An easy-to-tear packaging film and a method for manufacturing the same

Abstract

The application provides an easy-to-tear packaging film and a preparation method thereof. The easy-to-tear packaging film comprises a heat-sealing layer, a barrier layer and a printing layer. The heat-sealing layer comprises polypropylene and color masterbatch. The barrier layer at least partially covers the heat-sealing layer and comprises polypropylene and silicon oxide. The printing layer at least partially covers the barrier layer and comprises polypropylene, maleic anhydride graft copolymerized polypropylene, peroxide and filler. The easy-to-tear packaging film has good easy-to-tear property and barrier property, is easy to recycle, can resist high-temperature cooking and has no performance influence after cooking, and is applicable in various fields.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of packaging materials, and particularly relates to an easy-to-tear packaging film and a preparation method thereof. BACKGROUND

[0002] A facial mask is a kind of skin care product, and its main functions are water supplement, moisture retention and whitening. It covers the keratin layer of the skin to provide moisture for the keratin layer, so as to fully hydrate the keratin layer and improve the appearance and elasticity of the skin. Some facial masks on the market need high-temperature sterilization, and the facial masks need to be kept away from light and moisture, so the light-shielding and water-blocking requirements of the packaging are relatively high. Therefore, the packaging generally selects a sterilization structure containing an aluminum foil. However, the facial mask bag with the aluminum foil structure is not easy to recycle, which does not meet the sustainable development requirement of the packaging. Therefore, it is urgent to provide an easy-to-recycle packaging material without the aluminum foil. SUMMARY

[0003] The present application aims to solve at least one of the above technical problems.

[0004] To this end, the first object of the present application is to provide an easy-to-tear packaging film.

[0005] The second object of the present application is to provide a preparation method of the easy-to-tear packaging film.

[0006] To achieve the first object of the present application, the present application provides an easy-to-tear packaging film, which comprises a heat-sealing layer, a barrier layer and a printing layer. The heat-sealing layer comprises polypropylene and color masterbatch. The barrier layer at least partially covers the heat-sealing layer, and the barrier layer comprises polypropylene and silicon oxide. The printing layer at least partially covers the barrier layer, and the printing layer comprises polypropylene, maleic anhydride graft copolymerized polypropylene, peroxide and filler.

[0007] Compared with the prior art, the technical effects achieved by the technical scheme are as follows: the easy-to-tear packaging film comprises a heat-sealing layer, a barrier layer and a printing layer, the heat-sealing layer comprises polypropylene color masterbatch, polypropylene is widely used due to its advantages of high barrier property, heat resistance, wide application field and low cost, and is an ideal heat-sealing layer material, the color masterbatch is added to the polypropylene to adjust the color of the heat-sealing layer, which not only provides the easy-to-tear packaging film with light resistance to prevent the product in the packaging film from discoloring under light, but also ensures firm heat sealing and improves the efficiency of the packaging bag made of the easy-to-tear packaging film under the premise of ensuring the flatness of the easy-to-tear packaging film; the barrier layer comprises polypropylene and silicon oxide, the silicon oxide further improves the barrier property of the polypropylene, and effectively prolongs the storage period of the product in the packaging film; the printing layer comprises polypropylene, maleic anhydride grafted copolymerized polypropylene, peroxide and filler, the polypropylene can ensure the stability and adhesion of the ink in the printing process, and the easy-to-tear packaging film has a good appearance, and the maleic anhydride grafted copolymerized polypropylene, peroxide and filler can improve the easy-to-tear property of the printing layer; the easy-to-tear packaging film has good easy-to-tear property and barrier property, is easy to recycle, can resist high-temperature cooking and has no performance affected after cooking, and is applicable in various fields.

[0008] In addition, the technical scheme provided by the present application can also have the following technical features:

[0009] In the above technical features, the thickness of the heat-sealing layer is 65-100 microns; and / or the thickness of the barrier layer is 15-30 microns; and / or the thickness of the printing layer is 15-30 microns.

[0010] Compared with the prior art, the technical effects achieved by the technical scheme are as follows: the use of the heat-sealing layer, the barrier layer and the printing layer with the above thicknesses can make the thickness of the easy-to-tear packaging film appropriate, and the easy-to-tear packaging film still has good heat-sealing performance, barrier performance and other performances.

[0011] In any of the above technical features, the water vapor transmission rate of the easy-to-tear packaging film is less than 1 g / (m 2 , 24hrs); and / or the transverse heat shrinkage rate of the easy-to-tear packaging film is less than or equal to 1%; and / or the longitudinal heat shrinkage rate of the easy-to-tear packaging film is less than or equal to 1%.

[0012] Compared with the prior art, the technical effects achieved by the technical scheme are as follows: the water vapor transmission rate of the easy-to-tear packaging film is less than 0.5 g / (m 2 , 24hrs), indicating that the easy-to-tear packaging film has good barrier performance and can effectively prolong the storage period of the product in the packaging film; the transverse heat shrinkage rate and the longitudinal heat shrinkage rate of the easy-to-tear packaging film are both less than or equal to 1%, indicating that the easy-to-tear packaging film is not easy to deform under heat and can be applied in various fields.

[0013] To achieve the second object of the present application, the present application further provides a preparation method of the easy-to-tear packaging film, for preparing the easy-to-tear packaging film of any one of the above technical features, comprising:

[0014] S100, respectively preparing a heat-sealing layer, a barrier layer and a printing layer;

[0015] S200, sequentially stacking from inside to outside in the order of the heat-sealing layer, the barrier layer and the printing layer to obtain the easy-to-tear packaging film;

[0016] Wherein, the heat-sealing layer and the barrier layer, and the barrier layer and the printing layer are fixed by an adhesive; the preparation method of the barrier layer comprises:

[0017] S111, melting and extruding polypropylene to unidirectionally stretch into a polypropylene film;

[0018] S112, after coating an adhesion coating on the polypropylene film, using a silicon target material to sequentially perform evaporation treatment and annealing treatment on the polypropylene film to obtain a polypropylene film with a silicon oxide layer;

[0019] S113, after coating a protective coating on the polypropylene film with the silicon oxide layer, performing drying treatment to obtain the barrier layer.

[0020] Compared with the prior art, the technical effects achieved by the technical solution are as follows: the heat-sealing layer, the barrier layer and the printing layer are respectively prepared, and the layers are combined together by the adhesive, which is firm and not easy to fall off; the barrier layer is attached with a silicon oxide layer on the polypropylene film by evaporation to further improve the barrier property of the polypropylene film; coating an adhesion coating on the polypropylene film before evaporation treatment can increase the adhesion amount of the silicon oxide on the surface of the polypropylene film during the evaporation treatment, and coating a protective coating after the evaporation treatment can further improve the barrier property of the barrier layer and make the barrier layer resistant to high-temperature cooking.

[0021] In any one of the above technical features, the adhesive is a polyurethane adhesive; and / or the dry weight of the adhesive is 4.0 g / m 2 -4.5 g / m 2 ; and / or the thickness of the adhesive is 1-3 μm.

[0022] Compared with the prior art, the technical effects achieved by the technical solution are as follows: using the above types of adhesive and the dry weight and thickness of the adhesive can make the combination of the layers more firm and not easy to fall off, and make the prepared easy-to-tear packaging film have a wider application field and be able to be used as a packaging film material for cosmetics.

[0023] In any of the technical features above, in S112, the adhesion coating is a tungsten hexoxide coating; and / or in S112, the silicon-containing target material is at least one of silicon monoxide and silicon dioxide; and / or in S113, the protective coating is a modified polyvinyl alcohol coating.

[0024] Compared with the prior art, the technical effects achieved by adopting the technical solution are as follows: the adhesion coating adopts the above-mentioned type, which not only can increase the adhesion of silicon oxide, but also has a certain help for improving the mechanical properties of the barrier layer; the silicon-containing target material adopts the above-mentioned type, which can further improve the effect of the evaporation treatment; and the protective coating adopts the above-mentioned type, which can increase the barrier property and is more environmentally friendly.

[0025] In any of the technical features above, in S112, the thickness of the adhesion coating is 1-3 microns; and / or in S112, the thickness of the silicon oxide layer of the polypropylene film with the silicon oxide layer is 1.5-5 microns; and / or in S112, the temperature of the annealing treatment is 55-75 degrees Celsius; and / or in S113, the thickness of the protective coating is 1-3 microns; and / or in S113, the temperature of the drying treatment is 45-65 degrees Celsius.

[0026] Compared with the prior art, the technical effects achieved by adopting the technical solution are as follows: the adhesion coating with the above-mentioned thickness can better improve the adhesion effect of the silicon oxide; the silicon oxide layer and the protective coating with the above-mentioned thickness can give the barrier layer better barrier property, so that the water vapor transmission rate of the prepared easy-to-tear packaging film is lower; and the annealing treatment and the drying treatment with the above-mentioned temperature can promote the barrier layer after the evaporation treatment to have better barrier property.

[0027] In any of the technical features above, the preparation method of the printing layer comprises:

[0028] S121, preparing a printing layer raw material, heating and melting the printing layer raw material to obtain a molten mixture;

[0029] S122, bidirectionally stretching the molten mixture after extrusion to obtain a printing layer;

[0030] The printing layer raw material comprises polypropylene particles, maleic anhydride grafted copolymerized polypropylene particles, peroxide and filler.

[0031] Compared with the prior art, the technical effects achieved by adopting the technical solution are as follows: the printing layer prepared by using the above-mentioned raw materials and method can uniformly disperse the force during tearing, so that the prepared printing layer has easy-to-tear property.

[0032] In any of the technical features above, the mass ratio of the polypropylene particles, the maleic anhydride graft copolymerized polypropylene particles, the peroxide and the filler is 1:(0.4-0.6):(0.01-0.1):(0.01-0.1); and / or the particle size of the filler is 0.01-0.1 microns.

[0033] Compared with the prior art, the technical effects achieved by the technical scheme are as follows: the raw material ratio of the above mass ratio is appropriate, so that the print layer has better tearability; the filler with the above particle size can form a fine dispersed phase in the print layer, further improving the tearability.

[0034] In any of the technical features above, the print layer raw material further comprises an additive; the additive comprises at least one of a plasticizer, a toughening agent and a heat-resistant modifier; and / or the mass ratio of the additive to the polypropylene particles is (0.01-0.1):1.

[0035] Compared with the prior art, the technical effects achieved by the technical scheme are as follows: the addition of the additive of the above kind and mass ratio during the preparation of the print layer can further improve the tearability of the print layer, so that the finally prepared easy-to-tear packaging film is easy to tear linearly.

[0036] After the technical scheme of the present application is adopted, the following technical effects can be achieved:

[0037] 1. The easy-to-tear packaging film of the present application has good tearability and barrier property, is easy to recycle, can withstand high-temperature cooking and has no performance affected after cooking, and is applicable in various fields;

[0038] 2. The barrier layer comprises polypropylene and silicon oxide, the silicon oxide further improves the barrier property of the polypropylene, and can effectively prolong the storage period of the product in the packaging film;

[0039] 3. A layer of adhesion coating is coated on the polypropylene film before the evaporation treatment, which can increase the adhesion amount of the silicon oxide on the surface of the polypropylene film during the evaporation treatment, and the coating of the protective coating after the evaporation treatment can further improve the barrier property of the barrier layer, so that the barrier layer can withstand high-temperature cooking;

[0040] 4. The print layer comprises polypropylene particles, maleic anhydride graft copolymerized polypropylene particles, peroxide and filler, which can make the print layer uniformly disperse the force during tearing, so that the prepared print layer has easy-to-tear property. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the drawings to be used in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0042] Figure 1 A schematic diagram of a tearable packaging film according to an embodiment of the present application;

[0043] Legend: 100 - heat-seal layer; 200 - barrier layer; 300 - printing layer. DETAILED DESCRIPTION

[0044] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0045] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments.

[0046] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the following will be described in conjunction with Figure 1 The specific embodiments of the present application will be described in detail.

[0047] In the related art, in order to meet the needs of high-temperature sterilization and light and water blocking of products such as masks, packaging materials containing aluminum foil are usually used; however, mask bags with aluminum foil structure are not easy to recycle and regenerate, which does not meet the requirements of sustainable development of packaging.

[0048] Therefore, the present application provides a tearable packaging film without aluminum foil, which forms a layer of silicon oxide on the surface of the barrier layer, so that the barrier layer can improve the barrier property and resist high-temperature sterilization, and the performance after sterilization does not change.

[0049] Specifically, as shown in Figure 1 The embodiment of the present application provides a tearable packaging film, which comprises a heat-seal layer 100, a barrier layer 200 and a printing layer 300. The heat-seal layer 100 comprises polypropylene and color masterbatch. The barrier layer 200 is at least partially covered on the heat-seal layer 100, and the barrier layer 200 comprises polypropylene and silicon oxide. The printing layer 300 is at least partially covered on the barrier layer 200, and the printing layer 300 comprises polypropylene, maleic anhydride grafted copolymerized polypropylene, peroxide and filler.

[0050] Preferably, the easy-to-tear packaging film of the present application comprises three layers of heat-sealing layer 100, barrier layer 200 and printing layer 300, the heat-sealing layer 100 comprises polypropylene color masterbatch, polypropylene is widely used due to its high barrier property, heat resistance, wide application field and low cost, etc., and is an ideal raw material of heat-sealing layer 100, the color masterbatch can be added to polypropylene to adjust the color of the heat-sealing layer 100, the color masterbatch is preferably white, and the heat-sealing layer 100 is preferably milky white, which not only provides light shielding property for the easy-to-tear packaging film to prevent the product in the packaging film from discoloring under light, but also enables the heat-sealing layer 100 to be heat-sealed at low temperature, the initial heat-sealing temperature of the heat-sealing layer 100 is 140℃, the heat-sealing strength can be greater than or equal to 40N / 15mm, which ensures the firmness of heat-sealing under the premise of ensuring the flatness of the easy-to-tear packaging film, and improves the efficiency of the packaging bag made of the easy-to-tear packaging film.

[0051] Preferably, the barrier layer 200 comprises polypropylene and silicon oxide, the silicon oxide forms a layer of silicon oxide on the surface of polypropylene, further improving the barrier property of polypropylene, which can effectively prolong the storage period of the product in the packaging film; the printing layer 300 comprises polypropylene, maleic anhydride grafted copolymerized polypropylene, peroxide and filler, the polypropylene can ensure the stability and adhesion of ink during printing, which makes the easy-to-tear packaging film have a good appearance, and the maleic anhydride grafted copolymerized polypropylene, peroxide and filler can improve the easy-to-tear property of the printing layer 300; the easy-to-tear packaging film of the present application has good easy-to-tear property and barrier property, is easy to recycle, can withstand high-temperature cooking and has no performance affected after cooking, and can be applied in various fields.

[0052] Further, the thickness of the heat-sealing layer 100 is 65μm-100μm; and / or the thickness of the barrier layer 200 is 15μm-30μm; and / or the thickness of the printing layer 300 is 15μm-30μm, which can make the thickness of the easy-to-tear packaging film appropriate, and the easy-to-tear packaging film still has good heat-sealing performance, barrier performance and other performances.

[0053] Preferably, the water vapor transmission rate of the easy-to-tear packaging film is less than 0.5g / (m 2 , 24hrs), which indicates that the easy-to-tear packaging film of the present application has good barrier property, and the water vapor transmission rate of the easy-to-tear packaging film is less than 1g / (m 2 , 24hrs) after being cooked at 110℃-130℃ for 20min-45min, and the transverse heat shrinkage rate of the easy-to-tear packaging film is less than or equal to 1%, and / or the longitudinal heat shrinkage rate of the easy-to-tear packaging film is less than or equal to 1%, which indicates that the easy-to-tear packaging film of the present application is not easy to deform under heat, and can be applied in various fields, especially suitable for use as a mask packaging bag, which not only meets the needs of some masks for cooking sterilization, but also ensures long-term moisturizing of the masks.

[0054] In some embodiments of the present application, a method for preparing the easy-to-tear packaging film is also provided, which is used for preparing the easy-to-tear packaging film with any of the above technical features, and comprises:

[0055] S100, respectively preparing a heat-sealing layer, a barrier layer and a printing layer;

[0056] S200, sequentially stacking the heat-sealing layer, the barrier layer and the printing layer from inside to outside to obtain the easy-to-tear packaging film;

[0057] In the method, the heat-sealing layer and the barrier layer, and the barrier layer and the printing layer are fixed by an adhesive; and the method for preparing the barrier layer comprises:

[0058] S111, melting and extruding polypropylene to unidirectionally stretch into a polypropylene film;

[0059] S112, after coating an adhesion coating on the polypropylene film, performing evaporation deposition treatment and annealing treatment on the polypropylene film by using a silicon target material to obtain a polypropylene film with a silicon oxide layer;

[0060] S113, after coating a protective coating on the polypropylene film with the silicon oxide layer, performing drying treatment to obtain the barrier layer.

[0061] Preferably, the heat-sealing layer is a cast polypropylene film added with white masterbatch; the melted polypropylene flows out through a slit of a casting head and is quickly introduced to a cooling roller; in this process, the melted polypropylene is quickly cooled and solidified into a film by contacting the cooling roller.

[0062] Preferably, the heat-sealing layer, the barrier layer and the printing layer are respectively prepared, and the layers are combined together by the adhesive, which is firm and not easy to be separated; when the barrier layer and the printing layer are combined, the adhesive is coated on the surface of the barrier layer with the silicon oxide layer, the combining speed is 70±20 m / min, the oven temperature is 60-80℃, and the combined layers are dried at 50℃ for 12 hours; when the heat-sealing layer and the barrier layer are combined, the combining speed is 70±20 m / min, the oven temperature is 60-80℃, and the combined layers are dried at 50℃ for 120 hours; the barrier layer is attached with a silicon oxide layer on the polypropylene film by evaporation deposition to further improve the barrier property of the polypropylene film; an adhesion coating is coated on the polypropylene film before evaporation deposition to increase the adhesion amount of the silicon oxide on the surface of the polypropylene film during evaporation deposition; a protective coating is coated after evaporation deposition to further improve the barrier property of the barrier layer and make the barrier layer resistant to high-temperature cooking; the polypropylene film is heated to 135-150℃ before evaporation deposition; and in the evaporation deposition process, the target material is evaporated and deposited on the polypropylene film by high-energy electron beam irradiation.

[0063] Preferably, the adhesive is a polyurethane adhesive; and / or the dry weight of the adhesive is 4.0 g / m2 -4.5g / m 2 ; and / or the adhesive thickness is 1-3 microns; the composite between the layers can be more firm and not easy to come off, preferably the dry composite method is used to make the layers composite together, the production efficiency of the dry composite method is high, and the prepared easy-to-tear packaging film has better corrosion resistance, so that the prepared easy-to-tear packaging film can be applied in a wider field and can be used as a packaging film material for cosmetics such as facial masks.

[0064] Preferably, in S112, the adhesion-increasing coating is a tungsten hexoxide coating, which can not only increase the adhesion of silicon oxide but also help improve the mechanical properties of the barrier layer; in S112, the silicon-containing target material is at least one of silicon monoxide and silicon dioxide, which can further improve the effect of the evaporation treatment; in S113, the protective coating is a modified polyvinyl alcohol coating, preferably the carboxylated trehalose is used to modify the polyvinyl alcohol, which can not only increase the barrier property and stability of the barrier layer but also be more green and environmentally friendly.

[0065] Further, in S112, the thickness of the adhesion-increasing coating is 1-3 microns, which can better improve the adhesion effect of silicon oxide; in S112, the thickness of the silicon oxide layer of the polypropylene film with a silicon oxide layer is 1.5-5 microns, which can give the barrier layer better barrier property and make the water vapor transmission rate of the prepared easy-to-tear packaging film lower; in S112, the annealing treatment temperature is 55-75℃, which can improve the corrosion resistance of the barrier layer and remove residual stress, making the barrier layer smoother; in S113, the thickness of the protective coating is 1-3 microns, which can further improve the barrier property of the barrier layer; in S113, the drying treatment temperature is 45-65℃, and the drying treatment preferably uses constant temperature drying, and the drying treatment time is selected according to the actual situation and is not specifically limited here.

[0066] Preferably, the preparation method of the printing layer comprises:

[0067] S121, preparing a printing layer raw material, heating and melting the printing layer raw material to obtain a molten mixture;

[0068] S122, bidirectionally stretching the molten mixture after extrusion to obtain a printing layer;

[0069] Preferably, the printing layer raw material comprises polypropylene particles, maleic anhydride grafted copolymerized polypropylene particles, peroxide and filler.

[0070] Preferably, the mass ratio of the polypropylene particles, the maleic anhydride grafted copolymerized polypropylene particles, the peroxide and the filler is 1:(0.4-0.6):(0.01-0.1):(0.01-0.1); and / or the particle size of the filler is 0.01-0.1 microns.

[0071] Further, the printing layer raw material further comprises an additive; the additive comprises at least one of a plasticizer, a toughening agent, and a heat resistance modifier; and / or the mass ratio of the additive to the polypropylene particles is (0.01-0.1) : 1.

[0072] Preferably, in the preparation of the printing layer, appropriate amounts of maleic anhydride grafted copolymerized polypropylene particles, peroxide, and filler are added, and appropriate additives are selected, so that the tearability of the printing layer and the interfacial adhesion are improved, the compatibility of the components is improved, the force during tearing is uniformly dispersed, a fine dispersed phase is formed in the printing layer, and the easy-tearability of the printing layer is enhanced.

[0073] Preferably, the peroxide is preferably at least one of 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxonane and di-(hexadecyl) peroxydicarbonate, the filler is preferably at least one of talc and diatomite, the plasticizer is preferably a low-molecular-weight polyester such as vegetable oil, and the toughening agent is preferably styrene-butadiene, and the heat resistance modifier is preferably a substituted maleic amide heat resistance modifier.

[0074] Preferably, the printing layer further needs to be subjected to corona treatment before printing, so as to improve the bonding strength of the printing layer and the ink; the printing should be performed before the printing layer and the barrier layer are compounded; the printing speed is 150±20 m / min, the oven temperature is 50-70℃, and the ink is located between the printing layer and the barrier layer after the printing is dried at 40℃ for 24 hours, so that the easy-tear packaging film has a better appearance.

[0075] Embodiment 1

[0076] The embodiment provides an easy-tear packaging bag, which comprises, from inside to outside, a heat-sealing layer, a barrier layer, and a printing layer; the heat-sealing layer is a milky white cast polypropylene film with a thickness of 65 μm; the barrier layer is a uniaxially stretched polypropylene film with a thickness of 15 μm; the printing layer is a biaxially stretched polypropylene film with a thickness of 15 μm; and the preparation method of the easy-tear film comprises the following steps.

[0077] S100, the heat-sealing layer, the barrier layer, and the printing layer are respectively prepared;

[0078] S200, the heat-sealing layer, the barrier layer, and the printing layer are sequentially stacked from inside to outside to obtain the easy-tear packaging film;

[0079] The heat-sealing layer and the barrier layer and the barrier layer and the printing layer are dry compounded by means of an adhesive; the adhesive is a polyurethane adhesive; the dry weight of the adhesive is 4.0 g / m 2 ; the adhesive thickness is 1 μm; and the preparation method of the barrier layer comprises the following steps.

[0080] S111, polypropylene is melt-extruded and uniaxially stretched into a polypropylene film;

[0081] S112, coating a tungsten hexachloride coating layer on the polypropylene film, the thickness of the tungsten hexachloride coating layer being 1 μm, heating the polypropylene film to 135℃, using silicon monoxide as a target material, using high-energy electron beam to irradiate the silicon monoxide to deposit the silicon monoxide on the tungsten hexachloride coating layer, and performing annealing treatment at 55℃ to obtain a polypropylene film with a silicon oxide layer, the thickness of the silicon oxide layer being 1.5 μm;

[0082] S113, coating a polyvinyl alcohol modified by carboxylated trehalose on the polypropylene film with the silicon oxide layer, and performing drying treatment at 45℃ to obtain a barrier layer;

[0083] The preparation method of the printing layer comprises the following steps:

[0084] S121, uniformly mixing polypropylene particles, maleic anhydride grafted copolymerized polypropylene particles, 3, 6, 9-triethyl-3, 6, 9-trimethyl-1, 4, 7-triperoxonane, diatomite and an additive according to a mass ratio of 1:0.4:0.01:0.01:0.01, and heating and melting to obtain a molten mixture;

[0085] S122, bidirectionally stretching the molten mixture after extrusion to obtain a printing layer;

[0086] The particle size of the diatomite is 0.01 μm, and the additive is a plasticizer.

[0087]

Example 2

[0088] The present embodiment provides an easy-to-tear packaging bag, which comprises, from inside to outside, a heat-sealing layer, a barrier layer and a printing layer, the heat-sealing layer being a milky white cast polypropylene film with a thickness of 100 μm, the barrier layer being a unidirectionally stretched polypropylene film with a thickness of 30 μm, and the printing layer being a bidirectionally stretched polypropylene film with a thickness of 30 μm, and the preparation method of the easy-to-tear film comprises the following steps:

[0089] S100, preparing the heat-sealing layer, the barrier layer and the printing layer respectively;

[0090] S200, sequentially stacking the heat-sealing layer, the barrier layer and the printing layer from inside to outside to obtain an easy-to-tear packaging film;

[0091] The heat-sealing layer and the barrier layer and the barrier layer and the printing layer are dry compounded by using an adhesive; the adhesive is a polyurethane adhesive; the dry weight of the adhesive is 4.5 g / m 2 ; the thickness of the adhesive is 3 μm; and the preparation method of the barrier layer comprises the following steps:

[0092] S111, melting and extruding polypropylene to form a polypropylene film by unidirectional stretching;

[0093] S112, coating a tungsten hexachloride coating layer on the polypropylene film, the thickness of the tungsten hexachloride coating layer being 3 μm, heating the polypropylene film to 150 ℃, using silicon dioxide as a target material, irradiating the silicon dioxide with a high-energy electron beam to deposit the silicon dioxide on the tungsten hexachloride coating layer, and performing annealing treatment at 75 ℃ to obtain a polypropylene film with a silicon oxide layer, the thickness of the silicon oxide layer being 5 μm;

[0094] S113, coating a polyvinyl alcohol modified with carboxylated trehalose on the polypropylene film with the silicon oxide layer, and performing drying treatment at 65 ℃ to obtain a barrier layer;

[0095] The method for preparing the printing layer comprises:

[0096] S121, uniformly mixing polypropylene particles, maleic anhydride grafted copolymerized polypropylene particles, di-(hexadecyl) peroxydicarbonate, talcum powder and an additive according to a mass ratio of 1:0.6:0.1:0.1:0.1, and heating and melting to obtain a molten mixture;

[0097] S122, bidirectionally stretching the molten mixture after extrusion to obtain a printing layer;

[0098] The talcum powder has a particle size of 0.1 μm, and the additive is a plasticizer and a toughener.

[0099]

Embodiment 3

[0100] The present embodiment provides an easy-to-tear packaging bag, which comprises, from inside to outside, a heat-sealing layer, a barrier layer and a printing layer, the heat-sealing layer being a milky white cast polypropylene film with a thickness of 15 μm, the barrier layer being a unidirectionally stretched polypropylene film with a thickness of 20 μm, and the printing layer being a bidirectionally stretched polypropylene film with a thickness of 70 μm, and the method for preparing the easy-to-tear film comprises the following steps:

[0101] S100, preparing the heat-sealing layer, the barrier layer and the printing layer respectively;

[0102] S200, sequentially stacking the heat-sealing layer, the barrier layer and the printing layer from inside to outside to obtain an easy-to-tear packaging film;

[0103] The heat-sealing layer and the barrier layer and the barrier layer and the printing layer are dry compounded by using an adhesive; the adhesive is a polyurethane adhesive; the dry weight of the adhesive is 4.4 g / m 2 ; the thickness of the adhesive is 3 μm; and the method for preparing the barrier layer comprises:

[0104] S111, melting and extruding polypropylene to form a polypropylene film by unidirectional stretching;

[0105] S112, coating a tungsten hexachloride coating layer on the polypropylene film, the thickness of the tungsten hexachloride coating layer being 3 μm, heating the polypropylene film to 145 ℃, using silicon dioxide as a target material, irradiating the silicon dioxide with a high-energy electron beam to deposit the silicon dioxide on the tungsten hexachloride coating layer, and performing annealing treatment at 65 ℃ to obtain a polypropylene film with a silicon oxide layer, the thickness of the silicon oxide layer being 4 μm;

[0106] S113, coating a polyvinyl alcohol modified with carboxylated trehalose on the polypropylene film with the silicon oxide layer, and drying at 60 ℃ to obtain a barrier layer;

[0107] The method for preparing the printing layer comprises:

[0108] S121, uniformly mixing polypropylene particles, maleic anhydride grafted copolymerized polypropylene particles, di-(hexadecyl) peroxydicarbonate, talcum powder and an additive according to a mass ratio of 1:0.5:0.05:0.05:0.05, and heating and melting to obtain a molten mixture;

[0109] S122, bidirectionally stretching the molten mixture after extrusion to obtain a printing layer;

[0110] The talcum powder has a particle size of 0.05 μm, and the additive is a plasticizer and a toughener.

[0111]

Example 4

[0112] The present example provides an easy-to-tear packaging bag, which comprises, from inside to outside, a heat-sealing layer, a barrier layer and a printing layer, the heat-sealing layer being a milky white cast polypropylene film with a thickness of 15 μm, the barrier layer being a unidirectionally stretched polypropylene film with a thickness of 19 μm, and the printing layer being a bidirectionally stretched polypropylene film with a thickness of 70 μm, and the method for preparing the easy-to-tear film comprises the following steps:

[0113] S100, preparing the heat-sealing layer, the barrier layer and the printing layer respectively;

[0114] S200, sequentially stacking the heat-sealing layer, the barrier layer and the printing layer from inside to outside to obtain an easy-to-tear packaging film;

[0115] The heat-sealing layer and the barrier layer and the barrier layer and the printing layer are dry compounded by using an adhesive; the adhesive is a polyurethane adhesive; the dry weight of the adhesive is 4.2 g / m 2 ; the thickness of the adhesive is 3 μm; and the method for preparing the barrier layer comprises:

[0116] S111, melting and extruding polypropylene to form a polypropylene film by unidirectional stretching;

[0117] S112, coating a tungsten hexachloride coating layer on the polypropylene film, the thickness of the tungsten hexachloride coating layer being 3 μm, heating the polypropylene film to 140℃, using silicon dioxide as a target material, irradiating the silicon dioxide with a high-energy electron beam to deposit the silicon dioxide on the tungsten hexachloride coating layer, and performing annealing treatment at 65℃ to obtain a polypropylene film with a silicon oxide layer, the thickness of the silicon oxide layer being 4.5 μm;

[0118] S113, coating a polyvinyl alcohol modified with carboxylated trehalose on the polypropylene film with the silicon oxide layer, and drying at 55℃ to obtain a barrier layer;

[0119] The method for preparing the printing layer comprises:

[0120] S121, uniformly mixing polypropylene particles, maleic anhydride grafted copolymerized polypropylene particles, di-(hexadecyl) peroxydicarbonate, talc powder and an additive according to a mass ratio of 1:0.4:0.05:0.05:0.05, and heating and melting to obtain a molten mixture;

[0121] S122, bidirectionally stretching the molten mixture after extrusion to obtain a printing layer;

[0122] The talc powder has a particle size of 0.05 μm, and the additive is a plasticizer, a toughening agent and a heat-resistant modifier.

[0123] Comparative Example 1

[0124] The present comparative example provides a packaging film comprising, from inside to outside, a heat-sealing layer, a barrier layer and a printing layer in sequence, the heat-sealing layer being a cast polypropylene film with a thickness of 15 μm, the barrier layer being a unidirectionally stretched polypropylene film with a thickness of 20 μm, and the printing layer being a bidirectionally stretched polypropylene film with a thickness of 70 μm, and the method for preparing the easy-to-tear film comprises the following steps:

[0125] S100, preparing the heat-sealing layer, the barrier layer and the printing layer respectively;

[0126] S200, sequentially stacking the heat-sealing layer, the barrier layer and the printing layer from inside to outside to obtain an easy-to-tear packaging film;

[0127] The heat-sealing layer and the barrier layer, and the barrier layer and the printing layer are fixed by an adhesive, and the adhesive is a polyurethane adhesive.

[0128] Comparative Example 2

[0129] The present comparative example provides a packaging film comprising, from inside to outside, a heat-sealing layer, a barrier layer and a printing layer in sequence, the heat-sealing layer being a milky white cast polypropylene film with a thickness of 15 μm, the barrier layer being a unidirectionally stretched polypropylene film with a thickness of 20 μm, and the printing layer being a bidirectionally stretched polypropylene film with a thickness of 70 μm, and the method for preparing the easy-to-tear film comprises the following steps:

[0130] S100, respectively preparing a heat-sealing layer, a barrier layer and a printing layer;

[0131] S200, sequentially stacking from inside to outside in the order of the heat-sealing layer, the barrier layer and the printing layer to obtain the easy-tear packaging film;

[0132] The heat-sealing layer and the barrier layer, and the barrier layer and the printing layer are fixed by an adhesive, and the adhesive is a polyurethane adhesive.

[0133] The preparation method of the barrier layer comprises:

[0134] S111, melting and extruding polypropylene to uniaxially stretch into a polypropylene film;

[0135] S112, heating the polypropylene film to 130℃, using silicon dioxide as a target material, and using a high-energy electron beam to irradiate the silicon dioxide to deposit the silicon dioxide on the polypropylene film to obtain a polypropylene film with a silicon oxide layer, and the thickness of the silicon oxide layer is 3μm, thereby obtaining the barrier layer.

[0136]

Performance test

[0137] 1. The samples of Examples 1-4 and Comparative Examples 1-2 were cooked at 121℃ for 20min, and whether they were delaminated was observed;

[0138] 2. The water vapor transmission rates of the samples of Examples 1-4 and Comparative Examples 1-2 before and after cooking were detected;

[0139] 3. Whether Examples 1-4 and Comparative Examples 1-2 had the straight-line easy-tear function was detected according to GB / T 3917.2-2009;

[0140] 4. The packaging films of Examples 1-4 and Comparative Examples 1-2 were made into packaging bags, and after placing a facial mask in the packaging bags and sealing the bags, the changes of the facial mask and the packaging bags were observed after three months of storage at normal temperature and pressure, and the moisture change of the facial mask was detected.

[0141] Test results

[0142] 1. The samples of Examples 1-4 and Comparative Examples 1-2 were cooked at 121℃ for 20min, and the samples in Examples 1-4 were not delaminated, while Comparative Example 1 was slightly delaminated and Comparative Example 2 was not delaminated;

[0143] 2. The water vapor transmission rates of the samples of Examples 1-4 and Comparative Examples 1-2 before and after cooking are shown in Table 1;

[0144] Table 1

[0145]

[0146] 3. The tearability of the packaging films of Examples 1-4 and Comparative Examples 1-2 was detected according to GB / T 3917.2-2009, and Examples 1-4 all had straight-line tearability, Comparative Example 1 did not have straight-line tearability, and Comparative Example 2 had straight-line tearability, and the tear strength of Examples 1-4 and Comparative Examples 1-2 is shown in Table 2.

[0147] Table 2

[0148]

[0149] 4. The packaging films of Examples 1-4 and Comparative Examples 1-2 were made into packaging bags, and after the face masks were placed in the packaging bags and the bags were sealed, the bags were placed at room temperature and pressure for three months, and the face masks in Examples 1-4 did not discolor, and the flatness of the packaging bags was also good, the face masks in Comparative Example 1 discolored, and the flatness of the packaging bag was not good, the face masks in Comparative Example 2 did not discolor, and the flatness of the packaging bag was not good, and the moisture change rate of the face masks is shown in Table 3.

[0150] Table 3

[0151]

[0152] From the above results, it can be seen that the tearable packaging film of the present application has good tearability and barrier properties, and still has good barrier properties after high-temperature cooking.

[0153] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can make equivalent replacements or changes according to the technical solution and inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. An easy-tear packaging film, characterized in that, include: Heat-sealing layer (100), barrier layer (200) and printed layer (300). The heat-sealing layer (100) comprises polypropylene and color masterbatch; The barrier layer (200) covers the heat-sealing layer (100), and the barrier layer (200) comprises polypropylene and silicon oxide; The printed layer (300) covers the barrier layer (200), and the printed layer (300) includes polypropylene, maleic anhydride grafted copolymer polypropylene, peroxide and filler; The mass ratio of the polypropylene, the maleic anhydride-grafted copolymer polypropylene, the peroxide, and the filler is 1:(0.4-0.6):(0.01-0.1):(0.01-0.1); the filler has a particle size of 0.01μm-0.1μm, and the peroxide is at least one selected from 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane and di(hexadecyl)dicarbonate peroxide. The method for preparing the barrier layer includes: S111. Polypropylene is melt-extruded and uniaxially stretched into a polypropylene film; S112. After coating the polypropylene film with an adhesion-enhancing coating, the polypropylene film is sequentially subjected to vapor deposition and annealing treatment using a silicon-containing target to obtain a polypropylene film with a silicon oxide layer having a thickness of 1.5 μm-5 μm; the adhesion-enhancing coating is a tungsten hexaoxide coating, and the silicon-containing target is at least one of silicon monoxide and silicon dioxide. S113. After coating a protective coating with a thickness of 1μm-3μm onto a polypropylene film with a silicon oxide layer, the film is dried to obtain the barrier layer. The protective coating is carboxylated trehalose-modified polyvinyl alcohol.

2. The easy-tear packaging film according to claim 1, characterized in that, The thickness of the heat-sealing layer (100) is 65μm-100μm.

3. The easy-tear packaging film according to claim 1, characterized in that, The thickness of the barrier layer (200) is 15μm-30μm.

4. The easy-tear packaging film according to claim 1, characterized in that, The thickness of the printed layer (300) is 15μm-30μm.

5. The easy-tear packaging film according to claim 1, characterized in that, The water vapor transmission rate of the easy-tear packaging film is less than 0.5 g / (m²). 2 (24hrs) 6. The easy-tear packaging film according to claim 1, characterized in that, The transverse heat shrinkage rate of the easy-tear packaging film is less than or equal to 1%.

7. The easy-tear packaging film according to claim 1, characterized in that, The longitudinal heat shrinkage rate of the easy-tear packaging film is less than or equal to 1%.

8. A method for preparing an easy-tear packaging film, used to prepare the easy-tear packaging film as described in any one of claims 1-7, characterized in that, include: S100, prepare the heat-sealing layer, barrier layer and printing layer respectively; S200: The heat-sealing layer, the barrier layer, and the printed layer are stacked sequentially from the inside out to obtain the easy-tear packaging film; The heat-sealing layer and the barrier layer, as well as the barrier layer and the printed layer, are fixed together by adhesives.

9. The preparation method according to claim 8, characterized in that, The adhesive is a polyurethane adhesive.

10. The preparation method according to claim 8, characterized in that, The dry weight of the adhesive is 4.0 g / m³. 2 -4.5g / m 2 .

11. The preparation method according to claim 8, characterized in that, The adhesive coating thickness is 1μm-3μm.

12. The preparation method according to claim 8, characterized in that, In step S112, the annealing temperature is 55℃-75℃.

13. The preparation method according to claim 8, characterized in that, In step S113, the drying temperature is 45℃-65℃.

14. The preparation method according to claim 8, characterized in that, The method for preparing the printed layer includes: S121. Prepare printing layer raw materials by heating and melting the printing layer raw materials to obtain a molten mixture; S122. The molten mixture is extruded and then biaxially stretched to obtain the printed layer; The printing layer raw materials include polypropylene particles, maleic anhydride grafted copolymer polypropylene particles, peroxides, and fillers.

15. The preparation method according to claim 14, characterized in that, The printing layer material also includes additives; The additives include at least one of plasticizers, toughening agents, and heat-resistant modifiers.

16. The preparation method according to claim 15, characterized in that, The mass ratio of the additive to the polypropylene particles is (0.01-0.1):1.

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