A BOPP double-sided heat-sealed film and its preparation method

Abstract

The present invention relates to the technical field of BOPP film preparation, and specifically discloses a BOPP double-sided heat-sealable film and a preparation method thereof. The BOPP double-sided heat-sealable film comprises a core layer and an outer layer. The material of the core layer is a homopolymer polypropylene resin; the material of the outer layer is a polypropylene composition; the polypropylene composition comprises the following components: 80 to 120 parts of homopolymer polypropylene resin; 30 to 50 parts of filler; 1 to 3 parts of lubricant; 0.5 to 2 parts of antioxidant; the filler comprises silicon micropowder and graphene. Studies have shown that the present invention adds a filler consisting of silicon micropowder and graphene to the outer layer material of the BOPP double-sided heat-sealable film, which can significantly improve the dustproof performance of the BOPP double-sided heat-sealable film and has important application value.

Description

Technical Field

[0001] The present invention relates to the technical field of BOPP film preparation, and in particular to a BOPP double-sided heat-sealed film and a preparation method thereof. Background Art

[0002] Since the 1990s, the rapid development of microwave heating technology has put forward new requirements for the packaging of microwave food and a class of goods that need to be microwave sterilized and disinfected. That is, the packaging material must not only have excellent barrier properties, but also have characteristics such as high temperature resistance and good microwave permeability. Therefore, in recent years, new high-barrier packaging materials have become a research and development direction in many industrialized countries in the world. This type of material has the advantages of good microwave permeability, high temperature resistance, transparency, and little influence by ambient temperature and humidity. It can be widely used in the packaging of food, medicine, cosmetics, medical devices and other goods with high packaging safety and sanitation requirements and long shelf life. It is particularly suitable as a packaging material for a class of goods that use microwave heating technology. For example, Chinese invention patent 201910319194.4 discloses a BOPP double-sided heat-sealing film and its preparation method; the BOPP double-sided heat-sealing film includes a core layer (1) and an outer layer (3), and a sub-surface layer (2) is provided between the core layer and the outer layer; wherein the material of the sub-surface layer is a polypropylene-based adhesive resin, the material of the core layer is a polypropylene composition, and the material of the outer layer is a PETG resin composition. The BOPP double-sided heat-sealed film has the advantage of being wear-resistant and has good competitiveness in the packaging field.

[0003] However, during actual use, the inventors found that the BOPP double-sided heat-sealed film prepared by the existing technology has poor dust-proof performance and is prone to adsorbing dust, which needs to be further improved. Summary of the Invention

[0004] In order to overcome at least one of the technical problems existing in the prior art, the present invention first provides a BOPP double-sided heat-sealed film and a preparation method thereof.

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

[0006] The present invention first provides a BOPP double-sided heat-sealed film, comprising a core layer and an outer layer.

[0007] The material of the core layer is homopolymer polypropylene resin;

[0008] The material of the outer layer is a polypropylene composition; the polypropylene composition comprises the following components:

[0009] Homopolymer polypropylene resin 80-120 parts; filler 30-50 parts; lubricant 1-3 parts; antioxidant 0.5-2 parts;

[0010] The filler consists of silicon micropowder and graphene.

[0011] The inventors surprisingly discovered during their research that adding fillers consisting of silicon micropowder and graphene to the outer layer material of the BOPP double-sided heat-sealed film can significantly improve the dust-proof performance of the BOPP double-sided heat-sealed film.

[0012] Preferably, the polypropylene composition comprises the following components:

[0013] Homopolymer polypropylene resin 90-110 parts; filler 30-40 parts; lubricant 1-2 parts; antioxidant 0.5-1 part.

[0014] Preferably, the filler is composed of silicon micropowder and graphene in a weight ratio of 3 to 5:1.

[0015] Most preferably, the filler consists of silicon micropowder and graphene in a weight ratio of 4:1.

[0016] Preferably, the filler is a modified filler.

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

[0018] (1) taking silicon micropowder and graphene, adding them to water, and then adding ethylenediaminetetramethylenephosphoric acid to obtain a mixed solution;

[0019] (2) Adding metal salt to the mixed solution, stirring for 2 to 5 hours, separating the solid, and drying the solid to obtain the modified filler.

[0020] In further research, the inventors found that adding a modified filler obtained by modifying silicon micropowder and graphene using the above method to the outer layer material of the BOPP double-sided heat-seal film can further improve the dust-proof performance of the BOPP double-sided heat-seal film compared to adding an unmodified filler composed of silicon micropowder and graphene.

[0021] Preferably, in step (1), the total weight of silicon powder and graphene to the amount of ethylenediaminetetramethylenephosphoric acid and water is 0.8-1.5 kg:80-150 g:10 L.

[0022] Most preferably, in step (1), the total weight of silicon powder and graphene to the amount of ethylenediaminetetramethylenephosphoric acid and water is 1kg:100g:10L.

[0023] Preferably, the weight ratio of silicon powder to graphene in step (1) is 3 to 5:1.

[0024] Most preferably, the weight ratio of silicon powder to graphene in step (1) is 4:1.

[0025] Preferably, the ratio of the mixed solution to the metal salt in step (2) is 10L:100-200g.

[0026] Most preferably, the ratio of the mixed solution to the metal salt in step (2) is 10 L:150 g.

[0027] Preferably, the metal salt is selected from magnesium chloride or titanium chloride.

[0028] Preferably, the metal salt consists of magnesium chloride and titanium chloride.

[0029] Preferably, the weight ratio of magnesium chloride to titanium chloride is 1 to 3:1.

[0030] Most preferably, the weight ratio of magnesium chloride to titanium chloride is 2:1.

[0031] In further research, the inventors discovered that, in step (2) of the method for preparing the modified filler, the modified filler obtained by simultaneously adding magnesium chloride and titanium chloride to modify silicon micropowder and graphene can significantly improve the dustproof performance of the BOPP double-sided heat-sealable film compared to the modified filler obtained by modifying silicon micropowder and graphene with only magnesium chloride or titanium chloride. In step (2) of the method for preparing the modified filler, the simultaneous addition of magnesium chloride and titanium chloride to modify silicon micropowder and graphene can synergistically improve the dustproof performance of the BOPP double-sided heat-sealable film.

[0032] The present invention also provides a method for preparing the above-mentioned BOPP double-sided heat-sealed film, which comprises the following steps:

[0033] The core layer material and the outer layer material are melt-extruded through an extruder respectively and then converged into the same die head, and then subjected to sheet casting, longitudinal stretching, transverse stretching, pulling and winding processes to obtain the BOPP double-sided heat-sealed film.

[0034] Beneficial effects: The present invention provides a new method for preparing BOPP double-sided heat-sealable film. Studies have shown that adding fillers composed of silicon micropowder and graphene to the outer layer material of the BOPP double-sided heat-sealable film can significantly improve the dust-proof performance of the BOPP double-sided heat-sealable film. The method has important application value. DETAILED DESCRIPTION

[0035] The present invention is further explained below with reference to specific examples, but the examples do not limit the present invention in any form.

[0036] The homopolypropylene resin used in the following examples is HF409 homopolypropylene produced by Hanwha Total Petrochemical; the remaining raw materials are conventional raw materials that can be purchased or prepared by conventional methods by those skilled in the art.

[0037] Example 1 BOPP double-sided heat-sealed film

[0038] The BOPP double-sided heat-sealed film consists of two outer layers and a core layer; the outer layer is 2 microns thick; the core layer is 30 microns thick;

[0039] The material of the core layer is homopolymer polypropylene resin;

[0040] The material of the outer layer is a polypropylene composition; the polypropylene composition comprises the following components: 100 parts of homopolymer polypropylene resin; 37 parts of filler; 2 parts of lubricant (calcium stearate); and 1 part of antioxidant (antioxidant 1010).

[0041] The filler consists of silicon micropowder and graphene in a weight ratio of 4:1.

[0042] The preparation method of BOPP double-sided heat-seal film is as follows: the core layer material and the outer layer material are melt-extruded through an extruder respectively and then converged into the same die head, and then subjected to sheet casting, longitudinal stretching, transverse stretching, pulling and winding to obtain the BOPP double-sided heat-seal film.

[0043] Example 2 BOPP double-sided heat-sealed film

[0044] The BOPP double-sided heat-sealed film consists of two outer layers and a core layer; the outer layer is 2 microns thick; the core layer is 30 microns thick;

[0045] The material of the core layer is homopolymer polypropylene resin;

[0046] The material of the outer layer is a polypropylene composition; the polypropylene composition comprises the following components: 100 parts of homopolymer polypropylene resin; 37 parts of modified filler; 2 parts of lubricant (calcium stearate); and 1 part of antioxidant (antioxidant 1010).

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

[0048] (1) taking silicon micropowder and graphene, adding them to water, and then adding ethylenediaminetetramethylenephosphoric acid to obtain a mixed solution; wherein the total weight ratio of silicon micropowder and graphene to ethylenediaminetetramethylenephosphoric acid and water is 1kg:100g:10L; and the weight ratio of silicon micropowder to graphene is 4:1;

[0049] (2) adding a metal salt to the mixed solution, stirring for 3 hours, separating the solid, and drying the solid to obtain the modified filler; wherein the ratio of the mixed solution to the metal salt is 10L:150g; and the metal salt is magnesium chloride.

[0050] The preparation method of BOPP double-sided heat-seal film is as follows: the core layer material and the outer layer material are melt-extruded through an extruder respectively and then converged into the same die head, and then subjected to sheet casting, longitudinal stretching, transverse stretching, pulling and winding to obtain the BOPP double-sided heat-seal film.

[0051] Example 3 BOPP double-sided heat-sealed film

[0052] The BOPP double-sided heat-sealed film consists of two outer layers and a core layer; the outer layer is 2 microns thick; the core layer is 30 microns thick;

[0053] The material of the core layer is homopolymer polypropylene resin;

[0054] The material of the outer layer is a polypropylene composition; the polypropylene composition comprises the following components: 100 parts of homopolymer polypropylene resin; 37 parts of modified filler; 2 parts of lubricant (calcium stearate); and 1 part of antioxidant (antioxidant 1010).

[0055] The modified filler is prepared by the following method:

[0056] (1) taking silicon micropowder and graphene, adding them to water, and then adding ethylenediaminetetramethylenephosphoric acid to obtain a mixed solution; wherein the total weight ratio of silicon micropowder and graphene to ethylenediaminetetramethylenephosphoric acid and water is 1kg:100g:10L; and the weight ratio of silicon micropowder to graphene is 4:1;

[0057] (2) Adding a metal salt to the mixed solution, stirring for 3 hours, separating the solid, and drying the solid to obtain the modified filler; wherein the ratio of the mixed solution to the metal salt is 10L:150g; and the metal salt is titanium chloride.

[0058] The preparation method of BOPP double-sided heat-seal film is as follows: the core layer material and the outer layer material are melt-extruded through an extruder respectively and then converged into the same die head, and then subjected to sheet casting, longitudinal stretching, transverse stretching, pulling and winding to obtain the BOPP double-sided heat-seal film.

[0059] Example 4 BOPP double-sided heat-sealed film

[0060] The BOPP double-sided heat-sealed film consists of two outer layers and a core layer; the outer layer is 2 microns thick; the core layer is 30 microns thick;

[0061] The material of the core layer is homopolymer polypropylene resin;

[0062] The material of the outer layer is a polypropylene composition; the polypropylene composition comprises the following components: 100 parts of homopolymer polypropylene resin; 37 parts of modified filler; 2 parts of lubricant (calcium stearate); and 1 part of antioxidant (antioxidant 1010).

[0063] The modified filler is prepared by the following method:

[0064] (1) taking silicon micropowder and graphene, adding them to water, and then adding ethylenediaminetetramethylenephosphoric acid to obtain a mixed solution; wherein the total weight ratio of silicon micropowder and graphene to ethylenediaminetetramethylenephosphoric acid and water is 1kg:100g:10L; and the weight ratio of silicon micropowder to graphene is 4:1;

[0065] (2) adding a metal salt to the mixed solution, stirring for 3 hours, separating the solid, and drying the solid to obtain the modified filler; wherein the ratio of the mixed solution to the metal salt is 10L:150g; and the metal salt is composed of magnesium chloride and titanium chloride in a weight ratio of 2:1.

[0066] The preparation method of BOPP double-sided heat-seal film is as follows: the core layer material and the outer layer material are melt-extruded through an extruder respectively and then converged into the same die head, and then subjected to sheet casting, longitudinal stretching, transverse stretching, pulling and winding to obtain the BOPP double-sided heat-seal film.

[0067] Comparative Example 1 BOPP double-sided heat-sealed film

[0068] The BOPP double-sided heat-sealed film consists of two outer layers and a core layer; the outer layer is 2 microns thick; the core layer is 30 microns thick;

[0069] The material of the core layer is homopolymer polypropylene resin;

[0070] The material of the outer layer is a polypropylene composition; the polypropylene composition comprises the following components: 100 parts of homopolymer polypropylene resin; 2 parts of lubricant (calcium stearate); and 1 part of antioxidant (antioxidant 1010).

[0071] The preparation method of BOPP double-sided heat-seal film is as follows: the core layer material and the outer layer material are melt-extruded through an extruder respectively and then converged into the same die head, and then subjected to sheet casting, longitudinal stretching, transverse stretching, pulling and winding to obtain the BOPP double-sided heat-seal film.

[0072] Experimental Example 1 Dustproof Test

[0073] 100g of talcum powder was placed in a 50cm long, 30cm wide, and 50cm high box equipped with a blower at the bottom. A 10cm long and 10cm wide BOPP double-sided heat-sealable film to be tested was hung from the top of the box. The blower was turned on to fill the box with talcum powder. After 12 hours, the BOPP double-sided heat-sealable film to be tested was weighed and the dust adsorption capacity was calculated. Dust adsorption capacity = weight of the BOPP double-sided heat-sealable film after adsorption - weight of the BOPP double-sided heat-sealable film before adsorption. The test results are shown in Table 1.

[0074] The BOPP double-sided heat-sealable film to be tested is the BOPP double-sided heat-sealable film prepared in Examples 1 to 4 and Comparative Example 1.

[0075] Table 1. Dustproof test results of BOPP double-sided heat-sealable film of the present invention

[0076] Dust adsorption capacity BOPP double-sided heat-sealed film prepared in Example 1 318mg BOPP double-sided heat-sealed film prepared in Example 2 264mg BOPP double-sided heat-sealed film prepared in Example 3 239mg BOPP double-sided heat-sealed film prepared in Example 4 157mg BOPP double-sided heat-sealed film prepared in Comparative Example 1 543mg

[0077] As can be seen from the experimental results in Table 1, the dust adsorption capacity of the BOPP double-sided heat-seal film prepared in Example 1 is significantly lower than that of the BOPP double-sided heat-seal film prepared in Comparative Example 1. This indicates that the addition of fillers composed of silicon micropowder and graphene to the outer layer material of the BOPP double-sided heat-seal film can significantly improve the dust-proof performance of the BOPP double-sided heat-seal film.

[0078] As can be seen from the experimental results in Table 1, the dust adsorption capacity of the BOPP double-sided heat-seal films prepared in Examples 2 and 3 is further reduced compared to the BOPP double-sided heat-seal film prepared in Example 1. This indicates that the addition of the modified filler obtained by modifying silicon micropowder and graphene using the method described in the present invention to the outer layer material of the BOPP double-sided heat-seal film can further improve the dust-proof performance of the BOPP double-sided heat-seal film, compared to the addition of the unmodified filler composed of silicon micropowder and graphene.

[0079] As can be seen from the experimental results in Table 1, the dust adsorption capacity of the BOPP double-sided heat-seal film prepared in Example 4 is significantly lower than that of the BOPP double-sided heat-seal films prepared in Examples 2 and 3. This indicates that the modified filler obtained by simultaneously adding magnesium chloride and titanium chloride to modify the silicon micropowder and graphene in step (2) of the method for preparing the modified filler significantly improves the dust-proof performance of the BOPP double-sided heat-seal film compared to the modified filler obtained by modifying the silicon micropowder and graphene with only magnesium chloride or titanium chloride. In step (2) of the method for preparing the modified filler, the simultaneous addition of magnesium chloride and titanium chloride to modify the silicon micropowder and graphene can synergistically improve the dust-proof performance of the BOPP double-sided heat-seal film.

Claims

1. A BOPP double-sided heat-sealed film comprising a core layer and an outer layer, characterized in that: The material of the core layer is homopolymer polypropylene resin; The material of the outer layer is a polypropylene composition; the polypropylene composition comprises the following components: Homopolymer polypropylene resin 80-120 parts; filler 30-50 parts; lubricant 1-3 parts; antioxidant 0.5-2 parts; The filler is a modified filler, which is prepared by the following method: (1) Take silicon micropowder and graphene, add them to water, and then add ethylenediaminetetramethylenephosphoric acid to obtain a mixed solution; (2) adding a metal salt to the mixed solution, stirring for 2 to 5 hours, separating the solid, and drying the solid to obtain the modified filler; In step (1), the total weight ratio of silicon micropowder and graphene to ethylenediaminetetramethylenephosphoric acid and water is 0.8-1.5 kg:80-150 g:10 L; the weight ratio of silicon micropowder and graphene is 3-5:1; In step (2), the ratio of the mixed solution to the metal salt is 10L:100-200g; The metal salt consists of magnesium chloride and titanium chloride; the weight ratio of magnesium chloride to titanium chloride is 1-3:

1.

2. The BOPP double-sided heat-sealed film according to claim 1, characterized in that: The polypropylene composition comprises the following components: Homopolymer polypropylene resin 90-110 parts; filler 30-40 parts; lubricant 1-2 parts; antioxidant 0.5-1 part.

3. The BOPP double-sided heat-sealed film according to claim 1, characterized in that: In step (1), the total weight of silicon micropowder and graphene to the amount of ethylenediaminetetramethylenephosphoric acid and water is 1kg:100g:10L.

4. The BOPP double-sided heat-sealed film according to claim 1, characterized in that: The weight ratio of silicon micropowder to graphene in step (1) is 4:

1.

5. The BOPP double-sided heat-sealed film according to claim 1, characterized in that: The ratio of the mixed solution to the metal salt in step (2) is 10L:150g.

6. The BOPP double-sided heat-sealed film according to claim 1, characterized in that: The weight ratio of magnesium chloride to titanium chloride is 2:

1.

7. The method for preparing the BOPP double-sided heat-sealable film according to any one of claims 1 to 6, characterized in that: The following steps are included: The core layer material and the outer layer material are melt-extruded through an extruder respectively and then converged into the same die head, and then subjected to sheet casting, longitudinal stretching, transverse stretching, pulling and winding processes to obtain the BOPP double-sided heat-sealed film.