Pearl label film and preparation method thereof

Abstract

The invention discloses a pearl label film and a preparation method thereof, and relates to the technical field of film materials. The pearl label film is a BOPP film of a five-layer structure and sequentially comprises an upper surface layer, a secondary upper surface layer, a core layer, a secondary lower surface layer and a lower surface layer, raw materials of the upper surface layer comprise a matting material, raw materials of the secondary upper surface layer comprise polypropylene and whitening master batch, raw materials of the core layer comprise polypropylene, pearlescent master batch and an antistatic agent, raw materials of the secondary lower surface layer comprise polypropylene, and raw materials of the lower surface layer comprise polypropylene. The raw materials of the lower surface layer comprise polypropylene and an anti-adhesion master batch. The pearl label film provided by the invention has excellent mechanical properties and appearance effect, is not easy to wrinkle, and has good processing performance and use performance.

Description

Technical Field

[0001] The invention relates to the technical field of film materials, and in particular to a pearl label film and a preparation method thereof. Background Art

[0002] BOPP pearl label film is a surface printable film product with soft pearl luster, high hiding power and good flatness, which is widely used in the packaging of cosmetics, food and beverages. In order to achieve a soft pearlescent appearance, not only does the BOPP pearl label film need to have multiple functional layers for compounding, but also additives such as pearlescent agents and brighteners need to be added to each functional layer according to actual needs. The use of these additives affects the uniformity of the components of each functional layer, making the film material uneven, which not only affects the appearance effects such as the haze and gloss of the film, but also causes the BOPP pearl label film to wrinkle easily during the actual processing and use, thereby affecting the product yield and product quality. Summary of the invention

[0003] Based on the technical problems existing in the background technology, the present invention proposes a pearl label film which has excellent mechanical properties and appearance effects and is not easy to wrinkle, and a preparation method thereof.

[0004] The present invention provides a pearl label film, which is a BOPP film with a five-layer structure, which includes an upper surface layer, a sub-upper surface layer, a core layer, a sub-lower surface layer and a lower surface layer in sequence;

[0005] The raw material of the upper surface layer includes matte material;

[0006] The raw materials of the secondary upper surface layer include 80-90 parts of polypropylene and 10-20 parts of whitening masterbatch by weight; the raw materials of the whitening masterbatch include 60-80 parts of polypropylene, 20-40 parts of octadecylamine-modified titanium dioxide, 1-2 parts of dispersant, and 0.5-1 part of antioxidant by weight;

[0007] The raw materials of the core layer include 70-85 parts of polypropylene, 15-30 parts of pearlescent masterbatch and 0.5-2 parts of antistatic agent by weight; the raw materials of the pearlescent masterbatch include 60-80 parts of polypropylene, 20-40 parts of modified calcium carbonate, 1-2 parts of dispersant and 0.5-1 part of antioxidant by weight;

[0008] The material of the sub-lower surface layer includes polypropylene;

[0009] The raw materials of the lower surface layer include 80 to 90 parts of polypropylene and 10 to 20 parts of anti-adhesion masterbatch by mass.

[0010] Preferably, the preparation method of the octadecylamine-modified titanium dioxide comprises: adding titanium dioxide to a silane coupling agent KH-560 solution and dispersing it evenly, stirring and reacting it at 40 to 80° C. for 2 to 6 hours, then centrifuging, washing, and drying to obtain powder A; adding the powder A to an ethanol solution of octadecylamine and dispersing it evenly, stirring and reacting it at 40 to 60° C. for 5 to 12 hours, then centrifuging, washing, and drying to obtain powder A.

[0011] Preferably, the mass ratio of the titanium dioxide to the silane coupling agent KH-560 is 1:1-3.

[0012] Preferably, the mass ratio of the powder A to octadecylamine is 1:1-10.

[0013] Preferably, the preparation method of the octadecylamine-modified calcium carbonate comprises: adding calcium carbonate to a silane coupling agent KH-560 solution and dispersing the mixture evenly, stirring the mixture at 40 to 80° C. for reaction for 2 to 6 hours, centrifuging, washing, and drying to obtain powder B; adding the powder B to an ethanol solution of octadecylamine and dispersing the mixture evenly, stirring the mixture at 40 to 60° C. for reaction for 5 to 12 hours, centrifuging, washing, and drying to obtain the powder B.

[0014] Preferably, the mass ratio of the calcium carbonate to the silane coupling agent KH-560 is 1:1-3.

[0015] Preferably, the mass ratio of the powder B to octadecylamine is 1:1-10.

[0016] Preferably, the ethanol solution of octadecylamine is obtained by dissolving octadecylamine in anhydrous ethanol.

[0017] Preferably, the concentration of the ethanol solution of octadecylamine is 5 to 20 g / L.

[0018] Preferably, the silane coupling agent KH-560 solution is obtained by mixing the silane coupling agent KH-560, anhydrous ethanol and water in a mass ratio of 1:5 to 10:3 to 5.

[0019] Preferably, the raw materials of the anti-adhesive masterbatch include 90-95 parts of polypropylene, 5-10 parts of glass microspheres, 0.5-1 part of dispersant, and 0.2-1 part of antioxidant in parts by mass; the particle size of the glass microspheres is 3-5 μm.

[0020] Preferably, the dispersant is at least one of stearic acid, sodium stearate, calcium stearate and erucamide; and the antioxidant is antioxidant 1010, antioxidant 168 or a combination thereof.

[0021] Preferably, the total thickness of the pearl label film is 35-55 μm, the thickness of the upper surface layer is 2-3 μm, the thickness of the sub-upper surface layer is 5-8 μm, the thickness of the core layer is 15-35 μm, the thickness of the sub-lower surface layer is 5-7 μm, and the thickness of the lower surface layer is 1-2 μm.

[0022] The present invention also discloses a method for preparing the pearl label film, comprising the following steps:

[0023] S1, respectively melt-extrude the raw materials of the upper surface layer, the sub-upper surface layer, the core layer, the sub-lower surface layer and the lower surface layer to obtain the upper surface layer melt, the sub-upper surface layer melt, the core layer melt, the sub-lower surface layer melt and the lower surface layer melt, co-extrude through a five-layer structure die head, and cool with a chilled roller to obtain a thick sheet;

[0024] S2, sequentially stretching the thick sheet longitudinally and transversely, and then cooling and winding it to obtain a pearl label film.

[0025] Preferably, in S1, the temperature of melt extrusion is 220-230°C.

[0026] Preferably, in S1, the cooling temperature is 30-35°C.

[0027] Preferably, in S2, the stretching temperature for longitudinal stretching is 110-130°C, and the stretching ratio is 5-6; the stretching temperature for transverse stretching is 160-180°C, and the stretching ratio is 8-9.

[0028] The beneficial effects of the present invention are as follows:

[0029] The five-layer pearl label film prepared by the present invention respectively adds a whitening agent and pearl powder to the second upper surface layer and the core layer, and modifies the titanium dioxide as a whitening agent and the calcium carbonate as a pearl powder, first grafting the epoxy silane coupling agent KH-560 on the surface, and then grafting octadecylamine to the powder surface through the action between the amino group and the epoxy group, so as to graft a long aliphatic chain with good flexibility on the powder surface, which can improve the dispersibility of titanium dioxide and calcium carbonate in the functional layer, thereby improving the uniformity of the composition of the functional layer of the film, and can also improve the flexibility of the film, thereby effectively improving the wrinkling phenomenon of the film during processing and use. The pearl label film of the present invention has both excellent mechanical properties and appearance effects, is not easy to wrinkle, and has good processing performance and use performance. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is described in detail below through specific embodiments.

[0031] In the following examples and comparative examples: the polypropylene is Sinopec F280; the matting material is Deguan D6612 matting masterbatch; the antistatic agent is Clariant FA68; the dispersant is stearic acid; and the antioxidant is antioxidant 1010.

[0032] Example 1

[0033] A pearl label film, which is a five-layer BOPP film, which includes an upper surface layer, a sub-upper surface layer, a core layer, a sub-lower surface layer and a lower surface layer in sequence;

[0034] The raw material of the upper surface layer is matte material;

[0035] The raw materials of the second upper surface layer are composed of 85 parts of polypropylene and 15 parts of whitening masterbatch by weight; the raw materials of the whitening masterbatch are composed of 70 parts of polypropylene, 30 parts of octadecylamine-modified titanium dioxide, 1.5 parts of dispersant, and 0.5 parts of antioxidant by weight;

[0036] The preparation method of octadecylamine modified titanium dioxide is as follows: adding titanium dioxide to a silane coupling agent KH-560 solution and dispersing the mixture uniformly, stirring the mixture for reaction at 50°C for 3 hours, and then centrifuging, washing, and drying the mixture to obtain powder A; adding powder A to an ethanol solution of octadecylamine with a concentration of 10 g / L and dispersing the mixture uniformly, stirring the mixture for reaction at 50°C for 10 hours, and then centrifuging, washing, and drying the mixture to obtain titanium dioxide modified titanium dioxide, wherein the mass ratio of titanium dioxide to the silane coupling agent KH-560 is 1:2, the mass ratio of powder A to octadecylamine is 1:3, and the silane coupling agent KH-560 solution is obtained by mixing the silane coupling agent KH-560, anhydrous ethanol, and water in a mass ratio of 1:6:4;

[0037] The raw materials of the core layer are composed of 80 parts of polypropylene, 20 parts of pearlescent masterbatch and 1 part of antistatic agent by weight; the raw materials of the pearlescent masterbatch are composed of 70 parts of polypropylene, 30 parts of octadecylamine-modified calcium carbonate, 1.5 parts of dispersant and 0.5 parts of antioxidant by weight;

[0038] The preparation method of octadecylamine modified calcium carbonate is as follows: adding calcium carbonate to a silane coupling agent KH-560 solution and dispersing the mixture uniformly, stirring the mixture for reaction at 50°C for 3 hours, and then centrifuging, washing, and drying the mixture to obtain powder B; adding the powder B to an ethanol solution of octadecylamine with a concentration of 10 g / L and dispersing the mixture uniformly, stirring the mixture for reaction at 50°C for 10 hours, and then centrifuging, washing, and drying the mixture to obtain calcium carbonate modified with octadecylamine, wherein the mass ratio of calcium carbonate to the silane coupling agent KH-560 is 1:2, the mass ratio of powder B to the octadecylamine is 1:3, and the silane coupling agent KH-560 solution is obtained by mixing the silane coupling agent KH-560, anhydrous ethanol, and water in a mass ratio of 1:6:4;

[0039] The material of the second lower surface layer is polypropylene;

[0040] The raw materials of the lower surface layer are composed of 85 parts of polypropylene and 15 parts of anti-adhesion masterbatch by mass; the raw materials of the anti-adhesion masterbatch are composed of 92 parts of polypropylene, 8 parts of glass beads, 0.5 parts of dispersant, and 0.5 parts of antioxidant by mass, wherein the particle size of the glass beads is 3 to 5 μm.

[0041] The total thickness of the pearl label film is 46 μm, the thickness of the upper surface layer is 2.5 μm, the thickness of the second upper surface layer is 6 μm, the thickness of the core layer is 30 μm, the thickness of the second lower surface layer is 6 μm, and the thickness of the lower surface layer is 1.5 μm.

[0042] The method for preparing the pearl label film comprises the following steps:

[0043] S1, respectively melt-extrude the raw materials of the upper surface layer, the sub-upper surface layer, the core layer, the sub-lower surface layer and the lower surface layer at 220-230° C. to obtain an upper surface layer melt, a sub-upper surface layer melt, a core layer melt, a sub-lower surface layer melt and a lower surface layer melt, co-extrude through a five-layer structure die head, and cool with a chilled roller at 30-35° C. to obtain a thick sheet;

[0044] S2. The thick sheet is sequentially stretched longitudinally and transversely, and then cooled and rolled up to obtain a pearl label film; the stretching temperature of the longitudinal stretching is 110-130° C., and the stretching ratio is 6; the stretching temperature of the transverse stretching is 160-180° C., and the stretching ratio is 9.

[0045] Example 2

[0046] A pearl label film, which is a five-layer BOPP film, which includes an upper surface layer, a sub-upper surface layer, a core layer, a sub-lower surface layer and a lower surface layer in sequence;

[0047] The raw material of the upper surface layer is matte material;

[0048] The raw materials of the second upper surface layer are composed of 80 parts of polypropylene and 20 parts of whitening masterbatch by mass; the raw materials of the whitening masterbatch are composed of 60 parts of polypropylene, 40 parts of octadecylamine-modified titanium dioxide, 1 part of dispersant, and 0.5 part of antioxidant by mass;

[0049] The preparation method of octadecylamine modified titanium dioxide is as follows: adding titanium dioxide to a silane coupling agent KH-560 solution and dispersing the mixture uniformly, stirring the mixture for reaction at 40°C for 2 hours, and then centrifuging, washing, and drying the mixture to obtain powder A; adding powder A to an ethanol solution of octadecylamine with a concentration of 5 g / L and dispersing the mixture uniformly, stirring the mixture for reaction at 40°C for 5 hours, and then centrifuging, washing, and drying the mixture to obtain titanium dioxide modified titanium dioxide, wherein the mass ratio of titanium dioxide to the silane coupling agent KH-560 is 1:1, the mass ratio of powder A to octadecylamine is 1:1, and the silane coupling agent KH-560 solution is obtained by mixing the silane coupling agent KH-560, anhydrous ethanol, and water in a mass ratio of 1:5:3;

[0050] The raw materials of the core layer are composed of 70 parts of polypropylene, 30 parts of pearlescent masterbatch and 0.5 parts of antistatic agent by weight; the raw materials of the pearlescent masterbatch are composed of 60 parts of polypropylene, 40 parts of octadecylamine-modified calcium carbonate, 1 part of dispersant and 0.5 parts of antioxidant by weight;

[0051] The preparation method of octadecylamine modified calcium carbonate is as follows: adding calcium carbonate to a silane coupling agent KH-560 solution and dispersing the mixture uniformly, stirring the mixture at 40°C for reaction for 2 hours, and then centrifuging, washing, and drying the mixture to obtain powder B; adding powder B to an ethanol solution of octadecylamine with a concentration of 5 g / L and dispersing the mixture uniformly, stirring the mixture at 40°C for reaction for 5 hours, and then centrifuging, washing, and drying the mixture to obtain calcium carbonate modified with octadecylamine, wherein the mass ratio of calcium carbonate to the silane coupling agent KH-560 is 1:1, the mass ratio of powder B to the octadecylamine is 1:1, and the silane coupling agent KH-560 solution is obtained by mixing the silane coupling agent KH-560, anhydrous ethanol, and water in a mass ratio of 1:5:3;

[0052] The material of the second lower surface layer is polypropylene;

[0053] The raw materials of the lower surface layer are composed of 80 parts of polypropylene and 20 parts of anti-adhesion masterbatch by mass; the raw materials of the anti-adhesion masterbatch are composed of 90 parts of polypropylene, 10 parts of glass beads, 0.5 parts of dispersant, and 0.2 parts of antioxidant by mass, wherein the particle size of the glass beads is 3 to 5 μm.

[0054] The total thickness of the pearl label film is 46 μm, the thickness of the upper surface layer is 2.5 μm, the thickness of the second upper surface layer is 6 μm, the thickness of the core layer is 30 μm, the thickness of the second lower surface layer is 6 μm, and the thickness of the lower surface layer is 1.5 μm.

[0055] The preparation method of the pearl label film is the same as that of Example 1.

[0056] Example 3

[0057] A pearl label film, which is a five-layer BOPP film, which includes an upper surface layer, a sub-upper surface layer, a core layer, a sub-lower surface layer and a lower surface layer in sequence;

[0058] The raw material of the upper surface layer is matte material;

[0059] The raw materials of the second upper surface layer are composed of 90 parts of polypropylene and 10 parts of whitening masterbatch by weight; the raw materials of the whitening masterbatch are composed of 80 parts of polypropylene, 20 parts of octadecylamine-modified titanium dioxide, 2 parts of dispersant, and 1 part of antioxidant by weight;

[0060] The preparation method of octadecylamine modified titanium dioxide is as follows: adding titanium dioxide to a silane coupling agent KH-560 solution and dispersing the mixture uniformly, stirring the mixture for reaction at 80°C for 6 hours, and then centrifuging, washing, and drying the mixture to obtain powder A; adding powder A to an ethanol solution of octadecylamine with a concentration of 20 g / L and dispersing the mixture uniformly, stirring the mixture for reaction at 60°C for 12 hours, and then centrifuging, washing, and drying the mixture to obtain titanium dioxide modified titanium dioxide, wherein the mass ratio of titanium dioxide to the silane coupling agent KH-560 is 1:3, the mass ratio of powder A to octadecylamine is 1:10, and the silane coupling agent KH-560 solution is obtained by mixing the silane coupling agent KH-560, anhydrous ethanol, and water in a mass ratio of 1:10:5;

[0061] The raw materials of the core layer are composed of 85 parts of polypropylene, 15 parts of pearlescent masterbatch and 2 parts of antistatic agent by weight; the raw materials of the pearlescent masterbatch are composed of 80 parts of polypropylene, 20 parts of octadecylamine-modified calcium carbonate, 2 parts of dispersant and 1 part of antioxidant by weight;

[0062] The preparation method of octadecylamine modified calcium carbonate is as follows: adding calcium carbonate to a silane coupling agent KH-560 solution and dispersing the mixture uniformly, stirring the mixture at 80°C for reaction for 6 hours, and then centrifuging, washing, and drying the mixture to obtain powder B; adding powder B to an ethanol solution of octadecylamine with a concentration of 20 g / L and dispersing the mixture uniformly, stirring the mixture at 60°C for reaction for 12 hours, and then centrifuging, washing, and drying the mixture to obtain calcium carbonate modified with octadecylamine, wherein the mass ratio of calcium carbonate to the silane coupling agent KH-560 is 1:3, the mass ratio of powder B to the octadecylamine is 1:10, and the silane coupling agent KH-560 solution is obtained by mixing the silane coupling agent KH-560, anhydrous ethanol, and water at a mass ratio of 1:10:5;

[0063] The material of the second lower surface layer is polypropylene;

[0064] The raw materials of the lower surface layer are composed of 90 parts of polypropylene and 10 parts of anti-adhesion masterbatch by mass; the raw materials of the anti-adhesion masterbatch are composed of 95 parts of polypropylene, 5 parts of glass beads, 1 part of dispersant, and 1 part of antioxidant by mass, wherein the particle size of the glass beads is 3 to 5 μm.

[0065] The total thickness of the pearl label film is 46 μm, the thickness of the upper surface layer is 2.5 μm, the thickness of the second upper surface layer is 6 μm, the thickness of the core layer is 30 μm, the thickness of the second lower surface layer is 6 μm, and the thickness of the lower surface layer is 1.5 μm.

[0066] The preparation method of the pearl label film is the same as that of Example 1.

[0067] Comparative Example 1

[0068] A pearl label film, which is a five-layer BOPP film, which includes an upper surface layer, a sub-upper surface layer, a core layer, a sub-lower surface layer and a lower surface layer in sequence;

[0069] The raw material of the upper surface layer is matte material;

[0070] The raw materials of the secondary upper surface layer are composed of 85 parts of polypropylene and 15 parts of whitening masterbatch by weight; the raw materials of the whitening masterbatch are composed of 70 parts of polypropylene, 30 parts of silane coupling agent KH-560 modified titanium dioxide, 1.5 parts of dispersant, and 0.5 parts of antioxidant by weight;

[0071] The preparation method of silane coupling agent KH-560 modified titanium dioxide is as follows: adding titanium dioxide into a silane coupling agent KH-560 solution and dispersing the mixture uniformly, stirring the mixture for reaction at 50° C. for 3 hours, and then centrifuging, washing, and drying the mixture to obtain a titanium dioxide modified titanium dioxide, wherein the mass ratio of titanium dioxide to the silane coupling agent KH-560 is 1:2, and the silane coupling agent KH-560 solution is obtained by mixing the silane coupling agent KH-560, anhydrous ethanol, and water in a mass ratio of 1:6:4;

[0072] The raw materials of the core layer are composed of 80 parts of polypropylene, 20 parts of pearlescent masterbatch and 1 part of antistatic agent by weight; the raw materials of the pearlescent masterbatch are composed of 70 parts of polypropylene, 30 parts of silane coupling agent KH-560 modified calcium carbonate, 1.5 parts of dispersant and 0.5 parts of antioxidant by weight;

[0073] The preparation method of silane coupling agent KH-560 modified calcium carbonate is as follows: adding calcium carbonate to a silane coupling agent KH-560 solution and dispersing the mixture uniformly, stirring the mixture for reaction at 50° C. for 3 hours, and then centrifuging, washing, and drying the mixture to obtain calcium carbonate, wherein the mass ratio of calcium carbonate to the silane coupling agent KH-560 is 1:2, and the silane coupling agent KH-560 solution is obtained by mixing the silane coupling agent KH-560, anhydrous ethanol, and water in a mass ratio of 1:6:4;

[0074] The material of the second lower surface layer is polypropylene;

[0075] The raw materials of the lower surface layer are composed of 85 parts of polypropylene and 15 parts of anti-adhesion masterbatch by mass; the raw materials of the anti-adhesion masterbatch are composed of 92 parts of polypropylene, 8 parts of glass beads, 0.5 parts of dispersant, and 0.5 parts of antioxidant by mass, wherein the particle size of the glass beads is 3 to 5 μm.

[0076] The total thickness of the pearl label film is 46 μm, the thickness of the upper surface layer is 2.5 μm, the thickness of the second upper surface layer is 6 μm, the thickness of the core layer is 30 μm, the thickness of the second lower surface layer is 6 μm, and the thickness of the lower surface layer is 1.5 μm.

[0077] The preparation method of the pearl label film is the same as that of Example 1.

[0078] Test example

[0079] The wrinkle length of the rolled pearl label film in Example 1 and Comparative Example 1 was tested (the length of the film roll was 6000 m), and the performance of the pearl label films prepared in Example 1 and Comparative Example 1 was tested, wherein the tensile strength test was in accordance with GB / T1040.3-2006, and the haze test was in accordance with GB / T 2410-2008. The test results are shown in Table 1:

[0080] Table 1

[0081]

[0082]

[0083] As can be seen from Table 1, the pearl label films prepared in Examples 1 to 3 have both excellent mechanical properties and appearance effects, and are not easy to wrinkle, and can significantly improve the yield rate and product quality of the film. This is because in Examples 1 to 3, the whitening agent and pearl powder are added to the second upper surface layer and the core layer, respectively, and the titanium dioxide as the whitening agent and the calcium carbonate as the pearl powder are modified, firstly the epoxy silane coupling agent KH-560 is grafted on the surface, and then the octadecylamine is grafted to the powder surface through the action between the amino group and the epoxy group, thereby The surface of the body is grafted with a long aliphatic chain with good flexibility, which can not only improve the dispersion of titanium dioxide and calcium carbonate in the functional layer, thereby improving the composition uniformity of the functional layer of the film, but also enhance the flexibility of the film, thereby effectively improving the wrinkling phenomenon of the film during processing and use; while in Comparative Example 1, epoxy silane coupling agent KH-560 is grafted on the surface of titanium dioxide and calcium carbonate. Although it can improve the compatibility between the powder and the film substrate, the effect of improving flexibility is not good, and the wrinkling phenomenon is much more serious than that of the films of Examples 1 to 3.

[0084] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A pearl label film, characterized in that: The pearl label film is a five-layer BOPP film, which includes an upper surface layer, a sub-upper surface layer, a core layer, a sub-lower surface layer and a lower surface layer in sequence; The raw material of the upper surface layer includes matte material; The raw materials of the secondary upper surface layer include 80-90 parts of polypropylene and 10-20 parts of whitening masterbatch by weight; the raw materials of the whitening masterbatch include 60-80 parts of polypropylene, 20-40 parts of octadecylamine-modified titanium dioxide, 1-2 parts of dispersant, and 0.5-1 part of antioxidant by weight; The raw materials of the core layer include 70-85 parts of polypropylene, 15-30 parts of pearlescent masterbatch and 0.5-2 parts of antistatic agent by weight; the raw materials of the pearlescent masterbatch include 60-80 parts of polypropylene, 20-40 parts of octadecylamine-modified calcium carbonate, 1-2 parts of dispersant and 0.5-1 parts of antioxidant by weight; The material of the sub-lower surface layer includes polypropylene; The raw materials of the lower surface layer include 80 to 90 parts of polypropylene and 10 to 20 parts of anti-adhesion masterbatch by mass.

2. The pearl label film according to claim 1, characterized in that: The preparation method of the octadecylamine-modified titanium dioxide comprises: adding titanium dioxide to a silane coupling agent KH-560 solution and dispersing the titanium dioxide uniformly, stirring the reaction at 40 to 80°C for 2 to 6 hours, and then centrifuging, washing, and drying to obtain powder A; adding the powder A to an ethanol solution of octadecylamine and dispersing the powder uniformly, stirring the reaction at 40 to 60°C for 5 to 12 hours, and then centrifuging, washing, and drying to obtain the powder.

3. The pearl label film according to claim 2, characterized in that: The mass ratio of the titanium dioxide to the silane coupling agent KH-560 is 1:1-3; the mass ratio of the powder A to octadecylamine is 1:1-10.

4. The pearl label film according to claim 1, characterized in that: The preparation method of octadecylamine-modified calcium carbonate comprises: adding calcium carbonate to a silane coupling agent KH-560 solution and dispersing the mixture uniformly, stirring the mixture at 40 to 80°C for reaction for 2 to 6 hours, centrifuging, washing and drying the mixture to obtain powder B; adding the powder B to an ethanol solution of octadecylamine and dispersing the mixture uniformly, stirring the mixture at 40 to 60°C for reaction for 5 to 12 hours, centrifuging, washing and drying the mixture to obtain the calcium carbonate.

5. The pearl label film according to claim 4, characterized in that: The mass ratio of the calcium carbonate to the silane coupling agent KH-560 is 1:1-3; the mass ratio of the powder B to octadecylamine is 1:1-10.

6. The pearl label film according to claim 1, characterized in that: The raw materials of the anti-adhesion masterbatch include 90-95 parts of polypropylene, 5-10 parts of glass microspheres, 0.5-1 part of dispersant, and 0.2-1 part of antioxidant by weight; the particle size of the glass microspheres is 3-5 μm.

7. The pearl label film according to claim 1, characterized in that: The dispersant is at least one of stearic acid, sodium stearate, calcium stearate and erucamide; the antioxidant is antioxidant 1010, antioxidant 168 or a combination thereof.

8. The pearl label film according to claim 1, characterized in that: The total thickness of the pearl label film is 35-55 μm, the thickness of the upper surface layer is 2-3 μm, the thickness of the second upper surface layer is 5-8 μm, the thickness of the core layer is 15-35 μm, the thickness of the second lower surface layer is 5-7 μm, and the thickness of the lower surface layer is 1-2 μm.

9. A method for preparing a pearl label film according to any one of claims 1 to 8, characterized in that: The steps include: S1, respectively melt-extrude the raw materials of the upper surface layer, the sub-upper surface layer, the core layer, the sub-lower surface layer and the lower surface layer to obtain the upper surface layer melt, the sub-upper surface layer melt, the core layer melt, the sub-lower surface layer melt and the lower surface layer melt, co-extrude through a five-layer structure die head, and cool with a chilled roller to obtain a thick sheet; S2, sequentially stretching the thick sheet longitudinally and transversely, and then cooling and winding it to obtain a pearl label film.

10. The method for preparing a pearl label film according to claim 7, characterized in that: In S1, the temperature of melt extrusion is 220-230°C; In S1, the cooling temperature is 30-35°C; In S2, the stretching temperature for longitudinal stretching is 110-130°C, and the stretching ratio is 5-6; the stretching temperature for transverse stretching is 160-180°C, and the stretching ratio is 8-9.

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