Extinction milky-white polypropylene film and preparation method thereof

Abstract

The invention relates to the technical field of plastic films, in particular to an extinction milky-white polypropylene film and a preparation method thereof.The polypropylene film comprises a heat sealing layer A, a milky-white layer B, a milky-white layer C and a temperature-resistant extinction layer D; the mass ratio of the heat sealing layer A to the milky white layer B to the milky white layer C to the temperature-resistant extinction layer D is (18-20): (30-35): (30-35): (10-22); according to the prepared matt milky-white polypropylene film, a traditional three-layer structure is upgraded into a four-layer structure, the matt milky-white polypropylene film has a matt effect, is resistant to high temperature and also has a milky-white effect, a traditional double-layer structure that matt BOPP is attached to milky-white CPP through glue can be reduced into a single-layer structure, a production process is reduced, and the matt milky-white polypropylene film is more economical; and glue and solvent are not needed, so that the coating is more environment-friendly.

Description

Technical Field

[0001] The invention relates to the technical field of plastic films, and more particularly to a matt milky white polypropylene film and a preparation method thereof. Background Art

[0002] In the field of small food packaging, some customers require products with a matte surface effect and a milky white covering effect. Currently, flexible packaging companies generally use a double-layer structure of matte BOPP glued to milky white CPP. The solvent used in the glue is volatile organic compounds, which has waste gas emission problems.

[0003] At present, the preparation of polypropylene cast film is generally a three-layer structure. The matte raw material used in the matte layer is the matte masterbatch, which is composed of a blend of binary copolymer polypropylene and high-density polyethylene. Due to the presence of low-melting-point high-density polyethylene, the product is not resistant to high temperatures. Polypropylene matte film has to be in contact with high-temperature knives during the bag-making process. Over time, the low-melting-point high-density polyethylene component will adhere to the knives and require frequent cleaning, which seriously reduces production efficiency.

[0004] Therefore, the present invention aims at the above problems and provides a matte milky white polypropylene film and a preparation method thereof. Summary of the invention

[0005] The purpose of the present invention is to provide a matt opalescent polypropylene film and a preparation method thereof to solve the above problems. The matt opalescent polypropylene film provided by the present invention upgrades the traditional three-layer structure to a four-layer structure, has a matt effect and high temperature resistance while also having an opalescent effect. The double-layer structure of the traditional matt BOPP and opalescent CPP can be reduced to a single-layer structure by gluing, thereby reducing one production process and being more economical; and no glue and solvent are needed, which is more environmentally friendly.

[0006] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions:

[0007] The first aspect of the present invention provides a matte milky white polypropylene film, comprising a heat sealing layer A, a milky white layer B, a milky white layer C, and a temperature-resistant matte layer D; the mass ratio of the heat sealing layer A, the milky white layer B, the milky white layer C, and the temperature-resistant matte layer D is (18-20): (30-35): (30-35): (10-22).

[0008] Furthermore, the raw materials for preparing the heat sealing layer A include terpolymer polypropylene F4908 (Maoming Petrochemical) and terpolymer polypropylene F4608 (Maoming Petrochemical); the mass ratio of the terpolymer polypropylene F4908 to the terpolymer polypropylene F4608 is (1-2):1.

[0009] Furthermore, the raw materials for preparing the milky white layer B include homopolypropylene T30S (Zhongjing Petrochemical) and milky white masterbatch R811-YY (Xiamen Xinwancai); the mass ratio of the homopolypropylene T30S and the milky white masterbatch R811-YY is (4-5):1.

[0010] Furthermore, the raw materials for preparing the milky white layer C include homopolypropylene T30S (Zhongjing Petrochemical) and milky white masterbatch R811-YY (Xiamen Xinwancai); the mass ratio of the homopolypropylene T30S and the milky white masterbatch is (4-5):1.

[0011] Furthermore, the raw materials for preparing the heat-resistant matte layer D include block copolymer polypropylene PC684S (imported material from Japan) and open smooth masterbatch SAB36 (Gaoboer new material); the mass ratio of the block copolymer polypropylene PC684S to the open smooth masterbatch SAB36 is 100:(1-2).

[0012] Furthermore, the thickness of the polypropylene film is 20 μm to 60 μm.

[0013] The second aspect of the present invention provides a method for preparing the above-mentioned matte milky white polypropylene film, comprising: extruding the raw materials for preparing the heat sealing layer A, the milky white layer B, the milky white layer C, and the temperature-resistant matte layer D into shape.

[0014] Furthermore, the extrusion temperature is 195°C to 230°C.

[0015] In the present invention, the preparation method of the matt polypropylene aluminum-plated film is not particularly limited, and the method is a conventional technical means known to those skilled in the art.

[0016] The method for preparing the above-mentioned matt milky white polypropylene film of the present invention specifically comprises the following steps:

[0017] Step 1, preparing materials: prepare the raw materials for the heat sealing layer A, the milky white layer B, the milky white layer C, and the temperature-resistant matte layer D respectively according to the mass ratio and set aside;

[0018] Step 2, loading: The raw materials of each layer prepared in step 1 are respectively loaded into the hoppers of extruder I, extruder II, extruder III and extruder IV;

[0019] Step 3, preparation of matt milky white polypropylene film: the extruders increase the set temperature to 195°C, 200°C, 200°C, 200°C, 210°C, 210°C, 210°C, 220°C, 220°C, 230°C, 230°C, 230°C, 235°C, 235°C, 235°C, and extrude the raw materials of each layer in the hoppers of extruder I, extruder II, extruder III and extruder IV through a T-die under a pressure of 10MPa to 18MPa, and obtain the matt milky white polypropylene film by traction, cooling, corona treatment and winding.

[0020] Beneficial effects:

[0021] The matte opalescent polypropylene film prepared by the present invention upgrades the traditional three-layer structure to a four-layer structure, has a matte effect and high temperature resistance, and also has an opalescent effect. The double-layer structure of the traditional matte BOPP and the opalescent CPP can be reduced to a single-layer structure by gluing, thereby reducing one production process and being more economical; and no glue and solvent are needed, which is more environmentally friendly.

[0022] The matt milky white polypropylene film prepared by the invention has a simple preparation method, abundant raw material sources, low price, low production cost and is suitable for large-scale industrial production. DETAILED DESCRIPTION

[0023] The present invention will be further explained below in conjunction with the embodiments.

[0024] Example 1

[0025] A matte milky white polypropylene film

[0026] It includes heat sealing layer A, milky white layer B, milky white layer C, and temperature-resistant matte layer D;

[0027] Among them, the mass ratio of heat sealing layer A, milky white layer B, milky white layer C, and temperature-resistant matte layer D is 18:33:33:16;

[0028] Among them, the heat sealing layer A is made of a mixture of ternary copolymer polypropylene F4908 (Maoming Petrochemical) and ternary copolymer polypropylene F4608 (Maoming Petrochemical) in a mass ratio of 1:1; the milky white layer B is made of a mixture of homopolymer polypropylene T30S (Zhongjing Petrochemical) and milky white masterbatch R811-YY (Xiamen Xinwancai) in a mass ratio of 4:1; the milky white layer C is made of a mixture of homopolymer polypropylene T30S (Zhongjing Petrochemical) and milky white masterbatch R811-YY (Xiamen Xinwancai) in a mass ratio of 4:1; the heat-resistant matte layer D is made of a mixture of block copolymer polypropylene PC684S (imported material from Japan) and open smooth masterbatch SAB36 (Gaobor New Materials) in a mass ratio of 100:1.5.

[0029] The preparation steps are as follows:

[0030] Step 1, preparing materials: prepare the raw materials for the heat sealing layer A, the milky white layer B, the milky white layer C, and the temperature-resistant matte layer D respectively according to the mass ratio and set aside;

[0031] Step 2, loading: The raw materials of each layer prepared in step 1 are respectively loaded into the hoppers of extruder I, extruder II, extruder III and extruder IV;

[0032] Step 3, preparation of matt milky white polypropylene film: the extruders increase the set temperature to 195°C, 200°C, 200°C, 200°C, 210°C, 210°C, 210°C, 220°C, 220°C, 230°C, 230°C, 230°C, 235°C, 235°C, 235°C according to a gradient, and the raw materials of each layer in the hoppers of extruder I, extruder II, extruder III and extruder IV are extruded through a T-die under a pressure of 10MPa to 18MPa, and a matt milky white polypropylene film with a thickness of 45μm is obtained by traction, cooling, corona treatment and winding.

[0033] Example 2

[0034] A matte milky white polypropylene film

[0035] It includes heat sealing layer A, milky white layer B, milky white layer C, and temperature-resistant matte layer D;

[0036] Among them, the mass ratio of heat sealing layer A, milky white layer B, milky white layer C, and temperature-resistant matte layer D is 20:35:35:10;

[0037] Among them, the heat sealing layer A is made of a mixture of ternary copolymer polypropylene F4908 (Maoming Petrochemical) and ternary copolymer polypropylene F4608 (Maoming Petrochemical) in a mass ratio of 1.5:1; the milky white layer B is made of a mixture of homopolymer polypropylene T30S (Zhongjing Petrochemical) and milky white masterbatch R811-YY (Xiamen Xinwancai) in a mass ratio of 5:1; the milky white layer C is made of a mixture of homopolymer polypropylene T30S (Zhongjing Petrochemical) and milky white masterbatch R811-YY (Xiamen Xinwancai) in a mass ratio of 4:1; the heat-resistant matte layer D is made of a mixture of block copolymer polypropylene PC684S (imported material from Japan) and open smooth masterbatch SAB36 (Gaobor New Materials) in a mass ratio of 100:1.

[0038] The preparation steps are as follows:

[0039] Step 1, preparing materials: prepare the raw materials for the heat sealing layer A, the milky white layer B, the milky white layer C, and the temperature-resistant matte layer D respectively according to the mass ratio and set aside;

[0040] Step 2, loading: The raw materials of each layer prepared in step 1 are respectively loaded into the hoppers of extruder I, extruder II, extruder III and extruder IV;

[0041] Step 3, preparation of matt milky white polypropylene film: the extruders increase the set temperature to 195°C, 200°C, 200°C, 200°C, 210°C, 210°C, 210°C, 220°C, 220°C, 230°C, 230°C, 230°C, 235°C, 235°C, 235°C according to a gradient, and the raw materials of each layer in the hoppers of extruder I, extruder II, extruder III and extruder IV are extruded through a T-die under a pressure of 10MPa to 18MPa, and a matt milky white polypropylene film with a thickness of 45μm is obtained by traction, cooling, corona treatment and winding.

[0042] Example 3

[0043] A matte milky white polypropylene film

[0044] It includes heat sealing layer A, milky white layer B, milky white layer C, and temperature-resistant matte layer D;

[0045] Among them, the mass ratio of heat sealing layer A, milky white layer B, milky white layer C, and temperature-resistant matte layer D is 20:32:32:16;

[0046] Among them, the heat sealing layer A is made of ternary copolymer polypropylene F4908 (Maoming Petrochemical) and ternary copolymer polypropylene F4608 (Maoming Petrochemical) in a mass ratio of 2:1; the milky white layer B is made of homopolymer polypropylene T30S (Zhongjing Petrochemical) and milky white masterbatch R811-YY (Xiamen Xinwancai) in a mass ratio of 4.5:1; the milky white layer C is made of homopolymer polypropylene T30S (Zhongjing Petrochemical) and milky white masterbatch R811-YY (Xiamen Xinwancai) in a mass ratio of 4.5:1; the heat-resistant matte layer D is made of block copolymer polypropylene PC684S (Japanese imported material) and open smooth masterbatch SAB36 (Gaobor New Materials) in a mass ratio of 100:1.5.

[0047] The preparation steps are as follows:

[0048] Step 1, preparing materials: prepare the raw materials for the heat sealing layer A, the milky white layer B, the milky white layer C, and the temperature-resistant matte layer D respectively according to the mass ratio and set aside;

[0049] Step 2, loading: The raw materials of each layer prepared in step 1 are respectively loaded into the hoppers of extruder I, extruder II, extruder III and extruder IV;

[0050] Step 3, preparation of matt milky white polypropylene film: the extruders increase the set temperature to 195°C, 200°C, 200°C, 200°C, 210°C, 210°C, 210°C, 220°C, 220°C, 230°C, 230°C, 230°C, 235°C, 235°C, 235°C according to a gradient, and the raw materials of each layer in the hoppers of extruder I, extruder II, extruder III and extruder IV are extruded through a T-die under a pressure of 10MPa to 18MPa, and a matt milky white polypropylene film with a thickness of 45μm is obtained by traction, cooling, corona treatment and winding.

[0051] The structure of the traditional matte opalescent polypropylene film is: BOPP / matte ink / glue / opalescent CPP. It requires two processes, printing and ink, both of which will generate waste gas. The matte opalescent polypropylene film prepared by the present invention is a single multifunctional composite material. The single material can achieve an alternative product with equivalent appearance, which is more energy-saving and environmentally friendly. By comparing the haze and heat sealing properties, the matte opalescent polypropylene film prepared by the present invention has reached a level comparable to that of the traditional matte opalescent polypropylene film (composite structure), as shown in Table 1.

[0052] Table 1

[0053]

[0054] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited by the description of the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

[0055] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A matt milky white polypropylene film, characterized in that: The polypropylene film comprises a heat sealing layer A, an opal layer B, an opal layer C, and a heat-resistant matte layer D; the mass ratio of the heat sealing layer A, the opal layer B, the opal layer C, and the heat-resistant matte layer D is (18-20): (30-35): (30-35): (10-22).

2. The polypropylene film according to claim 1, characterized in that The raw materials for preparing the heat sealing layer A include terpolymer polypropylene F4908 and terpolymer polypropylene F4608; the mass ratio of the terpolymer polypropylene F4908 to the terpolymer polypropylene F4608 is (1-2):

1.

3. The polypropylene film according to claim 1, characterized in that The raw materials for preparing the milky white layer B include homopolypropylene T30S and milky white masterbatch R811-YY; the mass ratio of the homopolypropylene T30S and the milky white masterbatch R811-YY is (4-5):

1.

4. The polypropylene film according to claim 1, characterized in that The raw materials for preparing the milky white layer C include homopolypropylene T30S and milky white masterbatch R811-YY; the mass ratio of the homopolypropylene T30S and the milky white masterbatch R811-YY is (4-5):

1.

5. The polypropylene film according to claim 1, characterized in that The raw materials for preparing the heat-resistant matte layer D include block copolymer polypropylene PC684S imported from Japan and open smooth masterbatch SAB36 of Gaoboer new material; the mass ratio of the block copolymer polypropylene PC684S to the open smooth masterbatch is 100:(1-2).

6. The polypropylene film according to claim 5, characterized in that The thickness of the polypropylene film is 20 μm to 60 μm.

7. A method for preparing a polypropylene film according to any one of claims 1 to 6, characterized in that: The preparation method comprises: extruding and molding the raw materials for preparing the heat sealing layer A, the milky white layer B, the milky white layer C and the temperature-resistant matte layer D.

8. The preparation method according to claim 7, characterized in that: The extrusion temperature is 195°C to 230°C.

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