UV curing ink coating composition and preparation method thereof

Abstract

The invention relates to the field of ink preparation, in particular to a UV curing ink coating composition and a preparation method thereof. The composition is prepared from the following components: 40 to 66 parts of polyurethane acrylate, 8 to 30 parts of monoacrylate, 4 to 6 parts of 2-isopropyl thioxanthone, 1 to 7 parts of ethyl 4-methylaminobenzoate, 1 to 3 parts of oxidized polyethlene wax, 10 to 15 parts of carbon black, 1 to 2 parts of a stabilizer, 5 to 8 parts of a photoinitiator, 1 to 1.2 parts of a flatting agent, 0.4 to 0.8 part of a de-foaming agent and 1 to 3 parts of a dispersing agent. The stability of the ink is improved by classifying the components according to attributes, adopting a means of mixing and dispersing for multiple times, detecting intermediate products and finished products, including particle size agglomeration state, distribution state, viscosity, Zeta potential and surface tension value, and dynamically optimizing the preparation process.

Description

Technical Field

[0001] The present invention relates to the field of ink preparation, and particularly to a UV-curable ink coating composition and a preparation method thereof. Background Art

[0002] UV-curable inks are rapidly cured by ultraviolet irradiation and do not require solvent evaporation. They are widely used in fields such as printing, electronics, packaging, and 3D printing due to their high efficiency and environmental friendliness. Their core components usually include photocurable resins, reactive diluent monomers, photoinitiators, and pigments or functional fillers. However, in practical applications, the dispersion stability of inks is one of the key factors restricting their performance.

[0003] In traditional UV ink systems, insufficient dispersion of pigments or fillers easily leads to problems such as pigment sedimentation and agglomeration, nozzle clogging, and gloss and adhesion defects. In the prior art, the dispersion is usually improved by optimizing the grinding process. However, the compatibility between traditional dispersants and high-viscosity UV resin systems is poor, which may interfere with the photocuring reaction rate. Therefore, there is an urgent need to develop a UV ink composition with excellent dispersion stability, rapid curing characteristics, and wide pigment adaptability, which has become a technical difficulty that needs to be broken through in this field. Summary of the Invention

[0004] Therefore, the present invention provides a UV-curable ink coating composition and a preparation method thereof to overcome the problems of insufficient compatibility and storage stability of UV-curable inks due to poor dispersion in the prior art.

[0005] On the one hand, to achieve the above object, the present invention provides a UV-curable ink coating composition, comprising: polyurethane acrylate, monoacrylate, 2-isopropyl thioxanthone, ethyl 4-methylaminobenzoate, oxidized polyethylene wax, carbon black, stabilizer, photoinitiator, leveling agent, defoamer, and dispersant.

[0006] Furthermore, the weight fractions of each component are: 40-66 parts of polyurethane acrylate, 8-30 parts of monoacrylate, 4-6 parts of 2-isopropyl thioxanthone, 1-7 parts of ethyl 4-methylaminobenzoate, 1-3 parts of oxidized polyethylene wax, 10-15 parts of carbon black, 1-2 parts of stabilizer, 5-8 parts of photoinitiator, 1-1.2 parts of leveling agent, 0.4-0.8 parts of defoamer, and 1-3 parts of dispersant.

[0007] On the other hand, the present invention also provides a preparation method of a UV-curable ink coating composition, characterized by comprising:

[0008] Step S1, screening out Class A combination groups, Class B combination groups, and Class C combination groups from the composition;

[0009] Step S2: Use a disperser to mix the Class A combination group, heat it to the first preset temperature, and continue stirring for the first preset duration.

[0010] Step S3: Add a dispersant, heat it to the second preset temperature, and complete stirring for the second preset duration.

[0011] Step S4: Add the Class B combination group, stir and mix, add a dispersant, and complete stirring for the third preset duration to obtain the first base liquid.

[0012] Step S5: Obtain the particle size aggregation state and distribution state of the first base liquid to obtain the ink dispersion characteristic value.

[0013] Step S6: When it is preliminarily determined that the preparation of the first base liquid does not meet the preset standard according to the ink dispersion characteristic value, re-determine whether the preparation of the first base liquid meets the preset standard according to the viscosity of the first base liquid, or determine the reason why the preparation of the first base liquid does not meet the preset standard according to the Zeta potential of the first base liquid.

[0014] Step S7: When it is preliminarily determined that the preparation of the first base liquid meets the preset standard, add the Class C combination group to the first base liquid, heat it to the third preset temperature, stir and mix, and cool it to room temperature to obtain the finished composition.

[0015] Step S8: When the surface tension value of the finished composition is obtained and it is determined that the preparation of the finished composition does not meet the preset standard according to the surface tension, optimize the addition ratio of the Class C combination group.

[0016] The Class A combination group includes polyurethane acrylate, monoacrylate, 2-isopropyl thioxanthone, ethyl 4-methylaminobenzoate, and oxidized polyethylene wax; the Class B combination group includes carbon black, stabilizer, and photoinitiator; the Class C combination group includes leveling agent and defoamer.

[0017] Further, when the ink dispersion characteristic value is greater than or equal to the first preset dispersion threshold, it is preliminarily determined that the preparation of the first base liquid does not meet the preset standard.

[0018] When the ink dispersion characteristic value is greater than or equal to the first preset dispersion threshold and less than the second preset dispersion threshold, re-determine whether the preparation of the first base liquid meets the preset standard according to the viscosity of the first base liquid.

[0019] When the ink dispersion characteristic value is greater than or equal to the second preset dispersion threshold, determine the reason why the preparation of the first base liquid does not meet the preset standard according to the Zeta potential of the first base liquid.

[0020] Further, the particle size agglomeration state of the first base liquid is the variance value of the average particle size of the first base liquid, and the distribution state of the first base liquid is the Span value of the first base liquid.

[0021] Further, when the viscosity of the first base liquid is less than the preset viscosity, it is determined that the preparation of the first base liquid does not meet the preset standard, and the second preset temperature is increased to re-prepare the first base liquid, and the increase amplitude of the second preset temperature is positively correlated with the viscosity difference, where the viscosity difference is the difference between the preset viscosity and the viscosity of the first base liquid.

[0022] Further, the reasons for determining that the preparation of the first base liquid does not meet the preset standard according to the Zeta potential of the first base liquid include that the stirring rate does not meet the standard or the stirring duration does not meet the standard;

[0023] When the Zeta potential is less than the preset potential threshold, it is determined that the stirring rate does not meet the standard;

[0024] When the Zeta potential is greater than or equal to the preset potential threshold, it is determined that the stirring duration does not meet the standard.

[0025] Further, in response to the stirring rate not meeting the standard, the stirring rate for the preparation of the next batch of ink is reduced according to the difference between the preset potential threshold and the Zeta potential, and in response to the stirring duration not meeting the standard, each of the preset durations of stirring is increased according to the difference between the Zeta potential and the preset potential threshold.

[0026] Further, when the surface tension value of the finished composition is less than the preset tension threshold, it is determined that the preparation of the finished composition does not meet the preset standard.

[0027] Further, optimizing the addition ratio of the C-type combination group includes increasing the addition proportion of the leveling agent according to the difference between the preset tension threshold and the surface tension value of the finished composition.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows: The UV-curable ink coating composition of the present invention has a fast UV curing speed, is suitable for high-speed printing, has a low production cost, good resin wetting and dispersibility, and the photoinitiator and optimized formula used in the ink enable the ink to cure quickly under ultraviolet light, which can improve production efficiency. The optimized formula and component selection ensure the stability of the ink during production and use.

[0029] Further, by classifying the components according to their attributes, the present invention adopts means of multiple mixing and dispersion, and through the detection of intermediate products and finished products, including particle size agglomeration state, distribution state, viscosity, Zeta potential and surface tension value, and dynamically optimizes the preparation process, thereby improving the stability of the ink. Description of the Drawings

[0030] Figure 1 Flow chart of the preparation method of the UV-curable ink coating composition according to an embodiment of the present invention;

[0031] Figure 2 Flow chart for preliminarily determining whether the preparation of the first base liquid meets a preset standard according to the ink dispersion characteristic value in an embodiment of the present invention;

[0032] Figure 3 Flow chart for secondarily determining whether the preparation of the first base liquid meets a preset standard in an embodiment of the present invention;

[0033] Figure 4 Flow chart for determining whether the preparation of the finished composition meets a preset standard in an embodiment of the present invention. Detailed implementation manners

[0034] In order to make the objectives and advantages of the present invention clearer, the present invention will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and do not limit the protection scope of the present invention.

[0036] Please refer to Figure 1 、 Figure 2 、 Figure 3 and Figure 4 as shown, which are respectively the flow chart of the preparation method of the UV-curable ink coating composition according to the embodiment of the present invention; the flow chart for preliminarily determining whether the preparation of the first base liquid meets a preset standard according to the ink dispersion characteristic value in the embodiment of the present invention; the flow chart for secondarily determining whether the preparation of the first base liquid meets a preset standard in the embodiment of the present invention; the flow chart for determining whether the preparation of the finished composition meets a preset standard in the embodiment of the present invention.

[0037] On the one hand, an embodiment of the present invention provides a UV-curable ink coating composition, which includes the following components: polyurethane acrylate, monoacrylate, 2-isopropyl thioxanthone, ethyl 4-methylaminobenzoate, oxidized polyethylene wax, carbon black, stabilizer, photoinitiator, leveling agent, defoaming agent, and dispersant.

[0038] Specifically, the weight fractions of the respective components are: 40-66 parts of polyurethane acrylate, 8-30 parts of monoacrylate, 4-6 parts of 2-isopropyl thioxanthone, 1-7 parts of ethyl 4-methylaminobenzoate, 1-3 parts of oxidized polyethylene wax, 10-15 parts of carbon black, 1-2 parts of stabilizer, 5-8 parts of photoinitiator, 1-1.2 parts of leveling agent, 0.4-0.8 parts of defoaming agent, and 1-3 parts of dispersant.

[0039] Specifically, the stabilizer is hydroquinone or benzotriazole; the photoinitiator is 1-hydroxycyclohexyl phenyl ketone or phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide; the leveling agent is butyl cellulose; the defoaming agent is emulsified silicone oil or polydimethylsiloxane; the dispersant is isocyanuric acid triacrylate or sodium hexametaphosphate.

[0040] On the other hand, the present invention also provides a method for preparing a UV-curable ink coating composition, which is characterized by comprising:

[0041] Step S1, screening out Group A combination group, Group B combination group and Group C combination group from the composition;

[0042] Step S2, using a disperser (rotation speed 1100 rpm) to mix Group A combination group, then heating to a first preset temperature of 50 °C and continuing to stir for a first preset time of 15 min;

[0043] Step S3, adding a dispersant and then heating to a second preset temperature of 65 °C and completing stirring for a second preset time of 25 min;

[0044] Step S4, adding Group B combination group and stirring and mixing, then adding a dispersant and completing stirring for a third preset time of 20 min to obtain a first base liquid;

[0045] Step S5, obtaining the particle size aggregation state and distribution state of the first base liquid to obtain an ink dispersion characteristic value;

[0046] Step S6, when it is preliminarily determined that the preparation of the first base liquid does not meet the preset standard according to the ink dispersion characteristic value, re-determining whether the preparation of the first base liquid meets the preset standard according to the viscosity of the first base liquid, or determining the reason why the preparation of the first base liquid does not meet the preset standard according to the Zeta potential of the first base liquid;

[0047] Step S7, when it is preliminarily determined that the preparation of the first base liquid meets the preset standard, adding Group C combination group to the first base liquid, heating to a third preset temperature of 55 °C and stirring and mixing, and cooling to room temperature to obtain a finished product composition;

[0048] Step S8, obtaining the surface tension value of the finished product composition and optimizing the addition ratio of Group C combination group when it is determined that the preparation of the finished product composition does not meet the preset standard according to the surface tension;

[0049] The Group A combination group includes polyurethane acrylate, monoacrylate, 2-isopropylthioxanthone, ethyl 4-(methylamino)benzoate and oxidized polyethylene wax; the Group B combination group includes carbon black, a stabilizer and a photoinitiator; the Group C combination group includes a leveling agent and a defoaming agent.

[0050] Specifically, the particle size aggregation state of the first base liquid is the variance value of the average particle size of the first base liquid, and the distribution state of the first base liquid is the Span value of the first base liquid;

[0051] The ink dispersion characteristic value is obtained by the following formula:

[0052]

[0053] In the above formula, F is the ink dispersion characteristic value, α is the variance coefficient, with α set to 0.55, β is the Span coefficient, with β set to 0.45, V is the variance value of the average particle size of the first base liquid, V0 is the variance threshold, with V0 set to 0.22, S is the Span value of the first base liquid, and S0 is the Span threshold, with S0 set to 0.65.

[0054] Specifically, when the ink dispersion characteristic value is greater than or equal to the first preset dispersion threshold of 1.55, it is preliminarily determined that the preparation of the first base liquid does not meet the preset standard.

[0055] When the ink dispersion characteristic value is greater than or equal to the first preset dispersion threshold and less than the second preset dispersion threshold of 2.23, it is determined secondarily whether the preparation of the first base liquid meets the preset standard according to the viscosity of the first base liquid;

[0056] When the ink dispersion characteristic value is greater than or equal to the second preset dispersion threshold, the reason for the non - compliance of the preparation of the first base liquid with the preset standard is determined according to the Zeta potential of the first base liquid.

[0057] Specifically, when the viscosity of the first base liquid is less than the preset viscosity, it is determined secondarily that the preparation of the first base liquid does not meet the preset standard, and the second preset temperature is increased to re - prepare the first base liquid, and the increase amplitude of the second preset temperature is positively correlated with the viscosity difference. The viscosity difference is the difference between the preset viscosity and the viscosity of the first base liquid. It can be understood that the positive correlation can be a linear positive correlation or a non - linear positive correlation. The slope of the linear positive correlation is not specifically limited, as long as it satisfies that the greater the viscosity difference, the greater the increase amplitude of the second preset temperature.

[0058] Specifically, the reasons for the non - compliance of the preparation of the first base liquid with the preset standard determined according to the Zeta potential of the first base liquid include that the stirring rate does not meet the standard, or the stirring duration does not meet the standard;

[0059] When the Zeta potential is less than the preset potential threshold, it is determined that the stirring rate does not meet the standard;

[0060] When the Zeta potential is greater than or equal to the preset potential threshold of 30 mV, it is determined that the stirring duration does not meet the standard.

[0061] Specifically, in response to the stirring rate not meeting the standard, the stirring rate for the preparation of the next batch of ink is reduced according to the difference between the preset potential threshold and the Zeta potential. And, in response to the stirring duration not meeting the standard, each of the preset durations of stirring is increased according to the difference between the Zeta potential and the preset potential threshold. It can be understood that the greater the difference between the preset potential threshold and the Zeta potential, the greater the reduction amplitude of the stirring rate for the preparation of the next batch of ink. It can be reduced according to linear correlation or non-linear correlation, and the specific method is not limited. Each of the preset durations of increasing stirring can also be processed according to the above method. Among them, each of the preset durations includes a first preset duration, a second preset duration, and a third preset duration, and the increase of the first preset duration, the second preset duration, and the third preset duration can be increased in the same proportion.

[0062] Specifically, when the surface tension value of the finished composition is less than the preset tension threshold, it is determined that the preparation of the finished composition does not meet the preset standard, and the preset tension threshold is set to 40 mN / m.

[0063] Specifically, optimizing the addition ratio of the C-type combination group includes increasing the addition proportion of the leveling agent according to the difference between the preset tension threshold and the surface tension value of the finished composition. Among them, the adjustment amplitude of the addition proportion is not specifically limited, as long as it satisfies that the greater the difference between the preset tension threshold and the surface tension value of the finished composition, the greater the adjustment amplitude of the addition proportion.

[0064] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0065] The above are only the preferred embodiments of the present invention and are not used to limit the present invention; for those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A UV-curable ink coating composition, comprising the following components: polyurethane acrylate, monoacrylate, 2-isopropyl thioxanthone, ethyl 4-methylaminobenzoate, oxidized polyethylene wax, carbon black, stabilizer, photoinitiator, leveling agent, defoamer and dispersant.

2. The UV-curable ink coating composition according to claim 1, wherein The weight fractions of each of the above components are: 40-66 parts of polyurethane acrylate, 8-30 parts of monoacrylate, 4-6 parts of 2-isopropyl thioxanthone, 1-7 parts of ethyl 4-methylaminobenzoate, 1-3 parts of oxidized polyethylene wax, 10-15 parts of carbon black, 1-2 parts of stabilizer, 5-8 parts of photoinitiator, 1-1.2 parts of leveling agent, 0.4-0.8 parts of defoamer and 1-3 parts of dispersant.

3. A preparation method for the UV-curable ink coating composition according to claim 2, characterized in that, Including: Step S1, screening out Class A combination groups, Class B combination groups and Class C combination groups from the composition; Step S2, mixing the Class A combination groups using a disperser, heating to a first preset temperature, and continuing to stir for a first preset duration; Step S3, adding a dispersant, heating to a second preset temperature, and completing stirring for a second preset duration; Step S4, adding the Class B combination groups, stirring and mixing, adding a dispersant, and completing stirring for a third preset duration to obtain a first base liquid; Step S5, obtaining the particle size aggregation state and distribution state of the first base liquid to obtain an ink dispersion characteristic value; Step S6, when it is initially determined that the preparation of the first base liquid does not meet the preset standard according to the ink dispersion characteristic value, secondarily determining whether the preparation of the first base liquid meets the preset standard according to the viscosity of the first base liquid, or determining the reason why the preparation of the first base liquid does not meet the preset standard according to the Zeta potential of the first base liquid; Step S7, when it is initially determined that the preparation of the first base liquid meets the preset standard, adding the Class C combination groups to the first base liquid, heating to a third preset temperature, stirring and mixing, and cooling to room temperature to obtain a finished product composition; Step S8, obtaining the surface tension value of the finished product composition, and when it is determined that the preparation of the finished product composition does not meet the preset standard according to the surface tension, optimizing the addition ratio of the Class C combination groups; The Class A combination groups include polyurethane acrylate, monoacrylate, 2-isopropyl thioxanthone, ethyl 4-methylaminobenzoate and oxidized polyethylene wax; the Class B combination groups include carbon black, stabilizer and photoinitiator; the Class C combination groups include leveling agent and defoamer.

4. The preparation method of the UV-curable ink coating composition according to claim 3, characterized in that, When the ink dispersion characteristic value is greater than or equal to a first preset dispersion threshold, it is initially determined that the preparation of the first base liquid does not meet the preset standard. When the ink dispersion characteristic value is greater than or equal to the first preset dispersion threshold and less than the second preset dispersion threshold, secondarily determining whether the preparation of the first base liquid meets the preset standard according to the viscosity of the first base liquid; When the ink dispersion characteristic value is greater than or equal to the second preset dispersion threshold, determining the reason why the preparation of the first base liquid does not meet the preset standard according to the Zeta potential of the first base liquid.

5. The preparation method of the UV-curable ink coating composition according to claim 4, characterized in that, The particle size aggregation state of the first base liquid is the variance value of the average particle size of the first base liquid, and the distribution state of the first base liquid is the Span value of the first base liquid.

6. The preparation method of the UV-curable ink coating composition according to claim 5, characterized in that, When the viscosity of the first base liquid is less than the preset viscosity, it is determined that the preparation of the first base liquid does not meet the preset standard for the second time, and the second preset temperature is increased to re-prepare the first base liquid, and the increase amplitude of the second preset temperature is positively correlated with the viscosity difference, and the viscosity difference is the difference between the preset viscosity and the viscosity of the first base liquid.

7. The preparation method of the UV-curable ink coating composition according to claim 6, characterized in that, The reasons for determining that the preparation of the first base liquid does not meet the preset standard according to the Zeta potential of the first base liquid include that the stirring rate does not meet the standard or the stirring duration does not meet the standard. When the Zeta potential is less than the preset potential threshold, it is determined that the stirring rate does not meet the standard. When the Zeta potential is greater than or equal to the preset potential threshold, it is determined that the stirring duration does not meet the standard.

8. The preparation method of the UV-curable ink coating composition according to claim 7, characterized in that, In response to the stirring rate not meeting the standard, the stirring rate for the preparation of the next batch of ink is reduced according to the difference between the preset potential threshold and the Zeta potential, and in response to the stirring duration not meeting the standard, each of the preset durations of stirring is increased according to the difference between the Zeta potential and the preset potential threshold.

9. The preparation method of the UV-curable ink coating composition according to claim 1, characterized in that, When the surface tension value of the finished composition is less than the preset tension threshold, it is determined that the preparation of the finished composition does not meet the preset standard.

10. The preparation method of the UV-curable ink coating composition according to claim 1, characterized in that, Optimizing the addition ratio of the C-type combination group includes increasing the addition proportion of the leveling agent according to the difference between the preset tension threshold and the surface tension value of the finished composition.

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