High-strength single-sided polarized BOPP aluminized film and preparation method thereof

Abstract

This invention relates to the field of BOPP film technology, and discloses a high-strength single-sided polar BOPP aluminized film and its preparation method, which is composed of a reinforcing layer, a core layer, a heat-sealing layer and an aluminized layer in sequence; the reinforcing layer is composed of the following raw materials in weight percentage: homopolymer polypropylene 90-95% and anti-adhesion masterbatch I 5-10%; wherein, anti-adhesion masterbatch I includes the following raw materials: ultrafine activated calcium carbonate, stearic acid, and homopolymer polypropylene; the core layer is composed of the following raw materials in weight percentage: homopolymer polypropylene 75-80%, random silica 1-5%, and POE thermoplastic elastomer 15-20%; the heat-sealing layer is composed of the following raw materials in weight percentage: ternary random copolymer polypropylene 60-70% and anti-adhesion masterbatch II 30-40%; wherein, anti-adhesion masterbatch II includes the following raw materials: lecithin, isosorbide, sodium dodecylbenzenesulfonate, and homopolymer polypropylene. The aluminized film of this invention has high polarity, interlayer peel strength and impact resistance, which reduces the production cost of BOPP aluminized film and broadens the application range of BOPP film.

Description

Technical Field

[0001] This invention relates to the field of BOPP film technology, and in particular to a high-strength single-sided polar BOPP aluminized film and its preparation method. Background Technology

[0002] Metallized film is a composite flexible packaging material formed by coating a very thin layer of metallic aluminum onto the surface of a plastic film using a special process. Because it possesses both the characteristics of plastic film and metal, it is an inexpensive, aesthetically pleasing, high-performance, and highly practical packaging material. The aluminum coating on the film surface serves to block light and protect against ultraviolet radiation, extending the shelf life of the contents and increasing the film's brightness. It partially replaces aluminum foil, offering advantages such as low cost, attractive appearance, and good barrier properties. Therefore, metallized film is widely used in composite packaging, currently primarily for packaging dry and puffed foods such as biscuits, as well as for the outer packaging of some pharmaceuticals and cosmetics.

[0003] Materials used for metallization include BOPET, BOPP, and CPP. Polypropylene, as a general-purpose thermoplastic, has many excellent properties. However, due to the material's own differences, BOPP has the following disadvantages compared with other materials: (1) BOPP film is a non-polar material. When used for metallization, it needs to be corona treated first, which increases the production cost; (2) The film itself has poor polarity. Even after corona treatment, the metallization fastness is not as good as BOPET. The peel strength between the metallization layer and the outermost layer of BOPP metallized film is basically ≤0.5N / 15mm, which greatly limits the application and scope of BOPP metallized film; (3) The heat-sealing temperature of the existing BOPP metallized film is relatively high. When used for commodity packaging, oxygen can easily penetrate into the heat-sealed area, resulting in poor oxygen barrier performance; (4) The film has poor impact toughness, especially low-temperature impact strength, which limits its application and development. Summary of the Invention

[0004] To address the technical problems existing in the background art, this invention proposes a high-strength single-sided polar BOPP metallized film and its preparation method. By constructing a polar hierarchical structure, the printing problem caused by the poor polarity of polypropylene-based films is solved. Simultaneously, the presence of the elastomer imparts high impact strength to the film. This invention exhibits high polarity, interlayer peel strength, and impact resistance, reduces the production cost of BOPP metallized films, and broadens the application range of BOPP films.

[0005] The present invention proposes a high-strength single-sided polar BOPP aluminized film, which is composed of a reinforcing layer, a core layer, a heat-sealing layer and an aluminized layer in sequence;

[0006] The reinforcing layer is composed of the following raw materials by weight percentage: 90-95% homopolymer polypropylene and 5-10% anti-sticking masterbatch I; wherein, anti-sticking masterbatch I includes the following raw materials: ultrafine activated calcium carbonate, stearic acid, and homopolymer polypropylene.

[0007] The core layer is composed of the following raw materials by weight percentage: 75-80% homopolymer polypropylene, 1-5% random silica, and 15-20% POE thermoplastic elastomer.

[0008] The heat-sealing layer is composed of the following raw materials by weight percentage: 60-70% ternary random copolymer polypropylene and 30-40% anti-sticking masterbatch II; wherein, anti-sticking masterbatch II includes the following raw materials: lecithin, isosorbide, sodium dodecylbenzenesulfonate, and homopolymer polypropylene.

[0009] Preferably, the anti-sticking masterbatch I comprises the following raw materials by weight percentage: 10-20% ultrafine activated calcium carbonate, 10-20% stearic acid, and 70-80% homopolymer polypropylene.

[0010] Preferably, the ultrafine activated calcium carbonate has a particle size of 190-210 nm, a whiteness greater than 93, and the viscosity of the emulsion is 80-90 mPa·s.

[0011] Preferably, the irregular silica particle size ranges from 2 to 4 μm.

[0012] Preferably, the melt flow index of the POE-type thermoplastic elastomer is 5-10 g / min;

[0013] Preferably, the anti-sticking masterbatch II comprises the following raw materials in weight percentage: 10-20% lecithin, 10-20% isosorbide, 10-20% sodium dodecylbenzenesulfonate, and 50-70% homopolymer polypropylene.

[0014] Preferably, the lecithin has an HLB value of 4-10.

[0015] Preferably, the total thickness of the reinforcing layer, core layer, and heat-sealing layer is 20-40 μm; wherein the thickness percentage of each layer is: reinforcing layer 2-7%, core layer 80-85%, and heat-sealing layer 8-13%.

[0016] This invention also proposes a method for preparing the above-mentioned high-strength single-sided polar BOPP aluminized film, comprising the following steps:

[0017] S1. Preparation of anti-sticking masterbatch I: Stearic acid is dissolved in deionized water at 50-60℃ to form an 8-13wt% stearic acid solution; then ultrafine activated calcium carbonate is added to it and stirred until an emulsion is formed. After filtration and vacuum drying, mixed solid material I is obtained; mixed solid material I and homopolymer polypropylene are fed into a twin-screw extruder for extrusion granulation, cooling, and pelletizing to obtain anti-sticking masterbatch I;

[0018] S2. Preparation of anti-sticking masterbatch II: Sodium dodecylbenzenesulfonate and isosorbide are added to water sequentially and stirred to obtain a mixed solution; lecithin is dissolved in ethanol at 50-60℃ and stirred to obtain a lecithin solution; the lecithin solution is added to the mixed solution, stirred, filtered, and vacuum dried to obtain mixed solid material II; mixed solid material II and homopolymer polypropylene are fed into a twin-screw extruder for extrusion granulation, cooled, and pelletized to obtain anti-sticking masterbatch II;

[0019] S3, Melting: The reinforcing layer material, core layer material and heat-sealing layer material are added to the extruder for melt extrusion to obtain the core layer melt, reinforcing layer melt and heat-sealing layer melt, respectively;

[0020] S4. Pre-film preparation: The reinforcing layer melt, core layer melt, and heat-sealing layer melt are filtered separately and then extruded into a film by converging at the lip of a three-layer die. The film is then attached to a cooling roller with a high-pressure air knife for rapid cooling to form a cast sheet, which is then cooled and shaped by circulating cooling water. The cast sheet is stretched longitudinally to obtain a thick film, and then stretched laterally, heat-shaped, and cooled to obtain the pre-film.

[0021] S5. Preparation of BOPP aluminum-coated film: The surface of the heat-sealing layer of the pre-made film is aluminum-coated to form an aluminum film layer, which is the BOPP aluminum-coated film.

[0022] Preferably, in S2, after adding the lecithin solution to the mixed solution, the HLB of the system is controlled at 10-24.

[0023] In S5, aluminum is plated using vacuum evaporation or plasma plating.

[0024] Beneficial effects: This invention incorporates POE-type thermoplastic elastomers into the core layer and ultrafine activated calcium carbonate into the anti-stick masterbatch of the reinforcing layer, thereby improving the overall strength and impact resistance of the film. The heat-sealing layer uses ternary random copolymer polypropylene, which lowers the heat-sealing temperature and increases the heat-sealing strength. Furthermore, the presence of isosorbide, lecithin, and sodium dodecylbenzenesulfonate in the anti-stick masterbatch of the heat-sealing layer increases the overall polarity of the film and enhances the interlayer peel strength of the aluminized layer. This film can also be adapted to production lines for ordinary BOPP films, broadening the application range of BOPP films. Detailed Implementation

[0025] In the examples below, sodium dodecylbenzenesulfonate (SDBS) has a purity of ≥95%, and the POE thermoplastic elastomer is Dow Chemical's 8003 grade POE, which is food grade.

[0026] The technical solution of the present invention will now be described in detail through specific embodiments.

[0027] Example 1

[0028] A high-strength single-sided polar BOPP aluminized film is composed of a reinforcing layer, a core layer, a heat-sealing layer and an aluminized layer in sequence; wherein the thickness of the reinforcing layer, the core layer and the heat-sealing layer is 28μm, and the thickness percentage of each layer is: 3% for the reinforcing layer, 85% for the core layer and 12% for the heat-sealing layer.

[0029] The reinforcing layer is composed of 90 parts and 10 parts of homopolymer polypropylene by weight; the anti-sticking masterbatch I is composed of 12 parts of ultrafine activated calcium carbonate, 12 parts of stearic acid and 76 parts of homopolymer polypropylene by weight; the ultrafine activated calcium carbonate has a particle size of 195 nm, a whiteness of 93 and a viscosity of 82 mPa·s in the emulsion.

[0030] The core layer is composed of 77 parts by weight of homopolymer polypropylene, 3 parts by weight of random silica and 20 parts by weight of POE thermoplastic elastomer; the random silica has a particle size range of 2 μm and the POE thermoplastic elastomer has a melt index of 6 g / min.

[0031] The heat-sealing layer is composed of 62 parts by weight of ternary random copolymer polypropylene and 38 parts by weight of anti-adhesion masterbatch II; the anti-adhesion masterbatch II is composed of 70 parts by weight of homopolymer polypropylene, 10 parts by weight of lecithin, 10 parts by weight of isosorbide and 10 parts by weight of sodium dodecylbenzenesulfonate; the HLB value of lecithin is 6.

[0032] The preparation method of the above-mentioned high-strength single-sided polar BOPP aluminized film includes the following steps:

[0033] S1. Preparation of anti-sticking masterbatch I: Deionized water was added to a mixing tank and heated to 55°C; stearic acid was dissolved in the 55°C deionized water at a mass concentration of 10% and stirred for 20 minutes. Then, ultrafine activated calcium carbonate was added and stirring was continued until an emulsion was formed. Finally, stirring was stopped and the mixture was filtered. Then, vacuum drying was performed. The anti-sticking masterbatch I and homopolymer polypropylene were fed into a twin-screw extruder for extrusion granulation. The extruded plastic strips were cooled and granulated to produce open-face masterbatch.

[0034] S2. Preparation of anti-sticking masterbatch II: Water is added to the first mixing vessel, followed by the surfactant sodium dodecylbenzenesulfonate, then isosorbide, and stirring begins; ethanol is added to the second mixing vessel and heated to 55°C; lecithin is dissolved in the ethanol at 55°C and stirred for 20 minutes, then poured into the first mixing vessel (mixed liquid HLB is 10), and stirring continues for 20 minutes. After stopping stirring, the mixed liquid is filtered; then vacuum dried; anti-sticking masterbatch II and homopolymer polypropylene are fed into a twin-screw extruder for extrusion granulation; the extruded plastic strips are cooled and granulated to produce open-face masterbatch;

[0035] S3. Add the reinforcing layer material, core layer material and heat-sealing layer material to the extruder for melt extrusion to obtain the core layer melt, reinforcing layer melt and heat-sealing layer melt respectively;

[0036] S4. After filtering the reinforcing layer melt, core layer melt, and heat-sealing layer melt separately, they are extruded together at the lip of a three-layer die to form a film. The film is then attached to a cooling roller using a high-pressure air knife for rapid cooling to form a cast sheet, which is then cooled and shaped using circulating cooling water. The cast sheet is longitudinally stretched to obtain a thick film, followed by transverse stretching, heat setting, and natural cooling to room temperature to obtain a high-strength single-sided polar BOPP aluminized film.

[0037] S5. Aluminum is deposited on the surface of the heat-sealing layer in the BOPP film layer by vacuum evaporation to form an aluminum film layer with a thickness of 30nm.

[0038] Example 2

[0039] A high-strength single-sided polar BOPP aluminized film is composed of a reinforcing layer, a core layer, a heat-sealing layer and an aluminized layer in sequence; wherein the thickness of the reinforcing layer, the core layer and the heat-sealing layer is 30μm, and the thickness percentage of each layer is: 4% for the reinforcing layer, 85% for the core layer and 11% for the heat-sealing layer.

[0040] The reinforcing layer is composed of 92 parts by weight of homopolymer polypropylene and 8 parts by weight of anti-sticking masterbatch I; the anti-sticking masterbatch I is composed of 14 parts by weight of ultrafine activated calcium carbonate, 14 parts by weight of stearic acid and 72 parts by weight of homopolymer polypropylene; the ultrafine activated calcium carbonate has a particle size of 201 nm, a whiteness of 93, and a viscosity of 84 mPa·s in the emulsion liquid.

[0041] The core layer is composed of 78 parts by weight of homopolymer polypropylene, 3 parts of random silica, and 19 parts of POE thermoplastic elastomer; the random silica has a particle size range of 2 μm, and the POE thermoplastic elastomer has a melt index of 6 g / min.

[0042] The heat-sealing layer is composed of 64 parts by weight of ternary random copolymer polypropylene and 36 parts by weight of anti-adhesion masterbatch II; the anti-adhesion masterbatch II is composed of 64 parts by weight of homopolymer polypropylene, 12 parts by weight of lecithin, 12 parts by weight of isosorbide and 12 parts by weight of sodium dodecylbenzenesulfonate; the HLB value of lecithin is 7.

[0043] The preparation method of the above-mentioned high-strength single-sided polar BOPP aluminized film includes the following steps:

[0044] S1. Preparation of anti-sticking masterbatch I: Deionized water was added to a mixing tank and heated to 55°C; stearic acid was dissolved in the 55°C deionized water at a mass concentration of 10% and stirred for 20 minutes. Then, ultrafine activated calcium carbonate was added and stirring was continued until an emulsion was formed. Finally, stirring was stopped and the mixture was filtered. Then, vacuum drying was performed. The anti-sticking masterbatch I and homopolymer polypropylene were fed into a twin-screw extruder for extrusion granulation. The extruded plastic strips were cooled and granulated to produce open-face masterbatch.

[0045] S2. Preparation of anti-sticking masterbatch II: Water is added to the first mixing vessel, followed by the surfactant sodium dodecylbenzenesulfonate, then isosorbide, and stirring begins; ethanol is added to the second mixing vessel and heated to 55°C; lecithin is dissolved in the ethanol at 55°C and stirred for 20 minutes, then poured into the first mixing vessel (mixed liquid HLB is 14), and stirring continues for 20 minutes. After stopping stirring, the mixed liquid is filtered; then vacuum dried; anti-sticking masterbatch II and homopolymer polypropylene are fed into a twin-screw extruder for extrusion granulation; the extruded plastic strips are cooled and granulated to produce open-face masterbatch;

[0046] S3. Add the reinforcing layer material, core layer material and heat-sealing layer material to the extruder for melt extrusion to obtain the core layer melt, reinforcing layer melt and heat-sealing layer melt respectively;

[0047] S4. After filtering the reinforcing layer melt, core layer melt, and heat-sealing layer melt separately, they are extruded together at the lip of a three-layer die to form a film. The film is then attached to a cooling roller using a high-pressure air knife for rapid cooling to form a cast sheet, which is then cooled and shaped using circulating cooling water. The cast sheet is longitudinally stretched to obtain a thick film, followed by transverse stretching, heat setting, and natural cooling to room temperature to obtain a high-strength single-sided polar BOPP aluminized film.

[0048] S5. Aluminum is deposited on the surface of the heat-sealing layer in the BOPP film layer by vacuum evaporation to form an aluminum film layer with a thickness of 30nm.

[0049] Example 3

[0050] A high-strength single-sided polar BOPP aluminized film is composed of a reinforcing layer, a core layer, a heat-sealing layer and an aluminized layer in sequence; wherein the thickness of the reinforcing layer, the core layer and the heat-sealing layer is 32μm, and the thickness percentage of each layer is: 5% for the reinforcing layer, 85% for the core layer and 10% for the heat-sealing layer.

[0051] The reinforcing layer is composed of 93 parts by weight of homopolymer polypropylene and 7 parts by weight of anti-sticking masterbatch I; the anti-sticking masterbatch I is composed of 16 parts by weight of ultrafine activated calcium carbonate, 16 parts by weight of stearic acid and 68 parts by weight of homopolymer polypropylene; the ultrafine activated calcium carbonate has a particle size of 205 nm, a whiteness of 93, and a viscosity of 86 mPa·s in the emulsion.

[0052] The core layer is composed of 79 parts by weight of homopolymer polypropylene, 4 parts of random silica, and 17 parts of POE thermoplastic elastomer; the random silica has a particle size range of 2 μm, and the POE thermoplastic elastomer has a melt index of 7 g / min.

[0053] The heat-sealing layer is composed of 66 parts by weight of ternary random copolymer polypropylene and 34 parts by weight of anti-adhesion masterbatch II; the anti-adhesion masterbatch II is composed of 58 parts by weight of homopolymer polypropylene, 14 parts by weight of lecithin, 14 parts by weight of isosorbide and 14 parts by weight of sodium dodecylbenzenesulfonate; the HLB value of lecithin is 8.

[0054] The preparation method of the above-mentioned high-strength single-sided polar BOPP aluminized film includes the following steps:

[0055] S1. Preparation of anti-sticking masterbatch I: Deionized water was added to a mixing tank and heated to 55°C; stearic acid was dissolved in the 55°C deionized water at a mass concentration of 10% and stirred for 20 minutes. Then, ultrafine activated calcium carbonate was added and stirring was continued until an emulsion was formed. Finally, stirring was stopped and the mixture was filtered. Then, vacuum drying was performed. The anti-sticking masterbatch I and homopolymer polypropylene were fed into a twin-screw extruder for extrusion granulation. The extruded plastic strips were cooled and granulated to produce open-face masterbatch.

[0056] S2. Preparation of anti-sticking masterbatch II: Water is added to the first mixing vessel, followed by the surfactant sodium dodecylbenzenesulfonate, then isosorbide, and stirring begins; ethanol is added to the second mixing vessel and heated to 55°C; lecithin is dissolved in the ethanol at 55°C and stirred for 20 minutes, then poured into the first mixing vessel (mixed liquid HLB is 18), and stirring continues for 20 minutes. After stopping stirring, the mixed liquid is filtered; then vacuum dried; anti-sticking masterbatch II and homopolymer polypropylene are fed into a twin-screw extruder for extrusion granulation; the extruded plastic strips are cooled and granulated to produce open-face masterbatch;

[0057] S3. Add the reinforcing layer material, core layer material and heat-sealing layer material to the extruder for melt extrusion to obtain the core layer melt, reinforcing layer melt and heat-sealing layer melt respectively;

[0058] S4. After filtering the reinforcing layer melt, core layer melt, and heat-sealing layer melt separately, they are extruded together at the lip of a three-layer die to form a film. The film is then attached to a cooling roller using a high-pressure air knife for rapid cooling to form a cast sheet, which is then cooled and shaped using circulating cooling water. The cast sheet is longitudinally stretched to obtain a thick film, followed by transverse stretching, heat setting, and natural cooling to room temperature to obtain a high-strength single-sided polar BOPP aluminized film.

[0059] S5. Aluminum is deposited on the surface of the aluminum layer in the BOPP film layer by plasma plating technology to form an aluminum film layer with a thickness of 30nm.

[0060] Example 4

[0061] A high-strength single-sided polar BOPP aluminized film is composed of a reinforcing layer, a core layer, a heat-sealing layer and an aluminized layer in sequence; wherein the thickness of the reinforcing layer, the core layer and the heat-sealing layer is 34μm, and the thickness percentage of each layer is: 5% for the reinforcing layer, 83% for the core layer and 12% for the heat-sealing layer.

[0062] The reinforcing layer is composed of 94 parts by weight of homopolymer polypropylene and 6 parts by weight of anti-sticking masterbatch I; the anti-sticking masterbatch I is composed of 18 parts by weight of ultrafine activated calcium carbonate, 18 parts by weight of stearic acid and 64 parts by weight of homopolymer polypropylene; the ultrafine activated calcium carbonate has a particle size of 209 nm, a whiteness of 93, and a viscosity of 88 mPa·s in the emulsion liquid.

[0063] The core layer is composed of 80 parts by weight of homopolymer polypropylene, 4 parts of random silica, and 16 parts of POE thermoplastic elastomer; the random silica has a particle size range of 2 μm, and the POE thermoplastic elastomer has a melt index of 7 g / min.

[0064] The heat-sealing layer is composed of 68 parts by weight of ternary random copolymer polypropylene and 32 parts by weight of anti-adhesion masterbatch II; the anti-adhesion masterbatch II is composed of 52 parts by weight of homopolymer polypropylene, 16 parts by weight of lecithin, 16 parts by weight of isosorbide and 16 parts by weight of sodium dodecylbenzenesulfonate; the HLB value of lecithin is 9.

[0065] The preparation method of the above-mentioned high-strength single-sided polar BOPP aluminized film includes the following steps:

[0066] S1. Preparation of anti-sticking masterbatch I: Deionized water was added to a mixing tank and heated to 55°C; stearic acid was dissolved in the 55°C deionized water at a mass concentration of 10% and stirred for 20 minutes. Then, ultrafine activated calcium carbonate was added and stirring was continued until an emulsion was formed. Finally, stirring was stopped and the mixture was filtered. Then, vacuum drying was performed. The anti-sticking masterbatch I and homopolymer polypropylene were fed into a twin-screw extruder for extrusion granulation. The extruded plastic strips were cooled and granulated to produce open-face masterbatch.

[0067] S2. Preparation of anti-sticking masterbatch II: Water is added to the first mixing vessel, followed by the surfactant sodium dodecylbenzenesulfonate, then isosorbide, and stirring begins; ethanol is added to the second mixing vessel and heated to 55°C; lecithin is dissolved in the ethanol at 55°C and stirred for 20 minutes, then poured into the first mixing vessel (mixed liquid HLB is 22), and stirring continues for 20 minutes. After stopping stirring, the mixed liquid is filtered; then vacuum dried; anti-sticking masterbatch II and homopolymer polypropylene are fed into a twin-screw extruder for extrusion granulation; the extruded plastic strips are cooled and granulated to produce open-face masterbatch;

[0068] S3. Add the reinforcing layer material, core layer material and heat-sealing layer material to the extruder for melt extrusion to obtain the core layer melt, reinforcing layer melt and heat-sealing layer melt respectively;

[0069] S4. After filtering the reinforcing layer melt, core layer melt, and heat-sealing layer melt separately, they are extruded together at the lip of a three-layer die to form a film. The film is then attached to a cooling roller using a high-pressure air knife for rapid cooling to form a cast sheet, which is then cooled and shaped using circulating cooling water. The cast sheet is longitudinally stretched to obtain a thick film, followed by transverse stretching, heat setting, and natural cooling to room temperature to obtain a high-strength single-sided polar BOPP aluminized film.

[0070] S5. Aluminum is deposited on the surface of the aluminum layer in the BOPP film layer by plasma plating technology to form an aluminum film layer with a thickness of 30nm.

[0071] The samples obtained in Examples 1-4 above were subjected to performance tests, and the test methods were as follows: peel strength GB / T10003, impact strength GB / T 9639, and oxygen permeability GB / T 19789. The test results are shown in the table below:

[0072]

[0073] As can be seen from the table above, Examples 1-4 have good impact resistance, peel strength and low oxygen permeability. At the same time, the production of this film reduces the production cost of BOPP metallized film, broadens the application range of BOPP film and has broad application prospects.

[0074] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-strength single-sided polar BOPP aluminized film, characterized in that, It consists of a reinforcement layer, a core layer, a heat-sealing layer, and an aluminum-plated layer in sequence; The reinforcing layer is composed of the following raw materials by weight percentage: 90-95% homopolymer polypropylene and 5-10% anti-sticking masterbatch I; wherein, anti-sticking masterbatch I includes the following raw materials: ultrafine activated calcium carbonate, stearic acid, and homopolymer polypropylene; The core layer is composed of the following raw materials by weight percentage: 75-80% homopolymer polypropylene, 1-5% random silica, and 15-20% POE-type thermoplastic elastomer; The heat-sealing layer is composed of the following raw materials by weight percentage: 60-70% ternary random copolymer polypropylene and 30-40% anti-sticking masterbatch II; wherein, anti-sticking masterbatch II includes the following raw materials: lecithin, isosorbide, sodium dodecylbenzenesulfonate, and homopolymer polypropylene.

2. The high-strength single-sided polar BOPP aluminized film according to claim 1, characterized in that, The anti-sticking masterbatch I comprises the following raw materials by weight percentage: 10-20% ultrafine activated calcium carbonate, 10-20% stearic acid, and 70-80% homopolymer polypropylene.

3. The high-strength single-sided polar BOPP aluminized film according to claim 1, characterized in that, The ultrafine activated calcium carbonate has a particle size of 190-210 nm and a whiteness greater than 93. The stearic acid is dissolved in deionized water at 50-60°C to form an 8-13 wt% stearic acid solution. Then, the ultrafine activated calcium carbonate is added to the solution and stirred until an emulsion is formed. The viscosity of the emulsion is 80-90 mPa·s.

4. The high-strength single-sided polar BOPP aluminized film according to claim 1, characterized in that, The irregular silica particles have a particle size range of 2-4 μm.

5. The high-strength single-sided polar BOPP aluminized film according to claim 1, characterized in that, The melt flow index of the POE-type thermoplastic elastomer is 5-10 g / min.

6. The high-strength single-sided polar BOPP aluminized film according to claim 1, characterized in that, The anti-sticking masterbatch II comprises the following raw materials by weight percentage: 10-20% lecithin, 10-20% isosorbide, 10-20% sodium dodecylbenzenesulfonate, and 50-70% homopolymer polypropylene.

7. The high-strength single-sided polar BOPP aluminized film according to claim 1, characterized in that, The lecithin has an HLB value of 4-10; the sodium dodecylbenzenesulfonate has a purity of ≥95%.

8. The high-strength single-sided polar BOPP aluminized film according to claim 1, characterized in that, The total thickness of the reinforcing layer, core layer and heat-sealing layer is 20-40 μm; wherein the thickness percentage of each layer is: reinforcing layer 2-7%, core layer 80-85%, heat-sealing layer 8-13%.

9. A method for preparing a high-strength single-sided polar BOPP aluminized film as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Preparation of anti-sticking masterbatch I: Stearic acid is dissolved in deionized water at 50-60℃ to form an 8-13wt% stearic acid solution; then ultrafine activated calcium carbonate is added to it and stirred until an emulsion is formed. After filtration and vacuum drying, mixed solid material I is obtained; mixed solid material I and homopolymer polypropylene are fed into a twin-screw extruder for extrusion granulation, cooling and pelletizing to obtain anti-sticking masterbatch I. S2, Preparation of anti-adhesion masterbatch II: Sodium dodecylbenzenesulfonate and isosorbide are added to water in sequence and stirred to obtain a mixed solution; lecithin is dissolved in ethanol at 50-60℃ and stirred to obtain a lecithin solution; Lecithin solution was added to the mixed solution, stirred, filtered, and vacuum dried to obtain mixed solid material II; mixed solid material II and homopolymer polypropylene were fed into a twin-screw extruder for extrusion granulation, cooled, and pelletized to obtain anti-sticking masterbatch II; S3, Melting: The reinforcing layer material, core layer material and heat-sealing layer material are added to the extruder for melt extrusion to obtain the core layer melt, reinforcing layer melt and heat-sealing layer melt, respectively; S4. Pre-film preparation: The reinforcing layer melt, core layer melt, and heat-sealing layer melt are filtered separately and then extruded into a film by converging at the lip of a three-layer die. The film is then attached to a cooling roller with a high-pressure air knife for rapid cooling to form a cast sheet, which is then cooled and shaped by circulating cooling water. The cast sheet is stretched longitudinally to obtain a thick film, and then stretched laterally, heat-shaped, and cooled to obtain the pre-film. S5. Preparation of BOPP aluminum-coated film: The surface of the heat-sealing layer of the pre-made film is aluminum-coated to form an aluminum film layer, which is the BOPP aluminum-coated film.

10. The method for preparing a high-strength single-sided polar BOPP aluminized film according to claim 9, characterized in that, In S2, after adding the lecithin solution to the mixed solution, the HLB of the system is controlled at 10-24. In S5, aluminum is plated using vacuum evaporation or plasma plating.

Images