Plastic film, its continuous production method and use

Abstract

The application discloses a plastic film and a continuous production method and application thereof, and relates to the technical field of film production. The film comprises 3-10 UV light curing processes, 1-3 EB curing processes and 0-3 UV light curing processes in sequence. The continuous production method of the film can significantly improve the film production speed, and meanwhile, guarantees that the coating has excellent scratch resistance, hardness and high light surface performance.

Description

Technical Field

[0001] This invention relates to the field of film production technology, and in particular to a plastic film, its continuous production method, and its application. Background Technology

[0002] The bottlenecks of UV curing technology mainly lie in material adaptability, equipment performance and cost, application scenario limitations, and environmental safety. UV-cured coating materials require the addition of specific photoinitiators, some of which have stability issues and may affect the final product performance. Furthermore, UV light has limited penetration and is color-sensitive, making it difficult to cure thick or dark-colored materials, leading to incomplete curing of the underlying layers. In multi-layer curing, structural defects may result from uncured underlying layers. Moreover, controlling the uniformity of UV irradiation light source is difficult, easily leading to uneven curing. UV equipment has high energy consumption, resulting in significant long-term operating costs.

[0003] EB radiation processing has significant advantages and broad application prospects, and can be integrated with various sectors of the national economy to form new industries or new economic growth points. However, its engineering application is restricted by factors such as the advanced nature of the technology, high industrial application costs, difficulty in controlling the stability of equipment and process technology, and the limited availability of compatible coating materials. Furthermore, due to the complex manufacturing process of plastic films, it is difficult to obtain plastic films with excellent properties and suitable for thermoforming using UV curing or EB curing methods.

[0004] Therefore, there is an urgent need to develop a continuous production method for plastic film, so that the produced plastic film can be applied to various electrical appliance panels and interior cabinet panels, and can be vacuum formed, while having high gloss, high hardness and excellent scratch resistance. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the present invention proposes a plastic film, a continuous production method thereof, and its application.

[0006] This invention provides a continuous production method for plastic film, which includes 3-10 stages of UV curing process, 1-3 stages of EB curing process and 0-3 stages of UV curing process.

[0007] Furthermore, the continuous production method for the plastic film specifically includes the following steps:

[0008] S1: The UV curing process is carried out in 3-10 stages. UV-curable resin material is coated onto the surface of the plastic film substrate, with each coating being 2-4 micrometers thick. A surface cured layer is formed through UV curing. The UV curing energy is 200-300 mJ / cm². 2 ;

[0009] S2: Coat once with EB curing resin material to form a thin layer of resin of 5-10 micrometers, and cure it under EB curing conditions, wherein the EB curing voltage is 110-150keV and the dosage is 3-30KGy, and the EB curing process is carried out in 1-3 stages.

[0010] S3: In addition to the EB curing coating, apply the UV curing layer 0-3 times according to the UV curing process in step S1, and perform the 0-3 segment UV curing process.

[0011] The coating process in UV curing and EB curing can be performed by roller coating, for example, using a micro-grooved roller or an anilox roller.

[0012] Currently, the industry struggles to achieve continuous production using a combination of these two methods, and no other company has yet introduced EB radiation processing technology for coating curing and polymer crosslinking modification of plastic films. This invention utilizes a gradient curing technology combining EB irradiation and UV technology to create a dense crosslinked network structure and interactions between different layers in the cured coating. This solves common industry technical problems such as the conflict between surface hardness and vacuum forming, and overcomes bottlenecks such as the difficulty of achieving high-gloss surfaces with EB irradiation.

[0013] Step S1 of this invention, through gradient curing, can improve the hardness and scratch resistance of the product, while solving the coating stretching problem in vacuum forming applications. Step S2 utilizes EB curing, firstly curing the EB curing resin material, and secondly, allowing the incompletely cured coating material from step S1 to fully cure together with the EB coating under the action of an electron beam, generating a cross-linking reaction and improving interlayer adhesion. Step S3, while ensuring hardness, further optimizes gloss and enriches the appearance. This invention, through a specific combination of UV curing and EB curing, produces a plastic film that can be applied to various electrical appliance panels and interior cabinet panels, and can be vacuum formed, while possessing high gloss, high hardness, and excellent scratch resistance.

[0014] The UV-cured layer can improve the surface adhesion of the base film and increase its surface hardness. Furthermore, due to the layered coating of the UV-cured layer, the color of each layer can be adjusted by computer design at each stage, resulting in a richer and more layered surface and improving the appearance of the decorative panel.

[0015] The UV curing process is slower than the EB irradiation curing process and is difficult to match. This invention prepares a thin UV layer in multiple stages, which can ensure sufficient UV curing and make the UV curing layer adapt to the EB irradiation curing process, thereby improving production speed.

[0016] Further, the curing time of each UV-curable resin layer in step S1 is 0.2-0.5 seconds, the EB curing time in step S2 is 0.03-0.5 seconds, and the curing time of each UV-curable resin layer in step S3 is 0.2-0.5 seconds.

[0017] Furthermore, the conveying speed of the plastic film is 20-50 m / min, such as 20, 25, 30, 35, 40, 45, 50 m / min.

[0018] Furthermore, in step S1, the thickness of the UV-cured surface resin layer is less than or equal to 30 micrometers.

[0019] Further, the UV-curable resin material, by weight, comprises the following components: 30-50 parts of bifunctional aliphatic polyurethane resin, such as 30, 35, 40, 45, or 50 parts; 20-40 parts of trifunctional aliphatic polyurethane resin, such as 20, 25, 30, 35, or 40 parts; 0-10 parts of monofunctional active monomer, such as 0, 1, 2, 4, 6, 8, or 10 parts; 5-10 parts of bifunctional active monomer, such as 5, 6, 7, 8, 9, or 10 parts; 1-2 parts of photoinitiator, such as 1, 1.2, 1.4, 1.5, 1.8, or 2 parts; 0.2-0.5 parts of additives, such as 0.2, 0.3, 0.4, or 0.5 parts; 0-10 parts of solvent, such as 0, 5, 8, or 10 parts; and 0-10 parts of ink, such as 0, 2, 4, 5, 6, 7, 8, 9, or 10 parts.

[0020] Furthermore, the ink is a UV-curable ink, preferably a UV-curable ink with high transparency, such as transparent yellow or light- and heat-resistant red.

[0021] Furthermore, pigments can be added to the UV coating resin applied over the EB coating resin.

[0022] Furthermore, the UV-curable resin material is prepared by blending.

[0023] Furthermore, the bifunctional aliphatic polyurethane resin includes, but is not limited to, any one or more of the following: 6148J-75, DR-U241, DR-U377, 6113 from Taiwan Chang Hsing Corporation, and CN966J75, CN9001, CN964, and CN965 from Sartoma.

[0024] Furthermore, the trifunctional aliphatic polyurethane resin includes, but is not limited to, any one or more of DR-U010 and DR-U265 from Changxing Company, and CN989 and CN8009 from Sartoma.

[0025] Furthermore, the monofunctional active monomers include, but are not limited to, any one or more of THFA (tetrahydrofurfuryl acrylate), IBOA (isobornyl acrylate), CTFA (cyclotrimethylolpropane formal acrylate), BZA (benzyl acrylate), and EOEOEA (ethoxyethoxyethyl acrylate).

[0026] Furthermore, the bifunctional active monomers include, but are not limited to, any one or more of HDDA (1,6-hexanediol diacrylate), TEGDA (triethylene glycol diacrylate), and TPGDA (tripropylene glycol diacrylate).

[0027] Furthermore, the photoinitiator includes, but is not limited to, any one or more of 184 (hydroxycyclohexylphenyl ketone), 1173 (hydroxydimethyl acetophenone), and TPO (2,4,6-trimethylbenzoyl-diphenylphosphine oxide).

[0028] Furthermore, the additives include, but are not limited to, any one or more of the following: defoamer BYK088, leveling agent DC57, wax emulsion AQUACER513, BYK Chemical's 361N and 3560, and TIGAO's TEGO 270, TEGO 920, and TEGO 2100.

[0029] Furthermore, the solvent includes, but is not limited to, any one or more of ethyl acetate, butyl acetate, butanone, isopropanol, and ethyl acetate.

[0030] Further, the EB-cured resin material comprises, by weight, the following components: 30-90 parts of vinyl-terminated polyurethane prepolymer, such as 30, 35, 40, 45, 50, 60, 70, 80, or 90 parts; 10-40 parts of reactive diluent, such as 10, 15, 20, 25, 30, 35, or 40 parts; and 0.5-15 parts of additives, such as 0.5, 1, 2, 4, 8, 10, 12, or 15 parts.

[0031] Furthermore, the vinyl-terminated polyurethane prepolymer is selected from one or both of prepolymer A and prepolymer B;

[0032] The structure of the prepolymer A is as follows:

[0033] ;

[0034] in, ;

[0035] The structure of the prepolymer B is as follows:

[0036] .

[0037] Preferably, the vinyl-terminated polyurethane prepolymer is selected from a composition of prepolymer A and prepolymer B in a mass ratio of (0.4-2.5):1.

[0038] Furthermore, the reactive diluent is an acrylate monomer containing a double bond, wherein the acrylate monomer is selected from any one or more of monofunctional acrylate monomers, difunctional acrylate monomers, or polyfunctional acrylate monomers.

[0039] The monofunctional acrylate monomers include, but are not limited to, any one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, isobornyl acrylate, and isobornyl methacrylate; the difunctional acrylate monomers include, but are not limited to, neopentyl glycol diacrylate, hexanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, tripropylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, and neopentyl glycol diacrylate. The polyfunctional acrylate monomers include, but are not limited to, trimethylolpropane triacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, dipentaerythritol hexaacrylate, propoxylated trimethylolpropane triacrylate, propoxylated glycerol triacrylate, propoxylated glycerol trimethacrylate, triallyl triisocyanate, and trimethylallyl triisocyanate.

[0040] Furthermore, the additive is any one or more of the following: dispersant, leveling agent, defoamer, antioxidant, adhesion promoter, heat stabilizer, filler, or pigment.

[0041] The dispersant includes, but is not limited to, any one or more of N,N'-ethylene bis-stearamide, Efka EFKA-4560, BYK-110, BYK-111, BYK-112, and BYK-116; the leveling agent includes, but is not limited to, any one or more of BYK-350, BYK331, BYK333, and AFCONA3034; the defoamer includes, but is not limited to, any one or more of BYK-1790, BYK052, BYK055, and AFCONA2022; the antioxidant includes, but is not limited to, 1010; the adhesion promoter includes, but is not limited to, any one or more of silane coupling agents, titanate silane coupling agents, Dow Corning 6030, and FM135; the heat stabilizer includes, but is not limited to, any one or more of rare earth / calcium / zinc composite heat stabilizer, dibutyltin dilaurate, zinc stearate, aluminum stearate, and aluminum distearate; the filler includes, but is not limited to, ultraviolet-absorbing inorganic particles; and the pigment includes, but is not limited to, titanium dioxide.

[0042] Furthermore, the preparation method of the prepolymer A includes the following steps:

[0043] S1: Preparation of N,N-dihydroxyethyl-3-aminopropionic acid methyl ester monomer 1;

[0044] S2: Add 1 mol of tetra-armed polyethylene glycol, 4.1-4.4 mol of N,N-dihydroxyethyl-3-aminopropionic acid methyl ester monomer 1 and 0.1-0.6 mol of p-toluenesulfonic acid to a four-necked flask equipped with a water separator, a feeding funnel and a mechanical stirrer. Then heat the mixture to 130-150℃ and react for 3.5-5 hours to obtain a pale yellow oily compound 2.

[0045] S3: Using dry polytetrahydrofuran as solvent, 1 mol of compound 2 was added to a three-necked round-bottom flask. After installing a stirrer and thermometer, N2 was introduced for gas protection, and the mixture was stirred at 45-60℃ for 25-32 min. Subsequently, the temperature was raised to 70-84℃, and 4.1-4.4 mol of isophorone diisocyanate (IPDI) was added to the flask. The temperature was then raised to 85-90℃, and 0.05-0.1 mol of dibutyltin dilaurate catalyst (DBTDL) was added. The mixture was reacted under mechanical stirring for 1.5-2 h to obtain polyurethane intermediate 3.

[0046] S4: Add 2.1-2.2 mol of diisocyanate to the flask and react at 78-85℃ for 2.5-4 h with mechanical stirring;

[0047] S5: Adjust the temperature to 50-60℃ and react with 0.9-1.3 mol of hydroxyethyl methacrylate (HEMA) for 1.5-3 hours to obtain prepolymer A.

[0048] In step S4, the diisocyanate is any one or more of the following: dicyclohexane 4,4'-diisocyanate, 1,4-butyl diisocyanate, 1,4-cyclohexyl diisocyanate, o-toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, N,N'-2-tris(6-isocyanate-hexyl)iminodiacarbonate diamide, and diisocyanate.

[0049] The molecular weight of each arm of the four-arm polyethylene glycol is 2000-20000, such as 2000, 5000, 10000, 20000.

[0050] The preparation method of N,N-dihydroxyethyl-3-aminopropionic acid methyl ester monomer 1 includes the following steps:

[0051] In a four-necked flask equipped with helium protection, a condenser, and mechanical stirring, 1.0-1.5 mol of methyl acrylate and 1.01-1.51 mol of diethanolamine were added to 200-250 mL of methanol as solvent. The mixture was stirred for 28-35 min at room temperature under nitrogen protection, and then heated to 38-45℃ for 4-4.5 h. The methanol was removed by distillation to obtain colorless and transparent N,N-dihydroxyethyl-3-aminopropionic acid methyl ester monomer 1. The reaction formula is as follows:

[0052] .

[0053] Furthermore, the preparation method of the prepolymer B includes the following steps:

[0054] 1 mol of four-arm polyethylene glycol isocyanate and 4.1-4.4 mol of hydroxyethyl methacrylate (HEMA) were added to a four-necked flask equipped with a water separator, a feeding funnel, and a mechanical stirrer. The mixture was then reacted at 58-65°C for 3.5-5 h to obtain prepolymer B. The reaction formula is as follows:

[0055] ;

[0056] The molecular weight of each arm of the four-arm polyethylene glycol isocyanate is 2000-20000, such as 2000, 5000, 10000, 20000.

[0057] Furthermore, the preparation method of the EB-cured resin material includes the following steps:

[0058] Weigh out the vinyl-terminated polyurethane prepolymer, reactive diluent, and additives according to the specified weight, mix them evenly, and disperse them in a high-speed disperser at 2800-3500 rpm for 70-85 minutes to obtain the coating composition.

[0059] The present invention also provides a plastic film produced by the continuous production method described above.

[0060] The present invention also provides the application of the aforementioned plastic film in the panels of household appliances and the panels of indoor cabinets.

[0061] In summary, compared with the prior art, the present invention achieves the following technical effects:

[0062] (1) The continuous production method provided by the present invention enables the film to be easily transported through the conveying device. By conveying the film through the UV curing area, the coating area and the EB curing area, the film can move quickly on the production line, improving production efficiency. Compared with the original production method which requires multiple workshops and multiple equipment to complete, the present invention connects the various curing processes, eliminating the need for additional transportation, and forms a continuous production mode. The film can move continuously and quickly on the production line, thus greatly improving production efficiency.

[0063] (2) The continuous production method provided by the present invention can ensure that the plastic film can be applied to various electrical appliance panels and indoor cabinet panels, and can be vacuum formed. It also has high gloss, high hardness and excellent scratch resistance. Detailed Implementation

[0064] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0065] Example

[0066] The present invention will be further illustrated below with reference to specific embodiments and comparative embodiments. The following specific embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments, and are not in particular limited to the types of raw materials used in the following specific embodiments.

[0067] I. The sources of raw materials for the examples and comparative examples are as follows:

[0068] Unless otherwise specified, the raw materials used in the embodiments and comparative examples of this invention are all commercially available.

[0069] The preparation method of prepolymer A used in the EB curing resin material in the embodiments and comparative examples of the present invention is as follows:

[0070] S1: Add 1 mol of four-arm polyethylene glycol (molecular weight of each arm is 2000), 4.1 mol of N,N-dihydroxyethyl-3-aminopropionic acid methyl ester monomer 1 and 0.3 mol of p-toluenesulfonic acid to a four-necked flask equipped with a water separator, a feeding funnel and a mechanical stirrer. Then heat the mixture to 140°C and react for 4 hours to obtain a pale yellow oily compound 2.

[0071] S2: Using dry polytetrahydrofuran as solvent, 1 mol of compound 2 was added to a three-necked round-bottom flask. After installing a stirrer and thermometer, N2 was introduced for gas protection, and the mixture was stirred at 55°C for 30 min. Subsequently, the temperature was raised to 80°C, and 4.2 mol of isophorone diisocyanate (IPDI) was added to the flask. The temperature was then raised to 85°C, and 0.08 mol of dibutyltin dilaurate (DBTDL) was added as a catalyst. The mixture was reacted under mechanical stirring for 1.5 h to obtain polyurethane intermediate 3.

[0072] S3: Add 2.1 mol of isophorone diisocyanate (IPDI) to the flask and react at 85°C for 3 h with mechanical stirring;

[0073] S4: Adjust the temperature to 55℃ and react with 1 mol of hydroxyethyl methacrylate (HEMA) for 2 h to obtain prepolymer A;

[0074] The preparation method of N,N-dihydroxyethyl-3-aminopropionic acid methyl ester monomer 1 is as follows:

[0075] In a four-necked flask equipped with helium protection, a condenser, and a mechanical stirrer, 1 mol of methyl acrylate and 1.01 mol of diethanolamine were added to 200 mL of methanol as solvent. The mixture was stirred for 30 min at room temperature and under nitrogen protection, and then heated to 40 °C for 4 h. Methanol was removed by distillation to obtain colorless and transparent N,N-dihydroxyethyl-3-aminopropionic acid methyl ester monomer 1.

[0076] The preparation method of prepolymer B used in the EB curing resin material in the embodiments and comparative examples of the present invention is as follows:

[0077] 1 mol of four-arm polyethylene glycol isocyanate (with a molecular weight of 5000 per arm) and 4.1-4.4 mol of hydroxyethyl methacrylate (HEMA) were added to a four-necked flask equipped with a water separator, a feeding funnel, and a mechanical stirrer. The mixture was reacted at 60°C for 4 h to obtain vinyl-terminated polyurethane prepolymer B.

[0078] The preparation methods of the EB-cured resin materials in the embodiments and comparative examples of the present invention are as follows:

[0079] Weigh out prepolymer A and prepolymer B by weight and mix to obtain 50 g of vinyl-terminated polyurethane prepolymer. Add 10 g of hydroxypropyl acrylate, 10 g of hexanediol diacrylate, 10 g of trimethylolpropane triacrylate as an active diluent, and 1 g of N,N'-ethylene bis-stearamide, 2 g of BYK331, and 2 g of BYK-1790 additives and mix thoroughly. Disperse in a high-speed disperser at 3000 rpm for 80 minutes to obtain EB-cured resin material.

[0080] The UV-curable resin materials of the embodiments and comparative examples of the present invention are obtained by blending. The UV-curable resin materials of the embodiments and comparative examples include the following components: 40 parts by weight of bifunctional aliphatic polyurethane resin 6148J-75, 30 parts by weight of trifunctional aliphatic polyurethane resin DR-U010, 5 parts by weight of bifunctional reactive monomer (reactive diluent) TPGDA, 1 part by weight of photoinitiator TPO (ethyl 2,4,6-trimethylbenzoylphenylphosphonate), 0.1 parts by weight of defoamer BYK088, 0.2 parts by weight of leveling agent DC57, 0.1 parts by weight of wax emulsion AQUACER 513, and 5 parts by weight of ethyl acetate solvent.

[0081] II. Performance Testing Methods

[0082] (1) Scratch resistance: The test standard is ISO1518-2:1992. The diameter of the steel needle and steel ball used in the test is 1 mm. An electric scratch tester is used to perform a unidirectional scratch test on the coating surface at a speed of 20 mm / s. The scratch length is 50 mm. The test is repeated 3-5 times and the average value is taken. The load when the steel needle is scratched is continuously increased. The load when the coating is first scratched by the steel needle is recorded as an indicator of the coating's scratch resistance. The greater the load, the better the scratch resistance.

[0083] (2) Hardness performance test: The test shall be conducted in accordance with the standard GB / T 17657-2013.

[0084] (3) High gloss performance test: The test shall be conducted in accordance with the standard GB / T 8807-1988.

[0085] Table 1. Technical solutions and effects of the embodiments and comparative examples

[0086]

[0087] The film transport speed was tested under the following curing conditions: UV curing conditions: energy 220 mJ / cm 2 Single layer thickness 3 μm, total thickness 15 μm; EB curing conditions: voltage 120 KeV, dosage 20 KGy, prepolymer A / B mass ratio 7:3; Second UV curing conditions: energy 220 mJ / cm².2 A curing experiment was conducted with a single layer thickness of 3 μm.

[0088] Table 2. Analysis of the impact of conveying speed on performance

[0089]

[0090] When the production process conveying speed is below 20 m / min, flow marks are likely to occur; above 50 m / min, the curing effect begins to decrease and become incomplete, the hardness and scratch resistance gradually weaken, and bubbles and shrinkage cavities appear.

[0091] In Examples 1-5, the films were prepared using the specific production method of this application. The resulting film coatings have excellent scratch resistance, reaching 2000 or higher, and also have high gloss performance, reaching 87 or higher. Furthermore, the film prepared by the production method of this application not only enables continuous production but also significantly improves the production speed, which is beneficial for industrial production.

[0092] Comparative Examples 1 and 2 are compared with Example 5. Comparative Example 1 uses only UV curing to prepare the film. The curing rate of UV curing is generally maintained at 70%, which is not complete curing. Using only one method will affect the final hardness, scratch resistance and other properties, making the hardness and scratch resistance unstable. Comparative Example 2 uses only EB curing to prepare the film. EB curing can reach 100%. However, if each layer is cured with EB, it will not only affect the interlayer adhesion of the coating, but also easily cause delamination when the product is stretched during vacuum forming. It will also increase the production cost.

[0093] Based on the test data in Tables 1 and 2, it can be seen that the thin films produced by the preparation methods of Examples 1-5 have significant advantages over the comparative examples and can effectively meet the high standards of customers and the market.

[0094] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for continuous production of a plastic film, characterized by, comprises 3-10 UV light curing processes, 1-3 EB curing processes and 0-3 UV light curing processes in sequence; comprises the following steps: S1: UV light curing process is carried out in 3-10 sections, UV light curing resin material is coated to the surface of plastic film substrate, the coating of each coating is 2-4 microns, and the surface layer curing layer is formed by UV light curing, wherein the energy of UV light curing is 200-300 mJ / cm 2 ; S2: coating EB curing resin material once to form a 5-10 micron thin layer resin, curing under EB curing condition, wherein the EB curing voltage is 110-150 KeV, the dose is 3-30 KGy, and the EB curing process is performed for 1-3 times; S3: coating UV light curing layer outside the EB curing coating according to the UV light curing process in step S1 for 0-3 times, and performing 0-3 UV light curing processes; The UV light curing resin material consists of the following components by weight: dual functional aliphatic polyurethane resin 30-50 parts trifunctional aliphatic polyurethane resin 20-40 parts monofunctional active monomer 0-10 parts dual functional active monomer 5-10 parts photoinitiator 1-2 parts auxiliary agent 0.2-0.5 parts solvent 0-10 parts; The EB curing resin material consists of the following components by weight: vinyl-terminated polyurethane prepolymer 30-90 parts active diluent 10-40 parts auxiliary agent 0.5-15 parts; The vinyl-terminated polyurethane prepolymer is selected from prepolymer B, and the structure of the prepolymer B is as follows: ； The conveying speed of the plastic film is 20 50 m / min.

2. The continuous production process according to claim 1, characterized in that, The curing time of each layer of UV light curing resin layer in step S1 is 0.2-0.5 seconds, the EB curing time in step S2 is 0.03-0.5 seconds, and the curing time of each layer of UV light curing resin layer in step S3 is 0.2-0.5 seconds.

3. The continuous production process according to claim 1, characterized in that, The thickness of the UV light curing surface resin layer in step S1 is less than or equal to 30 microns.

4. A plastic film, characterized by obtained by the continuous production method according to any one of claims 1-3.

5. The application of the plastic film according to claim 4 in household appliance panel and indoor cabinet panel.

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