Toughened polypropylene film as well as preparation method and application thereof

Abstract

The invention relates to a toughened polypropylene film, a preparation method and application, the toughened polypropylene film comprises a first layer, a second layer and a third layer, the first layer is made of polypropylene; the second layer is prepared from polypropylene, a toughening agent, an antioxidant, a nano filler, a dispersing agent, a fluorosilicone modifier and color master batch; the third layer is prepared from polypropylene, a toughening agent, an antioxidant, a dispersing agent and color masterbatch. The preparation method has the advantages that through the synergistic effect of a core-shell rubber / nano organic montmorillonite hybrid system and a maleic anhydride grafted SEBS / hyperbranched polyester elastomer composite system and a gradient annealing post-treatment process, the tensile property, tear resistance and temperature resistance of the film are remarkably improved, so that the film is more suitable for a complex use environment of a building waterproof roll; the optimized formula design ensures the melt fluidity and the stretching orientation performance of the film in the processing process, and the production efficiency is improved; all the auxiliary agents are environment-friendly materials, and the requirement of green development is met.

Description

Technical Field

[0001] The present invention relates to the technical field of high-toughness films, and in particular, to a toughened polypropylene film, a preparation method and an application thereof. Background Art

[0002] Polypropylene (PP) films are widely used in packaging, construction, electronics and other fields due to their excellent physical properties, chemical stability and low cost. However, traditional polypropylene films have certain limitations in terms of toughness. Especially in the application of the release film base film for building waterproofing membranes, due to the complex construction environment and harsh use conditions (such as high temperature, low temperature, humidity, etc.), ordinary polypropylene films are prone to problems such as brittle cracking and tearing, affecting their service life and reliability.

[0003] At present, there are already some modified polypropylene film products on the market. For example, the toughness of the film is improved by adding elastomers (such as SEBS, TPU, etc.) or inorganic fillers (such as talcum powder, calcium carbonate, etc.). However, these products generally have the following problems:

[0004] 1. Limited toughness improvement: It is difficult to significantly improve the impact resistance and elongation at break of the film by simply relying on the modification methods of elastomers or inorganic fillers;

[0005] 2. Difficult processing: Some modification formulas will cause a decrease in the melt fluidity during the film processing, affecting the production efficiency.

[0006] At present, in view of the problems in the related technologies, such as less toughness improvement and poor melt fluidity resulting in low production efficiency, no effective solutions have been proposed. Summary of the Invention

[0007] The purpose of this application is to provide a toughened polypropylene film, a preparation method and an application thereof in view of the deficiencies in the prior art, so as to solve at least the problems in the related technologies, such as less toughness improvement and poor melt fluidity resulting in low production efficiency.

[0008] To achieve the above purpose, the technical solutions adopted in this application are as follows:

[0009] In the first aspect, the present invention provides a toughened polypropylene film, including:

[0010] The first layer, which is composed of polypropylene;

[0011] The second layer, which is disposed on one side of the first layer and is composed of polypropylene, a toughening agent, an antioxidant, a nano filler, a dispersant, a fluorosilicon modifier, and a color masterbatch;

[0012] The third layer is disposed on the side of the second layer away from the first layer, and the third layer is composed of polypropylene, toughening agent, antioxidant, dispersant, and color masterbatch.

[0013] In some embodiments, in the second layer, the weight percentages of the components are as follows:

[0014] Polypropylene 60% - 75%;

[0015] Toughening agent 5% - 15%;

[0016] Antioxidant 0.1% - 0.5%;

[0017] Nanofiller 15% - 20%;

[0018] Dispersant 0.5% - 2%;

[0019] Fluorosilicon modifier 0.5% - 1.5%;

[0020] Color masterbatch 2% - 5%.

[0021] In some embodiments, in the second layer, the toughening agent is a core-shell rubber / nano-organophilic montmorillonite hybrid system.

[0022] In some embodiments, in the toughening agent of the second layer, the mass ratio of core-shell rubber to nano-organophilic montmorillonite is 6:1 - 3:1.

[0023] In some embodiments, in the third layer, the weight percentages of the components are as follows:

[0024] Polypropylene 80% - 90%;

[0025] Toughening agent 5% - 15%;

[0026] Antioxidant 0.1% - 0.5%;

[0027] Dispersant 0.5% - 2%;

[0028] Color masterbatch 3% - 8%.

[0029] In some embodiments, in the third layer, the toughening agent is a maleic anhydride grafted SEBS / hyperbranched polyester elastomer composite system.

[0030] In some embodiments, in the toughening agent of the third layer, the mass ratio of maleic anhydride grafted SEBS to hyperbranched polyester elastomer is 8:1 - 5:1.

[0031] In some of these embodiments, the antioxidant is any one or a combination of two of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-1,3,4-triazin-2-yl)propionate] and tris(2,4-di-tert-butylphenyl) phosphite.

[0032] In some of these embodiments, the nano filler is any one or a combination of more than one of nano calcium carbonate, nano alumina, and nano zinc oxide.

[0033] In some of these embodiments, the dispersant is nano silica.

[0034] In some of these embodiments, the fluorosilicon modifier is a fluorosilane coupling agent.

[0035] In some of these embodiments, the color masterbatch is any one or a combination of two of polypropylene white masterbatch and polypropylene black masterbatch.

[0036] In some of these embodiments, the thickness of the first layer is 15% to 30% of the thickness of the toughened polypropylene film;

[0037] The thickness of the second layer is 30% to 45% of the thickness of the toughened polypropylene film;

[0038] The thickness of the third layer is 30% to 45% of the thickness of the toughened polypropylene film.

[0039] In some of these embodiments, the toughened polypropylene film has a transverse tensile strength ≥ 22 MPa, a longitudinal tensile strength ≥ 25 MPa, a transverse elongation at break ≥ 550%, a longitudinal elongation at break ≥ 650%, a transverse right-angle tear force ≥ 8 N, and a longitudinal right-angle tear force ≥ 10 N.

[0040] In some of these embodiments, the heat resistance of the toughened polypropylene film is as follows:

[0041] 150 °C, 30 min: transverse shrinkage rate ≤ 0.5%, longitudinal shrinkage rate ≤ 0.5%;

[0042] 160 °C, 30 min: transverse shrinkage rate ≤ 1.0%, longitudinal shrinkage rate ≤ 1.0%;

[0043] 170 °C, 30 min: transverse shrinkage rate ≤ 1.5%, longitudinal shrinkage rate ≤ 1.5%.

[0044] Second, the present invention provides a method for preparing a toughened polypropylene film for preparing the toughened polypropylene film as described in the first aspect, including:

[0045] Raw material mixing: The raw materials of the first layer, the second layer, and the third layer are respectively and fully mixed to obtain the first-layer mixture, the second-layer mixture, and the third-layer mixture;

[0046] Melting and extrusion: The first-layer mixture, the second-layer mixture, and the third-layer mixture are respectively melted and extruded to obtain the first-layer molten material, the second-layer molten material, and the third-layer molten material;

[0047] Cast forming: The first-layer molten material, the second-layer molten material, and the third-layer molten material are subjected to cast forming and gradient cooling annealing to obtain the first initial film;

[0048] Tensile orientation: The first initial film is successively longitudinally stretched and transversely stretched to obtain the second initial film;

[0049] Corona treatment: The second initial film is subjected to corona treatment to obtain the toughened polypropylene film.

[0050] In some of these embodiments, in the melting and extrusion, the extrusion temperature of the first layer is 230 - 240 °C, the extrusion temperature of the second layer is 210 - 220 °C, the extrusion temperature of the third layer is 225 - 235 °C, and the rotation speed is 300 - 500 rpm.

[0051] In some of these embodiments, in the cast forming, the temperatures of the gradient cooling annealing are 120 °C, 80 °C, and 50 °C respectively.

[0052] In some of these embodiments, in the tensile orientation, the draw ratio of the longitudinal stretch is 3:1 - 5:1, and the draw ratio of the transverse stretch is 2:1 - 4:1.

[0053] In a third aspect, the present invention provides an application of the toughened polypropylene film as described in the first aspect or the toughened polypropylene film prepared by the preparation method of the toughened polypropylene film as described in the second aspect.

[0054] Compared with the related art, the toughened polypropylene film, preparation method, and application provided by the embodiments of the present application have the following technical effects:

[0055] 1) Excellent toughness performance: Through the synergistic effect of the core-shell rubber / nano-organophilic montmorillonite hybrid system and the maleic anhydride-grafted SEBS / hyperbranched polyester elastomer composite system, and the post-treatment process of gradient annealing, the tensile performance, tear resistance, and temperature resistance of the film are significantly improved, making it more suitable for the complex use environment of building waterproofing membranes;

[0056] 2) Good processability: The optimized formulation design ensures the melt fluidity and tensile orientation performance of the film during processing, improving production efficiency;

[0057] 3) Environmentally friendly: All auxiliaries are environmentally friendly materials, meeting the requirements of green development. Specific implementation manners

[0058] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the following describes and explains the present application in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present application.

[0059] Obviously, the embodiments described below are only some examples or embodiments of the present application. For those of ordinary skill in the art, without making creative efforts, the present application can also be applied to other similar scenarios based on these embodiments. In addition, it can also be understood that although the efforts made in such a development process may be complex and lengthy, for those of ordinary skill in the art related to the content disclosed in the present application, some design, manufacturing or production changes made on the basis of the technical content disclosed in the present application are only conventional technical means and should not be understood as the content disclosed in the present application being insufficient.

[0060] Referring to "embodiments" in the present application means that the specific features, structures or characteristics described in combination with the embodiments can be included in at least one embodiment of the present application. The phrase appears at various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those of ordinary skill in the art explicitly and implicitly understand that the embodiments described in the present application can be combined with other embodiments without conflict.

[0061] Unless otherwise defined, the technical terms or scientific terms involved in this application shall have the ordinary meanings understood by those with ordinary skills in the technical field to which this application belongs. The words such as "a", "an", "one kind", "the" and the like involved in this application do not indicate a quantity limitation and may represent a singular or plural number. The terms "comprising", "including", "having" and any variations thereof involved in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product or device comprising a series of steps or modules (units) is not limited to the listed steps or units, but may further include steps or units not listed, or may further include other steps or units inherent to these processes, methods, products or devices. The similar words such as "connected", "linked", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "plurality" involved in this application means two or more. "And / or" describes the association relationship of associated objects and indicates that three relationships may exist. For example, "A and / or B" may represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after. The terms "first", "second", "third" and the like involved in this application are only used to distinguish similar objects and do not represent a specific order for the objects.

[0062] Example 1

[0063] This example relates to the toughened polypropylene film of the present invention, a preparation method and an application.

[0064] In a schematic embodiment of the present invention, a toughened polypropylene film includes a first layer, a second layer and a third layer. Among them, the first layer is composed of polypropylene; the second layer is disposed on one side of the first layer, and the second layer is composed of polypropylene, a toughening agent, an antioxidant, a nano filler, a dispersant, a fluorosilicon modifier, and a color masterbatch; the third layer is disposed on the side of the second layer away from the first layer, and the third layer is composed of polypropylene, a toughening agent, an antioxidant, a dispersant, and a color masterbatch.

[0065] In the present invention, for the thicknesses of the first layer, the second layer and the third layer of the toughened polypropylene film, the percentages of their respective thicknesses in the total thickness are as follows:

[0066] The first layer: 15% - 30%;

[0067] The second layer: 30% - 45%;

[0068] The third layer: 30% - 45%.

[0069] Among them, in the second layer, the weight percentages of the components are as follows:

[0070] Polypropylene: 60% - 75%;

[0071] Toughening agent: 5% - 15%;

[0072] Antioxidant: 0.1% - 0.5%;

[0073] Nanofiller: 15% - 20%;

[0074] Dispersant: 0.5% - 2%;

[0075] Fluorosilicon modifier: 0.5% - 1.5%;

[0076] Color masterbatch: 2% - 5%.

[0077] In some of these embodiments, in the second layer, the toughening agent is a core-shell rubber / nano-organophilic montmorillonite hybrid system.

[0078] In some of these embodiments, in the toughening agent of the second layer, the mass ratio of core-shell rubber to nano-organophilic montmorillonite is 6:1 - 3:1.

[0079] Among them, in the third layer, the weight percentages of each component are as follows:

[0080] Polypropylene: 80% - 90%;

[0081] Toughening agent: 5% - 15%;

[0082] Antioxidant: 0.1% - 0.5%;

[0083] Dispersant: 0.5% - 2%;

[0084] Color masterbatch: 3% - 8%.

[0085] In some of these embodiments, in the third layer, the toughening agent is a maleic anhydride-grafted SEBS / hyperbranched polyester elastomer composite system.

[0086] In some of these embodiments, in the toughening agent of the third layer, the mass ratio of maleic anhydride-grafted SEBS to hyperbranched polyester elastomer is 8:1 - 5:1.

[0087] In some of these embodiments, the antioxidant is any one or a combination of two of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-1,3,4-triazin-2-yl)propionate] and tris(2,4-di-tert-butylphenyl) phosphite.

[0088] In some of these embodiments, the nanofiller is any one or a combination of more than one of nano calcium carbonate, nano alumina, and nano zinc oxide.

[0089] In some of these embodiments, the dispersant is nano silica.

[0090] In some of these embodiments, the fluorosilicon modifier is a fluorosilane coupling agent.

[0091] In some of these embodiments, the color masterbatch is any one or a combination of two of polypropylene white masterbatch and polypropylene black masterbatch.

[0092] For the toughened polypropylene film of the present invention, its preparation method is as follows:

[0093] (I) Raw material mixing: The raw materials of the first layer, the second layer, and the third layer are respectively and fully mixed to obtain the first layer mixture, the second layer mixture, and the third layer mixture;

[0094] (II) Melting and extrusion: The first layer mixture, the second layer mixture, and the third layer mixture are respectively melted and extruded to obtain the first layer molten material, the second layer molten material, and the third layer molten material;

[0095] (III) Casting and forming: The first layer molten material, the second layer molten material, and the third layer molten material are subjected to casting and forming and gradient cooling and annealing to obtain the first initial film;

[0096] (IV) Tensile orientation: The first initial film is successively longitudinally stretched and transversely stretched to obtain the second initial film;

[0097] (V) Corona treatment: The second initial film is subjected to corona treatment to obtain the toughened polypropylene film.

[0098] In (I) raw material mixing, the raw materials of each layer are respectively put into the corresponding mixing equipment according to the component ratio for mixing.

[0099] Generally, the mixing equipment includes but is not limited to a high-speed mixer.

[0100] In (II) melting and extrusion, the extrusion temperature of the first layer is 230 - 240 °C, the extrusion temperature of the second layer is 210 - 220 °C, the extrusion temperature of the third layer is 225 - 235 °C, and the rotation speed is 300 - 500 rpm.

[0101] Generally, the melting equipment includes but is not limited to a screw extruder.

[0102] In (III) casting and forming, the temperatures of gradient cooling and annealing are 120 °C, 80 °C, and 50 °C respectively.

[0103] In (IV) tensile orientation, the longitudinal stretching ratio is 3:1 - 5:1, and the transverse stretching ratio is 2:1 - 4:1.

[0104] Preferably, the longitudinal stretching ratios are 3:1, 4:1, and 5:1.

[0105] Preferably, the draw ratio of the transverse stretching is 2:1, 3:1, or 4:1.

[0106] In (v) corona treatment, the stretched second initial film is subjected to corona treatment, which can increase the surface polarity, thus facilitating subsequent coating or other treatments.

[0107] For the toughened polypropylene film of the present invention, its properties are shown in the following table.

[0108]

[0109]

[0110] For the toughened polypropylene film of the present invention, its applications are as follows:

[0111] 1) Release film base film for building waterproof coiled materials;

[0112] 2) Packaging materials;

[0113] 3) Agricultural films.

[0114] The technical effects of the present invention are as follows:

[0115] 1) Excellent toughness performance: Through the synergistic effect of the core-shell rubber / nano-organophilic montmorillonite hybrid system and the maleic anhydride grafted SEBS / hyperbranched polyester elastomer composite system, as well as the post-treatment process of gradient annealing, the tensile performance, tear resistance, and temperature resistance of the film are significantly improved, making it more suitable for the complex use environment of building waterproof coiled materials;

[0116] 2) Good processability: The optimized formulation design ensures the melt fluidity and tensile orientation performance of the film during processing, improving production efficiency;

[0117] 3) Environmentally friendly: All additives are environmentally friendly materials, meeting the requirements of green development.

[0118] Example 2

[0119] This example relates to the specific implementation method of the toughened polypropylene film.

[0120] In this example, the relevant parameters of the toughened polypropylene film are as follows:

[0121] The first layer: 100% polypropylene;

[0122] The second layer: 65% polypropylene, 8% core-shell rubber, 1.5% nano-organophilic montmorillonite, 18% nano filler, 1% antioxidant, 0.5% dispersant, 1% fluorosilicon agent, 5% color masterbatch;

[0123] The third layer: 81.5% polypropylene, 10% maleic anhydride grafted SEBS (MAH-g-SEBS), 2% hyperbranched polyester, 1% antioxidant, 0.5% dispersant, 5% color masterbatch.

[0124] In this embodiment, the preparation process of the toughened polypropylene film is as follows:

[0125] 1. Raw material mixing: Add the raw materials into a high-speed mixer according to the formula ratio and mix them evenly.

[0126] 2. Melting extrusion: Extrude the mixed raw materials through an extruder, and control the extrusion temperature as follows: Layer A 230 - 240 °C → Layer B 210 - 220 °C → Layer C 225 - 235 °C, and the screw speed is 300 - 500 rpm.

[0127] 3. Casting forming: Pass the extruded molten material through the surface of the cooling roll of a casting machine to form a film, and the post-treatment adopts a gradient cooling annealing process with the cooling temperature of 120 °C → 80 °C → 50 °C.

[0128] 4. Tensile orientation: Perform longitudinal and transverse stretching on the film formed by casting, and the stretching ratios are 3 - 5 times and 2 - 4 times respectively.

[0129] 5. Rewinding and packaging: Perform corona treatment on the stretched film to increase the surface polarity for subsequent coating or other treatments.

[0130] Among them, some of the products used in this embodiment are shown in the following table.

[0131] Name Model Manufacturer Polypropylene PP H3400 LG Chem Maleic Anhydride Grafted SEBS FG1924X Kraton Core-Shell Rubber E920 Arkema France Nanometer Organic Montmorillonite DK4 Zhejiang Fenghong Nanometer Filler P80-2 Anhui Weikai Antioxidant GW001 Anhui Weikai Masterbatch E90471CH Shanghai Yudi

[0132] Example 3

[0133] This embodiment relates to the specific implementation manner of the toughened polypropylene film.

[0134] In this embodiment, the relevant parameters of the toughened polypropylene film are as follows:

[0135] The first layer: 100% polypropylene;

[0136] The second layer: 67% polypropylene, 9% core-shell rubber, 3% nano-organophilic montmorillonite, 15% nano-filler, 0.5% antioxidant, 0.5% dispersant, 1% fluorosilicone agent, 4% color masterbatch;

[0137] The third layer: 82% polypropylene, 10% maleic anhydride grafted SEBS (MAH-g-SEBS), 2% hyperbranched polyester, 0.5% antioxidant, 0.5% dispersant, 5% color masterbatch.

[0138] In this embodiment, the preparation process of the toughened polypropylene film is the same as that in Example 2 and will not be elaborated here.

[0139] Among them, some of the products used in this embodiment are shown in the following table.

[0140]

[0141]

[0142] Example 4

[0143] This embodiment relates to a specific implementation manner of a toughened polypropylene film.

[0144] In this embodiment, the relevant parameters of the toughened polypropylene film are as follows:

[0145] The first layer: 100% polypropylene;

[0146] The second layer: 65% polypropylene, 12% core-shell rubber, 2% nano-organophilic montmorillonite, 15% nano filler, 0.5% antioxidant, 0.5% dispersant, 1% fluorosilicone agent, 4% color masterbatch;

[0147] The third layer: 85% polypropylene, 8% maleic anhydride grafted SEBS (MAH-g-SEBS), 1% hyperbranched polyester, 0.5% antioxidant, 0.5% dispersant, 5% color masterbatch.

[0148] In this embodiment, the preparation process of the toughened polypropylene film is the same as that of Example 2 and will not be elaborated here.

[0149] Among them, some of the products used in this embodiment are shown in the following table.

[0150] Name Model Manufacturer Polypropylene PP H3400 LG Chem Maleic Anhydride Grafted SEBS FG1924X Kraton Core-Shell Rubber E920 Arkema France Nanometer Organic Montmorillonite DK4 Zhejiang Fenghong Nanometer Filler P80-2 Anhui Weikai Antioxidant GW001 Anhui Weikai Masterbatch E90471CH Shanghai Yudi

[0151] Example 5

[0152] This embodiment relates to a specific implementation manner of a toughened polypropylene film.

[0153] In this embodiment, the relevant parameters of the toughened polypropylene film are as follows:

[0154] The first layer: 100% polypropylene;

[0155] The second layer: 67% polypropylene, 9% core-shell rubber, 3% nano-organophilic montmorillonite, 15% nano filler, 0.5% antioxidant, 0.5% dispersant, 1% fluorosilicone agent, 4% color masterbatch;

[0156] The third layer: 85% polypropylene, 8% maleic anhydride grafted SEBS (MAH-g-SEBS), 1% hyperbranched polyester, 0.5% antioxidant, 0.5% dispersant, 5% color masterbatch.

[0157] In this embodiment, the preparation process of the toughened polypropylene film is the same as that in Embodiment 2 and will not be elaborated here.

[0158] Among them, some of the products used in this embodiment are shown in the following table.

[0159] Name Model Manufacturer Polypropylene PP H3400 LG Chem Maleic Anhydride Grafted SEBS FG1924X Kraton Core-Shell Rubber E920 Arkema France Nanometer Organic Montmorillonite DK4 Zhejiang Fenghong Nanometer Filler P80-2 Anhui Weikai Antioxidant GW001 Anhui Weikai Masterbatch E90471CH Shanghai Yudi

[0160] Embodiment 6

[0161] This embodiment relates to Control Experimental Group 1 of the present invention.

[0162] In this embodiment, the relevant parameters of the polypropylene film (ordinary CPP, cast PP) are as follows

[0163] The first layer: 100% homopolypropylene;

[0164] The second layer: 98.2% copolymerized polypropylene, 1.5% antioxidant, 0.1% slip agent, 0.2% nucleating agent;

[0165] The third layer: 30% homopolypropylene, 70% copolymerized polypropylene.

[0166] In this embodiment, the preparation process of the toughened polypropylene film is the same as that in Embodiment 2 and will not be elaborated here.

[0167] Among them, some of the products used in this embodiment are shown in the following table.

[0168] Name Model Manufacturer Homopolypropylene PP H3400 LG Chem Random Copolymer Polypropylene PP R3450 LG Chem Antioxidant GW001 Anhui Weikai

[0169] Embodiment 7

[0170] This embodiment relates to Control Experimental Group 2 of the present invention.

[0171] In this embodiment, the relevant parameters of the polypropylene film (ordinary CPP, cast PP) are as follows

[0172] The first layer: 100% homopolypropylene;

[0173] The second layer: 98.2% copolymerized polypropylene, 1.5% antioxidant, 0.1% slip agent, 0.2% nucleating agent;

[0174] The third layer: 40% homopolypropylene, 60% copolymerized polypropylene.

[0175] In this embodiment, the preparation process of the polypropylene film is the same as that in Embodiment 2 and will not be elaborated here.

[0176] Among them, some of the products used in this embodiment are shown in the following table.

[0177] Name Model Manufacturer Homopolypropylene PP H3400 LG Chem Random Copolymer Polypropylene PP R3450 LG Chem Antioxidant GW001 Anhui Weikai

[0178] Example 8

[0179] This example relates to control experimental group 3 of the present invention.

[0180] In this embodiment, the relevant parameters of polypropylene film (ordinary CPP, cast PP) are as follows

[0181] First layer: homopolymer polypropylene 100%;

[0182] The second layer: copolymerized polypropylene 98.2%, antioxidant 1.5%, lubricant 0.1%, nucleating agent 0.2%;

[0183] The third layer: 50% homopolymer polypropylene, 50% copolymer polypropylene.

[0184] In this embodiment, the preparation process of the polypropylene film is the same as that of Embodiment 2, and will not be described again here.

[0185] Among them, some of the products used in this embodiment are shown in the following table.

[0186] Name Model Manufacturer Homopolypropylene PP H3400 LG Chem Random Copolymer Polypropylene PP R3450 LG Chem Antioxidant GW001 Anhui Weikai

[0187] Example 9

[0188] This embodiment relates to the performance testing of toughened polypropylene film.

[0189] The performance data of the toughened polypropylene films of Examples 2 to 5 of the present invention and the control experimental groups of Examples 6 to 8 are as follows:

[0190]

[0191]

[0192] It can be seen from the above data that, compared with the control experimental group, the tensile strength, elongation at break, temperature resistance, and right-angle tearing force of the toughened polypropylene film of the present invention are significantly better than those of the control experimental group, and are more suitable for the complex use environment of building waterproof membranes. In addition, the temperature resistance of the toughened polypropylene film of the present invention is improved, which can reduce the influence of production temperature on the toughened polypropylene film, improve the adaptability of the product, and at the same time, can avoid the toughened polypropylene film from being scalded or the product from wrinkling during production, and the tensile strength and tearing resistance are significantly increased, which can effectively avoid the film from being torn and damaged when the film is removed, and improve the construction efficiency.

[0193] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0194] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A toughened polypropylene film, characterized in that, Comprising: The first layer, which is composed of polypropylene; The second layer, which is disposed on one side of the first layer and is composed of polypropylene, toughening agent, antioxidant, nano filler, dispersant, fluorosilicon modifier, and masterbatch; The third layer, which is disposed on the side of the second layer away from the first layer and is composed of polypropylene, toughening agent, antioxidant, dispersant, and masterbatch.

2. The toughened polypropylene film according to claim 1, wherein In the second layer, the weight percentages of the components are as follows: Polypropylene 60% - 75%; Toughening agent 5% - 15%; Antioxidant 0.1% - 0.5%; Nano filler 15% - 20%; Dispersant 0.5% - 2%; Fluorosilicon modifier 0.5% - 1.5%; Masterbatch 2% - 5%; and / or In the third layer, the weight percentages of the components are as follows: Polypropylene 80% - 90%; Toughening agent 5% - 15%; Antioxidant 0.1% - 0.5%; Dispersant 0.5% - 2%; Masterbatch 3% - 8%.

3. The toughened polypropylene film according to claim 1 or 2, characterized in that, In the second layer, the toughening agent is a core - shell rubber / nano - organic montmorillonite hybrid system; and / or In the third layer, the toughening agent is a maleic anhydride - grafted SEBS / hyperbranched polyester elastomer composite system; and / or The antioxidant is any one or a combination of two of pentaerythritol tetra[β-(3,5 - di - tert - butyl - 1,3,4 - triazin - 2 - yl) propionate] and tris[2,4 - di - tert - butylphenyl] phosphite; and / or The nano filler is any one or a combination of multiple of nano calcium carbonate, nano alumina, and nano zinc oxide; and / or The dispersant is nano silica; and / or The fluorosilicon modifier is a fluorosilane coupling agent; and / or The masterbatch is any one or a combination of two of polypropylene white masterbatch and polypropylene black masterbatch.

4. The toughened polypropylene film according to claim 3, wherein, In the toughening agent of the second layer, the mass ratio of core - shell rubber to nano - organic montmorillonite is 6:1 - 3:1; and / or In the toughening agent of the third layer, the mass ratio of maleic anhydride - grafted SEBS to hyperbranched polyester elastomer is 8:1 - 5:

1.

5. The toughened polypropylene film according to claim 1, wherein The thickness of the first layer is 15% - 30% of the thickness of the toughened polypropylene film; The thickness of the second layer is 30% - 45% of the thickness of the toughened polypropylene film; The thickness of the third layer is 30% - 45% of the thickness of the toughened polypropylene film.

6. The toughened polypropylene film according to claim 1, wherein The transverse tensile strength of the toughened polypropylene film ≥ 22 MPa, longitudinal tensile strength ≥ 25 MPa, transverse elongation at break ≥ 550%, longitudinal elongation at break ≥ 650%, transverse right - angle tear force ≥ 8 N, and longitudinal right - angle tear force ≥ 10 N.

7. The toughened polypropylene film according to claim 1, wherein The heat resistance of the toughened polypropylene film is as follows: 150 °C, 30 min: transverse shrinkage rate ≤ 0.5%, longitudinal shrinkage rate ≤ 0.5%; 160 °C, 30 min: transverse shrinkage rate ≤ 1.0%, longitudinal shrinkage rate ≤ 1.0%; 170 °C, 30 min: transverse shrinkage rate ≤ 1.5%, longitudinal shrinkage rate ≤ 1.5%.

8. A method for preparing a toughened polypropylene film, which is used to prepare the toughened polypropylene film according to any one of claims 1 to 7, characterized in that, Comprising: Raw material mixing: Mix the raw materials of the first layer, the second layer, and the third layer separately and thoroughly to obtain the first - layer mixture, the second - layer mixture, and the third - layer mixture respectively; Melt extrusion: The first layer mixture, the second layer mixture, and the third layer mixture are respectively subjected to melt extrusion to obtain the first layer molten material, the second layer molten material, and the third layer molten material; Cast forming: The first layer molten material, the second layer molten material, and the third layer molten material are subjected to cast forming and gradient cooling annealing to obtain the first initial film; Stretching orientation: The first initial film is successively longitudinally stretched and transversely stretched to obtain the second initial film; Corona treatment: The second initial film is subjected to corona treatment to obtain the toughened polypropylene film.

9. The preparation method according to claim 8, characterized in that, In melt extrusion, the extrusion temperature of the first layer is 230 - 240 °C, the extrusion temperature of the second layer is 210 - 220 °C, the extrusion temperature of the third layer is 225 - 235 °C, and the rotation speed is 300 - 500 rpm; and / or In cast forming, the temperatures of gradient cooling annealing are 120 °C, 80 °C, and 50 °C respectively; and / or In stretching orientation, the longitudinal stretching ratio is 3:1 - 5:1, and the transverse stretching ratio is 2:1 - 4:

1.

10. Use of the toughened polypropylene film according to any one of claims 1 - 7 or the toughened polypropylene film prepared by the preparation method of the toughened polypropylene film according to any one of claims 8 - 9.

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