacterial liquid bead-like;

B. Gently cover the 40×40mm ordinary film (ordinary polyethylene material, thickness 10μm) on the bacterial liquid to ensure that the bacterial liquid does not leak from the edge of the film;

C. The bacteria solution is fully immersed between the 50×50mm antibacterial film and the 40×40mm ordinary film, and 0.4ml of the bacteria solution just spreads to the edge of the 40×40mm covering film.

Antibacterial results

Anti-Escherichia coli (Escherichia coli ATCC8739)

Table 1 Antibacterial film inhibits the growth of Escherichia coli (antibacterial time: 40h; experimental model bacteria: Escherichia coli ATCC8739)

Anti-Staphylococcus aureus 6538P

Table 2 - Antibacterial film inhibits the growth of Staphylococcus aureus (antibacterial time: 40h; experimental model bacteria: Staphylococcus aureus 6538P)

The preparation of embodiment 2 natural essential oil/solid chlorine dioxide class polyethylene antibacterial film

(1) Preparation of high-concentration natural essential oil masterbatch with natural essential oil and low melting point polymer:

In this example, mustard oil is used as a typical natural essential oil for description:

Mix the antioxidant into 20 kg of mustard oil and stir evenly; add 70 kg of ethylene-vinyl acetate copolymer and 10 kg of ethylene-propylene copolymer into the kneader, and then add the mustard oil into the kneader batch by batch. Knead well until the mustard oil is absorbed into the polymer resin matrix.

(2) Preparation of natural essential oil masterbatch: Add the above-prepared resin directly into a single-screw extruder, extrude and granulate below 120°C, and use air cooling as the main cooling method to prepare natural essential oil with a concentration of 20%. Essential oil masterbatch (granule 0).

(3) Preparation of slow-release solid chlorine dioxide:

Preparation of slow-release sodium chlorite powder:

Mix 0.5 kg of polyacrylic acid resin III with 5 kg of sodium chlorite, then dissolve 0.025 kg of hydroxypropyl methylcellulose in 500 mL of 70% alcohol to make a slurry, add it to the above mixture, and make a soft material. Granules were prepared through a 20-mesh sieve, and after sufficient drying, the granules were sized using a 20-mesh sieve (granule 3).

Preparation of slow-release citric acid powder:

Mix 0.5 kg of polyacrylic acid resin III, 0.2 kg of triethyl citrate and 3 kg of citric acid, then dissolve 0.025 kg of hydroxypropyl methylcellulose in 500 mL of 70% alcohol to make a slurry, and add it to the above mixture , making soft materials, granulating with a 20-mesh sieve, and after fully drying, sizing (granule 4) with a 20-mesh sieve.

(4) Preparation of solid chlorine dioxide/polyethylene functional particles (particle 5):

6.5 kg of polyethylene resin, 2 kg of calcium carbonate, 0.05 kg of slow-release sodium chlorite particles (particle 3) and 0.05 kg of slow-release citric acid particles (particle 4) were mixed on a high-speed mixer for 10 minutes, and then mixed in a double It is extruded and granulated on a screw extruder, and the melting temperature is controlled below 140°C.

(5) Preparation of natural essential oil-solid chlorine dioxide/polyethylene/functional particles (particle 6):

6.5 kg of polyethylene resin, 2 kg of calcium carbonate, 0.05 kg of slow-release sodium chlorite granules (granule 3), 0.05 kg of slow-release citric acid granules (granule 4) and 0.1 kg of natural essential oil masterbatches (granule 0) Mix on a high-speed mixer for 10 minutes, then extrude and granulate on a twin-screw extruder, and control the melting temperature below 140°C.

(6) Preparation of water-sensitive antibacterial film: a variety of water-sensitive antibacterial materials are prepared by multi-layer co-extrusion through a blown film machine or a casting machine.

(1) the surface layer is a pure polyethylene layer (thickness is 3 μm), and the antibacterial gas is diffused to the outside; the middle layer is a solid chlorine dioxide/polyethylene antibacterial layer (particle 5, a thickness of 4 μm), when the ambient humidity increases, Increase the release of chlorine dioxide and maintain the antibacterial effect in the sealed system; the food contact layer (particle 0, thickness 3μm) is an antibacterial layer of natural essential oil/polyethylene, relying on the volatility of natural essential oil to maintain the antibacterial effect of the system atmosphere. The antibacterial process is safe and non-toxic due to the use of natural essential oils.

(II) The surface layer is a pure polyethylene layer (thickness is 3 μm), which blocks the antibacterial gas from diffusing to the outside; the middle layer is a solid chlorine dioxide/polyethylene antibacterial layer (particle 5, a thickness of 4 μm), when the ambient humidity increases, Increase the release of chlorine dioxide and maintain the antibacterial effect in the sealed system; the layer in contact with food (thickness 3 μm) is natural essential oil-solid chlorine dioxide/polyethylene antibacterial layer (prepared by particle 6), relying on the volatilization of natural essential oil To maintain the antibacterial atmosphere of the system. And further increase the antibacterial effect of solid chlorine dioxide, improve antibacterial efficiency, and are suitable for antibacterial films used in high humidity environments.

(6) Antibacterial effect:

experimental method

Refer to the standard QB/T 2591-2003, ISO 22196, ASTM G21-96 for the experiment, the simple process is as follows:

A. Drop 0.4ml of bacterial liquid on the antibacterial film (I or II) with a size of 50×50mm. Because the water and the film material are incompatible, the effect of surface tension makes the bacterial liquid bead-like;

B. Gently cover the 40×40mm ordinary film (ordinary polyethylene material, thickness 10μm) on the bacterial liquid to ensure that the bacterial liquid does not leak from the edge of the film;

C. The bacteria solution is fully immersed between the 50×50mm antibacterial film and the 40×40mm ordinary film, and 0.4ml of the bacteria solution just spreads to the edge of the 40×40mm covering film.

Antibacterial Results

Anti-Escherichia coli (Escherichia coli ATCC8739)

Table 3 Antibacterial film I inhibits the growth of Escherichia coli (antibacterial time: 40h; experimental model bacteria: Escherichia coli ATCC8739)

Anti-Staphylococcus aureus 6538P

Table 4 Antibacterial film I inhibits the growth of Staphylococcus aureus (antibacterial time: 40h; experimental model bacteria: Staphylococcus aureus 6538P)

Table 5 Effect of time on antibacterial film I inhibiting the growth of Staphylococcus aureus (antibacterial temperature: 35°C; humidity: 30% experimental model bacteria: Staphylococcus aureus 6538P)

Table 6 Effects of humidity and time on antibacterial film I inhibiting the growth of Staphylococcus aureus (antibacterial temperature: 35°C; humidity: 90%; model bacteria for experiment: Staphylococcus aureus 6538P)

Compared with Example 1, the antibacterial effect of Example 2 is stronger. Especially in a humid environment, the antibacterial ability of Example 1 will decrease, while Example 2 can still maintain a high antibacterial efficiency in a humid environment.

The above embodiment discloses a preparation method and use of a water-sensitive antibacterial polyethylene film, but the protection scope of the present invention is not limited thereto.

Claims (8)

1. The preparation method of water-sensitive, high-efficiency antibacterial composite film comprises the following steps: 1) Melt and blend natural essential oils and polymers with a melting point below 100°C on an extruder according to the mass ratio range of 15-25:70-90, and control the processing temperature below 100°C to prepare high-concentration natural essential oil bases grain; 2) Utilize slow-release agent, sodium hypochlorite and ethanol according to the ratio of mass ratio range 2-15:80-95:5-15 to prepare slow-release solid sodium hypochlorite granules; Prepare slow-release solid citric acid granules with a mass ratio range of 2-18: 90-100: 3-8: 5-15; pass the above two granules through an 80-mesh sieve, and arrange them for later use; 3) Stir the polyethylene resin, calcium carbonate, slow-release sodium hypochlorite granules and slow-release citric acid granules prepared in step 2) evenly in a ratio range of 80-95:10-30:0.05-1:0.05-1 by weight , granulation; 4) The polyethylene resin, calcium carbonate, the slow-release sodium hypochlorite particles prepared in step 2), the slow-release citric acid particles and the natural essential oil masterbatch prepared in step 1) are in a weight ratio of 80-95: 10-30: 0.05- The ratio range of 1:0.05-1:0.50-2 is stirred evenly and granulated; 5) Utilize film blowing machine or casting machine to prepare high-efficiency antibacterial film, the basic structure is a) the surface layer is an airtight polymer layer, the middle layer is the solid chlorine dioxide slow-release matrix layer prepared in step 3), and the food contact layer is the natural essential oil matrix layer prepared in step 1); or b) The surface layer is an airtight polymer layer, the middle layer is the solid chlorine dioxide slow-release matrix layer prepared in step 3), and the food contact layer is the natural essential oil and solid chlorine dioxide matrix layer prepared in step 4). 2. according to the preparation method of water-sensitive, high-efficiency antibacterial composite film described in claim 1, it is characterized in that: also comprise step 6) after functional film is produced by film blowing machine or casting machine, on-line sealing and packaging. 3. according to the preparation method of water sensitivity described in claim 1 or 2, high-efficiency antibacterial composite film, it is characterized in that: described slow-release agent comprises acrylic resin, hydroxypropyl methylcellulose or polyacrylamide at least one of . 4. According to claim 1 or 2, the preparation method of the water-sensitive, high-efficiency antibacterial composite film is characterized in that: the polymer whose melting point is lower than 100°C includes: ethylene-vinyl acetate copolymer, ethyl At least one of propylene copolymer, ethylene copolymer or propylene copolymer. 5. According to the preparation method of the water-sensitive, high-efficiency antibacterial composite film described in claim 1 or 2, it is characterized in that: the blocker includes at least one of citric acid esters, castor oil or paraffin. 6. according to the preparation method of water sensitivity described in claim 1 or 2, highly efficient antibacterial composite film, it is characterized in that: described sodium hypochlorite replaces with sodium chlorate, and/or citric acid adopts oxalic acid or acetic acid organic acid to replace . 7. According to the preparation method of the water-sensitive, high-efficiency antibacterial composite film described in claim 1 or 2, it is characterized in that: said natural essential oil comprises lavender essential oil. 8. according to claim 1 or 2 described in the preparation method of water-sensitive, high-efficiency antibacterial composite film, it is characterized in that: step 5) the thickness range of surface layer is 2 μ m-5 μ m, and the middle layer thickness range is 3 μ m-6 μ m , The thickness range of the food contact layer is 2μm-5μm.