Preparation method of water-based ink

Abstract

The invention relates to a preparation method of ink, in particular to a preparation method for improving the adhesive force of water-based ink by taking modified zeolite as an additive. The zeolite is subjected to phosphate functional group modification, so that the water-based resin material can be better connected, the connection performance of the ink and the resin material is greatly improved, and the adhesion performance and the water resistance of the ink on paper are further improved.

Description

Technical Field

[0001] The invention relates to a method for preparing ink, in particular to a method for preparing ink by using modified zeolite as an additive to improve the adhesion of water-based ink. Background Art

[0002] As an environmentally friendly printing material, water-based ink has been widely used in packaging, publishing, advertising and other fields. Compared with traditional solvent-based inks, water-based inks have significant advantages such as non-toxic, harmless, non-flammable and non-explosive, which meets the current society's pursuit of green environmental protection. However, there are also some problems in the application of water-based inks, the most prominent of which is its relatively low adhesion. Adhesion is the performance of the bonding force between the ink and the surface of the substrate, which directly affects the wear resistance, water resistance and overall quality of the printed product. Therefore, improving the adhesion of water-based inks has become a technical problem that needs to be solved in the field of water-based ink research and development.

[0003] Zeolite, as an inorganic material with unique pore structure and surface activity, has gradually attracted attention in the research and development of water-based inks in recent years. Zeolite has excellent adsorption performance and ion exchange capacity, and can effectively adsorb pigments and resin components in inks, making them more evenly dispersed in water, thereby improving the stability of inks and printing effects. At the same time, zeolite can also interact with the surface of the substrate through its surface active sites, enhance the bonding force between the ink and the substrate, and thus improve the adhesion of water-based inks. However, in the prior art, the effect of applying zeolite to water-based inks to improve the adhesion of inks is limited, and the addition of too much zeolite will affect the fluidity of water-based inks. Therefore, how to optimize the existing preparation method to break through the bottleneck is an urgent problem to be solved. Summary of the invention

[0004] In view of the above problems, the present invention can better connect water-based resin materials by modifying zeolite with phosphate functional groups, greatly improving the connection performance between ink and resin materials, and further improving the adhesion performance and water resistance of ink on paper.

[0005] The present invention provides a method for preparing a water-based ink, which comprises the following steps: (a) The selected zeolite was added into phosphoric acid solution and subjected to ultrasonic treatment and hydrothermal reaction; (b) performing a modification treatment on the phosphorylated zeolite to form a phosphate functional group to obtain a modified zeolite; (c) Modified zeolite, water-based resin, pigment, wetting agent, defoaming agent and appropriate amount of water are mixed to prepare water-based ink, wherein the amount of water-based resin is 30%-50% of the total amount of ink, the amount of pigment is 5%-30% of the total amount of ink, the amount of wetting agent is 0.5%-2% of the total amount of ink, the amount of defoaming agent is 0.1%-0.5% of the total amount of ink, the amount of modified zeolite added is 1%-5% of the total amount of ink, and the balance is water.

[0006] Preferably, in step (a), the selected zeolite is octahedral zeolite or can be replaced by other types of zeolites, such as A-type zeolite, X-type zeolite or Y-type zeolite.

[0007] Preferably, the concentration of the phosphoric acid solution is 80%-90%, the ultrasonic treatment time is 1-2 hours, and the temperature of the hydrothermal reaction is 100-150° C., and the time is 2-6 hours.

[0008] Preferably, in step (b), the modification treatment is to mix the phosphorylated zeolite with a modifier, heat to 80-100° C., stir and centrifuge, and dry the obtained separated material to obtain the modified zeolite.

[0009] Preferably, the modifier is selected from at least one of sodium dodecyl sulfate, hexadecyltrimethylammonium bromide or octadecyldimethylbenzylammonium chloride, and its usage is 1%-3% of the mass of zeolite.

[0010] Preferably, the stirring time is 30-60 minutes, the centrifugal separation speed is 3000-5000 rpm, the time is 5-15 minutes, and the drying temperature is 50-70° C., and the time is 10-14 hours.

[0011] Preferably, in step (c), the water-based resin material is a polyurethane resin or an acrylic resin.

[0012] Preferably, in step (c), the pigment is titanium dioxide or carbon black.

[0013] Preferably, in step (c), the wetting agent is a nonionic or anionic wetting agent.

[0014] Compared with the prior art, the present invention has the following advantages: The present invention effectively overcomes the bottleneck problem of using zeolite to improve the adhesion of water-based ink in the prior art by optimizing the selection and modification of zeolite. The zeolite selected by the present invention is first hydrothermally phosphorylated and modified so that the inner wall of the zeolite pores carries phosphate groups, and then the phosphoric acid functional groups modified on the surface of the zeolite are introduced into the interior of the zeolite pores through a modifier to form a phosphate-modified zeolite. The effective phosphorylated functional groups on the surface of the zeolite are increased, which significantly enhances its adsorption capacity with pigments and resins in the ink, as well as the interaction strength with the surface of the substrate. This makes the prepared water-based ink have higher adhesion and stability, greatly improves the wear resistance, water resistance and overall quality of the printed product, and meets the market's urgent demand for high-quality water-based inks.

[0015] The present invention not only solves the compatibility problem when zeolite is used in water-based ink, but also optimizes the ink performance by accurately controlling the amount of zeolite added. Compared with the prior art, the water-based ink prepared by the present invention has better printing adaptability and a wider range of applications while maintaining the advantages of environmental protection, non-toxicity, and harmlessness. This not only reduces printing costs and improves printing efficiency, but also provides the possibility for the application of water-based ink in more fields, and promotes the further development and innovation of water-based ink technology. DETAILED DESCRIPTION

[0016] Embodiment 1, the present invention provides a method for preparing a water-based ink, which comprises the following steps: (a) The selected octahedral zeolite (average particle size 42 nm) was added to a phosphoric acid solution with a concentration of 85% and subjected to ultrasonic treatment for 1.5 hours. The mixture was then transferred to a reactor and subjected to a hydrothermal reaction at 120 °C for 4 hours. (b) modifying the phosphorylated zeolite by taking out the zeolite after the hydrothermal reaction, mixing it with 2% (based on the mass of the zeolite) of sodium dodecyl sulfate, stirring and reacting it at 90° C. for 45 minutes, and then centrifuging it at a speed of 4000 rpm for 10 minutes, and drying the obtained fraction at 60° C. for 12 hours to form a phosphate functional group to obtain a modified zeolite; (c) Mixing modified zeolite, water-based resin polyurethane resin accounting for 40% of the total amount of ink, titanium dioxide accounting for 20% of the total amount of ink, wetting agent (non-ionic type) accounting for 1% of the total amount of ink, defoaming agent accounting for 0.3% of the total amount of ink and an appropriate amount of water, stirring evenly, filtering to remove impurities, and preparing a water-based ink.

[0017] Embodiment 2, the present invention provides a method for preparing a water-based ink, which comprises the following steps: (a) The selected A-type zeolite (average particle size 45 nm) was added to a phosphoric acid solution with a concentration of 80% and subjected to ultrasonic treatment for 2 hours. The mixture was then transferred to a reactor and subjected to a hydrothermal reaction at 100 °C for 6 hours. (b) modifying the phosphorylated zeolite, specifically, taking out the zeolite after the hydrothermal reaction, mixing it with 1% (based on the mass of the zeolite) of hexadecyltrimethylammonium bromide, stirring and reacting it at 80° C. for 60 minutes, and then centrifuging it at a speed of 3000 rpm for 15 minutes, and drying the obtained fraction at 50° C. for 14 hours to form a phosphate functional group, thereby obtaining a modified zeolite; (c) Mixing modified zeolite, water-based resin material (acrylic resin) accounting for 30% of the total amount of ink, pigment (carbon black) accounting for 5% of the total amount of ink, wetting agent (anionic type) accounting for 0.5% of the total amount of ink, defoaming agent accounting for 0.1% of the total amount of ink and an appropriate amount of water, stirring evenly, filtering to remove impurities, and preparing a water-based ink.

[0018] Embodiment 3, the present invention provides a method for preparing a water-based ink, which comprises the following steps: (a) The selected X-type zeolite (average particle size 49 nm) was added to a 90% phosphoric acid solution and subjected to ultrasonic treatment for 1 hour. The mixture was then transferred to a reactor and subjected to a hydrothermal reaction at 150 °C for 2 hours. (b) modifying the phosphorylated zeolite by taking out the zeolite after the hydrothermal reaction, mixing it with 3% (based on the mass of the zeolite) of octadecyl dimethyl benzyl ammonium chloride, stirring and reacting it at 100° C. for 30 minutes, and then centrifuging it at a speed of 5000 rpm for 5 minutes, and drying the obtained fraction at 70° C. for 10 hours to form a phosphate functional group to obtain a modified zeolite; (c) Mixing the modified zeolite, the water-based resin material (polyurethane resin) accounting for 50% of the total amount of the ink, the pigment (titanium dioxide) accounting for 30% of the total amount of the ink, the wetting agent (non-ionic type) accounting for 2% of the total amount of the ink, the defoaming agent accounting for 0.5% of the total amount of the ink and an appropriate amount of water, stirring evenly, filtering to remove impurities, and preparing a water-based ink.

[0019] Comparative Example 1 is different from Example 1 in that it uses unmodified octahedral zeolite.

[0020] Comparative Example 2 is different from Example 1 in that sulfuric acid is used instead of phosphoric acid.

[0021] Comparative Example 3 is different from Example 1 in that it does not undergo the hydrothermal reaction in step (a).

[0022] Comparative Example 4 is different from Example 1 in that it is not processed in step (b).

[0023] In order to comprehensively evaluate the performance of the water-based ink prepared by the present invention, we conducted multiple characterization tests on the water-based inks of Examples 1-3 and Comparative Examples 1-4, including adhesion test, water resistance test, fluidity test and abrasion resistance test. The following are specific characterization condition parameters and characterization data: 1. Adhesion test: Test method: The ink adhesion on paper was tested by the cross-cut method according to ASTM D3359.

[0024] 2. Water resistance test: Test method: After immersing the paper printed with ink in water for 24 hours, observe the changes on the printed surface.

[0025] 3. Liquidity test: Test Method: Use a rotational viscometer to measure the viscosity of the ink to evaluate its fluidity.

[0026] 4. Wear resistance test: Test method: Use an abrasion tester to test the paper printed with ink, and record the number of abrasions until the printed surface is obviously worn.

[0027]

[0028] These data show that the water-based inks of Examples 1-3 all perform well in adhesion, water resistance, fluidity and abrasion resistance, while the water-based inks of Comparative Examples 1-4 perform poorly in each test. These data further verify that the present invention successfully prepares water-based inks with excellent performance by optimizing the selection and modification of zeolite.

Claims

1. A method for preparing a water-based ink, characterized in that: The following steps are involved: (a) The selected zeolite was added into phosphoric acid solution and subjected to ultrasonic treatment and hydrothermal reaction; (b) performing a modification treatment on the phosphorylated zeolite to form a phosphate functional group to obtain a modified zeolite; (c) Modified zeolite, water-based resin, pigment, wetting agent, defoaming agent and appropriate amount of water are mixed to prepare water-based ink, wherein the amount of water-based resin is 30%-50% of the total amount of ink, the amount of pigment is 5%-30% of the total amount of ink, the amount of wetting agent is 0.5%-2% of the total amount of ink, the amount of defoaming agent is 0.1%-0.5% of the total amount of ink, the amount of modified zeolite added is 1%-5% of the total amount of ink, and the balance is water.

2. The method for preparing water-based ink according to claim 1, characterized in that: In step (a), the selected zeolite is octahedral zeolite or can be replaced by other types of zeolites, such as A-type zeolite, X-type zeolite or Y-type zeolite.

3. The method for preparing water-based ink according to claim 1, characterized in that: The concentration of the phosphoric acid solution is 80%-90%, the ultrasonic treatment time is 1-2 hours, the temperature of the hydrothermal reaction is 100-150° C., and the time is 2-6 hours.

4. The method for preparing water-based ink according to claim 1, characterized in that: In step (b), the modification treatment is to mix the phosphorylated zeolite with a modifier, heat to 80-100° C., stir and centrifuge, and dry the obtained separated material to obtain the modified zeolite.

5. The method for preparing water-based ink according to claim 1, characterized in that: The modifier is selected from at least one of sodium dodecyl sulfate, hexadecyltrimethylammonium bromide or octadecyldimethylbenzylammonium chloride, and its usage is 1%-3% of the mass of zeolite.

6. The method for preparing the water-based ink according to claim 4, characterized in that: The stirring time is 30-60 minutes, the centrifugal separation speed is 3000-5000 rpm, the time is 5-15 minutes, and the drying temperature is 50-70° C., and the time is 10-14 hours.

7. The method for preparing water-based ink according to claim 1, characterized in that: In step (c), the water-based resin material is polyurethane resin or acrylic resin.

8. The method for preparing water-based ink according to claim 1, characterized in that: In step (c), the pigment is titanium dioxide or carbon black.

9. The method for preparing water-based ink according to claim 1, characterized in that: In step (c), the wetting agent is a nonionic or anionic wetting agent.

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