Acrylate modified polyurethane resin emulsion for water-based ink with good adhesion performance to plastic substrate and preparation method of acrylate modified polyurethane resin emulsion

Abstract

The invention relates to the technical field of water-based polyurethane resin emulsion, and provides acrylate modified polyurethane resin emulsion for water-based ink with good adhesion to a plastic base material. The polyurethane resin emulsion is prepared from the following main components through solution polymerization, emulsification and solvent removal: an acrylate oligomer polyol acetone solution, polyester polyol, polyether polyol, diisocyanate, a carboxyl type hydrophilic chain extender, an esterification reaction catalyst, solvent acetone, a low molecular chain extender, a neutralization salt-forming agent and deionized water. The water-based gravure plastic ink prepared from the acrylate modified polyurethane resin emulsion provided by the invention is good in redissolvability and excellent in anti-adhesion performance, and has good adhesion to plastic (PE, BOPP, PVC, PET and the like) film substrates, and the adhesive force is tested by a transparent adhesive tape and reaches zero level. Meanwhile, the water-based plastic ink has good printability and can be applied to the fields of packaging, printing and decoration of various plastic films.

Description

Technical Field

[0001] The present invention relates to the technical field of waterborne polyurethane resin emulsion, and in particular to an acrylate-modified polyurethane resin emulsion for waterborne ink having good adhesion to plastic substrates and a preparation method thereof. Background Art

[0002] Plastic inks are suitable for printing on plastic substrates or films such as PE, BOPP, PVC, PET, and PP. They are generally composed of a binder, colorant, additive, and dispersion medium. Because plastic substrates or films are non-absorbent and have relatively low surface tension, the surface tension of plastic films depends on the surface free energy of the film, which in turn depends on the molecular structure of the film material itself. Most plastic films have low surface free energy and low surface tension, generally around 30-40 Dyn / cm. Therefore, to ensure good adhesion and drying speed on these non-absorbent plastic substrates, plastic inks are generally required to have good printability, strong adhesion to plastic films, fast drying speed, and bright colors and excellent gloss for printed images and text.

[0003] Currently, plastic printing is mostly done with solvent-based inks, primarily because they have a relatively low surface tension, typically around 28 dyn / cm, which provides good wettability and adhesion to plastic substrates and thin films. Plastic printing inks are primarily solvent-based, using highly volatile solvents like toluene as the dispersion medium, which accounts for over 60% of the ink composition. However, these highly volatile solvents contain aromatic hydrocarbons, which are toxic and flammable. Excessive levels of organic solvents like benzene can pose significant health risks, posing significant occupational health, safety, and environmental concerns.

[0004] With the in-depth implementation of national environmental protection policies, the water-based trend of plastic printing inks is inevitable. Water-based plastic inks are generally composed of water-based resins or emulsions as binders, pigments or dyes as colorants, water-based additives, and water as a dispersion medium. Since the surface tension of water is about 72 Dyn / cm, the surface tension of HYPERLINK water-based plastic inks is generally larger than 100 Dyn / cm. In order to ensure that HYPERLINK water-based inks have good adhesion, drying speed and comprehensive performance on plastic materials, it is necessary to select appropriate binder resins and additives, reduce the surface tension of HYPERLINK water-based plastic inks and improve the volatility of the water-solvent system. At the same time, the printing material also needs to be surface treated. Water-based plastic ink has the characteristics of low odor and being benzene-free, which reduces the emission of volatile organic compounds (VOCs) into the atmosphere and can effectively reduce the impact of residual solvents on the quality of packaged food. It is now being gradually promoted, but its adhesion performance with plastic substrates or films, its coordination performance with printing machines, and the overall performance and quality of printed products still need to be improved. Water-based resin emulsion as a binder plays a vital role in the coating performance and printing performance of plastic ink. Summary of the Invention

[0005] In response to the above-mentioned defects of existing water-based plastic inks, the present invention provides an acrylic modified polyurethane resin emulsion for water-based inks with good adhesion to plastic substrates. The emulsion is applied to gravure water-based plastic inks and has good adhesion to plastic films (such as PE, BOPP, PVC, and PET). The emulsion also has good printability. The water-based plastic ink can be used in the packaging, printing, and decorative fields of various plastic films, thereby solving the problems of adhesion and printability of water-based plastic inks to plastic substrates.

[0006] In order to solve the above technical problems, the technical solution provided by the present invention is: A polyurethane resin emulsion for water-based ink having good adhesion to plastic substrates. The raw materials thereof include, by mass, 80.0-160.0 parts of an acetone solution of an acrylate oligomer polyol, 60.0-120.0 parts of a polyester polyol, 10.0-30.0 parts of a polyether polyol, 50.0-70.0 parts of a diisocyanate, 10.0-20.0 parts of a carboxyl-type hydrophilic chain extender, 0.3-0.6 parts of an esterification reaction catalyst, 80.0-160.0 parts of acetone as a solvent, 5.0-10.0 parts of a low-molecular-weight polyol chain extender, 8.0-12.0 parts of a neutralizing salt-forming agent, triethylamine, 1.0-2.5 parts of a low-molecular-weight polyamine chain extender, ethylenediamine, and 400.0-500.0 parts of deionized water.

[0007] Furthermore, the raw materials of the acrylate oligomer polyol acetone solution include, by mass, 18.0-26.0 parts of tert-dodecyl mercaptan-S, 0.0-100.0 parts of ethyl acrylate, 30.0-100.0 parts of butyl acrylate, 0.0-120.0 parts of lauryl acrylate, 0.0-80.0 parts of octadecyl acrylate, 140.0-280.0 parts of isobornyl acrylate, 18.0-36.0 parts of hydroxyethyl acrylate, 12.0-18.0 parts of azobisisobutyronitrile, and 240.0-360.0 parts of solvent acetone.

[0008] The introduction of specialty acrylate monomers such as lauryl acrylate, octadecyl acrylate, and isobornyl acrylate significantly improves wettability and adhesion to plastic substrates. Acetone, the same solvent used in the acetone-based synthesis of polyurethane resin emulsions, is used as the solvent for the preparation of acrylate oligomer polyols. This avoids the issue of solvent differences and effectively improves the ease of synthesis.

[0009] The acrylate-modified polyurethane resin emulsion for water-based inks having excellent adhesion to plastic substrates comprises a polyester polyol comprising a mixture of one or more of butanediol adipic acid polyester diol, hexanediol adipic acid polyester diol, and dimer acid polyester diol. More preferably, the dimer acid polyester diol accounts for 40-80% of the total polyester polyol mass. The present invention innovatively utilizes a composite of polyester polyols and polyether polyols. It should be noted that the novel dimer acid polyester polyol is introduced. The structural characteristics of the dimer acid polyester polyol give it excellent adhesion to plastic substrates and impart good anti-stick properties to the coating film.

[0010] The acrylic ester modified polyurethane resin emulsion for water-based ink having good adhesion to plastic substrates, and the polyether polyol is one of polypropylene glycol ether diol and polytetramethylene glycol ether diol or a mixture of the two.

[0011] Furthermore, the number average molecular weight Mn of the polyester polyol and the polyether polyol is 1000-4000.

[0012] The acrylic acid ester modified polyurethane resin emulsion for water-based ink has good adhesion to plastic substrates, and the diisocyanate is a mixture of one or more of hexamethylene diisocyanate, isophorone diisocyanate, and dicyclohexylmethane diisocyanate.

[0013] The acrylic ester modified polyurethane resin emulsion for water-based ink has good adhesion to plastic substrates, and the carboxyl type hydrophilic chain extender is one of dimethylol propionic acid and dimethylol butyric acid or a mixture of the two.

[0014] The acrylic ester-modified polyurethane resin emulsion for water-based ink has good adhesion to plastic substrates, and the esterification reaction catalyst is one of bismuth isooctanoate and bismuth neodecanoate or a mixture of the two.

[0015] The acrylic acid ester modified polyurethane resin emulsion for water-based ink has good adhesion to plastic substrates, and the low-molecular polyol chain extender is one of 2-methyl-1,3-propylene glycol and 1,4-butanediol or a mixture of the two.

[0016] Furthermore, the method for preparing the acrylate oligomer polyol acetone solution comprises the following steps: Step A: Dissolve the formulated amount of tert-dodecylmercaptan-S in acetone and stir to mix thoroughly to prepare a chain transfer agent solution. Dissolve the formulated amount of monomer raw materials, including ethyl acrylate, butyl acrylate, lauryl acrylate, octadecyl acrylate, isobornyl acrylate, and hydroxyethyl acrylate, in acetone and stir to mix thoroughly to prepare a raw monomer mixed solution. Dissolve the formulated amount of initiator azobisisobutyronitrile in acetone and stir to mix thoroughly to prepare an initiator solution.

[0017] Step B: Add the formulated amount of chain transfer agent solution to a 1000ml reactor equipped with a heater, a stirrer, and a distillation column, stir and heat, replace the air with nitrogen, and maintain the temperature for 30 minutes until the temperature reaches 55.0-60.0°C.

[0018] Step C: Add 10 wt% of the formulated raw monomer mixture solution and maintain the temperature for 15 minutes. Add 80 wt% of the formulated initiator solution and maintain the temperature for 10 minutes. Begin dripping the remaining raw monomer mixture solution, maintaining a constant dripping rate so that the remaining raw monomer mixture solution is added within 2.5 hours.

[0019] Step D: After the dropwise addition is completed, the remaining amount of the initiator solution is added and the mixture is kept warm for 1.5 hours.

[0020] Step E: After the heat preservation reaction is completed, samples are taken to test the solid content and viscosity. Based on the test results, an appropriate amount of solvent acetone is added to adjust the solid content and viscosity. When the solid content is 55.0-65.0 wt%, the hydroxyl content is 0.35 wt%-0.65 wt%, and the viscosity is 30.0-300.0 mPa·s / 25°C, the temperature is lowered and the material is discharged to obtain a light yellow transparent acrylate oligomer polyol acetone solution.

[0021] Among them, the above synthesis process steps are all carried out in a nitrogen protection atmosphere.

[0022] The application also provides a preparation method of an acrylate modified polyurethane resin emulsion for water-based ink with good adhesion to plastic substrates, comprising the following steps: S1 esterification reaction: in a 1000ml reaction kettle provided with a heating device, a stirrer and a distillation column, formula amount of polyester polyol and polyether polyol are added, heated to 100.0-105.0℃, and dried by water removal for 1 hour under reduced pressure to-0.06~-0.08Mpa; cooled to 50.0-52.0℃, and formula amount of acrylate oligomer polyol, propionyl, esterification reaction catalyst and solvent acetone are added, heated to 58.0-62.0℃, and reacted for 2.5-3.5 hours.

[0023] S2 chain extension reaction: after the esterification reaction is completed, the temperature is cooled to 48.0-50.0℃, and carboxyl type hydrophilic chain extender, low molecular chain extender, neutralizer and solvent acetone are added, heated to 58.0-62.0℃, and reacted for 4.0-5.0 hours.

[0024] S3 emulsification and post chain extension reaction: after the chain extension reaction is completed, the temperature is cooled to 35.0-38.0℃, the stirrer is adjusted to 800-1000rpm, deionized water is added for emulsification reaction, and polyamine chain extender is added for chain extension reaction, and high-speed stirring is maintained for 10.0-15.0 minutes.

[0025] S4 solvent removal: after the emulsification reaction is completed, the temperature is heated to 68.0-72.0℃, the pressure is reduced to-0.06~-0.08Mpa, and the solvent is removed for 2.5-4.0 hours, and the recovered solvent is collected; the residual content of the solvent is tested, and when the residual content of the solvent meets the index requirements, the negative pressure is released, and the pressure is returned to normal by nitrogen.

[0026] S5 adjusting the solid content and viscosity of the emulsion: after the solvent removal reaction is completed, the solid content and viscosity are tested, and according to the test results, deionized water is added to adjust the solid content and viscosity; when the solid content is 33.0-37.0wt%, the pH value is 7.5-9.0, the rotational viscosity is 100.0-500mPa·s / 25℃, and the emulsion particle size is 50.0-300.0nm, the product is discharged and packaged to obtain a light yellow translucent or opaque acrylate modified polyurethane resin emulsion.

[0027] Compared with the prior art, the application has the following advantages and beneficial effects: The present invention discloses an acrylate-modified polyurethane resin emulsion for water-based inks with excellent adhesion to plastic substrates, prepared by selecting raw materials, optimizing the content of each raw material component, and performing a polymerization-emulsification-desolvation synthesis process. The acrylate-modified polyurethane resin emulsion prepared by the preparation method is mixed with pigment or dye paste, various auxiliary agents, and a dispersion medium such as water and industrial alcohol, and then stirred and ground to produce a water-based plastic gravure printing ink. The resulting water-based plastic ink is low in odor, non-flammable, non-explosive, and non-corrosive to printing plates. It exhibits excellent adhesion to plastic films (such as PE, BOPP, PVC, and PET), good redissolubility, and excellent anti-stick properties. It also exhibits excellent adhesion to plastic film substrates (such as PE, BOPP, PVC, and PET), with adhesion reaching zero grade in a transparent adhesive tape test. Furthermore, the water-based plastic ink exhibits excellent printability and is suitable for packaging, printing, and decorative applications on various plastic films (such as PE, BOPP, PVC, and PET). DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the technical solutions of the present invention, preferred embodiments of the present invention are described below in conjunction with specific examples, but this should not be construed as limiting this patent.

[0029] Unless otherwise specified, the experimental methods or test methods described in the following examples are conventional methods; the reagents and materials described are obtained from conventional commercial channels or prepared by conventional methods unless otherwise specified.

[0030] In order to more clearly demonstrate the technical solution and technical effects provided by the present invention, the acrylate-modified polyurethane resin emulsion for water-based ink with good adhesion to plastic substrates and the preparation method thereof provided by the present invention are described in detail with specific examples below.

[0031] Example of Acrylate Oligomer Polyol Acetone Solution Table 1 shows examples of acrylate oligomer polyol acetone solutions, and Examples A to D are examples of the present invention.

[0032] Table 1 Examples of acrylate oligomer polyol acetone solutions

[0033] Example A The formulation of Example A is shown in Table 1 Example A, and the operating steps are as follows: Step A: Dissolve the formulated amount of tert-dodecylmercaptan-S in acetone and stir to mix thoroughly to prepare a chain transfer agent solution. Dissolve the formulated amount of monomer raw materials, including ethyl acrylate, butyl acrylate, lauryl acrylate, octadecyl acrylate, isobornyl acrylate, and hydroxyethyl acrylate, in acetone and stir to mix thoroughly to prepare a raw monomer mixed solution. Dissolve the formulated amount of initiator azobisisobutyronitrile in acetone and stir to mix thoroughly to prepare an initiator solution.

[0034] Step B: Add the formulated amount of chain transfer agent solution to a 1000ml reactor equipped with a heater, a stirrer, and a distillation column, stir and heat, replace the air with nitrogen, and maintain the temperature for 30 minutes until the temperature reaches 55.0-60.0°C.

[0035] Step C: Add 10 wt% of the formulated raw monomer mixture solution and maintain the temperature for 15 minutes. Add 80 wt% of the formulated initiator solution and maintain the temperature for 10 minutes. Begin dripping the remaining raw monomer mixture solution, maintaining a constant dripping rate so that the remaining raw monomer mixture solution is added within 2.5 hours.

[0036] Step D: After the dropwise addition is completed, the remaining amount of the initiator solution is added and the temperature is maintained for 1.5 hours.

[0037] Step E: After the heat preservation reaction is completed, samples are taken to test the solid content and viscosity. Based on the test results, an appropriate amount of solvent acetone is added to adjust the solid content and viscosity. After the solid content and viscosity meet the index requirements, the temperature is lowered and the material is discharged to obtain a light yellow transparent acrylate oligomer polyol acetone solution.

[0038] Among them, the above synthesis process steps are all carried out in a nitrogen protection atmosphere.

[0039] Example B The formulation of Example B is shown in Table 1 Example B, and its operating steps are the same as those of Example A.

[0040] Example C The formulation of Example C is shown in Table 1 Example C, and its operating steps are the same as those of Example A.

[0041] Example D The formulation of Example D is shown in Table 1 Example D, and the operating steps are the same as those of Example A.

[0042] Examples of Acrylate Modified Polyurethane Resin Emulsions Table 2 is the formula composition and implementation experimental results of the comparative examples and examples of acrylate modified polyurethane resin emulsion, wherein Comparative Example 1 and Comparative Example 2 are comparative examples of acrylate modified polyurethane resin emulsion, serving as comparative examples of the present invention, and Examples 1 to 8 are examples of the present invention.

[0043] Table 2 Acrylate modified polyurethane resin emulsion

[0044] Table 2 Acrylate modified polyurethane resin emulsion

[0045] Note: CMA-44: Mn=2000, butanediol adipate polyester polyol, Huada Chemical Group Co., Ltd. CMA-2066: Mn=2000, hexanediol adipic acid type polyester polyol, Huada Chemical Group Co., Ltd. BY3022: Mn=2000, dimerized hexanediol-based polyester polyol, Beijing Baiyuan Chemical Co., Ltd. PTMEG2000: Mn=2000, polytetramethylene ether glycol, Hyosung Chemical (Jiaxing) Co., Ltd. PPG2000:Mn=2000, polypropylene glycol, Hai'an Petrochemical Plant, Jiangsu Province KL-5#: Bismuth metal content 20wt% ± 0.5wt%, bismuth neodecanoate polyurethane catalyst, Shanghai Zhengui New Material Technology Co., Ltd. KL-2#: Bismuth metal content 20wt% ± 0.5wt%, bismuth isooctoate polyurethane catalyst, Shanghai Zhengui New Material Technology Co., Ltd. Example 1 The formulation of Example 1 is shown in Table 2 Example 1, and the operating steps are as follows: S1 Esterification reaction: Add the formulated amount of polyester polyol and polyether polyol to a 1000ml reactor equipped with a heating device, a stirrer and a distillation column, heat to 100.0-105.0°C, keep warm, reduce the pressure to -0.06~-0.08Mpa, remove water and dry for 1 hour; cool to 50.0-52.0°C, add the formulated amount of acrylate oligomer polyol acetone solution, polyisocyanate, esterification reaction catalyst and solvent acetone, heat to 58.0-62.0°C, keep warm and react for 2.5-3.5 hours.

[0046] S2 chain extension reaction: After the esterification reaction is completed, the temperature is lowered to 48.0-50.0℃, and a carboxyl-type hydrophilic chain extender, a low molecular weight chain extender, a neutralizer and solvent acetone are added. The temperature is raised to 58.0-62.0℃ and the reaction is kept at this temperature for 4.0-5.0 hours.

[0047] S3 emulsification and post-chain extension reaction: After the chain extension reaction is completed, cool to 35.0-38.0℃, adjust the stirrer to 800-1000rpm, add deionized water for emulsification reaction, and add polyamine chain extender for chain extension reaction at the same time, maintain high-speed stirring for 10.0-15.0 minutes.

[0048] S4: After the emulsification reaction is completed, the temperature is raised to 68.0-72.0℃, the pressure is reduced to -0.06~-0.08Mpa, and the solvent is removed for 2.5-4.0 hours. The solvent is collected and recovered; a sample is taken to test the residual solvent content. When the residual solvent content reaches the index requirement, the negative pressure is released and nitrogen is passed to normal pressure.

[0049] S5: Adjust the solid content and viscosity of the emulsion: After the solvent removal reaction is completed, take a sample to test the solid content and viscosity. Depending on the test results, add an appropriate amount of deionized water to adjust the solid content and viscosity. When the solid content and viscosity meet the index requirements, discharge and package the material to obtain a light yellow translucent or opaque acrylate modified polyurethane resin emulsion.

[0050] Comparative Example 1 The formulation composition of Comparative Example 1 is shown in Table 2, and the operation steps are the same as those of Example 1.

[0051] Comparative Example 2 The formulation composition of Comparative Example 2 is shown in Table 2, and the operating steps are the same as those of Example 1.

[0052] Example 2 The formulation of Example 2 is shown in Table 2 Example 2, and the operating steps are the same as those of Example 1.

[0053] Example 3 The formulation of Example 3 is shown in Table 2 Example 3, and the operating steps are the same as those of Example 1.

[0054] Example 4 The formulation of Example 4 is shown in Table 2 Example 4, and the operating steps are the same as those of Example 1.

[0055] Example 5 The formulation of Example 5 is shown in Table 2 Example 5, and the operating steps are the same as those of Example 1.

[0056] Example 6 The formulation of Example 6 is shown in Table 2 Example 6, and the operating steps are the same as those of Example 1.

[0057] Example 7 The formulation of Example 7 is shown in Table 2 Example 7, and the operating steps are the same as those of Example 1.

[0058] Example 8 The formulation of Example 8 is shown in Table 2 Example 8, and the operating steps are the same as those of Example 1.

[0059] The performance of the acrylate-modified polyurethane resin emulsion synthesized in the present invention is demonstrated through the properties of a water-based plastic ink prepared from it. The water-based plastic ink comprises the acrylate-modified polyurethane resin emulsion prepared in the present invention, a pigment paste, alcohol, water, and additives, including a leveling agent, a dispersant, a defoamer, a stabilizer, and a slip agent. The ink is dispersed and filtered in a high-speed disperser or other equipment to produce a water-based plastic gravure ink. The properties of the resulting water-based gravure plastic ink and the coating film are shown in Table 3.

[0060] Table 3 Water-based plastic ink and coating properties

[0061] Table 3 Water-based plastic ink and coating properties

[0062] The above examples demonstrate that the acrylate-modified polyurethane resin emulsion synthesized in the present invention, compared to the conventional polyurethane resin emulsions of Comparative Examples 1 and 2, produces a water-based plastic gravure printing ink with excellent solubility and anti-stick properties. It also exhibits good adhesion to plastic film substrates (such as PE, BOPP, PVC, and PET), with adhesion reaching zero grade in a cellophane tape test. Furthermore, the water-based plastic ink exhibits excellent printability and is suitable for packaging, printing, and decorative applications on various plastic films (such as PE, BOPP, PVC, and PET).

[0063] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. Persons skilled in the art will appreciate that improvements and modifications may be made without departing from the spirit and scope of the present invention, and such improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A polyurethane resin emulsion for water-based ink having good adhesion to plastic substrates, characterized in that: The raw materials include, by mass, 80.0-160.0 parts of acrylate oligomer polyol acetone solution, 60.0-120.0 parts of polyester polyol, 10.0-30.0 parts of polyether polyol, 50.0-70.0 parts of diisocyanate, 10.0-20.0 parts of carboxyl type hydrophilic chain extender, 0.3-0.6 parts of esterification reaction catalyst, 80.0-160.0 parts of acetone solvent, 5.0-10.0 parts of low molecular weight polyol chain extender, 8.0-12.0 parts of neutralizing salt-forming agent triethylamine, 1.0-2.5 parts of low molecular weight polyamine chain extender ethylenediamine, and 400.0-500.0 parts of deionized water. The raw materials of the acrylate oligomer polyol acetone solution include, by mass, 18.0-26.0 parts of tert-dodecyl mercaptan-S, 0.0-100.0 parts of ethyl acrylate, 30.0-100.0 parts of butyl acrylate, 0.0-120.0 parts of lauryl acrylate, 0.0-80.0 parts of octadecyl acrylate, 140.0-280.0 parts of isobornyl acrylate, 18.0-36.0 parts of hydroxyethyl acrylate, 12.0-18.0 parts of azobisisobutyronitrile, and 240.0-360.0 parts of acetone solvent.

2. The acrylate-modified polyurethane resin emulsion for water-based ink according to claim 1, characterized in that: The acrylate oligomer polyol acetone solution has a solid content of 55.0-65.0 wt%, a hydroxyl content of 0.35 wt%-0.65 wt%, and a transfer viscosity of 30.0-300.0 mPa·s / 25°C.

3. The acrylate-modified polyurethane resin emulsion for water-based ink according to claim 1, characterized in that: The preparation of the acrylate oligomer polyol acetone solution comprises the following steps: Step A: dissolving the formulated amount of tert-dodecyl mercaptan-S in acetone, stirring and mixing uniformly to prepare a chain transfer agent solution; Dissolve the monomer raw materials of ethyl acrylate, butyl acrylate, lauryl acrylate, octadecyl acrylate, isobornyl acrylate and hydroxyethyl acrylate in the solvent acetone, stir and mix evenly to prepare a raw material monomer mixed solution; Dissolve the formulated amount of initiator azobisisobutyronitrile in solvent acetone, stir and mix evenly to prepare an initiator solution; Step B: Add the formulated amount of chain transfer agent solution to a 1000ml reactor equipped with a heating device, a stirrer, and a distillation column, stir and heat, replace the air with nitrogen and protect, and keep the temperature at 55.0-60.0°C for 30 minutes; Step C: Add 10 wt% of the raw monomer mixture solution and keep warm for 15 minutes. Add 80 wt% of the initiator solution and keep warm for 10 minutes. Begin adding the remaining raw monomer mixture solution dropwise, maintaining a constant addition rate so that all the remaining raw monomer mixture solution is added dropwise within 2.5 hours. Step D: After the addition is completed, add the remaining amount of initiator solution and keep warm for 1.5 hours; Step E: After the heat preservation reaction is completed, acetone solvent is added to adjust the solid content and viscosity. When the solid content is 55.0-65.0 wt%, the hydroxyl content is 0.35 wt%-0.65 wt%, and the viscosity is 30.0-300.0 mPa·s / 25°C, the temperature is lowered and the material is discharged to obtain a light yellow transparent acrylate oligomer polyol acetone solution; Among them, the above synthesis process steps are all carried out in a nitrogen protection atmosphere.

4. The acrylate-modified polyurethane resin emulsion for water-based ink according to claim 1, characterized in that: The polyester polyol is a mixture of one or more of butanediol adipic acid polyester diol, hexanediol adipic acid polyester diol and dimer acid polyester diol; the mass percentage of the dimer acid polyester diol accounts for 40-80% of the total polyester polyol.

5. The acrylate-modified polyurethane resin emulsion for water-based ink according to claim 1, characterized in that: The polyether polyol is one or a mixture of polypropylene glycol ether diol and polytetramethylene glycol ether diol; the number average molecular weight Mn of the polyester polyol and the polyether polyol is 1000-4000.

6. The acrylate-modified polyurethane resin emulsion for water-based ink according to claim 1, characterized in that: The diisocyanate is a mixture of one or more of hexamethylene diisocyanate, isophorone diisocyanate and dicyclohexylmethane diisocyanate.

7. The acrylate-modified polyurethane resin emulsion for water-based ink according to claim 1, characterized in that: The carboxyl type hydrophilic chain extender is one of dimethylol propionic acid and dimethylol butyric acid or a mixture of the two.

8. The acrylate-modified polyurethane resin emulsion for water-based ink according to claim 1, characterized in that: The esterification reaction catalyst is one of bismuth isooctanoate and bismuth neodecanoate, or a mixture of the two.

9. The acrylate-modified polyurethane resin emulsion for water-based ink according to claim 1, characterized in that: The low molecular weight polyol chain extender is one of 2-methyl-1,3-propylene glycol and 1,4-butanediol or a mixture of the two.

10. A method for preparing the acrylate-modified polyurethane resin emulsion for water-based ink according to claim 1, characterized in that: The following steps are involved: S1 esterification reaction: Mix polyester polyol and polyether polyol, raise the temperature to 100.0-105.0℃, keep warm, reduce the pressure to -0.06~-0.08Mpa, remove water and dry for 1 hour; cool to 50.0-52.0℃, add acrylate oligomer polyol acetone solution, polyisocyanate, esterification reaction catalyst and solvent acetone, raise the temperature to 58.0-62.0℃, keep warm and react for 2.5-3.5 hours; S2 chain extension reaction: After the esterification reaction is completed, the temperature is lowered to 48.0-50.0°C, and a carboxyl-type hydrophilic chain extender, a low molecular weight chain extender, a neutralizing agent and solvent acetone are added. The temperature is raised to 58.0-62.0°C and the reaction is kept at this temperature for 4.0-5.0 hours. S3 Emulsification and post-chain extension reaction: After the chain extension reaction is completed, cool to 35.0-38.0℃, adjust the stirrer to 800-1000rpm, add deionized water for emulsification reaction, and add polyamine chain extender for chain extension reaction at the same time, maintaining high-speed stirring for 10.0-15.0 minutes; S4: After the emulsification and post-chain extension reaction, the temperature is raised to 68.0-72.0°C, the pressure is reduced to -0.06-0.08 MPa, the solvent is removed, and nitrogen is passed to normal pressure. S5: Adjusting the solid content and viscosity of the emulsion: After the solvent is removed, deionized water is added to adjust the solid content and viscosity. When the solid content is 33.0-37.0 wt%, the pH value is 7.5-9.0, the rotational viscosity is 100.0-500 mPa·s / 25°C, and the emulsion particle size is 50.0-300.0 nm, a light yellow translucent or opaque acrylate-modified polyurethane resin emulsion is obtained.

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