High-barrier pe composite film and preparation method thereof

Abstract

The application relates to the technical field of PE composite film preparation, and particularly discloses a high-barrier PE composite film and a preparation method thereof. The high-barrier PE composite film comprises, from outside to inside, an outer surface layer, an intermediate layer and an inner surface layer; the preparation raw material of the intermediate layer is PVA resin; and the preparation raw material of the inner surface layer is low-temperature-resistant PE resin; the preparation raw material of the outer surface layer comprises the following components in parts by weight: PE resin 50-100 parts; wear-resistant filler 30-50 parts; and lubricant 1-3 parts. The wear-resistant filler is added in the outer surface layer of the high-barrier PE composite film, which helps to improve the wear resistance of the barrier PE composite film, and the high-barrier PE composite film has important application value.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of PE composite film preparation, in particular to a high-barrier PE composite film and a preparation method thereof. BACKGROUND

[0002] With the increasing of people's living standards and consumption level, people's requirements for various packaging materials are getting higher and higher, such as the packaging materials for food need to have high barrier property to prolong the shelf life of food. The composite packaging material with high barrier property has good effect on preserving rice and other foods. The composite packaging material is composed of high barrier materials such as EVOH, PVDC, PET, PA and PE, PP, etc. Common composite materials include PA / PE five-layer nylon composite film, PA / PP five-layer film, PA / EVOH / PE or PE / EVOH / PE high barrier film, PE / PVA coating / PE composite film, etc.

[0003] For example, Chinese invention patent 201911360872.8 discloses an antibacterial high-oxygen-barrier PE composite film and a preparation method thereof. The antibacterial high-oxygen-barrier PE composite film is prepared by three-layer co-extrusion from the outside to the inside, and is composed of a PE film layer, a PVA film layer and a PE film layer. It effectively improves the moisture resistance, oxygen resistance and poor bonding force between film layers of the existing PE composite film, and has excellent antibacterial and antistatic properties, good comprehensive performance advantages and wide application space. However, the inventors found in the research that the outer surface layer of the high-oxygen-barrier PE composite film is not wear-resistant, and needs to be further improved. SUMMARY

[0004] In order to overcome at least one of the technical problems in the prior art, the present application provides a high-barrier PE composite film and a preparation method thereof.

[0005] The technical solution of the present application to solve the above technical problems is as follows:

[0006] The present application first provides a high-barrier PE composite film, which is composed of an outer surface layer, an intermediate layer and an inner surface layer from the outside to the inside. The intermediate layer is prepared from PVA resin, and the inner surface layer is prepared from PE resin. The outer surface layer is prepared from the following components by weight:

[0007] PE resin 50-100 parts, wear-resistant filler 30-50 parts, lubricant 1-3 parts.

[0008] The present application adds wear-resistant filler to the outer surface layer of the high-barrier PE composite film, which helps to improve the wear resistance of the barrier PE composite film and has important application value.

[0009] Preferably, the outer surface layer is prepared from the following components by weight:

[0010] PE resin 60-90 parts; wear-resistant filler 30-40 parts; lubricant 1-2 parts.

[0011] Most preferably, the raw material for preparing the outer layer comprises the following components by weight:

[0012] PE resin 70 parts; wear-resistant filler 28 parts; lubricant 2 parts.

[0013] Preferably, the wear-resistant filler is fluorite powder.

[0014] Preferably, the fluorite powder is 300-500 mesh fluorite powder.

[0015] Most preferably, the fluorite powder is 400 mesh fluorite powder.

[0016] Preferably, the wear-resistant filler is modified fluorite powder.

[0017] The modified fluorite powder is prepared by the following method:

[0018] (1) Take fluorite powder and soak it in an acid solution for 3-5 hours, then take it out and wash it until it is neutral to obtain acid-treated fluorite powder;

[0019] (2) Add the acid-treated fluorite powder to water and stir until it is evenly dispersed to obtain a fluorite powder dispersion;

[0020] (3) Add diethylene triamine pentaacetic acid to the fluorite powder dispersion, then add calcium nitrate, stir for 2-5 hours, separate the solid, and dry the solid to obtain the modified fluorite powder.

[0021] The inventors have surprisingly found that, in the high-barrier PE composite film of the present application, the addition of the modified fluorite powder prepared by the above method can greatly improve the wear resistance of the high-barrier PE composite film compared to the addition of unmodified fluorite powder.

[0022] Preferably, the fluorite powder in step (1) is 300-500 mesh fluorite powder.

[0023] Most preferably, the fluorite powder is 300-500 mesh fluorite powder.

[0024] Preferably, the acid in step (1) is a 50%-70% by mass sulfuric acid aqueous solution.

[0025] Most preferably, the acid in step (1) is a 60% by mass sulfuric acid aqueous solution.

[0026] Preferably, the weight ratio of acid-treated fluorite powder to water in step (2) is 1:5-10.

[0027] Most preferably, the weight ratio of the fluorite powder after acid treatment in step (2) to water is 1:7.

[0028] Preferably, the weight ratio of the fluorite powder dispersion in step (3) to diethylene triamine pentaacetic acid and calcium nitrate is 100:15-25:10-20.

[0029] Most preferably, the weight ratio of the fluorite powder dispersion in step (3) to diethylene triamine pentaacetic acid and calcium nitrate is 100:20:15.

[0030] The application also provides a preparation method of the high-barrier PE composite film, comprising the following steps:

[0031] The outer layer raw material, the middle layer raw material and the inner layer raw material are respectively melted and extruded through an extruder, converged in the same die, and then the high-barrier PE composite film is obtained after casting, longitudinal stretching, transverse stretching, traction and winding treatment.

[0032] Beneficial effects: The application provides a brand-new high-barrier PE composite film; the wear-resistant filler is added in the outer layer of the high-barrier PE composite film, which helps to improve the wear resistance of the high-barrier PE composite film, and has important application value. DETAILED DESCRIPTION

[0033] The application will be further explained in combination with specific embodiments below, but the embodiments do not limit the application in any form.

[0034] The PE resins of the outer layer and the inner layer in the following embodiments are low-density polyethylene with the brand 3224 of Taiwan TPL in China; the PVA resin of the middle layer is PVA resin with the brand PVA-205 of Japan Kao Lai; and the remaining raw materials without the source are conventional raw materials that can be purchased by the person skilled in the art through conventional purchase channels.

[0035] Preparation of the high-barrier PE composite film in Example 1

[0036] The high-barrier PE composite film is sequentially composed of an outer layer, a middle layer and an inner layer from outside to inside; the thickness of the outer layer is 5 microns, the thickness of the middle layer is 22 microns, and the thickness of the inner layer is 3 microns; wherein the preparation raw material of the middle layer is PVA resin, and the preparation raw material of the inner layer is PE resin.

[0037] The preparation raw material of the outer layer comprises the following components in parts by weight:

[0038] PE resin 70 parts; fluorite powder 400 mesh 28 parts; lubricant (calcium stearate) 2 parts.

[0039] Preparation method: the outer surface layer raw material, the middle layer raw material and the inner surface layer raw material are respectively melted and extruded through the extruder, then converged in the same die, and then the high barrier PE composite film is obtained after casting, longitudinal stretching, transverse stretching, traction and winding treatment.

[0040] Example 2 Preparation of high barrier PE composite film

[0041] The high barrier PE composite film is sequentially from outside to inside as an outer surface layer, a middle layer and an inner surface layer; the thickness of the outer surface layer is 5 microns, the thickness of the middle layer is 22 microns, and the thickness of the inner surface layer is 3 microns; wherein the preparation raw material of the middle layer is PVA resin, and the preparation raw material of the inner surface layer is PE resin.

[0042] The preparation raw material of the outer surface layer comprises the following components by weight:

[0043] PE resin 70 parts; modified fluorite powder 28 parts; lubricant (calcium stearate) 2 parts.

[0044] The modified fluorite powder is prepared by the following method:

[0045] (1) Take 400 mesh fluorite powder and soak in a 60% mass fraction of sulfuric acid aqueous solution for 4h, then take out and wash to neutral with water to obtain acid treated fluorite powder;

[0046] (2) Add the acid treated fluorite powder to water, stir uniformly to obtain a fluorite powder dispersion; wherein the weight ratio of the acid treated fluorite powder to water is 1:7;

[0047] (3) Add diethylene triamine pentaacetic acid to the fluorite powder dispersion, then add calcium nitrate, stir for 3h, then separate the solid, dry the solid to obtain the modified fluorite powder; wherein the weight ratio of the fluorite powder dispersion to diethylene triamine pentaacetic acid and calcium nitrate is 100:20:15.

[0048] Preparation method: the outer surface layer raw material, the middle layer raw material and the inner surface layer raw material are respectively melted and extruded through the extruder, then converged in the same die, and then the high barrier PE composite film is obtained after casting, longitudinal stretching, transverse stretching, traction and winding treatment.

[0049] Preparation of high barrier PE composite film

[0050] The high barrier PE composite film is sequentially from outside to inside as an outer surface layer, a middle layer and an inner surface layer; the thickness of the outer surface layer is 5 microns, the thickness of the middle layer is 22 microns, and the thickness of the inner surface layer is 3 microns; wherein the preparation raw material of the middle layer is PVA resin, and the preparation raw material of the inner surface layer is PE resin; the preparation raw material of the outer surface layer is PE resin.

[0051] Preparation method: melt-extruding the outer surface layer raw material, the middle layer raw material and the inner surface layer raw material through an extruder respectively, then converging them in the same die, and then casting, longitudinal stretching, transverse stretching, traction and winding treatment to obtain the high-barrier PE composite film.

[0052] Preparation of the high-barrier PE composite film of Comparative Example 2

[0053] The high-barrier PE composite film comprises, from outside to inside, an outer surface layer, a middle layer and an inner surface layer; the thickness of the outer surface layer is 5 microns, the thickness of the middle layer is 22 microns, and the thickness of the inner surface layer is 3 microns; wherein the preparation raw material of the middle layer is PVA resin, and the preparation raw material of the inner surface layer is PE resin.

[0054] The preparation raw material of the outer surface layer comprises the following components by weight:

[0055] PE resin 70 parts; modified fluorite powder 28 parts; lubricant (calcium stearate) 2 parts.

[0056] The modified fluorite powder is prepared by the following method: taking 400-mesh fluorite powder, soaking it in a 60% mass fraction sulfuric acid aqueous solution for 4 h, then taking it out and washing it with water until it is neutral to obtain the acid-treated fluorite powder; and taking the acid-treated fluorite powder to obtain the modified fluorite powder.

[0057] Preparation method: melt-extruding the outer surface layer raw material, the middle layer raw material and the inner surface layer raw material through an extruder respectively, then converging them in the same die, and then casting, longitudinal stretching, transverse stretching, traction and winding treatment to obtain the high-barrier PE composite film.

[0058] Experimental Example 1

[0059] The friction loss after friction for 500 times was determined according to the method in the ASTM D3702-94 (2014) standard; the test results are shown in Table 1.

[0060] Table 1. Performance test results of the high-barrier PE composite film of the application

[0061] frictional losses high barrier pe composite film prepared in example 1 1.45％ high barrier pe composite film prepared in example 2 0.38％ high barrier pe composite film prepared in comparative example 1 2.21％ high barrier pe composite film prepared in comparative example 2 1.33％

[0062] As can be seen from the experimental results in Table 1, the friction loss of the high-barrier PE composite film prepared in Example 1 is significantly lower than that of the high-barrier PE composite film prepared in Comparative Example 1; this shows that adding the wear-resistant filler fluorite powder to the outer surface layer of the high-barrier PE composite film can significantly improve the wear resistance of the barrier PE composite film.

[0063] From the experimental results in Table 1, it can be seen that the friction loss of the high-barrier PE composite film prepared in Example 2 is further greatly lower than that of the high-barrier PE composite film prepared in Example 1; this shows that, in the high-barrier PE composite film of the present application, the addition of the modified fluorite powder prepared by the method of the present application can greatly improve the wear resistance of the high-barrier PE composite film compared with the addition of unmodified fluorite powder.

[0064] From the experimental results in Table 1, it can be seen that the friction loss of the high-barrier PE composite film prepared in Comparative Example 2 is not further greatly reduced compared with that of the high-barrier PE composite film prepared in Example 1; this shows that the modification method of the fluorite powder of the present application is very critical; the acid-treated fluorite powder obtained by simply treating with acid cannot further greatly improve the wear resistance of the high-barrier PE composite film of the present application. The modified fluorite powder obtained by dispersing the acid-treated fluorite powder and further stirring with diethylene triamine pentaacetic acid and calcium nitrate can further greatly improve the wear resistance of the high-barrier PE composite film of the present application.

Claims

1. A high-barrier PE composite film, which comprises, from outside to inside, an outer skin layer, an intermediate layer, and an inner skin layer; wherein, The preparation raw material of the intermediate layer is PVA resin, and the preparation raw material of the inner surface layer is PE resin; characterized in that the preparation raw material of the outer surface layer comprises the following components in parts by weight: PE resin 50-100 parts; wear-resistant filler 30-50 parts; lubricant 1-3 parts; The wear-resistant filler is modified fluorite powder; The modified fluorite powder is prepared by the following method: (1) fluorite powder is soaked in an acid solution for 3-5 hours, then taken out and washed to neutral to obtain acid-treated fluorite powder; (2) the acid-treated fluorite powder is added to water and stirred to obtain a fluorite powder dispersion; (3) diethylenetriamine pentaacetic acid is added to the fluorite powder dispersion, followed by the addition of calcium nitrate, stirring for 2-5 hours, separating the solid, drying the solid to obtain the modified fluorite powder; The acid in step (1) is a 50%-70% mass fraction sulfuric acid aqueous solution; The weight ratio of acid-treated fluorite powder to water in step (2) is 1:5-10; The weight ratio of fluorite powder dispersion to diethylenetriamine pentaacetic acid and calcium nitrate in step (3) is 100:15-25:10-20.

2. The high barrier PE composite film according to claim 1, characterized in that, The preparation raw material of the outer surface layer comprises the following components in parts by weight: PE resin 60-90 parts; wear-resistant filler 30-40 parts; lubricant 1-2 parts.

3. The high barrier PE composite film according to claim 1, characterized in that, The fluorite powder in step (1) is 300-500 mesh fluorite powder.

4. Process for the production of a high barrier PE composite film according to any one of claims 1 to 3, characterized in that, Comprising the following steps: The outer surface layer raw material, the intermediate layer raw material and the inner surface layer raw material are respectively melt-extruded through an extruder, converged in the same die, and then subjected to casting, longitudinal stretching, transverse stretching, traction and winding treatment to obtain the high-barrier PE composite film.