Preparation method of high-barrier low-temperature-resistant PVDC film

Abstract

A preparation method of a high-barrier low-temperature-resistant PVDC film comprises the following steps: (1) cutting a double-layer PVDC film along the edge of the film by using a splitting machine, and separating the double-layer PVDC film into a roll of single-layer PVDC film and b roll of single-layer PVDC film; (2) respectively fixing the separated film roll a and the separated film roll b on an unreeling machine A and an unreeling machine B of a solvent-free compound machine, and ensuring that the film rolls are attached to equipment; (3) spraying a glue solution from a coating unit end, sequentially passing through a fixed roller, a metering roller, a transfer roller, a coating roller and a coating press roller, and coating the glue solution on the inner layers of the film rolls a and b; after compounding, passing through a metal flattening roller; and (4) after compounding and flattening, starting to roll, putting the roll into a 38-DEG C curing box for curing, after curing for 24 hours, rewinding a film roll, rewinding an outer-layer film to the inner side of the paper tube to expel bubbles, re-putting the rewound film roll into the 38-DEG C curing box for curing for 24 hours, and then taking out the film roll to obtain a product. According to the invention, the problems of poor durability and low barrier property of the PVDC film in a low-temperature environment are effectively solved.

Description

Technical Field

[0001] The invention relates to the technical field of PVDC films, and in particular to a method for preparing a high-barrier and low-temperature-resistant PVDC film. Background Art

[0002] PVDC, or polyvinylidene chloride, is a high barrier material. In addition to the general properties of plastics, it also has self-extinguishing, oil resistance, taste retention, excellent moisture resistance, mildew resistance and other properties. It also has excellent printing performance, composite performance and transparent properties. As a plastic material with excellent barrier properties, it is widely used in the preparation of films.

[0003] However, at temperatures below 15°C, the molecular spatial structure of the PVDC film will change, which can easily lead to brittle and broken PVDC casing films. The barrier properties and durability of traditional PVDC films in low-temperature environments are still insufficient. In low-temperature environments, the casing film becomes brittle and prone to pinholes. Summary of the invention

[0004] In order to overcome the deficiencies in the background technology, the present invention discloses a method for preparing a high-barrier and low-temperature-resistant PVDC film.

[0005] In order to achieve the above-mentioned invention object, the present invention adopts the following technical scheme: A method for preparing a high-barrier low-temperature-resistant PVDC film, the specific steps are as follows: (1) Using a slitting machine to cut the double-layer PVDC film along the edge of the film, the double-layer PVDC film is separated into two rolls of single-layer PVDC film, roll a and roll b; (2) Fix the separated a and b film rolls on the unwinder A and unwinder B of the solvent-free laminating machine respectively to ensure that the film rolls fit the equipment; (3) Spray the glue liquid from the coating unit end, and then pass through the fixed roller, metering roller, transfer roller, coating roller, and coating pressure roller in sequence to coat the glue liquid onto the inner layer of the film rolls a and b; adjust the machine speed to 50-80 m / min for lamination, set the laminating roller temperature to 75-80 °C, and pass through the metal flattening roller after lamination; (4) After the composite flattening in step (3), the film roll is rolled up and placed in a 38°C curing box for curing. After curing for 24 hours, the film roll needs to be rewound, and the outer film is folded to the inside of the paper tube to drive out the bubbles. The rewound film roll is then placed back in a 38°C curing box for curing for 24 hours, and then the film roll is taken out to obtain the product.

[0006] Furthermore, the glue solution is a mixture of castor oil polyether polyol and polycyanate at a mass ratio of 70-90:100, and then 2-5wt% of an anti-low temperature additive is added.

[0007] Furthermore, the roller surface of the metal flattening roller is made of stainless steel, so that the film roll remains flat and wrinkle-free during the winding process, and the temperature of the metal flattening roller is set to 10-15°C.

[0008] Furthermore, the winding roller used for winding is a large tube core paper tube winding.

[0009] Furthermore, the anti-low temperature auxiliary agent is a vinyl acetate-ethylene copolymer emulsion with a solid content of ≥55%, a viscosity of 2000, a pH value of 5.2, and a dilution stability of 1.2%, mixed with acrylic acid ester in a mass ratio of 1:1.

[0010] Due to the adoption of the above-mentioned technical solution, the present invention has the following beneficial effects: The invention discloses a method for preparing a high-barrier and low-temperature-resistant PVDC film, which has a simple structure, is easy to assemble, and has a low production cost. By setting a low-temperature metal flattening roller, the curing effect of the adhesive is improved when the adhesive is bonded to the film, thereby improving the low-temperature performance of the film after bonding.

[0011] The anti-low temperature additive in the glue makes the film have better low temperature performance. At the same time, the presence of ether bonds in the glue further makes the adhesive have better bonding effect at low temperatures. By using vinyl acetate-ethylene copolymer emulsion and acrylate in a specific proportion, the interaction force of the molecular chains is changed, making the molecular chains more flexible, further improving the softness of the casing film under low temperature conditions, that is, enhancing its low temperature resistance. Therefore, under low temperature conditions, the film added with glue is softer and has better low temperature resistance. DETAILED DESCRIPTION

[0012] A method for preparing a high-barrier low-temperature-resistant PVDC film, the specific steps are as follows: (1) Using a slitting machine to cut the double-layer PVDC film along the edge of the film, the double-layer PVDC film is separated into two rolls of single-layer PVDC film, roll a and roll b; (2) Fix the separated a and b film rolls on the unwinder A and unwinder B of the solvent-free laminating machine respectively to ensure that the film rolls fit the equipment; (3) The glue liquid is a mixture of castor oil polyether polyol and polycyanate in a mass ratio of 70-90:100, and then 2-5wt% of a vinyl acetate-ethylene copolymer emulsion with a solid content of ≥55%, a viscosity of 2000, a pH value of 5.2, and a dilution stability of 1.2% and an anti-low temperature additive mixed with acrylate in a mass ratio of 1:1 is added. The glue liquid is sprayed from the coating unit end, and passes through a fixed roller, a metering roller, a transfer roller, a coating roller, and a coating pressure roller in sequence to coat the glue liquid on the inner layer of the a and b film rolls; the machine speed is adjusted to 50-80m / min for lamination, and the temperature of the laminating roller is set to 75-80°C. After lamination, the film roll is kept flat and wrinkle-free during the winding process through a metal flattening roller whose roller surface material is stainless steel metal material, and the temperature of the metal flattening roller is set to 10-15°C; (4) After the composite flattening in step (3), the film is rolled up using a large-tube paper tube winding roller, and then placed in a 38°C aging box for aging. After aging for 24 hours, the film roll needs to be rewound, and the outer film is folded to the inside of the paper tube to drive out the bubbles. The rewound film roll is then placed back in a 38°C aging box for aging for 24 hours, and then the film roll is taken out to obtain the product. Example 1

[0013] (1) Using a slitting machine to cut the double-layer PVDC film along the edge of the film, the double-layer PVDC film is separated into two rolls of single-layer PVDC film, a and b; (2) Fix the separated a and b film rolls on the unwinder A and unwinder B of the solvent-free laminating machine respectively to ensure that the film rolls fit the equipment; (3) A glue solution prepared by mixing castor oil polyether polyol and polycyanate in a mass ratio of 70:100 and then adding 2wt% of vinyl acetate-ethylene copolymer emulsion with a solid content of ≥55%, a viscosity of 2000, a pH value of 5.2, and a dilution stability of 1.2% and acrylate in a mass ratio of 1:1, which is an anti-low-temperature additive, is sprayed from the coating unit end, and is sequentially passed through a fixed roller, a metering roller, a transfer roller, a coating roller, and a coating pressure roller, and then coated on the inner layers of the a and b film rolls; the machine speed is adjusted to 50 m / min for lamination, the temperature of the laminating roller is set to 75°C, and after lamination, the film roll passes through a metal flattening roller made of stainless steel, and the temperature is set to 10°C, so that the film roll remains flat and wrinkle-free during the winding process; (4) After the composite flattening in step (3), the film is rolled up using a large-tube paper tube winding roller, and then placed in a 38°C aging box for aging. After aging for 24 hours, the film roll needs to be rewound, and the outer film is folded to the inside of the paper tube to drive out the bubbles. The rewound film roll is then placed back in a 38°C aging box for aging for 24 hours, and then the film roll is taken out to obtain the product. Example 2

[0014] The glue solution is composed of castor oil polyether polyol and polycyanate in a mass ratio of 80:100 and 2wt% of anti-low temperature additive. The machine speed is 55m / min, the temperature of the composite roller is set to 77°C, the temperature of the metal flattening roller is set to 15°C, and the other conditions are the same as Example 1. Example 3

[0015] The glue solution is composed of castor oil polyether polyol and polycyanate in a mass ratio of 90:100 and 2wt% of anti-low temperature additive. The machine speed is 65m / min, the temperature of the composite roller is set to 79°C, the temperature of the metal flattening roller is set to 15°C, and the other conditions are the same as in Example 1. Example 4

[0016] The glue solution is composed of castor oil polyether polyol and polycyanate in a mass ratio of 70:100 and 5wt% of anti-low temperature additive is added. The machine speed is 70m / min, the temperature of the composite roller is set to 76°C, the temperature of the metal flattening roller is set to 15°C, and the other conditions are the same as Example 1. Example 5

[0017] The glue solution is composed of castor oil polyether polyol and polycyanate in a mass ratio of 80:100 and 5wt% of anti-low temperature additive. The machine speed is 75m / min, the temperature of the composite roller is set to 80°C, the temperature of the metal flattening roller is set to 15°C, and the other conditions are the same as Example 1. Example 6

[0018] The glue solution is composed of castor oil polyether polyol and polycyanate in a mass ratio of 70:100 and 5wt% of anti-low temperature additive. The machine speed is 80m / min, the temperature of the composite roller is set to 80°C, the temperature of the metal flattening roller is set to 15°C, and the other conditions are the same as Example 1.

[0019] Comparative Example 1 The glue solution is composed of castor oil polyether polyol and polycyanate in a mass ratio of 70:100 and 8wt% of anti-low temperature additive. The machine speed is 55m / min, the temperature of the composite roller is set to 80°C, the temperature of the metal flattening roller is set to 15°C, and the other conditions are the same as Example 1.

[0020] Comparative Example 2 The glue solution is composed of castor oil polyether polyol and polycyanate in a mass ratio of 60:100 and 2wt% of anti-low temperature additive. The machine speed is 55m / min, the temperature of the composite roller is set to 80°C, the temperature of the metal flattening roller is set to 15°C, and the other conditions are the same as Example 1.

[0021] Comparative Example 3 The glue solution is composed of castor oil polyether polyol and polycyanate in a mass ratio of 70:100. The machine speed is 55 m / min, the temperature of the composite roller is set to 80° C., the temperature of the metal flattening roller is set to 15° C., and the other conditions are the same as those in Example 1.

[0022] Comparative Example 4 Untreated PVDC film.

[0023] Take two meters of the products obtained in Examples 1-6 and Comparative Examples 1-4, cut them into square sheets with a 14cm*14cm cutter at room temperature of 23°C and humidity of 40%, put the square films into a refrigerator at 0°C one by one with an interval of 5 minutes. After 30 minutes, take out the films one by one and test them with a film rubbing tester to obtain the results in Table 1.

[0024] It can be seen from the results in Table 1 that the films prepared by the adhesives of Examples 1-6, which are composed of castor oil polyether polyol and polycyanate in a mass ratio of 70-90:100 and 2-5wt% of a low-temperature resistance additive, have excellent low-temperature performance, a small number of holes with small diameters after rubbing, a low number of bubbles generated, and good barrier properties. Among them, the performance of Example 6 is the best, with the lowest number of holes and bubbles.

[0025] Table 1 Test results

[0026] The parts of the present invention that are not described in detail are prior art. It is obvious to those skilled in the art that the present invention is not limited to the details of the above-mentioned exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention; therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and it is intended that all changes that fall within the meaning and scope of equivalent elements are included in the present invention.

Claims

1. A method for preparing a high-barrier, low-temperature-resistant PVDC film, comprising: Follow these steps: (1) Using a slitting machine to cut the double-layer PVDC film along the edge of the film, the double-layer PVDC film is separated into two rolls of single-layer PVDC film, roll a and roll b; (2) Fix the separated a and b film rolls on the unwinder A and unwinder B of the solvent-free laminating machine respectively to ensure that the film rolls fit the equipment; (3) Spray the glue liquid from the coating unit end, and then pass through the fixed roller, metering roller, transfer roller, coating roller, and coating pressure roller in sequence to coat the glue liquid onto the inner layer of the film rolls a and b; adjust the machine speed to 50-80 m / min for lamination, set the laminating roller temperature to 75-80 °C, and pass through the metal flattening roller after lamination; (4) After the composite flattening in step (3), the film roll is rolled up and placed in a 38°C curing box for curing. After curing for 24 hours, the film roll needs to be rewound, and the outer film is folded to the inside of the paper tube to drive out the bubbles. The rewound film roll is then placed back in a 38°C curing box for curing for 24 hours, and then the film roll is taken out to obtain the product.

2. The method for preparing a high-barrier low-temperature-resistant PVDC film according to claim 1, characterized in that: The glue solution is a mixture of castor oil polyether polyol and polycyanate at a mass ratio of 70-90:100, and 2-5% of a low temperature resistance additive is added.

3. The method for preparing a high-barrier low-temperature-resistant PVDC film according to claim 1, characterized in that: The roller surface material of the metal flattening roller is stainless steel, so that the film roll remains flat and wrinkle-free during the winding process. The temperature of the metal flattening roller is set to 10-15°C.

4. The method for preparing a high-barrier low-temperature-resistant PVDC film according to claim 1, characterized in that: The winding roller used for the winding is a large-tube-core paper tube winding.

5. The method for preparing a high-barrier low-temperature-resistant PVDC film according to claim 2, characterized in that: The anti-low temperature auxiliary agent is a mixture of vinyl acetate-ethylene copolymer emulsion with a solid content of ≥55%, a viscosity of 2000, a pH value of 5.2, and a dilution stability of 1.2% and acrylic acid ester in a mass ratio of 1:1.

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