Electron beam curing-based composite films and their preparation methods

Abstract

This invention discloses a composite film based on electron beam curing and its preparation method, relating to the field of flexible materials technology. The composite film includes a substrate, a transition layer and an EB coating sequentially disposed on the substrate; the transition layer is obtained by curing a transition coating, which comprises the following components by weight: 40-60 parts acrylic resin; 15-25 parts cellulose acetate butyrate resin; 3-10 parts isopropanol; 10-20 parts n-propyl acetate; 1-5 parts inorganic pigment; and 1-6 parts first additive; the EB coating is obtained by curing the EB coating. Implementing this invention can improve the fineness of decorative patterns and the yellowing resistance of the composite film.

Description

Technical Field

[0001] This invention relates to the field of flexible materials technology, and in particular to a composite film based on electron beam curing. Background Technology

[0002] Functional composite films are a type of functional composite material that combines specific functions. To impart specific functions (such as anti-fingerprint and anti-static properties) and certain decorative effects, a coating is often prepared on its surface. For some composite films with special textures, embossing or texturing treatments are also required.

[0003] There are generally three curing methods for coatings on composite film surfaces. The first is thermosetting. Thermosetting processes involve high temperatures, making them unsuitable for heat-sensitive substrates, and the curing time is very long (from several minutes to tens of minutes). After softening and texturing, a second curing is required, resulting in poor texture fineness. Furthermore, thermosetting processes release solvents during heating, which is environmentally unfriendly, and thermo-cured coatings are often prone to yellowing. The second curing process is ultraviolet (UV) curing. While UV curing has a relatively short curing time (within 10 seconds) and can achieve more precise texturing, it requires the introduction of photoinitiators. Residual photoinitiators, i.e., incompletely cured unsaturated bonds, can cause yellowing of the coating. Secondly, UV curing does not achieve sufficient curing depth, requiring multiple coating and curing cycles, extending the processing time. The third curing process is electron beam (EB) curing. EB curing is a novel curing technology that cures oligomers containing unsaturated carbon-carbon double bonds under electron beam irradiation. EB curing offers advantages such as fast curing speed (<1s), no heat generation, no need for initiators, environmental friendliness, and resistance to yellowing. However, EB-cured coatings have relatively poor adhesion to some substrates and lower strength. This poor strength can also reduce the fineness of decorative patterns to some extent. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a composite film based on electron beam curing, which has a high degree of fineness of texture, is resistant to yellowing, and is environmentally friendly.

[0005] Another technical problem that this invention aims to solve is to provide a method for preparing a composite film based on electron beam curing.

[0006] To solve the above-mentioned technical problems, the present invention provides a composite film based on electron beam curing, which includes a substrate, a transition layer and an EB coating sequentially disposed on the substrate;

[0007] The transition layer is obtained by curing a transition coating, which comprises the following components in parts by weight:

[0008]

[0009] The EB coating is obtained by curing EB paint.

[0010] As an improvement to the above technical solution, the glass transition temperature of the acrylic resin is 90-100℃, and the molecular weight is 100,000-120,000.

[0011] The surface tension of the transition coating is ≥40mN / m.

[0012] As an improvement to the above technical solution, the first auxiliary agent comprises, by weight:

[0013] Dispersant 1.0-1.5 parts;

[0014] 0.5-1.5 parts wetting agent;

[0015] The dispersant selected is BYK-9076 and / or Dow Corning 6030;

[0016] The wetting agent is selected from BYK-220S and / or BYK-P104s.

[0017] As an improvement to the above technical solution, the EB coating comprises the following components in parts by weight:

[0018]

[0019] As an improvement to the above technical solution, the monomer is selected from one or more of 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, cyclotrimethylolpropane methyl acetal acrylate, isodecanol acrylate, and ethoxylated trimethylolpropane triacrylate.

[0020] The filler is selected from one or more of the following: light calcium carbonate, fumed silica, barium sulfate, calcined kaolin, talc, and titanium dioxide.

[0021] The second additive is selected from one or more of the following: silane coupling agent, titanate coupling agent, surfactant, defoamer, ultraviolet absorber, antistatic particles, and antifingerprint agent.

[0022] As an improvement to the above technical solution, the second auxiliary agent comprises, by weight:

[0023] 0-2 parts of ultraviolet absorber;

[0024] 0-2 parts of defoamer;

[0025] The defoamer is selected from BYK-025 and / or BYK-028;

[0026] The ultraviolet absorber is selected UV-326, UV-531, One or more of UV-1577.

[0027] As an improvement to the above technical solution, the substrate is selected from one or more of PP, PET, PE, PETG, PVC, PS, PMMA, and bleached kraft paper.

[0028] Accordingly, the present invention also discloses a method for preparing an electron beam-cured composite film, which is used to prepare the above-mentioned electron beam-cured composite film, comprising:

[0029] Provide substrate

[0030] A transition coating is applied to the surface of the substrate to form a transition layer;

[0031] EB coating is applied to the transition layer;

[0032] Electron beam curing is performed simultaneously with embossing to obtain the finished composite film.

[0033] As an improvement to the above technical solution, the coating amount of the transition coating is 1-5 g / m². 2 The coating amount of the EB coating is 10-50 g / m². 2 ;

[0034] The energy of electron beam curing is 100-500 keV, and the radiation dose is 3-10 mR.

[0035] Implementing this invention has the following beneficial effects:

[0036] The electron beam curing-based composite film of this invention features a transition layer formed by curing a transition coating between the substrate and the EB coating. This transition layer effectively enhances the adhesion between the EB coating and the substrate, reduces the offset of decorative patterns before and after printing, and effectively improves the fineness of the decorative patterns. Furthermore, the transition layer itself also possesses good resistance to yellowing, improving the overall yellowing resistance of the composite film. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the composite membrane structure in one embodiment of the present invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0039] refer to Figure 1This invention provides a composite film based on electron beam curing, comprising a substrate 3, a transition layer 2 and an EB coating 1 sequentially disposed on the substrate 3. The substrate 3 is one or more of PP, PET, PE, PETG, PVC, PS, PMMA, and bleached kraft paper, but is not limited thereto.

[0040] The transition layer 2 is obtained by curing a transition coating, which comprises the following components in parts by weight:

[0041]

[0042] The acrylic resin is a thermoplastic acrylic resin. The coating system formed by combining it with cellulose acetate butyrate resin exhibits good mechanical properties, chemical resistance, water resistance, and yellowing resistance. The molecular weight of the acrylic resin is 90,000-120,000, with exemplary values ​​of 95,000, 100,000, 105,000, 110,000, or 115,000, but not limited to these. Preferably, it is 100,000-120,000. The glass transition temperature of the acrylic resin is 85-100℃. When its glass transition temperature is <85℃, decorative textures cannot effectively penetrate to the transition layer, resulting in poor decorative effect and low fineness. When its glass transition temperature is >100℃, the flexibility of the transition layer is poor, making it unsuitable for curling. Preferably, the glass transition temperature of the acrylic resin is 90-100℃. Specifically, the amount of acrylic resin used is 40-60 parts, for example 42 parts, 44 parts, 46 parts, 50 parts, 52 parts, 54 parts, 56 parts or 58 parts, but not limited to these.

[0043] The combined use of cellulose acetate butyrate resin and acrylic resin can improve various properties of the coating film (such as water resistance, flexibility, and resistance to yellowing). The amount of cellulose acetate butyrate resin used is 15-25 parts, with exemplary examples being 17, 19, 21, 23, or 24 parts, but not limited thereto. Preferably, the amount of cellulose acetate butyrate resin used is 17-23 parts.

[0044] Isopropanol and n-propyl acetate are used as solvents. Their combined use ensures thorough and uniform mixing of cellulose acetate butyrate resin, acrylic resin, and other components. Specifically, the amount of isopropanol used is 3-10 parts, with examples of 4, 5, 6, 7, or 9 parts, but not limited to these. The amount of n-propyl acetate used is 10-20 parts, with examples of 11, 12, 13, 15, 17, or 18 parts, but not limited to these.

[0045] The inorganic pigment can be one or more of cinnabar, titanium dioxide, carbon black, iron oxide, ferrous oxide, cobalt oxide, zinc oxide, and chromium oxide, but is not limited to these. Preferably, iron oxide is used, as it can effectively improve the aging resistance of the coating film. Specifically, the amount of inorganic pigment used is 1-5 parts, exemplarily 1.5 parts, 2 parts, 3 parts, or 4.5 parts, but is not limited to these. Preferably, it is 4-5 parts.

[0046] It should be noted that although cellulose acetate butyrate resin has good resistance to yellowing, its high hardness and cost make it unsuitable for large-scale use. Therefore, this application introduces a relatively large amount of inorganic pigments into the formulation, appropriately reducing the amount of cellulose acetate butyrate resin while ensuring good yellowing resistance in the transition layer. However, introducing a large amount of inorganic pigments can easily lead to uneven dispersion, resulting in poor leveling of the transition layer coating and a decrease in the fineness of the surface texture of the composite film. Therefore, in one embodiment of this invention, 1-2 parts of hydroxyacrylate are also introduced into the formulation. Through the synergistic effect of hydroxyacrylate, acrylic resin, and cellulose acetate butyrate resin, the wettability of acrylic resin and cellulose acetate butyrate resin to pigments can be effectively improved, as well as solvent release, yellowing resistance, leveling, and the precision of the surface texture of the composite film.

[0047] The first additive may be a commonly used inorganic filler (such as silica, heavy calcium carbonate, light calcium carbonate, barium sulfate, etc.), leveling agent, coupling agent, dispersant, or wetting agent, but is not limited thereto. Preferably, in one embodiment of the present invention, the first additive comprises, by weight parts:

[0048] Dispersant 1.0-1.5 parts;

[0049] 0.5-1.5 parts wetting agent;

[0050] The dispersant used is BYK-9076 and / or Dow Corning 6030, and the wetting agent used is BYK-220S and / or BYK-P104s. The introduction of dispersants and wetting agents further improves the leveling and wetting properties of the transition coating, enhances the yellowing resistance of the transition layer, and improves the adhesion and surface texture fineness of the EB coating.

[0051] Specifically, the surface tension of the transition coating is ≥40 mN / m. By controlling the surface tension, suitable adhesion properties can be provided for the EB coating. Preferably, the surface tension of the transition coating is 60-100 mN / m.

[0052] Specifically, the preparation method of the transition coating is as follows:

[0053] (1) Mix the inorganic pigment, the first auxiliary agent, isopropanol and n-propyl acetate evenly and grind until the particle size is ≤5μm;

[0054] (2) Add acrylic resin and cellulose acetate butyrate resin in sequence, and stir evenly to obtain a transition coating.

[0055] EB coating is a commonly used coating in the art for covering organic surfaces (such as PP, PE, PI, etc.), but is not limited thereto. Preferably, in one embodiment of the present invention, the EB coating comprises the following components in parts by weight:

[0056]

[0057] The EB coating obtained from the above-mentioned components has high surface hardness and good resistance to yellowing.

[0058] Specifically, the modified polyurethane acrylic resin is a polyurethane acrylic resin modified with linseed oil alkyd, but it is not limited to this.

[0059] Based on the modified polyurethane acrylic resin mentioned above, the bonding force between the EB coating and the transition layer can be effectively improved, further enhancing the fineness of the surface texture.

[0060] The monomer is selected from one or more of 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, cyclotrimethylolpropane methyl acetal acrylate, isodecyl acrylate, and ethoxylated trimethylolpropane triacrylate, but is not limited thereto. Preferably, the monomer is selected from one or more of 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, and isodecyl acrylate. The amount of monomer used is 10-80 parts, exemplary amounts are 13 parts, 22 parts, 31 parts, 40 parts, 55 parts, 67 parts, or 74 parts, but is not limited thereto.

[0061] The filler is selected from one or more of the following: light calcium carbonate, fumed silica, barium sulfate, calcined kaolin, talc, and titanium dioxide, but is not limited thereto. Preferably, the filler is fumed silica or calcined kaolin. The amount of filler used is 1-5 parts, exemplarily 1.5 parts, 2 parts, 3 parts, or 4.5 parts, but is not limited thereto.

[0062] The second auxiliary agent is selected from one or more of the following: silane coupling agent, titanate coupling agent, surfactant, defoamer, ultraviolet absorber, antistatic particles, and antifingerprint agent, but is not limited thereto. Preferably, in one embodiment of the present invention, the second auxiliary agent comprises, by weight:

[0063] 0-2 parts of ultraviolet absorber;

[0064] 0-2 parts of defoamer;

[0065] Defoamer: BYK025 and / or BYK028; UV absorber: UV-326, UV-531, One or more of UV-1577.

[0066] Specifically, the preparation method of EB coating is as follows: mix all components evenly and degas to obtain EB coating.

[0067] The EB layer 1 prepared with the aforementioned EB coating and the transition layer 2 prepared with the transition coating effectively improve the weather resistance (resistance to yellowing), scratch resistance, and stain resistance of the composite film. Simultaneously, it also effectively enhances the fineness of the decorative patterns. The composite film of this invention is particularly suitable for producing decorative patterns with shallow depth, high fineness, and small size.

[0068] Accordingly, the present invention also discloses a method for preparing the above-mentioned composite film based on electron beam curing, which includes the following steps:

[0069] (1) Provide the substrate;

[0070] Preferably, in one embodiment of the present invention, the substrate is subjected to corona treatment to increase the surface polarity of the substrate and improve the coating adhesion. Specifically, the voltage of the corona treatment is 10000-15000V / m. 2 The processing speed is 10-30mpm.

[0071] (2) Apply a transition coating to the surface of the substrate to form a transition layer;

[0072] The transition coating can be applied to the substrate surface using methods such as spin coating, spray coating, or transfer printing, but is not limited to these methods. Preferably, in one embodiment of the invention, the transition layer is prepared onto the substrate surface using a thermal transfer method. Based on this method, decorative patterns can be formed on the transition layer. Specifically, the thermal transfer process includes: printing the transition coating onto thermal transfer paper, and then transferring it to the substrate using thermal transfer. The coating amount of the transition coating is 1-5 g / m². 2 An example is 1.5g / m 2 2g / m 2 3g / m 2 Or 4.5g / m 2 .

[0073] Preferably, after applying the transition coating, a heat treatment is performed at a temperature of 50-95°C. If the heat treatment temperature is too high, the texture of the subsequent embossing cannot penetrate into the transition layer, resulting in poor texture fineness. If the heat treatment temperature is too low, the uniformity of the subsequent EB coating application is poor. Exemplary heat treatment temperatures are 55°C, 60°C, 68°C, 75°C, 83°C, or 90°C, but are not limited to these. A preferred temperature is 75-85°C. The heat treatment time is 50-100 seconds, preferably 80-100 seconds.

[0074] (3) Apply EB coating to the transition layer;

[0075] The EB coating can be applied to the transition layer using methods such as spin coating or spraying, but is not limited to these methods. Preferably, in one embodiment of the invention, the EB coating is applied to the transition layer using a slot coating method. The width of the slot is 8-20 μm. Specifically, the coating amount of the EB coating is 10-50 g / m². 2 For example, it is 12g / m 2 16g / m 2 25g / m 2 31g / m 2 38g / m 2 42g / m 2 Or 45g / m 2 However, it is not limited to this.

[0076] (4) Electron beam curing is performed simultaneously with embossing to obtain the composite film product;

[0077] Specifically, the substrate obtained in step (3) is loaded into an electron beam curing device and embossed under electron beam curing to obtain a composite film.

[0078] The energy of electron beam curing is 100-500 keV, and the radiation dose is 3-10 mR, but it is not limited to these.

[0079] The present invention will be further described below with reference to specific embodiments:

[0080] Example 1

[0081] This embodiment provides a composite film based on electron beam curing, referencing... Figure 1 It includes a substrate 3, a transition layer 2 and an EB coating 1 sequentially disposed on the substrate 3; the substrate 3 is PET;

[0082] The transition layer is obtained by curing a transition coating, which comprises the following components in parts by weight:

[0083]

[0084]

[0085] The inorganic pigment is iron oxide, the dispersant is BYK-9076, and the wetting agent is BYK-220S. The acrylic resin has a molecular weight of 110,000 and a glass transition temperature of 88℃.

[0086] The preparation method of the transition coating is as follows:

[0087] (i) Mix the inorganic pigment, dispersant, wetting agent, isopropanol and n-propyl acetate evenly and grind until the particle size is ≤5μm;

[0088] (ii) Add acrylic resin and cellulose acetate butyrate resin in sequence, and stir evenly to obtain a transition coating.

[0089] The EB coating is obtained by curing EB paint, which comprises the following components in parts by weight:

[0090]

[0091] The preparation method of EB coating is as follows: mix all components evenly, and remove bubbles under vacuum to obtain the final product.

[0092] The preparation method of the composite membrane is as follows:

[0093] (1) Provide a substrate and subject it to corona treatment. Specifically, the high-frequency AC voltage is 12000V / m. 2 The production speed is 20 mpm.

[0094] (2) Apply a transition coating to the surface of the substrate and heat it to form a transition layer;

[0095] The transition coating is printed onto heat transfer paper, and then transferred to the substrate using heat transfer printing. The coating amount of the transition coating is 3.5 g / m². 2 After heat transfer, heat-treat at 80℃ for 90 seconds.

[0096] (3) Apply EB coating to the transition layer;

[0097] EB coating was applied to the transition layer using a slotted coating method. The width of the slots was 10 μm. The coating amount of EB was 40 g / m². 2 .

[0098] (4) Electron beam curing is performed simultaneously with embossing to obtain the composite film product;

[0099] Specifically, the substrate obtained in step (3) is loaded into an electron beam curing device and embossed under electron beam curing to obtain a composite film. The electron beam curing energy is 300 keV and the radiation dose is 5 mR.

[0100] Example 2

[0101] This embodiment provides a composite film based on electron beam curing, referencing... Figure 1 It includes a substrate 3, a transition layer 2 and an EB coating 1 sequentially disposed on the substrate 3; the substrate 3 is PET;

[0102] The transition layer is obtained by curing a transition coating, which comprises the following components in parts by weight:

[0103]

[0104] The inorganic pigment is iron oxide, the dispersant is BYK-9076, and the wetting agent is BYK-220S. The acrylic resin has a molecular weight of 110,000 and a glass transition temperature of 88℃.

[0105] The preparation method of the transition coating is as follows:

[0106] (i) Mix the inorganic pigment, dispersant, wetting agent, isopropanol and n-propyl acetate evenly and grind until the particle size is ≤5μm;

[0107] (ii) Add acrylic resin and cellulose acetate butyrate resin in sequence, and stir evenly to obtain a transition coating.

[0108] The EB coating is obtained by curing EB paint, which comprises the following components in parts by weight:

[0109]

[0110] The preparation method of EB coating is as follows: mix all components evenly, and remove bubbles under vacuum to obtain the final product.

[0111] The preparation method of the composite membrane is as follows:

[0112] (1) Provide a substrate and subject it to corona treatment. Specifically, the high-frequency AC voltage is 12000V / m. 2 The production speed is 20 mpm.

[0113] (2) Apply a transition coating to the surface of the substrate and heat it to form a transition layer;

[0114] The transition coating is printed onto heat transfer paper, and then transferred to the substrate using heat transfer printing. The coating amount of the transition coating is 3.5 g / m². 2 After heat transfer, heat-treat at 80℃ for 90 seconds.

[0115] (3) Apply EB coating to the transition layer;

[0116] EB coating was applied to the transition layer using a slotted coating method. The width of the slots was 10 μm. The coating amount of EB was 40 g / m². 2 .

[0117] (4) Electron beam curing is performed simultaneously with embossing to obtain the composite film product;

[0118] Specifically, the substrate obtained in step (3) is loaded into an electron beam curing device and embossed under electron beam curing to obtain a composite film. The electron beam curing energy is 300 keV and the radiation dose is 5 mR.

[0119] Example 3

[0120] This embodiment provides a composite film based on electron beam curing, referencing... Figure 1 It includes a substrate 3, a transition layer 2 and an EB coating 1 sequentially disposed on the substrate 3; the substrate 3 is PET;

[0121] The transition layer is obtained by curing a transition coating, which comprises the following components in parts by weight:

[0122]

[0123] The inorganic pigment is iron oxide, the dispersant is BYK-9076, and the wetting agent is BYK-220S. The acrylic resin has a molecular weight of 110,000 and a glass transition temperature of 88℃.

[0124] The preparation method of the transition coating is as follows:

[0125] (i) Mix the inorganic pigment, dispersant, wetting agent, isopropanol and n-propyl acetate evenly and grind until the particle size is ≤5μm;

[0126] (ii) Add acrylic resin and cellulose acetate butyrate resin in sequence, and stir evenly to obtain a transition coating.

[0127] The EB coating is obtained by curing EB paint, which comprises the following components in parts by weight:

[0128]

[0129]

[0130] The preparation method of EB coating is as follows: mix all components evenly, and remove bubbles under vacuum to obtain the final product.

[0131] The preparation method of the composite membrane is as follows:

[0132] (1) Provide a substrate and subject it to corona treatment. Specifically, the high-frequency AC voltage is 12000V / m. 2 The production speed is 20 mpm.

[0133] (2) Apply a transition coating to the surface of the substrate and heat it to form a transition layer;

[0134] The transition coating is printed onto heat transfer paper, and then transferred to the substrate using heat transfer printing. The coating amount of the transition coating is 3.5 g / m². 2After heat transfer, heat-treat at 80℃ for 90 seconds.

[0135] (3) Apply EB coating to the transition layer;

[0136] EB coating was applied to the transition layer using a slotted coating method. The width of the slots was 10 μm. The coating amount of EB was 40 g / m². 2 .

[0137] (4) Electron beam curing is performed simultaneously with embossing to obtain the composite film product;

[0138] Specifically, the substrate obtained in step (3) is loaded into an electron beam curing device and embossed under electron beam curing to obtain a composite film. The electron beam curing energy is 300 keV and the radiation dose is 5 mR.

[0139] Example 4

[0140] This embodiment provides a composite film based on electron beam curing, referencing... Figure 1 It includes a substrate 3, a transition layer 2 and an EB coating 1 sequentially disposed on the substrate 3; the substrate 3 is PET;

[0141] The transition layer is obtained by curing a transition coating, which comprises the following components in parts by weight:

[0142]

[0143] The inorganic pigment is iron oxide, the dispersant is BYK-9076, and the wetting agent is BYK-220S. The acrylic resin has a molecular weight of 115,000 and a glass transition temperature of 92℃.

[0144] The preparation method of the transition coating is as follows:

[0145] (i) Mix the inorganic pigment, dispersant, wetting agent, isopropanol and n-propyl acetate evenly and grind until the particle size is ≤5μm;

[0146] (ii) Add acrylic resin and cellulose acetate butyrate resin in sequence, and stir evenly to obtain a transition coating.

[0147] The EB coating is obtained by curing EB paint, which comprises the following components in parts by weight:

[0148]

[0149] The preparation method of EB coating is as follows: mix all components evenly, and remove bubbles under vacuum to obtain the final product.

[0150] The preparation method of the composite membrane is as follows:

[0151] (1) Provide a substrate and subject it to corona treatment. Specifically, the high-frequency AC voltage is 12000V / m. 2 The production speed is 20 mpm.

[0152] (2) Apply a transition coating to the surface of the substrate and heat it to form a transition layer;

[0153] The transition coating is printed onto heat transfer paper, and then transferred to the substrate using heat transfer printing. The coating amount of the transition coating is 3.5 g / m². 2 After heat transfer, heat-treat at 80℃ for 90 seconds.

[0154] (3) Apply EB coating to the transition layer;

[0155] EB coating was applied to the transition layer using a slotted coating method. The width of the slots was 10 μm. The coating amount of EB was 40 g / m². 2 .

[0156] (4) Electron beam curing is performed simultaneously with embossing to obtain the composite film product;

[0157] Specifically, the substrate obtained in step (3) is loaded into an electron beam curing device and embossed under electron beam curing to obtain a composite film. The electron beam curing energy is 300 keV and the radiation dose is 5 mR.

[0158] The composite membranes obtained in Examples 1-4 were tested using the following specific testing methods:

[0159] The performance of the release film prepared according to the present invention was tested using the following methods:

[0160] 1. Surface hardness:

[0161] Use a pencil sharpener to remove the wooden part at the tip of the pencil, exposing the cylindrical lead core. The exposed lead core length should be controlled between 6-8mm. Sand the lead core flat on 80# sandpaper to form a flat surface and sharp edges. Then, fix the pencil at a 45-degree angle and apply a load of 750g. Press the pencil tip onto the coating and push it at a speed of 0.5mm / s to 1mm / s for at least 7mm. Gradually increase the pencil hardness until you find a pencil that does not scratch the coating. The hardness of this pencil is the hardness of the tested coating.

[0162] 2. Coating adhesion cross-cut adhesion test

[0163] Use a sharp cross-cutting tool to make 10 horizontal and 10 vertical lines on the coating film of the workpiece, 0.5 mm deep, extending above the coating substrate. The spacing between each line is 1 mm, forming 100 lines with an area of ​​1 mm². 2Small grids; Cover one end of the 3M 600 adhesive tape and apply it to the surface of the grid, then press it flat with your finger until there are no air bubbles inside the adhesive tape; Lift one end of the 3M adhesive tape at a 45-degree angle to the tested surface, and then quickly pull up the 3M 600 adhesive tape with force. The pulling speed is 5 m / s and the number of times is 2 times;

[0164] Judgment criterion: No film peeling is allowed, and it is judged as qualified; otherwise, it is unqualified;

[0165] 3. Alcohol wear resistance test

[0166] Dip the test alcohol with a cloth until the alcohol stops dripping, then cover the tested surface with the cotton cloth and press it with your finger. Apply a force of about 500 g and move your finger until you can move the cotton cloth. Move it back and forth parallel on the tested surface. The test time is 15 seconds, about one round trip per second;

[0167] Judgment criterion: After being wiped with alcohol, if the coating layer has no exposed substrate, it is judged as qualified; otherwise, it is unqualified

[0168] 4. Glossiness test

[0169] Measure the glossiness of the coating with a 60-degree glossiness meter.

[0170] 5. Yellowing resistance test

[0171] Use a UVA (340 nm) lamp as the light source, place the test panel in a fluorescent ultraviolet aging machine where the test conditions can meet the blackboard temperature of 60 ± 3 °C, irradiance of 0.76 W / (m 2 ·nm) @ 340 nm, dry phase (no condensation). After continuous light exposure for 168 h throughout the process, measure the color change (ΔE) corresponding to the covered part with a color difference meter.

[0172] 6. Fineness of decorative pattern: Visual inspection.

[0173] The test results are shown in the following table:

[0174] Surface hardness Adhesion Alcohol abrasion resistance gloss ΔE Decorative patterns Example 1 3H qualified qualified 4.8 3.2 High level of precision Example 2 3H qualified qualified 4.3 3.6 Low level of precision Example 3 3H qualified qualified 5.1 2.2 High level of precision Example 4 3H qualified qualified 5.3 2.0 High level of precision

[0175] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. A composite film based on electron beam curing, characterized in that, It includes a substrate, a transition layer and an EB coating disposed sequentially on the substrate; The transition layer is obtained by curing a transition coating, which comprises the following components in parts by weight: 40-60 parts of acrylic resin; 15-25 parts of cellulose acetate butyrate resin; 3-10 parts isopropanol; 10-20 parts of n-propyl acetate; 1-5 parts of inorganic pigment; First adjuvant 1-6 parts; 1-2 parts of hydroxyacrylate; The acrylic resin has a glass transition temperature of 90-100℃ and a molecular weight of 100,000-120,000. The surface tension of the transition coating is ≥40mN / m; The EB coating is obtained by curing EB paint.

2. The composite film based on electron beam curing as described in claim 1, characterized in that, The first adjuvant comprises, by weight: Dispersant 1.0-1.5 parts; 0.5-1.5 parts wetting agent; The dispersant selected is BYK-9076 and / or Dow Corning 6030; The wetting agent is selected from BYK-220S and / or BYK-P104s.

3. The composite film based on electron beam curing as described in claim 1, characterized in that, The EB coating comprises the following components in parts by weight: 40-80 parts of modified polyurethane acrylic resin; 10-80 parts of monomer; 1-5 parts of filler; Second adjuvant 1-5 parts.

4. The composite film based on electron beam curing as described in claim 3, characterized in that, The monomer is selected from one or more of the following: 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, cyclotrimethylolpropane methyl acetal acrylate, isodecyl acrylate, and ethoxylated trimethylolpropane triacrylate. The filler is selected from one or more of the following: light calcium carbonate, fumed silica, barium sulfate, calcined kaolin, talc, and titanium dioxide. The second additive is selected from one or more of the following: silane coupling agent, titanate coupling agent, surfactant, defoamer, ultraviolet absorber, antistatic particles, and antifingerprint agent.

5. The composite film based on electron beam curing according to claim 3, characterized in that, The second adjuvant comprises, by weight: 0-2 parts of ultraviolet absorber; 0-2 parts of defoamer; The defoamer is selected from BYK-025 and / or BYK-028; The ultraviolet absorber is selected from one or more of RIASORB® UV-326, RIASORB® UV-531, and RIASORB® UV-1577.

6. The composite film based on electron beam curing as claimed in claim 1, characterized in that, The substrate is selected from one or more of PP, PET, PE, PETG, PVC, PS, PMMA, and bleached kraft paper.

7. A method for preparing an electron beam-cured composite film, used to prepare the electron beam-cured composite film as described in any one of claims 1-6, characterized in that, include: Provide substrate A transition coating is applied to the surface of the substrate to form a transition layer; EB coating is applied to the transition layer; Electron beam curing is performed simultaneously with embossing to obtain the finished composite film.

8. The method for preparing a composite film based on electron beam curing as described in claim 7, characterized in that, The coating amount of the transition coating is 1-5 g / m². 2 The coating amount of the EB coating is 10-50 g / m². 2 ; The energy of electron beam curing is 100-500 keV, and the radiation dose is 3-10 mR.

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