Preparation method of high-performance organic pigment for water-based printing ink

Abstract

The invention discloses a preparation method of a high-performance organic pigment for water-based printing ink, which comprises the following steps: dispersing an organic pigment in deionized water, and adding an emulsifier to prepare an organic pigment dispersion liquid; adding a hydrophilic monomer and a cross-linking monomer into the organic pigment dispersion liquid, stirring, uniformly emulsifying, adding an initiator, and stirring to react; after the reaction is finished, cooling, centrifuging and washing to obtain a first layer of coated organic pigment; the preparation method comprises the following steps: mixing a hydrophobic monomer and a functional monomer, and adding an emulsifier and deionized water to prepare microemulsion; dispersing the first-layer coated organic pigment in deionized water, dropwise adding the microemulsion and an initiator, and stirring for reaction; and after the reaction is finished, cooling, centrifuging, washing and drying to obtain the high-performance organic pigment for the water-based printing ink. According to the method disclosed by the invention, the performance of the organic pigment is optimized through a double-layer coating structure, so that the organic pigment has the advantages of dispersity, light resistance, high tinting strength, water and oil resistance and acid and alkali resistance.

Description

Technical Field

[0001] The invention relates to the technical field of organic pigments, and in particular to a method for preparing a high-performance organic pigment for water-based printing ink. Background Art

[0002] With the increasingly stringent environmental regulations and the promotion of green environmental protection concepts, water-based printing inks have become a widely used green alternative in the modern printing industry due to their low volatile organic compound (VOC) emissions, non-toxicity, harmlessness, and biodegradability. The performance of water-based printing inks is greatly affected by pigments, and the pigment's tinting power, transparency, dispersibility, and stability are directly related to the quality and application effect of the ink.

[0003] As a key component in water-based inks, organic pigments are widely used due to their bright colors, strong light resistance and good environmental protection. Compared with inorganic pigments, organic pigments have higher color saturation and good light transmittance, and are particularly suitable for ink products that require high transparency and bright colors. However, despite the significant advantages of organic pigments in water-based printing inks, there are still some problems that need to be solved, especially in terms of dispersion stability and tinting strength.

[0004] Organic pigments are usually insoluble in water, but are dispersed in the ink medium in the form of fine particles. Due to the high surface energy of pigment particles, they are easy to aggregate or precipitate in the liquid, causing the pigment dispersion to be unstable after standing for a period of time, resulting in particle aggregation and sedimentation, which affects the pigment's tinting power and color fastness. To solve this problem, the commonly used treatment method is to evenly disperse the pigment particles through ultrasonic or ball milling, but these methods are usually difficult to maintain the stability of the pigment for a long time, and the pigment may still precipitate and agglomerate.

[0005] In order to ensure good dispersibility of pigments in aqueous media, current technologies often rely on the addition of surfactants. Surfactants can adjust the surface polarity of pigments by adsorbing or coating on the surface of pigment particles, thereby improving the stability of pigment particles dispersed in water. Although this method effectively improves the dispersibility of pigments, the presence of surfactants also brings new problems. Surfactants are often physically adsorbed on the surface of pigment particles. Once the surfactant is desorbed, the surface polarity of the pigment particles may change, causing the pigment particles to re-aggregate or settle. This not only affects the dispersibility of the pigment, but may also cause the pigment's tinting power to decrease. Summary of the invention

[0006] Based on the problems existing in the background technology, the present invention provides a method for preparing high-performance organic pigments for water-based printing inks. The method of the present invention optimizes the performance of organic pigments through a double-layer coating structure, so that the organic pigments have the advantages of dispersibility, light resistance, high tinting strength, water and oil resistance, and acid and alkali resistance.

[0007] The present invention is implemented by the following technical solutions:

[0008] A method for preparing a high-performance organic pigment for water-based printing ink comprises the following steps:

[0009] S1. dispersing the organic pigment in deionized water, adding an emulsifier to prepare an organic pigment dispersion;

[0010] S2. Add the hydrophilic monomer and the cross-linking monomer to the organic pigment dispersion, stir, emulsify evenly, continue to add the initiator, control the reaction temperature and time, and ensure complete polymerization of the monomer;

[0011] S3. After the reaction is completed, the mixture is cooled to room temperature, centrifuged, unreacted monomers are removed, and the pigment particles are repeatedly washed with deionized water to obtain a first layer of coated organic pigment;

[0012] S4. The hydrophobic monomer and the functional monomer are mixed, and an emulsifier and deionized water are added to prepare a microemulsion;

[0013] S5. The first layer of coated organic pigment is dispersed in deionized water, the reaction temperature is controlled, the microemulsion and the initiator are added dropwise, the reaction time is controlled, and the monomer is completely polymerized;

[0014] S6. After the reaction is completed, the mixture is cooled to room temperature, centrifuged to remove unreacted monomers, and the pigment particles are repeatedly washed with deionized water and vacuum dried to obtain a high-performance organic pigment for water-based printing ink.

[0015] Furthermore, the organic pigment is an azo pigment.

[0016] Furthermore, the emulsifier in steps S1 and S4 is sodium dodecyl sulfate; and the initiator in steps S2 and S5 is potassium persulfate.

[0017] Furthermore, in step S2, the hydrophilic monomers are acrylic acid and methacrylic acid; and the cross-linking monomer is ethylene glycol dimethacrylate.

[0018] Furthermore, the mass ratio of acrylic acid, methacrylic acid and ethylene glycol dimethacrylate is (8-12):(5-8):1.

[0019] Furthermore, the mass ratio of the total amount of organic pigment to the hydrophilic monomer is 100:(5-7).

[0020] Furthermore, in step S2, the reaction temperature is 60-70° C., and the reaction time is 3-5 h.

[0021] Furthermore, in step S4, the hydrophobic monomers are methyl methacrylate and butyl acrylate; the functional monomers are glycidyl acrylate and acrylamide; and the mass ratio of methyl methacrylate, butyl acrylate, glycidyl acrylate and acrylamide is (5-8):(1.5-3):(1-3):1.

[0022] Furthermore, the mass ratio of the organic pigment coated in the first layer to the total amount of the hydrophobic monomer is 100:(6-10).

[0023] Furthermore, in step S5, the reaction temperature is 70-80° C., and the reaction time is 3-5 h.

[0024] Beneficial effects of the present invention:

[0025] The double-layer coating structure used in the present invention optimizes the performance of azo pigments, so that organic pigments have the advantages of dispersibility, light resistance, high tinting strength, water and oil resistance, and acid and alkali resistance. The first layer of hydrophilic coating focuses on dispersibility optimization to ensure that the pigment does not agglomerate in the aqueous medium. The second layer of hydrophobic coating focuses on functional protection (light resistance, water and oil resistance, and acid and alkali resistance) to extend the service life of the pigment. The double-layer structure enables organic pigments to have excellent water dispersibility and hydrophobic protection at the same time, and this synergistic effect is difficult to achieve in a single-layer coating. The first layer of hydrophilic coating is firmly bonded to the surface of the pigment, and the second layer of hydrophobic coating is evenly attached through the active points provided by the hydrophilic layer, the interlayer bonding strength is high, and the coating layer is more stable. In addition, the introduction of polar monomer acrylamide in the second layer of hydrophobic coating further improves the interface compatibility of the two layers and avoids stratification or peeling. The double-layer coated pigment can not only meet the high dispersibility requirements of water-based inks, but also maintain good performance in complex environments, without sacrificing the inherent color vitality of organic pigments, and is suitable for a wider range of application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are used to provide further explanation of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0027] Figure 1 It is a schematic structural diagram of a cross-sectional assembly of a dispersing and stirring assembly disclosed in the present invention;

[0028] Figure 2 It is a three-dimensional structural schematic diagram of the dispersing and stirring assembly disclosed in the present invention;

[0029] Figure 3 It is a schematic structural diagram of a cross-section of the main shaft disclosed in the present invention;

[0030] Figure 4 It is a schematic diagram of the structure of the drive shaft disclosed in the present invention;

[0031] Figure 5 It is a schematic diagram of the structure of the dispersing and stirring blade disclosed in the present invention;

[0032] Figure 6 It is a schematic structural diagram of a horizontal section of the dispersing and stirring component disclosed in the present invention at the position of the dispersing and stirring blades. DETAILED DESCRIPTION

[0033] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments, but the protection scope of the present invention is not limited to the following embodiments.

[0034] Example 1

[0035] A method for preparing a high-performance organic pigment for water-based printing ink comprises the following steps:

[0036] S1. In parts by weight, 100 parts of Pigment Red 170 were dispersed in 400 parts of deionized water, and 2 parts of sodium lauryl sulfate were added to prepare an organic pigment dispersion;

[0037] S2. Add 3.75 parts of acrylic acid, 2.25 parts of methacrylic acid and 0.375 parts of ethylene glycol dimethacrylate to the organic pigment dispersion, stir, emulsify evenly, continue to add 0.15 parts of potassium persulfate, control the reaction temperature to 65 ° C, and react for 4 hours;

[0038] S3. After the reaction is completed, the mixture is cooled to room temperature, centrifuged, unreacted monomers are removed, and the pigment particles are repeatedly washed with deionized water to obtain a first layer of coated organic pigment;

[0039] S4. 6 parts of methyl methacrylate, 2 parts of butyl acrylate, 2 parts of glycidyl acrylate and 1 part of acrylamide were mixed, and 2 parts of sodium lauryl sulfate and 50 parts of deionized water were added to prepare a microemulsion;

[0040] S5. 100 parts of the first layer of coated organic pigment were dispersed in 400 parts of deionized water, the reaction temperature was controlled to 75°C, the microemulsion and 0.25 parts of potassium persulfate were added dropwise, and the reaction was continued for 4 hours;

[0041] S6. After the reaction is completed, the mixture is cooled to room temperature, centrifuged to remove unreacted monomers, and the pigment particles are repeatedly washed with deionized water and vacuum dried to obtain a high-performance organic pigment for water-based printing ink.

[0042] Example 2

[0043] A method for preparing a high-performance organic pigment for water-based printing ink comprises the following steps:

[0044] S1. In parts by weight, 100 parts of Pigment Red 170 were dispersed in 400 parts of deionized water, and 2 parts of sodium lauryl sulfate were added to prepare an organic pigment dispersion;

[0045] S2. Add 3 parts of acrylic acid, 3 parts of methacrylic acid and 0.3 parts of ethylene glycol dimethacrylate to the organic pigment dispersion, stir, emulsify evenly, continue to add 0.15 parts of potassium persulfate, control the reaction temperature to 65 ° C, and react for 4 hours;

[0046] S3. After the reaction is completed, the mixture is cooled to room temperature, centrifuged, unreacted monomers are removed, and the pigment particles are repeatedly washed with deionized water to obtain a first layer of coated organic pigment;

[0047] S4. 8 parts of methyl methacrylate, 2 parts of butyl acrylate, 3 parts of glycidyl acrylate and 1 part of acrylamide were mixed, and 2 parts of sodium lauryl sulfate and 50 parts of deionized water were added to prepare a microemulsion;

[0048] S5. 100 parts of the first layer of coated organic pigment were dispersed in 400 parts of deionized water, the reaction temperature was controlled to 75°C, the microemulsion and 0.25 parts of potassium persulfate were added dropwise, and the reaction was continued for 4 hours;

[0049] S6. After the reaction is completed, the mixture is cooled to room temperature, centrifuged to remove unreacted monomers, and the pigment particles are repeatedly washed with deionized water and vacuum dried to obtain a high-performance organic pigment for water-based printing ink.

[0050] Comparative Example 1

[0051] A method for preparing an organic pigment comprises the following steps:

[0052] S1. In parts by weight, 100 parts of Pigment Red 170 were dispersed in 400 parts of deionized water, and 2 parts of sodium lauryl sulfate were added to prepare an organic pigment dispersion;

[0053] S2. Add 3.75 parts of acrylic acid, 2.25 parts of methacrylic acid and 0.375 parts of ethylene glycol dimethacrylate to the organic pigment dispersion, stir, emulsify evenly, continue to add 0.15 parts of potassium persulfate, control the reaction temperature to 65 ° C, and react for 4 hours;

[0054] S3. After the reaction is completed, the mixture is cooled to room temperature, centrifuged to remove unreacted monomers, and the pigment particles are repeatedly washed with deionized water to obtain a hydrophilic polymer-coated organic pigment.

[0055] Comparative Example 2

[0056] A method for preparing an organic pigment comprises the following steps:

[0057] S1. In parts by weight, 100 parts of Pigment Red 170 were dispersed in 400 parts of deionized water, and 2 parts of sodium lauryl sulfate were added to prepare an organic pigment dispersion;

[0058] S2. 6 parts of methyl methacrylate, 2 parts of butyl acrylate, 2 parts of glycidyl acrylate and 1 part of acrylamide were mixed, and 2 parts of sodium lauryl sulfate and 50 parts of deionized water were added to prepare a microemulsion;

[0059] S3. Disperse 100 parts of organic pigment in 400 parts of deionized water, control the reaction temperature to 75°C, dropwise add the microemulsion and 0.25 parts of potassium persulfate, and react for 4 hours;

[0060] S4. After the reaction is completed, the mixture is cooled to room temperature and centrifuged to remove unreacted monomers. The pigment particles are repeatedly washed with deionized water and vacuum dried to obtain a hydrophobic polymer-coated organic pigment.

[0061] Comparative Example 3

[0062] A method for preparing an organic pigment comprises the following steps:

[0063] S1. In parts by weight, 100 parts of Pigment Red 170 were dispersed in 400 parts of deionized water, and 2 parts of sodium lauryl sulfate were added to prepare an organic pigment dispersion;

[0064] S2. 3.75 parts of acrylic acid, 2.25 parts of methacrylic acid, 6 parts of methyl methacrylate and 2 parts of butyl acrylate were mixed, and 2 parts of sodium lauryl sulfate and 50 parts of deionized water were added to prepare a microemulsion;

[0065] S3. 100 parts of the first layer of coated organic pigment were dispersed in 400 parts of deionized water, the reaction temperature was controlled to 75°C, the microemulsion and 0.25 parts of potassium persulfate were added dropwise, and the reaction was continued for 4 hours;

[0066] S4. After the reaction is completed, cool to room temperature, centrifuge to remove unreacted monomers, repeatedly wash the pigment particles with deionized water, and vacuum dry to obtain a single-layer polymer-encapsulated organic pigment.

[0067] Comparative Example 4

[0068] A method for preparing an organic pigment comprises the following steps:

[0069] S1. In parts by weight, 100 parts of Pigment Red 170 were dispersed in 400 parts of deionized water, and 2 parts of sodium lauryl sulfate were added to prepare an organic pigment dispersion;

[0070] S2. Add 3.75 parts of acrylic acid and 2.25 parts of methacrylic acid to the organic pigment dispersion, stir, emulsify evenly, continue to add 0.15 parts of potassium persulfate, control the reaction temperature to 65 ° C, and react for 4 hours;

[0071] S3. After the reaction is completed, the mixture is cooled to room temperature, centrifuged, unreacted monomers are removed, and the pigment particles are repeatedly washed with deionized water to obtain a first layer of coated organic pigment;

[0072] S4. 6 parts of methyl methacrylate, 2 parts of butyl acrylate, 2 parts of glycidyl acrylate and 1 part of acrylamide were mixed, and 2 parts of sodium lauryl sulfate and 50 parts of deionized water were added to prepare a microemulsion;

[0073] S5. 100 parts of the first layer of coated organic pigment were dispersed in 400 parts of deionized water, the reaction temperature was controlled to 75°C, the microemulsion and 0.25 parts of potassium persulfate were added dropwise, and the reaction was continued for 4 hours;

[0074] S6. After the reaction is completed, the mixture is cooled to room temperature, centrifuged to remove unreacted monomers, and the pigment particles are repeatedly washed with deionized water and vacuum dried to obtain a high-performance organic pigment for water-based printing ink.

[0075] Comparative Example 5

[0076] A method for preparing an organic pigment comprises the following steps:

[0077] S1. In parts by weight, 100 parts of Pigment Red 170 were dispersed in 400 parts of deionized water, and 2 parts of sodium lauryl sulfate were added to prepare an organic pigment dispersion;

[0078] S2. Add 3.75 parts of acrylic acid, 2.25 parts of methacrylic acid and 0.375 parts of ethylene glycol dimethacrylate to the organic pigment dispersion, stir, emulsify evenly, continue to add 0.15 parts of potassium persulfate, control the reaction temperature to 65 ° C, and react for 4 hours;

[0079] S3. After the reaction is completed, the mixture is cooled to room temperature, centrifuged, unreacted monomers are removed, and the pigment particles are repeatedly washed with deionized water to obtain a first layer of coated organic pigment;

[0080] S4. 6 parts of methyl methacrylate and 2 parts of butyl acrylate were mixed, 2 parts of sodium lauryl sulfate and 50 parts of deionized water were added to prepare a microemulsion;

[0081] S5. 100 parts of the first layer of coated organic pigment were dispersed in 400 parts of deionized water, the reaction temperature was controlled to 75°C, the microemulsion and 0.25 parts of potassium persulfate were added dropwise, and the reaction was continued for 4 hours;

[0082] S6. After the reaction is completed, cool to room temperature, centrifuge to remove unreacted monomers, repeatedly wash the pigment particles with deionized water, and vacuum dry to obtain a double-layer polymer-encapsulated organic pigment.

[0083] Test Example 1

[0084] The performance tests were performed on the pigments prepared in Examples 1-2 and Comparative Examples 1-5:

[0085] (1) Weigh 0.1 g of pigment and 1.0 g of titanium dioxide, draw 1 mL of varnish with a syringe, and grind on a flat grinder three times, 50 revolutions each time. Scrape the ground ink and measure the tinting strength with a colorimeter. The tinting strength of Pigment Red 170 without polymer encapsulation is 100%;

[0086] (2) Test the light fastness of the pigment according to GB / T 1710-2008;

[0087] (3) The water resistance, oil resistance, acid resistance and alkali resistance of the pigment were tested according to GB / T 5211.5-2008.

[0088] The test results are shown in Table 1.

[0089] Group Tinting strength / % Lightfastness Water resistance Oil resistance Acid resistance Alkali resistance Example 1 128.4 7～8 5 5 5 5 Example 2 126.5 7～8 5 5 5 5 Comparative Example 1 109.1 5～6 3～4 4 3～4 3～4 Comparative Example 2 101.1 6 4 4～5 4 4 Comparative Example 3 116.3 6～7 4～5 4～5 4～5 4～5 Comparative Example 4 119.7 7 4 4～5 4～5 4～5 Comparative Example 5 121.5 6～7 4～5 4～5 4～5 4～5

[0090] As can be seen from the results in Table 1, the organic pigment examples prepared in the embodiments of the present invention achieve a comprehensive improvement in tinting power, light resistance, water resistance, oil resistance, acid resistance and alkali resistance through a double-layer coating design, showing excellent comprehensive performance. In Comparative Example 1, a single-layer hydrophilic polymer coating is used, which has strong water absorption in an aqueous environment, resulting in poor water resistance and light resistance, and lacks hydrophobic protection, and has limited corrosion resistance in oily, acidic and alkaline environments. In Comparative Example 2, a single-layer hydrophobic polymer coating is used, and the dispersibility of the hydrophobic layer in water is not improved, and the tinting power is not significantly increased, and other performances are also general. In Comparative Example 3, a single-layer combination coating of hydrophilic and hydrophobic mixtures is used, and compared with Comparative Examples 1 and 2 of a single coating, the dispersibility is also significantly increased, and the light resistance, acid resistance and alkali resistance are all improved. In comparative example 4, ethylene glycol dimethacrylate is not added to the hydrophilic layer as a cross-linking monomer, and the compactness and stability of the coating layer on the surface of the organic pigment are slightly lacking. The double-layer coating structure design effectively improves the protection ability of the pigment and can block most of the acid and alkali erosion, but some structures are missing and the performance is slightly reduced. In comparative example 5, no functional monomer is added to the hydrophobic layer, and the interlayer bonding force with the hydrophilic layer is reduced, and the structural integrity of the surface coating of the organic pigment deteriorates, resulting in the performance of the prepared pigment being lower than that in the embodiment. The double-layer coating structure in the embodiment of the present invention provides a more comprehensive protection system through the synergistic effect of the polar protection of the hydrophilic layer and the non-polar protection of the hydrophobic layer. The hydrophilic layer and the hydrophobic layer respectively solve the stability problems under different environments, and at the same time, with the help of the cross-linking and active groups of the functional monomers, the compactness, bonding and durability of the coating layer are significantly improved. This double-layer coating design shows obvious advantages in key properties such as tinting strength, light resistance, water resistance, oil resistance, acid and alkali resistance, and meets the needs of azo pigments in complex application environments such as water-based printing inks.

[0091] Test Example 2

[0092] The pigments prepared in Examples 1-2 and Comparative Examples 1-5 were tested for stability:

[0093] (1) Storage stability: The pigments prepared in Examples 1-2 and Comparative Examples 1-5 were dispersed in deionized water in equal parts and stored at 60° C. for one week and at 45° C. for 30 days, respectively, to observe whether precipitation occurred;

[0094] (2) Thermal Cycling Stability: Equal portions of the pigments prepared in Examples 1-2 and Comparative Examples 1-5 were dispersed in deionized water, stored at 70°C for 4 hours and then at -20°C for 4 hours, then stored at 70°C for 4 hours and then at -20°C for 4 hours, and this cycle was repeated 4 times. The change in particle size of the pigment particles before and after storage was measured using a laser particle size analyzer.

[0095] The test results are shown in Table 2.

[0096] Table 2

[0097]

[0098] It can be seen from the data in Table 2 that the organic pigments prepared in Examples 1 and 2 have better storage stability, less increase in particle size after hot and cold shock tests, and better stability. In Comparative Example 1, the organic pigment with a single layer of hydrophilic polymer will absorb water and swell in a high temperature environment, causing the coating layer to become loose and the particle size to increase; in a low temperature environment, the hydrophilic polymer shrinks or loses elasticity, and the physical attraction of the pigment particles increases, resulting in partial agglomeration. In Comparative Example 2, the organic pigment with a single layer of oleophilic polymer lacks affinity in an aqueous environment and has poor dispersibility. Temperature changes lead to accumulation of interfacial stress in the coating layer, and the hydrophobic layer may crack and fall off, reducing the stability of the pigment particles. In Comparative Example 3, the storage stability and hot and cold cycle stability of the combined hydrophilic and hydrophobic single layer coating are significantly improved compared to Comparative Examples 1 and 2, but the overall mechanical strength of the single layer coating is weak, and hot and cold cycles will still cause partial peeling. In Comparative Example 4, no cross-linking monomer was added to the hydrophilic layer, resulting in insufficient mechanical strength and durability of the coating layer, which was prone to expansion or rupture in a high temperature environment, and shrinkage in a low temperature environment would aggravate the interfacial stress between the hydrophilic layer and the hydrophobic layer, resulting in cracking of the coating layer. In Comparative Example 5, there was no functional monomer, the binding force between the hydrophilic layer and the hydrophobic layer decreased, the coating structure was not stable enough, and the coating layer was also prone to cracking.

[0099] Embodiment 3,

[0100] Before S1, deionized water is injected into container 1;

[0101] In S1, dispersing the organic pigment in deionized water includes adding the organic pigment to the deionized water and dispersing the organic pigment using a dispersing and stirring component;

[0102] In S2, after adding a hydrophilic monomer and a cross-linking monomer to the organic pigment dispersion, a dispersing and stirring component is used to stir the dispersion;

[0103] The dispersing and stirring assembly is arranged above the container 1 , and comprises a main shaft 2 and a plurality of dispersing and stirring blades 3 spirally arranged on the outer circumference of the main shaft 2 , and the dispersing and stirring blades 3 are rotatably connected to the main shaft 1 .

[0104] The main shaft 2 is a hollow shaft with an open upper end. A drive shaft 4 is slidably arranged inside the main shaft 2. A transmission wheel 5 is fixedly arranged on the portion of the upper end of the drive shaft 4 extending out of the main shaft 2. The transmission wheel 5 abuts against a conical drive wheel 6 arranged on the power output shaft of the power element 7.

[0105] When the driving shaft 4 moves axially relative to the main shaft 2 , the rotation speed of the driving shaft 4 decreases, and the driving shaft 4 drives the dispersing and stirring blades 3 to rotate.

[0106] The working principle of the above technical solution is:

[0107] A fixed bracket 8 is arranged at the upper part of the container 1, on which a main shaft 2 is rotatably arranged, the axis of the main shaft 2 coincides with the vertical center line of the container 2, and a plurality of spirally distributed dispersing and stirring blades 3 are rotatably arranged on the outer circumference of the lower part of the main shaft 2 located inside the container 1. The main shaft 2 is a hollow shaft with an upper end opening, and a driving shaft 4 is slidably arranged inside the main shaft 2. The driving shaft 4 can be arranged as a spline shaft, and a keyway corresponding to the spline shaft is arranged on the inner wall of the main shaft 2. A transmission wheel 5 is fixedly arranged on the part of the driving shaft 4 extending out of the main shaft 2, and the outer surface of the transmission wheel 5 The circumferential surface abuts against the conical surface of the driving wheel 6, and the power is transmitted to the driving shaft 4 through friction. The axis of the driving shaft 4 and the rotation axis of the driving wheel 6 are in the same vertical plane. The angle between the rotation axis of the driving shaft 4 and the rotation axis of the power output shaft of the power element 7 is equal to the angle between the rotation axis of the power output shaft of the power element 7 and the conical surface of the driving wheel 6. When the driving shaft 4 moves axially, it drives the transmission wheel 5 to move. When the circumferential surface of the transmission wheel 5 contacts the driving wheel 6 at different positions along the axial direction, the rotation speed of the driving shaft 4 is different. Figure 1 As shown, when the speed of the power output shaft of the power element 7 remains unchanged, the speed of the drive shaft 4 gradually decreases during the upward movement of the transmission wheel 5.

[0108] A spline 11 is fixedly arranged in the middle of the outer circumferential surface of the driving shaft 4 along the axial direction, and a spline groove 10 adapted to the spline 11 is arranged on the upper part of the inner wall of the main shaft 2, and the spline 12 is slidably arranged in the spline groove.

[0109] A spirally arranged through hole 9 is provided at the lower part of the side wall of the main shaft 2, the dispersing and stirring blade 3 is fan-shaped, and one end of the dispersing and stirring blade 3 close to the center of the circle is fixedly connected to the rotating shaft 13, the rotating shaft 13 is rotatably set in the through hole 9, and a slide groove 14 is fixedly set at one end of the rotating shaft extending into the cavity of the main shaft, and a slide column 12 is fixedly set at a position corresponding to the slide groove 14 at the lower part of the outer circumference of the driving shaft 4, and the slide column 12 is slidably set in the slide groove 14.

[0110] A plurality of grooves 15 are provided on the arc surface of the dispersing and stirring blade 3 to achieve a better dispersing effect.

[0111] When dispersing granular materials in liquid, the plane of the dispersing stirring blade 3 is parallel to the rotation plane, and the rotation speed of the dispersing stirring blade 3 is relatively high, which can provide strong shear force and impact force and improve the dispersion efficiency of the material. Since the plane of the dispersing stirring blade 3 is parallel to the rotation plane, the axial agitation of the liquid is small, and the liquid cannot be fully mixed, which is not suitable for stirring. However, if the dispersion and stirring are completed with different equipment respectively, the cost and production time will be increased. When stirring, the angle of the dispersing stirring blade 3 can be rotated. The rotated dispersing stirring blade 3 forms a certain angle with the rotation plane, which can produce axial push on the liquid and improve the stirring efficiency. After rotating a certain angle, the impact on the dispersing stirring blade 3 will increase, and the strength requirement of the dispersing stirring blade 3 will also increase. Because the strong shear force and impact force in the dispersion process are not required during stirring, the rotation speed of the drive shaft during stirring is reduced, which can ensure that the dispersing stirring blade 3 will not be damaged and the mixing effect during the stirring process can be ensured.

[0112] like Figure 1-6 As shown, during the upward movement of the drive shaft 4, the rotation speed of the drive shaft 4 gradually decreases, and the slide column 12 on the drive shaft 4 drives the dispersion stirring blade 3 to rotate through the slide groove 14, so that when the dispersion stirring component is in the dispersion working state, the plane of the dispersion stirring blade 3 is parallel to the rotation plane, and the drive shaft 4 rotates at a high speed to meet the requirements of the dispersion working state. In the stirring state, the drive shaft 4 moves upward, the plane of the dispersion stirring blade 3 forms a certain angle with the rotation plane, and the drive shaft 4 rotates at a lower speed.

[0113] By adopting the above technical scheme, the dispersing and stirring component can be used to disperse the particulate material to form a dispersion liquid, and can also stir the dispersion liquid with added monomers to make the emulsification more uniform. The dispersing and stirring component has a simple structure, low cost, and improved production efficiency.

[0114] Finally, it should be noted that the above-mentioned embodiments only express several implementation methods of the present invention and are not intended to limit the invention. For those skilled in the art, any modification, equivalent replacement, improvement, etc. made without departing from the concept of the present invention should be included in the protection scope of the invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing a high-performance organic pigment for water-based printing ink, characterized in that: The following steps are involved: S1. dispersing the organic pigment in deionized water, adding an emulsifier to prepare an organic pigment dispersion; S2. Add the hydrophilic monomer and the cross-linking monomer to the organic pigment dispersion, stir, emulsify evenly, continue to add the initiator, control the reaction temperature and time, and ensure complete polymerization of the monomer; S3. After the reaction is completed, the mixture is cooled to room temperature, centrifuged, unreacted monomers are removed, and the pigment particles are repeatedly washed with deionized water to obtain a first layer of coated organic pigment; S4. The hydrophobic monomer and the functional monomer are mixed, and an emulsifier and deionized water are added to prepare a microemulsion; S5. The first layer of coated organic pigment is dispersed in deionized water, the reaction temperature is controlled, the microemulsion and the initiator are added dropwise, the reaction time is controlled, and the monomer is completely polymerized; S6. After the reaction is completed, the mixture is cooled to room temperature, centrifuged to remove unreacted monomers, and the pigment particles are repeatedly washed with deionized water and vacuum dried to obtain a high-performance organic pigment for water-based printing ink.

2. The method for preparing a high-performance organic pigment for water-based printing ink according to claim 1, characterized in that: The organic pigment is an azo pigment.

3. The method for preparing a high-performance organic pigment for water-based printing ink according to claim 1, characterized in that: The emulsifier in steps S1 and S4 is sodium dodecyl sulfate; the initiator in steps S2 and S5 is potassium persulfate.

4. The method for preparing a high-performance organic pigment for water-based printing ink according to claim 1, characterized in that: In step S2, the hydrophilic monomers are acrylic acid and methacrylic acid; and the cross-linking monomer is ethylene glycol dimethacrylate.

5. The method for preparing a high-performance organic pigment for water-based printing ink according to claim 4, characterized in that: The mass ratio of acrylic acid, methacrylic acid and ethylene glycol dimethacrylate is (8-12):(5-8):

1.

6. The method for preparing a high-performance organic pigment for water-based printing ink according to claim 1, characterized in that: The mass ratio of the total amount of organic pigment to the hydrophilic monomer is 100:(5-7).

7. The method for preparing a high-performance organic pigment for water-based printing ink according to claim 1, characterized in that: In step S2, the reaction temperature is 60-70° C. and the reaction time is 3-5 h.

8. The method for preparing a high-performance organic pigment for water-based printing ink according to claim 1, characterized in that: In step S4, the hydrophobic monomers are methyl methacrylate and butyl acrylate; the functional monomers are glycidyl acrylate and acrylamide; the mass ratio of methyl methacrylate, butyl acrylate, glycidyl acrylate and acrylamide is (5-8):(1.5-3):(1-3):

1.

9. The method for preparing a high-performance organic pigment for water-based printing ink according to claim 1, characterized in that: The mass ratio of the organic pigment coated in the first layer to the total amount of the hydrophobic monomer is 100:(6-10).

10. The method for preparing a high-performance organic pigment for water-based printing ink according to claim 1, characterized in that: In step S5, the reaction temperature is 70-80° C. and the reaction time is 3-5 h.

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