A biaxially stretched polyethylene film material and a high-temperature-resistant and deformation-resistant biaxially stretched polyethylene film

Abstract

The present application relates to the technical fields of film and film material preparation, and specifically discloses a biaxial stretching polyethylene film material and a high-temperature-resistant and deformation-resistant biaxial stretching polyethylene film.The biaxial stretching polyethylene film material comprises a first extrusion layer material, a second extrusion layer material and a third extrusion layer material, the first extrusion layer material comprises multi-carbon copolymerized polyethylene and silicon dioxide, the second extrusion layer material comprises multi-carbon copolymerized polyethylene, and the third extrusion layer material comprises multi-carbon copolymerized polyethylene and silicon dioxide.The biaxial stretching polyethylene film prepared from the biaxial stretching polyethylene film material has low haze, high-temperature resistance and deformation resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thin film material preparation, and particularly relates to a biaxially oriented polyethylene film material and a high-temperature-resistant and deformation-resistant biaxially oriented polyethylene film. BACKGROUND

[0002] The biaxially oriented polyethylene film (BOPE) is a film formed by sequentially stretching a special LLDPE or HDPE raw material in the longitudinal direction and then in the transverse direction; the biaxially oriented polyethylene film has high heat sealing strength, good longitudinal and transverse tensile strength, and advantages such as moisture resistance and foldability. Therefore, the biaxially oriented polyethylene film is widely used in various packaging materials.

[0003] Chinese patent 201911017167.8 discloses a biaxially oriented polyethylene film BOPE composition, a biaxially oriented polyethylene film and a composite film and application thereof; the composition comprises a first extrusion layer material, a second extrusion layer material and a third extrusion layer material, the first extrusion layer material, the second extrusion layer material and the third extrusion layer material each contain a multi-carbon copolymerized polyethylene, and the multi-carbon copolymerized polyethylene is a C4-C8 copolymerized polyethylene. The polyethylene film and the composite film containing the composition have excellent puncture resistance, excellent barrier property, low odor and easy recycling, and other excellent properties. However, research shows that the haze of the biaxially oriented polyethylene film prepared from the composition needs to be further reduced. SUMMARY

[0004] In order to overcome at least one of the technical problems in the prior art, the present application first provides a biaxially oriented polyethylene film material.

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

[0006] The present application provides a biaxially oriented polyethylene film material, comprising a first extrusion layer material, a second extrusion layer material and a third extrusion layer material, characterized in that,

[0007] The first extrusion layer material comprises multi-carbon copolymerized polyethylene and silicon dioxide;

[0008] The second extrusion layer material comprises multi-carbon copolymerized polyethylene;

[0009] The third extrusion layer material comprises multi-carbon copolymerized polyethylene and silicon dioxide.

[0010] Preferably, the weight ratio of the multi-carbon copolymerized polyethylene to the silicon dioxide in the first extrusion layer material and the third extrusion layer material is 100:1-10.

[0011] Further preferably, the weight ratio of the multi-carbon copolymerized polyethylene to the silicon dioxide in the first extrusion layer material and the third extrusion layer material is 100:4-6;

[0012] Most preferably, the weight ratio of the multi-carbon copolyethylene and the silicon dioxide in the first extrusion layer and the third extrusion layer is 100:5.

[0013] Preferably, the multi-carbon copolyethylene is C4-C8 copolyethylene.

[0014] Preferably, the silicon dioxide is modified silicon dioxide.

[0015] The modified silicon dioxide is prepared by the following method:

[0016] (1) Take silicon dioxide and add it to water, stir until uniform to obtain a silicon dioxide-water mixture;

[0017] (2) Adjust the pH of the silicon dioxide-water mixture to 8-10, then add sodium lignosulfonate, stir for 30-60 min to obtain a second mixture;

[0018] (3) Add pectolite powder to the second mixture, stir for 1-2 h, then separate the solid, dry the solid to obtain the modified silicon dioxide.

[0019] The inventors surprisingly found that, in the first extrusion layer and the third extrusion layer of the biaxially stretched polyethylene film material, adding the modified silicon dioxide obtained by mixing and modifying silicon dioxide with pectolite powder by the above method can significantly reduce the haze of the prepared biaxially stretched polyethylene film material compared to adding unmodified silicon dioxide.

[0020] Preferably, the weight ratio of silicon dioxide to water in step (1) is 1:10-15.

[0021] Most preferably, the weight ratio of silicon dioxide to water in step (1) is 1:12.

[0022] Preferably, the weight ratio of the silicon dioxide-water mixture to sodium lignosulfonate in step (2) is 100:4-6.

[0023] Most preferably, the weight ratio of the silicon dioxide-water mixture to sodium lignosulfonate in step (2) is 100:5.

[0024] Preferably, the weight ratio of the second mixture to pectolite powder in step (3) is 100:2-4.

[0025] Preferably, the weight ratio of the second mixture to pectolite powder in step (3) is 100:3.

[0026] Preferably, the weight ratio of the first extrusion layer, the second extrusion layer, and the third extrusion layer is 1:1-3:1.

[0027] Most preferably, the weight ratio of the first extrusion layer, the second extrusion layer and the third extrusion layer is 1:2:1.

[0028] The application also provides a high-temperature-resistant and deformation-resistant biaxially stretched polyethylene film prepared from the biaxially stretched polyethylene film material.

[0029] Beneficial effects: The application first provides a brand-new biaxially stretched polyethylene film material. Research shows that, in the first extrusion layer and the third extrusion layer of the biaxially stretched polyethylene film material, the modified silicon dioxide obtained by mixing and modifying silicon borocalcite powder with silicon dioxide through the above method is added; compared with adding unmodified silicon dioxide, the haze of the prepared biaxially stretched polyethylene film material can be greatly reduced.

[0030] In addition, since the copolymerized polyethylene has high-temperature resistance and high tensile strength; therefore, the biaxially stretched polyethylene film prepared from the biaxially stretched polyethylene film material has not only low haze, but also high-temperature resistance and deformation resistance. DETAILED DESCRIPTION

[0031] The application will be further explained in combination with specific embodiments, but the embodiments do not limit the application in any form.

[0032] The multi-carbon copolymerized polyethylene in the following embodiments is a BOPE special material of Sinopec. The remaining raw materials are conventional raw materials that can be purchased or prepared by conventional methods by those skilled in the art.

[0033] Preparation of biaxially stretched polyethylene film material and film in Example 1

[0034] Raw material weight part composition of biaxially stretched polyethylene film material:

[0035] The first extrusion layer is composed of multi-carbon copolymerized polyethylene and silicon dioxide with a weight ratio of 100:5;

[0036] The second extrusion layer is multi-carbon copolymerized polyethylene;

[0037] The third extrusion layer is composed of multi-carbon copolymerized polyethylene and silicon dioxide with a weight ratio of 100:5;

[0038] The weight ratio of the first extrusion layer, the second extrusion layer and the third extrusion layer is 1:2:1.

[0039] Preparation method of biaxially stretched polyethylene film:

[0040] The first extrusion layer material, the second extrusion layer material and the third extrusion layer material are respectively put into an extruder for melt extrusion, and then the obtained product is subjected to cast sheet cooling, longitudinal stretching, transverse stretching, traction thickness measurement and winding treatment to obtain the biaxially stretched polyethylene film material.

[0041] Example 2 biaxially stretched polyethylene film material and film preparation

[0042] The raw material weight part composition of the biaxially stretched polyethylene film material is as follows:

[0043] The first extrusion layer material is composed of multi-carbon copolymerized polyethylene and modified silicon dioxide at a weight ratio of 100:5;

[0044] The second extrusion layer material is multi-carbon copolymerized polyethylene;

[0045] The third extrusion layer material is composed of multi-carbon copolymerized polyethylene and modified silicon dioxide at a weight ratio of 100:5;

[0046] The weight ratio of the first extrusion layer material, the second extrusion layer material and the third extrusion layer material is 1:2:1;

[0047] The modified silicon dioxide is prepared by the following method:

[0048] (1) Take silicon dioxide and add it to water, and stir to obtain a silicon dioxide-water mixture; wherein the weight ratio of silicon dioxide to water is 1:12;

[0049] (2) Adjust the pH value of the silicon dioxide-water mixture to 9, then add sodium lignosulfonate and stir for 40 min to obtain a second mixture; wherein the weight ratio of the silicon dioxide-water mixture to sodium lignosulfonate is 100:5;

[0050] (3) Add pectolite powder to the second mixture, stir for 1.5 h, then separate the solid, and dry the solid to obtain the modified silicon dioxide; wherein the weight ratio of the second mixture to pectolite powder is 100:3.

[0051] The preparation method of the biaxially stretched polyethylene film is as follows:

[0052] The first extrusion layer material, the second extrusion layer material and the third extrusion layer material are respectively put into an extruder for melt extrusion, and then the obtained product is subjected to cast sheet cooling, longitudinal stretching, transverse stretching, traction thickness measurement and winding treatment to obtain the biaxially stretched polyethylene film material.

[0053] Example 3 biaxially stretched polyethylene film material and film preparation

[0054] The raw material weight part composition of the biaxially stretched polyethylene film material is as follows:

[0055] The first extrusion layer is composed of multi-carbon copolyethylene and modified silicon dioxide with a weight ratio of 100:4;

[0056] The second extrusion layer is multi-carbon copolyethylene;

[0057] The third extrusion layer is composed of multi-carbon copolyethylene and modified silicon dioxide with a weight ratio of 100:6;

[0058] The weight ratio of the first extrusion layer, the second extrusion layer and the third extrusion layer is 1:1:1;

[0059] The modified silicon dioxide is prepared by the following method:

[0060] (1) Take silicon dioxide and add it to water, stir until uniform to obtain a silicon dioxide-water mixture; wherein the weight ratio of silicon dioxide to water is 1:10;

[0061] (2) Adjust the pH value of the silicon dioxide-water mixture to 8, then add sodium lignosulfonate and stir for 30 minutes to obtain a second mixture; wherein the weight ratio of the silicon dioxide-water mixture to sodium lignosulfonate is 100:6;

[0062] (3) Add pectolite powder to the second mixture and stir for 1 hour, then separate the solid, dry the solid, and obtain the modified silicon dioxide; wherein the weight ratio of the second mixture to pectolite powder is 100:4.

[0063] A method for preparing a biaxially stretched polyethylene film:

[0064] The first extrusion layer, the second extrusion layer and the third extrusion layer are respectively placed in an extruder for melt extrusion, then the biaxially stretched polyethylene film material is obtained after casting sheet cooling, longitudinal stretching, transverse stretching, traction thickness measurement and winding treatment.

[0065] Example 4 biaxially stretched polyethylene film material and film preparation

[0066] The raw material weight parts composition of the biaxially stretched polyethylene film material:

[0067] The first extrusion layer is composed of multi-carbon copolyethylene and modified silicon dioxide with a weight ratio of 100:6;

[0068] The second extrusion layer is multi-carbon copolyethylene;

[0069] The third extrusion layer is composed of multi-carbon copolyethylene and modified silicon dioxide with a weight ratio of 100:4;

[0070] The weight ratio of the first extrusion layer material, the second extrusion layer material and the third extrusion layer material is 1:3:1.

[0071] The modified silicon dioxide is prepared by the following method:

[0072] (1) The silicon dioxide is added into water and stirred to obtain a silicon dioxide-water mixture; the weight ratio of the silicon dioxide to water is 1:15;

[0073] (2) The pH value of the silicon dioxide-water mixture is adjusted to 10, then sodium lignosulfonate is added and stirred for 60 min to obtain a second mixture; the weight ratio of the silicon dioxide-water mixture to sodium lignosulfonate is 100:4;

[0074] (3) The second mixture is added with calciosilicate powder and stirred for 2 h, then the solid is separated and dried to obtain the modified silicon dioxide; the weight ratio of the second mixture to the calciosilicate powder is 100:2.

[0075] The preparation method of the biaxially stretched polyethylene film:

[0076] The first extrusion layer material, the second extrusion layer material and the third extrusion layer material are respectively put into an extruder for melt extrusion, then the biaxially stretched polyethylene film material is obtained through the processes of casting sheet cooling, longitudinal stretching, transverse stretching, traction thickness measurement and winding.

[0077] Table 1. Haze of the biaxially stretched polyethylene film material

[0078]

[0079]

[0080] As can be seen from the test results in Table 1, the haze of the biaxially stretched polyethylene film material prepared in Examples 2-4 is much smaller than that of the biaxially stretched polyethylene film material prepared in Example 1; this shows that: in the first extrusion layer material and the third extrusion layer material of the biaxially stretched polyethylene film material, the modified silicon dioxide obtained by mixing and modifying the silicon dioxide with the calciosilicate powder by the method of the present application is added; compared with the unmodified silicon dioxide, the haze of the biaxially stretched polyethylene film material prepared can be greatly reduced.

Claims

1. A biaxially oriented polyethylene film material, comprising a first extrusion layer, a second extrusion layer and a third extrusion layer, characterized in that the first extrusion layer comprises multi-carbon copolymerized polyethylene and silicon dioxide; the second extrusion layer comprises multi-carbon copolymerized polyethylene; and the third extrusion layer comprises multi-carbon copolymerized polyethylene and silicon dioxide.

2. The biaxially oriented polyethylene film material of claim 1, wherein the multi-carbon copolymerized polyethylene is C4-C8 copolymerized polyethylene.

3. The biaxially oriented polyethylene film material of claim 1, wherein the silicon dioxide is modified silicon dioxide.

4. The biaxially oriented polyethylene film material of claim 1, wherein the weight ratio of the multi-carbon copolymerized polyethylene to the silicon dioxide in the first extrusion layer and the third extrusion layer is 100:1-10.

5. The biaxially oriented polyethylene film material of claim 1, wherein the modified silicon dioxide is prepared by the following method: (1) taking silicon dioxide and adding it to water, stirring to obtain a silicon dioxide-water mixture; (2) adjusting the pH value of the silicon dioxide-water mixture to 8-10, then adding sodium lignosulfonate, stirring for 30-60 min to obtain a second mixture; (3) adding pectolite powder to the second mixture, stirring for 1-2 h, then separating the solid, drying the solid to obtain the modified silicon dioxide.

6. The biaxially oriented polyethylene film material of claim 5, wherein the weight ratio of the silicon dioxide-water mixture to the sodium lignosulfonate in step (2) is 100:4-6.

7. The biaxially oriented polyethylene film material of claim 5, wherein the weight ratio of the multi-carbon copolymerized polyethylene to the silicon dioxide in the first extrusion layer and the third extrusion layer is 100:4-6.

8. The biaxially oriented polyethylene film material of claim 5, wherein the weight ratio of the silicon dioxide to water in step (1) is 1:10-15.

9. The biaxially oriented polyethylene film material of claim 5, wherein the weight ratio of the silicon dioxide to water in step (1) is 1:

12.

10. The biaxially oriented polyethylene film material of claim 5, wherein the weight ratio of the second mixture to the pectolite powder in step (3) is 100:2-4.

11. The biaxially oriented polyethylene film material of claim 5, wherein the weight ratio of the second mixture to the pectolite powder in step (3) is 100:

3.

12. A biaxially oriented polyethylene film material prepared by the method of any one of claims 1-11. ​ 2. The biaxially oriented polyethylene film material according to claim 1, characterized in that, ​ 3. The biaxially oriented polyethylene film material according to claim 1, characterized in that, ​ 4. The biaxially oriented polyethylene film material according to claim 3, characterized in that, ​ 5. The biaxially oriented polyethylene film material according to claim 1, wherein, ​ 6. The biaxially oriented polyethylene film material according to claim 1, wherein, ​ 7. A high temperature resistant, set resistant, biaxially oriented polyethylene film, characterized in that, ​

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