CN112143076B

CN112143076B - Visible antibacterial breathable antifogging film and preparation method thereof

Info

Publication number: CN112143076B
Application number: CN202011019425.9A
Authority: CN
Inventors: 柳金亭; 蒋维; 邓德强; 王斐
Original assignee: Zhejiang Dahui New Material Co ltd
Current assignee: Zhejiang Dahui New Material Co ltd
Priority date: 2020-09-24
Filing date: 2020-09-24
Publication date: 2023-02-21
Anticipated expiration: 2040-09-24
Also published as: CN112143076A

Abstract

The application relates to the technical field of packaging films, in particular to a visible antibacterial breathable antifogging film and a preparation method thereof, and the visible antibacterial breathable antifogging film comprises a visible film and an antibacterial breathable antifogging film, and is prepared from the following raw materials in parts by weight: 80-90 parts of breathable master batch, 5-10 parts of antibacterial master batch and 5-10 parts of antifogging master batch; the product has the advantages that consumers can visually see the contents, and the product has various performances of antibiosis, fresh preservation, antifogging and air conditioning. The preparation method comprises the following steps: weighing and blending the breathable master batch, the antibacterial master batch and the antifogging master batch according to the proportion; extruding, wherein the temperature of a feeding section and a homogenizing section is 170-220 ℃, and the temperature of a die head is 200-230 ℃; casting, wherein the temperature of a cooling roller is 25-30 ℃; stretching, wherein the stretching multiplying power of the film is 1.05-1.30; and (4) performing heat setting, wherein the heat setting temperature of the film after stretching is 80 ℃, and obtaining a target product. The method has the advantages of simple operation and convenient industrial production.

Description

Visible antibacterial breathable antifogging film and preparation method thereof

Technical Field

The application relates to the technical field of packaging films, in particular to a visible antibacterial breathable antifogging film and a preparation method thereof.

Background

The packaged antifogging and antibacterial agent plays an important role in the quality of modern food, particularly fresh food. Most of fresh foods have the characteristics of perishability, seasonality and regionality, and the fresh foods are easy to decay and deteriorate due to the fact that postpartum storage and fresh-keeping technologies lag relatively. In addition, the fresh food has high moisture content, and the traditional packaging material generates water vapor due to the external environment temperature change or the respiration of the fruits and vegetables, so that the inner surface of the package is fogged, the food quality is influenced, and the food is more easily rotten and deteriorated. Therefore, the antifog and antibacterial packaging material for fresh food becomes a key point of attention of the agricultural product processing industry, food production enterprises, logistics transportation industry and wide consumers at present.

The existing guarantee film usually adds antifogging agent and antibacterial agent into the packaging film (generally PE film), and can obtain modified active packaging film with antifogging and antibacterial effects, and its main performance is to improve the appearance quality of the packaged product, and can inhibit the proliferation of microorganisms on the surface of the food while maintaining the ambient humidity in the package, thereby achieving the purpose of keeping fresh and prolonging the shelf life of the food.

In the prior art, polyethylene is used as a film substrate, antifogging agents and antibacterial agents are added to improve the antifogging and antibacterial properties of the film, the antifogging and antibacterial agents are used for fresh-keeping packages which are easy to rot during storage, and the antibacterial and fresh-keeping capabilities of the fresh-keeping packages are observed. And reasonably adding the antibacterial master batch and the antifogging master batch under the condition of keeping the film to have the most excellent antifogging and antibacterial properties.

The prior art can achieve the effects of antibiosis and antifogging, but still cannot meet higher preservation requirements in the aspects of oxygen permeation and moisture permeation, and usually carries out subsequent opening treatment on a packaging bag; alternatively, the inorganic filler is added to the raw material, but the addition of the inorganic filler to the raw material and the stretching process have a problem that the moisture permeability is increased and the transparency of the film is lowered.

Disclosure of Invention

In order to solve the problems of moisture permeability increase and film transparency decrease in the prior art, the first object of the present application is to provide a visible antibacterial breathable anti-fog film, which has anti-fog and antibacterial effects and is transparent in appearance, and consumers can visually see the contents.

The second purpose of the application is to provide a preparation method of the visible antibacterial breathable antifogging film, the preparation operation of the process is simple, and mass production can be carried out.

The first application purpose of the application is realized by the following technical scheme: the utility model provides a visual antibiotic ventilative antifog film, includes visual membrane and antibiotic ventilative antifog film, and antibiotic ventilative antifog film is made by the raw materials that contain following parts by weight: 80-90 parts of breathable master batch, 5-10 parts of antibacterial master batch and 5-10 parts of antifogging master batch.

By adopting the technical scheme, the film with antifogging and antibacterial effects and high moisture permeability can be obtained, and the proliferation of microorganisms on the surface of food can be inhibited while the environmental humidity in the package is maintained, so that the freshness can be kept and the quality guarantee period of the food can be prolonged; and the appearance is transparent, and the consumer can directly see the contents.

Preferably, the antifogging master batch is prepared from the following raw materials: low density polyethylene, triglycerol monostearate, polyethylene wax emulsion.

By adopting the technical scheme, the hydrophilic group in the triglycerol monostearate adsorbs water molecules in the air and reduces the surface tension of the water molecules, so that the contact angle between the water molecules and the surface of the transparent object is reduced, the water molecules can be wetted and diffused on the surface of the transparent object before forming fine water drops on the surface of the transparent object to form an ultrathin transparent water film, the incident light rays are not scattered, and the interference on the sight line is avoided, so that the antifogging effect is realized, and the triglycerol monostearate is combined with the low-density polyethylene and positioned in the produced film, so that the relatively long antifogging effect can be realized; the polyethylene wax emulsion has a good dispersing effect, so that the triglycerol monostearate can be uniformly dispersed to support the high-quality triglycerol monostearate, and the film obtained by adding the polyethylene wax emulsion has better performances of scratch resistance, water resistance, adhesion resistance, stain resistance, wear resistance and softness.

Preferably, the antifogging master batch comprises 60 to 30 to 10 percent of low-density polyethylene, triglycerol monostearate and polyethylene wax emulsion based on the total weight of the breathable master batch.

By adopting the technical scheme, a better anti-fog effect can be achieved.

Preferably, the antibacterial master batch is prepared from the following raw materials: low-density polyethylene, sodium dehydroacetate and calcium propionate.

By adopting the technical scheme, the sodium dehydroacetate can be well dispersed in the antibacterial master batch taking the low-density polyethylene as the main body, has stronger bacteriostatic action on saccharomycetes, putrefying bacteria and mould in food, and can play a better role in sterilization; the calcium propionate can play a better antibacterial role under an acidic condition, so that the invention has a wider application range.

Preferably, the weight ratio of the low-density polyethylene, the sodium dehydroacetate and the calcium propionate in the antibacterial master batch is 60% to 30% to 10%.

Through adopting above-mentioned technical scheme, can play better antibiotic effect.

Preferably, the breathable master batch is prepared from the following raw materials: main materials and inorganic filler; the main material and the inorganic filler account for 40-60% of the total weight of the breathable master batch; the main materials include low density polyethylene, linear low density polyethylene and metallocene linear low density polyethylene.

By adopting the technical scheme, the inorganic filler mainly generates tiny open pores in the film stretching process, so that the oxygen permeability and the moisture permeability of the film are ensured; the metallocene linear low-density polyethylene plays a role in reducing the overall weight of the film and reducing the requirements on storage cost and operation capital; the toughness of the produced film is improved to some extent, the influence of the transparency reduction of the whole film caused by the addition of the filler can be reduced, the transparency of the whole film can be improved to a certain extent, the hot adhesiveness and the heat sealing temperature are improved, the odor emitted by the film can be reduced, and the film is more environment-friendly.

Preferably, the blending mass ratio of the low-density polyethylene, the linear low-density polyethylene and the metallocene linear low-density polyethylene in the main material is 20.

By adopting the technical scheme, better oxygen permeation and moisture permeation performances can be achieved.

Preferably, the inorganic filler is calcium carbonate, or calcium oxide, or barium sulfate, or titanium dioxide, with an average particle size <5 microns; the surface of the inorganic filler is subjected to irradiation and surface modification treatment by a low-molecular silane coupling agent.

The irradiation and low molecular silane coupling agent surface modification treatment on the surface of the inorganic filler is to mix the inorganic filler, the low density polyethylene, the linear low density polyethylene and the metallocene linear low density polyethylene more uniformly, ensure that the surface of the prepared film has a porous structure and smaller pore diameter in the stretching process and improve the oxygen permeation and moisture permeation performance of the film, wherein the average particle diameter of the calcium carbonate or 4A molecular sieve powder or barium sulfate or titanium dioxide is less than 5 micrometers.

In order to achieve the second object, the invention provides the following technical scheme: a preparation method of a visible antibacterial breathable antifogging film comprises the following steps:

step one, weighing and blending a breathable master batch, an antibacterial master batch and an antifogging master batch according to a ratio;

step two, extruding, wherein the temperature of a feeding section and a homogenizing section is 170-220 ℃, the temperature of a die head is 200-230 ℃, and a film distributor is used as an extrusion die;

step three, casting, wherein the temperature of a cooling roller is 30-60 ℃;

step four, stretching, wherein the stretching multiplying power of the film is 1.05-1.30;

and step five, performing heat setting, wherein the heat setting temperature of the film after stretching is 65-80 ℃, and obtaining the target product.

By adopting the technical scheme, the preparation operation is simpler, and mass production can be carried out.

Preferably, the film distributor comprises a mould main body, and a first material inlet and a second material inlet are formed in one side surface of the mould main body in a pouring mode; a plurality of first material outlets are formed in the opposite side faces of the first material inlet of the die main body in a pouring mode; the first material outlet is arranged along the length direction of the die main body and communicated with the first material inlet; a plurality of second material outlets are formed in the opposite side surface of the first material inlet of the die main body in a pouring mode; the second material outlet is arranged along the length direction of the die main body and is communicated with the second material inlet; the second material outlet is positioned between the adjacent first material inlets.

By adopting the technical scheme, 2 screws can be used for extrusion, wherein the screw A uses a mixture containing antifogging master batch, antibacterial master batch and breathable master batch, the screw B uses transparent polyethylene granules, the screw A extrusion material enters the first material inlet, the screw B extrusion material enters the second material inlet, the materials are extruded in parallel from the first material outlet and the second material outlet, finally, the extruded film is a film which is longitudinally transparent and semitransparent at intervals, and a user can still see contents in the bag through the transparent part after bag making and has an anti-counterfeiting effect.

In summary, the present application has the following advantages:

1. the product has the antifogging and antibacterial effects, can inhibit the proliferation of microorganisms on the surface of food while maintaining the ambient humidity in a package, thereby achieving the aims of keeping fresh and prolonging the quality guarantee period of the food; and the appearance is transparent, and the consumer can directly see the contents.

2. The preparation method has the advantages of simple preparation operation, mass production and easy realization of industrial production.

Drawings

Fig. 1 is a schematic view of the overall structure in the present application.

Fig. 2 isbase:Sub>A cross-sectional view atbase:Sub>A-base:Sub>A in fig. 1.

Fig. 3 is a cross-sectional view at B-B in fig. 1.

Fig. 4 is a schematic view of the connection structure of the mold body and the lead-out member in the present application.

In the figure, 1, a mold body; 10. a film dispenser; 2. a first material inlet; 20. a first material outlet; 3. a second material inlet; 30. a second material outlet; 4. a first material storage cavity; 41. a first connecting channel; 42. a second communicating channel; 5. a second material storage cavity; 51. a third communicating channel; 52. a fourth communicating channel; 6. a lead-out member; 60. a fitting groove; 601. an insert block; 602. a first connection hole; 603. a bolt; 604. a second connection hole; 61. and a collection through groove.

Detailed Description

The present application will be described in further detail with reference to examples.

Raw materials

Device

Referring to fig. 1, a film distributor 10 includes a rectangular mold body 1, wherein a first material inlet 2 and a second material inlet 3 are formed on one side surface of the mold body 1 in a pouring manner; the first material inlet 2 and the second material inlet 3 are spaced from each other, and the direction of a plane where the central axis of the first material inlet 2 and the central axis of the second material inlet 3 are located is consistent with the length direction of the die body 1.

Referring to fig. 1, ten first material outlets 20 are formed on opposite sides of the first material inlet 2 of the mold body 1 by casting; the first material outlet 20 is arranged along the length direction of the mould main body 1 and is communicated with the first material inlet 2; the direction of the plane where the central axes of the ten first material outlets 20 are located is the same as the length direction of the die main body 1. Ten second material outlets 30 are formed in the opposite side surface of the first material inlet 2 of the mould main body 1 in a pouring mode; the second material outlet 30 is arranged along the length direction of the die main body 1 and is communicated with the second material inlet 3; the direction of a plane where the central axes of the ten second material outlets 30 are located is consistent with the length direction of the die main body 1; the second material outlet 30 is located between adjacent first material inlets 2.

Referring to fig. 1, the direction of a plane where the central axes of the ten second material outlets 30 and the central axes of the ten first material outlets 20 are located is the same as the length direction of the mold body 1; the connecting line of the circle center of the first material outlet 20 and the circle center of the second material outlet 30 is a straight line; the linear distance between the circle center of the first material outlet 20 and the circle center of the second material outlet 30 is 1.8mm.

Referring to fig. 1 and 2, a first material storage cavity 4 is formed in the mold body 1 in a pouring mode; the first material storage cavity 4 is cylindrical, and the central axis direction of the first material storage cavity 4 is consistent with the length direction of the die main body 1; the mould main body 1 is cast to form a first connecting channel 41 and ten second connecting channels 42 with the cross sections in a coat hanger shape; the first communicating channel 41 is communicated with the first material storage cavity 4; the single second communication passage 42 communicates with the single first material outlet 20; the central axes of the second communicating channel 42 and the first material outlet 20 are in the same plane; the central axis of the first material storage cavity 4 is perpendicular to a plane formed by the second communication passage 42 and the central axis of the first material outlet 20.

Referring to fig. 1 and 3, the mold body 1 is cast with a second material storage cavity 5; the second material storage cavity 5 is cylindrical, and the direction of the central axis is consistent with the length direction of the die main body 1; a plurality of third communicating channels 51 and a plurality of fourth communicating channels 52 with clothes hanger-shaped cross sections are formed in the mould main body 1 in a pouring mode; the third communicating channel 51 communicates with the second material storage cavity 5; the single fourth communication channel 52 communicates with the single second material outlet 30. The central axes of the fourth communicating channel 52 and the second material outlet 30 are in the same plane; the central axis of the second material storage cavity 5 is perpendicular to the plane formed by the fourth communication channel 52 and the central axis of the second material outlet 30. The diameter of the first communicating passage 41 is equal to the diameter of the third communicating passage 51; the diameter of the first connecting channel 41 is 6.4mm.

Referring to fig. 4, the mold body 1 is detachably connected with the lead-out member 6, and two side walls of the bottom of the mold body 1 are provided with fitting grooves 60; the upper surface of the leading-out piece 6 is welded with an insert 601; a first connection hole 602 is formed in the fitting groove 60; the insert 601 is provided with a second connecting hole 604; the diameters of the first connection hole 602 and the second connection hole 604 are the same, and the central axes of the two holes coincide; the lead-out member 6 is fixedly attached to the mold main body 1 by bolts 603, and the bolts 603 are threadedly attached to the first attachment holes 602 and the second attachment holes 604.

Referring to fig. 4, the lead-out member 6 is provided with a collection through groove 61 penetrating through the upper and lower surfaces of the lead-out member 6; the geometric shape of the collecting through groove 61 is a quadrangular frustum pyramid, the bottom surface and the top surface of the quadrangular frustum pyramid are both rectangular, the length of the bottom surface is 8mm longer than that of the top surface, and the side surfaces of the quadrangular frustum pyramid are all isosceles trapezoids. One end of the bottom surface of the collecting through groove 61 is communicated with the first material outlet 20 and the second material outlet 30 of the mold body 1, that is, the vertical projections of the first material outlet 20 and the second material outlet 30 are in contact with the bottom surface of the quadrangular frustum. During the use, be convenient for A extruded material and B extruded material collect the fusion, form the tensile curtain coating membrane material in complete area, can promote the quality of the assurance membrane of production.

Preparation example

Preparation example 1

Surface treatment of inorganic filler:

1. performing ion implantation on calcium carbonate with the model number of JKGX-A1 by using an ion implanter, wherein the acceleration voltage is 50Kv, and the accelerated ion beam passes through a magnetic analyzer of the ion implanter, and ions selected from the ion beam by the magnetic analyzer bombard a calcium carbonate target surface; and mixing the calcium carbonate obtained by the operation with a Silquest A-187 silane coupling agent for surface modification to obtain the modified calcium carbonate.

2.4A molecular sieve is ball-milled to screen 4A molecular sieve powder with the particle size of 4 mu m, an ion implanter is adopted to carry out ion implantation on the 4A molecular sieve powder, the acceleration voltage is 50Kv, the accelerated ion beam passes through a magnetic analyzer of the ion implanter, and the ions selected from the ion beam by the magnetic analyzer bombard the target surface of the 4A molecular sieve powder; and mixing the 4A molecular sieve powder obtained by the operation with a Silquest A-187 silane coupling agent for surface modification to obtain the modified 4A molecular sieve powder.

3. Carrying out ion implantation on the nanometer titanium dioxide of the model number JKGX-A1 by adopting an ion implanter, wherein the acceleration voltage is 50Kv, and the accelerated ion beam passes through a magnetic analyzer of the ion implanter, and the magnetic analyzer bombards a nanometer titanium dioxide target surface by ions selected from the ion beam; and mixing the nano titanium dioxide obtained by the operation with a Silquest A-187 silane coupling agent for surface modification to obtain the modified nano titanium dioxide.

Preparation example 2

Preparing an antifogging master batch: mixing the linear low-density polyethylene, the triglycerol monostearate and the qualified Bass polyethylene wax emulsion in the weight percentage of 60 to 30 to 10, extruding at 204 ℃, and granulating.

Preparation example 3

Preparing an antibacterial master batch: mixing linear low density polyethylene, sodium dehydroacetate and calcium propionate in 60 wt% to 30 wt% to 10 wt%, extruding at 205 deg.c and pelletizing.

Preparation example 4

Preparing a breathable master batch: mixing the main materials, blending the low-density polyethylene, the linear low-density polyethylene and the metallocene linear low-density polyethylene according to the mass ratio of 20 to 50 to 30 percent, and blending the mixture with the modified calcium carbonate in the preparation example 1, wherein the mass percentage of the main materials to the modified calcium carbonate is 60 percent: 40 percent, extruding at the temperature of 202 ℃, and granulating to obtain the breathable master batch A.

Preparation example 5

Preparing a breathable master batch: mixing the main materials, namely mixing the low-density polyethylene, the linear low-density polyethylene and the metallocene linear low-density polyethylene according to the mass ratio of 20 to 50 to 30 percent, and then mixing the mixture with the modified barium sulfate in the preparation example 1, wherein the mass percentage of the main materials and the modified 4A molecular sieve powder is 60 percent: 40 percent, extruding at the temperature of 204 ℃ and granulating to obtain the breathable master batch B.

Preparation example 6

Preparing a breathable master batch: firstly, mixing main materials, namely mixing low-density polyethylene, linear low-density polyethylene and metallocene linear low-density polyethylene according to the mass ratio of 20 to 50 to 30 percent, and then mixing the mixture with the modified nano titanium dioxide in the preparation example 1, wherein the mass percentage of the main materials and the nano titanium dioxide is 60 percent: 40 percent, extruding at the temperature of 205 ℃ and granulating to obtain the breathable master batch C.

Examples

Example 1:

the visible antibacterial breathable antifogging film comprises a visible film and an antibacterial breathable antifogging film, wherein the visible film is prepared from polyethylene; the antibacterial breathable antifogging film is prepared from 90 parts of breathable master batch A, 5 parts of antibacterial master batch and 5 parts of antifogging master batch.

A preparation method of a visible antibacterial breathable anti-fog film comprises the following steps:

step one, blending 9kg of breathable master batch A, 0.5kg of antibacterial master batch and 0.5kg of antifogging master batch by using balance;

step two, adding 9kg of the air-permeable master batch A, 0.5kg of the antibacterial master batch and 0.5kg of the antifogging master batch extruded in the step one into a cast film extruder, setting the temperature of a feeding section to be 170 ℃, dividing a homogenizing section into seven zones, setting the temperatures of the seven zones to be 190 ℃, 195 ℃, 200 ℃, 205 ℃, 210 ℃, 215 ℃ and 215 ℃, respectively, extruding at the internal plasticizing temperature of 190.2 ℃ and the die head temperature of 215 ℃, using a film distributor 10 as an extrusion die, allowing a first material inlet 2 of the film distributor 10 to flow into polyethylene pellet extrusion materials, and allowing a second material inlet 3 of the film distributor 10 to flow into the mixed extrusion materials in the step 1;

step three, tape casting is carried out, and the temperature of a cooling roller is controlled to be 30 ℃;

step four, adjusting the stretching ratio of the cast film extruder to 1.1, and stretching to form a film;

and step five, after the film is stretched, carrying out heat setting at the temperature of 80 ℃ to obtain a target product.

Example 2:

the visible antibacterial breathable antifogging film comprises a visible film and an antibacterial breathable antifogging film, wherein the visible film is prepared from polyethylene; the antibacterial breathable antifogging film is prepared from 80 parts of breathable master batch A, 5 parts of antibacterial master batch and 5 parts of antifogging master batch.

A preparation method of a visible antibacterial breathable antifogging film comprises the following steps:

step one, blending 8kg of breathable master batch A, 0.5kg of antibacterial master batch and 0.5kg of antifogging master batch by using a balance;

step two, adding the breathable master batch A extruded in the step one, the antibacterial master batch 0.5kg and the antifogging master batch 0.5kg into a cast film extruder, setting the temperature of a feeding section to be 170 ℃, dividing a homogenizing section into seven zones, setting the temperatures of the seven zones to be 190 ℃, 195 ℃, 200 ℃, 205 ℃, 210 ℃, 215 ℃ and 215 ℃, respectively, extruding at the internal plasticizing temperature of 190.3 ℃ and the die head temperature of 215 ℃, using a film distributor 10 as an extrusion die, allowing a first material inlet 2 of the film distributor 10 to flow into polyethylene pellet extrusion materials, and allowing a second material inlet 3 of the film distributor 10 to flow into the mixed extrusion materials in the step 1;

step four, adjusting the stretching ratio of the casting film extruder to be 3, and stretching to form a film;

and step five, after the film is stretched, performing heat setting at the temperature of 80 ℃ to obtain a target product.

Example 3:

the visible antibacterial breathable antifogging film comprises a visible film and an antibacterial breathable antifogging film, wherein the visible film is prepared from polyethylene; the antibacterial breathable antifogging film is prepared from 85 parts of breathable master batch A, 5 parts of antibacterial master batch and 5 parts of antifogging master batch.

step one, blending 8.5kg of breathable master batch A, 0.5kg of breathable master batch A and 0.5kg of antifogging master batch by using a balance;

step two, adding the air-permeable master batch A extruded in the step one, the antibacterial master batch extruded in the step 0.5kg and the antifogging master batch extruded in the step 0.5kg into a casting film extruder, setting the temperature of a feeding section to be 170 ℃, dividing a homogenizing section into seven zones, setting the temperatures of the seven zones to be 190 ℃, 195 ℃, 200 ℃, 205 ℃, 210 ℃, 215 ℃ and 215 ℃, respectively, setting the internal plasticizing temperature to be 191 ℃ and setting the temperature of a die head to be 215 ℃, extruding by using a film distributor 10 as an extrusion die, enabling a first material inlet 2 of the film distributor 10 to flow into polyethylene granule extruded materials, and enabling a second material inlet 3 of the film distributor 10 to flow into mixed extruded materials in the step 1;

Example 4:

the visible antibacterial breathable antifogging film comprises a visible film and an antibacterial breathable antifogging film, wherein the visible film is prepared from polyethylene; the antibacterial breathable antifogging film is prepared from 85 parts of breathable master batch A, 7 parts of antibacterial master batch and 8 parts of antifogging master batch.

step one, blending 8.5kg of breathable master batch A, 0.8kg of antibacterial master batch and 0.7kg of antifogging master batch by using a balance;

step two, adding the air-permeable master batch A extruded in the step one, the antibacterial master batch 0.8kg and the antifogging master batch 0.7kg into a casting film extruder, setting the temperature of a feeding section to be 170 ℃, dividing a homogenizing section into seven zones, setting the temperatures of the seven zones to be 190 ℃, 195 ℃, 200 ℃, 205 ℃, 210 ℃, 215 ℃ and 215 ℃, respectively, setting the internal plasticizing temperature to be 190.6 ℃, extruding at the die head temperature of 215 ℃, using a film distributor 10 as an extrusion die, enabling a first material inlet 2 of the film distributor 10 to flow into the polyethylene pellet extrusion material, and enabling a second material inlet 3 of the film distributor 10 to flow into the mixed extrusion material in the step 1;

step four, adjusting the stretching ratio of a casting film extruder to be 1.1, and stretching to form a film;

Example 5

Example 5 differs from example 1 in that: the breathable master batch A is replaced by breathable master batch B.

Example 6

Example 6 differs from example 2 in that: the breathable master batch A is replaced by a breathable master batch B.

Example 7

Example 7 differs from example 3 in that: the breathable master batch A is replaced by breathable master batch B.

Example 8

Example 8 differs from example 4 in that: the breathable master batch A is replaced by breathable master batch B.

Example 9

Example 9 differs from example 1 in that: the breathable master batch A is replaced by breathable master batch C.

Example 10

Example 10 differs from example 2 in that: the breathable master batch A is replaced by breathable master batch C.

Example 11

Example 11 differs from example 3 in that: the breathable master batch A is replaced by breathable master batch C.

Example 12

Example 12 differs from example 4 in that: the breathable master batch A is replaced by breathable master batch C.

Comparative example

Comparative example 1

A visual antibacterial breathable antifogging film is prepared from 0.5 part of DFM antifogging agent, 1 part of B110N silver antibacterial powder and 80 parts of breathable master batches.

step one, blending 8.0kg of breathable master batch A, 0.8kg of antibacterial master batch and 0.7kg of antifogging master batch by using balance;

step two, adding the material blended in the step one into a casting film extruder, setting the temperature of a feeding section to be 170 ℃, dividing a homogenizing section into seven zones, setting the temperatures of the seven zones to be 190 ℃, 195 ℃, 200 ℃, 205 ℃, 210 ℃, 215 ℃ and 215 ℃, setting the internal plasticizing temperature to be 190.5 ℃, extruding at the die head temperature of 215 ℃, using a film distributor 10 as an extrusion die, enabling a first material inlet 2 of the film distributor 10 to flow into the polyethylene pellet extrusion material, and enabling a second material inlet 3 of the film distributor 10 to flow into the mixed extrusion material in the step 1; step three, tape casting is carried out, wherein the temperature of a cooling roller is 30 ℃;

Comparative example 2

Comparative example 2 differs from comparative example 1 in that: the breathable master batch A is replaced by a breathable master batch B.

Comparative example 3

Comparative example 3 differs from comparative example 1 in that: the breathable master batch A is replaced by breathable master batch C.

Comparative example 4

Comparative example 4 differs from example 1 in that: the antibacterial master batch and the antifogging master batch are not added.

Performance test

The following tests were carried out with the antibacterial breathable antifogging film portion in the films of examples 1 to 12 as test samples 1 to 12, the films of comparative examples 1 to 2 as comparative samples 1 to 2, and the breathable film portion in comparative example 3 as comparative sample 3:

1. and (3) antibacterial testing: testing according to QB/T2591-2003 'antibacterial plastic-antibacterial performance sample method and antibacterial effect'; the antibacterial rate is calculated by the formula of R (%) = (B-C)/BX 100; in the formula, R represents antibacterial rate (%); b average recovery bacteria count (cfu/patch) of a blank control sample; c-average number of recovered bacteria (cfu/piece) of antimicrobial plastic sample.

2. Antifogging test: the test is carried out according to GB/T31726-2015 method for testing antifogging property of plastic films.

3. Water vapor transmission coefficient test: the test is carried out according to GB/T1037-1988 Standard test method for Water vapor permeability of Plastic films and sheets.

4. Oxygen transmission rate test: GB/T19789-005 test on the antibacterial breathable antifogging film by packaging material permeability test plastic film and sheet oxygen coulometer detection method.

5. And (3) transparency test: and testing the light transmittance of the antibacterial breathable antifogging film according to the determination standard of the light transmittance and haze of the GB/T2410-2008 transparent plastic.

FIG. 1 is a graph showing the antibacterial performance parameters of test samples 1 to 12 and comparative examples 1 to 4

Table 2 shows the water vapor transmission coefficient, oxygen transmission rate, antifogging property, transparency parameter of the test samples 1 to 12 and the comparative examples 1 to 4

As can be seen by combining examples 1-12 and comparative examples 1-4 with Table 1, the antimicrobial properties of the films prepared in examples 1-12 were all greater than 99% and were superior to those of comparative examples 1-4. Compared with examples 1-4, the antibacterial property of the film prepared in example 4 is better; by contrast between examples 5-8, the films prepared in example 8 have better antimicrobial properties; in contrast to examples 9-12, the antibacterial property of the film prepared in example 12 was better, and therefore, the antibacterial breathable antifogging film was better antibacterial property of the film prepared from 85 parts of breathable master batch, 7 parts of antibacterial master batch and 8 parts of antifogging master batch.

As can be seen by combining examples 1-12 with comparative examples 1-4 and by combining Table 2, the moisture and oxygen permeability of the films prepared in examples 1-12 are superior to the moisture and oxygen permeability of the films prepared in comparative examples 1-4; the antifogging properties and light transmission of the films prepared in examples 1-12 were superior to those of the films prepared in comparative examples 1-4.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.

Claims

1. A visual antibacterial breathable antifogging film is characterized in that: the antibacterial breathable antifogging film is prepared from the following raw materials in parts by weight:

80 to 90 portions of breathable master batch,

5 to 10 portions of antibacterial master batch,

5-10 parts of antifogging master batch;

the antifogging master batch is prepared from the following raw materials: low density polyethylene, triglycerol monostearate, polyethylene wax emulsion;

the antifogging master batch comprises 60% of medium-low density polyethylene, 30% of triglycerol monostearate and 10% of polyethylene wax emulsion, wherein the percentage of the medium-low density polyethylene, the triglycerol monostearate and the polyethylene wax emulsion accounts for the total weight of the breathable master batch;

the antibacterial master batch is prepared from the following raw materials: low density polyethylene, sodium dehydroacetate, calcium propionate;

the weight ratio of the low-density polyethylene, the sodium dehydroacetate and the calcium propionate in the antibacterial master batch is 60 percent to 30 percent to 10 percent;

the breathable master batch is prepared from the following raw materials: main materials and inorganic fillers;

the main material and the inorganic filler account for 40-60% of the total weight of the breathable master batch;

the main materials comprise low density polyethylene, linear low density polyethylene and metallocene linear low density polyethylene;

the blending mass ratio of the low-density polyethylene, the linear low-density polyethylene and the metallocene linear low-density polyethylene in the main material is 20:50: 30;

the inorganic filler is calcium carbonate, or 4A molecular sieve powder, or barium sulfate, or titanium dioxide, and the average particle size is less than 5 micrometers;

the surface of the inorganic filler is subjected to irradiation and surface modification treatment by a low-molecular silane coupling agent;

the preparation process of the visible antibacterial breathable antifogging film comprises the following steps:

step two, extruding, wherein the temperature of a feeding section and a homogenizing section is 170-220 ℃, the temperature of a die head is 200-230 ℃, and a film distributor (10) is used as an extruding die;

step three, casting, wherein the temperature of a cooling roller is 30-60 ℃;

step five, performing heat setting, wherein the heat setting temperature of the film after stretching is 65-80 ℃ to obtain a target product;

the film distributor (10) comprises a mould main body (1), and a first material inlet (2) and a second material inlet (3) are formed in one side surface of the mould main body (1) in a pouring mode; a plurality of first material outlets (20) are formed on the opposite side surfaces of the first material inlet (2) of the die main body (1) in a pouring way; the first material outlet (20) is arranged along the length direction of the die main body (1) and is communicated with the first material inlet (2); a plurality of second material outlets (30) are formed on the opposite side surfaces of the first material inlet (2) of the mould main body (1) in a pouring mode; the second material outlet (30) is arranged along the length direction of the die main body (1) and is communicated with the second material inlet (3); the second material outlet (30) is located between adjacent first material inlets (2).