Laser film transfer coating and preparation method thereof

Abstract

The present application discloses a coating for laser film transfer and a preparation method thereof, relating to the field of coatings. The coating is made from the following raw materials in parts by weight: 25-35 parts of waterborne polyurethane, 35-45 parts of modified acrylate, 3-6 parts of other additives, and 20-40 parts of water; the modified acrylate is polymerized sequentially by a first monomer, a second monomer, and a third monomer; the first monomer comprises methyl methacrylate, lauryl methacrylate, and methacrylic acid; the second monomer comprises methyl methacrylate, lauryl methacrylate, isobornyl methacrylate, and diacetone acrylamide; and the third monomer comprises methyl methacrylate, lauryl methacrylate, and N-tert-butyl acrylamide. The present application has the effect of improving the adhesion between the coating and the base film and ink, respectively.

Description

Technical Field

[0001] The present application relates to the field of coatings, and in particular to a coating for laser film transfer and a preparation method thereof. Background Art

[0002] Laser film is a film layer commonly used in modern decoration and packaging industries with bright visual effects and anti-counterfeiting functions. It is produced by coating the substrate with a coating and then performing high-temperature molding to produce a dynamic three-dimensional visual effect.

[0003] At present, coatings for laser film transfer often use solvent-based polyacrylic resins, cellulose resins, nitrocellulose resins, etc., which are often accompanied by the use of a large amount of organic solvents. PET film and BOPP film are often used as substrates. PET film is often used in high-end scenes due to its high barrier properties, while BOPP film is favored for its high cost performance and good performance.

[0004] However, the use of solvent-based coatings is not only harmful to the health of production workers but also pollutes the environment, while water-based coatings for laser film transfer have poor adhesion to substrates and inks. Summary of the Invention

[0005] In view of the deficiencies of the above-mentioned related technologies, the present application provides a coating for laser film transfer and a preparation method thereof.

[0006] On the one hand, the present application provides a coating for laser film transfer using the following technical solution:

[0007] A coating for laser film transfer is made from the following raw materials in parts by weight: 25-35 parts of waterborne polyurethane, 35-45 parts of modified acrylate, 3-6 parts of other additives, and 20-40 parts of water; the modified acrylate is prepared by sequentially polymerizing a first monomer, a second monomer, and a third monomer; the first monomer comprises methyl methacrylate, lauryl methacrylate, and methacrylic acid; the second monomer comprises methyl methacrylate, lauryl methacrylate, isobornyl methacrylate, and diacetone acrylamide; and the third monomer comprises methyl methacrylate, lauryl methacrylate, and N-tert-butyl acrylamide.

[0008] Preferably, the weight ratio of methyl methacrylate, lauryl methacrylate and methacrylic acid in the first monomer is 20-30:2-5:1.

[0009] Preferably, the weight ratio of methyl methacrylate, lauryl methacrylate, isobornyl methacrylate and diacetone acrylamide in the second monomer is 8-12:35-45:5-7:1.

[0010] Preferably, the weight ratio of methyl methacrylate, lauryl methacrylate and N-tert-butyl acrylamide in the third monomer is 15-25:8-12:1.

[0011] Preferably, the modified acrylate is prepared by the following steps: taking a first monomer to prepare a first monomer mixture, taking deionized water, an emulsifier, a pH buffer and 5%-15% of the first monomer mixture and adding an initiator dropwise at 78-84° C. under a nitrogen atmosphere with stirring to obtain a seed emulsion; simultaneously adding the initiator and the remaining first monomer mixture dropwise to the seed emulsion to react to obtain a first emulsion; taking a second monomer to prepare a second monomer mixture, simultaneously adding the initiator and the second monomer mixture dropwise to the first emulsion to react to obtain a second emulsion; taking a third monomer to prepare a third monomer mixture, simultaneously adding the initiator and the third monomer mixture dropwise to the second emulsion to react to obtain a third emulsion; after the third emulsion is cooled to room temperature, the pH is adjusted, adipic acid dihydrazide is added, and the material is stirred and filtered to obtain the modified acrylate.

[0012] Preferably, the weight ratio of the first monomer, the second monomer and the third monomer is 0.9-1:0.9-1:1.

[0013] Preferably, the waterborne polyurethane is prepared by the following steps: under a nitrogen atmosphere, polypropylene glycol, toluene diisocyanate and dibutyltin dilaurate are mixed, reacted at a temperature of 58-62° C. for 1-3 hours, then a solvent and hydroxyethyl acrylate are added, the reaction is continued for 2-4 hours, and finally triethylamine is added and stirred for 30 minutes, and the solvent is removed by reduced pressure distillation to obtain the waterborne polyurethane.

[0014] Preferably, the weight ratio of the polypropylene glycol, toluene diisocyanate and hydroxyethyl acrylate is 4-6:1-2:1.

[0015] Preferably, the other additives include one or more of a leveling agent, a cosolvent, a film-forming aid and a defoaming agent.

[0016] On the other hand, the present application provides a method for preparing a coating for laser film transfer using the following technical solution:

[0017] A method for preparing a coating for laser film transfer comprises the following steps: mixing and stirring waterborne polyurethane, modified acrylic emulsion, water and other additives uniformly to obtain the coating for laser film transfer.

[0018] Preferably, the process comprises the following steps: mixing a leveling agent, a film-forming aid, a cosolvent (ethanol) and deionized water, adding waterborne polyurethane and modified acrylate under continuous stirring, and finally adding a defoaming agent, stirring evenly to obtain a coating for laser film transfer.

[0019] In summary, this application includes at least one of the following beneficial technical effects:

[0020] 1. The particles in the modified acrylate are composed of three layers with different glass transition temperatures. The innermost part with the highest methyl methacrylate content has the highest glass transition temperature, while the middle layer has the lowest glass transition temperature. The soft structure of the middle layer is conducive to absorbing the internal stress generated during the curing process. During high-temperature molding, the outermost layer containing N-tert-butyl acrylamide undergoes cross-linking first. The polar and non-polar groups in it improve the adhesion to different types of base films. Then, isobornyl methacrylate with low surface tension and low polymerization shrinkage is released to improve the wettability of the modified acrylate on the base film surface and improve the adhesion of N-tert-butyl acrylamide to the base film. While acrylamide covers the surface of the base film, it reduces the degree of micro-deformation of the base film caused by polymerization, and finally releases the innermost layer of molecular chains mainly obtained by copolymerization of lauryl methacrylate and methyl methacrylate. After copolymerization with the molecular chain containing diacetone acrylamide monomer, cross-linking occurs between the molecular chains through the hydrazide group of adipic acid dihydrazide and the ketone carbonyl group of diacetone acrylamide. Under the combined effect, the overall required high-temperature molding temperature is reduced, the degree of thermal deformation of BOPP film when used as a base film is reduced, the film-forming effect and adhesion of the laser film transfer coating on the base film are improved, and the applicable base film range of the laser film transfer coating is broadened.

[0021] 2. On the one hand, the hydroxyethyl acrylate in the waterborne polyurethane is cross-linked with the modified acrylate and the interaction force with other components is enhanced through hydrogen bonds, thereby improving the integrity of the film-forming coating for laser film transfer, thereby improving the adhesion effect of the laser film transfer coating on the PET film and the BOPP film, and avoiding as much as possible the film-forming defects of the laser film transfer coating during the coating process; on the other hand, the polar groups and non-polar groups in the polyurethane and modified acrylate are conducive to improving the binding effect with the ink components in all directions. Under the combined effect, the adhesion between the laser film transfer coating and the base film and the ink is improved.

[0022] 3. The strong polar groups in polyurethane and modified acrylate are conducive to forming hydrogen bonds with the aluminum oxide layer, and the carbonyl oxygen atoms and oxygen atoms in the ester bond are conducive to forming coordination bonds with aluminum ions, which improves the bonding effect between the laser film transfer coating and the aluminum film and reduces the probability of the coating and UV ink falling off from the aluminum film. DETAILED DESCRIPTION

[0023] The present application is described in further detail below in conjunction with Examples. The following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. In the following examples, if specific conditions are not specified, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. The methods used are conventional methods well known in the art unless otherwise specified, and the consumables and reagents used are commercially available unless otherwise specified. Unless otherwise indicated, the professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to the described content may also be applied to the present invention.

[0024] Example 1

[0025] Example 1 provides a coating for laser film transfer, and the preparation method is as follows:

[0026] Preparation of waterborne polyurethane: Under nitrogen protection, take 20g polypropylene glycol-1000, 6g toluene diisocyanate and 0.1g dibutyltin dilaurate, mix them, react at 60°C for 2h, then add acetone solvent and 4g hydroxyethyl acrylate, continue to react for 3h, and finally add 0.3g triethylamine and stir for 30min. During the stirring process, deionized water is added to control the solid content to 30%, and the acetone solvent is removed by reduced pressure distillation to obtain waterborne polyurethane.

[0027] Preparation of modified acrylate: 0.2 g of ammonium persulfate was prepared into an initiator solution with a concentration of 0.05 g / mL, and a first monomer mixture was prepared by taking 25 g of methyl methacrylate, 3 g of lauryl methacrylate, 1 g of methacrylic acid, 0.29 g of a chain transfer agent (dodecyl mercaptan), 0.5 g of an emulsifier (alkylphenol polyoxyethylene ether, OP-10), and 10 g of deionized water. 50 g of deionized water, 0.15 g of an emulsifier (alkylphenol polyoxyethylene ether, OP-10), 0.1 g of a pH buffer (sodium bicarbonate), and 10% of the first monomer mixture were added to a reaction vessel, mechanically stirred at a stirring rate of 400 r / min, and heated to 80°C under a nitrogen atmosphere. 15% of the total amount of the initiator solution was added dropwise over a reaction time of 30 min to obtain a seed emulsion. 25% of the total amount of the initiator solution and the remaining first monomer mixture were simultaneously added dropwise to the seed emulsion over a reaction time of 1 h. After the addition was complete, the mixture was kept warm for 30 min to obtain a first emulsion.

[0028] A second monomer mixture was prepared by taking 3 g of isobornyl methacrylate, 20 g of lauryl methacrylate, 5 g of methyl methacrylate, 0.5 g of diacetone acrylamide, 0.28 g of a chain transfer agent (dodecyl mercaptan), 0.5 g of an emulsifier (sodium allyloxyhydroxypropyl sulfonate, COPS-1), and 25 g of deionized water; 40% of the total amount of the initiator solution and the second monomer mixture were simultaneously added dropwise to the first emulsion over a reaction time of 2 h. After the addition was complete, the mixture was kept warm for 1 h to obtain a second emulsion;

[0029] A third monomer mixture was prepared by taking 1 g of N-tert-butylacrylamide, 20 g of methyl methacrylate, 10 g of lauryl methacrylate, 0.3 g of a chain transfer agent (dodecyl mercaptan), 0.3 g of an emulsifier (alkylphenol polyoxyethylene ether, OP-10), and 10 g of deionized water; the third monomer mixture and the remaining initiator solution were simultaneously added dropwise to the second emulsion over a reaction time of 1 h, and the mixture was kept warm for 2 h after the addition was complete to obtain a third emulsion;

[0030] After the third emulsion cooled to room temperature, the pH was adjusted to 8 with aqueous ammonia, 0.35 g of adipic acid dihydrazide was added, and the mixture was stirred for 30 minutes. The material was filtered to obtain modified acrylate.

[0031] Preparation of coating: Take 0.15g of leveling agent (acrylate leveling agent, BYK-350), 0.2g of film-forming aid (dodecyl alcohol ester), 5g of co-solvent (ethanol) and 30g of deionized water, stir and mix, then add 30g of water-based polyurethane and 40g of modified acrylate under continuous stirring, and finally add 0.08g of defoaming agent (silicone defoaming agent, BYK-025), stir evenly to obtain the coating for laser film transfer.

[0032] Example 2

[0033] Example 2 provides a coating for laser film transfer. The difference between Example 2 and Example 1 is that 25 g of water-based polyurethane and 45 g of modified acrylate are added in the coating preparation step in Example 2.

[0034] Example 3

[0035] Example 3 provides a coating for laser film transfer. The difference between Example 3 and Example 1 is that 35 g of waterborne polyurethane and 35 g of modified acrylate are added in the coating preparation step in Example 3.

[0036] Example 4

[0037] Example 4 provides a coating for laser film transfer. The difference between Example 4 and Example 1 is that in the modified acrylate preparation step in Example 4, 2 g of isobornyl methacrylate is used in the second monomer mixture.

[0038] Example 5

[0039] Example 5 provides a coating for laser film transfer. The difference between Example 5 and Example 1 is that in the modified acrylate preparation step in Example 5, 4 g of isobornyl methacrylate is used in the second monomer mixture.

[0040] Example 6

[0041] Example 6 provides a coating for laser film transfer. The difference between Example 6 and Example 1 is that in the modified acrylate preparation step in Example 6, 0.5 g of N-tert-butyl acrylamide is used in the third monomer mixture.

[0042] Example 7

[0043] Example 7 provides a coating for laser film transfer. The difference between Example 7 and Example 1 is that in the modified acrylate preparation step in Example 7, 1.5 g of N-tert-butyl acrylamide is used in the third monomer mixture.

[0044] Comparative Example 1

[0045] Comparative Example 1 provides a coating for laser film transfer. The difference between Comparative Example 1 and Example 1 is that: the preparation steps of the modified acrylate in Comparative Example 1 are as follows: 0.2g of ammonium persulfate is prepared into an initiator solution with a concentration of 0.05g / mL, 50g of methyl methacrylate, 0.5g of diacetone acrylamide, 3g of isobornyl methacrylate, 1g of N-tert-butyl acrylamide, 33g of lauryl methacrylate, 1g of methacrylic acid, 0.87g of chain transfer agent (dodecyl mercaptan), 0.8g of alkylphenol polyoxyethylene ether, 0.5g of sodium allyloxyhydroxypropyl sulfonate and 45g of deionized water are prepared into a monomer mixture; 50g of deionized water, 0.15g of alkylphenol polyoxyethylene ether, 0.1g of pH buffer (sodium bicarbonate) and 3% of the monomer mixture are added to a reaction container and heated at 400r / m The mixture was mechanically stirred at a stirring rate of in, heated to 80° C. under a nitrogen atmosphere, and 15% of the total amount of the initiator solution was added dropwise within a reaction time of 30 minutes to obtain a seed emulsion; 25% of the total amount of the initiator solution and 30% of the monomer mixture were simultaneously added dropwise to the seed emulsion within a reaction time of 1 hour, and the mixture was kept warm for 30 minutes after the addition was completed to obtain a first emulsion; 40% of the total amount of the initiator solution and 33% of the monomer mixture were simultaneously added dropwise to the first emulsion within a reaction time of 2 hours, and the mixture was kept warm for 1 hour after the addition was completed to obtain a second emulsion; the remaining monomer mixture and the remaining initiator solution were simultaneously added dropwise to the second emulsion within a reaction time of 1 hour, and the mixture was kept warm for 2 hours after the addition was completed to obtain a third emulsion; the pH was adjusted to 8 with aqueous ammonia, 0.35 g of adipic acid dihydrazide was added, stirred for 30 minutes, and the material was filtered to obtain a modified acrylate.

[0046] Comparative Example 2

[0047] Comparative Example 2 provides a coating for laser film transfer. The difference between Comparative Example 2 and Example 1 is that: the preparation steps of the modified acrylate in Comparative Example 2 are as follows: 0.2g of ammonium persulfate is prepared into an initiator solution with a concentration of 0.05g / mL, 25g of methyl methacrylate, 3g of lauryl methacrylate, 1g of methacrylic acid, 0.29g of a chain transfer agent (dodecyl mercaptan), 0.5g of alkylphenol polyoxyethylene ether and 10g of deionized water are prepared into a first monomer mixture; 50g of deionized water, 0.15g of alkylphenol polyoxyethylene ether, 0.1g of sodium bicarbonate and 10% of the first monomer mixture are added to a reaction container, mechanically stirred at a stirring rate of 400r / min, heated to 80°C under a nitrogen atmosphere, and 15% of the total amount of the initiator solution is added dropwise within a reaction time of 30min to obtain a seed emulsion; 25% of the total amount of the initiator solution and the remaining first monomer mixture are simultaneously added dropwise to the seed emulsion within a reaction time of 1h, and kept warm for 30min after the addition is completed to obtain a first emulsion;

[0048] A second monomer mixture was prepared by taking 3 g of isobornyl methacrylate, 1 g of N-tert-butyl acrylamide, 30 g of lauryl methacrylate, 25 g of methyl methacrylate, 0.5 g of diacetone acrylamide, 0.3 g of alkylphenol polyoxyethylene ether, 0.58 g of dodecyl mercaptan, 0.5 g of sodium allyloxyhydroxypropyl sulfonate and 35 g of deionized water; 40% of the total amount of the initiator solution and 50% of the second monomer mixture were simultaneously added dropwise to the first emulsion within a reaction time of 2 h, and the mixture was kept warm for 1 h after the addition was completed to obtain a second emulsion; the remaining second monomer mixture and the remaining initiator solution were simultaneously added dropwise to the second emulsion within a reaction time of 1 h, and the mixture was kept warm for 2 h after the addition was completed to obtain a third emulsion; after the third emulsion cooled to room temperature, the pH was adjusted to 8 with aqueous ammonia, 0.35 g of adipic acid dihydrazide was added, and the mixture was stirred for 30 min. The material was filtered to obtain a modified acrylate.

[0049] Comparative Example 3

[0050] Comparative Example 3 provides a coating for laser film transfer. The difference between Comparative Example 3 and Example 1 is that the preparation steps of the water-based polyurethane in Comparative Example 3 are as follows: under nitrogen protection, 20g of polypropylene glycol-1000, 6g of toluene diisocyanate and 0.1g of dibutyltin dilaurate are mixed, and the mixture is reacted at 60°C for 2h, and then acetone solvent is added and the reaction is continued for 3h. Finally, 0.3g of triethylamine is added and stirred for 30min. Deionized water is added during the stirring process to control the solid content to 30%, and the acetone solvent is removed by reduced pressure distillation to obtain water-based polyurethane.

[0051] Test and Inspection

[0052] (1) The coatings for laser film transfer of Examples 1-7 and Comparative Examples 1-3 were coated onto PET films to a thickness of 30 μm and subjected to high-temperature molding at 150°C to produce samples. The coatings for laser film transfer of Examples 1-7 and Comparative Examples 1-3 were coated onto BOPP films to a thickness of 30 μm and subjected to high-temperature molding at 80°C to produce samples. The adhesion of the resulting coatings to PET and BOPP films was measured at a temperature of 23±2°C and a relative humidity of 50%±5% in accordance with GB / T9286-1998, as shown in Table 1.

[0053] Table 1:

[0054]

[0055] (2) The coatings for laser film transfer of Examples 1-7 and Comparative Examples 1-3 were coated on a PET film, and then the PET film was peeled off by laminating it on a cardboard with glue. UV ink was printed on the release layer using a small offset printing machine and fully cured. A hundred grids were drawn, and the proportion of ink removed was measured using a 3M tape tester to obtain the adhesion performance of the offset printing ink after transfer. The results are shown in Table 2.

[0056]

[0057] The following is a detailed description of this application in conjunction with the experimental data provided in Table 1-2.

[0058] As can be seen from Table 1, the adhesion of the laser film transfer coatings of Examples 1-7 on PET film and BOPP film is better than that of the laser film transfer coatings of Comparative Examples 1-3. Taking Comparative Examples 1-3 as a control, the adhesion of the laser film transfer coating of Example 1 on PET film and BOPP film is greatly increased. The analysis is because, on the one hand, the particles in the modified acrylate of the laser film transfer coating of Example 1 are composed of a three-layer structure with different glass transition temperatures, wherein the innermost part with the highest methyl methacrylate content has the highest glass transition temperature, and the middle layer has the lowest glass transition temperature. The soft structure part of the middle layer is conducive to absorbing the internal stress generated during the curing process. During high-temperature molding, the outermost layer structure containing N-tert-butyl acrylamide undergoes cross-linking first, and the polar and non-polar groups therein improve the adhesion effect to different types of base films, and then releases isobornyl methacrylate with low surface tension and low polymerization shrinkage, which improves the wettability of the modified acrylate on the base film surface, increases the coverage of N-tert-butyl acrylamide on the base film surface, and reduces the base film from being affected by polymerization. The degree of micro-deformation caused by the effect is reduced, and finally the innermost layer is released, which is mainly composed of the molecular chain obtained by copolymerization of lauryl methacrylate and methyl methacrylate. After copolymerization with the molecular chain containing diacetone acrylamide monomer, cross-linking occurs between the molecular chains through the hydrazide group of adipic acid dihydrazide and the ketone carbonyl group of diacetone acrylamide. Under the combined effect, the temperature required for the overall high-temperature molding is reduced, the degree of thermal deformation of BOPP film when used as the base film is reduced, and the film-forming effect and adhesion of the laser film transfer coating on the base film are improved. On the other hand, the hydroxyethyl acrylate in the water-based polyurethane is cross-linked with the modified acrylate and the force with other parts is increased through hydrogen bonds, thereby improving the integrity of the film-forming of the laser film transfer coating, thereby improving the adhesion effect of the laser film transfer coating on PET film and BOPP film.

[0059] It can be seen from Table 2 that the offset ink adhesion performance of the laser film transfer coatings of Examples 1-7 after transfer is much better than the offset ink adhesion performance of the laser film transfer coatings of Comparative Examples 1-3 after transfer. On the one hand, this is because the laser film transfer coatings of Examples 1-7 have good film-forming effect and high coating integrity, which is beneficial to improving the integrity after combining with UV ink, and the polar groups and non-polar groups therein improve the binding effect with the components in UV ink. On the other hand, the strong polar groups in polyurethane and modified acrylate are beneficial to forming hydrogen bonds with the aluminum oxide layer, and the carbonyl oxygen atoms and oxygen atoms in the ester bonds are beneficial to forming coordination bonds with aluminum ions, which improves the binding effect between the laser film transfer coating and the aluminum film and reduces the probability of the coating and UV ink falling off from the aluminum film together.

[0060] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A coating for laser film transfer, characterized in that: The invention is prepared from the following raw materials in parts by weight: 25-35 parts of waterborne polyurethane, 35-45 parts of modified acrylate, 3-6 parts of other additives, and 20-40 parts of water; the modified acrylate is prepared by sequentially polymerizing a first monomer, a second monomer, and a third monomer; the first monomer comprises methyl methacrylate, lauryl methacrylate, and methacrylic acid; the second monomer comprises methyl methacrylate, lauryl methacrylate, isobornyl methacrylate, and diacetone acrylamide; the third monomer comprises methyl methacrylate, lauryl methacrylate, and N-tert-butyl acrylamide; the weight ratio of methyl methacrylate, lauryl methacrylate, and methacrylic acid in the first monomer is 20-30:2-5:1; the weight ratio of methyl methacrylate, lauryl methacrylate, and methacrylic acid in the second monomer is 20-30:2-5:1; the weight ratio of methyl methacrylate, lauryl methacrylate, and methacrylic acid in the second monomer is 20-30:2-5:1; the weight ratio of methyl methacrylate, lauryl methacrylate, and methacrylic acid in the second monomer is 20-30:2-5:1; the weight ratio of methyl methacrylate, lauryl methacrylate, and methacrylic acid in the first monomer is 20-30:2-5:1; the weight ratio of methyl methacrylate, lauryl methacrylate, and methacrylic acid in the second ... The weight ratio of lauryl methacrylate, isobornyl methacrylate and diacetone acrylamide is 8-12:35-45:5-7:1; the weight ratio of methyl methacrylate, lauryl methacrylate and N-tert-butyl acrylamide in the third monomer is 15-25:8-12:1; the weight ratio of the first monomer, the second monomer and the third monomer is 0.9-1:0.9-1:1; and the waterborne polyurethane is prepared by the following steps: under a nitrogen atmosphere, polypropylene glycol, toluene diisocyanate and dibutyltin dilaurate are mixed, reacted at a temperature of 58-62° C. for 1-3 hours, then added with a solvent and hydroxyethyl acrylate, continued to react for 2-4 hours, finally added with triethylamine and stirred for 30 minutes, and removed the solvent by reduced pressure distillation to obtain the waterborne polyurethane.

2. The coating for laser film transfer according to claim 1, characterized in that: The modified acrylate is The preparation method comprises the following steps: taking a first monomer to prepare a first monomer mixture, taking deionized water, an emulsifier, a pH buffer and 5%-15% of the first monomer mixture and dropping an initiator at 78-84° C. under a nitrogen atmosphere with stirring to obtain a seed emulsion; synchronously dropping the initiator and the remaining first monomer mixture into the seed emulsion to react to obtain a first emulsion; taking a second monomer to prepare a second monomer mixture, synchronously dropping the initiator and the second monomer mixture into the first emulsion to react to obtain a second emulsion; taking a third monomer to prepare a third monomer mixture, synchronously dropping the initiator and the third monomer mixture into the second emulsion to react to obtain a third emulsion; and after the third emulsion cools to room temperature, adjusting the pH, adding adipic acid dihydrazide, stirring, filtering and discharging to obtain the modified acrylate.

3. The coating for laser film transfer according to claim 1, characterized in that: The weight ratio of the polypropylene glycol, toluene diisocyanate and hydroxyethyl acrylate is 4-6:1-2:

1.

4. The coating for laser film transfer according to claim 1, characterized in that: The other additives include one or more of a leveling agent, a cosolvent, a film-forming aid and a defoaming agent.

5. A method for preparing the coating for laser film transfer according to any one of claims 1 to 4, characterized in that: The following steps are involved: The waterborne polyurethane, modified acrylate, water and other additives are mixed and stirred evenly to obtain the coating for laser film transfer.

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