High-precision uv screen printing ink with good fluidity and preparation method thereof

Abstract

The application provides a high-precision UV screen printing ink with good fluidity and a preparation method thereof, which comprises the following raw materials in parts by weight: composite oligomer 30-45 parts, active diluent 15-25 parts, composite photoinitiator 5-15 parts, modified polyethylene wax 8-16 parts, modified dispersant 2-3 parts, silane coupling agent 1-2 parts, leveling agent 0.5-1 part and defoaming agent 0.5-1 part. The ink has good fluidity, yellowing resistance, wear resistance, hydrophobicity and color reduction degree, improves the precision, and thus good screen printing effect is obtained, and the ink has good market prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ink, and particularly relates to a high-precision UV screen printing ink with good fluidity and a preparation method thereof. BACKGROUND

[0002] UV ink refers to an ink that is cured by polymerization of monomers into polymers under the irradiation of ultraviolet light with different wavelengths and energy.

[0003] With the development of ink technology, the use of UV ink in modern screen printing is becoming more and more widely, and the market prospect is broad. Compared with traditional solvent ink, UV ink does not contain volatile organic solvents, has high environmental protection, and its viscosity and printing film thickness will not be affected by the environment; at the same time, the curing time of UV ink is relatively short, which saves time cost, improves printing speed and production efficiency; in addition, the printed product using UV ink has better physical and chemical properties and higher gloss, which is suitable for printing of high-precision products. However, the UV ink used in screen printing also has the characteristics of high viscosity, poor fluidity, insufficient adhesion of the ink after curing, unclear lines when printing fine patterns and small characters, and poor wear resistance.

[0004] Chinese patent CN 106833108B relates to a transparent and non-yellowing UV gloss oil and its preparation method and use method, which comprises the following components: photoinitiator, active diluent, surfactant, ultramarine ink, titanium dioxide and oligomer. The application solves the problem of yellowing of UV gloss oil from a physical point of view through the action of ultramarine ink and titanium dioxide in the UV gloss oil, but it does not involve the research on the fluidity of the ink, and the dispersion performance of the pigment is general.

[0005] Chinese patent CN 113416448B relates to a UV ink and its preparation method. The UV ink comprises the following raw materials: epoxy acrylate, polyester acrylate, polydiallyl phthalate, photoinitiator, photosensitizer, active diluent, diatomite, defoaming agent, polyethylene wax, dispersant and colorant. The raw materials of the application can produce synergistic effect, improve the adhesion, flexibility, wear resistance and curing effect of the whole UV ink, but it does not involve the research on the yellowing resistance of the ink, which is not conducive to the use in outdoor places.

[0006] Therefore, there is an urgent need for a high-precision UV screen printing ink with good fluidity, which can improve the effect of screen printing by having better fluidity, yellowing resistance, wear resistance, hydrophobicity and color reproduction. SUMMARY

[0007] In view of the existing technical problems, the present application aims to provide a high-precision UV screen printing ink with good fluidity and a preparation method thereof.The UV ink has good fluidity, yellowing resistance, wear resistance, hydrophobicity and color reduction, improves the precision, and thus obtains good screen printing effect, and has good market prospect.

[0008] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0009] The present application provides a high-precision UV screen printing ink with good fluidity, which comprises the following raw materials in parts by weight: composite oligomer 30-45 parts, active diluent 15-25 parts, composite photoinitiator 5-15 parts, modified polyethylene wax 8-16 parts, modified dispersant 2-3 parts, silane coupling agent 1-2 parts, leveling agent 0.5-1 part and defoaming agent 0.5-1 part.

[0010] The reaction mechanism and action of the present application are as follows:

[0011] 1.The composite oligomer of the present application is composed of modified epoxy acrylic resin and polyurethane acrylic resin. The applicant preliminarily synthesizes epoxy acrylic resin from epoxy resin and acrylic acid, and then modifies the resin with pentafluoropentanol to obtain the final modified epoxy acrylic resin. On the one hand, the epoxy resin added with acrylic acid improves the adhesion, impact resistance and hydrophobicity of the ink; at the same time, fluorine atoms are introduced into the epoxy acrylic resin, and fluorine atoms have the characteristics of small radius, strong electronegativity and low polarizability. Under the action of temperature and light, fluorine atoms are easy to migrate from the inside to the outside, which can reduce the surface tension of the resin to a certain extent, so that the ink has a certain hydrophobicity, and can also avoid the situation that the surface tension of the ink is greater than that of the printing surface, so as to improve the color reduction of the UV ink, improve the precision, and obtain good screen printing effect.

[0012] On the other hand, the polyurethane acrylic resin and the active diluent can produce synergistic effect, which can adjust the viscosity of the ink, promote the uniform mixing of the UV ink, improve the fluidity of the UV ink, and improve the printing effect; at the same time, the applicant adjusts the ratio between the modified epoxy acrylic resin and the polyurethane acrylic resin to synergistically promote the curing rate of the ink under the action of ultraviolet rays, saves time cost, improves printing speed, and also enables the printed layer of the cured ink to have excellent hardness, wear resistance, adhesion and corrosion resistance.

[0013] 2. The modified dispersant of the present application is synthesized by using maleic anhydride and 4-vinyl aniline first, and then mixing the obtained compound with acrylic acid in a specific ratio by olefin addition reaction to obtain the modified dispersant, which has a high ideal dispersion effect. The pyrrole and benzene ring structure formed after the reaction brings a more optimal steric hindrance effect to the modified dispersant, which can produce a more ideal anchoring effect in cooperation with the carboxylic acid structure in the acrylic acid, and can also avoid the agglomeration between particles, so that the raw materials are more stable and uniformly distributed in the ink system, the flowability of the UV ink is improved, and the printing effect is improved. In addition, the addition of the modified dispersant can reduce the grinding times of the ink and improve the production efficiency.

[0014] 3. The composite photoinitiator of the present application is composed of polymeric [2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone (photoinitiator 150) and 1,1'-(methylene di-4,1-phenylene) bis[2-hydroxy-2-methyl-1-propanone] (photoinitiator 127). In the process of screen printing, the UV ink absorbs energy to produce free radicals under ultraviolet light irradiation. The free radicals collide with the composite oligomer and the active diluent under high-speed activity, so that the double bond is opened, and then crosslinking reaction occurs to solidify and form a dense network structure, thereby improving the abrasion resistance of the ink. The applicant further adjusts the mass ratio between the two to make the printed layer of the ink have better yellowing resistance and folding resistance.

[0015] 4. The present application uses polytetrafluoroethylene modified polyethylene wax to improve the gloss and hand feeling of the surface of the ink printed layer, and improve the printing precision; at the same time, compared with general polyethylene wax, the polytetrafluoroethylene modified polyethylene wax is crosslinked by intermolecular collision under the action of the composite photoinitiator, thereby improving the abrasion resistance and hydrophobicity of the ink printed layer.

[0016] 5. The leveling agent of the present application can synergistically reduce the surface tension, wet the difficult-to-wet substrate, prevent the occurrence of pinholes and shrinkage holes, and improve the leveling and lubricating effect of the ink.

[0017] In some embodiments, the composite oligomer is a modified epoxy acrylate resin and a polyurethane acrylate resin, and the mass ratio of the two is (2-5):1.

[0018] In some embodiments, the preparation method of the modified epoxy acrylate comprises the following steps:

[0019] S1. Acrylic acid, a catalyst and hydroquinone are added to a container and stirred to obtain a mixture;

[0020] S2. The epoxy resin is added to the reactor, heated to 65-85 ° C, an initiator is added, and the mixture obtained in step S1 is added dropwise, the temperature is raised to 85-115 ° C, the reaction is kept warm until the acid value is less than 6mg KOH / g when the reaction is terminated, and the temperature is cooled to obtain an epoxy acrylic resin;

[0021] S3. Take the epoxy acrylic resin and pentafluoropentanol obtained in step S2 and add them to the reactor, add the initiator dropwise, heat to 65-100°C, keep the reaction temperature for 12-20h, cool and dry to obtain the modified epoxy acrylic resin.

[0022] In some embodiments, the viscosity of the epoxy resin in step S2 is 2000-6000 mPa·s.

[0023] In some embodiments, the mass ratio of epoxy acrylic resin to pentafluoropentanol in step S3 is 1:(1.1-1.8).

[0024] In some embodiments, the reactive diluent is a multifunctional acrylate monomer.

[0025] Specifically, the multifunctional acrylate monomer is any one or more of hexanediol diacrylate, triethylene glycol dimethacrylate, dipropylene glycol diacrylate, butanediol diacrylate, phthalic acid diacrylate, pentaerythritol triacrylate, and tricarboxymethyl propane tetraacrylate.

[0026] In some embodiments, the preparation method of the modified dispersant comprises the following steps:

[0027] (1) adding maleic anhydride and N-methylpyrrolidone into a reaction kettle and stirring to obtain a mixed solution;

[0028] (2) adding 4-vinylaniline to a reaction kettle, heating to 160-200° C., stirring, and dropping the mixed solution obtained in step (1) into the reaction kettle. After the dropwise addition is completed, the reaction is continued for 1-2 hours to obtain a reaction solution;

[0029] (3) Add acrylic acid, ammonium persulfate, and deionized water to a reactor, heat to 75-85° C., add the reaction solution obtained in step (2) dropwise, stir and react at a constant temperature of 75-85° C. for 3-5 hours, cool to room temperature, adjust the pH value to neutral, wash, filter, dry, and grind to obtain a modified dispersant.

[0030] In some embodiments, the mass ratio of 4-vinylaniline to maleic anhydride in step (2) is 1:(2-4).

[0031] In some embodiments, the composite photoinitiator is polymeric [2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone and 1,1'-(methylenebis-4,1-phenylene)bis[2-hydroxy-2-methyl-1-propanone], and the molar ratio of the two is (2-4):1.

[0032] In some embodiments, the modified polyethylene wax is a polytetrafluoroethylene modified polyethylene wax; the leveling agent is polydimethylsiloxane with a viscosity of 100-500 mPa·s; and the defoaming agent is a silicone defoaming agent.

[0033] Another aspect of the present application provides a preparation method of a high-precision UV screen printing ink with good fluidity, comprising the following steps:

[0034] I. Mixing the composite oligomer, active diluent, composite photoinitiator, modified polyethylene wax, modified dispersant, silane coupling agent, leveling agent and defoaming agent to obtain a preliminary mixture;

[0035] II. Grinding the preliminary mixture obtained in step I. by a three-roll mill to obtain a UV screen printing ink.

[0036] Compared with the prior art, the present application has the following beneficial effects:

[0037] 1. The UV ink of the present application has good fluidity, yellowing resistance, wear resistance, hydrophobicity and color reduction, improves the precision, and thus obtains good screen printing effect, and has good market prospect.

[0038] 2. The composite oligomer of the present application is composed of modified epoxy acrylate resin and polyurethane acrylate resin. On the one hand, the addition of the acrylated epoxy resin improves the adhesion, impact resistance and hydrophobicity of the ink; at the same time, the introduction of pentafluoropentanol improves the hydrophobicity and color reduction of the UV ink, and good screen printing effect is obtained. On the other hand, the applicant adjusts the viscosity of the ink by controlling the ratio between the two, improves the fluidity of the UV ink, and synergistically promotes the curing rate of the ink under the action of ultraviolet light, so that the printed layer of the cured ink has excellent hardness, wear resistance, adhesion and corrosion resistance.

[0039] 3. The modified dispersant of the present application can improve the fluidity and printing suitability of the UV ink, so that the raw materials are more stably and uniformly distributed in the ink system; in addition, the addition of the modified dispersant can reduce the grinding frequency of the ink and improve the production efficiency.

[0040] 4. The present application controls the mass ratio of the composite photoinitiator to make the printed layer of the ink have good yellowing resistance and folding resistance.

[0041] 5. The modified polyethylene wax of the present application can improve the glossiness and hand feeling of the surface of the ink printed layer, and improve the precision of printing, and can also improve the wear resistance and hydrophobicity of the ink printed layer. DETAILED DESCRIPTION

[0042] The present application will be described in detail below with reference to specific embodiments. It should be noted that the following examples are illustrative of the present application and are not intended to limit the present application. Other combinations and various modifications within the scope of the present application can be made without departing from the spirit or scope thereof.

[0043] Each ink was prepared according to the ratio of each raw material and the preparation method as specified in the following examples and comparative examples.

[0044] In order to facilitate the implementation of the present application by those skilled in the art, the manufacturers of some raw materials of the examples and comparative examples are described as follows:

[0045] Epoxy resin: purchased from Shanghai Yantitan E-commerce Co., Ltd., viscosity 3000 mPa.s and Wanqing Chemical Technology Co., Ltd., viscosity 8000 mPa.s;

[0046] Polyurethane acrylic resin: purchased from Shanghai Zhenli Shi Network Technology Co., Ltd., model EBECRYL 270;

[0047] Epoxy acrylic resin: purchased from Langfang Aolei Environmental Protection Technology Co., Ltd., model FX-450;

[0048] Polymerization [2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone (photoinitiator 150) and 1,1'-(methylene di-4,1-phenylene) bis[2-hydroxy-2-methyl-1-propanone] (photoinitiator 127): purchased from Hubei Jianchu Biological Medicine Co., Ltd.;

[0049] Polytetrafluoroethylene modified polyethylene wax: purchased from Shanghai Zhenli Shi Network Technology Co., Ltd., model TF1788;

[0050] Silane coupling agent: purchased from Qufu Yishun Chemical Co., Ltd., model KH-550;

[0051] Polydimethylsiloxane: purchased from Shanghai Hongfan Biological Technology Co., Ltd., model PMX-200;

[0052] Silicone defoamer: purchased from Guangzhou Xingzhengyuan Chemical Co., Ltd., model BYK008;

[0053] BYK111 dispersant: purchased from Guangzhou Haoliangda International Trade Co., Ltd.;

[0054] Other raw materials are not specially mentioned and can be purchased from the market.

[0055] Preparation Example 1

[0056] The preparation method of the modified epoxy acrylate A comprises the following steps:

[0057] S1. 1.2 kg of acrylic acid, 55 g of N,N-dimethylaniline, and 2.2 g of hydroquinone were added to a container and stirred for 30 min to obtain a mixture;

[0058] S2. 1 kg of epoxy resin was added to a reaction kettle, heated to 75°C, 100 g of ammonium persulfate was added, and the mixture obtained in step S1 was added dropwise, and the temperature was raised to 100°C, and the reaction was terminated when the acid value was less than 6 mg KOH / g, and then cooled to room temperature to obtain an epoxy acrylate resin;

[0059] S3. The epoxy acrylate resin obtained in step S2 and 3.2 kg of pentafluoropentanol were added to a reaction kettle, 120 g of ammonium persulfate was added dropwise, heated to 80°C, and reacted for 16 h, and then cooled to room temperature, and dried at 105°C for 6 h to obtain a modified epoxy acrylate resin A;

[0060] wherein the viscosity of the epoxy resin is 3000 mPa.s.

[0061] Preparation Example 2

[0062] The preparation method of the modified epoxy acrylate B is the same as that of Preparation Example 1, except that the viscosity of the epoxy resin used is 8000 mPa.s.

[0063] Preparation Example 3

[0064] The preparation method of the modified dispersant A comprises the following steps:

[0065] (1) 8 g of maleic anhydride and 12 g of N-methylpyrrolidone were added to a reaction kettle and stirred for 45 min to obtain a mixed solution;

[0066] (2) 3 g of 4-vinylaniline was added to the reaction kettle and heated to 180°C, and the mixed solution obtained in step (1) was added dropwise, and after the dropwise addition was completed, the reaction was continued for 1.5 h to obtain a reaction solution;

[0067] (3) 33 g of acrylic acid, 10 g of ammonium persulfate, and 50 g of deionized water were added to the reaction kettle and heated to 80°C, and the reaction solution obtained in step (2) was added dropwise, and the reaction was stirred at 80°C for 4 h, and then cooled to room temperature, and the acid and base values were adjusted to neutral, and then washed with deionized water and suction filtered, and dried at 105°C for 6 h, and then ground to obtain a modified dispersant A.

[0068] Preparation Example 4

[0069] The preparation method of the modified dispersant B comprises the following steps:

[0070] (1) 3g of maleic anhydride and 5g of N-methylpyrrolidone were added into a reaction kettle, stirred for 45min to obtain a mixed solution;

[0071] (2) 3g of 4-vinylaniline was added into the reaction kettle, heated to 180℃, and the mixed solution obtained in step (1) was added dropwise into the reaction kettle, and after the dropwise addition was completed, the reaction was continued for 1.5h to obtain a reaction solution;

[0072] (3) 18g of acrylic acid, 5g of ammonium persulfate and 25g of deionized water were added into the reaction kettle, heated to 80℃, and the reaction solution obtained in step (2) was added dropwise, and the reaction was stirred at 80℃ for 4h, cooled to room temperature, and the pH value was adjusted to neutral, then washed with deionized water, filtered, dried at 105℃ for 6h, and ground to obtain the modified dispersant B.

[0073] Example 1

[0074] A high-precision UV screen printing ink with good fluidity, comprising the following raw materials in parts by weight: modified epoxy acrylic resin A 28 parts, polyurethane acrylic resin 8 parts, diethylene glycol diacrylate 20 parts, photoinitiator 150 7.5 parts, photoinitiator 127 2.5 parts, polytetrafluoroethylene modified polyethylene wax 12 parts, modified dispersant A 2.5 parts, silane coupling agent KH-550 1.5 parts, polydimethylsiloxane PMX-200 0.8 parts, and silicone defoamer BYK008 0.8 parts.

[0075] The preparation method of the UV screen printing ink of the present embodiment comprises the following steps:

[0076] I. The modified epoxy acrylic resin A, the polyurethane acrylic resin, the diethylene glycol diacrylate, the photoinitiator 150, the photoinitiator 127, the polytetrafluoroethylene modified polyethylene wax, the modified dispersant A, the silane coupling agent KH-550, the polydimethylsiloxane PMX-200 and the silicone defoamer BYK008 were mixed to obtain a preliminary mixture;

[0077] II. The preliminary mixture obtained in step I was ground to a fineness of not more than 5μm by a three-roll mill to obtain the UV screen printing ink.

[0078] Example 2

[0079] A high-precision UV screen printing ink with good fluidity comprises the following raw materials in parts by weight: modified epoxy acrylic resin A 20 parts, polyurethane acrylic resin 10 parts, dipropylene glycol diacrylate 15 parts, photoinitiator 150 3.4 parts, photoinitiator 127 1.6 parts, polytetrafluoroethylene modified polyethylene wax 8 parts, modified dispersant A 2 parts, silane coupling agent KH-550 1 part, polydimethylsiloxane PMX-200 0.5 parts and silicone defoaming agent BYK008 0.5 parts.

[0080] The preparation method of the UV screen printing ink of the present embodiment is the same as that of Example 1.

[0081] Example 3

[0082] A high-precision UV screen printing ink with good fluidity comprises the following raw materials in parts by weight: modified epoxy acrylic resin A 37.5 parts, polyurethane acrylic resin 7.5 parts, dipropylene glycol diacrylate 25 parts, photoinitiator 150 12 parts, photoinitiator 127 3 parts, polytetrafluoroethylene modified polyethylene wax 16 parts, modified dispersant A 3 parts, silane coupling agent KH-550 2 parts, polydimethylsiloxane PMX-200 1 part and silicone defoaming agent BYK008 1 part.

[0083] The preparation method of the UV screen printing ink of the present embodiment is the same as that of Example 1.

[0084] Example 4

[0085] A high-precision UV screen printing ink with good fluidity and a preparation method thereof are provided, and the specific implementation is the same as that of Example 1, except that the modified epoxy acrylic resin is replaced by an equal amount of commercially available epoxy acrylic resin FX-450.

[0086] Example 5

[0087] A high-precision UV screen printing ink with good fluidity and a preparation method thereof are provided, and the specific implementation is the same as that of Example 1, except that 18 parts of modified epoxy acrylic resin and 18 parts of polyurethane acrylic resin are added.

[0088] Example 6

[0089] A high-precision UV screen printing ink with good fluidity and a preparation method thereof are provided, and the specific implementation is the same as that of Example 1, except that the modified epoxy acrylic resin A is replaced by an equal amount of modified epoxy acrylic resin B.

[0090] Example 7

[0091] A high-precision UV screen printing ink with good fluidity and a preparation method thereof, the specific implementation manner is the same as that of example 1, except that an equal amount of modified dispersant B is used to replace modified dispersant A.

[0092] Example 8

[0093] A high-precision UV screen printing ink with good fluidity and a preparation method thereof, the specific implementation manner is the same as that of example 1, except that 5 parts of photoinitiator 150 and 5 parts of photoinitiator 127 are added.

[0094] Comparative Example 1

[0095] A high-precision UV screen printing ink with good fluidity and a preparation method thereof, the specific implementation manner is the same as that of example 1, except that 36 parts of modified epoxy acrylic resin A is used to replace 28 parts of modified epoxy acrylic resin A and 8 parts of polyurethane acrylic resin is added.

[0096] Comparative Example 2

[0097] A high-precision UV screen printing ink with good fluidity and a preparation method thereof, the specific implementation manner is the same as that of example 1, except that an equal amount of commercially available BYK111 dispersant is used to replace modified dispersant A.

[0098] Effect evaluation:

[0099] The UV inks prepared in examples 1-8 and comparative examples 1-2 above were tested and analyzed, and the specific results are shown in table 1.

[0100] Performance test:

[0101] (1) Fluidity: The fluidity of the grinding fluid was detected according to the national standard GB / T 13217.4-2020;

[0102] (2) Hydrophobicity: After soaking at room temperature for 2h under standard atmospheric pressure, the hydrophobicity was evaluated, which is:

[0103] Excellent: no loss of luster, no discoloration, and no blistering and peeling; Good: slight loss of luster, slight discoloration, and no blistering and peeling; Poor: slight loss of luster, slight discoloration, and slight blistering and peeling;

[0104] (3) Gloss and yellowing resistance: The UV-curable ink was screen printed on a substrate, and the ink printing layer formed after curing formed a printed product, and the data was detected using a color difference meter;

[0105] L value represents glossiness, the greater the L value, the higher the glossiness, the smaller the L value, the lower the glossiness; a value represents the range from red to green, a positive value indicates a red color, the greater the a value, the more red it is, a negative value indicates a green color, the smaller the a value, the more green it is; b value represents the range from yellow to blue, b value is positive, indicating a yellow color, the greater the b value, the more yellow it is, b value is negative, indicating a blue color, the smaller the b value, the more blue it is.

[0106] Table 1 Performance test

[0107]

[0108] From the results of Table 1, it can be seen that the fluidity, hydrophobicity, glossiness and yellowing resistance of Examples 1-3 are better.

[0109] In Example 4, the same amount of commercially available epoxy acrylate resin FX-450 is used to replace the modified epoxy acrylate resin, and pentafluoropentanol is not introduced, so that the hydrophobicity, yellowing resistance and glossiness of the UV ink are all poor. In Example 5, the mass ratio of the modified epoxy acrylate resin to the polyurethane acrylate resin is 1:1, and after changing the mass ratio of the composite oligomer, the fluidity of the UV ink is improved to a certain extent, but the hydrophobicity and glossiness are greatly reduced. In Example 6, the viscosity of the epoxy resin used in the preparation of the modified epoxy acrylate is 8000 mPa.s, and the high viscosity increases the viscosity of the synthesized modified epoxy acrylate, which makes it difficult for the resin to mix uniformly in the system, thereby reducing the fluidity of the UV ink. In Example 7, the mass ratio of 4-vinylaniline to maleic anhydride added in the preparation of the modified dispersant is 1:1, which reduces the yield of the modified dispersant formed finally, and the commercially available dispersant used in Comparative Example 2 both make the dispersion of the system poor, thereby reducing the fluidity of the UV ink. In Example 8, the mass ratio of the photoinitiator 150 to the photoinitiator 127 is 1:1, which not only affects the curing rate of the printed layer of the ink, but also reduces the yellowing resistance and glossiness of the UV ink. In Comparative Example 1, only the modified epoxy acrylate resin is used without adding the polyurethane acrylate resin, which increases the viscosity of the system, reduces the fluidity, and also reduces the glossiness of the printed layer of the ink.

[0110] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the above is disclosed as a preferred embodiment, it does not limit the present application, and any skilled person in the art can make some changes or modifications to the above disclosed technical content without departing from the scope of the technical solution of the present application, which is equivalent to an equivalent embodiment. Any simple modification, equivalent change and modification of the above embodiments made in accordance with the technical essence of the present application are still within the scope of the technical solution.

Claims

1. A high-precision UV screen printing ink with good fluidity, characterized in that: The invention comprises the following raw materials in parts by weight: 30-45 parts of composite oligomer, 15-25 parts of reactive diluent, 5-15 parts of composite photoinitiator, 8-16 parts of modified polyethylene wax, 2-3 parts of modified dispersant, 1-2 parts of silane coupling agent, 0.5-1 part of leveling agent and 0.5-1 part of defoaming agent; The composite oligomer is a modified epoxy acrylic resin and a polyurethane acrylic resin, and the mass ratio of the two is (2-5):1; the modified epoxy acrylic resin is an epoxy acrylic resin into which fluorine atoms are introduced; The preparation method of the modified dispersant comprises the following steps: (1) Add maleic anhydride and N-methylpyrrolidone into a reaction kettle and stir to obtain a mixed solution; (2) Add 4-vinylaniline to a reaction kettle, heat to 160-200°C, stir, and dropwise add the mixed solution obtained in step (1) to the reaction kettle. After the dropwise addition is completed, continue the reaction for 1-2 hours to obtain a reaction solution; (3) Add acrylic acid, ammonium persulfate and deionized water into a reactor, heat to 75-85°C, add the reaction solution obtained in step (2) dropwise, stir and react at a constant temperature of 75-85°C for 3-5 hours, cool to room temperature, adjust the pH value to neutral, wash, filter, dry and grind to obtain a modified dispersant.

2. The high-precision UV screen printing ink with good fluidity according to claim 1, characterized in that: The preparation method of the modified epoxy acrylate resin comprises the following steps: S1. Acrylic acid, a catalyst, and hydroquinone are added to a container and stirred to obtain a mixture; S2. The epoxy resin is added to the reactor, heated to 65-85 ° C, an initiator is added, and the mixture obtained in step S1 is added dropwise, the temperature is raised to 85-115 ° C, the reaction is kept warm until the acid value is less than 6mg KOH / g when the reaction is terminated, and the temperature is cooled to obtain an epoxy acrylic resin; S3. Take the epoxy acrylic resin and pentafluoropentanol obtained in step S2 and add them to the reactor, add the initiator dropwise, heat to 65-100°C, keep the reaction temperature for 12-20h, cool and dry to obtain the modified epoxy acrylic resin.

3. The high-precision UV screen printing ink with good fluidity according to claim 2, characterized in that: The viscosity of the epoxy resin in step S2 is 2000-6000 mPa.s.

4. The high-precision UV screen printing ink with good fluidity according to claim 2, characterized in that: In step S3, the mass ratio of epoxy acrylic resin to pentafluoropentanol is 1:(1.1-1.8).

5. The high-precision UV screen printing ink with good fluidity according to claim 1, characterized in that: The reactive diluent is a multifunctional acrylate monomer.

6. The high-precision UV screen printing ink with good fluidity according to claim 1, characterized in that: The molar ratio of 4-vinylaniline to maleic anhydride in step (2) is 1:(2-4).

7. The high-precision UV screen printing ink with good fluidity according to claim 1, characterized in that: The composite photoinitiator is polymerized [2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone and 1,1'-(methylenebis-4,1-phenylene)bis[2-hydroxy-2-methyl-1-propanone], and the mass ratio of the two is (2-4):

1.

8. A method for preparing the high-precision UV screen printing ink with good fluidity according to any one of claims 1 to 7, characterized in that: The following steps are included:

1. mixing the composite oligomer, reactive diluent, composite photoinitiator, modified polyethylene wax, modified dispersant, silane coupling agent, leveling agent and defoamer to obtain a primary mixture; 2. Grind the primary mixture obtained in step 1 through a three-roll mill to obtain UV screen printing ink.

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